WorldWideScience

Sample records for oncogenes

  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. 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.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  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. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Oncogenic extracellular vesicles in brain tumour progression

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

  19. Intracortical osteoblastic osteosarcoma with oncogenic rickets

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. 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.

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. In Silico Analysis of Oncogenes for Renal Cancer

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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...

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

    Science.gov (United States)

    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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Advances on Driver Oncogenes of Squamous Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    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.

  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. 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...

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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.

  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. ERBB oncogene proteins as targets for monoclonal antibodies.

    Science.gov (United States)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  8. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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'.

  11. REST regulates oncogenic properties of glioblastoma stem cells

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  15. 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

  16. 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

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

    Science.gov (United States)

    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.

  18. 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...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. 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.

  13. 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].

  14. Activating mutation in MET oncogene in familial colorectal cancer

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. 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.

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

    Science.gov (United States)

    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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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)

  6. 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 ...

  7. 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.

  8. 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.

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

    Science.gov (United States)

    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

  10. 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.

  11. [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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

  14. 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

  15. 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.

  16. 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.

  17. Spi-1, Fli-1 and Fli-3 (miR-17-92 oncogenes contribute to a single oncogenic network controlling cell proliferation in friend erythroleukemia.

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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.

  20. 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.

  1. 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....

  2. 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

  3. 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...

  4. High frequency of the HRAS oncogene codon 12 mutation in Macedonian patients with urinary bladder cancer

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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 ...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. [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).

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

    Energy Technology Data Exchange (ETDEWEB)

    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. 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....

  1. 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...

  2. 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)

  3. 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

  4. 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...

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  19. 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...

  20. 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

    2014-01-01

    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

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  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. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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...

  12. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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.

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 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.

  2. 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.

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

    Science.gov (United States)

    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.

  4. 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.

  5. 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

  6. Oncogenic HPV among HIV infected female population in West Bengal, India

    Directory of Open Access Journals (Sweden)

    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

  7. 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

  8. 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

  9. 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.

  10. 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

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

    Science.gov (United States)

    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.

  12. Plac8 Links Oncogenic Mutations to Regulation of Autophagy and Is Critical to Pancreatic Cancer Progression

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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.

  15. MiR-191 Regulates Primary Human Fibroblast Proliferation and Directly Targets Multiple Oncogenes.

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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

    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.

  18. DNA Oncogenic Virus-Induced Oxidative Stress, Genomic Damage, and Aberrant Epigenetic Alterations

    Directory of Open Access Journals (Sweden)

    Mankgopo Magdeline Kgatle

    2017-01-01

    Full Text Available Approximately 20% of human cancers is attributable to DNA oncogenic viruses such as human papillomavirus (HPV, hepatitis B virus (HBV, and Epstein-Barr virus (EBV. Unrepaired DNA damage is the most common and overlapping feature of these DNA oncogenic viruses and a source of genomic instability and tumour development. Sustained DNA damage results from unceasing production of reactive oxygen species and activation of inflammasome cascades that trigger genomic changes and increased propensity of epigenetic alterations. Accumulation of epigenetic alterations may interfere with genome-wide cellular signalling machineries and promote malignant transformation leading to cancer development. Untangling and understanding the underlying mechanisms that promote these detrimental effects remain the major objectives for ongoing research and hope for effective virus-induced cancer therapy. Here, we review current literature with an emphasis on how DNA damage influences HPV, HVB, and EBV replication and epigenetic alterations that are associated with carcinogenesis.

  19. Immortalized cells and one oncogene in malignant transformation: old insights on new explanation

    Science.gov (United States)

    2011-01-01

    Background Nearly thirty years ago, it was first shown that malignant transformation with single oncogene necessarily requires the immortal state of the cell. From that time this thesis for the cells of human origin was not disproved. The basic point which we want to focus on by this short communication is the correct interpretation of the results obtained on the widely used human embryonic kidney 293 (HEK293) cells. Results Intensive literature analysis revealed an increasing number of recent studies discovering new oncogenes with non-overlapping functions. Since the 1970s, dozens of oncogenes have been identified in human cancer. Cultured cell lines are often used as model systems in these experiments. In some investigations the results obtained on such cells are interpreted by the authors as a malignant transformation of normal animal or even normal human cells (as for example with HEK293 cells). However, when a cell line gains the ability to undergo continuous cell division, the cells are not normal any more, they are immortalized cells. Nevertheless, the authors consider these cells as normal human ones, what is basically incorrect. Moreover, it was early demonstrated that the widely used human embryonic kidney 293 (HEK293) cells have a relationship to neurons. Conclusions Thus, the experiments with established cell lines reinforce the notion that immortality is an essential requirement for malignant transformation that cooperates with other oncogenic changes to program the neoplastic state and substances under such investigation should be interpreted as factors which do not malignantly transform normal cells alone, but possess the ability to enhance the tumorigenic potential of already immortalized cells. PMID:21605454

  20. Activation of cellular oncogenes by chemical carcinogens in Syrian hamster embryo fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, R.; Reiss, E.; Roellich, G.; Schiffmann, D. (Univ. of Wuerzburg (West Germany)); Barrett, J.C.; Wiseman, R.W. (National Institute of Environmental Health Sciences, Research Triangle Park, NC (USA)); Pechan, R.

    1990-08-01

    Carcinogen-induced point mutations resulting in activation of ras oncogenes have been demonstrated in various experimental systems such as skin carcinogenesis, mammary, and liver carcinogenesis. In many cases, the data support the conclusion that these point mutations are critical changes in the initiation of these tumors. The Syrian hamster embryo (SHE) cell transformation model system has been widely used to study the multistep process of chemically induced neoplastic transformation. Recent data suggest that activation of the Ha-ras gene via point mutation is one of the crucial events in the transformation of these cells. The authors have now cloned the c-Ha-ras proto-oncogene from SHE cDNA-libraries, and we have performed polymerase chain reaction and direct sequencing to analyze tumor cell lines induced by different chemical carcinogens for the presence of point mutations. No changes were detectable at codons 12, 13, 59, 61, and 117 or adjacent regions in tumor cell lines induced by diethylstilbestrol, asbestos, benzo(a)pyrene, trenbolone, or aflatoxin B{sub 1}. Thus, it is not known whether point mutations in the Ha-ras proto-oncogene are essential for the acquisition of the neoplastic phenotype of SHE cells. Activation of other oncogenes or inactivation of tumor suppressor genes may be responsible for the neoplastic progression of these cells. However, in SHE cells neoplastically transformed by diethylstilbestrol or trenbolone, a significant elevation of the c-Ha-ras expression was observed. Enhanced expression of c-myc was detected in SHE cells transformed by benzo(a)pyrene or trenbolone.

  1. Oncogenic LINE-1 Retroelements Sustain Prostate Tumor Cells and Promote Metastatic Progression

    Science.gov (United States)

    2015-10-01

    elements in prostate cancer contribute to its progression by activating oncogenic DNA sequences, or silencing tumor suppressor like sequences. We have...the use of animals and the use of recombinant DNA /lentiviral vectors. All of these approvals have now been obtained. For Task 1, we cloned the LINE...Books or other non-periodical, one-time publications. Report any book, monograph , dissertation, abstract, or the like published as or in a

  2. Cooperativity Between Oncogenic PKC Epsilon and Pten Loss in Prostate Cancer Progression

    Science.gov (United States)

    2015-10-01

    initiated studies to dissect the signaling mechanisms that mediate CXCL13 induction. We took advantage of a cellular model that we generated in our...metastatic loop that is mediated by CXCL13. We also hypothesize that PKCε is a CXCL13:CXCR5 effector that contributes to positively amplify this oncogenic...shown). Therefore, it is possible that an autocrine CXCL13:CXCR5 loop mediates effects driven by PKCε overexpression and Pten loss. * * R el at iv

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

    OpenAIRE

    Liu, X; Yang, N; Figel, SA; Wilson, KE; Morrison, CD; Gelman, IH; Zhang, J

    2012-01-01

    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) thro...

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  6. Oncogenic HPV among HIV infected female population in West Bengal, India

    OpenAIRE

    Sengupta Sharmila; Bhattacharya Subhasish; Saha Bibhuti; Bal Baishali; Pal Reshmi; Sarkar Kamalesh; Mazumdar Partha; Chakraborti Shekhar

    2011-01-01

    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, ...

  7. 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.

  8. Detection of FLT3 Oncogene Mutations in Acute Myeloid Leukemia Using Conformation Sensitive Gel Electrophoresis

    OpenAIRE

    2008-01-01

    FLT3 (fms-related tyrosine kinase 3) is a receptor tyrosine kinase class III that is expressed on by early hematopoietic progenitor cells and plays an important role in hematopoietic stem cell proliferation, differentiation and survival. FLT3 is also expressed on leukemia blasts in most cases of acute myeloid leukemia (AML). In order to determine the frequency of FLT3 oncogene mutations, we analyzed genomic DNA of adult de novo acute myeloid leukemia (AML). Polymerase chain reaction (PCR) and...

  9. Oncogenic KRAS activates an embryonic stem cell-like program in human colon cancer initiation

    OpenAIRE

    Le Rolle, Anne-France; Chiu, Thang K; ZENG, ZHAOSHI; Shia, Jinru; Weiser, Martin R; Paty, Philip B.; Chiu, Vi K

    2016-01-01

    Colorectal cancer is the third most frequently diagnosed cancer worldwide. Prevention of colorectal cancer initiation represents the most effective overall strategy to reduce its associated morbidity and mortality. Activating KRAS mutation (KRASmut ) is the most prevalent oncogenic driver in colorectal cancer development, and KRASmut inhibition represents an unmet clinical need. We apply a systems-level approach to study the impact of KRASmut on stem cell signaling during human colon cancer i...

  10. Oncogenic Alternative Splicing Switches: Role in Cancer Progression and Prospects for Therapy

    OpenAIRE

    Serena Bonomi; Stefania Gallo; Morena Catillo; Daniela Pignataro; Giuseppe Biamonti; Claudia Ghigna

    2013-01-01

    Alterations in the abundance or activities of alternative splicing regulators generate alternatively spliced variants that contribute to multiple aspects of tumor establishment, progression and resistance to therapeutic treatments. Notably, many cancer-associated genes are regulated through alternative splicing suggesting a significant role of this post-transcriptional regulatory mechanism in the production of oncogenes and tumor suppressors. Thus, the study of alternative splicing in cancer ...

  11. Oncogenic action of beta, proton, alpha and electron radiation on the rat skin

    Energy Technology Data Exchange (ETDEWEB)

    Burns, F.J.

    1980-01-01

    Rat skin is being utilized as an empirical model for testing dose and time related aspects of the oncogenic action of ionizing radiation, ultraviolet light, and polycyclic aromatic hydrocarbons. Molecular lesions in the skin DNA, including, strand breaks and thymine dimers, are being measured and compared to tumor induction. The induction and repair kinetics of molcular lesions are being compared to split dose repair. Modifiers and radiosensitizers are being utilized to test specific aspects of a chromosome breakage theory of radiation oncogenesis.

  12. Mutation of RET proto-oncogene in Hirschsprung's disease and intestinal neuronal dysplasia

    Institute of Scientific and Technical Information of China (English)

    Jin-Fa Tou; Min-Ju Li; Tao Guan; Ji-Cheng Li; Xiong-Kai Zhu; Zhi-Gang Feng

    2006-01-01

    AIM: To investigate the genetic relationship between Hirschsprung's disease (HD) and intestinal neuronal dysplasia (IND) in Chinese population.METHODS: Peripheral blood samples were obtained from 30 HD patients, 20 IND patients, 18 HD/IND combined patients and 20 normal individuals as control.Genomic DNA was extracted according to standard procedure. Exons 11,13,15,17 of RET proto-oncogene were amplified by polymerase chain reaction (PCR).The mutations of RET proto-oncogene were analyzed by single strand conformational polymorphism (SSCP)and sequencing of the positive amplified products was performed.RESULTS: Eight germline sequence variants were detected. In HD patients, 2 missense mutations in exon 11at nucleotide 15165 G→A (G667S), 2 frameshift mutations in exon 13 at nucleotide 18974 (18974insG), 1missense mutation in exon 13 at nucleotide 18919 A→G (K756E) and 1silent mutation in exon 15 at nucleotide 20692 G→A(Q916Q) were detected. In HD/IND combined patients, 1 missense mutation in exon 11 at nucleotide 15165 G→A and 1 silent mutation in exon 13at nucleotide 18888 T→G (L745L) were detected. No mutation was found in IND patients and controls.CONCLUSION: Mutation of RET proto-oncogene is involved in the etiopathogenesis of HD. The frequency of RET proto-oncogene mutation is quite different between IND and HD in Chinese population. IND is a distinct clinical entity genetically different from HD.

  13. Exosomes enriched in stemness/metastatic-related mRNAS promote oncogenic potential in breast cancer

    OpenAIRE

    2015-01-01

    Cancer cells efficiently transfer exosome contents (essentially mRNAs and microRNAs) to other cell types, modifying immune responses, cell growth, angiogenesis and metastasis. Here we analyzed the exosomes release by breast tumor cells with different capacities of stemness/metastasis based on CXCR4 expression, and evaluated their capacity to generate oncogenic features in recipient cells. Breast cancer cells overexpressing CXCR4 showed an increase in stemness-related markers, and in prolifera...

  14. Panaxquin quefolium diolsaponins dose-dependently inhibits the proliferation of vascular smooth muscle cells by downregulating proto-oncogene expression

    Directory of Open Access Journals (Sweden)

    Zhihao Wang

    2013-01-01

    Conclusions: Our study demonstrates that PQDS may reduce AngII-stimulated VSMC proliferation by suppressing the expression of proto-oncogenes. These results may provide insights for the development of novel traditional Chinese medicines to prevent atherosclerosis.

  15. A human cellular sequence implicated in trk oncogene activation is DNA damage inducible

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Ishai, R.; Scharf, R.; Sharon, R.; Kapten, I. (Technion-Israel Institute of Technology, Haifa (Israel))

    1990-08-01

    Xeroderma pigmentosum cells, which are deficient in the repair of UV light-induced DNA damage, have been used to clone DNA-damage-inducible transcripts in human cells. The cDNA clone designated pC-5 hybridizes on RNA gel blots to a 1-kilobase transcript, which is moderately abundant in nontreated cells and whose synthesis is enhanced in human cells following UV irradiation or treatment with several other DNA-damaging agents. UV-enhanced transcription of C-5 RNA is transient and occurs at lower fluences and to a greater extent in DNA-repair-deficient than in DNA-repair-proficient cells. Southern blot analysis indicates that the C-5 gene belongs to a multigene family. A cDNA clone containing the complete coding sequence of C-5 was isolated. Sequence analysis revealed that it is homologous to a human cellular sequence encoding the amino-terminal activating sequence of the trk-2h chimeric oncogene. The presence of DNA-damage-responsive sequences at the 5' end of a chimeric oncogene could result in enhanced expression of the oncogene in response to carcinogens.

  16. Features and Usage Areas of MicroRNAs as Oncogenes and Tumor Suppressors

    Directory of Open Access Journals (Sweden)

    G. Seyda Seydel

    2009-02-01

    Full Text Available MicroRNAs (miRNA are small non-coding RNA of 19–24 nucleotides in length that were discovered 12 years ago by Victor Ambros and colleagues. They are important regulatory molecules in animals and plants. MicroRNAs are downregulate gene expression during various crucial cell processes such as apoptosis, differentiation and development. In addition, some miRNAs may function as oncogenes or tumor suppressors. More than 50% of miRNA genes are located in cancer-associated genomic regions or in fragile sites. Overexpressed miRNAs in cancers, such as mir17–92, may function as oncogenes and promote cancer development by negatively regulating tumor suppressor genes and genes that control cell differentiation or apoptosis. Underexpressed miRNAs in cancers, such as let–7, function as tumor suppressor genes and may inhibit cancers by regulating oncogenes and genes that control cell differentiation or apoptosis. miRNA expression profiles may become useful biomarkers for cancer diagnostics. [Archives Medical Review Journal 2009; 18(1.000: 1-12

  17. HER2 missense mutations have distinct effects on oncogenic signaling and migration

    Science.gov (United States)

    Zabransky, Daniel J.; Yankaskas, Christopher L.; Cochran, Rory L.; Wong, Hong Yuen; Croessmann, Sarah; Chu, David; Kavuri, Shyam M.; Red Brewer, Monica; Rosen, D. Marc; Dalton, W. Brian; Cimino-Mathews, Ashley; Cravero, Karen; Button, Berry; Kyker-Snowman, Kelly; Cidado, Justin; Erlanger, Bracha; Parsons, Heather A.; Manto, Kristen M.; Bose, Ron; Lauring, Josh; Arteaga, Carlos L.; Konstantopoulos, Konstantinos; Park, Ben Ho

    2015-01-01

    Recurrent human epidermal growth factor receptor 2 (HER2) missense mutations have been reported in human cancers. These mutations occur primarily in the absence of HER2 gene amplification such that most HER2-mutant tumors are classified as “negative” by FISH or immunohistochemistry assays. It remains unclear whether nonamplified HER2 missense mutations are oncogenic and whether they are targets for HER2-directed therapies that are currently approved for the treatment of HER2 gene-amplified breast cancers. Here we functionally characterize HER2 kinase and extracellular domain mutations through gene editing of the endogenous loci in HER2 nonamplified human breast epithelial cells. In in vitro and in vivo assays, the majority of HER2 missense mutations do not impart detectable oncogenic changes. However, the HER2 V777L mutation increased biochemical pathway activation and, in the context of a PIK3CA mutation, enhanced migratory features in vitro. However, the V777L mutation did not alter in vivo tumorigenicity or sensitivity to HER2-directed therapies in proliferation assays. Our results suggest the oncogenicity and potential targeting of HER2 missense mutations should be considered in the context of cooperating genetic alterations and provide previously unidentified insights into functional analysis of HER2 mutations and strategies to target them. PMID:26508629

  18. 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.

  19.  Oncogenic osteomalacia and its symptoms: hypophosphatemia, bone pain and pathological fractures

    Directory of Open Access Journals (Sweden)

    Sonia Kaniuka-Jakubowska

    2012-08-01

    Full Text Available  Oncogenic osteomalacia (OOM is a rare paraneoplastic syndrome induced by tumor produced phosphaturic factors, i.e. phosphatonins. The disorder is characterized by renal tubular phosphate loss, secondary to this process hypophosphatemia and defective production of active form of vitamin D. The clinical course of oncogenic osteomalacia is characterized by bone pain, pathological fractures, muscle weakness and general fatigue. Osteomalacia-associated tumors are usually located in the upper and lower limbs, with half of the lesions primarily situated in the bones. Most of them are small, slow-growing tumors. Their insignificant size and various location coupled with rare occurrence of the disease and non-specificity of clinical symptoms lead to difficulties in reaching a diagnosis, which is often time-consuming and requires a number of additional tests. The average time between the appearance of the first symptoms and the establishment of an accurate diagnosis and the beginning of treatment is over 2.5 years. The aim of this study is to discuss the pathophysiology of disease symptoms, pathomorphology of tumors, diagnostic methods and treatment of oncogenic osteomalacia.

  20. Notch promotes epithelial-mesenchymal transition during cardiac development and oncogenic transformation

    Science.gov (United States)

    Timmerman, Luika A.; Grego-Bessa, Joaquín; Raya, Angel; Bertrán, Esther; Pérez-Pomares, José María; Díez, Juan; Aranda, Sergi; Palomo, Sergio; McCormick, Frank; Izpisúa-Belmonte, Juan Carlos; de la Pompa, José Luis

    2004-01-01

    Epithelial-to-mesenchymal transition (EMT) is fundamental to both embryogenesis and tumor metastasis. The Notch intercellular signaling pathway regulates cell fate determination throughout metazoan evolution, and overexpression of activating alleles is oncogenic in mammals. Here we demonstrate that Notch activity promotes EMT during both cardiac development and oncogenic transformation via transcriptional induction of the Snail repressor, a potent and evolutionarily conserved mediator of EMT in many tissues and tumor types. In the embryonic heart, Notch functions via lateral induction to promote a selective transforming growth factor-β (TGFβ)-mediated EMT that leads to cellularization of developing cardiac valvular primordia. Embryos that lack Notch signaling elements exhibit severely attenuated cardiac snail expression, abnormal maintenance of intercellular endocardial adhesion complexes, and abortive endocardial EMT in vivo and in vitro. Accordingly, transient ectopic expression of activated Notch1 (N1IC) in zebrafish embryos leads to hypercellular cardiac valves, whereas Notch inhibition prevents valve development. Overexpression of N1IC in immortalized endothelial cells in vitro induces EMT accompanied by oncogenic transformation, with corresponding induction of snail and repression of VE-cadherin expression. Notch is expressed in embryonic regions where EMT occurs, suggesting an intimate and fundamental role for Notch, which may be reactivated during tumor metastasis. PMID:14701881

  1. 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.

  2. Narrowing the focus: a toolkit to systematically connect oncogenic signaling pathways with cancer phenotypes

    Science.gov (United States)

    Singleton, Katherine R.; Wood, Kris C.

    2016-01-01

    Functional genomics approaches such as gain- and loss-of-function screening can efficiently reveal genes that control cancer cell growth, survival, signal transduction, and drug resistance, but distilling the results of large-scale screens into actionable therapeutic strategies is challenging given our incomplete understanding of the functions of many genes. Research over several decades, including the results of large-scale cancer sequencing projects, has made it clear that many oncogenic properties are controlled by a common set of core oncogenic signaling pathways. By directly screening this core set of pathways, rather than much larger numbers of individual genes, it may be possible to more directly and efficiently connect functional genomic screening results with therapeutic targets. Here, we describe the recent development of methods to directly screen oncogenic pathways in high-throughput. We summarize the results of studies that have used pathway-centric screening to map the pathways of resistance to targeted therapies in diverse cancer types, then conclude by expanding on potential future applications of this approach.

  3. 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.

  4. Determination of somatic oncogenic mutations linked to target-based therapies using MassARRAY technology

    Science.gov (United States)

    Llorca-Cardeñosa, Marta J.; Mongort, Cristina; Alonso, Elisa; Navarro, Samuel; Burgues, Octavio; Vivancos, Ana; Cejalvo, Juan Miguel; Perez-Fidalgo, José Alejandro; Roselló, Susana; Ribas, Gloria; Cervantes, Andrés

    2016-01-01

    Somatic mutation analysis represents a useful tool in selecting personalized therapy. The aim of our study was to determine the presence of common genetic events affecting actionable oncogenes using a MassARRAY technology in patients with advanced solid tumors who were potential candidates for target-based therapies. The analysis of 238 mutations across 19 oncogenes was performed in 197 formalin-fixed paraffin-embedded samples of different tumors using the OncoCarta Panel v1.0 (Sequenom Hamburg, Germany). Of the 197 specimens, 97 (49.2%) presented at least one mutation. Forty-nine different oncogenic mutations in 16 genes were detected. Mutations in KRAS and PIK3CA were detected in 40/97 (41.2%) and 30/97 (30.9%) patients respectively. Thirty-one patients (32.0%) had mutations in two genes, 20 of them (64.5%) initially diagnosed with colorectal cancer. The co-occurrence of mutation involved mainly KRAS, PIK3CA, KIT and RET. Mutation profiles were validated using a customized panel and the Junior Next-Generation Sequencing technology (GS-Junior 454, Roche). Twenty-eight patients participated in early clinical trials or received specific treatments according to the molecular characterization (28.0%). MassARRAY technology is a rapid and effective method for identifying key cancer-driving mutations across a large number of samples, which allows for a more appropriate selection for personalized therapies. PMID:26968814

  5. HER2 missense mutations have distinct effects on oncogenic signaling and migration.

    Science.gov (United States)

    Zabransky, Daniel J; Yankaskas, Christopher L; Cochran, Rory L; Wong, Hong Yuen; Croessmann, Sarah; Chu, David; Kavuri, Shyam M; Red Brewer, Monica; Rosen, D Marc; Dalton, W Brian; Cimino-Mathews, Ashley; Cravero, Karen; Button, Berry; Kyker-Snowman, Kelly; Cidado, Justin; Erlanger, Bracha; Parsons, Heather A; Manto, Kristen M; Bose, Ron; Lauring, Josh; Arteaga, Carlos L; Konstantopoulos, Konstantinos; Park, Ben Ho

    2015-11-10

    Recurrent human epidermal growth factor receptor 2 (HER2) missense mutations have been reported in human cancers. These mutations occur primarily in the absence of HER2 gene amplification such that most HER2-mutant tumors are classified as "negative" by FISH or immunohistochemistry assays. It remains unclear whether nonamplified HER2 missense mutations are oncogenic and whether they are targets for HER2-directed therapies that are currently approved for the treatment of HER2 gene-amplified breast cancers. Here we functionally characterize HER2 kinase and extracellular domain mutations through gene editing of the endogenous loci in HER2 nonamplified human breast epithelial cells. In in vitro and in vivo assays, the majority of HER2 missense mutations do not impart detectable oncogenic changes. However, the HER2 V777L mutation increased biochemical pathway activation and, in the context of a PIK3CA mutation, enhanced migratory features in vitro. However, the V777L mutation did not alter in vivo tumorigenicity or sensitivity to HER2-directed therapies in proliferation assays. Our results suggest the oncogenicity and potential targeting of HER2 missense mutations should be considered in the context of cooperating genetic alterations and provide previously unidentified insights into functional analysis of HER2 mutations and strategies to target them.

  6. Depletion of insulin receptor substrate 2 reverses oncogenic transformation induced by v-src

    Institute of Scientific and Technical Information of China (English)

    Hong-zhi SUN; Lin XU; Bo ZHOU; Wei-jin ZANG; Shu-fang WU

    2011-01-01

    Aim: To investigate the role of insulin receptor substrate 2 (IRS-2) in oncogenic transformation induced by v-src. Methods: IRS-2 gene was silenced using small interfering RNAs (siRNAs). Nuclear translocation and interaction of IRS-2 with v-src was determined using subcellular fractionation, confocal microscopy, and immunoprecipitation. The activity of the cyclin D1 promoter and r-DNA promoter was measured with a luciferase assay.Results: Depletion of IRS-2 inhibited R-/v-src cell growth and reverse the oncogenic transformation. IRS-2 bound to src via its two PI3-K binding sites, which are critical for activities involved in the transformation. Nuclear IRS-2 occupied the cyclin D1 and rDNA promoters. The combination of IRS-2 and v-src increased the activity of the two promoters, especially the rDNA promoter.Conclusion: Depletion of insulin receptor substrate 2 could reverse oncogenic transformation induced by v-src.

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

    Science.gov (United States)

    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.

  8. 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.

  9. Proto-oncogenes expression in the process of asthma airway remodeling

    Institute of Scientific and Technical Information of China (English)

    LIU Ying-ge; QI Hao-wen; LI Huan-zhang

    2002-01-01

    Objective: To observe the expression of proto-oncogenes in the process of airway remodeling in asthma. Methods: Guinea pig was used as an asthma model challenged by ovoglobulin. Dot-blot, Northernblot molecular hybridization and immunohistochemistry techniques were used to detect the expression of cfos, c-myc, c-jun and c-sis. Results: Expression of c-fos and c-myc mRNA could not be detected or detected at very low level in the control group. There were greatly increased expression of c-fos and c-nyc mRNA after guinea pigs were challenged by ovoglobulin. Thirty minutes after the challenge, the expression of c-fos and c-myc mRNA reached to the peak and returned to normal level 4 h after the challenge. Immunohistochemistry studies showed that Fos, Myc, Jun and Sis expressed at low level in control group and increased after ovoglobulin stimulation. Immunohistochemically positive cells laid in the plasma of airway epithelium,in cell nucleus of bronchial epithelium and in the inflammatory cells. Pathologic studies showed there were smooth muscle thicken around bronchia and lymphocytes infiltration under mucosa or around bronchia smooth muscle. Conclusion: Proto-oncogenes expressed in airway of asthma in a guinea pig model, proto-oncogenes may have roles in the process of airway remodeling.

  10. Beneficial effects of low dose radiation in response to the oncogenic KRAS induced cellular transformation.

    Science.gov (United States)

    Kim, Rae-Kwon; Kim, Min-Jung; Seong, Ki Moon; Kaushik, Neha; Suh, Yongjoon; Yoo, Ki-Chun; Cui, Yan-Hong; Jin, Young Woo; Nam, Seon Young; Lee, Su-Jae

    2015-10-30

    Recently low dose irradiation has gained attention in the field of radiotherapy. For lack of understanding of the molecular consequences of low dose irradiation, there is much doubt concerning its risks on human beings. In this article, we report that low dose irradiation is capable of blocking the oncogenic KRAS-induced malignant transformation. To address this hypothesis, we showed that low dose irradiation, at doses of 0.1 Gray (Gy); predominantly provide defensive response against oncogenic KRAS -induced malignant transformation in human cells through the induction of antioxidants without causing cell death and acts as a critical regulator for the attenuation of reactive oxygen species (ROS). Importantly, we elucidated that knockdown of antioxidants significantly enhanced ROS generation, invasive and migratory properties and abnormal acini formation in KRAS transformed normal as well as cancer cells. Taken together, this study demonstrates that low dose irradiation reduces the KRAS induced malignant cellular transformation through diminution of ROS. This interesting phenomenon illuminates the beneficial effects of low dose irradiation, suggesting one of contributory mechanisms for reducing the oncogene induced carcinogenesis that intensify the potential use of low dose irradiation as a standard regimen.

  11. Emerging Roles of Agrobacterial Plant-Transforming Oncogenes in Plant Defense Reactions

    Science.gov (United States)

    Bulgakov, Victor P.; Inyushkina, Yuliya V.; Gorpenchenko, Tatiana Y.; Koren, Olga G.; Shkryl, Yuri N.; Zhuravlev, Yuri N.

    2009-01-01

    For recent years, engineering plant metabolic pathways by using rol genes looks promising in several aspects. New directions of rol-gene studies are highlighted in this work underlying the unique regulatory properties of the genes. It is known that following agrobacterial infection, the Agrobacterium rhizogenes rolA, rolB and rolC genes are transferred to plant genome, causing tumor formation and hairy root disease. In this report, we show mat these oncogenes are also involved in regulation of plant defense reactions, including the production of secondary metabolites. Situations occur where the rol genes perform their own critical function to regulate secondary metabolism by bypassing upstream plant control mechanisms and directing defense reactions via a "short cut." The rolC gene expressed in transformed plant cells is efficient in establishing an enhanced resistance of host cells to salt and temperature stresses. The emerging complexity of the rol-gene triggered effects and the involvement of signals generated by these genes in basic processes of cell biology such as calcium and ROS signaling indicate that the plant oncogenes, like some animal protooncogenes, use sophisticated strategies to affect cell growth and differentiation. The data raise the intriguing possibility that some components of plant and animal oncogene signaling pathways share common features.

  12. Gene expression array analyses predict increased proto-oncogene expression in MMTV induced mammary tumors.

    Science.gov (United States)

    Popken-Harris, Pamela; Kirchhof, Nicole; Harrison, Ben; Harris, Lester F

    2006-08-01

    Exogenous infection by milk-borne mouse mammary tumor viruses (MMTV) typically induce mouse mammary tumors in genetically susceptible mice at a rate of 90-95% by 1 year of age. In contrast to other transforming retroviruses, MMTV acts as an insertional mutagen and under the influence of steroid hormones induces oncogenic transformation after insertion into the host genome. As these events correspond with increases in adjacent proto-oncogene transcription, we used expression array profiling to determine which commonly associated MMTV insertion site proto-oncogenes were transcriptionally active in MMTV induced mouse mammary tumors. To verify our gene expression array results we developed real-time quantitative RT-PCR assays for the common MMTV insertion site genes found in RIII/Sa mice (int-1/wnt-1, int-2/fgf-3, int-3/Notch 4, and fgf8/AIGF) as well as two genes that were consistently up regulated (CCND1, and MAT-8) and two genes that were consistently down regulated (FN1 and MAT-8) in the MMTV induced tumors as compared to normal mammary gland. Finally, each tumor was also examined histopathologically. Our expression array findings support a model whereby just one or a few common MMTV insertions into the host genome sets up a dominant cascade of events that leave a characteristic molecular signature.

  13. Modulation of junction tension by tumor suppressors and proto-oncogenes regulates cell-cell contacts.

    Science.gov (United States)

    Bosveld, Floris; Guirao, Boris; Wang, Zhimin; Rivière, Mathieu; Bonnet, Isabelle; Graner, François; Bellaïche, Yohanns

    2016-02-15

    Tumor suppressors and proto-oncogenes play crucial roles in tissue proliferation. Furthermore, de-regulation of their functions is deleterious to tissue architecture and can result in the sorting of somatic rounded clones minimizing their contact with surrounding wild-type (wt) cells. Defects in the shape of somatic clones correlate with defects in proliferation, cell affinity, cell-cell adhesion, oriented cell division and cortical contractility. Combining genetics, live-imaging, laser ablation and computer simulations, we aim to analyze whether distinct or similar mechanisms can account for the common role of tumor suppressors and proto-oncogenes in cell-cell contact regulation. In Drosophila epithelia, the tumor suppressors Fat (Ft) and Dachsous (Ds) regulate cell proliferation, tissue morphogenesis, planar cell polarity and junction tension. By analyzing the evolution over time of ft mutant cells and clones, we show that ft clones reduce their cell-cell contacts with the surrounding wt tissue in the absence of concomitant cell divisions and over-proliferation. This contact reduction depends on opposed changes of junction tensions in the clone bulk and its boundary with neighboring wt tissue. More generally, either clone bulk or boundary junction tension is modulated by the activation of Yorkie, Myc and Ras, yielding similar contact reductions with wt cells. Together, our data highlight mechanical roles for proto-oncogene and tumor suppressor pathways in cell-cell interactions.

