Heterozygous inactivation of tsc2 enhances tumorigenesis in p53 mutant zebrafish

PubMed Central

Kim, Seok-Hyung; Kowalski, Marie L.; Carson, Robert P.; Bridges, L. Richard; Ess, Kevin C.

2013-01-01

SUMMARY Tuberous sclerosis complex (TSC) is a multi-organ disorder caused by mutations of the TSC1 or TSC2 genes. A key function of these genes is to inhibit mTORC1 (mechanistic target of rapamycin complex 1) kinase signaling. Cells deficient for TSC1 or TSC2 have increased mTORC1 signaling and give rise to benign tumors, although, as a rule, true malignancies are rarely seen. In contrast, other disorders with increased mTOR signaling typically have overt malignancies. A better understanding of genetic mechanisms that govern the transformation of benign cells to malignant ones is crucial to understand cancer pathogenesis. We generated a zebrafish model of TSC and cancer progression by placing a heterozygous mutation of the tsc2 gene in a p53 mutant background. Unlike tsc2 heterozygous mutant zebrafish, which never exhibited cancers, compound tsc2;p53 mutants had malignant tumors in multiple organs. Tumorigenesis was enhanced compared with p53 mutant zebrafish. p53 mutants also had increased mTORC1 signaling that was further enhanced in tsc2;p53 compound mutants. We found increased expression of Hif1-α, Hif2-α and Vegf-c in tsc2;p53 compound mutant zebrafish compared with p53 mutant zebrafish. Expression of these proteins probably underlies the increased angiogenesis seen in compound mutant zebrafish compared with p53 mutants and might further drive cancer progression. Treatment of p53 and compound mutant zebrafish with the mTORC1 inhibitor rapamycin caused rapid shrinkage of tumor size and decreased caliber of tumor-associated blood vessels. This is the first report using an animal model to show interactions between tsc2, mTORC1 and p53 during tumorigenesis. These results might explain why individuals with TSC rarely have malignant tumors, but also suggest that cancer arising in individuals without TSC might be influenced by the status of TSC1 and/or TSC2 mutations and be potentially treatable with mTORC1 inhibitors. PMID:23580196

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

Wang, Yuli; Zhang, Pengju; Wang, Yunshan

The ErbB3 receptor–binding protein EBP1 encodes two alternatively spliced isoforms P48 and P42. While there is evidence of differential roles for these isoforms in tumorigenesis, little is known about their underlying mechanisms. In this paper, we demonstrate that EBP1 isoforms interact with the SCF-type ubiquitin ligase FBXW7 in distinct ways to exert opposing roles in tumorigenesis. EBP1 P48 bound to the WD domain of FBXW7 as an oncogenic substrate of FBXW7. EBP1 P48 binding sequestered FBXW7α to the cytosol, modulating its role in protein degradation and attenuating its tumor suppressor function. In contrast, EBP1 P42 bound to both the F-boxmore » domain of FBXW7 as well as FBXW7 substrates. This adapter function of EBP1 P42 stabilized the interaction of FBXW7 with its substrates and promoted FBXW7-mediated degradation of oncogenic targets, enhancing its overall tumor-suppressing function. Finally and overall, our results establish distinct physical and functional interactions between FBXW7 and EBP1 isoforms, which yield their mechanistically unique isoform-specific functions of EBP1 in cancer.« less

Deregulation of the endogenous C/EBPβ LIP isoform predisposes to tumorigenesis.

PubMed

Bégay, Valérie; Smink, Jeske J; Loddenkemper, Christoph; Zimmermann, Karin; Rudolph, Cornelia; Scheller, Marina; Steinemann, Doris; Leser, Ulf; Schlegelberger, Brigitte; Stein, Harald; Leutz, Achim

2015-01-01

Two long and one truncated isoforms (termed LAP*, LAP, and LIP, respectively) of the transcription factor CCAAT enhancer binding protein beta (C/EBPβ) are expressed from a single intronless Cebpb gene by alternative translation initiation. Isoform expression is sensitive to mammalian target of rapamycin (mTOR)-mediated activation of the translation initiation machinery and relayed through an upstream open reading frame (uORF) on the C/EBPβ mRNA. The truncated C/EBPβ LIP, initiated by high mTOR activity, has been implied in neoplasia, but it was never shown whether endogenous C/EBPβ LIP may function as an oncogene. In this study, we examined spontaneous tumor formation in C/EBPβ knockin mice that constitutively express only the C/EBPβ LIP isoform from its own locus. Our data show that deregulated C/EBPβ LIP predisposes to oncogenesis in many tissues. Gene expression profiling suggests that C/EBPβ LIP supports a pro-tumorigenic microenvironment, resistance to apoptosis, and alteration of cytokine/chemokine expression. The results imply that enhanced translation reinitiation of C/EBPβ LIP promotes tumorigenesis. Accordingly, pharmacological restriction of mTOR function might be a therapeutic option in tumorigenesis that involves enhanced expression of the truncated C/EBPβ LIP isoform. Elevated C/EBPβ LIP promotes cancer in mice. C/EBPβ LIP is upregulated in B-NHL. Deregulated C/EBPβ LIP alters apoptosis and cytokine/chemokine networks. Deregulated C/EBPβ LIP may support a pro-tumorigenic microenvironment.

Enhancement of DEN-induced liver tumorigenesis in heme oxygenase-1 G143H mutant transgenic mice

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

Jin, Jianfeng; Wang, Dayong; Xiao, Haifeng

Heme oxygenase (HO) is the rate-limiting enzyme in heme metabolism. HO-1 exhibits anti-oxidative and anti-inflammatory function via the actions of its metabolite, respectively. A growing body of evidence demonstrates that HO-1 is implicated in the pathogenesis and progression of several types of cancer. However, whether HO-1 takes part in healthy-premalignant-malignant transformation is still undefined. In this study, we took advantage of transgenic mice which over-expressed HO-1 dominant negative mutant (HO-1 G143H) and observed its susceptibility to DEN-induced hepatocarcinogenesis. Our results indicate that HO-1 G143H mutant accelerates the progression of tumorigenesis and tumor growth. The mechanism is closely related to enhancementmore » of ROS production which induce more hepatocytes death and secretion of inflammatory cytokines, proliferation of surviving hepatocytes. Our result provides the direct evidence that HO-1 plays an important protective role in liver carcinogenesis. Alternatively, we suggest the possible explanation on effect of HO-1 promoter polymorphism which involved in tumorigenesis. - Highlights: • Enhancement of DEN-induced hepatocarcinogenesis in HO-1 G143H Tg mice. • HO-1G143H mutant enhanced DEN-induced ROS production and liver injury. • HO-1G143H mutant aggravated DEN-induced changes of inflammatory factors and cell proliferation.« less

The Linear ubiquitin chain assembly complex acts as a liver tumor suppressor and inhibits hepatocyte apoptosis and hepatitis.

PubMed

Shimizu, Yutaka; Peltzer, Nieves; Sevko, Alexandra; Lafont, Elodie; Sarr, Aida; Draberova, Helena; Walczak, Henning

2017-06-01

Linear ubiquitination is a key posttranslational modification that regulates immune signaling and cell death pathways, notably tumor necrosis factor receptor 1 (TNFR1) signaling. The only known enzyme complex capable of forming linear ubiquitin chains under native conditions to date is the linear ubiquitin chain assembly complex, of which the catalytic core component is heme-oxidized iron regulatory protein 2 ubiquitin ligase-1-interacting protein (HOIP). To understand the underlying mechanisms of maintenance of liver homeostasis and the role of linear ubiquitination specifically in liver parenchymal cells, we investigated the physiological role of HOIP in the liver parenchyma. To do so, we created mice harboring liver parenchymal cell-specific deletion of HOIP (Hoip Δhep mice) by crossing Hoip-floxed mice with albumin-Cre mice. HOIP deficiency in liver parenchymal cells triggered tumorigenesis at 18 months of age preceded by spontaneous hepatocyte apoptosis and liver inflammation within the first month of life. In line with the emergence of inflammation, Hoip Δhep mice displayed enhanced liver regeneration and DNA damage. In addition, consistent with increased apoptosis, HOIP-deficient hepatocytes showed enhanced caspase activation and endogenous formation of a death-inducing signaling complex which activated caspase-8. Unexpectedly, exacerbated caspase activation and apoptosis were not dependent on TNFR1, whereas ensuing liver inflammation and tumorigenesis were promoted by TNFR1 signaling. The linear ubiquitin chain assembly complex serves as a previously undescribed tumor suppressor in the liver, restraining TNFR1-independent apoptosis in hepatocytes which, in its absence, is causative of TNFR1-mediated inflammation, resulting in hepatocarcinogenesis. (Hepatology 2017;65:1963-1978). © 2017 The Authors. Hepatology published by Wiley Periodicals, Inc., on behalf of the American Association for the Study of Liver Diseases.

Smad4 suppresses the tumorigenesis and aggressiveness of neuroblastoma through repressing the expression of heparanase

PubMed Central

Qu, Hongxia; Zheng, Liduan; Jiao, Wanju; Mei, Hong; Li, Dan; Song, Huajie; Fang, Erhu; Wang, Xiaojing; Li, Shiwang; Huang, Kai; Tong, Qiangsong

2016-01-01

Heparanase (HPSE) is the only endo-β-D-glucuronidase that is correlated with the progression of neuroblastoma (NB), the most common extracranial malignancy in childhood. However, the mechanisms underlying HPSE expression in NB still remain largely unknown. Herein, through analyzing cis-regulatory elements and mining public microarray datasets, we identified SMAD family member 4 (Smad4) as a crucial transcription regulator of HPSE in NB. We demonstrated that Smad4 repressed the HPSE expression at the transcriptional levels in NB cells. Mechanistically, Smad4 suppressed the HPSE expression through directly binding to its promoter and repressing the lymphoid enhancer binding factor 1 (LEF1)-facilitated transcription of HPSE via physical interaction. Gain- and loss-of-function studies demonstrated that Smad4 inhibited the growth, invasion, metastasis, and angiogenesis of NB cells in vitro and in vivo. Restoration of HPSE expression prevented the NB cells from changes in these biological features induced by Smad4. In clinical NB specimens, Smad4 was under-expressed and inversely correlated with HPSE levels, while LEF1 was highly expressed and positively correlated with HPSE expression. Patients with high Smad4 expression, low LEF1 or HPSE levels had greater survival probability. These results demonstrate that Smad4 suppresses the tumorigenesis and aggressiveness of NB through repressing the HPSE expression. PMID:27595937

Autophagy in tumorigenesis and energy metabolism: friend by day, foe by night.

PubMed

Mathew, Robin; White, Eileen

2011-02-01

Autophagy is the mechanism by which cells consume parts of themselves to survive starvation and stress. This self-cannibalization limits cell death and tissue inflammation, recycles energy and biosynthetic substrates and removes damaged proteins and organelles, accumulation of which is toxic. In normal tissues, autophagy-mediated damage mitigation may suppress tumorigenesis, while in advanced tumors macromolecular recycling may support survival by buffering metabolic demand under stress. As a result, autophagy-activation in normal cells may suppress tumorigenesis, while autophagy inhibition may be beneficial for the therapy of established tumors. The mechanisms by which autophagy supports cancer cell metabolism are slowly emerging. As cancer is being increasingly recognized as a metabolic disease, how autophagy-mediated catabolism impacts cellular and mammalian metabolism and tumor growth is of great interest. Most cancer therapeutics induce autophagy, either directly by modulating signaling pathways that control autophagy in the case of many targeted therapies, or indirectly in the case of cytotoxic therapy. However, the functional consequence of autophagy induction in the context of cancer therapy is not yet clear. A better understanding of how autophagy modulates cell metabolism under various cellular stresses and the consequences of this on tumorigenesis will help develop better therapeutic strategies against cancer prevention and treatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

A novel type of cellular senescence that can be enhanced in mouse models and human tumor xenografts to suppress prostate tumorigenesis

PubMed Central

Alimonti, Andrea; Nardella, Caterina; Chen, Zhenbang; Clohessy, John G.; Carracedo, Arkaitz; Trotman, Lloyd C.; Cheng, Ke; Varmeh, Shohreh; Kozma, Sara C.; Thomas, George; Rosivatz, Erika; Woscholski, Rudiger; Cognetti, Francesco; Scher, Howard I.; Pandolfi, Pier Paolo

2010-01-01

Irreversible cell growth arrest, a process termed cellular senescence, is emerging as an intrinsic tumor suppressive mechanism. Oncogene-induced senescence is thought to be invariably preceded by hyperproliferation, aberrant replication, and activation of a DNA damage checkpoint response (DDR), rendering therapeutic enhancement of this process unsuitable for cancer treatment. We previously demonstrated in a mouse model of prostate cancer that inactivation of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (Pten) elicits a senescence response that opposes tumorigenesis. Here, we show that Pten-loss–induced cellular senescence (PICS) represents a senescence response that is distinct from oncogene-induced senescence and can be targeted for cancer therapy. Using mouse embryonic fibroblasts, we determined that PICS occurs rapidly after Pten inactivation, in the absence of cellular proliferation and DDR. Further, we found that PICS is associated with enhanced p53 translation. Consistent with these data, we showed that in mice p53-stabilizing drugs potentiated PICS and its tumor suppressive potential. Importantly, we demonstrated that pharmacological inhibition of PTEN drives senescence and inhibits tumorigenesis in vivo in a human xenograft model of prostate cancer. Taken together, our data identify a type of cellular senescence that can be triggered in nonproliferating cells in the absence of DNA damage, which we believe will be useful for developing a “pro-senescence” approach for cancer prevention and therapy. PMID:20197621

Tumor promoter-induced sulfiredoxin is required for mouse skin tumorigenesis.

PubMed

Wu, Lisha; Jiang, Hong; Chawsheen, Hedy A; Mishra, Murli; Young, Matthew R; Gerard, Matthieu; Toledano, Michel B; Colburn, Nancy H; Wei, Qiou

2014-05-01

Sulfiredoxin (Srx), the exclusive enzyme that reduces the hyperoxidized inactive form of peroxiredoxins (Prxs), has been found highly expressed in several types of human skin cancer. To determine whether Srx contributed to skin tumorigenesis in vivo, Srx null mice were generated on an FVB background. Mouse skin tumorigenesis was induced by a 7,12-dimethylbenz[α]anthracene/12-O-tetradecanoylphorbol-13-acetate (DMBA/TPA) protocol. We found that the number, volume and size of papillomas in Srx(-/-) mice were significantly fewer compared with either wild-type (Wt) or heterozygous (Het) siblings. Histopathological analysis revealed more apoptotic cells in tumors from Srx(-/-) mice. Mechanistic studies in cell culture revealed that Srx was stimulated by TPA in a redox-independent manner. This effect was mediated transcriptionally through the activation of mitogen-activated protein kinase and Jun-N-terminal kinase. We also demonstrated that Srx was capable of reducing hyperoxidized Prxs to facilitate cell survival under oxidative stress conditions. These findings suggested that loss of Srx protected mice, at least partially, from DMBA/TPA-induced skin tumorigenesis. Therefore, Srx has an oncogenic role in skin tumorigenesis and targeting Srx may provide novel strategies for skin cancer prevention or treatment.

Distinct Interactions of EBP1 Isoforms with FBXW7 Elicits Different Functions in Cancer

DOE PAGES

Wang, Yuli; Zhang, Pengju; Wang, Yunshan; ...

2017-02-16

The ErbB3 receptor–binding protein EBP1 encodes two alternatively spliced isoforms P48 and P42. While there is evidence of differential roles for these isoforms in tumorigenesis, little is known about their underlying mechanisms. In this paper, we demonstrate that EBP1 isoforms interact with the SCF-type ubiquitin ligase FBXW7 in distinct ways to exert opposing roles in tumorigenesis. EBP1 P48 bound to the WD domain of FBXW7 as an oncogenic substrate of FBXW7. EBP1 P48 binding sequestered FBXW7α to the cytosol, modulating its role in protein degradation and attenuating its tumor suppressor function. In contrast, EBP1 P42 bound to both the F-boxmore » domain of FBXW7 as well as FBXW7 substrates. This adapter function of EBP1 P42 stabilized the interaction of FBXW7 with its substrates and promoted FBXW7-mediated degradation of oncogenic targets, enhancing its overall tumor-suppressing function. Finally and overall, our results establish distinct physical and functional interactions between FBXW7 and EBP1 isoforms, which yield their mechanistically unique isoform-specific functions of EBP1 in cancer.« less

TCF7L1 promotes skin tumorigenesis independently of β-catenin through induction of LCN2

PubMed Central

Ku, Amy T; Shaver, Timothy M; Rao, Ajay S; Howard, Jeffrey M; Rodriguez, Christine N; Miao, Qi; Garcia, Gloria; Le, Diep; Yang, Diane; Borowiak, Malgorzata; Cohen, Daniel N; Chitsazzadeh, Vida; Diwan, Abdul H; Tsai, Kenneth Y; Nguyen, Hoang

2017-01-01

The transcription factor TCF7L1 is an embryonic stem cell signature gene that is upregulated in multiple aggressive cancer types, but its role in skin tumorigenesis has not yet been defined. Here we document TCF7L1 upregulation in skin squamous cell carcinoma (SCC) and demonstrate that TCF7L1 overexpression increases tumor incidence, tumor multiplicity, and malignant progression in the chemically induced mouse model of skin SCC. Additionally, we show that downregulation of TCF7L1 and its paralogue TCF7L2 reduces tumor growth in a xenograft model of human skin SCC. Using separation-of-function mutants, we show that TCF7L1 promotes tumor growth, enhances cell migration, and overrides oncogenic RAS-induced senescence independently of its interaction with β-catenin. Through transcriptome profiling and combined gain- and loss-of-function studies, we identified LCN2 as a major downstream effector of TCF7L1 that drives tumor growth. Our findings establish a tumor-promoting role for TCF7L1 in skin and elucidate the mechanisms underlying its tumorigenic capacity. DOI: http://dx.doi.org/10.7554/eLife.23242.001 PMID:28467300

PAF-Myc-Controlled Cell Stemness Is Required for Intestinal Regeneration and Tumorigenesis.

PubMed

Kim, Moon Jong; Xia, Bo; Suh, Han Na; Lee, Sung Ho; Jun, Sohee; Lien, Esther M; Zhang, Jie; Chen, Kaifu; Park, Jae-Il

2018-03-12

The underlying mechanisms of how self-renewing cells are controlled in regenerating tissues and cancer remain ambiguous. PCNA-associated factor (PAF) modulates DNA repair via PCNA. Also, PAF hyperactivates Wnt/β-catenin signaling independently of PCNA interaction. We found that PAF is expressed in intestinal stem and progenitor cells (ISCs and IPCs) and markedly upregulated during intestinal regeneration and tumorigenesis. Whereas PAF is dispensable for intestinal homeostasis, upon radiation injury, genetic ablation of PAF impairs intestinal regeneration along with the severe loss of ISCs and Myc expression. Mechanistically, PAF conditionally occupies and transactivates the c-Myc promoter, which induces the expansion of ISCs/IPCs during intestinal regeneration. In mouse models, PAF knockout inhibits Apc inactivation-driven intestinal tumorigenesis with reduced tumor cell stemness and suppressed Wnt/β-catenin signaling activity, supported by transcriptome profiling. Collectively, our results unveil that the PAF-Myc signaling axis is indispensable for intestinal regeneration and tumorigenesis by positively regulating self-renewing cells. Copyright © 2018 Elsevier Inc. All rights reserved.

Positive feedback loop and synergistic effects between hypoxia-inducible factor-2α and stearoyl-CoA desaturase-1 promote tumorigenesis in clear cell renal cell carcinoma.

PubMed

Zhang, Yujian; Wang, Hui; Zhang, Jin; Lv, Jianwei; Huang, Yiran

2013-04-01

Adapting to hypoxic stress is pivotal in tumor progression and determining tumor malignancy. The transcriptional factor hypoxia-inducible factor (HIF) is crucial in modulating tumorous hypoxic responses through altering cell energy metabolism, which includes the modification of glucose and lipid metabolism-associated gene expression. Stearoyl-CoA desaturase-1 (SCD1) is the main isoform of SCDs, the rate-limiting enzymes in the biosynthesis of monounsaturated fatty acids from saturated fatty acids, which is extensively activated in cancer progression. In this study, we found that SCD1 and HIF-2α were overexpressed in human clear cell renal cell carcinoma (ccRCC) tissues and ccRCC cell lines, and were upregulated in the 786-0 ccRCC cell line under hypoxia. Knockdown of SCD1 or HIF-2α impacted the other's expression. Enhancing SCD1 resulted in HIF-2α upregulation, which could be blocked by inhibiting the PI3K/Akt pathway. Deficiency of SCD1 or HIF-2α in 768-0 cells led to apoptosis, less colony formation ability, and decreased cell migration. More obvious effects were observed in 786-0 cells with double SCD1 and HIF-2α knockdown. These results indicate a PI3K/Akt-mediated loop between SCD1 and HIF-2α that mutually enhances their protein levels. Both SCD1 and HIF-2α are critical to promoting tumorigenesis by synergistically acting on maintaining cell survival, triggering cell migration, and enhancing the colony formation ability of cancer cells. © 2013 Japanese Cancer Association.

SOX4 is essential for prostate tumorigenesis initiated by PTEN ablation | Office of Cancer Genomics

Cancer.gov

Understanding remains incomplete of the mechanisms underlying initiation and progression of prostate cancer, the most commonly diagnosed cancer in American men. The transcription factor SOX4 is overexpressed in many human cancers, including prostate cancer, suggesting it may participate in prostate tumorigenesis. In this study, we investigated this possibility by genetically deleting Sox4 in a mouse model of prostate cancer initiated by loss of the tumor suppressor Pten.

A Critical Reassessment of the Role of Mitochondria in Tumorigenesis

PubMed Central

Salas, Antonio; Yao, Yong-Gang; Macaulay, Vincent; Vega, Ana; Carracedo, Ángel; Bandelt, Hans-Jürgen

2005-01-01

Background Mitochondrial DNA (mtDNA) is being analyzed by an increasing number of laboratories in order to investigate its potential role as an active marker of tumorigenesis in various types of cancer. Here we question the conclusions drawn in most of these investigations, especially those published in high-rank cancer research journals, under the evidence that a significant number of these medical mtDNA studies are based on obviously flawed sequencing results. Methods and Findings In our analyses, we take a phylogenetic approach and employ thorough database searches, which together have proven successful for detecting erroneous sequences in the fields of human population genetics and forensics. Apart from conceptual problems concerning the interpretation of mtDNA variation in tumorigenesis, in most cases, blocks of seemingly somatic mutations clearly point to contamination or sample mix-up and, therefore, have nothing to do with tumorigenesis. Conclusion The role of mitochondria in tumorigenesis remains unclarified. Our findings of laboratory errors in many contributions would represent only the tip of the iceberg since most published studies do not provide the raw sequence data for inspection, thus hindering a posteriori evaluation of the results. There is no precedent for such a concatenation of errors and misconceptions affecting a whole subfield of medical research. PMID:16187796

Nardilysin controls intestinal tumorigenesis through HDAC1/p53-dependent transcriptional regulation.

PubMed

Kanda, Keitaro; Sakamoto, Jiro; Matsumoto, Yoshihide; Ikuta, Kozo; Goto, Norihiro; Morita, Yusuke; Ohno, Mikiko; Nishi, Kiyoto; Eto, Koji; Kimura, Yuto; Nakanishi, Yuki; Ikegami, Kanako; Yoshikawa, Takaaki; Fukuda, Akihisa; Kawada, Kenji; Sakai, Yoshiharu; Ito, Akihiro; Yoshida, Minoru; Kimura, Takeshi; Chiba, Tsutomu; Nishi, Eiichiro; Seno, Hiroshi

2018-04-19

Colon cancer is a complex disease affected by a combination of genetic and epigenetic factors. Here we demonstrate that nardilysin (N-arginine dibasic convertase; NRDC), a metalloendopeptidase of the M16 family, regulates intestinal tumorigenesis via its nuclear functions. NRDC is highly expressed in human colorectal cancers. Deletion of the Nrdc gene in ApcMin mice crucially suppressed intestinal tumor development. In ApcMin mice, epithelial cell-specific deletion of Nrdc recapitulated the tumor suppression observed in Nrdc-null mice. Moreover, epithelial cell-specific overexpression of Nrdc significantly enhanced tumor formation in ApcMin mice. Notably, epithelial NRDC controlled cell apoptosis in a gene dosage-dependent manner. In human colon cancer cells, nuclear NRDC directly associated with HDAC1, and controlled both acetylation and stabilization of p53, with alterations of p53 target apoptotic factors. These findings demonstrate that NRDC is critically involved in intestinal tumorigenesis through its epigenetic regulatory function, and targeting NRDC may lead to a novel prevention or therapeutic strategy against colon cancer.

Resveratrol inhibits age-dependent spontaneous tumorigenesis by SIRT1-mediated post-translational modulations in the annual fish Nothobranchius guentheri

PubMed Central

Liu, Tingting; Ma, Long; Zheng, Zhaodi; Li, Fenglin; Liu, Shan; Xie, Yingbo; Li, Guorong

2017-01-01

Resveratrol, SIRT1 activator, inhibits carcinogenesis predominantly performed in transgenic animal models, orthotopic cancers of nude mice or different cancer cell lines, but its effects during process of spontaneous tumors using vertebrate models remain untested. Spontaneous liver neoplasm is an age-related disease and is inhibited by resveratrol in the annual fish Nothobranchius guentheri, which indicates that the fish can act as an excellent model to study spontaneous tumorigenesis. Totally, 175 fish were fed with resveratrol and another 175 fish for controls. Treated fish were fed with resveratrol (25 μg/fish/day) from sexual maturity (4-month-old) until they were sacrificed at 6-, 9- and 12-month-old. Immunoblot, immunohistochemistry and co-immunoprecipitation were employed to investigate the underlying mechanisms that resveratrol inhibited age-dependent spontaneous tumorigenesis in the fish. Results showed that resveratrol increased protein level of SIRT1 and alleviated age-associated tumorigenesis in liver. With SIRT1 up-regulation, resveratrol reduced proliferation by deacetylating K-Ras and inactivating K-Ras/PI3K/AKT pathway; and promoted apoptosis through deacetylation and dephosphorylation of FoxOs, up-regulation of DLC1 and interaction between SIRT1 and DLC1, and dephosphorylation of DLC1 in spontaneous neoplasms. We established a novel short-lived fish model for understanding the molecular mechanisms of drugs on age-dependent spontaneous tumorigenesis. PMID:28903430

Bromelain nanoparticles protect against 7,12-dimethylbenz[a]anthracene induced skin carcinogenesis in mouse model.

PubMed

Bhatnagar, Priyanka; Pant, Aditya B; Shukla, Yogeshwer; Chaudhari, Bhushan; Kumar, Pradeep; Gupta, Kailash C

2015-04-01

Conventional cancer chemotherapy leads to severe side effects, which limits its use. Nanoparticles (NPs) based delivery systems offer an effective alternative. Several evidences highlight the importance of Bromelain (BL), a proteolytic enzyme, as an anti-tumor agent which however has been limited due to the requirement of high doses at the tumor site. Therefore, we illustrate the development of BL loaded poly (lactic-co-glycolic acid) NPs that show enhanced anti-tumor effects compared to free BL. The formulated NPs with a mean particle size of 130.4 ± 8.81 nm exhibited sustained release of BL. Subsequent investigation revealed enhanced anti-tumor ability of NPs in 2-stage skin tumorigenesis mice model. Reduction in average number of tumors (∼ 2.3 folds), delay in tumorigenesis (∼ 2 weeks), percent tumorigenesis (∼ 4 folds), and percent mortality rate as well as a reduction in the average tumor volume (∼ 2.5 folds) in mice as compared to free BL were observed. The NPs were found to be superior in exerting chemopreventive effects over chemotherapeutic effects at 10 fold reduced dose than free BL, validated by the enhanced ability of NPs (∼ 1.8 folds) to protect the DNA from induced damage. The effects were also supported by histopathological evaluations. NPs were also capable of modulating the expression of pro-apoptotic (P53, Bax) and anti-apoptotic (Bcl2) proteins. Therefore, our findings demonstrate that developed NPs formulation could be used to improve the efficacy of chemotherapy by exerting chemo-preventive effects against induced carcinogenesis at lower dosages. Copyright © 2015 Elsevier B.V. All rights reserved.

Yap reprograms glutamine metabolism to increase nucleotide biosynthesis and enable liver growth.

PubMed

Cox, Andrew G; Hwang, Katie L; Brown, Kristin K; Evason, Kimberley; Beltz, Sebastian; Tsomides, Allison; O'Connor, Keelin; Galli, Giorgio G; Yimlamai, Dean; Chhangawala, Sagar; Yuan, Min; Lien, Evan C; Wucherpfennig, Julia; Nissim, Sahar; Minami, Akihiro; Cohen, David E; Camargo, Fernando D; Asara, John M; Houvras, Yariv; Stainier, Didier Y R; Goessling, Wolfram

2016-08-01

The Hippo pathway is an important regulator of organ size and tumorigenesis. It is unclear, however, how Hippo signalling provides the cellular building blocks required for rapid growth. Here, we demonstrate that transgenic zebrafish expressing an activated form of the Hippo pathway effector Yap1 (also known as YAP) develop enlarged livers and are prone to liver tumour formation. Transcriptomic and metabolomic profiling identify that Yap1 reprograms glutamine metabolism. Yap1 directly enhances glutamine synthetase (glul) expression and activity, elevating steady-state levels of glutamine and enhancing the relative isotopic enrichment of nitrogen during de novo purine and pyrimidine biosynthesis. Genetic or pharmacological inhibition of GLUL diminishes the isotopic enrichment of nitrogen into nucleotides, suppressing hepatomegaly and the growth of liver cancer cells. Consequently, Yap-driven liver growth is susceptible to nucleotide inhibition. Together, our findings demonstrate that Yap1 integrates the anabolic demands of tissue growth during development and tumorigenesis by reprogramming nitrogen metabolism to stimulate nucleotide biosynthesis.

JAK signaling globally counteracts heterochromatic gene silencing.

PubMed

Shi, Song; Calhoun, Healani C; Xia, Fan; Li, Jinghong; Le, Long; Li, Willis X

2006-09-01

The JAK/STAT pathway has pleiotropic roles in animal development, and its aberrant activation is implicated in multiple human cancers. JAK/STAT signaling effects have been attributed largely to direct transcriptional regulation by STAT of specific target genes that promote tumor cell proliferation or survival. We show here in a Drosophila melanogaster hematopoietic tumor model, however, that JAK overactivation globally disrupts heterochromatic gene silencing, an epigenetic tumor suppressive mechanism. This disruption allows derepression of genes that are not direct targets of STAT, as evidenced by suppression of heterochromatin-mediated position effect variegation. Moreover, mutations in the genes encoding heterochromatin components heterochromatin protein 1 (HP1) and Su(var)3-9 enhance tumorigenesis induced by an oncogenic JAK kinase without affecting JAK/STAT signaling. Consistently, JAK loss of function enhances heterochromatic gene silencing, whereas overexpressing HP1 suppresses oncogenic JAK-induced tumors. These results demonstrate that the JAK/STAT pathway regulates cellular epigenetic status and that globally disrupting heterochromatin-mediated tumor suppression is essential for tumorigenesis induced by JAK overactivation.

JAK signaling globally counteracts heterochromatic gene silencing

PubMed Central

Shi, Song; Calhoun, Healani C; Xia, Fan; Li, Jinghong; Le, Long; Li, Willis X

2011-01-01

The JAK/STAT pathway has pleiotropic roles in animal development, and its aberrant activation is implicated in multiple human cancers1–3. JAK/STAT signaling effects have been attributed largely to direct transcriptional regulation by STAT of specific target genes that promote tumor cell proliferation or survival. We show here in a Drosophila melanogaster hematopoietic tumor model, however, that JAK overactivation globally disrupts heterochromatic gene silencing, an epigenetic tumor suppressive mechanism4. This disruption allows derepression of genes that are not direct targets of STAT, as evidenced by suppression of heterochromatin-mediated position effect variegation. Moreover, mutations in the genes encoding heterochromatin components heterochromatin protein 1 (HP1) and Su(var)3-9 enhance tumorigenesis induced by an oncogenic JAK kinase without affecting JAK/STAT signaling. Consistently, JAK loss of function enhances heterochromatic gene silencing, whereas overexpressing HP1 suppresses oncogenic JAK-induced tumors. These results demonstrate that the JAK/STAT pathway regulates cellular epigenetic status and that globally disrupting heterochromatin-mediated tumor suppression is essential for tumorigenesis induced by JAK overactivation. PMID:16892059

Yap reprograms glutamine metabolism to increase nucleotide biosynthesis and enable liver growth

PubMed Central

Brown, Kristin K.; Evason, Kimberley; Beltz, Sebastian; Tsomides, Allison; O'Connor, Keelin; Galli, Giorgio G.; Yimlamai, Dean; Chhangawala, Sagar; Yuan, Min; Lien, Evan C.; Wucherpfennig, Julia; Nissim, Sahar; Minami, Akihiro; Cohen, David E.; Camargo, Fernando D.; Asara, John M.; Houvras, Yariv; Stainier, Didier Y.R.; Goessling, Wolfram

2016-01-01

The Hippo pathway is an important regulator of organ size and tumorigenesis. It is unclear, however, how Hippo signaling provides the cellular building blocks required for rapid growth. Here, we demonstrate that transgenic zebrafish expressing an activated form of the Hippo pathway effector Yap1 (also known as YAP) develop enlarged livers and are prone to liver tumor formation. Transcriptomic and metabolomic profiling identify that Yap1 reprograms glutamine metabolism. Yap1 directly enhances glutamine synthetase (glul) expression and activity, elevating steady-state levels of glutamine and enhancing the relative isotopic enrichment of nitrogen during de novo purine and pyrimidine biosynthesis. Genetic or pharmacological inhibition of GLUL diminishes the isotopic enrichment of nitrogen into nucleotides, suppresses hepatomegaly and the growth of liver cancer cells. Consequently, Yap-driven liver growth is susceptible to nucleotide inhibition. Together, our findings demonstrate that Yap1 integrates the anabolic demands of tissue growth during development and tumorigenesis by reprogramming nitrogen metabolism to stimulate nucleotide biosynthesis. PMID:27428308

Mitochondria-Translocated PGK1 Functions as a Protein Kinase to Coordinate Glycolysis and the TCA Cycle in Tumorigenesis.

PubMed

Li, Xinjian; Jiang, Yuhui; Meisenhelder, Jill; Yang, Weiwei; Hawke, David H; Zheng, Yanhua; Xia, Yan; Aldape, Kenneth; He, Jie; Hunter, Tony; Wang, Liwei; Lu, Zhimin

2016-03-03

It is unclear how the Warburg effect that exemplifies enhanced glycolysis in the cytosol is coordinated with suppressed mitochondrial pyruvate metabolism. We demonstrate here that hypoxia, EGFR activation, and expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1); this is mediated by ERK-dependent PGK1 S203 phosphorylation and subsequent PIN1-mediated cis-trans isomerization. Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1) at T338, which activates PDHK1 to phosphorylate and inhibit the pyruvate dehydrogenase (PDH) complex. This reduces mitochondrial pyruvate utilization, suppresses reactive oxygen species production, increases lactate production, and promotes brain tumorigenesis. Furthermore, PGK1 S203 and PDHK1 T338 phosphorylation levels correlate with PDH S293 inactivating phosphorylation levels and poor prognosis in glioblastoma patients. This work highlights that PGK1 acts as a protein kinase in coordinating glycolysis and the tricarboxylic acid (TCA) cycle, which is instrumental in cancer metabolism and tumorigenesis. Copyright © 2016 Elsevier Inc. All rights reserved.

Polyamines and Nonmelanoma Skin Cancer

PubMed Central

Gilmour, Susan K.

2007-01-01

Elevated levels of polyamines have long been associated with skin tumorigenesis. Tightly regulated metabolism of polyamines is critical for cell survival and normal skin homeostasis, and these controls are dysregulated in skin tumorigenesis. A key enzyme in polyamine biosynthesis, ornithine decarboxylase (ODC) is upregulated in skin tumors compared to normal skin. Use of transgenic mouse models has demonstrated that polyamines play an essential role in the early promotional phase of skin tumorigenesis. The formation of skin tumors in these transgenic mice is dependent upon polyamine biosynthesis, especially putrescine, since treatment with inhibitors of ODC activity blocks the formation of skin tumors and causes the rapid regression of existing tumors. Although the mechanism by which polyamines promote skin tumorigenesis are not well understood, elevated levels of polyamines have been shown to stimulate epidermal proliferation, alter keratinocyte differentiation status, increase neovascularization, and increase synthesis of extracellular matrix proteins in a manner similar to that seen in wound healing. It is becoming increasingly apparent that elevated polyamine levels activate not only epidermal cells but also underlying stromal cells in the skin to promote the development and progression of skin tumors. The inhibition of polyamine biosynthesis has potential to be an effective chemoprevention strategy for nonmelanoma skin cancer. PMID:17234230

Hypothesis: neoplasms in myotonic dystrophy

PubMed Central

Hilbert, James E.; Martens, William; Thornton, Charles A.; Moxley, Richard T.; Greene, Mark H.

2011-01-01

Tumorigenesis is a multi-step process due to an accumulation of genetic mutations in multiple genes in diverse pathways which ultimately lead to loss of control over cell growth. It is well known that inheritance of rare germline mutations in genes involved in tumorigenesis pathways confer high lifetime risk of neoplasia in affected individuals. Furthermore, a substantial number of multiple malformation syndromes include cancer susceptibility in their phenotype. Studies of the mechanisms underlying these inherited syndromes have added to the understanding of both normal development and the pathophysiology of carcinogenesis. Myotonic dystrophy (DM) represents a group of autosomal dominant, multisystemic diseases that share the clinical features of myotonia, muscle weakness, and early-onset cataracts. Myotonic dystrophy type 1 (DM1) and myotonic dystrophy type 2 (DM2) result from unstable nucleotide repeat expansions in their respective genes. There have been multiple reports of tumors in individuals with DM, most commonly benign calcifying cutaneous tumors known as pilomatricomas. We provide a summary of the tumors reported in DM and a hypothesis for a possible mechanism of tumorigenesis. We hope to stimulate further study into the potential role of DM genes in tumorigenesis, and help define DM pathogenesis, and facilitate developing novel treatment modalities. PMID:19642006

Low doses of arsenic, via perturbing p53, promotes tumorigenesis

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

Ganapathy, Suthakar, E-mail: s.ganapathy@neu.edu

In drinking water and in workplace or living environments, low doses of arsenic can exist and operate as a potent carcinogen. Due to insufficient understanding and information on the pervasiveness of environmental exposures to arsenic, there is an urgent need to elucidate the underlying molecular mechanisms of arsenic regarding its carcinogenic effect on human health. In this study, we demonstrate that low doses of arsenic exposure mitigate or mask p53 function and further perturb intracellular redox state, which triggers persistent endoplasmic reticulum (ER) stress and activates UPR (unfolded protein response), leading to transformation or tumorigenesis. Thus, the results suggest thatmore » low doses of arsenic exposure, through attenuating p53-regulated tumor suppressive function, change the state of intracellular redox and create a microenvironment for tumorigenesis. Our study also provides the information for designing more effective strategies to prevent or treat human cancers initiated by arsenic exposure.« less

Lung tumorigenesis promoted by anti-apoptotic effects of cotinine, a nicotine metabolite through activation of PI3K/Akt pathway.

PubMed

Nakada, Tomohisa; Kiyotani, Kazuma; Iwano, Shunsuke; Uno, Takahiko; Yokohira, Masanao; Yamakawa, Keiko; Fujieda, Masaki; Saito, Tetsuya; Yamazaki, Hiroshi; Imaida, Katsumi; Kamataki, Tetsuya

2012-01-01

We previously found that genetic polymorphism in cytochrome P450 2A6 (CYP2A6) is one of the potential determinants of tobacco-related lung cancer risk. It has been reported that the plasma concentration of cotinine, a major metabolite of nicotine, in carriers of wild-type alleles of CYP2A6 is considerably higher than that in carriers of null or reduced-function alleles of CYP2A6, raising the possibility that cotinine plays an important role in the development of lung cancer. As a novel mechanism of lung tumorigenesis mediated by CYP2A6, we investigated the effects of cotinine on the suppression of apoptosis and promotion of lung tumor growth. In human lung adenocarcinoma A549 cells, cotinine inhibited doxorubicin-induced cell death by suppressing caspase-mediated apoptosis. Enhanced phosphorylation of Akt, a key factor responsible for cell survival and inhibition of apoptosis, was detected after cotinine treatment. These data suggest that cotinine suppresses caspase-mediated apoptosis induced by doxorubicin through activation of the PI3K/Akt pathway. Furthermore, we clarified that cotinine significantly facilitated tumor growth in the Lewis lung cancer model and accelerated development of lung adenomas induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in A/J mice. We herein propose that cotinine induces tumor promotion by inhibiting apoptosis and enhancing cellular proliferation, thus underlining the importance of CYP2A6 in tobacco-related lung tumorigenesis.

Gpr110 deficiency decelerates carcinogen-induced hepatocarcinogenesis via activation of the IL-6/STAT3 pathway

PubMed Central

Ma, Benting; Zhu, Junjie; Tan, Juan; Mao, Yulei; Tang, Lingyun; Shen, Chunling; Zhang, Hongxing; Kuang, Ying; Fei, Jian; Yang, Xiao; Wang, Zhugang

2017-01-01

Hepatocarcinogenesis is a complex process that includes pronounced necroinflammation, unregulated hepatocyte damage, subsequent extensive fibrosis, and carcinogenesis. GPR110 was an adhesion G protein-coupled receptor. Analysis of the expression pattern of Gpr110 in mice displayed that Gpr110 was expressed highly in liver, implicating the tissue compartments where Gpr110 could execute its functions, the role of Gpr110 in the physiological and pathological state of liver remains unclear. Based on a Gpr110 knockout mouse model, we evaluated the role of Gpr110 in hepatocarcinogenesis by using a carbon tetrachloride (CCl4)-induced liver injury and fibrosis model, as well as diethylnitrosamine (DEN) plus CCl4-induced liver cancer model. In this study, we found subdued chronic liver injury, reduced compensatory proliferation, lower liver fibrosis, but enhanced inflammation occurred in Gpr110-/- mice during CCl4 challenge. In addition, Gpr110-/- mice were resistant to liver tumorigenesis induced by DEN plus CCl4 injection. Molecular mechanisms underlying these differences correlated with augmented activation of the IL-6/STAT3 pathway, which exerted hepatoprotective effects during liver damage, fibrosis, and oncogenesis in Gpr110-/- mice. Furthermore, pharmacological inhibition of the activation of the IL-6/STAT3 pathway enhanced hepatic fibrosis and promoted DEN plus CCl4-induced carcinogenesis in Gpr110-/- mice. In summary, absence of Gpr110 decelerates liver fibrosis/cirrhosis progressing into tumorigenesis, due to strengthening activation of the IL-6/STAT3 pathway, leading to a weaker liver injury and fibrosis microenvironment. It is indicated that targeting Gpr110 and activating the IL-6/STAT3 pathway may be considered to be preventive methods for some cirrhosis transition. PMID:28401002

Obesity does not promote tumorigenesis of localized patient-derived prostate cancer xenografts

PubMed Central

Ascui, Natasha; Frydenberg, Mark; Risbridger, Gail P.; Taylor, Renea A.; Watt, Matthew J.

2016-01-01

There are established epidemiological links between obesity and the severity of prostate cancer. We directly tested this relationship by assessing tumorigenicity of patient-derived xenografts (PDXs) of moderate-grade localized prostate cancer in lean and obese severe combined immunodeficiency (SCID) mice. Mice were rendered obese and insulin resistant by high-fat feeding for 6 weeks prior to transplantation, and PDXs were assessed 10 weeks thereafter. Histological analysis of PDX grafts showed no differences in tumor pathology, prostate-specific antigen, androgen receptor and homeobox protein Nkx-3.1 expression, or proliferation index in lean versus obese mice. Whilst systemic obesity per se did not promote prostate tumorigenicity, we next asked whether the peri-prostatic adipose tissue (PPAT), which covers the prostate anteriorly, plays a role in prostate tumorigenesis. In vitro studies in a cellularized co-culture model of stromal and epithelial cells demonstrated that factors secreted from human PPAT are pro-tumorigenic. Accordingly, we recapitulated the prostate-PPAT spatial relationship by co-grafting human PPAT with prostate cancer in PDX grafts. PDX tissues were harvested 10 weeks after grafting, and histological analysis revealed no evidence of enhanced tumorigenesis with PPAT compared to prostate cancer grafts alone. Altogether, these data demonstrate that prostate cancer tumorigenicity is not accelerated in the setting of diet-induced obesity or in the presence of human PPAT, prompting the need for further work to define the at-risk populations of obesity-driven tumorigenesis and the biological factors linking obesity, adipose tissue and prostate cancer pathogenesis. PMID:27351281

Isocitrate dehydrogenase 1 is downregulated during early skin tumorigenesis which can be inhibited by overexpression of manganese superoxide dismutase.

PubMed

Robbins, Delira; Wittwer, Jennifer A; Codarin, Sarah; Circu, Magdalena L; Aw, Tak Yee; Huang, Ting-Ting; Van Remmen, Holly; Richardson, Arlan; Wang, David B; Witt, Stephan N; Klein, Ronald L; Zhao, Yunfeng

2012-08-01

Isocitrate dehydrogenase 1 (IDH1), a cytosolic enzyme that converts isocitrate to alpha-ketoglutarate, has been shown to be dysregulated during tumorigenesis. However, at what stage of cancer development IDH1 is dysregulated and how IDH1 may affect cell transformation and tumor promotion during early stages of cancer development are unclear. We used a skin cell transformation model and mouse skin epidermal tissues to study the role of IDH1 in early skin tumorigenesis. Our studies demonstrate that both the tumor promoter TPA and UVC irradiation decreased expression and activity levels of IDH1, not IDH2, in the tumor promotable JB6 P+ cell model. Skin epidermal tissues treated with dimethylbenz[α]anthracene/TPA also showed decreases in IDH1 expression and activity. In non-promotable JB6 P-cells, IDH1 was upregulated upon TPA treatment, whereas IDH2 was maintained at similar levels with TPA treatment. Interestingly, IDH1 knockdown enhanced, whereas IDH1 overexpression suppressed, TPA-induced cell transformation. Finally, manganese superoxide dismutase overexpression suppressed tumor promoter induced decreases in IDH1 expression and mitochondrial respiration, while intracellular alpha-ketoglutarate levels were unchanged. These results suggest that decreased IDH1 expression in early stage skin tumorigenesis is highly correlated with tumor promotion. In addition, oxidative stress might contribute to IDH1 inactivation, because manganese superoxide dismutase, a mitochondrial antioxidant enzyme, blocked decreases in IDH1 expression and activity. © 2012 Japanese Cancer Association.

Hormonally up-regulated neu-associated kinase: A novel target for breast cancer progression.

PubMed

Zambrano, Joelle N; Neely, Benjamin A; Yeh, Elizabeth S

2017-05-01

Hormonally up-regulated neu-associated Kinase (Hunk) is a protein kinase that was originally identified in the murine mammary gland and has been shown to be highly expressed in Human Epidermal Growth Factor Receptor 2 positive (HER2 + /ErbB2 + ) breast cancer cell lines as well as MMTV-neu derived mammary tumor cell lines. However, the physiological role of Hunk has been largely elusive since its identification. Though Hunk is predicted to be a Serine/Threonine (Ser/Thr) protein kinase with homology to the SNF1/AMPK family of protein kinases, there are no known Hunk substrates that have been identified to date. Recent work demonstrates a role for Hunk in HER2 + /ErbB2 + breast cancer progression, including drug resistance to HER2/ErbB2 inhibitors, with Hunk potentially acting downstream of HER2/ErbB2 and the PI3K/Akt pathway. These studies have collectively shown that Hunk plays a vital role in promoting mammary tumorigenesis, as Hunk knockdown via shRNA in xenograft tumor models or crossing MMTV-neu or Pten-deficient genetically engineered mouse models into a Hunk knockout (Hunk-/-) background impairs mammary tumor growth in vivo. Because the majority of HER2 + /ErbB2 + breast cancer patients acquire drug resistance to HER2/ErbB2 inhibitors, the characterization of novel drug targets like Hunk that have the potential to simultaneously suppress tumorigenesis and potentially enhance efficacy of current therapeutics is an important facet of drug development. Therefore, work aimed at uncovering specific regulatory functions for Hunk that could contribute to this protein kinase's role in both tumorigenesis and drug resistance will be informative. This review focuses on what is currently known about this under-studied protein kinase, and how targeting Hunk may prove to be a potential therapeutic target for the treatment of breast cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

Guanylyl Cyclase C Hormone Axis at the Intersection of Obesity and Colorectal Cancer.

PubMed

Blomain, Erik S; Merlino, Dante J; Pattison, Amanda M; Snook, Adam E; Waldman, Scott A

2016-09-01

Obesity has emerged as a principal cause of mortality worldwide, reflecting comorbidities including cancer risk, particularly in colorectum. Although this relationship is established epidemiologically, molecular mechanisms linking colorectal cancer and obesity continue to be refined. Guanylyl cyclase C (GUCY2C), a membrane-bound guanylyl cyclase expressed in intestinal epithelial cells, binds the paracrine hormones guanylin and uroguanylin, inducing cGMP signaling in colorectum and small intestine, respectively. Guanylin is the most commonly lost gene product in sporadic colorectal cancer, and its universal loss early in transformation silences GUCY2C, a tumor suppressor, disrupting epithelial homeostasis underlying tumorigenesis. In small intestine, eating induces endocrine secretion of uroguanylin, the afferent limb of a novel gut-brain axis that activates hypothalamic GUCY2C-cGMP signaling mediating satiety opposing obesity. Recent studies revealed that diet-induced obesity suppressed guanylin and uroguanylin expression in mice and humans. Hormone loss reflects reversible calorie-induced endoplasmic reticulum stress and the associated unfolded protein response, rather than the endocrine, adipokine, or inflammatory milieu of obesity. Loss of intestinal uroguanylin secretion silences the hypothalamic GUCY2C endocrine axis, creating a feed-forward loop contributing to hyperphagia in obesity. Importantly, calorie-induced guanylin loss silences the GUCY2C-cGMP paracrine axis underlying obesity-induced epithelial dysfunction and colorectal tumorigenesis. Indeed, genetically enforced guanylin replacement eliminated diet-induced intestinal tumorigenesis in mice. Taken together, these observations suggest that GUCY2C hormone axes are at the intersection of obesity and colorectal cancer. Moreover, they suggest that hormone replacement that restores GUCY2C signaling may be a novel therapeutic paradigm to prevent both hyperphagia and intestinal tumorigenesis in obesity. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Guanylyl Cyclase C Hormone Axis at the Intersection of Obesity and Colorectal Cancer

PubMed Central

Blomain, Erik S.; Merlino, Dante J.; Pattison, Amanda M.; Snook, Adam E.

2016-01-01

Obesity has emerged as a principal cause of mortality worldwide, reflecting comorbidities including cancer risk, particularly in colorectum. Although this relationship is established epidemiologically, molecular mechanisms linking colorectal cancer and obesity continue to be refined. Guanylyl cyclase C (GUCY2C), a membrane-bound guanylyl cyclase expressed in intestinal epithelial cells, binds the paracrine hormones guanylin and uroguanylin, inducing cGMP signaling in colorectum and small intestine, respectively. Guanylin is the most commonly lost gene product in sporadic colorectal cancer, and its universal loss early in transformation silences GUCY2C, a tumor suppressor, disrupting epithelial homeostasis underlying tumorigenesis. In small intestine, eating induces endocrine secretion of uroguanylin, the afferent limb of a novel gut-brain axis that activates hypothalamic GUCY2C-cGMP signaling mediating satiety opposing obesity. Recent studies revealed that diet-induced obesity suppressed guanylin and uroguanylin expression in mice and humans. Hormone loss reflects reversible calorie-induced endoplasmic reticulum stress and the associated unfolded protein response, rather than the endocrine, adipokine, or inflammatory milieu of obesity. Loss of intestinal uroguanylin secretion silences the hypothalamic GUCY2C endocrine axis, creating a feed-forward loop contributing to hyperphagia in obesity. Importantly, calorie-induced guanylin loss silences the GUCY2C-cGMP paracrine axis underlying obesity-induced epithelial dysfunction and colorectal tumorigenesis. Indeed, genetically enforced guanylin replacement eliminated diet-induced intestinal tumorigenesis in mice. Taken together, these observations suggest that GUCY2C hormone axes are at the intersection of obesity and colorectal cancer. Moreover, they suggest that hormone replacement that restores GUCY2C signaling may be a novel therapeutic paradigm to prevent both hyperphagia and intestinal tumorigenesis in obesity. PMID:27251363

Agouti signaling protein stimulates cell division in "viable yellow" (A vy/a) mouse liver

USDA-ARS?s Scientific Manuscript database

Enhanced linear growth, hyperplasia, and tumorigenesis are well-known characteristics of "viable yellow" agouti Avy/- mice (1); however, the functional basis for this aspect of the phenotype is unknown. In the present study, we ascertained whether agouti signaling protein (ASIP) levels in Avy/a or a...

Uniform cell-autonomous tumorigenesis of the choroid plexus by papovavirus large T antigens.

PubMed Central

Chen, J D; Van Dyke, T

1991-01-01

The simian virus 40 (SV40) large tumor antigen (T antigen) under its natural regulatory elements induces choroid plexus papillomas in transgenic mice. Because these tumors develop focally after several months, it has been suggested that secondary cellular alterations are required to induce a tumor in this tissue. In contrast to SV40, the related lymphotropic papovavirus early region induces rapid nonfocal choroid plexus neoplasia in transgenic mice. Here, using hybrid gene constructs, we showed that T antigen from either virus in in fact sufficient to induce these tumors. Their abilities to induce proliferative abnormalities in other tissues, such as kidney and thymus, were also indistinguishable. Differences in the rate of choroid plexus tumorigenesis reflected differences in the control regions of the two viruses, rather than differences in T antigen per se. Under SV40 regulation, expression was limited to a fraction of the choroid plexus cells prior to the formation of focal tumors. When SV40 T antigen was placed under lymphotropic papovavirus control, in contrast, expression was generally uniform in the choroid plexus and rapid expansion of the tissue ensued. We found a direct relationship between T-antigen expression, morphological transformation, and proliferation of the choroid plexus epithelial cells. Analysis of mosaic transgenic mice indicated further that T antigen exerts its mitogenic effect cell autonomously. These studies form the foundation for elucidating the role of various T-antigen subactivities in tumorigenesis. Images PMID:1658622

Ras-related tumorigenesis is suppressed by BNIP3-mediated autophagy through inhibition of cell proliferation.

PubMed

Wu, Shan-Ying; Lan, Sheng-Hui; Cheng, Da-En; Chen, Wei-Kai; Shen, Cheng-Huang; Lee, Ying-Ray; Zuchini, Roberto; Liu, Hsiao-Sheng

2011-12-01

Autophagy plays diverse roles in Ras-related tumorigenesis. H-ras(val12) induces autophagy through multiple signaling pathways including Raf-1/ERK pathway, and various ERK downstream molecules of autophagy have been reported. In this study, Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) is identified as a downstream transducer of the Ras/Raf/ERK signaling pathway to induce autophagy. BNIP3 was upregulated by H-ras(val12) at the transcriptional level to compete with Beclin 1 for binding with Bcl-2. H-ras(val12)-induced autophagy suppresses cell proliferation demonstrated both in vitro and in vivo by expression of ectopic BNIP3, Atg5, or interference RNA of BNIP3 (siBNIP3) and Atg5 (shAtg5) using mouse NIH3T3 and embryo fibroblast cells. H-ras(val12) induces different autophagic responses depending on the duration of Ras overexpression. After a short time (48 hours) of Ras overexpression, autophagy inhibits cell proliferation. In contrast, a longer time (2 weeks) of Ras overexpression, cell proliferation was enhanced by autophagy. Furthermore, overexpression of mutant Ras, BNIP3, and LC3-II was detected in bladder cancer T24 cells and the tumor parts of 75% of bladder cancer specimens indicating a positive correlation between autophagy and tumorigenesis. Taken together, our mouse model demonstrates a balance between BNIP3-mediated autophagy and H-ras(val12)-induced tumor formation and reveals that H-ras(val12) induces autophagy in a BNIP3-dependent manner, and the threshold of autophagy plays a decisive role in H-ras(val12)-induced tumorigenesis. Our findings combined with others' reports suggest a new therapeutic strategy against Ras-related tumorigenesis by negative or positive regulation of autophagic activity, which is determined by the level of autophagy and tumor progression stages.

Necroptosis in tumorigenesis, activation of anti-tumor immunity, and cancer therapy

PubMed Central

Wu, Zhi-Qiang; Shi, Yang-Yang; Zaorsky, Nicholas G.; Deng, Lei; Yuan, Zhi-Yong; Lu, You; Wang, Ping

2016-01-01

While the mechanisms underlying apoptosis and autophagy have been well characterized over recent decades, another regulated cell death event, necroptosis, remains poorly understood. Elucidating the signaling networks involved in the regulation of necroptosis may allow this form of regulated cell death to be exploited for diagnosis and treatment of cancer, and will contribute to the understanding of the complex tumor microenvironment. In this review, we have summarized the mechanisms and regulation of necroptosis, the converging and diverging features of necroptosis in tumorigenesis, activation of anti-tumor immunity, and cancer therapy, as well as attempts to exploit this newly gained knowledge to provide therapeutics for cancer. PMID:27429198

A zebrafish transgenic model of Ewing's sarcoma reveals conserved mediators of EWS-FLI1 tumorigenesis.

PubMed

Leacock, Stefanie W; Basse, Audrey N; Chandler, Garvin L; Kirk, Anne M; Rakheja, Dinesh; Amatruda, James F

2012-01-01

Ewing's sarcoma, a malignant bone tumor of children and young adults, is a member of the small-round-blue-cell tumor family. Ewing's sarcoma family tumors (ESFTs), which include peripheral primitive neuroectodermal tumors (PNETs), are characterized by chromosomal translocations that generate fusions between the EWS gene and ETS-family transcription factors, most commonly FLI1. The EWS-FLI1 fusion oncoprotein represents an attractive therapeutic target for treatment of Ewing's sarcoma. The cell of origin of ESFT and the molecular mechanisms by which EWS-FLI1 mediates tumorigenesis remain unknown, and few animal models of Ewing's sarcoma exist. Here, we report the use of zebrafish as a vertebrate model of EWS-FLI1 function and tumorigenesis. Mosaic expression of the human EWS-FLI1 fusion protein in zebrafish caused the development of tumors with histology strongly resembling that of human Ewing's sarcoma. The incidence of tumors increased in a p53 mutant background, suggesting that the p53 pathway suppresses EWS-FLI1-driven tumorigenesis. Gene expression profiling of the zebrafish tumors defined a set of genes that might be regulated by EWS-FLI1, including the zebrafish ortholog of a crucial EWS-FLI1 target gene in humans. Stable zebrafish transgenic lines expressing EWS-FLI1 under the control of the heat-shock promoter exhibit altered embryonic development and defective convergence and extension, suggesting that EWS-FLI1 interacts with conserved developmental pathways. These results indicate that functional targets of EWS-FLI1 that mediate tumorigenesis are conserved from zebrafish to human and provide a novel context in which to study the function of this fusion oncogene.

Interaction of the Wnt/β-catenin and RAS-ERK pathways involving co-stabilization of both β-catenin and RAS plays important roles in the colorectal tumorigenesis.

PubMed

Lee, Sang-Kyu; Hwang, Jeong-Ha; Choi, Kang-Yell

2018-05-01

Cancer development is usually driven by multiple genetic and molecular alterations rather than by a single defect. In the human colorectal cancer (CRC), series of mutations of genes are involved in the different stages of tumorigenesis. For example, adenomatous polyposis coli (APC) and KRAS mutations have been known to play roles in the initiation and progression of the tumorigenesis, respectively. However, many studies indicate that mutations of these two genes, which play roles in the Wnt/β-catenin and RAS-extra-cellular signal regulated kinase (ERK) pathways, respectively, cooperatively interact in the tumorigenesis in several different cancer types including CRC. Both Apc and Kras mutations critically increase number and growth rate of tumors although single mutation of these genes does not significantly enhance the small intestinal tumorigenesis of mice. Both APC and KRAS mutations even result in the liver metastasis with inductions of the cancer stem cells (CSCs) markers in a mice xenograft model. In this review, we are going to describe the history for interaction between the Wnt/β-catenin and RAS/ERK pathways especially related with CRC, and provide the mechanical basis for the cross-talk between the two pathways. The highlight of the crosstalk involving the stability regulation of RAS protein via the Wnt/β-catenin signaling which is directly related with the cellular proliferation and transformation will be discussed. Activation status of GSK3β, a key enzyme involving both β-catenin and RAS degradations, is regulated by the status of the Wnt/β-catenin signaling dependent upon extracellular stimuli or intracellular abnormalities of the signaling components. The levels of both β-catenin and RAS proteins are co-regulated by the Wnt/β-catenin signaling, and these proteins are overexpressed with a positive correlation in the tumor tissues of CRC patients. These results indicate that the elevation of both β-catenin and RAS proteins is pathologically significant in CRC. In this review, we also will discuss further involvement of the increments of both β-catenin and RAS especially mutant KRAS in the activation of CSCs and metastasis. Overall, the increments of β-catenin and RAS especially mutant KRAS by APC loss play important roles in the cooperative tumorigenesis of CRC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Overexpression of SKI Oncoprotein Leads to p53 Degradation through Regulation of MDM2 Protein Sumoylation*

PubMed Central

Ding, Boxiao; Sun, Yin; Huang, Jiaoti

2012-01-01

Protooncogene Ski was identified based on its ability to transform avian fibroblasts in vitro. In support of its oncogenic activity, SKI was found to be overexpressed in a variety of human cancers, although the exact molecular mechanism(s) responsible for its oncogenic activity is not fully understood. We found that SKI can negatively regulate p53 by decreasing its level through up-regulation of MDM2 activity, which is mediated by the ability of SKI to enhance sumoylation of MDM2. This stimulation of MDM2 sumoylation is accomplished through a direct interaction of SKI with SUMO-conjugating enzyme E2, Ubc9, resulting in enhanced thioester bond formation and mono-sumoylation of Ubc9. A mutant SKI defective in transformation fails to increase p53 ubiquitination and is unable to increase MDM2 levels and to increase mono-sumoylation of Ubc9, suggesting that the ability of SKI to enhance Ubc9 activity is essential for its transforming function. These results established a detailed molecular mechanism that underlies the ability of SKI to cause cellular transformation while unraveling a novel connection between sumoylation and tumorigenesis, providing potential new therapeutic targets for cancer. PMID:22411991

Pachymic Acid Sensitizes Gastric Cancer Cells to Radiation Therapy by Upregulating Bax through Hypoxia.

PubMed

Lu, Chunwei; Cai, Dingfang; Ma, Jun

2018-05-08

We have previously shown that pachymic acid (PA) inhibited tumorigenesis of gastric cancer (GC) cells. However, the exact mechanism underlying the radiation response of GC was still elusive. To evaluate the effects of PA treatment on radiation response of GC cell lines both in vitro and in vivo, a colony formation assay and xenograft mouse model were employed. Changes in Bax and HIF1[Formula: see text] expressions were assessed in GC cells following PA treatment. Luciferase reporter and chromatin immune-precipitation assays were carried out to investigate the regulation of Bax through HIF1[Formula: see text]. Stable HIF1[Formula: see text] knockdown was introduced into GC cells to further study the mechanism underlying PA-enhanced response to radiation both in vitro and in vivo. PA greatly enhanced the sensitivity of GC cells to radiation in vitro and in vivo, upregulated Bax expression and inhibited hypoxia. Bax expression was under hypoxia inhibition, and PA increased Bax expression through repressing HIF1[Formula: see text]. Stable HIF1[Formula: see text] overexpression in GC cells abolished the sensitizing effect of PA on GC cells to radiation both in vitro and in vivo. PA functions as a radiation sensitizing compound in GC. PA treatment induces the expression of pro-apoptotic factor Bax by inhibiting hypoxia/HIF1[Formula: see text], supporting the therapeutic potential of PA in radiation therapy against GC.

Histone demethylase JMJD2B is required for tumor cell proliferation and survival and is overexpressed in gastric cancer

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

Li, Wenjuan; Zhao, Li; Zang, Wen

2011-12-16

Highlights: Black-Right-Pointing-Pointer JMJD2B is required for cell proliferation and in vivo tumorigenesis. Black-Right-Pointing-Pointer JMJD2B depletion induces apoptosis and/or cell cycle arrest. Black-Right-Pointing-Pointer JMJD2B depletion activates DNA damage response and enhances p53 stabilization. Black-Right-Pointing-Pointer JMJD2B is overexpressed in human primary gastric cancer. -- Abstract: Epigenetic alterations such as aberrant expression of histone-modifying enzymes have been implicated in tumorigenesis. Jumonji domain containing 2B (JMJD2B) is a newly identified histone demethylase that regulates chromatin structure or gene expression by removing methyl residues from trimethylated lysine 9 on histone H3. Recent observations have shown oncogenic activity of JMJD2B. We explored the functional role ofmore » JMJD2B in cancer cell proliferation, survival and tumorigenesis, and determined its expression profile in gastric cancer. Knocking down JMJD2B expression by small interfering RNA (siRNA) in gastric and other cancer cells inhibited cell proliferation and/or induced apoptosis and elevated the expression of p53 and p21{sup CIP1} proteins. The enhanced p53 expression resulted from activation of the DNA damage response pathway. JMJD2B knockdown markedly suppressed xenograft tumor growth in vivo in mice. Moreover, JMJD2B expression was increased in primary gastric-cancer tissues of humans. Thus, JMJD2B is required for sustained proliferation and survival of tumor cells in vitro and in vivo, and its aberrant expression may contribute to the pathogenesis of gastric cancer.« less

Dual role of the integrated stress response in medulloblastoma tumorigenesis

PubMed Central

Li, Xiting; Jamison, Stephanie; Harding, Heather P.; Ron, David; Lin, Wensheng

2016-01-01

In response to endoplasmic reticulum (ER) stress, activation of pancreatic ER kinase (PERK) coordinates an adaptive program known as the integrated stress response (ISR) by phosphorylating translation initiation factor 2α (eIF2α). Phosphorylated eIF2α is quickly dephosphorylated by the protein phosphatase 1 and growth arrest and DNA damage 34 (GADD34) complex. Data indicate that the ISR can either promote or suppress tumor development. Our previous studies showed that the ISR is activated in medulloblastoma in both human patients and animal models, and that the decreased ISR via PERK heterozygous deficiency attenuates medulloblastoma formation in Patched1 heterozygous deficient (Ptch1+/−) mice by enhancing apoptosis of pre-malignant granule cell precursors (GCPs) during cell transformation. We showed here that GADD34 heterozygous mutation moderately enhanced the ISR and noticeably increased the incidence of medulloblastoma in adult Ptch1+/− mice. Surprisingly, GADD34 homozygous mutation strongly enhanced the ISR, but significantly decreased the incidence of medulloblastoma in adult Ptch1+/− mice. Intriguingly, GADD34 homozygous mutation significantly enhanced pre-malignant GCP apoptosis in cerebellar hyperplastic lesions and reduced the lesion numbers in young Ptch1+/− mice. Nevertheless, neither GADD34 heterozygous mutation nor GADD34 homozygous mutation had a significant effect on medulloblastoma cells in adult Ptch1+/− mice. Collectively, these data imply the dual role of the ISR, promoting and inhibiting, in medulloblastoma tumorigenesis by regulating apoptosis of pre-malignant GCPs during the course of malignant transformation. PMID:27802424

Dual role of the integrated stress response in medulloblastoma tumorigenesis.

PubMed

Stone, Sarrabeth; Ho, Yeung; Li, Xiting; Jamison, Stephanie; Harding, Heather P; Ron, David; Lin, Wensheng

2016-09-27

In response to endoplasmic reticulum (ER) stress, activation of pancreatic ER kinase (PERK) coordinates an adaptive program known as the integrated stress response (ISR) by phosphorylating translation initiation factor 2α (eIF2α). Phosphorylated eIF2α is quickly dephosphorylated by the protein phosphatase 1 and growth arrest and DNA damage 34 (GADD34) complex. Data indicate that the ISR can either promote or suppress tumor development. Our previous studies showed that the ISR is activated in medulloblastoma in both human patients and animal models, and that the decreased ISR via PERK heterozygous deficiency attenuates medulloblastoma formation in Patched1 heterozygous deficient (Ptch1+/-) mice by enhancing apoptosis of pre-malignant granule cell precursors (GCPs) during cell transformation. We showed here that GADD34 heterozygous mutation moderately enhanced the ISR and noticeably increased the incidence of medulloblastoma in adult Ptch1+/- mice. Surprisingly, GADD34 homozygous mutation strongly enhanced the ISR, but significantly decreased the incidence of medulloblastoma in adult Ptch1+/- mice. Intriguingly, GADD34 homozygous mutation significantly enhanced pre-malignant GCP apoptosis in cerebellar hyperplastic lesions and reduced the lesion numbers in young Ptch1+/- mice. Nevertheless, neither GADD34 heterozygous mutation nor GADD34 homozygous mutation had a significant effect on medulloblastoma cells in adult Ptch1+/- mice. Collectively, these data imply the dual role of the ISR, promoting and inhibiting, in medulloblastoma tumorigenesis by regulating apoptosis of pre-malignant GCPs during the course of malignant transformation.

The role of BRCA1 in homologous recombination repair in response to replication stress: significance in tumorigenesis and cancer therapy

PubMed Central

2013-01-01

Germ line mutations in breast cancer gene 1 (BRCA1) predispose women to breast and ovarian cancers. Although BRCA1 is involved in many important biological processes, the function of BRCA1 in homologous recombination (HR) mediated repair is considered one of the major mechanisms contributing to its tumor suppression activity, and the cause of hypersensitivity to poly(ADP-ribose) polymerase (PARP) inhibitors when BRCA1 is defective. Mounting evidence suggests that the mechanism of repairing DNA double strand breaks (DSBs) by HR is different than the mechanism operating when DNA replication is blocked. Although BRCA1 has been recognized as a central component in HR, the precise role of BRCA1 in HR, particularly under replication stress, has remained largely unknown. Given the fact that DNA lesions caused by replication blockages are the primary substrates for HR in mitotic cells, functional analysis of BRCA1 in HR repair in the context of replication stress should benefit our understanding of the molecular mechanisms underlying tumorigenesis associated with BRCA1 deficiencies, as well as the development of therapeutic approaches for cancer patients carrying BRCA1 mutations or reduced BRCA1 expression. This review focuses on the current advances in this setting and also discusses the significance in tumorigenesis and cancer therapy. PMID:23388117

Camptosorus sibiricus rupr aqueous extract prevents lung tumorigenesis via dual effects against ROS and DNA damage.

PubMed

He, Shugui; Ou, Rilan; Wang, Wensheng; Ji, Liyan; Gao, Hui; Zhu, Yuanfeng; Liu, Xiaomin; Zheng, Hongming; Liu, Zhongqiu; Wu, Peng; Lu, Linlin

2018-06-28

Camptosorus sibiricus Rupr (CSR) is a widely used herbal medicine with antivasculitis, antitrauma, and antitumor effects. However, the effect of CSR aqueous extract on B[a]P-initiated tumorigenesis and the underlying mechanism remain unclear. Moreover, the compounds in CSR aqueous extract need to be identified and structurally characterized. We aim to investigate the chemopreventive effect of CSR and the underlying molecular mechanism. A B[a]P-stimulated normal cell model (BEAS.2B) and lung adenocarcinoma animal model were established on A/J mice. In B[a]P-treated BEAS.2B cells, the protective effects of CSR aqueous extract on B[a]P-induced DNA damage and ROS production were evaluated through flow cytometry, Western blot, real-time quantitative PCR, single-cell gel electrophoresis, and immunofluorescence. Moreover, a model of B[a]P-initiated lung adenocarcinoma was established on A/J mice to determine the chemopreventive effect of CSR in vivo. The underlying mechanism was analyzed via immunohistochemistry and microscopy. Furthermore, the new compounds in CSR aqueous extract were isolated and structurally characterized using IR, HR-ESI-MS, and 1D and 2D NMR spectroscopy. CSR effectively suppressed ROS production by re-activating Nrf2-mediated reductases HO-1 and NQO-1. Simultaneously, CSR attenuated the DNA damage of BEAS.2B cells in the presence of B[a]P. Moreover, CSR at 1.5 and 3 g/kg significantly suppressed tumorigenesis with tumor inhibition ratios of 36.65% and 65.80%, respectively. The tumor volume, tumor size, and multiplicity of B[a]P-induced lung adenocarcinoma were effectively decreased by CSR in vivo. After extracting and identifying the compounds in CSR aqueous extract, three new triterpene saponins were isolated and characterized structurally. CSR aqueous extract prevents lung tumorigenesis by exerting dual effects against ROS and DNA damage, suggesting that CSR is a novel and effective agent for B[a]P-induced carcinogenesis. Moreover, by isolating and structurally characterizing three new triterpene saponins, our study further standardized the quality of CSR aqueous extract, which could widen CSR clinical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

DcR3 induces epithelial-mesenchymal transition through activation of the TGF-β3/SMAD signaling pathway in CRC.

PubMed

Liu, Yan-Ping; Zhu, Hui-Fang; Liu, Ding-Li; Hu, Zhi-Yan; Li, Sheng-Nan; Kan, He-Ping; Wang, Xiao-Yan; Li, Zu-Guo

2016-11-22

Decoy receptor 3 (DcR3), a novel member of the tumor necrosis factor receptor (TNFR) family, was recently reported to be associated with tumorigenesis and metastasis. However, the role of DcR3 in human colorectal cancer (CRC) has not been fully elucidated. In this study, we found that DcR3 expression was significantly higher in human colorectal cancer tissues than in paired normal tissues, and that DcR3 expression was strongly correlated with tumor invasion, lymph node metastases and poor prognoses. Moreover, DcR3 overexpression significantly enhanced CRC cell proliferation and migration in vitro and tumorigenesis in vivo. Conversely, DcR3 knockdown significantly repressed CRC cell proliferation and migration in vitro, and DcR3 deficiency also attenuated CRC tumorigenesis and metastasis in vivo. Functionally, DcR3 was essential for TGF-β3/SMAD-mediated epithelial-mesenchymal transition (EMT) of CRC cells. Importantly, cooperation between DcR3 and TGF-β3/SMAD-EMT signaling-related protein expression was correlated with survival and survival time in CRC patients. In conclusion, our results demonstrate that DcR3 may be a prognostic biomarker for CRC and that this receptor facilitates CRC development and metastasis by participating in TGF-β3/SMAD-mediated EMT of CRC cells.

Claudin-18-mediated YAP activity regulates lung stem and progenitor cell homeostasis and tumorigenesis.

PubMed

Zhou, Beiyun; Flodby, Per; Luo, Jiao; Castillo, Dan R; Liu, Yixin; Yu, Fa-Xing; McConnell, Alicia; Varghese, Bino; Li, Guanglei; Chimge, Nyam-Osor; Sunohara, Mitsuhiro; Koss, Michael N; Elatre, Wafaa; Conti, Peter; Liebler, Janice M; Yang, Chenchen; Marconett, Crystal N; Laird-Offringa, Ite A; Minoo, Parviz; Guan, Kunliang; Stripp, Barry R; Crandall, Edward D; Borok, Zea

2018-03-01

Claudins, the integral tight junction (TJ) proteins that regulate paracellular permeability and cell polarity, are frequently dysregulated in cancer; however, their role in neoplastic progression is unclear. Here, we demonstrated that knockout of Cldn18, a claudin family member highly expressed in lung alveolar epithelium, leads to lung enlargement, parenchymal expansion, increased abundance and proliferation of known distal lung progenitors, the alveolar epithelial type II (AT2) cells, activation of Yes-associated protein (YAP), increased organ size, and tumorigenesis in mice. Inhibition of YAP decreased proliferation and colony-forming efficiency (CFE) of Cldn18-/- AT2 cells and prevented increased lung size, while CLDN18 overexpression decreased YAP nuclear localization, cell proliferation, CFE, and YAP transcriptional activity. CLDN18 and YAP interacted and colocalized at cell-cell contacts, while loss of CLDN18 decreased YAP interaction with Hippo kinases p-LATS1/2. Additionally, Cldn18-/- mice had increased propensity to develop lung adenocarcinomas (LuAd) with age, and human LuAd showed stage-dependent reduction of CLDN18.1. These results establish CLDN18 as a regulator of YAP activity that serves to restrict organ size, progenitor cell proliferation, and tumorigenesis, and suggest a mechanism whereby TJ disruption may promote progenitor proliferation to enhance repair following injury.

The regulation of inflammatory pathways and infectious disease of the cervix by seminal fluid.

PubMed

Adefuye, Anthonio; Katz, Arieh Anthony; Sales, Kurt Jason

2014-01-01

The connection between human papillomavirus (HPV) infection and the consequent sequelae which establishes cervical neoplastic transformation and invasive cervical cancer has redefined many aspects of cervical cancer research. However there is still much that we do not know. In particular, the impact of external factors, like seminal fluid in sexually active women, on pathways that regulate cervical inflammation and tumorigenesis, have yet to be fully understood. HPV infection is regarded as the initiating noninflammatory cause of the disease; however emerging evidence points to resident HPV infections as drivers of inflammatory pathways that play important roles in tumorigenesis as well as in the susceptibility to other infections such as human immunodeficiency virus (HIV) infection. Moreover there is emerging evidence to support a role for seminal fluid, in particular, the inflammatory bioactive lipids, and prostaglandins which are present in vast quantities in seminal fluid in regulating pathways that can exacerbate inflammation of the cervix, speed up tumorigenesis, and enhance susceptibility to HIV infection. This review will highlight some of our current knowledge of the role of seminal fluid as a potent driver of inflammatory and tumorigenic pathways in the cervix and will provide some evidence to propose a role for seminal plasma prostaglandins in HIV infection and AIDS-related cancer.

The Regulation of Inflammatory Pathways and Infectious Disease of the Cervix by Seminal Fluid

PubMed Central

Katz, Arieh Anthony

2014-01-01

The connection between human papillomavirus (HPV) infection and the consequent sequelae which establishes cervical neoplastic transformation and invasive cervical cancer has redefined many aspects of cervical cancer research. However there is still much that we do not know. In particular, the impact of external factors, like seminal fluid in sexually active women, on pathways that regulate cervical inflammation and tumorigenesis, have yet to be fully understood. HPV infection is regarded as the initiating noninflammatory cause of the disease; however emerging evidence points to resident HPV infections as drivers of inflammatory pathways that play important roles in tumorigenesis as well as in the susceptibility to other infections such as human immunodeficiency virus (HIV) infection. Moreover there is emerging evidence to support a role for seminal fluid, in particular, the inflammatory bioactive lipids, and prostaglandins which are present in vast quantities in seminal fluid in regulating pathways that can exacerbate inflammation of the cervix, speed up tumorigenesis, and enhance susceptibility to HIV infection. This review will highlight some of our current knowledge of the role of seminal fluid as a potent driver of inflammatory and tumorigenic pathways in the cervix and will provide some evidence to propose a role for seminal plasma prostaglandins in HIV infection and AIDS-related cancer. PMID:25180120

Inhibitor of Differentiation/DNA Binding 1 (ID1) Inhibits Etoposide-induced Apoptosis in a c-Jun/c-Fos-dependent Manner.

PubMed

Zhao, Yahui; Luo, Aiping; Li, Sheng; Zhang, Wei; Chen, Hongyan; Li, Yi; Ding, Fang; Huang, Furong; Liu, Zhihua

2016-03-25

ID1 (inhibitor of differentiation/DNA binding 1) acts an important role in metastasis, tumorigenesis, and maintenance of cell viability. It has been shown that the up-regulation of ID1 is correlated with poor prognosis and the resistance to chemotherapy of human cancers. However, the underlying molecular mechanism remains elusive. Here, we determined for the first time that up-regulating ID1 upon etoposide activation was mediated through AP-1 binding sites within theID1promoter and confirmed that ID1 enhanced cell resistance to DNA damage-induced apoptosis in esophageal squamous cell carcinoma cells. Ablation of c-Jun/c-Fos or ID1 expression enhanced etoposide-mediated apoptosis through increasing activity of caspase 3 and PARP cleavage. Moreover, c-Jun/c-Fos and ID1 were positively correlated in human cancers. More importantly, simultaneous high expression of ID1 and c-Jun or c-Fos was correlated with poor survival in cancer patients. Collectively, we demonstrate the importance of c-Jun/c-Fos-ID1 signaling pathway in chemoresistance of esophageal cancer cells and provide considerable insight into understanding the underlying molecular mechanisms in esophageal squamous cell carcinoma cell biology. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Progesterone regulation of stem and progenitor cells in normal and malignant breast

PubMed Central

Axlund, Sunshine Daddario; Sartorius, Carol A.

2011-01-01

Progesterone plays an important, if not controversial, role in mammary epithelial cell proliferation and differentiation. Evidence supports that progesterone promotes rodent mammary carcinogenesis under some conditions, progesterone receptors (PR) are necessary for murine mammary gland tumorigenesis, and exogenous progestin use in post-menopausal women increases breast cancer risk. Thus, the progesterone/PR signaling axis can promote mammary tumorigenesis, albeit in a context dependent manner. A mechanistic basis for the tumor promoting actions of progesterone has thus far remained unknown. Recent studies, however, have identified a novel role for progesterone in controlling the number and function of stem and progenitor cell populations in the normal human and mouse mammary glands, and in human breast cancers. These discoveries promise to reshape our perception of progesterone function in the mammary gland, and have spawned new hypotheses for how progestins may increase the risk of breast cancer. Here we review studies on progesterone regulation of mammary stem cells in normal and malignant tissue, and their implications for breast cancer risk, tumorigenesis, and tumor behavior. PMID:21945473

Initiation-promotion skin carcinogenesis and immunological competence.

PubMed

Curtis, G L; Stenbäck, F; Ryan, W L

1975-10-01

The immune competence of mice during initiation-promotion skin carcinogenesis was determined by skin allograft rejection and lymphocyte mitogenesis. The carcinogen 7, 12-dimethylbenzanthracene inhibited the cellular immune competence of mice while lymphocytes from croton oil treated mice had enhanced PWM response. Chlorphenesin, a stimulator of cellular immunity, was found to inhibit tumorigenesis in initiation-promotion skin carcinogenesis when injected during promotion.

Environmental Estrogens Differentially Engage the Histone Methyltransferase EZH2 to Increase Risk of Uterine Tumorigenesis

PubMed Central

Greathouse, K. Leigh; Bredfeldt, Tiffany; Everitt, Jeffrey I.; Lin, Kevin; Berry, Tia; Kannan, Kurunthachalam; Mittelstadt, Megan L.; Ho, Shuk-mei; Walker, Cheryl L.

2013-01-01

Environmental exposures during sensitive windows of development can reprogram normal physiological responses and alter disease susceptibility later in life in a process known as developmental reprogramming. For example, exposure to the xenoestrogen diethylstilbestrol (DES) during reproductive tract development can reprogram estrogen-responsive gene expression in the myometrium, resulting in hyper-responsiveness to hormone in the adult uterus and promotion of hormone-dependent uterine leiomyoma. We show here that the environmental estrogens genistein (GEN), a soy phytoestrogen, and the plasticizer bisphenol A (BPA), differ in their pattern of developmental reprogramming and promotion of tumorigenesis (leiomyomas) in the uterus. While both GEN and BPA induce genomic estrogen receptor (ER) signaling in the developing uterus, only GEN induced PI3K/AKT non-genomic ER signaling to the histone methyltransferase Enhancer of Zeste homolog 2 (EZH2). As a result, this “pre-genomic” signaling phosphorylates and represses EZH2, and reduces levels of H3K27 repressive mark in chromatin. Furthermore, only GEN caused estrogen-responsive genes in the adult myometrium to become hyper-responsive to hormone; estrogen-responsive genes were repressed in BPA exposed uteri. Importantly, this pattern of EZH2 engagement to decrease versus increase H3K27 methylation correlated with the effect of these xenoestrogens on tumorigenesis. Developmental reprogramming by GEN promoted development of uterine leiomyomas, increasing tumor incidence and multiplicity, while BPA did not. These data demonstrate that environmental estrogens have distinct non-genomic effects in the developing uterus that determines their ability to engage the epigenetic regulator EZH2, decrease levels of the repressive epigenetic histone H3K27 methyl mark in chromatin during developmental reprogramming, and promote uterine tumorigenesis. PMID:22504913

RNA-Sequencing studies identify genes differentially regulated during inflammation-driven lung tumorigenesis and targeted by chemopreventive agents

PubMed Central

Qian, Xuemin; Khammanivong, Ali; Song, Jung Min; Teferi, Fitsum; Upadhyaya, Pramod; Dickerson, Erin; Kassie, Fekadu

2016-01-01

Chronic pulmonary inflammation has been consistently shown to increase the risk of lung cancer. Therefore, assessing the molecular links between the two diseases and identification of chemopreventive agents that inhibit inflammation-driven lung tumorigenesis is indispensable. Recently, we found that 4-(methylnitro-samino)-1-(3-pyridyl)-1-butanone (NNK)-induced mouse lung tumorigenesis was significantly enhanced by chronic treatment with the inflammatory agents lipopolysaccharide (LPS) and combinatory treatment with the chemoprevenitve agents silibinin (Sil) and indole-3-carbinol (I3C) significantly inhibited the burden of inflammation-driven lung tumors. In this report, we described gene expression profiling of lung tissues derived from these studies to determine the gene expression signature in inflammation-driven lung tumors and modulation of this signature by the chemopreventive agents Sil and I3C. We found that 330, 2,957, and 1,143 genes were differentially regulated in mice treated with NNK, LPS, and NNK + LPS, respectively. The inflammatory response of lung tumors to LPS, as determined by the number of proinflammatory genes with altered gene expression or the level of alteration, was markedly less than that of normal lungs. Among 1,143 genes differentially regulated in the NNK + LPS group, the expression of 162 genes and associated signaling pathways were significantly modulated by I3C and/or Sil + I3C. These genes include cytokines, chemokines, putative oncogenes and tumor suppressor genes and Ros1, AREG, EREG, Cyp1a1, Arntl, and Npas2. To our knowledge, this is the first report that provides insight into genes that are differentially expressed during inflammation-driven lung tumorigenesis and the modulation of these genes by chemopreventive agents. PMID:25795230

Combined inadequacies of multiple B vitamins amplify colonic Wnt signaling and promote intestinal tumorigenesis in BAT-LacZ×Apc1638N mice

PubMed Central

Liu, Zhenhua; Ciappio, Eric D.; Crott, Jimmy W.; Brooks, Ryan S.; Nesvet, Jared; Smith, Donald E.; Choi, Sang-Woon; Mason, Joel B.

