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Sample records for mouse glioma-associated oncogene

  1. Glioma-Associated Oncogene Homolog1 (Gli1)-Aquaporin1 pathway promotes glioma cell metastasis

    PubMed Central

    Liao, Zheng-qiang; Ye, Ming; Yu, Pei-gen; Xiao, Chun; Lin, Feng-yun

    2016-01-01

    Glioma-Associated Oncogene Homolog1 (Gli1) is known to be activated in malignant glioma; however, its downstream pathway has not been fully explained. The aim of this study was to explore the role of Gli1-Aquaporin1 (AQP1) signal pathway in glioma cell survival. Our data suggests that both Gli1 and AQP1 are upregulated in glioma tissues, as in comparison to in normal tissues. These up-regulation phenomena were also observed in glioma U251 and U87 cells. It was demonstrated that Gli1 positively regulated the AQP1 expression. By luciferase reporter gene and ChIP assay, we observed that this modulation process was realized by combination of Gli1 with AQP1 promotor. In addition, knock down of Gli1 by siRNA interference reduced the viability of glioma cells as well as suppressed cell metastasis. Also, the inhibitory effects of cell survival by silenced Gli1 were abrogated by AQP1 overexpression. In summary, glioma cell survival is a regulatory process and can be mediated by Gli1-AQP1 pathway. [BMB Reports 2016; 49(7): 394-399] PMID:27157540

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

    PubMed

    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.

  3. Forkhead Box M1 Is Essential for Nuclear Localization of Glioma-associated Oncogene Homolog 1 in Glioblastoma Multiforme Cells by Promoting Importin-7 Expression*

    PubMed Central

    Xue, Jianfei; Zhou, Aidong; Tan, Christina; Wu, Yamei; Lee, Hsueh-Te; Li, Wenliang; Xie, Keping; Huang, Suyun

    2015-01-01

    The transcription factors glioma-associated oncogene homolog 1 (GLI1), a primary marker of Hedgehog pathway activation, and Forkhead box M1 (FOXM1) are aberrantly activated in a wide range of malignancies, including glioma. However, the mechanism of nuclear localization of GLI1 and whether FOXM1 regulates the Hedgehog signaling pathway are poorly understood. Here we found that FOXM1 promotes nuclear import of GLI1 in glioblastoma multiforme cells and thus increases the expression of its target genes. Conversely, knockdown of FOXM1 expression with FOXM1 siRNA abrogated its nuclear import and inhibited the expression of its target genes. Also, genetic deletion of FOXM1 in mouse embryonic fibroblasts abolished nuclear localization of GLI1. We observed that FOXM1 directly binds to the importin-7 (IPO7) promoter and increases its promoter activity. IPO7 interacted with GLI1, leading to enhanced nuclear import of GLI1. Depletion of IPO7 by IPO7 siRNA reduced nuclear accumulation of GLI1. In addition, FOXM1 induced nuclear import of GLI1 by promoting IPO7 expression. Moreover, the FOXM1/IPO7/GLI1 axis promoted cell proliferation, migration, and invasion in vitro. Finally, expression of FOXM1 was markedly correlated with that of GLI1 in human glioblastoma specimens. These data suggest that FOXM1 and GLI1 form a positive feedback loop that contributes to glioblastoma development. Furthermore, our study revealed a mechanism that controls nuclear import of GLI1 in glioblastoma multiforme cells. PMID:26085085

  4. Glioma-associated Oncogene 2 Is Essential for Trophoblastic Fusion by Forming a Transcriptional Complex with Glial Cell Missing-a.

    PubMed

    Tang, Chao; Tang, Lanfang; Wu, Xiaokai; Xiong, Wenyi; Ruan, Hongfeng; Hussain, Musaddique; Wu, Junsong; Zou, Chaochun; Wu, Ximei

    2016-03-11

    Cell-cell fusion of human villous trophoblasts, referred to as a process of syncytialization, acts as a prerequisite for the proper development and functional maintenance of the human placenta. Given the fact that the main components of the Hedgehog signaling pathway are expressed predominantly in the syncytial layer of human placental villi, in this study, we investigated the potential roles and underlying mechanisms of Hedgehog signaling in trophoblastic fusion. Activation of Hedgehog signaling by a variety of approaches robustly induced cell fusion and the expression of syncytial markers, whereas suppression of Hedgehog signaling significantly attenuated cell fusion and the expression of syncytial markers in both human primary cytotrophoblasts and trophoblast-like BeWo cells. Moreover, among glioma-associated oncogene (GLI) family transcriptional factors in Hedgehog signaling, knockdown of GLI2 but not GLI1 and GLI3 significantly attenuated Hedgehog-induced cell fusion, whereas overexpression of the GLI2 activator alone was sufficient to induce cell fusion. Finally, GLI2 not only stabilized glial cell missing-a, a pivotal transcriptional factor for trophoblastic syncytialization, but also formed a transcriptional heterodimer with glial cell missing-a to transactivate syncytin-1, a trophoblastic fusogen, and promote trophoblastic syncytialization. Taken together, this study uncovered a so far uncharacterized role of Hedgehog/GLI2 signaling in trophoblastic fusion, implicating that Hedgehog signaling, through GLI2, could be required for human placental development and pregnancy maintenance.

  5. Hedgehog-glioma-associated oncogene homolog-1 signaling in colon cancer cells and its role in the celecoxib-mediated anti-cancer effect.

    PubMed

    Wang, Hongtao; Ke, Fei; Zheng, Jie

    2014-11-01

    Hedgehog (Hh) signaling is activated in numerous malignant tumors, but its role in human colorectal cancer remains uncertain. Celecoxib, a selective cyclooxygenase-2 inhibitor, has been shown to exhibit chemoprevention in colorectal cancer, however, the effects of celecoxib on Hh signaling remain unknown. The current study presents an evaluation of Hh signaling in colon cancer cell lines and the effects of celecoxib in vitro. Active Hh signaling was observed in LoVo and HT-29 cells, with particularly high levels in the LoVo cells. However, Hh signaling activity was absent in HCT-116 cells. Quantitative polymerase chain reaction indicated that the expression of Hh receptor patched homolog 1 (PTCH1) was absent in the LoVo cells, but that they exhibited high levels of glioma-associated oncogene homolog-1 (GLI1) expression, while high expression levels of PTCH1 and low expression levels of smoothened (SMO) and GLI1 were observed in the HCT-116 cells. The HCT-116 cells were extremely sensitive to celecoxib, whereas the LoVo cells were resistant to the anticancer effect of the drug. Celecoxib downregulated the expression of GLI1 in the HCT-116 and HT-29 cells, but did not change the expression of GLI1 in the LoVo cells. The results presented in this study indicated that the anticancer effect of celecoxib is selective in colon cancer cells; celecoxib may target cancer cells via the SMO-independent modulation of GLI1 activity, and Hh signaling may be significant in maintaining the malignant state of LoVo cells. These findings may aid in improving our understanding of the carcinogenesis of colon cancer and the development of novel approaches for the targeted therapy of this disease. PMID:25295109

  6. Oncogenes

    SciTech Connect

    Compans, R.W.; Cooper, M.; Koprowski, H.; McConell, I.; Melchers, F.; Nussenzweig, V.; Oldstone, M.; Olsnes, S.; Saedler, H.; Vogt, P.K.

    1989-01-01

    This book covers the following topics: Roles of drosophila proto-oncogenes and growth factor homologs during development of the fly; Interaction of oncogenes with differentiation programs; Genetics of src: structure and functional organization of a protein tyrosine kinase; Structures and activities of activated abl oncogenes; Eukaryotic RAS proteins and yeast proteins with which they interact. This book presents up-to-data review articles on oncogenes. The editor includes five contributions which critically evaluate recent research in the field.

  7. Oncogenic Radiation Abscopal Effects In Vivo: Interrogating Mouse Skin

    SciTech Connect

    Mancuso, Mariateresa; Leonardi, Simona; Giardullo, Paola; Pasquali, Emanuela; Tanori, Mirella; De Stefano, Ilaria; Casciati, Arianna; Naus, Christian C.; Pazzaglia, Simonetta; Saran, Anna

    2013-08-01

    Purpose: To investigate the tissue dependence in transmission of abscopal radiation signals and their oncogenic consequences in a radiosensitive mouse model and to explore the involvement of gap junction intercellular communication (GJIC) in mediating radiation tumorigenesis in off-target mouse skin. Methods and Materials: Patched1 heterozygous (Ptch1{sup +/−}) mice were irradiated at postnatal day 2 (P2) with 10 Gy of x-rays. Individual lead cylinders were used to protect the anterior two-thirds of the body, whereas the hindmost part was directly exposed to radiation. To test the role of GJICs and their major constituent connexin43 (Cx43), crosses between Ptch1{sup +/−} and Cx43{sup +/−} mice were similarly irradiated. These mouse groups were monitored for their lifetime, and skin basal cell carcinomas (BCCs) were counted and recorded. Early responses to DNA damage - Double Strand Breaks (DSBs) and apoptosis - were also evaluated in shielded and directly irradiated skin areas. Results: We report abscopal tumor induction in the shielded skin of Ptch1{sup +/−} mice after partial-body irradiation. Endpoints were induction of early nodular BCC-like tumors and macroscopic infiltrative BCCs. Abscopal tumorigenesis was significantly modulated by Cx43 status, namely, Cx43 reduction was associated with decreased levels of DNA damage and oncogenesis in out-of-field skin, suggesting a key role of GJIC in transmission of oncogenic radiation signals to unhit skin. Conclusions: Our results further characterize the nature of abscopal responses and the implications they have on pathologic processes in different tissues, including their possible underlying mechanistic bases.

  8. A mouse model of melanoma driven by oncogenic KRAS

    PubMed Central

    Milagre, Carla; Dhomen, Nathalie; Geyer, Felipe C; Hayward, Robert; Lambros, Maryou; Reis-Filho, Jorge S; Marais, Richard

    2010-01-01

    The small G-protein NRAS is mutated in 22% of human melanomas, whereas the related proteins, KRAS and HRAS are mutated in only 2% and 1% of melanomas respectively. We have developed a mouse models of melanoma in which Cre recombinase/loxP technology is used to drive inducible expression of G12VKRAS in the melanocytic lineage. The mice develop skin hyper-pigmentation, nevi and tumors that bear many of the cardinal histopathology features and molecular characteristics of human melanoma. These tumors invade and destroy the underlying muscles and cells derived from them can grow as subcutaneous tumors and colonise the lungs of nude mice. These data establish that oncogenic KRAS can be a founder event in melanomagenesis. PMID:20516123

  9. BIM mediates oncogene inactivation-induced apoptosis in multiple transgenic mouse models of acute lymphoblastic leukemia

    PubMed Central

    Li, Yulin; Deutzmann, Anja; Choi, Peter S.; Fan, Alice C.; Felsher, Dean W.

    2016-01-01

    Oncogene inactivation in both clinical targeted therapies and conditional transgenic mouse cancer models can induce significant tumor regression associated with the robust induction of apoptosis. Here we report that in MYC-, RAS-, and BCR-ABL-induced acute lymphoblastic leukemia (ALL), apoptosis upon oncogene inactivation is mediated by the same pro-apoptotic protein, BIM. The induction of BIMin the MYC- and RAS-driven leukemia is mediated by the downregulation of miR-17-92. Overexpression of miR-17-92 blocked the induction of apoptosis upon oncogene inactivation in the MYC and RAS-driven but not in the BCR-ABL-driven ALL leukemia. Hence, our results provide novel insight into the mechanism of apoptosis upon oncogene inactivation and suggest that induction of BIM-mediated apoptosis may be an important therapeutic approach for ALL. PMID:27095570

  10. Generation of transgenic mouse model using PTTG as an oncogene.

    PubMed

    Kakar, Sham S; Kakar, Cohin

    2015-01-01

    The close physiological similarity between the mouse and human has provided tools to understanding the biological function of particular genes in vivo by introduction or deletion of a gene of interest. Using a mouse as a model has provided a wealth of resources, knowledge, and technology, helping scientists to understand the biological functions, translocation, trafficking, and interaction of a candidate gene with other intracellular molecules, transcriptional regulation, posttranslational modification, and discovery of novel signaling pathways for a particular gene. Most importantly, the generation of the mouse model for a specific human disease has provided a powerful tool to understand the etiology of a disease and discovery of novel therapeutics. This chapter describes in detail the step-by-step generation of the transgenic mouse model, which can be helpful in guiding new investigators in developing successful models. For practical purposes, we will describe the generation of a mouse model using pituitary tumor transforming gene (PTTG) as the candidate gene of interest. PMID:25636481

  11. MYC oncogene overexpression drives renal cell carcinoma in a mouse model through glutamine metabolism

    PubMed Central

    Shroff, Emelyn H.; Eberlin, Livia S.; Dang, Vanessa M.; Gouw, Arvin M.; Gabay, Meital; Adam, Stacey J.; Bellovin, David I.; Tran, Phuoc T.; Philbrick, William M.; Garcia-Ocana, Adolfo; Casey, Stephanie C.; Li, Yulin; Dang, Chi V.; Zare, Richard N.; Felsher, Dean W.

    2015-01-01

    The MYC oncogene is frequently mutated and overexpressed in human renal cell carcinoma (RCC). However, there have been no studies on the causative role of MYC or any other oncogene in the initiation or maintenance of kidney tumorigenesis. Here, we show through a conditional transgenic mouse model that the MYC oncogene, but not the RAS oncogene, initiates and maintains RCC. Desorption electrospray ionization–mass-spectrometric imaging was used to obtain chemical maps of metabolites and lipids in the mouse RCC samples. Gene expression analysis revealed that the mouse tumors mimicked human RCC. The data suggested that MYC-induced RCC up-regulated the glutaminolytic pathway instead of the glycolytic pathway. The pharmacologic inhibition of glutamine metabolism with bis-2-(5-phenylacetamido-1,2,4-thiadiazol-2-yl)ethyl sulfide impeded MYC-mediated RCC tumor progression. Our studies demonstrate that MYC overexpression causes RCC and points to the inhibition of glutamine metabolism as a potential therapeutic approach for the treatment of this disease. PMID:25964345

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

    EPA Science Inventory

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

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

  13. In vitro transformation of mouse testis cells by oncogene transfection.

    PubMed

    Morimoto, Hiroko; Lee, Jiyoung; Tanaka, Takashi; Ishii, Kei; Toyokuni, Shinya; Kanatsu-Shinohara, Mito; Shinohara, Takashi

    2012-05-01

    Germ cell tumors (GCTs) are unique in that they exhibit diverse biological characteristics and pathological features. Although several in vivo GCT models are available, studies on GCTs are hampered because in vivo development of GCTs is time consuming and prevents a detailed molecular analysis of the transformation process. Here we developed a novel strategy to transform mouse testis cells in vitro. Lentivirus-mediated transfection of dominant negative Trp53, Myc, and activated Hras1 into a CD9-expressing testis cells caused tumorigenic conversion in vitro. Although these cells resembled embryonic stem (ES) cells, they were aneuploid and lacked Nanog expression, which is involved in the maintenance of the undifferentiated state in ES cells. Euploid ES-like cells were produced by transfecting the Yamanaka factors (Pou5f1, Myc, Klf4, and Sox2) into the same cell population. Although these cells expressed Nanog, they were distinct from ES cells in that they expressed CD44, a cancer stem cell antigen. Both treatments induced similar changes in the DNA methylation patterns in differentially methylated regions of imprinted genes. Moreover, despite the differences in their phenotype and karyotype, both cell types similarly produced mixed GCTs on transplantation, which were composed of teratomas, seminomas, and embryonal carcinomas. Thus, in vitro testis cell transformation facilitates an analysis of the GCT formation process, and our results also suggest the close similarity between GCT formation and reprogramming. PMID:22357549

  14. Glioma-associated endothelial cells are chemoresistant to temozolomide.

    PubMed

    Virrey, Jenilyn J; Golden, Encouse B; Sivakumar, Walavan; Wang, Weijun; Pen, Ligaya; Schönthal, Axel H; Hofman, Florence M; Chen, Thomas C

    2009-10-01

    Temozolomide is considered the standard of care and drug of choice for the treatment of initially diagnosed malignant gliomas. Although well tolerated, temozolomide still has limited clinical efficacy. Following drug treatment, patient prognosis still remains poor; tumor recurrence is almost universal. We hypothesized that this lack of effectiveness with temozolomide is because this drug does not target the glioma microenvironment, which is highly vascular in malignant gliomas. To test this hypothesis we analyzed the effects of temozolomide on the tumor vasculature in vitro and in vivo. We found that this drug did not affect the viability or proliferation rate of endothelial cells isolated from human glioma specimens, although temozolomide was highly cytotoxic to the glioma cell lines U87MG and U251. Furthermore, temozolomide did not inhibit the migration of these glioma-associated endothelial cells, a key mechanism responsible for tumor angiogenesis. In in vivo studies, using the intracranial glioma mouse model, temozolomide did not cause a pronounced effect on microvessel density. Our findings show that temozolomide has no apparent effect on the glioma vascular microenvironment. Thus combination therapy with anti-vascular agents may enhance temozolomide effectiveness as glioma therapeutic protocol.

  15. Mouse Elk oncogene maps to chromosome X and a novel Elk oncogene (Elk3) maps to chromosome 10

    SciTech Connect

    Tamai, Yoshitaka; Taketo, Makoto; Nozaki, Masami

    1995-03-20

    The Elk protein is a member of the Ets family found in both vertebrates and invertebrates. Human ELK1 encoded by ELK1 binds alone or together with serum response factor to DNA and regulates gene expression in a variety of biological processes. Using a panel of interspecific backcross mice, we have mapped the Elk oncogene (Elk) and a novel type Elk oncogene (Elk3), closely related to ELK1. Elk maps to Chr X, and Elk3 maps to the proximal region of Chr 10. 18 refs., 1 fig., 1 tab.

  16. Multiple tumor types appear in a transgenic mouse with the ras oncogene.

    PubMed Central

    Cardiff, R. D.; Leder, A.; Kuo, A.; Pattengale, P. K.; Leder, P.

    1993-01-01

    A transgenic mouse strain with the zeta-globin promoter and the vHa-ras oncogene develops an array of mesenchymal and epithelial neoplasms described here. The predominate mesenchymal tumors were dermal spindle cell tumors, which resembled malignant fibrous histiocytomas found in humans. They were associated with hepatosplenomegaly and developed beneath squamous papillomas. The hepatosplenomegaly was associated with infiltrates of cells that tended toward myelocytic or monocytic differentiation. Other epithelial tumors included keratoacanthomas and squamous cell carcinomas. Squamous cysts, some with squamous cell carcinomas, of the salivary glands and mammary carcinomas were also found. Odontogenic tumors, which sometimes differentiated into ameloblastomas, were one of the more unusual tumor types observed. Other, less frequent tumors were also noted. The tumors described here are a potentially valuable experimental resource that may lead to an understanding of malignant fibrous histiocytoma-like lesions, odontogenic tumors, and tumor progression. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8475993

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

    PubMed

    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.

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

    PubMed

    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. PMID:25624498

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

    PubMed

    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.

  20. INDUCTION OF DNA ADDUCTS, TUMORS, AND KI-RAS ONCOGENE MUTATIONS IN STRAIN A/J MOUSE LUNG BY IP. ADMINISTRATION OF DIBENZ[A,H]ANTHRACENE

    EPA Science Inventory

    Induction of DNA adducts, tumors, and Ki-ras oncogene mutations in strain AlJ mouse lung by ip. administration of dibenz[a,h]anthracene

    Previous studies of polycyclic aromatic hydrocarbon (P AH) induced lung tumors in the strain NJ mouse model system have demonstrated qua...

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

    PubMed

    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.

  2. Differential Sensitivity of Mouse Epithelial Tissues to the Polyomavirus Middle T Oncogene

    PubMed Central

    Cecena, Grace; Wen, Fang; Cardiff, Robert D.; Oshima, Robert G.

    2006-01-01

    To determine how different epithelial cell types respond to the same oncogenic stimulation, we have used a modified human keratin 18 gene to conditionally express the polyomavirus middle T antigen (PyMT) oncogene in simple epithelial tissues of transgenic mice. Activation of PyMT expression by transgenic Cre recombinase in mammary epithelial cells resulted in carcinomas in all bitransgenic females. PyMT expression induced by K18-driven Cre in internal epithelial organs resulted in pancreatic acinar metaplasia and ductal dysplasia with remarkable desmoplastic stromal responses in all 25 bitransgenic mice. Hepatoma formation with altered lipid metabolism and gastric adenocarcinoma occurred in 96 and 54% of these mice, respectively. Elevated PyMT RNA expression also correlated with intraepithelial neoplasia in the prostate. Activated Erk2 was found in mammary tumors, pancreatic tissues, and affected livers. Hes1 RNA, a target of Notch signaling that has been implicated downstream of Ras pathway activation, was elevated in pancreatic and liver lesions. The variety of responses of different epithelia to PyMT demonstrates the importance of the differentiated state in interpreting oncogenic signals. PMID:16400032

  3. Co-Localization of Somatic and Meiotic Double Strand Breaks Near the Myc Oncogene on Mouse Chromosome 15

    PubMed Central

    Ng, Siemon H.; Maas, Sarah A.; Petkov, Petko M.; Mills, Kevin D.; Paigen, Kenneth

    2010-01-01

    Both somatic and meiotic recombinations involve the repair of DNA double strand breaks (DSBs) that occur at preferred locations in the genome. Improper repair of DSBs during either mitosis or meiosis can lead to mutations, chromosomal aberration such as translocations, cancer and/or cell death. Currently, no model exists that explains the locations of either spontaneous somatic DSBs or programmed meiotic DSBs or relates them to each other. One common class of tumorigenic translocations arising from DSBs is chromosomal rearrangements near the Myc oncogene. Myc translocations have been associated with Burkitt lymphoma in humans, plasmacytoma in mice and immunocytoma in rats. Comparing the locations of somatic and meiotic DSBs near the mouse Myc oncogene, we demonstrated that the placement of these DSBs is not random and that both events clustered in the same short discrete region of the genome. Our work shows that both somatic and meiotic DSBs tend to occur in proximity to each other within the Myc region, suggesting that they share common originating features. It is likely that some regions of the genome are more susceptible to both somatic and meiotic DSBs, and the locations of meiotic hotspots may be an indicator of genomic regions more susceptible to DNA damage. PMID:19603522

  4. Mouse model of intrahepatic cholangiocarcinoma validates FIG-ROS as a potent fusion oncogene and therapeutic target.

    PubMed

    Saborowski, Anna; Saborowski, Michael; Davare, Monika A; Druker, Brian J; Klimstra, David S; Lowe, Scott W

    2013-11-26

    Cholangiocarcinoma is the second most common primary liver cancer and responds poorly to existing therapies. Intrahepatic cholangiocarcinoma (ICC) likely originates from the biliary tree and develops within the hepatic parenchyma. We have generated a flexible orthotopic allograft mouse model of ICC that incorporates common genetic alterations identified in human ICC and histologically resembles the human disease. We examined the utility of this model to validate driver alterations in ICC and tested their suitability as therapeutic targets. Specifically, we showed that the fused-in-glioblastoma-c-ros-oncogene1 (FIG-ROS1(S); FIG-ROS) fusion gene dramatically accelerates ICC development and that its inactivation in established tumors has a potent antitumor effect. Our studies establish a versatile model of ICC that will be a useful preclinical tool and validate ROS1 fusions as potent oncoproteins and therapeutic targets in ICC and potentially other tumor types.

  5. AKT1E¹⁷K Is Oncogenic in Mouse Lung and Cooperates with Chemical Carcinogens in Inducing Lung Cancer.

    PubMed

    Malanga, Donatella; Belmonte, Stefania; Colelli, Fabiana; Scarfò, Marzia; De Marco, Carmela; Oliveira, Duarte Mendes; Mirante, Teresa; Camastra, Caterina; Gagliardi, Monica; Rizzuto, Antonia; Mignogna, Chiara; Paciello, Orlando; Papparella, Serenella; Fagman, Henrik; Viglietto, Giuseppe

    2016-01-01

    The hotspot AKT1E17K mutation in the pleckstrin homology domain of AKT1 occurs in approximately 0.6-2% of human lung cancers. Recently, we have demonstrated that AKT1E17K transforms immortalized human bronchial cells. Here by use of a transgenic Cre-inducible murine strain in the wild type Rosa26 (R26) locus (R26-AKT1E17K mice) we demonstrate that AKT1E17K is a bona-fide oncogene and plays a role in the development of lung cancer in vivo. In fact, we report that mutant AKT1E17K induces bronchial and/or bronchiolar hyperplastic lesions in murine lung epithelium, which progress to frank carcinoma at very low frequency, and accelerates tumor formation induced by chemical carcinogens. In conclusion, AKT1E17K induces hyperplasia of mouse lung epithelium in vivo and cooperates with urethane to induce the fully malignant phenotype.

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

    PubMed

    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.

  7. Overlapping and specific functions of Braf and Craf-1 proto-oncogenes during mouse embryogenesis.

    PubMed

    Wojnowski, L; Stancato, L F; Larner, A C; Rapp, U R; Zimmer, A

    2000-03-01

    The three mammalian Raf serine/threonine protein kinases mediate the transduction of proliferative and differentiative signals from cell surface receptors to the nucleus. In vertebrates, Raf signaling has been implicated in the progression of mouse embryos through the two-cell stage and in the induction of posterior mesoderm. However, mouse embryos mutant for each of the Raf genes exhibit no developmental defects before mid-gestation. Here we describe the phenotype of mouse mutants with different combinations of mutant Craf-1 and Braf alleles. Our results show that Raf signaling is indeed indispensable for normal development beyond the blastocyst stage. However, due to a significant redundancy between Craf-1 and Braf, either gene is sufficient for normal development until mid-gestation. The molecular and developmental mechanisms for this redundancy were investigated by monitoring the expression of Raf genes throughout embryogenesis and by biochemical studies in mutant cell lines.

  8. AKT1E17K Is Oncogenic in Mouse Lung and Cooperates with Chemical Carcinogens in Inducing Lung Cancer

    PubMed Central

    Malanga, Donatella; Belmonte, Stefania; Colelli, Fabiana; Scarfò, Marzia; De Marco, Carmela; Oliveira, Duarte Mendes; Mirante, Teresa; Camastra, Caterina; Gagliardi, Monica; Rizzuto, Antonia; Mignogna, Chiara; Paciello, Orlando; Papparella, Serenella; Fagman, Henrik; Viglietto, Giuseppe

    2016-01-01

    The hotspot AKT1E17K mutation in the pleckstrin homology domain of AKT1 occurs in approximately 0.6–2% of human lung cancers. Recently, we have demonstrated that AKT1E17K transforms immortalized human bronchial cells. Here by use of a transgenic Cre-inducible murine strain in the wild type Rosa26 (R26) locus (R26-AKT1E17K mice) we demonstrate that AKT1E17K is a bona-fide oncogene and plays a role in the development of lung cancer in vivo. In fact, we report that mutant AKT1E17K induces bronchial and/or bronchiolar hyperplastic lesions in murine lung epithelium, which progress to frank carcinoma at very low frequency, and accelerates tumor formation induced by chemical carcinogens. In conclusion, AKT1E17K induces hyperplasia of mouse lung epithelium in vivo and cooperates with urethane to induce the fully malignant phenotype. PMID:26859676

  9. Continued withdrawal from the cell cycle and regulation of cellular genes in mouse erythroleukemia cells blocked in differentiation by the c-myc oncogene.

    PubMed Central

    Coppola, J A; Parker, J M; Schuler, G D; Cole, M D

    1989-01-01

    Constitutive expression of the c-myc oncogene blocks dimethyl sulfoxide (DMSO)-induced differentiation of mouse erythroleukemia (MEL) cells. During the first 12 h of treatment with DMSO, MEL cells undergo a temporary decrease in the level of c-myc mRNA, followed by a temporary withdrawal from the cell cycle. We found the same shutoff of DNA synthesis during the first 12 to 30 h after DMSO induction in normal MEL cells (which differentiate) and in c-myc-transfected MEL cells (which do not differentiate). We also examined whether deregulated c-myc expression grossly interfered with the regulation of gene expression during MEL cell differentiation. We used run-on transcription assays to monitor the rate of transcription of four oncogenes (c-myc, c-myb, c-fos, and c-K-ras); all except c-K-ras showed a rapid but temporary decrease in transcription after induction in both c-myc-transfected and control cells. Finally, we found the same regulation of cytoplasmic mRNA expression in both types of cells for four oncogenes and three housekeeping genes associated with growth. We conclude that in the MEL cell system, the effects of deregulated c-myc expression do not occur through a disruption of cell cycle control early in induction, nor do they occur through gross deregulation of gene expression. Images PMID:2657403

  10. Normal ABL1 is a tumor suppressor and therapeutic target in human and mouse leukemias expressing oncogenic ABL1 kinases.

    PubMed

    Dasgupta, Yashodhara; Koptyra, Mateusz; Hoser, Grazyna; Kantekure, Kanchan; Roy, Darshan; Gornicka, Barbara; Nieborowska-Skorska, Margaret; Bolton-Gillespie, Elisabeth; Cerny-Reiterer, Sabine; Müschen, Markus; Valent, Peter; Wasik, Mariusz A; Richardson, Christine; Hantschel, Oliver; van der Kuip, Heiko; Stoklosa, Tomasz; Skorski, Tomasz

    2016-04-28

    Leukemias expressing constitutively activated mutants of ABL1 tyrosine kinase (BCR-ABL1, TEL-ABL1, NUP214-ABL1) usually contain at least 1 normal ABL1 allele. Because oncogenic and normal ABL1 kinases may exert opposite effects on cell behavior, we examined the role of normal ABL1 in leukemias induced by oncogenic ABL1 kinases. BCR-ABL1-Abl1(-/-) cells generated highly aggressive chronic myeloid leukemia (CML)-blast phase-like disease in mice compared with less malignant CML-chronic phase-like disease from BCR-ABL1-Abl1(+/+) cells. Additionally, loss of ABL1 stimulated proliferation and expansion of BCR-ABL1 murine leukemia stem cells, arrested myeloid differentiation, inhibited genotoxic stress-induced apoptosis, and facilitated accumulation of chromosomal aberrations. Conversely, allosteric stimulation of ABL1 kinase activity enhanced the antileukemia effect of ABL1 tyrosine kinase inhibitors (imatinib and ponatinib) in human and murine leukemias expressing BCR-ABL1, TEL-ABL1, and NUP214-ABL1. Therefore, we postulate that normal ABL1 kinase behaves like a tumor suppressor and therapeutic target in leukemias expressing oncogenic forms of the kinase. PMID:26864341

  11. Structure, chromosome location, and expression of the mouse zinc finger gene Krox-20: multiple gene products and coregulation with the proto-oncogene c-fos.

    PubMed Central

    Chavrier, P; Janssen-Timmen, U; Mattéi, M G; Zerial, M; Bravo, R; Charnay, P

    1989-01-01

    We have analyzed the structure and the regulation of Krox-20, a mouse zinc finger-encoding gene which is transiently activated following serum stimulation of quiescent fibroblast cells in culture. The gene is localized on chromosome 10, band B5, in the mouse, and the homologous human gene also maps to chromosome 10 (region q21.1 to q22.1). Alternative splicing of the 5'-most intron of the Krox-20 gene gives rise to mRNAs encoding putative zinc finger proteins with different N termini. The first exon contains a sequence element with strong similarity to the c-fos proto-oncogene serum response element (SRE). This element can functionally substitute for the c-fos SRE, and it binds the same nuclear protein. It is probably responsible for the serum induction of Krox-20, possibly in combination with a weaker SRE located in the 5'-flanking region of the gene. Our findings suggest that c-fos, Krox-20, and a number of immediate-early serum response genes are coregulated and that the SRE and its cognate protein are essential components of this regulatory pathway. Images PMID:2496302

  12. Glioma-associated oncogene homolog 1 promotes epithelial-mesenchymal transition in human renal tubular epithelial cell.

    PubMed

    Ding, Hong; Xu, Yanyan; Gao, Di; Wang, Lei

    2016-01-01

    Sonic hedgehog (Shh) signaling critically regulates embryogenesis and tissue homeostasis. Here, we investigated the role of Shh signaling in mediating epithelial-mesenchymal transition (EMT) in human renal tubular epithelial cells HKC-8. Our RT-PCR assays demonstrated that TGF-β1 induced time-dependent changes in the mRNA transcript levels of Shh, with a steady rise from one hour post TGF-β1 treatment and a peak at four hours post TGF-β1 treatment. Furthermore, TGF-β1 induced a time-dependent increase in the mRNA transcript levels of Gli1. Pre-treatment with 2 or 5 µM cyclopamine significantly attenuated TGF-β1-induced rise in the mRNA transcript levels of Gli1, but failed to attenuate TGF-β1-induced rise in Shh mRNA transcript levels. Additionally, immunoblotting assays and immunofluorescence staining demonstrated that inhibition of Shh signaling by cyclopamine significantly attenuated TGF-β1-induced increase in the mRNA transcript levels of α-SMA, collagen I, and fibronectin. Gli1 overexpression induced Snail1 expression. Moreover, Gli(-/-) mice that had undergone unilateral ureteral obstruction for seven days showed significant reduction in the mRNA transcript levels of Snail1 compared to the wildtype controls. In conclusion, the current study provides novel insight into the regulation of EMT by the Shh/Gli1 signaling pathway, suggesting a critical role of Shh/Gli1 signaling in EMT of human renal tubular epithelial cells. PMID:27158358

  13. Patterns of scAAV vector insertion associated with oncogenic events in a mouse model for genotoxicity.

    PubMed

    Rosas, Lucia E; Grieves, Jessica L; Zaraspe, Kimberly; La Perle, Krista Md; Fu, Haiyan; McCarty, Douglas M

    2012-11-01

    Recombinant adeno-associated virus (rAAV) vectors have gained an extensive record of safety and efficacy in animal models of human disease. Infrequent reports of genotoxicity have been limited to specific vectors associated with excess hepatocellular carcinomas (HCC) in mice. In order to understand potential mechanisms of genotoxicity, and identify patterns of insertion that could promote tumor formation, we compared a self-complementary AAV (scAAV) vector designed to promote insertional activation (scAAV-CBA-null) to a conventional scAAV-CMV-GFP vector. HCC-prone C3H/HeJ mice and severe combined immunodeficiency (SCID) mice were infected with vector plus secondary treatments including partial hepatectomy (HPX) and camptothecin (CPT) to determine the effects of cell cycling and DNA damage on tumor incidence. Infection with either vector led to a significant increase in HCC incidence in male C3H/HeJ mice. Partial HPX after infection reduced HCC incidence in the cytomegalovirus-green fluorescent protein (CMV-GFP)-infected mice, but not in the cognate chicken β-actin (CBA)-null infected group. Tumors from CBA-null infected, hepatectomized mice were more likely to contain significant levels of vector DNA than tumors from the corresponding CMV-GFP-infected group. Most CBA-null vector insertions recovered from tumors were associated with known proto-oncogenes or tumor suppressors. Specific patterns of insertion suggested read-through transcription, enhancer effects, and disruption of tumor suppressors as likely mechanisms for genotoxicity.

  14. Klf5 Deletion Promotes Pten Deletion–Initiated Luminal-Type Mouse Prostate Tumors through Multiple Oncogenic Signaling Pathways12

    PubMed Central

    Xing, Changsheng; Ci, Xinpei; Sun, Xiaodong; Fu, Xiaoying; Zhang, Zhiqian; Dong, Eric N.; Hao, Zhao-Zhe; Dong, Jin-Tang

    2014-01-01

    Krüppel-like factor 5 (KLF5) regulates multiple biologic processes. Its function in tumorigenesis appears contradictory though, showing both tumor suppressor and tumor promoting activities. In this study, we examined whether and how Klf5 functions in prostatic tumorigenesis using mice with prostate-specific deletion of Klf5 and phosphatase and tensin homolog (Pten), both of which are frequently inactivated in human prostate cancer. Histologic analysis demonstrated that when one Pten allele was deleted, which causes mouse prostatic intraepithelial neoplasia (mPIN), Klf5 deletion accelerated the emergence and progression of mPIN. When both Pten alleles were deleted, which causes prostate cancer, Klf5 deletion promoted tumor growth, increased cell proliferation, and caused more severe morphologic and molecular alterations. Homozygous deletion of Klf5 was more effective than hemizygous deletion. Unexpectedly, while Pten deletion alone expanded basal cell population in a tumor as reported, Klf5 deletion in the Pten-null background clearly reduced basal cell population while expanding luminal cell population. Global gene expression profiling, pathway analysis, and experimental validation indicate that multiple mechanisms could mediate the tumor-promoting effect of Klf5 deletion, including the up-regulation of epidermal growth factor and its downstream signaling molecules AKT and ERK and the inactivation of the p15 cell cycle inhibitor. KLF5 also appears to cooperate with several transcription factors, including CREB1, Sp1, Myc, ER and AR, to regulate gene expression. These findings validate the tumor suppressor function of KLF5. They also yield a mouse model that shares two common genetic alterations with human prostate cancer—mutation/deletion of Pten and deletion of Klf5. PMID:25425963

  15. In vivo identification of tumor- suppressive PTEN ceRNAs in an oncogenic BRAF-induced mouse model of melanoma.

    PubMed

    Karreth, Florian A; Tay, Yvonne; Perna, Daniele; Ala, Ugo; Tan, Shen Mynn; Rust, Alistair G; DeNicola, Gina; Webster, Kaitlyn A; Weiss, Dror; Perez-Mancera, Pedro A; Krauthammer, Michael; Halaban, Ruth; Provero, Paolo; Adams, David J; Tuveson, David A; Pandolfi, Pier Paolo

    2011-10-14

    We recently proposed that competitive endogenous RNAs (ceRNAs) sequester microRNAs to regulate mRNA transcripts containing common microRNA recognition elements (MREs). However, the functional role of ceRNAs in cancer remains unknown. Loss of PTEN, a tumor suppressor regulated by ceRNA activity, frequently occurs in melanoma. Here, we report the discovery of significant enrichment of putative PTEN ceRNAs among genes whose loss accelerates tumorigenesis following Sleeping Beauty insertional mutagenesis in a mouse model of melanoma. We validated several putative PTEN ceRNAs and further characterized one, the ZEB2 transcript. We show that ZEB2 modulates PTEN protein levels in a microRNA-dependent, protein coding-independent manner. Attenuation of ZEB2 expression activates the PI3K/AKT pathway, enhances cell transformation, and commonly occurs in human melanomas and other cancers expressing low PTEN levels. Our study genetically identifies multiple putative microRNA decoys for PTEN, validates ZEB2 mRNA as a bona fide PTEN ceRNA, and demonstrates that abrogated ZEB2 expression cooperates with BRAF(V600E) to promote melanomagenesis. PMID:22000016

  16. Resveratrol prevents tumorigenesis in mouse model of Kras activated sporadic colorectal cancer by suppressing oncogenic Kras expression

    PubMed Central

    Saud, Shakir M.; Li, Weidong; Morris, Nicole L.; Matter, Matthias S.; Colburn, Nancy H.; Kim, Young S.; Young, Matthew R.

    2014-01-01

    Sporadic and non-hereditary mutations account for the majority of colorectal cancers (CRC). After the loss of adenomatous polyposis coli (APC) function and activation of the β-catenin/LEF signaling pathway, activating mutations in Kras are major drivers of sporadic CRC. Preventing the outgrowth of cells that develop sporadic mutations will decrease CRC. Resveratrol, a naturally occurring polyphenolic compound has anti-inflammatory, anti-oxidant and anti-cancer activities. We used a genetically engineered mouse model for sporadic CRC where the APC locus is knocked out and Kras is activated specifically in the distal colon to determine the effects of resveratrol on preventing and treating CRC. Feeding mice a diet supplemented with 150 or 300 ppm resveratrol (105 and 210mg daily human equivalent dose, respectively) before tumors were visible by colonoscopy resulted in a 60% inhibition of tumor production. In the 40% of mice that did develop tumors Kras expression was lost in the tumors. In a therapeutic assay where tumors were allowed to develop prior to treatment, feeding tumor bearing mice with resveratrol resulted in a complete remission in 33% of the mice and a 97% decrease in tumor size in the remaining mice. Analysis of miRNA expression in non-tumoral and tumoral colonic tissue of resveratrol treated mice showed an increased expression of miR-96, a miRNA previously shown to regulate Kras translation. These data indicate that resveratrol can prevent the formation and growth of colorectal tumors by downregulating Kras expression. PMID:25280562

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

    PubMed

    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.

  18. The role of proto-oncogene GLI1 in pituitary adenoma formation and cell survival regulation.

    PubMed

    Lampichler, Katharina; Ferrer, Patricio; Vila, Greisa; Lutz, Mirjam I; Wolf, Florian; Knosp, Engelbert; Wagner, Ludwig; Luger, Anton; Baumgartner-Parzer, Sabina

    2015-10-01

    The Hedgehog (Hh) pathway is an important regulator of early tissue patterning and stem cell propagation. It was found to be aberrantly activated in numerous types of human cancer and might be relevant in cancer stem cells. The identification of adult stem cells in the pituitary raised the question if tumor-initiating cells and Hh signaling are involved in pituitary adenoma formation. The present study aimed at the evaluation of Hh signaling in relation to stem cell and cell cycle markers in 30 human pituitary adenomas and in cultured murine adenoma cells. Therefore, expression levels of components of the Hh pathway, stem cell marker SOX2, cell cycle regulator tumor-protein 53 (TP53), proliferation marker Ki67 (MKI67) and superoxide dismutase 1 (SOD1) were evaluated in 30 human pituitary adenomas in comparison to control tissue. Modulation of cell function and target gene expression by the inhibition and activation of the Hh pathway were studied in murine adenoma cells. We show that transcription factor glioma-associated oncogene 1 (GLI1) is overexpressed in 87% of all pituitary adenomas. The expression of GLI1 significantly correlated with that of SOX2, TP53, MKI67 and SOD1. Inhibition of GLI1 resulted in the downregulation of the above genes and severe cell death in mouse adenoma cells. On the other hand, activation of the Hh pathway increased cell viability and target gene expression. In conclusion, our findings point toward an alternative, ligand-independent Hh pathway activation with GLI1 playing a major role in the cell survival of pituitary adenoma cells. PMID:26219678

  19. Revealing the potential pathogenesis of glioma by utilizing a glioma associated protein-protein interaction network.

    PubMed

    Pan, Weiran; Li, Gang; Yang, Xiaoxiao; Miao, Jinming

    2015-04-01

    This study aims to explore the potential mechanism of glioma through bioinformatic approaches. The gene expression profile (GSE4290) of glioma tumor and non-tumor samples was downloaded from Gene Expression Omnibus database. A total of 180 samples were available, including 23 non-tumor and 157 tumor samples. Then the raw data were preprocessed using robust multiarray analysis, and 8,890 differentially expressed genes (DEGs) were identified by using t-test (false discovery rate < 0.0005). Furthermore, 16 known glioma related genes were abstracted from Genetic Association Database. After mapping 8,890 DEGs and 16 known glioma related genes to Human Protein Reference Database, a glioma associated protein-protein interaction network (GAPN) was constructed. In addition, 51 sub-networks in GAPN were screened out through Molecular Complex Detection (score ≥ 1), and sub-network 1 was found to have the closest interaction (score = 3). What' more, for the top 10 sub-networks, Gene Ontology (GO) enrichment analysis (p value < 0.05) was performed, and DEGs involved in sub-network 1 and 2, such as BRMS1L and CCNA1, were predicted to regulate cell growth, cell cycle, and DNA replication via interacting with known glioma related genes. Finally, the overlaps of DEGs and human essential, housekeeping, tissue-specific genes were calculated (p value = 1.0, 1.0, and 0.00014, respectively) and visualized by Venn Diagram package in R. About 61% of human tissue-specific genes were DEGs as well. This research shed new light on the pathogenesis of glioma based on DEGs and GAPN, and our findings might provide potential targets for clinical glioma treatment.

  20. Akt-mediated phosphorylation of Bmi1 modulates its oncogenic potential, E3 ligase activity, and DNA damage repair activity in mouse prostate cancer

    PubMed Central

    Nacerddine, Karim; Beaudry, Jean-Bernard; Ginjala, Vasudeva; Westerman, Bart; Mattiroli, Francesca; Song, Ji-Ying; van der Poel, Henk; Ponz, Olga Balagué; Pritchard, Colin; Cornelissen-Steijger, Paulien; Zevenhoven, John; Tanger, Ellen; Sixma, Titia K.; Ganesan, Shridar; van Lohuizen, Maarten

    2012-01-01

    Prostate cancer (PCa) is a major lethal malignancy in men, but the molecular events and their interplay underlying prostate carcinogenesis remain poorly understood. Epigenetic events and the upregulation of polycomb group silencing proteins including Bmi1 have been described to occur during PCa progression. Here, we found that conditional overexpression of Bmi1 in mice induced prostatic intraepithelial neoplasia, and elicited invasive adenocarcinoma when combined with PTEN haploinsufficiency. In addition, Bmi1 and the PI3K/Akt pathway were coactivated in a substantial fraction of human high-grade tumors. We found that Akt mediated Bmi1 phosphorylation, enhancing its oncogenic potential in an Ink4a/Arf-independent manner. This process also modulated the DNA damage response and affected genomic stability. Together, our findings demonstrate the etiological role of Bmi1 in PCa, unravel an oncogenic collaboration between Bmi1 and the PI3K/Akt pathway, and provide mechanistic insights into the modulation of Bmi1 function by phosphorylation during prostate carcinogenesis. PMID:22505453

  1. Structure-Activity Relationships and Cancer-Cell Selective Toxicity of Novel Inhibitors of Glioma-Associated Oncogene Homolog 1 (Gli1)-Mediated Transcription

    PubMed Central

    Mahindroo, Neeraj; Connelly, Michele C.; Punchihewa, Chandanamali; Kimura, Hiromichi; Smeltzer, Matthew P.; Wu, Song; Fujii, Naoaki

    2010-01-01

    We report novel inhibitors of Gli1-mediated transcription as potential anticancer agents. Focused chemical libraries were designed and assessed for inhibition of functional cell-based Gli1-mediated transcription and selective toxicity toward cancer cells. The SAR was revealed and the selectivity of the lead compounds’ inhibition of Gli1-mediated transcription over that of Gli2 was determined. Compound 63 (NMDA298-1), which inhibited Gli1-mediated transcription in C3H10T1/2 cells with an IC50 of 6.9 µM, showed 3-fold selectivity for inhibiting transcription mediated by Gli1 over that by Gli2. Cell-viability assays were performed to evaluate the chemical library in a normal cell line and a panel of cancer cell lines with or without upregulated expression of the Gli1 gene. These compounds decreased the viability of several cancer cell lines but were less active in that of noncancerous BJ-hTERT cells. PMID:19545120

  2. A novel mouse model for inhibition of DOHH-mediated hypusine modification reveals a crucial function in embryonic development, proliferation and oncogenic transformation

    PubMed Central

    Sievert, Henning; Pällmann, Nora; Miller, Katharine K.; Hermans-Borgmeyer, Irm; Venz, Simone; Sendoel, Ataman; Preukschas, Michael; Schweizer, Michaela; Boettcher, Steffen; Janiesch, P. Christoph; Streichert, Thomas; Walther, Reinhard; Hengartner, Michael O.; Manz, Markus G.; Brümmendorf, Tim H.; Bokemeyer, Carsten; Braig, Melanie; Hauber, Joachim; Duncan, Kent E.; Balabanov, Stefan

    2014-01-01

    The central importance of translational control by post-translational modification has spurred major interest in regulatory pathways that control translation. One such pathway uniquely adds hypusine to eukaryotic initiation factor 5A (eIF5A), and thereby affects protein synthesis and, subsequently, cellular proliferation through an unknown mechanism. Using a novel conditional knockout mouse model and a Caenorhabditis elegans knockout model, we found an evolutionarily conserved role for the DOHH-mediated second step of hypusine synthesis in early embryonic development. At the cellular level, we observed reduced proliferation and induction of senescence in 3T3 Dohh−/− cells as well as reduced capability for malignant transformation. Furthermore, mass spectrometry showed that deletion of DOHH results in an unexpected complete loss of hypusine modification. Our results provide new biological insight into the physiological roles of the second step of the hypusination of eIF5A. Moreover, the conditional mouse model presented here provides a powerful tool for manipulating hypusine modification in a temporal and spatial manner, to analyse both how this unique modification normally functions in vivo as well as how it contributes to different pathological conditions. PMID:24832488

  3. Identification of a novel mouse Dbl proto-oncogene splice variant: evidence that SEC14 domain is involved in GEF activity regulation.

