Androgen responsiveness of Renilla luciferase reporter vectors is promoter, transgene, and cell line dependent.

PubMed

Mulholland, David J; Cox, Michael; Read, Jason; Rennie, Paul; Nelson, Colleen

2004-05-01

Renilla based reporters are frequently used as transfection controls for luciferase transcriptional reporter assays. However, recent evidence suggests that a commonly used reporter (HSV-thymidine kinase driven Renilla) is responsive to androgen receptor (AR) and glucocorticoid receptors in the presence of the cognate ligands, dihydrotestosterone (DHT) and dexamethasone (DEX), respectively [1]. We further validate this important technical difficulty by illustrating that in LNCaP prostate cancer cells, spurious Renilla luciferase activity is a function of (a) the promoter driving Renilla expression, (b) the presence of co-transfected transgenes, and (c) the androgen responsiveness of the cell line used. Using inhibitors of transcription and translation we showed that transcript interference or translational modulation is not a major means by which androgens affect Renilla luciferase activity. As luciferase reporter assays are a frequent means of studying transcriptional co-regulation in the highly androgen dependent LNCaP cell line, our data serves as a cautionary note that alternative normalization techniques should be employed to avoid misinterpretation of data. Copyright 2004 Wiley-Liss, Inc.

The Role of the Co-Chaperone, CHIP, in Androgen-Independent Prostate Cancer

DTIC Science & Technology

2012-02-01

LNCap C4-2 but not in LNCap cells. Figure 9:. CHIP gene expression induced SASH1 gene expression in LNCaP cells but not in LNCap Tsai and LNCap...PCR 16 Gene Product (Gene) C4-2 Cells LNCaP Cells LNCaP Tsai Cells RhoE (RND3) Increased Unchanged Increased SASH1 Unchanged Brief Increase

Phenotypic Characterization of Prostate Cancer LNCaP Cells Cultured within a Bioengineered Microenvironment

PubMed Central

Sieh, Shirly; Taubenberger, Anna V.; Rizzi, Simone C.; Sadowski, Martin; Lehman, Melanie L.; Rockstroh, Anja; An, Jiyuan; Clements, Judith A.; Nelson, Colleen C.; Hutmacher, Dietmar W.

2012-01-01

Biophysical and biochemical properties of the microenvironment regulate cellular responses such as growth, differentiation, morphogenesis and migration in normal and cancer cells. Since two-dimensional (2D) cultures lack the essential characteristics of the native cellular microenvironment, three-dimensional (3D) cultures have been developed to better mimic the natural extracellular matrix. To date, 3D culture systems have relied mostly on collagen and Matrigel™ hydrogels, allowing only limited control over matrix stiffness, proteolytic degradability, and ligand density. In contrast, bioengineered hydrogels allow us to independently tune and systematically investigate the influence of these parameters on cell growth and differentiation. In this study, polyethylene glycol (PEG) hydrogels, functionalized with the Arginine-glycine-aspartic acid (RGD) motifs, common cell-binding motifs in extracellular matrix proteins, and matrix metalloproteinase (MMP) cleavage sites, were characterized regarding their stiffness, diffusive properties, and ability to support growth of androgen-dependent LNCaP prostate cancer cells. We found that the mechanical properties modulated the growth kinetics of LNCaP cells in the PEG hydrogel. At culture periods of 28 days, LNCaP cells underwent morphogenic changes, forming tumor-like structures in 3D culture, with hypoxic and apoptotic cores. We further compared protein and gene expression levels between 3D and 2D cultures upon stimulation with the synthetic androgen R1881. Interestingly, the kinetics of R1881 stimulated androgen receptor (AR) nuclear translocation differed between 2D and 3D cultures when observed by immunofluorescent staining. Furthermore, microarray studies revealed that changes in expression levels of androgen responsive genes upon R1881 treatment differed greatly between 2D and 3D cultures. Taken together, culturing LNCaP cells in the tunable PEG hydrogels reveals differences in the cellular responses to androgen stimulation between the 2D and 3D environments. Therefore, we suggest that the presented 3D culture system represents a powerful tool for high throughput prostate cancer drug testing that recapitulates tumor microenvironment. PMID:22957009

PTTG1, A novel androgen responsive gene is required for androgen-induced prostate cancer cell growth and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Zheng; Jin, Bo; Jin, Yaqiong

Androgens (AR) play an important role in initiation and progression of prostate cancer. It has been shown that AR exert their effects mainly through the androgen-activated AR which binds to androgen response elements (AREs) in the regulatory regions of target genes to regulate the transcription of androgen-responsive genes, thus, identification of AR downstream target gene is critical to understand androgen function in prostate cancer. In this study, our results showed that androgen treatment of LNCaP cells induced PTTG1 expression, which was blocked by the androgen receptor antagonist, Casodex. Bioinformatics analysis and experiments using PTTG1 promoter deletion mutants showed that themore » PTTG1 promoter contains a putative androgen response element (ARE), which localizes in the −851 to −836 region of the promoter. Androgen activated androgen receptor (AR) binding to this ARE was confirmed by Chromatin immunoprecipitation (ChIP) assay. Furthermore, Knockdown of PTTG1 expression using short hairpin RNA significantly reduced androgen-induced LNCaP cell growth and invasion. In addition, we showed PTTG1 is highly expressed in metastasis prostate cancer tissue. These results suggest that PTTG1 is a novel downstream target gene of androgen receptor and take part in prostate cancer proliferation and metastasis. - Highlights: • Androgen treatment of LNCaP cells induced PTTG1 expression. • Knockdown of PTTG1 expression significantly reduced androgen-induced LNCaP cell growth and invasion. • PTTG1 is highly expressed in metastasis prostate cancer tissue. • PTTG1 is a novel downstream target gene of androgen receptor.« less

Pomegranate Polyphenols Downregulate Expression of Androgen Synthesizing Genes in Human Prostate Cancer Cells Overexpressing the Androgen Receptor

PubMed Central

Hong, Mee Young; Seeram, Navindra P.; Heber, David

2008-01-01

Prostate cancer is dependent on circulating testosterone in its early stages and is treatable with radiation and surgery. However, recurrent prostate tumors advance to an androgen-independent state where they progress in the absence of circulating testosterone leading to metastasis and death. During the development of androgen independence, prostate cancer cells are known to increase intracellular testosterone synthesis which maintains cancer cell growth in the absence of significant amounts of circulating testosterone. Overexpression of the androgen receptor (AR) occurs in androgen-independent prostate cancer and has been proposed as another mechanism promoting the development of androgen independence. The LNCaP-AR cell line is engineered to overexpress AR but is otherwise similar to the widely studied LNCaP cell line. We have previously shown that pomegranate extracts inhibit both androgen-dependent and androgen-independent prostate cancer cell growth. In the present study, we examined the effects of pomegranate polyphenols, ellagitannin-rich extract and whole juice extract on the expression of genes for key androgen synthesizing enzymes and the AR. We measured expression of the HSD3B2, AKR1C3 and SRD5A1 genes for the respective androgen synthesizing enzymes in LNCaP, LNCaP-AR, and DU-145 human prostate cancer cells. A two-fold suppression of gene expression was considered statistically significant. Pomegranate polyphenols inhibited gene expression and AR most consistently in the LNCaP-AR cell line (P =.05). Therefore, inhibition by pomegranate polyphenols of gene expression involved in androgen synthesis enzymes and the AR may be of particular importance in androgen-independent prostate cancer cells and the subset of human prostate cancers where AR is upregulated. PMID:18479901

Establishment of prostate cancer spheres from a prostate cancer cell line after phenethyl isothiocyanate treatment and discovery of androgen-dependent reversible differentiation between sphere and neuroendocrine cells.

PubMed

Chen, Yamei; Cang, Shundong; Han, Liying; Liu, Christina; Yang, Patrick; Solangi, Zeeshan; Lu, Quanyi; Liu, Delong; Chiao, J W

2016-05-03

Prostate cancer can transform from androgen-responsive to an androgen-independent phenotype. The mechanism responsible for the transformation remains unclear. We studied the effects of an epigenetic modulator, phenethyl isothiocyanate (PEITC), on the androgen-responsive LNCaP cells. After treatment with PEITC, floating spheres were formed with characteristics of prostate cancer stem cells (PCSC). These spheres were capable of self-renewal in media with and without androgen. They have been maintained in both types of media as long term cultures. Upon androgen deprivation, the adherent spheres differentiated to neuroendocrine cells (NEC) with decreased proliferation, expression of androgen receptor, and PSA. NEC reverse differentiated to spheres when androgen was replenished. The sphere cells expressed surface marker CD44 and had enhanced histone H3K4 acetylation, DNMT1 down-regulation and GSTP1 activation. We hypothesize that PEITC-mediated alteration in epigenomics of LNCaP cells may give rise to sphere cells, whereas reversible androgenomic alterations govern the shuttling between sphere PCSC and progeny NEC. Our findings identify unrecognized properties of prostate cancer sphere cells with multi-potential plasticity. This system will facilitate development of novel therapeutic agents and allow further exploration into epigenomics and androgenomics governing the transformation to hormone refractory prostate cancer.

Neurotensin is an autocrine trophic factor stimulated by androgen withdrawal in human prostate cancer.

PubMed Central

Sehgal, I; Powers, S; Huntley, B; Powis, G; Pittelkow, M; Maihle, N J

1994-01-01

After therapeutic hormone deprivation, prostate cancer cells often develop androgen-insensitive growth through mechanisms thus far undefined. Neuropeptides have been previously implicated as growth factors in some prostate cancers. Here, we demonstrate that androgen-sensitive LNCaP human prostate cancer cells produce and secrete neurotensin following androgen withdrawal. We show that while LNCaP cells express the neurotensin receptor, only androgen-deprived cells exhibit a growth response to exogenous neurotensin. We further demonstrate that androgen-stimulated cells may be refractory to exogenous neurotensin due to androgen induction of a metalloprotease active toward neurotensin. Thus, prostate cancer cells deprived of androgen develop an alternative autocrine growth mechanism involving neurotensin. Images PMID:8197117

Red Maca (Lepidium meyenii) did not affect cell viability despite increased androgen receptor and prostate-specific antigen gene expression in the human prostate cancer cell line LNCaP.

PubMed

Díaz, P; Cardenas, H; Orihuela, P A

2016-10-01

We examined whether aqueous extract of Lepidium meyenii (red Maca) could inhibit growth, potentiate apoptotic activity of two anticancer drugs Taxol and 2-methoxyestradiol (2ME) or change mRNA expression for the androgen target genes, androgen receptor (Ar) and prostate-specific antigen (Psa) in the human prostate cancer cell line LNCaP. Red Maca aqueous extract at 0, 10, 20, 40 or 80 μg/ml was added to LNCaP cells, and viability was evaluated by the MTS assay at 24 or 48 hr after treatment. Furthermore, LNCaP cells were treated with 80 μg/ml of red Maca plus Taxol or 2ME 5 μM and viability was assessed 48 hr later. Finally, LNCaP cells were treated with red Maca 0, 20, 40 or 80 μg/ml, and 12 hr later, mRNA level for Ar or Psa was assessed by real-time PCR. Treatment with red Maca did not affect viability of LNCaP cells. Apoptotic activity induced by Taxol and 2ME in LNCaP cells was not altered with red Maca treatment. Relative expression of the mRNA for Ar and Psa increased with red Maca 20 and 40 μg/ml, but not at 80 μg/ml. We conclude that red Maca aqueous extract does not have toxic effects, but stimulates androgen signalling in LNCaP cells. © 2016 Blackwell Verlag GmbH.

Antiandrogenic mechanisms of pesticides in human LNCaP prostate and H295R adrenocortical carcinoma cells.

PubMed

Robitaille, Christina N; Rivest, Patricia; Sanderson, J Thomas

2015-01-01

Several pesticides suspected or known to have endocrine disrupting effects were screened for pro- or antiandrogenic properties by determining their effects on proliferation, prostatic-specific antigen (PSA) secretion and androgen receptor (AR) expression, and AR phosphorylation in androgen-dependent LNCaP human prostate cancer cells, as well as on the expression and catalytic activity of the enzyme CYP17 in H295R human adrenocortical carcinoma cells, an in vitro model of steroidogenesis. Effects on SRD5A gene expression were determined in both cell lines. Benomyl, vinclozolin, and prochloraz, but not atrazine, concentration dependently (1-30 μM) decreased dihydrotestosterone (DHT)-stimulated proliferation of LNCaP cells. All pesticides except atrazine decreased DHT-stimulated PSA secretion, AR nuclear accumulation, and AR phosphorylation on serines 81 and 213 in LNCaP cells. Benomyl and prochloraz, but not vinclozolin or atrazine, decreased levels of CYP17 gene and protein expression, as well as catalytic activity in H295R cells. In the case of prochloraz, some of these effects corresponded with cytotoxicity. H295R cells expressed AR protein and SRD5A1, but not SRD5A2 transcripts. SRD5A1 gene expression in H295R cells was increased by 10 nM DHT, whereas in LNCaP cells significant induction was observed by 0.1 nM DHT. AR protein expression in H295R cells was not increased by DHT. Vinclozolin decreased DHT-induced SRD5A1 gene expression in LNCaP, but not H295R cells, indicating a functional difference of AR between the cell lines. In conclusion, pesticides may exert antiandrogenic effects through several mechanisms that are cell type-specific, including AR antagonism and down-regulation or catalytic inhibition of androgen biosynthetic enzymes, such as CYP17 and SRD5A1. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Paracrine interactions between LNCaP prostate cancer cells and bioengineered bone in 3D in vitro culture reflect molecular changes during bone metastasis.

PubMed

Sieh, Shirly; Taubenberger, Anna V; Lehman, Melanie L; Clements, Judith A; Nelson, Colleen C; Hutmacher, Dietmar W

2014-06-01

As microenvironmental factors such as three-dimensionality and cell-matrix interactions are increasingly being acknowledged by cancer biologists, more complex 3D in vitro models are being developed to study tumorigenesis and cancer progression. To better understand the pathophysiology of bone metastasis, we have established and validated a 3D indirect co-culture model to investigate the paracrine interactions between prostate cancer (PCa) cells and human osteoblasts. Co-culture of the human PCa, LNCaP cells embedded within polyethylene glycol hydrogels with human osteoblasts in the form of a tissue engineered bone construct (TEB), resulted in reduced proliferation of LNCaP cells. LNCaP cells in both monoculture and co-culture were responsive to the androgen analog, R1881, as indicated by an increase in the expression (mRNA and/or protein induction) of androgen-regulated genes including prostate specific antigen and fatty acid synthase. Microarray gene expression analysis further revealed an up-regulation of bone markers and other genes associated with skeletal and vasculature development and a significant activation of transforming growth factor β1 downstream genes in LNCaP cells after co-culture with TEB. LNCaP cells co-cultured with TEB also unexpectedly showed similar changes in classical androgen-responsive genes under androgen-deprived conditions not seen in LNCaP monocultures. The molecular changes of LNCaP cells after co-culturing with TEBs suggest that osteoblasts exert a paracrine effect that may promote osteomimicry and modulate the expression of androgen-responsive genes in LNCaP cells. Taken together, we have presented a novel 3D in vitro model that allows the study of cellular and molecular changes occurring in PCa cells and osteoblasts that are relevant to metastatic colonization of bone. This unique in vitro model could also facilitate cancer biologists to dissect specific biological hypotheses via extensive genomic or proteomic assessments to further our understanding of the PCa-bone crosstalk. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Autophagy modulators sensitize prostate epithelial cancer cell lines to TNF-alpha-dependent apoptosis.

PubMed

Giampietri, Claudia; Petrungaro, Simonetta; Padula, Fabrizio; D'Alessio, Alessio; Marini, Elettra Sara; Facchiano, Antonio; Filippini, Antonio; Ziparo, Elio

2012-11-01

TNF-alpha levels in prostate cancer correlate with the extent of disease and are significantly elevated in the metastatic stage. TNF receptor superfamily controls two distinct signalling cascades, leading to opposite effects, i.e. apoptosis and survival; in prostate cancer TNF-alpha-mediated signalling induces cell survival and resistance to therapy. The apoptosis of prostate epithelial cancer cells LNCaP and PC3 was investigated upon treatment with the autophagy inhibitor 3-methyladenine and the autophagy inducer rapamycin, in combination with TNF-alpha. Cells were exposed to these molecules for 18, 24 and 48 h. Autophagy was assessed via LC3 Western blot analysis; propidium iodide and TUNEL stainings followed by flow cytometry or caspase-8 and caspase-3 activation assays were performed to evaluate apoptosis. TNF-alpha-induced apoptosis was potentiated by 3-methyladenine in the androgen-responsive LNCaP cells, whereas no effect was observed in the androgen-insensitive PC3 cells. Interestingly such pro-apoptosis effect in LNCaP cells was associated with reduced c-Flip levels through proteasomal degradation via increased reactive oxygen species production and p38 activation; such c-Flip reduction was reversed in the presence of either the proteasome inhibitor MG132 or the reactive oxygen species scavenger N-acetyl-cysteine. Conversely in PC3 but not in LNCaP cells, rapamycin stimulated TNF-alpha-dependent apoptosis; such effect was associated with reduced c-Flip promoter activity and FoxO3a activation. We conclude that TNF-alpha-induced apoptosis may be potentiated, in prostate cancer epithelial cells, through autophagy modulators. Increased sensitivity to TNF-alpha-dependent apoptosis correlates with reduced c-Flip levels which are consequent to a post-transcriptional and a transcriptional mechanism in LNCaP and PC3 cells respectively.

Oligomeric proanthocyanidin complexes (OPC) exert anti-proliferative and pro-apoptotic effects on prostate cancer cells.

PubMed

Neuwirt, Hannes; Arias, Mercedes Cedeno; Puhr, Martin; Hobisch, Alfred; Culig, Zoran

2008-11-01

Oligomeric proanthocyanidin complexes (OPC) are extracted from grape seeds or maritime pine bark and have been used for enhancement of capillary stability and lymphatic drainage. Since a role for OPC in cancer prevention was postulated, we asked whether they have an effect on prostate cancer cells. Cell proliferation was determined by (3)H-thymidine assay and cell cycle status was analyzed on a flow cytometer. Expression of regulators of proliferation and apoptosis was determined by Western blot. We found that androgen-responsive cells LNCaP are more sensitive to OPC in terms of inhibition of proliferation in comparison to androgen receptor-negative PC3 or DU145 cells. Treatment with OPC resulted in a decrease in the percentage of LNCaP cells in the S phase and an increase in the percentage of cells in sub G1 phase. The anti-proliferative and pro-apoptotic effect of OPC in the LNCaP cell line was associated with down-regulation of expression of the androgen receptor. Interestingly, similar regulatory effects of OPC, such as inhibition of expression of cyclin-dependent kinases and cyclins and stimulation of tumor suppressors p21 and p27, were seen in LNCaP and PC3 cells. Favorable changes in the Bcl-2/Bax ratio were observed in LNCaP and PC3 cells after the treatment with OPC. OPC caused an increase of phosphorylated mitogen-activated protein kinase p44 and p42, thus suggesting induction of cellular differentiation. We conclude that OPC is a candidate that fulfills criteria for chemopreventive strategies in prostate cancer that might be established in following in vivo studies. (c) 2008 Wiley-Liss, Inc.

Overexpression of Aldo-Keto Reductase 1C3 (AKR1C3) in LNCaP Cells Diverts Androgen Metabolism towards Testosterone Resulting in Resistance to the 5α-Reductase Inhibitor Finasteride

PubMed Central

Byrns, Michael C.; Mindnich, Rebekka; Duan, Ling; Penning, Trevor M.

2012-01-01

Type 5 17β-hydroxysteroid dehydrogenase (AKR1C3) is the major enzyme in the prostate that reduces 4-androstene-3,17-dione (Δ4-Adione) to the androgen receptor (AR) ligand testosterone. AKR1C3 is upregulated in prostate cancer (PCa) and castrate resistant prostate cancer (CRPC) that develops after androgen deprivation therapy. PCa and CRPC often depend on intratumoral androgen biosynthesis and upregulation of AKR1C3 could contribute to intracellular synthesis of AR ligands and stimulation of proliferation through AR signalling. To test this hypothesis, we developed an LNCaP prostate cancer cell line overexpressing AKR1C3 (LNCaP-AKR1C3) and compared its metabolic and proliferative responses to Δ4-Adione treatment with that of the parental, AKR1C3 negative LNCaP cells. In LNCaP and LNCaP-AKR1C3 cells, metabolism proceeded via 5α-reduction to form 5α-androstane-3,17-dione and then (epi)androsterone-3-glucuronide. LNCaP-AKR1C3 cells made significantly higher amounts of testosterone-17β-glucuronide. When 5α-reductase was inhibited by finasteride, the production of testosterone-17β-glucuronide was further elevated in LNCaP-AKR1C3 cells. When AKR1C3 activity was inhibited with indomethacin the production of testosterone-17β-glucuronide was significantly decreased. Δ4-Adione treatment stimulated cell proliferation in both cell lines. Finasteride inhibited LNCaP cell proliferation, consistent with 5α-androstane-3,17-dione acting as the major metabolite that stimulates growth by binding to the mutated AR. However, LNCaP-AKR1C3 cells were resistant to the growth inhibitory properties of finasteride, consistent with the diversion of Δ4-Adione metabolism from 5α-reduced androgens to increased formation of testosterone. Indomethacin did not result in differences in Δ4-Adione induced proliferation since this treatment led to the same metabolic profile in LNCaP and LNCaP-AKR1C3 cells. We conclude that AKR1C3 overexpression diverts androgen metabolism to testosterone that results in proliferation in androgen sensitive prostate cancer. This effect is seen despite high levels of uridine glucuronosyl transferases suggesting that AKR1C3 activity can surmount the effects of this elimination pathway. Treatment options in prostate cancer that target 5α-reductase where AKR1C3 co-exists may be less effective due to the diversion of Δ4-Adione to testosterone. PMID:22265960

Artemisinin disrupts androgen responsiveness of human prostate cancer cells by stimulating the 26S proteasome-mediated degradation of the androgen receptor protein.

PubMed

Steely, Andrea M; Willoughby, Jamin A; Sundar, Shyam N; Aivaliotis, Vasiliki I; Firestone, Gary L

2017-10-01

Androgen receptor (AR) expression and activity is highly linked to the development and progression of prostate cancer and is a target of therapeutic strategies for this disease. We investigated whether the antimalarial drug artemisinin, which is a sesquiterpene lactone isolated from the sweet wormwood plant Artemisia annua, could alter AR expression and responsiveness in cultured human prostate cancer cell lines. Artemisinin treatment induced the 26S proteasome-mediated degradation of the receptor protein, without altering AR transcript levels, in androgen-responsive LNCaP prostate cancer cells or PC-3 prostate cancer cells expressing exogenous wild-type AR. Furthermore, artemisinin stimulated AR ubiquitination and AR receptor interactions with the E3 ubiquitin ligase MDM2 in LNCaP cells. The artemisinin-induced loss of AR protein prevented androgen-responsive cell proliferation and ablated total AR transcriptional activity. The serine/threonine protein kinase AKT-1 was shown to be highly associated with artemisinin-induced proteasome-mediated degradation of AR protein. Artemisinin treatment activated AKT-1 enzymatic activity, enhanced receptor association with AKT-1, and induced AR serine phosphorylation. Treatment of LNCaP cells with the PI3-kinase inhibitor LY294002, which inhibits the PI3-kinase-dependent activation of AKT-1, prevented the artemisinin-induced AR degradation. Furthermore, in transfected receptor-negative PC-3 cells, artemisinin failed to stimulate the degradation of an altered receptor protein (S215A/S792A) with mutations in its two consensus AKT-1 serine phosphorylation sites. Taken together, our results indicate that artemisinin induces the degradation of AR protein and disrupts androgen responsiveness of human prostate cancer cells, suggesting that this natural compound represents a new potential therapeutic molecule that selectively targets AR levels.

Androgen receptor requires JunD as a coactivator to switch on an oxidative stress generation pathway in prostate cancer cells.

PubMed

Mehraein-Ghomi, Farideh; Basu, Hirak S; Church, Dawn R; Hoffmann, F Michael; Wilding, George

2010-06-01

Relatively high oxidative stress levels in the prostate are postulated to be a major factor for prostate carcinogenesis and prostate cancer (CaP) progression. We focused on elucidating metabolic pathways of oxidative stress generation in CaP cells. Previously, we showed that the transcription factor JunD is essential for androgen-induced reactive oxygen species (ROS) production in androgen-dependent human CaP cells. We also recently showed that androgen induces the first and regulatory enzyme spermidine/spermine N1-acetyltransferase (SSAT) in a polyamine catabolic pathway that produces copious amounts of metabolic ROS. Here, we present coimmunoprecipitation and Gaussia luciferase reconstitution assay data that show that JunD forms a complex with androgen-activated androgen receptor (AR) in situ. Our chromatin immunoprecipitation assay data show that JunD binds directly to a specific SSAT promoter sequence only in androgen-treated LNCaP cells. Using a vector containing a luciferase reporter gene connected to the SSAT promoter and a JunD-silenced LNCaP cell line, we show that JunD is essential for androgen-induced SSAT gene expression. The elucidation of JunD-AR complex inducing SSAT expression leading to polyamine oxidation establishes the mechanistic basis of androgen-induced ROS production in CaP cells and opens up a new prostate-specific target for CaP chemopreventive/chemotherapeutic drug development. Copyright 2010 AACR.

Hormone treatment enhances WT1 activation of Renilla luciferase constructs in LNCaP cells.

PubMed

Hanson, Julie; Reese, Jennifer; Gorman, Jacquelyn; Cash, Jennifer; Fraizer, Gail

2007-01-01

The zinc finger transcription factor, WT1, regulates many growth control genes, repressing or activating transcription depending on the gene and cell type. Based on earlier analyses of the effect of WT1 on androgen responsive genes, we hypothesized that there may be an interaction between the androgen signaling pathway and WT1, such that the commonly used Renilla luciferase control vectors were activated in LNCaP prostate cancer cells. Using cotransfection assays we tested the effects of WT1 and/or the androgen analog, R1881, on two Renilla luciferase vectors, pRL-SV40 and the promoter-less pRL-null. To determine whether the zinc finger DNA binding domain was required, the zinc finger mutant DDS-WT1 (R394W) was tested; but it had no significant effect on the Renilla luciferase vectors. To determine whether the androgen signaling pathway was required, WT1 was co-transfected with Renilla vectors in cells with varied hormone responsiveness. The WT1 effect on pRL-null varied from no significant effect in 293 and PC3 cells to very strong enhancement in LNCaP cells treated with 5 nM R1881. Overall, these results suggest that hormone enhanced WT1 mediated activation of Renilla luciferase and that these interactions require an intact WT1 zinc finger DNA binding domain.

17-ABAG, a novel geldanamycin derivative, inhibits LNCaP-cell proliferation through heat shock protein 90 inhibition

PubMed Central

LIN, ZHIYUAN; PENG, RUIXIAN; LI, ZHENYU; WANG, YANG; LU, CHUNHUA; SHEN, YUEMAO; WANG, JIFENG; SHI, GUOWEI

2015-01-01

Prostate cancer is one of the most common cancer types worldwide. In 2014, there were an estimated 233,000 new cases and 29,480 mortalities in the United States. Androgen deprivation therapy, also called androgen suppression therapy, targets androgen signaling and remains the standard treatment for patients with advanced prostate cancer; however, responses to treatment are not durable and most patients advance to castrate-resistant prostate cancer. Therefore, novel therapeutic strategies to treat prostate cancer are urgently required. Heat shock protein 90 (Hsp90) is a chaperone protein that has been shown to regulate the progression of tumor cells. Numerous Hsp90 inhibitors show anti-tumor activity and several of them have entered clinical trials. Geldanamycin (GA) was identified as the first Hsp90 inhibitor, but shows hepatotoxicity at its effective concentrations, limiting its clinical use. In previous studies by our group, the GA derivative 17-ABAG was designed and synthesized. The present study showed that 17-ABAG inhibits the proliferation and induces apoptosis of LNCaP, an androgen-dependent prostate cancer cell line, in vitro through a classic apoptotic pathway. 17-ABAG also downregulated the Hsp90 client protein and inhibited androgen receptor nuclear localization in LNCaP cells. In addition, 17-ABAG suppressed the growth of LNCaP xenograft tumors without any obvious side-effects. The present study demonstrated that 17-ABAG is a promising anti-tumor agent and warrants further validation in prospective studies. PMID:26059743

Abhydrolase domain containing 2, an androgen target gene, promotes prostate cancer cell proliferation and migration.

PubMed

Obinata, Daisuke; Takada, Shogo; Takayama, Ken-ichi; Urano, Tomohiko; Ito, Akiko; Ashikari, Daisaku; Fujiwara, Kyoko; Yamada, Yuta; Murata, Taro; Kumagai, Jinpei; Fujimura, Tetsuya; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Homma, Yukio; Takahashi, Satoru; Inoue, Satoshi

2016-04-01

The androgen receptor (AR) plays a key role in the development of prostate cancer. AR signalling mediates the expression of androgen-responsive genes, which are involved in prostate cancer development and progression. Our previous chromatin immunoprecipitation study showed that the region of abhydrolase domain containing 2 (ABHD2) includes a functional androgen receptor binding site. In this study, we demonstrated that ABHD2 is a novel androgen-responsive gene that is overexpressed in human prostate cancer tissues. The expression levels of ABHD2 in androgen-sensitive cells were evaluated by quantitative reverse transcription polymerase chain reaction and western-blot analyses. LNCaP and VCaP cells with ABHD2 overexpression or short interfering RNA (siRNA) knockdown were used for functional analyses. ABHD2 expression was examined in clinical samples of prostate cancer by immunohistochemistry. We showed that ABHD2 expression is increased by androgen in LNCaP and VCaP cells. This androgen-induced ABHD2 expression was diminished by bicalutamide. While stable expression of ABHD2 affected the enhancement of LNCaP cell proliferation and migration, siRNA-mediated ABHD2 knockdown suppressed cell proliferation and migration. In addition, the siRNA treatment significantly repressed the tumour growth derived from LNCaP cells in athymic mice. Immunohistochemical analysis of ABHD2 expression in tumour specimens showed a positive correlation of ABHD2 immunoreactivity with high Gleason score and pathological N stage. Moreover, patients with high immunoreactivity of ABHD2 showed low cancer-specific survival rates and a resistance to docetaxel-based chemotherapy. ABHD2 is a novel androgen-regulated gene that can promote prostate cancer growth and resistance to chemotherapy, and is a novel target for diagnosis and treatment of prostate cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dietary phenethyl isothiocyanate inhibition of androgen-responsive LNCaP prostate cancer cell tumor growth correlates with decreased angiogenesis

USDA-ARS?s Scientific Manuscript database

Phenethyl isothiocyanate (PEITC), found in certain cruciferous vegetables, has antitumor activity in several cancer models, including prostate cancer. In our xenograft model, dietary administration of PEITC (100-150 mg/kg/d) inhibited androgen-responsive LNCaP human prostate cancer cell tumor growth...

Sphingosine Kinase-1 Is Central to Androgen-Regulated Prostate Cancer Growth and Survival

PubMed Central

Dayon, Audrey; Brizuela, Leyre; Martin, Claire; Mazerolles, Catherine; Pirot, Nelly; Doumerc, Nicolas; Nogueira, Leonor; Golzio, Muriel; Teissié, Justin; Serre, Guy; Rischmann, Pascal; Malavaud, Bernard; Cuvillier, Olivier

2009-01-01

Background Sphingosine kinase-1 (SphK1) is an oncogenic lipid kinase notably involved in response to anticancer therapies in prostate cancer. Androgens regulate prostate cancer cell proliferation, and androgen deprivation therapy is the standard of care in the management of patients with advanced disease. Here, we explored the role of SphK1 in the regulation of androgen-dependent prostate cancer cell growth and survival. Methodology/Principal Findings Short-term androgen removal induced a rapid and transient SphK1 inhibition associated with a reduced cell growth in vitro and in vivo, an event that was not observed in the hormono-insensitive PC-3 cells. Supporting the critical role of SphK1 inhibition in the rapid effect of androgen depletion, its overexpression could impair the cell growth decrease. Similarly, the addition of dihydrotestosterone (DHT) to androgen-deprived LNCaP cells re-established cell proliferation, through an androgen receptor/PI3K/Akt dependent stimulation of SphK1, and inhibition of SphK1 could markedly impede the effects of DHT. Conversely, long-term removal of androgen support in LNCaP and C4-2B cells resulted in a progressive increase in SphK1 expression and activity throughout the progression to androgen-independence state, which was characterized by the acquisition of a neuroendocrine (NE)-like cell phenotype. Importantly, inhibition of the PI3K/Akt pathway—by negatively impacting SphK1 activity—could prevent NE differentiation in both cell models, an event that could be mimicked by SphK1 inhibitors. Fascinatingly, the reversability of the NE phenotype by exposure to normal medium was linked with a pronounced inhibition of SphK1 activity. Conclusions/Significance We report the first evidence that androgen deprivation induces a differential effect on SphK1 activity in hormone-sensitive prostate cancer cell models. These results also suggest that SphK1 activation upon chronic androgen deprivation may serve as a compensatory mechanism allowing prostate cancer cells to survive in androgen-depleted environment, giving support to its inhibition as a potential therapeutic strategy to delay/prevent the transition to androgen-independent prostate cancer. PMID:19956567

Androgen deprivation results in time-dependent hypoxia in LNCaP prostate tumours: informed scheduling of the bioreductive drug AQ4N improves treatment response.

PubMed

Ming, Louise; Byrne, Niall M; Camac, Sarah Nicole; Mitchell, Christopher A; Ward, Claire; Waugh, David J; McKeown, Stephanie R; Worthington, Jenny

2013-03-15

Androgen withdrawal induces hypoxia in androgen-sensitive tissue; this is important as in the tumour microenvironment, hypoxia is known to drive malignant progression. Our study examined the time-dependent effect of androgen deprivation therapy (ADT) on tumour oxygenation and investigated the role of ADT-induced hypoxia on malignant progression in prostate tumours. LNCaP xenografted tumours were treated with anti-androgens and tumour oxygenation measured. Dorsal skin fold (DSF) chambers were used to image tumour vasculature in vivo. Quantitative PCR (QPCR) identified differential gene expression following treatment with bicalutamide. Bicalutamide-treated and vehicle-only-treated tumours were re-established in vitro, and invasion and sensitivity to docetaxel were measured. Tumour growth delay was calculated following treatment with bicalutamide combined with the bioreductive drug AQ4N. Tumour oxygenation measurements showed a precipitate decrease following initiation of ADT. A clinically relevant dose of bicalutamide (2 mg/kg/day) decreased tumour oxygenation by 45% within 24 hr, reaching a nadir of 0.09% oxygen (0.67 ± 0.06 mmHg) by Day 7; this persisted until Day 14 when it increased up to Day 28. Using DSF chambers, LNCaP tumours treated with bicalutamide showed loss of small vessels at Days 7 and 14 with revascularisation occurring by Day 21. QPCR showed changes in gene expression consistent with the vascular changes and malignant progression. Cells from bicalutamide-treated tumours were more malignant than vehicle-treated controls. Combining bicalutamide with AQ4N (50 mg/kg, single dose) caused greater tumour growth delay than bicalutamide alone. Our study shows that bicalutamide-induced hypoxia selects for cells that show malignant progression; targeting hypoxic cells may provide greater clinical benefit. Copyright © 2012 UICC.

Relating Androgen Receptor Conformation to Function in Prostate Cancer Cells

DTIC Science & Technology

2005-01-01

line development , but have made progress towards resolving these issues and in development of alternate strategies. Task 1. Development of AR and...conformation. Task 2. Development of LNCaP Cells to Express Human AR mutants. We experienced unexpected difficulties in Task 2. We transfected the TET...Coactivators in AR Transactivation Summary Androgens drive sex differentiation, bone and muscle development , and promote growth of hormone dependent cancers

Non-THC cannabinoids inhibit prostate carcinoma growth in vitro and in vivo: pro-apoptotic effects and underlying mechanisms.

PubMed

De Petrocellis, Luciano; Ligresti, Alessia; Schiano Moriello, Aniello; Iappelli, Mariagrazia; Verde, Roberta; Stott, Colin G; Cristino, Luigia; Orlando, Pierangelo; Di Marzo, Vincenzo

2013-01-01

Cannabinoid receptor activation induces prostate carcinoma cell (PCC) apoptosis, but cannabinoids other than Δ(9) -tetrahydrocannabinol (THC), which lack potency at cannabinoid receptors, have not been investigated. Some of these compounds antagonize transient receptor potential melastatin type-8 (TRPM8) channels, the expression of which is necessary for androgen receptor (AR)-dependent PCC survival. We tested pure cannabinoids and extracts from Cannabis strains enriched in particular cannabinoids (BDS), on AR-positive (LNCaP and 22RV1) and -negative (DU-145 and PC-3) cells, by evaluating cell viability (MTT test), cell cycle arrest and apoptosis induction, by FACS scans, caspase 3/7 assays, DNA fragmentation and TUNEL, and size of xenograft tumours induced by LNCaP and DU-145 cells. Cannabidiol (CBD) significantly inhibited cell viability. Other compounds became effective in cells deprived of serum for 24 h. Several BDS were more potent than the pure compounds in the presence of serum. CBD-BDS (i.p.) potentiated the effects of bicalutamide and docetaxel against LNCaP and DU-145 xenograft tumours and, given alone, reduced LNCaP xenograft size. CBD (1-10 µM) induced apoptosis and induced markers of intrinsic apoptotic pathways (PUMA and CHOP expression and intracellular Ca(2+)). In LNCaP cells, the pro-apoptotic effect of CBD was only partly due to TRPM8 antagonism and was accompanied by down-regulation of AR, p53 activation and elevation of reactive oxygen species. LNCaP cells differentiated to androgen-insensitive neuroendocrine-like cells were more sensitive to CBD-induced apoptosis. These data support the clinical testing of CBD against prostate carcinoma. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

Afzelin exhibits anti-cancer activity against androgen-sensitive LNCaP and androgen-independent PC-3 prostate cancer cells through the inhibition of LIM domain kinase 1.

PubMed

Zhu, Kai-Chang; Sun, Jian-Mei; Shen, Jian-Guo; Jin, Ji-Zhong; Liu, Feng; Xu, Xiao-Lin; Chen, Lin; Liu, Lin-Tao; Lv, Jia-Ju

2015-10-01

Prostate cancer presents high occurrence worldwide. Medicinal plants are a major source of novel and potentially therapeutic molecules; therefore, the aim of the present study was to investigate the possible anti-prostate cancer activity of afzelin, a flavonol glycoside that was previously isolated from Nymphaea odorata . The effect of afzelin on the proliferation of androgen-sensitive LNCaP and androgen-independent PC-3 cells was evaluated by performing a water soluble tetrazolium salt-1 assay. In addition, the effect of afzelin on the cell cycle of the LNCaP and PC-3 prostate cancer cell lines was evaluated. Western blot analysis was performed to evaluate the effect of afzelin on the kinases responsible for the regulation of actin organization. Afzelin was identified to inhibit the proliferation of LNCaP and PC3 cells, and block the cell cycle in the G 0 phase. The anticancer activity of afzelin in these cells was determined to be due to inhibition of LIM domain kinase 1 expression. Thus, the in vitro efficacy of afzelin against prostate cancer is promising; however, additional studies on different animal models are required to substantiate its anticancer potential.

Afzelin exhibits anti-cancer activity against androgen-sensitive LNCaP and androgen-independent PC-3 prostate cancer cells through the inhibition of LIM domain kinase 1

PubMed Central

ZHU, KAI-CHANG; SUN, JIAN-MEI; SHEN, JIAN-GUO; JIN, JI-ZHONG; LIU, FENG; XU, XIAO-LIN; CHEN, LIN; LIU, LIN-TAO; LV, JIA-JU

2015-01-01

Prostate cancer presents high occurrence worldwide. Medicinal plants are a major source of novel and potentially therapeutic molecules; therefore, the aim of the present study was to investigate the possible anti-prostate cancer activity of afzelin, a flavonol glycoside that was previously isolated from Nymphaea odorata. The effect of afzelin on the proliferation of androgen-sensitive LNCaP and androgen-independent PC-3 cells was evaluated by performing a water soluble tetrazolium salt-1 assay. In addition, the effect of afzelin on the cell cycle of the LNCaP and PC-3 prostate cancer cell lines was evaluated. Western blot analysis was performed to evaluate the effect of afzelin on the kinases responsible for the regulation of actin organization. Afzelin was identified to inhibit the proliferation of LNCaP and PC3 cells, and block the cell cycle in the G0 phase. The anticancer activity of afzelin in these cells was determined to be due to inhibition of LIM domain kinase 1 expression. Thus, the in vitro efficacy of afzelin against prostate cancer is promising; however, additional studies on different animal models are required to substantiate its anticancer potential. PMID:26622852

Action mechanism and signal pathways of Psidium guajava L. aqueous extract in killing prostate cancer LNCaP cells.

PubMed

Chen, Kuan-Chou; Peng, Chiung-Chi; Chiu, Wen-Ta; Cheng, Yu-Ting; Huang, Guan-Ta; Hsieh, Chiu-Lan; Peng, Robert Y

2010-01-01

Aqueous extract of Psidium guajava L. budding leaves (PE) has been shown to possess anti-prostate cancer activity in a cell line model. We examined whether its bioactivity could be conserved either in the presence or the absence of synthetic androgen R1881. In both cases, PE was shown to inhibit LNCaP cell proliferation and down-regulate expressions of androgen receptor (AR) and prostate specific antigen (PSA). The cytotoxicity of PE was shown by enhanced LDH release in LNCaP cells. The flow cytometry analysis revealed cell cycle arrests at G(0)/G(1) phase with huge amount of apoptotic LNCaP cells after treatment with PE for 48 h in a dose-responsive manner, which was also confirmed by TUNEL assay. From the results of decreased Bcl-2/Bax ratio, inactivation of phosphor-Akt, activation of phosphor-p38, phospho-Erk1/phospho-Erk2, the molecular action mechanism of PE to induce apoptosis in LNCaP cells was elucidated. Compatible with the in vitro study findings, treatment with PE (1.5 mg/mouse/day) significantly diminished both the PSA serum levels and tumor size in a xenograft mouse tumor model. Conclusively, PE is a promising anti-androgen-sensative prostate cancer agent.

Compounds from Cynomorium songaricum with Estrogenic and Androgenic Activities Suppress the Oestrogen/Androgen-Induced BPH Process.

PubMed

Wang, Xueni; Tao, Rui; Yang, Jing; Miao, Lin; Wang, Yu; Munyangaju, Jose Edouard; Wichai, Nuttapong; Wang, Hong; Zhu, Yan; Liu, Erwei; Chang, Yanxu; Gao, Xiumei

2017-01-01

To investigate the phytoestrogenic and phytoandrogenic activities of compounds isolated from CS and uncover the role of CS in prevention of oestrogen/androgen-induced BPH. Cells were treated with CS compounds, and immunofluorescence assay was performed to detect the nuclear translocation of ER α or AR in MCF-7 or LNCaP cells; luciferase reporter assay was performed to detect ERs or AR transcriptional activity in HeLa or AD293 cells; MTT assay was performed to detect the cell proliferation of MCF-7 or LNCaP cells. Oestrogen/androgen-induced BPH model was established in rat and the anti-BPH, anti-estrogenic, and anti-androgenic activities of CS in vivo were further investigated. The nuclear translocation of ER α was stimulated by nine CS compounds, three of which also stimulated AR translocation. The transcriptional activities of ER α and ER β were induced by five compounds, within which only ECG induced AR transcriptional activity as well. Besides, ECG stimulated the proliferation of both MCF-7 cells and LNCaP cells. CS extract suppressed oestrogen/androgen-induced BPH progress in vivo by downregulation of E2 and T level in serum and alteration of the expressions of ER α , ER β , and AR in the prostate. Our data demonstrates that compounds from CS exhibit phytoestrogenic and phytoandrogenic activities, which may contribute to inhibiting the oestrogen/androgen-induced BPH development.

The AhR Ligand, TCDD, Regulates Androgen Receptor Activity Differently in Androgen-Sensitive versus Castration-Resistant Human Prostate Cancer Cells.

PubMed

Ghotbaddini, Maryam; Powell, Joann B

2015-07-06

The reported biological effects of TCDD include induction of drug metabolizing enzymes, wasting syndrome and tumor promotion. TCDD elicits most of its effects through binding the aryl hydrocarbon receptor (AhR). TCDD induced degradation of AhR has been widely reported and requires ubiquitination of the protein. The rapid depletion of AhR following TCDD activation serves as a mechanism to modulate AhR mediated gene induction. In addition to inducing AhR degradation, TCDD has been reported to induce degradation of hormone receptors. The studies reported here, evaluate the effect of TCDD exposure on androgen receptor (AR) expression and activity in androgen-sensitive LNCaP and castration-resistant C4-2 prostate cancer cells. Our results show that TCDD exposure does not induce AhR or AR degradation in C4-2 cells. However, both AhR and AR are degraded in LNCaP cells following TCDD exposure. In addition, TCDD enhances AR phosphorylation and induces expression of AR responsive genes in LNCaP cells. Our data reveals that TCDD effect on AR expression and activity differs in androgen-sensitive and castration-resistant prostate cancer cell models.

Prostate Cancer Cells in Different Androgen Receptor Status Employ Different Leucine Transporters.

PubMed

Otsuki, Hideo; Kimura, Toru; Yamaga, Takashi; Kosaka, Takeo; Suehiro, Jun-Ichi; Sakurai, Hiroyuki

2017-02-01

Leucine stimulates cancer cell proliferation through the mTOR pathway, therefore, inhibiting leucine transporters may be a novel therapeutic target for cancer. L-type amino acid transporter (LAT) 1, a Na + -independent amino acid transporter, is highly expressed in many tumor cells. However, leucine transporter(s) in different stages of prostate cancer, particularly in the stages of castration resistance with androgen receptor (AR) expression, is unclear. LNCaP and DU145 and PC-3 cell lines were used as a model of androgen dependent, and metastatic prostate cancer. A new "LN-cr" cell line was established after culturing LNCaP cells for 6 months under androgen-free conditions, which is considered a model of castration resistant prostate cancer (CRPC) with androgen AR expression. The expression of leucine transporters was investigated with quantitative PCR and immunofluorescence. Uptake of 14 C Leucine was examined in the presence or absence of BCH (a pan-LAT inhibitor), JPH203 (an LAT1-specific inhibitor), or Na + . Cell growth was assessed with MTT assay. siRNA studies were performed to evaluate the indispensability of y + LAT2 on leucine uptake and cell viability in LN-cr. Cell viability showed a 90% decrease in the absence of leucine in all four cell lines. LNCaP cells principally expressed LAT3, and their leucine uptake was more than 90% Na + -independent. BCH, but not JPH203, inhibited leucine uptake, and cell proliferation (IC 50BCH :15 mM). DU145 and PC-3 cells predominantly expressed LAT1. Leucine uptake and cell growth were suppressed by BCH or JPH203 in a dose-dependent manner (IC 50BCH : ∼20 mM, IC 50JPH203 : ∼5 µM). In LN-cr cells, Na + -dependent uptake of leucine was 3.8 pmol/mgprotein/min, while, Na + -independent uptake was only 0.52 (P < 0.05). Leucine uptake of LN-cr was largely (∼85%) Na + -dependent. y + LAT2 expression was confirmed in LN-cr. Knockdown of y + LAT2 lead to significant leucine uptake inhibition (40%) and cell growth inhibition (20%). New CRPC cell line with increased expression of y + LAT2 as a leucine transporter was established in vitro. Anti-leucine transporter therapy could be an important option against prostate cancer. Prostate 77:222-233, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Modeling Truncated AR Expression in a Natural Androgen Responsive Environment and Identification of RHOB as a Direct Transcriptional Target

PubMed Central

Tsai, Hui-Chi; Boucher, David L.; Martinez, Anthony; Tepper, Clifford G.; Kung, Hsing-Jien

2012-01-01

Recent studies identifying putative truncated androgen receptor isoforms with ligand-independent activity have shed new light on the acquisition of androgen depletion independent (ADI) growth of prostate cancer. In this study, we present a model system in which a C-terminally truncated variant of androgen receptor (TC-AR) is inducibly expressed in LNCaP, an androgen-dependent cell line, which expresses little truncated receptor. We observed that when TC-AR is overexpressed, the endogenous full length receptor (FL-AR) is transcriptionally downmodulated. This in essence allows us to “replace” FL-AR with TC-AR and compare their individual properties in exactly the same genetic and cellular background, which has not been performed before. We show that the TC-AR translocates to the nucleus, activates transcription of AR target genes in the absence of DHT and is sufficient to confer ADI growth to the normally androgen dependent LNCaP line. We also show that while there is significant overlap in the genes regulated by FL- and TC-AR there are also differences in the respective suites of target genes with each AR form regulating genes that the other does not. Among the genes uniquely activated by TC-AR is RHOB which is shown to be involved in the increased migration and morphological changes observed in LN/TC-AR, suggesting a role of RHOB in the regulation of androgen-independent behavior of prostate cancer cells. PMID:23209612

Bone stroma-derived cells change coregulators recruitment to androgen receptor and decrease cell proliferation in androgen-sensitive and castration-resistant prostate cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villagran, Marcelo A.; Gutierrez-Castro, Francisco A.; Pantoja, Diego F.

Prostate cancer (CaP) bone metastasis is an early event that remains inactive until later-stage progression. Reduced levels of circulating androgens, due to andropause or androgen deprivation therapies, alter androgen receptor (AR) coactivator expression. Coactivators shift the balance towards enhanced AR-mediated gene transcription that promotes progression to androgen-resistance. Disruptions in coregulators may represent a molecular switch that reactivates latent bone metastasis. Changes in AR-mediated transcription in androgen-sensitive LNCaP and androgen-resistant C4-2 cells were analyzed for AR coregulator recruitment in co-culture with Saos-2 and THP-1. The Saos-2 cell line derived from human osteosarcoma and THP-1 cell line representing human monocytes were usedmore » to display osteoblast and osteoclast activity. Increased AR activity in androgen-resistant C4-2 was due to increased AR expression and SRC1/TIF2 recruitment and decreased SMRT/NCoR expression. AR activity in both cell types was decreased over 90% when co-cultured with Saos-2 or THP-1 due to dissociation of AR from the SRC1/TIF2 and SMRT/NCoR coregulators complex, in a ligand-dependent and cell-type specific manner. In the absence of androgens, Saos-2 decreased while THP-1 increased proliferation of LNCaP cells. In contrast, both Saos-2 and THP-1 decreased proliferation of C4-2 in absence and presence of androgens. Global changes in gene expression from both CaP cell lines identified potential cell cycle and androgen regulated genes as mechanisms for changes in cell proliferation and AR-mediated transactivation in the context of bone marrow stroma cells. - Highlights: • Decreased corepressor expression change AR in androgen-resistance prostate cancer. • Bone stroma-derived cells change AR coregulator recruitment in prostate cancer. • Bone stroma cells change cell proliferation in androgen-resistant cancer cells. • Global gene expression in CaP cells is modified by bone stroma cells in co-cultures. • Potential new multi-subunit coactivator complexes for AR in CaP bone metastasis.« less

The Hsp90 Inhibitor, 17-AAG, Prevents the Ligand-Independent Nuclear Localization of Androgen Receptor in Refractory Prostate Cancer Cells

PubMed Central

Saporita, Anthony J.; Ai, Junkui; Wang, Zhou

2010-01-01

BACKGROUND Androgen receptor (AR) is the key molecule in androgen-refractory prostate cancer. Despite androgen ablative conditions, AR remains active and is necessary for the growth of androgen-refractory prostate cancer cells. Nuclear localization of AR is a prerequisite for its transcriptional activation. We examined AR localization in androgen-dependent and androgen-refractory prostate cancer cells. METHODS AND RESULTS We demonstrate increased nuclear localization of a GFP-tagged AR in the absence of hormone in androgen-refractory C4-2 cells compared to parental androgen-sensitive human prostate cancer LNCaP cells. Analysis of AR mutants impaired in ligand-binding indicates that the nuclear localization of AR in C4-2 cells is truly androgen-independent. The hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), inhibits basal PSA expression and disrupts the ligand-independent nuclear localization of AR at doses much lower than required to inhibit androgen-induced nuclear import. CONCLUSIONS Hsp90 is a key regulator of ligand-independent nuclear localization and activation of AR in androgen-refractory prostate cancer cells. PMID:17221841

Anticancer activity of the protein kinase C modulator HMI-1a3 in 2D and 3D cell culture models of androgen-responsive and androgen-unresponsive prostate cancer.

PubMed

Jäntti, Maria H; Talman, Virpi; Räsänen, Kati; Tarvainen, Ilari; Koistinen, Hannu; Tuominen, Raimo K

2018-05-01

Prostate cancer is one of the most common cancers in men. Although it has a relatively high 5-year survival rate, development of resistance to standard androgen-deprivation therapy is a significant clinical problem. Therefore, novel therapeutic strategies are urgently needed. The protein kinase C (PKC) family is a putative prostate cancer drug target, but so far no PKC-targeting drugs are available for clinical use. By contrast to the standard approach of developing PKC inhibitors, we have developed isophthalate derivatives as PKC agonists. In this study, we have characterized the effects of the most potent isophthalate, 5-(hydroxymethyl)isophthalate 1a3 (HMI-1a3), on three prostate cancer cell lines (LNCaP, DU145, and PC3) using both 2D and 3D cell culture models. In 2D cell culture, HMI-1a3 reduced cell viability or proliferation in all cell lines as determined by the metabolic activity of the cells (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay) and thymidine incorporation. However, the mechanism of action in LNCaP cells was different to that in DU145 or PC3 cells. In LNCaP cells, HMI-1a3 induced a PKC-dependent activation of caspase 3/7, indicating an apoptotic response, whereas in DU145 and PC3 cells, it induced senescence, which was independent of PKC. This was observed as typical senescent morphology, increased β-galactosidase activity, and upregulation of the senescence marker p21 and downregulation of E2F transcription factor 1. Using a multicellular spheroid model, we further showed that HMI-1a3 affects the growth of LNCaP and DU145 cells in a 3D culture, emphasizing its potential as a lead compound for cancer drug development.

Non-THC cannabinoids inhibit prostate carcinoma growth in vitro and in vivo: pro-apoptotic effects and underlying mechanisms

PubMed Central

De Petrocellis, Luciano; Ligresti, Alessia; Schiano Moriello, Aniello; Iappelli, Mariagrazia; Verde, Roberta; Stott, Colin G; Cristino, Luigia; Orlando, Pierangelo; Di Marzo, Vincenzo

2013-01-01

BACKGROUND AND PURPOSE Cannabinoid receptor activation induces prostate carcinoma cell (PCC) apoptosis, but cannabinoids other than Δ9-tetrahydrocannabinol (THC), which lack potency at cannabinoid receptors, have not been investigated. Some of these compounds antagonize transient receptor potential melastatin type-8 (TRPM8) channels, the expression of which is necessary for androgen receptor (AR)-dependent PCC survival. EXPERIMENTAL APPROACH We tested pure cannabinoids and extracts from Cannabis strains enriched in particular cannabinoids (BDS), on AR-positive (LNCaP and 22RV1) and -negative (DU-145 and PC-3) cells, by evaluating cell viability (MTT test), cell cycle arrest and apoptosis induction, by FACS scans, caspase 3/7 assays, DNA fragmentation and TUNEL, and size of xenograft tumours induced by LNCaP and DU-145 cells. KEY RESULTS Cannabidiol (CBD) significantly inhibited cell viability. Other compounds became effective in cells deprived of serum for 24 h. Several BDS were more potent than the pure compounds in the presence of serum. CBD-BDS (i.p.) potentiated the effects of bicalutamide and docetaxel against LNCaP and DU-145 xenograft tumours and, given alone, reduced LNCaP xenograft size. CBD (1–10 µM) induced apoptosis and induced markers of intrinsic apoptotic pathways (PUMA and CHOP expression and intracellular Ca2+). In LNCaP cells, the pro-apoptotic effect of CBD was only partly due to TRPM8 antagonism and was accompanied by down-regulation of AR, p53 activation and elevation of reactive oxygen species. LNCaP cells differentiated to androgen-insensitive neuroendocrine-like cells were more sensitive to CBD-induced apoptosis. CONCLUSIONS AND IMPLICATIONS These data support the clinical testing of CBD against prostate carcinoma. LINKED ARTICLE This article is commented on by Pacher et al., pp. 76–78 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2012.02121.x PMID:22594963

Study of NGEP expression in androgen sensitive prostate cancer cells: A potential target for immunotherapy

PubMed Central

Mohsenzadegan, Monireh; Tajik, Nader; Madjd, Zahra; Shekarabi, Mehdi; Farajollahi, Mohammad M

2015-01-01

Background: Prostate cancer is one of the leading causes of cancer deaths among men. New gene expressed in prostate (NGEP), is a prostate-specific gene expressed only in normal prostate and prostate cancer tissue. Because of its selective expression in prostate cancer cell surface, NGEP is a potential immunotherapeutic target. To target the NGEP in prostate cancer, it is essential to investigate its expression in prostate cancer cells. Methods: In the present study, we investigated NGEP expression in LNCaP and DU145 cells by real time and RT-PCR, flow cytometric and immunocytochemical analyses. Results: Real time and RT-PCR analyses of NGEP expression showed that NGEP was expressed in the LNCaP cells but not in DU145 cells. The detection of NGEP protein by flow cytometric and immunocytochemistry analyses indicated that NGEP protein was weakly expressed only in LNCaP cell membrane. Conclusion: Our results demonstrate that LNCaP cell line is more suitable than DU145 for NGEP expression studies; however, its low-level expression is a limiting issue. NGEP expression may be increased by androgen supplementation of LNCaP cell culture medium. PMID:26000254

Androgen-induced Long Noncoding RNA (lncRNA) SOCS2-AS1 Promotes Cell Growth and Inhibits Apoptosis in Prostate Cancer Cells*

PubMed Central

Misawa, Aya; Takayama, Ken-ichi; Urano, Tomohiko; Inoue, Satoshi

2016-01-01

Long noncoding RNAs (lncRNA) have been associated with the development of cancer. However, the interplay between lncRNAs and androgen receptor (AR) signaling in prostate cancer is still unclear. Here, we identified lncRNAs induced by androgen in AR-positive prostate cancer cells, where induction was abolished by AR knockdown as well as an anti-androgen, bicalutamide. By combining these data, we identified an androgen-regulated lncRNA, suppressor of cytokine signaling 2-antisense transcript 1 (SOCS2-AS1), the expression of which was higher in castration-resistant prostate cancer model cells, i.e. long-term androgen-deprived (LTAD) cells, than in parental androgen-dependent LNCaP cells. SOCS2-AS1 promoted castration-resistant and androgen-dependent cell growth. We found that SOCS2-AS1 knockdown up-regulated genes related to the apoptosis pathway, including tumor necrosis factor superfamily 10 (TNFSF10), and sensitized prostate cancer cells to docetaxel treatment. Moreover, we also demonstrated that SOCS2-AS1 promotes androgen signaling by modulating the epigenetic control for AR target genes including TNFSF10. These findings suggest that SOCS2-AS1 plays an important role in the development of castration-resistant prostate cancer by repressing apoptosis. PMID:27342777

Design, synthesis and biological evaluation of novel 3-oxo-4-oxa-5α-androst-17β-amide derivatives as dual 5α-reductase inhibitors and androgen receptor antagonists.

PubMed

Lao, Kejing; Sun, Jie; Wang, Chong; Wang, Ying; You, Qidong; Xiao, Hong; Xiang, Hua

2017-09-01

Prostate cancer (PCa) is the second leading cause of death in men. Recently, some researches have showed that 5α-reductase inhibitors were beneficial in PCa treatment as well. In this study, a series of novel 3-oxo-4-oxa-5α-androst-17β-amide derivatives have been designed and synthesized in a more simple and convenient method. Most of the synthesized compounds displayed good 5α-reductase inhibitory activities and androgen receptor binding affinities. Their anti-proliferation activities in PC-3 and LNCaP cell lines were also evaluated and the results indicated that most of the synthesized compounds exhibited potent anti-proliferative activities. It is obvious that the androgen-dependent cell line LNCaP was much more sensitive than the androgen-independent cell line PC-3. Among all the synthesized compounds, 11d and 11k displayed the best inhibition activity with 4-fold more sensitive toward LNCaP than PC-3, which was consistent with their high affinities observed in AR binding assay. Molecular modeling studies suggested that 11k could bind to AR in a manner similar to the binding of dihydrotestosterone to AR. Compared to the finasteride, 11k showed a longer plasma half-life (4h) and a better bioavailability. Overall, based on biological activities data, compound 11d and 11k can be identified as potential dual 5α-reductase inhibitors and AR antagonists which might be of therapeutic importance for prostate cancer treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quercetin increased the antiproliferative activity of green tea polyphenol (−)-epigallocatechin gallate in prostate cancer cells

PubMed Central

Wang, Piwen; Heber, David; Henning, Susanne M.

2012-01-01

We previously demonstrated that 50% of (−)-epigallocatechin gallate (EGCG) was present in methylated form (4″-MeEGCG) in human prostate tissue, which is less bioactive. We therefore investigated whether quercetin, a natural inhibitor of catechol-O-methyl transferase (COMT), will inhibit EGCG methylation leading to enhanced antiproliferative activity of EGCG in prostate cancer cells. Incubation with both, quercetin and EGCG, for 2 hr increased the cellular concentrations of EGCG by 4 to 8-fold and 6 to 10-fold in androgen-independent PC-3 cells and androgen-dependent LNCaP cells, respectively. Concurrently, the percent of 4″-MeEGCG in the total EGCG was decreased from 39% to 15% in PC-3 cells and from 61% to 38% in LNCaP cells. Quercetin and EGCG in combination synergistically inhibited cell proliferation, caused cell cycle arrest and induced apoptosis in PC-3 cells. In LNCaP cells EGCG and quercetin exhibited a stronger antiproliferative activity leading to an additive effect. The synergistic effect of these two agents in PC-3 cells could be based on the fact that EGCG primarily inhibited COMT activity while quercetin reduced the amount of COMT protein. In summary, quercetin combined with EGCG in vitro demonstrated enhanced inhibition of cell proliferation by increasing the intracellular concentration of EGCG and decreasing EGCG methylation. PMID:22452782

Glutathione S-transferase Pi mediates proliferation of androgen-independent prostate cancer cells

PubMed Central

Hokaiwado, Naomi; Takeshita, Fumitaka; Naiki-Ito, Aya; Asamoto, Makoto; Ochiya, Takahiro; Shirai, Tomoyuki

2008-01-01

Prostate cancers generally acquire an androgen-independent growth capacity with progression, resulting in resistance to antiandrogen therapy. Therefore, identification of the genes regulated through this process may be important for understanding the mechanisms of prostate carcinogenesis. We here utilized androgen-dependent/independent transplantable tumors, newly established with the ‘transgenic rat adenocarcinoma in prostate’ (TRAP) model, to analyze their gene expression using microarrays. Among the overexpressed genes in androgen-independent prostate cancers compared with the androgen-dependent tumors, glutathione S-transferase pi (GST-pi) was included. In line with this, human prostate cancer cell lines PC3 and DU145 (androgen independent) had higher expression of GST-pi compared with LNCaP (androgen dependent) as determined by semiquantitative reverse transcription–polymerase chain reaction analysis. To investigate the roles of GST-pi expression in androgen-independent human prostate cancers, GST-pi was knocked down by a small interfering RNA (siRNA), resulting in significant decrease of the proliferation rate in the androgen-independent PC3 cell line. In vivo, administration of GST-pi siRNA–atelocollagen complex decreased GST-pi protein expression, resulting in enhanced numbers of TdT mediated dUTP-biotin nick-end labering (TUNEL)-positive apoptotic cells. These findings suggest that GST-pi might play important roles in proliferation of androgen-independent human prostate cancer cells. PMID:18413363

FBI-1 functions as a novel AR co-repressor in prostate cancer cells.

PubMed

Cui, Jiajun; Yang, Yutao; Zhang, Chuanfu; Hu, Pinliang; Kan, Wei; Bai, Xianhong; Liu, Xuelin; Song, Hongbin

2011-03-01

The pro-oncogene FBI-1, encoded by Zbtb7a, is a transcriptional repressor that belongs to the POK (POZ/BTB and Krüppel) protein family. In this study, we investigated a potential interaction between androgen receptor (AR) signaling and FBI-1 and demonstrated that overexpression of FBI-1 inhibited ligand-dependent AR activation. A protein-protein interaction was identified between FBI-1 and AR in a ligand-dependent manner. Furthermore, FBI-1, AR and SMRT formed a ternary complex and FBI-1 enhanced the recruitment of NCoR and SMRT to endogenous PSA upstream sequences. Our data also indicated that the FBI-1-mediated inhibition of AR transcriptional activity is partially dependent on HDAC. Interestingly, FBI-1 plays distinct roles in regulating LNCaP (androgen-dependent) and PC-3 cell (androgen-independent) proliferation.

Pleiotropic effects of the sirtuin inhibitor sirtinol involves concentration-dependent modulation of multiple nuclear receptor-mediated pathways in the androgen-responsive prostate cancer cell LNCaP

USDA-ARS?s Scientific Manuscript database

Sirtinol, a purported specific inhibitor of the nicotinamide adenine dinucleotide (NAD)-dependent type III histone deacetylase (also known as sirtuin), has been used extensively to identify chemopreventive/chemotherapeutic agents that modulate the activity of this group of enzymes. However, the mole...

Androgen Receptor and its Splice Variant, AR-V7, Differentially Regulate FOXA1 Sensitive Genes in LNCaP Prostate Cancer Cells

PubMed Central

Krause, William C.; Shafi, Ayesha A.; Nakka, Manjula; Weigel, Nancy L.

2014-01-01

Prostate cancer (PCa) is an androgen-dependent disease, and tumors that are resistant to androgen ablation therapy often remain androgen receptor (AR) dependent. Among the contributors to castration-resistant PCa are AR splice variants that lack the ligand-binding domain (LBD). Instead, they have small amounts of unique sequence derived from cryptic exons or from out of frame translation. The AR-V7 (or AR3) variant is constitutively active and is expressed under conditions consistent with CRPC. AR-V7 is reported to regulate a transcriptional program that is similar but not identical to that of AR. However, it is unknown whether these differences are due to the unique sequence in AR-V7, or simply to loss of the LBD. To examine transcriptional regulation by AR-V7, we have used lentiviruses encoding AR-V7 (amino acids 1-627 of AR with the 16 amino acids unique to the variant) to prepare a derivative of the androgen-dependent LNCaP cells with inducible expression of AR-V7. An additional cell line was generated with regulated expression of AR-NTD (amino acids 1-660 of AR); this mutant lacks the LBD but does not have the AR-V7 specific sequence. We find that AR and AR-V7 have distinct activities on target genes that are co-regulated by FOXA1. Transcripts regulated by AR-V7 were similarly regulated by AR-NTD, indicating that loss of the LBD is sufficient for the observed differences. Differential regulation of target genes correlates with preferential recruitment of AR or AR-V7 to specific cis-regulatory DNA sequences providing an explanation for some of the observed differences in target gene regulation. PMID:25008967

Restoration of the cellular secretory milieu overrides androgen dependence of in vivo generated castration resistant prostate cancer cells overexpressing the androgen receptor.

PubMed

Patki, Mugdha; Huang, Yanfang; Ratnam, Manohar

2016-07-22

It is believed that growth of castration resistant prostate cancer (CRPC) cells is enabled by sensitization to minimal residual post-castrate androgen due to overexpression of the androgen receptor (AR). Evidence is derived from androgen-induced colony formation in the absence of cell-secreted factors or from studies involving forced AR overexpression in hormone-dependent cells. On the other hand, standard cell line models established from CRPC patient tumors (e.g., LNCaP and VCaP) are hormone-dependent and require selection pressure in castrated mice to re-emerge as CRPC cells and the resulting tumors then tend to be insensitive to the androgen antagonist enzalutamide. Therefore, we examined established CRPC model cells produced by castration of mice bearing hormone-dependent cell line xenografts including CRPC cells overexpressing full-length AR (C4-2) or co-expressing wtAR and splice-variant AR-V7 that is incapable of ligand binding (22Rv1). In standard colony formation assays, C4-2 cells were shown to be androgen-dependent and sensitive to enzalutamide whereas 22Rv1 cells were incapable of colony formation under identical conditions. However, both C4-2 and 22Rv1 cells formed colonies in conditioned media derived from the same cells or from HEK293 fibroblasts that were proven to lack androgenic activity. This effect was (i) not enhanced by androgen, (ii) insensitive to enzalutamide, (iii) dependent on AR (in C4-2) and on AR-V7 and wtAR (in 22Rv1) and (iv) sensitive to inhibitors of several signaling pathways, similar to androgen-stimulation. Therefore, during progression to CRPC in vivo, coordinate cellular changes accompanying overexpression of AR may enable cooperation between hormone-independent activity of AR and actions of cellular secretory factors to completely override androgen-dependence and sensitivity to drugs targeting hormonal factors. Copyright © 2016 Elsevier Inc. All rights reserved.

TLR3 engagement induces IRF-3-dependent apoptosis in androgen-sensitive prostate cancer cells and inhibits tumour growth in vivo

PubMed Central

Gambara, Guido; Desideri, Marianna; Stoppacciaro, Antonella; Padula, Fabrizio; De Cesaris, Paola; Starace, Donatella; Tubaro, Andrea; del Bufalo, Donatella; Filippini, Antonio; Ziparo, Elio; Riccioli, Anna

2015-01-01

Toll-like receptors (TLRs) are a family of highly conserved transmembrane proteins expressed in epithelial and immune cells that recognize pathogen associated molecular patterns. Besides their role in immune response against infections, numerous studies have shown an important role of different TLRs in cancer, indicating these receptors as potential targets for cancer therapy. We previously demonstrated that the activation of TLR3 by the synthetic double-stranded RNA analogue poly I:C induces apoptosis of androgen-sensitive prostate cancer (PCa) LNCaP cells and, much less efficiently, of the more aggressive PC3 cell line. Therefore, in this study we selected LNCaP cells to investigate the mechanism of TLR3-mediated apoptosis and the in vivo efficacy of poly I:C-based therapy. We show that interferon regulatory factor-3 (IRF-3) signalling plays an essential role in TLR3-mediated apoptosis in LNCaP cells through the activation of the intrinsic and extrinsic apoptotic pathways. Interestingly, hardly any apoptosis was induced by poly I:C in normal prostate epithelial cells RWPE-1. We also demonstrate for the first time the direct anticancer effect of poly I:C as a single therapeutic agent in a well-established human androgen-sensitive PCa xenograft model, by showing that tumour growth is highly impaired in poly I:C-treated immunodeficient mice. Immunohistochemical analysis of PCa xenografts highlights the antitumour role of poly I:C in vivo both on cancer cells and, indirectly, on endothelial cells. Notably, we show the presence of TLR3 and IRF-3 in both human normal and PCa clinical samples, potentially envisaging poly I:C-based therapy for PCa. PMID:25444175

The antiandrogenic effect of finasteride against a mutant androgen receptor

PubMed Central

Chhipa, Rishi Raj; Zhang, Haitao; Ip, Clement

2011-01-01

Finasteride is known to inhibit Type 2 5α-reductase and thus block the conversion of testosterone to dihydrotestosterone (DHT). The structural similarity of finasteride to DHT raises the possibility that finasteride may also interfere with the function of the androgen receptor (AR). Experiments were carried out to evaluate the antiandrogenic effect of finasteride in LNCaP, C4-2 and VCaP human prostate cancer cells. Finasteride decreased DHT binding to AR, and DHT-stimulated AR activity and cell growth in LNCaP and C4-2 cells, but not in VCaP cells. LNCaP and C4-2 (derived from castration-resistant LNCaP) cells express the T877A mutant AR, while VCaP cells express the wild-type AR. When PC-3 cells, which are AR-null, were transfected with either the wild-type or the T877A mutant AR, only the mutant AR-expressing cells were sensitive to finasteride inhibition of DHT binding. Peroxiredoxin-1 (Prx1) is a novel endogenous facilitator of AR binding to DHT. In Prx1-rich LNCaP cells, the combination of Prx1 knockdown and finasteride was found to produce a greater inhibitory effect on AR activity and cell growth than either treatment alone. The observation suggests that cells with a low expression of Prx1 are likely to be more responsive to the antiandrogenic effect of finasteride. Additional studies showed that the efficacy of finasteride was comparable to that of bicalutamide (a widely used non-steroidal antiandrogen). The implication of the above findings is discussed in the context of developing strategies to improve the outcome of androgen deprivation therapy. PMID:21386657

Effect of lithium chloride and antineoplastic drugs on survival and cell cycle of androgen-dependent prostate cancer LNCap cells

PubMed Central

Azimian-Zavareh, Vajihe; Hossein, Ghamartaj; Janzamin, Ehsan

2012-01-01

Objective: Glycogen synthase kinase-3β (GSK-3β) has been reported to be required for androgen receptor (AR) activity. This study sought to determine the usefulness of lithium chloride (LiCl) as a highly selective inhibitor of GSK-3β to increase the sensitivity of LNCap cells to doxorubicin (Dox), etoposide (Eto), and vinblastine (Vin) drugs. Materials and Methods: Thiazolyl Blue Tetrazolium Blue (MTT) assay was used to determine the cytotoxic effect to LiCl alone or in combination with low dose and IC50 doses of drugs. Subsequently, cell cycle analysis was performed by using flow cytometry. Results: LiCl showed cytotoxic effect in a dose- and time-dependent manner (P<0.001). Both Dox (100 or 280 nM) and Vin IC50 (5 nM) doses caused G2/M-phase arrest (P<0.001) compared with control. However, low dose (10 μM) or IC50 (70 μM) Eto doses showed G2/M or S-phase arrests, respectively (P<0.001). Combination of low dose or IC50 dose of Eto with LiCl showed increased apoptosis as revealed by high percent of cells in SubG1 (P<0.05, P<0.01, respectively). Moreover, Eto (10 μM) led to decreased percent of cells in G2/M phase when combined with LiCl (P<0.05). Conclusion: This study showed that LiCl increases apoptosis of (LNCap) Lymph Node Carcinoma of the Prostate cells in the presence of Eto, which is S- and G2-phase-specific drug. PMID:23248400

Induction of apoptosis by N-(4-hydroxyphenyl)retinamide and its association with reactive oxygen species, nuclear retinoic acid receptors, and apoptosis-related genes in human prostate carcinoma cells.

PubMed

Sun, S Y; Yue, P; Lotan, R

1999-03-01

The synthetic retinoid N-(4-hydroxyphenyl)retinamide (4HPR) has been shown to induce apoptosis in various malignant cells including human prostate carcinoma cells (HPC). We examined several possible mechanisms by which 4HPR could induce apoptosis in HPC cells. 4HPR exhibited concentration- and time-dependent decrease in cell number both in androgen-dependent (LNCaP) and -independent (DU145 and PC-3) cells. The 4HPR concentrations causing 50% decrease in cell number in LNCaP, DU145, and PC-3 cultures were 0.9 +/- 0.16, 4.4 +/- 0.45, and 3.0 +/- 1.0 microM, respectively, indicating that LNCaP cells were more sensitive to 4HPR than the other cells. 4HPR-induced apoptosis in all three cell lines was evidenced by increased enzymatic labeling of DNA breaks and formation of a DNA ladder. 4HPR increased the level of reactive oxygen species, especially in LNCaP cells. 4HPR-induced apoptosis could be suppressed in LNCaP cells by antioxidant and in DU145 cells by a nuclear retinoic acid receptor-specific antagonist, suggesting the involvement of reactive oxygen species or retinoic acid receptors in mediating apoptosis induced by 4HPR in the different HPC cells. Furthermore, 4HPR modulated the expression levels of some apoptosis-related gene (p21, c-myc, and c-jun), which may also contribute to the induction of apoptosis by 4HPR in HPC cells.

Expression profiles and functional associations of endogenous androgen receptor and caveolin-1 in prostate cancer cell lines.

PubMed

Bennett, Nigel C; Hooper, John D; Johnson, David W; Gobe, Glenda C

2014-05-01

In prostate cancer (PCa) patients, the protein target for androgen deprivation and blockade therapies is androgen receptor (AR). AR interacts with many proteins that function to either co-activate or co-repress its activity. Caveolin-1 (Cav-1) is not found in normal prostatic epithelium, but is found in PCa, and may be an AR co-regulator protein. We investigated cell line-specific signatures and associations of endogenous AR and Cav-1 in six PCa cell lines of known androgen sensitivity: LNCaP (androgen sensitive); 22Rv1 (androgen responsive); PC3, DU145, and ALVA41 (androgen non-reliant); and RWPE1 (non-malignant). Protein and mRNA expression profiles were compared and electron microscopy used to identify cells with caveolar structures. For cell lines expressing both AR and Cav-1, knockdown techniques using small interfering RNA against AR or Cav-1 were used to test whether diminished expression of one affected the other. Co-sedimentation of AR and Cav-1 was used to test their association. A reporter assay for AR genomic activity was utilized following Cav-1 knockdown. AR-expressing LNCaP and 22Rv1 cells had low endogenous Cav-1 mRNA and protein. Cell lines that expressed little or no AR (DU145, PC3, ALVA41, and RWPE1) expressed high endogenous levels of Cav-1. AR knockdown in LNCaP cells had little effect on Cav-1, but Cav-1 knockdown inhibited AR expression and genomic activity. These data show endogenous AR and Cav-1 mRNA and protein expression is inversely related in PCa cells, with Cav-1 acting on the androgen/AR signaling axis possibly as an AR co-activator, demonstrated by diminished AR genomic activity following Cav-1 knockdown. © 2013 Wiley Periodicals, Inc.

Galbanic acid decreases androgen receptor abundance and signaling and induces G1 arrest in prostate cancer cells

PubMed Central

Zhang, Yong; Kim, Kwan-Hyun; Zhang, Wei; Guo, Yinglu; Kim, Sung-Hoon; Lü, Junxuan

2011-01-01

Androgen receptor (AR) signaling is crucial for the genesis and progression of prostate cancer (PCa). We compared the growth responses of AR(+) LNCaP and LNCaP C4-2 vs. AR(−) DU145 and PC-3 PCa cell lines to galbanic acid (GBA) isolated from the resin of medicinal herb Ferula assafoetida and assessed their connection to AR signaling and cell cycle regulatory pathways. Our results showed that GBA preferentially suppressed AR(+) PCa cell growth than AR(−) PCa cells. GBA induced a caspase-mediated apoptosis that was attenuated by a general caspase inhibitor. Subapoptotic GBA down-regulated AR protein in LNCaP cells primarily through promoting its proteasomal degradation, and inhibited AR-dependent transcription without affecting AR nuclear translocation. Whereas docking simulations predicted binding of GBA to the AR ligand binding domain with similarities and differences with the AR antagonist drug bicalutamide, LNCaP cell culture assays did not detect agonist activity of GBA. GBA and bicalutamide exerted greater than additive inhibitory effect on cell growth when used together. Subapoptotic GBA induced G1 arrest associated with an inhibition of cyclin/CDK4/6 pathway, especially cyclin D1 without the causal involvement of CDK inhibitory proteins P21Cip1 and P27Kip1. In summary, the novelty of GBA as an anti-AR compound resides in the distinction between GBA and bicalutamide with respect to AR protein turnover and a lack of agonist effect. Our observations of anti-AR and cell cycle arrest actions plus the anti-angiogenesis effect reported elsewhere suggest GBA as a multi-targeting drug candidate for the prevention and therapy of PCa. PMID:21328348

Sensitization of Prostate Cancer Cells to Androgen Deprivation and Radiation via Manipulation of the MDM2 Pathway

DTIC Science & Technology

2005-04-01

cell number apoptosis, and clonogenic assays of LNCaP- MST. Months 1-6. c. Time course experiments of AS effects on AD, RT, and AD+RT in LNCaP and LNCaP...to AS- MDM2, and have not found much of an effect . More recently, we >" 0" have initiated the measurement of SmRNA expression using the Oligo Pollack...AL, Joon DL, Meistrich M, Hachem P, Pollack A. Effect of sequencing androgen deprivation and radiation on prostate cancer growth. Int J Radiat Oncol

Identification of Novel Androgen-Regulated Pathways and mRNA Isoforms through Genome-Wide Exon-Specific Profiling of the LNCaP Transcriptome

PubMed Central

Carling, Phillippa J.; Buist, Thomas; Zhang, Chaolin; Grellscheid, Sushma N.; Armstrong, Kelly; Stockley, Jacqueline; Simillion, Cedric; Gaughan, Luke; Kalna, Gabriela; Zhang, Michael Q.; Robson, Craig N.; Leung, Hing Y.; Elliott, David J.

2011-01-01

Androgens drive the onset and progression of prostate cancer (PCa) by modulating androgen receptor (AR) transcriptional activity. Although several microarray-based studies have identified androgen-regulated genes, here we identify in-parallel global androgen-dependent changes in both gene and alternative mRNA isoform expression by exon-level analyses of the LNCaP transcriptome. While genome-wide gene expression changes correlated well with previously-published studies, we additionally uncovered a subset of 226 novel androgen-regulated genes. Gene expression pathway analysis of this subset revealed gene clusters associated with, and including the tyrosine kinase LYN, as well as components of the mTOR (mammalian target of rapamycin) pathway, which is commonly dysregulated in cancer. We also identified 1279 putative androgen-regulated alternative events, of which 325 (∼25%) mapped to known alternative splicing events or alternative first/last exons. We selected 30 androgen-dependent alternative events for RT-PCR validation, including mRNAs derived from genes encoding tumour suppressors and cell cycle regulators. Of seven positively-validating events (∼23%), five events involved transcripts derived from alternative promoters of known AR gene targets. In particular, we found a novel androgen-dependent mRNA isoform derived from an alternative internal promoter within the TSC2 tumour suppressor gene, which is predicted to encode a protein lacking an interaction domain required for mTOR inhibition. We confirmed that expression of this alternative TSC2 mRNA isoform was directly regulated by androgens, and chromatin immunoprecipitation indicated recruitment of AR to the alternative promoter region at early timepoints following androgen stimulation, which correlated with expression of alternative transcripts. Together, our data suggest that alternative mRNA isoform expression might mediate the cellular response to androgens, and may have roles in clinical PCa. PMID:22194994

Sarcosine Up-Regulates Expression of Genes Involved in Cell Cycle Progression of Metastatic Models of Prostate Cancer

PubMed Central

Heger, Zbynek; Merlos Rodrigo, Miguel Angel; Michalek, Petr; Polanska, Hana; Masarik, Michal; Vit, Vitezslav; Plevova, Mariana; Pacik, Dalibor; Eckschlager, Tomas; Stiborova, Marie

2016-01-01

The effects of sarcosine on the processes driving prostate cancer (PCa) development remain still unclear. Herein, we show that a supplementation of metastatic PCa cells (androgen independent PC-3 and androgen dependent LNCaP) with sarcosine stimulates cells proliferation in vitro. Similar stimulatory effects were observed also in PCa murine xenografts, in which sarcosine treatment induced a tumor growth and significantly reduced weight of treated mice (p < 0.05). Determination of sarcosine metabolism-related amino acids and enzymes within tumor mass revealed significantly increased glycine, serine and sarcosine concentrations after treatment accompanied with the increased amount of sarcosine dehydrogenase. In both tumor types, dimethylglycine and glycine-N-methyltransferase were affected slightly, only. To identify the effects of sarcosine treatment on the expression of genes involved in any aspect of cancer development, we further investigated expression profiles of excised tumors using cDNA electrochemical microarray followed by validation using the semi-quantitative PCR. We found 25 differentially expressed genes in PC-3, 32 in LNCaP tumors and 18 overlapping genes. Bioinformatical processing revealed strong sarcosine-related induction of genes involved particularly in a cell cycle progression. Our exploratory study demonstrates that sarcosine stimulates PCa metastatic cells irrespectively of androgen dependence. Overall, the obtained data provides valuable information towards understanding the role of sarcosine in PCa progression and adds another piece of puzzle into a picture of sarcosine oncometabolic potential. PMID:27824899

Design, chemical synthesis and biological evaluation of 3-spiromorpholinone/3-spirocarbamate androsterone derivatives as inhibitors of 17β-hydroxysteroid dehydrogenase type 3.

PubMed

Djigoué, Guy Bertrand; Kenmogne, Lucie Carolle; Roy, Jenny; Maltais, René; Poirier, Donald

2015-09-01

17β-Hydroxysteroid dehydrogenase type 3 (17β-HSD3) is a key enzyme involved in the biosynthesis of testosterone and dihydrotestosterone. These hormones are known to stimulate androgen-dependent prostate cancer. In order to generate effective inhibitors of androgen biosynthesis without androgenic effect, we synthesized a new family of 3-spiromorpholinone and 3-spirocarbamate androsterone derivatives bearing diversified hydrophobic groups. We also tested their inhibitory activity in a microsomal fraction of 17β-HSD3-containing rat testes, and their androgenic effect on androgen-sensitive LAPC-4 cells. From our first structure-activity relationship (SAR) study, we noted that compound 7e inhibited 17β-HSD3 (77% at 0.1 μM) compared to our reference compound RM-532-105 (76% at 0.1 μM), but exhibited a residual androgenic effect. A library of 7e analogue compounds was next synthesized in order to generate compounds with reduced androgenic activity. In this new SAR study, the sulfonamide compound 7e21 and the carboxamide compound 7e22 inhibited 17β-HSD3 (IC50 = 28 and 88 nM, respectively). These two compounds were not androgenic and not cytotoxic even at the highest concentration tested, but their inhibitory activity decreased in intact LNCaP cells overexpressing 17β-HSD3 (LNCaP[17β-HSD3]). Structural modifications of these two lead compounds could however be tested to produce a second generation of 17β-HSD3 inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Carbidopa abrogates L-dopa decarboxylase coactivation of the androgen receptor and delays prostate tumor progression.

PubMed

Wafa, Latif A; Cheng, Helen; Plaa, Nathan; Ghaidi, Fariba; Fukumoto, Takahiro; Fazli, Ladan; Gleave, Martin E; Cox, Michael E; Rennie, Paul S

2012-06-15

The androgen receptor (AR) plays a central role in prostate cancer progression to the castration-resistant (CR) lethal state. L-Dopa decarboxylase (DDC) is an AR coactivator that increases in expression with disease progression and is coexpressed with the receptor in prostate adenocarcinoma cells, where it may enhance AR activity. Here, we hypothesize that the DDC enzymatic inhibitor, carbidopa, can suppress DDC-coactivation of AR and retard prostate tumor growth. Treating LNCaP prostate cancer cells with carbidopa in transcriptional assays suppressed the enhanced AR transactivation seen with DDC overexpression and decreased prostate-specific antigen (PSA) mRNA levels. Carbidopa dose-dependently inhibited cell growth and decreased survival in LNCaP cell proliferation and apoptosis assays. The inhibitory effect of carbidopa on DDC-coactivation of AR and cell growth/survival was also observed in PC3 prostate cancer cells (stably expressing AR). In vivo studies demonstrated that serum PSA velocity and tumor growth rates elevated ∼2-fold in LNCaP xenografts, inducibly overexpressing DDC, were reverted to control levels with carbidopa administration. In castrated mice, treating LNCaP tumors, expressing endogenous DDC, with carbidopa delayed progression to the CR state from 6 to 10 weeks, while serum PSA and tumor growth decreased 4.3-fold and 5.4-fold, respectively. Our study is a first time demonstration that carbidopa can abrogate DDC-coactivation of AR in prostate cancer cells and tumors, decrease serum PSA, reduce tumor growth and delay CR progression. Since carbidopa is clinically approved, it may be readily used as a novel therapeutic strategy to suppress aberrant AR activity and delay prostate cancer progression. Copyright © 2011 UICC.

Effects of resveratrol and other wine polyphenols on the proliferation, apoptosis and androgen receptor expression in LNCaP cells.

PubMed

Ferruelo, A; Romero, I; Cabrera, P M; Arance, I; Andrés, G; Angulo, J C

2014-01-01

To address the effect of resveratrol and other red wine polyphenols on cell proliferation, apoptosis and androgen receptor (AR) expression in human prostate cancer LNCaP cells. LNCaP cells (5 × 102) were cultured in microtiter plate modules and treated with gallic acid, tannic acid and quercetin (1, 5 and 10 μM), rutin and morin (25, 50 and 75 μM) and resveratrol (5, 10 and 25 μM). To address the extent of proliferation at 24, 48, 72 and 96 hours, a colorimetric immunoassay method was used. An activity caspase 3/7 detection assay was used to disclose apoptosis at 24, 48 and 72 hours. AR mARN levels were determined by real time RT-PCR. All polyphenols studied significantly inhibited (P<.05) cell proliferation compared to control. However, there were moderate differences between them. Resveratrol was the strongest inhibitor at different times and doses. Also, caspase-3 and caspase-7 activity was significantly higher (P<.05) than control in the presence of all the compounds, but the earlier response was achieved by resveratrol. Resveratrol, quercetin and morin were the only nutrients that significantly inhibited AR mRNA expression. Again resveratrol produced the highest inhibition (90-250 times less than control), followed by morin (67-100 times) and quercetin (55-91 times). All polyphenols studied showed important antiproliferative effects and induced apoptosis when added to LNCaP cells culture. We confirm that resveratrol, morin and quercetin may achieve such effect through reduced expression of AR. The synergistic effects of these compounds and their potential to prevent progression of hormone-dependent prostate cancer merit further study. Copyright © 2014 AEU. Published by Elsevier Espana. All rights reserved.

Structure-based Virtual Screening and Identification of a Novel Androgen Receptor Antagonist*

PubMed Central

Song, Chin-Hee; Yang, Su Hui; Park, Eunsook; Cho, Suk Hee; Gong, Eun-Yeung; Khadka, Daulat Bikram; Cho, Won-Jea; Lee, Keesook

2012-01-01

Hormonal therapies, mainly combinations of anti-androgens and androgen deprivation, have been the mainstay treatment for advanced prostate cancer because the androgen-androgen receptor (AR) system plays a pivotal role in the development and progression of prostate cancers. However, the emergence of androgen resistance, largely due to inefficient anti-hormone action, limits the therapeutic usefulness of these therapies. Here, we report that 6-(3,4-dihydro-1H-isoquinolin-2-yl)-N-(6-methylpyridin-2-yl)nicotinamide (DIMN) acts as a novel anti-androgenic compound that may be effective in the treatment of both androgen-dependent and androgen-independent prostate cancers. Through AR structure-based virtual screening using the FlexX docking model, fifty-four compounds were selected and further screened for AR antagonism via cell-based tests. One compound, DIMN, showed an antagonistic effect specific to AR with comparable potency to that of the classical AR antagonists, hydroxyflutamide and bicalutamide. Consistent with their anti-androgenic activity, DIMN inhibited the growth of androgen-dependent LNCaP prostate cancer cells. Interestingly, the compound also suppressed the growth of androgen-independent C4–2 and CWR22rv prostate cancer cells, which express a functional AR, but did not suppress the growth of the AR-negative prostate cancer cells PPC-1, DU145, and R3327-AT3.1. Taken together, the results suggest that the synthetic compound DIMN is a novel anti-androgen and strong candidate for useful therapeutic agent against early stage to advanced prostate cancer. PMID:22798067

Implication of multiple mechanisms in apoptosis induced by the synthetic retinoid CD437 in human prostate carcinoma cells.

PubMed

Sun, S Y; Yue, P; Lotan, R

2000-09-14

The synthetic retinoid 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) induces apoptosis in several types of cancer cell. CD437 inhibited the growth of both androgen-dependent and -independent human prostate carcinoma (HPC) cells in a concentration-dependent manner by rapid induction of apoptosis. CD437 was more effective in killing androgen-independent HPC cells such as DU145 and PC-3 than the androgen-dependent LNCaP cells. The caspase inhibitors Z-VAD-FMK and Z-DEVD-FMK blocked apoptosis induced by CD437 in DU145 and LNCaP cells, in which increased caspase-3 activity and PARP cleavage were observed, but not in PC-3 cells, in which CD437 did not induce caspase-3 activation and PARP cleavage. Thus, CD437 can induce either caspase-dependent or caspase-independent apoptosis in HPC cells. CD437 increased the expression of c-Myc, c-Jun, c-Fos, and death receptors DR4, DR5 and Fas. CD437's potency in apoptosis induction in the different cell lines was correlated with its effects on the expression of oncogenes and death receptors, thus implicating these genes in CD437-induced apoptosis in HPC cells. However, the importance and contribution of each of these genes in different HPC cell lines may vary. Because CD437 induced the expression of DR4, DR5 and Fas, we examined the effects of combining CD437 and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and Fas ligand, respectively, in HPC cells. We found synergistic induction of apoptosis, highlighting the importance of the modulation of these death receptors in CD437-induced apoptosis in HPC cells. This result also suggests a potential strategy of using CD437 with TRAIL for treatment of HPC. Oncogene (2000) 19, 4513 - 4522.

Cannabinoid receptor-dependent and -independent anti-proliferative effects of omega-3 ethanolamides in androgen receptor-positive and -negative prostate cancer cell lines

PubMed Central

Brown, Iain; Cascio, Maria G.; Wahle, Klaus W.J.; Smoum, Reem; Mechoulam, Raphael; Ross, Ruth A.; Pertwee, Roger G.; Heys, Steven D.

2010-01-01

The omega-3 fatty acid ethanolamides, docosahexaenoyl ethanolamide (DHEA) and eicosapentaenoyl ethanolamide (EPEA), displayed greater anti-proliferative potency than their parent omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in LNCaP and PC3 prostate cancer cells. DHEA and EPEA activated cannabinoid CB1 and CB2 receptors in vitro with significant potency, suggesting that they are endocannabinoids. Both LNCaP and PC3 cells expressed CB1 and CB2 receptors, and the CB1- and CB2-selective antagonists, AM281 and AM630, administered separately or together, reduced the anti-proliferative potencies of EPEA and EPA but not of DHEA or DHA in PC3 cells and of EPA but not of EPEA, DHEA or DHA in LNCaP cells. Even so, EPEA and EPA may not have inhibited PC3 or LNCaP cell proliferation via cannabinoid receptors since the anti-proliferative potency of EPEA was well below the potency it displayed as a CB1 or CB2 receptor agonist. Indeed, these receptors may mediate a protective effect because the anti-proliferative potency of DHEA in LNCaP and PC3 cells was increased by separate or combined administration of AM281 and AM630. The anandamide-metabolizing enzyme, fatty acid amide hydrolase (FAAH), was highly expressed in LNCaP but not PC3 cells. Evidence was obtained that FAAH metabolizes EPEA and DHEA and that the anti-proliferative potencies of these ethanolamides in LNCaP cells can be enhanced by inhibiting this enzyme. Our findings suggest that the expression of cannabinoid receptors and of FAAH in some tumour cells could well influence the effectiveness of DHA and EPA or their ethanolamide derivatives as anticancer agents. PMID:20660502

Targeting Sulfotransferase (SULT) 2B1b as a regulator of Cholesterol Metabolism in Prostate Cancer

DTIC Science & Technology

2016-10-01

Approved for Public Release; Distribution Unlimited The views, opinions and/or findings contained in this report are those of the author(s) and...and PCa cell lines and that genetic knock down suppresses LNCaP growth and diminishes androgen receptor ( AR ) activity. It is hypothesized that SULT2B1b...knock down suppresses LNCaP growth and diminishes androgen receptor ( AR ) activity. It is hypothesized that SULT2B1b modulates PCa growth and

Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takahara, Kiyoshi; Ii, Masaaki, E-mail: masaii@art.osaka-med.ac.jp; Inamoto, Teruo

2014-04-18

Highlights: • AdSC transplantation exhibits inhibitory effect on tumor progressions of PCa cells. • AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway. • High expression of the TGF-β1 gene in AdSCs. - Abstract: Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferationmore » of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.« less

Intratumoral conversion of adrenal androgen precursors drives androgen receptor-activated cell growth in prostate cancer more potently than de novo steroidogenesis.

PubMed

Kumagai, Jinpei; Hofland, Johannes; Erkens-Schulze, Sigrun; Dits, Natasja F J; Steenbergen, Jacobie; Jenster, Guido; Homma, Yukio; de Jong, Frank H; van Weerden, Wytske M

2013-11-01

Despite an initial response to hormonal therapy, patients with advanced prostate cancer (PC) almost always progress to castration-resistant disease (CRPC). Although serum testosterone (T) is reduced by androgen deprivation therapy, intratumoral T levels in CRPC are comparable to those in prostate tissue of eugonadal men. These levels could originate from intratumoral conversion of adrenal androgens and/or from de novo steroid synthesis. However, the relative contribution of de novo steroidogenesis to AR-driven cell growth is unknown. The relative contribution of androgen biosynthetic pathways to activate androgen receptor (AR)-regulated cell growth and expression of PSA, FKBP5, and TMPRSS2 was studied at physiologically relevant levels of adrenal androgen precursors and intermediates of de novo androgen biosynthesis in human prostate cancer cell lines, PC346C, VCaP, and LNCaP. In PC346C and VCaP, responses to pregnenolone and progesterone were absent or minimal, while large effects of adrenal androgen precursors were found. VCaP CRPC clones overexpressing CYP17A1 did not acquire an increased ability to use pregnenolone or progesterone to activate AR. In contrast, all precursors stimulated growth and gene expression in LNCaP cells, presumably resulting from the mutated AR in these cells. Our data indicate that at physiological levels of T precursors PC cells can generally convert adrenal androgens, while de novo steroidogenesis is not generally possible in PC cells and is not able to support AR transactivation and PC growth. © 2013 Wiley Periodicals, Inc.