2011-01-01

The Wnt pathway is a pivotal signaling cascade in colorectal carcinogenesis. The purpose of this work is to determine whether depletion of folate and other metabolically related B vitamins induces in vivo activation of intestinal Wnt signaling and whether this occurs in parallel with increased tumorigenesis. A hybrid mouse was created by crossing a Wnt-reporter animal (BAT-LacZ) with a model of colorectal cancer (Apc1638N). A mild depletion of folate and vitamins B2, B6, and B12 was induced over 16 wk, and the control animals in each instance were pair fed a diet containing the basal requirement of these nutrients. The multiplicity of macroscopic tumors and aberrant crypt foci both increased by ∼50% in the hybrid mice fed the depletion diet (P<0.05). A 4-fold elevation in Wnt signaling was produced by the depletion diet (P<0.05) and was accompanied by significant changes in the expression of a number of Wnt-related genes in a pattern consistent with its activation. Proliferation and apoptosis of the colonic mucosa both changed in a protransformational direction (P<0.05). In summary, mild depletion of multiple B vitamins produces in vivo activation of colonic Wnt signaling, implicating it as a key pathway by which B-vitamin inadequacies enhance intestinal tumorigenesis.—Liu, Z., Ciappio, E. D., Crott, J. W., Brooks, R. S., Nesvet, J., Smith, D. E., Choi, S.-W., Mason, J. B. Combined inadequacies of multiple B vitamins amplify colonic Wnt signaling and promote intestinal tumorigenesis in BAT-LacZ×Apc1638N mice. PMID:21646397

Phosphorylation of Nanog is Essential to Regulate Bmi1 and Promote Tumorigenesis

PubMed Central

Xie, Xiujie; Piao, Longzhu; Cavey, Greg S.; Old, Matthew; Teknos, Theodoros N.; Mapp, Anna K; Pan, Quintin

2014-01-01

Emerging evidence indicates that Nanog is intimately involved in tumorigenesis in part through regulation of the cancer initiating cell population. However, the regulation and role of Nanog in tumorigenesis are still poorly understood. In this study, human Nanog was identified to be phosphorylated by human PKCε at multiple residues including T200 and T280. Our work indicated that phosphorylation at T200 and T280 modulates Nanog function through several regulatory mechanisms. Results with phosphorylation-insensitive and phosphorylation-mimetic mutant Nanog revealed that phosphorylation at T200 and T280 enhance Nanog protein stability. Moreover, phosphorylation-insensitive T200A and T280A mutant Nanog had a dominant-negative function to inhibit endogenous Nanog transcriptional activity. Inactivation of Nanog was due to impaired homodimerization, DNA binding, promoter occupancy, and p300, a transcriptional co-activator, recruitment resulting in a defect in target gene promoter activation. Ectopic expression of phosphorylation-insensitive T200A or T280A mutant Nanog reduced cell proliferation, colony formation, invasion, migration, and the cancer initiating cell population in head and neck squamous cell carcinoma (HNSCC) cells. The in vivo cancer initiating ability was severely compromised in HNSCC cells expressing phosphorylation-insensitive T200A or T280A mutant Nanog; 87.5% (14/16), 12.5% (1/8), and 0% (0/8) for control, T200A, and T280A, respectively. Nanog occupied the Bmi1 promoter to directly transactivate and regulate Bmi1. Genetic ablation and rescue experiments demonstrated that Bmi1 is a critical downstream signaling node for the pleiotropic, pro-oncogenic effects of Nanog. Taken together, our study revealed, for the first time, that post-translational phosphorylation of Nanog is essential to regulate Bmi1 and promote tumorigenesis. PMID:23708658

Sex-dependent Differences in Intestinal Tumorigenesis Induced in Apc1638N/+ Mice by Exposure to {gamma} Rays

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

Trani, Daniela; Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia; Maastricht Radiation Oncology

Purpose: The purpose of the present study was to assess the effect of 1 and 5 Gy radiation doses and to investigate the interplay of gender and radiation with regard to intestinal tumorigenesis in an adenomatous polyposis coli (APC) mutant mouse model. Methods and Materials: Apc1638N/+ female and male mice were exposed whole body to either 1 Gy or 5 Gy of {gamma} rays and euthanized when most of the treated mice became moribund. Small and large intestines were processed to determine tumor burden, distribution, and grade. Expression of proliferation marker Ki-67 and estrogen receptor (ER)-{alpha} were also assessed bymore » immunohistochemistry. Results: We observed that, with both 1 Gy and 5 Gy of {gamma} rays, females displayed reduced susceptibility to radiation-induced intestinal tumorigenesis compared with males. As for radiation effect on small intestinal tumor progression, although no substantial differences were found in the relative frequency and degree of dysplasia of adenomas in irradiated animals compared with controls, invasive carcinomas were found in 1-Gy- and 5-Gy-irradiated animals. Radiation exposure was also shown to induce an increase in protein levels of proliferation marker Ki-67 and sex-hormone receptor ER-{alpha} in both non tumor mucosa and intestinal tumors from irradiated male mice. Conclusions: We observed important sex-dependent differences in susceptibility to radiation-induced intestinal tumorigenesis in Apc1638N/+ mutants. Furthermore, our data provide evidence that exposure to radiation doses as low as 1 Gy can induce a significant increase in intestinal tumor multiplicity as well as enhance tumor progression in vivo.« less

Protein Kinase D1 attenuates tumorigenesis in colon cancer by modulating β-catenin/T cell factor activity

PubMed Central

Sundram, Vasudha; Ganju, Aditya; Hughes, Joshua E.; Khan, Sheema; Chauhan, Subhash C.; Jaggi, Meena

2014-01-01

Over 80% of colon cancer development and progression is a result of the dysregulation of β-catenin signaling pathway. Herein, for the first time, we demonstrate that a serine-threonine kinase, Protein Kinase D1 (PKD1), modulates the functions of β-catenin to suppress colon cancer growth. Analysis of normal and colon cancer tissues reveals downregulation of PKD1 expression in advanced stages of colon cancer and its co-localization with β-catenin in the colon crypts. This PKD1 downregulation corresponds with the aberrant expression and nuclear localization of β-catenin. In-vitro investigation of the PKD1-β-catenin interaction in colon cancer cells reveal that PKD1 overexpression suppresses cell proliferation and clonogenic potential and enhances cell-cell aggregation. We demonstrate that PKD1 directly interacts with β-catenin and attenuates β-catenin transcriptional activity by decreasing nuclear β-catenin levels. Additionally, we show that inhibition of nuclear β-catenin transcriptional activity is predominantly influenced by nucleus targeted PKD1. This subcellular modulation of β-catenin results in enhanced membrane localization of β-catenin and thereby increases cell-cell adhesion. Studies in a xenograft mouse model indicate that PKD1 overexpression delayed tumor appearance, enhanced necrosis and lowered tumor hypoxia. Overall, our results demonstrate a putative tumor-suppressor function of PKD1 in colon tumorigenesis via modulation of β-catenin functions in cells. PMID:25149539

DPPIV promotes endometrial carcinoma cell proliferation, invasion and tumorigenesis

PubMed Central

Yang, Xiaoqing; Zhang, Xinhua; Wu, Rongrong; Huang, Qicheng; Jiang, Yao; Qin, Jianbing; Yao, Feng; Jin, Guohua; Zhang, Yuquan

2017-01-01

Dipeptidyl peptidase IV (DPPIV), also known as CD26, is a 110-kDa cell surface glycoprotein expressed in various tissues. DPPIV reportedly plays a direct role in the progression of several human malignancies. DPPIV specific inhibitors are employed as antidiabetics and could potentially be repurposed to enhance anti-tumor immunotherapies. In the present study, we investigated the correlation between DPPIV expression and tumor progression in endometrial carcinoma (EC). DPPIV overexpression altered cell morphology and stimulated cell proliferation, invasion and tumorigenesis in vitro and in vivo. These effects were abrogated by DPPIV knockdown or pharmacological inhibition using sitagliptin. DPPIV overexpression increased hypoxia-inducible factor 1a (HIF-1a) and vascular endothelial growth factor A (VEGFA) expression to promote HIF-1a-VEGFA signaling. Our results indicated that DPPIV accelerated endometrial carcinoma progression and that sitagliptin may be an effective anti-EC therapeutic. PMID:28060721

DPPIV promotes endometrial carcinoma cell proliferation, invasion and tumorigenesis.

PubMed

Yang, Xiaoqing; Zhang, Xinhua; Wu, Rongrong; Huang, Qicheng; Jiang, Yao; Qin, Jianbing; Yao, Feng; Jin, Guohua; Zhang, Yuquan

2017-01-31

Dipeptidyl peptidase IV (DPPIV), also known as CD26, is a 110-kDa cell surface glycoprotein expressed in various tissues. DPPIV reportedly plays a direct role in the progression of several human malignancies. DPPIV specific inhibitors are employed as antidiabetics and could potentially be repurposed to enhance anti-tumor immunotherapies. In the present study, we investigated the correlation between DPPIV expression and tumor progression in endometrial carcinoma (EC). DPPIV overexpression altered cell morphology and stimulated cell proliferation, invasion and tumorigenesis in vitro and in vivo. These effects were abrogated by DPPIV knockdown or pharmacological inhibition using sitagliptin. DPPIV overexpression increased hypoxia-inducible factor 1a (HIF-1a) and vascular endothelial growth factor A (VEGFA) expression to promote HIF-1a-VEGFA signaling. Our results indicated that DPPIV accelerated endometrial carcinoma progression and that sitagliptin may be an effective anti-EC therapeutic.

CD147 reinforces [Ca2+]i oscillations and promotes oncogenic progression in hepatocellular carcinoma.

PubMed

Tang, Juan; Guo, Yun-Shan; Yu, Xiao-Ling; Huang, Wan; Zheng, Ming; Zhou, Ying-Hui; Nan, Gang; Wang, Jian-Chao; Yang, Hai-Jiao; Yu, Jing-Min; Jiang, Jian-Li; Chen, Zhi-Nan

2015-10-27

Oscillations in intracellular Ca2+ concentrations ([Ca2+]i) mediate various cellular function. Although it is known that [Ca2+]i oscillations are susceptible to dysregulation in tumors, the tumor-specific regulators of [Ca2+]i oscillations are poorly characterized. We discovered that CD147 promotes hepatocellular carcinoma (HCC) metastasis and proliferation by enhancing the amplitude and frequency of [Ca2+]i oscillations in HCC cells. CD147 activates two distinct signaling pathways to regulate [Ca2+]i oscillations. By activating FAK-Src-IP3R1 signaling pathway, CD147 promotes Ca2+ release from endoplasmic reticulum (ER) and enhances the amplitude of [Ca2+]i oscillations. Furthermore, CD147 accelerates ER Ca2+refilling and enhances the frequency of [Ca2+]i oscillations through activating CaMKP-PAK1-PP2A-PLB-SERCA signaling pathway. Besides, CD147-promoted ER Ca2+ release and refilling are tightly regulated by changing [Ca2+]i. CD147 may activate IP3R1 channel under low [Ca2+]i conditions and CD147 may activate SERCA pump under high [Ca2+]i conditions. CD147 deletion suppresses HCC tumorigenesis and increases the survival rate of liver-specific CD147 knockout mice by regulating [Ca2+]i oscillations in vivo. Together, these results reveal that CD147 functions as a critical regulator of ER-dependent [Ca2+]i oscillations to promote oncogenic progression in HCC.

CD147 reinforces [Ca2+]i oscillations and promotes oncogenic progression in hepatocellular carcinoma

PubMed Central

Zheng, Ming; Zhou, Ying-Hui; Nan, Gang; Wang, Jian-Chao; Yang, Hai-Jiao; Yu, Jing-Min; Jiang, Jian-Li; Chen, Zhi-Nan

2015-01-01

Oscillations in intracellular Ca2+ concentrations ([Ca2+]i) mediate various cellular function. Although it is known that [Ca2+]i oscillations are susceptible to dysregulation in tumors, the tumor-specific regulators of [Ca2+]i oscillations are poorly characterized. We discovered that CD147 promotes hepatocellular carcinoma (HCC) metastasis and proliferation by enhancing the amplitude and frequency of [Ca2+]i oscillations in HCC cells. CD147 activates two distinct signaling pathways to regulate [Ca2+]i oscillations. By activating FAK-Src-IP3R1 signaling pathway, CD147 promotes Ca2+ release from endoplasmic reticulum (ER) and enhances the amplitude of [Ca2+]i oscillations. Furthermore, CD147 accelerates ER Ca2+ refilling and enhances the frequency of [Ca2+]i oscillations through activating CaMKP-PAK1-PP2A-PLB-SERCA signaling pathway. Besides, CD147-promoted ER Ca2+ release and refilling are tightly regulated by changing [Ca2+]i. CD147 may activate IP3R1 channel under low [Ca2+]i conditions and CD147 may activate SERCA pump under high [Ca2+]i conditions. CD147 deletion suppresses HCC tumorigenesis and increases the survival rate of liver-specific CD147 knockout mice by regulating [Ca2+]i oscillations in vivo. Together, these results reveal that CD147 functions as a critical regulator of ER-dependent [Ca2+]i oscillations to promote oncogenic progression in HCC. PMID:26498680

The molecular pathogenesis of schwannomatosis, a paradigm for the co-involvement of multiple tumour suppressor genes in tumorigenesis.

PubMed

Kehrer-Sawatzki, Hildegard; Farschtschi, Said; Mautner, Victor-Felix; Cooper, David N

2017-02-01

Schwannomatosis is characterized by the predisposition to develop multiple schwannomas and, less commonly, meningiomas. Despite the clinical overlap with neurofibromatosis type 2 (NF2), schwannomatosis is not caused by germline NF2 gene mutations. Instead, germline mutations of either the SMARCB1 or LZTR1 tumour suppressor genes have been identified in 86% of familial and 40% of sporadic schwannomatosis patients. In contrast to patients with rhabdoid tumours, which are due to complete loss-of-function SMARCB1 mutations, individuals with schwannomatosis harbour predominantly hypomorphic SMARCB1 mutations which give rise to the synthesis of mutant proteins with residual function that do not cause rhabdoid tumours. Although biallelic mutations of SMARCB1 or LZTR1 have been detected in the tumours of patients with schwannomatosis, the classical two-hit model of tumorigenesis is insufficient to account for schwannoma growth, since NF2 is also frequently inactivated in these tumours. Consequently, tumorigenesis in schwannomatosis must involve the mutation of at least two different tumour suppressor genes, an occurrence frequently mediated by loss of heterozygosity of large parts of chromosome 22q harbouring not only SMARCB1 and LZTR1 but also NF2. Thus, schwannomatosis is paradigmatic for a tumour predisposition syndrome caused by the concomitant mutational inactivation of two or more tumour suppressor genes. This review provides an overview of current models of tumorigenesis and mutational patterns underlying schwannomatosis that will ultimately help to explain the complex clinical presentation of this rare disease.

Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments

NASA Astrophysics Data System (ADS)

Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B.; Wang, Ya

2016-06-01

Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

The tumor suppressor gene WWOX links the canonical and noncanonical NF-κB pathways in HTLV-I Tax-mediated tumorigenesis

PubMed Central

Fu, Jing; Qu, Zhaoxia; Yan, Pengrong; Ishikawa, Chie; Aqeilan, Rami I.; Rabson, Arnold B.

2011-01-01

Both the canonical and noncanonical nuclear factor κB (NF-κB) pathways have been linked to tumorigenesis. However, it remains unknown whether and how the 2 signaling pathways cooperate during tumorigenesis. We report that inhibition of the noncanonical NF-κB pathway significantly delays tumorigenesis mediated by the viral oncoprotein Tax. One function of noncanonical NF-κB activation was to repress expression of the WWOX tumor suppressor gene. Notably, WWOX specifically inhibited Tax-induced activation of the canonical, but not the noncanonical NF-κB pathway. Mechanistic studies indicated that WWOX blocked Tax-induced inhibitors of κB kinaseα (IKKα) recruitment to RelA and subsequent RelA phosphorylation at S536. In contrast, WWOX Y33R, a mutant unable to block the IKKα recruitment and RelA phosphorylation, lost the ability to inhibit Tax-mediated tumorigenesis. These data provide one important mechanism by which Tax coordinates the 2 NF-κB pathways for tumorigenesis. These data also suggest a novel role of WWOX in NF-κB regulation and viral tumorigenesis. PMID:21115974

Constitutive β-catenin Activation Induces Male-Specific Tumorigenesis in the Bladder Urothelium

PubMed Central

Lin, Congxing; Yin, Yan; Stemler, Kristina; Humphrey, Peter; Kibel, Adam S.; Mysorekar, Indira U.; Ma, Liang

2013-01-01

The incidence for bladder urothelial carcinoma (UC), a common malignancy of the urinary tract, is about three times higher in men than in women. Although this gender difference has been primarily attributed to differential exposures, it is likely that underlying biological causes contribute to the gender inequality. In this study, we report a transgenic mouse bladder tumor model upon induction of constitutively activated β-catenin signaling in the adult urothelium. We showed that the histopathology of the tumors observed in our model closely resembled that of the human low grade urothelial carcinoma. Additionally, we provided evidence supporting the KRT5-positive;KRT7-negative basal cells as the putative cells-of-origin for β-catenin-induced luminal tumor. Intriguingly, the tumorigenesis in this model demonstrated a marked difference between opposite sexes; forty percent of males developed macroscopically detectable luminal tumors in twelve weeks, whereas only three percent of females developed tumors. We investigated the mechanisms underlying this sexual dimorphism in pathogenesis and demonstrated that nuclear translocation of the androgen receptor (AR) in the urothelial cells is a critical mechanism contributing to tumor development in male mice. Finally, we performed global gene profiling experiments and defined the molecular signature for the β-catenin-induced tumorigenesis in males. Altogether, we have established a model for investigating sexual dimorphism in UC development, and implicated synergy between β-catenin signaling and androgen/AR signaling in carcinogenesis of the basal urothelial cells. PMID:23928991

Oncogenic Ras induces inflammatory cytokine production by up-regulating the squamous cell carcinoma antigens SerpinB3/B4

PubMed Central

Pan, Ji-An; Sun, Yu; Shi, Chanjuan; Li, Jinyu; Powers, R. Scott; Crawford, Howard C.; Zong, Wei-Xing

2014-01-01

Mounting evidence indicates that oncogenic Ras can modulate cell autonomous inflammatory cytokine production, although the underlying mechanism remains unclear. Here we show that squamous cell carcinoma antigens 1 and 2 (SCCA1/2), members of the Serpin family of serine/cysteine protease inhibitors, are transcriptionally up-regulated by oncogenic Ras via MAPK and the ETS family transcription factor PEA3. Increased SCCA expression leads to inhibition of protein turnover, unfolded protein response, activation of NF-κB, and is essential for Ras-mediated cytokine production and tumor growth. Analysis of human colorectal and pancreatic tumor samples reveals a positive correlation between Ras mutation, enhanced SCCA expression, and IL-6 expression. These results indicate that SCCA is a Ras-responsive factor that has a role in Ras-associated cytokine production and tumorigenesis. PMID:24759783

Tissue-Specific Enrichment of Lymphoma Risk Loci in Regulatory Elements

PubMed Central

Hayes, James E.; Trynka, Gosia; Vijai, Joseph; Offit, Kenneth; Raychaudhuri, Soumya; Klein, Robert J.

2015-01-01

Though numerous polymorphisms have been associated with risk of developing lymphoma, how these variants function to promote tumorigenesis is poorly understood. Here, we report that lymphoma risk SNPs, especially in the non-Hodgkin’s lymphoma subtype chronic lymphocytic leukemia, are significantly enriched for co-localization with epigenetic marks of active gene regulation. These enrichments were seen in a lymphoid-specific manner for numerous ENCODE datasets, including DNase-hypersensitivity as well as multiple segmentation-defined enhancer regions. Furthermore, we identify putatively functional SNPs that are both in regulatory elements in lymphocytes and are associated with gene expression changes in blood. We developed an algorithm, UES, that uses a Monte Carlo simulation approach to calculate the enrichment of previously identified risk SNPs in various functional elements. This multiscale approach integrating multiple datasets helps disentangle the underlying biology of lymphoma, and more broadly, is generally applicable to GWAS results from other diseases as well. PMID:26422229

Hotspots of aberrant enhancer activity punctuate the colorectal cancer epigenome

PubMed Central

Cohen, Andrea J.; Saiakhova, Alina; Corradin, Olivia; Luppino, Jennifer M.; Lovrenert, Katreya; Bartels, Cynthia F.; Morrow, James J.; Mack, Stephen C.; Dhillon, Gursimran; Beard, Lydia; Myeroff, Lois; Kalady, Matthew F.; Willis, Joseph; Bradner, James E.; Keri, Ruth A.; Berger, Nathan A.; Pruett-Miller, Shondra M.; Markowitz, Sanford D.; Scacheri, Peter C.

2017-01-01

In addition to mutations in genes, aberrant enhancer element activity at non-coding regions of the genome is a key driver of tumorigenesis. Here, we perform epigenomic enhancer profiling of a cohort of more than forty genetically diverse human colorectal cancer (CRC) specimens. Using normal colonic crypt epithelium as a comparator, we identify enhancers with recurrently gained or lost activity across CRC specimens. Of the enhancers highly recurrently activated in CRC, most are constituents of super enhancers, are occupied by AP-1 and cohesin complex members, and originate from primed chromatin. Many activate known oncogenes, and CRC growth can be mitigated through pharmacologic inhibition or genome editing of these loci. Nearly half of all GWAS CRC risk loci co-localize to recurrently activated enhancers. These findings indicate that the CRC epigenome is defined by highly recurrent epigenetic alterations at enhancers which activate a common, aberrant transcriptional programme critical for CRC growth and survival. PMID:28169291

S100A6 Protein Negatively Regulates CacyBP/SIP-Mediated Inhibition of Gastric Cancer Cell Proliferation and Tumorigenesis

PubMed Central

Zhang, Kun; Liang, Jie; Chuai, Yucai; Li, Yuan; Wang, Xiaoming

2012-01-01

Calcyclin-binding protein (CacyBP/SIP), identified on the basis of its ability to interact with S100 proteins in a calcium-dependent manner, was previously found to inhibit the proliferation and tumorigenesis of gastric cancer cells in our laboratory. Importantly, the effects of S100 proteins on the biological behavior of CacyBP/SIP in gastric cancer remain unclear. Herein, we report the construction of eukaryotic expression vectors for wild-type CacyBP/SIP and a truncated mutant lacking the S100 protein binding domain (CacyBP/SIPΔS100). The expressions of the wild-type and truncated recombinant proteins were demonstrated by transfection of MKN45 gastric cancer cells. Co-immunoprecipitation assays demonstrated interaction between S100A6 and wild-type CacyBP/SIP in MKN45 cells. Removal of the S100 protein binding domain dramatically reduced the affinity of CacyBP/SIP for S100 proteins as indicated by reduced co-immunoprecipitation of S100A6 by CacyBP/SIPΔS100. The MTT assay, FACS assay, clonogenic assay and tumor xenograft experiment were performed to assess the effect of CacyBP/SIP on cell growth and tumorigenesis in vitro and in vivo. Overexpression of CacyBP/SIP inhibited the proliferation and tumorigenesis of MKN45 gastric cancer cells; the proliferation and tumorigenesis rates were even further reduced by the expression of CacyBP/SIPΔS100. We also showed that S100 proteins negatively regulate CacyBP/SIP-mediated inhibition of gastric cancer cell proliferation, through an effect on β-catenin protein expression and transcriptional activation of Tcf/LEF. Although the underlying mechanism of action requires further investigation, this study provides new insight into the interaction between S100 proteins and CacyBP/SIP, which might enrich our knowledge of S100 proteins and be helpful for our understanding of the development of gastric cancer. PMID:22295074

MicroRNA-1291 targets the FOXA2-AGR2 pathway to suppress pancreatic cancer cell proliferation and tumorigenesis

PubMed Central

Qiu, Jing-Xin; Kim, Edward J.; Yu, Ai-Ming

2016-01-01

Pancreatic cancer is the fourth leading cause of cancer death in the United States. Better understanding of pancreatic cancer biology may help identify new oncotargets towards more effective therapies. This study investigated the mechanistic actions of microRNA-1291 (miR-1291) in the suppression of pancreatic tumorigenesis. Our data showed that miR-1291 was downregulated in a set of clinical pancreatic carcinoma specimens and human pancreatic cancer cell lines. Restoration of miR-1291 expression inhibited pancreatic cancer cell proliferation, which was associated with cell cycle arrest and enhanced apoptosis. Furthermore, miR-1291 sharply suppressed the tumorigenicity of PANC-1 cells in mouse models. A proteomic profiling study revealed 32 proteins altered over 2-fold in miR-1291-expressing PANC-1 cells that could be assembled into multiple critical pathways for cancer. Among them anterior gradient 2 (AGR2) was reduced to the greatest degree. Through computational and experimental studies we further identified that forkhead box protein A2 (FOXA2), a transcription factor governing AGR2 expression, was a direct target of miR-1291. These results connect miR-1291 to the FOXA2-AGR2 regulatory pathway in the suppression of pancreatic cancer cell proliferation and tumorigenesis, providing new insight into the development of miRNA-based therapy to combat pancreatic cancer. PMID:27322206

Mule/Huwe1/Arf-BP1 suppresses Ras-driven tumorigenesis by preventing c-Myc/Miz1-mediated down-regulation of p21 and p15.

PubMed

Inoue, Satoshi; Hao, Zhenyue; Elia, Andrew J; Cescon, David; Zhou, Lily; Silvester, Jennifer; Snow, Bryan; Harris, Isaac S; Sasaki, Masato; Li, Wanda Y; Itsumi, Momoe; Yamamoto, Kazuo; Ueda, Takeshi; Dominguez-Brauer, Carmen; Gorrini, Chiara; Chio, Iok In Christine; Haight, Jillian; You-Ten, Annick; McCracken, Susan; Wakeham, Andrew; Ghazarian, Danny; Penn, Linda J Z; Melino, Gerry; Mak, Tak W

2013-05-15

Tumorigenesis results from dysregulation of oncogenes and tumor suppressors that influence cellular proliferation, differentiation, apoptosis, and/or senescence. Many gene products involved in these processes are substrates of the E3 ubiquitin ligase Mule/Huwe1/Arf-BP1 (Mule), but whether Mule acts as an oncogene or tumor suppressor in vivo remains controversial. We generated K14Cre;Mule(flox/flox(y)) (Mule kKO) mice and subjected them to DMBA/PMA-induced skin carcinogenesis, which depends on oncogenic Ras signaling. Mule deficiency resulted in increased penetrance, number, and severity of skin tumors, which could be reversed by concomitant genetic knockout of c-Myc but not by knockout of p53 or p19Arf. Notably, in the absence of Mule, c-Myc/Miz1 transcriptional complexes accumulated, and levels of p21CDKN1A (p21) and p15INK4B (p15) were down-regulated. In vitro, Mule-deficient primary keratinocytes exhibited increased proliferation that could be reversed by Miz1 knockdown. Transfer of Mule-deficient transformed cells to nude mice resulted in enhanced tumor growth that again could be abrogated by Miz1 knockdown. Our data demonstrate in vivo that Mule suppresses Ras-mediated tumorigenesis by preventing an accumulation of c-Myc/Miz1 complexes that mediates p21 and p15 down-regulation.

Curcumin modifies Apc(min) apoptosis resistance and inhibits 2-amino 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induced tumour formation in Apc(min) mice.

PubMed

Collett, G P; Robson, C N; Mathers, J C; Campbell, F C

2001-05-01

Curcumin, the active ingredient of the rhizome of Curcuma longa, promotes apoptosis and may have chemopreventive properties. This study investigates the effects of curcumin on apoptosis and tumorigenesis in male Apc(min) mice treated with the human dietary carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP). Intestinal epithelial apoptotic index in response to PhIP treatment was approximately twice as great in the wild-type C57BL/6 APC(+/+) strain than in Apc(min) mice (3.7% Apc(+/+) versus 1.9% Apc(min); P < 0.001). PhIP promoted tumour formation in Apc(min) proximal small intestine (4.6 tumours per mouse, PhIP treated versus 2.1 tumours per mouse, control untreated; P < 0.05). Curcumin enhanced PhIP-induced apoptosis (4.0% curcumin + PhIP versus 2.1% PhIP alone; P < 0.01) and inhibited PhIP-induced tumorigenesis in the proximal small intestine of Apc(min) mice (2.2 tumours per mouse, curcumin + PhIP versus 4.6 tumours per mouse PhIP alone; P < 0.05). This study shows that the Apc(min) genotype is associated with resistance to PhIP-induced apoptosis in intestinal epithelium. Curcumin attenuates Apc(min) resistance to PhIP-induced apoptosis and inhibits PhIP-induced tumorigenesis in proximal Apc(min) mouse small intestine.

DcR3 induces epithelial-mesenchymal transition through activation of the TGF-β3/SMAD signaling pathway in CRC

PubMed Central

Hu, Zhi-Yan; Li, Sheng-Nan; Kan, He-Ping; Wang, Xiao-Yan; Li, Zu-Guo

2016-01-01

Decoy receptor 3 (DcR3), a novel member of the tumor necrosis factor receptor (TNFR) family, was recently reported to be associated with tumorigenesis and metastasis. However, the role of DcR3 in human colorectal cancer (CRC) has not been fully elucidated. In this study, we found that DcR3 expression was significantly higher in human colorectal cancer tissues than in paired normal tissues, and that DcR3 expression was strongly correlated with tumor invasion, lymph node metastases and poor prognoses. Moreover, DcR3 overexpression significantly enhanced CRC cell proliferation and migration in vitro and tumorigenesis in vivo. Conversely, DcR3 knockdown significantly repressed CRC cell proliferation and migration in vitro, and DcR3 deficiency also attenuated CRC tumorigenesis and metastasis in vivo. Functionally, DcR3 was essential for TGF-β3/SMAD-mediated epithelial-mesenchymal transition (EMT) of CRC cells. Importantly, cooperation between DcR3 and TGF-β3/SMAD-EMT signaling-related protein expression was correlated with survival and survival time in CRC patients. In conclusion, our results demonstrate that DcR3 may be a prognostic biomarker for CRC and that this receptor facilitates CRC development and metastasis by participating in TGF-β3/SMAD-mediated EMT of CRC cells. PMID:27764793

Elevated STAT3 Signaling-Mediated Upregulation of MMP-2/9 Confers Enhanced Invasion Ability in Multidrug-Resistant Breast Cancer Cells

PubMed Central

Zhang, Fei; Wang, Zhiyong; Fan, Yanling; Xu, Qiao; Ji, Wei; Tian, Ran; Niu, Ruifang

2015-01-01

The development of multidrug resistance greatly impedes effective cancer therapy. Recent advances in cancer research have demonstrated that acquisition of multidrug resistance by cancer cells is usually accompanied by enhanced cell invasiveness. Several lines of evidence indicated that cross activation of other signaling pathways during development of drug resistance may increase invasive potential of multidrug-resistant (MDR) cancer cells. However, the accurate mechanism of this process is largely undefined. In this study, to better understand the associated molecular pathways responsible for cancer progression induced by drug resistance, a MDR human breast cancer cell line SK-BR-3/EPR with P-glycoprotein overexpression was established using stepwise long-term exposure to increasing concentration of epirubicin. The SK-BR-3/EPR cell line exhibited decreased cell proliferative activity, but enhanced cell invasive capacity. We showed that the expression of metastasis-related matrix metalloproteinase (MMP)-2/9 was elevated in SK-BR-3/EPR cells. Moreover, SK-BR-3/EPR cells showed elevated activation of STAT3. Activation of STAT3 signaling is responsible for enhanced invasiveness of SK-BR-3/EPR cells through upregulation of MMP-2/9. STAT3 is a well-known oncogene and is frequently implicated in tumorigenesis and chemotherapeutic resistance. Our findings augment insight into the mechanism underlying the functional association between MDR and cancer invasiveness. PMID:26501276

Synergistic function of Smad4 and PTEN in suppressing forestomach squamous cell carcinoma in the mouse.

PubMed

Teng, Yan; Sun, An-Na; Pan, Xiao-Chen; Yang, Guan; Yang, Lei-Lei; Wang, Ming-Rong; Yang, Xiao

2006-07-15

The genetic bases underlying esophageal tumorigenesis are poorly understood. Our previous studies have shown that coordinated deletion of the Smad4 and PTEN genes results in accelerated hair loss and skin tumor formation in mice. Herein, we exemplify that the concomitant inactivation of Smad4 and PTEN accelerates spontaneous forestomach carcinogenesis at complete penetrance during the first 2 months of age. All of the forestomach tumors were invasive squamous cell carcinomas (SCCs), which recapitulated the natural history and pathologic features of human esophageal SCCs. A small population of the SCC lesions was accompanied by adenocarcinomas at the adjacent submucosa region in the double mutant mice. The rapid progression of forestomach tumor formation in the Smad4 and PTEN double knockout mice corresponded to a dramatic increase in esophageal and forestomach epithelial proliferation. The decreased expression of p27, p21, and p16 together with the overexpression of cyclin D1 contributed cooperatively to the accelerated forestomach tumorigenesis in the double mutant mice. Our results point strongly to the crucial relevance of synergy between Smad4 and PTEN to suppress forestomach tumorigenesis through the cooperative induction of cell cycle inhibitors.

Predictive Genes in Adjacent Normal Tissue Are Preferentially Altered by sCNV during Tumorigenesis in Liver Cancer and May Rate Limiting

PubMed Central

Lamb, John R.; Zhang, Chunsheng; Xie, Tao; Wang, Kai; Zhang, Bin; Hao, Ke; Chudin, Eugene; Fraser, Hunter B.; Millstein, Joshua; Ferguson, Mark; Suver, Christine; Ivanovska, Irena; Scott, Martin; Philippar, Ulrike; Bansal, Dimple; Zhang, Zhan; Burchard, Julja; Smith, Ryan; Greenawalt, Danielle; Cleary, Michele; Derry, Jonathan; Loboda, Andrey; Watters, James; Poon, Ronnie T. P.; Fan, Sheung T.; Yeung, Chun; Lee, Nikki P. Y.; Guinney, Justin; Molony, Cliona; Emilsson, Valur; Buser-Doepner, Carolyn; Zhu, Jun; Friend, Stephen; Mao, Mao; Shaw, Peter M.; Dai, Hongyue; Luk, John M.; Schadt, Eric E.

2011-01-01

Background In hepatocellular carcinoma (HCC) genes predictive of survival have been found in both adjacent normal (AN) and tumor (TU) tissues. The relationships between these two sets of predictive genes and the general process of tumorigenesis and disease progression remains unclear. Methodology/Principal Findings Here we have investigated HCC tumorigenesis by comparing gene expression, DNA copy number variation and survival using ∼250 AN and TU samples representing, respectively, the pre-cancer state, and the result of tumorigenesis. Genes that participate in tumorigenesis were defined using a gene-gene correlation meta-analysis procedure that compared AN versus TU tissues. Genes predictive of survival in AN (AN-survival genes) were found to be enriched in the differential gene-gene correlation gene set indicating that they directly participate in the process of tumorigenesis. Additionally the AN-survival genes were mostly not predictive after tumorigenesis in TU tissue and this transition was associated with and could largely be explained by the effect of somatic DNA copy number variation (sCNV) in cis and in trans. The data was consistent with the variance of AN-survival genes being rate-limiting steps in tumorigenesis and this was confirmed using a treatment that promotes HCC tumorigenesis that selectively altered AN-survival genes and genes differentially correlated between AN and TU. Conclusions/Significance This suggests that the process of tumor evolution involves rate-limiting steps related to the background from which the tumor evolved where these were frequently predictive of clinical outcome. Additionally treatments that alter the likelihood of tumorigenesis occurring may act by altering AN-survival genes, suggesting that the process can be manipulated. Further sCNV explains a substantial fraction of tumor specific expression and may therefore be a causal driver of tumor evolution in HCC and perhaps many solid tumor types. PMID:21750698

Checkpoint suppressor 1 suppresses transcriptional activity of ERα and breast cancer cell proliferation via deacetylase SIRT1.

PubMed

Xu, Zhaowei; Yang, Yangyang; Li, Bowen; Li, Yanan; Xia, Kangkai; Yang, Yuxi; Li, Xiahui; Wang, Miao; Li, Shujing; Wu, Huijian

2018-05-11

Breast cancer is a highly heterogeneous carcinoma in women worldwide, but the underlying mechanisms that account for breast cancer initiation and development have not been fully established. Mounting evidence indicates that Checkpoint suppressor 1 (CHES1) is tightly associated with tumorigenesis and prognosis in many types of cancer. However, the definitive function of CHES1 in breast cancer remains to be explored. Here we showed that CHES1 had a physical interaction with estrogen receptor-α (ERα) and repressed the transactivation of ERα in breast cancer cells. Mechanistically, the interaction between CHES1 and ERα enhanced the recruitment of nicotinamide adenine dinucleotide (NAD+) deacetylase Sirtuin 1 (SIRT1), and it further induced SIRT1-mediated ERα deacetylation and repression on the promoter-binding enrichment of ERα. In addition, we also found that the expression of CHES1 was repressed by estrogen-ERα signaling and the expression level of CHES1 was significantly downregulated in ERα-positive breast cancer. The detailed mechanism was that ERα may directly bind to CHES1 potential promoter via recognizing the conserved estrogen response element (ERE) motif in response to estrogen stimulation. Functionally, CHES1 inhibited ERα-mediated proliferation and tumorigenesis of breast cancer cells in vivo and in vitro. Totally, these results identified a negative cross-regulatory loop between ERα and CHES1 that was required for growth of breast cancer cells, it might uncover novel insight into molecular mechanism of CHES1 involved in breast cancer and provide new avenues for molecular-targeted therapy in hormone-regulated breast cancer.

Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments.

PubMed

Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B; Wang, Ya

2016-06-01

Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Agrobacterium tumefaciens mutants affected in attachment to plant cells.

PubMed Central

Douglas, C J; Halperin, W; Nester, E W

1982-01-01

An analysis of Agrobacterium tumefaciens mutants with Tn5 insertions in chromosomal DNA showed that the chromosome of A. tumefaciens codes for a specific ability of this bacterium to attach to plant cells. This ability is associated with tumorigenesis by A. tumefaciens, the ability of avirulent A. tumefaciens to inhibit tumorigenesis, and the ability to adsorb certain phages. A second class of chromosomal mutations affects tumorigenesis without altering the ability to attach to plant cells. The attachment of A. tumefaciens to plant cells was assayed by mixing radiolabeled bacteria with suspensions of tobacco tissue culture cells or freshly isolated Zinnia leaf mesophyll cells. Under the conditions of this assay, an avirulent Ti plasmid-cured strain attached to the same extent as the same strain containing pTiB6806. Six of eight avirulent mutants with Tn5 insertions in chromosomal DNA showed defective attachment, whereas two retained wild-type attachment ability. In contrast to the strains showing wild-type attachment, the attachment-defective mutants failed to inhibit tumorigenesis when inoculated onto Jerusalem artichoke slices before inoculation of a virulent strain and also showed a loss of sensitivity to two Agrobacterium phages. The loss of phage sensitivity appeared to be due to a loss of ability to adsorb the phages. Staining with Calcofluor indicated that the mutants retained the ability to synthesize cellulose fibrils, which have been implicated in the attachment process. Southern filter hybridizations demonstrated that each mutant contained a single Tn5 insertion, and genetic linkage between the Tn5 insertion in one mutant and the attachment phenotype has also been demonstrated. Images PMID:6292165

Glutathione peroxidase-2 and selenium decreased inflammation and tumors in a mouse model of inflammation-associated carcinogenesis whereas sulforaphane effects differed with selenium supply

PubMed Central

Krehl, Susanne; Loewinger, Maria; Florian, Simone; Kipp, Anna P.; Banning, Antje; Wessjohann, Ludger A.; Brauer, Martin N.; Iori, Renato; Esworthy, Robert S.; Chu, Fong-Fong; Brigelius-Flohé, Regina

2012-01-01

Chronic inflammation and selenium deficiency are considered as risk factors for colon cancer. The protective effect of selenium might be mediated by specific selenoproteins, such as glutathione peroxidases (GPx). GPx-1 and -2 double knockout, but not single knockout mice, spontaneously develop ileocolitis and intestinal cancer. Since GPx2 is induced by the chemopreventive sulforaphane (SFN) via the nuclear factor E2-related factor 2 (Nrf2)/Keap1 system, the susceptibility of GPx2-KO and wild-type (WT) mice to azoxymethane and dextran sulfate sodium (AOM/DSS)-induced colon carcinogenesis was tested under different selenium states and SFN applications. WT and GPx2-KO mice were grown on a selenium-poor, -adequate or -supranutritional diet. SFN application started either 1 week before (SFN4) or along with (SFN3) a single AOM application followed by DSS treatment for 1 week. Mice were assessed 3 weeks after AOM for colitis and Nrf2 target gene expression and after 12 weeks for tumorigenesis. NAD(P)H:quinone oxidoreductases, thioredoxin reductases and glutathione-S-transferases were upregulated in the ileum and/or colon by SFN, as was GPx2 in WT mice. Inflammation scores were more severe in GPx2-KO mice and highest in selenium-poor groups. Inflammation was enhanced by SFN4 in both genotypes under selenium restriction but decreased in selenium adequacy. Total tumor numbers were higher in GPx2-KO mice but diminished by increasing selenium in both genotypes. SFN3 reduced inflammation and tumor multiplicity in both Se-adequate genotypes. Tumor size was smaller in Se-poor GPx2-KO mice. It is concluded that GPx2, although supporting tumor growth, inhibits inflammation-mediated tumorigenesis, but the protective effect of selenium does not strictly depend on GPx2 expression. Similarly, SFN requires selenium but not GPx2 for being protective. PMID:22180572

Glutathione peroxidase-2 and selenium decreased inflammation and tumors in a mouse model of inflammation-associated carcinogenesis whereas sulforaphane effects differed with selenium supply.

PubMed

Krehl, Susanne; Loewinger, Maria; Florian, Simone; Kipp, Anna P; Banning, Antje; Wessjohann, Ludger A; Brauer, Martin N; Iori, Renato; Esworthy, Robert S; Chu, Fong-Fong; Brigelius-Flohé, Regina

2012-03-01

Chronic inflammation and selenium deficiency are considered as risk factors for colon cancer. The protective effect of selenium might be mediated by specific selenoproteins, such as glutathione peroxidases (GPx). GPx-1 and -2 double knockout, but not single knockout mice, spontaneously develop ileocolitis and intestinal cancer. Since GPx2 is induced by the chemopreventive sulforaphane (SFN) via the nuclear factor E2-related factor 2 (Nrf2)/Keap1 system, the susceptibility of GPx2-KO and wild-type (WT) mice to azoxymethane and dextran sulfate sodium (AOM/DSS)-induced colon carcinogenesis was tested under different selenium states and SFN applications. WT and GPx2-KO mice were grown on a selenium-poor, -adequate or -supranutritional diet. SFN application started either 1 week before (SFN4) or along with (SFN3) a single AOM application followed by DSS treatment for 1 week. Mice were assessed 3 weeks after AOM for colitis and Nrf2 target gene expression and after 12 weeks for tumorigenesis. NAD(P)H:quinone oxidoreductases, thioredoxin reductases and glutathione-S-transferases were upregulated in the ileum and/or colon by SFN, as was GPx2 in WT mice. Inflammation scores were more severe in GPx2-KO mice and highest in selenium-poor groups. Inflammation was enhanced by SFN4 in both genotypes under selenium restriction but decreased in selenium adequacy. Total tumor numbers were higher in GPx2-KO mice but diminished by increasing selenium in both genotypes. SFN3 reduced inflammation and tumor multiplicity in both Se-adequate genotypes. Tumor size was smaller in Se-poor GPx2-KO mice. It is concluded that GPx2, although supporting tumor growth, inhibits inflammation-mediated tumorigenesis, but the protective effect of selenium does not strictly depend on GPx2 expression. Similarly, SFN requires selenium but not GPx2 for being protective.

Role of Mesenchymal Stem Cells In Tumorigenesis

DTIC Science & Technology

2009-08-01

1951;5(4):417-432. 6. Cornil I, Theodorescu D, Man S, Herlyn M, Jambrosic J, Kerbel RS. Fibroblast cell interactions with human melanoma cells affect...metalloproteinase 9 in mucosally invasive gastric cancer, Gastric Cancer 1 (1998) 142–145.ells produce CCL5 under the influence of cancer cells and

Disruption of microRNA expression in human airway cells by diesel exhaust particles is linked to tumorigenesis-associated pathways

EPA Science Inventory

Background: Particulate matter is associated with adverse airway health effects; however, the underlying mechanism in disease initiation is still largely unknown. Recently, microRNAs (small noncoding RNAs) have been suggested as important in maintaining the lung in a disease free...

Deletion of Ptprd and Cdkn2a cooperate to accelerate tumorigenesis

PubMed Central

Ortiz, Berenice; White, Julie R.; Wu, Wei H.; Chan, Timothy A.

2014-01-01

PTPRD encodes the protein tyrosine phosphatase receptor type D and is frequently inactivated across many human cancers. Despite its frequent inactivation, it is unknown whether loss of PTPRD promotes tumorigenesis in vivo. PTPRD is located on chromosome 9p, as is CDKN2A, and the two loci are frequently deleted together. Here, we show that co-deletion of Ptprd and Cdkn2a cooperate to accelerate tumorigenesis. Interestingly, heterozygous loss of Ptprd was sufficient to promote tumorigenesis in our model, suggesting that Ptprd may be a haploinsufficient tumor suppressor. The loss of Ptprd resulted in changes to the tumor spectrum in mice and increased the frequency of lymphomas. In total, we reveal that Ptprd is a tumor suppressor that can promote tumorigenesis in concert with Cdkn2a loss. PMID:25138050

Seminal Plasma Enhances Cervical Adenocarcinoma Cell Proliferation and Tumour Growth In Vivo

PubMed Central

Sutherland, Jason R.; Sales, Kurt J.; Jabbour, Henry N.; Katz, Arieh A.

2012-01-01

Cervical cancer is one of the leading causes of cancer-related death in women in sub-Saharan Africa. Extensive evidence has shown that cervical cancer and its precursor lesions are caused by Human papillomavirus (HPV) infection. Although the vast majority of HPV infections are naturally resolved, failure to eradicate infected cells has been shown to promote viral persistence and tumorigenesis. Furthermore, following neoplastic transformation, exposure of cervical epithelial cells to inflammatory mediators either directly or via the systemic circulation may enhance progression of the disease. It is well recognised that seminal plasma contains an abundance of inflammatory mediators, which are identified as regulators of tumour growth. Here we investigated the role of seminal plasma in regulating neoplastic cervical epithelial cell growth and tumorigenesis. Using HeLa cervical adenocarcinoma cells, we found that seminal plasma (SP) induced the expression of the inflammatory enzymes, prostaglandin endoperoxide synthase (PTGS1 and PTGS2), cytokines interleukin (IL) -6, and -11 and vascular endothelial growth factor-A(VEGF-A). To investigate the role of SP on tumour cell growth in vivo, we xenografted HeLa cells subcutaneously into the dorsal flank of nude mice. Intra-peritoneal administration of SP rapidly and significantly enhanced the tumour growth rate and size of HeLa cell xenografts in nude mice. As observed in vitro, we found that SP induced expression of inflammatory PTGS enzymes, cytokines and VEGF-A in vivo. Furthermore we found that SP enhances blood vessel size in HeLa cell xenografts. Finally we show that SP-induced cytokine production, VEGF-A expression and cell proliferation are mediated via the induction of the inflammatory PTGS pathway. PMID:22442729

Seminal plasma enhances cervical adenocarcinoma cell proliferation and tumour growth in vivo.

PubMed

Sutherland, Jason R; Sales, Kurt J; Jabbour, Henry N; Katz, Arieh A

2012-01-01

Cervical cancer is one of the leading causes of cancer-related death in women in sub-Saharan Africa. Extensive evidence has shown that cervical cancer and its precursor lesions are caused by Human papillomavirus (HPV) infection. Although the vast majority of HPV infections are naturally resolved, failure to eradicate infected cells has been shown to promote viral persistence and tumorigenesis. Furthermore, following neoplastic transformation, exposure of cervical epithelial cells to inflammatory mediators either directly or via the systemic circulation may enhance progression of the disease. It is well recognised that seminal plasma contains an abundance of inflammatory mediators, which are identified as regulators of tumour growth. Here we investigated the role of seminal plasma in regulating neoplastic cervical epithelial cell growth and tumorigenesis. Using HeLa cervical adenocarcinoma cells, we found that seminal plasma (SP) induced the expression of the inflammatory enzymes, prostaglandin endoperoxide synthase (PTGS1 and PTGS2), cytokines interleukin (IL) -6, and -11 and vascular endothelial growth factor-A (VEGF-A). To investigate the role of SP on tumour cell growth in vivo, we xenografted HeLa cells subcutaneously into the dorsal flank of nude mice. Intra-peritoneal administration of SP rapidly and significantly enhanced the tumour growth rate and size of HeLa cell xenografts in nude mice. As observed in vitro, we found that SP induced expression of inflammatory PTGS enzymes, cytokines and VEGF-A in vivo. Furthermore we found that SP enhances blood vessel size in HeLa cell xenografts. Finally we show that SP-induced cytokine production, VEGF-A expression and cell proliferation are mediated via the induction of the inflammatory PTGS pathway.

A De Novo Mouse Model of C11orf95-RELA Fusion-Driven Ependymoma Identifies Driver Functions in Addition to NF-κB.

PubMed

Ozawa, Tatsuya; Arora, Sonali; Szulzewsky, Frank; Juric-Sekhar, Gordana; Miyajima, Yoshiteru; Bolouri, Hamid; Yasui, Yoshie; Barber, Jason; Kupp, Robert; Dalton, James; Jones, Terreia S; Nakada, Mitsutoshi; Kumabe, Toshihiro; Ellison, David W; Gilbertson, Richard J; Holland, Eric C

2018-06-26

The majority of supratentorial ependymomas (ST-ependymomas) have few mutations but frequently display chromothripsis of chromosome 11q that generates a fusion between C11orf95 and RELA (RELA FUS ). Neural stem cells transduced with RELA FUS ex vivo form ependymomas when implanted in the brain. These tumors display enhanced NF-κB signaling, suggesting that this aberrant signal is the principal mechanism of oncogenesis. However, it is not known whether RELA FUS is sufficient to drive de novo ependymoma tumorigenesis in the brain and, if so, whether these tumors also arise from neural stem cells. We show that RELA FUS drives ST-ependymoma formation from periventricular neural stem cells in mice and that RELA FUS -induced tumorigenesis is likely dependent on a series of cell signaling pathways in addition to NF-κB. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Circadian Rhythm Disruption Promotes Lung Tumorigenesis.

PubMed

Papagiannakopoulos, Thales; Bauer, Matthew R; Davidson, Shawn M; Heimann, Megan; Subbaraj, Lakshmipriya; Bhutkar, Arjun; Bartlebaugh, Jordan; Vander Heiden, Matthew G; Jacks, Tyler

2016-08-09

Circadian rhythms are 24-hr oscillations that control a variety of biological processes in living systems, including two hallmarks of cancer, cell division and metabolism. Circadian rhythm disruption by shift work is associated with greater risk for cancer development and poor prognosis, suggesting a putative tumor-suppressive role for circadian rhythm homeostasis. Using a genetically engineered mouse model of lung adenocarcinoma, we have characterized the effects of circadian rhythm disruption on lung tumorigenesis. We demonstrate that both physiologic perturbation (jet lag) and genetic mutation of the central circadian clock components decreased survival and promoted lung tumor growth and progression. The core circadian genes Per2 and Bmal1 were shown to have cell-autonomous tumor-suppressive roles in transformation and lung tumor progression. Loss of the central clock components led to increased c-Myc expression, enhanced proliferation, and metabolic dysregulation. Our findings demonstrate that both systemic and somatic disruption of circadian rhythms contribute to cancer progression. Copyright © 2016 Elsevier Inc. All rights reserved.

Itch/β-arrestin2-dependent non-proteolytic ubiquitylation of SuFu controls Hedgehog signalling and medulloblastoma tumorigenesis.

PubMed

Infante, Paola; Faedda, Roberta; Bernardi, Flavia; Bufalieri, Francesca; Lospinoso Severini, Ludovica; Alfonsi, Romina; Mazzà, Daniela; Siler, Mariangela; Coni, Sonia; Po, Agnese; Petroni, Marialaura; Ferretti, Elisabetta; Mori, Mattia; De Smaele, Enrico; Canettieri, Gianluca; Capalbo, Carlo; Maroder, Marella; Screpanti, Isabella; Kool, Marcel; Pfister, Stefan M; Guardavaccaro, Daniele; Gulino, Alberto; Di Marcotullio, Lucia

2018-03-07

Suppressor of Fused (SuFu), a tumour suppressor mutated in medulloblastoma, is a central player of Hh signalling, a pathway crucial for development and deregulated in cancer. Although the control of Gli transcription factors by SuFu is critical in Hh signalling, our understanding of the mechanism regulating this key event remains limited. Here, we show that the Itch/β-arrestin2 complex binds SuFu and induces its Lys63-linked polyubiquitylation without affecting its stability. This process increases the association of SuFu with Gli3, promoting the conversion of Gli3 into a repressor, which keeps Hh signalling off. Activation of Hh signalling antagonises the Itch-dependent polyubiquitylation of SuFu. Notably, different SuFu mutations occurring in medulloblastoma patients are insensitive to Itch activity, thus leading to deregulated Hh signalling and enhancing medulloblastoma cell growth. Our findings uncover mechanisms controlling the tumour suppressive functions of SuFu and reveal that their alterations are implicated in medulloblastoma tumorigenesis.

The long non-coding RNA LSINCT5 promotes malignancy in non-small cell lung cancer by stabilizing HMGA2.

PubMed

Tian, Yuheng; Zhang, Lina; Chen, Shuwen; Ma, Yuan; Liu, Yanyan

2018-06-08

Long non-coding RNAs (lncRNAs) can actively participate in tumorigenesis in various cancers. However, the involvement of lncRNA long stress induced non-coding transcripts 5 (LSINCT5) in non-small cell lung cancer (NSCLC) remains largely unknown. Here we showed a novel lncRNA signature in NSCLC through lncRNA profiling. Increased LSINCT5 expression positively correlates with malignant clinicopathological features and poor survival. LSINCT5 can promote migration and viability of various NSCLC cells in vitro and also enhance lung cancer progression in vivo. RNA immunoprecipitation followed by mass spectrometry has identified that LSINCT5 interacts with HMGA2. This physical interaction can increase the stability of HMGA2 by inhibiting proteasome-mediated degradation. Therefore, LSINCT5 may possibly contribute to NSCLC tumorigenesis by stabilizing the oncogenic factor of HMGA2. This novel LSINCT5/HMGA2 axis can modulate lung cancer progression and might be a promising target for pharmacological intervention.

The Dynamic Epigenetic Landscape of the Retina During Development, Reprogramming, and Tumorigenesis

PubMed Central

Aldiri, Issam; Xu, Beisi; Wang, Lu; Chen, Xiang; Hiler, Daniel; Griffiths, Lyra; Valentine, Marc; Shirinifard, Abbas; Thiagarajan, Suresh; Sablauer, Andras; Barabas, Marie-Elizabeth; Zhang, Jiakun; Johnson, Dianna; Frase, Sharon; Zhou, Xin; Easton, John; Zhang, Jinghui; Mardis, Elaine R.; Wilson, Richard K.; Downing, James R.; Dyer, Michael A.

2017-01-01

SUMMARY In the developing retina, multipotent neural progenitors undergo unidirectional differentiation in a precise spatiotemporal order. Here we profile the epigenetic and transcriptional changes that occur during retinogenesis in mice and humans. Although some progenitor genes and cell cycle genes were epigenetically silenced during retinogenesis, the most dramatic change was derepression of cell type–specific differentiation programs. We identified developmental stage–specific super-enhancers and showed that most epigenetic changes are conserved in humans and mice. To determine how the epigenome changes during tumorigenesis and reprogramming, we performed integrated epigenetic analysis of murine and human retinoblastomas and induced pluripotent stem cells (iPSCs) derived from murine rod photoreceptors. The retinoblastoma epigenome mapped to the developmental stage when retinal progenitors switch from neurogenic to a terminal patterns of cell division. The epigenome of retinoblastomas was more similar to that of normal retina than was that of retina-derived iPSCs, and we identified retina-specific epigenetic memory. PMID:28472656

O-GlcNAcylation of RACK1 promotes hepatocellular carcinogenesis.

PubMed

Duan, Fangfang; Wu, Hao; Jia, Dongwei; Wu, Weicheng; Ren, Shifang; Wang, Lan; Song, Shushu; Guo, Xinying; Liu, Fenglin; Ruan, Yuanyuan; Gu, Jianxin

2018-06-01

Aberrant oncogenic mRNA translation and protein O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) are general features during tumorigenesis. Nevertheless, whether and how these two pathways are interlinked remain unknown. Our previous study indicated that ribosomal receptor for activated C-kinase 1 (RACK1) promoted chemoresistance and growth in hepatocellular carcinoma (HCC). The aim of this study is to examine the role of RACK1 O-GlcNAcylation in oncogene translation and HCC carcinogenesis. The site(s) of RACK1 for O-GlcNAcylation was mapped by mass spectrometry analysis. HCC cell lines were employed to examine the effects of RACK1 O-GlcNAcylation on the translation of oncogenic factors and behaviors of tumor cells in vitro. Transgenic knock-in mice were used to detect the role of RACK1 O-GlcNAcylation in modulating HCC tumorigenesis in vivo. The correlation of RACK1 O-GlcNAcylation with tumor progression and relapse were analyzed in clinical HCC samples. We found that ribosomal RACK1 was highly modified by O-GlcNAc at Ser122. O-GlcNAcylation of RACK1 enhanced its protein stability, ribosome binding and interaction with PKCβII (PRKCB), leading to increased eukaryotic translation initiation factor 4E phosphorylation and translation of potent oncogenes in HCC cells. Genetic ablation of RACK1 O-GlcNAcylation at Ser122 dramatically suppressed tumorigenesis, angiogenesis, and metastasis in vitro and in diethylnitrosamine (DEN)-induced HCC mouse model. Increased RACK1 O-GlcNAcylation was also observed in HCC patient samples and correlated with tumor development and recurrence after chemotherapy. These findings demonstrate that RACK1 acts as key mediator linking O-GlcNAc metabolism to cap-dependent translation during HCC tumorigenesis. Targeting RACK1 O-GlcNAcylation provides promising options for HCC treatment. O-GlcNAcylation of ribosomal receptor for activated C-kinase 1 at the amino acid serine122 promotes its stability, ribosome localization and interaction with the protein kinase, PKCβII, thus driving the translation of oncogenes and tumorigenesis of hepatocellular carcinoma. Increased O-GlcNAcylation of ribosomal receptor for activated C-kinase 1 is positively correlated with tumor growth, metastasis and recurrence in patients with hepatocellular carcinoma. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Long non-coding RNA PlncRNA-1 promotes cell proliferation and hepatic metastasis in colorectal cancer.

PubMed

Jia, Gui-Qing; Zhang, Ming-Ming; Wang, Kang; Zhao, Gao-Ping; Pang, Ming-Hui; Chen, Zhe-Yu

2018-05-08

Emerging evidence has identified that long non-coding RNAs (lncRNAs) may play an important role in the pathogenesis of many cancer types, including colorectal cancer (CRC). However, the role of PlncRNA-1 in CRC remains unclear. The aim of our present study was to investigate the potential functions of PlncRNA-1 in CRC and to identify the underlying mechanisms of action. We demonstrated that up-regulated PlncRNA-1 in CRC tissues and cells promoted cell proliferation by accelerating cell cycle process and inhibiting cell apoptosis in vitro, enhanced tumor growth and matastasis in vivo and was associated with cell migration and invasion, EMT process of CRC cells. In addition, PlncRNA-1 was a target of miR-204 and enhanced the expression of an endogenous miR-204 target, MMP9 in CRC cells. Furthermore, we found that PlncRNA-1 activates Wnt/β-catenin pathway through the miR-204 in CRC cells. These results suggest that the PlncRNA-1/miR-204/ Wnt/β-catenin regulatory network may shed light on tumorigenesis in CRC. © 2018 Wiley Periodicals, Inc.

Acetylation of androgen receptor by ARD1 promotes dissociation from HSP90 complex and prostate tumorigenesis

PubMed Central

Zhang, Guanyi; Qian, Chiping; Zhang, Haitao; Zabaleta, Jovanny; Liu, Wanguo

2016-01-01

Prostate cancer is an androgen receptor (AR)-driven disease and post-translational modification of AR is critical for AR activation. We previously reported that Arrest-defective protein 1 (ARD1) is an oncoprotein in prostate cancer. It acetylates and activates AR to promote prostate tumorigenesis. However, the ARD1-targeted residue within AR and the mechanisms of the acetylation event in prostate tumorigenesis remained unknown. In this study, we show that ARD1 acetylates AR at lysine 618 (K618) in vitro and in vivo. An AR construct with the charged lysine substitution by arginine (AR-618R) reduces RNA Pol II binding, AR transcriptional activity, prostate cancer cell growth, and xenograft tumor formation due to attenuation of AR nuclear translocation, whereas, construct mimicking neutral polar substitution acetylation at K618 by glutamine (AR-618Q) enhanced these effects beyond that of the wild-type AR. Mechanistically, ARD1 forms a ternary complex with AR and HSP90 in vitro and in vivo. Expression of ARD1 increases levels of AR acetylation and AR-HSP90 dissociation in a dose dependent manner. Moreover, the AR acetylation defective K618R mutant is unable to dissociate from HSP90 while the HSP90-dissociated AR is acetylated following ligand exposure. This work identifies a new mechanism for ligand-induced AR-HSP90 dissociation and AR activation. Targeting ARD1-mediated AR acetylation may be a potent intervention for AR-dependent prostate cancer therapy. PMID:27659526

Induction of apoptosis by [6]-gingerol associated with the modulation of p53 and involvement of mitochondrial signaling pathway in B[a]P-induced mouse skin tumorigenesis.

PubMed

Nigam, Nidhi; George, Jasmine; Srivastava, Smita; Roy, Preeti; Bhui, Kulpreet; Singh, Madhulika; Shukla, Yogeshwer

2010-03-01

To unravel the molecular mechanisms underlying the chemopreventive potential of [6]-gingerol, a pungent ingredient of ginger rhizome (Zingiber officinale Roscoe, Zingiberaceae), against benzo[a]pyrene (B[a]P)-induced mouse skin tumorigenesis. Topical treatment of [6]-gingerol (2.5 muM/animal) was given to the animals 30 min prior and post to B[a]P (5 mug/animal) for 32 weeks. At the end of the study period, the skin tumors/tissues were dissected out and examined histopathologically. Flow cytometry was employed for cell cycle analysis. Further immunohistochemical localization of p53 and regulation of related apoptogenic proteins were determined by Western blotting. Chemopreventive properties of [6]-gingerol were reflected by delay in onset of tumorigenesis, reduced cumulative number of tumors, and reduction in tumor volume. Cell cycle analysis revealed that the appearance of sub-G1 peak was significantly elevated in [6]-gingerol treated animals with post treatment showing higher efficacy in preventing tumorigenesis induced by B[a]P. Moreover, elevated apoptotic propensity was observed in tumor tissues than the corresponding non-tumor tissues. Western blot analysis also showed the same pattern of chemoprevention with [6]-gingerol treatment increasing the B[a]P suppressed p53 levels, also evident by immunohistochemistry, and Bax while decreasing the expression of Bcl-2 and Survivin. Further, [6]-gingerol treatment resulted in release of Cytochrome c, Caspases activation, increase in apoptotic protease-activating factor-1 (Apaf-1) as mechanism of apoptosis induction. On the basis of the results we conclude that [6]-gingerol possesses apoptotic potential in mouse skin tumors as mechanism of chemoprevention hence deserves further investigation.

Tumors overexpressing RNF168 show altered DNA repair and responses to genotoxic treatments, genomic instability and resistance to proteotoxic stress.

PubMed

Chroma, K; Mistrik, M; Moudry, P; Gursky, J; Liptay, M; Strauss, R; Skrott, Z; Vrtel, R; Bartkova, J; Kramara, J; Bartek, J

2017-04-27

Chromatin DNA damage response (DDR) is orchestrated by the E3 ubiquitin ligase ring finger protein 168 (RNF168), resulting in ubiquitin-dependent recruitment of DDR factors and tumor suppressors breast cancer 1 (BRCA1) and p53 binding protein 1 (53BP1). This ubiquitin signaling regulates pathway choice for repair of DNA double-strand breaks (DSB), toxic lesions whose frequency increases during tumorigenesis. Recruitment of 53BP1 curbs DNA end resection, thereby limiting homologous recombination (HR) and directing DSB repair toward error-prone non-homologous end joining (NHEJ). Under cancer-associated ubiquitin starvation conditions reflecting endogenous or treatment-evoked proteotoxic stress, the ubiquitin-dependent accrual of 53BP1 and BRCA1 at the DNA damage sites is attenuated or lost. Challenging this current paradigm, here we identified diverse human cancer cell lines that display 53BP1 recruitment to DSB sites even under proteasome inhibitor-induced proteotoxic stress, that is, under substantial depletion of free ubiquitin. We show that central to this unexpected phenotype is overabundance of RNF168 that enables more efficient exploitation of the residual-free ubiquitin. Cells with elevated RNF168 are more resistant to combined treatment by ionizing radiation and proteasome inhibition, suggesting that such aberrant RNF168-mediated signaling might reflect adaptation to chronic proteotoxic and genotoxic stresses experienced by tumor cells. Moreover, the overabundant RNF168 and the ensuing unorthodox recruitment patterns of 53BP1, RIF1 and REV7 (monitored on laser micro-irradiation-induced DNA damage) shift the DSB repair balance from HR toward NHEJ, a scenario accompanied by enhanced chromosomal instability/micronuclei formation and sensitivity under replication stress-inducing treatments with camptothecin or poly(ADP-ribose) polymerase (PARP) inhibitor. Overall, our data suggest that the deregulated RNF168/53BP1 pathway could promote tumorigenesis by selecting for a more robust, better stress-adapted cancer cell phenotype, through altered DNA repair, fueling genomic instability and tumor heterogeneity. Apart from providing insights into cancer (patho)biology, the elevated RNF168, documented here also by immunohistochemistry on human clinical tumor specimens, may impact responses to standard-of-care and some emerging targeted cancer therapies.

Inflammation-induced S100A8 activates Id3 and promotes colorectal tumorigenesis.

PubMed

Zhang, Xuemei; Ai, Feiyan; Li, Xiayu; She, Xiaoling; Li, Nan; Tang, Anliu; Qin, Zailong; Ye, Qiurong; Tian, Li; Li, Guiyuan; Shen, Shourong; Ma, Jian

2015-12-15

The aberrant expression of S100A8 and S100A9 is linked to nonresolving inflammation and ultimately to carcinogenesis, whereas the underlying mechanism that allows inflammation to progress to specific cancer types remains unknown. Here, we report that S100A8 was induced by inflammation and then promoted colorectal tumorigenesis downstream by activating Id3 (inhibitor of differentiation 3). Using gene expression profiling and immunohistochemistry, we found that both S100A8 and S100A9 were upregulated in the chemically-induced colitis-associated cancer mouse model and in human colorectal cancer specimens. Furthermore, we showed that S100A8 and S100A9 acted as chemoattractant proteins by recruiting macrophages, promoting the proliferation and invasion of colon cancer cell, as well as spurring the cycle that culminates in the acceleration of cancer metastasis in a nude mouse model. S100A8 regulated colon cancer cell cycle and proliferation by inducing Id3 expression while inhibiting p21. Id3 expression was regulated by Smad5, which was directly phosphorylated by Akt1. Our study revealed a novel mechanism in which inflammation-induced S100A8 promoted colorectal tumorigenesis by acting upstream to activate the Akt1-Smad5-Id3 axis. © 2015 UICC.

Cancer in Inflammatory Bowel Disease: lessons from animal models

PubMed Central

Sussman, Daniel; Santaolalla, Rebeca; Strobel, Sebastian; Dheer, Rishu; Abreu, Maria T.

2012-01-01

Purpose of the review Human colitis-associated cancers (CAC) represent a heterogeneous group of conditions in which multiple oncogenic pathways are involved. In this manuscript we reviewed the latest studies using genetic, chemically induced, bacterial and innate immunity induced experimental models of colitis-associated cancer. Recent findings Using the azoxymethane-dextran sodium sulfate model wound healing pathways seems to be required in the development of CAC. There is also an emerging understanding that commensal and/or pathogenic bacteria can promote tumorigenesis, through T cell mediated inflammation. Using specific transgenic mice (villin-CD98, T cell SMAD7, villin-TLR4) or specific knock-out mice, investigators have identified that derangements in epithelial or innate and adaptive immune pathways can result in CAC. Subtle perturbations in epithelial repair—both too little or too exuberant, can render mice susceptible to tumorigenesis. Summary With the aid of animal models, we have witnessed a rapid expansion of our knowledge of the molecular and immunologic mechanisms underlying inflammatory cancers. Though animal models have contributed a discrete amount of information to our understanding of tumorigenesis in the setting of intestinal inflammation it is clear that no single animal model will be able to adequately recapitulate the pathogenesis of complex CRCs, but each model gets us one step closer to comprehending the nature of CAC. PMID:22614440

Keratin-6 driven ODC expression to hair follicle keratinocytes enhances stemness and tumorigenesis by negatively regulating Notch

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

Arumugam, Aadithya; Weng, Zhiping; Chaudhary, Sandeep C.

Highlights: • Targeting ODC to hair follicle augments skin carcinogenesis and invasive SCCs. • Hair follicle ODC expands stem cell compartment carrying CD34{sup +}/K15{sup +}/p63{sup +} keratinocytes. • Negatively regulated Notch1 is associated with expansion of stem cell compartment. - Abstract: Over-expression of ornithine decarboxylase (ODC) is known to be involved in the epidermal carcinogenesis. However, the mechanism by which it enhances skin carcinogenesis remains undefined. Recently, role of stem cells localized in various epidermal compartments has been shown in the pathogenesis of skin cancer. To direct ODC expression in distinct epidermal compartments, we have developed keratin 6 (K6)-ODC/SKH-1 andmore » keratin 14 (K14)-ODC/SKH-1 mice and employed them to investigate the role of ODC directed to these epidermal compartments on UVB-induced carcinogenesis. K6-driven ODC over-expression directed to outer root sheath (ORS) of hair follicle was more effective in augmenting tumorigenesis as compared to mice where K14-driven ODC expression was directed to inter-follicular epidermal keratinocytes. Chronically UVB-irradiated K6-ODC/SKH-1 developed 15 ± 2.5 tumors/mouse whereas K14-ODC/SKH-1 developed only 6.8 ± 1.5 tumors/mouse. K6-ODC/SKH-1 showed augmented UVB-induced proliferation and much higher pro-inflammatory responses than K14-ODC/SKH-1 mice. Tumors induced in K6-ODC/SKH-1 were rapidly growing, invasive and ulcerative squamous cell carcinoma (SCC) showing decreased expression of epidermal polarity marker E-cadherin and enhanced mesenchymal marker, fibronectin. Interestingly, the number of CD34/CK15/p63 positive stem-like cells was significantly higher in chronically UVB-irradiated K6-ODC/SKH-1 as compared to K14-ODC/SKH-1 mice. Reduced Notch1 expression was correlated with the expansion of stem cell compartment in these animals. However, other signaling pathways such as DNA damage response or mTOR signaling pathways were not significantly different in tumors induced in these two murine models suggesting the specificity of Notch pathway in this regard. These data provide a novel role of ODC in augmenting tumorigenesis via negatively regulated Notch-mediated expansion of stem cell compartment.« less

BH3-only protein BIM: An emerging target in chemotherapy.

PubMed

Shukla, Shatrunajay; Saxena, Sugandh; Singh, Brijesh Kumar; Kakkar, Poonam

2017-12-01

BH3-only proteins constitute major proportion of pro-apoptotic members of B-cell lymphoma 2 (Bcl-2) family of apoptotic regulatory proteins and participate in embryonic development, tissue homeostasis and immunity. Absence of BH3-only proteins contributes to autoimmune disorders and tumorigenesis. Bim (Bcl-2 Interacting Mediator of cell death), most important member of BH3-only proteins, shares a BH3-only domain (9-16 aa) among 4 domains (BH1-BH4) of Bcl-2 family proteins and highly pro-apoptotic in nature. Bim initiates the intrinsic apoptotic pathway under both physiological and patho-physiological conditions. Reduction in Bim expression was found to be associated with tumor promotion and autoimmunity, while overexpression inhibited tumor growth and drug resistance as cancer cells suppress Bim expression and stability. Apart from its role in normal homeostasis, Bim has emerged as a central player in regulation of tumorigenesis, therefore gaining attention as a plausible target for chemotherapy. Regulation of Bim expression and stability is complicated and regulated at multiple levels viz. transcriptional, post-transcriptional, post-translational (preferably by phosphorylation and ubiquitination), epigenetic (by promoter acetylation or methylation) including miRNAs. Furthermore, control over Bim expression and stability may be exploited to enhance chemotherapeutic efficacy, overcome drug resistance and select anticancer drug regimen as various chemotherapeutic agents exploit Bim as an executioner of cell death. Owing to its potent anti-tumorigenic activity many BH3 mimetics e.g. ABT-737, ABT-263, obatoclax, AT-101and A-1210477 have been developed and entered in clinical trials. It is more likely that in near future strategies commanding Bim expression and stability ultimately lead to Bim based therapeutic regimen for cancer treatment. Copyright © 2017. Published by Elsevier GmbH.

Abrogation of Gli3 expression suppresses the growth of colon cancer cells via activation of p53

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

Kang, Han Na; Oh, Sang Cheul; Kim, Jun Suk

2012-03-10

p53, the major human tumor suppressor, appears to be related to sonic hedgehog (Shh)-Gli-mediated tumorigenesis. However, the role of p53 in tumor progression by the Shh-Gli signaling pathway is poorly understood. Herein we investigated the critical regulation of Gli3-p53 in tumorigenesis of colon cancer cells and the molecular mechanisms underlying these effects. RT-PCR analysis indicated that the mRNA level of Shh and Gli3 in colon tumor tissues was significantly higher than corresponding normal tissues (P < 0.001). The inhibition of Gli3 by treatment with Gli3 siRNA resulted in a clear decrease in cell proliferation and enhanced the level of expressionmore » of p53 proteins compared to treatment with control siRNA. The half-life of p53 was dramatically increased by treatment with Gli3 siRNA. In addition, treatment with MG132 blocked MDM2-mediated p53 ubiquitination and degradation, and led to accumulation of p53 in Gli3 siRNA-overexpressing cells. Importantly, ectopic expression of p53 siRNA reduced the ability of Gli3 siRNA to suppress proliferation of those cells compared with the cells treated with Gli3 siRNA alone. Moreover, Gli3 siRNA sensitized colon cancer cells to treatment with anti-cancer agents (5-FU and bevacizumab). Taken together, our studies demonstrate that loss of Gli3 signaling leads to disruption of the MDM2-p53 interaction and strongly potentiate p53-dependent cell growth inhibition in colon cancer cells, indicating a basis for the rational use of Gli3 antagonists as a novel treatment option for colon cancer.« less

Western diet enhances intestinal tumorigenesis in Min/+ mice, associating with mucosal metabolic and inflammatory stress and loss of Apc heterozygosity.

PubMed

Niku, Mikael; Pajari, Anne-Maria; Sarantaus, Laura; Päivärinta, Essi; Storvik, Markus; Heiman-Lindh, Anu; Suokas, Santeri; Nyström, Minna; Mutanen, Marja

2017-01-01

Western-type diet (WD) is a risk factor for colorectal cancer, but the underlying mechanisms are poorly understood. We investigated the interaction of WD and heterozygous mutation in the Apc gene on adenoma formation and metabolic and immunological changes in the histologically normal intestinal mucosa of Apc Min/+ (Min/+) mice. The diet used was high in saturated fat and low in calcium, vitamin D, fiber and folate. The number of adenomas was twofold higher in the WD mice compared to controls, but adenoma size, proliferation or apoptosis did not differ. The ratio of the Min to wild-type allele was higher in the WD mice, indicating accelerated loss of Apc heterozygosity (LOH). Densities of intraepithelial CD3ε + T lymphocytes and of mucosal FoxP3 + regulatory T cells were higher in the WD mice, implying inflammatory changes. Western blot analyses from the mucosa of the WD mice showed suppressed activation of the ERK and AKT pathways and a tendency for reduced activation of the mTOR pathway as measured in phosphoS6/S6 levels. The expression of pyruvate dehydrogenase kinase 4 was up-regulated in both mRNA and protein levels. Gene expression analyses showed changes in oxidation/reduction, fatty acid and monosaccharide metabolic pathways, tissue organization, cell fate and regulation of apoptosis. Together, our results suggest that the high-risk Western diet primes the intestine to tumorigenesis through synergistic effects in energy metabolism, inflammation and oxidative stress, which culminate in the acceleration of LOH of the Apc gene. Copyright © 2016 Elsevier Inc. All rights reserved.

Nr-CAM is a target gene of the beta-catenin/LEF-1 pathway in melanoma and colon cancer and its expression enhances motility and confers tumorigenesis.

PubMed

Conacci-Sorrell, Maralice E; Ben-Yedidia, Tamar; Shtutman, Michael; Feinstein, Elena; Einat, Paz; Ben-Ze'ev, Avri

2002-08-15

beta-catenin and plakoglobin (gamma-catenin) are homologous molecules involved in cell adhesion, linking cadherin receptors to the cytoskeleton. beta-catenin is also a key component of the Wnt pathway by being a coactivator of LEF/TCF transcription factors. To identify novel target genes induced by beta-catenin and/or plakoglobin, DNA microarray analysis was carried out with RNA from cells overexpressing either protein. This analysis revealed that Nr-CAM is the gene most extensively induced by both catenins. Overexpression of either beta-catenin or plakoglobin induced Nr-CAM in a variety of cell types and the LEF/TCF binding sites in the Nr-CAM promoter were required for its activation by catenins. Retroviral transduction of Nr-CAM into NIH3T3 cells stimulated cell growth, enhanced motility, induced transformation, and produced rapidly growing tumors in nude mice. Nr-CAM and LEF-1 expression was elevated in human colon cancer tissue and cell lines and in human malignant melanoma cell lines but not in melanocytes or normal colon tissue. Dominant negative LEF-1 decreased Nr-CAM expression and antibodies to Nr-CAM inhibited the motility of B16 melanoma cells. The results indicate that induction of Nr-CAM transcription by beta-catenin or plakoglobin plays a role in melanoma and colon cancer tumorigenesis, probably by promoting cell growth and motility.

Urokinase-type Plasminogen Activator Resulting from Endometrial Carcinogenesis Enhances Tumor Invasion and Correlates with Poor Outcome of Endometrial Carcinoma Patients

PubMed Central

Huang, Chia-Yen; Chang, Ming-Cheng; Huang, Wei-Yun; Huang, Ching-Ting; Tang, Yu-Chien; Huang, Hsien-Da; Kuo, Kuan-Ting; Chen, Chi-An; Cheng, Wen-Fang

2015-01-01

The purpose of this study was to identify the dysregulated genes involved in the tumorigenesis and progression of endometrial endometrioid adenocarcinoma (EEC), and their possible mechanisms. Endometrial specimens including normal endometrial tissues, atypical endometrial hyperplasia, and EEC were analyzed. The expression profiles were compared using GeneChip Array. The gene expression levels were determined by real-time RT-PCR in the training and testing sets to correlate the clinico-pathological parameters of EEC. Immunoblotting, in vitro cell migration and invasion assays were performed in human endometrial cancer cell lines and their transfectants. In microarray analysis, seven dysregulated genes were identified. Only the levels of urokinase-type plasminogen activator (uPA) were higher in EEC with deep myometrial invasion, positive lympho-vascular space invasion, lymph node metastasis, and advanced stages. After multivariate analysis, uPA was the only independent poor prognostic factor for disease-free survival in the EEC patients (hazard ratio: 4.65, p = 0.03). uPA may enhance the migratory and invasive capabilities of endometrial tumor cells by the phosphorylation of ERK1/2, Akt and p38 molecules. uPA is a dysregulated gene involved in the tumorigenesis, bio-pathological features and outcomes of EEC. uPA may be a potential molecule and target for the detection and treatment of EEC. PMID:26033187

Computational identification of mutually exclusive transcriptional drivers dysregulating metastatic microRNAs in prostate cancer

PubMed Central

Xue, Mengzhu; Liu, Haiyue; Zhang, Liwen; Chang, Hongyuan; Liu, Yuwei; Du, Shaowei; Yang, Yingqun; Wang, Peng

2017-01-01

Androgen-ablation therapies, which are the standard treatment for metastatic prostate cancer, invariably lead to acquired resistance. Hence, a systematic identification of additional drivers may provide useful insights into the development of effective therapies. Numerous microRNAs that are critical for metastasis are dysregulated in metastatic prostate cancer, but the underlying molecular mechanism is poorly understood. We perform an integrative analysis of transcription factor (TF) and microRNA expression profiles and computationally identify three master TFs, AR, HOXC6 and NKX2-2, which induce the aberrant metastatic microRNA expression in a mutually exclusive fashion. Experimental validations confirm that the three TFs co-dysregulate a large number of metastasis-associated microRNAs. Moreover, their overexpression substantially enhances cell motility and is consistently associated with a poor clinical outcome. Finally, the mutually exclusive overexpression between AR, HOXC6 and NKX2-2 is preserved across various tissues and cancers, suggesting that mutual exclusivity may represent an intrinsic characteristic of driver TFs during tumorigenesis. PMID:28397780

Melatonin Inhibits Reactive Oxygen Species-Driven Proliferation, Epithelial-Mesenchymal Transition, and Vasculogenic Mimicry in Oral Cancer

PubMed Central

Liu, Rui; Wang, Hui-li; Deng, Man-jing; Wen, Xiu-jie; Mo, Yuan-yuan; Chen, Fa-ming; Zou, Chun-li; Duan, Wei-feng

2018-01-01

Globally, oral cancer is the most common type of head and neck cancers. Melatonin elicits inhibitory effects on oral cancer; however, the biological function of melatonin and underlying mechanisms remain largely unknown. In this study, we found that melatonin impaired the proliferation and apoptosis resistance of oral cancer cells by inactivating ROS-dependent Akt signaling, involving in downregulation of cyclin D1, PCNA, and Bcl-2 and upregulation of Bax. Melatonin inhibited the migration and invasion of oral cancer cells by repressing ROS-activated Akt signaling, implicating with the reduction of Snail and Vimentin and the enhancement of E-cadherin. Moreover, melatonin hampered vasculogenic mimicry of oral cancer cells through blockage of ROS-activated extracellular-regulated protein kinases (ERKs) and Akt pathways involving the hypoxia-inducible factor 1α. Consistently, melatonin retarded tumorigenesis of oral cancer in vivo. Overall, these findings indicated that melatonin exerts antisurvival, antimotility, and antiangiogenesis effects on oral cancer partly by suppressing ROS-reliant Akt or ERK signaling. PMID:29725496

Melatonin Inhibits Reactive Oxygen Species-Driven Proliferation, Epithelial-Mesenchymal Transition, and Vasculogenic Mimicry in Oral Cancer.

PubMed

Liu, Rui; Wang, Hui-Li; Deng, Man-Jing; Wen, Xiu-Jie; Mo, Yuan-Yuan; Chen, Fa-Ming; Zou, Chun-Li; Duan, Wei-Feng; Li, Lei; Nie, Xin

2018-01-01

Globally, oral cancer is the most common type of head and neck cancers. Melatonin elicits inhibitory effects on oral cancer; however, the biological function of melatonin and underlying mechanisms remain largely unknown. In this study, we found that melatonin impaired the proliferation and apoptosis resistance of oral cancer cells by inactivating ROS-dependent Akt signaling, involving in downregulation of cyclin D1, PCNA, and Bcl-2 and upregulation of Bax. Melatonin inhibited the migration and invasion of oral cancer cells by repressing ROS-activated Akt signaling, implicating with the reduction of Snail and Vimentin and the enhancement of E-cadherin. Moreover, melatonin hampered vasculogenic mimicry of oral cancer cells through blockage of ROS-activated extracellular-regulated protein kinases (ERKs) and Akt pathways involving the hypoxia-inducible factor 1 α . Consistently, melatonin retarded tumorigenesis of oral cancer in vivo . Overall, these findings indicated that melatonin exerts antisurvival, antimotility, and antiangiogenesis effects on oral cancer partly by suppressing ROS-reliant Akt or ERK signaling.

Enhancing early bladder cancer detection with fluorescence-guided endoscopic optical coherence tomography

NASA Astrophysics Data System (ADS)

Pan, Y. T.; Xie, T. Q.; Du, C. W.; Bastacky, S.; Meyers, S.; Zeidel, M. L.

2003-12-01

We report an experimental study of the possibility of enhancing early bladder cancer diagnosis with fluorescence-image-guided endoscopic optical coherence tomography (OCT). After the intravesical instillation of a 10% solution of 5-aminolevulinic acid, simultaneous fluorescence imaging (excitation of 380-420 nm, emission of 620-700 nm) and OCT are performed on rat bladders to identify the photochemical and morphological changes associated with uroepithelial tumorigenesis. The preliminary results of our ex vivo study reveal that both fluorescence and OCT can identify early uroepithelial cancers, and OCT can detect precancerous lesions (e.g., hyperplasia) that fluorescence may miss. This suggests that a cystoscope combining 5-aminolevulinic acid fluorescence and OCT imaging has the potential to enhance the efficiency and sensitivity of early bladder cancer diagnosis.

Genome-wide transcriptional profiling of human glioblastoma cells in response to ITE treatment.

PubMed

Kang, Bo; Zhou, Yanwen; Zheng, Min; Wang, Ying-Jie

2015-09-01

A ligand-activated transcription factor aryl hydrocarbon receptor (AhR) is recently revealed to play a key role in embryogenesis and tumorigenesis (Feng et al. [1], Safe et al. [2]) and 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) (Song et al. [3]) is an endogenous AhR ligand that possesses anti-tumor activity. In order to gain insights into how ITE acts via the AhR in embryogenesis and tumorigenesis, we analyzed the genome-wide transcriptional profiles of the following three groups of cells: the human glioblastoma U87 parental cells, U87 tumor sphere cells treated with vehicle (DMSO) and U87 tumor sphere cells treated with ITE. Here, we provide the details of the sample gathering strategy and show the quality controls and the analyses associated with our gene array data deposited into the Gene Expression Omnibus (GEO) under the accession code of GSE67986.

Rescue from replication stress during mitosis.

PubMed

Fragkos, Michalis; Naim, Valeria

2017-04-03

Genomic instability is a hallmark of cancer and a common feature of human disorders, characterized by growth defects, neurodegeneration, cancer predisposition, and aging. Recent evidence has shown that DNA replication stress is a major driver of genomic instability and tumorigenesis. Cells can undergo mitosis with under-replicated DNA or unresolved DNA structures, and specific pathways are dedicated to resolving these structures during mitosis, suggesting that mitotic rescue from replication stress (MRRS) is a key process influencing genome stability and cellular homeostasis. Deregulation of MRRS following oncogene activation or loss-of-function of caretaker genes may be the cause of chromosomal aberrations that promote cancer initiation and progression. In this review, we discuss the causes and consequences of replication stress, focusing on its persistence in mitosis as well as the mechanisms and factors involved in its resolution, and the potential impact of incomplete replication or aberrant MRRS on tumorigenesis, aging and disease.

Rescue from replication stress during mitosis

PubMed Central

Naim, Valeria

2017-01-01

ABSTRACT Genomic instability is a hallmark of cancer and a common feature of human disorders, characterized by growth defects, neurodegeneration, cancer predisposition, and aging. Recent evidence has shown that DNA replication stress is a major driver of genomic instability and tumorigenesis. Cells can undergo mitosis with under-replicated DNA or unresolved DNA structures, and specific pathways are dedicated to resolving these structures during mitosis, suggesting that mitotic rescue from replication stress (MRRS) is a key process influencing genome stability and cellular homeostasis. Deregulation of MRRS following oncogene activation or loss-of-function of caretaker genes may be the cause of chromosomal aberrations that promote cancer initiation and progression. In this review, we discuss the causes and consequences of replication stress, focusing on its persistence in mitosis as well as the mechanisms and factors involved in its resolution, and the potential impact of incomplete replication or aberrant MRRS on tumorigenesis, aging and disease. PMID:28166452

Balancing Between Aging and Cancer: Molecular Genetics Meets Traditional Chinese Medicine.

PubMed

Liu, Jing; Peng, Lei; Huang, Wenhui; Li, Zhiming; Pan, Jun; Sang, Lei; Lu, Siqian; Zhang, Jihong; Li, Wanyi; Luo, Ying

2017-09-01

The biological consequences of cellular senescence and immortalization in aging and cancer are in conflict. Organisms have developed common cellular signaling pathways and surveillance mechanisms to control the processing of aging against tumorigenesis. The imbalance of any signals involved in this process may result in either premature aging or tumorigenesis and reduce the life span of the organism. In contrast, the balance between aging and tumorigenesis at a higher level (homeostatic-balance) may benefit the organism with tumor-free longevity. The focus of this perspective is to review the literature on the balance between "Yin" and "Yang" in traditional Chinese medicine. Modern cellular and molecular techniques now permit a more robust system to screen herbs in traditional Chinese medicine for their activity in balancing aging and tumorigenesis. The understanding of the crosstalk between aging and tumorigenesis and new perspectives on the application of Chinese medicine might shed light on anti-aging and tumor-free strategies. J. Cell. Biochem. 118: 2581-2586, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Functional Analysis of Interactions Between 53BP1, BRCA1 and p53

DTIC Science & Technology

2004-07-01

deficiency synergize in tumorigenesis. Furthermore, the loss of a single 53BP1 allele enhances the susceptibility to cancer in the absence of p53. 14...specific antibodies against these sites and showed that at least two of them (S25 and S29) are phosphorylated in vivo by ATM, the kinase mutated in cancer ...characterized by chromosomal aberrations, genetic instability and cancer predisposition. +HU 153BP1 Fig. 5: Lack of 53BP1 prevents the efficient accumulation

The Role of Retinal Determination Gene Network (RDGN) in Hormone Signaling Transduction and Prostate Tumorigenesis

DTIC Science & Technology

2012-10-01

support with our hypothesis, expressions of AR co-repressors (48-50), HDAC1, HDAC3 or SirT1 inhibit the ligand-induced AR activation at different...signaling and androgen-dependent growth. We hypothesis that DACH1/Six1/Eya pathway is an endogenous regulator of AR trans- activation and contributes to...mechanism. Inhibitory function of Eya1 on AR transactivation required a phosphates activity and could be enhanced by ectopic expression of co-repressors

MicroRNA dynamics in the stages of tumorigenesis correlate with hallmark capabilities of cancer.

PubMed

Olson, Peter; Lu, Jun; Zhang, Hao; Shai, Anny; Chun, Matthew G; Wang, Yucheng; Libutti, Steven K; Nakakura, Eric K; Golub, Todd R; Hanahan, Douglas

2009-09-15

While altered expression of microRNAs (miRs) in tumors has been well documented, it remains unclear how the miR transcriptome intersects neoplastic progression. By profiling the miR transcriptome we identified miR expression signatures associated with steps in tumorigenesis and the acquisition of hallmark capabilities in a prototypical mouse model of cancer. Metastases and a rare subset of primary tumors shared a distinct miR signature, implicating a discrete lineage for metastatic tumors. The miR-200 family is strongly down-regulated in metastases and met-like primary tumors, thereby relieving repression of the mesenchymal transcription factor Zeb1, which in turn suppresses E-cadherin. Treatment with a clinically approved angiogenesis inhibitor normalized angiogenic signature miRs in primary tumors, while altering expression of metastatic signature miRs similarly to liver metastases, suggesting their involvement in adaptive resistance to anti-angiogenic therapy via enhanced metastasis. Many of the miR changes associated with specific stages and hallmark capabilities in the mouse model are similarly altered in human tumors, including cognate pancreatic neuroendocrine tumors, implying a generality.

The emerging role and targetability of the TCA cycle in cancer metabolism.

PubMed

Anderson, Nicole M; Mucka, Patrick; Kern, Joseph G; Feng, Hui

2018-02-01

The tricarboxylic acid (TCA) cycle is a central route for oxidative phosphorylation in cells, and fulfills their bioenergetic, biosynthetic, and redox balance requirements. Despite early dogma that cancer cells bypass the TCA cycle and primarily utilize aerobic glycolysis, emerging evidence demonstrates that certain cancer cells, especially those with deregulated oncogene and tumor suppressor expression, rely heavily on the TCA cycle for energy production and macromolecule synthesis. As the field progresses, the importance of aberrant TCA cycle function in tumorigenesis and the potentials of applying small molecule inhibitors to perturb the enhanced cycle function for cancer treatment start to evolve. In this review, we summarize current knowledge about the fuels feeding the cycle, effects of oncogenes and tumor suppressors on fuel and cycle usage, common genetic alterations and deregulation of cycle enzymes, and potential therapeutic opportunities for targeting the TCA cycle in cancer cells. With the application of advanced technology and in vivo model organism studies, it is our hope that studies of this previously overlooked biochemical hub will provide fresh insights into cancer metabolism and tumorigenesis, subsequently revealing vulnerabilities for therapeutic interventions in various cancer types.

L1 Retrotransposon Heterogeneity in Ovarian Tumor Cell Evolution.