    PubMed

    Ognibene, Marzia; Vanni, Cristina; Blengio, Fabiola; Segalerba, Daniela; Mancini, Patrizia; De Marco, Patrizia; Torrisi, Maria R; Bosco, Maria C; Varesio, Luigi; Eva, Alessandra

    2014-03-10

    The Rho guanine nucleotide exchange factor protoDbl is involved in different biochemical pathways affecting cell proliferation and migration. The N-terminal sequence of protoDbl contains negative regulatory elements that restrict the catalytic activity of the DH-PH module. Here, we report the identification of a new mouse protoDbl splice variant lacking exon 3. We found that the splice variant mRNA is expressed in the spleen and bone marrow lymphocytes, adrenal gland, gonads and brain. The protoDbl variant protein was detectable in the brain. The newly identified variant displays the disruption of the SEC14 domain, positioned on exons 2 and 3 in the protoDbl N-terminal region. We show here that an altered SEC14 sequence leads to enhanced Dbl translocation to the plasma membrane and to augmented transforming and exchange activity.

  4. Oncogenes and surgical pathology.

    PubMed

    Bartow, S A

    1987-08-01

    The discovery of oncogenes began with identification of genetic material in viruses capable of causing neoplasia in animals. Through processes of "transduction" and "insertional mutagenesis," RNA/retroviruses may (1) alter directly, (2) alter expression of, or (3) move pieces of host cellular genome in ways that they become potential agents of neoplastic transformation. The pieces of host cellular genome, either affected in situ by viral gene insertion or transduced by the virus, are known as oncogenes. Approximately 20 oncogenes have been identified. Although they have yet to be proven to be sufficient or necessary for neoplastic transformation, the evidence for their playing a part in the transformation process is mounting. The functions of the protein products of the various oncogenes are closely related to those of proteins involved in normal cell regulatory and cycle activities. Study of the oncogene products and their functions serves to elucidate the basic character of neoplasia. The functional classes of oncogenes with specific examples of genomic amplification, altered mRNA or protein product expression, or mutational deletion associated with human neoplasia are reviewed herein. Since the techniques for detecting oncogene DNA and mRNA alterations are rapidly becoming a part of our diagnostic armamentarium, surgical pathologists should be prepared for the imminent use of such molecular techniques and information in diagnosis and prognosis of human neoplasia.

  5. Tenascin-W is a specific marker of glioma-associated blood vessels and stimulates angiogenesis in vitro.

    PubMed

    Martina, Enrico; Degen, Martin; Rüegg, Curzio; Merlo, Adrian; Lino, Maddalena M; Chiquet-Ehrismann, Ruth; Brellier, Florence

    2010-03-01

    The microenvironment hosting a tumor actively participates in regulating tumor cell proliferation, migration, and invasion. Among the extracellular matrix proteins enriched in the stroma of carcinomas are the tenascin family members tenascin-C and tenascin-W. Whereas tenascin-C overexpression in gliomas is known to correlate with poor prognosis, the status of tenascin-W in brain tumors has not been investigated so far. In the present study, we analyzed protein levels of tenascin-W in 38 human gliomas and found expression of tenascin-W in 80% of the tumor samples, whereas no tenascin-W could be detected in control, nontumoral brain tissues. Double immunohistochemical staining of tenascin-W and von Willebrand factor revealed that tenascin-W is localized around blood vessels, exclusively in tumor samples. In vitro, the presence of tenascin-W increased the proportion of elongated human umbilical vein endothelial cells (HUVECs) and augmented the mean speed of cell migration. Furthermore, tenascin-W triggered sprouting of HUVEC spheroids to a similar extent as the proangiogenic factor tenascin-C. In conclusion, our study identifies tenascin-W as a candidate biomarker for brain tumor angiogenesis that could be used as a molecular target for therapy irrespective of the glioma subtype.-Martina, E., Degen, M., Rüegg, C., Merlo, A., Lino, M. M., Chiquet-Ehrismann, R., Brellier, F. Tenascin-W is a specific marker of glioma-associated blood vessels and stimulates angiogenesis in vitro.

  6. Enhancer hijacking activates GFI1 family oncogenes in medulloblastoma.

    PubMed

    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.

  7. Mapping of the Pim-1 oncogene in mouse t-haplotypes and its use to define the relative map positions of the tcl loci t0(t6) and tw12 and the marker tf (tufted).

    PubMed

    Ark, B; Gummere, G; Bennett, D; Artzt, K

    1991-06-01

    Pim-1 is an oncogene activated in mouse T-cell lymphomas induced by Moloney and AKR mink cell focus (MCF) viruses. Pim-1 was previously mapped to chromosome 17 by somatic cell hybrids, and subsequently to the region between the hemoglobin alpha-chain pseudogene 4 (Hba-4ps) and the alpha-crystalline gene (Crya-1) by Southern blot analysis of DNA obtained from panels of recombinant inbred strains. We have now mapped Pim-1 more accurately in t-haplotypes by analysis of recombinant t-chromosomes. The recombinants were derived from Tts6tf/t12 parents backcrossed to + tf/ + tf, and scored for recombination between the loci of T and tf. For simplicity all t-complex lethal genes properly named tcl-tx are shortened to tx. The Pim-1 gene was localized 0.6 cM proximal to the tw12 lethal gene, thus placing the Pim-1 gene 5.2 cM distal to the H-2 region in t-haplotypes. Once mapped, the Pim-1 gene was used as a marker for further genetic analysis of t-haplotypes. tw12 is so close to tf that even with a large number of recombinants it was not possible to determine whether it is proximal or distal to tf. Southern blot analysis of DNA from T-tf recombinants with a separation of tw12 and tf indicated that tw12 is proximal to tf. The mapping of two allelic t-lethals, t0 and t6 with respect to tw12 and tf has also been a problem.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Pesticides and oncogenic modulation.

    PubMed

    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.

  9. [Atherosclerosis and oncogenes].

    PubMed

    Onraed-Dupriez, B

    1992-01-01

    Atherosclerosis, a leading cause of mortality in the developed world, has mainly been studied with respect to the pathogenic role of lipids. However, over the last few years, a new avenue of research has stemmed from Benditt's monoclonal theory which linkens the atheroma plaque to a benign tumor developed from a single smooth muscle cell. Investigations into mechanisms capable of initiating this monoclonal cell growth have included studies of protooncogene activation. Barrett and Benditt have reported increased expression of the sis oncogene in the atheroma plaque; the product of this oncogene is very similar to the beta chain of platelet-derived growth factor (PDGF) which may play a role in the development of the atheroma plaque. These recent studies focusing on the earliest step of formation of the atheroma plaque, ie, cell growth, complement the pathophysiologic theories studied until now.

  10. Oncogenes and growth control

    SciTech Connect

    Kahn, P.; Graf, T.

    1986-01-01

    This book contains six sections, each consisting of several papers. Some of the paper titles are: A Role for Proto-Oncogenes in Differentiation.; The ras Gene Family; Regulation of Human Globin Gene Expression; Regulation of Gene Expression by Steroid Hormones; The Effect of DNA Methylation on DNA-Protein Interactions and on the Regulation of Gene Expression; and Trans-Acting Elements Encoded in Immediate Early Genes of DNA Tumor Viruses.

  11. The human oncogenic viruses

    SciTech Connect

    Luderer, A.A.; Weetall, H.H

    1986-01-01

    This book contains eight selections. The titles are: Cytogenetics of the Leukemias and Lymphomas; Cytogenetics of Solid Tumors: Renal Cell Carcinoma, Malignant Melanoma, Retinoblastoma, and Wilms' Tumor; Elucidation of a Normal Function for a Human Proto-Oncogene; Detection of HSV-2 Genes and Gene Products in Cervical Neoplasia; Papillomaviruses in Anogennital Neoplasms; Human Epstein-Barr Virus and Cancer; Hepatitis B Virus and Hepatocellular Carcinoma; and Kaposi's Sarcoma: Acquired Immunodeficiency Syndrome (AIDS) and Associated Viruses.

  12. Oncogenes in melanoma: an update.

    PubMed

    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. PMID:24468268

  13. Developmental-stage-dependent transcriptional response to leukaemic oncogene expression

    PubMed Central

    Regha, Kakkad; Assi, Salam A.; Tsoulaki, Olga; Gilmour, Jane; Lacaud, Georges; Bonifer, Constanze

    2015-01-01

    Acute myeloid leukaemia (AML) is characterized by a block in myeloid differentiation the stage of which is dependent on the nature of the transforming oncogene and the developmental stage of the oncogenic hit. This is also true for the t(8;21) translocation that gives rise to the RUNX1-ETO fusion protein and initiates the most common form of human AML. Here we study the differentiation of mouse embryonic stem cells expressing an inducible RUNX1-ETO gene into blood cells as a model, combined with genome-wide analyses of transcription factor binding and gene expression. RUNX1-ETO interferes with both the activating and repressive function of its normal counterpart, RUNX1, at early and late stages of blood cell development. However, the response of the transcriptional network to RUNX1-ETO expression is developmental stage specific, highlighting the molecular mechanisms determining specific target cell expansion after an oncogenic hit. PMID:26018585

  14. Principles of cancer therapy: oncogene and non-oncogene addiction.

    PubMed

    Luo, Ji; Solimini, Nicole L; Elledge, Stephen J

    2009-03-01

    Cancer is a complex collection of distinct genetic diseases united by common hallmarks. Here, we expand upon the classic hallmarks to include the stress phenotypes of tumorigenesis. We describe a conceptual framework of how oncogene and non-oncogene addictions contribute to these hallmarks and how they can be exploited through stress sensitization and stress overload to selectively kill cancer cells. In particular, we present evidence for a large class of non-oncogenes that are essential for cancer cell survival and present attractive drug targets. Finally, we discuss the path ahead to therapeutic discovery and provide theoretical considerations for combining orthogonal cancer therapies. PMID:19269363

  15. Tea polyphenols epigallocatechin gallete and theaflavin restrict mouse liver carcinogenesis through modulation of self-renewal Wnt and hedgehog pathways.

    PubMed

    Sur, Subhayan; Pal, Debolina; Mandal, Syamsundar; Roy, Anup; Panda, Chinmay Kumar

    2016-01-01

    The aim of this study is to evaluate chemopreventive and therapeutic efficacy of tea polyphenols epigallocatechin gallete (EGCG) and theaflavin (TF) on self-renewal Wnt and Hedgehog (Hh) pathways during CCl4/N-nitosodiethylamine-induced mouse liver carcinogenesis. For this purpose, the effect of EGCG/TF was investigated in liver lesions of different groups at pre-, continuous and post initiation stages of carcinogenesis. Comparatively increased body weights were evident due to EGCG/TF treatment than carcinogen control mice. Both EGCG and TF could restrict the development of hepatocellular carcinoma at 30th week of carcinogen application showing potential chemoprevention in continuous treated group (mild dysplasia) followed by pretreated (moderate dysplasia) and therapeutic efficacy in posttreated group (mild dysplasia). This restriction was associated with significantly reduced proliferation, increased apoptosis, decreased prevalence of hepatocyte progenitor cell (AFP) and stem cell population (CD44) irrespective of EGCG/TF treatments. The EGCG/TF could modulate the Wnt pathway by reducing β-catenin and phospho-β-catenin-Y-654 expressions along with up-regulation of sFRP1 (secreted frizzled-related protein 1) and adenomatosis polyposis coli during the restriction. In case of the Hh pathway, EGCG/TF could also reduce expressions of glioma-associated oncogene homolog 1 (Gli1) and SMO (smoothened homolog) along with up-regulation of PTCH1 (patched homolog 1). As a result, in Wnt/Hh regulatory pathways decreased expressions of β-catenin/Gli1 target genes like CyclinD1, cMyc and EGFR/phospho-EGFR-Y-1173 and up-regulation of E-cadherin were seen during the restriction. Thus, the restriction of liver carcinogenesis by EGCG/TF was due to reduction in hepatocyte progenitor cell/stem cell population along with modulation of Wnt/Hh and other regulatory pathways. PMID:26386739

  16. Recapitulation of the effects of the human papillomavirus type 16 E7 oncogene on mouse epithelium by somatic Rb deletion and detection of pRb-independent effects of E7 in vivo.

    PubMed

    Balsitis, Scott J; Sage, Julien; Duensing, Stefan; Münger, Karl; Jacks, Tyler; Lambert, Paul F

    2003-12-01

    Although the human papillomavirus (HPV) E7 oncogene is known to contribute to the development of human cervical cancer, the mechanisms of its carcinogenesis are poorly understood. The first identified and most recognized function of E7 is its binding to and inactivation of the retinoblastoma tumor suppressor (pRb), but at least 18 other biological activities have also been reported for E7. Thus, it remains unclear which of these many activities contribute to the oncogenic potential of E7. We used a Cre-lox system to abolish pRb expression in the epidermis of transgenic mice and compared the outcome with the effects of E7 expression in the same tissue at early ages. Mice lacking pRb in epidermis showed epithelial hyperplasia, aberrant DNA synthesis, and improper differentiation. In addition, Rb-deleted epidermis (i.e., epidermis composed of cells with Rb deleted) exhibited centrosomal abnormalities and failed to arrest the cell cycle in response to ionizing radiation. Transgenic mice expressing E7 in skin display the same range of phenotypes. In sum, few differences were detected between Rb-deleted epidermis and E7-expressing epidermis in young mice. However, when both E7 was expressed and Rb was deleted in the same tissue, increased hyperplasia and dysplasia were observed. These findings indicate that inactivation of the Rb pathway can largely account for E7's phenotypes at an early age, but that pRb-independent activities of E7 are detectable in vivo.

  17. Enhancer hijacking activates GFI1 family oncogenes in medulloblastoma

    PubMed Central

    Northcott, Paul A; Lee, Catherine; Zichner, Thomas; Stütz, Adrian M; Erkek, Serap; Kawauchi, Daisuke; Shih, David JH; Hovestadt, Volker; Zapatka, Marc; Sturm, Dominik; Jones, David TW; Kool, Marcel; Remke, Marc; Cavalli, Florence; Zuyderduyn, Scott; Bader, Gary; 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 Deimlmg, 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

    2014-01-01

    Summary Paragraph 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 intertumoural heterogeneity of medulloblastoma, identifying four distinct molecular subgroups. Group 3 and Group 4 subgroup medulloblastomas account for the majority of 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 protooncogenes, GFI1 and GFI1B. Somatic structural variants juxtapose GFI1/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. PMID:25043047

  18. The contrasting oncogenic and tumor suppressor roles of FES.

    PubMed

    Greer, Peter A; Kanda, Shigeru; Smithgall, Thomas E

    2012-01-01

    The FES gene was first discovered as a protein-tyrosine kinase-encoding retroviral oncogene. The ability of v-FES to transform cells in vitro and initiate cancer in vivo has been established by cell culture, engraftment and transgenic mouse studies. The corresponding cellular c-FES proto-oncogene encodes a cytoplasmic FES protein-tyrosine kinase with restrained catalytic activity relative to its retrovirally encoded homologs. These observations have stimulated a search for mutations or inappropriate expression of c-FES in human cancers and research aimed at understanding the functions of the FES kinase and its potential involvement in cancer and other diseases. Paradoxically, although first identified as an oncogene, genetic evidence has also implicated c-fes as a potential tumor suppressor. This review will describe observations from basic and translational research which shapes our current understanding of the physiological, cellular and molecular functions of the FES protein-tyrosine kinase and its potential roles in tumorigenesis. We also propose a model to reconcile the conflicting oncogenic and tumor suppressor roles of c-FES in tumorigenesis.

  19. Induction of MAP kinase phosphatase 3 through Erk/MAP kinase activation in three oncogenic Ras (H-, K- and N-Ras)-expressing NIH/3T3 mouse embryonic fibroblast cell lines

    PubMed Central

    Koo, JaeHyung; Wang, Sen; Kang, NaNa; Hur, Sun Jin; Bahk, Young Yil

    2016-01-01

    Ras oncoproteins are small molecular weight GTPases known for their involvement in oncogenesis, which operate in a complex signaling network with multiple effectors. Approximately 25% of human tumors possess mutations in a member of this family. The Raf1/MEK/Erk1/2 pathway is one of the most intensively studied signaling mechanisms. Different levels of regulation account for the inactivation of MAP kinases by MAPK phosphatases in a cell type- and stimuli-dependent manner. In the present study, using three inducible Ras-expressing NIH/3T3 cell lines, we demonstrated that MKP3 upregulation requires the activation of the Erk1/2 pathway, which correlates with the shutdown of this pathway. We also demonstrated, by applying pharmacological inhibitors and effector mutants of Ras, that induction of MKP3 at the protein level is positively regulated by the oncogenic Ras/Raf/MEK/Erk1/2 signaling pathway. [BMB Reports 2016; 49(7): 370-375] PMID:26818088

  20. Effect of cellular determination on oncogenic transformation by chemicals and oncogenes.

    PubMed Central

    Harrington, M A; Gonzales, F; Jones, P A

    1988-01-01

    Three developmentally determined myogenic cell lines derived from C3H 10T1/2 C18 (10T1/2) mouse embryo cells treated with 5-azacytidine were compared with the parental 10T1/2 line for their susceptibility to oncogenic transformation by 3-methylcholanthrene or the activated human c-Ha-ras oncogene. Neither the 10T1/2 cells nor the myogenic derivatives grew in soft agar or formed tumors in nude mice. In contrast to 10T1/2 cells, the three myogenic derivatives were not susceptible to transformation by 3-methylcholanthrene, so that cellular determination altered the response of 10T1/2 cells to chemical carcinogen. On the other hand, all cell types were transformed to a tumorigenic phenotype following transfection with the activated c-Ha-ras gene. The transfected myogenic cells expressed both the c-Ha-ras gene and the muscle determination gene MyoD1. In contrast to other reports, the presence of as many as six copies of the c-Ha-ras gene per genome did not prevent the formation of striated muscle cells which expressed immunologically detectable muscle-specific myosin. The expression of the c-Ha-ras gene does not therefore necessarily preclude the expression of the determination gene for myogenesis or prevent end-stage myogenic differentiation. Images PMID:2460742

  1. Inhibition of oncogene expression by green tea and (-)-epigallocatechin gallate in mice.

    PubMed

    Hu, G; Han, C; Chen, J

    1995-01-01

    The effects of tea drinking on the tobacco-specific nitrosamine 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK)-induced mouse lung oncogene expression and the effect of topical application of the tea polyphenol component (-)-epigallocatechin-3-gallate (EGCG) on 12-O-tedradecanoylphorbol-13-acetate (TPA)-induced mouse skin oncogene expression were investigated. In the first experiment, mice were treated with NNK (1.3 mg/kg body wt ip) once a day for three days and were given 2% tea in drinking water during the whole experimental period. After four or eight weeks, the lung tissue of the mice treated with NNK displayed a significantly high level of expression in c-myc, c-raf, and c-H-ras oncogenes, and they were all inhibited by tea drinking with inhibitory rates of 50%, 20%, and 50%, respectively. In the second experiment, a single application of 10 nmol of TPA to mouse skin led to a marked increase in the transcripts' level of ornithine decarboxylase (ODC) gene, protein kinase C (PKC) gene, and c-myc oncogene at four hours after TPA administration. Topical application of EGCG (1 or 5 mumol) one hour before the application of TPA inhibited all TPA-induced gene expression in a dose-dependent fashion. These results confirm the anticarcinogenic effects of tea and suggest that a possible mechanism is the effect of tea on carcinogen-induced oncogene expression.

  2. Differential induction of cytolytic susceptibility by E1A, myc, and ras oncogenes in immortalized cells.

    PubMed Central

    Cook, J L; May, D L; Wilson, B A; Walker, T A

    1989-01-01

    The E1A oncogene of adenovirus serotypes 2 and 5 induces susceptibility to the cytolytic effects of natural killer lymphocytes and activated macrophages when expressed in infected and transformed mammalian cells (cytolysis-susceptible phenotype). E1A and the oncogenes v-myc, long-terminal-repeat-promoted c-myc, and activated c-ras share the ability to immortalize transfected low-passage rodent cells. The cytolytic phenotypes of well-characterized rodent cell lines immortalized by these three oncogenes were defined. In contrast to target cells expressing the intact E1A gene, myc- and ras-expressing, immortalized primary transfectants were resistant to lysis by both types of killer cell populations. The same patterns of susceptibility (E1A) and resistance (myc and ras) to cytolysis were observed in oncogene-transfected continuous rat (REF52) and mouse (NIH 3T3) cell lines, indicating that differences in the cytolytic phenotypes associated with expression of these oncogenes are not due to cell selection during immortalization. The results suggest that the E1A oncogene may possess a functional domain that is different from those of other oncogenes, such as myc and ras, and that the activity linked to this postulated domain is dissociable from the process of immortalization. Images PMID:2526229

  3. V-cbl, an oncogene from a dual-recombinant murine retrovirus that induces early B-lineage lymphomas

    SciTech Connect

    Langdon, W.Y.; Klinken, S.P. National Institute of Allergy and Infectious Diseases, Bethesda, MD ); Hartley, J.W.; Morse, H.C. III ); Ruscetti, S.K. )

    1989-02-01

    Cas NS-1 is an acutely transforming murine retrovirus that induces pre-B and pro-B cell lymphomas. Molecular cloning showed it was generated from the ecotropic Cas-Br-M virus by sequential recombinations with endogenous retroviral sequences and a cellular oncogene. The oncogene sequence shows no homology with known oncogenes but some similarity to the yeast transcriptional activator GCN4. A 100-kDa gag-cbl fusion protein, with no detectable kinase activity, is responsible for the cellular transformation. The cellular homologue of v-cbl, present in mouse and human DNA, is expressed in a range of hemopoietic lineages.

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

    SciTech Connect

    Souyri, M.; Vigon, I.; Charon, M.; Tambourin, P. )

    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.

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

    PubMed Central

    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.

    2014-01-01

    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, a single air-liquid interface culture method was used without modification to engineer oncogenic mutations into primary epithelial/mesenchymal organoids from mouse colon, stomach and pancreas. Pancreatic and gastric organoids exhibited dysplasia upon KrasG12D expression and/or p53 loss, and readily generated adenocarcinoma upon in vivo transplantation. In contrast, primary colon organoids required combinatorial Apc, p53, KrasG12D 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), and versus more promiscuous transformation of small intestinal organoids. Colon organoid culture functionally validated the microRNA miR-483 as a dominant driver oncogene at the Insulin-like growth factor-2 (IGF2) 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. PMID:24859528

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

    PubMed

    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.

  7. Arf tumor suppressor promoter monitors latent oncogenic signals in vivo

    NASA Astrophysics Data System (ADS)

    Zindy, Frederique; Williams, Richard T.; Baudino, Troy A.; Rehg, Jerold E.; Skapek, Stephen X.; Cleveland, John L.; Roussel, Martine F.; Sherr, Charles J.

    2003-12-01

    Induction of the Arf tumor suppressor gene by elevated thresholds of mitogenic signals activates a p53-dependent transcriptional response that triggers either growth arrest or apoptosis, thereby countering abnormal cell proliferation. Conversely, Arf inactivation is associated with tumor development. Expression of Arf in tissues of adult mice is difficult to detect, possibly because its induction leads to the arrest or elimination of incipient tumor cells. We replaced coding sequences of exon 1 of the mouse cellular Arf gene with a cDNA encoding GFP, thereby producing Arf-null animals in which GFP expression is driven by the intact Arf promoter. The Arf promoter was induced in several biologic settings previously shown to elicit mouse p19Arf expression. Inactivation of Arf in this manner led to the outgrowth of tumor cells expressing GFP, thereby providing direct evidence that the Arf promoter monitors latent oncogenic signals in vivo.

  8. Oncogenic Brain Metazoan Parasite Infection

    PubMed Central

    Spurgeon, Angela N.; Cress, Marshall C.; Gabor, Oroszi; Ding, Qing-Qing; Miller, Douglas C.

    2013-01-01

    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. PMID:24151568

  9. (Oncogenic action of ionizing radiation)

    SciTech Connect

    Not Available

    1990-01-01

    An extensive experiment involving approximately 400 rats exposed to the neon ion beam at the Bevalac in Berkeley, CA and to electrons is nearing completion. The carcinogenicity of energetic electrons was determined for comparison with the neon ion results. As in past reports we will describe progress in three areas corresponding to the specific aims of the proposal: (1) carcinogenesis and DNA strand breaks in rat skin following exposure by the neon ions or electrons; (2) DNA strand breaks in the epidermis as a function of radiation penetration; (3) oncogene activation in radiation-induced rat skin cancers. 72 refs., 6 tabs.

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

    PubMed Central

    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

  11. Expression of Cellular Oncogenes in Human Malignancies

    NASA Astrophysics Data System (ADS)

    Slamon, Dennis J.; Dekernion, Jean B.; Verma, Inder M.; Cline, Martin J.

    1984-04-01

    Cellular oncogenes have been implicated in the induction of malignant transformation in some model systems in vitro and may be related to malignancies in vivo in some vertebrate species. This article describes a study of the expression of 15 cellular oncogenes in fresh human tumors from 54 patients, representing 20 different tumor types. More than one cellular oncogene was transcriptionally active in all of the tumors examined. In 14 patients it was possible to study normal and malignant tissue from the same organ. In many of these patients, the transcriptional activity of certain oncogenes was greater in the malignant than the normal tissue. The cellular fes (feline sarcoma) oncogene, not previously known to be transcribed in mammalian tissue, was found to be active in lung and hematopoietic malignancies.

  12. TAD disruption as oncogenic driver.

    PubMed

    Valton, Anne-Laure; Dekker, Job

    2016-02-01

    Topologically Associating Domains (TADs) are conserved during evolution and play roles in guiding and constraining long-range regulation of gene expression. Disruption of TAD boundaries results in aberrant gene expression by exposing genes to inappropriate regulatory elements. Recent studies have shown that TAD disruption is often found in cancer cells and contributes to oncogenesis through two mechanisms. One mechanism locally disrupts domains by deleting or mutating a TAD boundary leading to fusion of the two adjacent TADs. The other mechanism involves genomic rearrangements that break up TADs and creates new ones without directly affecting TAD boundaries. Understanding the mechanisms by which TADs form and control long-range chromatin interactions will therefore not only provide insights into the mechanism of gene regulation in general, but will also reveal how genomic rearrangements and mutations in cancer genomes can lead to misregulation of oncogenes and tumor suppressors. PMID:27111891

  13. MYC oncogene in myeloid neoplasias.

    PubMed

    Delgado, M Dolores; Albajar, Marta; Gomez-Casares, M Teresa; Batlle, Ana; León, Javier

    2013-02-01

    MYC is a transcription factor that regulates many critical genes for cell proliferation, differentiation, and biomass accumulation. MYC is one of the most prevalent oncogenes found to be altered in human cancer, being deregulated in about 50 % of tumors. Although MYC deregulation has been more frequently associated to lymphoma and lymphoblastic leukemia than to myeloid malignancies, a body of evidence has been gathered showing that MYC plays a relevant role in malignancies derived from the myeloid compartment. The myeloid leukemogenic activity of MYC has been demonstrated in different murine models. Not surprisingly, MYC has been found to be amplified or/and deregulated in the three major types of myeloid neoplasms: acute myeloid leukemia, myelodysplastic syndromes, and myeloproliferative neoplasms, including chronic myeloid leukemia. Here, we review the recent literature describing the involvement of MYC in myeloid tumors.

  14. Myc oncogenes: the enigmatic family.

    PubMed Central

    Ryan, K M; Birnie, G D

    1996-01-01

    The myc family of proto-oncogenes is believed to be involved in the establishment of many types of human malignancy. The members of this family have been shown to function as transcription factors, and through a designated target sequence bring about continued cell-cycle progression, cellular immortalization and blockages to differentiation in many lineages. However, while much of the recent work focusing on the c-myc oncogene has provided some very important advances, it has also brought to light a large amount of conflicting data as to the mechanism of action of the gene product. In this regard, it has now been shown that c-myc is effective in transcriptional repression as well as transcriptional activation and, perhaps more paradoxically, that it has a role in programmed cell death (apoptosis) as well as in processes of cell-cycle progression. In addition, particular interest has surrounded the distinct roles of the two alternative translation products of the c-myc gene, c-Myc 1 and c-Myc 2. The intriguing observation that the ratio of c-Myc 1 to c-Myc 2 increases markedly upon cellular quiescence led to the discovery that the enforced expression of the two proteins individually showed that c-Myc 2 stimulates cell growth, whereas c-Myc 1 appears to be growth suppressing. Clearly, the disparities in the activities of c-Myc, together with the consistent occurrence of mutations of c-myc in human malignancies, means that, although reaching an understanding of the functions of the myc gene family might not be simple, it remains well worthy of pursuit. PMID:8615760

  15. Cancer induction by restriction of oncogene expression to the stem cell compartment

    PubMed Central

    Pérez-Caro, María; Cobaleda, César; González-Herrero, Inés; Vicente-Dueñas, Carolina; Bermejo-Rodríguez, Camino; Sánchez-Beato, Margarita; Orfao, Alberto; Pintado, Belén; Flores, Teresa; Sánchez-Martín, Manuel; Jiménez, Rafael; Piris, Miguel A; Sánchez-García, Isidro

    2009-01-01

    In human cancers, all cancerous cells carry the oncogenic genetic lesions. However, to elucidate whether cancer is a stem cell-driven tissue, we have developed a strategy to limit oncogene expression to the stem cell compartment in a transgenic mouse setting. Here, we focus on the effects of the BCR-ABLp210 oncogene, associated with chronic myeloid leukaemia (CML) in humans. We show that CML phenotype and biology can be established in mice by restricting BCR-ABLp210 expression to stem cell antigen 1 (Sca1)+ cells. The course of the disease in Sca1-BCR-ABLp210 mice was not modified on STI571 treatment. However, BCR-ABLp210-induced CML is reversible through the unique elimination of the cancer stem cells (CSCs). Overall, our data show that oncogene expression in Sca1+ cells is all that is required to fully reprogramme it, giving rise to a full-blown, oncogene-specified tumour with all its mature cellular diversity, and that elimination of the CSCs is enough to eradicate the whole tumour. PMID:19037256

  16. The HPV-16 E7 oncogene sensitizes malignant cells to IFN-alpha-induced apoptosis

    SciTech Connect

    Wang, Yisong

    2005-10-01

    Interferons (IFNs) exert antitumor effects in several human malignancies, but their mechanism of action is unclear. There is a great variability in sensitivity to IFN treatment depending on both tumor type and the individual patient. The reason for this variable sensitivity is not known. The fact that several IFN-induced anticellular effects are exerted through modulation of proto-oncogenes and tumor suppressor genes may indicate that the malignant genotype may be decisive in the cell's sensitivity to IFN. To determine if a deregulated oncogene could alter the cellular response to IFN, a mouse lymphoma cell line (J3D) was stably transfected with the viral human papillomavirus-16 (HPV-16) E7 oncogene. The E7-transfected cells and their respective mock-transfected sister clones were treated with IFN-{alpha} and examined for possible IFN-induced anticellular effects. We found that the E7-transfected clones were greatly sensitized to IFN-{alpha}-induced apoptosis compared with their mock-transfected counterparts. Induction of apoptosis in the transfected cells correlated with the ability of IFN to activate parts of the proapoptotic machinery specifically in these cells, including activation of caspases and the proapoptotic protein Bak. In summary, our data suggest that transfection of malignant cells with the E7 oncogene can sensitize them to IFN-{alpha}-induced apoptosis. This demonstrates that an oncogenic event may alter the cellular sensitivity to IFN and might also have implications for treatment of HPV related diseases with IFN.

  17. RAS oncogenes: weaving a tumorigenic web

    PubMed Central

    Pylayeva-Gupta, Yuliya; Grabocka, Elda; Bar-Sagi, Dafna

    2013-01-01

    RAS proteins are essential components of signalling pathways that emanate from cell surface receptors. Oncogenic activation of these proteins owing to missense mutations is frequently detected in several types of cancer. A wealth of biochemical and genetic studies indicates that RAS proteins control a complex molecular circuitry that consists of a wide array of interconnecting pathways. In this Review, we describe how RAS oncogenes exploit their extensive signalling reach to affect multiple cellular processes that drive tumorigenesis. PMID:21993244

  18. KIT oncogene inhibition drives intratumoral macrophage M2 polarization

    PubMed Central

    Cavnar, Michael J.; Zeng, Shan; Kim, Teresa S.; Sorenson, Eric C.; Ocuin, Lee M.; Balachandran, Vinod P.; Seifert, Adrian M.; Greer, Jonathan B.; Popow, Rachel; Crawley, Megan H.; Cohen, Noah A.; Green, Benjamin L.; Rossi, Ferdinand; Besmer, Peter; Antonescu, Cristina R.

    2013-01-01

    Tumor-associated macrophages (TAMs) are a major component of the cancer microenvironment. Modulation of TAMs is under intense investigation because they are thought to be nearly always of the M2 subtype, which supports tumor growth. Gastrointestinal stromal tumor (GIST) is the most common human sarcoma and typically results from an activating mutation in the KIT oncogene. Using a spontaneous mouse model of GIST and 57 freshly procured human GISTs, we discovered that TAMs displayed an M1-like phenotype and function at baseline. In both mice and humans, the KIT oncoprotein inhibitor imatinib polarized TAMs to become M2-like, a process which involved TAM interaction with apoptotic tumor cells leading to the induction of CCAAT/enhancer binding protein (C/EBP) transcription factors. In human GISTs that eventually developed resistance to imatinib, TAMs reverted to an M1-like phenotype and had a similar gene expression profile as TAMs from untreated human GISTs. Therefore, TAM polarization depends on tumor cell oncogene activity and has important implications for immunotherapeutic strategies in human cancers. PMID:24323358

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

    PubMed

    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.

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

    PubMed

    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.

  1. REST regulates oncogenic properties of glioblastoma stem cells

    PubMed Central

    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

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

    PubMed

    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.

  3. Oncogenic activation of the human trk proto-oncogene by recombination with the ribosomal large subunit protein L7a.

    PubMed Central

    Ziemiecki, A; Müller, R G; Fu, X C; Hynes, N E; Kozma, S

    1990-01-01

    The trk-2h oncogene, isolated from the human breast carcinoma cell line MDA-MB 231 by genomic DNA-transfection into NIH3T3 cells, consists of the trk proto-oncogene receptor kinase domain fused to a N-terminal 41 amino acid activating sequence (Kozma, S.C., Redmond, S.M.S., Xiao-Chang, F., Saurer, S.M., Groner, B. and Hynes, N.E. (1988) EMBO J., 7, 147-154). Antibodies raised against a bacterially produced beta gal-trk receptor kinase fusion protein recognized a 44 kd phosphoprotein phosphorylated on serine, threonine and tyrosine in extracts of trk-2h transformed NIH3T3 cells. In vitro, in the presence of Mn2+/gamma ATP, this protein became phosphorylated extensively on tyrosine. Cells transformed by trk-2h did not, however, show an elevation in total phosphotyrosine. We have cloned and sequenced the cDNA encoding the amino terminal activating sequences of trk-2h (Kozma et al., 1988). The encoded protein has a high basic amino acid content and the gene is expressed as an abundant 1.2 kb mRNA in human, rat and mouse cells. Antipeptide antibodies raised against a C-terminal peptide recognized specifically a 30 kd protein on Western blots of human, rat and mouse cell extracts. Immunofluorescence revealed, in addition to granular cytoplasmic fluorescence, intense nucleolar staining. The high basic amino acid content and nucleolar staining prompted us to investigate whether the 30 kd protein could be a ribosomal protein. Western immunoblotting analysis of 2D-electrophoretically resolved ribosomal proteins indicated that the 30 kd protein is the ribosomal large subunit protein L7a.(ABSTRACT TRUNCATED AT 250 WORDS) Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 9. PMID:2403926

  4. Human genome: proto-oncogenes and proretroviruses.

    PubMed

    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.

  5. Mouse mammary tumor biology: a short history.

    PubMed

    Cardiff, Robert D; Kenney, Nicholas

    2007-01-01

    For over a century, mouse mammary tumor biology and the associated Mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology, and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration, in 1984, that the mouse mammary gland could be molecularly targeted and used to test the oncogenicity of candidate human genes. Now, very few scientists can avoid using a mouse model to test the biology of their favorite gene. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skills to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this short history of mouse mammary tumor biology is to provide a historical perspective for the benefit of the newcomers. If Einstein was correct in that "we stand on the shoulders of giants," the neophytes should meet their giants.

  6. INO80 governs superenhancer-mediated oncogenic transcription and tumor growth in melanoma.

    PubMed

    Zhou, Bingying; Wang, Li; Zhang, Shu; Bennett, Brian D; He, Fan; Zhang, Yan; Xiong, Chengliang; Han, Leng; Diao, Lixia; Li, Pishun; Fargo, David C; Cox, Adrienne D; Hu, Guang

    2016-06-15

    Superenhancers (SEs) are large genomic regions with a high density of enhancer marks. In cancer, SEs are found near oncogenes and dictate cancer gene expression. However, how oncogenic SEs are regulated remains poorly understood. Here, we show that INO80, a chromatin remodeling complex, is required for SE-mediated oncogenic transcription and tumor growth in melanoma. The expression of Ino80, the SWI/SNF ATPase, is elevated in melanoma cells and patient melanomas compared with normal melanocytes and benign nevi. Furthermore, Ino80 silencing selectively inhibits melanoma cell proliferation, anchorage-independent growth, tumorigenesis, and tumor maintenance in mouse xenografts. Mechanistically, Ino80 occupies >90% of SEs, and its occupancy is dependent on transcription factors such as MITF and Sox9. Ino80 binding reduces nucleosome occupancy and facilitates Mediator recruitment, thus promoting oncogenic transcription. Consistently, genes co-occupied by Ino80 and Med1 are selectively expressed in melanomas compared with melanocytes. Together, our results reveal an essential role of INO80-dependent chromatin remodeling in SE function and suggest a novel strategy for disrupting SEs in cancer treatment. PMID:27340176

  7. Recurrent MALAT1-GLI1 oncogenic fusion and GLI1 up-regulation define a subset of plexiform fibromyxoma.

    PubMed

    Spans, Lien; Fletcher, Christopher Dm; Antonescu, Cristina R; Rouquette, Alexandre; Coindre, Jean-Michel; Sciot, Raf; Debiec-Rychter, Maria

    2016-07-01

    Plexiform fibromyxomas are rare neoplasms, being officially recognized as a distinct entity among benign mesenchymal gastric tumours in the 2010 WHO Classification of Tumours of the Digestive System. Characteristically, these tumours have a multinodular/plexiform growth pattern, and histologically contain variably cellular areas of bland myofibroblastic-type spindle cells embedded in an abundant myxoid matrix, rich in capillary-type vessels. As yet, the molecular and/or genetic features of these tumours are unknown. Here we describe a recurrent translocation, t(11;12)(q11;q13), involving the long non-coding gene metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and the gene glioma-associated oncogene homologue 1 (GLI1) in a subgroup of these tumours. The presence of the fusion transcript in our index case was confirmed using polymerase chain reaction (PCR) on genomic DNA, followed by Sanger sequencing. We showed that the truncated GLI1 protein is overexpressed and retains its capacity to transcriptionally activate its target genes. A specific FISH assay was developed to detect the novel MALAT1-GLI1 translocation in formalin-fixed, paraffin-embedded (FFPE) material. This resulted in the identification of two additional cases with this fusion and two cases with polysomy of the GLI1 gene. Finally, immunohistochemistry revealed that the GLI1 protein is exclusively overexpressed in those cases that harbour GLI1/12q13 genomic alterations. In conclusion, overexpression of GLI1 through a recurrent MALAT1-GLI1 translocation or GLI1 up-regulation delineates a pathogenically distinct subgroup of plexiform fibromyxomas with activation of the Sonic Hedgehog signalling pathway. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:27101025

  8. Recurrent MALAT1-GLI1 oncogenic fusion and GLI1 up-regulation define a subset of plexiform fibromyxoma.

    PubMed

    Spans, Lien; Fletcher, Christopher Dm; Antonescu, Cristina R; Rouquette, Alexandre; Coindre, Jean-Michel; Sciot, Raf; Debiec-Rychter, Maria

    2016-07-01

    Plexiform fibromyxomas are rare neoplasms, being officially recognized as a distinct entity among benign mesenchymal gastric tumours in the 2010 WHO Classification of Tumours of the Digestive System. Characteristically, these tumours have a multinodular/plexiform growth pattern, and histologically contain variably cellular areas of bland myofibroblastic-type spindle cells embedded in an abundant myxoid matrix, rich in capillary-type vessels. As yet, the molecular and/or genetic features of these tumours are unknown. Here we describe a recurrent translocation, t(11;12)(q11;q13), involving the long non-coding gene metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and the gene glioma-associated oncogene homologue 1 (GLI1) in a subgroup of these tumours. The presence of the fusion transcript in our index case was confirmed using polymerase chain reaction (PCR) on genomic DNA, followed by Sanger sequencing. We showed that the truncated GLI1 protein is overexpressed and retains its capacity to transcriptionally activate its target genes. A specific FISH assay was developed to detect the novel MALAT1-GLI1 translocation in formalin-fixed, paraffin-embedded (FFPE) material. This resulted in the identification of two additional cases with this fusion and two cases with polysomy of the GLI1 gene. Finally, immunohistochemistry revealed that the GLI1 protein is exclusively overexpressed in those cases that harbour GLI1/12q13 genomic alterations. In conclusion, overexpression of GLI1 through a recurrent MALAT1-GLI1 translocation or GLI1 up-regulation delineates a pathogenically distinct subgroup of plexiform fibromyxomas with activation of the Sonic Hedgehog signalling pathway. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  9. Dimerize RACK1 upon transformation with oncogenic ras

    SciTech Connect

    Chu, L.-Y.; Chen, Y.-H.; Chuang, N.-N. . E-mail: zonnc@sinica.edu.tw

    2005-05-06

    From our previous studies, we learned that syndecan-2/p120-GAP complex provided docking site for Src to prosecute tyrosine kinase activity upon transformation with oncogenic ras. And, RACK1 protein was reactive with syndecan-2 to keep Src inactivated, but not when Ras was overexpressed. In the present study, we characterized the reaction between RACK1 protein and Ras. RACK1 was isolated from BALB/3T3 cells transfected with plasmids pcDNA3.1-[S-ras(Q{sub 61}K)] of shrimp Penaeus japonicus and RACK1 was revealed to react with GTP-K{sub B}-Ras(Q{sub 61}K), not GDP-K{sub B}-Ras(Q{sub 61}K). This selective interaction between RACK1 and GTP-K{sub B}-Ras(Q{sub 61}K) was further confirmed with RACK1 of human placenta and mouse RACK1-encoded fusion protein. We found that RACK1 was dimerized upon reaction with GTP-K{sub B}-Ras(Q{sub 61}K), as well as with 14-3-3{beta} and geranylgeranyl pyrophosphate, as revealed by phosphorylation with Src tyrosine kinase. We reported the complex of RACK1/GTP-K{sub B}-Ras(Q{sub 61}K) reacted selectively with p120-GAP. This interaction was sufficient to dissemble RACK1 into monomers, a preferred form to compete for the binding of syndecan-2. These data indicate that the reaction of GTP-K{sub B}-Ras(Q{sub 61}K) with RACK1 in dimers may operate a mechanism to deplete RACK1 from reaction with syndecan-2 upon transformation by oncogenic ras and the RACK1/GTP-Ras complex may provide a route to react with p120-GAP and recycle monomeric RACK1 to syndecan-2.

  10. Role of the proto-oncogene Pokemon in cellular transformation and ARF repression.

    PubMed

    Maeda, Takahiro; Hobbs, Robin M; Merghoub, Taha; Guernah, Ilhem; Zelent, Arthur; Cordon-Cardo, Carlos; Teruya-Feldstein, Julie; Pandolfi, Pier Paolo

    2005-01-20

    Aberrant transcriptional repression through chromatin remodelling and histone deacetylation has been postulated to represent a driving force underlying tumorigenesis because histone deacetylase inhibitors have been found to be effective in cancer treatment. However, the molecular mechanisms by which transcriptional derepression would be linked to tumour suppression are poorly understood. Here we identify the transcriptional repressor Pokemon (encoded by the Zbtb7 gene) as a critical factor in oncogenesis. Mouse embryonic fibroblasts lacking Zbtb7 are completely refractory to oncogene-mediated cellular transformation. Conversely, Pokemon overexpression leads to overt oncogenic transformation both in vitro and in vivo in transgenic mice. Pokemon can specifically repress the transcription of the tumour suppressor gene ARF through direct binding. We find that Pokemon is aberrantly overexpressed in human cancers and that its expression levels predict biological behaviour and clinical outcome. Pokemon's critical role in cellular transformation makes it an attractive target for therapeutic intervention. PMID:15662416

  11. Role of the proto-oncogene Pokemon in cellular transformation and ARF repression.

    PubMed

    Maeda, Takahiro; Hobbs, Robin M; Merghoub, Taha; Guernah, Ilhem; Zelent, Arthur; Cordon-Cardo, Carlos; Teruya-Feldstein, Julie; Pandolfi, Pier Paolo

    2005-01-20

    Aberrant transcriptional repression through chromatin remodelling and histone deacetylation has been postulated to represent a driving force underlying tumorigenesis because histone deacetylase inhibitors have been found to be effective in cancer treatment. However, the molecular mechanisms by which transcriptional derepression would be linked to tumour suppression are poorly understood. Here we identify the transcriptional repressor Pokemon (encoded by the Zbtb7 gene) as a critical factor in oncogenesis. Mouse embryonic fibroblasts lacking Zbtb7 are completely refractory to oncogene-mediated cellular transformation. Conversely, Pokemon overexpression leads to overt oncogenic transformation both in vitro and in vivo in transgenic mice. Pokemon can specifically repress the transcription of the tumour suppressor gene ARF through direct binding. We find that Pokemon is aberrantly overexpressed in human cancers and that its expression levels predict biological behaviour and clinical outcome. Pokemon's critical role in cellular transformation makes it an attractive target for therapeutic intervention.

  12. Oncogenic transformation through the cell cycle and the LET dependent inverse dose rate effect

    NASA Technical Reports Server (NTRS)

    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.

  13. Carcinogen-specific mutations in preferred Ras-Raf pathway oncogenes directed by strand bias.

    PubMed

    Keller, Ross R; Gestl, Shelley A; Lu, Amy Q; Hoke, Alicia; Feith, David J; Gunther, Edward J

    2016-08-01

    Carcinogen exposures inscribe mutation patterns on cancer genomes and sometimes bias the acquisition of driver mutations toward preferred oncogenes, potentially dictating sensitivity to targeted agents. Whether and how carcinogen-specific mutation patterns direct activation of preferred oncogenes remains poorly understood. Here, mouse models of breast cancer were exploited to uncover a mechanistic link between strand-biased mutagenesis and oncogene preference. When chemical carcinogens were employed during Wnt1-initiated mammary tumorigenesis, exposure to either 7,12-dimethylbenz(a)anthracene (DMBA) or N-ethyl-N-nitrosourea (ENU) dramatically accelerated tumor onset. Mammary tumors that followed DMBA exposure nearly always activated the Ras pathway via somatic Hras(CAA61CTA) mutations. Surprisingly, mammary tumors that followed ENU exposure typically lacked Hras mutations, and instead activated the Ras pathway downstream via Braf(GTG636GAG) mutations. Hras(CAA61CTA) mutations involve an A-to-T change on the sense strand, whereas Braf(GTG636GAG) mutations involve an inverse T-to-A change, suggesting that strand-biased mutagenesis may determine oncogene preference. To examine this possibility further, we turned to an alternative Wnt-driven tumor model in which carcinogen exposures augment a latent mammary tumor predisposition in Apc(min) mice. DMBA and ENU each accelerated mammary tumor onset in Apc(min) mice by introducing somatic, "second-hit" Apc mutations. Consistent with our strand bias model, DMBA and ENU generated strikingly distinct Apc mutation patterns, including stringently strand-inverse mutation signatures at A:T sites. Crucially, these contrasting signatures precisely match those proposed to confer bias toward Hras(CAA61CTA) versus Braf(GTG636GAG) mutations in the original tumor sets. Our findings highlight a novel mechanism whereby exposure history acts through strand-biased mutagenesis to specify activation of preferred oncogenes. PMID:27207659

  14. In vitro transformation of immature hematopoietic cells by the P210 BCR/ABL oncogene product of the Philadelphia chromosome

    SciTech Connect

    McLaughlin, J.; Chianese, E.; Witte, O.N.

