Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis.

PubMed

Lee, Seung Joon; Langhans, Sigrid A

2012-01-26

Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin.

Anaphase-promoting complex/cyclosome protein Cdc27 is a target for curcumin-induced cell cycle arrest and apoptosis

PubMed Central

2012-01-01

Background Curcumin (diferuloylmethane), the yellow pigment in the Asian spice turmeric, is a hydrophobic polyphenol from the rhizome of Curcuma longa. Because of its chemopreventive and chemotherapeutic potential with no discernable side effects, it has become one of the major natural agents being developed for cancer therapy. Accumulating evidence suggests that curcumin induces cell death through activation of apoptotic pathways and inhibition of cell growth and proliferation. The mitotic checkpoint, or spindle assembly checkpoint (SAC), is the major cell cycle control mechanism to delay the onset of anaphase during mitosis. One of the key regulators of the SAC is the anaphase promoting complex/cyclosome (APC/C) which ubiquitinates cyclin B and securin and targets them for proteolysis. Because APC/C not only ensures cell cycle arrest upon spindle disruption but also promotes cell death in response to prolonged mitotic arrest, it has become an attractive drug target in cancer therapy. Methods Cell cycle profiles were determined in control and curcumin-treated medulloblastoma and various other cancer cell lines. Pull-down assays were used to confirm curcumin binding. APC/C activity was determined using an in vitro APC activity assay. Results We identified Cdc27/APC3, a component of the APC/C, as a novel molecular target of curcumin and showed that curcumin binds to and crosslinks Cdc27 to affect APC/C function. We further provide evidence that curcumin preferably induces apoptosis in cells expressing phosphorylated Cdc27 usually found in highly proliferating cells. Conclusions We report that curcumin directly targets the SAC to induce apoptosis preferably in cells with high levels of phosphorylated Cdc27. Our studies provide a possible molecular mechanism why curcumin induces apoptosis preferentially in cancer cells and suggest that phosphorylation of Cdc27 could be used as a biomarker to predict the therapeutic response of cancer cells to curcumin. PMID:22280307

ERdj5 sensitizes neuroblastoma cells to endoplasmic reticulum stress-induced apoptosis.

PubMed

Thomas, Christophoros G; Spyrou, Giannis

2009-03-06

Down-regulation of the unfolded protein response (UPR) can be therapeutically valuable in cancer treatment, and endoplasmic reticulum (ER)-resident chaperone proteins may thus be targets for developing novel chemotherapeutic strategies. ERdj5 is a novel ER chaperone that regulates the ER-associated degradation of misfolded proteins through its associations with EDEM and the ER stress sensor BiP. To investigate whether ERdj5 can regulate ER stress signaling pathways, we exposed neuroblastoma cells overexpressing ERdj5 to ER stress inducers. ERdj5 promoted apoptosis in tunicamycin, thapsigargin, and bortezomib-treated cells. To provide further evidence that ERdj5 induces ER stress-regulated apoptosis, we targeted Bcl-2 to ER of ERdj5-overexpressing cells. Targeting the Bcl-2 to ER prevented the apoptosis induced by ER stress inducers but not by non-ER stress apoptotic stimuli, suggesting induction of ER stress-regulated apoptosis by ERdj5. ERdj5 enhanced apoptosis by abolishing the ER stress-induced phosphorylation of eukaryotic translation initiation factor 2alpha (eIF2alpha) and the subsequent translational repression. ERdj5 was found to inhibit the eIF2alpha phosphorylation under ER stress through inactivating the pancreatic endoplasmic reticulum kinase. The compromised integrated stress response observed in ERdj5-overexpressing ER-stressed cells due to repressed eIF2alpha phosphorylation correlated with impaired neuroblastoma cell resistance under ER stress. These results demonstrate that ERdj5 decreases neuroblastoma cell survival by down-regulating the UPR, raising the possibility that this protein could be a target for anti-tumor approaches.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction.

PubMed

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-05-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent.

Isthmin targets cell-surface GRP78 and triggers apoptosis via induction of mitochondrial dysfunction

PubMed Central

Chen, M; Zhang, Y; Yu, V C; Chong, Y-S; Yoshioka, T; Ge, R

2014-01-01

Isthmin (ISM) is a secreted 60-kDa protein that potently induces endothelial cell (EC) apoptosis. It suppresses tumor growth and angiogenesis in mice when stably overexpressed in cancer cells. Although αvβ5 integrin serves as a low-affinity receptor for ISM, the mechanism by which ISM mediates antiangiogenesis and apoptosis in ECs remain to be fully resolved. In this work, we report the identification of cell-surface glucose-regulated protein 78 kDa (GRP78) as a high-affinity receptor for ISM (Kd=8.6 nM). We demonstrated that ISM-GRP78 interaction triggers apoptosis not only in activated ECs but also in cancer cells expressing high level of cell-surface GRP78. Normal cells and benign tumor cells tend to express low level of cell-surface GRP78 and are resistant to ISM-induced apoptosis. Upon binding to GRP78, ISM is internalized into ECs through clathrin-dependent endocytosis that is essential for its proapoptotic activity. Once inside the cell, ISM co-targets with GRP78 to mitochondria where it interacts with ADP/ATP carriers on the inner membrane and blocks ATP transport from mitochondria to cytosol, thereby causing apoptosis. Hence, ISM is a novel proapoptotic ligand that targets cell-surface GRP78 to trigger apoptosis by inducing mitochondrial dysfunction. The restricted and high-level expression of cell-surface GRP78 on cancer cells and cancer ECs make them uniquely susceptible to ISM-targeted apoptosis. Indeed, systemic delivery of recombinant ISM potently suppressed subcutaneous 4T1 breast carcinoma and B16 melanoma growth in mice by eliciting apoptosis selectively in the cancer cells and cancer ECs. Together, this work reveals a novel ISM-GRP78 apoptosis pathway and demonstrates the potential of ISM as a cancer-specific and dual-targeting anticancer agent. PMID:24464222

Lipocalin 2, a new GADD153 target gene, as an apoptosis inducer of endoplasmic reticulum stress in lung cancer cells

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

Hsin, I-Lun; Hsiao, Yueh-Chieh; Institute of Medicine, Chung Shan Medical University, Taichung 40201, Taiwan

2012-09-15

Endoplasmic reticulum (ER) stress is activated under severe cellular conditions. GADD153, a member of the C/EBP family, is an unfolded protein response (UPR) responsive transcription factor. Increased levels of lipocalin 2, an acute phase protein, have been found in several epithelial cancers. The aim of this study is to investigate the function of lipocalin 2 in lung cancer cells under ER stress. Treatment with thapsigargin, an ER stress activator, led to increases in cytotoxicity, ER stress, apoptosis, and lipocalin 2 expression in A549 cells. GADD153 silencing decreased lipocalin 2 expression in A549 cells. On chromatin immunoprecipitation assay, ER stress increasedmore » GADD153 DNA binding to lipocalin 2 promoter. Furthermore, silencing of lipocalin 2 mitigated ER stress-mediated apoptosis in A549 cells. Our findings demonstrated that lipocalin 2 is a new GADD153 target gene that mediates ER stress-induced apoptosis. Highlights: ► We demonstrate that Lipocalin 2 is a new GADD153 target gene. ► Lipocalin 2 mediates ER stress-induced apoptosis. ► ER stress-induced lipocalin 2 expression is calcium-independent in A549 cells. ► Lipocalin 2 dose not play a major role in ER stress-induced autophagy.« less

miR-429 mediates δ-tocotrienol-induced apoptosis in triple-negative breast cancer cells by targeting XIAP

PubMed Central

Wang, Chen; Ju, Hong; Shen, Chunyan; Tong, Zhongsheng

2015-01-01

Vitamin E δ-tocotrienol has been reported to possess anticancer activity both in vitro and in vivo. However, the underlying molecular mechanisms of δ-tocotrienol induced apoptosis in triple-negative breast cancer are not fully understood. Here, we reported that microRNA-429 (miR-429) is up-regulated in two TNBC cell lines (MDA-MB-231 and MDA-MB-468), treated with δ-tocotrienol. Inhibition of miR-429 may partially rescue the apoptosis induced by δ-tocotrienol in MDA-MB-231 cells. We also showed that the forced expression of miR-429 was sufficient to lead to apoptosis in MDA-MB-231 cells. Furthermore, we identified X-linked inhibitor of apoptosis protein (XIAP) as one of miR-429’s target genes. These results suggest that the activation of miR-429 by δ-tocotrienol may be an effective approach for the prevention and treatment of triple-negative breast cancer. PMID:26629059

Adenovirus small interfering RNA targeting ezrin induces apoptosis and inhibits metastasis of human osteosarcoma MG-63 cells.

PubMed

Tao, Zhi-Wei; Zou, Ping-An

2018-06-13

Osteosarcoma is a disease prone to recurrence and metastasis, and adenovirus expression vector is frequently studied as a therapeutic target of osteosarcoma in recent year. This study attempts to explore the effect of adenovirus-mediated small interfering RNA (siRNA) targeting ezrin on the proliferation, migration, invasion and apoptosis of human osteosarcoma MG-63 cells. Human osteosarcoma MG-63 cell line was selected for construction of recombinant adenovirus vector. The mRNA and protein levels of ezrin, Bcl2-associated X protein (Bax), B cell lymphoma-2 (Bcl-2), p21, p53, Caspase-3, matrix metalloproteinase 2 (MMP-2) and MMP-9, Cyclin D1, and cyclin-dependent kinase 4a (CDK4a) were determined. Through ELISA, the levels of Caspase-3, MMP-2 and MMP-9 were examined. Finally, human osteosarcoma MG-63 cell viability, growth, invasion, migration, and apoptosis were detected. Initially, adenovirus expression vector of ezrin was constructed by ezrin 2 siRNA sequence. Adenovirus-mediated siRNA targeting ezrin reduced expression of ezrin in MG-63 cells. The results revealed that adenovirus-mediated siRNA targeting ezrin elevated expression levels of Bax, P21, P53, and Caspase-3, Cyclin D1, and CDK4a and reduced expression levels of Bcl-2, MMP-2, and MMP-9. Furthermore, adenovirus-mediated siRNA targeting ezrin inhibited human osteosarcoma MG-63 cell viability, growth, invasion, and migration, and promoted apoptosis. Our study demonstrates that adenovirus-mediated siRNA targeting ezrin can induce apoptosis and inhibit the proliferation, migration and invasion of human osteosarcoma MG-63 cells. ©2018 The Author(s).

Piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways.

PubMed

Wang, Hongfei; Wang, Yongqiang; Gao, Hongmei; Wang, Bing; Dou, Lin; Li, Yin

2018-02-01

Piperlongumine is an alkaloid compound extracted from Piper longum L. It is a chemical substance with various pharmacological effects and medicinal value, including anti-tumor, lipid metabolism regulatory, antiplatelet aggregation and analgesic properties. The present study aimed to understand whether piperlongumine induces the apoptosis and autophagy of leukemic cells, and to identify the mechanism involved. Cell viability and autophagy were detected using MTT, phenazine methyl sulfate and trypan blue exclusion assays. The apoptosis rate was calculated using flow cytometry. The protein expression levels of microtubule-associated protein 1A/1B-light chain 3, Akt and mechanistic target of rapamycin (mTOR) were measured using western blotting. The cell growth of leukemic cells was completely inhibited following treatment with piperlongumine, and marked apoptosis was also induced. Dead cells as a result of autophagy were stained using immunofluorescence and observed under a light microscope. Phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling was suppressed by treatment with piperlongumine, while p38 signaling and caspase-3 activity were induced by treatment with piperlongumine. It was concluded that piperlongumine induces apoptosis and autophagy in leukemic cells through targeting the PI3K/Akt/mTOR and p38 signaling pathways.

Targeting ceramide metabolic pathway induces apoptosis in human breast cancer cell lines

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

Vethakanraj, Helen Shiphrah; Babu, Thabraz Ahmed; Sudarsanan, Ganesh Babu

2015-08-28

The sphingolipid ceramide is a pro apoptotic molecule of ceramide metabolic pathway and is hydrolyzed to proliferative metabolite, sphingosine 1 phosphate by the action of acid ceramidase. Being upregulated in the tumors of breast, acid ceramidase acts as a potential target for breast cancer therapy. We aimed at targeting this enzyme with a small molecule acid ceramidase inhibitor, Ceranib 2 in human breast cancer cell lines MCF 7 and MDA MB 231. Ceranib 2 effectively inhibited the growth of both the cell lines in dose and time dependant manner. Morphological apoptotic hallmarks such as chromatin condensation, fragmented chromatin were observedmore » in AO/EtBr staining. Moreover, ladder pattern of fragmented DNA observed in DNA gel electrophoresis proved the apoptotic activity of Ceranib 2 in breast cancer cell lines. The apoptotic events were associated with significant increase in the expression of pro-apoptotic genes (Bad, Bax and Bid) and down regulation of anti-apoptotic gene (Bcl 2). Interestingly, increase in sub G1 population of cell cycle phase analysis and elevated Annexin V positive cells after Ceranib 2 treatment substantiated its apoptotic activity in MCF 7 and MDA MB 231 cell lines. Thus, we report Ceranib 2 as a potent therapeutic agent against both ER{sup +} and ER{sup −} breast cancer cell lines. - Highlights: • Acid Ceramidase inhibitor, Ceranib 2 induced apoptosis in Breast cancer cell lines (MCF 7 and MDA MB 231 cell lines). • Apoptosis is mediated by DNA fragmentation and cell cycle arrest. • Ceranib 2 upregulated the expression of pro-apoptotic genes and down regulated anti-apoptotic gene expression. • More potent compared to the standard drug Tamoxifen.« less

A chimeric antigen receptor for TRAIL-receptor 1 induces apoptosis in various types of tumor cells.

PubMed

Kobayashi, Eiji; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Hamana, Hiroshi; Nakagawa, Hidetoshi; Jin, Aishun; Lin, Zhezhu; Muraguchi, Atsushi

2014-10-31

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its associated receptors (TRAIL-R/TR) are attractive targets for cancer therapy because TRAIL induces apoptosis in tumor cells through TR while having little cytotoxicity on normal cells. Therefore, many agonistic monoclonal antibodies (mAbs) specific for TR have been produced, and these induce apoptosis in multiple tumor cell types. However, some TR-expressing tumor cells are resistant to TR-specific mAb-induced apoptosis. In this study, we constructed a chimeric antigen receptor (CAR) of a TRAIL-receptor 1 (TR1)-specific single chain variable fragment (scFv) antibody (TR1-scFv-CAR) and expressed it on a Jurkat T cell line, the KHYG-1 NK cell line, and human peripheral blood lymphocytes (PBLs). We found that the TR1-scFv-CAR-expressing Jurkat cells killed target cells via TR1-mediated apoptosis, whereas TR1-scFv-CAR-expressing KHYG-1 cells and PBLs killed target cells not only via TR1-mediated apoptosis but also via CAR signal-induced cytolysis, resulting in cytotoxicity on a broader range if target cells than with TR1-scFv-CAR-expressing Jurkat cells. The results suggest that TR1-scFv-CAR could be a new candidate for cancer gene therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

Amphiregulin suppresses epithelial cell apoptosis in lipopolysaccharide-induced lung injury in mice

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

Ogata-Suetsugu, Saiko; Yanagihara, Toyoshi; Hamada, Naoki

Background and objective: As a member of the epidermal growth factor family, amphiregulin contributes to the regulation of cell proliferation. Amphiregulin was reported to be upregulated in damaged lung tissues in patients with chronic obstructive pulmonary disease and asthma and in lung epithelial cells in a ventilator-associated lung injury model. In this study, we investigated the effect of amphiregulin on lipopolysaccharide (LPS)-induced acute lung injury in mice. Methods: Acute lung injury was induced by intranasal instillation of LPS in female C57BL/6 mice, and the mice were given intraperitoneal injections of recombinant amphiregulin or phosphate-buffered saline 6 and 0.5 h before andmore » 3 h after LPS instillation. The effect of amphiregulin on apoptosis and apoptotic pathways in a murine lung alveolar type II epithelial cell line (LA-4 cells) were examined using flow cytometry and western blotting, respectively. Results: Recombinant amphiregulin suppressed epithelial cell apoptosis in LPS-induced lung injury in mice. Western blotting revealed that amphiregulin suppressed epithelial cell apoptosis by inhibiting caspase-8 activity. Conclusion: Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury treatment through its prevention of epithelial cell apoptosis. - Highlights: • Amphiregulin suppresses epithelial cell apoptosis in LPS-induced lung injury in mice. • The mechanism relies on inhibiting caspase-8 activity. • Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury.« less

Mitochondria-derived reactive oxygen species drive GANT61-induced mesothelioma cell apoptosis.

PubMed

Lim, Chuan Bian; Prêle, Cecilia M; Baltic, Svetlana; Arthur, Peter G; Creaney, Jenette; Watkins, D Neil; Thompson, Philip J; Mutsaers, Steven E

2015-01-30

Gli transcription factors of the Hedgehog (Hh) pathway have been reported to be drivers of malignant mesothelioma (MMe) cell survival. The Gli inhibitor GANT61 induces apoptosis in various cancer cell models, and has been associated directly with Gli inhibition. However various chemotherapeutics can induce cell death through generation of reactive oxygen species (ROS) but whether ROS mediates GANT61-induced apoptosis is unknown. In this study human MMe cells were treated with GANT61 and the mechanisms regulating cell death investigated. Exposure of MMe cells to GANT61 led to G1 phase arrest and apoptosis, which involved ROS but not its purported targets, GLI1 or GLI2. GANT61 triggered ROS generation and quenching of ROS protected MMe cells from GANT61-induced apoptosis. Furthermore, we demonstrated that mitochondria are important in mediating GANT61 effects: (1) ROS production and apoptosis were blocked by mitochondrial inhibitor rotenone; (2) GANT61 promoted superoxide formation in mitochondria; and (3) mitochondrial DNA-deficient LO68 cells failed to induce superoxide, and were more resistant to apoptosis induced by GANT61 than wild-type cells. Our data demonstrate for the first time that GANT61 induces apoptosis by promoting mitochondrial superoxide generation independent of Gli inhibition, and highlights the therapeutic potential of mitochondrial ROS-mediated anticancer drugs in MMe.

Targeting Death Receptor TRAIL-R2 by Chalcones for TRAIL-Induced Apoptosis in Cancer Cells

PubMed Central

Szliszka, Ewelina; Jaworska, Dagmara; Kłósek, Małgorzata; Czuba, Zenon P.; Król, Wojciech

2012-01-01

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in cancer cells without toxicity to normal cells. TRAIL binds to death receptors, TRAIL-R1 (DR4) and TRAIL-R2 (DR5) expressed on cancer cell surface and activates apoptotic pathways. Endogenous TRAIL plays an important role in immune surveillance and defense against cancer cells. However, as more tumor cells are reported to be resistant to TRAIL mediated death, it is important to search for and develop new strategies to overcome this resistance. Chalcones can sensitize cancer cells to TRAIL-induced apoptosis. We examined the cytotoxic and apoptotic effects of TRAIL in combination with four chalcones: chalcone, isobavachalcone, licochalcone A and xanthohumol on HeLa cancer cells. The cytotoxicity was measured by MTT and LDH assays. The apoptosis was detected using annexin V-FITC staining by flow cytometry and fluorescence microscopy. Death receptor expression was analyzed using flow cytometry. The decreased expression of death receptors in cancer cells may be the cause of TRAIL-resistance. Chalcones enhance TRAIL-induced apoptosis in HeLa cells through increased expression of TRAIL-R2. Our study has indicated that chalcones augment the antitumor activity of TRAIL and confirm their cancer chemopreventive properties. PMID:23203129

Endothelial microparticle uptake in target cells is annexin I/phosphatidylserine receptor dependent and prevents apoptosis.

PubMed

Jansen, Felix; Yang, Xiaoyan; Hoyer, Friedrich Felix; Paul, Kathrin; Heiermann, Nadine; Becher, Marc Ulrich; Abu Hussein, Nebal; Kebschull, Moritz; Bedorf, Jörg; Franklin, Bernardo S; Latz, Eicke; Nickenig, Georg; Werner, Nikos

2012-08-01

Endothelial microparticles (EMP) are released from activated or apoptotic cells, but their effect on target cells and the exact way of incorporation are largely unknown. We sought to determine the uptake mechanism and the biological effect of EMP on endothelial and endothelial-regenerating cells. EMP were generated from starved endothelial cells and isolated by ultracentrifugation. Caspase 3 activity assay and terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that EMP protect target endothelial cells against apoptosis in a dose-dependent manner. Proteomic analysis was performed to identify molecules contained in EMP, which might be involved in EMP uptake. Expression of annexin I in EMP was found and confirmed by Western blot, whereas the corresponding receptor phosphatidylserine receptor was present on endothelial target cells. Silencing either annexin I on EMP or phosphatidylserine receptor on target cells using small interfering RNA showed that the uptake of EMP by human coronary artery endothelial cells is annexin I/phosphatidylserine receptor dependent. Annexin I-downregulated EMP abrogated the EMP-mediated protection against apoptosis of endothelial target cells. p38 activation was found to mediate camptothecin-induced apoptosis. Finally, human coronary artery endothelial cells pretreated with EMP inhibited camptothecin-induced p38 activation. EMP are incorporated by endothelial cells in an annexin I/phosphatidylserine receptor-dependent manner and protect target cells against apoptosis. Inhibition of p38 activity is involved in EMP-mediated protection against apoptosis.

Targeted Knock-Down of miR21 Primary Transcripts Using snoMEN Vectors Induces Apoptosis in Human Cancer Cell Lines.

PubMed

Ono, Motoharu; Yamada, Kayo; Avolio, Fabio; Afzal, Vackar; Bensaddek, Dalila; Lamond, Angus I

2015-01-01

We have previously reported an antisense technology, 'snoMEN vectors', for targeted knock-down of protein coding mRNAs using human snoRNAs manipulated to contain short regions of sequence complementarity with the mRNA target. Here we characterise the use of snoMEN vectors to target the knock-down of micro RNA primary transcripts. We document the specific knock-down of miR21 in HeLa cells using plasmid vectors expressing miR21-targeted snoMEN RNAs and show this induces apoptosis. Knock-down is dependent on the presence of complementary sequences in the snoMEN vector and the induction of apoptosis can be suppressed by over-expression of miR21. Furthermore, we have also developed lentiviral vectors for delivery of snoMEN RNAs and show this increases the efficiency of vector transduction in many human cell lines that are difficult to transfect with plasmid vectors. Transduction of lentiviral vectors expressing snoMEN targeted to pri-miR21 induces apoptosis in human lung adenocarcinoma cells, which express high levels of miR21, but not in human primary cells. We show that snoMEN-mediated suppression of miRNA expression is prevented by siRNA knock-down of Ago2, but not by knock-down of Ago1 or Upf1. snoMEN RNAs colocalise with Ago2 in cell nuclei and nucleoli and can be co-immunoprecipitated from nuclear extracts by antibodies specific for Ago2.

Aspartame-induced apoptosis in PC12 cells.

PubMed

Horio, Yukari; Sun, Yongkun; Liu, Chuang; Saito, Takeshi; Kurasaki, Masaaki

2014-01-01

Aspartame is an artificial sweetner added to many low-calorie foods. The safety of aspartame remains controversial even though there are many studies on its risks. In this study, to understand the physiological effects of trace amounts of artificial sweetners on cells, the effects of aspartame on apoptosis were investigated using a PC12 cell system. In addition, the mechanism of apoptosis induced by aspartame in PC12 cells and effects on apoptotic factors such as cytochrome c, apoptosis-inducing factor, and caspase family proteins were studied by Western blotting and RT-PCR. Aspartame-induced apoptosis in PC12 cells in a dose-dependent manner. In addition, aspartame exposure increased the expressions of caspases 8 and 9, and cytochrome c. These results indicate that aspartame induces apoptosis mainly via mitochondrial pathway involved in apoptosis due to oxigen toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

miR-320a regulates cell proliferation and apoptosis in multiple myeloma by targeting pre-B-cell leukemia transcription factor 3

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

Lu, Yinghao; Department of Hematology, Affiliated Hospital of Guizhou Medical University, The Hematopoietic Stem Cell Transplant Center of Guizhou Province, Blood Diseases Diagnosis and Treatment Center of Guizhou Province, Guiyang, 550004, Guizhou Province; Wu, Depei, E-mail: wudepei@medmail.com.cn

2016-05-13

Aberrant expression of microRNAs (miRNAs) is implicated in cancer development and progression. While miR-320a is reported to be deregulated in many malignancy types, its biological role in multiple myeloma (MM) remains unclear. Here, we observed reduced expression of miR-320a in MM samples and cell lines. Ectopic expression of miR-320a dramatically suppressed cell viability and clonogenicity and induced apoptosis in vitro. Mechanistic investigation led to the identification of Pre-B-cellleukemia transcription factor 3 (PBX3) as a novel and direct downstream target of miR-320a. Interestingly, reintroduction of PBX3 abrogated miR-320a-induced MM cell growth inhibition and apoptosis. In a mouse xenograft model, miR-320a overexpression inhibitedmore » tumorigenicity and promoted apoptosis. Our findings collectively indicate that miR-320a inhibits cell proliferation and induces apoptosis in MM cells by directly targeting PBX3, supporting its utility as a novel and potential therapeutic agent for miRNA-based MM therapy. -- Highlights: •Expression of miR-320a in MM cell induces apoptosis in vitro. •miR-320a represses PBX3 via targeting specific sequences in the 3′UTR region. •Exogenous expression of PBX3 reverses the effects of miR-320a in inhibiting MM cell growth and promoting apoptosis. •Overexpression of miR-320a inhibits tumor growth and increases apoptosis in vivo.« less

Andrographolide Induces Cell Cycle Arrest and Apoptosis of Chondrosarcoma by Targeting TCF-1/SOX9 Axis.

PubMed

Zhang, Huan-Tian; Yang, Jie; Liang, Gui-Hong; Gao, Xue-Juan; Sang, Yuan; Gui, Tao; Liang, Zu-Jian; Tam, Man-Seng; Zha, Zhen-Gang

2017-12-01

Chondrosarcoma is the second most malignant bone tumor with poor prognosis and limited treatment options. Thus, development of more effective treatments has become urgent. Recently, natural compounds derived from medicinal plants have emerged as promising therapeutic options via targeting multiple key cellular molecules. Andrographolide (Andro) is such a compound, which has previously been shown to induce cell cycle arrest and apoptosis in several human cancers. However, the molecular mechanism through which Andro exerts its anti-cancer effect on chondrosarcoma remains to be elucidated. In the present study, we showed that Andro-induced G2/M cell cycle arrest of chondrosarcoma by fine-tuning the expressions of several cell cycle regulators such as p21, p27, and Cyclins, and that prolonged treatment of cells with Andro caused pronounced cell apoptosis. Remarkably, we found that SOX9 was highly expressed in poor-differentiated chondrosarcoma, and that knockdown of SOX9 suppressed chondrosarcoma cell growth. Further, our results showed that Andro dose-dependently down-regulated SOX9 expression in chondrosarcoma cells. Concomitantly, an inhibition of T cell factor 1 (TCF-1) mRNA expression and an enhancement of TCF-1 protein degradation by Andro were observed. In contrast, the expression and subcellular localization of β-catenin were not altered upon the treatment of Andro, suggesting that β-catenin might not function as the primary target of Andro. Additionally, we provided evidence that there was a mutual regulation between TCF-1 and SOX9 in chondrosarcoma cells. In conclusion, these results highlight the potential therapeutic effects of Andro in treatment of chondrosarcoma via targeting the TCF-1/SOX9 axis. J. Cell. Biochem. 118: 4575-4586, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Artesunate induces AIF-dependent apoptosis in A549 cells

NASA Astrophysics Data System (ADS)

Zhou, Chen-juan; Chen, Tong-Sheng

2012-03-01

Artesunate (ART), a semi-synthetic derivative of the sesquiterpene artemisinin extracted from the Chinese herb Artemisia annua, exerts a broad spectrum of clinical activity against human cancers. It has been shown that ART induces cancer cells death through apoptosis pathway. This study investigated whether ART treatment induced reactive oxygen species (ROS)-dependent cell death in the apoptosis fashion in human lung adenocarconoma A549 cell line and the proapoptotic protein apoptosis inducing factor (AIF) is involved in ART-induced apoptosis. Cells treated with ART exhibited typical apoptotic morphology as chromatin condensation, margination and shrunken nucleus. ART treatment also induced a loss of mitochondrial membrane potential and AIF release from mitochondria. Silencing AIF can remarkable attenuated ART-induced apoptosis. Collectively, ART induces apoptosis by caspase-independent intrinsic pathway in A549 cells.

Identification of apoptosis-related PLZF target genes

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

Bernardo, Maria Victoria; Yelo, Estefania; Gimeno, Lourdes

2007-07-27

The PLZF gene encodes a BTB/POZ-zinc finger-type transcription factor, involved in physiological development, proliferation, differentiation, and apoptosis. In this paper, we investigate proliferation, survival, and gene expression regulation in stable clones from the human haematopoietic K562, DG75, and Jurkat cell lines with inducible expression of PLZF. In Jurkat cells, but not in K562 and DG75 cells, PLZF induced growth suppression and apoptosis in a cell density-dependent manner. Deletion of the BTB/POZ domain of PLZF abrogated growth suppression and apoptosis. PLZF was expressed with a nuclear speckled pattern distinctively in the full-length PLZF-expressing Jurkat clones, suggesting that the nuclear speckled localizationmore » is required for PLZF-induced apoptosis. By microarray analysis, we identified that the apoptosis-inducer TP53INP1, ID1, and ID3 genes were upregulated, and the apoptosis-inhibitor TERT gene was downregulated. The identification of apoptosis-related PLZF target genes may have biological and clinical relevance in cancer typified by altered PLZF expression.« less

Tomentosin Induces Telomere Shortening and Caspase-Dependant Apoptosis in Cervical Cancer Cells.

PubMed

Merghoub, Nawel; El Btaouri, Hassan; Benbacer, Laila; Gmouh, Saïd; Trentesaux, Chantal; Brassart, Bertrand; Attaleb, Mohammed; Madoulet, Claudie; Wenner, Thomas; Amzazi, Saaid; Morjani, Hamid; El Mzibri, Mohamed

2017-07-01

Tomentosin, a natural sesquiterpene lactone purified from of Inula viscosa L., was investigated for its anti-proliferative, telomere shortening, and apoptotic effects on human cervical cancer HeLa and SiHa cell lines. Tomentosin was found to inhibit the growth of SiHa and HeLa cell lines in dose and time-dependent manner (IC 50 values of 7.10 ± 0.78 μM and 5.87 ± 0.36 μM, respectively after 96 h of treatment). As evidenced by TTAGGG telomere length assay, tomentosin target specifically the telomeric overhang lengthening. This was confirmed by the evaluation of the cytotoxic effects of tomentosin in the foetal fibroblast Wi38 and JW10 cells which were derived from Wi38 and express hTERT, the telomerase catalytic subunit. We found that JW10 cells are 4.7-fold more sensitive to tomentosin which argues for telomere as its specific target. Furthermore, we found that tomentosin mediate this cytotoxic effect by inducing apoptosis and cell cycle arrest at G2/M phase. Morphological features of treated cells, as evidenced by Hoechst 33324 staining, revealed that the cytotoxic effect was due to induction of apoptosis. This was accompanied by pro-caspase-3 cleavage, an increase in caspase-3 activity and a cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, tomentosin induced a decrease in mitochondrial membrane potential (ΔΨm) and an increase in reactive oxygen species (ROS), accompanied by a decrease in Bcl-2 expression. This indicates that tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. This study provides the first evidence that tomentosin targets telomere machinery and induces apoptosis in cervical cancer cells. The molecular mechanism underlying tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. J. Cell. Biochem. 118: 1689-1698, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Centchroman induces redox-dependent apoptosis and cell-cycle arrest in human endometrial cancer cells.

PubMed

Shyam, Hari; Singh, Neetu; Kaushik, Shweta; Sharma, Ramesh; Balapure, Anil K

2017-04-01

Centchroman (CC) or Ormeloxifene has been shown to induce apoptosis and cell cycle arrest in various types of cancer cells. This has, however, not been addressed for endometrial cancer cells where its (CC) mechanism of action remains unclear. This study focuses on the basis of antineoplasticity of CC by blocking the targets involved in the cell cycle, survival and apoptosis in endometrial cancer cells. Ishikawa Human Endometrial Cancer Cells were cultured under estrogen deprived medium, exposed to CC and analyzed for proliferation and apoptosis. Additionally, we also analyzed oxidative stress induced by CC. Cell viability studies confirmed the IC 50 of CC in Ishikawa cells to be 20 µM after 48 h treatment. CC arrests the cells in G0/G1 phase through cyclin D1 and cyclin E mediated pathways. Phosphatidylserine externalization, nuclear morphology changes, DNA fragmentation, PARP cleavage, and alteration of Bcl-2 family protein expression clearly suggest ongoing apoptosis in the CC treated cells. Activation of caspase 3 & 9, up-regulation of AIF and inhibition of apoptosis by z-VAD-fmk clearly explains the participation of the intrinsic pathway of programmed cell death. Further, the increase of ROS, loss of MMP, inhibition of antioxidant (MnSOD, Cu/Zn-SOD and GST) and inhibition of apoptosis with L-NAC suggests CC induced oxidative stress leading to apoptosis via mitochondria mediated pathway. Therefore, CC could be a potential therapeutic agent for the treatment of Endometrial Cancer adjunct to its utility as a contraceptive and an anti-breast cancer agent.

Activator protein 1 promotes gemcitabine-induced apoptosis in pancreatic cancer by upregulating its downstream target Bim.

PubMed

Ren, Xiaoxia; Zhao, Wenjing; Du, Yongxing; Zhang, Taiping; You, Lei; Zhao, Yupei

2016-12-01

Gemcitabine is a commonly used chemotherapy drug in pancreatic cancer. The function of activator protein 1 (AP-1) is cell-specific, and its function depends on the expression of other complex members. In the present study, we added gemcitabine to the media of Panc-1 and SW1990 cells at clinically achieved concentrations (10 µM). Compared with constitutive c-Fos expression, c-Jun expression increased in a dose-dependent manner upon gemcitabine treatment. c-Jun overexpression increased gemcitabine-induced apoptosis through Bim activation, while cell apoptosis and Bim expression decreased following c-Jun knockdown. Furthermore, gemcitabine-induced apoptosis and Bim levels decreased when c-Jun phosphorylation was blocked by SP600125. Our findings suggest that c-Jun, which is a member of the AP-1 complex, functions in gemcitabine-induced apoptosis by regulating its downstream target Bim in pancreatic cancer cells.

Prevention of gentamicin-induced apoptosis with the mitochondria-targeted antioxidant mitoquinone.

PubMed

Ojano-Dirain, Carolyn P; Antonelli, Patrick J

2012-11-01

Antioxidants have been shown to protect against aminoglycoside-induced hearing loss. Mitoquinone (MitoQ) is a mitochondria-targeted derivative of the antioxidant ubiquinone. MitoQ is attached to a lipophilic triphenylphosphonium (TPP) cation, which enables its accumulation inside the mitochondria several hundred-fold over the untargeted antioxidant. The goals of this study were to determine if MitoQ attenuates gentamicin-induced activation of caspase-3/7 activity as a marker of apoptosis and to determine if MitoQ impacts aminoglycoside antimicrobial efficacy. Prospective and controlled. Antibiotic efficacy and minimum inhibitory concentrations (MICs) of gentamicin against three strains each of Staphylococcus aureus, Haemophilus influenzae, and Pseudomonas aeruginosa were evaluated with and without MitoQ using broth dilution methods. Apoptosis was assessed by caspase-3/7 activity in untreated HEI-OC1 cells and cells exposed to 2 mM gentamicin for 24 hours, with and without a 24-hour preincubation with 0.5 μM each of MitoQ, idebenone (an untargeted ubiquinone), or decylTPP (positive control). Gentamicin MICs for P aeruginosa and H influenzae were not affected by MitoQ at pharmacological levels. MICs for S aureus were enhanced by MitoQ. Cell viability was significantly lower in the gentamicin-treated cells. A significant increase in caspase-3/7 activity was observed in cells treated with gentamicin or with idebenone + gentamicin (P = .005). Preincubation with MitoQ decreased the gentamicin-induced apoptosis of HEI-OC1 cells to a greater extent compared to idebenone (P = .002). MitoQ attenuates gentamicin-induced apoptosis in HEI-OC1 cells and does not compromise gentamicin antibiotic efficacy. MitoQ holds promise as a means of preventing aminoglycoside ototoxicity. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

N-Desmethyldauricine Induces Autophagic Cell Death in Apoptosis-Defective Cells via Ca2+ Mobilization.

PubMed

Law, Betty Y K; Mok, Simon W F; Chen, Juan; Michelangeli, Francesco; Jiang, Zhi-Hong; Han, Yu; Qu, Yuan Q; Qiu, Alena C L; Xu, Su-Wei; Xue, Wei-Wei; Yao, Xiao-Jun; Gao, Jia Y; Javed, Masood-Ul-Hassan; Coghi, Paolo; Liu, Liang; Wong, Vincent K W

2017-01-01

Resistance of cancer cells to chemotherapy remains a significant problem in oncology. Mechanisms regulating programmed cell death, including apoptosis, autophagy or necrosis, in the treatment of cancers have been extensively investigated over the last few decades. Autophagy is now emerging as an important pathway in regulating cell death or survival in cancer therapy. Recent studies demonstrated variety of natural small-molecules could induce autophagic cell death in apoptosis-resistant cancer cells, therefore, discovery of novel autophagic enhancers from natural products could be a promising strategy for treatment of chemotherapy-resistant cancer. By computational virtual docking analysis, biochemical assays, and advanced live-cell imaging techniques, we have identified N -desmethyldauricine (LP-4), isolated from rhizoma of Menispermum dauricum DC as a novel inducer of autophagy. LP-4 was shown to induce autophagy via the Ulk-1-PERK and Ca 2+ /Calmodulin-dependent protein kinase kinase β (CaMKKβ)-AMPK-mTOR signaling cascades, via mobilizing calcium release through inhibition of SERCA, and importantly, lead to autophagic cell death in a panel of cancer cells, apoptosis-defective and apoptosis-resistant cells. Taken together, this study provides detailed insights into the cytotoxic mechanism of a novel autophagic compound that targeting the apoptosis resistant cancer cells, and new implication on drug discovery from natural products for drug resistant cancer therapy.

Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma.

PubMed

Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Guan, Shan; Woodfield, Sarah E; Vasudevan, Sanjeev A; Tao, Ling; Pang, Jonathan C; Lu, Jiaxiong; Zhang, Huiyuan; Zhang, Fuchun; Yang, Jianhua

2017-01-03

Neuroblastoma is the most common extracranial solid tumor in children. The ErbB family of proteins is a group of receptor tyrosine kinases that promote the progression of various malignant cancers including neuroblastoma. Thus, targeting them with small molecule inhibitors is a promising strategy for neuroblastoma therapy. In this study, we investigated the anti-tumor effect of afatinib, an irreversible inhibitor of members of the ErbB family, on neuroblastoma. We found that afatinib suppressed the proliferation and colony formation ability of neuroblastoma cell lines in a dose-dependent manner. Afatinib also induced apoptosis and blocked EGF-induced activation of PI3K/AKT/mTOR signaling in all neuroblastoma cell lines tested. In addition, afatinib enhanced doxorubicin-induced cytotoxicity in neuroblastoma cells, including the chemoresistant LA-N-6 cell line. Finally, afatinib exhibited antitumor efficacy in vivo by inducing apoptosis in an orthotopic xenograft neuroblastoma mouse model. Taken together, these results show that afatinib inhibits neuroblastoma growth both in vitro and in vivo by suppressing EGFR-mediated PI3K/AKT/mTOR signaling. Our study supports the idea that EGFR is a potential therapeutic target in neuroblastoma. And targeting ErbB family protein kinases with small molecule inhibitors like afatinib alone or in combination with doxorubicin is a viable option for treating neuroblastoma.

Apigenin induces apoptosis by targeting inhibitor of apoptosis proteins and Ku70–Bax interaction in prostate cancer

PubMed Central

Shukla, Sanjeev; Fu, Pingfu; Gupta, Sanjay

2014-01-01

Dysfunction of the apoptotic pathway in prostate cancer cells confers apoptosis resistance towards various therapies. A novel strategy to overcome resistance is to directly target the apoptotic pathway in cancer cells. Apigenin, an anticancer agent, selectively toxic to cancer cells induces cell cycle arrest and apoptosis through mechanisms which are not fully explored. In the present study we provide novel insight into the mechanisms of apoptosis induction by apigenin. Treatment of androgen-refractory human prostate cancer PC-3 and DU145 cells with apigenin resulted in dose-dependent suppression of XIAP, c-IAP1, c-IAP2 and survivin protein levels. Apigenin treatment resulted in significant decrease in cell viability and apoptosis induction with the increase of cytochrome C in time-dependent manner. These effects of apigenin were accompanied by decrease in Bcl-xL and Bcl-2 and increase in the active form of Bax protein. The apigenin-mediated increase in Bax was due to dissociation of Bax from Ku70 which is essential for apoptotic activity of Bax. Apigenin treatment resulted in the inhibition of class I histone deacetylases and HDAC1 protein expression, thereby increasing the acetylation of Ku70 and the dissociation of Bax resulting in apoptosis of cancer cells. Furthermore, apigenin significantly reduced HDAC1 occupancy at the XIAP promoter, suggesting that histone deacetylation might be critical for XIAP downregulation. These results suggest that apigenin targets inhibitor of apoptosis proteins and Ku70–Bax interaction in the induction of apoptosis in prostate cancer cells and in athymic nude mouse xenograft model endorsing its in vivo efficacy. PMID:24563225

Oxidative Stress-Responsive Apoptosis Inducing Protein (ORAIP) Plays a Critical Role in High Glucose-Induced Apoptosis in Rat Cardiac Myocytes and Murine Pancreatic β-Cells.