PubMed

Nguyen, Thu H M; Carreira, Patricia E; Sanchez-Luque, Francisco J; Schauer, Stephanie N; Fagg, Allister C; Richardson, Sandra R; Davies, Claire M; Jesuadian, J Samuel; Kempen, Marie-Jeanne H C; Troskie, Robin-Lee; James, Cini; Beaven, Elizabeth A; Wallis, Tristan P; Coward, Jermaine I G; Chetty, Naven P; Crandon, Alexander J; Venter, Deon J; Armes, Jane E; Perrin, Lewis C; Hooper, John D; Ewing, Adam D; Upton, Kyle R; Faulkner, Geoffrey J

2018-06-26

LINE-1 (L1) retrotransposons are a source of insertional mutagenesis in tumor cells. However, the clinical significance of L1 mobilization during tumorigenesis remains unclear. Here, we applied retrotransposon capture sequencing (RC-seq) to multiple single-cell clones isolated from five ovarian cancer cell lines and HeLa cells and detected endogenous L1 retrotransposition in vitro. We then applied RC-seq to ovarian tumor and matched blood samples from 19 patients and identified 88 tumor-specific L1 insertions. In one tumor, an intronic de novo L1 insertion supplied a novel cis-enhancer to the putative chemoresistance gene STC1. Notably, the tumor subclone carrying the STC1 L1 mutation increased in prevalence after chemotherapy, further increasing STC1 expression. We also identified hypomethylated donor L1s responsible for new L1 insertions in tumors and cultivated cancer cells. These congruent in vitro and in vivo results highlight L1 insertional mutagenesis as a common component of ovarian tumorigenesis and cancer genome heterogeneity. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Endoplasmic reticulum-Golgi intermediate compartment protein 3 knockdown suppresses lung cancer through endoplasmic reticulum stress-induced autophagy.

PubMed

Hong, Seong-Ho; Chang, Seung-Hee; Cho, Kyung-Cho; Kim, Sanghwa; Park, Sungjin; Lee, Ah Young; Jiang, Hu-Lin; Kim, Hyeon-Jeong; Lee, Somin; Yu, Kyeong-Nam; Seo, Hwi Won; Chae, Chanhee; Kim, Kwang Pyo; Park, Jongsun; Cho, Myung-Haing

2016-10-04

Trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus is elevated in cancer cells. Therefore, proteins of the ER-Golgi intermediate compartment (ERGIC) attract significant attention as targets for cancer treatment. Enhanced cancer cell growth and epithelial-mesenchymal transition by ERGICs correlates with poor-prognosis of lung cancer. This prompted us to assess whether knockdown of ERGIC3 may decrease lung cancer growth. To test the hypothesis, the effects of ERGIC3 short hairpin RNA (shERGIC3) on ER stress-induced cell death and lung tumorigenesis were investigated both in vitro and in vivo. Knockdown of ERGIC3 led to ER stress-induced autophagic cell death and suppression of proliferation in the A549 human lung cancer cell-line. Moreover, non-invasive aerosol-delivery of shERGIC3 using the biocompatible carrier glycerol propoxylate triacrylate and spermine (GPT-SPE) inhibited lung tumorigenesis in the K-rasLA1 murine model of lung cancer. Our data suggest that suppression of ERGIC3 could provide a framework for the development of effective lung cancer therapies.

Precise let-7 expression levels balance organ regeneration against tumor suppression

PubMed Central

Wu, Linwei; Nguyen, Liem H; Zhou, Kejin; de Soysa, T Yvanka; Li, Lin; Miller, Jason B; Tian, Jianmin; Locker, Joseph; Zhang, Shuyuan; Shinoda, Gen; Seligson, Marc T; Zeitels, Lauren R; Acharya, Asha; Wang, Sam C; Mendell, Joshua T; He, Xiaoshun; Nishino, Jinsuke; Morrison, Sean J; Siegwart, Daniel J; Daley, George Q; Shyh-Chang, Ng; Zhu, Hao

2015-01-01

The in vivo roles for even the most intensely studied microRNAs remain poorly defined. Here, analysis of mouse models revealed that let-7, a large and ancient microRNA family, performs tumor suppressive roles at the expense of regeneration. Too little or too much let-7 resulted in compromised protection against cancer or tissue damage, respectively. Modest let-7 overexpression abrogated MYC-driven liver cancer by antagonizing multiple let-7 sensitive oncogenes. However, the same level of overexpression blocked liver regeneration, while let-7 deletion enhanced it, demonstrating that distinct let-7 levels can mediate desirable phenotypes. let-7 dependent regeneration phenotypes resulted from influences on the insulin-PI3K-mTOR pathway. We found that chronic high-dose let-7 overexpression caused liver damage and degeneration, paradoxically leading to tumorigenesis. These dose-dependent roles for let-7 in tissue repair and tumorigenesis rationalize the tight regulation of this microRNA in development, and have important implications for let-7 based therapeutics. DOI: http://dx.doi.org/10.7554/eLife.09431.001 PMID:26445246

CRISPR-Cas9: from Genome Editing to Cancer Research

PubMed Central

Chen, Si; Sun, Heng; Miao, Kai; Deng, Chu-Xia

2016-01-01

Cancer development is a multistep process triggered by innate and acquired mutations, which cause the functional abnormality and determine the initiation and progression of tumorigenesis. Gene editing is a widely used engineering tool for generating mutations that enhance tumorigenesis. The recent developed clustered regularly interspaced short palindromic repeats-CRISPR-associated 9 (CRISPR-Cas9) system renews the genome editing approach into a more convenient and efficient way. By rapidly introducing genetic modifications in cell lines, organs and animals, CRISPR-Cas9 system extends the gene editing into whole genome screening, both in loss-of-function and gain-of-function manners. Meanwhile, the system accelerates the establishment of animal cancer models, promoting in vivo studies for cancer research. Furthermore, CRISPR-Cas9 system is modified into diverse innovative tools for observing the dynamic bioprocesses in cancer studies, such as image tracing for targeted DNA, regulation of transcription activation or repression. Here, we view recent technical advances in the application of CRISPR-Cas9 system in cancer genetics, large-scale cancer driver gene hunting, animal cancer modeling and functional studies. PMID:27994508

Control of Paneth Cell Fate, Intestinal Inflammation, and Tumorigenesis by PKCλ/ι.

PubMed

Nakanishi, Yuki; Reina-Campos, Miguel; Nakanishi, Naoko; Llado, Victoria; Elmen, Lisa; Peterson, Scott; Campos, Alex; De, Surya K; Leitges, Michael; Ikeuchi, Hiroki; Pellecchia, Maurizio; Blumberg, Richard S; Diaz-Meco, Maria T; Moscat, Jorge

2016-09-20

Paneth cells are a highly specialized population of intestinal epithelial cells located in the crypt adjacent to Lgr5(+) stem cells, from which they differentiate through a process that requires downregulation of the Notch pathway. Their ability to store and release antimicrobial peptides protects the host from intestinal pathogens and controls intestinal inflammation. Here, we show that PKCλ/ι is required for Paneth cell differentiation at the level of Atoh1 and Gfi1, through the control of EZH2 stability by direct phosphorylation. The selective inactivation of PKCλ/ι in epithelial cells results in the loss of mature Paneth cells, increased apoptosis and inflammation, and enhanced tumorigenesis. Importantly, PKCλ/ι expression in human Paneth cells decreases with progression of Crohn's disease. Kaplan-Meier survival analysis of colorectal cancer (CRC) patients revealed that low PRKCI levels correlated with significantly worse patient survival rates. Therefore, PKCλ/ι is a negative regulator of intestinal inflammation and cancer through its role in Paneth cell homeostasis. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

SIRT2 deletion enhances KRAS-induced tumorigenesis in vivo by regulating K147 acetylation status.

PubMed

Song, Ha Yong; Biancucci, Marco; Kang, Hong-Jun; O'Callaghan, Carol; Park, Seong-Hoon; Principe, Daniel R; Jiang, Haiyan; Yan, Yufan; Satchell, Karla Fullner; Raparia, Kirtee; Gius, David; Vassilopoulos, Athanassios

2016-12-06

The observation that cellular transformation depends on breaching a crucial KRAS activity threshold, along with the finding that only a small percentage of cellsharboring KRAS mutations are transformed, support the idea that additional, not fully uncovered, regulatory mechanisms may contribute to KRAS activation. Here we report that KrasG12D mice lacking Sirt2 show an aggressive tumorigenic phenotype as compared to KrasG12D mice. This phenotype includes increased proliferation, KRAS acetylation, and activation of RAS downstream signaling markers. Mechanistically, KRAS K147 is identified as a novel SIRT2-specific deacetylation target by mass spectrometry, whereas its acetylation status directly regulates KRAS activity, ultimately exerting an impact on cellular behavior as revealed by cell proliferation, colony formation, and tumor growth. Given the significance of KRAS activity as a driver in tumorigenesis, identification of K147 acetylation as a novel post-translational modification directed by SIRT2 in vivo may provide a better understanding of the mechanistic link regarding the crosstalk between non-genetic and genetic factors in KRAS driven tumors.

Riboflavin Depletion Promotes Tumorigenesis in HEK293T and NIH3T3 Cells by Sustaining Cell Proliferation and Regulating Cell Cycle-Related Gene Transcription.

PubMed

Long, Lin; He, Jian-Zhong; Chen, Ye; Xu, Xiu-E; Liao, Lian-Di; Xie, Yang-Min; Li, En-Min; Xu, Li-Yan

2018-05-07

Riboflavin is an essential component of the human diet and its derivative cofactors play an established role in oxidative metabolism. Riboflavin deficiency has been linked with various human diseases. The objective of this study was to identify whether riboflavin depletion promotes tumorigenesis. HEK293T and NIH3T3 cells were cultured in riboflavin-deficient or riboflavin-sufficient medium and passaged every 48 h. Cells were collected every 5 generations and plate colony formation assays were performed to observe cell proliferation. Subcutaneous tumorigenicity assays in NU/NU mice were used to observe tumorigenicity of riboflavin-depleted HEK293T cells. Mechanistically, gene expression profiling and gene ontology analysis were used to identify abnormally expressed genes induced by riboflavin depletion. Western blot analyses, cell cycle analyses, and chromatin immunoprecipitation were used to validate the expression of cell cycle-related genes. Plate colony formation of NIH3T3 and HEK293T cell lines was enhanced >2-fold when cultured in riboflavin-deficient medium for 10-20 generations. Moreover, we observed enhanced subcutaneous tumorigenicity in NU/NU mice following injection of riboflavin-depleted compared with normal HEK293T cells (55.6% compared with 0.0% tumor formation, respectively). Gene expression profiling and gene ontology analysis revealed that riboflavin depletion induced the expression of cell cycle-related genes. Validation experiments also found that riboflavin depletion decreased p21 and p27 protein levels by ∼20%, and increased cell cycle-related and expression-elevated protein in tumor (CREPT) protein expression >2-fold, resulting in cyclin D1 and CDK4 levels being increased ∼1.5-fold, and cell cycle acceleration. We also observed that riboflavin depletion decreased intracellular riboflavin levels by 20% and upregulated expression of riboflavin transporter genes, particularly SLC52A3, and that the changes in CREPT and SLC52A3 correlated with specific epigenetic changes in their promoters in riboflavin-depleted HEK293T cells. Riboflavin depletion contributes to HEK293T and NIH3T3 cell tumorigenesis and may be a risk factor for tumor development.

Protein kinase D1 stimulates proliferation and enhances tumorigenesis of MCF-7 human breast cancer cells through a MEK/ERK-dependent signaling pathway

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

Karam, Manale; Legay, Christine; Auclair, Christian

2012-03-10

Protein kinase D1, PKD1, is a novel serine/threonine kinase whose altered expression and dysregulation in many tumors as well as its activation by several mitogens suggest that this protein could regulate proliferation and tumorigenesis. Nevertheless, the precise signaling pathways used are still unclear and the potential direct role of PKD1 in tumor development and progression has not been yet investigated. In order to clarify the role of PKD1 in cell proliferation and tumorigenesis, we studied the effects of PKD1 overexpression in a human adenocarcinoma breast cancer cell line, MCF-7 cells. We demonstrated that overexpression of PKD1 specifically promotes MCF-7 cellmore » proliferation through accelerating G0/G1 to S phase transition of the cell cycle. Moreover, inhibition of endogenous PKD1 significantly reduced cell proliferation. Taken together, these results clearly strengthen the regulatory role of PKD1 in cell growth. We also demonstrated that overexpression of PKD1 specifically diminished serum- and anchorage-dependence for proliferation and survival in vitro and allowed MCF-7 cells to form tumors in vivo. Thus, all these data highlight the central role of PKD1 in biological processes which are hallmarks of malignant transformation. Analysis of two major signaling pathways implicated in MCF-7 cell proliferation showed that PKD1 overexpression significantly increased ERK1/2 phosphorylation state without affecting Akt phosphorylation. Moreover, PKD1 overexpression-stimulated cell proliferation and anchorage-independent growth were totally impaired by inhibition of the MEK/ERK kinase cascade. However, neither of these effects was affected by blocking the PI 3-kinase/Akt signaling pathway. Thus, the MEK/ERK signaling appears to be a determining pathway mediating the biological effects of PKD1 in MCF-7 cells. Taken together, all these data demonstrate that PKD1 overexpression increases the aggressiveness of MCF-7 breast cancer cells through enhancing their oncogenic properties and would, therefore, define PKD1 as a potentially new promising anti-tumor therapeutic target.« less

Stromal adipocyte enhancer-binding protein (AEBP1) promotes mammary epithelial cell hyperplasia via proinflammatory and hedgehog signaling.

PubMed

Holloway, Ryan W; Bogachev, Oleg; Bharadwaj, Alamelu G; McCluskey, Greg D; Majdalawieh, Amin F; Zhang, Lei; Ro, Hyo-Sung

2012-11-09

Disruption of mammary stromal-epithelial communication leads to aberrant mammary gland development and induces mammary tumorigenesis. Macrophages have been implicated in carcinogenesis primarily by creating an inflammatory microenvironment, which promotes growth of the adjacent epithelial cells. Adipocyte enhancer-binding protein 1 (AEBP1), a novel proinflammatory mediator, promotes macrophage inflammatory responsiveness by inducing NF-κB activity, which has been implicated in tumor cell growth and survival by aberrant sonic hedgehog (Shh) expression. Here, we show that stromal macrophage AEBP1 overexpression results in precocious alveologenesis in the virgin AEBP1 transgenic (AEBP1(TG)) mice, and the onset of ductal hyperplasia was accelerated in AEBP1(TG) mice fed a high fat diet, which induces endogenous AEBP1 expression. Transplantation of AEBP1(TG) bone marrow cells into non-transgenic (AEBP1(NT)) mice resulted in alveolar hyperplasia with up-regulation of NF-κB activity and TNFα expression as displayed in the AEBP1(TG) mammary macrophages and epithelium. Shh expression was induced in AEBP1(TG) macrophages and RAW264.7 macrophages overexpressing AEBP1. The Shh target genes Gli1 and Bmi1 expression was induced in the AEBP1(TG) mammary epithelium and HC11 mammary epithelial cells co-cultured with AEBP1(TG) peritoneal macrophages. The conditioned AEBP1(TG) macrophage culture media promoted NF-κB activity and survival signal, Akt activation, in HC11 cells, whereas such effects were abolished by TNFα neutralizing antibody treatment. Furthermore, HC11 cells displayed enhanced proliferation in response to AEBP1(TG) macrophages and their conditioned media. Our findings highlight the role of AEBP1 in the signaling pathways regulating the cross-talk between mammary epithelium and stroma that could predispose the mammary tissue to tumorigenesis.

Stromal Adipocyte Enhancer-binding Protein (AEBP1) Promotes Mammary Epithelial Cell Hyperplasia via Proinflammatory and Hedgehog Signaling*

PubMed Central

Holloway, Ryan W.; Bogachev, Oleg; Bharadwaj, Alamelu G.; McCluskey, Greg D.; Majdalawieh, Amin F.; Zhang, Lei; Ro, Hyo-Sung

2012-01-01

Disruption of mammary stromal-epithelial communication leads to aberrant mammary gland development and induces mammary tumorigenesis. Macrophages have been implicated in carcinogenesis primarily by creating an inflammatory microenvironment, which promotes growth of the adjacent epithelial cells. Adipocyte enhancer-binding protein 1 (AEBP1), a novel proinflammatory mediator, promotes macrophage inflammatory responsiveness by inducing NF-κB activity, which has been implicated in tumor cell growth and survival by aberrant sonic hedgehog (Shh) expression. Here, we show that stromal macrophage AEBP1 overexpression results in precocious alveologenesis in the virgin AEBP1 transgenic (AEBP1TG) mice, and the onset of ductal hyperplasia was accelerated in AEBP1TG mice fed a high fat diet, which induces endogenous AEBP1 expression. Transplantation of AEBP1TG bone marrow cells into non-transgenic (AEBP1NT) mice resulted in alveolar hyperplasia with up-regulation of NF-κB activity and TNFα expression as displayed in the AEBP1TG mammary macrophages and epithelium. Shh expression was induced in AEBP1TG macrophages and RAW264.7 macrophages overexpressing AEBP1. The Shh target genes Gli1 and Bmi1 expression was induced in the AEBP1TG mammary epithelium and HC11 mammary epithelial cells co-cultured with AEBP1TG peritoneal macrophages. The conditioned AEBP1TG macrophage culture media promoted NF-κB activity and survival signal, Akt activation, in HC11 cells, whereas such effects were abolished by TNFα neutralizing antibody treatment. Furthermore, HC11 cells displayed enhanced proliferation in response to AEBP1TG macrophages and their conditioned media. Our findings highlight the role of AEBP1 in the signaling pathways regulating the cross-talk between mammary epithelium and stroma that could predispose the mammary tissue to tumorigenesis. PMID:22995915

Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity.

PubMed

Liu, Baohui; Lin, Xi; Yang, Xiangsheng; Dong, Huimin; Yue, Xiaojing; Andrade, Kelsey C; Guo, Zhentao; Yang, Jian; Wu, Liquan; Zhu, Xiaonan; Zhang, Shenqi; Tian, Daofeng; Wang, Junmin; Cai, Qiang; Chen, Qizuan; Mao, Shanping; Chen, Qianxue; Chang, Jiang

2015-09-01

Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Downregulation of RND3/RhoE in glioblastoma patients promotes tumorigenesis through augmentation of notch transcriptional complex activity

PubMed Central

Liu, Baohui; Lin, Xi; Yang, Xiangsheng; Dong, Huimin; Yue, Xiaojing; Andrade, Kelsey C; Guo, Zhentao; Yang, Jian; Wu, Liquan; Zhu, Xiaonan; Zhang, Shenqi; Tian, Daofeng; Wang, Junmin; Cai, Qiang; Chen, Qizuan; Mao, Shanping; Chen, Qianxue; Chang, Jiang

2015-01-01

Activation of Notch signaling contributes to glioblastoma multiform (GBM) tumorigenesis. However, the molecular mechanism that promotes the Notch signaling augmentation during GBM genesis remains largely unknown. Identification of new factors that regulate Notch signaling is critical for tumor treatment. The expression levels of RND3 and its clinical implication were analyzed in GBM patients. Identification of RND3 as a novel factor in GBM genesis was demonstrated in vitro by cell experiments and in vivo by a GBM xenograft model. We found that RND3 expression was significantly decreased in human glioblastoma. The levels of RND3 expression were inversely correlated with Notch activity, tumor size, and tumor cell proliferation, and positively correlated with patient survival time. We demonstrated that RND3 functioned as an endogenous repressor of the Notch transcriptional complex. RND3 physically interacted with NICD, CSL, and MAML1, the Notch transcriptional complex factors, promoted NICD ubiquitination, and facilitated the degradation of these cofactor proteins. We further revealed that RND3 facilitated the binding of NICD to FBW7, a ubiquitin ligase, and consequently enhanced NICD protein degradation. Therefore, Notch transcriptional activity was inhibited. Forced expression of RND3 repressed Notch signaling, which led to the inhibition of glioblastoma cell proliferation in vitro and tumor growth in the xenograft mice in vivo. Downregulation of RND3, however, enhanced Notch signaling activity, and subsequently promoted glioma cell proliferation. Inhibition of Notch activity abolished RND3 deficiency-mediated GBM cell proliferation. We conclude that downregulation of RND3 is responsible for the enhancement of Notch activity that promotes glioblastoma genesis. PMID:26108681

Combined aspirin and apatinib treatment suppresses gastric cancer cell proliferation.

PubMed

Zhang, Wei; Tan, Yongsheng; Ma, Heping

2017-11-01

Gastric cancer (GC), one of the types of tumor most prone to malignancy, is characterized by high lethality. Numerous molecular mediators of GC have been identified, including transcription factors, signaling molecules and non-coding RNAs. Recently, inhibition of angiogenesis has emerged as a potential strategy for GC therapy. In the present study, the levels of vascular endothelial growth factor (VEGF), peroxisome proliferator-activated receptor-α (PPARα) and miR-21 in GC patients and individuals without cancer, and the correlation between VEGF and miR-21, and PPARα and miR-21 expression were analyzed. In addition, the GC MKN45 cell line was treated with apatinib (a tyrosine kinase inhibitor) and aspirin (an activator of the transcription factor, PPARα) to investigate the effects of these compounds on tumorigenesis. Furthermore, the present study attempted to elucidate the molecular mechanisms of alteration of GC tumorigenesis by aspirin and apatinib. The results of the current study demonstrated that there was a higher expression of VEGF and miR-21 in GC tissues compared with that in morphologically adjacent normal tissues whereas PPARα expression was decreased. These results were confirmed in vitro , as treatment of MKN45 cells with VEGF resulted in a significant increase in miR-21 expression and a significant reduction in PPARα protein expression. Furthermore, the inhibitory effects of VEGF on PPARα mRNA and protein expression were demonstrated to be mediated by miR-21. Suppression of PPARα protein expression attenuated the inhibitory effects of miR-21 on the level of PPARα mRNA, thereby enhancing tumorigenesis in gastric cancer. Treatment of MKN45 cells with aspirin reduced the levels of phosphorylated AKT by activating PPARα, whereas treatment with apatinib inhibited the phosphorylation of vascular endothelial growth factor receptor 2 and phosphoinositide-3 kinase in MKN45 cells. Finally, treatment of MKN45 cells with apatinib and aspirin suppressed tumorigenesis by inhibiting cell proliferation, migration, invasion and colony formation. Taken together, the results of the present study indicate that treatment with a combination of aspirin and apatinib may be a potential therapeutic strategy for GC treatment.

Shp2 deletion in hepatocytes suppresses hepatocarcinogenesis driven by oncogenic β-Catenin, PIK3CA and MET.

PubMed

Liu, Jacey J; Li, Yanjie; Chen, Wendy S; Liang, Yan; Wang, Gaowei; Zong, Min; Kaneko, Kota; Xu, Ruiyun; Karin, Michael; Feng, Gen-Sheng

2018-07-01

Shp2 is an SH2-tyrosine phosphatase acting downstream of receptor tyrosine kinases (RTKs). Most recent data demonstrated a liver tumor-suppressing role for Shp2, as ablating Shp2 in hepatocytes aggravated hepatocellular carcinoma (HCC) induced by chemical carcinogens or Pten loss. We further investigated the effect of Shp2 deficiency on liver tumorigenesis driven by classical oncoproteins c-Met (receptor for HGF), β-catenin and PIK3CA. We performed hydrodynamic tail vein injection of two pairs of plasmids expressing c-Met and ΔN90-β-catenin (MET/CAT), or c-Met and PIK3CA H1047R (MET/PIK), into WT and Shp2 hep-/- mice. We compared liver tumor loads and investigated the pathogenesis and molecular mechanisms involved using multidisciplinary approaches. Despite the induction of oxidative and metabolic stresses, Shp2 deletion in hepatocytes suppressed hepatocarcinogenesis driven by overexpression of oncoproteins MET/CAT or MET/PIK. Shp2 loss inhibited proliferative signaling from c-Met, Wnt/β-catenin, Ras/Erk and PI3K/Akt pathways, but triggered cell senescence following exogenous expression of the oncogenes. Shp2, acting downstream of RTKs, is positively required for hepatocyte-intrinsic tumorigenic signaling from these oncoproteins, even if Shp2 deficiency induces a tumor-promoting hepatic microenvironment. These data suggest a new and more effective therapeutic strategy for HCCs driven by oncogenic RTKs and other upstream molecules, by inhibiting Shp2 and also suppressing any tumor-enhancing stromal factors produced because of Shp2 inhibition. Primary liver cancer is a malignant disease with poor prognosis, largely because there are limited systemic therapies available. We show here that a cytoplasmic tyrosine phosphatase Shp2 is required for liver tumorigenesis. This tumorigenesis is driven by two oncoproteins that are implicated in human liver cancer. This, together with our previous studies, uncovers the complexity of liver tumorigenesis, by elucidating the pro- and anti-tumor effects of Shp2 in mouse models. This data can be used to guide new therapies. Copyright © 2018 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

The tumorigenic FGFR3-TACC3 gene fusion escapes miR-99a regulation in glioblastoma.

PubMed

Parker, Brittany C; Annala, Matti J; Cogdell, David E; Granberg, Kirsi J; Sun, Yan; Ji, Ping; Li, Xia; Gumin, Joy; Zheng, Hong; Hu, Limei; Yli-Harja, Olli; Haapasalo, Hannu; Visakorpi, Tapio; Liu, Xiuping; Liu, Chang-Gong; Sawaya, Raymond; Fuller, Gregory N; Chen, Kexin; Lang, Frederick F; Nykter, Matti; Zhang, Wei

2013-02-01

Fusion genes are chromosomal aberrations that are found in many cancers and can be used as prognostic markers and drug targets in clinical practice. Fusions can lead to production of oncogenic fusion proteins or to enhanced expression of oncogenes. Several recent studies have reported that some fusion genes can escape microRNA regulation via 3'-untranslated region (3'-UTR) deletion. We performed whole transcriptome sequencing to identify fusion genes in glioma and discovered FGFR3-TACC3 fusions in 4 of 48 glioblastoma samples from patients both of mixed European and of Asian descent, but not in any of 43 low-grade glioma samples tested. The fusion, caused by tandem duplication on 4p16.3, led to the loss of the 3'-UTR of FGFR3, blocking gene regulation of miR-99a and enhancing expression of the fusion gene. The fusion gene was mutually exclusive with EGFR, PDGFR, or MET amplification. Using cultured glioblastoma cells and a mouse xenograft model, we found that fusion protein expression promoted cell proliferation and tumor progression, while WT FGFR3 protein was not tumorigenic, even under forced overexpression. These results demonstrated that the FGFR3-TACC3 gene fusion is expressed in human cancer and generates an oncogenic protein that promotes tumorigenesis in glioblastoma.

Relative Biological Effectiveness of Energetic Heavy Ions for Intestinal Tumorigenesis Shows Male Preponderance and Radiation Type and Energy Dependence in APC(1638N/+) Mice.

PubMed

Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun; Strawn, Steve J; Thakor, Hemang; Fan, Ziling; Shay, Jerry W; Fornace, Albert J; Datta, Kamal

2016-05-01

There are uncertainties associated with the prediction of colorectal cancer (CRC) risk from highly energetic heavy ion (HZE) radiation. We undertook a comprehensive assessment of intestinal and colonic tumorigenesis induced after exposure to high linear energy transfer (high-LET) HZE radiation spanning a range of doses and LET in a CRC mouse model and compared the results with the effects of low-LET γ radiation. Male and female APC(1638N/+) mice (n=20 mice per group) were whole-body exposed to sham-radiation, γ rays, (12)C, (28)Si, or (56)Fe radiation. For the >1 Gy HZE dose, we used γ-ray equitoxic doses calculated using relative biological effectiveness (RBE) determined previously. The mice were euthanized 150 days after irradiation, and intestinal and colon tumor frequency was scored. The highest number of tumors was observed after (28)Si, followed by (56)Fe and (12)C radiation, and tumorigenesis showed a male preponderance, especially after (28)Si. Analysis showed greater tumorigenesis per unit of radiation (per cGy) at lower doses, suggesting either radiation-induced elimination of target cells or tumorigenesis reaching a saturation point at higher doses. Calculation of RBE for intestinal and colon tumorigenesis showed the highest value with (28)Si, and lower doses showed greater RBE relative to higher doses. We have demonstrated that the RBE of heavy ion radiation-induced intestinal and colon tumorigenesis is related to ion energy, LET, gender, and peak RBE is observed at an LET of 69 keV/μm. Our study has implications for understanding risk to astronauts undertaking long duration space missions. Copyright © 2016 Elsevier Inc. All rights reserved.

Dietary Factors Modulate Colonic Tumorigenesis Through the Interaction of Gut Microbiota and Host Chloride Channels.

PubMed

Zhang, Yong; Kang, Chao; Wang, Xiao-Lan; Zhou, Min; Chen, Meng-Ting; Zhu, Xiao-Hui; Liu, Kai; Wang, Bin; Zhang, Qian-Yong; Zhu, Jun-Dong; Mi, Man-Tian

2018-03-01

In recent decades, the association among diet, gut microbiota, and the risk of colorectal cancer (CRC) has been established. Gut microbiota and associated metabolites, such as bile acids and butyrate, are now known to play a key role in CRC development. The aim of this study is to identify that the progression to CRC is influenced by cholic acid, sodium butyrate, a high-fat diet, or different dose of dihydromyricetin (DMY) interacted with gut microbiota. An AOM/DSS (azoxymethan/dextran sodium sulfate) model is established to study the gut microbiota compsition before and after tumor formation during colitis-induced tumorigenesis. All above dietary factors profoundly influence the composition of gut microbiota and host colonic tumorigenesis. In addition, mice with DMY-modified initial microbiota display different degrees of chemically induced tumorigenesis. Mechanism analysis reveals that gut microbiota-associated chloride channels participated in colon tumorigenesis. Gut microbiota changes occur in the hyperproliferative stage before tumor formation. Gut microbiota and host chloride channels, both of which are regulated by dietary factors, are associated with CRC development. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

YAP promotes tumorigenesis and cisplatin resistance in neuroblastoma.

PubMed

Yang, Chao; Tan, Juan; Zhu, Jun; Wang, Shan; Wei, Guanghui

2017-06-06

The transcriptional co-activator Yes-associated protein (YAP) is essential for Hippo pathway-driven tumorigenesis in various cancers. However, the expression and function of YAP in neuroblastoma remains elusive. Here, we show that YAP was highly expressed in Neuroblastoma (NB) and expression levels correlated with advanced tumor staging. Knockdown of YAP significantly impaired neuroblastoma proliferation, tumorigenesis, and invasion in vitro. Injection of the YAP inhibitor, Peptide 17, dramatically prevented neuroblastoma subcutaneous tumor growth by efficiently downregulating YAP expression in tumors. Additionally, less proliferative and more apoptotic cells were found in the Peptide 17 treatment group. Furthermore, YAP inhibition significantly inhibited cisplatin-resistant neuroblastoma proliferation, tumorigenesis, and invasion in vitro. The combination of Peptide 17 with low-dose cisplatin efficiently impaired cisplatin-resistant NB subcutaneous tumor growth, being as effective as high-dose cisplatin. Notably, the combination therapy caused lesser liver toxicity in mice compared to the high-dose cisplatin treatment group. Collectively, this work identifies YAP as a novel regulator of neuroblastoma proliferation, tumorigenesis, and invasion and indicates that YAP is a potential therapeutic target for cisplatin-resistant neuroblastoma.

Hyaluronan synthase 3 mediated oncogenic action through forming inter-regulation loop with tumor necrosis factor alpha in oral cancer

PubMed Central

Kuo, Yi-Zih; Fang, Wei-Yu; Huang, Cheng-Chih; Tsai, Sen-Tien; Wang, Yi-Ching; Yang, Chih-Li; Wu, Li-Wha

2017-01-01

Hyaluronan (HA) is a major extracellular matrix component. However, its role and mediation in oral cancer remains elusive. Hyaluronan synthase 3 (HAS3), involved in pro-inflammatory short chain HA synthesis, was the predominant synthase in oral cancer cells and tissues. HAS3 overexpression significantly increased oral cancer cell migration, invasion and xenograft tumorigenesis accompanied with the increased expression of tumor necrosis factor alpha (TNF-α) and monocyte chemoattractant protein 1 (MCP-1). Conversely, HAS3 depletion abrogated HAS3-mediated stimulation. HAS3 induced oncogenic actions partly through activating EGFR-SRC signaling. HAS3-derived HA release into extracellular milieu enhanced transendothelial monocyte migration and MCP-1 expression, which was attenuated by anti-HAS3 antibodies or a HAS inhibitor, 4-Methylumbelliferone (4-MU). The NF-κB-binding site III at -1692 to -1682 bp upstream from the transcript 1 start site in HAS3 proximal promoter was the most responsive to TNF-α-stimulated transcription. ChIP-qPCR analysis confirmed the highest NF-κB-p65 enrichment on site III. Increased HAS3 mRNA expression was negatively correlated with the overall survival of oral cancer patients. A concomitant increase of TNF-α, a stimulus for HAS3 expression, with HAS3 expression was not only associated with lymph node metastasis but also negated clinical outcome. Together, HAS3 and TNF-α formed an inter-regulation loop to enhance tumorigenesis in oral cancer. PMID:28107185

Neural-endocrine-immune complex in the central modulation of tumorigenesis: facts, assumptions, and hypotheses.

PubMed

Mravec, Boris; Gidron, Yori; Kukanova, Barbara; Bizik, Jozef; Kiss, Alexander; Hulin, Ivan

2006-11-01

For the precise coordination of systemic functions, the nervous system uses a variety of peripherally and centrally localized receptors, which transmit information from internal and external environments to the central nervous system. Tight interconnections between the immune, nervous, and endocrine systems provide a base for monitoring and consequent modulation of immune system functions by the brain and vice versa. The immune system plays an important role in tumorigenesis. On the basis of rich interconnections between the immune, nervous and endocrine systems, the possibility that the brain may be informed about tumorigenesis is discussed in this review article. Moreover, the eventual modulation of tumorigenesis by central nervous system is also considered. Prospective consequences of the interactions between tumor and brain for diagnosis and therapy of cancer are emphasized.

Tissue-Specific Effects of Reduced β-catenin Expression on Adenomatous Polyposis Coli Mutation-Instigated Tumorigenesis in Mouse Colon and Ovarian Epithelium

PubMed Central

Feng, Ying; Sakamoto, Naoya; Wu, Rong; Liu, Jie-yu; Wiese, Alexandra; Green, Maranne E.; Green, Megan; Akyol, Aytekin; Roy, Badal C.; Zhai, Yali; Cho, Kathleen R.; Fearon, Eric R.

2015-01-01

Adenomatous polyposis coli (APC) inactivating mutations are present in most human colorectal cancers and some other cancers. The APC protein regulates the β-catenin protein pool that functions as a co-activator of T cell factor (TCF)-regulated transcription in Wnt pathway signaling. We studied effects of reduced dosage of the Ctnnb1 gene encoding β-catenin in Apc-mutation-induced colon and ovarian mouse tumorigenesis and cell culture models. Concurrent somatic inactivation of one Ctnnb1 allele, dramatically inhibited Apc mutation-induced colon polyposis and greatly extended Apc-mutant mouse survival. Ctnnb1 hemizygous dose markedly inhibited increases in β-catenin levels in the cytoplasm and nucleus following Apc inactivation in colon epithelium, with attenuated expression of key β-catenin/TCF-regulated target genes, including those encoding the EphB2/B3 receptors, the stem cell marker Lgr5, and Myc, leading to maintenance of crypt compartmentalization and restriction of stem and proliferating cells to the crypt base. A critical threshold for β-catenin levels in TCF-regulated transcription was uncovered for Apc mutation-induced effects in colon epithelium, along with evidence of a feed-forward role for β-catenin in Ctnnb1 gene expression and CTNNB1 transcription. The active β-catenin protein pool was highly sensitive to CTNNB1 transcript levels in colon cancer cells. In mouse ovarian endometrioid adenocarcinomas (OEAs) arising from Apc- and Pten-inactivation, while Ctnnb1 hemizygous dose affected β-catenin levels and some β-catenin/TCF target genes, Myc induction was retained and OEAs arose in a fashion akin to that seen with intact Ctnnb1 gene dose. Our findings indicate Ctnnb1 gene dose exerts tissue-specific differences in Apc mutation-instigated tumorigenesis. Differential expression of selected β-catenin/TCF-regulated genes, such as Myc, likely underlies context-dependent effects of Ctnnb1 gene dosage in tumorigenesis. PMID:26528816

The Effects of Deregulated Cyclin Expression in Mitosis. A Role in Breast Tumorigenesis

DTIC Science & Technology

2006-05-01

At times, mitotic division completely fails resulting in polyploid cells containing double the amount of DNA and centrosomes, thus explaining how...more frequent event that was easily scorable under the experimental conditions. Polyploid cells, themselves unstable, can readily give rise to...anaphase but instead began to decondense chromosomes, resulting in a polyploid cell (supplementary movie 3). This was consistent with our observation

Hormone-induced protection against mammary tumorigenesis is conserved in multiple rat strains and identifies a core gene expression signature induced by pregnancy.

PubMed

Blakely, Collin M; Stoddard, Alexander J; Belka, George K; Dugan, Katherine D; Notarfrancesco, Kathleen L; Moody, Susan E; D'Cruz, Celina M; Chodosh, Lewis A

2006-06-15

Women who have their first child early in life have a substantially lower lifetime risk of breast cancer. The mechanism for this is unknown. Similar to humans, rats exhibit parity-induced protection against mammary tumorigenesis. To explore the basis for this phenomenon, we identified persistent pregnancy-induced changes in mammary gene expression that are tightly associated with protection against tumorigenesis in multiple inbred rat strains. Four inbred rat strains that exhibit marked differences in their intrinsic susceptibilities to carcinogen-induced mammary tumorigenesis were each shown to display significant protection against methylnitrosourea-induced mammary tumorigenesis following treatment with pregnancy levels of estradiol and progesterone. Microarray expression profiling of parous and nulliparous mammary tissue from these four strains yielded a common 70-gene signature. Examination of the genes constituting this signature implicated alterations in transforming growth factor-beta signaling, the extracellular matrix, amphiregulin expression, and the growth hormone/insulin-like growth factor I axis in pregnancy-induced alterations in breast cancer risk. Notably, related molecular changes have been associated with decreased mammographic density, which itself is strongly associated with decreased breast cancer risk. Our findings show that hormone-induced protection against mammary tumorigenesis is widely conserved among divergent rat strains and define a gene expression signature that is tightly correlated with reduced mammary tumor susceptibility as a consequence of a normal developmental event. Given the conservation of this signature, these pathways may contribute to pregnancy-induced protection against breast cancer.

hNaa10p contributes to tumorigenesis by facilitating DNMT1-mediated tumor suppressor gene silencing

PubMed Central

Lee, Chung-Fan; Ou, Derick S.-C.; Lee, Sung-Bau; Chang, Liang-Hao; Lin, Ruo-Kai; Li, Ying-Shiuan; Upadhyay, Anup K.; Cheng, Xiaodong; Wang, Yi-Ching; Hsu, Han-Shui; Hsiao, Michael; Wu, Cheng-Wen; Juan, Li-Jung

2010-01-01

Hypermethylation-mediated tumor suppressor gene silencing plays a crucial role in tumorigenesis. Understanding its underlying mechanism is essential for cancer treatment. Previous studies on human N-α-acetyltransferase 10, NatA catalytic subunit (hNaa10p; also known as human arrest-defective 1 [hARD1]), have generated conflicting results with regard to its role in tumorigenesis. Here we provide multiple lines of evidence indicating that it is oncogenic. We have shown that hNaa10p overexpression correlated with poor survival of human lung cancer patients. In vitro, enforced expression of hNaa10p was sufficient to cause cellular transformation, and siRNA-mediated depletion of hNaa10p impaired cancer cell proliferation in colony assays and xenograft studies. The oncogenic potential of hNaa10p depended on its interaction with DNA methyltransferase 1 (DNMT1). Mechanistically, hNaa10p positively regulated DNMT1 enzymatic activity by facilitating its binding to DNA in vitro and its recruitment to promoters of tumor suppressor genes, such as E-cadherin, in vivo. Consistent with this, interaction between hNaa10p and DNMT1 was required for E-cadherin silencing through promoter CpG methylation, and E-cadherin repression contributed to the oncogenic effects of hNaa10p. Together, our data not only establish hNaa10p as an oncoprotein, but also reveal that it contributes to oncogenesis through modulation of DNMT1 function. PMID:20592467

Autophagy mediates HIF2α degradation and suppresses renal tumorigenesis

PubMed Central

Liu, Xian-De; Yao, Jun; Tripathi, Durga Nand; Ding, Zhiyong; Xu, Yi; Sun, Mianen; Zhang, Jiangwei; Bai, Shanshan; German, Peter; Hoang, Anh; Zhou, Lijun; Jonasch, Darius; Zhang, Xuesong; Conti, Claudio J.; Efstathiou, Eleni; Tannir, Nizar M; Eissa, N. Tony; Mills, Gordon B.; Walker, Cheryl Lyn; Jonasch, Eric

2014-01-01

Autophagy is a conserved process involved in lysosomal degradation of protein aggregates and damaged organelles. The role of autophagy in cancer is a topic of intense debate, and the underlying mechanism is still not clear. The hypoxia inducible factor 2α (HIF2α), an oncogenic transcription factor implicated in renal tumorigenesis, is known to be degraded by the ubiquitin-proteasome system (UPS). Here we report that HIF2α is in part constitutively degraded by autophagy. HIF2α interacts with autophagy-lysosome system components. Inhibition of autophagy increases HIF2α, while induction of autophagy decreases HIF2α. The E3 ligase von Hippel Lindau (VHL) and autophagy receptor protein p62 are required for autophagic degradation of HIF2α. There is a compensatory interaction between the UPS and autophagy in HIF2α degradation. Autophagy inactivation redirects HIF2α to proteasomal degradation, while proteasome inhibition induces autophagy and increases the HIF2α-p62 interaction. Importantly, clear cell renal cell carcinoma (ccRCC) is frequently associated with mono-allelic loss and/or mutation of autophagy related gene ATG7, and low expression level of autophagy genes correlates with ccRCC progression. The protein levels of ATG7 and beclin 1 are also reduced in ccRCC tumors. This study indicates that autophagy plays an anticancer role in ccRCC tumorigenesis, and suggests that constitutive autophagic degradation of HIF2α is a novel tumor suppression mechanism. PMID:24998849

Genome-wide transcriptional profiling of human glioblastoma cells in response to ITE treatment

PubMed Central

Kang, Bo; Zhou, Yanwen; Zheng, Min; Wang, Ying-Jie

2015-01-01

A ligand-activated transcription factor aryl hydrocarbon receptor (AhR) is recently revealed to play a key role in embryogenesis and tumorigenesis (Feng et al. [1], Safe et al. [2]) and 2-(1′H-indole-3′-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) (Song et al. [3]) is an endogenous AhR ligand that possesses anti-tumor activity. In order to gain insights into how ITE acts via the AhR in embryogenesis and tumorigenesis, we analyzed the genome-wide transcriptional profiles of the following three groups of cells: the human glioblastoma U87 parental cells, U87 tumor sphere cells treated with vehicle (DMSO) and U87 tumor sphere cells treated with ITE. Here, we provide the details of the sample gathering strategy and show the quality controls and the analyses associated with our gene array data deposited into the Gene Expression Omnibus (GEO) under the accession code of GSE67986. PMID:26484269

Impaired spermatogenesis and elevated spontaneous tumorigenesis in xeroderma pigmentosum group A gene (Xpa)-deficient mice

PubMed Central

Nakane, Hironobu; Hirota, Seiichi; Brooks, Philip J.; Nakabeppu, Yusaku; Nakatsu, Yoshimichi; Nishimune, Yoshitake; Iino, Akihiro; Tanaka, Kiyoji

2009-01-01

We have reported that xeroderma pigmentosum group A (Xpa) gene-knockout mice [Xpa (−/−) mice] are deficient in nucleotide excision repair (NER) and highly sensitive to UV-induced skin carcinogenesis. Although xeroderma pigmentosum group A patients show growth retardation, immature sexual development, and neurological abnormalities as well as a high incidence of UV-induced skin tumors, Xpa (−/−) mice were physiologically and behaviorally normal. In the present study, we kept Xpa (−/−) mice for two years under specific pathogen-free (SPF) conditions and found that the testis diminished in an age-dependent manner, and degenerating seminiferous tubules and no spermatozoa were detected in the 24-month old Xpa (−/−) mice. In addition, a higher incidence of spontaneous tumorigenesis was observed in the 24-month old Xpa (−/−) mice compared to Xpa (+/+) controls. Xpa (−/−) mice provide a useful model for investigating the aging and internal tumor formation in XP-A patients. PMID:18790090

YAP forms autocrine loops with the ERBB pathway to regulate ovarian cancer initiation and progression

PubMed Central

He, Chunbo; Lv, Xiangmin; Hua, Guohua; Lele, Subodh M; Remmenga, Steven; Dong, Jixin; Davis, John S; Wang, Cheng

2014-01-01

Mechanisms underlying ovarian cancer initiation and progression are unclear. Herein, we report that the Yes-associated protein (YAP), a major effector of the Hippo tumor suppressor pathway, interacts with ERBB signaling pathways to regulate the initiation and progression of ovarian cancer. Immunohistochemistry studies indicate that YAP expression is associated with poor clinical outcomes in patients. Overexpression or constitutive activation of YAP leads to transformation and tumorigenesis in human ovarian surface epithelial cells, and promotes growth of cancer cells in vivo and in vitro. YAP induces expression of EGF receptors (EGFR, ERBB3) and production of EGF-like ligands (HBEGF, NRG1 and NRG2). HBEGF or NRG1, in turn, activates YAP and stimulates cancer cell growth. Knockdown of ERBB3 or HBEGF eliminates YAP effects on cell growth and transformation, while knockdown of YAP abrogates NRG1- and HBEGF-stimulated cell proliferation. Collectively, our study demonstrates the existence of HBEGF&NRGs/ERBBs/YAP/HBEGF&NRGs autocrine loop that controls ovarian cell tumorigenesis and cancer progression. PMID:25798835

Composite regulation of ERK activity dynamics underlying tumour-specific traits in the intestine.

PubMed

Muta, Yu; Fujita, Yoshihisa; Sumiyama, Kenta; Sakurai, Atsuro; Taketo, M Mark; Chiba, Tsutomu; Seno, Hiroshi; Aoki, Kazuhiro; Matsuda, Michiyuki; Imajo, Masamichi

2018-06-05

Acting downstream of many growth factors, extracellular signal-regulated kinase (ERK) plays a pivotal role in regulating cell proliferation and tumorigenesis, where its spatiotemporal dynamics, as well as its strength, determine cellular responses. Here, we uncover the ERK activity dynamics in intestinal epithelial cells (IECs) and their association with tumour characteristics. Intravital imaging identifies two distinct modes of ERK activity, sustained and pulse-like activity, in IECs. The sustained and pulse-like activities depend on ErbB2 and EGFR, respectively. Notably, activation of Wnt signalling, the earliest event in intestinal tumorigenesis, augments EGFR signalling and increases the frequency of ERK activity pulses through controlling the expression of EGFR and its regulators, rendering IECs sensitive to EGFR inhibition. Furthermore, the increased pulse frequency is correlated with increased cell proliferation. Thus, ERK activity dynamics are defined by composite inputs from EGFR and ErbB2 signalling in IECs and their alterations might underlie tumour-specific sensitivity to pharmacological EGFR inhibition.

Multifaceted role of EZH2 in breast and prostate tumorigenesis: epigenetics and beyond.

PubMed

Deb, Gauri; Thakur, Vijay S; Gupta, Sanjay

2013-05-01

Overexpression of EZH2 and other PRC2 subunits, such as SUZ12, is associated with tumor progression and poor prognosis in several human malignancies. Nevertheless, the underlying mechanisms driving aberrant EZH2 expression are poorly understood. This review provides molecular insights into the essential role of EZH2 in breast and prostate tumorigenesis. We addressed the current understanding on the oncogenic role of EZH2, with an emphasis on: (1) the less known PRC2-independent role of EZH2 in gene activation, in addition to its canonical role in transcriptional silencing as a histone methyltransferase catalyzing the trimethylation of histone H3 at lysine 27; (2) causes and consequences of its deregulation in tumor cells and; (3) collaboration of EZH2 with other epigenetic and hormone receptor-mediated oncogenic signaling pathways. We also summarize how EZH2 has emerged as a promising therapeutic target in hormone-refractory cancers and the prospects for integrating EZH2 blockade with available pharmacological inhibitors.

A HIF-LIMD1 negative feedback mechanism mitigates the pro-tumorigenic effects of hypoxia.

PubMed

Foxler, Daniel E; Bridge, Katherine S; Foster, John G; Grevitt, Paul; Curry, Sean; Shah, Kunal M; Davidson, Kathryn M; Nagano, Ai; Gadaleta, Emanuela; Rhys, Hefin I; Kennedy, Paul T; Hermida, Miguel A; Chang, Ting-Yu; Shaw, Peter E; Reynolds, Louise E; McKay, Tristan R; Wang, Hsei-Wei; Ribeiro, Paulo S; Plevin, Michael J; Lagos, Dimitris; Lemoine, Nicholas R; Rajan, Prabhakar; Graham, Trevor A; Chelala, Claude; Hodivala-Dilke, Kairbaan M; Spendlove, Ian; Sharp, Tyson V

2018-06-21

The adaptive cellular response to low oxygen tensions is mediated by the hypoxia-inducible factors (HIFs), a family of heterodimeric transcription factors composed of HIF-α and HIF-β subunits. Prolonged HIF expression is a key contributor to cellular transformation, tumorigenesis and metastasis. As such, HIF degradation under hypoxic conditions is an essential homeostatic and tumour-suppressive mechanism. LIMD1 complexes with PHD2 and VHL in physiological oxygen levels (normoxia) to facilitate proteasomal degradation of the HIF-α subunit. Here, we identify LIMD1 as a HIF-1 target gene, which mediates a previously uncharacterised, negative regulatory feedback mechanism for hypoxic HIF-α degradation by modulating PHD2-LIMD1-VHL complex formation. Hypoxic induction of LIMD1 expression results in increased HIF-α protein degradation, inhibiting HIF-1 target gene expression, tumour growth and vascularisation. Furthermore, we report that copy number variation at the LIMD1 locus occurs in 47.1% of lung adenocarcinoma patients, correlates with enhanced expression of a HIF target gene signature and is a negative prognostic indicator. Taken together, our data open a new field of research into the aetiology, diagnosis and prognosis of LIMD1 -negative lung cancers. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Protein kinase activity of the glycolytic enzyme PGK1 regulates autophagy to promote tumorigenesis.

PubMed

Qian, Xu; Li, Xinjian; Lu, Zhimin

2017-07-03

Macroautophagy/autophagy is a cellular defense response to stress conditions and is crucial for cell homeostasis maintenance. However, the precise mechanism underlying autophagy initiation, especially in response to glutamine deprivation and hypoxia, is yet to be explored. We recently discovered that PGK1 (phosphoglycerate kinase 1), a glycolytic enzyme, functions as a protein kinase, phosphorylating BECN1/Beclin 1 to initiate autophagy. Under glutamine deprivation or hypoxia stimulation, PGK1 is acetylated at K388 by NAA10/ARD1 in an MTOR-inhibition-dependent manner, leading to the interaction between PGK1 and BECN1 and the subsequent phosphorylation of BECN1 at S30 by PGK1. This phosphorylation enhances ATG14-associated PIK3C3/VPS34-BECN1-PIK3R4/VPS15 complex activity, thereby increasing phosphatidylinositol-3-phosphate (PtdIns3P) generation in the initiation stage of autophagy. Furthermore, NAA10-dependent PGK1 acetylation and PGK1-dependent BECN1 phosphorylation are required for glutamine deprivation- and hypoxia-induced autophagy and brain tumor formation. Our work reveals the important dual roles of PGK1 as a glycolytic enzyme and a protein kinase in the mutual regulation of cell metabolism and autophagy in maintaining cell homeostasis.

Relative Biological Effectiveness of Energetic Heavy Ions for Intestinal Tumorigenesis Shows Male Preponderance and Radiation Type and Energy Dependence in APC{sup 1638N/+} Mice

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

Suman, Shubhankar; Kumar, Santosh; Moon, Bo-Hyun

Purpose: There are uncertainties associated with the prediction of colorectal cancer (CRC) risk from highly energetic heavy ion (HZE) radiation. We undertook a comprehensive assessment of intestinal and colonic tumorigenesis induced after exposure to high linear energy transfer (high-LET) HZE radiation spanning a range of doses and LET in a CRC mouse model and compared the results with the effects of low-LET γ radiation. Methods and Materials: Male and female APC{sup 1638N/+} mice (n=20 mice per group) were whole-body exposed to sham-radiation, γ rays, {sup 12}C, {sup 28}Si, or {sup 56}Fe radiation. For the >1 Gy HZE dose, we used γ-ray equitoxicmore » doses calculated using relative biological effectiveness (RBE) determined previously. The mice were euthanized 150 days after irradiation, and intestinal and colon tumor frequency was scored. Results: The highest number of tumors was observed after {sup 28}Si, followed by {sup 56}Fe and {sup 12}C radiation, and tumorigenesis showed a male preponderance, especially after {sup 28}Si. Analysis showed greater tumorigenesis per unit of radiation (per cGy) at lower doses, suggesting either radiation-induced elimination of target cells or tumorigenesis reaching a saturation point at higher doses. Calculation of RBE for intestinal and colon tumorigenesis showed the highest value with {sup 28}Si, and lower doses showed greater RBE relative to higher doses. Conclusions: We have demonstrated that the RBE of heavy ion radiation-induced intestinal and colon tumorigenesis is related to ion energy, LET, gender, and peak RBE is observed at an LET of 69 keV/μm. Our study has implications for understanding risk to astronauts undertaking long duration space missions.« less

A potential role for Helicobacter pylori heat shock protein 60 in gastric tumorigenesis

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

Lin, Chen-Si; School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan; He, Pei-Juin

2010-02-05

Helicobacter pylori has been found to promote the malignant process leading to gastric cancer. Heat shock protein 60 of H. pylori (HpHSP60) was previously been identified as a potent immunogene. This study investigates the role of HpHSP60 in gastric cancer carcinogenesis. The effect of HpHSP60 on cell proliferation, anti-death activity, angiogenesis and cell migration were explored. The results showed that HpHSP60 enhanced migration by gastric cancer cells and promoted tube formation by umbilical vein endothelial cells (HUVECs); however, HpHSP60 did not increase cell proliferation nor was this protein able to rescue gastric cancer cells from death. Moreover, the results alsomore » indicated HpHSP60 had different effects on AGS gastric cancer cells or THP-1 monocytic cells in terms of their expression of pro-inflammatory cytokines, which are known to be important to cancer development. We propose that HpHSP60 may trigger the initiation of carcinogenesis by inducing pro-inflammatory cytokine release and by promoting angiogenesis and metastasis. Thus, this extracellular pathogen-derived HSP60 is potentially a vigorous virulence factor that can act as a carcinogen during gastric tumorigenesis.« less

The role of PIM1/PIM2 kinases in tumors of the male reproductive system.

PubMed

Jiménez-García, Manuel Pedro; Lucena-Cacace, Antonio; Robles-Frías, María José; Narlik-Grassow, Maja; Blanco-Aparicio, Carmen; Carnero, Amancio

2016-11-30

The PIM family of serine/threonine kinases has three highly conserved isoforms (PIM1, PIM2 and PIM3). PIM proteins are regulated through transcription and stability by JAK/STAT pathways and are overexpressed in hematological malignancies and solid tumors. The PIM kinases possess weak oncogenic abilities, but enhance other genes or chemical carcinogens to induce tumors. We generated conditional transgenic mice that overexpress PIM1 or PIM2 in male reproductive organs and analyzed their contribution to tumorigenesis. We found an increase in alterations of sexual organs and hyperplasia in the transgenic mice correlating with inflammation. We also found that PIM1/2 are overexpressed in a subset of human male germ cells and prostate tumors correlating with inflammatory features and stem cell markers. Our data suggest that PIM1/2 kinase overexpression is a common feature of male reproductive organs tumors, which provoke tissue alterations and a large inflammatory response that may act synergistically during the process of tumorigenesis. There is also a correlation with markers of cancer stem cells, which may contribute to the therapy resistance found in tumors overexpressing PIM kinases.

CHIP promotes thyroid cancer proliferation via activation of the MAPK and AKT pathways

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

Zhang, Li; Liu, Lianyong; Department of Endocrinology, Shanghai Punan Hospital, Shanghai 200125

The carboxyl terminus of Hsp70-interacting protein (CHIP) is a U box-type ubiquitin ligase that plays crucial roles in various biological processes, including tumor progression. To date, the functional mechanism of CHIP in thyroid cancer remains unknown. Here, we obtained evidence of upregulation of CHIP in thyroid cancer tissues and cell lines. CHIP overexpression markedly enhanced thyroid cancer cell viability and colony formation in vitro and accelerated tumor growth in vivo. Conversely, CHIP knockdown impaired cell proliferation and tumor growth. Notably, CHIP promoted cell growth through activation of MAPK and AKT pathways, subsequently decreasing p27 and increasing cyclin D1 and p-FOXO3a expression. Ourmore » findings collectively indicate that CHIP functions as an oncogene in thyroid cancer, and is therefore a potential therapeutic target for this disease. - Highlights: • CHIP is significantly upregulated in thyroid cancer cells. • Overexpression of CHIP facilitates proliferation and tumorigenesis of thyroid cancer cells. • Silencing of CHIP inhibits the proliferation and tumorigenesis of thyroid cancer cells. • CHIP promotes thyroid cancer cell proliferation via activating the MAPK and AKT pathways.« less

Stromal cells in breast cancer as a potential therapeutic target

PubMed Central

Dykes, Samantha S.; Hughes, Veronica S.; Wiggins, Jennifer M.; Fasanya, Henrietta O.; Tanaka, Mai; Siemann, Dietmar

2018-01-01

Breast cancer in the United States is the second most commonly diagnosed cancer in women. About 1 in 8 women will develop invasive breast cancer over the course of her lifetime and breast cancer remains the second leading cause of cancer-related death. In pursuit of novel therapeutic strategies, researchers have examined the tumor microenvironment as a potential anti-cancer target. In addition to neoplastic cells, the tumor microenvironment is composed of several critical normal cell types, including fibroblasts, vascular and lymph endothelial cells, osteoclasts, adipocytes, and immune cells. These cells have important roles in healthy tissue stasis, which frequently are altered in tumors. Indeed, tumor-associated stromal cells often contribute to tumorigenesis, tumor progression, and metastasis. Consequently, these host cells may serve as a possible target in anti-tumor and anti-metastatic therapeutic strategies. Targeting the tumor associated host cells offers the benefit that such cells do not mutate and develop resistance in response to treatment, a major cause of failure in cancer therapeutics targeting neoplastic cells. This review discusses the role of host cells in the tumor microenvironment during tumorigenesis, progression, and metastasis, and provides an overview of recent developments in targeting these cell populations to enhance cancer therapy efficacy.

Circadian disruption induced by light-at-night accelerates aging and promotes tumorigenesis in rats

PubMed Central

Vinogradova, Irina A.; Anisimov, Vladimir N.; Bukalev, Andrey V.; Semenchenko, Anna V.; Zabezhinski, Mark A.

2009-01-01

We evaluated the effect of various light/dark regimens on the survival, life span and tumorigenesis in rats. Two hundred eight male and 203 females LIO rats were subdivided into 4 groups and kept at various light/dark regimens: standard 12:12 light/dark (LD); natural lighting of the North-West of Russia (NL); constant light (LL), and constant darkness (DD) since the age of 25 days until natural death. We found that exposure to NL and LL regimens accelerated development of metabolic syndrome and spontaneous tumorigenesis, shortened life span both in male and females rats as compared to the standard LD regimen. We conclude that circadian disruption induced by light-at-night accelerates aging and promotes tumorigenesis in rats. This observation supports the conclusion of the International Agency Research on Cancer that shift-work that involves circadian disruption is probably carcinogenic to humans. PMID:20157558

The effect of 6-methylthiohexyl isothiocyanate isolated from Wasabia japonica (wasabi) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-buatnone-induced lung tumorigenesis in mice.

PubMed

Yano, T; Yajima, S; Virgona, N; Yano, Y; Otani, S; Kumagai, H; Sakurai, H; Kishimoto, M; Ichikawa, T

2000-07-31

The present study was undertaken to estimate the effect of 6-methylthiohexyl isothiocyanate (6MHITC) isolated from Wasabia japonica (wasabi) pretreatment on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-induced lung tumorigenesis in mice. Pretreatment with 6MHITC for 4 consecutive days at a daily dose of 5 micromol significantly inhibited NNK-induced O(6)-methylguanine formation in lungs at 4 h after the injection. In conjugation with this inhibitory effect, 6MHITC suppressed the increase in proliferating nuclear cell antigen level as well as ornithine decarboxylase activity at a promotion stage of NNK-induced lung tumorigenesis. Finally, this treatment of 6MHITC suppressed the NNK-induced lung tumorigenesis in mice. These results suggest that 6MHITC inhibits the development of lung tumors in mice treated with NNK, due to the suppression of initiation stage.

Peroxisome proliferator-activated receptor gamma agonist troglitazone induces colon tumors in normal C57BL/6J mice and enhances colonic carcinogenesis in Apc1638 N/+ Mlh1+/- double mutant mice.

PubMed

Yang, Kan; Fan, Kun-Hua; Lamprecht, Sergio A; Edelmann, Winfried; Kopelovich, Levy; Kucherlapati, Raju; Lipkin, Martin

2005-09-10

The role of the nuclear peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in colon tumorigenesis remains controversial. Notwithstanding evidence that PPAR-gamma ligands impede murine colorectal carcinogenesis, PPAR-gamma agonists have been shown to enhance in vivo tumor formation in mouse models of human colon cancer. Our study was designed to determine whether troglitazone (TGZ) induces colonic tumor formation in normal C57BL/6J mice and enhances colorectal carcinogenesis in double mutant Apc1638N/+ Mlh1+/- mice fed a standard AIN-76A diet. We report herein that not only does TGZ enhance carcinogenesis in the large intestine of mutant mice predisposed to intestinal carcinogenesis but TGZ also induces colonic tumors in normal mice without gene targeting or carcinogen administration. This observation indicates that preexisting mutational events are not necessary for induction of colonic tumors by activated PPAR-gamma in vivo. (c) 2005 Wiley-Liss, Inc.

Hereditary mixed polyposis syndrome is caused by a 40-kb upstream duplication that leads to increased and ectopic expression of the BMP antagonist GREM1.

PubMed

Jaeger, Emma; Leedham, Simon; Lewis, Annabelle; Segditsas, Stefania; Becker, Martin; Cuadrado, Pedro Rodenas; Davis, Hayley; Kaur, Kulvinder; Heinimann, Karl; Howarth, Kimberley; East, James; Taylor, Jenny; Thomas, Huw; Tomlinson, Ian

2012-05-06

Hereditary mixed polyposis syndrome (HMPS) is characterized by apparent autosomal dominant inheritance of multiple types of colorectal polyp, with colorectal carcinoma occurring in a high proportion of affected individuals. Here, we use genetic mapping, copy-number analysis, exclusion of mutations by high-throughput sequencing, gene expression analysis and functional assays to show that HMPS is caused by a duplication spanning the 3' end of the SCG5 gene and a region upstream of the GREM1 locus. This unusual mutation is associated with increased allele-specific GREM1 expression. Whereas GREM1 is expressed in intestinal subepithelial myofibroblasts in controls, GREM1 is predominantly expressed in the epithelium of the large bowel in individuals with HMPS. The HMPS duplication contains predicted enhancer elements; some of these interact with the GREM1 promoter and can drive gene expression in vitro. Increased GREM1 expression is predicted to cause reduced bone morphogenetic protein (BMP) pathway activity, a mechanism that also underlies tumorigenesis in juvenile polyposis of the large bowel.

Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia

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

Alcaraz, Jordi; Xu, Ren; Mori, Hidetoshi

2008-10-20

In the mammary gland, epithelial cells are embedded in a 'soft' environment and become functionally differentiated in culture when exposed to a laminin-rich extracellular matrix gel. Here, we define the processes by which mammary epithelial cells integrate biochemical and mechanical extracellular cues to maintain their differentiated phenotype. We used single cells cultured on top of gels in conditions permissive for {beta}-casein expression using atomic force microscopy to measure the elasticity of the cells and their underlying substrata. We found that maintenance of {beta}-casein expression required both laminin signalling and a 'soft' extracellular matrix, as is the case in normal tissuesmore » in vivo, and biomimetic intracellular elasticity, as is the case in primary mammary epithelial organoids. Conversely, two hallmarks of breast cancer development, stiffening of the extracellular matrix and loss of laminin signalling, led to the loss of {beta}-casein expression and non-biomimetic intracellular elasticity. Our data indicate that tissue-specific gene expression is controlled by both the tissues unique biochemical milieu and mechanical properties, processes involved in maintenance of tissue integrity and protection against tumorigenesis.« less

The histone code reader SPIN1 controls RET signaling in liposarcoma

PubMed Central

Franz, Henriette; Greschik, Holger; Willmann, Dominica; Ozretić, Luka; Jilg, Cordula Annette; Wardelmann, Eva; Jung, Manfred; Buettner, Reinhard; Schüle, Roland

2015-01-01

The histone code reader Spindlin1 (SPIN1) has been implicated in tumorigenesis and tumor growth, but the underlying molecular mechanisms remain poorly understood. Here, we show that reducing SPIN1 levels strongly impairs proliferation and increases apoptosis of liposarcoma cells in vitro and in xenograft mouse models. Combining signaling pathway, genome-wide chromatin binding, and transcriptome analyses, we found that SPIN1 directly enhances expression of GDNF, an activator of the RET signaling pathway, in cooperation with the transcription factor MAZ. Accordingly, knockdown of SPIN1 or MAZ results in reduced levels of GDNF and activated RET explaining diminished liposarcoma cell proliferation and survival. In line with these observations, levels of SPIN1, GDNF, activated RET, and MAZ are increased in human liposarcoma compared to normal adipose tissue or lipoma. Importantly, a mutation of SPIN1 within the reader domain interfering with chromatin binding reduces liposarcoma cell proliferation and survival. Together, our data describe a molecular mechanism for SPIN1 function in liposarcoma and suggest that targeting SPIN1 chromatin association with small molecule inhibitors may represent a novel therapeutic strategy. PMID:25749382

Network Modeling of microRNA-mRNA Interactions in Neuroblastoma Tumorigenesis Identifies miR-204 as a Direct Inhibitor of MYCN.

PubMed

Ooi, Chi Yan; Carter, Daniel R; Liu, Bing; Mayoh, Chelsea; Beckers, Anneleen; Lalwani, Amit; Nagy, Zsuzsanna; De Brouwer, Sara; Decaesteker, Bieke; Hung, Tzong-Tyng; Norris, Murray D; Haber, Michelle; Liu, Tao; De Preter, Katleen; Speleman, Frank; Cheung, Belamy B; Marshall, Glenn M

2018-06-15

Neuroblastoma is a pediatric cancer of the sympathetic nervous system where MYCN amplification is a key indicator of poor prognosis. However, mechanisms by which MYCN promotes neuroblastoma tumorigenesis are not fully understood. In this study, we analyzed global miRNA and mRNA expression profiles of tissues at different stages of tumorigenesis from TH-MYCN transgenic mice, a model of MYCN-driven neuroblastoma. On the basis of a Bayesian learning network model in which we compared pretumor ganglia from TH-MYCN +/+ mice to age-matched wild-type controls, we devised a predicted miRNA-mRNA interaction network. Among the miRNA-mRNA interactions operating during human neuroblastoma tumorigenesis, we identified miR-204 as a tumor suppressor miRNA that inhibited a subnetwork of oncogenes strongly associated with MYCN -amplified neuroblastoma and poor patient outcome. MYCN bound to the miR-204 promoter and repressed miR-204 transcription. Conversely, miR-204 directly bound MYCN mRNA and repressed MYCN expression. miR-204 overexpression significantly inhibited neuroblastoma cell proliferation in vitro and tumorigenesis in vivo Together, these findings identify novel tumorigenic miRNA gene networks and miR-204 as a tumor suppressor that regulates MYCN expression in neuroblastoma tumorigenesis. Significance: Network modeling of miRNA-mRNA regulatory interactions in a mouse model of neuroblastoma identifies miR-204 as a tumor suppressor and negative regulator of MYCN. Cancer Res; 78(12); 3122-34. ©2018 AACR . ©2018 American Association for Cancer Research.

Computational modeling identifies key gene regulatory interactions underlying phenobarbital-mediated tumor promotion

PubMed Central

Luisier, Raphaëlle; Unterberger, Elif B.; Goodman, Jay I.; Schwarz, Michael; Moggs, Jonathan; Terranova, Rémi; van Nimwegen, Erik

2014-01-01

Gene regulatory interactions underlying the early stages of non-genotoxic carcinogenesis are poorly understood. Here, we have identified key candidate regulators of phenobarbital (PB)-mediated mouse liver tumorigenesis, a well-characterized model of non-genotoxic carcinogenesis, by applying a new computational modeling approach to a comprehensive collection of in vivo gene expression studies. We have combined our previously developed motif activity response analysis (MARA), which models gene expression patterns in terms of computationally predicted transcription factor binding sites with singular value decomposition (SVD) of the inferred motif activities, to disentangle the roles that different transcriptional regulators play in specific biological pathways of tumor promotion. Furthermore, transgenic mouse models enabled us to identify which of these regulatory activities was downstream of constitutive androstane receptor and β-catenin signaling, both crucial components of PB-mediated liver tumorigenesis. We propose novel roles for E2F and ZFP161 in PB-mediated hepatocyte proliferation and suggest that PB-mediated suppression of ESR1 activity contributes to the development of a tumor-prone environment. Our study shows that combining MARA with SVD allows for automated identification of independent transcription regulatory programs within a complex in vivo tissue environment and provides novel mechanistic insights into PB-mediated hepatocarcinogenesis. PMID:24464994

Aberrantly regulated dysadherin and B-cell lymphoma 2/B-cell lymphoma 2-associated X enhances tumorigenesis and DNA targeting drug resistance of liver cancer stem cells

PubMed Central

JIANG, NAN; CHEN, WEI; ZHANG, JIAN-WEN; LI, YANG; ZENG, XIAN-CHENG; ZHANG, TONG; FU, BIN-SHENG; YI, HUI-MIN; ZHANG, QI

2015-01-01

Cancer stem cells (CSCs) in hepatocellular carcinoma (HCC) are frequently resistant to current therapeutic regimens and therefore responsible for tumor recurrence. Previous studies have reported that expression levels of dysadherin in CSCs may be used as a prognostic indicator, which is also responsible for treatment failure and poor survival rates. The present study analyzed the association of enhanced dysadherin levels with drug resistance and evasion of apoptosis in human HCC SP cells. An SP of 3.7% was isolated from human HCC cells using fluorescence-activated cell sorting. These SP cells displayed elevated levels of dysadherin and stemness proteins as well as high resistance to chemotherapeutic drugs and apoptosis. In order to reveal the possible link between dysadherin levels and tumorigenesis of SP cells, small interfering RNA technology was used to knockdown the expression of dysadherin in SP cells. Of note, the siRNA-transfected SP cells showed significantly reduced levels of stemness proteins, and were more sensitive to DNA-targeting drugs and apoptotic cell death as compared to non-transfected cells. Furthermore, in vivo experiments in NON/SCID mice indicated that dysadherin-expressing SP cells were highly tumorigenic, as they were able to induce tumor growth. The SP cell-derived tumor tissues in turn showed elevated dysadherin levels. The results of the present study therefore suggested that knockdown of dysadherin suppressed the tumorigenic properties of cancer stem-like SP cells. Hence, dysadherin is a valuable potential target for the development of novel anti-cancer drugs. PMID:26458963

Synergistic action of Smad4 and Pten in suppressing pancreatic ductal adenocarcinoma formation in mice.

PubMed

Xu, X; Ehdaie, B; Ohara, N; Yoshino, T; Deng, C-X

2010-02-04

Mutations of SMAD4/DPC4 are found in about 60% of human invasive pancreatic ductal adenocarcinomas (PDACs); yet, the manner in which SMAD4 deficiency enhances tumorigenesis remains elusive. Using a Cre-LoxP approach, we generated a mutant mouse carrying a targeted deletion of Smad4 in the pancreas. We showed that the absence of Smad4 alone did not trigger pancreas tumor formation; however, it increased the expression of an inactivated form of Pten, suggesting a role of Pten in preventing Smad4-/- cells from undergoing malignancy. To investigate this, we disrupted both Pten and Smad4. We showed that Pten deficiency initiated widespread premalignant lesions, and a low tumor incidence that was significantly accelerated by Smad4-deficiency. The absence of Smad4 in a Pten-mutant background enhanced cell proliferation and triggered transdifferentiation from acinar, centroacinar and islet cells, accompanied by activation of Notch1 signaling. We showed that all tumors developed in the Smad4/Pten-mutant pancreas exhibited high levels of pAKT and mTOR, and that about 50 and 83% of human pancreatic cancers examined showed increased pAKT and pmTOR, respectively. Besides the similarity in gene expression, the pAKT and/or pmTOR-positive human PDACs and mouse pancreatic tumors also shared some histopathological similarities. These observations indicate that Smad4/Pten-mutant mice mimic the tumor progression of human pancreatic cancers that are driven by activation of the AKT-mTOR pathway, and uncovered a synergistic action of Smad4 and Pten in repressing pancreatic tumorigenesis.

RSPO3 expands intestinal stem cell and niche compartments and drives tumorigenesis.

PubMed

Hilkens, John; Timmer, Nikki C; Boer, Mandy; Ikink, Gerjon J; Schewe, Matthias; Sacchetti, Andrea; Koppens, Martijn A J; Song, Ji-Ying; Bakker, Elvira R M

2017-06-01

The gross majority of colorectal cancer cases results from aberrant Wnt/β-catenin signalling through adenomatous polyposis coli ( APC) or CTNNB1 mutations. However, a subset of human colon tumours harbour, mutually exclusive with APC and CTNNB1 mutations, gene fusions in RSPO2 or RSPO3, leading to enhanced expression of these R-spondin genes. This suggested that RSPO activation can substitute for the most common mutations as an alternative driver for intestinal cancer. Involvement of RSPO3 in tumour growth was recently shown in RSPO3 -fusion-positive xenograft models. The current study determines the extent into which solely a gain in RSPO3 actually functions as a driver of intestinal cancer in a direct, causal fashion, and addresses the in vivo activities of RSPO3 in parallel. We generated a conditional Rspo3 transgenic mouse model in which the Rspo3 transgene is expressed upon Cre activity. Cre is provided by cross-breeding with Lgr5 -GFP-Cre ERT2 mice. Upon in vivo Rspo3 expression, mice rapidly developed extensive hyperplastic, adenomatous and adenocarcinomatous lesions throughout the intestine. RSPO3 induced the expansion of Lgr5 + stem cells, Paneth cells, non-Paneth cell label-retaining cells and Lgr4 + cells, thus promoting both intestinal stem cell and niche compartments. Wnt/β-catenin signalling was modestly increased upon Rspo3 expression and mutant Kras synergised with Rspo3 in hyperplastic growth. We provide in vivo evidence that RSPO3 stimulates the crypt stem cell and niche compartments and drives rapid intestinal tumorigenesis. This establishes RSPO3 as a potent driver of intestinal cancer and proposes RSPO3 as a candidate target for therapy in patients with colorectal cancer harbouring RSPO3 fusions. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Dual catenin loss in murine liver causes tight junctional deregulation and progressive intrahepatic cholestasis.

PubMed

Pradhan-Sundd, Tirthadipa; Zhou, Lili; Vats, Ravi; Jiang, An; Molina, Laura; Singh, Sucha; Poddar, Minakshi; Russell, Jacquelyn; Stolz, Donna B; Oertel, Michael; Apte, Udayan; Watkins, Simon; Ranganathan, Sarangarajan; Nejak-Bowen, Kari N; Sundd, Prithu; Monga, Satdarshan Pal

2018-06-01

β-Catenin, the downstream effector of the Wnt signaling, plays important roles in hepatic development, regeneration, and tumorigenesis. However, its role at hepatocyte adherens junctions (AJ) is relatively poorly understood, chiefly due to spontaneous compensation by γ-catenin. We simultaneously ablated β- and γ-catenin expression in mouse liver by interbreeding β-catenin-γ-catenin double-floxed mice and Alb-Cre transgenic mice. Double knockout mice show failure to thrive, impaired hepatocyte differentiation, cholemia, ductular reaction, progressive cholestasis, inflammation, fibrosis, and tumorigenesis, which was associated with deregulation of tight junctions (TJ) and bile acid transporters, leading to early morbidity and mortality, a phenotype reminiscent of progressive familial intrahepatic cholestasis (PFIC). To address the mechanism, we specifically and temporally eliminated both catenins from hepatocytes using adeno-associated virus 8 carrying Cre-recombinase under the thyroid-binding globulin promoter (AAV8-TBG-Cre). This led to a time-dependent breach of the blood-biliary barrier associated with sequential disruption of AJ and TJ verified by ultrastructural imaging and intravital microscopy, which revealed unique paracellular leaks around individual hepatocytes, allowing mixing of blood and bile and leakage of blood from one sinusoid to another. Molecular analysis identified sequential losses of E-cadherin, occludin, claudin-3, and claudin-5 due to enhanced proteasomal degradation, and of claudin-2, a β-catenin transcriptional target, which was also validated in vitro. We report partially redundant function of catenins at AJ in regulating TJ and contributing to the blood-biliary barrier. Furthermore, concomitant hepatic loss of β- and γ-catenin disrupts structural and functional integrity of AJ and TJ via transcriptional and posttranslational mechanisms. Mice with dual catenin loss develop progressive intrahepatic cholestasis, providing a unique model to study diseases such as PFIC. (Hepatology 2018;67:2320-2337). © 2017 by the American Association for the Study of Liver Diseases.

Role of PP2Cα in cell growth, in radio- and chemosensitivity, and in tumorigenicity

PubMed Central

Lammers, Twan; Peschke, Peter; Ehemann, Volker; Debus, Jürgen; Slobodin, Boris; Lavi, Sara; Huber, Peter

2007-01-01

Background PP2Cα is the representative member of the type 2C family of protein phosphatases, and it has recently been implicated in the regulation of p53-, TGFβ-, cyclin-dependent kinase- and apoptosis-signaling. To investigate the role of PP2Cα in cell growth and in radio- and chemosensitivity, wild type and PP2Cα siRNA-expressing MCF7 cells were subjected to several different viability and cell cycle analyses, both under basal conditions and upon treatment with radio- and chemotherapy. By comparing the growth of tumors established from both types of cells, we also evaluated the involvement of PP2Cα in tumorigenesis. Results It was found that knockdown of PP2Cα did not affect the proliferation, the clonogenic survival and the membrane integrity of MCF7 cells. In addition, it did not alter their radio- and chemosensitivity. For PP2Cα siRNA-expressing MCF7 cells, the number of cells in the G0/G1 phase of the cell cycle was reduced, the induction of the G1 block was attenuated, the number of cells in G2/M was increased, and the induction of the G2 block was enhanced. The tumorigenic potential of PP2Cα siRNA-expressing MCF7 cells was found to be higher than that of wild type MCF7 cells, and the in vivo proliferation of these cells was found to be increased. Conclusion Based on these findings, we conclude that PP2Cα is not involved in controlling cell growth and radio- and chemosensitivity in vitro. It does, however, play a role in the regulation of the cell cycle, in the induction of cell cycle checkpoints and in tumorigenesis. The latter notion implies that PP2Cα may possess tumor-suppressing properties, and it thereby sets the stage for more elaborate analyses on its involvement in the development and progression of cancer. PMID:17941990

Downregulated long non-coding RNA MEG3 in breast cancer regulates proliferation, migration and invasion by depending on p53’s transcriptional activity

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

Sun, Lin; Li, Yu; Yang, Bangxiang, E-mail: b19933009@qq.coom

Long non-coding RNAs (lncRNAs) was found to play critical roles in tumorigenesis, hence, screen of tumor-related lncRNAs, identification of their biological roles is important for understanding the processes of tumorigenesis. In this study, we identified the expressing difference of several tumor-related lncRNAs in breast cancer samples and found that, MEG3, which is downregulated in non-small cell lung cancer (NSCLC) tumor tissues, is also downregulated in breast cancer samples compared with adjacent tissues. For figuring out the effect of MEG3 in breast cancer cells MCF7 and MB231, we overexpressed MEG3 in these cells, and found that it resulted the inhibition ofmore » proliferation, colony formation, migration and invasion capacities by enhancing p53’s transcriptional activity on its target genes, including p21, Maspin and KAI1. MEG3 presented similar effects in MB157, which is a p53-null breast cancer cell line, when functional p53 but not p53R273H mutant, which lacks transcriptional activity, was introduced. Surprisingly, overexpression of MEG3 activates p53’s transcriptional activity by decreasing MDM2’s transcription level, and thus stabilizes and accumulates P53. Taken together, our findings indicate that MEG3 is downregulated in breast cancer tissues and affects breast cancer cells’ malignant behaviors, which indicate MEG3 a potential therapeutic target for breast cancer. - Highlights: • MEG3 RNA is widely downregulated in breast tumor tissue. • MEG3 regulates P53 indirectly through transcriptional regulation of MDM2. • Under unstressed condition, MEG3-related P53 accumulation transcriptionally activates p53’s target genes. • MEG3 expression level tightly regulates proliferation, colony formation, migration and invasion in breast tumor cells.« less

Leptin-mediated regulation of MT1-MMP localization is KIF1B dependent and enhances gastric cancer cell invasion.

PubMed

Dong, Zhaogang; Xu, Xiaofei; Du, Lutao; Yang, Yongmei; Cheng, Huanhuan; Zhang, Xin; Li, Zewu; Wang, Lili; Li, Juan; Liu, Hui; Qu, Xun; Wang, Chuanxin

2013-05-01

Leptin overexpression is closely correlated with gastric cancer (GC) invasion, but its exact effect and the underlying mechanism in tumorigenesis remain poorly understood. Membrane type 1-matrix metalloproteinase (MT1-MMP), a surface-anchored 'master switch' proteinase, is overexpressed and plays crucial roles in tumor invasion. Here, we characterized the influence of leptin on the generation and surface localization of MT1-MMP in GC and elucidated its molecular mechanisms. Our results revealed that leptin promoted GC cell invasion in vitro by upregulating MT1-MMP expression. Furthermore, cell surface biotinylation assay and flow cytometry demonstrated that the surface expression of MT1-MMP was also enhanced by leptin, and knockdown of kinesin family member 1B (KIF1B, a microtubule plus end-directed monomeric motor protein) by small interference RNA inhibited this process. Notably, coimmunoprecipitation analysis indicated that leptin enhanced the interaction of MT1-MMP with KIF1B in a time-dependent manner, which consequently contributed to GC cell invasion. Moreover, leptin increased MT1-MMP or KIF1B expression by the protein kinase B (AKT) pathway and extracellular signal-regulated kinase 1/2 partially participated in this process. However, only AKT was implicated in the leptin-mediated membrane localization of MT1-MMP. Immunohistochemistry analysis revealed that leptin, MT1-MMP and KIF1B are overexpressed in GC tissues, and they positively correlated with clinical stage and lymph node metastasis. These observations indicate that this regulatory network exists in vivo. Taken together, our findings suggest that leptin is an effective intracellular stimulator of MT1-MMP and that leptin-enhanced cell surface localization of MT1-MMP is dependent on KIF1B, which consequently plays a critical role in GC invasion.

Panx3 links body mass index and tumorigenesis in a genetically heterogeneous mouse model of carcinogen-induced cancer. | Office of Cancer Genomics

Cancer.gov

Body mass index (BMI) has been implicated as a primary factor influencing cancer development. However, understanding the relationship between these two complex traits has been confounded by both environmental and genetic heterogeneity. Analysis of QTL linked to tumorigenesis and BMI identified several loci associated with both phenotypes. Exploring these loci in greater detail revealed a novel relationship between the Pannexin 3 gene (Panx3) and both BMI and tumorigenesis. Panx3 is positively associated with BMI and is strongly tied to a lipid metabolism gene expression network.

The Hippo signaling pathway in liver regeneration and tumorigenesis.

PubMed

Hong, Lixin; Cai, Yabo; Jiang, Mingting; Zhou, Dawang; Chen, Lanfen

2015-01-01

The Hippo signaling pathway is an evolutionarily conserved signaling module that plays critical roles in liver size control and tumorigenesis. The Hippo pathway consists of a core kinase cascade in which the mammalian Ste20-like kinases (Mst1/2, orthologs of Drosophila Hippo) and their cofactor Salvador (Sav1) form a complex to phosphorylate and activate the large tumor suppressor (Lats1/2). Lats1/2 kinases in turn phosphorylate and inhibit the transcription co-activators, the Yes-associated protein (YAP) and the transcriptional co-activator with PDZ-binding motif (TAZ), two major downstream effectors of the Hippo pathway. Losses of the Hippo pathway components induce aberrant hepatomegaly and tumorigenesis, in which YAP coordinates regulation of cell proliferation and apoptosis and plays an essential role. This review summarizes the current findings of the regulation of Hippo signaling in liver regeneration and tumorigenesis, focusing on how the loss of tumor suppressor components of the Hippo pathway results in liver cancers and discussing the molecular mechanisms that regulate the expression and activation of its downstream effector YAP in liver tumorigenesis. © The Author 2014. Published by ABBS Editorial Office in association with Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences.

Naringin, a natural dietary compound, prevents intestinal tumorigenesis in Apc (Min/+) mouse model.

PubMed

Zhang, Yu-Sheng; Li, Ye; Wang, Yan; Sun, Shi-Yue; Jiang, Tao; Li, Cong; Cui, Shu-Xiang; Qu, Xian-Jun

2016-05-01

Naringin is a natural dietary flavonoid compound. We aimed to evaluate the effects of naringin on intestinal tumorigenesis in the adenomatous polyposis coli multiple intestinal neoplasia (Apc (Min/+)) mouse model. Apc (Min/+) mice were given either naringin (150 mg/kg) or vehicle by p.o. gavage daily for 12 consecutive weeks. Mice were killed with ether, and blood samples were collected to assess the concentrations of IL-6 and PGE2. Total intestines were removed, and the number of polyps was examined. Tissue samples of intestinal polyps were subjected to the assays of histopathology, immunohistochemical analysis and Western blotting analysis. Apc (Min/+) mice fed with naringin developed less and smaller polyps in total intestines. Naringin prevented intestinal tumorigenesis without adverse effects. Histopathologic analysis revealed the reduction of dysplastic cells and dysplasia in the adenomatous polyps. The treatments' effects might arise from its anti-proliferation, induction of apoptosis and modulation of GSK-3β and APC/β-catenin signaling pathways. Naringin also exerted its effects on tumorigenesis through anti-chronic inflammation. Naringin prevented intestinal tumorigenesis likely through a collection of activities including anti-proliferation, induction of apoptosis, modulation of GSK-3β and APC/β-catenin pathways and anti-inflammation. Naringin is a potential chemopreventive agent for reducing the risk of colonic cancers.

Fbxw7 Deletion Accelerates KrasG12D-Driven Pancreatic Tumorigenesis via Yap Accumulation.

PubMed

Zhang, Qiang; Zhang, Yaqing; Parsels, Joshua D; Lohse, Ines; Lawrence, Theodore S; Pasca di Magliano, Marina; Sun, Yi; Morgan, Meredith A

2016-11-01

Pancreatic cancers driven by KRAS mutations require additional mutations for tumor progression. The tumor suppressor FBXW7 is altered in pancreatic cancers, but its contribution to pancreatic tumorigenesis is unknown. To determine potential cooperation between Kras mutation and Fbxw7 inactivation in pancreatic tumorigenesis, we generated P48-Cre;LSL-Kras G12D ;Fbxw7 fl/fl (KFC fl/fl ) compound mice. We found that KFC fl/fl mice displayed accelerated tumorigenesis: all mice succumbed to pancreatic ductal adenocarcinoma (PDA) by 40 days of age, with PDA onset occurring by 2 weeks of age. PDA in KFC fl/fl mice was preceded by earlier onset of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN) lesions, and associated with chromosomal instability and the accumulation of Fbxw7 substrates Yes-associated protein (Yap), c-Myc, and Notch. Using KFC fl/fl and FBXW7-deficient human pancreatic cancer cells, we found that Yap silencing attenuated growth promotion by Fbxw7 deletion. Our data demonstrate that Fbxw7 is a potent suppressor of Kras G12D -induced pancreatic tumorigenesis due, at least in part, to negative regulation of Yap. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Suppression of intestinal tumorigenesis in Apc mutant mice upon Musashi-1 deletion.

PubMed

Wolfe, Andy R; Ernlund, Amanda; McGuinness, William; Lehmann, Carl; Carl, Kaitlyn; Balmaceda, Nicole; Neufeld, Kristi L

2017-02-15

Therapeutic strategies based on a specific oncogenic target are better justified when elimination of that particular oncogene reduces tumorigenesis in a model organism. One such oncogene, Musashi-1 ( Msi-1 ), regulates translation of target mRNAs and is implicated in promoting tumorigenesis in the colon and other tissues. Msi-1 targets include the tumor suppressor adenomatous polyposis coli ( Apc ), a Wnt pathway antagonist lost in ∼80% of all colorectal cancers. Cell culture experiments have established that Msi-1 is a Wnt target, thus positioning Msi-1 and Apc as mutual antagonists in a mutually repressive feedback loop. Here, we report that intestines from mice lacking Msi-1 display aberrant Apc and Msi-1 mutually repressive feedback, reduced Wnt and Notch signaling, decreased proliferation, and changes in stem cell populations, features predicted to suppress tumorigenesis. Indeed, mice with germline Apc mutations ( Apc Min ) or with the Apc 1322T truncation mutation have a dramatic reduction in intestinal polyp number when Msi-1 is deleted. Taken together, these results provide genetic evidence that Msi-1 contributes to intestinal tumorigenesis driven by Apc loss, and validate the pursuit of Msi-1 inhibitors as chemo-prevention agents to reduce tumor burden. © 2017. Published by The Company of Biologists Ltd.