    1987-09-01

    The Philadelphia chromosome is the cytogenetic hallmark of human chronic myelogenous leukemia. RNA splicing joins sequences from a gene on chromosome 22 (BCR) across the translocation breakpoint to a portion of the ABL oncogene from chromosome 9, resulting in a chimeric protein (P210) that is an active tyrosine kinase. Although strongly correlated with this specific human neoplasm, and implicated as an oncogene by analogy to the gene product of the Abelson murine leukemia virus, the P210 gene had not been tested directly for oncogenic potential in hematopoietic cells. The authors have used a retroviral gene-transfer system to express P210 in mouse bone marrow cells. When infected bone marrow is plated under conditions for long-term culture of cells of the B-lymphoid lineage, cells expressing high amounts of P210 tyrosine kinase dominate the culture and rapidly lead to clonal outgrowths of immature lymphoid cells. Expression of P210 is growth-stimulatory but not sufficient for full oncogenic behavior. Some clonal lines progress toward a fully malignant phenotype as judged by increased cloning efficiency in agar suspension and frequency and rapidity of tumor induction in syngeneic mice. Such in vitro systems should be useful in evaluating the sequential and perhaps synergistic involvement of the P210 gene and other oncogenes as models for the progressive changes observed in human chronic myelogenous leukemia.

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

    NASA Technical Reports Server (NTRS)

    Miller, R. C.; Martin, S. G.; Hanson, W. R.; Marino, S. A.; Hall, E. J.; Wachholz, B. W. (Principal Investigator)

    1998-01-01

    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 10T1/2 cell model. The dose-averaged LET for high-energy 56Fe is estimated to be 143 keV/micrometer 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/micrometer 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 10T1/2 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.

  16. Function of oncogenes in cancer development: a changing paradigm

    PubMed Central

    Vicente-Dueñas, Carolina; Romero-Camarero, Isabel; Cobaleda, Cesar; Sánchez-García, Isidro

    2013-01-01

    Tumour-associated oncogenes induce unscheduled proliferation as well as genomic and chromosomal instability. According to current models, therapeutic strategies that block oncogene activity are likely to selectively target tumour cells. However, recent evidences have revealed that oncogenes are only essential for the proliferation of some specific tumour cell types, but not all. Indeed, the latest studies of the interactions between the oncogene and its target cell have shown that oncogenes contribute to cancer development not only by inducing proliferation but also by developmental reprogramming of the epigenome. This provides the first evidence that tumorigenesis can be initiated by stem cell reprogramming, and uncovers a new role for oncogenes in the origin of cancer. Here we analyse these evidences and propose an updated model of oncogene function that can explain the full range of genotype–phenotype associations found in human cancer. Finally, we discuss how this vision opens new avenues for developing novel anti-cancer interventions. PMID:23632857

  17. Identification and Validation of Oncogenes in Liver Cancer Using an Integrative Oncogenomic Approach

    PubMed Central

    Zender, Lars; Spector, Mona S.; Xue, Wen; Flemming, Peer; Cordon-Cardo, Carlos; Silke, John; Fan, Sheung-Tat; Luk, John M.; Wigler, Michael; Hannon, Gregory J.; Mu, David; Lucito, Robert; Powers, Scott; Lowe, Scott W.

    2010-01-01

    SUMMARY The heterogeneity and instability of human tumors hamper straightforward identification of cancer-causing mutations through genomic approaches alone. Herein we describe a mouse model of liver cancer initiated from progenitor cells harboring defined cancer-predisposing lesions. Genome-wide analyses of tumors in this mouse model and in human hepatocellular carcinomas revealed a recurrent amplification at mouse chromosome 9qA1, the syntenic region of human chromosome 11q22. Gene-expression analyses delineated cIAP1, a known inhibitor of apoptosis, and Yap, a transcription factor, as candidate oncogenes in the amplicon. In the genetic context of their amplification, both cIAP1 and Yap accelerated tumorigenesis and were required to sustain rapid growth of amplicon-containing tumors. Furthermore, cIAP1 and Yap cooperated to promote tumorigenesis. Our results establish a tractable model of liver cancer, identify two oncogenes that cooperate by virtue of their coamplification in the same genomic locus, and suggest an efficient strategy for the annotation of human cancer genes. PMID:16814713

  18. Structure of mutant human oncogene protein determined

    SciTech Connect

    Baum, R.

    1989-01-16

    The protein encoded by a mutant human oncogene differs only slightly in structure from the native protein that initiates normal cell division, a finding that may complicate efforts to develop inhibitors of the mutant protein. Previously, the x-ray structure of the protein encoded by the normal c-Ha-ras gene, a protein believed to signal cells to start or stop dividing through its interaction with guanosine triphosphate (GTP), was reported. The structure of the protein encoded by a transforming c-Ha-ras oncogene, in which a valine codon replaces the normal glycine codon at position 12 in the gene, has now been determined. The differences in the structures of the mutant and normal proteins are located primarily in a loop that interacts with the /beta/-phosphate of a bound guanosine diphosphate (GDP) molecule.

  19. Macroautophagy and the Oncogene-Induced Senescence

    PubMed Central

    Grasso, Daniel; Vaccaro, Maria I.

    2014-01-01

    The oncogene-induced senescence is emerging as a potent tumor suppressor mechanism and as a possible therapeutic target. Macroautophagy is intimately linked to the senescence condition setup, although its role has not been elucidated yet. Here, we discuss up-to-date concepts of senescence-related macroautophagy and evaluate the current trend of this growing research field, which has relevance in future perspectives toward therapeutic options against cancer. PMID:25324830

  20. Fumarase tumor suppressor gene and MET oncogene cooperate in upholding transformation and tumorigenesis.

    PubMed

    Costa, Barbara; Dettori, Daniela; Lorenzato, Annalisa; Bardella, Chiara; Coltella, Nadia; Martino, Cosimo; Cammarata, Cristina; Carmeliet, Peter; Olivero, Martina; Di Renzo, Maria Flavia

    2010-08-01

    Loss of the fumarate hydratase (FH) tumor suppressor gene results in the development of benign tumors that rarely, but regrettably, progress to very aggressive cancers. Using mouse embryo fibroblasts (MEFs) to model transformation, we found that fh knockdown results in increased expression of the met oncogene-encoded tyrosine kinase receptor through hypoxia-inducible factor (hif) stabilization. MET-increased expression was alone able to stabilize hif, thus establishing a feed forward loop that might enforce tumor progression. The fh-defective MEFs showed increased motility and protection from apoptosis. Motility, but not survival, relied on hif-1alpha and was greatly enhanced by MET ligand hepatocyte growth factor. Met cooperated with a weakly oncogenic ras in making MEFs transformed and tumorigenic, as shown by in vitro and in vivo assays. Loss of fh was not equally effective by itself but enhanced the transformed and tumorigenic phenotype induced by ras and MET. Consistently, the rescue of fumarase expression abrogated the motogenic and transformed phenotype of fh-defective MEFs. In conclusion, the data suggest that the progression of tumors where FH is lost might be boosted by activation of the MET oncogene, which is able to drive cell-autonomous tumor progression and is a strong candidate for targeted therapy. PMID:20354140

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

    PubMed Central

    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

    2016-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.07101.001 PMID:26956429

  2. Oncogene activation in spontaneous and chemically induced rodent tumors: implications for risk analysis

    SciTech Connect

    Reynolds, S.H.; Stowers, S.J.; Patterson, R.M.; Maronpot, R.R.; Anderson, M.W.

    1988-06-01

    The validity of rodent tumor end points in assessing the potential hazards of chemical exposure to humans is a somewhat controversial but very important issue since most chemicals are classified as potentially hazardous to humans on the basis of long-term carcinogenesis studies in rodents. The ability to distinguish between genotoxic, cytotoxic, or receptor-mediated promotion effects of chemical treatment would aid in the interpretation of rodent carcinogenesis data. Activated oncogenes in spontaneously occurring and chemically induced rodent tumors were examined and compared as one approach to determine the mechanism by which chemical treatment caused an increased incidence of rodent tumors. Different patterns of activated oncogenes were found not only in spontaneous versus chemically induced mouse liver tumors but also in a variety of spontaneous rat tumors versus chemically induced rat lung tumors. In the absence of cytotoxic effects, it could be argued that the chemicals in question activated protooncogenes by a direct genotoxic mechanism. These results provided a basis for the analysis of activated oncogenes in spontaneous and chemically induced rodent tumors to provide information at a molecular level to aid in the extrapolation of rodent carcinogenesis data to human risk assessment.

  3. Oncogene ablation-resistant pancreatic cancer cells depend on mitochondrial function.

    PubMed

    Viale, Andrea; Pettazzoni, Piergiorgio; Lyssiotis, Costas A; Ying, Haoqiang; Sánchez, Nora; Marchesini, Matteo; Carugo, Alessandro; Green, Tessa; Seth, Sahil; Giuliani, Virginia; Kost-Alimova, Maria; Muller, Florian; Colla, Simona; Nezi, Luigi; Genovese, Giannicola; Deem, Angela K; Kapoor, Avnish; Yao, Wantong; Brunetto, Emanuela; Kang, Ya'an; Yuan, Min; Asara, John M; Wang, Y Alan; Heffernan, Timothy P; Kimmelman, Alec C; Wang, Huamin; Fleming, Jason B; Cantley, Lewis C; DePinho, Ronald A; Draetta, Giulio F

    2014-10-30

    Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers in western countries, with a median survival of 6 months and an extremely low percentage of long-term surviving patients. KRAS mutations are known to be a driver event of PDAC, but targeting mutant KRAS has proved challenging. Targeting oncogene-driven signalling pathways is a clinically validated approach for several devastating diseases. Still, despite marked tumour shrinkage, the frequency of relapse indicates that a fraction of tumour cells survives shut down of oncogenic signalling. Here we explore the role of mutant KRAS in PDAC maintenance using a recently developed inducible mouse model of mutated Kras (Kras(G12D), herein KRas) in a p53(LoxP/WT) background. We demonstrate that a subpopulation of dormant tumour cells surviving oncogene ablation (surviving cells) and responsible for tumour relapse has features of cancer stem cells and relies on oxidative phosphorylation for survival. Transcriptomic and metabolic analyses of surviving cells reveal prominent expression of genes governing mitochondrial function, autophagy and lysosome activity, as well as a strong reliance on mitochondrial respiration and a decreased dependence on glycolysis for cellular energetics. Accordingly, surviving cells show high sensitivity to oxidative phosphorylation inhibitors, which can inhibit tumour recurrence. Our integrated analyses illuminate a therapeutic strategy of combined targeting of the KRAS pathway and mitochondrial respiration to manage pancreatic cancer.

  4. The impact of the MYB-NFIB fusion proto-oncogene in vivo

    PubMed Central

    Mikse, Oliver R.; Tchaicha, Jeremy H.; Akbay, Esra A.; Chen, Liang; Bronson, Roderick T.; Hammerman, Peter S.; Wong, Kwok-Kin

    2016-01-01

    Recurrent fusion of the v-myb avian myelobastosis viral oncogene homolog (MYB) and nuclear factor I/B (NFIB) generates the MYB-NFIB transcription factor, which has been detected in a high percentage of individuals with adenoid cystic carcinoma (ACC). To understand the functional role of this fusion protein in carcinogenesis, we generated a conditional mutant transgenic mouse that expresses MYB-NFIB along with p53 mutation in tissues that give rise to ACC: mammary tissue, salivary glands, or systemically in the whole body. Expression of the oncogene in mammary tissue resulted in hyperplastic glands that developed into adenocarcinoma in 27.3% of animals. Systemic expression of the MYB-NFIB fusion caused more rapid development of this breast phenotype, but mice died due to abnormal proliferation in the glomerular compartment of the kidney, which led to development of glomerulonephritis. These findings suggest the MYB-NFIB fusion is oncogenic and treatments targeting this transcription factor may lead to therapeutic responses in ACC patients. PMID:27213588

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

    PubMed

    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.

  6. Oncogenic extracellular vesicles in brain tumor progression.

    PubMed

    D'Asti, Esterina; Garnier, Delphine; Lee, Tae H; Montermini, Laura; Meehan, Brian; Rak, Janusz

    2012-01-01

    The brain is a frequent site of neoplastic growth, including both primary and metastatic tumors. The clinical intractability of many brain tumors 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. Tumor cells produce EVs containing molecular effectors of several cancer-related processes such as growth, invasion, drug resistance, angiogenesis, and coagulopathy. Notably, tumor-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 tumor microenvironment. Examples of transformation-related molecules found in the cargo of tumor-derived EVs include the oncogenic epidermal growth factor receptor (EGFRvIII), tumor suppressors (PTEN), and oncomirs (miR-520g). It is postulated that EVs circulating in blood or cerebrospinal fluid (CSF) of brain tumor patients may be used to decipher molecular features (mutations) of the underlying malignancy, reflect responses to therapy, or molecular subtypes of primary brain tumors [e.g., glioma or medulloblastoma (MB)]. 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. PMID:22934045

  7. Melanoma: oncogenic drivers and the immune system

    PubMed Central

    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

  8. Oncogenic osteomalacia: strange tumours in strange places.

    PubMed Central

    Weiss, D.; Bar, R. S.; Weidner, N.; Wener, M.; Lee, F.

    1985-01-01

    Two patients presented with hypophosphataemic osteomalacia and were subsequently found to have small tumours unusual histopathology and location causing the osteomalacia. Each tumour was found after an intensive search for occult masses. Studies of vitamin D metabolism and renal tubular function before and after surgery yielded further insight into the pathophysiology of oncogenic osteomalacia. These cases demonstrate that microscopic quantities of tumour are capable of causing the syndrome and further illustrate the high index of suspicion often necessary to locate causative tumours in patients with hypophosphataemic osteomalacia. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:4022870

  9. Pro-oncogenic and anti-oncogenic pathways: opportunities and challenges of cancer therapy

    PubMed Central

    Zhang, Jiao; Chen, Yan-Hua; Lu, Qun

    2010-01-01

    Carcinogenesis is the uncontrolled growth of cells gaining the potential to invade and disrupt vital tissue functions. This malignant process includes the occurrence of ‘unwanted’ gene mutations that induce the transformation of normal cells, for example, by overactivation of pro-oncogenic pathways and inactivation of tumor-suppressive or anti-oncogenic pathways. It is now recognized that the number of major signaling pathways that control oncogenesis is not unlimited; therefore, suppressing these pathways can conceivably lead to a cancer cure. However, the clinical application of cancer intervention has not matched up to scientific expectations. Increasing numbers of studies have revealed that many oncogenic-signaling elements show double faces, in which they can promote or suppress cancer pathogenesis depending on tissue type, cancer stage, gene dosage and their interaction with other players in carcinogenesis. This complexity of oncogenic signaling poses challenges to traditional cancer therapy and calls for considerable caution when designing an anticancer drug strategy. We propose future oncology interventions with the concept of integrative cancer therapy. PMID:20373871

  10. The Oncogenic Functions of Nicotinic Acetylcholine Receptors

    PubMed Central

    Zhao, Yue

    2016-01-01

    Nicotinic acetylcholine receptors (nAChRs) are ion channels that are expressed in the cell membrane of all mammalian cells, including cancer cells. Recent findings suggest that nAChRs not only mediate nicotine addiction in the brain but also contribute to the development and progression of cancers directly induced by nicotine and its derived carcinogenic nitrosamines whereas deregulation of the nAChRs is observed in many cancers, and genome-wide association studies (GWAS) indicate that SNPs nAChRs associate with risks of lung cancers and nicotine addiction. Emerging evidences suggest nAChRs are posited at the central regulatory loops of numerous cell growth and prosurvival signal pathways and also mediate the synthesis and release of stimulatory and inhibitory neurotransmitters induced by their agonists. Thus nAChRs mediated cell signaling plays an important role in stimulating the growth and angiogenic and neurogenic factors and mediating oncogenic signal transduction during cancer development in a cell type specific manner. In this review, we provide an integrated view of nAChRs signaling in cancer, heightening on the oncogenic properties of nAChRs that may be targeted for cancer treatment. PMID:26981122

  11. Identification of an Oncogenic RAB Protein

    PubMed Central

    Wheeler, Douglas B.; Zoncu, Roberto; Root, David E.; Sabatini, David M.; Sawyers, Charles L.

    2015-01-01

    In an shRNA screen for genes that affect AKT phosphorylation, we identified the RAB35 small GTPase—a protein previously implicated in endomembrane trafficking—as a new regulator of the PI3K pathway. Depletion of RAB35 suppresses AKT phosphorylation in response to growth factors, whereas expression of a dominant active GTPase-deficient mutant of RAB35 constitutively activates the PI3K/AKT pathway. RAB35 functions downstream of growth factor receptors and upstream of PDK1 and mTORC2 and co-purifies with PI3K in immunoprecipitation assays. Two somatic RAB35 mutations found in human tumors generate alleles that constitutively activate PI3K/AKT signaling, suppress apoptosis, and transform cells in a PI3K-dependent manner. Furthermore, oncogenic RAB35 is sufficient to drive PDGFRα to LAMP2-positive endomembranes in the absence of ligand, suggesting there may be latent oncogenic potential in dysregulated endomembrane trafficking. PMID:26338797

  12. Oncogenic Activation of NF-κB

    PubMed Central

    Staudt, Louis M.

    2010-01-01

    Recent genetic evidence has established a pathogenetic role for NF-κB signaling in cancer. NF-κB signaling is engaged transiently when normal B lymphocytes respond to antigens, but lymphomas derived from these cells accumulate genetic lesions that constitutively activate NF-κB 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 IκB kinase. The activated B-cell-like subtype of diffuse large B-cell lymphoma activates NF-κB 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-κB 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-κB pathways. Various oncogenic abnormalities in epithelial cancers, including mutant K-ras, engage unconventional IκB kinases to activate NF-κB. Inhibition of constitutive NF-κB signaling in each of these cancer types induces apoptosis, providing a rationale for the development of NF-κB pathway inhibitors for the treatment of cancer. PMID:20516126

  13. The Oncogenic Functions of Nicotinic Acetylcholine Receptors.

    PubMed

    Zhao, Yue

    2016-01-01

    Nicotinic acetylcholine receptors (nAChRs) are ion channels that are expressed in the cell membrane of all mammalian cells, including cancer cells. Recent findings suggest that nAChRs not only mediate nicotine addiction in the brain but also contribute to the development and progression of cancers directly induced by nicotine and its derived carcinogenic nitrosamines whereas deregulation of the nAChRs is observed in many cancers, and genome-wide association studies (GWAS) indicate that SNPs nAChRs associate with risks of lung cancers and nicotine addiction. Emerging evidences suggest nAChRs are posited at the central regulatory loops of numerous cell growth and prosurvival signal pathways and also mediate the synthesis and release of stimulatory and inhibitory neurotransmitters induced by their agonists. Thus nAChRs mediated cell signaling plays an important role in stimulating the growth and angiogenic and neurogenic factors and mediating oncogenic signal transduction during cancer development in a cell type specific manner. In this review, we provide an integrated view of nAChRs signaling in cancer, heightening on the oncogenic properties of nAChRs that may be targeted for cancer treatment. PMID:26981122

  14. Identification of an oncogenic RAB protein.

    PubMed

    Wheeler, Douglas B; Zoncu, Roberto; Root, David E; Sabatini, David M; Sawyers, Charles L

    2015-10-01

    In a short hairpin RNA screen for genes that affect AKT phosphorylation, we identified the RAB35 small guanosine triphosphatase (GTPase)-a protein previously implicated in endomembrane trafficking-as a regulator of the phosphatidylinositol 3'-OH kinase (PI3K) pathway. Depletion of RAB35 suppresses AKT phosphorylation in response to growth factors, whereas expression of a dominant active GTPase-deficient mutant of RAB35 constitutively activates the PI3K/AKT pathway. RAB35 functions downstream of growth factor receptors and upstream of PDK1 and mTORC2 and copurifies with PI3K in immunoprecipitation assays. Two somatic RAB35 mutations found in human tumors generate alleles that constitutively activate PI3K/AKT signaling, suppress apoptosis, and transform cells in a PI3K-dependent manner. Furthermore, oncogenic RAB35 is sufficient to drive platelet-derived growth factor receptor α to LAMP2-positive endomembranes in the absence of ligand, suggesting that there may be latent oncogenic potential in dysregulated endomembrane trafficking.

  15. Hedgehog Cholesterolysis: Specialized Gatekeeper to Oncogenic Signaling

    PubMed Central

    Callahan, Brian P.; Wang, Chunyu

    2015-01-01

    Discussions of therapeutic suppression of hedgehog (Hh) signaling almost exclusively focus on receptor antagonism; however, hedgehog’s biosynthesis represents a unique and potentially targetable aspect of this oncogenic signaling pathway. Here, we review a key biosynthetic step called cholesterolysis from the perspectives of structure/function and small molecule inhibition. Cholesterolysis, also called cholesteroylation, generates cholesterol-modified Hh ligand via autoprocessing of a hedgehog precursor protein. Post-translational modification by cholesterol appears to be restricted to proteins in the hedgehog family. The transformation is essential for Hh biological activity and upstream of signaling events. Despite its decisive role in generating ligand, cholesterolysis remains conspicuously unexplored as a therapeutic target. PMID:26473928

  16. The guardians of inherited oncogenic vulnerabilities.

    PubMed

    Arnal, Audrey; Tissot, Tazzio; Ujvari, Beata; Nunney, Leonard; Solary, Eric; Laplane, Lucie; Bonhomme, François; Vittecoq, Marion; Tasiemski, Aurélie; Renaud, François; Pujol, Pascal; Roche, Benjamin; Thomas, Frédéric

    2016-01-01

    Similar to seemingly maladaptive genes in general, the persistence of inherited cancer-causing mutant alleles in populations remains a challenging question for evolutionary biologists. In addition to traditional explanations such as senescence or antagonistic pleiotropy, here we put forward a new hypothesis to explain the retention of oncogenic mutations. We propose that although natural defenses evolve to prevent neoplasm formation and progression thus increasing organismal fitness, they also conceal the effects of cancer-causing mutant alleles on fitness and concomitantly protect inherited ones from purging by purifying selection. We also argue for the importance of the ecological contexts experienced by individuals and/or species. These contexts determine the locally predominant fitness-reducing risks, and hence can aid the prediction of how natural selection will influence cancer outcomes. PMID:26519218

  17. PLAG1 fusion oncogenes in lipoblastoma.

    PubMed

    Hibbard, M K; Kozakewich, H P; Dal Cin, P; Sciot, R; Tan, X; Xiao, S; Fletcher, J A

    2000-09-01

    Lipoblastomas are pediatric neoplasms resulting from transformation of adipocytes. These benign tumors are typically composed of adipose cells in different stages of maturation within a variably myxoid matrix, and they contain clonal rearrangements of chromosome band 8q12. Because lipoblastomas resemble embryonic adipose tissue, characterization of their transforming mechanisms might reveal biological pathways in physiological adipogenesis. Herein, we demonstrate that lipoblastoma chromosome 8q12 rearrangements bring about promoter-swapping events in the PLAG1 oncqgene. We show that the hyaluronic acid synthase 2 (HAS2) or collagen 1 alpha 2 (COL1A2) gene promoter regions are fused to the entire PLAG1 coding sequence in each of four lipoblastomas. PLAG1 is a developmentally regulated zinc finger gene whose tumorigenic function has been shown previously only in epithelial salivary gland cells. Our findings reveal that PLAG1 activation, presumably resulting from transcriptional up-regulation, is a central oncogenic event in lipoblastoma.

  18. Fos family members: regulation, structure and role in oncogenic transformation.

    PubMed

    Tulchinsky, E

    2000-07-01

    The members of the Fos protein family might be subdivided in two groups, according to their ability to transform rodent fibroblasts, transforming (c-Fos and FosB) and non-transforming (Fra-1 and Fra-2) proteins. Members of these groups are differently activated in response to external stimuli and possess different structural features. Importantly, whilst c-Fos and FosB contain multiple transactivation modules in their N- and C-terminal parts, transactivation domains are absent in the non-transforming Fos proteins. As a result, Fra-1 and Fra-2 though efficiently form dimers with the Jun proteins, are weak transcriptional activators and inhibit the c-Fos-dependent activation in transient transfection assay. The numerous experiments performed with the different Fos mutant proteins with impaired transforming ability, as well as with chimeric proteins revealed the importance of the transactivation function for transformation. Fra-1 and Fra-2 proteins albeit ineffectively triggering oncogenic transformation, are abundant in ras- and src-transformed murine and chicken fibroblasts, in neoplastic thyroid cells and in highly malignant mouse adenocarcinoma cells, which underwent mesenchymal transition. The abundance of the non-transforming Fos proteins in these systems might be mediated by a positive AP-l-dependent feedback mechanism, as well as by wnt signals. Furthermore, the manipulation of the Fra-1 expression level in thyroid and mammary tumor cells modulated the transcription of several tumor progression markers and affected cell morphology and invasiveness. These recent data demonstrate a novel function of non-transforming Fos proteins in the maintenance and progression of the transformed state. Interestingly, this function is independent of the documented invalidity of the Fra-1 and Fra-2 proteins as transcriptional activators in rodent fibroblasts.

  19. Novel oncogenic PDGFRA mutations in pediatric high-grade gliomas.

    PubMed

    Paugh, Barbara S; Zhu, Xiaoyan; Qu, Chunxu; Endersby, Raelene; Diaz, Alexander K; Zhang, Junyuan; Bax, Dorine A; Carvalho, Diana; Reis, Rui M; Onar-Thomas, Arzu; Broniscer, Alberto; Wetmore, Cynthia; Zhang, Jinghui; Jones, Chris; Ellison, David W; Baker, Suzanne J

    2013-10-15

    The outcome for children with high-grade gliomas (HGG) remains dismal, with a 2-year survival rate of only 10% to 30%. Diffuse intrinsic pontine glioma (DIPG) comprise a subset of HGG that arise in the brainstem almost exclusively in children. Genome-wide analyses of copy number imbalances previously showed that platelet-derived growth factor receptor α (PDGFRA) is the most frequent target of focal amplification in pediatric HGGs, including DIPGs. To determine whether PDGFRA is also targeted by more subtle mutations missed by copy number analysis, we sequenced all PDGFRA coding exons from a cohort of pediatric HGGs. Somatic-activating mutations were identified in 14.4% (13 of 90) of nonbrainstem pediatric HGGs and 4.7% (2 of 43) of DIPGs, including missense mutations and in-frame deletions and insertions not previously described. Forty percent of tumors with mutation showed concurrent amplification, whereas 60% carried heterozygous mutations. Six different mutations impacting different domains all resulted in ligand-independent receptor activation that was blocked by small molecule inhibitors of PDGFR. Expression of mutants in p53-null primary mouse astrocytes conferred a proliferative advantage in vitro and generated HGGs in vivo with complete penetrance when implanted into brain. The gene expression signatures of these murine HGGs reflected the spectrum of human diffuse HGGs. PDGFRA intragenic deletion of exons 8 and 9 were previously shown in adult HGG, but were not detected in 83 nonbrainstem pediatric HGG and 57 DIPGs. Thus, a distinct spectrum of mutations confers constitutive receptor activation and oncogenic activity to PDGFRα in childhood HGG. PMID:23970477

  20. An Oncogenic Role for Alternative NF-κB Signaling in DLBCL, Revealed Upon Deregulated BCL6 Expression

    PubMed Central

    Zhang, Baochun; Calado, Dinis Pedro; Wang, Zhe; Fröhler, Sebastian; Köchert, Karl; Qian, Yu; Koralov, Sergei B.; Schmidt-Supprian, Marc; Sasaki, Yoshiteru; Unitt, Christine; Rodig, Scott; Chen, Wei; Dalla-Favera, Riccardo; Alt, Frederick W.; Pasqualucci, Laura; Rajewsky, Klaus

    2015-01-01

    Diffuse large B cell lymphoma (DLBCL) is a complex disease comprising diverse subtypes and genetic profiles. Possibly due to 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. PMID:25921526

  1. Activation of ras oncogenes preceding the onset of neoplasia

    SciTech Connect

    Kumar, R.; Barbacid, M. ); Sukumar, S. )

    1990-06-01

    The identification of ras oncogenes in human and animal cancers including precancerous lesions indicates that these genes participate in the early stages of neoplastic development. Yet, these observations do not define the timing of ras oncogene activation in the multistep process of carcinogenesis. To ascertain the timing of ras oncogene activation, an animal model system was devised that involves the induction of mammary carcinomas in rats exposed at birth to the carcinogen nitrosomethylurea. High-resolution restriction fragment length polymorphism analysis of polymerase chain reaction-amplified ras sequences revealed the presence of both H-ras and K-ras oncogenes in normal mammary glands 2 weeks after carcinogen treatment and at least 2 months before the onset of neoplasia. These ras oncogenes can remain latent within the mammary gland until exposure to estrogens, demonstrating that activation of ras oncogenes can precede the onset of neoplasia and suggesting that normal physiological proliferative processes such as estrogen-induced mammary gland development may lead to neoplasia if the targeted cells harbor latent ras oncogenes.

  2. Noncanonical Roles of the Immune System in Eliciting Oncogene Addiction

    PubMed Central

    Casey, Stephanie C.; Bellovin, David I.; Felsher, Dean W.

    2013-01-01

    Summary Cancer is highly complex. The magnitude of this complexity makes it highly surprising that even the brief suppression of an oncogene can sometimes result in rapid and sustained tumor regression illustrating that cancers can be “oncogene addicted” [1-10]. The essential implication is that oncogenes may not only fuel the initiation of tumorigenesis, but in some cases necessarily their surfeit of activation is paramaount to maintain a neoplastic state [11]. Oncogene suppression acutely restores normal physiological programs that effectively overrides secondary genetic events and a cancer collapses [12,13]. Oncogene addiction is mediated both through both tumor intrinsic cell-autonomous mechanisms including proliferative arrest, apoptosis, differentiation and cellular senescence [1,2,4,12] but also host-dependent mechanisms that interact with these tumor intrinsic programs [14,15]. Notably, oncogene inactivation elicits a host immune response that involves specific immune effectors and cytokines that facilitate a remodeling of the tumor microenvironment including the shut down of angiogenesis and the induction of cellular senescence of tumor cells [16]. Hence, immune effectors are critically involved in tumor initiation and prevention [17-19] and progression [20], but also appear to be essential to tumor regression upon oncogene inactivation [21-23]. The understanding how the inactivation of an oncogene elicits a systemic signal in the host that prompts a deconstruction of a tumor could have important implications. The combination of oncogene-targeted therapy together with immunomodulatory therapy may be ideal for the development of both a robust tumor intrinsic as well as immunological effectively leading to sustained tumor regression. PMID:23571026

  3. An integrated approach to dissecting oncogene addiction implicates a Myb-coordinated self-renewal program as essential for leukemia maintenance

    PubMed Central

    Zuber, Johannes; Rappaport, Amy R.; Luo, Weijun; Wang, Eric; Chen, Chong; Vaseva, Angelina V.; Shi, Junwei; Weissmueller, Susann; Fellman, Christof; Taylor, Meredith J.; Weissenboeck, Martina; Graeber, Thomas G.; Kogan, Scott C.; Vakoc, Christopher R.; Lowe, Scott W.

    2011-01-01

    Although human cancers have complex genotypes and are genomically unstable, they often remain dependent on the continued presence of single-driver mutations—a phenomenon dubbed “oncogene addiction.” Such dependencies have been demonstrated in mouse models, where conditional expression systems have revealed that oncogenes able to initiate cancer are often required for tumor maintenance and progression, thus validating the pathways they control as therapeutic targets. Here, we implement an integrative approach that combines genetically defined mouse models, transcriptional profiling, and a novel inducible RNAi platform to characterize cellular programs that underlie addiction to MLL-AF9—a fusion oncoprotein involved in aggressive forms of acute myeloid leukemia (AML). We show that MLL-AF9 contributes to leukemia maintenance by enforcing a Myb-coordinated program of aberrant self-renewal involving genes linked to leukemia stem cell potential and poor prognosis in human AML. Accordingly, partial and transient Myb suppression precisely phenocopies MLL-AF9 withdrawal and eradicates aggressive AML in vivo without preventing normal myelopoiesis, indicating that strategies to inhibit Myb-dependent aberrant self-renewal programs hold promise as effective and cancer-specific therapeutics. Together, our results identify Myb as a critical mediator of oncogene addiction in AML, delineate relevant Myb target genes that are amenable to pharmacologic inhibition, and establish a general approach for dissecting oncogene addiction in vivo. PMID:21828272

  4. Oncogenic ras-driven cancer cell vesiculation leads to emission of double-stranded DNA capable of interacting with target cells

    SciTech Connect

    Lee, Tae Hoon; Chennakrishnaiah, Shilpa; Audemard, Eric; Montermini, Laura; Meehan, Brian; Rak, Janusz

    2014-08-22

    Highlights: • Oncogenic H-ras stimulates emission of extracellular vesicles containing double-stranded DNA. • Vesicle-associated extracellular DNA contains mutant N-ras sequences. • Vesicles mediate intercellular transfer of mutant H-ras DNA to normal fibroblasts where it remains for several weeks. • Fibroblasts exposed to vesicles containing H-ras DNA exhibit increased proliferation. - Abstract: Cell free DNA is often regarded as a source of genetic cancer biomarkers, but the related mechanisms of DNA release, composition and biological activity remain unclear. Here we show that rat epithelial cell transformation by the human H-ras oncogene leads to an increase in production of small, exosomal-like extracellular vesicles by viable cancer cells. These EVs contain chromatin-associated double-stranded DNA fragments covering the entire host genome, including full-length H-ras. Oncogenic N-ras and SV40LT sequences were also found in EVs emitted from spontaneous mouse brain tumor cells. Disruption of acidic sphingomyelinase and the p53/Rb pathway did not block emission of EV-related oncogenic DNA. Exposure of non-transformed RAT-1 cells to EVs containing mutant H-ras DNA led to the uptake and retention of this material for an extended (30 days) but transient period of time, and stimulated cell proliferation. Thus, our study suggests that H-ras-mediated transformation stimulates vesicular emission of this histone-bound oncogene, which may interact with non-transformed cells.

  5. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect

    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.

  6. Oncogenes: The Passport for Viral Oncolysis Through PKR Inhibition

    PubMed Central

    Fernandes, Janaina

    2016-01-01

    The transforming properties of oncogenes are derived from gain-of-function mutations, shifting cell signaling from highly regulated homeostatic to an uncontrolled oncogenic state, with the contribution of the inactivating mutations in tumor suppressor genes P53 and RB, leading to tumor resistance to conventional and target-directed therapy. On the other hand, this scenario fulfills two requirements for oncolytic virus infection in tumor cells: inactivation of tumor suppressors and presence of oncoproteins, also the requirements to engage malignancy. Several of these oncogenes have a negative impact on the main interferon antiviral defense, the double-stranded RNA-activated protein kinase (PKR), which helps viruses to spontaneously target tumor cells instead of normal cells. This review is focused on the negative impact of overexpression of oncogenes on conventional and targeted therapy and their positive impact on viral oncolysis due to their ability to inhibit PKR-induced translation blockage, allowing virion release and cell death. PMID:27486347

  7. Oncogene-dependent apoptosis is mediated by caspase-9

    PubMed Central

    Fearnhead, Howard O.; Rodriguez, Joe; Govek, Eve-Ellen; Guo, Wenjun; Kobayashi, Ryuji; Hannon, Greg; Lazebnik, Yuri A.

    1998-01-01

    Understanding how oncogenic transformation sensitizes cells to apoptosis may provide a strategy to kill tumor cells selectively. We previously developed a cell-free system that recapitulates oncogene dependent apoptosis as reflected by activation of caspases, the core of the apoptotic machinery. Here, we show that this activation requires a previously identified apoptosis-promoting complex consisting of caspase-9, APAF-1, and cytochrome c. As predicted by the in vitro system, preventing caspase-9 activation blocked drug-induced apoptosis in cells sensitized by E1A, an adenoviral oncogene. Oncogenes, such as E1A, appear to facilitate caspase-9 activation by several mechanisms, including the control of cytochrome c release from the mitochondria. PMID:9811857

  8. Oncogenes: The Passport for Viral Oncolysis Through PKR Inhibition.

    PubMed

    Fernandes, Janaina

    2016-01-01

    The transforming properties of oncogenes are derived from gain-of-function mutations, shifting cell signaling from highly regulated homeostatic to an uncontrolled oncogenic state, with the contribution of the inactivating mutations in tumor suppressor genes P53 and RB, leading to tumor resistance to conventional and target-directed therapy. On the other hand, this scenario fulfills two requirements for oncolytic virus infection in tumor cells: inactivation of tumor suppressors and presence of oncoproteins, also the requirements to engage malignancy. Several of these oncogenes have a negative impact on the main interferon antiviral defense, the double-stranded RNA-activated protein kinase (PKR), which helps viruses to spontaneously target tumor cells instead of normal cells. This review is focused on the negative impact of overexpression of oncogenes on conventional and targeted therapy and their positive impact on viral oncolysis due to their ability to inhibit PKR-induced translation blockage, allowing virion release and cell death. PMID:27486347

  9. Silent assassin: oncogenic ras directs epigenetic inactivation of target genes.

    PubMed

    Cheng, Xiaodong

    2008-01-01

    Oncogenic transformation is associated with genetic changes and epigenetic alterations. A study now shows that oncogenic Ras uses a complex and elaborate epigenetic silencing program to specifically repress the expression of multiple unrelated cancer-suppressing genes through a common pathway. These results suggest that cancer-related epigenetic modifications may arise through a specific and instructive mechanism and that genetic changes and epigenetic alterations are intimately connected and contribute to tumorigenesis cooperatively. PMID:18385037

  10. Know thy neighbor: stromal cells can contribute oncogenic signals

    NASA Technical Reports Server (NTRS)

    Tlsty, T. D.; Hein, P. W.

    2001-01-01

    Although the stroma within carcinogenic lesions is known to be supportive and responsive to tumors, new data increasingly show that the stroma also has a more active, oncogenic role in tumorigenesis. Stromal cells and their products can transform adjacent tissues in the absence of pre-existing tumor cells by inciting phenotypic and genomic changes in the epithelial cells. The oncogenic action of distinctive stromal components has been demonstrated through a variety of approaches, which provide clues about the cellular pathways involved.

  11. AID-expressing epithelium is protected from oncogenic transformation by an NKG2D surveillance pathway.

    PubMed

    Pérez-García, Arantxa; Pérez-Durán, Pablo; Wossning, Thomas; Sernandez, Isora V; Mur, Sonia M; Cañamero, Marta; Real, Francisco X; Ramiro, Almudena R

    2015-08-17

    Activation-induced deaminase (AID) initiates secondary antibody diversification in germinal center B cells, giving rise to higher affinity antibodies through somatic hypermutation (SHM) or to isotype-switched antibodies through class switch recombination (CSR). SHM and CSR are triggered by AID-mediated deamination of cytosines in immunoglobulin genes. Importantly, AID activity in B cells is not restricted to Ig loci and can promote mutations and pro-lymphomagenic translocations, establishing a direct oncogenic mechanism for germinal center-derived neoplasias. AID is also expressed in response to inflammatory cues in epithelial cells, raising the possibility that AID mutagenic activity might drive carcinoma development. We directly tested this hypothesis by generating conditional knock-in mouse models for AID overexpression in colon and pancreas epithelium. AID overexpression alone was not sufficient to promote epithelial cell neoplasia in these tissues, in spite of displaying mutagenic and genotoxic activity. Instead, we found that heterologous AID expression in pancreas promotes the expression of NKG2D ligands, the recruitment of CD8(+) T cells, and the induction of epithelial cell death. Our results indicate that AID oncogenic potential in epithelial cells can be neutralized by immunosurveillance protective mechanisms.

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

    PubMed

    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.

  13. AID-expressing epithelium is protected from oncogenic transformation by an NKG2D surveillance pathway

    PubMed Central

    Pérez-García, Arantxa; Pérez-Durán, Pablo; Wossning, Thomas; Sernandez, Isora V; Mur, Sonia M; Cañamero, Marta; Real, Francisco X; Ramiro, Almudena R

    2015-01-01

    Activation-induced deaminase (AID) initiates secondary antibody diversification in germinal center B cells, giving rise to higher affinity antibodies through somatic hypermutation (SHM) or to isotype-switched antibodies through class switch recombination (CSR). SHM and CSR are triggered by AID-mediated deamination of cytosines in immunoglobulin genes. Importantly, AID activity in B cells is not restricted to Ig loci and can promote mutations and pro-lymphomagenic translocations, establishing a direct oncogenic mechanism for germinal center-derived neoplasias. AID is also expressed in response to inflammatory cues in epithelial cells, raising the possibility that AID mutagenic activity might drive carcinoma development. We directly tested this hypothesis by generating conditional knock-in mouse models for AID overexpression in colon and pancreas epithelium. AID overexpression alone was not sufficient to promote epithelial cell neoplasia in these tissues, in spite of displaying mutagenic and genotoxic activity. Instead, we found that heterologous AID expression in pancreas promotes the expression of NKG2D ligands, the recruitment of CD8+ T cells, and the induction of epithelial cell death. Our results indicate that AID oncogenic potential in epithelial cells can be neutralized by immunosurveillance protective mechanisms. PMID:26282919

  14. mTORC1 is a critical mediator of oncogenic Semaphorin3A signaling.

    PubMed

    Yamada, Daisuke; Kawahara, Kohichi; Maeda, Takehiko

    2016-08-01

    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. PMID:27246732

  15. Beyond ALK-RET, ROS1 and other oncogene fusions in lung cancer

    PubMed Central

    Nakaoku, Takashi; Tsuta, Koji; Tsuchihara, Katsuya; Matsumoto, Shingo; Yoh, Kiyotaka; Goto, Koichi

    2015-01-01

    Fusions of the RET and ROS1 protein tyrosine kinase oncogenes with several partner genes were recently identified as new targetable genetic aberrations in cases of non-small cell lung cancer (NSCLC) lacking activating EGFR, KRAS, ALK, BRAF, or HER2 oncogene aberrations. RET and ROS1 fusion-positive tumors are mainly observed in young, female, and/or never smoking patients. Studies based on in vitro and in vivo (i.e., mouse) models and studies of several fusion-positive patients indicate that inhibiting the kinase activity of the RET and ROS1 fusion proteins is a promising therapeutic strategy. Accordingly, there are several ongoing clinical trials aimed at examining the efficacy of tyrosine kinase inhibitors (TKIs) against RET and ROS1 proteins in patients with fusion-positive lung cancer. Other gene fusions (NTRK1, NRG1, and FGFR1/2/3) that are targetable by existing TKIs have also been identified in NSCLCs. Options for personalized lung cancer therapy will be increased with the help of multiplex diagnosis systems able to detect multiple druggable gene fusions. PMID:25870798

  16. AID-expressing epithelium is protected from oncogenic transformation by an NKG2D surveillance pathway.

    PubMed

    Pérez-García, Arantxa; Pérez-Durán, Pablo; Wossning, Thomas; Sernandez, Isora V; Mur, Sonia M; Cañamero, Marta; Real, Francisco X; Ramiro, Almudena R

    2015-10-01

    Activation-induced deaminase (AID) initiates secondary antibody diversification in germinal center B cells, giving rise to higher affinity antibodies through somatic hypermutation (SHM) or to isotype-switched antibodies through class switch recombination (CSR). SHM and CSR are triggered by AID-mediated deamination of cytosines in immunoglobulin genes. Importantly, AID activity in B cells is not restricted to Ig loci and can promote mutations and pro-lymphomagenic translocations, establishing a direct oncogenic mechanism for germinal center-derived neoplasias. AID is also expressed in response to inflammatory cues in epithelial cells, raising the possibility that AID mutagenic activity might drive carcinoma development. We directly tested this hypothesis by generating conditional knock-in mouse models for AID overexpression in colon and pancreas epithelium. AID overexpression alone was not sufficient to promote epithelial cell neoplasia in these tissues, in spite of displaying mutagenic and genotoxic activity. Instead, we found that heterologous AID expression in pancreas promotes the expression of NKG2D ligands, the recruitment of CD8(+) T cells, and the induction of epithelial cell death. Our results indicate that AID oncogenic potential in epithelial cells can be neutralized by immunosurveillance protective mechanisms. PMID:26282919

  17. Activation of ras oncogene in aflatoxin-induced rat liver carcinogenesis.

    PubMed Central

    Sinha, S; Webber, C; Marshall, C J; Knowles, M A; Proctor, A; Barrass, N C; Neal, G E

    1988-01-01

    The presence of activated transforming genes was investigated in four primary aflatoxin-induced rat liver tumors in male Fischer rats, in two cell lines generated from such tumors, in an epithelial liver-derived nontransformed cell line, and in the latter cell line after transformation by aflatoxin B1 in vitro. When DNA extracted from these sources was transfected into NIH 3T3 cells, negative results were obtained from focus assays. Cotransfection of these DNA samples with a gene for resistance to G418, followed by selection for resistance to that antibiotic, and tumorigenicity testing in nude mice demonstrated DNA-mediated transfer of the neoplastic phenotype in all cases except for DNA from the nontransformed cell line. DNA extracted from these primary nude mouse tumors used in a secondary round of transfection with NIH 3T3 cells gave positive results in focus assays, which were conserved through succeeding rounds of transfection. By use of appropriate radiolabeled probes, activated ras oncogenes were detected in all samples. N-ras activation was detected in three of the primary rat liver tumors and both hepatoma cell lines. Ki-ras activation was detected in one primary rat liver tumor, and Ha-ras activation was detected in the cell line transformed in vitro with activated aflatoxin B1. The activated Ki-ras oncogene was further characterized by use of synthetic oligonucleotide probes and was shown to contain a G----A transition at the second nucleotide in codon 12. Images PMID:3287372

  18. Complex Oncogenic Translocations with Gene Amplification are Initiated by Specific DNA Breaks in Lymphocytes

    PubMed Central

    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.

    2009-01-01

    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 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 demonstrate 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 Eμ 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. PMID:19435904

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

    PubMed

    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.

  20. Integrative genome analysis reveals an oncomir/oncogene cluster regulating glioblastoma survivorship.

    PubMed

    Kim, Hyunsoo; Huang, Wei; Jiang, Xiuli; Pennicooke, Brenton; Park, Peter J; Johnson, Mark D

    2010-02-01

    Using a multidimensional genomic data set on glioblastoma from The Cancer Genome Atlas, we identified hsa-miR-26a as a cooperating component of a frequently occurring amplicon that also contains CDK4 and CENTG1, two oncogenes that regulate the RB1 and PI3 kinase/AKT pathways, respectively. By integrating DNA copy number, mRNA, microRNA, and DNA methylation data, we identified functionally relevant targets of miR-26a in glioblastoma, including PTEN, RB1, and MAP3K2/MEKK2. We demonstrate that miR-26a alone can transform cells and it promotes glioblastoma cell growth in vitro and in the mouse brain by decreasing PTEN, RB1, and MAP3K2/MEKK2 protein expression, thereby increasing AKT activation, promoting proliferation, and decreasing c-JUN N-terminal kinase-dependent apoptosis. Overexpression of miR-26a in PTEN-competent and PTEN-deficient glioblastoma cells promoted tumor growth in vivo, and it further increased growth in cells overexpressing CDK4 or CENTG1. Importantly, glioblastoma patients harboring this amplification displayed markedly decreased survival. Thus, hsa-miR-26a, CDK4, and CENTG1 comprise a functionally integrated oncomir/oncogene DNA cluster that promotes aggressiveness in human cancers by cooperatively targeting the RB1, PI3K/AKT, and JNK pathways. PMID:20080666

  1. Amino-acid substitutions at codon 13 of the N-ras oncogene in human acute myeloid leukaemia

    NASA Astrophysics Data System (ADS)

    Bos, Johannes L.; Toksoz, Deniz; Marshall, Christopher J.; Verlaan-de Vries, Matty; Veeneman, Gerrit H.; van der Eb, Alex J.; van Boom, Jacques H.; Janssen, Johannes W. G.; Steenvoorden, Ada C. M.