PubMed

Yao, Takako; Fujimura, Tsutomu; Murayama, Kimie; Okumura, Ko; Seko, Yoshinori

2017-10-18

We previously identified a novel apoptosis-inducing humoral factor in the conditioned medium of hypoxic/reoxygenated-cardiac myocytes. We named this novel post-translationally-modified secreted-form of eukaryotic translation initiation factor 5A Oxidative stress-Responsive Apoptosis-Inducing Protein (ORAIP). We confirmed that myocardial ischemia/reperfusion markedly increased plasma ORAIP levels and rat myocardial ischemia/reperfusion injury was clearly suppressed by neutralizing anti-ORAIP monoclonal antibodies (mAbs) in vivo. In this study, to investigate the mechanism of cell injury of cardiac myocytes and pancreatic β-cells involved in diabetes mellitus (DM), we analyzed plasma ORAIP levels in DM model rats and the role of ORAIP in high glucose-induced apoptosis of cardiac myocytes in vitro. We also examined whether recombinant-ORAIP induces apoptosis in pancreatic β-cells. Plasma ORAIP levels in DM rats during diabetic phase were about 18 times elevated as compared with non-diabetic phase. High glucose induced massive apoptosis in cardiac myocytes (66.2 ± 2.2%), which was 78% suppressed by neutralizing anti-ORAIP mAb in vitro. Furthermore, recombinant-ORAIP clearly induced apoptosis in pancreatic β-cells in vitro. These findings strongly suggested that ORAIP plays a pivotal role in hyperglycemia-induced myocardial injury and pancreatic β-cell injury in DM. ORAIP will be a biomarker and a critical therapeutic target for cardiac injury and progression of DM itself.

[Harringtonine induces apoptosis in NB4 cells through down-regulation of Mcl-1].

PubMed

Wu, Chunxiao; Shen, Hongqiang; Xia, Dajing

2013-07-01

To investigate the growth inhibition effect, cytotoxicity and apoptotic induction of harringtonine (HT) in human acute promyelocytic leukemia (APL) NB4 cells,and the related mechanism. NB4 cells were treated with HT. Total cell numbers were counted by hemocytometer, and cell viabilities were determined by trypan blue exclusion. Apoptotic cells were determined by fluorescence microscopy and FACS after staining with AO and EB or PI, respectively. The cleavage of PARP and the activation of Bax and the expression of anti-apoptotic proteins were determined by Western Blot. siRNA was used to silence the expression of target genes. Primary cells were isolated following Ficoll-Hypaque density gradient centrifugation method. HT inhibited cell growth and induced apoptosis of NB4 cells in a dose- and time-dependent manner. Apoptosis induced by HT was correlated with the down-regulation of Mcl-1 and the cleavage of PARP, while HT did not affect the protein level of Bax and Bak or change the protein level of Bcl-2. The silence of Bcl-XL sensitized HT-induced apoptosis in NB4 cells.Apoptosis induced by HT in primarily cultured APL cells was also correlated with the down-regulation of Mcl-1. HT inhibits cell growth and induces apoptosis in NB4 cells and primarily cultured APL cells, which may be associated with down-regulation of Mcl-1.

Sulphoraphane, a naturally occurring isothiocyanate induces apoptosis in breast cancer cells by targeting heat shock proteins

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

Sarkar, Ruma; Mukherjee, Sutapa; Biswas, Jaydip

Highlights: Black-Right-Pointing-Pointer HSPs (27, 70 and 90) and HSF1 are overexpressed in MCF-7 and MDA-MB-231 cells. Black-Right-Pointing-Pointer Sulphoraphane, a natural isothiocyanate inhibited HSPs and HSF1 expressions. Black-Right-Pointing-Pointer Inhibition of HSPs and HSF1 lead to regulation of apoptotic proteins. Black-Right-Pointing-Pointer Alteration of apoptotic proteins activate of caspases particularly caspase 3 and 9 leading to induction of apoptosis. Black-Right-Pointing-Pointer Alteration of apoptotic proteins induce caspases leading to induction of apoptosis. -- Abstract: Heat shock proteins (HSPs) are involved in protein folding, aggregation, transport and/or stabilization by acting as a molecular chaperone, leading to inhibition of apoptosis by both caspase dependent and/or independentmore » pathways. HSPs are overexpressed in a wide range of human cancers and are implicated in tumor cell proliferation, differentiation, invasion and metastasis. HSPs particularly 27, 70, 90 and the transcription factor heat shock factor1 (HSF1) play key roles in the etiology of breast cancer and can be considered as potential therapeutic target. The present study was designed to investigate the role of sulphoraphane, a natural isothiocyanate on HSPs (27, 70, 90) and HSF1 in two different breast cancer cell lines MCF-7 and MDA-MB-231 cells expressing wild type and mutated p53 respectively, vis-a-vis in normal breast epithelial cell line MCF-12F. It was furthermore investigated whether modulation of HSPs and HSF1 could induce apoptosis in these cells by altering the expressions of p53, p21 and some apoptotic proteins like Bcl-2, Bax, Bid, Bad, Apaf-1 and AIF. Sulphoraphane was found to down-regulate the expressions of HSP70, 90 and HSF1, though the effect on HSP27 was not pronounced. Consequences of HSP inhibition was upregulation of p21 irrespective of p53 status. Bax, Bad, Apaf-1, AIF were upregulated followed by down-regulation of Bcl-2 and this effect was

Chrysin inhibited tumor glycolysis and induced apoptosis in hepatocellular carcinoma by targeting hexokinase-2.

PubMed

Xu, Dong; Jin, Junzhe; Yu, Hao; Zhao, Zheming; Ma, Dongyan; Zhang, Chundong; Jiang, Honglei

2017-03-20

Hexokinase-2(HK-2) plays dual roles in glucose metabolism and mediation of cell apoptosis, making it an attractive target for cancer therapy. Chrysin is a natural flavone found in plant extracts which are widely used as herb medicine in China. In the present study, we investigated the antitumor activity of chrysin against hepatocellular carcinoma (HCC) and the role of HK-2 played for chrysin to exert its function. The expression of HK-2 in HCC cell line and tumor tissue was examined by western blotting and immunohistochemistry staining. The activities of chrysin against HCC cell proliferation and tumor glycolysis were investigated. Chrysin-induced apoptosis was analyzed by flow cytometry. The effect of chrysin on HK-2 expression and the underlying mechanisms by which induced HCC cell apoptosis were studied. In HK-2 exogenous overexpression cell, the changes of chrysin-induced cell apoptosis and glycolysis suppression were investigated. HCC cell xenograft model was used to confirm the antitumor activity of chrysin in vivo and the effect on HK-2 was tested in chrysin-treated tumor tissue. In contrast with normal cell lines and tissue, HK-2 expression was substantially elevated in the majority of tested HCC cell lines and tumor tissue. Owing to the decrease of HK-2 expression, glucose uptake and lactate production in HCC cells were substantially inhibited after exposure to chrysin. After chrysin treatment, HK-2 which combined with VDAC-1 on mitochondria was significantly declined, resulting in the transfer of Bax from cytoplasm to mitochondria and induction of cell apoptosis. Chrysin-mediated cell apoptosis and glycolysis suppression were dramatically impaired in HK-2 exogenous overexpression cells. Tumor growth in HCC xenograft models was significantly restrained after chrysin treatment and significant decrease of HK-2 expression was observed in chrysin-treated tumor tissue. Through suppressing glycolysis and inducing apoptosis in HCC, chrysin, or its derivative has

Verocytotoxin-induced apoptosis of human microvascular endothelial cells.

PubMed

Pijpers, A H; van Setten, P A; van den Heuvel, L P; Assmann, K J; Dijkman, H B; Pennings, A H; Monnens, L A; van Hinsbergh, V W

2001-04-01

The pathogenesis of the epidemic form of hemolytic uremic syndrome is characterized by endothelial cell damage. In this study, the role of apoptosis in verocytotoxin (VT)-mediated endothelial cell death in human glomerular microvascular endothelial cells (GMVEC), human umbilical vein endothelial cells, and foreskin microvascular endothelial cells (FMVEC) was investigated. VT induced apoptosis in GMVEC and human umbilical vein endothelial cells when the cells were prestimulated with the inflammatory mediator tumor necrosis factor-alpha (TNF-alpha). FMVEC displayed strong binding of VT and high susceptibility to VT under basal conditions, which made them suitable for the study of VT-induced apoptosis without TNF-alpha interference. On the basis of functional (flow cytometry and immunofluorescence microscopy using FITC-conjugated annexin V and propidium iodide), morphologic (transmission electron microscopy), and molecular (agarose gel electrophoresis of cellular DNA fragments) criteria, it was documented that VT induced programmed cell death in microvascular endothelial cells in a dose- and time-dependent manner. Furthermore, whereas partial inhibition of protein synthesis by VT was associated with a considerable number of apoptotic cells, comparable inhibition of protein synthesis by cycloheximide was not. This suggests that additional pathways, independent of protein synthesis inhibition, may be involved in VT-mediated apoptosis in microvascular endothelial cells. Specific inhibition of caspases by Ac-Asp-Glu-Val-Asp-CHO, but not by Ac-Tyr-Val-Ala-Asp-CHO, was accompanied by inhibition of VT-induced apoptosis in FMVEC and TNF-alpha-treated GMVEC. These data indicate that VT can induce apoptosis in human microvascular endothelial cells.

UVC-induced apoptosis in Dubca cells is independent of JNK activation and p53{sup Ser-15} phosphorylation

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

Chathoth, Shahanas; Thayyullathil, Faisal; Hago, Abdulkader

2009-06-12

Ultraviolet C (UVC) irradiation in mammalian cell lines activates a complex signaling network that leads to apoptosis. By using Dubca cells as a model system, we report the presence of a UVC-induced apoptotic pathway that is independent of c-Jun N-terminal kinases (JNKs) activation and p53 phosphorylation at Ser{sup 15}. Irradiation of Dubca cells with UVC results in a rapid JNK activation and phosphorylation of its downstream target c-Jun, as well as, phosphorylation of activating transcription factor 2 (ATF2). Pre-treatment with JNK inhibitor, SP600125, inhibited UVC-induced c-Jun phosphorylation without preventing UVC-induced apoptosis. Similarly, inhibition of UVC-induced p53 phosphorylation did not preventmore » Dubca cell apoptosis, suggesting that p53{sup Ser-15} phosphorylation is not associated with UVC-induced apoptosis signaling. The pan-caspase inhibitor z-VAD-fmk inhibited UVC-induced PARP cleavage, DNA fragmentation, and ultimately apoptosis of Dubca cells. Altogether, our study clearly indicates that UVC-induced apoptosis is independent of JNK and p53 activation in Dubca cells, rather, it is mediated through a caspase dependent pathway. Our findings are not in line with the ascribed critical role for JNKs activation, and downstream phosphorylation of targets such as c-Jun and ATF2 in UVC-induced apoptosis.« less

Microplasma Induced Cell Morphological Changes and Apoptosis of Ex Vivo Cultured Human Anterior Lens Epithelial Cells – Relevance to Capsular Opacification

PubMed Central

Hojnik, Nataša; Filipič, Gregor; Lazović, Saša; Vesel, Alenka; Primc, Gregor; Mozetič, Miran; Hawlina, Marko; Petrovski, Goran; Cvelbar, Uroš

2016-01-01

Inducing selective or targeted cell apoptosis without affecting large number of neighbouring cells remains a challenge. A plausible method for treatment of posterior capsular opacification (PCO) due to remaining lens epithelial cells (LECs) by reactive chemistry induced by localized single electrode microplasma discharge at top of a needle-like glass electrode with spot size ~3 μm is hereby presented. The focused and highly-localized atmospheric pressure microplasma jet with electrode discharge could induce a dose-dependent apoptosis in selected and targeted individual LECs, which could be confirmed by real-time monitoring of the morphological and structural changes at cellular level. Direct cell treatment with microplasma inside the medium appeared more effective in inducing apoptosis (caspase 8 positivity and DNA fragmentation) at a highly targeted cell level compared to treatment on top of the medium (indirect treatment). Our results show that single cell specific micropipette plasma can be used to selectively induce demise in LECs which remain in the capsular bag after cataract surgery and thus prevent their migration (CXCR4 positivity) to the posterior lens capsule and PCO formation. PMID:27832099

Inhibitory Effect of Lycopene on Amyloid-β-Induced Apoptosis in Neuronal Cells.

PubMed

Hwang, Sinwoo; Lim, Joo Weon; Kim, Hyeyoung

2017-08-16

Alzheimer's disease (AD) is a fatal neurodegenerative disease. Brain amyloid-β deposition is a crucial feature of AD, causing neuronal cell death by inducing oxidative damage. Reactive oxygen species (ROS) activate NF-κB, which induces expression of Nucling. Nucling is a pro-apoptotic factor recruiting the apoptosome complex. Lycopene is an antioxidant protecting from oxidative stress-induced cell damage. We investigated whether lycopene inhibits amyloid-β-stimulated apoptosis through reducing ROS and inhibiting mitochondrial dysfunction and NF-κB-mediated Nucling expression in neuronal SH-SY5Y cells. We prepared cells transfected with siRNA for Nucling or nontargeting control siRNA to determine the role of Nucling in amyloid-β-induced apoptosis. The amyloid-β increased intracellular and mitochondrial ROS levels, apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), NF-kB activation and Nucling expression, while cell viability, mitochondrial membrane potential, and oxygen consumption rate decreased in SH-SY5Y cells. Lycopene inhibited these amyloid-β-induced alterations. However, amyloid-β did not induce apoptosis, determined by cell viability and apoptotic indices (p53, Bax/Bcl-2 ratio, caspase-3 cleavage), in the cells transfected with siRNA for Nucling. Lycopene inhibited apoptosis by reducing ROS, and by inhibiting mitochondrial dysfunction and NF-κB-target gene Nucling expression in neuronal cells. Lycopene may be beneficial for preventing oxidative stress-mediated neuronal death in patients with neurodegeneration.

Infrasound sensitizes human glioblastoma cells to cisplatin-induced apoptosis.

PubMed

Rachlin, Kenneth; Moore, Dan H; Yount, Garret

2013-11-01

The development of nontoxic agents that can selectively enhance the cytotoxicity of chemotherapy is an important aim in oncology. This study evaluates the ability of infrasound exposure to sensitize glioblastoma cells to cisplatin-induced apoptosis. The infrasound was delivered using a device designed to replicate the unique infrasound emissions measured during external Qigong treatments. Human glioblastoma cell lines harboring wild-type p53 (U87) or mutant p53 (U251, SF210, and SF188) were treated in culture with cisplatin, infrasound emissions, or the combination of the 2 agents. Induction of apoptosis was quantified after 24 hours by flow cytometry following annexin V/propidium iodide staining. Infrasound emissions alone, delivered at moderate levels (~10 mPa) with dynamic frequency content (7-13 Hz), did not induce apoptosis, yet combining infrasound with cisplatin augmented the induction of apoptosis by cisplatin in all the 4 cell lines (P < .05). Increased cellular uptake of the fluorophore calcein associated with infrasound exposure was quantified by fluorescence microscopy as well as flow cytometry, demonstrating increased cell membrane permeability. The 4 cell lines differed in the degree to which infrasound exposure increased calcein uptake, and these differences were predictive of the extent to which infrasound enhanced cisplatin-induced apoptosis. When exposed to specific frequencies, membrane permeabilization also appeared to be differentially responsive for each cell line, suggesting the potential for selective targeting of tissue types using isolated infrasonic frequencies. Additionally, the pressure amplitudes used in this study were several orders of magnitude less than those used in similar studies involving ultrasound and shock waves. The results of this study provide support for using infrasound to enhance the chemotherapeutic effects of cisplatin in a clinical setting.

Knockdown of peroxiredoxin V increases glutamate‑induced apoptosis in HT22 hippocampal neuron cells.

PubMed

Shen, Gui-Nan; Liu, Lei; Feng, Li; Jin, Yu; Jin, Mei-Hua; Han, Ying-Hao; Jin, Cheng-Hao; Jin, Yong-Zhe; Lee, Dong-Soek; Kwon, Tae Ho; Cui, Yu-Dong; Sun, Hu-Nan

2018-06-01

High concentrations of glutamate may mediate neuronal cell apoptosis by increasing intracellular reactive oxygen species (ROS) levels. Peroxiredoxin V (Prx V), a member of the Prx family, serves crucial roles in protecting cells from oxidative stress. The present study investigated the regulatory effect of Prx V on glutamate‑induced effects on viability and apoptosis in HT22 cells. Western blotting was used for protein expression analysis and Annexin V/PI staining and flow cytometry for determination of apoptosis. The results demonstrated that glutamate may ROS‑dependently increase HT22 cell apoptosis and upregulate Prx V protein levels. Furthermore, knockdown of Prx V protein expression with a lentivirus significantly enhanced HT22 cell apoptosis mediated by glutamate, which was reversed by inhibition of ROS with N‑acetyl‑L‑cysteine. Inhibiting the extracellular signal‑regulated kinase (ERK) signaling pathway with PD98059, a specific inhibitor for ERK phosphorylation, markedly decreased glutamate‑induced HT22 cell apoptosis in Prx V knockdown cells, indicating the potential involvement of ERK signaling in glutamate‑induced HT22 cell apoptosis. In addition, an increase in nuclear apoptosis‑inducing factor was observed in Prx V knockdown HT22 cells following glutamate treatment, compared with mock cells, whereas no differences in B‑cell lymphoma‑2 and cleaved‑caspase‑3 protein expression levels were observed between mock and Prx V knockdown cells. The results of the present study indicated that Prx V may have potential as a therapeutic molecular target for glutamate‑induced neuronal cell death and provide novel insight into the role of Prx V in oxidative‑stress induced neuronal cell death.

Vimentin Is Involved in Peptidylarginine Deiminase 2-Induced Apoptosis of Activated Jurkat Cells

PubMed Central

Hsu, Pei-Chen; Liao, Ya-Fan; Lin, Chin-Li; Lin, Wen-Hao; Liu, Guang-Yaw; Hung, Hui-Chih

2014-01-01

Peptidylarginine deiminase type 2 (PADI2) deiminates (or citrullinates) arginine residues in protein to citrulline residues in a Ca2+-dependent manner, and is found in lymphocytes and macrophages. Vimentin is an intermediate filament protein and a well-known substrate of PADI2. Citrullinated vimentin is found in ionomycin-induced macrophage apoptosis. Citrullinated vimentin is the target of anti-Sa antibodies, which are specific to rheumatoid arthritis, and play a critical role in the pathogenesis of the disease. To investigate the role of PADI2 in apoptosis, we generated a Jurkat cell line that overexpressed the PADI2 transgene from a tetracycline-inducible promoter, and used a combination of 12-O-tetradecanoylphorbol-13-acetate and ionomycin to activate Jurkat cells. We found that PADI2 overexpression reduced the cell viability of activated Jurkat cells in a dose- and time-dependent manner. The PADI2-overexpressed and -activated Jurkat cells presented typical manifestations of apoptosis, and exhibited greater levels of citrullinated proteins, including citrullinated vimentin. Vimentin overexpression rescued a portion of the cells from apoptosis. In conclusion, PADI2 overexpression induces apoptosis in activated Jurkat cells. Vimentin is involved in PADI2-induced apoptosis. Moreover, PADI2-overexpressed Jurkat cells secreted greater levels of vimentin after activation, and expressed more vimentin on their cell surfaces when undergoing apoptosis. Through artificially highlighting PADI2 and vimentin, we demonstrated that PADI2 and vimentin participate in the apoptotic mechanisms of activated T lymphocytes. The secretion and surface expression of vimentin are possible ways of autoantigen presentation to the immune system. PMID:24850148

Cancerous inhibitor of protein phosphatase 2A determines bortezomib-induced apoptosis in leukemia cells

PubMed Central

Liu, Chun-Yu; Shiau, Chung-Wai; Kuo, Hsin-Yu; Huang, Hsiang-Po; Chen, Ming-Huang; Tzeng, Cheng-Hwai; Chen, Kuen-Feng

2013-01-01

The multiple cellular targets affected by proteasome inhibition implicate a potential role for bortezomib, a first-in-class proteasome inhibitor, in enhancing antitumor activities in hematologic malignancies. Here, we examined the antitumor activity and drug targets of bortezomib in leukemia cells. Human leukemia cell lines were used for in vitro studies. Drug efficacy was evaluated by apoptosis assays and associated molecular events assessed by Western Blot. Gene silencing was performed by small interference RNA. Drug was tested in vivo in xenograft models of human leukemia cell lines and in primary leukemia cells. Clinical samples were assessed by immunohistochemical staining. Bortezomib differentially induced apoptosis in leukemia cells that was independent of its proteasome inhibition. Cancerous inhibitor of protein phosphatase 2A, a cellular inhibitor of protein phosphatase 2A, mediated the apoptotic effect of bortezomib. Bortezomib increased protein phosphatase 2A activity in sensitive leukemia cells (HL-60 and KG-1), but not in resistant cells (MOLT-3 and K562). Bortezomib’s downregulation of cancerous inhibitor of protein phosphatase 2A and phospho-Akt correlated with its drug sensitivity. Furthermore, cancerous inhibitor of protein phosphatase 2A negatively regulated protein phosphatase 2A activity. Ectopic expression of CIP2A up-regulated phospho-Akt and protected HL-60 cells from bortezomib-induced apoptosis, whereas silencing CIP2A overcame the resistance to bortezomib-induced apoptosis in MOLT3 and K562 cells. Importantly, bortezomib exerted in vivo antitumor activity in HL-60 xenografted tumors and induced cell death in some primary leukemic cells. Cancerous inhibitor of protein phosphatase 2A was expressed in leukemic blasts from bone marrow samples. Cancerous inhibitor of protein phosphatase 2A plays a major role in mediating bortezomib-induced apoptosis in leukemia cells. PMID:22983581

Mangiferin induces apoptosis in multiple myeloma cell lines by suppressing the activation of nuclear factor kappa B-inducing kinase.

PubMed

Takeda, Tomoya; Tsubaki, Masanobu; Kino, Toshiki; Yamagishi, Misa; Iida, Megumi; Itoh, Tatsuki; Imano, Motohiro; Tanabe, Genzoh; Muraoka, Osamu; Satou, Takao; Nishida, Shozo

2016-05-05

Mangiferin is a naturally occurring glucosyl xanthone, which induces apoptosis in various cancer cells. However, the molecular mechanism underlying mangiferin-induced apoptosis has not been clarified thus far. Therefore, we examined the molecular mechanism underlying mangiferin-induced apoptosis in multiple myeloma (MM) cell lines. We found that mangiferin decreased the viability of MM cell lines in a concentration-dependent manner. We also observed an increased number of apoptotic cells, caspase-3 activation, and a decrease in the mitochondrial membrane potential. In addition, mangiferin inhibited the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated inhibitor kappa B (IκB) and increased the expression of IκB protein, whereas no changes were observed in the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase 1/2 (JNK1/2), and mammalian target of rapamycin (mTOR). The molecular mechanism responsible for mangiferin-induced inhibition of nuclear translocation of NF-κB was a decrease in the expression of phosphorylated NF-κB-inducing kinase (NIK). Moreover, mangiferin decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, and Bcl-xL proteins. Knockdown of NIK expression showed results similar to those observed with mangiferin treatment. Our results suggest that mangiferin induces apoptosis through the inhibition of nuclear translocation of NF-κB by suppressing NIK activation in MM cell lines. Our results provide a new insight into the molecular mechanism of mangiferin-induced apoptosis. Importantly, since the number of reported NIK inhibitors is limited, mangiferin, which targets NIK, may be a potential anticancer agent for the treatment of MM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

MicroRNA-1 promotes apoptosis of hepatocarcinoma cells by targeting apoptosis inhibitor-5 (API-5).

PubMed

Li, Dong; Liu, Yu; Li, Hua; Peng, Jing-Jing; Tan, Yan; Zou, Qiang; Song, Xiao-Feng; Du, Min; Yang, Zheng-Hui; Tan, Yong; Zhou, Jin-Jun; Xu, Tao; Fu, Zeng-Qiang; Feng, Jian-Qiong; Cheng, Peng; chen, Tao; Wei, Dong; Su, Xiao-Mei; Liu, Huan-Yi; Qi, Zhong-Chun; Tang, Li-Jun; Wang, Tao; Guo, Xin; Hu, Yong-He; Zhang, Tao

2015-01-02

Although microRNA-1 (miR-1) is a known liver cancer suppressor, the role of miR-1 in apoptosis of hepatoma cells has remained largely unknown. Our study shows that ectopic miR-1 overexpression induced apoptosis of liver hepatocellular carcinoma (HepG2) cells. Apoptosis inhibitor 5 (API-5) was found to be a potential regulator of miR-1 induced apoptosis, using a bioinformatics approach. Furthermore, an inverse relationship between miR-1 and API-5 expression was observed in human liver cancer tissues and adjacent normal liver tissues. Negative regulation of API-5 expression by miR-1 was demonstrated to promote apoptosis of HepG2 cells. Our study provides a novel regulatory mechanism of miR-1 in the apoptosis of hepatoma cells. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Hyperthermia: an effective strategy to induce apoptosis in cancer cells.

PubMed

Ahmed, Kanwal; Tabuchi, Yoshiaki; Kondo, Takashi

2015-11-01

Heat has been used as a medicinal and healing modality throughout human history. The combination of hyperthermia (HT) with radiation and anticancer agents has been used clinically and has shown positive results to a certain extent. However, the clinical results of HT treatment alone have been only partially satisfactory. Cell death following HT treatment is a function of both temperature and treatment duration. HT induces cancer cell death through apoptosis; the degree of apoptosis and the apoptotic pathway vary in different cancer cell types. HT-induced reactive oxygen species production are responsible for apoptosis in various cell types. However, the underlying mechanism of signal transduction and the genes related to this process still need to be elucidated. In this review, we summarize the molecular mechanism of apoptosis induced by HT, enhancement of heat-induced apoptosis, and the genetic network involved in HT-induced apoptosis.

A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells

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

Wei, Ren-Jie

The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G{sub 2}/M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosismore » in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G{sub 2}/M cell cycle regulators, ABT-751 induced G{sub 2}/M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. - Highlights: • An anti-microtubule agent, ABT-751, induces autophagy and apoptosis in Huh-7

VCC-1 over-expression inhibits cisplatin-induced apoptosis in HepG2 cells

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

Zhou, Zhitao; Lu, Xiao; Zhu, Ping

Highlights: Black-Right-Pointing-Pointer VCC-1 is hypothesized to be associated with carcinogenesis. Black-Right-Pointing-Pointer Levels of VCC-1 are increased significantly in HCC. Black-Right-Pointing-Pointer Over-expression of VCC-1 could promotes cellular proliferation rate. Black-Right-Pointing-Pointer Over-expression of VCC-1 inhibit the cisplatin-provoked apoptosis in HepG2 cells. Black-Right-Pointing-Pointer VCC-1 plays an important role in control the tumor growth and apoptosis. -- Abstract: Vascular endothelial growth factor-correlated chemokine 1 (VCC-1), a recently described chemokine, is hypothesized to be associated with carcinogenesis. However, the molecular mechanisms by which aberrant VCC-1 expression determines poor outcomes of cancers are unknown. In this study, we found that VCC-1 was highly expressed in hepatocellularmore » carcinoma (HCC) tissue. It was also associated with proliferation of HepG2 cells, and inhibition of cisplatin-induced apoptosis of HepG2 cells. Conversely, down-regulation of VCC-1 in HepG2 cells increased cisplatin-induced apoptosis of HepG2 cells. In summary, these results suggest that VCC-1 is involved in cisplatin-induced apoptosis of HepG2 cells, and also provides some evidence for VCC-1 as a potential cellular target for chemotherapy.« less

The mitochondria-mediate apoptosis of Lepidopteran cells induced by azadirachtin.

PubMed

Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

2013-01-01

Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis.

The Mitochondria-Mediate Apoptosis of Lepidopteran Cells Induced by Azadirachtin

PubMed Central

Huang, Jingfei; Lv, Chaojun; Hu, Meiying; Zhong, Guohua

2013-01-01

Mitochondria have been shown to play an important role in apoptosis using mammalian cell lines. However, this seems not to be the case in Drosophila, an insect model organism; thus more in-depth studies of insect cell apoptosis are necessary. In the present study, mitochondrial involvement during azadirachtin- and camptothecin-induced apoptosis in Spodoptera frugiperda Sf9 cells (isolated from Spodoptera frugiperda pupal ovarian tissue) was investigated. The results showed that both azadirachtin and camptothecin could induce apoptosis in Sf9 cells. Reactive oxygen species (ROS) generation, activation of mitochondrial permeability transition pores (MPTPs) and loss of mitochondrial membrane potential (MMP) were observed very early during apoptosis and were followed subsequently by the release of cytochrome-c from the mitochondria. Furthermore, the results also revealed that the opening of MPTPs and the loss of MMP induced by azadirachtin could be significantly inhibited by the permeability transition pore (PTP) inhibitor cyclosporin A (CsA), which was used to identify the key role of mitochondria in the apoptosis of Sf9 cells. However, in camptothecin-treated Sf9 cells, CsA could not suppress the opening of MPTPs and the loss of MMP when apoptosis was induced. The data from caspase-3 and caspase-9 activity assays and detection of apoptosis by morphological observation and flow cytometry also uncovered the different effect of CsA on the two botanical apoptosis inducers. Although different mechanisms of apoptosis induction exist, our study revealed that mitochondria play a crucial role in insect cell line apoptosis. PMID:23516491

Intense picosecond pulsed electric fields induce apoptosis through a mitochondrial-mediated pathway in HeLa cells.

PubMed

Hua, Yuan-Yuan; Wang, Xiao-Shu; Zhang, Yu; Yao, Chen-Guo; Zhang, Xi-Ming; Xiong, Zheng-Ai

2012-04-01

The application of pulsed electric fields (PEF) is emerging as a new technique for tumor therapy. Picosecond pulsed electric fields (psPEF) can be transferred to target deep tissue non-invasively and precisely, but the research of the biological effects of psPEF on cells is limited. Electric theory predicts that intense psPEF will target mitochondria and lead to changes in transmembrane potential, therefore, it is hypothesized that it can induce mitochondrial-mediated apoptosis. HeLa cells were exposed to psPEF in this study to investigate this hypothesis. MTT assay demonstrated that intense psPEF significantly inhibited the proliferation of HeLa cells in a dose-dependent manner. Typical characteristics of apoptosis in HeLa cells were observed, using transmission electron microscopy. Loss of mitochondrial transmembrane potential was explored using laser scanning confocal microscopy with Rhodamine-123 (Rh123) staining. Furthermore, the mitochondrial apoptotic events were also confirmed by western blot analysis for the release of cytochrome C and apoptosis-inducing factor from mitochondria into the cytosol. In addition, activation of caspase-3, caspase-9, upregulation of Bax, p53 and downregulation of Bcl-2 were observed in HeLa cells also indicating apoptosis. Taken together, these results demonstrate that intense psPEF induce cell apoptosis through a mitochondrial-mediated pathway.

miR-520 promotes DNA-damage-induced trophoblast cell apoptosis by targeting PARP1 in recurrent spontaneous abortion (RSA).

PubMed

Dong, Xiujuan; Yang, Long; Wang, Hui

2017-04-01

The establishment and maintenance of successful pregnancy mainly depends on trophoblast cells. Their dysfunction has been implicated in recurrent spontaneous abortion (RSA), a major complication of pregnancy. However, the underlying mechanisms of trophoblasts dysfunction remain unclear. DNA-damage-induced cell apoptosis has been reported to play a vital role in cell death. In this study, we identified a novel microRNA (miR-520) in RSA progression via regulating trophoblast cell apoptosis. Microarray analysis showed that miR-520 was highly expressed in villus of RSA patients. By using flow cytometry analysis, we observed miR-520 expression was correlated with human trophoblast cell apoptosis in vitro, along with decreased poly (ADP-ribose) polymerase-1 (PARP1) expression. With the analysis of clinic samples, we observed that miR-520 level was negatively correlated with PARP1 level in RSA villus. In addition, overexpression of PARP1 restored the miR-520-induced trophoblast cell apoptosis in vitro. The status of chromosome in trophoblast implied that miR-520-promoted DNA-damage-induced cell apoptosis to regulate RSA progression. These results indicated that the level of miR-520 might associate with RSA by prompting trophoblast cell apoptosis via PARP1 dependent DNA-damage pathway.

The role of ARK in stress-induced apoptosis in Drosophila cells

PubMed Central

Zimmermann, Katja C.; Ricci, Jean-Ehrland; Droin, Nathalie M.; Green, Douglas R.

2002-01-01

The molecular mechanisms of apoptosis are highly conserved throughout evolution. The homologs of genes essential for apoptosis in Caenorhabditis elegans and Drosophila melanogaster have been shown to be important for apoptosis in mammalian systems. Although a homologue for CED-4/apoptotic protease-activating factor (Apaf)-1 has been described in Drosophila, its exact function and the role of the mitochondrial pathway in its activation remain unclear. Here, we used the technique of RNA interference to dissect apoptotic signaling pathways in Drosophila cells. Inhibition of the Drosophila CED-4/Apaf-1–related killer (ARK) homologue resulted in pronounced inhibition of stress-induced apoptosis, whereas loss of ARK did not protect the cells from Reaper- or Grim-induced cell death. Reduction of DIAP1 induced rapid apoptosis in these cells, whereas the inhibition of DIAP2 expression did not but resulted in increased sensitivity to stress-induced apoptosis; apoptosis in both cases was prevented by inhibition of ARK expression. Cells in which cytochrome c expression was decreased underwent apoptosis induced by stress stimuli, Reaper or Grim. These results demonstrate the central role of ARK in stress-induced apoptosis, which appears to act independently of cytochrome c. Apoptosis induced by Reaper or Grim can proceed via a distinct pathway, independent of ARK. PMID:11901172

Physalin F induces cell apoptosis in human renal carcinoma cells by targeting NF-kappaB and generating reactive oxygen species.

PubMed

Wu, Szu-Ying; Leu, Yann-Lii; Chang, Ya-Ling; Wu, Tian-Shung; Kuo, Ping-Chung; Liao, Yu-Ren; Teng, Che-Ming; Pan, Shiow-Lin

2012-01-01

The aim of this study was to determine the molecular mechanisms of physalin F, an effective purified extract of Physalis angulata L. (Solanacae), in renal carcinoma A498 cells. Physalin F was observed to significantly induce cytotoxicity of three human renal carcinoma A498, ACHN, and UO-31 cells in a concentration-dependent manner; this was especially potent in A498 cells. The physalin F-induced cell apoptosis of A498 cells was characterized by MTT assay, nuclear DNA fragmentation and chromatin condensation. Using flow cytometry analysis, physalin F induced A498 cell apoptosis as demonstrated by the accumulation of the sub-G1 phase in a concentration- and time-dependent manner. Moreover, physalin F-mediated accumulation of reactive oxygen species (ROS) caused Bcl-2 family proteins, Bcl-2, and Bcl-xL degradation, which led to disruption of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-3 and caspase-9 activity, which led to poly(ADP-ribose) polymerase cleavage. However, the antioxidant N-acetyl-(L)-cysteine (NAC) and glutathione (GSH) resulted in the inhibition of these events and reversed physalin F-induced cell apoptosis. In addition, physalin F suppressed NF-κB activity and nuclear translocation of p65 and p50, which was reversed by NAC and GSH. Physalin F induced cell apoptosis through the ROS-mediated mitochondrial pathway and suppressed NF-κB activation in human renal cancer A498 cells. Thus, physalin F appears to be a promising anti-cancer agent worthy of further clinical development.

Physalin F Induces Cell Apoptosis in Human Renal Carcinoma Cells by Targeting NF-kappaB and Generating Reactive Oxygen Species

PubMed Central

Wu, Szu-Ying; Leu, Yann-Lii; Chang, Ya-Ling; Wu, Tian-Shung; Kuo, Ping-Chung; Liao, Yu-Ren; Teng, Che-Ming; Pan, Shiow-Lin

2012-01-01

Background The aim of this study was to determine the molecular mechanisms of physalin F, an effective purified extract of Physalis angulata L. (Solanacae), in renal carcinoma A498 cells. Methodology/Principal Findings Physalin F was observed to significantly induce cytotoxicity of three human renal carcinoma A498, ACHN, and UO-31 cells in a concentration-dependent manner; this was especially potent in A498 cells. The physalin F-induced cell apoptosis of A498 cells was characterized by MTT assay, nuclear DNA fragmentation and chromatin condensation. Using flow cytometry analysis, physalin F induced A498 cell apoptosis as demonstrated by the accumulation of the sub-G1 phase in a concentration- and time-dependent manner. Moreover, physalin F-mediated accumulation of reactive oxygen species (ROS) caused Bcl-2 family proteins, Bcl-2, and Bcl-xL degradation, which led to disruption of mitochondrial membrane potential and release of cytochrome c from the mitochondria into the cytosol. These effects were associated with induction of caspase-3 and caspase-9 activity, which led to poly(ADP-ribose) polymerase cleavage. However, the antioxidant N-acetyl-L-cysteine (NAC) and glutathione (GSH) resulted in the inhibition of these events and reversed physalin F-induced cell apoptosis. In addition, physalin F suppressed NF-κB activity and nuclear translocation of p65 and p50, which was reversed by NAC and GSH. Conclusion Physalin F induced cell apoptosis through the ROS-mediated mitochondrial pathway and suppressed NF-κB activation in human renal cancer A498 cells. Thus, physalin F appears to be a promising anti-cancer agent worthy of further clinical development. PMID:22815798

Sulforaphane‐induced apoptosis in Xuanwei lung adenocarcinoma cell line XWLC‐05

PubMed Central

Zhou, Lan; Yao, Qian; Huang, Yun‐chao; Jiang, Hua; Wang, Chuan‐qiong; Fan, Lei

2016-01-01

Background Xuanwei district in Yunnan Province has the highest incidence of lung cancer in China, especially among non‐smoking women. Cruciferous vegetables can reduce lung cancer risk by prompting a protective mechanism against respiratory tract inflammation caused by air pollution, and are rich in sulforaphane, which can induce changes in gene expression. We investigated the effect of sulforaphane‐induced apoptosis in Xuanwei lung adenocarcinoma cell line (XWCL‐05) to explore the value of sulforaphane in lung cancer prevention and treatment. Methods Cell growth inhibition was determined by methyl thiazolyl tetrazolium assay; cell morphology and apoptosis were observed under transmission electron microscope; cell cycle and apoptosis rates were detected using flow cytometry; B‐cell lymphoma 2 (Bcl‐2) and Bcl‐2‐like protein 4 (Bax) messenger RNA expression were determined by quantitative PCR; and p53, p73, p53 upregulated modulator of apoptosis (PUMA), Bax, Bcl‐2, and caspase‐9 protein expression were detected by Western blotting. Results Sulforaphane inhibited XWLC‐05 cell growth with inhibitory concentration (IC)50 of 4.04, 3.38, and 3.02 μg/mL at 24, 48, and 72 hours, respectively. Sulforaphane affected the XWLC‐05 cell cycle as cells accumulated in the G2/M phase. The proportion of apoptotic cells observed was 27.6%. Compared with the control, the sulforaphane group showed decreased Bcl‐2 and p53 expression, and significantly increased p73, PUMA, Bax, and caspase‐9 protein expression (P < 0.05). Conclusion Sulforaphane induces Xuanwei lung adenocarcinoma cell apoptosis. Its possible mechanism may involve the upregulation of p73 expression and its effector target genes PUMA and Bax in lung cancer cells, downregulation of the anti‐apoptotic gene B cl ‐2, and activation of caspase‐9. It may also involve downregulation of the mutant p53 protein. PMID:27878984

Novel microtubule-targeted agent 6-chloro-4-(methoxyphenyl) coumarin induces G2-M arrest and apoptosis in HeLa cells

PubMed Central

Ma, Yi-ming; Zhou, Yu-bo; Xie, Chuan-ming; Chen, Dong-mei; Li, Jia

2012-01-01

Aim: To identify a novel coumarin analogue with the highest anticancer activity and to further investigate its anticancer mechanisms. Methods: The viability of cancer cells was investigated using the MTT assay. The cell cycle progression was evaluated using both flow cytometric and Western blotting analysis. Microtubule depolymerization was observed with immunocytochemistry in vivo and a tubulin depolymerization assay in vitro. Apoptosis was demonstrated using Annexin V/Propidium Iodide (PI) double-staining and sub-G1 analysis. Results: Among 36 analogues of coumarin, 6-chloro-4-(methoxyphenyl) coumarin showed the best anticancer activity (IC50 value about 200 nmol/L) in HCT116 cells. The compound had a broad spectrum of anticancer activity against 9 cancer cell lines derived from colon cancer, breast cancer, liver cancer, cervical cancer, leukemia, epidermoid cancer with IC50 value of 75 nmol/L–1.57 μmol/L but with low cytotocitity against WI-38 human lung fibroblasts (IC50 value of 12.128 μmol/L). The compound (0.04–10 μmol/L) induced G2-M phase arrest in HeLa cells in a dose-dependent manner, which was reversible after the compound was removed. The compound (10–300 μmol/L) induced the depolymerization of purified porcine tubulin in vitro. Finally, the compound (0.04–2.5 μmol/L) induced apoptosis of HeLa cells in dose- and time-dependent manners. Conclusion: 6-Chloro-4-(methoxyphenyl) coumarin is a novel microtubule-targeting agent that induces G2–M arrest and apoptosis in HeLa cells. PMID:22266726

GSK-3β mediates dexamethasone-induced pancreatic β cell apoptosis

PubMed Central

Guo, Bin; Zhang, Wenjian; Xu, Shiqing; Lou, Jinning; Wang, Shuxia; Men, Xiuli

2015-01-01

Aims Glucocorticoids, such as dexamethasone, are widely used anti-inflammatory drugs. Their use is frequently associated with the development of steroid- associated diabetes. Pancreatic β-cell dysfunction has been suggested to be one of the main causes of steroid-associated diabetes. However, the mechanism is not fully understood. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase and plays an important role in energy metabolism, cell growth and apoptosis. Therefore, the contribution of GSK-3β in dexamethasone-induced pancreatic β-cell apoptosis was determined in the present study. Main Methods The effect of dexamethasone treatment on rat pancreatic β-cell line (INS-1) apoptosis (determined by TUNEL and Flow Cytometry), generation of reactive oxidative stress (ROS), and the phosphorylation status of GSK-3β was determined. The inhibitory effect of GSK-3β inhibitor-lithium chloride (LiCl) on dexamethasone-induced β-cell apoptosis was also evaluated. Key Findings Dexamethasone (0.1 μM) treatment induced INS-1 apoptosis, which was associated with increased GSK-3β activation and increased NOX4-derived ROS generation. Pretreatment of INS-1 with LiCl inhibited dexamethasone induced ROS generation and INS-1 apoptosis. Significance This study provides a new mechanism of Dex induced pancreatic β cell apoptosis and may serve as a new therapeutic option for treating GCs induced diabetes. PMID:26606859

Low intensity ultrasound induces apoptosis via MPT channel on mitochondrial membrane: Target for regulating cancer therapy or not?