The tumorigenic FGFR3-TACC3 gene fusion escapes miR-99a regulation in glioblastoma

PubMed Central

Parker, Brittany C.; Annala, Matti J.; Cogdell, David E.; Granberg, Kirsi J.; Sun, Yan; Ji, Ping; Li, Xia; Gumin, Joy; Zheng, Hong; Hu, Limei; Yli-Harja, Olli; Haapasalo, Hannu; Visakorpi, Tapio; Liu, Xiuping; Liu, Chang-gong; Sawaya, Raymond; Fuller, Gregory N.; Chen, Kexin; Lang, Frederick F.; Nykter, Matti; Zhang, Wei

2013-01-01

Fusion genes are chromosomal aberrations that are found in many cancers and can be used as prognostic markers and drug targets in clinical practice. Fusions can lead to production of oncogenic fusion proteins or to enhanced expression of oncogenes. Several recent studies have reported that some fusion genes can escape microRNA regulation via 3′–untranslated region (3′-UTR) deletion. We performed whole transcriptome sequencing to identify fusion genes in glioma and discovered FGFR3-TACC3 fusions in 4 of 48 glioblastoma samples from patients both of mixed European and of Asian descent, but not in any of 43 low-grade glioma samples tested. The fusion, caused by tandem duplication on 4p16.3, led to the loss of the 3′-UTR of FGFR3, blocking gene regulation of miR-99a and enhancing expression of the fusion gene. The fusion gene was mutually exclusive with EGFR, PDGFR, or MET amplification. Using cultured glioblastoma cells and a mouse xenograft model, we found that fusion protein expression promoted cell proliferation and tumor progression, while WT FGFR3 protein was not tumorigenic, even under forced overexpression. These results demonstrated that the FGFR3-TACC3 gene fusion is expressed in human cancer and generates an oncogenic protein that promotes tumorigenesis in glioblastoma. PMID:23298836

Inflammation-Dependent IL18 Signaling Restricts Hepatocellular Carcinoma Growth by Enhancing the Accumulation and Activity of Tumor-Infiltrating Lymphocytes.

PubMed

Markowitz, Geoffrey J; Yang, Pengyuan; Fu, Jing; Michelotti, Gregory A; Chen, Rui; Sui, Jianhua; Yang, Bin; Qin, Wen-Hao; Zhang, Zheng; Wang, Fu-Sheng; Diehl, Anna Mae; Li, Qi-Jing; Wang, Hongyang; Wang, Xiao-Fan

2016-04-15

Chronic inflammation in liver tissue is an underlying cause of hepatocellular carcinoma. High levels of inflammatory cytokine IL18 in the circulation of patients with hepatocellular carcinoma correlates with poor prognosis. However, conflicting results have been reported for IL18 in hepatocellular carcinoma development and progression. In this study, we used tissue specimens from hepatocellular carcinoma patients and clinically relevant mouse models of hepatocellular carcinoma to evaluate IL18 expression and function. In a mouse model of liver fibrosis that recapitulates a tumor-promoting microenvironment, global deletion of the IL18 receptor IL18R1 enhanced tumor growth and burden. Similarly, in a carcinogen-induced model of liver tumorigenesis, IL18R1 deletion increased tumor burden. Mechanistically, we found that IL18 exerted inflammation-dependent tumor-suppressive effects largely by promoting the differentiation, activity, and survival of tumor-infiltrating T cells. Finally, differences in the expression of IL18 in tumor tissue versus nontumor tissue were more predictive of patient outcome than overall tissue expression. Taken together, our findings resolve a long-standing contradiction regarding a tumor-suppressive role for IL18 in established hepatocellular carcinoma and provide a mechanistic explanation for the complex relationship between its expression pattern and hepatocellular carcinoma prognosis. Cancer Res; 76(8); 2394-405. ©2016 AACR. ©2016 American Association for Cancer Research.

The synergistic effect of chemical carcinogens enhances Epstein-Barr virus reactivation and tumor progression of nasopharyngeal carcinoma cells.

PubMed

Fang, Chih-Yeu; Huang, Sheng-Yen; Wu, Chung-Chun; Hsu, Hui-Yu; Chou, Sheng-Ping; Tsai, Ching-Hwa; Chang, Yao; Takada, Kenzo; Chen, Jen-Yang

2012-01-01

Seroepidemiological studies imply a correlation between Epstein-Barr virus (EBV) reactivation and the development of nasopharyngeal carcinoma (NPC). N-nitroso compounds, phorbols, and butyrates are chemicals found in food and herb samples collected from NPC high-risk areas. These chemicals have been reported to be risk factors contributing to the development of NPC, however, the underlying mechanism is not fully understood. We have demonstrated previously that low dose N-methyl-N'-nitro-N-nitrosoguanidine (MNNG, 0.1 µg/ml) had a synergistic effect with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate (SB) in enhancing EBV reactivation and genome instability in NPC cells harboring EBV. Considering that residents in NPC high-risk areas may contact regularly with these chemical carcinogens, it is vital to elucidate the relation between chemicals and EBV and their contributions to the carcinogenesis of NPC. In this study, we constructed a cell culture model to show that genome instability, alterations of cancer hallmark gene expression, and tumorigenicity were increased after recurrent EBV reactivation in NPC cells following combined treatment of TPA/SB and MNNG. NPC cells latently infected with EBV, NA, and the corresponding EBV-negative cell, NPC-TW01, were periodically treated with MNNG, TPA/SB, or TPA/SB combined with MNNG. With chemically-induced recurrent reactivation of EBV, the degree of genome instability was significantly enhanced in NA cells treated with a combination of TPA/SB and MNNG than those treated individually. The Matrigel invasiveness, as well as the tumorigenicity in mouse, was also enhanced in NA cells after recurrent EBV reactivation. Expression profile analysis by microarray indicates that many carcinogenesis-related genes were altered after recurrent EBV reactivation, and several aberrations observed in cell lines correspond to alterations in NPC lesions. These results indicate that cooperation between chemical carcinogens can enhance the reactivation of EBV and, over recurrent reactivations, lead to alteration of cancer hallmark gene expression with resultant enhancement of tumorigenesis in NPC.

The Synergistic Effect of Chemical Carcinogens Enhances Epstein-Barr Virus Reactivation and Tumor Progression of Nasopharyngeal Carcinoma Cells

PubMed Central

Fang, Chih-Yeu; Huang, Sheng-Yen; Wu, Chung-Chun; Hsu, Hui-Yu; Chou, Sheng-Ping; Tsai, Ching-Hwa; Chang, Yao; Takada, Kenzo; Chen, Jen-Yang

2012-01-01

Seroepidemiological studies imply a correlation between Epstein-Barr virus (EBV) reactivation and the development of nasopharyngeal carcinoma (NPC). N-nitroso compounds, phorbols, and butyrates are chemicals found in food and herb samples collected from NPC high-risk areas. These chemicals have been reported to be risk factors contributing to the development of NPC, however, the underlying mechanism is not fully understood. We have demonstrated previously that low dose N-methyl-N’-nitro-N-nitrosoguanidine (MNNG, 0.1 µg/ml) had a synergistic effect with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate (SB) in enhancing EBV reactivation and genome instability in NPC cells harboring EBV. Considering that residents in NPC high-risk areas may contact regularly with these chemical carcinogens, it is vital to elucidate the relation between chemicals and EBV and their contributions to the carcinogenesis of NPC. In this study, we constructed a cell culture model to show that genome instability, alterations of cancer hallmark gene expression, and tumorigenicity were increased after recurrent EBV reactivation in NPC cells following combined treatment of TPA/SB and MNNG. NPC cells latently infected with EBV, NA, and the corresponding EBV-negative cell, NPC-TW01, were periodically treated with MNNG, TPA/SB, or TPA/SB combined with MNNG. With chemically-induced recurrent reactivation of EBV, the degree of genome instability was significantly enhanced in NA cells treated with a combination of TPA/SB and MNNG than those treated individually. The Matrigel invasiveness, as well as the tumorigenicity in mouse, was also enhanced in NA cells after recurrent EBV reactivation. Expression profile analysis by microarray indicates that many carcinogenesis-related genes were altered after recurrent EBV reactivation, and several aberrations observed in cell lines correspond to alterations in NPC lesions. These results indicate that cooperation between chemical carcinogens can enhance the reactivation of EBV and, over recurrent reactivations, lead to alteration of cancer hallmark gene expression with resultant enhancement of tumorigenesis in NPC. PMID:23024765

Unraveling the Molecular Mechanism(s) Underlying Er+/PR-Breast Tumorigenesis Using a Novel Genetically Engineered Mouse Model

DTIC Science & Technology

2011-11-01

FOR: U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION STATEMENT...those of the author(s) and should not be construed as an official Department of the Army position, policy or decision unless so designated by other...NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) U.S. Army Medical Research

Corruption of homeostatic mechanisms in the guanylyl cyclase C signaling pathway underlying colorectal tumorigenesis

PubMed Central

Waldman, Scott A

2010-01-01

Colon cancer, the second leading cause of cancer-related mortality worldwide, originates from the malignant transformation of intestinal epithelial cells. The intestinal epithelium undergoes a highly organized process of rapid regeneration along the crypt-villus axis, characterized by proliferation, migration, differentiation and apoptosis, whose coordination is essential to maintaining the mucosal barrier. Disruption of these homeostatic processes predisposes cells to mutations in tumor suppressors or oncogenes, whose dysfunction provides transformed cells an evolutionary growth advantage. While sequences of genetic mutations at different stages along the neoplastic continuum have been established, little is known of the events initiating tumorigenesis prior to adenomatous polyposis coli (APC) mutations. Here, we examine a role for the corruption of homeostasis induced by silencing novel tumor suppressors, including the intestine-specific transcription factor CDX2 and its gene target guanylyl cyclase C (GCC), as early events predisposing cells to mutations in APC and other sequential genes that initiate colorectal cancer. CDX2 and GCC maintain homeostatic regeneration in the intestine by restricting cell proliferation, promoting cell maturation and adhesion, regulating cell migration and defending the intestinal barrier and genomic integrity. Elimination of CDX2 or GCC promotes intestinal tumor initiation and growth in aged mice, mice carrying APC mutations or mice exposed to carcinogens. The roles of CDX2 and GCC in suppressing intestinal tumorigenesis, universal disruption in their signaling through silencing of hormones driving GCC, and the uniform overexpression of GCC by tumors underscore the potential value of oral replacement with GCC ligands as targeted prevention and therapy for colorectal cancer. PMID:20592492

Human cancer xenografts in outbred nude mice can be confounded by polymorphisms in a modifier of tumorigenesis.

PubMed

Zeineldin, Maged; Jensen, Derek; Paranjape, Smita R; Parelkar, Nikhil K; Jokar, Iman; Vielhauer, George A; Neufeld, Kristi L

2014-08-01

Tumorigenicity studies often employ outbred nude mice, in the absence of direct evidence that this mixed genetic background will negatively affect experimental outcome. Here we show that outbred nude mice carry two different alleles of Pla2g2a, a genetic modifier of intestinal tumorigenesis in mice. Here, we identify previous unreported linked polymorphisms in the promoter, noncoding and coding sequences of Pla2g2a and show that outbred nude mice from different commercial providers are heterogeneous for this polymorphic Pla2g2a allele. This heterogeneity even extends to mice obtained from a single commercial provider, which display mixed Pla2g2a genotypes. Notably, we demonstrated that the polymorphic Pla2g2a allele affects orthotopic xenograft establishment of human colon cancer cells in outbred nude mice. This finding establishes a non-cell-autonomous role for Pla2g2a in suppressing intestinal tumorigenesis. Using in vitro reporter assays and pharmacological inhibitors, we show promoter polymorphisms and nonsense-mediated RNA decay (NMD) as underlying mechanisms that lead to low Pla2g2a mRNA levels in tumor-sensitive mice. Together, this study provides mechanistic insight regarding Pla2g2a polymorphisms and demonstrates a non-cell-autonomous role for Pla2g2a in suppressing tumors. Moreover, our direct demonstration that mixed genetic backgrounds of outbred nude mice can significantly affect baseline tumorigenicity cautions against future use of outbred mice for tumor xenograft studies. Copyright © 2014 by the Genetics Society of America.

Human Cancer Xenografts in Outbred Nude Mice Can Be Confounded by Polymorphisms in a Modifier of Tumorigenesis

PubMed Central

Zeineldin, Maged; Jensen, Derek; Paranjape, Smita R.; Parelkar, Nikhil K.; Jokar, Iman; Vielhauer, George A.; Neufeld, Kristi L.

2014-01-01

Tumorigenicity studies often employ outbred nude mice, in the absence of direct evidence that this mixed genetic background will negatively affect experimental outcome. Here we show that outbred nude mice carry two different alleles of Pla2g2a, a genetic modifier of intestinal tumorigenesis in mice. Here, we identify previous unreported linked polymorphisms in the promoter, noncoding and coding sequences of Pla2g2a and show that outbred nude mice from different commercial providers are heterogeneous for this polymorphic Pla2g2a allele. This heterogeneity even extends to mice obtained from a single commercial provider, which display mixed Pla2g2a genotypes. Notably, we demonstrated that the polymorphic Pla2g2a allele affects orthotopic xenograft establishment of human colon cancer cells in outbred nude mice. This finding establishes a non-cell-autonomous role for Pla2g2a in suppressing intestinal tumorigenesis. Using in vitro reporter assays and pharmacological inhibitors, we show promoter polymorphisms and nonsense-mediated RNA decay (NMD) as underlying mechanisms that lead to low Pla2g2a mRNA levels in tumor-sensitive mice. Together, this study provides mechanistic insight regarding Pla2g2a polymorphisms and demonstrates a non-cell-autonomous role for Pla2g2a in suppressing tumors. Moreover, our direct demonstration that mixed genetic backgrounds of outbred nude mice can significantly affect baseline tumorigenicity cautions against future use of outbred mice for tumor xenograft studies. PMID:24913681

MicroRNA203a suppresses glioma tumorigenesis through an ATM-dependent interferon response pathway

PubMed Central

Yang, Chuan He; Wang, Yinan; Sims, Michelle; Cai, Chun; He, Ping; Häcker, Hans; Yue, Junming; Cheng, Jinjun; Boop, Frederick A.; Pfeffer, Lawrence M.

2017-01-01

Glioblastoma (GBM) is a deadly and incurable brain tumor. Although microRNAs (miRNAs) play critical roles in regulating the cancer cell phenotype, the underlying mechanisms of how they regulate tumorigenesis are incompletely understood. We previously showed that miR-203a is expressed at relatively low levels in GBM patients, and ectopic miR-203a expression in GBM cell lines inhibited cell proliferation and migration, increased sensitivity to apoptosis induced by interferon (IFN) or temozolomide in vitro, and inhibited GBM tumorigenesis in vivo. Here we show that ectopic expression of miR-203a in GBM cell lines promotes the IFN response pathway as evidenced by increased IFN production and IFN-stimulated gene (ISG) expression, and high basal tyrosine phosphorylation of multiple STAT proteins. Importantly, we identified that miR-203a directly suppressed the protein levels of ataxia-telangiectasia mutated (ATM) kinase that negatively regulates IFN production. We found that high ATM expression in GBM correlates with poor patient survival and that ATM expression is inversely correlated with miR-203a expression. Knockout of ATM expression and inhibition of ATM function in GBM cell lines inhibited cell proliferation and migration, increased sensitivity to apoptosis induced by therapeutic agents in vitro, and markedly suppressed GBM tumor growth and promoted animal survival. In contrast, restoring ATM levels in GBM cells ectopically expressing miR-203a increased tumorigenicity and decreased animal survival. Our study suggests that low miR-203a expression in GBM suppresses the interferon response through an ATM-dependent pathway. PMID:29348882

MicroRNA203a suppresses glioma tumorigenesis through an ATM-dependent interferon response pathway.

PubMed

Yang, Chuan He; Wang, Yinan; Sims, Michelle; Cai, Chun; He, Ping; Häcker, Hans; Yue, Junming; Cheng, Jinjun; Boop, Frederick A; Pfeffer, Lawrence M

2017-12-22

Glioblastoma (GBM) is a deadly and incurable brain tumor. Although microRNAs (miRNAs) play critical roles in regulating the cancer cell phenotype, the underlying mechanisms of how they regulate tumorigenesis are incompletely understood. We previously showed that miR-203a is expressed at relatively low levels in GBM patients, and ectopic miR-203a expression in GBM cell lines inhibited cell proliferation and migration, increased sensitivity to apoptosis induced by interferon (IFN) or temozolomide in vitro , and inhibited GBM tumorigenesis in vivo . Here we show that ectopic expression of miR-203a in GBM cell lines promotes the IFN response pathway as evidenced by increased IFN production and IFN-stimulated gene (ISG) expression, and high basal tyrosine phosphorylation of multiple STAT proteins. Importantly, we identified that miR-203a directly suppressed the protein levels of ataxia-telangiectasia mutated (ATM) kinase that negatively regulates IFN production. We found that high ATM expression in GBM correlates with poor patient survival and that ATM expression is inversely correlated with miR-203a expression. Knockout of ATM expression and inhibition of ATM function in GBM cell lines inhibited cell proliferation and migration, increased sensitivity to apoptosis induced by therapeutic agents in vitro , and markedly suppressed GBM tumor growth and promoted animal survival. In contrast, restoring ATM levels in GBM cells ectopically expressing miR-203a increased tumorigenicity and decreased animal survival. Our study suggests that low miR-203a expression in GBM suppresses the interferon response through an ATM-dependent pathway.

TGF-Alpha Expression During Breast Tumorigenesis

DTIC Science & Technology

1999-07-01

contributors to breast tumorigenesis. Therefore, we examined TGFa expression in normal and transformed epithelium. We also examined TOFa and EGFR protein in...patient samples it is difficult to determine what effect tissue culture has on normal T(3Fa protein synthesis and processing. TOFa protein expression

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.

Focal Adhesion Kinase Is Required for Intestinal Regeneration and Tumorigenesis Downstream of Wnt/c-Myc Signaling

PubMed Central

Ashton, Gabrielle H.; Morton, Jennifer P.; Myant, Kevin; Phesse, Toby J.; Ridgway, Rachel A.; Marsh, Victoria; Wilkins, Julie A.; Athineos, Dimitris; Muncan, Vanesa; Kemp, Richard; Neufeld, Kristi; Clevers, Hans; Brunton, Valerie; Winton, Douglas J.; Wang, Xiaoyan; Sears, Rosalie C.; Clarke, Alan R.; Frame, Margaret C.; Sansom, Owen J.

2012-01-01

SUMMARY The intestinal epithelium has a remarkable capacity to regenerate after injury and DNA damage. Here, we show that the integrin effector protein Focal Adhesion Kinase (FAK) is dispensable for normal intestinal homeostasis and DNA damage signaling, but is essential for intestinal regeneration following DNA damage. Given Wnt/c-Myc signaling is activated following intestinal regeneration, we investigated the functional importance of FAK following deletion of the Apc tumor suppressor protein within the intestinal epithelium. Following Apc loss, FAK expression increased in a c-Myc-dependent manner. Codeletion of Apc and Fak strongly reduced proliferation normally induced following Apc loss, and this was associated with reduced levels of phospho-Akt and suppression of intestinal tumorigenesis in Apc heterozygous mice. Thus, FAK is required downstream of Wnt Signaling, for Akt/mTOR activation, intestinal regeneration, and tumorigenesis. Importantly, this work suggests that FAK inhibitors may suppress tumorigenesis in patients at high risk of developing colorectal cancer. PMID:20708588

Long non-coding RNA LINC00339 facilitates the tumorigenesis of non-small cell lung cancer by sponging miR-145 through targeting FOXM1.

PubMed

Yuan, Yuan; Haiying, Gao; Zhuo, Li; Ying, Lu; Xin, He

2018-06-12

Non-small cell lung cancer (NSCLC) is one of leading causes of cancer-related death worldwide. Long noncoding RNAs (lncRNAs) has been identified to modulate the tumorigenesis of NSCLC. However, the precise molecular mechanism of lncRNAs in the course is still unclear. Results showed that LINC00339 was significantly up-regulated in NSCLC tissue and cells, which indicated the poor prognosis of NSCLC patients. Loss-of-function experiments showed that LINC00339 silencing inhibited the proliferation and invasion, accelerated the apoptosis, and suppressed the tumor growth of NSCLC cells in vitro and in vivo. Luciferase reporter assay and RNA immunoprecipitation (RIP) revealed that LINC00339 promoted the NSCLC progression via FOXM1 via targeting miR-145. In conclusion, our results identify the important role of the LINC00339/miR-145/FOXM1 axis in the NSCLC tumorigenesis, providing neoteric mechanism for the NSCLC tumorigenesis. Copyright © 2018. Published by Elsevier Masson SAS.

Clonal Structure of Carcinogen-induced Intestinal Tumors in Mice

PubMed Central

Thliveris, Andrew T.; Clipson, Linda; White, Alanna; Waggoner, Jesse; Plesh, Lauren; Skinner, Bridget L.; Zahm, Christopher D.; Sullivan, Ruth; Dove, William F.; Newton, Michael A.; Halberg, Richard B.

2011-01-01

Previous studies have demonstrated that intestinal tumors from ApcMin/+ (Min) mice and Familial adenomatous polyposis (FAP) patients are often polyclonal. We sought to determine whether polyclonality is unique to tumors arising from hereditary predispositions or, instead, is a common feature of intestinal tumorigenesis in other pathways to tumorigenesis. Ethylnitrosourea-induced intestinal tumors from mice wildtype at the Apc locus and chimeric for the Rosa26 lineage marker were analyzed. Many were overtly polyclonal, being composed of a mixture of Rosa26+ and Rosa26− neoplastic cells. Statistical analyses revealed that polyclonality could be explained by interactions between two initiated clones separated by a very short distance. The frequency of overtly polyclonal tumors and the range of interactions estimated in this model are similar to those observed when analyzing familial tumors from Min mice. Thus, polyclonality does not depend on the familial pathway to tumorigenesis. Interactions between two initiated clones might provide a selective advantage during the early stages of intestinal tumorigenesis. PMID:21636550

Low-dose naltrexone suppresses ovarian cancer and exhibits enhanced inhibition in combination with cisplatin.

PubMed

Donahue, Renee N; McLaughlin, Patricia J; Zagon, Ian S

2011-07-01

Ovarian cancer is the leading cause of death from gynecological malignancies. Although initial therapeutic modalities are successful, 65% of these women relapse with only palliative treatments available thereafter. Endogenous opioids repress the proliferation of human ovarian cancer cells in vitro, and do so in a receptor-mediated manner. The present study examined whether modulation of opioid systems by the opioid antagonist naltrexone (NTX), alone or in combination with standard of care therapies (taxol/paclitaxel, cisplatin), alters human ovarian cancer cell proliferation in tissue culture and tumor progression in mice. Administration of NTX for six hours every two days, but not continuously, reduced DNA synthesis and cell replication from vehicle-treated controls in tissue culture. Moreover, brief exposure to NTX in combination with taxol or cisplatin had an enhanced anticancer action. Mice with established ovarian tumors and treated with a low dosage of NTX (LDN), which invokes a short period of opioid receptor blockade, repressed tumor progression in a non-toxic fashion by reducing DNA synthesis and angiogenesis but not altering cell survival. The combination of LDN with cisplatin, but not taxol, resulted in an additive inhibitory effect on tumorigenesis with enhanced depression of DNA synthesis and angiogenesis. LDN combined with cisplatin alleviated the toxicity (e.g. weight loss) associated with cisplatin. LDN treatment upregulated the expression of the opioid growth factor (OGF, chemical term ([Met(5)]-enkephalin) and its receptor, OGFr. Previous tissue culture studies have reported that OGF is the only opioid peptide with antiproliferative activity on ovarian cancer cells, with OGF action mediated by OGFr. Thus, the common denominator of intermittent opioid receptor blockade by short-term NTX or LDN on ovarian cancer proliferation and tumorigenesis recorded herein appears to be related to the OGF-OGFr axis. These preclinical data may offer a non-toxic and efficacious pathway-related treatment that can benefit patients with ovarian cancer.

Genetic Ablation of CCAAT/Enhancer Binding Protein α in Epidermis Reveals Its Role in Suppression of Epithelial Tumorigenesis

PubMed Central

Loomis, Kari D.; Zhu, Songyun; Yoon, Kyungsil; Johnson, Peter F.; Smart, Robert C.

2013-01-01

CCAAT/enhancer binding protein y (C/EBPα) is a basic leucine zipper transcription factor that inhibits cell cycle progression and regulates differentiation in various cell types. C/EBPα is inactivated by mutation in acute myeloid leukemia (AML) and is considered a human tumor suppressor in AML. Although C/EBPα mutations have not been observed in malignancies other than AML, greatly diminished expression of C/EBPα occurs in numerous human epithelial cancers including lung, liver, endometrial, skin, and breast, suggesting a possible tumor suppressor function. However, direct evidence for C/EBPα as an epithelial tumor suppressor is lacking due to the absence of C/EBPα mutations in epithelial tumors and the lethal effect of C/EBPα deletion in mouse model systems. To examine the function of C/EBPα in epithelial tumor development, an epidermal-specific C/EBPα knockout mouse was generated. The epidermal-specific C/EBPα knockout mice survived and displayed no detectable abnormalities in epidermal keratinocyte proliferation, differentiation, or apoptosis, showing that C/EBPα is dispensable for normal epidermal homeostasis. In spite of this, the epidermal-specific C/EBPα knockout mice were highly susceptible to skin tumor development involving oncogenic Ras. These mice displayed decreased tumor latency and striking increases in tumor incidence, multiplicity, growth rate, and the rate of malignant progression. Mice hemizygous for C/EBPα displayed an intermediate-enhanced tumor phenotype. Our results suggest that decreased expression of C/EBPα contributes to deregulation of tumor cell proliferation. C/EBPα had been proposed to block cell cycle progression through inhibition of E2F activity. We observed that C/EBPα blocked Ras-induced and epidermal growth factor-induced E2F activity in keratinocytes and also blocked Ras-induced cell transformation and cell cycle progression. Our study shows that C/EBPα is dispensable for epidermal homeostasis and provides genetic evidence that C/EBPα is a suppressor of epithelial tumorigenesis. PMID:17638888

The applied biochemistry of PEDF and implications for tissue homeostasis

PubMed Central

BROADHEAD, MATTHEW L.; BECERRA, S. PATRICIA; CHOONG, PETER F. M.; DASS, CRISPIN R.

2012-01-01

Pigment epithelium-derived factor (PEDF) is an endogenously produced glycoprotein with a spectrum of biological roles across diverse pathologies. Recent research has focused on the biochemical properties of PEDF and its associated receptors. This review discusses the recent developments in PEDF biochemistry and how this new knowledge will help progress our understanding of PEDF as a molecular mediator for anti-angiogenesis and -tumorigenesis. Additionally, pathophysiological roles for PEDF in healing and tissue homeostasis are being revealed and our enhanced understanding of the interactions between PEDF and its receptors may yet prove useful in propelling PEDF towards clinical application. PMID:20166889

Glioma progression through the prism of heat shock protein mediated extracellular matrix remodeling and epithelial to mesenchymal transition.

PubMed

Rajesh, Y; Biswas, Angana; Mandal, Mahitosh

2017-10-15

Glial tumor is one of the intrinsic brain tumors with high migratory and infiltrative potential. This essentially contributes to the overall poor prognosis by circumvention of conventional treatment regimen in glioma. The underlying mechanism in gliomagenesis is bestowed by two processes- Extracellular matrix (ECM) Remodeling and Epithelial to mesenchymal transition (EMT). Heat Shock Family of proteins (HSPs), commonly known as "molecular chaperons" are documented to be upregulated in glioma. A positive correlation also exists between elevated expression of HSPs and invasive capacity of glial tumor. HSPs overexpression leads to mutational changes in glioma, which ultimately drive cells towards EMT, ECM modification, malignancy and invasion. Differential expression of HSPs - a factor providing cytoprotection to glioma cells, also contributes towards its radioresistance /chemoresistance. Various evidences also display upregulation of EMT and ECM markers by various heat shock inducing proteins e.g. HSF-1. The aim of this review is to study in detail the role of HSPs in EMT and ECM leading to radioresistance/chemoresistance of glioma cells. The existing treatment regimen for glioma could be enhanced by targeting HSPs through immunotherapy, miRNA and exosome mediated strategies. This could be envisaged by better understanding of molecular mechanisms underlying glial tumorigenesis in relation to EMT and ECM remodeling under HSPs influence. Our review might showcase fresh potential for the development of next generation therapeutics for effective glioma management. Copyright © 2017 Elsevier Inc. All rights reserved.

The enhancing effect of ethanol on the mutagenic activation of N-nitrosomethylbenzylamine by cytochrome P450 2A in the rat oesophagus.

PubMed

Tatematsu, Kenjiro; Koide, Akihiro; Morimura, Keiichirou; Fukushima, Shoji; Mori, Yukio

2013-03-01

Alcohol consumption is frequently associated with various cancers and the enhancement of the metabolic activation of carcinogens has been proposed as a mechanism underlying this relationship. The ethanol-induced enhancement of N-nitrosodiethylamine (DEN)-mediated carcinogenesis can be attributed to an increase in hepatic activity. However, the mechanism of elevation of N-nitrosomethylbenzylamine (NMBA)-induced tumorigenesis remains unclear. To elucidate the mechanism underlying the role of ethanol in the enhancement of NMBA-induced oesophageal carcinogenesis, we evaluated the hepatic and extrahepatic levels of the cytochrome P450 (CYP) and mutagenic activation of environmental carcinogens by immunoblot analyses and Ames preincubation test, respectively, in F344 rats treated with ethanol. Five weeks of treatment with 10% ethanol added to the drinking water or two intragastric treatments with 50% ethanol, both resulted in elevated levels of CYP2E1 (1.5- to 2.3-fold) and mutagenic activities of DEN, N-nitrosodimethylamine and N-nitrosopyrrolidine in the presence of rat liver S9 (1.5- to 2.4-fold). This was not the case with CYP1A1/2, CYP2A1/2, CYP2B1/2 or CYP3A2, nor with the activities of 2-amino-3-methylimidazo[4,5-f]quinoline, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, aflatoxin B(1) or other N-nitroso compounds (NOCs), including NMBA. Ethanol-induced elevations of CYP2A and CYP2E1 were observed in the oesophagus (up to 1.7- and 2.3-fold) and kidney (up to 1.5- and 1.8-fold), but not in the lung or colon. In oesophagus and kidney, the mutagenic activities of NMBA and four NOCs were markedly increased (1.3- to 2.4-fold) in treated rats. The application of several CYP inhibitors revealed that CYP2A were likely to contribute to the enhancing effect of ethanol on NMBA activation in the rat oesophagus and kidney, but that CYP2E1 failed to do so. These results showed that the enhancing effect of ethanol on NMBA-induced oesophageal carcinogenesis could be attributed to an increase in the metabolic activation of NMBA by oesophageal CYP2A during the initiation phase, and that this occurred independently of CYP2E1.

The Role of DN-GSK3beta in Mammary Tumorigenesis

DTIC Science & Technology

2006-07-01

factors and dramatically increases their transcriptional activity. Genes up- regulated by TCF/LEF include embryologic genes, such as siamois and engrailed...and increased apoptosis occurs in the mammary epithelia (33). Overexpression of the regulator CK2a also promotes mammary tumorigenesis (34). In this

Fibroblast growth factor receptors: multifactorial-contributors to tumor initiation and progression.

PubMed

Feng, Shachuan; Zhou, Li; Nice, Edouard Collins; Huang, Canhua

2015-01-01

Fibroblast growth factor receptors (FGFRs), encoded by four genes (FGFR1, FGFR2, FGFR3, and FGFR4) are tightly associated with many biological processes such as organ development, cell proliferation and migration. Studies over the past decades have validated the pivotal roles FGFRs play in tumorigenesis due to the regulation of diverse tumorigenesis-related processes, including cell survival, proliferation, inflammation, metastasis and angiogenesis. Interestingly, FGFR mutations in somatic cells leading to tumorigenesis and those in germ cells leading to developmental disorders are identical, suggesting that FGFR mutations result in different diseases due to their spatio-temporal expression. Thus, discoveries in developmental biology may also be applicable to cancer. FGFRs regulate the expression and/or the activity of a myriad of molecules (e.g. matrix metalloproteinases (MMPs) and Snail) that are tightly linked to tumorigenesis by four main signaling pathways (RAS-MAPK, PI3K-AKT, PLCγ-PIP2, and STAT), as well as other minor branches. Epigenetic and genetic alteration of FGFR genes, including DNA methylation, histone remodeling, microRNA regulation, single nucleotide polymorphisms (SNPs), gene missense mutations, amplification, and fusion of FGFRs with other genes, which result in gain or loss of FGFR function, have been identified in many types of cancer. In this review, we focus in particular on recent advances in the relationship between FGFR disorders and tumorigenesis.

CYCLOPENTA-FUSED POLYCYCLIC AROMATIC HYDROCARBONS IN STRAIN A/J MOUSE LUNG: DNA ADDUCTS, ONCOGENE MUTATIONS, & TUMORIGENESIS

EPA Science Inventory

Cyclopenta-fused Polycyclic Aromatic Hydrocarbons in Strain AJJ Mouse Lung: DNA Adducts, Oncogene Mutations, and Tumorigenesis.

We have examined the relationships between DNA adducts, Ki-ras oncogene mutations, DNA adducts, and adenoma induction in the lungs of strain A/J...

Long term ethanol consumption promotes hepatic tumorigenesis but impairs normal hepatocyte proliferation in rats

USDA-ARS?s Scientific Manuscript database

Chronic and excessive alcohol consumption has been related to an increased risk of several cancers, including that of the liver; however, studies in animal models have yet to conclusively determine whether ethanol acts as a tumor promoter in hepatic tumorigenesis. We examined whether prolonged alcoh...

Overexpression of SAMD9 suppresses tumorigenesis and progression during non small cell lung cancer

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

Ma, Qing; Yu, Tao; Ren, Yao-Yao

2014-11-07

Highlights: • SAMD9 is down-regulated in human non-small cell lung cancer (NSCLC). • Knockdown of SAMD9 expression is increased the invasion, migration and proliferation in H1299 cells in vitro. • Overexpression of SAMD9 suppressed proliferation and invasion in A549 cells in vitro. • Depletion of SAMD9 increases tumor formation in vivo. - Abstract: The Sterile Alpha Motif Domain-containing 9 (SAMD9) gene has been recently emphasized during the discovery that it is expressed at a lower level in aggressive fibromatosis and some cases of breast and colon cancer, however, the underlying mechanisms are poorly understood. Here, we found that SAMD9 ismore » down-regulated in human non-small cell lung cancer (NSCLC). Furthermore, knockdown of SAMD9 expression is increased the invasion, migration and proliferation in H1299 cells in vitro and overexpression of SAMD9 suppressed proliferation and invasion in A549 cells. Finally, depletion of SAMD9 increases tumor formation in vivo. Our results may provide a strategy for blocking NSCLC tumorigenesis and progression.« less

Long Noncoding RNA LINC00958 Accelerates Gliomagenesis Through Regulating miR-203/CDK2.

PubMed

Guo, Erkun; Liang, Chaohui; He, Xin; Song, Guozhi; Liu, Hongjiang; Lv, Zhongqiang; Guan, Jianchao; Yang, Dezhen; Zheng, Jiapeng

2018-05-01

Increasing evidence has indicated that long noncoding RNAs (lncRNAs) play crucial roles in various biological processes, including glioma. However, the underlying mechanism of lncRNAs in gliomagenesis is still ambiguous. In this study, we aim to investigate the role of long intergenic noncoding RNA 00958 (LINC00958) in the tumorigenesis of glioma. Results revealed that LINC00958 was significantly upregulated in glioma tissues and cell lines compared with that of adjacent normal brain tissues and normal human astrocytes. Moreover, the ectopic overexpression of LINC00958 was correlated with poor prognosis of glioma patients. Loss-of-function experiments indicated that LINC00958 knockdown suppressed glioma cell proliferation, invasion, and induced cycle arrest at G0/G1 phase in vitro, and inhibited tumor growth in vivo. Bioinformatics programs and luciferase reporter assay revealed that miR-203 shared complementary binding sites with both 3'-untranslated region of LINC00958 and CDK2. In summary, our study concludes that LINC00958 acts as an oncogenic gene in the gliomagenesis through miR-203-CDK2 regulation, providing a novel insight into glioma tumorigenesis.

YAP forms autocrine loops with the ERBB pathway to regulate ovarian cancer initiation and progression.

PubMed

He, C; Lv, X; Hua, G; Lele, S M; Remmenga, S; Dong, J; Davis, J S; Wang, C

2015-12-10

Mechanisms underlying ovarian cancer initiation and progression are unclear. Herein, we report that the Yes-associated protein (YAP), a major effector of the Hippo tumor suppressor pathway, interacts with ERBB signaling pathways to regulate the initiation and progression of ovarian cancer. Immunohistochemistry studies indicate that YAP expression is associated with poor clinical outcomes in patients. Overexpression or constitutive activation of YAP leads to transformation and tumorigenesis in human ovarian surface epithelial cells, and promotes growth of cancer cells in vivo and in vitro. YAP induces the expression of epidermal growth factor (EGF) receptors (EGFR, ERBB3) and production of EGF-like ligands (HBEGF, NRG1 and NRG2). HBEGF or NRG1, in turn, activates YAP and stimulates cancer cell growth. Knockdown of ERBB3 or HBEGF eliminates YAP effects on cell growth and transformation, whereas knockdown of YAP abrogates NRG1- and HBEGF-stimulated cell proliferation. Collectively, our study demonstrates the existence of HBEGF & NRGs/ERBBs/YAP/HBEGF & NRGs autocrine loop that controls ovarian cell tumorigenesis and cancer progression.

The Hippo-YAP Pathway Regulates 3D Organ Formation and Homeostasis.

PubMed

Ishihara, Erika; Nishina, Hiroshi

2018-04-17

The vertebrate body shape is formed by the specific sizes and shapes of its resident tissues and organs, whose alignments are essential for proper functioning. To maintain tissue and organ shape, and thereby function, it is necessary to remove senescent, transformed, and/or damaged cells, which impair function and can lead to tumorigenesis. However, the molecular mechanisms underlying three-dimensional (3D) organ formation and homeostasis are not fully clear. Yes-associated protein (YAP) is a transcriptional co-activator that is involved in organ size control and tumorigenesis. Recently, we reported that YAP is essential for proper 3D body shape through regulation of cell tension by using a unique medaka fish mutant, hirame ( hir ). In Madin–Darby canine kidney (MDCK) epithelial cells, active YAP-transformed cells are eliminated apically when surrounded by normal cells. Furthermore, in a mosaic mouse model, active YAP-expressing damaged hepatocytes undergo apoptosis and are eliminated from the liver. Thus, YAP functions in quantitative and quality control in organogenesis. In this review, we describe the various roles of YAP in vertebrates, including in the initiation of liver cancer.

Unraveling the Molecular Mechanism(s) Underlying ER+/PR- Breast Tumorigenesis Using a Novel Genetically Engineered Mouse Model

DTIC Science & Technology

2010-09-01

Gria4 Glutamate receptor ionotropic , AMPA 4 NM_019691 transport ion transport 3.00 Slc2a1 solute carrier family 2,member 1 NM_011400...unlimited 13. SUPPLEMENTARY NOTES 14. A BSTRACT Estrogen-rece ptor alpha (E Rα)-positive Progesterone receptor ne gative (ER+ /PR-) breast ductal...fo r t reating ER+/PR- breast cancers that are resistant to tamoxifen or trastuzumab. 15. SUBJECT TERMS Estrogen receptor , Progesterone receptor

Constitutively active transforming growth factor β receptor 1 in the mouse ovary promotes tumorigenesis

PubMed Central

Gao, Yang; Vincent, David F.; Davis, Anna Jane; Sansom, Owen J.; Bartholin, Laurent; Li, Qinglei

2016-01-01

Despite the well-established tumor suppressive role of TGFβ proteins, depletion of key TGFβ signaling components in the mouse ovary does not induce a growth advantage. To define the role of TGFβ signaling in ovarian tumorigenesis, we created a mouse model expressing a constitutively active TGFβ receptor 1 (TGFBR1) in ovarian somatic cells using conditional gain-of-function approach. Remarkably, these mice developed ovarian sex cord-stromal tumors with complete penetrance, leading to reproductive failure and mortality. The tumors expressed multiple granulosa cell markers and caused elevated serum inhibin and estradiol levels, reminiscent of granulosa cell tumors. Consistent with the tumorigenic effect, overactivation of TGFBR1 altered tumor microenvironment by promoting angiogenesis and enhanced ovarian cell proliferation, accompanied by impaired cell differentiation and dysregulated expression of critical genes in ovarian function. By further exploiting complementary genetic models, we substantiated our finding that constitutively active TGFBR1 is a potent oncogenic switch in mouse granulosa cells. In summary, overactivation of TGFBR1 drives gonadal tumor development. The TGFBR1 constitutively active mouse model phenocopies a number of morphological, hormonal, and molecular features of human granulosa cell tumors and are potentially valuable for preclinical testing of targeted therapies to treat granulosa cell tumors, a class of poorly defined ovarian malignancies. PMID:27344183

L1-CAM in cancerous tissues.

PubMed

Gavert, Nancy; Ben-Shmuel, Amir; Raveh, Shani; Ben-Ze'ev, Avri

2008-11-01

L1-cell adhesion molecule (L1-CAM) is a cell adhesion receptor of the immunoglobulin superfamily, known for its roles in nerve cell function. While originally believed to be present only in brain cells, in recent years L1-CAM has been detected in other tissues, and in a variety of cancer cells, including some common types of human cancer. We review the prevalence of L1-CAM in human cancer, the possible mechanisms involved in L1-CAM-mediated tumorigenesis, and cancer therapies based upon L1-CAM antibody treatment. In colon cancer cells, the L1-CAM gene was identified as a target of the Wnt/beta-catenin-TCF signaling pathway, and L1-CAM was exclusively detected at the invasive front of colon and ovarian cancer tissue. The expression of L1-CAM in normal and cancer cells enhanced tumorigenesis and conferred metastasis in colon cancer cells. Antibodies against the L1-CAM ectodomain severely inhibited the proliferation of a variety of cancer cells in culture and reduced tumor burden when injected into mice harboring cancer cells expressing L1-CAM. These results, in addition to the presence of L1-CAM on the cell surface and its restricted distribution in normal tissues, make it an ideal target for tumor therapy.

Tetraspanin TM4SF5 mediates loss of contact inhibition through epithelial-mesenchymal transition in human hepatocarcinoma

PubMed Central

Lee, Sin-Ae; Lee, Sung-Yul; Cho, Ik-Hyun; Oh, Min-A; Kang, Eun-Sil; Kim, Yong-Bae; Seo, Woo Duck; Choi, Suyong; Nam, Ju-Ock; Tamamori-Adachi, Mimi; Kitajima, Shigetaka; Ye, Sang-Kyu; Kim, Semi; Hwang, Yoon-Jin; Kim, In-San; Park, Ki Hun; Lee, Jung Weon

2008-01-01

The growth of normal cells is arrested when they come in contact with each other, a process known as contact inhibition. Contact inhibition is lost during tumorigenesis, resulting in uncontrolled cell growth. Here, we investigated the role of the tetraspanin transmembrane 4 superfamily member 5 (TM4SF5) in contact inhibition and tumorigenesis. We found that TM4SF5 was overexpressed in human hepatocarcinoma tissue. TM4SF5 expression in clinical samples and in human hepatocellular carcinoma cell lines correlated with enhanced p27Kip1 expression and cytosolic stabilization as well as morphological elongation mediated by RhoA inactivation. These TM4SF5-mediated effects resulted in epithelial-mesenchymal transition (EMT) via loss of E-cadherin expression. The consequence of this was aberrant cell growth, as assessed by S-phase transition in confluent conditions, anchorage-independent growth, and tumor formation in nude mice. The TM4SF5-mediated effects were abolished by suppressing the expression of either TM4SF5 or cytosolic p27Kip1, as well as by reconstituting the expression of E-cadherin. Our observations have revealed a role for TM4SF5 in causing uncontrolled growth of human hepatocarcinoma cells through EMT. PMID:18357344

Metallothionein-3 Increases Triple-Negative Breast Cancer Cell Invasiveness via Induction of Metalloproteinase Expression

PubMed Central

Suchanski, Jaroslaw; Olbromski, Mateusz; Gomulkiewicz, Agnieszka; Owczarek, Tomasz; Kruczak, Anna; Ambicka, Aleksandra; Rys, Janusz; Ugorski, Maciej; Podhorska-Okolow, Marzena; Dziegiel, Piotr

2015-01-01

It has been recently found that metallothionein-3 (MT3) enhances the invasiveness and tumorigenesis of prostate cancer cells. This finding is in contrast to those of earlier studies, which indicated that overexpression of MT3 in breast cancer and prostate cancer cell lines inhibits their growth in vitro. Therefore, to clarify the role of MT3 in breast cancer progression, we analyzed the effect of MT3-overexpression on proliferation, invasiveness, migration, and tumorigenesis of breast cancer MDA-MB-231/BO2 cells. It was found that MDA-MB-231/BO2 cells overexpressing MT3 were characterized by increased invasiveness in vitro, compared to the control cells. Interestingly, this increased invasiveness correlated with a highly increased concentration of MMP3 in the culture supernatants (p<0.0001). Our data suggest that MT3 may regulate breast cancer cell invasiveness by modulating the expression of MMP3. These experimental results, obtained using triple-negative MDA-MB-231/BO2 cells, were further supported by clinical data. It was found that, in triple-negative breast cancer (TNBC), nuclear MT3 immunoreactivity in cancer cells tended to be associated with patients’ shorter disease-specific survival, suggesting that nuclear MT3 expression may be a potential marker of poor prognosis of triple-negative TNBC cases. PMID:25933064

BHD-associated kidney cancer exhibits unique molecular characteristics and a wide variety of variants in chromatin remodeling genes.

PubMed

Hasumi, Hisashi; Furuya, Mitsuko; Tatsuno, Kenji; Yamamoto, Shogo; Baba, Masaya; Hasumi, Yukiko; Isono, Yasuhiro; Suzuki, Kae; Jikuya, Ryosuke; Otake, Shinji; Muraoka, Kentaro; Osaka, Kimito; Hayashi, Narihiko; Makiyama, Kazuhide; Miyoshi, Yasuhide; Kondo, Keiichi; Nakaigawa, Noboru; Kawahara, Takashi; Izumi, Koji; Teranishi, Junichi; Yumura, Yasushi; Uemura, Hiroji; Nagashima, Yoji; Metwalli, Adam R; Schmidt, Laura S; Aburatani, Hiroyuki; Linehan, W Marston; Yao, Masahiro

2018-05-14

Birt-Hogg-Dubé (BHD) syndrome is a hereditary kidney cancer syndrome, which predisposes patients to develop kidney cancer, cutaneous fibrofolliculomas and pulmonary cysts. The responsible gene FLCN is a tumor suppressor for kidney cancer which plays an important role in energy homeostasis through the regulation of mitochondrial oxidative metabolism. However, the process by which FLCN-deficiency leads to renal tumorigenesis is unclear. In order to clarify molecular pathogenesis of BHD-associated kidney cancer, we conducted whole-exome sequencing analysis using next-generation sequencing technology as well as metabolite analysis using LC/MS and GC/MS. Whole-exome sequencing analysis of BHD-associated kidney cancer revealed that copy number variations (CNV) of BHD-associated kidney cancer are considerably different from those already reported in sporadic cases. In somatic variant analysis, very few variants were commonly observed in BHD-associated kidney cancer; however, variants in chromatin remodeling genes were frequently observed in BHD-associated kidney cancer (17/29 tumors, 59%). Metabolite analysis of BHD-associated kidney cancer revealed metabolic reprogramming towards upregulated redox regulation which may neutralize reactive oxygen species potentially produced from mitochondria with increased respiratory capacity under FLCN-deficiency. BHD-associated kidney cancer displays unique molecular characteristics which are completely different from sporadic kidney cancer, providing mechanistic insight into tumorigenesis under FLCN-deficiency as well as a foundation for development of novel therapeutics for kidney cancer.

Aging tumour cells to cure cancer: "pro-senescence" therapy for cancer.

PubMed

Calcinotto, Arianna; Alimonti, Andrea

2017-01-19

Robust scientific evidence demonstrates that senes-cence induction in cancer works as a potent weapon to eradicate tumorigenesis. Therapies that enhance senescence not only promote a stable cell growth arrest but also work as a strong stimulus for the acti-vation of the antitumour immune response. However, recent advances suggest that if senescent tumour cells are not cleared from the tumours, they may promote tumour progression and metastasis. In this article, we focus on concepts that are relevant to a pro-senescence therapeutic approach, including caveats, and we propose therapeutic strategies that involve the combined use of pro-senescence therapies with im-munotherapies to promote the clearance of senescent tumour cells. In our opinion, these approaches may avoid potential negative effects of pro-senescence therapies and may also enhance the efficacy of cur-rently available immunotherapies.

All-Trans Retinoic Acid-Induced Deficiency of the Wnt/β-Catenin Pathway Enhances Hepatic Carcinoma Stem Cell Differentiation

PubMed Central

Zhang, Xia; Bai, Jianhua; Chen, Gang; Li, Li; Li, Meizhang

2015-01-01

Retinoic acid (RA) is an important biological signal that directly differentiates cells during embryonic development and tumorigenesis. However, the molecular mechanism of RA-mediated differentiation in hepatic cancer stem cells (hCSCs) is not well understood. In this study, we found that mRNA expressions of RA-biosynthesis-related dehydrogenases were highly expressed in hepatocellular carcinoma. All-trans retinoic acid (ATRA) differentiated hCSCs through inhibiting the function of β-catenin in vitro. ATRA also inhibited the function of PI3K-AKT and enhanced GSK-3β-dependent degradation of phosphorylated β-catenin. Furthermore, ATRA and β-catenin silencing both increased hCSC sensitivity to docetaxel treatment. Our results suggest that targeting β-catenin will provide extra benefits for ATRA-mediated treatment of hepatic cancer patients. PMID:26571119

miR-935 suppresses gastric signet ring cell carcinoma tumorigenesis by targeting Notch1 expression

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

Yan, Chao; Yu, Jianchun, E-mail: yu_jchpumch@163.com; Kang, Weiming

Gastric signet ring cell carcinoma (GSRCC) is a unique pathological type of gastric carcinoma that is extremely invasive and has a poor prognosis. Expression of microRNAs (miRNAs) has been closely linked to the carcinogenesis of gastric cancer and has been considered as a powerful prognostic marker. The function of miR-935 has never been reported in cancer before. We found, using microRNA array, that expression of miR-935 in GSRCC cell lines is lower than in non-GSRCC cell lines, and enhanced expression of miR-935 in GSRCC cell-lines inhibit cell proliferation, migration and invasion. We also identified Notch1 as a direct target ofmore » miR-935. Knockdown of Notch1 reduced proliferation, migration/invasion of GSRCC cells, and overexpression Notch1's activated form (Notch intracellular domain) could rescue miR-935's tumor suppressive effect on GSRCC. Expression of miR-935 was lower in gastric carcinoma tissue than in paired normal tissue samples, and lower in GSRCC than in non-GSRCC. Our results demonstrate the inverse correlation between the expression of miR-935 and Notch1 in gastric tissues. We conclude that miR-935 inhibits gastric carcinoma cell proliferation, migration and invasion by targeting Notch1, suggesting potential applications of the miR-935-Notch1 pathway in gastric cancer clinical diagnosis and therapeutics, especially in gastric signet ring cell carcinoma. - Highlights: • The expression of miR-935 is lower in GC tissue than in paired normal tissue. • The expression of miR-935 is lower in GSRCC tissue than in non-GSRCC. • Enhanced expression of miR-935 suppresses tumorigenesis of GSRCC. • Notch1 is a direct target of miR-935.« less

Staurosporine synergistically potentiates the deoxycholate-mediated induction of COX-2 expression.

PubMed

Saeki, Tohru; Inui, Haruka; Fujioka, Saya; Fukuda, Suguru; Nomura, Ayumi; Nakamura, Yasushi; Park, Eun Young; Sato, Kenji; Kanamoto, Ryuhei

2014-08-01

Colorectal cancer is a major cause of cancer-related death in western countries, and thus there is an urgent need to elucidate the mechanism of colorectal tumorigenesis. A diet that is rich in fat increases the risk of colorectal tumorigenesis. Bile acids, which are secreted in response to the ingestion of fat, have been shown to increase the risk of colorectal tumors. The expression of cyclooxygenase (COX)-2, an inducible isozyme of cyclooxygenase, is induced by bile acids and correlates with the incidence and progression of cancers. In this study, we investigated the signal transduction pathways involved in the bile-acid-mediated induction of COX-2 expression. We found that staurosporine (sts), a potent protein kinase C (PKC) inhibitor, synergistically potentiated the deoxycholate-mediated induction of COX-2 expression. Sts did not increase the stabilization of COX-2 mRNA. The sts- and deoxycholate-mediated synergistic induction of COX-2 expression was suppressed by a membrane-permeable Ca(2+) chelator, a phosphoinositide 3-kinase inhibitor, a nuclear factor-κB pathway inhibitor, and inhibitors of canonical and stress-inducible mitogen-activated protein kinase pathways. Inhibition was also observed using PKC inhibitors, suggesting the involvement of certain PKC isozymes (η, θ, ι, ζ, or μ). Our results indicate that sts exerts its potentiating effects via the phosphorylation of p38. However, the effects of anisomycin did not mimic those of sts, indicating that although p38 activation is required, it does not enhance deoxycholate-induced COX-2 expression. We conclude that staurosporine synergistically enhances deoxycholate-induced COX-2 expression in RCM-1 colon cancer cells. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Interaction of AIP with protein kinase A (cAMP-dependent protein kinase).

PubMed

Schernthaner-Reiter, Marie Helene; Trivellin, Giampaolo; Stratakis, Constantine A

2018-05-02

Germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene cause mostly somatotropinomas and/or prolactinomas in a subset of familial isolated pituitary adenomas (FIPA). AIP has been shown to interact with phosphodiesterases (PDEs) and G proteins, suggesting a link to the cyclic AMP (cAMP)-dependent protein kinase (PKA) pathway. Upregulation of PKA is seen in sporadic somatotropinomas that carry GNAS1 mutations, and those in Carney complex that are due to PRKAR1A mutations. To elucidate the mechanism of AIP-dependent pituitary tumorigenesis, we studied potential functional and physical interactions of AIP with PKA's main subunits PRKAR1A (R1α) and PRKACA (Cα). We found that AIP physically interacts with both R1α and Cα; this interaction is enhanced when all three components are present, but maintained during Cα-R1α dissociation by PKA pathway activation, indicating that AIP binds Cα/R1α both in complex and separately. The interaction between AIP and R1α/Cα is reduced when the frequent AIP pathogenic mutation p.R304* is present. AIP protein levels are regulated both by translation and the ubiquitin/proteasome pathway and Cα stabilizes both AIP and R1α protein levels. AIP reduction by siRNA leads to an increase of PKA pathway activity, which is disproportionately enhanced during PDE4-inhibition. We show that AIP interacts with the PKA pathway on multiple levels, including a physical interaction with both the main regulatory (R1α) and catalytic (Cα) PKA subunits and a functional interaction with PDE4-dependent PKA activation. These findings provide novel insights on the mechanisms of AIP-dependent pituitary tumorigenesis.

microRNA-221 Enhances MYCN via Targeting Nemo-like Kinase and Functions as an Oncogene Related to Poor Prognosis in Neuroblastoma.

PubMed

He, Xiao-Yan; Tan, Zheng-Lan; Mou, Qin; Liu, Fang-Jie; Liu, Shan; Yu, Chao-Wen; Zhu, Jin; Lv, Lin-Ya; Zhang, Jun; Wang, Shan; Bao, Li-Ming; Peng, Bin; Zhao, Hui; Zou, Lin

2017-06-01

Purpose: MYCN is one of the most well-characterized genetic markers of neuroblastoma. However, the mechanisms as to how MYCN mediate neuroblastoma tumorigenesis are not fully clear. Increasing evidence has confirmed that the dysregulation of miRNAs is involved in MYCN-mediated neuroblastoma tumorigenesis, supporting their potential as therapeutic targets for neuroblastoma. Although miR-221 has been reported as one of the upregulated miRNAs, the interplay between miR-221 and MYCN-mediated neuroblastoma progression remains largely elusive. Experimental Design: The expression of miR-221 in the formalin-fixed, paraffin-embedded tissues from 31 confirmed patients with neuroblastoma was detected by locked nucleic acid- in situ hybridization and qRT-PCR. The correlation between miR-221 expression and clinical features in patients with neuroblastoma was assessed. The mechanisms as to how miR-221 regulate MYCN in neuroblastoma were addressed. The effect of miR-221 on cellular proliferation in neuroblastoma was determined both in vitro and in vivo Results: miR-221 was significantly upregulated in neuroblastoma tumor cells and tissues that overexpress MYCN, and high expression of miR-221 was positively associated with poor survival in patients with neuroblastoma. Nemo-like kinase (NLK) as a direct target of miR-221 in neuroblastoma was verified. In addition, overexpression of miR-221 decreased LEF1 phosphorylation but increased the expression of MYCN via targeting of NLK and further regulated cell cycle, particularly in S-phase, promoting the growth of neuroblastoma cells. Conclusions: This study provides a novel insight for miR-221 in the control of neuroblastoma cell proliferation and tumorigenesis, suggesting potentials of miR-221 as a prognosis marker and therapeutic target for patients with MYCN overexpressing neuroblastoma. Clin Cancer Res; 23(11); 2905-18. ©2016 AACR . ©2016 American Association for Cancer Research.

Efficacy of melatonin, IL-25 and siIL-17B in tumorigenesis-associated properties of breast cancer cell lines.

PubMed

Gelaleti, Gabriela Bottaro; Borin, Thaiz Ferraz; Maschio-Signorini, Larissa Bazela; Moschetta, Marina Gobbe; Jardim-Perassi, Bruna Victorasso; Calvinho, Guilherme Berto; Facchini, Mariana Castilho; Viloria-Petit, Alicia M; de Campos Zuccari, Debora Aparecida Pires

2017-08-15

Mammary tumorigenesis can be modulated by melatonin, which has oncostatic action mediated by multiple mechanisms, including the inhibition of the activity of transcription factors such as NF-κB and modulation of interleukins (ILs) expression. IL-25 is an active cytokine that induces apoptosis in tumor cells due to differential expression of its receptor (IL-17RB). IL-17B competes with IL-25 for binding to IL-17RB in tumor cells, promoting tumorigenesis. This study purpose is to address the possibility of engaging IL-25/IL-17RB signaling to enhance the effect of melatonin on breast cancer cells. Breast cancer cell lines were cultured monolayers and 3D structures and treated with melatonin, IL-25, siIL-17B, each alone or in combination. Cell viability, gene and protein expression of caspase-3, cleaved caspase-3 and VEGF-A were performed by qPCR and immunofluorescence. In addition, an apoptosis membrane array was performed in metastatic cells. Treatments with melatonin and IL-25 significantly reduced tumor cells viability at 1mM and 1ng/mL, respectively, but did not alter cell viability of a non-tumorigenic epithelial cell line (MCF-10A). All treatments, alone and combined, significantly increased cleaved caspase-3 in tumor cells grown as monolayers and 3D structures (p<0.05). Semi-quantitative analysis of apoptosis pathway proteins showed an increase of CYTO-C, DR6, IGFBP-3, IGFBP-5, IGFPB-6, IGF-1, IGF-1R, Livin, P21, P53, TNFRII, XIAP and hTRA proteins and reduction of caspase-3 (p<0.05) after melatonin treatment. All treatments reduced VEGF-A protein expression in tumor cells (p<0.05). Our results suggest therapeutic potential, with oncostatic effectiveness, pro-apoptotic and anti-angiogenic properties for melatonin and IL-25-driven signaling in breast cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

A positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells

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

Zhang, Qiao, E-mail: zhangqiao200824@126.com; Yang, Zhe, E-mail: zheyang@bjmu.edu.cn; Wang, Weiping, E-mail: wwp@bjmu.edu.cn

2014-07-04

Highlights: • ISL-1 is highly expressed in human pancreatic β-cells and DLBCL. • ISL-1 accelerates the tumorigenesis of DLBCL in vivo. • c-Myc positively regulates ISL-1 expression in DLBCL but not in pancreatic β-cells. • ISL-1 and c-Myc forms an ISL-1/c-Myc transcriptional complex only in DLBCL. • Positive feedback regulation of ISL-1 does not exist in normal pancreatic β-cell. - Abstract: Insulin enhancer binding protein-1 (ISL-1), a LIM-homeodomain transcription factor, has been reported to play essential roles in promoting adult pancreatic β-cells proliferation. Recent studies indicate that ISL-1 may also involve in the occurrence of a variety of tumors. However,more » whether ISL-1 has any functional effect on tumorigenesis, and what are the differences on ISL-1 function in distinct conditions, are completely unknown. In this study, we found that ISL-1 was highly expressed in human pancreatic β-cells, as well as in diffuse large B cell lymphoma (DLBCL), but to a much less extent in other normal tissues or tumor specimens. Further study revealed that ISL-1 promoted the proliferation of pancreatic β-cells and DLBCL cells, and also accelerated the tumorigenesis of DLBCL in vivo. We also found that ISL-1 could activate c-Myc transcription not only in pancreatic β-cells but also in DLBCL cells. However, a cell-specific feedback regulation was detectable only in DLBCL cells. This auto-regulatory loop was established by the interaction of ISL-1 and c-Myc to form an ISL-1/c-Myc transcriptional complex, and synergistically to promote ISL-1 transcription through binding on the ISL-1 promoter. Taken together, our results demonstrate a positive feedback regulation of ISL-1 in DLBCL but not in pancreatic β-cells, which might result in the functional diversities of ISL-1 in different physiological and pathological processes.« less

Arousal of cancer-associated stroma: overexpression of palladin activates fibroblasts to promote tumor invasion.

PubMed

Brentnall, Teresa A; Lai, Lisa A; Coleman, Joshua; Bronner, Mary P; Pan, Sheng; Chen, Ru

2012-01-01

Cancer-associated fibroblasts, comprised of activated fibroblasts or myofibroblasts, are found in the stroma surrounding solid tumors. These myofibroblasts promote invasion and metastasis of cancer cells. Mechanisms regulating the activation of the fibroblasts and the initiation of invasive tumorigenesis are of great interest. Upregulation of the cytoskeletal protein, palladin, has been detected in the stromal myofibroblasts surrounding many solid cancers and in expression screens for genes involved in invasion. Using a pancreatic cancer model, we investigated the functional consequence of overexpression of exogenous palladin in normal fibroblasts in vitro and its effect on the early stages of tumor invasion. Palladin expression in stromal fibroblasts occurs very early in tumorigenesis. In vivo, concordant expression of palladin and the myofibroblast marker, alpha smooth muscle actin (α-SMA), occurs early at the dysplastic stages in peri-tumoral stroma and progressively increases in pancreatic tumorigenesis. In vitro introduction of exogenous 90 kD palladin into normal human dermal fibroblasts (HDFs) induces activation of stromal fibroblasts into myofibroblasts as marked by induction of α-SMA and vimentin, and through the physical change of cell morphology. Moreover, palladin expression in the fibroblasts enhances cellular migration, invasion through the extracellular matrix, and creation of tunnels through which cancer cells can follow. The fibroblast invasion and creation of tunnels results from the development of invadopodia-like cellular protrusions which express invadopodia proteins and proteolytic enzymes. Palladin expression in fibroblasts is triggered by the co-culture of normal fibroblasts with k-ras-expressing epithelial cells. Overall, palladin expression can impart myofibroblast properties, in turn promoting the invasive potential of these peri-tumoral cells with invadopodia-driven degradation of extracellular matrix. Palladin expression in fibroblasts can be triggered by k-ras expression in adjacent epithelial cells. This data supports a model whereby palladin-activated fibroblasts facilitate stromal-dependent metastasis and outgrowth of tumorigenic epithelium.

A syndrome of multiorgan hyperplasia with features of gigantism, tumorigenesis, and female sterility in p27(Kip1)-deficient mice.

PubMed

Fero, M L; Rivkin, M; Tasch, M; Porter, P; Carow, C E; Firpo, E; Polyak, K; Tsai, L H; Broudy, V; Perlmutter, R M; Kaushansky, K; Roberts, J M

1996-05-31

Targeted disruption of the murine p27(Kip1) gene caused a gene dose-dependent increase in animal size without other gross morphologic abnormalities. All tissues were enlarged and contained more cells, although endocrine abnormalities were not evident. Thymic hyperplasia was associated with increased T lymphocyte proliferation, and T cells showed enhanced IL-2 responsiveness in vitro. Thus, p27 deficiency may cause a cell-autonomous defect resulting in enhanced proliferation in response to mitogens. In the spleen, the absence of p27 selectively enhanced proliferation of hematopoietic progenitor cells. p27 deletion, like deletion of the Rb gene, uniquely caused neoplastic growth of the pituitary pars intermedia, suggesting that p27 and Rb function in the same regulatory pathway. The absence of p27 also caused an ovulatory defect and female sterility. Maturation of secondary ovarian follicles into corpora lutea, which express high levels of p27, was markedly impaired.

Maternal B-vitamin supplementation from preconception through weaning suppresses intestinal tumorigenesis in Apc+/1638N mouse offspring

USDA-ARS?s Scientific Manuscript database

Variations in the intake of folate are capable of modulating colorectal tumorigenesis; however the outcome appears to be dependent on timing. We sought to determine the effect of altering folate (and related B vitamin) availability during in utero development and the suckling period on intestinal tu...

Lycopene metabolite, apo-10'-lycopenoic acid, inhibits diethylnitrosamine-initiated, high fat diet-promoted hepatic inflammation and tumorigenesis in mice

USDA-ARS?s Scientific Manuscript database

Obesity is associated with increased risk in hepatocellular carcinoma (HCC) development and mortality. An important disease control strategy is the prevention of obesity-related hepatic inflammation and tumorigenesis by dietary means. Here, we report that apo-10'-lycopenoic acid (APO10LA), a cleavag...

Senescence and the pro-tumorigenic stroma.

PubMed

Alspach, Elise; Fu, Yujie; Stewart, Sheila A

2013-01-01

Hayflick and Moorhead first described senescence in the late 1960's as a permanent growth arrest that primary cells underwent after a defined number of cellular divisions in culture. This observation gave rise to the hypothesis that cells contained an internal counting mechanism that limited cellular division and that this limit was an important barrier to cellular transformation. What began as an in vitro observation has led to an immense body of work that reaches into all fields of biology and is of particular interest in the areas of aging, tissue regeneration, and tumorigenesis. The initially simplistic view that senescence limits cellular division and contributes to aging while stymying tumorigenesis has now evolved into an important and complex biological process that has numerous caveats and often opposing effects on tumorigenesis. In this review, we limit our discussion to the complex role senescence plays in tumorigenesis. Throughout the review we attempt to draw many parallels to other systems including the role senescent cells play in the tumor microenvironment and their significant molecular and phenotypic similarities to cancer associated fibroblasts (CAFs).

SEA: a super-enhancer archive.

PubMed

Wei, Yanjun; Zhang, Shumei; Shang, Shipeng; Zhang, Bin; Li, Song; Wang, Xinyu; Wang, Fang; Su, Jianzhong; Wu, Qiong; Liu, Hongbo; Zhang, Yan

2016-01-04

Super-enhancers are large clusters of transcriptional enhancers regarded as having essential roles in driving the expression of genes that control cell identity during development and tumorigenesis. The construction of a genome-wide super-enhancer database is urgently needed to better understand super-enhancer-directed gene expression regulation for a given biology process. Here, we present a specifically designed web-accessible database, Super-Enhancer Archive (SEA, http://sea.edbc.org). SEA focuses on integrating super-enhancers in multiple species and annotating their potential roles in the regulation of cell identity gene expression. The current release of SEA incorporates 83 996 super-enhancers computationally or experimentally identified in 134 cell types/tissues/diseases, including human (75 439, three of which were experimentally identified), mouse (5879, five of which were experimentally identified), Drosophila melanogaster (1774) and Caenorhabditis elegans (904). To facilitate data extraction, SEA supports multiple search options, including species, genome location, gene name, cell type/tissue and super-enhancer name. The response provides detailed (epi)genetic information, incorporating cell type specificity, nearby genes, transcriptional factor binding sites, CRISPR/Cas9 target sites, evolutionary conservation, SNPs, H3K27ac, DNA methylation, gene expression and TF ChIP-seq data. Moreover, analytical tools and a genome browser were developed for users to explore super-enhancers and their roles in defining cell identity and disease processes in depth. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

METCAM/MUC18 promoted tumorigenesis of human breast cancer SK-BR-3 cells in a dosage-specific manner.

PubMed

Huang, Chang-Yu; Wu, Guang-Jer

2016-04-01

Overexpression of METCAM/MUC18, an immunoglobulin-like cell-adhesion molecule, promotes tumorigenesis and progression of human breast cancer cells. We also observed an intriguing phenomenon that a high-expressing SK-BR-3 clone manifested a transient tumor suppression effect in vivo. The purpose of this study was to understand if this was caused by clonal variation, METCAM/MUC18-dosage effect, or the number of cells injected. Several G418-resistant clones of SK-BR-3, expressing different levels of METCAM/MUC18, were obtained for testing effects of human METCAM/MUC18 on in vitro motility, invasiveness, and anchorage-independent colony formation (in vitro tumorigenicity) and in vivo tumorigenesis in female Balb/C athymic nude mice. Tumor sections were made for histology and immunohistochemistry analyses, and tumor lysates for Western blot analysis to determine the effects of human METCAM/MUC18 expression on levels of various downstream effectors. METCAM/MUC18 promoted in vitro motility, invasiveness, and in vitro tumorigenicity of SK-BR-3 cells in a dosage-specific manner. Overexpression of METCAM/MUC18 could promote in vivo tumorigenesis of SK-BR-3 cells even when one tenth of the previously used cell number (5 × 10(5)) was injected and in vivo tumorigenesis of SK-BR-3 cells was directly proportional to the dosage of the protein. The previously observed transient tumor suppression effect from the same clone was no longer observed. The downstream effector, such as phospho-AKT/AKT ratio, was elevated in the tumors. Transient suppression observed previously in the clone was caused by injection of a high cell number (2 × 10(6)-5 × 10(6)). METCAM/MUC18 positively promotes tumorigenesis of SK-BR-3 cells by increasing the survival and proliferation pathway. Copyright © 2016. Published by Elsevier B.V.

Epigenetic regulation of multiple tumor-related genes leads to suppression of breast tumorigenesis by dietary genistein.

PubMed

Li, Yuanyuan; Chen, Huaping; Hardy, Tabitha M; Tollefsbol, Trygve O

2013-01-01

Breast cancer is one of the most lethal diseases in women; however, the precise etiological factors are still not clear. Genistein (GE), a natural isoflavone found in soybean products, is believed to be a potent chemopreventive agent for breast cancer. One of the most important mechanisms for GE inhibition of breast cancer may involve its potential in impacting epigenetic processes allowing reversal of aberrant epigenetic events during breast tumorigenesis. To investigate epigenetic regulation for GE impedance of breast tumorigenesis, we monitored epigenetic alterations of several key tumor-related genes in an established breast cancer transformation system. Our results show that GE significantly inhibited cell growth in a dose-dependent manner in precancerous breast cells and breast cancer cells, whereas it exhibited little effect on normal human mammary epithelial cells. Furthermore, GE treatment increased expression of two crucial tumor suppressor genes, p21(WAF1) (p21) and p16(INK4a) (p16), although it decreased expression of two tumor promoting genes, BMI1 and c-MYC. GE treatment led to alterations of histone modifications in the promoters of p21 and p16 as well as the binding ability of the c-MYC-BMI1 complex to the p16 promoter contributing to GE-induced epigenetic activation of these tumor suppressor genes. In addition, an orally-fed GE diet prevented breast tumorigenesis and inhibited breast cancer development in breast cancer mice xenografts. Our results suggest that genistein may repress early breast tumorigenesis by epigenetic regulation of p21 and p16 by impacting histone modifications as well as the BMI1-c-MYC complex recruitment to the regulatory region in the promoters of these genes. These studies will facilitate more effective use of soybean product in breast cancer prevention and also help elucidate the mechanisms during the process of early breast tumorigenesis.

Ghrelin administration suppresses inflammation-associated colorectal carcinogenesis in mice

PubMed Central

Kawaguchi, Makiko; Kanemaru, Ai; Fukushima, Tsuyoshi; Yamamoto, Koji; Tanaka, Hiroyuki; Haruyama, Yukihiro; Itoh, Hiroshi; Matsumoto, Nobuhiro; Kangawa, Kenji; Nakazato, Masamitsu; Kataoka, Hiroaki

2015-01-01

Ghrelin is a 28-amino-acid peptide that stimulates the release of pituitary growth hormone. Because of its orexigenic effects, ghrelin is being developed as a therapeutic option for postoperative support and treatment of anorexia-cachexia syndrome of cancer patients. However, ghrelin has a multiplicity of physiological functions, and it also affects cell proliferation. Therefore, the effects of ghrelin administration on carcinogenesis and cancer progression in patients susceptible to cancer should be clarified. In this study, we examined the effects of ghrelin on cancer promotion in vivo using murine intestinal carcinogenesis models. Intestinal tumorigenesis was examined to determine the effects of either exogenous ghrelin administration or ghrelin deficiency following deletion of the Ghrl gene. Two murine intestinal tumorigenesis models were used. The first was the azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced inflammation-associated colon carcinogenesis model and the second was the ApcMin/+ genetic cancer susceptibility model. In AOM/DSS-treated mice, administration of ghrelin significantly suppressed tumor formation in the colon. In contrast, ghrelin administration did not affect the number of intestinal tumors formed in ApcMin/+ mice. The absence of endogenous ghrelin did not affect the incidence of intestinal tumors in either AOM/DSS-treated mice or ApcMin/+ mice, though tumor size tended to be larger in Ghrl−/− colons in the AOM/DSS model. No tumor-promoting effect was observed by ghrelin administration in either tumorigenesis model. In summary, this study provides in vivo experimental evidence for the usefulness of ghrelin administration in the chemoprevention of inflammation-associated colorectal carcinogenesis and may suggest its safety in patients under colitis-associated cancer susceptibility conditions. PMID:26094822

Loss of Dickkopf 3 Promotes the Tumorigenesis of Basal Breast Cancer

PubMed Central

Lorsy, Eva; Topuz, Aylin Sophie; Geisler, Cordelia; Stahl, Sarah; Garczyk, Stefan; von Stillfried, Saskia; Hoss, Mareike; Gluz, Oleg; Hartmann, Arndt; Knüchel, Ruth; Dahl, Edgar

2016-01-01

Dickkopf 3 (DKK3) has been associated with tumor suppression of various tumor entities including breast cancer. However, the functional impact of DKK3 on the tumorigenesis of distinct molecular breast cancer subtypes has not been considered so far. Therefore, we initiated a study analyzing the subtype-specific DKK3 expression pattern as well as its prognostic and functional impact with respect to breast cancer subtypes. Based on three independent tissue cohorts including one in silico dataset (n = 30, n = 463 and n = 791) we observed a clear down-regulation of DKK3 expression in breast cancer samples compared to healthy breast tissue controls on mRNA and protein level. Interestingly, most abundant reduction of DKK3 expression was detected in the highly aggressive basal breast cancer subtype. Analyzing a large in silico dataset comprising 3,554 cases showed that low DKK3 mRNA expression was significantly associated with reduced recurrence free survival (RFS) of luminal and basal-like breast cancer cases. Functionally, DKK3 re-expression in human breast cancer cell lines led to suppression of cell growth possibly mediated by up-regulation of apoptosis in basal-like but not in luminal-like breast cancer cell lines. Moreover, ectopic DKK3 expression in mesenchymal basal breast cancer cells resulted in partial restoration of epithelial cell morphology which was molecularly supported by higher expression of epithelial markers like E-Cadherin and down-regulation of mesenchymal markers such as Snail 1. Hence, we provide evidence that down-regulation of DKK3 especially promotes tumorigenesis of the aggressive basal breast cancer subtype. Further studies decoding the underlying molecular mechanisms of DKK3-mediated effects may help to identify novel targeted therapies for this clinically highly relevant breast cancer subtype. PMID:27467270

Proliferating cell nuclear antigen promotes cell proliferation and tumorigenesis by up-regulating STAT3 in non-small cell lung cancer.

PubMed

Wang, Liuxin; Kong, Weixiang; Liu, Bing; Zhang, Xueqing

2018-08-01

Proliferating cell nuclear antigen (PCNA) functions as a bridging molecule, which targets proteins that have distinct roles in cell growth. The expression of PCNA is dysregulated in some tumors and takes part in the progression of oncogenesis. However, the roles of PCNA in the progression of non-small cell lung cancer (NSCLC) remain unknown. The present study aimed to investigate the function of PCNA in the occurrence and development of NSCLC and its underlying molecular mechanisms. Western blotting, RT-PCR, and immunohistochemistry assays were used to detect the expression pattern of PCNA in NSCLC tissues and cells. A log rank test was performed to compare the overall survival (OS) of patients with high/low expression of PCNA. Besides, the relationship between PCNA and signal transducer and activator of transcription-3 (STAT3) proteins were evaluated. Then, MTT, flow cytometry, clonal formation, and in vivo xenograft assays were conducted to investigate the effects of PCNA/STAT3 on cell growth, clonal formation, apoptosis, and tumorigenesis. Results showed that PCNA expression was elevated in NSCLC tissues and cells and it could combine with STAT3 and increased its expression and phosphorylation. Moreover, the expression of PCNA showed a positive correlation with the TNM grade and occurrence rate of the lymphatic metastasis and poor prognosis of NSCLC patients. Overexpression of PCNA promoted cell proliferation, clonal formation, and tumorigenesis in lung cancer cells and inhibited cell apoptosis. In contrast, these effects were inhibited when knockdown of STAT3. In conclusion, this study demonstrates that PCNA functions as an oncogene in the progression of NSCLC through up-regulation of STAT3. These findings point to a potentially new therapeutic strategy for NSCLC. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

The Role of Crk Adaptor Proteins in Breast Tumorigenesis and Bone Metastasis

DTIC Science & Technology

2012-09-01

purchased from Asterand (Detroit, MI, USA) in 2009 and cultured as in [17] from freeze downs from 2009. Both cell lines under- went standard mouse antibody ...directed muta- genesis using the QuickChange Multi Site-Directed Mutagenesis Kit from Stratagene (La Jolla, CA, USA). Antibodies included: CrkI/II...Ki67, CrkI/II, CrkII or CrkL specific antibodies in high (Grade 3) and low (Grade 1) grade tumors. Images taken using ImageScope; scale bar

Mechanisms for pituitary tumorigenesis: the plastic pituitary

PubMed Central

Melmed, Shlomo

2003-01-01

The anterior pituitary gland integrates the repertoire of hormonal signals controlling thyroid, adrenal, reproductive, and growth functions. The gland responds to complex central and peripheral signals by trophic hormone secretion and by undergoing reversible plastic changes in cell growth leading to hyperplasia, involution, or benign adenomas arising from functional pituitary cells. Discussed herein are the mechanisms underlying hereditary pituitary hypoplasia, reversible pituitary hyperplasia, excess hormone production, and tumor initiation and promotion associated with normal and abnormal pituitary differentiation in health and disease. PMID:14660734

Proteinase-Activated Receptor 2 May Drive Cancer Progression by Facilitating TGF-β Signaling.

PubMed

Ungefroren, Hendrik; Witte, David; Rauch, Bernhard H; Settmacher, Utz; Lehnert, Hendrik; Gieseler, Frank; Kaufmann, Roland

2017-11-22

The G protein-coupled receptor proteinase-activated receptor 2 (PAR2) has been implicated in various aspects of cellular physiology including inflammation, obesity and cancer. In cancer, it usually acts as a driver of cancer progression in various tumor types by promoting invasion and metastasis in response to activation by serine proteinases. Recently, we discovered another mode through which PAR2 may enhance tumorigenesis: crosstalk with transforming growth factor-β (TGF-β) signaling to promote TGF-β1-induced cell migration/invasion and invasion-associated gene expression in ductal pancreatic adenocarcinoma (PDAC) cells. In this chapter, we review what is known about the cellular TGF-β responses and signaling pathways affected by PAR2 expression, the signaling activities of PAR2 required for promoting TGF-β signaling, and the potential molecular mechanism(s) that underlie(s) the TGF-β signaling-promoting effect. Since PAR2 is activated through various serine proteinases and biased agonists, it may couple TGF-β signaling to a diverse range of other physiological processes that may or may not predispose cells to cancer development such as local inflammation, systemic coagulation and pathogen infection.

Proteinase-Activated Receptor 2 May Drive Cancer Progression by Facilitating TGF-β Signaling

PubMed Central

Ungefroren, Hendrik; Witte, David; Settmacher, Utz; Lehnert, Hendrik; Kaufmann, Roland

2017-01-01

The G protein-coupled receptor proteinase-activated receptor 2 (PAR2) has been implicated in various aspects of cellular physiology including inflammation, obesity and cancer. In cancer, it usually acts as a driver of cancer progression in various tumor types by promoting invasion and metastasis in response to activation by serine proteinases. Recently, we discovered another mode through which PAR2 may enhance tumorigenesis: crosstalk with transforming growth factor-β (TGF-β) signaling to promote TGF-β1-induced cell migration/invasion and invasion-associated gene expression in ductal pancreatic adenocarcinoma (PDAC) cells. In this chapter, we review what is known about the cellular TGF-β responses and signaling pathways affected by PAR2 expression, the signaling activities of PAR2 required for promoting TGF-β signaling, and the potential molecular mechanism(s) that underlie(s) the TGF-β signaling–promoting effect. Since PAR2 is activated through various serine proteinases and biased agonists, it may couple TGF-β signaling to a diverse range of other physiological processes that may or may not predispose cells to cancer development such as local inflammation, systemic coagulation and pathogen infection. PMID:29165389

Resistant starch prevents tumorigenesis of dimethylhydrazine-induced colon tumors via regulation of an ER stress-mediated mitochondrial apoptosis pathway.

PubMed

Wang, Qiuyu; Wang, Peng; Xiao, Zhigang

2018-04-01

Resistant starch is as common soluble fiber that escapes digestion in the small intestine and can regulate intestinal function, metabolism of blood glucose and lipids, and may prevent tumorigenesis of gastrointestinal cancer. Epidemiology and other evidence have suggested that resistant starch may prevent colon cancer development. The aim of the current study was to explore the ameliorative effects and potential mechanisms of resistant starch in the tumorigenesis of colon tumors induced by dimethylhydrazine in C57BL/6 mice. Western blot analysis, ELISA, microscopy, immunofluorescence and immunohistochemistry were used to analyze the efficacy of resistant starch on the metabolic balance in the colon and tumorigenesis of colon tumors. The results demonstrated that a diet containing resistant starch decreased the animal body weight and reduced free ammonia, pH and short chain fatty acids in feces compared with mice that received a standard diet. Resistant starch reduced the incidence of colon tumors and suppressed the expression of carcinogenesis‑associated proteins, including heat shock protein 25, protein kinase C‑d and gastrointestinal glutathione peroxidase in colon epithelial cells compared with standard starch and control groups. Colon tumor cells proliferation and dedifferentiation were significantly decreased by a resistant starch diet. The results also demonstrated that resistant starch increased the apoptosis of colon tumor cells through regulation of apoptosis‑associated gene expression levels in colon tumor cells. Oxidative stress and endoplasmic reticulum stress were upregulated, and elevation eukaryotic translation initiation factor 2α (eIF2α), activating transcription factor‑4 and secretase‑β expression levels were increased in the resistant starch diet group. Additionally, the activity of eIF2α and PERK were increased in colon tumor cells from mice that had received resistant starch. Increasing DNA damage‑inducible transcript 3 protein (CHOP), binding immunoglobulin protein (BIP) and caspase‑12 expression levels upregulated by resistant starch diet may contribute to the resistant starch‑induced apoptosis of colon tumor cells induced by 1,2‑dimethylhydrazine. In vitro assays demonstrated that knockdown of eIF2α inhibited apoptosis of colon tumor cells isolated from mice fed with resistant starch, which also downregulated CHOP, BIP and caspase‑3 expression levels compared with controls. Furthermore, long‑term survival of experimental mice was prolonged by the resistant starch diet compared with the standard diet group. In conclusion, the results indicate that resistant starch in the diet may prevent carcinogenesis of colon epithelial cells, mediated by enhancing apoptosis through an endoplasmic reticulum stress‑mediated mitochondrial apoptosis pathway.

Non-Targeted Effects and the Dose Response for Heavy Ion Tumorigenesis

NASA Technical Reports Server (NTRS)

Chappell, Lori J.; Cucinotta, Francis A.

2010-01-01

There is no human epidemiology data available to estimate the heavy ion cancer risks experienced by astronauts in space. Studies of tumor induction in mice are a necessary step to estimate risks to astronauts. Previous experimental data can be better utilized to model dose response for heavy ion tumorigenesis and plan future low dose studies.

Dietary supplementation with methylseleninic acid inhibits mammary tumorigenesis and metastasis in male MMTV-PyMT mice

USDA-ARS?s Scientific Manuscript database

Male breast cancer, which makes up approximately 1% of all breast cancer, is an aggressive disease with poor prognosis. We investigated the effects of dietary supplementation with selenium in the form of methylseleninic acid (MSeA, 4.0 mg MSeA/kg) on mammary tumorigenesis in male MMTV-PyMT mice. ...

Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development and Tumorigenesis

DTIC Science & Technology

2009-10-01

AD_________________ Award Number: W81XWH-06-1-0763 TITLE: Role of Fibroblast Growth Factor ...2009 4. TITLE AND SUBTITLE Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development 5a. CONTRACT NUMBER and Tumorigenesis...Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS Fibroblast Growth Factor Binding Protein-1

SOX2 plays a critical role in EGFR-mediated self-renewal of human prostate cancer stem-like cells.

PubMed

Rybak, Adrian P; Tang, Damu

2013-12-01

SOX2 is an essential transcription factor for stem cells and plays a role in tumorigenesis, however its role in prostate cancer stem cells (PCSCs) remains unclear. We report here a significant upregulation of SOX2 at both mRNA and protein levels in DU145 PCSCs propagated as suspension spheres in vitro. The expression of SOX2 in DU145 PCSCs is positively regulated by epidermal growth factor receptor (EGFR) signaling. Activation of EGFR signaling, following the addition of epidermal growth factor (EGF) or ectopic expression of a constitutively-active EGFR mutant (EGFRvIII), increased SOX2 expression and the self-renewal of DU145 PCSCs. Conversely, a small molecule EGFR inhibitor (AG1478) blocked EGFR activation, reduced SOX2 expression and inhibited PCSC self-renewal activity, implicating SOX2 in mediating EGFR-dependent self-renewal of PCSCs. In line with this notion, ectopic SOX2 expression enhanced EGF-induced self-renewal of DU145 PCSCs, while SOX2 knockdown reduced PCSC self-renewal with EGF treatment no longer capable of enhancing their propagation. Furthermore, SOX2 knockdown reduced the capacity of DU145 PCSCs to grow under anchorage-independent conditions. Finally, DU145 PCSCs generated xenograft tumors more aggressively with elevated levels of SOX2 expression compared to xenograft tumors derived from non-PCSCs. Collectively, we provide evidence that SOX2 plays a critical role in EGFR-mediated self-renewal of DU145 PCSCs. © 2013.

Elevation of β-galactoside α2,6-sialyltransferase 1 in a fructose-responsive manner promotes pancreatic cancer metastasis

PubMed Central

Hsieh, Chi-Che; Shyr, Yi-Ming; Liao, Wen-Ying; Chen, Tien-Hua; Wang, Shin-E; Lu, Peir-Chuen; Lin, Pei-Yu; Chen, Yan-Bo; Mao, Wan-Yu; Han, Hsin-Ying; Hsiao, Michael; Yang, Wen-Bin; Li, Wen-Shan; Sher, Yuh-Pyng; Shen, Chia-Ning

2017-01-01

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of pancreatic cancer with clinical characteristics of local invasion and early metastasis. Recent cohort studies indicate high fructose intake is associated with an increase in pancreatic cancer risk. However, the mechanisms by which fructose promotes pancreatic tumorigenesis remain unclear. Herein, Kras+/LSLG12D mice were crossed with Elas-CreER transgenic mice to determine whether fructose intake directly contributes to tumor formation. Orthotopic tumor-xenograft experiments were performed to determine whether fructose substitution enhances the metastatic potential of PDAC cells. The mechanisms underlying the effects of fructose were explored by RNAseq analysis in combination with high-performance anion exchange chromatography. Dietary fructose was initially found to promote the development of aggressive pancreatic cancer in mice conditionally expressing KrasG12D in the adult pancreas. We further revealed that fructose substitution enhanced the metastatic potential of human PDAC cell via selective outgrowth of aggressive ABCG2-positive subpopulations and elevating N-acetylmannosamine levels that upregulated β-galactoside α2,6-sialyltransferase 1 (ST6Gal1), thereby promoting distant metastasis. Finally, we observed that PDAC patients expressing higher levels of ST6Gal1 and GLUT5 presented poorer prognosis compared to other groups. In conclusion, our findings have elucidated a crucial role of ST6Gal1 in regulating the invasiveness of PDACs in a fructose-responsive manner. PMID:28032597

The possible mechanism of enhanced carcinogenesis induced by genotoxic carcinogens in rasH2 mice.

PubMed

Okamura, Miwa; Unami, Akira; Moto, Mitsuyoshi; Muguruma, Masako; Ito, Tadashi; Jin, Meilan; Oishi, Yuji; Kashida, Yoko; Mitsumori, Kunitoshi

2007-01-08

Microarray and RT-PCR analyses were performed for the transgene and Ras-related genes in forestomach squamous cell carcinomas (SCCs) induced by 7,12-dimethylbenz[a]anthracene (DMBA) in rasH2 mice; these results were compared with our previous molecular data of N-ethyl-N-nitrosourea-induced forestomach SCCs and urethane-induced lung adenomas in rasH2 mice. Overexpression of the transgene was detected in the DMBA-induced SCCs, suggesting that the transgene plays an important role in enhanced carcinogenesis in rasH2 mice. In addition, the mouse endogenous ras genes were up-regulated in the DMBA-induced SCCs, and are probably involved in the tumorigenesis of forestomach SCCs. Genes such as osteopontin, Cks1b, Tpm1, Reck, gelsolin, and amphiregulin that were commonly altered in these three different carcinogen-induced tumors may contribute to the development of tumors in rasH2 mice.