Effect of Saw Palmetto Supplements on Androgen-Sensitive LNCaP Human Prostate Cancer Cell Number and Syrian Hamster Flank Organ Growth

PubMed Central

Opoku-Acheampong, Alexander B.; Penugonda, Kavitha; Lindshield, Brian L.

2016-01-01

Saw palmetto supplements (SPS) are commonly consumed by men with prostate cancer. We investigated whether SPS fatty acids and phytosterols concentrations determine their growth-inhibitory action in androgen-sensitive LNCaP cells and hamster flank organs. High long-chain fatty acids-low phytosterols (HLLP) SPS ≥ 750 nM with testosterone significantly increased and ≥500 nM with dihydrotestosterone significantly decreased LNCaP cell number. High long-chain fatty acids-high phytosterols (HLHP) SPS ≥ 500 nM with dihydrotestosterone and high medium-chain fatty acids-low phytosterols (HMLP) SPS ≥ 750 nM or with androgens significantly decreased LNCaP cell number (n = 3; p < 0.05). Five- to six-week-old, castrated male Syrian hamsters were randomized to control (n = 4), HLLP, HLHP, and HMLP SPS (n = 6) groups. Testosterone or dihydrotestosterone was applied topically daily for 21 days to the right flank organ; the left flank organ was treated with ethanol and served as the control. Thirty minutes later, SPS or ethanol was applied to each flank organ in treatment and control groups, respectively. SPS treatments caused a notable but nonsignificant reduction in the difference between left and right flank organ growth in testosterone-treated SPS groups compared to the control. The same level of inhibition was not seen in dihydrotestosterone-treated SPS groups (p < 0.05). Results may suggest that SPS inhibit 5α-reductase thereby preventing hamster flank organ growth. PMID:27272436

Effect of Saw Palmetto Supplements on Androgen-Sensitive LNCaP Human Prostate Cancer Cell Number and Syrian Hamster Flank Organ Growth.

PubMed

Opoku-Acheampong, Alexander B; Penugonda, Kavitha; Lindshield, Brian L

2016-01-01

Saw palmetto supplements (SPS) are commonly consumed by men with prostate cancer. We investigated whether SPS fatty acids and phytosterols concentrations determine their growth-inhibitory action in androgen-sensitive LNCaP cells and hamster flank organs. High long-chain fatty acids-low phytosterols (HLLP) SPS ≥ 750 nM with testosterone significantly increased and ≥500 nM with dihydrotestosterone significantly decreased LNCaP cell number. High long-chain fatty acids-high phytosterols (HLHP) SPS ≥ 500 nM with dihydrotestosterone and high medium-chain fatty acids-low phytosterols (HMLP) SPS ≥ 750 nM or with androgens significantly decreased LNCaP cell number (n = 3; p < 0.05). Five- to six-week-old, castrated male Syrian hamsters were randomized to control (n = 4), HLLP, HLHP, and HMLP SPS (n = 6) groups. Testosterone or dihydrotestosterone was applied topically daily for 21 days to the right flank organ; the left flank organ was treated with ethanol and served as the control. Thirty minutes later, SPS or ethanol was applied to each flank organ in treatment and control groups, respectively. SPS treatments caused a notable but nonsignificant reduction in the difference between left and right flank organ growth in testosterone-treated SPS groups compared to the control. The same level of inhibition was not seen in dihydrotestosterone-treated SPS groups (p < 0.05). Results may suggest that SPS inhibit 5α-reductase thereby preventing hamster flank organ growth.

Naringenin-Induced Apoptotic Cell Death in Prostate Cancer Cells Is Mediated via the PI3K/AKT and MAPK Signaling Pathways.

PubMed

Lim, Whasun; Park, Sunwoo; Bazer, Fuller W; Song, Gwonhwa

2017-05-01

Prostate cancer is the most common cancer in men and the second most common cause of cancer-related deaths in men. Although, various drugs targeting the androgen receptor are normally used, the patients frequently undergo recurrence of the disease. To overcome these limitations, natural compounds have been researched for evidence that they suppress progression and metastasis of various cancer cells. In the present study, we investigated effects of naringenin, a natural anti-oxidant flavonoid derived from citrus, on prostate cancer cells (PC3 and LNCaP). Results of present study with PC3 and LNCaP cells revealed that naringenin inhibited proliferation and migration, while inducing apoptosis and ROS production by those cells. In addition, naringenin-induced loss of mitochondrial membrane potential and increased Bax and decreased Bcl-2 proteins in PC3 cells, but not LNCaP cells. In a dose-dependent manner, naringenin decreased phosphorylation of ERK1/2, P70S6K, S6, and P38 in PC3 cells, and reduced phosphorylation of ERK1/2, P53, P38, and JNK proteins in LNCaP cells. However, naringenin activated phosphorylation of AKT in both PC3 and LNCaP cells. Then, targeted signaling proteins associated with viability of PC3 and LNCaP cells were analyzed using pharmacological inhibitors of AKT and ERK1/2 cell signaling pathways. Moreover, we compared the apoptotic effects of naringenin and paclitaxel alone and in combination to find that naringenin enhanced the efficiency of paclitaxel to suppress progression of prostate cancer cell lines. Collectively, these results indicate that naringenin is a potential chemotherapeutic agent for treatment of prostate cancer. J. Cell. Biochem. 118: 1118-1131, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Silibinin derivatives as anti-prostate cancer agents: Synthesis and cell-based evaluations.

PubMed

Vue, Bao; Zhang, Sheng; Zhang, Xiaojie; Parisis, Konstantinos; Zhang, Qiang; Zheng, Shilong; Wang, Guangdi; Chen, Qiao-Hong

2016-02-15

This study aims to systematically explore the alkylation effect of 7-OH in silibinin and 2,3-dehydrosilibinin on the antiproliferative potency toward three prostate cancer cell lines. Eight 7-O-alkylsilibinins, eight 7-O-alkyl-2,3-dehydrosilibinins, and eight 3,7-O-dialkyl-2,3-dehydrosilibinins have been synthesized from commercially available silibinin for the in vitro cell-based evaluation. The WST-1 cell proliferation assay indicates that nineteen out of twenty-four silibinin derivatives have significantly improved antiproliferative potency when compared with silibinin. 7-O-Methylsilibinin (2) and 7-O-ethylsilibinin (3) have been identified as the most potent compounds with 98- and 123-fold enhanced potency against LNCaP human androgen-dependent prostate cancer cell line. Among 2,3-dehydrosilibinin derivatives, 7-O-methyl-2,3-dehydrosilibinin (10) and 7-O-ethyl-2,3-dehydrosilibinin (11) have been identified as the optimal compounds with the highest potency towards both androgen-dependent LNCaP and androgen-independent PC-3 prostate cancer cell lines. 7-O-Ethyl-2,3-dehydrosilibinin (11) was demonstrated to arrest PC-3 cell cycle at the G0/G1 phase and to induce PC-3 cell apoptosis. The findings in this study suggest that antiproliferative potency of silibinin and 2,3-dehydrosilibinin can be appreciably enhanced through suitable chemical modifications on the phenolic hydroxyl group at C-7 and that introduction of a chemical moiety with the potential to improve bioavailability through a linker to 7-OH in silibinin and 2,3-dehydrosilibinin would be a feasible strategy for the development of silibinin derivatives as anti-prostate cancer agents. Published by Elsevier Masson SAS.

The protective effect of soybean phytochemicals on androgen responsive human prostate cancer cells LNCaP is likely mediated through modulation of hormone/cytokine-dependent pathways

USDA-ARS?s Scientific Manuscript database

Population studies suggested that the consumption of a soy rich diet provides protective effects against several chronic diseases including prostate cancer. However, the active components in soy, as well as the mechanisms of action of soy’s protective effects, remain unclear. It would be important t...

Chemical Strategy to Translate Genetic/epigenetic Mechanisms to Breast Cancer Therapeutics

DTIC Science & Technology

2012-07-01

androgen-sensitive LNCaP cells. Early studies suggest that cardiac glycosides inhibit cell pro- liferation through the induction of apoptosis (24–26...We asked whether induced apoptosis was sufficient to account for the strong effect of Peruvoside on inhibiting cell proliferation. By monitoring...activated Caspases 3 and 7, we found that Peruvoside has a de- tectable degree of induced apoptosis on LNCaP cells, but no effect on LNCaP-abl cells (Fig

Mitochondrial Respiratory Function Induces Endogenous Hypoxia

PubMed Central

Prior, Sara; Kim, Ara; Yoshihara, Toshitada; Tobita, Seiji; Takeuchi, Toshiyuki; Higuchi, Masahiro

2014-01-01

Hypoxia influences many key biological functions. In cancer, it is generally believed that hypoxic condition is generated deep inside the tumor because of the lack of oxygen supply. However, consumption of oxygen by cancer should be one of the key means of regulating oxygen concentration to induce hypoxia but has not been well studied. Here, we provide direct evidence of the mitochondrial role in the induction of intracellular hypoxia. We used Acetylacetonatobis [2-(2′-benzothienyl) pyridinato-kN, kC3’] iridium (III) (BTP), a novel oxygen sensor, to detect intracellular hypoxia in living cells via microscopy. The well-differentiated cancer cell lines, LNCaP and MCF-7, showed intracellular hypoxia without exogenous hypoxia in an open environment. This may be caused by high oxygen consumption, low oxygen diffusion in water, and low oxygen incorporation to the cells. In contrast, the poorly-differentiated cancer cell lines: PC-3 and MDAMB231 exhibited intracellular normoxia by low oxygen consumption. The specific complex I inhibitor, rotenone, and the reduction of mitochondrial DNA (mtDNA) content reduced intracellular hypoxia, indicating that intracellular oxygen concentration is regulated by the consumption of oxygen by mitochondria. HIF-1α was activated in endogenously hypoxic LNCaP and the activation was dependent on mitochondrial respiratory function. Intracellular hypoxic status is regulated by glucose by parabolic dose response. The low concentration of glucose (0.045 mg/ml) induced strongest intracellular hypoxia possibly because of the Crabtree effect. Addition of FCS to the media induced intracellular hypoxia in LNCaP, and this effect was partially mimicked by an androgen analog, R1881, and inhibited by the anti-androgen, flutamide. These results indicate that mitochondrial respiratory function determines intracellular hypoxic status and may regulate oxygen-dependent biological functions. PMID:24586439

Characterizing Mechanisms of Resistance to Androgen Deprivation in Prostate Cancer

DTIC Science & Technology

2015-11-01

LNCaP cells, using nextgen sequencing. shRNA-mediated-knock-down and CRISPR -mediated knock-out in vitro experiments, as well as in vivo PCa...short hairpin RNA CRISPR – Clustered Regularly Interspaced Short Palindromic Repeats FBS – Fetal Bovine Serum GFP...targeted CRISPR genomic editing technology. Cas9- expressing LNcaP cells were infected with small guides targeting the AR gene. Unfortunately, only

MicroRNAs Are Mediators of Androgen Action in Prostate and Muscle

PubMed Central

Narayanan, Ramesh; Jiang, Jinmai; Gusev, Yuriy; Jones, Amanda; Kearbey, Jeffrey D.; Miller, Duane D.; Schmittgen, Thomas D.; Dalton, James T.

2010-01-01

Androgen receptor (AR) function is critical for the development of male reproductive organs, muscle, bone and other tissues. Functionally impaired AR results in androgen insensitivity syndrome (AIS). The interaction between AR and microRNA (miR) signaling pathways was examined to understand the role of miRs in AR function. Reduction of androgen levels in Sprague-Dawley rats by castration inhibited the expression of a large set of miRs in prostate and muscle, which was reversed by treatment of castrated rats with 3 mg/day dihydrotestosterone (DHT) or selective androgen receptor modulators. Knockout of the miR processing enzyme, DICER, in LNCaP prostate cancer cells or tissue specifically in mice inhibited AR function leading to AIS. Since the only function of miRs is to bind to 3′ UTR and inhibit translation of target genes, androgens might induce miRs to inhibit repressors of AR function. In concordance, knock-down of DICER in LNCaP cells and in tissues in mice induced the expression of corepressors, NCoR and SMRT. These studies demonstrate a feedback loop between miRs, corepressors and AR and the imperative role of miRs in AR function in non-cancerous androgen-responsive tissues. PMID:21048966

Synergistic co-targeting of prostate-specific membrane antigen and androgen receptor in prostate cancer.

PubMed

Murga, Jose D; Moorji, Sameer M; Han, Amy Q; Magargal, Wells W; DiPippo, Vincent A; Olson, William C

2015-02-15

Antibody-drug conjugates (ADCs) are an emerging class of cancer therapies that have demonstrated favorable activity both as single agents and as components of combination regimens. Phase 2 testing of an ADC targeting prostate-specific membrane antigen (PSMA) in advanced prostate cancer has shown antitumor activity. The present study examined PSMA ADC used in combination with potent antiandrogens (enzalutamide and abiraterone) and other compounds. Antiproliferative activity and expression of PSMA, prostate-specific antigen and androgen receptor were evaluated in the prostate cancer cell lines LNCaP and C4-2. Cells were tested for susceptibility to antiandrogens or other inhibitors, used alone and in combination with PSMA ADC. Potential drug synergy or antagonism was evaluated using the Bliss independence method. Enzalutamide and abiraterone demonstrated robust, statistically significant synergy when combined with PSMA ADC. Largely additive activity was observed between the antiandrogens and the individual components of the ADC (free drug and unmodified antibody). Rapamycin also synergized with PSMA ADC in certain settings. Synergy was linked in part to upregulation of PSMA expression. In androgen-dependent LNCaP cells, enzalutamide and abiraterone each inhibited proliferation, upregulated PSMA expression, and synergized with PSMA ADC. In androgen-independent C4-2 cells, enzalutamide and abiraterone showed no measurable antiproliferative activity on their own but increased PSMA expression and synergized with PSMA ADC nonetheless. PSMA expression increased progressively over 3 weeks with enzalutamide and returned to baseline levels 1 week after enzalutamide removal. The findings support exploration of clinical treatment regimens that combine potent antiandrogens and PSMA-targeted therapies for prostate cancer. © 2014 Wiley Periodicals, Inc.

Role of Hsp90 in Androgen-Refractory Prostate Cancer

DTIC Science & Technology

2010-03-01

designed siRNA sequence using Intergrated DNA Technologies RNAi online software tool (IDT, Coralville, IA). The sequence of siRNA specific for...proliferation and production of prostate-specific antigen in androgen-sensitive pros- tatic cancer cells, LNCaP, by dihydrotestosterone. Endocrinology 136

Development of cell-penetrating bispecific antibodies targeting the N-terminal domain of androgen receptor for prostate cancer therapy.

PubMed

Goicochea, Nancy L; Garnovskaya, Maria; Blanton, Mary G; Chan, Grace; Weisbart, Richard; Lilly, Michael B

2017-12-01

Castration-resistant prostate cancer cells exhibit continued androgen receptor signaling in spite of low levels of ligand. Current therapies to block androgen receptor signaling act by inhibiting ligand production or binding. We developed bispecific antibodies capable of penetrating cells and binding androgen receptor outside of the ligand-binding domain. Half of the bispecific antibody molecule consists of a single-chain variable fragment of 3E10, an anti-DNA antibody that enters cells. The other half is a single-chain variable fragment version of AR441, an anti-AR antibody. The resulting 3E10-AR441 bispecific antibody enters human LNCaP prostate cells and accumulates in the nucleus. The antibody binds to wild-type, mutant and splice variant androgen receptor. Binding affinity of 3E10-AR441 to androgen receptor (284 nM) was lower than that of the parental AR441 mAb (4.6 nM), but could be improved (45 nM) through alternative placement of the affinity tags, and ordering of the VH and VK domains. The 3E10-AR441 bispecific antibody blocked genomic signaling by wild-type or splice variant androgen receptor in LNCaP cells. It also blocked non-genomic signaling by the wild-type receptor. Furthermore, bispecific antibody inhibited the growth of C4-2 prostate cancer cells under androgen-stimulated conditions. The 3E10-AR441 biAb can enter prostate cancer cells and inhibits androgen receptor function in a ligand-independent manner. It may be an attractive prototype agent for prostate cancer therapy. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Osteopontin-c mediates the upregulation of androgen responsive genes in LNCaP cells through PI3K/Akt and androgen receptor signaling.

PubMed

Tilli, Tatiana Martins; Ferreira, Luciana Bueno; Gimba, Etel Rodrigues Pereira

2015-04-01

Androgen receptor (AR) signaling is a key pathway modulating prostate cancer (PCa) progression. Several steps in this pathway have been investigated in order to propose novel treatment strategies for advanced PCa. Total osteopontin (OPN) has been described as a biomarker for PCa, in addition to its role in activating the progression of this tumor. Based on the known effects of the OPNc splice variant on PCa progression, the present study investigated whether this isoform can also modulate AR signaling. In order to test this, an in vitro model was used in which LNCaP cells were cultured in the presence of conditioned medium (CM) secreted by PCa cells overexpressing OPNc (OPNc-CM). The activation of AR signaling was evaluated by measuring the expression levels of AR-responsive genes (ARGs) using quantitative polymerase chain reaction and specific oligonucleotides. The data demonstrated that all nine tested ARGs ( Fgf8 , TMPRSS2 , Greb1 , Cdk2 , Ndrg1 , Cdk1 , Pmepa1 , Psa and Ar ) are significantly upregulated in response to OPNc-CM compared with LNCaP cells cultured in CM secreted by control cells transfected with empty expression vector. The specific involvement of OPNc was demonstrated by depleting OPNc from OPNc-CM using an anti-OPNc neutralizing antibody. In addition, by using a phosphoinositide 3-kinase (PI3K)-specific inhibitor and AR antagonists, such as flutamide and bicalutamide, it was also observed that upregulation of ARGs in response to OPNc-CM involves PI3K signaling and depends on the AR. In conclusion, these data indicated that OPNc is able to activate AR signaling through the PI3K pathway and the AR. These data further corroborate our previous data, revealing the OPNc splice variant to be a key molecule that is able to modulate key signaling pathways involved in PCa progression.

Osteopontin-c mediates the upregulation of androgen responsive genes in LNCaP cells through PI3K/Akt and androgen receptor signaling

PubMed Central

TILLI, TATIANA MARTINS; FERREIRA, LUCIANA BUENO; GIMBA, ETEL RODRIGUES PEREIRA

2015-01-01

Androgen receptor (AR) signaling is a key pathway modulating prostate cancer (PCa) progression. Several steps in this pathway have been investigated in order to propose novel treatment strategies for advanced PCa. Total osteopontin (OPN) has been described as a biomarker for PCa, in addition to its role in activating the progression of this tumor. Based on the known effects of the OPNc splice variant on PCa progression, the present study investigated whether this isoform can also modulate AR signaling. In order to test this, an in vitro model was used in which LNCaP cells were cultured in the presence of conditioned medium (CM) secreted by PCa cells overexpressing OPNc (OPNc-CM). The activation of AR signaling was evaluated by measuring the expression levels of AR-responsive genes (ARGs) using quantitative polymerase chain reaction and specific oligonucleotides. The data demonstrated that all nine tested ARGs (Fgf8, TMPRSS2, Greb1, Cdk2, Ndrg1, Cdk1, Pmepa1, Psa and Ar) are significantly upregulated in response to OPNc-CM compared with LNCaP cells cultured in CM secreted by control cells transfected with empty expression vector. The specific involvement of OPNc was demonstrated by depleting OPNc from OPNc-CM using an anti-OPNc neutralizing antibody. In addition, by using a phosphoinositide 3-kinase (PI3K)-specific inhibitor and AR antagonists, such as flutamide and bicalutamide, it was also observed that upregulation of ARGs in response to OPNc-CM involves PI3K signaling and depends on the AR. In conclusion, these data indicated that OPNc is able to activate AR signaling through the PI3K pathway and the AR. These data further corroborate our previous data, revealing the OPNc splice variant to be a key molecule that is able to modulate key signaling pathways involved in PCa progression. PMID:25789054

Downregulation of androgen receptors by NaAsO2 via inhibition of AKT-NF-κB and HSP90 in castration resistant prostate cancer.

PubMed

Kim, Yunlim; Park, Sang Eun; Moon, Jeong-Weon; Kim, Bong-Min; Kim, Ha-Gyeong; Jeong, In Gab; Yoo, Sangjun; Ahn, Jae Beom; You, Dalsan; Pak, Jhang Ho; Kim, Sujong; Hwang, Jung Jin; Kim, Choung-Soo

2017-07-01

Androgen and androgen receptor (AR) play essential roles in the development and maintenance of prostate cancer. The recently identified AR splice variants (AR-Vs) have been considered as a plausible mechanism for the primary resistance against androgen deprivation therapy (ADT) in castration-resistant prostate cancer (CRPC). Sodium meta-arsenite (NaAsO 2 ; KML001; Kominox), a trivalent arsenical, is an orally bioavailable and water soluble, which is currently in phase I/II clinical trials for the treatment of prostate cancer. It has a potent anti-cancer effect on prostate cancer cells and xenografts. The aim of this study was to examine the effect of NaAsO 2 on AR signaling in LNCaP and 22Rv1 CRPC cells. We used hormone-sensitive LNCaP cells, hormone-insensitive 22Rv1 cells, and CRPC patient-derived primary cells. We analyzed anti-cancer effect of NaAsO 2 using real-time quantitative reverse transcription-PCR, Western blotting, immunofluorescence staining and CellTiter Glo® luminescent assay. Statistical evaluation of the results was performed by one-way ANOVA. NaAsO 2 significantly reduced the translocation of AR and AR-Vs to the nucleus as well as their level in LNCaP and 22Rv1 cells. Besides, the level of the prostate-specific antigen (PSA), downstream target gene of AR, was also decreased. This compound was also an effective modulator of AKT-dependent NF-κB activation which regulates AR. NaAsO 2 significantly inhibited phosphorylation of AKT and expression and nuclear translocation of NF-κB. We then investigated the effect of NaAsO 2 on AR stabilization. NaAsO 2 promoted HSP90 acetylation by down-regulating HDAC6, which reduces the stability of AR in prostate cancer cells. Here, we show that NaAsO 2 disrupts AR signaling at multiple levels by affecting AR expression, stability, and degradation in primary tumor cell cultures from prostate cancer patients as well as CRPC cell lines. These results suggest that NaAsO 2 could be a novel therapeutics for prostate cancer. © 2017 Wiley Periodicals, Inc.

Modulation of AKR1C2 by curcumin decreases testosterone production in prostate cancer.

PubMed

Ide, Hisamitsu; Lu, Yan; Noguchi, Takahiro; Muto, Satoru; Okada, Hiroshi; Kawato, Suguru; Horie, Shigeo

2018-04-01

Intratumoral androgen biosynthesis has been recognized as an essential factor of castration-resistant prostate cancer. The present study investigated the effects of curcumin on the inhibition of intracrine androgen synthesis in prostate cancer. Human prostate cancer cell lines, LNCaP and 22Rv1 cells were incubated with or without curcumin after which cell proliferation was measured at 0, 24, 48 and 72 hours, respectively. Prostate tissues from the transgenic adenocarcinoma of the mouse prostate (TRAMP) model were obtained after 1-month oral administration of 200 mg/kg/d curcumin. Testosterone and dihydrotestosterone concentrations in LNCaP prostate cancer cells were determined through LC-MS/MS assay. Curcumin inhibited cell proliferation and induced apoptosis of prostate cancer cells in a dose-dependent manner. Curcumin decreased the expression of steroidogenic acute regulatory proteins, CYP11A1 and HSD3B2 in prostate cancer cell lines, supporting the decrease of testosterone production. After 1-month oral administration of curcumin, Aldo-Keto reductase 1C2 (AKR1C2) expression was elevated. Simultaneously, decreased testosterone levels in the prostate tissues were observed in the TRAMP mice. Meanwhile, curcumin treatments considerably increased the expression of AKR1C2 in prostate cancer cell lines, supporting the decrease of dihydrotestosterone. Taken together, these results suggest that curcumin's natural bioactive compounds could have potent anticancer properties due to suppression of androgen production, and this could have therapeutic effects on prostate cancer. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Adipose Stem Cell-Based Therapeutic Targeting of Residual Androgens in African Americans with Bone-Metastatic Prostate Cancer

DTIC Science & Technology

2015-11-01

points post xenograft . We demonstrated that ADMSCs derived from African American with PC (ADMSCAA) promote LNCaP cell tumor growth in gonad-intact...Task-7: Compare the ability of ADMSCCont and ADMSCSel cells to colocalize to bone tumor xenografts in vivo. 7.1. Inject CaP cells, alone or with...construct expressing GFP (pLV-GFP). Nude mice (n=5) bearing LNCaP xenografts ( 8weeks) were injected with 2 x 105 transduced GFP-expressing ADMSCs and

Stearoyl CoA Desaturase (SCD) Facilitates Proliferation of Prostate Cancer Cells through Enhancement of Androgen Receptor Transactivation

PubMed Central

Kim, Seung-Jin; Choi, Hojung; Park, Sung-Soo; Chang, Chawnshang; Kim, Eungseok

2011-01-01

Stearoyl-CoA desaturase (SCD), the rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids, is highly expressed in prostate cancer although the SCD protein has been known to be rapidly turned over by proteolytic cleavage. The present data demonstrate that SCD can promote proliferation of androgen receptor (AR)-positive LNCaP prostate cancer cells and enhance dihydrotestosterone (DHT)-induced AR transcriptional activity, resulting in increased expression of prostatespecific antigen (PSA) and kallikrein-related peptidase 2 (KLK2). Interestingly, among the previously reported SCDderived peptides produced by proteolytic cleavage of SCD, a peptide spanning amino acids 130-162 of SCD (SCDCoRNR) contained the CoRNR box motif (LFLII) and enhanced AR transcriptional activity. In contrast, a mutant SCD-CoRNR in which Leu136 was replaced by Ala had no effect on AR transcriptional activity. Moreover, SCDCoRNR directly interacted with AR and inhibited RIP140 suppression of AR transactivation. Knockdown of the SCD gene by SCD microRNA suppressed AR transactivation with decreased cell proliferation, suggesting that SCD may regulate the proliferation of LNCaP cells via modulation of AR transcriptional activity. Moreover, ectopic expression of SCD in LNCaP cells facilitated LNCaP tumor formation and growth in nude mice. Together, the data indicate that SCD plays a key role in the regulation of AR transcriptional activity in prostate cancer cells. PMID:21331774

Chemical Suppression of the Reactivated Androgen Signaling Pathway in Androgen-Independent Prostate Cancer

DTIC Science & Technology

2011-07-01

when it is ingested during pregnancy [20,21]. Aside from its role in development, Hh signaling also supports stem cells in adult tissues [22-24]. However...For the mo.~t commonly uti - lized human prostate cancer cell lines (LNCaP and derivatives, DUI45, PC3 or CWR22rvl) grown in culture, Shh, Glil/2 and

Antiandrogens act as selective androgen receptor modulators at the proteome level in prostate cancer cells.

PubMed

Brooke, Greg N; Gamble, Simon C; Hough, Michael A; Begum, Shajna; Dart, D Alwyn; Odontiadis, Michael; Powell, Sue M; Fioretti, Flavia M; Bryan, Rosie A; Waxman, Jonathan; Wait, Robin; Bevan, Charlotte L

2015-05-01

Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic responses dependent upon cellular context. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Antiandrogens Act as Selective Androgen Receptor Modulators at the Proteome Level in Prostate Cancer Cells*

PubMed Central

Brooke, Greg N.; Gamble, Simon C.; Hough, Michael A.; Begum, Shajna; Dart, D. Alwyn; Odontiadis, Michael; Powell, Sue M.; Fioretti, Flavia M.; Bryan, Rosie A.; Waxman, Jonathan; Wait, Robin; Bevan, Charlotte L.

2015-01-01

Current therapies for prostate cancer include antiandrogens, inhibitory ligands of the androgen receptor, which repress androgen-stimulated growth. These include the selective androgen receptor modulators cyproterone acetate and hydroxyflutamide and the complete antagonist bicalutamide. Their activity is partly dictated by the presence of androgen receptor mutations, which are commonly detected in patients who relapse while receiving antiandrogens, i.e. in castrate-resistant prostate cancer. To characterize the early proteomic response to these antiandrogens we used the LNCaP prostate cancer cell line, which harbors the androgen receptor mutation most commonly detected in castrate-resistant tumors (T877A), analyzing alterations in the proteome, and comparing these to the effect of these therapeutics upon androgen receptor activity and cell proliferation. The majority are regulated post-transcriptionally, possibly via nongenomic androgen receptor signaling. Differences detected between the exposure groups demonstrate subtle changes in the biological response to each specific ligand, suggesting a spectrum of agonistic and antagonistic effects dependent on the ligand used. Analysis of the crystal structures of the AR in the presence of cyproterone acetate, hydroxyflutamide, and DHT identified important differences in the orientation of key residues located in the AF-2 and BF-3 protein interaction surfaces. This further implies that although there is commonality in the growth responses between androgens and those antiandrogens that stimulate growth in the presence of a mutation, there may also be influential differences in the growth pathways stimulated by the different ligands. This therefore has implications for prostate cancer treatment because tumors may respond differently dependent upon which mutation is present and which ligand is activating growth, also for the design of selective androgen receptor modulators, which aim to elicit differential proteomic responses dependent upon cellular context. PMID:25693800

Modulation of paracrine signaling by CD9 positive small extracellular vesicles mediates cellular growth of androgen deprived prostate cancer

PubMed Central

Soekmadji, Carolina; Riches, James D.; Russell, Pamela J.; Ruelcke, Jayde E.; McPherson, Stephen; Wang, Chenwei; Hovens, Chris M.; Corcoran, Niall M.; Hill, Michelle M.; Nelson, Colleen C.

2017-01-01

Proliferation and maintenance of both normal and prostate cancer (PCa) cells is highly regulated by steroid hormones, particularly androgens, and the extracellular environment. Herein, we identify the secretion of CD9 positive extracellular vesicles (EV) by LNCaP and DUCaP PCa cells in response to dihydrotestosterone (DHT) and use nano-LC–MS/MS to identify the proteins present in these EV. Subsequent bioinformatic and pathway analyses of the mass spectrometry data identified pathologically relevant pathways that may be altered by EV contents. Western blot and CD9 EV TR-FIA assay confirmed a specific increase in the amount of CD9 positive EV in DHT-treated LNCaP and DUCaP cells and treatment of cells with EV enriched with CD9 after DHT exposure can induce proliferation in androgen-deprived conditions. siRNA knockdown of endogenous CD9 in LNCaPs reduced cellular proliferation and expression of AR and prostate specific antigen (PSA) however knockdown of AR did not alter CD9 expression, also implicating CD9 as an upstream regulator of AR. Moreover CD9 positive EV were also found to be significantly higher in plasma from prostate cancer patients in comparison with benign prostatic hyperplasia patients. We conclude that CD9 positive EV are involved in mediating paracrine signalling and contributing toward prostate cancer progression. PMID:28881726

Designed modulation of sex steroid signaling inhibits telomerase activity and proliferation of human prostate cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verma, Vikas; Sharma, Vikas; Singh, Vishal

The predominant estrogen-receptor (ER)-β signaling in normal prostate is countered by increased ER-α signaling in prostate cancer (CaP), which in association with androgen-receptor (AR) signaling results in pathogenesis of the disease. However CaP treatments mostly target AR signaling which is initially effective but eventually leads to androgen resistance, hence simultaneous targeting of ERs has been proposed. A novel series of molecules were designed with multiple sex-steroid receptor modulating capabilities by coalescing the pharmacophores of known anti-CaP molecules that act via modulation of ER(α/β) and/or AR, viz. 3,3′diindolylmethane (DIM), mifepristone, toremifene, tamoxifen and raloxifene. N,N-diethyl-4-((2-(4-methoxyphenyl)-1H-indol-3-yl)methyl) aniline (DIMA) was identified as themore » most promising structure of this new series. DIMA increased annexin-V labelling, cell-cycle arrest and caspase-3 activity, and decreased expression of AR and prostate specific antigen in LNCaP cells, in vitro. Concurrently, DIMA increased ER-β, p21 and p27 protein levels in LNCaP cells and exhibited ∼ 5 times more selective binding for ER-β than ER-α, in comparison to raloxifene. DIMA exhibited a dose-dependent ER-β agonism and ER-α antagonism in classical gene reporter assay and decreased hTERT (catalytic subunit of telomerase) transcript levels in LNCaP at 3.0 μM (P < 0.05). DIMA also dose-dependently decreased telomerase enzyme activity in prostate cancer cells. It is thus concluded that DIMA acts as a multi-steroid receptor modulator and effectively inhibits proliferation of prostate cancer cells through ER-β mediated telomerase inhibition, by countering actions of ER-α and AR. Its unique molecular design can serve as a lead structure for generation of potent agents against endocrine malignancies like the CaP.« less

Expression and potential role of the peptide orexin-A in prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valiante, Salvatore; Liguori, Giovanna; Tafuri, Simona

The peptides orexin-A and orexin-B and their G protein-coupled OX1 and OX2 receptors are involved in multiple physiological processes in the central nervous system and peripheral organs. Altered expression or signaling dysregulation of orexins and their receptors have been associated with a wide range of human diseases including narcolepsy, obesity, drug addiction, and cancer. Although orexin-A, its precursor molecule prepro-orexin and OX1 receptor have been detected in the human normal and hyperplastic prostate tissues, their expression and function in the prostate cancer (PCa) remains to be addressed. Here, we demonstrate for the first time the immunohistochemical localization of orexin-A inmore » human PCa specimens, and the expression of prepro-orexin and OX1 receptor at both protein and mRNA levels in these tissues. Orexin-A administration to the human androgen-dependent prostate carcinoma cells LNCaP up-regulates OX1 receptor expression resulting in a decrease of cell survival. Noteworthy, nanomolar concentrations of the peptide counteract the testosterone-induced nuclear translocation of the androgen receptor in the cells: the orexin-A action is prevented by the addition of the OX1 receptor antagonist SB-408124 to the test system. These findings indicate that orexin-A/OX1 receptor interaction interferes with the activity of the androgen receptor which regulates PCa onset and progression, thus suggesting that orexin-A and its receptor might represent novel therapeutic targets to challenge this aggressive cancer. - Highlights: • Orexin-A and OX1 receptor are present in human cancer prostate tissues. • Orexin-A up-regulates OX1 receptor expression in LNCaP cells. • Orexin-A inhibits testosterone-induced nuclear translocation of androgen receptor.« less

Neutral endopeptidase promotes phorbol ester-induced apoptosis in prostate cancer cells by inhibiting neuropeptide-induced protein kinase C delta degradation.

PubMed

Sumitomo, M; Shen, R; Goldberg, J S; Dai, J; Navarro, D; Nanus, D M

2000-12-01

Phorbol esters induce apoptosis in androgen-sensitive LNCaP cells, which express neutral endopeptidase (NEP), but not in androgen-independent prostate cancer (PC) cells, which lack NEP expression. We investigated the role of NEP in PC cell susceptibility to 12-O-tetradecanoylphorbol-13-acetate (TPA). Western analysis showed that expression of NEP and protein kinase Cdelta (PKCdelta) correlated with PC cell sensitivity to TPA-induced growth arrest and apoptosis in LNCaP cells and in TSU-Prl cells expressing an inducible wild-type NEP protein. Inhibition of NEP enzyme activity using the specific NEP inhibitor CGS24592, or inhibition of PKCdelta using Rottlerin at concentrations that inhibit PKCdelta but not PKCalpha, significantly inhibited TPA-induced growth inhibition and cell death. Furthermore, pulse-chase experiments showed PKCdelta is stabilized in LNCaP cells and in TSU-Pr1 cells overexpressing wild-type NEP compared with PC cells lacking NEP expression. This results from NEP inactivation of its neuropeptide substrates (bombesin and endothelin-1), which in the absence of NEP stimulate cSrc kinase activity and induce rapid degradation of PKCdelta protein. These results indicate that expression of enzymatically active NEP by PC cells is necessary for TPA-induced apoptosis, and that NEP inhibits neuropeptide-induced, cSrc-mediated PKCdelta degradation.

A novel class of pyranocoumarin anti-androgen receptor signaling compounds.

PubMed

Guo, Junming; Jiang, Cheng; Wang, Zhe; Lee, Hyo-Jeong; Hu, Hongbo; Malewicz, Barbara; Lee, Hyo-Jung; Lee, Jae-Ho; Baek, Nam-In; Jeong, Jin-Hyun; Kim, Dae-Keun; Kang, Kyung-Sun; Kim, Sung-Hoon; Lu, Junxuan

2007-03-01

Androgen and the androgen receptor (AR)-mediated signaling are crucial for prostate cancer development. Novel agents that can inhibit AR signaling in ligand-dependent and ligand-independent manners are desirable for the chemoprevention of prostate carcinogenesis and for the treatment of advanced prostate cancer. We have shown recently that the pyranocoumarin compound decursin from the herb Angelica gigas possesses potent anti-AR activities distinct from the anti-androgen bicalutamide. Here, we compared the anti-AR activities and the cell cycle arrest and apoptotic effects of decursin and two natural analogues in the androgen-dependent LNCaP human prostate cancer cell culture model to identify structure-activity relationships and mechanisms. Decursin and its isomer decursinol angelate decreased prostate-specific antigen expression with IC(50) of approximately 1 mumol/L. Both inhibited the androgen-stimulated AR nuclear translocation and transactivation, decreased AR protein abundance through proteasomal degradation, and induced G(0/1) arrest and morphologic differentiation. They also induced caspase-mediated apoptosis and reactive oxygen species at higher concentrations. Furthermore, they lacked the agonist activity of bicalutamide in the absence of androgen and were more potent than bicalutamide for suppressing androgen-stimulated cell growth. Decursinol, which does not contain a side chain, lacked the reactive oxygen species induction and apoptotic activities and exerted paradoxically an inhibitory and a stimulatory effect on AR signaling and cell growth. In conclusion, decursin and decursinol angelate are members of a novel class of nonsteroidal compounds that exert a long-lasting inhibition of both ligand-dependent and ligand-independent AR signaling. The side chain is critical for sustaining the anti-AR activities and the growth arrest and apoptotic effects.

Dietary flavonoid tangeretin induces reprogramming of epithelial to mesenchymal transition in prostate cancer cells by targeting the PI3K/Akt/mTOR signaling pathway.

PubMed

Zhu, Wen-Bin; Xiao, Ning; Liu, Xing-Jie

2018-01-01

Tangeretin, a natural polymethoxyflavone present in the peel of citrus fruits is known to exhibit anticancer properties against a variety of carcinomas. Previous experimental evidence suggests that lifestyle and dietary habits affect the risk of prostate cancer to a certain extent. As the effect of tangeretin on prostate cancer is unexplored, the present study investigated the effect of tangeretin on androgen-insensitive PC-3 cells and androgen-sensitive LNCaP cells. Tangeretin reduced the cell viability of PC-3 cells in a dose- and time-dependent manner, with the half-maximal inhibitory concentration (IC 50 ) observed at 75 µM dose following 72 h of incubation, while in LNCaP cells, the IC 50 was identified to be ~65 µM. Expression levels of the mesenchymal proteins including vimentin, cluster of differentiation 44 and Neural cadherin in PC-3 cells were reduced by tangeretin treatment, whereas those of the epithelial proteins, including Epithelial cadherin and cytokeratin-19 were upregulated. Treatment of PC-3 cells also resulted in the downregulation of the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway. Therefore, it may be concluded that tangeretin induces reprogramming of epithelial-mesenchymal transition in PC-3 cells by targeting the PI3K/Akt/mTOR signaling pathway.

Arctigenin in combination with quercetin synergistically enhances the antiproliferative effect in prostate cancer cells.

PubMed

Wang, Piwen; Phan, Tien; Gordon, David; Chung, Seyung; Henning, Susanne M; Vadgama, Jaydutt V

2015-02-01

We investigated whether a combination of two promising chemopreventive agents arctigenin (Arc) and quercetin (Q) increases the anticarcinogenic potency at lower concentrations than necessary when used individually in prostate cancer. Androgen-dependent LAPC-4 and LNCaP prostate cancer cells were treated with low doses of Arc and Q alone or in combination for 48 h. The antiproliferative activity of Arc was 10- to 20-fold stronger than Q in both cell lines. Their combination synergistically enhanced the antiproliferative effect, with a stronger effect in androgen receptor (AR) wild-type LAPC-4 cells than in AR mutated LNCaP cells. Arc demonstrated a strong ability to inhibit AR protein expression in LAPC-4 cells. The combination treatment significantly inhibited both AR and PI3K/Akt pathways compared to control. A protein array analysis revealed that the mixture targets multiple pathways particularly in LAPC-4 cells including Stat3 pathway. The mixture significantly inhibited the expression of several oncogenic microRNAs including miR-21, miR-19b, and miR-148a compared to control. The mixture also enhanced the inhibition of cell migration in both cell lines compared to individual compounds tested. The combination of Arc and Q that target similar pathways, at low physiological doses, provides a novel regimen with enhanced chemoprevention in prostate cancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Arctigenin in combination with quercetin synergistically enhances the anti-proliferative effect in prostate cancer cells

PubMed Central

Wang, Piwen; Phan, Tien; Gordon, David; Chung, Seyung; Henning, Susanne M.; Vadgama, Jaydutt V.

2014-01-01

Scope We investigated whether a combination of two promising chemopreventive agents arctigenin and quercetin increases the anti-carcinogenic potency at lower concentrations than necessary when used individually in prostate cancer. Methods and results Androgen-dependent LAPC-4 and LNCaP prostate cancer cells were treated with low doses of arctigenin and quercetin alone or in combination for 48h. The anti-proliferative activity of arctigenin was 10-20 fold stronger than quercetin in both cell lines. Their combination synergistically enhanced the anti-proliferative effect, with a stronger effect in androgen receptor (AR) wild-type LAPC-4 cells than in AR mutated LNCaP cells. Arctigenin demonstrated a strong ability to inhibit AR protein expression in LAPC-4 cells. The combination treatment significantly inhibited both AR and PI3K/Akt pathways compared to control. A protein array analysis revealed that the mixture targets multiple pathways particularly in LAPC-4 cells including Stat3 pathway. The mixture significantly inhibited the expression of several oncogenic microRNAs including miR-21, miR-19b, and miR-148a compared to control. The mixture also enhanced the inhibition of cell migration in both cell lines compared to individual compounds tested. Conclusion The combination of arctigenin and quercetin, that target similar pathways, at low physiological doses, provides a novel regimen with enhanced chemoprevention in prostate cancer. PMID:25380086

Relationship between serum response factor and androgen receptor in prostate cancer.

PubMed

Prencipe, Maria; O'Neill, Amanda; O'Hurley, Gillian; Nguyen, Lan K; Fabre, Aurelie; Bjartell, Anders; Gallagher, William M; Morrissey, Colm; Kay, Elaine W; Watson, R William

2015-11-01

Serum response factor (SRF) is an important transcription factor in castrate-resistant prostate cancer (CRPC). Since CRPC is associated with androgen receptor (AR) hypersensitivity, we investigated the relationship between SRF and AR. Transcriptional activity was assessed by luciferase assay. Cell proliferation was measured by MTT and flow cytometry. Protein expression in patients was assessed by immunohistochemistry. To investigate AR involvement in SRF response to androgen, AR expression was down-regulated using siRNA. This resulted in the abrogation of SRF induction post-DHT. Moreover, DHT stimulation failed to induce SRF transcriptional activity in AR-negative PC346 DCC cells, which was only restored following AR over-expression. Next, SRF expression was down-regulated by siRNA, resulting in AR increased transcriptional activity in castrate-resistant LNCaP Abl cells but not in the parental LNCaP. This negative feedback loop in the resistant cells was confirmed by immunohistochemistry which showed a negative correlation between AR and SRF expression in CRPC bone metastases and a positive correlation in androgen-naïve prostatectomies. Cell proliferation was next assessed following SRF inhibition, demonstrating that SRF inhibition is more effective than AR inhibition in castrate-resistant cells. Our data support SRF as a promising therapeutic target in combination with current treatments. © 2015 Wiley Periodicals, Inc.

Expression of membrane-type 1 matrix metalloproteinase (MT1-MMP) on prostate cancer cell lines.

PubMed

Nagakawa, O; Murakami, K; Yamaura, T; Fujiuchi, Y; Murata, J; Fuse, H; Saiki, I

2000-07-31

Membrane-type metalloproteinase-1 (MT1-MMP) is a transmembrane metalloproteinase, which activates proMMP-2 and expressed on the cell surface in many invasive cancer cells. We investigated the expression of MT1-MMP in prostate cancer cell lines. MT1-MMP protein and mRNA were expressed in PC-3, DU-145 and TSU-pr1 cells (androgen-independent prostate cancer cell lines), but in LNCaP cells (androgen-dependent prostate cancer cell line). MT1-MMP protein was negative and mRNA was low to detect by RT-PCR. Cell lysate of PC-3 cleaved proMMP-2 to the active form. In addition, both hepatocyte growth factor (HGF) and gastrin-releasing peptide (GRP) increased Matrigel invasion and induced the expression of MT1-MMP protein in DU-145 prostate cancer cells. These results suggest that MT1-MMP is indeed the tumor-specific activator of proMMP-2 in androgen-independent prostate cancer cells and plays an important role in the invasive properties of prostate cancer cells.

Banana peel extract suppressed prostate gland enlargement in testosterone-treated mice.

PubMed

Akamine, Kiichiro; Koyama, Tomoyuki; Yazawa, Kazunaga

2009-09-01

A methanol extract of banana peel (BPEx, 200 mg/kg, p.o.) significantly suppressed the regrowth of ventral prostates and seminal vesicles induced by testosterone in castrated mice. Further studies in the androgen-responsive LNCaP human prostate cancer cell line showed that BPEx inhibited dose-dependently testosterone-induced cell growth, while the inhibitory activities of BPEx did not appear against dehydrotestosterone-induced cell growth. These results indicate that methanol extract of banana peel can inhibit 5alpha-reductase and might be useful in the treatment of benign prostate hyperplasia.

TRIM25 enhances cell growth and cell survival by modulating p53 signals via interaction with G3BP2 in prostate cancer.

PubMed

Takayama, Ken-Ichi; Suzuki, Takashi; Tanaka, Tomoaki; Fujimura, Tetsuya; Takahashi, Satoru; Urano, Tomohiko; Ikeda, Kazuhiro; Inoue, Satoshi

2018-04-01

Prostate cancer growth is promoted by the gene regulatory action of androgen receptor (AR) and its downstream signals. The aberrant dysfunction of tumor suppressor p53 has an important role in the prognosis of cancer. We previously found that androgen treatments translocate p53 to the cytoplasm. The mechanism of this translocation depends on sumoylation of p53 by complex of SUMO E3 ligase RanBP2 with androgen-induced GTPase-activating protein-binding protein 2 (G3BP2). Here, we identified tripartite motif-containing protein 25 (TRIM25)/estrogen-responsive finger protein (Efp) as a novel interacting partner of G3BP2 protein complex. Then, we demonstrated that TRIM25 knockdown resulted in p53 downstream activation for cell cycle inhibition and apoptosis induction in LNCaP and 22Rv1 cells. In contrast, overexpression of TRIM25 promoted prostate cancer cell proliferation and inhibited apoptosis by docetaxel treatment in LNCaP cells. We observed that p53 activity was reduced by mechanism of G3BP2-mediated nuclear export in TRIM25-overexpressing prostate cancer cells. We also found TRIM25 is important for G3BP2/RanBP2-mediated p53 modification. Clinically, we newly demonstrated that TRIM25 is a prognostic factor for prostate cancer patients. Expression of TRIM25 is significantly associated with cytoplasmic p53 expression and G3BP2. Moreover, TRIM25 knockdown results in reduced tumor growth and increased p53 activity in the mouse xenograft model of prostate cancer. Thus, our findings show that overexpression of TRIM25 promoted prostate cancer cell proliferation and cell survival by modulating p53 nuclear export mechanism with G3BP2 interaction.

Baicalein suppresses the androgen receptor (AR)-mediated prostate cancer progression via inhibiting the AR N-C dimerization and AR-coactivators interaction.

PubMed

Xu, Defeng; Chen, Qiulu; Liu, Yalin; Wen, Xingqiao

2017-12-01

Androgen receptor (AR) plays a critical role in prostate cancer (PCa) development and progression. Androgen deprivation therapy with antiandrogens to reduce androgen biosynthesis or prevent androgens from binding to AR are widely used to suppress AR-mediated PCa growth. However, most of ADT may eventually fail with development of the castration resistance after 12-24 months. Here we found that a natural product baicalein can effectively suppress the PCa progression via targeting the androgen-induced AR transactivation with little effect to AR protein expression. PCa cells including LNCaP, CWR22Rv1, C4-2, PC-3, and DU145, were treated with baicalein and luciferase assay was used to evaluate their effect on the AR transactivation. Cell growth and IC 50 were determined by MTT assay after 48 hrs treatment. RT-PCR was used to evaluate the mRNA levels of AR target genes including PSA, TMPRSS2, and TMEPA1. Western blot was used to determine AR and PSA protein expression. The natural product of baicalein can selectively inhibit AR transactivation with little effect on the other nuclear receptors, including ERα, and GR. At a low concentration, 2.5 μM of baicalein effectively suppresses the growth of AR-positive PCa cells, and has little effect on AR-negative PCa cells. Mechanism dissection suggest that baicalein can suppress AR target genes (PSA, TMPRSS2, and TMEPA1) expression in both androgen responsive LNCaP cells and castration resistant CWR22Rv1 cells, that may involve the inhibiting the AR N/C dimerization and AR-coactivators interaction. Baicalein may be developed as an effective anti-AR therapy via its ability to inhibit AR transactivation and AR-mediated PCa cell growth.

Proliferation of prostate cancer cells and activity of neutral endopeptidase is regulated by bombesin and IL-1beta with IL-1beta acting as a modulator of cellular differentiation.

PubMed

Albrecht, Martin; Doroszewicz, Jolanta; Gillen, Sonja; Gomes, Iara; Wilhelm, Beate; Stief, Thomas; Aumüller, Gerhard

2004-01-01

Neutral endopeptidase (NEP) is a cell-surface bound enzyme that cleaves and inactivates neuropeptides such as bombesin and substance P and is involved in the transition from hormonally regulated androgen-dependent prostate cancer (PC) to androgen-independent PC. Neuropeptides are implicated in growth regulation of different cell types and function as transmitters between the neuroendocrine and the immune system. NEP-expression, enzymatic activity of the membrane bound protein, cell proliferation, procalcitonin (PCT) production, and secretion as well as changes in cell morphology of prostatic cells were evaluated after treatment with the immunomodulatory cytokine interleukin-1beta (IL-1beta), neuropeptides (bombesin, substance P), and neuropeptide-conditioned media derived from a human neuroendocrine cell line. Incubation of LNCaP tumor cells with IL-1beta resulted in a diminished proliferative activity, induction of neurite-like outgrowth which was accompanied by the formation of tubular-type mitochondria typical for neuronal/neuroendocrine cells, and an increased production and secretion of PCT. Conversely, proliferation of prostatic stromal cells was enhanced by the cytokine coming along with an increased number of Golgi-apparatuses and ER-cisternae. Bombesin had an antimitotic effect on LNCaP, but not on stromal cells. Substance P did not influence the growth of any of the cell types investigated, whereas neuropeptide-conditioned media exerted a slightly mitogenic effect on both cell types. The activity of LNCaP cell-surface bound NEP was enhanced by bombesin, but was diminished by substance P and neuropeptide-conditioned media. Proliferation and activity of neuropeptide degrading NEP is regulated differently by immunomodulatory substances in PC cells and cells derived from the prostatic stroma with IL-1beta being a potent modulator of cellular differentiation and a potential target for anticancer drug design in PC cells. Copyright 2003 Wiley-Liss, Inc.

p,p'-Dichlorodiphenyltrichloroethane (p,p'-DDT) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) repress prostate specific antigen levels in human prostate cancer cell lines.

PubMed

Wong, Lilian I L; Labrecque, Mark P; Ibuki, Naokazu; Cox, Michael E; Elliott, John E; Beischlag, Timothy V

2015-03-25

Despite stringent restrictions on their use by many countries since the 1970s, the endocrine disrupting chemicals, DDT and DDE are still ubiquitous in the environment. However, little attention has been directed to p,p'-DDT and the anti-androgen, p,p'-DDE on androgen receptor (AR) target gene transcription in human cells. Inhibitors of androgenic activity may have a deleterious clinical outcome in prostate cancer screens and progression, therefore we determined whether environmentally relevant concentrations of p,p'-DDT and p,p'-DDE negatively impact AR-regulated expression of prostate-specific antigen (PSA), and other AR target genes in human LNCaP and VCaP prostate cancer cells. Quantitative real-time PCR and immuno-blotting techniques were used to measure intracellular PSA, PSMA and AR mRNA and protein levels. We have shown for the first time that p,p'-DDT and p,p'-DDE repressed R1881-inducible PSA mRNA and protein levels in a dose-dependent manner. Additionally, we used the fully automated COBAS PSA detection system to determine that extracellular PSA levels were also significantly repressed. These chemicals achieve this by blocking the recruitment of AR to the PSA promoter region at 10 μM, as demonstrated by the chromatin immunoprecipitation (ChIP) in LNCaP cells. Both p,p'-DDT and p,p'-DDE repressed R1881-inducible AR protein accumulation at 10 μM. Thus, we conclude that men who have been exposed to either DDT or DDE may produce a false-negative PSA test when screening for prostate cancer, resulting in an inaccurate clinical diagnosis. More importantly, prolonged exposure to these anti-androgens may mimic androgen ablation therapy in individuals with prostate cancer, thus exacerbating the condition by inadvertently forcing adaptation to this stress early in the disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Finasteride Inhibits Human Prostate Cancer Cell Invasion through MMP2 and MMP9 Downregulation

PubMed Central

Moroz, Andrei; Delella, Flávia K.; Almeida, Rodrigo; Lacorte, Lívia Maria; Fávaro, Wágner José; Deffune, Elenice; Felisbino, Sérgio L.

2013-01-01

Introduction The use of the 5-alpha reductase inhibitors (5-ARIs) finasteride and dutasteride for prostate cancer prevention is still under debate. The FDA recently concluded that the increased prevalence of high-grade tumors among 5-ARI-treated patients must not be neglected, and they decided to disallow the use of 5-ARIs for prostate cancer prevention. This study was conducted to verify the effects of finasteride on prostate cell migration and invasion and the related enzymes/proteins in normal human and tumoral prostatic cell lines. Materials and Methods RWPE-1, LNCaP, PC3 and DU145 cells were cultivated to 60% confluence and exposed for different periods to either 10 µM or 50 µM finasteride that was diluted in culture medium. The conditioned media were collected and concentrated, and MMP2 and MMP9 activities and TIMP-1 and TIMP-2 protein expression were determined. Cell viability, migration and invasion were analyzed, and the remaining cell extracts were submitted to androgen receptor (AR) detection by western blotting techniques. Experiments were carried out in triplicate. Results Cell viability was not significantly affected by finasteride exposure. Finasteride significantly downregulated MMP2 and MMP9 activities in RWPE-1 and PC3 cells and MMP2 in DU145 cells. TIMP-2 expression in RWPE-1 cells was upregulated after exposure. The cell invasion of all four tested cell lines was inhibited by exposure to 50 µM of finasteride, and migration inhibition only occurred for RWPE-1 and LNCaP cells. AR was expressed by LNCaP, RWPE-1 and PC3 cells. Conclusions Although the debate on the higher incidence of high-grade prostate cancer among 5-ARI-treated patients remains, our findings indicate that finasteride may attenuate tumor aggressiveness and invasion, which could vary depending on the androgen responsiveness of a patient’s prostate cells. PMID:24386413

The prohibitin-repressive interaction with E2F1 is rapidly inhibited by androgen signalling in prostate cancer cells

PubMed Central

Koushyar, S; Economides, G; Zaat, S; Jiang, W; Bevan, C L; Dart, D A

2017-01-01

Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR. Additionally, their cellular locations and chromatin interactions are in dynamic opposition. We investigated the mechanisms of cell cycle inhibition by PHB and how this is modulated by AR in prostate cancer. Using a prostate cancer cell line overexpressing PHB, we analysed the gene expression changes associated with PHB-mediated cell cycle arrest. Over 1000 gene expression changes were found to be significant and gene ontology analysis confirmed PHB-mediated repression of genes essential for DNA replication and synthesis, for example, MCMs and TK1, via an E2F1 regulated pathway—agreeing with its G1/S cell cycle arrest activity. PHB is known to inhibit E2F1-mediated transcription, and the PHB:E2F1 interaction was seen in LNCaP nuclear extracts, which was then reduced by androgen treatment. Upon two-dimensional western blot analysis, the PHB protein itself showed androgen-mediated charge differentiation (only in AR-positive cells), indicating a potential dephosphorylation event. Kinexus phosphoprotein array analysis indicated that Src kinase was the main interacting intracellular signalling hub in androgen-treated LNCaP cells, and that Src inhibition could reduce this AR-mediated charge differentiation. PHB charge change may be associated with rapid dissociation from chromatin and E2F1, allowing the cell cycle to proceed. The AR and androgens may deactivate the repressive functions of PHB upon E2F1 leading to cell cycle progression, and indicates a role for AR in DNA replication licensing. PMID:28504694

Shifted Golgi targeting of glycosyltransferases and α-mannosidase IA from giantin to GM130-GRASP65 results in formation of high mannose N-glycans in aggressive prostate cancer cells.

PubMed

Bhat, Ganapati; Hothpet, Vishwanath-Reddy; Lin, Ming-Fong; Cheng, Pi-Wan

2017-11-01

There is a pressing need for biomarkers that can distinguish indolent from aggressive prostate cancer to prevent over-treatment of patients with indolent tumor. Golgi targeting of glycosyltransferases was characterized by confocal microscopy after knockdown of GM130, giantin, or both. N-glycans on a trans-Golgi enzyme β4galactosyltransferase-1 isolated by immunoprecipitation from androgen-sensitive and independent prostate cancer cells were determined by matrix-assisted laser desorption-time of flight-mass spectrometry. In situ proximity ligation assay was employed to determine co-localization of (a) α-mannosidase IA, an enzyme required for processing Man 8 GlcNAc 2 down to Man 5 GlcNAc 2 to enable synthesis of complex-type N-glycans, with giantin, GM130, and GRASP65, and (b) trans-Golgi glycosyltransferases with high mannose N-glycans terminated with α3-mannose. Defective giantin in androgen-independent prostate cancer cells results in a shift of Golgi targeting of glycosyltransferases and α-mannosidase IA from giantin to GM130-GRASP65. Consequently, trans-Golgi enzymes and cell surface glycoproteins acquire high mannose N-glycans, which are absent in cells with functional giantin. In situ proximity ligation assays of co-localization of α-mannosidase IA with GM130 and GRASP65, and trans-Golgi glycosyltransferases with high mannose N-glycans are negative in androgen-sensitive LNCaP C-33 cells but positive in androgen-independent LNCaP C-81 and DU145 cells, and LNCaP C-33 cells devoid of giantin. In situ proximity ligation assays of Golgi localization of α-mannosidase IA at giantin versus GM130-GRASP65 site, and absence or presence of N-glycans terminated with α3-mannose on trans-Golgi glycosyltransferases may be useful for distinguishing indolent from aggressive prostate cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

γ-Oryzanol reduces caveolin-1 and PCGEM1 expression, markers of aggressiveness in prostate cancer cell lines.

PubMed

Hirsch, Gabriela E; Parisi, Mariana M; Martins, Leo A M; Andrade, Claudia M B; Barbé-Tuana, Florencia M; Guma, Fátima T C R

2015-06-01

Prostate cancer is a leading cause of death among men due to the limited number of treatment strategies available for advanced disease. γ-oryzanol is a component of rice bran, rich in phytosterols, known for its antioxidant, anti-carcinogenic and endocrinological effects. It is known that γ-oryzanol may affect prostate cancer cells through the down regulation of the antioxidant genes and that phytosterols have anti-proliferative and apoptotic effects. There are evidences showing that some of the components of γ-oryzanol can modulate genes involved in the development and progression of prostate cancer, as caveolin-1 (Cav-1) and prostate specific androgen-regulated gene (PCGEM1). To determine the effects of γ-oryzanol on prostate cancer cell survival we evaluated the cell viability and biomass by MTT and sulforhodamine B assays, respectively. Cell death, cell cycle and pERK1/2 activity were assessed by flow cytometry. The changes in gene expression involved in the survival and progression of prostate cancer cav-1 and PCGEM1 genes were evaluated by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) and cav-1 protein by immunofluorescence followed by confocal microscopy analysis. We found that γ-oryzanol decreases cell viability and culture biomass by apoptosis and/or necrosis death in androgen unresponsive (PC3 and DU145) and responsive (LNCaP) cell lines, and signals through pERK1/2 in LNCaP and DU145 cells. γ-oryzanol also appears to block cell cycle progression at the G2/M in PC3 and LNCaP cells and at G0/G1 in DU145 cells. These effects were accompanied by a down regulation in the expression of the cav-1 in both androgen unresponsive cell lines and PCGEM1 gene in DU145 and LNCaP cells. In summary, we used biochemical and genetics approaches to demonstrate that γ-oryzanol show a promising adjuvant role in the treatment of prostate cancer. © 2015 Wiley Periodicals, Inc.

CD147 modulates androgen receptor activity through the Akt/Gsk-3β/β-catenin/AR pathway in prostate cancer cells.

PubMed

Fang, Fang; Qin, Yingxin; Hao, Feng; Li, Qiang; Zhang, Wei; Zhao, Chen; Chen, Shuang; Zhao, Liangzhong; Wang, Liguo; Cai, Jianhui

2016-08-01

The androgen signaling pathway serves an important role in the development of prostate cancer. β-Catenin is an androgen receptor (AR) cofactor and augments AR signaling. Glycogen synthase kinase-3β (GSK-3β), a target of phosphorylated serine/threonine protein kinase B (p-Akt), regulates β-catenin stability. In addition, β-catenin, a coregulator of AR, physically interacts with AR and enhances AR-mediated target gene transcription. The multifunctional glycoprotein cluster of differentiation (CD) 147 is highly expressed on the cell surface of the majority of cancer cells, and it promotes tumor invasion, metastasis and growth. In the present study, the molecular effects of CD147 on the Akt/GSK-3β/β-catenin/AR signaling network were investigated in LNCaP cells. Using short hairpin-mediated RNA knockdown of CD147 in LNCaP cells, it was demonstrated that downregulation of CD147 resulted in inhibitory phosphorylation of GSK-3β, and then promoted degeneration of β-catenin and reduced nuclear accumulation of β-catenin. In addition, immunoprecipitation studies demonstrated that CD147 downregulation decreased the formation of a complex between β-catenin and AR. It was shown that CD147 knockdown suppressed the expression of the AR target gene prostate-specific antigen and the growth of AR-positive LNCaP cells. Furthermore, inhibition of PI3K/Akt with LY294002 augmented CD147-mediated function. The present study indicates that the PI3K/Akt pathway may facilitate CD147-mediated activation of the AR pathway.

PCA3 Silencing Sensitizes Prostate Cancer Cells to Enzalutamide-mediated Androgen Receptor Blockade.

PubMed

Özgür, Emre; Celik, Ayca Iribas; Darendeliler, Emin; Gezer, Ugur

2017-07-01

Prostate cancer (PCa) is an androgen-dependent disease. Novel anti-androgens (i.e. enzalutamide) have recently been developed for the treatment of patients with metastatic castration-resistant prostate cancer (CRPC). Evidence is accumulating that prostate cancer antigen 3 (PCA3) is involved in androgen receptor (AR) signaling. Here, in combination with enzalutamide-mediated AR blockade, we investigated the effect of PCA3 targeting on the viability of PCa cells. In hormone-sensitive LNCaP cells, AR-overexpressing LNCaP-AR + cells and VCaP cells (representing CRPC), PCA3 was silenced using siRNA oligonucleotides. Gene expression and cell viability was assessed in PCA3-silenced and/or AR-blocked cells. PCA3 targeting reduced the expression of AR-related genes (i.e. prostate-specific antigen (PSA) and prostate-specific transcript 1 (non-protein coding) (PCGEM1)) and potentiated the effect of enzalutamide. Proliferation of PCa cells was suppressed upon PCA3 silencing with a greater effect in LNCaP-AR + cells. Furthermore, PCA3 silencing sensitized PCa cells to enzalutamide-induced loss of cell growth. PCA3, as a therapeutic target in PCa, might be used to potentiate AR antagonists. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Inhibition of telomerase potentiates enzalutamide efficiency of androgen-sensitive human prostate cancer cells.

PubMed

Gecgel, Karaca Kaan; Muduroglu, Mustafa; Erdogan, Suat

2017-01-01

Androgen deprivation therapy (ADT) is one of the main strategies to treat prostate cancer (PCa) at various stages of its development. Androgen receptor (AR) antagonists such as enzalutamide are mainstay treatments for castration-sensitive prostate cancer. Though, a majority of patients initially respond to ADT, most will eventually progress to castrate-resistant, due to the development of different mutations on the AR. PCa cells express high telomerase activity, and there is a correlation between the total activity of telomerase and the Gleason score. Therefore, we hypothesized that the combination of enzalutamide plus a telomerase inhibitor could be more effective than enzalutamide alone in decreasing cell survival. In this study MTT test, RT-qPCR and imagebased cytometry were used to investigate cell viability, apoptosis and cell cycle progression of androgen-responsive human prostate cancer LNCaP cells. The cells were treated with 5 μM enzalutamide and 40 μM telomerase inhibitor BIBR 1532, or with their combinations for 72 hrs. Enzalutamide and BIBR 1532 alone inhibited cell proliferation in a dose-dependent manner. The combinations of the two agents could synergistically induce apoptotic and necrotic cell death. Either inhibition of telomerase by BIBR 1532 or AR blockages by enzalutamide decreased prostate-specific antigen (PSA) and the catalytic component of telomerase, hTERT, expression. These results suggest that telomerase inhibition therapy may contribute to the efficacy of enzalutamide in the androgen-sensitive PCa model.

Analysis of the MDM2 antagonist nutlin-3 in human prostate cancer cells.

PubMed

Logan, Ian R; McNeill, Hesta V; Cook, Susan; Lu, Xiaohong; Lunec, John; Robson, Craig N

2007-06-01

Small molecule MDM2 antagonists including nutlin-3 have been shown to be effective against a range of cancer cell types and nutlin-3 can inhibit growth of LNCaP xenografts. We compared the efficacy of nutlin-3 in three prostate cancer cell types and provide an insight into the mechanism of nutlin-3. Nutlin-3 efficacy was measured using proliferation assays, cell cycle analysis, apoptosis assays, quantitative RT-PCR, and immunoblotting. Chromatin immunoprecipitation (ChIP) assays were also performed. Nutlin-3 can specifically inhibit proliferation of LNCaP cells through cell cycle arrest and apoptosis. This coincides with increased levels of the p53-responsive transcripts p21, PUMA, gadd45, and Mdm2 and recruitment of p53 to chromatin. Nutlin-3 also reduces androgen receptor levels, resulting in altered receptor recruitment to chromatin. Our study demonstrates that small molecule MDM2 antagonists might be useful in the treatment of human prostate cancers that retain functional p53 and androgen receptor signaling. Copyright 2007 Wiley-Liss, Inc.

A Novel Dietary Flavonoid Fisetin Inhibits Androgen Receptor Signaling and Tumor Growth in Athymic Nude Mice

PubMed Central

Khan, Naghma; Asim, Mohammad; Afaq, Farrukh; Zaid, Mohammad Abu; Mukhtar, Hasan

2010-01-01

Androgen receptor (AR)–mediated signaling plays an important role in the development and progression of prostate cancer (PCa). Hormonal therapies, mainly with combinations of antiandrogens and androgen deprivation, are the mainstay treatment for advanced disease. However, emergence of androgen resistance largely due to inefficient antihormone action limits their therapeutic usefulness. Here, we report that fisetin, a novel dietary flavonoid, acts as a novel AR ligand by competing with the high-affinity androgen to interact with the ligand binding domain of AR. We show that this physical interaction results in substantial decrease in AR stability and decrease in amino-terminal/carboxyl-terminal (N-C) interaction of AR. This results in blunting of AR-mediated transactivation of target genes including prostate-specific antigen (PSA). In addition, treatment of LNCaP cells with fisetin decreased AR protein levels, in part, by decreasing its promoter activity and by accelerating its degradation. Fisetin also synergized with Casodex in inducing apoptosis in LNCaP cells. Treatment with fisetin in athymic nude mice implanted with AR-positive CWR22Rυ1 human PCa cells resulted in inhibition of tumor growth and reduction in serum PSA levels. These data identify fisetin as an inhibitor of AR signaling axis and suggest that it could be a useful chemopreventive and chemotherapeutic agent to delay progression of PCa. PMID:18922931

Natura-alpha targets forkhead box m1 and inhibits androgen-dependent and -independent prostate cancer growth and invasion.

PubMed

Li, Yirong; Ligr, Martin; McCarron, James P; Daniels, Garrett; Zhang, David; Zhao, Xin; Ye, Fei; Wang, Jinhua; Liu, Xiaomei; Osman, Iman; Mencher, Simon K; Lepor, Hebert; Wang, Long G; Ferrari, Anna; Lee, Peng

2011-07-01

The development of new effective therapeutic agents with minimal side effects for prostate cancer (PC) treatment is much needed. Indirubin, an active molecule identified in the traditional Chinese herbal medicine-Qing Dai (Indigo naturalis), has been used to treat leukemia for decades. However, the anticancer properties of Natura-alpha, an indirubin derivative, are not well studied in solid tumors, particularly in PC. The growth kinetics and invasion ability of on human PC cell lines with or without Natura-alpha treatment were measured by cell proliferation and invasion assays. The antitumor effects of Natura-alpha were examined in nude mice tumor xenograft models, and in a patient with advanced hormone-refractory metastatic PC. Signal network proteins targeted by Natura-alpha were analyzed by using proteomic pathway array analysis (PPAA) on xenografts. Natura-alpha inhibited the growth of both androgen-dependent (LNCaP) and androgen-independent (LNCaP-AI, PC-3, and DU145) PC cells with IC(50) between 4 to 10 mmol/L, and also inhibited invasion of androgen-independent PC cells. Its antitumor effects were further evident in in vivo tumor reduction in androgen-dependent and androgen-independent nude mice tumor xenograft models and reduced tumor volume in the patient with hormone refractory metastatic PC. PPAA revealed that antiproliferative and antiinvasive activities of Natura-alpha on PC might primarily be through its downregulation of Forkhead box M1 (FOXM1) protein. Forced overexpression of FOXM1 largely reversed the inhibition of growth and invasion by Natura-alpha. Natura-alpha could serve as a novel and effective therapeutic agent for treatment of both hormone-sensitive and hormone-refractory PC with minimal side effects.

Novel Nine-Exon AR Transcripts (Exon 1/Exon 1b/Exons 2-8) in Normal and Cancerous Breast and Prostate Cells.

PubMed

Hu, Dong Gui; McKinnon, Ross A; Hulin, Julie-Ann; Mackenzie, Peter I; Meech, Robyn

2016-12-27

Nearly 20 different transcripts of the human androgen receptor (AR) are reported with two currently listed as Refseq isoforms in the NCBI database. Isoform 1 encodes wild-type AR (type 1 AR) and isoform 2 encodes the variant AR45 (type 2 AR). Both variants contain eight exons: they share common exons 2-8 but differ in exon 1 with the canonical exon 1 in isoform 1 and the variant exon 1b in isoform 2. Splicing of exon 1 or exon 1b is reported to be mutually exclusive. In this study, we identified a novel exon 1b (1b/TAG) that contains an additional TAG trinucleotide upstream of exon 1b. Moreover, we identified AR transcripts in both normal and cancerous breast and prostate cells that contained either exon 1b or 1b/TAG spliced between the canonical exon 1 and exon 2, generating nine-exon AR transcripts that we have named isoforms 3a and 3b. The proteins encoded by these new AR variants could regulate androgen-responsive reporters in breast and prostate cancer cells under androgen-depleted conditions. Analysis of type 3 AR-GFP fusion proteins showed partial nuclear localization in PC3 cells under androgen-depleted conditions, supporting androgen-independent activation of the AR. Type 3 AR proteins inhibited androgen-induced growth of LNCaP cells. Microarray analysis identified a small set of type 3a AR target genes in LNCaP cells, including genes known to modulate growth and proliferation of prostate cancer ( PCGEM1 , PEG3 , EPHA3 , and EFNB2 ) or other types of human cancers ( TOX3 , ST8SIA4 , and SLITRK3 ), and genes that are diagnostic/prognostic biomarkers of prostate cancer ( GRINA3 , and BCHE ).

Targeting a Novel Androgen Receptor-Repressed Pathway in Prostate Cancer Therapy

DTIC Science & Technology

2017-09-01

AURKA and CENPE. [ Study is on - going] Major Task 3: Test the hypothesis that androgen deprivation-induced PKD1 expression. Major Task 4: Test the...Subtask 3: Conduct detail analysis of the pathway identified in Subtask 2 and assessing its impact on PKD1 expression. This study is on -going. We...enzalutamide, in androgen-sensitivity PrCa cells. We have completed this subtask. In this study , although PKD2 overexpression had little impact on LNCaP

Differential regulation of metabolic pathways by androgen receptor (AR) and its constitutively active splice variant, AR-V7, in prostate cancer cells

PubMed Central

Shafi, Ayesha A.; Putluri, Vasanta; Arnold, James M.; Tsouko, Efrosini; Maity, Suman; Roberts, Justin M.; Coarfa, Cristian; Frigo, Daniel E.; Putluri, Nagireddy; Sreekumar, Arun; Weigel, Nancy L.

2015-01-01

Metastatic prostate cancer (PCa) is primarily an androgen-dependent disease, which is treated with androgen deprivation therapy (ADT). Tumors usually develop resistance (castration-resistant PCa [CRPC]), but remain androgen receptor (AR) dependent. Numerous mechanisms for AR-dependent resistance have been identified including expression of constitutively active AR splice variants lacking the hormone-binding domain. Recent clinical studies show that expression of the best-characterized AR variant, AR-V7, correlates with resistance to ADT and poor outcome. Whether AR-V7 is simply a constitutively active substitute for AR or has novel gene targets that cause unique downstream changes is unresolved. Several studies have shown that AR activation alters cell metabolism. Using LNCaP cells with inducible expression of AR-V7 as a model system, we found that AR-V7 stimulated growth, migration, and glycolysis measured by ECAR (extracellular acidification rate) similar to AR. However, further analyses using metabolomics and metabolic flux assays revealed several differences. Whereas AR increased citrate levels, AR-V7 reduced citrate mirroring metabolic shifts observed in CRPC patients. Flux analyses indicate that the low citrate is a result of enhanced utilization rather than a failure to synthesize citrate. Moreover, flux assays suggested that compared to AR, AR-V7 exhibits increased dependence on glutaminolysis and reductive carboxylation to produce some of the TCA (tricarboxylic acid cycle) metabolites. These findings suggest that these unique actions represent potential therapeutic targets. PMID:26378018

The NLR-related protein NWD1 is associated with prostate cancer and modulates androgen receptor signaling.

PubMed

Correa, Ricardo G; Krajewska, Maryla; Ware, Carl F; Gerlic, Motti; Reed, John C

2014-03-30

Prostate cancer (PCa) is among the leading causes of cancer-related death in men. Androgen receptor (AR) signaling plays a seminal role in prostate development and homeostasis, and dysregulation of this pathway is intimately linked to prostate cancer pathogenesis and progression. Here, we identify the cytosolic NLR-related protein NWD1 as a novel modulator of AR signaling. We determined that expression of NWD1 becomes elevated during prostate cancer progression, based on analysis of primary tumor specimens. Experiments with cultured cells showed that NWD1 expression is up-regulated by the sex-determining region Y (SRY) family proteins. Gene silencing procedures, in conjunction with transcriptional profiling, showed that NWD1 is required for expression of PDEF (prostate-derived Ets factor), which is known to bind and co-regulate AR. Of note, NWD1 modulates AR protein levels. Depleting NWD1 in PCa cell lines reduces AR levels and suppresses activity of androgen-driven reporter genes. NWD1 knockdown potently suppressed growth of androgen-dependent LNCaP prostate cancer cells, thus showing its functional importance in an AR-dependent tumor cell model. Proteomic analysis suggested that NWD1 associates with various molecular chaperones commonly related to AR complexes. Altogether, these data suggest a role for tumor-associated over-expression of NWD1 in dysregulation of AR signaling in PCa.

Synergistic activation of the androgen receptor by bombesin and low-dose androgen.

PubMed

Dai, Jie; Shen, Ruoqian; Sumitomo, Makoto; Stahl, Rosalyn; Navarro, Daniel; Gershengorn, Marvin C; Nanus, David M

2002-07-01

Neuropeptide growth factors such as bombesinare implicated in progression to androgen-independent prostate cancer (PC). We examined the impact of bombesin on androgen receptor (AR)-mediated gene expression. The AR together with the AR-responsive probasin ARR(3)tk-luc or PSA-pPUE-ELB-luc promoter was cotransfected into Swiss 3T3 and PC-3 cells, both of which express high-affinity bombesin receptors; the cells were incubated with bombesin (0-50 nM) and dihydrotestosterone (DHT; 0-10 nM), and luciferase activities were measured. DHT increased transcription approximately 40-fold at doses of 1 and 10 nM but had no effect at 10 pM. Bombesin alone, or with 1 or 10 nM DHT, did not further increase transcription. However, 5 nM bombesin and 10 pM DHT, doses that by themselves had no effect, resulted in a approximately 20 fold increase in transcription (P < 0.005). This synergistic effect was blocked by bombesin receptor antagonists and recombinant neutral endopeptidase, which hydrolyzes bombesin. Bombesin and DHT together also increased binding of nuclear extracts from PC-3 cells transfected with AR to a consensus androgen response element in mobility shift assays and increased the level of secreted prostate-specific antigen in LNCaP cell supernatant compared with DHT or bombesin alone. Immunoprecipitation of AR from (32)P-labeled LNCaP cells revealed that 5 nM bombesin + 10 pM DHT induced AR phosphorylation comparable with 1 nM DHT, whereas bombesin or 10 pM DHT alone did not. These data indicate that bombesin can synergize with low (castrate) levels of DHT to induce AR-mediated transcription and suggest that neuropeptides promote AR-mediated signaling in androgen-independent prostate cancer.

PCA3 noncoding RNA is involved in the control of prostate-cancer cell survival and modulates androgen receptor signaling

PubMed Central

2012-01-01

Background PCA3 is a non-coding RNA (ncRNA) that is highly expressed in prostate cancer (PCa) cells, but its functional role is unknown. To investigate its putative function in PCa biology, we used gene expression knockdown by small interference RNA, and also analyzed its involvement in androgen receptor (AR) signaling. Methods LNCaP and PC3 cells were used as in vitro models for these functional assays, and three different siRNA sequences were specifically designed to target PCA3 exon 4. Transfected cells were analyzed by real-time qRT-PCR and cell growth, viability, and apoptosis assays. Associations between PCA3 and the androgen-receptor (AR) signaling pathway were investigated by treating LNCaP cells with 100 nM dihydrotestosterone (DHT) and with its antagonist (flutamide), and analyzing the expression of some AR-modulated genes (TMPRSS2, NDRG1, GREB1, PSA, AR, FGF8, CdK1, CdK2 and PMEPA1). PCA3 expression levels were investigated in different cell compartments by using differential centrifugation and qRT-PCR. Results LNCaP siPCA3-transfected cells significantly inhibited cell growth and viability, and increased the proportion of cells in the sub G0/G1 phase of the cell cycle and the percentage of pyknotic nuclei, compared to those transfected with scramble siRNA (siSCr)-transfected cells. DHT-treated LNCaP cells induced a significant upregulation of PCA3 expression, which was reversed by flutamide. In siPCA3/LNCaP-transfected cells, the expression of AR target genes was downregulated compared to siSCr-transfected cells. The siPCA3 transfection also counteracted DHT stimulatory effects on the AR signaling cascade, significantly downregulating expression of the AR target gene. Analysis of PCA3 expression in different cell compartments provided evidence that the main functional roles of PCA3 occur in the nuclei and microsomal cell fractions. Conclusions Our findings suggest that the ncRNA PCA3 is involved in the control of PCa cell survival, in part through modulating AR signaling, which may raise new possibilities of using PCA3 knockdown as an additional therapeutic strategy for PCa control. PMID:23130941

Roles for the Stem Cell–Associated Intermediate Filament Nestin in Prostate Cancer Migration and Metastasis

PubMed Central

Kleeberger, Wolfram; Bova, G. Steven; Nielsen, Matthew E.; Herawi, Mehsati; Chuang, Ai-Ying; Epstein, Jonathan I.; Berman, David M.

2011-01-01

The intermediate filament protein Nestin identifies stem/progenitor cells in adult tissues, but the function of Nestin is poorly understood. We investigated Nestin expression and function in common lethal cancers. Nestin mRNA was detected in cell lines from small cell lung, and breast cancers, and particularly elevated in cell lines derived from prostate cancer metastases. Whereas the androgen-independent lines PC3, 22RV1, and DU145 all expressed Nestin transcripts under standard culture conditions, the androgen-dependent line LnCaP expressed Nestin only on androgen withdrawal. We confirmed associations of Nestin expression, androgen withdrawal, and metastatic potential by immunohistochemical analysis of samples from 254 prostate cancer patients. Cytoplasmic Nestin protein was readily identifiable in prostate cancer cells from 75% of patients with lethal androgen-independent disease, even in cancer sampled from the prostate itself. However, Nestin expression was undetectable in localized androgen-deprived tumors and in metastases without prior androgen deprivation. To address its function, we reduced Nestin levels with short hairpin RNAs, markedly inhibiting in vitro migration and invasion in prostate cancer cells but leaving cell growth intact. Nestin knockdown also diminished metastases 5-fold compared with controls despite uncompromised tumorigenicity at the site of inoculation. These results specify a function for Nestin in cell motility and identify a novel pathway for prostate cancer metastasis. Activity of this pathway may be selected by the extraprostatic environment or, as supported by our data, may originate within the prostate after androgen deprivation. Further dissection of this novel Nestin migration pathway may lead to strategies to prevent and neutralize metastatic spread. PMID:17909025

The Role of the Co-Chaperone, CHIP, in Androgen Independent Prostate Cancer

DTIC Science & Technology

2008-02-01

AI018322 PLAC8L1 -3.0452 -2.8869 BF968097 --- -3.3016 -2.6168 BE463997 ARL9 -4.6413 -3.5082 AB018333 SASH1 -2.8681 -2.4297 AA129774 LOC400793 -3.3986...transition, namely CDC2 and cyclin B1, and induces G2/M arrest. 5 B. CHIP gene expression only induced SASH1 gene expression in LNCap but not in...LNCap Tsai and LNCap C42 cells. SASH1 has been implicated to act as a tumour suppressor gene in human breast cancer6. Sash1 has an SH3 region together

Comprehensive Evaluation of the Role of EZH2 in the Growth, Invasion, and Aggression of a Panel of Prostate Cancer Cell Lines

PubMed Central

Karanikolas, Breanne D.W.; Figueiredo, Marxa L.; Wu, Lily

2010-01-01

Background Although most prostate cancers respond well to initial treatments, a fraction of prostate cancers are more aggressive and will recur and metastasize. At that point, there are few treatment options available. Significant efforts have been made to identify biomarkers that will identify these more aggressive cancers to tailor a more vigorous treatment in order to improve outcome. Polycomb Group protein Enhancer of Zeste 2 (EZH2) was found to be overexpressed in metastatic prostate tumors, and is considered an excellent candidate for such a biomarker. Scattered studies have found that EZH2 overexpression causes neoplastic transformation, invasion, and growth of prostate cells. However, these studies utilized different systems and cell lines, and so are difficult to correlate with one another. Methods In this study, a comprehensive evaluation of the phenotypic effects of EZH2 in a panel of five prostate cancer cell lines was performed. By using multiple cell lines, and examining overexpression and knockdown of EZH2 concurrently, a broad view of EZH2's role in prostate cancer was achieved. Results Overexpression of EZH2 led to more aggressive behaviors in all prostate cell lines tested. In contrast, downregulation of EZH2 reduced invasion and tumorigenicity of androgen-independent cell lines CWR22Rv1, PC3, and DU145, but not of androgen-dependent cell lines LAPC4 and LNCaP. Conclusions Findings from this study suggest androgen-independent prostate tumors are more dependent on EZH2 expression than androgen-dependent tumors. Our observations provide an explanation for the strong correlation between EZH2 overexpression and advanced stage, aggressive prostate cancers. PMID:20087897

Preparation of nanobubbles carrying androgen receptor siRNA and their inhibitory effects on androgen-independent prostate cancer when combined with ultrasonic irradiation.

PubMed

Wang, Luofu; Zhang, Miao; Tan, Kaibin; Guo, Yanli; Tong, Haipeng; Fan, Xiaozhou; Fang, Kejing; Li, Rui

2014-01-01

The objective of this study was to investigate nanobubbles carrying androgen receptor (AR) siRNA and their in vitro and in vivo anti-tumor effects, when combined with ultrasonic irradiation, on androgen-independent prostate cancer (AIPC). Nanobubbles carrying AR siRNA were prepared using poly-L-lysine and electrostatic adsorption methods. Using C4-2 cell activity as a testing index, the optimal irradiation parameters (including the nanobubble number/cell number ratio, mechanical index [MI], and irradiation time) were determined and used for transfection of three human prostate cancer cell lines (C4-2, LNCaP, and PC-3 cells). The AR expression levels were investigated with RT-PCR and Western blot analysis. Additionally, the effects of the nanobubbles and control microbubbles named SonoVue were assessed via imaging in a C4-2 xenograft model. Finally, the growth and AR expression of seven groups of tumor tissues were assessed using the C4-2 xenograft mouse model. The nanobubbles had an average diameter of 609.5±15.6 nm and could effectively bind to AR siRNA. Under the optimized conditions of a nanobubble number/cell number ratio of 100∶1, an MI of 1.2, and an irradiation time of 2 min, the highest transfection rates in C4-2, LNCaP, and PC-3 cells were 67.4%, 74.0%, and 63.96%, respectively. In the C4-2 and LNCaP cells, treatment with these binding nanobubbles plus ultrasonic irradiation significantly inhibited cell growth and resulted in the suppression of AR mRNA and protein expression. Additionally, contrast-enhanced ultrasound showed that the nanobubbles achieved stronger signals than the SonoVue control in the central hypovascular area of the tumors. Finally, the anti-tumor effect of these nanobubbles plus ultrasonic irradiation was most significant in the xenograft tumor model compared with the other groups. Nanobubbles carrying AR siRNA could be potentially used as gene vectors in combination with ultrasonic irradiation for the treatment of AIPC.

Preparation of Nanobubbles Carrying Androgen Receptor siRNA and Their Inhibitory Effects on Androgen-Independent Prostate Cancer when Combined with Ultrasonic Irradiation

PubMed Central

Tan, Kaibin; Guo, Yanli; Tong, Haipeng; Fan, Xiaozhou; Fang, Kejing; Li, Rui

2014-01-01

Objective The objective of this study was to investigate nanobubbles carrying androgen receptor (AR) siRNA and their in vitro and in vivo anti-tumor effects, when combined with ultrasonic irradiation, on androgen-independent prostate cancer (AIPC). Materials and Methods Nanobubbles carrying AR siRNA were prepared using poly-L-lysine and electrostatic adsorption methods. Using C4-2 cell activity as a testing index, the optimal irradiation parameters (including the nanobubble number/cell number ratio, mechanical index [MI], and irradiation time) were determined and used for transfection of three human prostate cancer cell lines (C4-2, LNCaP, and PC-3 cells). The AR expression levels were investigated with RT-PCR and Western blot analysis. Additionally, the effects of the nanobubbles and control microbubbles named SonoVue were assessed via imaging in a C4-2 xenograft model. Finally, the growth and AR expression of seven groups of tumor tissues were assessed using the C4-2 xenograft mouse model. Results The nanobubbles had an average diameter of 609.5±15.6 nm and could effectively bind to AR siRNA. Under the optimized conditions of a nanobubble number/cell number ratio of 100∶1, an MI of 1.2, and an irradiation time of 2 min, the highest transfection rates in C4-2, LNCaP, and PC-3 cells were 67.4%, 74.0%, and 63.96%, respectively. In the C4-2 and LNCaP cells, treatment with these binding nanobubbles plus ultrasonic irradiation significantly inhibited cell growth and resulted in the suppression of AR mRNA and protein expression. Additionally, contrast-enhanced ultrasound showed that the nanobubbles achieved stronger signals than the SonoVue control in the central hypovascular area of the tumors. Finally, the anti-tumor effect of these nanobubbles plus ultrasonic irradiation was most significant in the xenograft tumor model compared with the other groups. Conclusion Nanobubbles carrying AR siRNA could be potentially used as gene vectors in combination with ultrasonic irradiation for the treatment of AIPC. PMID:24798477

Natura-Alpha Targets Forkhead Box M1 and Inhibits Androgen-Dependent and -Independent Prostate Cancer Growth and Invasion

PubMed Central

Li, Yirong; Ligr, Martin; McCarron, James P; Daniels, Garrett; Zhang, David; Zhao, Xin; Ye, Fei; Wang, Jinhua; Liu, Xiaomei; Osman, Iman; Mencher, Simon K; Lepor, Hebert; Wang, Long G; Lee, Peng

2011-01-01

Purpose The development of new effective therapeutic agents with minimal side effects for prostate cancer treatment is much needed. Indirubin, an active molecule identified in the traditional Chinese herbal medicine – Qing Dai (Indigo Naturalis), has been used to treat leukemia for decades. However, the anti-cancer properties of Natura-alpha, an indirubin derivative, are not well studied in solid tumors, particularly in prostate cancer. Experimental Design Human prostate cancer cell lines were treated with or without Natura-alpha followed by cell growth and invasion assays measured. The anti-tumor effects of Natura-alpha were examined in nude mice tumor xenograft models, as well as in a patient with advanced hormone refractory metastatic prostate cancer. Signal network proteins targeted by Natura-alpha were analyzed using Proteomic Pathway Array Analysis (PPAA) on xenografts. Results Natura-alpha inhibited the growth of both androgen-dependent (LNCaP), and androgen-independent (LNCaP-AI, PC-3, and DU145) prostate cancer cells with IC50 between 4 to 10 Μm, also inhibits invasion of androgen-independent prostate cancer cells. Its anti-tumor effects were further evident in vivo tumor reduction in androgen-dependent and -independent nude mice tumor xenograft models as well as reduced tumor volume in the patient with hormone refractory metastatic prostate cancer. PPAA revealed that anti-proliferative and anti-invasive activities of Natura-alpha on prostate cancer might primarily be through its down-regulation of Forkhead box M1 (FOXM1) protein. Forced over-expression of FOXM1 largely reversed the inhibition by Natura-alpha. Conclusion Natura-alpha could serve as a novel and effective therapeutic agent for treatment of both hormone sensitive and hormone refractory prostate cancer with minimal side effects. PMID:21606178

VMY-1-103, a dansylated analog of purvalanol B, induces caspase-3-dependent apoptosis in LNCaP prostate cancer cells

PubMed Central

Yenugonda, Venkata Mahidhar; Ghosh, Anup; Divito, Kyle; Trabosh, Valerie; Patel, Yesha; Brophy, Amanda; Grindrod, Scott; Lisanti, Michael P; Rosenthal, Dean; Brown, Milton L; Avantaggiati, Maria Laura; Rodriguez, Olga

2010-01-01

The 2,6,9-trisubstituted purine group of cyclin dependent kinase inhibitors have the potential to be clinically relevant inhibitors of cancer cell proliferation. We have recently designed and synthesized a novel dansylated analog of purvalanol B, termed VMY-1-103, that inhibited cell cycle progression in breast cancer cell lines more effectively than did purvalanol B and allowed for uptake analyses by fluorescence microscopy. ErbB-2 plays an important role in the regulation of signal transduction cascades in a number of epithelial tumors, including prostate cancer (PCa). Our previous studies demonstrated that transgenic expression of activated ErbB-2 in the mouse prostate initiated PCa and either the overexpression of ErbB-2 or the addition of the ErbB-2/ErbB-3 ligand, heregulin (HRG), induced cell cycle progression in the androgen-responsive prostate cancer cell line, LNCaP. In the present study, we tested the efficacy of VMY-1-103 in inhibiting HRG-induced cell proliferation in LNCaP prostate cancer cells. At concentrations as low as 1 µM, VMY-1-103 increased both the proportion of cells in G1 and p21CIP1 protein levels. At higher concentrations (5 µM or 10 µM), VMY-1-103 induced apoptosis via decreased mitochondrial membrane polarity and induction of p53 phosphorylation, caspase-3 activity and PARP cleavage. Treatment with 10 µM Purvalanol B failed to either influence proliferation or induce apoptosis. Our results demonstrate that VMY-1-103 was more effective in inducing apoptosis in PCa cells than its parent compound, purvalanol B, and support the testing of VMY-1-103 as a potential small molecule inhibitor of prostate cancer in vivo. PMID:20574155

Docosahexaenoic acid inhibits the growth of hormone-dependent prostate cancer cells by promoting the degradation of the androgen receptor.

PubMed

Hu, Zhimei; Qi, Haixia; Zhang, Ruixue; Zhang, Kun; Shi, Zhemin; Chang, Yanan; Chen, Linfeng; Esmaeili, Mohsen; Baniahmad, Aria; Hong, Wei

2015-09-01

Epidemiological and preclinical data have demonstrated the preventative effects of ω-3 polyunsaturated fatty acids, including docosahexaenoic acid (DHA), on prostate cancer. However, there are inconsistencies in these previous studies and the underlying mechanisms remain to be elucidated. In the present study, the androgen receptor (AR), which is a transcription factor involved in cell proliferation and prostate carcinogenesis, was identified as a target of DHA. It was revealed that DHA inhibited hormone‑dependent growth of LNCaP prostate cancer cells. Reverse transcription-quantitative polymerase chain reaction analysis revealed that treatment with DHA caused no alteration in the transcribed mRNA expression levels of the AR gene. However, immunoblotting revealed that this treatment reduces the protein expression level of the AR. The androgen‑induced genes were subsequently repressed by treatment with DHA. It was demonstrated that DHA exhibits no effect on the translation process of the AR, however, it promotes the proteasome‑mediated degradation of the AR. Therefore, the present study provided a novel mechanism by which DHA exhibits an inhibitory effect on growth of prostate cancer cells.

Potent antiandrogen and androgen receptor activities of an Angelica gigas-containing herbal formulation: identification of decursin as a novel and active compound with implications for prevention and treatment of prostate cancer.

PubMed

Jiang, Cheng; Lee, Hyo-Jeong; Li, Guang-xun; Guo, Junming; Malewicz, Barbara; Zhao, Yan; Lee, Eun-Ok; Lee, Hyo-Jung; Lee, Jae-Ho; Kim, Min-Seok; Kim, Sung-Hoon; Lu, Junxuan

2006-01-01

Androgen and androgen receptor (AR)-mediated signaling are crucial for the development of prostate cancer. Identification of novel and naturally occurring phytochemicals that target androgen and AR signaling from Oriental medicinal herbs holds exciting promises for the chemoprevention of this disease. In this article, we report the discovery of strong and long-lasting antiandrogen and AR activities of the ethanol extract of a herbal formula (termed KMKKT) containing Korean Angelica gigas Nakai (AGN) root and nine other Oriental herbs in the androgen-dependent LNCaP human prostate cancer cell model. The functional biomarkers evaluated included a suppression of the expression of prostate-specific antigen (PSA) mRNA and protein (IC50, approximately 7 microg/mL, 48-hour exposure) and an inhibition of androgen-induced cell proliferation through G1 arrest and of the ability of androgen to suppress neuroendocrine differentiation at exposure concentrations that did not cause apoptosis. Through activity-guided fractionation, we identified decursin from AGN as a novel antiandrogen and AR compound with an IC50 of approximately 0.4 microg/mL (1.3 micromol/L, 48-hour exposure) for suppressing PSA expression. Decursin also recapitulated the neuroendocrine differentiation induction and G1 arrest actions of the AGN and KMKKT extracts. Mechanistically, decursin in its neat form or as a component of AGN or KMKKT extracts inhibited androgen-stimulated AR translocation to the nucleus and down-regulated AR protein abundance without affecting the AR mRNA level. The novel antiandrogen and AR activities of decursin and decursin-containing herbal extracts have significant implications for the chemoprevention and treatment of prostate cancer and other androgen-dependent diseases.

Elucidation of the Molecular Mechanisms Underlying Lymph Node Metastasis in Prostate Cancer

DTIC Science & Technology

2005-10-01

overexpressed (Figure 8B). This result is significant for two reasons. First, it provides a mechanistic explanation for how FOXO-1, activated by SIRT1 ...transcription (Figure 4c). This result was confirmed when we used the dominant-negative form of SIRT1 to inhibit its activity (Figure 4d). SIRT-1DN protein... activated by SIRT1 , can act to Figure 3 (a) Androgen increases the IGF-IR protein level in LNCaP. LNCaP cells were grown in the charcoal–dextran

Melatonin Inhibits Androgen Receptor Splice Variant-7 (AR-V7)-Induced Nuclear Factor-Kappa B (NF-κB) Activation and NF-κB Activator-Induced AR-V7 Expression in Prostate Cancer Cells: Potential Implications for the Use of Melatonin in Castration-Resistant Prostate Cancer (CRPC) Therapy.