NASA Astrophysics Data System (ADS)

Feng, Yi; Wan, Mingxi

2017-03-01

To discuss how the mitochondrion is involved in low intensity ultrasound induced apoptosis, HepG2 cells were irradiated by low intensity focused ultrasound (ISPTA = 3W/cm2, 1 min) and then cultured from 3-12 h post irradiation in the study. The morphological alteration was examined by light and fluorescent microscopy respectively. Cell viability and apoptosis were examined by trypan blue staining and flow cytometry with double staining of FITC-labelled Annexin-V/PI. Key proteins responded to irradiation were screened out by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and shotgun proteomic methods with Agilent 1100 HPLC-Chip-MS technology. Representative apoptotic morphological characteristics and increased percentage of apoptotic cells were achieved. Six important proteins (4 up-regulated and 2 down-regulated) were selected and analyzed. It revealed low intensity focused ultrasound could induce apoptosis in HepG2 cells and the US-induced apoptosis was mitochondria-dependent and caspases-dependent. Moreover, mitochondrial membrane permeability transition (MPT) is related to ultrasound induced apoptosis, but VDAC may be not the main MPT channel. Understanding it could help to assist the cancer therapy by regulating the MPT as the target.

Targeting the GD3 acetylation pathway selectively induces apoptosis in glioblastoma

PubMed Central

Birks, Suzanne M.; Danquah, John Owusu; King, Linda; Vlasak, Reinhardt; Gorecki, Dariusz C.; Pilkington, Geoffrey J.

2011-01-01

The expression of ganglioside GD3, which plays crucial roles in normal brain development, decreases in adults but is upregulated in neoplastic cells, where it regulates tumor invasion and survival. Normally a buildup of GD3 induces apoptosis, but this does not occur in gliomas due to formation of 9-O-acetyl GD3 by the addition of an acetyl group to the terminal sialic acid of GD3; this renders GD3 unable to induce apoptosis. Using human biopsy-derived glioblastoma cell cultures, we have carried out a series of molecular manipulations targeting GD3 acetylation pathways. Using immunocytochemistry, flow cytometry, western blotting, and transwell assays, we have shown the existence of a critical ratio between GD3 and 9-O-acetyl GD3, which promotes tumor survival. Thus, we have demonstrated for the first time in primary glioblastoma that cleaving the acetyl group restores GD3, resulting in a reduction in tumor cell viability while normal astrocytes remain unaffected. Additionally, we have shown that glioblastoma viability is reduced due to the induction of mitochondrially mediated apoptosis and that this occurs after mitochondrial membrane depolarization. Three methods of cleaving the acetyl group using hemagglutinin esterase were investigated, and we have shown that the baculovirus vector transduces glioma cells as well as normal astroctyes with a relatively high efficacy. A recombinant baculovirus containing hemagglutinin esterase could be developed for the clinic as an adjuvant therapy for glioma. PMID:21807667

Nonylphenol diethoxylate inhibits apoptosis induced in PC12 cells.

PubMed

Liu, Chuang; Sun, Yongkun; Song, Yutong; Saito, Takeshi; Kurasaki, Masaaki

2016-11-01

Nonylphenol and short-chain nonylphenol ethoxylates such as NP 2 EO are present in aquatic environment as wastewater contaminants, and their toxic effects on aquatic species have been reported. Apoptosis has been shown to be induced by serum deprivation or copper treatment. To understand the toxicity of nonylphenol diethoxylate, we investigated the effects of NP 2 EO on apoptosis induced by serum deprivation and copper by using PC12 cell system. Nonylphenol diethoxylate itself showed no toxicity and recovered cell viability from apoptosis. In addition, nonylphenol diethoxylate decreased DNA fragmentation caused by apoptosis in PC12 cells. This phenomenon was confirmed after treating apoptotic PC12 cells with nonylphenol diethoxylate, whereas the cytochrome c release into the cytosol decreased as compared to that in apoptotic cells not treated with nonylphenol diethoxylates. Furthermore, Bax contents in apoptotic cells were reduced after exposure to nonylphenol diethoxylate. Thus, nonylphenol diethoxylate has the opposite effect on apoptosis in PC12 cells compared to nonylphenol, which enhances apoptosis induced by serum deprivation. The difference in structure of the two compounds is hypothesized to be responsible for this phenomenon. These results indicated that nonylphenol diethoxylate has capability to affect cell differentiation and development and has potentially harmful effect on organisms because of its unexpected impact on apoptosis. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1389-1398, 2016. © 2015 Wiley Periodicals, Inc.

Inducing death in tumor cells: roles of the inhibitor of apoptosis proteins.

PubMed

Finlay, Darren; Teriete, Peter; Vamos, Mitchell; Cosford, Nicholas D P; Vuori, Kristiina

2017-01-01

The heterogeneous group of diseases collectively termed cancer results not just from aberrant cellular proliferation but also from a lack of accompanying homeostatic cell death. Indeed, cancer cells regularly acquire resistance to programmed cell death, or apoptosis, which not only supports cancer progression but also leads to resistance to therapeutic agents. Thus, various approaches have been undertaken in order to induce apoptosis in tumor cells for therapeutic purposes. Here, we will focus our discussion on agents that directly affect the apoptotic machinery itself rather than on drugs that induce apoptosis in tumor cells indirectly, such as by DNA damage or kinase dependency inhibition. As the roles of the Bcl-2 family have been extensively studied and reviewed recently, we will focus in this review specifically on the inhibitor of apoptosis protein (IAP) family. IAPs are a disparate group of proteins that all contain a baculovirus IAP repeat domain, which is important for the inhibition of apoptosis in some, but not all, family members. We describe each of the family members with respect to their structural and functional similarities and differences and their respective roles in cancer. Finally, we also review the current state of IAPs as targets for anti-cancer therapeutics and discuss the current clinical state of IAP antagonists.

Chalcones Enhance TRAIL-Induced Apoptosis in Prostate Cancer Cells

PubMed Central

Szliszka, Ewelina; Czuba, Zenon P; Mazur, Bogdan; Sedek, Lukasz; Paradysz, Andrzej; Krol, Wojciech

2009-01-01

Chalcones exhibit chemopreventive and antitumor effects. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a naturally occurring anticancer agent that induces apoptosis in cancer cells and is not toxic to normal cells. We examined the cytotoxic and apoptotic effect of five chalcones in combination with TRAIL on prostate cancer cells. The cytotoxicity was evaluated by the MTT and LDH assays. The apoptosis was determined using flow cytometry with annexin V-FITC. Our study showed that all five tested chalcones: chalcone, licochalcone-A, isobavachalcone, xanthohumol, butein markedly augmented TRAIL-mediated apoptosis and cytotoxicity in prostate cancer cells and confirmed the significant role of chalcones in chemoprevention of prostate cancer. PMID:20161998

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.

3,3'-diindolylmethane potentiates tumor necrosis factor-related apoptosis-inducing ligand-induced apoptosis of gastric cancer cells.

PubMed

Ye, Yang; Miao, Shuhan; Wang, Yan; Zhou, Jianwei; Lu, Rongzhu

2015-05-01

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) specifically kills cancer cells without destroying the majority of healthy cells. However, numerous types of cancer cell, including gastric cancer cells, tend to be resistant to TRAIL. The bioactive product 3,3'-diindolylmethane (DIM), which is derived from cruciferous vegetables, is also currently recognized as a candidate anticancer agent. In the present study, a Cell Counting Kit 8 cell growth assay and an Annexin V-fluorescein isothiocyanate apoptosis assay were performed to investigate the potentiating effect of DIM on TRAIL-induced apoptosis in gastric cancer cells, and the possible mechanisms of this potentiation. The results obtained demonstrated that, compared with TRAIL or DIM treatment alone, co-treatment with TRAIL (25 or 50 ng/ml) and DIM (10 µmol/l) induced cytotoxic and apoptotic effects in BGC-823 and SGC-7901 gastric cancer cells. Furthermore, western blot analysis revealed that the protein expression levels of death receptor 5 (DR5), CCAAT/enhancer binding protein homologous protein (CHOP) and glucose-regulated protein 78 (GRP78) were upregulated in the co-treated gastric cancer cells. To the best of our knowledge, the present study is the first to provide evidence that DIM sensitizes TRAIL-induced inhibition of proliferation and apoptosis in gastric cancer cells, accompanied by the upregulated expression of DR5, CHOP and GRP78 proteins, which may be involved in endoplasmic reticulum stress mechanisms.

Mangiferin induces apoptosis in human ovarian adenocarcinoma OVCAR3 cells via the regulation of Notch3

PubMed Central

Zou, Bingyu; Wang, Hailian; Liu, Yilong; Qi, Ping; Lei, Tiantian; Sun, Minghan; Wang, Yi

2017-01-01

Ovarian cancer is the most lethal gynecological malignancy in the world. Our previous studies showed that mangiferin, purified from plant source, possessed anti-neoplasm effect on human lung adenocarcinoma A549 cells. This study aimed to determine the apoptosis-inducing effect of mangiferin on human ovarian carcinoma OVCAR3 cells. By in vitro studies, we found mangiferin significantly inhibited viability of OVCAR3 cells, and remarkably increased the sensitivity of OVCAR3 cells to cisplatin. In addition, the activation of caspase-dependent apoptosis was observed in mangiferin treated ovarian cancer cells. Importantly, we observed an obviously downregulated Notch expression after mangiferin treatment, indicating the crucial role of Notch in mangiferin mediated apoptosis. In contrast, overexpression of Notch3 abrogated the apoptosis-inducing efficacy of mangiferin, further demonstrating that mangiferin induced apoptosis via Notch pathway. Furthermore, OVCAR3 cell xenograft models revealed that mangiferin treatment inhibited tumor growth and expanded survival of tumor xenograft mice. Based on these results, we concluded that mangiferin could significantly inhibit the proliferation and induce apoptosis in OVCAR3 cells. Our study also suggested the anti-neoplasm effect of mangiferin might be via the regulation of Notch3. Taken together, by targeting cell apoptosis pathways and enhancing the response to cisplatin treatment, mangiferin may represent a potential new drug for the treatment of human ovarian cancer. PMID:28714011

Mangiferin induces apoptosis in human ovarian adenocarcinoma OVCAR3 cells via the regulation of Notch3.

PubMed

Zou, Bingyu; Wang, Hailian; Liu, Yilong; Qi, Ping; Lei, Tiantian; Sun, Minghan; Wang, Yi

2017-09-01

Ovarian cancer is the most lethal gynecological malignancy in the world. Our previous studies showed that mangiferin, purified from plant source, possessed anti-neoplasm effect on human lung adenocarcinoma A549 cells. This study aimed to determine the apoptosis-inducing effect of mangiferin on human ovarian carcinoma OVCAR3 cells. By in vitro studies, we found mangiferin significantly inhibited viability of OVCAR3 cells, and remarkably increased the sensitivity of OVCAR3 cells to cisplatin. In addition, the activation of caspase-dependent apoptosis was observed in mangiferin treated ovarian cancer cells. Importantly, we observed an obviously downregulated Notch expression after mangiferin treatment, indicating the crucial role of Notch in mangiferin mediated apoptosis. In contrast, overexpression of Notch3 abrogated the apoptosis-inducing efficacy of mangiferin, further demonstrating that mangiferin induced apoptosis via Notch pathway. Furthermore, OVCAR3 cell xenograft models revealed that mangiferin treatment inhibited tumor growth and expanded survival of tumor xenograft mice. Based on these results, we concluded that mangiferin could significantly inhibit the proliferation and induce apoptosis in OVCAR3 cells. Our study also suggested the anti-neoplasm effect of mangiferin might be via the regulation of Notch3. Taken together, by targeting cell apoptosis pathways and enhancing the response to cisplatin treatment, mangiferin may represent a potential new drug for the treatment of human ovarian cancer.

Single-cell-precision microplasma-induced cancer cell apoptosis.

PubMed

Tan, Xiao; Zhao, Shasha; Lei, Qian; Lu, Xinpei; He, Guangyuan; Ostrikov, Kostya

2014-01-01

The issue of single-cell control has recently attracted enormous interest. However, in spite of the presently achievable intracellular-level physiological probing through bio-photonics, nano-probe-based, and some other techniques, the issue of inducing selective, single-cell-precision apoptosis, without affecting neighbouring cells remains essentially open. Here we resolve this issue and report on the effective single-cell-precision cancer cell treatment using the reactive chemistry of the localized corona-type plasma discharge around a needle-like electrode with the spot size ∼1 µm. When the electrode is positioned with the micrometer precision against a selected cell, a focused and highly-localized micro-plasma discharge induces apoptosis in the selected individual HepG2 and HeLa cancer cells only, without affecting any surrounding cells, even in small cell clusters. This is confirmed by the real-time monitoring of the morphological and structural changes at the cellular and cell nucleus levels after the plasma exposure.

Geraniol induces cooperative interaction of apoptosis and autophagy to elicit cell death in PC-3 prostate cancer cells.

PubMed

Kim, Su-Hwa; Park, Eun-Jung; Lee, Chae Ryun; Chun, Jung Nyeo; Cho, Nam-Hyuk; Kim, In-Gyu; Lee, Sanghoon; Kim, Tae Woo; Park, Hyun Ho; So, Insuk; Jeon, Ju-Hong

2012-05-01

Geraniol, an acyclic dietary monoterpene, suppresses prostate cancer growth and enhances docetaxel chemosensitivity in cultured cell or xenograft tumor models. However, the mechanisms of the geraniol action against prostate cancer are largely unknown. In this study, we investigated the cellular and molecular mechanisms of geraniol-induced cell death in PC-3 prostate cancer cells. Among the examined structurally and functionally similar monoterpenes, geraniol potently induced apoptosis and autophagy. Although independent processes, apoptosis and autophagy acted as cooperative partners to elicit geraniol-induced cell death in PC-3 cells. At a molecular level, geraniol inhibited AKT signaling and activated AMPK signaling, resulting in mTOR inhibition. Combined treatment of AKT inhibitor and AMPK activator markedly suppressed cell growth compared to either treatment alone. Our findings provide insight into future investigations that are aimed at elucidating the role of apoptosis and autophagy in prostate cancer therapy and at developing anticancer strategies co-targeting AKT and AMPK.

Hypoxia promotes apoptosis of neuronal cells through hypoxia-inducible factor-1α-microRNA-204-B-cell lymphoma-2 pathway

PubMed Central

Wang, Xiuwen; Li, Ji; Wu, Dongjin; Bu, Xiangpeng

2015-01-01

Neuronal cells are highly sensitive to hypoxia and may be subjected to apoptosis when exposed to hypoxia. Several apoptosis-related genes and miRNAs involve in hypoxia-induced apoptosis. This study aimed to examine the role of HIF1α-miR-204-BCL-2 pathway in hypoxia-induced apoptosis in neuronal cells. Annexin V/propidium iodide assay was performed to analyze cell apoptosis in AGE1.HN and PC12 cells under hypoxic or normoxic conditions. The expression of BCL-2 and miR-204 were determined by Western blot and qRT-PCR. The effects of miR-204 overexpression or knockdown on the expression of BCL-2 were evaluated by luciferase assay and Western blot under hypoxic or normoxic conditions. HIF-1α inhibitor YC-1 and siHIF-1α were employed to determine the effect of HIF-1α on the up-regulation of miR-204 and down-regulation of BCL-2 induced by hypoxia. Apoptosis assay showed the presence of apoptosis induced by hypoxia in neuronal cells. Moreover, we found that hypoxia significantly down-regulated the expression of BCL-2, and increased the mRNA level of miR-204 in neuronal cells than that in control. Bioinformatic analysis and luciferase reporter assay demonstrated that miR-204 directly targeted and regulated the expression of BCL-2. Specifically, the expression of BCL-2 was inhibited by miR-204 mimic and enhanced by miR-204 inhibitor. Furthermore, we detected that hypoxia induced cell apoptosis via HIF-1α/miR-204/BCL-2 in neuronal cells. This study demonstrated that HIF-1α-miR-204-BCL-2 pathway contributed to apoptosis of neuronal cells induced by hypoxia, which could potentially be exploited to prevent spinal cord ischemia–reperfusion injury. PMID:26350953

N-acetylcysteine protects against cadmium-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in testes.

PubMed

Ji, Yan-Li; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Xu, De-Xiang

2013-03-01

Cadmium (Cd) is a reproductive toxicant that induces germ cell apoptosis in the testes. Previous studies have demonstrated that endoplasmic reticulum (ER) stress is involved in Cd-induced germ cell apoptosis. The aim of the present study was to investigate the effects of N-acetylcysteine (NAC), an antioxidant, on Cd-induced ER stress and germ cell apoptosis in the testes. Male CD-1 mice were intraperitoneally injected with CdCl2 (2.0 mg kg(-1)). As expected, acute Cd exposure induced germ cell apoptosis in the testes, as determined by terminal dUTP nick-end labelling (TUNEL). However, the administration of NAC alleviated Cd-induced germ cell apoptosis in the testes. Further analysis showed that NAC attenuated the Cd-induced upregulation of testicular glucose-regulated protein 78 (GRP78), an important ER molecular chaperone. Moreover, NAC inhibited the Cd-induced phosphorylation of testicular eukaryotic translation initiation factor 2α (eIF2α), a downstream target of the double-stranded RNA-activated kinase-like ER kinase (PERK) pathway. In addition, NAC blocked the Cd-induced activation of testicular X binding protein (XBP)-1, indicating that NAC attenuates the Cd-induced ER stress and the unfolded protein response (UPR). Interestingly, NAC almost completely prevented the Cd-induced elevation of C/EBP homologous protein (CHOP) and phosphorylation of c-Jun N-terminal kinase (JNK), two components of the ER stress-mediated apoptotic pathway. In conclusion, NAC protects against Cd-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in the testes.

N-acetylcysteine protects against cadmium-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in testes

PubMed Central

Ji, Yan-Li; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Xu, De-Xiang

2013-01-01

Cadmium (Cd) is a reproductive toxicant that induces germ cell apoptosis in the testes. Previous studies have demonstrated that endoplasmic reticulum (ER) stress is involved in Cd-induced germ cell apoptosis. The aim of the present study was to investigate the effects of N-acetylcysteine (NAC), an antioxidant, on Cd-induced ER stress and germ cell apoptosis in the testes. Male CD-1 mice were intraperitoneally injected with CdCl2 (2.0 mg kg−1). As expected, acute Cd exposure induced germ cell apoptosis in the testes, as determined by terminal dUTP nick-end labelling (TUNEL). However, the administration of NAC alleviated Cd-induced germ cell apoptosis in the testes. Further analysis showed that NAC attenuated the Cd-induced upregulation of testicular glucose-regulated protein 78 (GRP78), an important ER molecular chaperone. Moreover, NAC inhibited the Cd-induced phosphorylation of testicular eukaryotic translation initiation factor 2α (eIF2α), a downstream target of the double-stranded RNA-activated kinase-like ER kinase (PERK) pathway. In addition, NAC blocked the Cd-induced activation of testicular X binding protein (XBP)-1, indicating that NAC attenuates the Cd-induced ER stress and the unfolded protein response (UPR). Interestingly, NAC almost completely prevented the Cd-induced elevation of C/EBP homologous protein (CHOP) and phosphorylation of c-Jun N-terminal kinase (JNK), two components of the ER stress-mediated apoptotic pathway. In conclusion, NAC protects against Cd-induced germ cell apoptosis by inhibiting endoplasmic reticulum stress in the testes. PMID:23353715

Exploring a Novel Target Treatment on Breast Cancer: Aloe-emodin Mediated Photodynamic Therapy Induced Cell Apoptosis and Inhibited Cell Metastasis.

PubMed

Chen, Qing; Tian, Si; Zhu, Jing; Li, Kai-Ting; Yu, Ting-He; Yu, Le-Hua; Bai, Ding-Qun

2016-01-01

Photodynamic therapy (PDT) as a clinical cancer therapy, is a mild therapy, which involves application of photosensitizers (PSs) located in target cells and then irradiated by corresponding wavelength. The activation of PSs generates radical oxygen species (ROS) to exert a selective cytotoxic activity for the target cells. Aloe-emodin (AE) has been found to be an anti-tumor agent in many studies, and has also been demonstrated as a photosensitizer, in the recent years. In order to study the mechanisms of aloe-emodin as a photosensitizer, we investigated the mechanisms of photo-cytotoxicity induced by aloe-emodin in breast cancer MCF-7 cells in the present study. Analysis of cell proliferation evidenced that there was a drastic depression after photodynamic treatment with a series of aloe-emodin concentrations and light doses. We observed changes in apoptosis and demonstrated that the mechanisms of apoptosis were involved in mitochondrial and endoplasmic reticulum death pathways. The capacity of adhesion, migration and invasion of breast cells was measured using WST8 and transwell assay and demonstrated that AE-PDT significantly inhibited adhesion, migration and invasion of MCF-7cells. The expression of MMP2, MMP9, VEGF and Nrf2 demonstrated that the metastasis was related to oxidative stress. Analysis of changes in cytoskeleton components (F-actin) evidenced cytoskeleton disorganization after treatment with AE-PDT. Taken together, the present results indicated that PDT with aloe-emodin effectively suppressed cancer development in MCF-7cells, suggesting the potential of AE as a new photosensitizer in PDT which can provide a new modility for treating cancer.

[Progress on mechanism of cell apoptosis induced by rubella virus].

PubMed

Li, Zhen-mei; Chu, Fu-lu; Liu, Ying; Wang, Zhi-yu

2013-09-01

Rubella virus (RV), a member of the family Togaviridae, can induce apoptosis of host cells in vitro. Protein kinases of the Ras-Raf-MEK-ERK pathway and PI3K-Akt pathway play essential roles in virus multiplication, cell survival and apoptosis. Proteins p53 and TAp63 that bind to specific DNA sequences stimulate Bax in a manner to produce functional pores that facilitate release of mitochondrial cytochrome c and downstream caspase activation. In this review, the molecular mechanisms of RV-induced cell apoptosis, including RV-infected cell lines, pathological changes in cell components and apoptosis signaling pathways are summarized.

Peroxisome proliferators induce apoptosis in hepatoma cells.

PubMed

Canuto, R A; Muzio, G; Bonelli, G; Maggiora, M; Autelli, R; Barbiero, G; Costelli, P; Brossa, O; Baccino, F M

1998-01-01

In the AH-130 hepatoma, a poorly differentiated tumor, maintained by weekly transplantations in rats, a low percentage of cells spontaneously underwent apoptosis, mainly during the transition from logarithmic- to stationary-growth phase. It was possible to induce massive apoptosis of cells by treating them with clofibrate, a peroxisome proliferator and hypolipidemic drug. Similar results were obtained with HepG2 cells. With 1 mM clofibrate, apoptosis began to manifest itself after 1 h of treatment in vitro, and was assessed by morphological analysis, by DNA fragmentation carried out with agarose gel electrophoresis, and with flow cytometric determination of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling. The mechanisms whereby clofibrate induces apoptosis are still unclear. Since the peroxisome proliferator-activated receptor was expressed at a very low level and was not stimulated by clofibrate in the AH-130 hepatoma cells, its involvement seems unlikely. Moreover, lipid peroxidation was not increased after clofibrate treatment. Phospholipids and cholesterol were significantly decreased. The decreased cholesterol content might suggest an inhibition of the mevalonate pathway and, therefore, of isoprenylation of proteins involved in cell proliferation.

Human CD3+ T-Cells with the Anti-ERBB2 Chimeric Antigen Receptor Exhibit Efficient Targeting and Induce Apoptosis in ERBB2 Overexpressing Breast Cancer Cells

PubMed Central

Munisvaradass, Rusheni; Kumar, Suresh; Govindasamy, Chandramohan; Alnumair, Khalid S.; Mok, Pooi Ling

2017-01-01

Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non–transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours. PMID:28885562

Human CD3+ T-Cells with the Anti-ERBB2 Chimeric Antigen Receptor Exhibit Efficient Targeting and Induce Apoptosis in ERBB2 Overexpressing Breast Cancer Cells.

PubMed

Munisvaradass, Rusheni; Kumar, Suresh; Govindasamy, Chandramohan; Alnumair, Khalid S; Mok, Pooi Ling

2017-09-08

Breast cancer is a common malignancy among women. The innate and adaptive immune responses failed to be activated owing to immune modulation in the tumour microenvironment. Decades of scientific study links the overexpression of human epidermal growth factor receptor 2 (ERBB2) antigen with aggressive tumours. The Chimeric Antigen Receptor (CAR) coding for specific tumour-associated antigens could initiate intrinsic T-cell signalling, inducing T-cell activation, and cytotoxic activity without the need for major histocompatibility complex recognition. This renders CAR as a potentially universal immunotherapeutic option. Herein, we aimed to establish CAR in CD3+ T-cells, isolated from human peripheral blood mononucleated cells that could subsequently target and induce apoptosis in the ERBB2 overexpressing human breast cancer cell line, SKBR3. Constructed CAR was inserted into a lentiviral plasmid containing a green fluorescent protein tag and produced as lentiviral particles that were used to transduce activated T-cells. Transduced CAR-T cells were then primed with SKBR3 cells to evaluate their functionality. Results showed increased apoptosis in SKBR3 cells co-cultured with CAR-T cells compared to the control (non-transduced T-cells). This study demonstrates that CAR introduction helps overcome the innate limitations of native T-cells leading to cancer cell apoptosis. We recommend future studies should focus on in vivo cytotoxicity of CAR-T cells against ERBB2 expressing tumours.

p8 attenuates the apoptosis induced by dihydroartemisinin in cancer cells through promoting autophagy

PubMed Central

Chen, Sang-Sang; Hu, Wei; Wang, Zeng; Lou, Xiao-E; Zhou, Hui-Jun

2015-01-01

Dihydroartemisinin (DHA) exhibits anticancer activities in a variety of cancer cells, but DHA alone are not effective enough for cancer therapy. In this study we found the stress-regulated protein p8 was obviously increased after DHA treatment in several cancer cells, which further to induce autophagy by the upregulation of endoplasmic reticulum stress-related protein ATF4 and CHOP. Furthermore, when we silenced p8 by siRNA in cancer cells, the apoptosis induced by DHA were notably increased, whereas the overexpression of p8 in cancer cells leaded to the resistance to DHA-induced apoptosis. Moreover, we found the inhibition of autophagy with chloroquine (CQ) can enhance the anticancer effect of DHA both in vitro and in vivo. In conclusion, we found that p8-mediated autophagy attenuates DHA-induced apoptosis in cancer cells, which provides evidence to support the use p8 as a cancer therapeutic target, and suggests that the combination treatment with DHA and autophagy inhibitor might be an effective cancer therapeutic strategy. PMID:25891535

Fisetin induces apoptosis through mitochondrial apoptosis pathway in human uveal melanoma cells.

PubMed

Wang, Kai; Hu, Dan-Ning; Lin, Hui-Wen; Yang, Wei-En; Hsieh, Yi-Hsien; Chien, Hsiang-Wen; Yang, Shun-Fa

2018-05-01

Fisetin, a diatery flavonoid, been reported that possess anticancer effects in various cancers. The purpose of the study was to investigate the antitumor effects of fisetin in cultured uveal melanoma cell lines and compared with normal retinal pigment epithelial (RPE) cells. MTT assay was used for evaluating cytotoxic effects of fisetin. Flow cytometry study was used for the determination of apoptosis. JC-1 fluorescent reader was used to determine mitochondrial transmembrane potential changes. The results shown that fisetin dose-dependently decreased the cell viability of uveal melanoma cells but not influenced the cell viability of RPE cells. Apoptosis of uveal melanoma cells was induced by fisetin efficiently. Fisetin inhibited antiapoptotic Bcl-2 family proteins and damaged the mitochondrial transmembrane potential. The levels of proapoptotic Bcl-2 proteins, cytochrome c, and various caspase activities were increased by fisetin. In conclusion, fisetin induces apoptosis of uveal melanoma cells selectively and may be a promising agent to be explored for the treatment of uveal melanoma. © 2018 Wiley Periodicals, Inc.

[The mechanism of docetaxel-induced apoptosis in human lung cancer cells].

PubMed

Li, Y; Shi, T; Zhao, W

2000-05-01

To study the mechanism of docetaxel-induced apoptosis. Morphological study, DNA gel electrophoresis, flow cytometry and fluorescin labeled Annexin V to detect apoptosis, RT-PCR to detect the gene related with apoptosis. Human lung cancer A549 cells treated with docetaxel induced cell cycle arrest at G2M phase, leading to apoptosis. The morphology of A549 showed nuclear chromatine condensation and fragmentation. Typical ladder pattern of DNA fragmentation was observed. Sub-G1 peak was found by flow cytometry. Transcription of Fas gene was enhanced, while no change in c-myc and bcl-2 genes. Annexin labeling results revealed the co-existence of cell apoptosis and necrosis in docetaxel-treated A549 cells. Docetaxel induces apoptosis and necrosis of human lung cancer. The induction of apoptosis may be related to expression of Fas.

Novel TRAIL sensitizer Taraxacum officinale F.H. Wigg enhances TRAIL-induced apoptosis in Huh7 cells.

PubMed

Yoon, Ji-Yong; Cho, Hyun-Soo; Lee, Jeong-Ju; Lee, Hyo-Jung; Jun, Soo Young; Lee, Jae-Hye; Song, Hyuk-Hwan; Choi, SangHo; Saloura, Vassiliki; Park, Choon Gil; Kim, Cheol-Hee; Kim, Nam-Soon

2016-04-01

TRAIL (TNF-related apoptosis inducing ligand) is a promising anti-cancer drug target that selectively induces apoptosis in cancer cells. However, many cancer cells are resistant to TRAIL-induced apoptosis. Therefore, reversing TRAIL resistance is an important step for the development of effective TRAIL-based anti-cancer therapies. We previously reported that knockdown of the TOR signaling pathway regulator-like (TIPRL) protein caused TRAIL-induced apoptosis by activation of the MKK7-c-Jun N-terminal Kinase (JNK) pathway through disruption of the MKK7-TIPRL interaction. Here, we identified Taraxacum officinale F.H. Wigg (TO) as a novel TRAIL sensitizer from a set of 500 natural products using an ELISA system and validated its activity by GST pull-down analysis. Furthermore, combination treatment of Huh7 cells with TRAIL and TO resulted in TRAIL-induced apoptosis mediated through inhibition of the MKK7-TIPRL interaction and subsequent activation of MKK7-JNK phosphorylation. Interestingly, HPLC analysis identified chicoric acid as a major component of the TO extract, and combination treatment with chicoric acid and TRAIL induced TRAIL-induced cell apoptosis via JNK activation due to inhibition of the MKK7-TIPRL interaction. Our results suggest that TO plays an important role in TRAIL-induced apoptosis, and further functional studies are warranted to confirm the importance of TO as a novel TRAIL sensitizer for cancer therapy. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Bupivacaine induces apoptosis via ROS in the Schwann cell line.

PubMed

Park, C J; Park, S A; Yoon, T G; Lee, S J; Yum, K W; Kim, H J

2005-09-01

Local anesthetics have been generally accepted as being safe. However, recent clinical trials and basic studies have provided strong evidence for the neurotoxicity of local anesthetics, especially through apoptosis. We hypothesized that local anesthetics cause neural complications through Schwann cell apoptosis. Among local anesthetics tested on the Schwann cell line, RT4-D6P2T, bupivacaine significantly induced cell death, measured by the methyl tetrazolium (MTT) assay, in a dose- (LD50 = 476 microM) and time-dependent manner. The bupivacaine-induced generation of reactive oxygen species (ROS), which was initiated within 5 hrs and preceded the activation of caspase-3 and poly ADP-ribose polymerase (PARP) degradation, was suggested to trigger apoptosis, exhibited by Hoechst 33258 nuclear staining and DNA fragmentation. Furthermore, concomitant block of ROS by anti-oxidants significantly inhibited bupivacaine-induced apoptosis. Among the local anesthetics for peripheral neural blocks, bupivacaine induced apoptosis in the Schwann cell line, which may be associated with ROS production.

Sophoraflavanone G induces apoptosis of human cancer cells by targeting upstream signals of STATs.

PubMed

Kim, Byung-Hak; Won, Cheolhee; Lee, Yun-Han; Choi, Jung Sook; Noh, Kum Hee; Han, Songhee; Lee, Haeri; Lee, Chang Seok; Lee, Dong-Sup; Ye, Sang-Kyu; Kim, Myoung-Hwan

2013-10-01

Aberrantly activated signal transducer and activator of transcription (STAT) proteins are implicated with human cancers and represent essential roles for cancer cell survival and proliferation. Therefore, the development of small-molecule inhibitors of STAT signaling bearing pharmacological activity has therapeutic potential for the treatment of human cancers. In this study, we identified sophoraflavanone G as a novel small-molecule inhibitor of STAT signaling in human cancer cells. Sophoraflavanone G inhibited tyrosine phosphorylation of STAT proteins in Hodgkin's lymphoma and tyrosine phosphorylation of STAT3 in solid cancer cells by inhibiting phosphorylation of the Janus kinase (JAK) proteins, Src family tyrosine kinases, such as Lyn and Src, Akt, and ERK1/2. In addition, sophoraflavanone G inhibited STAT5 phosphorylation in murine-bone-marrow-derived pro-B cells transfected with translocated Ets Leukemia (TEL)-JAKs and cytokine-induced rat pre-T lymphoma cells, as well as STAT5b reporter activity in TEL-JAKs and STAT5b reporter systems. Sophoraflavanone G also inhibited nuclear factor-κB (NF-κB) signaling in multiple myeloma cells. Furthermore, sophoraflavanone G inhibited cancer cell proliferation and induced apoptosis by regulating the expression of apoptotic and anti-apoptotic proteins. Our data suggest that sophoraflavanone G is a novel small-molecule inhibitor of STAT signaling by targeting upstream signals of STATs that may have therapeutic potential for cancers caused by persistently activated STAT proteins. Copyright © 2013 Elsevier Inc. All rights reserved.

Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

PubMed Central

Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

1999-01-01

We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

Ursodeoxycholic Acid Induces Death Receptor-mediated Apoptosis in Prostate Cancer Cells

PubMed Central

Lee, Won Sup; Jung, Ji Hyun; Panchanathan, Radha; Yun, Jeong Won; Kim, Dong Hoon; Kim, Hye Jung; Kim, Gon Sup; Ryu, Chung Ho; Shin, Sung Chul; Hong, Soon Chan; Choi, Yung Hyun; Jung, Jin-Myung

2017-01-01

Background Bile acids have anti-cancer properties in a certain types of cancers. We determined anticancer activity and its underlying molecular mechanism of ursodeoxycholic acid (UDCA) in human DU145 prostate cancer cells. Methods Cell viability was measured with an MTT assay. UDCA-induced apoptosis was determined with flow cytometric analysis. The expression levels of apoptosis-related signaling proteins were examined with Western blotting. Results UDCA treatment significantly inhibited cell growth of DU145 in a dose-dependent manner. It induced cellular shrinkage and cytoplasmic blebs and accumulated the cells with sub-G1 DNA contents. Moreover, UDCA activated caspase 8, suggesting that UDCA-induced apoptosis is associated with extrinsic pathway. Consistent to this finding, UDCA increased the expressions of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor, death receptor 4 (DR4) and death receptor 5 (DR5), and TRAIL augmented the UDCA-induced cell death in DU145 cells. In addition, UDCA also increased the expressions of Bax and cytochrome c and decreased the expression of Bcl-xL in DU145 cells. This finding suggests that UDCA-induced apoptosis may be involved in intrinsic pathway. Conclusions UDCA induces apoptosis via extrinsic pathway as well as intrinsic pathway in DU145 prostate cancer cells. UDCA may be a promising anti-cancer agent against prostate cancer. PMID:28382282

Sulforaphane-induced apoptosis in Xuanwei lung adenocarcinoma cell line XWLC-05.

PubMed

Zhou, Lan; Yao, Qian; Li, Yan; Huang, Yun-Chao; Jiang, Hua; Wang, Chuan-Qiong; Fan, Lei

2017-01-01

Xuanwei district in Yunnan Province has the highest incidence of lung cancer in China, especially among non-smoking women. Cruciferous vegetables can reduce lung cancer risk by prompting a protective mechanism against respiratory tract inflammation caused by air pollution, and are rich in sulforaphane, which can induce changes in gene expression. We investigated the effect of sulforaphane-induced apoptosis in Xuanwei lung adenocarcinoma cell line (XWCL-05) to explore the value of sulforaphane in lung cancer prevention and treatment. Cell growth inhibition was determined by methyl thiazolyl tetrazolium assay; cell morphology and apoptosis were observed under transmission electron microscope; cell cycle and apoptosis rates were detected using flow cytometry; B-cell lymphoma 2 (Bcl-2) and Bcl-2-like protein 4 (Bax) messenger RNA expression were determined by quantitative PCR; and p53, p73, p53 upregulated modulator of apoptosis (PUMA), Bax, Bcl-2, and caspase-9 protein expression were detected by Western blotting. Sulforaphane inhibited XWLC-05 cell growth with inhibitory concentration (IC) 50 of 4.04, 3.38, and 3.02 μg/mL at 24, 48, and 72 hours, respectively. Sulforaphane affected the XWLC-05 cell cycle as cells accumulated in the G2/M phase. The proportion of apoptotic cells observed was 27.6%. Compared with the control, the sulforaphane group showed decreased Bcl-2 and p53 expression, and significantly increased p73, PUMA, Bax, and caspase-9 protein expression (P < 0.05). Sulforaphane induces Xuanwei lung adenocarcinoma cell apoptosis. Its possible mechanism may involve the upregulation of p73 expression and its effector target genes PUMA and Bax in lung cancer cells, downregulation of the anti-apoptotic gene B cl -2, and activation of caspase-9. It may also involve downregulation of the mutant p53 protein. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

Outer membrane vesicles from Neisseria gonorrhoeae target PorB to mitochondria and induce apoptosis

PubMed Central

Elgass, Kirstin D.; Gabriel, Kipros; Dougan, Gordon; Lithgow, Trevor; Heinz, Eva

2018-01-01

Neisseria gonorrhoeae causes the sexually transmitted disease gonorrhoea by evading innate immunity. Colonizing the mucosa of the reproductive tract depends on the bacterial outer membrane porin, PorB, which is essential for ion and nutrient uptake. PorB is also targeted to host mitochondria and regulates apoptosis pathways to promote infections. How PorB traffics from the outer membrane of N. gonorrhoeae to mitochondria and whether it modulates innate immune cells, such as macrophages, remains unclear. Here, we show that N. gonorrhoeae secretes PorB via outer membrane vesicles (OMVs). Purified OMVs contained primarily outer membrane proteins including oligomeric PorB. The porin was targeted to mitochondria of macrophages after exposure to purified OMVs and wild type N. gonorrhoeae. This was associated with loss of mitochondrial membrane potential, release of cytochrome c, activation of apoptotic caspases and cell death in a time-dependent manner. Consistent with this, OMV-induced macrophage death was prevented with the pan-caspase inhibitor, Q-VD-PH. This shows that N. gonorrhoeae utilizes OMVs to target PorB to mitochondria and to induce apoptosis in macrophages, thus affecting innate immunity. PMID:29601598

Zinc finger protein 598 inhibits cell survival by promoting UV-induced apoptosis.

PubMed

Yang, Qiaohong; Gupta, Romi

2018-01-19

UV is one of the major causes of DNA damage induced apoptosis. However, cancer cells adopt alternative mechanisms to evade UV-induced apoptosis. To identify factors that protect cancer cells from UV-induced apoptosis, we performed a genome wide short-hairpin RNA (shRNA) screen, which identified Zinc finger protein 598 (ZNF598) as a key regulator of UV-induced apoptosis. Here, we show that UV irradiation transcriptionally upregulates ZNF598 expression. Additionally, ZNF598 knockdown in cancer cells inhibited UV-induced apoptosis. In our study, we observe that ELK1 mRNA level as well as phosphorylated ELK1 levels was up regulated upon UV irradiation, which was necessary for UV irradiation induced upregulation of ZNF598. Cells expressing ELK1 shRNA were also resistant to UV-induced apoptosis, and phenocopy ZNF598 knockdown. Upon further investigation, we found that ZNF598 knockdown inhibits UV-induced apoptotic gene expression, which matches with decrease in percentage of annexin V positive cell. Similarly, ectopic expression of ZNF598 promoted apoptotic gene expression and also increased annexin V positive cells. Collectively, these results demonstrate that ZNF598 is a UV irradiation regulated gene and its loss results in resistance to UV-induced apoptosis.

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells

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

Park, Jae Hyeon; Hanyang Biomedical Research Institute, Seoul; Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition,more » we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. - Highlights: ► Chlorpyrifos (CPF) is cytotoxic to SH-SY5Y cells ► CPF-induced cytotoxicity is

Oxidative stress involvement in Physalis angulata-induced apoptosis in human oral cancer cells.

PubMed

Lee, H-Z; Liu, W-Z; Hsieh, W-T; Tang, F-Y; Chung, J-G; Leung, Henry W-C

2009-03-01

In this report, we investigated the role of oxidative stress in Physalis angulata-induced apoptosis of human oral cancer cells. P. angulata-induced apoptosis was characterized by nuclear morphological changes, membrane blebbing and activation of caspase-9. Exposure of HSC-3 cells to P. angulata caused production of reactive oxygen species and up-regulation of oxidative stress markers heme oxygenase-1 (HO-1), superoxide dismutase (SOD), heat shock protein 70 (HSP70) and caspase-4. Down-regulation of HO-1, SOD and HSP70 proteins expression by attenuation of oxidative stress, pretreatment with glutathione or N-acetylcysteine, significantly decreased P. angulata-triggered cell death. The present study also demonstrated that the mitochondria and the endoplasmic reticulum are the targets of P. angulata in HSC-3 cells. Our results revealed that: (1) reactive oxygen species may play a dominant role in this process, (2) P. angulata induces oxidative stress in HSC-3 cells, (3) P. angulata-initiated apoptosis is caused through oxidative stress-dependent induction of heme oxygenase-1, Cu/Zn SOD and HSP70 proteins expression and (4) antioxidants inhibited P. angulata-induced cell death through inhibition of the proteins expression of HO-1, Cu/Zn SOD and HSP70.

Crizotinib induces apoptosis and gene expression changes in ALK+ anaplastic large cell lymphoma cell lines; brentuximab synergizes and doxorubicin antagonizes.