Development of Membrane-Bound GM-CSF and IL-18 as an Effective Tumor Vaccine

PubMed Central

Cheng, Ta-Chun; Chuang, Chih-Hung; Kao, Chien-Han; Hsieh, Yuan-Chin; Cheng, Kuang-Hung; Wang, Jaw-Yuan; Cheng, Chiu-Min; Chen, Chien-Shu; Cheng, Tian-Lu

2015-01-01

The development of effective adjuvant is the key factor to boost the immunogenicity of tumor cells as a tumor vaccine. In this study, we expressed membrane-bound granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-18 (IL-18) as adjuvants in tumor cells to stimulate immune response. B7 transmembrane domain fused GM-CSF and IL-18 was successfully expressed in the cell membrane and stimulated mouse splenocyte proliferation. Co-expression of GM-CSF and IL-18 reduced tumorigenesis (P<0.05) and enhanced tumor protective efficacy (P<0.05) significantly in comparison with GM-CSF alone. These results indicated that the combination of GM-CSF andIL-18 will enhance the immunogenicity of a cell-based anti-tumor vaccine. This membrane-bound approach can be applied to other cytokines for the development of novel vaccine strategies. PMID:26186692

The MutSβ complex is a modulator of p53-driven tumorigenesis through its functions in both DNA double strand break repair and mismatch repair

PubMed Central

van Oers, Johanna M. M.; Edwards, Yasmin; Chahwan, Richard; Zhang, Weijia; Smith, Cameron; Pechuan, Joaquín; Schaetzlein, Sonja; Jin, Bo; Wang, Yuxun; Bergman, Aviv; Scharff, Matthew D.; Edelmann, Winfried

2014-01-01

Loss of the DNA mismatch repair protein MSH3 leads to the development of a variety of tumors in mice without significantly affecting survival rates, suggesting a modulating role for the MutSβ (MSH2-MSH3) complex in late onset tumorigenesis. To better study the role of MSH3 in tumor progression, we crossed Msh3−/− mice onto a tumor predisposing p53-deficient background. Survival of Msh3/p53 mice was not reduced compared to single p53 mutant mice; however, the tumor spectrum changed significantly from lymphoma to sarcoma, indicating MSH3 as a potent modulator of p53-driven tumorigenesis. Interestingly, Msh3−/− mouse embryonic fibroblasts displayed increased chromatid breaks and persistence of γH2AX foci following ionizing radiation, indicating a defect in DNA double strand break repair. Msh3/p53 tumors showed increased loss of heterozygosity, elevated genome-wide copy number variation, and a moderate microsatellite instability phenotype compared to Msh2/p53 tumors, revealing that MSH2-MSH3 suppresses tumorigenesis by maintaining chromosomal stability. Our results show that the MSH2-MSH3 complex is important for the suppression of late onset tumors due to its role in DNA double strand break repair as well as in DNA mismatch repair. Furthermore, they demonstrate that MSH2-MSH3 suppresses chromosomal instability and modulates the tumor spectrum in p53-deficient tumorigenesis, and possibly plays a role in other chromosomally unstable tumors as well. PMID:24013230

The MutSβ complex is a modulator of p53-driven tumorigenesis through its functions in both DNA double-strand break repair and mismatch repair.

PubMed

van Oers, J M M; Edwards, Y; Chahwan, R; Zhang, W; Smith, C; Pechuan, X; Schaetzlein, S; Jin, B; Wang, Y; Bergman, A; Scharff, M D; Edelmann, W

2014-07-24

Loss of the DNA mismatch repair (MMR) protein MSH3 leads to the development of a variety of tumors in mice without significantly affecting survival rates, suggesting a modulating role for the MutSβ (MSH2-MSH3) complex in late-onset tumorigenesis. To better study the role of MSH3 in tumor progression, we crossed Msh3(-/-) mice onto a tumor predisposing p53-deficient background. Survival of Msh3/p53 mice was not reduced compared with p53 single mutant mice; however, the tumor spectrum changed significantly from lymphoma to sarcoma, indicating MSH3 as a potent modulator of p53-driven tumorigenesis. Interestingly, Msh3(-/-) mouse embryonic fibroblasts displayed increased chromatid breaks and persistence of γH2AX foci following ionizing radiation, indicating a defect in DNA double-strand break repair (DSBR). Msh3/p53 tumors showed increased loss of heterozygosity, elevated genome-wide copy-number variation and a moderate microsatellite instability phenotype compared with Msh2/p53 tumors, revealing that MSH2-MSH3 suppresses tumorigenesis by maintaining chromosomal stability. Our results show that the MSH2-MSH3 complex is important for the suppression of late-onset tumors due to its roles in DNA DSBR as well as in DNA MMR. Further, they demonstrate that MSH2-MSH3 suppresses chromosomal instability and modulates the tumor spectrum in p53-deficient tumorigenesis and possibly has a role in other chromosomally unstable tumors as well.

Functional characterization of Anaphase Promoting Complex/Cyclosome (APC/C) E3 ubiquitin ligases in tumorigenesis

PubMed Central

Zhang, Jinfang; Wan, Lixin; Dai, Xiangpeng; Sun, Yi; Wei, Wenyi

2014-01-01

The Anaphase Promoting Complex/Cyclosome (APC/C) is a multi-subunit E3 ubiquitin ligase that primarily governs cell cycle progression. APC/C is composed of at least 14 core subunits and recruits its substrates for ubiquitination via one of the two adaptor proteins, Cdc20 or Cdh1, in M or M/early G1 phase, respectively. Furthermore, recent studies have shed light on crucial functions for APC/C in maintaining genomic integrity, neuronal differentiation, cellular metabolism and tumorigenesis. To gain better insight into the in vivo physiological functions of APC/C in regulating various cellular processes, particularly development and tumorigenesis, a number of mouse models of APC/C core subunits, coactivators or inhibitors have been established and characterized. However, due to their essential role in cell cycle regulation, most of the germline knockout mice targeting the APC/C pathway are embryonic lethal, indicating the need for generating conditional knockout mouse models to assess the role in tumorigenesis for each APC/C signaling component in specific tissues. In this review, we will first provide a brief introduction of the ubiquitin-proteasome system (UPS) and the biochemical activities and cellular functions of the APC/C E3 ligase. We will then focus primarily on characterizing genetic mouse models used to understand the physiological roles of each APC/C signaling component in embryogenesis, cell proliferation, development and carcinogenesis. Finally, we discuss future research directions to further elucidate the physiological contributions of APC/C components during tumorigenesis and validate their potentials as a novel class of anti-cancer targets. PMID:24569229

Combination of PI3K/Akt/mTOR inhibitors and PDT in endothelial and tumor cells

NASA Astrophysics Data System (ADS)

Fateye, Babasola; Chen, Bin

2011-02-01

The PI3/Akt/mTOR kinase signaling pathway is a major signaling pathway in eukaryotic cells, and dysregulation of this signaling pathway has been implicated in tumorigenesis and malignancy in several cancers including prostate cancer. We assessed the effects of combination PI3K pathway inhibition on the efficacy of PDT in human prostate tumor cell line (PC3) and SV40-transformed mouse endothelial cell line (SVEC-40). Combination of PDT and BEZ 235 (BEZ), a pan-PI3/ mTOR kinase inhibitor additively enhanced efficacy of sub-lethal PDT in both cell lines. The combination of the pan-PI3/ mTOR kinase inhibitor LY294002 (LY) with PDT also enhanced efficacy of PDT in PC3 in an additive manner but synergistically in SVEC. In order to determine the mechanism of enhancement of efficacy, we assessed apoptosis and autophagy following PDT. PDT-mediated apoptosis was enhanced in endothelial cells, by both BEZ and LY rapidly after treatment. Compared to SVEC, PC3 cells are apoptosis-deficient and apoptosis was not significantly enhanced by either LY or BEZ. However, lethal PDT of PC3 cells induced a delayed autophagic response which may be enhanced by combination, depending on PI3K inhibitor and dose.

Promoter methylation in head and neck tumorigenesis.

PubMed

Stephen, Josena K; Chen, Kang Mei; Havard, Shaleta; Harris, Glynis; Worsham, Maria J

2012-01-01

In addition to genetic alterations of gains and losses, epigenetic events of promoter methylation appear to further undermine a destabilized genomic repertoire in squamous head and neck carcinoma (HNSCC). This chapter provides an overview of frequently methylated tumor suppressor genes in benign head and neck papillomas, primary HNSCC tumors, and HNSCC cell lines and their relevance as epigenetic markers in head and neck tumorigenesis.

STAT signaling in mammary gland differentiation, cell survival and tumorigenesis

PubMed Central

Haricharan, S; Li, Y

2013-01-01

The mammary gland is a unique organ that undergoes extensive and profound changes during puberty, menstruation, pregnancy, lactation and involution. The changes that take place during puberty involve large-scale proliferation and invasion of the fat-pad. During pregnancy and lactation, the mammary cells are exposed to signaling pathways that inhibit apoptosis, induce proliferation and invoke terminal differentiation. Finally, during involution the mammary gland is exposed to milk stasis, programed cell death and stromal reorganization to clear the differentiated milk-producing cells. Not surprisingly, the signaling pathways responsible for bringing about these changes in breast cells are often subverted during the process of tumorigenesis. The STAT family of proteins is involved in every stage of mammary gland development, and is also frequently implicated in breast tumorigenesis. While the roles of STAT3 and STAT5 during mammary gland development and tumorigenesis are well studied, others members, e.g. STAT1 and STAT6, have only recently been observed to play a role in mammary gland biology. Continued investigation into the STAT protein network in the mammary gland will likely yield new biomarkers and risk factors for breast cancer, and may also lead to novel prophylactic or therapeutic strategies against breast cancer. PMID:23541951

HIP1: trafficking roles and regulation of tumorigenesis.

PubMed

Hyun, Teresa S; Ross, Theodora S

2004-04-01

During recent years, alterations in proteins of the endocytic pathway have been associated with tumors. Disrupted regulation of the endocytic pathway is a relatively unstudied mechanism of tumorigenesis, which can concomitantly disrupt several different signaling pathways to affect growth, differentiation and survival. Several endocytic proteins have been identified, either as part of tumor-associated translocations or to have the ability to transform cells. Here, we summarize the information known about huntingtin interacting protein 1 (HIP1), an endocytic protein with transforming properties that is involved in a cancer-causing translocation and which is overexpressed in a variety of human cancers. We describe the known normal functions of HIP1 in endocytosis and receptor trafficking, the evidence for its role as an oncoprotein and how HIP1 might be altered to promote tumorigenesis.

Uveal melanoma hepatic metastases mutation spectrum analysis using targeted next-generation sequencing of 400 cancer genes.

PubMed

Luscan, A; Just, P A; Briand, A; Burin des Roziers, C; Goussard, P; Nitschké, P; Vidaud, M; Avril, M F; Terris, B; Pasmant, E

2015-04-01

Uveal melanoma (UM) is the most common malignant tumour of the eye. Diagnosis often occurs late in the course of disease, and prognosis is generally poor. Recently, recurrent somatic mutations were described, unravelling additional specific altered pathways in UM. Targeted next-generation sequencing (NGS) can now be applied to an accurate and fast identification of somatic mutations in cancer. The aim of the present study was to characterise the mutation pattern of five UM hepatic metastases with well-defined clinical and pathological features. We analysed the UM mutation spectrum using targeted NGS on 409 cancer genes. Four previous reported genes were found to be recurrently mutated. All tumours presented mutually exclusive GNA11 or GNAQ missense mutations. BAP1 loss-of-function mutations were found in three UMs. SF3B1 missense mutations were found in the two UMs with no BAP1 mutations. We then searched for additional mutation targets. We identified the Arg505Cys mutation in the tumour suppressor FBXW7. The same mutation was previously described in different cancer types, and FBXW7 was recently reported to be mutated in UM exomes. Further studies are required to confirm FBXW7 implication in UM tumorigenesis. Elucidating the molecular mechanisms underlying UM tumorigenesis holds the promise for novel and effective targeted UM therapies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

MINA controls proliferation and tumorigenesis of glioblastoma by epigenetically regulating cyclins and CDKs via H3K9me3 demethylation.

PubMed

Huang, M-Y; Xuan, F; Liu, W; Cui, H-J

2017-01-19

It is generally known that histone demethylases regulate gene transcription by altering the methylate status on histones, but their roles in cancers and the underlying molecular mechanisms still remain unclear. MYC-induced nuclear antigen (MINA) is reported to be a histone demethylase and highly expressed in many cancers. Here, for the first time, we show that MINA is involved in glioblastoma carcinogenesis and reveal the probable mechanisms of it in cell-cycle control. Kaplan-Meier analysis of progression-free survival showed that high MINA expression was strongly correlated with poor outcome and advancing tumor stage. MINA knockdown significantly repressed the cell proliferation and tumorigenesis abilities of glioblastoma cells in vitro and in vivo that were rescued by overexpressing the full-length MINA afterwards. Microarray analysis after knockdown of MINA revealed that MINA probably regulated glioblastoma carcinogenesis through the predominant cell-cycle pathways. Further investigation showed that MINA deficiency led to a cell-cycle arrest in G1 and G2 phases. And among the downstream genes, we found that cyclins and cyclin-dependent kinases were directly activated by MINA via the demethylation of H3K9me3.

Disruptive chemicals, senescence and immortality

PubMed Central

Carnero, Amancio; Blanco-Aparicio, Carmen; Kondoh, Hiroshi; Lleonart, Matilde E.; Martinez-Leal, Juan Fernando; Mondello, Chiara; Ivana Scovassi, A.; Bisson, William H.; Amedei, Amedeo; Roy, Rabindra; Woodrick, Jordan; Colacci, Annamaria; Vaccari, Monica; Raju, Jayadev; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Salem, Hosni K.; Memeo, Lorenzo; Forte, Stefano; Singh, Neetu; Hamid, Roslida A.; Ryan, Elizabeth P.; Brown, Dustin G.; Wise, John Pierce; Wise, Sandra S.; Yasaei, Hemad

2015-01-01

Carcinogenesis is thought to be a multistep process, with clonal evolution playing a central role in the process. Clonal evolution involves the repeated ‘selection and succession’ of rare variant cells that acquire a growth advantage over the remaining cell population through the acquisition of ‘driver mutations’ enabling a selective advantage in a particular micro-environment. Clonal selection is the driving force behind tumorigenesis and possesses three basic requirements: (i) effective competitive proliferation of the variant clone when compared with its neighboring cells, (ii) acquisition of an indefinite capacity for self-renewal, and (iii) establishment of sufficiently high levels of genetic and epigenetic variability to permit the emergence of rare variants. However, several questions regarding the process of clonal evolution remain. Which cellular processes initiate carcinogenesis in the first place? To what extent are environmental carcinogens responsible for the initiation of clonal evolution? What are the roles of genotoxic and non-genotoxic carcinogens in carcinogenesis? What are the underlying mechanisms responsible for chemical carcinogen-induced cellular immortality? Here, we explore the possible mechanisms of cellular immortalization, the contribution of immortalization to tumorigenesis and the mechanisms by which chemical carcinogens may contribute to these processes. PMID:26106138

Exome capture sequencing reveals new insights into hepatitis B virus-induced hepatocellular carcinoma at the early stage of tumorigenesis.

PubMed

Chen, Yong; Wang, Lijuan; Xu, Hexiang; Liu, Xingxiang; Zhao, Yingren

2013-10-01

Hepatocellular carcinoma (HCC), the most common type of liver cancer, is the third primary cause of cancer-related mortality worldwide. The molecular mechanisms underlying the initiation and formation of HCC remain obscure. In the present study, we performed exome sequencing using tumor and normal tissues from 3 hepatitis B virus (HBV)-positive BCLC stage A HCC patients. Bioinformatic analysis was performed to find candidate protein-altering somatic mutations. Eighty damaging mutations were validated and 59 genes were reported to be mutated in HBV-related HCCs for the first time here. Further analysis using whole genome sequencing (WGS) data of 88 HBV-related HCC patients from the European Genome-phenome Archive database showed that mutations in 33 of the 59 genes were also detected in other samples. Variants of two newly found genes, ZNF717 and PARP4, were detected in more than 10% of the WGS samples. Several other genes, such as FLNA and CNTN2, are also noteworthy. Thus, the exome sequencing analysis of three BCLC stage A patients provides new insights into the molecular events governing the early steps of HBV-induced HCC tumorigenesis.

SMC1A recruits tumor-associated-fibroblasts (TAFs) and promotes colorectal cancer metastasis.

PubMed

Zhou, Pengyang; Xiao, Nan; Wang, Jian; Wang, Zhanhuai; Zheng, Shuchun; Shan, Siyang; Wang, Jianping; Du, Jinlin; Wang, Jianwei

2017-01-28

Tumor-associated-fibroblasts (TAFs) are the most important host cells in the stroma and take part in extracellular matrix construction and cancer colony development. During cancer colonization, seed cells from primary tumor can reconstruct the microenvironment by recruiting circulating cancer cells and TAFs to the metastasis site. Previous studies have established that SMC1A, a subunit of cohesin, is an important trigger signal for liver metastasis in colorectal cancer. We investigated the particular effects as well as the underlying mechanism of SMC1A on TAFs recruitment during liver metastasis of colorectal cancer. Here, We found that: first, the high expression of SMC1A in colorectal cancer cells promotes the invasiveness and the viability of these cells by recruiting circulating TAFs, facilitating early tumor construction and tumorigenesis; second, different expression levels of SMC1A influenced the reformation of fibroblasts, which assisted tumorigenesis, and third, expression of SMC1A stimulated the secretion of the inflammatory mediators of TNF-α and IL-1β, and up-regulated the transcriptional expression of MMP2 and VEGF-β, both of which were involved in the tumor-related gene pathway. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Downregulation of phosphoglycerate dehydrogenase inhibits proliferation and enhances cisplatin sensitivity in cervical adenocarcinoma cells by regulating Bcl-2 and caspase-3

PubMed Central

Jing, Zhang; Heng, Wei; Xia, Liu; Ning, Wang; Yafei, Qi; Yao, Zhang; Shulan, Zhang

2015-01-01

Phosphoglycerate dehydrogenase (PHGDH) is the key enzyme of de novo serine biosynthesis. Previous reports have demonstrated that PHGDH plays an important role in some malignancies. However, the biological role of PHGDH in human cervical adenocarcinoma has not been explored. We examined the expression of PHGDH in 54 cervical adenocarcinoma samples by immunohistochemistry and evaluated the association with clinicopathological parameters and prognosis. We performed shRNA transfection to knock down PHGDH gene expression in HeLa cells. A cell proliferation test, cisplatin cytotoxicity test and apoptosis test examined the HeLa cell line after PHGDH knockdown in vitro. In vivo tumorigenesis was assessed using a mouse xenograft model. Moreover, we examined the effects on Bcl-2 and cleaved caspase-3 expression after knockdown of PHGDH and treatment of cisplatin for 48h by Western blot. In this study, we demonstrated that elevated PHGDH expression was found in cervical adenocarcinoma and was associated with tumor size and prognosis. Knocking down PHGDH in HeLa cells significantly inhibited cell proliferation and increased cisplatin chemotherapy sensitivity. Silencing PHGDH resulted in inhibition of tumorigenesis in vivo. Furthermore, PHGDH knockdown reduced Bcl-2 and increased cleaved caspase-3 expression. Collectively, our study indicates the novel roles of PHGDH in cervical adenocarcinoma and identifies PHGDH as a new anticancer target. PMID:25719555

Radiation-induced chromosomal instability in BALB/c and C57BL/6 mice: the difference is as clear as black and white

NASA Technical Reports Server (NTRS)

Ponnaiya, B.; Cornforth, M. N.; Ullrich, R. L.

1997-01-01

Genomic instability has been proposed to be the earliest step in radiation-induced tumorigenesis. It follows from this hypothesis that individuals highly susceptible to induction of tumors by radiation should exhibit enhanced radiation-induced instability. BALB/c white mice are considerably more sensitive to radiation-induced mammary cancer than C57BL/6 black mice. In this study, primary mammary epithelial cell cultures from these two strains were examined for the "delayed" appearance of chromosomal aberrations after exposure to 137Cs gamma radiation, as a measure of radiation-induced genomic instability. As expected, actively dividing cultures from both strains showed a rapid decline of initial asymmetrical aberrations with time postirradiation. However, after 16 population doublings, cells from BALB/c mice exhibited a marked increase in the frequency of chromatid-type breaks and gaps which remained elevated throughout the time course of the experiment (28 doublings). No such effect was observed for the cells of C57BL/6 mice; after the rapid clearance of initial aberrations, the frequency of chromatid-type aberrations in the irradiated population remained at or near those of nonirradiated controls. These results demonstrate a correlation between the latent expression of chromosomal damage in vitro and susceptibility for mammary tumors, and provide further support for the central role of radiation-induced instability in the process of tumorigenesis.

PI3K Activation in Neural Stem Cells Drives Tumorigenesis which can be Ameliorated by Targeting the cAMP Response Element Binding (CREB) Protein.

PubMed

Daniel, Paul M; Filiz, Gulay; Brown, Daniel V; Christie, Michael; Waring, Paul M; Zhang, Yi; Haynes, John M; Pouton, Colin; Flanagan, Dustin; Vincan, Elizabeth; Johns, Terrance G; Montgomery, Karen; Phillips, Wayne A; Mantamadiotis, Theo

2018-04-30

Hyperactivation of PI3K signaling is common in cancers but the precise role of the pathway in glioma biology remains to be determined. Some understanding of PI3K signaling mechanisms in brain cancer comes from studies on neural stem/progenitor cells, where signals transmitted via the PI3K pathway cooperate with other intracellular pathways and downstream transcription factors to regulate critical cell functions. To investigate the role for the PI3K pathway in glioma initiation and development, we generated a mouse model targeting the inducible expression of a PIK3CAH1047A oncogenic mutant and deletion of the PI3K negative regulator, PTEN, to neural stem/progenitor cells (NSPCs). Expression of a Pik3caH1047A was sufficient to generate tumors with oligodendroglial features but simultaneous loss of PTEN was required for the development of invasive, high-grade glioma. Pik3caH1047A-PTEN mutant NSPCs exhibited enhanced neurosphere formation which correlated with increased WNT signaling, while loss of CREB in Pik3caH1047A-Pten mutant tumors led to longer symptom-free survival in mice. Taken together, our findings present a novel mouse model for glioma demonstrating that the PI3K pathway is important for initiation of tumorigenesis and that disruption of downstream CREB signaling attenuates tumor expansion.

Elevated O-GlcNAcylation promotes colonic inflammation and tumorigenesis by modulating NF-κB signaling.

PubMed

Yang, Yong Ryoul; Kim, Dae Hyun; Seo, Young-Kyo; Park, Dohyun; Jang, Hyun-Jun; Choi, Soo Youn; Lee, Yong Hwa; Lee, Gyun Hui; Nakajima, Kazuki; Taniguchi, Naoyuki; Kim, Jung-Min; Choi, Eun-Jeong; Moon, Hyo Youl; Kim, Il Shin; Choi, Jang Hyun; Lee, Ho; Ryu, Sung Ho; Cocco, Lucio; Suh, Pann-Ghill

2015-05-20

O-GlcNAcylation is a reversible post-translational modification. O-GlcNAc addition and removal is catalyzed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. More recent evidence indicates that regulation of O-GlcNAcylation is important for inflammatory diseases and tumorigenesis. In this study, we revealed that O-GlcNAcylation was increased in the colonic tissues of dextran sodium sulfate (DSS)-induced colitis and azoxymethane (AOM)/DSS-induced colitis-associated cancer (CAC) animal models. Moreover, the O-GlcNAcylation level was elevated in human CAC tissues compared with matched normal counterparts. To investigate the functional role of O-GlcNAcylation in colitis, we used OGA heterozygote mice, which have an increased level of O-GlcNAcylation. OGA(+/-) mice have higher susceptibility to DSS-induced colitis than OGA(+/+) mice. OGA(+/-) mice exhibited a higher incidence of colon tumors than OGA(+/+) mice. In molecular studies, elevated O-GlcNAc levels were shown to enhance the activation of NF-κB signaling through increasing the binding of RelA/p65 to its target promoters. We also found that Thr-322 and Thr352 in the p65-O-GlcNAcylation sites are critical for p65 promoter binding. These results suggest that the elevated O-GlcNAcylation level in colonic tissues contributes to the development of colitis and CAC by disrupting regulation of NF-κB-dependent transcriptional activity.

Heparanase cooperates with Ras to drive breast and skin tumorigenesis.

PubMed

Boyango, Ilanit; Barash, Uri; Naroditsky, Inna; Li, Jin-Ping; Hammond, Edward; Ilan, Neta; Vlodavsky, Israel

2014-08-15

Heparanase has been implicated in cancer but its contribution to the early stages of cancer development is uncertain. In this study, we utilized nontransformed human MCF10A mammary epithelial cells and two genetic mouse models [Hpa-transgenic (Hpa-Tg) and knockout mice] to explore heparanase function at early stages of tumor development. Heparanase overexpression resulted in significantly enlarged asymmetrical acinar structures, indicating increased cell proliferation and decreased organization. This phenotype was enhanced by coexpression of heparanase variants with a mutant H-Ras gene, which was sufficient to enable growth of invasive carcinoma in vivo. These observations were extended in vivo by comparing the response of Hpa-Tg mice to a classical two-stage 12-dimethylbenz(a)anthracene (DMBA)/12-o-tetradecanoylphorbol-13-acetate (TPA) protocol for skin carcinogenesis. Hpa-Tg mice overexpressing heparanase were far more sensitive than control mice to DMBA/TPA treatment, exhibiting a 10-fold increase in the number and size of tumor lesions. Conversely, DMBA/TPA-induced tumor formation was greatly attenuated in Hpa-KO mice lacking heparanase, pointing to a critical role of heparanase in skin tumorigenesis. In support of these observations, the heparanase inhibitor PG545 potently suppressed tumor progression in this model system. Taken together, our findings establish that heparanase exerts protumorigenic properties at early stages of tumor initiation, cooperating with Ras to dramatically promote malignant development. ©2014 American Association for Cancer Research.

The Role of Nuclear Receptor Coactivator A1B1 in Growth Factor-Mediated Mammary Tumorigenesis

DTIC Science & Technology

2007-03-01

study display dwarfism and the retardation of mammary gland growth [9]. At the 4-month time point, I similarly observed an overall decrease in mammary...Coactivator A1B1 in Growth Factor- Mediated Mammary Tumorigenesis PRINCIPAL INVESTIGATOR: Mark P Fereshteh (BS) CONTRACTING ORGANIZATION...U.S. Army Medical Research and Materiel Command Fort Detrick, Maryland 21702-5012 DISTRIBUTION

Chemical Characterization and Toxicologic Evaluation of Airborne Mixtures. Tumorigenicity Studies of Diesel Fuel-2, Red Smoke Dye and Violet Smoke Dyes in the SENCAR Mouse Skin Tumorigenesis Bioassay System

DTIC Science & Technology

1985-09-01

11, 4. TITLE (and Subtitle) Chemical Characterization and Toxi - S. TYPE OF REPORT & PERIOD COVERED cologic Evaluation of Airborne Mixtures / Technical...REFERENCES (Cont’d) Nesnow, S., L. L. Triplett, and T. J. Slaga. 1981. Tumorigenesis of diesel exhaust, gasoline exhaust, and related emission

Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development and Tumorigenesis

DTIC Science & Technology

2008-10-01

AD_________________ AWARD NUMBER: W81XWH-06-1-0763 TITLE: Role of Fibroblast Growth Factor ...Role of Fibroblast Growth Factor Binding Protein-1 in Mammary Development and Tumorigenesis 5b. GRANT NUMBER W81XWH-06-1-0763 5c. PROGRAM...Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Fibroblast growth factors (FGFs) are vital modulators of development as well as

Establishment of 3D Co-Culture Models from Different Stages of Human Tongue Tumorigenesis: Utility in Understanding Neoplastic Progression.

PubMed

Sawant, Sharada; Dongre, Harsh; Singh, Archana Kumari; Joshi, Shriya; Costea, Daniela Elena; Mahadik, Snehal; Ahire, Chetan; Makani, Vidhi; Dange, Prerana; Sharma, Shilpi; Chaukar, Devendra; Vaidya, Milind

2016-01-01

To study multistep tumorigenesis process, there is a need of in-vitro 3D model simulating in-vivo tissue. Present study aimed to reconstitute in-vitro tissue models comprising various stages of neoplastic progression of tongue tumorigenesis and to evaluate the utility of these models to investigate the role of stromal fibroblasts in maintenance of desmosomal anchoring junctions using transmission electron microscopy. We reconstituted in-vitro models representing normal, dysplastic, and malignant tissues by seeding primary keratinocytes on either fibroblast embedded in collagen matrix or plain collagen matrix in growth factor-free medium. The findings of histomorphometry, immunohistochemistry, and electron microscopy analyses of the three types of 3D cultures showed that the stratified growth, cell proliferation, and differentiation were comparable between co-cultures and their respective native tissues; however, they largely differed in cultures grown without fibroblasts. The immunostaining intensity of proteins, viz., desmoplakin, desmoglein, and plakoglobin, was reduced as the disease stage increased in all co-cultures as observed in respective native tissues. Desmosome-like structures were identified using immunogold labeling in these cultures. Moreover, electron microscopic observations revealed that the desmosome number and their length were significantly reduced and intercellular spaces were increased in cultures grown without fibroblasts when compared with their co-culture counterparts. Our results showed that the major steps of tongue tumorigenesis can be reproduced in-vitro. Stromal fibroblasts play a role in regulation of epithelial thickness, cell proliferation, differentiation, and maintenance of desmosomalanchoring junctions in in-vitro grown tissues. The reconstituted co-culture models could help to answer various biological questions especially related to tongue tumorigenesis.

Restoring Retinoic Acid Attenuates Intestinal Inflammation and Tumorigenesis in APCMin/+ Mice.

PubMed

Penny, Hweixian Leong; Prestwood, Tyler R; Bhattacharya, Nupur; Sun, Fionna; Kenkel, Justin A; Davidson, Matthew G; Shen, Lei; Zuniga, Luis A; Seeley, E Scott; Pai, Reetesh; Choi, Okmi; Tolentino, Lorna; Wang, Jinshan; Napoli, Joseph L; Engleman, Edgar G

2016-11-01

Chronic intestinal inflammation accompanies familial adenomatous polyposis (FAP) and is a major risk factor for colorectal cancer in patients with this disease, but the cause of such inflammation is unknown. Because retinoic acid (RA) plays a critical role in maintaining immune homeostasis in the intestine, we hypothesized that altered RA metabolism contributes to inflammation and tumorigenesis in FAP. To assess this hypothesis, we analyzed RA metabolism in the intestines of patients with FAP as well as APC Min/+ mice, a model that recapitulates FAP in most respects. We also investigated the impact of intestinal RA repletion and depletion on tumorigenesis and inflammation in APC Min/+ mice. Tumors from both FAP patients and APC Min/+ mice displayed striking alterations in RA metabolism that resulted in reduced intestinal RA. APC Min/+ mice placed on a vitamin A-deficient diet exhibited further reductions in intestinal RA with concomitant increases in inflammation and tumor burden. Conversely, restoration of RA by pharmacologic blockade of the RA-catabolizing enzyme CYP26A1 attenuated inflammation and diminished tumor burden. To investigate the effect of RA deficiency on the gut immune system, we studied lamina propria dendritic cells (LPDC) because these cells play a central role in promoting tolerance. APC Min/+ LPDCs preferentially induced Th17 cells, but reverted to inducing Tregs following restoration of intestinal RA in vivo or direct treatment of LPDCs with RA in vitro These findings demonstrate the importance of intestinal RA deficiency in tumorigenesis and suggest that pharmacologic repletion of RA could reduce tumorigenesis in FAP patients. Cancer Immunol Res; 4(11); 917-26. ©2016 AACR. ©2016 American Association for Cancer Research.

Establishment of 3D Co-Culture Models from Different Stages of Human Tongue Tumorigenesis: Utility in Understanding Neoplastic Progression

PubMed Central

Sawant, Sharada; Dongre, Harsh; Singh, Archana Kumari; Joshi, Shriya; Costea, Daniela Elena; Mahadik, Snehal; Ahire, Chetan; Makani, Vidhi; Dange, Prerana; Sharma, Shilpi; Chaukar, Devendra; Vaidya, Milind

2016-01-01

To study multistep tumorigenesis process, there is a need of in-vitro 3D model simulating in-vivo tissue. Present study aimed to reconstitute in-vitro tissue models comprising various stages of neoplastic progression of tongue tumorigenesis and to evaluate the utility of these models to investigate the role of stromal fibroblasts in maintenance of desmosomal anchoring junctions using transmission electron microscopy. We reconstituted in-vitro models representing normal, dysplastic, and malignant tissues by seeding primary keratinocytes on either fibroblast embedded in collagen matrix or plain collagen matrix in growth factor-free medium. The findings of histomorphometry, immunohistochemistry, and electron microscopy analyses of the three types of 3D cultures showed that the stratified growth, cell proliferation, and differentiation were comparable between co-cultures and their respective native tissues; however, they largely differed in cultures grown without fibroblasts. The immunostaining intensity of proteins, viz., desmoplakin, desmoglein, and plakoglobin, was reduced as the disease stage increased in all co-cultures as observed in respective native tissues. Desmosome-like structures were identified using immunogold labeling in these cultures. Moreover, electron microscopic observations revealed that the desmosome number and their length were significantly reduced and intercellular spaces were increased in cultures grown without fibroblasts when compared with their co-culture counterparts. Our results showed that the major steps of tongue tumorigenesis can be reproduced in-vitro. Stromal fibroblasts play a role in regulation of epithelial thickness, cell proliferation, differentiation, and maintenance of desmosomalanchoring junctions in in-vitro grown tissues. The reconstituted co-culture models could help to answer various biological questions especially related to tongue tumorigenesis. PMID:27501241

Low-dose radiation induces Drosophila innate immunity through Toll pathway activation.

PubMed

Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Park, Joong-Jean; Min, Kyung-Jin; Jin, Young-Woo

2012-01-01

Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and JNK. These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila.

MYC and metabolism on the path to cancer

PubMed Central

Hsieh, Annie L.; Walton, Zandra E.; Altman, Brian J.; Stine, Zachary E.; Dang, Chi V.

2015-01-01

The MYC proto-oncogene is frequently deregulated in human cancers, activating genetic programs that orchestrate biological processes to promote growth and proliferation. Altered metabolism characterized by heightened nutrients uptake, enhanced glycolysis and glutaminolysis and elevated fatty acid and nucleotide synthesis is the hallmark of MYC-driven cancer. Recent evidence strongly suggests that Myc-dependent metabolic reprogramming is critical for tumorigenesis, which could be attenuated by targeting specific metabolic pathways using small drug-like molecules. Understanding the complexity of MYC-mediated metabolic re-wiring in cancers as well as how MYC cooperates with other metabolic drivers such as mammalian target of rapamycin (mTOR) will provide translational opportunities for cancer therapy. PMID:26277543

Circular RNA hsa_circ_0016788 regulates hepatocellular carcinoma tumorigenesis through miR-486/CDK4 pathway.

PubMed

Guan, Zheng; Tan, Jing; Gao, Wei; Li, Xin; Yang, Yuandong; Li, Xiaogang; Li, Yingchao; Wang, Qiang

2018-06-19

Recent studies have revealed that circular RNAs (circRNAs) play important roles in the tumorigenesis of human cancer, including hepatocellular carcinoma (HCC). In present study, we screen the circular RNA expression profiles in HCC tissue and investigate the molecular roles on HCC tumorigenesis. Human circRNA microarray analysis showed there were total 1,245 differently expressed circular RNAs, including 756 up-regulated circRNAs and 489 down-regulated circRNAs, in three pairs of HCC tissue and adjacent normal tissue. Hsa_circ_0016788 was identified to be up-regulated in both HCC tissue and cell lines. Loss-of-functional experiments in vivo and vitro revealed that hsa_circ_0016788 silencing inhibited the proliferation, invasion and promoted the apoptosis in vitro, and inhibited the tumor growth in vivo. Bioinformatics tools and luciferase reporter assay validated that miR-486 targeted hsa_circ_0016788 and CDK4 accompanying with negatively correlated expression, suggesting the hsa_circ_0016788/miR-486/CDK4 pathway. Receiver operating characteristic (ROC) curve showed that hsa_circ_0016788 had high diagnostic value (AUC = 0.851). In summary, results reveal the role of hsa_circ_0016788/miR-486/CDK4 in HCC tumorigenesis, providing a novel therapeutic target for HCC. © 2018 Wiley Periodicals, Inc.

Environmental exposure and HPV infection may act synergistically to induce lung tumorigenesis in nonsmokers

PubMed Central

Cheng, Ya-Wen; Lin, Frank Cheau-Feng; Chen, Chih-Yi; Hsu, Nan-Yung

2016-01-01

Most studies of lung tumorigenesis have focused on smokers rather than nonsmokers. In this study, we used human papillomavirus (HPV)-positive and HPV-negative lung cancer cells to test the hypothesis that HPV infection synergistically increases DNA damage induced by exposure to the carcinogen benzo[a]pyrene (B[a]P), and contributes to lung tumorigenesis in nonsmokers. DNA adduct levels induced by B[a]P in HPV-positive cells were significantly higher than in HPV-negative cells. The DNA adduct formation was dependent on HPV E6 oncoprotein expression. Gene and protein expression of two DNA repair genes, XRCC3 and XRCC5, were lower in B[a]P-treated E6-positive cells than in E6-negative lung cancer cells. The reduced expression was also detected immunohistochemically and was caused by increased promoter hypermethylation. Moreover, mutations of p53 and epidermal growth factor receptor (EGFR) genes in lung cancer patients were associated with XRCC5 inactivation. In sum, our study indicates that HPV E6-induced promoter hypermethylation of the XRCC3 and XRCC5 DNA repair genes and the resultant decrease in their expression increases B[a]P-induced DNA adducts and contributes to lung tumorigenesis in nonsmokers. PMID:26918347

STAT signaling in mammary gland differentiation, cell survival and tumorigenesis.

PubMed

Haricharan, S; Li, Y

2014-01-25

The mammary gland is a unique organ that undergoes extensive and profound changes during puberty, menstruation, pregnancy, lactation and involution. The changes that take place during puberty involve large-scale proliferation and invasion of the fat-pad. During pregnancy and lactation, the mammary cells are exposed to signaling pathways that inhibit apoptosis, induce proliferation and invoke terminal differentiation. Finally, during involution the mammary gland is exposed to milk stasis, programmed cell death and stromal reorganization to clear the differentiated milk-producing cells. Not surprisingly, the signaling pathways responsible for bringing about these changes in breast cells are often subverted during the process of tumorigenesis. The STAT family of proteins is involved in every stage of mammary gland development, and is also frequently implicated in breast tumorigenesis. While the roles of STAT3 and STAT5 during mammary gland development and tumorigenesis are well studied, others members, e.g. STAT1 and STAT6, have only recently been observed to play a role in mammary gland biology. Continued investigation into the STAT protein network in the mammary gland will likely yield new biomarkers and risk factors for breast cancer, and may also lead to novel prophylactic or therapeutic strategies against breast cancer. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Centrosomal Nlp is an oncogenic protein that is gene-amplified in human tumors and causes spontaneous tumorigenesis in transgenic mice.

PubMed

Shao, Shujuan; Liu, Rong; Wang, Yang; Song, Yongmei; Zuo, Lihui; Xue, Liyan; Lu, Ning; Hou, Ning; Wang, Mingrong; Yang, Xiao; Zhan, Qimin

2010-02-01

Disruption of mitotic events contributes greatly to genomic instability and results in mutator phenotypes. Indeed, abnormalities of mitotic components are closely associated with malignant transformation and tumorigenesis. Here we show that ninein-like protein (Nlp), a recently identified BRCA1-associated centrosomal protein involved in microtubule nucleation and spindle formation, is an oncogenic protein. Nlp was found to be overexpressed in approximately 80% of human breast and lung carcinomas analyzed. In human lung cancers, this deregulated expression was associated with NLP gene amplification. Further analysis revealed that Nlp exhibited strong oncogenic properties; for example, it conferred to NIH3T3 rodent fibroblasts the capacity for anchorage-independent growth in vitro and tumor formation in nude mice. Consistent with these data, transgenic mice overexpressing Nlp displayed spontaneous tumorigenesis in the breast, ovary, and testicle within 60 weeks. In addition, Nlp overexpression induced more rapid onset of radiation-induced lymphoma. Furthermore, mouse embryonic fibroblasts (MEFs) derived from Nlp transgenic mice showed centrosome amplification, suggesting that Nlp overexpression mimics BRCA1 loss. These findings demonstrate that Nlp abnormalities may contribute to genomic instability and tumorigenesis and suggest that Nlp might serve as a potential biomarker for clinical diagnosis and therapeutic target.

Centrosomal Nlp is an oncogenic protein that is gene-amplified in human tumors and causes spontaneous tumorigenesis in transgenic mice

PubMed Central

Shao, Shujuan; Liu, Rong; Wang, Yang; Song, Yongmei; Zuo, Lihui; Xue, Liyan; Lu, Ning; Hou, Ning; Wang, Mingrong; Yang, Xiao; Zhan, Qimin

2010-01-01

Disruption of mitotic events contributes greatly to genomic instability and results in mutator phenotypes. Indeed, abnormalities of mitotic components are closely associated with malignant transformation and tumorigenesis. Here we show that ninein-like protein (Nlp), a recently identified BRCA1-associated centrosomal protein involved in microtubule nucleation and spindle formation, is an oncogenic protein. Nlp was found to be overexpressed in approximately 80% of human breast and lung carcinomas analyzed. In human lung cancers, this deregulated expression was associated with NLP gene amplification. Further analysis revealed that Nlp exhibited strong oncogenic properties; for example, it conferred to NIH3T3 rodent fibroblasts the capacity for anchorage-independent growth in vitro and tumor formation in nude mice. Consistent with these data, transgenic mice overexpressing Nlp displayed spontaneous tumorigenesis in the breast, ovary, and testicle within 60 weeks. In addition, Nlp overexpression induced more rapid onset of radiation-induced lymphoma. Furthermore, mouse embryonic fibroblasts (MEFs) derived from Nlp transgenic mice showed centrosome amplification, suggesting that Nlp overexpression mimics BRCA1 loss. These findings demonstrate that Nlp abnormalities may contribute to genomic instability and tumorigenesis and suggest that Nlp might serve as a potential biomarker for clinical diagnosis and therapeutic target. PMID:20093778

Decrement of miR-199a-5p contributes to the tumorigenesis of bladder urothelial carcinoma by regulating MLK3/NF-κB pathway

PubMed Central

Song, Tao; Zhang, Xu; Yang, Guoqiang; Song, Yong; Cai, Wei

2015-01-01

Aberrant miRNA expression is implicated in tumorigenesis. However, the role of miRNAs in bladder urothelial carcinoma still remains largely unknown. In this study, miR-199a-5p was validated to be significantly down-regulated in bladder urothelial carcinoma. In addition, restoring expression of miR-199a-5p inhibited the tumorigenesis of bladder urothelial carcinoma in vitro and in vivo by inducing the apoptosis and suppressing the proliferation of bladder cancerous cells. Further investigation reported that MLK3 was a direct target of miR-199a-5p. Moreover, the expression level of miR-199a-5p was conversely correlated with MLK3 in bladder cancerous cells. In addition, reintroduction of MLK3 was identified to promote the proliferation and inhibit the apoptotic rate of cells, which have been altered by miR-199a-5p through activating the NF-κB pathway. All together, decrement of miR-199a-5p contributes to the tumorigenesis of bladder cancer by directly regulating MLK3/NF-κB pathway and miR-199a-5p might be developed as a therapeutic target for treatment of the bladder urothelial carcinoma. PMID:26885275

Chronic Inflammation: Synergistic Interactions of Recruiting Macrophages (TAMs) and Eosinophils (Eos) with Host Mast Cells (MCs) and Tumorigenesis in CALTs. M-CSF, Suitable Biomarker for Cancer Diagnosis!

PubMed

Khatami, Mahin

2014-01-27

Ongoing debates, misunderstandings and controversies on the role of inflammation in cancer have been extremely costly for taxpayers and cancer patients for over four decades. A reason for repeated failed clinical trials (90% ± 5 failure rates) is heavy investment on numerous genetic mutations (molecular false-flags) in the chaotic molecular landscape of site-specific cancers which are used for "targeted" therapies or "personalized" medicine. Recently, unresolved/chronic inflammation was defined as loss of balance between two tightly regulated and biologically opposing arms of acute inflammation ("Yin"-"Yang" or immune surveillance). Chronic inflammation could differentially erode architectural integrities in host immune-privileged or immune-responsive tissues as a common denominator in initiation and progression of nearly all age-associated neurodegenerative and autoimmune diseases and/or cancer. Analyses of data on our "accidental" discoveries in 1980s on models of acute and chronic inflammatory diseases in conjunctival-associated lymphoid tissues (CALTs) demonstrated at least three stages of interactions between resident (host) and recruited immune cells: (a), acute phase; activation of mast cells (MCs), IgE Abs, histamine and prostaglandin synthesis; (b), intermediate phase; down-regulation phenomenon, exhausted/degranulated MCs, heavy eosinophils (Eos) infiltrations into epithelia and goblet cells (GCs), tissue hypertrophy and neovascularization; and (c), chronic phase; induction of lymphoid hyperplasia, activated macrophages (Mfs), increased (irregular size) B and plasma cells, loss of integrity of lymphoid tissue capsular membrane, presence of histiocytes, follicular and germinal center formation, increased ratios of local IgG1/IgG2, epithelial thickening (growth) and/or thinning (necrosis) and angiogenesis. Results are suggestive of first evidence for direct association between inflammation and identifiable phases of immune dysfunction in the direction of tumorigenesis. Activated MFs (TAMs or M2) and Eos that are recruited by tissues (e.g., conjunctiva or perhaps lung airways) whose principal resident immune cells are MCs and lymphocytes are suggested to play crucial synergistic roles in enhancing growth promoting capacities of host toward tumorigenesis. Under oxidative stress, M-CSF may produce signals that are cumulative/synergistic with host mediators (e.g., low levels of histamine), facilitating tumor-directed expression of decoy receptors and immune suppressive factors (e.g., dTNFR, IL-5, IL-10, TGF-b, PGE2). M-CSF, possessing superior sensitivity and specificity, compared with conventional markers (e.g., CA-125, CA-19-9) is potentially a suitable biomarker for cancer diagnosis and technology development. Systematic monitoring of interactions between resident and recruited cells should provide key information not only about early events in loss of immune surveillance, but it would help making informed decisions for balancing the inherent tumoricidal (Yin) and tumorigenic (Yang) properties of immune system and effective preventive and therapeutic approaches and accurate risk assessment toward improvement of public health.

Induction of MDM2-P2 Transcripts Correlates with Stabilized Wild-Type p53 in Betel- and Tobacco-Related Human Oral Cancer

PubMed Central

Ralhan, Ranju; Sandhya, Agarwal; Meera, Mathur; Bohdan, Wasylyk; Nootan, Shukla K.

2000-01-01

MDM2, a critical element of cellular homeostasis mechanisms, is involved in complex interactions with important cell-cycle and stress-response regulators including p53. The mdm2-P2 promoter is a transcriptional target of p53. The aim of this study was to determine the association between mdm2-P2 transcripts and the status of the p53 gene in betel- and tobacco-related oral squamous cell carcinomas (SCCs) to understand the mechanism of deregulation of MDM2 and p53 expression and their prognostic implications in oral tumorigenesis. Elevated levels of MDM2 proteins were observed in 11 of 25 (44%) oral hyperplastic lesions, nine of 15 (60%) dysplastic lesions, and 71 of 100 (71%) SCCs. The intriguing feature of the study was the identification and different subcellular localization of three isoforms of MDM2 (ie, 90 kd, 76 kd, and 57 kd) in oral SCCs and their correlation with p53 overexpression in each tumor. The hallmark of the study was the detection of mdm2-P2 transcripts in 12 of 20 oral SCCs overexpressing both MDM2 and p53 proteins while harboring wild-type p53 alleles. Furthermore, mdm2 amplification was an infrequent event in betel- and tobacco-associated oral tumorigenesis. The differential compartmentalization of the three isoforms of MDM2 suggests that each has a distinct function, potentially in the regulation of p53 and other gene products implicated in oral tumorigenesis. In conclusion, we report herein the first evidence suggesting that enhanced translation of mdm2-P2 transcripts (S-mdm2) may represent an important mechanism of overexpression and consequent stabilization and functional inactivation of wild-type p53 serving as an adverse prognosticator in betel- and tobacco-related oral cancer. The clinical significance of the functional inactivation of wild-type p53 by MDM2 is underscored by the significantly shorter median disease-free survival time (16 months) observed in p53/MDM2-positive cases as compared to those which did not show co-expression of these proteins (median time, 26 months; P = 0.02). PMID:10934161

Tumorigenesis of K-ras mutation in human endometrial carcinoma via upregulation of estrogen receptor.

PubMed

Tu, Zheng; Gui, Liming; Wang, Jianliu; Li, Xiaoping; Sun, Pengming; Wei, Lihui

2006-05-01

To investigate the tumorigenesis of mutant [12Asp]-K-ras in endometrial carcinoma and its relationship with ER. We constructed pcDI-[12Asp]K-ras4B by inserting full-length [12Asp]K-ras4B from human endometrial carcinoma Hec-1A cells, into pcDI vector. Cell proliferation of NIH3T3 after transfection with pcDI-[12Asp]K-ras4B was measured by MTT assay. The cell transformation was determined by colony formation and tumor nodule development. [12Asp]-K-ras4B-NIH3T3 cells were transfected with constitutively active pCMV-RafCAAX and dominant-negative pCMV-RafS621A. Cell growth was measured by MTT assay and [3H]thymidine incorporation. After transfected with pcDI-[12Asp]K-ras4B or pCMV-RafS621A, the cells were harvested for Western blot and reporter assay to determine the expression and transcriptional activity of ERalpha and ERbeta, respectively. [12Asp]-K-ras4B enhanced NIH3T3 cells proliferation after 48 h post-transfection (P < 0.05). More colonies were grown 10 days after incubating pcDI-[12Asp]-K-ras4B-NIH3T3 cells (13.48%) than pcDI-NIH3T3 (4.26%) or untreated NIH3T3 (2.33%). The pcDI-[12Asp]-K-ras4B-NIH3T3 cells injected to the nude mice Balb/C developed tumor nodules with poor-differentiated cells after 12 days. An increase of ERalpha and ERbeta was observed in pcDI-[12Asp]-K-ras4B-NIH3T3 cells. RafS621A downregulated ERalpha and ERbeta expression. Estrogen induced the ER transcriptional activity by 5-fold in pcDI-NIH3T3 cells, 13-fold in pcDI-[12Asp]K-ras4B-NIH3T3 and 19-fold in HEC-1A. RafS621A suppressed the ER transcriptional activity. K-ras mutation induces tumorigenesis in endometrium, and this malignant transformation involves Raf signaling pathway and ER.

Heparanase augments insulin receptor signaling in breast carcinoma

PubMed Central

Goldberg, Rachel; Sonnenblick, Amir; Hermano, Esther; Hamburger, Tamar; Meirovitz, Amichay; Peretz, Tamar; Elkin, Michael

2017-01-01

Recently, growing interest in the potential link between metabolic disorders (i.e., diabetes, obesity, metabolic syndrome) and breast cancer has mounted, including studies which indicate that diabetic/hyperinsulinemic women have a significantly higher risk of bearing breast tumors that are more aggressive and associated with higher death rates. Insulin signaling is regarded as a major contributor to this phenomenon; much less is known about the role of heparan sulfate-degrading enzyme heparanase in the link between metabolic disorders and cancer. In the present study we analyzed clinical samples of breast carcinoma derived from diabetic/non-diabetic patients, and investigated effects of heparanase on insulin signaling in breast carcinoma cell lines, as well as insulin-driven growth of breast tumor cells. We demonstrate that heparanase activity leads to enhanced insulin signaling and activation of downstream tumor-promoting pathways in breast carcinoma cells. In agreement, heparanase enhances insulin-induced proliferation of breast tumor cells in vitro. Moreover, analyzing clinical data from diabetic breast carcinoma patients, we found that concurrent presence of both diabetic state and heparanase in tumor tissue (as opposed to either condition alone) was associated with more aggressive phenotype of breast tumors in the patient cohort analyzed in our study (two-sided Fisher's exact test; p=0.04). Our findings highlight the emerging role of heparanase in powering effect of hyperinsulinemic state on breast tumorigenesis and imply that heparanase targeting, which is now under intensive development/clinical testing, could be particularly efficient in a growing fraction of breast carcinoma patients suffering from metabolic disorders. PMID:28038446

The Analysis of Cell Population Dynamics in Mammary Gland Development and Tumorigenesis

DTIC Science & Technology

2005-08-01

AD Award Number: DAMD17-03-1-0498 TITLE: The Analysis of Cell Population Dynamics in Mammary Gland Development and Tumorigenesis PRINCIPAL...Summary 1 Aug 2004 - 31 Jul 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER The Analysis of Cell Population Dynamics in Mammary Gland Development and...STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The mammary gland is made up of several epithelial cell

Long noncoding RNA lnc-sox5 modulates CRC tumorigenesis by unbalancing tumor microenvironment.

PubMed

Wu, Kaiming; Zhao, Zhenxian; Liu, Kuanzhi; Zhang, Jian; Li, Guanghua; Wang, Liang

2017-07-03

Long non-coding RNAs (LncRNAs) have been recently regarded as systemic regulators in multiple biologic processes including tumorigenesis. In this study, we observed the expression of lncRNA lnc-sox5 was significantly increased in colorectal cancer (CRC). Despite the CRC cell growth, cell cycle and cell apoptosis was not affected by lnc-sox5 knock-down, lnc-sox5 knock-down suppressed CRC cell migration and invasion. In addition, xenograft animal model suggested that lnc-sox5 knock-down significantly suppressed the CRC tumorigenesis. Our results also showed that the expression of indoleamine 2,3-dioxygenase 1 (IDO1) was significantly reduced by lnc-sox5 knock-down and therefore modulated the infiltration and cytotoxicity of CD3 + CD8 + T cells. Taken together, these results suggested that lnc-sox5 unbalances tumor microenvironment to regulate colorectal cancer progression.

Non-metabolic functions of glycolytic enzymes in tumorigenesis.

PubMed

Yu, X; Li, S

2017-05-11

Cancer cells reprogram their metabolism to meet the requirement for survival and rapid growth. One hallmark of cancer metabolism is elevated aerobic glycolysis and reduced oxidative phosphorylation. Emerging evidence showed that most glycolytic enzymes are deregulated in cancer cells and play important roles in tumorigenesis. Recent studies revealed that all essential glycolytic enzymes can be translocated into nucleus where they participate in tumor progression independent of their canonical metabolic roles. These noncanonical functions include anti-apoptosis, regulation of epigenetic modifications, modulation of transcription factors and co-factors, extracellular cytokine, protein kinase activity and mTORC1 signaling pathway, suggesting that these multifaceted glycolytic enzymes not only function in canonical metabolism but also directly link metabolism to epigenetic and transcription programs implicated in tumorigenesis. These findings underscore our understanding about how tumor cells adapt to nutrient and fuel availability in the environment and most importantly, provide insights into development of cancer therapy.

Hippo Signaling Suppresses Cell Ploidy and Tumorigenesis through Skp2.

PubMed

Zhang, Shihao; Chen, Qinghua; Liu, Qingxu; Li, Yuxi; Sun, Xiufeng; Hong, Lixin; Ji, Suyuan; Liu, Chengyan; Geng, Jing; Zhang, Weiji; Lu, Zhonglei; Yin, Zhen-Yu; Zeng, Yuanyuan; Lin, Kwang-Huei; Wu, Qiao; Li, Qiyuan; Nakayama, Keiko; Nakayama, Keiich I; Deng, Xianming; Johnson, Randy L; Zhu, Liang; Gao, Daming; Chen, Lanfen; Zhou, Dawang

2017-05-08

Polyploidy can lead to aneuploidy and tumorigenesis. Here, we report that the Hippo pathway effector Yap promotes the diploid-polyploid conversion and polyploid cell growth through the Akt-Skp2 axis. Yap strongly induces the acetyltransferase p300-mediated acetylation of the E3 ligase Skp2 via Akt signaling. Acetylated Skp2 is exclusively localized to the cytosol, which causes hyper-accumulation of the cyclin-dependent kinase inhibitor p27, leading to mitotic arrest and subsequently cell polyploidy. In addition, the pro-apoptotic factors FoxO1/3 are overly degraded by acetylated Skp2, resulting in polyploid cell division, genomic instability, and oncogenesis. Importantly, the depletion or inactivation of Akt or Skp2 abrogated Hippo signal deficiency-induced liver tumorigenesis, indicating their epistatic interaction. Thus, we conclude that Hippo-Yap signaling suppresses cell polyploidy and oncogenesis through Skp2. Copyright © 2017 Elsevier Inc. All rights reserved.

Ambient Oxygen Promotes Tumorigenesis

PubMed Central

Starost, Matthew F.; Lago, Cory U.; Lim, Philip K.; Sack, Michael N.; Kang, Ju-Gyeong; Wang, Ping-yuan; Hwang, Paul M.

2011-01-01

Oxygen serves as an essential factor for oxidative stress, and it has been shown to be a mutagen in bacteria. While it is well established that ambient oxygen can also cause genomic instability in cultured mammalian cells, its effect on de novo tumorigenesis at the organismal level is unclear. Herein, by decreasing ambient oxygen exposure, we report a ∼50% increase in the median tumor-free survival time of p53−/− mice. In the thymus, reducing oxygen exposure decreased the levels of oxidative DNA damage and RAG recombinase, both of which are known to promote lymphomagenesis in p53−/− mice. Oxygen is further shown to be associated with genomic instability in two additional cancer models involving the APC tumor suppressor gene and chemical carcinogenesis. Together, these observations represent the first report directly testing the effect of ambient oxygen on de novo tumorigenesis and provide important physiologic evidence demonstrating its critical role in increasing genomic instability in vivo. PMID:21589870

Hyaline cartilage formation and tumorigenesis of implanted tissues derived from human induced pluripotent stem cells.

PubMed

Saito, Taku; Yano, Fumiko; Mori, Daisuke; Kawata, Manabu; Hoshi, Kazuto; Takato, Tsuyoshi; Masaki, Hideki; Otsu, Makoto; Eto, Koji; Nakauchi, Hiromitsu; Chung, Ung-il; Tanaka, Sakae

2015-01-01

Induced pluripotent stem cells (iPSCs) are a promising cell source for cartilage regenerative medicine. Meanwhile, the risk of tumorigenesis should be considered in the clinical application of human iPSCs (hiPSCs). Here, we report in vitro chondrogenic differentiation of hiPSCs and maturation of the differentiated hiPSCs through transplantation into mouse knee joints. Three hiPSC clones showed efficient chondrogenic differentiation using an established protocol for human embryonic stem cells. The differentiated hiPSCs formed hyaline cartilage tissues at 8 weeks after transplantation into the articular cartilage of NOD/SCID mouse knee joints. Although tumors were not observed during the 8 weeks after transplantation, an immature teratoma had developed in one mouse at 16 weeks. In conclusion, hiPSCs are a potent cell source for regeneration of hyaline articular cartilage. However, the risk of tumorigenesis should be managed for clinical application in the future.

MiR-218 Mediates tumorigenesis and metastasis: Perspectives and implications

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

Lu, Ying-fei; Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong; Zhang, Li

2015-05-15

MicroRNAs (miRNAs) are a class of small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. As a highly conserved miRNA across a variety of species, microRNA-218 (miR-218) was found to play pivotal roles in tumorigenesis and progression. A group of evidence has demonstrated that miR-218 acts as a tumor suppressor by targeting many oncogenes related to proliferation, apoptosis and invasion. In this review, we provide a complex overview of miR-218, including its regulatory mechanisms, known functions in cancer and future challenges as a potential therapeutic target in human cancers. - Highlights: • miR-218 is frequently down regulatedmore » in multiple cancers. • miR-218 plays pivotal roles in carcinogenesis. • miR-218 mediates proliferation, apoptosis, metastasis, invasion, etc. • miR-218 mediates tumorigenesis and metastasis via multiple pathways.« less

Dietary calcium and cholecalciferol modulate cyclin D1 expression, apoptosis, and tumorigenesis in intestine of adenomatous polyposis coli1638N/+ mice.

PubMed

Yang, Kan; Lamprecht, Sergio A; Shinozaki, Hiroharu; Fan, Kunhua; Yang, Wancai; Newmark, Harold L; Kopelovich, Levy; Edelmann, Winfried; Jin, Bo; Gravaghi, Claudia; Augenlicht, Leonard; Kucherlapati, Raju; Lipkin, Martin

2008-09-01

Both epidemiological and experimental findings have indicated that components of Western diets influence colonic tumorigenesis. Among dietary constituents, calcium and cholecalciferol have emerged as promising chemopreventive agents. We have demonstrated that a Western-style diet (WD) with low levels of calcium and cholecalciferol and high levels of (n-6) PUFA, increased the incidence of neoplasia in mouse intestine compared with a standard AIN-76A diet; models included wild-type mice and mice with targeted mutations. In the present study, adenomatous polyposis coli (Apc)(1638N/+) mice carrying a heterozygous Apc mutation were fed either an AIN-76A diet, a WD, or a WD supplemented with calcium and cholecalciferol (WD/Ca/VitD3). Diets were fed for 24 wk and effects on cellular and molecular events were assessed by performing immunohistochemistry in colonic epithelium along the crypt-to-surface continuum. Feeding WD to Apc(1638N/+) mice not only enhanced cyclin D1 expression in colonic epithelium compared with AIN-76A treatment as previously reported but also significantly increased the expression of the antiapoptotic protein B-cell lymphoma 2 (Bcl-2) concomitantly with a decrease in the proapoptotic Bcl2-associated X protein and the number of apoptotic epithelial cells. WD treatment enhanced mutant Apc-driven small intestinal carcinogenesis and also resulted in the formation of a small number of colonic adenomas (0.16 +/- 0.09; P < 0.05). By contrast, the WD/Ca/VitD3 diet reversed WD-induced growth, promoting changes in colonic epithelium. Importantly, Apc(1638N/+) mice fed the WD/Ca/VitD3 diet did not develop colonic tumors, further indicating that dietary calcium and cholecalciferol have a key role in the chemoprevention of colorectal neoplasia in this mouse model of human colon cancer.

Expression of the pituitary stem/progenitor marker GFRα2 in human pituitary adenomas and normal pituitary

PubMed Central

Mathioudakis, Nestoras; Sundaresh, Ram; Larsen, Alexandra; Ruff, William; Schiller, Jennifer; Cázares, Hugo Guerrero; Burger, Peter; Salvatori, Roberto; Quiñones-Hinojosa, Alfredo

2014-01-01

Purpose Recent studies suggest that adult pituitary stem cells may play a role in pituitary tumorigenesis. We sought to explore whether the Glial cell-line derived neurotrophic factor receptor alpha 2 (GFRα2), a recently described pituitary stem/progenitor marker, might be differentially expressed in pituitary adenomas versus normal pituitary. Methods The expression of GFRα2 and other members of the GFR receptor family (GFRα1, α3, α4) were analyzed using RT-PCR, western blot, and immunohistochemistry in 39 pituitary adenomas, 14 normal pituitary glands obtained at autopsy, and cDNA from 3 normal pituitaries obtained commercially. Results GFRα2 mRNA was ~2.6 fold under-expressed in functioning adenomas (P <0.01) and ~3.5 fold over-expressed in non-functioning adenomas (NFAs) (P <0.05) compared to normal pituitary. Among NFAs, GFRα2 was significantly over-expressed (~5-fold) in the gonadotropinoma subtype only (P<0.05). GFRα2 protein expression appeared to be higher in most NFAs, although there was heterogeneity in protein expression in this group. GFRα2 protein expression appeared consistently lower in functioning adenomas by IHC and western blot. In normal pituitary, GFRα2 was localized in Rathke’s remnant, the putative pituitary stem cell niche, and in corticotropes. Conclusion Our results suggest that the pituitary stem cell marker GFRα2 is under-expressed in functioning adenomas and over-expressed in NFAs, specifically gonadotropinomas. Further studies are required to elucidate whether over-expression of GFRα2 in gonadotropinomas might play a role in pituitary tumorigenesis. PMID:24402129

Genetic and Pharmacological Strategies to Refunctionalize the von Hippel Lindau R167Q Mutant Protein

PubMed Central

Ding, Zhiyong; German, Peter; Bai, Shanshan; Reddy, A. Srinivas; Liu, Xian-De; Sun, Mianen; Zhou, Lijun; Chen, Xiaohua; Zhao, Xiaobei; Wu, Chengbiao; Zhang, Shuxing; Mills, Gordon B.; Jonasch, Eric

2014-01-01

Aberrant von Hippel Lindau (VHL) protein function is the underlying driver of VHL-related diseases, including both sporadic and inherited clear cell renal cell carcinoma (ccRCC). About one third of VHL mutations are missense point mutations, with R167Q being the most common VHL point mutation in hereditary VHL disease. Although it has been studied extensively, the ability of VHL-R167Q to downregulate hypoxia inducible factor 2α (HIF2α) is still controversial. In addition, the manner in which the mutation contributes to tumorigenesis is not fully understood. No therapeutic approach is available to target VHL-R167Q and similar missense point mutations. We analyzed VHL-R167Q proteostasis and function at normoxia, at hypoxia with different oxygen pressure, and in a xenograft mouse model. We showed that the protein levels of VHL-R167Q dictate its ability to downregulate HIF2α and suppress tumor growth. Strikingly, the proteasome inhibitors bortezomib and carfilzomib, which are currently in clinical use, stabilize VHL-R167Q and increase its ability to downregulate HIF2α. VHL-R167Q binds elongin C and elongin B with considerably less avidity than wild-type VHL does but retains residual capacity to generate a VHL-elongin C-elongin B complex, downregulate HIF2α, and suppress tumorigenesis, which could be rescued by increase VHL-R167Q levels. Finally, we used in silico approaches and identified other missense VHL mutants in addition to VHL-R167Q that might be rescued by similar strategies. Thus, our studies revealed detailed information describing how VHL-R167Q contributes to tumorigenesis and identified a potential targeted therapy for ccRCC and other VHL-related disease in patients carrying VHL-R167Q or similar missense mutations. PMID:24755468

Fusobacterium nucleatum Potentiates Intestinal Tumorigenesis in Mice via a Toll-Like Receptor 4/p21-Activated Kinase 1 Cascade.

PubMed

Wu, Yaxin; Wu, Jiao; Chen, Ting; Li, Qing; Peng, Wei; Li, Huan; Tang, Xiaowei; Fu, Xiangsheng

2018-05-01

The underlying pathogenic mechanism of Fusobacterium nucleatum in the carcinogenesis of colorectal cancer has been poorly understood. Using C57BL/6-Apc Min/+ mice, we investigated gut microbial structures with F. nucleatum, antibiotics, and Toll-like receptor 4 (TLR4) antagonist TAK-242 treatment. In addition, we measured intestinal tumor formation and the expression of TLR4, p21-activated kinase 1 (PAK1), phosphorylated-PAK1 (p-PAK1), phosphorylated-β-catenin S675 (p-β-catenin S675), and cyclin D1 in mice with different treatments. Fusobacterium nucleatum and antibiotics treatment altered gut microbial structures in mice. In addition, F. nucleatum invaded into the intestinal mucosa in large amounts but were less abundant in the feces of F. nucleatum-fed mice. The average number and size of intestinal tumors in F. nucleatum groups was significantly increased compared to control groups in Apc Min/+ mice (P < 0.05). The expression of TLR4, PAK1, p-PAK1, p-β-catenin S675, and cyclin D1 was significantly increased in F. nucleatum groups compared to the control groups (P < 0.05). Moreover, TAK-242 significantly decreased the average number and size of intestinal tumors compared to F. nucleatum groups (P < 0.05). The expression of p-PAK1, p-β-catenin S675, and cyclin D1 was also significantly decreased in the TAK-242-treated group compared to F. nucleatum groups (P < 0.05). Fusobacterium nucleatum potentiates intestinal tumorigenesis in Apc Min/+ mice via a TLR4/p-PAK1/p-β-catenin S675 cascade. Fusobacterium nucleatum-induced intestinal tumorigenesis can be inhibited by TAK-242, implicating TLR4 as a potential target for the prevention and therapy of F. nucleatum-related colorectal cancer.

Adipose progenitor cells increase fibronectin matrix strain and unfolding in breast tumors

NASA Astrophysics Data System (ADS)

Chandler, E. M.; Saunders, M. P.; Yoon, C. J.; Gourdon, D.; Fischbach, C.

2011-02-01

Increased stiffness represents a hallmark of breast cancer that has been attributed to the altered physicochemical properties of the extracellular matrix (ECM). However, the role of fibronectin (Fn) in modulating the composition and mechanical properties of the tumor-associated ECM remains unclear. We have utilized a combination of biochemical and physical science tools to evaluate whether paracrine signaling between breast cancer cells and adipose progenitor cells regulates Fn matrix assembly and stiffness enhancement in the tumor stroma. In particular, we utilized fluorescence resonance energy transfer imaging to map the molecular conformation and stiffness of Fn that has been assembled by 3T3-L1 preadipocytes in response to conditioned media from MDA-MB231 breast cancer cells. Our results reveal that soluble factors secreted by tumor cells promote Fn expression, unfolding, and stiffening by adipose progenitor cells and that transforming growth factor-β serves as a soluble cue underlying these changes. In vivo experiments using orthotopic co-transplantation of primary human adipose-derived stem cells and MDA-MB231 into SCID mice support the pathological relevance of our results. Insights gained by these studies advance our understanding of the role of Fn in mammary tumorigenesis and may ultimately lead to improved anti-cancer therapies.

Cancer Development, Progression, and Therapy: An Epigenetic Overview

PubMed Central

Sarkar, Sibaji; Horn, Garrick; Moulton, Kimberly; Oza, Anuja; Byler, Shannon; Kokolus, Shannon; Longacre, McKenna

2013-01-01

Carcinogenesis involves uncontrolled cell growth, which follows the activation of oncogenes and/or the deactivation of tumor suppression genes. Metastasis requires down-regulation of cell adhesion receptors necessary for tissue-specific, cell–cell attachment, as well as up-regulation of receptors that enhance cell motility. Epigenetic changes, including histone modifications, DNA methylation, and DNA hydroxymethylation, can modify these characteristics. Targets for these epigenetic changes include signaling pathways that regulate apoptosis and autophagy, as well as microRNA. We propose that predisposed normal cells convert to cancer progenitor cells that, after growing, undergo an epithelial-mesenchymal transition. This process, which is partially under epigenetic control, can create a metastatic form of both progenitor and full-fledged cancer cells, after which metastasis to a distant location may occur. Identification of epigenetic regulatory mechanisms has provided potential therapeutic avenues. In particular, epigenetic drugs appear to potentiate the action of traditional therapeutics, often by demethylating and re-expressing tumor suppressor genes to inhibit tumorigenesis. Epigenetic drugs may inhibit both the formation and growth of cancer progenitor cells, thus reducing the recurrence of cancer. Adopting epigenetic alteration as a new hallmark of cancer is a logical and necessary step that will further encourage the development of novel epigenetic biomarkers and therapeutics. PMID:24152442

Regulation of Cancer Stem Cell Self-Renewal by HOXB9 Antagonizes Endoplasmic Reticulum Stress-Induced Melanoma Cell Apoptosis via the miR-765-FOXA2 Axis.

PubMed

Lin, Jingrong; Zhang, Dongmei; Fan, Yongsheng; Chao, Yulin; Chang, Jinming; Li, Na; Han, Linlin; Han, Chuanchun

2018-07-01

Adaptation to endoplasmic reticulum (ER) stress has been indicated as a driver of malignancy and resistance to therapy in human melanoma. However, the relationship between cancer stem cells and adaptation to ER stress remains unclear. Here, we show that the ratio of cancer stem cells is increased in ER stress-resistant melanoma cells, which inhibit ER stress-induced apoptosis and promote tumorigenesis. Further mechanistic studies showed that HOXB9 triggered by ER stress favors cancer stem cell self-renewal and enhances ER stress resistance. HOXB9 directly binds to the promoter of microRNA-765 and facilitates its transcription, which in turn targets FOXA2, resulting in a FOXA2 decrease and cancer stem cell increase. Additionally, an increase in HOXB9 promotes melanoma growth and inhibits cell apoptosis in a mouse xenograft model. Elevated HOXB9 is found in human melanoma tissues, which is associated with microRNA-765 up-regulation and FOXA2 decreases. Thus, our data showed that the HOXB9-dependent, microRNA-765-mediated FOXA2 pathway contributes to the survival of melanoma under ER stress by maintaining the properties of cancer stem cells. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Gain-of-function mutations of Ptpn11 (Shp2) cause aberrant mitosis and increase susceptibility to DNA damage-induced malignancies

PubMed Central

Liu, Xia; Zheng, Hong; Li, Xiaobo; Wang, Siying; Meyerson, Howard J.; Yang, Wentian; Neel, Benjamin G.; Qu, Cheng-Kui

2016-01-01

Gain-of-function (GOF) mutations of protein tyrosine phosphatase nonreceptor type 11 Ptpn11 (Shp2), a protein tyrosine phosphatase implicated in multiple cell signaling pathways, are associated with childhood leukemias and solid tumors. The underlying mechanisms are not fully understood. Here, we report that Ptpn11 GOF mutations disturb mitosis and cytokinesis, causing chromosomal instability and greatly increased susceptibility to DNA damage-induced malignancies. We find that Shp2 is distributed to the kinetochore, centrosome, spindle midzone, and midbody, all of which are known to play critical roles in chromosome segregation and cytokinesis. Mouse embryonic fibroblasts with Ptpn11 GOF mutations show a compromised mitotic checkpoint. Centrosome amplification and aberrant mitosis with misaligned or lagging chromosomes are significantly increased in Ptpn11-mutated mouse and patient cells. Abnormal cytokinesis is also markedly increased in these cells. Further mechanistic analyses reveal that GOF mutant Shp2 hyperactivates the Polo-like kinase 1 (Plk1) kinase by enhancing c-Src kinase-mediated tyrosine phosphorylation of Plk1. This study provides novel insights into the tumorigenesis associated with Ptpn11 GOF mutations and cautions that DNA-damaging treatments in Noonan syndrome patients with germ-line Ptpn11 GOF mutations could increase the risk of therapy-induced malignancies. PMID:26755576

Effects on DNA Damage and/or Repair Processes as Biological Mechanisms Linking Psychological Stress to Cancer Risk

PubMed Central

Jenkins, Frank J.; Van Houten, Bennett; Bovbjerg, Dana H.

2014-01-01

Considerable research effort in the past several decades has focused on the impact of psychological stress, and stress hormones, on cancer progression. Numerous studies have reported that stress hormone treatment or in vivo stress exposure can enhance the growth of tumor cell lines in vitro, as well as tumors in animal models, and have begun to explore molecular mechanisms. Comparatively little research has focused on the impact of psychological stress and stress hormones on cancer initiation, in part due to inherent methodological challenges, but also because potential underlying biological mechanisms have remained obscure. In this review, we present a testable theoretical model of pathways by which stress may result in cellular transformation and tumorigenesis. This model supports our overarching hypothesis that psychological stress, acting through increased levels of catecholamines and/or cortisol, can increase DNA damage and/or reduce repair mechanisms, resulting in increased risk of DNA mutations leading to carcinogenesis. A better understanding of molecular pathways by which psychological stress can increase the risk of cancer initiation would open new avenues of translational research, bringing together psychologists, neuroscientists, and molecular biologists, potentially resulting in the development of novel approaches for cancer risk reduction at the population level. PMID:24891812

Inhibition of EGFR nuclear shuttling decreases irradiation resistance in HeLa cells.

PubMed

Wei, Hong; Zhu, Zijie; Lu, Longtao

2017-01-01

Cervical cancer is a leading cause of mortality in women worldwide. The resistance to irradiation at the advanced stage is the main reason for the poor prognosis and high mortality. This work aims to elucidate the molecular mechanism underlying the radio-resistance. In this study, we determined the pEGFR-T654 and pDNA-PK-T2609 expression level changes in irradiated HeLa cells treated with T654 peptide, a nuclear localization signal (NLS) inhibitor, to inhibit EGFR nuclear transport. Cell viability, cell cycle and migratory capacity were analyzed. Xenograft animal model was used to evaluate the effect of EGFR nuclear transport inhibition on the tumor growth in vivo. The enhanced translocation of nuclear EGFR in the irradiated HeLa cells correlated with the increasing level of pEGFR-T654 and pDNA-PK-T2609. Inhibition of EGFR nuclear translocation by NLS peptide inhibitor attenuated DNA damage repair in the irradiated HeLa cells, decreased cell viability and promoted cell death through arrest at G0 phase. NLS peptide inhibitor impaired the migratory capacity of irradiated HeLa cells, and negatively affected tumorigenesis in xenograft mice. This work puts forward a potential molecular mechanism of the irradiation resistance in cervical cancer cells, providing a promising direction towards an efficient therapy of cervical cancer.

Myocardial regeneration potential of adipose tissue-derived stem cells

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

Bai, Xiaowen, E-mail: baixw01@yahoo.com; Alt, Eckhard, E-mail: ealt@mdanderson.org

Research highlights: {yields} Various tissue resident stem cells are receiving tremendous attention from basic scientists and clinicians and hold great promise for myocardial regeneration. {yields} For practical reasons, human adipose tissue-derived stem cells are attractive stem cells for future clinical application in repairing damaged myocardium. {yields} This review summarizes the characteristics of cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential and the, underlying mechanisms, and safety issues. -- Abstract: Various tissue resident stem cells are receiving attention from basic scientists and clinicians as they hold promise for myocardial regeneration. For practical reasons, adipose tissue-derivedmore » stem cells (ASCs) are attractive cells for clinical application in repairing damaged myocardium based on the following advantages: abundant adipose tissue in most patients and easy accessibility with minimally invasive lipoaspiration procedure. Several recent studies have demonstrated that both cultured and freshly isolated ASCs could improve cardiac function in animal model of myocardial infarction. The mechanisms underlying the beneficial effect of ASCs on myocardial regeneration are not fully understood. Growing evidence indicates that transplantation of ASCs improve cardiac function via the differentiation into cardiomyocytes and vascular cells, and through paracrine pathways. Paracrine factors secreted by injected ASCs enhance angiogenesis, reduce cell apoptosis rates, and promote neuron sprouts in damaged myocardium. In addition, Injection of ASCs increases electrical stability of the injured heart. Furthermore, there are no reported cases of arrhythmia or tumorigenesis in any studies regarding myocardial regeneration with ASCs. This review summarizes the characteristics of both cultured and freshly isolated stem cells obtained from adipose tissue, their myocardial regeneration potential, and the underlying mechanisms for beneficial effect on cardiac function, and safety issues.« less

Downregulated PITX1 Modulated by MiR-19a-3p Promotes Cell Malignancy and Predicts a Poor Prognosis of Gastric Cancer by Affecting Transcriptionally Activated PDCD5.

PubMed

Qiao, Fengchang; Gong, Pihai; Song, Yunwei; Shen, Xiaohui; Su, Xianwei; Li, Yiping; Wu, Huazhang; Zhao, Zhujiang; Fan, Hong

2018-01-01

PITX1 has been identified as a potential tumor-suppressor gene in several malignant tumors. The molecular mechanism underlying PITX1, particularly its function as a transcription factor regulating gene expression during tumorigenesis, is still poorly understood. The expression level and location of PITX1 were determined by quantitative reverse transcription PCR (qRT-PCR) and immunohistochemical staining in gastric cancer (GC). The effect of PITX1 on the GC cell proliferation and tumorigenesis was analyzed in vitro and in vivo. To explore how PITX1 suppresses cell proliferation, we used PITX1-ChIP-sequencing to measure genome-wide binding sites of PITX1 and assessed global function associations based on its putative target genes. ChIP-PCR, electrophoretic mobility shift assay, and promoter reporter assays examined whether PITX1 bound to PDCD5 and regulated its expression. The function of PDCD5 in GC cell apoptosis was further examined in vitro and in vivo. The relationship between the PITX1 protein level and GC patient prognosis was evaluated by the Kaplan-Meier estimator. Meanwhile, the expression level of miR-19a-3p, which is related to PITX1, was also detected by luciferase reporter assay, qRT-PCR, and western blotting. The expression level of PITX1 was decreased in GC tissues and cell lines. Elevated PITX1 expression significantly suppressed the cell proliferation of GC cells and tumorigenesis in vitro and in vivo. PITX1 knockdown blocked its inhibition of GC cell proliferation. PITX1 bound to whole genome-wide sites, with these targets enriched on genes with functions mainly related to cell growth and apoptosis. PITX1 bound to PDCD5, an apoptosis-related gene, during tumorigenesis, and cis-regulated PDCD5 expression. Increased PDCD5 expression in GC cells not only induced GC cell apoptosis, but also suppressed GC cell growth in vitro and in vivo. Moreover, PITX1 expression was regulated by miR-19a-3p. More importantly, a decreased level of PITX1 protein was correlated with poor GC patient prognosis. Decreased expression of PITX1 predicts shorter overall survival in GC patients. As a transcriptional activator, PITX1 regulates apoptosis-related genes, including PDCD5, during gastric carcinogenesis. These data indicate PDCD5 to be a novel and feasible therapeutic target for GC. © 2018 The Author(s). Published by S. Karger AG, Basel.

SRC-2-mediated coactivation of anti-tumorigenic target genes suppresses MYC-induced liver cancer

PubMed Central

Zhou, Xiaorong; Comerford, Sarah A.; York, Brian; O’Donnell, Kathryn A.

2017-01-01

Hepatocellular carcinoma (HCC) is the fifth most common solid tumor in the world and the third leading cause of cancer-associated deaths. A Sleeping Beauty-mediated transposon mutagenesis screen previously identified mutations that cooperate with MYC to accelerate liver tumorigenesis. This revealed a tumor suppressor role for Steroid Receptor Coactivator 2/Nuclear Receptor Coactivator 2 (Src-2/Ncoa2) in liver cancer. In contrast, SRC-2 promotes survival and metastasis in prostate cancer cells, suggesting a tissue-specific and context-dependent role for SRC-2 in tumorigenesis. To determine if genetic loss of SRC-2 is sufficient to accelerate MYC-mediated liver tumorigenesis, we bred Src-2-/- mice with a MYC-induced liver tumor model and observed a significant increase in liver tumor burden. RNA sequencing of liver tumors and in vivo chromatin immunoprecipitation assays revealed a set of direct target genes that are bound by SRC-2 and exhibit downregulated expression in Src-2-/- liver tumors. We demonstrate that activation of SHP (Small Heterodimer Partner), DKK4 (Dickkopf-4), and CADM4 (Cell Adhesion Molecule 4) by SRC-2 suppresses tumorigenesis in vitro and in vivo. These studies suggest that SRC-2 may exhibit oncogenic or tumor suppressor activity depending on the target genes and nuclear receptors that are expressed in distinct tissues and illuminate the mechanisms of tumor suppression by SRC-2 in liver. PMID:28273073

DA-Raf, a dominant-negative antagonist of the Ras-ERK pathway, is a putative tumor suppressor.

PubMed

Kanno, Emiri; Kawasaki, Osamu; Takahashi, Kazuya; Takano, Kazunori; Endo, Takeshi

2018-01-01

Activating mutations of RAS genes, particularly KRAS, are detected with high frequency in human tumors. Mutated Ras proteins constitutively activate the ERK pathway (Raf-MEK-ERK phosphorylation cascade), leading to cellular transformation and tumorigenesis. DA-Raf1 (DA-Raf) is a splicing variant of A-Raf and contains the Ras-binding domain (RBD) but lacks the kinase domain. Accordingly, DA-Raf antagonizes the Ras-ERK pathway in a dominant-negative fashion and suppresses constitutively activated K-Ras-induced cellular transformation. Thus, we have addressed whether DA-Raf serves as a tumor suppressor of Ras-induced tumorigenesis. DA-Raf(R52Q), which is generated from a single nucleotide polymorphism (SNP) in the RBD, and DA-Raf(R52W), a mutant detected in a lung cancer, neither bound to active K-Ras nor interfered with the activation of the ERK pathway. They were incapable of suppressing activated K-Ras-induced cellular transformation and tumorigenesis in mice, in which K-Ras-transformed cells were transplanted. Furthermore, although DA-Raf was highly expressed in lung alveolar epithelial type 2 (AE2) cells, its expression was silenced in AE2-derived lung adenocarcinoma cell lines with oncogenic KRAS mutations. These results suggest that DA-Raf represents a tumor suppressor protein against Ras-induced tumorigenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Erbin loss promotes cancer cell proliferation through feedback activation of Akt-Skp2-p27 signaling

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

Huang, Hao; Laboratory of Cellular and Molecular Immunology, Medical School of Henan University, Kaifeng 475004; Song, Yuhua

2015-07-31

Erbin localizes at the basolateral membrane to regulate cell junctions and polarity in epithelial cells. Dysregulation of Erbin has been implicated in tumorigenesis, and yet it is still unclear if and how disrupted Erbin regulates the biological behavior of cancer cells. We report here that depletion of Erbin leads to cancer cell excessive proliferation in vitro and in vivo. Erbin deficiency accelerates S-phase entry by down-regulating CDK inhibitors p21 and p27 via two independent mechanisms. Mechanistically, Erbin loss promotes p27 degradation by enhancing E3 ligase Skp2 activity though augmenting Akt signaling. Interestingly, we also show that Erbin is an unstable protein whenmore » the Akt-Skp2 signaling is aberrantly activated, which can be specifically destructed by SCF-Skp2 ligase. Erbin loss facilitates cell proliferation and migration in Skp2-dependent manner. Thus, our finding illustrates a novel negative feedback loop between Erbin and Akt-Skp2 signaling. It suggests disrupted Erbin links polarity loss, hyperproliferation and tumorigenesis. - Highlights: • Erbin loss leads to cancer cell excessive proliferation in vitro and in vivo. • Erbin loss accelerates cell cycle though down-regulating p21 and p27 expression. • Erbin is a novel negative modulator of Akt1-Skp2-p27 signaling pathway. • Our study suggests that Erbin loss contributes to Skp2 oncogenic function.« less

Nitrilase 1 modulates lung tumor progression in vitro and in vivo

PubMed Central

Wang, Yong Antican; Sun, Yunguang; Le Blanc, Justin M.; Solomides, Charalambos; Zhan, Tingting; Lu, Bo

2016-01-01

Uncovering novel growth modulators for non-small cell lung cancer (NSCLC) may lead to new therapies for these patients. Previous studies suggest Nit1 suppresses chemically induced carcinogenesis of the foregut in a mouse model. In this study we aimed to determine the role of Nit1 in a transgenic mouse lung cancer model driven by a G12D Kras mutation. Nit1 knockout mice (Nit1−/−) were crossed with KrasG12D/+ mice to investigate whether a G12D Kras mutation and Nit1 inactivation interact to promote or inhibit the development of NSCLC. We found that lung tumorigenesis was suppressed in the Nit1-null background (Nit1−/−:KrasG12D/+). Micro-CT scans and gross tumor measurements demonstrated a 5-fold reduction in total tumor volumes compared to Nit1+/+KrasG12D/+ (p<0.01). Furthermore, we found that Nit1 is highly expressed in human lung cancer tissues and cell lines and use of siRNA against Nit1 decreased overall cell survival of lung cancer cells in culture. In addition, cisplatin response was enhanced in human lung cancer cells when Nit1 was knocked down and Nit1−/−:KrasG12D/+ tumors showed increased sensitivity to cisplatin in vivo. Together, our data indicate that Nit1 may play a supportive role in the modulation of lung tumorigenesis and represent a novel target for NSCLCs treatment. PMID:26967383

Low Concentration of S100A8/9 Promotes Angiogenesis-Related Activity of Vascular Endothelial Cells: Bridges among Inflammation, Angiogenesis, and Tumorigenesis?

PubMed Central

Li, Changyou; Li, Siyuan; Jia, Changkai; Yang, Lingling; Song, Zicheng; Wang, Yiqiang

2012-01-01

Previous studies showed that several members of the S100A family are involved in neovascularization and tumor development. This study checked whether low concentrations of S100A8 or S100A9 has any effect on the behaviour of vascular endothelial cells. A human umbilical vascular endothelial cell (HUVEC) line was used to measure vascular endothelial cell bioactivity related to angiogenesis, such as cell proliferation, migration, and vessel formation. In the low concentration range up to 10 μg/mL, either each alone or in combination, S100A8 and S100A9 proteins promoted proliferation of HUVEC cells in a dose-dependent manner. The presence of both proteins in culture showed additive effects over each single protein. Both proteins enhanced HUVEC cells to migrate across the transwell membrane and to form tube-like structures on the Matrigel surface. When mixed in Matrigel and injected subcutaneously in Balb/c mice, both proteins increased vessel development in the gel plugs. Microarray assay of HUVEC cells treated with 10 μg/mL S100A8 revealed that ribosome pathway, pathogenic Escherichia coli infection pathway, apoptosis, and stress response genes were modulated by S100A8 treatment. We propose that S100A8 and S100A9 proteins from either infiltrating inflammatory cells or tumor cells play an important role in the interplay among inflammation, angiogenesis, and tumorigenesis. PMID:22685372

MYCN acts as a direct co-regulator of p53 in MYCN amplified neuroblastoma.

PubMed

Agarwal, Saurabh; Milazzo, Giorgio; Rajapakshe, Kimal; Bernardi, Ronald; Chen, Zaowen; Barberi, Eveline; Koster, Jan; Perini, Giovanni; Coarfa, Cristian; Shohet, Jason M

2018-04-17

The MYC oncogenes and p53 have opposing yet interrelated roles in normal development and tumorigenesis. How MYCN expression alters the biology and clinical responsiveness of pediatric neuroblastoma remains poorly defined. Neuroblastoma is p53 wild type at diagnosis and repression of p53 signaling is required for tumorigenesis. Here, we tested the hypothesis that MYCN amplification alters p53 transcriptional activity in neuroblastoma. Interestingly, we found that MYCN directly binds to the tetrameric form of p53 at its C-terminal domain, and this interaction is independent of MYCN/MAX heterodimer formation. Chromatin analysis of MYCN and p53 targets reveals dramatic changes in binding, as well as co-localization of the MYCN-p53 complex at p53-REs and E-boxes of genes critical to DNA damage responses and cell cycle progression. RNA sequencing studies show that MYCN-p53 co-localization significantly modulated the expression of p53 target genes. Furthermore, MYCN-p53 interaction leads to regulation of alternative p53 targets not regulated in the presence of low MYCN levels. These novel targets include a number of genes involved in lipid metabolism, DNA repair, and apoptosis. Taken together, our findings demonstrate a novel oncogenic role of MYCN as a transcriptional co-regulator of p53 in high-risk MYCN amplified neuroblastoma. Targeting this novel oncogenic function of MYCN may enhance p53-mediated responses and sensitize MYCN amplified tumors to chemotherapy.