PubMed

Liu, Vincent Wing Sun; Yau, Wing Lung; Tam, Chun Wai; Yao, Kwok-Ming; Shiu, Stephen Yuen Wing

2017-05-31

A major current challenge in the treatment of advanced prostate cancer, which can be initially controlled by medical or surgical castration, is the development of effective, safe, and affordable therapies against progression of the disease to the stage of castration resistance. Here, we showed that in LNCaP and 22Rv1 prostate cancer cells transiently overexpressing androgen receptor splice variant-7 (AR-V7), nuclear factor-kappa B (NF-κB) was activated and could result in up-regulated interleukin ( IL ) -6 gene expression, indicating a positive interaction between AR-V7 expression and activated NF-κB/IL-6 signaling in castration-resistant prostate cancer (CRPC) pathogenesis. Importantly, both AR-V7-induced NF-κB activation and IL-6 gene transcription in LNCaP and 22Rv1 cells could be inhibited by melatonin. Furthermore, stimulation of AR-V7 mRNA expression in LNCaP cells by betulinic acid, a pharmacological NF-κB activator, was reduced by melatonin treatment. Our data support the presence of bi-directional positive interactions between AR-V7 expression and NF-κB activation in CRPC pathogenesis. Of note, melatonin, by inhibiting NF-κB activation via the previously-reported MT₁ receptor-mediated antiproliferative pathway, can disrupt these bi-directional positive interactions between AR-V7 and NF-κB and thereby delay the development of castration resistance in advanced prostate cancer. Apparently, this therapeutic potential of melatonin in advanced prostate cancer/CRPC management is worth translation in the clinic via combined androgen depletion and melatonin repletion.

Melatonin Inhibits Androgen Receptor Splice Variant-7 (AR-V7)-Induced Nuclear Factor-Kappa B (NF-κB) Activation and NF-κB Activator-Induced AR-V7 Expression in Prostate Cancer Cells: Potential Implications for the Use of Melatonin in Castration-Resistant Prostate Cancer (CRPC) Therapy

PubMed Central

Liu, Vincent Wing Sun; Yau, Wing Lung; Tam, Chun Wai; Yao, Kwok-Ming; Shiu, Stephen Yuen Wing

2017-01-01

A major current challenge in the treatment of advanced prostate cancer, which can be initially controlled by medical or surgical castration, is the development of effective, safe, and affordable therapies against progression of the disease to the stage of castration resistance. Here, we showed that in LNCaP and 22Rv1 prostate cancer cells transiently overexpressing androgen receptor splice variant-7 (AR-V7), nuclear factor-kappa B (NF-κB) was activated and could result in up-regulated interleukin (IL)-6 gene expression, indicating a positive interaction between AR-V7 expression and activated NF-κB/IL-6 signaling in castration-resistant prostate cancer (CRPC) pathogenesis. Importantly, both AR-V7-induced NF-κB activation and IL-6 gene transcription in LNCaP and 22Rv1 cells could be inhibited by melatonin. Furthermore, stimulation of AR-V7 mRNA expression in LNCaP cells by betulinic acid, a pharmacological NF-κB activator, was reduced by melatonin treatment. Our data support the presence of bi-directional positive interactions between AR-V7 expression and NF-κB activation in CRPC pathogenesis. Of note, melatonin, by inhibiting NF-κB activation via the previously-reported MT1 receptor-mediated antiproliferative pathway, can disrupt these bi-directional positive interactions between AR-V7 and NF-κB and thereby delay the development of castration resistance in advanced prostate cancer. Apparently, this therapeutic potential of melatonin in advanced prostate cancer/CRPC management is worth translation in the clinic via combined androgen depletion and melatonin repletion. PMID:28561752

ARP2, a novel pro-apoptotic protein expressed in epithelial prostate cancer LNCaP cells and epithelial ovary CHO transformed cells.

PubMed

Mas-Oliva, Jaime; Navarro-Vidal, Enrique; Tapia-Vieyra, Juana Virginia

2014-01-01

Neoplastic epithelial cells generate the most aggressive types of cancers such as those located in the lung, breast, colon, prostate and ovary. During advanced stages of prostate cancer, epithelial cells are associated to the appearance of androgen-independent tumors, an apoptotic-resistant phenotype that ultimately overgrows and promotes metastatic events. We have previously identified and electrophysiologically characterized a novel Ca(2+)-permeable channel activated during apoptosis in the androgen-independent prostate epithelial cancer cell line, LNCaP. In addition, we reported for the first time the cloning and characterization of this channel-like molecule named apoptosis regulated protein 2 (ARP2) associated to a lethal influx of Ca(2+) in Xenopus oocytes. In the present study, LNCaP cells and Chinese hamster ovary cells (CHO cell line) transfected with arp2-cDNA are induced to undergo apoptosis showing an important impact on cell viability and activation of caspases 3 and 7 when compared to serum deprived grown cells and ionomycin treated cells. The subcellular localization of ARP2 in CHO cells undergoing apoptosis was studied using confocal microscopy. While apoptosis progresses, ARP2 initially localized in the peri-nuclear region of cells migrates with time towards the plasma membrane region. Based on the present results and those of our previous studies, the fact that ARP2 constitutes a novel cation channel is supported. Therefore, ARP2 becomes a valuable target to modulate the influx and concentration of calcium in the cytoplasm of epithelial cancer cells showing an apoptotic-resistant phenotype during the onset of an apoptotic event.

FOXM1 promotes the progression of prostate cancer by regulating PSA gene transcription.

PubMed

Liu, Youhong; Liu, Yijun; Yuan, Bowen; Yin, Linglong; Peng, Yuchong; Yu, Xiaohui; Zhou, Weibing; Gong, Zhicheng; Liu, Jianye; He, Leye; Li, Xiong

2017-03-07

Androgen/AR is the primary contributor to prostate cancer (PCa) progression by regulating Prostate Specific Antigen (PSA) gene transcription. The disease inevitably evolves to androgen-independent (AI) status. Other mechanisms by which PSA is regulated and develops to AI have not yet been fully determined. FOXM1 is a cell proliferation-specific transcription factor highly expressed in PCa cells compared to non-malignant prostate epithelial cells, suggesting that the aberrant overexpression of FOXM1 contributes to PCa development. In addition to regulating AR gene transcription and cell cycle-regulatory genes, FOXM1 selectively regulates the gene transcription of KLK2 and PSA, typical androgen responsive genes. Screening the potential FOXM1-binding sites by ChIP-PCR, we found that FOXM1 directly binds to the FHK binding motifs in the PSA promoter/enhancer regions. AI C4-2 cells have more FOXM1 binding sites than androgen dependent LNCaP cells. The depletion of FOXM1 by small molecular inhibitors significantly improves the suppression of PSA gene transcription by the anti-AR agent Cadosax. This is the first report showing that FOXM1 promotes PCa progression by regulating PSA gene transcription, particularly in AI PCa cells. The combination of anti-AR agents and FOXM1 inhibitors has the potential to greatly improve therapy for late-stage PCa patients by suppressing PSA levels.

The inhibitory effects of capillarisin on cell proliferation and invasion of prostate carcinoma cells.

PubMed

Tsui, Ke-Hung; Chang, Ying-Ling; Yang, Pei-Shan; Hou, Chen-Pang; Lin, Yu-Hsiang; Lin, Bing-Wei; Feng, Tsui-Hsia; Juang, Horng-Heng

2018-04-01

Capillarisin (Cap), an active component of Artemisia capillaris root extracts, is characterized by its anti-inflammatory, anti-oxidant and anti-cancer properties. Nevertheless, the functions of Cap in prostate cancer have not been fully explored. We evaluated the potential actions of Cap on the cell proliferation, migration and invasion of prostate carcinoma cells. Cell proliferation and cell cycle distribution were measured by water-soluble tetrazolium-1 and flow cytometry assays. The expression of cyclins, p21, p27, survivin, matrix metallopeptidase (MMP2 and MMP9) were assessed by immunoblotting assays. Effects of Cap on invasion and migration were determined by wound closure and matrigel transmigration assays. The constitutive and interlukin-6 (IL-6)-inducible STAT3 activation of prostate carcinoma cells were determined by immunoblotting and reporter assays. Capillarisin inhibited androgen-independent DU145 and androgen-dependent LNCaP cell growth through the induction of cell cycle arrest at the G0/G1 phase by upregulating p21 and p27 while downregulating expression of cyclin D1, cyclin A and cyclin B. Cap decreased protein expression of survivin, MMP-2, and MMP-9 and therefore blocked the migration and invasion of DU145 cells. Cap suppressed constitutive and IL-6-inducible STAT3 activation in DU145 and LNCaP cells. Our data indicate that Cap blocked cell growth by modulation of p21, p27 and cyclins. The inhibitory effects of Cap on survivin, MMP-2, MMP-9 and STAT3 activation may account for the suppression of invasion in prostate carcinoma cells. Our data suggest that Cap might be a therapeutic agent in treating advanced prostate cancer with constitutive STAT3 or IL-6-inducible STAT3 activation. © 2017 John Wiley & Sons Ltd.

Suppression of ErbB-2 in androgen-independent human prostate cancer cells enhances cytotoxic effect by gemcitabine in an androgen-reduced environment.

PubMed

Zhang, Li; Davis, Jeffrey S; Zelivianski, Stanislav; Lin, Fen-Fen; Schutte, Rachel; Davis, Thomas L; Hauke, Ralph; Batra, Surinder K; Lin, Ming-Fong

2009-11-18

We examined the efficacy of combination treatments utilizing cytotoxic drugs plus inhibitors to members of the ErbB-ERK signal pathway in human prostate cancer (PCa) LNCaP C-81 cells. Under an androgen-reduced condition, 50nM gemcitabine caused about 40% growth suppression on C-81 cells. Simultaneous treatment of gemcitabine plus 10microM AG825 produced 60% suppression (p<0.03); while, 85% growth inhibition (p<0.02) was seen if AG825 was added to gemcitabine-treated cells after a 24h-interval. Our data thus showed that in androgen-reduced conditions, inhibition of ErbB-2 increases the cytotoxic efficacy of gemcitabine in PCa cells. This finding has significant implications in the choice of drugs for combination therapy as well as the order of administration for treating cancer patients.

Novel Nine-Exon AR Transcripts (Exon 1/Exon 1b/Exons 2–8) in Normal and Cancerous Breast and Prostate Cells

PubMed Central

Hu, Dong Gui; McKinnon, Ross A.; Hulin, Julie-Ann; Mackenzie, Peter I.; Meech, Robyn

2016-01-01

Nearly 20 different transcripts of the human androgen receptor (AR) are reported with two currently listed as Refseq isoforms in the NCBI database. Isoform 1 encodes wild-type AR (type 1 AR) and isoform 2 encodes the variant AR45 (type 2 AR). Both variants contain eight exons: they share common exons 2–8 but differ in exon 1 with the canonical exon 1 in isoform 1 and the variant exon 1b in isoform 2. Splicing of exon 1 or exon 1b is reported to be mutually exclusive. In this study, we identified a novel exon 1b (1b/TAG) that contains an additional TAG trinucleotide upstream of exon 1b. Moreover, we identified AR transcripts in both normal and cancerous breast and prostate cells that contained either exon 1b or 1b/TAG spliced between the canonical exon 1 and exon 2, generating nine-exon AR transcripts that we have named isoforms 3a and 3b. The proteins encoded by these new AR variants could regulate androgen-responsive reporters in breast and prostate cancer cells under androgen-depleted conditions. Analysis of type 3 AR-GFP fusion proteins showed partial nuclear localization in PC3 cells under androgen-depleted conditions, supporting androgen-independent activation of the AR. Type 3 AR proteins inhibited androgen-induced growth of LNCaP cells. Microarray analysis identified a small set of type 3a AR target genes in LNCaP cells, including genes known to modulate growth and proliferation of prostate cancer (PCGEM1, PEG3, EPHA3, and EFNB2) or other types of human cancers (TOX3, ST8SIA4, and SLITRK3), and genes that are diagnostic/prognostic biomarkers of prostate cancer (GRINA3, and BCHE). PMID:28035996

Lignans isolated from Campylotropis hirtella (Franch.) Schindl. decreased prostate specific antigen and androgen receptor expression in LNCaP cells.

PubMed

Han, Hui-Ying; Wang, Xiang-Hong; Wang, Nai-Li; Ling, Ming-Tat; Wong, Yong-Chuan; Yao, Xin-Sheng

2008-08-27

Accumulating epidemiological data suggest that Asian men have lower incidences of prostate cancer and benign prostate hyperplasia (BPH) compared with American and European populations and may have benefited from their higher intake of phytoestrogens in their diet. However, how these phytochemicals affect prostatic diseases is still unclear. In this study, we isolated six lignans from a plant, Campylotropis hirtella (Franch.) Schindl., which has been used as a folk medicine for treatment of BPH in China, through bioassay guided fractionation. They were dehydrodiconiferyl alcohol (C1), 4-[(-6-hydroxy-2,3-dihydro-1-benzofuran-3-yl)methyl]-5-methoxybenzene-1,3-diol (C2), erythro-guaiacylglycerol-beta-O-4'-coniferyl ether (C3), threo-guaiacylglycerol-beta-O-4'-coniferyl ether (C4), secoisolariciresinol (C5), and prupaside (C6), where C2 was identified as a new lignan analog. Their IC50 values for inhibition of prostate specific antigen (PSA) secretion were 19, 45, 110, 128, 137, and 186 microM, respectively, from C1 to C6 in LNCaP cells. Further study showed that C1-5 down-regulated cellular PSA expression and C1-4 also decreased androgen receptor (AR) expression in LNCaP cells. Furthermore, we investigated the proapoptotic effect of C1 on LNCaP cells. The active forms of caspase 3 associated with the specific proteolysis of poly (ADP-ribose) polymerase (PARP) were detected, and the antiapoptotic protein Bcl-2 was down-regulated after the treatment with C1. These results collectively indicated that these lignans may have chemopreventive or therapeutic actions for prostate cancer through suppressing AR signaling pathway and inducing apoptosis.

Resistance to docetaxel in prostate cancer is associated with androgen receptor activation and loss of KDM5D expression

PubMed Central

Komura, Kazumasa; Jeong, Seong Ho; Hinohara, Kunihiko; Qu, Fangfang; Wang, Xiaodong; Hiraki, Masayuki; Azuma, Haruhito; Lee, Gwo-Shu Mary; Kantoff, Philip W.; Sweeney, Christopher J.

2016-01-01

The androgen receptor (AR) plays an essential role in prostate cancer, and suppression of its signaling with androgen deprivation therapy (ADT) has been the mainstay of treatment for metastatic hormone-sensitive prostate cancer for more than 70 y. Chemotherapy has been reserved for metastatic castration-resistant prostate cancer (mCRPC). The Eastern Cooperative Oncology Group-led trial E3805: ChemoHormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) showed that the addition of docetaxel to ADT prolonged overall survival compared with ADT alone in patients with metastatic hormone-sensitive prostate cancer. This finding suggests that there is an interaction between AR signaling activity and docetaxel sensitivity. Here we demonstrate that the prostate cancer cell lines LNCaP and LAPC4 display markedly different sensitivity to docetaxel with AR activation, and RNA-seq analysis of these cell lines identified KDM5D (lysine-specific demethylase 5D) encoded on the Y chromosome as a potential mediator of this sensitivity. Knocking down KDM5D expression in LNCaP leads to docetaxel resistance in the presence of dihydrotestosterone. KDM5D physically interacts with AR in the nucleus, and regulates its transcriptional activity by demethylating H3K4me3 active transcriptional marks. Attenuating KDM5D expression dysregulates AR signaling, resulting in docetaxel insensitivity. KDM5D deletion was also observed in the LNCaP-derived CRPC cell line 104R2, which displayed docetaxel insensitivity with AR activation, unlike parental LNCaP. Dataset analysis from the Oncomine database revealed significantly decreased KDM5D expression in CRPC and poorer prognosis with low KDM5D expression. Taking these data together, this work indicates that KDM5D modulates the AR axis and that this is associated with altered docetaxel sensitivity. PMID:27185910

ERBB2 Increases Metastatic Potentials Specifically in Androgen-Insensitive Prostate Cancer Cells

PubMed Central

Tome-Garcia, Jessica; Li, Dan; Ghazaryan, Seda; Shu, Limin; Wu, Lizhao

2014-01-01

Despite all the blood-based biomarkers used to monitor prostate cancer patients, prostate cancer remains as the second common cause of cancer mortality in men in the United States. This is largely due to a lack of understanding of the molecular pathways that are responsible for the aggressive forms of prostate cancers, the castrate-resistant prostate cancer and the metastatic prostate cancer. Cell signaling pathways activated by the ERBB2 oncogene or the RAS oncogene are frequently found to be altered in metastatic prostate cancers. To evaluate and define the role of the ERBB2/RAS pathway in prostate cancer metastasis, we have evaluated the impact of ERBB2- or RAS-overexpression on the metastatic potentials for four prostate cancer cell lines derived from tumors with different androgen sensitivities. To do so, we transfected the human DU145, LnCaP, and PC3 prostate cancer cells and the murine Myc-CaP prostate cancer cells with the activated form of ERBB2 or H-RAS and assessed their metastatic potentials by three complementary assays, a wound healing assay, a transwell motility assay, and a transwell invasion assay. We showed that while overexpression of ERBB2 increased the metastatic potential of the androgen-insensitive prostate cancer cells (i.e. PC3 and DU145), it did not affect metastatic potentials of the androgen-sensitive prostate cancer cells (i.e. LnCaP and Myc-CaP). In contrast, overexpression of H-RAS only increased the cell motility of Myc-CaP cells, which overexpress the human c-MYC oncogene. Our data suggest that ERBB2 collaborates with androgen signaling to promote prostate cancer metastasis, and that although RAS is one of the critical downstream effectors of ERBB2, it does not phenocopy ERBB2 for its impact on the metastatic potentials of prostate cancer cell lines. PMID:24937171

Elevated YKL40 is associated with advanced prostate cancer (PCa) and positively regulates invasion and migration of PCa cells

PubMed Central

Jeet, Varinder; Tevz, Gregor; Lehman, Melanie; Hollier, Brett; Nelson, Colleen

2014-01-01

Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in tumours from patients with advanced stage cancers, including prostate cancer (PCa). The exact function of YKL40 is poorly understood, but it has been shown to play an important role in promoting tumour angiogenesis and metastasis. The therapeutic value and biological function of YKL40 are unknown in PCa. The objective of this study was to examine the expression and function of YKL40 in PCa. Gene expression analysis demonstrated that YKL40 was highly expressed in metastatic PCa cells when compared with less invasive and normal prostate epithelial cell lines. In addition, the expression was primarily limited to androgen receptor-positive cell lines. Evaluation of YKL40 tissue expression in PCa patients showed a progressive increase in patients with aggressive disease when compared with those with less aggressive cancers and normal controls. Treatment of LNCaP and C4-2B cells with androgens increased YKL40 expression, whereas treatment with an anti-androgen agent decreased the gene expression of YKL40 in androgen-sensitive LNCaP cells. Furthermore, knockdown of YKL40 significantly decreased invasion and migration of PCa cells, whereas overexpression rendered them more invasive and migratory, which was commensurate with an enhancement in the anchorage-independent growth of cells. To our knowledge, this study characterises the role of YKL40 for the first time in PCa. Together, these results suggest that YKL40 plays an important role in PCa progression and thus inhibition of YKL40 may be a potential therapeutic strategy for the treatment of PCa. PMID:24981110

Elevated YKL40 is associated with advanced prostate cancer (PCa) and positively regulates invasion and migration of PCa cells.

PubMed

Jeet, Varinder; Tevz, Gregor; Lehman, Melanie; Hollier, Brett; Nelson, Colleen

2014-10-01

Chitinase 3-like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in tumours from patients with advanced stage cancers, including prostate cancer (PCa). The exact function of YKL40 is poorly understood, but it has been shown to play an important role in promoting tumour angiogenesis and metastasis. The therapeutic value and biological function of YKL40 are unknown in PCa. The objective of this study was to examine the expression and function of YKL40 in PCa. Gene expression analysis demonstrated that YKL40 was highly expressed in metastatic PCa cells when compared with less invasive and normal prostate epithelial cell lines. In addition, the expression was primarily limited to androgen receptor-positive cell lines. Evaluation of YKL40 tissue expression in PCa patients showed a progressive increase in patients with aggressive disease when compared with those with less aggressive cancers and normal controls. Treatment of LNCaP and C4-2B cells with androgens increased YKL40 expression, whereas treatment with an anti-androgen agent decreased the gene expression of YKL40 in androgen-sensitive LNCaP cells. Furthermore, knockdown of YKL40 significantly decreased invasion and migration of PCa cells, whereas overexpression rendered them more invasive and migratory, which was commensurate with an enhancement in the anchorage-independent growth of cells. To our knowledge, this study characterises the role of YKL40 for the first time in PCa. Together, these results suggest that YKL40 plays an important role in PCa progression and thus inhibition of YKL40 may be a potential therapeutic strategy for the treatment of PCa. © 2014 The authors.

Microarray Data Mining for Potential Selenium Targets in Chemoprevention of Prostate Cancer

PubMed Central

ZHANG, HAITAO; DONG, YAN; ZHAO, HONGJUAN; BROOKS, JAMES D.; HAWTHORN, LESLEYANN; NOWAK, NORMA; MARSHALL, JAMES R.; GAO, ALLEN C.; IP, CLEMENT

2008-01-01

Background A previous clinical trial showed that selenium supplementation significantly reduced the incidence of prostate cancer. We report here a bioinformatics approach to gain new insights into selenium molecular targets that might be relevant to prostate cancer chemoprevention. Materials and Methods We first performed data mining analysis to identify genes which are consistently dysregulated in prostate cancer using published datasets from gene expression profiling of clinical prostate specimens. We then devised a method to systematically analyze three selenium microarray datasets from the LNCaP human prostate cancer cells, and to match the analysis to the cohort of genes implicated in prostate carcinogenesis. Moreover, we compared the selenium datasets with two datasets obtained from expression profiling of androgen-stimulated LNCaP cells. Results We found that selenium reverses the expression of genes implicated in prostate carcinogenesis. In addition, we found that selenium could counteract the effect of androgen on the expression of a subset obtained from androgen-regulated genes. Conclusions The above information provides us with a treasure of new clues to investigate the mechanism of selenium chemoprevention of prostate cancer. Furthermore, these selenium target genes could also serve as biomarkers in future clinical trials to gauge the efficacy of selenium intervention. PMID:18548127

Reactivation of Embryonic Nodal Signaling is Associated with Tumor Progression and Promotes the Growth of Prostate Cancer Cells

PubMed Central

Lawrence, Mitchell G.; Margaryan, Naira V.; Loessner, Daniela; Collins, Angus; Kerr, Kris M.; Turner, Megan; Seftor, Elisabeth A.; Stephens, Carson R.; Lai, John; BioResource, APC; Postovit, Lynne-Marie; Clements, Judith A.; Hendrix, Mary J.C.

2011-01-01

Background Nodal is a member of the Transforming Growth Factor β (TGFβ) superfamily that directs embryonic patterning and promotes the plasticity and tumorigenicity of tumor cells, but its role in the prostate is unknown. The goal of this study was to characterize the expression and function of Nodal in prostate cancer and determine whether, like other TGFβ ligands, it modulates androgen receptor (AR) activity. Methods Nodal expression was investigated using immunohistochemistry of tissue microarrays and Western blots of prostate cell lines. The functional role of Nodal was examined using Matrigel and soft agar growth assays. Cross-talk between Nodal and AR signaling was assessed with luciferase reporter assays and expression of endogenous androgen regulated genes. Results Significantly increased Nodal expression was observed in cancer compared with benign prostate specimens. Nodal was only expressed by DU145 and PC3 cells. All cell lines expressed Nodal’s co-receptor, Cripto-1, but lacked Lefty, a critical negative regulator of Nodal signaling. Recombinant human Nodal triggered downstream Smad2 phosphorylation in DU145 and LNCaP cells, and stable transfection of pre-pro-Nodal enhanced the growth of LNCaP cells in Matrigel and soft agar. Finally, Nodal attenuated AR signaling, reducing the activity of a PSA promoter construct in luciferase assays and down-regulating the endogenous expression of androgen regulated genes. Conclusions An aberrant Nodal signaling pathway is re-expressed and functionally active in prostate cancer cells. PMID:21656830

SLCO2B1 and SLCO1B3 as New Targets for Enhancing Androgen Deprivation Therapy for Prostate Cancer

DTIC Science & Technology

2015-10-01

that statins block DHEAS uptake by competitively binding to SLCO2B1. We examined the effect of four different statins ( atorvastatin , fluvastatin...300 pmol/mg compared to ~60 pmol/mg protein for LNCaP (Fig. 2B). 100 µM atorvastatin significantly decreased DHEAS influx by ~50% in both cell...or even 100 µM atorvastatin or simvastatin was insufficient to inhibit DHEAS uptake in LNCaP, which has a relatively low level of SLCO2B1 expression

Lin28 induces resistance to anti-androgens via promotion of AR splice variant generation.

PubMed

Tummala, Ramakumar; Nadiminty, Nagalakshmi; Lou, Wei; Evans, Christopher P; Gao, Allen C

2016-04-01

Prostate cancer (PCa) is androgen-dependent initially and progresses to a castration-resistant state after androgen deprivation therapy. Treatment options for castration-resistant PCa include the potent second-generation anti-androgen enzalutamide or CYP17A1 inhibitor abiraterone. Recent clinical observations point to the development of resistance to these therapies which may be mediated by constitutively active alternative splice variants of the androgen receptor (AR). Sensitivity of LNCaP cells overexpressing Lin28 (LN-Lin28) to enzalutamide, abiraterone, or bicalutamide was compared to that of control LN-neo cells using cell growth assays, proliferation assays using MTT, anchorage-dependent clonogenic ability assays and soft agar assays. Ability of LN-Lin28 cells to maintain AR activation after treatment with enzalutamide, abiraterone, or bicalutamide was tested using immunofluorescence, Western blotting, ChIP assays, and qRT-PCR. Importance of Lin28 in enzalutamide resistance was assessed by the downregulation of Lin28 expression in C4-2B and 22Rv1 cells chronically treated with enzalutamide. Requirement for sustained AR signaling in LN-Lin28 cells was examined by the downregulation of either full length AR or AR-V7 using siRNA. We show that Lin28 promotes the development of resistance to currently used targeted therapeutics by enhancing the expression of AR splice variants such as AR-V7. PCa cells overexpressing Lin28 exhibit resistance to treatment with enzalutamide, abiraterone, or bicalutamide. Downregulation of Lin28 resensitizes enzalutamide-resistant PCa cells to enzalutamide treatment. We also show that the upregulation of splicing factors such as hnRNPA1 by Lin28 may mediate the enhanced generation of AR splice variants in Lin28-expressing cells. Our findings suggest that Lin28 plays a key role in the acquisition of resistance to AR-targeted therapies by PCa cells and establish the importance of Lin28 in PCa progression. © 2015 Wiley Periodicals, Inc.

Purple corn color inhibition of prostate carcinogenesis by targeting cell growth pathways.

PubMed

Long, Ne; Suzuki, Shugo; Sato, Shinya; Naiki-Ito, Aya; Sakatani, Keisuke; Shirai, Tomoyuki; Takahashi, Satoru

2013-03-01

Purple corn color is a widely used food colorant that was reported to have attenuating effects on hypertension, diabetes, and to have anti-cancer effects on colon and breast cancer. Our study is the first on its possible chemoprevention effects against prostate cancer. For this purpose an androgen-dependent prostate cancer cell line, LNCaP, was used to examine effects in vitro. Purple corn color inhibited the proliferation of LNCaP cells by decreasing the expression of Cyclin D1 and inhibiting the G1 stage of the cell cycle. Thirty-six male transgenic rats for adenocarcinoma of prostate were fed basic diet or diet with purple corn color for 8 weeks. Purple corn color decreased the incidence of adenocarcinoma in the lateral prostate and slowed down the progression of prostate cancer. A lower Ki67 positive rate, a decrease of the expression of Cyclin D1, and downregulation of the activation of Erk1/2 and p38 MAPK were observed in the group consuming purple corn color in the diet. Since purple corn color is a mixture, determining its active component should help in the understanding and usage of purple corn color for prostate cancer chemoprevention. Therefore, the three major anthocyanins in purple corn color, cyanidin-3-glucoside, pelargonidin-3-glucoside and peonidin-3-glucoside, were tested with LNCaP cells. The results suggested that cyanidin-3-glucoside and pelargonidin-3-glucoside are the active compounds. © 2012 Japanese Cancer Association.

Plk1 is upregulated in androgen-insensitive prostate cancer cells and its inhibition leads to necroptosis

PubMed Central

Deeraksa, Arpaporn; Pan, Jing; Sha, Youbao; Liu, Xian-De; Eissa, N Tony; Lin, Sue-Hwa; Yu-Lee, Li-yuan

2012-01-01

Castration-resistant prostate cancer (PCa) is refractory to hormone therapy and new strategies for treatment are urgently needed. We found that androgen-insensitive (AI) PCa cells, LNCaP-AI, are reprogrammed to upregulate the mitotic kinase Plk1 and other M phase cell cycle proteins, which may underlie AI PCa growth. In androgen-depleted media, LNCaP-AI cells showed exquisite sensitivity to growth inhibition by subnanomolar concentrations of a small molecule inhibitor of Plk1, BI2536, suggesting that these cells are dependent on Plk1 for growth. In contrast, the androgen-responsive parental LNCaP cells showed negligible responses to BI2536 treatment under the same condition. BI2536 treatment of LNCaP-AI cells resulted in an increase in cell death marker PARP-1 but did not activate caspase-3, an apoptosis marker, suggesting that the observed cell death was caspase-independent. BI2536-treated LNCaP-AI cells formed multinucleated giant cells that contain clusters of nuclear vesicles indicative of mitotic catastrophe. Live-cell time-lapse imaging revealed that BI2536-treated giant LNCaP-AI cells underwent necroptosis, as evidenced by “explosive” cell death and partial reversal of cell death by a necroptosis inhibitor. Our studies suggest that LNCaP-AI cells underwent reprogramming in both their cell growth and cell death pathways, rendering them highly sensitive to Plk1 inhibition that induces necroptosis. Harnessing necroptosis through Plk1 inhibition may be explored for therapeutic intervention of castration-resistant PCa. PMID:22890325

Proteasome-associated deubiquitinase ubiquitin-specific protease 14 regulates prostate cancer proliferation by deubiquitinating and stabilizing androgen receptor.

PubMed

Liao, Yuning; Liu, Ningning; Hua, Xianliang; Cai, Jianyu; Xia, Xiaohong; Wang, Xuejun; Huang, Hongbiao; Liu, Jinbao

2017-02-02

Androgen receptor (AR) is frequently over-expressed and plays a critical role in the growth and progression of human prostate cancer. The therapy attempting to target AR signalling was established in decades ago but the treatment of prostate cancer is far from being satisfactory. The assignable cause is that our understanding of the mechanism of AR regulation and re-activation remains incomplete. Increasing evidence suggests that deubiquitinases are involved in the regulation of cancer development and progression but the specific underlying mechanism often is not elucidated. In the current study, we have identified ubiquitin-specific protease 14 (USP14) as a novel regulator of AR, inhibiting the degradation of AR via deubiquitinating this oncoprotein in the androgen-responsive prostate cancer cells. We found that (i) USP14 could bind to AR, and additionally, both genetic and pharmacological inhibition of USP14 accelerated the ubiquitination and degradation of AR; (ii) downregulation or inhibition of USP14 suppressed cell proliferation and colony formation of LNcap cells and, conversely, overexpression of USP14 promoted the proliferation; and (iii) reduction or inhibition of USP14 induced G0/G1 phase arrest in LNcap prostate cancer cells. Hence, we conclude that USP14 promotes prostate cancer progression likely through stabilization of AR, suggesting that USP14 could be a promising therapeutic target for prostate cancer.

ROCK mediates phorbol ester-induced apoptosis in prostate cancer cells via p21Cip1 up-regulation and JNK.

PubMed

Xiao, Liqing; Eto, Masumi; Kazanietz, Marcelo G

2009-10-23

It is established that androgen-dependent prostate cancer cells undergo apoptosis upon treatment with phorbol esters and related analogs, an effect primarily mediated by PKCdelta. Treatment of LNCaP prostate cancer cells with phorbol 12-myristate 13-acetate (PMA) causes a strong and sustained activation of RhoA and its downstream effector ROCK (Rho kinase) as well as the formation of stress fibers. These effects are impaired in cells subjected to PKCdelta RNA interference depletion. Functional studies revealed that expression of a dominant negative RhoA mutant or treatment with the ROCK inhibitor Y-27632 inhibits the apoptotic effect of PMA in LNCaP cells. Remarkably, the cytoskeleton inhibitors cytochalasin B and blebbistatin blocked not only PMA-induced apoptosis but also the activation of JNK, a mediator of the cell death effect by the phorbol ester. In addition, we found that up-regulation of the cell cycle inhibitor p21(Cip1) is required for PMA-induced apoptosis and that inhibitors of ROCK or the cytoskeleton organization prevent p21(Cip1) induction. Real time PCR analysis and reporter gene assay revealed that PMA induces p21(Cip1) transcriptionally in a ROCK- and cytoskeleton-dependent manner. p21(Cip1) promoter analysis revealed that PMA induction is dependent on Sp1 elements in the p21(Cip1) promoter but independent of p53. Taken together, our studies implicate ROCK-mediated up-regulation of p21(Cip1) and the cytoskeleton in PKCdelta-dependent apoptosis in prostate cancer cells.

Withaferin A Induces Cell Death Selectively in Androgen-Independent Prostate Cancer Cells but Not in Normal Fibroblast Cells

PubMed Central

Nishikawa, Yukihiro; Okuzaki, Daisuke; Fukushima, Kohshiro; Mukai, Satomi; Ohno, Shouichi; Ozaki, Yuki; Yabuta, Norikazu; Nojima, Hiroshi

2015-01-01

Withaferin A (WA), a major bioactive component of the Indian herb Withania somnifera, induces cell death (apoptosis/necrosis) in multiple types of tumor cells, but the molecular mechanism underlying this cytotoxicity remains elusive. We report here that 2 μM WA induced cell death selectively in androgen-insensitive PC-3 and DU-145 prostate adenocarcinoma cells, whereas its toxicity was less severe in androgen-sensitive LNCaP prostate adenocarcinoma cells and normal human fibroblasts (TIG-1 and KD). WA also killed PC-3 cells in spheroid-forming medium. DNA microarray analysis revealed that WA significantly increased mRNA levels of c-Fos and 11 heat-shock proteins (HSPs) in PC-3 and DU-145, but not in LNCaP and TIG-1. Western analysis revealed increased expression of c-Fos and reduced expression of the anti-apoptotic protein c-FLIP(L). Expression of HSPs such as HSPA6 and Hsp70 was conspicuously elevated; however, because siRNA-mediated depletion of HSF-1, an HSP-inducing transcription factor, reduced PC-3 cell viability, it is likely that these heat-shock genes were involved in protecting against cell death. Moreover, WA induced generation of reactive oxygen species (ROS) in PC-3 and DU-145, but not in normal fibroblasts. Immunocytochemistry and immuno-electron microscopy revealed that WA disrupted the vimentin cytoskeleton, possibly inducing the ROS generation, c-Fos expression and c-FLIP(L) suppression. These observations suggest that multiple events followed by disruption of the vimentin cytoskeleton play pivotal roles in WA-mediated cell death. PMID:26230090

Impact of Circulating Cholesterol Levels on Growth and Intratumoral Androgen Concentration of Prostate Tumors

PubMed Central

Pelton, Kristine; Freeman, Michael R.; Montgomery, R. Bruce

2012-01-01

Prostate cancer (PCa) is the second most common cancer in men. Androgen deprivation therapy (ADT) leads to tumor involution and reduction of tumor burden. However, tumors eventually reemerge that have overcome the absence of gonadal androgens, termed castration resistant PCa (CRPC). Theories underlying the development of CRPC include androgen receptor (AR) mutation allowing for promiscuous activation by non-androgens, AR amplification and overexpression leading to hypersensitivity to low androgen levels, and/or tumoral uptake and conversion of adrenally derived androgens. More recently it has been proposed that prostate tumor cells synthesize their own androgens through de novo steroidogenesis, which involves the step-wise synthesis of androgens from cholesterol. Using the in vivo LNCaP PCa xenograft model, previous data from our group demonstrated that a hypercholesterolemia diet potentiates prostatic tumor growth via induction of angiogenesis. Using this same model we now demonstrate that circulating cholesterol levels are significantly associated with tumor size (R = 0.3957, p = 0.0049) and intratumoral levels of testosterone (R = 0.41, p = 0.0023) in LNCaP tumors grown in hormonally intact mice. We demonstrate tumoral expression of cholesterol uptake genes as well as the spectrum of steroidogenic enzymes necessary for androgen biosynthesis from cholesterol. Moreover, we show that circulating cholesterol levels are directly correlated with tumoral expression of CYP17A, the critical enzyme required for de novo synthesis of androgens from cholesterol (R = 0.4073, p = 0.025) Since hypercholesterolemia does not raise circulating androgen levels and the adrenal gland of the mouse synthesizes minimal androgens, this study provides evidence that hypercholesterolemia increases intratumoral de novo steroidogenesis. Our results are consistent with the hypothesis that cholesterol-fueled intratumoral androgen synthesis may accelerate the growth of prostate tumors, and suggest that treatment of CRPC may be optimized by inclusion of cholesterol reduction therapies in conjunction with therapies targeting androgen synthesis and the AR. PMID:22279565

Nucleoporin 62 and Ca(2+)/calmodulin dependent kinase kinase 2 regulate androgen receptor activity in castrate resistant prostate cancer cells.

PubMed

Karacosta, Loukia G; Kuroski, Laura A; Hofmann, Wilma A; Azabdaftari, Gissou; Mastri, Michalis; Gocher, Angela M; Dai, Shuhang; Hoste, Allen J; Edelman, Arthur M

2016-02-15

Re-activation of the transcriptional activity of the androgen receptor (AR) is an important factor mediating progression from androgen-responsive to castrate-resistant prostate cancer (CRPC). However, the mechanisms regulating AR activity in CRPC remain incompletely understood. Ca(2+) /calmodulin-dependent kinase kinase (CaMKK) 2 was previously shown to regulate AR activity in androgen-responsive prostate cancer cells. Our objective was to further explore the basis of this regulation in CRPC cells. The abundance of CaMKK2 in nuclear fractions of androgen-responsive prostate cancer and CRPC, cells were determined by subcellular fractionation and Western blotting. CaMKK2 association with nuclear pore complexes (NPCs) and nucleoporins (Nups) including Nup62, were imaged by structured illumination and super-resolution fluorescence microscopy and co-immunoprecipitation, respectively. The abundance and subcellular localization of CaMKK2 and Nup62 in human clinical specimens of prostate cancer was visualized by immunohistochemistry. The role of Nups in the growth and viability of CRPC cells was assessed by RNA interference and cell counting. The involvement of CaMKK2 and Nup62 in regulating AR transcriptional activity was addressed by RNA interference, chromatin immunoprecipitation, androgen response element reporter assay, and Western blotting. CaMKK2 was expressed at higher levels in the nuclear fraction of CPRC C4-2 cells, than in that of androgen-responsive LNCaP cells. In C4-2 cells, CaMKK2 associated with NPCs of the nuclear envelope and physically interacted with Nup62. CaMKK2 and Nup62 demonstrated pronounced, and similar increases in both expression and perinuclear/nuclear localization in human clinical specimens of advanced prostate cancer relative to normal prostate. Knockdown of Nup62, but not of Nups, 98 or 88, reduced growth and viability of C4-2 cells. Knockdown of Nup62 produced a greater reduction of the growth and viability of C4-2 cells than of non-neoplastic RWPE-1 prostatic cells. Nup62, CaMKK2, and the AR were recruited to androgen response elements of the AR target genes, prostate specific antigen, and transmembrane protease, serine 2. Knockdown of CaMKK2 and Nup62 reduced prostate specific antigen expression and AR transcriptional activity driven by androgen response elements from the prostate-specific probasin gene promoter. Nup62 and CaMKK2 are required for optimal AR transcriptional activity and a potential mechanism for AR re-activation in CRPC. © 2015 Wiley Periodicals, Inc.

Gamma-glutamyltransferase activity in exosomes as a potential marker for prostate cancer.

PubMed

Kawakami, Kyojiro; Fujita, Yasunori; Matsuda, Yoko; Arai, Tomio; Horie, Kengo; Kameyama, Koji; Kato, Taku; Masunaga, Koichi; Kasuya, Yutaka; Tanaka, Masashi; Mizutani, Kosuke; Deguchi, Takashi; Ito, Masafumi

2017-05-05

Exosomes or extracellular vesicles have the potential as a diagnostic marker for various diseases including cancer. In order to identify novel exosomal markers for prostate cancer (PC), we performed proteomic analysis of exosomes isolated from PC cell lines and examined the usefulness of the marker in patients. Exosomes isolated by differential centrifugation from the culture medium of androgen-dependent LNCaP prostate cancer cell line and its sublines of partially androgen-independent C4, androgen-independent C4-2 and bone metastatic C4-2B were subjected to iTRAQ-based proteomic analysis. Exosomes were also isolated by immunocapture and separated by size exclusion chromatography and density gradient centrifugation. Protein expression was determined by Western blot analysis. GGT activity was measured using a fluorescent probe, γ-glutamyl hydroxymethyl rhodamine green (gGlu-HMRG). Immunohistochemical analysis of tissues was performed using anti-GGT1 antibody. Among proteins upregulated in C4-2 and C4-2B cells than in LNCaP cells, we focused on gamma-glutamyltransferase 1 (GGT1), a cell-surface enzyme that regulates the catabolism of extracellular glutathione. The levels of both GGT1 large and small subunits were elevated in exosomes isolated from C4-2 and C4-2B cells by differential centrifugation and by immunocapture with anti-CD9 or -prostate-specific membrane antigen (PSMA) antibody. In cell lysates and exosomes, GGT1 expression correlated with GGT activity. Size exclusion chromatography of human serum demonstrated the presence of GGT activity and GGT1 subunits in fractions positive for CD9. Density gradient centrifugation revealed the co-presence of GGT1 subunits with CD9 in exosomes isolated by differential centrifugation from human serum. Since GGT activity correlated with GGT1 expression in serum exosomes isolated by differential centrifugation, we measured serum exosomal GGT activity in patients. Unexpectedly, we found that serum exosomal GGT activity was significantly higher in PC patients than in benign prostatic hyperplasia (BPH) patients. In support of this finding, immunohistochemical analysis showed increased GGT1 expression in PC tissues compared with BPH tissues. Our results suggest that serum exosomal GGT activity could be a useful biomarker for PC.

Regulation of androgen receptor transactivity and mTOR-S6 kinase pathway by Rheb in prostate cancer cell proliferation.

PubMed

Kobayashi, Takashi; Shimizu, Yosuke; Terada, Naoki; Yamasaki, Toshinari; Nakamura, Eijiro; Toda, Yoshinobu; Nishiyama, Hiroyuki; Kamoto, Toshiyuki; Ogawa, Osamu; Inoue, Takahiro

2010-06-01

Ras homolog-enriched in brain (Rheb), a small GTP-binding protein, is associated with prostate carcinogenesis through activating mammalian target of rapamycin (mTOR) signaling pathway. This study aimed to elucidate whether Rheb promotes proliferation of prostate cancer cells and can act as a potent therapeutic target in prostate cancer. Prostate cancer cell lines and human prostatic tissues were examined for the expression of Rheb. The effects of forced expression or knockdown of Rheb on cell proliferation were also examined. Semi-quantitative and quantitative RT-PCR were performed to evaluate mRNA expression. Western blotting was used to examine protein expression. Cell count and WST-1 assay were used to measure cell proliferation. Fluorescence-activated cell sorting was used to assess the cell cycle. Rheb mRNA and protein expression was higher in more aggressive, androgen-independent prostate cancer cell lines PC3, DU145, and C4-2, compared with the less aggressive LNCaP. Rheb expression was higher in cancer tissues than in benign prostatic epithelia. Forced expression of Rheb in LNCaP cells accelerated proliferation without enhancing androgen receptor transactivity. Attenuation of Rheb expression or treatment with the mTOR inhibitor rapamycin decreased proliferation of PC3 and DU145 cells, with a decrease in the activated form of p70S6 kinase, one of the main targets of mTOR. Rheb potentiates proliferation of prostate cancer cells and inhibition of Rheb or mTOR can lead to suppressed proliferation of aggressive prostate cancer cell lines in vitro. Rheb and the mTOR pathway are therefore probable targets for suppressing prostate cancer.

The pluripotency factor Nanog is directly upregulated by the androgen receptor in prostate cancer cells.

PubMed

Kregel, Steven; Szmulewitz, Russell Z; Vander Griend, Donald J

2014-11-01

The Androgen Receptor (AR) is a nuclear hormone receptor that functions as a critical oncogene in all stages of prostate cancer progression, including progression to castration-resistance following androgen-deprivation therapy. Thus, identifying and targeting critical AR-regulated genes is one potential method to block castration-resistant cancer proliferation. Of particular importance are transcription factors that regulate stem cell pluripotency; many of these genes are emerging as critical oncogenes in numerous tumor cell types. Of these, Nanog has been previously shown to increase the self-renewal and stem-like properties of prostate cancer cells. Thus, we hypothesized that Nanog is a candidate AR target gene that may impart castration-resistance. We modulated AR signaling in LNCaP prostate cancer cells and assayed for Nanog expression. Direct AR binding to the NANOG promoter was tested using AR Chromatin Immunoprecipation (ChIP) and analyses of publically available AR ChIP-sequencing data-sets. Nanog over-expressing cells were analyzed for cell growth and cytotoxicity in response to the AR antagonist enzalutamide and the microtubule stabilizing agent docetaxel. AR signaling upregulates Nanog mRNA and protein. AR binds directly to the NANOG promoter, and was not identified within 75 kb of the NANOGP8 pseudogene, suggesting the NANOG gene locus was preferentially activated. Nanog overexpression in LNCaP cells increases overall growth, but does not increase resistance to enzalutamide or docetaxel. Nanog is a novel oncogenic AR target gene in prostate cancer cells, and stable expression of Nanog increases proliferation and growth of prostate cancer cells, but not resistance to enzalutamide or docetaxel. © 2014 Wiley Periodicals, Inc.

TBECH, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane, alters androgen receptor regulation in response to mutations associated with prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kharlyngdoh, Joubert Banjop; Asnake, Solomon; Prad

Point mutations in the AR ligand-binding domain (LBD) can result in altered AR structures leading to changes of ligand specificity and functions. AR mutations associated to prostate cancer (PCa) have been shown to result in receptor activation by non-androgenic substances and anti-androgenic drugs. Two AR mutations known to alter the function of anti-androgens are the AR{sub T877A} mutation, which is frequently detected mutation in PCa tumors and the AR{sub W741C} that is rare and has been derived in vitro following exposure of cells to the anti-androgen bicalutamide. AR activation by non-androgenic environmental substances has been suggested to affect PCa progression.more » In the present study we investigated the effect of AR mutations (AR{sub W741C} and AR{sub T877A}) on the transcriptional activation following exposure of cells to an androgenic brominated flame retardant, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane (TBECH, also named DBE-DBCH). The AR mutations resulted in higher interaction energies and increased transcriptional activation in response to TBECH diastereomer exposures. The AR{sub T877A} mutation rendered AR highly responsive to low levels of DHT and TBECH and led to increased AR nuclear translocation. Gene expression analysis showed a stronger induction of AR target genes in LNCaP cells (AR{sub T877A}) compared to T-47D cells (AR{sub WT}) following TBECH exposure. Furthermore, AR knockdown experiments confirmed the AR dependency of these responses. The higher sensitivity of AR{sub T877A} and AR{sub W741C} to low levels of TBECH suggests that cells with these AR mutations are more susceptible to androgenic endocrine disrupters. - Highlights: • TBECH, is an endocrine disrupting compound that differ in activity depending on AR structure and sequence. • TBECH interaction with the human AR-LBD containing the mutations W741C and T877A is increased compared to the wild type receptor • The mutations, W741C and T877A, are more potent than the wild type receptor at inducing AR nuclear translocation and transcriptional activation following TBECH exposure. • TBECH mediates action on androgen response genes via AR signaling.« less

Inactivation of ID4 promotes a CRPC phenotype with constitutive AR activation through FKBP52.

PubMed

Joshi, Jugal Bharat; Patel, Divya; Morton, Derrick J; Sharma, Pankaj; Zou, Jin; Hewa Bostanthirige, Dhanushka; Gorantla, Yamini; Nagappan, Peri; Komaragiri, Shravan Kumar; Sivils, Jeffrey C; Xie, Huan; Palaniappan, Ravi; Wang, Guangdi; Cox, Marc B; Chaudhary, Jaideep

2017-04-01

Castration-resistant prostate cancer (CRPC) is the emergence of prostate cancer cells that have adapted to the androgen-depleted environment of the prostate. In recent years, targeting multiple chaperones and co-chaperones (e.g., Hsp27, FKBP52) that promote androgen receptor (AR) signaling and/or novel AR regulatory mechanisms have emerged as promising alternative treatments for CRPC. We have shown that inactivation of inhibitor of differentiation 4 (ID4), a dominant-negative helix loop helix protein, promotes de novo steroidogenesis and CRPC with a gene expression signature that resembles constitutive AR activity in castrated mice. In this study, we investigated the underlying mechanism through which loss of ID4 potentiates AR signaling. Proteomic analysis between prostate cancer cell line LNCaP (L+ns) and LNCaP lacking ID4 (L(-)ID4) revealed elevated levels of Hsp27 and FKBP52, suggesting a role for these AR-associated co-chaperones in promoting constitutively active AR signaling in L(-)ID4 cells. Interestingly, protein interaction studies demonstrated a direct interaction between ID4 and the 52-kDa FK506-binding protein (FKBP52) in vitro, but not with AR. An increase in FKBP52-dependent AR transcriptional activity was observed in L(-)ID4 cells. Moreover, pharmacological inhibition of FKBP52-AR signaling, by treatment with MJC13, attenuated the tumor growth, weight, and volume in L(-)ID4 xenografts. Together, our results demonstrate that ID4 selectively regulates AR activity through direct interaction with FKBP52, and its loss, promotes CRPC through FKBP52-mediated AR signaling. © 2016 The Authors. Published by FEBS Press and John Wiley & Sons Ltd.

Effect of the heat shock protein HSP27 on androgen receptor expression and function in prostate cancer cells.

PubMed

Stope, Matthias B; Schubert, Tina; Staar, Doreen; Rönnau, Cindy; Streitbörger, Andreas; Kroeger, Nils; Kubisch, Constanze; Zimmermann, Uwe; Walther, Reinhard; Burchardt, Martin

2012-06-01

Heat shock proteins (HSP) are involved in processes of folding, activation, trafficking and transcriptional activity of most steroid receptors including the androgen receptor (AR). Accumulating evidence links rising heat shock protein 27 (HSP27) levels with the development of castration-resistant prostate cancer. In order to study the functional relationship between HSP27 and the AR, we modulated the expression of the small heat shock protein HSP27 in human prostate cancer (PC) cell lines. HSP27 protein concentrations in LNCaP and PC-3 cells were modulated by over-expression or silencing of HSP27. The effects of HSP27 on AR protein and mRNA levels were monitored by Western blotting and quantitative RT-PCR. Treatment for the AR-positive LNCaP with HSP27-specific siRNA resulted in a down-regulation of AR levels. This down-regulation of protein was paralleled by a decrease in AR mRNA. Most interestingly, over-expression of HSP27 in PC-3 cells led to a significant increase in AR mRNA although the cells were unable to produce functional AR protein. The observation that HSP27 is involved in the regulation of AR mRNA by a yet unknown mechanism highlights the complexity of HSP27-AR signaling network.

Withanolides from Aeroponically Grown Physalis peruviana and Their Selective Cytotoxicity to Prostate Cancer and Renal Carcinoma Cells.

PubMed

Xu, Ya-Ming; Wijeratne, E M Kithsiri; Babyak, Ashley L; Marks, Hanna R; Brooks, Alan D; Tewary, Poonam; Xuan, Li-Jiang; Wang, Wen-Qiong; Sayers, Thomas J; Gunatilaka, A A Leslie

2017-07-28

Investigation of aeroponically grown Physalis peruviana resulted in the isolation of 11 new withanolides, including perulactones I-L (1-4), 17-deoxy-23β-hydroxywithanolide E (5), 23β-hydroxywithanolide E (6), 4-deoxyphyperunolide A (7), 7β-hydroxywithanolide F (8), 7β-hydroxy-17-epi-withanolide K (9), 24,25-dihydro-23β,28-dihydroxywithanolide G (10), and 24,25-dihydrowithanolide E (11), together with 14 known withanolides (12-25). The structures of 1-11 were elucidated by the analysis of their spectroscopic data, and 12-25 were identified by comparison of their spectroscopic data with those reported. All withanolides were evaluated for their cytotoxic activity against a panel of tumor cell lines including LNCaP (androgen-sensitive human prostate adenocarcinoma), 22Rv1 (androgen-resistant human prostate adenocarcinoma), ACHN (human renal adenocarcinoma), M14 (human melanoma), SK-MEL-28 (human melanoma), and normal human foreskin fibroblast cells. Of these, the 17β-hydroxywithanolides (17-BHWs) 6, 8, 9, 11-13, 15, and 19-22 showed selective cytotoxic activity against the two prostate cancer cell lines LNCaP and 22Rv1, whereas 13 and 20 exhibited selective toxicity for the ACHN renal carcinoma cell line. These cytotoxicity data provide additional structure-activity relationship information for the 17-BHWs.

TAF1, From a General Transcription Factor to Modulator of Androgen Receptor in Prostate Cancer

DTIC Science & Technology

2008-02-01

or pARR3tk-Luc), and the Renilla luciferase vector (pRL-TK) as an internal control. Cells were then treated with or without R1881 for 24 h prior to...increasing amount of HA tagged full length TAF1 (pCS2+/TAF1), pRL-TK- Renilla (83 ng/well), and pARR3-tk-Luc (167 ng/well) (A) or pPSA-Luc (1ug/well...numbers of pRL-TK- Renilla , as a non androgenic reporter was also enhanced by TAF1 over-expression in both LNCaP and PC3 cells, the ARR3tk-Luc

TOFA (5-tetradecyl-oxy-2-furoic acid) reduces fatty acid synthesis, inhibits expression of AR, neuropilin-1 and Mcl-1 and kills prostate cancer cells independent of p53 status.

PubMed

Guseva, Natalya V; Rokhlin, Oskar W; Glover, Rebecca A; Cohen, Michael B

2011-07-01

A key player in prostate cancer development and progression is the androgen receptor (AR). Tumor-associated lipogenesis can protect cancer cells from carcinogenic- and therapeutic-associated treatments. Increased synthesis of fatty acids and cholesterol is regulated by androgens through induction of several genes in androgen-responsive cancer cells. Acetyl-CoA-carboxylase-α (ACCA) is a key enzyme in the regulation of fatty acids synthesis. Here we show that AR binds in vivo to intron regions of human ACCA gene. We also show that the level of ACCA protein in LNCaP depends on AR expression and that DHT treatment increases ACCA expression and fatty acid synthesis. Inhibition of ACCA by TOFA (5-tetradecyl-oxy-2-furoic acid) decreases fatty acid synthesis and induces caspase activation and cell death in most PCa cell lines. Our data suggest that TOFA can kill cells via the mitochondrial pathway since we found cytochrome c release after TOFA treatment in androgen sensitive cell lines. The results also imply that the pro-apoptotic effect of TOFA may be mediated via a decrease of neuropilin-1(NRP1) and Mcl-1expression. We have previously reported that Mcl-1 is under AR regulation and plays an important role in resistance to drug-induced apoptosis in prostate cancer cells, and NRP1 is known to regulate Mcl-1 expression. Here, we show for the first time that NRP1 expression is under AR control. Taken together, our data suggest that TOFA is a potent cell death inducing agent in prostate cancer cells.

URI Regulation of Androgen Receptor-Mediated Cell Growth

DTIC Science & Technology

2013-07-01

R2TP/ Prefoldin -like cochaperone are involved in the cytoplasmic assembly of RNA polymerase II . Mol Cell 39, 912- 924. Chen, C.D., Welsbie, D.S., Tran...primers specific for the promoter of the chosen genes II . Test and titrate antibodies against the identified transcription factors in immuno...LNCaP prostate cancer cells ii . Measure KAP1 target gene expression changes (NOXA, p21, BAX) upon siRNA knockdown of ART-27 in LNCaP cells We

Dissecting the expression of EEF1A1/2 genes in human prostate cancer cells: the potential of EEF1A2 as a hallmark for prostate transformation and progression.

PubMed

Scaggiante, B; Dapas, B; Bonin, S; Grassi, M; Zennaro, C; Farra, R; Cristiano, L; Siracusano, S; Zanconati, F; Giansante, C; Grassi, G

2012-01-03

In prostate adenocarcinoma, the dissection of the expression behaviour of the eukaryotic elongation factors (eEF1A1/2) has not yet fully elucidated. The EEF1A1/A2 expressions were investigated by real-time PCR, western blotting (cytoplasmic and cytoskeletal/nuclear-enriched fractions) and immunofluorescence in the androgen-responsive LNCaP and the non-responsive DU-145 and PC-3 cells, displaying a low, moderate and high aggressive phenotype, respectively. Targeted experiments were also conducted in the androgen-responsive 22Rv1, a cell line marking the progression towards androgen-refractory tumour. The non-tumourigenic prostate PZHPV-7 cell line was the control. Compared with PZHPV-7, cancer cells showed no major variations in EEF1A1 mRNA; eEF1A1 protein increased only in cytoskeletal/nuclear fraction. On the contrary, a significant rise of EEF1A2 mRNA and protein were found, with the highest levels detected in LNCaP. Eukaryotic elongation factor 1A2 immunostaining confirmed the western blotting results. Pilot evaluation in archive prostate tissues showed the presence of EEF1A2 mRNA in near all neoplastic and perineoplastic but not in normal samples or in benign adenoma; in contrast, EEF1A1 mRNA was everywhere detectable. Eukaryotic elongation factor 1A2 switch-on, observed in cultured tumour prostate cells and in human prostate tumour samples, may represent a feature of prostate cancer; in contrast, a minor involvement is assigned to EEF1A1. These observations suggest to consider EEF1A2 as a marker for prostate cell transformation and/or possibly as a hallmark of cancer progression.

The ErbB family and androgen receptor signaling are targets of Celecoxib in prostate cancer.

PubMed

Brizzolara, Antonella; Benelli, Roberto; Venè, Roberta; Barboro, Paola; Poggi, Alessandro; Tosetti, Francesca; Ferrari, Nicoletta

2017-08-01

Inflammation plays a central role in prostate cancer (PCa) development through significant crosstalk between the COX-2-ErbB family receptor network and androgen receptor (AR)-EGFR signaling pathways. The purpose of this work was to determine the ability of the COX-2 inhibitor Celecoxib to modulate the EGFR-AR signaling pathway in androgen-dependent PCa cells and to provide a rationale for its beneficial use in chemopreventive strategies. Functional studies of Celecoxib activity were performed on LNCaP prostate cancer cells. Western blotting, gene expression analysis, dual-luciferase reporter assay and ELISA were applied to assess the Celecoxib mechanisms of action. We found that Celecoxib, through EGF and amphiregulin (AREG) induction, caused EGFR and ErbB2 activation and consequent degradation associated with the inhibition of androgenic signaling. By upregulating the E3 ubiquitin ligase Nrdp1, Celecoxib also efficiently downregulated ErbB3, which is strongly implicated in castration-resistant prostate cancer. Lastly, Celecoxib directly regulated AR transcription and translation independent of ErbB activation by downregulating the RNA binding protein heterogeneous nuclear ribonucleoprotein K (hnRNP K). The simultaneous suppression of ErbB kinases and androgen signaling by Celecoxib represents a novel strategy to interrupt the vicious cycle of AR/ErbB cross-talk with the primary purpose of undermining their resilient signaling in prostate cancer progression. Our data provide important premises for the chemopreventive use of Celecoxib in the clinical management of prostate cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of increased choline compounds with proton nuclear magnetic resonance spectroscopy subsequent to malignant transformation of human prostatic epithelial cells.

PubMed

Ackerstaff, E; Pflug, B R; Nelson, J B; Bhujwalla, Z M

2001-05-01

In this study, a panel of normal human prostate cells (HPCs) and tumor cells derived from metastases were studied by (1)H NMR spectroscopy to determine whether the malignant transformation of HPCs results in the elevation of choline compounds. Although an elevated choline signal has been observed previously in clinical studies, the contribution of the different Cho compounds to this elevation, as well as their quantification, has not been established until now. Here we have shown that HPCs derived from metastases exhibit significantly higher phosphocholine as well as glycerophosphocholine levels compared with normal prostate epithelial and stromal cells. Thus the elevation of the choline peak observed clinically in prostate cancer is attributable to an alteration of phospholipid metabolism and not simply to increased cell density, doubling time, or other nonspecific effects. Androgen deprivation of the androgen receptor-positive cell lines resulted in a significant increase of choline compounds after chronic androgen deprivation of the LNCaP cell line and in a decrease of choline compounds after a more acute androgen deprivation of the LAPC-4 cell line. These data strongly support the use of proton magnetic resonance spectroscopic imaging to detect the presence of prostate cancer for diagnosis, to detect response subsequent to androgen ablation therapy, and to detect recurrence.

MUC1-C ONCOPROTEIN CONFERS ANDROGEN-INDEPENDENT GROWTH OF HUMAN PROSTATE CANCER CELLS

PubMed Central

Rajabi, Hasan; Ahmad, Rehan; Jin, Caining; Joshi, Maya Datt; Guha, Minakshi; Alam, Maroof; Kharbanda, Surender; Kufe, Donald

2012-01-01

Background The mucin 1 (MUC1) heterodimeric oncoprotein is overexpressed in human prostate cancers with aggressive pathologic and clinical features. However, few insights are available regarding the functional role of MUC1 in prostate cancer. Methods Effects of MUC1-C on AR expression were determined by RT-PCR, immunoblotting and AR promoter activation. Coimmunoprecipitations, direct binding assays and chromatin immunoprecipitation (ChIP) studies were performed to assess the interaction between MUC1-C and AR. Cells were analyzed for invasion, growth in androgen-depleted medium and sensitivity to MUC1-C inhibitors. Results The present studies in androgen-dependent LNCaP and LAPC4 prostate cancer cells demonstrate that the oncogenic MUC1-C subunit suppresses AR expression. The results show that MUC1-C activates a posttranscriptional mechanism involving miR-135b-mediated downregulation of AR mRNA levels. The results further demonstrate that MUC1-C forms a complex with AR through a direct interaction between the MUC1-C cytoplasmic domain and the AR DNA-binding domain. In addition, MUC1-C associates with AR in a complex that occupies the PSA promoter. The interaction between MUC1-C and AR is associated with induction of the epithelial-mesenchymal transition (EMT) and increased invasion. MUC1-C also conferred growth in androgen-depleted medium and resistance to bicalutamide treatment. Moreover, expression of MUC1-C resulted in sensitivity to the MUC1-C inhibitor GO-203 with inhibition of growth in vitro. GO-203 treatment also inhibited growth of established tumor xenografts in nude mice. Conclusions These findings indicate that MUC1-C suppresses AR expression in prostate cancer cells and confers a more aggressive androgen-independent phenotype that is sensitive to MUC1-C inhibition. PMID:22473899

Therapeutic targeting of angiotensin II receptor type 1 to regulate androgen receptor in prostate cancer.

PubMed

Takahashi, Satoru; Uemura, Hiroji; Seeni, Azman; Tang, Mingxi; Komiya, Masami; Long, Ne; Ishiguro, Hitoshi; Kubota, Yoshinobu; Shirai, Tomoyuki

2012-10-01

With the limited strategies for curative treatment of castration-resistant prostate cancer (CRPC), public interest has focused on the potential prevention of prostate cancer. Recent studies have demonstrated that an angiotensin II receptor blocker (ARB) has the potential to decrease serum prostate-specific antigen (PSA) level and improve performance status in CRPC patients. These facts prompted us to investigate the direct effects of ARBs on prostate cancer growth and progression. Transgenic rat for adenocarcinoma of prostate (TRAP) model established in our laboratory was used. TRAP rats of 3 weeks of age received ARB (telmisartan or candesartan) at the concentration of 2 or 10 mg/kg/day in drinking water for 12 weeks. In vitro analyses for cell growth, ubiquitylation or reporter gene assay were performed using LNCaP cells. We found that both telmisartan and candesartan attenuated prostate carcinogenesis in TRAP rats by augmentation of apoptosis resulting from activation of caspases, inactivation of p38 MAPK and down-regulation of the androgen receptor (AR). Further, microarray analysis demonstrated up-regulation of estrogen receptor β (ERβ) by ARB treatment. In both parental and androgen-independent LNCaP cells, ARB inhibited both cell growth and AR-mediated transcriptional activity. ARB also exerted a mild additional effect on AR-mediated transcriptional activation by the ERβ up-regulation. An intervention study revealed that PSA progression was prolonged in prostate cancer patients given an ARB compared with placebo control. These data provide a new concept that ARBs are promising potential chemopreventive and chemotherapeutic agents for prostate cancer. Copyright © 2012 Wiley Periodicals, Inc.

A role for SIRT1 in cell growth and chemoresistance in prostate cancer PC3 and DU145 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kojima, Keitaro; Department of Longevity and Aging Research, Gifu International Institute of Biotechnology, 1-1 Naka-fudogaoka, Kakamigahara, Gifu 504-0838; Ohhashi, Riyako

2008-08-29

SIRT1, which belongs to the family of type III histone deacetylase, is implicated in diverse cellular processes. We have determined the expression levels of SIRT1 in human prostate cancer cell lines and have examined the roles of SIRT1 in cell growth and chemoresistance. SIRT1 expression was markedly up-regulated in androgen-refractory PC3 and DU145 cells compared with androgen-sensitive LNCaP cells and its expression level was correlated with cell growth in PC3 cells. Treatment with a SIRT1 inhibitor, sirtinol, inhibited cell growth and increased sensitivity to camptothecin and cisplatin. Silencing of SIRT1 expression by siRNA also suppressed cell proliferation and reduced camptothecinmore » resistance in PC3 cells, mimicking the chemosensitizing effect caused by sirtinol. Also in DU145 cells, sirtinol treatment enhanced sensitivity to camptothecin and cisplatin. These results suggest that up-regulation of SIRT1 expression may play an important role in promoting cell growth and chemoresistance in androgen-refractory PC3 and DU145 cells.« less

CWR22: the first human prostate cancer xenograft with strongly androgen-dependent and relapsed strains both in vivo and in soft agar.

PubMed

Nagabhushan, M; Miller, C M; Pretlow, T P; Giaconia, J M; Edgehouse, N L; Schwartz, S; Kung, H J; de Vere White, R W; Gumerlock, P H; Resnick, M I; Amini, S B; Pretlow, T G

1996-07-01

Most patients' prostate cancers respond to androgen deprivation but relapse after periods of several months to years. Only two prostate cancer xenografts, LNCaP and PC-346, have been reported to be responsive to androgen deprivation and to relapse subsequently. Both of these tumors shrink slightly, if at all, and relapse less than 5 weeks after androgen withdrawal. After androgen withdrawal, the human primary prostate cancer xenograft CWR22 regresses markedly, and prostate-specific antigen (PSA) falls up to 3000-fold in the blood of mice. PSA usually returns to normal. In some animals, the tumor relapses and is then designated CWR22R. In these animals, PSA starts to rise approximately 2-7 months, and tumor begins to grow 3-10 months after castration. Animals with CWR22 need to be euthanized because of large tumors 6-12 weeks after the transplantation of CWR22. Androgen withdrawal prolongs life approximately 3-4-fold.

Amyloid precursor protein regulates migration and metalloproteinase gene expression in prostate cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyazaki, Toshiaki; Ikeda, Kazuhiro; Horie-Inoue, Kuniko

Highlights: • APP knockdown reduced proliferation and migration of prostate cancer cells. • APP knockdown reduced expression of metalloproteinase and EMT-related genes. • APP overexpression promoted LNCaP cell migration. • APP overexpression increased expression of metalloproteinase and EMT-related genes. - Abstract: Amyloid precursor protein (APP) is a type I transmembrane protein, and one of its processed forms, β-amyloid, is considered to play a central role in the development of Alzheimer’s disease. We previously showed that APP is a primary androgen-responsive gene in prostate cancer and that its increased expression is correlated with poor prognosis for patients with prostate cancer. APPmore » has also been implicated in several human malignancies. Nevertheless, the mechanism underlying the pro-proliferative effects of APP on cancers is still not well-understood. In the present study, we explored a pathophysiological role for APP in prostate cancer cells using siRNA targeting APP (siAPP). The proliferation and migration of LNCaP and DU145 prostate cancer cells were significantly suppressed by siAPP. Differentially expressed genes in siAPP-treated cells compared to control siRNA-treated cells were identified by microarray analysis. Notably, several metalloproteinase genes, such as ADAM10 and ADAM17, and epithelial–mesenchymal transition (EMT)-related genes, such as VIM, and SNAI2, were downregulated in siAPP-treated cells as compared to control cells. The expression of these genes was upregulated in LNCaP cells stably expressing APP when compared with control cells. APP-overexpressing LNCaP cells exhibited enhanced migration in comparison to control cells. These results suggest that APP may contribute to the proliferation and migration of prostate cancer cells by modulating the expression of metalloproteinase and EMT-related genes.« less

Activation of Hh Signaling: A Critical Biological Consequence of ETS Gene Anomalies in Prostate Cancer

DTIC Science & Technology

2013-01-01

CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18 . NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC a. REPORT U b. ABSTRACT U c. THIS...17 Reportable Outcomes……………………………………………………………… 18 Conclusion…………………………………………………………………………… 19 References...PSA (KLK3) KLK2 A B were derived from castration-relapse or metastatic xenografts of parental androgen-dependent PCa cell lines (LNCaP and CWR22

Silibinin phosphodiester glyco-conjugates: Synthesis, redox behaviour and biological investigations.

PubMed

Romanucci, Valeria; Agarwal, Chapla; Agarwal, Rajesh; Pannecouque, Christophe; Iuliano, Mauro; De Tommaso, Gaetano; Caruso, Tonino; Di Fabio, Giovanni; Zarrelli, Armando

2018-04-01

New silibinin phosphodiester glyco-conjugates were synthesized by efficient phosphoramidite chemistry and were fully characterized by 2D-NMR. A wide-ranging study focused on the determination of their pKa and E° values as well as on their radical scavenging activities by different assays (DPPH, ABTS + and HRSA) was conducted. The new glyco-conjugates are more water-soluble than silibinin, and their radical scavenging activities are higher than those of silibinin. The conjugation therefore improves both the water solubilities and antioxidant activities of the flavonolignan moieties. The serum stability was evaluated under physiological conditions, and the glyco-conjugates degraded with half-lives of 40-70 h, making them useful in pro-drug approaches. We started by treating androgen-dependent prostate cancer (PCa) LNCaP cells and then expanded our studies to androgen-independent PCa PC3 and DU145 cells. In most cases, the new derivatives significantly reduced both total and live cell numbers, albeit at different levels. Anti-HIV activities were evaluated and the glucosamine-phosphate silibinin derivative showed higher activity (IC 50  = 73 μM) than silibinin. Copyright © 2018 Elsevier Inc. All rights reserved.

Androgen receptor (AR) inhibitor ErbB3-binding protein-1 (Ebp1) is not targeted by the newly identified AR controlling signaling axis heat-shock protein HSP27 and microRNA miR-1 in prostate cancer cells.

PubMed

Stope, Matthias B; Peters, Stefanie; Großebrummel, Hannah; Zimmermann, Uwe; Walther, Reinhard; Burchardt, Martin

2015-03-01

Androgen receptor (AR) networks are predominantly involved in prostate cancer (PCa) progression; consequently, factors of AR regulation represent promising targets for PCa therapy. The ErbB3-binding protein 1 (Ebp1) is linked to AR suppression and chemoresistance by so far unknown mechanisms. In this study, an assumed regulation of Ebp1 by the newly identified AR controlling signaling axis heat-shock protein 27 (HSP27)-microRNA-1 (miR-1) was examined. Transfection experiments were carried out overexpressing and knockdown HSP27 and miR-1, respectively, in LNCaP and PC-3 cells. Afterward, HSP27- and miR-1-triggered Ebp1 protein expression was monitored by Western blotting. AR-positive LNCaP cells and AR-negative PC-3 cells possessed diverse basal expression levels of Ebp1. However, subsequent studies revealed no differences in cellular Ebp1 concentrations after modulation of HSP27 and miR-1. Furthermore, docetaxel incubation experiments exhibited no effects on Ebp1 protein synthesis. In PCa, Ebp1 has been described as a regulator of AR functionality and as an effector of PCa therapy resistance. Our data suggest that Ebp1 functionality is independent from heat-shock-protein-regulated progression networks in PCa.

FTY720 and (S)-FTY720 vinylphosphonate inhibit sphingosine kinase 1 and promote its proteasomal degradation in human pulmonary artery smooth muscle, breast cancer and androgen-independent prostate cancer cells

PubMed Central

Tonelli, Francesca; Lim, Keng Gat; Loveridge, Carolyn; Long, Jaclyn; Pitson, Stuart M.; Tigyi, Gabor; Bittman, Robert; Pyne, Susan; Pyne, Nigel J.

2010-01-01

Sphingosine kinase 1 (SK1) is an enzyme that catalyses the phosphorylation of sphingosine to produce the bioactive lipid sphingosine 1-phosphate (S1P). We demonstrate here that FTY720 (Fingolimod™) and (S)-FTY720 vinylphosphonate are novel inhibitors of SK1 catalytic activity and induce the proteasomal degradation of this enzyme in human pulmonary artery smooth muscle cells, MCF-7 breast cancer cells and androgen-independent LNCaP-AI prostate cancer cells. Proteasomal degradation of SK1 in response to FTY720 and (S)-FTY720 vinylphosphonate is associated with the down-regulation of the androgen receptor in LNCaP-AI cells. (S)-FTY720 vinylphosphonate also induces the apoptosis of these cells. These findings indicate that SK1 is involved in protecting LNCaP-AI from apoptosis. This protection might be mediated by so-called ‘inside-out’ signalling by S1P, as LNCaP-AI cells exhibit increased expression of S1P2/3 receptors and reduced lipid phosphate phosphatase expression (compared with androgen-sensitive LNCaP cells) thereby potentially increasing the bioavailability of S1P at S1P2/3 receptors. PMID:20570726

Discovery Proteomics Identifies a Molecular Link between the Coatomer Protein Complex I and Androgen Receptor-dependent Transcription*

PubMed Central

Hsiao, Jordy J.; Smits, Melinda M.; Ng, Brandon H.; Lee, Jinhee; Wright, Michael E.

2016-01-01

Aberrant androgen receptor (AR)-dependent transcription is a hallmark of human prostate cancers. At the molecular level, ligand-mediated AR activation is coordinated through spatial and temporal protein-protein interactions involving AR-interacting proteins, which we designate the “AR-interactome.” Despite many years of research, the ligand-sensitive protein complexes involved in ligand-mediated AR activation in prostate tumor cells have not been clearly defined. Here, we describe the development, characterization, and utilization of a novel human LNCaP prostate tumor cell line, N-AR, which stably expresses wild-type AR tagged at its N terminus with the streptavidin-binding peptide epitope (streptavidin-binding peptide-tagged wild-type androgen receptor; SBP-AR). A bioanalytical workflow involving streptavidin chromatography and label-free quantitative mass spectrometry was used to identify SBP-AR and associated ligand-sensitive cytosolic proteins/protein complexes linked to AR activation in prostate tumor cells. Functional studies verified that ligand-sensitive proteins identified in the proteomic screen encoded modulators of AR-mediated transcription, suggesting that these novel proteins were putative SBP-AR-interacting proteins in N-AR cells. This was supported by biochemical associations between recombinant SBP-AR and the ligand-sensitive coatomer protein complex I (COPI) retrograde trafficking complex in vitro. Extensive biochemical and molecular experiments showed that the COPI retrograde complex regulates ligand-mediated AR transcriptional activation, which correlated with the mobilization of the Golgi-localized ARA160 coactivator to the nuclear compartment of prostate tumor cells. Collectively, this study provides a bioanalytical strategy to validate the AR-interactome and define novel AR-interacting proteins involved in ligand-mediated AR activation in prostate tumor cells. Moreover, we describe a cellular system to study how compartment-specific AR-interacting proteins influence AR activation and contribute to aberrant AR-dependent transcription that underlies the majority of human prostate cancers. PMID:27365400

Direct Regulation of Androgen Receptor Activity by Potent CYP17 Inhibitors in Prostate Cancer Cells*

PubMed Central

Soifer, Harris S.; Souleimanian, Naira; Wu, Sijian; Voskresenskiy, Anatoliy M.; Kisaayak Collak, Filiz; Cinar, Bekir; Stein, Cy A.

2012-01-01

TOK-001 and abiraterone are potent 17-heteroarylsteroid (17-HAS) inhibitors of Cyp17, one of the rate-limiting enzymes in the biosynthesis of testosterone from cholesterol in prostate cancer cells. Nevertheless, the molecular mechanism underlying the prevention of prostate cell growth by 17-HASs still remains elusive. Here, we assess the effects of 17-HASs on androgen receptor (AR) activity in LNCaP and LAPC-4 cells. We demonstrate that both TOK-001 and abiraterone reduced AR protein and mRNA expression, and antagonized AR-dependent promoter activation induced by androgen. TOK-001, but not abiraterone, is an effective apparent competitor of the radioligand [3H]R1881 for binding to the wild type and various mutant AR (W741C, W741L) proteins. In agreement with these data, TOK-001 is a consistently superior inhibitor than abiraterone of R1881-induced transcriptional activity of both wild type and mutant AR. However, neither agent was able to trans-activate the AR in the absence of R1881. Our data demonstrate that phospho-4EBP1 levels are significantly reduced by TOK-001 and to a lesser extent by abiraterone alcohol, and suggest a mechanism by which cap-dependent translation is suppressed by blocking assembly of the eIF4F and eIF4G complex to the mRNA 5′ cap. Thus, the effects of these 17-HASs on AR signaling are complex, ranging from a decrease in testosterone production through the inhibition of Cyp17 as previously described, to directly reducing both AR protein expression and R1881-induced AR trans-activation. PMID:22174412

Novel mutations of androgen receptor: a possible mechanism of bicalutamide withdrawal syndrome.

PubMed

Hara, Takahito; Miyazaki, Jun-ichi; Araki, Hideo; Yamaoka, Masuo; Kanzaki, Naoyuki; Kusaka, Masami; Miyamoto, Masaomi

2003-01-01

Most prostate cancers (PCs) become resistant to combined androgen blockade therapy with surgical or medical castration and antiandrogens after several years. Some of these refractory PCs regress after discontinuation of antiandrogen administration [antiandrogen withdrawal syndrome (AWS)]. Although the molecular mechanisms of the AWS are not fully understood because of the lack of suitable experimental models, one hypothesis of the mechanism is mutation of androgen receptor (AR). However, bicalutamide, which has become the most prevalent pure antiandrogen, does not work as an agonist for any mutant AR detected thus far in PC. To elucidate the mechanisms of the AWS, we established and characterized novel LNCaP cell sublines, LNCaP-cxDs, which were generated in vitro by culturing androgen-dependent LNCaP-FGC human PC cells in androgen-depleted medium with bicalutamide to mimic the combined androgen blockade therapy. LNCaP-FGC cells did not grow at first, but they started to grow after 6-13 weeks of culture. Bicalutamide stimulated LNCaP-cxD cell growth and increased prostate-specific antigen secretion from LNCaP-cxD cells both in vitro and in vivo. Sequencing of AR transcripts revealed that the AR in LNCaP-cxD cells harbors a novel mutation in codon 741, TGG (tryptophan) to TGT (cysteine; W741C), or in codon 741, TGG to TTG (leucine; W741L), in the ligand-binding domain. Transactivation assays showed that bicalutamide worked as an agonist for both W741C and W741L mutant ARs. Importantly, another antiandrogen, hydroxyflutamide, worked as an antagonist for these mutant ARs. In summary, we demonstrate for the first time that within only 6-13 weeks of in vitro exposure to bicalutamide, LNCaP-FGC cells, whose growth had initially been suppressed, came to use bicalutamide as an AR agonist via W741 AR mutation to survive. Our data strongly support the hypothesis that AR mutation is one possible mechanism of the AWS and suggest that flutamide might be effective as a second-line therapy for refractory PC previously treated with bicalutamide.

A dual yet opposite growth-regulating function of miR-204 and its target XRN1 in prostate adenocarcinoma cells and neuroendocrine-like prostate cancer cells

PubMed Central

Ding, Miao; Lin, Biaoyang; Li, Tao; Liu, Yuanyuan; Li, Yuhua; Zhou, Xiaoyu; Miao, Maohua; Gu, Jinfa; Pan, Hongjie; Yang, Fen; Li, Tianqi; Liu, Xin Yuan; Li, Runsheng

2015-01-01

Androgen deprivation therapy in prostate cancer (PCa) causes neuroendocrine differentiation (NED) of prostatic adenocarcinomas (PAC) cells, leading to recurrence of PCa. Androgen-responsive genes involved in PCa progression including NED remain largely unknown. Here we demonstrated the importance of androgen receptor (AR)-microRNA-204 (miR-204)-XRN1 axis in PCa cell lines and the rat ventral prostate. Androgens downregulate miR-204, resulting in induction of XRN1 (5′-3′ exoribonuclease 1), which we identified as a miR-204 target. miR-204 acts as a tumor suppressor in two PAC cell lines (LNCaP and 22Rv1) and as an oncomiR in two neuroendocrine-like prostate cancer (NEPC) cell lines (PC-3 and CL1). Importantly, overexpression of miR-204 and knockdown of XRN1 inhibited AR expression in PCa cells. Repression of miR-34a, a known AR-targeting miRNA, contributes AR expression by XRN1. Thus we revealed the AR-miR-204-XRN1-miR-34a positive feedback loop and a dual function of miR-204/XRN1 axis in prostate cancer. PMID:25797256

De novo steroid biosynthesis in human prostate cell lines and biopsies.

PubMed

Sakai, Monica; Martinez-Arguelles, Daniel B; Aprikian, Armen G; Magliocco, Anthony M; Papadopoulos, Vassilios

2016-05-01

Intratumoral androgen formation may be a factor in the development of prostate cancer (PCa), particularly castration-resistant prostate cancer (CRPC). To evaluate the ability of the human prostate to synthesize de novo steroids, we examined the expression of key enzymes and proteins involved in steroid biosynthesis and metabolism. Using TissueScan™ Cancer qPCR Arrays and quantitative RT-PCR, we performed comparative gene expression analyses between various prostate cell lines and biopsies, including normal, hyperplastic, cancerous, and androgen-deprived prostate cells lines, as well as normal, benign prostate hyperplasia (BPH), PCa, and CRPC human specimens. These studies were complemented with steroid biosynthesis studies in normal and BPH cells. Normal human prostate WPMY-1 and WPE1-NA22, benign prostate hyperplasia BPH-1, and cancer PC-3, LNCaP, and VCaP cell lines, as well as normal, BPH, PCa, and CRPC specimens, were used. Although all cell lines express mRNA encoding for hydroxymethylglutaryl-CoA reductase (HMGCR), the mitochondrial translocator protein TSPO and cholesterol side chain cleavage enzyme CYP11A1 were only observed in WPMY-1, BPH-1, and LNCaP cells. HSD3B1, HSD3B2, and CYP17A1 are involved in androgen formation and were not found in most cell lines. WPE1-NA22 and BPH-1 cells were unable to synthesize de novo steroids from mevalonate. Moreover, androgen-deprived cells did not have alterations in the expression of enzymes that could lead to de novo steroid formation. All prostate specimens expressed TSPO and CYP11A1. HSD3B1/2, CYP17A1, HSD17B5, and CYP19A1 mRNA expression was distinct to the profile observed in cells lines. The majority of BPH (90.9%) and PCa (83.1%) specimens contained CYP17A1, compared to control (normal) specimens (46.7%). BPH (82%), PCa (59%), normal (40%), and CRPC (34%) specimens expressed the four key enzymes that metabolize cholesterol to androgens. These studies question the use of prostate cell lines to study steroid biosynthesis and demonstrate that human prostate samples contain transcripts encoding for key steroidogenic enzymes and proteins indicating that they have the potential to synthesize de novo steroids. We propose CYP17A1 as a candidate enzyme that can be used for patient stratification and treatment in BPH and PCa. © 2016 Wiley Periodicals, Inc.

Enhancement of Intermittent Androgen Ablation Therapy by Finasteride Administration in Animal Models

DTIC Science & Technology

2006-02-01

1-0113 TITLE: Enhancement of Intermittent Androgen Ablation Therapy by Finasteride Administration in Animal Models...To) 14 JAN 2002 - 13 JAN 2006 4. TITLE AND SUBTITLE Enhancement of Intermittent Androgen Ablation Therapy by Finasteride 5a. CONTRACT NUMBER... finasteride , an inhibitor of T to DHT conversion. We have tested our hypothesis using LNCaP xenograft tumors in nude mice. Our experiments showed

A synthetic decursin analog with increased in vivo stability suppresses androgen receptor signaling in vitro and in vivo.

PubMed

Zhang, Yong; Shaik, Ahmad Ali; Xing, Chengguo; Chai, Yubo; Li, Li; Zhang, Jinhui; Zhang, Wei; Kim, Sung-Hoon; Lü, Junxuan; Jiang, Cheng

2012-10-01

Targeting androgen receptor (AR) signaling with agents distinct from current antagonist drugs remains a rational approach to the prevention and treatment of prostate cancer (PCa). Our previous studies have shown that decursin and isomer decursinol angelate (DA), isolated from the Korean medicinal herb Angelica gigas Nakai, interrupt AR signaling and possess anti-PCa activities in vitro. In the LNCaP PCa cell model, these pyranoccoumarin compounds exhibit properties distinct from currently used antagonists (e.g., Casodex). However, both are rapidly de-esterified to decursinol, a partial AR agonist. We report here that a synthetic decursin analog, decursinol phenylthiocarbamate (DPTC), has greater in vivo stability than the parent compounds. DPTC-decursinol conversion was undetectable in mice. Furthermore, in LNCaP cells, DPTC decreased prostate specific antigen (PSA) expression, down-regulated AR abundance and mRNA and inhibited AR nuclear translocation. The effect of DPTC on AR and PSA mRNA and protein abundance was also observed in VCaP cells expressing wild type AR. DPTC inhibited growth of both PCa cell lines through G(1) cell cycle arrest and apoptosis, as did decursin and DA. Furthermore, i.p. administration of DPTC for 3 weeks suppressed the expression of AR target genes probasin and Nkx3.1 in mouse prostate glands. Overall, our data suggest that DPTC represents a prototype lead compound for development of in vivo stable and active novel decursin analogs for the prevention or therapy of PCa.

α-Santalol, a derivative of sandalwood oil, induces apoptosis in human prostate cancer cells by causing caspase-3 activation.

PubMed

Bommareddy, Ajay; Rule, Brittny; VanWert, Adam L; Santha, Sreevidya; Dwivedi, Chandradhar

2012-06-15

The anticancer effects of α-santalol, a major component of sandalwood oil, have been reported against the development of certain cancers such as skin cancer both in vitro and in vivo. The primary objectives of the current study were to investigate the cancer preventive properties of α-santalol on human prostate cancer cells PC-3 (androgen independent and P-53 null) and LNCaP (androgen dependent and P-53 wild-type), and determine the possible mechanisms of its action. The effect of α-santalol on cell viability was determined by trypan blue dye exclusion assay. Apoptosis induction was confirmed by analysis of cytoplasmic histone-associated DNA fragmentation using both an apoptotic ELISA kit and a DAPI fluorescence assay. Caspase-3 activity was determined using caspase-3 (active) ELISA kit. PARP cleavage was analyzed using immunoblotting. α-Santalol at 25-75 μM decreased cell viability in both cell lines in a concentration and time dependent manner. Treatment of prostate cancer cells with α-santalol resulted in induction of apoptosis as evidenced by DNA fragmentation and nuclear staining of apoptotic cells by DAPI. α-Santalol treatment also resulted in activation of caspase-3 activity and PARP cleavage. The α-santalol-induced apoptotic cell death and activation of caspase-3 was significantly attenuated in the presence of pharmacological inhibitors of caspase-8 and caspase-9. In conclusion, the present study reveals the apoptotic effects of α-santalol in inhibiting the growth of human prostate cancer cells. Copyright © 2012 Elsevier GmbH. All rights reserved.

MEIS1 functions as a potential AR negative regulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui, Liang; Department of Urology, Civil Aviation General Hospital/Civil Aviation Medical College of Peking University, Beijing 100123; Li, Mingyang

2014-10-15

The androgen receptor (AR) plays critical roles in human prostate carcinoma progression and transformation. However, the activation of AR is regulated by co-regulators. MEIS1 protein, the homeodomain transcription factor, exhibited a decreased level in poor-prognosis prostate tumors. In this study, we investigated a potential interaction between MEIS1 and AR. We found that overexpression of MEIS1 inhibited the AR transcriptional activity and reduced the expression of AR target gene. A potential protein–protein interaction between AR and MEIS1 was identified by the immunoprecipitation and GST pull-down assays. Furthermore, MEIS1 modulated AR cytoplasm/nucleus translocation and the recruitment to androgen response element in prostatemore » specific antigen (PSA) gene promoter sequences. In addition, MEIS1 promoted the recruitment of NCoR and SMRT in the presence of R1881. Finally, MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells. Taken together, our data suggests that MEIS1 functions as a novel AR co-repressor. - Highlights: • A potential interaction was identified between MEIS1 and AR signaling. • Overexpression of MEIS1 reduced the expression of AR target gene. • MEIS1 modulated AR cytoplasm/nucleus translocation. • MEIS1 inhibited the proliferation and anchor-independent growth of LNCaP cells.« less

Deregulation of miRNAs Contributes to Development and Progression of Prostate Cancer

DTIC Science & Technology

2011-09-01

blocking with 5% non- fat dry milk in Tris-buffered saline/0.05% Tween 20 (TBST), the membrane was incubated with a specific primary antibody...androgen R1881, and p53 protein was detected by Western blot analysis. Consistent with our previous observation (2), untreated LNCaP-R273H cells expressed...Cell Biochem 2009; 106(3): 363–371. 7 Appendices Figure 1. Western blot analysis of p53 protein in 5.0 nM R1881-treated LNCaP cells and LNCaP-R273H

Regulation of protein kinase C-related kinase (PRK) signalling by the TPα and TPβ isoforms of the human thromboxane A2 receptor: Implications for thromboxane- and androgen- dependent neoplastic and epigenetic responses in prostate cancer.

PubMed

O'Sullivan, Aine G; Mulvaney, Eamon P; Kinsella, B Therese

2017-04-01

The prostanoid thromboxane (TX) A 2 and its T Prostanoid receptor (the TP) are increasingly implicated in prostate cancer (PCa). Mechanistically, we recently discovered that both TPα and TPβ form functional signalling complexes with members of the protein kinase C-related kinase (PRK) family, AGC- kinases essential for the epigenetic regulation of androgen receptor (AR)-dependent transcription and promising therapeutic targets for treatment of castrate-resistant prostate cancer (CRPC). Critically, similar to androgens, activation of the PRKs through the TXA 2 /TP signalling axis induces phosphorylation of histone H3 at Thr11 (H3Thr11), a marker of androgen-induced chromatin remodelling and transcriptional activation, raising the possibility that TXA 2 -TP signalling can mimic and/or enhance AR-induced cellular changes even in the absence of circulating androgens such as in CRPC. Hence the aim of the current study was to investigate whether TXA 2 /TP-induced PRK activation can mimic and/or enhance AR-mediated cellular responses in the model androgen-responsive prostate adenocarcinoma LNCaP cell line. We reveal that TXA 2 /TP signalling can act as a neoplastic- and epigenetic-regulator, promoting and enhancing both AR-associated chromatin remodelling (H3Thr11 phosphorylation, WDR5 recruitment and acetylation of histone H4 at lysine 16) and AR-mediated transcriptional activation (e.g of the KLK3/prostate-specific antigen and TMPRSS2 genes) through mechanisms involving TPα/TPβ mediated-PRK1 and PRK2, but not PRK3, signalling complexes. Overall, these data demonstrate that TPα/TPβ can act as neoplastic and epigenetic regulators by mimicking and/or enhancing the actions of androgens within the prostate and provides further mechanistic insights into the role of the TXA 2 /TP signalling axis in PCa, including potentially in CRPC. Copyright © 2017 Elsevier B.V. All rights reserved.

Inhibitor of p52 NF-κB subunit and androgen receptor (AR) interaction reduces growth of human prostate cancer cells by abrogating nuclear translocation of p52 and phosphorylated ARser81

PubMed Central

Mehraein-Ghomi, Farideh; Church, Dawn R.; Schreiber, Cynthia L.; Weichmann, Ashley M.; Basu, Hirak S.; Wilding, George

2015-01-01

Accumulating evidence shows that androgen receptor (AR) activation and signaling plays a key role in growth and progression in all stages of prostate cancer, even under low androgen levels or in the absence of androgen in the castration-resistant prostate cancer. Sustained activation of AR under androgen-deprived conditions may be due to its interaction with co-activators, such as p52 NF-κB subunit, and/or an increase in its stability by phosphorylation that delays its degradation. Here we identified a specific inhibitor of AR/p52 interaction, AR/p52-02, via a high throughput screen based on the reconstitution of Gaussia Luciferase. We found that AR/p52-02 markedly inhibited growth of both castration-resistant C4-2 (IC50 ∼6 μM) and parental androgen-dependent LNCaP (IC50 ∼4 μM) human prostate cancer cells under low androgen conditions. Growth inhibition was associated with significantly reduced nuclear p52 levels and DNA binding activity, as well as decreased phosphorylation of AR at serine 81, increased AR ubiquitination, and decreased AR transcriptional activity as indicated by decreased prostate-specific antigen (PSA) mRNA levels in both cell lines. AR/p52-02 also caused a reduction in levels of p21WAF/CIP1, which is a direct AR targeted gene in that its expression correlates with androgen stimulation and mitogenic proliferation in prostate cancer under physiologic levels of androgen, likely by disrupting the AR signaling axis. The reduced level of cyclinD1 reported previously for this compound may be due to the reduction in nuclear presence and activity of p52, which directly regulates cyclinD1 expression, as well as the reduction in p21WAF/CIP1, since p21WAF/CIP1 is reported to stabilize nuclear cyclinD1 in prostate cancer. Overall, the data suggest that specifically inhibiting the interaction of AR with p52 and blocking activity of p52 and pARser81 may be an effective means of reducing castration-resistant prostate cancer cell growth. PMID:26622945

Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells

PubMed Central

Muniyan, Sakthivel; D’Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G.; Bu, Xiu R.; Batra, Surinder K.; Lin, Ming-Fong

2015-01-01

Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents. PMID:26121643

Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells.

PubMed

Ingersoll, Matthew A; Lyons, Anastesia S; Muniyan, Sakthivel; D'Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G; Bu, Xiu R; Batra, Surinder K; Lin, Ming-Fong

2015-01-01

Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents.

Regulation of androgen receptor and histone deacetylase 1 by Mdm2-mediated ubiquitylation.

PubMed

Gaughan, Luke; Logan, Ian R; Neal, David E; Robson, Craig N

2005-01-01

The androgen receptor (AR) is a member of the nuclear hormone receptor family of transcription factors and plays a critical role in regulating the expression of genes involved in androgen-dependent and -independent tumour formation. Regulation of the AR is achieved by alternate binding of either histone acetyltransferase (HAT)-containing co-activator proteins, or histone deacetylase 1 (HDAC1). Factors that control AR stability may also constitute an important regulatory mechanism, a notion that has been confirmed with the finding that the AR is a direct target for Mdm2-mediated ubiquitylation and proteolysis. Using chromatin immunoprecipitation (ChIP) and re-ChIP analyses, we show that Mdm2 associates with AR and HDAC1 at the active androgen-responsive PSA promoter in LNCaP prostate cancer cells. Furthermore, we demonstrate that Mdm2-mediated modification of AR and HDAC1 catalyses protein destabilization and attenuates AR sactivity, suggesting that ubiquitylation of the AR and HDAC1 may constitute an additional mechanism for regulating AR function. We also show that HDAC1 and Mdm2 function co-operatively to reduce AR-mediated transcription that is attenuated by the HAT activity of the AR co-activator Tip60, suggesting interplay between acetylation status and receptor ubiquitylation in AR regulation. In all, our data indicates a novel role for Mdm2 in regulating components of the AR transcriptosome.

Role of cationic channel TRPV2 in promoting prostate cancer migration and progression to androgen resistance.

