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Sample records for oncogene proteins

  1. Intrinsic structural disorder confers cellular viability on oncogenic fusion proteins.

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    Hedi Hegyi

    2009-10-01

    Full Text Available Chromosomal translocations, which often generate chimeric proteins by fusing segments of two distinct genes, represent the single major genetic aberration leading to cancer. We suggest that the unifying theme of these events is a high level of intrinsic structural disorder, enabling fusion proteins to evade cellular surveillance mechanisms that eliminate misfolded proteins. Predictions in 406 translocation-related human proteins show that they are significantly enriched in disorder (43.3% vs. 20.7% in all human proteins, they have fewer Pfam domains, and their translocation breakpoints tend to avoid domain splitting. The vicinity of the breakpoint is significantly more disordered than the rest of these already highly disordered fusion proteins. In the unlikely event of domain splitting in fusion it usually spares much of the domain or splits at locations where the newly exposed hydrophobic surface area approximates that of an intact domain. The mechanisms of action of fusion proteins suggest that in most cases their structural disorder is also essential to the acquired oncogenic function, enabling the long-range structural communication of remote binding and/or catalytic elements. In this respect, there are three major mechanisms that contribute to generating an oncogenic signal: (i a phosphorylation site and a tyrosine-kinase domain are fused, and structural disorder of the intervening region enables intramolecular phosphorylation (e.g., BCR-ABL; (ii a dimerisation domain fuses with a tyrosine kinase domain and disorder enables the two subunits within the homodimer to engage in permanent intermolecular phosphorylations (e.g., TFG-ALK; (iii the fusion of a DNA-binding element to a transactivator domain results in an aberrant transcription factor that causes severe misregulation of transcription (e.g. EWS-ATF. Our findings also suggest novel strategies of intervention against the ensuing neoplastic transformations.

  2. SUMOylation Confers Posttranslational Stability on NPM-ALK Oncogenic Protein

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    Deeksha Vishwamitra

    2015-09-01

    Full Text Available Nucleophosmin-anaplastic lymphoma kinase–expressing (NPM-ALK+ T-cell lymphoma is an aggressive form of cancer that commonly affects children and adolescents. The expression of NPM-ALK chimeric oncogene results from the chromosomal translocation t(2;5(p23;q35 that causes the fusion of the ALK and NPM genes. This translocation generates the NPM-ALK protein tyrosine kinase that forms the constitutively activated NPM-ALK/NPM-ALK homodimers. In addition, NPM-ALK is structurally associated with wild-type NPM to form NPM/NPM-ALK heterodimers, which can translocate to the nucleus. The mechanisms that sustain the stability of NPM-ALK are not fully understood. SUMOylation is a posttranslational modification that is characterized by the reversible conjugation of small ubiquitin-like modifiers (SUMOs with target proteins. SUMO competes with ubiquitin for substrate binding and therefore, SUMOylation is believed to protect target proteins from proteasomal degradation. Moreover, SUMOylation contributes to the subcellular distribution of target proteins. Herein, we found that the SUMOylation pathway is deregulated in NPM-ALK+ T-cell lymphoma cell lines and primary lymphoma tumors from patients. We also identified Lys24 and Lys32 within the NPM domain as the sites where NPM-ALK conjugates with SUMO-1 and SUMO-3. Importantly, antagonizing SUMOylation by the SENP1 protease decreased the accumulation of NPM-ALK and suppressed lymphoma cell viability, proliferation, and anchorage-independent colony formation. One possible mechanism for the SENP1-mediated decrease in NPM-ALK levels was the increase in NPM-ALK association with ubiquitin, which facilitates its degradation. Our findings propose a model in which aberrancies in SUMOylation contribute to the pathogenesis of NPM-ALK+ T-cell lymphoma. Unraveling such pathogenic mechanisms may lead to devising novel strategies to eliminate this aggressive neoplasm.

  3. SUMOylation Confers Posttranslational Stability on NPM-ALK Oncogenic Protein.

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    Vishwamitra, Deeksha; Curry, Choladda V; Shi, Ping; Alkan, Serhan; Amin, Hesham M

    2015-09-01

    Nucleophosmin-anaplastic lymphoma kinase-expressing (NPM-ALK+) T-cell lymphoma is an aggressive form of cancer that commonly affects children and adolescents. The expression of NPM-ALK chimeric oncogene results from the chromosomal translocation t(2;5)(p23;q35) that causes the fusion of the ALK and NPM genes. This translocation generates the NPM-ALK protein tyrosine kinase that forms the constitutively activated NPM-ALK/NPM-ALK homodimers. In addition, NPM-ALK is structurally associated with wild-type NPM to form NPM/NPM-ALK heterodimers, which can translocate to the nucleus. The mechanisms that sustain the stability of NPM-ALK are not fully understood. SUMOylation is a posttranslational modification that is characterized by the reversible conjugation of small ubiquitin-like modifiers (SUMOs) with target proteins. SUMO competes with ubiquitin for substrate binding and therefore, SUMOylation is believed to protect target proteins from proteasomal degradation. Moreover, SUMOylation contributes to the subcellular distribution of target proteins. Herein, we found that the SUMOylation pathway is deregulated in NPM-ALK+ T-cell lymphoma cell lines and primary lymphoma tumors from patients. We also identified Lys24 and Lys32 within the NPM domain as the sites where NPM-ALK conjugates with SUMO-1 and SUMO-3. Importantly, antagonizing SUMOylation by the SENP1 protease decreased the accumulation of NPM-ALK and suppressed lymphoma cell viability, proliferation, and anchorage-independent colony formation. One possible mechanism for the SENP1-mediated decrease in NPM-ALK levels was the increase in NPM-ALK association with ubiquitin, which facilitates its degradation. Our findings propose a model in which aberrancies in SUMOylation contribute to the pathogenesis of NPM-ALK+ T-cell lymphoma. Unraveling such pathogenic mechanisms may lead to devising novel strategies to eliminate this aggressive neoplasm.

  4. Oncogenic ETS proteins mimic activated RAS/MAPK signaling in prostate cells

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    Hollenhorst, Peter C.; Ferris, Mary W.; Hull, Megan A.; Chae, Heejoon; Kim, Sun; Graves, Barbara J.

    2011-01-01

    The aberrant expression of an oncogenic ETS transcription factor is implicated in the progression of the majority of prostate cancers, 40% of melanomas, and most cases of gastrointestinal stromal tumor and Ewing's sarcoma. Chromosomal rearrangements in prostate cancer result in overexpression of any one of four ETS transcription factors. How these four oncogenic ETS genes differ from the numerous other ETS genes expressed in normal prostate and contribute to tumor progression is not understood. We report that these oncogenic ETS proteins, but not other ETS factors, enhance prostate cell migration. Genome-wide binding analysis matched this specific biological function to occupancy of a unique set of genomic sites highlighted by the presence of ETS- and AP-1-binding sequences. ETS/AP-1-binding sequences are prototypical RAS-responsive elements, but oncogenic ETS proteins activated a RAS/MAPK transcriptional program in the absence of MAPK activation. Thus, overexpression of oncogenic ETS proteins can replace RAS/MAPK pathway activation in prostate cells. The genomic description of this ETS/AP-1-regulated, RAS-responsive, gene expression program provides a resource for understanding the role of these ETS factors in both an oncogenic setting and the developmental processes where these genes normally function. PMID:22012618

  5. ERBB oncogene proteins as targets for monoclonal antibodies.

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    Polanovski, O L; Lebedenko, E N; Deyev, S M

    2012-03-01

    General properties of the family of tyrosine kinase ERBB receptors are considered in connection with their role in the generation of cascades of signal transduction in normal and tumor cells. Causes of acquisition of oncogene features by genes encoding these receptors and their role in tumorigenesis are analyzed. Anti-ERBB monoclonal antibodies approved for therapy are described in detail, and mechanisms of their antitumor activity and development of resistance to them are reviewed. The existing and the most promising strategies for creating and using monoclonal antibodies and their derivatives for therapy of cancer are discussed.

  6. Nuclear Localization and DNA Binding Properties of a Protein Expressed by Human c-myc Oncogene

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    Persson, Hakan; Leder, Philip

    1984-08-01

    Antisera to the human cellular myc oncogene product were used to identify a human c-myc specific protein with a molecular weight of 65,000. Subcellular fractionation showed that the human c-myc protein is predominantly found in the cell nucleus. The p65 Kc-myc protein binds to double- and single-stranded DNA as measured by a DNA affinity chromatography assay.

  7. Netrin-1 exerts oncogenic activities through enhancing Yes-associated protein stability.

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    Qi, Qi; Li, Dean Y; Luo, Hongbo R; Guan, Kun-Liang; Ye, Keqiang

    2015-06-09

    Yes-associated protein (YAP), a transcription coactivator, is the major downstream effector of the Hippo pathway, which plays a critical role in organ size control and cancer development. However, how YAP is regulated by extracellular stimuli in tumorigenesis remains incompletely understood. Netrin-1, a laminin-related secreted protein, displays proto-oncogenic activity in cancers. Nonetheless, the downstream signaling mediating its oncogenic effects is not well defined. Here we show that netrin-1 via its transmembrane receptors, deleted in colorectal cancer and uncoordinated-5 homolog, up-regulates YAP expression, escalating YAP levels in the nucleus and promoting cancer cell proliferation and migration. Inactivating netrin-1, deleted in colorectal cancer, or uncoordinated-5 homolog B (UNC5B) decreases YAP protein levels, abrogating cancer cell progression by netrin-1, whereas knockdown of mammalian STE20-like protein kinase 1/2 (MST1/2) or large tumor suppressor kinase 1/2 (Lats1/2), two sets of upstream core kinases of the Hippo pathway, has no effect in blocking netrin-1-induced up-regulation of YAP. Netrin-1 stimulates phosphatase 1A to dephosphorylate YAP, which leads to decreased ubiquitination and degradation, enhancing YAP accumulation and signaling. Hence, our findings support that netrin-1 exerts oncogenic activity through YAP signaling, providing a mechanism coupling extracellular signals to the nuclear YAP oncogene.

  8. Menin-MLL inhibitors reverse oncogenic activity of MLL fusion proteins in leukemia.

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    Grembecka, Jolanta; He, Shihan; Shi, Aibin; Purohit, Trupta; Muntean, Andrew G; Sorenson, Roderick J; Showalter, Hollis D; Murai, Marcelo J; Belcher, Amalia M; Hartley, Thomas; Hess, Jay L; Cierpicki, Tomasz

    2012-03-01

    Translocations involving the mixed lineage leukemia (MLL) gene result in human acute leukemias with very poor prognosis. The leukemogenic activity of MLL fusion proteins is critically dependent on their direct interaction with menin, a product of the multiple endocrine neoplasia (MEN1) gene. Here we present what are to our knowledge the first small-molecule inhibitors of the menin-MLL fusion protein interaction that specifically bind menin with nanomolar affinities. These compounds effectively reverse MLL fusion protein-mediated leukemic transformation by downregulating the expression of target genes required for MLL fusion protein oncogenic activity. They also selectively block proliferation and induce both apoptosis and differentiation of leukemia cells harboring MLL translocations. Identification of these compounds provides a new tool for better understanding MLL-mediated leukemogenesis and represents a new approach for studying the role of menin as an oncogenic cofactor of MLL fusion proteins. Our findings also highlight a new therapeutic strategy for aggressive leukemias with MLL rearrangements.

  9. Src-like-adaptor protein (SLAP) differentially regulates normal and oncogenic c-Kit signaling.

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    Kazi, Julhash U; Agarwal, Shruti; Sun, Jianmin; Bracco, Enrico; Rönnstrand, Lars

    2014-02-01

    The Src-like-adaptor protein (SLAP) is an adaptor protein sharing considerable structural homology with Src. SLAP is expressed in a variety of cells and regulates receptor tyrosine kinase signaling by direct association. In this report, we show that SLAP associates with both wild-type and oncogenic c-Kit (c-Kit-D816V). The association involves the SLAP SH2 domain and receptor phosphotyrosine residues different from those mediating Src interaction. Association of SLAP triggers c-Kit ubiquitylation which, in turn, is followed by receptor degradation. Although SLAP depletion potentiates c-Kit downstream signaling by stabilizing the receptor, it remains non-functional in c-Kit-D816V signaling. Ligand-stimulated c-Kit or c-Kit-D816V did not alter membrane localization of SLAP. Interestingly oncogenic c-Kit-D816V, but not wild-type c-Kit, phosphorylates SLAP on residues Y120, Y258 and Y273. Physical interaction between c-Kit-D816V and SLAP is mandatory for the phosphorylation to take place. Although tyrosine-phosphorylated SLAP does not affect c-Kit-D816V signaling, mutation of these tyrosine sites to phenylalanine can restore SLAP activity. Taken together the data demonstrate that SLAP negatively regulates wild-type c-Kit signaling, but not its oncogenic counterpart, indicating a possible mechanism by which the oncogenic c-Kit bypasses the normal cellular negative feedback control.

  10. The Oncogenic Palmitoyi-Protein Network in Prostate Cancer

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    2015-06-01

    obesity drug, Ortistat, which inhibits the enzyme fatty acid synthase (FASN), has been shown to slow the growth of human prostate tumors in mice...of PCa cells is significantly increased de novo synthesis of fatty acids and cholesterol, mainly caused by increased expression of fatty acid ...protein palmitoylation, a type of post-translational modification more accurately known as fatty S-acylation. In palmitoylation, long-chain fatty acids

  11. Oncogenic function and prognostic significance of protein tyrosine phosphatase PRL-1 in hepatocellular carcinoma.

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    Jin, Shaowen; Wang, Kaimei; Xu, Kang; Xu, Junyao; Sun, Jian; Chu, Zhonghua; Lin, Dechen; Koeffler, Phillip H; Wang, Jie; Yin, Dong

    2014-06-15

    Our SNP-Chip data demonstrated 7/60 (12%) hepatocellular carcinoma (HCC) patients had PRL-1 copy number amplification. However, its biological functions and signaling pathways in HCC are deficient. Here, we investigated its oncogenic function and prognostic significance in HCC. PRL-1 protein levels were examined in 167 HCC samples by immunohistochemisty (IHC). The relationship of PRL-1 expression and clinicopathological features was assessed by correlation, Kaplan-Meier and Cox regression analyses. The oncogenic function of PRL-1 in HCC cells and its underlying mechanism were investigated by ectopic overexpression and knockdown model. PRL-1 levels in primary HCC and metastatic intravascular cancer thrombus were also determined by IHC. PRL-1 levels were frequently elevated in HCC tissues (81%), and elevated expression of PRL-1 was significantly associated with more aggressive phenotype and poorer prognosis in HCC patients (pPRL-1 markedly enhanced HCC cells migration and invasion. Furthermore, the oncogenic functions of PRL-1 were mediated by PI3K/AKT/GSK3β signaling pathway through inhibiting E-cadherin expression. Finally, PRL-1 protein levels in metastatic cancer thrombus were higher than that in primary HCC tissues (pPRL-1 in HCC invasion and metastasis implicating PRL-1 as a potential prognostic marker as well as therapeutic target in HCC.

  12. An Interaction with Ewing's Sarcoma Breakpoint Protein EWS Defines a Specific Oncogenic Mechanism of ETS Factors Rearranged in Prostate Cancer.

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    Kedage, Vivekananda; Selvaraj, Nagarathinam; Nicholas, Taylor R; Budka, Justin A; Plotnik, Joshua P; Jerde, Travis J; Hollenhorst, Peter C

    2016-10-25

    More than 50% of prostate tumors have a chromosomal rearrangement resulting in aberrant expression of an oncogenic ETS family transcription factor. However, mechanisms that differentiate the function of oncogenic ETS factors expressed in prostate tumors from non-oncogenic ETS factors expressed in normal prostate are unknown. Here, we find that four oncogenic ETS (ERG, ETV1, ETV4, and ETV5), and no other ETS, interact with the Ewing's sarcoma breakpoint protein, EWS. This EWS interaction was necessary and sufficient for oncogenic ETS functions including gene activation, cell migration, clonogenic survival, and transformation. Significantly, the EWS interacting region of ERG has no homology with that of ETV1, ETV4, and ETV5. Therefore, this finding may explain how divergent ETS factors have a common oncogenic function. Strikingly, EWS is fused to various ETS factors by the chromosome translocations that cause Ewing's sarcoma. Therefore, these findings link oncogenic ETS function in both prostate cancer and Ewing's sarcoma. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  13. RNA-binding protein IGF2BP3 targeting of oncogenic transcripts promotes hematopoietic progenitor proliferation.

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    Palanichamy, Jayanth Kumar; Tran, Tiffany M; Howard, Jonathan M; Contreras, Jorge R; Fernando, Thilini R; Sterne-Weiler, Timothy; Katzman, Sol; Toloue, Masoud; Yan, Weihong; Basso, Giuseppe; Pigazzi, Martina; Sanford, Jeremy R; Rao, Dinesh S

    2016-04-01

    Posttranscriptional control of gene expression is important for defining both normal and pathological cellular phenotypes. In vitro, RNA-binding proteins (RBPs) have recently been shown to play important roles in posttranscriptional regulation; however, the contribution of RBPs to cell specification is not well understood. Here, we determined that the RBP insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) is specifically overexpressed in mixed lineage leukemia-rearranged (MLL-rearranged) B-acute lymphoblastic leukemia (B-ALL), which constitutes a subtype of this malignancy associated with poor prognosis and high risk of relapse. IGF2BP3 was required for the survival of B-ALL cell lines, as knockdown led to decreased proliferation and increased apoptosis. Enforced expression of IGF2BP3 provided murine BM cells with a strong survival advantage, led to proliferation of hematopoietic stem and progenitor cells, and skewed hematopoietic development to the B cell/myeloid lineage. Cross-link immunoprecipitation and high throughput sequencing uncovered the IGF2BP3-regulated transcriptome, which includes oncogenes MYC and CDK6 as direct targets. IGF2BP3 regulated transcripts via targeting elements within 3' untranslated regions (3'UTR), and enforced IGF2BP3 expression in mice resulted in enhanced expression of Myc and Cdk6 in BM. Together, our data suggest that IGF2BP3-mediated targeting of oncogenic transcripts may represent a critical pathogenetic mechanism in MLL-rearranged B-ALL and support IGF2BP3 and its cognate RNA-binding partners as potential therapeutic targets in this disease.

  14. The Oncogenic Properties Of The Redox Inflammatory Protein Inducible Nitric Oxide Synthase In ER(- Breast Cancer

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    David A. Wink

    2015-08-01

    Full Text Available Inflammation generates reactive chemical species that induce conditions of oxidative nitrosative stress as emerged as factor in poor outcome of many cancers. Our recent findings show that in the inflammatory protein inducible nitric oxide synthase (iNOS is a strong predictor of poor outcome in ER(- patients (Glynn et al. JCI 2010. Furthermore 46 genes, of which 23 were associated with basal like breast cancer, were elevated when iNOS high. In vitro studies using ER(- cell lines showed that fluxes of nitric oxide (NO delivered by NO donors surprising mimic this relationship in the patient cohort. Using this model, we show that NO at different specific concentrations stimulate pro-oncogenic mechanisms such as AKT, ERK, NFkB, AP-1, and HIF-1α that lead to increase of metastatic and cancer stem cells proteins. In addition, we show that tumor suppressor gene BRCA1 and PP2A are inhibited by these NO levels. Similarly other studies show that these concentrations of NO increase immunosuppressive proteins TGF-β and IL-10 in leukocytes to decrease efficacy of some anticancer therapies further contributing to pro-tumorigenic environment. Using this model we have identified several new compounds that have efficacy in xenographic models. These finding have provided a model that shows how NO can affect numerous mechanism that leads to a more aggressive phenotype.

  15. Characterization of the oncogenic function of centromere protein F in hepatocellular carcinoma

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    Dai, Yongdong; Liu, Lulu; Zeng, Tingting; Zhu, Ying-Hui [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Li, Jiangchao [Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou (China); Chen, Leilei [Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); Li, Yan; Yuan, Yun-Fei [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Ma, Stephanie, E-mail: stefma@hku.hk [Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong (China); Guan, Xin-Yuan, E-mail: xyguan@hkucc.hku.hk [State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou (China); Department of Clinical Oncology, The University of Hong Kong, Pokfulam, Hong Kong (China); State Key Laboratory for Liver Research, The University of Hong Kong, Pokfulam, Hong Kong (China)

    2013-07-12

    Highlights: •Overexpression of CENPF is frequently detected in HCC. •Upregulation of CENPF serves as an independent prognosis factor in HCC patients. •CENPF functions as an oncogene in HCC by promoting cell G2/M transition. -- Abstract: Centromere protein F (CENPF) is an essential nuclear protein associated with the centromere-kinetochore complex and plays a critical role in chromosome segregation during mitosis. Up-regulation of CENPF expression has previously been detected in several solid tumors. In this study, we aim to study the expression and functional role of CENPF in hepatocellular carcinoma (HCC). We found CENPF was frequently overexpressed in HCC as compared with non-tumor tissue. Up-regulated CENPF expression in HCC was positively correlated with serum AFP, venous invasion, advanced differentiation stage and a shorter overall survival. Cox regression analysis found that overexpression of CENPF was an independent prognosis factor in HCC. Functional studies found that silencing CENPF could decrease the ability of the cells to proliferate, form colonies and induce tumor formation in nude mice. Silencing CENPF also resulted in the cell cycle arrest at G2/M checkpoint by down-regulating cell cycle proteins cdc2 and cyclin B1. Our data suggest that CENPF is frequently overexpressed in HCC and plays a critical role in driving HCC tumorigenesis.

  16. A new generation of proto-oncogenes: cold-inducible RNA binding proteins.

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    Lleonart, M E

    2010-01-01

    This review focuses on the roles of two major cold-inducible RNA binding proteins known in human cells: CIRP and RBM3. Both proteins were discovered when they were shown to be induced after exposure to a moderate cold-shock and other cellular stresses such as UV radiation and hypoxia. Initially, it was suggested that these proteins have a suppressive rather stimulatory effect on proliferation; however, proliferative and/or proto-oncogenic functions have recently been assigned to CIRP and RBM3. In a high throughput genetic screen, we recently identified CIRP as an immortalized gene in murine primary cells. On the other hand, the role of RBM3 in transformation has already been demonstrated. Interestingly, both CIRP and RBM3 have been found to be up-regulated in human tumors. This article highlights the roles of CIRP and RBM3 in tumorigenesis, and proposes a model by which CIRP might contribute to senescence bypass by counteracting the deleterious effects of oxidative damage.

  17. Zinc finger protein 278, a potential oncogene in human colorectal cancer

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    Xiaoqing Tian; Danfeng Sun; Yanjie Zhang; Shuliang Zhao; Hua Xiong; Jingyuan Fang

    2008-01-01

    Zinc finger protein 278 (ZNF278) is a novel Krueppel Cys2-His2-type zinc finger protein that is ubiquitously distributed in human tissues. Whether ZNF278 is related to the development of colorectal cancer is still unclear. The transcriptional level of ZNF278 was studied in colorectal cancer by real-time polymerase chain reaction. The results showed that ZNF278 expression was increased in 53% of colorectal cancer tissues compared to corresponding non-cancerous tissues. The transcriptional down-regulation of ZNF278 was detected in only three (6%) human colorectal cancer tissues compared to corresponding non-cancer tissues. No significant difference was detected in 19 (41%) pairs of samples.However, we failed to find a significant association between the up-regulation of ZNF278 transcription and age, sex, the degree of infiltration, or the tumor size of colorectal cancer.To study the function of ZNF278 in colorectal carcinogenesis,the colon cancer cell line SW1116 was stably transfected with a wild-type ZNF278 plasmid to construct an overexpression system, and was transiently transfected with the small interfering RNA of ZNF278 to construct a ZNF278 knockdown system. Cell proliferation was assessed with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide dye and a cell counter. The results show that ZNF278 promotes cell growth, and its knockdown suppresses cell proliferation. ZNF278 could be a potential proto-oncogene in colorectal cancer.

  18. Constitutive Photomorphogensis Protein1 (COP1 mediated p53 pathway and its oncogenic role

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    Md. Golam Rabbani

    2014-05-01

    Full Text Available We have reviewed the COP1 mediated tumor suppressor protein p53 pathway and its oncogenic role. COP1 is a negative regulator of p53 and acts as a pivotal controller of p53-Akt death-live switch (Protein kinase B. In presence of p53, COP1 is overexpressed in breast, ovarian, gastric cancers, even without MDM2 (Mouse double minute-2 amplification. Following DNA damage, COP1 is phosphorylated instantly by ATM (Ataxia telangiectasia mutated and degraded by 14-3-3 and #963; following nuclear export and enhancing ubiquitination. In ATM lacking cell, other kinases, i.e. ATR (ataxia telangiectasia and Rad3-related protein, Jun kinases and DNA-PK (DNA-dependent protein kinase cause COP1 and CSN3 (COP9 signalosome complex subunit-3 phosphorylation and initiate COP1's down regulation. Although, it has been previously found that co-knockout of MDM2 and COP1 enhance p53's half life by eight fold, the reason is still unknown. Additionally, while interacting with p53, COP1 upregulate MDM2's E3 ubiquitin ligase, Akt, CSN6 (COP9 signalosome 6 activity and inhibit 14-3-3 and #963;'s negative regulation on MDM2 and COP1 itself. Conclusively, there persists an amplification loop among COP1, MDM2, Akt and 14-3-3 and #963; to regulate p53's stability and activity. However, the role of another tumor suppressor PTEN (phosphatase and tensin homologue is yet to be discovered. This study provides insight on the molecular genetic pathways related to cancer and might be helpful for therapeutic inventions. [Biomed Res Ther 2014; 1(5.000: 142-151

  19. Drosophila actin-Capping Protein limits JNK activation by the Src proto-oncogene.

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    Fernández, B G; Jezowska, B; Janody, F

    2014-04-17

    The Src family kinases c-Src, and its downstream effectors, the Rho family of small GTPases RhoA and Jun N-terminal kinase (JNK) have a significant role in tumorigenesis. In this report, using the Drosophila wing disc epithelium as a model system, we demonstrate that the actin-Capping Protein (CP) αβ heterodimer, which regulates actin filament (F-actin) polymerization, limits Src-induced apoptosis or tissue overgrowth by restricting JNK activation. We show that overexpressing Src64B drives JNK-independent loss of epithelial integrity and JNK-dependent apoptosis via Btk29A, p120ctn and Rho1. However, when cells are kept alive with the Caspase inhibitor P35, JNK acts as a potent inducer of proliferation via activation of the Yorkie oncogene. Reducing CP levels direct apoptosis of overgrowing Src64B-overexpressing tissues. Conversely, overexpressing capping protein inhibits Src64B and Rho1, but not Rac1-induced JNK signaling. CP requires the actin-binding domain of the α-subunit to limit Src64B-induced apoptosis, arguing that the control of F-actin mediates this effect. In turn, JNK directs F-actin accumulation. Moreover, overexpressing capping protein also prevents apoptosis induced by ectopic JNK expression. Our data are consistent with a model in which the control of F-actin by CP limits Src-induced apoptosis or tissue overgrowth by acting downstream of Btk29A, p120ctn and Rho1, but upstream of JNK. In turn, JNK may counteract the effect of CP on F-actin, providing a positive feedback, which amplifies JNK activation. We propose that cytoskeletal changes triggered by misregulation of F-actin modulators may have a significant role in Src-mediated malignant phenotypes during the early stages of cellular transformation.

  20. A RAS oncogene imparts growth factor independence to myeloid cells that abnormally regulate protein kinase C: a nonautocrine transformation pathway.

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    Boswell, H S; Nahreini, T S; Burgess, G S; Srivastava, A; Gabig, T G; Inhorn, L; Srour, E F; Harrington, M A

    1990-06-01

    The factor-dependent cell line FDC-P1 has been utilized as a model of interleukin 3 (IL-3)-dependent myeloid cell proliferation. However, it has been recently observed that active phorbol esters (e.g., phorbol 12-myristate 13-acetate) may entirely replace IL-3 to promote its proliferation. These observations reveal abnormal regulation of protein kinase C (pkC) (absence of downregulation or overexpression). This property allowed a test of the hypothesis that the T24 RAS (codon 12) oncogene acts by constitutive and persistent pkC activation, driving proliferation. FDC-P1 cells were transfected by electroporation with the T24 RAS-containing vector pAL 8, or with a control vector pSVX Zip Neo, and neomycin-resistant clones were selected. Multiple RAS-transfectant clones were categorized for their growth factor requirement and incorporation of the 6.6-kb human mutant H-RAS genome. IL-3-independent clones had incorporated multiple (more than two) copies of the entire 6.6-kb RAS genome. The incorporation of multiple 6.6-kb RAS genomes was correlated with high-level p21 RAS expression. No evidence for autostimulatory growth factor production by clones containing the RAS oncogene was observed. Thus, acquisition of growth factor independence in myeloid cells by abundant expression of a RAS oncogene is linked, in part, to abnormal regulation of pkC, which acts as a collaborating oncogene.

  1. Yes-associated protein (YAP modulates oncogenic features and radiation sensitivity in endometrial cancer.

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    Masahiro Tsujiura

    Full Text Available Yes-associated protein (YAP is a transcriptional co-activator and regulates cell proliferation and apoptosis. We investigated the clinical and biological significance of YAP in endometrial cancer (EMCA.YAP expression in 150 primary tumor tissues from patients with EMCA was evaluated by immunohistochemistry and its association with clinicopathological data was assessed. The biological functions of YAP were determined in EMCA cell lines through knockdown/overexpression of YAP. The role of YAP in modulating radiation sensitivity was also investigated in EMCA cells.Increased nuclear YAP expression was significantly associated with higher grade, stage, lympho-vascular space invasion, postoperative recurrence/metastasis and overall survival in estrogen mediated EMCA, called type 1 cancer (p = 0.019,  = 0.028,  = 0.0008,  = 0.046 and  = 0.015, respectively. In multivariate analysis, nuclear YAP expression was confirmed as an independent prognostic factor for overall survival in type 1 EMCA. YAP knockdown by siRNA resulted in a significant decrease in cell proliferation (p<0.05, anchorage-dependent growth (p = 0.015 and migration/invasion (p<0.05, and a significant increase in the number of cells in G0/G1 phase (p = 0.002. Conversely, YAP overexpression promoted cell proliferation. Clonogenic assay demonstrated enhanced radiosensitivity by approximately 36% in YAP inhibited cells.Since YAP functions as a transcriptional co-activator, its differential localization in the nucleus of cancer cells and subsequent impact on cell proliferation could have important consequences with respect to its role as an oncogene in EMCA. Nuclear YAP expression could be useful as a prognostic indicator or therapeutic target and predict radiation sensitivity in patients with EMCA.

  2. Oncogenic activation of the Met receptor tyrosine kinase fusion protein, Tpr-Met, involves exclusion from the endocytic degradative pathway.

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    Mak, H H L; Peschard, P; Lin, T; Naujokas, M A; Zuo, D; Park, M

    2007-11-01

    Multiple mechanisms of dysregulation of receptor tyrosine kinases (RTKs) are observed in human cancers. In addition to gain-of-function, loss of negative regulation also contributes to oncogenic activation of RTKs. Negative regulation of many RTKs involves their internalization and degradation in the lysosome, a process regulated through ubiquitination. RTK oncoproteins activated following chromosomal translocation, are no longer transmembrane proteins, and are predicted to escape lysosomal degradation. To test this, we used the Tpr-Met oncogene, generated following chromosomal translocation of the hepatocyte growth factor receptor (Met). Unlike Met, Tpr-Met is localized in the cytoplasm and also lacks the binding site for Cbl ubiquitin ligases. We determined whether subcellular localization of Tpr-Met, and/or loss of its Cbl-binding site, is important for oncogenic activity. Presence of a Cbl-binding site and ubiquitination of cytosolic Tpr-Met oncoproteins does not alter their transforming activity. In contrast, plasma membrane targeting allows Tpr-Met to enter the endocytic pathway, and Tpr-Met transforming activity as well as protein stability are decreased in a Cbl-dependent manner. We show that transformation by Tpr-Met is in part dependent on its ability to escape normal downregulatory mechanisms. This provides a paradigm for many RTK oncoproteins activated following chromosomal translocation.

  3. Analysis of origin and protein-protein interaction maps suggests distinct oncogenic role of nuclear EGFR during cancer evolution

    Science.gov (United States)

    Sharip, Ainur; Abdukhakimova, Diyora; Wang, Xiao; Kim, Alexey; Kim, Yevgeniy; Sharip, Aigul; Orakov, Askarbek; Miao, Lixia; Sun, Qinglei; Chen, Yue; Chen, Zhenbang; Xie, Yingqiu

    2017-01-01

    Receptor tyrosine kinase EGFR usually is localized on plasma membrane to induce progression of many cancers including cancers in children (Bodey et al. In Vivo. 2005, 19:931-41), but it contains a nuclear localization signal (NLS) that mediates EGFR nuclear translocation (Lin et al. Nat Cell Biol. 2001, 3:802-8). Here we report that NLS of EGFR has its old evolutionary origin. Protein-protein interaction maps suggests that nEGFR pathways are different from membrane EGFR and EGF is not found in nEGFR network while androgen receptor (AR) is found, which suggests the evolution of prostate cancer, a well-known AR driven cancer, through changes in androgen- or EGF-dependence. Database analysis suggests that nEGFR correlates with the tumor grades especially in prostate cancer patients. Structural predication analysis suggests that NLS can compromise the differential protein binding to EGFR through stretch linkers with evolutionary mutation from N to V. In experiment, elevation of nEGFR but not membrane EGFR was found in castration resistant prostate cancer cells. Finally, systems analysis of NLS and transmembrane domain (TM) suggests that NLS has old origin while NLS neighboring domain of TM has been undergone accelerated evolution. Thus nEGFR has an old origin resembling the cancer evolution but TM may interfere with NLS driven signaling for natural selection of survival to evade NLS induced aggressive cancers. Our data suggest NLS is a dynamic inducer of EGFR oncogenesis during evolution for advanced cancers. Our model provides novel insights into the evolutionary role of NLS of oncogenic kinases in cancers.

  4. Transcriptional regulation of oncogenic protein kinase Cϵ (PKCϵ) by STAT1 and Sp1 proteins.

    Science.gov (United States)

    Wang, HongBin; Gutierrez-Uzquiza, Alvaro; Garg, Rachana; Barrio-Real, Laura; Abera, Mahlet B; Lopez-Haber, Cynthia; Rosemblit, Cinthia; Lu, Huaisheng; Abba, Martin; Kazanietz, Marcelo G

    2014-07-11

    Overexpression of PKCϵ, a kinase associated with tumor aggressiveness and widely implicated in malignant transformation and metastasis, is a hallmark of multiple cancers, including mammary, prostate, and lung cancer. To characterize the mechanisms that control PKCϵ expression and its up-regulation in cancer, we cloned an ∼ 1.6-kb promoter segment of the human PKCϵ gene (PRKCE) that displays elevated transcriptional activity in cancer cells. A comprehensive deletional analysis established two regions rich in Sp1 and STAT1 sites located between -777 and -105 bp (region A) and -921 and -796 bp (region B), respectively, as responsible for the high transcriptional activity observed in cancer cells. A more detailed mutagenesis analysis followed by EMSA and ChIP identified Sp1 sites in positions -668/-659 and -269/-247 as well as STAT1 sites in positions -880/-869 and -793/-782 as the elements responsible for elevated promoter activity in breast cancer cells relative to normal mammary epithelial cells. RNAi silencing of Sp1 and STAT1 in breast cancer cells reduced PKCϵ mRNA and protein expression, as well as PRKCE promoter activity. Moreover, a strong correlation was found between PKCϵ and phospho-Ser-727 (active) STAT1 levels in breast cancer cells. Our results may have significant implications for the development of approaches to target PKCϵ and its effectors in cancer therapeutics.

  5. Rationally designed aberrant kinase-targeted endogenous protein nanomedicine against oncogene mutated/amplified refractory chronic myeloid leukemia.

    Science.gov (United States)

    Retnakumari, Archana P; Hanumanthu, Prasanna Lakshmi; Malarvizhi, Giridharan L; Prabhu, Raghuveer; Sidharthan, Neeraj; Thampi, Madhavan V; Menon, Deepthy; Mony, Ullas; Menon, Krishnakumar; Keechilat, Pavithran; Nair, Shantikumar; Koyakutty, Manzoor

    2012-11-05

    Deregulated protein kinases play a very critical role in tumorigenesis, metastasis, and drug resistance of cancer. Although molecularly targeted small molecule kinase inhibitors (SMI) are effective against many types of cancer, point mutations in the kinase domain impart drug resistance, a major challenge in the clinic. A classic example is chronic myeloid leukemia (CML) caused by BCR-ABL fusion protein, wherein a BCR-ABL kinase inhibitor, imatinib (IM), was highly successful in the early chronic phase of the disease, but failed in the advanced stages due to amplification of oncogene or point mutations in the drug-binding site of kinase domain. Here, by identifying critical molecular pathways responsible for the drug-resistance in refractory CML patient samples and a model cell line, we have rationally designed an endogenous protein nanomedicine targeted to both cell surface receptors and aberrantly activated secondary kinase in the oncogenic network. Molecular diagnosis revealed that, in addition to point mutations and amplification of oncogenic BCR-ABL kinase, relapsed/refractory patients exhibited significant activation of STAT5 signaling with correlative overexpression of transferrin receptors (TfR) on the cell membrane. Accordingly, we have developed a human serum albumin (HSA) based nanomedicine, loaded with STAT5 inhibitor (sorafenib), and surface conjugated the same with holo-transferrin (Tf) ligands for TfR specific delivery. This dual-targeted "transferrin conjugated albumin bound sorafenib" nanomedicine (Tf-nAlb-Soraf), prepared using aqueous nanoprecipitation method, displayed uniform spherical morphology with average size of ∼150 nm and drug encapsulation efficiency of ∼74%. TfR specific uptake and enhanced antileukemic activity of the nanomedicine was found maximum in the most drug resistant patient sample having the highest level of STAT5 and TfR expression, thereby confirming the accuracy of our rational design and potential of dual

  6. Kinase-dead ATM protein is highly oncogenic and can be preferentially targeted by Topo-isomerase I inhibitors.

    Science.gov (United States)

    Yamamoto, Kenta; Wang, Jiguang; Sprinzen, Lisa; Xu, Jun; Haddock, Christopher J; Li, Chen; Lee, Brian J; Loredan, Denis G; Jiang, Wenxia; Vindigni, Alessandro; Wang, Dong; Rabadan, Raul; Zha, Shan

    2016-06-15

    Missense mutations in ATM kinase, a master regulator of DNA damage responses, are found in many cancers, but their impact on ATM function and implications for cancer therapy are largely unknown. Here we report that 72% of cancer-associated ATM mutations are missense mutations that are enriched around the kinase domain. Expression of kinase-dead ATM (Atm(KD/-)) is more oncogenic than loss of ATM (Atm(-/-)) in mouse models, leading to earlier and more frequent lymphomas with Pten deletions. Kinase-dead ATM protein (Atm-KD), but not loss of ATM (Atm-null), prevents replication-dependent removal of Topo-isomerase I-DNA adducts at the step of strand cleavage, leading to severe genomic instability and hypersensitivity to Topo-isomerase I inhibitors. Correspondingly, Topo-isomerase I inhibitors effectively and preferentially eliminate Atm(KD/-), but not Atm-proficientor Atm(-/-) leukemia in animal models. These findings identify ATM kinase-domain missense mutations as a potent oncogenic event and a biomarker for Topo-isomerase I inhibitor based therapy.

  7. Protein tyrosine phosphatase receptor delta acts as a neuroblastoma tumor suppressor by destabilizing the aurora kinase a oncogene

    LENUS (Irish Health Repository)

    Meehan, Maria

    2012-02-05

    Abstract Background Protein tyrosine phosphatase receptor delta (PTPRD) is a member of a large family of protein tyrosine phosphatases which negatively regulate tyrosine phosphorylation. Neuroblastoma is a major childhood cancer arising from precursor cells of the sympathetic nervous system which is known to acquire deletions and alterations in the expression patterns of PTPRD, indicating a potential tumor suppressor function for this gene. The molecular mechanism, however, by which PTPRD renders a tumor suppressor effect in neuroblastoma is unknown. Results As a molecular mechanism, we demonstrate that PTPRD interacts with aurora kinase A (AURKA), an oncogenic protein that is over-expressed in multiple forms of cancer, including neuroblastoma. Ectopic up-regulation of PTPRD in neuroblastoma dephosphorylates tyrosine residues in AURKA resulting in a destabilization of this protein culminating in interfering with one of AURKA\\'s primary functions in neuroblastoma, the stabilization of MYCN protein, the gene of which is amplified in approximately 25 to 30% of high risk neuroblastoma. Conclusions PTPRD has a tumor suppressor function in neuroblastoma through AURKA dephosphorylation and destabilization and a downstream destabilization of MYCN protein, representing a novel mechanism for the function of PTPRD in neuroblastoma.

  8. Protein tyrosine phosphatase receptor delta acts as a neuroblastoma tumor suppressor by destabilizing the aurora kinase a oncogene

    Directory of Open Access Journals (Sweden)

    Meehan Maria

    2012-02-01

    Full Text Available Abstract Background Protein tyrosine phosphatase receptor delta (PTPRD is a member of a large family of protein tyrosine phosphatases which negatively regulate tyrosine phosphorylation. Neuroblastoma is a major childhood cancer arising from precursor cells of the sympathetic nervous system which is known to acquire deletions and alterations in the expression patterns of PTPRD, indicating a potential tumor suppressor function for this gene. The molecular mechanism, however, by which PTPRD renders a tumor suppressor effect in neuroblastoma is unknown. Results As a molecular mechanism, we demonstrate that PTPRD interacts with aurora kinase A (AURKA, an oncogenic protein that is over-expressed in multiple forms of cancer, including neuroblastoma. Ectopic up-regulation of PTPRD in neuroblastoma dephosphorylates tyrosine residues in AURKA resulting in a destabilization of this protein culminating in interfering with one of AURKA's primary functions in neuroblastoma, the stabilization of MYCN protein, the gene of which is amplified in approximately 25 to 30% of high risk neuroblastoma. Conclusions PTPRD has a tumor suppressor function in neuroblastoma through AURKA dephosphorylation and destabilization and a downstream destabilization of MYCN protein, representing a novel mechanism for the function of PTPRD in neuroblastoma.

  9. Genetic modelling of PIM proteins in cancer: proviral tagging, cooperation with oncogenes, tumor suppressor genes and carcinogens.

    Directory of Open Access Journals (Sweden)

    Enara eAguirre

    2014-05-01

    Full Text Available The PIM proteins, which were initially discovered as proviral insertion sites in Moloney murine leukemia virus infection, are a family of highly homologous serine/threonine kinases that have been reported to be overexpressed in hematological malignancies and solid tumors. The PIM proteins have also been associated with metastasis and overall treatment responses and implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anticancer drug discovery. The use of retroviral insertional mutagenesis and refined approaches such as complementation tagging has allowed the identification of myc, pim and a third group of genes (including bmi1 and gfi1 as complementing genes in lymphomagenesis. Moreover, mouse modeling of human cancer has provided an understanding of the molecular pathways that are involved in tumor initiation and progression at the physiological level. In particular, genetically modified mice have allowed researchers to further elucidate the role of each of the Pim isoforms in various tumor types. PIM kinases have been identified as weak oncogenes because experimental overexpression in lymphoid tissue, prostate and liver induces tumors at a relatively low incidence and with a long latency. However, very strong synergistic tumorigenicity between Pim1/2 and c-Myc and other oncogenes has been observed in lymphoid tissues. Mouse models have also been used to study whether the inhibition of specific PIM isoforms is required to prevent carcinogen-induced sarcomas, indicating that the absence of Pim2 and Pim3 greatly reduces sarcoma growth and bone invasion; the extent of this effect is similar to that observed in the absence of all 3 isoforms. This review will summarize some of the animal models that have been used to understand the isoform-specific contribution of PIM kinases to tumorigenesis.

  10. Oncogenic ALK regulates EMT in non-small cell lung carcinoma through repression of the epithelial splicing regulatory protein 1.

    Science.gov (United States)

    Voena, Claudia; Varesio, Lydia M; Zhang, Liye; Menotti, Matteo; Poggio, Teresa; Panizza, Elena; Wang, Qi; Minero, Valerio G; Fagoonee, Sharmila; Compagno, Mara; Altruda, Fiorella; Monti, Stefano; Chiarle, Roberto

    2016-05-31

    A subset of Non-Small Cell Lung Carcinoma (NSCLC) carries chromosomal rearrangements involving the Anaplastic Lymphoma Kinase (ALK) gene. ALK-rearranged NSCLC are typically adenocarcinoma characterized by a solid signet-ring cell pattern that is frequently associated with a metastatic phenotype. Recent reports linked the presence of ALK rearrangement to an epithelial-mesenchymal transition (EMT) phenotype in NSCLC, but the extent and the mechanisms of an ALK-mediated EMT in ALK-rearranged NSCLC are largely unknown. We found that the ALK-rearranged H2228 and DFCI032, but not the H3122, cell lines displayed a mesenchymal phenotype. In these cell lines, oncogenic ALK activity dictated an EMT phenotype by directly suppressing E-cadherin and up-regulating vimentin expression, as well as expression of other genes involved in EMT. We found that the epithelial splicing regulatory protein 1 (ESRP1), a key regulator of the splicing switch during EMT, was repressed by EML4-ALK activity. The treatment of NSCLC cells with ALK tyrosine kinase inhibitors (TKIs) led to up-regulation of ESRP1 and E-cadherin, thus reverting the phenotype from mesenchymal to epithelial (MET). Consistently, ESRP1 knock-down impaired E-cadherin up-regulation upon ALK inhibition, whereas enforced expression of ESRP1 was sufficient to increase E-cadherin expression. These findings demonstrate an ALK oncogenic activity in the regulation of an EMT phenotype in a subset of NSCLC with potential implications for the biology of ALK-rearranged NSCLC in terms of metastatic propensity and resistance to therapy.

  11. PTPN14 forms a complex with Kibra and LATS1 proteins and negatively regulates the YAP oncogenic function.

    Science.gov (United States)

    Wilson, Kayla E; Li, Ying-Wei; Yang, Nuo; Shen, He; Orillion, Ashley R; Zhang, Jianmin

    2014-08-22

    The Hippo signaling pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. Pivotal effectors of this pathway are YAP/TAZ, transcriptional co-activators whose dysfunction contributes to epithelial-to-mesenchymal transition and malignant transformation. Therefore, it is of great importance to decipher the mechanisms underlying the regulations of YAP/TAZ at various levels. Here we report that non-receptor tyrosine phosphatase 14 (PTPN14) interacts with the Kibra protein. The interaction between PTPN14 and Kibra is through the PPXY domain of PTPN14 and WW domain of Kibra. PTPN14 and Kibra can induce the LATS1 activation independently and cooperatively. Interestingly, activation of LATS1 by PTPN14 is dependent on the C terminus of PTPN14 and independent of the upstream mammalian STE20-like kinase (MST) proteins. Furthermore, we demonstrate that PTPN14 increases the LAST1 protein stability. Last, overexpression of Kibra rescues the increased cell migration and aberrant three-dimensional morphogenesis induced by knockdown of PTPN14, and this rescue is mediated through the activation of the upstream LATS1 kinase and subsequent cytoplasmic sequestration of YAP. In summary, our results indicate a potential regulatory role of PTPN14 in the Hippo pathway and demonstrate another layer of regulation in the YAP oncogenic function. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. Small molecule inhibition of protein depalmitoylation as a new approach towards downregulation of oncogenic Ras signalling

    NARCIS (Netherlands)

    Dekker, Frank J.; Hedberg, Christian

    2011-01-01

    The H- and N-Ras GTPases are prominent examples of proteins, whose localizations and signalling capacities are regulated by reversible palmitoylations and depalmitoylations. Recently, the novel small molecule inhibitor palmostatin B has been described to inhibit Ras depalmitoylation and to revert th

  13. The histone demethylase PHF8 is an oncogenic protein in human non-small cell lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yuzhou; Pan, Xufeng; Zhao, Heng, E-mail: hengzhao1966@sina.com

    2014-08-15

    Highlights: • PHF8 overexpresses in human NSCLC and predicts poor survival. • PHF8 regulates lung cancer cell growth and transformation. • PHF8 regulates apoptosis in human lung cancer cells. • PHF8 promotes miR-21 expression in human lung cancer. • MiR-21 is critically essential for PHF8 function in human lung cancer cells. - Abstract: PHF8 is a JmjC domain-containing protein and erases repressive histone marks including H4K20me1 and H3K9me1/2. It binds to H3K4me3, an active histone mark usually located at transcription start sites (TSSs), through its plant homeo-domain, and is thus recruited and enriched in gene promoters. PHF8 is involved in the development of several types of cancer, including leukemia, prostate cancer, and esophageal squamous cell carcinoma. Herein we report that PHF8 is an oncogenic protein in human non-small cell lung cancer (NSCLC). PHF8 is up-regulated in human NSCLC tissues, and high PHF8 expression predicts poor survival. Our in vitro and in vivo evidence demonstrate that PHF8 regulates lung cancer cell proliferation and cellular transformation. We found that PHF8 knockdown induces DNA damage and apoptosis in lung cancer cells. PHF8 promotes miR-21 expression in human lung cancer, and miR-21 knockdown blocks the effects of PHF8 on proliferation and apoptosis of lung cancer cells. In summary, PHF8 promotes lung cancer cell growth and survival by regulating miR-21.

  14. Screening for Novel Binding Proteins Interacting with Human Papillomavirus Type 18 E6 Oncogene in the Hela cDNA Library by Yeast Two-Hybrid System

    Institute of Scientific and Technical Information of China (English)

    Shuang LI; Ping LIU; Ling XI; Xuefeng JIANG; Jianfeng ZHOU; Shixuan WANG; Li MENG; Yunping LU; Ding Ma

    2008-01-01

    To screen for novel binding proteins interacting with high-risk HPV 18 E6 oncogene, the strain AH109 was transformed with pGBKT7-HPV18 E6 plasmid, and subsequent transference was utilized to screen for interacting proteins with HPV 18 E6 in human Hela cDNA library. HPVl8 E6 mRNA was expressed in yeast and there was no self-activation and toxicity in AH109. Seven proteins that interacted with HPV18 E6, including transmembrane protein 87B, phosphonoformate im- muno-associated protein 5, vimentin, KM-HN-1 protein, dedicator of cytokinesis 7, vaccinia related kinase 2 and a hypothetical protein, were identified. It was suggested that yeast two-hybrid system is an efficient for screening interacting proteins. The high-risk HPV 18 E6 oncogene may interact with the proteins, which may be associated with signal transduction and transeriptional control, epithelial cell invasion and migration, as well as humoral and cellular immune etc. This investigation provides functional clues for further exploration of potential oncogenesis targets for cancer biotherapy.

  15. Growth hormone induces expression of c-jun and jun B oncogenes and employs a protein kinase C signal transduction pathway for the induction of c-fos oncogene expression.

    Science.gov (United States)

    Slootweg, M C; de Groot, R P; Herrmann-Erlee, M P; Koornneef, I; Kruijer, W; Kramer, Y M

    1991-04-01

    Although the structure of several members of the GH receptor family has been defined, signal transduction following GH binding to its receptor has not been elucidated. Mouse osteoblasts were used to study the effect of GH on immediate early gene expression and, subsequently, the cellular signal(s) mediating this expression were analysed. GH rapidly and transiently induced the expression of c-jun and jun B in concert with the already reported expression of c-fos. The GH-induced expression of c-fos was completely blocked by the protein kinase inhibitors staurosporine and H7, indicating that the action of GH is mediated by one or several protein kinases. We next analysed the identity of the putative protein kinases in more detail by using a more specific protein kinase inhibitor, namely the ether-lipid 1-O-alkyl-2-O-methylglycerol, understood to be an inhibitor of protein kinase C (PKC). Data obtained from these studies revealed that GH-induced expression of c-fos is mediated by PKC. In addition, we observed a profound increase in formation of the PKC activator diacyglycerol upon addition of GH, a natural activator of PKC. In conclusion, upon binding of GH to mouse osteoblasts, the receptor-mediated cellular signal involves diacyglycerol formation and activation of PKC, leading to the induction of oncogene expression. Finally, the expression of c-fos, c-jun and jun B results in an increased binding of protein complexes to AP-1 binding sites.

  16. The protein encoded by the proto-oncogene DEK changes the topology of chromatin and reduces the efficiency of DNA replication in a chromatin-specific manner

    DEFF Research Database (Denmark)

    Alexiadis, V; Waldmann, T; Andersen, Jens S.

    2000-01-01

    The structure of chromatin regulates the genetic activity of the underlying DNA sequence. We report here that the protein encoded by the proto-oncogene DEK, which is involved in acute myelogenous leukemia, induces alterations of the superhelical density of DNA in chromatin. The change in topology...... is observed with chromatin but not with naked DNA and does not involve dissociation of core histones from chromatin. Moreover, these effects require histone H2A/H2B dimers in addition to histone H3/H4. We additionally tested whether the DEK protein affects DNA-utilizing processes and found that the DEK...

  17. Oncogenic fusion proteins expressed in immature hematopoietic cells fail to recapitulate the transcriptional changes observed in human AML

    DEFF Research Database (Denmark)

    Rapin, N; Porse, B T

    2014-01-01

    in acute promyelocytic leukemia. Hematopoietic stem/progenitor (HSPCs) cells transduced with oncogenic fusion genes are regarded as promising in vitromodels of their corresponding AML subtypes. Here, we critically assessed the potential of such in vitro models using an integrative bioinformatics approach...

  18. Conversion of the LIMA1 tumour suppressor into an oncogenic LMO-like protein by API2-MALT1 in MALT lymphoma.

    Science.gov (United States)

    Nie, Zilin; Du, Ming-Qing; McAllister-Lucas, Linda M; Lucas, Peter C; Bailey, Nathanael G; Hogaboam, Cory M; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2015-01-08

    MALT1 is the only known paracaspase and is a critical mediator of B- and T-cell receptor signalling. The function of the MALT1 gene is subverted by oncogenic chimeric fusions arising from the recurrent t(11;18)(q21;q21) aberration, which is the most frequent translocation in mucosa-associated lymphoid tissue (MALT) lymphoma. API2-MALT1-positive MALT lymphomas manifest antibiotic resistance and aggressive clinical behaviour with poor clinical outcome. However, the mechanisms underlying API2-MALT1-induced MALT lymphomagenesis are not fully understood. Here we show that API2-MALT1 induces paracaspase-mediated cleavage of the tumour suppressor protein LIMA1. LIMA1 binding by API2-MALT1 is API2 dependent and proteolytic cleavage is dependent on MALT1 paracaspase activity. Intriguingly, API2-MALT1-mediated proteolysis generates a LIM domain-only (LMO)-containing fragment with oncogenic properties in vitro and in vivo. Importantly, primary MALT lymphomas harbouring the API2-MALT1 fusion uniquely demonstrate LIMA1 cleavage fragments. Our studies reveal a novel paracaspase-mediated oncogenic gain-of-function mechanism in the pathogenesis of MALT lymphoma.

  19. The PDZ-binding motif of Yes-associated protein is required for its co-activation of TEAD-mediated CTGF transcription and oncogenic cell transforming activity.

    Science.gov (United States)

    Shimomura, Tadanori; Miyamura, Norio; Hata, Shoji; Miura, Ryota; Hirayama, Jun; Nishina, Hiroshi

    2014-01-17

    YAP is a transcriptional co-activator that acts downstream of the Hippo signaling pathway and regulates multiple cellular processes, including proliferation. Hippo pathway-dependent phosphorylation of YAP negatively regulates its function. Conversely, attenuation of Hippo-mediated phosphorylation of YAP increases its ability to stimulate proliferation and eventually induces oncogenic transformation. The C-terminus of YAP contains a highly conserved PDZ-binding motif that regulates YAP's functions in multiple ways. However, to date, the importance of the PDZ-binding motif to the oncogenic cell transforming activity of YAP has not been determined. In this study, we disrupted the PDZ-binding motif in the YAP (5SA) protein, in which the sites normally targeted by Hippo pathway-dependent phosphorylation are mutated. We found that loss of the PDZ-binding motif significantly inhibited the oncogenic transformation of cultured cells induced by YAP (5SA). In addition, the increased nuclear localization of YAP (5SA) and its enhanced activation of TEAD-dependent transcription of the cell proliferation gene CTGF were strongly reduced when the PDZ-binding motif was deleted. Similarly, in mouse liver, deletion of the PDZ-binding motif suppressed nuclear localization of YAP (5SA) and YAP (5SA)-induced CTGF expression. Taken together, our results indicate that the PDZ-binding motif of YAP is critical for YAP-mediated oncogenesis, and that this effect is mediated by YAP's co-activation of TEAD-mediated CTGF transcription.

  20. Both TEAD-binding and WW domains are required for the growth stimulation and oncogenic transformation activity of yes-associated protein.

    Science.gov (United States)

    Zhao, Bin; Kim, Joungmok; Ye, Xin; Lai, Zhi-Chun; Guan, Kun-Liang

    2009-02-01

    The Yes-associated protein (YAP) transcription coactivator is a candidate human oncogene and a key regulator of organ size. It is phosphorylated and inhibited by the Hippo tumor suppressor pathway. TEAD family transcription factors were recently shown to play a key role in mediating the biological functions of YAP. Here, we show that the WW domain of YAP has a critical role in inducing a subset of YAP target genes independent of or in cooperation with TEAD. Mutation of the WW domains diminishes the ability of YAP to stimulate cell proliferation and oncogenic transformation. Inhibition of YAP oncogenic-transforming activity depends on intact serine residues 127 and 381, two sites that could be phosphorylated by the Hippo pathway. Furthermore, genetic experiments in Drosophila support that WW domains of YAP and Yki, the fly YAP homologue, have an important role in stimulating tissue growth. Our data suggest a model in which YAP induces gene expression and exerts its biological functions by interacting with transcription factors through both the TEAD-binding and WW domains.

  1. The PDZ-binding motif of Yes-associated protein is required for its co-activation of TEAD-mediated CTGF transcription and oncogenic cell transforming activity

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, Tadanori; Miyamura, Norio; Hata, Shoji; Miura, Ryota; Hirayama, Jun, E-mail: hirayama.dbio@mri.tmd.ac.jp; Nishina, Hiroshi, E-mail: nishina.dbio@mri.tmd.ac.jp

    2014-01-17

    Highlights: •Loss of the PDZ-binding motif inhibits constitutively active YAP (5SA)-induced oncogenic cell transformation. •The PDZ-binding motif of YAP promotes its nuclear localization in cultured cells and mouse liver. •Loss of the PDZ-binding motif inhibits YAP (5SA)-induced CTGF transcription in cultured cells and mouse liver. -- Abstract: YAP is a transcriptional co-activator that acts downstream of the Hippo signaling pathway and regulates multiple cellular processes, including proliferation. Hippo pathway-dependent phosphorylation of YAP negatively regulates its function. Conversely, attenuation of Hippo-mediated phosphorylation of YAP increases its ability to stimulate proliferation and eventually induces oncogenic transformation. The C-terminus of YAP contains a highly conserved PDZ-binding motif that regulates YAP’s functions in multiple ways. However, to date, the importance of the PDZ-binding motif to the oncogenic cell transforming activity of YAP has not been determined. In this study, we disrupted the PDZ-binding motif in the YAP (5SA) protein, in which the sites normally targeted by Hippo pathway-dependent phosphorylation are mutated. We found that loss of the PDZ-binding motif significantly inhibited the oncogenic transformation of cultured cells induced by YAP (5SA). In addition, the increased nuclear localization of YAP (5SA) and its enhanced activation of TEAD-dependent transcription of the cell proliferation gene CTGF were strongly reduced when the PDZ-binding motif was deleted. Similarly, in mouse liver, deletion of the PDZ-binding motif suppressed nuclear localization of YAP (5SA) and YAP (5SA)-induced CTGF expression. Taken together, our results indicate that the PDZ-binding motif of YAP is critical for YAP-mediated oncogenesis, and that this effect is mediated by YAP’s co-activation of TEAD-mediated CTGF transcription.

  2. THE CANNABINOID WIN 55,212-2 DECREASES SPECIFICITY PROTEIN (Sp) TRANSCRIPTION FACTORS AND THE ONCOGENIC CAP PROTEIN eIF4E IN COLON CANCER CELLS

    Science.gov (United States)

    Sreevalsan, Sandeep; Safe, Stephen

    2013-01-01

    2,3-Dihydro-5-methyl-3-([morpholinyl]methyl)pyrollo(1,2,3-de)-1,4-benzoxazinyl]-[1-naphthaleny]methanone [WIN 55,212-2 (WIN)] is a synthetic cannabinoid that inhibits RKO, HT-29 and SW480 cell growth, induced apoptosis, and downregulated expression of survivin, cyclin D1, epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and its receptor (VEGFR1). WIN also decreased expression of specificity protein (Sp) transcription factors Sp1, Sp3 and Sp4, and this is consistent with the observed downregulation of the aforementioned Sp-regulated genes. In addition, we also observed by RNA interference (RNAi) that the oncogenic cap protein eIF4E was an Sp-regulated gene also downregulated by WIN in colon cancer cells. WIN-mediated repression of Sp proteins was not affected by CB receptor antagonists or by knockdown of the receptor but was attenuated by the phosphatase inhibitor sodium orthovanadate or by knockdown of protein phosphatase 2A (PP2A). WIN-mediated repression of Sp1, Sp3 and Sp4 was due to PP2A-dependent downregulation of microRNA-27a (miR-27a) and induction of miR-27a-regulated ZBTB10 which has previously been characterized as an “Sp repressor”. The results demonstrate that the anticancer activity of WIN is due, in part, to PP2A-dependent disruption of miR-27a:ZBTB10 and ZBTB10-mediated repression of Sp transcription factors and Sp-regulated genes including eIF4E. PMID:24030632

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

    Science.gov (United States)

    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.

  4. Blockade of oncogenic IκB kinase activity in diffuse large B-cell lymphoma by bromodomain and extraterminal domain protein inhibitors.

    Science.gov (United States)

    Ceribelli, Michele; Kelly, Priscilla N; Shaffer, Arthur L; Wright, George W; Xiao, Wenming; Yang, Yibin; Mathews Griner, Lesley A; Guha, Rajarshi; Shinn, Paul; Keller, Jonathan M; Liu, Dongbo; Patel, Paresma R; Ferrer, Marc; Joshi, Shivangi; Nerle, Sujata; Sandy, Peter; Normant, Emmanuel; Thomas, Craig J; Staudt, Louis M

    2014-08-01

    In the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), NF-κB activity is essential for viability of the malignant cells and is sustained by constitutive activity of IκB kinase (IKK) in the cytoplasm. Here, we report an unexpected role for the bromodomain and extraterminal domain (BET) proteins BRD2 and BRD4 in maintaining oncogenic IKK activity in ABC DLBCL. IKK activity was reduced by small molecules targeting BET proteins as well as by genetic knockdown of BRD2 and BRD4 expression, thereby inhibiting downstream NF-κB-driven transcriptional programs and killing ABC DLBCL cells. Using a high-throughput platform to screen for drug-drug synergy, we observed that the BET inhibitor JQ1 combined favorably with multiple drugs targeting B-cell receptor signaling, one pathway that activates IKK in ABC DLBCL. The BTK kinase inhibitor ibrutinib, which is in clinical development for the treatment of ABC DLBCL, synergized strongly with BET inhibitors in killing ABC DLBCL cells in vitro and in a xenograft mouse model. These findings provide a mechanistic basis for the clinical development of BET protein inhibitors in ABC DLBCL, particularly in combination with other modulators of oncogenic IKK signaling.

  5. FOXO1 is a direct target of EWS-Fli1 oncogenic fusion protein in Ewing's sarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liu, E-mail: lyang@u.washington.edu [Department of Orthopedics, University of Washington, Seattle, WA 98195 (United States); Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108 (United States); Hu, Hsien-Ming; Zielinska-Kwiatkowska, Anna; Chansky, Howard A. [Department of Orthopedics, University of Washington, Seattle, WA 98195 (United States); Medical Research Service, VA Puget Sound Health Care System, Seattle, WA 98108 (United States)

    2010-11-05

    Research highlights: {yields} Inducible and reversible siRNA knockdown of an oncogenic fusion protein such as EWS-Fli1 is feasible and more advantageous than other siRNA methods. {yields} The tumor suppressor gene FOXO1 is a new EWS-Fli1 target. {yields} While trans-activators are known for the FOXO1 gene, there has been no report on negative regulators of FOXO1 transcription. {yields} This study provides first evidence that the EWS-Fli1 oncogenic fusion protein can function as a transcriptional repressor of the FOXO1 gene. -- Abstract: Ewing's family tumors are characterized by a specific t(11;22) chromosomal translocation that results in the formation of EWS-Fli1 oncogenic fusion protein. To investigate the effects of EWS-Fli1 on gene expression, we carried out DNA microarray analysis after specific knockdown of EWS-Fli1 through transfection of synthetic siRNAs. EWS-Fli1 knockdown increased expression of genes such as DKK1 and p57 that are known to be repressed by EWS-Fli1 fusion protein. Among other potential EWS-Fli1 targets identified by our microarray analysis, we have focused on the FOXO1 gene since it encodes a potential tumor suppressor and has not been previously reported in Ewing's cells. To better understand how EWS-Fli1 affects FOXO1 expression, we have established a doxycycline-inducible siRNA system to achieve stable and reversible knockdown of EWS-Fli1 in Ewing's sarcoma cells. Here we show that FOXO1 expression in Ewing's cells has an inverse relationship with EWS-Fli1 protein level, and FOXO1 promoter activity is increased after doxycycline-induced EWS-Fli1 knockdown. In addition, we have found that direct binding of EWS-Fli1 to FOXO1 promoter is attenuated after doxycycline-induced siRNA knockdown of the fusion protein. Together, these results suggest that suppression of FOXO1 function by EWS-Fli1 fusion protein may contribute to cellular transformation in Ewing's family tumors.

  6. Proteome-wide identification of novel binding partners to the oncogenic fusion gene protein, NPM-ALK, using tandem affinity purification and mass spectrometry.

    Science.gov (United States)

    Wu, Fang; Wang, Peng; Young, Leah C; Lai, Raymond; Li, Liang

    2009-02-01

    Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), an oncogenic fusion gene protein that is characteristically found in a subset of anaplastic large cell lymphomas, promotes tumorigenesis through its functional and physical interactions with various biologically important proteins. The identification of these interacting proteins has proven to be useful to further our understanding of NPM-ALK-mediated tumorigenesis. For the first time, we performed a proteome-wide identification of NPM-ALK-binding proteins using tandem affinity purification and a highly sensitive mass spectrometric technique. Tandem affinity purification is a recently developed method that carries a lower background and higher sensitivity compared with the conventional immunoprecipitation-based protein purification protocols. The NPM-ALK gene was cloned into an HB-tagged vector and expressed in GP293 cells. Three independent experiments were performed and the reproducibility of the data was 68%. The vast majority of the previously reported NPM-ALK-binding proteins were detected. We also identified proteins that are involved in various cellular processes that were not previously described in association with NPM-ALK, such as MCM6 and MSH2 (DNA repair), Nup98 and importin 8 (subcellular protein transport), Stim1 (calcium signaling), 82Fip (RNA regulation), and BAG2 (proteosome degradation). We believe that these data highlight the functional diversity of NPM-ALK and provide new research directions for the study of the biology of this oncoprotein.

  7. Targeting the Human Papillomavirus E6 and E7 Oncogenes through Expression of the Bovine Papillomavirus Type 1 E2 Protein Stimulates Cellular Motility▿†

    Science.gov (United States)

    Morrison, Monique A.; Morreale, Richard J.; Akunuru, Shailaja; Kofron, Matthew; Zheng, Yi; Wells, Susanne I.

    2011-01-01

    Expression of the high-risk human papillomavirus (HPV) E6 and E7 oncogenes is essential for the initiation and maintenance of cervical cancer. The repression of both was previously shown to result in activation of their respective tumor suppressor targets, p53 and pRb, and subsequent senescence induction in cervical cancer cells. Consequently, viral oncogene suppression is a promising approach for the treatment of HPV-positive tumors. One well-established method of E6/E7 repression involves the reexpression of the viral E2 protein which is usually deleted in HPV-positive cancer cells. Here, we show that, surprisingly, bovine papillomavirus type 1 (BPV1) E2 but not RNA interference-mediated E6/E7 repression in HPV-positive cervical cancer cells stimulates cellular motility and invasion. Migration correlated with the dynamic formation of cellular protrusions and was dependent upon cell-to-cell contact. While E2-expressing migratory cells were senescent, migration was not a general feature of cellular senescence or cell cycle arrest and was specifically observed in HPV-positive cervical cancer cells. Interestingly, E2-expressing cells not only were themselves motile but also conferred increased motility to admixed HeLa cervical cancer cells. Together, our data suggest that repression of the viral oncogenes by E2 stimulates the motility of E6/E7-targeted cells as well as adjacent nontargeted cancer cells, thus raising the possibility that E2 expression may unfavorably increase the local invasiveness of HPV-positive tumors. PMID:21835799

  8. Targeting the human papillomavirus E6 and E7 oncogenes through expression of the bovine papillomavirus type 1 E2 protein stimulates cellular motility.

    Science.gov (United States)

    Morrison, Monique A; Morreale, Richard J; Akunuru, Shailaja; Kofron, Matthew; Zheng, Yi; Wells, Susanne I

    2011-10-01

    Expression of the high-risk human papillomavirus (HPV) E6 and E7 oncogenes is essential for the initiation and maintenance of cervical cancer. The repression of both was previously shown to result in activation of their respective tumor suppressor targets, p53 and pRb, and subsequent senescence induction in cervical cancer cells. Consequently, viral oncogene suppression is a promising approach for the treatment of HPV-positive tumors. One well-established method of E6/E7 repression involves the reexpression of the viral E2 protein which is usually deleted in HPV-positive cancer cells. Here, we show that, surprisingly, bovine papillomavirus type 1 (BPV1) E2 but not RNA interference-mediated E6/E7 repression in HPV-positive cervical cancer cells stimulates cellular motility and invasion. Migration correlated with the dynamic formation of cellular protrusions and was dependent upon cell-to-cell contact. While E2-expressing migratory cells were senescent, migration was not a general feature of cellular senescence or cell cycle arrest and was specifically observed in HPV-positive cervical cancer cells. Interestingly, E2-expressing cells not only were themselves motile but also conferred increased motility to admixed HeLa cervical cancer cells. Together, our data suggest that repression of the viral oncogenes by E2 stimulates the motility of E6/E7-targeted cells as well as adjacent nontargeted cancer cells, thus raising the possibility that E2 expression may unfavorably increase the local invasiveness of HPV-positive tumors.

  9. Ha-ras oncogene expression directed by a milk protein gene promoter: tissue specificity, hormonal regulation, and tumor induction in transgenic mice

    Energy Technology Data Exchange (ETDEWEB)

    Andres, A.C.; Schoenenberger, C.A.; Groner, B.; Henninghausen, L.; LeMeur, M.; Gelinger, P.

    1987-03-01

    The activated human Ha-ras oncogene was subjected to the control of the promoter region of the murine whey acidic protein (Wap) gene, which is expressed in mammary epithelial cells in response to lactogenic hormones. The Wap-ras gene was stably introduced into the mouse germ line of five transgenic mice (one male and four females). Wap-ras expression was observed in the mammary glands of lactating females in two lines derived from female founders. The tissue-directed and hormone-dependent Wap expression was conferred on the Ha-ras oncogene. The signals governing Wap expression are located within 2.5 kilobases of 5' flanking sequence. The other two lines derived from female founders did not express the chimeric gene. In the line derived from the male founder the Wap-ras gene is integrated into the Y chromosome. Expression was found in the salivary gland of male animals only. After a long latency, Wap-ras-expressing mice developed tumors. The tumors arose in tissues expressing Wap-ras - i.e., mammary or salivary glands. Compared to the corresponding nonmalignant tissues, Wap-ras expression was enhanced in the tumors.

  10. Human Papillomavirus Type 16 Mutant E7 Protein Induces Oncogenic Transformation via Up-regulation of Cyclin A and cdc25A

    Institute of Scientific and Technical Information of China (English)

    Jin-hua LIU; Yu-liang ZHANG; Li-qin ZHU; Yin-yu XU; Min ZHAO; Xin-xing WU

    2008-01-01

    A new mutant human papiUomavirus type 16 E7 gene, termed HPV16 HBE7, was isolated from cervical carcinoma biopsy samples from patients in an area with high incidence of cervical cancer (Hubei province, China). A previous study showed that the HPVI6 HBE7 protein was primarily cytoplasmic while wild-type HPV16 E7 protein, termed HPV16 WET, was concentrated in the nucleus. With the aim of studying the biological functions of HPV16 HBE7, the transforming potential of HPV16 HBE7 in NIH/3T3 cells was detected through observation of cell morphology, cell proliferation assay and anchorage-independent growth assay. The effect of HPVI6 HBE7 on cell cycle was examined by flow cytometry. Dual-luciferase reporter assay and RT-PCR were used to investigate the influence of HPVI6 HBE7 protein on the expression of regulation factors associated with GI/S checkpoint. The results showed that HPV16 HBE7 protein, as well as HPV16 WE7 protein, held transformation activity. NIH/3T3 cells expressing HPV16 HBE7 could easily transition from G1 phase into S phase and expressed high level of cyclin A and cdc25A. These results indicated HPV16 mutant E7 protein, located in the cytoplasm, induces oncogenic transformation of NIH/3T3 cells via up-regulation of cyclin A and cdc25A.

  11. Epitomics: IgG-epitome decoding of E6, E7 and L1 proteins from oncogenic human papillomavirus type 58

    Science.gov (United States)

    Xu, Wan-Xiang; Wang, Jian; Tang, Hai-Ping; He, Ya-Ping; Zhu, Qian-Xi; Gupta, Satish K.; Gu, Shao-Hua; Huang, Qiang; Ji, Chao-Neng; Liu, Ling-Feng; Li, Gui-Ling; Xu, Cong-Jian; Xie, Yi

    2016-01-01

    To enable rational multi-epitope vaccine and diagnostic antigen design, it is imperative to delineate complete IgG-epitome of the protein. Here, we describe results of IgG-epitome decoding of three proteins from high-risk (HR-) oncogenic human papillomavirus type 58 (HPV58). To reveal their entire epitomes, employing peptide biosynthetic approach, 30 precise linear B-cell epitopes (BCEs) were mapped on E6, E7 and L1 proteins using rabbits antisera to the respective recombinant proteins. Using sequence alignment based on BCE minimal motif, the specificity and conservativeness of each mapped BCE were delineated mainly among known HR-HPVs, including finding 3 broadly antibody cross-reactive BCEs of L1 that each covers almost all HR-HPVs. Western blots revealed that 13 of the 18 BCEs within L1-epitome were recognized by murine antisera to HPV58 virus-like particles, suggesting that these are antibody accessible BCEs. Also, a highly conserved epitope (YGD/XTL) of E6 was found to exist only in known common HR-HPVs, which could be used as the first peptide reference marker for judging HR-HPVs. Altogether, this study provides systemic and exhaustive information on linear BCEs of HR-HPV58 that will facilitate development of novel multi-epitope diagnostic reagents/chips for testing viral antibodies and ‘universal’ preventive HPV peptide vaccine based on L1 conserved BCEs. PMID:27708433

  12. Large-scale analysis of protein expression changes in human keratinocytes immortalized by human papilloma virus type 16 E6 and E7 oncogenes.

    Science.gov (United States)

    Merkley, Mark A; Hildebrandt, Ellen; Podolsky, Robert H; Arnouk, Hilal; Ferris, Daron G; Dynan, William S; Stöppler, Hubert

    2009-08-23

    Infection with high-risk type human papilloma viruses (HPVs) is associated with cervical carcinomas and with a subset of head and neck squamous cell carcinomas. Viral E6 and E7 oncogenes cooperate to achieve cell immortalization by a mechanism that is not yet fully understood. Here, human keratinocytes were immortalized by long-term expression of HPV type 16 E6 or E7 oncoproteins, or both. Proteomic profiling was used to compare expression levels for 741 discrete protein features. Six replicate measurements were performed for each group using two-dimensional difference gel electrophoresis (2D-DIGE). The median within-group coefficient of variation was 19-21%. Significance of between-group differences was tested based on Significance Analysis of Microarray and fold change. Expression of 170 (23%) of the protein features changed significantly in immortalized cells compared to primary keratinocytes. Most of these changes were qualitatively similar in cells immortalized by E6, E7, or E6/7 expression, indicating convergence on a common phenotype, but fifteen proteins (~2%) were outliers in this regulatory pattern. Ten demonstrated opposite regulation in E6- and E7-expressing cells, including the cell cycle regulator p16INK4a; the carbohydrate binding protein Galectin-7; two differentially migrating forms of the intermediate filament protein Cytokeratin-7; HSPA1A (Hsp70-1); and five unidentified proteins. Five others had a pattern of expression that suggested cooperativity between the co-expressed oncoproteins. Two of these were identified as forms of the small heat shock protein HSPB1 (Hsp27). This large-scale analysis provides a framework for understanding the cooperation between E6 and E7 oncoproteins in HPV-driven carcinogenesis.

  13. Large-scale analysis of protein expression changes in human keratinocytes immortalized by human papilloma virus type 16 E6 and E7 oncogenes

    Directory of Open Access Journals (Sweden)

    Arnouk Hilal

    2009-08-01

    Full Text Available Abstract Background Infection with high-risk type human papilloma viruses (HPVs is associated with cervical carcinomas and with a subset of head and neck squamous cell carcinomas. Viral E6 and E7 oncogenes cooperate to achieve cell immortalization by a mechanism that is not yet fully understood. Here, human keratinocytes were immortalized by long-term expression of HPV type 16 E6 or E7 oncoproteins, or both. Proteomic profiling was used to compare expression levels for 741 discrete protein features. Results Six replicate measurements were performed for each group using two-dimensional difference gel electrophoresis (2D-DIGE. The median within-group coefficient of variation was 19–21%. Significance of between-group differences was tested based on Significance Analysis of Microarray and fold change. Expression of 170 (23% of the protein features changed significantly in immortalized cells compared to primary keratinocytes. Most of these changes were qualitatively similar in cells immortalized by E6, E7, or E6/7 expression, indicating convergence on a common phenotype, but fifteen proteins (~2% were outliers in this regulatory pattern. Ten demonstrated opposite regulation in E6- and E7-expressing cells, including the cell cycle regulator p16INK4a; the carbohydrate binding protein Galectin-7; two differentially migrating forms of the intermediate filament protein Cytokeratin-7; HSPA1A (Hsp70-1; and five unidentified proteins. Five others had a pattern of expression that suggested cooperativity between the co-expressed oncoproteins. Two of these were identified as forms of the small heat shock protein HSPB1 (Hsp27. Conclusion This large-scale analysis provides a framework for understanding the cooperation between E6 and E7 oncoproteins in HPV-driven carcinogenesis.

  14. Integrin α2β1 inhibits MST1 kinase phosphorylation and activates Yes-associated protein oncogenic signaling in hepatocellular carcinoma.