MiR-141-3p promotes prostate cancer cell proliferation through inhibiting kruppel-like factor-9 expression

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

Li, Jiu-zhi; Department of Urology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang, 830001; Li, Jia

Evidence has revealed that some microRNAs play a critical role in tumor proliferation. We demonstrated that miR-141-3p appears to be a novel oncogene miRNA, which promotes prostate tumorigenesis and facilitates the stemness of prostate cancer cells via suppressing a key transcription factor kruppel-like factor-9 (KLF9). KLF9 is the core effector protein that might suppress tumor growth. MiR-141-3p is upregulated in prostate cancer cells and tissues compared to non-tumorigenic prostate epithelial cells and prostate tissues. MiR-141-3p positively regulated proliferation, spheroid formation, and expression of the stemness factors OCT-4, Nanog, SOX-9, Bmil, CCND1, and CD44 in PC-3 cells. Restoration of miR-141-3p suppresses themore » expression of the transcription factor KLF9 in PC-3 and accelerates prostate tumorigenesis via targeted binding with its 3′-UTR. Downregulation of KLF9 enhances spheres formation of prostate cancer cells. Our results suggest that miR-141-3p/KLF9 may play an important role in regulating the growth of prostate cancer and is a potential target of prevention and therapy. - Highlights: • MiR-141-3p is upregulated in human prostate cancer. • MiR-141-3p induces cell proliferation and apoptosis resistance. • KLF9 is a direct and functional target of miR-141-3p.« less

Inhibition of c-Myc by 10058-F4 induces growth arrest and chemosensitivity in pancreatic ductal adenocarcinoma.

PubMed

Zhang, Meng; Fan, Hai-Yan; Li, Sheng-Chao

2015-07-01

Pancreatic ductal adenocarcinoma (PDAC) is a formidable medical challenge due to its malignancies and the absence of effective treatment. c-Myc, as an important transcription factor, plays crucial roles in cell cycle progression, apoptosis and cellular transformation. The c-Myc inhibitor, 10058-F4, has been reported act as a tumor suppressor in several different tumors. In current study, the tumor-suppressive roles of 10058-F4 was observed in human pancreatic cancer cells in vitro as demonstrated by decreased cell viability, cell cycle arrest at the G1/S transition and increased caspase3/7 activity. And tumor responses to gemcitabine were also significantly enhanced by 10058-F4 in PANC-1 and SW1990 cells. In a subcutaneous xenograft model, however, 10058-F4 showed no significant influence on pancreatic tumorigenesis. When combined with gemcitabine, tumorigenesis was drastically attenuated compared with gemcitabine group or 10058-F4 group; this synergistic effect was accompanied with decreased PCNA-positive cells and reduced TUNEL-positive cells in the combined treated group. Subsequent studies revealed that decreased glycolysis may be involved in the inhibitory effect of 10058-F4 on PDAC. Taken together, this study demonstrates the roles of 10058-F4 in PDAC and provides evidence that 10058-F4 in combination with gemcitabine showed significant clinical benefit over the usage of gemcitabine alone. Copyright © 2015. Published by Elsevier Masson SAS.

Uridine homeostatic disorder leads to DNA damage and tumorigenesis.

PubMed

Cao, Zhe; Ma, Jun; Chen, Xinchun; Zhou, Boping; Cai, Chuan; Huang, Dan; Zhang, Xuewen; Cao, Deliang

2016-03-28

Uridine is a natural nucleoside precursor of uridine monophosphate in organisms and thus is considered to be safe and is used in a wide range of clinical settings. The far-reaching effects of pharmacological uridine have long been neglected. Here, we report that the homeostatic disorder of uridine is carcinogenic. Targeted disruption (-/-) of murine uridine phosphorylase (UPase) disrupted the homeostasis of uridine and increased spontaneous tumorigenesis by more than 3-fold. Multiple tumors (e.g., lymphoma, hepatoma and lung adenoma) occurred simultaneously in some UPase deficient mice, but not in wild-type mice raised under the same conditions. In the tissue from UPase -/- mice, the 2'-deoxyuridine,5'-triphosphate (dUTP) levels and uracil DNA were increased and p53 was activated with an increased phospho-Ser18 p53 level. Exposing cell lines (e.g., MCF-7, RKO, HCT-8 and NCI-H460) to uridine (10 or 30 µM) led to uracil DNA damage and p53 activation, which in turn triggered the DNA damage response. In these cells, phospho-ATM, phospho-CHK2, and phospho-γH2AX were increased by uridine. These data suggest that uridine homeostatic disorder leads to uracil DNA damage and that pharmacological uridine may be carcinogenic. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Disruptive chemicals, senescence and immortality.

PubMed

Carnero, Amancio; Blanco-Aparicio, Carmen; Kondoh, Hiroshi; Lleonart, Matilde E; Martinez-Leal, Juan Fernando; Mondello, Chiara; Scovassi, A Ivana; Bisson, William H; Amedei, Amedeo; Roy, Rabindra; Woodrick, Jordan; Colacci, Annamaria; Vaccari, Monica; Raju, Jayadev; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Salem, Hosni K; Memeo, Lorenzo; Forte, Stefano; Singh, Neetu; Hamid, Roslida A; Ryan, Elizabeth P; Brown, Dustin G; Wise, John Pierce; Wise, Sandra S; Yasaei, Hemad

2015-06-01

Carcinogenesis is thought to be a multistep process, with clonal evolution playing a central role in the process. Clonal evolution involves the repeated 'selection and succession' of rare variant cells that acquire a growth advantage over the remaining cell population through the acquisition of 'driver mutations' enabling a selective advantage in a particular micro-environment. Clonal selection is the driving force behind tumorigenesis and possesses three basic requirements: (i) effective competitive proliferation of the variant clone when compared with its neighboring cells, (ii) acquisition of an indefinite capacity for self-renewal, and (iii) establishment of sufficiently high levels of genetic and epigenetic variability to permit the emergence of rare variants. However, several questions regarding the process of clonal evolution remain. Which cellular processes initiate carcinogenesis in the first place? To what extent are environmental carcinogens responsible for the initiation of clonal evolution? What are the roles of genotoxic and non-genotoxic carcinogens in carcinogenesis? What are the underlying mechanisms responsible for chemical carcinogen-induced cellular immortality? Here, we explore the possible mechanisms of cellular immortalization, the contribution of immortalization to tumorigenesis and the mechanisms by which chemical carcinogens may contribute to these processes. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Somatic Genetic Variation in Solid Pseudopapillary Tumor of the Pancreas by Whole Exome Sequencing

PubMed Central

Guo, Meng; Luo, Guopei; Jin, Kaizhou; Long, Jiang; Cheng, He; Lu, Yu; Wang, Zhengshi; Yang, Chao; Xu, Jin; Ni, Quanxing; Yu, Xianjun; Liu, Chen

2017-01-01

Solid pseudopapillary tumor of the pancreas (SPT) is a rare pancreatic disease with a unique clinical manifestation. Although CTNNB1 gene mutations had been universally reported, genetic variation profiles of SPT are largely unidentified. We conducted whole exome sequencing in nine SPT patients to probe the SPT-specific insertions and deletions (indels) and single nucleotide polymorphisms (SNPs). In total, 54 SNPs and 41 indels of prominent variations were demonstrated through parallel exome sequencing. We detected that CTNNB1 mutations presented throughout all patients studied (100%), and a higher count of SNPs was particularly detected in patients with older age, larger tumor, and metastatic disease. By aggregating 95 detected variation events and viewing the interconnections among each of the genes with variations, CTNNB1 was identified as the core portion in the network, which might collaborate with other events such as variations of USP9X, EP400, HTT, MED12, and PKD1 to regulate tumorigenesis. Pathway analysis showed that the events involved in other cancers had the potential to influence the progression of the SNPs count. Our study revealed an insight into the variation of the gene encoding region underlying solid-pseudopapillary neoplasm tumorigenesis. The detection of these variations might partly reflect the potential molecular mechanism. PMID:28054945

Intricacies of hedgehog signaling pathways: A perspective in tumorigenesis

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

Kar, Swayamsiddha; Deb, Moonmoon; Sengupta, Dipta

The hedgehog (HH) signaling pathway is a crucial negotiator of developmental proceedings in the embryo governing a diverse array of processes including cell proliferation, differentiation, and tissue patterning. The overall activity of the pathway is significantly curtailed after embryogenesis as well as in adults, yet it retains many of its functional capacities. However, aberration in HH signaling mediates the initiation, proliferation and continued sustenance of malignancy in different tissues to varying degrees through different mechanisms. In this review, we provide an overview of the role of constitutively active aberrant HH signaling pathway in different types of human cancer and themore » underlying molecular and genetic mechanisms that drive tumorigenesis in that particular tissue. An insight into the various modes of anomalous HH signaling in different organs will provide a comprehensive knowledge of the pathway in these tissues and open a window for individually tailored, tissue-specific therapeutic interventions. The synergistic cross talking of HH pathway with many other regulatory molecules and developmentally inclined signaling pathways may offer many avenues for pharmacological advances. Understanding the molecular basis of abnormal HH signaling in cancer will provide an opportunity to inhibit the deregulated pathway in many aggressive and therapeutically challenging cancers where promising options are not available.« less

Avian leukosis virus subgroup J promotes cell proliferation and cell cycle progression through miR-221 by targeting CDKN1B.

PubMed

Ren, Chaoqi; Yu, Mengmeng; Zhang, Yao; Fan, Minghui; Chang, Fangfang; Xing, Lixiao; Liu, Yongzhen; Wang, Yongqiang; Qi, Xiaole; Liu, Changjun; Zhang, Yanping; Cui, Hongyu; Li, Kai; Gao, Li; Pan, Qing; Wang, Xiaomei; Gao, Yulong

2018-06-01

Avian leukosis virus subgroup J (ALV-J), a highly oncogenic retrovirus, causes leukemia-like proliferative diseases in chickens. microRNAs post-transcriptionally suppress targets and are involved in the development of various tumors. We previously showed that miR-221 is upregulated in ALV-J-induced tumors. In this study, we analyzed the possible function of miR-221 in ALV-J tumorigenesis. The target validation system showed that CDKN1B is a target of miR-221 and is downregulated in ALV-J infection. As CDKN1B arrests the cell cycle and regulates its progression, we analyzed the proliferation of ALV-J-infected DF-1 cells. ALV-J-infection-induced DF1 cell derepression of G1/S transition and overproliferation required high miR-221 expression followed by CDKN1B downregulation. Cell cycle pathway analysis showed that ALV-J infection induced DF-1 cell overproliferation via the CDKN1B-CDK2/CDK6 pathway. Thus, miR-221 may play an important role in ALV-J-induced aggressive growth of DF-1 cells; these findings have expanded our insights into the mechanism underlying ALV-J infection and tumorigenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

Metformin inhibits early stage diethylnitrosamine-induced hepatocarcinogenesis in rats

PubMed Central

JO, WOORI; YU, EUN-SIL; CHANG, MINSUN; PARK, HYUN-KYU; CHOI, HYUN-JI; RYU, JAE-EUN; JANG, SUNGWOONG; LEE, HYO-JU; JANG, JA-JUNE; SON, WOO-CHAN

2016-01-01

Antitumor effects of metformin have recently emerged despite its original use for type II diabetes. In the present study, the effects of metformin on the development and recurrence of hepatocellular carcinoma (HCC) were investigated using the diethylnitrosamine (DEN)-induced rat model of HCC. Tumor foci were characterized by gross examination and by histopathological characteristics, including proliferation, hepatic progenitor cell content and the expression of hepatocarcinoma-specific molecular markers. Potential target molecules of metformin were investigated to determine the molecular mechanism underlying the inhibitory effects of metformin on chemically induced liver tumorigenesis. The antitumor effects of metformin were increased by the reduction of surface nodules and decreased the incidence of altered hepatocellular foci, hepatocellular adenoma and carcinoma. Also, decreased expression levels of glutathione S-transferase placental form, proliferating cell nuclear antigen and cytokeratin 8 described the inhibitory effects of metformin on HCC. In the present study, Wistar rats receiving treatment with DEN were administered metformin for 16 weeks. In addition, metformin suppressed liver tumorigenesis via an AMPK-dependent pathway. These results suggested that metformin has promising effects on the early stage of HCC in rats. Therefore, metformin may be used for the prevention of HCC recurrence following primary chemotherapy for HCC and/or for high-risk patients, including chronic hepatitis and cirrhosis. PMID:26548419

Downregulation of a mitochondria associated protein SLP-2 inhibits tumor cell motility, proliferation and enhances cell sensitivity to chemotherapeutic reagents.

PubMed

Wang, Yueqi; Cao, Wenfeng; Yu, Zaicheng; Liu, Zhihua

2009-09-01

Results from tissue microarray in this study and our previous reports revealed that stomatin-like protein 2 (SLP-2) is notably associated with tumorigenesis and metastasis. Many members of stomatin family are involved in tumor as mitochondrial component, and recent study has revealed that SLP-2 may also function in mitochondria. To further investigate the function of SLP-2, we used siRNA target SLP-2. Data showed that knock-down of SLP-2 potently inhibited cell motility, proliferation and slightly altered cell cycle without any significant change of apoptosis. Moreover, by combined application with different chemotherapeutic reagents, we observed the enhancement of cell chemosensitivity by SLP-2 depletion. We also confirmed that, SLP-2 localizes in mitochondria, affects mitochondrial membrane potential (MMP) and ATP production. We conclude that, SLP-2 is a mitochondrial protein and therefore, functions in energy process by MMP maintenance, and subsequently affecting cell motility, proliferation and chemosensitivity.

Targeting estrogen/estrogen receptor alpha enhances Bacillus Calmette-Guérin efficacy in bladder cancer

PubMed Central

Shang, Zhiqun; Li, Yanjun; Hsu, Iawen; Zhang, Minghao; Tian, Jing; Wen, Simeng; Han, Ruifa; Messing, Edward M.; Chang, Chawnshang; Niu, Yuanjie; Yeh, Shuyuan

2016-01-01

Recent studies showed the potential linkage of estrogen/estrogen receptor signaling with bladder tumorigenesis, yet detailed mechanisms remain elusive. Here we found a new potential therapy with the combination of Bacillus Calmette Guerin (BCG) and the anti-estrogen ICI 182,780 led to better suppression of bladder cancer (BCa) than BCG alone. Mechanism dissection found ICI 182,780 could promote BCG attachment/internalization to the BCa cells through increased integrin-α5β1 expression and IL-6 release, which may enhance BCG-induced suppression of BCa cell growth via recruiting more monocytes/macrophages to BCa cells and increased TNF-α release. Consistently, in vivo studies found ICI 182,780 could potentiate the anti-BCa effects of BCG in the carcinogen-induced mouse BCa models. Together, these in vitro and in vivo results suggest that combining BCG with anti-estrogen may become a new therapeutic approach with better efficacy to suppress BCa progression and recurrence. PMID:27092883

Targeting estrogen/estrogen receptor alpha enhances Bacillus Calmette-Guérin efficacy in bladder cancer.

PubMed

Shang, Zhiqun; Li, Yanjun; Hsu, Iawen; Zhang, Minghao; Tian, Jing; Wen, Simeng; Han, Ruifa; Messing, Edward M; Chang, Chawnshang; Niu, Yuanjie; Yeh, Shuyuan

2016-05-10

Recent studies showed the potential linkage of estrogen/estrogen receptor signaling with bladder tumorigenesis, yet detailed mechanisms remain elusive. Here we found a new potential therapy with the combination of Bacillus Calmette-Guerin (BCG) and the anti-estrogen ICI 182,780 led to better suppression of bladder cancer (BCa) than BCG alone. Mechanism dissection found ICI 182,780 could promote BCG attachment/internalization to the BCa cells through increased integrin-α5β1 expression and IL-6 release, which may enhance BCG-induced suppression of BCa cell growth via recruiting more monocytes/macrophages to BCa cells and increased TNF-α release. Consistently, in vivo studies found ICI 182,780 could potentiate the anti-BCa effects of BCG in the carcinogen-induced mouse BCa models. Together, these in vitro and in vivo results suggest that combining BCG with anti-estrogen may become a new therapeutic approach with better efficacy to suppress BCa progression and recurrence.

Multifaceted Leptin network: the molecular connection between obesity and breast cancer

PubMed Central

Saxena, Neeraj K.; Sharma, Dipali

2016-01-01

High plasma levels of leptin, a major adipocytokine produced by adipocytes, are correlated with increased fat mass in obese state. Leptin is emerging as a key candidate molecule linking obesity with breast cancer. Acting via endocrine, paracrine, and autocrine manner, leptin impacts various stages of breast tumorigenesis from initiation and primary tumor growth to metastatic progression. Leptin also modulates the tumor microenvironment mainly through supporting migration of endothelial cells, neo-angiogenesis and sustaining recruitment of macrophage and monocytes. Various studies have shown that hyperactive leptin-signaling network leads to concurrent activation of multiple oncogenic pathways resulting in enhanced proliferation, decreased apoptosis, acquisition of mesenchymal phenotype, potentiated migration and enhanced invasion potential of tumor cells. Furthermore, the capability of leptin to interact with other molecular effectors of obese state including, estrogen, IGF-1, insulin, VEGF and inflammatory cytokines further increases its impact on breast tumor progression in obese state. This article presents an overview of the studies investigating the involvement of leptin in breast cancer. PMID:24214584

Isoliquiritigenin, a flavonoid from licorice, blocks M2 macrophage polarization in colitis-associated tumorigenesis through downregulating PGE{sub 2} and IL-6

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

Zhao, Haixia; Zhang, Xinhua; Chen, Xuewei

M2 macrophage polarization is implicated in colorectal cancer development. Isoliquiritigenin (ISL), a flavonoid from licorice, has been reported to prevent azoxymethane (AOM) induced colon carcinogenesis in animal models. Here, in a mouse model of colitis-associated tumorigenesis induced by AOM/dextran sodium sulfate (DSS), we investigated the chemopreventive effects of ISL and its mechanisms of action. Mice were treated with AOM/DSS and randomized to receive either vehicle or ISL (3, 15 and 75 mg/kg). Tumor load, histology, immunohistochemistry, and gene and protein expressions were determined. Intragastric administration of ISL for 12 weeks significantly decreased colon cancer incidence, multiplicity and tumor size bymore » 60%, 55.4% and 42.6%, respectively. Moreover, ISL inhibited M2 macrophage polarization. Such changes were accompanied by downregulation of PGE{sub 2} and IL-6 signaling. Importantly, depletion of macrophages by clodronate (Clod) or zoledronic acid (ZA) reversed the effects of ISL. In parallel, in vitro studies also demonstrated that ISL limited the M2 polarization of RAW264.7 cells and mouse peritoneal macrophages with concomitant inactivation of PGE{sub 2}/PPARδ and IL-6/STAT3 signaling. Conversely, exogenous addition of PGE{sub 2} or IL-6, or overexpression of constitutively active STAT3 reversed ISL-mediated inhibition of M2 macrophage polarization. In summary, dietary flavonoid ISL effectively inhibits colitis-associated tumorigenesis through hampering M2 macrophage polarization mediated by the interplay between PGE{sub 2} and IL-6. Thus, inhibition of M2 macrophage polarization is likely to represent a promising strategy for chemoprevention of colorectal cancer. - Highlights: • Isoliquiritigenin (ISL) prevents colitis-associated tumorigenesis. • ISL inhibits M2 macrophage polarization in vivo and in vitro. • ISL inhibits PGE{sub 2} and IL-6 signaling in colitis-associated tumorigenesis. • ISL may be an attractive candidate agent for chemoprevention of colorectal cancer.« less

[Stem cells--cloning, plasticity, bioethic].

PubMed

Pflegerl, Pamina; Keller, Thomas; Hantusch, Brigitte; Hoffmann, Thomas Sören; Kenner, Lukas

2008-01-01

Stem cells with certain characteristics have become promising tools for molecular medicine. They have the potential to self-regenerate and to differentiate into specific tissues. Besides their great potential, embryonic stem cells (ESC) run the risk of enhanced tumorigenesis. The use of human embryonic stem cells (hESC) is ethically problematic because their isolation involves the destruction of human embryos. Recently developed methods generate are able to pluripotent stem cells from fibroblasts. Alternatives for ESC are adult stem cells (ASC) derived from bone marrow, cord blood, amniotic fluid and other tissues. The following article is on the basis of testimony of Lukas Kenner for the German Bundestag about the use of ESC for research, therapy and drug development. Ethical aspects are taken into consideration.

The Role of Ferroptosis in Cancer Development and Treatment Response.

PubMed

Lu, Bin; Chen, Xiao Bing; Ying, Mei Dan; He, Qiao Jun; Cao, Ji; Yang, Bo

2017-01-01

Ferroptosis is a process driven by accumulated iron-dependent lipid ROS that leads to cell death, which is a distinct regulated cell death comparing to other cell death. The lethal metabolic imbalance resulted from GSH depletion or inactivation of glutathione peroxidase 4 is the executor of ferroptosis within the cancer cell. Small molecules-induced ferroptosis has a strong inhibition of tumor growth and enhances the sensitivity of chemotherapeutic drugs, especially in the condition of drug resistance. These evidences have highlighted the importance of ferroptosis in cancer therapeutics, but the roles of ferroptosis in tumorigenesis and development remain unclear. This article provides an overview of the mechanisms of ferroptosis, highlights the role of ferroptosis in cancer and discusses strategies for therapeutic modulation.

Ras-Directed N-Glycoproteins Are Novel Early Biomarkers for Tumorigenesis and Malignant Transformation and Therapeutic Targets of Neurofibromatosis Type 1

DTIC Science & Technology

2014-08-01

phosphorylates Ser192 in MGAT5B in MPNST cells. Moreover, wild type MGAT5B protein locates in the Golgi apparatus whereas mutated MGAT5BS192A protein...to the Golgi apparatus to attenuate MGAT5B-mediated glycosylation and phosphorylation of kinase receptors. Targeting MGAT5-mediated glycosylation of...tumorigenesis in Nf1+/-;p53+/- mice (bottom). Because proteins travelling to the Golgi apparatus for the consequent steps of glycosylation must be

Geminin deficiency enhances survival in a murine medulloblastoma model by inducing apoptosis of preneoplastic granule neuron precursors

PubMed Central

Sankar, Savita; Patterson, Ethan; Lewis, Emily M.; Waller, Laura E.; Tong, Caili; Dearborn, Joshua; Wozniak, David; Rubin, Joshua B.; Kroll, Kristen L.

2017-01-01

Medulloblastoma is the most common malignant brain cancer of childhood. Further understanding of tumorigenic mechanisms may define new therapeutic targets. Geminin maintains genome fidelity by controlling re-initiation of DNA replication within a cell cycle. In some contexts, Geminin inhibition induces cancer-selective cell cycle arrest and apoptosis and/or sensitizes cancer cells to Topoisomerase IIα inhibitors such as etoposide, which is used in combination chemotherapies for medulloblastoma. However, Geminin's potential role in medulloblastoma tumorigenesis remained undefined. Here, we found that Geminin is highly expressed in human and mouse medulloblastomas and in murine granule neuron precursor (GNP) cells during cerebellar development. Conditional Geminin loss significantly enhanced survival in the SmoA1 mouse medulloblastoma model. Geminin loss in this model also reduced numbers of preneoplastic GNPs persisting at one postnatal month, while at two postnatal weeks these cells exhibited an elevated DNA damage response and apoptosis. Geminin knockdown likewise impaired human medulloblastoma cell growth, activating G2 checkpoint and DNA damage response pathways, triggering spontaneous apoptosis, and enhancing G2 accumulation of cells in response to etoposide treatment. Together, these data suggest preneoplastic and cancer cell-selective roles for Geminin in medulloblastoma, and suggest that targeting Geminin may impair tumor growth and enhance responsiveness to Topoisomerase IIα-directed chemotherapies. PMID:29234490

Chemopreventive and therapeutic activity of dietary blueberry against estrogen-mediated breast cancer.

PubMed

Jeyabalan, Jeyaprakash; Aqil, Farrukh; Munagala, Radha; Annamalai, Lakshmanan; Vadhanam, Manicka V; Gupta, Ramesh C

2014-05-07

Berries are gaining increasing importance lately for their chemopreventive and therapeutic potential against several cancers. In earlier studies, a blueberry-supplemented diet has shown protection against 17β-estradiol (E2)-mediated mammary tumorigenesis. This study tested both preventive and therapeutic activities of diet supplemented with whole blueberry powder (50:50 blend of Tifblue and Rubel). Animals received 5% blueberry diet, either 2 weeks prior to or 12 weeks after E2 treatment in preventive and therapeutic groups, respectively. Both interventions delayed the tumor latency for palpable mammary tumors by 28 and 37 days, respectively. Tumor volume and multiplicity were also reduced significantly in both modes. The effect on mammary tumorigenesis was largely due to down-regulation of CYP 1A1 and ER-α gene expression and also favorable modulation of microRNA (miR-18a and miR-34c) levels. These data suggest that the blueberry blend tested is effective in inhibiting E2-mediated mammary tumorigenesis in both preventive and therapeutic modes.

A tumor suppressor role of the Bub3 spindle checkpoint protein after apoptosis inhibition

PubMed Central

Moutinho-Santos, Tatiana

2013-01-01

Most solid tumors contain aneuploid cells, indicating that the mitotic checkpoint is permissive to the proliferation of chromosomally aberrant cells. However, mutated or altered expression of mitotic checkpoint genes accounts for a minor proportion of human tumors. We describe a Drosophila melanogaster tumorigenesis model derived from knocking down spindle assembly checkpoint (SAC) genes and preventing apoptosis in wing imaginal discs. Bub3-deficient tumors that were also deficient in apoptosis displayed neoplastic growth, chromosomal aneuploidy, and high proliferative potential after transplantation into adult flies. Inducing aneuploidy by knocking down CENP-E and preventing apoptosis does not induce tumorigenesis, indicating that aneuploidy is not sufficient for hyperplasia. In this system, the aneuploidy caused by a deficient SAC is not driving tumorigenesis because preventing Bub3 from binding to the kinetochore does not cause hyperproliferation. Our data suggest that Bub3 has a nonkinetochore-dependent function that is consistent with its role as a tumor suppressor. PMID:23609535

Emerging role of Hippo pathway in gastric and other gastrointestinal cancers.

PubMed

Kang, Wei; Cheng, Alfred S L; Yu, Jun; To, Ka Fai

2016-01-21

More evidence has underscored the importance of Hippo signaling pathway in gastrointestinal tissue homeostasis, whereas its deregulation induces tumorigenesis. Yes-associated protein 1 (YAP1) and its close paralog TAZ, transcriptional co-activator with a PDZ-binding motif, function as key effectors negatively controlled by the Hippo pathway. YAP1/TAZ exerts oncogenic activities by transcriptional regulation via physical interaction with TEAD transcription factors. In various cancers, Hippo pathway cross-talks with pro- or anti-tumorigenic pathways such as GPCR, Wnt/β-catenin, Notch and TGF-β signaling and is deregulated by multiple factors including cell density/junction and microRNAs. As YAP1 expression is significantly associated with poor prognosis of gastric and other gastrointestinal cancers, detailed delineation of Hippo regulation in tumorigenesis provides novel insight for therapeutic intervention. In current review, we summarized the recent research progresses on the deregulation of Hippo pathway in the gastrointestinal tract including stomach and discuss the molecular consequences leading to tumorigenesis.

Examples of Mathematical Modeling

PubMed Central

Johnston, Matthew D.; Edwards, Carina M.; Bodmer, Walter F.; Maini, Philip K.; Chapman, S. Jonathan

2008-01-01

Mathematical modeling is being increasingly recognized within the biomedical sciences as an important tool that can aid the understanding of biological systems. The heavily regulated cell renewal cycle in the colonic crypt provides a good example of how modeling can be used to find out key features of the system kinetics, and help to explain both the breakdown of homeostasis and the initiation of tumorigenesis. We use the cell population model by Johnston et al.5 to illustrate the power of mathematical modeling by considering two key questions about the cell population dynamics in the colonic crypt. We ask: how can a model describe both homeostasis and unregulated growth in tumorigenesis; and to which parameters in the system is the model most sensitive? In order to address these questions, we discuss what type of modeling approach is most appropriate in the crypt. We use the model to argue why tumorigenesis is observed to occur in stages with long lag phases between periods of rapid growth, and we identify the key parameters. PMID:17873520

An important role for Myb-MuvB and its target gene KIF23 in a mouse model of lung adenocarcinoma.

PubMed

Iltzsche, F; Simon, K; Stopp, S; Pattschull, G; Francke, S; Wolter, P; Hauser, S; Murphy, D J; Garcia, P; Rosenwald, A; Gaubatz, S

2017-01-05

The conserved Myb-MuvB (MMB) multiprotein complex has an important role in transcriptional activation of mitotic genes. MMB target genes are overexpressed in several different cancer types and their elevated expression is associated with an advanced tumor state and a poor prognosis. This suggests that MMB could contribute to tumorigenesis by mediating overexpression of mitotic genes. However, although MMB has been extensively characterized biochemically, the requirement for MMB in tumorigenesis in vivo has not been investigated. Here we demonstrate that MMB is required for tumor formation in a mouse model of lung cancer driven by oncogenic K-RAS. We also identify a requirement for the mitotic kinesin KIF23, a key target gene of MMB, in tumorigenesis. RNA interference-mediated depletion of KIF23 inhibited lung tumor formation in vivo and induced apoptosis in lung cancer cell lines. Our results suggest that inhibition of KIF23 could be a strategy for treatment of lung cancer.

Effects of space flight exposure on cell growth, tumorigenicity and gene expression in cancer cells

NASA Astrophysics Data System (ADS)

Yang, Cheng; Li, Yuehui; Zhang, Zhijie; Luo, Chen; Tong, Yongqing; Zhou, Guohua; Xie, Pingli; Hu, Jinyue; Li, Guancheng

2008-12-01

It is well recognized that harsh outer space environment, consisting of microgravity and radiation, poses significant health risks for human cells. To investigate potential effects of the space environment exposure on cancer cells we examined the biological changes in Caski cells carried by the "Shen Zhou IV" spaceship. After exposure for 7 days in spaceflight, 1440 survival subclonal cell lines were established and 4 cell lines were screened. 44F10 and 17E3 were selected because of their increased cell proliferation and tumorigenesis, while 48A9 and 31F2 had slower cytological events. Experiments with cell proliferation assay, flow cytometry, soft agar assay, tumorigenesis assay and DNA microarray analysis have shown that selected cell lines presented multiple biological changes in cell morphology, cell growth, tumorigenicity and gene expression. These results suggest that space environment exposure can make significant biological impact on cancer cells and provide an entry point to find the immunological target of tumorigenesis.

Rho-associated kinase (ROCK) function is essential for cell cycle progression, senescence and tumorigenesis.

PubMed

Kümper, Sandra; Mardakheh, Faraz K; McCarthy, Afshan; Yeo, Maggie; Stamp, Gordon W; Paul, Angela; Worboys, Jonathan; Sadok, Amine; Jørgensen, Claus; Guichard, Sabrina; Marshall, Christopher J

2016-01-14

Rho-associated kinases 1 and 2 (ROCK1/2) are Rho-GTPase effectors that control key aspects of the actin cytoskeleton, but their role in proliferation and cancer initiation or progression is not known. Here, we provide evidence that ROCK1 and ROCK2 act redundantly to maintain actomyosin contractility and cell proliferation and that their loss leads to cell-cycle arrest and cellular senescence. This phenotype arises from down-regulation of the essential cell-cycle proteins CyclinA, CKS1 and CDK1. Accordingly, while the loss of either Rock1 or Rock2 had no negative impact on tumorigenesis in mouse models of non-small cell lung cancer and melanoma, loss of both blocked tumor formation, as no tumors arise in which both Rock1 and Rock2 have been genetically deleted. Our results reveal an indispensable role for ROCK, yet redundant role for isoforms 1 and 2, in cell cycle progression and tumorigenesis, possibly through the maintenance of cellular contractility.

Senescence marker protein 30 (SMP30)/regucalcin (RGN) expression decreases with aging, acute liver injuries and tumors in zebrafish

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

Fujisawa, Koichi; Terai, Shuji, E-mail: terais@yamaguchi-u.ac.jp; Hirose, Yoshikazu

2011-10-22

Highlights: {yields} Zebrafish SMP30/RGN mRNA expression decreases with aging. {yields} Decreased expression was observed in liver tumors as compared to the surrounding area. {yields} SMP30/RGN is important for liver proliferation and tumorigenesis. -- Abstract: Senescence marker protein 30 (SMP30)/regucalcin (RGN) is known to be related to aging, hepatocyte proliferation and tumorigenesis. However, expression and function of non-mammalian SMP30/RGN is poorly understood. We found that zebrafish SMP30/RGN mRNA expression decreases with aging, partial hepatectomy and thioacetamide-induced acute liver injury. SMP30/RGN expression was also greatly decreased in a zebrafish liver cell line. In addition, we induced liver tumors in adult zebrafish bymore » administering diethylnitrosamine. Decreased expression was observed in foci, hepatocellular carcinomas, cholangiocellular carcinomas and mixed tumors as compared to the surrounding area. We thus showed the importance of SMP30/RGN in liver proliferation and tumorigenesis.« less

Mbd3/NuRD controls lymphoid cell fate and inhibits tumorigenesis by repressing a B cell transcriptional program

PubMed Central

Hamey, Fiona K.; Errami, Youssef

2017-01-01

Differentiation of lineage-committed cells from multipotent progenitors requires the establishment of accessible chromatin at lineage-specific transcriptional enhancers and promoters, which is mediated by pioneer transcription factors that recruit activating chromatin remodeling complexes. Here we show that the Mbd3/nucleosome remodeling and deacetylation (NuRD) chromatin remodeling complex opposes this transcriptional pioneering during B cell programming of multipotent lymphoid progenitors by restricting chromatin accessibility at B cell enhancers and promoters. Mbd3/NuRD-deficient lymphoid progenitors therefore prematurely activate a B cell transcriptional program and are biased toward overproduction of pro–B cells at the expense of T cell progenitors. The striking reduction in early thymic T cell progenitors results in compensatory hyperproliferation of immature thymocytes and development of T cell lymphoma. Our results reveal that Mbd3/NuRD can regulate multilineage differentiation by constraining the activation of dormant lineage-specific enhancers and promoters. In this way, Mbd3/NuRD protects the multipotency of lymphoid progenitors, preventing B cell–programming transcription factors from prematurely enacting lineage commitment. Mbd3/NuRD therefore controls the fate of lymphoid progenitors, ensuring appropriate production of lineage-committed progeny and suppressing tumor formation. PMID:28899870

PAR1 participates in the ability of multidrug resistance and tumorigenesis by controlling Hippo-YAP pathway.

PubMed

Fujimoto, Daisuke; Ueda, Yuki; Hirono, Yasuo; Goi, Takanori; Yamaguchi, Akio

2015-10-27

The Hippo pathway significantly correlates with organ size control and tumorigenesis. The activity of YAP/TAZ, a transducer of the Hippo pathway, is required to sustain self-renewal and tumor-initiation capacities in cancer stem cells (CSCs). But, upstream signals that control the mammalian Hippo pathway have not been well understood. Here, we reveal a connection between the Protease-activated receptor 1 (PAR1) signaling pathway and the Hippo-YAP pathway in gastric cancer stem-like cells. The selective PAR1 agonist TFLLR-NH2 induces an increase in the fraction of side population cells which is enriched in CSCs, and promotes tumorigenesis, multi cancer drug resistance, cell morphological change, and cell invasion which are characteristics of CSCs. In addition, PAR1 activation inhibits the Hippo-YAP pathway kinase Lats via Rho GTPase. Lats kinase inhibition in turn results in increased nuclear localization of dephosphorylated YAP. Furthermore, PAR1 activation confers CSCs related traits via the Hippo-YAP pathway, and the Hippo-YAP pathway correlates with epithelial mesenchymal transition which is induced by PAR1 activation. Our research suggests that the PAR1 signaling deeply participates in the ability of multi drug resistance and tumorigenesis through interactions with the Hippo-YAP pathway signaling in gastric cancer stem-like cells. We presume that inhibited YAP is a new therapeutic target in the treatment human gastric cancer invasion and metastasis by dysregulated PAR1 or its agonists.

Disruption of the RP-MDM2-p53 pathway accelerates APC loss-induced colorectal tumorigenesis.

PubMed

Liu, S; Tackmann, N R; Yang, J; Zhang, Y

2017-03-01

Inactivation of the adenomatous polyposis coli (APC) tumor suppressor is frequently found in colorectal cancer. Loss of APC function results in deregulation of the Wnt/β-catenin signaling pathway causing overexpression of the c-MYC oncogene. In lymphoma, both p19ARF and ribosomal proteins RPL11 and RPL5 respond to c-MYC activation to induce p53. Their role in c-MYC-driven colorectal carcinogenesis is unclear, as p19ARF deletion does not accelerate APC loss-triggered intestinal tumorigenesis. To determine the contribution of the ribosomal protein (RP)-murine double minute 2 (MDM2)-p53 pathway to APC loss-induced tumorigenesis, we crossed mice bearing MDM2 C305F mutation, which disrupts RPL11- and RPL5-MDM2 binding, with Apc min/+ mice, which are prone to intestinal tumor formation. Interestingly, loss of RP-MDM2 binding significantly accelerated colorectal tumor formation while having no discernable effect on small intestinal tumor formation. Mechanistically, APC loss leads to overexpression of c-MYC, RPL11 and RPL5 in mouse colonic tumor cells irrespective of MDM2 C305F mutation. However, notable p53 stabilization and activation were observed only in Apc min/+ ;Mdm2 +/+ but not Apc min/+ ;Mdm2 C305F/C305F colon tumors. These data establish that the RP-MDM2-p53 pathway, in contrast to the p19ARF-MDM2-p53 pathway, is a critical mediator of colorectal tumorigenesis following APC loss.

Combination of hTERT knockdown and interferon-γ treatment inhibited angiogenesis and tumor progression in glioblastoma

PubMed Central

George, Joseph; Banik, Naren L.; Ray, Swapan K.

2009-01-01

Purpose The limitless invasive and proliferative capacities of tumor cells are associated with telomerase and expression of its catalytic component, human telomerase reverse transcriptase (hTERT). Interferon-γ (IFN-γ) modulates several cellular activities including signaling pathways and cell cycle through transcriptional regulation. Experimental Design Using a recombinant plasmid with hTERT siRNA cDNA, we down regulated hTERT during IFN-γ treatment in human glioblastoma SNB-19 and LN-18 cell lines and examined whether such a combination could inhibit angiogenesis and tumor growth in nude mice. In vitro angiogenesis assay was performed using co-culture of tumor cells with human microvascular endothelial cells. In vivo angiogenesis assay was performed using diffusion chambers under the dorsal skin of nude mice. In vivo imaging of intracerebral tumorigenesis and longitudinal solid tumor development studies were conducted in nude mice. Results In vitro and in vivo angiogenesis assays demonstrated inhibition of capillary-like network formation of microvascular endothelial cells and neovascularization under dorsal skin of nude mice, respectively. We observed inhibition of intracerebral tumorigenesis and subcutaneous solid tumor formation in nude mice after treatment with combination of hTERT siRNA and IFN-γ. Western blotting of solid tumor samples demonstrated significant down regulation of the molecules that regulate cell invasion, angiogenesis, and tumor progression. Conclusions Our study demonstrated that combination of hTERT siRNA and IFN-γ effectively inhibited angiogenesis and tumor progression through down regulation of molecules involved in these processes. Therefore, combination of hTERT siRNA and IFN-γ is a promising therapeutic strategy for controlling growth of human glioblastoma. PMID:19934306

TRB3 reverses chemotherapy resistance and mediates crosstalk between endoplasmic reticulum stress and AKT signaling pathways in MHCC97H human hepatocellular carcinoma cells.

PubMed

Li, Yang; Zhu, Danxi; Hou, Lidan; Hu, Bin; Xu, Min; Meng, Xiangjun

2018-01-01

Tribbles homolog 3 (TRB3), a type of pseudokinase that contains a consensus serine/threonine kinase catalytic core structure, is upregulated in hepatocellular carcinoma. However, the effect of TRB3 expression in hepatocellular carcinoma and the molecular mechanisms underlying TRB3-mediated effects on tumorigenesis in hepatocellular carcinoma have not been fully elucidated. The present study focused on the effect of TRB3 expression in MHCC97H hepatocellular carcinoma cells and investigated the underlying molecular mechanisms in MHCC97H cells. In the present study, it was revealed that TRB3 was significantly overexpressed in the MHCC97H hepatocellular carcinoma cell compared with L-02 normal hepatic cells. Under endoplasmic reticulum (ER) stress induced by thapsigargin and tunicamycin, the levels of TRB3, CCAAT/enhancer binding protein homologous protein (CHOP), protein kinase B (AKT) and phosphorylated (p)AKT expression were upregulated. Furthermore, when the expression of TRB3 was silenced by short hairpin (sh)RNA, the survival of MHCC97H hepatocellular carcinoma cells was increased. Notably, following transduction with lentiviral containing TRB3-shRNA, cell survival also increased after treatment with chemotherapy drug cisplatin. The present study demonstrated that knockdown of CHOP by shRNA was able to reduce TRB3 expression, and the knockdown of TRB3 markedly increased the level of pAKT. TRB3 was overexpressed in MHCC97H hepatocellular carcinoma cells, particularly under endoplasmic reticulum stress. Knockdown of TRB3 was able to increase cell survival. Therefore, TRB3 expression may induce apoptosis and reverse resistance to chemotherapy in MHCC97H hepatic carcinoma cells. The present study suggests that TRB3 is a key molecule that mediates the crosstalk between ER stress and AKT signal pathways. Furthermore, the present study may provide further insight into the cancer biology of hepatocellular carcinoma and the development of anticancer drugs targeting the ER stress and AKT signaling pathways.

In vivo regulation of colonic cell proliferation, differentiation, apoptosis, and P27Kip1 by dietary fish oil and butyrate in rats.

PubMed

Hong, Mee Young; Turner, Nancy D; Murphy, Mary E; Carroll, Raymond J; Chapkin, Robert S; Lupton, Joanne R

2015-11-01

We have shown that dietary fish oil is protective against experimentally induced colon cancer, and the protective effect is enhanced by coadministration of pectin. However, the underlying mechanisms have not been fully elucidated. We hypothesized that fish oil with butyrate, a pectin fermentation product, protects against colon cancer initiation by decreasing cell proliferation and increasing differentiation and apoptosis through a p27(Kip1)-mediated mechanism. Rats were provided diets of corn or fish oil, with/without butyrate, and terminated 12, 24, or 48 hours after azoxymethane (AOM) injection. Proliferation (Ki-67), differentiation (Dolichos Biflorus Agglutinin), apoptosis (TUNEL), and p27(Kip1) (cell-cycle mediator) were measured in the same cell within crypts in order to examine the coordination of cell cycle as a function of diet. DNA damage (N(7)-methylguanine) was determined by quantitative IHC analysis. Dietary fish oil decreased DNA damage by 19% (P = 0.001) and proliferation by 50% (P = 0.003) and increased differentiation by 56% (P = 0.039) compared with corn oil. When combined with butyrate, fish oil enhanced apoptosis 24 hours after AOM injection compared with a corn oil/butyrate diet (P = 0.039). There was an inverse relationship between crypt height and apoptosis in the fish oil/butyrate group (r = -0.53, P = 0.040). The corn oil/butyrate group showed a positive correlation between p27(Kip1) expression and proliferation (r = 0.61, P = 0.035). These results indicate the in vivo effect of butyrate on apoptosis and proliferation is dependent on dietary lipid source. These results demonstrate the presence of an early coordinated colonocyte response by which fish oil and butyrate protects against colon tumorigenesis. ©2015 American Association for Cancer Research.

Low-Dose Alkylphenol Exposure Promotes Mammary Epithelium Alterations and Transgenerational Developmental Defects, But Does Not Enhance Tumorigenic Behavior of Breast Cancer Cells

PubMed Central

Chamard-Jovenin, Clémence; Thiebaut, Charlène; Chesnel, Amand; Bresso, Emmanuel; Morel, Chloé; Smail-Tabbone, Malika; Devignes, Marie-Dominique; Boukhobza, Taha; Dumond, Hélène

2017-01-01

Fetal and neonatal exposure to long-chain alkylphenols has been suspected to promote breast developmental disorders and consequently to increase breast cancer risk. However, disease predisposition from developmental exposures remains unclear. In this work, human MCF-10A mammary epithelial cells were exposed in vitro to a low dose of a realistic (4-nonylphenol + 4-tert-octylphenol) mixture. Transcriptome and cell-phenotype analyses combined to functional and signaling network modeling indicated that long-chain alkylphenols triggered enhanced proliferation, migration ability, and apoptosis resistance and shed light on the underlying molecular mechanisms which involved the human estrogen receptor alpha 36 (ERα36) variant. A male mouse-inherited transgenerational model of exposure to three environmentally relevant doses of the alkylphenol mix was set up in order to determine whether and how it would impact on mammary gland architecture. Mammary glands from F3 progeny obtained after intrabuccal chronic exposure of C57BL/6J P0 pregnant mice followed by F1–F3 male inheritance displayed an altered histology which correlated with the phenotypes observed in vitro in human mammary epithelial cells. Since cellular phenotypes are similar in vivo and in vitro and involve the unique ERα36 human variant, such consequences of alkylphenol exposure could be extrapolated from mouse model to human. However, transient alkylphenol treatments combined to ERα36 overexpression in mammary epithelial cells were not sufficient to trigger tumorigenesis in xenografted Nude mice. Therefore, it remains to be determined if low-dose alkylphenol transgenerational exposure and subsequent abnormal mammary gland development could account for an increased breast cancer susceptibility. PMID:29109696

γ-Glutamyl transferase 7 is a novel regulator of glioblastoma growth.

PubMed

Bui, Timothy T; Nitta, Ryan T; Kahn, Suzana A; Razavi, Seyed-Mostafa; Agarwal, Maya; Aujla, Parvir; Gholamin, Sharareh; Recht, Lawrence; Li, Gordon

2015-04-07

Glioblastoma (GBM) is the most malignant primary brain tumor in adults, with a median survival time of one and a half years. Traditional treatments, including radiation, chemotherapy, and surgery, are not curative, making it imperative to find more effective treatments for this lethal disease. γ-Glutamyl transferase (GGT) is a family of enzymes that was shown to control crucial redox-sensitive functions and to regulate the balance between proliferation and apoptosis. GGT7 is a novel GGT family member that is highly expressed in brain and was previously shown to have decreased expression in gliomas. Since other members of the GGT family were found to be altered in a variety of cancers, we hypothesized that GGT7 could regulate GBM growth and formation. To determine if GGT7 is involved in GBM tumorigenesis, we modulated GGT7 expression in two GBM cell lines (U87-MG and U138) and monitored changes in tumorigenicity in vitro and in vivo. We demonstrated for the first time that GBM patients with low GGT7 expression had a worse prognosis and that 87% (7/8) of primary GBM tissue samples showed a 2-fold decrease in GGT7 expression compared to normal brain samples. Exogenous expression of GGT7 resulted in a 2- to 3-fold reduction in proliferation and anchorage-independent growth under minimal growth conditions (1% serum). Decreasing GGT7 expression using either short interfering RNA or short hairpin RNA consistently increased proliferation 1.5- to 2-fold. In addition, intracranial injections of U87-MG cells with reduced GGT7 expression increased tumor growth in mice approximately 2-fold, and decreased mouse survival. To elucidate the mechanism by which GGT7 regulates GBM growth, we analyzed reactive oxygen species (ROS) levels in GBM cells with modulated GGT7 expression. We found that enhanced GGT7 expression reduced ROS levels by 11-33%. Our study demonstrates that GGT7 is a novel player in GBM growth and that GGT7 can play a critical role in tumorigenesis by regulating anti-oxidative damage. Loss of GGT7 may increase the cellular ROS levels, inducing GBM occurrence and growth. Our findings suggest that GGT7 can be a promising biomarker and a potential therapeutic target for GBM.

Oncogene-Induced Changes in Mammary Cell Fate and EMT in Breast Tumorigenesis

DTIC Science & Technology

2015-04-01

have worked on the project? Name: Lauren Walheim Project Role: Chemistry pre-medicine undergraduate student Researcher Identifier (e.g. ORCID ID...Distribution Unlimited The views, opinions and/or findings contained in this report are those of the author( s ) and should not be construed as an...Examine if IGF1R alters mammary cell fate in vivo and the effect this has on mammary tumorigenesis (months 13-30) ...…………………………………………….......11 2a

Adducin in tumorigenesis and metastasis.

PubMed

Luo, Cong; Shen, Jiayu

2017-07-18

Adducin is a membrane-skeletal protein localized at spectrin-actin junctions, involving in the formation of the network of cytoskeleton, cellular signal transduction, ionic transportation, cell motility and cell proliferation. While previous researches focused mainly on the relationship between adducin and hypertension, there are few studies focusing on the role of adducin in tumor. Previous studies showed that adducin played a role in the evolution and progression of neoplasm. This review makes a brief summary on the structure, function and mechanism of adducin and how adducin functions in tumorigenesis and metastasis.

Predictive genomics: a cancer hallmark network framework for predicting tumor clinical phenotypes using genome sequencing data.

PubMed

Wang, Edwin; Zaman, Naif; Mcgee, Shauna; Milanese, Jean-Sébastien; Masoudi-Nejad, Ali; O'Connor-McCourt, Maureen

2015-02-01

Tumor genome sequencing leads to documenting thousands of DNA mutations and other genomic alterations. At present, these data cannot be analyzed adequately to aid in the understanding of tumorigenesis and its evolution. Moreover, we have little insight into how to use these data to predict clinical phenotypes and tumor progression to better design patient treatment. To meet these challenges, we discuss a cancer hallmark network framework for modeling genome sequencing data to predict cancer clonal evolution and associated clinical phenotypes. The framework includes: (1) cancer hallmarks that can be represented by a few molecular/signaling networks. 'Network operational signatures' which represent gene regulatory logics/strengths enable to quantify state transitions and measures of hallmark traits. Thus, sets of genomic alterations which are associated with network operational signatures could be linked to the state/measure of hallmark traits. The network operational signature transforms genotypic data (i.e., genomic alterations) to regulatory phenotypic profiles (i.e., regulatory logics/strengths), to cellular phenotypic profiles (i.e., hallmark traits) which lead to clinical phenotypic profiles (i.e., a collection of hallmark traits). Furthermore, the framework considers regulatory logics of the hallmark networks under tumor evolutionary dynamics and therefore also includes: (2) a self-promoting positive feedback loop that is dominated by a genomic instability network and a cell survival/proliferation network is the main driver of tumor clonal evolution. Surrounding tumor stroma and its host immune systems shape the evolutionary paths; (3) cell motility initiating metastasis is a byproduct of the above self-promoting loop activity during tumorigenesis; (4) an emerging hallmark network which triggers genome duplication dominates a feed-forward loop which in turn could act as a rate-limiting step for tumor formation; (5) mutations and other genomic alterations have specific patterns and tissue-specificity, which are driven by aging and other cancer-inducing agents. This framework represents the logics of complex cancer biology as a myriad of phenotypic complexities governed by a limited set of underlying organizing principles. It therefore adds to our understanding of tumor evolution and tumorigenesis, and moreover, potential usefulness of predicting tumors' evolutionary paths and clinical phenotypes. Strategies of using this framework in conjunction with genome sequencing data in an attempt to predict personalized drug targets, drug resistance, and metastasis for cancer patients, as well as cancer risks for healthy individuals are discussed. Accurate prediction of cancer clonal evolution and clinical phenotypes will have substantial impact on timely diagnosis, personalized treatment and personalized prevention of cancer. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

FXR and liver carcinogenesis

PubMed Central

Huang, Xiong-fei; Zhao, Wei-yu; Huang, Wen-dong

2015-01-01

Farnesoid X receptor (FXR) is a member of the nuclear receptor family and a ligand-modulated transcription factor. In the liver, FXR has been considered a multi-functional cell protector and a tumor suppressor. FXR can suppress liver carcinogenesis via different mechanisms: 1) FXR maintains the normal liver metabolism of bile acids, glucose and lipids; 2) FXR promotes liver regeneration and repair after injury; 3) FXR protects liver cells from death and enhances cell survival; 4) FXR suppresses hepatic inflammation, thereby preventing inflammatory damage; and 5) FXR can directly increase the expression of some tumor-suppressor genes and repress the transcription of several oncogenes. However, inflammation and epigenetic silencing are known to decrease FXR expression during tumorigenesis. The reactivation of FXR function in the liver may be a potential therapeutic approach for patients with liver cancer. PMID:25500874

Tricyclic Benzo[cd]azulenes Selectively Inhibit Activities of Pim Kinases and Restrict Growth of Epstein-Barr Virus-Transformed Cells

PubMed Central

Santio, Niina M.; Arnaudova, Ralica; Eerola, Sini K.; Rainio, Eeva-Marja; Aumüller, Ingo B.; Yli-Kauhaluoma, Jari; Koskinen, Päivi J.

2013-01-01

Oncogenic Pim family kinases are often overexpressed in human hematopoietic malignancies as well as in solid tumours. These kinases contribute to tumorigenesis by promoting cell survival and by enhancing resistance against chemotherapy and radiation therapy. Furthermore, we have recently shown that they increase the metastatic potential of adherent cancer cells. Here we describe identification of tricyclic benzo[cd]azulenes and their derivatives as effective and selective inhibitors of Pim kinases. These compounds inhibit Pim autophosphorylation and abrogate the anti-apoptotic effects of Pim kinases. They also reduce cancer cell motility and suppress proliferation of lymphoblastoid cell lines infected and immortalized by the Epstein-Barr virus. Thus, these novel Pim-selective inhibitors provide promising compounds for both research and therapeutic purposes. PMID:23405147

Human natural killer cells prevent infectious mononucleosis features by targeting lytic Epstein-Barr virus infection

PubMed Central

Chijioke, Obinna; Müller, Anne; Feederle, Regina; Barros, Mario Henrique M.; Krieg, Carsten; Emmel, Vanessa; Marcenaro, Emanuela; Leung, Carol S.; Antsiferova, Olga; Landtwing, Vanessa; Bossart, Walter; Moretta, Alessandro; Hassan, Rocio; Boyman, Onur; Niedobitek, Gerald; Delecluse, Henri-Jacques; Capaul, Riccarda; Münz, Christian

2014-01-01

SUMMARY Primary infection with the human oncogenic Epstein Barr virus (EBV) can result in infectious mononucleosis (IM), a self-limiting disease caused by massive lymphocyte expansion, which predisposes for the development of distinct EBV-associated lymphomas. It remains unclear why some individuals experience this symptomatic primary EBV infection, while the majority acquires the virus asymptomatically. Using a mouse model with reconstituted human immune system components, we show here that depletion of human natural killer (NK) cells enhances IM symptoms and promotes EBV-associated tumorigenesis, mainly due to loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies. PMID:24360958

Copper is required for oncogenic BRAF signalling and tumorigenesis.

PubMed

Brady, Donita C; Crowe, Matthew S; Turski, Michelle L; Hobbs, G Aaron; Yao, Xiaojie; Chaikuad, Apirat; Knapp, Stefan; Xiao, Kunhong; Campbell, Sharon L; Thiele, Dennis J; Counter, Christopher M

2014-05-22

The BRAF kinase is mutated, typically Val 600→Glu (V600E), to induce an active oncogenic state in a large fraction of melanomas, thyroid cancers, hairy cell leukaemias and, to a smaller extent, a wide spectrum of other cancers. BRAF(V600E) phosphorylates and activates the MEK1 and MEK2 kinases, which in turn phosphorylate and activate the ERK1 and ERK2 kinases, stimulating the mitogen-activated protein kinase (MAPK) pathway to promote cancer. Targeting MEK1/2 is proving to be an important therapeutic strategy, given that a MEK1/2 inhibitor provides a survival advantage in metastatic melanoma, an effect that is increased when administered together with a BRAF(V600E) inhibitor. We previously found that copper (Cu) influx enhances MEK1 phosphorylation of ERK1/2 through a Cu-MEK1 interaction. Here we show decreasing the levels of CTR1 (Cu transporter 1), or mutations in MEK1 that disrupt Cu binding, decreased BRAF(V600E)-driven signalling and tumorigenesis in mice and human cell settings. Conversely, a MEK1-MEK5 chimaera that phosphorylated ERK1/2 independently of Cu or an active ERK2 restored the tumour growth of murine cells lacking Ctr1. Cu chelators used in the treatment of Wilson disease decreased tumour growth of human or murine cells transformed by BRAF(V600E) or engineered to be resistant to BRAF inhibition. Taken together, these results suggest that Cu-chelation therapy could be repurposed to treat cancers containing the BRAF(V600E) mutation.

The shed ectodomain of Nr-CAM stimulates cell proliferation and motility, and confers cell transformation.

PubMed

Conacci-Sorrell, Maralice; Kaplan, Anna; Raveh, Shani; Gavert, Nancy; Sakurai, Takeshi; Ben-Ze'ev, Avri

2005-12-15

Nr-CAM, a cell-cell adhesion molecule of the immunoglobulin-like cell adhesion molecule family, known for its function in neuronal outgrowth and guidance, was recently identified as a target gene of beta-catenin signaling in human melanoma and colon carcinoma cells and tissue. Retrovirally mediated transduction of Nr-CAM into fibroblasts induces cell motility and tumorigenesis. We investigated the mechanisms by which Nr-CAM can confer properties related to tumor cell behavior and found that Nr-CAM expression in NIH3T3 cells protects cells from apoptosis in the absence of serum by constitutively activating the extracellular signal-regulated kinase and AKT signaling pathways. We detected a metalloprotease-mediated shedding of Nr-CAM into the culture medium of cells transfected with Nr-CAM, and of endogenous Nr-CAM in B16 melanoma cells. Conditioned medium and purified Nr-CAM-Fc fusion protein both enhanced cell motility, proliferation, and extracellular signal-regulated kinase and AKT activation. Moreover, Nr-CAM was found in complex with alpha4beta1 integrins in melanoma cells, indicating that it can mediate, in addition to homophilic cell-cell adhesion, heterophilic adhesion with extracellular matrix receptors. Suppression of Nr-CAM levels by small interfering RNA in B16 melanoma inhibited the adhesive and tumorigenic capacities of these cells. Stable expression of the Nr-CAM ectodomain in NIH3T3 cells conferred cell transformation and tumorigenesis in mice, suggesting that the metalloprotease-mediated shedding of Nr-CAM is a principal route for promoting oncogenesis by Nr-CAM.

Fetal alcohol exposure and mammary tumorigenesis in offspring: role of the estrogen and insulin-like growth factor systems.

PubMed

Cohick, Wendie S; Crismale-Gann, Catina; Stires, Hillary; Katz, Tiffany A

2015-01-01

Fetal alcohol spectrum disorders affect a significant number of live births each year, indicating that alcohol consumption during pregnancy is an important public health issue. Environmental exposures and lifestyle choices during pregnancy may affect the offspring's risk of disease in adulthood, leading to the idea that a woman's risk of breast cancer may be pre-programmed prior to birth. Exposure of pregnant rats to alcohol increases tumorigenesis in the adult offspring in response to mammary carcinogens. The estrogen and insulin-like growth factor (IGF-I) axes occupy central roles in normal mammary gland development and breast cancer. 17-β estradiol (E2) and IGF-I synergize to regulate formation of terminal end buds and ductal elongation during pubertal development. The intracellular signaling pathways mediated by the estrogen and IGF-I receptors cross-talk at multiple levels through both genomic and non-genomic mechanisms. Several components of the E2 and IGF-I systems are altered in early development in rat offspring exposed to alcohol in utero, therefore, these changes may play a role in the enhanced susceptibility to mammary carcinogens observed in adulthood. Alcohol exposure in utero induces a number of epigenetic alterations in non-mammary tissues in the offspring and other adverse in utero exposures induce epigenetic modifications in the mammary gland. Future studies will determine if fetal alcohol exposure can induce epigenetic modifications in genes that regulate E2/IGF action at key phases of mammary development, ultimately leading to changes in susceptibility to carcinogens.

Myristoylation of Src kinase mediates Src-induced and high-fat diet-accelerated prostate tumor progression in mice.

PubMed

Kim, Sungjin; Yang, Xiangkun; Li, Qianjin; Wu, Meng; Costyn, Leah; Beharry, Zanna; Bartlett, Michael G; Cai, Houjian

2017-11-10

Exogenous fatty acids provide substrates for energy production and biogenesis of the cytoplasmic membrane, but they also enhance cellular signaling during cancer cell proliferation. However, it remains controversial whether dietary fatty acids are correlated with tumor progression. In this study, we demonstrate that increased Src kinase activity is associated with high-fat diet-accelerated progression of prostate tumors and that Src kinases mediate this pathological process. Moreover, in the in vivo prostate regeneration assay, host SCID mice carrying Src(Y529F)-transduced regeneration tissues were fed a low-fat diet or a high-fat diet and treated with vehicle or dasatinib. The high-fat diet not only accelerated Src-induced prostate tumorigenesis in mice but also compromised the inhibitory effect of the anticancer drug dasatinib on Src kinase oncogenic potential in vivo We further show that myristoylation of Src kinase is essential to facilitate Src-induced and high-fat diet-accelerated tumor progression. Mechanistically, metabolism of exogenous myristic acid increased the biosynthesis of myristoyl CoA and myristoylated Src and promoted Src kinase-mediated oncogenic signaling in human cells. Of the fatty acids tested, only exogenous myristic acid contributed to increased intracellular myristoyl CoA levels. Our results suggest that targeting Src kinase myristoylation, which is required for Src kinase association at the cellular membrane, blocks dietary fat-accelerated tumorigenesis in vivo Our findings uncover the molecular basis of how the metabolism of myristic acid stimulates high-fat diet-mediated prostate tumor progression. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Boswellia serrata resin extract alleviates azoxymethane (AOM)/dextran sodium sulfate (DSS)-induced colon tumorigenesis.

PubMed

Chou, Ya-Chun; Suh, Joon Hyuk; Wang, Yu; Pahwa, Manoj; Badmaev, Vladimir; Ho, Chi-Tang; Pan, Min-Hsiung

2017-09-01

Boswellia serrata (BS) resin is a popular dietary supplement for joint nourishment. In this study, we investigated the chemopreventive effects of dietary BS extract and its impact of gut microbiota on azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated colon cancer in mice. Male ICR mice were injected with AOM and 2% DSS via drinking water. The mice were fed with 0.25 or 0.5% BS extract, and colonic tissue were collected at 15 weeks. The main effective components of BS supercritical CO 2 extraction were analyzed by LC-MS/MS are boswellic acids. We found that treatment with BS extract significantly reduce the colonic tumor formation. Western blot and histological analysis revealed that dietary BS extract could markedly reduce the inflammation associated protein levels expression. Furthermore, BS extract reduced cell proliferation via inhibiting phosphorylation level of protein kinase B (Akt), glycogen synthase kinase 3β (GSK3β), and downregulation of cyclin D1. In addition, BS extract also altered the composition of gut microbiota by enhancing the proportion of Clostridiales and reducing the percentage of Bacteroidales. In summary, BS extract decreased the protein levels of inflammative enzymes such as inducible nitric oxide synthase and cyclooxygenase-2 in colonic mucosa. It also mediated Akt/GSK3β/cyclin D1 signaling pathway and altered the composition of gut microbiota to alleviate tumor growth. Taken together, this study suggests that BS extract has great potential to suppress colon tumorigenesis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metformin: Multi-faceted protection against cancer

PubMed Central

Cufí, Sílvia; Oliveras-Ferraros, Cristina; Bosch-Barrera, Joaquim; Joven, Jorge; Martin-Castillo, Begoña; Menendez, Javier A.

2011-01-01

The biguanide metformin, a widely used drug for the treatment of type 2 diabetes, may exert cancer chemopreventive effects by suppressing the transformative and hyperproliferative processes that initiate carcinogenesis. Metformin's molecular targets in cancer cells (e.g., mTOR, HER2) are similar to those currently being used for directed cancer therapy. However, metformin is nontoxic and might be extremely useful for enhancing treatment efficacy of mechanism-based and biologically targeted drugs. Here, we first revisit the epidemiological, preclinical, and clinical evidence from the last 5 years showing that metformin is a promising candidate for oncology therapeutics. Second, the anticancer effects of metformin by both direct (insulin-independent) and indirect (insulin-dependent) mechanisms are discussed in terms of metformin-targeted processes and the ontogenesis of cancer stem cells (CSC), including Epithelial-to-Mesenchymal Transition (EMT) and microRNAs-regulated dedifferentiation of CSCs. Finally, we present preliminary evidence that metformin may regulate cellular senescence, an innate safeguard against cellular immortalization. There are two main lines of evidence that suggest that metformin's primary target is the immortalizing step during tumorigenesis. First, metformin activates intracellular DNA damage response checkpoints. Second, metformin attenuates the anti-senescence effects of the ATP-generating glycolytic metabotype-the Warburg effect-, which is required for self-renewal and proliferation of CSCs. If metformin therapy presents an intrinsic barrier against tumorigenesis by lowering the threshold for stress-induced senescence, metformin therapeutic strategies may be pivotal for therapeutic intervention for cancer. Current and future clinical trials will elucidate whether metformin has the potential to be used in preventive and treatment settings as an adjuvant to current cancer therapeutics. PMID:22203527

Identification of a GTP-bound Rho specific scFv molecular sensor by phage display selection

PubMed Central

Goffinet, Marine; Chinestra, Patrick; Lajoie-Mazenc, Isabelle; Medale-Giamarchi, Claire; Favre, Gilles; Faye, Jean-Charles

2008-01-01

Background The Rho GTPases A, B and C proteins, members of the Rho family whose activity is regulated by GDP/GTP cycling, function in many cellular pathways controlling proliferation and have recently been implicated in tumorigenesis. Although overexpression of Rho GTPases has been correlated with tumorigenesis, only their GTP-bound forms are able to activate the signalling pathways implicated in tumorigenesis. Thus, the focus of much recent research has been to identify biological tools capable of quantifying the level of cellular GTP-bound Rho, or determining the subcellular location of activation. However useful, these tools used to study the mechanism of Rho activation still have limitations. The aim of the present work was to employ phage display to identify a conformationally-specific single chain fragment variable (scFv) that recognizes the active, GTP-bound, form of Rho GTPases and is able to discriminate it from the inactive, GDP-bound, Rho in endogenous settings. Results After five rounds of phage selection using a constitutively activated mutant of RhoB (RhoBQ63L), three scFvs (A8, C1 and D11) were selected for subsequent analysis. Further biochemical characterization was pursued for the single clone, C1, exhibiting an scFv structure. C1 was selective for the GTP-bound form of RhoA, RhoB, as well as RhoC, and failed to recognize GTP-loaded Rac1 or Cdc42, two other members of the Rho family. To enhance its production, soluble C1 was expressed in fusion with the N-terminal domain of phage protein pIII (scFv C1-N1N2), it appeared specifically associated with GTP-loaded recombinant RhoA and RhoB via immunoprecipitation, and endogenous activated Rho in HeLa cells as determined by immunofluorescence. Conclusion We identified an antibody, C1-N1N2, specific for the GTP-bound form of RhoB from a phage library, and confirmed its specificity towards GTP-bound RhoA and RhoC, as well as RhoB. The success of C1-N1N2 in discriminating activated Rho in immunofluorescence studies implies that this new tool, in collaboration with currently used RhoA and B antibodies, has the potential to analyze Rho activation in cell function and tumor development. PMID:18377644

Aging is associated with an expansion of CD49fhi mammary stem cells that show a decline in function and increased transformation potential

PubMed Central

Dong, Qiaoxiang; Gao, Hui; Shi, Yuanshuo; Zhang, Fuchuang; Gu, Xiang; Wu, Anqi; Wang, Danhan; Chen, Yuanhong; Bandyopadhyay, Abhik; Yeh, I-Tien; Daniel, Benjamin J.; Chen, Yidong; Zou, Yi; Rebel, Vivienne L.; Walter, Christi A.; Lu, Jianxin; Huang, Changjiang; Sun, Lu-Zhe

2016-01-01

Breast cancer incidence increases during aging, yet the mechanism of age-associated mammary tumorigenesis is unclear. Mammary stem cells are believed to play an important role in breast tumorigenesis, but how their function changes with age is unknown. We compared mammary epithelial cells isolated from young and old mammary glands of different cohorts of C57BL6/J and BALB/c mice, and our findings revealed that old mammary glands were characterized by increased basal cell pool comprised of mostly CD49fhi cells, altered luminal-to-basal cell ratio, and irregular ductal morphology. More interestingly, basal stem cells in old mice were increased in frequency, but showed a functional decline of differentiation and increased neoplastic transformation potential. Gene signature enrichment analysis revealed a significant enrichment of a luminal cell gene expression signature in the basal stem cell-enriched population from old mice, suggesting some luminal cells were expressing basal markers. Immunofluorescence staining confirmed the presence of luminal cells with high CD49f expression in hyperplastic lesions implicating these cells as undergoing luminal to basal phenotypic changes during aging. Whole transcriptome analysis showed elevated immune and inflammatory responses in old basal stem cells and stromal cells, which may be the underlying cause for increased CD49fhi basal-like cells in aged glands. PMID:27852980

Global Profiling and Molecular Characterization of Alternative Splicing Events Misregulated in Lung Cancer ▿ †

PubMed Central

Misquitta-Ali, Christine M.; Cheng, Edith; O'Hanlon, Dave; Liu, Ni; McGlade, C. Jane; Tsao, Ming Sound; Blencowe, Benjamin J.

2011-01-01

Alternative splicing (AS) is a widespread mechanism underlying the generation of proteomic and regulatory complexity. However, which of the myriad of human AS events play important roles in disease is largely unknown. To identify frequently occurring AS events in lung cancer, we used AS microarray profiling and reverse transcription-PCR (RT-PCR) assays to survey patient-matched normal and adenocarcinoma tumor tissues from the lungs of 29 individuals diagnosed with non-small cell lung cancer (NSCLC). Of 5,183 profiled alternative exons, four displayed tumor-associated changes in the majority of the patients. These events affected transcripts from the VEGFA, MACF1, APP, and NUMB genes. Similar AS changes were detected in NUMB and APP transcripts in primary breast and colon tumors. Tumor-associated increases in NUMB exon 9 inclusion correlated with reduced levels of NUMB protein expression and activation of the Notch signaling pathway, an event that has been linked to tumorigenesis. Moreover, short hairpin RNA (shRNA) knockdown of NUMB followed by isoform-specific rescue revealed that expression of the exon 9-skipped (nontumor) isoform represses Notch target gene activation whereas expression of the exon 9-included (tumor) isoform lacks this activity and is capable of promoting cell proliferation. The results thus reveal widespread AS changes in NSCLC that impact cell signaling in a manner that likely contributes to tumorigenesis. PMID:21041478

Aging is associated with an expansion of CD49fhi mammary stem cells that show a decline in function and increased transformation potential.

PubMed

Dong, Qiaoxiang; Gao, Hui; Shi, Yuanshuo; Zhang, Fuchuang; Gu, Xiang; Wu, Anqi; Wang, Danhan; Chen, Yuanhong; Bandyopadhyay, Abhik; Yeh, I-Tien; Daniel, Benjamin J; Chen, Yidong; Zou, Yi; Rebel, Vivienne L; Walter, Christi A; Lu, Jianxin; Huang, Changjiang; Sun, Lu-Zhe

2016-11-15

Breast cancer incidence increases during aging, yet the mechanism of age-associated mammary tumorigenesis is unclear. Mammary stem cells are believed to play an important role in breast tumorigenesis, but how their function changes with age is unknown. We compared mammary epithelial cells isolated from young and old mammary glands of different cohorts of C57BL6/J and BALB/c mice, and our findings revealed that old mammary glands were characterized by increased basal cell pool comprised of mostly CD49f hi cells, altered luminal-to-basal cell ratio, and irregular ductal morphology. More interestingly, basal stem cells in old mice were increased in frequency, but showed a functional decline of differentiation and increased neoplastic transformation potential. Gene signature enrichment analysis revealed a significant enrichment of a luminal cell gene expression signature in the basal stem cell-enriched population from old mice, suggesting some luminal cells were expressing basal markers. Immunofluorescence staining confirmed the presence of luminal cells with high CD49f expression in hyperplastic lesions implicating these cells as undergoing luminal to basal phenotypic changes during aging. Whole transcriptome analysis showed elevated immune and inflammatory responses in old basal stem cells and stromal cells, which may be the underlying cause for increased CD49f hi basal-like cells in aged glands.

PARP-1 serves as a novel molecular marker for hepatocellular carcinoma in a Southern Chinese Zhuang population.

PubMed

Li, Jiatong; Dou, Dongwei; Li, Ping; Luo, Wenqi; Lv, Wenxin; Zhang, Chengdong; Song, Xiaowei; Yang, Yuan; Zhang, Yuening; Xu, Yanzhen; Xiao, Feifan; Wei, Yan; Qin, Jian; Li, Hongtao; Yang, Xiaoli

2017-07-01

PARP-1 (poly(ADP-ribose) polymerase-1) plays an important role in tumorigenesis. Since its effects on different populations are varied, this study investigated the impact of PARP-1 on primary hepatocellular carcinoma in a Southern Chinese Zhuang population. We assessed the global PARP-1 messenger RNA expression in patients with hepatocellular carcinoma using The Cancer Genome Atlas dataset. Increased PARP-1 expression, related to alpha-fetoprotein level, was observed. The area under the receiver operating characteristic curve value was 0.833. Kaplan-Meier survival curves indicated that higher PARP-1 expression was not correlated with poorer overall survival and recurrence-free survival. In a Zhuang population, PARP-1 messenger RNA and protein levels were increased in the hepatocellular carcinoma tissue and its adjacent liver tissues as assessed by quantitative polymerase chain reaction, immunohistochemistry, and western blotting. Higher PARP-1 level was associated with a higher tumor stage (p < 0.05), without correlation with age, gender, smoking, drinking, tumor size, serum alpha-fetoprotein level, hepatitis B virus infection, metastasis, and invasion (p > 0.05). Further analysis suggested that H2AX, a PARP-1 protein interaction partner, was coordinated with PARP-1 in hepatocellular carcinoma tumorigenesis. Overall, some new characteristics of PARP-1 expression were noted in the Zhuang population. PARP-1 is a novel promising diagnostic marker for hepatocellular carcinoma in the Southern Chinese Zhuang population.

Global profiling and molecular characterization of alternative splicing events misregulated in lung cancer.

PubMed

Misquitta-Ali, Christine M; Cheng, Edith; O'Hanlon, Dave; Liu, Ni; McGlade, C Jane; Tsao, Ming Sound; Blencowe, Benjamin J

2011-01-01

Alternative splicing (AS) is a widespread mechanism underlying the generation of proteomic and regulatory complexity. However, which of the myriad of human AS events play important roles in disease is largely unknown. To identify frequently occurring AS events in lung cancer, we used AS microarray profiling and reverse transcription-PCR (RT-PCR) assays to survey patient-matched normal and adenocarcinoma tumor tissues from the lungs of 29 individuals diagnosed with non-small cell lung cancer (NSCLC). Of 5,183 profiled alternative exons, four displayed tumor-associated changes in the majority of the patients. These events affected transcripts from the VEGFA, MACF1, APP, and NUMB genes. Similar AS changes were detected in NUMB and APP transcripts in primary breast and colon tumors. Tumor-associated increases in NUMB exon 9 inclusion correlated with reduced levels of NUMB protein expression and activation of the Notch signaling pathway, an event that has been linked to tumorigenesis. Moreover, short hairpin RNA (shRNA) knockdown of NUMB followed by isoform-specific rescue revealed that expression of the exon 9-skipped (nontumor) isoform represses Notch target gene activation whereas expression of the exon 9-included (tumor) isoform lacks this activity and is capable of promoting cell proliferation. The results thus reveal widespread AS changes in NSCLC that impact cell signaling in a manner that likely contributes to tumorigenesis.

Expression of microRNA-133 inhibits epithelial-mesenchymal transition in lung cancer cells by directly targeting FOXQ1.

PubMed

Xiao, Bo; Liu, Huazhen; Gu, Zeyun; Ji, Cheng

2016-10-01

MicroRNA (miR) was implicated in the tumorigenesis of many types of cancer, but no study was conducted on the exact role of miR-133 in lung cancer. We have identified miR-133 as a putative regulator of FOXQ1 expression, and investigated the potential involvement of miR-133 in the migration and invasion of lung cancer cells, as well as the underlying molecular mechanism. MiR-133 directly targeted and down-regulated FOXQ1 expression, which in turn reduced TGF-β level. MiR-133 was down-regulated in lung cancer cell lines A549 and HCC827, and its re-expression significantly inhibited the migration and invasion of the lung cancer cells. Further investigation revealed that this inhibition was caused by reversing the epithelial-mesenchymal transition, evidenced by miR-133 induced elevation of epithelial marker E-cadherin, and reduction of mesenchymal marker Vimentin. Our study is the first to identify miR-133 as a biomarker for lung cancer. It functions to down-regulate FOXQ1, and inhibit epithelial-mesenchymal transition, which antagonizes lung cancer tumorigenesis. Therefore our data support the role of miR-133 as a potential molecular therapeutic tool in treating lung cancer. Copyright © 2015 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

HMGB1 promotes ductular reaction and tumorigenesis in autophagy-deficient livers.

PubMed

Khambu, Bilon; Huda, Nazmul; Chen, Xiaoyun; Antoine, Daniel J; Li, Yong; Dai, Guoli; Köhler, Ulrike A; Zong, Wei-Xing; Waguri, Satoshi; Werner, Sabine; Oury, Tim D; Dong, Zheng; Yin, Xiao-Ming

2018-06-01

Autophagy is important for liver homeostasis, and the deficiency leads to injury, inflammation, ductular reaction (DR), fibrosis, and tumorigenesis. It is not clear how these events are mechanistically linked to autophagy deficiency. Here, we reveal the role of high-mobility group box 1 (HMGB1) in two of these processes. First, HMGB1 was required for DR, which represents the expansion of hepatic progenitor cells (HPCs) implicated in liver repair and regeneration. DR caused by hepatotoxic diets (3,5-diethoxycarbonyl-1,4-dihydrocollidine [DDC] or choline-deficient, ethionine-supplemented [CDE]) also depended on HMGB1, indicating that HMGB1 may be generally required for DR in various injury scenarios. Second, HMGB1 promoted tumor progression in autophagy-deficient livers. Receptor for advanced glycation end product (RAGE), a receptor for HMGB1, was required in the same two processes and could mediate the proliferative effects of HMBG1 in isolated HPCs. HMGB1 was released from autophagy-deficient hepatocytes independently of cellular injury but depended on NRF2 and the inflammasome, which was activated by NRF2. Pharmacological or genetic activation of NRF2 alone, without disabling autophagy or causing injury, was sufficient to cause inflammasome-dependent HMGB1 release. In conclusion, HMGB1 release is a critical mechanism in hepatic pathogenesis under autophagy-deficient conditions and leads to HPC expansion as well as tumor progression.

Comparative analysis of primary hepatocellular carcinoma with single and multiple lesions by iTRAQ-based quantitative proteomics.

PubMed

Xing, Xiaohua; Huang, Yao; Wang, Sen; Chi, Minhui; Zeng, Yongyi; Chen, Lihong; Li, Ling; Zeng, Jinhua; Lin, Minjie; Han, Xiao; Liu, Xiaolong; Liu, Jingfeng

2015-10-14

In clinical practices, the therapeutic outcomes and prognosis of hepatocellular carcinoma (HCC) patients with different tumor numbers after surgery are very different; however, the underlying mechanisms of the tumorigenesis and development of HCC with different tumor numbers are still not well understood. Here, we systematically compared the overall proteome profiles between the primary HCC with single and multiple lesions using iTRAQ-based quantitative proteomics approach. We identified that 107 and 330 proteins were dysregulated in HCC tissue with multiple lesions (MC group) and HCC tissue with a single lesion (SC group), compared with their non-cancerous tissue (MN and SN groups) respectively. The dysregulated proteins in MC group are concentrated in UBC signaling pathway and NFκB signaling pathway, but the dysregulated proteins in SC group are more concentrated in ERK signaling pathway and the NFκB signaling pathway. These information revealed that there might be different molecular mechanisms of the tumorigenesis and development of the HCC with single and multiple lesions. Furthermore, HSD17B13 were only down-regulated in MC group while HK2 were only up-regulated in SC group among these dysregulated proteins. Therefore, the protein HSD17B13 and HK2 might be potential biomarkers for the primary HCC with single and multiple lesions. Copyright © 2015 Elsevier B.V. All rights reserved.

The ShcA SH2 domain engages a 14-3-3/PI3'K signaling complex and promotes breast cancer cell survival.

PubMed

Ursini-Siegel, J; Hardy, W R; Zheng, Y; Ling, C; Zuo, D; Zhang, C; Podmore, L; Pawson, T; Muller, W J

2012-11-29

The ShcA adapter protein transmits activating signals downstream of receptor and cytoplasmic tyrosine kinases through the establishment of phosphotyrosine-dependent complexes. In this regard, ShcA possesses both a phosphotyrosine-binding domain (PTB) and Src homology 2 domain (SH2), which bind phosphotyrosine residues in a sequence-specific manner. Although the majority of receptor tyrosine kinases expressed in breast cancer cells bind the PTB domain, very little is known regarding the biological importance of SH2-driven ShcA signaling during mammary tumorigenesis. To address this, we employed transgenic mice expressing a mutant ShcA allele harboring a non-functional SH2 domain (ShcR397K) under the transcriptional control of the endogenous ShcA promoter. Using transplantation approaches, we demonstrate that SH2-dependent ShcA signaling within the mammary epithelial compartment is essential for breast tumor outgrowth, survival and the development of lung metastases. We further show that the ShcA SH2 domain activates the AKT pathway, potentially through a novel SH2-mediated complex between ShcA, 14-3-3ζ and the p85 regulatory subunit of phosphatidylinositol 3 (PI3') kinase. This study is the first to demonstrate that the SH2 domain of ShcA is critical for tumor survival during mammary tumorigenesis.

Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice

PubMed Central

Sasada, Tatsunari; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Takakura, Yuji; Kawaguchi, Yasuo; Sotomaru, Yusuke; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

2015-01-01

The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc) knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma—caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc+/flox, abbreviated to CPC;Apc) or microsatellite (CDX2P9.5-G19Cre;Apcflox/flox and CDX2P9.5-G22Cre;Apcflox/flox) instability, respectively—were administered chlorinated (10.0 mg/L chlorine) or tap (0.7 mg/L chlorine) water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apcflox/flox and CDX2P9.5-G22Cre;Apcflox/flox mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to differences in gastrointestinal commensal populations. PMID:26186212

Chlorinated Water Modulates the Development of Colorectal Tumors with Chromosomal Instability and Gut Microbiota in Apc-Deficient Mice.

PubMed

Sasada, Tatsunari; Hinoi, Takao; Saito, Yasufumi; Adachi, Tomohiro; Takakura, Yuji; Kawaguchi, Yasuo; Sotomaru, Yusuke; Sentani, Kazuhiro; Oue, Naohide; Yasui, Wataru; Ohdan, Hideki

2015-01-01

The gastrointestinal tract is continuously exposed to a variety of chemicals and commensal bacteria. Recent studies have shown that changes in gut microbial populations caused by chlorine or other chemicals in the drinking water influence the development of human colorectal cancer, although the mechanism of tumorigenesis in the gut epithelium is obfuscated by the diversity of microflora and complexity of the tumor microenvironment. In this regard, mouse models that recapitulate human colorectal cancer are an invaluable tool. In this study, we used two conditional adenomatous polyposis coli (Apc) knockout mouse models to investigate the effect of chlorinated water on tumorigenesis in the digestive tract. Mice with colon-specific carcinoma--caused by either chromosomal (CDX2P 9.5-NLS Cre;Apc(+/flox), abbreviated to CPC;Apc) or microsatellite (CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox)) instability, respectively--were administered chlorinated (10.0 mg/L chlorine) or tap (0.7 mg/L chlorine) water and evaluated for colon polyp formation. In CPC;Apc mice given chlorinated drinking water, tumors tended to develop in the colon, whereas in those that drank tap water, tumors were mostly observed in the small intestine. There was no difference in the rate of tumor formation of CDX2P9.5-G19Cre;Apc(flox/flox) and CDX2P9.5-G22Cre;Apc(flox/flox) mice consuming chlorinated as compared to tap water, suggesting that microsatellite instability in the Apc gene does not significantly affect tumorigenesis. Chlorinated water altered the enteric environment by reducing the fecal populations of the obligatory anaerobes Clostridium perfringens and C. difficile, as well as species belonging to the Atopobium cluster, including Enterobacteriaceae and Staphylococcus sp., which was associated with colon tumorigenesis in CPC;Apc mice. These results suggest that differences in tumorigenesis among CPC;Apc mice consuming chlorinated versus tap water may be due to differences in gastrointestinal commensal populations.

The Role of Chronic Inflammation in Obesity-Associated Cancers

PubMed Central

2013-01-01

There is a strong relationship between metabolism and immunity, which can become deleterious under conditions of metabolic stress. Obesity, considered a chronic inflammatory disease, is one example of this link. Chronic inflammation is increasingly being recognized as an etiology in several cancers, particularly those of epithelial origin, and therefore a potential link between obesity and cancer. In this review, the connection between the different factors that can lead to the chronic inflammatory state in the obese individual, as well as their effect in tumorigenesis, is addressed. Furthermore, the association between obesity, inflammation, and esophageal, liver, colon, postmenopausal breast, and endometrial cancers is discussed. PMID:23819063

Key Issues in the Modes of Action and Effects of Trichloroethylene Metabolites for Liver and Kidney Tumorigenesis

PubMed Central

Caldwell, Jane C.; Keshava, Nagalakshmi

2006-01-01

Trichloroethylene (TCE) exposure has been associated with increased risk of liver and kidney cancer in both laboratory animal and epidemiologic studies. The U.S. Environmental Protection Agency 2001 draft TCE risk assessment concluded that it is difficult to determine which TCE metabolites may be responsible for these effects, the key events involved in their modes of action (MOAs), and the relevance of these MOAs to humans. In this article, which is part of a mini-monograph on key issues in the health risk assessment of TCE, we present a review of recently published scientific literature examining the effects of TCE metabolites in the context of the preceding questions. Studies of the TCE metabolites dichloroacetic acid (DCA), trichloroacetic acid (TCA), and chloral hydrate suggest that both DCA and TCA are involved in TCE-induced liver tumorigenesis and that many DCA effects are consistent with conditions that increase the risk of liver cancer in humans. Studies of S-(1,2-dichlorovinyl)-l-cysteine have revealed a number of different possible cell signaling effects that may be related to kidney tumorigenesis at lower concentrations than those leading to cytotoxicity. Recent studies of trichloroethanol exploring an alternative hypothesis for kidney tumorigenesis have failed to establish the formation of formate as a key event for TCE-induced kidney tumors. Overall, although MOAs and key events for TCE-induced liver and kidney tumors have yet to be definitively established, these results support the likelihood that toxicity is due to multiple metabolites through several MOAs, none of which appear to be irrelevant to humans. PMID:16966105

Circuits of cancer drivers revealed by convergent misregulation of transcription factor targets across tumor types.

PubMed

Gonzalez-Perez, Abel

2016-01-20

Large tumor genome sequencing projects have now uncovered a few hundred genes involved in the onset of tumorigenesis, or drivers, in some two dozen malignancies. One of the main challenges emerging from this catalog of drivers is how to make sense of their heterogeneity in most cancer types. This is key not only to understand how carcinogenesis appears and develops in these malignancies to be able to early diagnose them, but also to open up the possibility to employ therapeutic strategies targeting a driver protein to counteract the alteration of another connected driver. Here, I focus on driver transcription factors and their connection to tumorigensis in several tumor types through the alteration of the expression of their targets. First, I explore their involvement in tumorigenesis as mutational drivers in 28 different tumor types. Then, I collect a list of downstream targets of the all driver transcription factors (TFs), and identify which of them exhibit a differential expression upon alterations of driver transcription factors. I identify the subset of targets of each TF most likely mediating the tumorigenic effect of their driver alterations in each tumor type, and explore their overlap. Furthermore, I am able to identify other driver genes that cause tumorigenesis through the alteration of very similar sets of targets. I thus uncover these circuits of connected drivers which cause tumorigenesis through the perturbation of overlapping cellular pathways in a pan-cancer manner across 15 malignancies. The systematic detection of these circuits may be key to propose novel therapeutic strategies indirectly targeting driver alterations in tumors.

Mutant p53-R273H mediates cancer cell survival and anoikis resistance through AKT-dependent suppression of BCL2-modifying factor (BMF).

PubMed

Tan, B S; Tiong, K H; Choo, H L; Chung, F Fei-Lei; Hii, L-W; Tan, S H; Yap, I K S; Pani, S; Khor, N T W; Wong, S F; Rosli, R; Cheong, S-K; Leong, C-O

2015-07-16

p53 is the most frequently mutated tumor-suppressor gene in human cancers. Unlike other tumor-suppressor genes, p53 mutations mainly occur as missense mutations within the DNA-binding domain, leading to the expression of full-length mutant p53 protein. Mutant p53 proteins not only lose their tumor-suppressor function, but may also gain new oncogenic functions and promote tumorigenesis. Here, we showed that silencing of endogenous p53-R273H contact mutant, but not p53-R175H conformational mutant, reduced AKT phosphorylation, induced BCL2-modifying factor (BMF) expression, sensitized BIM dissociation from BCL-XL and induced mitochondria-dependent apoptosis in cancer cells. Importantly, cancer cells harboring endogenous p53-R273H mutant were also found to be inherently resistant to anoikis and lack BMF induction following culture in suspension. Underlying these activities is the ability of p53-R273H mutant to suppress BMF expression that is dependent on constitutively active PI3K/AKT signaling. Collectively, these findings suggest that p53-R273H can specifically drive AKT signaling and suppress BMF expression, resulting in enhanced cell survivability and anoikis resistance. These findings open the possibility that blocking of PI3K/AKT will have therapeutic benefit in mutant p53-R273H expressing cancers.

GRAMD1B regulates cell migration in breast cancer cells through JAK/STAT and Akt signaling.