    1985-06-01

    DNAs from four out of five patients with acute myeloid leukaemia (AML) tested by an in vivo selection assay in nude mice using transfected mouse NIH 3T3 cells were found to contain an activated N-ras oncogene. Using a set of synthetic oligonucleotide probes, we have detected a mutation at codon 13 in all four genes. The same codon is mutated in an additional AML DNA that is positive in the focus-formation assay on 3T3 cells. DNA from the peripheral blood of one patient in remission does not contain a codon 13 mutation.

  2. Inhibition of Ras oncogenic activity by Ras protooncogenes.

    PubMed

    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.

  3. ARF6 Is an Actionable Node that Orchestrates Oncogenic GNAQ Signaling in Uveal Melanoma.

    PubMed

    Yoo, Jae Hyuk; Shi, Dallas S; Grossmann, Allie H; Sorensen, Lise K; Tong, ZongZhong; Mleynek, Tara M; Rogers, Aaron; Zhu, Weiquan; Richards, Jackson R; Winter, Jacob M; Zhu, Jie; Dunn, Christine; Bajji, Ashok; Shenderovich, Mark; Mueller, Alan L; Woodman, Scott E; Harbour, J William; Thomas, Kirk R; Odelberg, Shannon J; Ostanin, Kirill; Li, Dean Y

    2016-06-13

    Activating mutations in Gαq proteins, which form the α subunit of certain heterotrimeric G proteins, drive uveal melanoma oncogenesis by triggering multiple downstream signaling pathways, including PLC/PKC, Rho/Rac, and YAP. Here we show that the small GTPase ARF6 acts as a proximal node of oncogenic Gαq signaling to induce all of these downstream pathways as well as β-catenin signaling. ARF6 activates these diverse pathways through a common mechanism: the trafficking of GNAQ and β-catenin from the plasma membrane to cytoplasmic vesicles and the nucleus, respectively. Blocking ARF6 with a small-molecule inhibitor reduces uveal melanoma cell proliferation and tumorigenesis in a mouse model, confirming the functional relevance of this pathway and suggesting a therapeutic strategy for Gα-mediated diseases. PMID:27265506

  4. Prox1-Heterozygosis Sensitizes the Pancreas to Oncogenic Kras-Induced Neoplastic Transformation12

    PubMed Central

    Drosos, Yiannis; Neale, Geoffrey; Ye, Jianming; Paul, Leena; Kuliyev, Emin; Maitra, Anirban; Means, Anna L; Washington, M Kay; Rehg, Jerold; Finkelstein, David B; Sosa-Pineda, Beatriz

    2016-01-01

    The current paradigm of pancreatic neoplastic transformation proposes an initial step whereby acinar cells convert into acinar-to-ductal metaplasias, followed by progression of these lesions into neoplasias under sustained oncogenic activity and inflammation. Understanding the molecular mechanisms driving these processes is crucial to the early diagnostic and prevention of pancreatic cancer. Emerging evidence indicates that transcription factors that control exocrine pancreatic development could have either, protective or facilitating roles in the formation of preneoplasias and neoplasias in the pancreas. We previously identified that the homeodomain transcription factor Prox1 is a novel regulator of mouse exocrine pancreas development. Here we investigated whether Prox1 function participates in early neoplastic transformation using in vivo, in vitro and in silico approaches. We found that Prox1 expression is transiently re-activated in acinar cells undergoing dedifferentiation and acinar-to-ductal metaplastic conversion. In contrast, Prox1 expression is largely absent in neoplasias and tumors in the pancreas of mice and humans. We also uncovered that Prox1-heterozygosis markedly increases the formation of acinar-to-ductal-metaplasias and early neoplasias, and enhances features associated with inflammation, in mouse pancreatic tissues expressing oncogenic Kras. Furthermore, we discovered that Prox1-heterozygosis increases tissue damage and delays recovery from inflammation in pancreata of mice injected with caerulein. These results are the first demonstration that Prox1 activity protects pancreatic cells from acute tissue damage and early neoplastic transformation. Additional data in our study indicate that this novel role of Prox1 involves suppression of pathways associated with inflammatory responses and cell invasiveness. PMID:26992918

  5. Mouse models for BRAF-induced cancers.

    PubMed

    Pritchard, C; Carragher, L; Aldridge, V; Giblett, S; Jin, H; Foster, C; Andreadi, C; Kamata, T

    2007-11-01

    Oncogenic mutations in the BRAF gene are detected in approximately 7% of human cancer samples with a particularly high frequency of mutation in malignant melanomas. Over 40 different missense BRAF mutations have been found, but the vast majority (>90%) represent a single nucleotide change resulting in a valine-->glutamate mutation at residue 600 ((V600E)BRAF). In cells cultured in vitro, (V600E)BRAF is able to stimulate endogenous MEK [MAPK (mitogen-activated protein kinase)/ERK (extracellular-signal-regulated kinase) kinase] and ERK phosphorylation leading to an increase in cell proliferation, cell survival, transformation, tumorigenicity, invasion and vascular development. Many of these hallmarks of cancer can be reversed by treatment of cells with siRNA (small interfering RNA) to BRAF or by inhibiting MEK, indicating that BRAF and MEK are attractive therapeutic targets in cancer samples with BRAF mutations. In order to fully understand the role of oncogenic BRAF in cancer development in vivo as well as to test the in vivo efficacy of anti-BRAF or anti-MEK therapies, GEMMs (genetically engineered mouse models) have been generated in which expression of oncogenic BRaf is conditionally dependent on the Cre recombinase. The delivery/activation of the Cre recombinase can be regulated in both a temporal and spatial manner and therefore these mouse models can be used to recapitulate the somatic mutation of BRAF that occurs in different tissues in the development of human cancer. The data so far obtained following Cre-mediated activation in haemopoietic tissue and the lung indicate that (V600E)BRAF mutation can drive tumour initiation and that its primary effect is to induce high levels of cyclin D1-mediated cell proliferation. However, hallmarks of OIS (oncogene-induced senescence) are evident that restrain further development of the tumour.

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

    PubMed

    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.

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

    PubMed

    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.

  8. Oncogenes and RNA splicing of human tumor viruses.

    PubMed

    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.

  9. Inhibition of ras oncogene: a novel approach to antineoplastic therapy.

    PubMed

    Scharovsky, O G; Rozados, V R; Gervasoni, S I; Matar, P

    2000-01-01

    The most frequently detected oncogene alterations, both in animal and human cancers, are the mutations in the ras oncogene family. These oncogenes are mutated or overexpressed in many human tumors, with a high incidence in tumors of the pancreas, thyroid, colon, lung and certain types of leukemia. Ras is a small guanine nucleotide binding protein that transduces biological information from the cell surface to cytoplasmic components within cells. The signal is transduced to the cell nucleus through second messengers, and it ultimately induces cell division. Oncogenic forms of p21(ras) lead to unregulated, sustained signaling through downstream effectors. The ras family of oncogenes is involved in the development of both primary tumors and metastases making it a good therapeutic target. Several therapeutic approaches to cancer have been developed pointing to reducing the altered gene product or to eliminating its biological function: (1) gene therapy with ribozymes, which are able to break down specific RNA sequences, or with antisense oligonucleotides, (2) immunotherapy through passive or active immunization protocols, and (3) inhibition of p21(ras) farnesylation either by inhibition of farnesyl transferase or synthesis inhibition of farnesyl moieties. PMID:10895051

  10. Oncogenes and RNA splicing of human tumor viruses.

    PubMed

    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. PMID:26038756

  11. Oncogenes and RNA splicing of human tumor viruses

    PubMed Central

    Ajiro, Masahiko; Zheng, Zhi-Ming

    2014-01-01

    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. PMID:26038756

  12. Oncogenic Ras influences the expression of multiple lncRNAs.

    PubMed

    Kotake, Yojiro; Naemura, Madoka; Kitagawa, Kyoko; Niida, Hiroyuki; Tsunoda, Toshiyuki; Shirasawa, Senji; Kitagawa, Masatoshi

    2016-08-01

    Recent ultrahigh-density tiling array and large-scale transcriptome analysis have revealed that large numbers of long non-coding RNAs (lncRNAs) are transcribed in mammals. Several lncRNAs have been implicated in transcriptional regulation, organization of nuclear structure, and post-transcriptional processing. However, the regulation of expression of lncRNAs is less well understood. Here, we show that the exogenous and endogenous expression of an oncogenic form of small GTPase Ras (called oncogenic Ras) decrease the expression of lncRNA ANRIL (antisense non-coding RNA in the INK4 locus), which is involved in the regulation of cellular senescence. We also show that forced expression of oncogenic Ras increases the expression of lncRNA PANDA (p21 associated ncRNA DNA damage activated), which is involved in the regulation of apoptosis. Microarray analysis demonstrated that expression of multiple lncRNAs fluctuated by forced expression of oncogenic Ras. These findings indicate that oncogenic Ras regulates the expression of a large number of lncRNAs including functional lncRNAs, such as ANRIL and PANDA.

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

    SciTech Connect

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

    2014-01-17

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

  14. Proto-oncogene c-fos expression in growth regions of fetal bone and mesodermal web tissue.

    PubMed

    Dony, C; Gruss, P

    The phylogenic conservation of the proto-oncogene c-fos suggests that this gene product is required for normal metabolic processes. Investigations into the transcription pattern of c-fos in normal tissues and cells have revealed expression during development, differentiation and growth which is dependent to a large extent on external signals transferred by growth factors. The complex pattern of stage and tissue-specific expression has raised the hypothesis that the c-fos gene product might function in the control of either proliferation or differentiation. However, no detailed analysis is yet available concerning the normal expression of c-fos during embryonic and fetal development. Interestingly, recent data derived from studies in transgenic mice reveal that the biological effect of overexpression of exogenous fos is restricted to the developing bone tissue and T-cell development of the mice, perhaps signifying that these cells represent a physiological target tissue of the proto-oncogene fos. Thus, to gain deeper insight into the functional role of the c-fos gene product during physiological processes, it is a requirement to carry out a detailed analysis of the localization and cell-type specificity of c-fos expression in normal mouse embryos. Using the technique of in situ hybridization, we demonstrate here that stage-specific expression of the proto-oncogene c-fos in mouse embryos is restricted to the perichondrial growth regions of the cartilaginous skeleton. Moreover, we found strong c-fos transcription in web-forming mesodermal cells, which are also characterized by a stage-specific high growth capacity. Our results suggest a tissue-specific regulatory role of c-fos during differentiation-dependent growth processes of fetal bone and mesodermal web tissue.

  15. Oncogene addiction: pathways of therapeutic response, resistance, and road maps toward a cure.

    PubMed

    Pagliarini, Raymond; Shao, Wenlin; Sellers, William R

    2015-03-01

    A key goal of cancer therapeutics is to selectively target the genetic lesions that initiate and maintain cancer cell proliferation and survival. While most cancers harbor multiple oncogenic mutations, a wealth of preclinical and clinical data supports that many cancers are sensitive to inhibition of single oncogenes, a concept referred to as 'oncogene addiction'. Herein, we describe the clinical evidence supporting oncogene addiction and discuss common mechanistic themes emerging from the response and acquired resistance to oncogene-targeted therapies. Finally, we suggest several opportunities toward exploiting oncogene addiction to achieve curative cancer therapies.

  16. Oncogene addiction: pathways of therapeutic response, resistance, and road maps toward a cure

    PubMed Central

    Pagliarini, Raymond; Shao, Wenlin; Sellers, William R

    2015-01-01

    A key goal of cancer therapeutics is to selectively target the genetic lesions that initiate and maintain cancer cell proliferation and survival. While most cancers harbor multiple oncogenic mutations, a wealth of preclinical and clinical data supports that many cancers are sensitive to inhibition of single oncogenes, a concept referred to as ‘oncogene addiction’. Herein, we describe the clinical evidence supporting oncogene addiction and discuss common mechanistic themes emerging from the response and acquired resistance to oncogene-targeted therapies. Finally, we suggest several opportunities toward exploiting oncogene addiction to achieve curative cancer therapies. PMID:25680965

  17. Oncogenic kinase fusions: an evolving arena with innovative clinical opportunities

    PubMed Central

    Tabbò, Fabrizio; Pizzi, Marco; Kyriakides, Peter W.; Ruggeri, Bruce; Inghirami, Giorgio

    2016-01-01

    Cancer biology relies on intrinsic and extrinsic deregulated pathways, involving a plethora of intra-cellular and extra-cellular components. Tyrosine kinases are frequently deregulated genes, whose aberrant expression is often caused by major cytogenetic events (e.g. chromosomal translocations). The resulting tyrosine kinase fusions (TKFs) prompt the activation of oncogenic pathways, determining the biological and clinical features of the associated tumors. First reported half a century ago, oncogenic TKFs are now found in a large series of hematologic and solid tumors. The molecular basis of TKFs has been thoroughly investigated and tailored therapies against recurrent TKFs have recently been developed. This review illustrates the biology of oncogenic TKFs and their role in solid as well as hematological malignancies. We also address the therapeutic implications of TKFs and the many open issues concerning their clinical impact. PMID:26943776

  18. Avian oncogenic virus differential diagnosis in chickens using oligonucleotide microarray.

    PubMed

    Wang, Lih-Chiann; Huang, Dean; Pu, Chang-En; Wang, Ching-Ho

    2014-12-15

    Avian oncogenic viruses include the avian leukosis virus (ALV), reticuloendotheliosis virus (REV) and Marek's disease virus (MDV). Multiple oncogenic viral infections are frequently seen, with even Marek's disease vaccines reported to be contaminated with ALV and REV. The gross lesions caused by avian oncogenic viruses often overlap, making differentiation diagnosis based on histopathology difficult. The objective of this study is to develop a rapid approach to simultaneously differentiate, subgroup and pathotype the avian oncogenic viruses. The oligonucleotide microarray was employed in this study. Particular DNA sequences were recognized using specific hybridization between the DNA target and probe on the microarray, followed with colorimetric development through enzyme reaction. With 10 designed probes, ALV-A, ALV-E, ALV-J, REV, MDV pathogenic and vaccine strains were clearly discriminated on the microarray with the naked eyes. The detection limit was 27 copy numbers, which was 10-100 times lower than multiplex PCR. Of 102 field samples screened using the oligonucleotide microarray, 32 samples were positive for ALV-E, 17 samples were positive for ALV-J, 6 samples were positive for REV, 4 samples were positive for MDV, 7 samples were positive for both ALV-A and ALV-E, 5 samples were positive for ALV-A, ALV-E and ALV-J, one sample was positive for both ALV-J and MDV, and 3 samples were positive for both REV and MDV. The oligonucleotide microarray, an easy-to-use, high-specificity, high-sensitivity and extendable assay, presents a potent technique for rapid differential diagnosis of avian oncogenic viruses and the detection of multiple avian oncogenic viral infections under field conditions.

  19. Elimination of B-RAF in Oncogenic C-RAF-expressing Alveolar Epithelial Type II Cells Reduces MAPK Signal Intensity and Lung Tumor Growth*

    PubMed Central

    Zanucco, Emanuele; El-Nikhely, Nefertiti; Götz, Rudolf; Weidmann, Katharina; Pfeiffer, Verena; Savai, Rajkumar; Seeger, Werner; Ullrich, Axel; Rapp, Ulf R.

    2014-01-01

    Tumors are often greatly dependent on signaling cascades promoting cell growth or survival and may become hypersensitive to inactivation of key components within these signaling pathways. Ras and RAF mutations found in human cancer confer constitutive activity to these signaling molecules thereby converting them into an oncogenic state. RAF dimerization is required for normal Ras-dependent RAF activation and is required for the oncogenic potential of mutant RAFs. Here we describe a new mouse model for lung tumor development to investigate the role of B-RAF in oncogenic C-RAF-mediated adenoma initiation and growth. Conditional elimination of B-RAF in C-RAF BxB-expressing embryonic alveolar epithelial type II cells did not block adenoma formation. However, loss of B-RAF led to significantly reduced tumor growth. The diminished tumor growth upon B-RAF inactivation was due to reduced cell proliferation in absence of senescence and increased apoptosis. Furthermore, B-RAF elimination inhibited C-RAF BxB-mediated activation of the mitogenic cascade. In line with these data, mutation of Ser-621 in C-RAF BxB abrogated in vitro the dimerization with B-RAF and blocked the ability to activate the MAPK cascade. Taken together these data indicate that B-RAF is an important factor in oncogenic C-RAF-mediated tumorigenesis. PMID:25096573

  20. Molecular biology of oncogenic inflammatory processes. I. Non-oncogenic and oncogenic pathogens, intrinsic inflammatory reactions without pathogens, and microRNA/DNA interactions (Review).

    PubMed

    Sinkovics, Joseph G

    2012-02-01

    In some inflammasomes tumor cells are generated. The internal environment of the inflammasome is conducive to the induction of malignant transformation. Epigenetic changes initiate this process. The subverted stromal connective tissue cells act to promote and sustain the process of malignant trans-formation. In its early stages, the premalignant cells depend on paracrine circuitries for the reception of growth factors. The ligands are derived from the connective tissue, and the receptors are expressed on the recipient premalignant cells. The initial events are not a direct attack on the proto-oncogenes, and thus it may be entirely reversible. Epigenetic processes of hypermethylation of the genes at the promoters of tumor suppressor genes (to silence them), and deacetylation of the histones aimed at the promoters of proto-oncogenes (to activate them) are on-going. A large number of short RNA sequences (interfering, micro-, short hairpin, non-coding RNAs) silence tumor suppressor genes, by neutralizing their mRNAs. In a serial sequence oncogenes undergo amplifications, point-mutations, translocations and fusions. In its earliest stage, the process is reversible by demethylation of the silenced suppressor gene promoters (to reactivate them), or re-acetylation of the histones of the oncogene promoters, thus de-activating them. The external administration of histone deacetylase inhibitors usually leads to the restoration of histone acetylation. In time, the uncorrected processes solidify into constitutive and irreversible gene mutations. Some of the pathogens inducing inflammations with consquential malignant transformation contain oncogenic gene sequences (papilloma viruses, Epstein-Barr virus, Kaposi's sarcoma-associated herpesvirus, hepatitis B and C viruses, Merkel cell polyoma virus, Helicobacter pylori, enterotoxigenic Bacteroides fragilis). These induced malignancies may be multifocal. Other pathogens are devoid of any known oncogenic genomic sequences

  1. Oncogenic MicroRNAs: Key Players in Malignant Transformation

    PubMed Central

    Frixa, Tania; Donzelli, Sara; Blandino, Giovanni

    2015-01-01

    MicroRNAs (miRNAs) represent a class of non-coding RNAs that exert pivotal roles in the regulation of gene expression at the post-transcriptional level. MiRNAs are involved in many biological processes and slight modulations in their expression have been correlated with the occurrence of different diseases. In particular, alterations in the expression of miRNAs with oncogenic or tumor suppressor functions have been associated with carcinogenesis, malignant transformation, metastasis and response to anticancer treatments. This review will mainly focus on oncogenic miRNAs whose aberrant expression leads to malignancy. PMID:26694467

  2. Avian sarcoma virus 17 carries the jun oncogene.

    PubMed Central

    Maki, Y; Bos, T J; Davis, C; Starbuck, M; Vogt, P K

    1987-01-01

    Biologically active molecular clones of avian sarcoma virus 17 (ASV 17) contain a replication-defective proviral genome of 3.5 kilobases (kb). The genome retains partial gag and env sequences, which flank a cell-derived putative oncogene of 0.93 kb, termed jun. The jun gene lacks preserved coding domains of tyrosine-specific protein kinases. It also shows no significant nucleic acid homology with other known oncogenes. The probable transformation-specific protein in ASV 17-transformed cells is a 55-kDa gag-jun fusion product. Images PMID:3033666

  3. MicroRNA-203 represses selection and expansion of oncogenic Hras transformed tumor initiating cells.

    PubMed

    Riemondy, Kent; Wang, Xiao-jing; Torchia, Enrique C; Roop, Dennis R; Yi, Rui

    2015-07-23

    In many mouse models of skin cancer, only a few tumors typically form even though many cells competent for tumorigenesis receive the same oncogenic stimuli. These observations suggest an active selection process for tumor-initiating cells. Here, we use quantitative mRNA- and miR-Seq to determine the impact of Hras(G12V) on the transcriptome of keratinocytes. We discover that microRNA-203 is downregulated by Hras(G12V). Using a knockout mouse model, we demonstrate that loss of microRNA-203 promotes selection and expansion of tumor-initiating cells. Conversely, restoration of microRNA-203 using an inducible model potently inhibits proliferation of these cells. We comprehensively identify microRNA-203 targets required for Hras-initiated tumorigenesis. These targets include critical regulators of the Ras pathway and essential genes required for cell division. This study establishes a role for the loss of microRNA-203 in promoting selection and expansion of Hras mutated cells and identifies a mechanism through which microRNA-203 antagonizes Hras-mediated tumorigenesis.

  4. MicroRNA-203 represses selection and expansion of oncogenic Hras transformed tumor initiating cells

    PubMed Central

    Riemondy, Kent; Wang, Xiao-jing; Torchia, Enrique C; Roop, Dennis R; Yi, Rui

    2015-01-01

    In many mouse models of skin cancer, only a few tumors typically form even though many cells competent for tumorigenesis receive the same oncogenic stimuli. These observations suggest an active selection process for tumor-initiating cells. Here, we use quantitative mRNA- and miR-Seq to determine the impact of HrasG12V on the transcriptome of keratinocytes. We discover that microRNA-203 is downregulated by HrasG12V. Using a knockout mouse model, we demonstrate that loss of microRNA-203 promotes selection and expansion of tumor-initiating cells. Conversely, restoration of microRNA-203 using an inducible model potently inhibits proliferation of these cells. We comprehensively identify microRNA-203 targets required for Hras-initiated tumorigenesis. These targets include critical regulators of the Ras pathway and essential genes required for cell division. This study establishes a role for the loss of microRNA-203 in promoting selection and expansion of Hras mutated cells and identifies a mechanism through which microRNA-203 antagonizes Hras-mediated tumorigenesis. DOI: http://dx.doi.org/10.7554/eLife.07004.001 PMID:26203562

  5. Mouse homologues of human hereditary disease.

    PubMed Central

    Searle, A G; Edwards, J H; Hall, J G

    1994-01-01

    Details are given of 214 loci known to be associated with human hereditary disease, which have been mapped on both human and mouse chromosomes. Forty two of these have pathological variants in both species; in general the mouse variants are similar in their effects to the corresponding human ones, but exceptions include the Dmd/DMD and Hprt/HPRT mutations which cause little, if any, harm in mice. Possible reasons for phenotypic differences are discussed. In most pathological variants the gene product seems to be absent or greatly reduced in both species. The extensive data on conserved segments between human and mouse chromosomes are used to predict locations in the mouse of over 50 loci of medical interest which are mapped so far only on human chromosomes. In about 80% of these a fairly confident prediction can be made. Some likely homologies between mapped mouse loci and unmapped human ones are also given. Sixty six human and mouse proto-oncogene and growth factor gene homologies are also listed; those of confirmed location are all in known conserved segments. A survey of 18 mapped human disease loci and chromosome regions in which the manifestation or severity of pathological effects is thought to be the result of genomic imprinting shows that most of the homologous regions in the mouse are also associated with imprinting, especially those with homologues on human chromosomes 11p and 15q. Useful methods of accelerating the production of mouse models of human hereditary disease include (1) use of a supermutagen, such as ethylnitrosourea (ENU), (2) targeted mutagenesis involving ES cells, and (3) use of gene transfer techniques, with production of 'knockout mutations'. PMID:8151633

  6. Oncogenic cancer/testis antigens: prime candidates for immunotherapy.

    PubMed

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

    2015-06-30

    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 functions, including support of growth, survival and metastasis. This novel insight into the function of cancer/testis antigens has the potential to deliver more effective cancer vaccines. Moreover, immune targeting of oncogenic cancer/testis antigens in combination with conventional cytotoxic therapies or novel immunotherapies such as checkpoint blockade or adoptive transfer, represents a highly synergistic approach with the potential to improve patient survival.

  7. Oncogenic human papillomaviruses and ploidy in cervical lesions.

    PubMed Central

    Rihet, S; Lorenzato, M; Clavel, C

    1996-01-01

    AIM: To compare ploidy measurements obtained on tissue sections of selected low and high grade squamous intraepithelial lesions containing oncogenic HPV (types 16, 18 or 33) detected by in situ hybridisation (ISH) or PCR. METHODS: DNA ploidy was assessed by image cytometry after Feulgen staining of contiguous serial sections of eight lesions exhibiting atypical squamous cells or squamous atypia and 53 low and 63 high grade squamous intraepithelial lesions in which HPV had been detected by ISH or PCR. RESULTS: Aneuploidy was strongly associated with the presence of oncogenic HPV, being detected in 50% of lesions with squamous atypia and 75.5% of the low and 95.2% of the high grade squamous intraepithelial lesions. The multiploid profile was highly associated with high grade lesions and with the pattern of HPV DNA integration. CONCLUSIONS: The presence of aneuploidy is strongly suggestive of the presence of oncogenic HPV types. Combining the detection of HPV by ISH and PCR with DNA image cytometry may provide the pathologist and the physician with important prognostic information about low grade lesions, especially when these lesions have a multiploid DNA profile and contain oncogenic HPV. PMID:8944607

  8. Complex effects of Ras proto-oncogenes in tumorigenesis.

    PubMed

    Diaz, Roberto; Lopez-Barcons, Lluis; Ahn, Daniel; Garcia-Espana, Antonio; Yoon, Andrew; Matthews, Jeremy; Mangues, Ramon; Perez-Soler, Roman; Pellicer, Angel

    2004-04-01

    Ras proteins have been found mutated in about one-third of human tumors. In vitro, Ras has been shown to regulate distinct and contradictory effects, such as cellular proliferation and apoptosis. Nonetheless, the effects that the wild-type protein elicits in tumorigenesis are poorly understood. Depending on the type of tissue, Ras proto-oncogenes appear to either promote or inhibit the tumor phenotype. In this report, we treated wild-type and N-ras knockout mice with 3-methylcholanthrene (MCA) to induce fibrosarcomas and found that MCA is more carcinogenic in wild-type mice than in knockout mice. After injecting different doses of a tumorigenic cell line, the wild-type mice exhibited a shorter latency of tumor development than the knockouts, indicating that there are N-ras-dependent differences in the stromal cells. Likewise, we have analyzed B-cell lymphomas induced by either N-methylnitrosourea or by the N-ras oncogene in mice that over-express the N-ras proto-oncogene and found that the over-expression of wild-type N-ras is able to increase the incidence of these lymphomas. Considered together, our results indicate that Ras proto-oncogenes can enhance or inhibit the malignant phenotype in vivo in different systems.

  9. Targeting Oncogenic Mutant p53 for Cancer Therapy

    PubMed Central

    Parrales, Alejandro; Iwakuma, Tomoo

    2015-01-01

    Among genetic alterations in human cancers, mutations in the tumor suppressor p53 gene are the most common, occurring in over 50% of human cancers. The majority of p53 mutations are missense mutations and result in the accumulation of dysfunctional p53 protein in tumors. These mutants frequently have oncogenic gain-of-function activities and exacerbate malignant properties of cancer cells, such as metastasis and drug resistance. Increasing evidence reveals that stabilization of mutant p53 in tumors is crucial for its oncogenic activities, while depletion of mutant p53 attenuates malignant properties of cancer cells. Thus, mutant p53 is an attractive druggable target for cancer therapy. Different approaches have been taken to develop small-molecule compounds that specifically target mutant p53. These include compounds that restore wild-type conformation and transcriptional activity of mutant p53, induce depletion of mutant p53, inhibit downstream pathways of oncogenic mutant p53, and induce synthetic lethality to mutant p53. In this review article, we comprehensively discuss the current strategies targeting oncogenic mutant p53 in cancers, with special focus on compounds that restore wild-type p53 transcriptional activity of mutant p53 and those reducing mutant p53 levels. PMID:26732534

  10. Folate levels modulate oncogene-induced replication stress and tumorigenicity

    PubMed Central

    Lamm, Noa; Maoz, Karin; Bester, Assaf C; Im, Michael M; Shewach, Donna S; Karni, Rotem; Kerem, Batsheva

    2015-01-01

    Chromosomal instability in early cancer stages is caused by replication stress. One mechanism by which oncogene expression induces replication stress is to drive cell proliferation with insufficient nucleotide levels. Cancer development is driven by alterations in both genetic and environmental factors. Here, we investigated whether replication stress can be modulated by both genetic and non-genetic factors and whether the extent of replication stress affects the probability of neoplastic transformation. To do so, we studied the effect of folate, a micronutrient that is essential for nucleotide biosynthesis, on oncogene-induced tumorigenicity. We show that folate deficiency by itself leads to replication stress in a concentration-dependent manner. Folate deficiency significantly enhances oncogene-induced replication stress, leading to increased DNA damage and tumorigenicity in vitro. Importantly, oncogene-expressing cells, when grown under folate deficiency, exhibit a significantly increased frequency of tumor development in mice. These findings suggest that replication stress is a quantitative trait affected by both genetic and non-genetic factors and that the extent of replication stress plays an important role in cancer development. PMID:26197802

  11. Notch signaling: switching an oncogene to a tumor suppressor

    PubMed Central

    Lobry, Camille; Oh, Philmo; Mansour, Marc R.; Look, A. Thomas

    2014-01-01

    The Notch signaling pathway is a regulator of self-renewal and differentiation in several tissues and cell types. Notch is a binary cell-fate determinant, and its hyperactivation has been implicated as oncogenic in several cancers including breast cancer and T-cell acute lymphoblastic leukemia (T-ALL). Recently, several studies also unraveled tumor-suppressor roles for Notch signaling in different tissues, including tissues where it was before recognized as an oncogene in specific lineages. Whereas involvement of Notch as an oncogene in several lymphoid malignancies (T-ALL, B-chronic lymphocytic leukemia, splenic marginal zone lymphoma) is well characterized, there is growing evidence involving Notch signaling as a tumor suppressor in myeloid malignancies. It therefore appears that Notch signaling pathway’s oncogenic or tumor-suppressor abilities are highly context dependent. In this review, we summarize and discuss latest advances in the understanding of this dual role in hematopoiesis and the possible consequences for the treatment of hematologic malignancies. PMID:24608975

  12. c-Abl antagonizes the YAP oncogenic function

    PubMed Central

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

    2015-01-01

    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. PMID:25361080

  13. Oncogenic Transformation of Dendritic Cells and Their Precursors Leads to Rapid Cancer Development in Mice.

    PubMed

    Böttcher, Jan P; Zelenay, Santiago; Rogers, Neil C; Helft, Julie; Schraml, Barbara U; Reis e Sousa, Caetano

    2015-11-15

    Dendritic cells (DCs) are powerful APCs that can induce Ag-specific adaptive immune responses and are increasingly recognized as important players in innate immunity to both infection and malignancy. Interestingly, although there are multiple described hematological malignancies, DC cancers are rarely observed in humans. Whether this is linked to the immunogenic potential of DCs, which might render them uniquely susceptible to immune control upon neoplastic transformation, has not been fully investigated. To address the issue, we generated a genetically engineered mouse model in which expression of Cre recombinase driven by the C-type lectin domain family 9, member a (Clec9a) locus causes expression of the Kirsten rat sarcoma viral oncogene homolog (Kras)(G12D) oncogenic driver and deletion of the tumor suppressor p53 within developing and differentiated DCs. We show that these Clec9a(Kras-G12D) mice rapidly succumb from disease and display massive accumulation of transformed DCs in multiple organs. In bone marrow chimeras, the development of DC cancer could be induced by a small number of transformed cells and was not prevented by the presence of untransformed DCs. Notably, activation of transformed DCs did not happen spontaneously but could be induced upon stimulation. Although Clec9a(Kras-G12D) mice showed altered thymic T cell development, peripheral T cells were largely unaffected during DC cancer development. Interestingly, transformed DCs were rejected upon adoptive transfer into wild-type but not lymphocyte-deficient mice, indicating that immunological control of DC cancer is in principle possible but does not occur during spontaneous generation in Clec9a(Kras-G12D) mice. Our findings suggest that neoplastic transformation of DCs does not by default induce anti-cancer immunity and can develop unhindered by immunological barriers. PMID:26459350

  14. The DEK oncogene promotes cellular proliferation through paracrine Wnt signaling in Ron receptor positive breast cancers

    PubMed Central

    Privette Vinnedge, Lisa M.; Benight, Nancy M.; Wagh, Purnima K.; Pease, Nicholas A.; Nashu, Madison A.; Serrano-Lopez, Juana; Adams, Allie K.; Cancelas, Jose A.; Waltz, Susan E.; Wells, Susanne I.

    2014-01-01

    Disease progression and recurrence are major barriers to surviving breast cancer. Understanding the etiology of recurrent or metastatic breast cancer and underlying mechanisms is critical for the development of new treatments and improved survival. Here, we report that two commonly over-expressed breast cancer oncogenes, Ron and DEK, cooperate to promote advanced disease through multi-pronged effects on β-catenin signaling. The Ron receptor is commonly activated in breast cancers, and Ron over-expression in human disease stimulates β-catenin nuclear translocation and is an independent predictor of metastatic dissemination. Dek is a chromatin-associated oncogene whose expression has been linked to cancer through multiple mechanisms, including β-catenin activity. We demonstrate here that Dek is a downstream target of Ron receptor activation in murine and human models. The absence of Dek in the MMTV-Ron mouse model led to a significant delay in tumor development, characterized by decreased cell proliferation, diminished metastasis, and fewer cells expressing cancer stem cell markers. Dek complementation of cell lines established from this model was sufficient to promote cellular growth and invasion in vitro and in vivo. Mechanistically, Dek expression stimulated the production and secretion of Wnt ligands to sustain an autocrine/paracrine canonical β-catenin signaling loop. Finally, we show that Dek over-expression promotes tumorigenic phenotypes in immortalized human mammary epithelial MCF10A cells and, in the context of Ron receptor activation, correlates with disease recurrence and metastasis in patients. Overall, our studies demonstrate that DEK over-expression, due in part to Ron receptor activation, drives breast cancer progression through the induction of Wnt/β-catenin signaling. PMID:24954505

  15. The v-erbB oncogene confers enhanced cellular susceptibility to reovirus infection.

    PubMed

    Strong, J E; Lee, P W

    1996-01-01

    We have previously demonstrated that two mouse cell lines that are poorly infectible by reovirus become highly susceptible upon transfection with the gene encoding the epidermal growth factor receptor (EGFR) (J. E. Strong, D. Tang, and P. W. K. Lee, Virology 197:405-411, 1993). This enhancement of infection efficiency requires a functional EGFR, since such an enhancement is not observed in cells expressing a mutated (kinase-inactive) EGFR. The additional finding that reovirus is capable of directly binding to the N-terminal ectodomain of the EGFR (D. Tang, J. E. Strong, and P. W. K. Lee, Virology 197:412-414, 1993) has led us to question whether this interaction is required for the activation of a signalling cascade that somehow augments the ensuing infection process. In the present study, we address this question, using cells transfected with the v-erbB oncogene, which encodes a protein structurally related to the EGFR but lacking a large portion of the N-terminal ligand-binding domain. The v-erbB protein also possesses ligand-independent, constitutive tyrosine kinase activity. Control NIH 3T3 cells, which are poorly infectible by reovirus (serotype 3, strain Dearing), and NIH 3T3 cells transfected with the v-erbB oncogene (THC-11) were assayed for their susceptibilities to reovirus infection. Infectivity was determined by immunofluorescent detection of viral proteins, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of radiolabeled cells, and plaque titration. All three assays demonstrated a drastically higher degree of susceptibility to infection in the THC-11 cell line. This enhanced susceptibility was found to be abrogated by treatment of the cells with genistein, an inhibitor of tyrosine protein kinases, but only partially by treatment with daidzein, an inactive analog of genistein. We propose that the mechanism of enhancement of infection efficiency conferred by EGFR and v-erbB is through the opportunistic utilization by the virus of an

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

    PubMed

    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

  17. Inhibition of carcinogen induced c-Ha-ras and c-fos proto-oncogenes expression by dietary curcumin

    PubMed Central

    Limtrakul, Porn-ngarm; Anuchapreeda, Songyot; Lipigorngoson, Suwiwek; Dunn, Floyd W

    2001-01-01

    Background We investigated the chemopreventive action of dietary curcumin on 7,12-dimethylbenz(a)anthracene (DMBA)-initiated and 12,0-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor formation in Swiss albino mice. Curcumin, a yellow coloring matter isolated from roots of Curcuma longa Linn, is a phenolic compound possessing antioxidant, free radical scavenger, and antiinflammatory properties. It has been shown by previously reported work that TPA-induced skin tumors were inhibited by topical application of curcumin, and curcumin has been shown to inhibit a variety of biological activities of TPA. Topical application of curcumin was reported to inhibit TPA-induced c-fos, c-jun and c-myc gene expression in mouse skin. This paper reports the effects of orally administered curcumin, which was consumed as a dietary component at concentrations of 0.2 % or 1 %, in ad libitum feeding. Results Animals in which tumors had been initiated with DMBA and promoted with TPA experienced significantly fewer tumors and less tumor volume if they ingested either 0.2% or 1% curcumin diets. Also, the dietary consumption of curcumin resulted in a significantly decreased expression of ras and fos proto-oncogenes in the tumorous skin, as measured by enhanced chemiluminesence Western blotting detection system (Amersham). Conclusions Whereas earlier work demonstrated that topical application of curcumin to mouse skin inhibited TPA-induced expression of c-fos, c-jun and c-myc oncogenes, our results are the first to show that orally consumed curcumin significantly inhibited DMBA- and TPA-induced ras and fos gene expression in mouse skin. PMID:11231886

  18. A Network-Based Model of Oncogenic Collaboration for Prediction of Drug Sensitivity

    PubMed Central

    Laderas, Ted G.; Heiser, Laura M.; Sönmez, Kemal

    2015-01-01

    Tumorigenesis is a multi-step process, involving the acquisition of multiple oncogenic mutations that transform cells, resulting in systemic dysregulation that enables proliferation, invasion, and other cancer hallmarks. The goal of precision medicine is to identify therapeutically-actionable mutations from large-scale omic datasets. However, the multiplicity of oncogenes required for transformation, known as oncogenic collaboration, makes assigning effective treatments difficult. Motivated by this observation, we propose a new type of oncogenic collaboration where mutations in genes that interact with an oncogene may contribute to the oncogene’s deleterious potential, a new genomic feature that we term “surrogate oncogenes.” Surrogate oncogenes are representatives of these mutated subnetworks that interact with oncogenes. By mapping mutations to a protein–protein interaction network, we determine the significance of the observed distribution using permutation-based methods. For a panel of 38 breast cancer cell lines, we identified a significant number of surrogate oncogenes in known oncogenes such as BRCA1 and ESR1, lending credence to this approach. In addition, using Random Forest Classifiers, we show that these significant surrogate oncogenes predict drug sensitivity for 74 drugs in the breast cancer cell lines with a mean error rate of 30.9%. Additionally, we show that surrogate oncogenes are predictive of survival in patients. The surrogate oncogene framework incorporates unique or rare mutations from a single sample, and therefore has the potential to integrate patient-unique mutations into drug sensitivity predictions, suggesting a new direction in precision medicine and drug development. Additionally, we show the prevalence of significant surrogate oncogenes in multiple cancers from The Cancer Genome Atlas, suggesting that surrogate oncogenes may be a useful genomic feature for guiding pancancer analyses and assigning therapies across many tissue

  19. Functional implications of mitochondrial reactive oxygen species generated by oncogenic viruses

    PubMed Central

    Choi, Young Bong; Harhaj, Edward William

    2014-01-01

    Between 15–20% of human cancers are associated with infection by oncogenic viruses. Oncogenic viruses, including HPV, HBV, HCV and HTLV-1, target mitochondria to influence cell proliferation and survival. Oncogenic viral gene products also trigger the production of reactive oxygen species which can elicit oxidative DNA damage and potentiate oncogenic host signaling pathways. Viral oncogenes may also subvert mitochondria quality control mechanisms such as mitophagy and metabolic adaptation pathways to promote virus replication. Here, we will review recent progress on viral regulation of mitophagy and metabolic adaptation and their roles in viral oncogenesis. PMID:25580106

  20. Regulation of oncogene-induced cell cycle exit and senescence by chromatin modifiers

    PubMed Central

    David, Gregory

    2012-01-01

    Oncogene activation leads to dramatic changes in numerous biological pathways controlling cellular division, and results in the initiation of a transcriptional program that promotes transformation. Conversely, it also triggers an irreversible cell cycle exit called cellular senescence, which allows the organism to counteract the potentially detrimental uncontrolled proliferation of damaged cells. Therefore, a tight transcriptional control is required at the onset of oncogenic signal, coordinating both positive and negative regulation of gene expression. Not surprisingly, numerous chromatin modifiers contribute to the cellular response to oncogenic stress. While these chromatin modifiers were initially thought of as mere mediators of the cellular response to oncogenic stress, recent studies have uncovered a direct and specific regulation of chromatin modifiers by oncogenic signals. We review here the diverse functions of chromatin modifiers in the cellular response to oncogenic stress, and discuss the implications of these findings on the regulation of cell cycle progression and proliferation by activated oncogenes. PMID:22825329

  1. Processing, secretion, and biological properties of a novel growth factor of the fibroblast growth factor family with oncogenic potential.

    PubMed Central

    Delli-Bovi, P; Curatola, A M; Newman, K M; Sato, Y; Moscatelli, D; Hewick, R M; Rifkin, D B; Basilico, C

    1988-01-01

    We recently reported that the protein encoded in a novel human oncogene isolated from Kaposi sarcoma DNA was a growth factor with significant homology to basic and acidic fibroblast growth factors (FGFs). To study the properties of this growth factor (referred to as K-FGF) and the mechanism by which the K-fgf oncogene transforms cells, we have studied the production and processing of K-FGF in COS-1 cells transfected with a plasmid encoding the K-fgf cDNA. The results show that, unlike basic and acidic FGFs, the K-FGF protein is cleaved after a signal peptide, glycosylated, and efficiently secreted as a mature protein of 176 or 175 amino acids. Inhibition of glycosylation impaired secretion, and the stability of the secreted K-FGF was greatly enhanced by the presence of heparin in the cultured medium. We have used the conditioned medium from transfected COS-1 cells to test K-FGF biological activity. Similar to basic FGF, the K-FGF protein was mitogenic for fibroblasts and endothelial cells and induced the growth of NIH 3T3 mouse cells in serum-free medium. Accordingly, K-fgf-transformed NIH 3T3 cells grew in serum-free medium, consistent with an autocrine mechanism of growth. We have also expressed the protein encoded in the K-fgf protooncogene in COS-1 cells, and it was indistinguishable in its molecular weight, glycosylation, secretion, and biological activity from K-FGF. Taken together, these results suggest that the mechanism of activation of this oncogene is due to overexpression rather than to mutations in the coding sequences. Images PMID:3043199

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

    SciTech Connect

    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.

  3. SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2

    SciTech Connect

    Park, Sun-Mi; Chae, Myounghee; Kim, Bo-Kyoung; Seo, Taegun; Jang, Ik-Soon; Choi, Jong-Soon; Kim, Il-Chul; Lee, Je-Ho; Park, Junsoo

    2010-01-01

    Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration of adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.

  4. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect

    Burns, F.J.; Garte, S.J.

    1990-01-01

    An extensive experiment involving approximately 400 rats exposed to the neon ion beam at the Bevalac in Berkeley, CA and to electrons is nearing completion. Progress is described in three areas corresponding to the specific aims of the proposal: (1) carcinogenesis and DNA strand breaks in rat skin following exposure by the neon ions or electrons; (2) oncogene activation in radiation-induced rat skin cancers; (3) DNA strand breaks in the epidermis as a function of radiation penetration. 59 refs., 4 tabs.

  5. Oncogenic association of specific human papillomavirus types with cervical neoplasia.

    PubMed

    Lorincz, A T; Temple, G F; Kurman, R J; Jenson, A B; Lancaster, W D

    1987-10-01

    Molecular hybridization analysis of human papillomavirus (HPV) DNA from 190 cervical biopsy specimens from women in the United States, Brazil, and Peru revealed viral sequences in 2 (9%) of 23 biopsy specimens of normal mature squamous epithelium, 7 (44%) of 16 biopsy specimens of metaplastic squamous epithelia, 60 (77%) of 78 cervical intraepithelial neoplasia (CIN), 57 (89%) of 64 invasive squamous carcinomas, and 8 (89%) of 9 endocervical adenocarcinomas. HPV typing by DNA hybridization revealed HPV 6 and HPV 11 sequences in metaplastic squamous epithelia, CIN I, and CIN II, but not in CIN III lesions or invasive carcinomas. HPV 16 was detected in metaplastic epithelium and in nearly half of the invasive squamous carcinomas and adenocarcinomas. It was present in 31% of CIN lesions, increasing in frequency with the severity of CIN from 20% of CIN I to 50% of CIN III. HPV 16 showed a striking difference in geographic distribution, being detected in 36% of the carcinomas from the United States compared to 64% of the carcinomas from Brazil and Peru. HPV 18 was found in metaplastic epithelia and in 17% of carcinomas but in only 1% of CIN lesions. HPV 31 was not found in metaplastic epithelium but was present in 6% of carcinomas and in 18% of CIN lesions. In addition, a group of uncharacterized HPVs, not corresponding to any of the probes used, was found in 5% of normal and metaplastic epithelia and in 18% of CIN and 19% of invasive cancers. These results suggest that individual HPV types that infect the cervix have varying degrees of oncogenic association. HPV 6 and HPV 11 appear to have very little oncogenic association, HPV 31 has low oncogenic association, and HPV 16 and HPV 18 have high oncogenic association. PMID:2821311

  6. Oncogene regulation of tumor suppressor genes in tumorigenesis.

    PubMed

    Sung, Jimmy; Turner, Joel; McCarthy, Susan; Enkemann, Steve; Li, Chan Gong; Yan, Perally; Huang, Timothy; Yeatman, Timothy J

    2005-02-01

    We attempted to demonstrate whether there is an epigenetic link between oncogenes and tumor suppression genes in tumorigenesis. We designed a high throughput model to identify a candidate group of tumor suppressor genes potentially regulated by oncogenes. Gene expression profiling of mock-transfected versus v-src-transfected 3Y1 rat fibroblasts identified significant overexpression of DNA methyltransferase 1, the enzyme responsible for aberrant genome methylation, in v-src-transfected fibroblasts. Secondary microarray analyses identified a number of candidate tumor suppressor genes that were down-regulated by v-src but were also re-expressed following treatment with 5-aza-2'-deoxycytidine, a potent demethylating agent. This candidate group included both tumor suppressor genes that are known to be silenced by DNA hypermethylation and those that have not been previously identified with promoter hypermethylation. To further validate our model, we identified tsg, a tumor suppressor gene that was shown to be down-regulated by v-src and found to harbor dense promoter hypermethylation. Our model demonstrates a cooperative relationship between oncogenes and tumor suppressor genes mediated through promoter hypermethylation.