  14. Engineering and Functional Characterization of Fusion Genes Identifies Novel Oncogenic Drivers of Cancer. | Office of Cancer Genomics

    Science.gov (United States)

    Oncogenic gene fusions drive many human cancers, but tools to more quickly unravel their functional contributions are needed. Here we describe methodology permitting fusion gene construction for functional evaluation. Using this strategy, we engineered the known fusion oncogenes, BCR-ABL1, EML4-ALK, and ETV6-NTRK3, as well as 20 previously uncharacterized fusion genes identified in TCGA datasets.

  15. Oncogenic EGFR Represses the TET1 DNA Demethylase to Induce Silencing of Tumor Suppressors in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Matteo Forloni

    2016-07-01

    Full Text Available Oncogene-induced DNA methylation-mediated transcriptional silencing of tumor suppressors frequently occurs in cancer, but the mechanism and functional role of this silencing in oncogenesis are not fully understood. Here, we show that oncogenic epidermal growth factor receptor (EGFR induces silencing of multiple unrelated tumor suppressors in lung adenocarcinomas and glioblastomas by inhibiting the DNA demethylase TET oncogene family member 1 (TET1 via the C/EBPα transcription factor. After oncogenic EGFR inhibition, TET1 binds to tumor suppressor promoters and induces their re-expression through active DNA demethylation. Ectopic expression of TET1 potently inhibits lung and glioblastoma tumor growth, and TET1 knockdown confers resistance to EGFR inhibitors in lung cancer cells. Lung cancer samples exhibited reduced TET1 expression or TET1 cytoplasmic localization in the majority of cases. Collectively, these results identify a conserved pathway of oncogenic EGFR-induced DNA methylation-mediated transcriptional silencing of tumor suppressors that may have therapeutic benefits for oncogenic EGFR-mediated lung cancers and glioblastomas.

  16. 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.

  17. The human papillomavirus E6 oncogene dysregulates the cell cycle and contributes to cervical carcinogenesis through two independent activities.

    Science.gov (United States)

    Shai, Anny; Brake, Tiffany; Somoza, Chamorro; Lambert, Paul F

    2007-02-15

    Cervical cancer is a leading cause of death due to cancer among women worldwide. Using transgenic mice to dissect the contributions of the human papillomavirus (HPV) 16 E6 and E7 oncogenes in cervical cancer, E7 was identified previously to be the dominant oncogene. Specifically, when treated with exogenous estrogen for 6 months, E7 transgenic mice developed cancer throughout the reproductive tract, but E6 transgenic mice did not. E6 contributed to carcinogenesis of the reproductive tract, as E6/E7 double transgenic mice treated for 6 months with estrogen developed larger cancers than E7 transgenic mice. In the current study, we investigated whether the E6 oncogene alone could cooperate with estrogen to induce cervical cancer after an extended estrogen treatment period of 9 months. We found that the E6 oncogene synergizes with estrogen to induce cervical cancer after 9 months, indicating that E6 has a weaker but detectable oncogenic potential in the reproductive tract compared with the E7 oncogene. Using transgenic mice that express mutant forms of HPV16 E6, we determined that the interactions of E6 with cellular alpha-helix and PDZ partners correlate with its ability to induce cervical carcinogenesis. In analyzing the tumors arising in E6 transgenic mice, we learned that E6 induces expression of the E2F-responsive genes, Mcm7 and cyclin E, in the absence of the E7 oncogene. E6 also prevented the expression of p16 in tumors of the reproductive tract through a mechanism mediated by the interaction of E6 with alpha-helix partners.

  18. 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.

  19. Myc and Ras oncogenes engage different energy metabolism programs and evoke distinct patterns of oxidative and DNA replication stress.

    Science.gov (United States)

    Maya-Mendoza, Apolinar; Ostrakova, Jitka; Kosar, Martin; Hall, Arnaldur; Duskova, Pavlina; Mistrik, Martin; Merchut-Maya, Joanna Maria; Hodny, Zdenek; Bartkova, Jirina; Christensen, Claus; Bartek, Jiri

    2015-03-01

    Both Myc and Ras oncogenes impact cellular metabolism, deregulate redox homeostasis and trigger DNA replication stress (RS) that compromises genomic integrity. However, how are such oncogene-induced effects evoked and temporally related, to what extent are these kinetic parameters shared by Myc and Ras, and how are these cellular changes linked with oncogene-induced cellular senescence in different cell context(s) remain poorly understood. Here, we addressed the above-mentioned open questions by multifaceted comparative analyses of human cellular models with inducible expression of c-Myc and H-RasV12 (Ras), two commonly deregulated oncoproteins operating in a functionally connected signaling network. Our study of DNA replication parameters using the DNA fiber approach and time-course assessment of perturbations in glycolytic flux, oxygen consumption and production of reactive oxygen species (ROS) revealed the following results. First, overabundance of nuclear Myc triggered RS promptly, already after one day of Myc induction, causing slow replication fork progression and fork asymmetry, even before any metabolic changes occurred. In contrast, Ras overexpression initially induced a burst of cell proliferation and increased the speed of replication fork progression. However, after several days of induction Ras caused bioenergetic metabolic changes that correlated with slower DNA replication fork progression and the ensuing cell cycle arrest, gradually leading to senescence. Second, the observed oncogene-induced RS and metabolic alterations were cell-type/context dependent, as shown by comparative analyses of normal human BJ fibroblasts versus U2-OS sarcoma cells. Third, the energy metabolic reprogramming triggered by Ras was more robust compared to impact of Myc. Fourth, the detected oncogene-induced oxidative stress was due to ROS (superoxide) of non-mitochondrial origin and mitochondrial OXPHOS was reduced (Crabtree effect). Overall, our study provides novel

  20. 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

  1. Combining immunotherapy with oncogene-targeted therapy: a new road for melanoma treatment

    Directory of Open Access Journals (Sweden)

    Mariana eAris

    2015-02-01

    Full Text Available Cutaneous melanoma arises from the malignant transformation of skin melanocytes; its incidence and mortality have been increasing steadily over the last fifty-years, now representing 3% of total tumors. Once melanoma metastasizes, prognosis is somber and therapeutic options are limited. However, the discovery of prevalent BRAF mutations in at least 50% of melanoma tumors led to development of BRAF inhibitors, and other drugs targeting the MAPK pathway including MEK inhibitors, are changing this reality. These recently approved treatments for metastatic melanoma have made a significant impact on patient survival; though the results are shadowed by the appearance of drug-resistance. Combination therapies provide a rational strategy to potentiate efficacy and potentially overcome resistance. Undoubtedly, the last decade has also born an renaissance of immunotherapy, and encouraging advances in metastatic melanoma treatment are illuminating the road. Immune checkpoint blockades, such as CTLA-4 antagonist-antibodies, and multiple cancer vaccines are now invaluable arms of anti-tumor therapy. Recent work has brought to light the delicate relationship between tumor biology and the immune system. Host immunity contributes to the antitumor activity of oncogene-targeted inhibitors within a complex network of cytokines and chemokines. Therefore, combining immunotherapy with oncogene-targeted drugs may be the key to melanoma control. Here we review ongoing clinical studies of combination therapies using both oncogene inhibitors and immunotherapeutic strategies in melanoma patients. We will revisit the preclinical evidence that tested sequential and concurrent schemes in suitable animal models and formed the basis for the current trials. Finally, we will discuss potential future directions of the field.

  2. 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)

  3. The Plasticity of Oncogene Addiction: Implications for Targeted Therapies Directed to Receptor Tyrosine Kinases

    Directory of Open Access Journals (Sweden)

    Vinochani Pillay

    2009-05-01

    Full Text Available A common mutation of the epidermal growth factor receptor (EGFR in glioblastoma multiforme (GBM is an extracellular truncation known as the de2-7 EGFR (or EGFRvIII. Hepatocyte growth factor (HGF is the ligand for the receptor tyrosine kinase (RTK c-Met, and this signaling axis is often active in GBM. The expression of the HGF/c-Met axis or de2-7 EGFR independently enhances GBMgrowth and invasiveness, particularly through the phosphatidylinositol-3 kinase/pAkt pathway. Using RTK arrays, we show that expression of de2-7 EGFR in U87MG GBM cells leads to the coactivation of several RTKs, including platelet-derived growth factor receptor β and c-Met. A neutralizing antibody to HGF (AMG102 did not inhibit de2-7 EGFR-mediated activation of c-Met, demonstrating that it is ligand-independent. Therapy for parental U87MG xenografts with AMG 102 resulted in significant inhibition of tumor growth, whereas U87MG.Δ2-7 xenografts were profoundly resistant. Treatment of U87MG.Δ2-7 xenografts with panitumumab, an anti-EGFR antibody, only partially inhibited tumor growth as xenografts rapidly reverted to the HGF/c-Met signaling pathway. Cotreatment with panitumumab and AMG 102 prevented this escape leading to significant tumor inhibition through an apoptotic mechanism, consistent with the induction of oncogenic shock. This observation provides a rationale for using panitumumab and AMG 102 in combination for the treatment of GBM patients. These results illustrate that GBM cells can rapidly change the RTK driving their oncogene addiction if the alternate RTK signals through the same downstream pathway. Consequently, inhibition of a dominant oncogene by targeted therapy can alter the hierarchy of RTKs resulting in rapid therapeutic resistance.

  4. Microarray-based oncogenic pathway profiling in advanced serous papillary ovarian carcinoma.

    Directory of Open Access Journals (Sweden)

    Xuan Bich Trinh

    Full Text Available INTRODUCTION: 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 expression datasets was done for oncogenic pathway activation scores: AKT, β-Catenin, BRCA, E2F1, EGFR, ER, HER2, INFα, INFγ, MYC, p53, p63, PI3K, PR, RAS, SRC, STAT3, TNFα, and TGFβ and VEGF-A. Advanced serous papillary tumours from uniformly treated patients were selected (N = 464 to find differences independent from stage-, histology- and treatment biases. Survival and correlations with documented prognostic signatures (wound healing response signature WHR/genomic grade index GGI/invasiveness gene signature IGS were analysed. RESULTS: The GGI, WHR, IGS score were unexpectedly increased in chemosensitive versus chemoresistant patients. PR and RAS activation score were associated with survival outcome (p = 0.002;p = 0.004. Increased activations of β-Catenin (p = 0.0009, E2F1 (p = 0.005, PI3K (p = 0.003 and p63 (p = 0.05 were associated with more favourable clinical outcome and were consistently correlated with three prognostic gene signatures. CONCLUSIONS: Oncogenic pathway profiling of advanced serous ovarian tumours revealed that increased β-Catenin, E2F1, p63, PI3K, PR and RAS-pathway activation scores were significantly associated with favourable clinical outcome. WHR, GGI and IGS scores were unexpectedly increased in chemosensitive tumours. Earlier studies have shown that WHR, GGI and IGS are strongly associated with proliferation and that high-proliferative ovarian tumours are more chemosensitive. These findings may indicate opposite confounding of prognostic versus predictive factors when studying biomarkers in epithelial ovarian cancer.

  5. 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.

  6. G-rich proto-oncogenes are targeted for genomic instability in B-cell lymphomas.

    Science.gov (United States)

    Duquette, Michelle L; Huber, Michael D; Maizels, Nancy

    2007-03-15

    Diffuse large B-cell lymphoma is the most common lymphoid malignancy in adults. It is a heterogeneous disease with variability in outcome. Genomic instability of a subset of proto-oncogenes, including c-MYC, BCL6, RhoH, PIM1, and PAX5, can contribute to initial tumor development and has been correlated with poor prognosis and aggressive tumor growth. Lymphomas in which these proto-oncogenes are unstable derive from germinal center B cells that express activation-induced deaminase (AID), the B-cell-specific factor that deaminates DNA to initiate immunoglobulin gene diversification. Proto-oncogene instability is evident as both aberrant hypermutation and translocation, paralleling programmed instability which diversifies the immunoglobulin loci. We have asked if genomic sequence correlates with instability in AID-positive B-cell lymphomas. We show that instability does not correlate with enrichment of the WRC sequence motif that is the consensus for deamination by AID. Instability does correlate with G-richness, evident as multiple runs of the base guanine on the nontemplate DNA strand. Extending previous analysis of c-MYC, we show experimentally that transcription of BCL6 and RhoH induces formation of structures, G-loops, which contain single-stranded regions targeted by AID. We further show that G-richness does not characterize translocation breakpoints in AID-negative B- and T-cell malignancies. These results identify G-richness as one feature of genomic structure that can contribute to genomic instability in AID-positive B-cell malignancies.

  7. Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer

    Science.gov (United States)

    2015-10-01

    Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer 3 Annual Progress Report W81XWH-13-1-0162 Using a Novel...Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and Chemoresistance of Prostate Cancer Feng Yang, Ph.D. Department of...AWARD NUMBER: W81XWH-13-1-0162 TITLE: Using a Novel Transgenic Mouse Model to Study c-Myc Oncogenic Pathway in Castration Resistance and

  8. Kaposi Sarcoma of Childhood: Inborn or Acquired Immunodeficiency to Oncogenic HHV-8.

    Science.gov (United States)

    Jackson, Carolyn C; Dickson, Mark A; Sadjadi, Mahan; Gessain, Antoine; Abel, Laurent; Jouanguy, Emmanuelle; Casanova, Jean-Laurent

    2016-03-01

    Kaposi sarcoma (KS) is an endothelial malignancy caused by human herpes virus-8 (HHV-8) infection. The epidemic and iatrogenic forms of childhood KS result from a profound and acquired T cell deficiency. Recent studies have shown that classic KS of childhood can result from rare single-gene inborn errors of immunity, with mutations in WAS, IFNGR1, STIM1, and TNFRSF4. The pathogenesis of the endemic form of childhood KS has remained elusive. We review childhood KS pathogenesis and its relationship to inherited and acquired immunodeficiency to oncogenic HHV-8.

  9. 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.

  10. 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.

  11. The role of hypoxia inducible factor-1 alpha in bypassing oncogene-induced senescence.

    Directory of Open Access Journals (Sweden)

    Mehtap Kilic Eren

    Full Text Available Oncogene induced senescence (OIS is a sustained anti-proliferative response acutely induced in primary cells via activation of mitogenic oncogenes such as Ras/BRAF. This mechanism acts as an initial barrier preventing normal cells transformation into malignant cell. Besides oncogenic activation and DNA damage response (DDR, senescence is modulated by a plethora of other factors, and one of the most important one is oxygen tension of the tissue. The aim of this study was to determine the impact of hypoxia on RasV12-induced senescence in human diploid fibroblasts (HDFs. We showed here that hypoxia prevents execution of oncogene induced senescence (OIS, through a strong down-regulation of senescence hallmarks, such as SA- β-galactosidase, H3K9me3, HP1γ, p53, p21CIP1 and p16INK4a in association with induction of hypoxia inducible factor-1α (HIF-1α. In addition, hypoxia also decreased marks of H-RasV12-induced DDR in both cell lines through down-regulation of ATM/ATR, Chk1 and Chk2 phosphorylation as well as decreased γ-H2AX positivity. Utilizing shRNA system targeting HIF-1α we show that HIF-1α is directly involved in down regulation of p53 and its target p21CIP1 but not p16INK4a. In line with this finding we found that knock down of HIF-1α leads to a strong induction of apoptotic response, but not restoration of senescence in Ras expressing HDFs in hypoxia. This indicates that HIF-1α is an important player in early steps of tumorigenesis, leading to suppression of senescence through its negative regulation of p53 and p21CIP1. In our work we describe a mechanism through which hypoxia and specifically HIF-1α preclude cells from maintaining senescence-driven anti proliferative response. These findings indicate the possible mechanism through which hypoxic environment helps premalignant cells to evade impingement of cellular failsafe pathways.

  12. Oncogenic mutation profiling in new lung cancer and mesothelioma cell lines

    Directory of Open Access Journals (Sweden)

    Lam DC

    2015-01-01

    Full Text Available David CL Lam,1 Susan Y Luo,1 Wen Deng,2 Johnny SH Kwan,3 Jaime Rodriguez-Canales,4 Annie LM Cheung,5 Grace HW Cheng,6 Chi-Ho Lin,6 Ignacio I Wistuba,4 Pak C Sham,6 Thomas SK Wan,7 Sai-Wah Tsao5 1Department of Medicine, 2School of Nursing, 3Department of Psychiatry, University of Hong Kong, Hong Kong SAR, People’s Republic of China; 4Department of Translational Molecular Pathology, MD Anderson Cancer Center, University of Texas at Houston, Houston, TX, USA; 5Department of Anatomy, 6Center for Genome Sciences, 7Department of Pathology, University of Hong Kong, Hong Kong SAR, People’s Republic of China Background: Thoracic tumor, especially lung cancer, ranks as the top cancer mortality in most parts of the world. Lung adenocarcinoma is the predominant subtype and there is increasing knowledge on therapeutic molecular targets, namely EGFR, ALK, KRAS, and ROS1, among lung cancers. Lung cancer cell lines established with known clinical characteristics and molecular profiling of oncogenic targets like ALK or KRAS could be useful tools for understanding the biology of known molecular targets as well as for drug testing and screening. Materials and methods: Five new cancer cell lines were established from pleural fluid or biopsy tissues obtained from Chinese patients with primary lung adenocarcinomas or malignant pleural mesothelioma. They were characterized by immunohistochemistry, growth kinetics, tests for tumorigenicity, EGFR and KRAS gene mutations, ALK gene rearrangement and OncoSeq mutation profiling. Results: These newly established lung adenocarcinoma and mesothelioma cell lines were maintained for over 100 passages and demonstrated morphological and immunohistochemical features as well as growth kinetics of tumor cell lines. One of these new cell lines bears EML4-ALK rearrangement variant 2, two lung cancer cell lines bear different KRAS mutations at codon 12, and known single nucleotide polymorphism variants were identified in these cell

  13. Normal Expression of a Rearranged and Mutated c-myc Oncogene after Transfection into Fibroblasts

    Science.gov (United States)

    Richman, Adam; Hayday, Adrian

    1989-10-01

    Expression of the c-myc oncogene is deregulated in a variety of malignancies. Rearrangement and mutation of the c-myc locus is a characteristic feature of human Burkitt's lymphoma. Whether deregulation is solely a result of mutation of c-myc or whether it is influenced by the transformed B cell context has not been determined. A translocated and mutated allele of c-myc was stably transfected into fibroblasts. The rearranged allele was expressed indistinguishably from a normal c-myc gene: it had serum-regulated expression, was transcribed with normal promoter preference, and was strongly attenuated. Thus mutations by themselves are insufficient to deregulate c-myc transcription.

  14. 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

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

    Directory of Open Access Journals (Sweden)

    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

  16. 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.

  17. 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.

  18. Attempts on producing lymphoid cell line from Penaeus monodon by induction with SV40-T and 12S EIA oncogenes.

    Science.gov (United States)

    Puthumana, Jayesh; Prabhakaran, Priyaja; Philip, Rosamma; Singh, I S Bright

    2015-12-01

    In an attempt of in vitro transformation, transfection mediated expression of Simian virus-40 (T) antigen (SV40-T) and transduction mediated expression of Adenovirus type 12 early region 1A (12S E1A) oncogene were performed in Penaeus monodon lymphoid cells. pSV3-neo vector encoding SV40-T oncogene and a recombinant baculovirus BacP2-12S E1A-GFP encoding 12S E1A oncogene under the control of hybrid promoters were used. Electroporation and lipofection mediated transformation of SV40-T in lymphoid cells confirmed the transgene expression by phenotypic variation and the expression of GFP in co-transfection experiment. The cells transfected by lipofection (≥ 5%) survived for 14 days with lower toxicity (30%), whilst on electroporation, most of the cells succumbed to death (60%) and survived cells lived up to 7 days. Transduction efficiency in primary lymphoid cells was more than 80% within 14 days of post-transduction, however, an incubation period of 7 days post-transduction was observed without detectable expression of 12S E1A. High level of oncogenic 12S E1A expression were observed after 14 day post-transduction and the proliferating cells survived for more than 90 days with GFP expression, however, without in vitro transformation and immortalization. The study put forth the requirement of transduction mediated 'specific' oncogene expression along with telomerase activation and epigenetic induction for the immortalization and establishment of shrimp cell line.

  19. Effect of track structure and radioprotectors on the induction of oncogenic transformation in murine fibroblasts by heavy ions

    Science.gov (United States)

    Miller, R. C.; Martin, S. G.; Hanson, W. R.; Marino, S. A.; Hall, E. J.

    1998-11-01

    The oncogenic potential of high-energy 56Fe particles (1 GeV/nucleon) accelerated with the Alternating Gradient Synchrotron at the Brookhaven National Laboratory was examined utilizing the mouse C3H 10T12 cell model. The dose-averaged LET for high-energy 56Fe is estimated to be 143 keV/μm with the exposure conditions used in this study. For 56Fe ions, the maximum relative biological effectiveness (RBEmax) values for cell survival and oncogenic transformation were 7.71 and 16.5 respectively. Compared to 150 keV/μm 4He nuclei, high-energy 56Fe nuclei were significantly less effective in cell killing and oncogenic induction. The prostaglandin E1 analog misoprostol, an effective oncoprotector of C3H 10T12 cells exposed to X rays, was evaluated for its potential as a radioprotector of oncogenic transformation with high-energy 56Fe. Exposure of cells to misoprostol did not alter 56Fe cytotoxicity or the rate of 56Fe-induced oncogenic transformation.

  20. 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.

  1. Inhibition of the Pim1 oncogene results in diminished visual function.

    Directory of Open Access Journals (Sweden)

    Jun Yin

    Full Text Available Our objective was to profile genetic pathways whose differential expression correlates with maturation of visual function in zebrafish. Bioinformatic analysis of transcriptomic data revealed Jak-Stat signalling as the pathway most enriched in the eye, as visual function develops. Real-time PCR, western blotting, immunohistochemistry and in situ hybridization data confirm that multiple Jak-Stat pathway genes are up-regulated in the zebrafish eye between 3-5 days post-fertilisation, times associated with significant maturation of vision. One of the most up-regulated Jak-Stat genes is the proto-oncogene Pim1 kinase, previously associated with haematological malignancies and cancer. Loss of function experiments using Pim1 morpholinos or Pim1 inhibitors result in significant diminishment of visual behaviour and function. In summary, we have identified that enhanced expression of Jak-Stat pathway genes correlates with maturation of visual function and that the Pim1 oncogene is required for normal visual function.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Prostate-derived Ets factor, an oncogenic driver in breast cancer.

    Science.gov (United States)

    Sood, Ashwani K; Geradts, Joseph; Young, Jessica

    2017-05-01

    Prostate-derived Ets factor (PDEF), a member of the Ets family of transcription factors, differs from other family members in its restricted expression in normal tissues and its unique DNA-binding motif. These interesting attributes coupled with its aberrant expression in cancer have rendered PDEF a focus of increasing interest by tumor biologists. This review provides a current understanding of the characteristics of PDEF expression and its role in breast cancer. The bulk of the evidence is consistent with PDEF overexpression in most breast tumors and an oncogenic role for this transcription factor in breast cancer. In addition, high PDEF expression in estrogen receptor-positive breast tumors showed significant correlation with poor overall survival in several independent cohorts of breast cancer patients. Together, these findings demonstrate PDEF to be an oncogenic driver of breast cancer and a biomarker of poor prognosis in this cancer. Based on this understanding and the limited expression of PDEF in normal human tissues, the development of PDEF-based therapeutics for prevention and treatment of breast cancer is also discussed.

  5. Targeted tumor-penetrating siRNA nanocomplexes for credentialing the ovarian cancer oncogene ID4.

    Science.gov (United States)

    Ren, Yin; Cheung, Hiu Wing; von Maltzhan, Geoffrey; Agrawal, Amit; Cowley, Glenn S; Weir, Barbara A; Boehm, Jesse S; Tamayo, Pablo; Karst, Alison M; Liu, Joyce F; Hirsch, Michelle S; Mesirov, Jill P; Drapkin, Ronny; Root, David E; Lo, Justin; Fogal, Valentina; Ruoslahti, Erkki; Hahn, William C; Bhatia, Sangeeta N

    2012-08-15

    The comprehensive characterization of a large number of cancer genomes will eventually lead to a compendium of genetic alterations in specific cancers. Unfortunately, the number and complexity of identified alterations complicate endeavors to identify biologically relevant mutations critical for tumor maintenance because many of these targets are not amenable to manipulation by small molecules or antibodies. RNA interference provides a direct way to study putative cancer targets; however, specific delivery of therapeutics to the tumor parenchyma remains an intractable problem. We describe a platform for the discovery and initial validation of cancer targets, composed of a systematic effort to identify amplified and essential genes in human cancer cell lines and tumors partnered with a novel modular delivery technology. We developed a tumor-penetrating nanocomplex (TPN) that comprised small interfering RNA (siRNA) complexed with a tandem tumor-penetrating and membrane-translocating peptide, which enabled the specific delivery of siRNA deep into the tumor parenchyma. We used TPN in vivo to evaluate inhibitor of DNA binding 4 (ID4) as a novel oncogene. Treatment of ovarian tumor-bearing mice with ID4-specific TPN suppressed growth of established tumors and significantly improved survival. These observations not only credential ID4 as an oncogene in 32% of high-grade ovarian cancers but also provide a framework for the identification, validation, and understanding of potential therapeutic cancer targets.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. MicroRNA29a regulates the expression of the nuclear oncogene Ski.

    Science.gov (United States)

    Teichler, Sabine; Illmer, Thomas; Roemhild, Josephine; Ovcharenko, Dmitriy; Stiewe, Thorsten; Neubauer, Andreas

    2011-08-18

    MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate growth and differentiation. miRNAs are frequently located at cancer-specific fragile sites in the human genome, such as chromosome 7q. The nuclear oncogene SKI is up-regulated in acute myeloid leukemia (AML) with -7/del7q. Here we asked whether loss of miRNAs on chromosome 7q may explain this up-regulation. miR-29a expression was found to be down-regulated in AML with -7/del7q. Forced expression of miR-29a down-regulated Ski and its target gene, Nr-CAM, whereas miR-29a inhibition induced Ski expression. Luciferase assays validated a functional binding site for miR-29a in the 3' untranslated region of SKI. Finally, in samples of AML patients, we observed an inverse correlation of Ski and miR-29a expression, respectively. In conclusion, up-regulation of Ski in AML with -7/del7q is caused by loss of miR-29a. miR-29a may therefore function as an important tumor suppressor in AML by restraining expression of the SKI oncogene.

  8. 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.

  9. 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.

  10. Transforming genes among three different oncogenic subgroups of human adenoviruses have similar replicative functions.

    Science.gov (United States)

    Brusca, J S; Chinnadurai, G

    1981-01-01

    We have examined the functional similarity of the transforming genes for replicative functions among three different subgroups of human adenoviruses (A, B, and C), using mutant complementation as an assay. A host range deletion mutant (dl201.2) of Ad2 (nononcogenic subgroup C) lacking about 5% of the viral DNA covering two early gene blocks (E1a and E1b) involved in cellular transformation was isolated and tested for its ability to replicate in nonpermissive KB cells in the presence of Ad7 (weakly oncogenic group B) or ad12 (highly oncogenic group A). The complementation of the mutant defect was demonstrated by cleaving the viral DNA extracted from mixed infected cells or the DNA extracted from purified virions from mixed infected cells with restriction endonuclease BamHI, which produces a different cleavage pattern with the DNA of each serotype. It was found that the defects in E1a plus E1b of dl201.2 could be complemented by Ad7 and Ad12, indicating that these genes in Ad2, Ad7, and Ad12 have similar functions during productive infection. Images PMID:7277578

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Oncogene Mutations in Colorectal Polyps Identified in the Norwegian Colorectal Cancer Prevention (NORCCAP) Screening Study

    Science.gov (United States)

    Lorentzen, Jon A.; Grzyb, Krzysztof; De Angelis, Paula M.; Hoff, Geir; Eide, Tor J.; Andresen, Per Arne

    2016-01-01

    Data are limited on oncogene mutation frequencies in polyps from principally asymptomatic participants of population-based colorectal cancer screening studies. In this study, DNA from 204 polyps, 5 mm or larger, were collected from 176 participants of the NORCCAP screening study and analyzed for mutations in KRAS, BRAF, and PIK3CA including the rarely studied KRAS exons 3 and 4 mutations. KRAS mutations were identified in 23.0% of the lesions and were significantly associated with tubulovillous adenomas and large size. A significantly higher frequency of KRAS mutations in females was associated with mutations in codon 12. The KRAS exon 3 and 4 mutations constituted 23.4% of the KRAS positive lesions, which is a larger proportion compared to previous observations in colorectal cancer. BRAF mutations were identified in 11.3% and were associated with serrated polyps. None of the individuals were diagnosed with de novo or recurrent colorectal cancer during the follow-up time (median 11.2 years). Revealing differences in mutation-spectra according to gender and stages in tumorigenesis might be important for optimal use of oncogenes as therapeutic targets and biomarkers. PMID:27656095

  15. Detection of E6/E7 HPV oncogene transcripts as biomarker of cervical intaepithelial displasia

    Directory of Open Access Journals (Sweden)

    Mauro Carcheri

    2009-09-01

    Full Text Available It is widely accepted that only persistent infection with high risk types of Human Papillomavirus (HPV HR is a significant risk factor for the development of an invasive squamous cervical cancer. The overexpression of viral oncogenes E6/E7 of HPV is considered a necessary process for incurring in a malignant phenotype.A HPV infection can be identified by detection of HPV DNA in biological samples, but the DNAbased tests cannot delineate between transient or persistent and potentially transforming infection. Instead there is many evidence to suggest that detection of HPV gene expression may constitute a more specific approach to highlight a clinically significant infection. Especially seems that the detection of E6/E7 transcripts can be usefully used for identify the women with a persistent HPV infection that will can induce a future cervical cancer. The aim of our study is to investigate if the detection of oncogenic viral gene activity by detecting transcripts of the E6 and E7 genes can be most usefull of HPV-DNA test in the triage of ASCUS or low grade cervical lesions. Our results confirm that HPV E6/E7 mRNA test can be considered a promising method to stratify HPV positive women for risk of future high-grade cervical lesions or cervical intaepithelial neoplasia.

  16. 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.

  17. RUNX3 has an oncogenic role in head and neck cancer.

    Directory of Open Access Journals (Sweden)

    Takaaki Tsunematsu

    Full Text Available BACKGROUND: Runt-related transcription factor 3 (RUNX3 is a tumor suppressor of cancer and appears to be an important component of the transforming growth factor-beta (TGF-ss-induced tumor suppression pathway. Surprisingly, we found that RUNX3 expression level in head and neck squamous cell carcinoma (HNSCC tissues, which is one of the most common types of human cancer, was higher than that in normal tissues by a previously published microarray dataset in our preliminary study. Therefore, here we examined the oncogenic role of RUNX3 in HNSCC. PRINCIPAL FINDINGS: Frequent RUNX3 expression and its correlation with malignant behavior were observed in HNSCC. Ectopic RUNX3 overexpression promoted cell growth and inhibited serum starvation-induced apoptosis and chemotherapeutic drug induced apoptosis in HNSCC cells. These findings were confirmed by RUNX3 knockdown. Moreover, RUNX3 overexpression enhanced tumorsphere formation. RUNX3 expression level was well correlated with the methylation status in HNSCC cells. Moreover, RUNX3 expression was low due to the methylation of its promoter in normal oral epithelial cells. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that i RUNX3 has an oncogenic role in HNSCC, ii RUNX3 expression observed in HNSCC may be caused in part by demethylation during cancer development, and iii RUNX3 expression can be a useful marker for predicting malignant behavior and the effect of chemotherapeutic drugs in HNSCC.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. The oncogenic roles of Notch1 in astrocytic gliomas in vitro and in vivo.

    Science.gov (United States)

    Xu, Peng; Qiu, Mingzhe; Zhang, Zhiyong; Kang, Chunsheng; Jiang, Rongcai; Jia, Zhifan; Wang, Guangxiu; Jiang, Hao; Pu, Peiyu

    2010-03-01

    Notch receptors play an essential role in cellular processes during embryonic and postnatal development, including maintenance of stem cell self-renewal, proliferation, and determination of cell fate and apoptosis. Deregulation of Notch signaling has been implicated in some genetic diseases and tumorigenesis. The function of Notch signaling in a variety of tumors can be either oncogenic or tumor-suppressive, depending on the cellular context. In this study, Notch1 overexpression was observed in the majority of 45 astrocytic gliomas with different grades and in U251MG glioma cells. Transfection of siRNA targeting Notch1 into U251 cells in vitro downregulated Notch1 expression, associated with inhibition of cell growth, arrest of cell cycle, reduction of cell invasiveness, and induction of cell apoptosis. Meanwhile, tumor growth was delayed in established subcutaneous gliomas in nude mice treated with Notch1 siRNA in vivo. These results suggest that Notch1 plays an important oncogenic role in the development and progression of astrocytic gliomas. Furthermore, knockdown of Notch1 expression by siRNA simultaneously downregulated the expression of EGFR and the important components of its downstream pathways, including PI3K, p-AKT, K-Ras, cyclin D1 and MMP9, indicating the crosstalk and interaction of Notch and EGFR signaling pathways.

  1. Hepatocellular alterations and dysregulation of oncogenic pathways in the liver of transgenic mice overexpressing growth hormone.