    Science.gov (United States)

    Wong, Kwong-Fai; Liu, Angela M; Hong, Wanjin; Xu, Zhi; Luk, John M

    2016-11-22

    The Hippo pathway regulates the down-stream target Yes-associated protein (YAP) to maintain organ homeostasis, which is commonly inactivated in many types of cancers. However, how cell adhesion dysregulates the Hippo pathway activating YAP oncogene in hepatocellular carcinoma (HCC) remains unclear. Our findings demonstrate that α2β1 integrin (but not other β1 integrins) expressed in HCC cells, after binding to collagen extracellular matrix, could inhibit MST1 kinase phosphorylation and activate YAP pro-oncogenic activities. Knockdown of integrin α2 gene (ITGA2) suppressed YAP targeted gene expression in vitro. α2β1 and collagen binding resulted in suppressing Hippo signaling of mammalian sterile 20-like kinase 1 (MST1) and Large tumor suppressor homolog 1 (LATS1) with concomitant activation of YAP-mediated connective tissue growth factor (CTGF) gene expression. In vitro kinase assay showed that MST1 is an immediate downstream target of integrin α2 with S1180 residue as the critical phosphorylation site. Clinical correlational analysis using a gene expression dataset of 228 HCC tumors revealed that ITGA2 expression was significantly associated with tumor progression, and co-expression with YAP targeted genes (AXL receptor tyrosine kinase, CTGF, cyclin D1, glypican 3, insulin like growth factor 1 receptor, and SRY-box 4) correlated with survivals of HCC patients. In conclusion, α2β1 integrin activation through cellular adhesion impacts the Hippo pathway in solid tumors and modulates MST1-YAP signaling cascade. Targeting integrin α2 holds promises for treating YAP-positive HCC.

  15. Acidosis decreases c-Myc oncogene expression in human lymphoma cells: a role for the proton-sensing G protein-coupled receptor TDAG8.

    Science.gov (United States)

    Li, Zhigang; Dong, Lixue; Dean, Eric; Yang, Li V

    2013-10-11

    Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs). Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression.

  16. Acidosis Decreases c-Myc Oncogene Expression in Human Lymphoma Cells: A Role for the Proton-Sensing G Protein-Coupled Receptor TDAG8

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-10-01

    Full Text Available Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65 is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs. Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression.

  17. T-cell responses to oncogenic merkel cell polyomavirus proteins distinguish patients with merkel cell carcinoma from healthy donors

    DEFF Research Database (Denmark)

    Skou, Rikke Birgitte Lyngaa; Pedersen, Natasja Wulff; Schrama, David

    2014-01-01

    PURPOSE: Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with strong evidence of viral carcinogenesis. The association of MCC with the Merkel cell polyomavirus (MCPyV) may explain the explicit immunogenicity of MCC. Indeed, MCPyV-encoded proteins are likely targets for cytotoxic...... the MCPyV oncoprotein large T and small T antigens and the virus capsid protein VP1 for potential T-cell epitopes, and tested for MHC class I affinity. We confirmed the relevance of these epitopes using a high-throughput platform for T-cell enrichment and combinatorial encoding of MHC class I multimers...

  18. Human cytomegalovirus and mucoepidermoid carcinoma of salivary glands: cell-specific localization of active viral and oncogenic signaling proteins is confirmatory of a causal relationship.

    Science.gov (United States)

    Melnick, Michael; Sedghizadeh, Parish P; Allen, Carl M; Jaskoll, Tina

    2012-02-01

    Human cytomegalovirus (hCMV) infection is common. Although still controversial, there is growing evidence that active hCMV infection is associated with a variety of malignancies, including brain, breast, lung, colon, and prostate. Given that hCMV is frequently resident in salivary gland (SG) ductal epithelium, we hypothesized that hCMV would be important to the pathogenesis of SG mucoepidermoid carcinoma (MEC). This was initially supported by our finding that purified CMV induces malignant transformation in SG cells in an in vitro mouse model, and utilizes a pathogenic pathway previously reported for human MEC. Here we present the histologic and molecular characterizations of 39 human SG MECs selected randomly from a repository of cases spanning 2004-2011. Serial sections were obtained from formalin-fixed, paraffin embedded, tissue blocks from previous incisional or excisional biopsies. Immunohistochemical assays were performed for active hCMV proteins (IE1 and pp65) and the activated COX/AREG/EGFR/ERK signaling pathway. All four prospective causal criteria for viruses and cancer are fully satisfied: (1) protein markers for active hCMV are present in 97% of MECs; (2) markers of active hCMV are absent in non-neoplastic SG tissues; (3) hCMV-specific proteins (IE1, pp65) are in specific cell types and expression is positively correlated with severity; (4) hCMV correlates and colocalizes with an upregulation and activation of an established oncogenic signaling pathway (COX/AREG/EGFR/ERK). Thus, the evidential support reported here and previously in a mouse model is strongly confirmatory of a causal relationship between hCMV and SG mucoepidermoid carcinoma. To our knowledge, this is the first demonstration of hCMV's role in human oncogenesis that fully responds to all of Koch's Postulates as revised for viruses and cancer. In the absence of any contrary evidence, hCMV can reasonably be designated an "oncovirus."

  19. microRNA-183 plays as oncogenes by increasing cell proliferation, migration and invasion via targeting protein phosphatase 2A in renal cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Mingning, E-mail: lcuzfy@163.com; Liu, Lei, E-mail: leiliulab@163.com; Chen, Lieqian, E-mail: lieqianchen@163.com; Tan, Guobin, E-mail: guobintan@163.com; Liang, Ziji, E-mail: zijilianglab@163.com; Wang, Kangning, E-mail: kangningwanglab@163.com; Liu, Jianjun, E-mail: jianjunliulab@163.com; Chen, Hege, E-mail: hegechen@163.com

    2014-09-12

    Highlights: • miR-183 was up-regulated in renal cancer tissues. • Inhibition of endogenous miR-183 suppressed renal cancer cell growth and metastasis. • miR-183 increased cell growth and metastasis. • miR-183 regulated renal cancer cell growth and metastasis via directly targeting tumor suppressor protein phosphatase 2A. - Abstract: The aim of this study was to investigate the function of miR-183 in renal cancer cells and the mechanisms miR-183 regulates this process. In this study, level of miR-183 in clinical renal cancer specimens was detected by quantitative real-time PCR. miR-183 was up- and down-regulated in two renal cancer cell lines ACHN and A498, respectively, and cell proliferation, Caspase 3/7 activity, colony formation, in vitro migration and invasion were measured; and then the mechanisms of miR-183 regulating was analyzed. We found that miR-183 was up-regulated in renal cancer tissues; inhibition of endogenous miR-183 suppressed in vitro cell proliferation, colony formation, migration, and invasion and stimulated Caspase 3/7 activity; up-regulated miR-183 increased cell growth and metastasis and suppressed Caspase 3/7 activity. We also found that miR-183 directly targeted tumor suppressor, specifically the 3′UTR of three subunits of protein phosphatase 2A (PP2A-Cα, PP2A-Cβ, and PP2A-B56-γ) transcripts, inhibiting their expression and regulated the downstream regulators p21, p27, MMP2/3/7 and TIMP1/2/3/4. These results revealed the oncogenes role of miR-183 in renal cancer cells via direct targeting protein phosphatase 2A.

  20. Oncogenic kinase NPM/ALK induces through STAT3 expression of immunosuppressive protein CD274 (PD-L1, B7-H1).

    Science.gov (United States)

    Marzec, Michal; Zhang, Qian; Goradia, Ami; Raghunath, Puthiyaveettil N; Liu, Xiaobin; Paessler, Michele; Wang, Hong Yi; Wysocka, Maria; Cheng, Mangeng; Ruggeri, Bruce A; Wasik, Mariusz A

    2008-12-30

    The mechanisms of malignant cell transformation caused by the oncogenic, chimeric nucleophosmin (NPM)/anaplastic lymphoma kinase (ALK) remain only partially understood, with most of the previous studies focusing mainly on the impact of NPM/ALK on cell survival and proliferation. Here we report that the NPM/ALK-carrying T cell lymphoma (ALK+TCL) cells strongly express the immunosuppressive cell-surface protein CD274 (PD-L1, B7-H1), as determined on the mRNA and protein level. The CD274 expression is strictly dependent on the expression and enzymatic activity of NPM/ALK, as demonstrated by inhibition of the NPM/ALK function in ALK+TCL cells by the small molecule ALK inhibitor CEP-14083 and by documenting CD274 expression in IL-3-depleted BaF3 cells transfected with the wild-type NPM/ALK, but not the kinase-inactive NPM/ALK K210R mutant or empty vector alone. NPM/ALK induces CD274 expression by activating its key signal transmitter, transcription factor STAT3. STAT3 binds to the CD274 gene promoter in vitro and in vivo, as shown in the gel electromobility shift and chromatin immunoprecipitation assays, and is required for the PD-L1 gene expression, as demonstrated by siRNA-mediated STAT3 depletion. These findings identify an additional cell-transforming property of NPM/ALK and describe a direct link between an oncoprotein and an immunosuppressive cell-surface protein. These results also provide an additional rationale to therapeutically target NPM/ALK and STAT3 in ALK+TCL. Finally, they suggest that future immunotherapeutic protocols for this type of lymphoma may need to include the inhibition of NPM/ALK and STAT3 to achieve optimal clinical efficacy.

  1. Oncogenic viruses and cancer

    Institute of Scientific and Technical Information of China (English)

    Guangxiang; George; Luo; Jing-hsiung; James; Ou

    2015-01-01

    <正>This special issue of the journal is dedicated to the important topic of oncogenic viruses and cancer.It contains seven review articles covering all known oncogenic viruses except for human T-lymphotropic virus type1(HTLV-1).These review articles are contributed by experts on specific viruses and their associated human cancers.Viruses account for about 20%of total human cancer cases.Although many viruses can cause various tumors in animals,only seven of them

  2. Imaging oncogene expression

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Archana [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States)], E-mail: Archana.Mukherjee@jefferson.edu; Wickstrom, Eric [Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233S, 10th street, Philadelphia, PA 19107 (United States)], E-mail: eric@tesla.jci.tju.edu; Thakur, Mathew L. [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States)], E-mail: Mathew.Thakur@jefferson.edu

    2009-05-15

    This review briefly outlines the importance of molecular imaging, particularly imaging of endogenous gene expression for noninvasive genetic analysis of radiographic masses. The concept of antisense imaging agents and the advantages and challenges in the development of hybridization probes for in vivo imaging are described. An overview of the investigations on oncogene expression imaging is given. Finally, the need for further improvement in antisense-based imaging agents and directions to improve oncogene mRNA targeting is stated.

  3. Hepatocellular carcinoma-derived exosomes promote motility of immortalized hepatocyte through transfer of oncogenic proteins and RNAs.

    Science.gov (United States)

    He, Mian; Qin, Hao; Poon, Terence C W; Sze, Siu-Ching; Ding, Xiaofan; Co, Ngai Na; Ngai, Sai-Ming; Chan, Ting-Fung; Wong, Nathalie

    2015-09-01

    Exosomes are increasingly recognized as important mediators of cell-cell communication in cancer progression through the horizontal transfer of RNAs and proteins to neighboring or distant cells. Hepatocellular carcinoma (HCC) is a highly malignant cancer, whose metastasis is largely influenced by the tumor microenvironment. The possible role of exosomes in the interactions between HCC tumor cell and its surrounding hepatic milieu are however largely unknown. In this study, we comprehensively characterized the exosomal RNA and proteome contents derived from three HCC cell lines (HKCI-C3, HKCI-8 and MHCC97L) and an immortalized hepatocyte line (MIHA) using Ion Torrent sequencing and mass spectrometry, respectively. RNA deep sequencing and proteomic analysis revealed exosomes derived from metastatic HCC cell lines carried a large number of protumorigenic RNAs and proteins, such as MET protooncogene, S100 family members and the caveolins. Of interest, we found that exosomes from motile HCC cell lines could significantly enhance the migratory and invasive abilities of non-motile MIHA cell. We further demonstrated that uptake of these shuttled molecules could trigger PI3K/AKT and MAPK signaling pathways in MIHA with increased secretion of active MMP-2 and MMP-9. Our study showed for the first time that HCC-derived exosomes could mobilize normal hepatocyte, which may have implication in facilitating the protrusive activity of HCC cells through liver parenchyma during the process of metastasis.

  4. Macrophage Capping Protein CapG Is a Putative Oncogene Involved in Migration and Invasiveness in Ovarian Carcinoma

    Directory of Open Access Journals (Sweden)

    J. Glaser

    2014-01-01

    Full Text Available The actin binding protein CapG modulates cell motility by interacting with the cytoskeleton. CapG is associated with tumor progression in different nongynecologic tumor entities and overexpression in breast cancer cell lines correlates with a more invasive phenotype in vitro. Here, we report a significant CapG overexpression in 18/47 (38% of ovarian carcinomas (OC analyzed by qRealTime-PCR analyses. Functional analyses in OC cell lines through siRNA mediated CapG knockdown and CapG overexpression showed CapG-dependent cell migration and invasiveness. A single nucleotide polymorphism rs6886 inside the CapG gene was identified, affecting a CapG phosphorylation site and thus potentially modifying CapG function. The minor allele frequency (MAF of SNP rs6886 (c.1004A/G was higher and the homozygous (A/A, His335 genotype was significantly more prevalent in patients with fallopian tube carcinomas (50% as in controls (10%. With OC being one of the most lethal cancer diseases, the detection of novel biomarkers such as CapG could reveal new diagnostic and therapeutic targets. Moreover, in-depth analyses of SNP rs6886 related to FTC and OC will contribute to a better understanding of carcinogenesis and progression of OC.

  5. Oncogenic Brain Metazoan Parasite Infection

    Directory of Open Access Journals (Sweden)

    Angela N. Spurgeon

    2013-01-01

    Full Text Available Multiple observations suggest that certain parasitic infections can be oncogenic. Among these, neurocysticercosis is associated with increased risk for gliomas and hematologic malignancies. We report the case of a 71-year-old woman with colocalization of a metazoan parasite, possibly cysticercosis, and a WHO grade IV neuroepithelial tumor with exclusively neuronal differentiation by immunohistochemical stains (immunopositive for synaptophysin, neurofilament protein, and Neu-N and not for GFAP, vimentin, or S100. The colocalization and temporal relationship of these two entities suggest a causal relationship.

  6. Oncogenic H-Ras Reprograms Madin-Darby Canine Kidney (MDCK) Cell-derived Exosomal Proteins Following Epithelial-Mesenchymal Transition*

    Science.gov (United States)

    Tauro, Bow J.; Mathias, Rommel A.; Greening, David W.; Gopal, Shashi K.; Ji, Hong; Kapp, Eugene A.; Coleman, Bradley M.; Hill, Andrew F.; Kusebauch, Ulrike; Hallows, Janice L.; Shteynberg, David; Moritz, Robert L.; Zhu, Hong-Jian; Simpson, Richard J.

    2013-01-01

    Epithelial-mesenchymal transition (EMT) is a highly conserved morphogenic process defined by the loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. EMT is associated with increased aggressiveness, invasiveness, and metastatic potential in carcinoma cells. To assess the contribution of extracellular vesicles following EMT, we conducted a proteomic analysis of exosomes released from Madin-Darby canine kidney (MDCK) cells, and MDCK cells transformed with oncogenic H-Ras (21D1 cells). Exosomes are 40–100 nm membranous vesicles originating from the inward budding of late endosomes and multivesicular bodies and are released from cells on fusion of multivesicular bodies with the plasma membrane. Exosomes from MDCK cells (MDCK-Exos) and 21D1 cells (21D1-Exos) were purified from cell culture media using density gradient centrifugation (OptiPrep™), and protein content identified by GeLC-MS/MS proteomic profiling. Both MDCK- and 21D1-Exos populations were morphologically similar by cryo-electron microscopy and contained stereotypical exosome marker proteins such as TSG101, Alix, and CD63. In this study we show that the expression levels of typical EMT hallmark proteins seen in whole cells correlate with those observed in MDCK- and 21D1-Exos, i.e. reduction of characteristic inhibitor of angiogenesis, thrombospondin-1, and epithelial markers E-cadherin, and EpCAM, with a concomitant up-regulation of mesenchymal makers such as vimentin. Further, we reveal that 21D1-Exos are enriched with several proteases (e.g. MMP-1, -14, -19, ADAM-10, and ADAMTS1), and integrins (e.g. ITGB1, ITGA3, and ITGA6) that have been recently implicated in regulating the tumor microenvironment to promote metastatic progression. A salient finding of this study was the unique presence of key transcriptional regulators (e.g. the master transcriptional regulator YBX1) and core splicing complex components (e.g. SF3B1, SF3B3, and SFRS1) in mesenchymal 21D1-Exos. Taken

  7. Pesticides and oncogenic modulation.

    Science.gov (United States)

    Vakonaki, Elena; Androutsopoulos, Vasilis P; Liesivuori, Jyrki; Tsatsakis, Aristidis M; Spandidos, Demetrios A

    2013-05-10

    Pesticides constitute a diverse class of chemicals used for the protection of agricultural products. Several lines of evidence demonstrate that organochlorine and organophosphate pesticides can cause malignant transformation of cells in in vitro and in vivo models. In the current minireview a comprehensive summary of recent in vitro findings is presented along with data reported from human population studies, regarding the impact of pesticide exposure on activation or dysregulation of oncogenes and tumor suppressor genes. Substantial mechanistic work suggests that pesticides are capable of inducing mutations in oncogenes and increase their transcriptional expression in vitro, whereas human population studies indicate associations between pesticide exposure levels and mutation occurrence in cancer-related genes. Further work is required to fully explore the exact mechanisms by which pesticide exposure affects the integrity and normal function of oncogenes and tumor suppressor genes in human populations.

  8. The Oncogenic Fusion Proteins SET-Nup214 and Sequestosome-1 (SQSTM1)-Nup214 Form Dynamic Nuclear Bodies and Differentially Affect Nuclear Protein and Poly(A)+ RNA Export.

    Science.gov (United States)

    Port, Sarah A; Mendes, Adélia; Valkova, Christina; Spillner, Christiane; Fahrenkrog, Birthe; Kaether, Christoph; Kehlenbach, Ralph H

    2016-10-28

    Genetic rearrangements are a hallmark of several forms of leukemia and can lead to oncogenic fusion proteins. One example of an affected chromosomal region is the gene coding for Nup214, a nucleoporin that localizes to the cytoplasmic side of the nuclear pore complex (NPC). We investigated two such fusion proteins, SET-Nup214 and SQSTM1 (sequestosome)-Nup214, both containing C-terminal portions of Nup214. SET-Nup214 nuclear bodies containing the nuclear export receptor CRM1 were observed in the leukemia cell lines LOUCY and MEGAL. Overexpression of SET-Nup214 in HeLa cells leads to the formation of similar nuclear bodies that recruit CRM1, export cargo proteins, and certain nucleoporins and concomitantly affect nuclear protein and poly(A)(+) RNA export. SQSTM1-Nup214, although mostly cytoplasmic, also forms nuclear bodies and inhibits nuclear protein but not poly(A)(+) RNA export. The interaction of the fusion proteins with CRM1 is RanGTP-dependent, as shown in co-immunoprecipitation experiments and binding assays. Further analysis revealed that the Nup214 parts mediate the inhibition of nuclear export, whereas the SET or SQSTM1 part determines the localization of the fusion protein and therefore the extent of the effect. SET-Nup214 nuclear bodies are highly mobile structures, which are in equilibrium with the nucleoplasm in interphase and disassemble during mitosis or upon treatment of cells with the CRM1-inhibitor leptomycin B. Strikingly, we found that nucleoporins can be released from nuclear bodies and reintegrated into existing NPC. Our results point to nuclear bodies as a means of preventing the formation of potentially insoluble and harmful protein aggregates that also may serve as storage compartments for nuclear transport factors.

  9. Comparative analysis of oncogenic properties and nuclear factor-kappaB activity of latent membrane protein 1 natural variants from Hodgkin's lymphoma's Reed-Sternberg cells and normal B-lymphocytes.

    Science.gov (United States)

    Faumont, Nathalie; Chanut, Aurélie; Benard, Alan; Cogne, Nadine; Delsol, Georges; Feuillard, Jean; Meggetto, Fabienne

    2009-03-01

    In Epstein-Barr virus-associated Hodgkin's lymphomas, neoplastic Reed-Sternberg cells and surrounding non-tumor B-cells contain different variants of the LMP1-BNLF1 oncogene. In this study, we raised the question of functional properties of latent membrane protein 1 (LMP1) natural variants from both Reed-Sternberg and non-tumor B-cells. Twelve LMP1 natural variants from Reed-Sternberg cells, non-tumor B-cells of Hodgkin's lymphomas and from B-cells of benign reactive lymph nodes were cloned, sequenced and stably transfected in murine recombinant interleukin-3-dependent Ba/F3 cells to search for relationships between LMP1 cellular origin and oncogenic properties as well as nuclear factor-kappaB activation, and apoptosis protection. LMP1 variants of Reed-Sternberg cell origin were often associated with increased mutation rate and with recurrent genetic events, such as del15bp associated with S to N replacement at codon 309, and four substitutions I85L, F106Y, I122L, and M129I. Oncogenic potential (growth factor-independence plus clonogenicity) was consistently associated with LMP1 variants from Reed-Sternberg cells, but inconstantly for LMP1-variants from non-tumor B-cells. Analysis of LMP1 variants from both normal B-cells and Reed-Sternberg cells indicates that protection against apoptosis through activation of nuclear factor-kappaB - whatever the cellular origin of LMP1 - was maintained intact, regardless of the mutational pattern. Taken together, our results demonstrate that preserved nuclear factor-kappaB activity and protection against apoptosis would be the minimal prerequisites for all LMP1 natural variants from both normal and tumor cells in Hodgkin's lymphomas, and that oncogenic potential would constitute an additional feature for LMP1 natural variants in Reed-Sternberg cells.

  10. G protein-coupled receptors engage the mammalian Hippo pathway through F-actin: F-Actin, assembled in response to Galpha12/13 induced RhoA-GTP, promotes dephosphorylation and activation of the YAP oncogene.

    Science.gov (United States)

    Regué, Laura; Mou, Fan; Avruch, Joseph

    2013-05-01

    The Hippo pathway, a cascade of protein kinases that inhibits the oncogenic transcriptional coactivators YAP and TAZ, was discovered in Drosophila as a major determinant of organ size in development. Known modes of regulation involve surface proteins that mediate cell-cell contact or determine epithelial cell polarity which, in a tissue-specific manner, use intracellular complexes containing FERM domain and actin-binding proteins to modulate the kinase activities or directly sequester YAP. Unexpectedly, recent work demonstrates that GPCRs, especially those signaling through Galpha12/13 such as the protease activated receptor PAR1, cause potent YAP dephosphorylation and activation. This response requires active RhoA GTPase and increased assembly of filamentous (F-)actin. Morever, cell architectures that promote F-actin assembly per se also activate YAP by kinase-dependent and independent mechanisms. These findings unveil the ability of GPCRs to activate the YAP oncogene through a newly recognized signaling function of the actin cytoskeleton, likely to be especially important for normal and cancerous stem cells.

  11. Acetylation of the c-MYC oncoprotein is required for cooperation with the HTLV-1 p30{sup II} accessory protein and the induction of oncogenic cellular transformation by p30{sup II}/c-MYC

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, Megan M.; Ko, Bookyung; Kim, Janice; Brady, Rebecca; Heatley, Hayley C.; He, Jeffrey; Harrod, Carolyn K.; Barnett, Braden [Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275-0376 (United States); Ratner, Lee [Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Lairmore, Michael D. [University of California-Davis, School of Veterinary Medicine, One Shields Avenue, Davis, CA 95618 (United States); Martinez, Ernest [Department of Biochemistry, University of California, Riverside, CA 92521 (United States); Lüscher, Bernhard [Institute of Biochemistry, Klinikum, RWTH Aachen University, Pauwelsstrasse 30, 52057 Aachen (Germany); Robson, Craig N. [Northern Institute for Cancer Research, Newcastle University, The Medical School, Newcastle upon Tyne, NE2 4HH (United Kingdom); Henriksson, Marie [Department of Microbiology, Cell and Tumor Biology, Karolinska Institutet, Stockholm (Sweden); Harrod, Robert, E-mail: rharrod@smu.edu [Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275-0376 (United States)

    2015-02-15

    The human T-cell leukemia retrovirus type-1 (HTLV-1) p30{sup II} protein is a multifunctional latency-maintenance factor that negatively regulates viral gene expression and deregulates host signaling pathways involved in aberrant T-cell growth and proliferation. We have previously demonstrated that p30{sup II} interacts with the c-MYC oncoprotein and enhances c-MYC-dependent transcriptional and oncogenic functions. However, the molecular and biochemical events that mediate the cooperation between p30{sup II} and c-MYC remain to be completely understood. Herein we demonstrate that p30{sup II} induces lysine-acetylation of the c-MYC oncoprotein. Acetylation-defective c-MYC Lys→Arg substitution mutants are impaired for oncogenic transformation with p30{sup II} in c-myc{sup −/−} HO15.19 fibroblasts. Using dual-chromatin-immunoprecipitations (dual-ChIPs), we further demonstrate that p30{sup II} is present in c-MYC-containing nucleoprotein complexes in HTLV-1-transformed HuT-102 T-lymphocytes. Moreover, p30{sup II} inhibits apoptosis in proliferating cells expressing c-MYC under conditions of genotoxic stress. These findings suggest that c-MYC-acetylation is required for the cooperation between p30{sup II}/c-MYC which could promote proviral replication and contribute to HTLV-1-induced carcinogenesis. - Highlights: • Acetylation of c-MYC is required for oncogenic transformation by HTLV-1 p30{sup II}/c-MYC. • Acetylation-defective c-MYC mutants are impaired for foci-formation by p30{sup II}/c-MYC. • The HTLV-1 p30{sup II} protein induces lysine-acetylation of c-MYC. • p30{sup II} is present in c-MYC nucleoprotein complexes in HTLV-1-transformed T-cells. • HTLV-1 p30{sup II} inhibits apoptosis in c-MYC-expressing proliferating cells.

  12. The mystery of oncogenic KRAS: Lessons from studying its wild-type counter part.

    Science.gov (United States)

    Chang, Yuan-I; Damnernsawad, Alisa; Kong, Guangyao; You, Xiaona; Wang, Demin; Zhang, Jing

    2016-07-22

    Using conditional knock-in mouse models, we and others have shown that despite the very high sequence identity between Nras and Kras proteins, oncogenic Kras displays a much stronger leukemogenic activity than oncogenic Nras in vivo. In this manuscript, we will summarize our recent work of characterizing wild-type Kras function in adult hematopoiesis and in oncogenic Kras-induced leukemogenesis. We attribute the strong leukemogenic activity of oncogenic Kras to 2 unique aspects of Kras signaling. First, Kras is required in mediating cell type- and cytokine-specific ERK1/2 signaling. Second, oncogenic Kras, but not oncogenic Nras, induces hyperactivation of wild-type Ras, which significantly enhances Ras signaling in vivo. We will also discuss a possible mechanism that mediates oncogenic Kras-evoked hyperactivation of wild-type Ras and a potential approach to down-regulate oncogenic Kras signaling.

  13. Oncogene v-jun modulates DNA replication.

    Science.gov (United States)

    Wasylyk, C; Schneikert, J; Wasylyk, B

    1990-07-01

    Cell transformation leads to alterations in both transcription and DNA replication. Activation of transcription by the expression of a number of transforming oncogenes is mediated by the transcription factor AP1 (Herrlich & Ponta, 1989; Imler & Wasylyk, 1989). AP1 is a composite transcription factor, consisting of members of the jun and fos gene-families. c-jun and c-fos are progenitors of oncogenes, suggestion that an important transcriptional event in cell transformation is altered activity of AP1, which may arise either indirectly by oncogene expression or directly by structural modification of AP1. We report here that the v-jun oncogene and its progenitor c-jun, as fusion proteins with the lex-A-repressor DNA binding domain, can activate DNA replication from the Polyoma virus (Py) origin of replication, linked to the lex-A operator. The transcription-activation region of v-jun is required for activation of replication. When excess v-jun is expressed in the cell, replication is inhibited or 'squelched'. These results suggest that one consequence of deregulated jun activity could be altered DNA replication and that there are similarities in the way v-jun activates replication and transcription.

  14. Oncogenes in melanoma: an update.

    Science.gov (United States)

    Kunz, Manfred

    2014-01-01

    Melanoma is a highly aggressive tumour with poor prognosis in the metastatic stage. BRAF, NRAS, and KIT are three well-known oncogenes involved in melanoma pathogenesis. Targeting of mutated BRAF kinase has recently been shown to significantly improve overall survival of metastatic melanoma patients, underscoring the particular role of this oncogene in melanoma biology. However, recurrences regularly occur within several months, which supposedly involve further oncogenes. Moreover, oncogenic driver mutations have not been described for up to 30% of all melanomas. In order to obtain a more complete picture of the mutational landscape of melanoma, more recent studies used high-throughput DNA sequencing technologies. A number of new oncogene candidates such as MAPK1/2, ERBB4, GRIN2A, GRM3, RAC1, and PREX2 were identified. Their particular role in melanoma biology is currently under investigation. Evidence for the functional relevance of some of these new oncogene candidates has been provided in in vitro and in vivo experiments. However, these findings await further validation in clinical studies. This review provides an overview on well-known melanoma oncogenes and new oncogene candidates, based on recent high-throughput sequencing studies. The list of genes discussed herein is of course not complete but highlights some of the most significant of recent findings in this area. The new candidates may support more individualized treatment approaches for metastatic melanoma patients in the future.

  15. Activation of Mas oncogene-related gene (Mrg) C receptors enhances morphine-induced analgesia through modulation of coupling of μ-opioid receptor to Gi-protein in rat spinal dorsal horn.

    Science.gov (United States)

    Wang, D; Chen, T; Zhou, X; Couture, R; Hong, Y

    2013-12-03

    Mas oncogene-related gene (Mrg) G protein-coupled receptors are exclusively expressed in small-sized neurons in trigeminal and dorsal root ganglia (DRG) in mammals. The present study investigated the effect of MrgC receptor activation on morphine analgesic potency and addressed its possible mechanisms. Intrathecal (i.t.) administration of the specific MrgC receptor agonist bovine adrenal medulla 8-22 (BAM8-22, 3 nmol) increased morphine-induced analgesia and shifted the morphine dose-response curve to the left in rats. Acute morphine (5 μg) reduced the coupling of μ-opioid receptors (MORs) to Gi-, but not Gs-, protein in the spinal dorsal horn. The i.t. BAM8-22 (3 nmol) prevented this change of G-protein repertoire while the inactive MrgC receptor agonist BAM8-18 (3 nmol, i.t.) failed to do so. A double labeling study showed the co-localization of MrgC and MORs in DRG neurons. The i.t. BAM8-22 also increased the coupling of MORs to Gi-protein and recruited Gi-protein from cytoplasm to the cell membrane in the spinal dorsal horn. Application of BAM8-22 (10nM) in the cultured ganglion explants for 30 min increased Gi-protein mRNA, but not Gs-protein mRNA. The present study demonstrated that acute administration of morphine inhibited the repertoire of MOR/Gi-protein coupling in the spinal dorsal horn in vivo. The findings highlight a novel mechanism by which the activation of MrgC receptors can modulate the coupling of MORs with Gi-protein to enhance morphine-induced analgesia. Hence, adjunct treatment of MrgC agonist BAM8-22 may be of therapeutic value to relieve pain.

  16. NF2 Loss Promotes Oncogenic RAS-Induced Thyroid Cancers via YAP-Dependent Transactivation of RAS Proteins and Sensitizes Them to MEK Inhibition.

    Science.gov (United States)

    Garcia-Rendueles, Maria E R; Ricarte-Filho, Julio C; Untch, Brian R; Landa, Iňigo; Knauf, Jeffrey A; Voza, Francesca; Smith, Vicki E; Ganly, Ian; Taylor, Barry S; Persaud, Yogindra; Oler, Gisele; Fang, Yuqiang; Jhanwar, Suresh C; Viale, Agnes; Heguy, Adriana; Huberman, Kety H; Giancotti, Filippo; Ghossein, Ronald; Fagin, James A

    2015-11-01

    Ch22q LOH is preferentially associated with RAS mutations in papillary and in poorly differentiated thyroid cancer (PDTC). The 22q tumor suppressor NF2, encoding merlin, is implicated in this interaction because of its frequent loss of function in human thyroid cancer cell lines. Nf2 deletion or Hras mutation is insufficient for transformation, whereas their combined disruption leads to murine PDTC with increased MAPK signaling. Merlin loss induces RAS signaling in part through inactivation of Hippo, which activates a YAP-TEAD transcriptional program. We find that the three RAS genes are themselves YAP-TEAD1 transcriptional targets, providing a novel mechanism of promotion of RAS-induced tumorigenesis. Moreover, pharmacologic disruption of YAP-TEAD with verteporfin blocks RAS transcription and signaling and inhibits cell growth. The increased MAPK output generated by NF2 loss in RAS-mutant cancers may inform therapeutic strategies, as it generates greater dependency on the MAPK pathway for viability. Intensification of mutant RAS signaling through copy-number imbalances is commonly associated with transformation. We show that NF2/merlin inactivation augments mutant RAS signaling by promoting YAP/TEAD-driven transcription of oncogenic and wild-type RAS, resulting in greater MAPK output and increased sensitivity to MEK inhibitors. ©2015 American Association for Cancer Research.

  17. Relationship between the high-risk HPV infection and the expression of oncogenes, anti-oncogenes in cervical dysplasia

    Institute of Scientific and Technical Information of China (English)

    Li-Ping Shi; Xiu-Jie Sheng

    2017-01-01

    Objective:To study the relationship between the infection of high-risk HPV in cervical precancerous lesion and the expression of oncogene, anti-oncogene.Methods:218 cases ofcervical intraepithelial neoplasia patients in our hospital during May 2014–May 2016 were chosed and divided into high-risk HPV group (n=107), low-risk HPV group (n=111) according to cervical tissue HPV test; another 100 cases of patients received cervical biopsy and confirmed as benign lesions were enrolled in the control group. RT-PCR method was used to detect the mRNA expression of proto-oncogene and anti-oncogene in three groups, Western-blot method was used to detect the protein expression of Sox-2 and Wnt/β-catenin signal pathway.Results: mRNA expression of oncogene DEK, Bmi-1, c-fos, K-ras, Prdx4 in high-risk HPV group were higher than low-risk HPV group and control group (P<0.05); mRNA expression of anti-oncogene P27, P16, DAPK, PTEN, eIF4E3 in high-risk HPV group were lower than low-risk HPV group and control group (P<0.05); expression of Sox-2 and Wnt/β-catenin signaling pathway protein Sox-2,β-catenin, wnt-1, wnt-3a in high-risk HPV group were higher than low-risk HPV group and control group (P<0.05).Conclusions:High-risk HPV infection can increase the expression of oncogenes and reduce the expression of anti-oncogenes in cervical dysplasia tissues on Sox-2- and Wnt/β-catenin signaling pathway manners.

  18. Radiosensitivity of tumor cells. Oncogenes and apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Peltenburg, L. T. C. [Leiden Univ., Leiden (Netherlands). Dept. of Clinical Oncology

    2000-12-01

    The success of treatment of cancer patients by radiotherapy largely depends on tumor radiosensitivity. Several molecular factors that determine the sensitivity of tumor cells to ionizing radiation have been identified during the last couple of years. Some of these factors are known as oncogenes and tumor suppressor genes. This review focuses on the influence of some of these molecular factors on a major determinant of radiosensitivity: i. e. programmed cell death or apoptosis. The crucial molecular step in ionizing radiation-induced apoptosis is the release of mitochondrial cytochrome c into the cell's cytosol. The ways the tumor suppressor protein p53, as well as the oncogenes ras and raf, c-myc and Bcl-2 can influence this process at different stages are presented. As will be discussed, the result of activation of an oncoprotein on tumor radiosensitivity depends on its mechanism of action and on the presence of other (oncogenic) factors, since complex interactions among many molecular factors determine the delicate balance between cell proliferation and cell death. The ongoing identification and characterization of factors influencing apoptosis will eventually make it possible to predict tumor radiosensitivity and thereby improve cancer treatment.

  19. The RNA helicase/transcriptional co-regulator, p68 (DDX5), stimulates expression of oncogenic protein kinase, Polo-like kinase-1 (PLK1), and is associated with elevated PLK1 levels in human breast cancers

    Science.gov (United States)

    Iyer, R Sumanth; Nicol, Samantha M; Quinlan, Philip R; Thompson, Alastair M; Meek, David W; Fuller-Pace, Frances V

    2014-01-01

    p68 (DDX5) acts both as an ATP-dependent RNA helicase and as a transcriptional co-activator of several cancer-associated transcription factors, including the p53 tumor suppressor. p68 is aberrantly expressed in a high proportion of cancers, but the oncogenic drive for, or the consequences of, these expression changes remain unclear. Here we show that elevated p68 expression in a cohort of human breast cancers is associated significantly with elevated levels of the oncogenic protein kinase, Polo-like kinase-1 (PLK1). Patients expressing detectable levels of both p68 and PLK1 have a poor prognosis, but only if they also have mutation in the TP53 gene (encoding p53), suggesting that p68 can regulate PLK1 levels in a manner that is suppressed by p53. In support of this hypothesis, we show that p68 stimulates expression from the PLK1 promoter, and that silencing of endogenous p68 expression downregulates endogenous PLK1 gene expression. In the absence of functional p53, p68 stimulates the expression of PLK1 both at basal levels and in response to the clinically relevant drug, etoposide. In keeping with a role as a transcriptional activator/co-activator, chromatin immuno-precipitation analysis shows that p68 is associated with the PLK1 promoter, irrespective of the p53 status. However, its recruitment is stimulated by etoposide in cells lacking p53, suggesting that p53 can oppose association of p68 with the PLK1 promoter. These data provide a model in which p68 and p53 interplay regulates PLK1 expression, and which describes the behavior of these molecules, and the outcome of their interaction, in human breast cancer. PMID:24626184

  20. Cooperative antiproliferative effect of coordinated ectopic expression of DLC1 tumor suppressor protein and silencing of MYC oncogene expression in liver cancer cells: Therapeutic implications

    Science.gov (United States)

    Yang, Xuyu; Zhou, Xiaoling; Tone, Paul; Durkin, Marian E.; Popescu, Nicholas C.

    2016-01-01

    Human hepatocellular carcinoma (HCC) is one of the most common types of cancer and has a very poor prognosis; thus, the development of effective therapies for the treatment of advanced HCC is of high clinical priority. In the present study, the anti-oncogenic effect of combined knockdown of c-Myc expression and ectopic restoration of deleted in liver cancer 1 (DLC1) expression was investigated in human liver cancer cells. Expression of c-Myc in human HCC cells was knocked down by stable transfection with a Myc-specific short hairpin (sh) RNA vector. DLC1 expression in Huh7 cells was restored by adenovirus transduction, and the effects of DLC1 expression and c-Myc knockdown on Ras homolog gene family, member A (RhoA) levels, cell proliferation, soft agar colony formation and cell invasion were measured. Downregulation of c-Myc or re-expression of DLC1 led to a marked reduction in RhoA levels, which was associated with decreases in cell proliferation, soft agar colony formation and invasiveness; this inhibitory effect was augmented with a combination of DLC1 transduction and c-Myc suppression. To determine whether liver cell-specific delivery of DLC1 was able to enhance the inhibitory effect of c-Myc knockdown on tumor growth in vivo, DLC1 vector DNA complexed with galactosylated polyethylene glycol-linear polyethyleneimine was administered by tail vein injection to mice bearing subcutaneous xenografts of Huh7 cells transfected with shMyc or control shRNA. A cooperative inhibitory effect of DLC1 expression and c-Myc knockdown on the growth of Huh7-derived tumors was observed, suggesting that targeted liver cell delivery of DLC1 and c-Myc shRNA may serve as a possible gene therapy modality for the treatment of human HCC. PMID:27446476

  1. HspB1, HspB5 and HspB4 in Human Cancers: Potent Oncogenic Role of Some of Their Client Proteins

    Directory of Open Access Journals (Sweden)

    André-Patrick Arrigo

    2014-02-01

    Full Text Available Human small heat shock proteins are molecular chaperones that regulate fundamental cellular processes in normal unstressed cells as well as in many cancer cells where they are over-expressed. These proteins are characterized by cell physiology dependent changes in their oligomerization and phosphorylation status. These structural changes allow them to interact with many different client proteins that subsequently display modified activity and/or half-life. Nowdays, the protein interactomes of small Hsps are under intense investigations and will represent, when completed, key parameters to elaborate therapeutic strategies aimed at modulating the functions of these chaperones. Here, we have analyzed the potential pro-cancerous roles of several client proteins that have been described so far to interact with HspB1 (Hsp27 and its close members HspB5 (αB-crystallin and HspB4 (αA-crystallin.

  2. All Mammalian Hedgehog Proteins Interact with Cell Adhesion Molecule, Down-regulated by Oncogenes (CDO) and Brother of CDO (BOC) in a Conserved Manner*

    OpenAIRE

    Kavran, Jennifer M.; Ward, Matthew D.; Oladosu, Oyindamola O.; Mulepati, Sabin; Leahy, Daniel J.

    2010-01-01

    Hedgehog (Hh) signaling proteins stimulate cell proliferation, differentiation, and tissue patterning at multiple points in animal development. A single Hh homolog is present in Drosophila, but three Hh homologs, Sonic Hh, Indian Hh, and Desert Hh, are present in mammals. Distribution, movement, and reception of Hh signals are tightly regulated, and abnormal Hh signaling is associated with developmental defects and cancer. In addition to the integral membrane proteins Patched and Smoothened, ...

  3. Hyaluronic acid-fabricated nanogold delivery of the inhibitor of apoptosis protein-2 siRNAs inhibits benzo[a]pyrene-induced oncogenic properties of lung cancer A549 cells

    Science.gov (United States)

    Lin, Chung-Ming; Kao, Wei-Chien; Yeh, Chun-An; Chen, Hui-Jye; Lin, Shinn-Zong; Hsieh, Hsien-Hsu; Sun, Wei-Shen; Chang, Chih-Hsuan; Hung, Huey-Shan

    2015-03-01

    Benzo[a]pyrene (BaP), a component of cooking oil fumes (COF), promotes lung cancer cell proliferation and survival via the induction of inhibitor of apoptosis protein-2 (IAP-2) proteins. Thus knockdown of IAP-2 would be a promising way to battle against lung cancer caused by COF. Functionalized gold nanoparticle (AuNP) is an effective delivery system for bio-active materials. Here, biocompatible hyaluronic acid (HA) was fabricated into nanoparticles to increase the target specificity by binding to CD44-over-expressed cancer cells. IAP-2-specific small-interfering RNA (siRNAs) or fluorescein isothiocyanate (FITC) were then incorporated into AuNP-HA. Conjugation of IAP-2 siRNA into AuNPs-HA was verified by the UV-vis spectrometer and Fourier transform infrared spectrometer. Further studies showed that AuNP-HA/FITC were effectively taken up by A549 cells through CD44-mediated endocytosis. Incubation of BaP-challenged cells with AuNP-HA-IAP-2 siRNAs silenced the expression of IAP-2, decreased cell proliferation and triggered pronounced cell apoptosis by the decrease in Bcl-2 protein and the increase in Bax protein as well as the active form of caspases-3. The BaP-elicited cell migration and enzymatic activity of the secreted matrix metalloproteinase-2 were also substantially suppressed by treatment with AuNP-HA-IAP-2 siRNAs. These results indicated that IAP-2 siRNAs can be efficiently delivered into A549 cells by functionalized AuNP-HA to repress the IAP-2 expression and BaP-induced oncogenic events, suggesting the potential therapeutic application of IAP-2 siRNA or other siRNA-conjugated AuNP-HA composites to COF-induced lung cancer and other gene-caused diseases in the future.

  4. Oncogenic cancer/testis antigens

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Andersen, Mads H; Ditzel, Henrik J

    2015-01-01

    Recent developments have set the stage for immunotherapy as a supplement to conventional cancer treatment. Consequently, a significant effort is required to further improve efficacy and specificity, particularly the identification of optimal therapeutic targets for clinical testing. Cancer....../testis antigens are immunogenic, highly cancer-specific, and frequently expressed in various types of cancer, which make them promising candidate targets for cancer immunotherapy, including cancer vaccination and adoptive T-cell transfer with chimeric T-cell receptors. Our current understanding of tumor...... immunology and immune escape suggests that targeting oncogenic antigens may be beneficial, meaning that identification of cancer/testis antigens with oncogenic properties is of high priority. Recent work from our lab and others provide evidence that many cancer/testis antigens, in fact, have oncogenic...

  5. Co-localization of the oncogenic transcription factor MYCN and the DNA methyl binding protein MeCP2 at genomic sites in neuroblastoma.

    Directory of Open Access Journals (Sweden)

    Derek M Murphy

    Full Text Available BACKGROUND: MYCN is a transcription factor that is expressed during the development of the neural crest and its dysregulation plays a major role in the pathogenesis of pediatric cancers such as neuroblastoma, medulloblastoma and rhabdomyosarcoma. MeCP2 is a CpG methyl binding protein which has been associated with a number of cancers and developmental disorders, particularly Rett syndrome. METHODS AND FINDINGS: Using an integrative global genomics approach involving chromatin immunoprecipitation applied to microarrays, we have determined that MYCN and MeCP2 co-localize to gene promoter regions, as well as inter/intragenic sites, within the neuroblastoma genome (MYCN amplified Kelly cells at high frequency (70.2% of MYCN sites were also positive for MeCP2. Intriguingly, the frequency of co-localization was significantly less at promoter regions exhibiting substantial hypermethylation (8.7%, as determined by methylated DNA immunoprecipitation (MeDIP applied to the same microarrays. Co-immunoprecipitation of MYCN using an anti-MeCP2 antibody indicated that a MYCN/MeCP2 interaction occurs at protein level. mRNA expression profiling revealed that the median expression of genes with promoters bound by MYCN was significantly higher than for genes bound by MeCP2, and that genes bound by both proteins had intermediate expression. Pathway analysis was carried out for genes bound by MYCN, MeCP2 or MYCN/MeCP2, revealing higher order functions. CONCLUSIONS: Our results indicate that MYCN and MeCP2 protein interact and co-localize to similar genomic sites at very high frequency, and that the patterns of binding of these proteins can be associated with significant differences in transcriptional activity. Although it is not yet known if this interaction contributes to neuroblastoma disease pathogenesis, it is intriguing that the interaction occurs at the promoter regions of several genes important for the development of neuroblastoma, including ALK, AURKA and

  6. Molecular Docking Explains Atomic Interaction between Plant-originated Ligands and Oncogenic E7 Protein of High Risk Human Papillomavirus Type 16

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    Satish Kumar

    2014-12-01

    Full Text Available Cervical cancer caused by Human papillomavirus (HPV is one of the leading causes of cancer mortality in women worldwide, particularly in the developing countries. In the last few decades, various compounds from plant origin such as Curcumin, Epigallocatechin gallate (EGCG, Jaceosidin, Resveratrol etc. have been used as anti cancer therapeutic agents. Different studies have shown these plant-originated compounds are able to suppress HPV infection. The E6 and E7 oncoproteins of high-risk HPV play a key role in HPV related cancers. In this study, we explored these ligands from plants origin against E7 oncoprotein of high risk HPV 16, which is known to inactivate tumor suppressor pRb protein. A robust homology model of HPV 16 E7 was built to foresee the interaction mechanism of E7 oncoprotein with these ligands using structure-based drug designing approach. Docking studies demonstrate the interaction of these ligands with pRb binding site of E7 protein by residues Tyr52, Asn53, Val55, Phe57, Cys59, Ser63, Thr64, Thr72, Arg77, Glu80 and Asp81 and help restoration of pRb functioning. This in silico based atomic interaction between these ligands and E7 protein may assist in validating the plant-originated ligands as effective drugs against HPV.

  7. In Silico Analysis of Oncogenes for Renal Cancer

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    Sim-Hui Tee

    2012-01-01

    Full Text Available Computational tools and methods play a vital role in handling and analyzing a large volume of genomic data. In cancer research, in silico methods such as computational algorithm and protein databases are indispensable. In this paper, we adopted an in silico approach to analyze oncogenes that cause  renal cancer. Our objective is to identify and analyze the genes which are over expressed in the renal cancer tissues. The identification of oncogenes for renal cancer could provide directions and insights for molecular cancer treatment.

  8. Oncogenic extracellular vesicles in brain tumour progression

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    Esterina eD'Asti

    2012-07-01

    Full Text Available The brain is a frequent site of neoplastic growth, including both primary and metastatic tumours. The clinical intractability of many brain tumours and their distinct biology are implicitly linked to the unique microenvironment of the central nervous system (CNS and cellular interactions within. Among the most intriguing forms of cellular interactions is that mediated by membrane-derived extracellular vesicles (EVs. Their biogenesis (vesiculation and uptake by recipient cells serves as a unique mechanism of intercellular trafficking of complex biological messages including the exchange of molecules that cannot be released through classical secretory pathways, or that are prone to extracellular degradation. Tumour cells produce EVs containing molecular effectors of several cancer-related processes such as growth, invasion, drug resistance, angiogenesis, and coagulopathy. Notably, tumour-derived EVs (oncosomes also contain oncogenic proteins, transcripts, DNA and microRNA (miR. Uptake of this material may change properties of the recipient cells and impact the tumour microenvironment. Examples of transformation-related molecules found in the cargo of tumour-derived EVs include the oncogenic epidermal growth factor receptor (EGFRvIII, tumour suppressors (PTEN and oncomirs (miR-520g. It is postulated that EVs circulating in blood or cerebrospinal fluid (CSF of brain tumour patients may be used to decipher molecular features (mutations of the underlying malignancy, reflect responses to therapy or molecular subtypes of primary brain tumours (e.g. glioma or medulloblastoma. It is possible that metastases to the brain may also emit EVs with clinically relevant oncogenic signatures. Thus EVs emerge as a novel and functionally important vehicle of intercellular communication that can mediate multiple biological effects. In addition, they provide a unique platform to develop molecular biomarkers in brain malignancies.

  9. Oncogenes and RNA splicing of human tumor viruses.

    Science.gov (United States)

    Ajiro, Masahiko; Zheng, Zhi-Ming

    2014-09-01

    Approximately 10.8% of human cancers are associated with infection by an oncogenic virus. These viruses include human papillomavirus (HPV), Epstein-Barr virus (EBV), Merkel cell polyomavirus (MCV), human T-cell leukemia virus 1 (HTLV-1), Kaposi's sarcoma-associated herpesvirus (KSHV), hepatitis C virus (HCV) and hepatitis B virus (HBV). These oncogenic viruses, with the exception of HCV, require the host RNA splicing machinery in order to exercise their oncogenic activities, a strategy that allows the viruses to efficiently export and stabilize viral RNA and to produce spliced RNA isoforms from a bicistronic or polycistronic RNA transcript for efficient protein translation. Infection with a tumor virus affects the expression of host genes, including host RNA splicing factors, which play a key role in regulating viral RNA splicing of oncogene transcripts. A current prospective focus is to explore how alternative RNA splicing and the expression of viral oncogenes take place in a cell- or tissue-specific manner in virus-induced human carcinogenesis.

  10. Molecular Mechanisms of TNFR-associated Factor 6 (TRAF6) Utilization by the Oncogenic Viral Mimic of CD40, Latent Membrane Protein 1 (LMP1)*

    Science.gov (United States)

    Arcipowski, Kelly M.; Stunz, Laura L.; Graham, John P.; Kraus, Zachary J.; Bush, Tony J. Vanden; Bishop, Gail A.

    2011-01-01

    Latent membrane protein 1 (LMP1), encoded by Epstein-Barr virus, is required for EBV-mediated B cell transformation and plays a significant role in the development of posttransplant B cell lymphomas. LMP1 has also been implicated in exacerbation of autoimmune diseases such as systemic lupus erythematosus. LMP1 is a constitutively active functional mimic of the tumor necrosis factor receptor superfamily member CD40, utilizing tumor necrosis factor receptor-associated factor (TRAF) adaptor proteins to induce signaling. However, LMP1-mediated B cell activation is amplified and sustained compared with CD40. We have previously shown that LMP1 and CD40 use TRAFs 1, 2, 3, and 5 differently. TRAF6 is important for CD40 signaling, but the role of TRAF6 in LMP1 signaling in B cells is not clear. Although TRAF6 binds directly to CD40, TRAF6 interaction with LMP1 in B cells has not been characterized. Here we tested the hypothesis that TRAF6 is a critical regulator of LMP1 signaling in B cells, either as part of a receptor-associated complex and/or as a cytoplasmic adaptor protein. Using TRAF6-deficient B cells, we determined that TRAF6 was critical for LMP1-mediated B cell activation. Although CD40-mediated TRAF6-dependent signaling does not require the TRAF6 receptor-binding domain, we found that LMP1 signaling required the presence of this domain. Furthermore, TRAF6 was recruited to the LMP1 signaling complex via the TRAF1/2/3/5 binding site within the cytoplasmic domain of LMP1. PMID:21262968

  11. Human Thyroid Cancer-1 (TC-1 is a vertebrate specific oncogenic protein that protects against copper and pro-apoptotic genes in yeast

    Directory of Open Access Journals (Sweden)

    Natalie K. Jones

    2015-07-01

    Full Text Available The human Thyroid Cancer-1 (hTC-1 protein, also known as C8orf4 was initially identified as a gene that was up-regulated in human thyroid cancer. Here we show that hTC-1 is a peptide that prevents the effects of over-expressing Bax in yeast. Analysis of the 106 residues of hTC-1 in available protein databases revealed direct orthologues in jawed-vertebrates, including mammals, frogs, fish and sharks. No TC-1 orthologue was detected in lower organisms, including yeast. Here we show that TC-1 is a general pro-survival peptide since it prevents the growth- and cell death-inducing effects of copper in yeast. Human TC-1 also prevented the deleterious effects that occur due to the over-expression of a number of key pro-apoptotic peptides, including YCA1, YBH3, NUC1, and AIF1. Even though the protective effects were more pronounced with the over-expression of YBH3 and YCA1, hTC-1 could still protect yeast mutants lacking YBH3 and YCA1 from the effects of copper sulfate. This suggests that the protective effects of TC-1 are not limited to specific pathways or processes. Taken together, our results indicate that hTC-1 is a pro-survival protein that retains its function when heterologously expressed in yeast. Thus yeast is a useful model to characterize the potential roles in cell death and survival of cancer related genes.

  12. High-content image informatics of the structural nuclear protein NuMA parses trajectories for stem/progenitor cell lineages and oncogenic transformation.

    Science.gov (United States)

    Vega, Sebastián L; Liu, Er; Arvind, Varun; Bushman, Jared; Sung, Hak-Joon; Becker, Matthew L; Lelièvre, Sophie; Kohn, Joachim; Vidi, Pierre-Alexandre; Moghe, Prabhas V

    2017-02-01

    Stem and progenitor cells that exhibit significant regenerative potential and critical roles in cancer initiation and progression remain difficult to characterize. Cell fates are determined by reciprocal signaling between the cell microenvironment and the nucleus; hence parameters derived from nuclear remodeling are ideal candidates for stem/progenitor cell characterization. Here we applied high-content, single cell analysis of nuclear shape and organization to examine stem and progenitor cells destined to distinct differentiation endpoints, yet undistinguishable by conventional methods. Nuclear descriptors defined through image informatics classified mesenchymal stem cells poised to either adipogenic or osteogenic differentiation, and oligodendrocyte precursors isolated from different regions of the brain and destined to distinct astrocyte subtypes. Nuclear descriptors also revealed early changes in stem cells after chemical oncogenesis, allowing the identification of a class of cancer-mitigating biomaterials. To capture the metrology of nuclear changes, we developed a simple and quantitative "imaging-derived" parsing index, which reflects the dynamic evolution of the high-dimensional space of nuclear organizational features. A comparative analysis of parsing outcomes via either nuclear shape or textural metrics of the nuclear structural protein NuMA indicates the nuclear shape alone is a weak phenotypic predictor. In contrast, variations in the NuMA organization parsed emergent cell phenotypes and discerned emergent stages of stem cell transformation, supporting a prognosticating role for this protein in the outcomes of nuclear functions.

  13. The Epstein-Barr virus oncogene product, latent membrane protein 1, induces the downregulation of E-cadherin gene expression via activation of DNA methyltransferases

    Institute of Scientific and Technical Information of China (English)

    Chi-NeuTsai

    2005-01-01

    The latent membrane protein (LMP1) of Epstein-Barr virus (EBV) is expressed in EBV-associated nasopharyngeal carcinoma, which isnotoriously metastatic. Although it Is established that LMP1 represses E-cadherin expression and enhances the invasive ability of carcinoma cells, the mechanism underlying this repression remains to be elucidated. In this study, we demonstrate that LMP1 induces the expression and activity of the DNA methyltransferases 1, 3a, and 3b, using real-time reverse transcription-PCR and enzyme activity assay. This results in hypermethylation of the E-cadherin promoter and down-regulation of E-cadherin gene expression, as revealed by methylation-specific PCR, real-time reverse transcription-PeR and Western blotting data. The DNA methyltransferase inhibitor, 5'-Aza-2'dC, restores E-cadherin promoter activity and protein expression in LMPl-expressing cells, which in turn blocks cell migration ability, as demonstrated by the Transwell cell migration assay. Our findings suggest that LMP1 down-regulates E-cadherin gene expression and induces cell migration activity by using cellular DNA methylation machinery.

  14. Prediction of oncogenic interactions and cancer-related signaling networks based on network topology.

    Science.gov (United States)

    Acencio, Marcio Luis; Bovolenta, Luiz Augusto; Camilo, Esther; Lemke, Ney

    2013-01-01

    Cancer has been increasingly recognized as a systems biology disease since many investigators have demonstrated that this malignant phenotype emerges from abnormal protein-protein, regulatory and metabolic interactions induced by simultaneous structural and regulatory changes in multiple genes and pathways. Therefore, the identification of oncogenic interactions and cancer-related signaling networks is crucial for better understanding cancer. As experimental techniques for determining such interactions and signaling networks are labor-intensive and time-consuming, the development of a computational approach capable to accomplish this task would be of great value. For this purpose, we present here a novel computational approach based on network topology and machine learning capable to predict oncogenic interactions and extract relevant cancer-related signaling subnetworks from an integrated network of human genes interactions (INHGI). This approach, called graph2sig, is twofold: first, it assigns oncogenic scores to all interactions in the INHGI and then these oncogenic scores are used as edge weights to extract oncogenic signaling subnetworks from INHGI. Regarding the prediction of oncogenic interactions, we showed that graph2sig is able to recover 89% of known oncogenic interactions with a precision of 77%. Moreover, the interactions that received high oncogenic scores are enriched in genes for which mutations have been causally implicated in cancer. We also demonstrated that graph2sig is potentially useful in extracting oncogenic signaling subnetworks: more than 80% of constructed subnetworks contain more than 50% of original interactions in their corresponding oncogenic linear pathways present in the KEGG PATHWAY database. In addition, the potential oncogenic signaling subnetworks discovered by graph2sig are supported by experimental evidence. Taken together, these results suggest that graph2sig can be a useful tool for investigators involved in cancer research

  15. Prediction of oncogenic interactions and cancer-related signaling networks based on network topology.

    Directory of Open Access Journals (Sweden)

    Marcio Luis Acencio

    Full Text Available Cancer has been increasingly recognized as a systems biology disease since many investigators have demonstrated that this malignant phenotype emerges from abnormal protein-protein, regulatory and metabolic interactions induced by simultaneous structural and regulatory changes in multiple genes and pathways. Therefore, the identification of oncogenic interactions and cancer-related signaling networks is crucial for better understanding cancer. As experimental techniques for determining such interactions and signaling networks are labor-intensive and time-consuming, the development of a computational approach capable to accomplish this task would be of great value. For this purpose, we present here a novel computational approach based on network topology and machine learning capable to predict oncogenic interactions and extract relevant cancer-related signaling subnetworks from an integrated network of human genes interactions (INHGI. This approach, called graph2sig, is twofold: first, it assigns oncogenic scores to all interactions in the INHGI and then these oncogenic scores are used as edge weights to extract oncogenic signaling subnetworks from INHGI. Regarding the prediction of oncogenic interactions, we showed that graph2sig is able to recover 89% of known oncogenic interactions with a precision of 77%. Moreover, the interactions that received high oncogenic scores are enriched in genes for which mutations have been causally implicated in cancer. We also demonstrated that graph2sig is potentially useful in extracting oncogenic signaling subnetworks: more than 80% of constructed subnetworks contain more than 50% of original interactions in their corresponding oncogenic linear pathways present in the KEGG PATHWAY database. In addition, the potential oncogenic signaling subnetworks discovered by graph2sig are supported by experimental evidence. Taken together, these results suggest that graph2sig can be a useful tool for investigators involved

  16. GTPase domains of ras p21 oncogene protein and elongation factor Tu: analysis of three-dimensional structures, sequence families, and functional sites.

    Science.gov (United States)

    Valencia, A; Kjeldgaard, M; Pai, E F; Sander, C

    1991-06-15

    GTPase domains are functional and structural units employed as molecular switches in a variety of important cellular functions, such as growth control, protein biosynthesis, and membrane traffic. Amino acid sequences of more than 100 members of different subfamilies are known, but crystal structures of only mammalian ras p21 and bacterial elongation factor Tu have been determined. After optimal superposition of these remarkably similar structures, careful multiple sequence alignment, and calculation of residue-residue interactions, we analyzed the two subfamilies in terms of structural conservation, sequence conservation, and residue contact strength. There are three main results. (i) A structure-based alignment of p21 and elongation factor Tu. (ii) The definition of a common conserved structural core that may be useful as the basis of model building by homology of the three-dimensional structure of any GTPase domain. (iii) Identification of sequence regions, other than the effector loop and the nucleotide binding site, that may be involved in the functional cycle: they are loop L4, known to change conformation after GTP hydrolysis; helix alpha 2, especially Arg-73 and Met-67 in ras p21; loops L8 and L10, including ras p21 Arg-123, Lys-147, and Leu-120; and residues located spatially near the N and C termini. These regions are candidate sites for interaction either with the GTP/GDP exchange factor, with a GTPase-affected function, or with a molecule delivered to a destination site with the aid of the GTPase domain.

  17. The oncogenic fusion protein RUNX1-CBFA2T1 supports proliferation and inhibits senescence in t(8;21)-positive leukaemic cells

    Science.gov (United States)

    Martinez, Natalia; Drescher, Bettina; Riehle, Heidemarie; Cullmann, Claire; Vornlocher, Hans-Peter; Ganser, Arnold; Heil, Gerhard; Nordheim, Alfred; Krauter, Jürgen; Heidenreich, Olaf

    2004-01-01

    Background The fusion protein RUNX1-CBFA2T1 associated with t(8;21)-positive acute myeloid leukaemia is a potent inhibitor of haematopoetic differentiation. The role of RUNX1-CBFA2T1 in leukaemic cell proliferation is less clear. We examined the consequences of siRNA-mediated RUNX1-CBFA2T1 depletion regarding proliferation and clonogenicity of t(8;21)-positive cell lines. Methods The t(8;21)-positive cell line Kasumi-1 was electroporated with RUNX1-CBFA2T1 or control siRNAs followed by analysis of proliferation, colony formation, cell cycle distribution, apoptosis and senescence. Results Electroporation of Kasumi-1 cells with RUNX1-CBFA2T1 siRNAs, but not with control siRNAs, resulted in RUNX1-CBFA2T1 suppression which lasted for at least 5 days. A single electroporation with RUNX1-CBFA2T1 siRNA severely diminished the clonogenicity of Kasumi-1 cells. Prolonged RUNX1-CBFA2T1 depletion inhibited proliferation in suspension culture and G1-S transition during the cell cycle, diminished the number of apoptotic cells, but induced cellular senescence. The addition of haematopoetic growth factors could not rescue RUNX1-CBFA2T1-depleted cells from senescence, and could only partially restore their clonogenicity. Conclusions RUNX1-CBFA2T1 supports the proliferation and expansion of t(8;21)-positive leukaemic cells by preventing cellular senescence. These findings suggest a central role of RUNX1-CBFA2T1 in the maintenance of the leukaemia. Therefore, RUNX1-CBFA2T1 is a promising and leukaemia-specific target for molecularly defined therapeutic approaches. PMID:15298716

  18. The oncogenic fusion protein RUNX1-CBFA2T1 supports proliferation and inhibits senescence in t(8;21-positive leukaemic cells

    Directory of Open Access Journals (Sweden)

    Nordheim Alfred

    2004-08-01

    Full Text Available Abstract Background The fusion protein RUNX1-CBFA2T1 associated with t(8;21-positive acute myeloid leukaemia is a potent inhibitor of haematopoetic differentiation. The role of RUNX1-CBFA2T1 in leukaemic cell proliferation is less clear. We examined the consequences of siRNA-mediated RUNX1-CBFA2T1 depletion regarding proliferation and clonogenicity of t(8;21-positive cell lines. Methods The t(8;21-positive cell line Kasumi-1 was electroporated with RUNX1-CBFA2T1 or control siRNAs followed by analysis of proliferation, colony formation, cell cycle distribution, apoptosis and senescence. Results Electroporation of Kasumi-1 cells with RUNX1-CBFA2T1 siRNAs, but not with control siRNAs, resulted in RUNX1-CBFA2T1 suppression which lasted for at least 5 days. A single electroporation with RUNX1-CBFA2T1 siRNA severely diminished the clonogenicity of Kasumi-1 cells. Prolonged RUNX1-CBFA2T1 depletion inhibited proliferation in suspension culture and G1-S transition during the cell cycle, diminished the number of apoptotic cells, but induced cellular senescence. The addition of haematopoetic growth factors could not rescue RUNX1-CBFA2T1-depleted cells from senescence, and could only partially restore their clonogenicity. Conclusions RUNX1-CBFA2T1 supports the proliferation and expansion of t(8;21-positive leukaemic cells by preventing cellular senescence. These findings suggest a central role of RUNX1-CBFA2T1 in the maintenance of the leukaemia. Therefore, RUNX1-CBFA2T1 is a promising and leukaemia-specific target for molecularly defined therapeutic approaches.

  19. Phorbol Esters from Jatropha Meal Triggered Apoptosis, Activated PKC-δ, Caspase-3 Proteins and Down-Regulated the Proto-Oncogenes in MCF-7 and HeLa Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Syahida Ahmad

    2012-09-01

    Full Text Available Jatropha meal produced from the kernel of Jatropha curcas Linn. grown in Malaysia contains phorbol esters (PEs. The potential benefits of PEs present in the meal as anticancer agent are still not well understood. Hence, this study was conducted to evaluate the cytotoxic effects and mode of actions of PEs isolated from Jatropha meal against breast (MCF-7 and cervical (HeLa cancer cell lines. Isolated PEs inhibited cells proliferation in a dose-dependent manner of both MCF-7 and HeLa cell lines with the IC50 of 128.6 ± 2.51 and 133.0 ± 1.96 µg PMA equivalents/mL respectively, while the values for the phorbol 12-myristate 13-acetate (PMA as positive control were 114.7 ± 1.73 and 119.6 ± 3.73 µg/mL, respectively. Microscopic examination showed significant morphological changes that resemble apoptosis in both cell lines when treated with PEs and PMA at IC50 concentration after 24 h. Flow cytometry analysis and DNA fragmentation results confirmed the apoptosis induction of PEs and PMA in both cell lines. The PEs isolated from Jatropha meal activated the PKC-δ and down-regulated the proto-oncogenes (c-Myc, c-Fos and c-Jun. These changes probably led to the activation of Caspase-3 protein and apoptosis cell death occurred in MCF-7 and HeLa cell lines upon 24 h treatment with PEs and PMA. Phorbol esters of Jatropha meal were found to be promising as an alternative to replace the chemotherapeutic drugs for cancer therapy.

  20. Phorbol esters from Jatropha meal triggered apoptosis, activated PKC-δ, caspase-3 proteins and down-regulated the proto-oncogenes in MCF-7 and HeLa cancer cell lines.

    Science.gov (United States)

    Oskoueian, Ehsan; Abdullah, Norhani; Ahmad, Syahida

    2012-09-10

    Jatropha meal produced from the kernel of Jatropha curcas Linn. grown in Malaysia contains phorbol esters (PEs). The potential benefits of PEs present in the meal as anticancer agent are still not well understood. Hence, this study was conducted to evaluate the cytotoxic effects and mode of actions of PEs isolated from Jatropha meal against breast (MCF-7) and cervical (HeLa) cancer cell lines. Isolated PEs inhibited cells proliferation in a dose-dependent manner of both MCF-7 and HeLa cell lines with the IC₅₀ of 128.6 ± 2.51 and 133.0 ± 1.96 µg PMA equivalents/mL respectively, while the values for the phorbol 12-myristate 13-acetate (PMA) as positive control were 114.7 ± 1.73 and 119.6 ± 3.73 µg/mL, respectively. Microscopic examination showed significant morphological changes that resemble apoptosis in both cell lines when treated with PEs and PMA at IC₅₀ concentration after 24 h. Flow cytometry analysis and DNA fragmentation results confirmed the apoptosis induction of PEs and PMA in both cell lines. The PEs isolated from Jatropha meal activated the PKC-δ and down-regulated the proto-oncogenes (c-Myc, c-Fos and c-Jun). These changes probably led to the activation of Caspase-3 protein and apoptosis cell death occurred in MCF-7 and HeLa cell lines upon 24 h treatment with PEs and PMA. Phorbol esters of Jatropha meal were found to be promising as an alternative to replace the chemotherapeutic drugs for cancer therapy.

  1. Dana-Farber Cancer Institute: Discovery of Novel Oncogenes | Office of Cancer Genomics

    Science.gov (United States)

    Widespread recurrent copy number alterations are observed across the majority of human cancers, yet the specific targets of such amplified or deleted regions remain undefined. Here, the CTD2 Center at the Dana Farber Cancer Institute took a systematic approach using cDNA overexpression screening to identify and validate oncogenes residing in such amplified regions. In representative examples, these experiments have identified the adaptor proteins CRKL, GAB2, FRS2 and the TLOC and SKIL proteins as novel amplified oncogenes.

  2. Repression of transcription mediated at a thyroid hormone response element by the v-erb-A oncogene product

    DEFF Research Database (Denmark)

    Sap, J; Muñoz, A; Schmitt, J

    1989-01-01

    Several recent observations, such as the identification of the cellular homologue of the v-erb-A oncogene as a thyroid-hormone receptor, have strongly implicated nuclear oncogenes in transcriptional control mechanisms. The v-erb-A oncogene blocks the differentiation of erythroid cells, and changes......-erb-A protein negatively interferes with normal transcriptional-control mechanisms, and that amino-acid substitutions have altered its DNA-binding properties....

  3. Oncogenicity of human N-ras oncogene and proto-oncogene introduced into retroviral vectors

    Energy Technology Data Exchange (ETDEWEB)

    Souyri, M.; Vigon, I.; Charon, M.; Tambourin, P. (Hopital Cochin, Paris (France))

    1989-09-01

    The N-ras gene is the only member of the ras family which has never been naturally transduced into a retrovirus. In order to study the in vitro and in vivo oncogenicity of N-ras and to compare its pathogenicity to that of H-ras, the authors have inserted an activated or a normal form of human N-ras cDNA into a slightly modified Harvey murine sarcoma virus-derived vector in which the H-ras p21 coding region had been deleted. The resulting constructions were transfected into NIH 3T3 cells. The activated N-ras-containing construct (HSN) induced 10{sup 4} foci per {mu}g of DNA and was found to be as transforming as H-ras was. After infection of the transfected cells by either the ecotropic Moloney murine leukemia virus or the amphotropic 4070A helper viruses, rescued transforming viruses were injected into newborn mice. Both pseudotypes of HSN virus containing activated N-ras induced the typical Harvey disease with similar latency. However, they found that the virus which contained normal N-ras p21 (HSn) was also pathogenic and induced splenomegaly, lymphadenopathies, and sarcoma in mice after a latency of 3 to 7 weeks. In addition, Moloney murine leukemia virus pseudotypes of N-ras caused neurological disorders in 30% of the infected animals. These results differed markedly from those of previous experiments in which the authors had inserted the activated form of N-ras in the pSV(X) vector: the resulting SVN-ras virus was transforming on NIH 3T3 cells but was poorly oncogenic in vivo. Altogether, these data demonstrated unequivocally that N-ras is potentially as oncogenic as H-ras and that such oncogenic effect could depend on the vector environment.

  4. Synonymous codon changes in the oncogenes of the cottontail rabbit papillomavirus lead to increased oncogenicity and immunogenicity of the virus

    Science.gov (United States)

    Cladel, Nancy M.; Budgeon, Lynn R.; Hu, Jiafen; Balogh, Karla K.; Christensen, Neil D.

    2013-01-01

    Papillomaviruses use rare codons with respect to the host. The reasons for this are incompletely understood but among the hypotheses is the concept that rare codons result in low protein production and this allows the virus to escape immune surveillance. We changed rare codons in the oncogenes E6 and E7 of the cottontail rabbit papillomavirus to make them more mammalian-like and tested the mutant genomes in our in vivo animal model. While the amino acid sequences of the proteins remained unchanged, the oncogenic potential of some of the altered genomes increased dramatically. In addition, increased immunogenicity, as measured by spontaneous regression, was observed as the numbers of codon changes increased. This work suggests that codon usage may modify protein production in ways that influence disease outcome and that evaluation of synonymous codons should be included in the analysis of genetic variants of infectious agents and their association with disease. PMID:23433866

  5. c-Abl antagonizes the YAP oncogenic function.

    Science.gov (United States)

    Keshet, R; Adler, J; Ricardo Lax, I; Shanzer, M; Porat, Z; Reuven, N; Shaul, Y

    2015-06-01

    YES-associated protein (YAP) is a central transcription coactivator that functions as an oncogene in a number of experimental systems. However, under DNA damage, YAP activates pro-apoptotic genes in conjunction with p73. This program switching is mediated by c-Abl (Abelson murine leukemia viral oncogene) via phosphorylation of YAP at the Y357 residue (pY357). YAP as an oncogene coactivates the TEAD (transcriptional enhancer activator domain) family transcription factors. Here we asked whether c-Abl regulates the YAP-TEAD functional module. We found that DNA damage, through c-Abl activation, specifically depressed YAP-TEAD-induced transcription. Remarkably, c-Abl counteracts YAP-induced transformation by interfering with the YAP-TEAD transcriptional program. c-Abl induced TEAD1 phosphorylation, but the YAP-TEAD complex remained unaffected. In contrast, TEAD coactivation was compromised by phosphomimetic YAP Y357E mutation but not Y357F, as demonstrated at the level of reporter genes and endogenous TEAD target genes. Furthermore, YAP Y357E also severely compromised the role of YAP in cell transformation, migration, anchorage-independent growth, and epithelial-to-mesenchymal transition (EMT) in human mammary MCF10A cells. These results suggest that YAP pY357 lost TEAD transcription activation function. Our results demonstrate that YAP pY357 inactivates YAP oncogenic function and establish a role for YAP Y357 phosphorylation in cell-fate decision.

  6. Oncogenic pathways implicated in ovarian epithelial cancer.

    Science.gov (United States)

    Nicosia, Santo V; Bai, Wenlong; Cheng, Jin Q; Coppola, Domenico; Kruk, Patricia A

    2003-08-01

    Characterization of intracellular signaling pathways should lead to a better understanding of ovarian epithelial carcinogenesis and provide an opportunity to interfere with signal transduction targets involved in ovarian tumor cell growth, survival, and progression. Challenges toward such an effort are significant because many of these signals are part of cascades within an intricate and likely redundant intracellular signaling network (Fig.1). For instance, a given signal may activate a dual intracellular pathway (ie, MEK1-MAPK and PI3K/Akt required for fibronectin-dependent activation of matrix metalloproteinase 9). A single pathway also may transduce more than one biologic or oncogenic signal (ie, PI3K signaling in epithelial and endothelial cell growth and sprouting of neovessels). Despite these challenges, evidence for therapeutic targeting of signal transduction pathways is accumulating in human cancer. For instance, the EGF-specific tyrosine kinase inhibitor ZD 1839 (Iressa) may have a beneficial therapeutic effect on ovarian epithelial cancer. Therapy of this cancer may include inhibitors of PI kinase (quercetin), ezrin and PIP kinase (genistein). The G protein-coupled family of receptors, including LPA, also is an attractive target to drugs, although their frequent pleiotropic functions may be at times toxic and lack specificity. Because of the lack of notable toxicity, PI3K/Akt pathway inhibitors such as FTIs are a promising targeted therapy of ovarian epithelial cancer. Increasing insight into the oncogenic pathways involved in ovarian epithelial cancer also is helping clinicians to understand better the phenomenon of chemoresistance in this malignancy. Oncogenic activation of gamma-synuclein promotes cell survival and provides resistance to paclitaxel, but such a resistance is partially overcome by an MEK inhibitor that suppresses ERK activity. Ovarian epithelial cancer is a complex group of neoplasms with an overall poor prognosis. Comprehension of

  7. Correlation and differences in proto oncogene protein of patients with OLK and OSCC%OLK患者与OSCC癌患者的原癌基因蛋白差异及相关性研究

    Institute of Scientific and Technical Information of China (English)

    李崴嵬; 魏琦玲; 杨金晖; 佟静; 崔秋萍

    2015-01-01

    目的:探讨原癌基因蛋白在口腔鳞状细胞癌( oral squamous cell carcinoma,OSCC)及口腔白斑中( oral leukoplakia,OLK)的意义。方法选取唐山工人医院口腔科已确诊为口腔白斑的患者40例作为OLK组,确诊为口腔鳞状细胞癌患者40例作为OSCC组,同时期体检正常志愿者40例作为对照组,取病变组织、正常口腔粘膜作为样本,研磨后取上清液,采用酶联免疫法检测3组研究对象样本中MDM2蛋白,p53蛋白,Ki-67蛋白的含量情况,并分析3者的相关性。结果3组间MDM2、p53表达水平比较均为OSCC组>OLK组>对照组;3组间Ki-67表达水平比较,OSCC组>OLK组>对照组(P<0.05);MDM2,p53,Ki-67在口腔白斑及口腔鳞状细胞癌中表达呈正相关(P<0.05),在正常粘膜中表达无相关。结论口腔白斑发展成为口腔鳞状细胞癌与MDM2,p53,Ki-67的高表达有关,MDM2、p53、Ki-673者之间呈正相关。%Objective To analyse the significance of proto oncogene protein in oral squamous cell carcinoma and oral leukoplakia.Methods 40 patients who were diagnosed with oral leukoplakia (OLK),40 patients who were diagnosed with oral squamous cell carcinoma(OSCC),and at the same time, 40 healthy volunteers as control group were collected.the lesions and normal oral mucosa were taken as samples, left supernatant after grinding, MDM2 protein, p53 protein and Ki-67 protein were detected by ELISA in three groups,and analyse the correlation between three groups.Results Among three groups,MDM2, p53 expression:OSCC group>OLK group>control group (POLK group>control group (P<0.05).MDM2, p53, Ki-67 expression had a positive correlation in OSCC group and OLK group (P<0.05), but there was no obvious correlation in control group.Conclusion When oral leukoplakia developes into oral squamous cell carcinoma, MDM2, p53, Ki-67 shows high expression, and there is a positive correlation between MDM2, p53, Ki-67.

  8. 40 CFR 798.3300 - Oncogenicity.

    Science.gov (United States)

    2010-07-01

    ... Species of Experimental Animals for Inhalation Carcinogenicity Studies” Paper presented at Conference on...) HEALTH EFFECTS TESTING GUIDELINES Chronic Exposure § 798.3300 Oncogenicity. (a) Purpose. The objective of a long-term oncogenicity study is to observe test animals for a major portion of their life span for...