PubMed

Hudson, Sandra; Wang, Dongliang; Middleton, Frank; Nevaldine, Barbara H; Naous, Rana; Hutchison, Robert E

2018-04-26

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) shows 60-70% event free survival with standard treatments. Targeted therapies are being tested for increased benefit and/or reduced toxicity, but interactions with standard agents are not well known. We exposed four ALCL cell lines to two targeted agents, crizotinib and brentuximab vedotin, and to two standard agents, doxorubicin and vinblastine. For each agent and combination, we measured apoptosis and expression of approximately 300 previously annotated genes of interest using targeted RNA-sequencing. An aurora kinase inhibitor, alisertib, was similarly tested for gene expression effects. Only crizotinib, alone or in combination, showed significant effects (adjusted P < 0.05) on expression and apoptosis. One hundred and nine of 277 gene expressions showed crizotinib-associated differential expression, mostly downregulation, 62 associated with apoptosis, and 28 associated with both crizotinib and apoptosis. Doxorubicin was antagonistic with crizotinib on gene expression and apoptosis. Brentuximab was synergistic with crizotinib in apoptosis, and not antagonistic in gene expression. Vinblastine also appeared synergistic with crizotinib but did not achieve statistical significance. Alisertib did not show significant expression changes. Our data suggest that crizotinib induces apoptosis through orderly changes in cell signaling associated with ALK inhibition. Expression effects of crizotinib and associated apoptosis are antagonized by doxorubicin, but apoptosis is synergized by brentuximab vedotin and possibly vinblastine. These findings suggest that concurrent use of crizotinib and doxorubicin may be counterproductive, while the pairing of crizotinib with brentuximab (or vinblastine) may increase efficacy. Alisertib did not induce expression changes at cytotoxic dosage. © 2018 Wiley Periodicals, Inc.

[Study on thaspine in inducing apoptosis of A549 cell].

PubMed

Zhang, Yan-min; He, Lang-chong

2007-04-01

To investigate the effect of thaspine on the cellular proliferation, apoptosis and cell cycle in A549 cell line. A549 cell was cultured with different concentrations of thaspine. Cellular proliferation was detected with MTT, apoptosis and cell cycle were checked with Flow Cytometer, and change of microstructure was observed by transmission electron microscope. Thaspine could inhibit the proliferation and induce apoptosis of A549 cell in a time-dose dependent manner. Cell cycle was significantly stopped at the S phase by thaspine with FCM technology. Under electronic microscope, the morphology of A549 cell showed nuclear karyopycnosis, chromatin agglutination and typical apoptotic body when the cell was treated with thaspine. Thaspine has the effects of anti-tumor and inducing apoptosis.

Retrovirus-mediated siRNA targeting TRPM7 gene induces apoptosis in RBL-2H3 cells.

PubMed

Ng, N-M; Jiang, S-P; Lv, Z-Q

2012-09-01

Calcium signaling is important for both normal physiologic processes and pathology of various diseases. Transient receptor potential melastatin 7 (TRPM7) gene has been reported to be a potential candidate for calcium influx. The present study aimed to investigate the possible role of TRPM7 channels in apoptosis in rat basophilic leukemia mast cell line (RBL-2H3), which is widely used in mast cell-associated studies. A recombinant retrovirus vector siRNA targeting rat TRPM7 gene was constructed and identified. Cellular survival was assessed by MTT. Cell apoptosis was evaluated by flow cytometry and TUNEL-FITC/Hoechst 33258 staining. The transfection efficiency by retrovirus vector was about 60%-70%. Transfection with TRPM7 siRNA significantly reduced TRPM7 expression both at mRNA and protein levels. Suppression of TRPM7 expression by siRNA led to significantly decreased cellular survival rates and increased apoptosis rates in RBL-2H3 cells. This study indicates that TRPM7 is involved in the apoptosis process in RBL-2H3 cells.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT.

PubMed

Leszczynska, Katarzyna B; Foskolou, Iosifina P; Abraham, Aswin G; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N; O'Neill, Eric E; Buffa, Francesca M; Hammond, Ester M

2015-06-01

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage-induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain-containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors.

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

PubMed Central

Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

2015-01-01

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

[Phloretin induces apoptosis of BEL-7402 cells in vitro].

PubMed

Luo, Hui; Wang, Ya-jun; Chen, Jie; Liu, Jiang-qin; Zhang, Hai-tao

2008-07-01

To examine the effect of phloretin on apoptosis of BEL-7402 cells. The viability changes of BEL- 7402 cells as a result of phloretin-induced toxicity were analyzed using MTT assay, and the cell morphology changes were observed with fluorescence microscope. Flow cytometry was used to analyze the cell cycle and mitochondrial membrane potential changes, and chromogenic substrate assay performed to detect caspase activity. Phloretin induced obvious cytotoxicity against BEL-7402 cells with IC50 of 89.23 microg/mL. The growth curve demonstrated decreased growth of the cells as phloretin concentration increased. Cell apoptosis occurred 24 h after treatment with 40-160 microg/mL phloretin. Morphological, the cells exposed to phloretin exhibited nuclear chromatin condensation and increased fluorescence intensity. The activity of caspase-9 reached the peak level 12 h after phloretin exposure, and leak levels of caspase-6 and caspase-3 activities occurred 18 and 24 h after the exposure, respectively. Phloretin can induce BEL-7402 cell apoptosis though the mitochondrial pathway.

[Novel Anticancer Strategy Targeting Switch Mechanisms in Two Types of Cell Death: Necrosis and Apoptosis].

PubMed

Sato, Akira

2017-01-01

 Two types of cell death, necrosis and apoptosis, are defined in terms of cell death morphological features. We have been studying the mechanisms by which cell death processes are switched during the treatment of mouse tumor FM3A with anticancer, 5-fluoro-2'-deoxyuridine (FUdR): it induces original clone F28-7 to necrosis, but its sub-clone F28-7-A to apoptosis. We identified several such switch regulators of cell death: heat shock protein 90 (HSP90), lamin-B1, cytokeratin-19, and activating transcription factor 3 (ATF3), by using transcriptomic, proteomic analyses and siRNA screening. For example, the inhibition of HSP90 by its inhibitor geldanamycin in F28-7 caused a shift from necrosis to apoptosis. We also observed that the knockdown of lamin-B1, cytokeratin-19, or ATF3 expression in F28-7 resulted in a shift from necrosis to apoptosis. Recently, we used microRNA (miRNA, miR) microarray analyses to investigate the miRNA expression profiles in these sister cells. The miR-351 and miR-743a were expressed at higher levels in F28-7-A than in F28-7. Higher expression of miR-351 or miR-743a in F28-7, induced by transfecting the miR mimics, resulted in a switch of cell death mode: necrosis to apoptosis. Furthermore, transfection of an miR-351 inhibitor into F28-7-A resulted in morphological changes, and mode of cell death from apoptosis to necrosis. These findings suggest that the identified cell death regulators may have key roles in switching cell death mode. Possible mechanisms involving cell death regulators in the switch of necrosis or apoptosis are discussed. We propose a novel anticancer strategy targeting the switch regulators of necrosis or apoptosis.

Targeting autophagy enhances apatinib-induced apoptosis via endoplasmic reticulum stress for human colorectal cancer.

PubMed

Cheng, Xi; Feng, Haoran; Wu, Haoxuan; Jin, Zhijian; Shen, Xiaonan; Kuang, Jie; Huo, Zhen; Chen, Xianze; Gao, Haoji; Ye, Feng; Ji, Xiaopin; Jing, Xiaoqian; Zhang, Yaqi; Zhang, Tao; Qiu, Weihua; Zhao, Ren

2018-05-30

Apatinib, a novel tyrosine kinase inhibitor (TKI), has been confirmed for its efficacy and safety in the treatment of advanced gastric carcinoma and some other solid tumors. However, the direct functional mechanisms of tumor lethality mediated by apatinib have not yet been fully characterized, and the precise mechanisms of drug resistance are largely unknown. Here, in this study, we demonstrated that apatinib could induce both apoptosis and autophagy in human colorectal cancer (CRC) via a mechanism that involved endoplasmic reticulum (ER) stress. Moreover, activation of the IRE1α pathway from apatinib-induced ER stress is responsible for the induction of autophagy; however, blocking autophagy could enhance the apoptosis in apatinib-treated human CRC cell lines. Furthermore, the combination of apatinib with autophagy inhibitor chloroquine (CQ) tends to have the most significant anti-tumor effect of CRC both in vitro and in vivo. Overall, our data show that because apatinib treatment could induce ER stress-related apoptosis and protective autophagy in human CRC cell lines, targeting autophagy is a promising therapeutic strategy to relieve apatinib drug resistance in CRC. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Platinum Nanoparticles Induce Apoptosis on Raw 264.7 Macrophage Cells.

PubMed

Loan, Ta Thi; Do, Le Thanh; Yoo, Hoon

2018-02-01

The cellular effects of platinum nanoparticles (PNP05, average size of 5 nm, and PNP30, average size of 30 nm) were investigated on murine leukemia Raw 264.7 cells. Cells treated with various concentrations of PNPs showed size-dependent cytotoxicity in an MTT assay with PNP5 of smaller nanoparticles higher toxicity than PNP30. Investigations on cell morphology, Annexin V assay, DNA fragmentation and the activity of caspase-3/-7 showed that PNPs induced apoptosis on Raw 264.7 cells by changing cell morphology and density, increasing cell population in apoptosis and causing nucleus fragmentation. Further study on caspase activity by Western blotting revealed that the apoptosis was induced by the activation of caspase-3 and -7. In addition, PNPs inactivated DNA repair system, generating dose-dependent DNA ladder bands on agarose gel electrophoresis. Taken together, PNPs triggered cytotoxicity on Raw 264.7 cells by suppressing cell growth/survival and inducing apoptosis.

The Immunomodulatory Small Molecule Imiquimod Induces Apoptosis in Devil Facial Tumour Cell Lines.

PubMed

Patchett, Amanda L; Darby, Jocelyn M; Tovar, Cesar; Lyons, A Bruce; Woods, Gregory M

2016-01-01

The survival of the Tasmanian devil (Sarcophilus harrisii) is threatened by devil facial tumour disease (DFTD). This transmissible cancer is usually fatal, and no successful treatments have been developed. In human studies, the small immunomodulatory molecule imiquimod is a successful immunotherapy, activating anti-tumour immunity via stimulation of toll-like receptor-7 (TLR7) signaling pathways. In addition, imiquimod is a potent inducer of apoptosis in human tumour cell lines via TLR7 independent mechanisms. Here we investigate the potential of imiquimod as a DFTD therapy through analysis of treated DFTD cell lines and Tasmanian devil fibroblasts. WST-8 proliferation assays and annexin V apoptosis assays were performed to monitor apoptosis, and changes to the expression of pro- and anti-apoptotic genes were analysed using qRT-PCR. Our results show that DFTD cell lines, but not Tasmanian devil fibroblasts, are sensitive to imiquimod-induced apoptosis in a time and concentration dependent manner. Induction of apoptosis was accompanied by down-regulation of the anti-apoptotic BCL2 and BCLXL genes, and up-regulation of the pro-apoptotic BIM gene. Continuous imiquimod treatment was required for these effects to occur. These results demonstrate that imiquimod can deregulate DFTD cell growth and survival in direct and targeted manner. In vivo, this may increase DFTD vulnerability to imiquimod-induced TLR7-mediated immune responses. Our findings have improved the current knowledge of imiquimod action in tumour cells for application to both DFTD and human cancer therapy.

The functional curcumin liposomes induce apoptosis in C6 glioblastoma cells and C6 glioblastoma stem cells in vitro and in animals.

PubMed

Wang, Yahua; Ying, Xue; Xu, Haolun; Yan, Helu; Li, Xia; Tang, Hui

2017-01-01

Glioblastoma is a kind of malignant gliomas that is almost impossible to cure due to the poor drug transportation across the blood-brain barrier and the existence of glioma stem cells. We prepared a new kind of targeted liposomes in order to improve the drug delivery system onto the glioma cells and induce the apoptosis of glioma stem cells afterward. In this experiment, curcumin was chosen to kill gliomas, while quinacrine was used to induce apoptosis of the glioma stem cells. Also, p -aminophenyl-α-D-mannopyranoside could facilitate the transport of liposomes across the blood-brain barrier and finally target the brain glioma cells. The cell experiments in vitro indicated that the targeted liposomes could significantly improve the anti-tumor effects of the drugs, while enhancing the uptake effects, apoptosis effects, and endocytic effects of C6 glioma cells and C6 glioma stem cells. Given the animal experiments in vivo, we discovered that the targeted liposomes could obviously increase the survival period of brain glioma-bearing mice and inhibit the growth of gliomas. In summary, curcumin and quinacrine liposomes modified with p -aminophenyl-α-D-mannopyranoside is a potential preparation to treat brain glioma cells and brain glioma stem cells.

The functional curcumin liposomes induce apoptosis in C6 glioblastoma cells and C6 glioblastoma stem cells in vitro and in animals

PubMed Central

Wang, Yahua; Ying, Xue; Xu, Haolun; Yan, Helu; Li, Xia; Tang, Hui

2017-01-01

Glioblastoma is a kind of malignant gliomas that is almost impossible to cure due to the poor drug transportation across the blood–brain barrier and the existence of glioma stem cells. We prepared a new kind of targeted liposomes in order to improve the drug delivery system onto the glioma cells and induce the apoptosis of glioma stem cells afterward. In this experiment, curcumin was chosen to kill gliomas, while quinacrine was used to induce apoptosis of the glioma stem cells. Also, p-aminophenyl-α-D-mannopyranoside could facilitate the transport of liposomes across the blood–brain barrier and finally target the brain glioma cells. The cell experiments in vitro indicated that the targeted liposomes could significantly improve the anti-tumor effects of the drugs, while enhancing the uptake effects, apoptosis effects, and endocytic effects of C6 glioma cells and C6 glioma stem cells. Given the animal experiments in vivo, we discovered that the targeted liposomes could obviously increase the survival period of brain glioma-bearing mice and inhibit the growth of gliomas. In summary, curcumin and quinacrine liposomes modified with p-aminophenyl-α-D-mannopyranoside is a potential preparation to treat brain glioma cells and brain glioma stem cells. PMID:28260885

miR-421 induces cell proliferation and apoptosis resistance in human nasopharyngeal carcinoma via downregulation of FOXO4

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

Chen, Liang; Department of Otolaryngology, Guangzhou General Hospital of PLA Guangzhou Command, Guangzhou 510010; Tang, Yanping

2013-06-14

Highlights: •miR-421 is upregulated in nasopharyngeal carcinoma. •miR-421 induces cell proliferation and apoptosis resistance. •FOXO4 is a direct and functional target of miR-421. -- Abstract: microRNAs have been demonstrated to play important roles in cancer development and progression. Hence, identifying functional microRNAs and better understanding of the underlying molecular mechanisms would provide new clues for the development of targeted cancer therapies. Herein, we reported that a microRNA, miR-421 played an oncogenic role in nasopharyngeal carcinoma. Upregulation of miR-421 induced, whereas inhibition of miR-421 repressed cell proliferation and apoptosis resistance. Furthermore, we found that upregulation of miR-421 inhibited forkhead box proteinmore » O4 (FOXO4) signaling pathway following downregulation of p21, p27, Bim and FASL expression by directly targeting FOXO4 3′UTR. Additionally, we demonstrated that FOXO4 expression is critical for miR-421-induced cell growth and apoptosis resistance. Taken together, our findings not only suggest that miR-421 promotes nasopharyngeal carcinoma cell proliferation and anti-apoptosis, but also uncover a novel regulatory mechanism for inactivation of FOXO4 in nasopharyngeal carcinoma.« less

Raman spectrum reveals the cell cycle arrest of Triptolide-induced leukemic T-lymphocytes apoptosis

NASA Astrophysics Data System (ADS)

Zhang, Daosen; Feng, Yanyan; Zhang, Qinnan; Su, Xin; Lu, Xiaoxu; Liu, Shengde; Zhong, Liyun

2015-04-01

Triptolide (TPL), a traditional Chinese medicine extract, possesses anti-inflammatory and anti-tumor properties. Though some research results have implicated that Triptolide (TPL) can be utilized in the treatment of leukemia, it remains controversial about the mechanism of TPL-induced leukemic T-lymphocytes apoptosis. In this study, combining Raman spectroscopic data, principal component analysis (PCA) and atomic force microscopy (AFM) imaging, both the biochemical changes and morphological changes during TPL-induced cell apoptosis were presented. In contrast, the corresponding data during Daunorubicin (DNR)-induced cell apoptosis was also exhibited. The obtained results showed that Raman spectral changes during TPL-induced cell apoptosis were greatly different from DNR-induced cell apoptosis in the early stage of apoptosis but revealed the high similarity in the late stage of apoptosis. Moreover, above Raman spectral changes were respectively consistent with the morphological changes of different stages during TPL-induced apoptosis or DNR-induced apoptosis, including membrane shrinkage and blebbing, chromatin condensation and the formation of apoptotic bodies. Importantly, it was found that Raman spectral changes with TPL-induced apoptosis or DNR-induced apoptosis were respectively related with the cell cycle G1 phase arrest or G1 and S phase arrest.

MicroRNA-142-3p Induces Atherosclerosis-Associated Endothelial Cell Apoptosis by Directly Targeting Rictor.

PubMed

Qin, Bing; Shu, Yaqing; Long, Ling; Li, Haiyan; Men, Xuejiao; Feng, Li; Yang, Huan; Lu, Zhengqi

2018-06-27

Atherosclerosis, a multifactorial chronic disease, is the main cause of death and impairment in the world. Endothelial cells (ECs) apoptosis plays a crucial role in the onset and development of atherosclerosis, whereas the underlying molecular mechanisms are unclear. MicroRNA-142-3p (miR-142-3p) is a well-defined tumor suppressor in several types of cancer, while the role of miR-142-3p in ECs apoptosis and the development of atherosclerosis has yet to be elucidated. Therefore, the present study aimed to investigate the role of miR-142-3p in ECs apoptosis during atherosclerosis and the underlying mechanism. Human aortic endothelial cells (HAECs) were treated with oxidized low-density lipoprotein (ox-LDL). The expression level of miR-142-3p was detected using qRT-PCR. Apoptosis was determined via flow cytometry and Caspase-3 activity assay. Prediction of the binding between miR-142-3p and 3'-UTR of Rictor mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay. The effects of miR-142-3p on endothelial apoptosis and atherosclerosis were further analyzed in an in vivo model using ApoE-/- mice fed with high-fat diet (HFD). MiR-142-3p expression was substantially up-regulated during the ox-LDL-elicited apoptosis in HAECs. Forced expression of miR-142-3p exacerbated apoptosis in ECs whereas inhibition of miR-142-3p could partly alleviate apoptotic cell death mediated by ox-LDL. Further analysis identified Rictor as a direct target of miR-142-3p, and Rictor knockdown abolished the anti-apoptotic effect of miR-142-3p inhibitor. Moreover, the Akt/endothelial nitric oxide synthase (eNOS) signaling pathway was found to mediate the beneficial effect of miR-142-3p inhibitor on endothelial apoptosis. Finally, systemic treatment with miR-142-3p antagomir attenuated endothelial apoptosis and retarded the progression of atherosclerosis in the aorta of ApoE-/- mice. Down-regulation of miR-142-3p inhibited ECs apoptosis and atherosclerotic

Research Advances on Pathways of Nickel-Induced Apoptosis

PubMed Central

Guo, Hongrui; Chen, Lian; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Wang, Xun; Wu, Bangyuan

2015-01-01

High concentrations of nickel (Ni) are harmful to humans and animals. Ni targets a number of organs and produces multiple toxic effects. Apoptosis is important in Ni-induced toxicity of the kidneys, liver, nerves, and immune system. Apoptotic pathways mediated by reactive oxygen species (ROS), mitochondria, endoplasmic reticulum (ER), Fas, and c-Myc participate in Ni-induced cell apoptosis. However, the exact mechanism of apoptosis caused by Ni is still unclear. Understanding the mechanism of Ni-induced apoptosis may help in designing measures to prevent Ni toxicity. PMID:26703593

MiR-214 regulates oral cancer KB cell apoptosis through targeting RASSF5.

PubMed

Li, T K; Yin, K; Chen, Z; Bao, Y; Zhang, S X

2017-03-08

Ras association domain family member 5 (RASSF5), a member of the Ras association domain family, induces cell apoptosis by phosphorylating FOXO3a, which triggers target gene BIM (pro-apoptotic factor) activation. MiR-214 is overexpressed in oral cancer tissue, indicating its possible involvement in oral cancer pathogenesis. Bioinformatics analysis has revealed a complimentary sequence between miR-214 and the 3'-UTR of RASSF5 mRNA. However, whether miR-124 regulates RASSF5 in oral cancer remains poorly understood. We aimed to investigate the role of miR-214 in RASSF5 expression regulation in oral cancer. Tumor and paracarcinoma tissues were obtained from 48 oral cancer patients to examine miR-214 and RASSF5 expression. The relationship between miR-214 and RASSF5 was investigated by dual luciferase reporter gene assay. Oral cancer KB cells were cultured in vitro and divided into inhibitor NC, miR-214 inhibitor, Scramble-pMD18, RASSF5-pMD18, and miR-214 inhibitor + RASSF5-pMD18 groups. Caspase 3 activity, cell apoptosis, and total protein expression were measured by spectrophotometry, flow cytometry, and western blot, respectively. MiR-214 expression was significantly increased, while that of RASSF5 decreased in oral cancer tumor tissues compared to paracarcinoma tissues. Luciferase assay showed that miR-214 suppressed RASSF5 expression by targeting its 3'-UTR. Down-regulation of miR-214 and/or enhancement of RASSF5 expression markedly increased FOXO3a phosphorylation, BIM expression, caspase 3 activity, and apoptosis. In conclusion, miR-214 expression was elevated and RASSF5 was down-regulated in oral cancer. Moreover, miR-214 regulated KB cell apoptosis through targeted inhibition of RASSF5 expression, FOXO3a phosphorylation, and BIM expression, suggesting its possible application as a novel therapeutic oral cancer target.

Ap4A induces apoptosis in human cultured cells.

PubMed

Vartanian, A; Alexandrov, I; Prudowski, I; McLennan, A; Kisselev, L

1999-07-30

Diadenosine oligophosphates (Ap(n)A) have been proposed as intracellular and extracellular signaling molecules in animal cells. The ratio of diadenosine 5',5'''-P1,P3-triphosphate to diadenosine 5',5'''-P1,P4-tetraphosphate (Ap3A/Ap4A) is sensitive to the cellular status and alters when cultured cells undergo differentiation or are treated with interferons. In cells undergoing apoptosis induced by DNA topoisomerase II inhibitor VP16, the concentration of Ap3A decreases significantly while that of Ap4A increases. Here, we have examined the effects of exogenously added Ap3A and Ap4A on apoptosis and morphological differentiation. Penetration of Ap(n)A into cells was achieved by cold shock. Ap4A at 10 microM induced programmed cell death in human HL60, U937 and Jurkat cells and mouse VMRO cells and this effect appeared to require Ap4A breakdown as hydrolysis-resistant analogues of Ap4A were inactive. On its own, Ap3A induced neither apoptosis nor cell differentiation but did display strong synergism with the protein kinase C activators 12-deoxyphorbol-13-O-phenylacetate and 12-deoxyphorbol-13-O-phenylacetate-20-acetate in inducing differentiation of HL60 cells. We propose that Ap4A and Ap3A are physiological antagonists in determination of the cellular status: Ap4A induces apoptosis whereas Ap3A is a co-inductor of differentiation. In both cases, the mechanism of signal transduction remains unknown.

Troglitazone induced apoptosis via PPARγ activated POX-induced ROS formation in HT29 cells.

PubMed

Wang, Jing; Lv, XiaoWen; Shi, JiePing; Hu, XiaoSong; DU, YuGuo

2011-08-01

In order to investigate the potential mechanisms in troglitazone-induced apoptosis in HT29 cells, the effects of PPARγ and POX-induced ROS were explored. [3- (4, 5)-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay, Annexin V and PI staining using FACS, plasmid transfection, ROS formation detected by DCFH staining, RNA interference, RT-PCR & RT-QPCR, and Western blotting analyses were employed to investigate the apoptotic effect of troglitazone and the potential role of PPARγ pathway and POX-induced ROS formation in HT29 cells. Troglitazone was found to inhibit the growth of HT29 cells by induction of apoptosis. During this process, mitochondria related pathways including ROS formation, POX expression and cytochrome c release increased, which were inhibited by pretreatment with GW9662, a specific antagonist of PPARγ. These results illustrated that POX upregulation and ROS formation in apoptosis induced by troglitazone was modulated in PPARγ-dependent pattern. Furthermore, the inhibition of ROS and apoptosis after POX siRNA used in troglitazone-treated HT29 cells indicated that POX be essential in the ROS formation and PPARγ-dependent apoptosis induced by troglitazone. The findings from this study showed that troglitazone-induced apoptosis was mediated by POX-induced ROS formation, at least partly, via PPARγ activation. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

PubMed

Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

2015-01-09

To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting.

Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells

PubMed Central

Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

2015-01-01

To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting. PMID:25571970

MiR-467a is Upregulated in Radiation-Induced Mouse Thymic Lymphomas and Regulates Apoptosis by Targeting Fas and Bax

PubMed Central

Gao, Fu; Chen, Song; Sun, Mingjuan; Mitchel, Ronald E.J.; Li, Bailong; Chu, Zhiyong; Cai, Jianming; Liu, Cong

2015-01-01

It has been reported dysregulation of certain microRNAs (miRNAs / miRs) is involved in tumorigenesis. However, the miRNAs associated with radiocarcinogenesis remain undefined. In this study, we validated the upregulation of miR-467a in radiation-induced mouse thymic lymphoma tissues. Then, we investigated whether miR-467a functions as an oncogenic miRNA in thymic lymphoma cells. For this purpose, we assessed the biological effect of miR-467a on thymic lymphoma cells. Using miRNA microarray, we found four miRNAs (miR-467a, miR-762, miR-455 and miR-714) were among the most upregulated (>4-fold) miRNAs in tumor tissues. Bioinformatics prediction suggests miR-467a may potentially regulate apoptosis pathway via targeting Fas and Bax. Consistently, in miR-467a-transfected cells, both proliferation and colony formation ability were significantly increased with decrease of apoptosis rate, while, in miR-467a-knockdown cells, proliferation was suppressed with increase of apoptosis rate, indicating that miR-467a may be involved in the regulation of apoptosis. Furthermore, miR-467a-knockdown resulted in smaller tumors and better prognosis in an in vivo tumor-transplanted model. To explain the mechanism of apoptosis suppression by miR-467a, we explore the expression of candidate target genes (Fas and Bax) in miR-467a-transfected relative to negative control transfected cells using flow cytometry and immunoblotting. Fas and Bax were commonly downregulated in miR-467a-transfected EL4 and NIH3T3 cells, and all of the genes harbored miR-467a target sequences in the 3'UTR of their mRNA. Fas and Bax were actually downregulated in radiation-induced thymic lymphoma tissues, and therefore both were identified as possible targets of miR-467a in thymic lymphoma. To ascertain whether downregulation of Fas and / or Bax is involved in apoptosis suppression by miR-467a, we transfected vectors expressing Fas and Bax into miR-467a-upregulated EL4 cells. Then we found that both Fas- and Bax

Low-power laser irradiation inhibits amyloid beta-induced cell apoptosis

NASA Astrophysics Data System (ADS)

Zhang, Heng; Wu, Shengnan

2011-03-01

The deposition and accumulation of amyloid-β-peptide (Aβ) in the brain are considered a pathological hallmark of Alzheimer's disease(AD). Apoptosis is a contributing pathophysiological mechanism of AD. Low-power laser irradiation (LPLI), a non-damage physical therapy, which has been used clinically for decades of years, is shown to promote cell proliferation and prevent apoptosis. Recently, low-power laser irradiation (LPLI) has been applied to moderate AD. In this study, Rat pheochromocytoma (PC12) cells were treated with amyloid beta 25-35 (Aβ25-35) for induction of apoptosis before LPLI treatment. We measured cell viability with CCK-8 according to the manufacture's protocol, the cell viability assays show that low fluence of LPLI (2 J/cm2 ) could inhibit the cells apoptosis. Then using statistical analysis of proportion of apoptotic cells by flow cytometry based on Annexin V-FITC/PI, the assays also reveal that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis. Taken together, we demonstrated that low fluence of LPLI (2 J/cm2 ) could inhibit the Aβ-induced cell apoptosis, these results directly point to a therapeutic strategy for the treatment of AD through LPLI.

A microtubule inhibitor, ABT-751, induces autophagy and delays apoptosis in Huh-7 cells.

PubMed

Wei, Ren-Jie; Lin, Su-Shuan; Wu, Wen-Ren; Chen, Lih-Ren; Li, Chien-Feng; Chen, Han-De; Chou, Chien-Ting; Chen, Ya-Chun; Liang, Shih-Shin; Chien, Shang-Tao; Shiue, Yow-Ling

2016-11-15

The objective was to investigate the upstream mechanisms of apoptosis which were triggered by a novel anti-microtubule drug, ABT-751, in hepatocellular carcinoma-derived Huh-7 cells. Effects of ABT-751 were evaluated by immunocytochemistry, flow cytometric, alkaline comet, soft agar, immunoblotting, CytoID, green fluorescent protein-microtubule associated protein 1 light chain 3 beta detection, plasmid transfection, nuclear/cytosol fractionation, coimmunoprecipitation, quantitative reverse transcription-polymerase chain reaction, small-hairpin RNA interference and mitochondria/cytosol fractionation assays. Results showed that ABT-751 caused dysregulation of microtubule, collapse of mitochondrial membrane potential, generation of reactive oxygen species (ROS), DNA damage, G 2 /M cell cycle arrest, inhibition of anchorage-independent cell growth and apoptosis in Huh-7 cells. ABT-751 also induced early autophagy via upregulation of nuclear TP53 and downregulation of the AKT serine/threonine kinase (AKT)/mechanistic target of rapamycin (MTOR) pathway. Through modulation of the expression levels of DNA damage checkpoint proteins and G 2 /M cell cycle regulators, ABT-751 induced G 2 /M cell cycle arrest. Subsequently, ABT-751 triggered apoptosis with marked downregulation of B-cell CLL/lymphoma 2, upregulation of mitochondrial BCL2 antagonist/killer 1 and BCL2 like 11 protein levels, and cleavages of caspase 8 (CASP8), CASP9, CASP3 and DNA fragmentation factor subunit alpha proteins. Suppression of ROS significantly decreased ABT-751-induced autophagic and apoptotic cells. Pharmacological inhibition of autophagy significantly increased the percentages of ABT-751-induced apoptotic cells. The autophagy induced by ABT-751 plays a protective role to postpone apoptosis by exerting adaptive responses following microtubule damage, ROS and/or impaired mitochondria. Copyright © 2016 Elsevier Inc. All rights reserved.

RITA enhances chemosensivity of pre-B ALL cells to doxorubicin by inducing p53-dependent apoptosis.

PubMed

Kazemi, Ahmad; Safa, Majid; Shahbazi, Atefeh

2011-07-01

The use of low-molecular-weight, non-peptidic molecules that disrupt the interaction between the p53 tumor suppressor and its negative regulator MDM2 has provided a promising alternative for the treatment of different types of cancer. Here, we used small-molecule reactivation of p53 and induction of tumor cell apoptosis (RITA) to sensitize leukemic NALM-6 cells to doxorubicin by upregulating p53 protein. RITA alone effectively inhibited NALM-6 cells viability in dose-dependent manner as measured by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay and induced apoptosis as evaluated by flow cytometry, whereas RITA in combination with doxorubicin enhanced NALM-6 cells to doxorubicin-sensitivity and promoted doxorubicin induced apoptosis. Levels of p53 protein and its proapoptotic target genes, quantified by western blot and real-time PCR respectively, showed that expression of p53 was significantly increased after RITA treatment. Using p53 inhibitors PFT-alpha and PFT-mu it was shown that p53-mediated apoptosis induced by RITA can be regulated by both p53-transcription-dependent and -independent pathways. Moreover, RITA-induced apoptosis was accompanied by the activation of caspase-3 and PARP cleavage. Therefore, exploiting synergistic effects between RITA and chemotherapeutics might be an effective clinical strategy for leukemia chemotherapy.

Bim is a crucial regulator of apoptosis induced by Mycobacterium tuberculosis

PubMed Central

Aguiló, N; Uranga, S; Marinova, D; Martín, C; Pardo, J

2014-01-01

Mycobacterium tuberculosis, the causative agent of tuberculosis, induces apoptosis in infected macrophages in vitro and in vivo. However, the molecular mechanism controlling this process is not known. In order to study the involvement of the mitochondrial apoptotic pathway in M. tuberculosis-induced apoptosis, we analysed cell death in M. tuberculosis-infected embryonic fibroblasts (MEFs) derived from different knockout mice for genes involved in this route. We found that apoptosis induced by M. tuberculosis is abrogated in the absence of Bak and Bax, caspase 9 or the executioner caspases 3 and 7. Notably, we show that MEF deficient in the BH3-only BCL-2-interacting mediator of cell death (Bim) protein were also resistant to this process. The relevance of these results has been confirmed in the mouse macrophage cell line J774, where cell transfection with siRNA targeting Bim impaired apoptosis induced by virulent mycobacteria. Notably, only infection with a virulent strain, but not with attenuated ESX-1-defective strains, such as Bacillus Calmette-Guerin and live-attenuated M. tuberculosis vaccine strain MTBVAC, induced Bim upregulation and apoptosis, probably implicating virulence factor early secreted antigenic target 6-kDa protein in this process. Our results suggest that Bim upregulation and apoptosis is mediated by the p38MAPK-dependent pathway. Our findings show that Bim is a master regulator of apoptosis induced by M. tuberculosis. PMID:25032866

Salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells

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

Hu, Xiaolan, E-mail: huxiaolan1998@yahoo.com.cn; Zhang, Xianqi; Qiu, Shuifeng

2010-07-16

Research highlights: {yields} Salidroside inhibits the growth of human breast cancer cells. {yields} Salidroside induces cell-cycle arrest of human breast cancer cells. {yields} Salidroside induces apoptosis of human breast cancer cell lines. -- Abstract: Recently, salidroside (p-hydroxyphenethyl-{beta}-D-glucoside) has been identified as one of the most potent compounds isolated from plants of the Rhodiola genus used widely in traditional Chinese medicine, but pharmacokinetic data on the compound are unavailable. We were the first to report the cytotoxic effects of salidroside on cancer cell lines derived from different tissues, and we found that human breast cancer MDA-MB-231 cells (estrogen receptor negative) weremore » sensitive to the inhibitory action of low-concentration salidroside. To further investigate the cytotoxic effects of salidroside on breast cancer cells and reveal possible ER-related differences in response to salidroside, we used MDA-MB-231 cells and MCF-7 cells (estrogen receptor-positive) as models to study possible molecular mechanisms; we evaluated the effects of salidroside on cell growth characteristics, such as proliferation, cell cycle duration, and apoptosis, and on the expression of apoptosis-related molecules. Our results demonstrated for the first time that salidroside induces cell-cycle arrest and apoptosis in human breast cancer cells and may be a promising candidate for breast cancer treatment.« less

HER2-targeted recombinant protein immuno-caspase-6 effectively induces apoptosis in HER2-overexpressing GBM cells in vitro and in vivo.

PubMed

Zhang, Leiming; Ren, Junlin; Zhang, Hangyu; Cheng, Gang; Xu, Yanming; Yang, Shuangwu; Dong, Chao; Fang, Dandong; Zhang, Jianning; Yang, Angang

2016-11-01

Glioblastoma multiforme (GBM), which is associated with a high rate of morbidity and mortality, is among the most malignant and treatment-refractory neoplasms in human adults. As GBM is highly resistant to conventional therapies, immunotherapies are a promising treatment candidate. HER2 is an attractive target for GBM immunotherapy, as its expression is highly associated with various types of GBM. We previously reported that a novel HER2-targeted recombinant protein e23sFv-Fdt-casp6 has an antitumor effect on HER2-positive gastric cancer cells. In this study, we established a genetically modified Chinese hamster ovary cell line, which produced and secreted e23sFv-Fdt-casp6 proteins. Following specific binding to and internalization into HER2-overexpressing tumor cells, the e23sFv-Fdt-casp6 protein induced tumor cell apoptosis and inhibited the proliferation of HER2-overexpressing A172 and U251MG cells in vitro, but not in U87MG cells with undetectable HER2. The e23sFv-Fdt-casp6 gene was introduced into severe combined immunodeficient mice bearing human glioblastoma xenografts by using intramuscular injections of a liposome-encapsulated vector. The recombinant protein e23sFv-Fdt-casp6 specifically targeted tumor cells and induced apoptosis, thereby leading to potent inhibition of tumor growth and prolonged the survival time of tumor-bearing mice. We concluded that e23sFv‑Fdt‑casp6 represents a promising HER2-targeted treatment option for human gliomas.

HGF Secreted by Activated Kupffer Cells Induces Apoptosis of Plasmodium-Infected Hepatocytes

PubMed Central

Gonçalves, Lígia Antunes; Rodo, Joana; Rodrigues-Duarte, Lurdes; de Moraes, Luciana Vieira; Penha-Gonçalves, Carlos

2017-01-01

Malaria liver stage infection is an obligatory parasite development step and represents a population bottleneck in Plasmodium infections, providing an advantageous target for blocking parasite cycle progression. Parasite development inside hepatocytes implies a gross cellular insult evoking innate host responses to counteract intra-hepatocytic infection. Using primary hepatocyte cultures, we investigated the role of Kupffer cell-derived hepatocyte growth factor (HGF) in malaria liver stage infection. We found that Kupffer cells from Plasmodium-infected livers produced high levels of HGF, which trigger apoptosis of infected hepatocytes through a mitochondrial-independent apoptosis pathway. HGF action in infected hepatocyte primary cultures results in a potent reduction of parasite yield by specifically sensitizing hepatocytes carrying established parasite exo-erythrocytic forms to undergo apoptosis. This apoptosis mechanism is distinct from cell death that is spontaneously induced in infected cultures and is governed by Fas signaling modulation through a mitochondrial-dependent apoptosis pathway. This work indicates that HGF and Fas signaling pathways are part of an orchestrated host apoptosis response that occurs during malaria liver stage infection, decreasing the success of infection of individual hepatocytes. Our results raise the hypothesis that paracrine signals derived from Kupffer cell activation are implicated in directing death of hepatocytes infected with the malaria parasite. PMID:28220125

HGF Secreted by Activated Kupffer Cells Induces Apoptosis of Plasmodium-Infected Hepatocytes.

PubMed

Gonçalves, Lígia Antunes; Rodo, Joana; Rodrigues-Duarte, Lurdes; de Moraes, Luciana Vieira; Penha-Gonçalves, Carlos

2017-01-01

Malaria liver stage infection is an obligatory parasite development step and represents a population bottleneck in Plasmodium infections, providing an advantageous target for blocking parasite cycle progression. Parasite development inside hepatocytes implies a gross cellular insult evoking innate host responses to counteract intra-hepatocytic infection. Using primary hepatocyte cultures, we investigated the role of Kupffer cell-derived hepatocyte growth factor (HGF) in malaria liver stage infection. We found that Kupffer cells from Plasmodium -infected livers produced high levels of HGF, which trigger apoptosis of infected hepatocytes through a mitochondrial-independent apoptosis pathway. HGF action in infected hepatocyte primary cultures results in a potent reduction of parasite yield by specifically sensitizing hepatocytes carrying established parasite exo-erythrocytic forms to undergo apoptosis. This apoptosis mechanism is distinct from cell death that is spontaneously induced in infected cultures and is governed by Fas signaling modulation through a mitochondrial-dependent apoptosis pathway. This work indicates that HGF and Fas signaling pathways are part of an orchestrated host apoptosis response that occurs during malaria liver stage infection, decreasing the success of infection of individual hepatocytes. Our results raise the hypothesis that paracrine signals derived from Kupffer cell activation are implicated in directing death of hepatocytes infected with the malaria parasite.

[Interleukin-37 induces apoptosis and autophagy of SMMC-7721 cells by inhibiting phosphorylation of mTOR].

PubMed

Li, Tingting; Zhu, Di; Mou, Tong; Guo, Zhen; Pu, Junliang; Wu, Zhongjun

2017-04-01

Objective To investigate the underlying mechanism by which interleukin-37 (IL-37) induces the apoptosis and autophagy in SMMC-7721 cells. Methods SMMC-7721 cells were incubated in vitro and divided into two groups, IL-37 treated group and control group. The cells were treated with (50, 100, 200) ng/mL of recombinant human interleukin-37 (rhIL-37). CCK-8 assay was used to detect the cell proliferation of SMMC-7721 cells. Cell apoptosis was measured by flow cytometry. Western blot analysis was performed to examine the expressions of apoptosis-related proteins, Bax, Bcl-2, and autophagy related proteins, microtubule-associated proteins 1 light chain 3 (LC3), beclin 1 and mammalian target of rapamycin (mTOR). Transmission electron microscopy (TEM) was used to observe the ultrastructures of autophagosomes. Results The rhIL-37 inhibited the proliferation of hepatocellular carcinoma SMMC-7721 cells. It induced the apoptosis and autophagy in SMMC-7721 cells. In the IL-37 treated group, the levels of Bax, LC3 and beclin 1 increased but Bcl-2 decreased. The phosphorylation of mTOR was inhibited in the IL-37 treated group. Autophagosome was obvious in the IL-37 treated group. Conclusion IL-37 induces the apoptosis and autophagy in SMMC-7721 cells, which may be related to the phosphorylation of mTOR.

6-Gingerol induces apoptosis through lysosomal-mitochondrial axis in human hepatoma G2 cells.

PubMed

Yang, Guang; Wang, Shaopeng; Zhong, Laifu; Dong, Xu; Zhang, Wenli; Jiang, Liping; Geng, Chengyan; Sun, Xiance; Liu, Xiaofang; Chen, Min; Ma, Yufang

2012-11-01

6-Gingerol, a major phenolic compound derived from ginger, has been known to possess anticarcinogenic activities. However, the mechanisms are not well understood. In our previous study, it was demonstrated that lysosome and mitochondria may be the primary targets for 6-gingerol in HepG2 cells. Therefore, the aim was to evaluate lysosome-mitochondria cross-signaling in 6-gingerol-induced apoptosis. Apoptosis was detected by Hoechst 33342 and TUNEL assay after 24 h treatment, and the destabilization of lysosome and mitochondria were early upstream initiating events. This study showed that cathepsin D played a crucial role in the process of apoptosis. The release of cathepsin D to the cytosol appeared to be an early event that preceded the release of cytochrome c from mitochondria. Moreover, inhibition of cathepsin D activity resulted in suppressed release of cytochrome c. To further determine the involvement of oxidative stress in 6-gingerol-induced apoptosis, the intracellular generation of reactive oxygen species (ROS) and reduced glutathione (GSH) were examined. Taken together, these results suggest that cathepsin D may be a positive mediator of 6-gingerol induced apoptosis in HepG2 cells, acting upstream of cytochrome c release, and the apoptosis may be associated with oxidative stress. Copyright © 2012 John Wiley & Sons, Ltd.