    Science.gov (United States)

    Miquet, Johanna G; Freund, Thomas; Martinez, Carolina S; González, Lorena; Díaz, María E; Micucci, Giannina P; Zotta, Elsa; Boparai, Ravneet K; Bartke, Andrzej; Turyn, Daniel; Sotelo, Ana I

    2013-04-01

    Growth hormone (GH) overexpression throughout life in transgenic mice is associated with the development of liver tumors at old ages. The preneoplastic pathology observed in the liver of young adult GH-overexpressing mice is similar to that present in humans at high risk of hepatic cancer. To elucidate the molecular pathogenesis underlying the pro-oncogenic liver pathology induced by prolonged exposure to elevated GH levels, the activation and expression of several components of signal transduction pathways that have been implicated in hepatocellular carcinogenesis were evaluated in the liver of young adult GH-transgenic mice. In addition, males and females were analyzed in parallel in order to evaluate sexual dimorphism. Transgenic mice from both sexes exhibited hepatocyte hypertrophy with enlarged nuclear size and exacerbated hepatocellular proliferation, which were higher in males. Dysregulation of several oncogenic pathways was observed in the liver of GH-overexpressing transgenic mice. Many signaling mediators and effectors were upregulated in transgenic mice compared with normal controls, including Akt2, NFκB, GSK3β, β-catenin, cyclin D1, cyclin E, c-myc, c-jun and c-fos. The molecular alterations described did not exhibit sexual dimorphism in transgenic mice except for higher gene expression and nuclear localization of cyclin D1 in males. We conclude that prolonged exposure to GH induces in the liver alterations in signaling pathways involved in cell growth, proliferation and survival that resemble those found in many human tumors.

  2. mTORC1 is a critical mediator of oncogenic Semaphorin3A signaling

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Daisuke; Kawahara, Kohichi; Maeda, Takehiko, E-mail: maeda@nupals.ac.jp

    2016-08-05

    Aberration of signaling pathways by genetic mutations or alterations in the surrounding tissue environments can result in tumor development or metastasis. However, signaling molecules responsible for these processes have not been completely elucidated. Here, we used mouse Lewis lung carcinoma cells (LLC) to explore the mechanism by which the oncogenic activity of Semaphorin3A (Sema3A) signaling is regulated. Sema3A knockdown by shRNA did not affect apoptosis, but decreased cell proliferation in LLCs; both the mammalian target of rapamycin complex 1 (mTORC1) level and glycolytic activity were also decreased. In addition, Sema3A knockdown sensitized cells to inhibition of oxidative phosphorylation by oligomycin, but conferred resistance to decreased cell viability induced by glucose starvation. Furthermore, recombinant SEMA3A rescued the attenuation of cell proliferation and glycolytic activity in LLCs after Sema3A knockdown, whereas mTORC1 inhibition by rapamycin completely counteracted this effect. These results demonstrate that Sema3A signaling exerts its oncogenic effect by promoting an mTORC1-mediated metabolic shift from oxidative phosphorylation to aerobic glycolysis. -- Highlights: •Sema3A knockdown decreased proliferation of Lewis lung carcinoma cells (LLCs). •Sema3A knockdown decreased mTORC1 levels and glycolytic activity in LLCs. •Sema3A knockdown sensitized cells to inhibition of oxidative phosphorylation. •Sema3A promotes shift from oxidative phosphorylation to aerobic glycolysis via mTORC1.

  3. RUNX3 is a novel negative regulator of oncogenic TEAD-YAP complex in gastric cancer.

    Science.gov (United States)

    Qiao, Y; Lin, S J; Chen, Y; Voon, D C-C; Zhu, F; Chuang, L S H; Wang, T; Tan, P; Lee, S C; Yeoh, K G; Sudol, M; Ito, Y

    2016-05-19

    Runt-related transcription factor 3 (RUNX3) is a well-documented tumour suppressor that is frequently inactivated in gastric cancer. Here, we define a novel mechanism by which RUNX3 exerts its tumour suppressor activity involving the TEAD-YAP complex, a potent positive regulator of proliferative genes. We report that the TEAD-YAP complex is not only frequently hyperactivated in liver and breast cancer, but also confers a strong oncogenic activity in gastric epithelial cells. The increased expression of TEAD-YAP in tumour tissues significantly correlates with poorer overall survival of gastric cancer patients. Strikingly, RUNX3 physically interacts with the N-terminal region of TEAD through its Runt domain. This interaction markedly reduces the DNA-binding ability of TEAD that attenuates the downstream signalling of TEAD-YAP complex. Mutation of RUNX3 at Arginine 122 to Cysteine, which was previously identified in gastric cancer, impairs the interaction between RUNX3 and TEAD. Our data reveal that RUNX3 acts as a tumour suppressor by negatively regulating the TEAD-YAP oncogenic complex in gastric carcinogenesis.

  4. Effects of cadmium on cell proliferation, apoptosis, and proto-oncogene expression in zebrafish liver cells

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying Ying; Zhu, Jin Yong; Chan, King Ming, E-mail: kingchan@cuhk.edu.hk

    2014-12-15

    Highlights: • Cd stimulated ZFL cell proliferation with decreasing apoptotic cell numbers. • Cd down regulated p53 and RAD51. • Cd up regulated immediate early cancer genes of GADD45 and growth factors. • Cd promoted tumorigenic effects in ZFL cells. - Abstract: Cadmium (Cd) is one of the major transitional metal that has toxic effects in aquatic organisms and their associated ecosystem; however, its hepatic toxicity and carcinogenicity are not very well characterized. We used a zebrafish liver (ZFL) cell line as a model to investigate the mechanism of Cd-induced toxicity on hepatocytes. Our results showed that Cd can be effectively accumulated in ZFL cells in our exposure experiments. Cell cytotoxicity assays and flow cytometer measurements revealed that Cd{sup 2+} stimulated ZFL cell proliferation with decreasing apoptotic cell numbers indicating potentially tumorigenic effects of Cd in ZFL cells. Gene expression profiles also indicated that Cd downregulated oncogenes p53 and rad51 and upregulated immediate response oncogenes, growth arrest and DNA damage-inducible (gadd45) genes, and growth factors. We also found dramatic changes in the gene expression of c-jun and igf1rb at different exposure time points, supporting the notion that potentially tumorigenic of Cd-is involved in the activation of immediate early genes or genes related to apoptosis in cancer promotion.

  5. Complex oncogenic translocations with gene amplification are initiated by specific DNA breaks in lymphocytes.

    Science.gov (United States)

    Wright, Sarah M; Woo, Yong H; Alley, Travis L; Shirley, Bobbi-Jo; Akeson, Ellen C; Snow, Kathy J; Maas, Sarah A; Elwell, Rachel L; Foreman, Oded; Mills, Kevin D

    2009-05-15

    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. Whereas 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 required for chromosome rearrangements, especially complex lesions, have not been elucidated. Using a mouse model of B-lineage lymphoma, characterized by complicon formation involving the immunoglobulin heavy chain (Igh) locus and the c-myc oncogene, we have now investigated the requirement for specific genomic segments as donors for complex rearrangements. We now show that specific DNA double-strand breaks, occurring within a narrow segment of Igh, are necessary to initiate complicon formation. By contrast, neither specific DNA breaks nor the powerful intronic enhancer Emu are required for complicon-independent oncogenesis. This study is the first to delineate mechanisms of complex versus simple instability and the first to identify specific chromosomal elements required for complex chromosomal aberrations. These findings will illuminate genomic cancer susceptibility and risk factors.

  6. Trefoil factor 3 is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma.

    Science.gov (United States)

    Kannan, Nagarajan; Kang, Jian; Kong, Xiangjun; Tang, Jianzhong; Perry, Jo K; Mohankumar, Kumarasamypet M; Miller, Lance D; Liu, Edison T; Mertani, Hichem C; Zhu, Tao; Grandison, Prudence M; Liu, Dong-Xu; Lobie, Peter E

    2010-12-01

    We report herein that trefoil factor 3 (TFF3) is oncogenic and mediates anti-estrogen resistance in human mammary carcinoma. Forced expression of TFF3 in mammary carcinoma cells increased cell proliferation and survival, enhanced anchorage-independent growth, and promoted migration and invasion. Moreover, forced expression of TFF3 increased tumor size in xenograft models. Conversely, depletion of endogenous TFF3 with small interfering RNA (siRNA) decreased the oncogenicity and invasiveness of mammary carcinoma cells. Neutralization of secreted TFF3 by antibody promoted apoptosis, decreased cell growth in vitro, and arrested mammary carcinoma xenograft growth. TFF3 expression was significantly correlated to decreased survival of estrogen receptor (ER)-positive breast cancer patients treated with tamoxifen. Forced expression of TFF3 in mammary carcinoma cells increased ER transcriptional activity, promoted estrogen-independent growth, and produced resistance to tamoxifen and fulvestrant in vitro and to tamoxifen in xenograft models. siRNA-mediated depletion or antibody inhibition of TFF3 significantly enhanced the efficacy of antiestrogens. Increased TFF3 expression was observed in tamoxifen-resistant (TAMR) cells and antibody inhibition of TFF3 in TAMR cells improved tamoxifen sensitivity. Functional antagonism of TFF3 therefore warrants consideration as a novel therapeutic strategy for mammary carcinoma.

  7. Simultaneous detection, typing and quantitation of oncogenic human papillomavirus by multiplex consensus real-time PCR.

    Science.gov (United States)

    Jenkins, Andrew; Allum, Anne-Gry; Strand, Linda; Aakre, Randi Kersten

    2013-02-01

    A consensus multiplex real-time PCR test (PT13-RT) for the oncogenic human papillomavirus (HPV) types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66 is described. The test targets the L1 gene. Analytical sensitivity is between 4 and 400 GU (genomic units) in the presence of 500 ng of human DNA, corresponding to 75,000 human cells. HPV types are grouped into multiplex groups of 3 or 4 resulting in the use of 4 wells per sample and permitting up to 24 samples per run (including controls) in a standard 96-well real-time PCR instrument. False negative results are avoided by (a) measuring sample DNA concentration to control that sufficient cellular material is present and (b) including HPV type 6 as a homologous internal control in order to detect PCR inhibition or competition from other (non-oncogenic) HPV types. Analysis time from refrigerator to report is 8 h, including 2.5 h hands-on time. Relative to the HC2 test, the sensitivity and specificity were respectively 98% and 83%, the lower specificity being attributable to the higher analytical sensitivity of PT13-RT. To assess type determination comparison was made with a reversed line-blot test. Type concordance was high (κ=0.79) with discrepancies occurring mostly in multiple-positive samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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. The dark and the bright side of Stat3: proto-oncogene and tumor-suppressor.

    Science.gov (United States)

    Ecker, Andrea; Simma, Olivia; Hoelbl, Andrea; Kenner, Lukas; Beug, Hartmut; Moriggl, Richard; Sexl, Veronika

    2009-01-01

    Stat transcription factors have been implicated in tumorigenesis in mice and men. Stat3 and Stat5 are considered powerful proto-oncogenes, whereas Stat1 has been demonstrated to suppress tumor formation. We demonstrate here for the first time that a constitutive active version of Stat3alpha (Stat3alphaC) may also suppress transformation. Mouse embryonic fibroblasts (MEFs) deficient for p53 can be transformed with either c-myc or with rasV12 alone. Interestingly, transformation by c-myc is efficiently suppressed by co-expression of Stat3alphaC, but Stat3alphaC does not interfere with transformation by the rasV12-oncogene. In contrast, transplantation of bone marrow cells expressing Stat3alphaC induces the formation of a highly aggressive T cell leukemia in mice. The leukemic cells invaded multiple organs including lung, heart, salivary glands, liver and kidney. Interestingly, transplanted mice developed a similar leukemia when the bone marrow cells were transduced with Stat3beta, which is also constitutively active when expressed at significant levels. Our experiments demonstrate that Stat3 has both - tumor suppressing and tumor promoting properties.

  11. Identification of anaplastic lymphoma kinase break points and oncogenic mutation profiles in acral/mucosal melanomas.

    Science.gov (United States)

    Niu, Hai-Tao; Zhou, Qi-Ming; Wang, Fang; Shao, Qiong; Guan, Yuan-Xiang; Wen, Xi-Zhi; Chen, Li-Zhen; Feng, Qi-Sheng; Li, Wei; Zeng, Yi-Xin; Zhang, Xiao-Shi

    2013-09-01

    Acral and mucosal melanomas, the two most common subtypes of melanoma in China, exhibit different genetic alterations and biologic behavior compared with other subtypes of melanomas. The purpose of this study was to identify the genetic alterations in patients with acral or mucosal melanomas in southern China. Fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) analysis, polymerase chain reaction (PCR), and quantitative real-time reverse transcriptase PCR (qRT-PCR) were used to assess the anaplastic lymphoma kinase (ALK) break points. Furthermore, a mass spectrometry-based genotyping platform was used to analyze 30 acral melanomas and 28 mucosal melanomas to profile 238 known somatic mutations in 19 oncogenes. ALK break points were identified in four acral cases (6.9%). Eight (13.8%) cases harbored BRAF mutations, six (10.3%) had NRAS mutations, four (6.9%) had KIT mutations, two (3.5%) had EGFR mutations, two (3.5%) had KRAS mutations, two (3.5%) had MET mutations, one (1.7%) had an HRAS mutation, and one (1.7%) had a PIK3CA mutation. Two cases exhibited co-occurring mutations, and one case with a BRAF mutation had a translocation in ALK. This study represents a comprehensive and concurrent analysis of the major recurrent oncogenic mutations involved in melanoma cases from southern China. These data have implications for both clinical trial designs and therapeutic strategies.

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

    Science.gov (United States)

    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.

  13. A block in lineage differentiation of immortal human mammary stem / progenitor cells by ectopically-expressed oncogenes

    Directory of Open Access Journals (Sweden)

    Xiangshan Zhao

    2011-01-01

    Full Text Available Introduction: Emerging evidence suggests a direct role of cancer stem cells (CSCs in the development of breast cancer. In vitro cellular models that recapitulate properties of CSCs are therefore highly desirable. We have previously shown that normal human mammary epithelial cells (hMECs immortalized with human telomerase reverse transcriptase (hTERT possess properties of mammary stem / progenitor cells. Materials and Methods: In the present study, we used this cell system to test the idea that other known hMEC-immortalizing oncogenes (RhoA, HPVE6, HPVE7, p53 mutant, and treatment with g-radiation, share with hTERT, the ability to maintain mammary stem / progenitor cells. Results: The results presented here demonstrate that similar to hMECs immortalized with hTERT, all hMEC cell lines immortalized using various oncogenic strategies express stem / progenitor cell markers. Furthermore, analyses using 2D and 3D culture assays demonstrate that all the immortal cell lines retain their ability to self-renew and to differentiate along the luminal lineage. Remarkably, the stem / progenitor cell lines generated using various oncogenic strategies exhibit a block in differentiation along the myoepithelial lineage, a trait that is retained on hTERT-immortalized stem / progenitors. The inability to differentiate along the myoepithelial lineage could be induced by ectopic mutant p53 expression in hTERT-immortalized hMEC. Conclusions: Our studies demonstrate that stem / progenitor cell characteristics of hMECs are maintained upon immortalization by using various cancer-relevant oncogenic strategies. Oncogene-immortalized hMECs show a block in their ability to differentiate along the myoepithelial lineage. Abrogation of the myoepithelial differentiation potential by a number of distinct oncogenic insults suggests a potential explanation for the predominance of luminal and rarity of myoepithelial breast cancers.

  14. 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.

  15. The cnidarian origin of the proto-oncogenes NF-κB/STAT and WNT-like oncogenic pathway drives the ctenophores (Review).

    Science.gov (United States)

    Sinkovics, Joseph G

    2015-10-01

    The cell survival pathways of the diploblastic early multicellular eukaryotic hosts contain and operate the molecular machinery resembling those of malignantly transformed individual cells of highly advanced multicellular hosts (including Homo). In the present review, the STAT/NF-κB pathway of the cnidarian Nematostella vectensis is compared with that of human tumors (malignant lymphomas, including Reed-Sternberg cells) pointing out similarities, including possible viral initiation in both cases. In the ctenophore genome and proteome, β-catenin gains intranuclear advantages due to a physiologically weak destructive complex in the cytoplasm, and lack of natural inhibitors (the dickkopfs). Thus, a scenario similar to what tumor cells initiate and achieve is presented through several constitutive loss-of-function type mutations in the destructive complex and in the elimination of inhibitors. Vice versa, malignantly transformed individual cells of advanced multicellular hosts assume pheno-genotypic resemblance to cells of unicellular or early multicellular hosts, and presumably to their ancient predecessors, by returning to the semblance of immortality and to the resumption of the state of high degree of resistance to physicochemical insults. Human leukemogenic and oncogenic pathways are presented for comparisons. The supreme bioengineers RNA/DNA complex encoded both the malignantly transformed immortal cell and the human cerebral cortex. The former generates molecules for the immortality of cellular life in the Universe. The latter invents the inhibitors of the process in order to gain control over it.

  16. Expressions of estrogen receptor subtypes and c-met proto-oncogene in endometrial carcinoma and their correlation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Objective To investigate the expressions of estrogen receptor(ER)subtypes and c-met proto-oncogene in human endometrial carcinomas and to assess the clinical significance of ER and c-met in this carcinoma.Methods Reverse transcription PCR(RT-PCR)was used to detect the expressions of ERα,ERβ and c-met proto-oncogene mRNA in 30 samples of endometrial carcinoma and 11 samples of normal endometrium.Results The expression of ERα in endometrial carcinoma(0.70±0.40)was significantly reduced in comparison to that i...

  17. Somatic mutations of the RET proto-oncogene are not required for tumor development in multiple endocrine neoplasia type 2 (MEN 2) gene carriers

    NARCIS (Netherlands)

    Landsvater, RM; deWit, MJ; Zewald, RA; Hofstra, RMW; Buys, CHCM; vanAmstel, HKP; Hoppener, JWM; Lips, CJM

    1996-01-01

    Germ line mutations in one allele of the RET proto-oncogene predispose to the multiple endocrine neoplasia type 2 (MEN 2) syndromes, To investigate whether these inherited mutations alone can cause the development of tumors in vivo (oncogene model) or whether somatic mutations in the homologous RET

  18. Marek’s disease herpesvirus vaccines integrate into chicken host chromosomes yet lack a virus-host phenotype associated with oncogenic transformation

    Science.gov (United States)

    Marek's disease (MD) is a lymphotrophic and oncogenic disease of chickens that can lead to death in susceptible and unimmunized host birds. The causative pathogen, Marek's disease virus (MDV), a highly oncogenic alphaherpesvirus, integrates into host genome near the telomeres during viral latency an...

  19. The Agrobacterium rhizogenes oncogenes rolB and ORF13 increase formation of generative shoots and induce dwarfism in Arabidopsis thaliana (L.) Heynh

    DEFF Research Database (Denmark)

    Kodahl, Nete; Müller, Renate; Lütken, Henrik Vlk

    2016-01-01

    B oncogene yield plants with increased formation of generative shoots, but also result in some degree of premature senescence of vegetative organs. The extreme dwarfism seen in ORF13-lines indicate that this oncogene may be more important in the dwarfing response of plants transformed with the wild type Ri...

  20. THE MYC FAMILY OF ONCOGENES AND THEIR PRESENCE AND IMPORTANCE IN SMALL-CELL LUNG-CARCINOMA AND OTHER TUMOR TYPES

    NARCIS (Netherlands)

    DEVRIES, EGE; MULDER, NH

    1993-01-01

    The myc family of cellular oncogenes, c - myr, N - myc, encodes three highly related, cell cycle specific, nuclear phosphoproteins. All are able to transform primary rat embryo fibroblasts when cotransfected with the c - ras oncogene. Myc family genes am differentially expressed with respect to tiss

  1. 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.

  2. FACTORES PRONOSTICOS DEL CANCER DE MAMA Y ONCOGEN HER2/NEU

    Directory of Open Access Journals (Sweden)

    F.J. Martín Gil

    2006-08-01

    Full Text Available ABSTRACT: PRONOSTIC FACTORS OF BREAST CANCER AND HER2/NEUThe breast cancer constitutes the main cause of death by cancer in women of our country. In spite of the efforts directed in campaigns of precocious detection, the incidence continues increasing in a 1% approximately per year and the rate of mortality stay constant. Therefore it is of great importance to consolidate efforts directed towards the development and use of therapeutic and diagnostic methods. The development of neoplasia is directly related to successive genetic mutations in which cellular oncogenes are involved.It is known that in case of breast cancer the Her2/neu oncogene (Human epidermal growth receptor-2 factor is amplified and/or overexpressed in approximately a 30% of the cases. The knowledge of a positive result for Her2/neu overexpression has an important value in prognosis as it is associated to a greater aggressiveness of the disease. Also, this gene can be an answer marker to certain treatments like trastuzumab. RESUMEN:El cáncer de mama (CM constituye la principal causa de muerte por cáncer en mujeres de nuestro país. A pesar de los esfuerzos dirigidos hacia las campañas de detección precoz, la incidencia sigue aumentando aproximadamente en un 1% por año y la tasa de mortalidad sigue manteniéndose constante.Es por ello de gran importancia aunar esfuerzos dirigidos al desarrollo y utilización de métodos diagnósticos y terapéuticos. El desarrollo de una neoplasia está directamente relacionado con mutaciones genéticas sucesivas en las que están involucrados oncogenes celulares.En el caso del cáncer de mama se sabe que el encogen Her2/neu (Human epidermal growth factor receptor-2 está amplificado y/o sobreexpresado en aproximadamente un 30% de los casos. El conocimiento de la positividad del mismo tiene un importante valor pronóstico asociándose a una mayor agresividad de la enfermedad. Así mismo dicho gen puede ser un marcador predictivo de respuesta

  3. Fatty Acid Synthase: A Metabolic Enzyme and Candidate Oncogene in Prostate Cancer

    Science.gov (United States)

    Migita, Toshiro; Ruiz, Stacey; Fornari, Alessandro; Fiorentino, Michelangelo; Priolo, Carmen; Zadra, Giorgia; Inazuka, Fumika; Grisanzio, Chiara; Palescandolo, Emanuele; Shin, Eyoung; Fiore, Christopher; Xie, Wanling; Kung, Andrew L.; Febbo, Phillip G.; Subramanian, Aravind; Mucci, Lorelei; Ma, Jing; Signoretti, Sabina; Stampfer, Meir; Hahn, William C.; Finn, Stephen

    2009-01-01

    Background Overexpression of the fatty acid synthase (FASN) gene has been implicated in prostate carcinogenesis. We sought to directly assess the oncogenic potential of FASN. Methods We used immortalized human prostate epithelial cells (iPrECs), androgen receptor–overexpressing iPrECs (AR-iPrEC), and human prostate adenocarcinoma LNCaP cells that stably overexpressed FASN for cell proliferation assays, soft agar assays, and tests of tumor formation in immunodeficient mice. Transgenic mice expressing FASN in the prostate were generated to assess the effects of FASN on prostate histology. Apoptosis was evaluated by Hoechst 33342 staining and by fluorescence-activated cell sorting in iPrEC-FASN cells treated with stimulators of the intrinsic and extrinsic pathways of apoptosis (ie, camptothecin and anti-Fas antibody, respectively) or with a small interfering RNA (siRNA) targeting FASN. FASN expression was compared with the apoptotic index assessed by the terminal deoxynucleotidyltransferase-mediated UTP end-labeling method in 745 human prostate cancer samples by using the least squares means procedure. All statistical tests were two-sided. Results Forced expression of FASN in iPrECs, AR-iPrECs, and LNCaP cells increased cell proliferation and soft agar growth. iPrECs that expressed both FASN and androgen receptor (AR) formed invasive adenocarcinomas in immunodeficient mice (12 of 14 mice injected formed tumors vs 0 of 14 mice injected with AR-iPrEC expressing empty vector (P < .001, Fisher exact test); however, iPrECs that expressed only FASN did not. Transgenic expression of FASN in mice resulted in prostate intraepithelial neoplasia, the incidence of which increased from 10% in 8- to 16-week-old mice to 44% in mice aged 7 months or more (P  = .0028, Fisher exact test), but not in invasive tumors. In LNCaP cells, siRNA-mediated silencing of FASN resulted in apoptosis. FASN overexpression protected iPrECs from apoptosis induced by camptothecin but did not

  4. Development of Peptide Nucleic Acid Probes for Detection of the HER2 Oncogene

    Science.gov (United States)

    Song, Young K.; Evangelista, Jennifer; Aschenbach, Konrad; Johansson, Peter; Wen, Xinyu; Chen, Qingrong; Lee, Albert; Hempel, Heidi; Gheeya, Jinesh S.; Getty, Stephanie; Gomez, Romel; Khan, Javed

    2013-01-01

    Peptide nucleic acids (PNAs) have gained much interest as molecular recognition tools in biology, medicine and chemistry. This is due to high hybridization efficiency to complimentary oligonucleotides and stability of the duplexes with RNA or DNA. We have synthesized 15/16-mer PNA probes to detect the HER2 mRNA. The performance of these probes to detect the HER2 target was evaluated by fluorescence imaging and fluorescence bead assays. The PNA probes have sufficiently discriminated between the wild type HER2 target and the mutant target with single base mismatches. Furthermore, the probes exhibited excellent linear concentration dependence between 0.4 to 400 fmol for the target gene. The results demonstrate potential application of PNAs as diagnostic probes with high specificity for quantitative measurements of amplifications or over-expressions of oncogenes. PMID:23593123

  5. Development of peptide nucleic acid probes for detection of the HER2 oncogene.

    Directory of Open Access Journals (Sweden)

    Belhu Metaferia

    Full Text Available Peptide nucleic acids (PNAs have gained much interest as molecular recognition tools in biology, medicine and chemistry. This is due to high hybridization efficiency to complimentary oligonucleotides and stability of the duplexes with RNA or DNA. We have synthesized 15/16-mer PNA probes to detect the HER2 mRNA. The performance of these probes to detect the HER2 target was evaluated by fluorescence imaging and fluorescence bead assays. The PNA probes have sufficiently discriminated between the wild type HER2 target and the mutant target with single base mismatches. Furthermore, the probes exhibited excellent linear concentration dependence between 0.4 to 400 fmol for the target gene. The results demonstrate potential application of PNAs as diagnostic probes with high specificity for quantitative measurements of amplifications or over-expressions of oncogenes.

  6. Convergent mutations and kinase fusions lead to oncogenic STAT3 activation in anaplastic large cell lymphoma.

    Science.gov (United States)

    Crescenzo, Ramona; Abate, Francesco; Lasorsa, Elena; Tabbo', Fabrizio; Gaudiano, Marcello; Chiesa, Nicoletta; Di Giacomo, Filomena; Spaccarotella, Elisa; Barbarossa, Luigi; Ercole, Elisabetta; Todaro, Maria; Boi, Michela; Acquaviva, Andrea; Ficarra, Elisa; Novero, Domenico; Rinaldi, Andrea; Tousseyn, Thomas; Rosenwald, Andreas; Kenner, Lukas; Cerroni, Lorenzo; Tzankov, Alexander; Ponzoni, Maurilio; Paulli, Marco; Weisenburger, Dennis; Chan, Wing C; Iqbal, Javeed; Piris, Miguel A; Zamo', Alberto; Ciardullo, Carmela; Rossi, Davide; Gaidano, Gianluca; Pileri, Stefano; Tiacci, Enrico; Falini, Brunangelo; Shultz, Leonard D; Mevellec, Laurence; Vialard, Jorge E; Piva, Roberto; Bertoni, Francesco; Rabadan, Raul; Inghirami, Giorgio

    2015-04-13

    A systematic characterization of the genetic alterations driving ALCLs has not been performed. By integrating massive sequencing strategies, we provide a comprehensive characterization of driver genetic alterations (somatic point mutations, copy number alterations, and gene fusions) in ALK(-) ALCLs. We identified activating mutations of JAK1 and/or STAT3 genes in ∼20% of 88 [corrected] ALK(-) ALCLs and demonstrated that 38% of systemic ALK(-) ALCLs displayed double lesions. Recurrent chimeras combining a transcription factor (NFkB2 or NCOR2) with a tyrosine kinase (ROS1 or TYK2) were also discovered in WT JAK1/STAT3 ALK(-) ALCL. All these aberrations lead to the constitutive activation of the JAK/STAT3 pathway, which was proved oncogenic. Consistently, JAK/STAT3 pathway inhibition impaired cell growth in vitro and in vivo.

  7. Neem Limonoids as Anticancer Agents: Modulation of Cancer Hallmarks and Oncogenic Signaling.

    Science.gov (United States)

    Nagini, Siddavaram

    2014-01-01

    Neem (Azadirachta indica A. Juss) is one of the most versatile medicinal plants, widely distributed in the Indian subcontinent. Neem is a rich source of limonoids that are endowed with potent medicinal properties predominantly antioxidant, anti-inflammatory, and anticancer activities. Azadirachtin, gedunin, and nimbolide are more extensively investigated relative to other neem limonoids. Accumulating evidence indicates that the anticancer effects of neem limonoids are mediated through the inhibition of hallmark capabilities of cancer such as cell proliferation, apoptosis evasion, inflammation, invasion, and angiogenesis. The neem limonoids have been demonstrated to target oncogenic signaling kinases and transcription factors chiefly, NF-κB, Wnt/β-catenin, PI3K/Akt, MAPK, and JAK/STAT signaling pathways. Neem limonoids that target multiple pathways that are aberrant in cancer are ideal candidates for cancer chemoprevention and therapy. © 2014 Elsevier Inc. All rights reserved.

  8. Oncogenic Alternative Splicing Switches: Role in Cancer Progression and Prospects for Therapy

    Directory of Open Access Journals (Sweden)

    Serena Bonomi

    2013-01-01

    Full Text Available Alterations in the abundance or activities of alternative splicing regulators generate alternatively spliced variants that contribute to multiple aspects of tumor establishment, progression and resistance to therapeutic treatments. Notably, many cancer-associated genes are regulated through alternative splicing suggesting a significant role of this post-transcriptional regulatory mechanism in the production of oncogenes and tumor suppressors. Thus, the study of alternative splicing in cancer might provide a better understanding of the malignant transformation and identify novel pathways that are uniquely relevant to tumorigenesis. Understanding the molecular underpinnings of cancer-associated alternative splicing isoforms will not only help to explain many fundamental hallmarks of cancer, but will also offer unprecedented opportunities to improve the efficacy of anti-cancer treatments.

  9. Oncogenic BRAF(V600E Induces Clastogenesis and UVB Hypersensitivity

    Directory of Open Access Journals (Sweden)

    Dennis A. Simpson

    2015-06-01

    Full Text Available The oncogenic BRAF(V600E mutation is common in melanomas as well as moles. The roles that this mutation plays in the early events in the development of melanoma are poorly understood. This study demonstrates that expression of BRAF(V600E is not only clastogenic, but synergizes for clastogenesis caused by exposure to ultraviolet radiation in the 300 to 320 nM (UVB range. Expression of BRAF(V600E was associated with induction of Chk1 pS280 and a reduction in chromatin remodeling factors BRG1 and BAF180. These alterations in the Chk1 signaling pathway and SWI/SNF chromatin remodeling pathway may contribute to the clastogenesis and UVB sensitivity. These results emphasize the importance of preventing sunburns in children with developing moles.

  10. The HPV E6/E7 Oncogenes: Key Factors for Viral Carcinogenesis and Therapeutic Targets.

    Science.gov (United States)

    Hoppe-Seyler, Karin; Bossler, Felicitas; Braun, Julia A; Herrmann, Anja L; Hoppe-Seyler, Felix

    2017-08-17

    Human papillomavirus (HPV)-induced cancers are expected to remain a major health problem worldwide for decades. The growth of HPV-positive cancer cells depends on the sustained expression of the viral E6 and E7 oncogenes which act in concert with still poorly defined cellular alterations. E6/E7 constitute attractive therapeutic targets since E6/E7 inhibition rapidly induces senescence in HPV-positive cancer cells. This cellular response is linked to the reconstitution of the antiproliferative p53 and pRb pathways, and to prosenescent mTOR signaling. Hypoxic HPV-positive cancer cells could be a major obstacle for treatment strategies targeting E6/E7 since they downregulate E6/E7 but evade senescence through hypoxia-induced mTOR impairment. Prospective E6/E7 inhibitors may therefore benefit from a combination with treatment strategies directed against hypoxic tumor cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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.

  13. Dedifferentiation of neurons and astrocytes by oncogenes can induce gliomas in mice.

    Science.gov (United States)

    Friedmann-Morvinski, Dinorah; Bushong, Eric A; Ke, Eugene; Soda, Yasushi; Marumoto, Tomotoshi; Singer, Oded; Ellisman, Mark H; Verma, Inder M

    2012-11-23

    Glioblastoma multiforme (GBM) is the most common and aggressive malignant primary brain tumor in humans. Here we show that gliomas can originate from differentiated cells in the central nervous system (CNS), including cortical neurons. Transduction by oncogenic lentiviral vectors of neural stem cells (NSCs), astrocytes, or even mature neurons in the brains of mice can give rise to malignant gliomas. All the tumors, irrespective of the site of lentiviral vector injection (the initiating population), shared common features of high expression of stem or progenitor markers and low expression of differentiation markers. Microarray analysis revealed that tumors of astrocytic and neuronal origin match the mesenchymal GBM subtype. We propose that most differentiated cells in the CNS upon defined genetic alterations undergo dedifferentiation to generate a NSC or progenitor state to initiate and maintain the tumor progression, as well as to give rise to the heterogeneous populations observed in malignant gliomas.