  9. High Risk Alpha Papillomavirus Oncogenes Impair the Homologous Recombination Pathway.

    Science.gov (United States)

    Wallace, Nicholas A; Khanal, Sujita; Robinson, Kristin L; Wendel, Sebastian O; Messer, Joshua J; Galloway, Denise A

    2017-08-02

    Persistent high risk genus α human papillomavirus (HPV) infections cause nearly every cervical carcinoma and a subset of tumors in the oropharyngeal tract. During the decades required for HPV-associated tumorigenesis, the cellular genome becomes significantly destabilized. Our analysis of cervical tumors from 4 separate data sets found a significant upregulation of the homologous recombination (HR) pathway genes. The increased abundance of HR proteins can be replicated in primary cells by expression of the two HPV oncogenes (E6 and E7) required for HPV-associated transformation. HPV E6 and E7 also enhanced the ability of HR proteins to form repair foci, yet both E6 and E7 reduce the ability of the HR pathway to complete double strand break (DSB) repair by about 50%. The HPV oncogenes hinder HR by allowing the process to begin at points in the cell cycle when the lack of a sister chromatid to serve as a homologous template prevents completion of the repair. Further, HPV E6 attenuates repair by causing RAD51 to be mislocalized away from both transient and persistent DSBs, while HPV E7 is only capable of impairing RAD51 localization to transient lesions. Finally, we show that the inability to robustly repair DSBs causes some of these lesions to be more persistent, a phenotype that correlates with increased integration of episomal DNA. Together these data support our hypothesis that HPV oncogenes contribute to the genomic instability observed in HPV-associated malignancies by attenuating the repair of damaged DNA.IMPORTANCE: This work expands the understanding of HPV biology, establishing a direct role for both HPV E6 and E7 in the destabilization of the host genome by blocking the homologous repair of DSBs. To our knowledge, this is the first time that both viral oncogenes were shown to disrupt this DSB repair pathway. We show that HPV E6 and E7 allow HR to initiate at an inappropriate part of the cell cycle. The mislocalization of RAD51 away from DSBs in cells

  10. Malignant transformation of diploid human fibroblasts by transfection of oncogenes

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.J.

    1992-01-01

    This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy.

  11. Tumour microvesicles contain retrotransposon elements and amplified oncogene sequences

    Science.gov (United States)

    Balaj, Leonora; Lessard, Ryan; Dai, Lixin; Cho, Yoon-Jae; Pomeroy, Scott L.; Breakefield, Xandra O.; Skog, Johan

    2011-01-01

    Tumour cells release an abundance of microvesicles containing a selected set of proteins and RNAs. Here, we show that tumour microvesicles also carry DNA, which reflects the genetic status of the tumour, including amplification of the oncogene c-Myc. We also find amplified c-Myc in serum microvesicles from tumour-bearing mice. Further, we find remarkably high levels of retrotransposon RNA transcripts, especially for some human endogenous retroviruses, such as LINE-1 and Alu retrotransposon elements, in tumour microvesicles and these transposable elements could be transferred to normal cells. These findings expand the nucleic acid content of tumour microvesicles to include: elevated levels of specific coding and non-coding RNA and DNA, mutated and amplified oncogene sequences and transposable elements. Thus, tumour microvesicles contain a repertoire of genetic information available for horizontal gene transfer and potential use as blood biomarkers for cancer. PMID:21285958

  12. Pharmacological strategies to target oncogenic KRAS signaling in pancreatic cancer.

    Science.gov (United States)

    Chuang, Hsiao-Ching; Huang, Po-Hsien; Kulp, Samuel K; Chen, Ching-Shih

    2017-03-01

    The clear importance of mutated KRAS as a therapeutic target has driven the investigation of multiple approaches to inhibit oncogenic KRAS signaling at different molecular levels. However, no KRAS-targeted therapy has reached the clinic to date, which underlies the intrinsic difficulty in developing effective, direct inhibitors of KRAS. Thus, this article provides an overview of the history and recent progress in the development of pharmacological strategies to target oncogenic KRAS with small molecule agents. Mechanistically, these KRAS-targeted agents can be classified into the following four categories. (1) Small-molecule RAS-binding ligands that prevent RAS activation by binding within or outside the nucleotide-binding motif. (2) Inhibitors of KRAS membrane anchorage. (3) Inhibitors that bind to RAS-binding domains of RAS-effector proteins. (4) Inhibitors of KRAS expression. The advantage and limitation of each type of these anti-KRAS agents are discussed.

  13. Oncogenic BRAF regulates melanoma proliferation through the lineage specific factor MITF.

    Directory of Open Access Journals (Sweden)

    Claudia Wellbrock

    Full Text Available The Microphthalmia-associated transcription factor (MITF is an important regulator of cell-type specific functions in melanocytic cells. MITF is essential for the survival of pigmented cells, but whereas high levels of MITF drive melanocyte differentiation, lower levels are required to permit proliferation and survival of melanoma cells. MITF is phosphorylated by ERK, and this stimulates its activation, but also targets it for degradation through the ubiquitin-proteosome pathway, coupling MITF degradation to its activation. We have previously shown that because ERK is hyper-activated in melanoma cells in which BRAF is mutated, the MITF protein is constitutively down-regulated. Here we describe another intriguing aspect of MITF regulation by oncogenic BRAF in melanoma cells. We show oncogenic BRAF up-regulates MITF transcription through ERK and the transcription factor BRN2 (N-Oct3. In contrast, we show that in melanocytes this pathway does not exist because BRN2 is not expressed, demonstrating that MITF regulation is a newly acquired function of oncogenic BRAF that is not performed by the wild-type protein. Critically, in melanoma cells MITF is required downstream of oncogenic BRAF because it regulates expression of key cell cycle regulatory proteins such as CDK2 and CDK4. Wild-type BRAF does not regulate this pathway in melanocytes. Thus, we show that oncogenic BRAF exerts exquisite control over MITF on two levels. It downregulates the protein by stimulating its degradation, but then counteracts this by increasing transcription through BRN2. Our data suggest that oncogenic BRAF plays a critical role in regulating MITF expression to ensure that its protein levels are compatible with proliferation and survival of melanoma cells. We propose that its ability to appropriate the regulation of this critical factor explains in part why BRAF is such a potent oncogene in melanoma.

  14. Alterations in metastatic properties of hepatocellular carcinoma cell following H-ras oncogene transfection

    Institute of Scientific and Technical Information of China (English)

    Qing Wang; Zhi Ying Lin; Xiao Li Feng

    2001-01-01

    AIM To demonstrate the relationship betweenH-ras oncogene and hepatocellular carcinoma(HCC) metastasis.METHODS Activated H-ras oncogene wastransfected into SMMC 7721, a cell line derivedfrom human HCC, by calcium phosphatetransfection method. Some metastasis-relatedparameters were detected in vitro, includingadhesion assay, migration assay, expression ofcollagenase ⅣV (c ⅣV ase) and epidermal growthfactor receptor (EGFR).RESULTS The abilities of H-ras-transfected cellclones in adhesion to laminin (LN) or fibronectin(FN), migration, c Ⅳ ase secretion increasedmarkedly, and the expression of EGFR elevatedmoderately. More importantly, these alterationswere consistent positively with the expressionof p21, the protein product of H-ras oncogene.CONCLUSION H-ras oncogene could inducethe metastatic phenotype of HCC cell in vitro toraise its metastatic potential.

  15. Analysis of acquired resistance to cis-diamminedichloroplatinum(II) in oncogene transfected SHOK cells

    Energy Technology Data Exchange (ETDEWEB)

    Kinashi, Yuko; Masunaga, Shinichiro; Suzuki, Minoru; Ono, Koji; Akaboshi, Mitsuhiko [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Watanabe, Masami

    1998-02-01

    SHOK (Syrian hamster Osaka-Kanazawa) cells were transfected with activated oncogenes (v-mos, c-myc, N-ras, H-ras, K-ras). These oncogene transfected cells were treated with {sup 195m}Pt-cis-diamminedichloroplatinum(II) (CDDP). Clonogenic cell survival assay showed that oncogene-transfected cells exhibited a 1.3-4.8 fold increases resistance to cisplatin compared to the parental SHOK cells. The CDDP concentration binding to DNA, RNA and protein were measured by counting the {sup 195m}Pt-radioactivity. The CDDP uptake was decreased in these oncogene transfected cells. The CDDP uptake in DNA of H-ras transfected cells decreased faster than control SHOK cells. (author)

  16. Human gene control by vital oncogenes: revisiting a theoretical model and its implications for targeted cancer therapy.

    Science.gov (United States)

    Willis, Rudolph E

    2012-01-01

    An important assumption of our current understanding of the mechanisms of carcinogenesis has been the belief that clarification of the cancer process would inevitably reveal some of the crucial mechanisms of normal human gene regulation. Since the momentous work of Bishop and Varmus, both the molecular and the biochemical processes underlying the events in the development of cancer have become increasingly clear. The identification of cellular signaling pathways and the role of protein kinases in the events leading to gene activation have been critical to our understanding not only of normal cellular gene control mechanisms, but also have clarified some of the important molecular and biochemical events occurring within a cancer cell. We now know that oncogenes are dysfunctional proto-oncogenes and that dysfunctional tumor suppressor genes contribute to the cancer process. Furthermore, Weinstein and others have hypothesized the phenomenon of oncogene addiction as a distinct characteristic of the malignant cell. It can be assumed that cancer cells, indeed, become dependent on such vital oncogenes. The products of these vital oncogenes, such as c-myc, may well be the Achilles heel by which targeted molecular therapy may lead to truly personalized cancer therapy. The remaining problem is the need to introduce relevant molecular diagnostic tests such as genome microarray analysis and proteomic methods, especially protein kinase identification arrays, for each individual patient. Genome wide association studies on cancers with gene analysis of single nucleotide and other mutations in functional proto-oncogenes will, hopefully, identify dysfunctional proto-oncogenes and allow the development of more specific targeted drugs directed against the protein products of these vital oncogenes. In 1984 Willis proposed a molecular and biochemical model for eukaryotic gene regulation suggesting how proto-oncogenes might function within the normal cell. That model predicted the

  17. Amplification of cellular oncogenes in solid tumors

    Directory of Open Access Journals (Sweden)

    Ozkan Bagci

    2015-01-01

    Full Text Available The term gene amplification refers to an increase in copy number of a gene. Upregulation of gene expression through amplification is a general mechanism to increase gene dosage. Oncogene amplifications have been shown in solid human cancers and they are often associated with progression of cancer. Defining oncogene amplification is useful since it is used as a prognostic marker in clinical oncology nowadays, especially v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (HER2 targeted agents are used in breast cancer patients with high level of HER2 overexpression as a therapeutic approach. However, patients without HER2 overexpression do not appear to benefit from these agents. We concluded that determination of oncogene amplification in solid tumors is an important factor in treatment of human cancers with many unknowns. We have referred to PubMed and some databases to prepare this article.

  18. LEO1 is regulated by PRL-3 and mediates its oncogenic properties in acute myelogenous leukemia.

    Science.gov (United States)

    Chong, Phyllis S Y; Zhou, Jianbiao; Cheong, Lip-Lee; Liu, Shaw-Cheng; Qian, Jingru; Guo, Tiannan; Sze, Siu Kwan; Zeng, Qi; Chng, Wee Joo

    2014-06-01

    PRL-3, an oncogenic dual-specificity phosphatase, is overexpressed in 50% of acute myelogenous leukemia (AML) and associated with poor survival. We found that stable expression of PRL-3 confers cytokine independence and growth advantage of AML cells. However, how PRL-3 mediates these functions in AML is not known. To comprehensively screen for PRL3-regulated proteins in AML, we performed SILAC-based quantitative proteomics analysis and discovered 398 significantly perturbed proteins after PRL-3 overexpression. We show that Leo1, a component of RNA polymerase II-associated factor (PAF) complex, is a novel and important mediator of PRL-3 oncogenic activities in AML. We described a novel mechanism where elevated PRL-3 protein increases JMJD2C histone demethylase occupancy on Leo1 promoter, thereby reducing the H3K9me3 repressive signals and promoting Leo1 gene expression. Furthermore, PRL-3 and Leo1 levels were positively associated in AML patient samples (N=24; PPRL-3 oncogenic phenotypes in AML. Loss of Leo1 leads to destabilization of the PAF complex and downregulation of SOX2 and SOX4, potent oncogenes in myeloid transformation. In conclusion, we identify an important and novel mechanism by which PRL-3 mediates its oncogenic function in AML.

  19. Regulation of Proto-Oncogenic Dbl by Chaperone-Controlled, Ubiquitin-Mediated Degradation▿

    OpenAIRE

    Kamynina, Elena; Kauppinen, Krista; Duan, Faping; Muakkassa, Nora; Manor, Danny

    2006-01-01

    The dbl proto-oncogene product is a prototype of a growing family of guanine nucleotide exchange factors (GEFs) that stimulate the activation of small GTP-binding proteins from the Rho family. Mutations that result in the loss of proto-Dbl's amino terminus produce a variant with constitutive GEF activity and high oncogenic potential. Here, we show that proto-Dbl is a short-lived protein that is kept at low levels in cells by efficient ubiquitination and degradation. The cellular fate of proto...

  20. Human genome: proto-oncogenes and proretroviruses.

    Science.gov (United States)

    Kisselev, L L; Chumakov, I M; Zabarovsky, E R; Prassolov, V S; Mett, V L; Berditchevsky, F B; Tret'yakov, L D

    1985-01-01

    A brief review of the studies undertaken at the Laboratory for Molecular Bases of Oncogenesis (Institute of Molecular Biology, Moscow) till middle of 1984 is presented. The human genome contains multiple dispersed nucleotide sequences related to the proto-oncogene mos and to proretroviral sequences in tight juxtaposition to each other. From sequencing appropriate cloned fragments of human DNA in phage and plasmid vectors it follows that one of these regions, NV-1, is a pseudogene of proto-mos with partial duplications and two Alu elements intervening its coding sequence, and the other, CL-1, seems to be also a mos-related gene with a deletion of the internal part of the structural gene. CL-1 is flanked by a proretroviral-like sequence including tRNAiMet binding site and U5 (part of the long terminal repeat). The proretroviral-like sequences are transcribed in 21-35S poly(A)+RNA abundant in normal and malignant human cells. Two hypotheses are proposed: endogenous retroviruses take part in amplification of at least some proto-oncogenes; proto-oncogenes are inactivated via insertion of movable genetic elements and conversion into pseudogenes. Potential oncogenicity of a normal human genome undergoes two controversial influences: it increases due to proto-oncogene amplification and decreases due to inactivation of some of them.

  1. HUMAN PAPILLOMA VIRUS — ONCOGENIC VIRUS

    Directory of Open Access Journals (Sweden)

    A.N. Mayansky

    2010-01-01

    Full Text Available The lecture is devoted to oncogenic viruses, particularly human papilloma virus. Papilloma viral infection is found in all parts of the globe and highly contagious. In addition to exhaustive current data on classification, specifics of papilloma viruses composition and epidemiology, the author describes in great detail the malignization mechanisms of papilloma viruses pockets. Also, issues of diagnostics and specific prevention and treatment of diseases caused by this virus are illustrated. Key words: oncogenic viruses, papilloma viruses, prevention, vaccination. (Pediatric Pharmacology. – 2010; 7(4:48-55

  2. A novel putative tyrosine kinase receptor with oncogenic potential.

    Science.gov (United States)

    Janssen, J W; Schulz, A S; Steenvoorden, A C; Schmidberger, M; Strehl, S; Ambros, P F; Bartram, C R

    1991-11-01

    We have detected transforming activity by a tumorigenicity assay using NIH3T3 cells transfected with DNA from a chronic myeloproliferative disorder patient. Here, we report the cDNA cloning of the corresponding oncogene, designated UFO, in allusion to the as yet unidentified function of its protein. Nucleotide sequence analysis of a 3116bp cDNA clone revealed a 2682-bp-long open reading frame capable of directing the synthesis of a 894 amino acid polypeptide. The predicted UFO protein exhibits characteristic features of a transmembrane receptor with associated tyrosine kinase activity. The UFO proto-oncogene maps to human chromosome 19q13.1 and is transcribed into two 5.0 kb and 3.2 kb mRNAs in human bone marrow and human tumor cell lines. The UFO locus is evolutionarily conserved between vertebrate species. A 4.0 kb mRNA of the murine UFO homolog is expressed in a variety of different mouse tissues. We thus have identified a novel element of the complex signaling network involved in the control of cell proliferation and differentiation.

  3. Oncogenic GNAQ mutations are not correlated with disease-free survival in uveal melanoma

    NARCIS (Netherlands)

    Bauer, J.; Kilic, E.; Vaarwater, J.; Bastian, B. C.; Garbe, C.; de Klein, A.

    2009-01-01

    BACKGROUND: Recently, oncogenic G protein alpha subunit q (GNAQ) mutations have been described in about 50% of uveal melanomas and in the blue nevi of the skin. METHODS: GNAQ exon 5 was amplified from 75 ciliary body and choroidal melanoma DNAs and sequenced directly. GNAQ mutation status was correl

  4. Oncogenic NRAS Primes Primary Acute Myeloid Leukemia Cells for Differentiation.

    Directory of Open Access Journals (Sweden)

    Cornelia Brendel

    Full Text Available RAS mutations are frequently found among acute myeloid leukemia patients (AML, generating a constitutively active signaling protein changing cellular proliferation, differentiation and apoptosis. We have previously shown that treatment of AML patients with high-dose cytarabine is preferentially beneficial for those harboring oncogenic RAS. On the basis of a murine AML cell culture model, we ascribed this effect to a RAS-driven, p53-dependent induction of differentiation. Hence, in this study we sought to confirm the correlation between RAS status and differentiation of primary blasts obtained from AML patients. The gene expression signature of AML blasts with oncogenic NRAS indeed corresponded to a more mature profile compared to blasts with wildtype RAS, as demonstrated by gene set enrichment analysis (GSEA and real-time PCR analysis of myeloid ecotropic viral integration site 1 homolog (MEIS1 in a unique cohort of AML patients. In addition, in vitro cell culture experiments with established cell lines and a second set of primary AML cells showed that oncogenic NRAS mutations predisposed cells to cytarabine (AraC driven differentiation. Taken together, our findings show that AML with inv(16 and NRAS mutation have a differentiation gene signature, supporting the notion that NRAS mutation may predispose leukemic cells to AraC induced differentiation. We therefore suggest that promotion of differentiation pathways by specific genetic alterations could explain the superior treatment outcome after therapy in some AML patient subgroups. Whether a differentiation gene expression status may generally predict for a superior treatment outcome in AML needs to be addressed in future studies.

  5. Single nucleotide polymorphisms in microRNA binding sites of oncogenes: implications in cancer and pharmacogenomics.

    Science.gov (United States)

    Manikandan, Mayakannan; Munirajan, Arasambattu Kannan

    2014-02-01

    Cancer, a complex genetic disease involving uncontrolled cell proliferation, is caused by inactivation of tumor suppressor genes and activation of oncogenes. A vast majority of these cancer causing genes are known targets of microRNAs (miRNAs) that bind to complementary sequences in 3' untranslated regions (UTR) of messenger RNAs and repress them from translation. Single Nucleotide Polymorphisms (SNPs) occurring naturally in such miRNA binding regions can alter the miRNA:mRNA interaction and can significantly affect gene expression. We hypothesized that 3'UTR SNPs in miRNA binding sites of proto-oncogenes could abrogate their post-transcriptional regulation, resulting in overexpression of oncogenic proteins, tumor initiation, progression, and modulation of drug response in cancer patients. Therefore, we developed a systematic computational pipeline that integrates data from well-established databases, followed stringent selection criteria and identified a panel of 30 high-confidence SNPs that may impair miRNA target sites in the 3' UTR of 54 mRNA transcripts of 24 proto-oncogenes. Further, 8 SNPs amidst them had the potential to determine therapeutic outcome in cancer patients. Functional annotation suggested that altogether these SNPs occur in proto-oncogenes enriched for kinase activities. We provide detailed in silico evidence for the functional effect of these candidate SNPs in various types of cancer.

  6. Oncogene mutational profile in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang ZC

    2014-03-01

    Full Text Available Zi-Chen Zhang,1,* Sha Fu,1,* Fang Wang,1 Hai-Yun Wang,1 Yi-Xin Zeng,2 Jian-Yong Shao11Department of Molecular Diagnostics, 2Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People's Republic of China *These authors contributed equally to this work Abstract: Nasopharyngeal carcinoma (NPC is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher's exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1% NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%, five NRAS mutations (4.1%, four KIT mutations (3.3%, two PDGFRA mutations (1.6%, two ABL mutations (1.6%, and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%. Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019. No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis. Keywords: NPC, oncogene, mutation

  7. Bioinformatics of non small cell lung cancer and the ras proto-oncogene

    CERN Document Server

    Kashyap, Amita; Babu M, Naresh

    2015-01-01

    Cancer is initiated by activation of oncogenes or inactivation of tumor suppressor genes. Mutations in the K-ras proto-oncogene are responsible for 10–30% of adenocarcinomas. Clinical Findings point to a wide variety of other cancers contributing to lung cancer incidence. Such a scenario makes identification of lung cancer difficult and thus identifying its mechanisms can contribute to the society. Identifying unique conserved patterns common to contributing proto-oncogenes may further be a boon to Pharmacogenomics and pharmacoinformatics. This calls for ab initio/de novo drug discovery that in turn will require a comprehensive in silico approach of Sequence, Domain, Phylogenetic and Structural analysis of the receptors, ligand screening and optimization and detailed Docking studies. This brief involves extensive role of the RAS subfamily that includes a set of proteins, which cause an over expression of cancer-causing genes like M-ras and initiate tumour formation in lungs. SNP Studies and Structure based ...

  8. Polymorphic changes of cell phenotype caused by elevated expression of an exogenous NEU proto-oncogene.

    Science.gov (United States)

    Tarakhovsky, A M; Resnikov, M; Zaichuk, T; Tugusheva, M V; Butenko, Z A; Prassolov, V S

    1990-03-01

    The NEU proto-oncogene encodes a 185,000 dalton transmembrane glycoprotein with extensive homology to epidermal growth factor receptor. In the current study the effect of exogenous NEU expression on phenotype and growth properties of cells established lines was examined. The replication defective retroviruses were used to express constitutively NEU cDNA in the Rat-1, NIH3T3 and Balb/c3T3 cells. In spite of the practically similar NEU mRNA and protein content in infected cells only in Balb/c3T3 cells, high NEU expression ultimately led to oncogenic transformation. The Rat-1 cells were practically insensitive to oncogenic action of NEU. Subpopulation divergency with respect to NEU-dependent transformation was also revealed in infected NIH3T3 cells. These results suggest the existence of unknown host-specific factor(s) determining the response of cells to NEU overexpression.

  9. Multiple oncogenic mutations related to targeted therapy in nasopharyngeal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jian-Wei Zhang; Hong-Yuan Zhao; Yu-Xiang Ma; Zhi-Huang Hu; Pei-Yu Huang; Li Zhang; Tao Qin; Shao-Dong Hong; Jing Zhang; Wen-Feng Fang; Yuan-Yuan Zhao; Yun-Peng Yang; Cong Xue; Yan Huang

    2015-01-01

    Introduction:An increasing number of targeted drugs have been tested for the treatment of nasopharyngeal carcinoma (NPC). However, targeted therapy-related oncogenic mutations have not been fully evaluated. This study aimed to detect targeted therapy-related oncogenic mutations in NPC and to determine which targeted therapy might be potentially effective in treating NPC. Methods:By using the SNaPshot assay, a rapid detection method, 19 mutation hotspots in 6 targeted therapy-related oncogenes were examined in 70 NPC patients. The associations between oncogenic mutations and clinicopathologic factors were analyzed. Results:Among 70 patients, 12 (17.1%) had mutations in 5 oncogenes:7 (10.0%) had v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) mutation, 2 (2.8%) had epidermal growth factor receptor (EGFR) mutation, 1 (1.4%) had phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) mutation, 1 (1.4%) had Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation, and 1 (1.4%) had simultaneous EGFR and v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) mutations. No significant differences were observed between oncogenic mutations and clinicopathologic characteristics. Additionally, these oncogenic mutations were not associated with tumor recurrence and metastasis. Conclusions:Oncogenic mutations are present in NPC patients. The efficacy of targeted drugs on patients with the related oncogenic mutations requires further validation.

  10. Oncogenic c-kit transcript is a target for binase.

    Science.gov (United States)

    Mitkevich, Vladimir A; Petrushanko, Irina Y; Kretova, Olga V; Zelenikhin, Pavel V; Prassolov, Vladimir S; Tchurikov, Nickolai A; Ilinskaya, Olga N; Makarov, Alexander A

    2010-07-01

    Mutational activation of c-Kit receptor tyrosine kinase is common in acute myelogenous leukemia (AML). One such activating point mutation is the N822K replacement in the c-Kit protein. Here we investigate the selective cytotoxic effect of binase--RNase from Bacillus intermedius--on FDC-P1-N822K cells. These cells were derived from myeloid progenitor FDC-P1 cells, in which ectopic expression of N822K c-kit gene induces interleukin-3 independent growth. In order to determine whether the sensitivity of these cells to binase is caused by the expression of c-kit oncogene, the cytotoxicity of the RNase was studied in the presence of selective inhibitor of mutated c-Kit imatinib (Gleevec). Inhibition of mutated c-Kit protein leads to the loss of cell sensitivity to the apoptotic effect of binase, while the latter still decreases the amount of cellular RNA. Using green fluorescent protein as an expression marker for the c-Kit oncoprotein, we demonstrate that the elimination of c-Kit is the key factor in selective cytotoxicity of binase. Quantitative RT-PCR with RNA samples isolated from the binase-treated FDC-P1-N822K cells shows that binase treatment results in 41% reduction in the amount of с-kit mRNA. This indicates that the transcript of the activated mutant c-kit is the target for toxic action of binase. Thus, the combination of inhibition of oncogenic protein with the destruction of its mRNA is a promising approach to eliminating malignant cells.

  11. Oncogenic Splicing Factor SRSF1 Is a Critical Transcriptional Target of MYC

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    Shipra Das

    2012-02-01

    Full Text Available The SR protein splicing factor SRSF1 is a potent proto-oncogene that is frequently upregulated in cancer. Here, we show that SRSF1 is a direct target of the transcription factor oncoprotein MYC. These two oncogenes are significantly coexpressed in lung carcinomas, and MYC knockdown downregulates SRSF1 expression in lung-cancer cell lines. MYC directly activates transcription of SRSF1 through two noncanonical E-boxes in its promoter. The resulting increase in SRSF1 protein is sufficient to modulate alternative splicing of a subset of transcripts. In particular, MYC induction leads to SRSF1-mediated alternative splicing of the signaling kinase MKNK2 and the transcription factor TEAD1. SRSF1 knockdown reduces MYC's oncogenic activity, decreasing proliferation and anchorage-independent growth. These results suggest a mechanism for SRSF1 upregulation in tumors with elevated MYC and identify SRSF1 as a critical MYC target that contributes to its oncogenic potential by enabling MYC to regulate the expression of specific protein isoforms through alternative splicing.

  12. Expression of bcl-2 oncogene in gastric precancerous lesions and its correlation with syndromes in traditional Chinese medicine

    Institute of Scientific and Technical Information of China (English)

    Ling Hu; Shao-Xian Lao; Chun-Zhi Tang

    2005-01-01

    AIM: To observe the protein and mRNA expression of bcl-2 oncogene in gastric precancerous lesions (GPL) and to analyze its correlation with syndromes in traditional Chinese medicine (TCM).METHODS: Sixty-seven patients with GPL confirmed by gastroscopy and pathology were studied, including 39 cases of moderate gastric mucosal dysplasia, 19 casesof severe gastric mucosa dysplasia, g cases of incompletecolon metaplasia. In syndrome differentiation of TCM, 17 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by qi stagnation, 21 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by stomach heat, 29 cases belonged to the syndrome of qi and yin deficiency of the spleen and stomach complicated by blood stasis. Protein and mRNA expression of bcl-2 oncogene weredetected by labeled streptavidin biotin (LSAB) immunohistochemistry and in situ hybridization respectively. RESULTS: Abnormal expression of protein and mRNA on bcl-2 oncogene was found in GPL, which increased gradually with the course of lesions. In moderate and severe gastric mucosal dysplasia and incomplete colon metaplasia, there was no difference in the expression of bcl-2 oncogene (P>0.05). In different accompanying syndromes, the expression of protein and mRNA on bcl-2 oncogene increased gradually in the following order: deficiency of both qi and yin of the spleen and stomach accompanying qi stagnation → stomach heat → blood stasis. In GPL, compared with accompanying blood stasis, there was an obvious difference in the expression of bd-2 oncogene between the syndrome of qi and yin deficiency of the spleen and stomach and accompanying stomach heat, so did accompanying qi stagnation (the level of protein: χ2 = 8.45, P<0.05; the level of mRNA: χ2 = 7.35,P<0.05).CONCLUSION: Apoptosis-associated bcl-2 oncogene is abnormally expressed in GPL, which correlates with different accompanying syndromes in TCM.

  13. Control of autophagy by oncogenes and tumor suppressor genes.

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    Maiuri, M C; Tasdemir, E; Criollo, A; Morselli, E; Vicencio, J M; Carnuccio, R; Kroemer, G

    2009-01-01

    Multiple oncogenes (in particular phosphatidylinositol 3-kinase, PI3K; activated Akt1; antiapoptotic proteins from the Bcl-2 family) inhibit autophagy. Similarly, several tumor suppressor proteins (such as BH3-only proteins; death-associated protein kinase-1, DAPK1; the phosphatase that antagonizes PI3K, PTEN; tuberous sclerosic complex 1 and 2, TSC1 and TSC2; as well as LKB1/STK11) induce autophagy, meaning that their loss reduces autophagy. Beclin-1, which is required for autophagy induction acts as a haploinsufficient tumor suppressor protein, and other essential autophagy mediators (such as Atg4c, UVRAG and Bif-1) are bona fide oncosuppressors. One of the central tumor suppressor proteins, p53 exerts an ambiguous function in the regulation of autophagy. Within the nucleus, p53 can act as an autophagy-inducing transcription factor. Within the cytoplasm, p53 exerts a tonic autophagy-inhibitory function, and its degradation is actually required for the induction of autophagy. The role of autophagy in oncogenesis and anticancer therapy is contradictory. Chronic suppression of autophagy may stimulate oncogenesis. However, once a tumor is formed, autophagy inhibition may be a therapeutic goal for radiosensitization and chemosensitization. Altogether, the current state-of-the art suggests a complex relationship between cancer and deregulated autophagy that must be disentangled by further in-depth investigation.

  14. Oncogenic human papillomaviruses activate the tumor-associated lens epithelial-derived growth factor (LEDGF gene.

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    Jenny Leitz

    2014-03-01

    Full Text Available The expression of the human papillomavirus (HPV E6/E7 oncogenes is crucial for HPV-induced malignant cell transformation. The identification of cellular targets attacked by the HPV oncogenes is critical for our understanding of the molecular mechanisms of HPV-associated carcinogenesis and may open novel therapeutic opportunities. Here, we identify the Lens Epithelial-Derived Growth Factor (LEDGF gene as a novel cellular target gene for the HPV oncogenes. Elevated LEDGF expression has been recently linked to human carcinogenesis and can protect tumor cells towards different forms of cellular stress. We show that intracellular LEDGF mRNA and protein levels in HPV-positive cancer cells are critically dependent on the maintenance of viral oncogene expression. Ectopic E6/E7 expression stimulates LEDGF transcription in primary keratinocytes, at least in part via activation of the LEDGF promoter. Repression of endogenous LEDGF expression by RNA interference results in an increased sensitivity of HPV-positive cancer cells towards genotoxic agents. Immunohistochemical analyses of cervical tissue specimens reveal a highly significant increase of LEDGF protein levels in HPV-positive lesions compared to histologically normal cervical epithelium. Taken together, these results indicate that the E6/E7-dependent maintenance of intracellular LEDGF expression is critical for protecting HPV-positive cancer cells against various forms of cellular stress, including DNA damage. This could support tumor cell survival and contribute to the therapeutic resistance of cervical cancers towards genotoxic treatment strategies in the clinic.

  15. Oncogenic Human Papillomaviruses Activate the Tumor-Associated Lens Epithelial-Derived Growth Factor (LEDGF) Gene

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    Leitz, Jenny; Reuschenbach, Miriam; Lohrey, Claudia; Honegger, Anja; Accardi, Rosita; Tommasino, Massimo; Llano, Manuel; von Knebel Doeberitz, Magnus; Hoppe-Seyler, Karin; Hoppe-Seyler, Felix

    2014-01-01

    The expression of the human papillomavirus (HPV) E6/E7 oncogenes is crucial for HPV-induced malignant cell transformation. The identification of cellular targets attacked by the HPV oncogenes is critical for our understanding of the molecular mechanisms of HPV-associated carcinogenesis and may open novel therapeutic opportunities. Here, we identify the Lens Epithelial-Derived Growth Factor (LEDGF) gene as a novel cellular target gene for the HPV oncogenes. Elevated LEDGF expression has been recently linked to human carcinogenesis and can protect tumor cells towards different forms of cellular stress. We show that intracellular LEDGF mRNA and protein levels in HPV-positive cancer cells are critically dependent on the maintenance of viral oncogene expression. Ectopic E6/E7 expression stimulates LEDGF transcription in primary keratinocytes, at least in part via activation of the LEDGF promoter. Repression of endogenous LEDGF expression by RNA interference results in an increased sensitivity of HPV-positive cancer cells towards genotoxic agents. Immunohistochemical analyses of cervical tissue specimens reveal a highly significant increase of LEDGF protein levels in HPV-positive lesions compared to histologically normal cervical epithelium. Taken together, these results indicate that the E6/E7-dependent maintenance of intracellular LEDGF expression is critical for protecting HPV-positive cancer cells against various forms of cellular stress, including DNA damage. This could support tumor cell survival and contribute to the therapeutic resistance of cervical cancers towards genotoxic treatment strategies in the clinic. PMID:24604027

  16. Oncogenic human papillomaviruses activate the tumor-associated lens epithelial-derived growth factor (LEDGF) gene.

    Science.gov (United States)

    Leitz, Jenny; Reuschenbach, Miriam; Lohrey, Claudia; Honegger, Anja; Accardi, Rosita; Tommasino, Massimo; Llano, Manuel; von Knebel Doeberitz, Magnus; Hoppe-Seyler, Karin; Hoppe-Seyler, Felix

    2014-03-01

    The expression of the human papillomavirus (HPV) E6/E7 oncogenes is crucial for HPV-induced malignant cell transformation. The identification of cellular targets attacked by the HPV oncogenes is critical for our understanding of the molecular mechanisms of HPV-associated carcinogenesis and may open novel therapeutic opportunities. Here, we identify the Lens Epithelial-Derived Growth Factor (LEDGF) gene as a novel cellular target gene for the HPV oncogenes. Elevated LEDGF expression has been recently linked to human carcinogenesis and can protect tumor cells towards different forms of cellular stress. We show that intracellular LEDGF mRNA and protein levels in HPV-positive cancer cells are critically dependent on the maintenance of viral oncogene expression. Ectopic E6/E7 expression stimulates LEDGF transcription in primary keratinocytes, at least in part via activation of the LEDGF promoter. Repression of endogenous LEDGF expression by RNA interference results in an increased sensitivity of HPV-positive cancer cells towards genotoxic agents. Immunohistochemical analyses of cervical tissue specimens reveal a highly significant increase of LEDGF protein levels in HPV-positive lesions compared to histologically normal cervical epithelium. Taken together, these results indicate that the E6/E7-dependent maintenance of intracellular LEDGF expression is critical for protecting HPV-positive cancer cells against various forms of cellular stress, including DNA damage. This could support tumor cell survival and contribute to the therapeutic resistance of cervical cancers towards genotoxic treatment strategies in the clinic.

  17. Correlation between oncogenic mutations and parameter sensitivity of the apoptosis pathway model.

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    Jia Chen

    2014-01-01

    Full Text Available One of the major breakthroughs in oncogenesis research in recent years is the discovery that, in most patients, oncogenic mutations are concentrated in a few core biological functional pathways. This discovery indicates that oncogenic mechanisms are highly related to the dynamics of biologic regulatory networks, which govern the behaviour of functional pathways. Here, we propose that oncogenic mutations found in different biological functional pathways are closely related to parameter sensitivity of the corresponding networks. To test this hypothesis, we focus on the DNA damage-induced apoptotic pathway--the most important safeguard against oncogenesis. We first built the regulatory network that governs the apoptosis pathway, and then translated the network into dynamics equations. Using sensitivity analysis of the network parameters and comparing the results with cancer gene mutation spectra, we found that parameters that significantly affect the bifurcation point correspond to high-frequency oncogenic mutations. This result shows that the position of the bifurcation point is a better measure of the functionality of a biological network than gene expression levels of certain key proteins. It further demonstrates the suitability of applying systems-level analysis to biological networks as opposed to studying genes or proteins in isolation.

  18. Role of STAT3 in in vitro transformation triggered by TRK oncogenes.

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    Claudia Miranda

    Full Text Available TRK oncoproteins are chimeric versions of the NTRK1/NGF receptor and display constitutive tyrosine kinase activity leading to transformation of NIH3T3 cells and neuronal differentiation of PC12 cells. Signal Transducer and Activator of Transcription (STAT 3 is activated in response to cytokines and growth factors and it has been recently identified as a novel signal transducer for TrkA, mediating the functions of NGF in nervous system. In this paper we have investigated STAT3 involvement in signalling induced by TRK oncogenes. We showed that TRK oncogenes trigger STAT3 phosphorylation both on Y705 and S727 residues and STAT3 transcriptional activity. MAPK pathway was involved in the induction of STAT3 phosphorylation. Interestingly, we have shown reduced STAT3 protein level in NIH3T3 transformed foci expressing TRK oncogenes. Overall, we have unveiled a dual role for STAT3 in TRK oncogenes-induced NIH3T3 transformation: i decreased STAT3 protein levels, driven by TRK oncoproteins activity, are associated to morphological transformation; ii residual STAT3 transcriptional activity is required for cell growth.

  19. Characterization of TRPS1 and ERAS as oncogenes implicated in breast cancer

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    Lopez Gonzalez, L.

    2015-07-01

    New high throughput technologies have made possible to identify putative oncogenes in breast cancer. In this project we aim to relate and characterise two novel putative oncogenes, ERAS and TRPS1, in their role in human breast cancer. TRPS1, an atypical GATA factor, modulates cell proliferation and controls cell cycle progression through repression of GATA-regulated genes, therefore acting as a tumour suppressor gene. Conversely, TRPS1 expression has been shown to be significantly elevated in luminal and in a lesser extent in basal breast cancer cells, presenting roles both as an oncogene and as a tumour suppressor gene in breast cancer development. The aim of this project is therefore to determine the characteristics of TRPS1 either as a putative novel human oncogene or as a tumour suppressor gene in breast cancer cells. To this aim, we have cloned a novel isoform of TRPS1 and introduced it into several breast cancer cell lines. Our results show that overexpression of this isoform of TRPS1 results in variations in motility in non-carcinogenic cell lines, as well as in a series of EMT-like changes such as the down-regulation of the EMT marker E-cadherin, both of which can be associated to an increase in malignancy, suggesting an oncogenic behaviour for TRPS1. Furthermore, our results suggest that constitutively active members of the RAS protein family induce the expression of TRPS1, establishing a relationship between both genes. We can conclude that the effects of TRPS1 overexpression are moderate, inducing some changes but not fully transforming the cells. Therefore we cannot confirm that TRPS1 is a putative oncogene in breast cancer. (Author)

  20. Activation of proto-oncogenes by disruption of chromosome neighborhoods.

    Science.gov (United States)

    Hnisz, Denes; Weintraub, Abraham S; Day, Daniel S; Valton, Anne-Laure; Bak, Rasmus O; Li, Charles H; Goldmann, Johanna; Lajoie, Bryan R; Fan, Zi Peng; Sigova, Alla A; Reddy, Jessica; Borges-Rivera, Diego; Lee, Tong Ihn; Jaenisch, Rudolf; Porteus, Matthew H; Dekker, Job; Young, Richard A

    2016-03-25

    Oncogenes are activated through well-known chromosomal alterations such as gene fusion, translocation, and focal amplification. In light of recent evidence that the control of key genes depends on chromosome structures called insulated neighborhoods, we investigated whether proto-oncogenes occur within these structures and whether oncogene activation can occur via disruption of insulated neighborhood boundaries in cancer cells. We mapped insulated neighborhoods in T cell acute lymphoblastic leukemia (T-ALL) and found that tumor cell genomes contain recurrent microdeletions that eliminate the boundary sites of insulated neighborhoods containing prominent T-ALL proto-oncogenes. Perturbation of such boundaries in nonmalignant cells was sufficient to activate proto-oncogenes. Mutations affecting chromosome neighborhood boundaries were found in many types of cancer. Thus, oncogene activation can occur via genetic alterations that disrupt insulated neighborhoods in malignant cells.

  1. Melanoma: oncogenic drivers and the immune system

    Science.gov (United States)

    Karachaliou, Niki; Pilotto, Sara; Teixidó, Cristina; Viteri, Santiago; González-Cao, María; Riso, Aldo; Morales-Espinosa, Daniela; Molina, Miguel Angel; Chaib, Imane; Santarpia, Mariacarmela; Richardet, Eduardo; Bria, Emilio

    2015-01-01

    Advances and in-depth understanding of the biology of melanoma over the past 30 years have contributed to a change in the consideration of melanoma as one of the most therapy-resistant malignancies. The finding that oncogenic BRAF mutations drive tumor growth in up to 50% of melanomas led to a molecular therapy revolution for unresectable and metastatic disease. Moving beyond BRAF, inactivation of immune regulatory checkpoints that limit T cell responses to melanoma has provided targets for cancer immunotherapy. In this review, we discuss the molecular biology of melanoma and we focus on the recent advances of molecularly targeted and immunotherapeutic approaches. PMID:26605311

  2. The in Silico Approach to Identify a Unique Plant-Derived Inhibitor Against E6 and E7 Oncogenic Proteins of High-Risk Human Papillomavirus 16 and 18

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    Kumar

    2016-05-01

    Full Text Available Background Globally, the human papillomavirus (HPV remains the foremost cause of cancer mortality among women. There is a need to identify natural anti-cancerous compounds that can fight against life-threatening infections by HPV. Various kinds of natural plant-originated compounds have been used in the traditional system of medicine for cancer therapy. Different studies have reported the effective inhibition of HPV infection enacted by certain natural compounds. Out of all the different HPV types, HPV-16 and 18 are the ones mainly associated with causing cervical cancer; furthermore, the E6 and E7 oncoproteins of these two high-risk HPV types typically interact with tumor protein 53 (p53 and retinoblastoma tumor suppressor proteins (pRb of human host which consequent to cancer formation. Objectives The goal of this study is to identify unique plant-originated compounds to utilize in order to combat the high-risk human papillomavirus oncoproteins using docking measures. Materials and Methods Twelve natural compounds jaceosidin, withaferin A, curcumin, epigallocatechin-3-gallate (EGCG, artemisinin, gingerol, ursolic acid, ferulic acid, berberin, silymarin, resveratrol, and indol-3-carbinol were docked against E6 and E7 oncoproteins of high-risk HPV types 16 and 18 using a protein-ligand docking software called AutoDock4.2. Results Out of these 12 natural compounds, withaferin A was found to inhibit all four oncoproteins with minimum binding energy. Conclusions These in silico findings indicate that withaferin A may be used as a common drug for cervical cancer caused by high-risk HPV types, perhaps by restoring the normal functions of tumor suppressor proteins.

  3. The Homeodomain Transcription Factor Cdx1 Does Not Behave as an Oncogene in Normal Mouse Intestine

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    Mary Ann S. Crissey

    2008-01-01

    Full Text Available The Caudal-related homeobox genes Cdx1 and Cdx2 are intestine-specific transcription factors that regulate differentiation of intestinal cell types. Previously, we have shown Cdx1 to be antiproliferative and to promote cell differentiation. However, other studies have suggested that Cdx1 may be an oncogene. To test for oncogenic behavior, we used the murine villin promoter to ectopically express Cdx1 in the small intestinal villi and colonic surface epithelium. No changes in intestinal architecture, cell differentiation, or lineage selection were observed with expression of the transgene. Classic oncogenes enhance proliferation and induce tumors when ectopically expressed. However, the Cdx1 transgene neither altered intestinal proliferation nor induced spontaneous intestinal tumors. In a murine model for colitis-associated cancer, the Cdx1 transgene decreased, rather than increased, the number of adenomas that developed. In the polyps, the expression of the endogenous and the transgenic Cdx1 proteins was largely absent, whereas endogenous Villin expression was retained. This suggests that transgene silencing was specific and not due to a general Villin inactivation. In conclusion, neither the ectopic expression of Cdx1 was associated with changes in intestinal cell proliferation or differentiation nor was there increased intestinal cancer susceptibility. Our results therefore suggest that Cdx1 is not an oncogene in normal intestinal epithelium.

  4. The contribution of tumor and host tissue factor expression to oncogene-driven gliomagenesis.

    Science.gov (United States)

    Magnus, Nathalie; Meehan, Brian; Garnier, Delphine; Hashemi, Maryam; Montermini, Laura; Lee, Tae Hoon; Milsom, Chloe; Pawlinski, Rafal; Ohlfest, John; Anderson, Mark; Mackman, Nigel; Rak, Janusz

    2014-11-14

    Glioblastoma multiforme (GBM) is an aggressive form of glial brain tumors, associated with angiogenesis, thrombosis, and upregulation of tissue factor (TF), the key cellular trigger of coagulation and signaling. Since TF is upregulated by oncogenic mutations occurring in different subsets of human brain tumors we investigated whether TF contributes to tumourigenesis driven by oncogenic activation of EGFR (EGFRvIII) and RAS pathways in the brain. Here we show that TF expression correlates with poor prognosis in glioma, but not in GBM. In situ, the TF protein expression is heterogeneously expressed in adult and pediatric gliomas. GBM cells harboring EGFRvIII (U373vIII) grow aggressively as xenografts in SCID mice and their progression is delayed by administration of monoclonal antibodies blocking coagulant (CNTO 859) and signaling (10H10) effects of TF in vivo. Mice in which TF gene is disrupted in the neuroectodermal lineage exhibit delayed progression of spontaneous brain tumors driven by oncogenic N-ras and SV40 large T antigen (SV40LT) expressed under the control of sleeping beauty transposase. Reduced host TF levels in low-TF/SCID hypomorphic mice mitigated growth of glioma subcutaneously but not in the brain. Thus, we suggest that tumor-associated TF may serve as therapeutic target in the context of oncogene-driven disease progression in a subset of glioma.

  5. Calpain Activity Is Generally Elevated during Transformation but Has Oncogene-Specific Biological Functions

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    N.O. Carragher

    2004-01-01

    Full Text Available Several oncogene and tumor-suppressor gene products are known substrates for the calpain family of cysteine proteases, and calpain is required for transformation by v-src and tumor invasion. Thus, we have now addressed whether calpain is generally associated with transformation and how calpain contributes to oncogene function. Our results demonstrate that calpain activity is enhanced upon transformation induced by the v-Src, v-Jun, v-Myc, k-Ras, and v-Fos oncoproteins. Furthermore, elevated calpain activity commonly promotes focal adhesion remodelling, disruption of actin cytoskeleton, morphological transformation, and cell migration, although proteolysis of target substrates (such as focal adhesion kinase, talin, and spectrin is differently specified by individual oncoproteins. Interestingly, v-Fos differs from other common oncoproteins in not requiring calpain activity for actin/adhesion remodelling or migration of v-Fos transformed cells. However, anchorage-independent growth of all transformed cells is sensitive to calpain inhibition. In addition, elevated calpain activity contributes to oncogene-induced apoptosis associated with transformation by v-Myc. Taken together, these studies demonstrate that calpain activity is necessary for full cellular transformation induced by common oncoproteins, but has distinct roles in oncogenic events induced by individual transforming proteins. Thus, targeting calpain activity may represent a useful general strategy for interfering with activated protooncogenes in cancer cells.

  6. DNA topoisomerases participate in fragility of the oncogene RET.

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    Laura W Dillon

    Full Text Available Fragile site breakage was previously shown to result in rearrangement of the RET oncogene, resembling the rearrangements found in thyroid cancer. Common fragile sites are specific regions of the genome with a high susceptibility to DNA breakage under conditions that partially inhibit DNA replication, and often coincide with genes deleted, amplified, or rearranged in cancer. While a substantial amount of work has been performed investigating DNA repair and cell cycle checkpoint proteins vital for maintaining stability at fragile sites, little is known about the initial events leading to DNA breakage at these sites. The purpose of this study was to investigate these initial events through the detection of aphidicolin (APH-induced DNA breakage within the RET oncogene, in which 144 APH-induced DNA breakpoints were mapped on the nucleotide level in human thyroid cells within intron 11 of RET, the breakpoint cluster region found in patients. These breakpoints were located at or near DNA topoisomerase I and/or II predicted cleavage sites, as well as at DNA secondary structural features recognized and preferentially cleaved by DNA topoisomerases I and II. Co-treatment of thyroid cells with APH and the topoisomerase catalytic inhibitors, betulinic acid and merbarone, significantly decreased APH-induced fragile site breakage within RET intron 11 and within the common fragile site FRA3B. These data demonstrate that DNA topoisomerases I and II are involved in initiating APH-induced common fragile site breakage at RET, and may engage the recognition of DNA secondary structures formed during perturbed DNA replication.

  7. Identification of lung cancer oncogenes based on the mRNA expression and single nucleotide polymorphism profile data.

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    Wang, Y; Mei, Q; Ai, Y Q; Li, R Q; Chang, L; Li, Y F; Xia, Y X; Li, W H; Chen, Y

    2015-01-01

    This study aimed to identify the oncogenes associated with lung cancer based on the mRNA and single nucleotide polymorphism (SNP) profile data. The mRNA expression profile data of GSE43458 (80 cancer and 30 normal samples) and SNP profile data of GSE33355 (61 pairs of lung cancer samples and control samples) were downloaded from Gene Expression Omnibus database. Common genes between the mRNA profile and SNP profile were identified as the lung cancer oncogenes. Risk subpathways of the selected oncogenes with the SNP locus were analyzed using the iSubpathwayMiner package in R. Moreover, protein-protein interaction (PPI) network of the oncogenes was constructed using the HPRD database and then visualized using the Cytoscape. Totally, 3004 DEGs (1105 up-regulated and 1899 down-regulated) and 125 significant SNPs closely related to 174 genes in the lung cancer samples were identified. Also, 39 common genes, like PFKP (phosphofructokinase, platelet) and DGKH-rs11616202 (diacylglycerol kinase, eta) that enriched in sub-pathways such as galactose metabolism, fructose and mannose metabolism, and pentose phosphate pathway, were identified as the lung cancer oncogenes. Besides, PIK3R1 (phosphoinositide-3-kinase, regulatory subunit 1), RORA (RAR-related orphan receptor A), MAGI3 (membrane associated guanylate kinase, WW and PDZ domain containing 3), PTPRM (protein tyrosine phosphatase, receptor type, M), and BMP6 (bone morphogenetic protein 6) were the hub genes in PPI network. Our study suggested that PFKP and DGKH that enriched in galactose metabolism, fructose and mannose metabolism pathway, as well as PIK3R1, RORA, and MAGI3, may be the lung cancer oncogenes.

  8. Intracortical osteoblastic osteosarcoma with oncogenic rickets

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    Hasegawa, T.; Hirohashi, Setsuo [Pathology Division, National Cancer Center Research Institute, Tokyo (Japan); Shimoda, Tadakazu [Clinical Laboratory Division, National Cancer Center Hospital, Tokyo (Japan); Yokoyama, Ryohei; Beppu, Yasuo [Orthopedic Division, National Cancer Center Hospital, Tokyo (Japan); Maeda, Shotaro [Department of Pathology, Nippon Medical School Hospital, Tokyo (Japan)

    1999-01-01

    Intracortical osteosarcoma is the rarest variant of osteosarcoma, occurring within, and usually confined to, the cortical bone. Oncogenic osteomalacia, or rickets, is an unusual clinicopathologic entity in which vitamin D-resistant osteomalacia, or rickets, occurs in association with some tumors of soft tissue or bone. We present a case of oncogenic rickets associated with intracortical osteosarcoma of the tibia in a 9-year-old boy, whose roentgenographic abnormalities of rickets disappeared and pertinent laboratory data except for serum alkaline phosphatase became normal after surgical resection of the tumor. Histologically, the tumor was an osteosarcoma with a prominent osteoblastic pattern. An unusual microscopic feature was the presence of matrix mineralization showing rounded calcified structures (calcified spherules). Benign osteoblastic tumors, such as osteoid osteoma and osteoblastoma, must be considered in the differential diagnosis because of the relatively low cellular atypia and mitotic activity of this tumor. The infiltrating pattern with destruction or engulfment of normal bone is a major clue to the correct diagnosis of intracortical osteosarcoma. The co-existing radiographic changes of rickets were due to the intracortical osteosarcoma. (orig.) With 8 figs., 25 refs.

  9. Oncogenic activation of NF-kappaB.

    Science.gov (United States)

    Staudt, Louis M

    2010-06-01

    Recent genetic evidence has established a pathogenetic role for NF-kappaB signaling in cancer. NF-kappaB signaling is engaged transiently when normal B lymphocytes respond to antigens, but lymphomas derived from these cells accumulate genetic lesions that constitutively activate NF-kappaB signaling. Many genetic aberrations in lymphomas alter CARD11, MALT1, or BCL10, which constitute a signaling complex that is intermediate between the B-cell receptor and IkappaB kinase. The activated B-cell-like subtype of diffuse large B-cell lymphoma activates NF-kappaB by a variety of mechanisms including oncogenic mutations in CARD11 and a chronic active form of B-cell receptor signaling. Normal plasma cells activate NF-kappaB in response to ligands in the bone marrow microenvironment, but their malignant counterpart, multiple myeloma, sustains a variety of genetic hits that stabilize the kinase NIK, leading to constitutive activation of the classical and alternative NF-kappaB pathways. Various oncogenic abnormalities in epithelial cancers, including mutant K-ras, engage unconventional IkappaB kinases to activate NF-kappaB. Inhibition of constitutive NF-kappaB signaling in each of these cancer types induces apoptosis, providing a rationale for the development of NF-kappaB pathway inhibitors for the treatment of cancer.

  10. MSH3-deficiency initiates EMAST without oncogenic transformation of human colon epithelial cells.

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    Christoph Campregher

    Full Text Available BACKGROUND/AIM: Elevated microsatellite instability at selected tetranucleotide repeats (EMAST is a genetic signature in certain cases of sporadic colorectal cancer and has been linked to MSH3-deficiency. It is currently controversial whether EMAST is associated with oncogenic properties in humans, specifically as cancer development in Msh3-deficient mice is not enhanced. However, a mutator phenotype is different between species as the genetic positions of repetitive sequences are not conserved. Here we studied the molecular effects of human MSH3-deficiency. METHODS: HCT116 and HCT116+chr3 (both MSH3-deficient and primary human colon epithelial cells (HCEC, MSH3-wildtype were stably transfected with an EGFP-based reporter plasmid for the detection of frameshift mutations within an [AAAG]17 repeat. MSH3 was silenced by shRNA and changes in protein expression were analyzed by shotgun proteomics. Colony forming assay was used to determine oncogenic transformation and double strand breaks (DSBs were assessed by Comet assay. RESULTS: Despite differential MLH1 expression, both HCT116 and HCT116+chr3 cells displayed comparable high mutation rates (about 4×10(-4 at [AAAG]17 repeats. Silencing of MSH3 in HCECs leads to a remarkable increased frameshift mutations in [AAAG]17 repeats whereas [CA]13 repeats were less affected. Upon MSH3-silencing, significant changes in the expression of 202 proteins were detected. Pathway analysis revealed overexpression of proteins involved in double strand break repair (MRE11 and RAD50, apoptosis, L1 recycling, and repression of proteins involved in metabolism, tRNA aminoacylation, and gene expression. MSH3-silencing did not induce oncogenic transformation and DSBs increased 2-fold. CONCLUSIONS: MSH3-deficiency in human colon epithelial cells results in EMAST, formation of DSBs and significant changes of the proteome but lacks oncogenic transformation. Thus, MSH3-deficiency alone is unlikely to drive human colon

  11. JAC, a direct target of oncogenic transcription factor Jun, is involved in cell transformation and tumorigenesis.

    Science.gov (United States)

    Hartl, M; Reiter, F; Bader, A G; Castellazzi, M; Bister, K

    2001-11-20

    Using subtractive hybridization techniques, we have isolated a gene termed JAC that is strongly and specifically activated in avian fibroblasts transformed by the v-jun oncogene of avian sarcoma virus 17 (ASV17), but not in cells transformed by other oncogenic agents. Furthermore, JAC is highly expressed in cell lines derived from jun-induced avian fibrosarcomas. Kinetic analysis using a doxycycline-controlled conditional cell transformation system showed that expression of the 0.8-kb JAC mRNA is induced rapidly upon activation of the oncogenic v-jun allele. Nucleotide sequence analysis and transcriptional mapping revealed that the JAC gene contains two exons, with the longest ORF confined to exon 2. The deduced 68-amino acid chicken JAC protein is rich in cysteine residues and displays 37% sequence identity to mammalian high-sulfur keratin-associated proteins. The promoter region of JAC contains a consensus (5'-TGACTCA-3') and a nonconsensus (5'-TGAGTAA-3') AP-1 binding site in tandem, which are both specifically bound by the Gag-Jun hybrid protein encoded by ASV17. Mutational analysis revealed that the two AP-1 sites confer strong transcriptional activation by Gag-Jun in a synergistic manner. Ectopic expression of JAC in avian fibroblasts leads to anchorage-independent growth, strongly suggesting that deregulation of JAC is an essential event in jun-induced cell transformation and tumorigenesis.

  12. Oncogenic signaling by Kit tyrosine kinase occurs selectively on the Golgi apparatus in gastrointestinal stromal tumors.

    Science.gov (United States)

    Obata, Y; Horikawa, K; Takahashi, T; Akieda, Y; Tsujimoto, M; Fletcher, J A; Esumi, H; Nishida, T; Abe, R

    2017-02-13

    Gastrointestinal stromal tumors (GISTs) are caused by gain-of-function mutations in the Kit receptor tyrosine kinase. Most primary GIST patients respond to the Kit inhibitor imatinib, but this drug often becomes ineffective because of secondary mutations in the Kit kinase domain. The characteristic intracellular accumulation of imatinib-sensitive and -resistant Kit protein is well documented, but its relationship to oncogenic signaling remains unknown. Here, we show that in cancer tissue from primary GIST patients as well as in cell lines, mutant Kit accumulates on the Golgi apparatus, whereas normal Kit localizes to the plasma membrane (PM). In imatinib-resistant GIST with a secondary Kit mutation, Kit localizes predominantly on the Golgi apparatus. Both imatinib-sensitive and imatinib-resistant Kit (Kit(mut)) become fully auto-phosphorylated only on the Golgi and only if in a complex-glycosylated form. Kit(mut) accumulates on the Golgi during the early secretory pathway, but not after endocytosis. The aberrant kinase activity of Kit(mut) prevents its export from the Golgi to the PM. Furthermore, Kit(mut) on the Golgi signals and activates the phosphatidylinositol 3-kinase-Akt (PI3K-Akt) pathway, signal transducer and activator of transcription 5 (STAT5), and the Mek-Erk pathway. Blocking the biosynthetic transport of Kit(mut) to the Golgi from the endoplasmic reticulum inhibits oncogenic signaling. PM localization of Kit(mut) is not required for its signaling. Activation of Src-family tyrosine kinases on the Golgi is essential for oncogenic Kit signaling. These results suggest that the Golgi apparatus serves as a platform for oncogenic Kit signaling. Our study demonstrates that Kit(mut)'s pathogenicity is related to its mis-localization, and may offer a new strategy for treating imatinib-resistant GISTs.Oncogene advance online publication, 13 February 2017; doi:10.1038/onc.2016.519.

  13. Targeting CK2-driven non-oncogene addiction in B-cell tumors.

    Science.gov (United States)

    Mandato, E; Manni, S; Zaffino, F; Semenzato, G; Piazza, F

    2016-11-24

    Genetic mutations of oncogenes often underlie deranged cell growth and altered differentiation pathways leading to malignant transformation of B-lymphocytes. However, addiction to oncogenes is not the only drive to lymphoid tumor pathogenesis. Dependence on non-oncogenes, which act by propelling basic mechanisms of cell proliferation and survival, has also been recognized in the pathobiology of lymphoid leukemias, lymphomas and multiple myeloma. Among the growing number of molecules that may uphold non-oncogene addiction, a key place is increasingly being recognized to the serine-threonine kinase CK2. This enzyme is overexpressed and overactive in B-acute lymphoblastic leukemia, multiple myeloma, chronic lymphocytic leukemia and non-Hodgkin lymphomas, such as mantle cell, follicular, Burkitt's and diffuse large B-cell lymphomas. In these tumors, CK2 may serve the activity of oncogenes, similar to BCR-ABL and c-MYC, control the activation of critical signaling cascades, such as NF-κB (nuclear factor-κB), STAT3 (signal transducer and activator of transcription 3) and PTEN/PI3K/AKT (phosphatase and tensin homolog protein/phosphoinositide 3-kinase/AKR thymoma), and sustain multiple cellular stress-elicited pathways, such as the proteotoxic stress, unfolded protein and DNA-damage responses. CK2 has also been shown to have an essential role in tuning signals derived from the stromal tumor microenvironment. Not surprisingly, targeting CK2 in lymphoid tumor cell lines or mouse xenograft models can boost the cytotoxic effects of both conventional chemotherapeutics and novel agents, similar to heat-shock protein 90, proteasome and tyrosine kinases inhibitors. In this review, we summarize the evidence indicating how CK2 embodies most of the features of a cancer growth-promoting non-oncogene, focusing on lymphoid tumors. We further discuss the preclinical data of the use of small ATP-competitive CK2 inhibitors, which hold the promise to be additional options in novel drug

  14. Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion.

    OpenAIRE

    Vanni, Cristina; Ognibene, Marzia; Finetti, Federica; Mancini, Patrizia; Cabodi, Sara; Segalerba, Daniela; Torrisi, Maria Rosaria; Donnini, Sandra; Bosco, Maria Carla; Varesio, Luigi; Eva, Alessandra

    2015-01-01

    The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and ind...

  15. Mislocalized activation of oncogenic RTKs switches downstream signaling outcomes

    DEFF Research Database (Denmark)

    Choudhary, Chuna Ram; Olsen, Jesper V; Brandts, Christian

    2009-01-01

    Inappropriate activation of oncogenic kinases at intracellular locations is frequently observed in human cancers, but its effects on global signaling are incompletely understood. Here, we show that the oncogenic mutant of Flt3 (Flt3-ITD), when localized at the endoplasmic reticulum (ER), aberrant...

  16. Oncogenic Transformation of Human-Derived Gastric Organoids.

    Science.gov (United States)

    Bertaux-Skeirik, Nina; Centeno, Jomaris; Gao, Jian; Gabre, Joel; Zavros, Yana

    2016-08-19

    The culture of organoids has represented a significant advancement in the gastrointestinal research field. Previous research studies have described the oncogenic transformation of human intestinal and mouse gastric organoids. Here we detail the protocol for the oncogenic transformation and orthotopic transplantation of human-derived gastric organoids.

  17. Enhancer hijacking activates GFI1 family oncogenes in medulloblastoma.

    Science.gov (United States)

    Northcott, Paul A; Lee, Catherine; Zichner, Thomas; Stütz, Adrian M; Erkek, Serap; Kawauchi, Daisuke; Shih, David J H; Hovestadt, Volker; Zapatka, Marc; Sturm, Dominik; Jones, David T W; Kool, Marcel; Remke, Marc; Cavalli, Florence M G; Zuyderduyn, Scott; Bader, Gary D; VandenBerg, Scott; Esparza, Lourdes Adriana; Ryzhova, Marina; Wang, Wei; Wittmann, Andrea; Stark, Sebastian; Sieber, Laura; Seker-Cin, Huriye; Linke, Linda; Kratochwil, Fabian; Jäger, Natalie; Buchhalter, Ivo; Imbusch, Charles D; Zipprich, Gideon; Raeder, Benjamin; Schmidt, Sabine; Diessl, Nicolle; Wolf, Stephan; Wiemann, Stefan; Brors, Benedikt; Lawerenz, Chris; Eils, Jürgen; Warnatz, Hans-Jörg; Risch, Thomas; Yaspo, Marie-Laure; Weber, Ursula D; Bartholomae, Cynthia C; von Kalle, Christof; Turányi, Eszter; Hauser, Peter; Sanden, Emma; Darabi, Anna; Siesjö, Peter; Sterba, Jaroslav; Zitterbart, Karel; Sumerauer, David; van Sluis, Peter; Versteeg, Rogier; Volckmann, Richard; Koster, Jan; Schuhmann, Martin U; Ebinger, Martin; Grimes, H Leighton; Robinson, Giles W; Gajjar, Amar; Mynarek, Martin; von Hoff, Katja; Rutkowski, Stefan; Pietsch, Torsten; Scheurlen, Wolfram; Felsberg, Jörg; Reifenberger, Guido; Kulozik, Andreas E; von Deimling, Andreas; Witt, Olaf; Eils, Roland; Gilbertson, Richard J; Korshunov, Andrey; Taylor, Michael D; Lichter, Peter; Korbel, Jan O; Wechsler-Reya, Robert J; Pfister, Stefan M

    2014-07-24

    Medulloblastoma is a highly malignant paediatric brain tumour currently treated with a combination of surgery, radiation and chemotherapy, posing a considerable burden of toxicity to the developing child. Genomics has illuminated the extensive intertumoral heterogeneity of medulloblastoma, identifying four distinct molecular subgroups. Group 3 and group 4 subgroup medulloblastomas account for most paediatric cases; yet, oncogenic drivers for these subtypes remain largely unidentified. Here we describe a series of prevalent, highly disparate genomic structural variants, restricted to groups 3 and 4, resulting in specific and mutually exclusive activation of the growth factor independent 1 family proto-oncogenes, GFI1 and GFI1B. Somatic structural variants juxtapose GFI1 or GFI1B coding sequences proximal to active enhancer elements, including super-enhancers, instigating oncogenic activity. Our results, supported by evidence from mouse models, identify GFI1 and GFI1B as prominent medulloblastoma oncogenes and implicate 'enhancer hijacking' as an efficient mechanism driving oncogene activation in a childhood cancer.

  18. Oncogene K-Ras Affects the Processing of Amyloid Precursor Protein (APP) Through Regulating Its Phosphorylation at Thr668%原癌基因K-Ras调控APPThr668位点磷酸化及APP的切割

    Institute of Scientific and Technical Information of China (English)

    刘杨; 杨龙雨; 谢勇壮; 张弦; 许华曦; 张云武

    2012-01-01

    The expression of Ras is elevated during early stages of Alzheimer's disease. Here we investigated the effect of K-Ras on the processing of amyloid precursor protein (APP). The results showed that overexpression of K-Ras and its constitutively active mutant K-RasG12V could activate ERK1/2 and JNK pathways and induced phosphorylation of APP at"ftr668. While inhibition of the JNK pathway blocked the phosphorylation of APP. In addition, overexpression of K-Ras reduced the levels of sAPPf) and increased the levels of sAPPa but had no effect on the levels of AD AMI 0 and BACE1. Through biptin labeling experiment, we demonstrated that overexpression of K-Ras increased cell surface levels of APP without affecting the levels of tptal APP. Together, these results suggest that K-Ras can regulate APP phosphorylation and APP trafficking for its processing through the JNK pathway, implying that K-Ras may be a new target/pathway for regulating AD pathologies.%在阿尔茨海默症(Alzheimer's disease,AD)发病的早期,Ras蛋白所在的信号通路被激活,但具体作用机制还不清楚.探讨了K-Ras及其突变体K-RasG12V对淀粉样前体蛋白(amyloid precursor protein,APP)的剪切的影响.Western blot结果显示,过量表达K-Ras能够激活细胞外调节蛋白激酶1/2(extracellular signal-regulated kinase,ERK 1/2)、c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)通路,并增加APP在Thr668的磷酸化;抑制JNK通路则阻断了K-Ras过表达所引起的APP Thr668磷酸化.此外,过表达K-Ras造成分泌到细胞外的sAPPα增加,而sAPPβ减少.通过生物素标记实验发现,过表达K-Ras使得APP在细胞膜上的定位增加,而细胞内APP总量没有改变.这些结果表明,过量表达K-Ras可以通过调控JNK的通路,增加APP在Thr668位点的磷酸化,造成APP在细胞膜上水平升高,导致APP向sAPPβ的切割减少,而向sAPPα的切割增加.提示K-Ras对APP切割的影响可能在AD的发病过程中起着一定的应激作用.

  19. Expression Profiling of Circulating Microvesicles Reveals Intercellular Transmission of Oncogenic Pathways.

    Science.gov (United States)

    Milani, Gloria; Lana, Tobia; Bresolin, Silvia; Aveic, Sanja; Pastò, Anna; Frasson, Chiara; Te Kronnie, Geertruy

    2017-06-01

    Circulating microvesicles have been described as important players in cell-to-cell communication carrying biological information under normal or pathologic condition. Microvesicles released by cancer cells may incorporate diverse biomolecules (e.g., active lipids, proteins, and RNA), which can be delivered and internalized by recipient cells, potentially altering the gene expression of recipient cells and eventually impacting disease progression. Leukemia in vitro model systems were used to investigate microvesicles as vehicles of protein-coding messages. Several leukemic cells (K562, LAMA-87, TOM-1, REH, and SHI-1), each carrying a specific chromosomal translocation, were analyzed. In the leukemic cells, these chromosomal translocations are transcribed into oncogenic fusion transcripts and the transfer of these transcripts was monitored from leukemic cells to microvesicles for each of the cell lines. Microarray gene expression profiling was performed to compare transcriptomes of K562-derived microvesicles and parental K562 cells. The data show that oncogenic BCR-ABL1 transcripts and mRNAs related to basic functions of leukemic cells were included in microvesicles. Further analysis of microvesicles cargo revealed a remarkable enrichment of transcripts related to cell membrane activity, cell surface receptors, and extracellular communication when compared with parental K562 cells. Finally, coculturing of healthy mesenchymal stem cells (MSC) with K562-derived microvesicles displayed the transfer of the oncogenic message, and confirmed the increase of target cell proliferation as a function of microvesicle dosage.Implications: This study provides novel insight into tumor-derived microvesicles as carriers of oncogenic protein-coding messages that can potentially jeopardize cell-directed therapy, and spread to other compartments of the body. Mol Cancer Res; 15(6); 683-95. ©2017 AACR. ©2017 American Association for Cancer Research.

  20. Noxa induces apoptosis in oncogene-expressing cells through catch-and-release mechanism operating between Puma and Mcl-1.

    Science.gov (United States)

    Nakajima, Wataru; Tanaka, Nobuyuki

    2011-10-07

    Tumor suppressor p53 induces apoptosis by transcriptional induction of Noxa and Puma, which encode the proapoptotic BH3-only member of the Bcl-2 family proteins. In the p53-mediated tumor surveillance system, p53 induces apoptosis or replicative senescence in oncogene-expressing cells, resulting in elimination of such cells. In this context, we previously found that Noxa and Puma synergistically induce apoptosis. Here, we found the adenovirus oncogene E1A to induce p53-dependently expression of Puma, but not Noxa. The induced Puma associates with antiapoptotic Bcl-2 protein Mcl-1, accompanied by accumulated Mcl-1 protein on mitochondria. Moreover, E1A also reduces expression of the antiapoptotic Bcl-2 protein Bcl-X(L). In contrast, the DNA-damaging agent adriamycin induces Noxa expression in E1A-expressing cells. Interestingly, Mcl-1 knockdown itself induced apoptosis in E1A-expressing MEFs. Furthermore, Noxa displaced Puma's association with Mcl-1, accompanied by Mcl-1 degradation and apoptosis induction by activating mitochondrial apoptotic executers Bax and Bak. These results suggest that p53-induced apoptosis in oncogene-expressing cells is regulated by differential induction and sequential activation of Noxa and Puma. Accumulated Puma by oncogene enhances susceptibility to apoptosis through "catch" in mitochondria by Mcl-1. Subsequently, in response to DNA-damage, Noxa efficiently induces apoptosis by "release" of Puma from Mcl-1.

  1. Proteomic investigation in A549 lung cell line stably infected by HPV16E6/E7 oncogenes.

    Science.gov (United States)

    Ciotti, Marco; Marzano, Valeria; Giuliani, Laura; Nuccetelli, Marzia; D'Aguanno, Simona; Azzimonti, Barbara; Bernardini, Sergio; Perno, Carlo Federico; Urbani, Andrea; Favalli, Cartesio; Federici, Giorgio

    2009-01-01

    Data have accumulated implicating the involvement of oncogenic human papillomaviruses (HPVs) in bronchial carcinogenesis. We recently described the presence of oncogenic HPV transcripts in non-small cell lung cancers. To investigate the role of oncogenic HPVs in lung carcinogenesis. The lung cell line A549 stably infected with HPV16E6, HPV16E7 and HPVE6/E7 constructs was used to investigate the protein profile changes associated with the expression of these oncogenes. Replicated two-dimensional gel electrophoresis gels from uninfected and stably HPV16E6-, E7-, and E6/E7-infected A549 cells were compared for changes in protein profile. Protein identification was achieved by peptide mass fingerprinting by MALDI-TOF-MS and nLC-ESI-Q-TOF-MS/MS peptide ladder sequencing. We identified 17 different polypeptides whose average normalized spot intensity was statistically significant (p < 0.05) and differed by 2-fold. Relationships between differentially expressed proteins and the HPV-induced infection mechanism have been clustered by knowledge-base database functional association network analysis. The impact of Hsp27, annexin III, annexin IV, Gp96 and TPT1 on the cellular response mechanism to HPV infection is presented and discussed. Copyright 2008 S. Karger AG, Basel.

  2. Sensitivity of acute myeloid leukemia Kasumi-1 cells to binase toxic action depends on the expression of KIT and АML1-ETO oncogenes.

    Science.gov (United States)

    Mitkevich, Vladimir A; Petrushanko, Irina Y; Spirin, Pavel V; Fedorova, Tatiana V; Kretova, Olga V; Tchurikov, Nickolai A; Prassolov, Vladimir S; Ilinskaya, Olga N; Makarov, Alexander A

    2011-12-01

    Some RNases selectively attack malignant cells, triggering an apoptotic response, and therefore are considered as alternative chemotherapeutic drugs. Here we studied the effects of Bacillus intermedius RNase (binase) on murine myeloid progenitor cells FDC-P1; transduced FDC-P1 cells ectopically expressing mutated human KIT N822K oncogene and/or human AML1-ETO oncogene; and human leukemia Kasumi-1 cells expressing both of these oncogenes. Expression of both KIT and AML1-ETO oncogenes makes FDC-P1 cells sensitive to the toxic effects of binase. Kasumi-1 cells were the most responsive to the toxic actions of binase among the cell lines used in this work with an IC50 value of 0.56 µM. Either blocking the functional activity of the KIT protein with imatinib or knocking-down oncogene expression using lentiviral vectors producing shRNA against AML1-ETO or KIT eliminated the sensitivity of Kasumi-1 cells to binase toxic action and promoted their survival, even in the absence of KIT-dependent proliferation and antiapoptotic pathways. Here we provide evidence that the cooperative effect of the expression of mutated KIT and AML1-ETO oncogenes is crucial for selective toxic action of binase on malignant cells. These findings can facilitate clinical applications of binase providing a useful screen based on the presence of the corresponding target oncogenes in malignant cells.

  3. The Exceptional Oncogenicity of HTLV-1.

    Science.gov (United States)

    Tagaya, Yutaka; Gallo, Robert C

    2017-01-01

    Human T-cell leukemia virus-1 (HTLV-1) is the first pathogenic human retrovirus identified in 1979 by the Gallo group. HTLV-1 causes fatal T-cell leukemia (adult T cell leukemia) and a progressive myelopahy (HTLV-1-associated myelopathy/ tropical spastic paraparesis, HAM/TSP) and other disorders. Since the discovery of HTLV-1, several other microorganisms are demonstrated to cause cancer in humans. In this article, we investigated the oncogenic capacity of HTLV-1, in comparison with those of other oncoviruses and one oncobacterium (Helicobacter pylori, H. Pylori) based on published literature. We conclude here that HTLV-1 is one of the most and may be the most carcinogenic among them and arguably one of the most potent of the known human carcinogens. This fact has not been noted before and is particularly important to justify why we need to study HTLV-1 as an important model of human viral oncogenesis.

  4. Glycerophospholipid profile in oncogene-induced senescence.

    Science.gov (United States)

    Cadenas, Cristina; Vosbeck, Sonja; Hein, Eva-Maria; Hellwig, Birte; Langer, Alice; Hayen, Heiko; Franckenstein, Dennis; Büttner, Bettina; Hammad, Seddik; Marchan, Rosemarie; Hermes, Matthias; Selinski, Silvia; Rahnenführer, Jörg; Peksel, Begüm; Török, Zsolt; Vígh, László; Hengstler, Jan G

    2012-09-01

    Alterations in lipid metabolism and in the lipid composition of cellular membranes are linked to the pathology of numerous diseases including cancer. However, the influence of oncogene expression on cellular lipid profile is currently unknown. In this work we analyzed changes in lipid profiles that are induced in the course of ERBB2-expression mediated premature senescence. As a model system we used MCF-7 breast cancer cells with doxycycline-inducible expression of NeuT, an oncogenic ERBB2 variant. Affymetrix gene array data showed NeuT-induced alterations in the transcription of many enzymes involved in lipid metabolism, several of which (ACSL3, CHPT1, PLD1, LIPG, MGLL, LDL and NPC1) could be confirmed by quantitative realtime PCR. A study of the glycerophospholipid and lyso-glycerophospholipid profiles, obtained by high performance liquid chromatography coupled to Fourier-transform ion cyclotron resonance-mass spectrometry revealed senescence-associated changes in numerous lipid species, including mitochondrial lipids. The most prominent changes were found in PG(34:1), PG(36:1) (increased) and LPE(18:1), PG(40:7) and PI(36:1) (decreased). Statistical analysis revealed a general trend towards shortened phospholipid acyl chains in senescence and a significant trend to more saturated acyl chains in the class of phosphatidylglycerol. Additionally, the cellular cholesterol content was elevated and accumulated in vacuoles in senescent cells. These changes were accompanied by increased membrane fluidity. In mitochondria, loss of membrane potential along with altered intracellular distribution was observed. In conclusion, we present a comprehensive overview of altered cholesterol and glycerophospholipid patterns in senescence, showing that predominantly mitochondrial lipids are affected and lipid species less susceptible to peroxidation are increased.

  5. RECQL4 helicase has oncogenic potential in sporadic breast cancers.

    Science.gov (United States)

    Arora, Arvind; Agarwal, Devika; Abdel-Fatah, Tarek Ma; Lu, Huiming; Croteau, Deborah L; Moseley, Paul; Aleskandarany, Mohammed A; Green, Andrew R; Ball, Graham; Rakha, Emad A; Chan, Stephen Yt; Ellis, Ian O; Wang, Lisa L; Zhao, Yongliang; Balajee, Adayabalam S; Bohr, Vilhelm A; Madhusudan, Srinivasan

    2016-03-01

    RECQL4 helicase is a molecular motor that unwinds DNA, a process essential during DNA replication and DNA repair. Germ-line mutations in RECQL4 cause type II Rothmund-Thomson syndrome (RTS), characterized by a premature ageing phenotype and cancer predisposition. RECQL4 is widely considered to be a tumour suppressor, although its role in human breast cancer is largely unknown. As the RECQL4 gene is localized to chromosome 8q24, a site frequently amplified in sporadic breast cancers, we hypothesized that it may play an oncogenic role in breast tumourigenesis. To address this, we analysed large cohorts for gene copy number changes (n = 1977), mRNA expression (n = 1977) and protein level (n = 1902). Breast cancer incidence was also explored in 58 patients with type II RTS. DNA replication dynamics and chemosensitivity was evaluated in RECQL4-depleted breast cancer cells in vitro. Amplification or gain in gene copy number (30.6%), high-level mRNA expression (51%) and high levels of protein (23%) significantly associated with aggressive tumour behaviour, including lymph node positivity, larger tumour size, HER2 overexpression, ER-negativity, triple-negative phenotypes and poor survival. RECQL4 depletion impaired the DNA replication rate and increased chemosensitivity in cultured breast cancer cells. Thus, although recognized as a 'safe guardian of the genome', our data provide compelling evidence that RECQL4 is tumour promoting in established breast cancers. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  6. Identification of ALV-J associated acutely transforming virus Fu-J carrying complete v-fps oncogene.