PubMed

Monet, Michaël; Lehen'kyi, V'yacheslav; Gackiere, Florian; Firlej, Virginie; Vandenberghe, Matthieu; Roudbaraki, Morad; Gkika, Dimitra; Pourtier, Albin; Bidaux, Gabriel; Slomianny, Christian; Delcourt, Philippe; Rassendren, François; Bergerat, Jean-Pierre; Ceraline, Jocelyn; Cabon, Florence; Humez, Sandrine; Prevarskaya, Natalia

2010-02-01

Castration resistance in prostate cancer (PCa) constitutes an advanced, aggressive disease with poor prognosis, associated with uncontrolled cell proliferation, resistance to apoptosis, and enhanced invasive potential. The molecular mechanisms involved in the transition of PCa to castration resistance are obscure. Here, we report that the nonselective cationic channel transient receptor potential vanilloid 2 (TRPV2) is a distinctive feature of castration-resistant PCa. TRPV2 transcript levels were higher in patients with metastatic cancer (stage M1) compared with primary solid tumors (stages T2a and T2b). Previous studies of the TRPV2 channel indicated that it is primarily involved in cancer cell migration and not in cell growth. Introducing TRPV2 into androgen-dependent LNCaP cells enhanced cell migration along with expression of invasion markers matrix metalloproteinase (MMP) 9 and cathepsin B. Consistent with the likelihood that TRPV2 may affect cancer cell aggressiveness by influencing basal intracellular calcium levels, small interfering RNA-mediated silencing of TRPV2 reduced the growth and invasive properties of PC3 prostate tumors established in nude mice xenografts, and diminished expression of invasive enzymes MMP2, MMP9, and cathepsin B. Our findings establish a role for TRPV2 in PCa progression to the aggressive castration-resistant stage, prompting evaluation of TRPV2 as a potential prognostic marker and therapeutic target in the setting of advanced PCa.

Connectivity Mapping for Candidate Therapeutics Identification Using Next Generation Sequencing RNA-Seq Data

PubMed Central

McArt, Darragh G.; Dunne, Philip D.; Blayney, Jaine K.; Salto-Tellez, Manuel; Van Schaeybroeck, Sandra; Hamilton, Peter W.; Zhang, Shu-Dong

2013-01-01

The advent of next generation sequencing technologies (NGS) has expanded the area of genomic research, offering high coverage and increased sensitivity over older microarray platforms. Although the current cost of next generation sequencing is still exceeding that of microarray approaches, the rapid advances in NGS will likely make it the platform of choice for future research in differential gene expression. Connectivity mapping is a procedure for examining the connections among diseases, genes and drugs by differential gene expression initially based on microarray technology, with which a large collection of compound-induced reference gene expression profiles have been accumulated. In this work, we aim to test the feasibility of incorporating NGS RNA-Seq data into the current connectivity mapping framework by utilizing the microarray based reference profiles and the construction of a differentially expressed gene signature from a NGS dataset. This would allow for the establishment of connections between the NGS gene signature and those microarray reference profiles, alleviating the associated incurring cost of re-creating drug profiles with NGS technology. We examined the connectivity mapping approach on a publicly available NGS dataset with androgen stimulation of LNCaP cells in order to extract candidate compounds that could inhibit the proliferative phenotype of LNCaP cells and to elucidate their potential in a laboratory setting. In addition, we also analyzed an independent microarray dataset of similar experimental settings. We found a high level of concordance between the top compounds identified using the gene signatures from the two datasets. The nicotine derivative cotinine was returned as the top candidate among the overlapping compounds with potential to suppress this proliferative phenotype. Subsequent lab experiments validated this connectivity mapping hit, showing that cotinine inhibits cell proliferation in an androgen dependent manner. Thus the results in this study suggest a promising prospect of integrating NGS data with connectivity mapping. PMID:23840550

Proteomic Analysis of the Androgen Receptor via MS-compatible Purification of Biotinylated Protein on Streptavidin Resin

PubMed Central

Austin, Ryan J.; Smidansky, Heidi M.; Holstein, Carly A.; Chang, Deborah K.; Epp, Angela; Josephson, Neil C.; Martin, Daniel B.

2012-01-01

The strength of the streptavidin/biotin interaction poses challenges for the recovery of biotinylated molecules from streptavidin resins. As an alternative to high temperature elution in urea containing buffers, we show mono-biotinylated proteins can be released with relatively gentle heating in the presence of biotin and 2% SDS/Rapigest, avoiding protein carbamylation and minimizing streptavidin dissociation. We demonstrate the utility of this mild elution strategy in two studies of the human androgen receptor (AR). In the first, in which formaldehyde crosslinked complexes are analyzed in yeast, a mass spectrometry-based comparison of the AR complex using SILAC reveals an association between the androgen activated AR and the Hsp90 chaperonin, while Hsp70 chaperonins associate specifically with the unliganded complex. In the second study, the endogenous AR is quantified in the LNCaP cell line by absolute SILAC and MRM-MS showing approximately 127,000 AR copies per cell, substantially more than previously measured using radioligand binding. PMID:22116683

Transfected Poly(I:C) Activates Different dsRNA Receptors, Leading to Apoptosis or Immunoadjuvant Response in Androgen-independent Prostate Cancer Cells*

PubMed Central

Palchetti, Sara; Starace, Donatella; De Cesaris, Paola; Filippini, Antonio; Ziparo, Elio; Riccioli, Anna

2015-01-01

Despite the effectiveness of surgery or radiation therapy for the treatment of early-stage prostate cancer (PCa), there is currently no effective strategy for late-stage disease. New therapeutic targets are emerging; in particular, dsRNA receptors Toll-like receptor 3 (TLR3) and cytosolic helicases expressed by cancer cells, once activated, exert a pro-apoptotic effect in different tumors. We previously demonstrated that the synthetic analog of dsRNA poly(I:C) induces apoptosis in the androgen-dependent PCa cell line LNCaP in a TLR3-dependent fashion, whereas only a weak apoptotic effect is observed in the more aggressive and androgen-independent PCa cells PC3 and DU145. In this paper, we characterize the receptors and the signaling pathways involved in the remarkable apoptosis induced by poly(I:C) transfected by Lipofectamine (in-poly(I:C)) compared with the 12-fold higher free poly(I:C) concentration in PC3 and DU145 cells. By using genetic inhibition of different poly(I:C) receptors, we demonstrate the crucial role of TLR3 and Src in in-poly(I:C)-induced apoptosis. Therefore, we show that the increased in-poly(I:C) apoptotic efficacy is due to a higher binding of endosomal TLR3. On the other hand, we show that in-poly(I:C) binding to cytosolic receptors MDA5 and RIG-I triggers IRF3-mediated signaling, leading uniquely to the up-regulation of IFN-β, which likely in turn induces increased TLR3, MDA5, and RIG-I proteins. In summary, in-poly(I:C) activates two distinct antitumor pathways in PC3 and DU145 cells: one mediated by the TLR3/Src/STAT1 axis, leading to apoptosis, and the other one mediated by MDA5/RIG-I/IRF3, leading to immunoadjuvant IFN-β expression. PMID:25568326

Androgen deprivation and stem cell markers in prostate cancers

PubMed Central

Tang, Yao; Hamburger, Anne W; Wang, Linbo; Khan, Mohammad Afnan; Hussain, Arif

2010-01-01

In our previous studies using human LNCaP xenografts and TRAMP (transgenic adenocarcinoma of mouse prostate) mice, androgen deprivation therapy (ADT) resulted in a temporary cessation of prostate cancer (PCa) growth, but then tumors grew faster with more malignant behaviour. To understand whether cancer stem cells might play a role in PCa progression in these animal models, we investigated the expressions of stem cell-related markers in tumors at different time points after ADT. In both animal models, enhanced expressions of stem cell markers were observed in tumors of castrated mice, as compared to non-castrated controls. This increased cell population that expressed stem cell markers is designated as stem-like cells (SLC) in this article. We also observed that the SLC peaked at relatively early time points after ADT, before tumors resumed their growth. These results suggest that the SLC population may play a role in tumor re-growth and disease progression, and that targeting the SLC at their peak-expression time point may prevent tumor recurrence following ADT. PMID:20126580

Protein arginine methyltransferase 5 functions as an epigenetic activator of the androgen receptor to promote prostate cancer cell growth.

PubMed

Deng, X; Shao, G; Zhang, H-T; Li, C; Zhang, D; Cheng, L; Elzey, B D; Pili, R; Ratliff, T L; Huang, J; Hu, C-D

2017-03-02

Protein arginine methyltransferase 5 (PRMT5) is an emerging epigenetic enzyme that mainly represses transcription of target genes via symmetric dimethylation of arginine residues on histones H4R3, H3R8 and H2AR3. Accumulating evidence suggests that PRMT5 may function as an oncogene to drive cancer cell growth by epigenetic inactivation of several tumor suppressors. Here, we provide evidence that PRMT5 promotes prostate cancer cell growth by epigenetically activating transcription of the androgen receptor (AR) in prostate cancer cells. Knockdown of PRMT5 or inhibition of PRMT5 by a specific inhibitor reduces the expression of AR and suppresses the growth of multiple AR-positive, but not AR-negative, prostate cancer cells. Significantly, knockdown of PRMT5 in AR-positive LNCaP cells completely suppresses the growth of xenograft tumors in mice. Molecular analysis reveals that PRMT5 binds to the proximal promoter region of the AR gene and contributes mainly to the enriched symmetric dimethylation of H4R3 in the same region. Mechanistically, PRMT5 is recruited to the AR promoter by its interaction with Sp1, the major transcription factor responsible for AR transcription, and forms a complex with Brg1, an ATP-dependent chromatin remodeler, on the proximal promoter region of the AR gene. Furthermore, PRMT5 expression in prostate cancer tissues is significantly higher than that in benign prostatic hyperplasia tissues, and PRMT5 expression correlates positively with AR expression at both the protein and mRNA levels. Taken together, our results identify PRMT5 as a novel epigenetic activator of AR in prostate cancer. Given that inhibiting AR transcriptional activity or androgen synthesis remains the major mechanism of action for most existing anti-androgen agents, our findings also raise an interesting possibility that targeting PRMT5 may represent a novel approach for prostate cancer treatment by eliminating AR expression.

The Direct Inhibitory Effect of Dutasteride or Finasteride on Androgen Receptor Activity is Cell Line Specific

PubMed Central

Chhipa, Rishi Raj; Halim, Danny; Cheng, Jinrong; Zhang, Huan Yi; Mohler, James L.; Ip, Clement; Wu, Yue

2014-01-01

BACKGROUND Finasteride and dutasteride were developed originally as 5α-reductase inhibitors to block the conversion of testosterone to dihydrotestosterone (DHT). These drugs may possess off-target effects on the androgen receptor (AR) due to their structural similarity to DHT. METHODS A total of 4 human prostate cancer cell models were examined: LNCaP (T877A mutant AR), 22Rv1 (H874Y mutant AR), LAPC4 (wild type AR) and VCaP (wild type AR). Cells were cultured in 10% charcoal-stripped fetal bovine serum, either with or without DHT added to the medium. AR activity was evaluated using the ARE-luciferase assay or the expression of AR regulated genes. RESULTS Dutasteride was more potent than finasteride in interfering with DHT-stimulated AR signaling. Disruption of AR function was accompanied by decreased cell growth. Cells that rely on DHT for protection against death were particularly vulnerable to dutasteride. Different prostate cancer cell models exhibited different sensitivities to dutasteride and finasteride. LNCaP was most sensitive, LAPC4 and VCaP were intermediate, while 22Rv1 was least sensitive. Regardless of the AR genotype, if AR was transfected into drug-sensitive cells, AR was inhibited by drug treatment; and if AR was transfected into drug-resistant cells, AR was not inhibited. CONCLUSIONS The direct inhibitory effect of dutasteride or finasteride on AR signaling is cell line specific. Mutations in the ligand binding domain of AR do not appear to play a significant role in influencing the AR antagonistic effect of these drugs. Subcellular constituent is an important factor in determining the drug effect on AR function. PMID:23813737

Blockade of Androgen Markers Using a Novel Betasitosterol, Thioctic Acid and Carnitine-containing Compound in Prostate and Hair Follicle Cell-based Assays.

PubMed

Chen, Li; Wang, Jiaolong; Mouser, Glen; Li, Yan Chun; Marcovici, Geno

2016-06-01

Androgenetic alopecia (AGA) affects approximately 70% of men and 40% of women in an age-dependent manner and is partially mediated by androgen hormones. Benign prostatic hyperplasia (BPH) similarly affects 50% of the male population, rising by 10% each decade. Finasteride inhibits 5-alpha reductase (5AR) and is used to treat both disorders, despite offering limited clinical benefits accompanied by significant adverse side effects. Building on our previous work demonstrating the efficacy of naturally derived 5AR inhibitors (such as stigmasterol and beta sitosterol), we hypothesize that targeting 5AR as well as inflammatory pathways may yield improved efficacy in AGA and BPH. Here we address these dual pathomechanisms by examining the potency of a novel composition using in vitro assays of representative cell lines for AGA (hair follicle dermal papilla cells) and BPH (LNCaP prostate cells), respectively. Exposure of cells to the novel test composition down-regulated mRNA expression profiles characteristic of both disease processes, which outperformed finasteride. Changes in mRNA expression were corroborated at the protein level as assessed by western blotting. These studies provide proof of concept that novel, naturally derived compositions simultaneously targeting 5AR and inflammatory mediators may represent a rational approach to treating AGA and BPH. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Cytometric comparisons between circulating tumor cells from prostate cancer patients and the prostate-tumor-derived LNCaP cell line

NASA Astrophysics Data System (ADS)

Lazar, Daniel C.; Cho, Edward H.; Luttgen, Madelyn S.; Metzner, Thomas J.; Loressa Uson, Maria; Torrey, Melissa; Gross, Mitchell E.; Kuhn, Peter

2012-02-01

Many important experiments in cancer research are initiated with cell line data analysis due to the ease of accessibility and utilization. Recently, the ability to capture and characterize circulating tumor cells (CTCs) has become more prevalent in the research setting. This ability to detect, isolate and analyze CTCs allows us to directly compare specific protein expression levels found in patient CTCs to cell lines. In this study, we use immunocytochemistry to compare the protein expression levels of total cytokeratin (CK) and androgen receptor (AR) in CTCs and cell lines from patients with prostate cancer to determine what translational insights might be gained through the use of cell line data. A non-enrichment CTC detection assay enables us to compare cytometric features and relative expression levels of CK and AR by indirect immunofluorescence from prostate cancer patients against the prostate cancer cell line LNCaP. We measured physical characteristics of these two groups and observed significant differences in cell size, fluorescence intensity and nuclear to cytoplasmic ratio. We hope that these experiments will initiate a foundation to allow cell line data to be compared against characteristics of primary cells from patients.

The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

DTIC Science & Technology

2005-07-01

METHODS InVitro Growth Assay Tissue Culture DU145, PC3, and LN-17 cells ( 1 x 105 per well) were plated in 12-well plates in RPMI containing 10% FBS. Human...specific ELISA kit. 1 ] LNSI Parental LNCaP, neo, and IL- # OLN-S17 6 overexpressing (LN-S15 c 0.8 - and LN-S17) cells were 0e cultured in either...independence [1,2]. Stat3, a member of Janus Shadyside Medical Center, Suite G03, 5200 Centre Avenue, Kinase (JAK)-Signal Transducers and Activators of

Autophagic degradation of the androgen receptor mediated by increased phosphorylation of p62 suppresses apoptosis in hypoxia.

PubMed

Mitani, Takakazu; Minami, Masato; Harada, Naoki; Ashida, Hitoshi; Yamaji, Ryoichi

2015-10-01

Prostate cancer grows under hypoxic conditions. Hypoxia decreases androgen receptor (AR) protein levels. However, the molecular mechanism remains unclear. Here, we report that p62-mediated autophagy degrades AR protein and suppresses apoptosis in prostate cancer LNCaP cells in hypoxia. In LNCaP cells, hypoxia decreased AR at the protein level, but not at the mRNA level. Hypoxia-induced AR degradation was inhibited not only by knockdown of LC3, a key component of the autophagy machinery, but also by knockdown of p62. Depletion of p62 enhanced hypoxia-induced poly(ADP-ribose) polymerase cleavage and caspase-3 cleavage, markers of apoptosis, whereas simultaneous knockdown of p62 and AR suppressed hypoxia-induced apoptosis. Hypoxia increased the formation of a cytosolic p62-AR complex and enhanced sequestration of AR from the nucleus. Formation of this complex was promoted by the increased phosphorylation of serine 403 in the ubiquitin-associated domain of p62 during hypoxia. An antioxidant and an AMP-activated protein kinase (AMPK) inhibitor reduced hypoxia-induced p62 phosphorylation at serine 403 and suppressed hypoxia-induced complex formation between AR and p62. These results demonstrate that hypoxia enhances the complex formation between p62 and AR by promoting phosphorylation of p62 at serine 403, probably through activating AMPK, and that p62-mediated autophagy degrades AR protein for cell survival in hypoxia. Copyright © 2015 Elsevier Inc. All rights reserved.

A comparative assessment of α-lipoic acid N-phenylamides as non-steroidal androgen receptor antagonists both on and off gold nanoparticles.

PubMed

Henderson, Luke C; Altimari, Jarrad M; Dyson, Gail; Servinis, Linden; Niranjan, Birunthi; Risbridger, Gail P

2012-02-01

A group of α-lipoic acid N-phenylamides were synthesized employing a variety of amide coupling protocols utilizing electron deficient anilines. These compounds were then assessed for their ability to block androgen-stimulated proliferation of a human prostate cancer cell line, LNCaP. These structurally simple compounds displayed anti-proliferative activities at, typically, 5-20 μM concentrations and were comparable to a commonly used anti-androgen Bicalutamide®. The inclusion of a disulfide (RS-SR) moiety, serving as an anchor to several metal nanoparticle systems (Au, Ag, Fe(2)O(3), etc.), does not impede any biological activity. Conjugation of these compounds to a gold nanoparticle surface resulted in a high degree of cellular toxicity, attributed to the absence of a biocompatible group such as PEG within the organic scaffold. Copyright © 2011 Elsevier Inc. All rights reserved.

New Strategy for Prostate Cancer Prevention Based on Selenium Suppression of Androgen Receptor Signaling

DTIC Science & Technology

2010-04-01

reductase. The Prostate Cancer Prevention Trial (PCPT) demonstrated that treatment with finasteride , an inhibitor of 5α-reductase, reduced prostate...Statement of Work (SOW). B. BODY Task 1. Determine the optimal dose of finasteride to achieve growth inhibition of tumor xenografts in nude mice... finasteride and we found in the literature doses of finasteride effective in inhibiting the growth of LNCaP xenografts in nude mice inhibiting LNCaP

Minoxidil may suppress androgen receptor-related functions.

PubMed

Hsu, Cheng-Lung; Liu, Jai-Shin; Lin, An-Chi; Yang, Chih-Hsun; Chung, Wen-Hung; Wu, Wen-Guey

2014-04-30

Although minoxidil has been used for more than two decades to treat androgenetic alopecia (AGA), an androgen-androgen receptor (AR) pathway-dominant disease, its precise mechanism of action remains elusive. We hypothesized that minoxidil may influence the AR or its downstream signaling. These tests revealed that minoxidil suppressed AR-related functions, decreasing AR transcriptional activity in reporter assays, reducing expression of AR targets at the protein level, and suppressing AR-positive LNCaP cell growth. Dissecting the underlying mechanisms, we found that minoxidil interfered with AR-peptide, AR-coregulator, and AR N/C-terminal interactions, as well as AR protein stability. Furthermore, a crystallographic analysis using the AR ligand-binding domain (LBD) revealed direct binding of minoxidil to the AR in a minoxidil-AR-LBD co-crystal model, and surface plasmon resonance assays demonstrated that minoxidil directly bound the AR with a K(d) value of 2.6 µM. Minoxidil also suppressed AR-responsive reporter activity and decreased AR protein stability in human hair dermal papilla cells. The current findings provide evidence that minoxidil could be used to treat both cancer and age-related disease, and open a new avenue for applications of minoxidil in treating androgen-AR pathway-related diseases.

Minoxidil may suppress androgen receptor-related functions

PubMed Central

Hsu, Cheng-Lung; Liu, Jai-Shin; Lin, An-Chi; Yang, Chih-Hsun; Chung, Wen-Hung; Wu, Wen-Guey

2014-01-01

Although minoxidil has been used for more than two decades to treat androgenetic alopecia (AGA), an androgen-androgen receptor (AR) pathway-dominant disease, its precise mechanism of action remains elusive. We hypothesized that minoxidil may influence the AR or its downstream signaling. These tests revealed that minoxidil suppressed AR-related functions, decreasing AR transcriptional activity in reporter assays, reducing expression of AR targets at the protein level, and suppressing AR-positive LNCaP cell growth. Dissecting the underlying mechanisms, we found that minoxidil interfered with AR-peptide, AR-coregulator, and AR N/C-terminal interactions, as well as AR protein stability. Furthermore, a crystallographic analysis using the AR ligand-binding domain (LBD) revealed direct binding of minoxidil to the AR in a minoxidil-AR-LBD co-crystal model, and surface plasmon resonance assays demonstrated that minoxidil directly bound the AR with a Kd value of 2.6 μM. Minoxidil also suppressed AR-responsive reporter activity and decreased AR protein stability in human hair dermal papilla cells. The current findings provide evidence that minoxidil could be used to treat both cancer and age-related disease, and open a new avenue for applications of minoxidil in treating androgen-AR pathway-related diseases. PMID:24742982

Registered report: the androgen receptor induces a distinct transcriptional program in castration-resistant prostate cancer in man

PubMed Central

Chronscinski, Denise; Cherukeri, Srujana; Tan, Fraser; Lomax, Joelle; Iorns, Elizabeth

2015-01-01

The Prostate Cancer Foundation-Movember Foundation Reproducibility Initiative (PCFMFRI) seeks to address growing concerns about reproducibility in scientific research by conducting replications of recent papers in the field of prostate cancer. This Registered Report describes the proposed replication plan of key experiments from “The Androgen Receptor Induces a Distinct Transcriptional Program in Castration-Resistant Prostate Cancer in Man” by Sharma and colleagues (2013), published in Cancer Cell in 2013. Of thousands of targets for the androgen receptor (AR), the authors elucidated a subset of 16 core genes that were consistently downregulated with castration and re-emerged with castration resistance. These 16 AR binding sites were distinct from those observed in cells in culture. The authors suggested that cellular context can have dramatic effects on downstream transcriptional regulation of AR binding sites. The present study will attempt to replicate Fig. 7C by comparing gene expression of the 16 core genes identified by Sharma and colleagues in xenograft tumor tissue compared to androgen treated LNCaP cells in vitro. The Prostate Cancer Foundation-Movember Foundation Reproducibility Initiative is a collaboration between the Prostate Cancer Foundation, the Movember Initiative, and Science Exchange, and the results of the replications will be published by PeerJ. PMID:26401447

Milk thistle and prostate cancer: differential effects of pure flavonolignans from Silybum marianum on antiproliferative end points in human prostate carcinoma cells.

PubMed

Davis-Searles, Paula R; Nakanishi, Yuka; Kim, Nam-Cheol; Graf, Tyler N; Oberlies, Nicholas H; Wani, Mansukh C; Wall, Monroe E; Agarwal, Rajesh; Kroll, David J

2005-05-15

Extracts from the seeds of milk thistle, Silybum marianum, are known commonly as silibinin and silymarin and possess anticancer actions on human prostate carcinoma in vitro and in vivo. Seven distinct flavonolignan compounds and a flavonoid have been isolated from commercial silymarin extracts. Most notably, two pairs of diastereomers, silybin A and silybin B and isosilybin A and isosilybin B, are among these compounds. In contrast, silibinin is composed only of a 1:1 mixture of silybin A and silybin B. With these isomers now isolated in quantities sufficient for biological studies, each pure compound was assessed for antiproliferative activities against LNCaP, DU145, and PC3 human prostate carcinoma cell lines. Isosilybin B was the most consistently potent suppressor of cell growth relative to either the other pure constituents or the commercial extracts. Isosilybin A and isosilybin B were also the most effective suppressors of prostate-specific antigen secretion by androgen-dependent LNCaP cells. Silymarin and silibinin were shown for the first time to suppress the activity of the DNA topoisomerase IIalpha gene promoter in DU145 cells and, among the pure compounds, isosilybin B was again the most effective. These findings are significant in that isosilybin B composes no more than 5% of silymarin and is absent from silibinin. Whereas several other more abundant flavonolignans do ultimately influence the same end points at higher exposure concentrations, these findings are suggestive that extracts enriched for isosilybin B, or isosilybin B alone, might possess improved potency in prostate cancer prevention and treatment.

Differential Effects of Tissue Culture Coating Substrates on Prostate Cancer Cell Adherence, Morphology and Behavior

PubMed Central

Liberio, Michelle S.; Sadowski, Martin C.; Soekmadji, Carolina; Davis, Rohan A.; Nelson, Colleen C.

2014-01-01

Weak cell-surface adhesion of cell lines to tissue culture surfaces is a common problem and presents technical limitations to the design of experiments. To overcome this problem, various surface coating protocols have been developed. However, a comparative and precise real-time measurement of their impact on cell behavior has not been conducted. The prostate cancer cell line LNCaP, derived from a patient lymph node metastasis, is a commonly used model system in prostate cancer research. However, the cells’ characteristically weak attachment to the surface of tissue culture vessels and cover slips has impeded their manipulation and analysis and use in high throughput screening. To improve the adherence of LNCaP cells to the culture surface, we compared different coating reagents (poly-l-lysine, poly-l-ornithine, collagen type IV, fibronectin, and laminin) and culturing conditions and analyzed their impact on cell proliferation, adhesion, morphology, mobility and gene expression using real-time technologies. The results showed that fibronectin, poly-l-lysine and poly-l-ornithine improved LNCaP cells adherence and provoked cell morphology alterations, such as increase of nuclear and cellular area. These coating reagents also induced a higher expression of F-actin and reduced cell mobility. In contrast, laminin and collagen type IV did not improve adherence but promoted cell aggregation and affected cell morphology. Cells cultured in the presence of laminin displayed higher mobility than control cells. All the coating conditions significantly affected cell viability; however, they did not affect the expression of androgen receptor-regulated genes. Our comparative findings provide important insight for the selection of the ideal coating reagent and culture conditions for the cancer cell lines with respect to their effect on proliferation rate, attachment, morphology, migration, transcriptional response and cellular cytoskeleton arrangement. PMID:25375165

Identification of an IL-1-induced gene expression pattern in AR+ PCa cells that mimics the molecular phenotype of AR- PCa cells.

PubMed

Thomas-Jardin, Shayna E; Kanchwala, Mohammed S; Jacob, Joan; Merchant, Sana; Meade, Rachel K; Gahnim, Nagham M; Nawas, Afshan F; Xing, Chao; Delk, Nikki A

2018-06-01

In immunosurveillance, bone-derived immune cells infiltrate the tumor and secrete inflammatory cytokines to destroy cancer cells. However, cancer cells have evolved mechanisms to usurp inflammatory cytokines to promote tumor progression. In particular, the inflammatory cytokine, interleukin-1 (IL-1), is elevated in prostate cancer (PCa) patient tissue and serum, and promotes PCa bone metastasis. IL-1 also represses androgen receptor (AR) accumulation and activity in PCa cells, yet the cells remain viable and tumorigenic; suggesting that IL-1 may also contribute to AR-targeted therapy resistance. Furthermore, IL-1 and AR protein levels negatively correlate in PCa tumor cells. Taken together, we hypothesize that IL-1 reprograms AR positive (AR + ) PCa cells into AR negative (AR - ) PCa cells that co-opt IL-1 signaling to ensure AR-independent survival and tumor progression in the inflammatory tumor microenvironment. LNCaP and PC3 PCa cells were treated with IL-1β or HS-5 bone marrow stromal cell (BMSC) conditioned medium and analyzed by RNA sequencing and RT-QPCR. To verify genes identified by RNA sequencing, LNCaP, MDA-PCa-2b, PC3, and DU145 PCa cell lines were treated with the IL-1 family members, IL-1α or IL-1β, or exposed to HS-5 BMSC in the presence or absence of Interleukin-1 Receptor Antagonist (IL-1RA). Treated cells were analyzed by western blot and/or RT-QPCR. Comparative analysis of sequencing data from the AR + LNCaP PCa cell line versus the AR - PC3 PCa cell line reveals an IL-1-conferred gene suite in LNCaP cells that is constitutive in PC3 cells. Bioinformatics analysis of the IL-1 regulated gene suite revealed that inflammatory and immune response pathways are primarily elicited; likely facilitating PCa cell survival and tumorigenicity in an inflammatory tumor microenvironment. Our data supports that IL-1 reprograms AR + PCa cells to mimic AR - PCa gene expression patterns that favor AR-targeted treatment resistance and cell survival. © 2018 Wiley Periodicals, Inc.

Imaging Prostate Cancer Microenvironment by collagen Hybridization

DTIC Science & Technology

2014-10-01

from enlarged lymph nodes. Figure 3. Ex vivo NIRF imaging of PC-3 PIP xenograft. AI = androgen independent, AR = androgen receptor negative, PSMA ...center O.D. rim/focal ROI PC-3 rapid 0.25 ± .09 1.21 ± 0.40 PC-3 ( PSMA +) PIP rapid 0.26 ± .12 NA DU-145 slow 0.01 ± 0.01 0.06 ± 0.02 HP LNCaP

Raman and coherent anti-Stokes Raman scattering microscopy studies of changes in lipid content and composition in hormone-treated breast and prostate cancer cells

NASA Astrophysics Data System (ADS)

Potcoava, Mariana C.; Futia, Gregory L.; Aughenbaugh, Jessica; Schlaepfer, Isabel R.; Gibson, Emily A.

2014-11-01

Increasing interest in the role of lipids in cancer cell proliferation and resistance to drug therapies has motivated the need to develop better tools for cellular lipid analysis. Quantification of lipids in cells is typically done by destructive chromatography protocols that do not provide spatial information on lipid distribution and prevent dynamic live cell studies. Methods that allow the analysis of lipid content in live cells are therefore of great importance. Using micro-Raman spectroscopy and coherent anti-Stokes Raman scattering (CARS) microscopy, we generated a lipid profile for breast (T47D, MDA-MB-231) and prostate (LNCaP, PC3) cancer cells upon exposure to medroxyprogesterone acetate (MPA) and synthetic androgen R1881. Combining Raman spectra with CARS imaging, we can study the process of hormone-mediated lipogenesis. Our results show that hormone-treated cancer cells T47D and LNCaP have an increased number and size of intracellular lipid droplets and higher degree of saturation than untreated cells. MDA-MB-231 and PC3 cancer cells showed no significant changes upon treatment. Principal component analysis with linear discriminant analysis of the Raman spectra was able to differentiate between cancer cells that were treated with MPA, R1881, and untreated.

Prolongation of Off-Cycle Interval by Finasteride Is Not Associated with Survival Improvement in Intermittent Androgen Deprivation Therapy in LNCaP Tumor Model

PubMed Central

Wang, Yujuan; Gupta, Shubham; Hua, Vi; Ramos-Garcia, Raquel; Shevrin, Daniel; Jovanovic, Borko D.; Nelson, Joel B

2009-01-01

BACKGROUND We have previously reported that finasteride administration in intermittent androgen deprivation therapy (IADT) can improve survival of nude mice bearing LNCaP xenograft tumors when the duration of off-cycle in IADT was fixed. A recent retrospective study showed that addition of finasteride doubled the duration of the off-cycle, without changing progression to castration resistance. In view of the above difference, we attempted to investigate the relationship of 5α-reductase inhibition with the off-cycle interval and overall survival in a murine model. METHODS Subcutaneous LNCaP tumors were established in nude mice (Balb/C-Nu). After the tumors reached a size of 0.5 cm in diameter, the mice were castrated and followed up for 2 weeks after which they were randomized to continuous androgen deprivation (CAD), CAD plus finasteride, IADT, and IADT plus finasteride. The off-cycle was discontinued when the tumor volume was doubled. Subsequent cycles were carried out similarly. RESULTS Use of finasteride during the off-cycle of IADT doubled the first off-cycle duration. However, prolongation of the off-cycle by finasteride did not translate into an increase in overall survival. CONCLUSIONS The survival advantage of IADT+F over IADT that we previously reported was lost when the off-cycle prolongation by finasteride was allowed. Maximum possible lengthening of the off-cycle by 5α-reductase inhibition is not associated with survival improvement in this animal model. PMID:19739129

Nephrotoxicity of Epigenetic Inhibitors Used for the Treatment of Cancer

PubMed Central

Scholpa, N.E.; Kolli, R.T.; Moore, M.; Arnold, R.D.; Glenn, T.C.; Cummings, B.S.

2016-01-01

This study determined the anti-neoplastic activity and nephrotoxicity of epigenetic inhibitors in vitro. The therapeutic efficacy of epigenetic inhibitors was determined in human prostate cancer cells (PC-3 and LNCaP) using the DNA methyltransferase inhibitor 5-azacytidine (5-Aza) and the histone deacetylase inhibitor trichostatin A (TSA). Cells were also treated with carbamazepine (CBZ), an anti-convulsant with histone deacetylase inhibitor-like properties. 5-Aza, TSA or CBZ alone did not decrease MTT staining in PC-3 or LNCaP cells after 48 hr. In contrast, docetaxel, a frontline chemotherapeutic induced concentration-dependent decreases in MTT staining. Pretreatment with 5-Aza or TSA increased docetaxel-induced cytotoxicity in LNCaP cells, but not PC-3 cells. TSA pretreatment also increased cisplatin-induced toxicity in LNCaP cells. Carfilzomib (CFZ), a protease inhibitor approved for the treatment of multiple myeloma had minimal effect on LNCaP cell viability, but reduced MTT staining 50% in PC-3 cells compared to control, and pretreatment with 5-Aza further enhanced toxicity. Treatment of normal rat kidney (NRK) and human embryonic kidney 293 (HEK293) cells with the same concentrations of epigenetic inhibitors used in prostate cancer cells significantly decreased MTT staining in all cell lines after 48 hr. Interestingly, we found that the toxicity of epigenetic inhibitors to kidney cells was dependent on both the compound and the stage of cell growth. The effect of 5-Aza and TSA on DNA methyltransferase and histone deacetylase activity, respectively, was confirmed by assessing the methylation and acetylation of the CDK inhibitor p21. Collectively, these data show that combinatorial treatment with epigenetic inhibitors alters the efficacy of chemotherapeutics in cancer cells in a compound- and cell-specific manner; however, this treatment also has the potential to induce nephrotoxic cell injury. PMID:27543423

Antiproliferative activity of novel imidazopyridine derivatives on castration-resistant human prostate cancer cells.

PubMed

Muniyan, Sakthivel; Chou, Yu-Wei; Ingersoll, Matthew A; Devine, Alexus; Morris, Marisha; Odero-Marah, Valerie A; Khan, Shafiq A; Chaney, William G; Bu, Xiu R; Lin, Ming-Fong

2014-10-10

Metastatic prostate cancer (mPCa) relapses after a short period of androgen deprivation therapy and becomes the castration-resistant prostate cancer (CR PCa); to which the treatment is limited. Hence, it is imperative to identify novel therapeutic agents towards this patient population. In the present study, antiproliferative activities of novel imidazopyridines were compared. Among three derivatives, PHE, AMD and AMN, examined, AMD showed the highest inhibitory activity on LNCaP C-81 cell proliferation, following dose- and time-dependent manner. Additionally, AMD exhibited significant antiproliferative effect against a panel of PCa cells, but not normal prostate epithelial cells. Further, when compared to AMD, its derivative DME showed higher inhibitory activities on PCa cell proliferation, clonogenic potential and in vitro tumorigenicity. The inhibitory activity was apparently in part due to the induction of apoptosis. Mechanistic studies indicate that AMD and DME treatments inhibited both AR and PI3K/Akt signaling. The results suggest that better understanding of inhibitory mechanisms of AMD and DME could help design novel therapeutic agents for improving the treatment of CR PCa. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Antiproliferative activity of novel imidazopyridine derivatives on castration-resistant human prostate cancer cells

PubMed Central

Muniyan, Sakthivel; Chou, Yu-Wei; Ingersoll, Matthew A.; Devine, Alexus; Morris, Marisha; Odero-Marah, Valerie A.; Khan, Shafiq A.; Chaney, William G.; Bu, Xiu R.; Lin, Ming-Fong

2014-01-01

Metastatic prostate cancer (mPCa) relapses after a short period of androgen deprivation therapy and becomes the castration-resistant prostate cancer (CR PCa); to which the treatment is limited. Hence, it is imperative to identify novel therapeutic agents towards this patient population. In the present study, antiproliferative activities of novel imidazopyridines were compared. Among three derivatives, PHE, AMD and AMN, examined, AMD showed the highest inhibitory activity on LNCaP C-81 cell proliferation, following dose- and time-dependent manner. Additionally, AMD exhibited significant antiproliferative effect against a panel of PCa cells, but not normal prostate epithelial cells. Further, when compared to AMD, its derivative DME showed higher inhibitory activities on PCa cell proliferation, clonogenic potential and in vitro tumorigenicity. The inhibitory activity was apparently in part due to the induction of apoptosis. Mechanistic studies indicate that AMD and DME treatments inhibited both AR and PI3K/Akt signaling. The results suggest that better understanding of inhibitory mechanisms of AMD and DME could help design novel therapeutic agents for improving the treatment of CR PCa. PMID:25050738

Melatonin Decreases Glucose Metabolism in Prostate Cancer Cells: A 13C Stable Isotope-Resolved Metabolomic Study.

PubMed

Hevia, David; Gonzalez-Menendez, Pedro; Fernandez-Fernandez, Mario; Cueto, Sergio; Rodriguez-Gonzalez, Pablo; Garcia-Alonso, Jose I; Mayo, Juan C; Sainz, Rosa M

2017-07-26

The pineal neuroindole melatonin exerts an exceptional variety of systemic functions. Some of them are exerted through its specific membrane receptors type 1 and type 2 (MT1 and MT2) while others are mediated by receptor-independent mechanisms. A potential transport of melatonin through facilitative glucose transporters (GLUT/ SLC2A ) was proposed in prostate cancer cells. The prostate cells have a particular metabolism that changes during tumor progression. During the first steps of carcinogenesis, oxidative phosphorylation is reactivated while the switch to the "Warburg effect" only occurs in advanced tumors and in the metastatic stage. Here, we investigated whether melatonin might change prostate cancer cell metabolism. To do so, 13 C stable isotope-resolved metabolomics in androgen sensitive LNCaP and insensitive PC-3 prostate cancer cells were employed. In addition to metabolite 13 C-labeling, ATP/AMP levels, and lactate dehydrogenase or pentose phosphate pathway activity were measured. Melatonin reduces lactate labeling in androgen-sensitive cells and it also lowers 13 C-labeling of tricarboxylic acid cycle metabolites and ATP production. In addition, melatonin reduces lactate 13 C-labeling in androgen insensitive prostate cancer cells. Results demonstrated that melatonin limits glycolysis as well as the tricarboxylic acid cycle and pentose phosphate pathway in prostate cancer cells, suggesting that the reduction of glucose uptake is a major target of the indole in this tumor type.

Silibinin inhibits aberrant lipid metabolism, proliferation and emergence of androgen-independence in prostate cancer cells via primarily targeting the sterol response element binding protein 1

PubMed Central

Nambiar, Dhanya K.; Deep, Gagan; Singh, Rana P.; Agarwal, Chapla; Agarwal, Rajesh

2014-01-01

Prostate cancer (PCA) kills thousands of men every year, demanding additional approaches to better understand and target this malignancy. Recently, critical role of aberrant lipogenesis is highlighted in prostate carcinogenesis, offering a unique opportunity to target it to reduce PCA. Here, we evaluated efficacy and associated mechanisms of silibinin in inhibiting lipid metabolism in PCA cells. At physiologically achievable levels in human, silibinin strongly reduced lipid and cholesterol accumulation specifically in human PCA cells but not in non-neoplastic prostate epithelial PWR-1E cells. Silibinin also decreased nuclear protein levels of sterol regulatory element binding protein 1 and 2 (SREBP1/2) and their target genes only in PCA cells. Mechanistically, silibinin activated AMPK, thereby increasing SREBP1 phosphorylation and inhibiting its nuclear translocation; AMPK inhibition reversed silibinin-mediated decrease in nuclear SREBP1 and lipid accumulation. Additionally, specific SREBP inhibitor fatostatin and stable overexpression of SREBP1 further confirmed the central role of SREBP1 in silibinin-mediated inhibition of PCA cell proliferation and lipid accumulation and cell cycle arrest. Importantly, silibinin also inhibited synthetic androgen R1881-induced lipid accumulation and completely abrogated the development of androgen-independent LNCaP cell clones via targeting SREBP1/2. Together, these mechanistic studies suggest that silibinin would be effective against PCA by targeting critical aberrant lipogenesis. PMID:25294820

Silibinin inhibits aberrant lipid metabolism, proliferation and emergence of androgen-independence in prostate cancer cells via primarily targeting the sterol response element binding protein 1.

PubMed

Nambiar, Dhanya K; Deep, Gagan; Singh, Rana P; Agarwal, Chapla; Agarwal, Rajesh

2014-10-30

Prostate cancer (PCA) kills thousands of men every year, demanding additional approaches to better understand and target this malignancy. Recently, critical role of aberrant lipogenesis is highlighted in prostate carcinogenesis, offering a unique opportunity to target it to reduce PCA. Here, we evaluated efficacy and associated mechanisms of silibinin in inhibiting lipid metabolism in PCA cells. At physiologically achievable levels in human, silibinin strongly reduced lipid and cholesterol accumulation specifically in human PCA cells but not in non-neoplastic prostate epithelial PWR-1E cells. Silibinin also decreased nuclear protein levels of sterol regulatory element binding protein 1 and 2 (SREBP1/2) and their target genes only in PCA cells. Mechanistically, silibinin activated AMPK, thereby increasing SREBP1 phosphorylation and inhibiting its nuclear translocation; AMPK inhibition reversed silibinin-mediated decrease in nuclear SREBP1 and lipid accumulation. Additionally, specific SREBP inhibitor fatostatin and stable overexpression of SREBP1 further confirmed the central role of SREBP1 in silibinin-mediated inhibition of PCA cell proliferation and lipid accumulation and cell cycle arrest. Importantly, silibinin also inhibited synthetic androgen R1881-induced lipid accumulation and completely abrogated the development of androgen-independent LNCaP cell clones via targeting SREBP1/2. Together, these mechanistic studies suggest that silibinin would be effective against PCA by targeting critical aberrant lipogenesis.

11β-hydroxyandrostenedione, the product of androstenedione metabolism in the adrenal, is metabolized in LNCaP cells by 5α-reductase yielding 11β-hydroxy-5α-androstanedione.

PubMed

Swart, Amanda C; Schloms, Lindie; Storbeck, Karl-Heinz; Bloem, Liezl M; Toit, Therina du; Quanson, Jonathan L; Rainey, William E; Swart, Pieter

2013-11-01

11β-Hydroxyandrostenedione (11OHA4), which is unique to the adrenal, was first isolated from human adrenal tissue in the fifties. It was later shown in the sixties that 11β-hydroxytestosterone (11OHT) was also produced by the human adrenal. Attention has shifted back to these adrenal androgens once more, as improved analytical techniques have enabled more accurate detection of steroid hormones. In this paper, we investigated the origin of these metabolites as well as their subsequent metabolism and examined a possible physiological role for 11OHA4 in prostate cancer cells. In H295R cells treated with forskolin and trilostane, etomidate, a reported cytochrome P450 11β-hydroxylase (CYP11B1) inhibitor, blocked the production of corticosterone, cortisol, 11OHA4 and 11OHT. The metabolism of androstenedione and testosterone by CYP11B1 and aldosterone synthase (CYP11B2) was assayed. Androstenedione was converted by CYP11B1, while the conversion by CYP11B2 was negligible. Both enzymes readily converted testosterone. The metabolism of these 11β-hydroxylated metabolites by 11β-hydroxysteroid dehydrogenase (11βHSD) types 1 and 2 was subsequently investigated. 11βHSD2 catalyzed the conversion of both 11OHA4 and 11OHT to their respective keto-steroids, while 11βHSD1 catalyzed the conversion of 11-ketoandrostenedione and 11-ketotestosterone to their respective hydroxy-steroids in Chinese hamster ovary cells. Investigating a functional role, steroid 5α-reductase types 1 and 2 converted 11OHA4 to 11β-hydroxy-5α-androstanedione (11OH-5α-dione), identified by accurate mass detection. UPLC-MS/MS analyses of 11OHA4 metabolism in LNCaP androgen-dependent prostate cancer cells, identified the 5α-reduced metabolite as well as 11-ketoandrostenedione and 11-ketotestosterone, with the latter indicating conversion by 17β-hydroxysteroid dehydrogenase. Downstream metabolism by 11βHSD2 and by 5α-reductase may therefore indicate a physiological role for 11OHA4 and/or 11OH-5α-dione in normal and prostate cancer cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prostate-Specific Membrane Antigen Targeted Polymersomes for Delivering Mocetinostat and Docetaxel to Prostate Cancer Cell Spheroids.

PubMed

Karandish, Fataneh; Haldar, Manas K; You, Seungyong; Brooks, Amanda E; Brooks, Benjamin D; Guo, Bin; Choi, Yongki; Mallik, Sanku

2016-11-30

Prostate cancer cells overexpress the prostate-specific membrane antigen (PSMA) receptors on the surface. Targeting the PSMA receptor creates a unique opportunity for drug delivery. Docetaxel is a Food and Drug Administration-approved drug for treating metastatic and androgen-independent prostate cancer, and mocetinostat is a potent inhibitor of class I histone deacetylases. In this study, we prepared reduction-sensitive polymersomes presenting folic acid on the surface and encapsulating either docetaxel or mocetinostat. The presence of folic acid allowed efficient targeting of the PSMA receptor and subsequent internalization of the polymeric vesicles in cultured LNCaP prostate cancer cell spheroids. The intracellular reducing agents efficiently released docetaxel and mocetinostat from the polymersomes. The combination of the two drug-encapsulated polymersome formulations significantly ( p < 0.05) decreased the viability of the LNCaP cells (compared to free drugs or control) in three-dimensional spheroid cultures. The calculated combination index value indicated a synergistic effect for the combination of mocetinostat and docetaxel. Thus, our PSMA-targeted drug-encapsulated polymersomes has the potential to lead to a new direction in prostate cancer therapy that decreases the toxicity and increases the efficacy of the drug delivery systems.

Prostate-Specific Membrane Antigen Targeted Polymersomes for Delivering Mocetinostat and Docetaxel to Prostate Cancer Cell Spheroids

PubMed Central

2016-01-01

Prostate cancer cells overexpress the prostate-specific membrane antigen (PSMA) receptors on the surface. Targeting the PSMA receptor creates a unique opportunity for drug delivery. Docetaxel is a Food and Drug Administration-approved drug for treating metastatic and androgen-independent prostate cancer, and mocetinostat is a potent inhibitor of class I histone deacetylases. In this study, we prepared reduction-sensitive polymersomes presenting folic acid on the surface and encapsulating either docetaxel or mocetinostat. The presence of folic acid allowed efficient targeting of the PSMA receptor and subsequent internalization of the polymeric vesicles in cultured LNCaP prostate cancer cell spheroids. The intracellular reducing agents efficiently released docetaxel and mocetinostat from the polymersomes. The combination of the two drug-encapsulated polymersome formulations significantly (p < 0.05) decreased the viability of the LNCaP cells (compared to free drugs or control) in three-dimensional spheroid cultures. The calculated combination index value indicated a synergistic effect for the combination of mocetinostat and docetaxel. Thus, our PSMA-targeted drug-encapsulated polymersomes has the potential to lead to a new direction in prostate cancer therapy that decreases the toxicity and increases the efficacy of the drug delivery systems. PMID:27917408

3,3′-Diindolylmethane, but not indole-3-carbinol, inhibits histone deacetylase activity in prostate cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beaver, Laura M., E-mail: beaverl@onid.orst.edu; School of Biological and Population Health Sciences, Oregon State University, 103 Milam Hall, Corvallis, OR 97331; Yu, Tian-Wei, E-mail: david.yu@oregonstate.edu

2012-09-15

Increased consumption of cruciferous vegetables is associated with a reduced risk of developing prostate cancer. Indole-3-carbinol (I3C) and 3,3′-diindolylmethane (DIM) are phytochemicals derived from cruciferous vegetables that have shown promise in inhibiting prostate cancer in experimental models. Histone deacetylase (HDAC) inhibition is an emerging target for cancer prevention and therapy. We sought to examine the effects of I3C and DIM on HDACs in human prostate cancer cell lines: androgen insensitive PC-3 cells and androgen sensitive LNCaP cells. I3C modestly inhibited HDAC activity in LNCaP cells by 25% but no inhibition of HDAC activity was detected in PC-3 cells. In contrast,more » DIM significantly inhibited HDAC activity in both cell lines by as much as 66%. Decreases in HDAC activity correlated with increased expression of p21, a known target of HDAC inhibitors. DIM treatment caused a significant decrease in the expression of HDAC2 protein in both cancer cell lines but no significant change in the protein levels of HDAC1, HDAC3, HDAC4, HDAC6 or HDAC8 was detected. Taken together, these results show that inhibition of HDAC activity by DIM may contribute to the phytochemicals' anti-proliferative effects in the prostate. The ability of DIM to target aberrant epigenetic patterns, in addition to its effects on detoxification of carcinogens, may make it an effective chemopreventive agent by targeting multiple stages of prostate carcinogenesis. -- Highlights: ► DIM inhibits HDAC activity and decreases HDAC2 expression in prostate cancer cells. ► DIM is significantly more effective than I3C at inhibiting HDAC activity. ► I3C has no effect on HDAC protein expression. ► Inhibition of HDAC activity by DIM is associated with increased p21 expression. ► HDAC inhibition may be a novel epigenetic mechanism for cancer prevention with DIM.« less

The phytochemical 3,3'-diindolylmethane decreases expression of AR-controlled DNA damage repair genes through repressive chromatin modifications and is associated with DNA damage in prostate cancer cells.

PubMed

Palomera-Sanchez, Zoraya; Watson, Gregory W; Wong, Carmen P; Beaver, Laura M; Williams, David E; Dashwood, Roderick H; Ho, Emily

2017-09-01

Androgen receptor (AR) is a transcription factor involved in normal prostate physiology and prostate cancer (PCa) development. 3,3'-Diindolylmethane (DIM) is a promising phytochemical agent against PCa that affects AR activity and epigenetic regulators in PCa cells. However, whether DIM suppresses PCa via epigenetic regulation of AR target genes is unknown. We assessed epigenetic regulation of AR target genes in LNCaP PCa cells and showed that DIM treatment led to epigenetic suppression of AR target genes involved in DNA repair (PARP1, MRE11, DNA-PK). Decreased expression of these genes was accompanied by an increase in repressive chromatin marks, loss of AR occupancy and EZH2 recruitment to their regulatory regions. Decreased DNA repair gene expression was associated with an increase in DNA damage (γH2Ax) and up-regulation of genomic repeat elements LINE1 and α-satellite. Our results suggest that DIM suppresses AR-dependent gene transcription through epigenetic modulation, leading to DNA damage and genome instability in PCa cells. Published by Elsevier Inc.

Overexpression of HepaCAM inhibits cell viability and motility through suppressing nucleus translocation of androgen receptor and ERK signaling in prostate cancer.

PubMed

Song, Xuedong; Wang, Yin; Du, Hongfei; Fan, Yanru; Yang, Xue; Wang, Xiaorong; Wu, Xiaohou; Luo, Chunli

2014-07-01

HepaCAM is suppressed in a variety of human cancers, and involved in cell adhesion, growth, migration, invasion, and survival. However, the expression and function of HepaCAM in prostate cancer are still unknown. HepaCAM expression has been detected by RT-PCR, Western blotting and immunohistochemistry staining in prostate cell lines RWPE-1, LNCap, DU145, PC3, and in 75 human prostate tissue specimens, respectively. Meanwhile, the cell proliferation ability was detected by WST-8 assay. The role of HepaCAM in prostate cancer cell migration and invasion was examined by wound healing and transwell assay. And flow cytometry was used to observe the apoptosis of prostate cancer cells. Then we detected changes of Androgen Receptor translocation and ERK signaling using immunofluorescence staining and western blot after overexpression of HepaCAM. The HepaCAM expression was significantly down-regulated in prostate cancer tissues and undetected in prostate cancer cells. However, the low HepaCAM expression was not statistically associated with clinicopathological characteristics of prostate cancer. Overexpression of HepaCAM in prostate cancer cells decreased the cell proliferation, migration and invasion, and induced the cell apoptosis. Meanwhile, HepaCAM prevented the androgen receptor translocation from the cytoplasm to the nucleus and down-regulated the MAPK/ERK signaling. Our results suggested that HepaCAM acted as a tumor suppressor in prostate cancer. HepaCAM inhibited cell viability and motility which might be through suppressing the nuclear translocation of Androgen Receptor and down-regulating the ERK signaling. Therefore, it was indicated that HepaCAM may be a potential therapeutic target for prostate cancer. © 2014 Wiley Periodicals, Inc.

Activation of AMP-Activated Protein Kinase by 3,3′-Diindolylmethane (DIM) Is Associated with Human Prostate Cancer Cell Death In Vitro and In Vivo

PubMed Central

Chen, Di; Banerjee, Sanjeev; Cui, Qiuzhi C.; Kong, Dejuan; Sarkar, Fazlul H.; Dou, Q. Ping

2012-01-01

There is a large body of scientific evidence suggesting that 3,3′-Diindolylmethane (DIM), a compound derived from the digestion of indole-3-carbinol, which is abundant in cruciferous vegetables, harbors anti-tumor activity in vitro and in vivo. Accumulating evidence suggests that AMP-activated protein kinase (AMPK) plays an essential role in cellular energy homeostasis and tumor development and that targeting AMPK may be a promising therapeutic option for cancer treatment in the clinic. We previously reported that a formulated DIM (BR-DIM; hereafter referred as B-DIM) with higher bioavailability was able to induce apoptosis and inhibit cell growth, angiogenesis, and invasion of prostate cancer cells. However, the precise molecular mechanism(s) for the anti-cancer effects of B-DIM have not been fully elucidated. In the present study, we investigated whether AMP-activated protein kinase (AMPK) is a molecular target of B-DIM in human prostate cancer cells. Our results showed, for the first time, that B-DIM could activate the AMPK signaling pathway, associated with suppression of the mammalian target of rapamycin (mTOR), down-regulation of androgen receptor (AR) expression, and induction of apoptosis in both androgen-sensitive LNCaP and androgen-insensitive C4-2B prostate cancer cells. B-DIM also activates AMPK and down-regulates AR in androgen-independent C4-2B prostate tumor xenografts in SCID mice. These results suggest that B-DIM could be used as a potential anti-cancer agent in the clinic for prevention and/or treatment of prostate cancer regardless of androgen responsiveness, although functional AR may be required. PMID:23056607

Nanotherapies for treating prostate cancer

NASA Astrophysics Data System (ADS)

Danquah, Michael

Current prostate cancer treatment remains ineffective primarily due to ineffectual therapeutic strategies and numerous tumor-associated physiological barriers which hinder efficacy of anticancer agents. Therefore, the focus of this study was to investigate a new combination therapy approach for treating prostate cancer and develop polymeric nanocarriers to facilitate anticancer drug and nucleic acid delivery. It was hypothesized that simultaneously targeting androgen-androgen receptor (AR) and X-linked inhibitor of apoptosis protein (XIAP) signaling pathways would be effective in treating prostate cancer. The effect of bicalutamide (antiandrogen) and embelin (XIAP inhibitor) on the growth of prostate cancer cells in vitro and in vivo was first examined. Embelin induced caspase 3 and 9 activation in LNCaP and C4-2 cells by decreasing XIAP expression and was more potent than bicalutamide in killing prostate tumor cells irrespective of their androgen status. Using a combination of MTT assay and isobologram analyses, combination of bicalutamide and embelin was observed to be cell line and schedule dependent. Since bicalutamide and embelin are extremely hydrophobic, polymeric micelles were fabricated using polyethylene glycol-b-polylactic acid (PEG-b-PLA) copolymer to improve drug solubility. Micellar formulations were found to result in at least 60-fold increase in the aqueous solubility of bicalutamide and embelin. Tumor growth was also effectively regressed upon treatment with bicalutamide, but the extent of tumor regression was significantly higher when bicalutamide was formulated in micelles. To further improve bicalutamide aqueous solubility, a series of novel biodegradable copolymers for the systematic micellar delivery of bicalutamide was designed and synthesized. Flory-Huggins interaction parameter (χFH) was used to assess compatibility between bicalutamide and poly (L-lactide) or poly (carbonate-co-lactide) polymer pairs. Polyethylene glycol-b-poly (carbonate-co-lactide) [PEG-b-P(CB-co-LA)] copolymers were synthesized and characterized by NMR and gel permeation chromatography. Micelles formulated using these copolymers had average diameter of 100 nm and distinct spherical shape. Drug loading studies revealed that adding the carbonate monomer could increase bicalutamide loading. Among the series, drug loading of micelles formulated with PEG-b-P(CB-co-LA) copolymer containing 20 mol% carbonate was about four-fold higher than PEG-b-PLLA and aqueous solubility of bicalutamide increased from 5 to 4000 μg/mL. CMC values for PEG-b-P(CB-co-LA) copolymers was up to 10-fold lower than those of PEG-b-PLLA. Bicalutamide-loaded PEG-b-P(CB-co-LA) micelles showed significant inhibition of LNCaP cell growth in a dose dependent manner which was similar to the methanol solution of free drug. Bicalutamide tends to act as an agonist rather than an antagonist after prolonged treatment. Hence, a second generation antiandrogen ((S)-N-(4-cyano-3-(trifluoromethyl) phenyl)-3-((4-cyanophenyl)(methyl)amino)-2-hydroxy-2-methylpropanamide) (CBDIV17)) was synthesized and its effect in combination with XIAP inhibitors for treating advanced prostate cancer was determined. CBDIV17 was more potent than bicalutamide and inhibited proliferation of C4-2 and LNCaP cells. CBDIV17-induced apoptosis more effectively compared to bicalutamide and significantly inhibited DNA replication. Combination of CBDIV17 and embelin resulted in supra-additive antiproliferative and apoptotic effects. Embelin downregulated AR expression and decreased androgen-mediated AR phosphorylation at Ser81. These hydrophobic drugs were solubilized using micelles prepared using polyethylene glycol-b-poly (carbonate-co-lactide) (PEG-b-p(CB-co-PLA)) copolymer. Combination therapy inhibited prostate tumor growth more effectively compared to control or monotherapy in vivo. The findings reported in this work demonstrate the potential benefit of combination therapy targeting AR and XIAP pathways for treating prostate cancer using polymeric nanocarriers. Systematic chemical tailoring of polymers for improving drug loading as well as efforts made to improve micelle stability through crosslinking also generated insights which can be applied to other drugs and cancer types. Results reported in this study therefore offer a new way of addressing the time old problem of treating cancer. (Abstract shortened by UMI.).

Molecular Characterization of Androgen Independence to Delay Progression to Hormone Refractory Prostate Cancer

DTIC Science & Technology

2005-03-01

inhibitor, bortezomib in combination with TRAIL for induction of differential apoptosis in AD lines (LNCaP) and AI lines (CL 1) (9). 2) use of DETANONOate (NO...free medium and the cells were treated with different concentrations of TRAIL (0, 2.5, 5 and 10 ng/ml), and treated or left untreated with DETANONOate ...of CH-11 (0, 2.5, 5 and 10 ng/ml) (anti-Fas agonist mAb), and treated or left untreated with DETANONOate (1000 gM) for 18 h at 37-C in 5% C02

Adipose Stem Cell-Based Therapeutic Targeting of Residual Androgens in African Americans With Bone-Metastatic Prostate Cancer

DTIC Science & Technology

2013-09-01

survival rate than CA males [3-7]. Socioeconomic and environmental factors, such as diet , access to care, and screening, have been cited as factors...cDNA clone coding for 3α-hydroxysteroid dehydrogenase (3α-HSD) was obtained from Origene. The 3α-HSD, also known as aldo- keto reductase family 1 member...growth of established human prostate LNCaP tumors in nude mice fed a low-fat diet . J Natl Cancer Inst 87: 1456–1462 17. Aronson WJ et al. (1999

3-Bromopyruvate induces rapid human prostate cancer cell death by affecting cell energy metabolism, GSH pool and the glyoxalase system.

PubMed

Valenti, Daniela; Vacca, Rosa A; de Bari, Lidia

2015-12-01

3-bromopyruvate (3-BP) is an anti-tumour drug effective on hepatocellular carcinoma and other tumour cell types, which affects both glycolytic and mitochondrial targets, depleting cellular ATP pool. Here we tested 3-BP on human prostate cancer cells showing, differently from other tumour types, efficient ATP production and functional mitochondrial metabolism. We found that 3-BP rapidly induced cultured androgen-insensitive (PC-3) and androgen-responsive (LNCaP) prostate cancer cell death at low concentrations (IC(50) values of 50 and 70 μM, respectively) with a multimodal mechanism of action. In particular, 3-BP-treated PC-3 cells showed a selective, strong reduction of glyceraldeide 3-phosphate dehydrogenase activity, due to the direct interaction of the drug with the enzyme. Moreover, 3-BP strongly impaired both glutamate/malate- and succinate-dependent mitochondrial respiration, membrane potential generation and ATP synthesis, concomitant with the inhibition of respiratory chain complex I, II and ATP synthase activities. The drastic reduction of cellular ATP levels and depletion of GSH pool, associated with significant increase in cell oxidative stress, were found after 3-BP treatment of PC-3 cells. Interestingly, the activity of both glyoxalase I and II, devoted to the elimination of the cytotoxic methylglyoxal, was strongly inhibited by 3-BP. Both N-acetylcysteine and aminoguanidine, GSH precursor and methylglyoxal scavenger, respectively, prevented 3-BP-induced PC-3 cell death, showing that impaired cell antioxidant and detoxifying capacities are crucial events leading to cell death. The provided information on the multi-target cytotoxic action of 3-BP, finally leading to PC-3 cell necrosis, might be useful for future development of 3-BP as a therapeutic option for prostate cancer treatment.

Autophagosomal Sequestration of Mitochondria as an Indicator of Antiandrogen Therapy Resistance of Prostate Cancer (PCa)

DTIC Science & Technology

2017-11-01

this report are those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so...dependent LNCaP and –independent C4-2 cells are studied first. Autophagy is monitored by cellular fluorescence in cells treated with...sensitive LNCaP cells. Mitophagy in circulating tumor cells (CTCs) isolated from patient blood samples are currently being standardized. 15. SUBJECT TERMS

Linking γ-aminobutyric acid A receptor to epidermal growth factor receptor pathways activation in human prostate cancer.

PubMed

Wu, Weijuan; Yang, Qing; Fung, Kar-Ming; Humphreys, Mitchell R; Brame, Lacy S; Cao, Amy; Fang, Yu-Ting; Shih, Pin-Tsen; Kropp, Bradley P; Lin, Hsueh-Kung

2014-03-05

Neuroendocrine (NE) differentiation has been attributed to the progression of castration-resistant prostate cancer (CRPC). Growth factor pathways including the epidermal growth factor receptor (EGFR) signaling have been implicated in the development of NE features and progression to a castration-resistant phenotype. However, upstream molecules that regulate the growth factor pathway remain largely unknown. Using androgen-insensitive bone metastasis PC-3 cells and androgen-sensitive lymph node metastasis LNCaP cells derived from human prostate cancer (PCa) patients, we demonstrated that γ-aminobutyric acid A receptor (GABA(A)R) ligand (GABA) and agonist (isoguvacine) stimulate cell proliferation, enhance EGF family members expression, and activate EGFR and a downstream signaling molecule, Src, in both PC-3 and LNCaP cells. Inclusion of a GABA(A)R antagonist, picrotoxin, or an EGFR tyrosine kinase inhibitor, Gefitinib (ZD1839 or Iressa), blocked isoguvacine and GABA-stimulated cell growth, trans-phospohorylation of EGFR, and tyrosyl phosphorylation of Src in both PCa cell lines. Spatial distributions of GABAAR α₁ and phosphorylated Src (Tyr416) were studied in human prostate tissues by immunohistochemistry. In contrast to extremely low or absence of GABA(A)R α₁-positive immunoreactivity in normal prostate epithelium, elevated GABA(A)R α₁ immunoreactivity was detected in prostate carcinomatous glands. Similarly, immunoreactivity of phospho-Src (Tyr416) was specifically localized and limited to the nucleoli of all invasive prostate carcinoma cells, but negative in normal tissues. Strong GABAAR α₁ immunoreactivity was spatially adjacent to the neoplastic glands where strong phospho-Src (Tyr416)-positive immunoreactivity was demonstrated, but not in adjacent to normal glands. These results suggest that the GABA signaling is linked to the EGFR pathway and may work through autocrine or paracine mechanism to promote CRPC progression. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Identification and Characterization of ART-27, a Novel Coactivator for the Androgen Receptor N Terminus

PubMed Central

Markus, Steven M.; Taneja, Samir S.; Logan, Susan K.; Li, Wenhui; Ha, Susan; Hittelman, Adam B.; Rogatsky, Inez; Garabedian, Michael J.

2002-01-01

The androgen receptor (AR) is a ligand-regulated transcription factor that stimulates cell growth and differentiation in androgen-responsive tissues. The AR N terminus contains two activation functions (AF-1a and AF-1b) that are necessary for maximal transcriptional enhancement by the receptor; however, the mechanisms and components regulating AR transcriptional activation are not fully understood. We sought to identify novel factors that interact with the AR N terminus from an androgen-stimulated human prostate cancer cell library using a yeast two-hybrid approach designed to identify proteins that interact with transcriptional activation domains. A 157-amino acid protein termed ART-27 was cloned and shown to interact predominantly with the AR153–336, containing AF-1a and a part of AF-1b, localize to the nucleus and increase the transcriptional activity of AR when overexpressed in cultured mammalian cells. ART-27 also enhanced the transcriptional activation by AR153–336 fused to the LexA DNA-binding domain but not other AR N-terminal subdomains, suggesting that ART-27 exerts its effect via an interaction with a defined region of the AR N terminus. ART-27 interacts with AR in nuclear extracts from LNCaP cells in a ligand-independent manner. Interestingly, velocity gradient sedimentation of HeLa nuclear extracts suggests that native ART-27 is part of a multiprotein complex. ART-27 is expressed in a variety of human tissues, including sites of androgen action such as prostate and skeletal muscle, and is conserved throughout evolution. Thus, ART-27 is a novel cofactor that interacts with the AR N terminus and plays a role in facilitating receptor-induced transcriptional activation. PMID:11854421

Identification and characterization of ART-27, a novel coactivator for the androgen receptor N terminus.

PubMed

Markus, Steven M; Taneja, Samir S; Logan, Susan K; Li, Wenhui; Ha, Susan; Hittelman, Adam B; Rogatsky, Inez; Garabedian, Michael J

2002-02-01

The androgen receptor (AR) is a ligand-regulated transcription factor that stimulates cell growth and differentiation in androgen-responsive tissues. The AR N terminus contains two activation functions (AF-1a and AF-1b) that are necessary for maximal transcriptional enhancement by the receptor; however, the mechanisms and components regulating AR transcriptional activation are not fully understood. We sought to identify novel factors that interact with the AR N terminus from an androgen-stimulated human prostate cancer cell library using a yeast two-hybrid approach designed to identify proteins that interact with transcriptional activation domains. A 157-amino acid protein termed ART-27 was cloned and shown to interact predominantly with the AR(153-336), containing AF-1a and a part of AF-1b, localize to the nucleus and increase the transcriptional activity of AR when overexpressed in cultured mammalian cells. ART-27 also enhanced the transcriptional activation by AR(153-336) fused to the LexA DNA-binding domain but not other AR N-terminal subdomains, suggesting that ART-27 exerts its effect via an interaction with a defined region of the AR N terminus. ART-27 interacts with AR in nuclear extracts from LNCaP cells in a ligand-independent manner. Interestingly, velocity gradient sedimentation of HeLa nuclear extracts suggests that native ART-27 is part of a multiprotein complex. ART-27 is expressed in a variety of human tissues, including sites of androgen action such as prostate and skeletal muscle, and is conserved throughout evolution. Thus, ART-27 is a novel cofactor that interacts with the AR N terminus and plays a role in facilitating receptor-induced transcriptional activation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fontenot, Krystal; Naragoni, Srivatcha; Claville, Michelle

Kola acuminate, also known as Bizzy Nut or Kola Nut, is a natural product that contains bioactive chemicals that possess hormonal properties. The purpose of this study was to characterize the putative phytoestrogenic compounds present in Bizzy Nut for estrogenic-like activity. As an initial step, five extracts (E1 - hexane, E2 - ether, E3 - acetone, E4 - methanol and E5 - water) were sequentially generated using solid-liquid phase extraction and their bioactivity was examined in MCF-7, MDA-MB-468 and LNCaP cancer cell models. MTT cell viability, dye exclusion, caspase activity and microscopic assessment of apoptotic cells demonstrated that extracts ofmore » Bizzy were cytotoxic to MCF-7, MDA-MB 468 and LNCaP cells. In MCF-7 cells, the acetone extract (E3) at 100 ppm elicited a potent cytotoxic response with a growth-inhibitory concentration (GI{sub 50}) of 67 ppm. In contrast, E3 stimulated growth in LNCaP cells. The ether extract (E2) showed a dose-dependent cytotoxic response with a GI{sub 50} of 13 ppm in the LNCaP cell line. Examination of the apoptotic response induced by E2 and E3 paralleled the level of cell cytotoxicity observed in both cell lines. The methanol extract (E4) was the only extract that showed a time-, dose-, and estrogen-receptor-dependent stimulation of pS2 gene expression. On the other hand, the acetone extract (E3), which showed the highest degree of cytotoxicity, showed no transcription stimulation of pS2 in MCF-7 cells. Altogether, these data indicate that Bizzy contains unique active hormonal compounds that have specific biological properties that are cell line-dependent.« less

SOCS3 Modulates the Response to Enzalutamide and Is Regulated by Androgen Receptor Signaling and CpG Methylation in Prostate Cancer Cells.

PubMed

Handle, Florian; Erb, Holger H H; Luef, Birgit; Hoefer, Julia; Dietrich, Dimo; Parson, Walther; Kristiansen, Glen; Santer, Frédéric R; Culig, Zoran

2016-06-01

The proinflammatory cytokine IL6 is associated with bad prognosis in prostate cancer and implicated in progression to castration resistance. Suppressor of cytokine signaling 3 (SOCS3) is an IL6-induced negative feedback regulator of the IL6/Janus kinase (JAK)/STAT3 pathway. This study reveals that the SOCS3 promoter is hypermethylated in cancerous regions compared with adjacent benign tissue in prostate cancer using methylation-specific qPCR. A series of in vitro experiments was performed to assess the functional impact of low SOCS3 expression during anti-androgen treatment. Using lentivirus-mediated knockdown, it was demonstrated for the first time that SOCS3 regulates IL6/JAK/STAT3 signaling in androgen receptor-positive LNCaP cells. In addition, SOCS3 mRNA is upregulated by the anti-androgens bicalutamide and enzalutamide. This effect is caused by androgen receptor-mediated suppression of IL6ST and JAK1 expression, which leads to altered STAT3 signaling. Functionally, knockdown of SOCS3 led to enhanced androgen receptor activity after 3 weeks of enzalutamide treatment in an inflammatory setting. Furthermore, the stemness/self-renewal associated genes SOX2 and NANOG were strongly upregulated by the long-term treatment, and modulation of SOCS3 expression was sufficient to counteract this effect. These findings prove that SOCS3 plays an important role during anti-androgen treatment in an inflammatory environment. SOCS3 is frequently inactivated by promoter hypermethylation in prostate cancer, which disrupts the feedback regulation of IL6 signaling and leads to reduced efficacy of enzalutamide in the presence of inflammatory cytokines. Mol Cancer Res; 14(6); 574-85. ©2016 AACR. ©2016 American Association for Cancer Research.

Leptin signaling and apoptotic effects in human prostate cancer cell lines.

PubMed

Samuel-Mendelsohn, Sigal; Inbar, Michal; Weiss-Messer, Esther; Niv-Spector, Leonora; Gertler, Arieh; Barkey, Ronnie J

2011-06-15

Prostate cancer (PCa) progression is often associated with transactivation of the androgen receptor (AR) by endogenous hormones/growth factors. One such factor affecting growth, proliferation, and apoptostis (pro-/anti-) in various cancers is the adipokine leptin. This research studied leptin-induced signaling and apoptosis in androgen sensitive (LNCaP, PC3/AR) and insensitive (PC3, DU145) PCa cell lines. Signaling was studied by immunoblotting in cells overexpressing leptin receptors (LRb), Janus kinase 2 (JAK2), and kinase negative-HER2-YFP cDNAs. Apoptosis was measured by immunoblotting of apoptotic proteins and by Hoechst staining of condensed DNA. Leptin rapidly induced activation of JAK2, STAT3, and MAPK (ERK1/2) signaling cascades; it may also induce HER2 transactivation via leptin-induced phospho-JAK2. Leptin was then shown to exert clear pro-apoptotic effects, increasing levels of caspase 3, cleavage of its substrate, poly (ADP-ribose) polymerase (PARP) to cleaved PARP(89) , levels of CK 18, a cytoskeletal protein formed during apoptosis, and DNA condensation. Kinase inhibitors indicated that leptin-induced apoptosis is probably mediated by balanced activation of JAK2/STAT3, p38 MAPK, and PKC pathways in PCa cells. A human leptin mutein LRb antagonist, L39A/D40A/F41A, fully inhibited leptin-induced phosphorylation of JAK2, ERK1/2, and Akt/PKB, and partially abrogated effects on apoptotic proteins. In LNCaP and PC3/AR cells, leptin increased AR protein levels in correlation with raised apoptotic markers. Thus, AR may mediate, at least partly, the leptin-induced apoptotic response. Leptin can clearly induce apoptosis in human PCa cell lines. These findings could lead to development of new leptin agonists with enhanced pro-apoptotic effects and targeted for use in human PCa. Copyright © 2010 Wiley-Liss, Inc.

Heparin affin regulatory peptide/pleiotrophin mediates fibroblast growth factor 2 stimulatory effects on human prostate cancer cells.

PubMed

Hatziapostolou, Maria; Polytarchou, Christos; Katsoris, Panagiotis; Courty, Jose; Papadimitriou, Evangelia

2006-10-27

Fibroblast growth factor 2 (FGF2) is a pleiotropic growth factor that has been implicated in prostate cancer formation and progression. In the present study we found that exogenous FGF2 significantly increased human prostate cancer LNCaP cell proliferation and migration. Heparin affin regulatory peptide (HARP) or pleiotrophin seems to be an important mediator of FGF2 stimulatory effects, since the latter had no effect on stably transfected LNCaP cells that did not express HARP. Moreover, FGF2, through FGF receptors (FGFRs), significantly induced HARP expression and secretion by LNCaP cells and increased luciferase activity of a reporter gene vector carrying the full-length promoter of HARP gene. Using a combination of Western blot analyses, as well as genetic and pharmacological inhibitors, we found that activation of FGFR by FGF2 in LNCaP cells leads to NAD(P)H oxidase-dependent hydrogen peroxide production, phosphorylation of ERK1/2 and p38, activation of AP-1, increased expression and secretion of HARP, and, finally, increased cell proliferation and migration. These results establish the role and the mode of activity of FGF2 in LNCaP cells and support an interventional role of HARP in FGF2 effects, providing new insights on the interplay among growth factor pathways within prostate cancer cells.

Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract.

PubMed

Konrad, L; Müller, H H; Lenz, C; Laubinger, H; Aumüller, G; Lichius, J J

2000-02-01

In the present study the activity of a 20% methanolic extract of stinging nettle roots (Urtica dioica L., Urticaceae) on the proliferative activity of human prostatic epithelial (LNCaP) and stromal (hPCPs) cells was evaluated using a colorimetric assay. A concentration-dependent and significant (p < 0.05) antiproliferative effect of the extract was observed only on LNCaP cells during 7 days, whereas stromal cell growth remained unaltered. The inhibition was time-dependent with the maximum of growth reduction (30%) at a concentration of 1.0E-6 mg/ml on day 5 compared to the untreated control. On day 4 and 6, the reduction in proliferation of LNCaP cells showed the minimal effective dose at 1.0E-9 mg/ml. No cytotoxic effect of ME-20 on cell proliferation was observed. The antiproliferative effect of ME-20 of stinging nettle roots observed both in an in vivo model and in an in vitro system clearly indicates a biologically relevant effect of compounds present in the extract.

Equol an isoflavonoid: potential for improved prostate health, in vitro and in vivo evidence

PubMed Central

2011-01-01

Background To determine: in vitro binding affinity of equol for 5alpha-dihydrotestosterone (5alpha-DHT), in vitro effects of equol treatment in human prostate cancer (LNCap) cells, and in vivo effects of equol on rat prostate weight and circulating levels of sex steroid hormones. Methods First, in vitro equol binding affinity for 5alpha-DHT was determined using 14C5alpha-DHT combined with cold 5alpha-DHT (3.0 nM in all samples). These steroids were incubated with increasing concentrations of equol (0-2,000 nM) and analyzed by Sephadex LH-20 column chromatography. 14C5alpha-DHT peak/profiles were determined by scintillation counting of column fractions. Using the 14C5alpha-DHT peak (0 nM equol) as a reference standard, a binding curve was generated by quantifying shifts in the 14C5alpha-DHT peaks as equol concentrations increased. Second, equol's in vitro effects on LNCap cells were determined by culturing cells (48 hours) in the presence of increasing concentrations of dimethyl sulfoxide (DMSO) (vehicle-control), 5alpha-DHT, equol or 5alpha-DHT+equol. Following culture, prostate specific antigen (PSA) levels were quantified via ELISA. Finally, the in vivo effects of equol were tested in sixteen male Long-Evans rats fed a low isoflavone diet. From 190-215 days, animals received 0.1cc s.c. injections of either DMSO-control vehicle (n = 8) or 1.0 mg/kg (body weight) of equol (in DMSO) (n = 8). At 215 days, body and prostate weights were recorded, trunk blood was collected and serum assayed for luteinizing hormone (LH), 5alpha-DHT, testosterone and 17beta-estradiol levels. Results Maximum and half maximal equol binding to 5alpha-DHT occurred at approximately 100 nM and 4.8 nM respectively. LNCap cells cultured in the presence of 5alpha-DHT significantly increased PSA levels. However, in the presence of 5alpha-DHT+equol, equol blocked the significant increases in PSA levels from LNCap cells. In vivo equol treatment significantly decreased rat prostate weights and serum 5alpha-DHT levels but did not alter LH, testosterone, and estradiol levels. Conclusions Equol administration appears to have potential beneficial effects for prostate health and other 5alpha-DHT mediated disorders. Equol administration: reduces PSA levels from LNCap cells under 5alpha-DHT stimulation, decreases rat prostate size, decreases serum 5alpha-DHT levels and androgen hormone action, while not altering other circulating sex steroids or LH levels. PMID:21232127

JS-K, a glutathione/glutathione S-transferase-activated nitric oxide releasing prodrug inhibits androgen receptor and WNT-signaling in prostate cancer cells.

PubMed

Laschak, Martin; Spindler, Klaus-Dieter; Schrader, Andres J; Hessenauer, Andrea; Streicher, Wolfgang; Schrader, Mark; Cronauer, Marcus V

2012-03-30

Nitric oxide (NO) and its oxidative reaction products have been repeatedly shown to block steroid receptor function via nitrosation of zinc finger structures in the DNA-binding domain (DBD). In consequence NO-donors could be of special interest for the treatment of deregulated androgen receptor(AR)-signaling in castration resistant prostate cancer (CRPC). Prostate cancer (PCa) cells were treated with JS-K, a diazeniumdiolate derivate capable of generating large amounts of intracellular NO following activation by glutathione S-transferase. Generation of NO was determined indirectly by the detection of nitrate in tissue culture medium or by immunodetection of nitrotyrosine in the cytoplasm. Effects of JS-K on intracellular AR-levels were determined by western blotting. AR-dimerization was analyzed by mammalian two hybrid assay, nuclear translocation of the AR was visualized in PCa cells transfected with a green fluorescent AR-Eos fusion protein using fluorescence microscopy. Modulation of AR- and WNT-signalling by JS-K was investigated using reporter gene assays. Tumor cell proliferation following JS-K treatment was measured by MTT-Assay. The NO-releasing compound JS-K was shown to inhibit AR-mediated reporter gene activity in 22Rv1 CRPC cells. Inhibition of AR signaling was neither due to an inhibition of nuclear import nor to a reduction in AR-dimerization. In contrast to previously tested NO-donors, JS-K was able to reduce the intracellular concentration of functional AR. This could be attributed to the generation of extremely high intracellular levels of the free radical NO as demonstrated indirectly by high levels of nitrotyrosine in JS-K treated cells. Moreover, JS-K diminished WNT-signaling in AR-positive 22Rv1 cells. In line with these observations, castration resistant 22Rv1 cells were found to be more susceptible to the growth inhibitory effects of JS-K than the androgen dependent LNCaP which do not exhibit an active WNT-signaling pathway. Our results suggest that small molecules able to inhibit WNT- and AR-signaling via NO-release represent a promising platform for the development of new compounds for the treatment of CRPC.

JS-K, a glutathione/glutathione S-transferase-activated nitric oxide releasing prodrug inhibits androgen receptor and WNT-signaling in prostate cancer cells

PubMed Central

2012-01-01

Background Nitric oxide (NO) and its oxidative reaction products have been repeatedly shown to block steroid receptor function via nitrosation of zinc finger structures in the DNA-binding domain (DBD). In consequence NO-donors could be of special interest for the treatment of deregulated androgen receptor(AR)-signaling in castration resistant prostate cancer (CRPC). Methods Prostate cancer (PCa) cells were treated with JS-K, a diazeniumdiolate derivate capable of generating large amounts of intracellular NO following activation by glutathione S-transferase. Generation of NO was determined indirectly by the detection of nitrate in tissue culture medium or by immunodetection of nitrotyrosine in the cytoplasm. Effects of JS-K on intracellular AR-levels were determined by western blotting. AR-dimerization was analyzed by mammalian two hybrid assay, nuclear translocation of the AR was visualized in PCa cells transfected with a green fluorescent AR-Eos fusion protein using fluorescence microscopy. Modulation of AR- and WNT-signalling by JS-K was investigated using reporter gene assays. Tumor cell proliferation following JS-K treatment was measured by MTT-Assay. Results The NO-releasing compound JS-K was shown to inhibit AR-mediated reporter gene activity in 22Rv1 CRPC cells. Inhibition of AR signaling was neither due to an inhibition of nuclear import nor to a reduction in AR-dimerization. In contrast to previously tested NO-donors, JS-K was able to reduce the intracellular concentration of functional AR. This could be attributed to the generation of extremely high intracellular levels of the free radical NO as demonstrated indirectly by high levels of nitrotyrosine in JS-K treated cells. Moreover, JS-K diminished WNT-signaling in AR-positive 22Rv1 cells. In line with these observations, castration resistant 22Rv1 cells were found to be more susceptible to the growth inhibitory effects of JS-K than the androgen dependent LNCaP which do not exhibit an active WNT-signaling pathway. Conclusions Our results suggest that small molecules able to inhibit WNT- and AR-signaling via NO-release represent a promising platform for the development of new compounds for the treatment of CRPC. PMID:22462810

Neurotensin is metabolized by endogenous proteases in prostate cancer cell lines.

PubMed

Moody, T W; Mayr, C A; Gillespie, T J; Davis, T P

1998-01-01

The formation and processing of neurotensin (NT) by three prostate cancer cell lines was investigated. Neurotensin (NT) immunoreactivity was detected in conditioned media and extracts of LNCaP cells. Using HPLC techniques, the immunoreactivity extracted from LNCaP cells coeluted with synthetic NT standard. Metalloendopeptidase 3.4.24.15 activity was detected in PC-3, DU-145 and LNCaP cells, whereas high levels of neutral endopeptidase 3.4.24.1 1 activity was detected only in LNCaP cells. NT was relatively stable when incubated with PC-3 or D-145 cells but was rapidly degraded by LNCaP cells to NT1-11 and NT1-10. Phosphoramidon inhibited the metabolism of NT by LNCaP cells. These data suggest that NT is present in and metabolized by LNCaP cellular enzymes.

Pharmacologic basis for the enhanced efficacy of dutasteride against prostatic cancers.

PubMed

Xu, Yi; Dalrymple, Susan L; Becker, Robyn E; Denmeade, Samuel R; Isaacs, John T

2006-07-01

Prostatic dihydrotestosterone (DHT) concentration is regulated by precursors from systemic circulation and prostatic enzymes of androgen metabolism, particularly 5alpha-reductases (i.e., SRD5A1 and SRD5A2). Therefore, the levels of expression SRD5A1 and SRD5A2 and the antiprostatic cancer growth response to finasteride, a selective SRD5A2 inhibitor, versus the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, were compared. Real-time PCR and enzymatic assays were used to determine the levels of SRD5A1 and SRD5A2 in normal versus malignant rat and human prostatic tissues. Rats bearing the Dunning R-3327H rat prostate cancer and nude mice bearing LNCaP or PC-3 human prostate cancer xenografts were used as model systems. Tissue levels of testosterone and DHT were determined using liquid chromatography-mass spectrometry. Prostate cancer cells express undetectable to low levels of SRD5A2 but elevated levels of SRD5A1 activity compared with nonmalignant prostatic tissue. Daily oral treatment of rats with the SRD5A2 selective inhibitor, finasteride, reduces prostate weight and DHT content but did not inhibit R-3327H rat prostate cancer growth or DHT content in intact (i.e., noncastrated) male rats. In contrast, daily oral treatment with even a low 1 mg/kg/d dose of the dual SRD5A1 and SRD5A2 inhibitor, dutasteride, reduces both normal prostate and H tumor DHT content and weight in intact rats while elevating tissue testosterone. Daily oral treatment with finasteride significantly (P < 0.05) inhibits growth of LNCaP human prostate cancer xenografts in intact male nude mice, but this inhibition is not as great as that by equimolar oral dosing with dutasteride. This anticancer efficacy is not equivalent, however, to that produced by castration. Only combination of dutasteride and castration produces a greater tumor inhibition (P < 0.05) than castration monotherapy against androgen-responsive LNCaP cancers. In contrast, no response was induced by dutasteride in nude mice bearing androgen-independent PC-3 human prostatic cancer xenografts. These results document that testosterone is not as potent as DHT but does stimulate prostate cancer growth, thus combining castration with dutasteride enhances therapeutic efficacy.

Induction of cyclo-oxygenase-2 mRNA by prostaglandin E2 in human prostatic carcinoma cells

NASA Technical Reports Server (NTRS)

Tjandrawinata, R. R.; Dahiya, R.; Hughes-Fulford, M.

1997-01-01

Prostaglandins are synthesized from arachidonic acid by the enzyme cyclo-oxygenase. There are two isoforms of cyclooxygenases: COX-1 (a constitutive form) and COX-2 (an inducible form). COX-2 has recently been categorized as an immediate-early gene and is associated with cellular growth and differentiation. The purpose of this study was to investigate the effects of exogenous dimethylprostaglandin E2 (dmPGE2) on prostate cancer cell growth. Results of these experiments demonstrate that administration of dmPGE2 to growing PC-3 cells significantly increased cellular proliferation (as measured by the cell number), total DNA content and endogenous PGE2 concentration. DmPGE2 also increased the steady-state mRNA levels of its own inducible synthesizing enzyme, COX-2, as well as cellular growth to levels similar to those seen with fetal calf serum and phorbol ester. The same results were observed in other human cancer cell types, such as the androgen-dependent LNCaP cells, breast cancer MDA-MB-134 cells and human colorectal carcinoma DiFi cells. In PC-3 cells, the dmPGE2 regulation of the COX-2 mRNA levels was both time dependent, with maximum stimulation seen 2 h after addition, and dose dependent on dmPGE2 concentration, with maximum stimulation seen at 5 microg ml(-1). The non-steroidal anti-inflammatory drug flurbiprofen (5 microM), in the presence of exogenous dmPGE2, inhibited the up-regulation of COX-2 mRNA and PC-3 cell growth. Taken together, these data suggest that PGE2 has a specific role in the maintenance of human cancer cell growth and that the activation of COX-2 expression depends primarily upon newly synthesized PGE2, perhaps resulting from changes in local cellular PGE2 concentrations.

Co-targeting androgen receptor and DNA for imaging and molecular radiotherapy of prostate cancer: in vitro studies.

PubMed

Han, Guang; Kortylewicz, Zbigniew P; Enke, Thomas; Baranowska-Kortylewicz, Janina

2014-12-01

The androgen receptor (AR) axis, the key growth and survival pathway in prostate cancer, remains a prime target for drug development. 5-Radioiodo-3'-O-(17β-succinyl-5α-androstan-3-one)-2'-deoxyuridin-5'-yl phosphate (RISAD-P) is the AR-seeking reagent developed for noninvasive assessment of AR and proliferative status, and for molecular radiotherapy of prostate cancer with Auger electron-emitting radionuclides. RISAD-P radiolabeled with 123I, 124I, and 125I were synthesized using a common stannylated precursor. The cellular uptake, subcellular distribution, and radiotoxicity of 123I-, 124I-, and (125) IRISAD-P were measured in LNCaP, DU145, and PC-3 cell lines expressing various levels of AR. The uptake of RISAD-P by prostate cancer cells is proportional to AR levels and independent of the radionuclide. The intracellular accumulation of radioactivity is directly proportional to the extracellular concentration of RISAD-P and the duration of exposure. Initially, RISAD-P is trapped in the cytoplasm. Within 24 hr, radioactivity is associated exclusively with DNA. The RISAD-P radiotoxicity is determined by the radionuclide; however, the cellular responses are directly proportional to the AR expression levels. LNCaP cells expressing high levels of AR are killed at the rate of up to 60% per day after a brief 1 hr RISAD-P treatment. For the first time, the AR expression in PC-3 and DU 145 cells, generally reported as AR-negative, was quantitated by the ultra sensitive RISAD-P-based method. RISAD-P is a theranostic drug, which targets AR. Its subcellular metabolite participates in DNA synthesis. RISAD-P is a promising candidate for imaging of the AR expression and tumor proliferation as well as molecular radiotherapy of prostate cancer. © 2014 Wiley Periodicals, Inc.

TSA-induced JMJD2B downregulation is associated with cyclin B1-dependent survivin degradation and apoptosis in LNCap cells.

PubMed

Zhu, Shan; Li, Yueyang; Zhao, Li; Hou, Pingfu; Shangguan, Chenyan; Yao, Ruosi; Zhang, Weina; Zhang, Yu; Tan, Jiang; Huang, Baiqu; Lu, Jun

2012-07-01

Histone deacetylase (HDAC) inhibitors are emerging as a novel class of anti-tumor agents and have manifested the ability to induce apoptosis of cancer cells, and a significant number of genes have been identified as potential effectors responsible for HDAC inhibitor-induced apoptosis. However, the mechanistic actions of these HDAC inhibitors in this process remain largely undefined. We here report that the treatment of LNCap prostate cancer cells with HDAC inhibitor trichostatin A (TSA) resulted in downregulation of the Jumonji domain-containing protein 2B (JMJD2B). We also found that the TSA-mediated decrease in survivin expression in LNCap cells was partly attributable to downregulation of JMJD2B expression. This effect was attributable to the promoted degradation of survivin protein through inhibition of Cyclin B1/Cdc2 complex-mediated survivin Thr34 phosphorylation. Consequently, knockdown of JMJD2B enhanced TSA-induced apoptosis by regulating the Cyclin B1-dependent survivin degradation to potentiate the apoptosis pathways. Copyright © 2012 Wiley Periodicals, Inc.

CIP2A is a candidate therapeutic target in clinically challenging prostate cancer cell populations.

PubMed

Khanna, Anchit; Rane, Jayant K; Kivinummi, Kati K; Urbanucci, Alfonso; Helenius, Merja A; Tolonen, Teemu T; Saramäki, Outi R; Latonen, Leena; Manni, Visa; Pimanda, John E; Maitland, Norman J; Westermarck, Jukka; Visakorpi, Tapio

2015-08-14

Residual androgen receptor (AR)-signaling and presence of cancer stem-like cells (SCs) are the two emerging paradigms for clinically challenging castration-resistant prostate cancer (CRPC). Therefore, identification of AR-target proteins that are also overexpressed in the cancer SC population would be an attractive therapeutic approach.Our analysis of over three hundred clinical samples and patient-derived prostate epithelial cultures (PPECs), revealed Cancerous inhibitor of protein phosphatase 2A (CIP2A) as one such target. CIP2A is significantly overexpressed in both hormone-naïve prostate cancer (HN-PC) and CRPC patients . CIP2A is also overexpressed, by 3- and 30-fold, in HN-PC and CRPC SCs respectively. In vivo binding of the AR to the intronic region of CIP2A and its functionality in the AR-moderate and AR-high expressing LNCaP cell-model systems is also demonstrated. Further, we show that AR positively regulates CIP2A expression, both at the mRNA and protein level. Finally, CIP2A depletion reduced cell viability and colony forming efficiency of AR-independent PPECs as well as AR-responsive LNCaP cells, in which anchorage-independent growth is also impaired.These findings identify CIP2A as a common denominator for AR-signaling and cancer SC functionality, highlighting its potential therapeutic significance in the most clinically challenging prostate pathology: castration-resistant prostate cancer.

Antiproliferative effect of a polysaccharide fraction of a 20% methanolic extract of stinging nettle roots upon epithelial cells of the human prostate (LNCaP).

PubMed

Lichius, J J; Lenz, C; Lindemann, P; Müller, H H; Aumüller, G; Konrad, L

1999-10-01

In Germany, plant extracts are often used in the treatment of early stages of benign prostate hyperplasia (BPH). The effects of different concentrations of the polysaccharide fraction of the 20% methanolic extract of stinging nettle roots (POLY-M) on the cellular proliferation of lymph node carcinoma of the prostate (LNCaP) cells were determined by measurement of the genomic DNA content of the samples. All concentrations of POLY-M showed an inhibitory effect on the growth of the LNCaP cells during 7 days except the two lowest concentrations. The reduced proliferation of POLY-M treated LNCaP cells was significantly (p < 0.05) different from the untreated control. The inhibition was time- and concentration-dependent with the maximum suppression (50%) on day 6 and at concentrations of 1.0E-9 and 1.0E-11 mg/ml. No cytotoxic effect of POLY-M on cell proliferation was observed. The in vitro results show for the first time an antiproliferative effect of Urtica compounds on human prostatic epithelium and confirm our previous in vivo findings.

Human osteocalcin and bone sialoprotein mediating osteomimicry of prostate cancer cells: role of cAMP-dependent protein kinase A signaling pathway.

PubMed

Huang, Wen-Chin; Xie, Zhihui; Konaka, Hiroyuki; Sodek, Jaro; Zhau, Haiyen E; Chung, Leland W K

2005-03-15

Osteocalcin and bone sialoprotein are the most abundant noncollagenous bone matrix proteins expressed by osteoblasts. Surprisingly, osteocalcin and bone sialoprotein are also expressed by malignant but not normal prostate epithelial cells. The purpose of this study is to investigate how osteocalcin and bone sialoprotein expression is regulated in prostate cancer cells. Our investigation revealed that (a) human osteocalcin and bone sialoprotein promoter activities in an androgen-independent prostate cancer cell line of LNCaP lineage, C4-2B, were markedly enhanced 7- to 12-fold in a concentration-dependent manner by conditioned medium collected from prostate cancer and bone stromal cells. (b) Deletion analysis of human osteocalcin and bone sialoprotein promoter regions identified cyclic AMP (cAMP)-responsive elements (CRE) as the critical determinants for conditioned medium-mediated osteocalcin and bone sialoprotein gene expression in prostate cancer cells. Consistent with these results, the protein kinase A (PKA) pathway activators forskolin and dibutyryl cAMP and the PKA pathway inhibitor H-89, respectively, increased or repressed human osteocalcin and bone sialoprotein promoter activities. (c) Electrophoretic mobility shift assay showed that conditioned medium-mediated stimulation of human osteocalcin and bone sialoprotein promoter activities occurs through increased interaction between CRE and CRE-binding protein. (d) Conditioned medium was found to induce human osteocalcin and bone sialoprotein promoter activities via increased CRE/CRE-binding protein interaction in a cell background-dependent manner, with marked stimulation in selected prostate cancer but not bone stromal cells. Collectively, these results suggest that osteocalcin and bone sialoprotein expression is coordinated and regulated through cAMP-dependent PKA signaling, which may define the molecular basis of the osteomimicry exhibited by prostate cancer cells.

Inappropriate activation of the androgen receptor by nonsteroids: involvement of the Src kinase pathway and its therapeutic implications.

PubMed

Desai, Sonal J; Ma, Ai-Hong; Tepper, Clifford G; Chen, Hong-Wu; Kung, Hsing-Jien

2006-11-01

The inappropriate activation of androgen receptor (AR) by nonsteroids is considered a potential mechanism in the emergence of hormone-refractory prostate tumors, but little is known about the properties of these "pseudoactivated" AR. Here, we present the first comprehensive analysis closely examining the properties of AR activated by the neuropeptide bombesin that distinguish it from androgen-activated AR. We show that bombesin-activated AR (a) is required for bombesin-induced growth of LNCaP cells, (b) has a transcriptional profile overlapping with, but not identical to, androgen-activated AR, (c) activates prostate-specific antigen by preferentially binding to its proximal promoter, and (d) assembles a distinct coactivator complex. Significantly, we found that Src kinase is critical for bombesin-induced AR-mediated activity and is required for translocation and transactivation of AR. Additionally, we identify c-Myc, a Src target gene, to be activated by bombesin and a potential coactivator of AR-mediated activity specific to bombesin-induced signaling. Because Src kinase is often activated by other nonsteroids, such as other neuropeptides, growth factors, chemokines, and cytokines, our findings have general applicability and provide rationale for investigating the efficacy of the Src kinase pathway as a target for the prevention of relapsed prostate cancers.