  14. 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.

  15. [Advances Research on C-MYC Proto-oncogene in Multiple Myeloma -Review].

    Science.gov (United States)

    Huang, He; Guo, Wen-Jian; Yao, Ron-Xin

    2016-08-01

    Multiple myeloma(MM) as one of the most common tumors of hmatologic system, is characterized by malignant proliferation of plasma cells, and the chemotherapy is the main therapeutic method. MM is an incurable disease because of drug-resistance of MM cells. Although the pathogenesis of MM remains unknown, the chromosome abnormalities exit in half of the patients, particularly the highly expressed gene C-MYC. Furthermore, plenty of clinical researches indicated a high expression level of C-MYC implied worse progression and/or poor prognosis of MM. Recently, the work exploiting the compounds targeting MYC has made substantial progress, even in the MM therapy. In this article, briefly the recent advances of the research on C-MYC proto-oncogene in multiple myeloma are reviewed.

  16. 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.

  17. Investigating the Expression of Oncogenic and Tumor Suppressive MicroRNA in DLBCL.

    Science.gov (United States)

    Handal, Brian; Enlow, Rossanna; Lara, Daniel; Bailey, Mark; Vega, Francisco; Hu, Peter; Lennon, Alan

    2013-01-01

    Diffuse Large B-cell Lymphoma (DLBCL) is the most common form of lymphoma, accounting for 40 percent of newly diagnosed cases each year. DLBCL is an aggressive abnormal growth of tissue characterized by the accumulation of abnormal B-lymphocytes in the lymphatics of affected individuals. The goal of this study was to analyze microRNA (miRNA) as an alternative method of diagnosis and treatment for patients affected with the observed cancer. MiRNAs are small, non-coding, endogenous RNA that control gene expression at the post-transcriptional level. Emerging evidence suggests that miRNA-mediated gene regulation has a functional role in cancer and could prove to be crucial targets for therapeutic intervention. Here, we provide a quantitative study on the expression of a diverse class of oncogenic and tumor suppressive miRNA that have shown to regulate oncoproteins involved in differentiation, proliferation, and/or apoptosis.

  18. [Diagnostic value of BRAFV600E and RET/PTC oncogenes in thyroid nodule aspirates].

    Science.gov (United States)

    Guerra, Anna; Carrano, Mario; Angrisani, Elisabetta; Vitale, Mario

    2013-01-01

    Fine-needle aspiration cytology (FNC) is the primary means to distinguish benign form malignant nodules. Aim of this study is to evaluate the diagnostic value of BRAF(V600E) and RET/PTC oncogenes in a large cohort of thyroid nodules with inconclusive FNC. We searched for BRAF(V600E) and RET/PTC in 299 thyroid nodule aspirates then removed by surgery. RET/PTC demonstrated a poor specificity. The search for BRAF(V600E) demonstrated to be useful in 25 cases, identifying a PTC in 2 false negative, 2 inadequate, 11 indeterminate and 10 suspicious FNC. Detection of BRAF(V600E) revealed to be a useful tool to refine inconclusive cytology.

  19. Oncogenic potential of Human Papillomavirus (HPV and its relation with cervical cancer

    Directory of Open Access Journals (Sweden)

    Idrees Muhammad

    2011-06-01

    Full Text Available Abstract Human Papillomavirus (HPV is the most common cause of cervical cancer. Cervical cancer being the second most common cancer after lung cancer, affecting women of different age groups; has a prevalence of about 20% in young sexually active women. Among different types of HPV, HPV16 the major strain causing this cancer and is sexually transmitted had been unnoticed for decades. Keeping in mind the multiple risk factors related with cervical cancer such as early age sexual activities, teenage pregnancies, smoking, use of oral contraceptives, having multiple sex partners, hormone replacement therapies and various other unknown factors lead to the onset of the disease. Awareness for various diagnostic procedures such as Pap smears screening prove to be an effective way in eradicating the oncogenic potential of HPV.

  20. Preliminary Study on c-Ha-ras Oncogene Mutations in Hydatidiform Mole Tissues

    Institute of Scientific and Technical Information of China (English)

    王芳; 谭运年; 陈碧; 李英勇; 康旭

    2001-01-01

    Objective To study the presence of c-Ha-fas oncogene mutations in hydatidiform mole (HM) tissues and to further explore its relationship with mole's malignancy Materials & methods c-Ha-ras codon 12 mutation was detected in invasive and noninvasive HM by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).Results c-Ha-fas codon 12 mutation was detected in 7 samples (53. 85%) of 13 invasive HM and 8 samples (26. 67%) in 30 non-invasive HM. c-Ha-ras mutations also showed loss of wild-type c-Ha-fas. No mutation in control group was observed.Conclusion The tendency of c-Ha-ras codon 12 mutation may be related with a higher invasive degree of HM.

  1. Genetic and pharmacological disruption of the TEAD-YAP complex suppresses the oncogenic activity of YAP.

    Science.gov (United States)

    Liu-Chittenden, Yi; Huang, Bo; Shim, Joong Sup; Chen, Qian; Lee, Se-Jin; Anders, Robert A; Liu, Jun O; Pan, Duojia

    2012-06-15

    The Drosophila TEAD ortholog Scalloped is required for Yki-mediated overgrowth but is largely dispensable for normal tissue growth, suggesting that its mammalian counterpart may be exploited for selective inhibition of oncogenic growth driven by YAP hyperactivation. Here we test this hypothesis genetically and pharmacologically. We show that a dominant-negative TEAD molecule does not perturb normal liver growth but potently suppresses hepatomegaly/tumorigenesis resulting from YAP overexpression or Neurofibromin 2 (NF2)/Merlin inactivation. We further identify verteporfin as a small molecule that inhibits TEAD-YAP association and YAP-induced liver overgrowth. These findings provide proof of principle that inhibiting TEAD-YAP interactions is a pharmacologically viable strategy against the YAP oncoprotein.

  2. Genetic and pharmacological disruption of the TEAD–YAP complex suppresses the oncogenic activity of YAP

    Science.gov (United States)

    Liu-Chittenden, Yi; Huang, Bo; Shim, Joong Sup; Chen, Qian; Lee, Se-Jin; Anders, Robert A.; Liu, Jun O.; Pan, Duojia

    2012-01-01

    The Drosophila TEAD ortholog Scalloped is required for Yki-mediated overgrowth but is largely dispensable for normal tissue growth, suggesting that its mammalian counterpart may be exploited for selective inhibition of oncogenic growth driven by YAP hyperactivation. Here we test this hypothesis genetically and pharmacologically. We show that a dominant-negative TEAD molecule does not perturb normal liver growth but potently suppresses hepatomegaly/tumorigenesis resulting from YAP overexpression or Neurofibromin 2 (NF2)/Merlin inactivation. We further identify verteporfin as a small molecule that inhibits TEAD–YAP association and YAP-induced liver overgrowth. These findings provide proof of principle that inhibiting TEAD–YAP interactions is a pharmacologically viable strategy against the YAP oncoprotein. PMID:22677547

  3. A single oncogenic enhancer rearrangement causes concomitant EVI1 and GATA2 deregulation in leukemia.

    Science.gov (United States)

    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

    2014-04-10

    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 genomics and genome-engineering, we demonstrate that both 3q rearrangements reposition a distal GATA2 enhancer to ectopically activate EVI1 and simultaneously confer GATA2 functional haploinsufficiency, previously identified as the cause of sporadic familial AML/MDS and MonoMac/Emberger syndromes. Genomic excision of the ectopic enhancer restored EVI1 silencing and led to growth inhibition and differentiation of AML cells, which could be replicated by pharmacologic BET inhibition. Our data show that structural rearrangements involving the chromosomal repositioning of a single enhancer can cause deregulation of two unrelated distal genes, with cancer as the outcome.

  4. Computational drugs repositioning identifies inhibitors of oncogenic PI3K/AKT/P70S6K-dependent pathways among FDA-approved compounds

    Science.gov (United States)

    Carrella, Diego; Manni, Isabella; Tumaini, Barbara; Dattilo, Rosanna; Papaccio, Federica; Mutarelli, Margherita; Sirci, Francesco; Amoreo, Carla A.; Mottolese, Marcella; Iezzi, Manuela; Ciolli, Laura; Aria, Valentina; Bosotti, Roberta; Isacchi, Antonella; Loreni, Fabrizio; Bardelli, Alberto; Avvedimento, Vittorio E.; di Bernardo, Diego; Cardone, Luca

    2016-01-01

    The discovery of inhibitors for oncogenic signalling pathways remains a key focus in modern oncology, based on personalized and targeted therapeutics. Computational drug repurposing via the analysis of FDA-approved drug network is becoming a very effective approach to identify therapeutic opportunities in cancer and other human diseases. Given that gene expression signatures can be associated with specific oncogenic mutations, we tested whether a “reverse” oncogene-specific signature might assist in the computational repositioning of inhibitors of oncogenic pathways. As a proof of principle, we focused on oncogenic PI3K-dependent signalling, a molecular pathway frequently driving cancer progression as well as raising resistance to anticancer-targeted therapies. We show that implementation of “reverse” oncogenic PI3K-dependent transcriptional signatures combined with interrogation of drug networks identified inhibitors of PI3K-dependent signalling among FDA-approved compounds. This led to repositioning of Niclosamide (Niclo) and Pyrvinium Pamoate (PP), two anthelmintic drugs, as inhibitors of oncogenic PI3K-dependent signalling. Niclo inhibited phosphorylation of P70S6K, while PP inhibited phosphorylation of AKT and P70S6K, which are downstream targets of PI3K. Anthelmintics inhibited oncogenic PI3K-dependent gene expression and showed a cytostatic effect in vitro and in mouse mammary gland. Lastly, PP inhibited the growth of breast cancer cells harbouring PI3K mutations. Our data indicate that drug repositioning by network analysis of oncogene-specific transcriptional signatures is an efficient strategy for identifying oncogenic pathway inhibitors among FDA-approved compounds. We propose that PP and Niclo should be further investigated as potential therapeutics for the treatment of tumors or diseases carrying the constitutive activation of the PI3K/P70S6K signalling axis. PMID:27542212

  5. 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.

  6. Expression of hepatocyte growth factor and the proto-oncogenic receptor c-Met in canine osteosarcoma

    NARCIS (Netherlands)

    Fieten, H|info:eu-repo/dai/nl/314112596; Spee, B|info:eu-repo/dai/nl/304830925; Ijzer, J|info:eu-repo/dai/nl/304839663; Kik, M J|info:eu-repo/dai/nl/080432565; Penning, L C|info:eu-repo/dai/nl/110369181; Kirpensteijn, J|info:eu-repo/dai/nl/189846992

    Hepatocyte growth factor (HGF) and the proto-oncogenic receptor c-Met are implicated in growth, invasion, and metastasis in human cancer. Little information is available on the expression and role of both gene products in canine osteosarcoma. We hypothesized that the expression of c-Met is

  7. 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.

  8. An integrative approach unveils FOSL1 as an oncogene vulnerability in KRAS-driven lung and pancreatic cancer

    DEFF Research Database (Denmark)

    Vallejo, Adrian; Perurena, Naiara; Guruceaga, Elisabet

    2017-01-01

    KRAS mutated tumours represent a large fraction of human cancers, but the vast majority remains refractory to current clinical therapies. Thus, a deeper understanding of the molecular mechanisms triggered by KRAS oncogene may yield alternative therapeutic strategies. Here we report the identifica...

  9. p53-independent upregulation of miR-34a during oncogene-induced senescence represses MYC

    DEFF Research Database (Denmark)

    Christoffersen, N R; Shalgi, R; Frankel, L B

    2010-01-01

    , upregulation of miR-34a is mediated by the ETS family transcription factor, ELK1. During senescence, miR-34a targets the important proto-oncogene MYC and our data suggest that miR-34a thereby coordinately controls a set of cell cycle regulators. Hence, in addition to its integration in the p53 pathway, we show...

  10. A rare haplotype of the RET proto-oncogene is a risk-modifying allele in Hirschsprung disease

    NARCIS (Netherlands)

    Griseri, P; Pesce, B; Patrone, G; Osinga, J; Puppo, F; Sancandi, M; Hofstra, R; Romeo, G; Ravazzolo, R; Devoto, M; Ceccherini, [No Value

    2002-01-01

    Hirschsprung disease (HSCR) is a common genetic disorder characterized by intestinal obstruction secondary to enteric aganglionosis. HSCR demonstrates a complex pattern of inheritance, with the RET proto-oncogene acting as a major gene and with several additional susceptibility loci related to the R

  11. E6/E7 oncogenes increase and tumor suppressors decrease the proportion of self-renewing neural progenitor cells.

    Science.gov (United States)

    Piltti, K; Kerosuo, L; Hakanen, J; Eriksson, M; Angers-Loustau, A; Leppä, S; Salminen, M; Sariola, H; Wartiovaara, K

    2006-08-10

    Many if not most tissues need a controlled number of stem cells to maintain normal function. Cancer can be seen as a process of disturbed tissue homeostasis, in which too many cells have or acquire too primitive identity. Here we measured how oncogenes and tumour suppressors affect the differentiation capacity, proportion and characteristics of progenitor cells in a model tissue. Neural progenitor cells (NPCs) were exposed to human papilloma virus E6, E7 or E6/E7 oncogenes, which degrade tumour suppressors p53 and pRb family members, respectively. E6/E7-expressing or p53-/- NPCs were able to differentiate, but simultaneously retained high capacity for self-renewal, proliferation, ability to remain multipotent in conditions promoting differentiation and showed delayed cell cycle exit. These functions were mediated through p53 and pRb family, and involved MEK-ERK signalling. Decreased amount of p53 increased self-renewal and proliferation, whereas pRb affected only proliferation. Our results suggest that the oncogenes increase whereas p53 and pRb family tumour suppressors decrease the number and proportion of progenitor cells. These findings provide one explanation how oncogenes and tumour suppressors control tissue homeostasis and highlight their importance in stem cell self- renewal, linked both to cancer and life-long tissue turnover.

  12. Identification of cellular targets for the human papillomavirus E6 and E7 oncogenes by RNA interference and transcriptome analyses.

    Science.gov (United States)

    Kuner, Ruprecht; Vogt, Markus; Sultmann, Holger; Buness, Andreas; Dymalla, Susanne; Bulkescher, Julia; Fellmann, Mark; Butz, Karin; Poustka, Annemarie; Hoppe-Seyler, Felix

    2007-11-01

    Specific types of human papillomaviruses (HPVs) cause cervical cancer, the second most common tumor in women worldwide. Both cellular transformation and the maintenance of the oncogenic phenotype of HPV-positive tumor cells are linked to the expression of the viral E6 and E7 oncogenes. To identify downstream cellular target genes for the viral oncogenes, we silenced endogenous E6 and E7 expression in HPV-positive HeLa cells by RNA interference (RNAi). Subsequently, we assessed changes of the cellular transcriptome by genome-wide microarray analysis. We identified 648 genes, which were either downregulated (360 genes) or upregulated (288 genes), upon inhibition of E6/E7 expression. A large fraction of these genes is involved in tumor-relevant processes, such as apoptosis control, cell cycle regulation, or spindle formation. Others may represent novel cellular targets for the HPV oncogenes, such as a large group of C-MYC-associated genes involved in RNA processing and splicing. Comparison with published microarray data revealed a substantial concordance between the genes repressed by RNAi-mediated E6/E7 silencing in HeLa cells and genes reported to be upregulated in HPV-positive cervical cancer biopsies.

  13. 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.

  14. Molecular Process Producing Oncogene Fusion in Lung Cancer Cells by Illegitimate Repair of DNA Double-Strand Breaks

    Directory of Open Access Journals (Sweden)

    Yoshitaka Seki

    2015-09-01

    Full Text Available Constitutive activation of oncogenes by fusion to partner genes, caused by chromosome translocation and inversion, is a critical genetic event driving lung carcinogenesis. Fusions of the tyrosine kinase genes ALK (anaplastic lymphoma kinase, ROS1 (c-ros oncogene 1, or RET (rearranged during transfection occur in 1%–5% of lung adenocarcinomas (LADCs and their products constitute therapeutic targets for kinase inhibitory drugs. Interestingly, ALK, RET, and ROS1 fusions occur preferentially in LADCs of never- and light-smokers, suggesting that the molecular mechanisms that cause these rearrangements are smoking-independent. In this study, using previously reported next generation LADC genome sequencing data of the breakpoint junction structures of chromosome rearrangements that cause oncogenic fusions in human cancer cells, we employed the structures of breakpoint junctions of ALK, RET, and ROS1 fusions in 41 LADC cases as “traces” to deduce the molecular processes of chromosome rearrangements caused by DNA double-strand breaks (DSBs and illegitimate joining. We found that gene fusion was produced by illegitimate repair of DSBs at unspecified sites in genomic regions of a few kb through DNA synthesis-dependent or -independent end-joining pathways, according to DSB type. This information will assist in the understanding of how oncogene fusions are generated and which etiological factors trigger them.

  15. 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.

  16. 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.

  17. Targeting oncogene expression to endothelial cells induces proliferation of the myelo-erythroid lineage by repressing the Notch pathway.

    Science.gov (United States)

    Alghisi, E; Distel, M; Malagola, M; Anelli, V; Santoriello, C; Herwig, L; Krudewig, A; Henkel, C V; Russo, D; Mione, M C

    2013-11-01

    Human oncogenes involved in the development of hematological malignancies have been widely used to model experimental leukemia. However, models of myeloid leukemia rarely reproduce the human disease in full, due to genetic complexity or to difficulties in targeting leukemia initiating cells. Here, we used a zebrafish genetic model to induce the expression of oncogenic RAS in endothelial cells, including the hemogenic endothelium of the dorsal aorta that generates hematopoietic cells, and observed the development of a myelo-erythroid proliferative disorder. In larvae, the phenotype is characterized by disruption of the vascular system and prominent expansion of the caudal hematopoietic tissue. In few surviving juveniles, increased number of immature hematopoietic cells and arrest of myeloid maturation was found in kidney marrow. Peripheral blood showed increased erythroblasts and myeloid progenitors. We found that the abnormal phenotype is associated with a downregulation of the Notch pathway, whereas overexpressing an activated form of Notch together with the oncogene prevents the expansion of the myelo-erythroid compartment. This study identifies the downregulation of the Notch pathway following an oncogenic event in the hemogenic endothelium as an important step in the pathogenesis of myelo-erythroid disorders and describes a number of potential effectors of this transformation.

  18. 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...

  19. The 5T mouse multiple myeloma model: Absence of c-myc oncogene rearrangement in early transplant generations

    NARCIS (Netherlands)

    Radl, J.; Punt, Y.A.; Enden-Vieveen, M.H.M. van den; Bentvelzen, P.A.J.; Bakkus, M.H.C.; Akker T., W. van den; Benner, R.

    1990-01-01

    Consistent chromosomal translocations involving the c-myc cellular oncogene and one of the three immunoglobulin loci are typical for human Burkitt's lymphoma, induced mouse plasmacytoma (MPC) and spontaneously arising rat immunocytoma (RIC). Another plasma cell malignancy, multiple myeloma (MM), ari

  20. 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.

  1. The ret/ptc1 oncogene is activated in familial adenomatous polyposis-associated thyroid papillary carcinomas.

    Science.gov (United States)

    Cetta, F; Chiappetta, G; Melillo, R M; Petracci, M; Montalto, G; Santoro, M; Fusco, A

    1998-03-01

    Familial adenomatous polyposis (FAP) is caused by germ-line mutations of the apc gene, and it is associated with an increased risk of developing papillary thyroid carcinomas. We have previously reported that a significant fraction of sporadic human papillary thyroid carcinomas is characterized by gene rearrangements affecting the ret protooncogene. These rearrangements generate chimeric transforming oncogenes designated ret/ptc. By a combined immunohistochemical and RT-PCR approach, we analyzed, for ret/ptc oncogene activation, papillary thyroid carcinomas occurred in two FAP kindreds, both showing typical apc gene mutations. Kindred 1 had seven members affected by FAP, and among these, three patients showed papillary thyroid carcinomas. Kindred 2 had two patients, mother and daughter, affected by colonic polyposis; the 20-yr-old daughter showed also a papillary carcinoma. Here we report that ret/ptc1 oncogene was activated in two of the three papillary carcinomas of FAP kindred 1 and in the papillary carcinoma of FAP kindred 2. These findings document that loss of function of apc coexists with gain of function of ret in some papillary thyroid carcinomas, suggesting that ret/ptc1 oncogene activation could be a progression step in the development of FAP-associated thyroid tumors.

  2. Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL.

    Science.gov (United States)

    Della Gatta, Giusy; Palomero, Teresa; Perez-Garcia, Arianne; Ambesi-Impiombato, Alberto; Bansal, Mukesh; Carpenter, Zachary W; De Keersmaecker, Kim; Sole, Xavier; Xu, Luyao; Paietta, Elisabeth; Racevskis, Janis; Wiernik, Peter H; Rowe, Jacob M; Meijerink, Jules P; Califano, Andrea; Ferrando, Adolfo A

    2012-02-26

    The TLX1 and TLX3 transcription factor oncogenes have a key role in the pathogenesis of T cell acute lymphoblastic leukemia (T-ALL). Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This systems biology analysis defined T cell leukemia homeobox 1 (TLX1) and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, a network structure analysis of this hierarchical network identified RUNX1 as a key mediator of the T-ALL induced by TLX1 and TLX3 and predicted a tumor-suppressor role for RUNX1 in T cell transformation. Consistent with these results, we identified recurrent somatic loss-of-function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 at the top of an oncogenic transcriptional network controlling leukemia development, show the power of network analyses to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor-suppressor gene in T-ALL.

  3. 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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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. LIN28 Expression in malignant germ cell tumors downregulates let-7 and increases oncogene levels.

    Science.gov (United States)

    Murray, Matthew J; Saini, Harpreet K; Siegler, Charlotte A; Hanning, Jennifer E; Barker, Emily M; van Dongen, Stijn; Ward, Dawn M; Raby, Katie L; Groves, Ian J; Scarpini, Cinzia G; Pett, Mark R; Thornton, Claire M; Enright, Anton J; Nicholson, James C; Coleman, Nicholas

    2013-08-01

    Despite their clinicopathologic heterogeneity, malignant germ cell tumors (GCT) share molecular abnormalities that are likely to be functionally important. In this study, we investigated the potential significance of downregulation of the let-7 family of tumor suppressor microRNAs in malignant GCTs. Microarray results from pediatric and adult samples (n = 45) showed that LIN28, the negative regulator of let-7 biogenesis, was abundant in malignant GCTs, regardless of patient age, tumor site, or histologic subtype. Indeed, a strong negative correlation existed between LIN28 and let-7 levels in specimens with matched datasets. Low let-7 levels were biologically significant, as the sequence complementary to the 2 to 7 nt common let-7 seed "GAGGUA" was enriched in the 3' untranslated regions of mRNAs upregulated in pediatric and adult malignant GCTs, compared with normal gonads (a mixture of germ cells and somatic cells). We identified 27 mRNA targets of let-7 that were upregulated in malignant GCT cells, confirming significant negative correlations with let-7 levels. Among 16 mRNAs examined in a largely independent set of specimens by quantitative reverse transcription PCR, we defined negative-associations with let-7e levels for six oncogenes, including MYCN, AURKB, CCNF, RRM2, MKI67, and C12orf5 (when including normal control tissues). Importantly, LIN28 depletion in malignant GCT cells restored let-7 levels and repressed all of these oncogenic let-7 mRNA targets, with LIN28 levels correlating with cell proliferation and MYCN levels. Conversely, ectopic expression of let-7e was sufficient to reduce proliferation and downregulate MYCN, AURKB, and LIN28, the latter via a double-negative feedback loop. We conclude that the LIN28/let-7 pathway has a critical pathobiologic role in malignant GCTs and therefore offers a promising target for therapeutic intervention. ©2013 AACR.

  7. 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.

  8. Variable expression of PIK3R3 and PTEN in Ewing Sarcoma impacts oncogenic phenotypes.

    Directory of Open Access Journals (Sweden)

    Brian F Niemeyer

    Full Text Available Ewing Sarcoma is an aggressive malignancy of bone and soft tissue affecting children and young adults. Ewing Sarcoma is driven by EWS/Ets fusion oncoproteins, which cause widespread alterations in gene expression in the cell. Dysregulation of receptor tyrosine kinase signaling, particularly involving IGF-1R, also plays an important role in Ewing Sarcoma pathogenesis. However, the basis of this dysregulation, including the relative contribution of EWS/Ets-dependent and independent mechanisms, is not well understood. In the present study, we identify variable expression of two modifiers of PI3K signaling activity, PIK3R3 and PTEN, in Ewing Sarcoma, and examine the consequences of this on PI3K pathway regulation and oncogenic phenotypes. Our findings indicate that PIK3R3 plays a growth-promotional role in Ewing Sarcoma, but suggest that this role is not strictly dependent on regulation of PI3K pathway activity. We further show that expression of PTEN, a well-established, potent tumor suppressor, is lost in a subset of Ewing Sarcomas, and that this loss strongly correlates with high baseline PI3K pathway activity in cell lines. In support of functional importance of PTEN loss in Ewing Sarcoma, we show that re-introduction of PTEN into two different PTEN-negative Ewing Sarcoma cell lines results in downregulation of PI3K pathway activity, and sensitization to the IGF-1R small molecule inhibitor OSI-906. Our findings also suggest that PTEN levels may contribute to sensitivity of Ewing Sarcoma cells to the microtubule inhibitor vincristine, a relevant chemotherapeutic agent in this cancer. Our studies thus identify PIK3R3 and PTEN as modifiers of oncogenic phenotypes in Ewing Sarcoma, with potential clinical implications.

  9. Salivary gland tumors in transgenic mice with targeted PLAG1 proto-oncogene overexpression.

    Science.gov (United States)

    Declercq, Jeroen; Van Dyck, Frederik; Braem, Caroline V; Van Valckenborgh, Isabelle C; Voz, Marianne; Wassef, Michel; Schoonjans, Luc; Van Damme, Boudewijn; Fiette, Laurence; Van de Ven, Wim J M

    2005-06-01

    Pleomorphic adenoma gene 1 (PLAG1) proto-oncogene overexpression is implicated in various human neoplasias, including salivary gland pleomorphic adenomas. To further assess the oncogenic capacity of PLAG1, two independent PLAG1 transgenic mouse strains were established, PTMS1 and PTMS2, in which activation of PLAG1 overexpression is Cre mediated. Crossbreeding of PTMS1 or PTMS2 mice with MMTV-Cre transgenic mice was done to target PLAG1 overexpression to salivary and mammary glands, in the P1-Mcre/P2-Mcre offspring. With a prevalence of 100% and 6%, respectively, P1-Mcre and P2-Mcre mice developed salivary gland tumors displaying various pleomorphic adenoma features. Moreover, histopathologic analysis of salivary glands of 1-week-old P1-Mcre mice pointed at early tumoral stages in epithelial structures. Malignant characteristics in the salivary gland tumors and frequent lung metastases were found in older tumor-bearing mice. PLAG1 overexpression was shown in all tumors, including early tumoral stages. The tumors revealed an up-regulation of the expression of two distinct, imprinted gene clusters (i.e., Igf2/H19 and Dlk1/Gtl2). With a latency period of about 1 year, 8% of the P2-Mcre mice developed mammary gland tumors displaying similar histopathologic features as the salivary gland tumors. In conclusion, our results establish the strong and apparently direct in vivo tumorigenic capacity of PLAG1 and indicate that the transgenic mice constitute a valuable model for pleomorphic salivary gland tumorigenesis and potentially for other glands as well.

  10. Ultrasensitive quantitation of human papillomavirus type 16 E6 oncogene sequences by nested real time PCR

    Directory of Open Access Journals (Sweden)

    López-Revilla Rubén

    2010-05-01

    Full Text Available Abstract Background We have developed an ultrasensitive method based on conventional PCR preamplification followed by nested amplification through real time PCR (qPCR in the presence of the DNA intercalating agent EvaGreen. Results Amplification mixtures calibrated with a known number of pHV101 copies carrying a 645 base pair (bp-long insert of the human papillomavirus type 16 (HPV16 E6 oncogene were used to generate the E6-1 amplicon of 645 bp by conventional PCR and then the E6-2 amplicon of 237 bp by nested qPCR. Direct and nested qPCR mixtures for E6-2 amplification corresponding to 2.5 × 102-2.5 × 106 initial pHV101 copies had threshold cycle (Ct values in the ranges of 18.7-29.0 and 10.0-25.0, respectively. The Ct of qPCR mixtures prepared with 1/50 volumes of preamplified mixtures containing 50 ng of DNA of the SiHa cell line (derived from an invasive cervical cancer with one HPV16 genome per cell was 19.9. Thermal fluorescence extinction profiles of E6-2 amplicons generated from pHV101 and SiHa DNA were identical, with a peak at 85.5°C. Conclusions Our method based on conventional preamplification for 15 cycles increased 10,750 times the sensitivity of nested qPCR for the quantitation of the E6 viral oncogene and confirmed that the SiHa cell line contains one E6-HPV16 copy per cell.

  11. Microarray analysis of colorectal cancer stromal tissue reveals upregulation of two oncogenic miRNA clusters.

    Science.gov (United States)

    Nishida, Naohiro; Nagahara, Makoto; Sato, Tetsuya; Mimori, Koshi; Sudo, Tomoya; Tanaka, Fumiaki; Shibata, Kohei; Ishii, Hideshi; Sugihara, Kenichi; Doki, Yuichiro; Mori, Masaki

    2012-06-01

    Cancer stroma plays an important role in the progression of cancer. Although alterations in miRNA expression have been explored in various kinds of cancers, the expression of miRNAs in cancer stroma has not been explored in detail. Using a laser microdissection technique, we collected RNA samples specific for epithelium or stroma from 13 colorectal cancer tissues and four normal tissues, and miRNA microarray and gene expression microarray were carried out. The expression status of miRNAs was confirmed by reverse transcriptase PCR. Furthermore, we investigated whether miRNA expression status in stromal tissue could influence the clinicopathologic factors. Oncogenic miRNAs, including two miRNA clusters, miR-17-92a and miR-106b-25 cluster, were upregulated in cancer stromal tissues compared with normal stroma. Gene expression profiles from cDNA microarray analyses of the same stromal tissue samples revealed that putative targets of these miRNA clusters, predicted by Target Scan, such as TGFBR2, SMAD2, and BMP family genes, were significantly downregulated in cancer stromal tissue. Downregulated putative targets were also found to be involved in cytokine interaction and cellular adhesion. Importantly, expression of miR-25 and miR-92a in stromal tissues was associated with a variety of clinicopathologic factors. Oncogenic miRNAs were highly expressed in cancer stroma. Although further validation is required, the finding that stromal miRNA expression levels were associated with clinicopathologic factors suggests the possibility that miRNAs in cancer stroma are crucially involved in cancer progression.

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

    Science.gov (United States)

    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.

  13. SCD1 Expression is dispensable for hepatocarcinogenesis induced by AKT and Ras oncogenes in mice.

    Directory of Open Access Journals (Sweden)

    Lei Li

    Full Text Available Increased de novo lipogenesis is one of the major metabolic events in cancer. In human hepatocellular carcinoma (HCC, de novo lipogenesis has been found to be increased and associated with the activation of AKT/mTOR signaling. In mice, overexpression of an activated form of AKT results in increased lipogenesis and hepatic steatosis, ultimately leading to liver tumor development. Hepatocarcinogenesis is dramatically accelerated when AKT is co-expressed with an oncogenic form of N-Ras. SCD1, the major isoform of stearoyl-CoA desaturases, catalyzing the conversion of saturated fatty acids (SFA into monounsaturated fatty acids (MUFA, is a key enzyme involved in de novo lipogenesis. While many studies demonstrated the requirement of SCD1 for tumor cell growth in vitro, whether SCD1 is necessary for tumor development in vivo has not been previously investigated. Here, we show that genetic ablation of SCD1 neither inhibits lipogenesis and hepatic steatosis in AKT-overexpressing mice nor affects liver tumor development in mice co-expressing AKT and Ras oncogenes. Molecular analysis showed that SCD2 was strongly upregulated in liver tumors from AKT/Ras injected SCD1(-/- mice. Noticeably, concomitant silencing of SCD1 and SCD2 genes was highly detrimental for the growth of AKT/Ras cells in vitro. Altogether, our study provides the evidence, for the first time, that SCD1 expression is dispensable for AKT/mTOR-dependent hepatic steatosis and AKT/Ras-induced hepatocarcinogenesis in mice. Complete inhibition of stearoyl-CoA desaturase activity may be required to efficiently suppress liver tumor development.

  14. The Mitochondrial Genome Is a “Genetic Sanctuary” during the Oncogenic Process

    Science.gov (United States)

    Gonzalez, Teresa; Fraga, Maximo; Salas, Antonio; Costoya, Jose A.