  7. Targeting Bcl-2 stability to sensitize cells harboring oncogenic ras.

    PubMed

    Peng, Bo; Ganapathy, Suthakar; Shen, Ling; Huang, Junchi; Yi, Bo; Zhou, Xiaodong; Dai, Wei; Chen, Changyan

    2015-09-01

    The pro-survival factor Bcl-2 and its family members are critical determinants of the threshold of the susceptibility of cells to apoptosis. Studies are shown that cells harboring an oncogenic ras were extremely sensitive to the inhibition of protein kinase C (PKC) and Bcl-2 could antagonize this apoptotic process. However, it remains unrevealed how Bcl-2 is being regulated in this apoptotic process. In this study, we investigate the role of Bcl-2 stability in sensitizing the cells harboring oncogenic K-ras to apoptosis triggered by PKC inhibitor GO6976. We demonstrated that Bcl-2 in Swiss3T3 cells ectopically expressing or murine lung cancer LKR cells harboring K-ras rapidly underwent ubiquitin-dependent proteasome pathway after the treatment of GO6976, accompanied with induction of apoptosis. In this process, Bcl-2 formed the complex with Keap-1 and Cul3. The mutation of serine-17 and deletion of BH-2 or 4 was required for Bcl-2 ubiquitination and degradation, which elevate the signal threshold for the induction of apoptosis in the cells following PKC inhibition. Thus, Bcl-2 appears an attractive target for the induction of apoptosis by PKC inhibition in cancer cells expressing oncogenic K-ras. PMID:26041886

  8. Therapeutic opportunities involving cellular oncogenes: novel approaches fostered by biotechnology.

    PubMed

    Huber, B E

    1989-01-01

    Biotechnological processes are having a major impact on many industrial sectors, including the pharmaceutical industry. The contributions of recombinant DNA and hybridoma technologies to modern therapeutics include production of natural and unnatural peptides, subunit vaccines, monoclonal antibodies and nucleic acid hybridization probes for in vitro and in vivo diagnostics and biological imaging, therapeutic monoclonal antibodies as tissue-specific delivery systems or as agents to confer passive immunity, production of therapeutic targets for rational drug design, and the use of cloned enzymes as stereospecific catalysts in large-scale production of small medicinal molecules. Biotechnological advances have led to the identification of a discrete set of genes, oncogenes, which may be essential contributing factors for a great variety and number of human cancers. In addition, biotechnological innovations are fostering the exploitation of oncogenes as novel therapeutic targets for cancer diagnosis, prognosis, and treatment. Because oncogenes are activated in transformation by either qualitative or quantitative mechanisms, however, different biotechnology-based therapeutic approaches are required for each class.

  9. PRG3 induces Ras-dependent oncogenic cooperation in gliomas

    PubMed Central

    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

  10. CRAF R391W is a melanoma driver oncogene

    PubMed Central

    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

  11. KRAS insertion mutations are oncogenic and exhibit distinct functional properties

    PubMed Central

    White, Yasmine; Bagchi, Aditi; Van Ziffle, Jessica; Inguva, Anagha; Bollag, Gideon; Zhang, Chao; Carias, Heidi; Dickens, David; Loh, Mignon; Shannon, Kevin; Firestone, Ari J.

    2016-01-01

    Oncogenic KRAS mutations introduce discrete amino acid substitutions that reduce intrinsic Ras GTPase activity and confer resistance to GTPase-activating proteins (GAPs). Here we discover a partial duplication of the switch 2 domain of K-Ras encoding a tandem repeat of amino acids G60_A66dup in a child with an atypical myeloproliferative neoplasm. K-Ras proteins containing this tandem duplication or a similar five amino acid E62_A66dup mutation identified in lung and colon cancers transform the growth of primary myeloid progenitors and of Ba/F3 cells. Recombinant K-RasG60_A66dup and K-RasE62_A66dup proteins display reduced intrinsic GTP hydrolysis rates, accumulate in the GTP-bound conformation and are resistant to GAP-mediated GTP hydrolysis. Remarkably, K-Ras proteins with switch 2 insertions are impaired for PI3 kinase binding and Akt activation, and are hypersensitive to MEK inhibition. These studies illuminate a new class of oncogenic KRAS mutations and reveal unexpected plasticity in oncogenic Ras proteins that has diagnostic and therapeutic implications. PMID:26854029

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

    SciTech Connect

    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.

  13. Activation of a human c-K-ras oncogene.

    PubMed Central

    Yamamoto, F; Perucho, M

    1984-01-01

    The human lung carcinomas PR310 and PR371 contain activated c-K-ras oncogenes. The oncogene of PR371 was found to present a mutation at codon 12 of the first coding exon which substitutes cysteine for glycine in the encoded p21 protein. We report here that the transforming gene of PR310 tumor contains a mutation in the second coding exon. An A----T transversion at codon 61 results in the incorporation of histidine instead of glutamine in the c-K-ras gene product. By constructing c-K-ras/c-H-ras chimeric genes we show that this point mutation is sufficient to confer transforming potential to ras genes, and that a hybrid ras gene coding for a protein mutant at both codons 12 and 61 is also capable of transforming NIH3T3 cells. The relative transforming potency of p21 proteins encoded by ras genes mutant at codons 12, 61 or both has been analyzed. Our studies also show that the coding exons of ras genes, including the fourth, can be interchanged and the chimeric p21 ras proteins retain their oncogenic ability in normal rodent established cell lines. PMID:6096811

  14. PVT1: a rising star among oncogenic long noncoding RNAs.

    PubMed

    Colombo, Teresa; Farina, Lorenzo; Macino, Giuseppe; Paci, Paola

    2015-01-01

    It is becoming increasingly clear that short and long noncoding RNAs critically participate in the regulation of cell growth, differentiation, and (mis)function. However, while the functional characterization of short non-coding RNAs has been reaching maturity, there is still a paucity of well characterized long noncoding RNAs, even though large studies in recent years are rapidly increasing the number of annotated ones. The long noncoding RNA PVT1 is encoded by a gene that has been long known since it resides in the well-known cancer risk region 8q24. However, a couple of accidental concurrent conditions have slowed down the study of this gene, that is, a preconception on the primacy of the protein-coding over noncoding RNAs and the prevalent interest in its neighbor MYC oncogene. Recent studies have brought PVT1 under the spotlight suggesting interesting models of functioning, such as competing endogenous RNA activity and regulation of protein stability of important oncogenes, primarily of the MYC oncogene. Despite some advancements in modelling the PVT1 role in cancer, there are many questions that remain unanswered concerning the precise molecular mechanisms underlying its functioning. PMID:25883951

  15. PVT1: A Rising Star among Oncogenic Long Noncoding RNAs

    PubMed Central

    Colombo, Teresa; Farina, Lorenzo; Macino, Giuseppe; Paci, Paola

    2015-01-01

    It is becoming increasingly clear that short and long noncoding RNAs critically participate in the regulation of cell growth, differentiation, and (mis)function. However, while the functional characterization of short non-coding RNAs has been reaching maturity, there is still a paucity of well characterized long noncoding RNAs, even though large studies in recent years are rapidly increasing the number of annotated ones. The long noncoding RNA PVT1 is encoded by a gene that has been long known since it resides in the well-known cancer risk region 8q24. However, a couple of accidental concurrent conditions have slowed down the study of this gene, that is, a preconception on the primacy of the protein-coding over noncoding RNAs and the prevalent interest in its neighbor MYC oncogene. Recent studies have brought PVT1 under the spotlight suggesting interesting models of functioning, such as competing endogenous RNA activity and regulation of protein stability of important oncogenes, primarily of the MYC oncogene. Despite some advancements in modelling the PVT1 role in cancer, there are many questions that remain unanswered concerning the precise molecular mechanisms underlying its functioning. PMID:25883951

  16. Utilizing signature-score to identify oncogenic pathways of cholangiocarcinoma

    PubMed Central

    Hsiao, Tzu-Hung; Chen, Hung-I Harry; Lu, Jo-Yang; Lin, Pei-Ying; Keller, Charles; Comerford, Sarah; Tomlinson, Gail E.; Chen, Yidong

    2013-01-01

    Extracting maximal information from gene signature sets (GSSs) via microarray-based transcriptional profiling involves assigning function to up and down regulated genes. Here we present a novel sample scoring method called Signature-score (S-score) which can be used to quantify the expression pattern of tumor samples from previously identified gene signature sets. A simulation result demonstrated an improved accuracy and robustness by S-score method comparing with other scoring methods. By applying the S-score method to cholangiocarcinoma (CAC), an aggressive hepatic cancer that arises from bile ducts cells, we identified enriched oncogenic pathways in two large CAC data sets. Thirteen pathways were enriched in CAC compared with normal liver and bile duct. Moreover, using S-score, we were able to dissect correlations between CAC-associated oncogenic pathways and Gene Ontology function. Two major oncogenic clusters and associated functions were identified. Cluster 1, which included beta-catenin and Ras, showed a positive correlation with the cell cycle, while cluster 2, which included TGF-beta, cytokeratin 19 and EpCAM was inversely correlated with immune function. We also used S-score to identify pathways that are differentially expressed in CAC and hepatocellular carcinoma (HCC), the more common subtype of liver cancer. Our results demonstrate the utility and effectiveness of S-score in assigning functional roles to tumor-associated gene signature sets and in identifying potential therapeutic targets for specific liver cancer subtypes. PMID:23905013

  17. Expression of MALT1 oncogene in hematopoietic stem/progenitor cells recapitulates the pathogenesis of human lymphoma in mice

    PubMed Central

    Vicente-Dueñas, Carolina; Fontán, Lorena; Gonzalez-Herrero, Ines; Romero-Camarero, Isabel; Segura, Victor; Aznar, M. Angela; Alonso-Escudero, Esther; Campos-Sanchez, Elena; Ruiz-Roca, Lucía; Barajas-Diego, Marcos; Sagardoy, Ainara; Martinez-Ferrandis, Jose I.; Abollo-Jimenez, Fernando; Bertolo, Cristina; Peñuelas, Ivan; Garcia-Criado, Francisco J.; García-Cenador, María B.; Tousseyn, Thomas; Agirre, Xabier; Prosper, Felipe; Garcia-Bragado, Federico; McPhail, Ellen D.; Lossos, Izidore S.; Du, Ming-Qing; Flores, Teresa; Hernandez-Rivas, Jesus M.; Gonzalez, Marcos; Salar, Antonio; Bellosillo, Beatriz; Conde, Eulogio; Siebert, Reiner; Sagaert, Xavier; Cobaleda, Cesar; Sanchez-Garcia, Isidro; Martinez-Climent, Jose A.

    2012-01-01

    Chromosomal translocations involving the MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. To date, targeting these translocations to mouse B cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1+Lin− hematopoietic stem/progenitor cells, which showed NF-κB activation and early lymphoid priming, being selectively skewed toward B-cell differentiation. These cells accumulated in extranodal tissues and gave rise to clonal tumors recapitulating the principal clinical, biological, and molecular genetic features of MALT lymphoma. Deletion of p53 gene accelerated tumor onset and induced transformation of MALT lymphoma to activated B-cell diffuse large-cell lymphoma (ABC-DLBCL). Treatment of MALT1-induced lymphomas with a specific inhibitor of MALT1 proteolytic activity decreased cell viability, indicating that endogenous Malt1 signaling was required for tumor cell survival. Our study shows that human-like lymphomas can be modeled in mice by targeting MALT1 expression to hematopoietic stem/progenitor cells, demonstrating the oncogenic role of MALT1 in lymphomagenesis. Furthermore, this work establishes a molecular link between MALT lymphoma and ABC-DLBCL, and provides mouse models to test MALT1 inhibitors. Finally, our results suggest that hematopoietic stem/progenitor cells may be involved in the pathogenesis of human mature B-cell lymphomas. PMID:22689981

  18. Protein kinase A activation inhibits oncogenic Sonic hedgehog signalling and suppresses basal cell carcinoma of the skin.

    PubMed

    Makinodan, Eri; Marneros, Alexander G

    2012-11-01

    Basal cell carcinoma of the skin (BCC) is caused by constitutive activation of the Sonic hedgehog (Shh) pathway, mainly through mutations either in the Shh receptor Patched (PTCH) or in its co-receptor Smoothened (Smo). Inhibitors of this pathway that are currently in clinical trials inhibit Smo. However, mutations in Smo can result in resistance to these inhibitors. To target most BCCs and avoid acquired resistance because of Smo mutations, inhibiting the Shh-pathway downstream of Smo is critical. Attractive downstream targets would be at the level of Gli proteins, the transcriptional activators of this pathway in BCCs. Previously it has been shown that Gli1 and Gli2, when phosphorylated by protein kinase A (PKA), are targeted for proteosomal degradation. Here we show that PKA activation via the cAMP agonist forskolin is sufficient to completely abolish oncogenic Smo activity in vitro. In an inducible BCC mouse model due to a Smo mutation that confers resistance to current Smo inhibitors, topical forskolin treatment significantly reduced Gli1 mRNA levels and resulted in strongly suppressed BCC tumor growth. Our data show that forskolin inhibits the growth of even those BCCs that are resistant to Smo inhibitors and provide a proof-of-principle framework for the development of topically applied human skin-permeable novel pharmacologic inhibitors of oncogenic Shh-signaling through PKA activation. PMID:23163650

  19. Trisomy of the Dscr1 gene suppresses early progression of pancreatic intraepithelial neoplasia driven by oncogenic Kras.

    PubMed

    Lee, Jang Choon; Shin, Jimin; Baek, Kwan-Hyuck

    2013-10-11

    Individuals with Down syndrome exhibit remarkably reduced incidence of most solid tumors including pancreatic cancer. Multiple mechanisms arising from the genetic complexity underlying Down syndrome has been suggested to contribute to such a broad cancer protection. In this study, utilizing a genetically engineered mouse model of pancreatic cancer, we demonstrate that trisomy of the Down syndrome critical region-1 (Dscr1), an endogenous calcineurin inhibitor localized on chromosome 21, suppresses the progression of pancreatic intraepithelial neoplasia-1A (PanIN-1A) to PanIN-1B lesions without affecting the initiation of PanIN lesions mediated by oncogenic Kras(G12D). In addition, we show that Dscr1 trisomy attenuates nuclear localization of nuclear factor of activated T-cells (NFAT) accompanied by upregulation of the p15(Ink4b) tumor suppressor and reduction of cell proliferation in early PanIN lesions. Our data suggest that attenuation of calcineurin-NFAT signaling in neoplastic pancreatic ductal epithelium by a single extra copy of Dscr1 is sufficient to inhibit the progression of early PanIN lesions driven by oncogenic Kras, and thus may be a potential mechanism underlying reduced incidence of pancreatic cancer in Down syndrome individuals. PMID:24041692

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

    PubMed Central

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

    2016-01-01

    Missense mutations in ATM kinase, a master regulator of DNA damage responses, are found in many cancers, but their impact on ATM function and implications for cancer therapy are largely unknown. Here we report that 72% of cancer-associated ATM mutations are missense mutations that are enriched around the kinase domain. Expression of kinase-dead ATM (AtmKD/-) is more oncogenic than loss of ATM (Atm-/-) in mouse models, leading to earlier and more frequent lymphomas with Pten deletions. Kinase-dead ATM protein (Atm-KD), but not loss of ATM (Atm-null), prevents replication-dependent removal of Topo-isomerase I-DNA adducts at the step of strand cleavage, leading to severe genomic instability and hypersensitivity to Topo-isomerase I inhibitors. Correspondingly, Topo-isomerase I inhibitors effectively and preferentially eliminate AtmKD/-, but not Atm-proficientor Atm-/- leukemia in animal models. These findings identify ATM kinase-domain missense mutations as a potent oncogenic event and a biomarker for Topo-isomerase I inhibitor based therapy. DOI: http://dx.doi.org/10.7554/eLife.14709.001 PMID:27304073

  1. The regulation of oncogenic Ras/ERK signalling by dual-specificity mitogen activated protein kinase phosphatases (MKPs).

    PubMed

    Kidger, Andrew M; Keyse, Stephen M

    2016-02-01

    Dual-specificity MAP kinase (MAPK) phosphatases (MKPs or DUSPs) are well-established negative regulators of MAPK signalling in mammalian cells and tissues. By virtue of their differential subcellular localisation and ability to specifically recognise, dephosphorylate and inactivate different MAPK isoforms, they are key spatiotemporal regulators of pathway activity. Furthermore, as they are transcriptionally regulated as downstream targets of MAPK signalling they can either act as classical negative feedback regulators or mediate cross talk between distinct MAPK pathways. Because MAPKs and particularly Ras/ERK signalling are implicated in cancer initiation and development, the observation that MKPs are abnormally regulated in human tumours has been interpreted as evidence that these enzymes can either suppress or promote carcinogenesis. However, definitive evidence of such roles has been lacking. Here we review recent work based on the use of mouse models, biochemical studies and clinical data that demonstrate key roles for MKPs in modulating the oncogenic potential of Ras/ERK signalling and also indicate that these enzymes may play a role in the response of tumours to certain anticancer drugs. Overall, this work reinforces the importance of negative regulatory mechanisms in modulating the activity of oncogenic MAPK signalling and indicates that MKPs may provide novel targets for therapeutic intervention in cancer. PMID:26791049

  2. The impact of chromosomal translocation locus and fusion oncogene coding sequence in synovial sarcomagenesis

    PubMed Central

    Jones, Kevin B.; Barrott, Jared J.; Xie, Mingchao; Haldar, Malay; Jin, Huifeng; Zhu, Ju-Fen; Monument, Michael J.; Mosbruger, Tim L.; Langer, Ellen M.; Randall, R. Lor; Wilson, Richard K.; Cairns, Bradley R.; Ding, Li; Capecchi, Mario R.

    2016-01-01

    Synovial sarcomas are aggressive soft-tissue malignancies that express chromosomal translocation-generated fusion genes, SS18-SSX1 or SS18-SSX2 in most cases. Here, we report a mouse sarcoma model expressing SS18-SSX1, complementing our prior model expressing SS18-SSX2. Exome sequencing identified no recurrent secondary mutations in tumors of either genotype. Most of the few mutations identified in single tumors were present in genes that were minimally or not expressed in any of the tumors. Chromosome 6, either entirely or around the fusion gene expression locus, demonstrated a copy number gain in a majority of tumors of both genotypes. Thus, by fusion oncogene coding sequence alone, SS18-SSX1 and SS18-SSX2 can each drive comparable synovial sarcomagenesis, independent from other genetic drivers. SS18-SSX1 and SS18-SSX2 tumor transcriptomes demonstrated very few consistent differences overall. In direct tumorigenesis comparisons, SS18-SSX2 was slightly more sarcomagenic than SS18-SSX1, but equivalent in its generation of biphasic histologic features. Meta-analysis of human synovial sarcoma patient series identified two tumor-gentoype-phenotype correlations that were not modeled by the mice, namely a scarcity of male hosts and biphasic histologic features among SS18-SSX2 tumors. Re-analysis of human SS18-SSX1 and SS18-SSX2 tumor transcriptomes demonstrated very few consistent differences, but highlighted increased native SSX2 expression in SS18-SSX1 tumors. This suggests that the translocated locus may drive genotype-phenotype differences more than the coding sequence of the fusion gene created. Two possible roles for native SSX2 in synovial sarcomagenesis are explored. Thus even specific partial failures of mouse genetic modeling can be instructive to human tumor biology. PMID:26947017

  3. The Oncogene LRF Stimulates Proliferation of Mesenchymal Stem Cells and Inhibits Their Chondrogenic Differentiation

    PubMed Central

    Li, Huan; Acharya, Chitrangada; Kumari, Ratna; Fierro, Fernando; Haudenschild, Dominik R.; Nolta, Jan; Di Cesare, Paul E.

    2013-01-01

    Objective. The oncogene leukemia/lymphoma-related factor (LRF) enhances chondrosarcoma proliferation and malignancy. This study aimed to investigate the roles of LRF in chondrogenic differentiation of primary human bone marrow–derived mesenchymal stem cells (BMSCs). Design. LRF was overexpressed in BMSC by lentiviral transduction. Chondrogenic differentiation of BMSC was induced by high-density pellet culture. Western blotting and real-time polymerase chain reaction were used to investigate changes in protein and mRNA levels, respectively, during chondrogenesis. Safranin-O staining, immunohistochemistry, and glycoaminoglycan contents were used to assess cartilage matrix deposition. BMSC proliferation was determined by mitochondrial dehydrogenase activity and cell counting. Cell cycle profiling was performed by flow cytometry. Results. LRF overexpression effectively inhibited protein and mRNA expression of chondrocyte markers and cartilage matrix deposition during chondrogenesis of BMSC. Endogenous LRF expression was constitutively high in undifferentiated BMSC but remained low in primary articular chondrocytes. Endogenous LRF protein was downregulated in a time-dependent manner during chondrogenesis. BMSCs overexpressing LRF had higher proliferation rates and cell population in the S phase. LRF suppressed p53 expression during chondrogenesis and this might prevent differentiating chondrocytes from entering a quiescent state. Conclusion. Our data showed that LRF is important for stimulating stem cell proliferation and cell cycle progression. It is known that LRF is highly expressed in the mouse limb buds prior to overt chondrogenesis; thus, LRF might function to prevent premature chondrogenic differentiation of stem cells. PMID:26069677

  4. Enhanced human papillomavirus type 8 oncogene expression levels are crucial for skin tumorigenesis in transgenic mice

    SciTech Connect

    Hufbauer, M.; Lazic, D.; Akguel, B.; Brandsma, J.L.; Pfister, H.; Weissenborn, S.J.

    2010-08-01

    Human papillomavirus 8 (HPV8) is involved in skin cancer development in epidermodysplasia verruciformis patients. Transgenic mice expressing HPV8 early genes (HPV8-CER) developed papillomas, dysplasias and squamous cell carcinomas. UVA/B-irradiation and mechanical wounding of HPV8-CER mouse skin led to prompt papilloma induction in about 3 weeks. The aim of this study was to analyze the kinetics and level of transgene expression in response to skin irritations. Transgene expression was already enhanced 1 to 2 days after UVA/B-irradiation or tape-stripping and maintained during papilloma development. The enhanced transgene expression could be assigned to UVB and not to UVA. Papilloma development was thus always paralleled by an increased transgene expression irrespective of the type of skin irritation. A knock-down of E6 mRNA by tattooing HPV8-E6-specific siRNA led to a delay and a lower incidence of papilloma development. This indicates that the early increase of viral oncogene expression is crucial for induction of papillomatosis.

  5. Altered tumor formation and evolutionary selection of genetic variants in the human MDM4 oncogene.

    PubMed

    Atwal, Gurinder Singh; Kirchhoff, Tomas; Bond, Elisabeth E; Montagna, Marco; Monagna, Marco; Menin, Chiara; Bertorelle, Roberta; Scaini, Maria Chiara; Bartel, Frank; Böhnke, Anja; Pempe, Christina; Gradhand, Elise; Hauptmann, Steffen; Offit, Kenneth; Levine, Arnold J; Bond, Gareth L

    2009-06-23

    A large body of evidence strongly suggests that the p53 tumor suppressor pathway is central in reducing cancer frequency in vertebrates. The protein product of the haploinsufficient mouse double minute 2 (MDM2) oncogene binds to and inhibits the p53 protein. Recent studies of human genetic variants in p53 and MDM2 have shown that single nucleotide polymorphisms (SNPs) can affect p53 signaling, confer cancer risk, and suggest that the pathway is under evolutionary selective pressure (1-4). In this report, we analyze the haplotype structure of MDM4, a structural homolog of MDM2, in several different human populations. Unusual patterns of linkage disequilibrium (LD) in the haplotype distribution of MDM4 indicate the presence of candidate SNPs that may also modify the efficacy of the p53 pathway. Association studies in 5 different patient populations reveal that these SNPs in MDM4 confer an increased risk for, or early onset of, human breast and ovarian cancers in Ashkenazi Jewish and European cohorts, respectively. This report not only implicates MDM4 as a key regulator of tumorigenesis in the human breast and ovary, but also exploits for the first time evolutionary driven linkage disequilibrium as a means to select SNPs of p53 pathway genes that might be clinically relevant.

  6. Satellite RNAs promote pancreatic oncogenic processes via the dysfunction of YBX1

    PubMed Central

    Kishikawa, Takahiro; Otsuka, Motoyuki; Yoshikawa, Takeshi; Ohno, Motoko; Ijichi, Hideaki; Koike, Kazuhiko

    2016-01-01

    Highly repetitive tandem arrays at the centromeric and pericentromeric regions in chromosomes, previously considered silent, are actively transcribed, particularly in cancer. This aberrant expression occurs even in K-ras-mutated pancreatic intraepithelial neoplasia (PanIN) tissues, which are precancerous lesions. To examine the biological roles of the satellite RNAs in carcinogenesis, we construct mouse PanIN-derived cells expressing major satellite (MajSAT) RNA and show increased malignant properties. We find an increase in frequency of chromosomal instability and point mutations in both genomic and mitochondrial DNA. We identify Y-box binding protein 1 (YBX1) as a protein that binds to MajSAT RNA. MajSAT RNA inhibits the nuclear translocation of YBX1 under stress conditions, thus reducing its DNA-damage repair function. The forced expression of YBX1 significantly decreases the aberrant phenotypes. These findings indicate that during the early stage of cancer development, satellite transcripts may act as ‘intrinsic mutagens' by inducing YBX1 dysfunction, which may be crucial in oncogenic processes. PMID:27667193

  7. The human DEK oncogene regulates DNA damage response signaling and repair

    PubMed Central

    Kavanaugh, Gina M.; Wise-Draper, Trisha M.; Morreale, Richard J.; Morrison, Monique A.; Gole, Boris; Schwemberger, Sandy; Tichy, Elisia D.; Lu, Lu; Babcock, George F.; Wells, James M.; Drissi, Rachid; Bissler, John J.; Stambrook, Peter J.; Andreassen, Paul R.; Wiesmüller, Lisa; Wells, Susanne I.

    2011-01-01

    The human DEK gene is frequently overexpressed and sometimes amplified in human cancer. Consistent with oncogenic functions, Dek knockout mice are partially resistant to chemically induced papilloma formation. Additionally, DEK knockdown in vitro sensitizes cancer cells to DNA damaging agents and induces cell death via p53-dependent and -independent mechanisms. Here we report that DEK is important for DNA double-strand break repair. DEK depletion in human cancer cell lines and xenografts was sufficient to induce a DNA damage response as assessed by detection of γH2AX and FANCD2. Phosphorylation of H2AX was accompanied by contrasting activation and suppression, respectively, of the ATM and DNA-PK pathways. Similar DNA damage responses were observed in primary Dek knockout mouse embryonic fibroblasts (MEFs), along with increased levels of DNA damage and exaggerated induction of senescence in response to genotoxic stress. Importantly, Dek knockout MEFs exhibited distinct defects in non-homologous end joining (NHEJ) when compared to their wild-type counterparts. Taken together, the data demonstrate new molecular links between DEK and DNA damage response signaling pathways, and suggest that DEK contributes to DNA repair. PMID:21653549

  8. Oncogenic steroid receptor coactivator-3 is a key regulator of the white adipogenic program

    PubMed Central

    Louet, Jean-Francois; Coste, Agnès; Amazit, Larbi; Tannour-Louet, Mounia; Wu, Ray-Chang; Tsai, Sophia Y.; Tsai, Ming-Jer; Auwerx, Johan; O'Malley, Bert W.

    2006-01-01

    The white adipocyte is at the center of dysfunctional regulatory pathways in various pathophysiological processes, including obesity, diabetes, inflammation, and cancer. Here, we show that the oncogenic steroid receptor coactivator-3 (SRC-3) is a critical regulator of white adipocyte development. Indeed, in SRC-3−/− mouse embryonic fibroblasts, adipocyte differentiation was severely impaired, and reexpression of SRC-3 was able to restore it. The early stages of adipocyte differentiation are accompanied by an increase in nuclear levels of SRC-3, which accumulates to high levels specifically in the nucleus of differentiated fat cells. Moreover, SRC-3−/− animals showed reduced body weight and adipose tissue mass with a significant decrease of the expression of peroxisome proliferator-activated receptor γ2 (PPARγ2), a master gene required for adipogenesis. At the molecular level, SRC-3 acts synergistically with the transcription factor CAAT/enhancer-binding protein to control the gene expression of PPARγ2. Collectively, these data suggest a crucial role for SRC-3 as an integrator of the complex transcriptional network controlling adipogenesis. PMID:17098861

  9. MELK is an oncogenic kinase essential for mitotic progression in basal-like breast cancer cells

    PubMed Central

    Wang, Yubao; Lee, Young-Mi; Baitsch, Lukas; Huang, Alan; Xiang, Yi; Tong, Haoxuan; Lako, Ana; Von, Thanh; Choi, Christine; Lim, Elgene; Min, Junxia; Li, Li; Stegmeier, Frank; Schlegel, Robert; Eck, Michael J; Gray, Nathanael S; Mitchison, Timothy J; Zhao, Jean J

    2014-01-01

    Despite marked advances in breast cancer therapy, basal-like breast cancer (BBC), an aggressive subtype of breast cancer usually lacking estrogen and progesterone receptors, remains difficult to treat. In this study, we report the identification of MELK as a novel oncogenic kinase from an in vivo tumorigenesis screen using a kinome-wide open reading frames (ORFs) library. Analysis of clinical data reveals a high level of MELK overexpression in BBC, a feature that is largely dependent on FoxM1, a master mitotic transcription factor that is also found to be highly overexpressed in BBC. Ablation of MELK selectively impairs proliferation of basal-like, but not luminal breast cancer cells both in vitro and in vivo. Mechanistically, depletion of MELK in BBC cells induces caspase-dependent cell death, preceded by defective mitosis. Finally, we find that Melk is not required for mouse development and physiology. Together, these data indicate that MELK is a normally non-essential kinase, but is critical for BBC and thus represents a promising selective therapeutic target for the most aggressive subtype of breast cancer. DOI: http://dx.doi.org/10.7554/eLife.01763.001 PMID:24844244

  10. Merkel cell polyomavirus small T antigen is oncogenic in transgenic mice

    PubMed Central

    Harms, Paul W.; Vozheiko, Tracy D.; Weick, Jack W.; Wilbert, Dawn M.; Saunders, Thomas L.; Ermilov, Alexandre N.; Bichakjian, Christopher K.; Johnson, Timothy M.; Imperiale, Michael J.; Dlugosz, Andrzej A.

    2014-01-01

    Merkel cell carcinoma (MCC) is a rare and deadly neuroendocrine skin tumor frequently associated with clonal integration of a polyomavirus, MCPyV, and MCC tumor cells express putative polyomavirus oncoproteins small T antigen (sTAg) and truncated large T antigen (tLTAg). Here, we show robust transforming activity of sTAg in vivo in a panel of transgenic mouse models. Epithelia of pre-term sTAg-expressing embryos exhibited hyperplasia, impaired differentiation, increased proliferation and apoptosis, and activation of a DNA damage response. Epithelial transformation did not require sTAg interaction with the PP2A protein complex, a tumor suppressor in some other polyomavirus transformation models, but was strictly dependent on a recently-described sTAg domain that binds Fbxw7, the substrate-binding component of the SCF ubiquitin ligase complex. Postnatal induction of sTAg using a Cre-inducible transgene also led to epithelial transformation with development of lesions resembling squamous cell carcinoma in situ and elevated expression of Fbxw7 target proteins. Our data establish that expression of MCPyV sTAg alone is sufficient for rapid neoplastic transformation in vivo, implicating sTAg as an oncogenic driver in MCC and perhaps other human malignancies. Moreover, the loss of transforming activity following mutation of the sTAg Fbxw7 binding domain identifies this domain as crucial for in vivo transformation. PMID:25313532

  11. MELK is an oncogenic kinase essential for mitotic progression in basal-like breast cancer cells.

    PubMed

    Wang, Yubao; Lee, Young-Mi; Baitsch, Lukas; Huang, Alan; Xiang, Yi; Tong, Haoxuan; Lako, Ana; Von, Thanh; Choi, Christine; Lim, Elgene; Min, Junxia; Li, Li; Stegmeier, Frank; Schlegel, Robert; Eck, Michael J; Gray, Nathanael S; Mitchison, Timothy J; Zhao, Jean J

    2014-01-01

    Despite marked advances in breast cancer therapy, basal-like breast cancer (BBC), an aggressive subtype of breast cancer usually lacking estrogen and progesterone receptors, remains difficult to treat. In this study, we report the identification of MELK as a novel oncogenic kinase from an in vivo tumorigenesis screen using a kinome-wide open reading frames (ORFs) library. Analysis of clinical data reveals a high level of MELK overexpression in BBC, a feature that is largely dependent on FoxM1, a master mitotic transcription factor that is also found to be highly overexpressed in BBC. Ablation of MELK selectively impairs proliferation of basal-like, but not luminal breast cancer cells both in vitro and in vivo. Mechanistically, depletion of MELK in BBC cells induces caspase-dependent cell death, preceded by defective mitosis. Finally, we find that Melk is not required for mouse development and physiology. Together, these data indicate that MELK is a normally non-essential kinase, but is critical for BBC and thus represents a promising selective therapeutic target for the most aggressive subtype of breast cancer.DOI: http://dx.doi.org/10.7554/eLife.01763.001. PMID:24844244

  12. c-Myc oncogene expression in selected odontogenic cysts and tumors: An immunohistochemical study

    PubMed Central

    Moosvi, Zama; Rekha, K

    2013-01-01

    Aim: To investigate the role of c-Myc oncogene in selected odontogenic cysts and tumors. Materials and Methods: Ten cases each of ameloblastoma, adenomatoid odontogenic tumor (AOT), odontogenic keratocyst (OKC), dentigerous cyst, and radicular cyst were selected and primary monoclonal mouse anti-human c-Myc antibody was used in a dilution of 1: 50. Statistical Analysis was performed using Mann Whitney U test. Results: 80% positivity was observed in ameloblastoma, AOT and OKC; 50% positivity in radicular cyst and 20% positivity in dentigerous cyst. Comparison of c-Myc expression between ameloblastoma and AOT did not reveal significant results. Similarly, no statistical significance was observed when results of OKC were compared with ameloblastoma and AOT. In contrast, significant differences were seen on comparison of dentigerous cyst with ameloblastoma and AOT and radicular cyst with AOT. Conclusion: From the above data we conclude that (1) Ameloblastoma and AOT have similar proliferative potential and their biologic behavior cannot possibly be attributed to it. (2) OKC has an intrinsic growth potential which is absent in other cysts and reinforces its classification as keratocystic odontogenic tumor. PMID:23798830

  13. Translation regulatory factor RBM3 is a proto-oncogene that prevents mitotic catastrophe

    PubMed Central

    Sureban, SM; Ramalingam, S; Natarajan, G; May, R; Subramaniam, D; Bishnupuri, KS; Morrison, AR; Dieckgraefe, BK; Brackett, DJ; Postier, RG; Houchen, CW; Anant, S

    2009-01-01

    RNA-binding proteins play a key role in post-transcriptional regulation of mRNA stability and translation. We have identified that RBM3, a translation regulatory protein, is significantly upregulated in human tumors, including a stage-dependent increase in colorectal tumors. Forced RBM3 overexpression in NIH3T3 mouse fibro-blasts and SW480 human colon epithelial cells increases cell proliferation and development of compact multicellular spheroids in soft agar suggesting the ability to induce anchorage-independent growth. In contrast, down-regulating RBM3 in HCT116 colon cancer cells with specific siRNA decreases cell growth in culture, which was partially overcome when treated with prostaglandin E2, a product of cyclooxygenase (COX)-2 enzyme activity. Knockdown also resulted in the growth arrest of tumor xenografts. We have also identified that RBM3 knockdown increases caspase-mediated apoptosis coupled with nuclear cyclin B1, and phosphorylated Cdc25c, Chk1 and Chk2 kinases, implying that under conditions of RBM3 downregulation, cells undergo mitotic catastrophe. RBM3 enhances COX-2, IL-8 and VEGF mRNA stability and translation. Conversely, RBM3 knockdown results in loss in the translation of these transcripts. These data demonstrate that the RNA stabilizing and translation regulatory protein RBM3 is a novel proto-oncogene that induces transformation when overexpressed and is essential for cells to progress through mitosis. PMID:18427544

  14. Genetic Modeling of PIM Proteins in Cancer: Proviral Tagging and Cooperation with Oncogenes, Tumor Suppressor Genes, and Carcinogens

    PubMed Central

    Aguirre, Enara; Renner, Oliver; Narlik-Grassow, Maja; Blanco-Aparicio, Carmen

    2014-01-01

    The PIM proteins, which were initially discovered as proviral insertion sites in Moloney-murine leukemia virus infection, are a family of highly homologous serine/threonine kinases that have been reported to be overexpressed in hematological malignancies and solid tumors. The PIM proteins have also been associated with metastasis and overall treatment responses and implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anti-cancer drug discovery. The use of retroviral insertional mutagenesis and refined approaches such as complementation tagging has allowed the identification of myc, pim, and a third group of genes (including bmi1 and gfi1) as complementing genes in lymphomagenesis. Moreover, mouse modeling of human cancer has provided an understanding of the molecular pathways that are involved in tumor initiation and progression at the physiological level. In particular, genetically modified mice have allowed researchers to further elucidate the role of each of the Pim isoforms in various tumor types. PIM kinases have been identified as weak oncogenes because experimental overexpression in lymphoid tissue, prostate, and liver induces tumors at a relatively low incidence and with a long latency. However, very strong synergistic tumorigenicity between Pim1/2 and c-Myc and other oncogenes has been observed in lymphoid tissues. Mouse models have also been used to study whether the inhibition of specific PIM isoforms is required to prevent carcinogen-induced sarcomas, indicating that the absence of Pim2 and Pim3 greatly reduces sarcoma growth and bone invasion; the extent of this effect is similar to that observed in the absence of all three isoforms. This review will summarize some of the animal models that have been used to understand the isoform-specific contribution of PIM kinases to tumorigenesis. PMID:24860787

  15. Genetic Modeling of PIM Proteins in Cancer: Proviral Tagging and Cooperation with Oncogenes, Tumor Suppressor Genes, and Carcinogens.

    PubMed

    Aguirre, Enara; Renner, Oliver; Narlik-Grassow, Maja; Blanco-Aparicio, Carmen

    2014-01-01

    The PIM proteins, which were initially discovered as proviral insertion sites in Moloney-murine leukemia virus infection, are a family of highly homologous serine/threonine kinases that have been reported to be overexpressed in hematological malignancies and solid tumors. The PIM proteins have also been associated with metastasis and overall treatment responses and implicated in the regulation of apoptosis, metabolism, the cell cycle, and homing and migration, which makes these proteins interesting targets for anti-cancer drug discovery. The use of retroviral insertional mutagenesis and refined approaches such as complementation tagging has allowed the identification of myc, pim, and a third group of genes (including bmi1 and gfi1) as complementing genes in lymphomagenesis. Moreover, mouse modeling of human cancer has provided an understanding of the molecular pathways that are involved in tumor initiation and progression at the physiological level. In particular, genetically modified mice have allowed researchers to further elucidate the role of each of the Pim isoforms in various tumor types. PIM kinases have been identified as weak oncogenes because experimental overexpression in lymphoid tissue, prostate, and liver induces tumors at a relatively low incidence and with a long latency. However, very strong synergistic tumorigenicity between Pim1/2 and c-Myc and other oncogenes has been observed in lymphoid tissues. Mouse models have also been used to study whether the inhibition of specific PIM isoforms is required to prevent carcinogen-induced sarcomas, indicating that the absence of Pim2 and Pim3 greatly reduces sarcoma growth and bone invasion; the extent of this effect is similar to that observed in the absence of all three isoforms. This review will summarize some of the animal models that have been used to understand the isoform-specific contribution of PIM kinases to tumorigenesis. PMID:24860787

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

    PubMed

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

    2014-01-17

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

  17. Melanoma proliferation and chemoresistance controlled by the DEK oncogene

    PubMed Central

    Khodadoust, Michael S.; Verhaegen, Monique; Kappes, Ferdinand; Riveiro-Falkenbach, Erica; Cigudosa, Juan C.; Kim, David S.L.; Chinnaiyan, Arul M.; Markovitz, David M.; Soengas, María S.

    2009-01-01

    Gain of chromosome 6p is a consistent feature of advanced melanomas. However, the identity of putative oncogene(s) associated with this amplification has remained elusive. The chromatin remodeling factor DEK is an attractive candidate as it maps to 6p (i.e. within common melanoma-amplified loci). Moreover, DEK expression is increased in metastatic melanomas, although the functional relevance of this induction remains unclear. Importantly, in other tumor types, DEK can display various tumorigenic effects, in part through its ability to promote proliferation and inhibit p53-dependent apoptosis. Here, we report a generalized upregulation of DEK protein in cells from aggressive melanomas. In addition, we provide genetic and mechanistic evidence to support a key role of DEK in the maintenance of malignant phenotypes of melanoma cells. Specifically, we show that long-term DEK downregulation by independent shRNAs resulted in premature senescence of a variety of melanoma cell lines. Short-term abrogation of DEK expression was also functionally relevant, as it attenuated the traditional resistance of melanomas to DNA damaging agents. Unexpectedly, DEK shRNA had no impact on p53 levels or p53-dependent apoptosis. Instead, we identified a new role for DEK in the transcriptional activation of the antiapoptotic MCL-1. Other MCL-1 related factors such as BCL-2 or BCL-xL were unaffected by changes in the endogenous levels of DEK, indicating a selective impact of this gene on the apoptotic machinery of melanoma cells. These results provide support for DEK as a long sought-after oncogene mapping at chromosome 6, with novel functions in melanoma proliferation and chemoresistance. PMID:19679545

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

    PubMed

    Brendel, Cornelia; Teichler, Sabine; Millahn, Axel; Stiewe, Thorsten; Krause, Michael; Stabla, Kathleen; Ross, Petra; Huynh, Minh; Illmer, Thomas; Mernberger, Marco; Barckhausen, Christina; Neubauer, Andreas

    2015-01-01

    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. PMID:25901794

  19. Autism Linked to Increased Oncogene Mutations but Decreased Cancer Rate

    PubMed Central

    Zimmerman, M. Bridget; Mahajan, Vinit B.; Bassuk, Alexander G.

    2016-01-01

    Autism spectrum disorder (ASD) is one phenotypic aspect of many monogenic, hereditary cancer syndromes. Pleiotropic effects of cancer genes on the autism phenotype could lead to repurposing of oncology medications to treat this increasingly prevalent neurodevelopmental condition for which there is currently no treatment. To explore this hypothesis we sought to discover whether autistic patients more often have rare coding, single-nucleotide variants within tumor suppressor and oncogenes and whether autistic patients are more often diagnosed with neoplasms. Exome-sequencing data from the ARRA Autism Sequencing Collaboration was compared to that of a control cohort from the Exome Variant Server database revealing that rare, coding variants within oncogenes were enriched for in the ARRA ASD cohort (p<1.0x10-8). In contrast, variants were not significantly enriched in tumor suppressor genes. Phenotypically, children and adults with ASD exhibited a protective effect against cancer, with a frequency of 1.3% vs. 3.9% (p<0.001), but the protective effect decreased with age. The odds ratio of neoplasm for those with ASD relative to controls was 0.06 (95% CI: 0.02, 0.19; p<0.0001) in the 0 to 14 age group; 0.35 (95% CI: 0.14, 0.87; p = 0.024) in the 15 to 29 age group; 0.41 (95% CI: 0.15, 1.17; p = 0.095) in the 30 to 54 age group; and 0.49 (95% CI: 0.14, 1.74; p = 0.267) in those 55 and older. Both males and females demonstrated the protective effect. These findings suggest that defects in cellular proliferation, and potentially senescence, might influence both autism and neoplasm, and already approved drugs targeting oncogenic pathways might also have therapeutic value for treating autism. PMID:26934580

  20. Suppression of Myc oncogenic activity by ribosomal protein haploinsufficiency.

    PubMed

    Barna, Maria; Pusic, Aya; Zollo, Ornella; Costa, Maria; Kondrashov, Nadya; Rego, Eduardo; Rao, Pulivarthi H; Ruggero, Davide

    2008-12-18

    The Myc oncogene regulates the expression of several components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, RNA polymerase III and ribosomal DNA. Whether and how increasing the cellular protein synthesis capacity affects the multistep process leading to cancer remains to be addressed. Here we use ribosomal protein heterozygote mice as a genetic tool to restore increased protein synthesis in Emu-Myc/+ transgenic mice to normal levels, and show that the oncogenic potential of Myc in this context is suppressed. Our findings demonstrate that the ability of Myc to increase protein synthesis directly augments cell size and is sufficient to accelerate cell cycle progression independently of known cell cycle targets transcriptionally regulated by Myc. In addition, when protein synthesis is restored to normal levels, Myc-overexpressing precancerous cells are more efficiently eliminated by programmed cell death. Our findings reveal a new mechanism that links increases in general protein synthesis rates downstream of an oncogenic signal to a specific molecular impairment in the modality of translation initiation used to regulate the expression of selective messenger RNAs. We show that an aberrant increase in cap-dependent translation downstream of Myc hyperactivation specifically impairs the translational switch to internal ribosomal entry site (IRES)-dependent translation that is required for accurate mitotic progression. Failure of this translational switch results in reduced mitotic-specific expression of the endogenous IRES-dependent form of Cdk11 (also known as Cdc2l and PITSLRE), which leads to cytokinesis defects and is associated with increased centrosome numbers and genome instability in Emu-Myc/+ mice. When accurate translational control is re-established in Emu-Myc/+ mice, genome instability is suppressed. Our findings demonstrate how perturbations in translational control provide a highly specific outcome

  1. Oncogenic rearrangements driving ionizing radiation–associated human cancer

    PubMed Central

    Santoro, Massimo; Carlomagno, Francesca

    2013-01-01

    The Chernobyl nuclear disaster has caused a remarkable increase in radiation-induced papillary thyroid carcinoma in children and young adults. In this issue of the JCI, Ricarte-Filho and colleagues demonstrate that chromosomal rearrangements are the oncogenic “drivers” in most post-Chernobyl carcinomas and that they often lead to unscheduled activation of the MAPK signaling pathway. These findings represent a major step forward in our understanding of radiation-induced carcinogenesis and suggest various hypotheses about the mechanisms underlying the formation and selection of gene rearrangements during cancer cell evolution. PMID:24162670

  2. Hedgehog Signal Transduction: Key Players, Oncogenic Drivers, and Cancer Therapy.

    PubMed

    Pak, Ekaterina; Segal, Rosalind A

    2016-08-22

    The Hedgehog (Hh) signaling pathway governs complex developmental processes, including proliferation and patterning within diverse tissues. These activities rely on a tightly regulated transduction system that converts graded Hh input signals into specific levels of pathway activity. Uncontrolled activation of Hh signaling drives tumor initiation and maintenance. However, recent entry of pathway-specific inhibitors into the clinic reveals mixed patient responses and thus prompts further exploration of pathway activation and inhibition. In this review, we share emerging insights into regulated and oncogenic Hh signaling, supplemented with updates on the development and use of Hh pathway-targeted therapies.