    Science.gov (United States)

    Wang, Yixin; Li, Jianliang; Li, Yang; Fang, Lichun; Sun, Xiaolong; Chang, Shuang; Zhao, Peng; Cui, Zhizhong

    2016-06-01

    Transduction of oncogenes by ALVs and generation of acute transforming viruses is common in natural viral infections. In order to understand the molecular basis for the rapid oncogenicity of Fu-J, an acutely transforming avian leukosis virus isolated from fibrosarcomas in crossbreed broilers infected with subgroup J avian leukosis virus (ALV-J) in China, complete genomic structure of Fu-J virus was determined by PCR amplification and compared with those of Fu-J1, Fu-J2, Fu-J3, Fu-J4, and Fu-J5 reported previously. The results showed that the genome of Fu-J was defective, with parts of gag gene replaced by the complete v-fps oncogene and encoded a 137 kDa Gag-fps fusion protein. Sequence analysis revealed that Fu-J and Fu-J1 to Fu-J5 were related quasi-species variants carrying different lengths of v-fps oncogenes generated from recombination between helper virus and c-fps gene. Comparison of virus carrying v-fps oncogene also gave us a glimpse of the molecular characterization and evolution process of the acutely transforming ALV.

  7. Characterization of a human cell line stably over-expressing the candidate oncogene, dual specificity phosphatase 12.

    Directory of Open Access Journals (Sweden)

    Erica L Cain

    Full Text Available BACKGROUND: Analysis of chromosomal rearrangements within primary tumors has been influential in the identification of novel oncogenes. Identification of the "driver" gene(s within cancer-derived amplicons is, however, hampered by the fact that most amplicons contain many gene products. Amplification of 1q21-1q23 is strongly associated with liposarcomas and microarray-based comparative genomic hybridization narrowed down the likely candidate oncogenes to two: the activating transcription factor 6 (atf6 and the dual specificity phosphatase 12 (dusp12. While atf6 is an established transcriptional regulator of the unfolded protein response, the potential role of dusp12 in cancer remains uncharacterized. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate the oncogenic potential of dusp12, we established stable cell lines that ectopically over-express dusp12 in isolation and determined whether this cell line acquired properties frequently associated with transformed cells. Here, we demonstrate that cells over-expressing dusp12 display increased cell motility and resistance to apoptosis. Additionally, over-expression of dusp12 promoted increased expression of the c-met proto-oncogene and the collagen and laminin receptor intergrin alpha 1 (itga1 which is implicated in metastasis. SIGNIFICANCE: Collectively, these results suggest that dusp12 is oncologically relevant and exposes a potential association between dusp12 and established oncogenes that could be therapeutically targeted.

  8. Two oncogenes, v-fos and v-ras, cooperate to convert normal keratinocytes to squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Greenhalgh, D.A.; Welty, D.J.; Player, A.; Yuspa, S.H. (National Cancer Institute, Bethesda, MD (USA))

    1990-01-01

    Previous studies have been implicated the ras{sup Ha} oncogene in the initiation of skin carcinogenesis and the fos oncogene in malignant progression of premalignant skin cell lines. To determine if these two oncogenes are sufficient to convert normal keratinocytes to cancer cells, freshly isolated mouse keratinocytes were coinfected with replication-defective ({psi}-2) v-ras{sup Ha} and v-fos viruses in culture. When tested in nude mice within several days of infection, v-fos/v-ras{sup Ha}-coinfected keratinocytes produced squamous cell carcinomas. Introduction of v-fos alone resulted in normal or hyperplastic skin, whereas v-ras{sup Ha} alone produced squamous papillomas. These results indicate that two oncogenes are sufficient to produce the malignant phenotype in epidermal cells. Furthermore, they clearly link the fos oncogene with malignant conversion. Since fos acts as a transcriptional regulator of other genes, malignant conversion may be an indirect consequence of the overexpression of the fos-encoded protein leading to a change in the expression of fos-controlled cellular genes.

  9. A posttranslational modification cascade involving p38, Tip60, and PRAK mediates oncogene-induced senescence.

    Science.gov (United States)

    Zheng, Hui; Seit-Nebi, Alim; Han, Xuemei; Aslanian, Aaron; Tat, John; Liao, Rong; Yates, John R; Sun, Peiqing

    2013-06-06

    Oncogene-induced senescence is an important tumor-suppressing defense mechanism. However, relatively little is known about the signaling pathway mediating the senescence response. Here, we demonstrate that a multifunctional acetyltransferase, Tip60, plays an essential role in oncogenic ras-induced senescence. Further investigation reveals a cascade of posttranslational modifications involving p38, Tip60, and PRAK, three proteins that are essential for ras-induced senescence. Upon activation by ras, p38 induces the acetyltransferase activity of Tip60 through phosphorylation of Thr158; activated Tip60 in turn directly interacts with and induces the protein kinase activity of PRAK through acetylation of K364 in a manner that depends on phosphorylation of both Tip60 and PRAK by p38. These posttranslational modifications are critical for the prosenescent function of Tip60 and PRAK, respectively. These results have defined a signaling pathway that mediates oncogene-induced senescence, and identified posttranslational modifications that regulate the enzymatic activity and biological functions of Tip60 and PRAK.

  10. Transgenic expression of oncogenic BRAF induces loss of stem cells in the mouse intestine, which is antagonized by β-catenin activity.

    Science.gov (United States)

    Riemer, P; Sreekumar, A; Reinke, S; Rad, R; Schäfer, R; Sers, C; Bläker, H; Herrmann, B G; Morkel, M

    2015-06-11

    Colon cancer cells frequently carry mutations that activate the β-catenin and mitogen-activated protein kinase (MAPK) signaling cascades. Yet how oncogenic alterations interact to control cellular hierarchies during tumor initiation and progression is largely unknown. We found that oncogenic BRAF modulates gene expression associated with cell differentiation in colon cancer cells. We therefore engineered a mouse with an inducible oncogenic BRAF transgene, and analyzed BRAF effects on cellular hierarchies in the intestinal epithelium in vivo and in primary organotypic culture. We demonstrate that transgenic expression of oncogenic BRAF in the mouse strongly activated MAPK signal transduction, resulted in the rapid development of generalized serrated dysplasia, but unexpectedly also induced depletion of the intestinal stem cell (ISC) pool. Histological and gene expression analyses indicate that ISCs collectively converted to short-lived progenitor cells after BRAF activation. As Wnt/β-catenin signals encourage ISC identity, we asked whether β-catenin activity could counteract oncogenic BRAF. Indeed, we found that intestinal organoids could be partially protected from deleterious oncogenic BRAF effects by Wnt3a or by small-molecule inhibition of GSK3β. Similarly, transgenic expression of stabilized β-catenin in addition to oncogenic BRAF partially prevented loss of stem cells in the mouse intestine. We also used BRAF(V637E) knock-in mice to follow changes in the stem cell pool during serrated tumor progression and found ISC marker expression reduced in serrated hyperplasia forming after BRAF activation, but intensified in progressive dysplastic foci characterized by additional mutations that activate the Wnt/β-catenin pathway. Our study suggests that oncogenic alterations activating the MAPK and Wnt/β-catenin pathways must be consecutively and coordinately selected to assure stem cell maintenance during colon cancer initiation and progression. Notably, loss of

  11. A "liaison dangereuse" between AUF1/hnRNPD and the oncogenic tyrosine kinase NPM-ALK.

    Science.gov (United States)

    Fawal, Mohamad; Armstrong, Florence; Ollier, Severine; Dupont, Henri; Touriol, Christian; Monsarrat, Bernard; Delsol, Georges; Payrastre, Bernard; Morello, Dominique

    2006-10-15

    Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) is a chimeric protein expressed in a subset of cases of anaplastic large cell lymphoma (ALCL) for which constitutive expression represents a key oncogenic event. The ALK signaling pathway is complex and probably involves functional redundancy between various signaling substrates of ALK. Despite numerous studies on signaling mediators, the molecular mechanisms contributing to the distinct oncogenic features of NPM-ALK remain incompletely understood. The search for additional interacting partners of NPM-ALK led to the discovery of AUF1/hnRNPD, a protein implicated in AU-rich element (ARE)-directed mRNA decay. AUF1 was immunoprecipitated with ALK both in ALCL-derived cells and in NIH3T3 cells stably expressing NPM-ALK or other X-ALK fusion proteins. AUF1 and NPM-ALK were found concentrated in the same cytoplasmic foci, whose formation required NPM-ALK tyrosine kinase activity. AUF1 was phosphorylated by ALK in vitro and was hyperphosphorylated in NPM-ALK-expressing cells. Its hyperphosphorylation was correlated with increased stability of several AUF1 target mRNAs encoding key regulators of cell proliferation and with increased cell survival after transcriptional arrest. Thus, AUF1 could function in a novel pathway mediating the oncogenic effects of NPM-ALK. Our data establish an important link between oncogenic kinases and mRNA turnover, which could constitute a critical aspect of tumorigenesis.

  12. Dbl oncogene expression in MCF-10 A epithelial cells disrupts mammary acinar architecture, induces EMT and angiogenic factor secretion.

    Science.gov (United States)

    Vanni, Cristina; Ognibene, Marzia; Finetti, Federica; Mancini, Patrizia; Cabodi, Sara; Segalerba, Daniela; Torrisi, Maria Rosaria; Donnini, Sandra; Bosco, Maria Carla; Varesio, Luigi; Eva, Alessandra

    2015-01-01

    The proteins of the Dbl family are guanine nucleotide exchange factors (GEFs) of Rho GTPases and are known to be involved in cell growth regulation. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders, neoplastic transformation, and tumor metastasis. We have previously demonstrated that expression of Dbl oncogene in lens epithelial cells modulates genes encoding proteins involved in epithelial-mesenchymal-transition (EMT) and induces angiogenesis in the lens. Our present study was undertaken to investigate the role of Dbl oncogene in epithelial cells transformation, providing new insights into carcinoma progression.To assess how Dbl oncogene can modulate EMT, cell migration, morphogenesis, and expression of pro-apoptotic and angiogenic factors we utilized bi- and 3-dimensional cultures of MCF-10 A cells. We show that upon Dbl expression MCF-10 A cells undergo EMT. In addition, we found that Dbl overexpression sustains Cdc42 and Rac activation inducing morphological alterations, characterized by the presence of lamellipodia and conferring a high migratory capacity to the cells. Moreover, Dbl expressing MCF-10 A cells form altered 3D structures and can induce angiogenesis by producing proangiogenic factors such as CCL2. These results support a role for Dbl oncogene in epithelial cell differentiation and transformation and suggest the relevance of GEF deregulation in tumor onset and progression.

  13. The oncogenic action of ionizing radiation on rat skin

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.J.

    1991-01-01

    Progress has occurred in several areas corresponding to the specific aims of the proposal: (1) Progression and multiple events in radiation carcinogenesis of rat skin as a function of LET; (2) cell cycle kinetics of irradiated rat epidermis as determined by double labeling and double emulsion autoradiography; (3) oncogene activation detected by in situ hybridization in radiation-induced rat skin tumors; (4) amplification of the c-myc oncogene in radiation-induced rat skin tumors as a function of LET; and (5) transformation of rat skin keratinocytes by ionizing radiation in combination with c-Ki-ras and c-myc oncogenes. 111 refs., 13 figs., 12 tabs.

  14. The Oncogenic Palmitoyl-Protein Network in Prostate Cancer

    Science.gov (United States)

    2013-03-01

    response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and... reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information...formation, secretion, and activity of oncosomes. We recently developed the technology to separate large oncosome EVs from small EVs ( exosomes ). In a

  15. A novel MCF-10A line allowing conditional oncogene expression in 3D culture

    Directory of Open Access Journals (Sweden)

    Danke Christina

    2011-07-01

    Full Text Available Introduction Non-transformed mammary epithelial cell lines such as MCF-10A recapitulate epithelial morphogenesis in three-dimensional (3D tissue culture by forming acinar structures. They represent an important tool to characterize the biological properties of oncogenes and to model early carcinogenic events. So far, however, these approaches were restricted to cells with constitutive oncogene expression prior to the set-up of 3D cultures. Although very informative, this experimental setting has precluded the analysis of effects caused by sudden oncoprotein expression or withdrawal in established epithelial cultures. Here, we report the establishment and use of a stable MCF-10A cell line (MCF-10Atet fitted with a novel and improved doxycycline (dox-regulated expression system allowing the conditional expression of any transgene. Methods MCF-10Atet cells were generated by stable transfection with pWHE644, a vector expressing a second generation tetracycline-regulated transactivator and a novel transcriptional silencer. In order to test the properties of this new repressor/activator switch, MCF-10Atet cells were transfected with a second plasmid, pTET-HABRAF-IRES-GFP, which responds to dox treatment with the production of a bi-cistronic transcript encoding hemagglutinin-tagged B-Raf and green fluorescent protein (GFP. This improved conditional expression system was then characterized in detail in terms of its response to various dox concentrations and exposure times. The plasticity of the phenotype provoked by oncogenic B-RafV600E in MCF-10Atet cells was analyzed in 3D cultures by dox exposure and subsequent wash-out. Results MCF-10Atet cells represent a tightly controlled, conditional gene expression system. Using B-RafV600E as a model oncoprotein, we show that its sudden expression in established 3D cultures results in the loss of acinar organization, the induction of an invasive phenotype and hallmarks of epithelial-to-mesenchymal transition

  16. BCL3 exerts an oncogenic function by regulating STAT3 in human cervical cancer

    Directory of Open Access Journals (Sweden)

    Zhao H

    2016-10-01

    Full Text Available Hu Zhao,1 Wuliang Wang,1 Qinghe Zhao,1 Guiming Hu,2 Kehong Deng,1 Yuling Liu1 1Department of Gynecology and Obstetrics, 2Department of Pathology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, People’s Republic of China Abstract: Aberrant expression of oncogenes and/or tumor suppressors play a fundamental effect on the pathogenesis and tumorigenicity of cervical cancer (CC. B-cell CLL/lymphoma 3 (BCL3 was previously found to be a putative proto-oncogene in human cancers and regulated signal transducer and activator of transcription 3 (STAT3, a critical oncogene, in CC cell line. However, its expression status, clinical significance and biological functions in CC remain largely unclear. The expressions of BCL3 and STAT3 in CC specimens were determined by immunohistochemistry. MTT, colony formation assays and flow cytometry analysis were carried out to test proliferation and cell cycle of CC cells. Here, the levels of BCL3 were overexpressed in CC compared to adjacent cervical tissues. Furthermore, high levels of BCL3 protein were confirmed by immunoblotting in CC cells as compared with normal cervical epithelial cells. The positive expression of BCL3 was correlated with adverse prognostic features and reduced survival rate. In addition, BCL3 regulated STAT3 abundance in CC cells. STAT3 was found to be upregulated and positively correlated with BCL3 expression in CC specimens. BCL3 overexpression resulted in prominent increased proliferation and cell cycle progression in Hela cells. By contrast, inhibition of BCL3 in CaSki cells remarkably suppressed proliferative ability and cell cycle progression. In vivo studies showed that knockdown of BCL3 inhibited tumor growth of CC in mice xenograft model. Notably, we confirmed that STAT3 mediated the oncogenic roles of BCL3 in CC. In conclusion, we suggest that BCL3 serves as an oncogene in CC by modulating proliferation and cell cycle progression, and its oncogenic effect is

  17. Oncogenic potential diverge among human papillomavirus type 16 natural variants

    Energy Technology Data Exchange (ETDEWEB)

    Sichero, Laura, E-mail: lsichero@gmail.com [Molecular Biology Laboratory, Center of Translational Oncology, Instituto do Cancer do Estado de Sao Paulo-ICESP, Sao Paulo 01246-000 (Brazil); Department of Virology, Ludwig Institute for Cancer Research, Sao Paulo 01323-903 (Brazil); Simao Sobrinho, Joao [Molecular Biology Laboratory, Center of Translational Oncology, Instituto do Cancer do Estado de Sao Paulo-ICESP, Sao Paulo 01246-000 (Brazil); Department of Virology, Ludwig Institute for Cancer Research, Sao Paulo 01323-903 (Brazil); Lina Villa, Luisa [Molecular Biology Laboratory, Center of Translational Oncology, Instituto do Cancer do Estado de Sao Paulo-ICESP, Sao Paulo 01246-000 (Brazil); Department of Virology, Ludwig Institute for Cancer Research, Sao Paulo 01323-903 (Brazil); Department of Radiology, School of Medicine, University of Sao Paulo (Brazil)

    2012-10-10

    We compared E6/E7 protein properties of three different HPV-16 variants: AA, E-P and E-350G. Primary human foreskin keratinocytes (PHFK) were transduced with HPV-16 E6 and E7 and evaluated for proliferation and ability to grow in soft agar. E-P infected keratinocytes presented the lowest efficiency in colony formation. AA and E-350G keratinocytes attained higher capacity for in vitro transformation. We observed similar degradation of TP53 among HPV-16 variants. Furthermore, we accessed the expression profile in early (p5) and late passage (p30) transduced cells of 84 genes commonly involved in carcinogenesis. Most differences could be attributed to HPV-16 E6/E7 expression. In particular, we detected different expression of ITGA2 and CHEK2 in keratinocytes infected with AA and AA/E-350G late passage cells, respectively, and higher expression of MAP2K1 in E-350G transduced keratinocytes. Our results indicate differences among HPV-16 variants that could explain, at least in part, differences in oncogenic potential attributed to these variants.

  18. Genetic and pharmacological suppression of oncogenic mutations in RAS genes of yeast and humans

    Energy Technology Data Exchange (ETDEWEB)

    Schafer, W.R.; Sterne, R.; Thorner, J.; Rine, J.; Kim, R.; Kim, S.H. (Lawrece Berkeley Lab., CA (USA))

    1989-07-28

    The activity of an oncoprotein and the secretion of a pheromone can be affected by an unusual protein modification. Specifically, posttranslational modification of yeast-a-factor and Ras protein requires an intermediate of the cholesterol biosynthetic pathway. This modification is apparently essential for biological activity. Studies of yeast mutants blocked in sterol biosynthesis demonstrated that the membrane association and biological activation of the yeast Ras2 protein require mevalonate, a precursor of sterols and other isoprenes such as farnesyl pyrophosphate. Furthermore, drugs that inhibit mevalonate biosynthesis blocked the in vivo action of oncogenic derivatives of human Ras protein in the Xenopus oocyte assay. The same drugs and mutations also prevented the posttranslational processing and secretion of yeast a-factor, a peptide that is farnesylated. Thus, the mevalonate requirement for Ras activation may indicate that attachment of a mevalonate-derived (isoprenoid) moiety to Ras proteins is necessary for membrane association and biological function. These observations establish a connection between the cholesterol biosynthetic pathway and transformation by the ras oncogene and offer a novel pharmacological approach to investigating, and possibly controlling, ras-mediated malignant transformations. 50 refs., 3 figs., 3 tabs.

  19. Transglutaminase 2 contributes to a TP53-induced autophagy program to prevent oncogenic transformation.

    Science.gov (United States)

    Yeo, Shi Yun; Itahana, Yoko; Guo, Alvin Kunyao; Han, Rachel; Iwamoto, Kozue; Nguyen, Hung Thanh; Bao, Yi; Kleiber, Kai; Wu, Ya Jun; Bay, Boon Huat; Voorhoeve, Mathijs; Itahana, Koji

    2016-03-09

    Genetic alterations which impair the function of the TP53 signaling pathway in TP53 wild-type human tumors remain elusive. To identify new components of this pathway, we performed a screen for genes whose loss-of-function debilitated TP53 signaling and enabled oncogenic transformation of human mammary epithelial cells. We identified transglutaminase 2 (TGM2) as a putative tumor suppressor in the TP53 pathway. TGM2 suppressed colony formation in soft agar and tumor formation in a xenograft mouse model. The depletion of growth supplements induced both TGM2 expression and autophagy in a TP53-dependent manner, and TGM2 promoted autophagic flux by enhancing autophagic protein degradation and autolysosome clearance. Reduced expression of both CDKN1A, which regulates the cell cycle downstream of TP53, and TGM2 synergized to promote oncogenic transformation. Our findings suggest that TGM2-mediated autophagy and CDKN1A-mediated cell cycle arrest are two important barriers in the TP53 pathway that prevent oncogenic transformation.

  20. The potent oncogene NPM-ALK mediates malignant transformation of normal human CD4(+) T lymphocytes.

    Science.gov (United States)

    Zhang, Qian; Wei, Fang; Wang, Hong Yi; Liu, Xiaobin; Roy, Darshan; Xiong, Qun-Bin; Jiang, Shuguang; Medvec, Andrew; Danet-Desnoyers, Gwenn; Watt, Christopher; Tomczak, Ewa; Kalos, Michael; Riley, James L; Wasik, Mariusz A

    2013-12-01

    With this study we have demonstrated that in vitro transduction of normal human CD4(+) T lymphocytes with NPM-ALK results in their malignant transformation. The transformed cells become immortalized and display morphology and immunophenotype characteristic of patient-derived anaplastic large-cell lymphomas. These unique features, which are strictly dependent on NPM-ALK activity and expression, include perpetual cell growth, proliferation, and survival; activation of the key signal transduction pathways STAT3 and mTORC1; and expression of CD30 (the hallmark of anaplastic large-cell lymphoma) and of immunosuppressive cytokine IL-10 and cell-surface protein PD-L1/CD274. Implantation of NPM-ALK-transformed CD4(+) T lymphocytes into immunodeficient mice resulted in formation of tumors indistinguishable from patients' anaplastic large-cell lymphomas. Our findings demonstrate that the key aspects of human carcinogenesis closely recapitulating the features of the native tumors can be faithfully reproduced in vitro when an appropriate oncogene is used to transform its natural target cells; this in turn points to the fundamental role in malignant cell transformation of potent oncogenes expressed in the relevant target cells. Such transformed cells should permit study of the early stages of carcinogenesis, and in particular the initial oncogene-host cell interactions. This experimental design could also be useful for studies of the effects of early therapeutic intervention and likely also the mechanisms of malignant progression.

  1. Oncogenic osteomalacia associated with soft tissue chondromyxoid fibroma

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Mi E-mail: jmpark@cmc.cuk.ac.kr; Woo, Young Kyun; Kang, Moo Il; Kang, Chang Suk; Hahn, Seong Tae

    2001-08-01

    Oncogenic osteomalacia is a rarely described clinical entity characterized by hypophosphatemia, phosphaturia, and a low concentration of 1,25-dihydroxyvitamin D{sub 3}. It is most often associated with benign mesenchymal tumor and can be cured with surgical removal of the tumor. In this paper, we present a case of oncogenic osteomalacia caused by chondromyxoid fibroma in the soft tissue of the sole of the foot in a 56-year-old woman.

  2. Identification of Novel Small Molecule Inhibitors of Oncogenic RET Kinase

    OpenAIRE

    Marialuisa Moccia; Qingsong Liu; Teresa Guida; Giorgia Federico; Annalisa Brescia; Zheng Zhao; Hwan Geun Choi; Xianming Deng; Li Tan; Jinhua Wang; Marc Billaud; Gray, Nathanael S.; Francesca Carlomagno; Massimo Santoro

    2015-01-01

    Oncogenic mutation of the RET receptor tyrosine kinase is observed in several human malignancies. Here, we describe three novel type II RET tyrosine kinase inhibitors (TKI), ALW-II-41-27, XMD15-44 and HG-6-63-01, that inhibit the cellular activity of oncogenic RET mutants at two digit nanomolar concentration. These three compounds shared a 3-trifluoromethyl-4-methylpiperazinephenyl pharmacophore that stabilizes the 'DFG-out' inactive conformation of RET activation loop. They blocked RET-media...

  3. Oncogenic KRAS triggers MAPK-dependent errors in mitosis and MYC-dependent sensitivity to anti-mitotic agents.

    Science.gov (United States)

    Perera, David; Venkitaraman, Ashok R

    2016-07-14

    Oncogenic KRAS induces cell proliferation and transformation, but little is known about its effects on cell division. Functional genetic screens have recently revealed that cancer cell lines expressing oncogenic KRAS are sensitive to interference with mitosis, but neither the mechanism nor the uniformity of anti-mitotic drug sensitivity connected with mutant KRAS expression are yet clear. Here, we report that acute expression of oncogenic KRAS in HeLa cells induces mitotic delay and defects in chromosome segregation through mitogen-activated protein kinase (MAPK) pathway activation and de-regulated expression of several mitosis-related genes. These anomalies are accompanied by increased sensitivity to anti-mitotic agents, a phenotype dependent on the transcription factor MYC and its downstream target anti-apoptotic protein BCL-XL. Unexpectedly, we find no correlation between KRAS mutational status or MYC expression levels and anti-mitotic drug sensitivity when surveying a large database of anti-cancer drug responses. However, we report that the co-existence of KRAS mutations and high MYC expression predicts anti-mitotic drug sensitivity. Our findings reveal a novel function of oncogenic KRAS in regulating accurate mitotic progression and suggest new avenues to therapeutically target KRAS-mutant tumours and stratify patients in ongoing clinical trials of anti-mitotic drugs.

  4. Altered Ca(2+) signaling in cancer cells: proto-oncogenes and tumor suppressors targeting IP3 receptors.

    Science.gov (United States)

    Akl, Haidar; Bultynck, Geert

    2013-04-01

    Proto-oncogenes and tumor suppressors critically control cell-fate decisions like cell survival, adaptation and death. These processes are regulated by Ca(2+) signals arising from the endoplasmic reticulum, which at distinct sites is in close proximity to the mitochondria. These organelles are linked by different mechanisms, including Ca(2+)-transport mechanisms involving the inositol 1,4,5-trisphosphate receptor (IP3R) and the voltage-dependent anion channel (VDAC). The amount of Ca(2+) transfer from the endoplasmic reticulum to mitochondria determines the susceptibility of cells to apoptotic stimuli. Suppressing the transfer of Ca(2+) from the endoplasmic reticulum to the mitochondria increases the apoptotic resistance of cells and may decrease the cellular responsiveness to apoptotic signaling in response to cellular damage or alterations. This can result in the survival, growth and proliferation of cells with oncogenic features. Clearly, proper maintenance of endoplasmic reticulum Ca(2+) homeostasis and dynamics including its links with the mitochondrial network is essential to detect and eliminate altered cells with oncogenic features through the apoptotic pathway. Proto-oncogenes and tumor suppressors exploit the central role of Ca(2+) signaling by targeting the IP3R. There are an increasing number of reports showing that activation of proto-oncogenes or inactivation of tumor suppressors directly affects IP3R function and endoplasmic reticulum Ca(2+) homeostasis, thereby decreasing mitochondrial Ca(2+) uptake and mitochondrial outer membrane permeabilization. In this review, we provide an overview of the current knowledge on the proto-oncogenes and tumor suppressors identified as IP3R-regulatory proteins and how they affect endoplasmic reticulum Ca(2+) homeostasis and dynamics.

  5. Inhibition of Ras oncogenic activity by Ras protooncogenes.

    Science.gov (United States)

    Diaz, Roberto; Lue, Jeffrey; Mathews, Jeremy; Yoon, Andrew; Ahn, Daniel; Garcia-España, Antonio; Leonardi, Peter; Vargas, Marcelo P; Pellicer, Angel

    2005-01-10

    Point mutations in ras genes have been found in a large number and wide variety of human tumors. These oncogenic Ras mutants are locked in an active GTP-bound state that leads to a constitutive and deregulated activation of Ras function. The dogma that ras oncogenes are dominant, whereby the mutation of a single allele in a cell will predispose the host cell to transformation regardless of the presence of the normal allele, is being challenged. We have seen that increasing amounts of Ras protooncogenes are able to inhibit the activity of the N-Ras oncogene in the activation of Elk in NIH 3T3 cells and in the formation of foci. We have been able to determine that the inhibitory effect is by competition between Ras protooncogenes and the N-Ras oncogene that occurs first at the effector level at the membranes, then at the processing level and lastly at the effector level in the cytosol. In addition, coexpression of the N-Ras protooncogene in thymic lymphomas induced by the N-Ras oncogene is associated with increased levels of p107, p130 and cyclin A and decreased levels of Rb. In the present report, we have shown that the N-Ras oncogene is not truly dominant over Ras protooncogenes and their competing activities might be depending on cellular context.

  6. CXCR4 in breast cancer: oncogenic role and therapeutic targeting

    Directory of Open Access Journals (Sweden)

    Xu C

    2015-08-01

    Full Text Available Chao Xu,1,* Hong Zhao,1,* Haitao Chen,1 Qinghua Yao2,3 1First Clinical College of Zhejiang Chinese Medical University, 2Department of Integrated Traditional Chinese and Western Medicine, Zhejiang Cancer Hospital, 3Key Laboratory of Integrated Traditional Chinese and Western Medicine, Zhejiang Cancer Hospital, Hangzhou, People’s Republic of China *These authors contributed equally to this work Abstract: Chemokines are 8–12 kDa peptides that function as chemoattractant cytokines and are involved in cell activation, differentiation, and trafficking. Chemokines bind to specific G-protein-coupled seven-span transmembrane receptors. Chemokines play a fundamental role in the regulation of a variety of cellular, physiological, and developmental processes. Their aberrant expression can lead to a variety of human diseases including cancer. C-X-C chemokine receptor type 4 (CXCR4, also known as fusin or CD184, is an alpha-chemokine receptor specific for stromal-derived-factor-1 (SDF-1 also called CXCL12. CXCR4 belongs to the superfamily of the seven transmembrane domain heterotrimeric G protein-coupled receptors and is functionally expressed on the cell surface of various types of cancer cells. CXCR4 also plays a role in the cell proliferation and migration of these cells. Recently, CXCR4 has been reported to play an important role in cell survival, proliferation, migration, as well as metastasis of several cancers including breast cancer. This review is mainly focused on the current knowledge of the oncogenic role and potential drugs that target CXCR4 in breast cancer. Additionally, CXCR4 proangiogenic molecular mechanisms will be reviewed. Strict biunivocal binding affinity and activation of CXCR4/CXCL12 complex make CXCR4 a unique molecular target for prevention and treatment of breast cancer. Keywords: breast cancer, CXCR4, drug target, chemokine, angiogenesis

  7. Gene mutation and protein expression of v-Raf murine sarcoma viral oncogene homolog B1 in esophageal cancer%食管癌中鼠类肉瘤滤过性毒菌致癌同源体B1基因的突变和蛋白质表达情况

    Institute of Scientific and Technical Information of China (English)

    刘广杰; 张浩然; 解少男; 李立哲; 刘芳; 刘庆熠

    2016-01-01

    目的 探讨食管癌中鼠类肉瘤滤过性毒菌致癌同源体B1 (BRAF)的基因突变和蛋白质表达情况.方法 纳入2014年2月至2015年9月接受手术治疗的75例食管癌患者,取其癌组织、近癌组织和远癌组织,检测BRAF基因的突变和BRAF蛋白质的表达情况,分析BRAF蛋白质阳性表达与食管癌患者临床病理特征的关系.计数资料比较采用卡方检验.结果 在食管癌组织中未检测到BRAF基因第11和15外显子存在突变.75份食管癌组织中,5份Ⅲb期标本在第11外显子上增加了1个碱基C或T.75份食管癌组织中,46份(61.3 %) BRAF蛋白质表达阳性;57份近癌组织中,9份(15.8%)BRAF蛋白质表达阳性;75份远癌组织中,5份(6.7%)BRAF蛋白质表达阳性;3组间比较差异有统计学意义(x2 =61.098,P<0.05).TNM分期Ⅰ、Ⅱ、Ⅲ期食管癌患者的BRAF蛋白质阳性率分别为21.7%(5/23)、70.8%(17/24)和85.7%(24/28),有和无淋巴结转移患者的BRAF蛋白质阳性率分别为81.6%(31/38)和40.5%(15/37);BRAF蛋白质表达阳性与TNM分期和肿瘤淋巴结转移有关(x2 =23.136、13.313,P均<0.01),与患者性别、年龄和肿瘤分化程度无关(P均>0.05).结论 食管癌组织中BRAF基因第11外显子上有碱基插入情况,但未见突变发生.BRAF蛋白质在食管癌中呈高表达,与TNM分期和淋巴结转移情况有关,可作为判断食管癌恶性程度和患者预后的指标.%Objective To estimate the gene mutation and the protein expression of v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) in esophageal cancer.Methods From February 2014 to September 2015,75 patients with esophageal cancer who received operation were enrolled.Tissues of cancer,adjacent to cancer and far from cancer were taken.The mutation and protein expression of BRAF were detected.The relationship between BRAF protein positive expression and clinical characteristics of patients with esophageal cancer was analyzed.The enumeration data

  8. Characterization of ERAS, a putative novel human oncogene, in skin and breast

    Energy Technology Data Exchange (ETDEWEB)

    Peña Avalos, B.L. de la

    2014-07-01

    Most human tumors have mutations in genes of the RAS small GTPase protein family. RAS works as a molecular switch for signaling pathways that modulate many aspects of cell behavior, including proliferation, differentiation, motility and death. Oncogenic mutations in RAS prevent GTP hydrolysis, locking RAS in a permanently active state, being the most common mutations in HRAS, KRAS and NRAS. The human RAS family consists of at least 36 different genes, many of which have been scarcely studied. One of these relatively unknown genes is ERAS (ES cell-expressed RAS), which is a constitutively active RAS protein, localized in chromosome X and expressed only in embryonic cells, being undetectable in adult tissues. New high throughput technologies have made it possible to screen complete cancer genomes for identification of mutations associated to cancer. Using the Sleeping Beauty (SB) transposon system, ERAS was identified as a putative novel oncogene in non-melanoma skin and breast cancers. The major aim of this project is to determine the general characteristics of ERAS as a putative novel human oncogene in skin and breast cells. Forced expression of ERAS results in drastic changes in cell shape, proliferation and motility. When ERAS is overexpressed in skin and breast human cells it is mainly localized in the cytoplasmic membrane. ERAS activates the phosphatidylinositol-3-OH kinase (PI3K) pathway but not the mitogen-activated protein kinase (MAPK) pathway. ERAS-expressing cells suffer spontaneous morphologic and phenotypic EMT-like changes, including cytoskeleton reorganization, vimentin and N-cadherin up-regulation and down-regulation of E-cadherin, which can be associated with increased malignancy, and invasive and metastatic potential. Our results suggest that inappropriate expression of ERAS lead to transformation of human cells. (Author)

  9. Effect of sulfur dioxide on expression of proto-oncogenes and tumor suppressor genes from rats.

    Science.gov (United States)

    Bai, Juli; Meng, Ziqiang

    2010-06-01

    Sulfur dioxide (SO(2)) is a ubiquitous air pollutant that is present in low concentrations in the urban air, and in higher concentrations in the working environment. In the present study, male Wistar rats were housed in exposure chambers and treated with 14.00 +/- 1.01, 28.00 +/- 1.77 and 56.00 +/- 3.44 mg m(-3) SO(2) for 6 h/day for 7 days, while control group was exposed to filtered air in the same condition. The mRNA and protein levels of proto-oncogenes (c-fos, c-jun, c-myc, and Ki-ras) and tumor suppressor genes (p53, Rb, and p16) were analyzed in lungs using a real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) assay and Western blot analysis. The results showed that mRNA and protein levels of c-fos, c-jun, c-myc, Ki-ras, and p53 in lungs were increased in a dose-dependent manner, while mRNA and protein levels of Rb and p16 were decreased in lungs of rats after SO(2) inhalation. These results lead to a conclusion that SO(2) exposure could activate expressions of proto-oncogenes and suppress expressions of tumor suppressor genes, which might relate to the molecular mechanism of cocarcinogenic properties and potential carcinogenic effects of SO(2). According to previous studies, the results also indicated that promoter genes of apoptosis and tumor suppressor genes could produce apoptotic signals to antagonize the growth signals that arise from oncogenes. Understanding its molecular controls will benefit development of treatments for many diseases.

  10. Identification of Novel Small Molecule Inhibitors of Oncogenic RET Kinase.

    Directory of Open Access Journals (Sweden)

    Marialuisa Moccia

    Full Text Available Oncogenic mutation of the RET receptor tyrosine kinase is observed in several human malignancies. Here, we describe three novel type II RET tyrosine kinase inhibitors (TKI, ALW-II-41-27, XMD15-44 and HG-6-63-01, that inhibit the cellular activity of oncogenic RET mutants at two digit nanomolar concentration. These three compounds shared a 3-trifluoromethyl-4-methylpiperazinephenyl pharmacophore that stabilizes the 'DFG-out' inactive conformation of RET activation loop. They blocked RET-mediated signaling and proliferation with an IC50 in the nM range in fibroblasts transformed by the RET/C634R and RET/M918T oncogenes. They also inhibited autophosphorylation of several additional oncogenic RET-derived point mutants and chimeric oncogenes. At a concentration of 10 nM, ALW-II-41-27, XMD15-44 and HG-6-63-01 inhibited RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles; they also inhibited proliferation of cancer, but not non-tumoral Nthy-ori-3-1, thyroid cells, with an IC50 in the nM range. The three compounds were capable of inhibiting the 'gatekeeper' V804M mutant which confers substantial resistance to established RET inhibitors. In conclusion, we have identified a type II TKI scaffold, shared by ALW-II-41-27, XMD15-44 and HG-6-63-01, that may be used as novel lead for the development of novel agents for the treatment of cancers harboring oncogenic activation of RET.

  11. Identification of Novel Small Molecule Inhibitors of Oncogenic RET Kinase.

    Science.gov (United States)

    Moccia, Marialuisa; Liu, Qingsong; Guida, Teresa; Federico, Giorgia; Brescia, Annalisa; Zhao, Zheng; Choi, Hwan Geun; Deng, Xianming; Tan, Li; Wang, Jinhua; Billaud, Marc; Gray, Nathanael S; Carlomagno, Francesca; Santoro, Massimo

    2015-01-01

    Oncogenic mutation of the RET receptor tyrosine kinase is observed in several human malignancies. Here, we describe three novel type II RET tyrosine kinase inhibitors (TKI), ALW-II-41-27, XMD15-44 and HG-6-63-01, that inhibit the cellular activity of oncogenic RET mutants at two digit nanomolar concentration. These three compounds shared a 3-trifluoromethyl-4-methylpiperazinephenyl pharmacophore that stabilizes the 'DFG-out' inactive conformation of RET activation loop. They blocked RET-mediated signaling and proliferation with an IC50 in the nM range in fibroblasts transformed by the RET/C634R and RET/M918T oncogenes. They also inhibited autophosphorylation of several additional oncogenic RET-derived point mutants and chimeric oncogenes. At a concentration of 10 nM, ALW-II-41-27, XMD15-44 and HG-6-63-01 inhibited RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles; they also inhibited proliferation of cancer, but not non-tumoral Nthy-ori-3-1, thyroid cells, with an IC50 in the nM range. The three compounds were capable of inhibiting the 'gatekeeper' V804M mutant which confers substantial resistance to established RET inhibitors. In conclusion, we have identified a type II TKI scaffold, shared by ALW-II-41-27, XMD15-44 and HG-6-63-01, that may be used as novel lead for the development of novel agents for the treatment of cancers harboring oncogenic activation of RET.

  12. Beyond an oncogene, Lin28 is a master regulator of cancer progression.

    Science.gov (United States)

    Wang, Xuefei; Weng, Mingjiao; Jin, Yinji; Yang, Weiwei; Wang, Xin; Wu, Di; Wang, Tianzhen; Li, Xiaobo

    2017-07-26

    The RNA binding protein Lin28 is increased in most human malignancies, and elevated Lin28 is a biomarker for poor prognosis and contributes to cancer progression. Lin28 functions as a master oncogene and is involved in almost all hallmarks of cancer. In this review, we summarize the aberrant molecular expression mechanisms and pathological roles of Lin28 in cancer progression. Moreover, we elaborate on the established molecular mechanisms, from the transcriptional level to the post-transcriptional and translational levels, by which Lin28 regulates cancer progression.

  13. Oncogenic mechanisms of Lin28 in breast cancer: new functions and therapeutic opportunities.

    Science.gov (United States)

    Xiong, Hanchu; Zhao, Wenhe; Wang, Ji; Seifer, Benjamin J; Ye, Chenyang; Chen, Yongxia; Jia, Yunlu; Chen, Cong; Shen, Jianguo; Wang, Linbo; Sui, Xinbing; Zhou, Jichun

    2017-04-11

    The RNA binding protein Lin28 is best known for the critical role in cell development, recent researches also have implied its oncogenic function in various human cancers, including breast cancer. Specifically, aberrant Lin28 participates in multiple pathological processes, such as proliferation, metastasis, radiotherapy and chemotherapy resistance, metabolism, immunity and inflammation as well as stemness. In this review, we summarize the let-7-dependent and let-7-independent mechanism regulated by Lin28, focusing on its relation with tumor hallmarks in breast cancer, and subsequently discuss our present knowledge of Lin28 to develop a molecular-based therapeutic strategy against breast cancer.

  14. Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Copp& #233; , Jean-Philippe; Patil, Christopher; Rodier, Francis; Sun, Yu; Munoz, Denise; Goldstein, Joshua; Nelson, Peter; Desprez, Pierre-Yves; Campisi, Judith

    2008-10-24

    Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP) developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA-damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial-mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL)-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment.

  15. Senescence-associated secretory phenotypes reveal cell-nonautonomous functions of oncogenic RAS and the p53 tumor suppressor.

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Coppé

    2008-12-01

    Full Text Available Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA-damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial-mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment.

  16. Stable oncogenic transformation induced by microcell-mediated gene transfer

    Institute of Scientific and Technical Information of China (English)

    吕有勇; Donald G.Blair

    1995-01-01

    Oncogenes have been identified using DNA-mediated transfection, but the size of the transferable and unrearranged DNA, gene rearrangement and amplification which occur during the transfection process limit the use of the techniques. We have evaluated microcell-mediated gene transfer techniques for the transfer and analysis of dominant oncogenes. MNNG-HOS, a transformed human cell line which contained the met oncogene mapping to human chromosome 7 was infected with retroviruses carrying drug resistance markers and used to optimize microcell preparation and transfer. Stable and drug-resistant hybrids containing single human chromosomes as well as the foci of the transformed cells containing the activated met oncogene and intact hitman chromosomes were obtained. Hybridization analysis with probes (i.e. collA2, pJ3.11) mapping up to 1 Mb away from met shows that the cells from the individual focr contain different amounts of apparently unrearranged human DNA associated with the oncogene, and the microcell-g

  17. Integrated, genome-wide screening for hypomethylated oncogenes in salivary gland adenoid cystic carcinoma

    Science.gov (United States)

    Shao, Chunbo; Sun, Wenyue; Tan, Marietta; Glazer, Chad A.; Bhan, Sheetal; Zhong, Xiaoli; Fakhry, Carole; Sharma, Rajni; Westra, William H.; Hoque, Mohammad O.; Moskaluk, Christopher A.; Sidransky, David; Califano, Joseph A.; Ha, Patrick K.

    2011-01-01

    Purpose Salivary gland adenoid cystic carcinoma (ACC) is a rare malignancy that is poorly understood. In order to look for relevant oncogene candidates under the control of promoter methylation, an integrated, genome-wide screen was performed. Experimental Design Global demethylation of normal salivary gland cell strains using 5-aza-2′-deoxycytidine (5-Aza dC) and Trichostatin A (TSA), followed by expression array analysis was performed. ACC-specific expression profiling was generated using expression microarray analysis of primary ACC and normal samples. Next, the two profiles were integrated to identify a subset of genes for further validation of promoter demethylation in ACC versus normal. Finally, promising candidates were further validated for mRNA, protein, and promoter methylation levels in larger ACC cohorts. Functional validation was then performed in cancer cell lines. Results We found 159 genes that were significantly re-expressed after 5-Aza dC/TSA treatment and overexpressed in ACC. After initial validation, eight candidates showed hypomethylation in ACC: AQP1, CECR1, C1QR1, CTAG2, P53AIP1, TDRD12, BEX1, and DYNLT3. Aquaporin 1 (AQP1) showed the most significant hypomethylation and was further validated. AQP1 hypomethylation in ACC was confirmed with two independent cohorts. Of note, there was significant overexpression of AQP1 in both mRNA and protein in the paraffin-embedded ACC cohort. Furthermore, AQP1 was up-regulated in 5-Aza dC/TSA treated SACC83. Lastly, AQP1 promoted cell proliferation and colony formation in SACC83. Conclusions Our integrated, genome-wide screening method proved to be an effective strategy for detecting novel oncogenes in ACC. AQP1 is a promising oncogene candidate for ACC and is transcriptionally regulated by promoter hypomethylation. PMID:21551254

  18. Oncogene-mediated transformation of fetal rat colon in vitro.

    Science.gov (United States)

    Pories, S; Jaros, K; Steele, G; Pauley, A; Summerhayes, I C

    1992-05-01

    Short-term maintenance of fetal rat colonic tissue in vitro has been demonstrated using a collagen matrix organ culture system. The introduction of single (v-myc, v-rasH, v-src) oncogenes or combinations of oncogenes (v-myc/rasH, v-myc/src) into normal colon mucosal elements was established using retroviral vectors, resulting in enhanced proliferation and migration of epithelial cells from the lumen of tissue implants. Expression of a single oncogene in normal colon epithelium did not result in the establishment of cell lines. In contrast, expression of cooperating oncogenic elements resulted in cell lines in greater than 80% of experiments, revealing different morphological characteristics dependent upon the oncogene combination used. Confirmation of the expression of viral transcripts was determined using Northern blot analysis and viral oncoprotein expression using Western blot analysis (p21) and an immunoprecipitation kinase assay (src). Expression of keratin filaments was lost following passaging of cell lines but could be induced by the myc/ras transformants by growth on Rat-1 feeder layers. This induction phenomenon was not observed with myc/src lines, and although these expressed high levels of sucrase isomaltase the epithelial origin of these cells is unclear. Karyotypic analysis performed on three myc/ras-transformed cell lines revealed a normal chromosome complement associated with transformation. In this report we describe a novel in vitro transformation system for normal rat colonic epithelium mediated by the introduction of oncogene elements using different retroviral vector constructs. The potential to generate cell lines representing different stages of neoplastic progression using relevant genetic components presents significant advantages for the study of cellular and molecular interactions underlying colon neoplastic progression.

  19. Noxa upregulation by oncogenic activation of MEK/ERK through CREB promotes autophagy in human melanoma cells.

    Science.gov (United States)

    Liu, Yi Lun; Lai, Fritz; Wilmott, James S; Yan, Xu Guang; Liu, Xiao Ying; Luan, Qi; Guo, Su Tang; Jiang, Chen Chen; Tseng, Hsin-Yi; Scolyer, Richard A; Jin, Lei; Zhang, Xu Dong

    2014-11-30

    Reduction in the expression of the anti-survival BH3-only proteins PUMA and Bim is associated with the pathogenesis of melanoma. However, we have found that the expression of the other BH3-only protein Noxa is commonly upregulated in melanoma cells, and that this is driven by oncogenic activation of MEK/ERK. Immunohistochemistry studies showed that Noxa was expressed at higher levels in melanomas than nevi. Moreover, the expression of Noxa was increased in metastatic compared to primary melanomas, and in thick primaries compared to thin primaries. Inhibition of oncogenic BRAFV600E or MEK downregulated Noxa, whereas activation of MEK/ERK caused its upregulation. In addition, introduction of BRAFV600E increased Noxa expression in melanocytes. Upregulation of Noxa was due to a transcriptional increase mediated by cAMP responsive element binding protein, activation of which was also increased by MEK/ERK signaling in melanoma cells. Significantly, Noxa appeared necessary for constitutive activation of autophagy, albeit at low levels, by MEK/ERK in melanoma cells. Furthermore, it was required for autophagy activation that delayed apoptosis in melanoma cells undergoing nutrient deprivation. These results reveal that oncogenic activation of MEK/ERK drives Noxa expression to promote autophagy, and suggest that Noxa has an indirect anti-apoptosis role in melanoma cells under nutrient starvation conditions.

  20. Induction of epithelial mesenchimal transition and vasculogenesis in the lenses of Dbl oncogene transgenic mice.

    Directory of Open Access Journals (Sweden)

    Paolo Fardin

    Full Text Available BACKGROUND: The Dbl family of proteins represents a large group of proto-oncogenes involved in cell growth regulation. The numerous domains that are present in many Dbl family proteins suggest that they act to integrate multiple inputs in complicated signaling networks involving the Rho GTPases. Alterations of the normal function of these proteins lead to pathological processes such as developmental disorders and neoplastic transformation. We generated transgenic mice introducing the cDNA of Dbl oncogene linked to the metallothionein promoter into the germ line of FVB mice and found that onco-Dbl expression in mouse lenses affected proliferation, migration and differentiation of lens epithelial cells. RESULTS: We used high density oligonucleotide microarray to define the transcriptional profile induced by Dbl in the lenses of 2 days, 2 weeks, and 6 weeks old transgenic mice. We observed modulation of genes encoding proteins promoting epithelial-mesenchymal transition (EMT, such as down-regulation of epithelial cell markers and up-regulation of fibroblast markers. Genes encoding proteins involved in the positive regulation of apoptosis were markedly down regulated while anti-apoptotic genes were strongly up-regulated. Finally, several genes encoding proteins involved in the process of angiogenesis were up-regulated. These observations were validated by histological and immunohistochemical examination of the transgenic lenses where vascularization can be readily observed. CONCLUSION: Onco-Dbl expression in mouse lens correlated with modulation of genes involved in the regulation of EMT, apoptosis and vasculogenesis leading to disruption of the lens architecture, epithelial cell proliferation, and aberrant angiogenesis. We conclude that onco-Dbl has a potentially important, previously unreported, capacity to dramatically alter epithelial cell migration, replication, polarization and differentiation and to induce vascularization of an epithelial

  1. Malignant transformation of mature T cells after gammaretrovirus mediated transfer of nucleophosmin-anaplastic lymphoma kinase oncogene

    Directory of Open Access Journals (Sweden)

    Ashok Kumar

    2015-01-01

    Full Text Available Background: Gene therapy has been in use to cure hereditary and acquired diseases by incorporating the desired gene into the cells with the help of gammaretroviral vectors. Despite the success of this therapy in X-linked severe combined immunodeficiency syndrome, few patients developed leukemia as a major adverse event due to retroviral insertional mutagenesis within stem cells. In experimental animals also, retroviral-mediated gene transfer technique resulted in the development of leukemia. On the other hand, evidence suggests that mature T cells (TC are relatively resistant to transformation even after retroviral-mediated transfer of potent oncogenes Tcl1, ΔTrkA and LMO2 with no reported side effects yet. Aims: To further address the safety issue for TC use in gene therapy, this study investigated susceptibility of mature polyclonal TC to malignant transformation by the retroviral-mediated transfer of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK oncogene. Materials and Methods: Wild-type mature TC, isolated from C57BL/6 donor mice (genetic background Ly5.1 were transduced with gamma-retroviral vectors encoding the potent TC oncogene NPM-ALK or the control vector enhanced green fluorescent protein eGFP. The cells were then transplanted into RAG-1 deficient recipient mice (genetic background Ly5.2. Results: Two out of five mice from NPM-ALK oncogene group developed leukemia/lymphoma after latency periods (153 and 250 days, respectively. None of the mice from the control group developed any malignancy throughout the observational period. Conclusion: Mature polyclonal TC are relatively susceptible to malignant transformation after gamma-retroviral mediated transfer of NPM-ALK oncogene; hence safety of TC use in gene therapy should be further investigated to avoid the possible side-effect of development of leukemia/lymphoma.

  2. Antineoplastic Effects of siRNA against TMPRSS2-ERG Junction Oncogene in Prostate Cancer.

    Directory of Open Access Journals (Sweden)

    Giorgia Urbinati

    Full Text Available TMPRSS2-ERG junction oncogene is present in more than 50% of patients with prostate cancer and its expression is frequently associated with poor prognosis. Our aim is to achieve gene knockdown by siRNA TMPRSS2-ERG and then to assess the biological consequences of this inhibition. First, we designed siRNAs against the two TMPRSS2-ERG fusion variants (III and IV, most frequently identified in patients' biopsies. Two of the five siRNAs tested were found to efficiently inhibit mRNA of both TMPRSS2-ERG variants and to decrease ERG protein expression. Microarray analysis further confirmed ERG inhibition by both siRNAs TMPRSS2-ERG and revealed one common down-regulated gene, ADRA2A, involved in cell proliferation and migration. The siRNA against TMPRSS2-ERG fusion variant IV showed the highest anti-proliferative effects: Significantly decreased cell viability, increased cleaved caspase-3 and inhibited a cluster of anti-apoptotic proteins. To propose a concrete therapeutic approach, siRNA TMPRSS2-ERG IV was conjugated to squalene, which can self-organize as nanoparticles in water. The nanoparticles of siRNA TMPRSS2-ERG-squalene injected intravenously in SCID mice reduced growth of VCaP xenografted tumours, inhibited oncoprotein expression and partially restored differentiation (decrease in Ki67. In conclusion, this study offers a new prospect of treatment for prostate cancer based on siRNA-squalene nanoparticles targeting TMPRSS2-ERG junction oncogene.

  3. BTB-Zinc Finger Oncogenes Are Required for Ras and Notch-Driven Tumorigenesis in Drosophila.

    Directory of Open Access Journals (Sweden)

    Karen Doggett

    Full Text Available During tumorigenesis, pathways that promote the epithelial-to-mesenchymal transition (EMT can both facilitate metastasis and endow tumor cells with cancer stem cell properties. To gain a greater understanding of how these properties are interlinked in cancers we used Drosophila epithelial tumor models, which are driven by orthologues of human oncogenes (activated alleles of Ras and Notch in cooperation with the loss of the cell polarity regulator, scribbled (scrib. Within these tumors, both invasive, mesenchymal-like cell morphology and continual tumor overgrowth, are dependent upon Jun N-terminal kinase (JNK activity. To identify JNK-dependent changes within the tumors we used a comparative microarray analysis to define a JNK gene signature common to both Ras and Notch-driven tumors. Amongst the JNK-dependent changes was a significant enrichment for BTB-Zinc Finger (ZF domain genes, including chronologically inappropriate morphogenesis (chinmo. chinmo was upregulated by JNK within the tumors, and overexpression of chinmo with either RasV12 or Nintra was sufficient to promote JNK-independent epithelial tumor formation in the eye/antennal disc, and, in cooperation with RasV12, promote tumor formation in the adult midgut epithelium. Chinmo primes cells for oncogene-mediated transformation through blocking differentiation in the eye disc, and promoting an escargot-expressing stem or enteroblast cell state in the adult midgut. BTB-ZF genes are also required for Ras and Notch-driven overgrowth of scrib mutant tissue, since, although loss of chinmo alone did not significantly impede tumor development, when loss of chinmo was combined with loss of a functionally related BTB-ZF gene, abrupt, tumor overgrowth was significantly reduced. abrupt is not a JNK-induced gene, however, Abrupt is present in JNK-positive tumor cells, consistent with a JNK-associated oncogenic role. As some mammalian BTB-ZF proteins are also highly oncogenic, our work suggests that

  4. MECP2 Is a Frequently Amplified Oncogene with a Novel Epigenetic Mechanism That Mimics the Role of Activated RAS in Malignancy

    DEFF Research Database (Denmark)

    Neupane, Manish; Clark, Allison P.; Landini, Serena;

    2016-01-01

    An unbiased genome-scale screen for unmutated genes that drive cancer growth when overexpressed identified methyl cytosine-guanine dinucleotide (CpG) binding protein 2 (MECP2) as a novel oncogene. MECP2 resides in a region of the X-chromosome that is significantly amplified across 18% of cancers,...

  5. The structural pathway of interleukin 1 (IL-1 initiated signaling reveals mechanisms of oncogenic mutations and SNPs in inflammation and cancer.

    Directory of Open Access Journals (Sweden)

    Saliha Ece Acuner Ozbabacan

    2014-02-01

    Full Text Available Interleukin-1 (IL-1 is a large cytokine family closely related to innate immunity and inflammation. IL-1 proteins are key players in signaling pathways such as apoptosis, TLR, MAPK, NLR and NF-κB. The IL-1 pathway is also associated with cancer, and chronic inflammation increases the risk of tumor development via oncogenic mutations. Here we illustrate that the structures of interfaces between proteins in this pathway bearing the mutations may reveal how. Proteins are frequently regulated via their interactions, which can turn them ON or OFF. We show that oncogenic mutations are significantly at or adjoining interface regions, and can abolish (or enhance the protein-protein interaction, making the protein constitutively active (or inactive, if it is a repressor. We combine known structures of protein-protein complexes and those that we have predicted for the IL-1 pathway, and integrate them with literature information. In the reconstructed pathway there are 104 interactions between proteins whose three dimensional structures are experimentally identified; only 15 have experimentally-determined structures of the interacting complexes. By predicting the protein-protein complexes throughout the pathway via the PRISM algorithm, the structural coverage increases from 15% to 71%. In silico mutagenesis and comparison of the predicted binding energies reveal the mechanisms of how oncogenic and single nucleotide polymorphism (SNP mutations can abrogate the interactions or increase the binding affinity of the mutant to the native partner. Computational mapping of mutations on the interface of the predicted complexes may constitute a powerful strategy to explain the mechanisms of activation/inhibition. It can also help explain how an oncogenic mutation or SNP works.

  6. Role of ets Oncogenes in the Progression of Breast Cancer

    Science.gov (United States)

    1998-10-01

    Mazabraud A. (1988). Cancer Kato J, Matsuoka M, Polyak K, Massague J and Sherr CJ. Genet. Cytogenet., 32, 229-238. (1994). Cell, 79, 487-496. Vairo G...Francisco LV , Roach JC, Argonza R, D, Weber BL and EI-Deiryh WS. (1998). Oncogene, 16, King MC and Ostrander EA. (1996). Human Mol. Genet., 1713-1721. 5

  7. Targeting MET Amplification as a New Oncogenic Driver

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hisato [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Okamoto, Isamu, E-mail: okamotoi@kokyu.med.kyushu-u.ac.jp [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Center for Clinical and Translational Research, Kyushu University Hospital, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582 (Japan); Okamoto, Wataru [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Division of Transrlational Research, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577 (Japan); Tanizaki, Junko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, HIM223, 450 Brookline Avenue, Boston, MA 02215 (United States); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Nishio, Kazuto [Department of Genome Biology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511 (Japan)

    2014-07-22

    Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.

  8. Targeting MET Amplification as a New Oncogenic Driver

    Directory of Open Access Journals (Sweden)

    Hisato Kawakami

    2014-07-01

    Full Text Available Certain genetically defined cancers are dependent on a single overactive oncogene for their proliferation and survival, a phenomenon known as “oncogene addiction”. A new generation of drugs that selectively target such “driver oncogenes” manifests a clinical efficacy greater than that of conventional chemotherapy in appropriate genetically defined patients. MET is a proto-oncogene that encodes a receptor tyrosine kinase, and aberrant activation of MET signaling occurs in a subset of advanced cancers as result of various genetic alterations including gene amplification, polysomy, and gene mutation. Our preclinical studies have shown that inhibition of MET signaling either with the small-molecule MET inhibitor crizotinib or by RNA interference targeted to MET mRNA resulted in marked antitumor effects in cancer cell lines with MET amplification both in vitro and in vivo. Furthermore, patients with non-small cell lung cancer or gastric cancer positive for MET amplification have shown a pronounced clinical response to crizotinib. Accumulating preclinical and clinical evidence thus suggests that MET amplification is an “oncogenic driver” and therefore a valid target for treatment. However, the prevalence of MET amplification has not been fully determined, possibly in part because of the difficulty in evaluating gene amplification. In this review, we provide a rationale for targeting this genetic alteration in cancer therapy.

  9. The DNA damage checkpoint precedes activation of ARF in response to escalating oncogenic stress during tumorigenesis

    DEFF Research Database (Denmark)

    Evangelou, K; Bartkova, J; Kotsinas, A

    2013-01-01

    to various oncogenes showed that the delayed upregulation of ARF reflected a requirement for a higher, transcriptionally based threshold of oncogenic stress, elicited by at least two oncogenic ‘hits’, compared with lower activation threshold for DDR. We propose that relative to DDR activation, ARF provides...

  10. Vav1 Oncogenic Mutation Inhibits T Cell Receptor-induced Calcium Mobilization through Inhibition of Phospholipase Cγ1 Activation*

    Science.gov (United States)

    Knyazhitsky, Mira; Moas, Etay; Shaginov, Ekaterina; Luria, Anna; Braiman, Alex

    2012-01-01

    Robust elevation of the cytosolic calcium concentration is a crucial early step for T cell activation triggered by the T cell antigen receptor. Vav1 is a proto-oncogene expressed in hematopoietic cells that is indispensable for transducing the calcium-mobilizing signal. Following T cell receptor stimulation, Vav1 facilitates formation of signaling microclusters through multiple interactions with other proteins participating in the signaling cascade. Truncation of the N terminus of Vav1 produces its oncogenic version, which is unable to support normal calcium flux following T cell activation. We show here that truncation of the N-terminal region of Vav1 alters the fine structure of protein complexes in the signaling clusters, affecting the interaction of Vav1 with phospholipase Cγ1 (PLCγ1). This alteration is accompanied by a decrease in PLCγ1 phosphorylation and inhibition of inositol 1,4,5-trisphosphate production. We suggest that the structural integrity of the N-terminal region of Vav1 is important for the proper formation of the Vav1-associated signaling complexes. The oncogenic truncation of this region elicits conformational changes that interfere with the Vav1-mediated activation of PLCγ1 and that inhibit calcium mobilization. PMID:22474331

  11. Malignant transformation of diploid human fibroblasts by transfection of oncogenes. Part 2, Progress report, July 1989--June 1992

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, J.J.

    1992-12-31

    This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy.

  12. v-erbA oncogene activation entails the loss of hormone-dependent regulator activity of c-erbA

    DEFF Research Database (Denmark)

    Zenke, M; Muñoz, A; Sap, J;

    1990-01-01

    and erythrocyte-specific gene expression in a T3-dependent fashion, when introduced into erythroid cells via a retrovirus. In contrast, the endogenous thyroid hormone receptor does not detectably affect erythroid differentiation. The analysis of a series of chimeric v-/c-erbA proteins suggests that the v......The v-erbA oncogene, one of the two oncogenes of the avian erythroblastosis virus, efficiently blocks erythroid differentiation and suppresses erythrocyte-specific gene transcription. Here we show that the overexpressed thyroid hormone receptor c-erbA effectively modulates erythroid differentiation......-erbA oncoprotein has lost one type of thyroid hormone receptor function (regulating erythrocyte gene transcription in response to T3), but constitutively displays another function: it represses transcription in the absence of T3. The region responsible for the loss of hormone-dependent regulator activity of v...

  13. Protein

    Science.gov (United States)

    ... Food Service Resources Additional Resources About FAQ Contact Protein Protein is found throughout the body—in muscle, ... the heart and respiratory system, and death. All Protein Isn’t Alike Protein is built from building ...

  14. KSHV ORF K9 (vIRF) is an oncogene which inhibits the interferon signaling pathway.

    Science.gov (United States)

    Gao, S J; Boshoff, C; Jayachandra, S; Weiss, R A; Chang, Y; Moore, P S

    1997-10-16

    Kaposi's sarcoma-associated herpesvirus (KSHV) is a gammaherpesvirus linked to the development of Kaposi's sarcoma and a rare B cell lymphoma, primary effusion lymphoma. The KSHV gene ORF K9 encodes vIRF which is a protein with low but significant homology to members of the interferon (IFN) regulatory factor (IRF) family responsible for regulating intracellular interferon signal transduction (Moore PS, Boshoff C, Weiss RA and Chang Y. (1996). Science, 274, 1739-1744). vIRF inhibits IFN-beta signal transduction as measured using an IFN-responsive ISG54 reporter construct co-transfected with ORF K9 into HeLa and 293 cells. vIRF also suppresses genes under IFN regulatory control as shown by inhibition of the IFN-beta inducibility of p21WAF1/CIP1, however, no direct DNA-binding or protein-protein interactions characteristic for IRF repressor proteins were identified. Stable transfectant NIH3T3 clones expressing vIRF grew in soft agar and at low serum concentrations, lost contact inhibition and formed tumors after injection into nude mice indicating that vIRF has the properties of a viral oncogene. Since vIRF is primarily expressed in KSHV-infected B cells, not KS spindle cells, this study suggests that vIRF is a transforming oncogene active in B cell neoplasias that may provide a unique immune escape mechanism for infected cells. This data is consistent with tumor suppressor pathways serving a dual function as host cell antiviral pathways.

  15. P53 suppresses expression of the 14-3-3gamma oncogene

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    Qi Wenqing

    2011-08-01

    Full Text Available Abstract Background 14-3-3 proteins are a family of highly conserved proteins that are involved in a wide range of cellular processes. Recent evidence indicates that some of these proteins have oncogenic activity and that they may promote tumorigenesis. We previously showed that one of the 14-3-3 family members, 14-3-3gamma, is over expressed in human lung cancers and that it can induce transformation of rodent cells in vitro. Methods qRTPCR and Western blot analysis were performed to examine 14-3-3gamma expression in non-small cell lung cancers (NSCLC. Gene copy number was analyzed by qPCR. P53 mutations were detected by direct sequencing and also by western blot. CHIP and yeast one hybrid assays were used to detect p53 binding to 14-3-3gamma promoter. Results Quantitative rtPCR results showed that the expression level of 14-3-3gamma was elevated in the majority of NSCLC that we examined which was also consistent with protein expression. Further analysis of the expression pattern of 14-3-3gamma in lung tumors showed a correlation with p53 mutations suggesting that p53 might suppress 14-3-3 gamma expression. Analysis of the gamma promoter sequence revealed the presence of a p53 consensus binding motif and in vitro assays demonstrated that wild-type p53 bound to this motif when activated by ionizing radiation. Deletion of the p53 binding motif eliminated p53's ability to suppress 14-3-3gamma expression. Conclusion Increased expression of 14-3-3gamma in lung cancer coincides with loss of functional p53. Hence, we propose that 14-3-3gamma's oncogenic activities cooperate with loss of p53 to promote lung tumorigenesis.

  16. Markers for sebaceoma show a spectrum of cell cycle regulators, tumor suppressor genes, and oncogenes

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    Ana Maria Abreu Velez

    2015-01-01

    Full Text Available Background: Sebaceoma is a tumor for which the causative oncogenes are not well-understood. Sebaceomas demonstrate some histopathologic features similar to basal cell carcinoma (BCC, such as palisading borders and basaloid cells with additional features, including foamy cytoplasm and indented nuclei. Aims: We examine multiple cell-cycle, oncogene, and tumor suppressor gene markers in sebaceomas, to try to find some suitable biological markers for this tumor, and compare with other published studies. Materials and Methods: We investigated a panel of immunohistochemical (IHC stains that are important for cellular signaling, including a cell cycle regulator, tumor suppressor gene, oncogene, hormone receptor, and genomic stability markers in our cohort of sebaceomas. We collected 30 sebaceomas from three separate USA dermatopathology laboratories. The following IHC panel: Epithelial membrane antigen (EMA/CD227, cytokeratin AE1/AE3, cyclin D1, human breast cancer 1 protein (BRCA-1, C-erb-2, Bcl-2, human androgen receptor (AR, cyclin-dependent kinase inhibitor 1B (p27 kip1 , p53, topoisomerase II alpha, proliferating cell nuclear antigen, and Ki-67 were tested in our cases. Results: EMA/CD227 was positive in the well-differentiated sebaceomas (13/30. Cyclin-dependent kinase inhibitor 1B was positive in tumors with intermediate differentiation (22/30. The less well-differentiated tumors failed to stain with EMA and AR. Most of the tumors with well-differentiated palisaded areas demonstrated positive staining for topoisomerase II alpha, p27 kip1 , and p53, with positive staining in tumoral basaloid areas (22/30. Numerous tumors were focally positive with multiple markers, indicating a significant degree of variability in the complete group. Conclusions: Oncogenes, tumor suppressor genes, cell cycle regulators, and hormone receptors are variably expressed in sebaceomas. Our results suggest that in these tumors, selected marker staining seems to correlate

  17. The use of Gene Ontology terms and KEGG pathways for analysis and prediction of oncogenes.

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    Xing, Zhihao; Chu, Chen; Chen, Lei; Kong, Xiangyin

    2016-11-01

    Oncogenes are a type of genes that have the potential to cause cancer. Most normal cells undergo programmed cell death, namely apoptosis, but activated oncogenes can help cells avoid apoptosis and survive. Thus, studying oncogenes is helpful for obtaining a good understanding of the formation and development of various types of cancers. In this study, we proposed a computational method, called OPM, for investigating oncogenes from the view of Gene Ontology (GO) and biological pathways. All investigated genes, including validated oncogenes retrieved from some public databases and other genes that have not been reported to be oncogenes thus far, were encoded into numeric vectors according to the enrichment theory of GO terms and KEGG pathways. Some popular feature selection methods, minimum redundancy maximum relevance and incremental feature selection, and an advanced machine learning algorithm, random forest, were adopted to analyze the numeric vectors to extract key GO terms and KEGG pathways. Along with the oncogenes, GO terms and KEGG pathways were discussed in terms of their relevance in this study. Some important GO terms and KEGG pathways were extracted using feature selection methods and were confirmed to be highly related to oncogenes. Additionally, the importance of these terms and pathways in predicting oncogenes was further demonstrated by finding new putative oncogenes based on them. This study investigated oncogenes based on GO terms and KEGG pathways. Some important GO terms and KEGG pathways were confirmed to be highly related to oncogenes. We hope that these GO terms and KEGG pathways can provide new insight for the study of oncogenes, particularly for building more effective prediction models to identify novel oncogenes. The program is available upon request. We hope that the new findings listed in this study may provide a new insight for the investigation of oncogenes. This article is part of a Special Issue entitled "System Genetics" Guest Editor

  18. Oncogene Mdm2 takes part in hepatocarcinogenesis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective:To investigate the role of Mdm2 expression in hepatocellular carcinoma.Methods: Streptavidin-peroxidase conjugation method (SP)was used to observe the expression of Mdm2 and p53 proteins in 61 cases of hepatocellular carcinoma(HCC)and 59 cases of corresponding paracancerous tissues,among which p53 mutations in exons 5~8 were detected in 21 cases by PCR-SSCP.Results:Positive nuclear P53 and Mdm2 immunostains were demonstrated in 57.38% and 26.23% of HCC,1.69% and 3.39% of corresponding paracancerous tissues respectively.The expression of p53 and Mdm2 proteins in hepatocellular carcinoma was significantly higher than that in paracancerous tissues(P<0.01).The expression of P53 and Mdm2 was not significantly correlated.42.86% of hepatocellualr carcinomas showed mutations in exon 7 of p53 gene,and no mutation was found in exons 5,6,8 and paracancerous tissues. 66.67% of mutational cases had P53 overexpression and 11.11%(1/9)showed overexpression of both P53 and Mdm2,Mdm2 overexpression also appeared in 25% of cases without mutations.Conclusions:Mdm2-induced p53 inactivation and p53 gene mutation play an important role in carcinogenesis of hepatocellular carcinoma.Tumorigenic property of Mdm2 itself,together with p53 mutation,may take part in hepatocarcinogenesis.

  19. Systematic analysis of human oncogenic viruses in colon cancer revealed EBV latency in lymphoid infiltrates.

    Science.gov (United States)

    Fiorina, Loretta; Ricotti, Mattia; Vanoli, Alessandro; Luinetti, Ombretta; Dallera, Elena; Riboni, Roberta; Paolucci, Stefania; Brugnatelli, Silvia; Paulli, Marco; Pedrazzoli, Paolo; Baldanti, Fausto; Perfetti, Vittorio

    2014-01-01

    Environmental factors may play a role in colon cancer. In this view, several studies investigated tumor samples for the presence of various viral DNA with conflicting results. We undertook a systematic DNA analysis of 44 consecutive, prospectively collected primary tumor samples by real time and qualitative PCR for viruses of known or potential oncogenic role in humans, including polyomavirus (JCV, BKV, Merkel cell polyomavirus), HPV, HTLV, HHV-8 and EBV. Negative controls consisted of surgical resection margins. No evidence of genomic DNA fragments from tested virus were detected, except for EBV, which was found in a significant portion of tumors (23/44, 52%). Real-time PCR showed that EBV DNA was present at a highly variable content (median 258 copies in 10(5) cells, range 15-4837). Presence of EBV DNA had a trend to be associated with high lymphocyte infiltration (p = 0.06, χ2 test), and in situ hybridization with EBER1-2 probes revealed latency in a fraction of these lymphoid cells, with just a few scattered plasma cells positive for BZLF-1, an immediate early protein expressed during lytic replication. LMP-1 expression was undetectable by immunohistochemistry. These results argue against a significant involvement of the tested oncogenic viruses in established colon cancer.

  20. Anti-Differentiation Effect of Oncogenic Met Receptor in Terminally-Differentiated Myotubes

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    Valentina Sala

    2015-02-01

    Full Text Available Activation of the hepatocyte growth factor/Met receptor is involved in muscle regeneration, through promotion of proliferation and inhibition of differentiation in myogenic stem cells (MSCs. We previously described that the specific expression of an oncogenic version of the Met receptor (Tpr–Met in terminally-differentiated skeletal muscle causes muscle wasting in vivo. Here, we induced Tpr–Met in differentiated myotube cultures derived from the transgenic mouse. These cultures showed a reduced protein level of myosin heavy chain (MyHC, increased phosphorylation of Erk1,2 MAPK, the formation of giant sacs of myonuclei and the collapse of elongated myotubes. Treatment of the cultures with an inhibitor of the MAPK kinase pathway or with an inhibitor of the proteasome increased the expression levels of MyHC. In addition, the inhibition of the MAPK kinase pathway prevented the formation of myosacs and myotube collapse. Finally, we showed that induction of Tpr–Met in primary myotubes was unable to produce endoreplication in their nuclei. In conclusion, our data indicate that multinucleated, fused myotubes may be forced to disassemble their contractile apparatus by the Tpr–Met oncogenic factor, but they resist the stimulus toward the reactivation of the cell cycle.

  1. Oncogene Mimicry as a Mechanism of Primary Resistance to BRAF Inhibitors

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    Martin L. Sos

    2014-08-01

    Full Text Available Despite the development of potent RAF/mitogen-activated protein kinase (MAPK pathway inhibitors, only a fraction of BRAF-mutant patients benefit from treatment with these drugs. Using a combined chemogenomics and chemoproteomics approach, we identify drug-induced RAS-RAF-MEK complex formation in a subset of BRAF-mutant cancer cells characterized by primary resistance to vemurafenib. In these cells, autocrine interleukin-6 (IL-6 secretion may contribute to the primary resistance phenotype via induction of JAK/STAT3 and MAPK signaling. In a subset of cell lines, combined IL-6/MAPK inhibition is able to overcome primary resistance to BRAF-targeted therapy. Overall, we show that the signaling plasticity exerted by primary resistant BRAF-mutant cells is achieved by their ability to mimic signaling features of oncogenic RAS, a strategy that we term “oncogene mimicry.” This model may guide future strategies for overcoming primary resistance observed in these tumors.

  2. CLK2 Is an Oncogenic Kinase and Splicing Regulator in Breast Cancer.

    Science.gov (United States)

    Yoshida, Taku; Kim, Jee Hyun; Carver, Kristopher; Su, Ying; Weremowicz, Stanislawa; Mulvey, Laura; Yamamoto, Shoji; Brennan, Cameron; Mei, Shenglin; Long, Henry; Yao, Jun; Polyak, Kornelia

    2015-04-01

    Genetically activated kinases have been attractive therapeutic targets in cancer due to the relative ease of developing tumor-specific treatment strategies for them. To discover novel putative oncogenic kinases, we identified 26 genes commonly amplified and overexpressed in breast cancer and subjected them to a lentiviral shRNA cell viability screen in a panel of breast cancer cell lines. Here, we report that CLK2, a kinase that phosphorylates SR proteins involved in splicing, acts as an oncogene in breast cancer. Deregulated alternative splicing patterns are commonly observed in human cancers but the underlying mechanisms and functional relevance are still largely unknown. CLK2 is amplified and overexpressed in a significant fraction of breast tumors. Downregulation of CLK2 inhibits breast cancer growth in cell culture and in xenograft models and it enhances cell migration and invasion. Loss of CLK2 in luminal breast cancer cells leads to the upregulation of epithelial-to-mesenchymal transition (EMT)-related genes and a switch to mesenchymal splice variants of several genes, including ENAH (MENA). These results imply that therapeutic targeting of CLK2 may be used to modulate EMT splicing patterns and to inhibit breast tumor growth.

  3. Genomic profiling identifies GATA6 as a candidate oncogene amplified in pancreatobiliary cancer.

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    Kevin A Kwei

    2008-05-01

    Full Text Available Pancreatobiliary cancers have among the highest mortality rates of any cancer type. Discovering the full spectrum of molecular genetic alterations may suggest new avenues for therapy. To catalogue genomic alterations, we carried out array-based genomic profiling of 31 exocrine pancreatic cancers and 6 distal bile duct cancers, expanded as xenografts to enrich the tumor cell fraction. We identified numerous focal DNA amplifications and deletions, including in 19% of pancreatobiliary cases gain at cytoband 18q11.2, a locus uncommonly amplified in other tumor types. The smallest shared amplification at 18q11.2 included GATA6, a transcriptional regulator previously linked to normal pancreas development. When amplified, GATA6 was overexpressed at both the mRNA and protein levels, and strong immunostaining was observed in 25 of 54 (46% primary pancreatic cancers compared to 0 of 33 normal pancreas specimens surveyed. GATA6 expression in xenografts was associated with specific microarray gene-expression patterns, enriched for GATA binding sites and mitochondrial oxidative phosphorylation activity. siRNA mediated knockdown of GATA6 in pancreatic cancer cell lines with amplification led to reduced cell proliferation, cell cycle progression, and colony formation. Our findings indicate that GATA6 amplification and overexpression contribute to the oncogenic phenotypes of pancreatic cancer cells, and identify GATA6 as a candidate lineage-specific oncogene in pancreatobiliary cancer, with implications for novel treatment strategies.

  4. Alternative translation of the proto-oncogene c-myc by an internal ribosome entry site.

    Science.gov (United States)

    Nanbru, C; Lafon, I; Audigier, S; Gensac, M C; Vagner, S; Huez, G; Prats, A C

    1997-12-19

    The human proto-oncogene c-myc encodes two proteins, c-Myc1 and c-Myc2, from two initiation codons, CUG and AUG, respectively. It is also transcribed from four alternative promoters (P0, P1, P2, and P3), giving rise to different RNA 5'-leader sequences, the long sizes of which suggest that they must be inefficiently translated by the classical ribosome scanning mechanism. Here we have examined the influence of three c-myc mRNA 5'-leaders on the translation of chimeric myc-CAT mRNAs. We observed that in the reticulocyte rabbit lysate, these 5'-leaders lead to cap-independent translation initiation. To determine whether this kind of initiation resulted from the presence of an internal ribosome entry site (IRES), COS-7 cells were transfected with bicistronic vectors containing the different c-myc 5'-leaders in the intercistronic region. An IRES was identified, requiring elements located within the P2 leader, between nucleotides -363 and -94 upstream from the CUG start codon. This is the first demonstration of the existence of IRES-dependent translation for a proto-oncogene. This IRES could be a translation enhancer, allowing activation of c-myc expression under the control of trans-acting factors and in response to specific cell stimuli.