    2011-01-01

    Since Otto Warburg linked mitochondrial physiology and oncogenesis in the 1930s, a number of studies have focused on the analysis of the genetic basis for the presence of aerobic glycolysis in cancer cells. However, little or no evidence exists today to indicate that mtDNA mutations are directly responsible for the initiation of tumor onset. Based on a model of gliomagenesis in the mouse, we aimed to explore whether or not mtDNA mutations are associated with the initiation of tumor formation, maintenance and aggressiveness. We reproduced the different molecular events that lead from tumor initiation to progression in the mouse glioma. In human gliomas, most of the genetic alterations that have been previously identified result in the aberrant activation of different signaling pathways and deregulation of the cell cycle. Our data indicates that mitochondrial dysfunction is associated with reactive oxygen species (ROS) generation, leading to increased nuclear DNA (nDNA) mutagenesis, but maintaining the integrity of the mitochondrial genome. In addition, mutational stability has been observed in entire mtDNA of human gliomas; this is in full agreement with the results obtained in the cancer mouse model. We use this model as a paradigm of oncogenic transformation due to the fact that mutations commonly found in gliomas appear to be the most common molecular alterations leading to tumor development in most types of human cancer. Our results indicate that the mtDNA genome is kept by the cell as a “genetic sanctuary” during tumor development in the mouse and humans. This is compatible with the hypothesis that the mtDNA molecule plays an essential role in the control of the cellular adaptive survival response to tumor-induced oxidative stress. The integrity of mtDNA seems to be a necessary element for responding to the increased ROS production associated with the oncogenic process. PMID:21858071

  15. [Clinical relevance of the K-ras oncogene in colorectal cancer: experience in a Mexican population].

    Science.gov (United States)

    Cabrera-Mendoza, F; Gainza-Lagunes, S; Castañeda-Andrade, I; Castro-Zárate, A

    2014-01-01

    Colorectal cancer is frequent in the developed countries, with a cancer-specific mortality rate of 33%. Different biomarkers are associated with overall survival and the prediction of monoclonal treatment effectiveness. The presence of mutations in the K-ras oncogene alters the response to target therapy with cetuximab and could be an independent prognostic factor. To analyze the difference in survival between patients with mutated K-ras and those with K-ras wild-type status. Thirty-one clinical records were retrospectively analyzed of patients presenting with colorectal cancer that underwent K-ras sequencing through real-time polymerase chain reaction within the time frame of 2009 to 2012 at the Hospital de Alta Especialidad de Veracruz of the Instituto para la Salud y Seguridad Social de los Trabajadores del Estado (HAEV-ISSSTE). Survival analysis for patients with and without K-ras mutation was performed using the Kaplan Meier method. Contrast of covariates was performed using logarithmic transformations. No statistically significant difference was found in relation to survival in the patients with mutated K-ras vs. those with K-ras wild-type (P=.416), nor were significant differences found when analyzing the covariants and survival in the patients with mutated K-ras: ECOG scale (P=.221); age (less than, equal to or greater than 65years, P=.441); clinical stage according to the AJCC (P=.057), and primary lesion site (P=.614). 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. Copyright © 2013 Asociación Mexicana de Gastroenterología. Published by Masson Doyma México S.A. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. Spectrum of oncogenic driver mutations in lung adenocarcinomas from East Asian never smokers.

    Directory of Open Access Journals (Sweden)

    Chenguang Li

    Full Text Available PURPOSE: We previously showed that 90% (47 of 52; 95% CI, 0.79 to 0.96 of lung adenocarcinomas from East Asian never-smokers harbored well-known oncogenic mutations in just four genes: EGFR, HER2, ALK, and KRAS. Here, we sought to extend these findings to more samples and identify driver alterations in tumors negative for these mutations. EXPERIMENTAL DESIGN: We have collected and analyzed 202 resected lung adenocarcinomas from never smokers seen at Fudan University Shanghai Cancer Center. Since mutations were mutually exclusive in the first 52 examined, we determined the status of EGFR, KRAS, HER2, ALK, and BRAF in stepwise fashion as previously described. Samples negative for mutations in these 5 genes were subsequently examined for known ROS1 fusions by RT-PCR and direct sequencing. RESULTS: 152 tumors (75.3% harbored EGFR mutations, 12 (6% had HER2 mutations, 10 (5% had ALK fusions all involving EML4 as the 5' partner, 4 (2% had KRAS mutations, and 2 (1% harbored ROS1 fusions. No BRAF mutation were detected. CONCLUSION: The vast majority (176 of 202; 87.1%, 95% CI: 0.82 to 0.91 of lung adenocarcinomas from never smokers harbor mutant kinases sensitive to available TKIs. Interestingly, patients with EGFR mutant patients tend to be older than those without EGFR mutations (58.3 Vs 54.3, P = 0.016 and patient without any known oncogenic driver tend to be diagnosed at a younger age (52.3 Vs 57.9, P = 0.013. Collectively, these data indicate that the majority of never smokers with lung adenocarcinoma could benefit from treatment with a specific tyrosine kinase inhibitor.

  19. Characterization of new cell line stably expressing CHI3L1 oncogene

    Directory of Open Access Journals (Sweden)

    Chekhonin V. P.

    2011-06-01

    Full Text Available Aim. To characterize the immortalized 293 cell line after stable transfection with human oncogene (CHI3L1. Methods. 293 cells, stably transfected with pcDNA3.1_CHI3L1, and 293 cells, stably transfected with pcDNA3.1 as a negative control, were used throughout all experiments. The clones of CHI3L1-expressing 293 cells and 293 cells, transfected with pcDNA3.1, were analyzed by immunofluorescence and confocal microscopy. Cell proliferation was measured using MTT assay; analyses of ERK1/2 and AKT activation and their cellular localization were performed with anti-phospho-ERK and anti-phospho-AKT antibodies. Specific activation of MAP and PI3 kinases was measured by densitometric analysis of Western-blot signals. Results. The obtained results show quite modest ability of CHI3L1 to stimulate cell growth and reflect rather an improved cellular plating efficiency of the 293 cells stably transfected with pcDNA3.1_CHI3L1 as compared to the 293 cells transfected with an «empty» vector. ERK1/2 and AKT are activated in the 293_CHI3L1 cells. In these cells phosphorylated ERK1/2 were localized in both cell cytoplasm and nuclei while AKT only in cytoplasm. The 293_CHI3L1 cells differed from the 293 cells, transfected with an «empty» vector, in their size and ability to adhere to the culture plates. Conclusions. The overexpression of CHI3L1 is likely to have an important role in tumorigenesis via a mechanism which involves activation of PI3K and ERK1/2 pathways. The tumors which can be induced by orthotopic implantation of the transformed human cells with overexpressed human oncogene CHI3L1 into the rat brain can be used as a target for anticancer drug development.

  20. Kita driven expression of oncogenic HRAS leads to early onset and highly penetrant melanoma in zebrafish.

    Directory of Open Access Journals (Sweden)

    Cristina Santoriello

    Full Text Available BACKGROUND: Melanoma is the most aggressive and lethal form of skin cancer. Because of the increasing incidence and high lethality of melanoma, animal models for continuously observing melanoma formation and progression as well as for testing pharmacological agents are needed. METHODOLOGY AND PRINCIPAL FINDINGS: Using the combinatorial Gal4-UAS system, we have developed a zebrafish transgenic line that expresses oncogenic HRAS under the kita promoter. Already at 3 days transgenic kita-GFP-RAS larvae show a hyper-pigmentation phenotype as earliest evidence of abnormal melanocyte growth. By 2-4 weeks, masses of transformed melanocytes form in the tail stalk of the majority of kita-GFP-RAS transgenic fish. The adult tumors evident between 1-3 months of age faithfully reproduce the immunological, histological and molecular phenotypes of human melanoma, but on a condensed time-line. Furthermore, they show transplantability, dependence on mitfa expression and do not require additional mutations in tumor suppressors. In contrast to kita expressing melanocyte progenitors that efficiently develop melanoma, mitfa expressing progenitors in a second Gal4-driver line were 4 times less efficient in developing melanoma during the three months observation period. CONCLUSIONS AND SIGNIFICANCE: This indicates that zebrafish kita promoter is a powerful tool for driving oncogene expression in the right cells and at the right level to induce early onset melanoma in the presence of tumor suppressors. Thus our zebrafish model provides a link between kita expressing melanocyte progenitors and melanoma and offers the advantage of a larval phenotype suitable for large scale drug and genetic modifier screens.

  1. 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.

  2. ESPL1 is a candidate oncogene of luminal B breast cancers.

    Science.gov (United States)

    Finetti, Pascal; Guille, Arnaud; Adelaide, José; Birnbaum, Daniel; Chaffanet, Max; Bertucci, François

    2014-08-01

    ESPL1/separase is a putative oncogene of luminal B breast cancers. Histoclinical correlations of its expression have never been explored in large series of breast tumors, and specifically in the luminal subtype. In a pooled series of invasive breast carcinomas profiled using DNA microarrays, we identified 3,074 luminal cases, including 1,307 luminal B tumors, in which we searched for correlations between ESPL1 mRNA expression and molecular and histoclinical features. Compared to normal breast samples, ESPL1 was overexpressed in 52 % of luminal tumors, and much more frequently in luminal B (83 %) than luminal A tumors (29 %). In luminal breast cancers, higher ESPL1 expression was associated with poor-prognosis criteria (age ≤ 50 years, ductal type, advanced stage, large tumor size, lymph node-positive status, high grade, PR-negative status, luminal B subtype) and with poor metastasis-free survival in both uni- and multivariate analyses. This independent prognostic value was also observed in luminal B tumors only, and persisted when compared with gene expression signatures (PAM50, Recurrence Score, Mammaprint, EndoPredict) currently proposed to refine the indications of adjuvant chemotherapy in hormone receptor-positive/HER2-negative breast cancer. We also confirmed the observations made with experimental mouse models: ESPL1-overexpressing luminal tumors showed complex genomic profiles and molecular features of chromosomal instability and loss of tumor suppressor genes (P53 and Rb). Our results reinforce the idea that ESPL1 is a candidate oncogene in luminal B cancers. Its expression may help improve the prognostication. Inhibiting ESPL1 may represent a promising therapeutic approach for these poor-prognosis tumors.

  3. 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.

  4. Detection of FLT3 Oncogene Mutations in Acute Myeloid Leukemia Using Conformation Sensitive Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Mamdooh Gari

    2008-11-01

    Full Text Available FLT3 (fms-related tyrosine kinase 3 is a receptor tyrosine kinase class III that is expressed on by early hematopoietic progenitor cells and plays an important role in hematopoietic stem cell proliferation, differentiation and survival. FLT3 is also expressed on leukemia blasts in most cases of acute myeloid leukemia (AML. In order to determine the frequency of FLT3 oncogene mutations, we analyzed genomic DNA of adult de novo acute myeloid leukemia (AML. Polymerase chain reaction (PCR and conformation-sensitive gel electrophoresis (CSGE were used for FLT3 exons 11, 14, and 15, followed by direct DNA sequencing. Two different types of functionally important FLT 3 mutations have been identified. Those mutations were unique to patients with inv(16, t(15:17 or t(8;21 and comprised fifteen cases with internal tandem duplication (ITD mutation in the juxtamembrane domain and eleven cases with point mutation (exon 20, Asp835Tyr. The high frequency of the flt3 proto-oncogene mutations in acute myeloid leukemia AML suggests a key role for the receptor function. The association of FLT3 mutations with chromosomal abnormalities invites speculation as to the link between these two changes in the pathogenesis of acute myeloid leukemiaAML. Furthermore, CSGE method has shown to be a rapid and sensitive screening method for detection of nucleotide alteration in FLT3 gene. Finally, this study reports, for the first time in Saudi Arabia, mutations in the human FLT3 gene in acute myeloid leukemia AML patients.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Oncogenic role and therapeutic target of leptin signaling in breast cancer and cancer stem cells

    Science.gov (United States)

    Guo, Shanchun; Liu, Mingli; Wang, Guangdi; Torroella-Kouri, Marta; Gonzalez-Perez, Ruben R.

    2012-01-01

    Significant correlations between obesity and incidence of various cancers have been reported. Obesity, considered a mild inflammatory process, is characterized by a high level of secretion of several cytokines from adipose tissue. These molecules have disparate effects, which could be relevant to cancer development. Among the inflammatory molecules, leptin, mainly produced by adipose tissue and overexpressed with its receptor (Ob-R) in cancer cells is the most studied adipokine. Mutations of leptin or Ob-R genes associated with obesity or cancer are rarely found. However, leptin is an anti-apoptotic molecule in many cell types, and its central roles in obesity-related cancers are based on its pro-angiogenic, pro-inflammatory and mitogenic actions. Notably, these leptin actions are commonly reinforced through entangled crosstalk with multiple oncogenes, cytokines and growth factors. Leptin-induced signals comprise several pathways commonly triggered by many cytokines (i.e, canonical: JAK2/STAT; MAPK/ERK1/2 and PI-3K/AKT1 and, non-canonical signaling pathways: PKC, JNK and p38 MAP kinase). Each of these leptin-induced signals is essential to its biological effects on food intake, energy balance, adiposity, immune and endocrine systems, as well as oncogenesis. This review is mainly focused on the current knowledge of the oncogenic role of leptin in breast cancer. Additionally, leptin pro-angiogenic molecular mechanisms and its potential role in breast cancer stem cells will be reviewed. Strict biunivocal binding-affinity and activation of leptin/Ob-R complex makes it a unique molecular target for prevention and treatment of breast cancer, particularly in obesity contexts. PMID:22289780

  8. The mitochondrial genome is a "genetic sanctuary" during the oncogenic process.

    Directory of Open Access Journals (Sweden)

    Marcos Seoane

    Full Text Available Since Otto Warburg linked mitochondrial physiology and oncogenesis in the 1930s, a number of studies have focused on the analysis of the genetic basis for the presence of aerobic glycolysis in cancer cells. However, little or no evidence exists today to indicate that mtDNA mutations are directly responsible for the initiation of tumor onset. Based on a model of gliomagenesis in the mouse, we aimed to explore whether or not mtDNA mutations are associated with the initiation of tumor formation, maintenance and aggressiveness. We reproduced the different molecular events that lead from tumor initiation to progression in the mouse glioma. In human gliomas, most of the genetic alterations that have been previously identified result in the aberrant activation of different signaling pathways and deregulation of the cell cycle. Our data indicates that mitochondrial dysfunction is associated with reactive oxygen species (ROS generation, leading to increased nuclear DNA (nDNA mutagenesis, but maintaining the integrity of the mitochondrial genome. In addition, mutational stability has been observed in entire mtDNA of human gliomas; this is in full agreement with the results obtained in the cancer mouse model. We use this model as a paradigm of oncogenic transformation due to the fact that mutations commonly found in gliomas appear to be the most common molecular alterations leading to tumor development in most types of human cancer. Our results indicate that the mtDNA genome is kept by the cell as a "genetic sanctuary" during tumor development in the mouse and humans. This is compatible with the hypothesis that the mtDNA molecule plays an essential role in the control of the cellular adaptive survival response to tumor-induced oxidative stress. The integrity of mtDNA seems to be a necessary element for responding to the increased ROS production associated with the oncogenic process.

  9. BRAF inhibitor resistance mediated by the AKT pathway in an oncogenic BRAF mouse melanoma model.

    Science.gov (United States)

    Perna, Daniele; Karreth, Florian A; Rust, Alistair G; Perez-Mancera, Pedro A; Rashid, Mamunur; Iorio, Francesco; Alifrangis, Constantine; Arends, Mark J; Bosenberg, Marcus W; Bollag, Gideon; Tuveson, David A; Adams, David J

    2015-02-10

    BRAF (v-raf murine sarcoma viral oncogene homolog B) inhibitors elicit a transient anti-tumor response in ∼ 80% of BRAF(V600)-mutant melanoma patients that almost uniformly precedes the emergence of resistance. Here we used a mouse model of melanoma in which melanocyte-specific expression of Braf(V618E) (analogous to the human BRAF(V600E) mutation) led to the development of skin hyperpigmentation and nevi, as well as melanoma formation with incomplete penetrance. Sleeping Beauty insertional mutagenesis in this model led to accelerated and fully penetrant melanomagenesis and synchronous tumor formation. Treatment of Braf(V618E) transposon mice with the BRAF inhibitor PLX4720 resulted in tumor regression followed by relapse. Analysis of transposon insertions identified eight genes including Braf, Mitf, and ERas (ES-cell expressed Ras) as candidate resistance genes. Expression of ERAS in human melanoma cell lines conferred resistance to PLX4720 and induced hyperphosphorylation of AKT (v-akt murine thymoma viral oncogene homolog 1), a phenotype reverted by combinatorial treatment with PLX4720 and the AKT inhibitor MK2206. We show that ERAS expression elicits a prosurvival signal associated with phosphorylation/inactivation of BAD, and that the resistance of hepatocyte growth factor-treated human melanoma cells to PLX4720 can be reverted by treatment with the BAD-like BH3 mimetic ABT-737. Thus, we define a role for the AKT/BAD pathway in resistance to BRAF inhibition and illustrate an in vivo approach for finding drug resistance genes.

  10. Transmission between Archaic and Modern Human Ancestors during the Evolution of the Oncogenic Human Papillomavirus 16.

    Science.gov (United States)

    Pimenoff, Ville N; de Oliveira, Cristina Mendes; Bravo, Ignacio G

    2017-01-01

    Every human suffers through life a number of papillomaviruses (PVs) infections, most of them asymptomatic. A notable exception are persistent infections by Human papillomavirus 16 (HPV16), the most oncogenic infectious agent for humans and responsible for most infection-driven anogenital cancers. Oncogenic potential is not homogeneous among HPV16 lineages, and genetic variation within HPV16 exhibits some geographic structure. However, an in-depth analysis of the HPV16 evolutionary history was still wanting. We have analyzed extant HPV16 diversity and compared the evolutionary and phylogeographical patterns of humans and of HPV16. We show that codivergence with modern humans explains at most 30% of the present viral geographical distribution. The most explanatory scenario suggests that ancestral HPV16 already infected ancestral human populations and that viral lineages co-diverged with the hosts in parallel with the split between archaic Neanderthal-Denisovans and ancestral modern human populations, generating the ancestral HPV16A and HPV16BCD viral lineages, respectively. We propose that after out-of-Africa migration of modern human ancestors, sexual transmission between human populations introduced HPV16A into modern human ancestor populations. We hypothesize that differential coevolution of HPV16 lineages with different but closely related ancestral human populations and subsequent host-switch events in parallel with introgression of archaic alleles into the genomes of modern human ancestors may be largely responsible for the present-day differential prevalence and association with cancers for HPV16 variants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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

    Science.gov (United States)

    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.

  12. 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

  13. 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.

  14. Immunolocalization of glioma-associated oncogene homolog 1 in non melanoma skin cancer.

    Science.gov (United States)

    Bakry, Ola Ahmed; Samaka, Rehab Monir; Shoeib, Mohamed Abdel Moneim; Megahed, Doaa Mohamed

    2015-04-01

    Glioma-associated oncogene homolog (GLI)1 is involved in controlling cell proliferation and angiogenesis. The aim of this work was to explore its possible role in non-melanoma skin cancer pathogenesis through its immunohistochemical (IHC) expression in skin biopsies of these diseases and correlating this expression with the clinico-pathological parameters of the studied cases. Seventy-six cutaneous specimens were studied; 30 cases with basal cell carcinoma (BCC), 30 cases with squamous cell carcinoma (SCC) and 16 normal skin samples, from age- and gender-matched subjects, as a control group. GLI1 was expressed in all BCC cases and in 60% of SCC cases. All SCC cases showed cytoplasmic, while 70% of BCC cases showed nucleocytoplasmic immunoreactivity. It was over expressed in BCC and SCC compared to normal skin (p = 0.01 and 0.0006, respectively). Higher Histo (H) score in BCC cases was significantly associated with female gender (p = 0.04), multiple lesions, desmoplastic stromal reaction and stromal angiogenesis (p < 0.001 for all). Higher H score in SCC cases was significantly associated with scalp location, nodular type, recurrent lesions, high tumor grade, lymphovascular invasion (p = 0.004 for all), inflammatory stromal reaction (p = 0.01), lymph node involvement and absence of calcification (p = 0.001 for both). In conclusion, GLI1 may play a role in BCC pathogenesis through its role in cell proliferation, migration, and angiogenesis. Its upregulation and cytoplasmic localization in SCC may suggest that its role in tumor pathogenesis is through mechanisms other than Hedgehog pathway activation. Further studies are needed to clarify the exact molecular basis of its oncogenic action.

  15. Crosstalk from non-cancerous mitochondria can inhibit tumor properties of metastatic cells by suppressing oncogenic pathways.

    Science.gov (United States)

    Kaipparettu, Benny Abraham; Ma, Yewei; Park, Jun Hyoung; Lee, Tin-Lap; Zhang, Yiqun; Yotnda, Patricia; Creighton, Chad J; Chan, Wai-Yee; Wong, Lee-Jun C

    2013-01-01

    Mitochondrial-nucleus cross talks and mitochondrial retrograde regulation can play a significant role in cellular properties. Transmitochondrial cybrid systems (cybrids) are an excellent tool to study specific effects of altered mitochondria under a defined nuclear background. The majority of the studies using the cybrid model focused on the significance of specific mitochondrial DNA variations in mitochondrial function or tumor properties. However, most of these variants are benign polymorphisms without known functional significance. From an objective of rectifying mitochondrial defects in cancer cells and to establish mitochondria as a potential anticancer drug target, understanding the role of functional mitochondria in reversing oncogenic properties under a cancer nuclear background is very important. Here we analyzed the potential reversal of oncogenic properties of a highly metastatic cell line with the introduction of non-cancerous mitochondria. Cybrids were established by fusing the mitochondria DNA depleted 143B TK- ρ0 cells from an aggressive osteosarcoma cell line with mitochondria from benign breast epithelial cell line MCF10A, moderately metastatic breast cancer cell line MDA-MB-468 and 143B cells. In spite of the uniform cancerous nuclear background, as observed with the mitochondria donor cells, cybrids with benign mitochondria showed high mitochondrial functional properties including increased ATP synthesis, oxygen consumption and respiratory chain activities compared to cybrids with cancerous mitochondria. Interestingly, benign mitochondria could reverse different oncogenic characteristics of 143B TK(-) cell including cell proliferation, viability under hypoxic condition, anti-apoptotic properties, resistance to anti-cancer drug, invasion, and colony formation in soft agar, and in vivo tumor growth in nude mice. Microarray analysis suggested that several oncogenic pathways observed in cybrids with cancer mitochondria are inhibited in cybrids with

  16. 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.

  17. G.I.S. Surveillance of Chronic Non-occupational Exposure to Heavy Metals as Oncogenic Risk

    Directory of Open Access Journals (Sweden)

    Mariana Vlad

    2016-02-01

    Full Text Available Introduction: The potential oncogenic effect of some heavy metals in people occupationally and non-occupationally exposed to such heavy metals is already well demonstrated. This study seeks to clarify the potential role of these heavy metals in the living environment, in this case in non-occupational multifactorial aetiology of malignancies in the inhabitants of areas with increased prevalent environmental levels of heavy metals. Methods: Using a multidisciplinary approach throughout a complex epidemiological study, we investigated the potential oncogenic role of non-occupational environmental exposure to some heavy metals [chrome (Cr, nickel (Ni, copper (Cu, zinc (Zn, cadmium (Cd, lead (Pb and arsenic (As—in soil, drinking water, and food, as significant components of the environment] in populations living in areas with different environmental levels (high vs. low of the above-mentioned heavy metals. The exposures were evaluated by identifying the exposed populations, the critical elements of the ecosystems, and as according to the means of identifying the types of exposure. The results were interpreted both epidemiologically (causal inference, statistical significance, mathematical modelling and by using a GIS approach, which enabled indirect surveillance of oncogenic risks in each population. Results: The exposure to the investigated heavy metals provides significant risk factors of cancer in exposed populations, in both urban and rural areas [χ² test (p < 0.05]. The GIS approach enables indirect surveillance of oncogenic risk in populations. Conclusions: The role of non-occupational environmental exposure to some heavy metals in daily life is among the more significant oncogenic risk factors in exposed populations. The statistically significant associations between environmental exposure to such heavy metals and frequency of neoplasia in exposed populations become obvious when demonstrated on maps using the GIS system. Environmental

  18. Investigation of oncogenic cooperation in simple liver-specific transgenic mouse models using noninvasive in vivo imaging.

    Directory of Open Access Journals (Sweden)

    Hye-Lim Ju

    Full Text Available Liver cancer is a complex multistep process requiring genetic alterations in multiple proto-oncogenes and tumor suppressor genes. Although hundreds of genes are known to play roles in hepatocarcinogenesis, oncogenic collaboration among these genes is still largely unknown. Here, we report a simple methodology by which oncogenic cooperation between cancer-related genes can be efficiently investigated in the liver. We developed various non-germline transgenic mouse models using hydrodynamics-based transfection which express HrasG12V, SmoM2, and a short-hairpin RNA down-regulating p53 (shp53 individually or in combination in the liver. In this transgenic system, firefly luciferase was co-expressed with the oncogenes as a reporter, allowing tumor growth in the liver to be monitored over time without an invasive procedure. Very strong bioluminescence imaging (BLI signals were observed at 4 weeks post-hydrodynamic injection (PHI in mice co-expressing HrasG12V and shp53, while only background signals were detected in other double or single transgenic groups until 30 weeks PHI. Consistent with the BLI data, tumors were observed in the HrasG12V plus shp53 group at 4 weeks PHI, while other transgenic groups failed to exhibit a hyperplastic nodule at 30 weeks PHI. In the HrasG12V plus shp53 transgenic group, BLI signals were well-correlated with actual tumor growth in the liver, confirming the versatility of BLI-based monitoring of tumor growth in this organ. The methodology described here is expected to accelerate and facilitate in vivo studies of the hepatocarcinogenic potential of cancer-related genes by means of oncogenic cooperation.

  19. 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.

  20. 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

  1. RNA extraction method is crucial for human papillomavirus E6/E7 oncogenes detection.

    Science.gov (United States)

    Fontecha, Nerea; Nieto, Maria Carmen; Andía, Daniel; Cisterna, Ramón; Basaras, Miren

    2017-03-09

    Human papillomavirus (HPV) DNA testing plays a main role in the management of cervical cancer, however to improve the specificity in cervical screening, there is a need to develop and validate different approaches that can identify women at risk for progressive disease. Nowadays, mRNA expression of viral E6 and E7 HPV oncogenes stands up as a potential biomarker to improve cervical screening. We aimed to validate a method for RNA extraction, detect HPV mRNA expression and, assess the relationship between E6/E7 mRNA expression and pathology of patients' lesions and progression. This study included 50 specimens that had been previously genotyped as HPV16, 18, 31, 33 and/or 45. Cervical swabs were extracted with three different RNA extraction methods -Nuclisens manual extraction kit (bioMérieux), High Pure Viral RNA Kit (Roche) and RNeasy Plus Mini kit (Qiagen)-, and mRNA was detected with NucliSens EasyQ HPV version 1 test (bioMérieux) afterwards. Association of oncogene expression with pathology and lesion progression was analyzed for each extraction method. E6/E7 mRNA positivity rate was higher in samples analyzed with bioMérieux (62%), followed by Roche (24%) and Qiagen (6%). Women with lesions and lesion progression showed a higher prevalence of viral RNA expression than women that had not lesions or with lesion persistence. While bioMérieux revealed a higher sensitivity (77.27%), Roche presented a higher PPV (75%) and an increased specificity (89.28%). Extraction methods based on magnetic beads provided better RNA yield than those based in columns. Both Nuclisens manual extraction kit (bioMérieux) and High Pure Viral RNA Kit (Roche) seemed to be adequate for E6/E7 mRNA detection. However, none of them revealed both high sensitivity and specificity values. Further studies are needed to obtain and validate a standard gold method for RNA expression detection, to be included as part of the routine cervical screening program.

  2. The functional and structural characterization of a novel oncogene GIG47 involved in the breast tumorigenesis

    Directory of Open Access Journals (Sweden)

    Han Kyou-Hoon

    2012-07-01

    Full Text Available Abstract Background A candidate oncogene GIG47, previously known as a neudesin with a neurotrophic activity, was identified by applying the differential expression analysis method. Methods As a first step to understand the molecular role of GIG47, we analyzed the expression profile of GIG47 in multiple human cancers including the breast cancer and characterized its function related to human carcinogenesis. Based on this oncogenic role of GIG47, we then embarked on determining the high-resolution structure of GIG47. We have applied multidimensional heteronuclear NMR methods to GIG47. Results GIG47 was over-expressed in primary breast tumors as well as other human tumors including carcinomas of the uterine cervix, malignant lymphoma, colon, lung, skin, and leukemia. To establish its role in the pathogenesis of breast cancer in humans, we generated stable transfectants of MCF7 cells. The ectopic expression of GIG47 in MCF7 cells promoted the invasiveness in the presence of 50% serum. In addition, it also resulted in the increased tumorigenicity in in vivo tumor formation assay. The tumorigenesis mechanism involving GIG47 might be mediated by the activation of MAPK and PI3K pathways. These results indicate that GIG47 plays a role in the breast tumorigenesis, thus representing a novel target for the treatment of breast cancer. To facilitate the development of GIG47-targeted therapeutics, we determined the structural configuration of GIG47. The high-resolution structure of GIG47 was obtained by combination of NMR and homology modeling. The overall structure of GIG47 has four α-helices and 6 β-strands, arranged in a β1-α1-β2-β3-α2-β4-α3-α4-β5-β6 topology. There is a potential heme/steroid binding pocket formed between two helices α2 and α3. Conclusion The determined three-dimensional structure of GIG47 may facilitate the development of potential anti-cancer agents.

  3. Seven Novel and Stable Translocations Associated with Oncogenic Gene Expression in Malignant Melanoma

    Directory of Open Access Journals (Sweden)

    Ichiro Okamoto

    2005-04-01

    Full Text Available Cytogenetics has not only precipitated the discovery of several oncogenes, but has also led to the molecular classification of numerous malignancies. The correct identification of aberrations in many tumors has, however, been hindered by extensive tumor complexity and the limitations of molecular cytogenetic techniques. In this study, we have investigated five malignant melanoma (MM cell lines from at least three different passages using high-resolution R-banding and the recently developed methods of comparative genomic hybridization and multicolor or multiplex fluorescence in situ hybridization. We subsequently detected nine consistent translocations, seven of which were novel: dic(1;11(p10;q14, der(9t(3;9(p12;p11, der(4t(9;4;7(q33::p15-q23::q21, der(14t(5;14 (q12;q32, der(9t(9;22(p21;q11, der(19t(19;20(p13.3;p11, der(10t(2;12;7;10(q31::p12→pter::q11.2→q31::q21,der(19t(10;19(q23;q13, and der(20t(Y;20(q11.23;q13.3. Furthermore, using the human HG-U133A Gene-Chip, positive expression levels of oncogenes or tumor-related genes located at the regions of chromosomal breakpoints were identified, including AKT1, BMI1, CDK6, CTNNB1, E2F1, GPNMB, GPRK7, KBRAS2, LDB2, LIMK1, MAPK1, MEL, MP1, MUC18, NRCAM, PBX3, RAB22A, RAB38, SNK, and STK4, indicating an association between chromosomal breakpoints and altered gene expression. Moreover, we also show that growth of all five cell lines can be significantly reduced by downregulating CDK6 gene expression with small interfering RNA (siRNA. Because the majority of these breakpoints have been reported previously in MM, our results support the idea of commonmechanisms in this disease.

  4. Oncogene Regulation during the Growth and Differentiation of a Human Promyelocytic Leukemia Cell Line.

    Science.gov (United States)

    Ely, Constance Marie

    To determine the significance of the regulation of the cellular oncogenes c-myc and c-myb during myeloid and monocytic differentiation, we analyzed oncogene expression concurrent with functional and morphological differences in HL-60 cells and in a partial differentiation resistant HL-60 clone (HL-60-1E3). Although HL-60-1E3 cells are unable to develop mature terminally differentiated features with PDBu or DMSO stimulation, they do exhibit partial differentiation features with these conditions. Treatments of HL-60-1E3 cells with PDBu preceded by treatment with dimethylsulfoxide (DMSO), results in complete maturation to macrophage-like cells. Using parallel PDBu-induction studies, we analyzed the kinetics of expression of c-myc, c-myb, c-fms, c-fos, c-raf, and histone H4, together with cell cycle frequency distribution, cytotoxic effector activity and clonogenic potential in HL-60 and HL-60-1E3 cells. The results of these studies revealed altered c-myc and c-myb regulation in resistant cells corresponding to a lack of terminal commitment as assessed by an increase in clonogenic potential and the inability to acquire cytotoxic function. These data suggest that maintenance of the suppressed state of c-myc and c-myb gene expression may be an important component of the regulatory mechanisms which allow HL-60 cells to complete macrophage-like terminal differentiation. A similar series of experiments examining the DMSO-induced granulocyte pathway revealed that differentiation resistance of HL-60-1E3 cells corresponded to altered regulation of both c-myc and c-myb, strengthening the hypothesis that regulation of both of these genes is integral to HL-60 differentiation. Biphasic c-myb expression was observed in both cell populations in the presence of DMSO where maximal expression took place at approximately 72 hours post-induction and was not linked to proliferation. Introduction of SV40:c-myc recombinant plasmids into HL-60 cells resulted in altered nuclear morphology

  5. [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

  6. The transcription factor ATF3 acts as an oncogene in mouse mammary tumorigenesis

    Directory of Open Access Journals (Sweden)

    Thames Howard D

    2008-09-01

    -expressing cells of the murine mammary gland results in the development of squamous metaplastic lesions in nulliparous females, and in mammary tumors in biparous mice, suggesting that ATF3 acts as a mammary oncogene. A subset of human breast tumors expresses high levels of ATF3, suggesting that ATF3 may play an oncogenic role in human breast tumorigenesis, and therefore may be useful as either a biomarker or therapeutic target.