  3. Global expression profiling reveals gain-of-function onco-genic activity of a mutated thyroid hormone receptor in thyroid carcinogenesis

    PubMed Central

    Lu, Changxue; Mishra, Alok; Zhu, Yuelin J; Meltzer, Paul; Cheng, Sheue-yann

    2011-01-01

    Thyroid hormone receptors (TRs) are critical in regulating gene expression in normal physiological processes. Decreased expression and/or somatic mutations of TRs have been shown to be associated several types of human cancers including liver, breast, lung, and thyroid. To understand the molecular mechanisms by which mutated TRs promote carcinogenesis, an animal model of follicular thyroid carcinoma (FTC) (Thrbpv/pv mice) was used in the present study. The Thrbpv/pv mouse harbors a knockin dominant negative PV mutation, identified in a patient with resistance to thyroid hormone. To understand whether oncogenic actions of PV involve not only the loss of normal TR functions but also gain-of-function activities, we compared the gene expression profiles of thyroid lesions in Thrbpv/pv mice and Thra1-/- Thrb-/- mice that also spontaneously develop FTC, but with less severe malignancy. Analysis of the cDNA microarray data derived from microdissected thyroid tumor cells of these two mice showed contrasting global gene expression profiles. With stringent selection using 2.5-fold change (p<0.01) in cDNA microarray analysis, 241 genes with altered gene expression were identified. Nearly half of the genes (n=103: 42.7% of total) with altered gene expression in thyroid tumor cells of Thrbpv/pv mice were associated with tumorigenesis and metastasis; some of these genes function as oncogenes in human thyroid cancers. The remaining genes were found to function in transcriptional regulation, RNA processing, cell proliferation, apoptosis, angiogenesis, and cytoskeleton modification. These results indicate that the more aggressive thyroid tumor progression in Thrbpv/pv mice was not due simply to the loss of tumor suppressor functions of TR via mutation but also, importantly, to gain-of-function in the oncogenic activities of PV to drive thyroid carcinogenesis. Thus, the present study identifies a novel mechanism by which a mutated TRβ evolves with an oncogenic advantage to promote

  4. Characterization of Bcor expression in mouse development.

    PubMed

    Wamstad, Joseph A; Bardwell, Vivian J

    2007-04-01

    Mutation of the gene encoding the transcriptional corepressor BCOR results in the X-linked disorder Oculofaciocardiodental syndrome (OFCD or MCOPS2). Female OFCD patients suffer from severe ocular, craniofacial, cardiac, and digital developmental defects and males do not survive through gestation. BCOR can mediate transcriptional repression by the oncoprotein BCL6 and has the ability to reduce transcriptional activation by AF9, a known mixed-lineage leukemia (MLL) fusion partner. The essential role of BCOR in development and its ability to modulate activity of known oncogenic proteins prompted us to determine the expression profile of Bcor during mouse development. Identification of independently transcribed exons in the 5' untranslated region of Bcor suggests that three independent promoters control the expression of Bcor in mice. Although Bcor is widely expressed in adult mouse tissues, analysis of known spliced isoforms in the coding region of Bcor reveals differential isoform usage. Whole mount in situ hybridization of mouse embryos shows that Bcor is strongly expressed in the extraembryonic tissue during gastrulation and expression significantly increases throughout the embryo after embryonic turning. During organogenesis and fetal stages Bcor is differentially expressed in multiple tissue lineages, with a notable presence in the developing nervous system. Strikingly, we observed that Bcor expression in the eye, brain, neural tube, and branchial arches correlates with tissues affected in OFCD patients. PMID:17344103

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

    PubMed

    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'. PMID:24780858

  6. Secreted primary human malignant mesothelioma exosome signature reflects oncogenic cargo.

    PubMed

    Greening, David W; Ji, Hong; Chen, Maoshan; Robinson, Bruce W S; Dick, Ian M; Creaney, Jenette; Simpson, Richard J

    2016-01-01

    Malignant mesothelioma (MM) is a highly-aggressive heterogeneous malignancy, typically diagnosed at advanced stage. An important area of mesothelioma biology and progression is understanding intercellular communication and the contribution of the secretome. Exosomes are secreted extracellular vesicles shown to shuttle cellular cargo and direct intercellular communication in the tumour microenvironment, facilitate immunoregulation and metastasis. In this study, quantitative proteomics was used to investigate MM-derived exosomes from distinct human models and identify select cargo protein networks associated with angiogenesis, metastasis, and immunoregulation. Utilising bioinformatics pathway/network analyses, and correlation with previous studies on tumour exosomes, we defined a select mesothelioma exosomal signature (mEXOS, 570 proteins) enriched in tumour antigens and various cancer-specific signalling (HPGD/ENO1/OSMR) and secreted modulators (FN1/ITLN1/MAMDC2/PDGFD/GBP1). Notably, such circulating cargo offers unique insights into mesothelioma progression and tumour microenvironment reprogramming. Functionally, we demonstrate that oncogenic exosomes facilitate the migratory capacity of fibroblast/endothelial cells, supporting the systematic model of MM progression associated with vascular remodelling and angiogenesis. We provide biophysical and proteomic characterisation of exosomes, define a unique oncogenic signature (mEXOS), and demonstrate the regulatory capacity of exosomes in cell migration/tube formation assays. These findings contribute to understanding tumour-stromal crosstalk in the context of MM, and potential new diagnostic and therapeutic extracellular targets.

  7. Insulator dysfunction and oncogene activation in IDH mutant gliomas

    PubMed Central

    Flavahan, William A.; Drier, Yotam; Liau, Brian B.; Gillespie, Shawn M.; Venteicher, Andrew S.; Stemmer-Rachamimov, Anat O.; Suvà, Mario L.; Bernstein, Bradley E.

    2015-01-01

    Gain-of-function IDH mutations are initiating events that define major clinical and prognostic classes of gliomas1,2. Mutant IDH protein produces a novel onco-metabolite, 2-hydroxyglutarate (2-HG), that interferes with iron-dependent hydroxylases, including the TET family of 5′-methylcytosine hydroxylases3–7. TET enzymes catalyze a key step in the removal of DNA methylation8,9. IDH mutant gliomas thus manifest a CpG island methylator phenotype (G-CIMP)10,11, though the functional significance of this altered epigenetic state remains unclear. Here we show that IDH mutant gliomas exhibit hyper-methylation at CTCF binding sites, compromising binding of this methylation-sensitive insulator protein. Reduced CTCF binding is associated with loss of insulation between topological domains and aberrant gene activation. We specifically demonstrate that loss of CTCF at a domain boundary permits a constitutive enhancer to aberrantly interact with the receptor tyrosine kinase gene PDGFRA, a prominent glioma oncogene. Treatment of IDH mutant gliomaspheres with demethylating agent partially restores insulator function and down-regulates PDGFRA. Conversely, CRISPR-mediated disruption of the CTCF motif in IDH wildtype gliomaspheres up-regulates PDGFRA and increases proliferation. Our study suggests that IDH mutations promote gliomagenesis by disrupting chromosomal topology and allowing aberrant regulatory interactions that induce oncogene expression. PMID:26700815

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

    PubMed

    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'.

  9. FES kinases are required for oncogenic FLT3 signaling.

    PubMed

    Voisset, E; Lopez, S; Chaix, A; Georges, C; Hanssens, K; Prébet, T; Dubreuil, P; De Sepulveda, P

    2010-04-01

    The closely related non-receptor tyrosine kinases FEline Sarcoma (FES) and FEs Related (FER) are activated by cell surface receptors in hematopoietic cells. Despite the early description of oncogenic viral forms of fes, v-fes, and v-fps, the implication of FES and FER in human pathology is not known. We have recently shown that FES but not FER is necessary for oncogenic KIT receptor signaling. Here, we report that both FES and FER kinases are activated in primary acute myeloid leukemia (AML) blasts and in AML cell lines. FES and FER activation is dependent on FLT3 in cell lines harboring constitutively active FLT3 mutants. Moreover, both FES and FER proteins are critical for FLT3-internal tandem duplication (ITD) signaling and for cell proliferation in relevant AML cell lines. FER is required for cell cycle transitions, whereas FES seems necessary for cell survival. We concluded that FES and FER kinases mediate essential non-redundant functions downstream of FLT3-ITD.

  10. Expression of proto-oncogenes in bovine preimplantation blastocysts.

    PubMed

    Tetens, F; Kliem, A; Tscheudschilsuren, G; Navarrete Santos, A; Fischer, B

    2000-05-01

    Proto-oncogenes are involved in the regulation of gene expression, for example after ligand binding to growth factor receptors. Expression of the proto-oncogenes c-fos, c-jun, c-ha-ras and c-myc was studied in in vivo grown and in vitro cultured bovine preimplantation blastocysts employing RT-PCR, ribonuclease protection assay and immunohistochemistry. Thirteen- and 14- day-old preimplantation blastocysts, i.e. stages before and during trophoblast elongation, were used. In in vivo-grown blastocysts c-fos, c-jun and c-ha-ras transcripts as well as c-Fos, c-Jun and c-Myc proteins were detected in all stages studied. Cultured blastocysts were treated with 10 nM epidermal growth factor and 10 nM transforming growth factor-alpha simultaneously. Epidermal growth factor and transforming growth factor-alpha treatment induced c-fos mRNA and c-Myc protein expression. The induction of downstream targets of the epidermal growth factor receptor by epidermal growth factor and transforming growth factor-alpha indicates a functional epidermal growth factor signal transduction pathway in elongating bovine blastocysts.

  11. Evidence for long-range oncogene activation by hepadnavirus insertion.

    PubMed Central

    Fourel, G; Couturier, J; Wei, Y; Apiou, F; Tiollais, P; Buendia, M A

    1994-01-01

    Insertional mutagenesis of host genes, a common oncogenic strategy of slow transforming retroviruses, has recently been described for a DNA virus of the hepadnavirus group: the woodchuck hepatitis virus. This virus causes insertional activation of myc genes, mainly the intronless N-myc2 oncogene, in > 50% of woodchuck liver tumours. In most remaining tumours, N-myc2 is overexpressed without any apparent genetic alteration. To elucidate the role of the virus in such cases, we have cloned and analysed single integration sites in four woodchuck tumours carrying wild-type myc alleles. All sites were clustered within < 20 kb in a single locus, in which scarce unique sequences showed no detectable transcriptional activity. By fluorescent in situ hybridization, N-myc2 and the new locus (win) were localized to the same region of the long arm of the woodchuck X chromosome, and a 150-180 kb intervening distance was deduced from pulse-field gel analysis. The detection of viral integrations in win in additional tumours that produced abundant N-myc2 transcripts further substantiates the link between these two loci in woodchuck tumorigenesis. We propose that efficient activation of the N-myc2 promoter by the hepadnavirus enhancer acting over a long distance might operate in liver cell transformation. Images PMID:8013453

  12. Oncogenicity of the developmental transcription factor Sox9

    PubMed Central

    Matheu, Ander; Collado, Manuel; Wise, Clare; Manterola, Lorea; Cekaite, Lina; Tye, Angela J.; Canamero, Marta; Bujanda, Luis; Schedl, Andreas; Cheah, Kathryn S.E.; Skotheim, Rolf I.; Lothe, Ragnhild A.; de Munain, Adolfo López; Briscoe, James; Serrano, Manuel; Lovell-Badge, Robin

    2012-01-01

    SOX9, a high mobility group (HMG) box transcription factor, plays critical roles during embryogenesis and its activity is required for development, differentiation and lineage commitment in various tissues including the intestinal epithelium. Here, we present functional and clinical data of a broadly important role for SOX9 in tumorigenesis. SOX9 was overexpressed in a wide range of human cancers, where its expression correlated with malignant character and progression. Gain of SOX9 copy number is detected in some primary colorectal cancers. SOX9 exhibited several pro-oncogenic properties, including the ability to promote proliferation, inhibit senescence and collaborate with other oncogenes in neoplastic transformation. In primary MEFs and colorectal cancer cells, SOX9 expression facilitated tumor growth and progression whilst its inactivation reduced tumorigenicity. Mechanistically, we have found that Sox9 directly binds and activates the promoter of the polycomb protein Bmi1, whose upregulation represses the tumor suppressor Ink4a/Arf locus. In agreement with this, human colorectal cancers showed a positive correlation between expression levels of SOX9 and BMI1 and a negative correlation between SOX9 and ARF in clinical samples. Taken together, our findings provide direct mechanistic evidence of the involvement of SOX9 in neoplastic pathobiology, particularly in colorectal cancer. PMID:22246670

  13. Secreted primary human malignant mesothelioma exosome signature reflects oncogenic cargo

    NASA Astrophysics Data System (ADS)

    Greening, David W.; Ji, Hong; Chen, Maoshan; Robinson, Bruce W. S.; Dick, Ian M.; Creaney, Jenette; Simpson, Richard J.

    2016-09-01

    Malignant mesothelioma (MM) is a highly-aggressive heterogeneous malignancy, typically diagnosed at advanced stage. An important area of mesothelioma biology and progression is understanding intercellular communication and the contribution of the secretome. Exosomes are secreted extracellular vesicles shown to shuttle cellular cargo and direct intercellular communication in the tumour microenvironment, facilitate immunoregulation and metastasis. In this study, quantitative proteomics was used to investigate MM-derived exosomes from distinct human models and identify select cargo protein networks associated with angiogenesis, metastasis, and immunoregulation. Utilising bioinformatics pathway/network analyses, and correlation with previous studies on tumour exosomes, we defined a select mesothelioma exosomal signature (mEXOS, 570 proteins) enriched in tumour antigens and various cancer-specific signalling (HPGD/ENO1/OSMR) and secreted modulators (FN1/ITLN1/MAMDC2/PDGFD/GBP1). Notably, such circulating cargo offers unique insights into mesothelioma progression and tumour microenvironment reprogramming. Functionally, we demonstrate that oncogenic exosomes facilitate the migratory capacity of fibroblast/endothelial cells, supporting the systematic model of MM progression associated with vascular remodelling and angiogenesis. We provide biophysical and proteomic characterisation of exosomes, define a unique oncogenic signature (mEXOS), and demonstrate the regulatory capacity of exosomes in cell migration/tube formation assays. These findings contribute to understanding tumour-stromal crosstalk in the context of MM, and potential new diagnostic and therapeutic extracellular targets.

  14. Oncogenic osteomalacia: two case reports with surprisingly different outcomes.

    PubMed

    Seijas, Roberto; Ares, Oscar; Sierra, Judit; Pérez-Dominguez, Manuel

    2009-04-01

    Oncogenic osteomalacia is a rare paraneoplastic syndrome of acquired hypophosphatemic osteomalacia, resulting from a deficit in renal tubular phosphate reabsorption, in which fibroblast growth factor 23 (FGF23) seems to be implicated. This condition is usually associated with a phosphaturic mesenchymal tumor of mixed connective tissue located in the bone or soft tissue. The clinical and the radiologic findings are the same as those seen in osteomalacia, and the biochemical features include renal phosphate loss, low serum phosphate and 1,25-(OH)(2) vitD(3) levels, increased alkaline phosphatase, and normal calcium, PTH, calcitonin, 25-OH-vitD(3) and 25,25-(OH)(2) vitD(3). We present two cases of oncogenic osteomalacia associated with phosphaturic mesenchymal tumors, which were histologically similar, but presented a completely different evolution. In the first patient, the tumor developed on the sole of the foot. Following removal of the mass, the symptoms resolved and biochemical and radiological parameters returned to normal. However, in the second patient, a liver tumor developed and resection did not resolve the disease. Multiple lesions appeared in several locations during follow-up. This disease usually remits with complete tumor resection. Nevertheless, if this is not possible, oral treatment with phosphate, calcium and calcitriol can improve the symptoms. If scintigraphy of the tumor shows octreotide receptors, patients may respond partially to therapy with somatostatin analogs, with stabilization of the lesion.

  15. Secreted primary human malignant mesothelioma exosome signature reflects oncogenic cargo

    PubMed Central

    Greening, David W.; Ji, Hong; Chen, Maoshan; Robinson, Bruce W. S.; Dick, Ian M.; Creaney, Jenette; Simpson, Richard J.

    2016-01-01

    Malignant mesothelioma (MM) is a highly-aggressive heterogeneous malignancy, typically diagnosed at advanced stage. An important area of mesothelioma biology and progression is understanding intercellular communication and the contribution of the secretome. Exosomes are secreted extracellular vesicles shown to shuttle cellular cargo and direct intercellular communication in the tumour microenvironment, facilitate immunoregulation and metastasis. In this study, quantitative proteomics was used to investigate MM-derived exosomes from distinct human models and identify select cargo protein networks associated with angiogenesis, metastasis, and immunoregulation. Utilising bioinformatics pathway/network analyses, and correlation with previous studies on tumour exosomes, we defined a select mesothelioma exosomal signature (mEXOS, 570 proteins) enriched in tumour antigens and various cancer-specific signalling (HPGD/ENO1/OSMR) and secreted modulators (FN1/ITLN1/MAMDC2/PDGFD/GBP1). Notably, such circulating cargo offers unique insights into mesothelioma progression and tumour microenvironment reprogramming. Functionally, we demonstrate that oncogenic exosomes facilitate the migratory capacity of fibroblast/endothelial cells, supporting the systematic model of MM progression associated with vascular remodelling and angiogenesis. We provide biophysical and proteomic characterisation of exosomes, define a unique oncogenic signature (mEXOS), and demonstrate the regulatory capacity of exosomes in cell migration/tube formation assays. These findings contribute to understanding tumour-stromal crosstalk in the context of MM, and potential new diagnostic and therapeutic extracellular targets. PMID:27605433

  16. Proteogenomic analysis reveals exosomes are more oncogenic than ectosomes.

    PubMed

    Keerthikumar, Shivakumar; Gangoda, Lahiru; Liem, Michael; Fonseka, Pamali; Atukorala, Ishara; Ozcitti, Cemil; Mechler, Adam; Adda, Christopher G; Ang, Ching-Seng; Mathivanan, Suresh

    2015-06-20

    Extracellular vesicles (EVs) include the exosomes (30-100 nm) that are produced through the endocytic pathway via the multivesicular bodies and the ectosomes (100-1000 nm) that are released through the budding of the plasma membrane. Despite the differences in the mode of biogenesis and size, reliable markers that can distinguish between exosomes and ectosomes are non-existent. Moreover, the precise functional differences between exosomes and ectosomes remains poorly characterised. Here, using label-free quantitative proteomics, we highlight proteins that could be exploited as markers to discriminate between exosomes and ectosomes. For the first time, a global proteogenomics analysis unveiled the secretion of mutant proteins that are implicated in cancer progression through tumor-derived EVs. Follow up integrated bioinformatics analysis highlighted the enrichment of oncogenic cargo in exosomes and ectosomes. Interestingly, exosomes induced significant cell proliferation and migration in recipient cells compared to ectosomes confirming the oncogenic nature of exosomes. These findings ascertain that cancer cells facilitate oncogenesis by the secretion of mutant and oncoproteins into the tumor microenvironment via exosomes and ectosomes. The integrative proteogenomics approach utilized in this study has the potential to identify disease biomarker candidates which can be later assayed in liquid biopsies obtained from cancer patients.

  17. Proteogenomic analysis reveals exosomes are more oncogenic than ectosomes

    PubMed Central

    Liem, Michael; Fonseka, Pamali; Atukorala, Ishara; Ozcitti, Cemil; Mechler, Adam; Adda, Christopher G.; Ang, Ching-Seng; Mathivanan, Suresh

    2015-01-01

    Extracellular vesicles (EVs) include the exosomes (30-100 nm) that are produced through the endocytic pathway via the multivesicular bodies and the ectosomes (100-1000 nm) that are released through the budding of the plasma membrane. Despite the differences in the mode of biogenesis and size, reliable markers that can distinguish between exosomes and ectosomes are non-existent. Moreover, the precise functional differences between exosomes and ectosomes remains poorly characterised. Here, using label-free quantitative proteomics, we highlight proteins that could be exploited as markers to discriminate between exosomes and ectosomes. For the first time, a global proteogenomics analysis unveiled the secretion of mutant proteins that are implicated in cancer progression through tumor-derived EVs. Follow up integrated bioinformatics analysis highlighted the enrichment of oncogenic cargo in exosomes and ectosomes. Interestingly, exosomes induced significant cell proliferation and migration in recipient cells compared to ectosomes confirming the oncogenic nature of exosomes. These findings ascertain that cancer cells facilitate oncogenesis by the secretion of mutant and oncoproteins into the tumor microenvironment via exosomes and ectosomes. The integrative proteogenomics approach utilized in this study has the potential to identify disease biomarker candidates which can be later assayed in liquid biopsies obtained from cancer patients. PMID:25944692

  18. Secreted primary human malignant mesothelioma exosome signature reflects oncogenic cargo.

    PubMed

    Greening, David W; Ji, Hong; Chen, Maoshan; Robinson, Bruce W S; Dick, Ian M; Creaney, Jenette; Simpson, Richard J

    2016-01-01

    Malignant mesothelioma (MM) is a highly-aggressive heterogeneous malignancy, typically diagnosed at advanced stage. An important area of mesothelioma biology and progression is understanding intercellular communication and the contribution of the secretome. Exosomes are secreted extracellular vesicles shown to shuttle cellular cargo and direct intercellular communication in the tumour microenvironment, facilitate immunoregulation and metastasis. In this study, quantitative proteomics was used to investigate MM-derived exosomes from distinct human models and identify select cargo protein networks associated with angiogenesis, metastasis, and immunoregulation. Utilising bioinformatics pathway/network analyses, and correlation with previous studies on tumour exosomes, we defined a select mesothelioma exosomal signature (mEXOS, 570 proteins) enriched in tumour antigens and various cancer-specific signalling (HPGD/ENO1/OSMR) and secreted modulators (FN1/ITLN1/MAMDC2/PDGFD/GBP1). Notably, such circulating cargo offers unique insights into mesothelioma progression and tumour microenvironment reprogramming. Functionally, we demonstrate that oncogenic exosomes facilitate the migratory capacity of fibroblast/endothelial cells, supporting the systematic model of MM progression associated with vascular remodelling and angiogenesis. We provide biophysical and proteomic characterisation of exosomes, define a unique oncogenic signature (mEXOS), and demonstrate the regulatory capacity of exosomes in cell migration/tube formation assays. These findings contribute to understanding tumour-stromal crosstalk in the context of MM, and potential new diagnostic and therapeutic extracellular targets. PMID:27605433

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

    PubMed

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

    1991-04-01

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

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

    PubMed

    Watari, Akihiro

    2012-01-01

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

  1. c-Rel Regulates Inscuteable Gene Expression during Mouse Embryonic Stem Cell Differentiation.

    PubMed

    Ishibashi, Riki; Kozuki, Satoshi; Kamakura, Sachiko; Sumimoto, Hideki; Toyoshima, Fumiko

    2016-02-12

    Inscuteable (Insc) regulates cell fate decisions in several types of stem cells. Although it is recognized that the expression levels of mouse INSC govern the balance between symmetric and asymmetric stem cell division, regulation of mouse Insc gene expression remains poorly understood. Here, we showed that mouse Insc expression transiently increases at an early stage of differentiation, when mouse embryonic stem (mES) cells differentiate into bipotent mesendoderm capable of producing both endoderm and mesoderm in defined culture conditions. We identified the minimum transcriptional regulatory element (354 bases) that drives mouse Insc transcription in mES cells within a region >5 kb upstream of the mouse Insc transcription start site. We found that the transcription factor reticuloendotheliosis oncogene (c-Rel) bound to the minimum element and promoted mouse Insc expression in mES cells. In addition, short interfering RNA-mediated knockdown of either mouse INSC or c-Rel protein decreased mesodermal cell populations without affecting differentiation into the mesendoderm or endoderm. Furthermore, overexpression of mouse INSC rescued the mesoderm-reduced phenotype induced by knockdown of c-Rel. We propose that regulation of mouse Insc expression by c-Rel modulates cell fate decisions during mES cell differentiation.

  2. Can anti-tumor immunity help to explain “oncogene addiction”?

    PubMed Central

    Restifo, Nicholas P.

    2010-01-01

    Summary “Oncogene addiction” refers to the process of tumor cell death that can occur after inactivation of a single oncogene. In this issue of Cancer Cell, Rakhra, et al. argue that complete tumor clearance after molecular targeted therapies requires a functioning immune system, pointing the way toward radically new combination therapies. PMID:21075303

  3. [Expression of proto-oncogenes and its role in spermatogenic cells].

    PubMed

    Yang, Jun-ling; Xu, Si-fan

    2005-07-01

    This article reviews the specific expression of many proto-oncogenes during male germ cell development. The normal expression of proto-oncogenes plays an important role in the regulation of spermatogonial mitosis, spermatocyte meiosis as well as spermiogenesis and sperm maturation.

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

    PubMed

    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.

  5. Inhibition of cell transformation by sulindac sulfide is confined to specific oncogenic pathways

    PubMed Central

    Gala, Manish; Sun, Ronggai; Yang, Vincent W.

    2009-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce the risk of colorectal cancer (CRC). They are also known to induce the regression of colorectal adenomas, which are precursors to CRC. Despite these evidences, the exact mechanism by which NSAIDs exerts its anti-oncogenic effect is not completely understood. Using a focus formation assay, here we show that sulindac sulfide, a NSAID, specifically inhibits cell transformation mediated by oncogenic Ha-Ras, but not by other established oncogene products such as v-Src, Gα 12, and Gα13. Our results suggest that the ability of sulindac sulfide to suppress transformation is confined to specific oncogenic pathways. Further studies of the sulindac-resistant oncogenic pathways may lead to identification of novel therapeutic agents that are effective in the prevention or treatment of CRC. PMID:11734340

  6. Overview of KRAS-Driven Genetically Engineered Mouse Models of Non-Small Cell Lung Cancer.

    PubMed

    Sheridan, Clare; Downward, Julian

    2015-01-01

    KRAS, the most frequently mutated oncogene in non-small cell lung cancer, has been utilized extensively to model human lung adenocarcinomas. The results from such studies have enhanced considerably an understanding of the relationship between KRAS and the development of lung cancer. Detailed in this overview are the features of various KRAS-driven genetically engineered mouse models (GEMMs) of non-small cell lung cancer, their utilization, and the potential of these models for the study of lung cancer biology.

  7. PNUTS functions as a proto-oncogene by sequestering PTEN.

    PubMed

    Kavela, Sridhar; Shinde, Swapnil R; Ratheesh, Raman; Viswakalyan, Kotapalli; Bashyam, Murali D; Gowrishankar, Swarnalata; Vamsy, Mohana; Pattnaik, Sujit; Rao, Subramanyeshwar; Sastry, Regulagadda A; Srinivasulu, Mukta; Chen, Junjie; Maddika, Subbareddy

    2013-01-01

    PTEN is a well-defined tumor suppressor gene that antagonizes the PI3K/Akt pathway to regulate a multitude of cellular processes, such as survival, growth, motility, invasiveness, and angiogenesis. While the functions of PTEN have been studied extensively, the regulation of its activity during normal and disease conditions still remains incompletely understood. In this study, we identified the protein phosphatase-1 nuclear targeting subunit PNUTS (PPP1R10) as a PTEN-associated protein. PNUTS directly interacted with the lipid-binding domain (C2 domain) of PTEN and sequestered it in the nucleus. Depletion of PNUTS leads to increased apoptosis and reduced cellular proliferation in a PTEN-dependent manner. PNUTS expression was elevated in certain cancers compared with matched normal tissues. Collectively, our studies reveal PNUTS as a novel PTEN regulator and a likely oncogene.

  8. Significance of oncogenes and tumor suppressor genes in AML prognosis.

    PubMed

    Kavianpour, Maria; Ahmadzadeh, Ahmad; Shahrabi, Saeid; Saki, Najmaldin

    2016-08-01

    Acute myeloid leukemia (AML) is a heterogeneous disorder among hematologic malignancies. Several genetic alterations occur in this disease, which cause proliferative progression, reducing differentiation and apoptosis in leukemic cells as well as increasing their survival. In the genetic study of AML, genetic translocations, gene overexpression, and mutations effective upon biology and pathogenesis of this disease have been recognized. Proto-oncogenes and tumor suppressor genes, which are important in normal development of myeloid cells, are involved in the regulation of cell cycle and apoptosis, undergo mutation in this type of leukemia, and are effective in prognosis of AML subtypes. This review deals with these genes, the assessment of which can be important in the diagnosis and prognosis of patients as well as therapeutic outcome. PMID:27179964

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

    PubMed

    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.

  10. Structural Effects of Oncogenic PI3K alpha Mutations

    SciTech Connect

    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.

  11. Characterization and developmental expression of a Drosophila ras oncogene.

    PubMed Central

    Mozer, B; Marlor, R; Parkhurst, S; Corces, V

    1985-01-01

    We cloned a Drosophila melanogaster ras gene (Dmras64B) on the basis of its homology to the ras oncogen from Harvey murine sarcoma virus. This gene mapped at chromosomal position 64B on the left arm of the third chromosome. Sequencing of Dmras64B revealed extensive amino acid homology with the proteins encoded by the human and Saccharomyces cerevisiae ras genes. The coding region of the Drosophila gene is interrupted by two introns located in different positions with respect to its human counterpart. Dmras64B encodes three different RNAs (1.6, 2.1, and 2.6 kilobases long) that are constantly expressed throughout the development of the fly. Images PMID:3921827

  12. PNUTS functions as a proto-oncogene by sequestering PTEN

    PubMed Central

    Kavela, Sridhar; Shinde, Swapnil R; Ratheesh, Raman; Viswakalyan, Kotapalli; Bashyam, Murali D; Gowrishankar, Swarnalata; Vamsy, Mohana; Pattnaik, Sujit; Rao, Subramanyeshwar; Sastry, Regulagadda A; Srinivasulu, Mukta; Chen, Junjie; Maddika, Subbareddy

    2012-01-01

    PTEN is a well-defined tumor suppressor gene that antagonizes the PI3K/Akt pathway to regulate a multitude of cellular processes such as survival, growth, motility, invasiveness and angiogenesis. While the functions of PTEN have been studied extensively, the regulation of its activity during normal and disease conditions still remains incompletely understood. In this study, we identified the protein phosphatase-1 nuclear targeting subunit PNUTS (PPP1R10) as a PTEN associated protein. PNUTS directly interacted with the lipid-binding domain (C2 domain) of PTEN and sequestered it in the nucleus. Depletion of PNUTS leads to increased apoptosis and reduced cellular proliferation in a PTEN-dependent manner. PNUTS expression was elevated in certain cancers compared to matched normal tissues. Collectively, our studies reveal PNUTS as a novel PTEN regulator and a likely oncogene. PMID:23117887

  13. Induction of promyelocytic leukemia (PML) oncogenic domains (PODs) by papillomavirus

    SciTech Connect

    Nakahara, Tomomi; Lambert, Paul F.

    2007-09-30

    Promyelocytic leukemia oncogenic domains (PODs), also called nuclear domain 10 (ND10), are subnuclear structures that have been implicated in a variety of cellular processes as well as the life cycle of DNA viruses including papillomaviruses. In order to investigate the interplay between papillomaviruses and PODs, we analyzed the status of PODs in organotypic raft cultures of human keratinocytes harboring HPV genome that support the differentiation-dependent HPV life cycle. The number of PODs per nucleus was increased in the presence of HPV genomes selectively within the poorly differentiated layers but was absent in the terminally differentiated layers of the stratified epithelium. This increase in PODs was correlated with an increase in abundance of post-translationally modified PML protein. Neither the E2-dependent transcription nor viral DNA replication was reliant upon the presence of PML. Implications of these findings in terms of HPV's interaction with its host are discussed.

  14. Tumor-Derived Exosomes in Oncogenic Reprogramming and Cancer Progression

    PubMed Central

    Saleem, Sarmad N; Abdel-Mageed, Asim B

    2014-01-01

    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. PMID:25156068

  15. SOCS1 in cancer: An oncogene and a tumor suppressor.

    PubMed

    Beaurivage, Claudia; Champagne, Audrey; Tobelaim, William S; Pomerleau, Véronique; Menendez, Alfredo; Saucier, Caroline

    2016-06-01

    The Suppressor Of Cytokine Signaling 1 (SOCS1) has been extensively investigated in immune cells where it works as a potent inhibitor of inflammation by negative feedback regulation of the cytokine-activated JAK-STAT signaling pathways. SOCS1 is also recognized as a tumor suppressor in numerous cancers and its critical functional relevance in non-immune cells, including epithelial cells, has just begun to emerge. Most notably, conflicting results from clinical and experimental studies suggest that SOCS1 may function as either a tumor suppressor or a tumor promoter, in a cell context-dependent manner. Here, we present an overview of the mechanisms underlying SOCS1 function as a tumor suppressor and discuss the emerging evidences of SOCS1 activity as an oncogene. PMID:26811119

  16. Frequently rearranged in advanced T-cell lymphomas-1 demonstrates oncogenic properties in prostate cancer

    PubMed Central

    Zhang, Wei; Xiong, Hua; Zou, Yanmei; Xu, Sanpeng; Quan, Lanping; Yuan, Xianglin; Xu, Ningzhi; Wang, Yihua

    2016-01-01

    Prostate cancer is the fifth most common cause of cancer-associated mortality for males worldwide. Although dysregulation of the β-catenin/T-cell factor (TCF) pathway has been previously reported in prostate cancer, the mechanisms underlying this process remain unknown. Frequently rearranged in advanced T-cell lymphomas-1 (FRAT1) functions as a positive regulator of the β-catenin/TCF signaling pathway. However, to the best of our knowledge, the molecular association between FRAT1 and the β-catenin/TCF pathway in prostate cancer has not been investigated. In the present study, FRAT1 expression was analyzed in normal prostate tissues and prostate adenocarcinoma samples using publicly available databases, a commercial tissue microarray and immunohistochemistry techniques. In addition, FRAT1 expression levels were altered by overexpression or RNA interference-mediated depletion in prostate cancer cells. The effects of FRAT1 expression on tumor growth were determined using cell growth curves in vitro and xenografts in nude mice in vivo. The effects of FRAT1 on β-catenin/TCF activity were measured using the TOPFLASH reporter assay. FRAT1 was expressed exclusively in the nuclei of normal prostate basal cells, and nuclear FRAT1 was detected in 68% (40/59) of prostate adenocarcinoma samples. In addition, FRAT1 activated the TCF luciferase reporter gene promoter in prostate cancer cells, and was observed to promote the growth of prostate cancer cells in vitro. Furthermore, FRAT1 expression was sufficient to transform NIH3T3 mouse embryonic fibroblast cells and lead to tumor formation in vivo. These results suggest that FRAT1 demonstrates oncogenic properties in prostate cancer, potentially by suppressing the inhibitory effect of nuclear glycogen synthase 3β against β-catenin/TCF activity, thus activating the Wnt/β-catenin signaling pathway and promoting cell growth. PMID:27599661

  17. Frequently rearranged in advanced T‑cell lymphomas‑1 demonstrates oncogenic properties in prostate cancer.

    PubMed

    Zhang, Wei; Xiong, Hua; Zou, Yanmei; Xu, Sanpeng; Quan, Lanping; Yuan, Xianglin; Xu, Ningzhi; Wang, Yihua

    2016-10-01

    Prostate cancer is the fifth most common cause of cancer‑associated mortality for males worldwide. Although dysregulation of the β‑catenin/T‑cell factor (TCF) pathway has been previously reported in prostate cancer, the mechanisms underlying this process remain unknown. Frequently rearranged in advanced T‑cell lymphomas‑1 (FRAT1) functions as a positive regulator of the β‑catenin/TCF signaling pathway. However, to the best of our knowledge, the molecular association between FRAT1 and the β‑catenin/TCF pathway in prostate cancer has not been investigated. In the present study, FRAT1 expression was analyzed in normal prostate tissues and prostate adenocarcinoma samples using publicly available databases, a commercial tissue microarray and immunohistochemistry techniques. In addition, FRAT1 expression levels were altered by overexpression or RNA interference‑mediated depletion in prostate cancer cells. The effects of FRAT1 expression on tumor growth were determined using cell growth curves in vitro and xenografts in nude mice in vivo. The effects of FRAT1 on β‑catenin/TCF activity were measured using the TOPFLASH reporter assay. FRAT1 was expressed exclusively in the nuclei of normal prostate basal cells, and nuclear FRAT1 was detected in 68% (40/59) of prostate adenocarcinoma samples. In addition, FRAT1 activated the TCF luciferase reporter gene promoter in prostate cancer cells, and was observed to promote the growth of prostate cancer cells in vitro. Furthermore, FRAT1 expression was sufficient to transform NIH3T3 mouse embryonic fibroblast cells and lead to tumor formation in vivo. These results suggest that FRAT1 demonstrates oncogenic properties in prostate cancer, potentially by suppressing the inhibitory effect of nuclear glycogen synthase 3β against β‑catenin/TCF activity, thus activating the Wnt/β‑catenin signaling pathway and promoting cell growth. PMID:27599661

  18. Intrinsic Structural Disorder Confers Cellular Viability on Oncogenic Fusion Proteins

    PubMed Central

    Hegyi, Hedi; Buday, László; Tompa, Peter

    2009-01-01

    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. PMID:19888473

  19. Class I PI3K in oncogenic cellular transformation

    PubMed Central

    Zhao, Li; Vogt, Peter K.

    2009-01-01

    Class I phosphoinositide 3-kinase (PI3K) is a dimeric enzyme, consisting of a catalytic and a regulatory subunit. The catalytic subunit occurs in four isoforms designated as p110α, p110β, p110γ and p110δ. These combine with several regulatory subunits; for p110α, β and δ the standard regulatory subunit is p85, for p110γ it is p101. PI3Ks play important roles in human cancer. PIK3CA, the gene encoding p110α, is mutated frequently in common cancers, including carcinoma of the breast, prostate, colon and endometrium. Eighty percent of these mutations are represented by one of three amino acid substitutions in the helical or kinase domains of the enzyme. The mutant p110α shows a gain of function in enzymatic and signaling activity and is oncogenic in cell culture and in animal model systems. Structural and genetic data suggest that the mutations affect regulatory inter- and intramolecular interactions and support the conclusion that there are at least two molecular mechanisms for the gain-of-function in p110α. One of these mechanisms operates largely independently of binding to p85, the other abolishes the requirement for an interaction with Ras. The non-alpha isoforms of p110 do not show cancer-specific mutations. However, they are often differentially expressed in cancer and, in contrast to p110α, wild-type non-alpha isoforms of p110 are oncogenic when overexpressed in cell culture. The isoforms of p110 have become promising drug targets. Isoform-selective inhibitors have been identified. Inhibitors that target exclusively the cancer-specific mutants of p110α constitute an important goal and challenge for current drug development. PMID:18794883

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

    PubMed

    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.

  1. Oncogenes in human testicular cancer: DNA and RNA studies.

    PubMed Central

    Peltomäki, P.; Alfthan, O.; de la Chapelle, A.

    1991-01-01

    Oncogene dosage and expression were studied in 16 testicular neoplasms, 14 of germ cell and two of non-germ cell origin. In comparison with normal DNA, tumour DNA of a total of eight patients (seven with germ cell neoplasm and one with testicular lymphoma) showed increased dosages of KRAS2, PDGFA, EGFR, MET and PDGFB. The most frequent (occurring in six tumours) and prominent (up to 3-4-fold) increases were detected in the dosages of KRAS2 (on chromosome 12p) and PDGFA (chromosome 7p), relative to a reference locus from chromosome 2. Importantly, there was a similar increase in 12p dosage in general in these tumours, suggesting the presence of the characteristic isochromosome 12p marker. On the contrary, possible 7p polysomy (assessed by molecular methods) did not explain the PDGFA (or EGFR) changes in all cases. NRAS, MYCN, CSFIR, MYB, MYC, ABL, HRASI, TP53, and ERBB2 did not reveal any consistent alterations in tumour DNA. In RNA dot blot assays the expression of KRAS2, PDGFA, EGFR, or MYC was generally not increased in the tumour samples when compared to that in normal testicular tissue of the same patients although there was interindividual variation in mRNA levels. It thus appears that while oncogene dosage changes occur in a proportion of testis cancers, they are often part of changes in large chromosomal regions or whole arms and are seldom accompanied by altered expression. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1829952

  2. Selective repression of the oncogene cyclin D1 by the tumor suppressor miR-206 in cancers.

    PubMed

    Elliman, S J; Howley, B V; Mehta, D S; Fearnhead, H O; Kemp, D M; Barkley, L R

    2014-01-01

    MicroRNAs (miRNAs) are deregulated in cancer and have been shown to exhibit both oncogenic and tumor suppressive functions. Although the functional effects of several miRNAs have been elucidated, those of many remain to be discovered. In silico analysis identified microRNA-206 (miR-206) binding sites in the 3'-untranslated regions (3'-UTR) of both the mouse and human CCND1 gene. Cyclin D1 is a recognized oncogene involved in direct phosphorylation of the retinoblastoma (Rb) protein and promoting cell cycle transition from G1 to S. miR-206 specifically binds to the CCND1 3'-UTR and mediates reduction of both cyclin D1 protein and mRNA. Expression of miR-206 induced a G1 arrest and a decrease in cell proliferation in breast cancer cells. Ectopic expression of miRNA-resistant cyclin D1 was able to reverse the miR-206-induced decrease in cell proliferation. Therefore, we identified miR-206 as an activator of cell cycle arrest resulting in a decrease in cell proliferation that is dependent on the inhibition of cyclin D1. Interestingly, prostatic cancer (PCa) cells express low levels of miR-206 resulting in deregulated cyclin D1 expression compared with non-transformed primary prostatic epithelial cells (PrEC). Finally, we demonstrate that cyclin D1 is regulated by miR-206 in PrEC but not in PCa cells and this is due to the absence of a CCND1 3'-UTR in these cells. This suggests that miR-206-based anti-cyclin D1 targeted therapy would be beneficial in cancers where cyclin D1 is overexpressed and contains a 3'-UTR. PMID:25111862

  3. The cell cycle regulator ecdysoneless cooperates with H-Ras to promote oncogenic transformation of human mammary epithelial cells

    PubMed Central

    Bele, Aditya; Mirza, Sameer; Zhang, Ying; Ahmad Mir, Riyaz; Lin, Simon; Kim, Jun Hyun; Gurumurthy, Channabasavaiah Basavaraju; West, William; Qiu, Fang; Band, Hamid; Band, Vimla

    2015-01-01

    The mammalian ortholog of Drosophila ecdysoneless (Ecd) gene product regulates Rb-E2F interaction and is required for cell cycle progression. Ecd is overexpressed in breast cancer and its overexpression predicts shorter survival in patients with ErbB2-positive tumors. Here, we demonstrate Ecd knock down (KD) in human mammary epithelial cells (hMECs) induces growth arrest, similar to the impact of Ecd Knock out (KO) in mouse embryonic fibroblasts. Furthermore, whole-genome mRNA expression analysis of control vs. Ecd KD in hMECs demonstrated that several of the top 40 genes that were down-regulated were E2F target genes. To address the role of Ecd in mammary oncogenesis, we overexpressed Ecd and/or mutant H-Ras in hTERT-immortalized hMECs. Cell cycle analyses revealed hMECs overexpressing Ecd+Ras showed incomplete arrest in G1 phase upon growth factor deprivation, and more rapid cell cycle progression in growth factor-containing medium. Analyses of cell migration, invasion, acinar structures in 3-D Matrigel and anchorage-independent growth demonstrated that Ecd+Ras-overexpressing cells exhibit substantially more dramatic transformed phenotype as compared to cells expressing vector, Ras or Ecd. Under conditions of nutrient deprivation, Ecd+Ras-overexpressing hMECs exhibited better survival, with substantial upregulation of the autophagy marker LC3 both at the mRNA and protein levels. Significantly, while hMECs expressing Ecd or mutant Ras alone did not form tumors in NOD/SCID mice, Ecd+Ras-overexpressing hMECs formed tumors, clearly demonstrating oncogenic cooperation between Ecd and mutant Ras. Collectively, we demonstrate an important co-oncogenic role of Ecd in the progression of mammary oncogenesis through promoting cell survival. PMID:25616580

  4. Trisomy of the Dscr1 gene suppresses early progression of pancreatic intraepithelial neoplasia driven by oncogenic Kras

    SciTech Connect

    Lee, Jang Choon; Shin, Jimin; Baek, Kwan-Hyuck

    2013-10-11

    Highlights: •A single extra copy of Dscr1 restrains progression of PanIN-1A to PanIN-1B lesions. •Dscr1 trisomy attenuates calcineurin–NFAT pathway in neoplastic ductal epithelium. •Dscr1 trisomy leads to upregulation of p15{sup INK4b} in neoplastic ductal epithelium. •A single extra copy of Dscr1 reduces epithelial proliferation in early PanIN lesions. •Dscr1 trisomy may protect Down syndrome individuals from pancreatic cancer. -- Abstract: Individuals with Down syndrome exhibit remarkably reduced incidence of most solid tumors including pancreatic cancer. Multiple mechanisms arising from the genetic complexity underlying Down syndrome has been suggested to contribute to such a broad cancer protection. In this study, utilizing a genetically engineered mouse model of pancreatic cancer, we demonstrate that trisomy of the Down syndrome critical region-1 (Dscr1), an endogenous calcineurin inhibitor localized on chromosome 21, suppresses the progression of pancreatic intraepithelial neoplasia-1A (PanIN-1A) to PanIN-1B lesions without affecting the initiation of PanIN lesions mediated by oncogenic Kras{sup G12D}. In addition, we show that Dscr1 trisomy attenuates nuclear localization of nuclear factor of activated T-cells (NFAT) accompanied by upregulation of the p15{sup Ink4b} tumor suppressor and reduction of cell proliferation in early PanIN lesions. Our data suggest that attenuation of calcineurin–NFAT signaling in neoplastic pancreatic ductal epithelium by a single extra copy of Dscr1 is sufficient to inhibit the progression of early PanIN lesions driven by oncogenic Kras, and thus may be a potential mechanism underlying reduced incidence of pancreatic cancer in Down syndrome individuals.

  5. Hyperactivation of Ha-ras oncogene, but not Ink4a/Arf deficiency, triggers bladder tumorigenesis.

    PubMed

    Mo, Lan; Zheng, Xiaoyong; Huang, Hong-Ying; Shapiro, Ellen; Lepor, Herbert; Cordon-Cardo, Carlos; Sun, Tung-Tien; Wu, Xue-Ru

    2007-02-01

    Although ras is a potent mitogenic oncogene, its tumorigenicity depends on cellular context and cooperative events. Here we show that low-level expression of a constitutively active Ha-ras in mouse urothelium induces simple urothelial hyperplasia that is resistant to progression to full-fledged bladder tumors even in the absence of Ink4a/Arf. In stark contrast, doubling of the gene dosage of the activated Ha-ras triggered early-onset, rapidly growing, and 100% penetrant tumors throughout the urinary tract. Tumor initiation required superseding a rate-limiting step between simple and nodular hyperplasia, the latter of which is marked by the emergence of mesenchymal components and the coactivation of AKT and STAT pathways as well as PTEN inactivation. These results indicate that overactivation of Ha-ras is both necessary and sufficient to induce bladder tumors along a low-grade, noninvasive papillary pathway, and they shed light on the recent findings that ras activation, via point mutation, overexpression, or intensified signaling from FGF receptor 3, occurs in 70%-90% of these tumors in humans. Our results highlight the critical importance of the dosage/strength of Ha-ras activation in dictating its tumorigenicity--a mechanism of oncogene activation not fully appreciated to date. Finally, our results have clinical implications, as inhibiting ras and/or its downstream effectors, such as AKT and STAT3/5, could provide alternative means to treat low-grade, superficial papillary bladder tumors, the most common tumor in the urinary system. PMID:17256055

  6. FOXM1 is a downstream target of LPA and YAP oncogenic signaling pathways in high grade serous ovarian cancer.

    PubMed

    Fan, Qipeng; Cai, Qingchun; Xu, Yan

    2015-09-29

    Lysophosphatidic acid (LPA), a prototypical ligand for G protein coupled receptors, and Forkhead box protein M1 (FOXM1), a transcription factor that regulates expression of a wide array of genes involved in cancer initiation and progression, are two important oncogenic signaling molecules in human epithelial ovarian cancers (EOC). We conducted in vitro mechanistic studies using pharmacological inhibitors, genetic forms of the signaling molecules, and RNAi-mediated gene knock-down to uncover the molecular mechanisms of how these two molecules interact in EOC cells. Additionally, in vivo mouse studies were performed to confirm the functional involvement of FOXM1 in EOC tumor formation and progression. We show for the first time that LPA up-regulates expression of active FOXM1 splice variants in a time- and dose-dependent manner in the human EOC cell lines OVCA433, CAOV3, and OVCAR5. Gi-PI3K-AKT and G12/13-Rho-YAP signaling pathways were both involved in the LPA receptor (LPA1-3) mediated up-regulation of FOXM1 at the transcriptional level. In addition, down-regulation of FOXM1 in CAOV3 xenografts significantly reduced tumor and ascites formation, metastasis, and expression of FOXM1 target genes involved in cell proliferation, migration, or invasion. Collectively, our data link the oncolipid LPA, the oncogene YAP, and the central regulator of cell proliferation/mutagenesis FOXM1 in EOC cells. Moreover, these results provide further support for the importance of these pathways as potential therapeutic targets in EOC. PMID:26299613

  7. Mitogen-activated protein kinase phosphatase-3 is a tumor promoter target in initiated cells that express oncogenic Ras.