A Vitex agnus-castus extract inhibits cell growth and induces apoptosis in prostate epithelial cell lines.

PubMed

Weisskopf, M; Schaffner, W; Jundt, G; Sulser, T; Wyler, S; Tullberg-Reinert, H

2005-10-01

Extracts of Vitex agnus-castus fruits (VACF) are described to have beneficial effects on disorders related to hyperprolactinemia (cycle disorders, premenstrual syndrome). A VACF extract has recently been shown to exhibit antitumor activities in different human cancer cell lines. In the present study, we explored the antiproliferative effects of a VACF extract with a particular focus on apoptosis-inducing and potential cytotoxic effects. Three different human prostate epithelial cell lines (BPH-1, LNCaP, PC-3) representing different disease stages and androgen responsiveness were chosen. The action of VACF on cell viability was assessed using the WST-8-tetrazolium assay. Cell proliferation in cells receiving VACF alone or in combination with a pan-caspase inhibitor (Z-VAD-fmk) was quantified using a Crystal Violet assay. Flow cytometric cell cycle analysis and measurement of DNA fragmentation using an ELISA method were used for studying the induction of apoptosis. Lactate dehydrogenase (LDH) activity was determined as a marker of cytotoxicity. The extract inhibited proliferation of all three cell lines in a concentration-dependent manner with IC (50) values below 10 microg/mL after treatment for 48 h. Cell cycle analysis and DNA fragmentation assays suggest that part of the cells were undergoing apoptosis. The VACF-induced decrease in cell number was partially inhibited by Z-VAD-fmk, indicating a caspase-dependent apoptotic cell death. However, the concentration-dependent LDH activity of VACF treated cells indicated cytotoxic effects as well. These data suggest that VACF contains components that inhibit proliferation and induce apoptosis in human prostate epithelial cell lines. The extract may be useful for the prevention and/or treatment not only of benign prostatic hyperplasia but also of human prostate cancer.

Epidermal growth factor increases LRF/Pokemon expression in human prostate cancer cells.

PubMed

Aggarwal, Himanshu; Aggarwal, Anshu; Agrawal, Devendra K

2011-10-01

Leukemia/lymphoma related factor/POK erythroid myeloid ontogenic factor (LRF/Pokemon) is a member of the POK family of proteins that promotes oncogenesis in several forms of cancer. Recently, we found higher LRF expression in human breast and prostate carcinomas compared to the corresponding normal tissues. The aim of this study was to examine the regulation of LRF expression in human prostate cells. Epidermal growth factor (EGF) and its receptors mediate several tumorigenic cascades that regulate cell differentiation, proliferation, migration and survival of prostate cancer cells. There was significantly higher level of LRF expression in the nucleus of LNCaP and PC-3 cells than RWPE-1 cells. A significant increase in LRF expression was observed with increasing doses of EGF in more aggressive and androgen-sensitive prostate cancer cells suggesting that EGF signaling pathway is critical in upregulating the expression of LRF/Pokemon to promote oncogenesis. Copyright © 2011 Elsevier Inc. All rights reserved.

Epidermal Growth Factor Increases LRF/Pokemon Expression in Human Prostate Cancer Cells

PubMed Central

Aggarwal, Himanshu; Aggarwal, Anshu; Agrawal, Devendra K.

2011-01-01

Leukemia/lymphoma related factor/POK erythroid myeloid ontogenic factor (LRF/Pokemon) is a member of the POK family of proteins that promotes oncogenesis in several forms of cancer. Recently, we found higher LRF expression in human breast and prostate carcinomas compared to the corresponding normal tissues. The aim of this study was to examine the regulation of LRF expression in human prostate cells. Epidermal growth factor (EGF) and its receptors mediate several tumorigenic cascades that regulate cell differentiation, proliferation, migration and survival of prostate cancer cells. There was significantly higher level of LRF expression in the nucleus of LNCaP and PC-3 cells than RWPE-1 cells. A significant increase in LRF expression was observed with increasing doses of EGF in more aggressive and androgen-sensitive prostate cancer cells suggesting that EGF signaling pathway is critical in upregulating the expression of LRF/Pokemon to promote oncogenesis. PMID:21640721

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo

PubMed Central

Wang, Piwen; Solorzano, Walter; Diaz, Tanya; Magyar, Clara E.; Henning, Susanne M.; Vadgama, Jaydutt V.

2017-01-01

The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa, has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (< 2μM) significantly inhibited the proliferation of LNCaP and LAPC-4 cells by 30-50% at 48h compared to control, and inhibited WPE1-NA22 cells by 75%, while did not affect normal prostate epithelial cells. Male severe combined immunodeficiency (SCID) mice were implanted subcutaneously with LAPC-4 cells for in vivo studies. In one experiment, the intervention started one week after tumor implantation. Mice received arctigenin at 50mg/kg (LD) or 100mg/kg (HD) b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD) and 70% (HD) compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo, which provides a high promise in its translation to human application. PMID:29062885

Arctigenin inhibits prostate tumor cell growth in vitro and in vivo.

PubMed

Wang, Piwen; Solorzano, Walter; Diaz, Tanya; Magyar, Clara E; Henning, Susanne M; Vadgama, Jaydutt V

2017-06-01

The low bioavailability of most phytochemicals limits their translation to humans. We investigated whether arctigenin, a novel anti-inflammatory lignan from the seeds of Arctium lappa , has favorable bioavailability/potency against prostate cancer. The anticarcinogenic activity of arctigenin was investigated both in vitro using the androgen-sensitive LNCaP and LAPC-4 human prostate cancer cells and pre-malignant WPE1-NA22 cells, and in vivo using xenograft mouse models. Arctigenin at lower doses (< 2μM) significantly inhibited the proliferation of LNCaP and LAPC-4 cells by 30-50% at 48h compared to control, and inhibited WPE1-NA22 cells by 75%, while did not affect normal prostate epithelial cells. Male severe combined immunodeficiency (SCID) mice were implanted subcutaneously with LAPC-4 cells for in vivo studies. In one experiment, the intervention started one week after tumor implantation. Mice received arctigenin at 50mg/kg (LD) or 100mg/kg (HD) b.w. daily or vehicle control by oral gavage. After 6 weeks, tumor growth was inhibited by 50% (LD) and 70% (HD) compared to control. A stronger tumor inhibitory effect was observed in a second experiment where arctigenin intervention started two weeks prior to tumor implantation. Arc was detectable in blood and tumors in Arc groups, with a mean value up to 2.0 μM in blood, and 8.3 nmol/g tissue in tumors. Tumor levels of proliferation marker Ki67, total and nuclear androgen receptor, and growth factors including VEGF, EGF, and FGF-β were significantly decreased by Arc, along with an increase in apoptosis marker of Bax/Bcl-2 ratio. Genes responsive to arctigenin were identified including TIMP3 and ZNF185, and microRNAs including miR-126-5p, and miR-21-5p. This study provides the first in vivo evidence of the strong anticancer activity of arctigenin in prostate cancer. The effective dose of arctigenin in vitro is physiologically achievable in vivo , which provides a high promise in its translation to human application.

TET2 binds the androgen receptor and loss is associated with prostate cancer

PubMed Central

Nickerson, ML; Das, S; Im, KM; Turan, S; Berndt, SI; Li, H; Lou, H; Brodie, SA; Billaud, JN; Zhang, T; Bouk, AJ; Butcher, D; Wang, Z; Sun, L; Misner, K; Tan, W; Esnakula, A; Esposito, D; Huang, WY; Hoover, RN; Tucker, MA; Keller, JR; Boland, J; Brown, K; Anderson, SK; Moore, LE; Isaacs, WB; Chanock, SJ; Yeager, M; Dean, M; Andresson, T

2016-01-01

Genetic alterations associated with prostate cancer (PCa) may be identified by sequencing metastatic tumor genomes to identify molecular markers at this lethal stage of disease. Previously, we characterized somatic alterations in metastatic tumors in the methylcytosine dioxygenase ten-eleven translocation 2 (TET2), which is altered in 5–15% of myeloid, kidney, colon and prostate cancers. Genome-wide association studies previously identified non-coding risk variants associated with PCa and melanoma. We performed fine-mapping of PCa risk across TET2 using genotypes from the PEGASUS case-control cohort and identified six new risk variants in introns 1 and 2. Oligonucleotides containing two risk variants were bound by the transcription factor octamer-binding protein 1 (Oct1/POU2F1) and TET2 and Oct1 expression were positively correlated in prostate tumors. TET2 is expressed in normal prostate tissue and reduced in a subset of tumors from the Cancer Genome Atlas (TCGA). Small interfering RNA (siRNA)-mediated TET2 knockdown (KD) increases LNCaP cell proliferation, migration, and wound healing, verifying loss drives a cancer phenotype. Endogenous TET2 bound the androgen receptor (AR) and AR-coactivator proteins in LNCaP cell extracts, and TET2 KD increases prostate-specific antigen (KLK3/PSA) expression. Published data reveal TET2 binding sites and hydroxymethylcytosine (hmC) proximal to KLK3. A gene co-expression network identified using TCGA prostate tumor RNA-sequencing identifies co-regulated cancer genes associated with 2-oxoglutarate (2-OG) and succinate metabolism, including TET2, lysine demethylase (KDM) KDM6A, BRCA1-associated BAP1, and citric acid cycle enzymes IDH1/2, SDHA/B, and FH. The co-expression signature is conserved across 31 TCGA cancers suggesting a putative role for TET2 as an energy sensor (of 2-OG) that modifies aspects of androgen-AR signaling. Decreased TET2 mRNA expression in TCGA PCa tumors is strongly associated with reduced patient survival indicating reduced expression in tumors maybe an informative biomarker of disease progression and perhaps metastatic disease. PMID:27819678

Myofibroblast androgen receptor expression determines cell survival in co-cultures of myofibroblasts and prostate cancer cells in vitro.

PubMed

Palethorpe, Helen M; Leach, Damien A; Need, Eleanor F; Drew, Paul A; Smith, Eric

2018-04-10

Fibroblasts express androgen receptor (AR) in the normal prostate and during prostate cancer development. We have reported that loss of AR expression in prostate cancer-associated fibroblasts is a poor prognostic indicator. Here we report outcomes of direct and indirect co-cultures of immortalised AR-positive (PShTert-AR) or AR-negative (PShTert) myofibroblasts with prostate cancer cells. In the initial co-cultures the AR-negative PC3 cell line was used so AR expression and signalling were restricted to the myofibroblasts. In both direct and indirect co-culture with PShTert-AR myofibroblasts, paracrine signalling to the PC3 cells slowed proliferation and induced apoptosis. In contrast, PC3 cells proliferated with PShTert myofibroblasts irrespective of the co-culture method. In direct co-culture PC3 cells induced apoptosis in and destroyed PShTerts by direct signalling. Similar results were seen in direct co-cultures with AR-negative DU145 and AR-positive LNCaP and C4-2B prostate cancer cell lines. The AR ligand 5α-dihydrotestosterone (DHT) inhibited the proliferation of the PShTert-AR myofibroblasts, thereby reducing the extent of their inhibitory effect on cancer cell growth. These results suggest loss of stromal AR would favour prostate cancer cell growth in vivo , providing an explanation for the clinical observation that reduced stromal AR is associated with a poorer outcome.

Myofibroblast androgen receptor expression determines cell survival in co-cultures of myofibroblasts and prostate cancer cells in vitro

PubMed Central

Palethorpe, Helen M.; Leach, Damien A.; Need, Eleanor F.; Drew, Paul A.; Smith, Eric

2018-01-01

Fibroblasts express androgen receptor (AR) in the normal prostate and during prostate cancer development. We have reported that loss of AR expression in prostate cancer-associated fibroblasts is a poor prognostic indicator. Here we report outcomes of direct and indirect co-cultures of immortalised AR-positive (PShTert-AR) or AR-negative (PShTert) myofibroblasts with prostate cancer cells. In the initial co-cultures the AR-negative PC3 cell line was used so AR expression and signalling were restricted to the myofibroblasts. In both direct and indirect co-culture with PShTert-AR myofibroblasts, paracrine signalling to the PC3 cells slowed proliferation and induced apoptosis. In contrast, PC3 cells proliferated with PShTert myofibroblasts irrespective of the co-culture method. In direct co-culture PC3 cells induced apoptosis in and destroyed PShTerts by direct signalling. Similar results were seen in direct co-cultures with AR-negative DU145 and AR-positive LNCaP and C4-2B prostate cancer cell lines. The AR ligand 5α-dihydrotestosterone (DHT) inhibited the proliferation of the PShTert-AR myofibroblasts, thereby reducing the extent of their inhibitory effect on cancer cell growth. These results suggest loss of stromal AR would favour prostate cancer cell growth in vivo, providing an explanation for the clinical observation that reduced stromal AR is associated with a poorer outcome. PMID:29721186

Syndecan-1 responsive microRNA-126 and 149 regulate cell proliferation in prostate cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fujii, Tomomi; Shimada, Keiji; Tatsumi, Yoshihiro

2015-01-02

Highlights: • Syndecan-1 is highly expressed in androgen independent prostate cancer cells, PC3. • Syndecan-1 regulates the expression of miR-126 and -149 in prostate cancer cells. • MiR-126 and 149 control cell growth via p21 induction and senescence mechanism. • MiR-126 and 149 promote cell proliferation by suppressing SOX2, NANOG, and Oct4. - Abstract: MicroRNAs (miRNAs) are short (19–24 nt), low molecular weight RNAs that play important roles in the regulation of target genes associated with cell proliferation, differentiation, and development, by binding to the 3′-untranslated region of the target mRNAs. In this study, we examined the expression of miRNA-126more » (miR-126) and miR-149 in prostate cancer, and investigated the molecular mechanisms by which they affect syndecan-1 in prostate cancer. Functional analysis of miR-126 and miR-149 was conducted in the prostate cancer cell lines, PC3, Du145, and LNCaP. The expression levels of SOX2, NANOG, Oct4, miR-126 and miR-149 were evaluated by quantitative RT-PCR. After silencing syndecan-1, miR-126, and/or miR-149 in the PC3 cells, cell proliferation, senescence, and p21 induction were assessed using the MTS assay, senescence-associated β-galactosidase (SA-β-Gal) assay, and immunocytochemistry, respectively. Compared to the Du145 and LNCaP cells, PC3 cells exhibited higher expression of syndecan-1. When syndecan-1 was silenced, the PC3 cells showed reduced expression of miR-126 and miR-149 most effectively. Suppression of miR-126 and/or miR-149 significantly inhibited cell growth via p21 induction and subsequently, induced senescence. The mRNA expression levels of SOX2, NANOG, and Oct4 were significantly increased in response to the silencing of miR-126 and/or miR-149. Our results suggest that miR-126 and miR-149 are associated with the expression of syndecan-1 in prostate cancer cells. These miRNAs promote cell proliferation by suppressing SOX2, NANOG, and Oct4. The regulation of these factors by miR-126 and miR-149 is essential for syndecan-1-mediated development of androgen-refractory prostate cancer.« less

ELEVATION OF C-FLIP IN CASTRATE-RESISTANT PROSTATE CANCER ANTAGONIZES THERAPEUTIC RESPONSE TO ANDROGEN-RECEPTOR TARGETED THERAPY

PubMed Central

McCourt, Clare; Maxwell, Pamela; Mazzucchelli, Roberta; Montironi, Rodolfo; Scarpelli, Marina; Salto-Tellez, Manuel; O’Sullivan, Joe M.; Longley, Daniel B.; Waugh, David J.J.

2012-01-01

Purpose To characterize the importance of cellular Fas-associated death domain (FADD)-like interleukin 1β-converting enzyme (FLICE) inhibitory protein (c-FLIP), a key regulator of caspase 8 (FLICE)-promoted apoptosis, in modulating the response of prostate cancer (CaP) cells to androgen receptor (AR)-targeted therapy. Experimental Design c-FLIP expression was characterized by immunohistochemical analysis of prostatectomy tissue. The functional importance of c-FLIP to survival and modulating response to bicalutamide was studied by molecular and pharmacological interventions. Results c-FLIP expression was increased in high-grade prostatic intra-epithelial neoplasia (HGPIN) and CaP tissue relative to normal prostate epithelium (P<0.001). Maximal c-FLIP expression was detected in castrate-resistant CaP (CRPC) (P<0.001). In vitro, silencing of c-FLIP induced spontaneous apoptosis and increased 22Rv1 and LNCaP cell sensitivity to bicalutamide, determined by flow cytometry, PARP cleavage and caspase activity assays. The histone deacetylase inhibitors (HDACi), droxinostat and SAHA, also down-regulated c-FLIP expression, induced caspase-8 and caspase-3/7 mediated apoptosis and increased apoptosis in bicalutamide-treated cells. Conversely, the elevated expression of c-FLIP detected in the CRPC cell line VCaP underpinned their insensitivity to bicalutamide and SAHA in vitro. However, knockdown of c-FLIP induced spontaneous apoptosis in VCaP cells, indicating its relevance to cell survival and therapeutic resistance. Conclusion c-FLIP reduces the efficacy of AR-targeted therapy and maintains the viability of CaP cells. A combination of HDACi with androgen-deprivation therapy (ADT) may be effective in early-stage disease, using c-FLIP expression as a predictive biomarker of sensitivity. Direct targeting of c-FLIP however may be relevant to enhance the response of existing and novel therapeutics in CRPC. PMID:22623731

Rosemary (Rosmarinus officinalis) extract modulates CHOP/GADD153 to promote androgen receptor degradation and decreases xenograft tumor growth.

PubMed

Petiwala, Sakina M; Berhe, Saba; Li, Gongbo; Puthenveetil, Angela G; Rahman, Ozair; Nonn, Larisa; Johnson, Jeremy J

2014-01-01

The Mediterranean diet has long been attributed to preventing or delaying the onset of cardiovascular disease, diabetes and various solid organ cancers. In this particular study, a rosemary extract standardized to carnosic acid was evaluated for its potential in disrupting the endoplasmic reticulum machinery to decrease the viability of prostate cancer cells and promote degradation of the androgen receptor. Two human prostate cancer cell lines, 22Rv1 and LNCaP, and prostate epithelial cells procured from two different patients undergoing radical prostatectomy were treated with standardized rosemary extract and evaluated by flow cytometry, MTT, BrdU, Western blot and fluorescent microscopy. A significant modulation of endoplasmic reticulum stress proteins was observed in cancer cells while normal prostate epithelial cells did not undergo endoplasmic reticulum stress. This biphasic response suggests that standardized rosemary extract may preferentially target cancer cells as opposed to "normal" cells. Furthermore, we observed standardized rosemary extract to decrease androgen receptor expression that appears to be regulated by the expression of CHOP/GADD153. Using a xenograft tumor model we observed standardized rosemary extract when given orally to significantly suppress tumor growth by 46% compared to mice not receiving standardized rosemary extract. In the last several years regulatory governing bodies (e.g. European Union) have approved standardized rosemary extracts as food preservatives. These results are especially significant as it is becoming more likely that individuals will be receiving standardized rosemary extracts that are a part of a natural preservative system in various food preparations. Taken a step further, it is possible that the potential benefits that are often associated with a "Mediterranean Diet" in the future may begin to extend beyond the Mediterranean diet as more of the population is consuming standardized rosemary extracts.

Lipid catabolism via CPT1 as a therapeutic target for prostate cancer

PubMed Central

Schlaepfer, Isabel R.; Rider, Leah; Rodrigues, Lindsey Ulkus; Gijón, Miguel A.; Pac, Colton T.; Romero, Lina; Cimic, Adela; Sirintrapun, S. Joseph; Glodé, L. Michael; Eckel, Robert H.; Cramer, Scott D.

2014-01-01

Prostate cancer (PCa) is the most commonly diagnosed malignancy among western men and accounts for the second leading cause of cancer-related deaths. PCa tends to grow slowly and recent studies suggest that it relies on lipid fuel more than on aerobic glycolysis. However, the biochemical mechanisms governing the relationships between lipid synthesis, lipid utilization, and cancer growth remain unknown. To address the role of lipid metabolism in PCa we have used Etomoxir and Orlistat, clinically safe drugs that block lipid oxidation and lipid synthesis/lipolysis, respectively. Etomoxir is an irreversible inhibitor of the carnitine palmitoyltransferase (CPT1) enzyme that decreases beta oxidation in the mitochondria. Combinatorial treatments using Etomoxir and Orlistat resulted in synergistic decreased viability in LNCaP, VCaP and patient-derived benign and PCa cells. These effects were associated with decreased androgen receptor (AR) expression, decreased mammalian target of Rapamycin (mTOR) signaling and increased caspase-3 activation. Knockdown of CPT1A enzyme in LNCaP cells resulted in decreased palmitate oxidation but increased sensitivity to Etomoxir, with inactivation of AKT kinase and activation of caspase-3. Systemic treatment with Etomoxir in nude nice resulted in decreased xenograft growth over 21 days, underscoring the therapeutic potential of blocking lipid catabolism to decrease PCa tumor growth. PMID:25122071

Transcriptional up-regulation of the human androgen receptor by androgen in bone cells.

PubMed

Wiren, K M; Zhang, X; Chang, C; Keenan, E; Orwoll, E S

1997-06-01

Androgen regulation of androgen receptor (AR) expression has been observed in a variety of tissues, generally as inhibition, and is thought to attenuate cellular responses to androgen. AR is expressed in osteoblasts, the bone-forming cell, suggesting direct actions of androgens on bone. Here we characterized the effect of androgen exposure on AR gene expression in human osteoblastic SaOS-2 and U-2 OS cells. Treatment of osteoblastic cells with the nonaromatizable androgen 5alpha-dihydrotestosterone increased AR steady state messenger RNA levels in a time- and dose-dependent fashion. Reporter assays with 2.3 kilobases of the proximal 5'-flanking region of the human AR promoter linked to the chloramphenicol acetyltransferase gene in transfected cultures showed that up-regulation of AR promoter activity by androgen was time and dose dependent. Treatment with other steroid hormones, including progesterone, 17beta-estradiol, and dexamethasone, was without effect. The antiandrogen hydroxyflutamide completely antagonized androgen up-regulation. Thus, in contrast to many other androgen target tissues, androgen exposure increases steady state AR messenger RNA levels in osteoblasts. This regulation occurs at least partially at the level of transcription, is mediated by the 5'-promoter region of the AR gene, and is dependent on functional AR. These results suggest that physiological concentrations of androgens have significant effects on AR expression in skeletal tissue.

Auraptene Induces Apoptosis via Myeloid Cell Leukemia 1-Mediated Activation of Caspases in PC3 and DU145 Prostate Cancer Cells.

PubMed

Lee, Jae Chul; Shin, Eun Ah; Kim, Bonglee; Kim, Bo-Im; Chitsazian-Yazdi, Mahsa; Iranshahi, Mehrdad; Kim, Sung-Hoon

2017-06-01

Although auraptene, a prenyloxy coumarin from Citrus species, was known to have anti-oxidant, anti-bacterial, antiinflammatory, and anti-tumor activities, the underlying anti-tumor mechanism of auraptene in prostate cancers is not fully understood to date. Thus, in the present study, we have investigated the anti-tumor mechanism of auraptene mainly in PC3 and DU145 prostate cancer cells, because auraptene suppressed the viability of androgen-independent PC3 and DU145 prostate cancer cells better than androgen-sensitive LNCaP cells. Also, auraptene notably increased sub-G1 cell population and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells as features of apoptosis in two prostate cancer cells compared with untreated control. Consistently, auraptene cleaved poly(ADP-ribose) polymerase, activated caspase-9 and caspase-3, suppressed the expression of anti-apoptotic proteins, including Bcl-2 and myeloid cell leukemia 1 (Mcl-1), and also activated pro-apoptotic protein Bax in both prostate cancer cells. However, Mcl-1 overexpression reversed the apoptotic effect of auraptene to increase sub-G1 population and induce caspase-9/3 in both prostate cancer cells. Taken together, the results support scientific evidences that auraptene induces apoptosis in PC3 and DU145 prostate cancer cells via Mcl-1-mediated activation of caspases as a potent chemopreventive agent for prostate cancer prevention and treatment. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

In vitro regulation of pericellular proteolysis in prostatic tumor cells treated with bombesin.

PubMed

Festuccia, C; Guerra, F; D'Ascenzo, S; Giunciuglio, D; Albini, A; Bologna, M

1998-01-30

Bombesin is a potent inducer of signal trasduction pathways involved in the proliferation and invasion of androgen-insensitive prostatic tumor cells. This study examines the bombesin-mediated modulation of pericellular proteolysis, monitoring cell capability to migrate and invade basement membranes, using a chemo-invasion assay and analyzing protease production. The results suggest that bombesin could modulate the invasive potential of prostatic cell lines regulating secretion and cell-surface uptake of uPA and MMP-9 activation. In fact, in PC3 and DU145 cells but not in LNCaP cells, urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) are induced by bombesin treatment. Bombesin also stimulates cell proliferation and this effect can be inhibited blocking uPA by antibodies and/or uPA inhibitor p-aminobenzamidine. Moreover, HMW-uPA induces cell proliferation in LNCaP cells, which do not produce uPA in the basal conditions, while PC3 and DU145 cell growth is supported by autocrine production of uPA. The increment of uPA activity on the external plasma membrane causes an increased pericellular plasmin activation. This effect is inhibited by antibodies against uPA and by p-aminobenzamidine. Similarly to EGF, bombesin stimulates secretion and activation of MMP-9 and TIMP-1 production. MMP-9 activation can be also obtained by HMW-uPA treatment, suggesting that plasma-membrane-bound uPA can start a proteolytic cascade involving MMP-9. Therefore, in in vitro assays, bombesin is able to modulate pericellular proteolysis and cell proliferation, differently distributing and activating proteolytic activities. This effect can be related to the "non-random" degradation of the extracellular matrix in which membrane uPA-uPAreceptor complexes could start bombesin-induced directional protein degradation during metastatic spread.

Anti-Neoplastic Activity of Two Flavone Isomers Derived from Gnaphalium elegans and Achyrocline bogotensis

PubMed Central

Pendleton, Morgan H.; Torrenegra, Ruben D.; Rodriguez, Oscar E.; Harirforoosh, Sam; Ballester, Maria; Lightner, Janet; Krishnan, Koyamangalath; Ramsauer, Victoria P.

2012-01-01

Over 4000 flavonoids have been identified so far and among these, many are known to have antitumor activities. The basis of the relationships between chemical structures, type and position of substituent groups and the effects these compounds exert specifically on cancer cells are not completely elucidated. Here we report the differential cytotoxic effects of two flavone isomers on human cancer cells from breast (MCF7, SK-BR-3), colon (Caco-2, HCT116), pancreas (MIA PaCa, Panc 28), and prostate (PC3, LNCaP) that vary in differentiation status and tumorigenic potential. These flavones are derived from plants of the family Asteraceae, genera Gnaphalium and Achyrocline reputed to have anti-cancer properties. Our studies indicate that 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays potent activity against more differentiated carcinomas of the colon (Caco-2), and pancreas (Panc28), whereas 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) cytototoxic action is observed on poorly differentiated carcinomas of the colon (HCT116), pancreas (Mia PaCa), and breast (SK-BR3). Both flavones induced cell death (>50%) as proven by MTT cell viability assay in these cancer cell lines, all of which are regarded as highly tumorigenic. At the concentrations studied (5–80 µM), neither flavone demonstrated activity against the less tumorigenic cell lines, breast cancer MCF-7 cells, androgen-responsive LNCaP human prostate cancer line, and androgen-unresponsive PC3 prostate cancer cells. 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5,7-dihydroxy-3,6,8-trimethoxy flavone) displays activity against more differentiated carcinomas of the colon and pancreas, but minimal cytotoxicity on poorly differentiated carcinomas of these organs. On the contrary, 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3,5-dihydroxy-6,7,8-trimethoxy flavone) is highly cytotoxic to poorly differentiated carcinomas of the colon, pancreas, and breast with minimal activity against more differentiated carcinomas of the same organs. These differential effects suggest activation of distinct apoptotic pathways. In conclusion, the specific chemical properties of these two flavone isomers dictate mechanistic properties which may be relevant when evaluating biological responses to flavones. PMID:22768128

SHBG Is an Important Factor in Stemness Induction of Cells by DHT In Vitro and Associated with Poor Clinical Features of Prostate Carcinomas

PubMed Central

Ma, Yuanyuan; Liang, Dongming; Liu, Jian; Wen, Jian-Guo; Servoll, Einar; Waaler, Gudmund; Sæter, Thorstein; Axcrona, Karol; Vlatkovic, Ljiljana; Axcrona, Ulrika; Paus, Elisabeth; Yang, Yue; Zhang, Zhiqian; Kvalheim, Gunnar; Nesland, Jahn M.; Suo, Zhenhe

2013-01-01

Androgen plays a vital role in prostate cancer development. However, it is not clear whether androgens influence stem-like properties of prostate cancer, a feature important for prostate cancer progression. In this study, we show that upon DHT treatment in vitro, prostate cancer cell lines LNCaP and PC-3 were revealed with higher clonogenic potential and higher expression levels of stemness related factors CD44, CD90, Oct3/4 and Nanog. Moreover, sex hormone binding globulin (SHBG) was also simultaneously upregulated in these cells. When the SHBG gene was blocked by SHBG siRNA knock-down, the induction of Oct3/4, Nanog, CD44 and CD90 by DHT was also correspondingly blocked in these cells. Immunohistochemical evaluation of clinical samples disclosed weakly positive, and areas negative for SHBG expression in the benign prostate tissues, while most of the prostate carcinomas were strongly positive for SHBG. In addition, higher levels of SHBG expression were significantly associated with higher Gleason score, more seminal vesicle invasions and lymph node metastases. Collectively, our results show a role of SHBG in upregulating stemness of prostate cancer cells upon DHT exposure in vitro, and SHBG expression in prostate cancer samples is significantly associated with poor clinicopathological features, indicating a role of SHBG in prostate cancer progression. PMID:23936228

Hepatoma-derived growth factor: A survival-related protein in prostate oncogenesis and a potential target for vitamin K2.

PubMed

Shetty, Aditya; Dasari, Subramanyam; Banerjee, Souresh; Gheewala, Taher; Zheng, Guoxing; Chen, Aoshuang; Kajdacsy-Balla, Andre; Bosland, Maarten C; Munirathinam, Gnanasekar

2016-11-01

Hepatoma-derived growth factor (HDGF) is a heparin-binding growth factor, which has previously been shown to be expressed in a variety of cancers. HDGF overexpression has also previously been correlated with a poor prognosis in several cancers. The significance of HDGF in prostate cancer, however, has not been investigated. Here, we show that HDGF is overexpressed in both androgen-sensitive LNCaP cells and androgen-insensitive DU145, 22RV1, and PC-3 cells. Forced overexpression enhanced cell viability of RWPE-1 cells, whereas HDGF knockdown reduced cell proliferation in human prostate cancer cells. We also show that HDGF may serve as a survival-related protein as ectopic overexpression of HDGF in RWPE cells up-regulated the expression of antiapoptosis proteins cyclin E and BCL-2, whereas simultaneously down-regulating proapoptotic protein BAX. Western blot analysis also showed that HDGF overexpression modulated the activity of phospho-AKT as well as NF-kB, and these results correlated with in vitro migration and invasion assays. We next assessed the therapeutic potential of HDGF inhibition with a HDGF monoclonal antibody and vitamin k 2 , showing reduced cell proliferation as well as inhibition of NF-kB expression in HDGF overexpressed RWPE cells treated with a HDGF monoclonal antibody and vitamin K 2 . Collectively, our results suggest that HDGF is a relevant protein in prostate oncogenesis and may serve as a potential therapeutic target in prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

A Mathematical Model of Intermittent Androgen Suppression for Prostate Cancer

NASA Astrophysics Data System (ADS)

Ideta, Aiko Miyamura; Tanaka, Gouhei; Takeuchi, Takumi; Aihara, Kazuyuki

2008-12-01

For several decades, androgen suppression has been the principal modality for treatment of advanced prostate cancer. Although the androgen deprivation is initially effective, most patients experience a relapse within several years due to the proliferation of so-called androgen-independent tumor cells. Bruchovsky et al. suggested in animal models that intermittent androgen suppression (IAS) can prolong the time to relapse when compared with continuous androgen suppression (CAS). Therefore, IAS has been expected to enhance clinical efficacy in conjunction with reduction in adverse effects and improvement in quality of life of patients during off-treatment periods. This paper presents a mathematical model that describes the growth of a prostate tumor under IAS therapy based on monitoring of the serum prostate-specific antigen (PSA). By treating the cancer tumor as a mixed assembly of androgen-dependent and androgen-independent cells, we investigate the difference between CAS and IAS with respect to factors affecting an androgen-independent relapse. Numerical and bifurcation analyses show how the tumor growth and the relapse time are influenced by the net growth rate of the androgen-independent cells, a protocol of the IAS therapy, and the mutation rate from androgen-dependent cells to androgen-independent ones.

Different profiles of neuroendocrine cell differentiation evolve in the PC-310 human prostate cancer model during long-term androgen deprivation.

PubMed

Jongsma, Johan; Oomen, Monique H; Noordzij, Marinus A; Van Weerden, Wytske M; Martens, Gerard J M; van der Kwast, Theodorus H; Schröder, Fritz H; van Steenbrugge, Gert J

2002-03-01

Neuroendocrine (NE) cells are androgen-independent cells and secrete growth-modulating peptide hormones via a regulated secretory pathway (RSP). We studied NE differentiation after long-term androgen withdrawal in the androgen-dependent human prostate cancer xenograft PC-310. Tumor-bearing nude mice were killed at 0, 2, 5, 7, 14, 21, 47, 84, and 154 days after castration. The half-life of the PC-310 tumor was 10 days, with a stable residual tumor volume of 30--40% after 21 days and longer periods of androgen deprivation. Proliferative activity and prostate-specific antigen serum levels decreased to zero after castration, whereas cell-cycle arrest was manifested by increased p27(kip1) expression. A temporary downregulation of androgen receptor (AR) expression was noted after androgen deprivation. The expression of chromogranin A, secretogranin III, and secretogranin V (7B2) increased 5 days after castration and later. Subsequently, pro-hormone convertase 1 and peptidyl alpha--amidating monooxygenase as well as vascular endothelial growth factor were expressed from 7 days after castration on. Finally, such growth factors as gastrin-releasing peptide and serotonin were expressed in a small part of the NE cells 21 days after castration, but strong expression was induced late during androgen deprivation, that is, 84 and 154 days after castration, respectively. Androgen deprivation of the NE-differentiated PC-310 model induced the formation of NE-differentiated AR(minus sign) and non-NE AR(+) tumor residues. The NE-differentiated cells actively produced growth factors via an RSP that may lead to hormone-refractory disease. The dormant non-NE AR(+) tumor cells were shown to remain androgen sensitive even after long-term androgen deprivation. In the PC-310 xenograft, time-dependent NE differentiation and subsequent maturation were induced after androgen depletion. The androgen-dependent PC-310 xenograft model constitutes an excellent model for studying the role of NE cells in the progression of clinical prostate cancer. Copyright 2002 Wiley-Liss, Inc.

Bim directly antagonizes Bcl-xl in doxorubicin-induced prostate cancer cell apoptosis independently of p53.

PubMed

Yang, Min-Chi; Lin, Ru-Wei; Huang, Shih-Bo; Huang, Shin-Yuan; Chen, Wen-Jie; Wang, Shiaw; Hong, Yi-Ren; Wang, Chihuei

2016-01-01

Doxorubicin and other anthracycline compounds exert their anti-cancer effects by causing DNA damage and initiating cell cycle arrest in cancer cells, followed by apoptosis. DNA damage generally activates a p53-mediated pathway to initiate apoptosis by increasing the level of the BH3-only protein, Puma. However, p53-mediated apoptosis in response to DNA damage has not yet been validated in prostate cancers. In the current study, we used LNCaP and PC3 prostate cancer cells, representing wild type p53 and a p53-null model, to determine if DNA damage activates p53-mediated apoptosis in prostate cancers. Our results revealed that PC3 cells were 4 to 8-fold less sensitive than LNCaP cells to doxorubicin-inuced apoptosis. We proved that the differential response of LNCaP and PC3 to doxorubicin was p53-independent by introducing wild-type or dominant negative p53 into PC3 or LNCaP cells, respectively. By comparing several apoptosis-related proteins in both cell lines, we found that Bcl-xl proteins were much more abundant in PC3 cells than in LNCaP cells. We further demonstrated that Bcl-xl protects LNCaP and PC3 cells from doxorubicin-induced apoptosis by using ABT-263, an inhibitor of Bcl-xl, as a single agent or in combination with doxorubicin to treat LNCaP or PC3 cells. Bcl-xl rather than p53, likely contributes to the differential response of LNCaP and PC3 to doxorubicin in apoptosis. Finally, co-immunoprecipitation and siRNA analysis revealed that a BH3-only protein, Bim, is involved in doxorubicin-induced apoptosis by directly counteracting Bcl-xl.

The natural compound Guttiferone F sensitizes prostate cancer to starvation induced apoptosis via calcium and JNK elevation.

PubMed

Li, Xin; Lao, Yuanzhi; Zhang, Hong; Wang, Xiaoyu; Tan, Hongsheng; Lin, Zhixiu; Xu, Hongxi

2015-04-11

In a cytotoxicity screen in serum-free medium, Guttiferone F showed strong growth inhibitory effect against prostate cancer cells. Prostate cancer cells LNCaP and PC3 were treated with Guttiferone F in serum depleted medium. Sub-G1 phase distributions were estimated with flow cytometry. Mitochondrial disruption was observed under confocal microscope using Mitotracker Red staining. Gene and protein expression changes were detected by real-time PCR and Western blotting. Ca(2+) elevation was examined by Fluo-4 staining under fluorescence microscope. PC3 xenografts in mice were examined by immunohistochemical analysis. Guttiferone F had strong growth inhibitory effect against prostate cancer cell lines under serum starvation. It induced a significant increase in sub-G1 fraction and DNA fragmentation. In serum-free medium, Guttiferone F triggered mitochondria dependent apoptosis by regulating Bcl-2 family proteins. In addition, Guttiferone F attenuated the androgen receptor expression and phosphorylation of ERK1/2, while activating the phosphorylation of JNK and Ca(2+) flux. Combination of caloric restriction with Guttiferone F in vivo could increase the antitumor effect without causing toxicity. Guttiferone F induced prostate cancer cell apoptosis under serum starvation via Ca(2+) elevation and JNK activation. Combined with caloric restriction, Guttiferone F exerted significant growth inhibition of PC3 cells xenograft in vivo. Guttiferone F is therefore a potential anti-cancer compound.

Longitudinal tracking of subpopulation dynamics and molecular changes during LNCaP cell castration and identification of inhibitors that could target the PSA-/lo castration-resistant cells.

PubMed

Rycaj, Kiera; Cho, Eun Jeong; Liu, Xin; Chao, Hsueh-Ping; Liu, Bigang; Li, Qiuhui; Devkota, Ashwini K; Zhang, Dingxiao; Chen, Xin; Moore, John; Dalby, Kevin N; Tang, Dean G

2016-03-22

We have recently demonstrated that the undifferentiated PSA-/lo prostate cancer (PCa) cell population harbors self-renewing long-term tumor-propagating cells that are refractory to castration, thus representing a therapeutic target. Our goals here are, by using the same lineage-tracing reporter system, to track the dynamic changes of PSA-/lo and PSA+ cells upon castration in vitro, investigate the molecular changes accompanying persistent castration, and develop large numbers of PSA-/lo PCa cells for drug screening. To these ends, we treated LNCaP cells infected with the PSAP-GFP reporter with three regimens of castration, i.e., CDSS, CDSS plus bicalutamide, and MDV3100 continuously for up to ~21 months. We observed that in the first ~7 months, castration led to time-dependent increases in PSA-/lo cells, loss of AR and PSA expression, increased expression of cancer stem cell markers, and many other molecular changes. Meanwhile, castrated LNCaP cells became resistant to high concentrations of MDV3100, chemotherapeutic drugs, and other agents. However, targeted and medium-throughput library screening identified several kinase (e.g., IGF-1R, AKT, PI3K/mTOR, Syk, GSK3) inhibitors as well as the BCL2 inhibitor that could effectively sensitize the LNCaP-CRPC cells to killing. Of interest, LNCaP cells castrated for >7 months showed evidence of cyclic changes in AR and the mTOR/AKT signaling pathways potentially involving epigenetic mechanisms. These observations indicate that castration elicits numerous molecular changes and leads to enrichment of PSA-/lo PCa cells. The ability to generate large numbers of PSA-/lo PCa cells should allow future high-throughput screening to identify novel therapeutics that specifically target this population.

Longitudinal tracking of subpopulation dynamics and molecular changes during LNCaP cell castration and identification of inhibitors that could target the PSA−/lo castration-resistant cells

PubMed Central

Rycaj, Kiera; Cho, Eun Jeong; Liu, Xin; Chao, Hsueh-Ping; Liu, Bigang; Li, Qiuhui; Devkota, Ashwini K.; Zhang, Dingxiao; Chen, Xin; Moore, John; Dalby, Kevin N.; Tang, Dean G.

2016-01-01

We have recently demonstrated that the undifferentiated PSA−/lo prostate cancer (PCa) cell population harbors self-renewing long-term tumor-propagating cells that are refractory to castration, thus representing a therapeutic target. Our goals here are, by using the same lineage-tracing reporter system, to track the dynamic changes of PSA−/lo and PSA+ cells upon castration in vitro, investigate the molecular changes accompanying persistent castration, and develop large numbers of PSA−/lo PCa cells for drug screening. To these ends, we treated LNCaP cells infected with the PSAP-GFP reporter with three regimens of castration, i.e., CDSS, CDSS plus bicalutamide, and MDV3100 continuously for up to ~21 months. We observed that in the first ~7 months, castration led to time-dependent increases in PSA−/lo cells, loss of AR and PSA expression, increased expression of cancer stem cell markers, and many other molecular changes. Meanwhile, castrated LNCaP cells became resistant to high concentrations of MDV3100, chemotherapeutic drugs, and other agents. However, targeted and medium-throughput library screening identified several kinase (e.g., IGF-1R, AKT, PI3K/mTOR, Syk, GSK3) inhibitors as well as the BCL2 inhibitor that could effectively sensitize the LNCaP-CRPC cells to killing. Of interest, LNCaP cells castrated for >7 months showed evidence of cyclic changes in AR and the mTOR/AKT signaling pathways potentially involving epigenetic mechanisms. These observations indicate that castration elicits numerous molecular changes and leads to enrichment of PSA−/lo PCa cells. The ability to generate large numbers of PSA−/lo PCa cells should allow future high-throughput screening to identify novel therapeutics that specifically target this population. PMID:26871947

A methylene chloride fraction of Saururus chinensis induces apoptosis through the activation of caspase-3 in prostate and breast cancer cells.

PubMed

Kim, Han-Young; Choi, Tae Won; Kim, Hyun Jung; Kim, Sung-Moo; Park, Kyung-Ran; Jang, Hyeung-Jin; Lee, Eun Ha; Kim, Chul Young; Jung, Sang Hoon; Shim, Bum Sang; Ahn, Kwang Seok

2011-05-15

The aerial parts of Saururus chinensis (SC) have been used for the treatment of edema, fever, jaundice, and inflammatory diseases in Korean folk medicine for centuries. However, the mechanism by which SC exerts these anti-tumorigenic activities in human prostate and breast cancer cells has not yet been fully understood. In this study, we report on the methylene chloride fraction from SC exerting cytotoxicity against prostate and breast cancer cells in a dose-dependent manner. Specifically, SC exerted the most potent cytotoxicity in LNCaP and MCF-7 cells. SC was shown to down-regulate various angiogenetic (VEGF), proliferative (Cyclin D₁, anti-apoptotic (Bcl-2) gene products in these cells. SC also increased the number of annexin V-positive apoptotic bodies and the sub-G1 DNA contents of the cell cycle undergoing apoptosis through caspase-3 activation in both LNCaP and MCF-7 cells. We further confirmed that caspase-3 plays an important role in SC-induced apoptosis in LNCaP and MCF-7 cells through the use of the caspase-3 inhibitor. Moreover, we observed that SC potentiated paclitaxel-induced apoptosis in MCF-7 cells and sauchinone is a major active constituent of SC, which could induce apoptosis in the cells. Taken together, our data provide the evidence that SC induces apoptosis depending on caspase-3 activation and overcomes the natural biological resistance to chemotherapy found in human prostate and breast cancer cells. Copyright © 2010 Elsevier GmbH. All rights reserved.

Pao Pereira Extract Suppresses Castration-Resistant Prostate Cancer Cell Growth, Survival, and Invasion Through Inhibition of NFκB Signaling.

PubMed

Chang, Cunjie; Zhao, Wei; Xie, Bingxian; Deng, Yongming; Han, Tao; Cui, Yangyan; Dai, Yundong; Zhang, Zhen; Gao, Jimin; Guo, Hongqian; Yan, Jun

2014-05-01

Pao extract, derived from bark of Amazonian tree Pao Pereira, is commonly used in South American medicine. A recent study showed that Pao extract repressed androgen-dependent LNCaP prostate cancer cell growth. We hypothesize that Pao extract asserts its anticancer effects on metastatic castration-resistant prostate cancer (CRPC) cells. Pao extract suppressed CRPC PC3 cell growth in a dose- and time-dependent manner, through induction of apoptosis and cell cycle arrest. Pao extract treatment induced cell cycle inhibitors, p21 and p27, and repressed PCNA, Cyclin A and Cyclin D1. Furthermore, Pao extract also induced the upregulation of pro-apoptotic Bax, reduction of anti-apoptotic Bcl-2, Bcl-xL, and XIAP expression, which were associated with the cleavage of PARP protein. Moreover, Pao extract treatment blocked PC3 cell migration and invasion. Mechanistically, Pao extract suppressed phosphorylation levels of AKT and NFκB/p65, NFκB DNA binding activity, and luciferase reporter activity. Pao inhibited TNFα-induced relocation of NFκB/p65 to the nucleus, NFκB/p65 transcription activity, and MMP9 activity as shown by zymography. Consistently, NFκB/p65 downstream targets involved in proliferation (Cyclin D1), survival (Bcl-2, Bcl-xL, and XIAP), and metastasis (VEGFa, MMP9, and GROα/CXCL1) were also downregulated by Pao extract. Finally, forced expression of NFκB/p65 reversed the growth inhibitory effect of Pao extract. Overall, Pao extract induced cell growth arrest, apoptosis, partially through inhibiting NFκB activation in prostate cancer cells. These data suggest that Pao extract may be beneficial for protection against CRPC. © The Author(s) 2013.

Regulation of expression of Na+,K+-ATPase in androgen-dependent and androgen-independent prostate cancer

PubMed Central

Blok, L J; Chang, G T G; Steenbeek-Slotboom, M; Weerden, W M van; Swarts, H G P; Pont, J J H H M De; Steenbrugge, G J van; Brinkmann, A O

1999-01-01

The β1-subunit of Na+,K+-ATPase was isolated and identified as an androgen down-regulated gene. Expression was observed at high levels in androgen-independent as compared to androgen-dependent (responsive) human prostate cancer cell lines and xenografts when grown in the presence of androgens. Down-regulation of the β1-subunit was initiated at concentrations between 0.01 nM and 0.03 nM of the synthetic androgen R1881 after relatively long incubation times (> 24 h). Using polyclonal antibodies, the concentration of β1-subunit protein, but not of the α1-subunit protein, was markedly reduced in androgen-dependent human prostate cancer cells (LNCaP-FGC) cultured in the presence of androgens. In line with these observations it was found that the protein expression of total Na+,K+-ATPase in the membrane (measured by 3H-ouabain binding) was also markedly decreased. The main function of Na+,K+-ATPase is to maintain sodium and potassium homeostasis in animal cells. The resulting electrochemical gradient is facilitative for transport of several compounds over the cell membrane (for example cisplatin, a chemotherapeutic agent experimentally used in the treatment of hormone-refractory prostate cancer). Here we observed that a ouabain-induced decrease of Na+,K+-ATPase activity in LNCaP-FGC cells results in reduced sensitivity of these cells to cisplatin-treatment. Surprisingly, androgen-induced decrease of Na+,K+-ATPase expression, did not result in significant protection against the chemotherapeutic agent. © 1999 Cancer Research Campaign PMID:10487609

Novel Therapeutic Targets to Inhibit Tumor Microenvironment Induced Castration-Resistant Prostate Cancer

DTIC Science & Technology

2017-12-01

LNCaP 13 cells with high concentration of Dox led to cell death). We have also tried to use the CRISPR /Cas9 gene editing technology to generate...tried to use the CRISPR /Cas9 gene editing technology to generate MAPK4 knockout LNCaP cells; however, LNCaP cells are in general hard to be cultured at

Antioxidant and antiproliferative potentials of methanol extract of Xylopia aethiopica (Dunal) A. Rich in PC-3 and LNCaP cells.

PubMed

Adaramoye, Oluwatosin Adekunle; Erguen, Bettina; Nitzsche, Bianca; Höpfner, Michael; Jung, Klaus; Rabien, Anja

2017-07-26

Our previous studies showed that fruit methanol extract from Xylopia aethiopica (MEXA) exhibited antiproliferative activity in human cervical cancer cells via the induction of apoptosis. The present study was designed to assess the antiproliferative, antiangiogenic and antioxidant effects of MEXA on prostate cancer (PCa) cells (PC-3 and LNCaP). PC-3 and LNCaP cells were cultured and treated with MEXA (10, 50 and 100 μg/mL). The sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate (XTT) and lactate dehydrogenase (LDH) assays were used to evaluate cell viability and cytotoxicity, respectively. DNA fragmentation was determined by cell death detection ELISA plus, and angiogenesis was assessed by chicken chorioallantoic membrane (CAM) assay. The antioxidant activities of MEXA were determined by DPPH and hydroxyl (OH) radicals' scavenging methods as well as through the inhibition of lipid peroxidation (LPO) in rats' liver homogenate. MEXA at 100, 250 and 500 μg/mL scavenged DPPH by 48%, 62%, 70% and OH radical by 39%, 58%, 67%, respectively. MEXA significantly (p<0.05) inhibited LPO in a concentration-dependent manner. In addition, MEXA had antiproliferative effects on PC-3 and LNCaP with IC50 of 62.1 and 73.6 μg/mL, respectively, at 96 h. The LDH assay showed that MEXA had low toxicity in vitro at its IC50 values. The extent of DNA fragmentation by MEXA showed higher values in PC-3 and LNCaP, suggesting the possible induction of apoptosis. In contrast, MEXA did not affect the network of vessels in CAM, thus lacking anti-angiogenic property. These findings suggest that MEXA induces antiproliferative activity in PCa cells through a mechanism that involves apoptosis. Therefore, MEXA may be a potential therapeutic agent for PCa.

In vitro effects of Apixaban on 5 different cancer cell lines

PubMed Central

Guasti, Luigina; Moretto, Paola; Vigetti, Davide; Ageno, Walter; Dentali, Francesco; Maresca, Andrea M.; Campiotti, Leonardo; Grandi, Anna M.; Passi, Alberto

2017-01-01

Background Cancer is associated with hypercoagulability. However, several data suggest that anticoagulant drugs may have an effect on tumor development and progression mediated by both coagulation dependent processes and non-coagulation dependent processes. Therefore, we investigated the in vitro effects of Apixaban on cell proliferation, mortality, cell migration, gene expression and matrix metalloproteinase in 5 different cancer cell lines. Methods The following cancer cell lines, and 2 normal fibroblast cultures (lung and dermal fibroblasts), were studied: OVCAR3 (ovarian cancer), MDA MB 231 (breast cancer), CaCO-2 (colon cancer), LNCaP (prostate cancer) and U937 (histiocytic lymphoma). Proliferation and cell mortality were assessed in control cells and Apixaban treated cultures (dose from 0.1 to 5 μg/ml, 0 to 96-h). Necrosis/Apoptosis (fluorescence microscopy), cell migration (24-h after scratch test), matrix metalloproteinase (MMP) activity and mRNA expression (RT PCR) of p16, p21, p53 and HAS were also assessed. Results High-dose (5 μg/ml) Apixaban incubation was associated with a significantly reduced proliferation in 3 cancer cell lines (OVCAR3, CaCO-2 and LNCaP) and with increased cancer cell mortality in all, except LNCaP, cancer lines. Apoptosis seems to account for the increased mortality. The migration capacity seems to be impaired after high-dose Apixaban incubation in OVCAR3 and CaCO-2 cells. Data on mRNA expression suggest a consistent increase in tumor suppression gene p16 in all cell lines. Conclusions Our data suggest that high-dose Apixaban may be able to interfere with cancer cell in vitro, reducing proliferation and increasing cancer cell mortality through apoptosis in several cancer cell lines. PMID:29023465

Suppression of LIM and SH3 Domain Protein 1 (LASP1) Negatively Regulated by Androgen Receptor Delays Castration Resistant Prostate Cancer Progression.

PubMed

Dejima, Takashi; Imada, Kenjiro; Takeuchi, Ario; Shiota, Masaki; Leong, Jeffrey; Tombe, Tabitha; Tam, Kevin; Fazli, Ladan; Naito, Seiji; Gleave, Martin E; Ong, Christopher J

2017-02-01

LIM and SH3 domain protein 1 (LASP1) has been implicated in several human malignancies and has been shown to predict PSA recurrence in prostate cancer. However, the anti-tumor effect of LASP1 knockdown and the association between LASP1 and the androgen receptor (AR) remains unclear. The aim of this study is to clarify the significance of LASP1 as a target for prostate cancer, and to test the effect of silencing LASP1 in vivo using antisense oligonucleotides (ASO). A tissue microarray (TMA) was performed to characterize the differences in LASP1 expression in prostate cancer treated after hormone deprivation therapy. Flow cytometry was used to analyze cell cycle. We designed LASP1 ASO for knockdown of LASP1 in vivo studies. The expression of LASP1 in TMA was increased after androgen ablation and persisted in castration resistant prostate cancer (CRPC). Also in TMA, compared with LNCaP cell, LASP1 expression is elevated in CRPC cell lines (C4-2 and VehA cells). Interestingly, suppression of AR elevated LASP1 expression conversely, AR activation decreased LASP1 expression. Silencing of LASP1 reduced cell growth through G1 arrest which was accompanied by a decrease of cyclin D1. Forced overexpression of LASP1 promoted cell cycle and induced cell growth which was accompanied by an increase of cyclin D1. Systemic administration of LASP1 ASO with athymic mice significantly inhibited tumor growth in CRPC xenografts. These results indicate that LASP1 is negatively regulated by AR at the transcriptional level and promotes tumor growth through induction of cell cycle, ultimately suggesting that LASP1 may be a potential target in prostate cancer treatment. Prostate 77:309-320, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Synergistic Effects of NDRG2 Overexpression and Radiotherapy on Cell Death of Human Prostate LNCaP Cells.

PubMed

Alizadeh Zarei, M; Takhshid, M A; Behzad Behbahani, A; Hosseini, S Y; Okhovat, M A; Rafiee Dehbidi, Gh R; Mosleh Shirazi, M A

2017-09-01

Radiation therapy is among the most conventional cancer therapeutic modalities with effective local tumor control. However, due to the development of radio-resistance, tumor recurrence and metastasis often occur following radiation therapy. In recent years, combination of radiotherapy and gene therapy has been suggested to overcome this problem. The aim of the current study was to explore the potential synergistic effects of N-Myc Downstream-Regulated Gene 2 (NDRG2) overexpression, a newly identified candidate tumor suppressor gene, with radiotherapy against proliferation of prostate LNCaP cell line. In this study, LNCaP cells were exposed to X-ray radiation in the presence or absence of NDRG2 overexpression using plasmid PSES- pAdenoVator-PSA-NDRG2-IRES-GFP. The effects of NDRG2 overexpression, X-ray radiation or combination of both on the cell proliferation and apoptosis of LNCaP cells were then analyzed using MTT assay and flow cytometery, respectively. Results of MTT assay showed that NDRG2 overexpression and X-ray radiation had a synergistic effect against proliferation of LNCaP cells. Moreover, NDRG2 overexpression increased apoptotic effect of X-ray radiation in LNCaP cells synergistically. Our findings suggested that NDRG2 overexpression in combination with radiotherapy may be an effective therapeutic option against prostate cancer.

Up-Regulation of Follistatin-Like 1 By the Androgen Receptor and Melanoma Antigen-A11 in Prostate Cancer.

PubMed

Su, Shifeng; Parris, Amanda B; Grossman, Gail; Mohler, James L; Wang, Zengjun; Wilson, Elizabeth M

2017-04-01

High affinity androgen binding to the androgen receptor (AR) activates genes required for male sex differentiation and promotes the development and progression of prostate cancer. Human AR transcriptional activity involves interactions with coregulatory proteins that include primate-specific melanoma antigen-A11 (MAGE-A11), a coactivator that increases AR transcriptional activity during prostate cancer progression to castration-resistant/recurrent prostate cancer (CRPC). Microarray analysis and quantitative RT-PCR were performed to identify androgen-regulated MAGE-A11-dependent genes in LAPC-4 prostate cancer cells after lentivirus shRNA knockdown of MAGE-A11. Chromatin immunoprecipitation was used to assess androgen-dependent AR recruitment, and immunocytochemistry to localize an androgen-dependent protein in prostate cancer cells and tissue and in the CWR22 human prostate cancer xenograft. Microarray analysis of androgen-treated LAPC-4 prostate cancer cells indicated follistatin-like 1 (FSTL1) is up-regulated by MAGE-A11. Androgen-dependent up-regulation of FSTL1 was inhibited in LAPC-4 cells by lentivirus shRNA knockdown of AR or MAGE-A11. Chromatin immunoprecipitation demonstrated AR recruitment to intron 10 of the FSTL1 gene that contains a classical consensus androgen response element. Increased levels of FSTL1 protein in LAPC-4 cells correlated with higher levels of MAGE-A11 relative to other prostate cancer cells. FSTL1 mRNA levels increased in CRPC and castration-recurrent CWR22 xenografts in association with predominantly nuclear FSTL1. Increased nuclear localization of FSTL1 in prostate cancer was suggested by predominantly cytoplasmic FSTL1 in benign prostate epithelial cells and predominantly nuclear FSTL1 in epithelial cells in CRPC tissue and the castration-recurrent CWR22 xenograft. AR expression studies showed nuclear colocalization of AR and endogenous FSTL1 in response to androgen. AR and MAGE-A11 cooperate in the up-regulation of FSTL1 to promote growth and progression of CRPC. Prostate 77:505-516, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cytotoxic effects of treosulfan on prostate cancer cell lines.

PubMed

Feyerabend, Susan; Feil, Gerhard; Krug, Jutta; Kassen, Annette; Stenzl, Arnulf

2007-01-01

Despite various therapeutical options in metastatic prostate cancer, the lack of a curative approach motivates further investigations. Treosulfan is an alkylating agent that has proven its indication in the treatment of e.g. ovarian carcinoma. This study focused on the objective of evaluating the effect of in vitro intoxication of human prostate carcinoma cell lines with treosulfan. Human prostate cancer cell lines LNCaP, DU145 and PC3 were treated with treosulfan concentrations from 0.5-500 microM for up to six days. Analysis of cell viability was performed using colorimetric WST-1 assay. Control data were obtained from identical cell lines cultivated without treosulfan. Incubation with treosulfan inhibited cell viability and led to cell death in all cell lines in a dose- and time-dependent manner. After one day, viability of LNCaP, DU145 and PC3 cells was constantly reduced with a dose rate of at least 10 microM (p < 0.001), 10 microM (p < 0.0001) and 100 microM (p < 0.0001) treosulfan, respectively. Minimum dose rates leading to death of nearly all LNCaP, DU145 and PC3 cells were 250 microM, 100 microM and 200 microM treosulfan, respectively. The results demonstrate a sensitivity of prostate carcinoma cells to the cytotoxic activity of treosulfan. Therefore, treosulfan might be a promising compound for novel treatment protocols for prostate cancer.

An AKT activity threshold regulates androgen-dependent and androgen-independent PSA expression in prostate cancer cell lines.

PubMed

Paliouras, Miltiadis; Diamandis, Eleftherios P

2008-06-01

The androgen receptor (AR) plays an important role in early prostate cancer by activating transcription of a number of genes participating in cell proliferation and growth and cancer progression. However, as the cancer progresses, prostate cancer cells transform from an androgen-dependent to an androgen-independent state. Androgen-independent prostate cancer can manifest itself in several forms, including a percentage of cancers that show reduced levels of prostate-specific antigen (PSA) and can progress without the need for the ligand or active receptor. Therefore, our goal was to examine the role of intracellular signaling pathways in an androgen-independent prostate cancer in vitro model. Using the cell line PC3(AR)(2), we stimulated cells with 5-alpha-dihydrotestosterone (DHT) and epidermal growth factor (EGF) and then analyzed PSA expression. We observed lower PSA expression when cells were jointly stimulated with DHT and EGF, and this was associated with an increase in AKT activity. We examined the role of AKT in AR activity and PSA expression by creating stable PC3(AR)(2) cell lines transfected with a PI3K-Ras-effector loop mutant. These cell lines showed lower DHT-stimulated PSA expression that correlated to changes in the phosphorylated state of AR. Therefore, we propose an in vitro androgen-independent model in which a PI3K/AKT activity threshold and subsequent AR transactivation regulate PSA expression.

Addressing of LnCaP Cell Using Magnetic Particles Assisted Impedimetric Microelectrode.

PubMed

Nguyen, Dung Thi Xuan; Tran, Trong Binh; Nguyen, Phuong-Diem; Min, Junhong

2016-03-01

In this study, we provide a facile, effective technique for a simple isolation and enrichment of low metastatic prostate tumor cell LNCaP using biocompatible, magnetic particles asissted impedimetric sensing system. Hydrophobic cell membrane anchors (BAM) were generated onto magnetic particles which diameters vary from 50 nm to 5 μm and were used to capture LNCaP cells from the suspension. Finally, magnetic particle-LNCaP complex were addressed onto the surface of the interdigitated microelectrode (IDM). Cell viability was monitored by our laboratory developed-technique Electrical Cell Substrate Impedance Sensing (ECIS). The results reavealed that 50 nm-magnetic particles showed best performance in terms of cell separation and cell viability. This technique provides a simple and efficient method for the direct addressing of LNCaP cell on the surface and enhances better understanding of cell behavior for cancer management in the near future.

CXCR6-CXCL16 axis promotes prostate cancer by mediating cytoskeleton rearrangement via Ezrin activation and αvβ3 integrin clustering.

PubMed

Singh, Rajesh; Kapur, Neeraj; Mir, Hina; Singh, Nalinaksha; Lillard, James W; Singh, Shailesh

2016-02-09

Cytoskeletal rearrangement is required for migration and invasion, which are the key steps of cancer metastasis. Ezrin and integrin co-ordinate these processes by regulating cellular adhesion and cytoskeletal polymerization-depolymerization. It is also well established that chemokine-chemokine receptor axis plays a crucial role in regulating cancer cell migration and invasion. In this study, we show involvement of CXC chemokine receptor 6 (CXCR6) and its only natural ligand CXCL16 in pathobiology of prostate cancer (PCa). CXCR6 is highly expressed in PCa tissues and cell lines (LNCaP and PC3), relative to normal tissue and cells. CXCR6 expression in PCa tissues correlated with higher Gleason score. Similarly, aggressive PCa cells (PC3) show high CXCR6 compared to less aggressive LNCaP. Besides, PC3 cells show higher MMPs expression compared to LNCaP cells following CXCL16 stimulation. Intriguingly, CXCR6-CXCL16 interaction in PCa cells promotes Ezrin activation, αvβ3 integrin clustering and capping at the leading edge in FAK/PI3K/PKC dependent manner, thereby modifying cellular adhesion as well as motility. Together these results demonstrate that CXCL16 stimulation changes cytoskeletal dynamics resulting in enhanced migration, invasion and adhesion to endothelial cells, ultimately enabling PCa cells to achieve their metastatic goal.

CXCR6-CXCL16 axis promotes prostate cancer by mediating cytoskeleton rearrangement via Ezrin activation and αvβ3 integrin clustering

PubMed Central

Singh, Rajesh; Kapur, Neeraj; Mir, Hina; Singh, Nalinaksha; Lillard, James W.; Singh, Shailesh

2016-01-01

Cytoskeletal rearrangement is required for migration and invasion, which are the key steps of cancer metastasis. Ezrin and integrin co-ordinate these processes by regulating cellular adhesion and cytoskeletal polymerization-depolymerization. It is also well established that chemokine-chemokine receptor axis plays a crucial role in regulating cancer cell migration and invasion. In this study, we show involvement of CXC chemokine receptor 6 (CXCR6) and its only natural ligand CXCL16 in pathobiology of prostate cancer (PCa). CXCR6 is highly expressed in PCa tissues and cell lines (LNCaP and PC3), relative to normal tissue and cells. CXCR6 expression in PCa tissues correlated with higher Gleason score. Similarly, aggressive PCa cells (PC3) show high CXCR6 compared to less aggressive LNCaP. Besides, PC3 cells show higher MMPs expression compared to LNCaP cells following CXCL16 stimulation. Intriguingly, CXCR6-CXCL16 interaction in PCa cells promotes Ezrin activation, αvβ3 integrin clustering and capping at the leading edge in FAK/PI3K/PKC dependent manner, thereby modifying cellular adhesion as well as motility. Together these results demonstrate that CXCL16 stimulation changes cytoskeletal dynamics resulting in enhanced migration, invasion and adhesion to endothelial cells, ultimately enabling PCa cells to achieve their metastatic goal. PMID:26799186

Screening of synthetic and natural product databases: Identification of novel androgens and antiandrogens.

PubMed

Bobach, Claudia; Tennstedt, Stephanie; Palberg, Kristin; Denkert, Annika; Brandt, Wolfgang; de Meijere, Armin; Seliger, Barbara; Wessjohann, Ludger A

2015-01-27

The androgen receptor is an important pharmaceutical target for a variety of diseases. This paper presents an in silico/in vitro screening procedure to identify new androgen receptor ligands. The two-step virtual screening procedure uses a three-dimensional pharmacophore model and a docking/scoring routine. About 39,000 filtered compounds were docked with PLANTS and scored by Chemplp. Subsequent to virtual screening, 94 compounds, including 28 steroidal and 66 nonsteroidal compounds, were tested by an androgen receptor fluorescence polarization ligand displacement assay. As a result, 30 compounds were identified that show a relative binding affinity of more than 50% in comparison to 100 nM dihydrotestosterone and were classified as androgen receptor binders. For 11 androgen receptor binders of interest IC50 and Ki values were determined. The compound with the highest affinity exhibits a Ki value of 10.8 nM. Subsequent testing of the 11 compounds in a PC-3 and LNCaP multi readout proliferation assay provides insights into the potential mode of action. Further steroid receptor ligand displacement assays and docking studies on estrogen receptors α and β, glucocorticoid receptor, and progesterone receptor gave information about the specificity of the 11 most active compounds. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

In vivo biomarker expression patterns are preserved in 3D cultures of Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Windus, Louisa C.E.; Kiss, Debra L.; Glover, Tristan

2012-11-15

Here we report that Prostate Cancer (PCa) cell-lines DU145, PC3, LNCaP and RWPE-1 grown in 3D matrices in contrast to conventional 2D monolayers, display distinct differences in cell morphology, proliferation and expression of important biomarker proteins associated with cancer progression. Consistent with in vivo growth rates, in 3D cultures, all PCa cell-lines were found to proliferate at significantly lower rates in comparison to their 2D counterparts. Moreover, when grown in a 3D matrix, metastatic PC3 cell-lines were found to mimic more precisely protein expression patterns of metastatic tumour formation as found in vivo. In comparison to the prostate epithelial cell-linemore » RWPE-1, metastatic PC3 cell-lines exhibited a down-regulation of E-cadherin and {alpha}6 integrin expression and an up-regulation of N-cadherin, Vimentin and {beta}1 integrin expression and re-expressed non-transcriptionally active AR. In comparison to the non-invasive LNCaP cell-lines, PC3 cells were found to have an up-regulation of chemokine receptor CXCR4, consistent with a metastatic phenotype. In 2D cultures, there was little distinction in protein expression between metastatic, non-invasive and epithelial cells. These results suggest that 3D cultures are more representative of in vivo morphology and may serve as a more biologically relevant model in the drug discovery pipeline. -- Highlights: Black-Right-Pointing-Pointer We developed and optimised 3D culturing techniques for Prostate Cancer cell-lines. Black-Right-Pointing-Pointer We investigated biomarker expression in 2D versus 3D culture techniques. Black-Right-Pointing-Pointer Metastatic PC3 cells re-expressed non-transcriptionally active androgen receptor. Black-Right-Pointing-Pointer Metastatic PCa cell lines retain in vivo-like antigenic profiles in 3D cultures.« less

Formononetin-induced apoptosis of human prostate cancer cells through ERK1/2 mitogen-activated protein kinase inactivation.

PubMed

Ye, Y; Hou, R; Chen, J; Mo, L; Zhang, J; Huang, Y; Mo, Z

2012-04-01

Formononetin is a main active component of red clover plants (Trifolium pratense L.), and is considered as a phytoestrogen. Our previous studies demonstrated that formononetin caused cell cycle arrest at the G0/G1 phase by inactivating insulin-like growth factor 1(IGF1)/IGF1R-phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in MCF-7 cells. In the present study, we investigated the molecular mechanisms involved in the effect of formononetin on prostate cancer cells. Our results suggested that higher concentrations of formononetin inhibited the proliferation of prostate cancer cells (LNCaP and PC-3), while the most striking effect was observed in LNCaP cells. We further found that formononetin inactivated extracellular signal-regulated kinase1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signaling pathway in a dose-dependent manner, which resulted in increased the expression levels of BCL2-associated X (Bax) mRNA and protein, and induced apoptosis in LNCaP cells. Thus, we concluded that the induced apoptosis effect of formononetin on human prostate cancer cells was related to ERK1/2 MAPK-Bax pathway. Considering that red clover plants were widely used clinically, our results provided the foundation for future development of different concentrations formononetin for treatment of prostate cancer. © Georg Thieme Verlag KG Stuttgart · New York.

Enhancement of Intermittent Androgen Ablation Therapy by Finasteride Administration in Animal Models

DTIC Science & Technology

2005-02-01

40 E 250° U0 200- 0 150- 50- 01 Treament group (tumor volume in cm3 at time of randomization) Figure 2: a) Mean percent change in LNCaP tumor volume...40- S30- . 20- 10 CAA F T T+F c 350- 300- OM P 250- 2! ." Q. 0 200- 0 150- ~.100 ** ’ 50 Treament group (tumor volume in cm 3 at time of randomization

In Silico Analysis Identifies a Novel Role for Androgens in the Regulation of Human Endometrial Apoptosis

PubMed Central

Marshall, Elaine; Lowrey, Jacqueline; MacPherson, Sheila; Maybin, Jacqueline A.; Collins, Frances; Critchley, Hilary O. D.

2011-01-01

Context: The endometrium is a multicellular, steroid-responsive tissue that undergoes dynamic remodeling every menstrual cycle in preparation for implantation and, in absence of pregnancy, menstruation. Androgen receptors are present in the endometrium. Objective: The objective of the study was to investigate the impact of androgens on human endometrial stromal cells (hESC). Design: Bioinformatics was used to identify an androgen-regulated gene set and processes associated with their function. Regulation of target genes and impact of androgens on cell function were validated using primary hESC. Setting: The study was conducted at the University Research Institute. Patients: Endometrium was collected from women with regular menses; tissues were used for recovery of cells, total mRNA, or protein and for immunohistochemistry. Results: A new endometrial androgen target gene set (n = 15) was identified. Bioinformatics revealed 12 of these genes interacted in one pathway and identified an association with control of cell survival. Dynamic androgen-dependent changes in expression of the gene set were detected in hESC with nine significantly down-regulated at 2 and/or 8 h. Treatment of hESC with dihydrotestosterone reduced staurosporine-induced apoptosis and cell migration/proliferation. Conclusions: Rigorous in silico analysis resulted in identification of a group of androgen-regulated genes expressed in human endometrium. Pathway analysis and functional assays suggest androgen-dependent changes in gene expression may have a significant impact on stromal cell proliferation, migration, and survival. These data provide the platform for further studies on the role of circulatory or local androgens in the regulation of endometrial function and identify androgens as candidates in the pathogenesis of common endometrial disorders including polycystic ovarian syndrome, cancer, and endometriosis. PMID:21865353

Multimodal actions of the phytochemical sulforaphane suppress both AR and AR-V7 in 22Rv1 cells: Advocating a potent pharmaceutical combination against castration-resistant prostate cancer.

PubMed

Khurana, Namrata; Kim, Hogyoung; Chandra, Partha K; Talwar, Sudha; Sharma, Pankaj; Abdel-Mageed, Asim B; Sikka, Suresh C; Mondal, Debasis

2017-11-01

Prostate cancer (PCa) cells expressing full-length androgen receptor (AR-FL) are susceptible to androgen deprivation therapy (ADT). However, outgrowth of castration-resistant prostate cancer (CRPC) can occur due to the expression of constitutively active (ligand-independent) AR splice variants, particularly AR-V7. We previously demonstrated that sulforaphane (SFN), an isothiocyanate phytochemical, can decrease AR-FL levels in the PCa cell lines, LNCaP and C4-2B. Here, we examined the efficacy of SFN in targeting both AR-FL and AR-V7 in the CRPC cell line, CWR22Rv1 (22Rv1). MTT cell viability, wound-heal assay, and colony forming unit (CFU) measurements revealed that 22Rv1 cells are resistant to the anti-androgen, enzalutamide (ENZ). However, co-exposure to SFN sensitized these cells to the potent anticancer effects of ENZ (P<0.05). Immunoblot analyses showed that SFN (5-20 µM) rapidly decreases both AR-FL and AR-V7 levels, and immunofluorescence microscopy (IFM) depicted decreased AR in both cytoplasm and nucleus with SFN treatment. SFN increased both ubiquitination and proteasomal activity in 22Rv1 cells. Studies using a protein synthesis inhibitor (cycloheximide) or a proteasomal inhibitor (MG132) indicated that SFN increases both ubiquitin-mediated aggregation and subsequent proteasomal-degradation of AR proteins. Previous studies reported that SFN inhibits the chaperone activity of heat-shock protein 90 (Hsp90) and induces the nuclear factor erythroid-2-like 2 (Nrf2) transcription factor. Therefore, we investigated whether the Hsp90 inhibitor, ganetespib (G) or the Nrf2 activator, bardoxolone methyl (BM) can similarly suppress AR levels in 22Rv1 cells. Low doses of G and BM, alone or in combination, decreased both AR-FL and AR-V7 levels, and combined exposure to G+BM sensitized 22Rv1 cells to ENZ. Therefore, adjunct treatment with the phytochemical SFN or a safe pharmaceutical combination of G+BM may be effective against CRPC cells, especially those expressing AR-V7.

Multimodal actions of the phytochemical sulforaphane suppress both AR and AR-V7 in 22Rv1 cells: Advocating a potent pharmaceutical combination against castration-resistant prostate cancer

PubMed Central

Khurana, Namrata; Kim, Hogyoung; Chandra, Partha K.; Talwar, Sudha; Sharma, Pankaj; Abdel-Mageed, Asim B.; Sikka, Suresh C.; Mondal, Debasis

2017-01-01

Prostate cancer (PCa) cells expressing full-length androgen receptor (AR-FL) are susceptible to androgen deprivation therapy (ADT). However, outgrowth of castration-resistant prostate cancer (CRPC) can occur due to the expression of constitutively active (ligand-independent) AR splice variants, particularly AR-V7. We previously demonstrated that sulforaphane (SFN), an isothiocyanate phytochemical, can decrease AR-FL levels in the PCa cell lines, LNCaP and C4-2B. Here, we examined the efficacy of SFN in targeting both AR-FL and AR-V7 in the CRPC cell line, CWR22Rv1 (22Rv1). MTT cell viability, wound-heal assay, and colony forming unit (CFU) measurements revealed that 22Rv1 cells are resistant to the anti-androgen, enzalutamide (ENZ). However, co-exposure to SFN sensitized these cells to the potent anticancer effects of ENZ (P<0.05). Immunoblot analyses showed that SFN (5–20 µM) rapidly decreases both AR-FL and AR-V7 levels, and immunofluorescence microscopy (IFM) depicted decreased AR in both cytoplasm and nucleus with SFN treatment. SFN increased both ubiquitination and proteasomal activity in 22Rv1 cells. Studies using a protein synthesis inhibitor (cycloheximide) or a proteasomal inhibitor (MG132) indicated that SFN increases both ubiquitin-mediated aggregation and subsequent proteasomal-degradation of AR proteins. Previous studies reported that SFN inhibits the chaperone activity of heat-shock protein 90 (Hsp90) and induces the nuclear factor erythroid-2-like 2 (Nrf2) transcription factor. Therefore, we investigated whether the Hsp90 inhibitor, ganetespib (G) or the Nrf2 activator, bardoxolone methyl (BM) can similarly suppress AR levels in 22Rv1 cells. Low doses of G and BM, alone or in combination, decreased both AR-FL and AR-V7 levels, and combined exposure to G+BM sensitized 22Rv1 cells to ENZ. Therefore, adjunct treatment with the phytochemical SFN or a safe pharmaceutical combination of G+BM may be effective against CRPC cells, especially those expressing AR-V7. PMID:28901514

ING3 promotes prostate cancer growth by activating the androgen receptor.

PubMed

Nabbi, Arash; McClurg, Urszula L; Thalappilly, Subhash; Almami, Amal; Mobahat, Mahsa; Bismar, Tarek A; Binda, Olivier; Riabowol, Karl T

2017-05-16

The androgen receptor (AR) is a major driver of prostate cancer, and increased AR levels and co-activators of the receptor promote the development of prostate cancer. INhibitor of Growth (ING) proteins target lysine acetyltransferase or lysine deacetylase complexes to the histone H3K4Me3 mark of active transcription, to affect chromatin structure and gene expression. ING3 is a stoichiometric member of the TIP60 lysine acetyltransferase complex implicated in prostate cancer development. Biopsies of 265 patients with prostate cancer were stained for ING3, pan-cytokeratin, and DNA. LNCaP and C4-2 androgen-responsive cells were used for in vitro assays including immunoprecipitation, western blotting, Luciferase reporter assay and quantitative polymerase chain reaction. Cell viability and migration assays were performed in prostate cancer cell lines using scrambled siRNA or siRNA targeting ING3. We find that ING3 levels and AR activity positively correlate in prostate cancer. ING3 potentiates androgen effects, increasing expression of androgen-regulated genes and androgen response element-driven reporters to promote growth and anchorage-independent growth. Conversely, ING3 knockdown inhibits prostate cancer cell growth and invasion. ING3 activates the AR by serving as a scaffold to increase interaction between TIP60 and the AR in the cytoplasm, enhancing receptor acetylation and translocation to the nucleus. Activation is independent of ING3's ability to target the TIP60 complex to H3K4Me3, identifying a previously unknown chromatin-independent cytoplasmic activity for ING3. In agreement with in vitro observations, analysis of The Cancer Genome Atlas (TCGA) data (n = 498) and a prostate cancer tissue microarray (n = 256) show that ING3 levels are higher in aggressive prostate cancers, with high levels of ING3 predicting shorter patient survival in a low AR subgroup. Including ING3 levels with currently used indicators such as the Gleason score provides more accurate prognosis in primary prostate cancer. In contrast to the majority of previous reports suggesting tumor suppressive functions in other cancers, our observations identify a clear oncogenic role for ING3, which acts as a co-activator of AR in prostate cancer. Data from TCGA and our previous and current tissue microarrays suggest that ING3 levels correlate with AR levels and that in patients with low levels of the receptor, ING3 level could serve as a useful prognostic biomarker.

Additive naftopidil treatment synergizes docetaxel-induced apoptosis in human prostate cancer cells.

PubMed

Ishii, Kenichiro; Matsuoka, Izumi; Kajiwara, Shinya; Sasaki, Takeshi; Miki, Manabu; Kato, Manabu; Kanda, Hideki; Arima, Kiminobu; Shiraishi, Taizo; Sugimura, Yoshiki

2018-01-01

Docetaxel (DTX) is a standard chemotherapeutic drug for castration-resistant prostate cancer (CRPC), although adverse events are common. To overcome this problem, researchers have evaluated the efficacy of DTX treatment in combination with other drugs. Naftopidil is a tubulin-binding drug with fewer adverse events, implying the usefulness of this drug in clinical applications when combined with DTX. Here, we investigated the efficacy of additive naftopidil treatment in combination with DTX on prostate cancer (PCa) cells. The effects of combination treatment with DTX plus naftopidil were analyzed using two animal models of LNCaP cells plus PrSC xenografts (sub-renal capsule grafting) and PC-3 xenografts (intratibial injection). Combination treatment with DTX plus naftopidil significantly inhibited cell growth in LNCaP cells compared with DTX alone. Analysis of the cooperativity index (CI) showed that combination treatment exhibited additive effects on DTX-induced growth inhibition in LNCaP cells. In contrast, combination treatment showed more than an additive (synergistic) effect on DTX-induced apoptosis in LNCaP and PC-3 cells. In LNCaP cells plus PrSC xenografts, combination treatment showed synergistic effects on DTX-induced apoptosis. The synergistic effects of naftopidil on DTX-induced apoptosis were also observed in PC-3 xenografts. Our results demonstrated that additive naftopidil treatment in combination with DTX increased the efficacy of DTX for the treatment of LNCaP and PC-3 tumors in vivo. Thus, additive naftopidil treatment showed a synergistic effect on DTX-induced apoptosis in PCa cells in vitro and in vivo, suggesting that this treatment approach may yield improved clinical benefits compared with DTX alone.

Probing the prostate tumour microenvironment II: Impact of hypoxia on a cell model of prostate cancer progression

PubMed Central

Tonry, Claire; Armstrong, John; Pennington, Stephen

2017-01-01

Approximately one in six men are diagnosed with Prostate Cancer every year in the Western world. Although it can be well managed and non-life threatening in the early stages, over time many patients cease to respond to treatment and develop castrate resistant prostate cancer (CRPC). CRPC represents a clinically challenging and lethal form of prostate cancer. Progression of CRPC is, in part, driven by the ability of cancer cells to alter their metabolic profile during the course of tumourgenesis and metastasis so that they can survive in oxygen and nutrient-poor environments and even withstand treatment. This work was carried out as a continuation of a study aimed towards gaining greater mechanistic understanding of how conditions within the tumour microenvironment impact on both androgen sensitive (LNCaP) and androgen independent (LNCaP-abl and LNCaP-abl-Hof) prostate cancer cell lines. Here we have applied technically robust and reproducible label-free liquid chromatography mass spectrometry analysis for comprehensive proteomic profiling of prostate cancer cell lines under hypoxic conditions. This led to the identification of over 4,000 proteins – one of the largest protein datasets for prostate cancer cell lines established to date. The biological and clinical significance of proteins showing a significant change in expression as result of hypoxic conditions was established. Novel, intuitive workflows were subsequently implemented to enable robust, reproducible and high throughput verification of selected proteins of interest. Overall, these data suggest that this strategy supports identification of protein biomarkers of prostate cancer progression and potential therapeutic targets for CRPC. PMID:28410543

Probing the prostate tumour microenvironment I: impact of glucose deprivation on a cell model of prostate cancer progression

PubMed Central

Tonry, Claire; Armstrong, John; Pennington, Stephen R.

2017-01-01

In the developed world, prostate cancer is the most common cancer diagnosis in men. Although prostate cancer initially presents as a non life-threatening disease, 90% of patients will develop castration resistant prostate cancer (CRPC), which preludes distant metastasis and is largely accountable for prostate cancer associated deaths. This is because as yet, there are no viable molecular therapeutic targets for effective treatment of CRPC. It is now widely accepted that cancer cells can alter their metabolic profile during the course of tumourgenesis and metastasis such that they are able to survive in oxygen and nutrient-poor environments. This work was aimed towards gaining greater mechanistic understanding of how such stresses in the tumour microenvironment impact on both androgen sensitive (LNCaP) and androgen independent (LNCaP-abl and LNCaP-abl-Hof) prostate cancer cell lines. Here we have applied technically robust and reproducible label-free liquid chromatography mass spectrometry analysis for comprehensive proteomic profiling of prostate cancer cell lines under nutrient deficient (low glucose) conditions. This led to the identification of approximately 4,000 proteins - one of the largest protein datasets for prostate cancer cell lines established to date. The biological and clinical significance of proteins showing a significant change in expression as result of low glucose conditions was established. Novel, intuitive workflows were subsequently implemented to ensure the verification of selected proteins of interest in a robust, reproducible and high throughput manner. Overall, these data suggest that this strategy supports identification of protein biomarkers of prostate cancer progression and potential therapeutic targets for CRPC. PMID:28086232

Bypass Mechanisms of the Androgen Receptor Pathway in Therapy-Resistant Prostate Cancer Cell Models

PubMed Central

Marques, Rute B.; Dits, Natasja F.; Erkens-Schulze, Sigrun; van Weerden, Wytske M.; Jenster, Guido

2010-01-01

Background Prostate cancer is initially dependent on androgens for survival and growth, making hormonal therapy the cornerstone treatment for late-stage tumors. However, despite initial remission, the cancer will inevitably recur. The present study was designed to investigate how androgen-dependent prostate cancer cells eventually survive and resume growth under androgen-deprived and antiandrogen supplemented conditions. As model system, we used the androgen-responsive PC346C cell line and its therapy-resistant sublines: PC346DCC, PC346Flu1 and PC346Flu2. Methodology/Principal Findings Microarray technology was used to analyze differences in gene expression between the androgen-responsive and therapy-resistant PC346 cell lines. Microarray analysis revealed 487 transcripts differentially-expressed between the androgen-responsive and the therapy-resistant cell lines. Most of these genes were common to all three therapy-resistant sublines and only a minority (∼5%) was androgen-regulated. Pathway analysis revealed enrichment in functions involving cellular movement, cell growth and cell death, as well as association with cancer and reproductive system disease. PC346DCC expressed residual levels of androgen receptor (AR) and showed significant down-regulation of androgen-regulated genes (p-value = 10−7). Up-regulation of VAV3 and TWIST1 oncogenes and repression of the DKK3 tumor-suppressor was observed in PC346DCC, suggesting a potential AR bypass mechanism. Subsequent validation of these three genes in patient samples confirmed that expression was deregulated during prostate cancer progression. Conclusions/Significance Therapy-resistant growth may result from adaptations in the AR pathway, but androgen-independence may also be achieved by alternative survival mechanisms. Here we identified TWIST1, VAV3 and DKK3 as potential players in the bypassing of the AR pathway, making them good candidates as biomarkers and novel therapeutical targets. PMID:20976069

Overcoming Autophagy to Induce Apoptosis in Castration-Resistant Prostate Cancer

DTIC Science & Technology

2014-10-01

LNCaP C4-2B MDV-R, LNCaP GRP Pro cells and CWR22 xenograft were used . In LNCaP C4-2B MDV-R study, we validated that using autophagy modulators...growth (91% and 78% for combinational use of CMI and metf with enzalutamide, respectively) was observed. In the LNCaP GRP model, combinational...sequencing data and found the trend agreeable. In the past year, we focused on in vivo studies using LNCaP C4-2B enza-resistant, GRP-Pro orthotopic and

Polycaprolactone/maltodextrin nanocarrier for intracellular drug delivery: formulation, uptake mechanism, internalization kinetics, and subcellular localization.

PubMed

Korang-Yeboah, Maxwell; Gorantla, Yamini; Paulos, Simon A; Sharma, Pankaj; Chaudhary, Jaideep; Palaniappan, Ravi

2015-01-01

Prostate cancer (PCa) disease progression is associated with significant changes in intracellular and extracellular proteins, intracellular signaling mechanism, and cancer cell phenotype. These changes may have direct impact on the cellular interactions with nanocarriers; hence, there is the need for a much-detailed understanding, as nanocarrier cellular internalization and intracellular sorting mechanism correlate directly with bioavailability and clinical efficacy. In this study, we report the differences in the rate and mechanism of cellular internalization of a biocompatible polycaprolactone (PCL)/maltodextrin (MD) nanocarrier system for intracellular drug delivery in LNCaP, PC3, and DU145 PCa cell lines. PCL/MD nanocarriers were designed and characterized. PCL/MD nanocarriers significantly increased the intracellular concentration of coumarin-6 and fluorescein isothiocyanate-labeled bovine serum albumin, a model hydrophobic and large molecule, respectively. Fluorescence microscopy and flow cytometry analysis revealed rapid internalization of the nanocarrier. The extent of nanocarrier cellular internalization correlated directly with cell line aggressiveness. PCL/MD internalization was highest in PC3 followed by DU145 and LNCaP, respectively. Uptake in all PCa cell lines was metabolically dependent. Extraction of endogenous cholesterol by methyl-β-cyclodextrin reduced uptake by 75%±4.53% in PC3, 64%±6.01% in LNCaP, and 50%±4.50% in DU145, indicating the involvement of endogenous cholesterol in cellular internalization. Internalization of the nanocarrier in LNCaP was mediated mainly by macropinocytosis and clathrin-independent pathways, while internalization in PC3 and DU145 involved clathrin-mediated endocytosis, clathrin-independent pathways, and macropinocytosis. Fluorescence microscopy showed a very diffused and non-compartmentalized subcellular localization of the PCL/MD nanocarriers with possible intranuclear localization and minor colocalization in the lysosomes with time.

Amino-terminal enhancer of split gene AES encodes a tumor and metastasis suppressor of prostate cancer.

PubMed

Okada, Yoshiyuki; Sonoshita, Masahiro; Kakizaki, Fumihiko; Aoyama, Naoki; Itatani, Yoshiro; Uegaki, Masayuki; Sakamoto, Hiromasa; Kobayashi, Takashi; Inoue, Takahiro; Kamba, Tomomi; Suzuki, Akira; Ogawa, Osamu; Taketo, M Mark

2017-04-01

A major cause of cancer death is its metastasis to the vital organs. Few effective therapies are available for metastatic castration-resistant prostate cancer (PCa), and progressive metastatic lesions such as lymph nodes and bones cause mortality. We recently identified AES as a metastasis suppressor for colon cancer. Here, we have studied the roles of AES in PCa progression. We analyzed the relationship between AES expression and PCa stages of progression by immunohistochemistry of human needle biopsy samples. We then performed overexpression and knockdown of AES in human PCa cell lines LNCaP, DU145 and PC3, and determined the effects on proliferation, invasion and metastasis in culture and in a xenograft model. We also compared the PCa phenotypes of Aes/Pten compound knockout mice with those of Pten simple knockout mice. Expression levels of AES were inversely correlated with clinical stages of human PCa. Exogenous expression of AES suppressed the growth of LNCaP cells, whereas the AES knockdown promoted it. We also found that AES suppressed transcriptional activities of androgen receptor and Notch signaling. Notably, AES overexpression in AR-defective DU145 and PC3 cells reduced invasion and metastasis to lymph nodes and bones without affecting proliferation in culture. Consistently, prostate epithelium-specific inactivation of Aes in Pten flox/flox mice increased expression of Snail and MMP9, and accelerated growth, invasion and lymph node metastasis of the mouse prostate tumor. These results suggest that AES plays an important role in controlling tumor growth and metastasis of PCa by regulating both AR and Notch signaling pathways. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Celastrol, a triterpene extracted from the Chinese "Thunder of God Vine," is a potent proteasome inhibitor and suppresses human prostate cancer growth in nude mice.

PubMed

Yang, Huanjie; Chen, Di; Cui, Qiuzhi Cindy; Yuan, Xiao; Dou, Q Ping

2006-05-01

Interest in the use of traditional medicines for cancer prevention and treatment is increasing. In vitro, in vivo, and clinical studies suggest the potential use of proteasome inhibitors as novel anticancer drugs. Celastrol, an active compound extracted from the root bark of the Chinese medicine "Thunder of God Vine" (Tripterygium wilfordii Hook F.), was used for years as a natural remedy for inflammatory conditions. Although Celastrol has been shown to induce leukemia cell apoptosis, the molecular target involved has not been identified. Furthermore, whether Celastrol has antitumor activity in vivo has never been conclusively shown. Here, we report, for the first time, that Celastrol potently and preferentially inhibits the chymotrypsin-like activity of a purified 20S proteasome (IC(50) = 2.5 micromol/L) and human prostate cancer cellular 26S proteasome (at 1-5 micromol/L). Inhibition of the proteasome activity by Celastrol in PC-3 (androgen receptor- or AR-negative) or LNCaP (AR-positive) cells results in the accumulation of ubiquitinated proteins and three natural proteasome substrates (IkappaB-alpha, Bax, and p27), accompanied by suppression of AR protein expression (in LNCaP cells) and induction of apoptosis. Treatment of PC-3 tumor-bearing nude mice with Celastrol (1-3 mg/kg/d, i.p., 1-31 days) resulted in significant inhibition (65-93%) of the tumor growth. Multiple assays using the animal tumor tissue samples from both early and end time points showed in vivo inhibition of the proteasomal activity and induction of apoptosis after Celastrol treatment. Our results show that Celastrol is a natural proteasome inhibitor that has a great potential for cancer prevention and treatment.

Evaluation of theranostic nanocarriers for near-infrared imaging and photodynamic therapy on human prostate cancer cells.

PubMed

Leandro, Fernanda Z; Martins, Júlia; Fontes, Aparecida M; Tedesco, Antonio C

2017-06-01

This paper evaluates how effectively chloroaluminum phthalocyanine (ClAlPc) entrapped in colloidal nanocarriers, such as nanocapsule (NC) and nanoemulsion (NE), induces photodamage in human prostate cancer cells (LNCaP) during photodynamic therapy (PDT). The MTT cell viability assay showed that both ClAlPc-NC and ClAlPc-NE induced phototoxicity and efficiently killed LNCaP cells at low ClAlPc-NC and ClAlPc-NE concentrations (0.3μgmL -1 ) as well as under low light doses of 4Jcm -2 and 7Jcm -2 , respectively, upon PDT with a 670-nm diode laser line. Confocal imaging studies indicated that ClAlPc-NC and ClAlPc-NE were preferentially localized in the perinuclear region of LNCaP cells both in the dark and upon irradiation with laser light. After PDT treatment, ClAlPc-NC-treated LNCaP cells exhibited a higher green fluorescence signal, possibly due to the larger shrinkage of the actin cytoskeleton, compared to ClAlPc-NE-treated LNCaP cells. Additionally, ClAlPc-NC or ClAlPc-NE and mitochondria showed a relatively high co-localization level. The cellular morphology did not change in the dark, but confocal micrographs recorded after PDT revealed that LNCaP cells treated with ClAlPc-NC or ClAlPc-NE underwent morphological alterations. Our preliminary in vitro studies reinforced the hypothesis that biocompatible theranostic ClAlPc-loaded nanocarriers could act as an attractive photosensitizer system in PDT and could serve as an interesting molecular probe for the early diagnosis of prostate cancer and other carcinomas. Copyright © 2017 Elsevier B.V. All rights reserved.

Prostate-targeted biodegradable nanoparticles loaded with androgen receptor silencing constructs eradicate xenograft tumors in mice

PubMed Central

Yang, Jun; Xie, Sheng-Xue; Huang, Yiling; Ling, Min; Liu, Jihong; Ran, Yali; Wang, Yanlin; Thrasher, J Brantley; Berkland, Cory; Li, Benyi

2012-01-01

Background Prostate cancer is the major cause of cancer death in men and the androgen receptor (AR) has been shown to play a critical role in the progression of the disease. Our previous reports showed that knocking down the expression of the AR gene using a siRNA-based approach in prostate cancer cells led to apoptotic cell death and xenograft tumor eradication. In this study, we utilized a biodegradable nanoparticle to deliver the therapeutic AR shRNA construct specifically to prostate cancer cells. Materials & methods The biodegradable nanoparticles were fabricated using a poly(dl-lactic-co-glycolic acid) polymer and the AR shRNA constructs were loaded inside the particles. The surface of the nanoparticles were then conjugated with prostate-specific membrane antigen aptamer A10 for prostate cancer cell-specific targeting. Results A10-conjugation largely enhanced cellular uptake of nanoparticles in both cell culture- and xenograft-based models. The efficacy of AR shRNA encapsulated in nanoparticles on AR gene silencing was confirmed in PC-3/AR-derived xenografts in nude mice. The therapeutic property of A10-conjugated AR shRNA-loaded nanoparticles was evaluated in xenograft models with different prostate cancer cell lines: 22RV1, LAPC-4 and LNCaP. Upon two injections of the AR shRNA-loaded nanoparticles, rapid tumor regression was observed over 2 weeks. Consistent with previous reports, A10 aptamer conjugation significantly enhanced xenograft tumor regression compared with nonconjugated nanoparticles. Discussion These data demonstrated that tissue-specific delivery of AR shRNA using a biodegradable nanoparticle approach represents a novel therapy for life-threatening prostate cancers. PMID:22583574

NFI Transcription Factors Interact with FOXA1 to Regulate Prostate-Specific Gene Expression

PubMed Central

Elliott, Amicia D.; DeGraff, David J.; Anderson, Philip D.; Anumanthan, Govindaraj; Yamashita, Hironobu; Sun, Qian; Friedman, David B.; Hachey, David L.; Yu, Xiuping; Sheehan, Jonathan H.; Ahn, Jung-Mo; Raj, Ganesh V.; Piston, David W.; Gronostajski, Richard M.; Matusik, Robert J.