  5. Lentivirus-Mediated Oncogene Introduction into Mammary Cells In Vivo Induces Tumors

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    Stefan K. Siwko

    2008-07-01

    Full Text Available We recently reported the introduction of oncogene-expressing avian retroviruses into somatic mammary cells in mice susceptible to infection by transgenic expression of tva, encoding the receptor for subgroup A avian leukosis-sarcoma virus (ALSV. Because ALSV-based vectors poorly infect nondividing cells, they are inadequate for studying carcinogenesis initiated from nonproliferative cells (e.g., stem cells. Lentivirus pseudotyped with the envelope protein of ALSV infects nondividing TVA-producing cells in culture but has not previously been tested for introducing genes in vivo. Here, we demonstrate that these vectors infected mammary cells in vivo when injected into the mammary ductal lumen of mice expressing tva under the control of the keratin 19 promoter. Furthermore, intraductal injection of this lentiviral vector carrying the polyoma middle T antigen gene induced atypical ductal hyperplasia and ductal carcinoma in situ-like premalignant lesions in 30 days and palpable invasive tumors at a median latency of 3.3 months. Induced tumors were a mixed epithelial/myoepithelial histologic diagnosis, occasionally displayed squamous metaplasia, and were estrogen receptor-negative. This work demonstrates the first use of a lentiviral vector to introduce oncogenes for modeling cancer in mice, and this vector system may be especially suitable for introducing genetic alterations into quiescent cells in vivo.

  6. Drosophila PRL-1 is a growth inhibitor that counteracts the function of the Src oncogene.

    Science.gov (United States)

    Pagarigan, Krystle T; Bunn, Bryce W; Goodchild, Jake; Rahe, Travis K; Weis, Julie F; Saucedo, Leslie J

    2013-01-01

    Phosphatase of Regenerating Liver (PRL) family members have emerged as molecular markers that significantly correlate to the ability of many cancers to metastasize. However, contradictory cellular responses to PRL expression have been reported, including the inhibition of cell cycle progression. An obvious culprit for the discrepancy is the use of dozens of different cell lines, including many isolated from tumors or cultured cells selected for immortalization which may have missing or mutated modulators of PRL function. We created transgenic Drosophila to study the effects of PRL overexpression in a genetically controlled, organismal model. Our data support the paradigm that the normal cellular response to high levels of PRL is growth suppression and furthermore, that PRL can counter oncogenic activity of Src. The ability of PRL to inhibit growth under normal conditions is dependent on a CAAX motif that is required to localize PRL to the apical edge of the lateral membrane. However, PRL lacking the CAAX motif can still associate indiscriminately with the plasma membrane and retains its ability to inhibit Src function. We propose that PRL binds to other membrane-localized proteins that are effectors of Src or to Src itself. This first examination of PRL in a model organism demonstrates that PRL performs as a tumor suppressor and underscores the necessity of identifying the conditions that enable it to transform into an oncogene in cancer.

  7. Methylation profile and amplification of proto-oncogenes in rat pancreas induced with phytoestrogens

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    Lyn-Cook, B.D.; Blann, E.; Bo, J. [National Center for Toxicological Research, Jefferson, AR (United States)

    1995-01-01

    Specific gene hypermethylation has been shown in DNA from neonatal rats exposed to the phytoestrogens, coumestrol, and equol. The pancreas is an organ in which estrogen receptors have been shown to be present. Studies have correlated the development of acute pancreatitis with rising levels of human estrogen binding proteins. Neonatal rats were dosed with 10 or 100 {mu}g of coumestrol or equol on postnatal day (PND) 1-10. The animals were sacrificed at Day 15. The pancreas was excised and pancreatic acinar cells isolated for molecular analysis. DNA was isolated from the cells by lysis in TEN-9 buffer supplemented with proteinase K and 0.1% SDS. High molecular weight (HMW) DNA was digested with the methylated DNA specific restriction enzymes, Hpa II and Msp I, for determination of methylation profiles. Both coumestrol and equol at high doses caused hypermethylation of the c-H-ras proto-oncogene. No hypermethylation or hypomethylation was observed in the proto-oncogenes, c-myc or c-fos. Methylation is thought to be an epigenetic mechanism involved in the activation (hypomethylation) or inactivation (hypermethylation) of cellular genes which are known to play a role in carcinogenesis. Epidemiology studies have shown that equol may have anti-carcinogenic effects on some hormone-dependent cancers. Additional studies are needed to further understand the role of phytoestrogens and methylation in relation to pancreatic disorders. 15 refs., 4 figs.

  8. Large-scale analysis by SAGE reveals new mechanisms of v-erbA oncogene action

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    Faure Claudine

    2007-10-01

    Full Text Available Abstract Background: The v-erbA oncogene, carried by the Avian Erythroblastosis Virus, derives from the c-erbAα proto-oncogene that encodes the nuclear receptor for triiodothyronine (T3R. v-ErbA transforms erythroid progenitors in vitro by blocking their differentiation, supposedly by interference with T3R and RAR (Retinoic Acid Receptor. However, v-ErbA target genes involved in its transforming activity still remain to be identified. Results: By using Serial Analysis of Gene Expression (SAGE, we identified 110 genes deregulated by v-ErbA and potentially implicated in the transformation process. Bioinformatic analysis of promoter sequence and transcriptional assays point out a potential role of c-Myb in the v-ErbA effect. Furthermore, grouping of newly identified target genes by function revealed both expected (chromatin/transcription and unexpected (protein metabolism functions potentially deregulated by v-ErbA. We then focused our study on 15 of the new v-ErbA target genes and demonstrated by real time PCR that in majority their expression was activated neither by T3, nor RA, nor during differentiation. This was unexpected based upon the previously known role of v-ErbA. Conclusion: This paper suggests the involvement of a wealth of new unanticipated mechanisms of v-ErbA action.

  9. The non-coding oncogene: a case of missing DNA evidence?

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    Puja eShahrouki

    2012-09-01

    Full Text Available The evidence that links classical protein-coding proto-oncogenes and tumor suppressors, such as MYC, RAS, P53, and RB, to carcinogenesis is indisputable. Multiple lines of proof show how random somatic genomic alteration of such genes (e.g. mutation, deletion or amplification, followed by selection and clonal expansion, forms the main molecular basis of tumor development. Many important cancer genes were discovered using low-throughput approaches in the pre-genomic era, and this knowledge is today solidified and expanded upon by modern genome-scale methodologies. In several recent studies, non-coding RNAs (ncRNAs, such as microRNAs and long non-coding RNAs (lncRNAs, have been shown to contribute to tumor development. However, in comparison with coding cancer genes, the genomic (DNA-level evidence is sparse for ncRNAs. The coding proto-oncogenes and tumor suppressors that we know of today are major molecular hubs in both normal and malignant cells. The search for non-coding RNAs with tumor driver or suppressor roles therefore holds the additional promise of pinpointing important, biologically active, ncRNAs in a vast and largely uncharacterized non-coding transcriptome. Here, we assess the available DNA-level data that links non-coding genes to tumor development. We further consider historical, methodological and biological aspects, and discuss future prospects of ncRNAs in cancer.

  10. Chrysotile effects on the expression of anti-oncogene P53 and P16 and oncogene C-jun and C-fos in Wistar rats' lung tissues.

    Science.gov (United States)

    Cui, Yan; Wang, Yuchan; Deng, Jianjun; Hu, Gongli; Dong, Faqin; Zhang, Qingbi

    2017-09-13

    Chrysotile is the most widely used form of asbestos worldwide. China is the world's largest consumer and second largest producer of chrysotile. The carcinogenicity of chrysotile has been extensively documented, and accumulative evidence has shown that chrysotile is capable of causing lung cancer and other forms of cancer. However, molecular mechanisms underlying the tumorigenic effects of chrysotile remained poorly understood. To explore the carcinogenicity of chrysotile, Wistar rats were administered by intratracheal instillation (by an artificial route of administration) for 0, 0.5, 2, or 8 mg/ml of natural chrysotile (from Mangnai, Qinghai, China) dissolved in saline, repeated once a month for 6 months (a repeated high-dose exposure which may have little bearing on the effects following human exposure). The lung tissues were analyzed for viscera coefficients and histopathological alterations. Expression of P53, P16, C-JUN, and C-FOS was measured by western blotting and qRT-PCR. Our results found that chrysotile exposure leads the body weight to grow slowly and lung viscera coefficients to increase in a dose-dependent manner. General sample showed white nodules, punctiform asbestos spots, and irregular atrophy; moreover, HE staining revealed inflammatory infiltration, damage of alveolar structures, agglomerations, and pulmonary fibrosis. In addition, chrysotile can induce inactivation of the anti-oncogene P53 and P16 and activation of the proto-oncogenes C-JUN and C-FOS both in the messenger RNA and protein level. In conclusion, chrysotile induced an imbalanced expression of cancer-related genes in rats' lung tissue. These results contribute to our understanding of the carcinogenic mechanism of chrysotile.

  11. Arsenic trioxide inhibits cell proliferation and human papillomavirus oncogene expression in cervical cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hongtao [Department of Pathology, School of Medicine, Southeast University, Nanjing 210009 (China); Gao, Peng [Department of Internal Medicine, University of Iowa, Iowa City, IA 52242 (United States); Zheng, Jie, E-mail: jiezheng54@126.com [Department of Pathology, School of Medicine, Southeast University, Nanjing 210009 (China)

    2014-09-05

    Highlights: • As{sub 2}O{sub 3} inhibits growth of cervical cancer cells and expression of HPV oncogenes in these cells. • HPV-negative cervical cancer cells are more sensitive to As{sub 2}O{sub 3} than HPV-positive cervical cancer cells. • HPV-18 positive cervical cancer cells are more sensitive to As{sub 2}O{sub 3} than HPV-16 positive cancer cells. • Down-regulation of HPV oncogenes by As{sub 2}O{sub 3} is partially due to the diminished AP-1 binding. - Abstract: Arsenic trioxide (As{sub 2}O{sub 3}) has shown therapeutic effects in some leukemias and solid cancers. However, the molecular mechanisms of its anticancer efficacy have not been clearly elucidated, particularly in solid cancers. Our previous data showed that As{sub 2}O{sub 3} induced apoptosis of human papillomavirus (HPV) 16 DNA-immortalized human cervical epithelial cells and cervical cancer cells and inhibited the expression of HPV oncogenes in these cells. In the present study, we systemically examined the effects of As{sub 2}O{sub 3} on five human cervical cancer cell lines and explored the possible molecular mechanisms. MTT assay showed that HPV-negative C33A cells were more sensitive to growth inhibition induced by As{sub 2}O{sub 3} than HPV-positive cervical cancer cells, and HPV 18-positive HeLa and C4-I cells were more sensitive to As{sub 2}O{sub 3} than HPV 16-positive CaSki and SiHa cells. After As{sub 2}O{sub 3} treatment, both mRNA and protein levels of HPV E6 and E7 obviously decreased in all HPV positive cell lines. In contrast, p53 and Rb protein levels increased in all tested cell lines. Transcription factor AP-1 protein expression decreased significantly in HeLa, CaSki and C33A cells with ELISA method. These results suggest that As{sub 2}O{sub 3} is a potential anticancer drug for cervical cancer.

  12. The ETS family of oncogenic transcription factors in solid tumours.

    Science.gov (United States)

    Sizemore, Gina M; Pitarresi, Jason R; Balakrishnan, Subhasree; Ostrowski, Michael C

    2017-06-01

    Findings over the past decade have identified aberrant activation of the ETS transcription factor family throughout all stages of tumorigenesis. Specifically in solid tumours, gene rearrangement and amplification, feed-forward growth factor signalling loops, formation of gain-of-function co-regulatory complexes and novel cis-acting mutations in ETS target gene promoters can result in increased ETS activity. In turn, pro-oncogenic ETS signalling enhances tumorigenesis through a broad mechanistic toolbox that includes lineage specification and self-renewal, DNA damage and genome instability, epigenetics and metabolism. This Review discusses these different mechanisms of ETS activation and subsequent oncogenic implications, as well as the clinical utility of ETS factors.

  13. Regulation of apoptosis by the papillomavirus E6 oncogene

    Institute of Scientific and Technical Information of China (English)

    Ting-Ting Li; Li-Na Zhao; Zhi-Guo Liu; Ying Han; Dai-Ming Fan

    2005-01-01

    Infection with human papillomaviruses is strongly associated with the development of multiple cancers including esophageal squamous cell carcinoma. The HPV E6 gene is essential for the oncogenic potential of HPV.The recgulation of apoptosis by oncogene has been relatel to carcinogenesis closely; therefore, the modulation of E6 on cellular apoptosis has become a hot research topic recently. Inactivation of the pro-apoptotic tumor suppressor p53 by E6 is an important mechanism by which E6promotes cell growth; it is expected that inactivation of p53 by E6 should lead to a reduction in cellular apoptosis,numerous studies showed that E6 could in fact sensitize cells to apoptosis. The molecular basis for apoptosis modulation by E6 is poorly understood. In this article, we will present an overview of observations and current understanding of molecular basis for E6-induced apoptosis.

  14. Oncogenic osteomalacia presenting as bilateral stress fractures of the tibia

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Kenjirou; Ohnishi, Takeshi; Ishikawa, Tohru [Department of Radiology, St. Marianna University Hospital, Kanagawa (Japan); Tani, Haruo [Department of Internal Medicine III, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan); Uesugi, Keisuke [Department of Otolaryngology, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan); Takagi, Masayuki [Department of Pathology, St. Marianna University Hospital, Kawasaki City, Kanagawa (Japan)

    1999-01-01

    We report on a patient with bilateral stress fractures of the tibia who subsequently showed classic biochemical features of oncogenic osteomalacia. Conventional radiographs were normal. MR imaging revealed symmetric, bilateral, band-like low-signal lesions perpendicular to the medial cortex of the tibiae and corresponding to the only lesions subsequently seen on the bone scan. A maxillary sinus lesion was subsequently detected and surgically removed resulting in prompt alleviation of symptoms and normalization of hypophosphatemia and low 1,25-(OH){sub 2} vitamin D{sub 3}. The lesion was pathologically diagnosed as a hemangiopericytoma-like tumor. Patients with oncogenic osteomalacia may present with stress fractures limited to the tibia, as seen in athletes. The clue to the real diagnosis lies in paying close attention to the serum phosphate levels, especially in patients suffering generalized symptoms of weakness and not given to unusual physical activity. (orig.) With 4 figs., 6 refs.

  15. Advances on Driver Oncogenes of Squamous Cell Lung Cancer

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    Wei HONG

    2014-05-01

    Full Text Available Background and objective Lung cancer is the leading cause of cancer-related deaths worldwide. Next to adenocarcinoma, squamous cell carcinoma (SCC of the lung is the most frequent histologic subtype in non-small cell lung cancer. Several molecular alterations have been defined as "driver oncogenes" responsible for both the initiation and maintenance of the malignancy. The squamous cell carcinoma of the lung has recently shown peculiar molecular characteristics which relate with both carcinogenesis and response to targeted drugs. So far, about 40% of lung squamous cell carcinoma has been found harbouring driver oncogenes, in which fibroblast growth factor receptor 1 (FGFR1 plays important roles. In this review, we will report the mainly advances on some latest driver mutations of squamous cell lung cancer.

  16. Annotating MYC oncogene status with 89Zr-transferrin imaging

    OpenAIRE

    Holland, Jason P.; Evans, Michael J.; Rice, Samuel L.; Wongvipat, John; Sawyers, Charles L.; Lewis, Jason S.

    2012-01-01

    A non-invasive technology that quantitatively measures the activity of oncogenic signaling pathways could broadly impact cancer diagnosis and treatment using targeted therapies. Here we describe the development of 89Zr-desferrioxamine transferrin (89Zr-Tf), a novel positron emission tomography (PET) radiotracer that binds the transferrin receptor 1 (TFRC, CD71) with high avidity. 89Zr-Tf produces high contrast PET images that quantitatively reflect treatment-induced changes in MYC-regulated T...

  17. Mutations in the RET proto-oncogene in sporadic pheochromocytomas

    Energy Technology Data Exchange (ETDEWEB)

    Thibodeau, S.N.; Lindor, N.M.; Honchel, R. [Mayo Clinic and Foundation, Rochester, MN (United States)] [and others

    1994-09-01

    Mutations in the RET proto-oncogene have recently been demonstrated in kindreds with Multiple Endocrine Neoplasia (MEN) types 2A and 2B. Both of these autosomal dominant disorders are characterized by the development of neoplasia in cell lines of neural crest origin, such as medullary throid carcinomas and pheochromocytomas. Individuals with MEN 2B have, in addition, ganglioneuromas of the lips, tongue and colon, a marfanoid habitus, and corneal nerve thickening. Approximately 90% of patients with MEN 2A have a germline mutation in exons 10 or 11, while 95% of patients with MEN 2B have a T{yields}C transition in codon 918 of exon 16. In this study, pheochromocytomas from 29 individuals who had no clinical evidence of MEN 2A or 2B (sporadic) were examined for the presence of either germline or somatic mutations in exons 10, 11, and 16 of the RET proto-oncogene. Of the 29 tumors examined, 3 (10%) were found to have a mutation in one of the three exons. One tumor had a G{yields}A transition in codon 609 (exon 10), another had a 6 bp deletion encompassing codons 632 & 633 (exon 11), and the final tumor had a T{yields}C transition in codon 918 (exon 16). These mutations were not found in the corresponding normal DNA from these individuals, indicating that the mutation were somatic in origin. Although we cannot exclude the possibility of mutations in other regions of the RET proto-oncogene, our data suggests that: (1) individuals presenting with apparently sporadic pheochromocytomas are not likely to have undiagnosed MEN 2A or 2B; and (2) somatic mutations in the RET proto-oncogene contribute to the process of tumorigenesis in a small percentage of sporadic pheochromocytomas.

  18. PKC Epsilon: A Novel Oncogenic Player in Prostate Cancer

    Science.gov (United States)

    2014-09-01

    Malik, A., Zaman, N., Sarfaraz, S., Siddiqui, I. A., Syed, D. N. et al (2007). Combined inhibitory effects of green tea polyphenols and selective...not only in prostate cancer but also in several other epithelial cancers including lung , breast, and thyroid cancer8, 13, 20-26. Studies from our...Cvarepsilon is required for non-small cell lung carcinoma growth and regulates the expression of apoptotic genes. Oncogene 31: 2593-2600. 23 Hafeez, B. B

  19. Activation of oncogenes by radon progeny and x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Ling, C.C.

    1990-01-01

    The overall goal of this proposal is to study the carcinogenic effect of both high and low LET radiation at the molecular level, utilizing techniques developed in molecular biology, cancer cell biology and radiation biology. The underlying assumption is that malignant transformation of normal cells is a multistep process requiring two or more molecular events in the genomic DNA. We hypothesize that radiation may induce such events in one or more steps of the multistep process. We will use in vitro models of transformation that reproduce the stepwise progression of normal cells toward the transformed phenotype and ask whether radiation can provide the necessary activating function at discrete steps along this path. Our strategy involves transfecting into normal primary cells a variety of cloned oncogenes that are known to supply only some of the functions necessary for full transformation. These partially transformed'' cells will be the targets for irradiation by x-rays and alpha particles. The results will provide the basis for assessing the ability of ionizing radiation to activate oncogenic functions that complement'' the oncogene already present in the transfected cells and produce the fully transformed phenotype. Progress is described. 121 refs.

  20. Phosphoglycerate Dehydrogenase: Potential Therapeutic Target and Putative Metabolic Oncogene

    Directory of Open Access Journals (Sweden)

    Cheryl K. Zogg

    2014-01-01

    Full Text Available Exemplified by cancer cells’ preference for glycolysis, for example, the Warburg effect, altered metabolism in tumorigenesis has emerged as an important aspect of cancer in the past 10–20 years. Whether due to changes in regulatory tumor suppressors/oncogenes or by acting as metabolic oncogenes themselves, enzymes involved in the complex network of metabolic pathways are being studied to understand their role and assess their utility as therapeutic targets. Conversion of glycolytic intermediate 3-phosphoglycerate into phosphohydroxypyruvate by the enzyme phosphoglycerate dehydrogenase (PHGDH—a rate-limiting step in the conversion of 3-phosphoglycerate to serine—represents one such mechanism. Forgotten since classic animal studies in the 1980s, the role of PHGDH as a potential therapeutic target and putative metabolic oncogene has recently reemerged following publication of two prominent papers near-simultaneously in 2011. Since that time, numerous studies and a host of metabolic explanations have been put forward in an attempt to understand the results observed. In this paper, I review the historic progression of our understanding of the role of PHGDH in cancer from the early work by Snell through its reemergence and rise to prominence, culminating in an assessment of subsequent work and what it means for the future of PHGDH.

  1. Oncogenic Kras initiates leukemia in hematopoietic stem cells.

    Directory of Open Access Journals (Sweden)

    Amit J Sabnis

    2009-03-01

    Full Text Available How oncogenes modulate the self-renewal properties of cancer-initiating cells is incompletely understood. Activating KRAS and NRAS mutations are among the most common oncogenic lesions detected in human cancer, and occur in myeloproliferative disorders (MPDs and leukemias. We investigated the effects of expressing oncogenic Kras(G12D from its endogenous locus on the proliferation and tumor-initiating properties of murine hematopoietic stem and progenitor cells. MPD could be initiated by Kras(G12D expression in a highly restricted population enriched for hematopoietic stem cells (HSCs, but not in common myeloid progenitors. Kras(G12D HSCs demonstrated a marked in vivo competitive advantage over wild-type cells. Kras(G12D expression also increased the fraction of proliferating HSCs and reduced the overall size of this compartment. Transplanted Kras(G12D HSCs efficiently initiated acute T-lineage leukemia/lymphoma, which was associated with secondary Notch1 mutations in thymocytes. We conclude that MPD-initiating activity is restricted to the HSC compartment in Kras(G12D mice, and that distinct self-renewing populations with cooperating mutations emerge during cancer progression.

  2. Oncogenic transformation of diverse gastrointestinal tissues in primary organoid culture.

    Science.gov (United States)

    Li, Xingnan; Nadauld, Lincoln; Ootani, Akifumi; Corney, David C; Pai, Reetesh K; Gevaert, Olivier; Cantrell, Michael A; Rack, Paul G; Neal, James T; Chan, Carol W-M; Yeung, Trevor; Gong, Xue; Yuan, Jenny; Wilhelmy, Julie; Robine, Sylvie; Attardi, Laura D; Plevritis, Sylvia K; Hung, Kenneth E; Chen, Chang-Zheng; Ji, Hanlee P; Kuo, Calvin J

    2014-07-01

    The application of primary organoid cultures containing epithelial and mesenchymal elements to cancer modeling holds promise for combining the accurate multilineage differentiation and physiology of in vivo systems with the facile in vitro manipulation of transformed cell lines. Here we used a single air-liquid interface culture method without modification to engineer oncogenic mutations into primary epithelial and mesenchymal organoids from mouse colon, stomach and pancreas. Pancreatic and gastric organoids exhibited dysplasia as a result of expression of Kras carrying the G12D mutation (Kras(G12D)), p53 loss or both and readily generated adenocarcinoma after in vivo transplantation. In contrast, primary colon organoids required combinatorial Apc, p53, Kras(G12D) and Smad4 mutations for progressive transformation to invasive adenocarcinoma-like histology in vitro and tumorigenicity in vivo, recapitulating multi-hit models of colorectal cancer (CRC), as compared to the more promiscuous transformation of small intestinal organoids. Colon organoid culture functionally validated the microRNA miR-483 as a dominant driver oncogene at the IGF2 (insulin-like growth factor-2) 11p15.5 CRC amplicon, inducing dysplasia in vitro and tumorigenicity in vivo. These studies demonstrate the general utility of a highly tractable primary organoid system for cancer modeling and driver oncogene validation in diverse gastrointestinal tissues.

  3. PRG3 induces Ras-dependent oncogenic cooperation in gliomas

    Science.gov (United States)

    Yakubov, Eduard; Chen, Daishi; Broggini, Thomas; Sehm, Tina; Majernik, Gökce Hatipoglu; Hock, Stefan W.; Schwarz, Marc; Engelhorn, Tobias; Doerfler, Arnd; Buchfelder, Michael; Eyupoglu, Ilker Y.; Savaskan, Nicolai E.

    2016-01-01

    Malignant gliomas are one of the most devastating cancers in humans. One characteristic hallmark of malignant gliomas is their cellular heterogeneity with frequent genetic lesions and disturbed gene expression levels conferring selective growth advantage. Here, we report on the neuronal-associated growth promoting gene PRG3 executing oncogenic cooperation in gliomas. We have identified perturbed PRG3 levels in human malignant brain tumors displaying either elevated or down-regulated PRG3 levels compared to non-transformed specimens. Further, imbalanced PRG3 levels in gliomas foster Ras-driven oncogenic amplification with increased proliferation and cell migration although angiogenesis was unaffected. Hence, PRG3 interacts with RasGEF1 (RasGRF1/CDC25), undergoes Ras-induced challenges, whereas deletion of the C-terminal domain of PRG3 (PRG3ΔCT) inhibits Ras. Moreover PRG3 silencing makes gliomas resistant to Ras inhibition. In vivo disequilibrated PRG3 gliomas show aggravated proliferation, invasion, and deteriorate clinical outcome. Thus, our data show that the interference with PRG3 homeostasis amplifies oncogenic properties and foster the malignancy potential in gliomas. PMID:27058420

  4. CRAF R391W is a melanoma driver oncogene

    Science.gov (United States)

    Atefi, Mohammad; Titz, Bjoern; Tsoi, Jennifer; Avramis, Earl; Le, Allison; Ng, Charles; Lomova, Anastasia; Lassen, Amanda; Friedman, Michael; Chmielowski, Bartosz; Ribas, Antoni; Graeber, Thomas G.

    2016-01-01

    Approximately 75% of melanomas have known driver oncogenic mutations in BRAF, NRAS, GNA11 or GNAQ, while the mutations providing constitutive oncogenic signaling in the remaining melanomas are not known. We established a melanoma cell line from a tumor with none of the common driver mutations. This cell line demonstrated a signaling profile similar to BRAF-mutants, but lacked sensitivity to the BRAF inhibitor vemurafenib. RNA-seq mutation data implicated CRAF R391W as the alternative driver mutation of this melanoma. CRAF R391W was homozygous and over expressed. These melanoma cells were highly sensitive to CRAF, but not BRAF knockdown. In reconstitution experiments, CRAF R391W, but not CRAF WT, transformed NIH3T3 cells in soft-agar colony formation assays, increased kinase activity in vitro, induced MAP kinase signaling and conferred vemurafenib resistance. MAP kinase inducing activity was dependent on CRAF dimerization. Thus, CRAF is a bona fide alternative oncogene for BRAF/NRAS/GNAQ/GNA11 wild type melanomas. PMID:27273450

  5. Peroxisome proliferator-activated receptor γ (PPARγ) mediates a Ski oncogene-induced shift from glycolysis to oxidative energy metabolism.

    Science.gov (United States)

    Ye, Fang; Lemieux, Hélène; Hoppel, Charles L; Hanson, Richard W; Hakimi, Parvin; Croniger, Colleen M; Puchowicz, Michelle; Anderson, Vernon E; Fujioka, Hisashi; Stavnezer, Ed

    2011-11-18

    Overexpression of the Ski oncogene induces oncogenic transformation of chicken embryo fibroblasts (CEFs). However, unlike most other oncogene-transformed cells, Ski-transformed CEFs (Ski-CEFs) do not display the classical Warburg effect. On the contrary, Ski transformation reduced lactate production and glucose utilization in CEFs. Compared with CEFs, Ski-CEFs exhibited enhanced TCA cycle activity, fatty acid catabolism through β-oxidation, glutamate oxidation, oxygen consumption, as well as increased numbers and mass of mitochondria. Interestingly, expression of PPARγ, a key transcription factor that regulates adipogenesis and lipid metabolism, was dramatically elevated at both the mRNA and protein levels in Ski-CEFs. Accordingly, PPARγ target genes that are involved in lipid uptake, transport, and oxidation were also markedly up-regulated by Ski. Knocking down PPARγ in Ski-CEFs by RNA interference reversed the elevated expression of these PPARγ target genes, as well as the shift to oxidative metabolism and the increased mitochondrial biogenesis. Moreover, we found that Ski co-immunoprecipitates with PPARγ and co-activates PPARγ-driven transcription.

  6. Cell fate decisions in malignant hematopoiesis: leukemia phenotype is determined by distinct functional domains of the MN1 oncogene.

    Directory of Open Access Journals (Sweden)

    Courteney K Lai

    Full Text Available Extensive molecular profiling of leukemias and preleukemic diseases has revealed that distinct clinical entities, like acute myeloid (AML and T-lymphoblastic leukemia (T-ALL, share similar pathogenetic mutations. It is not well understood how the cell of origin, accompanying mutations, extracellular signals or structural differences in a mutated gene determine the phenotypic identity of leukemias. We dissected the functional aspects of different protein regions of the MN1 oncogene and their effect on the leukemic phenotype, building on the ability of MN1 to induce leukemia without accompanying mutations. We found that the most C-terminal region of MN1 was required to block myeloid differentiation at an early stage, and deletion of an extended C-terminal region resulted in loss of myeloid identity and cell differentiation along the T-cell lineage in vivo. Megakaryocytic/erythroid lineage differentiation was blocked by the N-terminal region. In addition, the N-terminus was required for proliferation and leukemogenesis in vitro and in vivo through upregulation of HoxA9, HoxA10 and Meis2. Our results provide evidence that a single oncogene can modulate cellular identity of leukemic cells based on its active gene regions. It is therefore likely that different mutations in the same oncogene may impact cell fate decisions and phenotypic appearance of malignant diseases.

  7. KAT6A, a Chromatin Modifier from the 8p11-p12 Amplicon is a Candidate Oncogene in Luminal Breast Cancer

    Directory of Open Access Journals (Sweden)

    Brittany Turner-Ivey

    2014-08-01

    Full Text Available The chromosome 8p11-p12 amplicon is present in 12% to 15% of breast cancers, resulting in an increase in copy number and expression of several chromatin modifiers in these tumors, including KAT6A. Previous analyses in SUM-52 breast cancer cells showed amplification and overexpression of KAT6A, and subsequent RNAi screening identified KAT6A as a potential driving oncogene. KAT6A is a histone acetyltransferase previously identified as a fusion partner with CREB binding protein in acute myeloid leukemia. Knockdown of KAT6A in SUM-52 cells, a luminal breast cancer cell line harboring the amplicon, resulted in reduced growth rate compared to non-silencing controls and profound loss of clonogenic capacity both in mono-layer and in soft agar. The normal cell line MCF10A, however, did not exhibit slower growth with knockdown of KAT6A. SUM-52 cells with KAT6A knockdown formed fewer mammospheres in culture compared to controls, suggesting a possible role for KAT6A in self-renewal. Previous data from our laboratory identified FGFR2 as a driving oncogene in SUM-52 cells. The colony forming efficiency of SUM-52 KAT6A knockdown cells in the presence of FGFR inhibition was significantly reduced compared to cells with KAT6A knockdown only. These data suggest that KAT6A may be a novel oncogene in breast cancers bearing the 8p11-p12 amplicon. While there are other putative oncogenes in the amplicon, the identification of KAT6A as a driving oncogene suggests that chromatin-modifying enzymes are a key class of oncogenes in these cancers, and play an important role in the selection of this amplicon in luminal B breast cancers.

  8. HOTAIR:an oncogenic long non-coding RNA in different cancers

    Institute of Scientific and Technical Information of China (English)

    Mohammadreza Hajjari; Abbas Salavaty

    2015-01-01

    Long non-coding RNAs (lncRNAs) refer to a group of RNAs that are usually more than 200 nucleotides and are not involved in protein generation. Instead, lncRNAs are involved in different regulatory processes, such as regulation of gene expression. Different lncRNAs exist throughout the genome. LncRNAs are also known for their roles in different human diseases such as cancer. HOTAIR is an lncRNA that plays a role as an oncogenic molecule in different cancer cells, such as breast, gastric, colorectal, and cervical cancer cells. Therefore, HOTAIR expression level is a potential biomarker for diagnostic and therapeutic purposes in several cancers. hTis RNA takes part in epigenetic regulation of genes and plays an important role in different cellular pathways by interacting with Polycomb Repressive Complex 2 (PRC2). In this review, we describe the molecular function and regulation of HOTAIR and its role in different types of cancers.

  9. The TRE17/USP6 oncogene: a riddle wrapped in a mystery inside an enigma.

    Science.gov (United States)

    Oliveira, Andre M; Chou, Margaret M

    2012-01-01

    De-ubiquitinating enzymes (DUBs) play critical roles in diverse cellular processes, including intracellular trafficking, protein turnover, inflammatory signaling, and cell transformation. The first DUB to be identified as an oncogene was TRE17/Ubiquitin-specific protease 6 (USP6)/Tre-2. In addition to encoding a USP, TRE17 also contains a TBC (Tre-2/Bub2/Cdc16) domain implicated in GTPase regulation and trafficking. Though first described almost two decades ago, remarkably little has been elucidated regarding TRE17's molecular and cellular functions. However, recent work has implicated TRE17 as a key etiological factor in aneurysmal bone cyst (ABC), a locally recurrent pediatric bone tumor, and identified potential pathways through which it acts. In this review, we discuss the most up-to-date findings on the molecular functions of TRE17, the role of its USP and TBC domains, and potential models for how it contributes to transformation and ABC pathogenesis.

  10. Genetic variations and alternative splicing. The Glioma associated oncogene 1, GLI1.

    Directory of Open Access Journals (Sweden)

    Peter eZaphiropoulos

    2012-07-01

    Full Text Available Alternative splicing is a post-transcriptional regulatory process that is attaining stronger recognition as a modulator of gene expression. Alternative splicing occurs when the primary RNA transcript is differentially processed into more than one mature RNAs. This is the result of a variable definition/inclusion of the exons, the sequences that are excised from the primary RNA to form the mature RNAs. Consequently, RNA expression can generate a collection of differentially spliced RNAs, which may distinctly influence subsequent biological events, such as protein synthesis or other biomolecular interactions. Still the mechanisms that control exon definition and exon inclusion are not fully clarified. This mini-review highlights advances in this field as well as the impact of single nucleotide polymorphisms in affecting splicing decisions. The Glioma associated oncogene 1, GLI1, is taken as an example in addressing the role of nucleotide substitutions for splicing regulation.

  11. No evidence for oncogenic mutations in the adrenocorticotropin receptor gene in human adrenocortical neoplasms

    Energy Technology Data Exchange (ETDEWEB)

    Latronico, A.C.; Reincke, M.; Mendonca, B.B. [National Inst. of Child Health and Human Development, Bethesda, MD (United States)] [and others

    1995-03-01

    The mechanism(s) of tumorigenesis for the majority of adrenocortical neoplasms remain unknown. G-Protein-coupled receptors were recently proposed as candidate protooncogenes. That activating mutations of this class of receptors might be important for tumor induction or progression of endocrine neoplasms was strengthened by the recent identification of such mutations in hyperfunctioning thyroid adenomas. To examine whether the ACTH receptor (ACTH-R) gene could be an oncogene in human adrenocortical tumors, we amplified by the polymerase chain reaction and directly sequenced the entire exon of the ACTH-R gene in 25 adrenocortical tumors (17 adenomas and 8 carcinomas) and 2 adrenocortical cancer cell lines. We found no missense point mutations or even silent polymorphisms in any of the tumors and cell lines studied. We conclude that activating mutations of the ACTH-R gene do not represent a frequent mechanism of human adrenocortical tumorigenesis. 15 refs., 2 tabs.

  12. Can plant oncogenes inhibit programmed cell death? The rolB oncogene reduces apoptosis-like symptoms in transformed plant cells.

    Science.gov (United States)

    Gorpenchenko, Tatiana Y; Aminin, Dmitry L; Vereshchagina, Yuliya V; Shkryl, Yuri N; Veremeichik, Galina N; Tchernoded, Galina K; Bulgakov, Victor P

    2012-09-01

    The rolB oncogene was previously identified as an important player in ROS metabolism in transformed plant cells. Numerous reports indicate a crucial role for animal oncogenes in apoptotic cell death. Whether plant oncogenes such as rolB can induce programmed cell death (PCD) in transformed plant cells is of particular importance. In this investigation, we used a single-cell assay based on confocal microscopy and fluorescent dyes capable of discriminating between apoptotic and necrotic cells. Our results indicate that the expression of rolB in plant cells was sufficient to decrease the proportion of apoptotic cells in steady-state conditions and diminish the rate of apoptotic cells during induced PCD. These data suggest that plant oncogenes, like animal oncogenes, may be involved in the processes mediating PCD.

  13. A ubiquitin-specific protease possesses a decisive role for adenovirus replication and oncogene-mediated transformation.

    Science.gov (United States)

    Ching, Wilhelm; Koyuncu, Emre; Singh, Sonia; Arbelo-Roman, Christina; Hartl, Barbara; Kremmer, Elisabeth; Speiseder, Thomas; Meier, Chris; Dobner, Thomas

    2013-03-01

    Adenoviral replication depends on viral as well as cellular proteins. However, little is known about cellular proteins promoting adenoviral replication. In our screens to identify such proteins, we discovered a cellular component of the ubiquitin proteasome pathway interacting with the central regulator of adenoviral replication. Our binding assays mapped a specific interaction between the N-terminal domains of both viral E1B-55K and USP7, a deubiquitinating enzyme. RNA interference-mediated downregulation of USP7 severely reduced E1B-55K protein levels, but more importantly negatively affected adenoviral replication. We also succeeded in resynthesizing an inhibitor of USP7, which like the knockdown background reduced adenoviral replication. Further assays revealed that not only adenoviral growth, but also adenoviral oncogene-driven cellular transformation relies on the functions of USP7. Our data provide insights into an intricate mechanistic pathway usurped by an adenovirus to promote its replication and oncogenic functions, and at the same time open up possibilities for new antiviral strategies.

  14. A ubiquitin-specific protease possesses a decisive role for adenovirus replication and oncogene-mediated transformation.

    Directory of Open Access Journals (Sweden)

    Wilhelm Ching

    2013-03-01

    Full Text Available Adenoviral replication depends on viral as well as cellular proteins. However, little is known about cellular proteins promoting adenoviral replication. In our screens to identify such proteins, we discovered a cellular component of the ubiquitin proteasome pathway interacting with the central regulator of adenoviral replication. Our binding assays mapped a specific interaction between the N-terminal domains of both viral E1B-55K and USP7, a deubiquitinating enzyme. RNA interference-mediated downregulation of USP7 severely reduced E1B-55K protein levels, but more importantly negatively affected adenoviral replication. We also succeeded in resynthesizing an inhibitor of USP7, which like the knockdown background reduced adenoviral replication. Further assays revealed that not only adenoviral growth, but also adenoviral oncogene-driven cellular transformation relies on the functions of USP7. Our data provide insights into an intricate mechanistic pathway usurped by an adenovirus to promote its replication and oncogenic functions, and at the same time open up possibilities for new antiviral strategies.

  15. Oncogenic intra-p53 family member interactions in human cancers

    Directory of Open Access Journals (Sweden)

    Maria eFerraiuolo

    2016-03-01

    Full Text Available The p53 gene family members p53, p73 and p63 display several isoforms derived from the presence of internal promoters and alternative splicing events. They are structural homologues but hold peculiar functional properties. p53, p73 and p63 are tumor suppressor genes that promote differentiation, senescence and apoptosis. p53, unlike p73 and p63, is frequently mutated in cancer often displaying oncogenic gain of function (GOF activities correlated with the induction of proliferation, invasion, chemoresistance and genomic instability in cancer cells. These oncogenic functions are promoted either by the aberrant transcriptional cooperation of mutant p53 (mutp53 with transcription cofactors (e.g., NF-Y, E2F1, Vitamin D Receptor (VDR, Ets-1, NF-kB and YAP or by the interaction with the p53 family members, p73 and p63, determining their functional inactivation. The instauration of these aberrant transcriptional networks leads to increased cell growth, low activation of DNA damage response pathways (DNA damage response (DDR, DNA double-strand breaks (DSBs response, enhanced invasion and high chemoresistance to different conventional chemotherapeutic treatments. Several studies have clearly shown that different cancers harboring mutant p53 proteins exhibit a poor prognosis when compared to those carrying wild type p53 (wt-p53 protein. The interference of mutantp53/p73 and/or mutantp53/p63 interactions, thereby restoring p53, p73 and p63 tumor suppression functions, could be among the potential therapeutic strategies for the treatment of mutant p53 human cancers.

  16. Discovery of a Selective Inhibitor of Oncogenic B-Raf Kinase With Potent Antimelanoma Activity

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, J.; Lee, J.T.; Wang, W.; Zhang, J.; Cho, H.; Mamo, S.; Bremer, R.; Gillette, S.; Kong, J.; Haass, N.K.; Sproesser, K.; Li, L.; Smalley, K.S.M.; Fong, D.; Zhu, Y.-L.; Marimuthu, A.; Nguyen, H.; Lam, B.; Liu, J.; Cheung, I.; Rice, J.

    2009-05-26

    BRAF{sup V600E} is the most frequent oncogenic protein kinase mutation known. Furthermore, inhibitors targeting 'active' protein kinases have demonstrated significant utility in the therapeutic repertoire against cancer. Therefore, we pursued the development of specific kinase inhibitors targeting B-Raf, and the V600E allele in particular. By using a structure-guided discovery approach, a potent and selective inhibitor of active B-Raf has been discovered. PLX4720, a 7-azaindole derivative that inhibits B-Raf{sup V600E} with an IC{sub 50} of 13 nM, defines a class of kinase inhibitor with marked selectivity in both biochemical and cellular assays. PLX4720 preferentially inhibits the active B-Raf{sup V600E} kinase compared with a broad spectrum of other kinases, and potent cytotoxic effects are also exclusive to cells bearing the V600E allele. Consistent with the high degree of selectivity, ERK phosphorylation is potently inhibited by PLX4720 in B-Raf{sup V600E}-bearing tumor cell lines but not in cells lacking oncogenic B-Raf. In melanoma models, PLX4720 induces cell cycle arrest and apoptosis exclusively in B-Raf{sup V600E}-positive cells. In B-Raf{sup V600E}-dependent tumor xenograft models, orally dosed PLX4720 causes significant tumor growth delays, including tumor regressions, without evidence of toxicity. The work described here represents the entire discovery process, from initial identification through structural and biological studies in animal models to a promising therapeutic for testing in cancer patients bearing B-Raf{sup V600E}-driven tumors.

  17. The pathobiology of the oncogenic tyrosine kinase NPM-ALK: a brief update.

    Science.gov (United States)

    Lai, Raymond; Ingham, Robert J

    2013-04-01

    Extensive research has been carried out in the past two decades to study the pathobiology of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), which is an oncogenic fusion protein found exclusively in a specific type of T-cell lymphoid malignancy, namely ALK-positive anaplastic large cell lymphoma. Results from these studies have provided highly useful insights into the mechanisms by which a constitutively tyrosine kinase, such as NPM-ALK, promotes tumorigenesis. Several previous publications have comprehensively summarized the advances in this field. In this review, we provide readers with a brief update on specific areas of NPM-ALK pathobiology. In the first part, the NPM-ALK/signal transducer and activator of transcription 3 (STAT3) signaling axis is discussed, with an emphasis on the existence of multiple biochemical defects that have been shown to amplify the oncogenic effects of this signaling axis. Specifically, findings regarding JAK3, SHP1 and the stimulatory effects of several cytokines including interleukin (IL)-9, IL-21 and IL-22 are summarized. New concepts stemming from recent observations regarding the functional interactions among the NPM-ALK/STAT3 axis, β catenin and glycogen synthase kinase 3β will be postulated. Lastly, new mechanisms by which the NPM-ALK/STAT3 axis promotes tumorigenesis, such as its modulations of Twist1, hypoxia-induced factor 1α, CD274, will be described. In the second part, we summarize recent data generated by mass spectrometry studies of NPM-ALK, and use MSH2 and heat shock proteins as examples to illustrate the use of mass spectrometry data in stimulating new research in this field. In the third part, the evolving field of microRNA in the context of NPM-ALK biology is discussed.

  18. Structural Basis of the Oncogenic Interaction of Phosphatase PRL-1 with the Magnesium Transporter CNNM2.

    Science.gov (United States)

    Giménez-Mascarell, Paula; Oyenarte, Iker; Hardy, Serge; Breiderhoff, Tilman; Stuiver, Marchel; Kostantin, Elie; Diercks, Tammo; Pey, Angel L; Ereño-Orbea, June; Martínez-Chantar, María Luz; Khalaf-Nazzal, Reham; Claverie-Martin, Felix; Müller, Dominik; Tremblay, Michel L; Martínez-Cruz, Luis Alfonso

    2017-01-20

    Phosphatases of regenerating liver (PRLs), the most oncogenic of all protein-tyrosine phosphatases (PTPs), play a critical role in metastatic progression of cancers. Recent findings established a new paradigm by uncovering that their association with magnesium transporters of the cyclin M (CNNM) family causes a rise in intracellular magnesium levels that promote oncogenic transformation. Recently, however, essential roles for regulation of the circadian rhythm and reproduction of the CNNM family have been highlighted. Here, we describe the crystal structure of PRL-1 in complex with the Bateman module of CNNM2 (CNNM2BAT), which consists of two cystathionine β-synthase (CBS) domains (IPR000664) and represents an intracellular regulatory module of the transporter. The structure reveals a heterotetrameric association, consisting of a disc-like homodimer of CNNM2BAT bound to two independent PRL-1 molecules, each one located at opposite tips of the disc. The structure highlights the key role played by Asp-558 at the extended loop of the CBS2 motif of CNNM2 in maintaining the association between the two proteins and proves that the interaction between CNNM2 and PRL-1 occurs via the catalytic domain of the phosphatase. Our data shed new light on the structural basis underlying the interaction between PRL phosphatases and CNNM transporters and provides a hypothesis about the molecular mechanism by which PRL-1, upon binding to CNNM2, might increase the intracellular concentration of Mg(2+) thereby contributing to tumor progression and metastasis. The availability of this structure sets the basis for the rational design of compounds modulating PRL-1 and CNNM2 activities.

  19. Regulation of the expression of proto-oncogenes by autocrine embryotropins in the early mouse embryo.

    Science.gov (United States)

    Jin, Xing Liang; O'Neill, C

    2011-06-01

    Autocrine embryotropins act as survival signals for the preimplantation embryo. In this study we examined the role of Paf in the transcription of the key proto-oncogenes Bcl2 and Fos. Transcripts were detected in oocytes and some cohorts of zygotes but not in cohorts of 2-cell, 8-cell, and blastocyst stage embryos. Immunolocalization of BCL2 and FOS showed little staining in oocytes and zygotes but increased staining in the embryo from the 2-cell to blastocyst stage. Paf (37 nM) treatment of 2-cell embryos caused an alpha-amanitin (26 μM)-sensitive increase in Bcl2 and Fos transcripts 20 min after treatment that subsided by 40 min. This increase was blocked by inhibition of calcium (by BAPTA-AM) or phosphatidylinositol-3-kinase signaling (by LY294002). Paf challenge also caused increased staining of BCL2 and FOS. Increased staining of FOS required new protein synthesis that had a half-life of 2-4 h after Paf challenge. Only a small proportion (∼12%) of individual 2-cell embryos collected from the reproductive tract had detectable Bcl2 and Fos. This dichotomous pattern of transcript expression is consistent with the known periodic actions of Paf (which has a periodicity of ∼90 min) and the relatively short half-life of the resulting transcripts. A BCL2 antagonist (HA14-1) caused a dose-dependent decrease in the capacity of cultured zygotes to develop to morphological blastocysts, which was partially reversed by the simultaneous addition of Paf to medium. The results show that Paf induces periodic transient transcriptions of key proto-oncogenes that result in the persistent presence of the resulting proteins in the preimplantation phase of development.

  20. The contrived mutant p53 oncogene – beyond loss of functions

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    Kanaga eSabapathy

    2015-12-01

    Full Text Available Mutations in p53 are almost synonymous with cancer - be it susceptibility to the disease or response to treatment - and therefore, are a critical determinant of overall survival. As most of these mutations occur in the DNA-binding domain of p53, many of the clinical correlations with mutant p53 have been initially relegated to the loss of its transcription-dependent activities as a tumor suppressor. However, significant efforts over the last two decades have led to the vast knowledge on the potential functions of the mutated p53 protein, that have been attributed to the physical presence of the mutant protein rather than the loss of its wild-type functions. Beyond the inhibitory effects of mutant p53 on the remaining wild-type protein that leads to the dominant-negative effect in the heterozygous state, mutant p53’s presence has also been significantly attributed to novel gain-of-functions that lead to addiction of cancer cells to its presence for survival, as well as for their ability to invade and metastasize, elevating it to a contrived oncogene that drives the cancer cells forward. This review will summarize the functional consequences of the presence of mutant p53 protein on cellular and organismal physiology.

  1. The cell survival pathways of the primordial RNA-DNA complex remain conserved in the extant genomes and may function as proto-oncogenes.

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    Sinkovics, J G

    2015-03-01

    Malignantly transformed (cancer) cells of multicellular hosts, including human cells, operate activated biochemical pathways that recognizably derived from unicellular ancestors. The descendant heat shock proteins of thermophile archaea now chaperon oncoproteins. The ABC cassettes of toxin-producer zooxantella Symbiodinia algae pump out the cytoplasmic toxin molecules; malignantly transformed cells utilize the derivatives of these cassettes to get rid of chemotherapeuticals. High mobility group helix-loop-helix proteins, protein arginine methyltransferases, proliferating cell nuclear antigens, and Ki-67 nuclear proteins, that protect and repair DNA in unicellular life forms, support oncogenes in transformed cells. The cell survival pathways of Wnt-β-catenin, Hedgehog, PI3K, MAPK-ERK, STAT, Ets, JAK, Pak, Myb, achaete scute, circadian rhythms, Bruton kinase and others, which are physiological in uni- and early multicellular eukaryotic life forms, are constitutively encoded in complex oncogenic pathways in selected single cells of advanced multicellular eukaryotic hosts. Oncogenes and oncoproteins in advanced multicellular hosts recreate selected independently living and immortalized unicellular life forms, which are similar to extinct and extant protists. These unicellular life forms are recognized at the clinics as autologous "cancer cells".

  2. Silencing of hpv16 e6 and e7 oncogenic activities by small interference rna induces autophagy and apoptosis in human cervical cancer cells

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    Jonathan Salazar-León

    2011-08-01

    Full Text Available Cervical cancer is the second most common form of death by cancer in women worldwide and has special attention for the development of new treatment strategies. Human Papilloma Virus (HPV persistent infection is the main etiological agent of this neoplasia, and the main cellular transformation mechanism is by disruption of p53 and pRb function by interaction with HPV E6 and E7 oncoproteins. This generates alterations in cellular differentiation and cellular death inhibition. Thus, HPV E6 and E7 oncogenes represent suitable targets for the development of gene therapy strategies against cervical cancer. An attractive technology platform is developing for post-transcriptional selective silencing of gene expression, using small interference RNA. Therefore, in the present study, we used SiHa cells (HPV16+ transiently transfected with specific siRNA expression plasmids for HPV16 E6 and E7 oncogenes. In this model we detected repression of E6 and E7 oncogene and oncoprotein expression, an increase in p53 and hypophosphorylated pRb isoform protein expression, and autophagy and apoptosis morphology features. These findings suggest that selective silencing of HPV16 E6 and E7 oncogenes by siRNAs, has significant biological effects on the survival of human cancer cells and is a potential gene therapy strategy against cervical cancer.

  3. Retroviruses hijack chromatin loops to drive oncogene expression and highlight the chromatin architecture around proto-oncogenic loci.

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    Jillian M Pattison

    Full Text Available The majority of the genome consists of intergenic and non-coding DNA sequences shown to play a major role in different gene regulatory networks. However, the specific potency of these distal elements as well as how these regions exert function across large genomic distances remains unclear. To address these unresolved issues, we closely examined the chromatin architecture around proto-oncogenic loci in the mouse and human genomes to demonstrate a functional role for chromatin looping in distal gene regulation. Using cell culture models, we show that tumorigenic retroviral integration sites within the mouse genome occur near existing large chromatin loops and that this chromatin architecture is maintained within the human genome as well. Significantly, as mutagenesis screens are not feasible in humans, we demonstrate a way to leverage existing screens in mice to identify disease relevant human enhancers and expose novel disease mechanisms. For instance, we characterize the epigenetic landscape upstream of the human Cyclin D1 locus to find multiple distal interactions that contribute to the complex cis-regulation of this cell cycle gene. Furthermore, we characterize a novel distal interaction upstream of the Cyclin D1 gene which provides mechanistic evidence for the abundant overexpression of Cyclin D1 occurring in multiple myeloma cells harboring a pathogenic translocation event. Through use of mapped retroviral integrations and translocation breakpoints, our studies highlight the importance of chromatin looping in oncogene expression, elucidate the epigenetic mechanisms crucial for distal cis-regulation, and in one particular instance, explain how a translocation event drives tumorigenesis through upregulation of a proto-oncogene.

  4. Retroviruses Hijack Chromatin Loops to Drive Oncogene Expression and Highlight the Chromatin Architecture around Proto-Oncogenic Loci

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    Pattison, Jillian M.; Wright, Jason B.; Cole, Michael D.

    2015-01-01

    The majority of the genome consists of intergenic and non-coding DNA sequences shown to play a major role in different gene regulatory networks. However, the specific potency of these distal elements as well as how these regions exert function across large genomic distances remains unclear. To address these unresolved issues, we closely examined the chromatin architecture around proto-oncogenic loci in the mouse and human genomes to demonstrate a functional role for chromatin looping in distal gene regulation. Using cell culture models, we show that tumorigenic retroviral integration sites within the mouse genome occur near existing large chromatin loops and that this chromatin architecture is maintained within the human genome as well. Significantly, as mutagenesis screens are not feasible in humans, we demonstrate a way to leverage existing screens in mice to identify disease relevant human enhancers and expose novel disease mechanisms. For instance, we characterize the epigenetic landscape upstream of the human Cyclin D1 locus to find multiple distal interactions that contribute to the complex cis-regulation of this cell cycle gene. Furthermore, we characterize a novel distal interaction upstream of the Cyclin D1 gene which provides mechanistic evidence for the abundant overexpression of Cyclin D1 occurring in multiple myeloma cells harboring a pathogenic translocation event. Through use of mapped retroviral integrations and translocation breakpoints, our studies highlight the importance of chromatin looping in oncogene expression, elucidate the epigenetic mechanisms crucial for distal cis-regulation, and in one particular instance, explain how a translocation event drives tumorigenesis through upregulation of a proto-oncogene. PMID:25799187

  5. Estradiol and Estrogen Receptor Agonists Oppose Oncogenic Actions of Leptin in HepG2 Cells.

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    Minqian Shen

    Full Text Available Obesity is a significant risk factor for certain cancers, including hepatocellular carcinoma (HCC. Leptin, a hormone secreted by white adipose tissue, precipitates HCC development. Epidemiology data show that men have a much higher incidence of HCC than women, suggesting that estrogens and its receptors may inhibit HCC development and progression. Whether estrogens antagonize oncogenic action of leptin is uncertain. To investigate potential inhibitory effects of estrogens on leptin-induced HCC development, HCC cell line HepG2 cells were treated with leptin in combination with 17 β-estradiol (E2, estrogen receptor-α (ER-α selective agonist PPT, ER-β selective agonist DPN, or G protein-coupled ER (GPER selective agonist G-1. Cell number, proliferation, and apoptosis were determined, and leptin- and estrogen-related intracellular signaling pathways were analyzed. HepG2 cells expressed a low level of ER-β mRNA, and leptin treatment increased ER-β expression. E2 suppressed leptin-induced HepG2 cell proliferation and promoted cell apoptosis in a dose-dependent manner. Additionally E2 reversed leptin-induced STAT3 and leptin-suppressed SOCS3, which was mainly achieved by activation of ER-β. E2 also enhanced ERK via activating ER-α and GPER and activated p38/MAPK via activating ER-β. To conclude, E2 and its receptors antagonize the oncogenic actions of leptin in HepG2 cells by inhibiting cell proliferation and stimulating cell apoptosis, which was associated with reversing leptin-induced changes in SOCS3/STAT3 and increasing p38/MAPK by activating ER-β, and increasing ERK by activating ER-α and GPER. Identifying roles of different estrogen receptors would provide comprehensive understanding of estrogenic mechanisms in HCC development and shed light on potential treatment for HCC patients.

  6. Oncogenic Ras promotes butyrate-induced apoptosis through inhibition of gelsolin expression.

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    Klampfer, Lidija; Huang, Jie; Sasazuki, Takehiko; Shirasawa, Senji; Augenlicht, Leonard

    2004-08-27

    Activation of Ras promotes oncogenesis by altering a multiple of cellular processes, such as cell cycle progression, differentiation, and apoptosis. Oncogenic Ras can either promote or inhibit apoptosis, depending on the cell type and the nature of the apoptotic stimuli. The response of normal and transformed colonic epithelial cells to the short chain fatty acid butyrate, a physiological regulator of epithelial cell maturation, is also divergent: normal epithelial cells proliferate, and transformed cells undergo apoptosis in response to butyrate. To investigate the role of k-ras mutations in butyrate-induced apoptosis, we utilized HCT116 cells, which harbor an oncogenic k-ras mutation and two isogenic clones with targeted inactivation of the mutant k-ras allele, Hkh2, and Hke-3. We demonstrated that the targeted deletion of the mutant k-ras allele is sufficient to protect epithelial cells from butyrate-induced apoptosis. Consistent with this, we showed that apigenin, a dietary flavonoid that has been shown to inhibit Ras signaling and to reverse transformation of cancer cell lines, prevented butyrate-induced apoptosis in HCT116 cells. To investigate the mechanism whereby activated k-ras sensitizes colonic cells to butyrate, we performed a genome-wide analysis of Ras target genes in the isogenic cell lines HCT116, Hkh2, and Hke-3. The gene exhibiting the greatest down-regulation by the activating k-ras mutation was gelsolin, an actin-binding protein whose expression is frequently reduced or absent in colorectal cancer cell lines and primary tumors. We demonstrated that silencing of gelsolin expression by small interfering RNA sensitized cells to butyrate-induced apoptosis through amplification of the activation of caspase-9 and caspase-7. These data therefore demonstrate that gelsolin protects cells from butyrate-induced apoptosis and suggest that Ras promotes apoptosis, at least in part, through its ability to down-regulate the expression of gelsolin.

  7. Integrin-linked kinase overexpression and its oncogenic role in promoting tumorigenicity of hepatocellular carcinoma.

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    Jenny Chan

    Full Text Available BACKGROUND: Integrin-linked kinase (ILK was first discovered as an integrin β1-subunit binding protein. It localizes at the focal adhesions and is involved in cytoskeleton remodeling. ILK overexpression and its dysregulated signaling cascades have been reported in many human cancers. Aberrant expression of ILK influenced a wide range of signaling pathways and cellular functions. Although ILK has been well characterized in many malignancies, its role in hepatocellular carcinoma (HCC is still largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Quantitative PCR analysis was used to examine ILK mRNA expression in HCC clinical samples. It was shown that ILK was overexpressed in 36.9% (21/57 of HCC tissues when compared to the corresponding non-tumorous livers. The overall ILK expression level was significantly higher in tumorous tissues (P = 0.004, with a significant stepwise increase in expression level along tumor progression from tumor stage I to IV (P = 0.045. ILK knockdown stable clones were established in two HCC cell lines, BEL7402 and HLE, and were subjected to different functional assays. Knockdown of ILK significantly suppressed HCC cell growth, motility and invasion in vitro and inhibited tumorigenicity in vivo. Western blot analysis revealed a reduced phosphorylated-Akt (pAkt at Serine-473 expression in ILK knockdown stable clones when compared to control clones. CONCLUSION/SIGNIFICANCE: This study provides evidence about the clinical relevance of ILK in hepatocarcinogenesis. ILK was found to be progressively elevated along HCC progression. Here our findings also provide the first validation about the oncogenic capacity of ILK in vivo by suppressing its expression in HCC cells. The oncogenic role of ILK is implicated to be mediated by Akt pathway.

  8. Design of a small molecule against an oncogenic noncoding RNA.

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    Velagapudi, Sai Pradeep; Cameron, Michael D; Haga, Christopher L; Rosenberg, Laura H; Lafitte, Marie; Duckett, Derek R; Phinney, Donald G; Disney, Matthew D

    2016-05-24

    The design of precision, preclinical therapeutics from sequence is difficult, but advances in this area, particularly those focused on rational design, could quickly transform the sequence of disease-causing gene products into lead modalities. Herein, we describe the use of Inforna, a computational approach that enables the rational design of small molecules targeting RNA to quickly provide a potent modulator of oncogenic microRNA-96 (miR-96). We mined the secondary structure of primary microRNA-96 (pri-miR-96) hairpin precursor against a database of RNA motif-small molecule interactions, which identified modules that bound RNA motifs nearby and in the Drosha processing site. Precise linking of these modules together provided Targaprimir-96 (3), which selectively modulates miR-96 production in cancer cells and triggers apoptosis. Importantly, the compound is ineffective on healthy breast cells, and exogenous overexpression of pri-miR-96 reduced compound potency in breast cancer cells. Chemical Cross-Linking and Isolation by Pull-Down (Chem-CLIP), a small-molecule RNA target validation approach, shows that 3 directly engages pri-miR-96 in breast cancer cells. In vivo, 3 has a favorable pharmacokinetic profile and decreases tumor burden in a mouse model of triple-negative breast cancer. Thus, rational design can quickly produce precision, in vivo bioactive lead small molecules against hard-to-treat cancers by targeting oncogenic noncoding RNAs, advancing a disease-to-gene-to-drug paradigm.

  9. Oncogenic programmes and Notch activity: an 'organized crime'?

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    Dominguez, Maria

    2014-04-01

    The inappropriate Notch signalling can influence virtually all aspect of cancer, including tumour-cell growth, survival, apoptosis, angiogenesis, invasion and metastasis, although it does not do this alone. Hence, elucidating the partners of Notch that are active in cancer is now the focus of much intense research activity. The genetic toolkits available, coupled to the small size and short life of the fruit fly Drosophila melanogaster, makes this an inexpensive and effective animal model, suited to large-scale cancer gene discovery studies. The fly eye is not only a non-vital organ but its stereotyped size and disposition also means it is easy to screen for mutations that cause tumours and metastases and provides ample opportunities to test cancer theories and to unravel unanticipated nexus between Notch and other cancer genes, or to discover unforeseen Notch's partners in cancer. These studies suggest that Notch's oncogenic capacity is brought about not simply by increasing signal strength but through partnerships, whereby oncogenes gain more by cooperating than acting individually, as in a ring 'organized crime'.

  10. REST regulates oncogenic properties of glioblastoma stem cells

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    Kamal, Mohamed M.; Sathyan, Pratheesh; Singh, Sanjay K.; Zinn, Pascal O.; Marisetty, Anantha L.; Liang, Shoudan; Gumin, Joy; El-Mesallamy, Hala Osman; Suki, Dima; Colman, Howard; Fuller, Gregory N.; Lang, Frederick F.; Majumder, Sadhan

    2013-01-01

    Glioblastoma multiforme (GBM) tumors are the most common malignant primary brain tumors in adults. Although many GBM tumors are believed to be caused by self-renewing, glioblastoma-derived stem-like cells (GSCs), the mechanisms that regulate self-renewal and other oncogenic properties of GSCs are only now being unraveled. Here we showed that GSCs derived from GBM patient specimens express varying levels of the transcriptional repressor REST, suggesting heterogeneity across different GSC lines. Loss- and gain-of-function experiments indicated that REST maintains self-renewal of GSCs. High REST-expressing GSCs (HR-GSCs) produced tumors histopathologically distinct from those generated by low REST-expressing GSCs (LR-GSCs) in orthotopic mouse brain tumor models. Knockdown of REST in HR-GSCs resulted in increased survival in GSC-transplanted mice and produced tumors with higher apoptotic and lower invasive properties. Conversely, forced expression of exogenous REST in LR-GSCs produced decreased survival in mice and produced tumors with lower apoptotic and higher invasive properties, similar to HR-GSCs. Thus, based on our results, we propose that a novel function of REST is to maintain self-renewal and other oncogenic properties of GSCs and that REST can play a major role in mediating tumorigenicity in GBM. PMID:22228704

  11. Metastatic pancreatic cancer is dependent on oncogenic Kras in mice.

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    Meredith A Collins

    Full Text Available Pancreatic cancer is one of the deadliest human malignancies, and its prognosis has not improved over the past 40 years. Mouse models that spontaneously develop pancreatic adenocarcinoma and mimic the progression of the human disease are emerging as a new tool to investigate the basic biology of this disease and identify potential therapeutic targets. Here, we describe a new model of metastatic pancreatic adenocarcinoma based on pancreas-specific, inducible and reversible expression of an oncogenic form of Kras, together with pancreas-specific expression of a mutant form of the tumor suppressor p53. Using high-resolution magnetic resonance imaging to follow individual animals in longitudinal studies, we show that both primary and metastatic lesions depend on continuous Kras activity for their maintenance. However, re-activation of Kras* following prolonged inactivation leads to rapid tumor relapse, raising the concern that Kras*-resistance might eventually be acquired. Thus, our data identifies Kras* as a key oncogene in pancreatic cancer maintenance, but raises the possibility of acquired resistance should Kras inhibitors become available for use in pancreatic cancer.

  12. Oncogenes Activate an Autonomous Transcriptional Regulatory Circuit That Drives Glioblastoma

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    Dinesh K. Singh

    2017-01-01

    Full Text Available Efforts to identify and target glioblastoma (GBM drivers have primarily focused on receptor tyrosine kinases (RTKs. Clinical benefits, however, have been elusive. Here, we identify an SRY-related box 2 (SOX2 transcriptional regulatory network that is independent of upstream RTKs and capable of driving glioma-initiating cells. We identified oligodendrocyte lineage transcription factor 2 (OLIG2 and zinc-finger E-box binding homeobox 1 (ZEB1, which are frequently co-expressed irrespective of driver mutations, as potential SOX2 targets. In murine glioma models, we show that different combinations of tumor suppressor and oncogene mutations can activate Sox2, Olig2, and Zeb1 expression. We demonstrate that ectopic co-expression of the three transcription factors can transform tumor-suppressor-deficient astrocytes into glioma-initiating cells in the absence of an upstream RTK oncogene. Finally, we demonstrate that the transcriptional inhibitor mithramycin downregulates SOX2 and its target genes, resulting in markedly reduced proliferation of GBM cells in vivo.

  13. Oncogenes Activate an Autonomous Transcriptional Regulatory Circuit That Drives Glioblastoma.

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    Singh, Dinesh K; Kollipara, Rahul K; Vemireddy, Vamsidara; Yang, Xiao-Li; Sun, Yuxiao; Regmi, Nanda; Klingler, Stefan; Hatanpaa, Kimmo J; Raisanen, Jack; Cho, Steve K; Sirasanagandla, Shyam; Nannepaga, Suraj; Piccirillo, Sara; Mashimo, Tomoyuki; Wang, Shan; Humphries, Caroline G; Mickey, Bruce; Maher, Elizabeth A; Zheng, Hongwu; Kim, Ryung S; Kittler, Ralf; Bachoo, Robert M

    2017-01-24

    Efforts to identify and target glioblastoma (GBM) drivers have primarily focused on receptor tyrosine kinases (RTKs). Clinical benefits, however, have been elusive. Here, we identify an SRY-related box 2 (SOX2) transcriptional regulatory network that is independent of upstream RTKs and capable of driving glioma-initiating cells. We identified oligodendrocyte lineage transcription factor 2 (OLIG2) and zinc-finger E-box binding homeobox 1 (ZEB1), which are frequently co-expressed irrespective of driver mutations, as potential SOX2 targets. In murine glioma models, we show that different combinations of tumor suppressor and oncogene mutations can activate Sox2, Olig2, and Zeb1 expression. We demonstrate that ectopic co-expression of the three transcription factors can transform tumor-suppressor-deficient astrocytes into glioma-initiating cells in the absence of an upstream RTK oncogene. Finally, we demonstrate that the transcriptional inhibitor mithramycin downregulates SOX2 and its target genes, resulting in markedly reduced proliferation of GBM cells in vivo.

  14. The Heterodimeric TWIST1-E12 Complex Drives the Oncogenic Potential of TWIST1 in Human Mammary Epithelial Cells

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    Laurent Jacqueroud

    2016-05-01

    Full Text Available The TWIST1 embryonic transcription factor displays biphasic functions during the course of carcinogenesis. It facilitates the escape of cells from oncogene-induced fail-safe programs (senescence, apoptosis and their consequent neoplastic transformation. Additionally, it promotes the epithelial-to-mesenchymal transition and the initiation of the metastatic spread of cancer cells. Interestingly, cancer cells recurrently remain dependent on TWIST1 for their survival and/or proliferation, making TWIST1 their Achilles’ heel. TWIST1 has been reported to form either homodimeric or heterodimeric complexes mainly in association with the E bHLH class I proteins. These complexes display distinct, sometimes even antagonistic, functions during development and unequal prometastatic functions in prostate cancer cells. Using a tethered dimer strategy, we successively assessed the ability of TWIST1 dimers to cooperate with an activated version of RAS in human mammary epithelial cell transformation, to provide mice with the ability to spontaneously develop breast tumors, and lastly to maintain a senescence program at a latent state in several breast cancer cell lines. We demonstrate that the TWIST1-E12 complex, unlike the homodimer, is an oncogenic form of TWIST1 in mammary epithelial cells and that efficient binding of both partners is a prerequisite for its activity. The detection of the heterodimer in human premalignant lesions by a proximity ligation assay, at a stage preceding the initiation of the metastatic cascade, is coherent with such an oncogenic function. TWIST1-E protein heterodimeric complexes may thus constitute the main active forms of TWIST1 with regard to senescence inhibition over the time course of breast tumorigenesis.

  15. Arsenic trioxide inhibits cell proliferation and human papillomavirus oncogene expression in cervical cancer cells.

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    Wang, Hongtao; Gao, Peng; Zheng, Jie

    2014-09-05

    Arsenic trioxide (As2O3) has shown therapeutic effects in some leukemias and solid cancers. However, the molecular mechanisms of its anticancer efficacy have not been clearly elucidated, particularly in solid cancers. Our previous data showed that As2O3 induced apoptosis of human papillomavirus (HPV) 16 DNA-immortalized human cervical epithelial cells and cervical cancer cells and inhibited the expression of HPV oncogenes in these cells. In the present study, we systemically examined the effects of As2O3 on five human cervical cancer cell lines and explored the possible molecular mechanisms. MTT assay showed that HPV-negative C33A cells were more sensitive to growth inhibition induced by As2O3 than HPV-positive cervical cancer cells, and HPV 18-positive HeLa and C4-I cells were more sensitive to As2O3 than HPV 16-positive CaSki and SiHa cells. After As2O3 treatment, both mRNA and protein levels of HPV E6 and E7 obviously decreased in all HPV positive cell lines. In contrast, p53 and Rb protein levels increased in all tested cell lines. Transcription factor AP-1 protein expression decreased significantly in HeLa, CaSki and C33A cells with ELISA method. These results suggest that As2O3 is a potential anticancer drug for cervical cancer.

  16. Transcription-induced DNA double strand breaks: both oncogenic force and potential therapeutic target?

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    Haffner, Michael C; De Marzo, Angelo M; Meeker, Alan K; Nelson, William G; Yegnasubramanian, Srinivasan

    2011-06-15

    An emerging model of transcriptional activation suggests that induction of transcriptional programs, for instance by stimulating prostate or breast cells with androgens or estrogens, respectively, involves the formation of DNA damage, including DNA double strand breaks (DSB), recruitment of DSB repair proteins, and movement of newly activated genes to transcription hubs. The DSB can be mediated by the class II topoisomerase TOP2B, which is recruited with the androgen receptor and estrogen receptor to regulatory sites on target genes and is apparently required for efficient transcriptional activation of these genes. These DSBs are recognized by the DNA repair machinery triggering the recruitment of repair proteins such as poly(ADP-ribose) polymerase 1 (PARP1), ATM, and DNA-dependent protein kinase (DNA-PK). If illegitimately repaired, such DSBs can seed the formation of genomic rearrangements like the TMPRSS2-ERG fusion oncogene in prostate cancer. Here, we hypothesize that these transcription-induced, TOP2B-mediated DSBs can also be exploited therapeutically and propose that, in hormone-dependent tumors like breast and prostate cancers, a hormone-cycling therapy, in combination with topoisomerase II poisons or inhibitors of the DNA repair components PARP1 and DNA-PK, could overwhelm cancer cells with transcription-associated DSBs. Such strategies may find particular utility in cancers, like prostate cancer, which show low proliferation rates, in which other chemotherapeutic strategies that target rapidly proliferating cells have had limited success.

  17. TP53 GENE MUTATIONS – FROM GUARDIAN OF THE GENOME TO ONCOGENE

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    Petar Babović

    2010-03-01

    Full Text Available TP53 tumor suppressor gene mutations are the most frequent genetic alterations in human cancer affecting a specific gene. The occurrence of TP53 mutations is considerably influenced by cancer-initiating events, such as DNA damage, the aftermath of which is the promotion of cancer development through the loss of anti-proliferative activities, including apoptosis and cellular senescence. Over 27.000 TP53 gene mutations have been discovered and found in more than 50% of human cancers. The most frequent alterations are the point mutations with a single base substitution in gene segment encoding for DNA-binding domaine of p53 molecule, leading to the production of mutant protein that differs from the wild-type protein by one amino acid (missense mutations usually causing the change in tertiary structure of gene product, thus preventing p53 to bind to DNA and activate transcription of target genes. The result of the mutations may also be the proteins with new, abnormal functions, and the ability to modulate expression of genes responsible for neoangiogenesis, resistance to chemotherapeutics and prevention of tumor initiation and promotion. In such circumstances, not only the mutant TP53 loses its tumor suppressive function, but acquires oncogenic potential and becomes an active participant in the neoplastic transformation of the cell.Vast heterogeneity of mutations and methodological approaches in p53 status assessment represent the main difficulties in rapid and effective integration of basic p53 research into clinical practice.

  18. Orphan receptor GPR110, an oncogene overexpressed in lung and prostate cancer

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    Channa Namitha

    2010-02-01

    Full Text Available Abstract Background GPR110 is an orphan G protein-coupled receptor--a receptor without a known ligand, a known signaling pathway, or a known function. Despite the lack of information, one can assume that orphan receptors have important biological roles. In a retroviral insertion mutagenesis screen in the mouse, we identified GPR110 as an oncogene. This prompted us to study the potential isoforms that can be gleaned from known GPR110 transcripts, and the expression of these isoforms in normal and transformed human tissues. Methods Various epitope-tagged isoforms of GPR110 were expressed in cell lines and assayed by western blotting to determine cleavage, surface localization, and secretion patterns. GPR110 transcript and protein levels were measured in lung and prostate cancer cell lines and clinical samples, respectively, by quantitative PCR and immunohistochemistry. Results We found four potential splice variants of GPR110. Of these variants, we confirmed three as being expressed as proteins on the cell surface. Isoform 1 is the canonical form, with a molecular mass of about 100 kD. Isoforms 2 and 3 are truncated products of isoform 1, and are 25 and 23 kD, respectively. These truncated isoforms lack the seven-span transmembrane domain characteristic of GPR proteins and thus are not likely to be membrane anchored; indeed, isoform 2 can be secreted. Compared with the median gene expression of ~200 selected genes, GPR110 expression was low in most tissues. However, it had higher than average gene expression in normal kidney tissue and in prostate tissues originating from older donors. Although identified as an oncogene in murine T lymphomas, GPR110 is greatly overexpressed in human lung and prostate cancers. As detected by immunohistochemistry, GPR110 was overexpressed in 20 of 27 (74% lung adenocarcinoma tissue cores and in 17 of 29 (59% prostate adenocarcinoma tissue cores. Additionally, staining with a GPR110 antibody enabled us to

  19. MicroRNA-205 downregulates mixed-lineage-AF4 oncogene expression in acute lymphoblastic leukemia

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    Dou L

    2013-08-01

    Full Text Available Liping Dou,1,* Jingxin Li,1,* Dehua Zheng,2,* Yonghui Li,1 Xiaoning Gao,1 Chengwang Xu,1 Li Gao,1 Lili Wang,1 Li Yu1 1Department of Hematology, Chinese PLA General Hospital, Beijing, People's Republic of China; 2Department of Hepatobiliary Surgery, Organ Transplant Center, Chinese PLA 309th Hospital, Beijing, People's Republic of China*These authors contributed equally to this workAbstract: Myeloid/lymphoid or mixed-lineage AF4 acute lymphoblastic leukemia (MLL-AF4 ALL is a pediatric leukemia that occurs rarely in adults. MLL-AF4 ALL is typically characterized by the presence of chromosomal translocation (t(4;11(q21;q23, leading to expression of MLL-AF4 fusion protein. Although MLL-AF4 fusion protein triggers a molecular pathogenesis and hematological presentations that are unique to leukemias, the precise role of this oncogene in leukemogenesis remains unclear. Previous studies have indicated that microRNAs (miRs might modulate the expression of MLL-AF4 ALL fusion protein, thereby suggesting the involvement of miR in progression or suppression of MLL-AF4 ALL. We have previously demonstrated that miR-205 negatively regulates transcription of an MLL-AF4 luciferase reporter. Here, we report that exogenous expression of miR-205 in MLL-AF4 human cell lines (RS4;11 and MV4-11 inversely regulates the expression of MLL-AF4 at both messenger RNA (mRNA and protein level. Furthermore, miR-205 significantly induced apoptosis in MLL-AF4 cells as evidenced by Annexin V staining using fluorescence-activated cell sorting (FACS analysis. The proliferative capacity of leukemic cells was suppressed by miR-205. The addition of an miR-205 inhibitor was able to restore the observed effects. In conclusion, these findings demonstrate that miR-205 may have potential value as a novel therapeutic agent in the treatment of MLL-AF4 ALL.Keywords: miR-205, MLL-AF4, leukemia, microRNA, oncogene expression, untranslated regions, proliferation

  20. [Nature of cancer explored from the perspective of the functional evolution of proto-oncogenes].

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    Watari, Akihiro

    2012-01-01

    The products of proto-oncogene play critical roles in the development or maintenance of multicellular societies in animals via strict regulatory systems. When these regulatory systems are disrupted, proto-oncogenes can become oncogenes, and thereby induce cell transformation and carcinogenesis. To understand the molecular basis for development of the regulatory system of proto-oncogenes during evolution, we screened for ancestral proto-oncogenes from the unicellular choanoflagellate Monosiga ovata (M. ovata) by monitoring their transforming ability in mammalian cells; consequently, we isolated a Pak gene ortholog, which encodes a serine/threonine kinase as a 'primitive oncogene'. We also cloned Pak orthologs from fungi and the multicellular sponge Ephydatia fluviatilis, and compared their regulatory features with that of M. ovata Pak (MoPak). MoPak is constitutively active and induces cell transformation in mammalian cells. In contrast, Pak orthologs from multicellular animals are strictly regulated. Analyses of Pak mutants revealed that structural alterations in the auto-inhibitory domain (AID) are responsible for the enhanced kinase activity and the oncogenic activity of MoPak. Furthermore, we show that Rho family GTPases-mediated regulatory system of Pak kinase is conserved throughout the evolution from unicellular to multicellular animals, but the MoPak is more sensitive to the Rho family GTPases-mediated activation than multicellular Pak. These results show that maturation of AID function was required for the development of the strict regulatory system of the Pak proto-oncogene, and support the potential link between the development of the regulatory system of proto-oncogenes and the evolution of multicellularity. Further analysis of oncogenic functions of proto-oncogene orthologs in the unicellular genes would provide some insights into the mechanisms of the destruction of multicellular society in cancer.