    PubMed

    Warmka, Janel K; Mauro, Laura J; Wattenberg, Elizabeth V

    2004-08-01

    We have capitalized on the unique properties of the skin tumor promoter palytoxin, which does not activate protein kinase C, to investigate alternative mechanisms by which major signaling molecules can be modulated during carcinogenesis. We report here that palytoxin activates extracellular signal-regulated kinase (ERK) through a novel mechanism that involves inactivation of an ERK phosphatase in keratinocytes derived from initiated mouse skin (308 cells). Use of U0126 revealed that palytoxin requires the ERK kinase MEK to stimulate ERK activity, although palytoxin did not activate MEK. We found that 308 keratinocytes highly express mitogen-activated protein kinase phosphatase-3 (MKP-3), which selectively inactivates ERK. Palytoxin induced the loss of MKP-3 in a manner that corresponded to increased ERK phosphorylation. Complementary studies showed that sustained expression of exogenous MKP-3 inhibited palytoxin-stimulated ERK activation. As is characteristic of initiated keratinocytes, 308 cells express activated H-Ras. To investigate whether expression of oncogenic Ras is key to palytoxin-stimulated ERK activation, we determined how palytoxin affected ERK and MKP-3 in MCF10A human breast epithelial cells and in H-ras MCF10A cells, which stably express activated H-Ras. Palytoxin did not affect ERK activity in MCF10A cells, which had no detectable MKP-3. Like 308 cells, H-ras MCF10A cells highly express MKP-3. Strikingly, palytoxin stimulated ERK activity and induced a corresponding loss of MKP-3 in H-ras MCF10A cells. These studies indicate that in initiated cells palytoxin unleashes ERK activity by down-regulating MKP-3, an ERK inhibitor, and further suggest that MKP-3 may be a vulnerable target in cells that express oncogenic Ras.

  8. Glioma-associated endothelial cells show evidence of replicative senescence.

    PubMed

    Charalambous, Christiana; Virrey, Jenilyn; Kardosh, Adel; Jabbour, Mark N; Qazi-Abdullah, Lubna; Pen, Ligaya; Zidovetzki, Raphael; Schönthal, Axel H; Chen, Thomas C; Hofman, Florence M

    2007-04-01

    The innately programmed process of replicative senescence has been studied extensively with respect to cancer, but primarily from the perspective of tumor cells overcoming this stringent innate barrier and acquiring the capacity for unlimited proliferation. In this study, we focus on the potential role of replicative senescence affecting the non-transformed endothelial cells of the blood vessels within the tumor microenvironment. Based on the well-documented aberrant structural and functional features of blood vessels within solid tumors, we hypothesized that tumor-derived factors may lead to premature replicative senescence in tumor-associated brain endothelial cells (TuBEC). We show here that glioma tissue, but not normal brain tissue, contains cells that express the signature of replicative senescence, senescence-associated beta-galactosidase (SA-beta-gal), on CD31-positive endothelial cells. Primary cultures of human TuBEC stain for SA-beta-gal and exhibit characteristics of replicative senescence, including increased levels of the cell cycle inhibitors p21 and p27, increased resistance to cytotoxic drugs, increased growth factor production, and inability to proliferate. These data provide the first demonstration that tumor-derived brain endothelial cells may have reached an end-stage of differentiation known as replicative senescence and underscore the need for anti-angiogenic therapies to target this unique tumor-associated endothelial cell population.

  9. Glioma-associated endothelial cells show evidence of replicative senescence

    SciTech Connect

    Charalambous, Christiana; Virrey, Jenilyn; Kardosh, Adel; Jabbour, Mark N.; Qazi-Abdullah, Lubna; Pen, Ligaya; Zidovetzki, Raphael; Schoenthal, Axel H.; Chen, Thomas C.; Hofman, Florence M. . E-mail: hofman@usc.edu

    2007-04-01

    The innately programmed process of replicative senescence has been studied extensively with respect to cancer, but primarily from the perspective of tumor cells overcoming this stringent innate barrier and acquiring the capacity for unlimited proliferation. In this study, we focus on the potential role of replicative senescence affecting the non-transformed endothelial cells of the blood vessels within the tumor microenvironment. Based on the well-documented aberrant structural and functional features of blood vessels within solid tumors, we hypothesized that tumor-derived factors may lead to premature replicative senescence in tumor-associated brain endothelial cells (TuBEC). We show here that glioma tissue, but not normal brain tissue, contains cells that express the signature of replicative senescence, senescence-associated {beta}-galactosidase (SA-{beta}-gal), on CD31-positive endothelial cells. Primary cultures of human TuBEC stain for SA-{beta}-gal and exhibit characteristics of replicative senescence, including increased levels of the cell cycle inhibitors p21 and p27, increased resistance to cytotoxic drugs, increased growth factor production, and inability to proliferate. These data provide the first demonstration that tumor-derived brain endothelial cells may have reached an end-stage of differentiation known as replicative senescence and underscore the need for anti-angiogenic therapies to target this unique tumor-associated endothelial cell population.

  10. EG-08IDH MUTATIONS IN GLIOMAS ASSOCIATED WITH ENCHONDROMATOSIS

    PubMed Central

    Nicholas, M. Kelly; Joseph, Loren; Venneti, Sriram; Daher, Ahmad; Pytel, Peter

    2014-01-01

    The enchondromatoses, Ollier's disease and Maffucci syndrome, are non-heritable developmental disorders characterized by multiple enchondromas (Olllier's) in association with hemangiomas (Maffucci). Glial neoplasms are reported in both disorders but a pathogenic mechanism underlying this association has not been identified. We report a case of anaplastic astrocytoma in a 23 year old man with Maffucci syndrome whose tumor carried a substitution mutation of arginine for cysteine at position 132 (R132C) of the isocitrate dehydrogenase 1 (IDH1) protein. This mutation, commonly found in Maffucci-associated enchondromas and hemangiomas, was not detected on routine immunohistochemical (IHC) analysis of the astrocytoma using the R132H mutation-specific antibody, commonly applied in clinical laboratories. The R132C mutation was detected by polymerase chain reaction (PCR) and subsequently confirmed using a SNaPshot assay. Because somatic mosaic IDH mutations are associated with enchondromas and hemangiomas in Maffucci syndrome, we looked for the R132C mutation in a hemangioma, peripheral blood mononuclear cells (PBMNC) and histologically normal brain surrounding the tumor from this patient. The mutation was present in the hemangioma, absent in PBMNC, and present in 2% of alleles in ‘normal’ brain. The low level in surrounding brain tissue is consistent with tumor cell infiltration, not mosaicism, as a S173T p53 mutation in the tumor showed similar results. Using IHC, we further demonstrated that the mutant IDH1 protein in this glioma functions as an oncometabolite. Two repressive histone trimethylation marks were strongly positive in the tumor, supporting a role for 2-hydroxyglutarate in the inhibition of histone demethylation. Together, these data demonstrate that an IDH1 mutation common in enchodromatoses underlies the association of glial tumors reported in both Ollier's disease and Maffucci syndrome.

  11. Sequence comparison in the crossover region of an oncogenic avian retrovirus recombinant and its nononcogenic parent: Genetic regions that control growth rate and oncogenic potential

    SciTech Connect

    Tsichlis, P.N.; Donehower, L.; Hager, G.; Zeller, N.; Malavarca, R.; Astrin, S.; Skalka, A.M.

    1982-11-01

    NTRE is an avian retrovirus recombinant of the endogeneous nononcogenic Rous-associated virus-0 (RAV-0) and the oncogenic, exogeneous, transformation-defective (td) Prague strain of Rous sarcoma virus B (td-PrRSV-B). Oligonucleotide mapping had shown that the recombinant virus is indistinguishable from its RAV-0 parent except for the 3'-end sequences, which were derived from td-PrRSV-B. However, the virus exhibits properties which are typical of an exogenous virus: it grows to high titers in tissue culture, and it is oncogenic in vivo. To accurately define the genetic region responsible for these properties, the authors determined the nucleotide sequences of the recombinant and its RAV-0 parent by using molecular clones of their DNA. These were compared with sequences already available for PrRSV-C, a virus closely related to the exogenous parent td-PrRSV-B. The results suggested that the crossover event which generated NTRE 7 took place in a region -501 to -401 nucleotides from the 3' end of the td-PrRSV parental genome and that sequences to the right of the recombination region were responsible for its growth properties and oncogenic potential. Since the exogenous-virus-specific sequences are expected to be missing from transformation-defective mutants of the Schmidt-Ruppin strain of RSV, which, like other exogeneous viruses, grow to high tiers in tissue culture and are oncogenic in vivo, the authors concluded that the growth properties and oncogenic potential of the exogeneous viruses are determined by sequences in the U3 region of the long terminal repeat. However, the authors propose that the exogeneous-virus-specific region may play a role in determining the oncogenic spectrum of a given oncogenic virus.

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

    PubMed

    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. Multiple oncogenic mutations and clonal relationship in spatially distinct benign human epidermal tumors

    PubMed Central

    Hafner, Christian; Toll, Agustí; Fernández-Casado, Alejandro; Earl, Julie; Marqués, Miriam; Acquadro, Francesco; Méndez-Pertuz, Marinela; Urioste, Miguel; Malats, Núria; Burns, Julie E.; Knowles, Margaret A.; Cigudosa, Juan C.; Hartmann, Arndt; Vogt, Thomas; Landthaler, Michael; Pujol, Ramón M.; Real, Francisco X.

    2010-01-01

    Malignant tumors result from the accumulation of genetic alterations in oncogenes and tumor suppressor genes. Much less is known about the genetic changes in benign tumors. Seborrheic keratoses (SK) are very frequent benign human epidermal tumors without malignant potential. We performed a comprehensive mutational screen of genes in the FGFR3-RAS-MAPK and phosphoinositide 3-kinase (PI3K)-AKT pathways from 175 SK, including multiple lesions from each patient. SK commonly harbored multiple bona fide oncogenic mutations in FGFR3, PIK3CA, KRAS, HRAS, EGFR, and AKT1 oncogenes but not in tumor suppressor genes TSC1 and PTEN. Despite the occurrence of oncogenic mutations and the evidence for downstream ERK/MAPK and PI3K pathway signaling, we did not find induction of senescence or a DNA damage response. Array comparative genomic hybridization (aCGH) analysis revealed that SK are genetically stable. The pattern of oncogenic mutations and X chromosome inactivation departs significantly from randomness and indicates that spatially independent lesions from a given patient share a clonal relationship. Our findings show that multiple oncogenic mutations in the major signaling pathways involved in cancer are not sufficient to drive malignant tumor progression. Furthermore, our data provide clues on the origin and spread of oncogenic mutations in tissues, suggesting that apparently independent (multicentric) adult benign tumors may have a clonal origin. PMID:21078999

  14. Practical use of advanced mouse models for lung cancer.

    PubMed

    Safari, Roghaiyeh; Meuwissen, Ralph

    2015-01-01

    To date a variety of non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) mouse models have been developed that mimic human lung cancer. Chemically induced or spontaneous lung cancer in susceptible inbred strains has been widely used, but the more recent genetically engineered somatic mouse models recapitulate much better the genotype-phenotype correlations found in human lung cancer. Additionally, improved orthotopic transplantation of primary human cancer tissue fragments or cells into lungs of immune-compromised mice can be valuable tools for preclinical research such as antitumor drug tests. Here we give a short overview of most somatic mouse models for lung cancer that are currently in use. We accompany each different model with a description of its practical use and application for all major lung tumor types, as well as the intratracheal injection or direct injection of fresh or freeze-thawed tumor cells or tumor cell lines into lung parenchyma of recipient mice. All here presented somatic mouse models are based on the ability to (in) activate specific alleles at a time, and in a tissue-specific cell type, of choice. This spatial-temporal controlled induction of genetic lesions allows the selective introduction of main genetic lesions in an adult mouse lung as found in human lung cancer. The resulting conditional somatic mouse models can be used as versatile powerful tools in basic lung cancer research and preclinical translational studies alike. These distinctively advanced lung cancer models permit us to investigate initiation (cell of origin) and progression of lung cancer, along with response and resistance to drug therapy. Cre/lox or FLP/frt recombinase-mediated methods are now well-used techniques to develop tissue-restricted lung cancer in mice with tumor-suppressor gene and/or oncogene (in)activation. Intranasal or intratracheal administration of engineered adenovirus-Cre or lentivirus-Cre has been optimized for introducing Cre

  15. DNA damage and repair in oncogenic transformation by heavy ion radiation

    NASA Technical Reports Server (NTRS)

    Yang, T. C.; Mei, M.; George, K. A.; Craise, L. M.

    1996-01-01

    Energetic heavy ions are present in galactic cosmic rays and solar particle events. One of the most important late effects in risk assessment is carcinogenesis. We have studied the carcinogenic effects of heavy ions at the cellular and molecular levels and have obtained quantitative data on dose-response curves and on the repair of oncogenic lesions for heavy particles with various charges and energies. Studies with repair inhibitors and restriction endonucleases indicated that for oncogenic transformation DNA is the primary target. Results from heavy ion experiments showed that the cross section increased with LET and reached a maximum value of about 0.02 micrometer2 at about 500 keV/micrometer. This limited size of cross section suggests that only a fraction of cellular genomic DNA is important in radiogenic transformation. Free radical scavengers, such as DMSO, do not give any effect on induction of oncogenic transformation by 600 MeV/u iron particles, suggesting most oncogenic damage induced by high-LET heavy ions is through direct action. Repair studies with stationary phase cells showed that the amount of reparable oncogenic lesions decreased with an increase of LET and that heavy ions with LET greater than 200 keV/micrometer produced only irreparable oncogenic damage. An enhancement effect for oncogenic transformation was observed in cells irradiated by low-dose-rate argon ions (400 MeV/u; 120 keV/micrometer). Chromosomal aberrations, such as translocation and deletion, but not sister chromatid exchange, are essential for heavy-ion-induced oncogenic transformation. The basic mechanism(s) of misrepair of DNA damage, which form oncogenic lesions, is unknown.

  16. DNA damage and repair in oncogenic transformation by heavy ion radiation

    NASA Astrophysics Data System (ADS)

    Yang, T. C.; Mei, M.; George, K. A.; Craise, L. M.

    Energetic heavy ions are present in galactic cosmic rays and solar particle events. One of the most important late effects in risk assessment is carcinogenesis. We have studied the carcinogenic effects of heavy ions at the cellular and molecular levels and have obtained quantitative data on dose-response curves and on the repair of oncogenic lesions for heavy particles with various charges and energies. Studies with repair inhibitors and restriction endonucleases indicated that for oncogenic transformation DNA is the primary target. Results from heavy ion experiments showed that the cross section increased with LET and reached a maximum value of about 0.02 mum^2 at about 500 keV/mum. This limited size of cross section suggests that only a fraction of cellular genomic DNA is important in radiogenic transformation. Free radical scavengers, such as DMSO, do not give any effect on induction of oncogenic transformation by 600 MeV/u iron particles, suggesting most oncogenic damage induced by high-LET heavy ions is through direct action. Repair studies with stationary phase cells showed that the amount of reparable oncogenic lesions decreased with an increase of LET and that heavy ions with LET greater than 200 keV/mum produced only irreparable oncogenic damage. An enhancement effect for oncogenic transformation was observed in cells irradiated by low-dose-rate argon ions (400 MeV/u; 120 keV/mum). Chromosomal aberrations, such as translocation and deletion, but not sister chromatid exchange, are essential for heavy-ion-induced oncogenic transformation. The basic mechanism(s) of misrepair of DNA damage, which form oncogenic lesions, is unknown.

  17. Characterization of the NTRK1 genomic region involved in chromosomal rearrangements generating TRK oncogenes

    SciTech Connect

    Greco, A.; Mariani, C.; Miranda, C.; Pagliardini, S.; Pierotti, M.A. )

    1993-11-01

    TRK oncogenes are created by chromosomal rearrangements linking the tyrosine-kinase domain of the NTRK1 gene (encoding one of the receptors for the nerve growth factor) to foreign activating sequences. TRK oncogenes are frequently detected in human papillary thyroid carcinoma, as a result of rearrangements involving at least three different activating genes. The authors have found that the rearrangements creating all the TRK oncogenes so far characterized fall within a 2.9-kb XbaI/SmaI restriction fragment of the NTRK1 gene. Here they report the nucleotide sequence and the exon organization of this fragment. 13 refs., 2 figs.

  18. Mouse Curve Biometrics

    SciTech Connect

    Schulz, Douglas A.

    2007-10-08

    A biometric system suitable for validating user identity using only mouse movements and no specialized equipment is presented. Mouse curves (mouse movements with little or no pause between them) are individually classied and used to develop classication histograms, which are representative of an individual's typical mouse use. These classication histograms can then be compared to validate identity. This classication approach is suitable for providing continuous identity validation during an entire user session.

  19. Building a Brainier Mouse.

    ERIC Educational Resources Information Center

    Tsien, Joe Z.

    2000-01-01

    Describes a genetic engineering project to build an intelligent mouse. Cites understanding the molecular basis of learning and memory as a very important step. Concludes that while science will never create a genius mouse that plays the stock market, it can turn a mouse into a quick learner with a better memory. (YDS)

  20. Cadmium-induced cell transformation and tumorigenesis are associated with transcriptional activation of c-fos, c-jun, and c-myc proto-oncogenes: role of cellular calcium and reactive oxygen species.

    PubMed

    Joseph, P; Muchnok, T K; Klishis, M L; Roberts, J R; Antonini, J M; Whong, W Z; Ong, T

    2001-06-01

    The molecular mechanisms of carcinogenesis by cadmium were studied using BALB/c-3T3 cell transformation and nude mouse tumorigenesis models. BALB/c-3T3 cells transformed with cadmium chloride were subcutaneously injected into nude mice to develop tumors and the cell lines derived from these tumors were used in the present study. The proto-oncogenes c-fos and c-jun were overexpressed in 100% (10 out of 10) of the cell lines, while a statistically significant overexpression of c-myc was observed in 40% (4 out of 10) of the cell lines. Analysis of tumor cells stained with fluorescent dyes specific for reactive oxygen species revealed that these cells possessed markedly higher levels of superoxide anion and hydrogen peroxide compared with the nontransformed cells. Similarly, the intracellular calcium level was higher in the tumor cells compared with the nontransformed cells. Overexpression of the proto-oncogenes in these cells was blocked by treating the cells with superoxide dismutase, catalase, and 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra acetoxy methyl ester (BAPTA/AM), which are scavengers of superoxide anion, hydrogen peroxide, and calcium, respectively. This confirmed that the overexpression of the proto-oncogenes in the tumor cells required elevated intracellular levels of reactive oxygen species and calcium. In addition to the scavengers of reactive oxygen species and calcium, inhibitors specific for transcription (actinomycin D), protein kinase C (RO-31-8220), and MAP kinase (PD 98059) also blocked the cadmium-induced overexpression of the proto-oncogenes in the tumor cells. Exposure of the nontransformed BALB/c-3T3 cells to 20 microM cadmium chloride for 1 h caused elevated intracellular levels of superoxide anion, hydrogen peroxide, and calcium, with corresponding increases in the expression levels of c-fos, c-jun, and c-myc. As in the case of the tumor cells, treating the nontransformed cells with the various modulators prior to their exposure to

  1. Oncogenically active MYD88 mutations in human lymphoma

    PubMed Central

    Ngo, Vu N.; Young, Ryan M.; Schmitz, Roland; Jhavar, Sameer; Xiao, Wenming; Lim, Kian-Huat; Kohlhammer, Holger; Xu, Weihong; Yang, Yandan; Zhao, Hong; Shaffer, Arthur L.; Romesser, Paul; Wright, George; Powell, John; Rosenwald, Andreas; Muller-Hermelink, Hans Konrad; Ott, German; Gascoyne, Randy D.; Connors, Joseph M.; Rimsza, Lisa M.; Campo, Elias; Jaffe, Elaine S.; Delabie, Jan; Smeland, Erlend B.; Fisher, Richard I.; Braziel, Rita M.; Tubbs, Raymond R.; Cook, J. R.; Weisenburger, Denny D.; Chan, Wing C.; Staudt, Louis M.

    2016-01-01

    The activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) remains the least curable form of this malignancy despite recent advances in therapy1. Constitutive nuclear factor (NF)-κB and JAK kinase signalling promotes malignant cell survival in these lymphomas, but the genetic basis for this signalling is incompletely understood. Here we describe the dependence of ABC DLBCLs on MYD88, an adaptor protein that mediates toll and interleukin (IL)-1 receptor signalling2,3, and the discovery of highly recurrent oncogenic mutations affecting MYD88 in ABC DLBCL tumours. RNA interference screening revealed that MYD88 and the associated kinases IRAK1 and IRAK4 are essential for ABC DLBCL survival. High-throughput RNA resequencing uncovered MYD88 mutations in ABC DLBCL lines. Notably, 29% of ABC DLBCL tumours harboured the same amino acid substitution, L265P, in the MYD88 Toll/IL-1 receptor (TIR) domain at an evolutionarily invariant residue in its hydrophobic core. This mutation was rare or absent in other DLBCL subtypes and Burkitt’s lymphoma, but was observed in 9% of mucosa-associated lymphoid tissue lymphomas. At a lower frequency, additional mutations were observed in the MYD88 TIR domain, occurring in both the ABC and germinal centre B-cell-like (GCB) DLBCL subtypes. Survival of ABC DLBCL cells bearing the L265P mutation was sustained by the mutant but not the wild-type MYD88 isoform, demonstrating that L265P is a gain-of-function driver mutation. The L265P mutant promoted cell survival by spontaneously assembling a protein complex containing IRAK1 and IRAK4, leading to IRAK4 kinase activity, IRAK1 phosphorylation, NF-κB signalling, JAK kinase activation of STAT3, and secretion of IL-6, IL-10 and interferon-β. Hence, theMYD88 signalling pathway is integral to the pathogenesis of ABC DLBCL, supporting the development of inhibitors of IRAK4 kinase and other components of this pathway for the treatment of tumours bearing oncogenic MYD88 mutations

  2. Role of DLC1 tumor suppressor gene and MYC oncogene in pathogenesis of human hepatocellular carcinoma: potential prospects for combined targeted therapeutics (review).

    PubMed

    Zimonjic, Drazen B; Popescu, Nicholas C

    2012-08-01

    Hepatocellular carcinoma (HCC) is the third leading cause of cancer death, and its incidence is increasing worldwide in an alarming manner. The development of curative therapy for advanced and metastatic HCC is a high clinical priority. The HCC genome is complex and heterogeneous; therefore, the identification of recurrent genomic and related gene alterations is critical for developing clinical applications for diagnosis, prognosis and targeted therapy of the disease. This article focuses on recent research progress and our contribution in identifying and deciphering the role of defined genetic alterations in the pathogenesis of HCC. A significant number of genes that promote or suppress HCC cell growth have been identified at the sites of genomic reorganization. Notwithstanding the accumulation of multiple genetic alterations, highly recurrent changes on a single chromosome can alter the expression of oncogenes and tumor suppressor genes (TSGs) whose deregulation may be sufficient to drive the progression of normal hepatocytes to malignancy. A distinct and highly recurrent pattern of genomic imbalances in HCC includes the loss of DNA copy number (associated with loss of heterozygosity) of TSG-containing chromosome 8p and gain of DNA copy number or regional amplification of protooncogenes on chromosome 8q. Even though 8p is relatively small, it carries an unusually large number of TSGs, while, on the other side, several oncogenes are dispersed along 8q. Compelling evidence demonstrates that DLC1, a potent TSG on 8p, and MYC oncogene on 8q play a critical role in the pathogenesis of human HCC. Direct evidence for their role in the genesis of HCC has been obtained in a mosaic mouse model. Knockdown of DLC1 helps MYC in the induction of hepatoblast transformation in vitro, and in the development of HCC in vivo. Therapeutic interventions, which would simultaneously target signaling pathways governing both DLC1 and MYC functions in hepatocarcinogenesis, could

  3. A Compendium of the Mouse Mammary Tumor Biologist: From the Initial Observations in the House Mouse to the Development of Genetically Engineered Mice

    PubMed Central

    Cardiff, Robert D.; Kenney, Nicholas

    2011-01-01

    For over a century, mouse mammary tumor biology and the associated mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration in 1984. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skill sets to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this compendium is to extend an “olive branch” while simultaneously deepen the knowledge of the novice mouse mammary tumor biologist as they journey into a field rich in pathology and genetics spanning several centuries. PMID:20961975

  4. A compendium of the mouse mammary tumor biologist: from the initial observations in the house mouse to the development of genetically engineered mice.

    PubMed

    Cardiff, Robert D; Kenney, Nicholas

    2011-06-01

    For over a century, mouse mammary tumor biology and the associated mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration in 1984. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skill sets to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this compendium is to extend an "olive branch" while simultaneously deepen the knowledge of the novice mouse mammary tumor biologist as they journey into a field rich in pathology and genetics spanning several centuries. PMID:20961975

  5. A compendium of the mouse mammary tumor biologist: from the initial observations in the house mouse to the development of genetically engineered mice.

    PubMed

    Cardiff, Robert D; Kenney, Nicholas

    2011-06-01

    For over a century, mouse mammary tumor biology and the associated mouse mammary tumor virus (MMTV) have served as the foundation for experimental cancer research, in general, and, in particular, experimental breast cancer research. Spontaneous mouse mammary tumors were the basis for studies of the natural history of neoplasia, oncogenic viruses, host responses, endocrinology and neoplastic progression. However, lacking formal proof of a human mammary tumor virus, the preeminence of the mouse model faded in the 1980s. Since the late 1980s, genetically engineered mice (GEM) have proven extremely useful for studying breast cancer and have become the animal model for human breast cancer. Hundreds of mouse models of human breast cancer have been developed since the first demonstration in 1984. The GEM have attracted a new generation of molecular and cellular biologists eager to apply their skill sets to these surrogates of the human disease. Newcomers often enter the field without an appreciation of the origins of mouse mammary tumor biology and the basis for many of the prevailing concepts. Our purpose in writing this compendium is to extend an "olive branch" while simultaneously deepen the knowledge of the novice mouse mammary tumor biologist as they journey into a field rich in pathology and genetics spanning several centuries.

  6. RNF4-Dependent Oncogene Activation by Protein Stabilization.

    PubMed

    Thomas, Jane J; Abed, Mona; Heuberger, Julian; Novak, Rostislav; Zohar, Yaniv; Beltran Lopez, Angela P; Trausch-Azar, Julie S; Ilagan, Ma Xenia G; Benhamou, David; Dittmar, Gunnar; Kopan, Raphael; Birchmeier, Walter; Schwartz, Alan L; Orian, Amir

    2016-09-20

    Ubiquitylation regulates signaling pathways critical for cancer development and, in many cases, targets proteins for degradation. Here, we report that ubiquitylation by RNF4 stabilizes otherwise short-lived oncogenic transcription factors, including β-catenin, Myc, c-Jun, and the Notch intracellular-domain (N-ICD) protein. RNF4 enhances the transcriptional activity of these factors, as well as Wnt- and Notch-dependent gene expression. While RNF4 is a SUMO-targeted ubiquitin ligase, protein stabilization requires the substrate's phosphorylation, rather than SUMOylation, and binding to RNF4's arginine-rich motif domain. Stabilization also involves generation of unusual polyubiquitin chains and docking of RNF4 to chromatin. Biologically, RNF4 enhances the tumor phenotype and is essential for cancer cell survival. High levels of RNF4 mRNA correlate with poor survival of a subgroup of breast cancer patients, and RNF4 protein levels are elevated in 30% of human colon adenocarcinomas. Thus, RNF4-dependent ubiquitylation translates transient phosphorylation signal(s) into long-term protein stabilization, resulting in enhanced oncoprotein activation. PMID:27653698

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

    PubMed

    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.

  8. Control of Tumorigenesis and Chemoresistance by the DEK oncogene

    PubMed Central

    Riveiro-Falkenbach, Erica; Soengas, María S.

    2010-01-01

    Slight modifications of chromatin dynamics can translate into short and large-scale changes in DNA replication and DNA repair. Similarly, promoter usage and accessibility are tightly dependent on chromatin architecture. Consequently, it is perhaps not surprising that factors controlling chromatin organization are frequently deregulated (directly or indirectly) in cancer cells. DEK is emerging as a novel class of DNA topology modulators which can be both targets and effectors of pro-tumorigenic events. The locus containing DEK at chromosome 6p22.3 is amplified or reorganized in multiple cancer types. In addition, DEK can be subject to a variety of tumor-associated transcriptional and post-translational modifications. In turn, DEK can favor cell transformation, at least in part by inhibiting cell differentiation and premature senescence. More recently, DEK has also been linked to the resistance of malignant cells to apoptotic inducers. Interestingly, a fraction of DEK can also bind RNA and affect alternative splicing, further illustrating the pleiotropic roles that this protein may exert in cancer cells. Here we will summarize the current literature regarding the regulation and function(s) of DEK as a proto-oncogene. In addition, the translational relevance of DEK as a putative diagnostic marker and candidate for drug development will also be discussed. PMID:20501624

  9. Copper is required for oncogenic BRAF signaling and tumorigenesis

    PubMed Central

    Brady, Donita C.; Crowe, Matthew S.; Turski, Michelle L.; Hobbs, G. Aaron; Yao, Xiaojie; Chaikuad, Apirat; Knapp, Stefan; Xiao, Kunhong; Campbell, Sharon L.; Thiele, Dennis J.; Counter, Christopher M.

    2014-01-01

    The BRAF kinase is mutated, typically V600E, to induce an active oncogenic state in a large fraction of melanoma, thyroid, hairy cell leukemia, and to a lesser extent, a wide spectrum of other cancers1,2. BRAFV600E phosphorylates and activates the kinases MEK1 and MEK2, which in turn phosphorylate and activate the kinases ERK1 and ERK2, stimulating the MAPK pathway to promote cancer3. Targeting MEK1/2 is proving to be an important therapeutic strategy, as a MEK1/2 inhibitor provides a survival advantage in metastatic melanoma4, which is increased when co-administered with a BRAFV600E inhibitor5. In this regard, we previously found that copper (Cu) influx enhances MEK1 phosphorylation of ERK1/2 through a Cu-MEK1 interaction6. We now show that genetic loss of the high affinity Cu transporter Ctr1 or mutations in MEK1 that disrupt Cu binding reduced BRAFV600E-driven signaling and tumorigenesis. Conversely, a MEK1-MEK5 chimera that phosphorylates ERK1/2 independent of Cu or an active ERK2 restored tumor growth to cells lacking Ctr1. Importantly, Cu chelators used in the treatment of Wilson disease7 reduced tumor growth of both BRAFV600E-transformed cells and cells resistant to BRAF inhibition. Taken together, these results suggest that Cu-chelation therapy could be repurposed to treat BRAFV600E mutation-positive cancers. PMID:24717435

  10. The LMO2 oncogene regulates DNA replication in hematopoietic cells

    PubMed Central

    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

    2016-01-01

    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. PMID:26764384

  11. Genomic and oncogenic preference of HBV integration in hepatocellular carcinoma

    PubMed Central

    Zhao, Ling-Hao; Liu, Xiao; Yan, He-Xin; Li, Wei-Yang; Zeng, Xi; Yang, Yuan; Zhao, Jie; Liu, Shi-Ping; Zhuang, Xue-Han; Lin, Chuan; Qin, Chen-Jie; Zhao, Yi; Pan, Ze-Ya; Huang, Gang; Liu, Hui; Zhang, Jin; Wang, Ruo-Yu; Yang, Yun; Wen, Wen; Lv, Gui-Shuai; Zhang, Hui-Lu; Wu, Han; Huang, Shuai; Wang, Ming-Da; Tang, Liang; Cao, Hong-Zhi; Wang, Ling; Lee, T.P.; Jiang, Hui; Tan, Ye-Xiong; Yuan, Sheng-Xian; Hou, Guo-Jun; Tao, Qi-Fei; Xu, Qin-Guo; Zhang, Xiu-Qing; Wu, Meng-Chao; Xu, Xun; Wang, Jun; Yang, Huan-Ming; Zhou, Wei-Ping; Wang, Hong-Yang

    2016-01-01

    Hepatitis B virus (HBV) can integrate into the human genome, contributing to genomic instability and hepatocarcinogenesis. Here by conducting high-throughput viral integration detection and RNA sequencing, we identify 4,225 HBV integration events in tumour and adjacent non-tumour samples from 426 patients with HCC. We show that HBV is prone to integrate into rare fragile sites and functional genomic regions including CpG islands. We observe a distinct pattern in the preferential sites of HBV integration between tumour and non-tumour tissues. HBV insertional sites are significantly enriched in the proximity of telomeres in tumours. Recurrent HBV target genes are identified with few that overlap. The overall HBV integration frequency is much higher in tumour genomes of males than in females, with a significant enrichment of integration into chromosome 17. Furthermore, a cirrhosis-dependent HBV integration pattern is observed, affecting distinct targeted genes. Our data suggest that HBV integration has a high potential to drive oncogenic transformation. PMID:27703150

  12. Relaxin Enhances the Oncogenic Potential of Human Thyroid Carcinoma Cells

    PubMed Central

    Hombach-Klonisch, Sabine; Bialek, Joanna; Trojanowicz, Bogusz; Weber, Ekkehard; Holzhausen, Hans-Jürgen; Silvertown, Josh D.; Summerlee, Alastair J.; Dralle, Henning; Hoang-Vu, Cuong; Klonisch, Thomas

    2006-01-01

    The role of members of the insulin-like superfamily in human thyroid carcinoma is primarily unknown. Here we demonstrate the presence of RLN2 relaxin and relaxin receptor LGR7 in human papillary, follicular, and undifferentiated anaplastic thyroid carcinoma suggesting a specific involvement of relaxin-LGR7 signaling in thyroid carcinoma. Stable transfectants of the LGR7-positive human follicular thyroid carcinoma cell lines FTC-133 and FTC-238 that secrete bioactive proRLN2 revealed this hormone to act as a multifunctional endocrine factor in thyroid carcinoma cells. Although RLN2 did not act as a mitogen, it acted as an autocrine/paracrine factor and significantly increased anchorage-independent growth and thyroid carcinoma cell motility and invasiveness through elastin matrices. Suppression of LGR7 expression by LGR7-siRNA abolished the RLN2-mediated accelerated tumor cell motility. The increased elastinolytic activity correlated with enhanced production and secretion of the lysosomal proteinases cathepsin-D (cath-D) and cath-L forms hereby identified as new RLN2 target molecules in human neoplastic thyrocytes. We found the intracellular distribution of procath-L specifically altered in RLN2 transfectants, providing first evidence for selective actions of relaxin on the powerful elastinolytic cath-L production, storage, and secretion in thyroid carcinoma cells. Thus, relaxin enhances the oncogenic potential and acts as novel endocrine modulator of invasiveness in human thyroid carcinoma cells. PMID:16877360

  13. Relaxin enhances the oncogenic potential of human thyroid carcinoma cells.

    PubMed

    Hombach-Klonisch, Sabine; Bialek, Joanna; Trojanowicz, Bogusz; Weber, Ekkehard; Holzhausen, Hans-Jürgen; Silvertown, Josh D; Summerlee, Alastair J; Dralle, Henning; Hoang-Vu, Cuong; Klonisch, Thomas

    2006-08-01

    The role of members of the insulin-like superfamily in human thyroid carcinoma is primarily unknown. Here we demonstrate the presence of RLN2 relaxin and relaxin receptor LGR7 in human papillary, follicular, and undifferentiated anaplastic thyroid carcinoma suggesting a specific involvement of relaxin-LGR7 signaling in thyroid carcinoma. Stable transfectants of the LGR7-positive human follicular thyroid carcinoma cell lines FTC-133 and FTC-238 that secrete bioactive proRLN2 revealed this hormone to act as a multifunctional endocrine factor in thyroid carcinoma cells. Although RLN2 did not act as a mitogen, it acted as an autocrine/paracrine factor and significantly increased anchorage-independent growth and thyroid carcinoma cell motility and invasiveness through elastin matrices. Suppression of LGR7 expression by LGR7-siRNA abolished the RLN2-mediated accelerated tumor cell motility. The increased elastinolytic activity correlated with enhanced production and secretion of the lysosomal proteinases cathepsin-D (cath-D) and cath-L forms hereby identified as new RLN2 target molecules in human neoplastic thyrocytes. We found the intracellular distribution of procath-L specifically altered in RLN2 transfectants, providing first evidence for selective actions of relaxin on the powerful elastinolytic cath-L production, storage, and secretion in thyroid carcinoma cells. Thus, relaxin enhances the oncogenic potential and acts as novel endocrine modulator of invasiveness in human thyroid carcinoma cells.

  14. Oncogenic Role of Merlin/NF2 in Glioblastoma

    PubMed Central

    Guerrero, Paola A.; Yin, Wei; Camacho, Laura; Marchetti, Dario

    2014-01-01

    Glioblastoma is the most common and aggressive primary brain tumor in adults, with a poor prognosis because of its resistance to radiotherapy and chemotherapy. Merlin/NF2 (neurofibromatosis type 2) is a tumor suppressor found to be mutated in most nervous system tumors; however, it is not mutated in glioblastomas. Merlin associates with several transmembrane receptors and intracellular proteins serving as an anchoring molecule. Additionally, it acts as a key component of cell motility. By selecting subpopulations of U251 glioblastoma cells, we observed that high expression of phosphorylated Merlin at serine 518 (S518-Merlin), Notch1 and epidermal growth factor receptor (EGFR) correlated with increased cell proliferation and tumorigenesis. These cells were defective in cell-contact inhibition with changes in Merlin phosphorylation directly affecting Notch1, EGFR expression as well as downstream targets Hes1 and Ccnd. Of note, we identified a function for S518-Merlin which is distinct from what has been reported when the expression of Merlin is diminished in relation to EGFR and Notch expression, providing first-time evidence that demonstrates that the phosphorylation of Merlin at S518 in glioblastoma promotes oncogenic properties that are not only the result of inactivation of the tumor suppressor role of Merlin, but also, an independent process implicating a Merlin-driven regulation of Notch1 and EGFR. PMID:25043298

  15. A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors

    PubMed Central

    Gayvert, Kaitlyn; Dardenne, Etienne; Cheung, Cynthia; Boland, Mary Regina; Lorberbaum, Tal; Wanjala, Jackline; Chen, Yu; Rubin, Mark; Tatonetti, Nicholas P.; Rickman, David; Elemento, Olivier

    2016-01-01

    Summary Mutations in transcription factors (TFs) genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a Computational drug-Repositioning Approach For Targeting Transcription factor activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb TF activity. Application to ENCODE ChIP-seq datasets revealed known drug-TF interactions and a global drug-protein network analysis further supported these predictions. Application of CRAFTT to ERG, a pro-invasive, frequently over-expressed oncogenic TF predicted that dexamethasone would inhibit ERG activity. Indeed, dexamethasone significantly decreased cell invasion and migration in an ERG-dependent manner. Furthermore, analysis of Electronic Medical Record data indicates a protective role for dexamethasone against prostate cancer. Altogether, our method provides a broadly applicable strategy to identify drugs that specifically modulate TF activity. PMID:27264179

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

    PubMed Central

    Xu, Chao; Zhao, Hong; Chen, Haitao; Yao, Qinghua

    2015-01-01

    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. PMID:26356032

  17. Papillomavirus sequences integrate near cellular oncogenes in some cervical carcinomas

    SciTech Connect

    Duerst, M.; Croce, C.M.; Gissmann, L.; Schwarz, E.; Huebner, K.

    1987-02-01

    The chromosomal locations of cellular sequences flanking integrated papillomavirus DNA in four cervical cell lines and a primary cervical carcinoma have been determined. The two human papillomavirus (HPV) 16 flanking sequences derived from the tumor were localized to chromosomes regions 20pter..-->..20q13 and 3p25..-->..3qter, regions that also contain the protooncogenes c-src-1 and c-raf-1, respectively. The HPV 16 integration site in the SiHa cervical carcinoma-derived cell line is in chromosome region 13q14..-->..13q32. The HPV 18 integration site in SW756 cervical carcinoma cells is in chromosome 12 but is not closely linked to the Ki-ras2 gene. Finally, in two cervical carcinoma cell lines, HeLa and C4-I, HPV 18 DNA is integrated in chromosome 8, 5' of the c-myc gene. The HeLaHPV 18 integration site is within 40 kilobases 5' of the c-myc gene, inside the HL60 amplification unit surrounding and including the c-myc gene. Additionally, steady-state levels of c-myc mRNA are elevated in HeLa and C4-I cells relative to other cervical carcinoma cell lines. Thus, in at least some genital tumors, cis-activation of cellular oncogenes by HPV may be involved in malignant transformation of cervical cells.

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

    SciTech Connect

    Sichero, Laura; Simao Sobrinho, Joao; Lina Villa, Luisa

    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.

  19. Fusion oncogenes in salivary gland tumors: molecular and clinical consequences.

    PubMed

    Stenman, Göran

    2013-07-01

    Salivary gland tumors constitute a heterogeneous group of uncommon diseases that pose significant diagnostic and therapeutic challenges. However, the recent discovery of a translocation-generated gene fusion network in salivary gland carcinomas as well in benign salivary gland tumors opens up new avenues for improved diagnosis, prognostication, and development of specific targeted therapies. The gene fusions encode novel fusion oncoproteins or ectopically expressed normal or truncated oncoproteins. The major targets of the translocations are transcriptional coactivators, tyrosine kinase receptors, and transcription factors involved in growth factor signaling and cell cycle regulation. Notably, several of these targets or pathways activated by these targets are druggable. Examples of clinically significant gene fusions in salivary gland cancers are the MYB-NFIB fusion specific for adenoid cystic carcinoma, the CRTC1-MAML2 fusion typical of low/intermediate-grade mucoepidermoid carcinoma, and the recently identified ETV6-NTRK3 fusion in mammary analogue secretory carcinoma. Similarly, gene fusions involving the PLAG1 and HMGA2 oncogenes are specific for benign pleomorphic adenomas. Continued studies of the molecular consequences of these fusion oncoproteins and their down-stream targets will ultimately lead to the identification of novel driver genes in salivary gland neoplasms and will also form the basis for the development of new therapeutic strategies for salivary gland cancers and, perhaps, other neoplasms.

  20. MDMX exerts its oncogenic activity via suppression of retinoblastoma protein.

    PubMed

    Zhang, H; Hu, L; Qiu, W; Deng, T; Zhang, Y; Bergholz, J; Xiao, Z-X

    2015-10-29

    Inactivation of the retinoblastoma protein (RB) has a major role in the development of human malignancies. We have previously shown that MDM2, an ubiquitin E3 ligase and major negative regulator of p53, binds to and promotes proteasome-mediated degradation of RB. MDMX, a homolog of MDM2, also binds to and inhibits p53 transactivation activity, yet it does not possess intrinsic ubiquitin ligase activity. Here, we show that MDMX binds to and promotes RB degradation in an MDM2-dependent manner. Specifically, the MDMX C-terminal ring domain binds to the RB C-pocket and enhances MDM2-RB interaction. Silencing MDMX induces RB accumulation, cell cycle arrest and senescence-like phenotypes, which are reverted by simultaneous RB knockdown. Furthermore, MDMX ablation leads to significant retardation of xenograft tumor growth, concomitant with RB accumulation. These results demonstrate that MDMX exerts oncogenic activity via suppression of RB, and suggest that both MDM2 and MDMX could be chemotherapeutic targets. PMID:25703327

  1. ARF and ATM/ATR cooperate in p53-mediated apoptosis upon oncogenic stress

    SciTech Connect

    Pauklin, Siim . E-mail: spauklin@ut.ee; Kristjuhan, Arnold; Maimets, Toivo; Jaks, Viljar

    2005-08-26

    Induction of apoptosis is pivotal for eliminating cells with damaged DNA or deregulated proliferation. We show that tumor suppressor ARF and ATM/ATR kinase pathways cooperate in the induction of apoptosis in response to elevated expression of c-myc, {beta}-catenin or human papilloma virus E7 oncogenes. Overexpression of oncogenes leads to the formation of phosphorylated H2AX foci, induction of Rad51 protein levels and ATM/ATR-dependent phosphorylation of p53. Inhibition of ATM/ATR kinases abolishes both induction of Rad51 and phosphorylation of p53, and remarkably reduces the level of apoptosis induced by co-expression of oncogenes and ARF. However, the induction of apoptosis is downregulated in p53-/- cells and does not depend on activities of ATM/ATR kinases, indicating that efficient induction of apoptosis by oncogene activation depends on coordinated action of ARF and ATM/ATR pathways in the regulation of p53.

  2. Oncogenic and tumor-promoting Spermatophytes and Pteridophytes and their active principles.

    PubMed

    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.

  3. Duplication of the MYB oncogene in T cell acute lymphoblastic leukemia.

    PubMed

    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.

  4. P120-GAP associated with syndecan-2 to function as an active switch signal for Src upon transformation with oncogenic ras

    SciTech Connect

    Huang, J.-W.; Chen, C.-L.; Chuang, N.-N. . E-mail: zonnc@sinica.edu.tw

    2005-04-15

    BALB/3T3 cells transfected with plasmids pcDNA3.1-[S-ras(Q{sub 61}K)] of shrimp Penaeus japonicus were applied to reveal a complex of p120-GAP/syndecan-2 being highly expressed upon transformation. Of interest, most of the p120-GAP/syndecan-2 complex was localized at caveolae, a membrane microdomain enriched with caveolin-1. To confirm the molecular interaction between syndecan-2 and p120-GAP, we further purified p120-GAP protein from mouse brains by using an affinity column of HiTrap-RACK1 and expressed mouse RACK1-encoded fusion protein and mouse syndecan-2-encoded fusion protein in bacteria. We report molecular affinities exist between p120-GAP and RACK1, syndecan-2 and RACK1 as well as p120-GAP and syndecan-2. The selective affinity between p120-GAP and syndecan-2 was found to be sufficient to detach RACK1. The p120-GAP/syndecan-2 complex was demonstrated to keep Src tyrosine kinase in an activated form. On the other hand, the syndecan-2/RACK1 complex was found to have Src in an inactivated form. These data indicate that the p120-GAP/syndecan-2 complex at caveolae could provide a docking site for Src to transmit tyrosine signaling, implying that syndecan-2/p120-GAP functions as a tumor promoter upon transformation with oncogenic ras of shrimp P. japonicus.

  5. αE-catenin inhibits a Src-YAP1 oncogenic module that couples tyrosine kinases and the effector of Hippo signaling pathway.

    PubMed

    Li, Peng; Silvis, Mark R; Honaker, Yuchi; Lien, Wen-Hui; Arron, Sarah T; Vasioukhin, Valeri

    2016-04-01

    Cell-cell adhesion protein αE-catenin inhibits skin squamous cell carcinoma (SCC) development; however, the mechanisms responsible for this function are not completely understood. We report here that αE-catenin inhibits β4 integrin-mediated activation of SRC tyrosine kinase.SRCis the first discovered oncogene, but the protein substrate critical for SRC-mediated transformation has not been identified. We found that YAP1, the pivotal effector of the Hippo signaling pathway, is a direct SRC phosphorylation target, and YAP1 phosphorylation at three sites in its transcription activation domain is necessary for SRC-YAP1-mediated transformation. We uncovered a marked increase in this YAP1 phosphorylation in human and mouse SCC tumors with low/negative expression of αE-catenin. We demonstrate that the tumor suppressor function of αE-catenin involves negative regulation of the β4 integrin-SRC signaling pathway and that SRC-mediated phosphorylation and activation of YAP1 are an alternative to the canonical Hippo signaling pathway that directly connect oncogenic tyrosine kinase signaling with YAP1. PMID:27013234

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

    PubMed

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

    2010-02-01

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

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

    SciTech Connect

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

    1987-03-01

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

  8. Direct Targeting of β-Catenin by a Small Molecule Stimulates Proteasomal Degradation and Suppresses Oncogenic Wnt/β-Catenin Signaling.