2014-01-01

Androgen receptor (AR) action throughout prostate development and in maintenance of the prostatic epithelium is partly controlled by interactions between AR and forkhead box (FOX) transcription factors, particularly FOXA1. We sought to identity additional FOXA1 binding partners that may mediate prostate-specific gene expression. Here we identify the nuclear factor I (NFI) family of transcription factors as novel FOXA1 binding proteins. All four family members (NFIA, NFIB, NFIC, and NFIX) can interact with FOXA1, and knockdown studies in androgen-dependent LNCaP cells determined that modulating expression of NFI family members results in changes in AR target gene expression. This effect is probably mediated by binding of NFI family members to AR target gene promoters, because chromatin immunoprecipitation (ChIP) studies found that NFIB bound to the prostate-specific antigen enhancer. Förster resonance energy transfer studies revealed that FOXA1 is capable of bringing AR and NFIX into proximity, indicating that FOXA1 facilitates the AR and NFI interaction by bridging the complex. To determine the extent to which NFI family members regulate AR/FOXA1 target genes, motif analysis of publicly available data for ChIP followed by sequencing was undertaken. This analysis revealed that 34.4% of peaks bound by AR and FOXA1 contain NFI binding sites. Validation of 8 of these peaks by ChIP revealed that NFI family members can bind 6 of these predicted genomic elements, and 4 of the 8 associated genes undergo gene expression changes as a result of individual NFI knockdown. These observations suggest that NFI regulation of FOXA1/AR action is a frequent event, with individual family members playing distinct roles in AR target gene expression. PMID:24801505

Targeting of folate-conjugated liposomes with co-entrapped drugs to prostate cancer cells via prostate-specific membrane antigen (PSMA).

PubMed

Patil, Yogita; Shmeeda, Hilary; Amitay, Yasmine; Ohana, Patricia; Kumar, Saran; Gabizon, Alberto

2018-04-19

Folate-targeted liposomes (FTL) were tested as drug delivery vehicles to PSMA-positive cancer cells. We used FL with co-entrapped mitomycin C lipophilic prodrug (MLP) and doxorubicin (DOX), and the LNCaP prostate cancer cell line which expresses PSMA but is negative for folate receptor. A major increase in cell drug levels was observed when LNCaP cells were incubated with FTL as compared to non-targeted liposomes (NTL). MLP was activated to mitomycin C, and intracellular and nuclear fluorescence of DOX was detected, indicating FTL processing and drug bioavailability. PMPA (2-(phosphonomethyl)-pentanedioic acid), a specific inhibitor of PSMA, blocked the uptake of FTL into LNCaP cells, but did not affect the uptake of FTL into PSMA-deficient and folate receptor-positive KB cells. The cytotoxic activity of drug-loaded FTL was found significantly enhanced when compared to NTL in LNCaP cells. FTL may provide a new tool for targeted therapy of cancers that over-express the PSMA receptor. Copyright © 2018. Published by Elsevier Inc.

Nandrolone decreases mu opioid receptor expression in SH-SY5Y human neuroblastoma cells.

PubMed

Guarino, Goffredo; Spampinato, Santi

2008-07-16

Nandrolone and other anabolic androgenic steroids alter the expression and function of neurotransmitter systems and contribute to drug dependence. Nandrolone treatment (10-10 M) caused a time-dependent and concentration-dependent downregulation of mu opioid receptor (MOPr) transcripts in SH-SY5Y human neuroblastoma cells. This effect was prevented by the androgen receptor antagonist hydroxyflutamide. Receptor binding assays confirmed a decrease in MOPr of approximately 40% in nandrolone-treated cells. Treatment with actinomycin D (10 (-5)M), a transcription inhibitor, revealed that nandrolone might regulate MOPr mRNA stability. In SH-SY5Y cells transfected with a human MOPr luciferase promoter/reporter construct, nandrolone did not alter the rate of gene transcription. These results suggest that nandrolone may regulate MOPr expression through posttranscriptional mechanisms requiring the androgen receptor.

PCOTH, a novel gene overexpressed in prostate cancers, promotes prostate cancer cell growth through phosphorylation of oncoprotein TAF-Ibeta/SET.

PubMed

Anazawa, Yoshio; Nakagawa, Hidewaki; Furihara, Mutsuo; Ashida, Shingo; Tamura, Kenji; Yoshioka, Hiroki; Shuin, Taro; Fujioka, Tomoaki; Katagiri, Toyomasa; Nakamura, Yusuke

2005-06-01

Through genome-wide cDNA microarray analysis coupled with microdissection of prostate cancer cells, we identified a novel gene, prostate collagen triple helix (PCOTH), showing overexpression in prostate cancer cells and its precursor cells, prostatic intraepithelial neoplasia (PIN). Immunohistochemical analysis using polyclonal anti-PCOTH antibody confirmed elevated expression of PCOTH, a 100-amino-acid protein containing collagen triple-helix repeats, in prostate cancer cells and PINs. Knocking down PCOTH expression by small interfering RNA (siRNA) resulted in drastic attenuation of prostate cancer cell growth, and concordantly, LNCaP derivative cells that were designed to constitutively express exogenous PCOTH showed higher growth rate than LNCaP cells transfected with mock vector, suggesting the growth-promoting effect of PCOTH on prostate cancer cell. To investigate the biological mechanisms of this growth-promoting effect, we applied two-dimensional differential gel electrophoresis (2D-DIGE) to analyze the phospho-protein fractions in LNCaP cells transfected with PCOTH. We found that the phosphorylation level of oncoprotein TAF-Ibeta/SET was significantly elevated in LNCaP cells transfected with PCOTH than control LNCaP cells, and these findings were confirmed by Western blotting and in-gel kinase assay. Furthermore, knockdown of endogenous TAF-Ibeta expression by siRNA also attenuated viability of prostate cancer cells as well. These findings suggest that PCOTH is involved in growth and survival of prostate cancer cells thorough, in parts, the TAF-Ibeta pathway, and that this molecule should be a promising target for development of new therapeutic strategies for prostate cancers.

Development of Protein Degradation Inducers of Androgen Receptor by Conjugation of Androgen Receptor Ligands and Inhibitor of Apoptosis Protein Ligands.

PubMed

Shibata, Norihito; Nagai, Katsunori; Morita, Yoko; Ujikawa, Osamu; Ohoka, Nobumichi; Hattori, Takayuki; Koyama, Ryokichi; Sano, Osamu; Imaeda, Yasuhiro; Nara, Hiroshi; Cho, Nobuo; Naito, Mikihiko

2018-01-25

Targeted protein degradation using small molecules is a novel strategy for drug development. We have developed hybrid molecules named specific and nongenetic inhibitor of apoptosis protein [IAP]-dependent protein erasers (SNIPERs) that recruit IAP ubiquitin ligases to degrade target proteins. Here, we show novel SNIPERs capable of inducing proteasomal degradation of the androgen receptor (AR). Through derivatization of the SNIPER(AR) molecule at the AR ligand and IAP ligand and linker, we developed 42a (SNIPER(AR)-51), which shows effective protein knockdown activity against AR. Consistent with the degradation of the AR protein, 42a inhibits AR-mediated gene expression and proliferation of androgen-dependent prostate cancer cells. In addition, 42a efficiently induces caspase activation and apoptosis in prostate cancer cells, which was not observed in the cells treated with AR antagonists. These results suggest that SNIPER(AR)s could be leads for an anticancer drug against prostate cancers that exhibit AR-dependent proliferation.

Small molecule screening reveals a transcription-independent pro-survival function of androgen receptor in castration-resistant prostate cancer

PubMed Central

Narizhneva, Natalia V.; Tararova, Natalia D.; Ryabokon, Petro; Shyshynova, Inna; Prokvolit, Anatoly; Komarov, Pavel G.; Purmal, Andrei A.; Gudkov, Andrei V.; Gurova, Katerina V.

2010-01-01

In prostate cancer (PCa) patients, initial responsiveness to androgen deprivation therapy is frequently followed by relapse due to development of treatment-resistant androgen-independent PCa. This is typically associated with acquisition of mutations in AR that allow activity as a transcription factor in the absence of ligand, indicating that androgen-independent PCa remains dependent on AR function. Our strategy to effectively target AR in androgen-independent PCa involved using a cell-based readout to isolate small molecules that inhibit AR transactivation function through mechanisms other than modulation of ligand binding. A number of the identified inhibitors were toxic to AR-expressing PCa cells regardless of their androgen dependence. Among these, some only suppressed PCa cell growth (ARTIS), while others induced cell death (ARTIK). ARTIK, but not ARTIS, compounds caused disappearance of AR protein from treated cells. siRNA against AR behaved like ARTIK compounds, while a dominant negative AR mutant that prevents AR-mediated transactivation but does not eliminate the protein showed only a growth suppressive effect. These observations reveal a transcription-independent function of AR that is essential for PCa cell viability and, therefore, is an ideal target for anti-PCa treatment. Indeed, several of the identified AR inhibitors demonstrated in vivo efficacy in mouse models of PCa and are candidates for pharmacologic optimization. PMID:19946220

Radio-sensitization of Prostate Cancer Cells by Monensin Treatment and its associated Gene Expression Profiling Changes

NASA Technical Reports Server (NTRS)

Zhang Ye; Rohde, Larry H.; Wu, Honglu

2008-01-01

Radio-resistant or recurrent prostate cancer represents a serious health risk for approximately 20%-30% of patients treated with primary radiation therapy for clinically localized prostate cancer. Here, we investigated the effect of monensin on sensitizing radiation mediated cell killing of two radio-resistant prostate cell lines Lncap (P53+ and AR+) and PC3 (P53- and AR-). Treatment with monensin alone (5 micromoles-20 micromoles) showed a significant direct cell killing of Lncap (10-30%), but not PC3 cells. Monensin was also shown to successfully sensitize Lncap cells to X-ray radiation (2Gy-10Gy) mediated cell death, up to 50% of killing with the combined treatment. To better understand the mechanisms of radio-resistance of these two cell lines and their different response to monensin, the apoptosis related gene expression profiles in both cell lines were analyzed using cDNA PCR array. Without any treatment, PC3 showed a much higher expression level of antiapoptosis genes than Lncap in the BCL2 family, the caspase/card family and the TNF ligand/receptor family. At 2 hr after 20 micormolar monensin treatment alone, only the TRAF and CIDE family showed a greater induction in Lncap cells than in PC3. Exposures to 10 Gy X-rays alone of Lncap cells significantly induced gene expression levels in the death and death receptor domain family, the TNF ligand and receptor family, and apoptotic group of BCL2 family; whereas exposures of PC3 induced only the expression of genes in the anti-apoptosis group of CASP and CARD family. Furthermore, we selectively suppressed the expression of several anti-apoptosis genes (BCL-xl, Bcl2A1, BIRC2, BIRC3 and CASP2) in PC3 cells by using the siRNA treatment. Exposure to 10Gy X-rays alone showed an enhanced cell killing (about 15%) in BCL-x1 silenced cells, but not in cells with siRNA treatment targeting other anti-apoptosis genes. We also exposed PC3 cells to protons in the Bragg peak region to compare the effectiveness of cell killing of X-rays. Interestingly, in comparison to X-rays, protons significantly reduced the gene expression in the anti-apoptosis family, suggesting that proton treatment may be more effective for PC3 cells. As a conclusion, monensin was found to sensitize Lncap cells, but not PC3, and over-expression of Bcl-xl cells may be responsible for the radio- or chemo-resistance characteristics of PC3 cells.

Androgen-Induced Cell Migration: Role of Androgen Receptor/Filamin A Association

PubMed Central

Castoria, Gabriella; D'Amato, Loredana; Ciociola, Alessandra; Giovannelli, Pia; Giraldi, Tiziana; Sepe, Leandra; Paolella, Giovanni; Barone, Maria Vittoria; Migliaccio, Antimo; Auricchio, Ferdinando

2011-01-01

Background Androgen receptor (AR) controls male morphogenesis, gametogenesis and prostate growth as well as development of prostate cancer. These findings support a role for AR in cell migration and invasiveness. However, the molecular mechanism involved in AR-mediated cell migration still remains elusive. Methodology/Principal Findings Mouse embryo NIH3T3 fibroblasts and highly metastatic human fibrosarcoma HT1080 cells harbor low levels of transcriptionally incompetent AR. We now report that, through extra nuclear action, AR triggers migration of both cell types upon stimulation with physiological concentrations of the androgen R1881. We analyzed the initial events leading to androgen-induced cell migration and observed that challenging NIH3T3 cells with 10 nM R1881 rapidly induces interaction of AR with filamin A (FlnA) at cytoskeleton. AR/FlnA complex recruits integrin beta 1, thus activating its dependent cascade. Silencing of AR, FlnA and integrin beta 1 shows that this ternary complex controls focal adhesion kinase (FAK), paxillin and Rac, thereby driving cell migration. FAK-null fibroblasts migrate poorly and Rac inhibition by EHT impairs motility of androgen-treated NIH3T3 cells. Interestingly, FAK and Rac activation by androgens are independent of each other. Findings in human fibrosarcoma HT1080 cells strengthen the role of Rac in androgen signaling. The Rac inhibitor significantly impairs androgen-induced migration in these cells. A mutant AR, deleted of the sequence interacting with FlnA, fails to mediate FAK activation and paxillin tyrosine phosphorylation in androgen-stimulated cells, further reinforcing the role of AR/FlnA interaction in androgen-mediated motility. Conclusions/Significance The present report, for the first time, indicates that the extra nuclear AR/FlnA/integrin beta 1 complex is the key by which androgen activates signaling leading to cell migration. Assembly of this ternary complex may control organ development and prostate cancer metastasis. PMID:21359179

CXCR6 is expressed in human prostate cancer in vivo and is involved in the in vitro invasion of PC3 and LNCap cells.

PubMed

Hu, Weidong; Zhen, Xinming; Xiong, Bin; Wang, Bicheng; Zhang, Weibing; Zhou, Wenhui

2008-07-01

In spite of the clinical importance of prostate cancer (PCa) bone metastasis, the precise mechanisms for the directed migration of malignant cells remain unclear. In the present study, the expression of CXCR6 in human PCa and benign prostatic hyperplasia samples, and the expression of CXCL16 in human osseous tissues were determined by immunohistochemistry. It was found that the level of CXCR6 protein expression was elevated in human malignant prostate tumors, and CXCL16 was expressed positively by human osteocytes in vivo. The in vitro experiments further confirmed that the PCa cell lines PC3 and LNCap expressed CXCR6 at both the mRNA and protein levels, and exogenous CXCL16 has the potential to stimulate the invasion of PC3 and LNCap. To further elucidate the role of the CXCL16-CXCR6 axis in PCa progression, we compared the expression of CXCR6 and CXCR4 in human PCa tissues and the effects of CXCL16 and CXCL12 on the in vitro invasion of PC3 and LNCap cells. It was shown that CXCR6 and CXCR4 proteins were coexpressed and elevated in human PCa samples, and CXCL16 and CXCL12 promoted the invasion of PC3 and LNCap via their respective receptors. Furthermore, in contrast to CXCL12, which enhanced the activity of matrix metalloproteinase (MMP) 9 and MMP2 in PC3 and LNCap, CXCL16 ligation resulted in stronger MMP9 and MMP2 activity in LNCap but not in PC3. Our results suggest that besides CXCL12/CXCR4, CXCL16/CXCR6 might be another important factor involved in PCa bone metastasis.

Androgen deprivation therapy sensitizes prostate cancer cells to T-cell killing through androgen receptor dependent modulation of the apoptotic pathway

PubMed Central

Ardiani, Andressa; Gameiro, Sofia R.; Kwilas, Anna R.; Donahue, Renee N.; Hodge, James W.

2014-01-01

Despite recent advances in diagnosis and management, prostrate cancer remains the second most common cause of death from cancer in American men, after lung cancer. Failure of chemotherapies and hormone-deprivation therapies is the major cause of death in patients with castration-resistant prostate cancer (CRPC). Currently, the androgen inhibitors enzalutamide and abiraterone are approved for treatment of metastatic CRPC. Here we show for the first time that both enzalutamide and abiraterone render prostate tumor cells more sensitive to T cell-mediated lysis through immunogenic modulation, and that these immunomodulatory activities are androgen receptor (AR)-dependent. In studies reported here, the NAIP gene was significantly down-regulated in human prostate tumor cells treated in vitro and in vivo with enzalutamide. Functional analysis revealed that NAIP played a critical role in inducing CTL sensitivity. Amplification of AR is a major mechanism of resistance to androgen-deprivation therapy (ADT). Here, we show that enzalutamide enhances sensitivity to immune-mediated killing of prostate tumor cells that overexpress AR. The immunomodulatory properties of enzalutamide and abiraterone provide a rationale for their use in combination with immunotherapeutic agents in CRPC, especially for patients with minimal response to enzalutamide or abiraterone alone, or for patients who have developed resistance to ADT. PMID:25344864

A clinical data validated mathematical model of prostate cancer growth under intermittent androgen suppression therapy

NASA Astrophysics Data System (ADS)

Portz, Travis; Kuang, Yang; Nagy, John D.

2012-03-01

Prostate cancer is commonly treated by a form of hormone therapy called androgen suppression. This form of treatment, while successful at reducing the cancer cell population, adversely affects quality of life and typically leads to a recurrence of the cancer in an androgen-independent form. Intermittent androgen suppression aims to alleviate some of these adverse affects by cycling the patient on and off treatment. Clinical studies have suggested that intermittent therapy is capable of maintaining androgen dependence over multiple treatment cycles while increasing quality of life during off-treatment periods. This paper presents a mathematical model of prostate cancer to study the dynamics of androgen suppression therapy and the production of prostate-specific antigen (PSA), a clinical marker for prostate cancer. Preliminary models were based on the assumption of an androgen-independent (AI) cell population with constant net growth rate. These models gave poor accuracy when fitting clinical data during simulation. The final model presented hypothesizes an AI population with increased sensitivity to low levels of androgen. It also hypothesizes that PSA production is heavily dependent on androgen. The high level of accuracy in fitting clinical data with this model appears to confirm these hypotheses, which are also consistent with biological evidence.

Fisetin, a novel dietary flavonoid, causes apoptosis and cell cycle arrest in human prostate cancer LNCaP cells

PubMed Central

Khan, Naghma; Afaq, Farrukh; Syed, Deeba N.; Mukhtar, Hasan

2008-01-01

Novel dietary agents for prevention and therapy of prostate cancer (PCa) are desired. The aim of this study was to determine the effect of fisetin, a tetrahydroxyflavone, on inhibition of cell growth and induction of apoptosis in human PCa cells. Treatment of fisetin (10–60 μM, 48 h) was found to result in a decrease in the viability of LNCaP, CWR22Rυ1 and PC-3 cells but had only minimal effects on normal prostate epithelial cells as assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide assay. Treatment of LNCaP cells with fisetin also resulted in G1-phase arrest that was associated with a marked decrease in the protein expression of cyclins D1, D2 and E and their activating partner cyclin-dependent kinases 2, 4 and 6 with concomitant induction of WAF1/p21 and KIP1/p27. Fisetin treatment also resulted in induction of apoptosis, poly (ADP-ribose) polymerase (PARP) cleavage, modulation in the expressions of Bcl-2 family proteins, inhibition of phosphatidyl inositol 3-kinase and phosphorylation of Akt at Ser473 and Thr308. There was also induction of mitochondrial release of cytochrome c into cytosol, downregulation of X-linked inhibitor of apoptosis protein and upregulation of second mitochondria-derived activator of caspase/direct inhibitor of apoptosis-binding protein with low pI on treatment of cells with fisetin. Treatment of cells with fisetin also resulted in significant activation of caspases-3, -8 and -9. Pretreatment of cells with caspase inhibitor (Z-VAD-FMK) blocked fisetin-induced activation of caspases. These data provide the first evidence that fisetin could be developed as an agent against PCa. PMID:18359761

Activation of NF-kappa B Signaling Promotes Growth of Prostate Cancer Cells in Bone

PubMed Central

Jin, Renjie; Sterling, Julie A.; Edwards, James R.; DeGraff, David J.; Lee, Changki; Park, Serk In; Matusik, Robert J.

2013-01-01

Patients with advanced prostate cancer almost invariably develop osseous metastasis. Although many studies indicate that the activation of NF-κB signaling appears to be correlated with advanced cancer and promotes tumor metastasis by influencing tumor cell migration and angiogenesis, the influence of altered NF-κB signaling in prostate cancer cells within boney metastatic lesions is not clearly understood. While C4-2B and PC3 prostate cancer cells grow well in the bone, LNCaP cells are difficult to grow in murine bone following intraskeletal injection. Our studies show that when compared to LNCaP, NF-κB activity is significantly higher in C4-2B and PC3, and that the activation of NF-κB signaling in prostate cancer cells resulted in the increased expression of the osteoclast inducing genes PTHrP and RANKL. Further, conditioned medium derived from NF-κB activated LNCaP cells induce osteoclast differentiation. In addition, inactivation of NF-κB signaling in prostate cancer cells inhibited tumor formation in the bone, both in the osteolytic PC3 and osteoblastic/osteoclastic mixed C4-2B cells; while the activation of NF-κB signaling in LNCaP cells promoted tumor establishment and proliferation in the bone. The activation of NF-κB in LNCaP cells resulted in the formation of an osteoblastic/osteoclastic mixed tumor with increased osteoclasts surrounding the new formed bone, similar to metastases commonly seen in patients with prostate cancer. These results indicate that osteoclastic reaction is required even in the osteoblastic cancer cells and the activation of NF-κB signaling in prostate cancer cells increases osteoclastogenesis by up-regulating osteoclastogenic genes, thereby contributing to bone metastatic formation. PMID:23577181

Inflammatory cytokines IL-17 and TNF-α up-regulate PD-L1 expression in human prostate and colon cancer cells

PubMed Central

Wang, Xun; Yang, Lingyun; Huang, Feng; Zhang, Qiuyang; Liu, Sen; Ma, Lin; You, Zongbing

2017-01-01

Programmed cell death protein 1 (PD-1) acts on PD-1 ligands (PD-L1 and PD-L2) to suppress activation of cytotoxic T lymphocytes. Interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) are co-expressed by T helper 17 (TH17) cells in many tumors. The purpose of this study was to test if IL-17 and TNF-α may synergistically induce PD-L1 expression in human prostate cancer LNCaP and human colon cancer HCT116 cell lines. We found that IL-17 did not induce PD-L1 mRNA expression, but up-regulated PD-L1 protein expression in HCT116 and LNCaP cells. TNF-α induced PD-L1 mRNA and protein expression in both cell lines. Neither IL-17 nor TNF-α induced PD-L2 mRNA or protein expression. IL-17 and TNF-α acted individually rather than cooperatively in induction of PD-L1 expression. IL-17 and/or TNF-α activated AKT, nuclear factor-κB (NF-κB), and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling pathways in HCT116 cells, whereas only NF-κB signaling was activated in LNCaP cells. NF-κB inhibitor could diminish PD-L1 protein expression induced by IL-17 and/or TNF-α in both HCT116 and LNCaP cell lines. ERK1/2 inhibitor could also reduce PD-L1 protein expression induced by IL-17 and/or TNF-α in HCT116 cells, while AKT inhibitor could abolish PD-L1 protein expression induced by IL-17 and/or TNF-α in LNCaP cells. These results suggest that IL-17 and TNF-α act individually rather than cooperatively through activation of NF-κB and ERK1/2 signaling to up-regulate PD-L1 expression in HCT116 cells, while the two inflammatory cytokines act through activation of NF-κB signaling, in the presence of AKT activity, to up-regulate PD-L1 expression in LNCaP cells. PMID:28223102

Synthesis, characterization, and subcellular localization studies of amino acid-substituted porphyrinic pigments

NASA Astrophysics Data System (ADS)

van Diggelen, Lisa; Khin, Hnin; Conner, Kip; Shao, Jenny; Sweezy, Margaretta; Jung, Anna H.; Isaac, Meden; Simonis, Ursula

2009-06-01

Stopping cancer in its path occurs when photosensitizers (PSs) induce apoptotic cell death after their exposure to light and the subsequent formation of reactive oxygen species. In pursuit of our hypothesis that mitochondrial localizing PSs will enhance the efficacy of the photosensitizing process in photodynamic therapy, since they provoke cell death by inducing apoptosis, we synthesized and characterized tetraphenylporphyrins (TPPs) that are substituted at the paraphenyl positions by two amino acids and two fluoro or hydroxyl groups, respectively. They were prepared according to the Lindsey-modified Adler-Longo methodology using trifluoromethanesulfonylchloride (CF3SO2Cl) as a catalyst instead of trifluoroacetic acid. The use of CF3SO2Cl yielded cleaner products in significantly higher yields. During the synthesis, not only the yields and work-up procedure of the TPPs were improved by using CF3SO2Cl as a catalyst, but also a better means of synthesizing the precursor dipyrromethanes was tested by using indium(III) chloride. Column chromatography, HPLC, and NMR spectroscopy were used to separate and characterize the di-amino acid-dihydroxy, or difluoro-substituted porphyrins and to ascertain their purity before subcellular localization studies were carried out. Studies using androgen-sensitive human prostate adenocarcinoma cells LNCaP revealed that certain amino acid substituted porphyrins that are positively charged in the slightly acidic medium of cancer cells are very useful in shedding light on the targets of TPPs in subcellular organelles of cancer cells. Although some of these compounds have properties of promising photosensitizers by revealing increased water solubility, acidic properties, and innate ability to provoke cell death by apoptosis, the cell killing efficacy of these TPPs is low. This correlates with their subcellular localization. The di-amino acid, di-hydroxy substituted TPPs localize mainly to the lysosomes, whereas the di-fluoro-substituted TPPs are trapped in the plasma membrane. Only a pheophorbide derivative recently synthesized in our laboratory localized to the mitochondria of LNCaP cells, which are at the center of cell death as is reflected in their key role during apoptosis, thus reassuring our attempts toward rational drug design.

KML001 Induces Apoptosis and Autophagic Cell Death in Prostate Cancer Cells via Oxidative Stress Pathway

PubMed Central

You, Dalsan; Kim, Yunlim; Jang, Myoung Jin; Lee, Chunwoo; Jeong, In Gab; Cho, Yong Mee; Hwang, Jung Jin; Hong, Jun Hyuk; Ahn, Hanjong; Kim, Choung-Soo

2015-01-01

We investigated the effects of KML001 (NaAsO2, sodium metaarsenite, Kominox), an orally bioavailable arsenic compound, on the growth and death of human prostate cancer cells and its mechanism of action. Growth inhibition was assessed by cytotoxicity assays in the presence or absence of inhibitor of apoptosis, inhibitor of autophagy or antioxidant N-Acetyl-L-cysteine to study mechanism of cell death induced by KML001 in PC3, DU145 and LNCaP prostate cancer cell lines. Electron microscopy, flow cytometry and Western blotting were used to study apoptotic and autophagic mechanisms. The DU145 xenograft model was used to determine the efficacy of KML001 in vivo. KML001 decreased the viability of cells and increased the percentage of annexin V-positive cells dose-dependently in prostate cancer cells, and LNCaP cells were more sensitive to KML001 than PC3 or DU145 cells. Electron microscopy revealed typical apoptotic characters and autophagic vacuoles in cells treated with KML001. Exposure to KML001 in prostate cancer cells induced apoptosis and autophagy in a time- and dose-dependent manner. KML001 induced dose-dependent accumulation of reactive oxygen species, and scavenging the reactive oxygen species with N-Acetyl-L-cysteine reduced LC3 and cleaved poly (ADP-ribose) polymerase. KML001 significantly inhibited tumor growth in the DU145 xenograft model. In addition, significant decrease of proliferation and significant increases of apoptosis and autophagy were observed in KML001-treated tumors than in vehicle-treated tumors. Exposure of human prostate cancer cells to KML001 induced both apoptosis and autophagic cell death via oxidative stress pathway. And KML001 had an antiproliferative effect on DU145 cells in xenograft mice. PMID:26352139

KML001 Induces Apoptosis and Autophagic Cell Death in Prostate Cancer Cells via Oxidative Stress Pathway.

PubMed

You, Dalsan; Kim, Yunlim; Jang, Myoung Jin; Lee, Chunwoo; Jeong, In Gab; Cho, Yong Mee; Hwang, Jung Jin; Hong, Jun Hyuk; Ahn, Hanjong; Kim, Choung-Soo

2015-01-01

We investigated the effects of KML001 (NaAsO2, sodium metaarsenite, Kominox), an orally bioavailable arsenic compound, on the growth and death of human prostate cancer cells and its mechanism of action. Growth inhibition was assessed by cytotoxicity assays in the presence or absence of inhibitor of apoptosis, inhibitor of autophagy or antioxidant N-Acetyl-L-cysteine to study mechanism of cell death induced by KML001 in PC3, DU145 and LNCaP prostate cancer cell lines. Electron microscopy, flow cytometry and Western blotting were used to study apoptotic and autophagic mechanisms. The DU145 xenograft model was used to determine the efficacy of KML001 in vivo. KML001 decreased the viability of cells and increased the percentage of annexin V-positive cells dose-dependently in prostate cancer cells, and LNCaP cells were more sensitive to KML001 than PC3 or DU145 cells. Electron microscopy revealed typical apoptotic characters and autophagic vacuoles in cells treated with KML001. Exposure to KML001 in prostate cancer cells induced apoptosis and autophagy in a time- and dose-dependent manner. KML001 induced dose-dependent accumulation of reactive oxygen species, and scavenging the reactive oxygen species with N-Acetyl-L-cysteine reduced LC3 and cleaved poly (ADP-ribose) polymerase. KML001 significantly inhibited tumor growth in the DU145 xenograft model. In addition, significant decrease of proliferation and significant increases of apoptosis and autophagy were observed in KML001-treated tumors than in vehicle-treated tumors. Exposure of human prostate cancer cells to KML001 induced both apoptosis and autophagic cell death via oxidative stress pathway. And KML001 had an antiproliferative effect on DU145 cells in xenograft mice.

Targeted BikDD expression kills androgen-dependent and castration-resistant prostate cancer cells

PubMed Central

Xie, Xiaoming; Kong, Yanan; Tang, Hailin; Yang, Lu; Hsu, Jennifer L; Hung, Mien-Chie

2014-01-01

Targeted gene therapy is a promising approach for treating prostate cancer after the discovery of prostate cancer-specific promoters such as prostate-specific antigen, rat probasin, and human glandular kallikrein. However, these promoters are androgen-dependent, and after castration or androgen ablation therapy, they become much less active or sometimes inactive. Importantly, the disease will inevitably progress from androgen-dependent (ADPC) to castration-resistant prostate cancer (CRPC) at which treatments fail and high mortality ensues. Therefore, it is critical to develop a targeted gene therapy strategy that is effective in both ADPC and CRPC to eradicate recurrent prostate tumors. The human telomerase reverse transcriptase-VP16-Gal4-WPRE integrated systemic amplifier composite (T-VISA) vector we previously developed which targets transgene expression in ovarian and breast cancer is also active in prostate cancer. To further improve its effectiveness based on androgen response in ADPC progression, the ARR2 element (two copies of androgen response region from rat probasin promoter) was incorporated into T-VISA to produce AT-VISA. Under androgen analog (R1881) stimulation, the activity of AT-VISA was increased to a level greater than or comparable to the cytomegalovirus (CMV) promoter in ADPC and CRPC cells, respectively. Importantly, AT-VISA demonstrated little or no expression in normal cells. Systemic administration of AT-VISA-BikDD encapsulated in liposomes repressed prostate tumor growth and prolonged mouse survival in orthotopic animal models as well as in the transgenic adenocarcinoma mouse prostate model, indicating that AT-VISA-BikDD has therapeutic potential to treat ADPC and CRPC safely and effectively in preclinical setting. PMID:24785255

Molecular effects of soy phytoalexin glyceollins in human prostate cancer cells LNCaP

USDA-ARS?s Scientific Manuscript database

Glyceollins are soy–derived phytoalexins that have been proposed to be candidate cancer preventive compounds. The effect of the glyceollins on prostate cancer is unknown. The present study examined the molecular effects of soy phytoalexins, glyceollins, on the human prostate cancer cell line LNCaP t...

A partial differential equation model and its reduction to an ordinary differential equation model for prostate tumor growth under intermittent hormone therapy.

PubMed

Tao, Youshan; Guo, Qian; Aihara, Kazuyuki

2014-10-01

Hormonal therapy with androgen suppression is a common treatment for advanced prostate tumors. The emergence of androgen-independent cells, however, leads to a tumor relapse under a condition of long-term androgen deprivation. Clinical trials suggest that intermittent androgen suppression (IAS) with alternating on- and off-treatment periods can delay the relapse when compared with continuous androgen suppression (CAS). In this paper, we propose a mathematical model for prostate tumor growth under IAS therapy. The model elucidates initial hormone sensitivity, an eventual relapse of a tumor under CAS therapy, and a delay of a relapse under IAS therapy, which are due to the coexistence of androgen-dependent cells, androgen-independent cells resulting from reversible changes by adaptation, and androgen-independent cells resulting from irreversible changes by genetic mutations. The model is formulated as a free boundary problem of partial differential equations that describe the evolution of populations of the abovementioned three types of cells during on-treatment periods and off-treatment periods. Moreover, the model can be transformed into a piecewise linear ordinary differential equation model by introducing three new volume variables, and the study of the resulting model may help to devise optimal IAS schedules.

Orphan nuclear receptor TLX contributes to androgen insensitivity in castration-resistant prostate cancer via its repression of androgen receptor transcription.

PubMed

Jia, Lin; Wu, Dinglan; Wang, Yuliang; You, Wenxing; Wang, Zhu; Xiao, Lijia; Cai, Ganhui; Xu, Zhenyu; Zou, Chang; Wang, Fei; Teoh, Jeremy Yuen-Chun; Ng, Chi-Fai; Yu, Shan; Chan, Franky L

2018-03-20

The metastatic castration-resistant prostate cancer (CRPC) is a lethal form of prostate cancer, in which the expression of androgen receptor (AR) is highly heterogeneous. Indeed, lower AR expression and attenuated AR signature activity is shown in CRPC tissues, especially in the subset of neuroendocrine prostate cancer (NEPC) and prostate cancer stem-like cells (PCSCs). However, the significance of AR downregulation in androgen insensitivity and de-differentiation of tumor cells in CRPC is poorly understood and much neglected. Our previous study shows that the orphan nuclear receptor TLX (NR2E1), which is upregulated in prostate cancer, plays an oncogenic role in prostate carcinogenesis by suppressing oncogene-induced senescence. In the present study, we further established that TLX exhibited an increased expression in metastatic CRPC. Further analyses showed that overexpression of TLX could confer resistance to androgen deprivation and anti-androgen in androgen-dependent prostate cancer cells in vitro and in vivo, whereas knockdown of endogenous TLX could potentiate the sensitivity to androgen deprivation and anti-androgen in prostate cancer cells. Our study revealed that the TLX-induced resistance to androgen deprivation and anti-androgen was mediated through its direct suppression of AR gene transcription and signaling in both androgen-stimulated and -unstimulated prostate cancer cells. We also characterized that TLX could bind directly to AR promoter and repress AR transcription by recruitment of histone modifiers, including HDAC1, HDAC3, and LSD1. Together, our present study shows, for the first time, that TLX can contribute to androgen insensitivity in CRPC via repression of AR gene transcription and signaling, and also implicates that targeting the druggable TLX may have a potential therapeutic significance in CRPC management, particularly in NEPC and PCSCs.

Beta 2-Microglobulin: A Novel Therapeutic Target for the Treatment of Human Prostate Cancer Bone Metastasis

DTIC Science & Technology

2009-03-14

H, Sodek J, Zhau HE, Chung LW. Human osteocalcin and bone sialoprotein mediating osteomimicry of prostate cancer cells: role of cAMP-dependent...with mesenchymal phenotype b2-m b2-Microglobulin BSP Bone sialoprotein C4-2 Lineage derivative cells from LNCaP C4-2B C4-2 cells metastasized to bone...OPN) and bone sialoprotein (BSP), and RANKL, collectively allow- ing cancer cells to survive and thrive in the bone microenvironment [7–9]. Previous

Atrazine activates multiple signaling pathways enhancing the rapid hCG-induced androgenesis in rat Leydig cells.

PubMed

Pogrmic-Majkic, Kristina; Fa, Svetlana; Samardzija, Dragana; Hrubik, Jelena; Kaisarevic, Sonja; Andric, Nebojsa

2016-08-10

Atrazine (ATR) is an endocrine disruptor that affects steroidogenic process, resulting in disruption of reproductive function of the male and female gonads. In this study, we used the primary culture of peripubertal Leydig cells to investigate the effect of ATR on the rapid androgen production stimulated by human chorionic gonadotropin (hCG). We demonstrated that ATR activated multiple signaling pathways enhancing the rapid hCG-stimulated androgen biosynthesis in Leydig cells. Low hCG concentration (0.25ng/mL) caused cAMP-independent, but ERK1/2-dependent increase in androgen production after 60min of incubation. Co-treatment with ATR for 60min enhanced the cAMP production in hCG-stimulated cells. Accumulation of androgens was prevented by addition of U0126, N-acetyl-l-cysteine and AG1478. Co-treatment with hCG and ATR for 60min did not alter steroidogenic acute regulatory protein (Star) mRNA level in Leydig cells. After 120min, hCG further increased androgenesis in Leydig cells that was sensitive to inhibition of the cAMP/PKA, ERK1/2 and ROS signaling pathways. Co-treatment with ATR for 120min further enhanced the hCG-induced androgen production, which was prevented by inhibition of the calcium, PKC and EGFR signaling cascades. After 120min, ATR enhanced the expression of Star mRNA in hCG-stimulated Leydig cells through activation of the PKA and PKC pathway. Collectively, these data suggest that exposure to ATR caused perturbations in multiple signaling pathways, thus enhancing the rapid hCG-dependent androgen biosynthesis in peripubertal Leydig cells. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Androgen receptor signaling and mutations in prostate cancer

PubMed Central

Koochekpour, Shahriar

2010-01-01

Normal and neoplastic growth of the prostate gland are dependent on androgen receptor (AR) expression and function. Androgenic activation of the AR, in association with its coregulatory factors, is the classical pathway that leads to transcriptional activity of AR target genes. Alternatively, cytoplasmic signaling crosstalk of AR by growth factors, neurotrophic peptides, cytokines or nonandrogenic hormones may have important roles in prostate carcinogenesis and in metastatic or androgen-independent (AI) progression of the disease. In addition, cross-modulation by various nuclear transcription factors acting through basal transcriptional machinery could positively or negatively affect the AR or AR target genes expression and activity. Androgen ablation leads to an initial favorable response in a significant number of patients; however, almost invariably patients relapse with an aggressive form of the disease known as castration-resistant or hormone-refractory prostate cancer (PCa). Understanding critical molecular events that lead PCa cells to resist androgen-deprivation therapy is essential in developing successful treatments for hormone-refractory disease. In a significant number of hormone-refractory patients, the AR is overexpressed, mutated or genomically amplified. These genetic alterations maintain an active presence for a highly sensitive AR, which is responsive to androgens, antiandrogens or nonandrogenic hormones and collectively confer a selective growth advantage to PCa cells. This review provides a brief synopsis of the AR structure, AR coregulators, posttranslational modifications of AR, duality of AR function in prostate epithelial and stromal cells, AR-dependent signaling, genetic changes in the form of somatic and germline mutations and their known functional significance in PCa cells and tissues. PMID:20711217

Annatto Tocotrienol Induces a Cytotoxic Effect on Human Prostate Cancer PC3 Cells via the Simultaneous Inhibition of Src and Stat3.

PubMed

Sugahara, Ryosuke; Sato, Ayami; Uchida, Asuka; Shiozawa, Shinya; Sato, Chiaki; Virgona, Nantiga; Yano, Tomohiro

2015-01-01

Prostate cancer is one of the most frequently occurring cancers and often acquires the potential of androgen-independent growth as a malignant phenotype. Androgen-independent prostate cancer has severe chemoresistance towards conventional chemotherapeutic agents, so a new treatment approach is required for curing such prostate cancer. In this context, the present study was undertaken to check if annatto tocotrienol (main component δ-tocotrienol) could suppress cell growth in human prostate cancer (PC3, androgen-independent type) cells via the inhibition of Src and Stat3. The tocotrienol showed cytotoxic effects on PC3 cells in a dose-dependent manner, and the effect depended on G1 arrest in the cell cycle and subsequent induction of apoptosis. In a cytotoxic dose, the tocotrienol suppressed cellular growth via the simultaneous inhibition of Src and Stat3. Similarly, the treatment combination of both Src and Stat3 inhibitors induced cytotoxic effects in PC3 cells in an additive manner compared to each by itself. With respect to cell cycle regulation and the induction of apoptosis, the combination treatment showed a similar effect to that of the tocotrienol treatment. These results suggest that annatto tocotrienol effectively induces cytotoxicity in androgen-independent prostate cancer cells via the suppression of Src and Stat3.

Smooth muscle cell-specific knockout of androgen receptor: a new model for prostatic disease.

PubMed

Welsh, Michelle; Moffat, Lindsey; McNeilly, Alan; Brownstein, David; Saunders, Philippa T K; Sharpe, Richard M; Smith, Lee B

2011-09-01

Androgen-driven stromal-epithelial interactions play a key role in normal prostate development and function as well as in the progression of common prostatic diseases such as benign prostatic hyperplasia and prostate cancer. However, exactly how, and via which cell type, androgens mediate their effects in the adult prostate remains unclear. This study investigated the role for smooth muscle (SM) androgen signaling in normal adult prostate homeostasis and function using mice in which androgen receptor was selectively ablated from prostatic SM cells. In adulthood the knockout (KO) mice displayed a 44% reduction in prostate weight and exhibited histological abnormalities such as hyperplasia, inflammation, fibrosis, and reduced expression of epithelial, SM, and stem cell identify markers (e.g. p63 reduced by 27% and Pten by 31%). These changes emerged beyond puberty and were not explained by changes in serum hormones. Furthermore, in response to exogenous estradiol, adult KO mice displayed an 8.5-fold greater increase in prostate weight than controls and developed urinary retention. KO mice also demonstrated a reduced response to castration compared with controls. Together these results demonstrate that prostate SM cells are vital in mediating androgen-driven stromal-epithelial interactions in adult mouse prostates, determining cell identity and function and limiting hormone-dependent epithelial cell proliferation. This novel mouse model provides new insight into the possible role for SM androgen action in prostate disease.

Aging up-regulates ARA55 in stromal cells, inducing androgen-mediated prostate cancer cell proliferation and migration.

PubMed

Zou, Qingsong; Cui, Di; Liang, Shengjie; Xia, Shujie; Jing, Yifeng; Han, Bangmin

2016-06-01

Stromal cells in the peripheral zone (PZ) of the prostate from older males (PZ-old) could significantly promote Prostate cancer (PCa) growth compared with stromal cells from young males (PZ-young). But the mechanism is still unknown. In the co-culture system with PZ-old cells, Pc3/Du145 cells showed advanced proliferation and migration after Dihydrotestosterone (DHT) incubation, but DHT didn't show the similar effect in PZ-young co-culture system. Also, higher androgen/AR signal pathway activity and AR-related cytokines secretion (FGF-2, KGF, IGF-1) were found in PZ-old cells. As AR exprssison was equivalent in PZ-old and PZ-young cells, we focused on Androgen receptor associated protein-55(ARA55), a stromal-specific androgen receptor (AR) coactivator. ARA55 expression was higher in PZ-old cells compared with PZ-young cells in vitro. After knocking down ARA55 expression in PZ-old cells, the PCa growth- promoting effect from the PZ-old cells was diminished, which may be explained by the decreased the progressive cytokines secretion (FGF-2, KGF, IGF-1) from PZ-old stromal cells. In vivo, the consistent results were also found: PZ-old cells promoted prostate cancer cells growth, but this effect receded when knocking down ARA55 expression in PZ-old cells. From our study, we found PZ stromal cells presented age-related effects in proliferation and migration of prostate cancer cells in the androgen/AR dependent manner. As aging increased, more ARA55 were expressed in PZ stromal cells, leading to more sensitive androgen/androgen receptor (AR) signal pathway, then constituting a more feasible environment to cancer cells.

Inflammatory cytokines IL-17 and TNF-α up-regulate PD-L1 expression in human prostate and colon cancer cells.

PubMed

Wang, Xun; Yang, Lingyun; Huang, Feng; Zhang, Qiuyang; Liu, Sen; Ma, Lin; You, Zongbing

2017-04-01

Programmed cell death protein 1 (PD-1) acts on PD-1 ligands (PD-L1 and PD-L2) to suppress activation of cytotoxic T lymphocytes. Interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) are co-expressed by T helper 17 (T H 17) cells in many tumors. The purpose of this study was to test if IL-17 and TNF-α may synergistically induce PD-L1 expression in human prostate cancer LNCaP and human colon cancer HCT116 cell lines. We found that IL-17 did not induce PD-L1 mRNA expression, but up-regulated PD-L1 protein expression in HCT116 and LNCaP cells. TNF-α induced PD-L1 mRNA and protein expression in both cell lines. Neither IL-17 nor TNF-α induced PD-L2 mRNA or protein expression. IL-17 and TNF-α acted individually rather than cooperatively in induction of PD-L1 expression. IL-17 and/or TNF-α activated AKT, nuclear factor-κB (NF-κB), and extracellular signal-regulated kinases 1/2 (ERK1/2) signaling pathways in HCT116 cells, whereas only NF-κB signaling was activated in LNCaP cells. NF-κB inhibitor could diminish PD-L1 protein expression induced by IL-17 and/or TNF-α in both HCT116 and LNCaP cell lines. ERK1/2 inhibitor could also reduce PD-L1 protein expression induced by IL-17 and/or TNF-α in HCT116 cells, while AKT inhibitor could abolish PD-L1 protein expression induced by IL-17 and/or TNF-α in LNCaP cells. These results suggest that IL-17 and TNF-α act individually rather than cooperatively through activation of NF-κB and ERK1/2 signaling to up-regulate PD-L1 expression in HCT116 cells, while the two inflammatory cytokines act through activation of NF-κB signaling, in the presence of AKT activity, to up-regulate PD-L1 expression in LNCaP cells. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Characterization of a novel novobiocin analogue as a putative C-terminal inhibitor of heat shock protein 90 in prostate cancer cells.

PubMed

Matthews, Shawna B; Vielhauer, George A; Manthe, Craig A; Chaguturu, Vamsee K; Szabla, Kristen; Matts, Robert L; Donnelly, Alison C; Blagg, Brian S J; Holzbeierlein, Jeffrey M

2010-01-01

Hsp90 is important in the folding, maturation and stabilization of pro-tumorigenic client proteins and represents a viable drug target for the design of chemotherapies. Previously, we reported the development of novobiocin analogues designed to inhibit the C-terminal portion of Hsp90, which demonstrated the ability to decrease client protein expression. We now report the characterization of the novel novobiocin analogue, F-4, which demonstrates improved cytotoxicity in prostate cancer cell lines compared to the N-terminal inhibitor, 17-AAG. LNCaP and PC-3 cells were treated with 17-AAG or F-4 in anti-proliferative, apoptosis, cell cycle and cytotoxicity assays. Western blot and prostate specific antigen (PSA) ELISAs were used to determine client protein degradation, induction of Hsp90 and to assess the functional status of the androgen receptor (AR) in response to F-4 treatment. Surface plasmon resonance (SPR) was also used to determine the binding properties of F-4 to Hsp90. F-4 demonstrated improved potency and efficacy compared to novobiocin in anti-proliferative assays and decreased expression of client proteins. PSA secretion was inhibited in a dose-dependent manner that paralleled a decrease in AR expression. The binding of F-4 to Hsp90 was determined to be saturable with a binding affinity (K(d)) of 100 microM. In addition, superior efficacy was demonstrated by F-4 compared to 17-AAG in experiments measuring cytotoxicity and apoptosis. These data reveal distinct modes of action for N-terminal and C-terminal Hsp90 inhibitors, which may offer unique therapeutic benefits for the treatment of prostate cancer.

Characterization of a novel novobiocin analogue as a putative C-terminal inhibitor of heat shock protein 90 in prostate cancer cells

PubMed Central

Shawna, B. Comer; George, A. Vielhauer; Craig, A. Manthe; Vamsee, K. Chaguturu; Kristen, Szabla; Robert, L. Matts; Alison, C. Donnelly; Brian, S. J. Blagg; Jeffrey, M. Holzbeierlein

2009-01-01

Purpose Hsp90 is important in the folding, maturation and stabilization of pro-tumorigenic client proteins and represents a viable drug target for the design of chemotherapies. Previously, we reported the development of novobiocin analogues designed to inhibit the C-terminal portion of Hsp90, which demonstrated the ability to decrease client protein expression. We now report the characterization of the novel novobiocin analogue, F-4, which demonstrates improved cytotoxicity in prostate cancer cell lines compared to the N-terminal inhibitor, 17-AAG. Materials and Methods LNCaP and PC-3 cells were treated with 17-AAG or F-4 in anti-proliferative, apoptosis, cell cycle and cytotoxicity assays. Western blot and prostate specific antigen (PSA) ELISAs were used to determine client protein degradation, induction of Hsp90 and to assess the functional status of the androgen receptor (AR) in response to F-4 treatment. Surface Plasmon Resonance (SPR) was also used to determine the binding properties of F-4 to Hsp90. Results F-4 demonstrated improved potency and efficacy compared to novobiocin in anti-proliferative assays and decreased expression of client proteins. PSA secretion was inhibited in a dose-dependent manner that paralleled a decrease in AR expression. The binding of F-4 to Hsp90 was determined to be saturable with a binding affinity (Kd) of 100 µM. In addition, superior efficacy was demonstrated by F-4 compared to 17-AAG in experiments measuring cytotoxicity and apoptosis Conclusions These data reveal distinct modes of action for N-terminal and C-terminal Hsp90 inhibitors, which may offer unique therapeutic benefits for the treatment of prostate cancer. PMID:19739131

Characterization of the Truncated Androgen Receptor Generated by Calpain-Dependent Proteolysis in Prostate Cancer

DTIC Science & Technology

2009-08-31

hierarchical network of transcription factors governs androgen receptor-dependent prostate cancer growth. Mol Cell, 2007. 27(3): p. 380 -92. 26. Takayama, K...TSS_upstream * 69570641 69571326 0.02 UGT2B15 -5 TSS_upstream 71417985 71418195 0.05 UNQ689 -796 TSS_upstream 29 83631386 83632082 0.02 MASA 60948

Membrane receptor-independent inhibitory effect of melatonin on androgen production in porcine theca cells.

PubMed

Wang, Heng; Pu, Yong; Luo, Lei; Li, Yunsheng; Zhang, Yunhai; Cao, Zubing

2018-06-01

Excessive secretion of androgens including androstenedione and testosterone in theca cells frequently causes female infertility in mammals. Melatonin is a potent inhibitor of androgen production in gonadal cells of several species in a membrane receptor-dependent manner. However, the function of melatonin in steroidogenesis of porcine theca cells remains unclear. Here we report that melatonin inhibits androgen biosynthesis independently of its membrane receptors in pigs. Using flow cytometry, immunofluorescence and RT-PCR we showed that the vast majority of cells isolated from the theca layer of antral follicles are indeed theca cells. Furthermore, we demonstrated that of the two of melatonin membrane receptors encoded in the porcine genome, theca cells exclusively express melatonin receptor 1B. Cell counting analysis indicated that different concentrations of melatonin did not alter the normal viability and proliferation of theca cells. Additionally, hormone radioimmunoassay and qPCR respectively showed that a high concentration of melatonin significantly repressed both androgen production and expression of steroidogenic genes involving StAR, CYP11A1, HSD3β and SET (P < 0.05), but did not impair progesterone production. Interestingly, these effects were not reversed by N-acetyl-2-benzyltryptamin, a melatonin membrane receptor antagonist. Overall, these results demonstrate that melatonin inhibits androgen production in porcine theca cells independently of its membrane receptor. Copyright © 2018 Elsevier Inc. All rights reserved.

CaM kinase kinase beta-mediated activation of the growth regulatory kinase AMPK is required for androgen-dependent migration of prostate cancer cells.

PubMed

Frigo, Daniel E; Howe, Matthew K; Wittmann, Bryan M; Brunner, Abigail M; Cushman, Ian; Wang, Qianben; Brown, Myles; Means, Anthony R; McDonnell, Donald P

2011-01-15

While patients with advanced prostate cancer initially respond favorably to androgen ablation therapy, most experience a relapse of the disease within 1-2 years. Although hormone-refractory disease is unresponsive to androgen-deprivation, androgen receptor (AR)-regulated signaling pathways remain active and are necessary for cancer progression. Thus, both AR itself and the processes downstream of the receptor remain viable targets for therapeutic intervention. Microarray analysis of multiple clinical cohorts showed that the serine/threonine kinase Ca2+/calmodulin-dependent protein kinase kinase β (CaMKKβ) is both highly expressed in the prostate and further elevated in prostate cancers. Using cellular models of prostate cancer, we have determined that androgens (a) directly increase the expression of a CaMKKβ splice variant and (b) increase functional CaMKKβ protein levels as determined by the phosphorylation of both CaMKI and AMP-activated protein kinase (AMPK), two of CaMKKβ's primary substrates. Importantly, inhibition of the CaMKKβ-AMPK, but not CaMKI, signaling axis in prostate cancer cells by pharmacological inhibitors or siRNA-mediated knockdown blocks androgen-mediated migration and invasion. Conversely, overexpression of CaMKKβ alone leads to both increased AMPK phosphorylation and cell migration. Given the key roles of CaMKKβ and AMPK in the biology of prostate cancer cells, we propose that these enzymes are potential therapeutic targets in prostate cancer. © 2010 AACR.

Androgen receptor-dependent and -independent mechanisms driving prostate cancer progression: Opportunities for therapeutic targeting from multiple angles

PubMed Central

Hoang, David T; Iczkowski, Kenneth A; Kilari, Deepak; See, William; Nevalainen, Marja T

2017-01-01

Despite aggressive treatment for localized cancer, prostate cancer (PC) remains a leading cause of cancer-related death for American men due to a subset of patients progressing to lethal and incurable metastatic castrate-resistant prostate cancer (CRPC). Organ-confined PC is treated by surgery or radiation with or without androgen deprivation therapy (ADT), while options for locally advanced and disseminated PC include radiation combined with ADT, or systemic treatments including chemotherapy. Progression to CRPC results from failure of ADT, which targets the androgen receptor (AR) signaling axis and inhibits AR-driven proliferation and survival pathways. The exact mechanisms underlying the transition from androgen-dependent PC to CRPC remain incompletely understood. Reactivation of AR has been shown to occur in CRPC despite depletion of circulating androgens by ADT. At the same time, the presence of AR-negative cell populations in CRPC has also been identified. While AR signaling has been proposed as the primary driver of CRPC, AR-independent signaling pathways may represent additional mechanisms underlying CRPC progression. Identification of new therapeutic strategies to target both AR-positive and AR-negative PC cell populations and, thereby, AR-driven as well as non-AR-driven PC cell growth and survival mechanisms would provide a two-pronged approach to eliminate CRPC cells with potential for synthetic lethality. In this review, we provide an overview of AR-dependent and AR-independent molecular mechanisms which drive CRPC, with special emphasis on the role of the Jak2-Stat5a/b signaling pathway in promoting castrate-resistant growth of PC through both AR-dependent and AR-independent mechanisms. PMID:27741508

A novel selective androgen receptor modulator (SARM) MK-4541 exerts anti-androgenic activity in the prostate cancer xenograft R-3327G and anabolic activity on skeletal muscle mass & function in castrated mice.

PubMed

Chisamore, Michael J; Gentile, Michael A; Dillon, Gregory Michael; Baran, Matthew; Gambone, Carlo; Riley, Sean; Schmidt, Azriel; Flores, Osvaldo; Wilkinson, Hilary; Alves, Stephen E

2016-10-01

The androgen receptor (AR) is a member of the nuclear hormone receptor super family of transcription factors. Androgens play an essential role in the development, growth, and maintenance of male sex organs, as well as the musculoskeletal and central nervous systems. Yet with advancing age, androgens can drive the onset of prostate cancer, the second leading cause of cancer death in males within the United States. Androgen deprivation therapy (ADT) by pharmacologic and/or surgical castration induces apoptosis of prostate cells and subsequent shrinkage of the prostate and prostate tumors. However, ADT is associated with significant musculoskeletal and behavioral adverse effects. The unique pharmacological activity of selective androgen receptor modulator (SARM) MK-4541 recently has been reported as an AR antagonist with 5α-reductase inhibitor function. The molecule inhibits proliferation and induces apoptosis in AR positive, androgen dependent prostate cancer cells. Importantly, MK-4541 inhibited androgen-dependent prostate growth in male rats yet maintained lean body mass and bone formation following ovariectomy in female rats. In the present study, we evaluated the effects of SARM MK-4541 in the androgen-dependent Dunning R3327-G prostate carcinoma xenograft mouse model as well as on skeletal muscle mass and function, and AR-regulated behavior in mice. MK-4541 significantly inhibited the growth of R3327-G prostate tumors, exhibited anti-androgen effects on the seminal vesicles, reduced plasma testosterone concentrations in intact males, and inhibited Ki67 expression. MK-4541 treated xenografts appeared similar to xenografts in castrated mice. Importantly, we demonstrate that MK-4541 exhibited anabolic activity in androgen deficient conditions, increasing lean body mass and muscle function in adult castrated mice. Moreover, MK-4541 treatment restored general activity levels in castrated mice. Thus, MK-4541 exhibits an optimum profile as an adjuvant therapy to ADT which may provide potent anti-androgenic activity at the prostate yet protective activity on skeletal muscle and behavior in patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of tumor markers in prostate cancer and comparison of sensitivity between real time and nested PCR.

PubMed

Matsuoka, Takayuki; Shigemura, Katsumi; Yamamichi, Fukashi; Fujisawa, Masato; Kawabata, Masato; Shirakawa, Toshiro

2012-06-27

The objective of this study is to investigate and compare the sensitivity in conventional PCR, quantitative real time PCR, nested PCR and western blots for detection of prostate cancer tumor markers using prostate cancer (PCa) cells. We performed conventional PCR, quantitative real time PCR, nested PCR, and western blots using 5 kinds of PCa cells. Prostate specific antigen (PSA), prostate specific membrane antigen (PSMA), and androgen receptor (AR) were compared for their detection sensitivity by real time PCR and nested PCR. In real time PCR, there was a significant correlation between cell number and the RNA concentration obtained (R(2)=0.9944) for PSA, PSMA, and AR. We found it possible to detect these markers from a single LNCaP cell in both real time and nested PCR. By comparison, nested PCR reached a linear curve in fewer PCR cycles than real time PCR, suggesting that nested PCR may offer PCR results more quickly than real time PCR. In conclusion, nested PCR may offer tumor maker detection in PCa cells more quickly (with fewer PCR cycles) with the same high sensitivity as real time PCR. Further study is necessary to establish and evaluate the best tool for PCa tumor marker detection.

Estrogen effects of Daldinia concentrica and Psathyrella efflorescens extracts in vitro.

PubMed

Benie, Tanon; Kouakou, Koffi; Thieulant, Marie-Lise

2008-02-28

Daldinia concentrica and Psathyrella efflorescens are two fungi used in African traditional medicine. In the present study, their extracts were evaluated for their steroid activities in estrogen- or androgen-dependent cell lines using as endpoints steroid-dependent transcriptional activity and cell proliferation. Treatment of human breast cancer MCF-7 cells with 15 or 30 microg/ml of Daldinia concentrica or Psathyrellaefflorescens extracts in the absence of 17beta-estradiol (E2) significantly increased the transcriptional activity of an estrogen receptor (ER)-dependent reporter gene, in the same range as E2. Similar data were obtained in gonadotrope cell line alpha-T3-1. All the effects were prevented by the pure estrogen antagonist, ICI 182,780. In the absence of steroid addition, the two extracts induced cell proliferation of ER-dependent MCF-7 and Ishikawa Var-I cell lines by approximately 100% of the E2 response. Combination treatments with E2 showed no competitive or additive effects in the two latter cell lines. Interestingly, the extracts had no androgen-like response in androgen receptor (AR)-positive and ER-negative MDA-MB231 cells, suggesting that fungi effects are estrogen specific and extracts are not toxic at used concentrations. Results provided evidence that Daldinia concentrica or Psathyrellaefflorescens extracts induce estrogen-like effects in ER-positive cell lines, which could be responsible of the effects observed in vivo.

Androgen Receptor-Mediated Growth Suppression of HPr-1AR and PC3-Lenti-AR Prostate Epithelial Cells

PubMed Central

Bolton, Eric C.

2015-01-01

The androgen receptor (AR) mediates the developmental, physiologic, and pathologic effects of androgens including 5α-dihydrotestosterone (DHT). However, the mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells are not well understood, though they are central to prostate development, homeostasis, and neoplasia. Here, we identify androgen-responsive genes that restrain cell cycle progression and proliferation of human prostate epithelial cell lines (HPr-1AR and PC3-Lenti-AR), and we investigate the mechanisms through which AR regulates their expression. DHT inhibited proliferation of HPr-1AR and PC3-Lenti-AR, and cell cycle analysis revealed a prolonged G1 interval. In the cell cycle, the G1/S-phase transition is initiated by the activity of cyclin D and cyclin-dependent kinase (CDK) complexes, which relieve growth suppression. In HPr-1AR, cyclin D1/2 and CDK4/6 mRNAs were androgen-repressed, whereas CDK inhibitor, CDKN1A, mRNA was androgen-induced. The regulation of these transcripts was AR-dependent, and involved multiple mechanisms. Similar AR-mediated down-regulation of CDK4/6 mRNAs and up-regulation of CDKN1A mRNA occurred in PC3-Lenti-AR. Further, CDK4/6 overexpression suppressed DHT-inhibited cell cycle progression and proliferation of HPr-1AR and PC3-Lenti-AR, whereas CDKN1A overexpression induced cell cycle arrest. We therefore propose that AR-mediated growth suppression of HPr-1AR involves cyclin D1 mRNA decay, transcriptional repression of cyclin D2 and CDK4/6, and transcriptional activation of CDKN1A, which serve to decrease CDK4/6 activity. AR-mediated inhibition of PC3-Lenti-AR proliferation occurs through a similar mechanism, albeit without down-regulation of cyclin D. Our findings provide insight into AR-mediated regulation of prostate epithelial cell proliferation. PMID:26372468

Intervention of Prostate Cancer by a Flavonoid Antioxidant Silymarin

DTIC Science & Technology

2001-04-01

effect of silymarin on PCA tumor growth in nude mice. Treatment of LNCaP and DUl45 human prostate carcinoma cells with silibinin (the pure form of...dimerization. These inhibitory effects of silibinin also corroborate with its inhibitory effect on both cellular and released expression of TGFalpha in...these two cell lines. In cytoplasmic signaling, silibinin showed strong decrease in ERKl/2 phosphorylation in both LNCaP and DUl45 cells and inhibition in

EXPOSURE TO DIETHYL HEXYL PHTHALATE (DEHP) DELAYS PUBERTY AND REDUCES ANDROGEN-DEPENDENT TISSUE WEIGHTS IN LONG EVANS HOODED AND SPRAGUE DAWLEY MALE RATS

EPA Science Inventory

DEHP is a plasticizer that alters sexual differentiation in the male rat by reducing fetal Leydig cell testosterone synthesis and insl3 mRNA levels. When exposure includes the pubertal stage of life, DEHP and other phthalates delay puberty and reduce androgen-dependent tissue wei...

Efficacious delivery of protein drugs to prostate cancer cells by PSMA-targeted pH-responsive chimaeric polymersomes.

PubMed

Li, Xiang; Yang, Weijing; Zou, Yan; Meng, Fenghua; Deng, Chao; Zhong, Zhiyuan

2015-12-28

Protein drugs as one of the most potent biotherapeutics have a tremendous potential in cancer therapy. Their application is, nevertheless, restricted by absence of efficacious, biocompatible, and cancer-targeting nanosystems. In this paper, we report that 2-[3-[5-amino-1-carboxypentyl]-ureido]-pentanedioic acid (Acupa)-decorated pH-responsive chimaeric polymersomes (Acupa-CPs) efficiently deliver therapeutic proteins into prostate cancer cells. Acupa-CPs had a unimodal distribution with average sizes ranging from 157-175 nm depending on amounts of Acupa. They displayed highly efficient loading of both model proteins, bovine serum albumin (BSA) and cytochrome C (CC), affording high protein loading contents of 9.1-24.5 wt.%. The in vitro release results showed that protein release was markedly accelerated at mildly acidic pH due to the hydrolysis of acetal bonds in the vesicular membrane. CLSM and MTT studies demonstrated that CC-loaded Acupa10-CPs mediated efficient delivery of protein drugs into PSMA positive LNCaP cells leading to pronounced antitumor effect, in contrast to their non-targeting counterparts and free CC. Remarkably, granzyme B (GrB)-loaded Acupa10-CPs caused effective apoptosis of LNCaP cells with a low half-maximal inhibitory concentration (IC50) of 1.6 nM. Flow cytometry and CLSM studies using MitoCapture™ revealed obvious depletion of mitochondria membrane potential in LNCaP cells treated with GrB-loaded Acupa10-CPs. The preliminary in vivo experiments showed that Acupa-CPs had a long circulation time with an elimination phase half-life of 3.3h in nude mice. PSMA-targeted, pH-responsive, and chimaeric polymersomes have appeared as efficient protein nanocarriers for targeted prostate cancer therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

[Role of CXCL16/CXCR6 axis in the metastasis of human prostate cancer].

PubMed

Zhou, Wen-hui; Hu, Wei-dong; Wu, Zhou-qing; Zheng, Xin-min; Wang, Bi-cheng

2010-04-13

To explore the roles of chemokine CXCL16 and its receptor CXCR6 in the directional invasion of human prostate cancer (PCa). The expression of CXCL16/CXCR6 in PCa samples and osseous tissues was determined by immunohistochemistry. The expression of CXCR6 in PC3 and LNCap cells was determined by reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry. Then the effects of CXCL16 upon the migration and invasion of human PC3 and LNCap cells were examined by Matrigel invasion assay. The expression of CXCR6 protein was detected in all clinical PCa samples. But no CXCL16 protein was detected. Positive CXCL16 expression was observed in human osseous tissues. Both PC3 and LNCap cells expressed CXCR6 mRNA (0.38+/-0.054 vs 0.41+/-0.019 respectively) and protein. In addition, CXCL16 could promote the in vitro migration and invasion of PC3 and LNCap cell lines (invading cells 211.50+/-5.60 vs 89.25+/-3.31 respectively). Such a promoting effect of CXCL16 could not be blocked influenced by antiCXCL12 or antiCXCR4. CXCL16/CXCR6 axis may be another independent chemokine factor playing a significant role in the metastasis of prostate cancer.

Bioenergetic and Antiapoptotic Properties of Mitochondria from Cultured Human Prostate Cancer Cell Lines PC-3, DU145 and LNCaP

PubMed Central

Panov, Alexander; Orynbayeva, Zulfiya

2013-01-01

The purpose of this work was to reveal the metabolic features of mitochondria that might be essential for inhibition of apoptotic potential in prostate cancer cells. We studied mitochondria isolated from normal prostate epithelial cells (PrEC), metastatic prostate cancer cell lines LNCaP, PC-3, DU145; and non-prostate cancer cells - human fibrosarcoma HT1080 cells; and normal human lymphoblastoid cells. PrEC cells contained 2 to 4 times less mitochondria per gram of cells than the three PC cell lines. Respiratory activities of PrEC cell mitochondria were 5-20-fold lower than PC mitochondria, depending on substrates and the metabolic state, due to lower content and lower activity of the respiratory enzyme complexes. Mitochondria from the three metastatic prostate cancer cell lines revealed several features that are distinctive only to these cells: low affinity of Complex I for NADH, 20-30 mV higher electrical membrane potential (ΔΨ). Unprotected with cyclosporine A (CsA) the PC-3 mitochondria required 4 times more Ca2+ to open the permeability transition pore (mPTP) when compared with the PrEC mitochondria, and they did not undergo swelling even in the presence of alamethicin, a large pore forming antibiotic. In the presence of CsA, the PC-3 mitochondria did not open spontaneously the mPTP. We conclude that the low apoptotic potential of the metastatic PC cells may arise from inhibition of the Ca2+-dependent permeability transition due to a very high ΔΨ and higher capacity to sequester Ca2+. We suggest that due to the high ΔΨ, mitochondrial metabolism of the metastatic prostate cancer cells is predominantly based on utilization of glutamate and glutamine, which may promote development of cachexia. PMID:23951286

Androgens: basic biology and clinical implication.

PubMed

Orwoll, E S

2001-10-01

Although androgens have been considered essential modulators of bone biology in men, recent studies have indicated that estrogen may have an important, if not dominant, role. Nevertheless, there is strong evidence that androgens have independent skeletal actions. Nonaromatizable androgens influence a variety of aspects of bone cell biology and are capable of modulating bone remodeling and bone mass. It appears that androgens are particularly important in the control of periosteal bone formation, an effect that might underlie the gender difference in bone size. Alterations in androgen receptor function affect bone metabolism, and new information suggests that androgens modulate receptor homeostasis. The clinical implications of androgen effects, and how they interact with those of estrogens, are somewhat unclear. It is likely that overall bone homeostasis and gender differences depend on a combination of androgenic and estrogenic actions. Androgens may well provide advantages in the prevention and therapy of metabolic bone disorders in both men and women.

Erratum: Epigenetic silencing of miR-34a in human prostate cancer cells and tumor tissue specimens can be reversed by BR-DIM treatment.

PubMed

Kong, D; Heath, E; Chen, W; Cher, M; Powell, I; Heilbrun, L; Li, Y; Ali, S; Sethi, S; Hassan, O; Hwang, C; Gupta, N; Chitale, D; Sakr, Wa; Menon, M; Sarkar, Fh

2013-01-01

Androgen Receptor (AR) signaling is critically important during the development and progression of prostate cancer (PCa). The AR signaling is also important in the development of castrate resistant prostate cancer (CRPC) where AR is functional even after androgen deprivation therapy (ADT); however, little is known regarding the transcriptional and functional regulation of AR in PCa. Moreover, treatment options for primary PCa for preventing the occurrence of CRPC is limited; therefore, novel strategy for direct inactivation of AR is urgently needed. In this study, we found loss of miR-34a, which targets AR, in PCa tissue specimens, especially in patients with higher Gleason grade tumors, consistent with increased expression of AR. Forced over-expression of miR-34a in PCa cell lines led to decreased expression of AR and prostate specific antigen (PSA) as well as the expression of Notch-1, another important target of miR-34a. Most importantly, BR-DIM intervention in PCa patients prior to radical prostatectomy showed reexpression of miR-34a, which was consistent with decreased expression of AR, PSA and Notch-1 in PCa tissue specimens. Moreover, BR-DIM intervention led to nuclear exclusion both in PCa cell lines and in tumor tissues. PCa cells treated with BR-DIM and 5-aza-dC resulted in the demethylation of miR-34a promoter concomitant with inhibition of AR and PSA expression in LNCaP and C4-2B cells. These results suggest, for the first time, epigenetic silencing of miR-34a in PCa, which could be reversed by BR-DIM treatment and, thus BR-DIM could be useful for the inactivation of AR in the treatment of PCa.[This corrects the article on p. 14 in vol. 4.].

Epigenetics-related genes in prostate cancer: expression profile in prostate cancer tissues, androgen-sensitive and -insensitive cell lines.

PubMed

Shaikhibrahim, Zaki; Lindstrot, Andreas; Ochsenfahrt, Jacqueline; Fuchs, Kerstin; Wernert, Nicolas

2013-01-01

Epigenetic changes have been suggested to drive prostate cancer (PCa) development and progression. Therefore, in this study, we aimed to identify novel epigenetics-related genes in PCa tissues, and to examine their expression in metastatic PCa cell lines. We analyzed the expression of epigenetics-related genes via a clustering analysis based on gene function in moderately and poorly differentiated PCa glands compared to normal glands of the peripheral zone (prostate proper) from PCa patients using Whole Human Genome Oligo Microarrays. Our analysis identified 12 epigenetics-related genes with a more than 2-fold increase or decrease in expression and a p-value <0.01. In modera-tely differentiated tumors compared to normal glands of the peripheral zone, we found the genes, TDRD1, IGF2, DICER1, ADARB1, HILS1, GLMN and TRIM27, to be upregulated, whereas TNRC6A and DGCR8 were found to be downregulated. In poorly differentiated tumors, we found TDRD1, ADARB and RBM3 to be upregulated, whereas DGCR8, PIWIL2 and BC069781 were downregulated. Our analysis of the expression level for each gene in the metastatic androgen-sensitive VCaP and LNCaP, and -insensitive PC3 and DU-145 PCa cell lines revealed differences in expression among the cell lines which may reflect the different biological properties of each cell line, and the potential role of each gene at different metastatic sites. The novel epigenetics-related genes that we identified in primary PCa tissues may provide further insight into the role that epigenetic changes play in PCa. Moreover, some of the genes that we identified may play important roles in primary PCa and metastasis, in primary PCa only, or in metastasis only. Follow-up studies are required to investigate the functional role and the role that the expression of these genes play in the outcome and progression of PCa using tissue microarrays.

Intracrine Androgens Enhance Decidualization and Modulate Expression of Human Endometrial Receptivity Genes

PubMed Central

Gibson, Douglas A.; Simitsidellis, Ioannis; Cousins, Fiona L.; Critchley, Hilary O. D.; Saunders, Philippa T. K.

2016-01-01

The endometrium is a complex, steroid-dependent tissue that undergoes dynamic cyclical remodelling. Transformation of stromal fibroblasts (ESC) into specialised secretory cells (decidualization) is fundamental to the establishment of a receptive endometrial microenvironment which can support and maintain pregnancy. Androgen receptors (AR) are present in ESC; in other tissues local metabolism of ovarian and adrenal-derived androgens regulate AR-dependent gene expression. We hypothesised that altered expression/activity of androgen biosynthetic enzymes would regulate tissue availability of bioactive androgens and the process of decidualization. Primary human ESC were treated in vitro for 1–8 days with progesterone and cAMP (decidualized) in the presence or absence of the AR antagonist flutamide. Time and treatment-dependent changes in genes essential for a) intra-tissue biosynthesis of androgens (5α-reductase/SRD5A1, aldo-keto reductase family 1 member C3/AKR1C3), b) establishment of endometrial decidualization (IGFBP1, prolactin) and c) endometrial receptivity (SPP1, MAOA, EDNRB) were measured. Decidualization of ESC resulted in significant time-dependent changes in expression of AKR1C3 and SRD5A1 and secretion of T/DHT. Addition of flutamide significantly reduced secretion of IGFBP1 and prolactin and altered the expression of endometrial receptivity markers. Intracrine biosynthesis of endometrial androgens during decidualization may play a key role in endometrial receptivity and offer a novel target for fertility treatment. PMID:26817618

Intracrine Androgens Enhance Decidualization and Modulate Expression of Human Endometrial Receptivity Genes.

PubMed

Gibson, Douglas A; Simitsidellis, Ioannis; Cousins, Fiona L; Critchley, Hilary O D; Saunders, Philippa T K

2016-01-28

The endometrium is a complex, steroid-dependent tissue that undergoes dynamic cyclical remodelling. Transformation of stromal fibroblasts (ESC) into specialised secretory cells (decidualization) is fundamental to the establishment of a receptive endometrial microenvironment which can support and maintain pregnancy. Androgen receptors (AR) are present in ESC; in other tissues local metabolism of ovarian and adrenal-derived androgens regulate AR-dependent gene expression. We hypothesised that altered expression/activity of androgen biosynthetic enzymes would regulate tissue availability of bioactive androgens and the process of decidualization. Primary human ESC were treated in vitro for 1-8 days with progesterone and cAMP (decidualized) in the presence or absence of the AR antagonist flutamide. Time and treatment-dependent changes in genes essential for a) intra-tissue biosynthesis of androgens (5α-reductase/SRD5A1, aldo-keto reductase family 1 member C3/AKR1C3), b) establishment of endometrial decidualization (IGFBP1, prolactin) and c) endometrial receptivity (SPP1, MAOA, EDNRB) were measured. Decidualization of ESC resulted in significant time-dependent changes in expression of AKR1C3 and SRD5A1 and secretion of T/DHT. Addition of flutamide significantly reduced secretion of IGFBP1 and prolactin and altered the expression of endometrial receptivity markers. Intracrine biosynthesis of endometrial androgens during decidualization may play a key role in endometrial receptivity and offer a novel target for fertility treatment.

Tumor suppressor BRCA1 is expressed in prostate cancer and controls IGF-I receptor (IGF-IR) gene transcription in an androgen receptor-dependent manner

PubMed Central

Schayek, Hagit; Haugk, Kathy; Sun, Shihua; True, Lawrence D.; Plymate, Stephen R.; Werner, Haim

2010-01-01

Purpose The insulin-like growth factor (IGF) system plays an important role in prostate cancer. The BRCA1 gene encodes a transcription factor with tumor suppressor activity. The involvement of BRCA1 in prostate cancer, however, has not yet been elucidated. The purpose of the present study was to examine the functional correlations between BRCA1 and the IGF system in prostate cancer. Experimental Design An immunohistochemical analysis of BRCA1 was performed on Tissue Microarrays comprising 203 primary prostate cancer specimens. In addition, BRCA1 levels were measured in prostate cancer xenografts and in cell lines representing early stages of the disease (P69 cells) and advanced stages (M12 cells). The ability of BRCA1 to regulate IGF-IR expression was studied by coexpression experiments using a BRCA1 expression vector along with an IGF-IR promoter-luciferase reporter. Results We found significantly elevated BRCA1 levels in prostate cancer in comparison to histologically normal prostate tissue (p < 0.001). In addition, an inverse correlation between BRCA1 and IGF-IR levels was observed in the AR-negative P69 and M12 prostate cancer-derived cell lines. Coexpression experiments in M12 cells revealed that BRCA1 was able to suppress IGF-IR promoter activity and endogenous IGF-IR levels. On the other hand, BRCA1 enhanced IGF-IR levels in LnCaP C4-2 cells expressing an endogenous AR. Conclusions We provide evidence that BRCA1 differentially regulates IGF-IR expression in AR positive and negative prostate cancer cells. The mechanism of action of BRCA1 involves modulation of IGF-IR gene transcription. In addition, immunohistochemical data is consistent with a potential survival role of BRCA1 in prostate cancer. PMID:19223505

The vitamin C:vitamin K3 system - enhancers and inhibitors of the anticancer effect.

PubMed

Lamson, Davis W; Gu, Yu-Huan; Plaza, Steven M; Brignall, Matthew S; Brinton, Cathy A; Sadlon, Angela E

2010-12-01

The oxidizing anticancer system of vitamin C and vitamin K₃ (VC:VK₃, producing hydrogen peroxide via superoxide) was combined individually with melatonin, curcumin, quercetin, or cholecalciferol (VD₃) to determine interactions. Substrates were LNCaP and PC-3 prostate cancer cell lines. Three of the tested antioxidants displayed differences in cell line cytotoxicity. Melatonin combined with VC:VK₃ quenched the oxidizing effect, while VC:VK₃ applied 24 hours after melatonin showed no quenching. With increasing curcumin concentrations, an apparent combined effect of VC:VK₃ and curcumin occurred in LNCaP cells, but not PC-3 cells. Quercetin alone was cytotoxic on both cell lines, but demonstrated an additional 50-percent cytotoxicity on PC-3 cells when combined with VC:VK₃. VD₃ was effective against both cell lines, with more effect on PC-3. This effect was negated on LNCaP cells with the addition of VC:VK₃. In conclusion, a natural antioxidant can enhance or decrease the cytotoxicity of an oxidizing anticancer system in vitro, but generalizations about antioxidants cannot be made.

Modulation of Induced Cytotoxicity of Doxorubicin by Using Apoferritin and Liposomal Cages

PubMed Central

Gumulec, Jaromir; Fojtu, Michaela; Raudenska, Martina; Sztalmachova, Marketa; Skotakova, Anna; Vlachova, Jana; Skalickova, Sylvie; Nejdl, Lukas; Kopel, Pavel; Knopfova, Lucia; Adam, Vojtech; Kizek, Rene; Stiborova, Marie; Babula, Petr; Masarik, Michal

2014-01-01

Doxorubicin is an effective chemotherapeutic drug, however, its toxicity is a significant limitation in therapy. Encapsulation of doxorubicin inside liposomes or ferritin cages decreases cardiotoxicity while maintaining anticancer potency. We synthesized novel apoferritin- and liposome-encapsulated forms of doxorubicin (“Apodox” and “lip-8-dox”) and compared its toxicity with doxorubicin and Myocet on prostate cell lines. Three different prostatic cell lines PNT1A, 22Rv1, and LNCaP were chosen. The toxicity of the modified doxorubicin forms was compared to conventional doxorubicin using the MTT assay, real-time cell impedance-based cell growth method (RTCA), and flow cytometry. The efficiency of doxorubicin entrapment was 56% in apoferritin cages and 42% in the liposome carrier. The accuracy of the RTCA system was verified by flow-cytometric analysis of cell viability. The doxorubicin half maximal inhibition concentrations (IC50) were determined as 170.5, 234.0, and 169.0 nM for PNT1A, 22Rv1, and LNCaP, respectively by RTCA. Lip8-dox is less toxic on the non-tumor cell line PNT1A compared to doxorubicin, while still maintaining the toxicity to tumorous cell lines similar to doxorubicin or epirubicin (IC50 = 2076.7 nM for PNT1A vs. 935.3 and 729.0 nM for 22Rv1 and LNCaP). Apodox IC50 was determined as follows: 603.1, 1344.2, and 931.2 nM for PNT1A, 22Rv1, and LNCaP. PMID:25514405

Regulating Prostate Cancer Sensitivity to Chemotherapy through Translational Control of CCAAT Enhancer Binding Proteins

DTIC Science & Technology

2015-08-01

ratio in LNCaP and PC3 cells and suppression of CEBPB sensitized these cells to bortezomib in vitro. PC3 xenografts deficient in CEBPB showed...resistant growth of PCa tumors in a mouse xenograft model. shNTV or shCEBPB LNCaP cells were subcutaneously engrafted into male NSG mice and when tumors...was monitored weekly by caliper measurement for 8-weeks (Fig. 3B). We observed significant suppression of CRPC growth in xenografts expressing shC

Mathematical modeling of prostate cancer progression in response to androgen ablation therapy.

PubMed

Jain, Harsh Vardhan; Clinton, Steven K; Bhinder, Arvinder; Friedman, Avner

2011-12-06

Prostate cancer progression depends in part on the complex interactions between testosterone, its active metabolite DHT, and androgen receptors. In a metastatic setting, the first line of treatment is the elimination of testosterone. However, such interventions are not curative because cancer cells evolve via multiple mechanisms to a castrate-resistant state, allowing progression to a lethal outcome. It is hypothesized that administration of antiandrogen therapy in an intermittent, as opposed to continuous, manner may bestow improved disease control with fewer treatment-related toxicities. The present study develops a biochemically motivated mathematical model of antiandrogen therapy that can be tested prospectively as a predictive tool. The model includes "personalized" parameters, which address the heterogeneity in the predicted course of the disease under various androgen-deprivation schedules. Model simulations are able to capture a variety of clinically observed outcomes for "average" patient data under different intermittent schedules. The model predicts that in the absence of a competitive advantage of androgen-dependent cancer cells over castration-resistant cancer cells, intermittent scheduling can lead to more rapid treatment failure as compared to continuous treatment. However, increasing a competitive advantage for hormone-sensitive cells swings the balance in favor of intermittent scheduling, delaying the acquisition of genetic or epigenetic alterations empowering androgen resistance. Given the near universal prevalence of antiandrogen treatment failure in the absence of competing mortality, such modeling has the potential of developing into a useful tool for incorporation into clinical research trials and ultimately as a prognostic tool for individual patients.

Opposing effects of estradiol- and testosterone-membrane binding sites on T47D breast cancer cell apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kampa, Marilena; Nifli, Artemissia-Phoebe; Charalampopoulos, Ioannis

Classical steroid mode of action involves binding to intracellular receptors, the later acting as ligand-activated nuclear transcription factors. Recently, membrane sites for different steroids have been also identified, mediating rapid, non-genomic, steroid actions. Membrane sites for estrogen and androgen have been found in a number of different cell types, bearing or not classical intracellular receptors. In the present study, with the use of radioligand binding, flow cytometry and confocal laser microscopy, we report that T47D human breast cancer cells express specific and saturable membrane receptors for both estrogen (K {sub D} 4.06 {+-} 3.31 nM) and androgen (K {sub D}more » 7.64 {+-} 3.15 nM). Upon activation with BSA-conjugated, non-permeable ligands (E{sub 2}-BSA and testosterone-BSA), membrane estrogen receptors protect cells from serum-deprivation-induced apoptosis, while androgen receptors induce apoptosis in serum-supplemented T47D cells. In addition, co-incubation of cells with a fixed concentration of one steroid and varying concentrations of the other reversed the abovementioned effect (apoptosis for androgen, and anti-apoptosis for E{sub 2}), suggesting that the fate of the cell depends on the relative concentration of either steroid in the culture medium. We also report the identification of membrane receptors for E{sub 2} and androgen in biopsy slides from breast cancer patients. Both sites are expressed, with the staining for membrane E{sub 2} being strongly present in ER-negative, less differentiated, more aggressive tumors. These findings suggest that aromatase inhibitors may exert their beneficial effects on breast cancer by also propagating the metabolism of local steroids towards androgen, inducing thus cell apoptosis through membrane androgen receptor activation.« less

Genome-Wide Analysis of Androgen Receptor Targets Reveals COUP-TF1 as a Novel Player in Human Prostate Cancer

PubMed Central

Perets, Ruth; Kaplan, Tommy; Stein, Ilan; Hidas, Guy; Tayeb, Shay; Avraham, Eti; Ben-Neriah, Yinon; Simon, Itamar; Pikarsky, Eli

2012-01-01

Androgen activity plays a key role in prostate cancer progression. Androgen receptor (AR) is the main mediator of androgen activity in the prostate, through its ability to act as a transcription mediator. Here we performed a genome-wide analysis of human AR binding to promoters in the presence of an agonist or antagonist in an androgen dependent prostate cancer cell line. Many of the AR bound promoters are bound in all examined conditions while others are bound only in the presence of an agonist or antagonist. Several motifs are enriched in AR bound promoters, including the AR Response Element (ARE) half-site and recognition elements for the transcription factors OCT1 and SOX9. This suggests that these 3 factors could define a module of co-operating transcription factors in the prostate. Interestingly, AR bound promoters are preferentially located in AT rich genomic regions. Analysis of mRNA expression identified chicken ovalbumin upstream promoter-transcription factor 1 (COUP-TF1) as a direct AR target gene that is downregulated upon binding by the agonist liganded AR. COUP-TF1 immunostaining revealed nucleolar localization of COUP-TF1 in epithelium of human androgen dependent prostate cancer, but not in adjacent benign prostate epithelium. Stromal cells both in human and mouse prostate show nuclear COUP-TF1 staining. We further show that there is an inverse correlation between COUP-TF1 expression in prostate stromal cells and the rising levels of androgen with advancing puberty. This study extends the pool of recognized putative AR targets and identifies a negatively regulated target of AR – COUP-TF1 – which could possibly play a role in human prostate cancer. PMID:23056316

Genome-wide analysis of androgen receptor targets reveals COUP-TF1 as a novel player in human prostate cancer.

PubMed

Perets, Ruth; Kaplan, Tommy; Stein, Ilan; Hidas, Guy; Tayeb, Shay; Avraham, Eti; Ben-Neriah, Yinon; Simon, Itamar; Pikarsky, Eli

2012-01-01

Androgen activity plays a key role in prostate cancer progression. Androgen receptor (AR) is the main mediator of androgen activity in the prostate, through its ability to act as a transcription mediator. Here we performed a genome-wide analysis of human AR binding to promoters in the presence of an agonist or antagonist in an androgen dependent prostate cancer cell line. Many of the AR bound promoters are bound in all examined conditions while others are bound only in the presence of an agonist or antagonist. Several motifs are enriched in AR bound promoters, including the AR Response Element (ARE) half-site and recognition elements for the transcription factors OCT1 and SOX9. This suggests that these 3 factors could define a module of co-operating transcription factors in the prostate. Interestingly, AR bound promoters are preferentially located in AT rich genomic regions. Analysis of mRNA expression identified chicken ovalbumin upstream promoter-transcription factor 1 (COUP-TF1) as a direct AR target gene that is downregulated upon binding by the agonist liganded AR. COUP-TF1 immunostaining revealed nucleolar localization of COUP-TF1 in epithelium of human androgen dependent prostate cancer, but not in adjacent benign prostate epithelium. Stromal cells both in human and mouse prostate show nuclear COUP-TF1 staining. We further show that there is an inverse correlation between COUP-TF1 expression in prostate stromal cells and the rising levels of androgen with advancing puberty. This study extends the pool of recognized putative AR targets and identifies a negatively regulated target of AR - COUP-TF1 - which could possibly play a role in human prostate cancer.

The metabolism of testosterone by dermal papilla cells cultured from human pubic and axillary hair follicles concurs with hair growth in 5 alpha-reductase deficiency.

PubMed

Hamada, K; Thornton, M J; Laing, I; Messenger, A G; Randall, V A

1996-05-01

Androgens regulate the growth of many human hair follicles, but only pubic, axillary, and scalp hair growth occur in men with 5 alpha-reductase deficiency. This suggests that 5 alpha-dihydrotestosterone is the active intracellular androgen in androgen-dependent follicles, except in the axilla and pubis. Since the dermal papilla plays a major regulatory role in hair follicles and may be the site of androgen action, we have investigated androgen metabolism in six primary lines of cultured dermal papilla cells from pubic and axillary hair follicles; previous studies have shown that beard cells take up and metabolize testosterone, retaining and secreting 5 alpha-dihydrotestosterone. After 24 h preincubation in serum-free Eagle's medium 199, 100-mm dishes of confluent cells were incubated for 2 h with 5 nM [1,2,6,7-3H]testosterone. Media were collected and the cells washed with phosphate-buffered saline and extracted with chloroform: methanol (2:1). After the addition of unlabeled and 14C-labeled marker steroids, the extracts were analyzed by a two-step thin-layer chromatography system; steroid identity was confirmed by recrystallization to a constant 3H/14C ratio. Beard and pubic dermal papilla cells were also incubated for 24 h, and the medium was analyzed at various times. The results from pubic and axillary primary cell lines were similar. In both cells and media the major steroid identified was testosterone, but significant amounts of androstenedione were present, indicating 17 beta-hydroxysteroid dehydrogenase activity; androstenedione was also identified within the cells, but a small amount of 5 alpha-dihydrotestosterone was only identified in one pubic cell line. Beard dermal papilla cells secreted large amounts of 5 alpha-dihydrotestosterone into the medium over 24 h in contrast to pubic cells, which produced only very small amounts. The pubic and axillary cell results contrasts with the observations of pronounced 5 alpha-dihydrotestosterone in beard cells and confirm that androgen metabolism in cultured dermal papilla cells reflects the parent follicle's ability to respond to androgen in the absence of 5 alpha-reductase type II in vivo. This supports our hypothesis that androgen acts on hair follicles via the dermal papilla and suggests that cultured dermal papilla cells may offer an important model system for studies of androgen action.

Anti-prostate cancer activity of a beta-carboline alkaloid enriched extract from Rauwolfia vomitoria.

PubMed

Bemis, D L; Capodice, J L; Gorroochurn, P; Katz, A E; Buttyan, R

2006-11-01

The tropical shrub, Rauwolfia vomitoria, is a medicinal plant used traditionally to treat a variety of ailments. A bioactive beta-carboline alkaloid, alstonine, present in this extract was previously shown to have anti-cancer activity against cancer cell lines. This study considers the potential anti-prostate cancer activity of this extract in vitro and in vivo. Rauwolfia vomitoria extract standardized for beta-carboline alkaloids was tested for ability to influence the growth and survival of the human LNCaP prostate cancer cell line. A WST-1 assay was used to measure cell growth, and cell cycle analyses were conducted with flow cytometry. Western blot detection of PARP cleavage and accumulation of cells containing sub-genomic DNA indicated induction of apoptosis. Pathway specific microarray analyses were utilized to identify the effect of Rauwolfia extract on the expression of 225 genes. Mice xenografted with LNCaP cells were treated with the extract or placebo control, and tumor growth was measured for 5 weeks. The effects of the extract on xenografted tumor cell proliferation and apoptosis were measured by in situ BrdU incorporation and TUNEL staining. Rauwolfia extract decreased in vitro cell growth in a dose-dependent manner (p<0.001) and induced the accumulation of G1 phase cells. PARP cleavage demonstrated that apoptosis was induced only at the highest concentration tested (500 microg/ml) which was confirmed by detection of cells containing sub-genomic DNA. The expression of genes associated with DNA damage signaling pathway was up-regulated by Rauwolfia treatment, including that of GADD153 and MDG. The expression of a few cell cycle genes (p21, cyclin D1 and E2F1) was also modulated. These alterations were confirmed by RT-PCR. Tumor volumes were decreased by 60%, 70% and 58% in the groups fed the 75, 37.5 or 7.5 mg/kg Rauwolfia, respectively (Kruskal-Wallis test, p<0.001). The Rauwolfia vomitoria extract significantly suppressed the growth and cell cycle progression of LNCaP cells, in vitro and in vivo.

Androgen receptor splice variants circumvent AR blockade by microtubule-targeting agents

PubMed Central

Zhang, Guanyi; Liu, Xichun; Li, Jianzhuo; Ledet, Elisa; Alvarez, Xavier; Qi, Yanfeng; Fu, Xueqi; Sartor, Oliver; Dong, Yan; Zhang, Haitao

2015-01-01

Docetaxel-based chemotherapy is established as a first-line treatment and standard of care for patients with metastatic castration-resistant prostate cancer. However, half of the patients do not respond to treatment and those do respond eventually become refractory. A better understanding of the resistance mechanisms to taxane chemotherapy is both urgent and clinical significant, as taxanes (docetaxel and cabazitaxel) are being used in various clinical settings. Sustained signaling through the androgen receptor (AR) has been established as a hallmark of CRPC. Recently, splicing variants of AR (AR-Vs) that lack the ligand-binding domain (LBD) have been identified. These variants are constitutively active and drive prostate cancer growth in a castration-resistant manner. In taxane-resistant cell lines, we found the expression of a major variant, AR-V7, was upregulated. Furthermore, ectopic expression of two clinically relevant AR-Vs (AR-V7 and ARV567es), but not the full-length AR (AR-FL), reduced the sensitivities to taxanes in LNCaP cells. Treatment with taxanes inhibited the transcriptional activity of AR-FL, but not those of AR-Vs. This could be explained, at least in part, due to the inability of taxanes to block the nuclear translocation of AR-Vs. Through a series of deletion constructs, the microtubule-binding activity was mapped to the LBD of AR. Finally, taxane-induced cytoplasm sequestration of AR-FL was alleviated when AR-Vs were present. These findings provide evidence that constitutively active AR-Vs maintain the AR signaling axis by evading the inhibitory effects of microtubule-targeting agents, suggesting that these AR-Vs play a role in resistance to taxane chemotherapy. PMID:26160840

Perfluoroalkylated substances (PFAS) affect neither estrogen and androgen receptor activity nor steroidogenesis in human cells in vitro.

PubMed

Behr, Anne-Cathrin; Lichtenstein, Dajana; Braeuning, Albert; Lampen, Alfonso; Buhrke, Thorsten

2018-07-01

The perfluoroalkylated substances (PFAS) perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are used for the fabrication of water- and dirt-repellent surfaces. The use of PFOS and PFOA was restricted due to their reprotoxic properties and their environmental persistence. Therefore, industry switches to alternative PFAS, however, in contrast to PFOA and PFOS only few toxicological data are available for their substitutes. The molecular mechanism(s) underlying reproductive toxicity of PFOA and PFOS are largely unknown. Here, the endocrine properties of PFOA, PFOS, and of six substitutes including perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), perfluorohexanoic acid (PFHxA), perfluorobutanoic acid (PFBA), ammonium perfluoro(2-methyl-3-oxahexanoate) (PMOH), and 3H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP) were examined in vitro by using human cell lines such as MCF-7, H295R, LNCaP and MDA-kb2. PFOA, PFOS and PMOH enhanced 17β-estradiol-stimulated estrogen receptor β activity, and PFOS, PMOH, PFHxA and PFBA enhanced dihydrotestosterone-stimulated androgen receptor activity. In the H295R steroidogenesis assay, PFOA and PFOS slightly enhanced estrone secretion, and progesterone secretion was marginally increased by PFOA. All these effects were only observed at concentrations above 10 μM, and none of the PFAS displayed any effect on any of the molecular endocrine endpoints at concentrations of 10 μM or below. Thus, as the blood serum concentrations of the different PFAS in the general Western population are in the range of 10 nM or below, the results suggest that PFAS might not exert endocrine effects in humans at exposure-relevant concentrations according to the molecular endpoints examined in this study. Copyright © 2018 Elsevier B.V. All rights reserved.