  1. Functional Analysis of the Proto-oncogenes Septin9 and Nras

    DEFF Research Database (Denmark)

    Lassen, Louise Berkhoudt

    regardless of genotype indicating an oncogenic role of SEPT9. Nras is a potent proto-oncogene involved in signaling through a number of proliferative pathways. Earlier detected retroviral integration sites resulting in B-cell lymphomas were used to create Nras knock in models harboring the LTR from...

  2. RET oncogene in MEN2, MEN2B, MTC and other forms of thyroid cancer.

    Science.gov (United States)

    Lodish, Maya B; Stratakis, Constantine A

    2008-04-01

    Hereditary medullary thyroid carcinoma (MTC) is caused by specific autosomal dominant gain-of-function mutations in the RET proto-oncogene. Genotype-phenotype correlations exist that help predict the presence of other associated endocrine neoplasms as well as the timing of thyroid cancer development. MTC represents a promising model for targeted cancer therapy, as the oncogenic event responsible for initiating malignancy has been well characterized. The RET proto-oncogene has become the target for molecularly designed drug therapy. Tyrosine kinase inhibitors targeting activated RET are currently in clinical trials for the treatment of patients with MTC. This review will provide a brief overview of MTC and the associated RET oncogenic mutations, and will summarize the therapies designed to strategically interfere with the pathologic activation of the RET oncogene.

  3. Classical Oncogenes and Tumor Suppressor Genes: A Comparative Genomics Perspective

    Directory of Open Access Journals (Sweden)

    Oxana K. Pickeral

    2000-05-01

    Full Text Available We have curated a reference set of cancer-related genes and reanalyzed their sequences in the light of molecular information and resources that have become available since they were first cloned. Homology studies were carried out for human oncogenes and tumor suppressors, compared with the complete proteome of the nematode, Caenorhabditis elegans, and partial proteomes of mouse and rat and the fruit fly, Drosophila melanogaster. Our results demonstrate that simple, semi-automated bioinformatics approaches to identifying putative functionally equivalent gene products in different organisms may often be misleading. An electronic supplement to this article1 provides an integrated view of our comparative genomics analysis as well as mapping data, physical cDNA resources and links to published literature and reviews, thus creating a “window” into the genomes of humans and other organisms for cancer biology.

  4. Mutations of the KRAS oncogene in endometrial hyperplasia and carcinoma.

    Directory of Open Access Journals (Sweden)

    Wiesława Niklińska

    2009-05-01

    Full Text Available The aim of this study was to examine the prevalence and clinicopathological significance of KRAS point mutation in endometrial hyperplasia and carcinoma. We analysed KRAS in 11 cases of complex atypical hyperplasia and in 49 endometrial carcinomas using polymerase chain reaction associated with restriction fragment length polymorphism (PCR-RFPL. Point mutations at codon 12 of KRAS oncogene were identified in 7 of 49 (14,3% tumor specimens and in 2 of 11 (18,2% hyperplasias. No correlation was found between KRAS gene mutation and age at onset, histology, grade of differentiation and clinical stage. We conclude that KRAS mutation is a relatively common event in endometrial carcinogenesis, but with no prognostic value.

  5. Structural Effects of Oncogenic PI3K alpha Mutations

    Energy Technology Data Exchange (ETDEWEB)

    S Gabelli; C Huang; D Mandelker; O Schmidt-Kittler; B Vogelstein; L Amzel

    2011-12-31

    Physiological activation of PI3K{alpha} is brought about by the release of the inhibition by p85 when the nSH2 binds the phosphorylated tyrosine of activated receptors or their substrates. Oncogenic mutations of PI3K{alpha} result in a constitutively activated enzyme that triggers downstream pathways that increase tumor aggressiveness and survival. Structural information suggests that some mutations also activate the enzyme by releasing p85 inhibition. Other mutations work by different mechanisms. For example, the most common mutation, His1047Arg, causes a conformational change that increases membrane association resulting in greater accessibility to the substrate, an integral membrane component. These effects are examples of the subtle structural changes that result in increased activity. The structures of these and other mutants are providing the basis for the design of isozyme-specific, mutation-specific inhibitors for individualized cancer therapies.

  6. Oncogenes, protooncogenes, and tumor suppressor genes in acute myelogenous leukemia.

    Science.gov (United States)

    Hijiya, N; Gewirtz, A M

    1995-05-01

    In recent years, our understanding of normal human hematopoiesis has expanded greatly. We have increased our knowledge of regulatory growth factors, the receptors through which they act, and the secondary messengers involved in transducing the growth/differentiation signals from the cytoplasmic membrane to the nucleus. This knowledge has revealed potential mechanisms for inducing the neoplastic transformation of hematopoietic cells. This applies in particular to the role of viral oncogenes and cellular protooncogenes and, more recently, to the role of tumor suppressor genes. Protooncogenes are intimately involved in the processes of cell proliferation and differentiation. Therefore, any amplification, mutation, structural alteration, or change in transcriptional regulation of protooncogenes might lead to or be associated with induction of the malignant phenotype. Based on the importance of these genes in leukemogenesis and the maintenance of the malignant phenotype, it seems reasonable to hypothesize that targeted disruption of leukemogenic genes may be of therapeutic value.

  7. Terminal and progenitor lineage-survival oncogenes as cancer markers.

    Science.gov (United States)

    Vias, Maria; Ramos-Montoya, Antonio; Mills, Ian G

    2008-11-01

    Tumour classification has traditionally focused on differentiation and cellular morphology, and latterly on the application of genomic approaches. By combining chromatin immunoprecipitation with expression array, it has been possible to identify direct gene targets for transcription factors for nuclear hormone receptors. At the same time, there have been great strides in deriving stem and progenitor cells from tissues. It is therefore timely to propose that pairing the isolation of these cell subpopulations from tissues and tumours with these genomics approaches will reveal conserved gene targets for transcription factors. By focusing on transcription factors (lineage-survival oncogenes) with roles in both organogenesis and tumourigenesis at multiple organ sites, we suggest that this comparative genomics approach will enable developmental biology to be used more fully in relation to understanding tumour progression and will reveal new cancer markers. We focus here on neurogenesis and neuroendocrine differentiation in tumours.

  8. Use of glycolytic pathways for inhibiting or measuring oncogenic signaling

    Energy Technology Data Exchange (ETDEWEB)

    Onodera, Yasuhito; Bissell, Mina

    2017-06-27

    Disclosed are methods in which glucose metabolism is correlated to oncogenesis through certain specific pathways; inhibition of certain enzymes is shown to interfere with oncogenic signaling, and measurement of certain enzyme levels is correlated with patient survival. The present methods comprise measuring level of expression of at least one of the enzymes involved in glucose uptake or metabolism, wherein increased expression of the at least one of the enzymes relative to expression in a normal cell correlates with poor prognosis of disease in a patient. Preferably the genes whose expression level is measured include GLUT3, PFKP, GAPDH, ALDOC, LDHA and GFPT2. Also disclosed are embodiments directed towards downregulating the expression of some genes in glucose uptake and metabolism.

  9. Tumor-derived exosomes in oncogenic reprogramming and cancer progression.

    Science.gov (United States)

    Saleem, Sarmad N; Abdel-Mageed, Asim B

    2015-01-01

    In multicellular organisms, effective communication between cells is a crucial part of cellular and tissue homeostasis. This communication mainly involves direct cell-cell contact as well as the secretion of molecules that bind to receptors at the recipient cells. However, a more recently characterized mode of intercellular communication-the release of membrane vesicles known as exosomes-has been the subject of increasing interest and intensive research over the past decade. Following the discovery of the exosome-mediated immune activation, the pathophysiological roles of exosomes have been recognized in different diseases, including cancer. In this review, we describe the biogenesis and main physical characteristics that define exosomes as a specific population of secreted vesicles, with a special focus on their role in oncogenic transformation and cancer progression.

  10. Structural effects of oncogenic PI3Kα mutations.

    Science.gov (United States)

    Gabelli, Sandra B; Huang, Chuan-Hsiang; Mandelker, Diana; Schmidt-Kittler, Oleg; Vogelstein, Bert; Amzel, L Mario

    2010-01-01

    Physiological activation of PI3Kα is brought about by the release of the inhibition by p85 when the nSH2 binds the phosphorylated tyrosine of activated receptors or their substrates. Oncogenic mutations of PI3Kα result in a constitutively activated enzyme that triggers downstream pathways that increase tumor aggressiveness and survival. Structural information suggests that some mutations also activate the enzyme by releasing p85 inhibition. Other mutations work by different mechanisms. For example, the most common mutation, His1047Arg, causes a conformational change that increases membrane association resulting in greater accessibility to the substrate, an integral membrane component. These effects are examples of the subtle structural changes that result in increased activity. The structures of these and other mutants are providing the basis for the design of isozyme-specific, mutation-specific inhibitors for individualized cancer therapies.

  11. Deciphering hepatocellular responses to metabolic and oncogenic stress

    Directory of Open Access Journals (Sweden)

    Kathrina L. Marcelo

    2015-08-01

    Full Text Available Each cell type responds uniquely to stress and fractionally contributes to global and tissue-specific stress responses. Hepatocytes, liver macrophages (MΦ, and sinusoidal endothelial cells (SEC play functionally important and interdependent roles in adaptive processes such as obesity and tumor growth. Although these cell types demonstrate significant phenotypic and functional heterogeneity, their distinctions enabling disease-specific responses remain understudied. We developed a strategy for the simultaneous isolation and quantification of these liver cell types based on antigenic cell surface marker expression. To demonstrate the utility and applicability of this technique, we quantified liver cell-specific responses to high-fat diet (HFD or diethylnitrosamine (DEN, a liver-specific carcinogen, and found that while there was only a marginal increase in hepatocyte number, MΦ and SEC populations were quantitatively increased. Global gene expression profiling of hepatocytes, MΦ and SEC identified characteristic gene signatures that define each cell type in their distinct physiological or pathological states. Integration of hepatic gene signatures with available human obesity and liver cancer microarray data provides further insight into the cell-specific responses to metabolic or oncogenic stress. Our data reveal unique gene expression patterns that serve as molecular “fingerprints” for the cell-centric responses to pathologic stimuli in the distinct microenvironment of the liver. The technical advance highlighted in this study provides an essential resource for assessing hepatic cell-specific contributions to metabolic and oncogenic stress, information that could unveil previously unappreciated molecular mechanisms for the cellular crosstalk that underlies the continuum from metabolic disruption to obesity and ultimately hepatic cancer.

  12. Nucleolus-derived mediators in oncogenic stress response and activation of p53-dependent pathways.

    Science.gov (United States)

    Stępiński, Dariusz

    2016-08-01

    Rapid growth and division of cells, including tumor ones, is correlated with intensive protein biosynthesis. The output of nucleoli, organelles where translational machineries are formed, depends on a rate of particular stages of ribosome production and on accessibility of elements crucial for their effective functioning, including substrates, enzymes as well as energy resources. Different factors that induce cellular stress also often lead to nucleolar dysfunction which results in ribosome biogenesis impairment. Such nucleolar disorders, called nucleolar or ribosomal stress, usually affect cellular functioning which in fact is a result of p53-dependent pathway activation, elicited as a response to stress. These pathways direct cells to new destinations such as cell cycle arrest, damage repair, differentiation, autophagy, programmed cell death or aging. In the case of impaired nucleolar functioning, nucleolar and ribosomal proteins mediate activation of the p53 pathways. They are also triggered as a response to oncogenic factor overexpression to protect tissues and organs against extensive proliferation of abnormal cells. Intentional impairment of any step of ribosome biosynthesis which would direct the cells to these destinations could be a strategy used in anticancer therapy. This review presents current knowledge on a nucleolus, mainly in relation to cancer biology, which is an important and extremely sensitive element of the mechanism participating in cellular stress reaction mediating activation of the p53 pathways in order to counteract stress effects, especially cancer development.

  13. Ras CAAX peptidomimetic FTI-277 selectively blocks oncogenic Ras signaling by inducing cytoplasmic accumulation of inactive Ras-Raf complexes.

    Science.gov (United States)

    Lerner, E C; Qian, Y; Blaskovich, M A; Fossum, R D; Vogt, A; Sun, J; Cox, A D; Der, C J; Hamilton, A D; Sebti, S M

    1995-11-10

    Ras-induced malignant transformation requires Ras farnesylation, a lipid posttranslational modification catalyzed by farnesyltransferase (FTase). Inhibitors of this enzyme have been shown to block Ras-dependent transformation, but the mechanism by which this occurs remains largely unknown. We have designed FTI-276, a peptide mimetic of the COOH-terminal Cys-Val-Ile-Met of K-Ras4B that inhibited potently FTase in vitro (IC50 = 500 pM) and was highly selective for FTase over geranylgeranyltransferase I (GGTase I) (IC50 = 50 nM). FTI-277, the methyl ester derivative of FTI-276, was extremely potent (IC50 = 100 nM) at inhibiting H-Ras, but not the geranylgeranylated Rap1A processing in whole cells. Treatment of H-Ras oncogene-transformed NIH 3T3 cells with FTI-277 blocked recruitment to the plasma membrane and subsequent activation of the serine/threonine kinase c-Raf-1 in cells transformed by farnesylated Ras (H-RasF), but not geranylgeranylated, Ras (H-RasGG). FTI-277 induced accumulation of cytoplasmic non-farnesylated H-Ras that was able to bind Raf and form cytoplasmic Ras/Raf complexes in which Raf kinase was not activated. Furthermore, FTI-277 blocked constitutive activation of mitogen-activated protein kinase (MAPK) in H-RasF, but not H-RasGG, or Raf-transformed cells. FTI-277 also inhibited oncogenic K-Ras4B processing and constitutive activation of MAPK, but the concentrations required were 100-fold higher than those needed for H-Ras inhibition. The results demonstrate that FTI-277 blocks Ras oncogenic signaling by accumulating inactive Ras/Raf complexes in the cytoplasm, hence preventing constitutive activation of the MAPK cascade.

  14. RUNX1 is required for oncogenic Myb and Myc enhancer activity in T cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Choi, AHyun; Illendula, Anuradha; Pulikkan, John A; Roderick, Justine E; Tesell, Jessica; Yu, Jun; Hermance, Nicole; Zhu, Lihua Julie; Castilla, Lucio H; Bushweller, John H; Kelliher, Michelle A

    2017-08-08

    The gene encoding the RUNX1 transcription factor is mutated in a subset of T cell acute lymphoblastic leukemia (T-ALL) patients and RUNX1 mutations are associated with a poor prognosis. These mutations cluster in the DNA binding Runt domain, are thought to represent loss-of-function mutations, indicating that RUNX1 suppresses T cell transformation. RUNX1 has been proposed to have tumor suppressor roles in TLX1/3 transformed human T-ALL cell lines and NOTCH1 T-ALL mouse models. Yet retroviral insertional mutagenesis screens identify RUNX genes as collaborating oncogenes in MYC-driven leukemia mouse models. To elucidate RUNX1 function(s) in leukemogenesis, we generated Tal1/Lmo2/Rosa26-CreER(T2)Runx1(f/f) mice and examined leukemia progression in the presence of vehicle or tamoxifen. We found that Runx1 deletion inhibits mouse leukemic growth in vivo and that RUNX silencing in human T-ALL cells triggers apoptosis. We demonstrate that a small molecule inhibitor, designed to interfere with CBFβ binding to RUNX proteins, impairs the growth of human T-ALL cell lines and primary patient samples. We demonstrate that a RUNX1 deficiency alters the expression of a crucial subset of TAL1- and NOTCH1-regulated genes including the MYB and MYC oncogenes, respectively. These studies provide genetic and pharmacologic evidence that RUNX1 has oncogenic roles and reveal RUNX1 as a novel therapeutic target in T-ALL. Copyright © 2017 American Society of Hematology.

  15. Simultaneous inhibition of multiple oncogenic miRNAs by a multi-potent microRNA sponge.

    Science.gov (United States)

    Jung, Jaeyun; Yeom, Chanjoo; Choi, Yeon-Sook; Kim, Sinae; Lee, EunJi; Park, Min Ji; Kang, Sang Wook; Kim, Sung Bae; Chang, Suhwan

    2015-08-21

    The roles of oncogenic miRNAs are widely recognized in many cancers. Inhibition of single miRNA using antagomiR can efficiently knock-down a specific miRNA. However, the effect is transient and often results in subtle phenotype, as there are other miRNAs contribute to tumorigenesis. Here we report a multi-potent miRNA sponge inhibiting multiple miRNAs simultaneously. As a model system, we targeted miR-21, miR-155 and miR-221/222, known as oncogenic miRNAs in multiple tumors including breast and pancreatic cancers. To achieve efficient knockdown, we generated perfect and bulged-matched miRNA binding sites (MBS) and introduced multiple copies of MBS, ranging from one to five, in the multi-potent miRNA sponge. Luciferase reporter assay showed the multi-potent miRNA sponge efficiently inhibited 4 miRNAs in breast and pancreatic cancer cells. Furthermore, a stable and inducible version of the multi-potent miRNA sponge cell line showed the miRNA sponge efficiently reduces the level of 4 target miRNAs and increase target protein level of these oncogenic miRNAs. Finally, we showed the miRNA sponge sensitize cells to cancer drug and attenuate cell migratory activity. Altogether, our study demonstrates the multi-potent miRNA sponge is a useful tool to examine the functional impact of simultaneous inhibition of multiple miRNAs and proposes a therapeutic potential.

  16. Functional polymorphism of the CK2alpha intronless gene plays oncogenic roles in lung cancer.

    Directory of Open Access Journals (Sweden)

    Ming-Szu Hung

    Full Text Available Protein kinase CK2 is frequently up-regulated in human cancers, although the mechanism of CK2 activation in cancer remains unknown. In this study, we investigated the role of the CK2alpha intronless gene (CSNK2A1P, a presumed CK2alpha pseudogene in the pathogenesis of human cancers. We found evidence of amplification and over-expression of the CSNK2A1P gene in non-small cell lung cancer and leukemia cell lines and 25% of the lung cancer tissues studied. The mRNA expression levels correlated with the copy numbers of the CSNK2A1P gene. We also identified a novel polymorphic variant (398T/C, I133T of the CSNK2A1P gene and showed that the 398T allele is selectively amplified over the 398C allele in 101 non-small cell lung cancer tissue samples compared to those in 48 normal controls (p = 0.013<0.05. We show for the first time CSNK2A1P protein expression in transfected human embryonic kidney 293T and mouse embryonic fibroblast NIH-3T3 cell lines. Both alleles are transforming in these cell lines, and the 398T allele appears to be more transforming than the 398C allele. Moreover, the 398T allele degrades PML tumor suppressor protein more efficiently than the 398C allele and shows a relatively stronger binding to PML. Knockdown of the CSNK2A1P gene expression with specific siRNA increased the PML protein level in lung cancer cells. We report, for the first time, that the CSNK2A1P gene is a functional proto-oncogene in human cancers and its functional polymorphism appears to degrade PML differentially in cancer cells. These results are consistent with an important role for the 398T allele of the CSNK2A1P in human lung cancer susceptibility.

  17. Inhibitor of CDK interacting with cyclin A1 (INCA1) regulates proliferation and is repressed by oncogenic signaling

    DEFF Research Database (Denmark)

    Baumer, Nicole; Tickenbrock, Lara; Tschanter, Petra

    2011-01-01

    The cell cycle is driven by the kinase activity of cyclin/CDK complexes which is negatively regulated by CDK inhibitor proteins. Recently, we identified INCA1 as interaction partner and substrate of cyclin A1 in complex with CDK2. On a functional level, we identified a novel cyclin binding site...... in the INCA1 protein. INCA1 inhibited CDK2 activity and cell proliferation. The inihibitory effects depended on the cyclin-interacting domain. Mitogenic and oncogenic signals suppressed INCA1 expression, while it was induced by cell cycle arrest. We established a deletional mouse model that showed increased...... CDK2 activity in spleen with altered spleen architecture in Inca1-/- mice. Inca1-/- embryonic fibroblasts showed an increase in the fraction of S-phase cells. Furthermore, blasts from ALL and AML patients expressed significantly reduced INCA1 levels highlighting its relevance for growth control...

  18. Analysis of tumor progression by transcriptional profiling of mouse MK16 cell lines transformed with human papillomavirus type 16 E6 and E7 oncogenes and activated H-ras.

    Science.gov (United States)

    Smahel, Michal; Smahelová, Jana; Tejklová, Pavla; Tachezy, Ruth; Jelínek, Frantisek

    2005-12-01

    A better understanding of the molecular basis of tumor progression and invasion is needed to improve therapy for malignant tumors. Recently, we established a mouse metastatic MK16 model by transduction of secondary kidney cells with human papillomavirus type 16 (HPV16) E6 and E7 oncogenes and human H-ras activated by G12V mutation. In this study, we extended the model to MK16 cell lines derived from lung metastases and compared the oncogenicity of seven cell lines successively isolated from primary tumors or metastases. By observing the formation and growth of subcutaneous tumors and generation of lung metastasis, we showed a gradual increase in oncogenicity of MK16 cell lines. Interestingly, we demonstrated metastatic potential of MK16/A cells with low oncogenic potential in primary tumor development. To detect changes in gene expression associated with increasing oncogenicity of MK16 cell lines, we performed transcriptional profiling with the Atlas Plastic Mouse 5K microarray. We found that a substantial proportion of up-regulated genes encoded ribosomal proteins. Among the down-regulated genes, the highest number (n=10) belonged to a group coding for transcription factors. Expression of two of these, Pou3f2 and Gtl3, was reduced both in cells derived from primary tumors and those isolated from metastases. Furthermore, microarray hybridization suggested that the down-regulation of cyclin-dependent kinase inhibitors p16(Ink4a) and p57(Kip2) and up-regulation of A6 and A10 members of the S100 protein family might play a role in the increase of MK16 oncogenicity.

  19. Functional transition of Pak proto-oncogene during early evolution of metazoans.

    Science.gov (United States)

    Watari, A; Iwabe, N; Masuda, H; Okada, M

    2010-07-01

    Proto-oncogenes encode signaling molecular switches regulating cellular homeostasis in metazoans, and can be converted to oncogenes by gain-of-function mutations. To address the molecular basis for development of the regulatory system of proto-oncogenes during evolution, we screened for ancestral proto-oncogenes from the unicellular choanoflagellate Monosiga ovata by monitoring their transforming activities, and isolated a Pak gene ortholog encoding a serine/threonine kinase as a 'primitive oncogene'. We also cloned Pak orthologs from fungi and the multicellular sponge Ephydatia fluviatilis, and compared their regulatory features with that of M. ovata Pak (MoPak). MoPak is constitutively active and induces cell transformation in mammalian fibroblasts, although the Pak orthologs from multicellular animals are strictly regulated. Analyses of Pak mutants revealed that structural alteration of the auto-inhibitory domain (AID) of MoPak confers higher constitutive kinase activity, as well as greater binding ability to Rho family GTPases than the multicellular Paks, and this structural alteration is responsible for cell transformation and disruption of multicellular tissue organization. These results show that maturation of AID function was required for the development of the strict regulatory system of the Pak proto-oncogene, and suggest a potential link between the establishment of the regulatory system of proto-oncogenes and metazoan evolution.

  20. Identification of a provirally activated c-Ha-ras oncogene in an avian nephroblastoma via a novel procedure: cDNA cloning of a chimaeric viral-host transcript.

    Science.gov (United States)

    Westaway, D; Papkoff, J; Moscovici, C; Varmus, H E

    1986-01-01

    Retrovirus without oncogenes often exert their neoplastic potential as insertional mutagens of cellular proto-oncogenes. This may be associated with the production of chimaeric viral-host transcripts; in these cases; activated cellular genes can be identified by obtaining cDNA clones of bipartite RNAs. This approach was used in the analysis of chicken nephroblastomas induced by myeloblastosis-associated virus (MAV). One tumor contained a novel mRNA species initiated within a MAV LTR. cDNA cloning revealed that this mRNA encodes a protein of 189 amino acids, identical to that of normal human Ha-ras-1 at 185 positions, including positions implicated in oncogenic activation of ras proto-oncogenes; there are no differences between the coding sequences of presumably normal Ha-ras cDNA clones from chicken lymphoma RNA and the tumor-derived cDNAs. The chimaeric mRNA in the nephroblastoma is at least 25-fold more abundant than c-Ha-ras mRNA in normal kidney tissue, and a 21-kd ras-related protein is present in relatively large amounts in the tumor. We conclude that a quantitative change in c-Ha-ras gene expression results from an upstream insertion mutation and presumably contributes to tumorigenesis in this single case. Little or no increase in c-Ha-ras RNA or protein was observed in other nephroblastomas. Images Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 10. PMID:3011401

  1. Comparative sequence analysis of a highly oncogenic but horizontal spread-defective clone of Marek's disease virus.

    Science.gov (United States)

    Spatz, Stephen J; Zhao, Yuguang; Petherbridge, Lawrence; Smith, Lorraine P; Baigent, Susan J; Nair, Venugopal

    2007-12-01

    Marek's disease virus (MDV) is a cell-associated alphaherpesvirus that induces rapid-onset T-cell lymphomas in poultry. MDV isolates vary greatly in pathogenicity. While some of the strains such as CVI988 are non-pathogenic and are used as vaccines, others such as RB-1B are highly oncogenic. Molecular determinants associated with differences in pathogenicity are not completely understood. Comparison of the genome sequences of phenotypically different strains could help to identify molecular determinants of pathogenicity. We have previously reported the construction of bacterial artificial chromosome (BAC) clones of RB-1B from which fully infectious viruses could be reconstituted upon DNA transfection into chicken cells. MDV reconstituted from one of these clones (pRB-1B-5) showed similar in vitro and in vivo replication kinetics and oncogenicity as the parental virus. However, unlike the parental RB-1B virus, the BAC-derived virus showed inability to spread between birds. In order to identify the unique determinants for oncogenicity and the ''non-spreading phenotype'' of MDV derived from this clone, we determined the full-length sequence of pRB-1B-5. Comparative sequence analysis with the published sequences of strains such as Md5, Md11, and CVI988 identified frameshift mutations in RLORF1, protein kinase (UL13), and glycoproteins C (UL44) and D (US6). Comparison of the sequences of these genes with the parental virus indicated that the RLORF1, UL44, and US6 mutations were also present in the parental RB-1B stock of the virus. However with regard to UL13 mutation, the parental RB-1B stock appeared to be a mixture of wild type and mutant viruses, indicating that the BAC cloning has selected a mutant clone. Although further studies are needed to evaluate the role of these genes in the horizontal-spreading defective phenotype, our data clearly indicate that mutations in these genes do not affect the oncogenicity of MDV.

  2. Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanism in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Song-Ze, E-mail: dingsongze@hotmail.com [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Yang, Yu-Xiu; Li, Xiu-Ling [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Michelli-Rivera, Audrey [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); Han, Shuang-Yin [Department of Internal Medicine, Henan Provincial People’s Hospital, Zhengzhou University, Wei-Wu Road, Zhengzhou, Henan 450000 (China); Wang, Lei; Pratheeshkumar, Poyil; Wang, Xin; Lu, Jian; Yin, Yuan-Qin; Budhraja, Amit; Hitron, Andrew J. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States)

    2013-05-15

    Hexavalent chromium [Cr(VI)] is an important human carcinogen associated with pulmonary diseases and lung cancer. Exposure to Cr(VI) induces DNA damage, cell morphological change and malignant transformation in human lung epithelial cells. Despite extensive studies, the molecular mechanisms remain elusive, it is also not known if Cr(VI)-induced transformation might accompany with invasive properties to facilitate metastasis. We aimed to study Cr(VI)-induced epithelial–mesenchymal transition (EMT) and invasion during oncogenic transformation in lung epithelial cells. The results showed that Cr(VI) at low doses represses E-cadherin mRNA and protein expression, enhances mesenchymal marker vimentin expression and transforms the epithelial cell into fibroblastoid morphology. Cr(VI) also increases cell invasion and promotes colony formation. Further studies indicated that Cr(VI) uses multiple mechanisms to repress E-cadherin expression, including activation of E-cadherin repressors such as Slug, ZEB1, KLF8 and enhancement the binding of HDAC1 in E-cadherin gene promoter, but DNA methylation is not responsible for the loss of E-cadherin. Catalase reduces Cr(VI)-induced E-cadherin and vimentin protein expression, attenuates cell invasion in matrigel and colony formation on soft agar. These results demonstrate that exposure to a common human carcinogen, Cr(VI), induces EMT and invasion during oncogenic transformation in lung epithelial cells and implicate in cancer metastasis and prevention. - Graphical abstract: Epithelial–mesenchymal transition during oncogenic transformation induced by hexavalent chromium involves reactive oxygen species-dependent mechanisms in lung epithelial cells. - Highlights: • We study if Cr(VI) might induce EMT and invasion in epithelial cells. • Cr(VI) induces EMT by altering E-cadherin and vimentin expression. • It also increases cell invasion and promotes oncogenic transformation. • Catalase reduces Cr(VI)-induced EMT, invasion and

  3. AKT activation drives the nuclear localization of CSE1L and a pro-oncogenic transcriptional activation in ovarian cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzato, Annalisa; Biolatti, Marta [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Institute for Cancer Research at Candiolo, Candiolo, Torino (Italy); Delogu, Giuseppe [Department of Biomedical Sciences-Histology, University of Sassari, Sassari (Italy); Capobianco, Giampiero [Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Sassari (Italy); Farace, Cristiano [Department of Biomedical Sciences-Histology, University of Sassari, Sassari (Italy); Dessole, Salvatore; Cossu, Antonio; Tanda, Francesco [Department of Surgical, Microsurgical and Medical Sciences, University of Sassari, Sassari (Italy); Madeddu, Roberto [Department of Biomedical Sciences-Histology, University of Sassari, Sassari (Italy); National Institute of Biostructures and Biosystems, Rome (Italy); Olivero, Martina [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Institute for Cancer Research at Candiolo, Candiolo, Torino (Italy); Di Renzo, Maria Flavia, E-mail: mariaflavia.direnzo@unito.it [Department of Oncology, University of Torino School of Medicine, Torino (Italy); Institute for Cancer Research at Candiolo, Candiolo, Torino (Italy)

    2013-10-15

    The human homolog of the yeast cse1 gene (CSE1L) is over-expressed in ovarian cancer. CSE1L forms complex with Ran and importin-α and has roles in nucleocytoplasmic traffic and gene expression. CSE1L accumulated in the nucleus of ovarian cancer cell lines, while it was localized also in the cytoplasm of other cancer cell lines. Nuclear localization depended on AKT, which was constitutively active in ovarian cancer cells, as the CSE1L protein translocated to the cytoplasm when AKT was inactivated. Moreover, the expression of a constitutively active AKT forced the translocation of CSE1L from the cytoplasm to the nucleus in other cancer cells. Nuclear accrual of CSE1L was associated to the nuclear accumulation of the phosphorylated Ran Binding protein 3 (RanBP3), which depended on AKT as well. Also in samples of human ovarian cancer, AKT activation was associated to nuclear accumulation of CSE1L and phosphorylation of RanBP3. Expression profiling of ovarian cancer cells after CSE1L silencing showed that CSE1L was required for the expression of genes promoting invasion and metastasis. In agreement, CSE1L silencing impaired motility and invasiveness of ovarian cancer cells. Altogether these data show that in ovarian cancer cells activated AKT by affecting RanBP3 phosphorylation determines the nuclear accumulation of CSE1L and likely the nuclear concentration of transcription factors conveying pro-oncogenic signals. - highlights: • CSE1L is a key player in nucleocytoplasmic traffic by forming complex with Ran. • AKT phosphorylates RanBP3 that regulates the nucleocytoplasmic gradient of Ran. • The activated oncogenic AKT drives the nuclear accumulation of CSE1L. • CSE1L in the nucleus up-regulates genes conveying pro-oncogenic signals. • CSE1L might contribute to tumor progression driven by the activated oncogenic AKT.

  4. HPV positive neuroendocrine cervical cancer cells are dependent on Myc but not E6/E7 viral oncogenes

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    Yuan, Hang; Krawczyk, Ewa; Blancato, Jan; Albanese, Christopher; Zhou, Dan; Wang, Naidong; Paul, Siddartha; Alkhilaiwi, Faris; Palechor-Ceron, Nancy; Dakic, Aleksandra; Fang, Shuang; Choudhary, Sujata; Hou, Tung-Wei; Zheng, Yun-Ling; Haddad, Bassem R.; Usuda, Yukari; Hartmann, Dan; Symer, David; Gillison, Maura; Agarwal, Seema; Wangsa, Danny; Ried, Thomas; Liu, Xuefeng; Schlegel, Richard

    2017-01-01

    Using conditional cell reprogramming, we generated a stable cell culture of an extremely rare and aggressive neuroendocrine cervical cancer. The cultured cells contained HPV-16, formed colonies in soft agar and rapidly produced tumors in immunodeficient mice. The HPV-16 genome was integrated adjacent to the Myc gene, both of which were amplified 40-fold. Analysis of RNA transcripts detected fusion of the HPV/Myc genes, arising from apparent microhomologous recombination. Spectral karyotyping (SKY) and fluorescent-in-situ hybridization (FISH) demonstrated coordinate localization and translocation of the amplified Myc and HPV genes on chromosomes 8 and 21. Similar to the primary tumor, tumor cell cultures expressed very high levels of the Myc protein and, in contrast to all other HPV-positive cervical cancer cell lines, they harbored a gain-of-function mutation in p53 (R273C). Unexpectedly, viral oncogene knockdown had no effect on the growth of the cells, but it did inhibit the proliferation of a conventional HPV-16 positive cervical cancer cell line. Knockdown of Myc, but not the mutant p53, significantly inhibited tumor cell proliferation. On the basis of these data, we propose that the primary driver of transformation in this aggressive cervical cancer is not HPV oncogene expression but rather the overexpression of Myc. PMID:28378747

  5. MicroRNA-320a acts as a tumor suppressor by targeting BCR/ABL oncogene in chronic myeloid leukemia.

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    Xishan, Zhu; Ziying, Lin; Jing, Du; Gang, Liu

    2015-01-01

    Accumulating evidences demonstrated that the induction of epithelial-mesenchymal transition (EMT) and aberrant expression of microRNAs (miRNAs) are associated with tumorigenesis, tumor progression, metastasis and relapse in cancers, including chronic myeloid leukemia (CML). We found that miR-320a expression was reduced in K562 and in CML cancer stem cells. Moreover, we found that miR-320a inhibited K562 cell migration, invasion, proliferation and promoted apoptosis by targeting BCR/ABL oncogene. As an upstream regulator of BCR/ABL, miR-320a directly targets BCR/ABL. The enhanced expression of miR-320a inhibited the phosphorylation of PI3K, AKT and NF-κB; however, the expression of phosphorylated PI3K, AKT and NF-κB were restored by the overexpression of BCR/ABL. In K562, infected with miR-320a or transfected with SiBCR/ABL, the protein levels of fibronectin, vimentin, and N-cadherin were decreased, but the expression of E-cadherin was increased. The expression of mesenchymal markers in miR-320a-expressing cells was restored to normal levels by the restoration of BCR/ABL expression. Generally speaking, miR-320a acts as a novel tumor suppressor gene in CML and miR-320a can decrease migratory, invasive, proliferative and apoptotic behaviors, as well as CML EMT, by attenuating the expression of BCR/ABL oncogene.

  6. HPV positive neuroendocrine cervical cancer cells are dependent on Myc but not E6/E7 viral oncogenes.

    Science.gov (United States)

    Yuan, Hang; Krawczyk, Ewa; Blancato, Jan; Albanese, Christopher; Zhou, Dan; Wang, Naidong; Paul, Siddartha; Alkhilaiwi, Faris; Palechor-Ceron, Nancy; Dakic, Aleksandra; Fang, Shuang; Choudhary, Sujata; Hou, Tung-Wei; Zheng, Yun-Ling; Haddad, Bassem R; Usuda, Yukari; Hartmann, Dan; Symer, David; Gillison, Maura; Agarwal, Seema; Wangsa, Danny; Ried, Thomas; Liu, Xuefeng; Schlegel, Richard

    2017-04-05

    Using conditional cell reprogramming, we generated a stable cell culture of an extremely rare and aggressive neuroendocrine cervical cancer. The cultured cells contained HPV-16, formed colonies in soft agar and rapidly produced tumors in immunodeficient mice. The HPV-16 genome was integrated adjacent to the Myc gene, both of which were amplified 40-fold. Analysis of RNA transcripts detected fusion of the HPV/Myc genes, arising from apparent microhomologous recombination. Spectral karyotyping (SKY) and fluorescent-in-situ hybridization (FISH) demonstrated coordinate localization and translocation of the amplified Myc and HPV genes on chromosomes 8 and 21. Similar to the primary tumor, tumor cell cultures expressed very high levels of the Myc protein and, in contrast to all other HPV-positive cervical cancer cell lines, they harbored a gain-of-function mutation in p53 (R273C). Unexpectedly, viral oncogene knockdown had no effect on the growth of the cells, but it did inhibit the proliferation of a conventional HPV-16 positive cervical cancer cell line. Knockdown of Myc, but not the mutant p53, significantly inhibited tumor cell proliferation. On the basis of these data, we propose that the primary driver of transformation in this aggressive cervical cancer is not HPV oncogene expression but rather the overexpression of Myc.

  7. BamHI-A rightward frame 1, an Epstein-Barr virus-encoded oncogene and immune modulator.

    Science.gov (United States)

    Hoebe, Eveline K; Le Large, Tessa Y S; Greijer, Astrid E; Middeldorp, Jaap M

    2013-11-01

    Epstein-Barr virus (EBV) causes several benign and malignant disorders of lymphoid and epithelial origin. EBV-related tumors display distinct patterns of viral latent gene expression, of which the BamHI-A rightward frame 1 (BARF1) is selectively expressed in carcinomas, regulated by cellular differentiation factors including ΔNp63α. BARF1 functions as a viral oncogene, immortalizing and transforming epithelial cells of different origin by acting as a mitogenic growth factor, inducing cyclin-D expression, and up-regulating antiapoptotic Bcl-2, stimulating host cell growth and survival. In addition, secreted hexameric BARF1 has immune evasive properties, functionally corrupting macrophage colony stimulating factor, as supported by recent functional and structural data. Therefore, BARF1, an intracellular and secreted protein, not only has multiple pathogenic functions but also can function as a target for immune responses. Deciphering the role of BARF1 in EBV biology will contribute to novel diagnostic and treatment options for EBV-driven carcinomas. Herein, we discuss recent insights on the regulation of BARF1 expression and aspects of structure-function relating to its oncogenic and immune suppressive properties.

  8. EBV finds a polycomb-mediated, epigenetic solution to the problem of oncogenic stress responses triggered by infection

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    Martin John Allday

    2013-10-01

    Full Text Available Viruses that establish a persistent infection, involving intracellular latency, commonly stimulate cellular DNA synthesis and sometimes cell division early after infection. However, most cells of metazoans have evolved ‘fail-safe’ responses that normally monitor unscheduled DNA synthesis and prevent cell proliferation when, for instance, cell proto-oncogenes are ‘activated’ by mutation, amplification or chromosomal rearrangements. These cell intrinsic defense mechanisms that reduce the risk of neoplasia and cancer are collectively called oncogenic stress responses (OSR. Mechanisms include the activation of tumor suppressor genes and the so-called DNA damage response (DDR that together trigger pathways leading to cell cycle arrest (eg cell senescence or complete elimination of cells (eg apoptosis. It is not surprising that viruses that can induce cellular DNA synthesis and cell division have the capacity to trigger OSR, nor is it surprising that these viruses have evolved countermeasures for inactivating or bypassing OSR. The main focus of this review is how the human tumour-associated Epstein-Barr virus (EBV manipulates the host polycomb group (PcG protein system to control – by epigenetic repression of transcription – key components of the OSR during the transformation of normal human B cells into permanent cell lines.

  9. Methylation status of c-fms oncogene in HCC and its relationship with clinical pathology

    Institute of Scientific and Technical Information of China (English)

    Jun Cui; Dong Hua Yang; Xiang Jun Bi; Zi Rong Fan

    2001-01-01

    @@ INTRODUCTIONThe mechanism that DNA hypomethylation leads toactivation of oncogene and occurrence of malignantneoplasm is being increasingly recognized byresearchers. Normal DNA methylation playsimportant role in stabilizing the phenotype of cell.DNA methylation status reduction and/or patternalteration are related to activation and abnormallyhigh expression of some oncogenes and cellularmalignancy[1-6]. c-fms oncogene encodes for colonystimulating factor 1 receptor (CSF-1R)[7], c-fms/CSF-1R was highly expressed in hepatocellularcarcinoma (HCC) tissue, but the mechanismremained obscure[8,9].

  10. Activating mutation in MET oncogene in familial colorectal cancer

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    Schildkraut Joellen M

    2011-10-01

    Full Text Available Abstract Background In developed countries, the lifetime risk of developing colorectal cancer (CRC is 5%, and it is the second leading cause of death from cancer. The presence of family history is a well established risk factor with 25-35% of CRCs attributable to inherited and/or familial factors. The highly penetrant inherited colon cancer syndromes account for approximately 5%, leaving greater than 20% without clear genetic definition. Familial colorectal cancer has been linked to chromosome 7q31 by multiple affected relative pair studies. The MET proto-oncogene which resides in this chromosomal region is considered a candidate for genetic susceptibility. Methods MET exons were amplified by PCR from germline DNA of 148 affected sibling pairs with colorectal cancer. Amplicons with altered sequence were detected with high-resolution melt-curve analysis using a LightScanner (Idaho Technologies. Samples demonstrating alternative melt curves were sequenced. A TaqMan assay for the specific c.2975C >T change was used to confirm this mutation in a cohort of 299 colorectal cancer cases and to look for allelic amplification in tumors. Results Here we report a germline non-synonymous change in the MET proto-oncogene at amino acid position T992I (also reported as MET p.T1010I in 5.2% of a cohort of sibling pairs affected with CRC. This genetic variant was then confirmed in a second cohort of individuals diagnosed with CRC and having a first degree relative with CRC at prevalence of 4.1%. This mutation has been reported in cancer cells of multiple origins, including 2.5% of colon cancers, and in Conclusions Although the MET p.T992I genetic mutation is commonly found in somatic colorectal cancer tissues, this is the first report also implicating this MET genetic mutation as a germline inherited risk factor for familial colorectal cancer. Future studies on the cancer risks associated with this mutation and the prevalence in different at-risk populations will

  11. Oncogenic kinase NPM/ALK induces expression of HIF1α mRNA.

    Science.gov (United States)

    Marzec, M; Liu, X; Wong, W; Yang, Y; Pasha, T; Kantekure, K; Zhang, P; Woetmann, A; Cheng, M; Odum, N; Wasik, M A

    2011-03-17

    The mechanisms of malignant cell transformation mediated by the oncogenic anaplastic lymphoma kinase (ALK) tyrosine kinase remain only partially understood. In this study, we report that T-cell lymphoma (TCL) cells carrying the nucleophosmin (NPM)/ALK fusion protein (ALK+ TCL) strongly express hypoxia-induced factor 1α (HIF1α) mRNA, even under normoxic conditions, and markedly upregulate HIF1α protein expression under hypoxia. HIF1α expression is strictly dependent on the expression and enzymatic activity of NPM/ALK, as shown in BaF3 cells transfected with wild-type NPM/ALK and kinase-inactive NPM/ALK K210R mutant and by the inhibition of the NPM/ALK function in ALK+ TCL cells by a small-molecule ALK inhibitor. NPM/ALK induces HIF1α expression by upregulating its gene transcription through its key signal transmitter signal transducer and activator of transcription 3 (STAT3), which binds to the HIF1α gene promoter as shown by the chromatin immunoprecipitation assay and is required for HIF1α gene expression as demonstrated by its small interfering RNA-mediated depletion. In turn, depletion of HIF1α increases mammalian target of rapamycin complex 1 activation, cell growth and proliferation and decreases vascular endothelial growth factor synthesis. These results identify a novel cell-transforming property of NPM/ALK, namely its ability to induce the expression of HIF1α, a protein with an important role in carcinogenesis. These results also provide another rationale to therapeutically target NPM/ALK and STAT3 in ALK+ TCL.

  12. Oncogenic features of PHF8 histone demethylase in esophageal squamous cell carcinoma.

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    Xiujing Sun

    Full Text Available Esophageal cancer is the sixth leading cause of cancer-related deaths worldwide. It has been reported that histone demethylases are involved in the carcinogenesis of certain types of tumors. Here, we studied the role of one of the histone lysine demethylases, plant homeodomain finger protein 8 (PHF8, in the carcinogenesis of esophageal squamous cell carcinoma (ESCC. Using short hairpin RNA via lentiviral infection, we established stable ESCC cell lines with constitutive downregulation of PHF8 expression. Knockdown of PHF8 in ESCC cells resulted in inhibition of cell proliferation and an increase of apoptosis. Moreover, there were reductions of both anchorage-dependent and -independent colony formation. In vitro migration and invasion assays showed that knockdown of PHF8 led to a reduction in the number of migratory and invasive cells. Furthermore, downregulation of PHF8 attenuated the tumorigenicity of ESCC cells in vivo. Taken together, our study revealed the oncogenic features of PHF8 in ESCC, suggesting that PHF8 may be a potential diagnostic marker and therapeutic target for ESCC.

  13. The impact of age on oncogenic potential: tumor-initiating cells and the brain microenvironment.

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    Stoll, Elizabeth A; Horner, Philip J; Rostomily, Robert C

    2013-10-01

    Paradoxically, aging leads to both decreased regenerative capacity in the brain and an increased risk of tumorigenesis, particularly the most common adult-onset brain tumor, glioma. A shared factor contributing to both phenomena is thought to be age-related alterations in neural progenitor cells (NPCs), which function normally to produce new neurons and glia, but are also considered likely cells of origin for malignant glioma. Upon oncogenic transformation, cells acquire characteristics known as the hallmarks of cancer, including unlimited replication, altered responses to growth and anti-growth factors, increased capacity for angiogenesis, potential for invasion, genetic instability, apoptotic evasion, escape from immune surveillance, and an adaptive metabolic phenotype. The precise molecular pathogenesis and temporal acquisition of these malignant characteristics is largely a mystery. Recent studies characterizing NPCs during normal aging, however, have begun to elucidate mechanisms underlying the age-associated increase in their malignant potential. Aging cells are dependent upon multiple compensatory pathways to maintain cell cycle control, normal niche interactions, genetic stability, programmed cell death, and oxidative metabolism. A few multi-functional proteins act as 'critical nodes' in the coordination of these various cellular activities, although both intracellular signaling and elements within the brain environment are critical to maintaining a balance between senescence and tumorigenesis. Here, we provide an overview of recent progress in our understanding of how mechanisms underlying cellular aging inform on glioma pathogenesis and malignancy.

  14. PTPN14 interacts with and negatively regulates the oncogenic function of YAP.

    Science.gov (United States)

    Liu, X; Yang, N; Figel, S A; Wilson, K E; Morrison, C D; Gelman, I H; Zhang, J

    2013-03-07

    The Hippo signaling pathway regulates cellular proliferation and survival, thus exerting profound effects on normal cell fate and tumorigenesis. The pivotal effector of this pathway is YAP, a transcriptional co-activator amplified in mouse and human cancers where it promotes epithelial-to-mesenchymal transition and malignant transformation. Here, we report a novel regulatory mechanism for the YAP oncogenic function via direct interaction with non-receptor tyrosine phosphatase 14 (PTPN14) through the WW domain of YAP and the PPxY domain of PTPN14. We also found that YAP is a direct substrate of PTPN14. In addition, luciferase reporter assay showed that the inhibition of the YAP transcriptional co-activator function by PTPN14 is mediated through their protein interactions and may result from an increase in the inactive cytoplasmic form of YAP. Last, knockdown of PTPN14 induces the nuclear retention of YAP and increases the YAP-dependent cell migration. In summary, our results indicate a potential regulatory role of PTPN14 on YAP and demonstrate a novel mechanism in YAP regulation.

  15. Small Molecules Targeting c-Myc Oncogene: Promising Anti-Cancer Therapeutics

    Science.gov (United States)

    Chen, Bing-Jia; Wu, Yan-Ling; Tanaka, Yoshimasa; Zhang, Wen

    2014-01-01

    The nuclear transcription factor c-Myc is a member of the Myc gene family with multiple functions and located on band q24.1 of chromosome 8. The c-Myc gene is activated by chromosomal translocation, rearrangement, and amplification. Its encoded protein transduces intracellular signals to the nucleus, resulting in the regulation of cell proliferation, differentiation, and apoptosis, and has the ability to transform cells and bind chromosomal DNA. c-Myc also plays a critical role in malignant transformation. The abnormal over-expression of c-Myc is frequently observed in some tumors, including carcinomas of the breast, colon, and cervix, as well as small-cell lung cancer, osteosarcomas, glioblastomas, and myeloid leukemias, therefore making it a possible target for anticancer therapy. In this minireview, we summarize unique characteristics of c-Myc and therapeutic strategies against cancer using small molecules targeting the oncogene, and discuss the prospects in the development of agents targeting c-Myc, in particular G-quadruplexes formed in c-Myc promoter and c-Myc/Max dimerization. Such information will be of importance for the research and development of c-Myc-targeted drugs. PMID:25332683

  16. Oncogenic miR-544 is an important molecular target in gastric cancer.

    Science.gov (United States)

    Zhi, Qiaoming; Guo, Xiaobo; Guo, Lei; Zhang, Rongjuan; Jiang, Jinling; Ji, Jun; Zhang, Jianian; Zhang, Jun; Chen, Xuehua; Cai, Qu; Li, Jianfang; Liu, Bingya; Zhu, Zhenggang; Yu, Yingyan

    2013-02-01

    MicroRNAs (miRNAs) and promoter hypermethylation are vital epigenetic mechanisms for transcriptional inactivation of tumor suppressor. IRX1 is a newly identified tumor suppressor gene and hypermethylation involves the decreased expression in gastric cancer. However, the microRNA regulatory mechanism on IRX1 expression is still unclear. In this study, we report an IRX1-targeting miRNA-544, which directly targets 3'-UTR of IRX1 gene by luciferase reporter assay. miR-544 suppresses the protein expression of IRX1 gene by Western blot and immunocytochemistry. Ectopic expression of miR-544 promotes cell proliferation and cell cycle progression significantly in vitro on gastric cancer cells. The study suggests that miR-544 is an oncogenic microRNA in gastric cancer. Over expression of miR-544 contributes to the inactivation and low-expression of IRX1 in gastric cancer. These findings are helpful for clarifying the molecular mechanisms involved in gastric carcinogenesis and indicate that miR-544 is a key regulator in switching cell cycle on or off. miR-544 may be a potential molecular target in miRNA-based strategy on gastric cancer.

  17. Concurrent mutation in exons 1 and 2 of the K-ras oncogene in colorectal cancer

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    Fiorella Guadagni

    2012-01-01

    Full Text Available The K-ras gene is frequently mutated in colorectal cancer and has been associated with tumor initiation and progression; approximately 90% of the activating mutations are found in codons 12 and 13 of exon 1 and just under 5% in codon 61 located in exon 2. These mutations determine single aminoacidic substitutions in the GTPase pocket leading to a block of the GTP hydrolytic activity of the K-ras p21 protein, and therefore to its constitutive activation. Point mutations in sites of the K-ras gene, other than codons 12, 13 and 61, and other types of genetic alterations, may occur in a minority of cases, such as in the less frequent cases of double mutations in the K-ras gene. However, all mutations in this gene, even those which occur in non-canonical sites or double mutations, are relevant oncogenic alterations in colorectal cancer and may underlie K-ras pathway hyperactivation. In the present study, we report the case of a patient with colorectal cancer presenting a concurrent point mutation in exons 1 and 2 of the K-ras gene, a GGT to TGT substitution (Glycine to Cysteine at codon 12, and a GAC to AAC substitution (Aspartic Acid to Asparagine at codon 57. In addition, we found in the same patient’s sample a silent polymorphism at codon 11 (Ala11Ala of exon 1. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 729–733

  18. Concurrent mutation in exons 1 and 2 of the K-ras oncogene in colorectal cancer.

    Science.gov (United States)

    Palmirotta, Raffaele; Savonarola, Annalisa; Ludovici, Giorgia; De Marchis, Maria Laura; Covello, Renato; Ettorre, Giuseppe Maria; Ialongo, Cristiano; Guadagni, Fiorella

    2011-01-01

    The K-ras gene is frequently mutated in colorectal cancer and has been associated with tumor initiation and progression; approximately 90% of the activating mutations are found in codons 12 and 13 of exon 1 and just under 5% in codon 61 located in exon 2. These mutations determine single aminoacidic substitutions in the GTPase pocket leading to a block of the GTP hydrolytic activity of the K-ras p21 protein, and therefore to its constitutive activation. Point mutations in sites of the K-ras gene, other than codons 12, 13 and 61, and other types of genetic alterations, may occur in a minority of cases, such as in the less frequent cases of double mutations in the K-ras gene. However, all mutations in this gene, even those which occur in non-canonical sites or double mutations, are relevant oncogenic alterations in colorectal cancer and may underlie K-ras pathway hyperactivation. In the present study, we report the case of a patient with colorectal cancer presenting a concurrent point mutation in exons 1 and 2 of the K-ras gene, a GGT to TGT substitution (Glycine to Cysteine) at codon 12, and a GAC to AAC substitution (Aspartic Acid to Asparagine) at codon 57. In addition, we found in the same patient's sample a silent polymorphism at codon 11 (Ala11Ala) of exon 1.

  19. HOTTIP and HOXA13 are oncogenes associated with gastric cancer progression.

    Science.gov (United States)

    Chang, Shuai; Liu, Junsong; Guo, Shaochun; He, Shicai; Qiu, Guanglin; Lu, Jing; Wang, Jin; Fan, Lin; Zhao, Wei; Che, Xiangming

    2016-06-01

    A long non-coding RNA named HOTTIP (HOXA transcript at the distal tip) coordinates the activation of various 5' HOXA genes which encode master regulators of development through targeting the WDR5/MLL complex. HOTTIP acts as an oncogene in several types of cancers, whereas its biological function in gastric cancer has never been studied. In the present study, we investigated the role of HOTTIP in gastric cancer. We found that HOTTIP was upregulated in gastric cancer cell lines. Knockdown of HOTTIP in gastric cancer cells inhibited cell proliferation, migration and invasion. Moreover, downregulation of HOTTIP led to decreased expression of homeobox protein Hox-A13 (HOXA13) in gastric cancer cell lines. HOXA13 was involved in HOTTIP‑induced malignant phenotypes of gastric cancer cells. Our data showed that the levels of HOTTIP and HOXA13 were both markedly upregulated in gastric cancer tissues compared with their counterparts in non-tumorous tissues. Furthermore, the expression levels of HOTTIP and HOXA13 were both higher in gastric cancer which was poorly differentiated, at advanced TNM stages and exhibited lymph node-metastasis. Spearman analyses indicated that HOTTIP and HOXA13 had a highly positive correlation both in non-tumor mucosae and cancer lesions. Collectively, these findings suggest that HOTTIP and HOXA13 play important roles in gastric cancer progression and provide a new insight into therapeutic treatment for the disease.

  20. Identification of TDP-43 as an oncogene in melanoma and its function during melanoma pathogenesis.

    Science.gov (United States)

    Zeng, Qinghai; Cao, Ke; Liu, Rui; Huang, Jinhua; Xia, Kun; Tang, Jintian; Chen, Xiang; Zhou, Ming; Xie, Huiqing; Zhou, Jianda

    2017-01-02

    Although recent studies have revealed TAR (trans-activating response region) DNA binding protein (TDP-43) as a potential therapeutic target for cancers, its role and clinical association with melanoma have not been explored. To identify the role and function of TDP-43 during melanoma pathogenesis. Firstly, the relationship between TDP-43 expression and patient survival was explored. Then TDP-43 expression level in melanoma tissue and different melanoma cell lines was measured. After silencing TDP-43 expression in melanoma cells, the impacts of TDP-43 on cellular proliferation, metastasis, glucose uptake, and glucose transporters levels were studied. In the end, effect of TDP-43 depletion on tumorigenicity of melanoma cells was tested in vivo. Our results showed that TDP-43 was overexpressed in melanoma paraffin samples compared with that in nevi tissues. The high expression level of TDP-43 was associated with poor patient survival. By silencing TDP-43, we saw significant inhibition of cell proliferation and metastasis in A375 and WM451 cells. TDP-43 knockdown could suppress glucose transporter type-4 (GLUT4) expression and reduce glucose uptake. And downregulation of GLUT4 in melanoma cells induced inhibition of cell proliferation and metastasis. TDP-43 knockdown significantly slowed down tumor growth and decreased GLUT4 expression in vivo. TDP-43 is a novel oncogene in melanoma and regulates melanoma proliferation and metastasis potentially through modulation of glucose metabolism.

  1. Long noncoding RNA linc00617 exhibits oncogenic activity in breast cancer.

    Science.gov (United States)

    Li, Hengyu; Zhu, Li; Xu, Lu; Qin, Keyu; Liu, Chaoqian; Yu, Yue; Su, Dongwei; Wu, Kainan; Sheng, Yuan

    2017-01-01

    Protein-coding genes account for only 2% of the human genome, whereas the vast majority of transcripts are noncoding RNAs including long noncoding RNAs. LncRNAs are involved in the regulation of a diverse array of biological processes, including cancer progression. An evolutionarily conserved lncRNA TUNA, was found to be required for pluripotency of mouse embryonic stem cells. In this study, we found the human ortholog of TUNA, linc00617, was upregulated in breast cancer samples. Linc00617 promoted motility and invasion of breast cancer cells and induced epithelial-mesenchymal-transition (EMT), which was accompanied by generation of stem cell properties. Moreover, knockdown of linc00617 repressed lung metastasis in vivo. We demonstrated that linc00617 upregulated the expression of stemness factor Sox2 in breast cancer cells, which was shown to promote the oncogenic activity of breast cancer cells by stimulating epithelial-to-mesenchymal transition and enhancing the tumor-initiating capacity. Thus, our data indicate that linc00617 functions as an important regulator of EMT and promotes breast cancer progression and metastasis via activating the transcription of Sox2. Together, it suggests that linc00617 may be a potential therapeutic target for aggressive breast cancer. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  2. PP6 Disruption Synergizes with Oncogenic Ras to Promote JNK-Dependent Tumor Growth and Invasion.

    Science.gov (United States)

    Ma, Xianjue; Lu, Jin-Yu; Dong, Yongli; Li, Daming; Malagon, Juan N; Xu, Tian

    2017-06-27

    RAS genes are frequently mutated in cancers, yet an effective treatment has not been developed, partly because of an incomplete understanding of signaling within Ras-related tumors. To address this, we performed a genetic screen in Drosophila, aiming to find mutations that cooperate with oncogenic Ras (Ras(V12)) to induce tumor overgrowth and invasion. We identified fiery mountain (fmt), a regulatory subunit of the protein phosphatase 6 (PP6) complex, as a tumor suppressor that synergizes with Ras(V12) to drive c-Jun N-terminal kinase (JNK)-dependent tumor growth and invasiveness. We show that Fmt negatively regulates JNK upstream of dTAK1. We further demonstrate that disruption of PpV, the catalytic subunit of PP6, mimics fmt loss-of-function-induced tumorigenesis. Finally, Fmt synergizes with PpV to inhibit JNK-dependent tumor progression. Our data here further highlight the power of Drosophila as a model system to unravel molecular mechanisms that may be relevant to human cancer biology. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. PP6 Disruption Synergizes with Oncogenic Ras to Promote JNK-Dependent Tumor Growth and Invasion

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    Xianjue Ma

    2017-06-01

    Full Text Available RAS genes are frequently mutated in cancers, yet an effective treatment has not been developed, partly because of an incomplete understanding of signaling within Ras-related tumors. To address this, we performed a genetic screen in Drosophila, aiming to find mutations that cooperate with oncogenic Ras (RasV12 to induce tumor overgrowth and invasion. We identified fiery mountain (fmt, a regulatory subunit of the protein phosphatase 6 (PP6 complex, as a tumor suppressor that synergizes with RasV12 to drive c-Jun N-terminal kinase (JNK-dependent tumor growth and invasiveness. We show that Fmt negatively regulates JNK upstream of dTAK1. We further demonstrate that disruption of PpV, the catalytic subunit of PP6, mimics fmt loss-of-function-induced tumorigenesis. Finally, Fmt synergizes with PpV to inhibit JNK-dependent tumor progression. Our data here further highlight the power of Drosophila as a model system to unravel molecular mechanisms that may be relevant to human cancer biology.

  4. Inactivation and inducible oncogenic mutation of p53 in gene targeted pigs.

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    Simon Leuchs

    Full Text Available Mutation of the tumor suppressor p53 plays a major role in human carcinogenesis. Here we describe gene-targeted porcine mesenchymal stem cells (MSCs and live pigs carrying a latent TP53(R167H mutant allele, orthologous to oncogenic human mutant TP53(R175H and mouse Trp53(R172H, that can be activated by Cre recombination. MSCs carrying the latent TP53(R167H mutant allele were analyzed in vitro. Homozygous cells were p53 deficient, and on continued culture exhibited more rapid proliferation, anchorage independent growth, and resistance to the apoptosis-inducing chemotherapeutic drug doxorubicin, all characteristic of cellular transformation. Cre mediated recombination activated the latent TP53(R167H allele as predicted, and in homozygous cells expressed mutant p53-R167H protein at a level ten-fold greater than wild-type MSCs, consistent with the elevated levels found in human cancer cells. Gene targeted MSCs were used for nuclear transfer and fifteen viable piglets were produced carrying the latent TP53(R167H mutant allele in heterozygous form. These animals will allow study of p53 deficiency and expression of mutant p53-R167H to model human germline, or spontaneous somatic p53 mutation. This work represents the first inactivation and mutation of the gatekeeper tumor suppressor gene TP53 in a non-rodent mammal.

  5. 3-(2-Chloropropyl amide)-4-methoxy-N-phenylbenzamide inhibits expression of HPV oncogenes in human cervical cancer cell.

    Science.gov (United States)

    Han, Fang; Li, Yanping; Lu, Qiaoni; Ma, Linlin; Wang, Huiqiang; Jiang, Jiandong; Li, Zhuorong; Li, Yuhuan

    2017-07-28

    Human papillomaviruses (HPVs) are the primary causative agents for cervical cancer, and HPV oncoproteins E6 and E7 are known to be the main reason for the onset and maintenance of the malignancies. Therefore, inhibition of viral E6 and E7 oncoproteins expression represents a viable strategy to cervical cancer therapies. This study is to evaluate the antiviral effect of a novel N-Phenylbenzamide derivative, 3-(2-Chloropropyl amide)-4-methoxy-N-phenylbenzamide (L17), against HPV16 in vitro and identify its associated mechanism of action in cervical cancer cells. The cytotoxic effect of L17 was assessed by MTT assay. The mRNA and protein levels of E6 and E7 oncogenes were analyzed by quantitative real-time reverse transcription PCR (qRT-PCR) and Western blot, respectively. p53 and Rb protein levels were also detected by Western blot. The effect of L17 on cell cycle was analyzed by flow cytometry. The cytotoxic effect of L17 was greater in cervical carcinoma cells than in normal cells. L17 significantly reduced the expression of HPV16 E6 and E7 mRNA and protein, at least partly by enhancing degradation of HPV16 E6 and E7 mRNA. Moreover, reduced expression of E6 and E7 induced by L17 resulted in the up-regulation of p53 and Rb expression, which subsequently induced CaSki cells arrest at G0/G1 phase. L17 has antiviral activity through suppressing E6 and E7 oncogene expression and could inhibit CaSki cell proliferating by inducing cells arrest at G0/G1 phase at nontoxic concentration, implying that L17 might be exploited as a candidate agent for HPV-associated cervical cancer prevention and treatment.

  6. Oncogenic CARD11 mutations induce hyperactive signaling by disrupting autoinhibition by the PKC-responsive inhibitory domain.

    Science.gov (United States)

    Lamason, Rebecca L; McCully, Ryan R; Lew, Stefanie M; Pomerantz, Joel L

    2010-09-28

    The regulated activation of NF-κB by antigen receptor signaling is required for normal B and T lymphocyte activation during the adaptive immune response. Dysregulated NF-κB activation is associated with several types of lymphoma, including diffuse large B cell lymphoma (DLBCL). During normal antigen receptor signaling, the multidomain scaffold protein CARD11 undergoes a transition from a closed, inactive state to an open, active conformation that recruits several signaling proteins into a complex, leading to IKK kinase activation. This transition is regulated by the CARD11 inhibitory domain (ID), which participates in intramolecular interactions that prevent cofactor binding to CARD11 prior to signaling, but which is neutralized after receptor engagement by phosphorylation. Several oncogenic CARD11 mutations have been identified in DLBCL that enhance activity and that are mostly found in the coiled-coil domain. However, the mechanisms by which these mutations cause CARD11 hyperactivity and spontaneous NF-κB activation are poorly understood. In this report, we provide several lines of evidence that oncogenic mutations F123I and L225LI induce CARD11 hyperactivity by disrupting autoinhibition by the CARD11 ID. These mutations disrupt ID-mediated intramolecular interactions and ID-dependent inhibition and bypass the requirement for ID phosphorylation during T cell receptor signaling. Intriguingly, these mutations selectively enhance the apparent affinity of CARD11 for Bcl10, but not for other signaling proteins that are recruited to CARD11 in an ID-dependent manner during normal antigen receptor signaling. Our results establish a mechanism that explains how DLBCL-associated mutations in CARD11 can initiate spontaneous, receptor-independent activation of NF-κB.

  7. Effects of sulfur dioxide derivatives on expression of oncogenes and tumor suppressor genes in human bronchial epithelial cells.

    Science.gov (United States)

    Qin, Guohua; Meng, Ziqiang

    2009-04-01

    Sulfur dioxide (SO(2)) is a major air pollutant suspected to act as a promoter or co-carcinogen. The present study was designed to investigate whether SO(2) derivatives (bisulfite and sulfite) had effects on the expression of several proto-oncogenes and tumor suppressor genes in cultured human bronchial epithelial (BEP2D) cells. The mRNA and protein levels were measured by real-time RT-PCR and western blotting, respectively, following exposure to differing SO(2)-derivative concentrations and exposure times. SO(2) derivatives caused mRNA and protein over-expression of c-fos, c-jun, and c-myc at all tested doses (0.001-2mM). Over-expression of H-ras and p53 were observed in cells receiving the highest concentration (0.1-2mM), as well as the under-expression of p16 and Rb. The over-expression of c-fos and c-jun was observed after 24h recovery. The expression of c-myc and H-ras decreased to base line levels while the p53 expression decreased compared with control after 24h recovery. The mRNA and protein expression of p16 and Rb remained at initial levels after 24h recovery. The data support the hypothesis that SO(2) derivatives could cause the activation of proto-oncogenes and inactivation of tumor suppressor genes and SO(2) derivatives may play a role in the pathogenesis of SO(2)-associated lung cancer.

  8. Down-regulation of the oncogene PTTG1 via the KLF6 tumor suppressor during induction of myeloid differentiation.

    Directory of Open Access Journals (Sweden)

    Pei-Yi Chen

    Full Text Available The aberrant expression of proto-oncogenes is involved in processes that are responsible for cellular proliferation and the inhibition of myeloid differentiation in acute myeloid leukemia (AML. Pituitary Tumor-Transforming gene 1 (PTTG1, an oncogenic transcription factor, is abundantly expressed in various human cancers and hematopoietic malignancies. However, its expression in normal leukocytes and most normal tissues is very low or undetectable. The mechanism by which PTTG1 overexpression modifies myeloid cell development and promotes leukemogenesis remain unclear. To investigate the mechanistic links between PTTG1 overexpression and leukemia cell differentiation, we utilized phorbol 12-myristate 13-acetate (PMA, a well-known agent that triggers monocyte/macrophage differentiation, to analyze the expression patterns of PTTG1 in PMA-induced myeloid differentiation. We found that PTTG1 is down-regulated at the transcriptional level in PMA-treated HL-60 and THP1 cells. In addition, we identified a binding site for a tumor suppressor protein, Kruppel-like factor 6 (KLF6, in the PTTG1 promoter. We found that KLF6 could directly bind and repress PTTG1 expression. In HL-60 and THP1 cells, KLF6 mRNA and protein levels are up-regulated with a concordant reduction of PTTG1 expression upon treatment with PMA. Furthermore, KLF6 knockdown by shRNA abolished the suppression of PTTG1 and reduced the activation of the differentiation marker CD11b in PMA-primed cells. The protein kinase C (PKC inhibitor and the MAPK/ERK kinase (MEK inhibitor significantly blocked the potentiation of PMA-mediated KLF6 induction and the down-regulation of PTTG1, indicating that PTTG1 is suppressed via the activation of PKC/ERK/KLF6 pathway. Our findings suggest that drugs that increase the KLF6 inhibition of PTTG1 may have a therapeutic application in AML treatment strategies.

  9. FOXM1 is an oncogenic mediator in Ewing Sarcoma.

    Directory of Open Access Journals (Sweden)

    Laura Christensen

    Full Text Available Ewing Family Tumors (Ewing Sarcoma and peripheral Primitive Neuroectodermal Tumor are common bone and soft tissue malignancies of childhood, adolescence and young adulthood. Chromosomal translocation in these tumors produces fusion oncogenes of the EWS/ETS class, with EWS/FLI1 being by far the most common. EWS/ETS chimera are the only well established driver mutations in these tumors and they function as aberrant transcription factors. Understanding the downstream genes whose expression is modified has been a central approach to the study of these tumors. FOXM1 is a proliferation associated transcription factor which has increasingly been found to play a role in the pathogenesis of a wide range of human cancers. Here we demonstrate that FOXM1 is expressed in Ewing primary tumors and cell lines. Reduction in FOXM1 expression in Ewing cell lines results in diminished potential for anchorage independent growth. FOXM1 expression is enhanced by EWS/FLI1, though, unlike other tumor systems, it is not driven by expression of the EWS/FLI1 target GLI1. Thiostrepton is a compound known to inhibit FOXM1 by direct binding. We show that Thiostrepton diminishes FOXM1 expression in Ewing cell lines and this reduction reduces cell viability through an apoptotic mechanism. FOXM1 is involved in Ewing tumor pathogenesis and may prove to be a useful therapeutic target in Ewing tumors.

  10. Human Papillomavirus 16E6 Oncogene Mutation in Cervical Cancer

    Institute of Scientific and Technical Information of China (English)

    Feng Sun; Xiao-qin Ha; Tong-de Lv; Chuan-ping Xing; Bin Liu; Xiao-zhe Cao

    2009-01-01

    Objective: Cervical cancer (CC) is the second most common type of cancer in women worldwide, after breast cancer. High-risk human papillomaviruses (HR-HPVs) are considered to be the major causes of cervical cancer. HPV16 is the most common type of HR-HPVs and HPV16 E6 gene is one of the major oncogenes. Specific mutations are considered as dangerous factors causing CC. This study was designed to find mutations of HPV16 E6 and the relationship between the mutations and the happening of CC.Methods: The tissue DNA was extracted from 15 biopsies of CC. Part of HPV16 E6 gene (nucleotide 201-523) was amplified by polymerase chain reaction (PCR) from the CC tissue DNA. The PCR fragments were sequenced and analyzed.Results: The result of PCR showed that the positive rate of HPV16 E6 was 93.33% (14/15). After sequencing and analyzing, in the 13 out of 14 PCR fragments, 4 maintained prototype (30.77%), 8 had a same 350G mutation (61.54%), and 1 had a 249G mutation (7.69%).Conclusion: This study suggest that there is a high infection rate of HPV in cervical cancer and most of the HPV16 E6 gene has mutations. Those mutations may have an association with the development of cervical cancer.

  11. Re-Configuration of Sphingolipid Metabolism by Oncogenic Transformation

    Directory of Open Access Journals (Sweden)

    Anthony S. Don

    2014-03-01

    Full Text Available The sphingolipids are one of the major lipid families in eukaryotes, incorporating a diverse array of structural variants that exert a powerful influence over cell fate and physiology. Increased expression of sphingosine kinase 1 (SPHK1, which catalyses the synthesis of the pro-survival, pro-angiogenic metabolite sphingosine 1-phosphate (S1P, is well established as a hallmark of multiple cancers. Metabolic alterations that reduce levels of the pro-apoptotic lipid ceramide, particularly its glucosylation by glucosylceramide synthase (GCS, have frequently been associated with cancer drug resistance. However, the simple notion that the balance between ceramide and S1P, often referred to as the sphingolipid rheostat, dictates cell survival contrasts with recent studies showing that highly potent and selective SPHK1 inhibitors do not affect cancer cell proliferation or survival, and studies demonstrating higher ceramide levels in some metastatic cancers. Recent reports have implicated other sphingolipid metabolic enzymes such as acid sphingomyelinase (ASM more strongly in cancer pathogenesis, and highlight lysosomal sphingolipid metabolism as a possible weak point for therapeutic targeting in cancer. This review describes the evidence implicating different sphingolipid metabolic enzymes and their products in cancer pathogenesis, and suggests how newer systems-level approaches may improve our overall understanding of how oncogenic transformation reconfigures sphingolipid metabolism.

  12. The LMO2 oncogene regulates DNA replication in hematopoietic cells.

    Science.gov (United States)

    Sincennes, Marie-Claude; Humbert, Magali; Grondin, Benoît; Lisi, Véronique; Veiga, Diogo F T; Haman, André; Cazaux, Christophe; Mashtalir, Nazar; Affar, El Bachir; Verreault, Alain; Hoang, Trang

    2016-02-02

    Oncogenic transcription factors are commonly activated in acute leukemias and subvert normal gene expression networks to reprogram hematopoietic progenitors into preleukemic stem cells, as exemplified by LIM-only 2 (LMO2) in T-cell acute lymphoblastic leukemia (T-ALL). Whether or not these oncoproteins interfere with other DNA-dependent processes is largely unexplored. Here, we show that LMO2 is recruited to DNA replication origins by interaction with three essential replication enzymes: DNA polymerase delta (POLD1), DNA primase (PRIM1), and minichromosome 6 (MCM6). Furthermore, tethering LMO2 to synthetic DNA sequences is sufficient to transform these sequences into origins of replication. We next addressed the importance of LMO2 in erythroid and thymocyte development, two lineages in which cell cycle and differentiation are tightly coordinated. Lowering LMO2 levels in erythroid progenitors delays G1-S progression and arrests erythropoietin-dependent cell growth while favoring terminal differentiation. Conversely, ectopic expression in thymocytes induces DNA replication and drives these cells into cell cycle, causing differentiation blockade. Our results define a novel role for LMO2 in directly promoting DNA synthesis and G1-S progression.

  13. Gallium-68: chemistry and radiolabeled peptides exploring different oncogenic pathways.

    Science.gov (United States)

    Morgat, Clément; Hindié, Elif; Mishra, Anil K; Allard, Michèle; Fernandez, Philippe

    2013-03-01

    Abstract Early and specific tumor detection and also therapy selection and response evaluation are some challenges of personalized medicine. This calls for high sensitive and specific molecular imaging such as positron emission tomography (PET). The use of peptides for PET molecular imaging has undeniable advantages: possibility of targeting through peptide-receptor interaction, small size and low-molecular weight conferring good penetration in the tissue or at cellular level, low toxicity, no antigenicity, and possibility of wide choice for radiolabeling. Among β(+)-emitter radioelements, Gallium-68 is a very attractive positron-emitter compared with carbon-11 or fluorine-18 taking into account its easy production via a (68)Ge/(68)Ga generator and well established radiochemistry. Gallium-68 chemistry is based on well-defined coordination complexes with macrocycle or chelates having strong binding properties, particularly suitable for linking peptides that allow resistance to in vivo transchelation of the metal ion. Understanding specific and nonspecific molecular mechanisms involved in oncogenesis is one major key to develop new molecular imaging tools. The present review focuses on peptide signaling involved in different oncogenic pathways. This peptide signalization might be common for tumoral and non-tumoral processes or could be specific of an oncological process. This review describes gallium chemistry and different (68)Ga-radiolabeled peptides already in use or under development aiming at developing molecular PET imaging of different oncological processes.

  14. [Genetic tests in oncology practice with emphasis on the RET oncogene and VHL tumor suppressor gene].

    Science.gov (United States)

    Nesković, Gorana; Stanojević, Boban; Palmar, Ivan; Dimitrijević, Bogomir

    2002-07-01

    Molecular oncogenetics is the study of two distinct gene classes participating in the pathogenesis of malignant diseases: proto-oncogenes and tumour suppressors genes. Stepwise alterations in their structure are the basis of malignancy. Structural abnormalities range widely: gross genetic rearrangements including insertions, deletions, gene amplifications and single nucleotide deleotide deletions and substitutions. These gene alterations are determined by gene testing that increasingly are part of clinical diagnosis. Among many applications of oncogene testing is detection of hereditary forms of malignant disease with outstanding prophylactic and therapeutic importance. Along this line, gene testing provided for effective prevention of specific hereditary tumour types. Analysis of hereditary pheochromocytoma two gene tests are established: detection of multiple endocrine neoplasia type 2 (MEN 2) using mutational analysis of RET gene and detection of von Hippel-Lindau syndrome using mutational analysis of VHL gene. These genes were characterized about a decade ago and their structure determined in detail. Numerous studies focus on expression of these genes in different tissues and the function of respective proteins. In extensive epidemiology the following facts are established: hereditary mutations in the RET gene in > 92% of cases with MEN 2 syndrome while in patients with von Hippel-Lindau syndrome hereditary mutations were detected in VHL gene in > 95% of cases. Such a high genotype--phenotype correlation forms the basis for clinical applications. Gene testing in oncology offers numerous advantages. If a patient with pheochromocytoma presents with hereditary mutation in the RET or VHL gene, family gene testing is recommended. Family member with hereditary gene mutation is indicative of the risk level of nearly 100% for MEN 2 or von Hippel-Lindau syndrome. In such cases surgery is warranted (e.g. in MEN 2 total thyroidectomy by the age of (6). Negative findings

  15. Oncogenic and tumor-promoting Spermatophytes and Pteridophytes and their active principles.

    Science.gov (United States)

    Farnsworth, N R; Bingel, A S; Fong, H H; Saleh, A A; Christenson, G M; Saufferer, S M

    1976-08-01

    A survey and discussion are presented of plants classified as Spermatophyta and Pteridophyta, extracts of which have been shown to be oncogenic or tumor-promoting in animals. The active oncogenic and tumor-promoting principles, where known, have been identified. They represent tannins; pyrrolizidine, indole, tropolone, quinoline, purine, and benzophenanthridine alkaloids; nitroso compounds; triterpene glycosides; lignans; isoflavans; allyl benzenoids; simple (nu-pyrenes; and carbocyclic hydroxy acids. A total of 28 compounds of known structure have been identified as oncogens and several phorbol esters as tumor-promoters. Plants known to contain any of the 28 oncogens (excluding shikimic acid and caffeine) have been tabulated; they represent at least 454 species, 110 genera, and 34 families of Spermatophyta and Pteridophyta.

  16. A germline RET proto-oncogene mutation in multiple members of an ...

    African Journals Online (AJOL)

    Makia Marafie

    2016-09-17

    Sep 17, 2016 ... multiple members of an Arab family with variable onset of MEN type ... fashion and caused by germline mutation in RET proto- oncogene. The main .... ing sudden severe high blood pressure crises that required immediate ...