Albumin-induced apoptosis of tubular cells is modulated by BASP1

PubMed Central

Sanchez-Niño, M D; Fernandez-Fernandez, B; Perez-Gomez, M V; Poveda, J; Sanz, A B; Cannata-Ortiz, P; Ruiz-Ortega, M; Egido, J; Selgas, R; Ortiz, A

2015-01-01

Albuminuria promotes tubular injury and cell death, and is associated with faster progression of chronic kidney disease (CKD) to end-stage renal disease. However, the molecular mechanisms regulating tubular cell death in response to albuminuria are not fully understood. Brain abundant signal protein 1 (BASP1) was recently shown to mediate glucose-induced apoptosis in tubular cells. We have studied the role of BASP1 in albumin-induced tubular cell death. BASP1 expression was studied in experimental puromycin aminonucleoside-induced nephrotic syndrome in rats and in human nephrotic syndrome. The role of BASP1 in albumin-induced apoptosis was studied in cultured human HK2 proximal tubular epithelial cells. Puromycin aminonucleoside induced proteinuria and increased total kidney BASP1 mRNA and protein expression. Immunohistochemistry localized the increased BASP1 to tubular cells. BASP1 expression colocalized with deoxynucleotidyl-transferase-mediated dUTP nick-end labeling staining for apoptotic cells. Increased tubular BASP1 expression was observed in human proteinuric nephropathy by immunohistochemistry, providing evidence for potential clinical relevance. In cultured tubular cells, albumin induced apoptosis and increased BASP1 mRNA and protein expression at 6–48 h. Confocal microscopy localized the increased BASP1 expression in albumin-treated cells mainly to the perinuclear area. A peripheral location near the cell membrane was more conspicuous in albumin-treated apoptotic cells, where it colocalized with actin. Inhibition of BASP1 expression by a BASP1 siRNA protected from albumin-induced apoptosis. In conclusion, albumin-induced apoptosis in tubular cells is BASP1-dependent. This information may be used to design novel therapeutic approaches to slow CKD progression based on protection of tubular cells from the adverse consequences of albuminuria. PMID:25675304

Ketamine-induced apoptosis in cultured rat cortical neurons

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

Takadera, Tsuneo; Ishida, Akira; Ohyashiki, Takao

2006-01-15

Recent data suggest that anesthetic drugs cause neurodegeneration during development. Ketamine is frequently used in infants and toddlers for elective surgeries. The purpose of this study is to determine whether glycogen synthase kinase-3 (GSK-3) is involved in ketamine-induced apoptosis. Ketamine increased apoptotic cell death with morphological changes which were characterized by cell shrinkage, nuclear condensation or fragmentation. In addition, insulin growth factor-1 completely blocked the ketamine-induced apoptotic cell death. Ketamine decreased Akt phosphorylation. GSK-3 is known as a downstream target of Akt. The selective inhibitors of GSK-3 prevented the ketamine-induced apoptosis. Moreover, caspase-3 activation was accompanied by the ketamine-induced cellmore » death and inhibited by the GSK-3 inhibitors. These results suggest that activation of GSK-3 is involved in ketamine-induced apoptosis in rat cortical neurons.« less

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

Clinostat rotation induces apoptosis in luteal cells of the pregnant rat

NASA Technical Reports Server (NTRS)

Yang, Hyunwon; Bhat, Ganapathy K.; Sridaran, Rajagopala

2002-01-01

Recent studies have shown that microgravity induces changes at the cellular level, including apoptosis. However, it is unknown whether microgravity affects luteal cell function. This study was performed to assess whether microgravity conditions generated by clinostat rotation induce apoptosis and affect steroidogenesis by luteal cells. Luteal cells isolated from the corpora lutea of Day 8 pregnant rats were placed in equal numbers in slide flasks (chamber slides). One slide flask was placed in the clinostat and the other served as a stationary control. At 48 h in the clinostat, whereas the levels of progesterone and total cellular protein decreased, the number of shrunken cells increased. To determine whether apoptosis occurred in shrunken cells, Comet and TUNEL assays were performed. At 48 h, the percentage of apoptotic cells in the clinostat increased compared with that in the control. To investigate how the microgravity conditions induce apoptosis, the active mitochondria in luteal cells were detected with JC-1 dye. Cells in the control consisted of many active mitochondria, which were evenly distributed throughout the cell. In contrast, cells in the clinostat displayed fewer active mitochondria, which were distributed either to the outer edge of the cell or around the nucleus. These results suggest that mitochondrial dysfunction induced by clinostat rotation could lead to apoptosis in luteal cells and suppression of progesterone production.

The role of cPLA2 in Methylglyoxal-induced cell apoptosis of HUVECs

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

Yuan, Jie; Zhu, Chao; Hong, Yali

2017-05-15

Methylglyoxal (MGO), a highly reactive dicarbonyl compound, is mainly formed as a byproduct of glycolysis. Elevated MGO level is known to induce apoptosis of vascular endothelial cells, which is implicated with progression of atherosclerosis and diabetic complications. However, the underlying mechanisms have not been exhaustively investigated yet. Here, we further characterized the mechanisms how MGO induced apoptosis in human umbilical vein endothelial cells (HUVECs). Our data revealed that cytosolic phospholipase A2 (cPLA2) played an important role in MGO-induced cell apoptosis. It was found that MGO could increase both the activity and expression of cPLA2. Inhibition of cPLA2 by Pyrrophenone (PYR)more » or siRNA significantly attenuated the MGO-induced apoptosis. Additionally, MGO time-dependently decreased the phosphorylation of nuclear factor κB (NF-κB). Pretreatment of the cells with NF-κB inhibitor, BAY11-7082, further increased MGO-induced apoptosis of HUVECs, indicating that NF-κB played a survival role in this MGO-induced apoptosis. Furthermore, in the presence of si-cPLA2 or PYR, MGO no longer decreased NF-κB phosphorylation. Beyond that, the antioxidant N-acetyl cysteine (NAC) could reverse the changes of both cPLA2 and NF-κB caused by MGO. p38, the upstream of cPLA2, was also significantly phosphorylated by MGO. However, p38 inhibitor failed to reverse the apoptosis induced by MGO. This study gives an important insight into the downstream signaling mechanisms of MGO, cPLA2-NF-κB, in endothelial apoptosis. - Highlights: • cPLA2 participated in MGO-induced HUVECs apoptosis. • Inhibition of NF-κB was involved in MGO-cPLA2-mediated cell apoptosis. • Antioxidant NAC attenuated MGO-induced cPLA2 activation and cell apoptosis.« less

Overexpression of microRNA-125b inhibits human acute myeloid leukemia cells invasion, proliferation and promotes cells apoptosis by targeting NF-κB signaling pathway

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

Wang, Yan; Tang, Ping; Chen, Yanli

microRNA-125b has been reported to play an novel biological function in the progression and development of several kinds of leukemia. However, the detail role of miR-125b in acute myeloid leukemia (AML) is remains largely unknown. The present study aimed to investigate the biological role of miR-125b in AML and the potential molecular mechanism involved in this process. Our results showed that overexpression of miR-125b suppressed AML cells proliferation, invasion and promotes cells apoptosis in a dose-dependent manner, while the miR-NC did not show the same effect. In addition, miR-125b induced AML cells G2/M cell cycle arrest in vitro. Overexpression of miR-125bmore » resulted in a significant decrease of the expression of p-IκB-α and inhibition of IκB-α degradation, and the nuclear translocation of NF-κB subunit p65 was abrogated by miR-125b simutaneously. To further verify that miR-125b targeted NF-κB signaling pathway, the NF-κB-regulated downstream genes that were associated with cell cycle arrest and apoptosis was also determined. The results showed that, miR-125b also affect NF-κB-regulated genes expression involved in cell cycle arrest and apoptosis. In conclusion, the present work certificates that miR-125b can significantly inhibit human AML cells invasion, proliferation and promotes cells apoptosis by targeting the NF-κB signaling pathway, and thus it can be viewed as an promising therapeutic target for AML. - Highlights: • Overexpression of miR-125b suppressed AML cells proliferation, invasion and promotes cells apoptosis. • miR-125b induced AML cells G2/M cell cycle arrest in vitro. • miR-125b suppressed AML cells tumorigenicity and promoted cells apoptosis by targeting NF-κB pathway.« less

JS-K promotes apoptosis by inducing ROS production in human prostate cancer cells.

PubMed

Qiu, Mingning; Chen, Lieqian; Tan, Guobin; Ke, Longzhi; Zhang, Sai; Chen, Hege; Liu, Jianjun

2017-03-01

Reactive oxygen species (ROS) are chemical species that alter redox status, and are responsible for inducing carcinogenesis. The purpose of the present study was to assess the effects of the glutathione S transferase-activated nitric oxide donor prodrug, JS-K, on ROS accumulation and on proliferation and apoptosis in human prostate cancer cells. Cell proliferation and apoptosis, ROS accumulation and the activation of the mitochondrial signaling pathway were measured. The results demonstrated that JS-K may inhibit prostate cancer cell growth in a dose- and time-dependent manner, and induce ROS accumulation and apoptosis in a dose-dependent manner. With increasing concentrations of JS-K, expression of pro-apoptotic proteins increased, but Bcl-2 expression decreased. Additionally, the antioxidant N-acetylcysteine reversed JS-K-induced cell apoptosis; conversely, the pro-oxidant glutathione disulfide exacerbated JS-K-induced apoptosis. In conclusion, the data suggest that JS-K induces prostate cancer cell apoptosis by increasing ROS levels.

JS-K promotes apoptosis by inducing ROS production in human prostate cancer cells

PubMed Central

Qiu, Mingning; Chen, Lieqian; Tan, Guobin; Ke, Longzhi; Zhang, Sai; Chen, Hege; Liu, Jianjun

2017-01-01

Reactive oxygen species (ROS) are chemical species that alter redox status, and are responsible for inducing carcinogenesis. The purpose of the present study was to assess the effects of the glutathione S transferase-activated nitric oxide donor prodrug, JS-K, on ROS accumulation and on proliferation and apoptosis in human prostate cancer cells. Cell proliferation and apoptosis, ROS accumulation and the activation of the mitochondrial signaling pathway were measured. The results demonstrated that JS-K may inhibit prostate cancer cell growth in a dose- and time-dependent manner, and induce ROS accumulation and apoptosis in a dose-dependent manner. With increasing concentrations of JS-K, expression of pro-apoptotic proteins increased, but Bcl-2 expression decreased. Additionally, the antioxidant N-acetylcysteine reversed JS-K-induced cell apoptosis; conversely, the pro-oxidant glutathione disulfide exacerbated JS-K-induced apoptosis. In conclusion, the data suggest that JS-K induces prostate cancer cell apoptosis by increasing ROS levels. PMID:28454225

Apoptosis-inducing factor (Aif1) mediates anacardic acid-induced apoptosis in Saccharomyces cerevisiae.

PubMed

Muzaffar, Suhail; Chattoo, Bharat B

2017-03-01

Anacardic acid is a medicinal phytochemical that inhibits proliferation of fungal as well as several types of cancer cells. It induces apoptotic cell death in various cell types, but very little is known about the mechanism involved in the process. Here, we used budding yeast Saccharomyces cerevisiae as a model to study the involvement of some key elements of apoptosis in the anacardic acid-induced cell death. Plasma membrane constriction, chromatin condensation, DNA degradation, and externalization of phosphatidylserine (PS) indicated that anacardic acid induces apoptotic cell death in S. cerevisiae. However, the exogenous addition of broad-spectrum caspase inhibitor Z-VAD-FMK or deletion of the yeast caspase Yca1 showed that the anacardic acid-induced cell death is caspase independent. Apoptosis-inducing factor (AIF1) deletion mutant was resistant to the anacardic acid-induced cell death, suggesting a key role of Aif1. Overexpression of Aif1 made cells highly susceptible to anacardic acid, further confirming that Aif1 mediates anacardic acid-induced apoptosis. Interestingly, instead of the increase in the intracellular reactive oxygen species (ROS) normally observed during apoptosis, anacardic acid caused a decrease in the intracellular ROS levels. Quantitative real-time PCR analysis showed downregulation of the BIR1 survivin mRNA expression during the anacardic acid-induced apoptosis.

Inhibition of NEDD4 inhibits cell growth and invasion and induces cell apoptosis in bladder cancer cells.

PubMed

Wen, Wu; Li, Jingying; Wang, Longwang; Xing, Yifei; Li, Xuechao; Ruan, Hailong; Xi, Xiaoqing; Xiong, Jianhua; Kuang, Renrui

2017-08-18

The neural precursor cell expressed developmentally downregulated protein 4 (NEDD4) plays a pivotal oncogenic role in various types of human cancers. However, the function of NEDD4 in bladder cancer has not been fully investigated. In the present study, we aim to explore whether NEDD4 governs cell proliferation, apoptosis, migration, and invasion in bladder cancer cells. Our results showed that downregulation of NEDD4 suppressed cell proliferation in bladder cancer cells. Moreover, we found that inhibition of NEDD4 significantly induced cell apoptosis. Furthermore, downregulation of NEDD4 retarded cell migration and invasion. Notably, overexpression of NEDD4 enhanced cell growth and inhibited apoptosis. Consistently, upregulation of NEDD4 promoted cell migration and invasion in bladder cancer cells. Mechanically, our Western blotting results revealed that downregulation of NEDD4 activated PTEN and inhibited Notch-1 expression, whereas upregulation of NEDD4 reduced PTEN level and increased Notch-1 level in bladder cancer cells. Our findings indicated that NEDD4 exerts its oncogenic function partly due to regulation of PTEN and Notch-1 in bladder cancer cells. These results further revealed that targeting NEDD4 could be a useful approach for the treatment of bladder cancer.

Physcion induces mitochondria-driven apoptosis in colorectal cancer cells via downregulating EMMPRIN.

PubMed

Chen, Xuehong; Gao, Hui; Han, Yantao; Ye, Junli; Xie, Jing; Wang, Chunbo

2015-10-05

Physcion, an anthraquinone derivative widely isolated and characterized from both terrestrial and marine sources, has anti-tumor effects on a variety of carcinoma cells, mainly through inhibition of cell proliferation, apoptosis induction and cell cycle arrest. However, little is known about the mechanisms underlying its role in tumor progression. In the present study, we investigated the molecular mechanisms involved in physcion-induced apoptosis in human colorectal cancer (CRC) lines HCT116. Our results showed that physcion inhibited tumor cell viability in a dose- and time-dependent manner, and induced cell apoptosis via intrinsic mitochondrial pathway. Our results also revealed that physcion treatment significantly inhibited extracelluar matrix metalloproteinase inducer (EMMPRIN) expression in HCT116 cells in a dose-dependent manner and overexpression of EMMPRIN protein markedly reduced physcion-induced cell apoptosis. Furthermore, our results strongly indicated the modulating effect of physcion on EMMPRIN is correlated with AMP-activated protein kinase (AMPK)/Hypoxia-inducible factor 1α (HIF-1α) signaling pathway. Our data provide the first experimental evidence that physcion induces mitochondrial apoptosis in CRC cells by downregulating of EMMPRIN via AMPK/HIF-1α signaling pathway and suggest a new mechanism to explain its anti-tumor effects. Copyright © 2015 Elsevier B.V. All rights reserved.

Bone marrow stromal-B cell interactions in polycyclic aromatic hydrocarbon-induced pro/pre-B cell apoptosis.

PubMed

Allan, Lenka L; Mann, Koren K; Matulka, Raymond A; Ryu, Heui-Young; Schlezinger, Jennifer J; Sherr, David H

2003-12-01

Environmental polycyclic aromatic hydrocarbons (PAH) and related halogenated hydrocarbons are immunotoxic in a variety of systems. In a model system of B lymphopoiesis, PAH exposure rapidly induces apoptosis in CD43- pre-B and CD43+ pro/pre-B cells. Apoptosis induction by 7,12-dimethylbenzo[a]anthracene (DMBA) is dependent upon AhR+ bone marrow stromal cells and likely involves DMBA metabolism within the stromal cell. However, it is not known if PAH-treated stromal cells release free metabolites or soluble factors that may directly induce B cell death or if the effector death signal is delivered by stromal cell-B cell contact. Here, we demonstrate that supernatants from DMBA-treated bone marrow stromal cells contain an activity capable of inducing apoptosis in pro/pre-B cells cocultured with stromal cells. This activity (1) is not produced when stromal cells are cotreated with DMBA and alpha-naphthoflavone (alpha-NF), an aryl hydrocarbon receptor (AhR) and cytochrome P-450 inhibitor, (2) is > or = 50 kDa, (3) is trypsin and heat sensitive, and (4) is dependent on AhR+ stromal cells, which in turn deliver the effector death signal to pro/pre-B cells. The results (1) argue against a role for a soluble, stromal cell-derived cytokine as the effector of PAH-induced pro/pre-B cell death, (2) exclude the possibility of a free metabolite acting directly on AhR- pro/pre-B cell targets, and (3) suggest the elaboration by stromal cells of a relatively stable, DMBA metabolite-protein complex capable of acting on other stromal cells at some distance. Collectively, these studies suggest that, while stromal cell products, e.g., metabolite-protein complexes, may affect the function of distant stromal cells, the effector death signal delivered by stromal cells to bone marrow B cells is mediated by cell-cell contact.

6-Shogaol induces cell cycle arrest and apoptosis in human hepatoma cells through pleiotropic mechanisms.

PubMed

Wu, Jung-Ju; Omar, Hany A; Lee, Ying-Ray; Teng, Yen-Ni; Chen, Pin-Shern; Chen, Yu-Chung; Huang, Hsiao-Shan; Lee, Kuan-Han; Hung, Jui-Hsiang

2015-09-05

Shogaols are a group of the active constituents of ginger that have been identified to have various biological activities. The aim of the current study was to investigate the antitumor activity of 6-shogaol in hepatocellular carcinoma (HCC) and the possible involvement of reactive oxygen species as a putative mechanism of action. HCC cell lines, HepG2 and Huh-7, were used to study the in vitro anti-cancer activity of 6-shogaol via the application of various molecular biology techniques. Results showed that 6-shogaol effectively inhibited the cell viability, caused cell cycle arrest at G2/M phase and induced apoptosis in HCC cells as indicated by MTT assay, DAPI nuclear staining, annexin V assay, cell cycle analysis, and activation of caspase-3. Western blot analysis revealed the ability of 6-shogaol to target cancer survival signaling pathways mediated by mitogen-activated protein kinase (MAPK), 5' AMP-activated protein kinase (AMPK) and Akt. In addition, 6-Shogaol induced alteration of cyclin proteins expression and caused cleavage of protein kinase C delta. Furthermore, 6-Shogaol was able to induce the production of reactive oxygen species and endoplasmic reticulum (ER) stress-associated proteins and the consequent activation of autophagy in HepG2 cells. Taken together, the current study highlights evidences that 6-shogaol induces apoptosis, modulates cyclins expression and targets cancer survival signaling pathways in HCC cell lines, at least in part, via the production of reactive oxygen species. These findings support 6-shogaol's clinical promise as a potential candidate for HCC therapy. Copyright © 2015 Elsevier B.V. All rights reserved.

Lentiviral Delivery of HIV-1 Vpr Protein Induces Apoptosis in Transformed Cells

NASA Astrophysics Data System (ADS)

Stewart, Sheila A.; Poon, Betty; Jowett, Jeremy B. M.; Xie, Yiming; Chen, Irvin S. Y.

1999-10-01

Most current anticancer therapies act by inducing tumor cell stasis followed by apoptosis. HIV-1 Vpr effectively induces apoptosis of T cells after arrest of cells at a G2/M checkpoint. Here, we investigated whether this property of Vpr could be exploited for use as a potential anticancer agent. As a potentially safer alternative to transfer of genes encoding Vpr, we developed a method to efficiently introduce Vpr protein directly into cells. Vpr packaged into HIV-1 virions lacking a genome induced efficient cell cycle arrest and apoptosis. Introduction of Vpr into tumor cell lines of various tissue origin, including those bearing predisposing mutations in p53, XPA, and hMLH1, induced cell cycle arrest and apoptosis with high efficiency. Significantly, apoptosis mediated by virion-associated Vpr was more effective on rapidly dividing cells compared with slow-growing cells, thus, in concept, providing a potential differential effect between some types of tumor cells and surrounding normal cells. This model system provides a rationale and proof of concept for the development of potential cancer therapeutic agents based on the growth-arresting and apoptotic properties of Vpr.

The Efficacy of Dandelion Root Extract in Inducing Apoptosis in Drug-Resistant Human Melanoma Cells

PubMed Central

Chatterjee, S. J.; Ovadje, P.; Mousa, M.; Hamm, C.; Pandey, S.

2011-01-01

Notoriously chemoresistant melanoma has become the most prevalent form of cancer for the 25–29 North American age demographic. Standard treatment after early detection involves surgical excision (recurrence is possible), and metastatic melanoma is refractory to immuno-, radio-, and most harmful chemotherapies. Various natural compounds have shown efficacy in killing different cancers, albeit not always specifically. In this study, we show that dandelion root extract (DRE) specifically and effectively induces apoptosis in human melanoma cells without inducing toxicity in noncancerous cells. Characteristic apoptotic morphology of nuclear condensation and phosphatidylserine flipping to the outer leaflet of the plasma membrane of A375 human melanoma cells was observed within 48 hours. DRE-induced apoptosis activates caspase-8 in A375 cells early on, demonstrating employment of an extrinsic apoptotic pathway to kill A375 cells. Reactive Oxygen Species (ROS) generated from DRE-treated isolated mitochondria indicates that natural compounds in DRE can also directly target mitochondria. Interestingly, the relatively resistant G361 human melanoma cell line responded to DRE when combined with the metabolism interfering antitype II diabetic drug metformin. Therefore, treatment with this common, yet potent extract of natural compounds has proven novel in specifically inducing apoptosis in chemoresistant melanoma, without toxicity to healthy cells. PMID:21234313

Isothiocyanates from Broccolini seeds induce apoptosis in human colon cancer cells: proteomic and bioinformatic analyses.

PubMed

Yang, Yanjing; Yan, Huidan; Li, Yuqin; Yang, Shang-Tian; Zhang, Xuewu

2011-05-01

Isothiocyanates (ITCs) have been shown to possess antitumor activity in colon cancer, however, the detailed mechanism is still unclear. The objective of this study was to investigate apoptosis-inducing activity of ITCs from Broccolini seeds and proteomic changes in SW480 cells, and to identify the molecular pathways responsible for the anticancer action of ITCs. We found that ITCs induces SW480 cells apoptosis in a dose-dependent manner by using MTT assay, phase contrast microscope and flow cytometry, and the IC50 was calculated to be 77.72 microg/ml, superior to the chemotherapeutical drug 5-flurouracil. Subsequently, 15 altered proteins in ITCs treated SW480 cells were identified. Further bioinformatics analysis predicted the potential pathways for ITCs to induce apoptosis of SW480 cells. In conclusion, this is the first report to investigate anticancer activity of ITCs from Broccolini seeds and its mechanism of action by proteomics analysis. Our observations provide potential therapeutic targets for colon cancer inhibitor intervention and implicate the development of novel anti-cancer therapeutic strategies.

Ras/ERK signaling pathway is involved in curcumin-induced cell cycle arrest and apoptosis in human gastric carcinoma AGS cells.

PubMed

Cao, Ai-Li; Tang, Qing-Feng; Zhou, Wen-Chao; Qiu, Yan-Yan; Hu, Song-Jiao; Yin, Pei-Hao

2015-01-01

Curcumin, the biologically active compound from the rhizome of Curcuma longa, could inhibit cell growth and induce apoptosis in gastric carcinoma. However, the underlying mechanism of curcumin on gastric carcinoma cells still needs further investigation. In this study, morphological observation indicated that curcumin inhibited the proliferation of AGS cells in a dose-dependent manner. According to the flow cytometric analysis, curcumin treatment resulted in G2/M arrest in AGS cells, accompanied with an increased expression of cyclin B1 and a decreased expression of cyclin D1. In addition, DNA ladders were observed by gel electrophoresis. Meanwhile, the activities of caspase-3, -8, and -9 were also enhanced in curcumin-treated AGS cells. Nevertheless, the increased activities could be inhibited by benzyloxycarbonyl-Val-Ala-Asp (OME)-fluoromethylketone (z-VAD-fmk), which suggested that the apoptosis was caspase-dependent. Furthermore, downregulation of rat sarcoma (Ras) and upregulation of extracellular-signal-regulated kinase (ERK) were also observed in AGS cells treated with curcumin by Western blot. U0126, an ERK inhibitor, blocked curcumin-induced apoptosis. The results suggested that curcumin inhibited the growth of the AGS cells and induced apoptosis through the activation of Ras/ERK signaling pathway and downstream caspase cascade, and curcumin might be a potential target for the treatment of gastric carcinoma.

Autophagy regulates chlorpyrifos-induced apoptosis in SH-SY5Y cells.

PubMed

Park, Jae Hyeon; Lee, Jeong Eun; Shin, In Chul; Koh, Hyun Chul

2013-04-01

Recent studies have shown that up-regulation of autophagy may be a tractable therapeutic intervention for clearing disease-causing proteins, including α-synuclein, ubiquitin, and other misfolded or aggregated proteins in pesticide-induced neurodegeneration. In a previous study, we reported that chlorpyrifos (CPF)-induced mitochondria-dependent apoptosis is mediated through reactive oxygen species in SH-SY5Y cells. In this study, we explored a novel pharmacotherapeutic approach to prevent CPF neurotoxicity involving the regulation of autophagy. We investigated the modulation of CPF-induced apoptosis according to autophagy regulation. We found that CPF induced apoptosis in SH-SY5Y cells, as demonstrated by the activation of caspase-3 and nuclear condensation. In addition, we observed that cells treated with CPF underwent autophagic cell death by monitoring the expression of LC3-II and p62. Pretreatment with the autophagy inducer rapamycin significantly enhanced the cell viability of CPF-exposed cells, and the enhancement of cell viability was partially due to alleviation of CPF-induced apoptosis via a decrease in levels of cleaved caspase-3. Specifically, rapamycin pretreatment decreased Bax and increased Bcl-2 expression in mitochondria. In addition, rapamycin significantly decreased cytochrome c release in from mitochondria into the cytosol. However, pretreatment of cells with the autophagy inhibitor, 3-methyladenine (3MA), remarkably increased CPF toxicity in these cells; this with correlated with increased expression of Bax and decreased expression of Bcl-2 in mitochondria. Our results suggest that CPF-induced cytotoxicity is modified by autophagy regulation and that rapamycin protects against CPF-induced apoptosis by enhancing autophagy. Pharmacologic induction of autophagy by rapamycin may be a useful treatment strategy in neurodegenerative disorders. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Prostaglandin E2 blocks menadione-induced apoptosis through the Ras/Raf/Erk signaling pathway in promonocytic leukemia cell lines.

PubMed

Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

2012-04-01

Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E(2) (PGE(2)) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE(2) as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE(2) markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP(2) receptor antagonist AH6809 abrogated the inhibitory effect of PGE(2), suggesting the role of the EP(2)/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE(2). The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE(2) on menadione-treated cells. Furthermore, PGE(2) activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE(2) via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics.

Prostaglandin E2 Blocks Menadione-Induced Apoptosis through the Ras/Raf/Erk Signaling Pathway in Promonocytic Leukemia Cell Lines

PubMed Central

Yeo, Hyun-Seok; Shehzad, Adeeb; Lee, Young Sup

2012-01-01

Altered oxidative stress has long been observed in cancer cells, and this biochemical property of cancer cells represents a specific vulnerability that can be exploited for therapeutic benefit. The major role of an elevated oxidative stress for the efficacy of molecular targeted drugs is under investigation. Menadione is considered an attractive model for the study of oxidative stress, which can induce apoptosis in human leukemia HL-60 cell lines. Prostaglandin E2 (PGE2) via its receptors not only promotes cell survival but also reverses apoptosis and promotes cancer progression. Here, we present evidence for the biological role of PGE2 as a protective agent of oxidative stress-induced apoptosis in monocytic cells. Pretreatment of HL-60 cells with PGE2 markedly ameliorated the menadione-induced apoptosis and inhibited the degradation of PARP and lamin B. The EP2 receptor antagonist AH6809 abrogated the inhibitory effect of PGE2, suggesting the role of the EP2/cAMP system. The PKA inhibitor H89 also reversed apoptosis and decreased the PKA activity that was elevated 10-fold by PGE2. The treatment of HL-60 cells with NAC or zinc chloride showed a similar protective effect as with PGE2 on menadione-treated cells. Furthermore, PGE2 activated the Ras/Raf/MEK pathway, which in turn initiated ERK activation, and ultimately protected menadione-induced apoptosis. These results imply that PGE2 via cell survival pathways may protect oxidative stress-induced apoptosis in monocytic cells. This study warrants further pre-clinical investigation as well as application towards leukemia clinics. PMID:22450688

Resistance to etoposide-induced apoptosis in a Burkitt's lymphoma cell line.

PubMed

Zhao, E G; Song, Q; Cross, S; Misko, I; Lees-Miller, S P; Lavin, M F

1998-08-31

Burkitt's lymphoma cells that vary in their phenotypic characteristics show significantly different degrees of susceptibility to radiation-induced apoptosis. Propensity to undergo apoptosis is reflected in the degradation of substrates such as DNA-dependent protein kinase but the status of bcl-2, c-myc and p53 has been uninformative. In this study, we have focused on 2 Epstein-Barr virus (EBV)-associated Burkitt's cell lines, one (WW2) susceptible and the other (BL29) resistant to etoposide-induced apoptosis. Differences in expression of BHRF1, an EBV gene that is homologous to the Bcl-2 proto-oncogene and known to inhibit apoptosis, or changes in apoptosis inhibitory proteins (IAPs), did not appear to account for the difference in susceptibility in the 2 cell lines. Cytoplasmic extracts from etoposide-treated WW2 cells caused apoptotic changes in nuclei isolated from either BL29 or WW2 cells, whereas extracts from BL29 cells failed to do so. In addition, extracts from etoposide-treated WW2 cells degraded the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), an important indicator of apoptosis, but this protein was resistant to degradation by BL29 extracts. It appears likely that caspase 3 (CPP32) is involved in this degradation since it was activated only in the apoptosis susceptible cells and the pattern of cleavage of DNA-PKcs was similar to that reported previously with recombinant caspase 3. As observed previously, addition of caspase 3 to nuclei failed to induce morphological changes indicative of apoptosis, but addition of caspase 3 to nuclei in the presence of extract from the resistant cells led to apoptotic changes. We conclude that resistance to apoptosis in BL29 cells is due to a failure of etoposide to activate upstream effectors of caspase activity.

Ruthenium complexes with phenylterpyridine derivatives target cell membrane and trigger death receptors-mediated apoptosis in cancer cells.

PubMed

Deng, Zhiqin; Gao, Pan; Yu, Lianling; Ma, Bin; You, Yuanyuan; Chan, Leung; Mei, Chaoming; Chen, Tianfeng

2017-06-01

Elucidation of the communication between metal complexes and cell membrane may provide useful information for rational design of metal-based anticancer drugs. Herein we synthesized a novel class of ruthenium (Ru) complexes containing phtpy derivatives (phtpy = phenylterpyridine), analyzed their structure-activity relationship and revealed their action mechanisms. The result showed that, the increase in the planarity of hydrophobic Ru complexes significantly enhanced their lipophilicity and cellular uptake. Meanwhile, the introduction of nitro group effectively improved their anticancer efficacy. Further mechanism studies revealed that, complex (2c), firstly accumulated on cell membrane and interacted with death receptors to activate extrinsic apoptosis signaling pathway. The complex was then transported into cell cytoplasm through transferrin receptor-mediated endocytosis. Most of the intracellular 2c accumulated in cell plasma, decreasing the level of cellular ROS, inducing the activation of caspase-9 and thus intensifying the apoptosis. At the same time, the residual 2c can translocate into cell nucleus to interact with DNA, induce DNA damage, activate p53 pathway and enhance apoptosis. Comparing with cisplatin, 2c possesses prolonged circulation time in blood, comparable antitumor ability and importantly, much lower toxicity in vivo. Taken together, this study uncovers the role of membrane receptors in the anticancer actions of Ru complexes, and provides fundamental information for rational design of membrane receptor targeting anticancer drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

RITA (Reactivating p53 and Inducing Tumor Apoptosis) is efficient against TP53abnormal myeloma cells independently of the p53 pathway.

PubMed

Surget, Sylvanie; Descamps, Géraldine; Brosseau, Carole; Normant, Vincent; Maïga, Sophie; Gomez-Bougie, Patricia; Gouy-Colin, Nadège; Godon, Catherine; Béné, Marie C; Moreau, Philippe; Le Gouill, Steven; Amiot, Martine; Pellat-Deceunynck, Catherine

2014-06-14

The aim of this study was to evaluate the efficacy of the p53-reactivating drugs RITA and nutlin3a in killing myeloma cells. A large cohort of myeloma cell lines (n = 32) and primary cells (n = 21) was used for this study. This cohort contained cell lines with various TP53 statuses and primary cells with various incidences of deletion of chromosome 17. Apoptosis was evaluated using flow cytometry with Apo2.7 staining of the cell lines or via the loss of the myeloma-specific marker CD138 in primary cells. Apoptosis was further confirmed by the appearance of a subG1 peak and the activation of caspases 3 and 9. Activation of the p53 pathway was monitored using immunoblotting via the expression of the p53 target genes p21, Noxa, Bax and DR5. The involvement of p53 was further studied in 4 different p53-silenced cell lines. Both drugs induced the apoptosis of myeloma cells. The apoptosis that was induced by RITA was not related to the TP53 status of the cell lines or the del17p status of the primary samples (p = 0.52 and p = 0.80, respectively), and RITA did not commonly increase the expression level of p53 or p53 targets (Noxa, p21, Bax or DR5) in sensitive cells. Moreover, silencing of p53 in two TP53(mutated) cell lines failed to inhibit apoptosis that was induced by RITA, which confirmed that RITA-induced apoptosis in myeloma cells was p53 independent. In contrast, apoptosis induced by nutlin3a was directly linked to the TP53 status of the cell lines and primary samples (p < 0.001 and p = 0.034, respectively) and nutlin3a increased the level of p53 and p53 targets in a p53-dependent manner. Finally, we showed that a nutlin3a-induced DR5 increase (≥ 1.2-fold increase) was a specific and sensitive marker (p < 0.001) for a weak incidence of 17p deletion within the samples (≤ 19%). These data show that RITA, in contrast to nutlin3a, effectively induced apoptosis in a subset of MM cells independently of p53. The findings and could be of interest for patients with a

RITA (Reactivating p53 and Inducing Tumor Apoptosis) is efficient against TP53abnormal myeloma cells independently of the p53 pathway

PubMed Central

2014-01-01

Background The aim of this study was to evaluate the efficacy of the p53-reactivating drugs RITA and nutlin3a in killing myeloma cells. Methods A large cohort of myeloma cell lines (n = 32) and primary cells (n = 21) was used for this study. This cohort contained cell lines with various TP53 statuses and primary cells with various incidences of deletion of chromosome 17. Apoptosis was evaluated using flow cytometry with Apo2.7 staining of the cell lines or via the loss of the myeloma-specific marker CD138 in primary cells. Apoptosis was further confirmed by the appearance of a subG1 peak and the activation of caspases 3 and 9. Activation of the p53 pathway was monitored using immunoblotting via the expression of the p53 target genes p21, Noxa, Bax and DR5. The involvement of p53 was further studied in 4 different p53-silenced cell lines. Results Both drugs induced the apoptosis of myeloma cells. The apoptosis that was induced by RITA was not related to the TP53 status of the cell lines or the del17p status of the primary samples (p = 0.52 and p = 0.80, respectively), and RITA did not commonly increase the expression level of p53 or p53 targets (Noxa, p21, Bax or DR5) in sensitive cells. Moreover, silencing of p53 in two TP53mutated cell lines failed to inhibit apoptosis that was induced by RITA, which confirmed that RITA-induced apoptosis in myeloma cells was p53 independent. In contrast, apoptosis induced by nutlin3a was directly linked to the TP53 status of the cell lines and primary samples (p < 0.001 and p = 0.034, respectively) and nutlin3a increased the level of p53 and p53 targets in a p53-dependent manner. Finally, we showed that a nutlin3a-induced DR5 increase (≥1.2-fold increase) was a specific and sensitive marker (p < 0.001) for a weak incidence of 17p deletion within the samples (≤19%). Conclusion These data show that RITA, in contrast to nutlin3a, effectively induced apoptosis in a subset of MM cells independently of p53. The findings and could be

Involvement of AMPK signaling cascade in capsaicin-induced apoptosis of HT-29 colon cancer cells.

PubMed

Kim, Young Min; Hwang, Jin-Taek; Kwak, Dong Wook; Lee, Yun Kyung; Park, Ock Jin

2007-01-01

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is activated during ATP-depleting metabolic states, such as hypoxia, heat shock, oxidative stress, and exercise. As a highly conserved heterotrimeric kinase that functions as a major metabolic switch to maintain energy homeostasis, AMPK has been shown to exert as an intrinsic regulator of mammalian cell cycle. Moreover, AMPK cascade has emerged as an important pathway implicated in cancer control. In this article, we have investigated the effects of capsaicin on apoptosis in relation to AMPK activation in colon cancer cell. Capsaicin-induced apoptosis was revealed by the presence of nucleobodies in the capsaicin-treated HT-29 colon cancer cells. Concomitantly, the activation of AMPK and the increased expression of the inactive form of acetyl-CoA carboxylase (ACC) were detected in capsaicin-treated colon cancer cells. We showed that both capsaicin and 5'-aminoimidazole-4-carboxamide-1-beta-D-ribonucleoside (AICAR), an AMPK activator possess the AMPK-activating capacity as well as apoptosis-inducing properties. Evidence of the association between AMPK activation and the increased apoptosis in HT-29 colon cancer cells by capsaicin treatment, and further findings of the correlation of the activated AMPK and the elevated apoptosis by cotreatment of AICAR and capsaicin support AMPK as an important component of apoptosis, as well as a possible target of cancer control.

Apoptotic cells can induce non-autonomous apoptosis through the TNF pathway

PubMed Central

Pérez-Garijo, Ainhoa; Fuchs, Yaron; Steller, Hermann

2013-01-01

Apoptotic cells can produce signals to instruct cells in their local environment, including ones that stimulate engulfment and proliferation. We identified a novel mode of communication by which apoptotic cells induce additional apoptosis in the same tissue. Strong induction of apoptosis in one compartment of the Drosophila wing disc causes apoptosis of cells in the other compartment, indicating that dying cells can release long-range death factors. We identified Eiger, the Drosophila tumor necrosis factor (TNF) homolog, as the signal responsible for apoptosis-induced apoptosis (AiA). Eiger is produced in apoptotic cells and, through activation of the c-Jun N-terminal kinase (JNK) pathway, is able to propagate the initial apoptotic stimulus. We also show that during coordinated cell death of hair follicle cells in mice, TNF-α is expressed in apoptotic cells and is required for normal cell death. AiA provides a mechanism to explain cohort behavior of dying cells that is seen both in normal development and under pathological conditions. DOI: http://dx.doi.org/10.7554/eLife.01004.001 PMID:24066226

Delayed Cell Cycle Progression and Apoptosis Induced by Hemicellulase-Treated Agaricus blazei

PubMed Central

Kasai, Hirotake

2007-01-01

We examined the effects of hemicellulase-treated Agaricus blazei (AB fraction H, ABH) on growth of several tumor cell lines. ABH inhibited the proliferation of some cell lines without cytotoxic effects. It markedly prolonged the S phase of the cell cycle. ABH also induced mitochondria-mediated apoptosis in different cell lines. However, it had no impact on the growth of other cell lines. ABH induced strong activation of p38 mitogen-activated protein kinase (MAPK) in the cells in which it evoked apoptosis. On the other hand, ABH showed only a weak p38 activation effect in those cell lines in which it delayed cell cycle progression with little induction of apoptosis. However, p38 MAPK-specific inhibitor inhibited both ABH-induced effects, and ABH also caused apoptosis in the latter cells under conditions of high p38 MAPK activity induced by combined treatment with TNF-α. These results indicate that the responsiveness of p38 MAPK to ABH, which differs between cell lines, determines subsequent cellular responses on cell growth. PMID:17342245

Expression of the p53 target CDIP correlates with sensitivity to TNFα-induced apoptosis in cancer cells.

PubMed

Brown-Endres, Lauren; Schoenfeld, David; Tian, Fang; Kim, Hyung-Gu; Namba, Takushi; Muñoz-Fontela, César; Mandinova, Anna; Aaronson, Stuart A; Lee, Sam W

2012-05-01

TNFα is a pleiotropic cytokine that signals for both survival and apoptotic cell fates. It is still unclear that the dual role of TNFα can be regulated in cancer cells. We previously described an apoptotic pathway involving p53→CDIP→TNFα that was activated in response to genotoxic stress. This pathway operated in the presence of JNK activation; therefore, we postulated that CDIP itself could sensitize cells to a TNFα apoptotic cell fate, survival, or death. We show that CDIP mediates sensitivity to TNFα-induced apoptosis and that cancer cells with endogenous CDIP expression are inherently sensitive to the growth-suppressive effects of TNFα in vitro and in vivo. Thus, CDIP expression correlates with sensitivity of cancer cells with TNFα, and CDIP seems to be a regulator of the p53-mediated death versus survival response of cells to TNFα. This CDIP-mediated sensitivity to TNFα-induced apoptosis favors pro- over antiapoptotic program in cancer cells, and CDIP may serve as a predictive biomarker for such sensitivity. ©2012 AACR

Bromelain-induced apoptosis in GI-101A breast cancer cells.