Utilizing Functionalized Nano-Paterned Surfaces as a clue to Cell Metastasis in Prostate and Breast Cancer

NASA Astrophysics Data System (ADS)

Matthews, James; Bastatas, Lyndon

2012-03-01

There is a direct relation between the survival of a patient diagnosed with prostate or breast cancer and the metastatic potential of the patient's cancer. It is therefore extremely important to prognose metastatic potentials. In this study we investigated whether the behaviors of cancer cells responding to our state of the art nano-patterns differ by the metastatic potential of the cancer cells. We have used lowly (LNCaP) and highly (CL-1) metastatic human prostate cancer cells and lowly (MCF-7) and highly (MB231) metastatic breast cancer cells. A surface functionalization study was then performed first on uniform gold and glass surfaces, then on gold nano-patterned surfaces made by nano-sphere lithography using nano-spheres in diameter of 200nm to 800nm. The gold surfaces were functionalized with fibronectin (FN) and confirmed through XPS analysis. The CL-1, MCF-7, and MB231 cells show similar proliferation on all surfaces regardless of the presence of FN, whereas LNCaP show a clear preference for FN coated surfaces. The proliferation of the LNCaP was reduced when grown on finer nano-scaffolds, but the more aggressive CL-1, MB231, and MCF-7 cells show an abnormal proliferation regardless of pattern size. The difference in adhesion is intrinsic and was verified through dual fluorescent imaging. Clear co-localization of actin-vinculin were found on CL-1, MCF-7, and MB231. However LNCaP cells showed the co-localization only on the tips of the cells. These results provide vital clues to the bio-mechanical differences between the cancer cells with different metastatic potential.

Antiproliferative mechanisms of the flavonoids 2,2'-dihydroxychalcone and fisetin in human prostate cancer cells.

PubMed

Haddad, Ahmed Q; Fleshner, Neil; Nelson, Colleen; Saour, Basil; Musquera, Mireia; Venkateswaran, Vasundara; Klotz, Laurence

2010-01-01

We have previously demonstrated the antiproliferative effect of two flavonoids-2,2'-dihydroxychalcone (DHC), a novel synthetic flavonoid, and fisetin, a naturally occurring flavonol-in prostate cancer cells. In this study, we further examine the mechanisms of these compounds on survival and proliferation pathways. DHC and fisetin (1-50 microM) caused a dose-dependent reduction in viability, a concomitant increase in apoptosis in PC3 cells at 72 h, and a decrease in clonogenic survival at 24 h treatment. DHC was considerably more potent than fisetin in these cytotoxicity assays. The mechanism of accelerated cellular senescence was not activated by either compound in PC3 or lymph node carcinoma of the prostate (LNCaP) cells. Gene expression alterations in PC3 and LNCaP cells treated with 15 muM DHC and 25 microM fisetin for 6 to 24 h were determined by oligonucleotide array. Amongst the most highly represented functional categories of genes altered by both compounds was the cell cycle category. In total, 100 cell cycle genes were altered by DHC and fisetin including 27 genes with key functions in G2/M phase that were downregulated by both compounds. Other functional categories altered included chromosome organization, apoptosis, and stress response. These results demonstrate the multiple mechanisms of antitumor activity of DHC and fisetin in prostate cancer cells in vitro.

A novel anticancer agent, decursin, induces G1 arrest and apoptosis in human prostate carcinoma cells.

PubMed

Yim, Dongsool; Singh, Rana P; Agarwal, Chapla; Lee, Sookyeon; Chi, Hyungjoon; Agarwal, Rajesh

2005-02-01

We isolated a coumarin compound decursin (C(19)H(20)O(5); molecular weight 328) from Korean angelica (Angelica gigas) root and characterized it by spectroscopy. Here, for the first time, we observed that decursin (25-100 micromol/L) treatment for 24 to 96 hours strongly inhibits growth and induces death in human prostate carcinoma DU145, PC-3, and LNCaP cells. Furthermore, we observed that decursinol [where (CH(3))(2)-C=CH-COO- side chain of decursin is substituted with -OH] has much lower effects compared with decursin, suggesting a possible structure-activity relationship. Decursin-induced growth inhibition was associated with a strong G(1) arrest (P < 0.001) in DU145 and LNCaP cells, and G(1), S as well as G(2)-M arrests depending upon doses and treatment times in PC-3 cells. Comparatively, decursin was nontoxic to human prostate epithelial PWR-1E cells and showed only moderate growth inhibition and G(1) arrest. Consistent with G(1) arrest in DU145 cells, decursin strongly increased protein levels of Cip1/p21 but showed a moderate increase in Kip1/p27 with a decrease in cyclin-dependent kinases (CDK); CDK2, CDK4, CDK6, and cyclin D1, and inhibited CDK2, CDK4, CDK6, cyclin D1, and cyclin E kinase activity, and increased binding of CDK inhibitor (CDKI) with CDK. Decursin-caused cell death was associated with an increase in apoptosis (P < 0.05-0.001) and cleaved caspase-9, caspase-3, and poly(ADP-ribose) polymerase; however, pretreatment with all-caspases inhibitor (z-VAD-fmk) only partially reversed decursin-induced apoptosis, suggesting the involvement of both caspase-dependent and caspase-independent pathways. These findings suggest the novel anticancer efficacy of decursin mediated via induction of cell cycle arrest and apoptosis selectively in human prostate carcinoma cells.

Intervention of Prostate Cancer by a Flavonoid Antioxidant Silymarin

DTIC Science & Technology

1999-10-01

receptor and cytoplasmic levels. Treatment of LNCaP and DU145 human prostate carcinoma cells with silibinin (the pure form of silymarin) resulted in... silibinin does not result in the inhibition of intrinsic tyrosine kinase activity of erbB 1 in both LNCaP and DU 145 cells. The observed inhibitory...suggest that more detailed mechanistic and tumor studies are needed to assess both preventive and interventive effects of silymarin (or silibinin ) against human rostate cancer.

Androgen Receptor (AR) in Cardiovascular Diseases

PubMed Central

Huang, Chiung-Kuei; Lee, Soo Ok; Chang, Eugene; Pang, Haiyan; Chang, Chawnshang

2016-01-01

Cardiovascular diseases (CVDs) are still the highest leading cause of death worldwide. Several risk factors have been linked to CVDs, including smoking, diabetes, hyperlipidemia, and gender among others. Sex hormones, especially the androgen and its receptor, androgen receptor (AR), have been linked to many diseases with a clear gender difference. Here, we summarize androgen/AR effects on CVDs, including hypertension, stroke, atherosclerosis, abdominal aortic aneurysm (AAA), myocardial hypertrophy, and heart failure, as well as metabolic syndrome/diabetes and their impacts on CVDs. Androgen/AR signaling exacerbates hypertension and anti-androgens may suppress hypertension. Androgen/AR signaling plays dual roles in strokes, depending on different kinds of factors, but generally males have a higher incidence of strokes than females. Androgen and AR differentially modulate atherosclerosis. Androgen deficiency causes elevated lipid accumulation to enhance atherosclerosis, but targeting AR in selective cells without altering serum androgen levels would suppress atherosclerosis progression. Androgen/AR signaling is crucial in AAA development and progression, and targeting androgen/AR profoundly restricts AAA progression. Men have increased cardiac hypertrophy as compared to age-matched women that may be due to androgens. Finally, androgen/AR plays important roles in contributing to obesity and insulin/leptin resistance to increase the metabolic syndrome. PMID:26769913

Androgen and AR contribute to breast cancer development and metastasis: an insight of mechanisms.

PubMed

Feng, J; Li, L; Zhang, N; Liu, J; Zhang, L; Gao, H; Wang, G; Li, Y; Zhang, Y; Li, X; Liu, D; Lu, J; Huang, B

2017-05-18

The role of androgen and androgen receptor (AR) in breast carcinogenesis has long been a disputed issue. This report provides a mechanistic insight into how androgen and AR contributes to invasion and metastasis of breast cancer. We find that dihydrotestosterone (DHT) is able to induce the epithelial-to-mesenchymal transition in breast cancer cells in an AR-dependent/estrogen receptor-independent manner. This process is dependent on the demethylation activity of lysine-specific demethylase 1A (LSD1) by epigenetically regulating the target genes E-cadherin and vimentin. In vivo, DHT promotes metastasis in a nude mouse model, and AR and LSD1 are indispensable in this process. We establish that higher expression of nucleus AR to cytoplasm AR associated with worse prognostic outcomes in breast cancer patient samples. This study maps an 'androgen-AR/LSD1-target genes' pathway in breast carcinogenesis, implicating the importance of hormonal balance in women, and the potential clinical significance of serum androgen and AR in prediction of breast cancer and selection of breast cancer therapy.

Effects of anti-cancer drug doxorubicin on endogenous biomarkers NAD(P)H, FAD and Trp in prostate cancer cells: a FLIM Study

NASA Astrophysics Data System (ADS)

Rehman Alam, Shagufta; Wallrabe, Horst; Svindrych, Zdenek; Christopher, Kathryn G.; Chandra, Dhyan; Periasamy, Ammasi

2017-02-01

Fluorescence Lifetime Imaging Microscopy (FLIM) can be used to identify changes in metabolic activity during cancer progression and upon anti-cancer drug treatment. Prostate cancer (PCa) is one of the leading cancers in men in the USA. This research focusses on understanding the lifetime changes of endogenous biomarkers: NAD(P)H, FAD and Trp in LNCaP cells upon treatment with doxorubicin using our 3-channel FLIM approach. The LNCaP cells were treated with doxorubicin for 24hr. Images using FLIM of LNCaP control and treated cells were acquired on Zeiss 780 multiphoton confocal microscope coupled with B and H TCSPC FLIM board. After FLIM data fitting and processing we observed increase in the mean fluorescence lifetime of Trp, NAD(P)H and FAD with doxorubicin treatment. Additionally, we saw reduction in the NAD(P)H/FAD redox ratio with doxorubicin treatment. Our results identify the changes in the lifetime of these endogenous biomarkers and in the cellular redox state as a metabolic response with doxorubicin treatment in prostate cancer cells.

Increased androgen levels in rats impair glucose-stimulated insulin secretion through disruption of pancreatic beta cell mitochondrial function.

PubMed

Wang, Hongdong; Wang, Xiaping; Zhu, Yunxia; Chen, Fang; Sun, Yujie; Han, Xiao

2015-11-01

Although insulin resistance is recognized to contribute to the reproductive and metabolic phenotypes of polycystic ovary syndrome (PCOS), pancreatic beta cell dysfunction plays an essential role in the progression from PCOS to the development of type 2 diabetes. However, the role of insulin secretory abnormalities in PCOS has received little attention. In addition, the precise changes in beta cells and the underlying mechanisms remain unclear. In this study, we therefore attempted to elucidate potential mechanisms involved in beta cell alterations in a rat model of PCOS. Glucose-induced insulin secretion was measured in islets isolated from DHT-treated and control rats. Oxygen consumption rate (OCR), ATP production, and mitochondrial copy number were assayed to evaluate mitochondrial function. Glucose-stimulated insulin secretion is significantly decreased in islets from DHT-treated rats. On the other hand, significant reductions are observed in the expression levels of several key genes involved in mitochondrial biogenesis and in mitochondrial OCR and ATP production in DHT-treated rat islets. Meanwhile, we found that androgens can directly impair beta cell function by inducing mitochondrial dysfunction in vitro in an androgen receptor dependent manner. For the first time, our study demonstrates that increased androgens in female rats can impair glucose-stimulated insulin secretion partly through disruption of pancreatic beta cell mitochondrial function. This work has significance for hyperandrogenic women with PCOS: excess activation of the androgen receptor by androgens may provoke beta cell dysfunction via mitochondrial dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cell-autonomous intracellular androgen receptor signaling drives the growth of human prostate cancer initiating cells.

PubMed

Vander Griend, Donald J; D'Antonio, Jason; Gurel, Bora; Antony, Lizamma; Demarzo, Angelo M; Isaacs, John T

2010-01-01

The lethality of prostate cancer is due to the continuous growth of cancer initiating cells (CICs) which are often stimulated by androgen receptor (AR) signaling. However, the underlying molecular mechanism(s) for such AR-mediated growth stimulation are not fully understood. Such mechanisms may involve cancer cell-dependent induction of tumor stromal cells to produce paracrine growth factors or could involve cancer cell autonomous autocrine and/or intracellular AR signaling pathways. We utilized clinical samples, animal models and a series of AR-positive human prostate cancer cell lines to evaluate AR-mediated growth stimulation of prostate CICs. The present studies document that stromal AR expression is not required for prostate cancer growth, since tumor stroma surrounding AR-positive human prostate cancer metastases (N = 127) are characteristically AR-negative. This lack of a requirement for AR expression in tumor stromal cells is also documented by the fact that human AR-positive prostate cancer cells grow equally well when xenografted in wild-type versus AR-null nude mice. AR-dependent growth stimulation was documented to involve secretion, extracellular binding, and signaling by autocrine growth factors. Orthotopic xenograft animal studies documented that the cellautonomous autocrine growth factors which stimulate prostate CIC growth are not the andromedins secreted by normal prostate stromal cells. Such cell autonomous and extracellular autocrine signaling is necessary but not sufficient for the optimal growth of prostate CICs based upon the response to anti-androgen plus/or minus preconditioned media. AR-induced growth stimulation of human prostate CICs requires AR-dependent intracellular pathways. The identification of such AR-dependent intracellular pathways offers new leads for the development of effective therapies for prostate cancer. (c) 2009 Wiley-Liss, Inc.

KDM1A triggers androgen-induced miRNA transcription via H3K4me2 demethylation and DNA oxidation.

PubMed

Yang, Shu; Zhang, Jiyuan; Zhang, Yalong; Wan, Xuechao; Zhang, Congzhe; Huang, Xiaohui; Huang, Wenhua; Pu, Honglei; Pei, Chaohan; Wu, Hai; Huang, Yan; Huang, Shengdong; Li, Yao

2015-06-15

Androgen receptor (AR) is a ligand dependent transcription factor that regulates the transcription of target genes. AR activity is closely involved in the maintenance and progression of prostate cancer. After the binding with androgen, AR moves into nucleus and binds to DNA sequence containing androgen response elements (ARE). Flavin-dependent monoamine oxidase KDM1A is necessary for AR driven transcription while the mechanism remains unclear. The association between androgen-dependent transcription and oxidation was tested through pharmaceutical inhibitions and siRNA knockdown of DNA oxidation repair components in prostate cancer cells. The recruitment of involved proteins and the histone methylation dynamics on ARE region was explored by chromatin immunoprecipitation (ChIP). Oxidation inhibition reduced AR dependent expression of KLK3, TMPRSS2, hsa-miR-125b2, and hsa-miR-133b. And such reduction could be restored by H2 O2 treatment. KDM1A recruitment and H3K4me2 demethylation on ARE regions, which produce H2 O2 , are associated with AR targets transcription. AR targets transcription and coupled oxidation recruit 8-oxoguanine-DNA glycosylase (OGG1) and the nuclease APEX1 to ARE regions. Such recruitment depends on KDM1A, and is necessary for AR targets transcription. Our work underlined the importance of histone demethylation and DNA oxidation/repairing machinery in androgen-dependent transcription. The present finds have implications for research into new druggable targets for prostate cancer relying on the cascade of AR activity regulation. © 2015 Wiley Periodicals, Inc.

Complex modulation of androgen responsive gene expression by methoxyacetic acid

PubMed Central

2011-01-01

Background Optimal androgen signaling is critical for testicular development and spermatogenesis. Methoxyacetic acid (MAA), the primary active metabolite of the industrial chemical ethylene glycol monomethyl ether, disrupts spermatogenesis and causes testicular atrophy. Transcriptional trans-activation studies have indicated that MAA can enhance androgen receptor activity, however, whether MAA actually impacts the expression of androgen-responsive genes in vivo, and which genes might be affected is not known. Methods A mouse TM3 Leydig cell line that stably expresses androgen receptor (TM3-AR) was prepared and analyzed by transcriptional profiling to identify target gene interactions between MAA and testosterone on a global scale. Results MAA is shown to have widespread effects on androgen-responsive genes, affecting processes ranging from apoptosis to ion transport, cell adhesion, phosphorylation and transcription, with MAA able to enhance, as well as antagonize, androgenic responses. Moreover, testosterone is shown to exert both positive and negative effects on MAA gene responses. Motif analysis indicated that binding sites for FOX, HOX, LEF/TCF, STAT5 and MEF2 family transcription factors are among the most highly enriched in genes regulated by testosterone and MAA. Notably, 65 FOXO targets were repressed by testosterone or showed repression enhanced by MAA with testosterone; these include 16 genes associated with developmental processes, six of which are Hox genes. Conclusions These findings highlight the complex interactions between testosterone and MAA, and provide insight into the effects of MAA exposure on androgen-dependent processes in a Leydig cell model. PMID:21453523

Cell Line Modeling to Study Biomarker Panel in Prostate Cancer

PubMed Central

NickKholgh, Bita; Fang, Xiaolan; Winters, Shira M.; Raina, Anvi; Pandya, Komal S.; Gyabaah, Kenneth; Fino, Nora; Balaji, K.C.

2016-01-01

BACKGROUND African–American men with prostate cancer (PCa) present with higher-grade and -stage tumors compared to Caucasians. While the disparity may result from multiple factors, a biological basis is often strongly suspected. Currently, few well-characterized experimental model systems are available to study the biological basis of racial disparity in PCa. We report a validated in vitro cell line model system that could be used for the purpose. METHODS We assembled a PCa cell line model that included currently available African–American PCa cell lines and LNCaP (androgen-dependent) and C4-2 (castration-resistant) Caucasian PCa cells. The utility of the cell lines in studying the biological basis of variance in a malignant phenotype was explored using a multiplex biomarker panel consisting of proteins that have been proven to play a role in the progression of PCa. The panel expression was evaluated by Western blot and RT-PCR in cell lines and validated in human PCa tissues by RT-PCR. As proof-of-principle to demonstrate the utility of our model in functional studies, we performed MTS viability assays and molecular studies. RESULTS The dysregulation of the multiplex biomarker panel in primary African–American cell line (E006AA) was similar to metastatic Caucasian cell lines, which would suggest that the cell line model could be used to study an inherent aggressive phenotype in African–American men with PCa. We had previously demonstrated that Protein kinase D1 (PKD1) is a novel kinase that is down regulated in advanced prostate cancer. We established the functional relevance by over expressing PKD1, which resulted in decreased proliferation and epithelial mesenchymal transition (EMT) in PCa cells. Moreover, we established the feasibility of studying the expression of the multiplex biomarker panel in archived human PCa tissue from African–Americans and Caucasians as a prelude to future translational studies. CONCLUSION We have characterized a novel in vitro cell line model that could be used to study the biological basis of disparity in PCa between African–Americans and Caucasians. PMID:26764245

Hsa-miR-146a-5p modulates androgen-independent prostate cancer cells apoptosis by targeting ROCK1.

PubMed

Xu, Bin; Huang, Yeqing; Niu, Xiaobing; Tao, Tao; Jiang, Liang; Tong, Na; Chen, Shuqiu; Liu, Ning; Zhu, Weidong; Chen, Ming

2015-12-01

MicroRNAs (miRNAs) have been demonstrated playing important roles in the procession of prostate cancer cells transformation from androgen-dependence to androgen-independence. We conducted the miRNA microarray and realtime PCR analyses in both androgen-dependent (ADPC) and androgen-independent prostate cancer (AIPC) tissues. We also explored the role of hsa-miR-146a-5p (miR-146a) in MSKCC prostate cancer clinical database. Moreover, the impact of miR-146a on prostate cancer cells apoptosis were detected by Hoechst staining and fluorescence-activated cell sorter (FACS). Its target is predicted by DIANA LAB online database and the result was assumed by western blotting and luciferase assay. We demonstrated that miR-146a was down-regulated in AIPC tissues and cell lines compared to that in the ADPC tissues. In MSKCC data re-analyses, we found that miR-146a was underexpressed in metastatic prostate cancer tissues and those with Gleason score >8, moreover, low level of miR-146a represented a high biochemical relapse rate after radical prostatectomy. In the functional analyses, we transfected miR-146a mimics into CPRC cell lines and found miR-146a induced cells apoptosis. In mechanic analyses, we found that miR-146a inhibited the basal level of Rho-associated, coiled-coil containing protein kinase 1 (ROCK1) expression by targeting its 3'UTR and an inverse correlation of expression between miR-146a and ROCK1 was observed. Moreover, caspase 3 activity was stimulated by miR-146a overexpression. miR-146a has a critical role in the process of AIPC prostate cancer cells apoptosis through regulation of ROCK/Caspase 3 pathway. Targeting this pathway may be a promising therapeutic strategy for future personalized anti-cancer treatment. © 2015 Wiley Periodicals, Inc.

Polyphenols in red wine inhibit the proliferation and induce apoptosis of LNCaP cells.

PubMed

Romero, I; Páez, A; Ferruelo, A; Luján, M; Berenguer, A

2002-06-01

To assess the effect of five polyphenol constituents of red wine (quercetin, morin, rutin, gallic acid and tannic acid) on the proliferation of LNCaP cells, and to quantify the extent of apoptosis with each polyphenol. LNCaP cells (500) were cultured in microtitre plates and treated with gallic acid, tannic acid, quercetin (1, 5 and 10 micromol/L), rutin and morin (25, 50 and 75 micromol/L). A colorimetric immunoassay was then used to determine the extent of proliferation at 24, 48, 72 and 96 h, and a cell-death detection assay to assess apoptosis at 24, 48 and 72 h. Gallic and tannic acid (5 and 10 micromol/L), morin (50 and 75 micromol/L), quercetin (5 and 10 micromol/L) and rutin (50 and 75 micromol/L) all significantly inhibited (P<0.05) cell proliferation compared with the control. Apoptotic indexes were significantly greater (P<0.01) in the presence of gallic (5 and 10 micromol/L) and tannic acid (5 and 10 micromol/L), and rutin (75 micromol/L, P<0.05) than in the control. The apoptotic effect of morin (75 micromol/L), although significant (P<0.01), only appeared at 72 h. Conversely, while significant (P<0.05) quercetin (5 and 10 micromol/L) had a transient (first 48 h) apoptotic effect compared with the control. Quercetin, rutin, morin, gallic acid and tannic acid inhibited the growth of LNCaP cells at different concentrations, and induced apoptosis. The results provide a strong rationale for studying the in vivo effects of these compounds.

Boric acid inhibits human prostate cancer cell proliferation.

PubMed

Barranco, Wade T; Eckhert, Curtis D

2004-12-08

The role of boron in biology includes coordinated regulation of gene expression in mixed bacterial populations and the growth and proliferation of higher plants and lower animals. Here we report that boric acid, the dominant form of boron in plasma, inhibits the proliferation of prostate cancer cell lines, DU-145 and LNCaP, in a dose-dependent manner. Non-tumorigenic prostate cell lines, PWR-1E and RWPE-1, and the cancer line PC-3 were also inhibited, but required concentrations higher than observed human blood levels. Studies using DU-145 cells showed that boric acid induced a cell death-independent proliferative inhibition, with little effect on cell cycle stage distribution and mitochondrial function.

Mitochondrial redox signaling by p66Shc is involved in regulating androgenic growth stimulation of human prostate cancer cells

PubMed Central

Veeramani, S; Yuan, T-C; Lin, F-F; Lin, M-F

2009-01-01

p66Shc is shown to negatively regulate the life span in mice through reactive oxygen species (ROS) production. Recent reports, however, revealed that p66Shc protein level is significantly elevated in several human cancer tissues and growth-stimulated carcinoma cells, suggesting a mitogenic and carcinogenic role for p66Shc. In this communication, we demonstrate for the first time that p66Shc mediates androgenic growth signals in androgen-sensitive human prostate cancer cells through mitochondrial ROS production. Growth stimulation of prostate cancer cells with 5α-dihydrotestosterone (DHT) is accompanied by increased p66Shc level and ROS production, which is abolished by antioxidant treatments. However, antioxidant treatments do not affect the transcriptional activity of androgen receptor (AR) as observed by its inability to block DHT-induced prostate-specific antigen expression, an AR-dependent correlate of prostate cancer progression. Elevated expression of p66Shc by cDNA transfection increases the basal cell proliferation and, thus, reduces additional DHT-induced cell proliferation. Furthermore, DHT increases the translocation of p66Shc into mitochondria and its interaction with cytochrome c. Conversely, both redox-negative p66Shc mutant (W134F), which is deficient in cytochrome c interaction, and p66Shc small interfering RNA decrease DHT-induced cell proliferation. These results collectively reveal a novel role for p66Shc–ROS pathway in androgen-induced prostate cancer cell proliferation and, thus, may play a role in early prostate carcinogenesis. PMID:18504439

EphA2 enhances the proliferation and invasion ability of LNCaP prostate cancer cells.

PubMed

Chen, Peijie; Huang, Yan; Zhang, Bo; Wang, Qiuquan; Bai, Peiming

2014-07-01

EphA2 is persistently overexpressed and functionally changed in numerous human cancers. However, to the best of our knowledge, the role that EphA2 plays in prostate cancer is not entirely clear. To investigate the roles of EphA2 in the development and progression of prostate cancer, the present study initially evaluated the roles of the EphA2 protein in LNCaP prostate cancer cells using recombinant plasmid, western blot analysis, flow cytometry, Matrigel invasion chamber and the cell counting kit-8 assay. An immunohistochemistry assay was also conducted to observe the effects of EphA2 in prostate cancer tissues. The results demonstrated that the LNCaP human prostate cancer cells that were transfected with pcDNA3.1(+) plasmid-mediated pcDNA3.1(+)-EphA2, markedly enhanced the cell growth and invasion in vitro . Additionally, EphA2 was overexpressed in prostate cancer specimens and the expression of EphA2 was significantly associated with Gleason grade, total prostate-specific antigen, advanced clinical stage and lymph node metastasis. Collectively, these results demonstrate that EphA2 is involved in malignant cell behavior and is a potential therapeutic target in human prostate cancer.

Hallmarks in prostate cancer imaging with Ga68-PSMA-11-PET/CT with reference to detection limits and quantitative properties.

PubMed

Sanchez-Crespo, Alejandro; Jussing, Emma; Björklund, Ann-Charlotte; Pokrovskaja Tamm, Katja

2018-04-04

Gallium-68-labeled prostate-specific antigen positron emission tomography/computed tomography imaging (Ga68-PSMA-11-PET/CT) has emerged as a potential gold standard for prostate cancer (PCa) diagnosis. However, the imaging limitations of this technique at the early state of PCa recurrence/metastatic spread are still not well characterized. The aim of this study was to determine the quantitative properties and the fundamental imaging limits of Ga68-PSMA-11-PET/CT in localizing small PCa cell deposits. The human PCa LNCaP cells (PSMA expressing) were grown and collected as single cell suspension or as 3D-spheroids at different cell numbers and incubated with Ga68-PSMA-11. Thereafter, human HCT116 cells (PSMA negative) were added to a total cell number of 2 × 10 5 cells per tube. The tubes were then pelleted and the supernatant aspirated. A whole-body PET/CT scanner with a clinical routine protocol was used for imaging the pellets inside of a cylindrical water phantom with increasing amounts of background activity. The actual activity bound to the cells was also measured in an automatic gamma counter. Imaging detection limits and activity recovery coefficients as a function of LNCaP cell number were obtained. The effect of Ga68-PSMA-11 mass concentration on cell binding was also investigated in samples of LnCaP cells incubated with increasing concentrations of radioligand. A total of 1 × 10 4 LNCaP cells mixed in a pellet of 2 × 10 5 cells were required to reach a 50% detection probability with Ga68-PSMA-11-PET/CT without background. With a background level of 1 kBq/ml, between 4 × 10 5 and 1 × 10 6 cells are required. The radioligand equilibrium dissociation constant was 27.05 nM, indicating high binding affinity. Hence, the specific activity of the radioligand has a profound effect on image quantification. Ga68-PSMA-11-PET detects a small number of LNCaP cells even when they are mixed in a population of non-PSMA expressing cells and in the presence of background. The obtained image detection limits and characteristic quantification properties of Ga68-PSMA-11-PET/CT are essential hallmarks for the individualization of patient management. The use of the standardized uptake value for Ga68-PSMA-11-PET/CT image quantification should be precluded.

Snail regulates cell survival and inhibits cellular senescence in human metastatic prostate cancer cell lines.

PubMed

Emadi Baygi, Modjtaba; Soheili, Zahra Soheila; Schmitz, Ingo; Sameie, Shahram; Schulz, Wolfgang A

2010-12-01

The epithelial-mesenchymal transition (EMT) is regarded as an important step in cancer metastasis. Snail, a master regulator of EMT, has been recently proposed to act additionally as a cell survival factor and inducer of motility. We have investigated the function of Snail (SNAI1) in prostate cancer cells by downregulating its expression via short (21-mer) interfering RNA (siRNA) and measuring the consequences on EMT markers, cell viability, death, cell cycle, senescence, attachment, and invasivity. Of eight carcinoma cell lines, the prostate carcinoma cell lines LNCaP and PC-3 showed the highest and moderate expression of SNAI1 mRNA, respectively, as measured by quantitative RT-PCR. Long-term knockdown of Snail induced a severe decline in cell numbers in LNCaP and PC-3 and caspase activity was accordingly enhanced in both cell lines. In addition, suppression of Snail expression induced senescence in LNCaP cells. SNAI1-siRNA-treated cells did not tolerate detachment from the extracellular matrix, probably due to downregulation of integrin α6. Expression of E-cadherin, vimentin, and fibronectin was also affected. Invasiveness of PC-3 cells was not significantly diminished by Snail knockdown. Our data suggest that Snail acts primarily as a survival factor and inhibitor of cellular senescence in prostate cancer cell lines. We therefore propose that Snail can act as early driver of prostate cancer progression.

Interactions between androgens, FSH, anti-Müllerian hormone and estradiol during folliculogenesis in the human normal and polycystic ovary.

PubMed

Dewailly, Didier; Robin, Geoffroy; Peigne, Maëliss; Decanter, Christine; Pigny, Pascal; Catteau-Jonard, Sophie

2016-11-01

Androgens, FSH, anti-Müllerian hormone (AMH) and estradiol (E2) are essential in human ovarian folliculogenesis. However, the interactions between these four players is not fully understood. The purpose of this review is to highlight the chronological sequence of the appearance and function of androgens, FSH, AMH and E2 and to discuss controversies in the relationship between FSH and AMH. A better understanding of this interaction could supplement our current knowledge about the pathophysiology of the polycystic ovary syndrome (PCOS). A literature review was performed using the following search terms: androgens, FSH, FSH receptor, anti-Mullerian hormone, AMHRII, estradiol, follicle, ovary, PCOS, aromatase, granulosa cell, oocyte. The time period searched was 1980-2015 and the databases interrogated were PubMed and Web of Science. During the pre-antral ('gonadotropin-independent') follicle growth, FSH is already active and promotes follicle growth in synergy with theca cell-derived androgens. Conversely, AMH is inhibitory by counteracting FSH. We challenge the hypothesis that AMH is regulated by androgens and propose rather an indirect effect through an androgen-dependent amplification of FSH action on granulosa cells (GCs) from small growing follicles. This hypothesis implies that FSH stimulates AMH expression. During the antral ('gonadotropin-dependent') follicle growth, E2 production results from FSH-dependent activation of aromatase. Conversely, AMH is inhibitory but the decline of its expression, amplified by E2, allows full expression of aromatase, characteristic of the large antral follicles. We propose a theoretical scheme made up of two triangles that follow each other chronologically. In PCOS, pre-antral follicle growth is excessive (triangle 1) because of intrinsic androgen excess that renders GCs hypersensitive to FSH, with consequently excessive AMH expression. Antral follicle growth and differentiation are disturbed (triangle 2) because of the abnormally persisting inhibition of FSH effects by AMH that blocks aromatase. Beside anovulation, this scenario may also serve to explain the higher receptiveness to gonadotropin therapy and the increased risk of ovarian hyperstimulation syndrome (OHSS) in patients with PCOS. Within GCs, the balance between FSH and AMH effects is pivotal in the shift from androgen- to oestrogen-driven follicles. Our two triangles hypothesis, based on updated data from the literature, offers a pedagogic template for the understanding of folliculogenesis in the normal and polycystic ovary. It opens new avenues for the treatment of anovulation due to PCOS. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mouse Leydig Cells with Different Androgen Production Potential Are Resistant to Estrogenic Stimuli but Responsive to Bisphenol A Which Attenuates Testosterone Metabolism

PubMed Central

Savchuk, Iuliia; Söder, Olle; Svechnikov, Konstantin

2013-01-01

It is well known that estrogens and estrogen-like endocrine disruptors can suppress steroidogenic gene expression, attenuate androgen production and decrease differentiation of adult Leydig cell lineage. However, there is no information about the possible link between the potency of Leydig cells to produce androgens and their sensitivity to estrogenic stimuli. Thus, the present study explored the relationship between androgen production potential of Leydig cells and their responsiveness to estrogenic compounds. To investigate this relationship we selected mouse genotypes contrasting in sex hormone levels and differing in testosterone/estradiol (T/E2) ratio. We found that two mouse genotypes, CBA/Lac and C57BL/6j have the highest and the lowest serum T/E2 ratio associated with increased serum LH level in C57BL/6j compared to CBA/Lac. Analysis of steroidogenic gene expression demonstrated significant upregulation of Cyp19 gene expression but coordinated suppression of LHR, StAR, 3βHSDI and Cyp17a1 in Leydig cells from C57BL/6j that was associated with attenuated androgen production in basal and hCG-stimulated conditions compared to CBA/Lac mice. These genotype-dependent differences in steroidogenesis were not linked to changes in the expression of estrogen receptors ERα and Gpr30, while ERβ expression was attenuated in Leydig cells from C57BL/6j compared to CBA/Lac. No effects of estrogenic agonists on steroidogenesis in Leydig cells from both genotypes were found. In contrast, xenoestrogen bisphenol A significantly potentiated hCG-activated androgen production by Leydig cells from C57BL/6j and CBA/Lac mice by suppressing conversion of testosterone into corresponding metabolite 5α-androstane-3α,17β-diol. All together our data indicate that developing mouse Leydig cells with different androgen production potential are resistant to estrogenic stimuli, while xenoestrogen BPA facilitates hCG-induced steroidogenesis in mouse Leydig cells via attenuation of testosterone metabolism. This cellular event can cause premature maturation of Leydig cells that may create abnormal intratesticular paracrine milieu and disturb proper development of germ cells. PMID:23967237

Antitumoral, antihypertensive, antimicrobial, and antioxidant effects of an octanuclear copper(II)-telmisartan complex with an hydrophobic nanometer hole.

PubMed

Islas, María S; Martínez Medina, Juan J; López Tévez, Libertad L; Rojo, Teófilo; Lezama, Luis; Griera Merino, Mercedes; Calleros, Laura; Cortes, María A; Rodriguez Puyol, Manuel; Echeverría, Gustavo A; Piro, Oscar E; Ferrer, Evelina G; Williams, Patricia A M

2014-06-02

A new Cu(II) complex with the antihypertensive drug telmisartan, [Cu8Tlm16]·24H2O (CuTlm), was synthesized and characterized by elemental analysis and electronic, FTIR, Raman and electron paramagnetic resonance spectroscopy. The crystal structure (at 120 K) was solved by X-ray diffraction methods. The octanuclear complex is a hydrate of but otherwise isostructural to the previously reported [Cu8Tlm16] complex. [Cu8Tlm16]·24H2O crystallizes in the tetragonal P4/ncc space group with a = b = 47.335(1), c = 30.894(3) Å, Z = 4 molecules per unit cell giving a macrocyclic ring with a double helical structure. The Cu(II) ions are in a distorted bipyramidal environment with a somewhat twisted square basis, cis-coordinated at their core N2O2 basis to two carboxylate oxygen and two terminal benzimidazole nitrogen atoms. Cu8Tlm16 has a toroidal-like shape with a hydrophobic nanometer hole, and their crystal packing defines nanochannels that extend along the crystal c-axis. Several biological activities of the complex and the parent ligand were examined in vitro. The antioxidant measurements indicate that the complex behaves as a superoxide dismutase mimic with improved superoxide scavenger power as compared with native sartan. The capacity of telmisartan and its copper complex to expand human mesangial cells (previously contracted by angiotensin II treatment) is similar to each other. The antihypertensive effect of the compounds is attributed to the strongest binding affinity to angiotensin II type 1 receptor and not to the antioxidant effects. The cytotoxic activity of the complex and that of its components was determined against lung cancer cell line A549 and three prostate cancer cell lines (LNCaP, PC-3, and DU 145). The complex displays some inhibitory effect on the A549 line and a high viability decrease on the LNCaP (androgen-sensitive) line. From flow cytometric analysis, an apoptotic mechanism was established for the latter cell line. Telmisartan and CuTlm show antibacterial and antifungal activities in various strains, and CuTlm displays improved activity against the Staphylococcus aureus strain as compared with unbounded copper(II).

T CELLS LOCALIZED TO THE ANDROGEN-DEPRIVED PROSTATE ARE TH1 AND TH17 BIASED

PubMed Central

Morse, Matthew D.; McNeel, Douglas G.

2013-01-01

BACKGROUND T cells infiltrate the prostates of prostate cancer patients undergoing neoadjuvant androgen deprivation. These prostate-infiltrating T cells have an oligoclonal phenotype, suggesting the development of an antigen-specific T-cell response. We hypothesized that androgen deprivation might elicit a prostate tissue-specific T-cell response that could potentially be combined with other immune-active therapies, and consequently sought to investigate the nature and timing of this T-cell response following castration. METHODS We investigated the phenotype and cytokine expression of T cells at various time points in the prostates of Lewis rats following surgical castration, and used adoptive transfer of prostate-infiltrating lymphocytes to determine whether the infiltration by T cells was mediated by effects of castration on the prostate or lymphocytes. RESULTS Prostate T-cell infiltration shortly after castration was TH1 biased up to approximately 30 days, followed by a predominance of TH17-type cells, which persisted until at least 90 days post castration. Prostate-infiltrating lymphocytes from sham-treated or castrate rats localized to the prostates of castrate animals. CONCLUSIONS These observations suggest castration elicits a time-dependent prostate-specific T-cell infiltration, and this infiltration is likely mediated by effects of castration on prostate tissue rather than T cells. These findings have implications for the timing of immunotherapies combined with androgen deprivation as treatments for prostate cancer. PMID:22213030

Response of Human Prostate Cancer Cells to Mitoxantrone Treatment in Simulated Microgravity Environment

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wu, Honglu

2012-07-01

RESPONSE OF HUMAN PROSTATE CANCER CELLS TO MITOXANTRONE TREATMENT IN SIMULATED MICROGRAVITY ENVIRONMENT Ye Zhang1,2, Christopher Edwards3, and Honglu Wu1 1 NASA-Johnson Space Center, Houston, TX 2 Wyle Integrated Science and Engineering Group, Houston, TX 3 Oregon State University, Corvallis, OR This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of an antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to the treatment of drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulations of cells in response to antineoplastic agents, we cultured LNCaP cells in either a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as control, and treated the cells with mitoxantrone. Cell growth, as well as expressions of oxidative stress related genes, were analyzed after the drug treatment. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not present significant differences in cell viability, growth rate, or cell cycle distribution. However, after mitoxantrone treatment, a significant proportion of bioreactor cultured cells became apoptotic or was arrested in G2. Several oxidative stress related genes also showed a higher expression level post mitoxantrone treatment. Our results indicate that simulated microgravity may alter the response of LNCaP cells to mitoxantrone treatment. Understanding the mechanisms by which cells respond to drugs differently in an altered gravity environment will be useful for the improvement of cancer treatment on the ground. This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of an antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to the treatment of drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulations of cells in response to antineoplastic agents, we cultured LNCaP cells in either a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as control, and treated the cells with mitoxantrone. Cell growth, as well as expressions of oxidative stress related genes, were analyzed after the drug treatment. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not present significant differences in cell viability, growth rate, or cell cycle distribution. However, after mitoxantrone treatment, a significant proportion of bioreactor cultured cells became apoptotic or was arrested in G2. Several oxidative stress related genes also showed a higher expression level post mitoxantrone treatment. Our results indicate that simulated microgravity may alter the response of LNCaP cells to mitoxantrone treatment. Understanding the mechanisms by which cells respond to drugs differently in an altered gravity environment will be useful for the improvement of cancer treatment on the ground.

Optimization and comprehensive characterization of a faithful tissue culture model of the benign and malignant human prostate.

PubMed

Maund, Sophia Lisette; Nolley, Rosalie; Peehl, Donna Mae

2014-02-01

Few preclinical models accurately depict normal human prostate tissue or primary prostate cancer (PCa). In vitro systems typically lack complex cellular interactions among structured prostatic epithelia and a stromal microenvironment, and genetic and molecular fidelity are concerns in both in vitro and in vivo models. 'Tissue slice cultures' (TSCs) provide realistic preclinical models of diverse tissues and organs, but have not been fully developed or widely utilized for prostate studies. Problems encountered include degeneration of differentiated secretory cells, basal cell hyperplasia, and poor survival of PCa. Here, we optimized, characterized, and applied a TSC model of primary human PCa and benign prostate tissue that overcomes many deficiencies of current in vitro models. Tissue cores from fresh prostatectomy specimens were precision-cut at 300 μm and incubated in a rotary culture apparatus. The ability of varied culture conditions to faithfully maintain benign and cancer cell and tissue structure and function over time was evaluated by immunohistological and biochemical assays. After optimization of the culture system, molecular and cellular responses to androgen ablation and to piperlongumine (PL), purported to specifically reduce androgen signaling in PCa, were investigated. Optimized culture conditions successfully maintained the structural and functional fidelity of both benign and PCa TSCs for 5 days. TSCs exhibited androgen dependence, appropriately undergoing ductal degeneration, reduced proliferation, and decreased prostate-specific antigen expression upon androgen ablation. Further, TSCs revealed cancer-specific reduction of androgen receptor and increased apoptosis upon treatment with PL, validating data from cell lines. We demonstrate a TSC model that authentically recapitulates the structural, cellular, and genetic characteristics of the benign and malignant human prostate, androgen dependence of the native tissue, and cancer-specific response to a potentially new therapeutic for PCa. The work described herein provides a basis for advancing the experimental utility of the TSC model.

Androgen regulation of the human hair follicle: the type I hair keratin hHa7 is a direct target gene in trichocytes.

PubMed

Jave-Suarez, Luis F; Langbein, Lutz; Winter, Hermelita; Praetzel, Silke; Rogers, Michael A; Schweizer, Juergen

2004-03-01

Previous work had shown that most members of the complex human hair keratin family were expressed in terminal scalp hairs. An exception to this rule was the type I hair keratin hHa7, which was only detected in some but not all vellus hairs of the human scalp (Langbein et al, 1999). Here we show that hHa7 exhibits constitutive expression in medullary cells of all types of male and female sexual hairs. Medullated beard, axillary, and pubic hairs arise during puberty from small, unmedullated vellus hairs under the influence of circulating androgens. This suggested an androgen-controlled expression of the hHa7 gene. Further evidence for this assumption was provided by the demonstration of androgen receptor (AR) expression in the nuclei of medullary cells of beard hairs. Moreover, homology search for the semipalindromic androgen receptor-binding element (ARE) consensus sequence GG(A)/(T)ACAnnnTGTTCT in the proximal hHa7 promoter revealed three putative ARE motifs. Electrophoretic mobility shift assays demonstrated the specific binding of AR to all three hHa7 AREs. Their function as AR-responsive elements, either individually or in concert within the hHa7 promoter, could be further confirmed by transfection studies with or without an AR expression vector in PtK2 and prostate PC3-Arwt cells, respectively in the presence or absence of a synthetic androgen. Our study detected hHa7 as the first gene in hair follicle trichocytes whose expression appears to be directly regulated by androgens. As such, hHa7 represents a marker for androgen action on hair follicles and might be a suitable tool for investigations of androgen-dependent hair disorders.

Stimulatory effect of insulin on 5alpha-reductase type 1 (SRD5A1) expression through an Akt-dependent pathway in ovarian granulosa cells.

PubMed

Kayampilly, Pradeep P; Wanamaker, Brett L; Stewart, James A; Wagner, Carrie L; Menon, K M J

2010-10-01

Elevated levels of 5α-reduced androgens have been shown to be associated with hyperandrogenism and hyperinsulinemia, the leading causes of ovulatory dysfunction in women. 5α-Dihydrotestosterone reduces ovarian granulosa cell proliferation by inhibiting FSH-mediated mitogenic signaling pathways. The present study examined the effect of insulin on 5α-reductase, the enzyme that catalyses the conversion of androgens to their 5α-derivatives. Granulosa cells isolated from immature rat ovaries were cultured in serum-free, phenol red-free DMEM-F12 media and treated with different doses of insulin (0, 0.1, 1.0, and 10.0 μg/ml) for different time intervals up to 12 h. The expression of 5α-reductase type 1 mRNA, the predominant isoform found in granulosa cells, showed a significant (P<0.05) increase in response to the insulin treatment up to 12 h compared with control. The catalytic activity of 5α-reductase enzyme was also stimulated in a dose-depended manner (P<0.05). Inhibiting the Akt-dependent signaling pathway abolished the insulin-mediated increase in 5α-reductase mRNA expression, whereas inhibition of the ERK-dependent pathway had no effect. The dose-dependent increase in 5α-reductase mRNA expression as well as catalytic activity seen in response to insulin treatment was also demonstrated in the human granulosa cell line (KGN). In addition to increased mRNA expression, a dose-dependent increase in 5α-reductase protein expression in response to insulin was also seen in KGN cells, which corroborated well with that of mRNA expression. These results suggest that elevated levels of 5α-reduced androgens seen in hyperinsulinemic conditions might be explained on the basis of a stimulatory effect of insulin on 5α-reductase in granulosa cells. The elevated levels of these metabolites, in turn, might adversely affect growth and proliferation of granulosa cells, thereby impairing follicle growth and ovulation.

Androgen-induced alterations in endometrial proteins crucial in recurrent miscarriages.

PubMed

Rahman, Tanzil Ur; Ullah, Kamran; Guo, Meng-Xi; Pan, Hai-Tao; Liu, Juan; Ren, Jun; Jin, Lu-Yang; Zhou, Yu-Zhong; Cheng, Yi; Sheng, Jian-Zhong; Huang, He-Feng

2018-05-15

High androgen level impairs endometrial receptivity in women experiences the recurrent miscarriage. The mechanism of androgen actions on endometrium is still uncertain. We hypothesized that androgen has a direct effect on the endometrium in women with recurrent miscarriage. In the present study, we assess the impact of androgen (A 2 ) at high concentration (10 -7 M) on Ishikawa cells compared with the physiological concentration of androgen (10 -9 M). To go into deeper analysis, we use global stable isotopes labeled profiling tactic using iTRAQ reagents, followed by 2D LC-MS/MS. We determine 175 non-redundant proteins, and 18 of these were quantified. The analysis of differentially expressed proteins (DEPs) identified 8 up-regulated proteins and 10 down-regulated in the high androgen group. These DEPs were examined by ingenuity pathway (IPA) analysis and established that these proteins might play vital roles in recurrent miscarriage and endometrium receptivity. In addition, proteins cyclin-dependent kinase inhibitor 2a (CDKN2a), endothelial protein C receptor (EPCR), armadillo repeat for velocardiofacial (ARVCF) were independently confirmed using western blot. Knockdown of CDKN2a significantly decreased the expression level of CDKN2a protein in ishikawa cells, and decreased migration ( p < 0.01), invasion ( p < 0.05), proliferation ( p < 0.05), and the rate of Jar spheroid attachment ( p < 0.05) to Ishikawa cell monolayer. The present results suggest that androgen at high concentration could alter the expression levels of proteins related to endometrium development and embryo implantation, which might be a cause of the impaired endometrial receptivity and miscarriage.

Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina

PubMed Central

Larkins, Christine E.; Enriquez, Ana B.; Cohn, Martin J.

2016-01-01

Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development. PMID:27821748

Spatiotemporal dynamics of androgen signaling underlie sexual differentiation and congenital malformations of the urethra and vagina.

PubMed

Larkins, Christine E; Enriquez, Ana B; Cohn, Martin J

2016-11-22

Disorders of sex development (DSDs) are congenital anomalies that affect sexual differentiation of genitourinary organs and secondary sex characters. A common cause of female genital virilization is congenital adrenal hyperplasia (CAH), in which excess androgen production during development of 46XX females can result in vaginal atresia, masculinization of the urethra, a single urogenital sinus, and clitoral hypertrophy or ambiguous external genitalia. Development of the vagina depends on sexual differentiation of the urogenital sinus ridge, an epithelial thickening that forms where the sex ducts attach to the anterior urethra. In females, the sinus ridge descends posteriorly to allow the vaginal opening to form in the vulva, whereas in males and in females with CAH, androgens inhibit descent of the sinus ridge. The mechanisms that regulate development of the female urethra and vagina are largely unknown. Here we show that the timing and duration of, and the cell population targeted by, androgen signaling determine the position of vaginal attachment to the urethra. Manipulations of androgen signaling in utero reveal a temporal window of development when sinus ridge fate is determined. Cell type-specific genetic deletions of androgen receptor (Ar) identify a subpopulation of mesenchymal cells that regulate sinus ridge morphogenesis. These results reveal a common mechanism that coordinates development of the vagina and feminization of the urethra, which may account for development of a single urogenital sinus in females exposed to excessive androgen during a critical period of prenatal development.

Castration Resistance in Prostate Cancer Is Mediated by the Kinase NEK6. | Office of Cancer Genomics

Cancer.gov

In prostate cancer, the development of castration resistance is pivotal in progression to aggressive disease. However, understanding of the pathways involved remains incomplete. In this study, we performed a high-throughput genetic screen to identify kinases that enable tumor formation by androgen-dependent prostate epithelial (LHSR-AR) cells under androgen-deprived conditions.

Discriminatory Role of Detergent-Resistant Membranes in the Dimerization and Endocytosis of Prostate-Specific Membrane Antigen.

PubMed

Schmidt, Sonja; Gericke, Birthe; Fracasso, Giulio; Ramarli, Dunia; Colombatti, Marco; Naim, Hassan Y

2013-01-01

Prostate-specific membrane antigen (PSMA) is a type-II membrane glycoprotein that was initially identified in LNCaP cells. It is expressed at elevated levels in prostate cancer. In view of the correlation between the expression levels of PSMA and disease grade and stage, PSMA is considered to be one of the most promising biomarkers in the diagnosis and treatment of prostate cancer. In LNCaP cells PSMA undergoes internalization via clathrin-coated pits followed by accumulation in the endosomes. PSMA associates with different types of detergent-resistant membranes (DRMs) along the secretory pathway. Its mature form is mainly insoluble in Lubrol WX, but does not associate with Triton X-100-DRMs. To understand the mechanism of PSMA internalization we investigated its association during internalization with DRMs. For this purpose, internalization was induced by antibody cross-linking. We demonstrate at the biochemical and cell biological levels that: [i] exclusively homodimers of PSMA are associated with Lubrol WX-DRMs, [ii] antibody-induced cross-linking of PSMA molecules results in a time-dependent partitioning into another DRMs type, namely Triton X-100-DRMs, and [iii] concomitant with its association with Triton-X-100-DRMs internalization of PSMA occurs along tubulin filaments. In a previous work (Colombatti et al. (2009) PLoS One 4: e4608) we demonstrated that the small GTPases RAS and RAC1 and the MAPKs p38 and ERK1/2 are activated during antibody cross-linking. As downstream effects of this activation we observed a strong induction of NF-kB associated with an increased expression of IL-6 and CCL5 genes and that IL-6 and CCL5 enhanced the proliferative potential of LNCaP cells synergistically. These observations together with findings reported here hypothesize a fundamental role of DRMs during activation of PSMA as platforms for trafficking, endocytosis and signalling. Understanding these mechanisms constitutes an essential prerequisite for utilization of PSMA as a therapeutically suitable target in prostate cancer.

Discriminatory Role of Detergent-Resistant Membranes in the Dimerization and Endocytosis of Prostate-Specific Membrane Antigen

PubMed Central

Schmidt, Sonja; Gericke, Birthe; Fracasso, Giulio; Ramarli, Dunia; Colombatti, Marco; Naim, Hassan Y.

2013-01-01

Prostate-specific membrane antigen (PSMA) is a type-II membrane glycoprotein that was initially identified in LNCaP cells. It is expressed at elevated levels in prostate cancer. In view of the correlation between the expression levels of PSMA and disease grade and stage, PSMA is considered to be one of the most promising biomarkers in the diagnosis and treatment of prostate cancer. In LNCaP cells PSMA undergoes internalization via clathrin-coated pits followed by accumulation in the endosomes. PSMA associates with different types of detergent-resistant membranes (DRMs) along the secretory pathway. Its mature form is mainly insoluble in Lubrol WX, but does not associate with Triton X-100-DRMs. To understand the mechanism of PSMA internalization we investigated its association during internalization with DRMs. For this purpose, internalization was induced by antibody cross-linking. We demonstrate at the biochemical and cell biological levels that: [i] exclusively homodimers of PSMA are associated with Lubrol WX-DRMs, [ii] antibody-induced cross-linking of PSMA molecules results in a time-dependent partitioning into another DRMs type, namely Triton X-100-DRMs, and [iii] concomitant with its association with Triton-X-100-DRMs internalization of PSMA occurs along tubulin filaments. In a previous work (Colombatti et al. (2009) PLoS One 4: e4608) we demonstrated that the small GTPases RAS and RAC1 and the MAPKs p38 and ERK1/2 are activated during antibody cross-linking. As downstream effects of this activation we observed a strong induction of NF-kB associated with an increased expression of IL-6 and CCL5 genes and that IL-6 and CCL5 enhanced the proliferative potential of LNCaP cells synergistically. These observations together with findings reported here hypothesize a fundamental role of DRMs during activation of PSMA as platforms for trafficking, endocytosis and signalling. Understanding these mechanisms constitutes an essential prerequisite for utilization of PSMA as a therapeutically suitable target in prostate cancer. PMID:23840421

Cell growth inhibition and apoptotic effects of a specific anti-RTFscFv antibody on prostate cancer, but not glioblastoma, cells

PubMed Central

Nejatollahi, Foroogh; Bayat, Payam; Moazen, Bahareh

2017-01-01

Background: Single chain antibody (scFv) has shown interesting results in cancer immunotargeting approaches, due to its advantages over monoclonal antibodies. Regeneration and tolerance factor (RTF) is one of the most important regulators of extracellular and intracellular pH in eukaryotic cells. In this study, the inhibitory effects of a specific anti-RTF scFv were investigated and compared between three types of prostate cancer and two types of glioblastoma cells.  Methods: A phage antibody display library of scFv was used to select specific scFvs against RTF using panning process. The reactivity of a selected scFv was assessed by phage ELISA. The anti-proliferative and apoptotic effects of the antibody on prostate cancer (PC-3, Du-145 and LNCaP) and glioblastoma (U-87 MG and A-172) cell lines were investigated by MTT and Annexin V/PI assays.  Results: A specific scFv with frequency 35% was selected against RTF epitope. This significantly inhibited the proliferation of the prostate cells after 24 h. The percentages of cell viability (using 1000 scFv/cell) were 52, 61 and 73% for PC-3, Du-145 and LNCaP cells, respectively, compared to untreated cells. The antibody (1000 scFv/cell) induced apoptosis at 50, 40 and 25% in PC-3, Du-145 and LNCaP cells, respectively. No growth inhibition and apoptotic induction was detected for U-87 and A172 glioblastoma cells.  Conclusions: Anti-RTFscFv significantly reduced the proliferation of the prostate cancer cells. The inhibition of cell growth and apoptotic induction effects in PC-3 cells were greater than Du-145 and LNCaP cells. This might be due to higher expression of RTF antigen in PC-3 cells and/or better accessibility of RTF to scFv antibody. The resistance of glioblastoma cells to anti-RTF scFv offers the existence of mechanism(s) that abrogate the inhibitory effect(s) of the antibody to RTF. The results suggest that the selected anti-RTF scFv antibody could be an effective new alternative for prostate cancer immunotherapy. PMID:28491282

Identification of miR-133b and RB1CC1 as independent predictors for biochemical recurrence and potential therapeutic targets for prostate cancer.

PubMed

Li, Xia; Wan, Xuechao; Chen, Hongbing; Yang, Shu; Liu, Yiyang; Mo, Wenjuan; Meng, Delong; Du, Wenting; Huang, Yan; Wu, Hai; Wang, Jingqiang; Li, Tao; Li, Yao

2014-05-01

We aimed to investigate the contribution of microRNA-133b (miR-133b) in prostate cancer cell proliferation, cell cycle, and apoptosis. We also examined expression of miR-133b in prostate cancer tissues, and evaluated the prognostic significance of miR-133b, as well as its target gene RB1CC1 in patients with prostate cancer after radical prostatectomy. miR-133b mimics (miR-133bm) and anti-miR-133b were transfected into LNCaP and PC-3 cells. CCK-8 was used to look at cell proliferation, flow cytometric analysis was carried out to study cell cycle, and apoptosis was determined by caspase-3 activity. miR-133b expression was assessed by real-time reverse transcription PCR and in situ hybridization in prostatic cell lines and 178 prostate tissue samples, respectively. The protein level of RB1CC1 was examined by Western blot and immunohistochemistry in prostatic cell lines and prostate tissue samples, respectively. Overexpression of miR-133b in LNCaP cells boosted cell proliferation and cell-cycle progression, but inhibited apoptosis; in contrast, miR-133bm promoted cell apoptosis, but suppressed cell proliferation and cell-cycle progression in PC-3 cells. In LNCaP cells, silencing of RB1CC1, a target of miR-133b, inhibited cell apoptosis, and promoted cell-cycle progression. Moreover, miR-133b expression was significantly inversely correlated with RB1CC1 expression in prostate cancer tissues. Multivariate Cox analysis indicated that miR-133b and RB1CC1 might be two independent prognostic factors of biochemical recurrence. miR-133b might enhance tumor-promoting properties in less aggressive LNCaP cells, whereas this miR may act as a tumor suppressor in more aggressive PC-3 cells. miR-133b and RB1CC1 were independent prognostic indicators for prostate cancer. ©2014 AACR.

A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland

PubMed Central

Pakula, Hubert; Xiang, Dongxi; Li, Zhe

2017-01-01

Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent. PMID:28134791

A Tale of Two Signals: AR and WNT in Development and Tumorigenesis of Prostate and Mammary Gland.

PubMed

Pakula, Hubert; Xiang, Dongxi; Li, Zhe

2017-01-27

Prostate cancer (PCa) is one of the most common cancers and among the leading causes of cancer deaths for men in industrialized countries. It has long been recognized that the prostate is an androgen-dependent organ and PCa is an androgen-dependent disease. Androgen action is mediated by the androgen receptor (AR). Androgen deprivation therapy (ADT) is the standard treatment for metastatic PCa. However, almost all advanced PCa cases progress to castration-resistant prostate cancer (CRPC) after a period of ADT. A variety of mechanisms of progression from androgen-dependent PCa to CRPC under ADT have been postulated, but it remains largely unclear as to when and how castration resistance arises within prostate tumors. In addition, AR signaling may be modulated by extracellular factors among which are the cysteine-rich glycoproteins WNTs. The WNTs are capable of signaling through several pathways, the best-characterized being the canonical WNT/β-catenin/TCF-mediated canonical pathway. Recent studies from sequencing PCa genomes revealed that CRPC cells frequently harbor mutations in major components of the WNT/β-catenin pathway. Moreover, the finding of an interaction between β-catenin and AR suggests a possible mechanism of cross talk between WNT and androgen/AR signaling pathways. In this review, we discuss the current knowledge of both AR and WNT pathways in prostate development and tumorigenesis, and their interaction during development of CRPC. We also review the possible therapeutic application of drugs that target both AR and WNT/β-catenin pathways. Finally, we extend our review of AR and WNT signaling to the mammary gland system and breast cancer. We highlight that the role of AR signaling and its interaction with WNT signaling in these two hormone-related cancer types are highly context-dependent.

Novel Therapeutic Targets to Inhibit Tumor Microenvironment-Induced Castration Resistant Prostate Cancer

DTIC Science & Technology

2016-10-01

MAPK4. We are also in the process of generating MAPK4-knockout LNCaP cells using the CRISPR /Cas9 system. Altogether, we hope that we can generate the...engineered LNCaP cells that are stable for either total loss of MAPK4 ( CRISPR /Cas9 knockout) or with inducible knockdown of MAPK4 (Dox-inducible...knockdown or CRISPR /Cas9 mediated knockout of MAPK4 (we are working on them). Major Task 2: Determine whether inhibition of MAPK4 (in PCa) and TGF-β

Deregulation of miRNAs Contributes to Development and Progression of Prostate Cancer

DTIC Science & Technology

2012-09-01

p14ARF gene were co-transfected with miR-125b into LNCaP cells. Cotransfection resulted in approximately 50% reduction of the enzyme activity (Fig...Figure3. Downregulation of miR-125b activity induces apoptosis in p53-null CaP cells. A) Western blot analysis of p14ARF and...miR-124-mediated downregulation of the AR affects the AR activity , both AR- positive LNCaP and C4-2B were treated with miR-124 mimic. Western blot

Effects of fenoterol on the skeletal system depend on the androgen level.

PubMed

Śliwiński, Leszek; Cegieła, Urszula; Pytlik, Maria; Folwarczna, Joanna; Janas, Aleksandra; Zbrojkiewicz, Małgorzata

2017-04-01

The role of sympathetic nervous system in the osseous tissue remodeling is not clear enough. The effects of fenoterol, a selective β 2 -adrenomimetic drug, on the skeletal system of normal and androgen deficient (orchidectomized) rats were studied in vivo. Osteoclastogenesis and mRNA expression in osteoblasts were investigated in vitro in mouse cell cultures. Fenoterol administered to animals with physiological androgen level unfavorably affected the skeletal system, damaging the bone microarchitecture. Androgen deficiency induced osteoporotic changes, and fenoterol protected the osseous tissue from consequences of androgen deficiency. The results of in vitro studies correlated with the in vivo observations. A significantly increased number of osteoclasts in bone marrow cell cultures to which testosterone and fenoterol were added simultaneously was demonstrated. In cultures without the addition of testosterone, fenoterol significantly inhibited osteoclastogenesis in comparison with control cultures. The results indicate the favorable action of fenoterol in conditions of testosterone deficiency, and its destructive influence upon the skeleton in the presence of androgens. The results confirm the key role of sympathetic nervous system in the regulation of bone remodeling. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

Computational Modeling and Simulation of Genital Tubercle Development

EPA Pesticide Factsheets

Hypospadias is a developmental defect of urethral tube closure that has a complex etiology involving genetic and environmental factors, including anti-androgenic and estrogenic disrupting chemicals; however, little is known about the morphoregulatory consequences of androgen/estrogen balance during genital tubercle (GT) development. Computer models that predictively model sexual dimorphism of the GT may provide a useful resource to translate chemical-target bipartite networks and their developmental consequences across the human-relevant chemical universe. Here, we describe a multicellular agent-based model of genital tubercle (GT) development that simulates urethrogenesis from the sexually-indifferent urethral plate stage to urethral tube closure. The prototype model, constructed in CompuCell3D, recapitulates key aspects of GT morphogenesis controlled by SHH, FGF10, and androgen pathways through modulation of stochastic cell behaviors, including differential adhesion, motility, proliferation, and apoptosis. Proper urethral tube closure in the model was shown to depend quantitatively on SHH- and FGF10-induced effects on mesenchymal proliferation and epithelial apoptosis??both ultimately linked to androgen signaling. In the absence of androgen, GT development was feminized and with partial androgen deficiency, the model resolved with incomplete urethral tube closure, thereby providing an in silico platform for probabilistic prediction of hypospadias risk across c

Response of Human Prostate Cancer Cells to Mitoxantrone Treatment in Simulated Microgravity Environment

NASA Technical Reports Server (NTRS)

Zhang, Ye; Edwards, Christopher; Wu, Honglu

2011-01-01

This study explores the changes in growth of human prostate cancer cells (LNCaP) and their response to the treatment of antineoplastic agent, mitoxantrone, under the simulated microgravity condition. In comparison to static 1g, microgravity and simulated microgravity have been shown to alter global gene expression patterns and protein levels in various cultured cell models or animals. However, very little is known about the effect of altered gravity on the responses of cells to drugs, especially chemotherapy drugs. To test the hypothesis that zero gravity would result in altered regulation of cells in response to antineoplastic agents, we cultured LNCaP cells for 96 hr either in a High Aspect Ratio Vessel (HARV) bioreactor at the rotating condition to model microgravity in space or in the static condition as a control. 24 hr after the culture started, mitoxantrone was introduced to the cells at a final concentration of 1 M. The mitoxantrone treatment lasted 72 hr and then the cells were collected for various measurements. Compared to static 1g controls, the cells cultured in the simulated microgravity environment did not show significant differences in cell viability, growth rate, or cell cycle distribution. However, in response to mitoxantrone (1uM), a significant proportion of bioreactor cultured cells (30%) was arrested at G2 phase and a significant number of these cells were apoptotic in comparison to their static controls. The expressions of 84 oxidative stress related genes were analyzed using Qiagen PCR array to identify the possible mechanism underlying the altered responses of bioreactor culture cells to mitoxantrone. Nine out of 84 genes showed higher expression at four hour post mitoxantrone treatment in cells cultured at rotating condition compared to those at static. Taken together, the results reported here indicate that simulated microgravity may alter the responses of LNCaP cells to mitoxantrone treatment. The alteration of oxidative stress pathways in cells cultured under simulated microgravity conditions may be one of the mechanisms to cause such changes of sensitivity of LNCaP cells to mitoxantrone treatment.

Exploring the Interaction Mechanism Between Cyclopeptide DC3 and Androgen Receptor Using Molecular Dynamics Simulations and Free Energy Calculations

PubMed Central

Zhang, Huimin; Song, Tianqing; Yang, Yizhao; Fu, Chenggong; Li, Jiazhong

2018-01-01

Androgen receptor (AR) is a key target in the discovery of anti-PCa (Prostate Cancer) drugs. Recently, a novel cyclopeptide Diffusa Cyclotide-3 (DC3), isolated from Hedyotisdiffusa, has been experimentally demonstrated to inhibit the survival and growth of LNCap cells, which typically express T877A-mutated AR, the most frequently detected point mutation of AR in castration-resistant prostate cancer (CRPC). But the interaction mechanism between DC3 and AR is not clear. Here in this study we aim to explore the possible binding mode of DC3 to T877A-mutated AR from molecular perspective. Firstly, homology modeling was employed to construct the three-dimensional structure of the cyclopeptide DC3 using 2kux.1.A as the template. Then molecular docking, molecular dynamics (MD) simulations, and molecular mechanics/generalized Born surface area (MM-GBSA) methods were performed to determine the bind site and explore the detailed interaction mechanism of DC3-AR complex. The obtained results suggested that the site formed by H11, loop888-893, and H12 (site 2) was the most possible position of DC3 binding to AR. Besides, hydrogen bonds, hydrophobic, and electrostatic interactions play dominant roles in the recognition and combination of DC3-AR complex. The essential residues dominant in each interaction were specifically revealed. This work facilitates our understanding of the interaction mechanism of DC3 binding to AR at the molecular level and contributes to the rational cyclopeptide drug design for prostate cancer. PMID:29755968

Exploring the Interaction Mechanism between Cyclopeptide DC3 and Androgen Receptor Using Molecular Dynamics Simulations and Free Energy Calculations

NASA Astrophysics Data System (ADS)

Zhang, Huimin; Song, Tianqing; Yang, Yizhao; Fu, Chenggong; Li, Jiazhong

2018-04-01

Androgen receptor (AR) is a key target in the discovery of anti-PCa (Prostate Cancer) drugs. Recently, a novel cyclopeptide Diffusa Cyclotide-3 (DC3), isolated from Hedyotisdiffusa, has been experimentally demonstrated to inhibit the survival and growth of LNCap cells, which typically express T877A-mutated AR, the most frequently detected point mutation of AR in castration-resistant prostate cancer (CRPC). But the interaction mechanism between DC3 and AR is not clear. Here in this study we aim to explore the possible binding mode of DC3 to T877A-mutated AR from molecular perspective. Firstly, homology modeling was employed to construct the three-dimensional structure of the cyclopeptide DC3 using 2kux.1.A as the template. Then molecular docking, molecular dynamics (MD) simulations and molecular mechanics/generalized Born surface area (MM-GBSA) methods were performed to determine the bind site and explore the detailed interaction mechanism of DC3-AR complex. The obtained results suggested that the site formed by H11, loop888-893 and H12 (site 2) was the most possible position of DC3 binding to AR. Besides, hydrogen bonds, hydrophobic and electrostatic interactions play dominant roles in the recognition and combination of DC3-AR complex. The essential residues dominant in each interaction were specifically revealed. This work facilitates our understanding of the interaction mechanism of DC3 binding to AR at the molecular level and contributes to the rational cyclopeptide drug design for prostate cancer.

Exploring the Interaction Mechanism Between Cyclopeptide DC3 and Androgen Receptor Using Molecular Dynamics Simulations and Free Energy Calculations.

PubMed

Zhang, Huimin; Song, Tianqing; Yang, Yizhao; Fu, Chenggong; Li, Jiazhong

2018-01-01

Androgen receptor (AR) is a key target in the discovery of anti-PCa (Prostate Cancer) drugs. Recently, a novel cyclopeptide Diffusa Cyclotide-3 (DC3), isolated from Hedyotisdiffusa , has been experimentally demonstrated to inhibit the survival and growth of LNCap cells, which typically express T877A-mutated AR, the most frequently detected point mutation of AR in castration-resistant prostate cancer (CRPC). But the interaction mechanism between DC3 and AR is not clear. Here in this study we aim to explore the possible binding mode of DC3 to T877A-mutated AR from molecular perspective. Firstly, homology modeling was employed to construct the three-dimensional structure of the cyclopeptide DC3 using 2kux.1.A as the template. Then molecular docking, molecular dynamics (MD) simulations, and molecular mechanics/generalized Born surface area (MM-GBSA) methods were performed to determine the bind site and explore the detailed interaction mechanism of DC3-AR complex. The obtained results suggested that the site formed by H11, loop888-893, and H12 (site 2) was the most possible position of DC3 binding to AR. Besides, hydrogen bonds, hydrophobic, and electrostatic interactions play dominant roles in the recognition and combination of DC3-AR complex. The essential residues dominant in each interaction were specifically revealed. This work facilitates our understanding of the interaction mechanism of DC3 binding to AR at the molecular level and contributes to the rational cyclopeptide drug design for prostate cancer.

Resveratrol Reduces Steroidogenesis in Rat Ovarian Theca-Interstitial Cells: The Role of Inhibition of Akt/PKB Signaling Pathway

PubMed Central

Ortega, Israel; Villanueva, Jesus A.; Wong, Donna H.; Cress, Amanda B.; Sokalska, Anna; Stanley, Scott D.

2012-01-01

Polycystic ovary syndrome is characterized by theca-interstitial hyperplasia and increased expression of steroidogenic genes, leading to excessive androgen production. Resveratrol, a natural polyphenol, promotes apoptosis and reduces rat theca-interstitial cell growth, in part by inhibiting the mevalonate pathway and decreasing the availability of substrates of isoprenylation [farnesyl-pyrophosphate (FPP) and geranylgeranyl-pyrophosphate (GGPP)]. This study evaluated the effect of resveratrol on rat theca-interstitial cell steroidogenesis. Because resveratrol may activate sirtuins, this study also investigated whether steroidogenesis was affected by sirtuin inhibitors (nicotinamide, sirtinol). Theca-interstitial cells were cultured with or without resveratrol (1–10 μm), GGPP (30 μm), FPP (30 μm), nicotinamide (1 mm), and/or sirtinol (10 μm). Resveratrol did not affect progesterone levels but reduced androgen production in a concentration-dependent fashion (androstenedione by up to 78% and androsterone by up to 76%). This inhibitory effect correlated with a decrease in mRNA expression of genes regulating androgen production, especially Cyp17a1 (by up to 73%). GGPP and FPP had no effect on androgen levels and Cyp17a1 mRNA levels and did not alter the effects induced by resveratrol. Similarly, sirtuin inhibitors did not reverse resveratrol-induced inhibition of steroidogenesis. However, resveratrol decreased activity of serine-threonine kinase/protein kinase B pathway, a cell-signaling pathway involved in ovarian steroidogenesis. The present findings indicate that resveratrol reduces androgen production primarily by inhibiting Cyp17a1 mRNA expression, and this inhibition may be mediated, in part, by blocking the activity of the serine-threonine kinase/protein kinase B pathway. These findings may be of clinical relevance to conditions associated with excessive production of androgens by theca cells, such as polycystic ovary syndrome. PMID:22719052

Genomic and non-genomic effects of androgens in the cardiovascular system: clinical implications

PubMed Central

Lucas-Herald, Angela K.; Alves-Lopes, Rheure; Montezano, Augusto C.; Ahmed, S. Faisal

2017-01-01

The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca2+ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function. PMID:28645930

The androgen receptor controls expression of the cancer-associated sTn antigen and cell adhesion through induction of ST6GalNAc1 in prostate cancer

PubMed Central

Munkley, Jennifer; Oltean, Sebastian; Vodák, Daniel; Wilson, Brian T.; Livermore, Karen E.; Zhou, Yan; Star, Eleanor; Floros, Vasileios I.; Johannessen, Bjarne; Knight, Bridget; McCullagh, Paul; McGrath, John; Crundwell, Malcolm; Skotheim, Rolf I.; Robson, Craig N.; Leung, Hing Y.; Harries, Lorna W.; Rajan, Prabhakar; Mills, Ian G.; Elliott, David J.

2015-01-01

Patterns of glycosylation are important in cancer, but the molecular mechanisms that drive changes are often poorly understood. The androgen receptor drives prostate cancer (PCa) development and progression to lethal metastatic castration-resistant disease. Here we used RNA-Seq coupled with bioinformatic analyses of androgen-receptor (AR) binding sites and clinical PCa expression array data to identify ST6GalNAc1 as a direct and rapidly activated target gene of the AR in PCa cells. ST6GalNAc1 encodes a sialytransferase that catalyses formation of the cancer-associated sialyl-Tn antigen (sTn), which we find is also induced by androgen exposure. Androgens induce expression of a novel splice variant of the ST6GalNAc1 protein in PCa cells. This splice variant encodes a shorter protein isoform that is still fully functional as a sialyltransferase and able to induce expression of the sTn-antigen. Surprisingly, given its high expression in tumours, stable expression of ST6GalNAc1 in PCa cells reduced formation of stable tumours in mice, reduced cell adhesion and induced a switch towards a more mesenchymal-like cell phenotype in vitro. ST6GalNAc1 has a dynamic expression pattern in clinical datasets, being significantly up-regulated in primary prostate carcinoma but relatively down-regulated in established metastatic tissue. ST6GalNAc1 is frequently upregulated concurrently with another important glycosylation enzyme GCNT1 previously associated with prostate cancer progression and implicated in Sialyl Lewis X antigen synthesis. Together our data establishes an androgen-dependent mechanism for sTn antigen expression in PCa, and are consistent with a general role for the androgen receptor in driving important coordinate changes to the glycoproteome during PCa progression. PMID:26452038

Tocotrienol-rich fraction of palm oil induces cell cycle arrest and apoptosis selectively in human prostate cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, Janmejai K.; Department of Urology, University Hospitals of Cleveland, Cleveland, OH 44106; Gupta, Sanjay

2006-07-28

One of the requisite of cancer chemopreventive agent is elimination of damaged or malignant cells through cell cycle inhibition or induction of apoptosis without affecting normal cells. In this study, employing normal human prostate epithelial cells (PrEC), virally transformed normal human prostate epithelial cells (PZ-HPV-7), and human prostate cancer cells (LNCaP, DU145, and PC-3), we evaluated the growth-inhibitory and apoptotic effects of tocotrienol-rich fraction (TRF) extracted from palm oil. TRF treatment to PrEC and PZ-HPV-7 resulted in almost identical growth-inhibitory responses of low magnitude. In sharp contrast, TRF treatment resulted in significant decreases in cell viability and colony formation inmore » all three prostate cancer cell lines. The IC{sub 5} values after 24 h TRF treatment in LNCaP, PC-3, and DU145 cells were in the order 16.5, 17.5, and 22.0 {mu}g/ml. TRF treatment resulted in significant apoptosis in all the cell lines as evident from (i) DNA fragmentation (ii) fluorescence microscopy, and (iii) cell death detection ELISA, whereas the PrEC and PZ-HPV-7 cells did not undergo apoptosis, but showed modestly decreased cell viability only at a high dose of 80 {mu}g/ml. In cell cycle analysis, TRF (10-40 {mu}g/ml) resulted in a dose-dependent G0/G1 phase arrest and sub G1 accumulation in all three cancer cell lines but not in PZ-HPV-7 cells. These results suggest that the palm oil derivative TRF is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. TRF offers significant promise as a chemopreventive and/or therapeutic agent against prostate cancer.« less

Selective inhibition of histone deacetylase 6 (HDAC6) induces DNA damage and sensitizes transformed cells to anticancer agents.

PubMed

Namdar, Mandana; Perez, Gisela; Ngo, Lang; Marks, Paul A

2010-11-16

Histone deacetylase 6 (HDAC6) is structurally and functionally unique among the 11 human zinc-dependent histone deacetylases. Here we show that chemical inhibition with the HDAC6-selective inhibitor tubacin significantly enhances cell death induced by the topoisomerase II inhibitors etoposide and doxorubicin and the pan-HDAC inhibitor SAHA (vorinostat) in transformed cells (LNCaP, MCF-7), an effect not observed in normal cells (human foreskin fibroblast cells). The inactive analogue of tubacin, nil-tubacin, does not sensitize transformed cells to these anticancer agents. Further, we show that down-regulation of HDAC6 expression by shRNA in LNCaP cells enhances cell death induced by etoposide, doxorubicin, and SAHA. Tubacin in combination with SAHA or etoposide is more potent than either drug alone in activating the intrinsic apoptotic pathway in transformed cells, as evidenced by an increase in PARP cleavage and partial inhibition of this effect by the pan-caspase inhibitor Z-VAD-fmk. HDAC6 inhibition with tubacin induces the accumulation of γH2AX, an early marker of DNA double-strand breaks. Tubacin enhances DNA damage induced by etoposide or SAHA as indicated by increased accumulation of γH2AX and activation of the checkpoint kinase Chk2. Tubacin induces the expression of DDIT3 (CHOP/GADD153), a transcription factor up-regulated in response to cellular stress. DDIT3 induction is further increased when tubacin is combined with SAHA. These findings point to mechanisms by which HDAC6-selective inhibition can enhance the efficacy of certain anti-cancer agents in transformed cells.

EphA2 enhances the proliferation and invasion ability of LNCaP prostate cancer cells

PubMed Central

CHEN, PEIJIE; HUANG, YAN; ZHANG, BO; WANG, QIUQUAN; BAI, PEIMING

2014-01-01

EphA2 is persistently overexpressed and functionally changed in numerous human cancers. However, to the best of our knowledge, the role that EphA2 plays in prostate cancer is not entirely clear. To investigate the roles of EphA2 in the development and progression of prostate cancer, the present study initially evaluated the roles of the EphA2 protein in LNCaP prostate cancer cells using recombinant plasmid, western blot analysis, flow cytometry, Matrigel invasion chamber and the cell counting kit-8 assay. An immunohistochemistry assay was also conducted to observe the effects of EphA2 in prostate cancer tissues. The results demonstrated that the LNCaP human prostate cancer cells that were transfected with pcDNA3.1(+) plasmid-mediated pcDNA3.1(+)-EphA2, markedly enhanced the cell growth and invasion in vitro. Additionally, EphA2 was overexpressed in prostate cancer specimens and the expression of EphA2 was significantly associated with Gleason grade, total prostate-specific antigen, advanced clinical stage and lymph node metastasis. Collectively, these results demonstrate that EphA2 is involved in malignant cell behavior and is a potential therapeutic target in human prostate cancer. PMID:24959216

Clinical significance of CXCL16/CXCR6 expression in patients with prostate cancer.

PubMed

Ha, Hong Koo; Lee, Wan; Park, Hyun Jun; Lee, Sang Don; Lee, Jeong Zoo; Chung, Moon Kee

2011-01-01

We hypothesized that the CXCL16-CXCR6 ligand-receptor system may play an important role in prostate cancer progression. Levels of CXCL16 and CXCR6 expression were evaluated in prostate cancer cell lines (PC-3 and LNCaP) and normal prostate epithelial cells (PrEC), as well as in tissues from 354 patients. The immunohistochemical expression of CXCL16/CXCR6 was greater in the PC-3/LNCaP cells than in the PrEC cell line. The expression of CXCL16/CXCR6 was significantly higher in prostate cancer than in benign prostatic hypertrophy. Using RT-PCR, the expression of CXCL16/CXCR6 was found to be greater in the PC-3/LNCaP cells than in the PrEC cell line. CXCL16/CXCR6 was weakly detected in lung and liver tissues, whereas CXCL16 was highly expressed in specimens of bone metastasis. CXCL16 immunostaining was related to Gleason score, T stage, tumor volume, perineural invasion and lymph node metastasis. However, biochemical PSA recurrence was not related to the expression of CXCL16/CXCR6. High CXCL16/CXCR6 expression may be related to aggressive cancer behavior, and high CXCL16 expression to bone metastases.

High activity of mitochondrial glycerophosphate dehydrogenase and glycerophosphate-dependent ROS production in prostate cancer cell lines.

PubMed

Chowdhury, Subir K R; Gemin, Adam; Singh, Gurmit

2005-08-12

Most malignant cells are highly glycolytic and produce high levels of reactive oxygen species (ROS) compared to normal cells. Mitochondrial glycerophosphate dehydrogenase (mGPDH) participates in the reoxidation of cytosolic NADH by delivering reducing equivalents from this molecule into the electron transport chain, thus sustaining glycolysis. Here, we investigate the role of mGPDH in maintaining an increased rate of glycolysis and evaluate glycerophosphate-dependent ROS production in prostate cancer cell lines (LNCaP, DU145, PC3, and CL1). Immunoblot, polarographic, and spectrophotometric analyses revealed that mGPDH abundance and activity was significantly elevated in prostate cancer cell lines when compared to the normal prostate epithelial cell line PNT1A. Furthermore, both the glycolytic capacity and glycerophosphate-dependent ROS production was increased 1.68- to 4.44-fold and 5- to 7-fold, respectively, in prostate cancer cell lines when compared to PNT1A cells. Overall, these data demonstrate that mGPDH is involved in maintaining a high rate of glycolysis and is an important site of electron leakage leading to ROS production in prostate cancer cells.

Atypical fibrosarcomas derived from cutaneous ganglion cell-like cells in 2 domestic Djungarian hamsters (Phodopus sungorus).

PubMed

Kondo, Hirotaka; Onuma, Mamoru; Shibuya, Hisashi; Sato, Tsuneo; Abbott, Jeffrey R

2011-07-01

Androgen-dependent atypical fibromas are benign tumors derived from ganglion-cell-like cells that are particular to Djungarian hamsters (Phodopus sungorus). Masses excised from 2 hamsters were composed of pleomorphic ganglion cell-like cells supported by small to moderate amounts of collagenous matrix. Intracytoplasmic fibrils were present in silver-stained sections, and immunohistochemistry showed that the cells expressed vimentin, androgen receptor, and, in one case, estrogen receptor α. In contrast to previously reported atypical fibromas, these tumors had features of anaplasia and were locally invasive. We diagnosed the tumors as atypical fibrosarcomas and consider them an unusual malignant counterpart of atypical fibroma. Copyright 2011 by the American Association for Laboratory Animal Science

Her-2-neu expression and progression toward androgen independence in human prostate cancer.

PubMed

Signoretti, S; Montironi, R; Manola, J; Altimari, A; Tam, C; Bubley, G; Balk, S; Thomas, G; Kaplan, I; Hlatky, L; Hahnfeldt, P; Kantoff, P; Loda, M

2000-12-06

Human prostate cancers are initially androgen dependent but ultimately become androgen independent. Overexpression of the Her-2-neu receptor tyrosine kinase has been associated with the progression to androgen independence in prostate cancer cells. We examined the expression of Her-2-neu in normal and cancerous prostate tissues to assess its role in the progression to androgen independence. Prostate cancer tissue sections were obtained from 67 patients treated by surgery alone (UNT tumors), 34 patients treated with total androgen ablation therapy before surgery (TAA tumors), and 18 patients in whom total androgen ablation therapy failed and who developed bone metastases (androgen-independent [AI] disease). The sections were immunostained for Her-2-neu, androgen receptor (AR), prostate-specific antigen (PSA), and Ki-67 (a marker of cell proliferation) protein expression. Messenger RNA (mRNA) levels and gene amplification of Her-2-neu were examined by RNA in situ hybridization and fluorescent in situ hybridization(FISH), respectively, in a subset of 27 tumors (nine UNT, 11 TAA, and seven AI). All statistical tests were two-sided. Her-2-neu protein expression was statistically significantly higher in TAA tumors than in UNT tumors with the use of two different scoring methods (P =.008 and P =.002). The proportion of Her-2-neu-positive tumors increased from the UNT group (17 of 67) to the TAA group (20 of 34) to the AI group (14 of 18) (P<.001). When compared with UNT tumors, tumor cell proliferation was higher in AI tumors (P =.014) and lower in TAA tumors (P<.001). All tumors expressed AR and PSA proteins. Although Her-2-neu mRNA expression was high in TAA and AI tumors, no Her-2-neu gene amplification was detected by FISH in any of the tumor types. Her-2-neu expression appears to increase with progression to androgen independence. Thus, therapeutic targeting of this tyrosine kinase in prostate cancer may be warranted.

Resveratrol Reduces Prostate Cancer Growth and Metastasis by Inhibiting the Akt/MicroRNA-21 Pathway

PubMed Central

Sheth, Sandeep; Jajoo, Sarvesh; Kaur, Tejbeer; Mukherjea, Debashree; Sheehan, Kelly; Rybak, Leonard P.; Ramkumar, Vickram

2012-01-01

The consumption of foods containing resveratrol produces significant health benefits. Resveratrol inhibits cancer by reducing cell proliferation and metastasis and by inducing apoptosis. These actions could be explained by its ability to inhibit (ERK-1/2), Akt and suppressing the levels of estrogen and insulin growth factor -1 (IGF-1) receptor. How these processes are manifested into the antitumor actions of resveratrol is not clear. Using microarray studies, we show that resveratrol reduced the expression of various prostate-tumor associated microRNAs (miRs) including miR-21 in androgen-receptor negative and highly aggressive human prostate cancer cells, PC-3M-MM2. This effect of resveratrol was associated with reduced cell viability, migration and invasiveness. Additionally, resveratrol increased the expression of tumor suppressors, PDCD4 and maspin, which are negatively regulated by miR-21. Short interfering (si) RNA against PDCD4 attenuated resveratrol’s effect on prostate cancer cells, and similar effects were observed following over expression of miR-21 with pre-miR-21 oligonucleotides. PC-3M-MM2 cells also exhibited high levels of phospho-Akt (pAkt), which were reduced by both resveratrol and LY294002 (a PI3-kinase inhibitor). MiR-21 expression in these cells appeared to be dependent on Akt, as LY294002 reduced the levels of miR-21 along with a concurrent increase in PDCD4 expression. These in vitro findings were further corroborated in a severe combined immunodeficient (SCID) mouse xenograft model of prostate cancer. Oral administration of resveratrol not only inhibited the tumor growth but also decreased the incidence and number of metastatic lung lesions. These tumor- and metastatic-suppressive effects of resveratrol were associated with reduced miR-21 and pAkt, and elevated PDCD4 levels. Similar anti-tumor effects of resveratrol were observed in DU145 and LNCaP prostate cancer cells which were associated with suppression of Akt and PDCD4, but independent of miR-21.These data suggest that resveratrol’s anti-tumor actions in prostate cancer could be explained, in part, through inhibition of Akt/miR-21 signaling pathway. PMID:23272133

Modulation of Androgen Receptor Signaling in Hormonal Therapy-Resistant Prostate Cancer Cell Lines

PubMed Central

Marques, Rute B.; Dits, Natasja F.; Erkens-Schulze, Sigrun; van IJcken, Wilfred F. J.; van Weerden, Wytske M.; Jenster, Guido

2011-01-01

Background Prostate epithelial cells depend on androgens for survival and function. In (early) prostate cancer (PCa) androgens also regulate tumor growth, which is exploited by hormonal therapies in metastatic disease. The aim of the present study was to characterize the androgen receptor (AR) response in hormonal therapy-resistant PC346 cells and identify potential disease markers. Methodology/Principal Findings Human 19K oligoarrays were used to establish the androgen-regulated expression profile of androgen-responsive PC346C cells and its derivative therapy-resistant sublines: PC346DCC (vestigial AR levels), PC346Flu1 (AR overexpression) and PC346Flu2 (T877A AR mutation). In total, 107 transcripts were differentially-expressed in PC346C and derivatives after R1881 or hydroxyflutamide stimulations. The AR-regulated expression profiles reflected the AR modifications of respective therapy-resistant sublines: AR overexpression resulted in stronger and broader transcriptional response to R1881 stimulation, AR down-regulation correlated with deficient response of AR-target genes and the T877A mutation resulted in transcriptional response to both R1881 and hydroxyflutamide. This AR-target signature was linked to multiple publicly available cell line and tumor derived PCa databases, revealing that distinct functional clusters were differentially modulated during PCa progression. Differentiation and secretory functions were up-regulated in primary PCa but repressed in metastasis, whereas proliferation, cytoskeletal remodeling and adhesion were overexpressed in metastasis. Finally, the androgen-regulated genes ENDOD1, MCCC2 and ACSL3 were selected as potential disease markers for RT-PCR quantification in a distinct set of human prostate specimens. ENDOD1 and ACSL3 showed down-regulation in high-grade and metastatic PCa, while MCCC2 was overexpressed in low-grade PCa. Conclusions/Significance AR modifications altered the transcriptional response to (anti)androgens in therapy-resistant cells. Furthermore, selective down-regulation of genes involved in differentiation and up-regulation of genes promoting proliferation and invasion suggest a disturbed balance between the growth and differentiation functions of the AR pathway during PCa progression. These findings may have implications in the current treatment and development of novel therapeutical approaches for metastatic PCa. PMID:21829708

Cytotoxic Compounds from Brucea mollis

PubMed Central

Tung, Mai Hung Thanh; Đuc, Ho Viet; Huong, Tran Thu; Duong, Nguyen Thanh; Phuong, Do Thi; Thao, Do Thi; Tai, Bui Huu; Kim, Young Ho; Bach, Tran The; Cuong, Nguyen Manh

2013-01-01

Ten compounds, including soulameanone (1), isobruceine B (2), 9-methoxy-canthin-6-one (3), bruceolline F (4), niloticine (5), octatriacontan-1-ol (6), bombiprenone (7), α-tocopherol (8), inosine (9), and apigenin 7-O-β-D-glucopyranoside (10), were isolated from the leaves, stems, and roots of Brucea mollis Wall. ex Kurz. Their structures were determined using one-and two-dimensional NMR spectroscopy and mass spectrometry. All compounds were evaluated for their cytotoxic activity against KB (human carcinoma of the mouth), LU-1 (human lung adenocarcinoma), LNCaP (human prostate adeno-carcinoma), and HL-60 (human promyelocytic leukemia) cancer cell lines. Compound 2 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values of 0.39, 0.40, 0.34, and 0.23 μg/mL, respectively. In addition, compounds 3 and 5 showed significant cytotoxic activity against KB, LU-1, LNCaP, and HL-60 cancer cells with IC50 values around 1–4 μg/mL. Compounds 9-methoxycanthin-6-one (3) and niloticine (5) have been discovered for the first time from the Brucea genus. PMID:24106661

Muscle-specific androgen receptor deletion shows limited actions in myoblasts but not in myofibers in different muscles in vivo.

PubMed

Rana, Kesha; Chiu, Maria W S; Russell, Patricia K; Skinner, Jarrod P; Lee, Nicole K L; Fam, Barbara C; Zajac, Jeffrey D; MacLean, Helen E

2016-08-01

The aim of this study was to investigate the direct muscle cell-mediated actions of androgens by comparing two different mouse lines. The cre-loxP system was used to delete the DNA-binding activity of the androgen receptor (AR) in mature myofibers (MCK mAR(ΔZF2)) in one model and the DNA-binding activity of the AR in both proliferating myoblasts and myofibers (α-actin mAR(ΔZF2)) in another model. We found that hind-limb muscle mass was normal in MCK mAR(ΔZF2) mice and that relative mass of only some hind-limb muscles was reduced in α-actin mAR(ΔZF2) mice. This suggests that myoblasts and myofibers are not the major cellular targets mediating the anabolic actions of androgens on male muscle during growth and development. Levator ani muscle mass was decreased in both mouse lines, demonstrating that there is a myofiber-specific effect in this unique androgen-dependent muscle. We found that the pattern of expression of genes including c-myc, Fzd4 and Igf2 is associated with androgen-dependent changes in muscle mass; therefore, these genes are likely to be mediators of anabolic actions of androgens. Further research is required to identify the major targets of androgen actions in muscle, which are likely to include indirect actions via other tissues. © 2016 Society for Endocrinology.

The Bcl-2-Beclin 1 interaction in (-)-gossypol-induced autophagy versus apoptosis in prostate cancer cells.

PubMed

Lian, Jiqin; Karnak, David; Xu, Liang

2010-11-01

Bcl-2 is a key dual regulator of autophagy and apoptosis, but how the level of Bcl-2 influences the cellular decision between autophagy and apoptosis is unclear. The natural BH3-mimetic (-)-gossypol preferentially induces autophagy in androgen-independent (AI) prostate cancer cells that have high levels of Bcl-2 and are resistant to apoptosis, whereas apoptosis is preferentially induced in androgen-dependent or -independent cells with low Bcl-2. (-)-Gossypol induces autophagy via blocking Bcl-2-Beclin 1 interaction at the endoplasmic reticulum (ER), together with downregulating Bcl-2, upregulating Beclin 1 and activating the autophagic pathway. Furthermore, (-)-gossypol-induced autophagy is Beclin 1- and Atg5-dependent. These results provide new insights into the mode of cell death induced by Bcl-2 inhibitors, which could facilitate the rational design of clinical trials by selecting patients who are most likely to benefit from the Bcl-2-targeted molecular therapy.

Mangiferin inhibits tumor necrosis factor-α-induced matrix metalloproteinase-9 expression and cellular invasion by suppressing nuclear factor-κB activity

PubMed Central

Dilshara, Matharage Gayani; Kang, Chang-Hee; Choi, Yung Hyun; Kim, Gi-Young

2015-01-01

We investigated the effects of mangiferin on the expression and activity of metalloproteinase (MMP)-9 and the invasion of tumor necrosis factor (TNF)-α-stimulated human LNCaP prostate carcinoma cells. Reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that mangiferin significantly reversed TNF-α-induced mRNA and protein expression of MMP-9 expression. Zymography data confirmed that stimulation of cells with TNF-α significantly increased MMP-9 activity. However, mangiferin substantially reduced the TNF-α-induced activity of MMP-9. Additionally, a matrigel invasion assay showed that mangiferin significantly reduced TNF-α-induced invasion of LNCaP cells. Compared to untreated controls, TNF-α-stimulated LNCaP cells showed a significant increase in nuclear factor-κB (NF-κB) luciferase activity. However, mangiferin treatment markedly decreased TNF-α-induced NF-κB luciferase activity. Furthermore, mangiferin suppressed nuclear translocation of the NF-κB subunits p65 and p50. Collectively, our results indicate that mangiferin is a potential anti-invasive agent that acts by suppressing NF-κB-mediated MMP-9 expression. [BMB Reports 2015; 48(10): 559-564] PMID:25739392

Mangiferin inhibits tumor necrosis factor-α-induced matrix metalloproteinase-9 expression and cellular invasion by suppressing nuclear factor-κB activity.

PubMed

Dilshara, Matharage Gayani; Kang, Chang-Hee; Choi, Yung Hyun; Kim, Gi-Young

2015-10-01

We investigated the effects of mangiferin on the expression and activity of metalloproteinase (MMP)-9 and the invasion of tumor necrosis factor (TNF)-α-stimulated human LNCaP prostate carcinoma cells. Reverse-transcription polymerase chain reaction (RT-PCR) and western blot analysis showed that mangiferin significantly reversed TNF-α-induced mRNA and protein expression of MMP-9 expression. Zymography data confirmed that stimulation of cells with TNF-α significantly increased MMP-9 activity. However, mangiferin substantially reduced the TNF-α-induced activity of MMP-9. Additionally, a matrigel invasion assay showed that mangiferin significantly reduced TNF-α-induced invasion of LNCaP cells. Compared to untreated controls, TNF-α-stimulated LNCaP cells showed a significant increase in nuclear factor-κB (NF-κB) luciferase activity. However, mangiferin treatment markedly decreased TNF-α-induced NF-κB luciferase activity. Furthermore, mangiferin suppressed nuclear translocation of the NF-κB subunits p65 and p50. Collectively, our results indicate that mangiferin is a potential anti-invasive agent that acts by suppressing NF-κB-mediated MMP-9 expression.

Identification of beta-2 as a key cell adhesion molecule in PCa cell neurotropic behavior: a novel ex vivo and biophysical approach.