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

    Directory of Open Access Journals (Sweden)

    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

  8. COX-2 Elevates Oncogenic miR-526b in Breast Cancer by EP4 Activation.

    Science.gov (United States)

    Majumder, Mousumi; Landman, Erin; Liu, Ling; Hess, David; Lala, Peeyush K

    2015-06-01

    MicroRNAs (miRs) are small regulatory molecules emerging as potential biomarkers in cancer. Previously, it was shown that COX-2 expression promotes breast cancer progression via multiple mechanisms, including induction of stem-like cells (SLC), owing to activation of the prostaglandin E2 receptor EP4 (PTGER4). COX-2 overexpression also upregulated microRNA-526b (miR-526b), in association with aggressive phenotype. Here, the functional roles of miR-526b in breast cancer and the mechanistic role of EP4 signaling in miR-526b upregulation were examined. A positive correlation was noted between miR-526b and COX-2 mRNA expression in COX-2 disparate breast cancer cell lines. Stable overexpression of miR-526b in poorly metastatic MCF7 and SKBR3 cell lines resulted in increased cellular migration, invasion, EMT phenotype and enhanced tumorsphere formation in vitro, and lung colony formation in vivo in immunodeficient mice. Conversely, knockdown of miR-526b in aggressive MCF7-COX-2 and SKBR3-COX-2 cells reduced oncogenic functions and reversed the EMT phenotype, in vitro. Furthermore, it was determined that miR-526b expression is dependent on EP4 receptor activity and downstream PI3K-AKT and cyclic AMP (cAMP) signaling pathways. PI3K-AKT inhibitors blocked EP4 agonist-mediated miR-526b upregulation and tumorsphere formation in MCF7 and SKBR3 cells. NF-κB inhibitor abrogates EP agonist-stimulated miRNA expression in MCF7 and T47D cells, indicating that the NF-κB pathway is also involved in miR-526b regulation. In addition, inhibition of COX-2, EP4, PI3K, and PKA in COX-2-overexpressing cells downregulated miR-526b and its functions in vitro. Finally, miR-526b expression was significantly higher in cancerous than in noncancerous breast tissues and associated with reduced patient survival. In conclusion, miR-526b promotes breast cancer progression, SLC-phenotype through EP4-mediated signaling, and correlates with breast cancer patient survival. This study presents novel

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

    Directory of Open Access Journals (Sweden)

    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

  10. 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.

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

    DEFF Research Database (Denmark)

    Lassen, Louise Berkhoudt

    by the murine leukemia virus SL3-3 in heterozygous Sept9 knock out mice did not change the latency time compared to wild type; however, the distribution of T-cell subsets in the thymic tumors was altered. Moreover, Sept9 expression was increased in tumors compared to thymus and spleen non-tumorigenic tissues...... 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...... the murine leukemia virus Akv 1-99 in either sense or antisense direction. In addition a floxed PGK/Tn5 neomycin cassette was inserted. Expression analysis of Nras within knock in was used to study the effect of the LTR. If inserted before the endogenous promoter, the LTR in the antisense direction was found...

  12. An Oncogenic Role for Alternative NF-κB Signaling in DLBCL Revealed upon Deregulated BCL6 Expression

    Directory of Open Access Journals (Sweden)

    Baochun Zhang

    2015-05-01

    Full Text Available Diffuse large B cell lymphoma (DLBCL is a complex disease comprising diverse subtypes and genetic profiles. Possibly because of the prevalence of genetic alterations activating canonical NF-κB activity, a role for oncogenic lesions that activate the alternative NF-κB pathway in DLBCL has remained elusive. Here, we show that deletion/mutation of TRAF3, a negative regulator of the alternative NF-κB pathway, occurs in ∼15% of DLBCLs and that it often coexists with BCL6 translocation, which prevents terminal B cell differentiation. Accordingly, in a mouse model constitutive activation of the alternative NF-κB pathway cooperates with BCL6 deregulation in DLBCL development. This work demonstrates a key oncogenic role for the alternative NF-κB pathway in DLBCL development.

  13. 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...

  14. Oncogene activation in human benign tumors of the skin (keratoacanthomas): Is HRAS involved in differentiation as well as proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Corominas, M.; Kamino, Hideko; Leon, J.; Pellicer, A. (New York Univ. Medical Center, New York, NY (USA))

    1989-08-01

    In vitro DNA amplification followed by oligonucleotide mismatch hybridization was used to study the frequency of HRAS mutations in the benign self-regressing skin tumors keratoacanthomas and in squamous cell carcinomas. The authors used freshly obtained keratoacanthomas as well as Formalin-fixed paraffin-embedded tissues from both types of tumors. DNA from 50 samples of each tumor type was analyzed for activating mutations involving codons 12 and 61. A relatively high percentage (30%) of HRAS mutations was found in the keratoacanthomas compared with 13% in the squamous cell carcinomas. The most frequent mutation identified is the A{center dot}T-to-T{center dot}A transversion in the second position of codon 61. The present findings demonstrate the involvement of the HRAS oncogene in human benign tumors. Moreover, they indicate that an activated HRAS oncogene is not sufficient to maintain a neoplastic phenotype and argue against a role of HRAS in the progression of skin tumorigenesis.

  15. Exosomes enriched in stemness/metastatic-related mRNAS promote oncogenic potential in breast cancer

    Science.gov (United States)

    Rodríguez, Marta; Silva, Javier; Herrera, Alberto; Herrera, Mercedes; Peña, Cristina; Martín, Paloma; Gil-Calderón, Beatriz; Larriba, María Jesús; Coronado, Mª José; Soldevilla, Beatriz; Turrión, Víctor S.; Provencio, Mariano; Sánchez, Antonio; Bonilla, Félix; García-Barberán, Vanesa

    2015-01-01

    Cancer cells efficiently transfer exosome contents (essentially mRNAs and microRNAs) to other cell types, modifying immune responses, cell growth, angiogenesis and metastasis. Here we analyzed the exosomes release by breast tumor cells with different capacities of stemness/metastasis based on CXCR4 expression, and evaluated their capacity to generate oncogenic features in recipient cells. Breast cancer cells overexpressing CXCR4 showed an increase in stemness-related markers, and in proliferation, migration and invasion capacities. Furthermore, recipient cells treated with exosomes from CXCR4-cells showed increased in the same abilities. Moreover, inoculation of CXCR4-cell-derived exosomes in immunocompromised mice stimulated primary tumor growth and metastatic potential. Comparison of nucleic acids contained into exosomes isolated from patients revealed a “stemness and metastatic” signature in exosomes of patients with worse prognosis. Finally, our data supported the view that cancer cells with stem-like properties show concomitant metastatic behavior, and their exosomes stimulate tumor progression and metastasis. Exosomes-derived nucleic acids from plasma of breast cancer patients are suitable markers in the prognosis of such patients. PMID:26528758

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. High miR-196a levels promote the oncogenic phenotype of colorectal cancer cells

    Institute of Scientific and Technical Information of China (English)

    Carl Christoph Schimanski; Kirsten Frerichs; Fareed Rahman; Martin Berger; Hauke Lang; Peter R Galle; Markus Moehler; Ines Gockel

    2009-01-01

    AIM: To analyze the relevance of the microRNA miR- 196a for colorectal oncogenesis. METHODS: The impact of miR-196a on the restriction targets HoxA7, HoxB8, HoxC8 and HoxD8 was analyzed by reverse transcription polymerase chain reaction (RT-PCR) after transient transfection of SW480 cancer cells. The miR-196a transcription profile in colorectal cancer samples, mucosa samples and diverse cancer cell lines was quantified by RT-PCR. Transiently miR- 196a-transfected colorectal cancer cells were used for diverse functional assays in vitro and for a xenograft lung metastasis model in vivo. RESULTS: HoxA7, HoxB8, HoxC8 and HoxD8 were restricted by miR-196a in a dose-dependent and gene-specific manner. High levels of miR-196a activated the AKT signaling pathway as indicated by increased phosphorylation of AKT. In addition, high levels of miR-196a promoted cancer cell detachment, migration, invasion and chemosensitivity towards platin derivatives but did not impact on proliferation or apoptosis. Furthermore, miR-196a increased the development of lung metastases in mice after tail vein injection. CONCLUSION: miR-196a exerts a pro-oncogenic influence in colorectal cancer.

  19. RNA G-quadruplexes cause eIF4A-dependent oncogene translation in cancer

    Science.gov (United States)

    Wolfe, Andrew L.; Singh, Kamini; Zhong, Yi; Drewe, Philipp; Rajasekhar, Vinagolu K.; Sanghvi, Viraj R.; Mavrakis, Konstantinos J.; Jiang, Man; Roderick, Justine E.; van der Meulen, Joni; Schatz, Jonathan H.; Rodrigo, Christina M.; Zhao, Chunying; Rondou, Pieter; de Stanchina, Elisa; Teruya-Feldstein, Julie; Kelliher, Michelle A.; Speleman, Frank; Porco, John A.; Pelletier, Jerry; Rätsch, Gunnar; Wendel, Hans-Guido

    2014-09-01

    The translational control of oncoprotein expression is implicated in many cancers. Here we report an eIF4A RNA helicase-dependent mechanism of translational control that contributes to oncogenesis and underlies the anticancer effects of silvestrol and related compounds. For example, eIF4A promotes T-cell acute lymphoblastic leukaemia development in vivo and is required for leukaemia maintenance. Accordingly, inhibition of eIF4A with silvestrol has powerful therapeutic effects against murine and human leukaemic cells in vitro and in vivo. We use transcriptome-scale ribosome footprinting to identify the hallmarks of eIF4A-dependent transcripts. These include 5' untranslated region (UTR) sequences such as the 12-nucleotide guanine quartet (CGG)4 motif that can form RNA G-quadruplex structures. Notably, among the most eIF4A-dependent and silvestrol-sensitive transcripts are a number of oncogenes, superenhancer-associated transcription factors, and epigenetic regulators. Hence, the 5' UTRs of select cancer genes harbour a targetable requirement for the eIF4A RNA helicase.

  20. Immunohistochemical analysis of ras oncogene p21 product in human gastric carcinomas and their adjacent mucosas.

    Science.gov (United States)

    Carneiro, F; David, L; Sunkel, C; Lopes, C; Sobrinho-Simões, M

    1992-04-01

    In an attempt to clarify the relationship between ras oncogene expression and the clinico-pathological features of malignant and pre-malignant lesions of the stomach we undertook the immunohistochemical study of the expression of ras gene p21 product in a series of eighty gastric carcinomas and their respective adjacent mucosas. In two cases the mRNA of Ha-ras was also studied by in situ hybridization. The majority of gastric carcinomas as well as their adjacent non-neoplastic mucosas expressed ras gene product. There was a significant relationship between the expression of ras gene p21 product and the morphologic pattern of the tumours. An enhanced ras expression was found in several conditions regarded as precursor lesions of intestinal and/or diffuse types of gastric carcinoma (dysplasia, foveolar hyperplasia and even the neck zone of normal-appearing gastric glands, namely in the mucosa adjacent to diffuse carcinomas). Ras expression was actually more prominent in most of these conditions than in their respective adjacent carcinomas. No significant relationship was found between ras expression and invasiveness of the wall, nodal metastases and venous invasion.

  1. CT120A Acts as an Oncogene in Head and Neck Squamous Cell Carcinoma

    Science.gov (United States)

    Baltaci, Elif; Ekizoglu, Seda; Sari, Elif; Karaman, Emin; Ulutin, Turgut; Buyru, Nur

    2015-01-01

    Squamous cell carcinoma of the head and neck (HNSCC) is among the most frequent cancers worldwide. The etiology and pathogenesis of HNSCC are influenced by multiple genetic factors in addition to environmental and lifestyle-related factors. However, the mechanism underlying the HNSCC is still far from clear. The membrane associated gene CT120 was previously identified from chromosome 17p13.3 as a lung cancer-associated gene. Its function as an activator of the Erk and Akt signaling pathways in human lung cancer cell lines suggested that CT120 has an oncogenic function. However, there is no data in the literature on the role of CT120 in any other cancer type. Therefore, the aim of this study was to determine the expression rate and probable function of CT120 in HNSCC. Tumor tissues from 50 patients were analyzed by real-time quantitative RT-PCR to investigate the expression rate and by direct sequencing to differentiate the CT120A and CT120B variants. CT120 overexpression was observed in 58% of tumors compared to non-cancerous tissue samples and this up-regulation was directly associated with the upregulation of the CT120A variant and with the stage of the disease (p=0.001). Our results indicate that the CT120 gene may function in the development of HNSCC. PMID:26535067

  2. Oncogenic events triggered by AID, the adverse effect of antibody diversification.

    Science.gov (United States)

    Pérez-Durán, Pablo; de Yebenes, Virginia G; Ramiro, Almudena R

    2007-12-01

    The generation of an efficient immune response depends on highly refined mechanisms of antibody diversification. Two of these mechanisms, somatic hypermutation (SHM) and class switch recombination (CSR), are initiated by activation-induced cytidine deaminase (AID) upon antigen stimulation of mature B cells. AID deaminates cytosines on the DNA of Ig genes thereby generating a lesion that can be processed into a mutation (SHM) or a DNA double-strand break followed by a recombination reaction (CSR). A number of mechanisms are probably responsible for regulating AID function, such as transcriptional regulation, subcellular localization, post-transcriptional modifications and target specificity, but the issue remains of how unwanted DNA damage is fully prevented. Most lymphocyte neoplasias are originated from mature B cells and harbour hallmark chromosome translocations of lymphomagenic potential, such as the c-myc/IgH translocations found in Burkitt lymphomas. It has been recently shown that such translocations are initiated by AID and that ataxia-telangiectasia mutated, p53 and ARF provide surveillance mechanisms to prevent these aberrations. In addition, evidence is accumulating that AID expression can be induced in B cells independently of the germinal centre environment, such as in response to some viral infections, and occasionally in non-B cells, at least in certain inflammation-associated neoplasic situations. The most recent findings on AID expression and function and their relevance to the generation of oncogenic lesions will be discussed.

  3. Multiple oncogenic viruses identified in Ocular surface squamous neoplasia in HIV-1 patients

    Directory of Open Access Journals (Sweden)

    Bisson Gregory

    2010-03-01

    Full Text Available Abstract Background Ocular surface squamous neoplasia (OSSN is a rare cancer that has increased in incidence with the HIV pandemic in Africa. The underlying cause of this cancer in HIV-infected patients from Botswana is not well defined. Results Tissues were obtained from 28 OSSN and 8 pterygia patients. The tissues analyzed from OSSN patients were 83% positive for EBV, 75% were HPV positive, 70% were KSHV positive, 75% were HSV-1/2 positive, and 61% were CMV positive by PCR. Tissues from pterygium patients were 88% positive for EBV, 75% were HPV positive, 50% were KSHV positive, and 60% were CMV positive. None of the patients were JC or BK positive. In situ hybridization and immunohistochemistry analyses further identified HPV, EBV, and KSHV in a subset of the tissue samples. Conclusion We identified the known oncogenic viruses HPV, KSHV, and EBV in OSSN and pterygia tissues. The presence of these tumor viruses in OSSN suggests that they may contribute to the development of this malignancy in the HIV population. Further studies are necessary to characterize the molecular mechanisms associated with viral antigens and their potential role in the development of OSSN.

  4. New strategies in metastatic melanoma: oncogene-defined taxonomy leads to therapeutic advances.

    Science.gov (United States)

    Flaherty, Keith T; Fisher, David E

    2011-08-01

    The discovery of BRAF and KIT mutations provided the first basis for a molecular classification of cutaneous melanoma on therapeutic grounds. As BRAF-targeted therapy quickly moves toward regulatory approval and incorporation as standard therapy for patients with metastatic disease, proof of concept has also been established for targeting mutated KIT in melanoma. NRAS mutations have long been known to be present in a subset of melanomas and represent an elusive subgroup for targeted therapies. Matching patient subgroups defined by genetic aberrations in the phosphoinositide 3-kinase and p16/cyclin dependent kinase 4 (CDK4) pathways with appropriate targeted therapies has not yet been realized. And, an increasing understanding of lineage-specific transcriptional regulators, most notably MITF, and how they may play a role in melanoma pathophysiology, has provided another axis to approach with therapies. The foundation has been established for individual oncogene targeting, and current investigations seek to understand the intersection of these susceptibilities and other described potential targets and pathways. The melanoma field stands poised to take the lead among cancer subtypes in advancing combination therapy strategies that simultaneously target multiple biologic underpinnings of the disease.

  5. Human Neuroblastoma: From Basic Science to Clinical Debut of Cellular Oncogenes

    Science.gov (United States)

    Schwab, Manfred

    Neuroblastoma is a childhood embryonic tumor of migrating neuroectodermal cells derived from the neural crest and destined for the adrenal medulla and the sympathetic nervous system. It very often has a rapidly progressive clinical course, and although many advances have been made in understanding the development of this tumor, improving the survival rates particularly in patients with metastatic tumor has been a frustrating experience. The mechanisms leading to neuroblastoma are largely unclear, but nonrandom chromosomal changes discovered early suggested the involvement of genetic alterations. Most prominent among these is the amplification of the oncogene MYCN, which identifies a group of patients who have a particularly dire prognosis. Amplified MYCN is used today as a prognostic marker on which therapy design is based to a large extent. An unusual aspect of neuroblastoma is the high rate at which tumors regress spontaneously, even in infants with extensive liver involvement and numerous subcutaneous nodules. Identifying the molecular and cellular basis of spontaneous regression could result in improved therapeutic approaches. Neuroblastoma is a model tumor with many fascinating aspects but has remained a challenge to the pediatric oncologist

  6. Chronic arsenic trioxide exposure leads to enhanced aggressiveness via Met oncogene addiction in cancer cells

    Science.gov (United States)

    Kryeziu, Kushtrim; Pirker, Christine; Englinger, Bernhard; van Schoonhoven, Sushilla; Spitzwieser, Melanie; Mohr, Thomas; Körner, Wilfried; Weinmüllner, Regina; Tav, Koray; Grillari, Johannes; Cichna-Markl, Margit; Berger, Walter; Heffeter, Petra

    2016-01-01

    As an environmental poison, arsenic is responsible for many cancer deaths. Paradoxically, arsenic trioxide (ATO) presents also a powerful therapy used to treat refractory acute promyelocytic leukemia (APL) and is intensively investigated for treatment of other cancer types. Noteworthy, cancer therapy is frequently hampered by drug resistance, which is also often associated with enhancement of tumor aggressiveness. In this study, we analyzed ATO-selected cancer cells (A2780ATO) for the mechanisms underlying their enhanced tumorigenicity and aggressiveness. These cells were characterized by enhanced proliferation and spheroid growth as well as increased tumorigenicity of xenografts in SCID mice. Noteworthy, subsequent studies revealed that overexpression of Met receptor was the underlying oncogenic driver of these effects, as A2780ATO cells were characterized by collateral sensitivity against Met inhibitors. This finding was also confirmed by array comparative genomic hybridization (array CGH) and whole genome gene expression arrays, which revealed that Met overexpression by chronic ATO exposure was based on the transcriptional regulation via activation of AP-1. Finally, it was shown that treatment with the Met inhibitor crizotinib was also effective against A2780ATO cell xenografts in vivo, indicating that targeting of Met presents a promising strategy for the treatment of Met-overexpressing tumors after either arsenic exposure or failure to ATO treatment. PMID:27036042

  7. Activated RET/PTC oncogene elicits immediate early and delayed response genes in PC12 cells.

    Science.gov (United States)

    Califano, D; Monaco, C; de Vita, G; D'Alessio, A; Dathan, N A; Possenti, R; Vecchio, G; Fusco, A; Santoro, M; de Franciscis, V

    1995-07-06

    The expression of the receptor-like tyrosine kinase RET is associated with tumors, tissues or cell lines of neural crest origin. In addition RET products (Ret) are involved in determining cell fate during the differentiation of the enteric nervous system and during renal organogenesis. However, as yet, no direct evidence exists to indicate that the Ret kinase activity might interfere in a specific way with cellular differentiation, or proliferation, of a neural crest derived cell line. By using two constitutively activated forms of RET (RET/PTC1 and RET/PTC3) in transient transfection experiments, we have obtained evidence that active RET could reprogramme the gene expression pattern in the rat pheochromocytoma PC12 cell line. Transcription driven by gene promoters, such as NGFI-A and vgf, which belong, respectively, to primary and delayed response genes to nerve growth factor (NGF), and by the neuron-specific enolase (NSE) promoter, is rapidly induced by the expression of activated RET oncogenes. This induction is not elicited in other non neural derived cell types tested. We also demonstrate that endogenous ras activity is required for RET induction of these neural markers. Finally, in the RET/PTC transfected PC12 cells, NGF is unable to induce further their transcription. This suggests that RET/PTC could share an intracellular signalling pathway with the NGF-receptor.

  8. STAT5-mediated expression of oncogenic miR-155 in cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    Kopp, Katharina L; Ralfkiaer, Ulrik; Gjerdrum, Lise Mette R

    2013-01-01

    show that malignant T cells constitutively express high levels of miR-155 and its host gene BIC (B cell integration cluster). Using ChIP-seq, we identify BIC as a target of transcription factor STAT5, which is aberrantly activated in malignant T cells and induced by IL-2/IL-15 in non-malignant T cells....... Incubation with JAK inhibitor or siRNA-mediated knockdown of STAT5 decreases BIC/miR-155 expression, whereas IL-2 and IL-15 increase their expression in cell lines and primary cells. In contrast, knockdown of STAT3 has no effect, and BIC is not a transcriptional target of STAT3, indicating that regulation...... of BIC/miR-155 expression by STAT5 is highly specific. Malignant proliferation is significantly inhibited by an antisense-miR-155 as well as by knockdown of STAT5 and BIC.   In conclusion, we provide the first evidence that STAT5 drives expression of oncogenic BIC/miR-155 in cancer. Moreover, our data...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Efficient oncogene silencing and metastasis inhibition via systemic delivery of siRNA.

    Science.gov (United States)

    Li, Shyh-Dar; Chono, Sumio; Huang, Leaf

    2008-05-01

    The selective delivery of small interfering RNA (siRNA) to metastatic tumors remains a challenging task. We have developed a nanoparticle (NP) formulation composed of siRNA, a carrier DNA, a polycationic peptide, and cationic liposomes. The NP was obtained by a self-assembling process, followed by surface modification with a polyethylene glycol (PEG)-conjugated ligand, anisamide. The NP was PEGylated and a ligand was presented to target sigma receptor-expressing murine melanoma cells, B16F10. The lung metastasis model was established by intravenous (i.v.) injection of the B16F10 cells into C57BL/6 mice. A mixture of siRNA against MDM2, c-myc, and vascular endothelial growth factor (VEGF) co-formulated in the targeted NP caused simultaneous silencing of each of the oncogenes in the metastatic nodules. Two consecutive i.v. injections of siRNA in the targeted NP significantly reduced the lung metastasis (approximately 70-80%) at a relatively low dose (0.45 mg/kg), whereas free siRNA and the nontargeted NP showed little effect. This targeted NP formulation significantly prolonged the mean survival time of the animals by 30% as compared to the untreated controls. At the therapeutic dose, the targeted NP showed little local and systemic immunotoxicity and did not decrease the body weight or damage the major organs.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  13. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Oncogenic KRAS activates an embryonic stem cell-like program in human colon cancer initiation.

    Science.gov (United States)

    Le Rolle, Anne-France; Chiu, Thang K; Zeng, Zhaoshi; Shia, Jinru; Weiser, Martin R; Paty, Philip B; Chiu, Vi K

    2016-01-19

    Colorectal cancer is the third most frequently diagnosed cancer worldwide. Prevention of colorectal cancer initiation represents the most effective overall strategy to reduce its associated morbidity and mortality. Activating KRAS mutation (KRASmut) is the most prevalent oncogenic driver in colorectal cancer development, and KRASmut inhibition represents an unmet clinical need. We apply a systems-level approach to study the impact of KRASmut on stem cell signaling during human colon cancer initiation by performing gene set enrichment analysis on gene expression from human colon tissues. We find that KRASmut imposes the embryonic stem cell-like program during human colon cancer initiation from colon adenoma to stage I carcinoma. Expression of miR145, an embryonic SC program inhibitor, promotes cell lineage differentiation marker expression in KRASmut colon cancer cells and significantly suppresses their tumorigenicity. Our data support an in vivo plasticity model of human colon cancer initiation that merges the intrinsic stem cell properties of aberrant colon stem cells with the embryonic stem cell-like program induced by KRASmut to optimize malignant transformation. Inhibition of the embryonic SC-like program in KRASmut colon cancer cells reveals a novel therapeutic strategy to programmatically inhibit KRASmut tumors and prevent colon cancer.

  19. 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

  20. 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.

  1. Proto-oncogene PBF/PTTG1IP regulates thyroid cell growth and represses radioiodide treatment.

    Science.gov (United States)

    Read, Martin L; Lewy, Greg D; Fong, Jim C W; Sharma, Neil; Seed, Robert I; Smith, Vicki E; Gentilin, Erica; Warfield, Adrian; Eggo, Margaret C; Knauf, Jeffrey A; Leadbeater, Wendy E; Watkinson, John C; Franklyn, Jayne A; Boelaert, Kristien; McCabe, Christopher J

    2011-10-01

    Pituitary tumor transforming gene (PTTG)-binding factor (PBF or PTTG1IP) is a little characterized proto-oncogene that has been implicated in the etiology of breast and thyroid tumors. In this study, we created a murine transgenic model to target PBF expression to the thyroid gland (PBF-Tg mice) and found that these mice exhibited normal thyroid function, but a striking enlargement of the thyroid gland associated with hyperplastic and macrofollicular lesions. Expression of the sodium iodide symporter (NIS), a gene essential to the radioiodine ablation of thyroid hyperplasia, neoplasia, and metastasis, was also potently inhibited in PBF-Tg mice. Critically, iodide uptake was repressed in primary thyroid cultures from PBF-Tg mice, which could be rescued by PBF depletion. PBF-Tg thyroids exhibited upregulation of Akt and the TSH receptor (TSHR), each known regulators of thyrocyte proliferation, along with upregulation of the downstream proliferative marker cyclin D1. We extended and confirmed findings from the mouse model by examining PBF expression in human multinodular goiters (MNG), a hyperproliferative thyroid disorder, where PBF and TSHR was strongly upregulated relative to normal thyroid tissue. Furthermore, we showed that depleting PBF in human primary thyrocytes was sufficient to increase radioiodine uptake. Together, our findings indicate that overexpression of PBF causes thyroid cell proliferation, macrofollicular lesions, and hyperplasia, as well as repression of the critical therapeutic route for radioiodide uptake.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Oncogenic roles of PRL-3 in FLT3-ITD induced acute myeloid leukaemia.

    Science.gov (United States)

    Park, Jung Eun; Yuen, Hiu Fung; Zhou, Jian Biao; Al-Aidaroos, Abdul Qader O; Guo, Ke; Valk, Peter J; Zhang, Shu Dong; Chng, Wee Joo; Hong, Cheng William; Mills, Ken; Zeng, Qi

    2013-09-01

    FLT3-ITD mutations are prevalent mutations in acute myeloid leukaemia (AML). PRL-3, a metastasis-associated phosphatase, is a downstream target of FLT3-ITD. This study investigates the regulation and function of PRL-3 in leukaemia cell lines and AML patients associated with FLT3-ITD mutations. PRL-3 expression is upregulated by the FLT3-STAT5 signalling pathway in leukaemia cells, leading an activation of AP-1 transcription factors via ERK and JNK pathways. PRL-3-depleted AML cells showed a significant decrease in cell growth. Clinically, high PRL-3 mRNA expression was associated with FLT3-ITD mutations in four independent AML datasets with 1158 patients. Multivariable Cox-regression analysis on our Cohort 1 with 221 patients identified PRL-3 as a novel prognostic marker independent of other clinical parameters. Kaplan-Meier analysis showed high PRL-3 mRNA expression was significantly associated with poorer survival among 491 patients with normal karyotype. Targeting PRL-3 reversed the oncogenic effects in FLT3-ITD AML models in vitro and in vivo. Herein, we suggest that PRL-3 could serve as a prognostic marker to predict poorer survival and as a promising novel therapeutic target for AML patients.

  4. Fyn and Src are Effectors of Oncogenic EGFR Signaling in Glioblastoma Patients

    Science.gov (United States)

    Lu, Kan V.; Zhu, Shaojun; Cvrljevic, Anna; Huang, Tiffany T.; Sarkaria, Shawn; Ahkavan, David; Dang, Julie; Dinca, Eduard B.; Plaisier, Seema B.; Oderberg, Isaac; Lee, Yohan; Chen, Zugen; Caldwell, Jeremy S.; Xie, Yongmin; Loo, Joseph A.; Seligson, David; Chakravari, Arnab; Lee, Francis Y.; Weinmann, Roberto; Cloughesy, Timothy F.; Nelson, Stanley F.; Bergers, Gabriele; Graeber, Thomas; Furnari, Frank B.; James, C. David; Cavenee, Webster K.; Johns, Terrance G.; Mischel, Paul S.

    2009-01-01

    Activating EGFR mutations are common in many cancers including glioblastoma. However, clinical responses to EGFR inhibitors are infrequent and short-lived. We demonstrate that the Src family kinases (SFKs) Fyn and Src are effectors of oncogenic EGFR signaling, enhancing invasion and tumor cell survival in vivo. Expression of a constitutively active EGFR mutant, EGFRvIII, resulted in activating phosphorylation and physical association with Src and Fyn, promoting tumor growth and motility. Gene silencing of Fyn and Src limited EGFR and EGFRvIII-dependent tumor cell motility. The SFK inhibitor dasatinib inhibited invasion, promoted tumor regression and induced apoptosis in vivo, significantly prolonging survival of an orthotopic glioblastoma model expressing endogenous EGFRvIII. Dasatinib enhanced the efficacy of an anti-EGFR monoclonal antibody (mAb 806) in vivo, further limiting tumor growth and extending survival. Examination of a large cohort of clinical samples demonstrated frequent coactivation of EGFR and SFKs in glioblastoma patients. These results establish a mechanism linking EGFR signaling with Fyn and Src activation to promote tumor progression and invasion in vivo and provide rationale for combined anti-EGFR and anti-SFK targeted therapies. PMID:19690143

  5. Proto-oncogene PBF/PTTG1IP regulates thyroid cell growth and represses radioiodide treatment

    Science.gov (United States)

    Read, Martin L.; Lewy, Greg D.; Fong, Jim C.W.; Sharma, Neil; Seed, Robert I.; Smith, Vicki E.; Gentilin, Erica; Warfield, Adrian; Eggo, Margaret C.; Knauf, Jeffrey A.; Leadbeater, Wendy E.; Watkinson, John C.; Franklyn, Jayne A.; Boelaert, Kristien; McCabe, Christopher J.

    2011-01-01

    PTTG Binding Factor (PBF or PTTG1IP) is a little characterised proto-oncogene that has been implicated in the etiology of breast and thyroid tumors. In this study, we created a murine transgenic model to target PBF expression to the thyroid gland (PBF-Tg mice) and found that these mice exhibited normal thyroid function but a striking enlargement of the thyroid gland associated with hyperplastic and macrofollicular lesions. Expression of the sodium iodide symporter (NIS), a gene essential to the radioiodine ablation of thyroid hyperplasia, neoplasia and metastasis, was also potently inhibited in PBF-Tg mice. Critically, iodide uptake was repressed in primary thyroid cultures from PBF-Tg mice, which could be rescued by PBF depletion. PBF-Tg thyroids exhibited upregulation of Akt and the TSH receptor (TSHR), each known regulators of thyrocyte proliferation, along with upregulation of the downstream proliferative marker cyclin D1. We extended and confirmed findings from the mouse model by examining PBF expression in human multinodular goitres (MNG), a hyperproliferative thyroid disorder, where PBF and TSHR was strongly upregulated relative to normal thyroid tissue. Further, we showed that depleting PBF in human primary thyrocytes was sufficient to increase radioiodine uptake. Together, our findings indicate that overexpression of PBF causes thyroid cell proliferation, macrofollicular lesions and hyperplasia, as well as repression of the critical therapeutic route for radioiodide uptake. PMID:21844185

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

    Directory of Open Access Journals (Sweden)

    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

  7. 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.

  8. 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.

  9. Mutant AKT1-E17K is oncogenic in lung epithelial cells

    Science.gov (United States)

    De Marco, Carmela; Malanga, Donatella; Rinaldo, Nicola; De Vita, Fernanda; Scrima, Marianna; Lovisa, Sara; Fabris, Linda; Carriero, Maria Vincenza; Franco, Renato; Rizzuto, Antonia; Baldassarre, Gustavo; Viglietto, Giuseppe

    2015-01-01

    The hotspot E17K mutation in the pleckstrin homology domain of AKT1 occurs in approximately 0.6–2% of human lung cancers. In this manuscript, we sought to determine whether this AKT1 variant is a bona-fide activating mutation and plays a role in the development of lung cancer. Here we report that in immortalized human bronchial epithelial cells (BEAS-2B cells) mutant AKT1-E17K promotes anchorage-dependent and -independent proliferation, increases the ability to migrate, invade as well as to survive and duplicate in stressful conditions, leading to the emergency of cells endowed with the capability to form aggressive tumours at high efficiency. We provide also evidence that the molecular mechanism whereby AKT1-E17K is oncogenic in lung epithelial cells involves phosphorylation and consequent cytoplasmic delocalization of the cyclin-dependent kinase (cdk) inhibitor p27. In agreement with these results, cytoplasmic p27 is preferentially observed in primary NSCLCs with activated AKT and predicts poor survival. PMID:26053093

  10. 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.