PubMed

Dhandayuthapani, Sivanesan; Perez, Honey Diaz; Paroulek, Alexandra; Chinnakkannu, Panneerselvam; Kandalam, Umadevi; Jaffe, Mark; Rathinavelu, Appu

2012-04-01

Bromelain is a proteolytic enzyme extracted from the stems and the immature fruits of pineapple that was found to be antitumorigenic in different in vitro models. Bromelain has been reported to promote apoptosis, particularly in breast cancer cells, with the up-regulation of c-Jun N-terminal kinase and p38 kinase. Our study was designed to determine if bromelain could induce apoptosis in GI-101A breast cancer cells. GI-101A cells were treated with increasing concentrations of bromelain for 24 hours. The effect of bromelain for inducing cell death via activation of the apoptosis mechanism in GI-101A cells was further determined by using caspase-9 and caspase-3 assays along with the M30-Apoptosense assay to measure cytokeratin 18 (CK18) levels in the cytoplasm of the cultured cancer cells. A dose-dependent increase in the activities of caspase-9 and caspase-3 coinciding with elevation of CK18 levels was found in bromelain-treated cells compared with control cells. Furthermore, the apoptosis induction by bromelain was confirmed by DNA fragmentation analysis and 4,6'-diamino-2-phenylindole dihydrochloride fluorescence staining of the nucleus. Our results indicate an increase in apoptosis-related cell death in breast cancer cells with increasing concentrations of bromelain.

Inhibition of calmodulin-dependent phosphodiesterase induces apoptosis in human leukemic cells.

PubMed Central

Jiang, X; Li, J; Paskind, M; Epstein, P M

1996-01-01

Cytosolic extracts from a human lymphoblastoid B-cell line, RPMI-8392, established from a patient with acute lymphocytic leukemia, contain two major forms of cyclic nucleotide phosphodiesterase (PDE): Ca2+-calmodulin dependent PDE (PDE1) and cAMP-specific PDE (PDE4). In contrast, normal quiescent human peripheral blood lymphocytes (HPBL) are devoid of PDE1 activity [Epstein, P. M., Moraski, S., Jr., and Hachisu, R. (1987) Biochem. J. 243, 533-539]. Using reverse transcription-polymerase chain reaction (RT-PCR), we show that the mRNA encoding the 63-kDa form of PDE1 (PDE1B1) is expressed in RPMI-8392 cells, but not in normal, resting HPBL. This mRNA is, however, induced in HPBL following mitogenic stimulation by phytohemagglutinin (PHA). Also using RT-PCR, the full open reading frame for human PDE1B1 cDNA was cloned from RPMI-8392 cells and it encodes a protein of 536 amino acids with 96% identity to bovine, rat, and mouse species. RT-PCR also identifies the presence of PDE1B1 in other human lymphoblastoid and leukemic cell lines of B- (RPMI-1788, Daudi) and T-(MOLT-4, NA, Jurkat) cell origin. Inhibition of PDE1 or PDE4 activity by selective inhibitors induced RPMI-8392 cells, as well as the other cell lines, to undergo apoptosis. Culture of RPMI-8392 cells with an 18-bp phosphorothioate antisense oligodeoxynucleotide, targeted against the translation initiation region of the RPMI-8392 mRNA, led to a specific reduction in the amount of PDE1B1 mRNA after 1 day, and its disappearance after 2 days, and induced apoptosis in these cells in a sequence specific manner. This suggests that PDEs, particularly PDE1B1, because its expression is selective, may be useful targets for inducing the death of leukemic cells. Images Fig. 1 Fig. 3 Fig. 5 Fig. 6 PMID:8855339

Interplay between autophagy and apoptosis in lead(II)-induced cytotoxicity of primary rat proximal tubular cells.

PubMed

Chu, Bing-Xin; Fan, Rui-Feng; Lin, Shu-Qian; Yang, Du-Bao; Wang, Zhen-Yong; Wang, Lin

2018-05-01

Autophagy and apoptosis are two different biological processes that determine cell fates. We previously reported that autophagy inhibition and apoptosis induction are involved in lead(II)-induced cytotoxicity in primary rat proximal tubular (rPT) cells, but the interplay between them remains to be elucidated. Firstly, data showed that lead(II)-induced elevation of LC3-II protein levels can be significantly modulated by 3-methyladenine or rapamycin; moreover, protein levels of Autophagy-related protein 5 (Atg5) and Beclin-1 were markedly up-regulated by lead(II) treatment, demonstrating that lead(II) could promote the autophagosomes formation in rPT cells. Next, we applied three pharmacological agents and genetic method targeting the early stage of autophagy to validate that enhancement of autophagosomes formation can inhibit lead(II)-induced apoptotic cell death in rPT cells. Simultaneously, lead(II) inhibited the autophagic degradation of rPT cells, while the addition of autophagic degradation inhibitor bafilomycin A1 aggravated lead(II)-induced apoptotic death in rPT cells. Collectively, this study provided us a good model to know about the dynamic process of lead(II)-induced autophagy in rPT cells, and the interplay between autophagy and apoptosis highlights a new sight into the mechanism of lead(II)-induced nephrotoxicity. Copyright © 2018. Published by Elsevier Inc.

Myostatin induces mitochondrial metabolic alteration and typical apoptosis in cancer cells

PubMed Central

Liu, Y; Cheng, H; Zhou, Y; Zhu, Y; Bian, R; Chen, Y; Li, C; Ma, Q; Zheng, Q; Zhang, Y; Jin, H; Wang, X; Chen, Q; Zhu, D

2013-01-01

Myostatin, a member of the transforming growth factor-β superfamily, regulates the glucose metabolism of muscle cells, while dysregulated myostatin activity is associated with a number of metabolic disorders, including muscle cachexia, obesity and type II diabetes. We observed that myostatin induced significant mitochondrial metabolic alterations and prolonged exposure of myostatin induced mitochondria-dependent apoptosis in cancer cells addicted to glycolysis. To address the underlying mechanism, we found that the protein levels of Hexokinase II (HKII) and voltage-dependent anion channel 1 (VDAC1), two key regulators of glucose metabolisms as well as metabolic stress-induced apoptosis, were negatively correlated. In particular, VDAC1 was dramatically upregulated in cells that are sensitive to myostatin treatment whereas HKII was downregulated and dissociated from mitochondria. Myostatin promoted the translocation of Bax from cytosol to mitochondria, and knockdown of VDAC1 inhibited myostatin-induced Bax translocation and apoptosis. These apoptotic changes can be partially rescued by repletion of ATP, or by ectopic expression of HKII, suggesting that perturbation of mitochondrial metabolism is causally linked with subsequent apoptosis. Our findings reveal novel function of myostatin in regulating mitochondrial metabolism and apoptosis in cancer cells. PMID:23412387

Nupr1/Chop signal axis is involved in mitochondrion-related endothelial cell apoptosis induced by methamphetamine

PubMed Central

Cai, D; Huang, E; Luo, B; Yang, Y; Zhang, F; Liu, C; Lin, Z; Xie, W-B; Wang, H

2016-01-01

Methamphetamine (METH) abuse has been a serious global public health problem for decades. Previous studies have shown that METH causes detrimental effects on the nervous and cardiovascular systems. METH-induced cardiovascular toxicity has been, in part, attributed to its destructive effect on vascular endothelial cells. However, the underlying mechanism of METH-caused endothelium disruption has not been investigated systematically. In this study, we identified a novel pathway involved in endothelial cell apoptosis induced by METH. We demonstrated that exposure to METH caused mitochondrial apoptosis in human umbilical vein endothelial cells and rat cardiac microvascular endothelial cells in vitro as well as in rat cardiac endothelial cells in vivo. We found that METH mediated endothelial cell apoptosis through Nupr1–Chop/P53–PUMA/Beclin1 signaling pathway. Specifically, METH exposure increased the expression of Nupr1, Chop, P53 and PUMA. Elevated p53 expression raised up PUMA expression, which initiated mitochondrial apoptosis by downregulating antiapoptotic Bcl-2, followed by upregulation of proapoptotic Bax, resulting in translocation of cytochrome c (cyto c), an apoptogenic factor, from the mitochondria to cytoplasm and activation of caspase-dependent pathways. Interestingly, increased Beclin1, upregulated by Chop, formed a ternary complex with Bcl-2, thereby decreasing the dissociative Bcl-2. As a result, the ratio of dissociative Bcl-2 to Bax was also significantly decreased, which led to translocation of cyto c and initiated more drastic apoptosis. These findings were supported by data showing METH-induced apoptosis was significantly inhibited by silencing Nupr1, Chop or P53, or by PUMA or Beclin1 knockdown. Based on the present data, a novel mechanistic model of METH-induced endothelial cell toxicity is proposed. Collectively, these results highlight that the Nupr1–Chop/P53–PUMA/Beclin1 pathway is essential for mitochondrion-related METH-induced

mir-200c Regulates Induction of Apoptosis through CD95 by Targeting FAP-1

PubMed Central

Schickel, Robert; Park, Sun-Mi; Murmann, Andrea E.; Peter, Marcus E.

2010-01-01

SUMMARY Tumor progression shares many characteristics with the process of epithelial-to-mesenchymal transition (EMT). Cells that have undergone an EMT are known to have an increased resistance to apoptosis. CD95/Fas is an apoptosis-inducing receptor expressed on many tissues and tumor cells. During tumor progression CD95 is frequently downregulated, and tumor cells lose apoptosis sensitivity. miR-200 microRNAs repress both the EMT-inducing ZEB1 and ZEB2 transcription factors. We now demonstrate that miR-200c sensitizes cells to apoptosis mediated by CD95. We have identified the apoptosis inhibitor FAP-1 as a target for miR-200c. FAP-1 was demonstrated to be responsible for the reduced sensitivity to CD95-mediated apoptosis in cells with inhibited miR-200. The identification of FAP-1 as a miR-200c target provides a molecular mechanism to explain both the downregulation of CD95 expression and the reduction in sensitivity of cells to CD95-mediated apoptosis that is observed in the context of reduced miR-200 expression during tumor progression. PMID:20620960

Osthole inhibits proliferation and induces apoptosis in human osteosarcoma cells.

PubMed

Ding, Yong; Lu, Xiongwei; Hu, Xiaopeng; Ma, Jie; Ding, Huan

2014-02-01

The purpose of this study was to investigate the effect of osthole on osteosarcoma cell proliferation and apoptosis. Cell counting Kit-8 assay was performed to establish the effects of osthole on osteosarcoma MG-63 cell proliferation. Annexin V-FITC/PI was performed to analyze the apoptotic rate of the cells. The inhibitory effects of osthole on the expression of BCL-2, BAX, and caspase-3 were detected by Western blotting. Osthole inhibited the growth of human osteosarcoma MG-63 cells by inhibiting cell proliferation and induced cell apoptosis. Western blotting demonstrated that osthole downregulated the expressions of BCL-2 and caspase-3 and upregulated the expression of BAX in human osteosarcoma cells. Osthole can inhibit osteosarcoma cell proliferation and induced apoptosis effectively in a dose-dependent manner through downregulating the expression of BCL-2 and caspase-3 proteins levels and upregulating the expression of BAX proteins levels.

Dihydroartemisinin-induced apoptosis in human acute monocytic leukemia cells

PubMed Central

Cao, Jia-Tian; Mo, Hui-Min; Wang, Yue; Zhao, Kai; Zhang, Tian-Tian; Wang, Chang-Qian; Xu, Kai-Lin; Han, Zhi-Hua

2018-01-01

Dihydroartemisinin (DHA) is a derivative of artemisinin. The present study aimed to investigate whether DHA induces apoptosis in the THP-1 human acute monocytic leukemia cell line (AMoL), and to identify the relative molecular mechanisms. The results of the present study demonstrated that the viability of THP-1 cells were inhibited by DHA in a dose- and time-dependent manner, which was accompanied by morphological characteristics associated with apoptosis. After 24 h of 200 µM DHA treatment, the proportion of apoptotic cells was significantly increased compared with the untreated controls (P<0.01). In addition, DHA downregulated the levels of B-cell lymphoma (Bcl)-2, protein kinase B (Akt)1, Akt2 and Akt3 gene expression, and increased the expression of the Bcl-2-associated X protein apoptosis regulator. The protein expression of phospho-Akt and phospho-extracellular signal-regulated kinase (ERK) was also decreased, and the protein expression level of cleaved caspase-3 was increased following treatment with DHA. Therefore, DHA may induce apoptosis in the AMoL THP-1 cell line via currently unknown underlying molecular mechanisms, including the downregulation of ERK and Akt, and the activation of caspase-3. PMID:29435054

Microenvironment mesenchymal cells protect ovarian cancer cell lines from apoptosis by inhibiting XIAP inactivation

PubMed Central

Castells, M; Milhas, D; Gandy, C; Thibault, B; Rafii, A; Delord, J-P; Couderc, B

2013-01-01

Epithelial ovarian carcinoma is characterized by high frequency of recurrence (70% of patients) and carboplatin resistance acquisition. Carcinoma-associated mesenchymal stem cells (CA-MSC) have been shown to induce ovarian cancer chemoresistance through trogocytosis. Here we examined CA-MSC properties to protect ovarian cancer cells from carboplatin-induced apoptosis. Apoptosis was determined by Propidium Iodide and Annexin-V-FITC labelling and poly-ADP-ribose polymerase cleavage analysis. We showed a significant increase of inhibitory concentration 50 and a 30% decrease of carboplatin-induced apoptosis in ovarian cancer cells incubated in the presence of CA-MSC-conditioned medium (CM). A molecular analysis of apoptosis signalling pathway in response to carboplatin revealed that the presence of CA-MSC CM induced a 30% decrease of effector caspases-3 and -7 activation and proteolysis activity. CA-MSC secretions promoted Akt and X-linked inhibitor of apoptosis protein (XIAP; caspase inhibitor from inhibitor of apoptosis protein (IAP) family) phosphorylation. XIAP depletion by siRNA strategy permitted to restore apoptosis in ovarian cancer cells stimulated by CA-MSC CM. The factors secreted by CA-MSC are able to confer chemoresistance to carboplatin in ovarian cancer cells through the inhibition of effector caspases activation and apoptosis blockade. Activation of the phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway and the phosphorylation of its downstream target XIAP underlined the implication of this signalling pathway in ovarian cancer chemoresistance. This study reveals the potentialities of targeting XIAP in ovarian cancer therapy. PMID:24176845

Resveratrol protects vascular endothelial cells from high glucose-induced apoptosis through inhibition of NADPH oxidase activation-driven oxidative stress.

PubMed

Chen, Feng; Qian, Li-Hua; Deng, Bo; Liu, Zhi-Min; Zhao, Ying; Le, Ying-Ying

2013-09-01

Hyperglycemia-induced oxidative stress has been implicated in diabetic vascular complications in which NADPH oxidase is a major source of reactive oxygen species (ROS) generation. Resveratrol is a naturally occurring polyphenol, which has vasoprotective effects in diabetic animal models and inhibits high glucose (HG)-induced oxidative stress in endothelial cells. We aimed to examine whether HG-induced NADPH oxidase activation and ROS production contribute to glucotoxicity to endothelial cells and the effect of resveratrol on glucotoxicity. Using a murine brain microvascular endothelial cell line bEnd3, we found that NADPH oxidase inhibitor (apocynin) and resveratrol both inhibited HG-induced endothelial cell apoptosis. HG-induced elevation of NADPH oxidase activity and production of ROS were inhibited by apocynin, suggesting that HG induces endothelial cell apoptosis through NADPH oxidase-mediated ROS production. Mechanistic studies revealed that HG upregulated NADPH oxidase subunit Nox1 but not Nox2, Nox4, and p22(phox) expression through NF-κB activation, which resulted in elevation of NADPH oxidase activity and consequent ROS production. Resveratrol prevented HG-induced endothelial cell apoptosis through inhibiting HG-induced NF-κB activation, NADPH oxidase activity elevation, and ROS production. HG induces endothelial cell apoptosis through NF-κB/NADPH oxidase/ROS pathway, which was inhibited by resveratrol. Our findings provide new potential therapeutic targets against brain vascular complications of diabetes. © 2013 John Wiley & Sons Ltd.

Tubeimoside-1 induces oxidative stress-mediated apoptosis and G0/G1 phase arrest in human prostate carcinoma cells in vitro

PubMed Central

Yang, Jing-bo; Khan, Muhammad; He, Yang-yang; Yao, Min; Li, Yong-ming; Gao, Hong-wen; Ma, Tong-hui

2016-01-01

Aim: Tubeimoside-1 (TBMS1), a triterpenoid saponin extracted from the Chinese herbal medicine Bolbostemma paniculatum (Maxim) Franquet (Cucurbitaceae), has shown anticancer activities in various cancer cell lines. The aim of this study was to investigate the anticancer activity and molecular targets of TBMS1 in human prostate cancer cells in vitro. Methods: DU145 and P3 human prostate cancer cells were treated with TBMS1. Cell viability and apoptosis were detected. ROS generation, mitochondrial membrane potential and cell cycle profile were examined. Western blotting was used to measure the expression of relevant proteins in the cells. Results: TBMS1 (5–100 μmol/L) significantly suppressed the viability of DU145 and P3 cells with IC50 values of approximately 10 and 20 μmol/L, respectively. Furthermore, TBMS1 dose-dependently induced apoptosis and cell cycle arrest at G0/G1 phase in DU145 and P3 cells. In DU145 cells, TBMS1 induced mitochondrial apoptosis, evidenced by ROS generation, mitochondrial dysfunction, endoplasmic reticulum stress, modulated Bcl-2 family protein and cleaved caspase-3, and activated ASK-1 and its downstream targets p38 and JNK. The G0/G1 phase arrest was linked to increased expression of p53 and p21 and decreased expression of cyclin E and cdk2. Co-treatment with Z-VAD-FMK (pan-caspase inhibitor) could attenuate TBMS1-induced apoptosis but did not prevent G0/G1 arrest. Moreover, co-treatment with NAC (ROS scavenger), SB203580 (p38 inhibitor), SP600125 (JNK inhibitor) or salubrinal (ER stress inhibitor) significantly attenuated TBMS1-induced apoptosis. Conclusion: TBMS1 induces oxidative stress-mediated apoptosis in DU145 human prostate cancer cells in vitro via the mitochondrial pathway. PMID:27292614

A synthetic peptide targeting the BH4 domain of Bcl-2 induces apoptosis in multiple myeloma and follicular lymphoma cells alone or in combination with agents targeting the BH3-binding pocket of Bcl-2.

PubMed

Lavik, Andrew R; Zhong, Fei; Chang, Ming-Jin; Greenberg, Edward; Choudhary, Yuvraj; Smith, Mitchell R; McColl, Karen S; Pink, John; Reu, Frederic J; Matsuyama, Shigemi; Distelhorst, Clark W

2015-09-29

Bcl-2 inhibits apoptosis by two distinct mechanisms but only one is targeted to treat Bcl-2-positive malignancies. In this mechanism, the BH1-3 domains of Bcl-2 form a hydrophobic pocket, binding and inhibiting pro-apoptotic proteins, including Bim. In the other mechanism, the BH4 domain mediates interaction of Bcl-2 with inositol 1,4, 5-trisphosphate receptors (IP3Rs), inhibiting pro-apoptotic Ca2+ signals. The current anti-Bcl-2 agents, ABT-263 (Navitoclax) and ABT-199 (Venetoclax), induce apoptosis by displacing pro-apoptotic proteins from the hydrophobic pocket, but do not inhibit Bcl-2-IP3R interaction. Therefore, to target this interaction we developed BIRD-2 (Bcl-2 IP3 Receptor Disruptor-2), a decoy peptide that binds to the BH4 domain, blocking Bcl-2-IP3R interaction and thus inducing Ca2+-mediated apoptosis in chronic lymphocytic leukemia, multiple myeloma, and follicular lymphoma cells, including cells resistant to ABT-263, ABT-199, or the Bruton's tyrosine kinase inhibitor Ibrutinib. Moreover, combining BIRD-2 with ABT-263 or ABT-199 enhances apoptosis induction compared to single agent treatment. Overall, these findings provide strong rationale for developing novel therapeutic agents that mimic the action of BIRD-2 in targeting the BH4 domain of Bcl-2 and disrupting Bcl-2-IP3R interaction.

Kinetics of apoptotic markers in exogeneously induced apoptosis of EL4 cells.

PubMed

Jessel, Robert; Haertel, Steffen; Socaciu, Carmen; Tykhonova, Svetlana; Diehl, Horst A

2002-01-01

We investigated the time-dependence of apoptotic events in EL4 cells by monitoring plasma membrane changes in correlation to DNA fragmentation and cell shrinkage. We applied three apoptosis inducers (staurosporine, tubericidine and X-rays) and we looked at various markers to follow the early-to-late apoptotic events: phospholipid translocation (identified through annexin V-fluorescein assay and propidium iodide), lipid package (via merocyanine assay), membrane fluidity and anisotropy (via fluorescent measurements), DNA fragmentation by the fluorescence-labeling test and cell size measurements. The different apoptotic inducers caused different reactions of the cells: staurosporine induced apoptosis most rapidly in a high number of cells, tubercidine triggered apoptosis only in the S phase cells, while X-rays caused a G2/M arrest and subsequently apoptosis. Loss of lipid asymmetry is promptly detectable after one hour of incubation time. The phosphatidylserine translocation, decrease of lipid package and anisotropy, and the increase of membrane fluidity appeared to be based on the same process of lipid asymmetry loss. Therefore, the DNA fragmentation and the cell shrinkage appear to be parallel and independent processes running on different time scales but which are kinetically inter-related. The results indicate different signal steps to apoptosis dependent on inducer characteristics but the kinetics of "early-to-late" apoptosis appears to be a fixed program.

Caspase-mediated cleavage of Beclin1 inhibits autophagy and promotes apoptosis induced by S1 in human ovarian cancer SKOV3 cells.

PubMed

Li, Xiaoning; Su, Jing; Xia, Meihui; Li, Hongyan; Xu, Ye; Ma, Chunhui; Ma, Liwei; Kang, Jingsong; Yu, Huimei; Zhang, Zhichao; Sun, Liankun

2016-02-01

S1, a novel BH3 mimetic, can induce apoptosis dependent on Bax/Bak through inhibition of Bcl-2 in various tumors. S1 also induces autophagy through interrupting the interaction of Bcl-2 and Beclin1. Our results showed that S1 induces apoptosis in human ovarian cancer SKOV3 cells in a time- and dose-dependent manner. Autophagy precedes apoptosis, in SKOV3 cells treated with S1 (6 μmol/L), autophagy reached the maximum peak at 12 h after treatment and decreased to 24 h. In SKOV3 cells treated with different concentrations of S1 for 24 h, the highest level of autophagy was observed with 5 μmol/L and decreased to 10 μmol/L. Autophagy inhibitors 3-MA and CQ enhanced apoptosis induced by S1 in SKOV3 cells. However, overactivation of caspases in apoptosis induced by S1 may inhibit the autophagy-inducing function of Beclin1. Because the pan-caspase inhibitor Z-VAD recovered the autophagy-inducing function of Beclin1 through reduction of activated caspase-mediated cleavage of Beclin1. Furthermore, the Beclin1 cleavage products could further increase apoptosis induced by S1 in SKOV3 cells. This indicates that apoptosis induced by high doses and long exposure of S1 causes the overactivation of caspases and subsequent cleavage of Beclin1, and inhibits the protection of autophagy. Moreover, the cleaved product of Beclin1 further promotes apoptosis induced by S1 in SKOV3 cells. Our results suggest this may be a molecular mechanism for enhancing the sensitivity of cancer cells to apoptosis induced by small molecular compound targeting Bcl-2.

Dual-Functional Nanographene Oxide as Cancer-Targeted Drug-Delivery System to Selectively Induce Cancer-Cell Apoptosis.

PubMed

Zhou, Binwei; Huang, Yanyu; Yang, Fang; Zheng, Wenjie; Chen, Tianfeng

2016-04-05

Construction of bioresponsive drug-delivery nanosystems could enhance the anticancer efficacy of anticancer agents and reduce their toxic side effects. Herein, by using transferrin (Tf) as a surface decorator, we constructed a cancer-targeted nanographene oxide (NGO) nanosystem for use in drug delivery. This nanosystem (Tf-NGO@HPIP) drastically enhanced the cellular uptake, retention, and anticancer efficacy of loaded drugs but showed much lower toxicity to normal cells. The nanosystem was internalized through receptor-mediated endocytosis and triggered pH-dependent drug release in acidic environments and in the presence of cellular enzymes. Moreover, Tf-NGO@HPIP effectively induced cancer-cell apoptosis through activation of superoxide-mediated p53 and MAPK pathways along with inactivation of ERK and AKT. Taken together, this study demonstrates a good strategy for the construction of bioresponsive NGO drug-delivery nanosystems and their use as efficient anticancer drug carriers. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High glucose induces apoptosis via upregulation of Bim expression in proximal tubule epithelial cells.

PubMed

Zhang, Xiao-Qian; Dong, Jian-Jun; Cai, Tian; Shen, Xue; Zhou, Xiao-Jun; Liao, Lin

2017-04-11

Diabetic nephropathy is the primary cause of end-stage renal disease. Apoptosis of tubule epithelial cells is a major feature of diabetic nephropathy. The mechanisms of high glucose (HG) induced apoptosis are not fully understood. Here we demonstrated that, HG induced apoptosis via upregulating the expression of proapoptotic Bcl-2 homology domain 3 (BH3)-only protein Bim protein, but not bring a significant change in the baseline level of autophagy in HK2 cells. The increase of Bim expression was caused by the ugregulation of transcription factors, FOXO1 and FOXO3a. Bim expression initiates BAX/BAK-mediated mitochondria-dependent apoptosis. Silence of Bim by siRNA in HK2 cells prevented HG-induced apoptosis and also sensitized HK2 cells to autophagy during HG treatment. The autophagy inhibitor 3-MA increased the injury in Bim knockdown HK2 cells by retriggering apoptosis. The above results suggest a Bim-independent apoptosis pathway in HK2 cells, which normally could be inhibited by autophagy. Overall, our results indicate that HG induces apoptosis via up-regulation of Bim expression in proximal tubule epithelial cells.

Alpha-tocopheryl succinate induces apoptosis by targeting ubiquinone-binding sites in mitochondrial respiratory complex II.

PubMed

Dong, L-F; Low, P; Dyason, J C; Wang, X-F; Prochazka, L; Witting, P K; Freeman, R; Swettenham, E; Valis, K; Liu, J; Zobalova, R; Turanek, J; Spitz, D R; Domann, F E; Scheffler, I E; Ralph, S J; Neuzil, J

2008-07-17

Alpha-tocopheryl succinate (alpha-TOS) is a selective inducer of apoptosis in cancer cells, which involves the accumulation of reactive oxygen species (ROS). The molecular target of alpha-TOS has not been identified. Here, we show that alpha-TOS inhibits succinate dehydrogenase (SDH) activity of complex II (CII) by interacting with the proximal and distal ubiquinone (UbQ)-binding site (Q(P) and Q(D), respectively). This is based on biochemical analyses and molecular modelling, revealing similar or stronger interaction energy of alpha-TOS compared to that of UbQ for the Q(P) and Q(D) sites, respectively. CybL-mutant cells with dysfunctional CII failed to accumulate ROS and underwent apoptosis in the presence of alpha-TOS. Similar resistance was observed when CybL was knocked down with siRNA. Reconstitution of functional CII rendered CybL-mutant cells susceptible to alpha-TOS. We propose that alpha-TOS displaces UbQ in CII causing electrons generated by SDH to recombine with molecular oxygen to yield ROS. Our data highlight CII, a known tumour suppressor, as a novel target for cancer therapy.

α-Tocopheryl succinate induces apoptosis by targeting ubiquinone-binding sites in mitochondrial respiratory complex II

PubMed Central

Dong, Lan-Feng; Low, Pauline; Dyason, Jeffrey C.; Wang, Xiu-Fang; Prochazka, Lubomir; Witting, Paul K.; Freeman, Ruth; Swettenham, Emma; Valis, Karel; Liu, Ji; Zobalova, Renata; Turanek, Jaroslav; Spitz, Doug R.; Domann, Frederick E.; Scheffler, Immo E.; Ralph, Stephen J.; Neuzil, Jiri

2009-01-01

α-Tocopheryl succinate (α-TOS) is a selective inducer of apoptosis in cancer cells, which involves the accumulation of reactive oxygen species (ROS). The molecular target of α-TOS has not been identified. Here we show that α-TOS inhibits succinate dehydrogenase (SDH) activity of complex II (CII) by interacting with the proximal and distal ubiquinone (UbQ) binding site (QP and QD, respectively). This is based on biochemical analyses and molecular modelling, revealing similar or stronger interaction energy of α-TOS compared to that of UbQ for the QP and QD sites, respectively. CybL-mutant cells with dysfunctional CII failed to accumulate ROS and undergo apoptosis in the presence of α-TOS. Similar resistance was observed when CybL was knocked down with siRNA. Reconstitution of functional CII rendered CybL-mutant cells susceptible to α-TOS. We propose that α-TOS displaces UbQ in CII causing electrons generated by SDH to recombine with molecular oxygen to yield ROS. Our data highlight CII, a known tumour suppressor, as a novel target for cancer therapy. PMID:18372923

CHOP Contributes to, But Is Not the Only Mediator of, IAPP Induced β-Cell Apoptosis.

PubMed

Gurlo, T; Rivera, J F; Butler, A E; Cory, M; Hoang, J; Costes, S; Butler, Peter C

2016-04-01

The islet in type 2 diabetes is characterized by β-cell loss, increased β-cell apoptosis, and islet amyloid derived from islet amyloid polypeptide (IAPP). When protein misfolding protective mechanisms are overcome, human IAPP (h-IAPP) forms membrane permeant toxic oligomers that induce β-cell dysfunction and apoptosis. In humans with type 2 diabetes (T2D) and mice transgenic for h-IAPP, endoplasmic reticulum (ER) stress has been inferred from nuclear translocation of CCAAT/enhancer-binding protein homologous protein (CHOP), an established mediator of ER stress. To establish whether h-IAPP toxicity is mediated by ER stress, we evaluated diabetes onset and β-cell mass in h-IAPP transgenic (h-TG) mice with and without deletion of CHOP in comparison with wild-type controls. Diabetes was delayed in h-TG CHOP(-/-) mice, with relatively preserved β-cell mass and decreased β-cell apoptosis. Deletion of CHOP attenuates dysfunction of the autophagy/lysosomal pathway in β-cells of h-TG mice, uncovering a role for CHOP in mediating h-IAPP-induced dysfunction of autophagy. As deletion of CHOP delayed but did not prevent h-IAPP-induced β-cell loss and diabetes, we examined CHOP-independent stress pathways. JNK, a target of the IRE-1pTRAF2 complex, and the Bcl-2 family proapoptotic mediator BIM, a target of ATF4, were comparably activated by h-IAPP expression in the presence and absence of CHOP. Therefore, although these studies affirm that CHOP is a mediator of h-IAPP-induced ER stress, it is not the only one. Therefore, suppression of CHOP alone is unlikely to be a durable therapeutic strategy to protect against h-IAPP toxicity because multiple stress pathways are activated.

Noxa/Mcl-1 Balance Regulates Susceptibility of Cells to Camptothecin-Induced Apoptosis1

PubMed Central

Mei, Yide; Xie, Chongwei; Xie, Wei; Tian, Xu; Li, Mei; Wu, Mian

2007-01-01

Although camptothecin (CPT) has been reported to induce apoptosis in various cancer cells, the molecular details of this regulation remain largely unknown. In this study, we demonstrate that BH3-only protein Noxa is upregulated during CPT-induced apoptosis, which is independent of p53. In addition, we show that phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway is responsible for Noxa's induction. Luciferase assay and cAMP response element binding protein (CREB) knockdown experiments further demonstrate that CREB is involved in the transcriptional upregulation of Noxa. Moreover, blocking Noxa expression using specific small interfering ribonucleic acid (siRNA) significantly reduces the apoptosis in response to CPT, indicating that Noxa is an essential mediator for CPT-induced apoptosis. Interestingly, antiapoptotic Mcl-1 was also upregulated through PI3K/Akt signaling pathway upon CPT treatment. Using immunoprecipitation assay, Noxa was found to interact with Mcl-1 in the presence or absence of CPT. Knockdown of Mcl-1 expression by short hairpin ribonucleic acid (shRNA) was shown to potentiate CPT-induced apoptosis. Consistently, ectopic overexpression of Mcl-1 rescued cells from apoptosis induced by CPT. Cells coexpressing Noxa and Mcl-1 at different ratio correlates well with the extent of apoptosis, suggesting that the balance between Noxa and Mcl-1 may determine the susceptibility of HeLa cells to CPT-induced apoptosis. PMID:17971907

Dihydroartemisinin Inhibits Glucose Uptake and Cooperates with Glycolysis Inhibitor to Induce Apoptosis in Non-Small Cell Lung Carcinoma Cells

PubMed Central

Gao, Jing; Luo, Xian-yang; Liu, Yu; Li, Ning; Li, Chun-lei; Chen, Yu-qiang; Yu, Xiu-yi; Jiang, Jie

2015-01-01

Despite recent advances in the therapy of non-small cell lung cancer (NSCLC), the chemotherapy efficacy against NSCLC is still unsatisfactory. Previous studies show the herbal antimalarial drug dihydroartemisinin (DHA) displays cytotoxic to multiple human tumors. Here, we showed that DHA decreased cell viability and colony formation, induced apoptosis in A549 and PC-9 cells. Additionally, we first revealed DHA inhibited glucose uptake in NSCLC cells. Moreover, glycolytic metabolism was attenuated by DHA, including inhibition of ATP and lactate production. Consequently, we demonstrated that the phosphorylated forms of both S6 ribosomal protein and mechanistic target of rapamycin (mTOR), and GLUT1 levels were abrogated by DHA treatment in NSCLC cells. Furthermore, the upregulation of mTOR activation by high expressed Rheb increased the level of glycolytic metabolism and cell viability inhibited by DHA. These results suggested that DHA-suppressed glycolytic metabolism might be associated with mTOR activation and GLUT1 expression. Besides, we showed GLUT1 overexpression significantly attenuated DHA-triggered NSCLC cells apoptosis. Notably, DHA synergized with 2-Deoxy-D-glucose (2DG, a glycolysis inhibitor) to reduce cell viability and increase cell apoptosis in A549 and PC-9 cells. However, the combination of the two compounds displayed minimal toxicity to WI-38 cells, a normal lung fibroblast cell line. More importantly, 2DG synergistically potentiated DHA-induced activation of caspase-9, -8 and -3, as well as the levels of both cytochrome c and AIF of cytoplasm. However, 2DG failed to increase the reactive oxygen species (ROS) levels elicited by DHA. Overall, the data shown above indicated DHA plus 2DG induced apoptosis was involved in both extrinsic and intrinsic apoptosis pathways in NSCLC cells. PMID:25799586

Dihydroartemisinin inhibits glucose uptake and cooperates with glycolysis inhibitor to induce apoptosis in non-small cell lung carcinoma cells.

PubMed

Mi, Yan-jun; Geng, Guo-jun; Zou, Zheng-zhi; Gao, Jing; Luo, Xian-yang; Liu, Yu; Li, Ning; Li, Chun-lei; Chen, Yu-qiang; Yu, Xiu-yi; Jiang, Jie

2015-01-01

Despite recent advances in the therapy of non-small cell lung cancer (NSCLC), the chemotherapy efficacy against NSCLC is still unsatisfactory. Previous studies show the herbal antimalarial drug dihydroartemisinin (DHA) displays cytotoxic to multiple human tumors. Here, we showed that DHA decreased cell viability and colony formation, induced apoptosis in A549 and PC-9 cells. Additionally, we first revealed DHA inhibited glucose uptake in NSCLC cells. Moreover, glycolytic metabolism was attenuated by DHA, including inhibition of ATP and lactate production. Consequently, we demonstrated that the phosphorylated forms of both S6 ribosomal protein and mechanistic target of rapamycin (mTOR), and GLUT1 levels were abrogated by DHA treatment in NSCLC cells. Furthermore, the upregulation of mTOR activation by high expressed Rheb increased the level of glycolytic metabolism and cell viability inhibited by DHA. These results suggested that DHA-suppressed glycolytic metabolism might be associated with mTOR activation and GLUT1 expression. Besides, we showed GLUT1 overexpression significantly attenuated DHA-triggered NSCLC cells apoptosis. Notably, DHA synergized with 2-Deoxy-D-glucose (2DG, a glycolysis inhibitor) to reduce cell viability and increase cell apoptosis in A549 and PC-9 cells. However, the combination of the two compounds displayed minimal toxicity to WI-38 cells, a normal lung fibroblast cell line. More importantly, 2DG synergistically potentiated DHA-induced activation of caspase-9, -8 and -3, as well as the levels of both cytochrome c and AIF of cytoplasm. However, 2DG failed to increase the reactive oxygen species (ROS) levels elicited by DHA. Overall, the data shown above indicated DHA plus 2DG induced apoptosis was involved in both extrinsic and intrinsic apoptosis pathways in NSCLC cells.

Single-cell analysis of dihydroartemisinin-induced apoptosis through reactive oxygen species-mediated caspase-8 activation and mitochondrial pathway in ASTC-a-1 cells using fluorescence imaging techniques

NASA Astrophysics Data System (ADS)

Lu, Ying-Ying; Chen, Tong-Sheng; Wang, Xiao-Ping; Li, Li

2010-07-01

Dihydroartemisinin (DHA), a front-line antimalarial herbal compound, has been shown to possess promising anticancer activity with low toxicity. We have previously reported that DHA induced caspase-3-dependent apoptosis in human lung adenocarcinoma cells. However, the cellular target and molecular mechanism of DHA-induced apoptosis is still poorly defined. We use confocal fluorescence microscopy imaging, fluorescence resonance energy transfer, and fluorescence recovery after photobleaching techniques to explore the roles of DHA-elicited reactive oxygen species (ROS) in the DHA-induced Bcl-2 family proteins activation, mitochondrial dysfunction, caspase cascade, and cell death. Cell Counting Kit-8 assay and flow cytometry analysis showed that DHA induced ROS-mediated apoptosis. Confocal imaging analysis in a single living cell and Western blot assay showed that DHA triggered ROS-dependent Bax translocation, mitochondrial membrane depolarization, alteration of mitochondrial morphology, cytochrome c release, caspase-9, caspase-8, and caspase-3 activation, indicating the coexistence of ROS-mediated mitochondrial and death receptor pathway. Collectively, our findings demonstrate for the first time that DHA induces cell apoptosis by triggering ROS-mediated caspase-8/Bid activation and the mitochondrial pathway, which provides some novel insights into the application of DHA as a potential anticancer drug and a new therapeutic strategy by targeting ROS signaling in lung adenocarcinoma therapy in the future.

Gallic Acid Induces Apoptosis in Human Gastric Adenocarcinoma Cells.

PubMed

Tsai, Chung-Lin; Chiu, Ying-Ming; Ho, Tin-Yun; Hsieh, Chin-Tung; Shieh, Dong-Chen; Lee, Yi-Ju; Tsay, Gregory J; Wu, Yi-Ying

2018-04-01

Gastric cancer is one of the most common malignant cancers with a poor prognosis and high mortality rate worldwide. Current treatment of gastric cancer includes surgery and chemotherapy as the main modalities, but the potentially severe side-effects of chemotherapy present a considerable challenge. Gallic acid is a trihydroxybenzoic acid found to exert an anticancer effect against a variety of cancer cells. The purpose of this study was to determine the anti-cancer activity of Galla chinensis and its main component gallic acid on human gastric adenocarcinoma cells. MTT assay and cell death ELISA were used to determine the apoptotic effect of Gallic Chinensis and gallic acid on human gastric adenocarcinoma cells. To determine the pathway and relevant components by which gallic acid-induced apoptosis is mediated through, cells were transfected with siRNA (Fas, FasL, DR5, p53) using Lipofectamine 2000. Reults: Gallic Chinensis and gallic acid induced apoptosis of human gastric adenocarcinoma cells. Gallic acid induced up-regulation of Fas, FasL, and DR5 expression in AGS cells. Transfection of cells with Fas, FasL, or DR5 siRNA reduced gallic acid-induced cell death. In addition, p53 was shown to be involved in gallic acid-mediated Fas, FasL, and DR5 expression as well as cell apoptosis in AGS cells. These results suggest that gallic acid has a potential role in the treatment of gastric cancer. Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Upregulation of erythropoietin receptor in UT-7/EPO cells inhibits simulated microgravity-induced cell apoptosis

NASA Astrophysics Data System (ADS)

Zou, Li-xue; Cui, Shao-yan; Zhong, Jian; Yi, Zong-chun; Sun, Yan; Fan, Yu-bo; Zhuang, Feng-yuan

2011-07-01

Hematopoietic progenitor cell proliferation can be altered in either spaceflight or under simulated microgravity experiments on the ground, however, the underlying mechanism remains unknown. Our previous study showed that exposure of the human erythropoietin (EPO)-dependent leukemia cell line UT-7/EPO to conditions of simulated microgravity significantly inhibited the cellular proliferation rate and induced cell apoptosis. We postulated that the downregulation of the erythropoietin receptor (EPOR) expression in UT-7/EPO cells under simulated microgravity may be a possible reason for microgravity triggered apoptosis. In this paper, a human EPOR gene was transferred into UT-7/EPO cells and the resulting expression of EPOR on the surface of UT-7/EPO cells increased approximately 61% ( p < 0.05) as selected by the antibiotic G418. It was also shown through cytometry assays and morphological observations that microgravity-induced apoptosis markedly decreased in these UT-7/EPO-EPOR cells. Thus, we concluded that upregulation of EPOR in UT-7/EPO cells could inhibit the simulated microgravity-induced cell apoptosis in this EPO dependent cell line.

6-shogaol induces autophagic cell death then triggered apoptosis in colorectal adenocarcinoma HT-29 cells.

PubMed

Li, Ting-Yi; Chiang, Been-Huang

2017-09-01

6-shogaol is a phytochemical of dietary ginger, we found that 6-shogaol could induced both autophagic and apoptotic death in human colon adenocarcinoma (HT-29) cells. Results of this study showed that 6-shogal induced cell cycle arrest, autophagy, and apoptosis in HT-29 cells in a time sequence. After 6h, 6-shogal induced apparent G2/M arrest, then the HT-29 cells formed numerous autophagosomes in each phase of the cell cycle. After 18h, increases in acidic vesicles and LAMP-1 (Lysosome-associated membrane proteins 1) showed that 6-shogaol had caused autophagic cell death. After 24h, cell shrinkage and Caspase-3/7 activities rising, suggesting that apoptotic cell death had increased. And after 48h, the result of TUNEL assay indicated the highest occurrence of apoptosis upon 6-shogaol treatment. It appeared that apoptosis is triggered by autophagy in 6-shogaol treated HT-29 cells, the damage of autophagic cell death initiated apoptosis program. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Knockdown of HIF-1α and IL-8 induced apoptosis of hepatocellular carcinoma triggers apoptosis of vascular endothelial cells.