  17. Duplication of the MYB oncogene in T cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Lahortiga, Idoya; De Keersmaecker, Kim; Van Vlierberghe, Pieter; Graux, Carlos; Cauwelier, Barbara; Lambert, Frederic; Mentens, Nicole; Beverloo, H Berna; Pieters, Rob; Speleman, Frank; Odero, Maria D; Bauters, Marijke; Froyen, Guy; Marynen, Peter; Vandenberghe, Peter; Wlodarska, Iwona; Meijerink, Jules P P; Cools, Jan

    2007-05-01

    We identified a duplication of the MYB oncogene in 8.4% of individuals with T cell acute lymphoblastic leukemia (T-ALL) and in five T-ALL cell lines. The duplication is associated with a threefold increase in MYB expression, and knockdown of MYB expression initiates T cell differentiation. Our results identify duplication of MYB as an oncogenic event and suggest that MYB could be a therapeutic target in human T-ALL.

  18. Genetic disruption of oncogenic Kras sensitizes lung cancer cells to Fas receptor-mediated apoptosis.

    Science.gov (United States)

    Mou, Haiwei; Moore, Jill; Malonia, Sunil K; Li, Yingxiang; Ozata, Deniz M; Hough, Soren; Song, Chun-Qing; Smith, Jordan L; Fischer, Andrew; Weng, Zhiping; Green, Michael R; Xue, Wen

    2017-04-04

    Genetic lesions that activate KRAS account for ∼30% of the 1.6 million annual cases of lung cancer. Despite clinical need, KRAS is still undruggable using traditional small-molecule drugs/inhibitors. When oncogenic Kras is suppressed by RNA interference, tumors initially regress but eventually recur and proliferate despite suppression of Kras Here, we show that tumor cells can survive knockout of oncogenic Kras, indicating the existence of Kras-independent survival pathways. Thus, even if clinical KRAS inhibitors were available, resistance would remain an obstacle to treatment. Kras-independent cancer cells exhibit decreased colony formation in vitro but retain the ability to form tumors in mice. Comparing the transcriptomes of oncogenic Kras cells and Kras knockout cells, we identified 603 genes that were specifically up-regulated in Kras knockout cells, including the Fas gene, which encodes a cell surface death receptor involved in physiological regulation of apoptosis. Antibodies recognizing Fas receptor efficiently induced apoptosis of Kras knockout cells but not oncogenic Kras-expressing cells. Increased Fas expression in Kras knockout cells was attributed to decreased association of repressive epigenetic marks at the Fas promoter. Concordant with this observation, treating oncogenic Kras cells with histone deacetylase inhibitor and Fas-activating antibody efficiently induced apoptosis, thus bypassing the need to inhibit Kras. Our results suggest that activation of Fas could be exploited as an Achilles' heel in tumors initiated by oncogenic Kras.

  19. [Oncogenes RET/PTC and mechanisms of their involvement in thyroid cancerogenesis].

    Science.gov (United States)

    Voskoboĭnyk, L H

    2009-01-01

    Papillary thyroid carcinomas are the most common type of thyroid oncopathology, and are rather often associated with the expression of RET/PTC oncogens. The first oncogen RET/PTC1 was isolated more than 20 years ago. Now 13 different forms of RET/PTC are known, and 12 different partner-genes are described, that could be involved in formation of RET/PTC oncogenes. The most common of them are RET/PTC1 and RET/PTC3 forms. The great majority of oncogens RET/PTC, except for two--ELKS-RET and HOOK3-RET, have been founded in radioaction-induced thyroid tumors. There is an opinion that the key role in development of papillary thyroid carcinomas belongs to RET/PTC oncogens. The data about different types of RET/PTC oncogens, factors, that lead to their formation have been described in the present review. Also different mechanisms of activation of transduction pathways and gene's expression in thyroid cells after RET/PTC induction have been presented.

  20. HuR knockdown changes the oncogenic potential of oral cancer cells.

    Science.gov (United States)

    Kakuguchi, Wataru; Kitamura, Tetsuya; Kuroshima, Takeshi; Ishikawa, Makoto; Kitagawa, Yoshimasa; Totsuka, Yasunori; Shindoh, Masanobu; Higashino, Fumihiro

    2010-04-01

    HuR binds to AU-rich element-containing mRNA to protect them from rapid degradation. Here, we show that knockdown of HuR changes the oncogenic properties of oral cancer cells. Oral squamous cell carcinoma cell lines, HSC-3 and Ca9.22, which express HuR protein and cytoplasmic AU-rich element mRNA more abundantly than normal cells, were subjected to HuR knockdown. In the HuR-knockdown cancer cells, the cytoplasmic expression of c-fos, c-myc, and COX-2 mRNAs was inhibited compared with those in cells that had been transfected with a control small interfering RNA, and the half-lives of these mRNAs were shorter than those of their counterparts in the control cells. HuR-knockdown cells failed to make colonies in soft agar, suggesting that the cells had lost their ability for anchorage-independent cell growth. Additionally, the motile and invasive activities of the cells decreased remarkably by HuR knockdown. Furthermore, the expression of cell cycle-related proteins, such as cyclin A, cyclin B1, cyclin D1, and cyclin-dependent kinase 1, was reduced in HuR-knockdown cancer cells, and HuR bound to cdk1 mRNA to stabilize it. These findings suggest that HuR knockdown changes the features of oral cancer cells, at least in part, by affecting their cell cycle and shows potential as an effective therapeutic approach.

  1. Excess of NPM-ALK oncogenic signaling promotes cellular apoptosis and drug dependency.

    Science.gov (United States)

    Ceccon, M; Merlo, M E Boggio; Mologni, L; Poggio, T; Varesio, L M; Menotti, M; Bombelli, S; Rigolio, R; Manazza, A D; Di Giacomo, F; Ambrogio, C; Giudici, G; Casati, C; Mastini, C; Compagno, M; Turner, S D; Gambacorti-Passerini, C; Chiarle, R; Voena, C

    2016-07-21

    Most of the anaplastic large-cell lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein NPM-ALK (nucleophosmin-anaplastic lymphoma kinase). NPM-ALK-deregulated kinase activity drives several pathways that support malignant transformation of lymphoma cells. We found that in ALK-rearranged ALCL cell lines, NPM-ALK was distributed in equal amounts between the cytoplasm and the nucleus. Only the cytoplasmic portion was catalytically active in both cell lines and primary ALCL, whereas the nuclear portion was inactive because of heterodimerization with NPM1. Thus, about 50% of the NPM-ALK is not active and sequestered as NPM-ALK/NPM1 heterodimers in the nucleus. Overexpression or relocalization of NPM-ALK to the cytoplasm by NPM genetic knockout or knockdown caused ERK1/2 (extracellular signal-regulated protein kinases 1 and 2) increased phosphorylation and cell death through the engagement of an ATM/Chk2- and γH2AX (phosphorylated H2A histone family member X)-mediated DNA-damage response. Remarkably, human NPM-ALK-amplified cell lines resistant to ALK tyrosine kinase inhibitors (TKIs) underwent apoptosis upon drug withdrawal as a consequence of ERK1/2 hyperactivation. Altogether, these findings indicate that an excess of NPM-ALK activation and signaling induces apoptosis via oncogenic stress responses. A 'drug holiday' where the ALK TKI treatment is suspended could represent a therapeutic option in cells that become resistant by NPM-ALK amplification.

  2. Transformation and radiosensitivity of human diploid skin fibroblasts transfected with activated RAS oncogene and SV40 T-antigen

    Energy Technology Data Exchange (ETDEWEB)

    Su, L.-N.; Little, J.B. (Harvard School of Public Health, Boston, MA (United States))

    1992-08-01

    Three normal human diploid cell strains were transfected with an activated Ha-ras oncogene (EJ ras) or SV40 T-antigen. Multiple clones were examined for morphological alterations, growth requirements, ability to grow under anchorage independent conditions, immortality and tumorigenicity in nude mice. Clones expressing SV40 T-antigen alone or in combination with ras protein p21 were significantly radioresistant as compared with their parent cells or clones transfected with the neo gene only. This radioresistant phenotype persisted in post-crisis, immortalized cell lines. These data suggest that expression of the SV40 T-antigen but not activated Ha-ras plays an important role in the radiosensitivity of human diploid cells. The radioresistant phenotype in SV40 T transfected cells was not related to the enhanced level of genetic instability seen in pre-crisis and newly immortalized cells, nor to the process of immortalization itself. (author).

  3. Negative Selection and Chromosome Instability Induced by Mad2 Overexpression Delay Breast Cancer but Facilitate Oncogene-Independent Outgrowth

    Directory of Open Access Journals (Sweden)

    Konstantina Rowald

    2016-06-01

    Full Text Available Chromosome instability (CIN is associated with poor survival and therapeutic outcome in a number of malignancies. Despite this correlation, CIN can also lead to growth disadvantages. Here, we show that simultaneous overexpression of the mitotic checkpoint protein Mad2 with KrasG12D or Her2 in mammary glands of adult mice results in mitotic checkpoint overactivation and a delay in tumor onset. Time-lapse imaging of organotypic cultures and pathologic analysis prior to tumor establishment reveals error-prone mitosis, mitotic arrest, and cell death. Nonetheless, Mad2 expression persists and increases karyotype complexity in Kras tumors. Faced with the selective pressure of oncogene withdrawal, Mad2-positive tumors have a higher frequency of developing persistent subclones that avoid remission and continue to grow.

  4. Negative Selection and Chromosome Instability Induced by Mad2 Overexpression Delay Breast Cancer but Facilitate Oncogene-Independent Outgrowth.

    Science.gov (United States)

    Rowald, Konstantina; Mantovan, Martina; Passos, Joana; Buccitelli, Christopher; Mardin, Balca R; Korbel, Jan O; Jechlinger, Martin; Sotillo, Rocio

    2016-06-21

    Chromosome instability (CIN) is associated with poor survival and therapeutic outcome in a number of malignancies. Despite this correlation, CIN can also lead to growth disadvantages. Here, we show that simultaneous overexpression of the mitotic checkpoint protein Mad2 with Kras(G12D) or Her2 in mammary glands of adult mice results in mitotic checkpoint overactivation and a delay in tumor onset. Time-lapse imaging of organotypic cultures and pathologic analysis prior to tumor establishment reveals error-prone mitosis, mitotic arrest, and cell death. Nonetheless, Mad2 expression persists and increases karyotype complexity in Kras tumors. Faced with the selective pressure of oncogene withdrawal, Mad2-positive tumors have a higher frequency of developing persistent subclones that avoid remission and continue to grow.

  5. Evolution in an oncogenic bacterial species with extreme genome plasticity: Helicobacter pylori East Asian genomes

    Directory of Open Access Journals (Sweden)

    Handa Naofumi

    2011-05-01

    Full Text Available Abstract Background The genome of Helicobacter pylori, an oncogenic bacterium in the human stomach, rapidly evolves and shows wide geographical divergence. The high incidence of stomach cancer in East Asia might be related to bacterial genotype. We used newly developed comparative methods to follow the evolution of East Asian H. pylori genomes using 20 complete genome sequences from Japanese, Korean, Amerind, European, and West African strains. Results A phylogenetic tree of concatenated well-defined core genes supported divergence of the East Asian lineage (hspEAsia; Japanese and Korean from the European lineage ancestor, and then from the Amerind lineage ancestor. Phylogenetic profiling revealed a large difference in the repertoire of outer membrane proteins (including oipA, hopMN, babABC, sabAB and vacA-2 through gene loss, gain, and mutation. All known functions associated with molybdenum, a rare element essential to nearly all organisms that catalyzes two-electron-transfer oxidation-reduction reactions, appeared to be inactivated. Two pathways linking acetyl~CoA and acetate appeared intact in some Japanese strains. Phylogenetic analysis revealed greater divergence between the East Asian (hspEAsia and the European (hpEurope genomes in proteins in host interaction, specifically virulence factors (tipα, outer membrane proteins, and lipopolysaccharide synthesis (human Lewis antigen mimicry enzymes. Divergence was also seen in proteins in electron transfer and translation fidelity (miaA, tilS, a DNA recombinase/exonuclease that recognizes genome identity (addA, and DNA/RNA hybrid nucleases (rnhAB. Positively selected amino acid changes between hspEAsia and hpEurope were mapped to products of cagA, vacA, homC (outer membrane protein, sotB (sugar transport, and a translation fidelity factor (miaA. Large divergence was seen in genes related to antibiotics: frxA (metronidazole resistance, def (peptide deformylase, drug target, and ftsA (actin

  6. A transcriptome map of cellular transformation by the fos oncogene

    Directory of Open Access Journals (Sweden)

    Ruan Hong

    2005-05-01

    Full Text Available Abstract Background The c-fos gene was originally identified as the cellular homolog of the oncogene v-fos carried by the Finkel-Biskis-Jenkins and Finkel-Biskis-Reilly murine osteogenic sarcoma retroviruses. Sustained expression of fos is sufficient to induce cellular transformation in vitro and tumorigenesis in vivo. Fos functions as a component of the AP-1 transcription factor complex to regulate gene transcription and several differentially expressed genes have been identified in cells transformed by fos. We have extended these studies by constructing a cellular system for conditional transformation by v-fos. Using Affymetrix-based DNA microarray technology, we analyzed transcriptional changes over the course of transformation and reversion in an inducible v-fos system. Results Microarray analyses of temporal gene expression during the process of v-fos mediated cellular transformation and morphological reversion revealed a remarkably dynamic transcriptome. Of the more than 8000 genes analyzed in this study, 3766 genes were categorized into 18 gene-expression patterns by using self-organizing map analysis. By combining the analysis of gene expression profiles in stably transformed cells with the analysis of sequential expression patterns during conditional transformation, we identified a relatively small cohort of genes implicated in v-fos mediated cellular transformation. Conclusion This approach defines a general conditional cell transformation system that can be used to study the endogenous transcription regulatory mechanisms involved in transformation and tumorigenesis. In addition, this study is the first reported analysis of dynamic changes in gene expression throughout experimentally controlled morphological transformation mediated by v-fos.

  7. Characterization of a cluster of oncogenic mutations in E6 of a human papillomavirus 83 variant isolated from a high-grade squamous intraepithelial lesion.

    Science.gov (United States)

    Cannavo, Isabelle; Benchetrit, Maxime; Loubatier, Céline; Michel, Gregory; Lemichez, Emmanuel; Giordanengo, Valérie

    2011-10-01

    We previously isolated human papillomavirus 83 (HPV83m) from a cervical smear. Sequence analysis of E6 and E7 proteins highlighted five mutations located in the second putative zinc-finger region of E6 (E6m), an important domain for protein-protein or protein-DNA interactions. Here, we show that E6m of HPV83m can trigger human primary cell proliferation and anchorage-independent growth properties, similarly to E6 of HPV16, a high-risk HPV (HR-HPV). Interestingly, we demonstrate that, in contrast to E6 of HPV16, E6m corrupts neither p53 stability nor telomerase activity, but acts as a specific modulator of the transcriptional machinery. By studying E6m reversion mutants, we confirmed the importance of the second zinc-finger domain in triggering the observed upregulation of cell growth and of the transcriptional machinery. Reversion of these mutations in E6m (to yield strain E6r) fully abolished the oncogenic potential of E6m, transforming the phenotype of E6 from a high-risk to a low-risk phenotype. Importantly, our data define the importance of a cluster of mutations in the second zinc finger of E6m in increasing the oncogenic potential of HPV83.

  8. Structural Basis of the Oncogenic Interaction of Phosphatase PRL-1 with the Magnesium Transporter CNNM2*♦

    Science.gov (United States)

    Giménez-Mascarell, Paula; Oyenarte, Iker; Hardy, Serge; Breiderhoff, Tilman; Stuiver, Marchel; Kostantin, Elie; Diercks, Tammo; Pey, Angel L.; Ereño-Orbea, June; Martínez-Chantar, María Luz; Khalaf-Nazzal, Reham; Claverie-Martin, Felix; Müller, Dominik; Tremblay, Michel L.

    2017-01-01

    Phosphatases of regenerating liver (PRLs), the most oncogenic of all protein-tyrosine phosphatases (PTPs), play a critical role in metastatic progression of cancers. Recent findings established a new paradigm by uncovering that their association with magnesium transporters of the cyclin M (CNNM) family causes a rise in intracellular magnesium levels that promote oncogenic transformation. Recently, however, essential roles for regulation of the circadian rhythm and reproduction of the CNNM family have been highlighted. Here, we describe the crystal structure of PRL-1 in complex with the Bateman module of CNNM2 (CNNM2BAT), which consists of two cystathionine β-synthase (CBS) domains (IPR000664) and represents an intracellular regulatory module of the transporter. The structure reveals a heterotetrameric association, consisting of a disc-like homodimer of CNNM2BAT bound to two independent PRL-1 molecules, each one located at opposite tips of the disc. The structure highlights the key role played by Asp-558 at the extended loop of the CBS2 motif of CNNM2 in maintaining the association between the two proteins and proves that the interaction between CNNM2 and PRL-1 occurs via the catalytic domain of the phosphatase. Our data shed new light on the structural basis underlying the interaction between PRL phosphatases and CNNM transporters and provides a hypothesis about the molecular mechanism by which PRL-1, upon binding to CNNM2, might increase the intracellular concentration of Mg2+ thereby contributing to tumor progression and metastasis. The availability of this structure sets the basis for the rational design of compounds modulating PRL-1 and CNNM2 activities. PMID:27899452

  9. A screen identifies the oncogenic micro-RNA miR-378a-5p as a negative regulator of oncogene-induced senescence.

    Directory of Open Access Journals (Sweden)

    Susanne Marije Kooistra

    Full Text Available Oncogene-induced senescence (OIS can occur in response to hyperactive oncogenic signals and is believed to be a fail-safe mechanism protecting against tumorigenesis. To identify new factors involved in OIS, we performed a screen for microRNAs that can overcome or inhibit OIS in human diploid fibroblasts. This screen led to the identification of miR-378a-5p and in addition several other miRNAs that have previously been shown to play a role in senescence. We show that ectopic expression of miR-378a-5p reduces the expression of several senescence markers, including p16(INK4A and senescence-associated β-galactosidase. Moreover, cells with ectopic expression of miR-378a-5p retain proliferative capacity even in the presence of an activated Braf oncogene. Finally, we identified several miR-378a-5p targets in diploid fibroblasts that might explain the mechanism by which the microRNA can delay OIS. We speculate that miR-378a-5p might positively influence tumor formation by delaying OIS, which is consistent with a known pro-oncogenic function of this microRNA.

  10. Spi-1, Fli-1 and Fli-3 (miR-17-92 oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

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    Samer Kayali

    Full Text Available Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  11. Spi-1, Fli-1 and Fli-3 (miR-17-92) oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Science.gov (United States)

    Kayali, Samer; Giraud, Guillaume; Morlé, François; Guyot, Boris

    2012-01-01

    Clonal erythroleukemia developing in susceptible mice infected by Friend virus complex are associated with highly recurrent proviral insertions at one of three loci called Spi-1, Fli-1 or Fli-3, leading to deregulated expression of oncogenic Spi-1 or Fli-1 transcription factors or miR-17-92 miRNA cluster, respectively. Deregulated expression of each of these three oncogenes has been independently shown to contribute to cell proliferation of erythroleukemic clones. Previous studies showed a close relationship between Spi-1 and Fli-1, which belong to the same ETS family, Spi-1 activating fli-1 gene, and both Spi-1 and Fli-1 activating multiple common target genes involved in ribosome biogenesis. In this study, we demonstrated that Spi-1 and Fli-1 are also involved in direct miR-17-92 transcriptional activation through their binding to a conserved ETS binding site in its promoter. Moreover, we demonstrated that physiological re-expression of exogenous miR-17 and miR-20a are able to partially rescue the proliferation loss induced by Fli-1 knock-down and identified HBP1 as a target of these miRNA in erythroleukemic cells. These results establish that three of the most recurrently activated oncogenes in Friend erythroleukemia are actually involved in a same oncogenic network controlling cell proliferation. The putative contribution of a similar ETS-miR-17-92 network module in other normal or pathological proliferative contexts is discussed.

  12. Investigating the structure and dynamics of the PIK3CA wild-type and H1047R oncogenic mutant.

    Directory of Open Access Journals (Sweden)

    Paraskevi Gkeka

    2014-10-01

    Full Text Available The PIK3CA gene is one of the most frequently mutated oncogenes in human cancers. It encodes p110α, the catalytic subunit of phosphatidylinositol 3-kinase alpha (PI3Kα, which activates signaling cascades leading to cell proliferation, survival, and cell growth. The most frequent mutation in PIK3CA is H1047R, which results in enzymatic overactivation. Understanding how the H1047R mutation causes the enhanced activity of the protein in atomic detail is central to developing mutant-specific therapeutics for cancer. To this end, Surface Plasmon Resonance (SPR experiments and Molecular Dynamics (MD simulations were carried out for both wild-type (WT and H1047R mutant proteins. An expanded positive charge distribution on the membrane binding regions of the mutant with respect to the WT protein is observed through MD simulations, which justifies the increased ability of the mutated protein variant to bind to membranes rich in anionic lipids in our SPR experiments. Our results further support an auto-inhibitory role of the C-terminal tail in the WT protein, which is abolished in the mutant protein due to loss of crucial intermolecular interactions. Moreover, Functional Mode Analysis reveals that the H1047R mutation alters the twisting motion of the N-lobe of the kinase domain with respect to the C-lobe and shifts the position of the conserved P-loop residues in the vicinity of the active site. These findings demonstrate the dynamical and structural differences of the two proteins in atomic detail and propose a mechanism of overactivation for the mutant protein. The results may be further utilized for the design of mutant-specific PI3Kα inhibitors that exploit the altered mutant conformation.

  13. WWP1 as a potential tumor oncogene regulates PTEN-Akt signaling pathway in human gastric carcinoma.

    Science.gov (United States)

    Zhang, Li; Wu, Zongyin; Ma, Zhao; Liu, Hongtao; Wu, Yahong; Zhang, Qinxian

    2015-02-01

    Whelming evidence has demonstrated that WW domain containing E3 ubiquitin protein ligase 1 (WWP1) participates in a wide variety of biological processes and is tightly related to the initiation and progression of many tumors. Currently, although mounting evidence supports a role of WWP1 in tumor promotion and tumorigenesis, the potential roles of WWP1 and its biological functions in gastric carcinoma are not fully understood. Here, we found that WWP1 messenger RNA (mRNA) and protein were highly expressed in gastric carcinoma tissues and cells. High WWP1 mRNA and protein levels were tightly related to differentiation status, TNM stage, invasive depth, lymph node metastasis, and poor prognosis in gastric carcinoma. Furthermore, WWP1 siRNA significantly decreased WWP1 protein level in MKN-45 and AGS cells; meanwhile, WWP1 depletion markedly inhibited tumor proliferation in vitro and in vivo, arrested cell cycle at G0/G1 phase, and induced cell apoptosis in MKN-45 and AGS cells. Most notably, WWP1 downregulation both inactivated PTEN-Akt signaling pathway in MKN-45 and AGS cells. Taken altogether, our findings suggest that WWP1 acts as an oncogenic factor and should be considered as a novel interfering molecular target for gastric carcinoma.

  14. ING proteins in cellular senescence.

    Science.gov (United States)

    Menéndez, Camino; Abad, María; Gómez-Cabello, Daniel; Moreno, Alberto; Palmero, Ignacio

    2009-05-01

    Cellular senescence is an effective anti-tumor barrier that acts by restraining the uncontrolled proliferation of cells carrying potentially oncogenic alterations. ING proteins are putative tumor suppressor proteins functionally linked to the p53 pathway and to chromatin regulation. ING proteins exert their tumor-protective action through different types of responses. Here, we review the evidence on the participation of ING proteins, mainly ING1 and ING2, in the implementation of the senescent response. The currently available data support an important role of ING proteins as regulators of senescence, in connection with the p53 pathway and chromatin organization.

  15. The oncogenic action of ionizing radiation on rat skin

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.J.; Garte, S.J.

    1992-01-01

    The multistage theory of carcinogenesis specifies that cells progress to cancer through a series of discrete, irreversible genetic alterations, but data on radiation-induced cancer incidence in rat skin suggests that an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to an electron beam (LET=0.34 keV/[mu]), a neon ion beam (LET=45) or an argon ion beam (LET=125). The rats were observed for tumors at least 78 weeks with squamous and basal cell carcinomas observed. The total cancer yield was fitted by the quadratic equation, and the equation parameters were estimated by linear regression for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces stable, carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable linked event pathway at high LET; either pathway may advance the cell by 1 stage. The proliferative response of rat epidermis following exposure to ionizing radiation was quantified by injection of [sup 14]C-thymidine. The return of these cells to S-phase a second time was detected by a second label ([sup 3]H). When the labeled cells were in G1-phase, the dorsal skin was irradiated with X-rays. All labeling indices were determined. The [sup 14]C labeling index was constant and unaffected by the radiation. The proportion of all cells entering S-phase averaged 3.5% at 18 hr and increased after 44, 52 and 75 hr to average levels of 11.8%, 5. 3%, and 6.6% at 0, 10 and 25 Gy respectively. The proportion of S-phase cells labeled with [sup 14]C increased after 42 hr and remained relatively constant thereafter.

  16. Oncogenic and RASopathy-associated K-RAS mutations relieve membrane-dependent occlusion of the effector-binding site.

    Science.gov (United States)

    Mazhab-Jafari, Mohammad T; Marshall, Christopher B; Smith, Matthew J; Gasmi-Seabrook, Geneviève M C; Stathopulos, Peter B; Inagaki, Fuyuhiko; Kay, Lewis E; Neel, Benjamin G; Ikura, Mitsuhiko

    2015-05-26

    K-RAS4B (Kirsten rat sarcoma viral oncogene homolog 4B) is a prenylated, membrane-associated GTPase protein that is a critical switch for the propagation of growth factor signaling pathways to diverse effector proteins, including rapidly accelerated fibrosarcoma (RAF) kinases and RAS-related protein guanine nucleotide dissociation stimulator (RALGDS) proteins. Gain-of-function KRAS mutations occur frequently in human cancers and predict poor clinical outcome, whereas germ-line mutations are associated with developmental syndromes. However, it is not known how these mutations affect K-RAS association with biological membranes or whether this impacts signal transduction. Here, we used solution NMR studies of K-RAS4B tethered to nanodiscs to investigate lipid bilayer-anchored K-RAS4B and its interactions with effector protein RAS-binding domains (RBDs). Unexpectedly, we found that the effector-binding region of activated K-RAS4B is occluded by interaction with the membrane in one of the NMR-observable, and thus highly populated, conformational states. Binding of the RAF isoform ARAF and RALGDS RBDs induced marked reorientation of K-RAS4B from the occluded state to RBD-specific effector-bound states. Importantly, we found that two Noonan syndrome-associated mutations, K5N and D153V, which do not affect the GTPase cycle, relieve the occluded orientation by directly altering the electrostatics of two membrane interaction surfaces. Similarly, the most frequent KRAS oncogenic mutation G12D also drives K-RAS4B toward an exposed configuration. Further, the D153V and G12D mutations increase the rate of association of ARAF-RBD with lipid bilayer-tethered K-RAS4B. We revealed a mechanism of K-RAS4B autoinhibition by membrane sequestration of its effector-binding site, which can be disrupted by disease-associated mutations. Stabilizing the autoinhibitory interactions between K-RAS4B and the membrane could be an attractive target for anticancer drug discovery.

  17. RASOnD - A comprehensive resource and search tool for RAS superfamily oncogenes from various species

    Directory of Open Access Journals (Sweden)

    Singh Tej P

    2011-07-01

    Full Text Available Abstract Background The Ras superfamily plays an important role in the control of cell signalling and division. Mutations in the Ras genes convert them into active oncogenes. The Ras oncogenes form a major thrust of global cancer research as they are involved in the development and progression of tumors. This has resulted in the exponential growth of data on Ras superfamily across different public databases and in literature. However, no dedicated public resource is currently available for data mining and analysis on this family. The present database was developed to facilitate straightforward accession, retrieval and analysis of information available on Ras oncogenes from one particular site. Description We have developed the RAS Oncogene Database (RASOnD as a comprehensive knowledgebase that provides integrated and curated information on a single platform for oncogenes of Ras superfamily. RASOnD encompasses exhaustive genomics and proteomics data existing across diverse publicly accessible databases. This resource presently includes overall 199,046 entries from 101 different species. It provides a search tool to generate information about their nucleotide and amino acid sequences, single nucleotide polymorphisms, chromosome positions, orthologies, motifs, structures, related pathways and associated diseases. We have implemented a number of user-friendly search interfaces and sequence analysis tools. At present the user can (i browse the data (ii search any field through a simple or advance search interface and (iii perform a BLAST search and subsequently CLUSTALW multiple sequence alignment by selecting sequences of Ras oncogenes. The Generic gene browser, GBrowse, JMOL for structural visualization and TREEVIEW for phylograms have been integrated for clear perception of retrieved data. External links to related databases have been included in RASOnD. Conclusions This database is a resource and search tool dedicated to Ras oncogenes. It has

  18. Dysfunctional oxidative phosphorylation makes malignant melanoma cells addicted to glycolysis driven by the V600EBRAF oncogene

    DEFF Research Database (Denmark)

    Hall, Arnaldur; Meyle, Kathrine Damm; Lange, Marina Krarup

    2013-01-01

    Oncogene addiction describes how cancer cells exhibit dependence on single oncogenes to escape apoptosis and senescence. While oncogene addiction constitutes the basis for new cancer treatment strategies targeting individual kinases and pathways activated by oncogenic mutations, the biochemical...... basis for this addiction is largely unknown. Here we provide evidence for a metabolic rationale behind the addiction to V600EBRAF in two malignant melanoma cell lines. Both cell lines display a striking addiction to glycolysis due to underlying dysfunction of oxidative phosphorylation (OXPHOS). Notably...

  19. High frequency of the HRAS oncogene codon 12 mutation in Macedonian patients with urinary bladder cancer

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    Sasho Panov

    2004-01-01

    Full Text Available Point mutations at codon 12 of the HRAS (v-Ha-ras Harvey rat sarcoma viral oncogene homolog oncogene are one of the best defined and widely studied molecular genetic events in transitional cell carcinoma (TCC of the urinary bladder. The aim of this study was to use the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP analysis of paraffin-embedded tissue-derived DNA to determine the frequency of the HRAS oncogene G ->T codon 12 mutation in TCC patients being treated at the University Urology Clinic in Skopje, Republic of Macedonia. DNA isolated from paraffin-embedded tissue (PET surgically removed TCC specimens of 62 (81.58% out of 76 patients were successfully amplified, the remaining 14 (18.42% showing compromised DNA integrity. The codon 12 mutation of the HRAS oncogene was found in 24 (38.71% out of 62 successfully tested TCC urinary bladder samples. No significant relationship between the mutation frequency and the histopathological grade of tumor differentiation was detected (chi² = 0.044; p = 0.978. The relatively high frequency of mutations found in our study was comparable with some of the previously reported data obtained by this and/or other PCR-based methods. This highly sensitive and specific PCR-RFLP analysis was demonstrated to be a suitable method for the detection of mutations at codon 12 of the HRAS oncogene in PET samples of urinary bladder TCC.

  20. Limited Role of Murine ATM in Oncogene-Induced Senescence and p53-Dependent Tumor Suppression

    Science.gov (United States)

    Martinez-Pastor, Barbara; Ortega-Molina, Ana; Soria, Rebeca; Collado, Manuel; Fernandez-Capetillo, Oscar; Serrano, Manuel

    2009-01-01

    Recent studies in human fibroblasts have provided a new general paradigm of tumor suppression according to which oncogenic signaling produces DNA damage and this, in turn, results in ATM/p53-dependent cellular senescence. Here, we have tested this model in a variety of murine experimental systems. Overexpression of oncogenic Ras in murine fibroblasts efficiently induced senescence but this occurred in the absence of detectable DNA damage signaling, thus suggesting a fundamental difference between human and murine cells. Moreover, lung adenomas initiated by endogenous levels of oncogenic K-Ras presented abundant senescent cells, but undetectable DNA damage signaling. Accordingly, K-Ras-driven adenomas were also senescent in Atm-null mice, and the tumorigenic progression of these lesions was only modestly accelerated by Atm-deficiency. Finally, we have examined chemically-induced fibrosarcomas, which possess a persistently activated DNA damage response and are highly sensitive to the activity of p53. We found that the absence of Atm favored genomic instability in the resulting tumors, but did not affect the persistent DNA damage response and did not impair p53-dependent tumor suppression. All together, we conclude that oncogene-induced senescence in mice may occur in the absence of a detectable DNA damage response. Regarding murine Atm, our data suggest that it plays a minor role in oncogene-induced senescence or in p53-dependent tumor suppression, being its tumor suppressive activity probably limited to the maintenance of genomic stability. PMID:19421407

  1. Oncofuse: a computational framework for the prediction of the oncogenic potential of gene fusions.

    Science.gov (United States)

    Shugay, Mikhail; Ortiz de Mendíbil, Iñigo; Vizmanos, José L; Novo, Francisco J

    2013-10-15

    Gene fusions resulting from chromosomal aberrations are an important cause of cancer. The complexity of genomic changes in certain cancer types has hampered the identification of gene fusions by molecular cytogenetic methods, especially in carcinomas. This is changing with the advent of next-generation sequencing, which is detecting a substantial number of new fusion transcripts in individual cancer genomes. However, this poses the challenge of identifying those fusions with greater oncogenic potential amid a background of 'passenger' fusion sequences. In the present work, we have used some recently identified genomic hallmarks of oncogenic fusion genes to develop a pipeline for the classification of fusion sequences, namely, Oncofuse. The pipeline predicts the oncogenic potential of novel fusion genes, calculating the probability that a fusion sequence behaves as 'driver' of the oncogenic process based on features present in known oncogenic fusions. Cross-validation and extensive validation tests on independent datasets suggest a robust behavior with good precision and recall rates. We believe that Oncofuse could become a useful tool to guide experimental validation studies of novel fusion sequences found during next-generation sequencing analysis of cancer transcriptomes. Oncofuse is a naive Bayes Network Classifier trained and tested using Weka machine learning package. The pipeline is executed by running a Java/Groovy script, available for download at www.unav.es/genetica/oncofuse.html.

  2. Limited role of murine ATM in oncogene-induced senescence and p53-dependent tumor suppression.

    Directory of Open Access Journals (Sweden)

    Alejo Efeyan

    Full Text Available Recent studies in human fibroblasts have provided a new general paradigm of tumor suppression according to which oncogenic signaling produces DNA damage and this, in turn, results in ATM/p53-dependent cellular senescence. Here, we have tested this model in a variety of murine experimental systems. Overexpression of oncogenic Ras in murine fibroblasts efficiently induced senescence but this occurred in the absence of detectable DNA damage signaling, thus suggesting a fundamental difference between human and murine cells. Moreover, lung adenomas initiated by endogenous levels of oncogenic K-Ras presented abundant senescent cells, but undetectable DNA damage signaling. Accordingly, K-Ras-driven adenomas were also senescent in Atm-null mice, and the tumorigenic progression of these lesions was only modestly accelerated by Atm-deficiency. Finally, we have examined chemically-induced fibrosarcomas, which possess a persistently activated DNA damage response and are highly sensitive to the activity of p53. We found that the absence of Atm favored genomic instability in the resulting tumors, but did not affect the persistent DNA damage response and did not impair p53-dependent tumor suppression. All together, we conclude that oncogene-induced senescence in mice may occur in the absence of a detectable DNA damage response. Regarding murine Atm, our data suggest that it plays a minor role in oncogene-induced senescence or in p53-dependent tumor suppression, being its tumor suppressive activity probably limited to the maintenance of genomic stability.

  3. Viral Oncogenes, Noncoding RNAs, and RNA Splicing in Human Tumor Viruses

    Directory of Open Access Journals (Sweden)

    Zhi-Ming Zheng

    2010-01-01

    Full Text Available Viral oncogenes are responsible for oncogenesis resulting from persistent virus infection. Although different human tumor viruses express different viral oncogenes and induce different tumors, their oncoproteins often target similar sets of cellular tumor suppressors or signal pathways to immortalize and/or transform infected cells. Expression of the viral E6 and E7 oncogenes in papillomavirus, E1A and E1B oncogenes in adenovirus, large T and small t antigen in polyomavirus, and Tax oncogene in HTLV-1 are regulated by alternative RNA splicing. However, this regulation is only partially understood. DNA tumor viruses also encode noncoding RNAs, including viral microRNAs, that disturb normal cell functions. Among the determined viral microRNA precursors, EBV encodes 25 from two major clusters (BART and BHRF1, KSHV encodes 12 from a latent region, human polyomavirus MCV produce only one microRNA from the late region antisense to early transcripts, but HPVs appears to produce no viral microRNAs.

  4. Modulating the strength and threshold of NOTCH oncogenic signals by mir-181a-1/b-1.

    Directory of Open Access Journals (Sweden)

    Rita Fragoso

    Full Text Available Oncogenes, which are essential for tumor initiation, development, and maintenance, are valuable targets for cancer therapy. However, it remains a challenge to effectively inhibit oncogene activity by targeting their downstream pathways without causing significant toxicity to normal tissues. Here we show that deletion of mir-181a-1/b-1 expression inhibits the development of Notch1 oncogene-induced T cell acute lymphoblastic leukemia (T-ALL. mir-181a-1/b-1 controls the strength and threshold of Notch activity in tumorigenesis in part by dampening multiple negative feedback regulators downstream of NOTCH and pre-T cell receptor (TCR signaling pathways. Importantly, although Notch oncogenes utilize normal thymic progenitor cell genetic programs for tumor transformation, comparative analyses of mir-181a-1/b-1 function in normal thymocyte and tumor development demonstrate that mir-181a-1/b-1 can be specifically targeted to inhibit tumor development with little toxicity to normal development. Finally, we demonstrate that mir-181a-1/b-1, but not mir-181a-2b-2 and mir-181-c/d, controls the development of normal thymic T cells and leukemia cells. Together, these results illustrate that NOTCH oncogene activity in tumor development can be selectively inhibited by targeting the molecular networks controlled by mir-181a-1/b-1.

  5. Regulation of autophagy and chloroquine sensitivity by oncogenic RAS in vitro is context-dependent.

    Science.gov (United States)

    Morgan, Michael J; Gamez, Graciela; Menke, Christina; Hernandez, Ariel; Thorburn, Jacqueline; Gidan, Freddi; Staskiewicz, Leah; Morgan, Shellie; Cummings, Christopher; Maycotte, Paola; Thorburn, Andrew

    2014-10-01

    Chloroquine (CQ) is an antimalarial drug and late-stage inhibitor of autophagy currently FDA-approved for use in the treatment of rheumatoid arthritis and other autoimmune diseases. Based primarily on its ability to inhibit autophagy, CQ and its derivative, hydroxychloroquine, are currently being investigated as primary or adjuvant therapy in multiple clinical trials for cancer treatment. Oncogenic RAS has previously been shown to regulate autophagic flux, and cancers with high incidence of RAS mutations, such as pancreatic cancer, have been described in the literature as being particularly susceptible to CQ treatment, leading to the hypothesis that oncogenic RAS makes cancer cells dependent on autophagy. This autophagy "addiction" suggests that the mutation status of RAS in tumors could identify patients who would be more likely to benefit from CQ therapy. Here we show that RAS mutation status itself is unlikely to be beneficial in such a patient selection because oncogenic RAS does not always promote autophagy addiction. Moreover, oncogenic RAS can have opposite effects on both autophagic flux and CQ sensitivity in different cells. Finally, for any given cell type, the positive or negative effect of oncogenic RAS on autophagy does not necessarily predict whether RAS will promote or inhibit CQ-mediated toxicity. Thus, although our results confirm that different tumor cell lines display marked differences in how they respond to autophagy inhibition, these differences can occur irrespective of RAS mutation status and, in different contexts, can either promote or reduce chloroquine sensitivity of tumor cells.

  6. [Epstein-Barr Virus LMP1 oncogene variants in cell lines of different origin].

    Science.gov (United States)

    Yakovleva, L S; Senyuta, N B; Goncharova, E V; Scherback, L N; Smirnova, R V; Pavlish, O A; Gurtsevitch, V E

    2015-01-01

    It is well known that the Epstein-Barr virus (EBV) is a widespread infection in the human population. Typically, infection occurs in early childhood without serious consequences for infected people. At the same time, a secondary infection with an additional EBV strain occurs quite often. During the in vitro cultivation of peripheral blood lymphocytes from persons infected with multiple strains of the virus, only one of these strains with higher transforming potential becomes dominant, while the others are eliminated. Under certain conditions, such a highly transforming EBV strain apparently is able to be the etiologic agent of EBVassociated diseases. To find out the range of highly transforming EBV strains prevalent among Russians, cell lines from patients with EBV-associated and non-associated tumors, as well as healthy individuals, were established. The structural analysis of the latent membrane protein 1 gene (LMP1), a key oncogene of the virus, isolated from established cell lines and peripheral blood lymphocytes of blood donors was carried out, and data obtained were compared with the respective data for LMP1 isolates, amplified from cell lines established from African and Japanese patients with Burkitt's lymphoma. The data obtained show a genetic relationship between Russian LMP1 isolates regardless the fact whether they come from patients with tumors or healthy individuals and differ significantly from LMP1 isolates from Burkitt's lymphoma patients. Thus, the results of the study suggest that in nonendemic region for EBV-associated pathology, Russia, any strain of EBV with any structure of LMP1 with concomitant effect of additional factors may become an etiologic agent for EBV-associated neoplasia.

  7. Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ikuma; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

    2014-12-15

    Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications.

  8. TRIM24 Is an Oncogenic Transcriptional Activator in Prostate Cancer.

    Science.gov (United States)

    Groner, Anna C; Cato, Laura; de Tribolet-Hardy, Jonas; Bernasocchi, Tiziano; Janouskova, Hana; Melchers, Diana; Houtman, René; Cato, Andrew C B; Tschopp, Patrick; Gu, Lei; Corsinotti, Andrea; Zhong, Qing; Fankhauser, Christian; Fritz, Christine; Poyet, Cédric; Wagner, Ulrich; Guo, Tiannan; Aebersold, Ruedi; Garraway, Levi A; Wild, Peter J; Theurillat, Jean-Philippe; Brown, Myles

    2016-06-13

    Androgen receptor (AR) signaling is a key driver of prostate cancer (PC). While androgen-deprivation therapy is transiently effective in advanced disease, tumors often progress to a lethal castration-resistant state (CRPC). We show that recurrent PC-driver mutations in speckle-type POZ protein (SPOP) stabilize the TRIM24 protein, which promotes proliferation under low androgen conditions. TRIM24 augments AR signaling, and AR and TRIM24 co-activated genes are significantly upregulated in CRPC. Expression of TRIM24 protein increases from primary PC to CRPC, and both TRIM24 protein levels and the AR/TRIM24 gene signature predict disease recurrence. Analyses in CRPC cells reveal that the TRIM24 bromodomain and the AR-interacting motif are essential to support proliferation. These data provide a rationale for therapeutic TRIM24 targeting in SPOP mutant and CRPC patients.

  9. Chronic Inhalation Toxicity of Unsymmetrical Dimethylhydrazine: Oncogenic Effects

    Science.gov (United States)

    1984-10-01

    dimethylnitrosamine or by the reaction of dimethylamine with chloramine . Although it is used in photographic chemicals, chemical synthesis and as a plant growth...at various times postexposure. Clinical determinations were made for the following battery of tests: RBC Glucose WBC Total Protein HCT Albumin HGB...more often and clinical determinations made for the following battery of tests: RBC Calcium WBC Glucose HCT Total Protein HGB Albumin Differential

  10. A global view of the oncogenic landscape in nasopharyngeal carcinoma: an integrated analysis at the genetic and expression levels.

    Directory of Open Access Journals (Sweden)

    Chunfang Hu

    Full Text Available Previous studies have reported that the tumour cells of nasopharyngeal carcinoma (NPC exhibit recurrent chromosome abnormalities. These genetic changes are broadly assumed to lead to changes in gene expression which are important for the pathogenesis of this tumour. However, this assumption has yet to be formally tested at a global level. Therefore a genome wide analysis of chromosome copy number and gene expression was performed in tumour cells micro-dissected from the same NPC biopsies. Cellular tumour suppressor and tumour-promoting genes (TSG, TPG and Epstein-Barr Virus (EBV-encoded oncogenes were examined. The EBV-encoded genome maintenance protein EBNA1, along with the putative oncogenes LMP1, LMP2 and BARF1 were expressed in the majority of NPCs that were analysed. Significant downregulation of expression in an average of 76 cellular TSGs per tumour was found, whilst a per-tumour average of 88 significantly upregulated, TPGs occurred. The expression of around 60% of putative TPGs and TSGs was both up-and down-regulated in different types of cancer, suggesting that the simplistic classification of genes as TSGs or TPGs may not be entirely appropriate and that the concept of context-dependent onco-suppressors may be more extensive than previously recognised. No significant enrichment of TPGs within regions of frequent genomic gain was seen but TSGs were significantly enriched within regions of frequent genomic loss. It is suggested that loss of the FHIT gene may be a driver of NPC tumourigenesis. Notwithstanding the association of TSGs with regions of genomic loss, on a gene by gene basis and excepting homozygous deletions and high-level amplification, there is very little correlation between chromosomal copy number aberrations and expression levels of TSGs and TPGs in NPC.

  11. Oncogene-initiated aberrant signaling engenders the metastatic phenotype: synergistic transcription factor interactions are targets for cancer therapy.

    Science.gov (United States)

    Denhardt, D T

    1996-01-01

    Certain p21GTPases (notably Ras) and some of their guanine nucleotide exchange factors (e.g., Ost, Dbl, Tiam) and downstream mediators (e.g., Raf, Myc) have the potential to promote the development of malignancies because they can enhance the transcription of genes that foster the tumorigenic and metastatic phenotype. Among these are genes that stimulate cell proliferation, confer immortality, and facilitate the invasion of normal tissues. Oncogenes upstream of Ras-cell surface receptors such as ErbB2/Neu, Met, or Trk (and their ligands), and nonreceptor cytoplasmic protein tyrosine kinases such as Src and Abl-not only can act through Ras but also contribute additional signals. This review presents a synopsis of our understanding of signaling pathways controlled by the p21GTPases, with a focus on transcription factors regulated by the pathways. Mutations in one or more of the elements in these signaling pathways are invariably found in cancer cells. Crosstalk among the pathways may explain how some forms of stress can contribute to the development of a malignancy. Abnormal signaling leads to modified cytoskeletal structures and permanently altered (i.e., self-sustaining or epigenetic) transcription of target genes. A common therne is that genes whose transcription is elevated to the greatest extent by Ras often have in their promoters juxtaposed binding sites for two different transcription factors (particularly those in the Fos/Jun, CREB/ATF, NFkB, and Ets families) each of which is activated and such that together they synergize to augment transcription substantially. Some of these transcription factors can also act as oncogenes in certain cell types when appropriately modified and expressed. This unifying theme among many different cancers suggests that strategies to restore the balance among the signaling pathways or to suppress synergistic interactions between transcription factors may prove broadly useful in reversing the malignant phenotype.

  12. Cribriform adenocarcinoma of minor salivary glands may express galectin-3, cytokeratin 19, and HBME-1 and contains polymorphisms of RET and H-RAS proto-oncogenes.

    Science.gov (United States)

    Laco, Jan; Kamarádová, Kateřina; Vítková, Pavla; Sehnálková, Eva; Dvořáková, Sárka; Václavíková, Eliška; Sýkorová, Vlasta; Kašpírková, Jana; Skálová, Alena; Ryška, Aleš

    2012-11-01

    The aim of the study was to further elucidate the immunohistochemical and genetic characteristics of cribriform adenocarcinoma of minor salivary glands (CAMSG). The study comprised five CAMSG from two males and three females, aged 21-72 years. Four tumors were localized at the base of tongue and one in the floor of mouth. At the time of diagnosis, four tumors had metastasised to regional lymph nodes. After tumor resection, two patients were treated by radiotherapy and one by chemoradiotherapy. During the follow-up (median 14 months), two patients developed lymph node metastasis. Microscopically, all tumors showed cribriform, papillary, follicular, and microcystic growth patterns. The tumor cells displayed vesicular nuclei with intranuclear grooves. Immunohistochemically, all tumors showed expression of cytokeratin (CK) 7, CK8, CK18, vimentin, smooth muscle actin, calponin, S-100 protein, and p16 protein. In addition, we observed expression of galectin-3, CK19, and HBME-1, but not of thyroglobulin and TTF-1. No mutations of RET, BRAF, K-RAS, H-RAS, and N-RAS proto-oncogenes were detected. However, in RET proto-oncogene, we found polymorphisms Gly691Ser (exon 11) and Ser904Ser (exon 15) in one case, p.Leu769Leu (exon 13) in one case, and variant p.IVS14-24 G/A of intron 14 in two cases, and in H-RAS proto-oncogene we found polymorphism 81 T-C (exon 1) in three cases. Thyroglobulin and TTF-1 are the only useful markers in the differential diagnosis between CAMSG and papillary thyroid carcinoma as both tumors may express galectin-3, CK19, and HBME-1. The RET, H-RAS, and N-RAS proto-oncoogenes are not mutated in CAMSG.

  13. The Oncogenic STP Axis Promotes Triple-Negative Breast Cancer via Degradation of the REST Tumor Suppressor

    Directory of Open Access Journals (Sweden)

    Kristen L. Karlin

    2014-11-01

    Full Text Available Defining the molecular networks that drive breast cancer has led to therapeutic interventions and improved patient survival. However, the aggressive triple-negative breast cancer subtype (TNBC remains recalcitrant to targeted therapies because its molecular etiology is poorly defined. In this study, we used a forward genetic screen to discover an oncogenic network driving human TNBC. SCYL1, TEX14, and PLK1 (“STP axis” cooperatively trigger degradation of the REST tumor suppressor protein, a frequent event in human TNBC. The STP axis induces REST degradation by phosphorylating a conserved REST phospho-degron and bridging REST interaction with the ubiquitin-ligase βTRCP. Inhibition of the STP axis leads to increased REST protein levels and impairs TNBC transformation, tumor progression, and metastasis. Expression of the STP axis correlates with low REST protein levels in human TNBCs and poor clinical outcome for TNBC patients. Our findings demonstrate that the STP-REST axis is a molecular driver of human TNBC.

  14. Mutant p53 potentiates the oncogenic effects of insulin by inhibiting the tumor suppressor DAB2IP.

    Science.gov (United States)

    Valentino, Elena; Bellazzo, Arianna; Di Minin, Giulio; Sicari, Daria; Apollonio, Mattia; Scognamiglio, Giosuè; Di Bonito, Maurizio; Botti, Gerardo; Del Sal, Giannino; Collavin, Licio

    2017-07-18

    Obesity and type 2 diabetes are significant risk factors for malignancies, being associated with chronic inflammation and hyperinsulinemia. In this context, insulin can synergize with inflammation to promote proliferation, survival, and dissemination of cancer cells. Point mutation of p53 is a frequent event and a significant factor in cancer development and progression. Mutant p53 protein(s) (mutp53) can acquire oncogenic properties that increase metastasis, proliferation, and cell survival. We report that breast and prostate cancer cells with mutant p53 respond to insulin stimulation by increasing cell proliferation and invasivity, and that such a response depends on the presence of mutp53. Mechanistically, we find that mutp53 augments insulin-induced AKT1 activation by binding and inhibiting the tumor suppressor DAB2IP (DAB2-interacting protein) in the cytoplasm. This molecular axis reveals a specific gain of function for mutant p53 in the response to insulin stimulation, offering an additional perspective to understand the relationship between hyperinsulinemia and cancer evolution.

  15. A novel post-transcriptional splicing form of the acute T cell leukemia proto-oncogene Lmo2

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Lmo2 is a T cell leukemia-related proto-oncogene, which belongs to the LIM protein family. Previous work has established its key role in yolk sac erythropoiesis and adult hematopoiesis, and it is also necessary for regulating angiogenesis. It has been demonstrated that this gene encodes a protein of 158 amino acids, consisting of two tandem cysteine-rich LIM domains, but the detailed mechanism of its transcriptional regulation remains to be elucidated. To further investigate the mechanism of transcriptional regulation of Lmo2, we combined SMART PCR technology with 5′RACE and found a novel post-transcriptional splicing form of Lmo2 in adult human kidney. This alternative transcript contains only two exons, encoding a smaller protein of 151 amino acids. Interestingly, it shares the same reading frame as the original Lmo2, but differs in 7 amino acids at the N-terminus. A genomic DNA fragment (from ?294 nts to +180 nts) containing the putative promoter region has been inserted into the luciferase reporter gene vector pGL3-basic and showed stable promoter activity when transfected into COS7. RT-PCR analysis revealed that this variant transcript was expressed widely in human tissues and cell lines, suggesting its potential basic functional importance.

  16. HP1a/KDM4A is involved in the autoregulatory loop of the oncogene gene c-Jun.

    Science.gov (United States)

    Liu, Yan; Zhang, Daoyong

    2015-01-01

    The proto-oncogene c-Jun plays crucial roles in tumorigenesis, and its aberrant expression has been implicated in many cancers. Previous studies have shown that the c-Jun gene is positively autoregulated by its product. Notably, it has also been reported that c-Jun proteins are enriched in its gene body region. However, the role of c-Jun proteins in its gene body region has yet to be uncovered. HP1a is an evolutionarily conserved heterochromatin-associated protein, which plays an essential role in heterochromatin-mediated gene silencing. Interestingly, accumulating evidence shows that HP1a is also localized to euchromatic regions to positively regulate gene transcription. However, the underlying mechanism has not been defined. In this study, we demonstrate that HP1a is involved in the positive autoregulatory loop of the Jra gene, the c-Jun homolog in Drosophila. Jra recruits the HP1a/KDM4A complex to its gene body region upon osmotic stress to reduce H3K36 methylation levels and disrupt H3K36 methylation-dependent histone deacetylation, resulting in high levels of histone acetylation in the Jra gene body region, thus promoting gene transcription. These results not only expand our knowledge toward the mechanism of c-Jun regulation, but also reveal the mechanism by which HP1a exerts its positive regulatory function in gene expression.

  17. Role of papillomavirus oncogenes in human cervical cancer: Transgenic animal studies

    Energy Technology Data Exchange (ETDEWEB)

    Griep, A.E.; Lambert, P.F. [Univ. of Wisconsin School of Medicine, Madison, WI (United States)

    1994-05-01

    Human papillomaviruses are believed to be etiologic agents for the majority of human cervical carcinoma, a common cancer that is a leading cause of death by cancer among women worldwide. In cervical carcinoma, a subset of papillomaviral genes, namely E6 and E7, are expressed. In vitro tissue culture studies indicate that HPV E6 and E7 are oncogenes, and that their oncogenicity is due in part to their capacity to inactivate cellular tumor suppressor genes. The behavior of E6 and E7 in vitro and the genetic evidence from analysis of human cancers suggest that the E6 and E7 genes play a significant role in the development of cervical cancer. This hypothesis is now being tested using animal models. In this review, we summarize our current knowledge of the oncogenicity of papillomavirus genes that has been generated through their study in transgenic mice. 82 refs., 4 figs., 1 tab.

  18. Deep-proteome mapping of WM-266-4 human metastatic melanoma cells: From oncogenic addiction to druggable targets

    Science.gov (United States)

    Litou, Zoi I.; Konstandi, Ourania A.; Giannopoulou, Aikaterini F.; Anastasiadou, Ema; Voutsinas, Gerassimos E.; Tsangaris, George Th.; Stravopodis, Dimitrios J.

    2017-01-01

    Cutaneous melanoma is a malignant tumor of skin melanocytes that are pigment-producing cells located in the basal layer (stratum basale) of epidermis. Accumulation of genetic mutations within their oncogenes or tumor-suppressor genes compels melanocytes to aberrant proliferation and spread to distant organs of the body, thereby resulting in severe and/or lethal malignancy. Metastatic melanoma’s heavy mutational load, molecular heterogeneity and resistance to therapy necessitate the development of novel biomarkers and drug-based protocols that target key proteins involved in perpetuation of the disease. To this direction, we have herein employed a nano liquid chromatography-tandem mass spectrometry (nLC-MS/MS) proteomics technology to profile the deep-proteome landscape of WM-266-4 human metastatic melanoma cells. Our advanced melanoma-specific catalogue proved to contain 6,681 unique proteins, which likely constitute the hitherto largest single cell-line-derived proteomic collection of the disease. Through engagement of UNIPROT, DAVID, KEGG, PANTHER, INTACT, CYTOSCAPE, dbEMT and GAD bioinformatics resources, WM-266-4 melanoma proteins were categorized according to their sub-cellular compartmentalization, function and tumorigenicity, and successfully reassembled in molecular networks and interactomes. The obtained data dictate the presence of plastically inter-converted sub-populations of non-cancer and cancer stem cells, and also indicate the oncoproteomic resemblance of melanoma to glioma and lung cancer. Intriguingly, WM-266-4 cells seem to be subjected to both epithelial-to-mesenchymal (EMT) and mesenchymal-to-epithelial (MET) programs, with 1433G and ADT3 proteins being identified in the EMT/MET molecular interface. Oncogenic addiction of WM-266-4 cells to autocrine/paracrine signaling of IL17-, DLL3-, FGF(2/13)- and OSTP-dependent sub-routines suggests their critical contribution to the metastatic melanoma chemotherapeutic refractoriness. Interestingly, the

  19. ONCOGENIC HUMAN PAPILLOMAVIRUS (HPV) INFECTIONS IN 18 TO 24 YEAR OLD FEMALE ONLINE DATERS

    Science.gov (United States)

    Barrere, Alexis; Stern, Joshua E.; Feng, Qinghua; Hughes, James P.; Winer, Rachel L.

    2015-01-01

    Background While risk factors for HPV infections in young women are well-defined, the risk associated with meeting male sex partners via the internet is unclear. Methods We analyzed cross-sectional data from 282 18-24-year old women who reported using Internet dating websites in the past year. Women were mailed vaginal self-sampling kits for PCR-based HPV genotyping (including 19 oncogenic types) and sexual behavior and health history questionnaires. Generalized linear models were used to evaluate risk factors for prevalent oncogenic HPV infections. Results 35% of women reported having met a male sex partner via the Internet in the past 6 months, and 42% reported a history of HPV vaccination. The prevalence of oncogenic HPV infection was 37%, and 9% of women tested positive for HPV-16 or HPV-18. Having met a male sex partner via the Internet in the past 6 months was not significantly associated with oncogenic HPV infection. In multivariate analyses, variables associated with an increased likelihood of oncogenic HPV infection included male partners in the past 6 months who were reported to have ≥1 concurrent partnership (adjusted prevalence ratio [aPR]=1.51,95%CI:1.11-2.06) and not always using condoms with male partners in the past 6 months (aPR=1.86,95%CI:1.05-3.30). Self-reporting a history of receiving ≥1 dose of HPV vaccine was inversely associated with testing positive for HPV-16 or HPV-18 (aPR=0.39,95%CI:0.16–0.97). Conclusions While measures of recent sexual behavior were associated with prevalent oncogenic HPV infection, male partners met online were not associated with an increased likelihood of infection in this cohort of young women. PMID:26267875

  20. A view on EGFR-targeted therapies from the oncogene-addiction perspective

    Directory of Open Access Journals (Sweden)

    Rolando ePerez

    2013-04-01

    Full Text Available Tumor cell growth and survival can often be impaired by inactivating a single oncogen – a phenomenon that has been called as 'oncogene addiction'. It is in such scenarios that molecular targeted therapies may succeed. Among known oncogenes, the epidermal growth factor receptor (EGFR has become the target of different cancer therapies. So far, however, the clinical benefit from EGFR-targeted therapies has been rather limited. A critical review of the large amount of clinical data obtained with anti-EGFR agents, carried out from the perspective of the oncogene addiction concept, may help to understand the causes of the unsatisfactory results. In this article we intend to do such an exercise taking as basis for the analysis a few case studies of anti-EGFR agents that are currently in the clinic. There, the 'EGFR addiction' phenomenon becomes apparent in high-responder patients. We further discuss how the concept of oncogene addiction needs to be interpreted on the light of emerging experimental evidences and ideas; in particular, that EGFR addiction may reflect the interconnection of several cellular pathways. In this regard we set forth several hypotheses; namely, that requirement of higher glucose uptake by hypoxic tumor cells may reinforce EGFR addiction; and that chronic use of EGFR-targeted antibodies in EGFR-addicted tumors would induce stable disease by reversing the malignant phenotype of cancer stem cells and also by sustaining an anti-tumor T cell response. Finally, we discuss possible reasons for the failure of certain combinatorial therapies involving anti-EGFR agents, arguing that some of these agents might produce either a negative or a positive trans-modulation effect on other oncogenes. It becomes evident that we need operational definitions of EGFR addiction in order to determine which patient populations may benefit from treatment with anti-EGFR drugs, and to improve the design of these therapies.

  1. [Oncogenic human papillomaviruses in extra-genital Bowen disease revealed by in situ hybridization].

    Science.gov (United States)

    Derancourt, C; Mougin, C; Chopard Lallier, M; Coumes-Marquet, S; Drobacheff, C; Laurent, R

    2001-01-01

    The association between mucosal oncogenic human papillomaviruses (HPV) and bowenoid papulosis or genital Bowen's disease is well documented. In contrast this association with extra-genital Bowen's disease is poorly studied. The aim of this study was to detect oncogenic (16/18, 31/33/51) and non oncogenic (8/11) mucosal HPV using a in situ hybridization method in 28 skin biopsy specimens of extra-genital Bowen's disease. Twenty-eight cases of extra-genital Bowen's disease seen in the period 1990-96 in the Dermatology department were included: 19 women and 9 men (mean age: 72 years). Bowen's disease locations were: hands and feet (8 cases), limbs (11 cases), face (8 cases), trunk (1 case). Blinded histopathologic examination confirmed the diagnosis of Bowen's disease and signs of HPV infection (koilocytosis). In situ hybridization was performed using three biotinylated probes detecting HPV types 6/11, 16/18, 31/33/51. Oncogenic HPV genoma was detected in 8 skin samples (28.6 p. 100). In all these cases, 16/18 probe was positive and in two cases, both 16/18 and 31/33/51 probes were positive; 4/8 Bowen's diseases of the extremities were positive for HPV. Koilocytes were found in 6/8 of skin samples with positive HPV detection. Mucosal oncogenic HPV are detected by in situ hybridization in 28.6 p. 100 of extra-genital Bowen's disease. In situ hybridization is an easier technique than Southern-Blot hybridization which is the gold standard. Five studies reported similar results and three studies reported different results that we discuss. A precise understanding of oncogenic HPV implication in the development of extra-genital Bowen's disease could lead to the development of new therapeutic strategies (topical cidofovir or imiquimod).

  2. A Screen Identifies the Oncogenic Micro-RNA miR-378a-5p as a Negative Regulator of Oncogene-Induced Senescence

    DEFF Research Database (Denmark)

    Kooistra, Susanne Marije; Rudkjær, Lise Christine; Lees, Michael James;

    2014-01-01

    fibroblasts. This screen led to the identification of miR-378a-5p and in addition several other miRNAs that have previously been shown to play a role in senescence. We show that ectopic expression of miR-378a-5p reduces the expression of several senescence markers, including p16INK4A and senescence......-associated β-galactosidase. Moreover, cells with ectopic expression of miR-378a-5p retain proliferative capacity even in the presence of an activated Braf oncogene. Finally, we identified several miR-378a-5p targets in diploid fibroblasts that might explain the mechanism by which the microRNA can delay OIS. We...... speculate that miR-378a-5p might positively influence tumor formation by delaying OIS, which is consistent with a known pro-oncogenic function of this microRNA....

  3. Oncogenic osteomalacia secondary to a hemangiopericytoma of the hip: case report

    Energy Technology Data Exchange (ETDEWEB)

    Baronofsky, S.I.; Kalbhen, C.L.; Demos, T.C.; Sizemore, G.W. [Loyola Univ. Medical Center, Dept. of Medicine, Maywood, IL (United States)

    1999-02-01

    Osteomalacia is characterized by abnormally increased unmineralized osteoid within the bone matrix. This metabolic bone disease is usually the result of decreased uptake or abnormal metabolism of vitamin D or of renal tubular phosphate loss. Dietary deficiency, malabsorption, cirrhosis, renal tubular acidosis and certain drugs can cause osteomalacia., Oncogenic osteomalacia - osteomalacia secondary to tumours - is rare, and the exact mechanisms by which neoplasms induce osteomalacia are not known. We describe a patient with chronic osteomalacia of unknown origin who was subsequently found to have oncogenic osteomalacia secondary to a hemangiopericytoma of the hip. (author)

  4. LTβR signalling preferentially accelerates oncogenic AKT-initiated liver tumours

    Science.gov (United States)

    Scarzello, Anthony J; Jiang, Qun; Back, Timothy; Dang, Hien; Hodge, Deborah; Hanson, Charlotte; Subleski, Jeffrey; Weiss, Jonathan M; Stauffer, Jimmy K; Chaisaingmongkol, Jitti; Rabibhadana, Siritida; Ruchirawat, Mathuros; Ortaldo, John; Wang, Xin Wei; Norris, Paula S; Ware, Carl F; Wiltrout, Robert H

    2016-01-01

    Objectives The relative contributions of inflammatory signalling and sequential oncogenic dysregulation driving liver cancer pathogenesis remain incompletely understood. Lymphotoxin-β receptor (LTβR) signalling is critically involved in hepatitis and liver tumorigenesis. Therefore, we explored the interdependence of inflammatory lymphotoxin signalling and specific oncogenic pathways in the progression of hepatic cancer. Design Pathologically distinct liver tumours were initiated by hydrodynamic transfection of oncogenic V-Akt Murine Thymoma Viral Oncogene Homolog 1 (AKT)/β-catenin or AKT/Notch expressing plasmids. To investigate the relationship of LTβR signalling and specific oncogenic pathways, LTβR antagonist (LTβR-Fc) or agonist (anti-LTβR) were administered post oncogene transfection. Initiated livers/tumours were investigated for changes in oncogene expression, tumour proliferation, progression, latency and pathology. Moreover, specific LTβR-mediated molecular events were investigated in human liver cancer cell lines and through transcriptional analyses of samples from patients with intrahepatic cholangiocarcinoma (ICC). Results AKT/β-catenin-transfected livers displayed increased expression of LTβ and LTβR, with antagonism of LTβR signalling reducing tumour progression and enhancing survival. Conversely, enforced LTβR-activation of AKT/β-catenin-initiated tumours induced robust increases in proliferation and progression of hepatic tumour phenotypes in an AKT-dependent manner. LTβR-activation also rapidly accelerated ICC progression initiated by AKT/Notch, but not Notch alone. Moreover, LTβR-accelerated development coincides with increases of Notch, Hes1, c-MYC, pAKT and β-catenin. We further demonstrate LTβR signalling in human liver cancer cell lines to be a regulator of Notch, pAKTser473 and β-catenin. Transcriptome analysis of samples from patients with ICC links increased LTβR network expression with poor patient survival, increased

  5. A Screen Identifies the Oncogenic Micro-RNA miR-378a-5p as a Negative Regulator of Oncogene-Induced Senescence

    DEFF Research Database (Denmark)

    Kooistra, Susanne Marije; Rudkjær, Lise Christine; Lees, Michael James

    2014-01-01

    fibroblasts. This screen led to the identification of miR-378a-5p and in addition several other miRNAs that have previously been shown to play a role in senescence. We show that ectopic expression of miR-378a-5p reduces the expression of several senescence markers, including p16INK4A and senescence......Oncogene-induced senescence (OIS) can occur in response to hyperactive oncogenic signals and is believed to be a fail-safe mechanism protecting against tumorigenesis. To identify new factors involved in OIS, we performed a screen for microRNAs that can overcome or inhibit OIS in human diploid......-associated β-galactosidase. Moreover, cells with ectopic expression of miR-378a-5p retain proliferative capacity even in the presence of an activated Braf oncogene. Finally, we identified several miR-378a-5p targets in diploid fibroblasts that might explain the mechanism by which the microRNA can delay OIS. We...

  6. Uncoupling of the LKB1-AMPKalpha energy sensor pathway by growth factors and oncogenic BRAF.

    Directory of Open Access Journals (Sweden)

    Rosaura Esteve-Puig

    Full Text Available BACKGROUND: Understanding the biochemical mechanisms contributing to melanoma development and progression is critical for therapeutical intervention. LKB1 is a multi-task Ser/Thr kinase that phosphorylates AMPK controlling cell growth and apoptosis under metabolic stress conditions. Additionally, LKB1(Ser428 becomes phosphorylated in a RAS-Erk1/2-p90(RSK pathway dependent manner. However, the connection between the RAS pathway and LKB1 is mostly unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using the UV induced HGF transgenic mouse melanoma model to investigate the interplay among HGF signaling, RAS pathway and PI3K pathway in melanoma, we identified LKB1 as a protein directly modified by HGF induced signaling. A variety of molecular techniques and tissue culture revealed that LKB1(Ser428 (Ser431 in the mouse is constitutively phosphorylated in BRAF(V600E mutant melanoma cell lines and spontaneous mouse tumors with high RAS pathway activity. Interestingly, BRAF(V600E mutant melanoma cells showed a very limited response to metabolic stress mediated by the LKB1-AMPK-mTOR pathway. Here we show for the first time that RAS pathway activation including BRAF(V600E mutation promotes the uncoupling of AMPK from LKB1 by a mechanism that appears to be independent of LKB1(Ser428 phosphorylation. Notably, the inhibition of the RAS pathway in BRAF(V600E mutant melanoma cells recovered the complex formation and rescued the LKB1-AMPKalpha metabolic stress-induced response, increasing apoptosis in cooperation with the pro-apoptotic proteins Bad and Bim, and the down-regulation of Mcl-1. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that growth factor treatment and in particular oncogenic BRAF(V600E induces the uncoupling of LKB1-AMPKalpha complexes providing at the same time a possible mechanism in cell proliferation that engages cell growth and cell division in response to mitogenic stimuli and resistance to low energy conditions in tumor cells. Importantly, this

  7. Aggressive transformation of juvenile myelomonocytic leukemia associated with duplication of oncogenic KRAS due to acquired uniparental disomy.

    Science.gov (United States)

    Kato, Motohiro; Yasui, Naoko; Seki, Masafumi; Kishimoto, Hiroshi; Sato-Otsubo, Aiko; Hasegawa, Daisuke; Kiyokawa, Nobutaka; Hanada, Ryoji; Ogawa, Seishi; Manabe, Atsushi; Takita, Junko; Koh, Katsuyoshi

    2013-06-01

    A small fraction of cases of juvenile myelomonocytic leukemia (JMML) develop massive disease activation. Through genomic analysis of JMML, which developed in an individual with mosaicism for oncogenic KRAS mutation with rapid progression, we identified acquired uniparental disomy at 12p. We demonstrated that duplication of oncogenic KRAS is associated with rapid JMML progression.

  8. Deletion mutants of region E1 a of AD12 E1 plasmids: Effect on oncogenic transformation

    NARCIS (Netherlands)

    Bos, J.L.; Jochemsen, A.G.; Bernards, R.A.; Schrier, P.I.; Ormondt, H. van; Eb, A.J. van der

    1983-01-01

    Plasmids containing the El region of Ad12 DNA can transform certain rodent cells into oncogenic cells. To study the role of the Ela subregion in the process of oncogenic transformation, Ad12 region El mutants carrying deletions in the Ela region were constructed. Deletion mutants pR7 and pR8 affect

  9. Effects of c-myc oncogene modulation on differentiation of human small cell lung carcinoma cell lines

    NARCIS (Netherlands)

    Van Waardenburg, RCAM; Meijer, C; Pinto-Sietsma, SJ; De Vries, EGE; Timens, W; Mulder, NM

    1998-01-01

    Amplification and over-expression of oncogenes of the myc family are related to the prognosis of certain solid tumors such as small cell lung cancer (SCLC). For SCLC, c-myc is the oncogene most consistently found to correlate with the end stage behaviour of the tumour, in particular with survival af

  10. Inhibition of cervical cancer cell growth in vitro and in vivo with lentiviral-vector delivered short hairpin RNA targeting human papillomavirus E6 and E7 oncogenes.

    Science.gov (United States)

    Gu, W; Putral, L; Hengst, K; Minto, K; Saunders, N A; Leggatt, G; McMillan, N A J

    2006-11-01

    In this study, we investigated the suppressive effect of a short hairpin RNA delivered by a lentiviral vector (LV-shRNA) against human papillomavirus (HPV) type 18 E6 on the expression of the oncogenes E6 and E7 in cervical cancer HeLa cells both in vitro and in vivo. The LV-shRNA effectively delivered the shRNA to HeLa cells and lead to a dose-dependent reduction of E7 protein and the stabilization of E6 target proteins, p53 and p21. Low-dose infection of HeLa cells with LV-shRNA caused reduced cell growth and the induction of senescence, whereas a high-dose infection resulted in specific cell death via apoptosis. Transplant of HeLa cells infected with a low dose of LV-shRNA into Rag-/- mice significantly reduced the tumor weight, whereas transplant of cells infected with a high dose resulted in a complete loss of tumor growth. Systemic delivery of LV-shRNA into mice with established HeLa cell lung metastases led to a significant reduction in the number of tumor nodules. Our data collectively suggest that lentiviral delivery is an effective way to achieve stable suppression of E6/E7 oncogene expression and induce inhibition of tumor growth both in vitro and in vivo. These results encourage further investigation of this form of RNA interference as a promising treatment for cervical cancer.

  11. Serine phosphorylation of NPM-ALK, which is dependent on the auto-activation of the kinase activation loop, contributes to its oncogenic potential.

    Science.gov (United States)

    Wang, Peng; Wu, Fang; Zhang, Jingdong; McMullen, Todd; Young, Leah C; Ingham, Robert J; Li, Liang; Lai, Raymond

    2011-02-01

    It is well established that the tumorigenic potential of nucleophosmin (NPM)-anaplastic lymphoma kinase (ALK), an oncogenic tyrosine kinase, is dependent on its tyrosine phosphorylation. Using tandem affinity purification-mass spectrometry, we found evidence of phosphorylation of three serine residues of NPM-ALK (Serine¹³⁵, Serine¹⁶⁴ and Serine⁴⁹⁷) ectopically expressed in GP293 cells. Using a specific anti-phosphoserine antibody and immunoprecipitation, we confirmed the presence of serine phosphorylation of NPM-ALK in all three NPM-ALK-expressing cell lines examined. Similar to the tyrosine phosphorylation, phosphorylation of these serine residues was dependent on the activation status of the kinase activation loop of ALK. All of these three serine residues are biologically important as mutation of any one of these residues resulted in a significant reduction in the tumorigenicity of NPM-ALK (assessed by cell viability and clonogenic assay), which correlated with a substantial reduction in the phosphorylation of extracellular signal-regulated kinase 1/2, c-jun N-terminal kinase and signal transducer and activator of transcription 6. Serine phosphorylation of NPM-ALK appears to be regulated by multiple serine kinases since it was markedly reduced by pharmacologic inhibitors for glycogen synthase kinase-3, casein kinase I or mitogen-activated protein kinases. In summary, our study is the first to identify serine phosphorylation of NPM-ALK and to provide evidence that it enhances the tumorigenic potential of this oncogenic protein.

  12. Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche

    Science.gov (United States)

    Van Doorslaer, Koenraad; DeSalle, Rob; Einstein, Mark H.; Burk, Robert D.

    2015-01-01

    In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential) is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution. PMID:26086730

  13. Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche.

    Directory of Open Access Journals (Sweden)

    Koenraad Van Doorslaer

    2015-06-01

    Full Text Available In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution.

  14. Degradation of Human PDZ-Proteins by Human Alphapapillomaviruses Represents an Evolutionary Adaptation to a Novel Cellular Niche.

    Science.gov (United States)

    Van Doorslaer, Koenraad; DeSalle, Rob; Einstein, Mark H; Burk, Robert D

    2015-06-01

    In order to complete their life cycle, papillomaviruses have evolved to manipulate a plethora of cellular pathways. The products of the human Alphapapillomavirus E6 proteins specifically interact with and target PDZ containing proteins for degradation. This viral phenotype has been suggested to play a role in viral oncogenesis. To analyze the association of HPV E6 mediated PDZ-protein degradation with cervical oncogenesis, a high-throughput cell culture assay was developed. Degradation of an epitope tagged human MAGI1 isoform was visualized by immunoblot. The correlation between HPV E6-induced degradation of hMAGI1 and epidemiologically determined HPV oncogenicity was evaluated using a Bayesian approach within a phylogenetic context. All tested oncogenic types degraded the PDZ-containing protein hMAGI1d; however, E6 proteins isolated from several related albeit non-oncogenic viral types were equally efficient at degrading hMAGI1. The relationship between both traits (oncogenicity and PDZ degradation potential) is best explained by a model in which the potential to degrade PDZ proteins was acquired prior to the oncogenic phenotype. This analysis provides evidence that the ancestor of both oncogenic and non-oncogenic HPVs acquired the potential to degrade human PDZ-containing proteins. This suggests that HPV E6 directed degradation of PDZ-proteins represents an ancient ecological niche adaptation. Phylogenetic modeling indicates that this phenotype is not specifically correlated with oncogenic risk, but may act as an enabling phenotype. The role of PDZ protein degradation in HPV fitness and oncogenesis needs to be interpreted in the context of Alphapapillomavirus evolution.

  15. EFFECTS OF LIMONENE, SALVIA MILTIORRHIZA AND TURMERIC DERIVATIVES ON H-RAS ONCOGENE EXPRESSION AND GAP JUNCTION INTERCELLULAR COMMUNICATION IN HUMAN SOLID TUMOR CELL LINES

    Institute of Scientific and Technical Information of China (English)

    Chen Xiaoguang; Taday oshi Hasuma; Yoshihisa Yano; Toshiko Yoshimata; Hiyoshi Kamoi; Shuzo Otani

    1998-01-01

    Objective: To study gap junction intercellular communication (GJIC), H-ras oncogene expression and ras oncogene product (P21 ras protein) expression in four human solid tumor cell lines, W1-38, CACO2, A549 and PaCa, and the effects of four compounds, Salvia miltiorrhiza derivative (SMD), d-Limonene, Turmeric derivative Ⅰ (TD-Ⅰ) and Turmeric derivative Ⅱ (TD-Ⅱ), on them. Methods: The abilities of the four solid tumor cell lines to transfer dye to adjacent cells were examined by the scrape-loading/dye transfer technique, and the Hras oncogene expression by Northern blotting and P21 ras protein expression by Western blotting. Results: The results showed the loss of intercellular coupling in PaCa cells, slight GJIC in A549 and CACO2 cells, and a good GJIC in W1-38 cells. The four compounds could improve the GJIC of PaCa to different extents. The amount of total and membrane associated P21 ras in PaCa cells were decreased after treatment with SMD, d-Limonene and TD-Ⅰ (2.5 μg/ml) for 48 h. Concomitantly, the growth of PaCa cells decreased in soft agar and had enhanced GJIC.The relative potency was found to be:d-Limonene>SMD >TD-Ⅰ=TD-Ⅱ. There was no significant effect of the four compounds on H-ras oncogene expression. Conclusion:It was suggested that there was an excellent correlation between loss of Lucifer Yellow dye transfer and ras gene mutation rate in the four solid tumor cell lines (ras gene mutation rate inversely correlated with average cell number coupled, r=0.98) i.e., the high ras gene mutation was closely correlated with loss of GJIC in these malignant human tumor cells; The antitumor effect of the monoterpene d-Limonene and the phenol compound,SMD, might be related to inhibition of P21 ras membrane association and enhancement of GJIC, whilst that of the others may be by a different mechanism; The inhibition of p21 ras membrane association was directly related to the enhancement of gap junction intercellular communication.