PubMed

Khanna, Puja; Lee, Joan Shuying; Sereemaspun, Amornpun; Lee, Haeryun; Baeg, Gyeong Hun

2018-06-22

Dysregulated JAK/STAT signaling has been implicated in breast cancer metastasis, which is associated with high relapse risks. However, mechanisms underlying JAK/STAT signaling-mediated breast tumorigenesis are poorly understood. Here, we showed that GRAMD1B expression is upregulated on IL-6 but downregulated upon treatment with the JAK2 inhibitor AG490 in the breast cancer MDA-MB-231 cells. Notably, Gramd1b knockdown caused morphological changes of the cells, characterized by the formation of membrane ruffling and protrusions, implicating its role in cell migration. Consistently, GRAMD1B inhibition significantly enhanced cell migration, with an increase in the levels of the Rho family of GTPases. We also found that Gramd1b knockdown-mediated pro-migratory phenotype is associated with JAK2/STAT3 and Akt activation, and that JAK2 or Akt inhibition efficiently suppresses the phenotype. Interestingly, AG490 dose-dependently increased p-Akt levels, and our epistasis analysis suggested that the effect of JAK/STAT inhibition on p-Akt is via the regulation of GRAMD1B expression. Taken together, our results suggest that GRAMD1B is a key signaling molecule that functions to inhibit cell migration in breast cancer by negating both JAK/STAT and Akt signaling, providing the foundation for its development as a novel biomarker in breast cancer.

Regulation of the Nampt-mediated NAD salvage pathway and its therapeutic implications in pancreatic cancer.

PubMed

Ju, Huai-Qiang; Zhuang, Zhuo-Nan; Li, Hao; Tian, Tian; Lu, Yun-Xin; Fan, Xiao-Qiang; Zhou, Hai-Jun; Mo, Hai-Yu; Sheng, Hui; Chiao, Paul J; Xu, Rui-Hua

2016-08-28

Nicotinamide adenine dinucleotide (NAD) is a crucial cofactor for the redox reactions in the metabolic pathways of cancer cells that have elevated aerobic glycolysis (Warburg effect). Cancer cells are reported to rely on NAD recycling and inhibition of the NAD salvage pathway causes metabolic collapse and cell death. However, the underlying regulatory mechanisms and clinical implications for the NAD salvage pathway in pancreatic ductal adenocarcinoma (PDAC) remain unclear. This study showed that the expression of Nampt, the rate-limiting enzyme of the NAD salvage pathway, was significantly increased in PDAC cells and PDAC tissues. Additionally, inhibition of Nampt impaired tumor growth in vitro and tumorigenesis in vivo, which was accompanied by a decreased cellular NAD level and glycolytic activity. Mechanistically, the Nampt expression was independent of Kras and p16 status, but it was directly regulated by miR-206, which was inversely correlated with the expression of Nampt in PDAC tissues. Importantly, pharmacological inhibition of Nampt by its inhibitor, FK866, significantly enhanced the antitumor activity of gemcitabine in PDAC cells and in orthotopic xenograft mouse models. In conclusion, the present study revealed a novel regulatory mechanism for Nampt in PDAC and suggested that Nampt inhibition may override gemcitabine resistance by decreasing the NAD level and suppressing glycolytic activity, warranting further clinical investigation for pancreatic cancer treatment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The tumor microenvironment in esophageal cancer.

PubMed

Lin, E W; Karakasheva, T A; Hicks, P D; Bass, A J; Rustgi, A K

2016-10-13

Esophageal cancer is a deadly disease, ranking sixth among all cancers in mortality. Despite incremental advances in diagnostics and therapeutics, esophageal cancer still carries a poor prognosis, and thus, there remains a need to elucidate the molecular mechanisms underlying this disease. There is accumulating evidence that a comprehensive understanding of the molecular composition of esophageal cancer requires attention to not only tumor cells but also the tumor microenvironment (TME), which contains diverse cell populations, signaling factors and structural molecules that interact with tumor cells and support all stages of tumorigenesis. In esophageal cancer, environmental exposures can trigger chronic inflammation, which leads to constitutive activation of pro-inflammatory signaling pathways that promote survival and proliferation. Antitumor immunity is attenuated by cell populations such as myeloid-derived suppressor cells and regulatory T cells, as well as immune checkpoints like programmed death-1. Other immune cells such as tumor-associated macrophages can have other pro-tumorigenic functions, including the induction of angiogenesis and tumor cell invasion. Cancer-associated fibroblasts secrete growth factors and alter the extracellular matrix to create a tumor niche and enhance tumor cell migration and metastasis. Further study of how these TME components relate to the different stages of tumor progression in each esophageal cancer subtype will lead to development of novel and specific TME-targeting therapeutic strategies, which offer considerable potential especially in the setting of combination therapy.

Tie2 signaling cooperates with TNF to promote the pro-inflammatory activation of human macrophages independently of macrophage functional phenotype.

PubMed

García, Samuel; Krausz, Sarah; Ambarus, Carmen A; Fernández, Beatriz Malvar; Hartkamp, Linda M; van Es, Inge E; Hamann, Jörg; Baeten, Dominique L; Tak, Paul P; Reedquist, Kris A

2014-01-01

Angiopoietin (Ang) -1 and -2 and their receptor Tie2 play critical roles in regulating angiogenic processes during development, homeostasis, tumorigenesis, inflammation and tissue repair. Tie2 signaling is best characterized in endothelial cells, but a subset of human and murine circulating monocytes/macrophages essential to solid tumor formation express Tie2 and display immunosuppressive properties consistent with M2 macrophage polarization. However, we have recently shown that Tie2 is strongly activated in pro-inflammatory macrophages present in rheumatoid arthritis patient synovial tissue. Here we examined the relationship between Tie2 expression and function during human macrophage polarization. Tie2 expression was observed under all polarization conditions, but was highest in IFN-γ and IL-10 -differentiated macrophages. While TNF enhanced expression of a common restricted set of genes involved in angiogenesis and inflammation in GM-CSF, IFN-γ and IL-10 -differentiated macrophages, expression of multiple chemokines and cytokines, including CXCL3, CXCL5, CXCL8, IL6, and IL12B was further augmented in the presence of Ang-1 and Ang-2, via Tie2 activation of JAK/STAT signaling. Conditioned medium from macrophages stimulated with Ang-1 or Ang-2 in combination with TNF, sustained monocyte recruitment. Our findings suggest a general role for Tie2 in cooperatively promoting the inflammatory activation of macrophages, independently of polarization conditions.

The Tumor Microenvironment in Esophageal Cancer

PubMed Central

Lin, Eric W.; Karakasheva, Tatiana A.; Hicks, Philip D.; Bass, Adam J.; Rustgi, Anil K.

2016-01-01

Esophageal cancer is a deadly disease, ranking sixth among all cancers in mortality. Despite incremental advances in diagnostics and therapeutics, esophageal cancer still carries a poor prognosis, and thus there remains a need to elucidate the molecular mechanisms underlying this disease. There is accumulating evidence that a comprehensive understanding of the molecular composition of esophageal cancer requires attention to not only tumor cells but also the tumor microenvironment, which contains diverse cell populations, signaling factors, and structural molecules that interact with tumor cells and support all stages of tumorigenesis. In esophageal cancer, environmental exposures can trigger chronic inflammation, which leads to constitutive activation of pro-inflammatory signaling pathways that promote survival and proliferation. Anti-tumor immunity is attenuated by cell populations such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), as well as immune checkpoints like programmed death-1 (PD-1). Other immune cells such as tumor-associated macrophages can have other pro-tumorigenic functions, including the induction of angiogenesis and tumor cell invasion. Cancer-associated fibroblasts secrete growth factors and alter the extracellular matrix (ECM) to create a tumor niche and enhance tumor cell migration and metastasis. Further study of how these TME components relate to the different stages of tumor progression in each esophageal cancer subtype will lead to development of novel and specific TME-targeting therapeutic strategies, which offer considerable potential especially in the setting of combination therapy. PMID:26923327

EF24 inhibits tumor growth and metastasis via suppressing NF-kappaB dependent pathways in human cholangiocarcinoma

PubMed Central

Yin, Da-long; Liang, Ying-jian; Zheng, Tong-sen; Song, Rui-peng; Wang, Jia-bei; Sun, Bo-shi; Pan, Shang-ha; Qu, Lian-dong; Liu, Jia-ren; Jiang, Hong-chi; Liu, Lian-xin

2016-01-01

A synthetic monoketone analog of curcumin, termed 3, 5-bis (2-flurobenzylidene) piperidin-4-one (EF24), has been reported to inhibit the growth of a variety of cancer cells both in vitro and in vivo. However, whether EF24 has anticancer effects on cholangiocarcinoma (CCA) cells and the mechanisms remain to be investigated. The aim of our study was to evaluate the molecular mechanisms underlying the anticancer effects of EF24 on CCA tumor growth and metastasis. Cell proliferation, apoptosis, migration, invasion, tumorigenesis and metastasis were examined. EF24 exhibited time- and dose-dependent inhibitory effects on HuCCT-1, TFK-1 and HuH28 human CCA cell lines. EF24 inhibited CCA cell proliferation, migration, and induced G2/M phase arrest. EF24 induced cell apoptosis along with negative regulation of NF-κB- X-linked inhibitor of apoptosis protein (XIAP) signaling pathway. XIAP inhibition by lentivirus mediated RNA interference enhanced EF24-induced apoptosis, while XIAP overexpression reduced it in CCA cells. In vivo, EF24 significantly suppressed the growth of CCA tumor xenografts and tumor metastasis while displaying low toxicity levels. Our findings indicate that EF24 is a potent antitumor agent that inhibits tumor growth and metastasis by inhibiting NF-κB dependent signaling pathways. EF24 may represent a novel approach for CCA treatment. PMID:27571770

EF24 inhibits tumor growth and metastasis via suppressing NF-kappaB dependent pathways in human cholangiocarcinoma.

PubMed

Yin, Da-Long; Liang, Ying-Jian; Zheng, Tong-Sen; Song, Rui-Peng; Wang, Jia-Bei; Sun, Bo-Shi; Pan, Shang-Ha; Qu, Lian-Dong; Liu, Jia-Ren; Jiang, Hong-Chi; Liu, Lian-Xin

2016-08-30

A synthetic monoketone analog of curcumin, termed 3, 5-bis (2-flurobenzylidene) piperidin-4-one (EF24), has been reported to inhibit the growth of a variety of cancer cells both in vitro and in vivo. However, whether EF24 has anticancer effects on cholangiocarcinoma (CCA) cells and the mechanisms remain to be investigated. The aim of our study was to evaluate the molecular mechanisms underlying the anticancer effects of EF24 on CCA tumor growth and metastasis. Cell proliferation, apoptosis, migration, invasion, tumorigenesis and metastasis were examined. EF24 exhibited time- and dose-dependent inhibitory effects on HuCCT-1, TFK-1 and HuH28 human CCA cell lines. EF24 inhibited CCA cell proliferation, migration, and induced G2/M phase arrest. EF24 induced cell apoptosis along with negative regulation of NF-κB- X-linked inhibitor of apoptosis protein (XIAP) signaling pathway. XIAP inhibition by lentivirus mediated RNA interference enhanced EF24-induced apoptosis, while XIAP overexpression reduced it in CCA cells. In vivo, EF24 significantly suppressed the growth of CCA tumor xenografts and tumor metastasis while displaying low toxicity levels. Our findings indicate that EF24 is a potent antitumor agent that inhibits tumor growth and metastasis by inhibiting NF-κB dependent signaling pathways. EF24 may represent a novel approach for CCA treatment.

m6A RNA Methylation Regulates the Self-Renewal and Tumorigenesis of Glioblastoma Stem Cells

PubMed Central

Cui, Qi; Shi, Hailing; Ye, Peng; Li, Li; Qu, Qiuhao; Sun, Guoqiang; Sun, Guihua; Lu, Zhike; Huang, Yue; Yang, Cai-Guang; Riggs, Arthur D.

2017-01-01

Summary RNA modifications play critical roles in important biological processes. However, the functions of N6-methyladenosine (m6A) mRNA modification in cancer biology and cancer stem cells remain largely unknown. Here, we show that m6A mRNA modification is critical for glioblastoma stem cell (GSC) self-renewal and tumorigenesis. Knockdown of METTL3 or METTL14, key components of the RNA methyltransferase complex, dramatically promotes human GSC growth, self-renewal, and tumorigenesis. In contrast, overexpression of METTL3 or inhibition of the RNA demethylase FTO suppresses GSC growth and self-renewal. Moreover, inhibition of FTO suppresses tumor progression and prolongs lifespan of GSC-grafted mice substantially. m6A sequencing reveals that knockdown of METTL3 or METTL14 induced changes in mRNA m6A enrichment and altered mRNA expression of genes (e.g., ADAM19) with critical biological functions in GSCs. In summary, this study identifies the m6A mRNA methylation machinery as promising therapeutic targets for glioblastoma. PMID:28297667

RNF20 Suppresses Tumorigenesis by Inhibiting the SREBP1c-PTTG1 Axis in Kidney Cancer

PubMed Central

Lee, Jae Ho; Jeon, Yong Geun; Lee, Kyoung-Hwa; Lee, Hye Won; Park, Jeu; Jang, Hagoon; Kang, Minyong; Lee, Hye Sun; Cho, Hee Jin; Nam, Do-Hyun; Kwak, Cheol

2017-01-01

ABSTRACT Elevated lipid metabolism promotes cancer cell proliferation. Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancers, characterized by ectopic lipid accumulation. However, the relationship between aberrant lipid metabolism and tumorigenesis in ccRCC is not thoroughly understood. Here, we demonstrate that ring finger protein 20 (RNF20) acts as a tumor suppressor in ccRCC. RNF20 overexpression repressed lipogenesis and cell proliferation by inhibiting sterol regulatory element-binding protein 1c (SREBP1c), and SREBP1 suppression, either by knockdown or by the pharmacological inhibitor betulin, attenuated proliferation and cell cycle progression in ccRCC cells. Notably, SREBP1c regulates cell cycle progression by inducing the expression of pituitary tumor-transforming gene 1 (PTTG1), a novel target gene of SREBP1c. Furthermore, RNF20 overexpression reduced tumor growth and lipid storage in xenografts. In ccRCC patients, RNF20 downregulation and SREBP1 activation are markers of poor prognosis. Therefore, RNF20 suppresses tumorigenesis in ccRCC by inhibiting the SREBP1c-PTTG1 axis. PMID:28827316

Impaired PRC2 activity promotes transcriptional instability and favors breast tumorigenesis.

PubMed

Wassef, Michel; Rodilla, Veronica; Teissandier, Aurélie; Zeitouni, Bruno; Gruel, Nadege; Sadacca, Benjamin; Irondelle, Marie; Charruel, Margaux; Ducos, Bertrand; Michaud, Audrey; Caron, Matthieu; Marangoni, Elisabetta; Chavrier, Philippe; Le Tourneau, Christophe; Kamal, Maud; Pasmant, Eric; Vidaud, Michel; Servant, Nicolas; Reyal, Fabien; Meseure, Dider; Vincent-Salomon, Anne; Fre, Silvia; Margueron, Raphaël

2015-12-15

Alterations of chromatin modifiers are frequent in cancer, but their functional consequences often remain unclear. Focusing on the Polycomb protein EZH2 that deposits the H3K27me3 (trimethylation of Lys27 of histone H3) mark, we showed that its high expression in solid tumors is a consequence, not a cause, of tumorigenesis. In mouse and human models, EZH2 is dispensable for prostate cancer development and restrains breast tumorigenesis. High EZH2 expression in tumors results from a tight coupling to proliferation to ensure H3K27me3 homeostasis. However, this process malfunctions in breast cancer. Low EZH2 expression relative to proliferation and mutations in Polycomb genes actually indicate poor prognosis and occur in metastases. We show that while altered EZH2 activity consistently modulates a subset of its target genes, it promotes a wider transcriptional instability. Importantly, transcriptional changes that are consequences of EZH2 loss are predominantly irreversible. Our study provides an unexpected understanding of EZH2's contribution to solid tumors with important therapeutic implications. © 2015 Wassef et al.; Published by Cold Spring Harbor Laboratory Press.

Impaired PRC2 activity promotes transcriptional instability and favors breast tumorigenesis

PubMed Central

Wassef, Michel; Rodilla, Veronica; Teissandier, Aurélie; Zeitouni, Bruno; Gruel, Nadege; Sadacca, Benjamin; Irondelle, Marie; Charruel, Margaux; Ducos, Bertrand; Michaud, Audrey; Caron, Matthieu; Marangoni, Elisabetta; Chavrier, Philippe; Le Tourneau, Christophe; Kamal, Maud; Pasmant, Eric; Vidaud, Michel; Servant, Nicolas; Reyal, Fabien; Meseure, Dider; Vincent-Salomon, Anne; Fre, Silvia; Margueron, Raphaël

2015-01-01

Alterations of chromatin modifiers are frequent in cancer, but their functional consequences often remain unclear. Focusing on the Polycomb protein EZH2 that deposits the H3K27me3 (trimethylation of Lys27 of histone H3) mark, we showed that its high expression in solid tumors is a consequence, not a cause, of tumorigenesis. In mouse and human models, EZH2 is dispensable for prostate cancer development and restrains breast tumorigenesis. High EZH2 expression in tumors results from a tight coupling to proliferation to ensure H3K27me3 homeostasis. However, this process malfunctions in breast cancer. Low EZH2 expression relative to proliferation and mutations in Polycomb genes actually indicate poor prognosis and occur in metastases. We show that while altered EZH2 activity consistently modulates a subset of its target genes, it promotes a wider transcriptional instability. Importantly, transcriptional changes that are consequences of EZH2 loss are predominantly irreversible. Our study provides an unexpected understanding of EZH2's contribution to solid tumors with important therapeutic implications. PMID:26637281

miR-100 Induces Epithelial-Mesenchymal Transition but Suppresses Tumorigenesis, Migration and Invasion

PubMed Central

Chen, Dahu; Sun, Yutong; Yuan, Yuan; Han, Zhenbo; Zhang, Peijing; Zhang, Jinsong; You, M. James; Teruya-Feldstein, Julie; Wang, Min; Gupta, Sumeet; Hung, Mien-Chie; Liang, Han; Ma, Li

2014-01-01

Whether epithelial-mesenchymal transition (EMT) is always linked to increased tumorigenicity is controversial. Through microRNA (miRNA) expression profiling of mammary epithelial cells overexpressing Twist, Snail or ZEB1, we identified miR-100 as a novel EMT inducer. Surprisingly, miR-100 inhibits the tumorigenicity, motility and invasiveness of mammary tumor cells, and is commonly downregulated in human breast cancer due to hypermethylation of its host gene MIR100HG. The EMT-inducing and tumor-suppressing effects of miR-100 are mediated by distinct targets. While miR-100 downregulates E-cadherin by targeting SMARCA5, a regulator of CDH1 promoter methylation, this miRNA suppresses tumorigenesis, cell movement and invasion in vitro and in vivo through direct targeting of HOXA1, a gene that is both oncogenic and pro-invasive, leading to repression of multiple HOXA1 downstream targets involved in oncogenesis and invasiveness. These findings provide a proof-of-principle that EMT and tumorigenicity are not always associated and that certain EMT inducers can inhibit tumorigenesis, migration and invasion. PMID:24586203

MicroRNAs in thyroid development, function and tumorigenesis.

PubMed

Fuziwara, Cesar Seigi; Kimura, Edna Teruko

2017-11-15

MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that modulate the vast majority of cellular processes. During development, the correct timing and expression of miRNAs in the tissue differentiation is essential for organogenesis and functionality. In thyroid gland, DICER and miRNAs are necessary for accurately establishing thyroid follicles and hormone synthesis. Moreover, DICER1 mutations and miRNA deregulation observed in human goiter influence thyroid tumorigenesis. The thyroid malignant transformation by MAPK oncogenes is accompanied by global miRNA changes, with a marked reduction of "tumor-suppressor" miRNAs and activation of oncogenic miRNAs. Loss of thyroid cell differentiation/function, and consequently iodine trapping impairment, is an important clinical characteristic of radioiodine-refractory thyroid cancer. However, few studies have addressed the direct role of miRNAs in thyroid gland physiology. Here, we focus on what we have learned in the thyroid follicular cell differentiation and function as revealed by cell and animal models and miRNA modulation in thyroid tumorigenesis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sasa health exerts a protective effect on Her2/NeuN mammary tumorigenesis.

PubMed

Ren, Mingqiang; Reilly, R Todd; Sacchi, Nicoletta

2004-01-01

Bamboo grass leaves of different Sasa species have been widely used in food and medicine in Eastern Asia for hundreds of years. Of special interest are Kumazasa (Sasa senanensis rehder) leaves used to prepare an alkaline extract known as Sasa Health. This extract was reported to inhibit both the development and growth of mammary tumors in a mammary tumor strain of virgin SHN mice (1). We found that Sasa Health exerts a significant protective effect on spontaneous mammary tumorigenesis in another mouse model of human breast cancer, the transgenic FVB-Her2/NeuN mouse model. Two cohorts of Her2/NeuN female mice of different age (eleven-week-old and twenty-four-week-old) chronically treated with Sasa Health in drinking water showed both a delay in the development of tumors and reduced tumor multiplicity. Sasa Health also induced inhibition of mammary duct branching and side bud development in association with reduced angiogenesis. Altogether these findings indicate that Sasa Health contains phytochemicals that can effectively retard spontaneous mammary tumorigenesis.

Long noncoding RNAs and tumorigenesis: genetic associations, molecular mechanisms, and therapeutic strategies.

PubMed

Zhang, Fan; Zhang, Liang; Zhang, Caiguo

2016-01-01

The human genome contains a large number of nonprotein-coding sequences. Recently, new discoveries in the functions of nonprotein-coding sequences have demonstrated that the "Dark Genome" significantly contributes to human diseases, especially with regard to cancer. Of particular interest in this review are long noncoding RNAs (lncRNAs), which comprise a class of nonprotein-coding transcripts that are longer than 200 nucleotides. Accumulating evidence indicates that a large number of lncRNAs exhibit genetic associations with tumorigenesis, tumor progression, and metastasis. Our current understanding of the molecular bases of these lncRNAs that are associated with cancer indicate that they play critical roles in gene transcription, translation, and chromatin modification. Therapeutic strategies based on the targeting of lncRNAs to disrupt their expression or their functions are being developed. In this review, we briefly summarize and discuss the genetic associations and the aberrant expression of lncRNAs in cancer, with a particular focus on studies that have revealed the molecular mechanisms of lncRNAs in tumorigenesis. In addition, we also discuss different therapeutic strategies that involve the targeting of lncRNAs.

Evidence for possible non-canonical pathway(s) driven early-onset colorectal cancer in India

PubMed Central

Raman, Ratheesh; Kotapalli, Viswakalyan; Adduri, Raju; Gowrishankar, Swarnalata; Bashyam, Leena; Chaudhary, Ajay; Vamsy, Mohana; Patnaik, Sujith; Srinivasulu, Mukta; Sastry, Regulagadda; Rao, Subramanyeshwar; Vasala, Anjayneyulu; Kalidindi, NarasimhaRaju; Pollack, Jonathan; Murthy, Sudha; Bashyam, Murali

2012-01-01

Two genetic instability pathways viz. chromosomal instability, driven primarily by APC mutation induced deregulated Wnt signaling, and microsatellite instability (MSI) caused by mismatch repair (MMR) inactivation, together account for greater than 90% of late-onset colorectal cancer. Our understanding of early-onset sporadic CRC is however comparatively limited. In addition, most seminal studies have been performed in the western population and analyses of tumorigenesis pathway(s) causing CRC in developing nations have been rare. We performed a comparative analysis of early and late-onset CRC from India with respect to common genetic aberrations including Wnt, KRAS and p53 (constituting the classical CRC progression sequence) in addition to MSI. Our results revealed the absence of Wnt and MSI in a significant proportion of early-onset as against late-onset CRC in India. In addition, KRAS mutation frequency was significantly lower in early-onset CRC indicating that a significant proportion of CRC in India may follow tumorigenesis pathways distinct from the classical CRC progression sequence. Our study has therefore revealed the possible existence of non-canonical tumorigenesis pathways in early-onset CRC in India. PMID:23168910

Inflammation and colorectal cancer: colitis-associated neoplasia

PubMed Central

Grivennikov, Sergei I.

2013-01-01

Connection between inflammation and cancer is a rapidly developing field. Epidemiological data suggests that inflammation along with distinct arms of host immune system plays a very important role in development and progression of many different cancers. Inflammatory bowel diseases (IBD) is an important risk factor for the development of colon cancer, namely colitis-associated cancer (CAC). The molecular mechanisms by which inflammation promotes cancer development are still being uncovered and may differ between CAC and other forms of colorectal cancer. Recent work has shed light on the role of distinct immune cells, cytokines and other immune mediators in virtually all of the steps of colonic tumorigenesis, including tumor initiation and promotion as well as progression and metastasis. The close proximity of colonic tumors to the myriad of intestinal microbes, as well as instrumental role of microbiota in IBD, introduces microbes as new players capable of triggering inflammation and possibly promoting tumorigenesis. Various mechanisms of CAC tumorigenesis as well as new possible hints for the future approaches for prevention and therapy are discussed in this review. PMID:23161445

Metabolic synthetic lethality in cancer therapy.

PubMed

Zecchini, Vincent; Frezza, Christian

2017-08-01

Our understanding of cancer has recently seen a major paradigm shift resulting in it being viewed as a metabolic disorder, and altered cellular metabolism being recognised as a hallmark of cancer. This concept was spurred by the findings that the oncogenic mutations driving tumorigenesis induce a reprogramming of cancer cell metabolism that is required for unrestrained growth and proliferation. The recent discovery that mutations in key mitochondrial enzymes play a causal role in tumorigenesis suggested that dysregulation of metabolism could also be a driver of tumorigenesis. These mutations induce profound adaptive metabolic alterations that are a prerequisite for the survival of the mutated cells. Because these metabolic events are specific to cancer cells, they offer an opportunity to develop new therapies that specifically target tumour cells without affecting healthy tissue. Here, we will describe recent developments in metabolism-based cancer therapy, in particular focusing on the concept of metabolic synthetic lethality. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux. Copyright © 2016 Elsevier B.V. All rights reserved.

Dendritic Cells Program Non-Immunogenic Prostate-Specific T Cell Responses Beginning at Early Stages of Prostate Tumorigenesis

PubMed Central

Mihalyo, Marianne A.; Hagymasi, Adam T.; Slaiby, Aaron M.; Nevius, Erin E.; Adler, Adam J.

2010-01-01

BACKGROUND Prostate cancer promotes the development of T cell tolerance towards prostatic antigens, potentially limiting the efficacy of prostate cancer vaccines targeting these antigens. Here, we sought to determine the stage of disease progression when T cell tolerance develops, as well as the role of steady state dendritic cells (DC) and CD4+CD25+ T regulatory cells (Tregs) in programming tolerance. METHODS The response of naïve HA-specific CD4+ T cells were analyzed following adoptive transfer into Pro-HA × TRAMP transgenic mice harboring variably-staged HA-expressing prostate tumors on two genetic backgrounds that display different patterns and kinetics of tumorigenesis. The role of DC and Tregs in programming HA-specific CD4 cell responses were assessed via depletion. RESULTS HA-specific CD4 cells underwent non-immunogenic responses at all stages of tumorigenesis in both genetic backgrounds. These responses were completely dependent on DC, but not appreciably influenced by Tregs. CONCLUSIONS These results suggest that tolerogenicity is an early and general property of prostate tumors. PMID:17221844

Modulation of Colitis-associated Colon Tumorigenesis by Baicalein and Betaine.

PubMed

Kim, Dong Hwan; Sung, Bokyung; Chung, Hae Young; Kim, Nam Deuk

2014-09-01

In this review, we will summarize the current understanding of modulation of colitis-associated colon tumorigenesis by two natural products, baicalein and betaine, which have anti-inflammatory activities. Baicalein and betaine have been shown to provide various health benefits to organism in many ways. Baicalein is a phenolic flavonoid derived originally from the root of Scutellaria baicalensis Georgi. From ancient times, baicalein has widely been used in oriental medicines as an anti-inflammatory and anti-cancer therapy. Betaine, trimethylglycine, is an essential biochemical molecule of the methionine/homocysteine cycle and is synthesized by conversion of choline. Betaine is an important human nutrient obtained from various foods including sugar beet and lycium. Betaine has provided various health benefits including disease prevention. However, the action mechanisms of their activity remain poorly understood. Recent studies reported the effects of baicalein and betaine on cytotoxicity against colon cancer cells and chemically induced colitis-associated colon tumorigenesis in mice. Administrations of baicalein and betaine containing diets significantly inhibited the incidence of tumors and hyperplasia with down-regulation of inflammation. Therefore, baicalein and betaine might be applicable to the prevention of inflammation-associated colon carcinogenesis.

Rho-associated kinase (ROCK) function is essential for cell cycle progression, senescence and tumorigenesis

PubMed Central

Kümper, Sandra; Mardakheh, Faraz K; McCarthy, Afshan; Yeo, Maggie; Stamp, Gordon W; Paul, Angela; Worboys, Jonathan; Sadok, Amine; Jørgensen, Claus; Guichard, Sabrina

2016-01-01

Rho-associated kinases 1 and 2 (ROCK1/2) are Rho-GTPase effectors that control key aspects of the actin cytoskeleton, but their role in proliferation and cancer initiation or progression is not known. Here, we provide evidence that ROCK1 and ROCK2 act redundantly to maintain actomyosin contractility and cell proliferation and that their loss leads to cell-cycle arrest and cellular senescence. This phenotype arises from down-regulation of the essential cell-cycle proteins CyclinA, CKS1 and CDK1. Accordingly, while the loss of either Rock1 or Rock2 had no negative impact on tumorigenesis in mouse models of non-small cell lung cancer and melanoma, loss of both blocked tumor formation, as no tumors arise in which both Rock1 and Rock2 have been genetically deleted. Our results reveal an indispensable role for ROCK, yet redundant role for isoforms 1 and 2, in cell cycle progression and tumorigenesis, possibly through the maintenance of cellular contractility. DOI: http://dx.doi.org/10.7554/eLife.12203.001 PMID:26765561

Mammary Tumorigenesis and Metastasis Caused by Overexpression of Insulin Receptor Substrate 1 (IRS-1) or IRS-2▿

PubMed Central

Dearth, Robert K.; Cui, Xiaojiang; Kim, Hyun-Jung; Kuiatse, Isere; Lawrence, Nicole A.; Zhang, Xiaomei; Divisova, Jana; Britton, Ora L.; Mohsin, Syed; Allred, D. Craig; Hadsell, Darryl L.; Lee, Adrian V.

2006-01-01

Insulin receptor substrates (IRSs) are signaling adaptors that play a major role in the metabolic and mitogenic actions of insulin and insulin-like growth factors. Reports have recently noted increased levels, or activity, of IRSs in many human cancers, and some have linked this to poor patient prognosis. We found that overexpressed IRS-1 was constitutively phosphorylated in vitro and in vivo and that transgenic mice overexpressing IRS-1 or IRS-2 in the mammary gland showed progressive mammary hyperplasia, tumorigenesis, and metastasis. Tumors showed extensive squamous differentiation, a phenotype commonly seen with activation of the canonical β-catenin signaling pathway. Consistent with this, IRSs were found to bind β-catenin in vitro and in vivo. IRS-induced tumorigenesis is unique, given that the IRSs are signaling adaptors with no intrinsic kinase activity, and this supports a growing literature indicating a role for IRSs in cancer. This study defines IRSs as oncogene proteins in vivo and provides new models to develop inhibitors against IRSs for anticancer therapy. PMID:17030631

Pathology and Molecular Genetics of Pancreatic Neoplasms

PubMed Central

Wood, Laura D.; Hruban, Ralph H.

2014-01-01

Cancer is fundamentally a genetic disease caused by the ac cumulation of somatic mutations in oncogenes and tumor suppressor genes. In the last decade, rapid advances in sequencing and bioinformatic technology led to an explosion in sequencing studies of cancer genomes, greatly expanding our knowledge of the genetic changes underlying a variety of tumor types. Several of these studies of cancer genomes have focused on pancreatic neoplasms, and cancers from the pancreas are some of the best characterized tumors at the genetic level. Pancreatic neoplasms encompass a wide array of clinical diseases, from benign cysts to deadly cancers, and the genetic alterations underlying neoplasms of the pancreas are similarly diverse. This new knowledge of pancreatic cancer genomes has deepened our understanding of tumorigenesis in the pancreas and has opened several promising new avenues for novel diagnostics and therapeutics. PMID:23187835

Dietary Intervention of Artemisia and Green Tea Extracts to Rejuvenate Helicobacter pylori-Associated Chronic Atrophic Gastritis and to Prevent Tumorigenesis.

PubMed

Jeong, Migyeong; Park, Jong-Min; Han, Young-Min; Kangwan, Napapan; Kwon, Sang-Oh; Kim, Bok-Nam; Kim, Won-Hee; Hahm, Ki-Baik

2016-02-01

As nonmicrobial dietary approach is capable of controlling Helicobacter pylori infection, we evaluated the efficacy of long-term dietary administration of Artemisia and/or green tea extracts on H. pylori-initiated, high-salt-promoted chronic atrophic gastritis and gastric tumorigenesis mouse model. Helicobacter pylori-infected and high-salt-diet-administered C57BL/6 mice were administered with Artemisia extracts (MP group) and/or green tea extracts (GT group) for 36 weeks in addition to the control group (ES group, gastroprotective drug, ecabet sodium 30 mg/kg, diet pellet). Gross and pathological gastric lesions were evaluated after 24 and 36 weeks, respectively, and their underlying molecular changes were measured in gastric homogenates. Detailed mechanisms were further evaluated in in vitro cell models. The erythematous and nodular changes and mucosal ulcerative and erosive lesions were noted in the control group at 24 weeks. MP, GT, MPGT, and ES groups all showed significantly ameliorated pathologic lesion compared to the control group (p < .05). After the 36 weeks, scattered nodular masses with some central ulcers and thin gastric surface were noted in the control stomach, whereas no tumorous lesion and milder atrophic changes were observed in all MP, GT, and MPGT groups except ES group (p < .05). On molecular analysis, increased expressions of COX-2, TNF-α, IL-6, lipid peroxide, and activated STAT3 relevant to H. pylori infection were significantly decreased with MPGT administration (p < .01), whereas HSP70 was significantly increased. PGDH expressions, core tumor suppressor involved in carcinogenesis, were significantly decreased with H. pylori infection (p < .05), but significantly increased in MPGT group (p < .05). Increased mucosal apoptotic index noted in the control group was significantly decreased with MP and/or GT along with significantly preserved gastric gastroprotective mediators (p < .01) such as mucins, HSP27, and HSP70. H. pylori-induced serum TNF-α and NF-κB activations were significantly decreased with MPGT administration (p < .05). Long-term dietary intake of MP and/or GT can be an effective strategy either to rejuvenate H. pylori atrophic gastritis or to suppress tumorigenesis. © 2015 John Wiley & Sons Ltd.

Macrophages promote coal tar pitch extract-induced tumorigenesis of BEAS-2B cells and tumor metastasis in nude mice mediated by AP-1.

PubMed

Zhang, Peng; Jin, Yue-Fei; Zhang, Qiao; Wu, Yi-Ming; Wu, Wei-Dong; Yao, Wu; Wu, Yong-Jun; Li, Zhi-Tao; Zhao, Yong; Liu, Yu; Feng, Fei-Fei

2014-01-01

We sought to evaluate the role of tumor associated macrophages (TAMs) on the promotion of coal tar pitch extract (CTPE)-induced tumorigenesis of human bronchial epithelial cells (BEAS-2B) and tumor metastasis in nude mice, and related mechanisms. BEAS-2B cells were first treated with 2.4 mg/mL CTPE for 72 hours. After removal of CTPE, the cells were continuously cultured and passaged using trypsin-EDTA. THP-1 cells were used as macrophage-like cells. BEAS-2B cells under different conditions (n=6/ group) were injected into the back necks of nude mice, and alterations of tumor xenograft growth, indicative of tumorigenicity, and tumor metastasis were determined. Pathological changes (tumor nests and microvascular lesions) of HE-stained tumor tissues were also evaluated. The expression of AP-1(c-Jun) in xenografts and metastatic tumors was determined using immunohistochemistry. Tumor size and weight in nude mice transplanted with the mixture of CTPE-induced passage 30 BEAS-2B and THP-1 cells (2:1) were increased compared to those from the CTPE-treated BEAS-2B cells at passage 30 alone at different observation time points. Tumor metastasis to lymph nodes and liver was only detected after transplantation of a mixture the two kinds of cells. The numbers of tumor nests and microvascular lesions, and the expression levels of AP-1 (c-Jun) in tumors from the mixture of two kinds of cells were increased apparently in contrast to those in tumor from the CTPE-treated BEAS-2B cells of passage 30 alone. In addition, there was positive correlation between AP-1 (c-Jun) expression level and the number of microvascular lesions, or between AP-1 (c-Jun) expression level and tumor metastasis in these two groups. TAMs not only facilitate tumorigenesis transformation of CTPE-induced BEAS-2B cells, but also promote tumor growth, angiogenesis and metastasis in nude mice in vivo, which may be mediated by AP-1.

Phospholipase D2 Enhances Epidermal Growth Factor-Induced Akt Activation in EL4 Lymphoma Cells.

PubMed

Chahal, Manpreet S; Brauner, Daniel J; Meier, Kathryn E

2010-07-02

Phospholipase D2 (PLD2) generates phosphatidic acid through hydrolysis of phosphatidylcholine. PLD2 has been shown to play a role in enhancing tumorigenesis. The epidermal growth factor receptor (EGFR) can both activate and interact with PLD2. Murine lymphoma EL4 cells lacking endogenous PLD2 present a unique model to elucidate the role of PLD2 in signal transduction. In the current study, we investigated effects of PLD2 on EGF response. Western blotting and RT-PCR were used to establish that both parental cells and PLD2 transfectants express endogenous EGFR. Levels of EGFR protein are increased in cells expressing active PLD2, as compared to parental cells or cells expressing inactive PLD2. EGF stimulates proliferation of EL4 cells transfected with active PLD2, but not parental cells or cells transfected with inactive PLD2. EGF-mediated proliferation in cells expressing active PLD2 is dependent on the activities of both the EGFR and the PI3K/Akt pathway, as demonstrated by studies using protein kinase inhibitors. EGF-induced invasion through a synthetic extracellular matrix is enhanced in cells expressing active PLD2, as compared to parental cells or cells expressing inactive PLD2. Taken together, the data suggest that PLD2 acts in concert with EGFR to enhance mitogenesis and invasion in lymphoma cells.

Phospholipase D2 Enhances Epidermal Growth Factor-Induced Akt Activation in EL4 Lymphoma Cells

PubMed Central

Chahal, Manpreet S.; Brauner, Daniel J.; Meier, Kathryn E.

2010-01-01

Phospholipase D2 (PLD2) generates phosphatidic acid through hydrolysis of phosphatidylcholine. PLD2 has been shown to play a role in enhancing tumorigenesis. The epidermal growth factor receptor (EGFR) can both activate and interact with PLD2. Murine lymphoma EL4 cells lacking endogenous PLD2 present a unique model to elucidate the role of PLD2 in signal transduction. In the current study, we investigated effects of PLD2 on EGF response. Western blotting and RT-PCR were used to establish that both parental cells and PLD2 transfectants express endogenous EGFR. Levels of EGFR protein are increased in cells expressing active PLD2, as compared to parental cells or cells expressing inactive PLD2. EGF stimulates proliferation of EL4 cells transfected with active PLD2, but not parental cells or cells transfected with inactive PLD2. EGF-mediated proliferation in cells expressing active PLD2 is dependent on the activities of both the EGFR and the PI3K/Akt pathway, as demonstrated by studies using protein kinase inhibitors. EGF-induced invasion through a synthetic extracellular matrix is enhanced in cells expressing active PLD2, as compared to parental cells or cells expressing inactive PLD2. Taken together, the data suggest that PLD2 acts in concert with EGFR to enhance mitogenesis and invasion in lymphoma cells. PMID:27713341

Chronic centrosome amplification without tumorigenesis

PubMed Central

Vitre, Benjamin; Holland, Andrew J.; Kulukian, Anita; Shoshani, Ofer; Hirai, Maretoshi; Wang, Yin; Maldonado, Marcus; Cho, Thomas; Boubaker, Jihane; Swing, Deborah A.; Tessarollo, Lino; Evans, Sylvia M.; Fuchs, Elaine; Cleveland, Don W.

2015-01-01

Centrosomes are microtubule-organizing centers that facilitate bipolar mitotic spindle assembly and chromosome segregation. Recognizing that centrosome amplification is a common feature of aneuploid cancer cells, we tested whether supernumerary centrosomes are sufficient to drive tumor development. To do this, we constructed and analyzed mice in which centrosome amplification can be induced by a Cre-recombinase–mediated increase in expression of Polo-like kinase 4 (Plk4). Elevated Plk4 in mouse fibroblasts produced supernumerary centrosomes and enhanced the expected mitotic errors, but proliferation continued only after inactivation of the p53 tumor suppressor. Increasing Plk4 levels in mice with functional p53 produced centrosome amplification in liver and skin, but this did not promote spontaneous tumor development in these tissues or enhance the growth of chemically induced skin tumors. In the absence of p53, Plk4 overexpression generated widespread centrosome amplification, but did not drive additional tumors or affect development of the fatal thymic lymphomas that arise in animals lacking p53. We conclude that, independent of p53 status, supernumerary centrosomes are not sufficient to drive tumor formation. PMID:26578792

A moderate elevation of circulating levels of IGF-I does not alter ErbB2 induced mammary tumorigenesis

PubMed Central

2011-01-01

Background Epidemiological evidence suggests that moderately elevated levels of circulating insulin-like growth factor-I (IGF-I) are associated with increased risk of breast cancer in women. How circulating IGF-I may promote breast cancer incidence is unknown, however, increased IGF-I signaling is linked to trastuzumab resistance in ErbB2 positive breast cancer. Few models have directly examined the effect of moderately high levels of circulating IGF-I on breast cancer initiation and progression. The purpose of this study was to assess the ability of circulating IGF-I to independently initiate mammary tumorigenesis and/or accelerate the progression of ErbB2 mediated mammary tumor growth. Methods We crossed heterozygous TTR-IGF-I mice with heterozygous MMTV-ErbB2 mice to generate 4 different genotypes: TTR-IGF-I/MMTV-ErbB2 (bigenic), TTR-IGF-I only, MMTV-ErbB2 only, and wild type (wt). Virgin females were palpated twice a week and harvested when tumors reached 1000 mm3. For study of normal development, blood and tissue were harvested at 4, 6 and 9 weeks of age in TTR-IGF-I and wt mice. Results TTR-IGF-I and TTR-IGF-I/ErbB2 bigenic mice showed a moderate 35% increase in circulating total IGF-I compared to ErbB2 and wt control mice. Elevation of circulating IGF-I had no effect upon pubertal mammary gland development. The transgenic increase in IGF-I alone wasn't sufficient to initiate mammary tumorigenesis. Elevated circulating IGF-I had no effect upon ErbB2-induced mammary tumorigenesis or metastasis, with median time to tumor formation being 30 wks and 33 wks in TTR-IGF-I/ErbB2 bigenic and ErbB2 mice respectively (p = 0.65). Levels of IGF-I in lysates from ErbB2/TTR-IGF-I tumors compared to ErbB2 was elevated in a similar manner to the circulating IGF-I, however, there was no effect on the rate of tumor growth (p = 0.23). There were no morphological differences in tumor type (solid adenocarcinomas) between bigenic and ErbB2 mammary glands. Conclusion Using the first transgenic animal model to elevate circulating levels of IGF-I to those comparable to women at increased risk of breast cancer, we showed that moderately high levels of systemic IGF-I have no effect on pubertal mammary gland development, initiating mammary tumorigenesis or promoting ErbB2 driven mammary carcinogenesis. Our work suggests that ErbB2-induced mammary tumorigenesis is independent of the normal variation in circulating levels of IGF-I. PMID:21867536

Quantitative Proteomics Reveals the Regulatory Networks of Circular RNA CDR1as in Hepatocellular Carcinoma Cells.

PubMed

Yang, Xue; Xiong, Qian; Wu, Ying; Li, Siting; Ge, Feng

2017-10-06

Circular RNAs (circRNAs), a class of widespread endogenous RNAs, play crucial roles in diverse biological processes and are potential biomarkers in diverse human diseases and cancers. Cerebellar-degeneration-related protein 1 antisense RNA (CDR1as), an oncogenic circRNA, is involved in human tumorigenesis and is dysregulated in hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying CDR1as functions in HCC remain unclear. Here we explored the functions of CDR1as and searched for CDR1as-regulated proteins in HCC cells. A quantitative proteomics strategy was employed to globally identify CDR1as-regulated proteins in HCC cells. In total, we identified 330 differentially expressed proteins (DEPs) upon enhanced CDR1as expression in HepG2 cells, indicating that they could be proteins regulated by CDR1as. Bioinformatic analysis revealed that many DEPs were involved in cell proliferation and the cell cycle. Further functional studies of epidermal growth factor receptor (EGFR) found that CDR1as exerts its effects on cell proliferation at least in part through the regulation of EGFR expression. We further confirmed that CDR1as could inhibit the expression of microRNA-7 (miR-7). EGFR is a validated target of miR-7; therefore, CDR1as may exert its function by regulating EGFR expression via targeting miR-7 in HCC cells. Taken together, we revealed novel functions and underlying mechanisms of CDR1as in HCC cells. This study serves as the first proteome-wide analysis of a circRNA-regulated protein in cells and provides a reliable and highly efficient method for globally identifying circRNA-regulated proteins.

Inhibition of mTOR enhances radiosensitivity of lung cancer cells and protects normal lung cells against radiation.

PubMed

Zheng, Hang; Wang, Miao; Wu, Jing; Wang, Zhi-Ming; Nan, Hai-Jun; Sun, He

2016-06-01

Radiotherapy has been used for a long time as a standard therapy for cancer; however, there have been no recent research breakthroughs. Radioresistance and various side-effects lead to the unexpected outcomes of radiation therapy. Specific and accurate targeting as well as reduction of radioresistance have been major challenges for irradiation therapy. Recent studies have shown that rapamycin shows promise for inhibiting tumorigenesis by suppressing mammalian target of rapamycin (mTOR). We found that the combination of rapamycin with irradiation significantly diminished cell viability and colony formation, and increased cell apoptosis, as compared with irradiation alone in lung cancer cell line A549, suggesting that rapamycin can enhance the effectiveness of radiation therapy by sensitizing cancer cells to irradiation. Importantly, we observed that the adverse effects of irradiation on a healthy lung cell line (WI-38) were also offset. No enhanced protein expression of mTOR signaling was observed in WI-38 cells, which is normally elevated in lung cancer cells. Moreover, DNA damage was significantly less with the combination therapy than with irradiation therapy alone. Our data suggest that the incorporation of rapamycin during radiation therapy could be a potent way to improve the sensitivity and effectiveness of radiation therapy as well as to protect normal cells from being damaged by irradiation.

Expression profiling in progressive stages of fumarate-hydratase deficiency: the contribution of metabolic changes to tumorigenesis.

PubMed

Ashrafian, Houman; O'Flaherty, Linda; Adam, Julie; Steeples, Violetta; Chung, Yuen-Li; East, Phil; Vanharanta, Sakari; Lehtonen, Heli; Nye, Emma; Hatipoglu, Emine; Miranda, Melroy; Howarth, Kimberley; Shukla, Deepa; Troy, Helen; Griffiths, John; Spencer-Dene, Bradley; Yusuf, Mohammed; Volpi, Emanuela; Maxwell, Patrick H; Stamp, Gordon; Poulsom, Richard; Pugh, Christopher W; Costa, Barbara; Bardella, Chiara; Di Renzo, Maria Flavia; Kotlikoff, Michael I; Launonen, Virpi; Aaltonen, Lauri; El-Bahrawy, Mona; Tomlinson, Ian; Pollard, Patrick J

2010-11-15

Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is caused by mutations in the Krebs cycle enzyme fumarate hydratase (FH). It has been proposed that "pseudohypoxic" stabilization of hypoxia-inducible factor-α (HIF-α) by fumarate accumulation contributes to tumorigenesis in HLRCC. We hypothesized that an additional direct consequence of FH deficiency is the establishment of a biosynthetic milieu. To investigate this hypothesis, we isolated primary mouse embryonic fibroblast (MEF) lines from Fh1-deficient mice. As predicted, these MEFs upregulated Hif-1α and HIF target genes directly as a result of FH deficiency. In addition, detailed metabolic assessment of these MEFs confirmed their dependence on glycolysis, and an elevated rate of lactate efflux, associated with the upregulation of glycolytic enzymes known to be associated with tumorigenesis. Correspondingly, Fh1-deficient benign murine renal cysts and an advanced human HLRCC-related renal cell carcinoma manifested a prominent and progressive increase in the expression of HIF-α target genes and in genes known to be relevant to tumorigenesis and metastasis. In accord with our hypothesis, in a variety of different FH-deficient tissues, including a novel murine model of Fh1-deficient smooth muscle, we show a striking and progressive upregulation of a tumorigenic metabolic profile, as manifested by increased PKM2 and LDHA protein. Based on the models assessed herein, we infer that that FH deficiency compels cells to adopt an early, reversible, and progressive protumorigenic metabolic milieu that is reminiscent of that driving the Warburg effect. Targets identified in these novel and diverse FH-deficient models represent excellent potential candidates for further mechanistic investigation and therapeutic metabolic manipulation in tumors. Copyright © 2010 AACR.

Differential transmission of the molecular signature of RBSP3, LIMD1 and CDC25A in basal/ parabasal versus spinous of normal epithelium during head and neck tumorigenesis: A mechanistic study.

PubMed

Sarkar, Shreya; Alam, Neyaz; Mandal, Syam Sundar; Chatterjee, Kabita; Ghosh, Supratim; Roychoudhury, Susanta; Panda, Chinmay Kumar

2018-01-01

Head and neck squamous cell carcinoma (HNSCC) is a global disease and mortality burden, necessitating the elucidation of its molecular progression for effective disease management. The study aims to understand the molecular profile of three candidate cell cycle regulatory genes, RBSP3, LIMD1 and CDC25A in the basal/ parabasal versus spinous layer of normal oral epithelium and during head and neck tumorigenesis. Immunohistochemical expression and promoter methylation was used to determine the molecular signature in normal oral epithelium. The mechanism of alteration transmission of this profile during tumorigenesis was then explored through additional deletion and mutation in HPV/ tobacco etiological groups, followed byclinico-pathological correlation. In basal/parabasal layer, the molecular signature of the genes was low protein expression/ high promoter methylation of RBSP3, high expression/ low methylation of LIMD1 and high expression of CDC25A. Dysplastic epithelium maintained the signature of RBSP3 through high methylation/ additional deletion with loss of the signatures of LIMD1 and CDC25A via deletion/ additional methylation. Similarly, maintenance and / or loss of signature in invasive tumors was by recurrent deletion/ methylation. Thus, differential patterns of alteration of the genes might be pre-requisite for the development of dysplastic and invasive lesions. Etiological factors played a key role in promoting genetic alterations and determining prognosis. Tobacco negative HNSCC patients had significantly lower alterations of LIMD1 and CDC25A, along with better survival among tobacco negative/ HPV positive patients. Our data suggests the necessity for perturbation of normal molecular profile of RBSP3, LIMD1 and CDC25A in conjunction with etiological factors for head and neck tumorigenesis, implying their diagnostic and prognostic significance.

Interaction between Wnt/β-catenin and RAS-ERK pathways and an anti-cancer strategy via degradations of β-catenin and RAS by targeting the Wnt/β-catenin pathway.

PubMed

Jeong, Woo-Jeong; Ro, Eun Ji; Choi, Kang-Yell

2018-01-01

Aberrant activation of the Wnt/β-catenin and RAS-extracellular signal-regulated kinase (ERK) pathways play important roles in the tumorigenesis of many different types of cancer, most notably colorectal cancer (CRC). Genes for these two pathways, such as adenomatous polyposis coli ( APC ) and KRAS are frequently mutated in human CRC, and involved in the initiation and progression of the tumorigenesis, respectively. Moreover, recent studies revealed interaction of APC and KRAS mutations in the various stages of colorectal tumorigenesis and even in metastasis accompanying activation of the cancer stem cells (CSCs). A key event in the synergistic cooperation between Wnt/β-catenin and RAS-ERK pathways is a stabilization of both β-catenin and RAS especially mutant KRAS by APC loss, and pathological significance of this was indicated by correlation of increased β-catenin and RAS levels in human CRC where APC mutations occur as high as 90% of CRC patients. Together with the notion of the protein activity reduction by lowering its level, inhibition of both β-catenin and RAS especially by degradation could be a new ideal strategy for development of anti-cancer drugs for CRC. In this review, we will discuss interaction between the Wnt/β-catenin and RAS-ERK pathways in the colorectal tumorigenesis by providing the mechanism of RAS stabilization by aberrant activation of Wnt/β-catenin. We will also discuss our small molecular anti-cancer approach controlling CRC by induction of specific degradations of both β-catenin and RAS via targeting Wnt/β-catenin pathway especially for the KYA1797K, a small molecule specifically binding at the regulator of G-protein signaling (RGS)-domain of Axin.

Dysregulated Estrogen Receptor Signaling in the Hypothalamic-Pituitary-Ovarian Axis Leads to Ovarian Epithelial Tumorigenesis in Mice

PubMed Central

Laws, Mary J.; Kannan, Athilakshmi; Pawar, Sandeep; Haschek, Wanda M.; Bagchi, Milan K.; Bagchi, Indrani C.

2014-01-01

The etiology of ovarian epithelial cancer is poorly understood, mainly due to the lack of an appropriate experimental model for studying the onset and progression of this disease. We have created a mutant mouse model in which aberrant estrogen receptor alpha (ERα) signaling in the hypothalamic-pituitary-ovarian axis leads to ovarian epithelial tumorigenesis. In these mice, termed ERαd/d, the ERα gene was conditionally deleted in the anterior pituitary, but remained intact in the hypothalamus and the ovary. The loss of negative-feedback regulation by estrogen (E) at the level of the pituitary led to increased production of luteinizing hormone (LH) by this tissue. Hyperstimulation of the ovarian cells by LH resulted in elevated steroidogenesis, producing high circulating levels of steroid hormones, including E. The ERαd/d mice exhibited formation of palpable ovarian epithelial tumors starting at 5 months of age with 100% penetrance. By 15 months of age, 80% of ERαd/d mice die. Besides proliferating epithelial cells, these tumors also contained an expanded population of luteinized stromal cells, which acquire the ability to express P450 aromatase and synthesize E locally. In response to the elevated levels of E, the ERα signaling was accentuated in the ovarian epithelial cells of ERαd/d mice, triggering increased ERα-dependent gene expression, abnormal cell proliferation, and tumorigenesis. Consistent with these findings, treatment of ERαd/d mice with letrozole, an aromatase inhibitor, markedly reduced circulating E and ovarian tumor volume. We have, therefore, developed a unique animal model, which serves as a useful tool for exploring the involvement of E-dependent signaling pathways in ovarian epithelial tumorigenesis. PMID:24603706

Oral administration of aflatoxin G₁ induces chronic alveolar inflammation associated with lung tumorigenesis.

PubMed

Liu, Chunping; Shen, Haitao; Yi, Li; Shao, Peilu; Soulika, Athena M; Meng, Xinxing; Xing, Lingxiao; Yan, Xia; Zhang, Xianghong

2015-02-03

Our previous studies showed oral gavage of aflatoxin G₁ (AFG₁) induced lung adenocarcinoma in NIH mice. We recently found that a single intratracheal administration of AFG₁ caused chronic inflammatory changes in rat alveolar septum. Here, we examine whether oral gavage of AFG₁ induces chronic lung inflammation and how it contributes to carcinogenesis. We evaluated chronic lung inflammatory responses in Balb/c mice after oral gavage of AFG₁ for 1, 3 and 6 months. Inflammatory responses were heightened in the lung alveolar septum, 3 and 6 months after AFG₁ treatment, evidenced by increased macrophages and lymphocytes infiltration, up-regulation of NF-κB and p-STAT3, and cytokines production. High expression levels of superoxide dismutase (SOD-2) and hemoxygenase-1 (HO-1), two established markers of oxidative stress, were detected in alveolar epithelium of AFG₁-treated mice. Promoted alveolar type II cell (AT-II) proliferation in alveolar epithelium and angiogenesis, as well as increased COX-2 expression were also observed in lung tissues of AFG₁-treated mice. Furthermore, we prolonged survival of the mice in the above model for another 6 months to examine the contribution of AFG₁-induced chronic inflammation to lung tumorigenesis. Twelve months later, we observed that AFG₁ induced alveolar epithelial hyperplasia and adenocarcinoma in Balb/c mice. Up-regulation of NF-κB, p-STAT3, and COX-2 was also induced in lung adenocarcinoma, thus establishing a link between AFG₁-induced chronic inflammation and lung tumorigenesis. This is the first study to show that oral administration of AFG₁ could induce chronic lung inflammation, which may provide a pro-tumor microenvironment to contribute to lung tumorigenesis. Copyright © 2014. Published by Elsevier Ireland Ltd.

Kaiso overexpression promotes intestinal inflammation and potentiates intestinal tumorigenesis in Apc(Min/+) mice.

PubMed

Pierre, Christina C; Longo, Joseph; Mavor, Meaghan; Milosavljevic, Snezana B; Chaudhary, Roopali; Gilbreath, Ebony; Yates, Clayton; Daniel, Juliet M

2015-09-01

Constitutive Wnt/β-catenin signaling is a key contributor to colorectal cancer (CRC). Although inactivation of the tumor suppressor adenomatous polyposis coli (APC) is recognized as an early event in CRC development, it is the accumulation of multiple subsequent oncogenic insults facilitates malignant transformation. One potential contributor to colorectal carcinogenesis is the POZ-ZF transcription factor Kaiso, whose depletion extends lifespan and delays polyp onset in the widely used Apc(Min/+) mouse model of intestinal cancer. These findings suggested that Kaiso potentiates intestinal tumorigenesis, but this was paradoxical as Kaiso was previously implicated as a negative regulator of Wnt/β-catenin signaling. To resolve Kaiso's role in intestinal tumorigenesis and canonical Wnt signaling, we generated a transgenic mouse model (Kaiso(Tg/+)) expressing an intestinal-specific myc-tagged Kaiso transgene. We then mated Kaiso(Tg/+) and Apc(Min/+) mice to generate Kaiso(Tg/+):Apc(Min/+) mice for further characterization. Kaiso(Tg/+):Apc(Min/+) mice exhibited reduced lifespan and increased polyp multiplicity compared to Apc(Min/+) mice. Consistent with this murine phenotype, we found increased Kaiso expression in human CRC tissue, supporting a role for Kaiso in human CRC. Interestingly, Wnt target gene expression was increased in Kaiso(Tg/+):Apc(Min/+) mice, suggesting that Kaiso's function as a negative regulator of canonical Wnt signaling, as seen in Xenopus, is not maintained in this context. Notably, Kaiso(Tg/+):Apc(Min/+) mice exhibited increased inflammation and activation of NFκB signaling compared to their Apc(Min/+) counterparts. This phenotype was consistent with our previous report that Kaiso(Tg/+) mice exhibit chronic intestinal inflammation. Together our findings highlight a role for Kaiso in promoting Wnt signaling, inflammation and tumorigenesis in the mammalian intestine. Copyright © 2015 Elsevier B.V. All rights reserved.

STAT3 and STAT1 mediate IL-11–dependent and inflammation-associated gastric tumorigenesis in gp130 receptor mutant mice

PubMed Central

Ernst, Matthias; Najdovska, Meri; Grail, Dianne; Lundgren-May, Therese; Buchert, Michael; Tye, Hazel; Matthews, Vance B.; Armes, Jane; Bhathal, Prithi S.; Hughes, Norman R.; Marcusson, Eric G.; Karras, James G.; Na, Songqing; Sedgwick, Jonathon D.; Hertzog, Paul J.; Jenkins, Brendan J.

2008-01-01

Deregulated activation of STAT3 is frequently associated with many human hematological and epithelial malignancies, including gastric cancer. While exaggerated STAT3 signaling facilitates an antiapoptotic, proangiogenic, and proproliferative environment for neoplastic cells, the molecular mechanisms leading to STAT3 hyperactivation remain poorly understood. Using the gp130Y757F/Y757F mouse model of gastric cancer, which carries a mutated gp130 cytokine receptor signaling subunit that cannot bind the negative regulator of cytokine signaling SOCS3 and is characterized by hyperactivation of the signaling molecules STAT1 and STAT3, we have provided genetic evidence that IL-11 promotes chronic gastric inflammation and associated tumorigenesis. Expression of IL-11 was increased in gastric tumors in gp130Y757F/Y757F mice, when compared with unaffected gastric tissue in wild-type mice, while gp130Y757F/Y757F mice lacking the IL-11 ligand–binding receptor subunit (IL-11Rα) showed normal gastric STAT3 activation and IL-11 expression and failed to develop gastric tumors. Furthermore, reducing STAT3 activity in gp130Y757F/Y757F mice, either genetically or by therapeutic administration of STAT3 antisense oligonucleotides, normalized gastric IL-11 expression and alleviated gastric tumor burden. Surprisingly, the genetic reduction of STAT1 expression also reduced gastric tumorigenesis in gp130Y757F/Y757F mice and coincided with reduced gastric inflammation and IL-11 expression. Collectively, our data have identified IL-11 as a crucial cytokine promoting chronic gastric inflammation and associated tumorigenesis mediated by excessive activation of STAT3 and STAT1. PMID:18431520

In utero exposure to perfluorooctanoate (PFOA) or perfluorooctane sulfonate (PFOS) did not increase body weight or intestinal tumorigenesis in multiple intestinal neoplasia (Min/+) mice.

PubMed

Ngo, Ha Thi; Hetland, Ragna Bogen; Sabaredzovic, Azemira; Haug, Line Småstuen; Steffensen, Inger-Lise

2014-07-01

We examined whether perfluorooctanoate (PFOA) or perfluorooctane sulfonate (PFOS) had obesogenic effects and if they increased spontaneous intestinal tumorigenesis in the mouse model C57BL/6J-Min/+ (multiple intestinal neoplasia) after in utero exposure. The dams were exposed to PFOA or PFOS (0.01, 0.1 or 3.0mg/kg bw/day) by po gavage on GD1-17. The Min/+ and wild-type offspring were terminated at week 11 for examination of intestinal tumorigenesis or at week 20 for obesogenic effect, respectively. Body weights of the dams and pups were recorded throughout life. Food intake was determined at week 6 and 10. Blood glucose (non-fasted) was measured at week 6 and 11. No obesogenic effect of PFOA or PFOS was observed up to 20 weeks of age. PFOA or PFOS did not increase the incidence or number of tumors in the small intestine or colon of the Min/+ mice or affect their location along the intestines. Feed intake was not affected. There were some indications of toxicity of PFOA, but not of PFOS. There was lower survival of pups after 3.0mg/kg PFOA, lower body weight in pups after 3.0 and possibly 0.1mg/kg PFOA, and increased relative liver weight after 0.01 and possibly 0.1mg/kg PFOA. Plasma glucose was lower after 0.01 and 0.1mg/kg PFOA. In conclusion, exposure to PFOA and PFOS in utero with the doses used did not have obesogenic effect on either Min/+ or wild-type mice, at least not up to 11 or 20 weeks of age, nor increased intestinal tumorigenesis in Min/+ mice. Copyright © 2014 Elsevier Inc. All rights reserved.

Human natural killer cells prevent infectious mononucleosis features by targeting lytic Epstein-Barr virus infection.

PubMed

Chijioke, Obinna; Müller, Anne; Feederle, Regina; Barros, Mario Henrique M; Krieg, Carsten; Emmel, Vanessa; Marcenaro, Emanuela; Leung, Carol S; Antsiferova, Olga; Landtwing, Vanessa; Bossart, Walter; Moretta, Alessandro; Hassan, Rocio; Boyman, Onur; Niedobitek, Gerald; Delecluse, Henri-Jacques; Capaul, Riccarda; Münz, Christian

2013-12-26

Primary infection with the human oncogenic Epstein-Barr virus (EBV) can result in infectious mononucleosis (IM), a self-limiting disease caused by massive lymphocyte expansion that predisposes for the development of distinct EBV-associated lymphomas. Why some individuals experience this symptomatic primary EBV infection, whereas the majority acquires the virus asymptomatically, remains unclear. Using a mouse model with reconstituted human immune system components, we show that depletion of human natural killer (NK) cells enhances IM symptoms and promotes EBV-associated tumorigenesis mainly because of a loss of immune control over lytic EBV infection. These data suggest that failure of innate immune control by human NK cells augments symptomatic lytic EBV infection, which drives lymphocyte expansion and predisposes for EBV-associated malignancies. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Cold inducible RNA binding protein upregulation in pituitary corticotroph adenoma induces corticotroph cell proliferation via Erk signaling pathway

PubMed Central

Fu, Wei; Tang, Hao; Chen, Xiao; Zhao, Yao; Zheng, Lili; Pan, Sijian; Wang, Weiqing; Bian, Liuguan; Sun, Qingfang

2016-01-01

Cushing's disease is caused by pituitary corticotroph adenoma, and the pathogenesis of it has remained obscure. Here, we showed that cold inducible RNA binding protein (CIRP) was markedly elevated in corticotroph tumors. Forced overexpression of CIRP in murine AtT20 pituitary corticotroph cell line increased corticotroph precursor hormone proopiomelanocortin (POMC) transcription, ACTH secretion and cellular proliferation. In vivo, CIRP overexpression promotes murine corticotroph tumor growth and enhances ACTH production. Mechanistically, we show that CIRP could promote AtT20 cells proliferation by inducing cyclinD1 and decreasing p27 expression via Erk1/2 signaling pathway. Clinically, CIRP overexpression is significantly correlated with Cushing's disease recurrence. CIRP appears to play a critical tumorigenesis function in Cushing's disease and its expression might be a useful biomarker for tumor recurrence. PMID:26824322

Cited1 Deficiency Suppresses Intestinal Tumorigenesis

PubMed Central

Young, Madeleine; Poetz, Oliver; Parry, Lee; Jenkins, John R.; Williams, Geraint T.; Dunwoodie, Sally L.; Watson, Alastair; Clarke, Alan R.

2013-01-01

Conditional deletion of Apc in the murine intestine alters crypt-villus architecture and function. This process is accompanied by multiple changes in gene expression, including upregulation of Cited1, whose role in colorectal carcinogenesis is unknown. Here we explore the relevance of Cited1 to intestinal tumorigenesis. We crossed Cited1 null mice with ApcMin/+ and AhCre+Apcfl/fl mice and determined the impact of Cited1 deficiency on tumour growth/initiation including tumour multiplicity, cell proliferation, apoptosis and the transcriptome. We show that Cited1 is up-regulated in both human and murine tumours, and that constitutive deficiency of Cited1 increases survival in ApcMin/+ mice from 230.5 to 515 days. However, paradoxically, Cited1 deficiency accentuated nearly all aspects of the immediate phenotype 4 days after conditional deletion of Apc, including an increase in cell death and enhanced perturbation of differentiation, including of the stem cell compartment. Transcriptome analysis revealed multiple pathway changes, including p53, PI3K and Wnt. The activation of Wnt through Cited1 deficiency correlated with increased transcription of β-catenin and increased levels of dephosphorylated β-catenin. Hence, immediately following deletion of Apc, Cited1 normally restrains the Wnt pathway at the level of β-catenin. Thus deficiency of Cited1 leads to hyper-activation of Wnt signaling and an exaggerated Wnt phenotype including elevated cell death. Cited1 deficiency decreases intestinal tumourigenesis in ApcMin/+ mice and impacts upon a number of oncogenic signaling pathways, including Wnt. This restraint imposed by Cited1 is consistent with a requirement for Cited1 to constrain Wnt activity to a level commensurate with optimal adenoma formation and maintenance, and provides one mechanism for tumour repression in the absence of Cited1. PMID:23935526

Chemopreventive efficacy of curcumin-loaded PLGA microparticles in a transgenic mouse model of HER-2-positive breast cancer.

PubMed

Grill, Alex E; Shahani, Komal; Koniar, Brenda; Panyam, Jayanth

2018-04-01

Curcumin has shown promising inhibitory activity against HER-2-positive tumor cells in vitro but suffers from poor oral bioavailability in vivo. Our lab has previously developed a polymeric microparticle formulation for sustained delivery of curcumin for chemoprevention. The goal of this study was to examine the anticancer efficacy of curcumin-loaded polymeric microparticles in a transgenic mouse model of HER-2 cancer, Balb-neuT. Microparticles were injected monthly, and mice were examined for tumor appearance and growth. Initiating curcumin microparticle treatment at 2 or 4 weeks of age delayed tumor appearance by 2-3 weeks compared to that in control mice that received empty microparticles. At 12 weeks, abnormal (lobular hyperplasia, carcinoma in situ, and invasive carcinoma) mammary tissue area was significantly decreased in curcumin microparticle-treated mice, as was CD-31 staining. Curcumin treatment decreased mammary VEGF levels significantly, which likely contributed to slower tumor formation. When compared to saline controls, however, blank microparticles accelerated tumorigenesis and curcumin treatment abrogated this effect, suggesting that PLGA microparticles enhance tumorigenesis in this model. PLGA microparticle administration was shown to be associated with higher plasma lactic acid levels and increased activation of NF-κΒ. The unexpected side effects of PLGA microparticles may be related to the high dose of the microparticles that was needed to achieve sustained curcumin levels in vivo. Approaches that can decrease the overall dose of curcumin (for example, by increasing its potency or reducing its clearance rate) may allow the development of sustained release curcumin dosage forms as a practical approach to cancer chemoprevention.

RSPO3 expands intestinal stem cell and niche compartments and drives tumorigenesis

PubMed Central

Hilkens, John; Timmer, Nikki C; Boer, Mandy; Ikink, Gerjon J; Schewe, Matthias; Sacchetti, Andrea; Koppens, Martijn A J; Song, Ji-Ying; Bakker, Elvira R M

2017-01-01

Objective The gross majority of colorectal cancer cases results from aberrant Wnt/β-catenin signalling through adenomatous polyposis coli (APC) or CTNNB1 mutations. However, a subset of human colon tumours harbour, mutually exclusive with APC and CTNNB1 mutations, gene fusions in RSPO2 or RSPO3, leading to enhanced expression of these R-spondin genes. This suggested that RSPO activation can substitute for the most common mutations as an alternative driver for intestinal cancer. Involvement of RSPO3 in tumour growth was recently shown in RSPO3-fusion-positive xenograft models. The current study determines the extent into which solely a gain in RSPO3 actually functions as a driver of intestinal cancer in a direct, causal fashion, and addresses the in vivo activities of RSPO3 in parallel. Design We generated a conditional Rspo3 transgenic mouse model in which the Rspo3 transgene is expressed upon Cre activity. Cre is provided by cross-breeding with Lgr5-GFP-CreERT2 mice. Results Upon in vivo Rspo3 expression, mice rapidly developed extensive hyperplastic, adenomatous and adenocarcinomatous lesions throughout the intestine. RSPO3 induced the expansion of Lgr5+ stem cells, Paneth cells, non-Paneth cell label-retaining cells and Lgr4+ cells, thus promoting both intestinal stem cell and niche compartments. Wnt/β-catenin signalling was modestly increased upon Rspo3 expression and mutant Kras synergised with Rspo3 in hyperplastic growth. Conclusions We provide in vivo evidence that RSPO3 stimulates the crypt stem cell and niche compartments and drives rapid intestinal tumorigenesis. This establishes RSPO3 as a potent driver of intestinal cancer and proposes RSPO3 as a candidate target for therapy in patients with colorectal cancer harbouring RSPO3 fusions. PMID:27511199

Inactivation of the Carney complex gene 1 (PRKAR1A) alters spatiotemporal regulation of cAMP and cAMP-dependent protein kinase: a study using genetically encoded FRET-based reporters.

PubMed

Cazabat, Laure; Ragazzon, Bruno; Varin, Audrey; Potier-Cartereau, Marie; Vandier, Christophe; Vezzosi, Delphine; Risk-Rabin, Marthe; Guellich, Aziz; Schittl, Julia; Lechêne, Patrick; Richter, Wito; Nikolaev, Viacheslav O; Zhang, Jin; Bertherat, Jérôme; Vandecasteele, Grégoire

2014-03-01

Carney complex (CNC) is a hereditary disease associating cardiac myxoma, spotty skin pigmentation and endocrine overactivity. CNC is caused by inactivating mutations in the PRKAR1A gene encoding PKA type I alpha regulatory subunit (RIα). Although PKA activity is enhanced in CNC, the mechanisms linking PKA dysregulation to endocrine tumorigenesis are poorly understood. In this study, we used Förster resonance energy transfer (FRET)-based sensors for cAMP and PKA activity to define the role of RIα in the spatiotemporal organization of the cAMP/PKA pathway. RIα knockdown in HEK293 cells increased basal as well as forskolin or prostaglandin E1 (PGE1)-stimulated total cellular PKA activity as reported by western blots of endogenous PKA targets and the FRET-based global PKA activity reporter, AKAR3. Using variants of AKAR3 targeted to subcellular compartments, we identified similar increases in the response to PGE1 in the cytoplasm and at the outer mitochondrial membrane. In contrast, at the plasma membrane, the response to PGE1 was decreased along with an increase in basal FRET ratio. These results were confirmed by western blot analysis of basal and PGE1-induced phosphorylation of membrane-associated vasodilator-stimulated phosphoprotein. Similar differences were observed between the cytoplasm and the plasma membrane in human adrenal cells carrying a RIα inactivating mutation. RIα inactivation also increased cAMP in the cytoplasm, at the outer mitochondrial membrane and at the plasma membrane, as reported by targeted versions of the cAMP indicator Epac1-camps. These results show that RIα inactivation leads to multiple, compartment-specific alterations of the cAMP/PKA pathway revealing new aspects of signaling dysregulation in tumorigenesis.

Low-dose or low-dose-rate ionizing radiation–induced bioeffects in animal models

PubMed Central

Loke, Weng Keong; Khoo, Boo Cheong

2017-01-01

Abstract Animal experimental studies indicate that acute or chronic low-dose ionizing radiation (LDIR) (≤100 mSv) or low-dose-rate ionizing radiation (LDRIR) (<6 mSv/h) exposures may be harmful. It induces genetic and epigenetic changes and is associated with a range of physiological disturbances that includes altered immune system, abnormal brain development with resultant cognitive impairment, cataractogenesis, abnormal embryonic development, circulatory diseases, weight gain, premature menopause in female animals, tumorigenesis and shortened lifespan. Paternal or prenatal LDIR/LDRIR exposure is associated with reduced fertility and number of live fetuses, and transgenerational genomic aberrations. On the other hand, in some experimental studies, LDIR/LDRIR exposure has also been reported to bring about beneficial effects such as reduction in tumorigenesis, prolonged lifespan and enhanced fertility. The differences in reported effects of LDIR/LDRIR exposure are dependent on animal genetic background (susceptibility), age (prenatal or postnatal days), sex, nature of radiation exposure (i.e. acute, fractionated or chronic radiation exposure), type of radiation, combination of radiation with other toxic agents (such as smoking, pesticides or other chemical toxins) or animal experimental designs. In this review paper, we aimed to update radiation researchers and radiologists on the current progress achieved in understanding the LDIR/LDRIR-induced bionegative and biopositive effects reported in the various animal models. The roles played by a variety of molecules that are implicated in LDIR/LDRIR-induced health effects will be elaborated. The review will help in future investigations of LDIR/LDRIR-induced health effects by providing clues for designing improved animal research models in order to clarify the current controversial/contradictory findings from existing studies. PMID:28077626

Epithelial neoplasia coincides with exacerbated injury and fibrotic response in the lungs of Gprc5a-knockout mice following silica exposure

PubMed Central

Zhong, Shuangshuang; Song, Hongyong; Sun, Beibei; Zhou, Binhua P.; Deng, Jiong; Han, Baohui

2015-01-01

Exposure to crystalline silica is suggested to increase the risk for a variety of lung diseases, including fibrosis and lung cancer. However, epidemiological evidences for the exposure-risk relationship are ambiguous and conflicting, and experimental study from a reliable animal model to explore the relationship is lacking. We reasoned that a mouse model that is sensitive to both lung injury and tumorigenesis would be appropriate to evaluate the exposure-risk relationship. Previously, we showed that, Gprc5a−/− mice are susceptible to both lung tumorigenesis and endotoxin-induced acute lung injury. In this study, we investigated the biological consequences in Gprc5a−/− mouse model following silica exposure. Intra-tracheal administration of fine silica particles in Gprc5a−/− mice resulted in more severe lung injury and pulmonary inflammation than in wild-type mice. Moreover, an enhanced fibrogenic response, including EMT-like characteristics, was induced in the lungs of Gprc5a−/− mice compared to those from wild-type ones. Importantly, increased hyperplasia or neoplasia coincided with silica-induced tissue injury and fibrogenic response in lungs from Gprc5a−/− mice. Consistently, expression of MMP9, TGFβ1 and EGFR was significantly increased in lungs from silica-treated Gprc5a−/− mice compared to those untreated or wild-type ones. These results suggest that, the process of tissue repair coincides with tissue damages; whereas persistent tissue damages leads to abnormal repair or neoplasia. Thus, silica-induced pulmonary inflammation and injury contribute to increased neoplasia development in lungs from Gprc5a−/− mouse model. PMID:26447616

EIF3C-enhanced exosome secretion promotes angiogenesis and tumorigenesis of human hepatocellular carcinoma

PubMed Central

Lee, Hsin-Yi; Chen, Chi-Kuan; Ho, Chun-Ming; Lee, Szu-Shuo; Chang, Chieh-Yu; Chen, Kuan-Ju; Jou, Yuh-Shan

2018-01-01

Targeting tumor angiogenesis is a common strategy against human hepatocellular carcinoma (HCC). However, identification of molecular targets as biomarker for elevating therapeutic efficacy is critical to prolong HCC patient survival. Here, we showed that EIF3C (eukaryotic translation initiation factor 3 subunit C) is upregulated during HCC tumor progression and associated with poor patient survival. Expression of EIF3C did not alter proliferation and expression of other tumor progressive genes such as HIF1A, TGFβ1 and VEGF, but reduced cell migration in HCC cells. Nevertheless, expression of EIF3C in HCC cells significantly increase secretion of extracellular exosomes confirmed by increased exosomes labelling by PKH26 fluorescent dye, vesicles in exosome size detected by electronic microscopy and nanoparticle tracking analysis, and expression of divergent exosome markers. The EIF3C-increased exosomes were oncogenic to potentiate tumor angiogenesis via tube formation of HUVEC cells and growth of vessels by plugs assays on nude mice. Subcutaneous inoculation of EIF3C-exosomes mixed with Huh7 HCC cells not only promoted growth of vessels but also increased expression of EIF3C in tumors. Conversely, treatment of exosome inhibitor GW4869 reversed aforementioned oncogenic assays. We identified EIF3C activated expression of S100A11 involved in EIF3C-exosome increased tube formation in angiogenesis. Simultaneous high expression of EIF3C and S100A11 in human HCC tumors for RNA level in TCGA and protein level by IHC are associated with poor survival of HCC patients. Collectively, our results demonstrated that EIF3C overexpression is a potential target of angiogenesis for treatment with exosome inhibitor or S100A11 reduction to suppress HCC angiogenesis and tumorigenesis. PMID:29568350

TCF7L1 recruits CtBP and HDAC1 to repress DICKKOPF4 gene expression in human colorectal cancer cells

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

Eshelman, Melanie A.; Shah, Meera; Raup-Konsavage, Wesley M.

The T-cell factor/Lymphoid enhancer factor (TCF/LEF; hereafter TCF) family of transcription factors are critical regulators of colorectal cancer (CRC) cell growth. Of the four TCF family members, TCF7L1 functions predominantly as a repressor of gene expression. Few studies have addressed the role of TCF7L1 in CRC and only a handful of target genes regulated by this repressor are known. By silencing TCF7L1 expression in HCT116 cells, we show that it promotes cell proliferation and tumorigenesis in vivo by driving cell cycle progression. Microarray analysis of transcripts differentially expressed in control and TCF7L1-silenced CRC cells identified genes that control cell cycle kinetics andmore » cancer pathways. Among these, expression of the Wnt antagonist DICKKOPF4 (DKK4) was upregulated when TCF7L1 levels were reduced. We found that TCF7L1 recruits the C-terminal binding protein (CtBP) and histone deacetylase 1 (HDAC1) to the DKK4 promoter to repress DKK4 gene expression. In the absence of TCF7L1, TCF7L2 and β-catenin occupancy at the DKK4 promoter is stimulated and DKK4 expression is increased. These findings uncover a critical role for TCF7L1 in repressing DKK4 gene expression to promote the oncogenic potential of CRCs. - Highlights: • TCF7L1 promotes colorectal cancer cell proliferation and tumorigenesis. • DICKKOPF4 is directly regulated by TCF7L1. • TCF7L1 recruits CtBP and HDAC1 to repress DKK4 gene expression.« less

C/EBPbeta represses p53 to promote cell survival downstream of DNA damage independent of oncogenic Ras and p19(Arf).

PubMed

Ewing, S J; Zhu, S; Zhu, F; House, J S; Smart, R C

2008-11-01

CCAAT/enhancer-binding protein-beta (C/EBPbeta) is a mediator of cell survival and tumorigenesis. When C/EBPbeta(-/-) mice are treated with carcinogens that produce oncogenic Ras mutations in keratinocytes, they respond with abnormally elevated keratinocyte apoptosis and a block in skin tumorigenesis. Although this aberrant carcinogen-induced apoptosis results from abnormal upregulation of p53, it is not known whether upregulated p53 results from oncogenic Ras and its ability to induce p19(Arf) and/or activate DNA-damage response pathways or from direct carcinogen-induced DNA damage. We report that p19(Arf) is dramatically elevated in C/EBPbeta(-/-) epidermis and that C/EBPbeta represses a p19(Arf) promoter reporter. To determine whether p19(Arf) is responsible for the proapoptotic phenotype in C/EBPbeta(-/-) mice, C/EBPbeta(-/-);p19(Arf-/-) mice were generated. C/EBPbeta(-/-);p19(Arf-/-) mice responded to carcinogen treatment with increased p53 and apoptosis, indicating p19(Arf) is not essential. To ascertain whether oncogenic Ras activation induces aberrant p53 and apoptosis in C/EBPbeta(-/-) epidermis, we generated K14-ER:Ras;C/EBPbeta(-/-) mice. Oncogenic Ras activation induced by 4-hydroxytamoxifen did not produce increased p53 or apoptosis. Finally, when C/EBPbeta(-/-) mice were treated with differing types of DNA-damaging agents, including alkylating chemotherapeutic agents, they displayed aberrant levels of p53 and apoptosis. These results indicate that C/EBPbeta represses p53 to promote cell survival downstream of DNA damage and suggest that inhibition of C/EBPbeta may be a target for cancer cotherapy to increase the efficacy of alkylating chemotherapeutic agents.

C/EBPβ represses p53 to promote cell survival downstream of DNA damage independent of oncogenic Ras and p19Arf

PubMed Central

Ewing, SJ; Zhu, S; Zhu, F; House, JS; Smart, RC

2013-01-01

CCAAT/enhancer-binding protein-β (C/EBPβ) is a mediator of cell survival and tumorigenesis. When C/EBPβ−/− mice are treated with carcinogens that produce oncogenic Ras mutations in keratinocytes, they respond with abnormally elevated keratinocyte apoptosis and a block in skin tumorigenesis. Although this aberrant carcinogen-induced apoptosis results from abnormal upregulation of p53, it is not known whether upregulated p53 results from oncogenic Ras and its ability to induce p19Arf and/or activate DNA-damage response pathways or from direct carcinogen-induced DNA damage. We report that p19Arf is dramatically elevated in C/EBPβ−/− epidermis and that C/EBPβ represses a p19Arf promoter reporter. To determine whether p19Arf is responsible for the proapoptotic phenotype in C/EBPβ−/− mice, C/EBPβ−/−;p19Arf−/− mice were generated. C/EBPβ−/−;p19Arf−/− mice responded to carcinogen treatment with increased p53 and apoptosis, indicating p19Arf is not essential. To ascertain whether oncogenic Ras activation induces aberrant p53 and apoptosis in C/EBPβ−/− epidermis, we generated K14-ER:Ras; C/EBPβ−/− mice. Oncogenic Ras activation induced by 4-hydroxytamoxifen did not produce increased p53 or apoptosis. Finally, when C/EBPβ−/− mice were treated with differing types of DNA-damaging agents, including alkylating chemotherapeutic agents, they displayed aberrant levels of p53 and apoptosis. These results indicate that C/EBPβ represses p53 to promote cell survival downstream of DNA damage and suggest that inhibition of C/EBPβ may be a target for cancer cotherapy to increase the efficacy of alkylating chemotherapeutic agents. PMID:18636078

MicroRNA in Metabolic Re-Programming and Their Role in Tumorigenesis

PubMed Central

Tomasetti, Marco; Amati, Monica; Santarelli, Lory; Neuzil, Jiri

2016-01-01

The process of metabolic re-programing is linked to the activation of oncogenes and/or suppression of tumour suppressor genes, which are regulated by microRNAs (miRNAs). The interplay between oncogenic transformation-driven metabolic re-programming and modulation of aberrant miRNAs further established their critical role in the initiation, promotion and progression of cancer by creating a tumorigenesis-prone microenvironment, thus orchestrating processes of evasion to apoptosis, angiogenesis and invasion/migration, as well metastasis. Given the involvement of miRNAs in tumour development and their global deregulation, they may be perceived as biomarkers in cancer of therapeutic relevance. PMID:27213336

Stromagenesis: the changing face of fibroblastic microenvironments during tumor progression.

PubMed

Beacham, Dorothy A; Cukierman, Edna

2005-10-01

During tumorigenesis, reciprocal changes in stromal fibroblasts and tumor cells induce changes to the neoplastic microenvironmental landscape. In stromagenesis, both the complex network of bi-directional stromal fibroblastic signaling pathways and the stromal extracellular matrix are modified. The presence of a 'primed' stroma during the early, reversible stage of tumorigenesis is optimal for stromal-directed therapeutic intervention. Three-dimensional (3D) cell culture systems have been developed that mimic the in vivo microenvironment. These systems provide unique experimental tools to identify early alterations in stromagenesis that are supportive of tumor progression with the ultimate goal of blocking neoplastic permissiveness and restoring normal phenotypes.

Adrenocortical neoplasia: evolving concepts in tumorigenesis with an emphasis on adrenal cortical carcinoma variants.

PubMed

de Krijger, Ronald R; Papathomas, Thomas G

2012-01-01

Adrenocortical carcinoma (ACC) is a rare, heterogeneous malignancy with a poor prognosis. According to WHO classification 2004, ACC variants include oncocytic ACCs, myxoid ACCs and ACCs with sarcomatous areas. Herein, we provide a comprehensive review of these rare subtypes of adrenocortical malignancy and emphasize their clinicopathological features with the aim of elucidating aspects of diagnostic categorization, differential diagnostics and biological behavior. The issue of current terminology, applied to biphasic tumors with pleomorphic, sarcomatous or sarcomatoid elements arising in adrenal cortex, is also discussed. We additionally present emerging evidence concerning the adrenal cortical tumorigenesis and the putative adenoma-carcinoma sequence as well.

Not so Fast: Co-Requirements for Sonic Hedgehog Induced Brain Tumorigenesis.

PubMed

Ward, Stacey A; Rubin, Joshua B

2015-08-06

The Sonic hedgehog (Shh) pathway plays an integral role in cellular proliferation during normal brain development and also drives growth in a variety of cancers including brain cancer. Clinical trials of Shh pathway inhibitors for brain tumors have yielded disappointing results, indicating a more nuanced role for Shh signaling. We postulate that Shh signaling does not work alone but requires co-activation of other signaling pathways for tumorigenesis and stem cell maintenance. This review will focus on the interplay between the Shh pathway and these pathways to promote tumor growth in brain tumors, presenting opportunities for the study of combinatorial therapies.

Hedgehog Signaling Regulates Epithelial-Mesenchymal Transition in Pancreatic Cancer Stem-Like Cells

PubMed Central

Wang, Feng; Ma, Ling; Zhang, Zhengkui; Liu, Xiaoran; Gao, Hongqiao; Zhuang, Yan; Yang, Pei; Kornmann, Marko; Tian, Xiaodong; Yang, Yinmo

2016-01-01

Hedgehog (Hh) signaling is crucially involved in tumorigenesis. This study aimed to assess the role of Hh signaling in the regulation of epithelial-mesenchymal transition (EMT), stemness properties and chemoresistance of human pancreatic Panc-1 cancer stem cells (CSCs). Panc-1 cells were transfected with recombinant lentiviral vectors to silence SMO and serum-free floating-culture system was used to isolate Panc-1 tumorspheres. The expression of CSC and EMT markers was detected by flow cytometry, real-time RT-PCR and Western blot analysis. Malignant behaviors of Panc-1 CSC were evaluated by tumorigenicity assays and nude mouse lung metastasis model. We found that tumorspheres derived from pancreatic cancer cell line Panc-1 possessed self-renewal, differentiation and stemness properties. Hh pathway and EMT were active in Panc-1 tumorspheres. Inhibition of Hh signaling by SMO knockdown inhibited self-renewal, EMT, invasion, chemoresistance, pulmonary metastasis, tumorigenesis of pancreatic CSCs. In conclusion, Hh signaling contributes to the maintenance of stem-like properties and chemoresistance of pancreatic CSC and promotes the tumorigenesis and metastasis of pancreatic cancer. Hh pathway is a potential molecular target for the development of therapeutic strategies for pancreatic CSCs. PMID:26918054

Dissecting Stages of Human Kidney Development and Tumorigenesis with Surface Markers Affords Simple Prospective Purification of Nephron Stem Cells.

PubMed

Pode-Shakked, Naomi; Pleniceanu, Oren; Gershon, Rotem; Shukrun, Rachel; Kanter, Itamar; Bucris, Efrat; Pode-Shakked, Ben; Tam, Gal; Tam, Hadar; Caspi, Revital; Pri-Chen, Sara; Vax, Einav; Katz, Guy; Omer, Dorit; Harari-Steinberg, Orit; Kalisky, Tomer; Dekel, Benjamin

2016-03-29

When assembling a nephron during development a multipotent stem cell pool becomes restricted as differentiation ensues. A faulty differentiation arrest in this process leads to transformation and initiation of a Wilms' tumor. Mapping these transitions with respective surface markers affords accessibility to specific cell subpopulations. NCAM1 and CD133 have been previously suggested to mark human renal progenitor populations. Herein, using cell sorting, RNA sequencing, in vitro studies with serum-free media and in vivo xenotransplantation we demonstrate a sequential map that links human kidney development and tumorigenesis; In nephrogenesis, NCAM1(+)CD133(-) marks SIX2(+) multipotent renal stem cells transiting to NCAM1(+)CD133(+) differentiating segment-specific SIX2(-) epithelial progenitors and NCAM1(-)CD133(+) differentiated nephron cells. In tumorigenesis, NCAM1(+)CD133(-) marks SIX2(+) blastema that includes the ALDH1(+) WT cancer stem/initiating cells, while NCAM1(+)CD133(+) and NCAM1(-)CD133(+) specifying early and late epithelial differentiation, are severely restricted in tumor initiation capacity and tumor self-renewal. Thus, negative selection for CD133 is required for defining NCAM1(+) nephron stem cells in normal and malignant nephrogenesis.