PubMed

Choi, Sung Hoon; Park, Jun Yong; Kang, Wonseok; Kim, Seung Up; Kim, Do Young; Ahn, Sang Hoon; Ro, Simon Wonsang; Han, Kwang-Hyub

2016-01-01

A local hypoxic microenvironment is one of the most important characteristics of solid tumors. Hypoxia inducible factor-1α (HIF-1α) and Interleukin-8 (IL-8) activate tumor survival from hypoxic-induced apoptosis in each pathway. This study aimed to evaluate whether knockdown of HIF-1α and IL-8 induced apoptosis of the hepatocellular carcinoma (HCC) and endothelial cell lines. HCC cell lines were infected with adenovirus-expressing shRNA for HIF-1α and IL-8 and maintained under hypoxic conditions (1% O2, 24 h). The expression levels of HIF-1α and both apoptotic and growth factors were examined by real-time quantitative PCR and western blot. We also investigated apoptosis by TUNEL assay (FACS and Immunofluorescence) and measured the concentration of cytochrome C. Inhibition of HIF-1α and IL-8 up-regulated the expression of apoptotic factors while downregulating anti-apoptotic factors simultaneously. Knockdown of HIF-1α and IL-8 increased the concentration of cytochrome C and enhanced DNA fragmentation in HCC cell lines. Moreover, culture supernatant collected from the knockdown of HIF-1α and IL-8 in HCC cell lines induced apoptosis in human umbilical vein endothelial cells under hypoxia, and the expression of variable apoptotic ligand increased from HCC cell lines, time-dependently. These data suggest that adenovirus-mediated knockdown of HIF-1α and IL-8 induced apoptosis in HCC cells and triggered apoptosis of vascular endothelial cells.

An Antimicrobial Peptidomimetic Induces Mucorales Cell Death through Mitochondria-Mediated Apoptosis

PubMed Central

Barbu, E. Magda; Shirazi, Fazal; McGrath, Danielle M.; Albert, Nathaniel; Sidman, Richard L.; Pasqualini, Renata; Arap, Wadih; Kontoyiannis, Dimitrios P.

2013-01-01

The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK)2 with pleiotropic action ranging from targeted (i.e., ligand-directed) activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK)2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK)2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS), and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK)2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections. PMID:24098573

An antimicrobial peptidomimetic induces Mucorales cell death through mitochondria-mediated apoptosis.

PubMed

Barbu, E Magda; Shirazi, Fazal; McGrath, Danielle M; Albert, Nathaniel; Sidman, Richard L; Pasqualini, Renata; Arap, Wadih; Kontoyiannis, Dimitrios P

2013-01-01

The incidence of mucormycosis has dramatically increased in immunocompromised patients. Moreover, the array of cellular targets whose inhibition results in fungal cell death is rather limited. Mitochondria have been mechanistically identified as central regulators of detoxification and virulence in fungi. Our group has previously designed and developed a proteolytically-resistant peptidomimetic motif D(KLAKLAK)2 with pleiotropic action ranging from targeted (i.e., ligand-directed) activity against cancer and obesity to non-targeted activity against antibiotic resistant gram-negative rods. Here we evaluated whether this non-targeted peptidomimetic motif is active against Mucorales. We show that D(KLAKLAK)2 has marked fungicidal action, inhibits germination, and reduces hyphal viability. We have also observed cellular changes characteristic of apoptosis in D(KLAKLAK)2-treated Mucorales cells. Moreover, the fungicidal activity was directly correlated with vacuolar injury, mitochondrial swelling and mitochondrial membrane depolarization, intracellular reactive oxygen species accumulation (ROS), and increased caspase-like enzymatic activity. Finally, these apoptotic features were prevented by the addition of the ROS scavenger N-acetyl-cysteine indicating mechanistic pathway specificity. Together, these findings indicate that D(KLAKLAK)2 makes Mucorales exquisitely susceptible via mitochondrial injury-induced apoptosis. This prototype may serve as a candidate drug for the development of translational applications against mucormycosis and perhaps other fungal infections.

Tryptophol induces death receptor (DR) 5-mediated apoptosis in U937 cells.

PubMed

Inagaki, Shyuichiro; Morimura, Shigeru; Tang, Yueqin; Akutagawa, Hiroshi; Kida, Kenji

2007-08-01

Tryptophol is a natural component isolated from vinegar produced from the boiled extract of black soybean. We have reported that tryptophol induces apoptosis in U937 cells via activation of caspase-8 followed by caspase-3. Tryptophol, however, did not affect human peripheral blood lymphocytes (PBL). In this study, we found that tryptophol enhances formation of a death-inducing signaling complex including death receptor (DR) 5. Cell viability and induction of apoptosis by tryptophol was reduced by transfection with decoy receptor (DcR) 1. These results indicate that tryptophol induces apoptosis through DR5 and that the resistance of PBL to tryptophol-induced apoptosis might be due to competition from DcR1.

Protective role of Nrf2 against mechanical-stretch-induced apoptosis in mouse fibroblasts: a potential therapeutic target of mechanical-trauma-induced stress urinary incontinence.

PubMed

Li, Qiannan; Li, Bingshu; Liu, Cheng; Wang, Linlin; Tang, Jianming; Hong, Li

2018-01-10

We investigated the protective effect and underlying molecular mechanism of nuclear factor-E2-related factor 2 (Nrf2) against mechanical-stretch-induced apoptosis in mouse fibroblasts. Normal cells, Nrf2 silencing cells, and Nrf2 overexpressing cells were respectively divided into two groups-nonintervention and cyclic mechanical strain (CMS)-subjected to CMS of 5333 μ (1.0 Hz for 4 h), six groups in total (control, CMS, shNfe212, shNfe212 + CMS, LV-shNfe212, and LV-shNfe212 + CMS). After treatment, cell apoptosis; cell-cycle distribution; expressions of Nrf2, Bax, Bcl-2, Cyt-C, caspase-3, caspase-9, cleaved-caspase-3, and cleaved-caspase-9; mitochondrial membrane potential (ΔΨm); reactive oxygen species (ROS); and malondialdehyde (MDA) levels were measured. Thirty virgin female C57BL/6 mice were divided into two groups: control (without intervention) and vaginal distension (VD) groups, which underwent VD for 1 h with an 8-mm dilator (0.3 ml saline). Leak-point pressure (LPP) was tested on day 7 after VD; Nrf2 expression, apoptosis, and MDA levels were then measured in urethra and anterior vaginal wall. Mechanical stretch decreased Nrf2 messenger RNA (mRNA) and protein expressions. Overexpression of Nrf2 alleviated mechanical-stretch-induced cell apoptosis; S-phase arrest of cell cycle; up-regulation of Bax, cytochrome C (Cyt-C), ROS, MDA, ratio of cleaved-caspase-3/caspase-3 and cleaved-caspase-9/caspase-9; and exacerbated the decrease of Bcl2 and ΔΨm in L929 cells. On the contrary, silencing of Nrf2 showed opposite effects. Besides, VD reduced LPP levels and Nrf2 expression and increased cell apoptosis and MDA generation in the urethra and anterior vaginal wall. Nrf2 exhibits a protective role against mechanical-stretch -induced apoptosis on mouse fibroblasts, which might indicate a potential therapeutic target of mechanical-trauma-induced stress urinary incontinence (SUI).

Apigenin induced apoptosis in esophageal carcinoma cells by destruction membrane structures.

PubMed

Zhu, Haiyan; Jin, Hua; Pi, Jiang; Bai, Haihua; Yang, Fen; Wu, Chaomin; Jiang, Jinhuan; Cai, Jiye

2016-07-01

Apigenin has shown to have killing effects on some kinds of solid tumor cells. However, the changes in cell membrane induced by apigenin on subcellular- or nanometer-level were still unclear. In this work, human esophageal cancer cells (EC9706 and KYSE150 cells) were employed as cell model to detect the cytotoxicity of apigenin, including cell growth inhibition, apoptosis induction, membrane toxicity, etc. MTT assay showed that apigenin could remarkably inhibit the growth and proliferation in both types of cells. Annexin V/PI-based flow cytometry analysis showed that the cytotoxic effects of apigenin in KYSE150 cells were mainly through early apoptosis induction, while in EC9706 cells, necrosis, and apoptosis were both involved in cell death. The morphological and ultrastructural properties induced by apigenin were investigated at single cellular- or nanometer-level using atomic force microscopy (AFM). Additionally, lactate dehydrogenase (LDH) leakage was measured to assess the changes in membrane permeability. The results indicated that apigenin increased the membrane permeability and caused leakage of LDH, which was consistent with damages on membrane ultrastructure detected by AFM. Therefore, membrane toxicity, including membrane ultrastructure damages and enhanced membrane permeability, played vital roles in apigenin induced human esophageal cancer cell apoptosis. SCANNING 38:322-328, 2016. © 2015 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Aminomethylphosphonic Acid and Methoxyacetic Acid Induce Apoptosis in Prostate Cancer Cells

PubMed Central

Parajuli, Keshab R.; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2015-01-01

Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer. PMID:26006246

Aminomethylphosphonic acid and methoxyacetic acid induce apoptosis in prostate cancer cells.

PubMed

Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; You, Zongbing

2015-05-22

Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.

TRAIL Enhances Shikonin Induced Apoptosis through ROS/JNK Signaling in Cholangiocarcinoma Cells.

PubMed

Zhou, Guangyao; Yang, Zuqin; Wang, Xiaodong; Tao, Ran; Zhou, Yuanping

2017-01-01

Cholangiocarcinoma (CCA), arising from varying locations within the biliary tree, is the second most common primary liver malignancy worldwide. Shikonin, an active compound extracted from the Chinese herb Zicao, holds anti-bacterial, anti-inflammatory, and anti-tumor activities. However, the effect of shikonin on human cholangiocarcinoma and detailed mechanisms of TRAIL enhancement remains to be elucidated. The purpose of the study was to investigate the protective functions of TRAIL enhancement for shikonin induced apoptosis in cholangiocarcinoma cells. We use MTT assay, apoptosis assay, caspase activity assay, flow cytometry assay, real time PCR and Western blot to observe the effects of TRAIL on shikonin induced cholangiocarcinoma cells apoptosis and its mechanism. Shikonin inhibited cell viability and induced apoptosis of CCA cells, effects enhanced by TRAIL treatment via activation of caspase-3, -8, -9. Furhermore, TRAIL enhanced anti-proliferation of shikonin and shikonin induced apoptosis through induction of ROS mediated JNK activation, while AKT activation had an effect on shikonin anti-proliferation activity, but not in the TRAIL enhanced counterparts. Finally, shikonin upregulated DR5 expression, an effect essential for TRAIL-enhanced activities of shikonin in RBE cells. Our results revealed that shikonin could inhibit cells viability and induce apoptosis of CCA cells, effects enhanced by TRAIL treatment via ROS mediated JNK signalling pathways, involving up-regulation of DR5 expression. Our results provide further insight into the mechanism underlying the anti-tumor effects of shikonin by TRAIL enhanced in CCA and a new therapeutic strategy to CCA treatment. © 2017 The Author(s). Published by S. Karger AG, Basel.

Interference of silibinin with IGF-1R signalling pathways protects human epidermoid carcinoma A431 cells from UVB-induced apoptosis

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

Liu, Weiwei; Otkur, Wuxiyar; Li, Lingzhi

Highlights: ► Silibinin protects A431 cells from UVB irradiation-induced apoptosis. ► Up-regulation of the IGF-1R-JNK/ERK pathways by UVB induces cell apoptosis. ► Silibinin inhibits IGF-1R pathways to repress caspase-8-mediated apoptosis. -- Abstract: Ultraviolet B (UVB) from sunlight is a major cause of cutaneous lesion. Silibinin, a traditional hepatic protectant, elicits protective effects against UVB-induced cellular damage. In A431 cells, the insulin-like growth factor-1 receptor (IGF-1R) was markedly up-regulated by UVB irradiation. The activation of the IGF-1R signalling pathways contributed to apoptosis of the cells rather than rescuing the cells from death. Up-regulated IGF-1R stimulated downstream mitogen-activated protein kinases (MAPKs), suchmore » as c-Jun N-terminal kinases (JNK) and extracellular signal-regulated protein kinases 1/2 (ERK1/2). The subsequent activation of caspase-8 and caspase-3 led to apoptosis. The activation of IGF-1R signalling pathways is the cause of A431 cell death. The pharmacological inhibitors and the small interfering RNA (siRNA) targeting IGF-1R suppressed the downstream activation of JNK/ERK-caspases to help the survival of the UVB-irradiated A431 cells. Indeed, silibinin treatment suppressed the IGF-1R-JNK/ERK pathways and thus protected the cells from UVB-induced apoptosis.« less

Evodiamine Induces Cell Growth Arrest, Apoptosis and Suppresses Tumorigenesis in Human Urothelial Cell Carcinoma Cells.

PubMed

Shi, Chung-Sheng; Li, Jhy-Ming; Chin, Chih-Chien; Kuo, Yi-Hung; Lee, Ying-Ray; Huang, Yun-Ching

2017-03-01

Evodiamine, an indole alkaloid derived from Evodia rutaecarpa, exhibits pharmacological activities including vasodilatation, analgesia, anti-cardiovascular disease, anti-Alzheimer's disease, anti-inflammation, and anti-tumor activity. This study analyzes the anti-tumor effects of evodiamine on cellular growth, tumorigenesis, cell cycle and apoptosis induction of human urothelial cell carcinoma (UCC) cells. The present study showed that evodiamine significantly inhibited the proliferation of UCC cells in a dose- and time-dependent manner. Also, evodiamine suppressed the tumorigenesis of UCC cells in vitro. Moreover, evodiamine caused G 2 /M cell-cycle arrest and induced caspase-dependent apoptosis in UCC cells. Finally, we demonstrated that evodiamine exhibits better cytotoxic than 5-fluorouracil, a clinical chemotherapeutic drug, for UCC cells. Evodiamine induces growth inhibition, tumorigenesis suppression, cell-cycle arrest, and apoptosis induction in human UCC cells. Therefore, this agent displays a therapeutic potential for treating human UCC cells and is worthy for further investigation. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Human Cytomegalovirus-Encoded miR-US25-1 Aggravates the Oxidised Low Density Lipoprotein-Induced Apoptosis of Endothelial Cells

PubMed Central

Fan, Jianmin; Zhang, Wen; Liu, Qiming

2014-01-01

Human cytomegalovirus (HCMV) infection is linked to the development and severity of the cardiovascular disease atherosclerosis; however, there is little known about the promotion of atherosclerosis. miR-US25-1 is one of HCMV-encoded miRNAs and targets cellular genes that are essential for virus growth to control the life cycle of the virus and host cells. The prominent regulation on cell cycle genes of the miR-US25-1 attracts us to explore its role in the atherosclerosis promotion. It was indicated that miR-US25-1 level was upregulated in subjects or in endothelial cells with HCMV infection; and the miR-US25-1 downregulated the expression of BRCC 3 by targeting the 5′ UTR of BRCC 3. And a miR-US25-1 mimics transfection could reduce the EAhy926 cell viability but did not induce apoptosis in EAhy926 cells. And what is more, miR-US25-1 mimicis transfection deteriorated the ox-LDL-induced apoptosis and aggravated the upregulation of apoptosis-associated molecules by oxidised low density lipoprotein (ox-LDL) in EAhy926 cells. And we have also confirmed the deregulation of BRCC 3 expression by miR-US25-1 by targeting the 5′ UTR of it. Given the vital role of BRCC 3 in DNA damage repairing, we speculated that the targeting inhibition of BRCC 3 by miR-US25-1 may contribute to the aggravation of ox-LDL-promoted apoptosis of endothelial EAhy926 cells. PMID:24895586

Amoebal Endosymbiont Protochlamydia Induces Apoptosis to Human Immortal HEp-2 Cells

PubMed Central

Ito, Atsushi; Matsuo, Junji; Nakamura, Shinji; Yoshida, Asahi; Okude, Miho; Hayashi, Yasuhiro; Sakai, Haruna; Yoshida, Mitsutaka; Takahashi, Kaori; Yamaguchi, Hiroyuki

2012-01-01

Protochlamydia, an environmental chlamydia and obligate amoebal endosymbiotic bacterium, evolved to survive within protist hosts, such as Acanthamobae, 700 million years ago. However, these bacteria do not live in vertebrates, including humans. This raises the possibility that interactions between Protochlamydia and human cells could induce a novel cytopathic effect, leading to new insights into host-parasite relationships. Therefore, we studied the effect of Protochlamydia on the survival of human immortal cell line, HEp-2 cells and primary peripheral blood mononuclear cells (PBMC). Using mainly 4′,6-diamidino-2-phenylindole staining, fluorescent in situ hybridization, transmission electron microscopy, and also TUNEL and Transwell assays, we demonstrated that the Protochlamydia induced apoptosis in HEp-2 cells. The attachment of viable bacterial cells, but not an increase of bacterial infectious progenies within the cells, was required for the apoptosis. Other chlamydiae [Parachlamydia acanthamoebae and Chlamydia trachomatis (serovars D and L2)] did not induce the same phenomena, indicating that the observed apoptosis may be specific to the Protochlamydia. Furthermore, the bacteria had no effect on the survival of primary PBMCs collected from five volunteers, regardless of activation. We concluded that Protochlamydia induces apoptosis in human-immortal HEp-2 cells and that this endosymbiont could potentially be used as a biological tool for the elucidation of novel host-parasite relationships. PMID:22276171

Amoebal endosymbiont Protochlamydia induces apoptosis to human immortal HEp-2 cells.

PubMed

Ito, Atsushi; Matsuo, Junji; Nakamura, Shinji; Yoshida, Asahi; Okude, Miho; Hayashi, Yasuhiro; Sakai, Haruna; Yoshida, Mitsutaka; Takahashi, Kaori; Yamaguchi, Hiroyuki

2012-01-01

Protochlamydia, an environmental chlamydia and obligate amoebal endosymbiotic bacterium, evolved to survive within protist hosts, such as Acanthamobae, 700 million years ago. However, these bacteria do not live in vertebrates, including humans. This raises the possibility that interactions between Protochlamydia and human cells could induce a novel cytopathic effect, leading to new insights into host-parasite relationships. Therefore, we studied the effect of Protochlamydia on the survival of human immortal cell line, HEp-2 cells and primary peripheral blood mononuclear cells (PBMC). Using mainly 4',6-diamidino-2-phenylindole staining, fluorescent in situ hybridization, transmission electron microscopy, and also TUNEL and Transwell assays, we demonstrated that the Protochlamydia induced apoptosis in HEp-2 cells. The attachment of viable bacterial cells, but not an increase of bacterial infectious progenies within the cells, was required for the apoptosis. Other chlamydiae [Parachlamydia acanthamoebae and Chlamydia trachomatis (serovars D and L2)] did not induce the same phenomena, indicating that the observed apoptosis may be specific to the Protochlamydia. Furthermore, the bacteria had no effect on the survival of primary PBMCs collected from five volunteers, regardless of activation. We concluded that Protochlamydia induces apoptosis in human-immortal HEp-2 cells and that this endosymbiont could potentially be used as a biological tool for the elucidation of novel host-parasite relationships.

Thymoquinone Induces Cell Death in Human Squamous Carcinoma Cells via Caspase Activation-Dependent Apoptosis and LC3-II Activation-Dependent Autophagy

PubMed Central

Yu, Cheng-Chia; Lai, Yi-Yeh; Chen, Pei-Ni

2014-01-01

Background Thymoquinone (TQ), an active component of Nigella sativa or black cumin, elicits cytotoxic effects on various cancer cell lines. However, the anti-cancer effects of TQ on head and neck squamous cell carcinoma (HNSCC) remain unclear. Methodology/Principal Findings In this study, TQ elicited a strong cytotoxic effect on SASVO3, a highly malignant HNSCC cell line. The mechanisms of this cytotoxic effect were concentration dependent. TQ also induced apoptotic cell death in SASVO3 cells as indicated by an increase in Bax expression and caspase-9 activation. Apoptosis was possibly caspase-9 dependent because the exposure of cells to a caspase-9 inhibitor partially prevented cell death. The exposed cells also showed increased levels of autophagic vacuoles and LC3-II proteins, which are specific autophagy markers. Cell viability assay results further revealed that bafilomycin-A1, an autophagy inhibitor, enhanced TQ cytotoxicity; by comparison, Annexin V and propidium-iodide staining assay results showed that this inhibitor did not promote apoptosis. TQ treatment also increased the accumulation of autophagosomes. Using a lentivirus-shRNA system for LC3 silencing, we found that cell viability was eradicated in autophagy-defective cells. An in vivo BALB/c nude mouse xenograft model further showed that TQ administered by oral gavage reduced tumor growth via induced autophagy and apoptosis. Conclusions These findings indicated that TQ induced cell death in oral cancer cells via two distinct anti-neoplastic activities that can induce apoptosis and autophagy. Therefore, TQ is a promising candidate in phytochemical-based, mechanistic, and pathway-targeted cancer prevention strategies. PMID:25000169

Wogonin induces cross-regulation between autophagy and apoptosis via a variety of Akt pathway in human nasopharyngeal carcinoma cells.

PubMed

Chow, Shu-Er; Chen, Yu-Wen; Liang, Chi-Ang; Huang, Yao-Kuan; Wang, Jong-Shyan

2012-11-01

Autophagy as well as apoptosis is an emerging target for cancer therapy. Wogonin, a flavonoid compound derived from the traditional Chinese medicine of Huang-Qin, has anticancer activity in many cancer cells including human nasopharyngeal carcinoma (NPC). However, the involvement of autophagy in the wogonin-induced apoptosis of NPC cells was still uninvestigated. In this study, we found wogonin-induced autophagy had interference on the process of apoptosis. Wogonin-induced autophagy formation evidenced by LC3 I/II cleavage, acridine orange (AO)-stained vacuoles and the autophagosome/autolysosome images of TEM analysis. Activation of autophagy with rapamycin resulted in increased wogonin-mediated autophagy via inhibition of mTOR/P70S6K pathway. The functional relevance of autophagy in the antitumor activity was investigated by annexin V-positive stained cells and PARP cleavage. Induction of autophagy by rapamycin ameliorated the wogonin-mediated apoptosis, whereas inhibition of autophagy by 3-methyladenine (3-MA) or bafilomycin A1 increased the apoptotic effect. Interestingly, this study also found, in addition the mTOR/P70S6K pathway, wogonin also inhibited Raf/ERK pathway, a variety of Akt pathways. Inactivation of PI(3) K/Akt by their inhibitors significantly induced apoptosis and markedly sensitized the NPC cells to wogonin-induced apoptosis. This anticancer effect of Akt was further confirmed by SH6, a specific inhibitor of Akt. Importantly, inactivation of its downstream molecule ERK by PD98059, a MEK inhibitor, also induced apoptosis. This study indicated wogonin-induced both autophagy and apoptosis through a variety of Akt pathways and suggested modulation of autophagy might provide profoundly the potential therapeutic effect. Copyright © 2012 Wiley Periodicals, Inc.

Mitochondria-targeted platinum(II) complexes induce apoptosis-dependent autophagic cell death mediated by ER-stress in A549 cancer cells.

PubMed

Wang, Feng-Yang; Tang, Xiao-Ming; Wang, Xia; Huang, Ke-Bin; Feng, Hai-Wen; Chen, Zhen-Feng; Liu, You-Nian; Liang, Hong

2018-06-09

Agents with multiple modes of tumor cell death can be effective chemotherapeutic drugs. One example of a bimodal chemotherapeutic approach is an agent that can induce both apoptosis and autophagic death. Thus far, no clinical anticancer drug has been shown to simultaneously induce both these pathways. Mono-functional platinum complexes are potent anticancer drug candidates which act through mechanisms distinct from cisplatin. Here, we describe the synthesis and characterize of two mono-functional platinum complexes containing 8-substituted quinoline derivatives as ligands, [PtL 1 Cl]Cl [L 1  = (Z)-1-(pyridin-2-yl)-N-(quinolin-8-ylmethylene) methanamine] (Mon-Pt-1) and [PtL 2 Cl]Cl [L 2  = (Z)-2-(pyridin-2-yl)-N-(quinolin-8-ylmethylene) ethanamine] (Mon-Pt-2). In comparison to cisplatin, Mon-Pt-2 exhibited a greater in vitro cytotoxicity, was more effective in resistant cells and elicited a better anticancer effect. Mechanistic experiments indicate that Mon-Pt-2 mainly accumulates in mitochondria, and stimulates significant TrxR inhibition ROS release and an ER stress response, mediated by mitochondrial dysfunction, ultimately resulting in a simultaneous induction of apoptosis and autophagy. Importantly, compared to cisplatin, Mon-Pt-2 exhibits lower acute toxicity and better anticancer activity in a murine tumor model. To the best of our knowledge, Mon-Pt-2 is the first mono-functional platinum complex inducing pro-death autophagy and apoptosis of cancer cells. Copyright © 2018 The Authors. Published by Elsevier Masson SAS.. All rights reserved.

The construction of the multifunctional targeting ursolic acids liposomes and its apoptosis effects to C6 glioma stem cells

PubMed Central

Ying, Xue; Wang, Yahua; Xu, Haolun; Li, Xia; Yan, Helu; Tang, Hui; Wen, Chen; Li, Yingchun

2017-01-01

Brain gliomas, one of the most fatal tumors to human, severely threat the health and life of human. They are capable of extremely strong invasion ability. And invasive glioma cells could rapidly penetrate into normal brain tissues and break them. We prepared a kind of functional liposomes, which could be transported acrossing the blood-brain barrier (BBB) and afterwards induce the apoptosis of glioma stem cells. In this research, we chose ursolic acids (UA) as an anti-cancer drug to inhibit the growth of C6 glioma cells, while epigallocatechin 3-gallate(EGCG) as the agent that could induce the apoptosis of C6 glioma stem cells. With the targeting ability of MAN, the liposomes could be delivered through the BBB and finally were concentrated on the brain gliomas. Cell experiments in vitro demonstrated that the functional liposomes were able to significantly enhance the anti-cancer effects of the drugs due to promoting the apoptosis and endocytosis effects of C6 glioma cells and C6 glioma stem cells at the same time. Furthermore, the evaluations through animal models showed that the drugs could obviously prolong the survival period of brain glioma-bearing mice and inhibit the tumor growth. Consequently, multifunctional targeting ursolic acids liposomes could potentially improve the therapeutic effects on C6 glioma cells and C6 glioma stem cells. PMID:28969057

Expression of the p53 target CDIP correlates with sensitivity to TNF-alpha induced apoptosis in cancer cells

PubMed Central

Brown-Endres, Lauren; Schoenfeld, David; Tian, Fang; Kim, Hyung-Gu; Namba, Takushi; Muñoz-Fontela, César; Mandinova, Anna; Aaronson, Stuart A.; Lee, Sam W.

2012-01-01

TNFα is a pleiotropic cytokine that signals for both survival and apoptotic cell fates. It is still unclear that the dual role of TNFα can be regulated in cancer cells. We previously described an apoptotic pathway involving p53→CDIP→TNFα that was activated in response to genotoxic stress. This pathway operated in the presence of JNK activation; therefore, we postulated that CDIP itself could sensitize cells to a TNFα apoptotic cell fate, survival or death. We show that CDIP mediates sensitivity to TNFα-induced apoptosis, and that cancer cells with endogenous CDIP expression are inherently sensitive to the growth suppressive effects of TNFα in vitro and in vivo. Thus, CDIP expression correlates with sensitivity of cancer cells with TNFα, and CDIP appears to be a regulator of the p53-mediated death versus survival response of cells to TNFα. This CDIP-mediated sensitivity to TNFα-induced apoptosis favors pro-over anti-apoptotic program in cancer cells and CDIP may serve as a predictive biomarker for such sensitivity. PMID:22549949

Apoptosis of Hepatocellular Carcinoma Cells Induced by Nanoencapsulated Polysaccharides Extracted from Antrodia Camphorata

PubMed Central

Chang, Ke Liang B.; Kong, Zwe-Ling

2015-01-01

Antrodia camphorata is a well-known medicinal mushroom in Taiwan and has been studied for decades, especially with focus on anti-cancer activity. Polysaccharides are the major bioactive compounds reported with anti-cancer activity, but the debates on how they target cells still remain. Research addressing the encapsulation of polysaccharides from A. camphorata extract (ACE) to enhance anti-cancer activity is rare. In this study, ACE polysaccharides were nano-encapsulated in chitosan-silica and silica (expressed as ACE/CS and ACE/S, respectively) to evaluate the apoptosis effect on a hepatoma cell line (Hep G2). The results showed that ACE polysaccharides, ACE/CS and ACE/S all could damage the Hep G2 cell membrane and cause cell death, especially in the ACE/CS group. In apoptosis assays, DNA fragmentation and sub-G1 phase populations were increased, and the mitochondrial membrane potential decreased significantly after treatments. ACE/CS and ACE/S could also increase reactive oxygen species (ROS) generation, induce Fas/APO-1 (apoptosis antigen 1) expression and elevate the proteolytic activities of caspase-3, caspase-8 and caspase-9 in Hep G2 cells. Unsurprisingly, ACE/CS induced a similar apoptosis mechanism at a lower dosage (ACE polysaccharides = 13.2 μg/mL) than those of ACE/S (ACE polysaccharides = 21.2 μg/mL) and ACE polysaccharides (25 μg/mL). Therefore, the encapsulation of ACE polysaccharides by chitosan-silica nanoparticles may provide a viable approach for enhancing anti-tumor efficacy in liver cancer cells. PMID:26327534

Bupivacaine-induced apoptosis independently of WDR35 expression in mouse neuroblastoma Neuro2a cells

PubMed Central

2012-01-01

Background Bupivacaine-induced neurotoxicity has been shown to occur through apoptosis. Recently, bupivacaine was shown to elicit reactive oxygen species (ROS) production and induce apoptosis accompanied by activation of p38 mitogen-activated protein kinase (MAPK) in a human neuroblastoma cell line. We have reported that WDR35, a WD40-repeat protein, may mediate apoptosis through caspase-3 activation. The present study was undertaken to test whether bupivacaine induces apoptosis in mouse neuroblastoma Neuro2a cells and to determine whether ROS, p38 MAPK, and WDR35 are involved. Results Our results showed that bupivacaine induced ROS generation and p38 MAPK activation in Neuro2a cells, resulting in apoptosis. Bupivacaine also increased WDR35 expression in a dose- and time-dependent manner. Hydrogen peroxide (H2O2) also increased WDR35 expression in Neuro2a cells. Antioxidant (EUK-8) and p38 MAPK inhibitor (SB202190) treatment attenuated the increase in caspase-3 activity, cell death and WDR35 expression induced by bupivacaine or H2O2. Although transfection of Neuro2a cells with WDR35 siRNA attenuated the bupivacaine- or H2O2-induced increase in expression of WDR35 mRNA and protein, in contrast to our previous studies, it did not inhibit the increase in caspase-3 activity in bupivacaine- or H2O2-treated cells. Conclusions In summary, our results indicated that bupivacaine induced apoptosis in Neuro2a cells. Bupivacaine induced ROS generation and p38 MAPK activation, resulting in an increase in WDR35 expression, in these cells. However, the increase in WDR35 expression may not be essential for the bupivacaine-induced apoptosis in Neuro2a cells. These results may suggest the existence of another mechanism of bupivacaine-induced apoptosis independent from WDR35 expression in Neuro2a cells. PMID:23227925

Deficiency in methionine, tryptophan, isoleucine, or choline induces apoptosis in cultured cells.

PubMed

Yen, Chi-Liang E; Mar, Mei-Heng; Craciunescu, Corneliu N; Edwards, Lloyd J; Zeisel, Steven H

2002-07-01

Cells in culture die by apoptosis when deprived of the essential nutrient choline. We now report that cells (both proliferating PC12 cells and postmitotic neurons isolated from fetal rat brains) undergo apoptosis when deprived of other individual essential nutrients (methionine, tryptophan or isoleucine). In PC12 cells, deficiencies of each nutrient independently led to ceramide accumulation and to caspase activation, both recognized signals of several apoptotic pathways. A similar profile of caspases was activated in PC12 cells deprived of choline, methionine, tryptophan or isoleucine. More than one caspase was involved and these caspases appeared to transmit parallel signals for apoptosis induction because only broad-spectrum caspase inhibitors, but not inhibitors for specific individual caspases inhibited apoptosis in choline- or methionine-deprived cells. The induction of these caspase-dependent apoptosis pathways likely did not involve the same upstream signals. Choline deficiency perturbed choline metabolism but did not affect protein synthesis, whereas amino acid deficiencies inhibited protein synthesis but did not perturb choline metabolism. In addition, a subclone of PC12 cells that was resistant to choline deficiency-induced apoptosis was not resistant to tryptophan deficiency-induced apoptosis. These observations suggest that deficiency of each studied nutrient activates different pathways for signaling apoptosis that ultimately converge on a common execution pathway.

Lingonberry anthocyanins protect cardiac cells from oxidative-stress-induced apoptosis.

PubMed

Isaak, Cara K; Petkau, Jay C; Blewett, Heather; O, Karmin; Siow, Yaw L

2017-08-01

Lingonberry grown in northern Manitoba, Canada, contains exceptionally high levels of anthocyanins and other polyphenols. Previous studies from our lab have shown that lingonberry anthocyanins can protect H9c2 cells from ischemia-reperfusion injury and anthocyanin-rich diets have been shown to be associated with decreased cardiovascular disease and mortality. Oxidative stress can impair function and trigger apoptosis in cardiomyocytes. This study investigated the protective effects of physiologically relevant doses of lingonberry extracts and pure anthocyanins against hydrogen-peroxide-induced cell death. Apoptosis and necrosis were detected in H9c2 cells after hydrogen peroxide treatment via flow cytometry using FLICA 660 caspase 3/7 combined with YO-PRO-1 and then confirmed with Hoechst staining and fluorescence microscopy. Each of the 3 major anthocyanins found in lingonberry (cyanidin-3-galactoside, cyanidin-3-glucoside, and cyanidin-3-arabinoside) was protective against hydrogen-peroxide-induced apoptosis in H9c2 cells at 10 ng·mL -1 (20 nmol·L -1 ) and restored the number of viable cells to match the control group. A combination of the 3 anthocyanins was also protective and a lingonberry extract tested at 3 concentrations produced a dose-dependent protective effect. Lingonberry anthocyanins protected cardiac cells from oxidative-stress-induced apoptosis and may have cardioprotective effects as a dietary modification.

Cetuximab enhances cisplatin-induced endoplasmic reticulum stress-associated apoptosis in laryngeal squamous cell carcinoma cells by inhibiting expression of TXNDC5.

PubMed

Peng, Fusen; Zhang, Hailin; Du, Youhong; Tan, Pingqing

2018-03-01

Cisplatin and cetuximab, an anti‑epidermal growth factor receptor (EGFR) monoclonal humanized antibody, have been used for treatment of laryngeal squamous cell carcinoma (LSCC). It has been demonstrated that cisplatin and inhibition of EGFR signaling may induce endoplasmic reticulum (ER) stress‑associated apoptosis. However, ER protein thioredoxin domain‑containing protein 5 (TXNDC5) reportedly protects cells from ER stress‑associated apoptosis. The present study investigated the interaction between cisplatin, cetuximab and TXNDC5 on ER stress‑associated apoptosis in LSCC cells. AMC‑HN‑8 human LSCC cells with or without TXNDC5 overexpression or knockdown were treated with cisplatin (5, 10, 20 and 40 µM) and/or cetuximab (10, 50, 100 and 150 µg/ml), for 12, 24, 36 and 48 h. Cisplatin and cetuximab concentration‑ and time‑dependently increased and decreased the expression of TXNDC5 in AMC‑HN‑8 cells, respectively. Knockdown of TXNDC5 markedly augmented cisplatin‑induced levels of CCAAT/enhancer‑binding protein homologous protein (CHOP), caspase‑3 activity and apoptosis; while overexpression of TXNDC5 largely eliminated cetuximab‑induced levels of CHOP, caspase‑3 activity and apoptosis. Cisplatin and cetuximab demonstrated a combinatorial effect on increasing the levels of CHOP, caspase‑3 activity and apoptosis, which was largely eliminated by overexpression of TXNDC5 or a reactive oxygen species (ROS) scavenger/antagonist. In addition, promoter/luciferase reporter assays revealed that cisplatin and cetuximab regulated the expression of TXNDC5 at the gene transcription/promoter level. In conclusion, the findings suggested that ER stress‑associated apoptosis is a major mechanism underlying the apoptotic effect of cisplatin and cetuximab on LSCC cells; cetuximab enhanced cisplatin‑induced ER stress‑associated apoptosis in LSCC cells largely by inhibiting the expression of TXNDC5 and thereby increasing ROS production

Berberine Induces Caspase-Independent Cell Death in Colon Tumor Cells through Activation of Apoptosis-Inducing Factor

PubMed Central

Wang, Lihong; Liu, Liping; Shi, Yan; Cao, Hanwei; Chaturvedi, Rupesh; Calcutt, M. Wade; Hu, Tianhui; Ren, Xiubao; Wilson, Keith T.; Polk, D. Brent; Yan, Fang

2012-01-01

Berberine, an isoquinoline alkaloid derived from plants, is a traditional medicine for treating bacterial diarrhea and intestinal parasite infections. Although berberine has recently been shown to suppress growth of several tumor cell lines, information regarding the effect of berberine on colon tumor growth is limited. Here, we investigated the mechanisms underlying the effects of berberine on regulating the fate of colon tumor cells, specifically the mouse immorto-Min colonic epithelial (IMCE) cells carrying the Apc min mutation, and of normal colon epithelial cells, namely young adult mouse colonic epithelium (YAMC) cells. Berberine decreased colon tumor colony formation in agar, and induced cell death and LDH release in a time- and concentration-dependent manner in IMCE cells. In contrast, YAMC cells were not sensitive to berberine-induced cell death. Berberine did not stimulate caspase activation, and PARP cleavage and berberine-induced cell death were not affected by a caspase inhibitor in IMCE cells. Rather, berberine stimulated a caspase-independent cell death mediator, apoptosis-inducing factor (AIF) release from mitochondria and nuclear translocation in a ROS production-dependent manner. Amelioration of berberine-stimulated ROS production or suppression of AIF expression blocked berberine-induced cell death and LDH release in IMCE cells. Furthermore, two targets of ROS production in cells, cathepsin B release from lysosomes and PARP activation were induced by berberine. Blockage of either of these pathways decreased berberine-induced AIF activation and cell death in IMCE cells. Thus, berberine-stimulated ROS production leads to cathepsin B release and PARP activation-dependent AIF activation, resulting in caspase-independent cell death in colon tumor cells. Notably, normal colon epithelial cells are less susceptible to berberine-induced cell death, which suggests the specific inhibitory effects of berberine on colon tumor cell growth. PMID:22574158

Suppression of murine collagen-induced arthritis by targeted apoptosis of synovial neovasculature

PubMed Central

Gerlag, Danielle M; Borges, Eric; Tak, Paul P; Ellerby, H Michael; Bredesen, Dale E; Pasqualini, Renata; Ruoslahti, Erkki; Firestein, Gary S

2001-01-01

Because angiogenesis plays a major role in the perpetuation of inflammatory arthritis, we explored a method for selectively targeting and destroying new synovial blood vessels. Mice with collagen-induced arthritis were injected intravenously with phage expressing an RGD motif. In addition, the RGD peptide (RGD-4C) was covalently linked to a proapoptotic heptapeptide dimer, D(KLAKLAK)2, and was systemically administered to mice with collagen-induced arthritis. A phage displaying an RGD-containing cyclic peptide (RGD-4C) that binds selectively to the αvβ3 and αvβ5 integrins accumulated in inflamed synovium but not in normal synovium. Homing of RGD-4C phage to inflamed synovium was inhibited by co-administration of soluble RGD-4C. Intravenous injections of the RGD-4C–D(KLAKLAK)2 chimeric peptide significantly decreased clinical arthritis and increased apoptosis of synovial blood vessels, whereas treatment with vehicle or uncoupled mixture of the RGD-4C and the untargeted proapoptotic peptide had no effect. Targeted apoptosis of synovial neovasculature can induce apoptosis and suppress clinical arthritis. This form of therapy has potential utility in the treatment of inflammatory arthritis. PMID:11714389

Protective role of Osthole on myocardial cell apoptosis induced by doxorubicin in rats.

PubMed

Xu, Hongdang; Han, Yu; Zhang, Mengwei; Yan, Min; Gao, Chuanyu

2015-01-01

To explore the effect of Osthole on protecting myocardial cell apoptosis induced by doxorubicin during cardiac failure in rats. Myocardial cells isolated from the newborn SD rats were separated into three groups: cells treated with 1 μmol doxorubicin, cells treated with Osthole at three concentrations of 10, 20, and 40 μmol, cells treated neither with Osthole nor with doxorubicin were the control groups. Consequently, cell apoptosis of myocardial cells in each group was analyzed using TUNEL assay. Also, expressions of oxidase, NADPH, and ROS in myocardial cells were analyzed using different biological methods. Moreover, expressions of cell apoptosis associated proteins were analyzed using Western blotting. Compared with the controls, the results showed that cells received Osthole and doxorubicin treatments performed high percentage of cell apoptosis, suggesting that Osthole could anesis myocardial cell apoptosis induced by doxorubicin (P<0.05). Osthole of 10 μmol depressed the expressions of cell apoptosis associated proteins including Caspase-3 and Cytc, and enhancing expression of Bcl-XL expression (P<0.05). Osthole of 20 μmol significantly decreased the generation of intracellar superoxidase, NADPH, and NADPH activity in myocardial cells treated with doxorubicin (P<0.05). Moreover, Osthole of 20 μmol could significantly increase phosphorylated elF2α level in cells. Our study suggested that Osthole may play a protective role in suppressing myocardial apoptosis induced by doxorubicin through inhibiting NADPH and superoxidase production and downstream phosphorylated elF2α.