  11. The putative oncogene Pim-1 in the mouse: its linkage and variation among t haplotypes.

    Science.gov (United States)

    Nadeau, J H; Phillips, S J

    1987-11-01

    Pim-1, a putative oncogene involved in T-cell lymphomagenesis, was mapped between the pseudo-alpha globin gene Hba-4ps and the alpha-crystallin gene Crya-1 on mouse chromosome 17 and therefore within the t complex. Pim-1 restriction fragment variants were identified among t haplotypes. Analysis of restriction fragment sizes obtained with 12 endonucleases demonstrated that the Pim-1 genes in some t haplotypes were indistinguishable from the sizes for the Pim-1b allele in BALB/c inbred mice. There are now three genes, Pim-1, Crya-1 and H-2 I-E, that vary among independently derived t haplotypes and that have indistinguishable alleles in t haplotypes and inbred strains. These genes are closely linked within the distal inversion of the t complex. Because it is unlikely that these variants arose independently in t haplotypes and their wild-type homologues, we propose that an exchange of chromosomal segments, probably through double crossingover, was responsible for indistinguishable Pim-1 genes shared by certain t haplotypes and their wild-type homologues. There was, however, no apparent association between variant alleles of these three genes among t haplotypes as would be expected if a single exchange introduced these alleles into t haplotypes. If these variant alleles can be shown to be identical to the wild-type allele, then lack of association suggests that multiple exchanges have occurred during the evolution of the t complex.

  12. Ras Oncogene-Mediated Progressive Silencing of Extracellular Superoxide Dismutase in Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Francesca Cammarota

    2015-01-01

    Full Text Available Extracellular superoxide dismutase (SOD3 is a secreted enzyme that uses superoxide anion as a substrate in a dismutase reaction that results in the formation of hydrogen peroxide. Both of these reactive oxygen species affect growth signaling in cells. Although SOD3 has growth-supporting characteristics, the expression of SOD3 is downregulated in epithelial cancer cells. In the current work, we studied the mechanisms regulating SOD3 expression in vitro using thyroid cell models representing different stages of thyroid cancer. We demonstrate that a low level of RAS activation increases SOD3 mRNA synthesis that then gradually decreases with increasing levels of RAS activation and the decreasing degree of differentiation of the cancer cells. Our data indicate that SOD3 regulation can be divided into two classes. The first class involves RAS–driven reversible regulation of SOD3 expression that can be mediated by the following mechanisms: RAS GTPase regulatory genes that are responsible for SOD3 self-regulation; RAS-stimulated p38 MAPK activation; and RAS-activated increased expression of the mir21 microRNA, which inversely correlates with sod3 mRNA expression. The second class involves permanent silencing of SOD3 mediated by epigenetic DNA methylation in cells that represent more advanced cancers. Therefore, the work suggests that SOD3 belongs to the group of ras oncogene-silenced genes.

  13. 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.

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

    Science.gov (United States)

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

    2015-10-27

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

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Mouse transplant models for evaluating the oncogenic risk of a self-inactivating XSCID lentiviral vector.

    Directory of Open Access Journals (Sweden)

    Sheng Zhou

    Full Text Available Hematopoietic stem cell gene therapy requires the use of integrating retroviral vectors in order to stably transmit a therapeutic gene to mature blood cells. Human clinical trials have shown that some vector integration events lead to disrupted regulation of proto-oncogenes resulting in disordered hematopoiesis including T-cell leukemia. Newer vectors have been designed to decrease the incidence of these adverse events but require appropriate pre-clinical assays to demonstrate safety. We have used two distinct mouse serial transplant assays to evaluate the safety of a self-inactivating lentiviral vector intended for use in X-linked severe combined immunodeficiency (XSCID gene therapy trials. These experiments entailed 28 months of total follow-up and included 386 mice. There were no cases in which the XSCID lentiviral vector clearly caused hematopoietic malignancies, although a single case of B cell malignancy was observed that contained the lentiviral vector as a likely passenger event. In contrast, a SFFV-DsRed γ-retroviral vector resulted in clonal transformation events in multiple secondary recipients. Non-specific pathology not related to vector insertions was noted including T cell leukemias arising from irradiated recipient cells. Overall, this comprehensive study of mouse transplant safety assays demonstrate the relative safety of the XSCID lentiviral vector but also highlight the limitations of these assays.

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

    Science.gov (United States)

    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.

  20. H-Ras Oncogene Expression and Angiogenesis in Experimental Liver Cirrhosis

    Directory of Open Access Journals (Sweden)

    Gülsüm Özlem Elpek

    2013-01-01

    Full Text Available Background. Proto-oncogenes, particularly ras, may not only affect cell proliferation but also contribute to angiogenesis by influencing both proangiogenic and antiangiogenic mediators. The aim of this study was to investigate whether any relationship exists between ras expression and angiogenesis during diethylnitrosamine- (DEN- induced experimental liver fibrosis. Materials and Methods. Liver cirrhosis was induced in rats by intraperitoneal injections of DEN. The animals were sacrificed 2 weeks after the last administrations and a hepatectomy was performed. Masson’s trichrome staining was used in the evaluation of the extent of liver fibrosis. The vascular density in portal and periportal areas was assessed by determining the count of CD34 labeled vessel sections. For quantitative evaluation of H-ras expression, in each section positive and negative cells were counted. Results. In fibrotic group H-ras expression was higher than that in nonfibrotic group and was more widespread in cirrhotic livers. Friedman’s test showed that there was a significant correlation between H-ras expression and VD (P<0.01. Conclusion. The results of this descriptive study reveal that H-ras expression gradually increases according to the severity of fibrosis and strongly correlates with angiogenesis.

  1. A universal assay for detection of oncogenic fusion transcripts by oligo microarray analysis

    Directory of Open Access Journals (Sweden)

    Ribeiro Franclim R

    2009-01-01

    Full Text Available Abstract Background The ability to detect neoplasia-specific fusion genes is important not only in cancer research, but also increasingly in clinical settings to ensure that correct diagnosis is made and the optimal treatment is chosen. However, the available methodologies to detect such fusions all have their distinct short-comings. Results We describe a novel oligonucleotide microarray strategy whereby one can screen for all known oncogenic fusion transcripts in a single experiment. To accomplish this, we combine measurements of chimeric transcript junctions with exon-wise measurements of individual fusion partners. To demonstrate the usefulness of the approach, we designed a DNA microarray containing 68,861 oligonucleotide probes that includes oligos covering all combinations of chimeric exon-exon junctions from 275 pairs of fusion genes, as well as sets of oligos internal to all the exons of the fusion partners. Using this array, proof of principle was demonstrated by detection of known fusion genes (such as TCF3:PBX1, ETV6:RUNX1, and TMPRSS2:ERG from all six positive controls consisting of leukemia cell lines and prostate cancer biopsies. Conclusion This new method bears promise of an important complement to currently used diagnostic and research tools for the detection of fusion genes in neoplastic diseases.

  2. NOTCH receptors in gastric and other gastrointestinal cancers: oncogenes or tumor suppressors?

    Science.gov (United States)

    Huang, Tingting; Zhou, Yuhang; Cheng, Alfred S L; Yu, Jun; To, Ka Fai; Kang, Wei

    2016-12-09

    Gastric cancer (GC) ranks the most common cancer types and is one of the leading causes of cancer-related death. Due to delayed diagnosis and high metastatic frequency, 5-year survival rate of GC is rather low. It is a complex disease resulting from the interaction between environmental factors and host genetic alterations that deregulate multiple signaling pathways. The Notch signaling pathway, a highly conserved system in the regulation of the fate in several cell types, plays a pivotal role in cell differentiation, survival and proliferation. Notch is also one of the most commonly activated signaling pathways in tumors and its aberrant activation plays a key role in cancer advancement. Whether Notch cascade exerts oncogenic or tumor suppressive function in different cancer types depends on the cellular context. Mammals have four NOTCH receptors that modulate Notch pathway activity. In this review, we provide a comprehensive summary on the functional role of NOTCH receptors in gastric and other gastrointestinal cancers. Increasing knowledge of NOTCH receptors in gastrointestinal cancers will help us recognize the underlying mechanisms of Notch signaling and develop novel therapeutic strategies for GC.

  3. Exosomes enriched in stemness/metastatic-related mRNAS promote oncogenic potential in breast cancer.

    Science.gov (United States)

    Rodríguez, Marta; Silva, Javier; Herrera, Alberto; Herrera, Mercedes; Peña, Cristina; Martín, Paloma; Gil-Calderón, Beatriz; Larriba, María Jesús; Coronado, M Josés; Soldevilla, Beatriz; Turrión, Víctor S; Provencio, Mariano; Sánchez, Antonio; Bonilla, Félix; García-Barberán, Vanesa

    2015-12-01

    Cancer cells efficiently transfer exosome contents (essentially mRNAs and microRNAs) to other cell types, modifying immune responses, cell growth, angiogenesis and metastasis. Here we analyzed the exosomes release by breast tumor cells with different capacities of stemness/metastasis based on CXCR4 expression, and evaluated their capacity to generate oncogenic features in recipient cells. Breast cancer cells overexpressing CXCR4 showed an increase in stemness-related markers, and in proliferation, migration and invasion capacities. Furthermore, recipient cells treated with exosomes from CXCR4-cells showed increased in the same abilities. Moreover, inoculation of CXCR4-cell-derived exosomes in immunocompromised mice stimulated primary tumor growth and metastatic potential. Comparison of nucleic acids contained into exosomes isolated from patients revealed a "stemness and metastatic" signature in exosomes of patients with worse prognosis. Finally, our data supported the view that cancer cells with stem-like properties show concomitant metastatic behavior, and their exosomes stimulate tumor progression and metastasis. Exosomes-derived nucleic acids from plasma of breast cancer patients are suitable markers in the prognosis of such patients.

  4. Targeting oncogenic KRAS in non-small cell lung cancer cells by phenformin inhibits growth and angiogenesis

    OpenAIRE

    2015-01-01

    Tumors require a vascular supply to grow and can achieve this via the expression of pro-angiogenic growth factors. Many potential oncogenic mutations have been identified in tumor angiogenesis. Somatic mutations in the small GTPase KRAS are the most common activating lesions found in human cancer, and are generally associated with poor response to standard therapies. Biguanides, such as the diabetes therapeutics metformin and phenformin, have demonstrated anti-tumor activity both in vitro and...

  5. A novel oncogenic BTK isoform is overexpressed in colon cancers and required for RAS-mediated transformation

    DEFF Research Database (Denmark)

    Grassilli, E; Pisano, F; Cialdella, A

    2016-01-01

    Bruton's tyrosine kinase (BTK) is essential for B-cell proliferation/differentiation and it is generally believed that its expression and function are limited to bone marrow-derived cells. Here, we report the identification and characterization of p65BTK, a novel isoform abundantly expressed in c...... therapeutic approach.Oncogene advance online publication, 25 January 2016; doi:10.1038/onc.2015.504....

  6. Oncogene amplification detected by in situ hybridization in radiation induced rat skin tumors. [C-myc:a3

    Energy Technology Data Exchange (ETDEWEB)

    Yi Jin.

    1991-02-01

    Oncogene activation may play an important role in radiation induced carcinogenesis. C-myc oncogene amplification was detected by in situ hybridization in radiation-induced rat skin tumors, including squamous and basal cell carcinomas. In situ hybridization was performed with a biotinylated human c-myc third exon probe, visualized with an avidin-biotinylated alkaline phosphate detection system. No c-myc oncogene amplification was detected in normal rat skin at very early times after exposure to ionizing radiation, which is consistent with the view that c-myc amplification is more likely to be related to carcinogenesis than to normal cell proliferation. The incorporation of tritiated thymidine into the DNA of rat skin cells showed that the proliferation of epidermal cells reached a peak on the seventh day after exposure to ionizing radiation and then decreased. No connection between the proliferation of epidermal cell and c-myc oncogene amplification in normal or irradiated rat skin was found. The results indicated that c-myc amplification as measured by in situ hybridization was correlated with the Southern bolt results, but only some of the cancer cells were amplified. The c-myc positive cells were distributed randomly within regions of the tumor and exhibited a more uniform nuclear structure in comparison to the more vacuolated c-myc negative cells. No c-myc signal was detected in unirradiated normal skin or in irradiated skin cells near the tumors. C-myc amplification appears to be cell or cell cycle specific within radiation-induced carcinomas. 28 refs., 3 figs., 3 tabs.

  7. Distinct anti-oncogenic effect of various microRNAs in different mouse models of liver cancer.

    Science.gov (United States)

    Tao, Junyan; Ji, Junfang; Li, Xiaolei; Ding, Ning; Wu, Heng; Liu, Yan; Wang, Xin Wei; Calvisi, Diego F; Song, Guisheng; Chen, Xin

    2015-03-30

    Deregulation of microRNAs (miRNAs) is a typical feature of human hepatocellular carcinoma (HCC). However, the in vivo relevance of miRNAs along hepatocarcinogenesis remains largely unknown. Here, we show that liver tumors induced in mice by c-Myc overexpression or AKT/Ras co-expression exhibit distinct miRNA expression profiles. Among the downregulated miRNAs, eight (miR-101, miR-107, miR-122, miR-29, miR-365, miR-375, miR-378, and miR-802) were selected and their tumor suppressor activity was determined by overexpressing each of them together with c-Myc or AKT/Ras oncogenes in mouse livers via hydrodynamic transfection. The tumor suppressor activity of these microRNAs was extremely heterogeneous in c-Myc and AKT/Ras mice: while miR-378 had no tumor suppressor activity, miR-107, mir-122, miR-29, miR-365 and miR-802 exhibited weak to moderate tumor suppressor potential. Noticeably, miR-375 showed limited antineoplastic activity against c-Myc driven tumorigenesis, whereas it strongly inhibited AKT/Ras induced hepatocarcinogenesis. Furthermore, miR-101 significantly suppressed both c-Myc and AKT/Ras liver tumor development. Altogether, the present data demonstrate that different oncogenes induce distinct miRNA patterns, whose modulation differently affects hepatocarcinogenesis depending on the driving oncogenes. Finally, our findings support a strong tumor suppressor activity of miR-101 in liver cancer models regardless of the driver oncogenes involved, thus representing a promising therapeutic target in human HCC.

  8. The Importance of Identification of M-BCRABL Oncogene and JAK2V617F Mutation in Myeloproliferative Neoplasms

    Directory of Open Access Journals (Sweden)

    Szántó Annamária

    2014-04-01

    Full Text Available Background: The elucidation of the genetic background of the myeloproliferative neoplasms completely changed the management of these disorders: the presence of the Philadelphia chromosome and/or the BCR-ABL oncogene is pathognomonic for chronic myeloid leukemia and identification of JAK2 gene mutations are useful in polycytemia vera (PV, essential thrombocytemia (ET and myelofibrosis (PMF. The aim of this study was to investigate the role of molecular biology tests in the management of myeloproliferative neoplasms.

  9. Two novel genital human papillomavirus (HPV) types, HPV68 and HPV70, related to the potentially oncogenic HPV39.

    OpenAIRE

    Longuet, M; Beaudenon, S; Orth, G

    1996-01-01

    The genomes of two novel human papillomavirus (HPV) types, HPV68 and HPV70, were cloned from a low-grade cervical intraepithelial neoplasia and a vulvar papilloma, respectively, and partially sequenced. Both types are related to HPV39, a potentially oncogenic virus. HPV68 and HPV70 were also detected in genital intraepithelial neoplasia from three patients and one patient, respectively. Comparison with sequence data in the literature indicates that the subgenomic ME180-HPV DNA fragment, clone...

  10. 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...

  11. Synergistic Induction of Potential Warburg Effect in Zebrafish Hepatocellular Carcinoma by Co-Transgenic Expression of Myc and xmrk Oncogenes.

    Directory of Open Access Journals (Sweden)

    Zhen Li

    Full Text Available Previously we have generated inducible liver tumor models by transgenic expression of Myc or xmrk (activated EGFR homolog oncogenes in zebrafish. To investigate the interaction of the two oncogenes, we crossed the two transgenic lines and observed more severe and faster hepatocarcinogenesis in Myc/xmrk double transgenic zebrafish than either single transgenic fish. RNA-Seq analyses revealed distinct changes in many molecular pathways among the three types of liver tumors. In particular, we found dramatic alteration of cancer metabolism based on the uniquely enriched pathways in the Myc/xmrk tumors. Critical glycolytic genes including hk2, pkm and ldha were significantly up-regulated in Myc/xmrk tumors but not in either single oncogene-induced tumors, suggesting a potential Warburg effect. In RT-qPCR analyses, the specific pkm2 isoformin Warburg effect was found to be highly enriched in the Myc/xmrk tumors but not in Myc or xmrk tumors, consistent with the observations in many human cancers with Warburg effect. Moreover, the splicing factor genes (hnrnpa1, ptbp1a, ptbp1b and sfrs3b responsible for generating the pkm isoform were also greatly up-regulated in the Myc/xmrk tumors. As Pkm2 isoform is generally inactive and causes incomplete glycolysis to favor anabolism and tumor growth, by treatment with a Pkm2-specific activator, TEPP-46, we further demonstrated that activation of Pkm2 suppressed the growth of oncogenic liver as well as proliferation of liver cells. Collectively, our Myc/xmrk zebrafish model suggests synergetic effect of EGFR and MYC in triggering Warburg effect in the HCC formation and may provide a promising in vivo model for Warburg effect.

  12. Testing the Oncogenic Relevance of Cell Adhesion and Cytosketal Genes Affected by DNA Deletions in Breast Cancer

    Science.gov (United States)

    2010-07-01

    and hair follicle derived cells as targets for the v-rasHa oncogene in mouse skin carcinogenesis. Carcinogenesis 12, 1119–1124. Wicki, A., Lehembre, F...were genomically altered in human cancer, and thus potential “driver” genes that could, if validated, represent new therapeutic targets or suggest...sequences targeting TSPAN31 (Huesken, Lange et al. 2005), and have found one hairpin that is effective in knocking down expression of TSPAN31 in the

  13. Dependence of Intracellular and Exosomal microRNAs on Viral E6/E7 Oncogene Expression in HPV-positive Tumor Cells: e1004712

    National Research Council Canada - National Science Library

    Anja Honegger; Daniela Schilling; Sandra Bastian; Jasmin Sponagel; Vladimir Kuryshev; Holger Sültmann; Martin Scheffner; Karin Hoppe-Seyler; Felix Hoppe-Seyler

    2015-01-01

    ...) expression patterns. By genome-wide analyses, we investigate whether the intracellular and exosomal miRNA compositions of HPV-positive cancer cells are dependent on endogenous E6/E7 oncogene expression...

  14. Dependence of intracellular and exosomal microRNAs on viral E6/E7 oncogene expression in HPV-positive tumor cells

    National Research Council Canada - National Science Library

    Honegger, Anja; Schilling, Daniela; Bastian, Sandra; Sponagel, Jasmin; Kuryshev, Vladimir; Sültmann, Holger; Scheffner, Martin; Hoppe-Seyler, Karin; Hoppe-Seyler, Felix

    2015-01-01

    ...) expression patterns. By genome-wide analyses, we investigate whether the intracellular and exosomal miRNA compositions of HPV-positive cancer cells are dependent on endogenous E6/E7 oncogene expression...

  15. Dissection of the Oncogenic MYCN Transcriptional Network Reveals a Large Set of Clinically Relevant Cell Cycle Genes as Drivers of Neuroblastoma Tumorigenesis

    NARCIS (Netherlands)

    D.M. Murphy; P.G. Buckley; K. Bryan; K.M. Watters; J. Koster; P. van Sluis; J. Molenaar; R. Versteeg; R.L. Stallings

    2011-01-01

    Amplification of the oncogenic transcription factor MYCN plays a major role in the pathogenesis of several pediatric cancers, including neuroblastoma, medulloblastoma, and rhabodomyosarcoma. For neuroblastoma, MYCN amplification is the most powerful genetic predictor of poor patient survival, yet th

  16. Blocking of p53-Snail Binding, Promoted by Oncogenic K-Ras, Recovers p53 Expression and function

    Directory of Open Access Journals (Sweden)

    Sun-Hye Lee

    2009-01-01

    Full Text Available Differentially from other kinds of Ras, oncogenic K-Ras, which is mutated approximately 30% of human cancer, does not induce apoptosis and senescence. Here, we provide the evidence that oncogenic K-Ras abrogates p53 function and expression through induction of Ataxia telangiectasia-mutated and Rad3-related mediated Snail stabilization. Snail directly binds to DNA binding domain of p53 and diminishes the tumor-suppressive function of p53. Thus, elimination of Snail through si-RNA can induce p53 in K-Ras-mutated cells, whereas Snail and mutant K-Ras can suppress p53 in regardless of K-Ras status. Chemicals, isolated from inhibitor screening of p53-Snail binding, can block the Snail-mediated p53 suppression and enhance the expression of p53 as well as the transcriptional activity of p53 in an oncogenic K-Ras-dependent manner. Among the chemicals, two are very similar in structure. These results can answer why K-Ras can coexist with wild type p53 and propose the Snail-p53 binding as the new therapeutic target for K-Ras-mutated cancers including pancreatic, lung, and colon cancers.

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

    Science.gov (United States)

    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.

  18. Immortality, but not oncogenic transformation, of primary human cells leads to epigenetic reprogramming of DNA methylation and gene expression.

    Science.gov (United States)

    Gordon, Katrina; Clouaire, Thomas; Bao, Xun X; Kemp, Sadie E; Xenophontos, Maria; de Las Heras, Jose Ignacio; Stancheva, Irina

    2014-04-01

    Tumourigenic transformation of normal cells into cancer typically involves several steps resulting in acquisition of unlimited growth potential, evasion of apoptosis and non-responsiveness to growth inhibitory signals. Both genetic and epigenetic changes can contribute to cancer development and progression. Given the vast genetic heterogeneity of human cancers and difficulty to monitor cancer-initiating events in vivo, the precise relationship between acquisition of genetic mutations and the temporal progression of epigenetic alterations in transformed cells is largely unclear. Here, we use an in vitro model system to investigate the contribution of cellular immortality and oncogenic transformation of primary human cells to epigenetic reprogramming of DNA methylation and gene expression. Our data demonstrate that extension of replicative life span of the cells is sufficient to induce accumulation of DNA methylation at gene promoters and large-scale changes in gene expression in a time-dependent manner. In contrast, continuous expression of cooperating oncogenes in immortalized cells, although essential for anchorage-independent growth and evasion of apoptosis, does not affect de novo DNA methylation at promoters and induces subtle expression changes. Taken together, these observations imply that cellular immortality promotes epigenetic adaptation to highly proliferative state, whereas transforming oncogenes confer additional properties to transformed human cells.

  19. Mitotic Stress Is an Integral Part of the Oncogene-Induced Senescence Program that Promotes Multinucleation and Cell Cycle Arrest

    Directory of Open Access Journals (Sweden)

    Dina Dikovskaya

    2015-09-01

    Full Text Available Oncogene-induced senescence (OIS is a tumor suppression mechanism that blocks cell proliferation in response to oncogenic signaling. OIS is frequently accompanied by multinucleation; however, the origin of this is unknown. Here, we show that multinucleate OIS cells originate mostly from failed mitosis. Prior to senescence, mutant H-RasV12 activation in primary human fibroblasts compromised mitosis, concordant with abnormal expression of mitotic genes functionally linked to the observed mitotic spindle and chromatin defects. Simultaneously, H-RasV12 activation enhanced survival of cells with damaged mitoses, culminating in extended mitotic arrest and aberrant exit from mitosis via mitotic slippage. ERK-dependent transcriptional upregulation of Mcl1 was, at least in part, responsible for enhanced survival and slippage of cells with mitotic defects. Importantly, mitotic slippage and oncogene signaling cooperatively induced senescence and key senescence effectors p21 and p16. In summary, activated Ras coordinately triggers mitotic disruption and enhanced cell survival to promote formation of multinucleate senescent cells.

  20. Dysfunctional telomeres promote genomic instability and metastasis in the absence of telomerase activity in oncogene induced mammary cancer.

    Science.gov (United States)

    Bojovic, Bojana; Crowe, David L

    2013-02-01

    Telomerase is a ribonucleoprotein that maintains the ends of chromosomes (telomeres). In normal cells lacking telomerase activity, telomeres shorten with each cell division because of the inability to completely synthesize the lagging strand. Critically shortened telomeres elicit DNA damage responses and limit cellular division and lifespan, providing an important tumor suppressor function. Most human cancer cells express telomerase which contributes significantly to the tumor phenotype. In human breast cancer, telomerase expression is predictive of clinical outcomes such as lymph node metastasis and survival. In mouse models of mammary cancer, telomerase expression is also upregulated. Telomerase overexpression resulted in spontaneous mammary tumor development in aged female mice. Increased mammary cancer also was observed when telomerase deficient mice were crossed with p53 null mutant animals. However, the effects of telomerase and telomere length on oncogene driven mammary cancer have not been completely characterized. To address these issues we characterized neu proto-oncogene driven mammary tumor formation in G1 Terc-/- (telomerase deficient with long telomeres), G3 Terc-/- (telomerase deficient with short telomeres), and Terc+/+ mice. Telomerase deficiency reduced the number of mammary tumors and increased tumor latency regardless of telomere length. Decreased tumor formation correlated with increased apoptosis in Terc deficient tumors. Short telomeres dramatically increased lung metastasis which correlated with increased genomic instability, and specific alterations in DNA copy number and gene expression. We concluded that short telomeres promote metastasis in the absence of telomerase activity in neu oncogene driven mammary tumors.

  1. 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.

  2. DDX3 enhances oncogenic KRAS-induced tumor invasion in colorectal cancer via the β-catenin/ZEB1 axis

    Science.gov (United States)

    Wu, De-Wei; Lin, Po-Lin; Cheng, Ya-Wen; Huang, Chi-Chou; Wang, Lee; Lee, Huei

    2016-01-01

    DDX3 plays a dual role in colorectal cancer; however, the role and underlying mechanism of DDX3 in colorectal tumorigenesis remains unclear. Here, we provide evidence that DDX3 enhances oncogenic KRAS transcription via an increase in SP1 binding to its promoter. Accelerating oncogenic KRAS expression by DDX3 promotes the invasion capability via the ERK/PTEN/AKT/β-catenin cascade. Moreover, the β-catenin/ZEB1 axis is responsible for DDX3-induced cell invasiveness and xenograft lung tumor nodule formation. The xenograft lung tumor nodules induced by DDX3-overexpressing T84 stable clone were nearly suppressed by the inhibitor of AKT (perifosine) or β-catenin (XAV939). Among patients, high KRAS, positive nuclear β-catenin expression and high ZEB1 were more commonly occurred in high-DDX3 tumors than in low-DDX3 tumors. High-DDX3, high-KRAS, positive nuclear β-catenin tumors, and high-ZEB1 exhibited worse overall survival (OS) and relapse free survival (RFS) than their counterparts. In conclusion, DDX3 may play an oncogenic role to promote tumor growth and invasion in colon cancer cells via the β-catenin/ZEB1 axis due to increasing KRAS transcription. We therefore suggest that AKT or β-catenin may potentially act as a therapeutic target to improve tumor regression and outcomes in colorectal cancer patients who harbored high-DDX3 tumors. PMID:27007150

  3. 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.

  4. E6/E7 oncogenes in epithelial suprabasal layers and estradiol promote cervical growth and ear regeneration.

    Science.gov (United States)

    García, C; Hernández-García, D; Valencia, C; Rojo-León, V; Pérez-Estrada, J-R; Werner, M; Covarrubias, L

    2017-08-28

    Tissue growth is a common characteristic of carcinogenesis and regeneration. Here we show that suprabasal expression of human papillomavirus (HPV)16 E6/E7 oncogenes in Tg(K6b-E6/E7) mice, similar to that observed in HPV-infected human tissue, and estradiol increased cervical epithelium growth and ear-hole closure efficiency. Oncogenes in combination with estradiol had a significant contribution to the proliferation of suprabasal cells of cervical epithelium that correlated with an increased expression of keratin genes. Remarkably, long-term treatments with estradiol resulted in evident cellular and tissue abnormalities indicative of a precancerous phenotype. Regenerating ear epithelium of transgenic mice also showed increased suprabasal cell proliferation and expression of keratin genes. Unexpectedly, we observed higher ear regeneration efficiency in adult than in young female mice, which was further increased by E6/E7 oncogenes. Supporting a role of estradiol in this phenomenon, ovariectomy and treatment with an estrogen receptor inhibitor caused a significant reduction in regenerative capacity. Our data suggest that Tg(K6b-E6/E7) mice are unique to mimic the initial stages of HPV-mediated cervical carcinogenesis, and ear regeneration could facilitate the elucidation of mechanisms involved.

  5. Novel E6 and E7 oncogenes variants of human papillomavirus type 31 in Brazilian women with abnormal cervical cytology.

    Science.gov (United States)

    Chagas, Bárbara Simas; Batista, Marcus Vinicius de Aragão; Crovella, Sergio; Gurgel, Ana Pavla Almeida Diniz; Silva Neto, Jacinto da Costa; Serra, Ivi Gonçalves Soares Santos; Amaral, Carolina Maria Medeiros; Balbino, Valdir Queiroz; Muniz, Maria Tereza Cartaxo; Freitas, Antonio Carlos

    2013-06-01

    HPV-31 has been widely described as an important oncogenic type, showing high incidence in worldwide and especially in Northeastern Brazil. We sought to identify the presence of specific mutations in HPV-31 E6 and E7 oncogenes in women with abnormal cervical smear. We enrolled 150 gynecological patients from Sergipe State, Northeastern Brazil. HPV screening was carried out by polymerase chain reaction (MY09/11). E6 and E7 oncogenes were amplified with specific primers and sequenced. The sequences obtained were aligned with the GenBank reference sequences in order to search for genetic variants. We identified genetic variants in E6 and E7 sequences from HPV-31. Two new nucleotide changes in E6 and E7 were described for the first time in this study. A novel mutation in E6 resulted in amino acid change in a site belonging to T-cell epitope with MHC II binding activity. There was no significant difference in the distribution of HPV-31 E6 and E7 variants when compared to all selected clinical/epidemiological characteristics. HPV-31 isolates have been clustered into three main groups called lineages A, B and C. We describe new HPV-31 variants in Brazil, contributing to better understand the genomic diversity of these viruses. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Leukemia Inhibitory Factor Downregulates Human Papillomavirus-16 Oncogene Expression and Inhibits the Proliferation of Cervical Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Joseph M. Bay

    2011-01-01

    Full Text Available The constitutive proliferation and resistance to differentiation and apoptosis of neoplastic cervical cells depend on sustained expression of human papillomavirus oncogenes. Inhibition of these oncogenes is a goal for the prevention of progression of HPV-induced neoplasias to cervical cancer. SiHa cervical cancer cells were transfected with an HPV-16 promoter reporter construct and treated with leukemia inhibitory factor (LIF, a human cytokine of the interleukin 6 superfamily. SiHa and CaSki cervical cancer cells were also assessed for proliferation by MTT precipitation, programmed cell death by flow cytometry, and HPV E6 and E7 expression by real-time PCR. LIF-treated cervical cancer cells showed significantly reduced HPV LCR activation, reduced levels of E6 and E7 mRNA, and reduced proliferation. We report the novel use of LIF to inhibit viral oncogene expression in cervical cancer cells, with concomitant reduction in proliferation suggesting re-engagement of cell-cycle regulation.

  7. Activation of the LMO2 oncogene through a somatically acquired neomorphic promoter in T-cell acute lymphoblastic leukemia.

    Science.gov (United States)

    Rahman, Sunniyat; Magnussen, Michael; León, Theresa E; Farah, Nadine; Li, Zhaodong; Abraham, Brian J; Alapi, Krisztina Z; Mitchell, Rachel J; Naughton, Tom; Fielding, Adele K; Pizzey, Arnold; Bustraan, Sophia; Allen, Christopher; Popa, Teodora; Pike-Overzet, Karin; Garcia-Perez, Laura; Gale, Rosemary E; Linch, David C; Staal, Frank J T; Young, Richard A; Look, A Thomas; Mansour, Marc R

    2017-03-07

    Somatic mutations within non-coding genomic regions that aberrantly activate oncogenes have remained poorly characterized. Here we describe recurrent activating intronic mutations of LMO2, a prominent oncogene in T-cell acute lymphoblastic leukemia (T-ALL). Heterozygous mutations were identified in PF-382 and DU.528 T-ALL cell lines, in addition to 3.7% (6/160) of pediatric and 5.5% (9/163) of adult T-ALL patient samples. The majority of indels harbour putative de novo MYB, ETS1 or RUNX1 consensus binding sites. Analysis of 5'-capped RNA transcripts in mutant cell lines identified the usage of an intermediate promoter site, with consequential monoallelic LMO2 overexpression. CRISPR/Cas9-mediated disruption of the mutant allele in PF-382 cells markedly downregulated LMO2 expression, establishing clear causality between the mutation and oncogene dysregulation. Furthermore, the spectrum of CRISPR/Cas9-derived mutations provide important insights into the interconnected contributions of functional transcription factor binding. Finally, these mutations occur in the same intron as retroviral integration sites in gene therapy induced T-ALL, suggesting that such events occur at preferential sites in the non-coding genome.

  8. Systems biology modeling reveals a possible mechanism of the tumor cell death upon oncogene inactivation in EGFR addicted cancers.