NLRP12 Suppresses Colon Inflammation and Tumorigenesis through the Negative Regulation of Non-canonical NF-κB Signaling and MAP Kinase Activation

PubMed Central

Allen, Irving C.; Wilson, Justin E.; Schneider, Monika; Lich, John D.; Roberts, Reid A.; Arthur, Janelle C.; Woodford, Rita-Marie T.; Davis, Beckley K.; Uronis, Joshua M.; Herfarth, Hans H.; Jobin, Christian; Rogers, Arlin B.; Ting, Jenny P.-Y.

2013-01-01

SUMMARY In vitro data suggest that a subgroup of NLR proteins, including NLRP12, inhibits the transcription factor NF-κB, although physiologic and disease-relevant evidence is largely missing. Dysregulated NF-κB activity is associated with colonic inflammation and cancer, and we found Nlrp12-/- mice were highly susceptible to colitis and colitis-associated colon cancer. Polyps isolated from Nlrp12-/- mice showed elevated non-canonical NF-κB activation and increased expression of target genes that were associated with cancer, including Cxcl13 and Cxcl12. NLRP12 negatively regulated ERK and AKT signaling pathways in affected tumor tissues. Both hematopoietic and nonhematopoietic-derived NLRP12 contributed to inflammation, but the latter dominantly contributed to tumorigenesis. The non-canonical NF-κB pathway was regulated upon degradation of TRAF3 and activation of NIK. NLRP12 interacted with both NIK and TRAF3, and Nlrp12-/- cells have constitutively elevated NIK, p100 processing to p52 and reduced TRAF3. Thus, NLRP12 is a checkpoint of noncanonical NF-κB, inflammation and tumorigenesis. PMID:22503542

The tobacco-specific carcinogen-operated calcium channel promotes lung tumorigenesis via IGF2 exocytosis in lung epithelial cells

PubMed Central

Boo, Hye-Jin; Min, Hye-Young; Jang, Hyun-Ji; Yun, Hye Jeong; Smith, John Kendal; Jin, Quanri; Lee, Hyo-Jong; Liu, Diane; Kweon, Hee-Seok; Behrens, Carmen; Lee, J. Jack; Wistuba, Ignacio I.; Lee, Euni; Hong, Waun Ki; Lee, Ho-Young

2016-01-01

Nicotinic acetylcholine receptors (nAChRs) binding to the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induces Ca2+ signalling, a mechanism that is implicated in various human cancers. In this study, we investigated the role of NNK-mediated Ca2+ signalling in lung cancer formation. We show significant overexpression of insulin-like growth factors (IGFs) in association with IGF-1R activation in human preneoplastic lung lesions in smokers. NNK induces voltage-dependent calcium channel (VDCC)-intervened calcium influx in airway epithelial cells, resulting in a rapid IGF2 secretion via the regulated pathway and thus IGF-1R activation. Silencing nAChR, α1 subunit of L-type VDCC, or various vesicular trafficking curators, including synaptotagmins and Rabs, or blockade of nAChR/VDCC-mediated Ca2+ influx significantly suppresses NNK-induced IGF2 exocytosis, transformation and tumorigenesis of lung epithelial cells. Publicly available database reveals inverse correlation between use of calcium channel blockers and lung cancer diagnosis. Our data indicate that NNK disrupts the regulated pathway of IGF2 exocytosis and promotes lung tumorigenesis. PMID:27666821

Transforming Growth Factor-Beta and Oxidative Stress Interplay: Implications in Tumorigenesis and Cancer Progression

PubMed Central

Krstić, Jelena; Trivanović, Drenka; Mojsilović, Slavko; Santibanez, Juan F.

2015-01-01

Transforming growth factor-beta (TGF-β) and oxidative stress/Reactive Oxygen Species (ROS) both have pivotal roles in health and disease. In this review we are analyzing the interplay between TGF-β and ROS in tumorigenesis and cancer progression. They have contradictory roles in cancer progression since both can have antitumor effects, through the induction of cell death, senescence and cell cycle arrest, and protumor effects by contributing to cancer cell spreading, proliferation, survival, and metastasis. TGF-β can control ROS production directly or by downregulating antioxidative systems. Meanwhile, ROS can influence TGF-β signaling and increase its expression as well as its activation from the latent complex. This way, both are building a strong interplay which can be taken as an advantage by cancer cells in order to increment their malignancy. In addition, both TGF-β and ROS are able to induce cell senescence, which in one way protects damaged cells from neoplastic transformation but also may collaborate in cancer progression. The mutual collaboration of TGF-β and ROS in tumorigenesis is highly complex, and, due to their differential roles in tumor progression, careful consideration should be taken when thinking of combinatorial targeting in cancer therapies. PMID:26078812

The tobacco-specific carcinogen-operated calcium channel promotes lung tumorigenesis via IGF2 exocytosis in lung epithelial cells.

PubMed

Boo, Hye-Jin; Min, Hye-Young; Jang, Hyun-Ji; Yun, Hye Jeong; Smith, John Kendal; Jin, Quanri; Lee, Hyo-Jong; Liu, Diane; Kweon, Hee-Seok; Behrens, Carmen; Lee, J Jack; Wistuba, Ignacio I; Lee, Euni; Hong, Waun Ki; Lee, Ho-Young

2016-09-26

Nicotinic acetylcholine receptors (nAChRs) binding to the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) induces Ca 2+ signalling, a mechanism that is implicated in various human cancers. In this study, we investigated the role of NNK-mediated Ca 2+ signalling in lung cancer formation. We show significant overexpression of insulin-like growth factors (IGFs) in association with IGF-1R activation in human preneoplastic lung lesions in smokers. NNK induces voltage-dependent calcium channel (VDCC)-intervened calcium influx in airway epithelial cells, resulting in a rapid IGF2 secretion via the regulated pathway and thus IGF-1R activation. Silencing nAChR, α1 subunit of L-type VDCC, or various vesicular trafficking curators, including synaptotagmins and Rabs, or blockade of nAChR/VDCC-mediated Ca 2+ influx significantly suppresses NNK-induced IGF2 exocytosis, transformation and tumorigenesis of lung epithelial cells. Publicly available database reveals inverse correlation between use of calcium channel blockers and lung cancer diagnosis. Our data indicate that NNK disrupts the regulated pathway of IGF2 exocytosis and promotes lung tumorigenesis.

Hedgehog Signaling Regulates Epithelial-Mesenchymal Transition in Pancreatic Cancer Stem-Like Cells.

PubMed

Wang, Feng; Ma, Ling; Zhang, Zhengkui; Liu, Xiaoran; Gao, Hongqiao; Zhuang, Yan; Yang, Pei; Kornmann, Marko; Tian, Xiaodong; Yang, Yinmo

2016-01-01

Hedgehog (Hh) signaling is crucially involved in tumorigenesis. This study aimed to assess the role of Hh signaling in the regulation of epithelial-mesenchymal transition (EMT), stemness properties and chemoresistance of human pancreatic Panc-1 cancer stem cells (CSCs). Panc-1 cells were transfected with recombinant lentiviral vectors to silence SMO and serum-free floating-culture system was used to isolate Panc-1 tumorspheres. The expression of CSC and EMT markers was detected by flow cytometry, real-time RT-PCR and Western blot analysis. Malignant behaviors of Panc-1 CSC were evaluated by tumorigenicity assays and nude mouse lung metastasis model. We found that tumorspheres derived from pancreatic cancer cell line Panc-1 possessed self-renewal, differentiation and stemness properties. Hh pathway and EMT were active in Panc-1 tumorspheres. Inhibition of Hh signaling by SMO knockdown inhibited self-renewal, EMT, invasion, chemoresistance, pulmonary metastasis, tumorigenesis of pancreatic CSCs. In conclusion, Hh signaling contributes to the maintenance of stem-like properties and chemoresistance of pancreatic CSC and promotes the tumorigenesis and metastasis of pancreatic cancer. Hh pathway is a potential molecular target for the development of therapeutic strategies for pancreatic CSCs.

Long noncoding RNA LINC00858 promotes osteosarcoma through regulating miR-139-CDK14 axis.

PubMed

Gu, Zenghui; Hou, Zhenhai; Zheng, Longbao; Wang, Xinqiang; Wu, Liangbang; Zhang, Cheng

2018-06-23

Long noncoding RNAs (lncRNAs) have been identified to modulate the tumorigenesis of human cancers. The in-depth of lncRNAs on human osteosarcoma oncogenesis is still ambiguous. In present study, functional and mechanism experiments were conducted to investigate the role of long intergenic non-protein coding RNA 00858 (LINC00858) on human osteosarcoma tumorigenesis. Results demonstrated that LINC00858 expression was significantly upregulated in both osteosarcoma tissues and cell lines. Mechanism assays presented that LINC00858 silencing significantly repressed osteosarcoma cells' proliferation and invasion in vitro, and inhibited the tumor growth in vivo. In further experiments, LINC00858 was identified to sponge miR-139 to form RNA-induced silencing complex (RISC) using luciferase reporter assay and RNA immunoprecipitation (RIP). Besides, CDK14 was validated to be the target protein the miR-139. Rescue experiments confirmed the role of LINC00858/miR-139/CDK14 pathway on osteosarcoma cells' phenotype. In summary, these data prove that LINC00858/miR-139/CDK14 axis promotes the tumorigenesis of osteosarcoma, providing a new mechanism or target for osteosarcoma. Copyright © 2018. Published by Elsevier Inc.

SUMOylated MAFB promotes colorectal cancer tumorigenesis

PubMed Central

Xie, Yin-Yin; Sun, Xiao-Jian; Zhao, Ren; Huang, Qiu-Hua

2016-01-01

The transcription factor, v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB), promotes tumorigenesis in some cancers. In this study, we found that MAFB levels were increased in clinical colorectal cancer (CRC) samples, and higher expression correlated with more advanced TNM stage. We identified MAFB amplifications in a majority of tumor types in an assessment of The Cancer Genome Atlas database. Altered MAFB levels due to gene amplification, deletion, mutation, or transcription upregulation occurred in 9% of CRC cases within the database. shRNA knockdown experiments demonstrated that MAFB deficiency blocked CRC cell proliferation by arresting the cell cycle at G0/G1 phase in vitro. We found that MAFB could be SUMOylated by SUMO1 at lysine 32, and this modification was critical for cell cycle regulation by MAFB in CRC cells. SUMOylated MAFB directly regulated cyclin-dependent kinase 6 transcription by binding to its promoter. MAFB knockdown CRC cell xenograft tumors in mice grew more slowly than controls, and wild-type MAFB-overexpressing tumors grew more quickly than tumors overexpressing MAFB mutated at lysine 32. These data suggest that SUMOylated MAFB promotes CRC tumorigenesis through cell cycle regulation. MAFB and its SUMOylation process may serve as novel therapeutic targets for CRC treatment. PMID:27829226

Head and neck mucosal melanoma: a review.

PubMed

Lourenço, Silvia V; Fernandes, Juliana D; Hsieh, Ricardo; Coutinho-Camillo, Claudia M; Bologna, Sheyla; Sangueza, Martin; Nico, Marcello M S

2014-07-01

Head and neck mucosal melanoma (MM) is an aggressive and rare neoplasm of melanocytic origin. To date, few retrospective series and case reports have been reported on MM. This article reviews the current evidence on head and neck MM and the molecular pathways that mediate the pathogenesis of this disease. Head and neck MM accounts for 0.7%-3.8% of all melanomas and involve (in decreasing order of frequency) the sinonasal cavity, oral cavity, pharynx, larynx, and upper esophagus. Although many studies have examined MM of the head and neck and the underlying molecular pathways, individual genetic and molecular alterations were less investigated. Further studies are needed to complement existing data and to increase our understanding of melanocytes tumorigenesis.

Lung cancer progression and metastasis from the prognostic point of view.

PubMed

Inamura, Kentaro; Ishikawa, Yuichi

2010-08-01

Lung cancer is the leading cause of cancer death in men and women worldwide. Since the occurrence of metastases in distant organs is the major reason for mortality of cancer patients, we need to elucidate the underlying mechanisms. Many studies featuring analysis of gene expression, comparative genomic hybridization and loss of heterozygosity analysis have been performed and generated support for the hypothesis that metastatic potential is acquired early in tumorigenesis. Furthermore, it is now clear that the majority of tumor cells have the potential to metastasize. Although many changes in gene expression profiles have been established retrospectively, translational research is now a high priority to enable clinical application and treatment based on laboratory findings.

The dose can make the poison: lessons learned from adverse in vivo toxicities caused by RNAi overexpression.

PubMed

Grimm, Dirk

2011-10-26

For the past five years, evidence has accumulated that vector-mediated robust RNA interference (RNAi) expression can trigger severe side effects in small and large animals, from cytotoxicity and accelerated tumorigenesis to organ failure and death. The recurring notions in these studies that a critical parameter is the strength of RNAi expression and that Exportin-5 and the Argonaute proteins are rate-limiting mammalian RNAi, strongly imply dose-dependent saturation of the endogenous miRNA pathway as one of the underlying mechanisms. This minireview summarizes the relevant work and data leading to this intriguing model and highlights potential avenues by which to alleviate RNAi-induced toxicities in future clinical applications.

Incubation and application of transgenic green fluorescent nude mice in visualization studies on glioma tissue remodeling.

PubMed

Dong, Jun; Dai, Xing-liang; Lu, Zhao-hui; Fei, Xi-feng; Chen, Hua; Zhang, Quan-bin; Zhao, Yao-dong; Wang, Zhi-min; Wang, Ai-dong; Lan, Qing; Huang, Qiang

2012-12-01

The primary reasons for local recurrence and therapeutic failure in the treatment of malignant gliomas are the invasion and interactions of tumor cells with surrounding normal brain cells. However, these tumor cells are hard to be visualized directly in histopathological preparations, or in experimental glioma models. Therefore, we developed an experimental human dual-color in vivo glioma model, which made tracking solitary invasive glioma cells possible, for the purpose of visualizing the interactions between red fluorescence labeled human glioma cells and host brain cells. This may offer references for further studying the roles of tumor microenvironment during glioma tissue remodeling. Transgenic female C57BL/6 mice expressing enhanced green fluorescent protein (EGFP) were crossed with male Balb/c nude mice. Then sib mating was allowed to occur continuously in order to establish an inbred nude mice strain with 50% of their offspring that are EGFP positive. Human glioma cell lines U87-MG and SU3 were transfected with red fluorescent protein (RFP) gene, and a rat C6 glioma cell line was stained directly with CM-DiI, to establish three glioma cell lines emitting red fluorescence (SU3-RFP, U87-RFP, and C6-CM-DiI). Red fluorescence tumor cells were inoculated via intra-cerebral injection into caudate nucleus of the EGFP nude mice. Tumor-bearing mice were sacrificed when their clinical symptoms appeared, and the whole brain was harvested and snap frozen for further analysis. Confocal laser scanning microscopy was performed to monitor the mutual interactions between tumor cells and host brain cells. Almost all the essential tissues of the established EGFP athymic Balb/c nude mice, except hair and erythrocytes, fluoresced green under excitation using a blue light-emitting flashlight with a central peak of 470 nm, approximately 50% of the offsprings were nu/nu EGFP+. SU3-RFP, U87-RFP, and C6-CM-DiI almost 100% expressed red fluorescence under the fluorescence microscope. Under fluorescence microscopic view, RFP+ cells were observed growing wherever they arrived at, locating in the brain parenchyma, ventricles, and para-vascular region. The interactions between the transplanted tumor cells and host adjacent cells could be classified into three types: (1) interweaving; (2) mergence; and (3) fusion. Interweaving was observed in the early stage of tumor remodeling, in which both transplantable tumor cells and host cells were observed scattered in the tumor invading and spreading area without organic connections. Mergence was defined as mutual interactions between tumor cells and host stroma during tumorigenesis. Direct cell fusion between transplantable tumor cells and host cells could be observed occasionally. This study showed that self-established EGFP athymic nude mice offered the possibility of visualizing tumorigenesis of human xenograft tumor, and the dual-color xenograft glioma model was of considerable utility in studying the process of tumor remodeling. Based on this platform, mutual interactions between glioma cells and host tissues could be observed directly to further elucidate the development of tumor microenvironment.

Proteomics analysis of altered proteins in kidney of mice with aristolochic acid nephropathy using the fluorogenic derivatization-liquid chromatography-tandem mass spectrometry method.

PubMed

Lin, Chia-En; Chang, Wen-Shin; Lee, Jen-Ai; Chang, Ting-Ya; Huang, Yu-Shen; Hirasaki, Yoshiro; Chen, Hung-Shing; Imai, Kazuhiro; Chen, Shih-Ming

2018-03-01

Aristolochic acid (AA) causes interstitial renal fibrosis, called aristolochic acid nephropathy (AAN). There is no specific indicator for diagnosing AAN, so this study aimed to investigate the biomarkers for AAN using a proteomics method. The C3H/He female mice were given ad libitum AA-distilled water (0.5 mg/kg/day) and distilled water for 56 days in the AA and normal groups, respectively. The AA-induced proteins in the kidney were investigated using a proteomics study, including fluorogenic derivatization with 7-chloro-N-[2-(dimethylamino)ethyl]-2,1,3-benzoxadiazole-4-sulfonamide, followed by high-performance liquid chromatography analysis and liquid chromatography tandem mass spectrometry with a MASCOT database searching system. There were two altered proteins, thrombospondin type 1 (TSP1) and G protein-coupled receptor 87 (GPR87), in the kidney of AA-group mice on day 56. GPR87, a tumorigenesis-related protein, is reported for the first time in the current study. The renal interstitial fibrosis was certainly induced in the AA-group mice under histological examination. Based on the results of histological examination and the proteomics study, this model might be applied to AAN studies in the future. TSP1 might be a novel biomarker for AAN, and the further role of GPR87 leading to AA-induced tumorigenesis should be researched in future studies. Copyright © 2017 John Wiley & Sons, Ltd.

Loss of DNA mismatch repair imparts a selective advantage in planarian adult stem cells.

PubMed

Hollenbach, Jessica P; Resch, Alissa M; Palakodeti, Dasaradhi; Graveley, Brenton R; Heinen, Christopher D

2011-01-01

Lynch syndrome (LS) leads to an increased risk of early-onset colorectal and other types of cancer and is caused by germline mutations in DNA mismatch repair (MMR) genes. Loss of MMR function results in a mutator phenotype that likely underlies its role in tumorigenesis. However, loss of MMR also results in the elimination of a DNA damage-induced checkpoint/apoptosis activation barrier that may allow damaged cells to grow unchecked. A fundamental question is whether loss of MMR provides pre-cancerous stem cells an immediate selective advantage in addition to establishing a mutator phenotype. To test this hypothesis in an in vivo system, we utilized the planarian Schmidtea mediterranea which contains a significant population of identifiable adult stem cells. We identified a planarian homolog of human MSH2, a MMR gene which is mutated in 38% of LS cases. The planarian Smed-msh2 is expressed in stem cells and some progeny. We depleted Smed-msh2 mRNA levels by RNA-interference and found a striking survival advantage in these animals treated with a cytotoxic DNA alkylating agent compared to control animals. We demonstrated that this tolerance to DNA damage is due to the survival of mitotically active, MMR-deficient stem cells. Our results suggest that loss of MMR provides an in vivo survival advantage to the stem cell population in the presence of DNA damage that may have implications for tumorigenesis.

Loss of DNA Mismatch Repair Imparts a Selective Advantage in Planarian Adult Stem Cells

PubMed Central

Hollenbach, Jessica P.; Resch, Alissa M.; Palakodeti, Dasaradhi; Graveley, Brenton R.; Heinen, Christopher D.

2011-01-01

Lynch syndrome (LS) leads to an increased risk of early-onset colorectal and other types of cancer and is caused by germline mutations in DNA mismatch repair (MMR) genes. Loss of MMR function results in a mutator phenotype that likely underlies its role in tumorigenesis. However, loss of MMR also results in the elimination of a DNA damage-induced checkpoint/apoptosis activation barrier that may allow damaged cells to grow unchecked. A fundamental question is whether loss of MMR provides pre-cancerous stem cells an immediate selective advantage in addition to establishing a mutator phenotype. To test this hypothesis in an in vivo system, we utilized the planarian Schmidtea mediterranea which contains a significant population of identifiable adult stem cells. We identified a planarian homolog of human MSH2, a MMR gene which is mutated in 38% of LS cases. The planarian Smed-msh2 is expressed in stem cells and some progeny. We depleted Smed-msh2 mRNA levels by RNA-interference and found a striking survival advantage in these animals treated with a cytotoxic DNA alkylating agent compared to control animals. We demonstrated that this tolerance to DNA damage is due to the survival of mitotically active, MMR-deficient stem cells. Our results suggest that loss of MMR provides an in vivo survival advantage to the stem cell population in the presence of DNA damage that may have implications for tumorigenesis. PMID:21747960

MicroRNA-300 targets hypoxia inducible factor-3 alpha to inhibit tumorigenesis of human non-small cell lung cancer.

PubMed

Zhang, Y; Guo, Y; Yang, C; Zhang, S; Zhu, X; Cao, L; Nie, W; Yu, H

2017-01-01

Non-small cell lung cancer (NSCLC) is one of the most deadly human cancers. MicroRNA-300 acts as both tumor promoter and suppressor in different types of cancer. Here, we try to identify the function of microRNA-300 in human NSCLC. We compared MicroRNA-300 levels between tumor tissues versus paired adjacent non-tumor lung tissues from NSCLC patients, and in NSCLC versus normal lung cell lines. Effects of microRNA-300 on cell proliferation, invasion and migration were examined in vitro, and on tumor growth in vivo using a xenograft mouse model. Potential mRNA targets of microRNA-300 were predicted and underlying mechanism was explored. MicroRNA-300 expression was lower in both NSCLC tissues and cell lines. Overexpression of microRNA-300 inhibited proliferation, invasion and migration of NSCLC cells in vitro, and tumor growth in vivo. MicroRNA-300 could directly bind to the 3'-UTR of hypoxia inducible factor-3 alpha (HIF3α) mRNA, and inhibit both its mRNA and protein expressions. Restoring HIF3α expression could rescue the inhibitory effects of microRNA-300 on tumorigenesis of NSCLC both in vitro and in vivo. MicroRNA-300 is a tumor suppressor microRNA in NSCLC by downregulating HIF3α expression. Both microRNA-300 and HIF3α may serve as potential therapeutic targets in NSCLC treatment.

Chemopreventive effects of standardized ethanol extract from the aerial parts of Artemisia princeps Pampanini cv. Sajabal via NF-κB inactivation on colitis-associated colon tumorigenesis in mice.

PubMed

Chung, Kyung-Sook; Choi, Hye-Eun; Shin, Ji-Sun; Cho, Eu-Jin; Cho, Young-Wuk; Choi, Jung-Hye; Baek, Nam-In; Lee, Kyung-Tae

2015-01-01

Chronic inflammation is an underlying risk factor of colon cancer, and NF-κB plays a critical role in the development of inflammation-associated colon cancer in an AOM/DSS mouse model. The aim of this study was to determine whether the standardized ethanol extract obtained from the aerial parts of Artemisia princeps Pampanini cv. Sajabal (EAPP) is effective at preventing inflammation-associated colon cancer, and if so, to identify the signaling pathways involved. In the present study, protective efficacy of EAPP on tumor formation and the infiltrations of monocytes and macrophages in colons of an AOM/DSS mouse model were evaluated. It was found that colitis and tumor burdens showed statistically meaningful improvements after EAPP administration. Furthermore, these improvements were accompanied by a reduction in NF-κB activity and in the levels of NF-κB-dependent pro-survival proteins, that is, survivin, cFLIP, XIAP, and Bcl-2. In vitro, EAPP significantly reduced NF-κB activation and the levels of IL-1β and IL-8 mRNA and pro-survival proteins in HT-29 and HCT-116 colon cancer cells. Furthermore, EAPP caused caspase-dependent apoptosis. Based on these results, the authors suggest EAPP suppresses inflammatory responses and induces apoptosis partly via NF-κB inactivation, and that EAPP could be useful for the prevention of colitis-associated tumorigenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

High Mitochondrial DNA Stability in B-Cell Chronic Lymphocytic Leukemia

PubMed Central

Cerezo, María; Bandelt, Hans-Jürgen; Martín-Guerrero, Idoia; Ardanaz, Maite; Vega, Ana; Carracedo, Ángel; García-Orad, África; Salas, Antonio

2009-01-01

Background Chronic Lymphocytic Leukemia (CLL) leads to progressive accumulation of lymphocytes in the blood, bone marrow, and lymphatic tissues. Previous findings have suggested that the mtDNA could play an important role in CLL. Methodology/Principal Findings The mitochondrial DNA (mtDNA) control-region was analyzed in lymphocyte cell DNA extracts and compared with their granulocyte counterpart extract of 146 patients suffering from B-Cell CLL; B-CLL (all recruited from the Basque country). Major efforts were undertaken to rule out methodological artefacts that would render a high false positive rate for mtDNA instabilities and thus lead to erroneous interpretation of sequence instabilities. Only twenty instabilities were finally confirmed, most of them affecting the homopolymeric stretch located in the second hypervariable segment (HVS-II) around position 310, which is well known to constitute an extreme mutational hotspot of length polymorphism, as these mutations are frequently observed in the general human population. A critical revision of the findings in previous studies indicates a lack of proper methodological standards, which eventually led to an overinterpretation of the role of the mtDNA in CLL tumorigenesis. Conclusions/Significance Our results suggest that mtDNA instability is not the primary causal factor in B-CLL. A secondary role of mtDNA mutations cannot be fully ruled out under the hypothesis that the progressive accumulation of mtDNA instabilities could finally contribute to the tumoral process. Recommendations are given that would help to minimize erroneous interpretation of sequencing results in mtDNA studies in tumorigenesis. PMID:19924307

Non-viral FoxM1 gene delivery to hepatocytes enhances liver repopulation

PubMed Central

Xiang, D; Liu, C-C; Wang, M-J; Li, J-X; Chen, F; Yao, H; Yu, B; Lu, L; Borjigin, U; Chen, Y-X; Zhong, L; Wangensteen, K J; He, Z-Y; Wang, X; Hu, Y-P

2014-01-01

Hepatocyte transplantation as a substitute strategy of orthotopic liver transplantation is being studied for treating end-stage liver diseases. Several technical hurdles must be overcome in order to achieve the therapeutic liver repopulation, such as the problem of insufficient expansion of the transplanted hepatocytes in recipient livers. In this study, we analyzed the application of FoxM1, a cell-cycle regulator, to enhance the proliferation capacity of hepatocytes. The non-viral sleeping beauty (SB) transposon vector carrying FoxM1 gene was constructed for delivering FoxM1 into the hepatocytes. The proliferation capacities of hepatocytes with FoxM1 expression were examined both in vivo and in vitro. Results indicated that the hepatocytes with FoxM1 expression had a higher proliferation rate than wild-type (WT) hepatocytes in vitro. In comparison with WT hepatocytes, the hepatocytes with FoxM1 expression had an enhanced level of liver repopulation in the recipient livers at both sub-acute injury (fumaryl acetoacetate hydrolase (Fah)–/– mice model) and acute injury (2/3 partial hepatectomy mice model). Importantly, there was no increased risk of tumorigenicity with FoxM1 expression in recipients even after serial transplantation. In conclusion, expression of FoxM1 in hepatocytes enhanced the capacity of liver repopulation without inducing tumorigenesis. FoxM1 gene delivered by non-viral SB vector into hepatocytes may be a viable approach to promote therapeutic repopulation after hepatocyte transplantation. PMID:24853430

Chemoprevention of skin cancer by grape constituent resveratrol: relevance to human disease?

PubMed

Aziz, Moammir Hasan; Reagan-Shaw, Shannon; Wu, Jianqiang; Longley, B Jack; Ahmad, Nihal

2005-07-01

According to the World Cancer Report, skin cancer constitutes approximately 30% of all newly diagnosed cancers in the world, and solar ultraviolet (UV) radiation (particularly, its UVB component; 290-320 nm) is an established cause of approximately 90% of skin cancers. The available options have proven to be inadequate for the management of skin cancers. Therefore, there is an urgent need to develop mechanism-based novel approaches for prevention/therapy of skin cancer. In this study, we evaluated the chemopreventive effects of resveratrol against UVB radiation-mediated skin tumorigenesis in the SKH-1 hairless mouse model. For our studies, we used a UVB initiation-promotion protocol in which the control mice were subjected to chronic UVB exposure (180 mJ/cm2, twice weekly, for 28 weeks). The experimental animals received either a pretreatment (30 min before each UVB) or post-treatment (5 min after UVB) of resveratrol (25 or 50 micro mole/0.2 ml acetone/mouse). The mice were followed for skin tumorigenesis and were killed at 24 h after the last UVB exposure, for further studies. The topical application of skin with resveratrol (both pre- and post- treatment) resulted in a highly significant 1) inhibition in tumor incidence, and 2) delay in the onset of tumorigenesis. Interestingly, the post-treatment of resveratrol was found to impart equal protection than the pretreatment; suggesting that resveratrol-mediated responses may not be sunscreen effects. Because Survivin is a critical regulator of survival/death of cells, and its overexpression has been implicated in several cancers, we evaluated its involvement in chemoprevention of UVB-mediated skin carcinogenesis by resveratrol. Our data demonstrated a significant 1) up-regulation of Survivin (both at protein- and mRNA- levels), 2) up-regulation of phospho-Survivin protein, and 3) down-regulation of proapoptotic Smac/DIABLO protein in skin tumors; whereas treatment with resveratrol resulted in the attenuation of these responses. Our study also suggests that resveratrol enhanced apoptosis in UVB-exposure-mediated skin tumors. Our study, for the first time, demonstrated that 1) resveratrol imparts strong chemopreventive effects against UVB exposure-mediated skin carcinogenesis (relevant to human skin cancers), and 2) the chemopreventive effects of resveratrol may, at least in part, be mediated via modulations in Survivin and other associated events. On the basis of our work, it is conceivable to design resveratrol-containing emollient or patch, as well as sunscreen and skin-care products for prevention of skin cancer and other conditions, which are believed to be caused by UV radiation.

SPIN1, negatively regulated by miR-148/152, enhances Adriamycin resistance via upregulating drug metabolizing enzymes and transporter in breast cancer.

PubMed

Chen, Xu; Wang, Ya-Wen; Gao, Peng

2018-05-09

Spindlin1 (SPIN1), a protein highly expressed in several human cancers, has been correlated with tumorigenesis and development. Alterations of drug metabolizing enzymes and drug transporters are major determinants of chemoresistance in tumor cells. However, whether the metabolizing enzymes and transporters are under the control of SPIN1 in breast cancer chemoresistance has not yet been defined. SPIN1 expression in breast cancer cells and tissues was detected by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. Chemosensitivity assays in vitro and in vivo were performed to determine the effect of SPIN1 on Adriamycin resistance. Downstream effectors of SPIN1 were screened by microarray and confirmed by qRT-PCR and Western blot. Luciferase assay and Western blot were used to identify miRNAs regulating SPIN1. We showed that SPIN1 was significantly elevated in drug-resistant breast cancer cell lines and tissues, compared with the chemosensitive ones. SPIN1 enhanced Adriamycin resistance of breast cancer cells in vitro, and downregulation of SPIN1 by miRNA could decrease Adriamycin resistance in vivo. Mechanistically, drug metabolizing enzymes and transporter CYP2C8, UGT2B4, UGT2B17 and ABCB4 were proven to be downstream effectors of SPIN1. Notably, SPIN1 was identified as a direct target of the miR-148/152 family (miR-148a-3p, miR-148b-3p and miR-152-3p). As expected, miR-148a-3p, miR-148b-3p or miR-152-3p could increase Adriamycin sensitivity in breast cancer cells in vitro. Moreover, high expression of SPIN1 or low expression of the miR-148/152 family predicted poorer survival in breast cancer patients. Our results establish that SPIN1, negatively regulated by the miR-148/152 family, enhances Adriamycin resistance in breast cancer via upregulating the expression of drug metabolizing enzymes and drug transporter.

Biomimetic Hydrogels Incorporating Polymeric Cell-Adhesive Peptide to Promote the 3D Assembly of Tumoroids

PubMed Central

Hao, Ying; Zerdoum, Aidan B.; Stuffer, Alexander J.; Rajasekaran, Ayyappan K.; Jia, Xinqiao

2016-01-01

Towards the goal of establishing physiologically relevant in vitro tumor models, we synthesized and characterized a biomimetic hydrogel using thiolated hyaluronic acid (HA-SH) and an acrylated copolymer carrying multiple copies of cell adhesive peptide (PolyRGD-AC). PolyRGD-AC was derived from a random copolymer of tert-butyl methacrylate (tBMA) and oligomeric (ethylene glycol) methacrylate (OEGMA), synthesized via atom transfer radical polymerization (ATRP). Acid hydrolysis of tert-butyl moieties revealed the carboxylates, through which acrylate groups were installed. Partial modification of the acrylate groups with a cysteine-containing RGD peptide generated PolyRGD-AC. When PolyRGD-AC was mixed with HA-SH under physiological conditions, a macroscopic hydrogel with an average elastic modulus of 630 Pa was produced. LNCaP prostate cancer cells encapsulated in HA-PolyRGD gels as dispersed single cells formed multicellular tumoroids by day 4 and reached an average diameter of ~95 μm by day 28. Cells in these structures were viable, formed cell-cell contacts through E-cadherin (E-CAD and displayed cortical organization of F-actin. Compared to the control gels prepared using PolyRDG, multivalent presentation of the RGD signal in the HA matrix increased cellular metabolism, promoted the development of larger tumoroids and enhanced the expression of E-CAD and integrins. Overall, hydrogels with multivalently immobilized RGD is a promising 3D culture platform for dissecting principles of tumorigenesis and for screening anticancer drugs. PMID:27723964

Drug development targeting the glycogen synthase kinase-3beta (GSK-3beta)-mediated signal transduction pathway: the role of GSK-3beta in the maintenance of steady-state levels of insulin receptor signaling molecules and Na(v)1.7 sodium channel in adrenal chromaffin cells.

PubMed

Nemoto, Takayuki; Yanagita, Toshihiko; Kanai, Tasuku; Wada, Akihiko

2009-02-01

Glycogen synthase kinase-3 (GSK-3) is constitutively active in nonstimulated cells, where the majority of its substrates undergo inactivation/proteolysis by phosphorylation. Extracellular stimuli (e.g., insulin) catalyze inhibitory Ser(9)-phosphorylation of GSK-3beta, turning on signaling and causing other biological consequences otherwise constitutively suppressed by GSK-3beta. Regulated and dysregulated activities of GSK-3beta are pivotal to health, disease, and therapeutics (e.g., insulin resistance, neurodegeneration, tumorigenesis, inflammation); however, the underlying mechanisms of multifunctional GSK-3beta remain elusive. In cultured bovine adrenal chromaffin cells, 1) constitutive and negatively-regulated activities of GSK-3beta up- and down-regulated insulin receptor, insulin receptor substrate-1 (IRS-1), IRS-2, and Akt levels via controlling proteasomal degradation and protein synthesis; 2) nicotinic receptor/protein kinase C-alpha (PKC-alpha)/extracellular signal-regulated kinase (ERK) pathway up-regulated IRS-1 and IRS-2 levels, enhancing insulin-induced the phosphoinositide 3-kinase (PI3K)/Akt/GSK-3beta pathway; 3) inhibition of calcineurin by cyclosporin A or FK506 down-regulated IRS-2 level, attenuating insulin-like growth factor-I (IGF-I)-induced ERK and GSK-3beta pathways; and 4) insulin, IGF-I or therapeutics (e.g., lithium) up-regulated the voltage-dependent Na(v)1.7 sodium channel.

The emerging roles of long non-coding RNA in gallbladder cancer tumorigenesis.

PubMed

Chen, Bing; Li, Ya; He, Yuting; Xue, Chen; Xu, Feng

2018-05-04

Accumulating evidence suggests that long non-coding RNAs (lncRNAs) have important regulatory functions in gallbladder cancer (GBC) tumorigenesis and can serve as potential novel markers and/or targets for GBC. In this review, we critically discuss the emerging alteration of lncRNAs in GBC, the lncRNAs induced epigenetic regulation, the interaction of lncRNAs with microRNAs and lncRNAs effects on tumor-related signaling pathways. Additionally, contributions of lncRNAs in epithelial-mesenchymal transition process and energy metabolism reprogramming in GBC are also addressed. This may pave new ways towards the determination of GBC pathogenesis and lead to the development of new preventive and therapeutic strategies for GBC.

Epigenetics in cancer stem cells.

PubMed

Toh, Tan Boon; Lim, Jhin Jieh; Chow, Edward Kai-Hua

2017-02-01

Compelling evidence have demonstrated that bulk tumors can arise from a unique subset of cells commonly termed "cancer stem cells" that has been proposed to be a strong driving force of tumorigenesis and a key mechanism of therapeutic resistance. Recent advances in epigenomics have illuminated key mechanisms by which epigenetic regulation contribute to cancer progression. In this review, we present a discussion of how deregulation of various epigenetic pathways can contribute to cancer initiation and tumorigenesis, particularly with respect to maintenance and survival of cancer stem cells. This information, together with several promising clinical and preclinical trials of epigenetic modulating drugs, offer new possibilities for targeting cancer stem cells as well as improving cancer therapy overall.

Genetics of pancreatic neuroendocrine tumors: implications for the clinic

PubMed Central

Pea, Antonio; Hruban, Ralph H.; Wood, Laura D.

2016-01-01

Pancreatic neuroendocrine tumors (PanNETs) are a common and deadly neoplasm of the pancreas. Although the importance of genetic alterations in PanNETs has been known for many years, recent comprehensive sequencing studies have greatly expanded our knowledge of neuroendocrine tumorigenesis in the pancreas. These studies have identified specific cellular processes that are altered in PanNETs, highlighted alterations with prognostic implications, and pointed to pathways for targeted therapies. In this review, we will discuss the genetic alterations that play a key role in PanNET tumorigenesis, with a specific focus on those alterations with the potential to change the way patients with these neoplasms are diagnosed and treated. PMID:26413978

Generation of SMURF2 knockout human cells using the CRISPR/Cas9 system.

PubMed

Manikoth Ayyathan, Dhanoop; Ilić, Nataša; Gil-Henn, Hava; Blank, Michael

2017-08-15

The HECT domain E3 ubiquitin ligase SMURF2 regulates stability of several key protein targets involved in tumorigenesis, cell proliferation, migration, differentiation, and senescence. While altered levels and aberrant cellular distribution of SMURF2 were reported in different types of cancer, its role in tumorigenesis is far from understood. To elucidate the role of SMURF2 in cancer, appropriate human cancer cell models are needed. Here, we describe approaches that can be used to generate human normal and cancer cell strains knocked-out for SMURF2 using the clustered regularly interspaced short palindromic repeats (CRISPR/Cas9) gene-editing technology. Copyright © 2017 Elsevier Inc. All rights reserved.

Long interspersed element-1 (LINE-1): passenger or driver in human neoplasms?

PubMed

Rodić, Nemanja; Burns, Kathleen H

2013-03-01

LINE-1 (L1) retrotransposons make up a significant portion of human genomes, with an estimated 500,000 copies per genome. Like other retrotransposons, L1 retrotransposons propagate through RNA sequences that are reverse transcribed into DNA sequences, which are integrated into new genomic loci. L1 somatic insertions have the potential to disrupt the transcriptome by inserting into or nearby genes. By mutating genes and playing a role in epigenetic dysregulation, L1 transposons may contribute to tumorigenesis. Studies of the "mobilome" have lagged behind other tumor characterizations at the sequence, transcript, and epigenetic levels. Here, we consider evidence that L1 retrotransposons may sometimes drive human tumorigenesis.

Hacking RNA: Hakai promotes tumorigenesis by switching on the RNA-binding function of PSF

PubMed Central

Figueroa, Angélica; Fujita, Yasuyuki; Gorospe, Myriam

2009-01-01

Hakai, an E3 ubiquitin ligase for the E-cadherin complex, plays a crucial role in lowering cell-cell contacts in epithelial cells, a hallmark feature of tumor progression. Recently, Hakai was also found to interact with PSF (PTB-associated splicing factor). While PSF can function as a DNA-binding protein with a tumor suppressive function, its association with Hakai promotes PSF’s RNA-binding ability and post-transcriptional influence on target mRNAs. Hakai overexpression enhanced the binding of PSF to mRNAs encoding cancer-related proteins, while knockdown of Hakai reduced the RNA-binding ability of PSF. Furthermore, the knockdown of PSF suppressed Hakai-induced cell proliferation. Thus, Hakai can affect the oncogenic phenotype both by altering E-cadherin-based intercellular adhesions and by increasing PSF’s ability to bind RNAs that promote cancer-related gene expression. PMID:19855157

Exosomes from Glioma-Associated Mesenchymal Stem Cells Increase the Tumorigenicity of Glioma Stem-like Cells via Transfer of miR-1587.

PubMed

Figueroa, Javier; Phillips, Lynette M; Shahar, Tal; Hossain, Anwar; Gumin, Joy; Kim, Hoon; Bean, Andrew J; Calin, George A; Fueyo, Juan; Walters, Edgar T; Kalluri, Raghu; Verhaak, Roel G; Lang, Frederick F

2017-11-01

Tumor-stromal communications impact tumorigenesis in ways that are incompletely understood. Here, we show that glioma-associated human mesenchymal stem cells (GA-hMSC), a newly identified stromal component of glioblastoma, release exosomes that increase the proliferation and clonogenicity of tumor-initiating glioma stem-like cells (GSC). This event leads to a significantly greater tumor burden and decreased host survival compared with untreated GSCs in orthotopic xenografts. Analysis of the exosomal content identified miR-1587 as a mediator of the exosomal effects on GSCs, in part via downregulation of the tumor-suppressive nuclear receptor corepressor NCOR1. Our results illuminate the tumor-supporting role for GA-hMSCs by identifying GA-hMSC-derived exosomes in the intercellular transfer of specific miRNA that enhance the aggressiveness of glioblastoma. Cancer Res; 77(21); 5808-19. ©2017 AACR . ©2017 American Association for Cancer Research.

Tumor growth affects the metabonomic phenotypes of multiple mouse non-involved organs in an A549 lung cancer xenograft model.

PubMed

Xu, Shan; Tian, Yuan; Hu, Yili; Zhang, Nijia; Hu, Sheng; Song, Dandan; Wu, Zhengshun; Wang, Yulan; Cui, Yanfang; Tang, Huiru

2016-06-22

The effects of tumorigenesis and tumor growth on the non-involved organs remain poorly understood although many research efforts have already been made for understanding the metabolic phenotypes of various tumors. To better the situation, we systematically analyzed the metabolic phenotypes of multiple non-involved mouse organ tissues (heart, liver, spleen, lung and kidney) in an A549 lung cancer xenograft model at two different tumor-growth stages using the NMR-based metabonomics approaches. We found that tumor growth caused significant metabonomic changes in multiple non-involved organ tissues involving numerous metabolic pathways, including glycolysis, TCA cycle and metabolisms of amino acids, fatty acids, choline and nucleic acids. Amongst these, the common effects are enhanced glycolysis and nucleoside/nucleotide metabolisms. These findings provided essential biochemistry information about the effects of tumor growth on the non-involved organs.

The Crosstalk of RAS with the TGF-β Family During Carcinoma Progression and its Implications for Targeted Cancer Therapy

PubMed Central

Grusch, M.; Petz, M.; Metzner, T.; Öztürk, D.; Schneller, D.; Mikulits, W.

2010-01-01

Both RAS and transforming growth factor (TGF)-β signaling cascades are central in tumorigenesis and show synergisms depending on tumor stage and tissue context. In this review we focus on the interaction of RAS subeffector proteins with signaling components of the TGF-β family including those of TGF-βs, activins and bone morphogenic proteins. Compelling evidence indicates that RAS signaling is essentially involved in the switch from tumor-suppressive to tumor-promoting functions of the TGF-β family leading to enhanced cancer growth and metastatic dissemination of primary tumors. Thus, the interface of these signaling cascades is considered as a promising target for the development of novel cancer therapeutics. The current pharmacological anti-cancer concepts combating the molecular cooperation between RAS and TGF-β family signaling during carcinoma progression are critically discussed. PMID:20718708

Aberrant expression of the PHF14 gene in biliary tract cancer cells

PubMed Central

AKAZAWA, TAKAKO; YASUI, KOHICHIROH; GEN, YASUYUKI; YAMADA, NOBUHISA; TOMIE, AKIRA; DOHI, OSAMU; MITSUYOSHI, HIRONORI; YAGI, NOBUAKI; ITOH, YOSHITO; NAITO, YUJI; YOSHIKAWA, TOSHIKAZU

2013-01-01

DNA copy number aberrations in human biliary tract cancer (BTC) cell lines were investigated using a high-density oligonucleotide microarray. A novel homozygous deletion was detected at chromosomal region 7p21.3 in the OZ cell line. Further validation experiments using genomic PCR revealed a homozygous deletion of a single gene, plant homeodomain (PHD) finger protein 14 (PHF14). No PHF14 mRNA or protein expression was detected, thus demonstrating the absence of PHF14 expression in the OZ cell line. Although the PHD finger protein is considered to be involved in chromatin-mediated transcriptional regulation, little is known about the function of PHF14 in cancer. The present study observed that the knock down of PHF14 using small interfering RNA (siRNA) enhanced the growth of the BTC cells. These observations suggest that aberrant PHF14 expression may have a role in the tumorigenesis of BTC. PMID:23833654

Down-regulation of 5S rRNA by miR-150 and miR-383 enhances c-Myc-rpL11 interaction and inhibits proliferation of esophageal squamous carcinoma cells.

PubMed

Wang, Xinyu; Ren, Yanli; Wang, Zhiqiong; Xiong, Xiangyu; Han, Sichong; Pan, Wenting; Chen, Hongwei; Zhou, Liqing; Zhou, Changchun; Yuan, Qipeng; Yang, Ming

2015-12-21

5S rRNA plays an important part in ribosome biology and is over-expression in multiple cancers. In this study, we found that 5S rRNA is a direct target of miR-150 and miR-383 in esophageal squamous cell carcinoma (ESCC). Overexpression of miR-150 and miR-383 inhibited ESCC cell proliferation in vitro and in vivo. Moreover, 5S rRNA silencing by miR-150 and miR-383 might intensify rpL11-c-Myc interaction, which attenuated role of c-Myc as an oncogenic transcriptional factor and dysregulation of multiple c-Myc target genes. Taken together, our results highlight the involvement of miRNAs in ribosomal regulation during tumorigenesis. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Amino acid catabolism: a pivotal regulator of innate and adaptive immunity

PubMed Central

McGaha, Tracy L.; Huang, Lei; Lemos, Henrique; Metz, Richard; Mautino, Mario; Prendergast, George C.; Mellor, Andrew L.

2014-01-01

Summary Enhanced amino acid catabolism is a common response to inflammation, but the immunologic significance of altered amino acid consumption remains unclear. The finding that tryptophan catabolism helped maintain fetal tolerance during pregnancy provided novel insights into the significance of amino acid metabolism in controlling immunity. Recent advances in identifying molecular pathways that enhance amino acid catabolism and downstream mechanisms that affect immune cells in response to inflammatory cues support the notion that amino acid catabolism regulates innate and adaptive immune cells in pathologic settings. Cells expressing enzymes that degrade amino acids modulate antigen-presenting cell and lymphocyte functions and reveal critical roles for amino acid- and catabolite-sensing pathways in controlling gene expression, functions, and survival of immune cells. Basal amino acid catabolism may contribute to immune homeostasis that prevents autoimmunity, whereas elevated amino acid catalytic activity may reinforce immune suppression to promote tumorigenesis and persistence of some pathogens that cause chronic infections. For these reasons, there is considerable interest in generating novel drugs that inhibit or induce amino acid consumption and target downstream molecular pathways that control immunity. In this review, we summarize recent developments and highlight novel concepts and key outstanding questions in this active research field. PMID:22889220

Gene amplification-associated overexpression of the RNA editing enzyme ADAR1 enhances human lung tumorigenesis.

PubMed

Anadón, C; Guil, S; Simó-Riudalbas, L; Moutinho, C; Setien, F; Martínez-Cardús, A; Moran, S; Villanueva, A; Calaf, M; Vidal, A; Lazo, P A; Zondervan, I; Savola, S; Kohno, T; Yokota, J; Ribas de Pouplana, L; Esteller, M

2016-08-18

The introduction of new therapies against particular genetic mutations in non-small-cell lung cancer is a promising avenue for improving patient survival, but the target population is small. There is a need to discover new potential actionable genetic lesions, to which end, non-conventional cancer pathways, such as RNA editing, are worth exploring. Herein we show that the adenosine-to-inosine editing enzyme ADAR1 undergoes gene amplification in non-small cancer cell lines and primary tumors in association with higher levels of the corresponding mRNA and protein. From a growth and invasion standpoint, the depletion of ADAR1 expression in amplified cells reduces their tumorigenic potential in cell culture and mouse models, whereas its overexpression has the opposite effects. From a functional perspective, ADAR1 overexpression enhances the editing frequencies of target transcripts such as NEIL1 and miR-381. In the clinical setting, patients with early-stage lung cancer, but harboring ADAR1 gene amplification, have poor outcomes. Overall, our results indicate a role for ADAR1 as a lung cancer oncogene undergoing gene amplification-associated activation that affects downstream RNA editing patterns and patient prognosis.

Repression of transcriptional activity of C/EBPalpha by E2F-dimerization partner complexes.

PubMed

Zaragoza, Katrin; Bégay, Valérie; Schuetz, Anja; Heinemann, Udo; Leutz, Achim

2010-05-01

The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPalpha) coordinates proliferation arrest and the differentiation of myeloid progenitors, adipocytes, hepatocytes, keratinocytes, and cells of the lung and placenta. C/EBPalpha transactivates lineage-specific differentiation genes and inhibits proliferation by repressing E2F-regulated genes. The myeloproliferative C/EBPalpha BRM2 mutant serves as a paradigm for recurrent human C-terminal bZIP C/EBPalpha mutations that are involved in acute myeloid leukemogenesis. BRM2 fails to repress E2F and to induce adipogenesis and granulopoiesis. The data presented here show that, independently of pocket proteins, C/EBPalpha interacts with the dimerization partner (DP) of E2F and that C/EBPalpha-E2F/DP interaction prevents both binding of C/EBPalpha to its cognate sites on DNA and transactivation of C/EBP target genes. The BRM2 mutant, in addition, exhibits enhanced interaction with E2F-DP and reduced affinity toward DNA and yet retains transactivation potential and differentiation competence that becomes exposed when E2F/DP levels are low. Our data suggest a tripartite balance between C/EBPalpha, E2F/DP, and pocket proteins in the control of proliferation, differentiation, and tumorigenesis.

E3 ubiquitin ligase Pirh2 enhances tumorigenic properties of human non-small cell lung carcinoma cells

PubMed Central

Fedorova, Olga; Shuvalov, Oleg; Merkulov, Valeriy; Vasileva, Elena; Antonov, Alexey; Barlev, Nikolai A.

2016-01-01

The product of RCHY1 human gene, Pirh2, is a RING-finger containing E3 ligase that modifies p53 with ubiquitin residues resulting in its subsequent degradation in proteasomes. Transcription of RCHY1 is regulated by p53 itself thus forming a negative regulatory feedback loop. Functionally, by eliminating p53, Pirh2 facilitates tumorigenesis. However, the role of Pirh2 in cancer cells lacking p53 is yet not well understood. Therefore, we decided to elucidate the role of Pirh2 in p53-negative human non-small cell lung carcinoma cells, H1299. We found that ectopic expression of Pirh2 enhanced cell proliferation, resistance to doxorubicin, and increased migration potential. Ablation of Pirh2 by specific shRNA reversed these phenotypes. Mechanistically, Pirh2 increased mRNA and protein levels of the c-Myc oncogene. The bioinformatics data indicate that co-expression of both c-Myc and Pirh2 strongly correlated with poor survival of lung cancer patients. Collectively, our results suggest that Pirh2 can be considered as a potential pharmacological target for developing anticancer therapies to treat p53-negative cancers. PMID:28191284

Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis.

PubMed

Nesnow, Stephen; Nelson, Garret; Padgett, William T; George, Michael H; Moore, Tanya; King, Leon C; Adams, Linda D; Ross, Jeffrey A

2010-07-30

Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-7,8-dihydroxy-7,8-dihydroB[a]P-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: (1) the induction of apurinic sites from radical cation processes, and (2) the metabolic formation of B[a]P-7,8-quinone (BPQ) that can form covalent DNA adducts or reactive oxygen species which can damage DNA. The studies presented here sought to examine the role of stable BPQ-DNA adducts in B[a]P-induced mouse lung tumorigenesis. Male strain A/J mice were injected intraperitoneally once with BPQ or trans-7,8-dihydroxy-7,8-dihydroB[a]P (BP-7,8-diol) at 30, 10, 3, or 0mg/kg. Lungs and livers were harvested after 24h, the DNA extracted and subjected to (32)P-postlabeling analysis. Additional groups of mice were dosed once with BPQ or BP-7,8-diol each at 30 mg/kg and tissues harvested 48 and 72 h later, or with B[a]P (50mg/kg, a tumorigenic dose) and tissues harvested 72 h later. No BPQ or any other DNA adducts were observed in lung or liver tissues 24, 48, or 72 h after the treatment with 30 mg/kg BPQ. BP-7,8-diol gave BPDE-DNA adducts at all time points in both tissues and B[a]P treatment gave BPDE-DNA adducts in the lung. In each case, no BPQ-DNA adducts were detected. Mouse body weights significantly decreased over time after BPQ or BP-7,8-diol treatments suggesting that systemic toxicity was induced by both agents. Model studies with BPQ and N-acetylcysteine suggested that BPQ is rapidly inactivated by sulfhydryl-containing compounds and not available for DNA adduction. We conclude that under these treatment conditions BPQ does not form stable covalent DNA adducts in the lungs or livers of strain A/J mice, suggesting that stable BPQ-covalent adducts are not a part of the complex of mechanisms involved in B[a]P-induced mouse lung tumorigenesis. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Circular RNA hsa_circ_0001982 Promotes Breast Cancer Cell Carcinogenesis Through Decreasing miR-143.

PubMed

Tang, Yi-Yin; Zhao, Ping; Zou, Tian-Ning; Duan, Jia-Jun; Zhi, Rong; Yang, Si-Yuan; Yang, De-Chun; Wang, Xiao-Li

2017-11-01

Circular RNAs (circRNAs) are a type of noncoding RNAs generated from back-splicing, which have been verified to mediate multiple tumorigenesis. With the development of high-throughput sequencing, massive circRNAs are discovered in tumorous tissue. However, the potential physiological effect of circRNAs in breast cancer is still unknown. The purpose of this study is to investigate the expression profile of circRNA in breast cancer tissue and explore the in-depth regulatory mechanism in breast cancer tumorigenesis. In the present study, we screened the circRNA expression profiles in breast cancer tissue using circRNA microarray analysis. Totally 1705 circRNAs were identified to be significantly aberrant. Among these dysregulated circRNAs, hsa_circ_0001982 was markedly overexpressed in breast cancer tissue and cell lines. Bioinformatics analysis predicted that miR-143 acted as target of hsa_circ_0001982, which was confirmed by Dual-luciferase reporter assay. Loss-of-function and rescue experiments revealed that hsa_circ_0001982 knockdown suppressed breast cancer cell proliferation and invasion and induced apoptosis by targeting miR-143. In summary, our study preliminarily investigates the circRNA expression in breast cancer tissue and explores the role of competing endogenous RNA (ceRNA) mechanism in the progression, providing a novel insight for breast cancer tumorigenesis.

Pokemon proto-oncogene in oral cancer: potential role in the early phase of tumorigenesis.

PubMed

Sartini, D; Lo Muzio, L; Morganti, S; Pozzi, V; Di Ruscio, G; Rocchetti, R; Rubini, C; Santarelli, A; Emanuelli, M

2015-05-01

Oral squamous cell carcinoma (OSCC) represents about 90% of all oral neoplasms with a poor clinical prognosis. To improve survival of OSCC patients, it is fundamental to understand the basic molecular mechanisms characterizing oral carcinogenesis. Dysregulation of oncogenes and tumor suppressor genes seems to play a central role in tumorigenesis, including malignant transformation of the oral cavity. We analyzed the expression levels of the pro-oncogenic transcription factor Pokemon through real-time PCR, Western blot and immunohistochemistry in tumor, and normal oral tissue samples obtained from 22 patients with OSCC. The relationship between tumor characteristics and the level of Pokemon intratumor expression was also analyzed. Pokemon was significantly downregulated in OSCC. In particular, both mRNA and protein levels (tumor vs normal tissue) inversely correlated with histological grading, suggesting its potential role as a prognostic factor for OSCC. Moreover, a significant inverse correlation was found between Pokemon protein expression levels (OSCC vs normal oral mucosa) and tumor size, supporting the hypothesis that Pokemon could play an important role in the early phase of tumor expansion. This work shows that reduced expression of Pokemon is a peculiar feature of OSCC. Additional studies may establish the effective role of Pokemon in oral tumorigenesis. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

miR-92a family and their target genes in tumorigenesis and metastasis

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

Li, Molin, E-mail: molin_li@hotmail.com; Institute of Cancer Stem Cell, Dalian Medical University Cancer Center, Dalian 116044; Guan, Xingfang

2014-04-15

The miR-92a family, including miR-25, miR-92a-1, miR-92a-2 and miR-363, arises from three different paralog clusters miR-17-92, miR-106a-363, and miR-106b-25 that are highly conservative in the process of evolution, and it was thought as a group of microRNAs (miRNAs) correlated with endothelial cells. Aberrant expression of miR-92a family was detected in multiple cancers, and the disturbance of miR-92a family was related with tumorigenesis and tumor development. In this review, the progress on the relationship between miR-92a family and their target genes and malignant tumors will be summarized. - Highlights: • Aberrant expression of miR-92a, miR-25 and miR-363 can be observed inmore » many kinds of malignant tumors. • The expression of miR-92a family is regulated by LOH, epigenetic alteration, transcriptional factors such as SP1, MYC, E2F, wild-type p53 etc. • Roles of miR-92a family in tumorigenesis and development: promoting cell proliferation, invasion and metastasis, inhibiting cell apoptosis.« less

The Immunomodulatory Capacity of an Epstein-Barr Virus Abortive Lytic Cycle: Potential Contribution to Viral Tumorigenesis

PubMed Central

2018-01-01

Epstein-Barr virus (EBV) is characterized by a bipartite life cycle in which latent and lytic stages are alternated. Latency is compatible with long-lasting persistency within the infected host, while lytic expression, preferentially found in oropharyngeal epithelial tissue, is thought to favor host-to-host viral dissemination. The clinical importance of EBV relates to its association with cancer, which we think is mainly a consequence of the latency/persistency mechanisms. However, studies in murine models of tumorigenesis/lymphomagenesis indicate that the lytic cycle also contributes to cancer formation. Indeed, EBV lytic expression is often observed in established cell lines and tumor biopsies. Within the lytic cycle EBV expresses a handful of immunomodulatory (BCRF1, BARF1, BNLF2A, BGLF5 & BILF1) and anti-apoptotic (BHRF1 & BALF1) proteins. In this review, we discuss the evidence supporting an abortive lytic cycle in which these lytic genes are expressed, and how the immunomodulatory mechanisms of EBV and related herpesviruses Kaposi Sarcoma herpesvirus (KSHV) and human cytomegalovirus (HCMV) result in paracrine signals that feed tumor cells. An abortive lytic cycle would reconcile the need of lytic expression for viral tumorigenesis without relaying in a complete cycle that would induce cell lysis to release the newly formed infective viral particles. PMID:29601503

Mediation of wound-related Rous sarcoma virus tumorigenesis by TFG (transforming growth factor)-. beta

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

Sieweke, M.H.; Bissell, M.J.; Thompson, N.L.

1990-06-29

In Rous sarcoma virus (RSV)-infected chickens, wounding leads to tumor formation with nearly 100% frequency in tissues that would otherwise remain tumor-free. Identifying molecular mediators of this phenomenon should yield important clues to the mechanisms involved in RSV tumorigenesis. Immunohistochemical staining showed that TGF-{beta} is present locally shortly after wounding, but not in unwounded controls. In addition, subcutaneous administration of recombinant transforming growth factor {beta}1 (TGF-{beta}1) could substitute completely for wounding in tumor induction. A treatment protocol of four doses of 800 nanograms of TGF-{beta} resulted in v-src-expressing tumors with 100% frequency; four doses of only 10 nanograms still ledmore » to tumor formation in 80% of the animals. This effect was specific, as other growth factors with suggested roles in would healing did not elicit the same response. Epidermal growth factor (EGF) or TGF-{alpha} had no effect, and platelet-derived growth factor (PDGF) or insulin-like growth factor-1 (IGF-1) yielded only occasional tumors after longer latency. TGF-{beta} release during the would-healing response may thus be a critical event that creates a conducive environment for RSV tumorigenesis and may act as a cofactor for transformation in this system. 31 refs., 3 figs., 2 tabs.« less

Chemoprevention of intestinal tumorigenesis by the natural dietary flavonoid myricetin in APCMin/+ mice

PubMed Central

Sun, Shi-Yue; Shi, Wen-Na; Song, Zhi-Yu; Wang, Shu-Qing; Yu, Xin-Feng; Gao, Zu-Hua; Qu, Xian-Jun

2016-01-01

Myricetin is a natural dietary flavonoid compound. We evaluated the efficacy of myricetin against intestinal tumorigenesis in adenomatous polyposis coli multiple intestinal neoplasia (APCMin/+) mice. Myricetin was given orally once a day for 12 consecutive weeks. APCMin/+ mice fed with myricetin developed fewer and smaller polyps without any adverse effects. Histopathological analysis showed a decreased number of dysplastic cells and degree of dysplasia in each polyp. Immunohistochemical and western blot analysis revealed that myricetin selectively inhibits cell proliferation and induces apoptosis in adenomatous polyps. The effects of myricetin were associated with a modulation the GSK-3β and Wnt/β-catenin pathways. ELISA analysis showed a reduced concentration of pro-inflammatory cytokines IL-6 and PGE2 in blood, which were elevated in APCMin/+ mice. The effect of myricetin treatment was more prominent in the adenomatous polyps originating in the colon. Further studies showed that myricetin downregulates the phosphorylated p38 MAPK/Akt/mTOR signaling pathways, which may be the mechanisms for the inhibition of adenomatous polyps by myricetin. Taken together, our data show that myricetin inhibits intestinal tumorigenesis through a collection of biological activities. Given these results, we suggest that myricetin could be used preventatively to reduce the risk of developing colon cancers. PMID:27507058

Chemoprevention of intestinal tumorigenesis by the natural dietary flavonoid myricetin in APCMin/+ mice.

PubMed

Li, Ye; Cui, Shu-Xiang; Sun, Shi-Yue; Shi, Wen-Na; Song, Zhi-Yu; Wang, Shu-Qing; Yu, Xin-Feng; Gao, Zu-Hua; Qu, Xian-Jun

2016-09-13

Myricetin is a natural dietary flavonoid compound. We evaluated the efficacy of myricetin against intestinal tumorigenesis in adenomatous polyposis coli multiple intestinal neoplasia (APCMin/+) mice. Myricetin was given orally once a day for 12 consecutive weeks. APCMin/+ mice fed with myricetin developed fewer and smaller polyps without any adverse effects. Histopathological analysis showed a decreased number of dysplastic cells and degree of dysplasia in each polyp. Immunohistochemical and western blot analysis revealed that myricetin selectively inhibits cell proliferation and induces apoptosis in adenomatous polyps. The effects of myricetin were associated with a modulation the GSK-3β and Wnt/β-catenin pathways. ELISA analysis showed a reduced concentration of pro-inflammatory cytokines IL-6 and PGE2 in blood, which were elevated in APCMin/+ mice. The effect of myricetin treatment was more prominent in the adenomatous polyps originating in the colon. Further studies showed that myricetin downregulates the phosphorylated p38 MAPK/Akt/mTOR signaling pathways, which may be the mechanisms for the inhibition of adenomatous polyps by myricetin. Taken together, our data show that myricetin inhibits intestinal tumorigenesis through a collection of biological activities. Given these results, we suggest that myricetin could be used preventatively to reduce the risk of developing colon cancers.

Role of Modulator of Inflammation Cyclooxygenase-2 in Gammaherpesvirus Mediated Tumorigenesis

PubMed Central

Gandhi, Jaya; Khera, Lohit; Gaur, Nivedita; Paul, Catherine; Kaul, Rajeev

2017-01-01

Chronic inflammation is recognized as a threat factor for cancer progression. Release of inflammatory molecules generates microenvironment which is highly favorable for development of tumor, cancer progression and metastasis. In cases of latent viral infections, generation of such a microenvironment is one of the major predisposing factors related to virus mediated tumorigenesis. Among various inflammatory mediators implicated in pathological process associated with cancer, the cyclooxygenase (COX) and its downstream effector molecules are of greater significance. Though the role of infectious agents in causing inflammation leading to transformation of cells has been more or less well established, however, the mechanism by which inflammation in itself modulates the events in life cycle of infectious agent is not very much clear. This is specifically important for gammaherpesviruses infections where viral life cycle is characterized by prolonged periods of latency when the virus remains hidden, immunologically undetectable and expresses only a very limited set of genes. Therefore, it is important to understand the mechanisms for role of inflammation in virus life cycle and tumorigenesis. This review is an attempt to summarize the latest findings highlighting the significance of COX-2 and its downstream signaling effectors role in life cycle events of gammaherpesviruses leading to progression of cancer. PMID:28400769

Meta-dimensional data integration identifies critical pathways for susceptibility, tumorigenesis and progression of endometrial cancer.

PubMed

Wei, Runmin; De Vivo, Immaculata; Huang, Sijia; Zhu, Xun; Risch, Harvey; Moore, Jason H; Yu, Herbert; Garmire, Lana X

2016-08-23

Endometrial Cancer (EC) is one of the most common female cancers. Genome-wide association studies (GWAS) have been investigated to identify genetic polymorphisms that are predictive of EC risks. Here we utilized a meta-dimensional integrative approach to seek genetically susceptible pathways that may be associated with tumorigenesis and progression of EC. We analyzed GWAS data obtained from Connecticut Endometrial Cancer Study (CECS) and identified the top 20 EC susceptible pathways. To further verify the significance of top 20 EC susceptible pathways, we conducted pathway-level multi-omics analyses using EC exome-Seq, RNA-Seq and survival data, all based on The Cancer Genome Atlas (TCGA) samples. We measured the overall consistent rankings of these pathways in all four data types. Some well-studied pathways, such as p53 signaling and cell cycle pathways, show consistently high rankings across different analyses. Additionally, other cell signaling pathways (e.g. IGF-1/mTOR, rac-1 and IL-5 pathway), genetic information processing pathway (e.g. homologous recombination) and metabolism pathway (e.g. sphingolipid metabolism) are also highly associated with EC risks, diagnosis and prognosis. In conclusion, the meta-dimensional integration of EC cohorts has suggested some common pathways that may be associated from predisposition, tumorigenesis to progression.

Tumor-associated myeloid cells promote tumorigenesis of non-tumorigenic human and murine prostatic epithelial cell lines.

PubMed

Sass, Stephanie N; Ramsey, Kimberley D; Egan, Shawn M; Wang, Jianmin; Cortes Gomez, Eduardo; Gollnick, Sandra O

2018-06-01

The etiology of prostate cancer is poorly understood, but it is a multi-step process that has been linked to environmental factors that induce inflammation within the gland. Glands of prostate cancer patients frequently contain multiple zones of disease at various stages of progression. The factors that drive disease progression from an indolent benign stage to aggressive disease are not well-defined. Prostate inflammation and carcinoma are associated with high levels of myeloid cell infiltration; these cells are linked to disease progression in other cancers, but their role in prostate cancer is unclear. To determine whether myeloid cells contribute to prostate cancer progression, the ability of prostate tumor-associated CD11b + cells (TAMC) to drive prostate epithelial cell tumorigenesis was tested. Co-culture of CD11b + TAMC with non-tumorigenic genetically primed prostate epithelial cells resulted in stable transformation and induction of tumorigenesis. RNA sequencing identified the IL-1α pathway as a potential molecular mechanism responsible for tumor promotion by TAMC. Inhibition of IL-1α delayed growth of TAMC-induced tumors. Further analysis showed that IL-1α inhibition led to decreased angiogenesis within tumors, suggesting that IL-1α promotes prostate tumor progression, potentially through augmentation of angiogenesis.

Estrogen and estrogen receptor alpha promotes malignancy and osteoblastic tumorigenesis in prostate cancer.

PubMed

Mishra, Sweta; Tai, Qin; Gu, Xiang; Schmitz, James; Poullard, Ashley; Fajardo, Roberto J; Mahalingam, Devalingam; Chen, Xiaodong; Zhu, Xueqiong; Sun, Lu-Zhe

2015-12-29

The role of estrogen signaling in regulating prostate tumorigenesis is relatively underexplored. Although, an increasing body of evidence has linked estrogen receptor beta (ERß) to prostate cancer, the function of estrogen receptor alpha (ERα) in prostate cancer is not very well studied. We have discovered a novel role of ERα in the pathogenesis of prostate tumors. Here, we show that prostate cancer cells express ERα and estrogen induces oncogenic properties in prostate cancer cells through ERα. Importantly, ERα knockdown in the human prostate cancer PacMetUT1 cells as well as pharmacological inhibition of ERα with ICI 182,780 inhibited osteoblastic lesion formation and lung metastasis in vivo. Co-culture of pre-osteoblasts with cancer cells showed a significant induction of osteogenic markers in the pre-osteoblasts, which was attenuated by knockdown of ERα in cancer cells suggesting that estrogen/ERα signaling promotes crosstalk between cancer and osteoblastic progenitors to stimulate osteoblastic tumorigenesis. These results suggest that ERα expression in prostate cancer cells is essential for osteoblastic lesion formation and lung metastasis. Thus, inhibition of ERα signaling in prostate cancer cells may be a novel therapeutic strategy to inhibit the osteoblastic lesion development as well as lung metastasis in patients with advanced prostate cancer.

Progression to Adrenocortical Tumorigenesis in Mice and Humans through Insulin-Like Growth Factor 2 and β-Catenin

PubMed Central

Heaton, Joanne H.; Wood, Michelle A.; Kim, Alex C.; Lima, Lorena O.; Barlaskar, Ferdous M.; Almeida, Madson Q.; Fragoso, Maria C.B.V.; Kuick, Rork; Lerario, Antonio M.; Simon, Derek P.; Soares, Ibere C.; Starnes, Elisabeth; Thomas, Dafydd G.; Latronico, Ana C.; Giordano, Thomas J.; Hammer, Gary D.

2013-01-01

Dysregulation of the WNT and insulin-like growth factor 2 (IGF2) signaling pathways has been implicated in sporadic and syndromic forms of adrenocortical carcinoma (ACC). Abnormal β-catenin staining and CTNNB1 mutations are reported to be common in both adrenocortical adenoma and ACC, whereas elevated IGF2 expression is associated primarily with ACC. To better understand the contribution of these pathways in the tumorigenesis of ACC, we examined clinicopathological and molecular data and used mouse models. Evaluation of adrenal tumors from 118 adult patients demonstrated an increase in CTNNB1 mutations and abnormal β-catenin accumulation in both adrenocortical adenoma and ACC. In ACC, these features were adversely associated with survival. Mice with stabilized β-catenin exhibited a temporal progression of increased adrenocortical hyperplasia, with subsequent microscopic and macroscopic adenoma formation. Elevated Igf2 expression alone did not cause hyperplasia. With the combination of stabilized β-catenin and elevated Igf2 expression, adrenal glands were larger, displayed earlier onset of hyperplasia, and developed more frequent macroscopic adenomas (as well as one carcinoma). Our results are consistent with a model in which dysregulation of one pathway may result in adrenal hyperplasia, but accumulation of a second or multiple alterations is necessary for tumorigenesis. PMID:22800756

Prx I Suppresses K-ras-Driven Lung Tumorigenesis by Opposing Redox-Sensitive ERK/Cyclin D1 Pathway

PubMed Central

Park, Young-Ho; Kim, Sun-Uk; Lee, Bo-Kyoung; Kim, Hyun-Sun; Song, In-Sung; Shin, Hye-Jun; Han, Ying-Hao; Chang, Kyu-Tae; Kim, Jin-Man; Lee, Dong-Seok; Kim, Yeul-Hong; Choi, Chang-Min; Kim, Bo-Yeon

2013-01-01

Abstract Aims: Coupled responses of mutated K-ras and oxidative stress are often an important etiological factor in non–small-cell lung cancer (NSCLC). However, relatively few studies have examined the control mechanism of oxidative stress in oncogenic K-ras-driven NSCLC progression. Here, we studied whether the redox signaling pathway governed by peroxiredoxin I (Prx I) is involved in K-rasG12D-mediated lung adenocarcinogenesis. Results: Using human-lung adenocarcinoma tissues and lung-specific K-rasG12D-transgenic mice, we found that Prx I was significantly up-regulated in the tumor regions via activation of nuclear erythroid 2-related factor 2 (Nrf2) transcription. Interestingly, the increased reactive oxygen species (ROS) by null mutation of Prx I greatly promoted K-rasG12D-driven lung tumorigenesis in number and size, which appeared to require the activation of the ROS-dependent extracellular signal-regulated kinase (ERK)/cyclin D1 pathway. Innovation: Taken together, these results suggest that Prx I functions as an Nrf2-dependently inducible tumor suppressant in K-ras-driven lung adenocarcinogenesis by opposing ROS/ERK/cyclin D1 pathway activation. Conclusion: These findings provide a better understanding of oxidative stress-mediated lung tumorigenesis. Antioxid. Redox Signal. 19, 482–496. PMID:23186333

Mice with Inactivation of Aryl Hydrocarbon Receptor-Interacting Protein (Aip) Display Complete Penetrance of Pituitary Adenomas with Aberrant ARNT Expression

PubMed Central

Raitila, Anniina; Lehtonen, Heli J.; Arola, Johanna; Heliövaara, Elina; Ahlsten, Manuel; Georgitsi, Marianthi; Jalanko, Anu; Paetau, Anders; Aaltonen, Lauri A.; Karhu, Auli

2010-01-01

Mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene have been shown to predispose to pituitary adenoma predisposition, a condition characterized by growth hormone (GH)-secreting pituitary tumors. To study AIP-mediated tumorigenesis, we generated an Aip mouse model. Heterozygous mice developed normally but were prone to pituitary adenomas, in particular to those secreting GH. A complete loss of AIP was detected in these lesions, and full penetrance was reached at the age of 15 months. No excess of any other tumor type was found. Ki-67 analysis indicated that Aip-deficient tumors have higher proliferation rates compared with Aip-proficient tumors, suggesting a more aggressive disease. Similar to human AIP-deficient pituitary adenomas, immunohistochemical studies showed that expression of aryl hydrocarbon receptor nuclear translocator 1 or 2 (ARNT or ARNT2) protein was lost in the mouse tumors, suggesting that mechanisms of AIP-related tumorigenesis involve aberrant ARNT function. The Aip+/− mouse appears to be an excellent model for the respective human disease phenotype. This model constitutes a tool to further study AIP-associated pituitary tumorigenesis and may be potentially valuable in efforts to develop therapeutic strategies to treat pituitary adenomas. PMID:20709796

Roles of Distal and Genic Methylation in the Development of Prostate Tumorigenesis Revealed by Genome-wide DNA Methylation Analysis.

PubMed

Wang, Yao; Jadhav, Rohit Ramakant; Liu, Joseph; Wilson, Desiree; Chen, Yidong; Thompson, Ian M; Troyer, Dean A; Hernandez, Javier; Shi, Huidong; Leach, Robin J; Huang, Tim H-M; Jin, Victor X

2016-02-29

Aberrant DNA methylation at promoters is often linked to tumorigenesis. But many aspects of DNA methylation remain unexplored, including the individual roles of distal and gene body methylation, as well as their collaborative roles with promoter methylation. Here we performed a MBD-seq analysis on prostate specimens classified into low, high, and very high risk group based on Gleason score and TNM stages. We identified gene sets with differential methylation regions (DMRs) in Distal, TSS, gene body and TES. To understand the collaborative roles, TSS was compared with the other three DMRs, resulted in 12 groups of genes with collaborative differential methylation patterns (CDMPs). We found several groups of genes that show opposite methylation patterns in Distal and Genic regions compared to TSS region, and in general they are differentially expressed genes (DEGs) in tumors in TCGA RNA-seq data. IPA (Ingenuity Pathway Analysis) reveals AR/TP53 signaling network to be a major signaling pathway, and survival analysis indicates genes subsets significantly associated with prostate cancer recurrence. Our results suggest that DNA methylation in Distal and Genic regions also plays critical roles in contributing to prostate tumorigenesis, and may act either positively or negatively with TSSs to alter gene regulation in tumors.

Effects of Two Traditional Chinese Cooking Oils, Canola and Pork, on pH and Cholic Acid Content of Faeces and Colon Tumorigenesis in Kunming Mice.

PubMed

He, Xiao-Qiong; Duan, Jia-Li; Zhou, Jin; Song, Zhong-Yu; Cichello, Simon Angelo

2015-01-01

Faecal pH and cholate are two important factors that can affect colon tumorigenesis, and can be modified by diet. In this study, the effects of two Chinese traditional cooking oils (pork oil and canola/rapeseed oil) on the pH and the cholic acid content in feces, in addition to colon tumorigenesis, were studied in mice. Kunming mice were randomized into various groups; negative control group (NCG), azoxymethane control group (ACG), pork oil group (POG), and canola oil Ggroup (COG). Mice in the ACG were fed a basic rodent chow; mice in POG and COG were given 10% cooking oil rodent chow with the respective oil type. All mice were given four weekly AOM (azoxymethane) i.p. injections (10 mg/kg). The pH and cholic acid of the feces were examined every two weeks. Colon tumors, aberrant crypt foci and organ weights were examined 32 weeks following the final AOM injection. The results showed that canola oil significantly decreased faecal pH in female mice (P<0.05), but had no influence on feces pH in male mice (P>0.05). Pork oil significantly increased the feces pH in both male and female mice (P<0.05). No significant change was found in feces cholic acid content when mice were fed 10% pork oil or canola oil compared with the ACG. Although Kunming mice were not susceptible to AOM-induced tumorigenesis in terms of colon tumor incidence, pork oil significantly increased the ACF number in male mice. Canola oil showed no influence on ACF in either male or female mice. Our results indicate that cooking oil effects faecal pH, but does not affect the faecal cholic acid content and thus AOM-induced colon neoplastic ACF is modified by dietary fat.

Deletion of p21/Cdkn1a confers protective effect against prostate tumorigenesis in transgenic adenocarcinoma of the mouse prostate model

PubMed Central

Jain, Anil K.; Raina, Komal; Agarwal, Rajesh

2013-01-01

Cyclin-dependent kinase inhibitors (CDKIs) p21Cip1/Waf1 (p21) and p27Kip1 (p27) play a determining role in cell cycle progression by regulating CDK activity; however, p21 role in prostate cancer (PCa) is controversial. Whereas p21 upregulation by anticancer agents causes cell cycle arrest in various PCa cell lines, elevated p21 levels have been associated with higher Gleason score, poor survival and increased PCa recurrence. These conflicting findings suggest that more studies are needed to examine p21 role in PCa. Herein, employing genetic approach, transgenic mice harboring p21/Cdkn1a homozygous deletion (p21−/−) were crossed with the transgenic adenocarcinoma of the mouse prostate (TRAMP) mice to characterize in vivo consequences of p21 deletion on prostate tumorigenesis. Lower urogenital tract weight of p21−/−/TRAMP mice was significantly lower than those of p21+/−/TRAMP and TRAMP mice. Histopathology further supported these observations, showing less aggressiveness in prostates of p21−/−/TRAMP. Furthermore, a significantly higher incidence of low-grade prostatic intraepithelial lesions (PIN) with a concomitant reduction in adenocarcinoma incidence was observed in p21−/−/TRAMP mice compared with TRAMP mice. In addition, whereas TRAMP mice showed the presence of poorly differentiated adenocarcinoma lesions, no such lesions were observed in p21/TRAMP transgenic mice. Specifically, there was a significant reduction in the severity of lesions in both p21−/−/TRAMP and p21+/−/TRAMP mice compared with TRAMP mice. Together, our data showed that p21 deletion reduces prostate tumorigenesis by slowing-down progression of PIN (pre-malignant) to adenocarcinoma (malignant), suggesting that intact p21 expression is associated with PCa aggressiveness, while its decreased levels may in fact confer protection against prostate tumorigenesis. PMID:23624841

The Transcriptional Coactivator TAZ Is a Potent Mediator of Alveolar Rhabdomyosarcoma Tumorigenesis.

PubMed

Deel, Michael D; Slemmons, Katherine K; Hinson, Ashley R; Genadry, Katia C; Burgess, Breanne A; Crose, Lisa E S; Kuprasertkul, Nina; Oristian, Kristianne M; Bentley, Rex C; Linardic, Corinne M

2018-03-07

Purpose: Alveolar rhabdomyosarcoma (aRMS) is a childhood soft tissue sarcoma driven by the signature PAX3-FOXO1 (P3F) fusion gene. Five-year survival for aRMS is <50%, with no improvement in over 4 decades. Although the transcriptional coactivator TAZ is oncogenic in carcinomas, the role of TAZ in sarcomas is poorly understood. The aim of this study was to investigate the role of TAZ in P3F-aRMS tumorigenesis. Experimental Design: After determining from publicly available datasets that TAZ is upregulated in human aRMS transcriptomes, we evaluated whether TAZ is also upregulated in our myoblast-based model of P3F-initiated tumorigenesis, and performed IHC staining of 63 human aRMS samples from tissue microarrays. Using constitutive and inducible RNAi, we examined the impact of TAZ loss of function on aRMS oncogenic phenotypes in vitro and tumorigenesis in vivo Finally, we performed pharmacologic studies in aRMS cell lines using porphyrin compounds, which interfere with TAZ-TEAD transcriptional activity. Results: TAZ is upregulated in our P3F-initiated aRMS model, and aRMS cells and tumors have high nuclear TAZ expression. In vitro , TAZ suppression inhibits aRMS cell proliferation, induces apoptosis, supports myogenic differentiation, and reduces aRMS cell stemness. TAZ-deficient aRMS cells are enriched in G 2 -M phase of the cell cycle. In vivo , TAZ suppression attenuates aRMS xenograft tumor growth. Preclinical studies show decreased aRMS xenograft tumor growth with porphyrin compounds alone and in combination with vincristine. Conclusions: TAZ is oncogenic in aRMS sarcomagenesis. While P3F is currently not therapeutically tractable, targeting TAZ could be a promising novel approach in aRMS. Clin Cancer Res; 1-15. ©2018 AACR. ©2018 American Association for Cancer Research.

The relevance of the vitamin D endocrine system (VDES) for tumorigenesis, prevention, and treatment of non-melanoma skin cancer (NMSC)

PubMed Central

Reichrath, Jörg; Reichrath, Sandra

2013-01-01

Solar UV (UV)-B-radiation exerts both beneficial and adverse effects on human health. On the one hand, it is the most important environmental risk factor for the development of non-melanoma skin cancer [NMSC; most importantly basal (BCC) and squamous (SCC) cell carcinomas], that represent the most common malignancies in Caucasian populations. On the other hand, the human body’s requirements of vitamin D are mainly achieved by UV-B-induced cutaneous photosynthesis. This dilemma represents a serious problem in many populations, for an association of vitamin D-deficiency and multiple independent diseases including various types of cancer has been convincingly demonstrated. In line with these findings, epidemiologic and laboratory investigations now indicate that vitamin D and its metabolites have a risk reducing effect for NMSC. Potential mechanisms of action include inhibition of the hedgehog signaling pathway (BCC) and modulation of p53-mediated DNA damage response (SCC). As a consequence of these new findings it can be concluded that UV-B-radiation exerts both beneficial and adverse effects on risk and prognosis of NMSC. It can be assumed that many independent factors, including frequency and dose of UV-B exposure, skin area exposed, and individual factors (such as skin type and genetic determinants of the skin`s vitamin D status and of signaling pathways that are involved in the tumorigenesis of NMSC) determine whether UV-B exposure promotes or inhibits tumorigenesis of NMSC. Moreover, these findings may help to explain many of the differential effects of UV-B radiation on risk of NMSC, including variation in the dose-dependent risk for development of SCC in situ (actinic keratosis, AK), invasive SCC, and BCC. In this review, we analyze the relevance of the vitamin D endocrine system (VDES) for tumorigenesis, prevention, and treatment of NMSC and give an overview of present concepts and future perspectives. PMID:24494041

DNA damage checkpoint recovery and cancer development

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

Wang, Haiyong; Zhang, Xiaoshan; Teng, Lisong, E-mail: lsteng@zju.edu.cn

2015-06-10

Cell cycle checkpoints were initially presumed to function as a regulator of cell cycle machinery in response to different genotoxic stresses, and later found to play an important role in the process of tumorigenesis by acting as a guard against DNA over-replication. As a counterpart of checkpoint activation, the checkpoint recovery machinery is working in opposition, aiming to reverse the checkpoint activation and resume the normal cell cycle. The DNA damage response (DDR) and oncogene induced senescence (OIS) are frequently found in precancerous lesions, and believed to constitute a barrier to tumorigenesis, however, the DDR and OIS have been observedmore » to be diminished in advanced cancers of most tissue origins. These findings suggest that when progressing from pre-neoplastic lesions to cancer, DNA damage checkpoint barriers are overridden. How the DDR checkpoint is bypassed in this process remains largely unknown. Activated cytokine and growth factor-signaling pathways were very recently shown to suppress the DDR and to promote uncontrolled cell proliferation in the context of oncovirus infection. In recent decades, data from cell line and tumor models showed that a group of checkpoint recovery proteins function in promoting tumor progression; data from patient samples also showed overexpression of checkpoint recovery proteins in human cancer tissues and a correlation with patients' poor prognosis. In this review, the known cell cycle checkpoint recovery proteins and their roles in DNA damage checkpoint recovery are reviewed, as well as their implications in cancer development. This review also provides insight into the mechanism by which the DDR suppresses oncogene-driven tumorigenesis and tumor progression. - Highlights: • DNA damage checkpoint works as a barrier to cancer initiation. • DDR machinary response to genotoxic and oncogenic stress in similar way. • Checkpoint recovery pathways provide active signaling in cell cycle control. • Checkpoint recovery pathway plays a role in overriding tumor barrier in tumorigenesis. • Recovery protein dysregulation and human cancer development is correlated.« less

Converting cancer genes into killer genes.

PubMed Central

Da Costa, L T; Jen, J; He, T C; Chan, T A; Kinzler, K W; Vogelstein, B

1996-01-01

Over the past decade, it has become clear that tumorigenesis is driven by alterations in genes that control cell growth or cell death. Theoretically, the proteins encoded by these genes provide excellent targets for new therapeutic agents. Here, we describe a gene therapy approach to specifically kill tumor cells expressing such oncoproteins. In outline, the target oncoprotein binds to exogenously introduced gene products, resulting in transcriptional activation of a toxic gene. As an example, we show that this approach can be used to specifically kill cells overexpressing a mutant p53 gene in cell culture. The strategy may be generally applicable to neoplastic diseases in which the underlying patterns of genetic alterations or abnormal gene expression are known. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5 PMID:8633039

Oxidized C5-methyl cytosine bases in DNA: 5-Hydroxymethylcytosine; 5-formylcytosine; and 5-carboxycytosine.

PubMed

Klungland, Arne; Robertson, Adam B

2017-06-01

Recent reports suggest that the Tet enzyme family catalytically oxidize 5-methylcytosine in mammalian cells. The oxidation of 5-methylcytosine can result in three chemically distinct species - 5-hydroxymethylcytsine, 5-formylcytosine, and 5-carboxycytosine. While the base excision repair machinery processes 5-formylcytosine and 5-carboxycytosine rapidly, 5-hydroxymethylcytosine is stable under physiological conditions. As a stable modification 5-hydroxymethylcytosine has a broad range of functions, from stem cell pluriopotency to tumorigenesis. The subsequent oxidation products, 5-formylcytosine and 5-carboxycytosine, are suggested to be involved in an active DNA demethylation pathway. This review provides an overview of the biochemistry and biology of 5-methylcytosine oxidation products. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

TNF-induced necroptosis requires the plasma membrane localization of the MLKL protein | Center for Cancer Research

Cancer.gov

The cell signaling protein tumor necrosis factor (TNF), produced by white blood cells, promotes inflammation and immunity processes such as fever and is involved in tumorigenesis and apoptosis (programmed cell death). However, dysregulation of TNF can also lead to another form of programmed cell death called necroptosis, which is characterized by a rise in intracellular Ca2+, generation of reactive oxygen species (ROS), intracellular acidity, depletion of ATP, and, eventually, plasma membrane rupture. TNF-induced necroptosis has been associated with a wide variety of diseases including neurodegenerative diseases, major depression, rheumatoid arthritis, and cancer. Whereas the signaling mechanisms underlying TNF-induced apoptosis have largely been determined, the events precipitating in TNF-initiated necroptosis are still unknown.

DNA replication stress and cancer chemotherapy.

PubMed

Kitao, Hiroyuki; Iimori, Makoto; Kataoka, Yuki; Wakasa, Takeshi; Tokunaga, Eriko; Saeki, Hiroshi; Oki, Eiji; Maehara, Yoshihiko

2018-02-01

DNA replication is one of the fundamental biological processes in which dysregulation can cause genome instability. This instability is one of the hallmarks of cancer and confers genetic diversity during tumorigenesis. Numerous experimental and clinical studies have indicated that most tumors have experienced and overcome the stresses caused by the perturbation of DNA replication, which is also referred to as DNA replication stress (DRS). When we consider therapeutic approaches for tumors, it is important to exploit the differences in DRS between tumor and normal cells. In this review, we introduce the current understanding of DRS in tumors and discuss the underlying mechanism of cancer therapy from the aspect of DRS. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.