Protective role of Osthole on myocardial cell apoptosis induced by doxorubicin in rats

PubMed Central

Xu, Hongdang; Han, Yu; Zhang, Mengwei; Yan, Min; Gao, Chuanyu

2015-01-01

Objective: To explore the effect of Osthole on protecting myocardial cell apoptosis induced by doxorubicin during cardiac failure in rats. Methods: Myocardial cells isolated from the newborn SD rats were separated into three groups: cells treated with 1 μmol doxorubicin, cells treated with Osthole at three concentrations of 10, 20, and 40 μmol, cells treated neither with Osthole nor with doxorubicin were the control groups. Consequently, cell apoptosis of myocardial cells in each group was analyzed using TUNEL assay. Also, expressions of oxidase, NADPH, and ROS in myocardial cells were analyzed using different biological methods. Moreover, expressions of cell apoptosis associated proteins were analyzed using Western blotting. Results: Compared with the controls, the results showed that cells received Osthole and doxorubicin treatments performed high percentage of cell apoptosis, suggesting that Osthole could anesis myocardial cell apoptosis induced by doxorubicin (P<0.05). Osthole of 10 μmol depressed the expressions of cell apoptosis associated proteins including Caspase-3 and Cytc, and enhancing expression of Bcl-XL expression (P<0.05). Osthole of 20 μmol significantly decreased the generation of intracellar superoxidase, NADPH, and NADPH activity in myocardial cells treated with doxorubicin (P<0.05). Moreover, Osthole of 20 μmol could significantly increase phosphorylated elF2α level in cells. Conclusion: Our study suggested that Osthole may play a protective role in suppressing myocardial apoptosis induced by doxorubicin through inhibiting NADPH and superoxidase production and downstream phosphorylated elF2α. PMID:26617794

Cuprous oxide nanoparticles selectively induce apoptosis of tumor cells

PubMed Central

Wang, Ye; Zi, Xiao-Yuan; Su, Juan; Zhang, Hong-Xia; Zhang, Xin-Rong; Zhu, Hai-Ying; Li, Jian-Xiu; Yin, Meng; Yang, Feng; Hu, Yi-Ping

2012-01-01

In the rapid development of nanoscience and nanotechnology, many researchers have discovered that metal oxide nanoparticles have very useful pharmacological effects. Cuprous oxide nanoparticles (CONPs) can selectively induce apoptosis and suppress the proliferation of tumor cells, showing great potential as a clinical cancer therapy. Treatment with CONPs caused a G1/G0 cell cycle arrest in tumor cells. Furthermore, CONPs enclosed in vesicles entered, or were taken up by mitochondria, which damaged their membranes, thereby inducing apoptosis. CONPs can also produce reactive oxygen species (ROS) and initiate lipid peroxidation of the liposomal membrane, thereby regulating many signaling pathways and influencing the vital movements of cells. Our results demonstrate that CONPs have selective cytotoxicity towards tumor cells, and indicate that CONPs might be a potential nanomedicine for cancer therapy. PMID:22679374

Low-level laser therapy prevents endothelial cells from TNF-α/cycloheximide-induced apoptosis.

PubMed

Chu, Yu-Hsiu; Chen, Shu-Ya; Hsieh, Yueh-Ling; Teng, Yi-Hsien; Cheng, Yu-Jung

2018-02-01

Low-level laser therapy (LLLT), widely used in physiotherapy, has been known to enhance wound healing and stimulate cell proliferation, including fibroblast and endothelial cells. Applying LLLT can increase cell proliferation in many kinds of cells including fibroblasts and endothelial cells. However, the protective mechanisms of LLLT on endothelial apoptosis remain unclear. We hypothesized LLLT can protect endothelial cells from inflammation-induced apoptosis. Human endothelial cell line, EA.hy926 cells, and TNF-α/cycloheximide (TNF/CHX) were used to explore the protective effects of LLLT (660 nm) on inflammation-induced endothelial apoptosis. Cell viability, apoptosis, caspase-3/7/8/9 activity, MAPKs signaling, NF-κB activity, and inducible/endothelial nitric oxide synthase (iNOS/eNOS) expression were measured. Our results showed that LLLT increased EA.hy926 cell proliferation, attenuated the TNF/CHX-induced apoptosis, and reduced the TNF/CHX-mediated caspase-3/7/8/9 activation. In addition, LLLT increased ERK MAPK phosphorylation and suppressed the TNF/CHX-increased p38 MAPK, JNK, IKK phosphorylation, NF-κB translocation, and iNOS expression. The caspases-3 cleavage and cell death were not increased in cells treating with ERK inhibitor U0126, which implicated that ERK is not to be responsible for the protective effects of LLLT. After treating with p38 mitogen-activated protein kinase (MAPK) activator, the protection of LLLT in cell apoptosis was no longer existed, showing that LLLT protected the endothelial cells by suppressing p38 MAPK signaling. Our results provide a new insight into the possible molecular mechanisms in which LLLT protects against inflammatory-induced endothelial dysfunction.

Paclitaxel Induces Apoptosis in Breast Cancer Cells through Different Calcium—Regulating Mechanisms Depending on External Calcium Conditions

PubMed Central

Pan, Zhi; Avila, Andrew; Gollahon, Lauren

2014-01-01

Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis. PMID:24549172

microRNA-340 induces apoptosis by downregulation of BAG3 in ovarian cancer SKOV3 cells.

PubMed

Qu, Fei; Wang, Xiufen

2017-08-01

Aberrant expression of miR-340 has been found in several kinds of cancers including ovarian cancer. Pro-apoptotic and anti-metastasis roles of miR-340 in ovarian cancer have also been reported; however, the underling molecular mechanisms by which miR-340 suppresses ovarian cancer are still unclear. This study focused on the role and molecular mechanism of miR-340 in ovarian cancer. Human ovarian carcinoma SKOV3 cells were used and transfected with miR-340 mimic, miR-340 inhibitor and their correspondingly negative controls (mimic control and inhibitor control). Thereafter, cell viability, apoptosis, and the expressions of apoptosis-associated factors and BAG3 were respectively assessed by MTT assay, flow cytometry, qRT-PCR and Western blotting. SKOV3 cells were then co-transfected with miR-340 inhibitor and BAG3 targeted siRNA, then cell viability, apoptosis and the expression of apoptosis-associated factors were retested. Besides, the expressions of main factors in PI3K/AKT pathway were detected. Overexpression of miR-340 suppressed BAG3 cells viability (P < 0.05), but improved apoptosis (P < 0.001). BAG3 was negatively regulated by miR-340 (P < 0.05 or P < 0.01). BAG3 silence significantly induced cell apoptosis (P < 0.001), and abolished miR-340 suppression-induced increase in cell viability (P < 0.001). Besides, BAG3 silence abolished miR-340 suppression-induced activation of PI3K and AKT. This study revealed the tumor suppressive role of miR-340 in SKOV3 cells by negative regulation of BAG3. PI3K/AKT pathway might be involved in the regulation of miR-340 and BAG3.

Effects of p53 on aldosterone-induced mesangial cell apoptosis in vivo and in vitro.

PubMed

Shi, Huimin; Zhang, Aiqing; He, Yanfang; Yang, Min; Gan, Weihua

2016-06-01

Aldosterone (ALD) is a well‑known hormone, which may initiate renal injury by inducing mesangial cell (MC) injury in chronic kidney disease (CKD); however, the molecular mechanism remains unknown. The aim of the present study was to investigate the effects of p53 on ALD‑induced MC apoptosis and elucidate the underlying molecular mechanism. For the in vivo studies, rats were randomly assigned to receive normal saline or ALD for 4 weeks. The ratio of MC apoptosis was analysed by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. In addition, the expression level and localisation of p53, a well-known cell apoptosis-associated key protein, were detected by immunofluorescence. For the in vitro studies, rat MCs were incubated in medium containing either buffer (control) or ALD (10‑6 M) for 24 h. The cell apoptosis ratio was assessed by flow cytometry, and the expression level of p53 was assessed by reverse transcription quantitative polymerase chain reaction and western blotting. In order to confirm the role of p53 in ALD‑regulated cell apoptosis, a rescue experiment was performed using targeted small interfering (si)RNA to downregulate the expression of p53. The ALD‑treated rats exhibited greater numbers of TUNEL‑positive MCs and higher expression levels of p53 when compared with the control group. Furthermore, the ratio of MC apoptosis and the p53 expression level were significantly increased following ALD exposure, compared with the control group. Additionally, in the rescue experiment, the effects of ALD on MC were blocked by downregulating the expression level of p53 in MCs. The present study hypothesized that ALD may directly contribute to the occurrence of MC apoptosis via p53, which may participate in ALD-induced renal injury.

Bcl-2 silencing attenuates hypoxia-induced apoptosis resistance in pulmonary microvascular endothelial cells.

PubMed

Cao, Yongmei; Jiang, Zhen; Zeng, Zhen; Liu, Yujing; Gu, Yuchun; Ji, Yingying; Zhao, Yupeng; Li, Yingchuan

2016-01-01

Pulmonary arterial hypertension (PAH) is a life-threatening disorder that ultimately causes heart failure. While the underlying causes of this condition are not well understood, previous studies suggest that the anti-apoptotic nature of pulmonary microvascular endothelial cells (PMVECs) in hypoxic environments contributes to PAH pathogenesis. In this study, we focus on the contribution of Bcl-2 and hypoxia response element (HRE) to apoptosis-resistant endothelial cells and investigate the mechanism. PMVECs obtained from either normal rats or apoptosis-resistant PMVECs obtained from PAH rats were transduced with recombinant lentiviral vectors carrying either Bcl-2-shRNA or HRE combined Bcl-2-shRNA, and then cultured these cells for 24 h under hypoxic (5% O2) or normoxic (21% O2) conditions. In normal PMVECs, Bcl-2-shRNA or HRE combined with Bcl-2-shRNA transduction successfully decreased Bcl-2 expression, while increasing apoptosis as well as caspase-3 and P53 expression in a normoxic environment. In a hypoxic environment, the effects of Bcl-2-shRNA treatment on cell apoptosis, and on Bcl-2, caspase-3, P53 expression were significantly suppressed. Conversely, HRE activation combined with Bcl-2-shRNA transduction markedly enhanced cell apoptosis and upregulated caspase-3 and P53 expression, while decreasing Bcl-2 expression. Furthermore, in apoptosis-resistant PMVECs, HRE-mediated Bcl-2 silencing effectively enhanced cell apoptosis and caspase-3 activity. The apoptosis rate was significantly depressed when Lv-HRE-Bcl-2-shRNA was combined with Lv-P53-shRNA or Lv-caspase3-shRNA transduction in a hypoxic environment. These results suggest that HRE-mediated Bcl-2 inhibition can effectively attenuate hypoxia-induced apoptosis resistance in PMVECs by downregulating Bcl-2 expression and upregulating caspase-3 and P53 expression. This study therefore reveals critical insight into potential therapeutic targets for treating PAH.

Apoptosis inducing factor gene depletion inhibits zearalenone-induced cell death in a goat Leydig cell line.

PubMed

Yang, Diqi; Jiang, Tingting; Lin, Pengfei; Chen, Huatao; Wang, Lei; Wang, Nan; Zhao, Fan; Tang, Keqiong; Zhou, Dong; Wang, Aihua; Jin, Yaping

2017-01-01

Zearalenone (ZEA) is a contaminant of human food and animal feedstuffs that causes health hazards. However, the signal pathways underlying ZEA toxicity remain elusive. The aims of this study were to determine which pathways are involved in ZEA-induced cell death and investigate the effect of apoptosis inducing factor (AIF) on cell death during ZEA treatment in the immortalized goat Leydig cell line hTERT-GLC. This study showed that ZEA-induced cell death in hTERT-GLCs works via endoplasmic reticulum (ER) stress, the caspase-dependent pathway, the caspase-independent pathway and autophagy. Recombinant lentiviral vectors were constructed to silence AIF expression in hTERT-GLCs. Flow cytometry results showed that knockdown of AIF diminished ZEA-induced cell apoptosis in hTERT-GLCs. Furthermore, we found AIF depletion down-regulated phosphoIRE1α, GRP78, CHOP and promoted the switch of LC3-I to LC3-II. Therefore, ZEA induces cytotoxicity in hTERT-GLCs via different pathways, while AIF-mediated signaling plays a critical role in ZEA-induced cell death in hTERT-GLCs. Copyright © 2016 Elsevier Inc. All rights reserved.

Inducing cell death in vitro in cancer cells by targeted delivery of cytochrome c via a transferrin conjugate

PubMed Central

Delgado, Yamixa; Sharma, Rohit Kumar; Sharma, Shweta; Guzmán, Solimar Liz Ponce De León; Tinoco, Arthur D.; Griebenow, Kai

2018-01-01

One of the major drawbacks of many of the currently used cancer drugs are off-target effects. Targeted delivery is one method to minimize such unwanted and detrimental events. To actively target lung cancer cells, we have developed a conjugate of the apoptosis inducing protein cytochrome c with transferrin because the transferrin receptor is overexpressed by many rapidly dividing cancer cells. Cytochrome c and transferrin were cross-linked with a redox sensitive disulfide bond for the intra-cellular release of the protein upon endocytosis by the transferrin receptor. Confocal results demonstrated the cellular uptake of the cytochrome c-transferrin conjugate by transferrin receptor overexpressing A549 lung cancer cells. Localization studies further validated that this conjugate escaped the endosome. Additionally, an in vitro assay showed that the conjugate could induce apoptosis by activating caspase-3. The neo-conjugate not only maintained an IC50 value similar to the well known drug cisplatin (50 μM) in A549 cancer cells but also was nontoxic to the normal lung (MRC5) cells. Our neo-conjugate holds promise for future development to target cancers with enhanced transferrin receptor expression. PMID:29649293

TGEV nucleocapsid protein induces cell cycle arrest and apoptosis through activation of p53 signaling

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

Ding, Li; College of Life Sciences, Hainan Normal University, Haikou, Hainan 571158; Huang, Yong

2014-03-07

Highlights: • TGEV N protein reduces cell viability by inducing cell cycle arrest and apoptosis. • TGEV N protein induces cell cycle arrest and apoptosis by regulating p53 signaling. • TGEV N protein plays important roles in TGEV-induced cell cycle arrest and apoptosis. - Abstract: Our previous studies showed that TGEV infection could induce cell cycle arrest and apoptosis via activation of p53 signaling in cultured host cells. However, it is unclear which viral gene causes these effects. In this study, we investigated the effects of TGEV nucleocapsid (N) protein on PK-15 cells. We found that TGEV N protein suppressedmore » cell proliferation by causing cell cycle arrest at the S and G2/M phases and apoptosis. Characterization of various cellular proteins that are involved in regulating cell cycle progression demonstrated that the expression of N gene resulted in an accumulation of p53 and p21, which suppressed cyclin B1, cdc2 and cdk2 expression. Moreover, the expression of TGEV N gene promoted translocation of Bax to mitochondria, which in turn caused the release of cytochrome c, followed by activation of caspase-3, resulting in cell apoptosis in the transfected PK-15 cells following cell cycle arrest. Further studies showed that p53 inhibitor attenuated TGEV N protein induced cell cycle arrest at S and G2/M phases and apoptosis through reversing the expression changes of cdc2, cdk2 and cyclin B1 and the translocation changes of Bax and cytochrome c induced by TGEV N protein. Taken together, these results demonstrated that TGEV N protein might play an important role in TGEV infection-induced p53 activation and cell cycle arrest at the S and G2/M phases and apoptosis occurrence.« less

miR-29b suppresses CML cell proliferation and induces apoptosis via regulation of BCR/ABL1 protein

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

Li, Yajuan; Wang, Haixia; Tao, Kun

MicroRNAs (miRNAs) are small RNAs that regulate gene expression posttranscriptionally and are critical for many cellular pathways. Recent evidence has shown that aberrant miRNA expression profiles and unique miRNA signaling pathways are present in many cancers. Here, we demonstrate that miR-29b is markedly lower expressed in CML patient samples. Bioinformatics analysis reveals a conserved target site for miR-29b in the 3′-untranslated region (UTR) of ABL1. miR-29b significantly suppresses the activity of a luciferase reporter containing ABL1-3′UTR and this activity is not observed in cells transfected with mutated ABL1-3′UTR. Enforced expression of miR-29b in K562 cells inhibits cell growth and colonymore » formation ability thereby inducing apoptosis through cleavage of procaspase 3 and PARP. Furthermore, K562 cells transfected with a siRNA targeting ABL1 show similar growth and apoptosis phenotypes as cells overexpression of miR-29b. Collectively, our results suggest that miR-29b may function as a tumor suppressor by targeting ABL1 and BCR/ABL1. - Highlights: ► miR-29b expression was downregulated in CML patients. ► ABL1 was identified as a direct target gene of miR-29b. ► Enforced expression of miR-29b inhibits cell proliferation and induces apoptosis. ► miR-29b might be a therapeutic target to CML.« less

Mineral pitch induces apoptosis and inhibits proliferation via modulating reactive oxygen species in hepatic cancer cells.

PubMed

Pant, Kishor; Gupta, Parul; Damania, Preeti; Yadav, Ajay K; Gupta, Aanchal; Ashraf, Anam; Venugopal, Senthil K

2016-05-27

Mineral Pitch (MP) is a dark brown coloured humic matter originating from high altitude rocks. It is an Ayurvedic medicinal food, commonly used by the people of the Himalayan regions of Nepal and India for various body ailments. The Huh-7 cells were treated with different concentrations of MP for 24 h, and both apoptosis and proliferation was determined by the TUNEL and MTT assays respectively. The formation of ROS and nitric oxide was analysed by DCFH-DA and Griess reagent respectively. The expression of miRNA-21 and miRNA-22 were checked by the real time PCR. Effect of miRNA-22 on proliferation and c-myc was studied by over-expressing miRNA-22 premiRs in Huh-7 cells. We found that MP enhanced anti-cancer effects by inducing apoptosis and inhibiting proliferation. MP induced both ROS and NO, upon neutralizing them, there was a partial recovery of apoptosis and proliferation. MP also induced miRNA-22 expression, while miRNA-21 expression was inhibited. Over-expression of miRNA-22 resulted in a significant inhibition of proliferation. miRNA-22 directly targeted c-myc gene, thereby inhibited proliferation. These results clearly show that MP induces its anti-cancer activity by more than one pathway. The data clearly indicate that MP induced apoptosis via the production of ROS, and inhibited proliferation by inducing miRNA-22 and inhibiting miRNA-21 in Huh-7 cells.

Licochalcone C induces apoptosis via B-cell lymphoma 2 family proteins in T24 cells.

PubMed

Wang, Penglong; Yuan, Xuan; Wang, Yan; Zhao, Hong; Sun, Xiling; Zheng, Qiusheng

2015-11-01

The current study investigated the mechanisms by which licochalcone C induces apoptosis of T24 human malignant bladder cancer cells. Cell viability was evaluated using an MTT assay. Apoptosis was investigated using a morphological assay, flow cytometry and a caspase‑3 activity assay. Alterations in the gene expression levels of Bcl‑2 family members were measured by semi‑quantitative reverse transcription‑polymerase chain reaction assays. The protein levels of pro‑caspase‑3 and cleaved poly(ADP ribose) polymerase were measured using western blotting. The results indicated that licochalcone C induced T24 cell apoptosis in a concentration‑dependent manner. Licochalcone C treatment reduced the levels of the anti‑apoptotic mRNAs (Bcl‑2, Bcl‑w and Bcl‑XL) and increased expression of the pro‑apoptotic mRNAs (Bax and Bim). The Bcl‑2 family inhibitor (ABT‑737) reduced apoptosis induced by licochalcone C in T24 cells. The current study demonstrated that licochalcone C may be a potential adjuvant therapeutic agent for bladder cancer.

Combination of HDAC inhibitor TSA and silibinin induces cell cycle arrest and apoptosis by targeting survivin and cyclinB1/Cdk1 in pancreatic cancer cells.

PubMed

Feng, Wan; Cai, Dawei; Zhang, Bin; Lou, Guochun; Zou, Xiaoping

2015-08-01

Histone deacetylases (HDAC) are involved in diverse biological processes and therefore emerge as potential targets for pancreatic cancer. Silibinin, an active component of silymarin, is known to inhibit growth of pancreatic cancer in vivo and in vitro. Herein, we examined the cytotoxic effects of TSA in combination with silibinin and investigated the possible mechanism in two pancreatic cancer cell lines (Panc1 and Capan2). Our study found that combination treatment of HDAC inhibitor and silibinin exerted additive growth inhibitory effect on pancreatic cancer cell. Annexin V-FITC/PI staining and flow cytometry analysis demonstrated that combination therapy induced G2/M cell cycle arrest and apoptosis in Panc1and Capan2 cells. The induction of apoptosis was further confirmed by evaluating the activation of caspases. Moreover, treatment with TSA and silibinin resulted in a profound reduction in the expression of cyclinA2, cyclinB1/Cdk1 and survivin. Taken together, our study might indicate that the novel combination of HDAC inhibitor and silibinin could offer therapeutic potential against pancreatic cancer. Copyright © 2015. Published by Elsevier Masson SAS.

HAT1 induces lung cancer cell apoptosis via up regulating Fas.

PubMed

Han, Na; Shi, Lei; Guo, Qiuyun; Sun, Wei; Yu, Yang; Yang, Li; Zhang, Xiaoxi; Zhang, Mengxian

2017-10-27

The dysfunction of apoptosis is one of the factors contributing to lung cancer (LC) growth. Histone acetyltransferase HAT1 can up regulate cell apoptosis. This study aims to investigate the mechanism by which HAT1 induces LC cell (LCC) apoptosis via up regulating the expression of Fas. In this study, the surgically removed human LC tissues were collected. LCCs were isolated from the LC tissues and analyzed for the expression of HAT1 and Fas by RT-qPCR and Western blotting. We observed that the expression of Fas was negatively correlated with PAR2 in LCCs. Activation of PAR2 suppressed the expression of Fas in normal lung epithelial cells. The expression of HAT1 was lower and positively correlated with Fas expression and negatively correlated with PAR2 expression in LCCs. Activation of PAR2 suppressed Fas expression in lung epithelial cells via inhibiting HAT1. Restoration of HAT1 expression restored Fas expression in LCCs and induced LCC apoptosis. In conclusion, less expression of HAT1 in LCCs was associated with the pathogenesis of LC. Up regulation of HAT1 expression in LCCs can induce LCCs apoptosis, which may be a potential novel therapy for the treatment of LC.

Jolkinolide B induces apoptosis in MDA-MB-231 cells through inhibition of the PI3K/Akt signaling pathway.

PubMed

Lin, Yu; Cui, Hongxia; Xu, Huiyu; Yue, Liling; Xu, Hao; Jiang, Liyan; Liu, Jicheng

2012-06-01

The phosphoinositol-3-kinase (PI3K)/Akt signal transduction pathway is critically important for tumor cell growth, proliferation and apoptosis. Apoptosis activation has been reported to be a good target in cancer therapies. In this study, we have found that jolkinolide B (JB), a diterpenoid from the traditional Chinese medicinal herb Euphorbia fischeriana Steud, strongly inhibited the expression of the PI3K p85 subunit and the phosphorylation of Akt. Furthermore, we evaluated the effects of JB on the proliferation and apoptosis of MDA-MB-231 human breast cancer cells. Our results show significant induction of apoptosis in MDA-MB-231 cells incubated with JB. This effect was enhanced by combination with LY294002. In addition, treatment with JB could induce downregulation of the Bcl-2/Bax ratio, and subsequent promotion of mitochondrial release of cytochrome c and activation of caspase-3. Taken together, JB-induced apoptosis of MDA-MB-231 cells occurs through the mitochondrial pathway. Further, the PI3K/Akt signaling cascade plays a role in the induction of apoptosis in JB-treated cells. These observations suggest that JB may have therapeutic applications in the treatment of cancer.

5-Fluorouracil-induced apoptosis in cultured oral cancer cells.

PubMed

Tong, D; Poot, M; Hu, D; Oda, D

2000-03-01

Chemotherapy is commonly used to treat advanced oral squamous cell carcinoma (SCC) and is known to kill cancer cells through apoptosis. Our hypothesis states that 5-fluorouracil (5FU) also kills cultured oral epithelial cells through programmed cell death or apoptosis. Cultured oral cancer cells were exposed to an optimum dose of 20 mg/ml of 5FU. Cells were analyzed for changes in cell cycle distribution and induction of cell death including apoptosis. Normal control, human papilloma virus-immortalized (PP), ATCC SCC cell line (CA1) and two primary oral SCC cell lines (CA3 and -4) were studied. Inhibition of apoptosis by a pan-caspase inhibitor was used. SYTO 11 flow cytometry showed increased apoptosis in all 5FU-treated cell cultures compared to untreated controls. The results show biological variation in apoptotic response. CA1 had the lowest apoptotic rate of the cancer cell lines at 1.5%. Next lowest was CA3, followed by CA4 and PP. In addition, alteration in the G1 and S phase fractions were found. Untreated CA1 showed 28% G1, 53% S compared to 43% G1, and 40% S of treated. We investigated the pathway of apoptosis using the pan-caspase inhibitor IDN-1529 by methylthiazolyl diphenyl tetrazolium bromide (MTT) colorimetric analysis. Results showed mild inhibition of cell death when cells were incubated with 50 microM IDN-1529 for 24 h. This suggests a probable caspase-dependent apoptotic pathway. In conclusion, our data suggest that 5FU induces oral cancer cell death through apoptosis and that biological variation exists between normal and cancer cells and between different types of cancer cells themselves. Our data indicate that cultures of a useful in vitro model for chemosensitivity assays are possible. Our results also suggest a caspase-dependent pathway for chemocytotoxicity in oral SCC.

Lysophosphatidic acid rescues bone mesenchymal stem cells from hydrogen peroxide-induced apoptosis.

PubMed

Wang, Xian-Yun; Fan, Xue-Song; Cai, Lin; Liu, Si; Cong, Xiang-Feng; Chen, Xi

2015-03-01

The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.

Ligation of CD8α on human natural killer cells prevents activation-induced apoptosis and enhances cytolytic activity

PubMed Central

Addison, Elena G; North, Janet; Bakhsh, Ismail; Marden, Chloe; Haq, Sumaira; Al-Sarraj, Samia; Malayeri, Reza; Wickremasinghe, R Gitendra; Davies, Jeffrey K; Lowdell, Mark W

2005-01-01

It has been previously shown that the subset of human natural killer (NK) cells which express CD8 in a homodimeric α/α form are more cytotoxic than their CD8– counterparts but the mechanisms behind this differential cytolytic activity remained unknown. Target cell lysis by CD8– NK cells is associated with high levels of effector cell apoptosis, which is in contrast to the significantly lower levels found in the CD8α+ cells after lysis of the same targets. We report that cross-linking of the CD8α chains on NK cells induces rapid rises in intracellular Ca2+ and increased expression of CD69 at the cell surface by initiating the influx of extracellular Ca2+ ions. We demonstrate that secretion of cytolytic enzymes initiates NK-cell apoptosis from which CD8α+ NK cells are protected by an influx of exogenous calcium following ligation of CD8 on the NK-cell surface. This ligation is through interaction with fellow NK cells in the cell conjugate and can occur when the target cells lack major histocompatibility complex (MHC) Class I expression. Protection from apoptosis is blocked by preincubation of the NK cells with anti-MHC Class I antibody. Thus, in contrast to the CD8– subset, CD8α+ NK cells are capable of sequential lysis of multiple target cells. PMID:16236125

Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport

PubMed Central

Velez, Juliana; Pan, Rongqing; Lee, Jason T.C.; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

2016-01-01

Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax. PMID:27283492

Biguanides sensitize leukemia cells to ABT-737-induced apoptosis by inhibiting mitochondrial electron transport.

PubMed

Velez, Juliana; Pan, Rongqing; Lee, Jason T C; Enciso, Leonardo; Suarez, Marta; Duque, Jorge Eduardo; Jaramillo, Daniel; Lopez, Catalina; Morales, Ludis; Bornmann, William; Konopleva, Marina; Krystal, Gerald; Andreeff, Michael; Samudio, Ismael

2016-08-09

Metformin displays antileukemic effects partly due to activation of AMPK and subsequent inhibition of mTOR signaling. Nevertheless, Metformin also inhibits mitochondrial electron transport at complex I in an AMPK-independent manner, Here we report that Metformin and rotenone inhibit mitochondrial electron transport and increase triglyceride levels in leukemia cell lines, suggesting impairment of fatty acid oxidation (FAO). We also report that, like other FAO inhibitors, both agents and the related biguanide, Phenformin, increase sensitivity to apoptosis induction by the bcl-2 inhibitor ABT-737 supporting the notion that electron transport antagonizes activation of the intrinsic apoptosis pathway in leukemia cells. Both biguanides and rotenone induce superoxide generation in leukemia cells, indicating that oxidative damage may sensitize toABT-737 induced apoptosis. In addition, we demonstrate that Metformin sensitizes leukemia cells to the oligomerization of Bak, suggesting that the observed synergy with ABT-737 is mediated, at least in part, by enhanced outer mitochondrial membrane permeabilization. Notably, Phenformin was at least 10-fold more potent than Metformin in abrogating electron transport and increasing sensitivity to ABT-737, suggesting that this agent may be better suited for targeting hematological malignancies. Taken together, our results suggest that inhibition of mitochondrial metabolism by Metformin or Phenformin is associated with increased leukemia cell susceptibility to induction of intrinsic apoptosis, and provide a rationale for clinical studies exploring the efficacy of combining biguanides with the orally bioavailable derivative of ABT-737, Venetoclax.

Mitomycin C induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b and its targeting of RhoE.

PubMed

Sun, Yu; Ge, Yingbin; Fu, Yuxuan; Yan, Lianqi; Cai, Jun; Shi, Kun; Cao, Xiaojian; Lu, Chun

2015-10-15

Mitomycin C (MMC) is known to reduce epidural fibrosis, but the underlying mechanisms have not yet been elucidated. Aberrant miR-200b expressions have been reported in multiple types of fibrotic tissues from many diseases. The aim of this study was to clarify the mechanism by which MMC induces fibroblasts apoptosis and reduces epidural fibrosis. The expression of miR-200b in human fibroblasts was determined after MMC treatment, and the targeted association between miR-200b and RhoE was determined using the luciferase activity assay. The effects of MMC and miR-200b on human fibroblasts apoptosis were evaluated using flow cytometry and western blot analysis. The effects of MMC and miR-200b on epidural fibrosis were evaluated using the Rydell classification, hydroxyproline content, apoptotic cell count and histological analysis. The study revealed that MMC could significantly downregulate miR-200b expression and induce human fibroblasts apoptosis. The direct downregulation of miR-200b could induce human fibroblasts apoptosis. Furthermore, we identified the binding sequence for miR-200b within the 3' untranslated region of RhoE. RhoE was confirmed to be a direct target of miR-200b, and RhoE itself acted as a promoter of fibroblasts apoptosis. The inhibition of miR-200b increased fibroblasts apoptosis and reduced epidural fibrosis in rats, which was in accordance with the effect of MMC. This study suggests that MMC induces fibroblasts apoptosis and reduces epidural fibrosis by regulating miR-200b expression and its targeting of RhoE. Copyright © 2015 Elsevier B.V. All rights reserved.

PTK6 inhibition promotes apoptosis of Lapatinib-resistant Her2(+) breast cancer cells by inducing Bim.

PubMed

Park, Sun Hee; Ito, Koichi; Olcott, William; Katsyv, Igor; Halstead-Nussloch, Gwyneth; Irie, Hanna Y

2015-06-19

Protein tyrosine kinase 6 (PTK6) is a non-receptor tyrosine kinase that is highly expressed in Human Epidermal Growth Factor 2(+) (Her2(+)) breast cancers. Overexpression of PTK6 enhances anchorage-independent survival, proliferation, and migration of breast cancer cells. We hypothesized that PTK6 inhibition is an effective strategy to inhibit growth and survival of Her2(+) breast cancer cells, including those that are relatively resistant to Lapatinib, a targeted therapy for Her2(+) breast cancer, either intrinsically or acquired after continuous drug exposure. To determine the effects of PTK6 inhibition on Lapatinib-resistant Her2(+) breast cancer cell lines (UACC893R1 and MDA-MB-453), we used short hairpin ribonucleic acid (shRNA) vectors to downregulate PTK6 expression. We determined the effects of PTK6 downregulation on growth and survival in vitro and in vivo, as well as the mechanisms responsible for these effects. Lapatinib treatment of "sensitive" Her2(+) cells induces apoptotic cell death and enhances transcript and protein levels of Bim, a pro-apoptotic Bcl2 family member. In contrast, treatment of relatively "resistant" Her2(+) cells fails to induce Bim or enhance levels of cleaved, poly-ADP ribose polymerase (PARP). Downregulation of PTK6 expression in these "resistant" cells enhances Bim expression, resulting in apoptotic cell death. PTK6 downregulation impairs growth of these cells in in vitro 3-D Matrigel(TM) cultures, and also inhibits growth of Her2(+) primary tumor xenografts. Bim expression is critical for apoptosis induced by PTK6 downregulation, as co-expression of Bim shRNA rescued these cells from PTK6 shRNA-induced death. The regulation of Bim by PTK6 is not via changes in Erk/MAPK or Akt signaling, two pathways known to regulate Bim expression. Rather, PTK6 downregulation activates p38, and pharmacological inhibition of p38 activity prevents PTK6 shRNA-induced Bim expression and partially rescues cells from apoptosis. PTK6 downregulation

BAD overexpression inhibits cell growth and induces apoptosis via mitochondrial-dependent pathway in non-small cell lung cancer.

PubMed

Jiang, Li; Luo, Man; Liu, Dan; Chen, Bojiang; Zhang, Wen; Mai, Lin; Zeng, Jing; Huang, Na; Huang, Yi; Mo, Xianming; Li, Weimin

2013-06-01

The pro-apoptotic Bcl-2 protein BAD initiated apoptosis in human cells and has been identified as a prognostic marker in non-small cell lung cancer (NSCLC). In this study, we aimed to explore the functions of BAD in NSCLC. Overexpression of BAD was performed by transfecting different NSCLC cell lines with wild-type BAD. Cell proliferation, cell cycle, apoptosis, and invasion were characterized in vitro. Tumorigenicity was analyzed in vivo. Western blot was performed to determine the effects of BAD overexpression on the Bcl-2 family proteins and apoptosis-related proteins. Overexpression of BAD significantly inhibited cell proliferation in H1299, H292, and SPC-A1 but not in SK-MES-1 and H460 cell lines in vitro. BAD overexpression also reduced the tumorigenicity of H1299/SPC-A1 cell in vivo. However, no appreciable effects on cell cycle distribution and invasion were observed in all these cell lines. BAD overexpression also induced apoptosis in all cell types, in which process expression of mitochondrial cytochrom c (cyto-c) and caspase 3 were increased, whereas Bcl-xl, Bcl-2, Bax and caspase 8 expressions did not changed. These findings indicated that a mitochondrial pathway, in which process cyto-c was released from mitochondrial to activate caspase 3, was involved in BAD overexpression-mediated apoptosis. Our data suggested that increased expression of BAD enhance apoptosis and has negative influence on cell proliferation and tumor growth in NSCLC. Bad is a new potential target for tumor interventions.

Ku70 inhibits gemcitabine-induced DNA damage and pancreatic cancer cell apoptosis

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

Ma, Jiali; Hui, Pingping; Meng, Wenying

The current study focused on the role of Ku70, a DNA-dependent protein kinase (DNA-PK) complex protein, in pancreatic cancer cell resistance to gemcitabine. In both established cell lines (Mia-PaCa-2 and PANC-1) and primary human pancreatic cancer cells, shRNA/siRNA-mediated knockdown of Ku70 significantly sensitized gemcitabine-induced cell death and proliferation inhibition. Meanwhile, gemcitabine-induced DNA damage and subsequent pancreatic cancer cell apoptosis were also potentiated with Ku70 knockdown. On the other hand, exogenous overexpression of Ku70 in Mia-PaCa-2 cells suppressed gemcitabine-induced DNA damage and subsequent cell apoptosis. In a severe combined immune deficient (SCID) mice Mia-PaCa-2 xenograft model, gemcitabine-induced anti-tumor activity was remarkably pontificatedmore » when combined with Ku70 shRNA knockdown in the xenografts. The results of this preclinical study imply that Ku70 might be a primary resistance factor of gemcitabine, and Ku70 silence could significantly chemo-sensitize gemcitabine in pancreatic cancer cells. - Highlights: • Ku70 knockdown sensitizes gemcitabine-induced killing of pancreatic cancer cells. • Ku70 knockdown facilitates gemcitabine-induced DNA damage and cell apoptosis. • Ku70 overexpression deceases gemcitabine's sensitivity in pancreatic cancer cells. • Ku70 knockdown sensitizes gemcitabine-induced anti-tumor activity in vivo.« less

Scorpion (Androctonus bicolor) venom exhibits cytotoxicity and induces cell cycle arrest and apoptosis in breast and colorectal cancer cell lines.

PubMed

Al-Asmari, Abdulrahman K; Riyasdeen, Anvarbatcha; Abbasmanthiri, Rajamohamed; Arshaduddin, Mohammed; Al-Harthi, Fahad Ali

2016-01-01

The defective apoptosis is believed to play a major role in the survival and proliferation of neoplastic cells. Hence, the induction of apoptosis in cancer cells is one of the targets for cancer treatment. Researchers are considering scorpion venom as a potent natural source for cancer treatment because it contains many bioactive compounds. The main objective of the current study is to evaluate the anticancer property of Androctonus bicolor scorpion venom on cancer cells. Scorpions were milked by electrical stimulation of telsons and lyophilized. The breast (MDA-MB-231) and colorectal (HCT-8) cancer cells were maintained in appropriate condition. The venom cytotoxicity was assessed by 3-(4,5-di-methylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay, and the cellular and nuclear changes were studied with propidium iodide and 4',6-diamidino-2-phenylindole stain, respectively. The cell cycle arrest was examined using muse cell analyzer. The A. bicolor venom exerted cytotoxic effects on MDA-MB-231 and HCT-8 cells in a dose- and duration-dependent manner and induced apoptotic cell death. The treatment with this venom arrests the cancer cells in G0/G1 phase of cell cycle. The venom selectively induces the rate of apoptosis in MDA-MB-231 and HCT-8 cells as reflected by morphological and cell cycle studies. To the best of our knowledge, this is the first scientific evidence demonstrating the induction of apoptosis and cell cycle arrest by A. bicolor scorpion venom.

Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging.

PubMed

Baar, Marjolein P; Brandt, Renata M C; Putavet, Diana A; Klein, Julian D D; Derks, Kasper W J; Bourgeois, Benjamin R M; Stryeck, Sarah; Rijksen, Yvonne; van Willigenburg, Hester; Feijtel, Danny A; van der Pluijm, Ingrid; Essers, Jeroen; van Cappellen, Wiggert A; van IJcken, Wilfred F; Houtsmuller, Adriaan B; Pothof, Joris; de Bruin, Ron W F; Madl, Tobias; Hoeijmakers, Jan H J; Campisi, Judith; de Keizer, Peter L J

2017-03-23

The accumulation of irreparable cellular damage restricts healthspan after acute stress or natural aging. Senescent cells are thought to impair tissue function, and their genetic clearance can delay features of aging. Identifying how senescent cells avoid apoptosis allows for the prospective design of anti-senescence compounds to address whether homeostasis can also be restored. Here, we identify FOXO4 as a pivot in senescent cell viability. We designed a FOXO4 peptide that perturbs the FOXO4 interaction with p53. In senescent cells, this selectively causes p53 nuclear exclusion and cell-intrinsic apoptosis. Under conditions where it was well tolerated in vivo, this FOXO4 peptide neutralized doxorubicin-induced chemotoxicity. Moreover, it restored fitness, fur density, and renal function in both fast aging Xpd TTD/TTD and naturally aged mice. Thus, therapeutic targeting of senescent cells is feasible under conditions where loss of health has already occurred, and in doing so tissue homeostasis can effectively be restored. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucocorticoid receptor activation inhibits p53-induced apoptosis of MCF10Amyc cells via induction of protein kinase Cε.

PubMed

Aziz, Moammir H; Shen, Hong; Maki, Carl G

2012-08-24

Glucocorticoid receptor (GR) is a ligand-dependent transcription factor that can promote apoptosis or survival in a cell-specific manner. Activated GR has been reported to inhibit apoptosis in mammary epithelial cells and breast cancer cells by increasing pro-survival gene expression. In this study, activated GR inhibited p53-dependent apoptosis in MCF10A cells and human mammary epithelial cells that overexpress the MYC oncogene. Specifically, GR agonists hydrocortisone or dexamethasone inhibited p53-dependent apoptosis induced by cisplatin, ionizing radiation, or the MDM2 antagonist Nutlin-3. In contrast, the GR antagonist RU486 sensitized the cells to apoptosis by these agents. Apoptosis inhibition was associated with maintenance of mitochondrial membrane potential, diminished caspase-3 and -7 activation, and increased expression at both the mRNA and protein level of the anti-apoptotic PKC family member PKCε. Knockdown of PKCε via siRNA targeting reversed the protective effect of dexamethasone and restored apoptosis sensitivity. These data provide evidence that activated GR can inhibit p53-dependent apoptosis through induction of the anti-apoptotic factor PKCε.

Glycogen synthase kinase-3 inhibition sensitizes human induced pluripotent stem cells to thiol-containing antioxidants induced apoptosis.

PubMed

Tu, Chengyi; Xu, Robert; Koleti, Meghana; Zoldan, Janet

2017-08-01

Inhibition of glycogen synthase kinase 3 (GSK3) is an extensively used strategy to activate Wnt pathway for pluripotent stem cell (PSC) differentiation. However, the effects of such inhibition on PSCs, besides upregulating the Wnt pathway, have rarely been investigated despite that GSK3 is broadly involved in other cellular activities such as insulin signaling and cell growth/survival regulation. Here we describe a previously unknown synergistic effect between GSK3 inhibition (e.g., Chir99021 and LY2090314) and various normally non-toxic thiol-containing antioxidants (e.g., N-acetylcysteine, NAC) on the induction of apoptosis in human induced pluripotent stem cells (iPSCs). Neither Chir99021 nor the antioxidants individually induced significant apoptosis, whereas their combined treatment resulted in rapid and extensive apoptosis, with substantial caspase 3 activity observed within 3h and over 90% decrease in cell viability after 24h. We confirmed the generality of this phenomenon with multiple independent iPSCs lines, various thiol-based antioxidants and distinct GSK3 inhibitors. Mechanistically, we demonstrated that rapamycin treatment could substantially reduce cell death, suggesting the critical role of mammalian target of rapamycin (mTOR). Akt dysregulation was also found to partially contribute to cell apoptosis but was not the primary cause. Further, this coordinated proapoptotic effect was not detected in mouse ESCs but was present in another human cells line: a breast cancer cell line (MDA-MB-231). Given the wide use of GSK3 inhibition in biomedical research: from iPSC differentiation to cancer intervention and the treatment of neuronal diseases, researchers can potentially take advantage of or avoid this synergistic effect for improved experimental or clinical outcome. Copyright © 2017. Published by Elsevier B.V.

Optical imaging of TNF-α induced apoptosis pathway in living PC12 cells