    Directory of Open Access Journals (Sweden)

    Jian-Ping Zhou

    Full Text Available Despite many evidences supporting the concept of "oncogene addiction" and many hypotheses rationalizing it, there is still a lack of detailed understanding to the precise molecular mechanism underlying oncogene addiction. In this account, we developed a mathematic model of epidermal growth factor receptor (EGFR associated signaling network, which involves EGFR-driving proliferation/pro-survival signaling pathways Ras/extracellular-signal-regulated kinase (ERK and phosphoinositol-3 kinase (PI3K/AKT, and pro-apoptotic signaling pathway apoptosis signal-regulating kinase 1 (ASK1/p38. In the setting of sustained EGFR activation, the simulation results show a persistent high level of proliferation/pro-survival effectors phospho-ERK and phospho-AKT, and a basal level of pro-apoptotic effector phospho-p38. The potential of p38 activation (apoptotic potential due to the elevated level of reactive oxygen species (ROS is largely suppressed by the negative crosstalk between PI3K/AKT and ASK1/p38 pathways. Upon acute EGFR inactivation, the survival signals decay rapidly, followed by a fast increase of the apoptotic signal due to the release of apoptotic potential. Overall, our systems biology modeling together with experimental validations reveals that inhibition of survival signals and concomitant release of apoptotic potential jointly contribute to the tumor cell death following the inhibition of addicted oncogene in EGFR addicted cancers.

  9. Metabolic Rewiring by Oncogenic BRAF V600E Links Ketogenesis Pathway to BRAF-MEK1 Signaling.

    Science.gov (United States)

    Kang, Hee-Bum; Fan, Jun; Lin, Ruiting; Elf, Shannon; Ji, Quanjiang; Zhao, Liang; Jin, Lingtao; Seo, Jae Ho; Shan, Changliang; Arbiser, Jack L; Cohen, Cynthia; Brat, Daniel; Miziorko, Henry M; Kim, Eunhee; Abdel-Wahab, Omar; Merghoub, Taha; Fröhling, Stefan; Scholl, Claudia; Tamayo, Pablo; Barbie, David A; Zhou, Lu; Pollack, Brian P; Fisher, Kevin; Kudchadkar, Ragini R; Lawson, David H; Sica, Gabriel; Rossi, Michael; Lonial, Sagar; Khoury, Hanna J; Khuri, Fadlo R; Lee, Benjamin H; Boggon, Titus J; He, Chuan; Kang, Sumin; Chen, Jing

    2015-08-06

    Many human cancers share similar metabolic alterations, including the Warburg effect. However, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Here we demonstrate a "synthetic lethal" interaction between oncogenic BRAF V600E and a ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL). HMGCL expression is upregulated in BRAF V600E-expressing human primary melanoma and hairy cell leukemia cells. Suppression of HMGCL specifically attenuates proliferation and tumor growth potential of human melanoma cells expressing BRAF V600E. Mechanistically, active BRAF upregulates HMGCL through an octamer transcription factor Oct-1, leading to increased intracellular levels of HMGCL product, acetoacetate, which selectively enhances binding of BRAF V600E but not BRAF wild-type to MEK1 in V600E-positive cancer cells to promote activation of MEK-ERK signaling. These findings reveal a mutation-specific mechanism by which oncogenic BRAF V600E "rewires" metabolic and cell signaling networks and signals through the Oct-1-HMGCL-acetoacetate axis to selectively promote BRAF V600E-dependent tumor development.

  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. 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.

  12. The MYC 3′ Wnt-Responsive Element Drives Oncogenic MYC Expression in Human Colorectal Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sherri A. Rennoll

    2016-05-01

    Full Text Available Mutations in components of the Wnt/β-catenin signaling pathway drive colorectal cancer (CRC by deregulating expression of downstream target genes including the c-MYC proto-oncogene (MYC. The critical regulatory DNA enhancer elements that control oncogenic MYC expression in CRC have yet to be fully elucidated. In previous reports, we correlated T-cell factor (TCF and β-catenin binding to the MYC 3′ Wnt responsive DNA element (MYC 3′ WRE with MYC expression in HCT116 cells. Here we used CRISPR/Cas9 to determine whether this element is a critical driver of MYC. We isolated a clonal population of cells that contained a deletion of a single TCF binding element (TBE within the MYC 3′ WRE. This deletion reduced TCF/β-catenin binding to this regulatory element and decreased MYC expression. Using RNA-Seq analysis, we found altered expression of genes that regulate metabolic processes, many of which are known MYC target genes. We found that 3′ WRE-Mut cells displayed a reduced proliferative capacity, diminished clonogenic growth, and a decreased potential to form tumors in vivo. These findings indicate that the MYC 3′ WRE is a critical driver of oncogenic MYC expression and suggest that this element may serve as a therapeutic target for CRC.

  13. Tumor-Promoting Circuits That Regulate a Cancer-Related Chemokine Cluster: Dominance of Inflammatory Mediators Over Oncogenic Alterations

    Energy Technology Data Exchange (ETDEWEB)

    Leibovich-Rivkin, Tal [Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Buganim, Yosef; Solomon, Hilla [Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100 (Israel); Meshel, Tsipi [Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Rotter, Varda [Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100 (Israel); Ben-Baruch, Adit, E-mail: aditbb@tauex.tau.ac.il [Department of Cell Research and Immunology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel)

    2012-01-20

    Here, we investigated the relative contribution of genetic/signaling components versus microenvironmental factors to the malignancy phenotype. In this system, we took advantage of non-transformed fibroblasts that carried defined oncogenic modifications in Ras and/or p53. These cells were exposed to microenvironmental pressures, and the expression of a cancer-related chemokine cluster was used as readout for the malignancy potential (CCL2, CCL5, CXCL8, CXCL10). In cells kept in-culture, synergism between Ras hyper-activation and p53 dysfunction was required to up-regulate the expression of the chemokine cluster. The in vivo passage of Ras{sup High}/p53{sup Low}-modified cells has led to tumor formation, accompanied by potentiation of chemokine release, implicating a powerful role for the tumor microenvironment in up-regulating the chemokine cluster. Indeed, we found that inflammatory mediators which are prevalent in tumor sites, such as TNFα and IL-1β, had a predominant impact on the release of the chemokines, which was substantially higher than that obtained by the oncogenic modifications alone, possibly acting through the transcription factors AP-1 and NF-κB. Together, our results propose that in the unbiased model system that we were using, inflammatory mediators of the tumor milieu have dominating roles over oncogenic modifications in dictating the expression of a pro-malignancy chemokine readout.

  14. YES oncogenic activity is specified by its SH4 domain and regulates RAS/MAPK signaling in colon carcinoma cells.

    Science.gov (United States)

    Dubois, Fanny; Leroy, Cédric; Simon, Valérie; Benistant, Christine; Roche, Serge

    2015-01-01

    Members of the SRC family of tyrosine kinases (SFK) display important functions in human cancer, but their specific role in tumorigenesis remains unclear. We previously demonstrated that YES regulates a unique oncogenic signaling important for colorectal cancer (CRC) progression that is not shared with SRC. Here, we addressed the underlying mechanism involved in this process. We show that YES oncogenic signaling relies on palmitoylation of its SH4 domain that controls YES localization in cholesterol-enriched membrane micro-domains. Specifically, deletion of the palmitoylation site compromised YES transforming activity, while addition of a palmitoylation site in the SH4 domain of SRC was sufficient for SRC to restore the transforming properties of cells in which YES had been silenced. Subsequently, SILAC phosphoproteomic analysis revealed that micro-domain-associated cell adhesive components and receptor tyrosine kinases are major YES substrates. YES also phosphorylates upstream regulators of RAS/MAPK signaling, including EGFR, SHC and SHP2, which were not targeted by SRC due to the absence of palmitoylation. Accordingly, EGFR-induced MAPK activity was attenuated by YES down-regulation, while increased RAS activity significantly restored cell transformation that was lost upon YES silencing. Collectively, these results uncover a critical role for the SH4 domain in the specification of SFK oncogenic activity and a selective role for YES in the induction of RAS/MAPK signaling in CRC cells.

  15. Chemopreventive activity of plant flavonoid isorhamnetin in colorectal cancer is mediated by oncogenic Src and β-catenin.

    Science.gov (United States)

    Saud, Shakir M; Young, Matthew R; Jones-Hall, Yava L; Ileva, Lilia; Evbuomwan, Moses O; Wise, Jennifer; Colburn, Nancy H; Kim, Young S; Bobe, Gerd

    2013-09-01

    Analysis of the Polyp Prevention Trial showed an association between an isorhamnetin-rich diet and a reduced risk of advanced adenoma recurrence; however, the mechanism behind the chemoprotective effects of isorhamnetin remains unclear. Here, we show that isorhamnetin prevents colorectal tumorigenesis of FVB/N mice treated with the chemical carcinogen azoxymethane and subsequently exposed to colonic irritant dextran sodium sulfate (DSS). Dietary isorhamnetin decreased mortality, tumor number, and tumor burden by 62%, 35%, and 59%, respectively. MRI, histopathology, and immunohistochemical analysis revealed that dietary isorhamnetin resolved the DSS-induced inflammatory response faster than the control diet. Isorhamnetin inhibited AOM/DSS-induced oncogenic c-Src activation and β-catenin nuclear translocation, while promoting the expression of C-terminal Src kinase (CSK), a negative regulator of Src family of tyrosine kinases. Similarly, in HT-29 colon cancer cells, isorhamnetin inhibited oncogenic Src activity and β-catenin nuclear translocation by inducing expression of csk, as verified by RNA interference knockdown of csk. Our observations suggest the chemoprotective effects of isorhamnetin in colon cancer are linked to its anti-inflammatory activities and its inhibition of oncogenic Src activity and consequential loss of nuclear β-catenin, activities that are dependent on CSK expression.

  16. Identification of a pan-cancer oncogenic microRNA superfamily anchored by a central core seed motif

    Science.gov (United States)

    Hamilton, Mark P.; Rajapakshe, Kimal; Hartig, Sean M.; Reva, Boris; McLellan, Michael D.; Kandoth, Cyriac; Ding, Li; Zack, Travis I.; Gunaratne, Preethi H.; Wheeler, David A.; Coarfa, Cristian; McGuire, Sean E.

    2013-11-01

    MicroRNAs modulate tumorigenesis through suppression of specific genes. As many tumour types rely on overlapping oncogenic pathways, a core set of microRNAs may exist, which consistently drives or suppresses tumorigenesis in many cancer types. Here we integrate The Cancer Genome Atlas (TCGA) pan-cancer data set with a microRNA target atlas composed of publicly available Argonaute Crosslinking Immunoprecipitation (AGO-CLIP) data to identify pan-tumour microRNA drivers of cancer. Through this analysis, we show a pan-cancer, coregulated oncogenic microRNA ‘superfamily’ consisting of the miR-17, miR-19, miR-130, miR-93, miR-18, miR-455 and miR-210 seed families, which cotargets critical tumour suppressors via a central GUGC core motif. We subsequently define mutations in microRNA target sites using the AGO-CLIP microRNA target atlas and TCGA exome-sequencing data. These combined analyses identify pan-cancer oncogenic cotargeting of the phosphoinositide 3-kinase, TGFβ and p53 pathways by the miR-17-19-130 superfamily members.

  17. Transformation with Oncogenic Ras and the Simian Virus 40 T Antigens Induces Caspase-Dependent Sensitivity to Fatty Acid Biosynthetic Inhibition

    Science.gov (United States)

    Xu, Shihao; Spencer, Cody M.

    2015-01-01

    ABSTRACT Oncogenesis is frequently accompanied by the activation of specific metabolic pathways. One such pathway is fatty acid biosynthesis, whose induction is observed upon transformation of a wide variety of cell types. Here, we explored how defined oncogenic alleles, specifically the simian virus 40 (SV40) T antigens and oncogenic Ras12V, affect fatty acid metabolism. Our results indicate that SV40/Ras12V-mediated transformation of fibroblasts induces fatty acid biosynthesis in the absence of significant changes in the concentration of fatty acid biosynthetic enzymes. This oncogene-induced activation of fatty acid biosynthesis was found to be mammalian target of rapamycin (mTOR) dependent, as it was attenuated by rapamycin treatment. Furthermore, SV40/Ras12V-mediated transformation induced sensitivity to treatment with fatty acid biosynthetic inhibitors. Pharmaceutical inhibition of acetyl-coenzyme A (CoA) carboxylase (ACC), a key fatty acid biosynthetic enzyme, induced caspase-dependent cell death in oncogene-transduced cells. In contrast, isogenic nontransformed cells were resistant to fatty acid biosynthetic inhibition. This oncogene-induced sensitivity to fatty acid biosynthetic inhibition was independent of the cells' growth rates and could be attenuated by supplementing the medium with unsaturated fatty acids. Both the activation of fatty acid biosynthesis and the sensitivity to fatty acid biosynthetic inhibition could be conveyed to nontransformed breast epithelial cells through transduction with oncogenic Ras12V. Similar to what was observed in the transformed fibroblasts, the Ras12V-induced sensitivity to fatty acid biosynthetic inhibition was independent of the proliferative status and could be attenuated by supplementing the medium with unsaturated fatty acids. Combined, our results indicate that specific oncogenic alleles can directly confer sensitivity to inhibitors of fatty acid biosynthesis. IMPORTANCE Viral oncoproteins and cellular mutations

  18. Driving gradual endogenous c-myc overexpression by flow-sorting: intracellular signaling and tumor cell phenotype correlate with oncogene expression

    DEFF Research Database (Denmark)

    Knudsen, Kasper Jermiin; Holm, G.M.N.; Krabbe, J.S.

    2009-01-01

    cells than in the nonsorted cell population. To our knowledge, this is the first in vitro system allowing functional coupling between mitogenic signaling by a well-defined growth factor and gradual overexpression of the normal, endogenous c-myc gene. Thus, our flow-sorting approach provides...... an alternative modeling of the receptor-mediated carcinogenic process, compared to the currently used approaches of recombinant constitutive or conditional overexpression of oncogenic transmembrane receptor tyrosine kinases or oncogenic transcription factors....

  19. Transformation of chicken embryo fibroblasts by direct DNA transfection of single oncogenes: comparative analyses of src, erbB, myc, and ras.

    OpenAIRE

    Antczak, M; Kung, H J

    1990-01-01

    Chicken embryo fibroblasts (CEF) have been used extensively to study the transformation parameters of a number of avian sarcoma-leukemia viruses. Previously, oncogene transformation of CEF has been conducted almost exclusively with replicating viruses, because of perceived difficulties with direct DNA transfection. Here, we show that CEF can be efficiently and stably transfected by selection for the neomycin resistance gene (neo). Cotransfection of neo with various oncogenes resulted in CEF t...

  20. α-Lipoic Acid Inhibits Helicobacter pylori-Induced Oncogene Expression and Hyperproliferation by Suppressing the Activation of NADPH Oxidase in Gastric Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Eunyoung Byun

    2014-01-01

    Full Text Available Hyperproliferation and oncogene expression are observed in the mucosa of Helicobacter pylori- (H. pylori- infected patients with gastritis or adenocarcinoma. Expression of oncogenes such as β-catenin and c-myc is related to oxidative stress. α-Lipoic acid (α-LA, a naturally occurring thiol compound, acts as an antioxidant and has an anticancer effect. The aim of this study is to investigate the effect of α-LA on H. pylori-induced hyperproliferation and oncogene expression in gastric epithelial AGS cells by determining cell proliferation (viable cell numbers, thymidine incorporation, levels of reactive oxygen species (ROS, NADPH oxidase activation (enzyme activity, subcellular levels of NADPH oxidase subunits, activation of redox-sensitive transcription factors (NF-κB, AP-1, expression of oncogenes (β-catenin, c-myc, and nuclear localization of β-catenin. Furthermore, we examined whether NADPH oxidase mediates oncogene expression and hyperproliferation in H. pylori-infected AGS cells using treatment of diphenyleneiodonium (DPI, an inhibitor of NADPH oxidase. As a result, α-LA inhibited the activation of NADPH oxidase and, thus, reduced ROS production, resulting in inhibition on activation of NF-κB and AP-1, induction of oncogenes, nuclear translocation of β-catenin, and hyperproliferation in H. pylori-infected AGS cells. DPI inhibited H. pylori-induced activation of NF-κB and AP-1, oncogene expression and hyperproliferation by reducing ROS levels in AGS cells. In conclusion, we propose that inhibiting NADPH oxidase by α-LA could prevent oncogene expression and hyperproliferation occurring in H. pylori-infected gastric epithelial cells.

  1. Oncogenic K-Ras Signals through Epidermal Growth Factor Receptor and Wild-Type H-Ras to Promote Radiation Survival in Pancreatic and Colorectal Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Keith A. Cengel

    2007-04-01

    Full Text Available Pancreatic and colorectal carcinomas frequently express oncogenic/mutant K-Ras that contributes to both tumorigenesis and clinically observed resistance to radiation treatment. We have previously shown that farnesyltransferase inhibitors (FTI radiosensitize many pancreatic and colorectal cancer cell lines that express oncogenic K-ras at doses that inhibit the prenylation and activation of H-Ras but not K-Ras. In the present study, we have examined the mechanism of FTI-mediated radiosensitization in cell lines that express oncogenic K-Ras and found that wild-type H-Ras is a contributor to radiation survival in tumor cells that express oncogenic K-Ras. In these experiments, inhibiting the expression of oncogenic K-Ras, wild-type H-Ras, or epidermal growth factor receptor (EGFR led to similar levels of radiosensitization as treatment with the FTI tipifarnib. Treatment with the EGFR inhibitor gefitinib led to similar levels of radiosensitization, and the combinations of tipifarnib or gefitinib plus inhibition of K-Ras, H-Ras, or EGFR expression did not provide additional radiosensitization compared with tipifarnib or gefitinib alone. Finally, supplementing culture medium with the EGFR ligand transforming growth factor o was able to reverse the radiosensitizing effect of inhibiting K-ras expression. Taken together, these findings suggest that EGFRactivated H-Ras signaling is initiated by oncogenic K-Ras to promote radiation survival in pancreatic and colorectal cancers.

  2. Oncogenic K-Ras Signals through Epidermal Growth Factor Receptor and Wild-Type H-Ras to Promote Radiation Survival in Pancreatic and Colorectal Carcinoma Cells1

    Science.gov (United States)

    Cengel, Keith A.; Voong, K. Rahn; Chandrasekaran, Sanjay; Maggiorella, Laurence; Brunner, Thomas B.; Stanbridge, Eric; Kao, Gary D.; McKenna, W. Gillies; Bernhard, Eric J.

    2007-01-01

    Pancreatic and colorectal carcinomas frequently express oncogenic/mutant K-Ras that contributes to both tumorigenesis and clinically observed resistance to radiation treatment. We have previously shown that farnesyltransferase inhibitors (FTI) radiosensitize many pancreatic and colorectal cancer cell lines that express oncogenic K-ras at doses that inhibit the prenylation and activation of H-Ras but not K-Ras. In the present study, we have examined the mechanism of FTI-mediated radiosensitization in cell lines that express oncogenic K-Ras and found that wild-type H-Ras is a contributor to radiation survival in tumor cells that express oncogenic K-Ras. In these experiments, inhibiting the expression of oncogenic K-Ras, wild-type H-Ras, or epidermal growth factor receptor (EGFR) led to similar levels of radiosensitization as treatment with the FTI tipifarnib. Treatment with the EGFR inhibitor gefitinib led to similar levels of radiosensitization, and the combinations of tipifarnib or gefitinib plus inhibition of K-Ras, H-Ras, or EGFR expression did not provide additional radiosensitization compared with tipifarnib or gefitinib alone. Finally, supplementing culture medium with the EGFR ligand transforming growth factor α was able to reverse the radiosensitizing effect of inhibiting K-ras expression. Taken together, these findings suggest that EGFR-activated H-Ras signaling is initiated by oncogenic K-Ras to promote radiation survival in pancreatic and colorectal cancers. PMID:17460778

  3. Oncogenic K-Ras signals through epidermal growth factor receptor and wild-type H-Ras to promote radiation survival in pancreatic and colorectal carcinoma cells.

    Science.gov (United States)

    Cengel, Keith A; Voong, K Rahn; Chandrasekaran, Sanjay; Maggiorella, Laurence; Brunner, Thomas B; Stanbridge, Eric; Kao, Gary D; McKenna, W Gillies; Bernhard, Eric J

    2007-04-01

    Pancreatic and colorectal carcinomas frequently express oncogenic/mutant K-Ras that contributes to both tumorigenesis and clinically observed resistance to radiation treatment. We have previously shown that farnesyltransferase inhibitors (FTI) radiosensitize many pancreatic and colorectal cancer cell lines that express oncogenic K-ras at doses that inhibit the prenylation and activation of H-Ras but not K-Ras. In the present study, we have examined the mechanism of FTI-mediated radiosensitization in cell lines that express oncogenic K-Ras and found that wild-type H-Ras is a contributor to radiation survival in tumor cells that express oncogenic K-Ras. In these experiments, inhibiting the expression of oncogenic K-Ras, wild-type H-Ras, or epidermal growth factor receptor (EGFR) led to similar levels of radiosensitization as treatment with the FTI tipifarnib. Treatment with the EGFR inhibitor gefitinib led to similar levels of radiosensitization, and the combinations of tipifarnib or gefitinib plus inhibition of K-Ras, H-Ras, or EGFR expression did not provide additional radiosensitization compared with tipifarnib or gefitinib alone. Finally, supplementing culture medium with the EGFR ligand transforming growth factor alpha was able to reverse the radiosensitizing effect of inhibiting K-ras expression. Taken together, these findings suggest that EGFR-activated H-Ras signaling is initiated by oncogenic K-Ras to promote radiation survival in pancreatic and colorectal cancers.

  4. Characterization of Leukemia-Inducing Genes Using a Proto-Oncogene/Homeobox Gene Retroviral Human cDNA Library in a Mouse In Vivo Model.

    Directory of Open Access Journals (Sweden)

    Su Hwa Jang

    Full Text Available The purpose of this research is to develop a method to screen a large number of potential driver mutations of acute myeloid leukemia (AML using a retroviral cDNA library and murine bone marrow transduction-transplantation system. As a proof-of-concept, murine bone marrow (BM cells were transduced with a retroviral cDNA library encoding well-characterized oncogenes and homeobox genes, and the virus-transduced cells were transplanted into lethally irradiated mice. The proto-oncogenes responsible for leukemia initiation were identified by PCR amplification of cDNA inserts from genomic DNA isolated from leukemic cells. In an initial screen of ten leukemic mice, the MYC proto-oncogene was detected in all the leukemic mice. Of ten leukemic mice, 3 (30% had MYC as the only transgene, and seven mice (70% had additional proto-oncogene inserts. We repeated the same experiment after removing MYC-related genes from the library to characterize additional leukemia-inducing gene combinations. Our second screen using the MYC-deleted proto-oncogene library confirmed MEIS1and the HOX family as cooperating oncogenes in leukemia pathogenesis. The model system we introduced in this study will be valuable in functionally screening novel combinations of genes for leukemogenic potential in vivo, and the system will help in the discovery of new targets for leukemia therapy.

  5. Characterization of Leukemia-Inducing Genes Using a Proto-Oncogene/Homeobox Gene Retroviral Human cDNA Library in a Mouse In Vivo Model.

    Science.gov (United States)

    Jang, Su Hwa; Lee, Sohyun; Chung, Hee Yong

    2015-01-01

    The purpose of this research is to develop a method to screen a large number of potential driver mutations of acute myeloid leukemia (AML) using a retroviral cDNA library and murine bone marrow transduction-transplantation system. As a proof-of-concept, murine bone marrow (BM) cells were transduced with a retroviral cDNA library encoding well-characterized oncogenes and homeobox genes, and the virus-transduced cells were transplanted into lethally irradiated mice. The proto-oncogenes responsible for leukemia initiation were identified by PCR amplification of cDNA inserts from genomic DNA isolated from leukemic cells. In an initial screen of ten leukemic mice, the MYC proto-oncogene was detected in all the leukemic mice. Of ten leukemic mice, 3 (30%) had MYC as the only transgene, and seven mice (70%) had additional proto-oncogene inserts. We repeated the same experiment after removing MYC-related genes from the library to characterize additional leukemia-inducing gene combinations. Our second screen using the MYC-deleted proto-oncogene library confirmed MEIS1and the HOX family as cooperating oncogenes in leukemia pathogenesis. The model system we introduced in this study will be valuable in functionally screening novel combinations of genes for leukemogenic potential in vivo, and the system will help in the discovery of new targets for leukemia therapy.

  6. Long-range oncogenic activation of Igh-c-myc translocations by the Igh 3' regulatory region.

    Science.gov (United States)

    Gostissa, Monica; Yan, Catherine T; Bianco, Julia M; Cogné, Michel; Pinaud, Eric; Alt, Frederick W

    2009-12-10

    B-cell malignancies, such as human Burkitt's lymphoma, often contain translocations that link c-myc or other proto-oncogenes to the immunoglobulin heavy chain locus (IgH, encoded by Igh). The nature of elements that activate oncogenes within such translocations has been a long-standing question. Translocations within Igh involve DNA double-strand breaks initiated either by the RAG1/2 endonuclease during variable, diversity and joining gene segment (V(D)J) recombination, or by activation-induced cytidine deaminase (AID, also known as AICDA) during class switch recombination (CSR). V(D)J recombination in progenitor B (pro-B) cells assembles Igh variable region exons upstream of mu constant region (Cmu) exons, which are the first of several sets of C(H) exons ('C(H) genes') within a C(H) locus that span several hundred kilobases (kb). In mature B cells, CSR deletes Cmu and replaces it with a downstream C(H) gene. An intronic enhancer (iEmu) between the variable region exons and Cmu promotes V(D)J recombination in developing B cells. Furthermore, the Igh 3' regulatory region (Igh3'RR) lies downstream of the C(H) locus and modulates CSR by long-range transcriptional enhancement of C(H) genes. Transgenic mice bearing iEmu or Igh3'RR sequences fused to c-myc are predisposed to B lymphomas, demonstrating that such elements can confer oncogenic c-myc expression. However, in many B-cell lymphomas, Igh-c-myc translocations delete iEmu and place c-myc up to 200 kb upstream of the Igh3'RR. Here we address the oncogenic role of the Igh3'RR by inactivating it in two distinct mouse models for B-cell lymphoma with Igh-c-myc translocations. We show that the Igh3'RR is dispensable for pro-B-cell lymphomas with V(D)J recombination-initiated translocations, but is required for peripheral B-cell lymphomas with CSR-associated translocations. As the Igh3'RR is not required for CSR-associated Igh breaks or Igh-c-myc translocations in peripheral B-cell lymphoma progenitors, we conclude that

  7. 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.

  8. Microarray screening for target genes of the proto-oncogene PLAG1.

    Science.gov (United States)

    Voz, Marianne L; Mathys, Janick; Hensen, Karen; Pendeville, Hélène; Van Valckenborgh, Isabelle; Van Huffel, Christophe; Chavez, Marcela; Van Damme, Boudewijn; De Moor, Bart; Moreau, Yves; Van de Ven, Wim J M

    2004-01-08

    PLAG1 is a proto-oncogene whose ectopic expression can trigger the development of pleomorphic adenomas of the salivary glands and of lipoblastomas. As PLAG1 is a transcription factor, able to activate transcription through the binding to the consensus sequence GRGGC(N)(6-8)GGG, its ectopic expression presumably results in the deregulation of target genes, leading to uncontrolled cell proliferation. The identification of PLAG1 target genes is therefore a crucial step in understanding the molecular mechanisms involved in PLAG1-induced tumorigenesis. To this end, we analysed the changes in gene expression caused by the conditional induction of PLAG1 expression in fetal kidney 293 cell lines. Using oligonucleotide microarray analyses of about 12 000 genes, we consistently identified 47 genes induced and 12 genes repressed by PLAG1. One of the largest classes identified as upregulated PLAG1 targets consists of growth factors such as the insulin-like growth factor II and the cytokine-like factor 1. The in silico search for PLAG1 consensus sequences in the promoter of the upregulated genes reveals that a large proportion of them harbor several copies of the PLAG1-binding motif, suggesting that they represent direct PLAG1 targets. Our approach was complemented by the comparison of the expression profiles of pleomorphic adenomas induced by PLAG1 versus normal salivary glands. Concordance between these two sets of experiments pinpointed 12 genes that were significantly and consistently upregulated in pleomorphic adenomas and in PLAG1-expressing cells, identifying them as putative PLAG1 targets in these tumors.

  9. Oncogenic Nras has bimodal effects on stem cells that sustainably increase competitiveness.

    Science.gov (United States)

    Li, Qing; Bohin, Natacha; Wen, Tiffany; Ng, Victor; Magee, Jeffrey; Chen, Shann-Ching; Shannon, Kevin; Morrison, Sean J

    2013-12-05

    'Pre-leukaemic' mutations are thought to promote clonal expansion of haematopoietic stem cells (HSCs) by increasing self-renewal and competitiveness; however, mutations that increase HSC proliferation tend to reduce competitiveness and self-renewal potential, raising the question of how a mutant HSC can sustainably outcompete wild-type HSCs. Activating mutations in NRAS are prevalent in human myeloproliferative neoplasms and leukaemia. Here we show that a single allele of oncogenic Nras(G12D) increases HSC proliferation but also increases reconstituting and self-renewal potential upon serial transplantation in irradiated mice, all prior to leukaemia initiation. Nras(G12D) also confers long-term self-renewal potential to multipotent progenitors. To explore the mechanism by which Nras(G12D) promotes HSC proliferation and self-renewal, we assessed cell-cycle kinetics using H2B-GFP label retention and 5-bromodeoxyuridine (BrdU) incorporation. Nras(G12D) had a bimodal effect on HSCs, increasing the frequency with which some HSCs divide and reducing the frequency with which others divide. This mirrored bimodal effects on reconstituting potential, as rarely dividing Nras(G12D) HSCs outcompeted wild-type HSCs, whereas frequently dividing Nras(G12D) HSCs did not. Nras(G12D) caused these effects by promoting STAT5 signalling, inducing different transcriptional responses in different subsets of HSCs. One signal can therefore increase HSC proliferation, competitiveness and self-renewal through bimodal effects on HSC gene expression, cycling and reconstituting potential.

  10. Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Murat, C.B.; Braga, P.B.S.; Fortes, M.A.H.Z. [Laboratório de Endocrinologia Celular e Molecular (LIM-25), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Bronstein, M.D. [Unidade de Neuroendocrinologia, Serviço de Endocrinologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Corrêa-Giannella, M.L.C.; Giorgi, R.R. [Laboratório de Endocrinologia Celular e Molecular (LIM-25), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2012-07-13

    The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-α catalytic subunit of PI3K, have been reported in various types of human cancers regarding the role of the gene in cell proliferation and survival through activation of the PI3K/Akt signaling pathway. Only one Chinese study described somatic mutations and amplification of the PIK3CA gene in a large series of pituitary adenomas. The aim of the present study was to determine genetic alterations of PIK3CA in a second series that consisted of 33 pituitary adenomas of different subtypes diagnosed by immunohistochemistry: 6 adrenocorticotropic hormone-secreting microadenomas, 5 growth hormone-secreting macroadenomas, 7 prolactin-secreting macroadenomas, and 15 nonfunctioning macroadenomas. Direct sequencing of exons 9 and 20 assessed by qPCR was employed to investigate the presence of mutations and genomic amplification defined as a copy number ≥4. Previously identified PIK3CA mutations (exon 20) were detected in four cases (12.1%). Interestingly, the Chinese study reported mutations only in invasive tumors, while we found a PIK3CA mutation in one noninvasive corticotroph microadenoma. PIK3CA amplification was observed in 21.2% (7/33) of the cases. This study demonstrates the presence of somatic mutations and amplifications of the PIK3CA gene in a second series of pituitary adenomas, corroborating the previously described involvement of the PI3K/Akt signaling pathway in the tumorigenic process of this gland.

  11. Oncogenic Properties of Apoptotic Tumor Cells in Aggressive B Cell Lymphoma

    Science.gov (United States)

    Ford, Catriona A.; Petrova, Sofia; Pound, John D.; Voss, Jorine J.L.P.; Melville, Lynsey; Paterson, Margaret; Farnworth, Sarah L.; Gallimore, Awen M.; Cuff, Simone; Wheadon, Helen; Dobbin, Edwina; Ogden, Carol Anne; Dumitriu, Ingrid E.; Dunbar, Donald R.; Murray, Paul G.; Ruckerl, Dominik; Allen, Judith E.; Hume, David A.; van Rooijen, Nico; Goodlad, John R.; Freeman, Tom C.; Gregory, Christopher D.

    2015-01-01

    Summary Background Cells undergoing apoptosis are known to modulate their tissue microenvironments. By acting on phagocytes, notably macrophages, apoptotic cells inhibit immunological and inflammatory responses and promote trophic signaling pathways. Paradoxically, because of their potential to cause death of tumor cells and thereby militate against malignant disease progression, both apoptosis and tumor-associated macrophages (TAMs) are often associated with poor prognosis in cancer. We hypothesized that, in progression of malignant disease, constitutive loss of a fraction of the tumor cell population through apoptosis could yield tumor-promoting effects. Results Here, we demonstrate that apoptotic tumor cells promote coordinated tumor growth, angiogenesis, and accumulation of TAMs in aggressive B cell lymphomas. Through unbiased “in situ transcriptomics” analysis—gene expression profiling of laser-captured TAMs to establish their activation signature in situ—we show that these cells are activated to signal via multiple tumor-promoting reparatory, trophic, angiogenic, tissue remodeling, and anti-inflammatory pathways. Our results also suggest that apoptotic lymphoma cells help drive this signature. Furthermore, we demonstrate that, upon induction of apoptosis, lymphoma cells not only activate expression of the tumor-promoting matrix metalloproteinases MMP2 and MMP12 in macrophages but also express and process these MMPs directly. Finally, using a model of malignant melanoma, we show that the