PubMed

Jansson, Keith H; Castillo, Deborah G; Morris, Joseph W; Boggs, Mary E; Czymmek, Kirk J; Adams, Elizabeth L; Schramm, Lawrence P; Sikes, Robert A

2014-01-01

Prostate cancer (PCa) is believed to metastasize through the blood/lymphatics systems; however, PCa may utilize the extensive innervation of the prostate for glandular egress. The interaction of PCa and its nerve fibers is observed in 80% of PCa and is termed perineural invasion (PNI). PCa cells have been observed traveling through the endoneurium of nerves, although the underlying mechanisms have not been elucidated. Voltage sensitive sodium channels (VSSC) are multimeric transmembrane protein complexes comprised of a pore-forming α subunit and one or two auxiliary beta (β) subunits with inherent cell adhesion molecule (CAM) functions. The beta-2 isoform (gene SCN2B) interacts with several neural CAMs, while interacting putatively with other prominent neural CAMs. Furthermore, beta-2 exhibits elevated mRNA and protein levels in highly metastatic and castrate-resistant PCa. When overexpressed in weakly aggressive LNCaP cells (2BECFP), beta-2 alters LNCaP cell morphology and enhances LNCaP cell metastasis associated behavior in vitro. We hypothesize that PCa cells use beta-2 as a CAM during PNI and subsequent PCa metastasis. The objective of this study was to determine the effect of beta-2 expression on PCa cell neurotropic metastasis associated behavior. We overexpressed beta-2 as a fusion protein with enhanced cyan fluorescence protein (ECFP) in weakly aggressive LNCaP cells and observed neurotropic effects utilizing our novel ex vivo organotypic spinal cord co-culture model, and performed functional assays with neural matrices and atomic force microscopy. With increased beta-2 expression, PCa cells display a trend of enhanced association with nerve axons. On laminin, a neural CAM, overexpression of beta-2 enhances PCa cell migration, invasion, and growth. 2BECFP cells exhibit marked binding affinity to laminin relative to LNECFP controls, and recombinant beta-2 ectodomain elicits more binding events to laminin than BSA control. Functional overexpression of VSSC beta subunits in PCa may mediate PCa metastatic behavior through association with neural matrices.

Lgr4 promotes prostate tumorigenesis through the Jmjd2a/AR signaling pathway.

PubMed

Zhang, Jianwei; Li, Qi; Zhang, Shaojin; Xu, Quanquan; Wang, Tianen

2016-11-15

Lgr4 (leucine-rich repeat domain containing G protein-coupled receptor 4) is implicated in the transcriptional regulation of multiple histone demethylases in the progression of diverse cancers, but there are few reports concerning the molecular mechanism by which Lgr4 regulates histone demethylase activation in prostate cancer (PCa) progression. As Jmjd2a is a histone demethylase, in the current study, we investigated the relationship between interaction Lgr4 with Jmjd 2a and Jmjd2a/androgen receptor (AR) signaling pathway in PCa progression. Firstly, Lgr4 was overexpressed by transfecting pcDNA3.1(+)/Lgr4 plasmids into PCa (LNCaP and PC-3) cell lines. Next, we found that Lgr4 overexpression promoted Jmjd2a mRNA expression, reduced cell apoptosis and arrested cell cycle in the S phase, these effects were reversed by Jmjd2a silencing. Moreover, Lgr4 overexpression markedly elevated AR levels and its interaction with Jmjd2a, which was tested by co-immunoprecipitation and luciferase reporter assays. Furthermore, interaction AR with PSA promoter (containing an AR response element) was obviously improved by Lgr4 overexpression, and PSA silencing reduced Lgr4-induced cell apoptosis and cell cycle arrest in PCa cells. Taken together, Lgr4 may be a novel tumor marker providing new mechanistic insights into PCa progression. Lgr4 activates Jmjd2a/AR signaling pathway to promote interaction AR with PSA promoter, causing reduction of PCa apoptosis and cell cycle arrest. Copyright © 2016 Elsevier Inc. All rights reserved.

Mitofusin 1 degradation is induced by a disruptor of mitochondrial calcium homeostasis, CGP37157: a role in apoptosis in prostate cancer cells.

PubMed

Choudhary, Vivek; Kaddour-Djebbar, Ismail; Alaisami, Rabei; Kumar, M Vijay; Bollag, Wendy B

2014-05-01

Mitochondria constantly divide (mitochondrial fission) and fuse (mitochondrial fusion) in a normal cell. Disturbances in the balance between these two physiological processes may lead to cell dysfunction or to cell death. Induction of cell death is the prime goal of prostate cancer chemotherapy. Our previous study demonstrated that androgens increase the expression of a mitochondrial protein involved in fission and facilitate an apoptotic response to CGP37157 (CGP), an inhibitor of mitochondrial calcium efflux, in prostate cancer cells. However, the regulation and role of mitochondrial fusion proteins in the death of these cells have not been examined. Therefore, our objective was to investigate the effect of CGP on a key mitochondrial fusion protein, mitofusin 1 (Mfn1), and the role of Mfn1 in prostate cancer cell apoptosis. We used various prostate cancer cell lines and western blot analysis, qRT-PCR, siRNA, M30 apoptosis assay and immunoprecipitation techniques to determine mechanisms regulating Mfn1. Treatment of prostate cancer cells with CGP resulted in selective degradation of Mfn1. Mfn1 ubiquitination was detected following immunoprecipitation of overexpressed Myc-tagged Mfn1 protein from CGP-treated cells, and treatment with the proteasomal inhibitor lactacystin, as well as siRNA-mediated knockdown of the E3 ubiquitin ligase March5, protected Mfn1 from CGP-induced degradation. These data indicate the involvement of the ubiquitin-proteasome pathway in CGP-induced degradation of Mfn1. We also demonstrated that downregulation of Mfn1 by siRNA enhanced the apoptotic response of LNCaP cells to CGP, suggesting a likely pro-survival role for Mfn1 in these cells. Our results suggest that manipulation of mitofusins may provide a novel therapeutic advantage in treating prostate cancer.

Nuclear factor erythroid 2-related factor-2 activity controls 4-hydroxynonenal metabolism and activity in prostate cancer cells.

PubMed

Pettazzoni, Piergiorgio; Ciamporcero, Eric; Medana, Claudio; Pizzimenti, Stefania; Dal Bello, Federica; Minero, Valerio Giacomo; Toaldo, Cristina; Minelli, Rosalba; Uchida, Koji; Dianzani, Mario Umberto; Pili, Roberto; Barrera, Giuseppina

2011-10-15

4-Hydroxynonenal (HNE) is an end product of lipoperoxidation with antiproliferative and proapoptotic properties in various tumors. Here we report a greater sensitivity to HNE in PC3 and LNCaP cells compared to DU145 cells. In contrast to PC3 and LNCaP cells, HNE-treated DU145 cells showed a smaller reduction in growth and did not undergo apoptosis. In DU145 cells, HNE did not induce ROS production and DNA damage and generated a lower amount of HNE-protein adducts. DU145 cells had a greater GSH and GST A4 content and GSH/GST-mediated HNE detoxification. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a regulator of the antioxidant response. Nrf2 protein content and nuclear accumulation were higher in DU145 cells compared to PC3 and LNCaP cells, whereas the expression of KEAP1, the main negative regulator of Nrf2 activity, was lower. Inhibition of Nrf2 expression with specific siRNA resulted in a reduction in GST A4 expression and GS-HNE formation, indicating that Nrf2 controls HNE metabolism. In addition, Nrf2 knockdown sensitized DU145 cells to HNE-mediated antiproliferative and proapoptotic activity. In conclusion, we demonstrated that increased Nrf2 activity resulted in a reduction in HNE sensitivity in prostate cancer cells, suggesting a potential mechanism of resistance to pro-oxidant therapy. Copyright © 2011 Elsevier Inc. All rights reserved.

Extracellular vesicles released by mesenchymal-like prostate carcinoma cells modulate EMT state of recipient epithelial-like carcinoma cells through regulation of AR signaling.

PubMed

El-Sayed, Ihsan Y; Daher, Ahmad; Destouches, Damien; Firlej, Virginie; Kostallari, Enis; Maillé, Pascale; Huet, Eric; Haidar-Ahmad, Nathaline; Jenster, Guido; de la Taille, Alexandre; Abou Merhi, Raghida; Terry, Stéphane; Vacherot, Francis

2017-12-01

Extracellular vesicles released from cancer cells may play an important role in cancer progression by shuttling oncogenic information into recipient cells. However, our knowledge is still fragmentary and there remain numerous questions regarding the mechanisms at play and the functional consequences of these interactions. We have recently established a mesenchymal-like prostate cancer cell line (22Rv1/CR-1; Mes-PCa). In this study, we assessed the effects of the extracellular vesicles released by these cells on recipient androgen-dependent epithelial VCaP prostate cancer cells. Mes-PCa derived vesicles were found to promote mesenchymal features in the recipient epithelial-like prostate cancer cells. This transformation was accompanied by a modulation of androgen receptor signaling and activation of TGFβ signaling pathway. Moreover, recipient cells acquiring mesenchymal traits displayed enhanced migratory and invasive features as well as increased resistance to the androgen receptor antagonist, enzalutamide. Our results suggest a previously unappreciated role for Mes-PCa secreted vesicles in cancer promotion by transferring cell-mediated signals and promoting phenotypic changes in recipient prostate cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

TGFβ1 alters androgenic metabolites and hydroxysteroid dehydrogenase enzyme expression in human prostate reactive stromal primary cells: Is steroid metabolism altered by prostate reactive stromal microenvironment?

PubMed Central

Piao, Yun-shang; Wiesenfeld, Paddy; Sprando, Robert; Arnold, Julia T.

2013-01-01

The inflammatory tissue microenvironment can be an active promoter in preneoplastic cancer lesions. Altered steroid hormone metabolism as induced by the inflammatory microenvironment may contribute to epithelial cancer progression. Dehydroepiandrosterone sulfate (DHEAS) is the most abundant endogenous steroid hormone present in human serum and can be metabolized to DHEA, androgens and/or estrogens in peripheral tissues. We have previously reported that TGFβ1-induced reactive prostate stromal cells increase DHEA metabolism to active androgens and alter prostate cancer cell gene expression. While much of the focus on mechanisms of prostate cancer and steroid metabolism is in the epithelial cancer cells, this study focuses on TGFβ1-induced effects on DHEA metabolic pathways and enzymes in human prostate stromal cells. In DHEA-treated primary prostate stromal cells, TGFβ1 produced time- and dose-dependent increases in metabolism of DHEA to androstenedione and testosterone. Also TGFβ1-treated prostate stromal cells exhibited changes in the gene expression of enzymes involved in steroid metabolism including up-regulation of 3β hydroxysteroid dehydrogenase (HSD), and down-regulation of 17βHSD5, and 17βHSD2. These studies suggest that reactive prostate stroma and the inflammatory microenvironment may contribute to altered steroid metabolism and increased intratumoral androgens. PMID:23770322

TGFβ1 alters androgenic metabolites and hydroxysteroid dehydrogenase enzyme expression in human prostate reactive stromal primary cells: Is steroid metabolism altered by prostate reactive stromal microenvironment?

PubMed

Piao, Yun-shang; Wiesenfeld, Paddy; Sprando, Robert; Arnold, Julia T

2013-11-01

The inflammatory tissue microenvironment can be an active promoter in preneoplastic cancer lesions. Altered steroid hormone metabolism as induced by the inflammatory microenvironment may contribute to epithelial cancer progression. Dehydroepiandrosterone sulfate (DHEAS) is the most abundant endogenous steroid hormone present in human serum and can be metabolized to DHEA, androgens and/or estrogens in peripheral tissues. We have previously reported that TGFβ1-induced reactive prostate stromal cells increase DHEA metabolism to active androgens and alter prostate cancer cell gene expression. While much of the focus on mechanisms of prostate cancer and steroid metabolism is in the epithelial cancer cells, this study focuses on TGFβ1-induced effects on DHEA metabolic pathways and enzymes in human prostate stromal cells. In DHEA-treated primary prostate stromal cells, TGFβ1 produced time- and dose-dependent increases in metabolism of DHEA to androstenedione and testosterone. Also TGFβ1-treated prostate stromal cells exhibited changes in the gene expression of enzymes involved in steroid metabolism including up-regulation of 3β hydroxysteroid dehydrogenase (HSD), and down-regulation of 17βHSD5, and 17βHSD2. These studies suggest that reactive prostate stroma and the inflammatory microenvironment may contribute to altered steroid metabolism and increased intratumoral androgens. Published by Elsevier Ltd.

Ultrasound-Guided Delivery of siRNA and a Chemotherapeutic Drug by Using Microbubble Complexes: In Vitro and In Vivo Evaluations in a Prostate Cancer Model.

PubMed

Bae, Yun Jung; Yoon, Young Il; Yoon, Tae-Jong; Lee, Hak Jong

2016-01-01

To evaluate the effectiveness of ultrasound and microbubble-liposome complex (MLC)-mediated delivery of siRNA and doxorubicin into prostate cancer cells and its therapeutic capabilities both in vitro and in vivo. Microbubble-liposome complexes conjugated with anti-human epidermal growth factor receptor type 2 (Her2) antibodies were developed to target human prostate cancer cell lines PC-3 and LNCaP. Intracellular delivery of MLC was observed by confocal microscopy. We loaded MLC with survivin-targeted small interfering RNA (siRNA) and doxorubicin, and delivered it into prostate cancer cells. The release of these agents was facilitated by ultrasound application. Cell viability was analyzed by MTT assay after the delivery of siRNA and doxorubicin. Survivin-targeted siRNA loaded MLC was delivered into the xenograft mouse tumor model. Western blotting was performed to quantify the expression of survivin in vivo. Confocal microscopy demonstrated substantial intracellular uptake of MLCs in LNCaP, which expresses higher levels of Her2 than PC-3. The viability of LNCaP cells was significantly reduced after the delivery of MLCs loaded with siRNA and doxorubicin (85.0 ± 2.9%), which was further potentiated by application of ultrasound (55.0 ± 3.5%, p = 0.009). Survivin expression was suppressed in vivo in LNCaP tumor xenograft model following the ultrasound and MLC-guided delivery of siRNA (77.4 ± 4.90% to 36.7 ± 1.34%, p = 0.027). Microbubble-liposome complex can effectively target prostate cancer cells, enabling intracellular delivery of the treatment agents with the use of ultrasound. Ultrasound and MLC-mediated delivery of survivin-targeted siRNA and doxorubicin can induce prostate cell apoptosis and block survivin expression in vitro and in vivo.

Regulation of the ITGA2 gene by epigenetic mechanisms in prostate cancer.

PubMed

Chin, Suyin Paulynn; Marthick, James R; West, Alison C; Short, Annabel K; Chuckowree, Jyoti; Polanowski, Andrea M; Thomson, Russell J; Holloway, Adele F; Dickinson, Joanne L

2015-05-01

Integrin alpha2 beta1 (α2 β1 ) plays an integral role in tumour cell invasion, metastasis and angiogenesis, and altered expression of the receptor has been linked to tumour prognosis in several solid tumours. However, the relationship is complex, with both increased and decreased expression associated with different stages of tumour metastases in several tumour types. The ITGA2 gene, which codes for the α2 subunit, was examined to investigate whether a large CpG island associated with its promoter region is involved in the differential expression of ITGA2 observed in prostate cancer. Bisulphite sequencing of the ITGA2 promoter was used to assess methylation in formalin-fixed paraffin-embedded (FFPE) prostate tumour specimens and prostate cancer cell lines, PC3, 22Rv1 and LNCaP. Changes in ITGA2 mRNA expression were measured using quantitative PCR. ITGA2 functionality was interrogated using cell migration scratch assays and siRNA knockdown experiments. Bisulphite sequencing revealed strikingly decreased methylation at key CpG sites within the promoter of tumour samples, when compared with normal prostate tissue. Altered methylation of this CpG island is also associated with differences in expression in the non-invasive LNCaP, and the highly metastatic PC3 and 22Rv1 prostate cancer cell lines. Further bisulphite sequencing confirmed that selected CpGs were highly methylated in LNCaP cells, whilst only low levels of methylation were observed in PC3 and 22Rv1 cells, correlating with ITGA2 transcript levels. Examination of the increased expression of ITGA2 was shown to influence migratory potential via scratch assay in PC3, 22Rv1 and LNCaP cells, and was confirmed by siRNA knockdown experiments. Taken together, our data supports the assertion that epigenetic modification of the ITGA2 promoter is a mechanism by which ITGA2 expression is regulated. © 2015 Wiley Periodicals, Inc.

Androgen Control of Cell Proliferation and Cytoskeletal Reorganization in Human Fibrosarcoma Cells

PubMed Central

Chauhan, Sanjay; Kunz, Susan; Davis, Kelli; Roberts, Jordan; Martin, Greg; Demetriou, Manolis C.; Sroka, Thomas C.; Cress, Anne E.; Miesfeld, Roger L.

2009-01-01

We recently generated an HT-1080-derived cell line called HT-AR1 that responds to dihydrotestosterone (DHT) treatment by undergoing cell growth arrest in association with cytoskeletal reorganization and induction of neuroendocrine-like cell differentiation. In this report, we show that DHT induces a dose-dependent increase in G0/G1 growth-arrested cells using physiological levels of hormone. The arrested cells increase in cell size and contain a dramatic redistribution of desmoplakin, keratin 5, and chromogranin A proteins. DHT-induced cytoskeletal changes were also apparent from time lapse video microscopy that showed that androgen treatment resulted in the rapid appearance of neuronal-like membrane extensions. Expression profiling analysis using RNA isolated from DHT-treated HT-AR1 cells revealed that androgen receptor activation leads to the coordinate expression of numerous cell signaling genes including RhoB, PTGF-β, caveolin-2, Egr-1, myosin 1B, and EHM2. Because RhoB has been shown to have a role in tumor suppression and neuronal differentiation in other cell types, we investigated RhoB signaling functions in the HT-AR1 steroid response. We found that steroid induction of RhoB was DHT-specific and that newly synthesized RhoB protein was post-translationally modified and localized to endocytic vesicles. Moreover, treatment with a farnesyl transferase inhibitor reduced DHT-dependent growth arrest, suggesting that prenylated RhoB might function to inhibit HT-AR1 cell proliferation. This was directly shown by transfecting HT-AR1 cells with RhoB coding sequences containing activating or dominant negative mutations. PMID:14576147

A novel histone deacetylase inhibitor, CG200745, potentiates anticancer effect of docetaxel in prostate cancer via decreasing Mcl-1 and Bcl-XL.

PubMed

Hwang, Jung Jin; Kim, Yong Sook; Kim, Taelim; Kim, Mi Joung; Jeong, In Gab; Lee, Je-Hwan; Choi, Jene; Jang, Sejin; Ro, Seonggu; Kim, Choung-Soo

2012-08-01

We synthesized a novel hydroxamate-based pan-histone deacetylase inhibitor (HDACI), CG200745 {(E)-2-(Naphthalen-1-yloxymethyl)-oct-2-enedioic acid 1-[(3-dimethylamino-propyl)-amide] 8-hydroxyamide]}. Like other inhibitors, for example vorinostat and belinostat, CG200745 has the hydroxamic acid moiety to bind zinc at the bottom of catalytic pocket. Firstly, we analyzed its inhibitory activity against histone deacetylase (HDAC) in hormone-dependent LNCaP cells and hormone-independent DU145 and PC3 cells. CG200745 inhibited deacetylation of histone H3 and tubulin as much as vorinostat and belinostat did. CG200745 also inhibited growth of prostate cancer cells, increased sub-G1 population, and activated caspase-9, -3 and -8 in LNCaP, DU145 and PC3 cells. These results indicate that CG200745 induces apoptosis. Next, we examined the effect of CG200745 on cell death induced by docetaxel in DU145 cells in vitro and in vivo. Compared to mono-treatment with each drug, pre-treatment of DU145 cells with docetaxel followed by CG200745 showed synergistic cytotoxicity, and increased the apoptotic sub-G1 population, caspase activation, and tubulin acetylation. Moreover, the combination treatment decreased Mcl-1 and Bcl-(XL). Docetaxel and CG200745 combination reduced tumor size in the DU145 xenograft model. These preclinical results show that combination treatment with docetaxel and new HDACI, CG200745, potentiated anti-tumor effect in hormone-refractory prostate cancer (HRPC) cells via activation of apoptosis.

Denhaminols A-H, dihydro-β-agarofurans from the endemic Australian rainforest plant Denhamia celastroides.

PubMed

Levrier, Claire; Sadowski, Martin C; Nelson, Colleen C; Healy, Peter C; Davis, Rohan A

2015-01-23

Eight new dihydro-β-agarofurans, denhaminols A-H (1-8), were isolated from the leaves of the Australian rainforest tree Denhamia celastroides. The chemical structures of 1-8 were elucidated following analysis of 1D/2D NMR and MS data. The absolute configuration of denhaminol A (1) was determined by single-crystal X-ray crystallography. All compounds were evaluated for cytotoxic activity against the human prostate cancer cell line LNCaP, using live-cell imaging and metabolic assays. Denhaminols A (1) and G (7) were also tested for their effects on the lipid content of LNCaP cells. This is the first report of secondary metabolites from D. celastroides.

Nonlinear system identification for prostate cancer and optimality of intermittent androgen suppression therapy.

PubMed

Suzuki, Taiji; Aihara, Kazuyuki

2013-09-01

These days prostate cancer is one of the most common types of malignant neoplasm in men. Androgen ablation therapy (hormone therapy) has been shown to be effective for advanced prostate cancer. However, continuous hormone therapy often causes recurrence. This results from the progression of androgen-dependent cancer cells to androgen-independent cancer cells during the continuous hormone therapy. One possible method to prevent the progression to the androgen-independent state is intermittent androgen suppression (IAS) therapy, which ceases dosing intermittently. In this paper, we propose two methods to estimate the dynamics of prostate cancer, and investigate the IAS therapy from the viewpoint of optimality. The two methods that we propose for dynamics estimation are a variational Bayesian method for a piecewise affine (PWA) system and a Gaussian process regression method. We apply the proposed methods to real clinical data and compare their predictive performances. Then, using the estimated dynamics of prostate cancer, we observe how prostate cancer behaves for various dosing schedules. It can be seen that the conventional IAS therapy is a way of imposing high cost for dosing while keeping the prostate cancer in a safe state. We would like to dedicate this paper to the memory of Professor Luigi M. Ricciardi. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Enrichment of prostate cancer stem cells from primary prostate cancer cultures of biopsy samples

PubMed Central

Wang, Shunqi; Huang, Shengsong; Zhao, Xin; Zhang, Qimin; Wu, Min; Sun, Feng; Han, Gang; Wu, Denglong

2014-01-01

This study was to enrich prostate cancer stem cells (PrCSC) from primary prostate cancer cultures (PPrCC). Primary prostate cancer cells were amplified in keratinocyte serum-free medium with epidermal growth factor (EGF) and bovine pituitary extract (BPE), supplemented with leukemia inhibitory factor (LIF), stem cell factor (SCF) and cholera toxin. After amplification, cells were transferred into ultra-low attachment dishes with serum-free DMEM/F12 medium, supplemented with EGF, basic fibroblast growth factor (bFGF), bovine serum albumin (BSA), insulin, and N2 nutrition. Expression of cell-type-specific markers was determined by RT-qPCR and immunostaining. Tumorigenicity of enriched PrCSC was determined by soft agar assay and xenograft assay in NOD/SCID mice. Biopsy samples from 19 confirmed prostate cancer patients were used for establishing PPrCC, and 18 cases (95%) succeeded. Both basal marker (CK5) and luminal markers (androgen receptor and CK8) strongly co-expressed in most of PPrCC, indicating their basal epithelial origin. After amplification under adherent culture condition in vitro, transient amplifying cells were the dominant cells. Sphere formation efficiency (SFE) of passaged PPrCC was about 0.5%, which was 27 times lower than SFE of LNCaP (13.67%) in the same condition. Compared with adherent cells from PPrCC, prostasphere from PPrCC showed up regulated stem cell markers and increased tumorigenic potential in soft-agar assay. However, spheroid cells from PPrCC prostasphere failed to initiate tumor in xenograft assay in 6 months. Thus, PPrCC can be established and amplified from prostate cancer biopsy samples. Our modified sphere culture system can enrich PrCSC from PPrCC. PMID:24427338

TATA-binding protein-associated factor 7 regulates polyamine transport activity and polyamine analog-induced apoptosis.

PubMed

Fukuchi, Junichi; Hiipakka, Richard A; Kokontis, John M; Nishimura, Kazuhiro; Igarashi, Kazuei; Liao, Shutsung

2004-07-16

Identification of the polyamine transporter gene will be useful for modulating polyamine accumulation in cells and should be a good target for controlling cell proliferation. Polyamine transport activity in mammalian cells is critical for accumulation of the polyamine analog methylglyoxal bis(guanylhydrazone) (MGBG) that induces apoptosis, although a gene responsible for transport activity has not been identified. Using a retroviral gene trap screen, we generated MGBG-resistant Chinese hamster ovary (CHO) cells to identify genes involved in polyamine transport activity. One gene identified by the method encodes TATA-binding protein-associated factor 7 (TAF7), which functions not only as one of the TAFs, but also a coactivator for c-Jun. TAF7-deficient cells had decreased capacity for polyamine uptake (20% of CHO cells), decreased AP-1 activation, as well as resistance to MGBG-induced apoptosis. Stable expression of TAF7 in TAF7-deficient cells restored transport activity (55% of CHO cells), AP-1 gene transactivation (100% of CHO cells), and sensitivity to MGBG-induced apoptosis. Overexpression of TAF7 in CHO cells did not increase transport activity, suggesting that TAF7 may be involved in the maintenance of basal activity. c-Jun NH2-terminal kinase inhibitors blocked MGBG-induced apoptosis without alteration of polyamine transport. Decreased TAF7 expression, by RNA interference, in androgen-independent human prostate cancer LN-CaP104-R1 cells resulted in lower polyamine transport activity (25% of control) and resistance to MGBG-induced growth arrest. Taken together, these results reveal a physiological function of TAF7 as a basal regulator for mammalian polyamine transport activity and MGBG-induced apoptosis.

Growth inhibitory effects of the dual ErbB1/ErbB2 tyrosine kinase inhibitor PKI-166 on human prostate cancer xenografts.

PubMed

Mellinghoff, Ingo K; Tran, Chris; Sawyers, Charles L

2002-09-15

Experiments with human prostate cancer cell lines have shown that forced overexpression of the ErbB2-receptor tyrosine kinase (RTK) promotes androgen-independent growth and increases androgen receptor-transcriptional activity in a ligand-independent fashion. To investigate the relationship between ErbB-RTK signaling and androgen in genetically unmanipulated human prostate cancer, we performed biochemical and biological studies with the dual ErbB1/ErbB2 RTK inhibitor PKI-166 using human prostate cancer xenograft models with isogenic sublines reflecting the transition from androgen-dependent to androgen-independent growth. In the presence of low androgen concentrations, PKI-166 showed profound growth-inhibitory effects on tumor growth, which could be partially reversed by androgen add-back. At physiological androgen concentrations, androgen withdrawal greatly enhanced the ability of PKI-166 to retard tumor growth. The level of extracellular signal-regulated kinase activation correlated with the response to PKI-166 treatment, whereas the expression levels of ErbB1 and ErbB2 did not. These results suggest that ErbB1/ErbB2 RTKs play an important role in the biology of androgen-independent prostate cancer and provide a rationale for clinical evaluation of inhibitors targeted to this pathway.

Ligand-independent activation of EphA2 by arachidonic acid induces metastasis-like behaviour in prostate cancer cells

PubMed Central

Tawadros, T; Brown, M D; Hart, C A; Clarke, N W

2012-01-01

Background: High intake of omega-6 polyunsaturated fatty acids (PUFA) has been associated with clinical progression in prostate cancer (CaP). This study investigates the signalling mechanism by which the omega-6 PUFA arachidonic acid (AA) induces prostatic cellular migration to bone marrow stroma. Methods: Western blot analysis of the PC-3, PC3-GFP, DU 145 and LNCaP cells or their lipid raft (LR) components post AA stimulation was conducted in association with assays for adhesion and invasion through the bone marrow endothelial monolayers. Results: Arachidonic acid increased transendothelial migration of PC3-GFP cells (adhesion 37%±0.08, P=0.0124; transmigration 270%±0.145, P=0.0008). Akt, Src and focal adhesion kinase (FAK) pathways were induced by AA and integrally involved in transendothelial migration. LR were critical in AA uptake and induced Akt activity. Ephrin receptor A2 (EphA2), localised in LR, is expressed in DU 145 and PC-3 cells. Arachidonic acid induced a rapid increase of EphA2 Akt-dependent/ligand-independent activation, while knockdown of the EphrinA1 ligand decreased AA induced transendothelial migration, with an associated decrease in Src and FAK activity. Arachidonic acid activated Akt in EphA2− LNCaP cells but failed to induce BMEC transendothelial invasion. Conclusion: Arachidonic acid induced stimulation of EphA2 in vitro is associated fundamentally with CaP epithelial migration across the endothelial barrier. PMID:23037715

Growth Inhibition by Testosterone in an Androgen Receptor Splice Variant-Driven Prostate Cancer Model.

PubMed

Nakata, Daisuke; Nakayama, Kazuhide; Masaki, Tsuneo; Tanaka, Akira; Kusaka, Masami; Watanabe, Tatsuya

2016-12-01

Castration resistance creates a significant problem in the treatment of prostate cancer. Constitutively active splice variants of androgen receptor (AR) have emerged as drivers for resistance to androgen deprivation therapy, including the next-generation androgen-AR axis inhibitors abiraterone and enzalutamide. In this study, we describe the characteristics of a novel castration-resistant prostate cancer (CRPC) model, designated JDCaP-hr (hormone refractory). JDCaP-hr was established from an androgen-dependent JDCaP xenograft model after surgical castration. The expression of AR and its splice variants in JDCaP-hr was evaluated by immunoblotting and quantitative reverse transcription-polymerase chain reaction. The effects of AR antagonists and testosterone on JDCaP-hr were evaluated in vivo and in vitro. The roles of full-length AR (AR-FL) and AR-V7 in JDCaP-hr cell growth were evaluated using RNA interference. JDCaP-hr acquired a C-terminally truncated AR protein during progression from the parental JDCaP. The expression of AR-FL and AR-V7 mRNA was upregulated by 10-fold in JDCaP-hr compared with that in JDCaP, indicating that the JDCaP and JDCaP-hr models simulate castration resistance with some clinical features, such as overexpression of AR and its splice variants. The AR antagonist bicalutamide did not affect JDCaP-hr xenograft growth, and importantly, testosterone induced tumor regression. In vitro analysis demonstrated that androgen-independent prostate-specific antigen secretion and cell proliferation of JDCaP-hr were predominantly mediated by AR-V7. JDCaP-hr cell growth displayed a bell-shaped dependence on testosterone, and it was suppressed by physiological concentrations of testosterone. Testosterone induced rapid downregulation of both AR-FL and AR-V7 expression at physiological concentrations and suppressed expression of the AR target gene KLK3. Our findings support the clinical value of testosterone therapy, including bipolar androgen therapy, in the treatment of AR-overexpressed CRPC driven by AR splice variants that are not clinically actionable at present. Prostate 76:1536-1545, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

14-3-3η Amplifies Androgen Receptor Actions in Prostate Cancer

PubMed Central

Titus, Mark A.; Tan, Jiann-an; Gregory, Christopher W.; Ford, O. Harris; Subramanian, Romesh R.; Fu, Haian; Wilson, Elizabeth M.; Mohler, James L.; French, Frank S.

2009-01-01

Purpose Androgen receptor (AR) abundance and AR-regulated gene expression in castration-recurrent prostate cancer (CaP) are indicative of AR activation in the absence of testicular androgen. AR transactivation of target genes in castration-recurrent CaP occurs in part through mitogen signaling that amplifies the actions of AR and its coregulators. Herein we report on the role of 14-3-3η in AR action. Experimental Design and Results AR and 14-3-3η co-localized in COS cell nuclei with and without androgen and 14-3-3η promoted AR nuclear localization in the absence of androgen. 14-3-3η interacted with AR in cell-free binding and coimmunoprecipitation assays. In the recurrent human CaP cell line, CWR-R1, native endogenous AR transcriptional activation was stimulated by 14-3-3η at low DHT concentrations and was increased by EGF. Moreover, the DHT and EGF dependent increase in AR transactivation was inhibited by a dominant negative 14-3-3η. In the CWR22 CaP xenograft model, 14-3-3η expression was increased by androgen, suggesting a feed-forward mechanism that potentiates both 14-3-3η and AR actions. 14-3-3η mRNA and protein decreased following castration of tumor bearing mice and increased in tumors of castrate mice after treatment with testosterone. CWR22 tumors that recurred 5 months after castration contained 14-3-3η levels similar to the androgen-stimulated tumors removed before castration. In a human prostate tissue microarray of clinical specimens, 14-3-3η localized with AR in nuclei and the similar amounts expressed in castration-recurrent CaP, androgen-stimulated CaP and benign prostatic hyperplasia were consistent with AR activation in recurrent CaP. Conclusion 14-3-3η enhances androgen and mitogen induced AR transcriptional activity in castration-recurrent CaP. PMID:19996220

Prenatal and adult androgen activities in alcohol dependence.

PubMed

Lenz, B; Mühle, C; Braun, B; Weinland, C; Bouna-Pyrrou, P; Behrens, J; Kubis, S; Mikolaiczik, K; Muschler, M-R; Saigali, S; Sibach, M; Tanovska, P; Huber, S E; Hoppe, U; Eichler, A; Heinrich, H; Moll, G H; Engel, A; Goecke, T W; Beckmann, M W; Fasching, P A; Müller, C P; Kornhuber, J

2017-07-01

Alcohol dependence is more prevalent in men than in women. The evidence for how prenatal and adult androgens influence alcohol dependence is limited. We investigated the effects of prenatal and adult androgen activity on alcohol dependence. Moreover, we studied how the behaviours of pregnant women affect their children's prenatal androgen load. We quantified prenatal androgen markers (e.g., second-to-fourth finger length ratio [2D : 4D]) and blood androgens in 200 early-abstinent alcohol-dependent in-patients and 240 controls (2013-2015, including a 12-month follow-up). We also surveyed 134 women during pregnancy (2005-2007) and measured the 2D : 4D of their children (2013-2016). The prenatal androgen loads were higher in the male alcohol-dependent patients compared to the controls (lower 2D : 4D, P = 0.004) and correlated positively with the patients' liver transaminase activities (P < 0.001) and alcohol withdrawal severity (P = 0.019). Higher prenatal androgen loads and increasing androgen levels during withdrawal predicted earlier and more frequent 12-month hospital readmission in alcohol-dependent patients (P < 0.005). Moreover, stress levels (P = 0.002), alcohol (P = 0.010) and tobacco consumption (P = 0.017), and lifetime stressors (P = 0.019) of women during pregnancy related positively to their children's prenatal androgen loads (lower 2D : 4D). Androgen activities in alcohol-dependent patients and behaviours of pregnant women represent novel preventive and therapeutic targets of alcohol dependence. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparison of steroid receptors from the androgen responsive DDT1 cell line and the nonresponsive HVP cell line.

PubMed

Norris, J S; Kohler, P O

1978-01-01

Two hamster cell lines have been isolated from androgen target tissue. The DDT1 cells derived from ductus deferens tissue exhibit a growth response to androgens, while the HVP cells derived from ventral prostate are androgen unresponsive. Both cell lines contain androgen receptors, that are similar when compared by kinetic methods, sedimentation velocity, chromatographic procedures or nuclear translocation ability. The forms of the high salt extracted nuclear receptors are indistinguishable chromatographically. Therefore, we postulate that the lesion preventing androgen induced growth in the HVP cell line is subseqent to nuclear translocation of the steroid receptor complex.

Genomic and non-genomic effects of androgens in the cardiovascular system: clinical implications.

PubMed

Lucas-Herald, Angela K; Alves-Lopes, Rheure; Montezano, Augusto C; Ahmed, S Faisal; Touyz, Rhian M

2017-07-01

The principle steroidal androgens are testosterone and its metabolite 5α-dihydrotestosterone (DHT), which is converted from testosterone by the enzyme 5α-reductase. Through the classic pathway with androgens crossing the plasma membrane and binding to the androgen receptor (AR) or via mechanisms independent of the ligand-dependent transactivation function of nuclear receptors, testosterone induces genomic and non-genomic effects respectively. AR is widely distributed in several tissues, including vascular endothelial and smooth muscle cells. Androgens are essential for many developmental and physiological processes, especially in male reproductive tissues. It is now clear that androgens have multiple actions besides sex differentiation and sexual maturation and that many physiological systems are influenced by androgens, including regulation of cardiovascular function [nitric oxide (NO) release, Ca 2+ mobilization, vascular apoptosis, hypertrophy, calcification, senescence and reactive oxygen species (ROS) generation]. This review focuses on evidence indicating that interplay between genomic and non-genomic actions of testosterone may influence cardiovascular function. © 2017 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

Stimulatory Effect of Insulin on 5α-Reductase Type 1 (SRD5A1) Expression through an Akt-Dependent Pathway in Ovarian Granulosa Cells

PubMed Central

Kayampilly, Pradeep P.; Wanamaker, Brett L.; Stewart, James A.; Wagner, Carrie L.; Menon, K. M. J.

2010-01-01

Elevated levels of 5α-reduced androgens have been shown to be associated with hyperandrogenism and hyperinsulinemia, the leading causes of ovulatory dysfunction in women. 5α-Dihydrotestosterone reduces ovarian granulosa cell proliferation by inhibiting FSH-mediated mitogenic signaling pathways. The present study examined the effect of insulin on 5α-reductase, the enzyme that catalyses the conversion of androgens to their 5α-derivatives. Granulosa cells isolated from immature rat ovaries were cultured in serum-free, phenol red-free DMEM-F12 media and treated with different doses of insulin (0, 0.1, 1.0, and 10.0 μg/ml) for different time intervals up to 12 h. The expression of 5α-reductase type 1 mRNA, the predominant isoform found in granulosa cells, showed a significant (P < 0.05) increase in response to the insulin treatment up to 12 h compared with control. The catalytic activity of 5α-reductase enzyme was also stimulated in a dose-depended manner (P < 0.05). Inhibiting the Akt-dependent signaling pathway abolished the insulin-mediated increase in 5α-reductase mRNA expression, whereas inhibition of the ERK-dependent pathway had no effect. The dose-dependent increase in 5α-reductase mRNA expression as well as catalytic activity seen in response to insulin treatment was also demonstrated in the human granulosa cell line (KGN). In addition to increased mRNA expression, a dose-dependent increase in 5α-reductase protein expression in response to insulin was also seen in KGN cells, which corroborated well with that of mRNA expression. These results suggest that elevated levels of 5α-reduced androgens seen in hyperinsulinemic conditions might be explained on the basis of a stimulatory effect of insulin on 5α-reductase in granulosa cells. The elevated levels of these metabolites, in turn, might adversely affect growth and proliferation of granulosa cells, thereby impairing follicle growth and ovulation. PMID:20810561

Exosomes confer pro-survival signals to alter the phenotype of prostate cells in their surrounding environment

PubMed Central

Hosseini-Beheshti, Elham; Choi, Wendy; Weiswald, Louis-Bastien; Kharmate, Geetanjali; Ghaffari, Mazyar; Roshan-Moniri, Mani; Hassona, Mohamed D.; Chan, Leslie; Chin, Mei Yieng; Tai, Isabella T.; Rennie, Paul S.; Fazli, Ladan; Guns, Emma S. Tomlinson

2016-01-01

Prostate cancer (PCa) is the most frequently diagnosed cancer in men. Current research on tumour-related extracellular vesicles (EVs) suggests that exosomes play a significant role in paracrine signaling pathways, thus potentially influencing cancer progression via multiple mechanisms. In fact, during the last decade numerous studies have revealed the role of EVs in the progression of various pathological conditions including cancer. Moreover, differences in the proteomic, lipidomic, and cholesterol content of exosomes derived from PCa cell lines versus benign prostate cell lines confirm that exosomes could be excellent biomarker candidates. As such, as part of an extensive proteomic analysis using LCMS we previously described a potential role of exosomes as biomarkers for PCa. Current evidence suggests that uptake of EV's into the local tumour microenvironment encouraging us to further examine the role of these vesicles in distinct mechanisms involved in the progression of PCa and castration resistant PCa. For the purpose of this study, we hypothesized that exosomes play a pivotal role in cell-cell communication in the local tumour microenvironment, conferring activation of numerous survival mechanisms during PCa progression and development of therapeutic resistance. Our in vitro results demonstrate that PCa derived exosomes significantly reduce apoptosis, increase cancer cell proliferation and induce cell migration in LNCaP and RWPE-1 cells. In conjunction with our in vitro findings, we have also demonstrated that exosomes increased tumor volume and serum PSA levels in vivo when xenograft bearing mice were administered DU145 cell derived exosomes intravenously. This research suggests that, regardless of androgen receptor phenotype, exosomes derived from PCa cells significantly enhance multiple mechanisms that contribute to PCa progression. PMID:26840259

Cdc20/p55 mediates the resistance to docetaxel in castration-resistant prostate cancer in a Bim-dependent manner.

PubMed

Wu, Fei; Lin, Yun; Cui, Peng; Li, Hongyun; Zhang, Lechao; Sun, Zeqiang; Huang, Shengliang; Li, Shun; Huang, Shiming; Zhao, Qingli; Liu, Qingyong

2018-06-01

At least to date, no effective treatment for advanced castration-resistant prostate cancer (CRPC) has been established. Recent studies indicated that cell division cycle 20 homolog (Cdc20) overexpression is associated with poor prognosis in patients with castration-resistant prostate cancer. However, the mechanism of Cdc20 in the development of docetaxel resistance in CRPC remains elusive. In this study, the transcription of Cdc20 was confirmed in three independent CRPC cell lines derived from different tissues, including LNCaP, PC3, and DU145. Docetaxel resistant (DR) cell lines were generated within the background of DU145 and PC3. The protein levels of Cdc20 and the biological phenotype were detected in both wild-type and DR cell lines. To further explore the mechanism of Cdc20 overexpression, stable cell lines with Cdc20 or Bcl-2 interacting mediator of cell death (Bim) deprivation were generated and examined for biological parameters. In addition, a specific Cdc20 inhibitor was used in DR cell lines to explore the potential solution for docetaxel resistant CRPC. Here, we identified Cdc20 is overexpressed in docetaxel resistant CRPC cell lines, including LNCaP, PC3, and DU145. We also reported that DR cell lines, which mimic the recurrent prostate cancer cells after docetaxel treatment, have higher levels of Cdc20 protein compared with the CRPC cell lines. Interestingly, the protein levels of Bim, an E3 ligase substrate of Cdc20, were decreased in DR cell lines compared with the wild-type, while the mRNA levels were similar. More importantly, in DR cell lines, the biological phenotype induced by Cdc20 deletion could be significantly reversed by the additional knockdown of Bim. As a result, docetaxel resistant prostate cancer cells treated with the pharmacological Cdc20 inhibitor became sensitive to docetaxel treatment. In conclusion, our data collectively demonstrated that Cdc20 overexpression facilitates the docetaxel resistant of the CRPC cell lines in a Bim-dependent manner. Furthermore, additionally targeting Cdc20 might be a promising solution for the treatment of the CRPC with docetaxel resistance.

CX4945 suppresses the growth of castration-resistant prostate cancer cells by reducing AR-V7 expression.

PubMed

Deng, Chuangzhong; Chen, Jieping; Guo, Shengjie; Wang, Yanjun; Zhou, Qianghua; Li, Zaishang; Yang, Xingping; Yu, Xingsu; Zhang, Zhenfeng; Zhou, Fangjian; Han, Hui; Yao, Kai

2017-08-01

The aberrant expression of casein kinase 2 (CK2) has been reported to be involved in the tumorigenesis and progression of prostate cancer. The inhibition of CK2 activity represses androgen-dependent prostate cancer cells by attenuating the androgen receptor (AR) signaling pathway. In this study, we examined the effect of CK2 inhibition in castration-resistant prostate cancer (CRPC) cells, in which AR variants (ARVs) play a predominant role. A newly synthetic CK2 selective inhibitor CX4945 was utilized to study the effect of CK2 inhibition in CRPC cells by CCK8 assay and colony formation assay. Protein and mRNA levels of full-length AR (AR-FL) and AR-V7 were determined by qPCR and western blot, respectively. The nuclear translocation of p50 and p65 was assessed to reflect the activity of the NF-κB pathway. CX4945 reduced the proliferation of CRPC cells in a dose-dependent and time-dependent manner. AR-V7 rather than AR-FL was downregulated by CX4945 in both the mRNA and protein level. Furthermore, CX4945 could restore the sensitivity of CRPC cells to bicalutamide. The analysis of possible mechanisms demonstrated that the inhibition of CK2 diminished the phosphorylation of p65 at ser529 and thus attenuated the activity of the NF-κB pathway. The inhibition of CK2 by CX4945 can repress the viability of CRPC cells and restore their sensitivity to anti-androgen therapy by suppressing AR-V7. This finding presents a potential option for the treatment of prostate cancer, especially CRPC.

Changes of Gene Expression in the Apoptosis Pathway in Lncap and PC3 Cells Exposed to X-Rays or Protons

NASA Technical Reports Server (NTRS)

Zhang, Ye; Rohde, Larry H.; Mehta, Satish K.; Pierson, Duane L.; Wu, Honglu

2009-01-01

Radio-resistant or recurrent prostate cancer represents a serious health risk for approximately 20%-30% of patients treated with primary radiation therapy for clinically localized prostate cancer. In our current studies, we investigated the expressions of apoptosis related gene expression profile (84 genes) in two distinct prostate cell lines Lncap (P53+ and AR+) and PC3 (P53- and AR-) before and after exposure to X-rays or protons, using cDNA PCR arrays. In Lncap cells, 10Gy X-ray radiation significantly induced the expression of 19 out of 84 genes at 4h after irradiation. The changed genes were mostly in death and death receptor domain families, TNF ligand and receptor families, and apoptotic group of the BCL2 family, especially in P53 related genes, such as FAS, BAX, BAK1 and GADD45A. In PC3, X-rays only induced the expression of 3 genes, including an increased expression of BIRC3. There was no difference of the X-ray mediated cell killing in both cell lines using the cell cycle analysis. However, these X-ray-induced gene expression differences between PC3 and Lncap may explain the phenotype of PC3 cells that shows more tolerant not only to radiation, but also to other apoptosis inducing and sensitizing reagents. To compare the effectiveness of cell killing with X-rays, we also exposed PC3 cells to 10Gy protons at the Bragg peak region. Protons did not induce more apoptosis than X-rays for the same dose. In comparison to X-rays, protons significantly altered expressions of 13 genes in PC3, which included decreased expressions of anti-apoptosis genes (BCL2 and BCL2L2), and increased expressions of death and death receptor domain family genes, TNF ligand and receptor family and several kinases (FAS, DAPK1 and RIPK2). These data suggest that proton treatment is more effective in influencing the apoptosis pathways in PC3 cells than X-rays, thus protons may be more effective in the treatment of specific prostate tumor.

Expression and localization of GLUT1 and GLUT12 in prostate carcinoma.

PubMed

Chandler, Jenalle D; Williams, Elizabeth D; Slavin, John L; Best, James D; Rogers, Suzanne

2003-04-15

Increased glucose consumption is a characteristic of malignant cells and in prostate carcinoma is associated with the proliferation of both androgen-dependent and independent cells. Transport of polar glucose across the nonpolar membrane relies on glucose transporter proteins, known as GLUTs. Increased expression of GLUT1 is a characteristic of many malignant cells. The authors characterized and cloned the cDNA for a novel glucose transporter, GLUT12, which was identified initially in malignant breast epithelial cells. To the authors' knowledge, there have been no reports on the expression of glucose transporters in the human prostate or human prostate carcinoma cells. The authors evaluated GLUT1 and GLUT12 expression in human prostate carcinoma cells. Reverse transcription-polymerase chain reaction was performed on total RNA extracted from cultured prostate carcinoma cells LNCaP, C4, C4-2, and C4-2B using primers to amplify GLUT1, GLUT12, or the housekeeping gene, 36B4. Total protein extracted from prostate carcinoma cell lines was assessed for GLUT12 protein by Western blot analysis. Cultured cell monolayers were incubated with antibodies to GLUT1 or GLUT12 and a peripheral Golgi protein, Golgi 58K, for detection by immunofluorescent confocal microscopy. Sections of benign prostatic hyperplasia and human prostate carcinoma were stained for immunohistochemical detection of GLUT1 and GLUT12. GLUT1 and GLUT12 mRNA and protein were detected in all cell lines evaluated. Immunofluorescence staining demonstrated both GLUT1 and GLUT12 on the plasma membrane and in the cytoplasm in all cultured prostate carcinoma cell lines, with GLUT1 but not GLUT12 appearing to colocalize with the Golgi. Immunohistochemical staining of benign prostatic hyperplasia indicated expression of GLUT1 but not GLUT12. Malignant tissue stained for GLUT12 but was negative for GLUT1. GLUT1 and GLUT12 are expressed in human prostate carcinoma cells. One possible rationale for the GLUT1 Golgi association is that it may supply glucose to the Golgi for byproduct incorporation into the prostatic secretory fluid. Further work will investigate the importance of glucose transport and GLUT1 and GLUT12 in prostate carcinoma cell growth. Copyright 2003 American Cancer Society.

miR-15a/miR-16 cluster inhibits invasion of prostate cancer cells by suppressing TGF-β signaling pathway.

PubMed

Jin, Wei; Chen, Fangjie; Wang, Kefeng; Song, Yan; Fei, Xiang; Wu, Bin

2018-05-23

To determine whether and how miR15a/16 regulate TGF-β signaling pathways during the progression of prostate cancer. We used bioinformatics prediction, reporter gene assay, real-time PCR, Matrigel invasion assay and Western blot to dissect the molecular mechanism of how miR-15a/miR-16 may cause metastasis in prostate tumor. MiR-15a/16 targeted and inhibited the expression of endogenous Smad3 and ACVR2A proteins. The overexpression of miR15a/16 down-regulated p-smad3 expression, affected the expression of both MMP2 and E-cadherin, and down-regulated the expression of the EMT-mediated factors Snail and Twist in LNCaP prostate cancer cells. The overexpression of miR15a/16 decreased the invasion of LNCaP cells. MiR-15a/miR-16 cluster could reverse the invasion of activin A-mediated prostate cancer cells. After the inhibition of the activin/smad signaling pathway, the inhibitory effect of invasion in prostate cancer cells by miR-15a/miR-16 cluster disappeared. Our data indicated that miR15a/16 inhibited the components of TGF-β signaling pathways in LNCaP cell line, which might relate to the progression and metastasis of prostate cancer. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Characterization of the oestrogenic activity of non-aromatic steroids: are there male-specific endogenous oestrogen receptor modulators?

PubMed Central

Wang, Pan; Wen, Yujing; Han, Gui-Zhen; Sidhu, Pritam Kaur; Zhu, Bao Ting

2009-01-01

Background and purpose: The endogenous oestrogens have important biological functions in men as well as in women. Because 17β-oestradiol and oestrone are also formed in the male body, these aromatic oestrogens are generally thought to be responsible for exerting the required oestrogenic functions in the male. In the present study, we tested the hypothesis that some of the non-aromatic steroids that are androgen precursors or metabolites with hydroxyl groups at C-3 and/or C-17 positions may also be able to serve as ligands for the oestrogen receptors (ER) in the male. Experimental approach: A total of sixty non-aromatic steroids (selected from families of androstens, androstans, androstadiens, oestrens and oestrans) were analysed for their ability to bind and activate the human ERα and ERβin vitro and in cultured cells. Key results: Six of the non-aromatic steroids, that is, 5-androsten-3β,17β-diol, 5α-androstan-3β,17β-diol, 5(10)-oestren-3α,17β-diol, 5(10)-oestren-3β,17β-diol, 4-oestren-3β,17β-diol and 5α-oestran-3β,17β-diol, were found to have physiologically relevant high binding affinity (∼50% of that of oestrone) for human ERα and ERβ. These non-aromatic steroids also activated the transcriptional activity of human ERs and elicited biological responses (such as growth stimulation) in two representative ER-positive human cancer cell lines (MCF-7 and LNCaP) with physiologically relevant potency and efficacy. Molecular docking analysis of these six active compounds showed that they could bind to ERα and ERβ in a manner similar to that of 17β-oestradiol. Conclusions and implications: These results provide evidence for the possibility that some of the endogenous androgen precursors or metabolites could serve as male-specific ER ligands. PMID:19888961

Human GH Receptor-IGF-1 Receptor Interaction: Implications for GH Signaling

PubMed Central

Gan, Yujun; Buckels, Ashiya; Liu, Ying; Zhang, Yue; Paterson, Andrew J.; Jiang, Jing; Zinn, Kurt R.

2014-01-01

GH signaling yields multiple anabolic and metabolic effects. GH binds the transmembrane GH receptor (GHR) to activate the intracellular GHR-associated tyrosine kinase, Janus kinase 2 (JAK2), and downstream signals, including signal transducer and activator of transcription 5 (STAT5) activation and IGF-1 gene expression. Some GH effects are partly mediated by GH-induced IGF-1 via IGF-1 receptor (IGF-1R), a tyrosine kinase receptor. We previously demonstrated in non-human cells that GH causes formation of a GHR-JAK2-IGF-1R complex and that presence of IGF-1R (even without IGF-1 binding) augments proximal GH signaling. In this study, we use human LNCaP prostate cancer cells as a model system to further study the IGF-1R's role in GH signaling. GH promoted JAK2 and GHR tyrosine phosphorylation and STAT5 activation in LNCaP cells. By coimmunoprecipitation and a new split luciferase complementation assay, we find that GH augments GHR/IGF-1R complex formation, which is inhibited by a Fab of an antagonistic anti-GHR monoclonal antibody. Short hairpin RNA-mediated IGF-1R silencing in LNCaP cells reduced GH-induced GHR, JAK2, and STAT5 phosphorylation. Similarly, a soluble IGF-1R extracellular domain fragment (sol IGF-1R) interacts with GHR in response to GH and blunts GH signaling. Sol IGF-1R also markedly inhibits GH-induced IGF-1 gene expression in both LNCaP cells and mouse primary osteoblast cells. On the basis of these and other findings, we propose a model in which IGF-1R augments GH signaling by allowing a putative IGF-1R-associated molecule that regulates GH signaling to access the activated GHR/JAK2 complex and envision sol IGF-1R as a dominant-negative inhibitor of this IGF-1R-mediated augmentation. Physiological implications of this new model are discussed. PMID:25211187

Developmental programming by androgen affects the circadian timing system in female mice.

PubMed

Mereness, Amanda L; Murphy, Zachary C; Sellix, Michael T

2015-04-01

Circadian clocks play essential roles in the timing of events in the mammalian hypothalamo-pituitary-ovarian (HPO) axis. The molecular oscillator driving these rhythms has been localized to tissues of the HPO axis. It has been suggested that synchrony among these oscillators is a feature of normal reproductive function. The impact of fertility disorders on clock function and the role of the clock in the etiology of endocrine pathology remain unknown. Polycystic ovarian syndrome (PCOS) is a particularly devastating fertility disorder, affecting 5%-10% of women at childbearing age with features including a polycystic ovary, anovulation, and elevated serum androgen. Approximately 40% of these women have metabolic syndrome, marked by hyperinsulinemia, dyslipidemia, and insulin resistance. It has been suggested that developmental exposure to excess androgen contributes to the etiology of fertility disorders, including PCOS. To better define the role of the timing system in these disorders, we determined the effects of androgen-dependent developmental programming on clock gene expression in tissues of the metabolic and HPO axes. Female PERIOD2::luciferase (PER2::LUC) mice were exposed to androgen (dihydrotestosterone [DHT]) in utero (Days 16-18 of gestation) or for 9-10 wk (DHT pellet) beginning at weaning (pubertal androgen excess [PAE]). As expected, both groups of androgen-treated mice had disrupted estrous cycles. Analysis of PER2::LUC expression in tissue explants revealed that excess androgen produced circadian misalignment via tissue-dependent effects on phase distribution. In vitro treatment with DHT differentially affected the period of PER2::LUC expression in tissue explants and granulosa cells, indicating that androgen has direct and tissue-specific effects on clock gene expression that may account for the effects of developmental programming on the timing system. © 2015 by the Society for the Study of Reproduction, Inc.

Plant Flavone Apigenin Binds to Nucleic Acid Bases and Reduces Oxidative DNA Damage in Prostate Epithelial Cells

PubMed Central

Bhaskaran, Natarajan; Gupta, Sanjay

2014-01-01

Oxidative stress has been linked to prostate carcinogenesis as human prostate tissue is vulnerable to oxidative DNA damage. Apigenin, a dietary plant flavone, possesses anti-proliferative and anticancer effects; however, its antioxidant properties have not been fully elucidated. We investigated sub-cellular distribution of apigenin, it’s binding to DNA and protective effects against H2O2-induced DNA damage using transformed human prostate epithelial RWPE-1 cells and prostate cancer LNCaP, PC-3 and DU145 cells. Exposure of cells to apigenin exhibited higher accumulation in RWPE-1 and LNCaP cells, compared to PC-3 and DU145 cells. The kinetics of apigenin uptake in LNCaP cells was estimated with a Km value of 5 µmole/L and Vmax of 190 pmoles/million cells/h. Sub-cellular fractionation demonstrated that nuclear matrix retains the highest concentration of apigenin (45.3%), followed by cytosol (23.9%), nuclear membranes (17.9%) and microsomes (12.9%), respectively. Spectroscopic analysis of apigenin with calf-thymus DNA exhibited intercalation as the dominant binding mode to DNA duplex. Apigenin exposure resulted in significant genoprotective effects in H2O2-stressed RWPE-1 cells by reduction in reactive oxygen species levels. In addition, apigenin exposure suppressed the formation of 8-hydroxy-2′ deoxyguanosine and protected exposed cells from apoptosis. Our studies demonstrate that apigenin is readily taken up by normal prostatic epithelial cells and prostate cancer cells, and is incorporated into their nuclei, where its intercalation with nucleic acid bases may account for its antioxidant and chemopreventive activities. PMID:24614817

Plant flavone apigenin binds to nucleic acid bases and reduces oxidative DNA damage in prostate epithelial cells.

PubMed

Sharma, Haripaul; Kanwal, Rajnee; Bhaskaran, Natarajan; Gupta, Sanjay

2014-01-01

Oxidative stress has been linked to prostate carcinogenesis as human prostate tissue is vulnerable to oxidative DNA damage. Apigenin, a dietary plant flavone, possesses anti-proliferative and anticancer effects; however, its antioxidant properties have not been fully elucidated. We investigated sub-cellular distribution of apigenin, it's binding to DNA and protective effects against H2O2-induced DNA damage using transformed human prostate epithelial RWPE-1 cells and prostate cancer LNCaP, PC-3 and DU145 cells. Exposure of cells to apigenin exhibited higher accumulation in RWPE-1 and LNCaP cells, compared to PC-3 and DU145 cells. The kinetics of apigenin uptake in LNCaP cells was estimated with a Km value of 5 µmole/L and Vmax of 190 pmoles/million cells/h. Sub-cellular fractionation demonstrated that nuclear matrix retains the highest concentration of apigenin (45.3%), followed by cytosol (23.9%), nuclear membranes (17.9%) and microsomes (12.9%), respectively. Spectroscopic analysis of apigenin with calf-thymus DNA exhibited intercalation as the dominant binding mode to DNA duplex. Apigenin exposure resulted in significant genoprotective effects in H2O2-stressed RWPE-1 cells by reduction in reactive oxygen species levels. In addition, apigenin exposure suppressed the formation of 8-hydroxy-2' deoxyguanosine and protected exposed cells from apoptosis. Our studies demonstrate that apigenin is readily taken up by normal prostatic epithelial cells and prostate cancer cells, and is incorporated into their nuclei, where its intercalation with nucleic acid bases may account for its antioxidant and chemopreventive activities.

Studies on the synergistic effect of androgen on the stimulation of progestin secretion by FSH in cultured rat granulosa cells: progesterone metabolism and the effect of androgens.

PubMed

Nimrod, A

1977-09-01

Metabolic transformations of progesterone in cultures of granulosa cells from immature hypophysectomized rats treated with diethylstilbestrol were studied in relation to the synergistic action of exogenous androgen and FSH on progestin (progesterone and 20alpha-dihydroprogesterone) accumulation. Androstenedione (Ad; 10 ng/ml) enhanced the sensitivity of rat granulosa cells to this steroidogenic action of FSH, lowering the threshold of the response from greater than 4 ng/ml (FSH alone) to 0.8 ng/ml in the presence of Ad. A synergistic effect with FSH was also shown by various 5alpha-androstane derivatives. They were, however, less effective than the parent delta4-3 keto androstenes. Progesterone underwent extensive 5alpha-reduction during culture, leading to accumulation of endogenous 5alpha-pregnane compounds, and to transformation of labelled progesterone into 5 alpha-reduced radiometabolites. These compounds corresponded in gas-liquid and thin-layer chromatographic behaviour to 3alpha-hydroxy-5alpha-pregnan-20-one, 20alpha-hydroxy-5alpha-pregnan-3-one and 5alpha-pregnane-3alpha,20alpha-diol. The rate of 5alpha-reduction of progestins was not affected by the presence of exogenous Ad (1 microgram/ml), ruling out the possibility that the effect of androgen on progestin accumulation depends on competitive inhibition of 5alpha-reductase. An involvement of androgen of thecal origin in the enhancement of the sensitivity of the FSH-responsive mechanism in granulosa cells is suggested.

Separation and dual detection of prostate cancer cells and protein biomarkers using a microchip device.

PubMed

Huang, Wanfeng; Chang, Chun-Li; Brault, Norman D; Gur, Onur; Wang, Zhe; Jalal, Shadia I; Low, Philip S; Ratliff, Timothy L; Pili, Roberto; Savran, Cagri A

2017-01-31

Current efforts for the detection of prostate cancer using only prostate specific antigen are not ideal and indicate a need to develop new assays - using multiple targets - that can more accurately stratify disease states. We previously introduced a device capable of the concurrent detection of cellular and molecular markers from a single sample fluid. Here, an improved design, which achieves affinity as well as size-based separation of captured targets using antibody-conjugated magnetic beads and a silicon chip containing micro-apertures, is presented. Upon injection of the sample, the integration of magnetic attraction with the micro-aperture chip permits larger cell-bead complexes to be isolated in an upper chamber with the smaller protein-bead complexes and remaining beads passing through the micro-apertures into the lower chamber. This enhances captured cell purity for on chip quantification, allows the separate retrieval of captured cells and proteins for downstream analysis, and enables higher bead concentrations for improved multiplexed ligand targeting. Using LNCaP cells and prostate specific membrane antigen (PSMA) to model prostate cancer, the device was able to detect 34 pM of spiked PSMA and achieve a cell capture efficiency of 93% from culture media. LNCaP cells and PSMA were then spiked into diluted healthy human blood to mimic a cancer patient. The device enabled the detection of spiked PSMA (relative to endogenous PSMA) while recovering 85-90% of LNCaP cells which illustrated the potential of new assays for the diagnosis of prostate cancer.

Neutral endopeptidase inhibits neuropeptide-mediated transactivation of the insulin-like growth factor receptor-Akt cell survival pathway.

PubMed

Sumitomo, M; Milowsky, M I; Shen, R; Navarro, D; Dai, J; Asano, T; Hayakawa, M; Nanus, D M

2001-04-15

G-protein coupled receptor (GPCR) agonists such as neuropeptides activate the insulin-like growth factor-1 receptor (IGF-IR) or the serine-threonine protein kinase Akt, suggesting that neuropeptides-GPCR signaling can cross-communicate with IGF-IR-Akt signaling pathways. Neutral endopeptidase 24.11 (NEP) is a cell-surface peptidase that cleaves and inactivates the neuropeptides endothelin-1 (ET-1) and bombesin, which are implicated in progression to androgen-independent prostate cancer (PC). We investigated the mechanisms of NEP regulation of neuropeptide-mediated cell survival in PC cells, including whether neuropeptide substrates of NEP induce phosphorylations of IGF-IR and Akt in PC cells. Western analyses revealed ET-1 and bombesin treatment induced phosphorylation of IGF-IRbeta and Akt independent of IGF-I in TSU-Pr1, DU145, and PC-3 PC cells, which lack NEP expression, but not in NEP-expressing LNCaP cells. Recombinant NEP and induced NEP expression in TSU-Pr1 cells using a tetracycline-repressive expression system inhibited ET-1-mediated phosphorylation of IGF-IRbeta and Akt, and blocked the protective effects of ET-1 against apoptosis induced by serum starvation. Incubation of TSU-Pr1 cells with specific kinase inhibitors together with ET-1 or bombesin showed that IGF-IR activation is required for neuropeptide-induced Akt phosphorylation, and that neuropeptide-induced Akt activation is predominantly mediated by Src and phosphatidylinositol 3-kinase but not by mitogen-activated protein kinase or protein kinase C. These data show that the neuropeptides ET-1 and bombesin stimulate ligand-independent activation of the IGF-IR, which results in Akt activation, and that this cross-communication between GPCR and IGF-IR signaling is inhibited by NEP.

Differential display RT PCR of total RNA from human foreskin fibroblasts for investigation of androgen-dependent gene expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nitsche, E.M.; Moquin, A.; Adams, P.S.

1996-05-03

Male sexual differentiation is a process that involves androgen action via the androgen receptor. Defects in the androgen receptor, many resulting from point mutations in the androgen receptor gene, lead to varying degrees of impaired masculinization in chromosomally male individuals. To date no specific androgen regulated morphogens involved in this process have been identified and no marker genes are known that would help to predict further virilization in infants with partial androgen insensitivity. In the present study we first show data on androgen regulated gene expression investigated by differential display reverse transcription PCR (dd RT PCR) on total RNA frommore » human neonatal genital skin fibroblasts cultured in the presence or absence of 100 nM testosterone. Using three different primer combinations, 54 cDNAs appeared to be regulated by androgens. Most of these sequences show the characteristics of expressed mRNAs but showed no homology to sequences in the database. However 15 clones with significant homology to previously cloned sequences were identified. Seven cDNAs appear to be induced by androgen withdrawal. Of these, five are similar to ETS (expression tagged sequences) from unknown genes; the other two show significant homology to the cDNAs of ubiquitin and human guanylate binding protein 2 (GBP-2). In addition, we have identified 8 cDNA clones which show homologies to other sequences in the database and appear to be upregulated in the presence of testosterone. Three differential expressed sequences show significant homology to the cDNAs of L-plastin and one to the cDNA of testican. This latter gene codes for a proteoglycan involved in cell social behavior and therefore of special interest in this context. The results of this study are of interest in further investigation of normal and disturbed androgen-dependent gene expression. 49 refs., 2 figs., 5 tabs.« less

Selective Androgen Receptor Modulator RAD140 Is Neuroprotective in Cultured Neurons and Kainate-Lesioned Male Rats

PubMed Central

Jayaraman, Anusha; Christensen, Amy; Moser, V. Alexandra; Vest, Rebekah S.; Miller, Chris P.; Hattersley, Gary

2014-01-01

The decline in testosterone levels in men during normal aging increases risks of dysfunction and disease in androgen-responsive tissues, including brain. The use of testosterone therapy has the potential to increase the risks for developing prostate cancer and or accelerating its progression. To overcome this limitation, novel compounds termed “selective androgen receptor modulators” (SARMs) have been developed that lack significant androgen action in prostate but exert agonist effects in select androgen-responsive tissues. The efficacy of SARMs in brain is largely unknown. In this study, we investigate the SARM RAD140 in cultured rat neurons and male rat brain for its ability to provide neuroprotection, an important neural action of endogenous androgens that is relevant to neural health and resilience to neurodegenerative diseases. In cultured hippocampal neurons, RAD140 was as effective as testosterone in reducing cell death induced by apoptotic insults. Mechanistically, RAD140 neuroprotection was dependent upon MAPK signaling, as evidenced by elevation of ERK phosphorylation and inhibition of protection by the MAPK kinase inhibitor U0126. Importantly, RAD140 was also neuroprotective in vivo using the rat kainate lesion model. In experiments with gonadectomized, adult male rats, RAD140 was shown to exhibit peripheral tissue-specific androgen action that largely spared prostate, neural efficacy as demonstrated by activation of androgenic gene regulation effects, and neuroprotection of hippocampal neurons against cell death caused by systemic administration of the excitotoxin kainate. These novel findings demonstrate initial preclinical efficacy of a SARM in neuroprotective actions relevant to Alzheimer's disease and related neurodegenerative diseases. PMID:24428527

Computational Modeling and Simulation of Genital Tubercle ...

EPA Pesticide Factsheets

Hypospadias is a developmental defect of urethral tube closure that has a complex etiology. Here, we describe a multicellular agent-based model of genital tubercle development that simulates urethrogenesis from the urethral plate stage to urethral tube closure in differentiating male embryos. The model, constructed in CompuCell3D, implemented spatially dynamic signals from SHH, FGF10, and androgen signaling pathways. These signals modulated stochastic cell behaviors, such as differential adhesion, cell motility, proliferation, and apoptosis. Urethral tube closure was an emergent property of the model that was quantitatively dependent on SHH and FGF10 induced effects on mesenchymal proliferation and endodermal apoptosis, ultimately linked to androgen signaling. In the absence of androgenization, simulated genital tubercle development defaulted to the female condition. Intermediate phenotypes associated with partial androgen deficiency resulted in incomplete closure. Using this computer model, complex relationships between urethral tube closure defects and disruption of underlying signaling pathways could be probed theoretically in multiplex disturbance scenarios and modeled into probabilistic predictions for individual risk for hypospadias and potentially other developmental defects of the male genital tubercle. We identify the minimal molecular network that determines the outcome of male genital tubercle development in mice.

Elevated phospholipase D activity in androgen-insensitive prostate cancer cells promotes both survival and metastatic phenotypes.

PubMed

Utter, Matthew; Chakraborty, Sohag; Goren, Limor; Feuser, Lucas; Zhu, Yuan-Shan; Foster, David A

2018-06-01

Prostate cells are hormonally driven to grow and divide. Typical treatments for prostate cancer involve blocking activation of the androgen receptor by androgens. Androgen deprivation therapy can lead to the selection of cancer cells that grow and divide independently of androgen receptor activation. Prostate cancer cells that are insensitive to androgens commonly display metastatic phenotypes and reduced long-term survival of patients. In this study we provide evidence that androgen-insensitive prostate cancer cells have elevated PLD activity relative to the androgen-sensitive prostate cancer cells. PLD activity has been linked with promoting survival in many human cancer cell lines; and consistent with the previous studies, suppression of PLD activity in the prostate cancer cells resulted in apoptotic cell death. Of significance, suppressing the elevated PLD activity in androgen resistant prostate cancer lines also blocked the ability of these cells to migrate and invade Matrigel™. Since survival signals are generally an early event in tumorigenesis, the apparent coupling of survival and metastatic phenotypes implies that metastasis is an earlier event in malignant prostate cancer than generally thought. This finding has implications for screening strategies designed to identify prostate cancers before dissemination. Copyright © 2018 Elsevier B.V. All rights reserved.

IAP Antagonists Enhance Apoptotic Response to Enzalutamide in Castration-Resistant Prostate Cancer Cells via Autocrine TNF-α Signaling.

PubMed

Pilling, Amanda B; Hwang, Ok; Boudreault, Alain; Laurent, Alain; Hwang, Clara

2017-06-01

Castration-resistant prostate cancer (CRPC) remains incurable and identifying effective treatments continues to present a clinical challenge. Although treatment with enzalutamide, a second generation androgen receptor (AR) antagonist, prolongs survival in prostate cancer patients, responses can be limited by intrinsic resistance or acquired resistance. A potential mechanism of resistance to androgen axis inhibition is evasion of apoptosis. Inhibitor of apoptosis proteins (IAPs) are found to be overexpressed in prostate cancer and function to block apoptosis and promote survival signaling. Novel, small-molecule IAP antagonists, such as AEG40995, are emerging as a strategy to induce apoptosis and increase therapeutic response in cancer. Human prostate cancer cell lines LNCaP and C4-2 were treated with enzalutamide with or without addition of IAP antagonist AEG40995 and proliferation and survival were determined by MTS and clonogenic assay. Western blot was used to evaluate IAP protein expression changes and PARP-1 cleavage was assessed as indication of apoptosis. Flow cytometry was performed to analyze apoptosis in treated cells. Caspase activity was determined by luminescence assay. Quantitative real-time PCR and immunometric ELISA was used to assess TNF-α (transcript and protein levels, respectively) in response to treatment. In this study, we demonstrate that IAP antagonist AEG40995 exhibits minimal effects on prostate cancer cell proliferation or survival, but rapidly degrades cIAP1 protein. Combination treatment with enzalutamide demonstrates that AEG40995 increases apoptosis and reduces proliferation and clonogenic survival in cell line models of prostate cancer. Mechanistically, we demonstrate that apoptosis in response to enzalutamide and IAP antagonist requires activation of caspase-8, suggesting extrinsic/death receptor apoptosis signaling. Assessment of TNF-α in response to combination treatment with enzalutamide and AEG40995 reveals increased mRNA expression and autocrine protein secretion. Blocking TNF-α signaling abrogates the apoptotic response demonstrating that TNF-α plays a critical role in executing cell death in response to this drug combination. These findings suggest that IAP antagonists can increase sensitivity and amplify the caspase-mediated apoptotic response to enzalutamide through TNF-α signaling mechanisms. Combination with an IAP antagonist increases enzalutamide sensitivity, lowers the apoptotic threshold and may combat drug resistance in patients with prostate cancer. Prostate 77:866-877, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Chemical genetics analysis of an aniline mustard anticancer agent reveals complex I of the electron transport chain as a target.

PubMed

Fedeles, Bogdan I; Zhu, Angela Y; Young, Kellie S; Hillier, Shawn M; Proffitt, Kyle D; Essigmann, John M; Croy, Robert G

2011-09-30

The antitumor agent 11β (CAS 865070-37-7), consisting of a DNA-damaging aniline mustard linked to an androgen receptor (AR) ligand, is known to form covalent DNA adducts and to induce apoptosis potently in AR-positive prostate cancer cells in vitro; it also strongly prevents growth of LNCaP xenografts in mice. The present study describes the unexpectedly strong activity of 11β against the AR-negative HeLa cells, both in cell culture and tumor xenografts, and uncovers a new mechanism of action that likely explains this activity. Cellular fractionation experiments indicated that mitochondria are the major intracellular sink for 11β; flow cytometry studies showed that 11β exposure rapidly induced oxidative stress, mitochondria being an important source of reactive oxygen species (ROS). Additionally, 11β inhibited oxygen consumption both in intact HeLa cells and in isolated mitochondria. Specifically, 11β blocked uncoupled oxygen consumption when mitochondria were incubated with complex I substrates, but it had no effect on oxygen consumption driven by substrates acting downstream of complex I in the mitochondrial electron transport chain. Moreover, 11β enhanced ROS generation in isolated mitochondria, suggesting that complex I inhibition is responsible for ROS production. At the cellular level, the presence of antioxidants (N-acetylcysteine or vitamin E) significantly reduced the toxicity of 11β, implicating ROS production as an important contributor to cytotoxicity. Collectively, our findings establish complex I inhibition and ROS generation as a new mechanism of action for 11β, which supplements conventional DNA adduct formation to promote cancer cell death.

High activity of mitochondrial glycerophosphate dehydrogenase and glycerophosphate-dependent ROS production in prostate cancer cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chowdhury, Subir K.R.; Department of Pathology and Molecular Medicine, McMaster University, 1200 Main St. West, Hamilton, Ont., L8N 3Z5; Gemin, Adam

Most malignant cells are highly glycolytic and produce high levels of reactive oxygen species (ROS) compared to normal cells. Mitochondrial glycerophosphate dehydrogenase (mGPDH) participates in the reoxidation of cytosolic NADH by delivering reducing equivalents from this molecule into the electron transport chain, thus sustaining glycolysis. Here, we investigate the role of mGPDH in maintaining an increased rate of glycolysis and evaluate glycerophosphate-dependent ROS production in prostate cancer cell lines (LNCaP, DU145, PC3, and CL1). Immunoblot, polarographic, and spectrophotometric analyses revealed that mGPDH abundance and activity was significantly elevated in prostate cancer cell lines when compared to the normal prostate epithelialmore » cell line PNT1A. Furthermore, both the glycolytic capacity and glycerophosphate-dependent ROS production was increased 1.68- to 4.44-fold and 5- to 7-fold, respectively, in prostate cancer cell lines when compared to PNT1A cells. Overall, these data demonstrate that mGPDH is involved in maintaining a high rate of glycolysis and is an important site of electron leakage leading to ROS production in prostate cancer cells.« less

Inhibitory effect of a redox-silent analogue of tocotrienol on hypoxia adaptation in prostate cancer cells.

PubMed

Shiozawa, Nobuya; Sugahara, Ryosuke; Namiki, Kozue; Sato, Chiaki; Ando, Akira; Sato, Ayami; Virgona, Nantiga; Yano, Tomohiro

2017-03-01

Prostate cancer (PCa) is one of the most common cancers in Western countries and acquires a malignant phenotype, androgen-independent growth. PCa under hypoxia often has resistance to chemotherapy and radiotherapy. However, an effective therapy against PCa under hypoxia has not yet been established. In this report, we investigated the inhibitory effect of a redox-silent analogue of tocotrienol on the survival of a human androgen-independent PCa cell line (PC3) under hypoxia. We found that the redox-silent analogue exerted a cytotoxic effect on PC3 cells in a dose-dependent manner irrespective of either hypoxia or normoxia. Moreover, under hypoxia, the analogue dose dependently reduced the protein levels of hypoxia-inducible factor (HIF)-1α and HIF-2α. In addition, a specific inhibitor toward HIF-1α induced cytotoxicity on PC3 cells, whereas selective inhibition of HIF-2α exerted no effect. Furthermore, suppression of HIFs levels by the analogue in hypoxic PC3 cells was closely associated with the inactivation of Fyn, a member of the nonreceptor tyrosine kinase family, as confirmed by the action of a specific inhibitor toward the kinase (PP2). Taken together, these results suggest that the tocotrienol analogue could inhibit the survival of PC3 cells under hypoxia, mainly by the inhibition of Fyn/HIF-1α signaling, and this may lead to the establishment of a new effective therapy for androgen-independent PCa.

Structurally related odorant ligands of the olfactory receptor OR51E2 differentially promote metastasis emergence and tumor growth

PubMed Central

Sanz, Guenhaël; Leray, Isabelle; Grébert, Denise; Antoine, Sharmilee; Acquistapace, Adrien; Muscat, Adeline; Boukadiri, Abdelhak; Mir, Lluis M.

2017-01-01

Olfactory receptors are G protein-coupled receptors. Some of them are expressed in tumor cells, such as the OR51E2 receptor overexpressed in LNCaP prostate cancer cells. It is considered a prostate tumor marker. We previously demonstrated that this receptor is able to promote LNCaP cell invasiveness in vitro upon stimulation with its odorant agonist β-ionone, leading to increased generation of metastases in vivo. In the present study, we show that even a relatively short exposure to β-ionone is sufficient to promote metastasis emergence. Moreover, α-ionone, considered an OR51E2 antagonist, in fact promotes prostate tumor growth in vivo. The combination of α-ionone with β-ionone triggers a higher increase in the total tumor burden than each molecule alone. To support the in vivo results, we demonstrate in vitro that α-ionone is a real agonist of OR51E2, mainly sustaining LNCaP cell growth, while β-ionone mainly promotes cell invasiveness. So, while structurally close, α-ionone and β-ionone appear to induce different cellular effects, both leading to increased tumor aggressiveness. This behaviour could be explained by a different coupling to downstream effectors, as it has been reported for the so-called biased ligands of other G protein-coupled receptors. PMID:28032594

Androgen responsiveness of the new human endometrial cancer cell line MFE-296.

PubMed

Hackenberg, R; Beck, S; Filmer, A; Hushmand Nia, A; Kunzmann, R; Koch, M; Slater, E P; Schulz, K D

1994-04-01

MFE-296 endometrial cancer cells express androgen receptors in vitro. These cells, which are tumorigenic in nude mice, are derived from a moderately differentiated human endometrial adenocarcinoma. They express vimentin and the cytokeratins 7, 8, 18, and 19. Karyotyping revealed near-tetraploidy for most of the cells. No marker chromosomes were observed. DNA analyses confirmed the genetic identity of the cell line and the patient from whom the cell line was derived. Proliferation of MFE-296 cells was inhibited by the progestin R5020 and the androgen dihydrotestosterone (DHT). The inhibition of proliferation by DHT was antagonized by the antiandrogen Casodex, demonstrating the involvement of the androgen receptor. Androgen binding was determined at 22,000 binding sites per cell using a whole-cell assay (KD = 0.05 nM) and 30 fmol/mg protein with the dextran charcoal method; 7 fmol/mg protein of progesterone receptors were found, whereas estrogen receptors were below 5 fmol/mg protein. The androgen receptor was functionally intact, as demonstrated by transfection experiments with a reporter-gene construct, containing an androgen-responsive element. In MFE-296 cells the content of the androgen receptor was up-regulated by its own ligand.

A screen for transcription factor targets of glycogen synthase kinase-3 highlights an inverse correlation of NFκB and androgen receptor signaling in prostate cancer.

PubMed

Campa, Victor M; Baltziskueta, Eder; Bengoa-Vergniory, Nora; Gorroño-Etxebarria, Irantzu; Wesołowski, Radosław; Waxman, Jonathan; Kypta, Robert M

2014-09-30

Expression of Glycogen Synthase Kinase-3 (GSK-3) is elevated in prostate cancer and its inhibition reduces prostate cancer cell proliferation, in part by reducing androgen receptor (AR) signaling. However, GSK-3 inhibition can also activate signals that promote cell proliferation and survival, which may preclude the use of GSK-3 inhibitors in the clinic. To identify such signals in prostate cancer, we screened for changes in transcription factor target DNA binding activity in GSK-3-silenced cells. Among the alterations was a reduction in AR DNA target binding, as predicted from previous studies, and an increase in NFκB DNA target binding. Consistent with the latter, gene silencing of GSK-3 or inhibition using the GSK-3 inhibitor CHIR99021 increased basal NFκB transcriptional activity. Activation of NFκB was accompanied by an increase in the level of the NFκB family member RelB. Conversely, silencing RelB reduced activation of NFκB by CHIR99021. Furthermore, the reduction of prostate cancer cell proliferation by CHIR99021 was potentiated by inhibition of NFκB signaling using the IKK inhibitor PS1145. Finally, stratification of human prostate tumor gene expression data for GSK3 revealed an inverse correlation between NFκB-dependent and androgen-dependent gene expression, consistent with the results from the transcription factor target DNA binding screen. In addition, there was a correlation between expression of androgen-repressed NFκB target genes and reduced survival of patients with metastatic prostate cancer. These findings highlight an association between GSK-3/AR and NFκB signaling and its potential clinical importance in metastatic prostate cancer.

A screen for transcription factor targets of Glycogen Synthase Kinase-3 highlights an inverse correlation of NFκB and Androgen Receptor Signaling in Prostate Cancer

PubMed Central

Campa, Victor M.; Baltziskueta, Eder; Bengoa-Vergniory, Nora; Gorroño-Etxebarria, Irantzu; Wesołowski, Radosław; Waxman, Jonathan; Kypta, Robert M.

2014-01-01

Expression of Glycogen Synthase Kinase-3 (GSK-3) is elevated in prostate cancer and its inhibition reduces prostate cancer cell proliferation, in part by reducing androgen receptor (AR) signaling. However, GSK-3 inhibition can also activate signals that promote cell proliferation and survival, which may preclude the use of GSK-3 inhibitors in the clinic. To identify such signals in prostate cancer, we screened for changes in transcription factor target DNA binding activity in GSK-3-silenced cells. Among the alterations was a reduction in AR DNA target binding, as predicted from previous studies, and an increase in NFκB DNA target binding. Consistent with the latter, gene silencing of GSK-3 or inhibition using the GSK-3 inhibitor CHIR99021 increased basal NFκB transcriptional activity. Activation of NFκB was accompanied by an increase in the level of the NFκB family member RelB. Conversely, silencing RelB reduced activation of NFκB by CHIR99021. Furthermore, the reduction of prostate cancer cell proliferation by CHIR99021 was potentiated by inhibition of NFκB signaling using the IKK inhibitor PS1145. Finally, stratification of human prostate tumor gene expression data for GSK3 revealed an inverse correlation between NFκB-dependent and androgen-dependent gene expression, consistent with the results from the transcription factor target DNA binding screen. In addition, there was a correlation between expression of androgen-repressed NFκB target genes and reduced survival of patients with metastatic prostate cancer. These findings highlight an association between GSK-3/AR and NFκB signaling and its potential clinical importance in metastatic prostate cancer. PMID:25327559

20-Aminosteroids as a novel class of selective and complete androgen receptor antagonists and inhibitors of prostate cancer cell growth.

PubMed

Fousteris, Manolis A; Schubert, Undine; Roell, Daniela; Roediger, Julia; Bailis, Nikolaos; Nikolaropoulos, Sotiris S; Baniahmad, Aria; Giannis, Athanassios

2010-10-01

Here, the synthesis and the evaluation of novel 20-aminosteroids on androgen receptor (AR) activity is reported. Compounds 11 and 18 of the series inhibit both the wild type and the T877A mutant AR-mediated transactivation indicating AR antagonistic function. Interestingly, minor structural changes such as stereoisomers of the amino lactame moiety exhibit preferences for antagonism among wild type and mutant AR. Other tested nuclear receptors are only weakly or not affected. In line with this, the prostate cancer cell growth of androgen-dependent but not of cancer cells lacking expression of the AR is inhibited. Further, the expression of the prostate specific antigen used as a diagnostic marker is also repressed. Finally steroid 18 enhances cellular senescence that might explain in part the growth inhibition mediated by this derivative. Steroids 11 and 18 are the first steroids that act as complete AR antagonists and exhibit AR specificity. Copyright © 2010 Elsevier Ltd. All rights reserved.

Androgens Exert a Cysticidal Effect upon Taenia crassiceps by Disrupting Flame Cell Morphology and Function

PubMed Central

Ambrosio, Javier R.; Valverde-Islas, Laura; Nava-Castro, Karen E.; Palacios- Arreola, M. Isabel; Ostoa-Saloma, Pedro; Reynoso-Ducoing, Olivia; Escobedo, Galileo; Ruíz-Rosado, Azucena; Dominguez-Ramírez, Lenin; Morales-Montor, Jorge

2015-01-01

The effects of testosterone (T4) and dihydrotestosterone (DHT) on the survival of the helminth cestode parasite Taenia crassiceps, as well as their effects on actin, tubulin and myosin expression and their assembly into the excretory system of flame cells are described in this paper. In vitro evaluations on parasite viability, flow cytometry, confocal microscopy, video-microscopy of live flame cells, and docking experiments of androgens interacting with actin, tubulin, and myosin were conducted. Our results show that T4 and DHT reduce T. crassiceps viability in a dose- and time-dependent fashion, reaching 90% of mortality at the highest dose used (40 ng/ml) and time exposed (10 days) in culture. Androgen treatment does not induce differences in the specific expression pattern of actin, tubulin, and myosin isoforms as compared with control parasites. Confocal microscopy demonstrated a strong disruption of the parasite tegument, with reduced assembly, shape, and motion of flame cells. Docking experiments show that androgens are capable of affecting parasite survival and flame cell morphology by directly interacting with actin, tubulin and myosin without altering their protein expression pattern. We show that both T4 and DHT are able to bind actin, tubulin, and myosin affecting their assembly and causing parasite intoxication due to impairment of flame cell function. Live flame cell video microscopy showing a reduced motion as well changes in the shape of flame cells are also shown. In summary, T4 and DHT directly act on T. crassiceps cysticerci through altering parasite survival as well as the assembly and function of flame cells. PMID:26076446

Synthesis and evaluation of a novel urea-based 68Ga-complex for imaging PSMA binding in tumor.

PubMed

Zha, Zhihao; Ploessl, Karl; Choi, Seok Rye; Wu, Zehui; Zhu, Lin; Kung, Hank F

2018-04-01

Prostate specific membrane antigen (PSMA) is a well-established target for diagnostic and therapeutic applications for prostate cancer. It is know that [ 68 Ga]PSMA 11 ([ 68 Ga]Glu-NH-CO-NH-Lys(Ahx)-HBED-CC) is the most well studied PET imaging agent for detecting over expressed PSMA binding sites of tumors in humans. In an effort to provide new agents with improved characteristics for PET imaging, we report a novel [ 68 Ga]-Glu-NH-CO-NH-Lys(Ahx)-linker-HBED-CC conjugate with a novel O-(carboxymethyl)-L-tyrosine, as the linker group. Radiosynthesis was performed by a direct method. In vitro binding and cell internalization of [ 68 Ga]10 was investigated in PSMA positive LNCaP cell lines. Biodistribution and MicroPET imaging studies were performed in LNCaP tumor bearing mice. In vitro binding to LNCaP cells showed that nat Ga labeled O-(carboxymethyl)-L-tyrosine conjugate, [ nat Ga]10, displayed excellent affinity and specificity (IC 50  = 16.5 nM) a value comparable to that of PSMA 11. In vitro cell binding and internalization showed excellent uptake and retention; [ 68 Ga]10 displayed significantly higher cellular internalization than [ 68 Ga]PSMA 11 (12.5 vs 7.4% ID/10 6 cells at 1 h). Biodistribution studies in LNCaP tumor-bearing mice exhibited a high specific uptake in PSMA expressing tumors and fast clearance in normal organs (19.7 tumor/blood; 20.7 tumor/muscle at 1 h after iv injection). MicroPET imaging studies in mice confirmed that [ 68 Ga]10 displayed excellent uptake and distinctive tumor localization, which was blocked by iv injection of a competing drug, 2-PMPA. The preliminary results strongly suggest that [ 68 Ga]10 may be promising candidates as a PET imaging radiotracer for detecting PSMA expression in prostate cancer. Copyright © 2018. Published by Elsevier Inc.

Regulation of Androgen Receptor Expression Alters AMPK Phosphorylation in the Endometrium: In Vivo and In Vitro Studies in Women with Polycystic Ovary Syndrome

PubMed Central

Li, Xin; Pishdari, Bano; Cui, Peng; Hu, Min; Yang, Hong-Ping; Guo, Yan-Rong; Jiang, Hong-Yuan; Feng, Yi; Billig, Håkan; Shao, Ruijin

2015-01-01

The failure of reproductive success in polycystic ovary syndrome (PCOS) patients could be in part due to endometrial dysfunction. However, no studies have investigated any causality between androgen, androgen receptor (AR) expression, and adenosine monophosphate activated protein kinase (AMPK) activation in the endometrium under physiological and pathological conditions. In the present study, we show that 1) endometrial AR expression levels fluctuate in non-PCOS and PCOS patients during the menstrual cycle; 2) the menstrual phase-dependent alteration of p-AMPKα expression occurs in non-PCOS patients but not in PCOS patients; 3) AR expression is higher in PCOS patients than non-PCOS patients during hyperplasia while AMPKα activation (indicated by the ratio of p-AMPKα to AMPKα); and 4) co-localization of AR and Ki-67 in epithelial cell nuclei is observed in endometrial hyperplasia. Importantly, using in vitro human tissue culture and an in vivo 5α-dihydrotestosterone-treated rat model, we show that the action of androgen on AMPKα activation is likely mediated through nuclear AR, especially in epithelial cells. Collectively, we present evidence that AR expression and AMPKα activation depend on menstrual cycle phase and the presence of PCOS, and the data suggest that AR-mediated regulation of AMPKα activation might play a role in the development of endometrial hyperplasia. PMID:26681917

Epidaurus: aggregation and integration analysis of prostate cancer epigenome.

PubMed

Wang, Liguo; Huang, Haojie; Dougherty, Gregory; Zhao, Yu; Hossain, Asif; Kocher, Jean-Pierre A

2015-01-01

Integrative analyses of epigenetic data promise a deeper understanding of the epigenome. Epidaurus is a bioinformatics tool used to effectively reveal inter-dataset relevance and differences through data aggregation, integration and visualization. In this study, we demonstrated the utility of Epidaurus in validating hypotheses and generating novel biological insights. In particular, we described the use of Epidaurus to (i) integrate epigenetic data from prostate cancer cell lines to validate the activation function of EZH2 in castration-resistant prostate cancer and to (ii) study the mechanism of androgen receptor (AR) binding deregulation induced by the knockdown of FOXA1. We found that EZH2's noncanonical activation function was reaffirmed by its association with active histone markers and the lack of association with repressive markers. More importantly, we revealed that the binding of AR was selectively reprogramed to promoter regions, leading to the up-regulation of hundreds of cancer-associated genes including EGFR. The prebuilt epigenetic dataset from commonly used cell lines (LNCaP, VCaP, LNCaP-Abl, MCF7, GM12878, K562, HeLa-S3, A549, HePG2) makes Epidaurus a useful online resource for epigenetic research. As standalone software, Epidaurus is specifically designed to process user customized datasets with both efficiency and convenience. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Micro-Raman spectroscopy studies of changes in lipid composition in breast and prostate cancer cells treated with MPA and R1881 hormones

NASA Astrophysics Data System (ADS)

Potcoava, Mariana C.; Futia, Gregory L.; Aughenbaugh, Jessica; Schlaepfer, Isabel; Gibson, Emily A.

2014-03-01

Increasing interest in the role of lipids in cancer cell proliferation or resistance to drug therapies has motivated the need to develop better tools for cellular lipid analysis. Quantification of lipids in cells is typically done by destructive chromatography protocols that do not provide spatial information on lipid distribution and prevent dynamic live cell studies. Methods that allow the analysis of lipid content in live cells is therefore of great importance for research. Using Raman micro-spectroscopy we investigated whether the female hormone medroxyprogesterone acetate (MPA) and the synthetic androgen R1881 affect the lipid expression in breast (T47D) and prostate (LNCaP) cancer cells. Differences were noted in the spectral regions at 830-1800 cm-1 and 2800-3000 cm-1 when comparing different drug treatments. Significant changes were noticed for saturated (1063 - 1125 cm-1, 1295 cm-1 and 1439 cm-1), unsaturated (1262 cm-1 and 1656 cm-1, and 1720 - 1748 cm-1) chemical bonds, suggesting that the composition of the lipid droplets was changed by the hormone treatments. Also, significant differences were observed in the high frequency regions of lipids and proteins at 2851 cm-1 and around 2890 cm-1. Principal component analysis with Linear Discriminant Analysis (PCA-LDA) of the Raman spectra was able to differentiate between cancer cells that were treated with MPA, R1881 or vehicle (P < 0.05). Future work includes analysis to determine exact lipid composition and concentrations as well as development of clinical techniques to characterize differences in patient tumor lipid profiles to determine response to drug treatment and prognosis.

Pituitary Androgen Receptor Signalling Regulates Prolactin but Not Gonadotrophins in the Male Mouse

PubMed Central

O’Hara, Laura; Curley, Michael; Tedim Ferreira, Maria; Cruickshanks, Lyndsey; Milne, Laura; Smith, Lee B.

2015-01-01

Production of the androgen testosterone is controlled by a negative feedback loop within the hypothalamic-pituitary-gonadal (HPG) axis. Stimulation of testicular Leydig cells by pituitary luteinising hormone (LH) is under the control of hypothalamic gonadotrophin releasing hormone (GnRH), while suppression of LH secretion by the pituitary is controlled by circulating testosterone. Exactly how androgens exert their feedback control of gonadotrophin secretion (and whether this is at the level of the pituitary), as well as the role of AR in other pituitary cell types remains unclear. To investigate these questions, we exploited a transgenic mouse line (Foxg1Cre/+; ARfl/y) which lacks androgen receptor in the pituitary gland. Both circulating testosterone and gonadotrophins are unchanged in adulthood, demonstrating that AR signalling is dispensable in the male mouse pituitary for testosterone-dependent regulation of LH secretion. In contrast, Foxg1Cre/+; ARfl/y males have a significant increase in circulating prolactin, suggesting that, rather than controlling gonadotrophins, AR-signalling in the pituitary acts to suppress aberrant prolactin production in males. PMID:25799562

Potential prostate cancer drug target: bioactivation of androstanediol by conversion to dihydrotestosterone.

PubMed

Mohler, James L; Titus, Mark A; Wilson, Elizabeth M

2011-09-15

High-affinity binding of dihydrotestosterone (DHT) to the androgen receptor (AR) initiates androgen-dependent gene activation, required for normal male sex development in utero, and contributes to prostate cancer development and progression in men. Under normal physiologic conditions, DHT is synthesized predominantly by 5α-reduction of testosterone, the major circulating androgen produced by the testis. During androgen deprivation therapy, intratumoral androgen production is sufficient for AR activation and prostate cancer growth, even though circulating testicular androgen levels are low. Recent studies indicate that the metabolism of 5α-androstane-3α, 17β-diol by 17β-hydroxysteroid dehydrogenase 6 in benign prostate and prostate cancer cells is a major biosynthetic pathway for intratumoral synthesis of DHT, which binds AR and initiates transactivation to promote prostate cancer growth during androgen deprivation therapy. Drugs that target the so-called backdoor pathway of DHT synthesis provide an opportunity to enhance clinical response to luteinizing-hormone-releasing hormone (LHRH) agonists or antagonists, AR antagonists, and inhibitors of 5α-reductase enzymes (finasteride or dutasteride), and other steroid metabolism enzyme inhibitors (ketoconazole or the recently available abiraterone acetate). ©2011 AACR.

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-kB/MMP-9 Pathway.

PubMed

Chiu, Chun-Tang; Chen, Jing-Hsien; Chou, Fen-Pi; Lin, Hui-Hsuan

2015-06-24

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-kB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-kB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-κB/MMP-9 Pathway

PubMed Central

Chiu, Chun-Tang; Chen, Jing-Hsien; Chou, Fen-Pi; Lin, Hui-Hsuan

2015-01-01

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-κB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-κB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells. PMID:26115086