  16. Histone Code Modulation by Oncogenic PWWP-domain Protein in Breast Cancers

    Science.gov (United States)

    2013-06-01

    fluorescence in situ hybridization (FISH) and Southern blot analysis were used to map the 9p23-24 amplicon. Northern blotting was implemented to detect...addition, recently published data from the other labs also indicated that knockdown of WHSC1L1 inhibits cell growth of the 8p12 amplified, ER-positive...specifically H3K36 methylation marks (14). Therefore, we assessed global methylation (H3K4, H3K9, H3K27 and H3K36) levels by using western blotting in a

  17. Regulation of Protein Kinase B Tyrosine Phosphorylation by Thyroid-Specific Oncogenic RET/PTC Kinases

    National Research Council Canada - National Science Library

    Jung, Hye Sook; Kim, Dong Wook; Jo, Young Suk; Chung, Hyo Kyun; Song, Jung Hun; Park, Jong Sun; Park, Ki Cheol; Park, Su Hyeon; Hwang, Jung Hwan; Jo, Ki-Won; Shong, Minho

    2005-01-01

    Papillary thyroid carcinoma (PTC) is a heterogenous disorder characterized by unique gene rearrangements and gene mutations that activate signaling pathways responsible for cellular transformation, survival, and antiapoptosis...

  18. Histone Code Modulation by Oncogenic PWWP-Domain Protein in Breast Cancers

    Science.gov (United States)

    2014-08-01

    breast and colorectal cancers. Science 314: 268–274. Solomon DA, Kim JS, Cronin JC, Sibenaller Z, Ryken T, Rosenberg SA et al. (2008). Mutational...Beroukhim R, Mermel CH, Loda M, Ait-Si- Ali S, Garraway LA, Young RA and Zon LI. The histone methyltrans- ferase SETDB1 is recurrently amplified in mela

  19. Immunology in the clinic review series; focus on cancer: multiple roles for the immune system in oncogene addiction.

    Science.gov (United States)

    Bachireddy, P; Rakhra, K; Felsher, D W

    2012-02-01

    Despite complex genomic and epigenetic abnormalities, many cancers are irrevocably dependent on an initiating oncogenic lesion whose restoration to a normal physiological activation can elicit a dramatic and sudden reversal of their neoplastic properties. This phenomenon of the reversal of tumorigenesis has been described as oncogene addiction. Oncogene addiction had been thought to occur largely through tumour cell-autonomous mechanisms such as proliferative arrest, apoptosis, differentiation and cellular senescence. However, the immune system plays an integral role in almost every aspect of tumorigenesis, including tumour initiation, prevention and progression as well as the response to therapeutics. Here we highlight more recent evidence suggesting that oncogene addiction may be integrally dependent upon host immune-mediated mechanisms, including specific immune effectors and cytokines that regulate tumour cell senescence and tumour-associated angiogenesis. Hence, the host immune system is essential to oncogene addiction.

  20. Using {sup 18F} FDG PET/CT to Detect an occult Mesenchymal Tumor Causing Oncogenic Osteomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyo Jung; Choi, Yun Jung; Kim, Hyun Jeong; Jeong, Yong Hyu; Cho, Arthur; Lee, Jae Hoon; Yun, Mijin; Lee, Jong Doo; Kang, Won Jun [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    2011-09-15

    Oncogenic osteomalacia is a rare paraneoplastic syndrome characterized by renal phosphate excretion, hypophosphatemia, and osteomalacia. This syndrome is often caused by tumors of mesenchymal origin. Patients with oncogenic osteomalacia have abnormal bone mineralization, resulting in a high frequency of fractures. Tumor resection is the treatment of choice, as it will often correct the metabolic imbalance. Although oncogenic osteomalacia is a potentially curable disease, diagnosis is difficult and often delayed because of the small size and sporadic location of the tumor. Bone scintigraphy and radiography best characterize osteoma lacia; magnetic resonance imaging findings are nonspecific. Here, we report a case of oncogenic osteomalacia secondary to a phosphaturic mesenchymal tumor that was successfully detected by {sup 18F} fluorodeoxyglucose positron emission tomography/computed tomography ({sup 18F} FDG PET/CT). This case illustrates the advantages of {sup 18F} FDG PET/CT in detecting the occult mesenchymal tumor that causes oncogenic osteomalacia.

  1. N-Linked oligosaccharide changes with oncogenic transformation require sialylation of multiantennae

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Santer, U.V.; DeSantis, R.; Hård, K.; Kuik, J.A. van; Won, B.; Glick, M.C.

    1989-01-01

    Glycopeptides derived from NIH 3T3 fibroblasts and these cells transformed by transfection with human DNA containing oncogene H-ras were analyzed by 500-MHz 1H-NMR spectroscopy and binding to immobilized lectins. The cells were metabolically labeled with D-[3H]glucosamine or L-[3H]fucose and the gly

  2. Escape from premature senescence is not sufficient for oncogenic transformation by Ras

    NARCIS (Netherlands)

    Peeper, D.S.; Dannenberg, J.-H.; Douma, S.; Riele, H. te; Bernards, R.A.

    2001-01-01

    Resistance of primary cells to transformation by oncogenic Ras has been attributed to the induction of replicative growth arrest1, 2, 3. This irreversible 'fail-safe mechanism' resembles senescence and requires induction by Ras of p19ARF and p53 (refs 3−5). Mutation of either p19ARF or p53 alleviate

  3. Somatic Copy Number Alterations at Oncogenic Loci Show Diverse Correlations with Gene Expression

    Science.gov (United States)

    Roszik, Jason; Wu, Chang-Jiun; Siroy, Alan E.; Lazar, Alexander J.; Davies, Michael A.; Woodman, Scott E.; Kwong, Lawrence N.

    2016-01-01

    Somatic copy number alterations (SCNAs) affecting oncogenic drivers have a firmly established role in promoting cancer. However, no agreed-upon standard exists for calling locus-specific amplifications and deletions in each patient sample. Here, we report the correlative analysis of copy number amplitude and length with gene expression across 6,109 samples from The Cancer Genome Atlas (TCGA) dataset across 16 cancer types. Using specificity, sensitivity, and precision-based scores, we assigned optimized amplitude and length cutoffs for nine recurrent SCNAs affecting known oncogenic drivers, using mRNA expression as a functional readout. These cutoffs captured the majority of SCNA-driven, highly-expression-altered samples. The majority of oncogenes required only amplitude cutoffs, as high amplitude samples were almost invariably focal; however, CDKN2A and PTEN uniquely required both amplitude and length cutoffs as primary predictors. For PTEN, these extended to downstream AKT activation. In contrast, SCNA genes located peri-telomerically or in fragile sites showed poor expression-copy number correlations. Overall, our analyses identify optimized amplitude and length cutoffs as efficient predictors of gene expression changes for specific oncogenic SCNAs, yet warn against one-size-fits-all interpretations across all loci. Our results have implications for cancer data analyses and the clinic, where copy number and mutation data are increasingly used to personalize cancer therapy.

  4. Clinical relevance of the K-ras oncogene in colorectal cancer: Experience in a Mexican population

    Directory of Open Access Journals (Sweden)

    F. Cabrera-Mendoza

    2014-07-01

    Conclusions: No relation was found between the K-ras oncogene mutation and reduced survival, in contrast to what has been established in the international medical literature. Further studies that include both a larger number of patients and those receiving monoclonal treatment, need to be conducted. There were only 5 patients in the present study that received cetuximab, resulting in a misleading analysis.

  5. Oncogenic events associated with endometrial and ovarian cancers are rare in endometriosis

    DEFF Research Database (Denmark)

    Vestergaard, Anna Lindeløv; Thorup, Katrine; Knudsen, Ulla Breth

    2011-01-01

    using methylation-specific melting curve analysis (MS-MCA), and 9 genes (BRAF, HRAS, NRAS, CTNNB1, CDK4, FGFR3, PIK3CA, TP53 and PTEN) were analyzed for mutations using denaturing gradient gel electrophoresis (DGGE) and direct sequencing. An oncogenic mutation in KRAS (c. 34G>T; p.G12C) was detected...

  6. Assessment of human papillomavirus E6/E7 oncogene expression as cervical disease biomarker

    National Research Council Canada - National Science Library

    Fontecha, Nerea; Basaras, Miren; Hernáez, Silvia; Andía, Daniel; Cisterna, Ramón

    2016-01-01

    .... After RNA extraction, E6/E7 oncogene mRNA detection was performed by NucliSens[R] EasyQ[R] HPV v1 Test (bioM#241;rieux). The results of the present study showed that E6/E7 mRNA positivity rate...

  7. Microarray-Based oncogenic pathway profiling in advanced serous papillary ovarian carcinoma

    NARCIS (Netherlands)

    X.B. Trinh; W.A.A. Tjalma (Wiebren); L. Dirix (Luc); P.B. Vermeulen; D. Peeters (Dieter); D. Bachvarov (Dimcho); M. Plante (Marie); P.M.J.J. Berns (Els); J. Helleman (Jozien); S.J. van Laere; P.A. van Dam

    2011-01-01

    textabstractIntroduction: The identification of specific targets for treatment of ovarian cancer patients remains a challenge. The objective of this study is the analysis of oncogenic pathways in ovarian cancer and their relation with clinical outcome. Methodology: A meta-analysis of 6 gene expressi

  8. Gene expression of oncogenes, antimicrobial peptides, and cytokines in the development of oral leukoplakia.

    NARCIS (Netherlands)

    Wenghoefer, M.; Pantelis, A.; Najafi, T.; Deschner, J.; Allam, J.P.; Novak, N.; Reich, R.; Martini, M.; Berge, S.J.; Fischer, H.P.; Jepsen, S.; Winter, J.

    2010-01-01

    OBJECTIVE: The aim of this study was to investigate the expression pattern of oncogenes, antimicrobial peptides, and genes involved in inflammation in leukoplakia of the oral cavity compared with healthy gingiva. STUDY DESIGN: Biopsies of healthy gingiva (n=20) and leukoplakia (n=20), were obtained

  9. K-ras oncogene mutations in sporadic colorectal cancer in The Netherlands Cohort Study

    NARCIS (Netherlands)

    Brink, M.; Goeij, A.F.P.M. de; Weijenberg, M.P.; Roemen, G.M.J.M.; Lentjes, M.H.F.M.; Pachen, M.M.M.; Smits, K.M.; Bruïne, A.P. de; Goldbohm, R.A.; Brandt, P.A. van den

    2003-01-01

    Activation of K-ras oncogene has been implicated in colorectal carcinogenesis, being mutated in 30-60% of the adenocarcinomas. In this study, 737 incident colorectal cancer (CRC) patients, originating from 120 852 men and women (55-69 years at baseline) participating in the Netherlands Cohort Study

  10. For better or for worse : the role of Pim oncogenes in tumorigenesis

    NARCIS (Netherlands)

    Nawijn, Martijn C.; Alendar, Andrej; Berns, Anton

    2011-01-01

    Pim oncogenes are overexpressed in a wide range of tumours from a haematological and epithelial origin. Pim genes encode serine/threonine kinases that have been shown to counteract the increased sensitivity to apoptosis induction that is associated with MYC-driven tumorigenesis. Recently, considerab

  11. Skin carcinomas in organ-transplant recipients : from early oncogenic events to therapy

    NARCIS (Netherlands)

    Graaf, Ymke Grete Leontien de

    2008-01-01

    Skin carcinomas develop at a high rate in organ-transplant recipients who are kept on immune suppressive drugs to prevent graft rejection. The present study dealt with a broad range of aspects of this elevated carcinoma risk, starting from the earliest oncogenic events to the ultimate therapy.

  12. Skin carcinomas in organ-transplant recipients : from early oncogenic events to therapy

    NARCIS (Netherlands)

    Graaf, Ymke Grete Leontien de

    2008-01-01

    Skin carcinomas develop at a high rate in organ-transplant recipients who are kept on immune suppressive drugs to prevent graft rejection. The present study dealt with a broad range of aspects of this elevated carcinoma risk, starting from the earliest oncogenic events to the ultimate therapy. Advan

  13. Gene expression of oncogenes, antimicrobial peptides, and cytokines in the development of oral leukoplakia.

    NARCIS (Netherlands)

    Wenghoefer, M.; Pantelis, A.; Najafi, T.; Deschner, J.; Allam, J.P.; Novak, N.; Reich, R.; Martini, M.; Berge, S.J.; Fischer, H.P.; Jepsen, S.; Winter, J.

    2010-01-01

    OBJECTIVE: The aim of this study was to investigate the expression pattern of oncogenes, antimicrobial peptides, and genes involved in inflammation in leukoplakia of the oral cavity compared with healthy gingiva. STUDY DESIGN: Biopsies of healthy gingiva (n=20) and leukoplakia (n=20), were obtained

  14. Targeted expression of oncogenic K-ras in intestinal epithelium causes spontaneous tumorigenesis in mice

    NARCIS (Netherlands)

    Janssen, KP; El Marjou, F; Pinto, D; Sastre, X; Rouillard, D; Fouquet, C; Soussi, T; Louvard, D; Robine, S

    2002-01-01

    Background & Aims: Ras oncoproteins are mutated in about 50% of human colorectal cancers, but their precise role in tumor initiation or progression is still unclear. Methods: This study presents transgenic mice that express K-ras(V12G), the most frequent oncogenic mutation in human tumors, under con

  15. Complex Oncogenic Translocations with Gene Amplification are Initiated by Specific DNA Breaks in Lymphocytes

    OpenAIRE

    2009-01-01

    Chromosomal instability is a hallmark of many tumor types. Complex chromosomal rearrangements with associated gene amplification, known as complicons, characterize many hematologic and solid cancers. While chromosomal aberrations, including complicons, are useful diagnostic and prognostic cancer markers, their molecular origins are not known. Although accumulating evidence has implicated DNA double strand break repair in suppression of oncogenic genome instability, the genomic elements requir...

  16. A single oncogenic enhancer rearrangement causes concomitant EVI1 and GATA2 deregulation in leukemia

    NARCIS (Netherlands)

    Gröschel, Stefan; Sanders, Mathijs A; Hoogenboezem, Remco; de Wit, Elzo; Bouwman, Britta A M; Erpelinck, Claudia; van der Velden, Vincent H J; Havermans, Marije; Avellino, Roberto; van Lom, Kirsten; Rombouts, Elwin J; van Duin, Mark; Döhner, Konstanze; Beverloo, H Berna; Bradner, James E; Döhner, Hartmut; Löwenberg, Bob; Valk, Peter J M; Bindels, Eric M J; de Laat, Wouter; Delwel, Ruud

    2014-01-01

    Chromosomal rearrangements without gene fusions have been implicated in leukemogenesis by causing deregulation of proto-oncogenes via relocation of cryptic regulatory DNA elements. AML with inv(3)/t(3;3) is associated with aberrant expression of the stem-cell regulator EVI1. Applying functional geno

  17. Analyses of domains and domain fusions in human proto-oncogenes

    Directory of Open Access Journals (Sweden)

    Wan Ping

    2009-03-01

    Full Text Available Abstract Background Understanding the constituent domains of oncogenes, their origins and their fusions may shed new light about the initiation and the development of cancers. Results We have developed a computational pipeline for identification of functional domains of human genes, prediction of the origins of these domains and their major fusion events during evolution through integration of existing and new tools of our own. An application of the pipeline to 124 well-characterized human oncogenes has led to the identification of a collection of domains and domain pairs that occur substantially more frequently in oncogenes than in human genes on average. Most of these enriched domains and domain pairs are related to tyrosine kinase activities. In addition, our analyses indicate that a substantial portion of the domain-fusion events of oncogenes took place in metazoans during evolution. Conclusion We expect that the computational pipeline for domain identification, domain origin and domain fusion prediction will prove to be useful for studying other groups of genes.

  18. Repeat-element driven activation of proto-oncogenes in human malignancies.

    Science.gov (United States)

    Lamprecht, Björn; Bonifer, Constanze; Mathas, Stephan

    2010-11-01

    Recent data demonstrated that the aberrant activity of endogenous repetitive elements of the DNA in humans can drive the expression of proto-oncogenes. This article summarizes these results and gives an outlook on the impact of these findings on the pathogenesis and therapy of human cancer.

  19. Human papillomavirus: E6 and E7 oncogenes.

    Science.gov (United States)

    Boulet, Gaëlle; Horvath, Caroline; Vanden Broeck, Davy; Sahebali, Shaira; Bogers, Johannes

    2007-01-01

    The recognition of a causal relationship between human papillomaviruses and cancer almost 30 years ago led to a rapid expansion of knowledge in the field, resulting in the description of the main mediators of HPV-induced carcinogenesis, the viral proteins E6 and E7. These oncoproteins show a remarkable pleiotropism in binding host-cell proteins, with the tumour suppressor genes p53 and pRb as their major targets. These interactions induce proliferation, immortalization and malignant transformation of infected cells. The link between HPV and cervical cancer led to the development of molecular methods, often based on the detection of E6 and E7, for screening and diagnosis. Therapeutic vaccines and gene therapy are primarily directed at E6 and E7. Although prophylactic vaccines are available, further understanding of the viral life cycle and the mechanisms underlying HPV-induced oncogenesis is necessary to face the many challenges in the field of HPV and cancer.

  20. HER-2/neu oncogene amplification and chromosome 17 aneusomy in endometrial carcinoma: correlation with oncoprotein expression and conventional pathological parameters.

    Science.gov (United States)

    Cianciulli, A M; Guadagni, F; Marzano, R; Benevolo, M; Merola, R; Giannarelli, D; Marandino, F; Vocaturo, G; Mariani, L; Mottolese, M

    2003-06-01

    The objective of the present study was to evaluate the correlation between HER-2 gene amplification and HER-2 protein overexpression in endometrial carcinoma using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). We also analyzed chromosome 17 aneusomy and the association between these biological parameters and conventional clinicopathological variables. FISH analysis was performed on 73 selected paraffin-embedded sections from endometrial carcinomas which previously had HER-2 status determined immunohistochemically using monoclonal antibodies (MoAb) 300G9 and CB11. Using a ratio of more than two oncogene signals/centromere to indicate amplification, a total of 42 out of the 73 endometrial tumors included in this study resulted positive by FISH where as protein overexpression was identified in 29 out of 73 with a concordance rate of 74.3%. However, when the mean signals/centromere per nucleus increased (ratio > 4 2 4 < or = 5 when we grouped the amplified cases on the basis of HER-2:CEP17 ratio. In conclusion, molecular characteristics provide objective data that may be useful in predicting prognosis in patients with endometrial cancer.

  1. BAF53 Forms Distinct Nuclear Complexes and Functions as a Critical c-Myc-Interacting Nuclear Cofactor for Oncogenic Transformation

    Science.gov (United States)

    Park, Jeonghyeon; Wood, Marcelo A.; Cole, Michael D.

    2002-01-01

    The c-Myc oncoprotein functions as a transcription factor that can transform normal cells into tumor cells, as well as playing a direct role in normal cell proliferation. The c-Myc protein transactivates cellular promoters by recruiting nuclear cofactors to chromosomal sites through an N-terminal transactivation domain. We have previously reported the identification and functional characterization of four different c-Myc cofactors: TRRAP, hGCN5, TIP49, and TIP48. Here we present the identification and characterization of the actin-related protein BAF53 as a c-Myc-interacting nuclear cofactor that forms distinct nuclear complexes. In addition to the human SWI/SNF-related BAF complex, BAF53 forms a complex with TIP49 and TIP48 and a separate biochemically distinct complex containing TRRAP and a histone acetyltransferase which does not contain TIP60. Using deletion mutants of BAF53, we show that BAF53 is critical for c-Myc oncogenic activity. Our results indicate that BAF53 plays a functional role in c-Myc-interacting nuclear complexes. PMID:11839798

  2. Genome-wide association between YAP/TAZ/TEAD and AP-1 at enhancers drives oncogenic growth.

    Science.gov (United States)

    Zanconato, Francesca; Forcato, Mattia; Battilana, Giusy; Azzolin, Luca; Quaranta, Erika; Bodega, Beatrice; Rosato, Antonio; Bicciato, Silvio; Cordenonsi, Michelangelo; Piccolo, Stefano

    2015-09-01

    YAP/TAZ are nuclear effectors of the Hippo pathway regulating organ growth and tumorigenesis. Yet, their function as transcriptional regulators remains underinvestigated. By ChIP-seq analyses in breast cancer cells, we discovered that the YAP/TAZ transcriptional response is pervasively mediated by a dual element: TEAD factors, through which YAP/TAZ bind to DNA, co-occupying chromatin with activator protein-1 (AP-1, dimer of JUN and FOS proteins) at composite cis-regulatory elements harbouring both TEAD and AP-1 motifs. YAP/TAZ/TEAD and AP-1 form a complex that synergistically activates target genes directly involved in the control of S-phase entry and mitosis. This control occurs almost exclusively from distal enhancers that contact target promoters through chromatin looping. YAP/TAZ-induced oncogenic growth is strongly enhanced by gain of AP-1 and severely blunted by its loss. Conversely, AP-1-promoted skin tumorigenesis is prevented in YAP/TAZ conditional knockout mice. This work highlights a new layer of signalling integration, feeding on YAP/TAZ function at the chromatin level.

  3. Defining RNA–Small Molecule Affinity Landscapes Enables Design of a Small Molecule Inhibitor of an Oncogenic Noncoding RNA

    Science.gov (United States)

    2017-01-01

    RNA drug targets are pervasive in cells, but methods to design small molecules that target them are sparse. Herein, we report a general approach to score the affinity and selectivity of RNA motif–small molecule interactions identified via selection. Named High Throughput Structure–Activity Relationships Through Sequencing (HiT-StARTS), HiT-StARTS is statistical in nature and compares input nucleic acid sequences to selected library members that bind a ligand via high throughput sequencing. The approach allowed facile definition of the fitness landscape of hundreds of thousands of RNA motif–small molecule binding partners. These results were mined against folded RNAs in the human transcriptome and identified an avid interaction between a small molecule and the Dicer nuclease-processing site in the oncogenic microRNA (miR)-18a hairpin precursor, which is a member of the miR-17-92 cluster. Application of the small molecule, Targapremir-18a, to prostate cancer cells inhibited production of miR-18a from the cluster, de-repressed serine/threonine protein kinase 4 protein (STK4), and triggered apoptosis. Profiling the cellular targets of Targapremir-18a via Chemical Cross-Linking and Isolation by Pull Down (Chem-CLIP), a covalent small molecule–RNA cellular profiling approach, and other studies showed specific binding of the compound to the miR-18a precursor, revealing broadly applicable factors that govern small molecule drugging of noncoding RNAs.

  4. HOXB7: An Oncogenic Gene in Breast Cancer

    Science.gov (United States)

    2005-05-01

    G1-type aberrations were examined at metaphase. All categories of asymmetric chromosome aberrations were scored: dicentrics , centric rings...transfected with HOXB7 survive better after induction of DNA DSB with fewer chromosomal abnormalities following exposure to gamma radiation. HOXB7...autosomal chromosomes , and a newly discovered cluster on the X chromosome , RHOX (McLean et al, 2005). The functions of homeodomain-containing proteins

  5. PKC Epsilon: A Novel Oncogenic Player in Prostate Cancer

    Science.gov (United States)

    2013-09-01

    tyrosine-kinase and G-protein-coupled receptor ( GPCR ) activation [3]. Despite our extensive knowledge on PKC regulation and function, the specific roles for...the receptor. LNCaP cells were stimulate with TNFα (25 ng/ml) for 5 min and subjected to IP with an anti-TNFR-I antibody . Western blots were probed...with phosphoamino acid antibodies . It was observed that TNFα treatment mediates the phosphorylation on serine and threonine residues but not on

  6. The TEAD Family and Its Oncogenic Role in Promoting Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Yuhang Zhou

    2016-01-01

    Full Text Available The TEAD family of transcription factors is necessary for developmental processes. The family members contain a TEA domain for the binding with DNA elements and a transactivation domain for the interaction with transcription coactivators. TEAD proteins are required for the participation of coactivators to transmit the signal of pathways for the downstream signaling processes. TEADs also play an important role in tumor initiation and facilitate cancer progression via activating a series of progression-inducing genes, such as CTGF, Cyr61, Myc and Gli2. Recent studies have highlighted that TEADs, together with their coactivators, promote or even act as the crucial parts in the development of various malignancies, such as liver, ovarian, breast and prostate cancers. Furthermore, TEADs are proposed to be useful prognostic biomarkers due to the ideal correlation between high expression and clinicopathological parameters in gastric, breast, ovarian and prostate cancers. In this review, we summarize the functional role of TEAD proteins in tumorigenesis and discuss the key role of TEAD transcription factors in the linking of signal cascade transductions. Improved knowledge of the TEAD proteins will be helpful for deep understanding of the molecular mechanisms of tumorigenesis and identifying ideal predictive or prognostic biomarkers, even providing clinical translation for anticancer therapy in human cancers.

  7. The TEAD Family and Its Oncogenic Role in Promoting Tumorigenesis.

    Science.gov (United States)

    Zhou, Yuhang; Huang, Tingting; Cheng, Alfred S L; Yu, Jun; Kang, Wei; To, Ka Fai

    2016-01-21

    The TEAD family of transcription factors is necessary for developmental processes. The family members contain a TEA domain for the binding with DNA elements and a transactivation domain for the interaction with transcription coactivators. TEAD proteins are required for the participation of coactivators to transmit the signal of pathways for the downstream signaling processes. TEADs also play an important role in tumor initiation and facilitate cancer progression via activating a series of progression-inducing genes, such as CTGF, Cyr61, Myc and Gli2. Recent studies have highlighted that TEADs, together with their coactivators, promote or even act as the crucial parts in the development of various malignancies, such as liver, ovarian, breast and prostate cancers. Furthermore, TEADs are proposed to be useful prognostic biomarkers due to the ideal correlation between high expression and clinicopathological parameters in gastric, breast, ovarian and prostate cancers. In this review, we summarize the functional role of TEAD proteins in tumorigenesis and discuss the key role of TEAD transcription factors in the linking of signal cascade transductions. Improved knowledge of the TEAD proteins will be helpful for deep understanding of the molecular mechanisms of tumorigenesis and identifying ideal predictive or prognostic biomarkers, even providing clinical translation for anticancer therapy in human cancers.

  8. 53BP1 is limiting for NHEJ repair in ATM-deficient model systems that are subjected to oncogenic stress or radiation.

    Science.gov (United States)

    Rybanska-Spaeder, Ivana; Reynolds, Taylor L; Chou, Jeremy; Prakash, Mansi; Jefferson, Tameca; Huso, David L; Desiderio, Stephen; Franco, Sonia

    2013-10-01

    The DNA damage response (DDR) factors ataxia telangiectasia mutated (ATM) and p53 binding protein 1 (53BP1) function as tumor suppressors in humans and mice, but the significance of their mutual interaction to the suppression of oncogenic translocations in vivo has not been investigated. To address this question, the phenotypes of compound mutant mice lacking 53BP1 and ATM (Trp53bp1(-/-)/Atm(-/-)), relative to single mutants, were examined. These analyses revealed that loss of 53BP1 markedly decreased the latency of T-lineage lymphomas driven by RAG-dependent oncogenic translocations in Atm(-/-) mice (average survival, 14 and 23 weeks for Trp53bp1(-/-)/Atm(-/-) and Atm(-/-) mice, respectively). Mechanistically, 53BP1 deficiency aggravated the deleterious effect of ATM deficiency on nonhomologous end-joining (NHEJ)-mediated double-strand break repair. Analysis of V(D)J recombinase-mediated coding joints and signal joints in Trp53bp1(-/-)/Atm(-/-) primary thymocytes is, however, consistent with canonical NHEJ-mediated repair. Together, these findings indicate that the greater NHEJ defect in the double mutant mice resulted from decreased efficiency of rejoining rather than switching to an alternative NHEJ-mediated repair mechanism. Complementary analyses of irradiated primary cells indicated that defects in cell-cycle checkpoints subsequently function to amplify the NHEJ defect, resulting in more frequent chromosomal breaks and translocations in double mutant cells throughout the cell cycle. Finally, it was determined that 53BP1 is dispensable for the formation of RAG-mediated hybrid joints in Atm(-/-) thymocytes but is required to suppress large deletions in a subset of hybrid joints. The current study uncovers novel ATM-independent functions for 53BP1 in the suppression of oncogenic translocations and in radioprotection.

  9. Oncogenic mutations weaken the interactions that stabilize the p110α-p85α heterodimer in phosphatidylinositol 3-kinase α.

    Science.gov (United States)

    Echeverria, Ignacia; Liu, Yunlong; Gabelli, Sandra B; Amzel, L Mario

    2015-09-01

    Phosphatidylinositol 3-kinase (PI3K) α is a heterodimeric lipid kinase that catalyzes the conversion of phosphoinositol-4,5-bisphosphate to phosphoinositol-3,4,5-trisphosphate. The PI3Kα signaling pathway plays an important role in cell growth, proliferation, and survival. This pathway is activated in numerous cancers, where the PI3KCA gene, which encodes for the p110α PI3Kα subunit, is mutated. Its mutation often results in gain of enzymatic activity; however, the mechanism of activation by oncogenic mutations remains unknown. Here, using computational methods, we show that oncogenic mutations that are far from the catalytic site and increase the enzymatic affinity destabilize the p110α-p85α dimer. By affecting the dynamics of the protein, these mutations favor the conformations that reduce the autoinhibitory effect of the p85α nSH2 domain. For example, we determined that, in all of the mutants, the nSH2 domain shows increased positional heterogeneity as compared with the wild-type, as demonstrated by changes in the fluctuation profiles computed by normal mode analysis of coarse-grained elastic network models. Analysis of the interdomain interactions of the wild-type and mutants at the p110α-p85α interface obtained with molecular dynamics simulations suggest that all of the tumor-associated mutations effectively weaken the interactions between p110α and p85α by disrupting key stabilizing interactions. These findings have important implications for understanding how oncogenic mutations change the conformational multiplicity of PI3Kα and lead to increased enzymatic activity. This mechanism may apply to other enzymes and/or macromolecular complexes that play a key role in cell signaling.

  10. Induction of human microsomal prostaglandin E synthase 1 by activated oncogene RhoA GTPase in A549 human epithelial cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hye Jin [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Lee, Dong-Hyung [Department of Obstetrics and Gynecology, Medical Research Institute, Pusan National University, Busan (Korea, Republic of); Park, Seong-Hwan; Kim, Juil; Do, Kee Hun [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); An, Tae Jin; Ahn, Young Sup; Park, Chung Berm [Department of Herbal Crop Research, NIHHS, RDA, Eumseong (Korea, Republic of); Moon, Yuseok, E-mail: moon@pnu.edu [Laboratory of Systems Mucosal Biomodulation, Department of Microbiology and Immunology, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Medical Research Institute and Research Institute for Basic Sciences, Pusan National University, Busan (Korea, Republic of)

    2011-09-30

    Highlights: {yields} As a target of oncogene RhoA-linked signal, a prostaglandin metabolism is assessed. {yields} RhoA activation increases PGE{sub 2} levels and its metabolic enzyme mPGES-1. {yields} RhoA-activated NF-{kappa}B and EGR-1 are positively involved in mPGES-1 induction. -- Abstract: Oncogenic RhoA GTPase has been investigated as a mediator of pro-inflammatory responses and aggressive carcinogenesis. Among the various targets of RhoA-linked signals, pro-inflammatory prostaglandin E{sub 2} (PGE{sub 2}), a major prostaglandin metabolite, was assessed in epithelial cancer cells. RhoA activation increased PGE{sub 2} levels and gene expression of the rate-limiting PGE{sub 2} producing enzymes, cyclooxygenase-2 and microsomal prostaglandin E synthase 1 (mPGES-1). In particular, human mPGES-1 was induced by RhoA via transcriptional activation in control and interleukin (IL)-1{beta}-activated cancer cells. To address the involvement of potent signaling pathways in RhoA-activated mPGES-1 induction, various signaling inhibitors were screened for their effects on mPGES-1 promoter activity. RhoA activation enhanced basal and IL-1{beta}-mediated phosphorylated nuclear factor-{kappa}B and extracellular signal-regulated kinase1/2 proteins, all of which were positively involved in RhoA-induced gene expression of mPGES-1. As one potent down-stream transcription factor of ERK1/2 signals, early growth response gene 1 product also mediated RhoA-induced gene expression of mPGES-1 by enhancing transcriptional activity. Since oncogene-triggered PGE{sub 2} production is a critical modulator of epithelial tumor cells, RhoA-associated mPGES-1 represents a promising chemo-preventive or therapeutic target for epithelial inflammation and its associated cancers.

  11. Genome-wide screening for genetic alterations in esophageal cancer by aCGH identifies 11q13 amplification oncogenes associated with nodal metastasis.

    Directory of Open Access Journals (Sweden)

    Jianming Ying

    Full Text Available BACKGROUND: Esophageal squamous cell carcinoma (ESCC is highly prevalent in China and other Asian countries, as a major cause of cancer-related mortality. ESCC displays complex chromosomal abnormalities, including multiple structural and numerical aberrations. Chromosomal abnormalities, such as recurrent amplifications and homozygous deletions, directly contribute to tumorigenesis through altering the expression of key oncogenes and tumor suppressor genes. METHODOLOGY/PRINCIPLE FINDINGS: To understand the role of genetic alterations in ESCC pathogenesis and identify critical amplification/deletion targets, we performed genome-wide 1-Mb array comparative genomic hybridization (aCGH analysis for 10 commonly used ESCC cell lines. Recurrent chromosomal gains were frequently detected on 3q26-27, 5p15-14, 8p12, 8p22-24, 11q13, 13q21-31, 18p11 and 20q11-13, with frequent losses also found on 8p23-22, 11q22, 14q32 and 18q11-23. Gain of 11q13.3-13.4 was the most frequent alteration in ESCC. Within this region, CCND1 oncogene was identified with high level of amplification and overexpression in ESCC, while FGF19 and SHANK2 was also remarkably over-expressed. Moreover, a high concordance (91.5% of gene amplification and protein overexpression of CCND1 was observed in primary ESCC tumors. CCND1 amplification/overexpression was also significantly correlated with the lymph node metastasis of ESCC. CONCLUSION: These findings suggest that genomic gain of 11q13 is the major mechanism contributing to the amplification. Novel oncogenes identified within the 11q13 amplicon including FGF19 and SHANK2 may play important roles in ESCC tumorigenesis.

  12. The BTB-zinc finger transcription factor abrupt acts as an epithelial oncogene in Drosophila melanogaster through maintaining a progenitor-like cell state.

    Directory of Open Access Journals (Sweden)

    Nezaket Turkel

    Full Text Available The capacity of tumour cells to maintain continual overgrowth potential has been linked to the commandeering of normal self-renewal pathways. Using an epithelial cancer model in Drosophila melanogaster, we carried out an overexpression screen for oncogenes capable of cooperating with the loss of the epithelial apico-basal cell polarity regulator, scribbled (scrib, and identified the cell fate regulator, Abrupt, a BTB-zinc finger protein. Abrupt overexpression alone is insufficient to transform cells, but in cooperation with scrib loss of function, Abrupt promotes the formation of massive tumours in the eye/antennal disc. The steroid hormone receptor coactivator, Taiman (a homologue of SRC3/AIB1, is known to associate with Abrupt, and Taiman overexpression also drives tumour formation in cooperation with the loss of Scrib. Expression arrays and ChIP-Seq indicates that Abrupt overexpression represses a large number of genes, including steroid hormone-response genes and multiple cell fate regulators, thereby maintaining cells within an epithelial progenitor-like state. The progenitor-like state is characterised by the failure to express the conserved Eyes absent/Dachshund regulatory complex in the eye disc, and in the antennal disc by the failure to express cell fate regulators that define the temporal elaboration of the appendage along the proximo-distal axis downstream of Distalless. Loss of scrib promotes cooperation with Abrupt through impaired Hippo signalling, which is required and sufficient for cooperative overgrowth with Abrupt, and JNK (Jun kinase signalling, which is required for tumour cell migration/invasion but not overgrowth. These results thus identify a novel cooperating oncogene, identify mammalian family members of which are also known oncogenes, and demonstrate that epithelial tumours in Drosophila can be characterised by the maintenance of a progenitor-like state.

  13. The BTB-zinc Finger Transcription Factor Abrupt Acts as an Epithelial Oncogene in Drosophila melanogaster through Maintaining a Progenitor-like Cell State

    Science.gov (United States)

    Turkel, Nezaket; Sahota, Virender K.; Bolden, Jessica E.; Goulding, Karen R.; Doggett, Karen; Willoughby, Lee F.; Blanco, Enrique; Martin-Blanco, Enrique; Corominas, Montserrat; Ellul, Jason; Aigaki, Toshiro; Richardson, Helena E.; Brumby, Anthony M.

    2013-01-01

    The capacity of tumour cells to maintain continual overgrowth potential has been linked to the commandeering of normal self-renewal pathways. Using an epithelial cancer model in Drosophila melanogaster, we carried out an overexpression screen for oncogenes capable of cooperating with the loss of the epithelial apico-basal cell polarity regulator, scribbled (scrib), and identified the cell fate regulator, Abrupt, a BTB-zinc finger protein. Abrupt overexpression alone is insufficient to transform cells, but in cooperation with scrib loss of function, Abrupt promotes the formation of massive tumours in the eye/antennal disc. The steroid hormone receptor coactivator, Taiman (a homologue of SRC3/AIB1), is known to associate with Abrupt, and Taiman overexpression also drives tumour formation in cooperation with the loss of Scrib. Expression arrays and ChIP-Seq indicates that Abrupt overexpression represses a large number of genes, including steroid hormone-response genes and multiple cell fate regulators, thereby maintaining cells within an epithelial progenitor-like state. The progenitor-like state is characterised by the failure to express the conserved Eyes absent/Dachshund regulatory complex in the eye disc, and in the antennal disc by the failure to express cell fate regulators that define the temporal elaboration of the appendage along the proximo-distal axis downstream of Distalless. Loss of scrib promotes cooperation with Abrupt through impaired Hippo signalling, which is required and sufficient for cooperative overgrowth with Abrupt, and JNK (Jun kinase) signalling, which is required for tumour cell migration/invasion but not overgrowth. These results thus identify a novel cooperating oncogene, identify mammalian family members of which are also known oncogenes, and demonstrate that epithelial tumours in Drosophila can be characterised by the maintenance of a progenitor-like state. PMID:23874226

  14. Analysis of multiple sarcoma expression datasets: implications for classification, oncogenic pathway activation and chemotherapy resistance.

    Directory of Open Access Journals (Sweden)

    Panagiotis A Konstantinopoulos

    Full Text Available BACKGROUND: Diagnosis of soft tissue sarcomas (STS is challenging. Many remain unclassified (not-otherwise-specified, NOS or grouped in controversial categories such as malignant fibrous histiocytoma (MFH, with unclear therapeutic value. We analyzed several independent microarray datasets, to identify a predictor, use it to classify unclassifiable sarcomas, and assess oncogenic pathway activation and chemotherapy response. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 5 independent datasets (325 tumor arrays. We developed and validated a predictor, which was used to reclassify MFH and NOS sarcomas. The molecular "match" between MFH and their predicted subtypes was assessed using genome-wide hierarchical clustering and Subclass-Mapping. Findings were validated in 15 paraffin samples profiled on the DASL platform. Bayesian models of oncogenic pathway activation and chemotherapy response were applied to individual STS samples. A 170-gene predictor was developed and independently validated (80-85% accuracy in all datasets. Most MFH and NOS tumors were reclassified as leiomyosarcomas, liposarcomas and fibrosarcomas. "Molecular match" between MFH and their predicted STS subtypes was confirmed both within and across datasets. This classification revealed previously unrecognized tissue differentiation lines (adipocyte, fibroblastic, smooth-muscle and was reproduced in paraffin specimens. Different sarcoma subtypes demonstrated distinct oncogenic pathway activation patterns, and reclassified MFH tumors shared oncogenic pathway activation patterns with their predicted subtypes. These patterns were associated with predicted resistance to chemotherapeutic agents commonly used in sarcomas. CONCLUSIONS/SIGNIFICANCE: STS profiling can aid in diagnosis through a predictor tracking distinct tissue differentiation in unclassified tumors, and in therapeutic management via oncogenic pathway activation and chemotherapy response assessment.

  15. Expression of the proto-oncogenes c-met and c-kit and their ligands, hepatocyte growth factor/scatter factor and stem cell factor, in SCLC cell lines and xenografts

    DEFF Research Database (Denmark)

    Rygaard, K; Nakamura, T; Spang-Thomsen, M

    1993-01-01

    We examined a panel of 25 small cell lung cancer (SCLC) cell lines and nude mouse xenografts for expression of the proto-oncogenes c-met and c-kit, and for expression of the corresponding ligands, hepatocyte growth factor (HGF) (also known as scatter factor (SF)), and stem cell factor (SCF......), respectively. Expression of mRNA was detected by Northern blotting, and c-met and c-kit protein expression was detected by Western blotting and immunocytochemistry. c-met and c-kit mRNA was expressed in 22 of the examined cell lines or xenografts, and coexpression of the two proto-oncogenes was observed in 20...... tumours. Expression of c-met and c-kit protein paralleled in the mRNA expression. HGF/SF mRNA was expressed in two of the examined tumours, and only one of these also expressed the c-met proto-oncogene. SCF mRNA was expressed in 19 of the examined tumours, and in 18 of these coexpression of c-kit and SCF...

  16. Jnk2 effects on tumor development, genetic instability and replicative stress in an oncogene-driven mouse mammary tumor model.

    Directory of Open Access Journals (Sweden)

    Peila Chen

    Full Text Available Oncogenes induce cell proliferation leading to replicative stress, DNA damage and genomic instability. A wide variety of cellular stresses activate c-Jun N-terminal kinase (JNK proteins, but few studies have directly addressed the roles of JNK isoforms in tumor development. Herein, we show that jnk2 knockout mice expressing the Polyoma Middle T Antigen transgene developed mammary tumors earlier and experienced higher tumor multiplicity compared to jnk2 wildtype mice. Lack of jnk2 expression was associated with higher tumor aneuploidy and reduced DNA damage response, as marked by fewer pH2AX and 53BP1 nuclear foci. Comparative genomic hybridization further confirmed increased genomic instability in PyV MT/jnk2-/- tumors. In vitro, PyV MT/jnk2-/- cells underwent replicative stress and cell death as evidenced by lower BrdU incorporation, and sustained chromatin licensing and DNA replication factor 1 (CDT1 and p21(Waf1 protein expression, and phosphorylation of Chk1 after serum stimulation, but this response was not associated with phosphorylation of p53 Ser15. Adenoviral overexpression of CDT1 led to similar differences between jnk2 wildtype and knockout cells. In normal mammary cells undergoing UV induced single stranded DNA breaks, JNK2 localized to RPA (Replication Protein A coated strands indicating that JNK2 responds early to single stranded DNA damage and is critical for subsequent recruitment of DNA repair proteins. Together, these data support that JNK2 prevents replicative stress by coordinating cell cycle progression and DNA damage repair mechanisms.

  17. Structure of human POFUT1, its requirement in ligand-independent oncogenic Notch signaling, and functional effects of Dowling-Degos mutations

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, Brian J.; Zimmerman, Brandon; Egan, Emily D.; Lofgren, Michael; Xu, Xiang; Hesser, Anthony; Blacklow, Stephen C.

    2017-03-17

    Protein O-fucosyltransferase-1 (POFUT1), which transfers fucose residues to acceptor sites on serine and threonine residues of epidermal growth factor-like repeats of recipient proteins, is essential for Notch signal transduction in mammals. Here, we examine the consequences of POFUT1 loss on the oncogenic signaling associated with certain leukemia-associated mutations of human Notch1, report the structures of human POFUT1 in free and GDP-fucose bound states, and assess the effects of Dowling-Degos mutations on human POFUT1 function. CRISPR-mediated knockout of POFUT1 in U2OS cells suppresses both normal Notch1 signaling, and the ligand-independent signaling associated with leukemogenic mutations of Notch1. Normal and oncogenic signaling are rescued by wild-type POFUT1 but rescue is impaired by an active-site R240A mutation. The overall structure of the human enzyme closely resembles that of the Caenorhabditis elegans protein, with an overall backbone RMSD of 0.93 Å, despite primary sequence identity of only 39% in the mature protein. GDP-fucose binding to the human enzyme induces limited backbone conformational movement, though the side chains of R43 and D244 reorient to make direct contact with the fucose moiety in the complex. The reported Dowling-Degos mutations of POFUT1, except for M262T, fail to rescue Notch1 signaling efficiently in the CRISPR-engineered POFUT1-/- background. Together, these studies identify POFUT1 as a potential target for cancers driven by Notch1 mutations and provide a structural roadmap for its inhibition.

  18. In Vivo Imaging-Based Mathematical Modeling Techniques That Enhance the Understanding of Oncogene Addiction in relation to Tumor Growth

    Directory of Open Access Journals (Sweden)

    Chinyere Nwabugwu

    2013-01-01

    Full Text Available The dependence on the overexpression of a single oncogene constitutes an exploitable weakness for molecular targeted therapy. These drugs can produce dramatic tumor regression by targeting the driving oncogene, but relapse often follows. Understanding the complex interactions of the tumor’s multifaceted response to oncogene inactivation is key to tumor regression. It has become clear that a collection of cellular responses lead to regression and that immune-mediated steps are vital to preventing relapse. Our integrative mathematical model includes a variety of cellular response mechanisms of tumors to oncogene inactivation. It allows for correct predictions of the time course of events following oncogene inactivation and their impact on tumor burden. A number of aspects of our mathematical model have proven to be necessary for recapitulating our experimental results. These include a number of heterogeneous tumor cell states since cells following different cellular programs have vastly different fates. Stochastic transitions between these states are necessary to capture the effect of escape from oncogene addiction (i.e., resistance. Finally, delay differential equations were used to accurately model the tumor growth kinetics that we have observed. We use this to model oncogene addiction in MYC-induced lymphoma, osteosarcoma, and hepatocellular carcinoma.

  19. In vivo study on the effects of microcystin extracts on the expression profiles of proto-oncogenes (c-fos, c-jun and c-myc) in liver, kidney and testis of male Wistar rats injected i.v. with toxins.

    Science.gov (United States)

    Li, Huiying; Xie, Ping; Li, Guangyu; Hao, Le; Xiong, Qian

    2009-01-01

    Microcystins (MCs) are a potent liver tumor promoter, possessing potent tumor-promoting activity and weak initiating activity. Proto-oncogenes are known to be involved in the tumor-promoting mechanisms of microcystin-LR. However, few data are available on the effects of MCs on proto-oncogenes in the whole animal. To investigate the effects of MCs on the expression profile of the proto-oncogenes in different organs, male Wistar rats were injected intravenously with microcystin extracts at a dose of 86.7 mug MC-LR eq/kg bw (MC-LR eq, MC-LR equivalents). mRNA levels of three proto-oncogenes c-fos, c-jun and c-myc in liver, kidney and testis were analyzed using quantitative real-time PCR at several time points post-injection. Significant induction of these genes at transcriptional level was observed in the three organs. In addition, the increase of mRNA expression of all three genes was much higher in liver than in kidney and testis. Meanwhile, the protein levels of c-Fos and c-Jun were investigated by western blotting. Both proteins were induced in the three organs. However, elevations of protein levels were much lower than those of mRNA levels. These findings suggest that the expression of c-fos, c-jun and c-myc might be one possible mechanism for the tumor-promoting activity and initiating activity of microcystins.

  20. Evidence of an oncogenic gammaherpesvirus in domestic dogs

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shih-Hung, E-mail: ncku309@gmail.com [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Kozak, Philip J., E-mail: philj@vet.upenn.edu [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Kim, Jessica, E-mail: jesskim820@gmail.com [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Habineza-Ndikuyeze, Georges, E-mail: georgesh@vet.upenn.edu [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Meade, Charles, E-mail: cmeade@vet.upenn.edu [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Gaurnier-Hausser, Anita, E-mail: anitag@vet.upenn.edu [Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, 335 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Patel, Reema, E-mail: rtpatel@vet.upenn.edu [Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, 315 Hill Pavilion, 380 South University Avenue, Philadelphia, PA 19104-6010 (United States); Robertson, Erle, E-mail: erle@mail.med.upenn.edu [Department of Microbiology, and Abramson Comprehensive Cancer Center, Tumor Virology Program, University of Pennsylvania, 202A Johnson Pavilion, 3610 Hamilton Walk, Philadelphia, PA 19104-6076 (United States); and others

    2012-06-05

    In humans, chronic infection with the gammaherpesvirus Epstein-Barr virus is usually asymptomatic; however some infected individuals develop hematological and epithelial malignancies. The exact role of EBV in lymphomagenesis is poorly understood partly because of the lack of clinically relevant animal models. Here we report the detection of serological responses against EBV capsid antigens in healthy dogs and dogs with spontaneous lymphoma and that dogs with the highest antibody titers have B cell lymphoma. Moreover, we demonstrate the presence of EBV-like viral DNA and RNA sequences and Latent Membrane Protein-1 in malignant lymph nodes of dogs with lymphoma. Finally, electron microscopy of canine malignant B cells revealed the presence of classic herpesvirus particles. These findings suggest that dogs can be naturally infected with an EBV-like gammaherpesvirus that may contribute to lymphomagenesis and that dogs might represent a spontaneous model to investigate environmental and genetic factors that influence gammaherpesvirus-associated lymphomagenesis in humans.

  1. Preventing and exploiting the oncogenic potential of integrating gene vectors.

    Science.gov (United States)

    Modlich, Ute; Baum, Christopher

    2009-04-01

    Gene therapy requires efficient gene delivery to cure or prevent disease by modifying the genome of somatic cells. However, gene vectors, which insert themselves into the host genome in order to achieve persistent protein expression, can trigger oncogenesis by upregulating cellular protooncogenes. This adverse event, known as insertional mutagenesis, has become a major hurdle in the field. Vectors developed on the basis of lentiviruses are considered to be less genotoxic than the hitherto used gamma-retroviral vectors. For their report in this issue of the JCI, Montini et al. utilized a tumor-prone mouse model to identify the genetic determinants of insertional mutagenesis (see the related article beginning on page 964). They report that the lentiviral integration pattern and additional improvements in vector design reduce the genotoxic risk. These findings will inform future vector design with the goal of limiting genotoxicity for gene therapy or increasing genotoxicity for protooncogene discovery.

  2. STAT1 is phosphorylated and downregulated by the oncogenic tyrosine kinase NPM-ALK in ALK-positive anaplastic large-cell lymphoma.

    Science.gov (United States)

    Wu, Chengsheng; Molavi, Ommoleila; Zhang, Haifeng; Gupta, Nidhi; Alshareef, Abdulraheem; Bone, Kathleen M; Gopal, Keshav; Wu, Fang; Lewis, Jamie T; Douglas, Donna N; Kneteman, Norman M; Lai, Raymond

    2015-07-16

    The tumorigenicity of most cases of ALK-positive anaplastic large-cell lymphoma (ALK+ ALCL) is driven by the oncogenic fusion protein NPM-ALK in a STAT3-dependent manner. Because it has been shown that STAT3 can be inhibited by STAT1 in some experimental models, we hypothesized that the STAT1 signaling pathway is defective in ALK+ ALCL, thereby leaving the STAT3 signaling unchecked. Compared with normal T cells, ALK+ ALCL tumors consistently expressed a low level of STAT1. Inhibition of the ubiquitin-proteasome pathway appreciably increased STAT1 expression in ALK+ ALCL cells. Furthermore, we found evidence that NPM-ALK binds to and phosphorylates STAT1, thereby promoting its proteasomal degradation in a STAT3-dependent manner. If restored, STAT1 is functionally intact in ALK+ ALCL cells, because it effectively upregulated interferon-γ, induced apoptosis/cell-cycle arrest, potentiated the inhibitory effects of doxorubicin, and suppressed tumor growth in vivo. STAT1 interfered with the STAT3 signaling by decreasing STAT3 transcriptional activity/DNA binding and its homodimerization. The importance of the STAT1/STAT3 functional interaction was further highlighted by the observation that short interfering RNA knockdown of STAT1 significantly decreased apoptosis induced by STAT3 inhibition. Thus, STAT1 is a tumor suppressor in ALK+ ALCL. Phosphorylation and downregulation of STAT1 by NPM-ALK represent other mechanisms by which this oncogenic tyrosine kinase promotes tumorigenesis.

  3. Kit K641E oncogene up-regulates Sprouty homolog 4 and Trophoblast glycoprotein in interstitial cells of Cajal in a murine model of gastrointestinal stromal tumours

    Science.gov (United States)

    Gromova, Petra; Ralea, Sebastian; Lefort, Anne; Libert, Frédérick; Rubin, Brian P; Erneux, Christophe; Vanderwinden, Jean-Marie

    2009-01-01

    Gastrointestinal stromal tumours (GIST) are thought to derive from the interstitial cells of Cajal (ICC) or an ICC precursor. Oncogenic mutations of the receptor tyrosine kinase KIT are present in most GIST. KIT K642E was originally identified in sporadic GIST and later found in the germ line of a familial GIST cohort. A mouse model harbouring a germline Kit K641E mutant was created to model familial GIST. The expression profile was investigated in the gastric antrum of the KitK641E murine GIST model by microarray, quantitative PCR and immunofluorescence. Gja1/Cx43, Gpc6, Gpr133, Pacrg, Pde3a, Prkar2b, Prkcq/Pkce, Rasd2, Spry4 and Tpbg/5T4 were found to be up-regulated. The proteins encoded by Gja1/Cx43, Pde3a, Prkcq/Pkce were localized in Kit-ir ICC in wild-type and KitK641E animals while Spry4 and Tpbg/5T4 were detected in Kit-ir cells only in KitK641E, but not in KitWT/WT animals. Most up-regulated genes in this mouse model belong to the gene expression profile of human GIST but also to the profile of normal Kit+ ICC in the mouse small intestine. Spry4 and Tpbg/5T4 may represent candidates for targeted therapeutic approaches in GIST with oncogenic KIT mutations. PMID:19453770

  4. 5-aza-2'-deoxycytidine (DAC) treatment downregulates the HPV E6 and E7 oncogene expression and blocks neoplastic growth of HPV-associated cancer cells.

    Science.gov (United States)

    Stich, Maximilian; Ganss, Lennard; Puschhof, Jens; Prigge, Elena-Sophie; Reuschenbach, Miriam; Guiterrez, Ana; Vinokurova, Svetlana; von Knebel Doeberitz, Magnus

    2016-07-16

    High-risk human papillomaviruses (hr HPVs) may cause various human cancers and associated premalignant lesions. Transformation of the host cells is triggered by overexpression of the viral oncogenes E6 and E7 that deregulate the cell cycle and induce chromosomal instability. This process is accompanied by hypermethylation of distinct CpG sites resulting in silencing of tumor suppressor genes, inhibition of the viral E2 mediated control of E6 and E7 transcription as well as deregulated expression of host cell microRNAs. Therefore, we hypothesized that treatment with demethylating agents might restore those regulatory mechanisms. Here we show that treatment with 5-aza-2'-deoxycytidine (DAC) strongly decreases the expression of E6 and E7 in a panel of HPV-transformed cervical cancer and head and neck squamous cell carcinoma cell lines. Reduction of E6 and E7 further resulted in increased target protein levels including p53 and p21 reducing the proliferation rates and colony formation abilities of the treated cell lines. Moreover, DAC treatment led to enhanced expression of tumor the suppressive miRNA-375 that targets and degrades E6 and E7 transcripts. Therefore, we suggest that DAC treatment of HPV-associated cancers and respective precursor lesions may constitute a targeted approach to subvert HPV oncogene functions that deserves testing in clinical trials.

  5. Oncogenic HPV among HIV infected female population in West Bengal, India

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    Sengupta Sharmila

    2011-03-01

    Full Text Available Abstract Background Prevalence of both cervical cancer and Human Immunodeficiency Virus (HIV infection are very high in India. Natural history of Human Papilloma Virus (HPV infection is known to be altered in HIV positive women and there is an increased possibility of persistence of HPV infections in this population. Therefore, this study was conducted to understand the epidemiology and circulating genotypes of oncogenic HPV among HIV positive and negative female population in West Bengal, India. Methods In this hospital-based cross-sectional study, 93 known HIV positive females attending a pre-ART registration clinic and 1106 HIV negative females attending a Reproductive and Child Health Care Clinic were subjected to study. Cervical cell samples collected from the study population were tested for the presence of HPV 16, 18 using specific primers. Roche PCR assay was used to detect other specific HPV genotypes in the cervical cells specimens of HIV positive cases only. Results Prevalence of HPV 16, 18 among HIV positive females (32.2%; n = 30 was higher than HIV negative females (9.1%; n = 101. About 53% (23/43 of cases with oncogenic HPV were infected with genotypes other than 16, 18 either as single/multiple infections. HPV 18 and HPV 16 were the predominant genotypes among HIV positive and HIV negative subjects respectively. Oncogenic HPV was not found to be associated with age and duration of sexual exposure. But the presence of HIV was found to a statistically significant predictor oncogenic HPV. Conclusion The currently available HPV vaccines offer protection only against HPV 16 and 18 and some cross- protection to few associated genotypes. These vaccines are therefore less likely to offer protection against cervical cancer in HIV positive women a high percentage of who were infected with non-16 and non-18 oncogenic HPV genotypes. Additionally, there is a lack of sufficient evidence of immunogenicity in HIV infected individuals. Therefore

  6. In Vitro Partial-Body Dose Assessment Using a Radiation Responsive Protein Biomarker

    Science.gov (United States)

    2005-01-01

    Follow-on epidemiologic analysis of the above objective data will facilitate a health risk assessment. Clinical signs and symptoms are unreliable... Parotid gland Dubray et al., 1992 Cytokines (IL-6, TNF-α) Skin and blood cells Beetz et al., 1997 GADD-45 and proto-oncogenes Blood Papathanasiou...et al., 1991 Substance P Parotid gland Aalto et al., 1995 Figure 2 Proto-oncogene and DNA repair protein expression Figure 2: Time course of

  7. SIRT3: Oncogene and Tumor Suppressor in Cancer

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    Margalida Torrens-Mas

    2017-07-01

    Full Text Available Sirtuin 3 (SIRT3, the major deacetylase in mitochondria, plays a crucial role in modulating oxygen reactive species (ROS and limiting the oxidative damage in cellular components. SIRT3 targets different enzymes which regulate mitochondrial metabolism and participate in ROS detoxification, such as the complexes of the respiratory chain, the isocitrate dehydrogenase, or the manganese superoxide dismutase. Thus, SIRT3 activity is essential in maintaining mitochondria homeostasis and has recently received great attention, as it is considered a fidelity protein for mitochondrial function. In some types of cancer, SIRT3 functions as a tumoral promoter, since it keeps ROS levels under a certain threshold compatible with cell viability and proliferation. On the contrary, other studies describe SIRT3 as a tumoral suppressor, as SIRT3 could trigger cell death under stress conditions. Thus, SIRT3 could have a dual role in cancer. In this regard, modulation of SIRT3 activity could be a new target to develop more personalized therapies against cancer.

  8. Proto-oncogene HER-2 in normal, dysplastic and tumorous feline mammary glands: an immunohistochemical and chromogenic in situ hybridization study

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    Martín de las Mulas Juana

    2007-09-01

    Full Text Available Abstract Background Feline mammary carcinoma has been proposed as a natural model of highly aggressive, hormone-independent human breast cancer. To further explore the utility of the model by adding new similarities between the two diseases, we have analyzed the oncogene HER-2 status at both the protein and the gene levels. Methods Formalin-fixed, paraffin-embedded tissue samples from 30 invasive carcinomas, 7 benign lesions and two normal mammary glands were analyzed. Tumour features with prognostic value were recorded. The expression of protein HER-2 was analyzed by immunohistochemistry and the number of gene copies by means of DNA chromogenic in situ hybridization. Results Immunohistochemical HER-2 protein overexpression was found in 40% of feline mammary carcinomas, a percentage higher to that observed in human breast carcinoma. As in women, feline tumours with HER-2 protein overexpression had pathological features of high malignancy. However, amplification of HER-2 was detected in 16% of carcinomas with protein overexpression, a percentage much lower than that observed in their human counterpart. Conclusion Feline mammary carcinoma would be a suitable natural model of that subset of human breast carcinomas with HER-2 protein overexpression without gene amplification.

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

    Science.gov (United States)

    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

  10. Hypomethylation of a LINE-1 promoter activates an alternate transcript of the MET oncogene in bladders with cancer.

    Science.gov (United States)

    Wolff, Erika M; Byun, Hyang-Min; Han, Han F; Sharma, Shikhar; Nichols, Peter W; Siegmund, Kimberly D; Yang, Allen S; Jones, Peter A; Liang, Gangning

    2010-04-22

    It was recently shown that a large portion of the human transcriptome can originate from within repetitive elements, leading to ectopic expression of protein-coding genes. However the mechanism of transcriptional activation of repetitive elements has not been definitively elucidated. For the first time, we directly demonstrate that hypomethylation of retrotransposons can cause altered gene expression in humans. We also reveal that active LINE-1s switch from a tetranucleosome to dinucleosome structure, acquiring H2A.Z- and nucleosome-free regions upstream of TSSs, previously shown only at active single-copy genes. Hypomethylation of a specific LINE-1 promoter was also found to induce an alternate transcript of the MET oncogene in bladder tumors and across the entire urothelium of tumor-bearing bladders. These data show that, in addition to contributing to chromosomal instability, hypomethylation of LINE-1s can alter the functional transcriptome and plays a role not only in human disease but also in disease predisposition.

  11. The FGFR4 Y367C mutant is a dominant oncogene in MDA-MB453 breast cancer cells.

    Science.gov (United States)

    Roidl, A; Foo, P; Wong, W; Mann, C; Bechtold, S; Berger, H J; Streit, S; Ruhe, J E; Hart, S; Ullrich, A; Ho, H K

    2010-03-11

    Mutational analysis of oncogenes is critical for our understanding of cancer development. Oncogenome screening has identified a fibroblast growth factor receptor 4 (FGFR4) Y367C mutation in the human breast cancer cell line MDA-MB453. Here, we investigate the consequence of this missense mutation in cancer cells. We show that MDA-MB453 cells harbouring the mutation are insensitive to FGFR4-specific ligand stimulation or inhibition with an antagonistic antibody. Furthermore, the FGFR4 mutant elicits constitutive phosphorylation leading to an activation of the mitogen-activated protein kinase cascade as shown by an enhanced Erk1/2 phosphorylation. Cloning and ectopic expression of the FGFR4 Y367C mutant in HEK293 cells revealed high pErk levels and enhanced cell proliferation. Based on these findings, we propose that FGFR4 may be a driver of tumour growth, particularly when highly expressed or stabilized and constitutively activated through genetic alterations. As such, FGFR4 presents an option for further mutational screening in tumours and is an attractive cancer target with the therapeutic potential.

  12. Hypomethylation of a LINE-1 promoter activates an alternate transcript of the MET oncogene in bladders with cancer.

    Directory of Open Access Journals (Sweden)

    Erika M Wolff

    2010-04-01

    Full Text Available It was recently shown that a large portion of the human transcriptome can originate from within repetitive elements, leading to ectopic expression of protein-coding genes. However the mechanism of transcriptional activation of repetitive elements has not been definitively elucidated. For the first time, we directly demonstrate that hypomethylation of retrotransposons can cause altered gene expression in humans. We also reveal that active LINE-1s switch from a tetranucleosome to dinucleosome structure, acquiring H2A.Z- and nucleosome-free regions upstream of TSSs, previously shown only at active single-copy genes. Hypomethylation of a specific LINE-1 promoter was also found to induce an alternate transcript of the MET oncogene in bladder tumors and across the entire urothelium of tumor-bearing bladders. These data show that, in addition to contributing to chromosomal instability, hypomethylation of LINE-1s can alter the functional transcriptome and plays a role not only in human disease but also in disease predisposition.

  13. c-RET molecule in malignant melanoma from oncogenic RET-carrying transgenic mice and human cell lines.

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    Yuichiro Ohshima

    Full Text Available Malignant melanoma is one of the most aggressive cancers and its incidence worldwide has been increasing at a greater rate than that of any other cancer. We previously reported that constitutively activated RFP-RET-carrying transgenic mice (RET-mice spontaneously develop malignant melanoma. In this study, we showed that expression levels of intrinsic c-Ret, glial cell line-derived neurotrophic factor (Gdnf and Gdnf receptor alpha 1 (Gfra1 transcripts in malignant melanomas from RET-transgenic mice were significantly upregulated compared with those in benign melanocytic tumors. These results suggest that not only introduced oncogenic RET but also intrinsic c-Ret/Gdnf are involved in murine melanomagenesis in RET-mice. We then showed that c-RET and GDNF transcript expression levels in human malignant melanoma cell lines (HM3KO and MNT-1 were higher than those in primary cultured normal human epithelial melanocytes (NHEM, while GFRa1 transcript expression levels were comparable among NHEM, HM3KO and MNT-1. We next showed c-RET and GFRa1 protein expression in HM3KO cells and GDNF-mediated increased levels of their phosphorylated c-RET tyrosine kinase and signal transduction molecules (ERK and AKT sited potentially downstream of c-RET. Taken together with the finding of augmented proliferation of HM3KO cells after GDNF stimulation, our results suggest that GDNF-mediated c-RET kinase activation is associated with the pathogenesis of malignant melanoma.

  14. Active macropinocytosis induction by stimulation of epidermal growth factor receptor and oncogenic Ras expression potentiates cellular uptake efficacy of exosomes.

    Science.gov (United States)

    Nakase, Ikuhiko; Kobayashi, Nahoko Bailey; Takatani-Nakase, Tomoka; Yoshida, Tetsuhiko

    2015-06-03

    Exosomes are approximately 100-nm vesicles that consist of a lipid bilayer of cellular membranes secreted in large quantities from various types of normal and disease-related cells. Endocytosis has been reported as a major pathway for the cellular uptake of exosomes; however, the detailed mechanisms of their cellular uptake are still unknown. Here, we demonstrate the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. We also demonstrate that oncogenic K-Ras-expressing MIA PaCa-2 cells exhibit intensive macropinocytosis that actively transports extracellular exosomes into the cells compared with wild-type K-Ras-expressing BxPC-3 cells. Furthermore, encapsulation of the ribosome-inactivating protein saporin with EGF in exosomes using our simple electroporation method produces superior cytotoxicity via the enhanced cellular uptake of exosomes. Our findings contribute to the biological, pharmaceutical, and medical research fields in terms of understanding the macropinocytosis-mediated cellular uptake of exosomes with applications for exosomal delivery systems.

  15. Expression and function of the novel proto-oncogene PBF in thyroid cancer: a new target for augmenting radioiodine uptake.

    Science.gov (United States)

    Smith, Vicki E; Franklyn, Jayne A; McCabe, Christopher J

    2011-08-01

    Pituitary tumor-transforming gene (PTTG)-binding factor (PBF; PTTG1IP) was initially identified through its interaction with the human securin, PTTG. Like PTTG, PBF is upregulated in multiple endocrine tumours including thyroid cancer. PBF is believed to induce the translocation of PTTG into the cell nucleus where it can drive tumourigenesis via a number of different mechanisms. However, an independent transforming ability has been demonstrated both in vitro and in vivo, suggesting that PBF is itself a proto-oncogene. Studied in only a limited number of publications to date, PBF is emerging as a protein with a growing repertoire of roles. Recent data suggest that PBF possesses a complex multifunctionality in an increasing number of tumour settings. For example, PBF is upregulated by oestrogen and mediates oestrogen-stimulated cell invasion in breast cancer cells. In addition to a possible role in the induction of thyroid tumourigenesis, PBF overexpression in thyroid cancers inhibits iodide uptake. PBF has been shown to repress sodium iodide symporter (NIS) activity by transcriptional regulation of NIS expression through the human NIS upstream enhancer and further inhibits iodide uptake via a post-translational mechanism of NIS governing subcellular localisation. This review discusses the current data describing PBF expression and function in thyroid cancer and highlights PBF as a novel target for improving radioiodine uptake and thus prognosis in thyroid cancer.

  16. Non-oncogenic Acute Viral Infections Disrupt Anti-cancer Responses and Lead to Accelerated Cancer-Specific Host Death

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    Frederick J. Kohlhapp

    2016-10-01

    Full Text Available In light of increased cancer prevalence and cancer-specific deaths in patients with infections, we investigated whether infections alter anti-tumor immune responses. We report that acute influenza infection of the lung promotes distal melanoma growth in the dermis and leads to accelerated cancer-specific host death. Furthermore, we show that during influenza infection, anti-melanoma CD8+ T cells are shunted from the tumor to the infection site, where they express high levels of the inhibitory receptor programmed cell death protein 1 (PD-1. Immunotherapy to block PD-1 reverses this loss of anti-tumor CD8+ T cells from the tumor and decreases infection-induced tumor growth. Our findings show that acute non-oncogenic infection can promote cancer growth, raising concerns regarding acute viral illness sequelae. They also suggest an unexpected role for PD-1 blockade in cancer immunotherapy and provide insight into the immune response when faced with concomitant challenges.

  17. The oncogenic epidermal growth factor receptor variant Xiphophorus melanoma receptor kinase induces motility in melanocytes by modulation of focal adhesions.

    Science.gov (United States)

    Meierjohann, Svenja; Wende, Elisabeth; Kraiss, Anita; Wellbrock, Claudia; Schartl, Manfred

    2006-03-15

    One of the most prominent features of malignant melanoma is the fast generation of metastasizing cells, resulting in the poor prognosis of patients with this tumor type. For this process, cells must gain the ability to migrate. The oncogenic receptor Xmrk (Xiphophorus melanoma receptor kinase) from the Xiphophorus melanoma system is a mutationally activated version of the epidermal growth factor receptor that induces the malignant transformation of pigment cells. Here, we show that the activation of Xmrk leads to a clear increase of pigment cell motility in a fyn-dependent manner. Stimulation of Xmrk induces its interaction with the focal adhesion kinase (FAK) and the interaction of active, receptor-bound fyn with FAK. This results in changes in FAK activity and induces the modulation of stress fibers and focal adhesions. Overexpression of dominant-negative FAK shows that the activity of innate FAK and a receptor-induced focal adhesion turnover are a prerequisite for pigment cell migration. Our findings show that in our system, Xmrk is sufficient for the induction of pigment cell motility and underlines a role of the src family protein tyrosine kinase fyn in melanoma development and progression.

  18. Patterns of scAAV vector insertion associated with oncogenic events in a mouse model for genotoxicity.

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    Rosas, Lucia E; Grieves, Jessica L; Zaraspe, Kimberly; La Perle, Krista Md; Fu, Haiyan; McCarty, Douglas M

    2012-11-01

    Recombinant adeno-associated virus (rAAV) vectors have gained an extensive record of safety and efficacy in animal models of human disease. Infrequent reports of genotoxicity have been limited to specific vectors associated with excess hepatocellular carcinomas (HCC) in mice. In order to understand potential mechanisms of genotoxicity, and identify patterns of insertion that could promote tumor formation, we compared a self-complementary AAV (scAAV) vector designed to promote insertional activation (scAAV-CBA-null) to a conventional scAAV-CMV-GFP vector. HCC-prone C3H/HeJ mice and severe combined immunodeficiency (SCID) mice were infected with vector plus secondary treatments including partial hepatectomy (HPX) and camptothecin (CPT) to determine the effects of cell cycling and DNA damage on tumor incidence. Infection with either vector led to a significant increase in HCC incidence in male C3H/HeJ mice. Partial HPX after infection reduced HCC incidence in the cytomegalovirus-green fluorescent protein (CMV-GFP)-infected mice, but not in the cognate chicken β-actin (CBA)-null infected group. Tumors from CBA-null infected, hepatectomized mice were more likely to contain significant levels of vector DNA than tumors from the corresponding CMV-GFP-infected group. Most CBA-null vector insertions recovered from tumors were associated with known proto-oncogenes or tumor suppressors. Specific patterns of insertion suggested read-through transcription, enhancer effects, and disruption of tumor suppressors as likely mechanisms for genotoxicity.

  19. Oncogenic transformation through the cell cycle and the LET dependent inverse dose rate effect

    Science.gov (United States)

    Geard, C. R.; Miller, R. C.; Brenner, D. J.; Hall, E. J.; Wachholz, B. W. (Principal Investigator)

    1994-01-01

    Synchronised populations of mouse C3H/10T-1/2 cells were obtained by a stringent mitotic dislodgment procedure. Mitotic cells rapidly attach and progress sequentially through the cell cycle. Irradiation (3 Gy of X rays) was carried out at intervals from 0 to 18 h after initiating cell cycle progression of the mitotic cells. Oncogenic transformation was enhanced 10-fold over cells irradiated soon after replating (G1 and S phases) for cells in a near 2 h period corresponding to cells in G2 phase but not in mitosis. The cell surviving fraction had a 2-1/2-fold variation with resistant peaks corresponding to the late G1 and late S phases. These findings provide experimental support for the hypothesis initiated by Rossi and Kellerer and developed by Brenner and Hall to explain the LET dependent inverse dose rate effect for oncogenic transformation.

  20. Tumor suppression by miR-26 overrides potential oncogenic activity in intestinal tumorigenesis

    Science.gov (United States)

    Zeitels, Lauren R.; Acharya, Asha; Shi, Guanglu; Chivukula, Divya; Chivukula, Raghu R.; Anandam, Joselin L.; Abdelnaby, Abier A.; Balch, Glen C.; Mansour, John C.; Yopp, Adam C.; Richardson, James A.

    2014-01-01

    Down-regulation of miR-26 family members has been implicated in the pathogenesis of multiple malignancies. In some settings, including glioma, however, miR-26-mediated repression of PTEN promotes tumorigenesis. To investigate the contexts in which the tumor suppressor versus oncogenic activity of miR-26 predominates in vivo, we generated miR-26a transgenic mice. Despite measureable repression of Pten, elevated miR-26a levels were not associated with malignancy in transgenic animals. We documented reduced miR-26 expression in human colorectal cancer and, accordingly, showed that miR-26a expression potently suppressed intestinal adenoma formation in Apcmin/+ mice, a model known to be sensitive to Pten dosage. These studies reveal a tumor suppressor role for miR-26 in intestinal cancer that overrides putative oncogenic activity, highlighting the therapeutic potential of miR-26 delivery to this tumor type. PMID:25395662

  1. Plac8 Links Oncogenic Mutations to Regulation of Autophagy and Is Critical to Pancreatic Cancer Progression

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    Conan Kinsey

    2014-05-01

    Full Text Available Mutations in p53 and RAS potently cooperate in oncogenic transformation, and correspondingly, these genetic alterations frequently coexist in pancreatic ductal adenocarcinoma (PDA and other human cancers. Previously, we identified a set of genes synergistically activated by combined RAS and p53 mutations as frequent downstream mediators of tumorigenesis. Here, we show that the synergistically activated gene Plac8 is critical for pancreatic cancer growth. Silencing of Plac8 in cell lines suppresses tumor formation by blocking autophagy, a process essential for maintaining metabolic homeostasis in PDA, and genetic inactivation in an engineered mouse model inhibits PDA progression. We show that Plac8 is a critical regulator of the autophagic machinery, localizing to the lysosomal compartment and facilitating lysosome-autophagosome fusion. Plac8 thus provides a mechanistic link between primary oncogenic mutations and the induction of autophagy, a central mechanism of metabolic reprogramming, during PDA progression.

  2. Chemically robust fluoroalkyl phthalocyanine-oligonucleotide bioconjugates and their GRP78 oncogene photocleavage activity.

    Science.gov (United States)

    Patel, Pradeepkumar; Patel, Hemantbhai H; Borland, Emily; Gorun, Sergiu M; Sabatino, David

    2014-06-18

    The first representative of functionalized fluoroalkyl phthalocyanines, F48H7(COOH)PcZn, is reported. The complex generates (1)O2 affording long-lasting photooxidation of an external substrate without self-decomposition. The carboxylic group couples with an antisense oligonucleotide targeting GRP78 oncogenes, resulting in the F48H7PcZn-cancer targeting oligonucleotide (CTO). The bioconjugated fluorophthalocyanine effectively hybridizes complementary GRP78 DNA and mRNA sequences. Piperidine cleavage assays reveal desired photochemical oligonucleotide oxidative degradation for both F48H7PcZn-CTO:DNA and F48H7PcZn-CTO:mRNA hybrids. This new materials strategy could be extended to other functional fluorinated phthalocyanines-antisense oligonucleotide combinations for long-lasting oncogene-targeting photodynamic therapy.

  3. Repurposing a Prokaryotic Toxin-Antitoxin System for the Selective Killing of Oncogenically Stressed Human Cells.

    Science.gov (United States)

    Preston, Mark A; Pimentel, Belén; Bermejo-Rodríguez, Camino; Dionne, Isabelle; Turnbull, Alice; de la Cueva-Méndez, Guillermo

    2016-07-15

    Prokaryotes express intracellular toxins that pass unnoticed to carrying cells until coexpressed antitoxin partners are degraded in response to stress. Although not evolved to function in eukaryotes, one of these toxins, Kid, induces apoptosis in mammalian cells, an effect that is neutralized by its cognate antitoxin, Kis. Here we engineered this toxin-antitoxin pair to create a synthetic system that becomes active in human cells suffering a specific oncogenic stress. Inspired by the way Kid becomes active in bacterial cells, we produced a Kis variant that is selectively degraded in human cells expressing oncoprotein E6. The resulting toxin-antitoxin system functions autonomously in human cells, distinguishing those that suffer the oncogenic insult, which are killed by Kid, from those that do not, which remain protected by Kis. Our results provide a framework for developing personalized anticancer strategies avoiding off-target effects, a challenge that has been hardly tractable by other means thus far.

  4. MiR-191 Regulates Primary Human Fibroblast Proliferation and Directly Targets Multiple Oncogenes.

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    Damon Polioudakis

    Full Text Available miRNAs play a central role in numerous pathologies including multiple cancer types. miR-191 has predominantly been studied as an oncogene, but the role of miR-191 in the proliferation of primary cells is not well characterized, and the miR-191 targetome has not been experimentally profiled. Here we utilized RNA induced silencing complex immunoprecipitations as well as gene expression profiling to construct a genome wide miR-191 target profile. We show that miR-191 represses proliferation in primary human fibroblasts, identify multiple proto-oncogenes as novel miR-191 targets, including CDK9, NOTCH2, and RPS6KA3, and present evidence that miR-191 extensively mediates target expression through coding sequence (CDS pairing. Our results provide a comprehensive genome wide miR-191 target profile, and demonstrate miR-191's regulation of primary human fibroblast proliferation.

  5. RNA-DNA differences are rarer in proto-oncogenes than in tumor suppressor genes.

    Science.gov (United States)

    Gao, Feng; Lin, Yan; Zhang, Randy Ren

    2012-01-01

    It has long been assumed that DNA sequences and corresponding RNA transcripts are almost identical; a recent discovery, however, revealed widespread RNA-DNA differences (RDDs), which represent a largely unexplored aspect of human genome variation. It has been speculated that RDDs can affect disease susceptibility and manifestations; however, almost nothing is known about how RDDs are related to disease. Here, we show that RDDs are rarer in proto-oncogenes than in tumor suppressor genes; the number of RDDs in coding exons, but not in 3'UTR and 5'UTR, is significantly lower in the former than the latter, and this trend is especially pronounced in non-synonymous RDDs, i.e., those cause amino acid changes. A potential mechanism is that, unlike proto-oncogenes, the requirement of tumor suppressor genes to have both alleles affected to cause tumor 'buffers' these genes to tolerate more RDDs.

  6. MiR-191 Regulates Primary Human Fibroblast Proliferation and Directly Targets Multiple Oncogenes.

    Science.gov (United States)

    Polioudakis, Damon; Abell, Nathan S; Iyer, Vishwanath R

    2015-01-01

    miRN