    PubMed

    Hwang, So-Young; Deng, Xianming; Byun, Sanguine; Lee, Chan; Lee, Seung-Joo; Suh, Hyunsuk; Zhang, Jianming; Kang, Qiaofeng; Zhang, Ting; Westover, Kenneth D; Mandinova, Anna; Lee, Sam W

    2016-06-28

    The Wnt/β-catenin signaling pathway plays a major role in tissue homeostasis, and its dysregulation can lead to various human diseases. Aberrant activation of β-catenin is oncogenic and is a critical driver in the development and progression of human cancers. Despite the significant potential of targeting the oncogenic β-catenin pathway for cancer therapy, the development of specific inhibitors remains insufficient. Using a T cell factor (TCF)-dependent luciferase-reporter system, we screened for small-molecule compounds that act against Wnt/β-catenin signaling and identified MSAB (methyl 3-{[(4-methylphenyl)sulfonyl]amino}benzoate) as a selective inhibitor of Wnt/β-catenin signaling. MSAB shows potent anti-tumor effects selectively on Wnt-dependent cancer cells in vitro and in mouse cancer models. MSAB binds to β-catenin, promoting its degradation, and specifically downregulates Wnt/β-catenin target genes. Our findings might represent an effective therapeutic strategy for cancers addicted to the Wnt/β-catenin signaling pathway. PMID:27320923

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

    PubMed

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

    2014-08-01

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

  10. Ras-mediated cell cycle arrest is altered by nuclear oncogenes to induce Schwann cell transformation.

    PubMed Central

    Ridley, A J; Paterson, H F; Noble, M; Land, H

    1988-01-01

    The cellular responses to ras and nuclear oncogenes were investigated in purified populations of rat Schwann cells. v-Ha-ras and SV40 large T cooperate to transform Schwann cells, inducing growth in soft agar and allowing proliferation in the absence of added mitogens. Expression of large T alone reduces their growth factor requirements but is insufficient to induce full transformation. In contrast, expression of v-Ha-ras leads to proliferation arrest in Schwann cells expressing a temperature-sensitive mutant of large T at the restrictive temperature. Cells arrest in either the G1 or G2/M phases of the cell cycle, and can re-enter cell division at the permissive temperature even after prolonged periods at the restrictive conditions. Oncogenic ras proteins also inhibit DNA synthesis when microinjected into Schwann cells. Adenovirus E1a and c-myc oncogenes behave similarly to SV40 large T. They cooperate with Ha-ras oncogenes to transform Schwann cells, and prevent ras-induced growth arrest. Thus nuclear oncogenes fundamentally alter the response of Schwann cells to a ras oncogene from cell cycle arrest to transformation. Images PMID:3049071

  11. Translation Start Sequences Affect the Efficiency of Silencing of Agrobacterium tumefaciens T-DNA Oncogenes1

    PubMed Central

    Lee, Hyewon; Humann, Jodi L.; Pitrak, Jennifer S.; Cuperus, Josh T.; Parks, T. Dawn; Whistler, Cheryl A.; Mok, Machteld C.; Ream, L. Walt

    2003-01-01

    Agrobacterium tumefaciens oncogenes cause transformed plant cells to overproduce auxin and cytokinin. Two oncogenes encode enzymes that convert tryptophan to indole-3-acetic acid (auxin): iaaM (tryptophan mono-oxygenase) and iaaH (indole-3-acetamide hydrolase). A third oncogene (ipt) encodes AMP isopentenyl transferase, which produces cytokinin (isopentenyl-AMP). Inactivation of ipt and iaaM (or iaaH) abolishes tumorigenesis. Because adequate means do not exist to control crown gall, we created resistant plants by introducing transgenes designed to elicit posttranscriptional gene silencing (PTGS) of iaaM and ipt. Transgenes that elicit silencing trigger sequence-specific destruction of the inducing RNA and messenger RNAs with related sequences. Although PTGS has proven effective against a variety of target genes, we found that a much higher percentage of transgenic lines silenced iaaM than ipt, suggesting that transgene sequences influenced the effectiveness of PTGS. Sequences required for oncogene silencing included a translation start site. A transgene encoding a translatable sense-strand RNA from the 5′ end of iaaM silenced the iaaM oncogene, but deletion of the translation start site abolished the ability of the transgene to silence iaaM. Silencing A. tumefaciens T-DNA oncogenes is a new and effective method to produce plants resistant to crown gall disease. PMID:12972655

  12. Induction of p38δ Expression Plays an Essential Role in Oncogenic ras-Induced Senescence

    PubMed Central

    Kwong, Jinny; Chen, Michelle; Lv, Dan; Luo, Na; Su, Weijun; Xiang, Rong

    2013-01-01

    Oncogene-induced senescence is a stable proliferative arrest that serves as a tumor-suppressing defense mechanism. p38 mitogen-activated protein kinase (MAPK) has been implicated in oncogene-induced senescence and tumor suppression. However, the specific role of each of the four p38 isoforms in oncogene-induced senescence is not fully understood. Here, we demonstrate that p38δ mediates oncogene-induced senescence through a p53- and p16INK4A-independent mechanism. Instead, evidence suggests a link between p38δ and the DNA damage pathways. Moreover, we have discovered a novel mechanism that enhances the expression of p38δ during senescence. In this mechanism, oncogenic ras induces the Raf-1–MEK–extracellular signal-regulated kinase (ERK) pathway, which, in turn, activates the AP-1 and Ets transcription factors that are bound to the p38δ promoter, leading to increased transcription of p38δ. These findings indicate that induction of the prosenescent function of p38δ by oncogenic ras is achieved through 2 mechanisms, transcriptional activation by the Raf-1–MEK–ERK–AP-1/Ets pathway, which increases the cellular concentration of the p38δ protein, and posttranslational modification by MKK3/6, which stimulates the enzymatic activity of p38δ. In addition, these studies identify the AP-1 and Ets transcription factors as novel signaling components in the senescence-inducing pathway. PMID:23878395

  13. Mutational landscape of EGFR-, MYC-, and Kras-driven genetically engineered mouse models of lung adenocarcinoma

    PubMed Central

    McFadden, David G.; Politi, Katerina; Bhutkar, Arjun; Chen, Frances K.; Song, Xiaoling; Pirun, Mono; Santiago, Philip M.; Kim-Kiselak, Caroline; Platt, James T.; Lee, Emily; Hodges, Emily; Rosebrock, Adam P.; Bronson, Roderick T.; Socci, Nicholas D.; Hannon, Gregory J.; Jacks, Tyler; Varmus, Harold

    2016-01-01

    Genetically engineered mouse models (GEMMs) of cancer are increasingly being used to assess putative driver mutations identified by large-scale sequencing of human cancer genomes. To accurately interpret experiments that introduce additional mutations, an understanding of the somatic genetic profile and evolution of GEMM tumors is necessary. Here, we performed whole-exome sequencing of tumors from three GEMMs of lung adenocarcinoma driven by mutant epidermal growth factor receptor (EGFR), mutant Kirsten rat sarcoma viral oncogene homolog (Kras), or overexpression of MYC proto-oncogene. Tumors from EGFR- and Kras-driven models exhibited, respectively, 0.02 and 0.07 nonsynonymous mutations per megabase, a dramatically lower average mutational frequency than observed in human lung adenocarcinomas. Tumors from models driven by strong cancer drivers (mutant EGFR and Kras) harbored few mutations in known cancer genes, whereas tumors driven by MYC, a weaker initiating oncogene in the murine lung, acquired recurrent clonal oncogenic Kras mutations. In addition, although EGFR- and Kras-driven models both exhibited recurrent whole-chromosome DNA copy number alterations, the specific chromosomes altered by gain or loss were different in each model. These data demonstrate that GEMM tumors exhibit relatively simple somatic genotypes compared with human cancers of a similar type, making these autochthonous model systems useful for additive engineering approaches to assess the potential of novel mutations on tumorigenesis, cancer progression, and drug sensitivity. PMID:27702896

  14. Dominant negative and loss of function mutations of the c-kit (mast/stem cell growth factor receptor) proto-oncogene in human piebaldism

    SciTech Connect

    Spritz, R.A.; Giebel, L.B.; Holmes, S.A. )

    1992-02-01

    Piebaldism is an autosomal dominant disorder of melanocyte development and is characterized by congenital white parches of skin and hair from which melanocytes are completely absent. A similar disorder of the mouse, 'dominant white spotting' (W), results from mutations of the c-kit proto-oncogene, which encodes the cellular tyrosine kinases receptor for the mast/stem cell growth factor. The authors have identified c-kit gene mutations in three patients with piebaldism. A missense substitution (Phe[r arrow]Leu) at codon 584, within the tyrosine kinases domain, is associated with a severe piebald phenotype, whereas two different frameshifts, within codons 561 and 642, are both associated with a variable and relatively mild piebald phenotype. This is consistent with a possible 'dominant negative' effect of missense c-kit polypeptides on the function of the dimeric receptor.

  15. A conditional piggyBac transposition system for genetic screening in mice identifies oncogenic networks in pancreatic cancer.

    PubMed

    Rad, Roland; Rad, Lena; Wang, Wei; Strong, Alexander; Ponstingl, Hannes; Bronner, Iraad F; Mayho, Matthew; Steiger, Katja; Weber, Julia; Hieber, Maren; Veltkamp, Christian; Eser, Stefan; Geumann, Ulf; Öllinger, Rupert; Zukowska, Magdalena; Barenboim, Maxim; Maresch, Roman; Cadiñanos, Juan; Friedrich, Mathias; Varela, Ignacio; Constantino-Casas, Fernando; Sarver, Aaron; Ten Hoeve, Jelle; Prosser, Haydn; Seidler, Barbara; Bauer, Judith; Heikenwälder, Mathias; Metzakopian, Emmanouil; Krug, Anne; Ehmer, Ursula; Schneider, Günter; Knösel, Thomas; Rümmele, Petra; Aust, Daniela; Grützmann, Robert; Pilarsky, Christian; Ning, Zemin; Wessels, Lodewyk; Schmid, Roland M; Quail, Michael A; Vassiliou, George; Esposito, Irene; Liu, Pentao; Saur, Dieter; Bradley, Allan

    2015-01-01

    Here we describe a conditional piggyBac transposition system in mice and report the discovery of large sets of new cancer genes through a pancreatic insertional mutagenesis screen. We identify Foxp1 as an oncogenic transcription factor that drives pancreatic cancer invasion and spread in a mouse model and correlates with lymph node metastasis in human patients with pancreatic cancer. The propensity of piggyBac for open chromatin also enabled genome-wide screening for cancer-relevant noncoding DNA, which pinpointed a Cdkn2a cis-regulatory region. Histologically, we observed different tumor subentities and discovered associated genetic events, including Fign insertions in hepatoid pancreatic cancer. Our studies demonstrate the power of genetic screening to discover cancer drivers that are difficult to identify by other approaches to cancer genome analysis, such as downstream targets of commonly mutated human cancer genes. These piggyBac resources are universally applicable in any tissue context and provide unique experimental access to the genetic complexity of cancer.

  16. Spi-1/PU.1 oncogene accelerates DNA replication fork elongation and promotes genetic instability in the absence of DNA breakage.

    PubMed

    Rimmelé, Pauline; Komatsu, Jun; Hupé, Philippe; Roulin, Christophe; Barillot, Emmanuel; Dutreix, Marie; Conseiller, Emmanuel; Bensimon, Aaron; Moreau-Gachelin, Françoise; Guillouf, Christel

    2010-09-01

    The multistage process of cancer formation is driven by the progressive acquisition of somatic mutations. Replication stress creates genomic instability in mammals. Using a well-defined multistep leukemia model driven by Spi-1/PU.1 overexpression in the mouse and Spi-1/PU.1-overexpressing human leukemic cells, we investigated the relationship between DNA replication and cancer progression. Here, using DNA molecular combing and flow cytometry methods, we show that Spi-1 increases the speed of replication by acting specifically on elongation rather than enhancing origin firing. This shortens the S-phase duration. Combining data from Spi-1 knockdown in murine cells with Spi-1 overexpression in human cells, we provide evidence that inappropriate Spi-1 expression is directly responsible for the replication alteration observed. Importantly, the acceleration of replication progression coincides with an increase in the frequency of genomic mutations without inducing DNA breakage. Thus, we propose that the hitherto unsuspected role for spi-1 oncogene in promoting replication elongation and genomic mutation promotes blastic progression during leukemic development.

  17. Specific oncogenic activity of the Src-family tyrosine kinase c-Yes in colon carcinoma cells.

    PubMed

    Sancier, Florence; Dumont, Aurélie; Sirvent, Audrey; Paquay de Plater, Ludmilla; Edmonds, Thomas; David, Géraldine; Jan, Michel; de Montrion, Catherine; Cogé, Francis; Léonce, Stéphane; Burbridge, Michael; Bruno, Alain; Boutin, Jean A; Lockhart, Brian; Roche, Serge; Cruzalegui, Francisco

    2011-02-24

    c-Yes, a member of the Src tyrosine kinase family, is found highly activated in colon carcinoma but its importance relative to c-Src has remained unclear. Here we show that, in HT29 colon carcinoma cells, silencing of c-Yes, but not of c-Src, selectively leads to an increase of cell clustering associated with a localisation of β-catenin at cell membranes and a reduction of expression of β-catenin target genes. c-Yes silencing induced an increase in apoptosis, inhibition of growth in soft-agar and in mouse xenografts, inhibition of cell migration and loss of the capacity to generate liver metastases in mice. Re-introduction of c-Yes, but not c -Src, restores transforming properties of c-Yes depleted cells. Moreover, we found that c-Yes kinase activity is required for its role in β-catenin localisation and growth in soft agar, whereas kinase activity is dispensable for its role in cell migration. We conclude that c-Yes regulates specific oncogenic signalling pathways important for colon cancer progression that is not shared with c-Src.

  18. Oncogenic KRAS and BRAF Drive Metabolic Reprogramming in Colorectal Cancer.

    PubMed

    Hutton, Josiah E; Wang, Xiaojing; Zimmerman, Lisa J; Slebos, Robbert J C; Trenary, Irina A; Young, Jamey D; Li, Ming; Liebler, Daniel C

    2016-09-01

    Metabolic reprogramming, in which altered utilization of glucose and glutamine supports rapid growth, is a hallmark of most cancers. Mutations in the oncogenes KRAS and BRAF drive metabolic reprogramming through enhanced glucose uptake, but the broader impact of these mutations on pathways of carbon metabolism is unknown. Global shotgun proteomic analysis of isogenic DLD-1 and RKO colon cancer cell lines expressing mutant and wild type KRAS or BRAF, respectively, failed to identify significant differences (at least 2-fold) in metabolic protein abundance. However, a multiplexed parallel reaction monitoring (PRM) strategy targeting 73 metabolic proteins identified significant protein abundance increases of 1.25-twofold in glycolysis, the nonoxidative pentose phosphate pathway, glutamine metabolism, and the phosphoserine biosynthetic pathway in cells with KRAS G13D mutations or BRAF V600E mutations. These alterations corresponded to mutant KRAS and BRAF-dependent increases in glucose uptake and lactate production. Metabolic reprogramming and glucose conversion to lactate in RKO cells were proportional to levels of BRAF V600E protein. In DLD-1 cells, these effects were independent of the ratio of KRAS G13D to KRAS wild type protein. A study of 8 KRAS wild type and 8 KRAS mutant human colon tumors confirmed the association of increased expression of glycolytic and glutamine metabolic proteins with KRAS mutant status. Metabolic reprogramming is driven largely by modest (<2-fold) alterations in protein expression, which are not readily detected by the global profiling methods most commonly employed in proteomic studies. The results indicate the superiority of more precise, multiplexed, pathway-targeted analyses to study functional proteome systems. Data are available through MassIVE Accession MSV000079486 at ftp://MSV000079486@massive.ucsd.edu. PMID:27340238

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

    PubMed

    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.

  20. Cul4A is an oncogene in malignant pleural mesothelioma.

    PubMed

    Hung, Ming-Szu; Mao, Jian-Hua; Xu, Zhidong; Yang, Cheng-Ta; Yu, Jau-Song; Harvard, Chansonette; Lin, Yu-Ching; Bravo, Dawn Therese; Jablons, David M; You, Liang

    2011-02-01

    Cullin 4A (Cul4A) is important in cell survival, development, growth and the cell cycle, but its role in mesothelioma has not been studied. For the first time, we identified amplification of the Cul4A gene in four of five mesothelioma cell lines. Consistent with increased Cul4A gene copy number, we found that Cul4A protein was overexpressed in mesothelioma cells as well. Cul4A protein was also overexpressed in 64% of primary malignant pleural mesothelioma (MPM) tumours. Furthermore, knockdown of Cul4A with shRNA in mesothelioma cells resulted in up-regulation of p21 and p27 tumour suppressor proteins in a p53-independent manner in H290, H28 and MS-1 mesothelioma cell lines. Knockdown of Cul4A also resulted in G0/G1 cell cycle arrest and decreased colony formation in H290, H28 and MS-1 mesothelioma cell lines. Moreover, G0/G1 cell cycle arrest was partially reversed by siRNA down-regulation of p21 and/or p27 in Cul4A knockdown H290 cell line. In the contrary, overexpression of Cul4A resulted in down-regulation of p21 and p27 proteins and increased colony formation in H28 mesothelioma cell line. Both p21 and p27 showed faster degradation rates in Cul4A overexpressed H28 cell line and slower degradation rates in Cul4A knockdown H28 cell line. Our study indicates that Cul4A amplification and overexpression play an oncogenic role in the pathogenesis of mesothelioma. Thus, Cul4A may be a potential therapeutic target for MPM.

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

    PubMed

    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.

  2. ER functions of oncogenes and tumor suppressors: Modulators of intracellular Ca(2+) signaling.

    PubMed

    Bittremieux, Mart; Parys, Jan B; Pinton, Paolo; Bultynck, Geert

    2016-06-01

    Intracellular Ca(2+) signals that arise from the endoplasmic reticulum (ER), the major intracellular Ca(2+)-storage organelle, impact several mitochondrial functions and dictate cell survival and cell death processes. Furthermore, alterations in Ca(2+) signaling in cancer cells promote survival and establish a high tolerance towards cell stress and damage, so that the on-going oncogenic stress does not result in the activation of cell death. Over the last years, the mechanisms underlying these oncogenic alterations in Ca(2+) signaling have started to emerge. An important aspect of this is the identification of several major oncogenes, including Bcl-2, Bcl-XL, Mcl-1, PKB/Akt, and Ras, and tumor suppressors, such as p53, PTEN, PML, BRCA1, and Beclin 1, as direct and critical regulators of Ca(2+)-transport systems located at the ER membranes, including IP3 receptors and SERCA Ca(2+) pumps. In this way, these proteins execute part of their function by controlling the ER-mitochondrial Ca(2+) fluxes, favoring either survival (oncogenes) or cell death (tumor suppressors). Oncogenic mutations, gene deletions or amplifications alter the expression and/or function of these proteins, thereby changing the delicate balance between oncogenes and tumor suppressors, impacting oncogenesis and favoring malignant cell function and behavior. In this review, we provided an integrated overview of the impact of the major oncogenes and tumor suppressors, often altered in cancer cells, on Ca(2+) signaling from the ER Ca(2+) stores. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen.

  3. p38alpha and p38gamma mediate oncogenic ras-induced senescence through differential mechanisms.

    PubMed

    Kwong, Jinny; Hong, Lixin; Liao, Rong; Deng, Qingdong; Han, Jiahuai; Sun, Peiqing

    2009-04-24

    Oncogene-induced senescence is a tumor-suppressive defense mechanism triggered upon activation of certain oncogenes in normal cells. Recently, the senescence response to oncogene activation has been shown to act as a bona fide barrier to cancer development in vivo. Multiple previous studies have implicated the importance of the p38 MAPK pathway in oncogene-induced senescence. However, the contribution of each of the four p38 isoforms (encoded by different genes) to senescence induction is unclear. In the current study, we demonstrated that p38alpha and p38gamma, but not p38beta, play an essential role in oncogenic ras-induced senescence. Both p38alpha and p38gamma are expressed in primary human fibroblasts and are activated upon transduction of oncogenic ras. Small hairpin RNA-mediated silencing of p38alpha or p38gamma expression abrogated ras-induced senescence, whereas constitutive activation of p38alpha and p38gamma caused premature senescence. Furthermore, upon activation by oncogenic ras, p38gamma stimulated the transcriptional activity of p53 by phosphorylating p53 at Ser(33), suggesting that the ability of p38gamma to mediate senescence is at least partly achieved through p53. However, p38alpha contributed to ras-inducted senescence via a p53-indepdendent mechanism in cells by mediating ras-induced expression of p16(INK4A), another key senescence effector. These findings have identified p38alpha and p38gamma as essential components of the signaling pathway that regulates the tumor-suppressing senescence response, providing insights into the molecular mechanisms underlying the differential involvement of the p38 isoforms in senescence induction.

  4. Diversity of mutations in the RET proto-oncogene and its oncogenic mechanism in medullary thyroid cancer.

    PubMed

    Hedayati, Mehdi; Zarif Yeganeh, Marjan; Sheikholeslami, Sara; Afsari, Farinaz

    2016-08-01

    Thyroid cancer is the most common endocrine malignancy and accounts for nearly 1% of all of human cancer. Thyroid cancer has four main histological types: papillary, follicular, medullary, and anaplastic. Papillary, follicular, and anaplastic thyroid carcinomas are derived from follicular thyroid cells, whereas medullary thyroid carcinoma (MTC) originates from the neural crest parafollicular cells or C-cells of the thyroid gland. MTC represents a neuroendocrine tumor and differs considerably from differentiated thyroid carcinoma. MTC is one of the aggressive types of thyroid cancer, which represents 3-10% of all thyroid cancers. It occurs in hereditary (25%) and sporadic (75%) forms. The hereditary form of MTC has an autosomal dominant mode of inheritance. According to the present classification, hereditary MTC is classified as a multiple endocrine neoplasi type 2 A & B (MEN2A & MEN2B) and familial MTC (FMTC). The RET proto-oncogene is located on chromosome 10q11.21. It is composed of 21 exons and encodes a transmembrane receptor tyrosine kinase. RET regulates a complex network of signal transduction pathways during development, survival, proliferation, differentiation, and migration of the enteric nervous system progenitor cells. Gain of function mutations in RET have been well demonstrated in MTC development. Variants of MTC result from different RET mutations, and they have a good genotype-phenotype correlation. Various MTC related mutations have been reported in different exons of the RET gene. We proposed that RET genetic mutations may be different in distinct populations. Therefore, the aim of this study was to find a geographical pattern of RET mutations in different populations. PMID:26678667

  5. An encyclopedia of mouse DNA elements (Mouse ENCODE).

    PubMed

    Stamatoyannopoulos, John A; Snyder, Michael; Hardison, Ross; Ren, Bing; Gingeras, Thomas; Gilbert, David M; Groudine, Mark; Bender, Michael; Kaul, Rajinder; Canfield, Theresa; Giste, Erica; Johnson, Audra; Zhang, Mia; Balasundaram, Gayathri; Byron, Rachel; Roach, Vaughan; Sabo, Peter J; Sandstrom, Richard; Stehling, A Sandra; Thurman, Robert E; Weissman, Sherman M; Cayting, Philip; Hariharan, Manoj; Lian, Jin; Cheng, Yong; Landt, Stephen G; Ma, Zhihai; Wold, Barbara J; Dekker, Job; Crawford, Gregory E; Keller, Cheryl A; Wu, Weisheng; Morrissey, Christopher; Kumar, Swathi A; Mishra, Tejaswini; Jain, Deepti; Byrska-Bishop, Marta; Blankenberg, Daniel; Lajoie, Bryan R; Jain, Gaurav; Sanyal, Amartya; Chen, Kaun-Bei; Denas, Olgert; Taylor, James; Blobel, Gerd A; Weiss, Mitchell J; Pimkin, Max; Deng, Wulan; Marinov, Georgi K; Williams, Brian A; Fisher-Aylor, Katherine I; Desalvo, Gilberto; Kiralusha, Anthony; Trout, Diane; Amrhein, Henry; Mortazavi, Ali; Edsall, Lee; McCleary, David; Kuan, Samantha; Shen, Yin; Yue, Feng; Ye, Zhen; Davis, Carrie A; Zaleski, Chris; Jha, Sonali; Xue, Chenghai; Dobin, Alex; Lin, Wei; Fastuca, Meagan; Wang, Huaien; Guigo, Roderic; Djebali, Sarah; Lagarde, Julien; Ryba, Tyrone; Sasaki, Takayo; Malladi, Venkat S; Cline, Melissa S; Kirkup, Vanessa M; Learned, Katrina; Rosenbloom, Kate R; Kent, W James; Feingold, Elise A; Good, Peter J; Pazin, Michael; Lowdon, Rebecca F; Adams, Leslie B

    2012-08-13

    To complement the human Encyclopedia of DNA Elements (ENCODE) project and to enable a broad range of mouse genomics efforts, the Mouse ENCODE Consortium is applying the same experimental pipelines developed for human ENCODE to annotate the mouse genome.

  6. The oncogenic action of ionizing radiation on rat skin

    SciTech Connect

    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.

  7. Human cancers converge at the HIF-2alpha oncogenic axis.

    PubMed

    Franovic, Aleksandra; Holterman, Chet E; Payette, Josianne; Lee, Stephen

    2009-12-15

    , silencing these receptors phenocopies the loss of HIF-2alpha oncogenic activity, abrogating the serum-independent growth of human cancer cells in culture. Based on these data, we propose an alternative to the predominant view that cancers exploit independent autonomous growth pathways and reveal HIF-2alpha as a potentially universal culprit in promoting the persistent proliferation of neoplastic cells. PMID:19955413

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

    PubMed

    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.

  9. Involvement of oncogenes in radon-induced lung tumors in rats

    SciTech Connect

    Foreman, M.E.; McCoy, L.S.; Frazier, M.E.

    1992-12-31

    Several oncogenes, notably those of the ras and myc family, have been implicated in the induction of lung tumors. Although inhalation of radon and radon daughters has been shown to result in a high incidence of lung tumors, the role of oncogenes in these tumors (if any) remains unknown. In certain cases of chemically induced carcinogenesis, unique point mutations in the 12th, 59th, and 61st codons of H-ras and Ki-ras have been found to transform ras proto-oncogenes to dominant-acting oncogenes. We have isolated DNA from fixed, archived, radon-induced tumors in rats, amplified the oncogene of interest by polymerase chain reaction, and analyzed it by sequencing. Although we have not found any of the classically described point mutations in the H-ras gene, preliminary evidence indicates that several common mutations occur with high frequency in the second exon. These point mutations have not been seen in any {open_quotes}spontaneously{close_quotes} occurring tumors. At present we theorize that these mutations represent one of the secondary effects of a multi-step process in the development of these lung tumors. As this project expands, we are making a systematic effort to correlate the molecular data with the pathological data derived from the original studies of these archived tumors.

  10. Regulation of autophagy and chloroquine sensitivity by oncogenic RAS in vitro is context-dependent.

    PubMed

    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.

  11. Limited Role of Murine ATM in Oncogene-Induced Senescence and p53-Dependent Tumor Suppression

    PubMed Central

    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

  12. Transforming but not immortalizing oncogenes activate the transcription factor PEA1.

    PubMed Central

    Wasylyk, C; Imler, J L; Wasylyk, B

    1988-01-01

    The transcription factor PEA1 (a homologue of AP1 and c-jun) is highly active in several fibroblast cell lines, compared to its low activity in a myeloma and an embryo-carcinoma (EC) cell line. Serum components are essential to attain these high levels of PEA1 activity in fibroblasts. This serum requirement is abrogated by transformation with the oncogenes c-Ha-ras, v-src and polyoma middle T (Py-MT) but not by immortalization with polyoma large T (Py-LT), v-myc, c-myc or SV40 large T (SV40T). Expression in myeloma cells of the same transforming oncogenes, as well as v-mos and c-fos, activates PEA1, whereas expression of the same immortalizing oncogenes and EIA does not. These results suggest that a common target for transforming oncogenes is PEA1. Serum components have no effect on PEA1 activity in the myeloma and EC cell lines. In contrast, retinoic acid treatment of F9 EC cells augments PEA1 activity. These results suggest that transforming oncogene expression compensates for the absence of cell type-specific factors which are required to activate PEA1. Activation of PEA1 may lead to altered transcription of a set of transformation-related genes. Images PMID:3142763

  13. Constitutive asymmetric dimerization drives oncogenic activation of epidermal growth factor receptor carboxyl-terminal deletion mutants

    PubMed Central

    Park, Angela K.J.; Francis, Joshua M.; Park, Woong-Yang; Park, Joon-Oh; Cho, Jeonghee

    2015-01-01

    Genomic alterations targeting the Epidermal Growth Factor Receptor (EGFR) gene have been strongly associated with cancer pathogenesis. The clinical effectiveness of EGFR targeted therapies, including small molecules directed against the kinase domain such as gefitinib, erlotinib and afatinib, have been proven successful in treating non-small cell lung cancer patients with tumors harboring EGFR kinase domain mutations. Recent large-scale genomic studies in glioblastoma and lung cancer have identified an additional class of oncogenic mutations caused by the intragenic deletion of carboxy-terminal coding regions. Here, we report that combinations of exonic deletions of exon 25 to 28 lead to the oncogenic activation of EGF receptor in the absence of ligand and consequent cellular transformation, indicating a significant role of C-terminal domain in modulating EGFR activation. Furthermore, we show that the oncogenic activity of the resulting C-terminal deletion mutants are efficiently inhibited by EGFR-targeted drugs including erlotinib, afatinib, dacomitinib as well as cetuximab, expanding the therapeutic rationale of cancer genome-based EGFR targeted approaches. Finally, in vivo and in vitro preclinical studies demonstrate that constitutive asymmetric dimerization in mutant EGFR is a key mechanism for oncogenic activation and tumorigenesis by C-terminal deletion mutants. Therefore, our data provide compelling evidence for oncogenic activation of C-terminal deletion mutants at the molecular level and we propose that C-terminal deletion status of EGFR can be considered as a potential genomic marker for EGFR-targeted therapy. PMID:25826094

  14. Preventing and exploiting the oncogenic potential of integrating gene vectors.

    PubMed

    Modlich, Ute; Baum, Christopher

    2009-04-01

    Gene therapy requires efficient gene delivery to cure or prevent disease by modifying the genome of somatic cells. However, gene vectors, which insert themselves into the host genome in order to achieve persistent protein expression, can trigger oncogenesis by upregulating cellular protooncogenes. This adverse event, known as insertional mutagenesis, has become a major hurdle in the field. Vectors developed on the basis of lentiviruses are considered to be less genotoxic than the hitherto used gamma-retroviral vectors. For their report in this issue of the JCI, Montini et al. utilized a tumor-prone mouse model to identify the genetic determinants of insertional mutagenesis (see the related article beginning on page 964). They report that the lentiviral integration pattern and additional improvements in vector design reduce the genotoxic risk. These findings will inform future vector design with the goal of limiting genotoxicity for gene therapy or increasing genotoxicity for protooncogene discovery.

  15. The MOUSE Squad

    ERIC Educational Resources Information Center

    Borja, Rhea R.

    2004-01-01

    This article presents a New York city after-school program started by MOUSE (Making Opportunities for Upgrading Schools and Education), a national nonprofit group that teaches students how to fix computers, and equips them with the communication and problem-solving skills to help them in the working world. The MOUSE program is part of a trend…

  16. Mouse genome database 2016.

    PubMed

    Bult, Carol J; Eppig, Janan T; Blake, Judith A; Kadin, James A; Richardson, Joel E

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data.

  17. Mouse genome database 2016

    PubMed Central

    Bult, Carol J.; Eppig, Janan T.; Blake, Judith A.; Kadin, James A.; Richardson, Joel E.

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data. PMID:26578600

  18. Mouse genome database 2016.

    PubMed

    Bult, Carol J; Eppig, Janan T; Blake, Judith A; Kadin, James A; Richardson, Joel E

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data. PMID:26578600

  19. Pancreatitis-induced Inflammation Contributes to Pancreatic Cancer by Inhibiting Oncogene-Induced Senescence

    PubMed Central

    Guerra, Carmen; Collado, Manuel; Navas, Carolina; Schuhmacher, Alberto J; Hernández-Porras, Isabel; Cañamero, Marta; Rodriguez-Justo, Manuel; Serrano, Manuel; Barbacid, Mariano

    2016-01-01

    Pancreatic acinar cells of adult mice (≥P60) are resistant to transformation by some of the most robust oncogenic insults including expression of K-Ras oncogenes and loss of p16Ink4a/p19Arf or Trp53 tumor suppressors. Yet, these acinar cells yield pancreatic intraepithelial neoplasias (mPanIN) and ductal adenocarcinomas (mPDAC) if exposed to limited bouts of non-acute pancreatitis, providing they harbor K-Ras oncogenes. Pancreatitis contributes to tumor progression by abrogating the senescence barrier characteristic of low-grade mPanINs. Attenuation of pancreatitis-induced inflammation also accelerates tissue repair and thwarts mPanIN expansion. Patients with chronic pancreatitis display senescent PanINs, if they have received anti-inflammatory drugs. These results put forward the concept that anti-inflammatory treatment of people diagnosed with pancreatitis may reduce their risk of developing PDAC. PMID:21665147

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

    PubMed

    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.

  1. Role of "oncogenic nexus" of CIP2A in breast oncogenesis: how does it work?

    PubMed

    De, Pradip; Carlson, Jennifer H; Leyland-Jones, Brian; Dey, Nandini

    2015-01-01

    The CIP2A gene is an oncogene associated with solid and hematologic malignancies [1]. CIP2A protein is an oncoprotein and a potential cancer therapy target [2]. Literature shows that CIP2A inhibits the tumor suppressor protein PP2A [3] which downregulates phophorylation of AKT, a hallmark of cancers [4] and stabilizes the proto-oncogene, c-MYC in tumor cells [5], the comprehensive action of CIP2A and its functional interaction(s) with other oncoproteins and tumor suppressors is not clearly established. Recently we tried to put forward a contextual mode-of-action of CIP2A protein in a review which proposed that CIP2A influences oncogenesis via an "oncogenic nexus" [1]. In this review we critically evaluated the potential relevance of the mode-of-action of the "oncogenic nexus" of CIP2A in breast carcinogenesis and appraised the role of this nexus in different PAM50 luminal A, PAM50 luminal B, PAM50 HER2-enriched and PAM50 basal BC. This review has a novel approach. Here we have not only compiled and discussed the latest developments in this field but also presented data obtained from c-BioPortal and STRING10 in order to substantiate our view regarding the mode-of-action of the "oncogenic nexus" of CIP2A. We functionally correlated alterations of genes pertaining to the "oncogenic nexus" of CIP2A with protein-protein interactions between the different components of the nexus including (1) subunits of PP2A, (2) multiple transcription factors including MYC oncogene and (3) components of the PI3K-mTOR and the MAPK-ERK oncogenic pathways. Using these proteins as "input" to STRING10 we studied the association, Action view, at the highest Confidence level. OncoPrints (c-BioPortal) showed alterations (%) of regulatory subunits genes of PP2A (PPP2R1A and PPP2R1B) along with alterations of CIP2A in breast invasive carcinoma (TCGA, Nature 2012 & TCGA, Provisional). Similar genetic alterations of PP2A were also observed in samples of breast tumors at our Avera Research

  2. Role of papillomavirus oncogenes in human cervical cancer: Transgenic animal studies

    SciTech Connect

    Griep, A.E.; Lambert, P.F.

    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.

  3. Identification of Oncogenic Mutations and Gene Fusions in the Follicular Variant of Papillary Thyroid Carcinoma

    PubMed Central

    Dias-Santagata, Dora; Sadow, Peter M.; Lynch, Kerry D.; Lubitz, Carrie; Donovan, Samuel E.; Zheng, Zongli; Le, Long; Iafrate, A. J.; Daniels, Gilbert H.

    2014-01-01

    Background: The diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) is increasingly common. Recent studies have suggested that FVPTC is heterogeneous and comprises multiple tumor types with distinct biological behaviors and underlying genetics. Objectives: The purpose of this work was to identify the prevalence of mutations and gene fusions in known oncogenes in a panel representative of the common spectrum of FVPTC diagnosed at an academic medical center and correlate the clinical and pathological features obtained at the initial diagnosis with the tumor genotype. Materials and Methods: We performed SNaPshot genotyping on a panel of 129 FVPTCs of ≥1 cm for 90 point mutations or small deletions in known oncogenes and tumor suppressors and identified gene fusions using an anchored multiplex PCR assay targeting a panel of rearranged oncogenes. Results: We identified a mutation or gene fusion in 70% (89 of 127) of cases. Mutations targeting the RAS family of oncogenes were the most frequently observed class of alterations, present in 36% (46 of 127) of cases, followed by BRAF mutation, present in 30% (38 of 127). We also detected oncogenic rearrangements not previously associated with FVPTC, including TFG-ALK and CREB3L2-PPARγ. BRAF mutation was significantly associated with unencapsulated tumor status. Conclusions: These data support the hypothesis that FVPTC is composed of distinct biological entities, with one class being identified by BRAF mutation and support the use of clinical genotyping assays that detect a diverse array of rearrangements involving ALK and PPARγ. Additional studies are necessary to identify genetic drivers in the 30% of FVPTCs with no known oncogenic alteration and to better predict behavior in tumors with known genotypes. PMID:25148236

  4. ONCOGENIC HUMAN PAPILLOMAVIRUS (HPV) INFECTIONS IN 18 TO 24 YEAR OLD FEMALE ONLINE DATERS

    PubMed Central

    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

  5. Common Oncogenic Mutations Are Infrequent in Oral Squamous Cell Carcinoma of Asian Origin

    PubMed Central

    Zanaruddin, Sharifah Nurain Syed; Yee, Pei San; Hor, Seen Yii; Kong, Yink Heay; Ghani, Wan Maria Nabillah Wan Abd; Mustafa, Wan Mahadzir Wan; Zain, Rosnah Binti; Prime, Stephen S.; Rahman, Zainal Ariff Abd; Cheong, Sok-Ching

    2013-01-01

    Objectives The frequency of common oncogenic mutations and TP53 was determined in Asian oral squamous cell carcinoma (OSCC). Materials and Methods The OncoCarta™ panel v1.0 assay was used to characterize oncogenic mutations. In addition, exons 4-11 of the TP53 gene were sequenced. Statistical analyses were conducted to identify associations between mutations and selected clinico-pathological characteristics and risk habits. Results Oncogenic mutations were detected in PIK3CA (5.7%) and HRAS (2.4%). Mutations in TP53 were observed in 27.7% (31/112) of the OSCC specimens. Oncogenic mutations were found more frequently in non-smokers (p = 0.049) and TP53 truncating mutations were more common in patients with no risk habits (p = 0.019). Patients with mutations had worse overall survival compared to those with absence of mutations; and patients who harbored DNA binding domain (DBD) and L2/L3/LSH mutations showed a worse survival probability compared to those patients with wild type TP53. The majority of the oncogenic and TP53 mutations were G:C > A:T and A:T > G:C base transitions, regardless of the different risk habits. Conclusion Hotspot oncogenic mutations which are frequently present in common solid tumors are exceedingly rare in OSCC. Despite differences in risk habit exposure, the mutation frequency of PIK3CA and HRAS in Asian OSCC were similar to that reported in OSCC among Caucasians, whereas TP53 mutations rates were significantly lower. The lack of actionable hotspot mutations argue strongly for the need to comprehensively characterize gene mutations associated with OSCC for the development of new diagnostic and therapeutic tools. PMID:24224046

  6. Cyclic AMP suppresses expression of v-rasH oncogene linked to the mouse mammary tumor virus promoter.

    PubMed

    Najam, N; Clair, T; Bassin, R H; Cho-Chung, Y S

    1986-01-14

    Clone 433.3 of NIH 3T3 cells is a stable carrier of the MMTV LTR:v-rasH chimeric DNA. Only in the presence of dexamethasone (a synthetic glucocorticoid), 433.3 cells exhibit an induced level of p21 transforming protein and phenotypic transformation. N6,O2'-dibutyryl cAMP (DBcAMP) antagonized the effect of dexamethasone in a time - and concentration - dependent manner. DBcAMP (5 X 10(-4)M) added 18 hr prior to the addition of dexamethasone (10(-7)M) almost completely blocked the hormone effect: cells contained levels of p21 20% of that in the cells treated with dexamethasone alone, and formed flat, contact inhibited monolayers. On the basis of these results together with our previous data on mammary carcinomas in vivo, we postulate that cAMP may be an intracellular suppressor acting at a regulatory locus of both cellular and viral ras genes.

  7. LTβR signalling preferentially accelerates oncogenic AKT-initiated liver tumours

    PubMed Central

    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

  8. Using Multiplexed Assays of Oncogenic Drivers in Lung Cancers to Select Targeted Drugs

    PubMed Central

    Kris, Mark G.; Johnson, Bruce E.; Berry, Lynne D.; Kwiatkowski, David J.; Iafrate, A. John; Wistuba, Ignacio I.; Varella-Garcia, Marileila; Franklin, Wilbur A.; Aronson, Samuel L.; Su, Pei-Fang; Shyr, Yu; Camidge, D. Ross; Sequist, Lecia V.; Glisson, Bonnie S.; Khuri, Fadlo R.; Garon, Edward B.; Pao, William; Rudin, Charles; Schiller, Joan; Haura, Eric B.; Socinski, Mark; Shirai, Keisuke; Chen, Heidi; Giaccone, Giuseppe; Ladanyi, Marc; Kugler, Kelly; Minna, John D.; Bunn, Paul A.

    2014-01-01

    IMPORTANCE Targeting oncogenic drivers (genomic alterations critical to cancer development and maintenance) has transformed the care of patients with lung adenocarcinomas. The Lung Cancer Mutation Consortium was formed to perform multiplexed assays testing adenocarcinomas of the lung for drivers in 10 genes to enable clinicians to select targeted treatments and enroll patients into clinical trials. OBJECTIVES To determine the frequency of oncogenic drivers in patients with lung adenocarcinomas and to use the data to select treatments targeting the identified driver(s) and measure survival. DESIGN, SETTING, AND PARTICIPANTS From 2009 through 2012, 14 sites in the United States enrolled patients with metastatic lung adenocarcinomas and a performance status of 0 through 2 and tested their tumors for 10 drivers. Information was collected on patients, therapies, and survival. INTERVENTIONS Tumors were tested for 10 oncogenic drivers, and results were used to select matched targeted therapies. MAIN OUTCOMES AND MEASURES Determination of the frequency of oncogenic drivers, the proportion of patients treated with genotype-directed therapy, and survival. RESULTS From 2009 through 2012, tumors from 1007 patients were tested for at least 1 gene and 733 for 10 genes (patients with full genotyping). An oncogenic driver was found in 466 of 733 patients (64%). Among these 733 tumors, 182 tumors (25%) had the KRAS driver; sensitizing EGFR, 122 (17%); ALK rearrangements, 57 (8%); other EGFR, 29 (4%); 2 or more genes, 24 (3%); ERBB2 (formerly HER2), 19 (3%); BRAF, 16 (2%); PIK3CA, 6 (<1%); MET amplification, 5 (<1%); NRAS, 5 (<1%); MEK1, 1 (<1%); AKT1, 0. Results were used to select a targeted therapy or trial in 275 of 1007 patients (28%). The median survival was 3.5 years (interquartile range [IQR], 1.96-7.70) for the 260 patients with an oncogenic driver and genotype-directed therapy compared with 2.4 years (IQR, 0.88-6.20) for the 318 patients with any oncogenic driver(s) who

  9. Detection of K-ras oncogene mutations & DNA adducts in the lungs of strain A/J mice exposed to benzo[b]fluoranthene (B[b]F)

    SciTech Connect

    Abu-Shakra, A.; Roop, B.C.; Nelson, G.

    1995-11-01

    The polycyclic aromatic hydrocarbon benzo[b]fluoranthene (B[b]F) has been shown in our laboratories to induce adenomas in strain A/J mouse lungs using i.p. doses above 50 mg/kg body weight. B[b]F appears to be less potent than benzo[a]pyrene on a mg/kg basis in this tumor model. We measured the formation of B[b]F-DNA adducts in mice exposed to B[b]F after 1-21 days and analyzed B[b]F-induced tumors for K-ras oncogene mutations approximately 8 months later. The major B[b]F-DNA adduct comigrated with an adduct seen after application of 5-hydroxy-B[b]F-9,10-dihydrodiol-11,12-oxide to mouse skin. Tumor DNA was extracted and amplified by the polymerase chain reaction (PCR) using primers flanking the 111 bp region of exon 1. Samples were sequenced using the dideoxy method; those samples that failed to show a clear sequence after repetitive sequencing were subjected to single stranded conformation polymorphism analysis (SSCP). B[b]F-induced tumors with K-ras mutations in codon 12, had the following distribution: GGT {yields}GTT, 50%; GGT{yields}TGT, 40%; GGT{yields} 10%. Further characterization of these mutations and their relationship to B[b]F-DNA adducts is in progress

  10. Mouse and hamster mutants as models for Waardenburg syndromes in humans.

    PubMed Central

    Asher, J H; Friedman, T B

    1990-01-01

    Four different Waardenburg syndromes have been defined based upon observed phenotypes. These syndromes are responsible for approximately 2% of subjects with profound congenital hearing loss. At present, Waardenburg syndromes have not been mapped to particular human chromosomes. One or more of the mouse mutant alleles, Ph (patch), s (piebald), Sp (splotch), and Mior (microphthalmia-Oak Ridge) and the hamster mutation Wh (anophthalmic white) may be homologous to mutations causing Waardenburg syndromes. In heterozygotes, phenotypic effects of these four mouse mutations and the hamster mutation are similar to the phenotypes produced by different Waardenburg syndrome mutations. The chromosomal locations and syntenic relationships associated with three of the four mouse mutant genes have been used to predict human chromosomal locations for Waardenburg syndromes: (1) on chromosome 2q near FN1 (fibronectin 1), (2) on chromosome 3p near the proto-oncogene RAF1 or 3q near RHO (rhodopsin), and (3) on chromosome 4p near the proto-oncogene KIT. Waardenburg syndromes show extensive intrafamilial phenotypic variability. Results of our studies with the hamster mutation Wh suggest that this variability may be explained in part by modifier genes segregating within families. Images PMID:2246770

  11. Mouse models of p53 functions.

    PubMed

    Lozano, Guillermina

    2010-04-01

    Studies in mice have yielded invaluable insight into our understanding of the p53 pathway. Mouse models with activated p53, no p53, and mutant p53 have queried the role of p53 in development and tumorigenesis. In these models, p53 is activated and stabilized via redundant posttranslational modifications. On activation, p53 initiates two major responses: inhibition of proliferation (via cell-cycle arrest, quiescence, senescence, and differentiation) and induction of apoptosis. Importantly, these responses are cell-type and tumor-type-specific. The analysis of mutant p53 alleles has established a gain-of-function role for p53 mutants in metastasis. The development of additional models that can precisely time the oncogenic events in single cells will provide further insight into the evolution of tumors, the importance of the stroma, and the cooperating events that lead to disruption of the p53 pathway. Ultimately, these models should serve to study the effects of novel drugs on tumor response as well as normal homeostasis.

  12. Comparative Evaluation of Vaccine Efficacy of Recombinant Marek's Disease Virus Vaccine Lacking Meq Oncogene in Commercial Chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek's disease virus oncogene meq has been identified as the gene involved in tumorigenesis in chickens. We have recently developed a Meq-null virus, rMd5delMeq, in which the oncogene Meq was deleted. Vaccine efficacy experiments conducted in ADOL 15I5 x 71 chickens vaccinated with rMd5delMeq virus...

  13. Sleeping Beauty mouse models identify candidate genes involved in gliomagenesis.

    PubMed

    Vyazunova, Irina; Maklakova, Vilena I; Berman, Samuel; De, Ishani; Steffen, Megan D; Hong, Won; Lincoln, Hayley; Morrissy, A Sorana; Taylor, Michael D; Akagi, Keiko; Brennan, Cameron W; Rodriguez, Fausto J; Collier, Lara S

    2014-01-01

    Genomic studies of human high-grade gliomas have discovered known and candidate tumor drivers. Studies in both cell culture and mouse models have complemented these approaches and have identified additional genes and processes important for gliomagenesis. Previously, we found that mobilization of Sleeping Beauty transposons in mice ubiquitously throughout the body from the Rosa26 locus led to gliomagenesis with low penetrance. Here we report the characterization of mice in which transposons are mobilized in the Glial Fibrillary Acidic Protein (GFAP) compartment. Glioma formation in these mice did not occur on an otherwise wild-type genetic background, but rare gliomas were observed when mobilization occurred in a p19Arf heterozygous background. Through cloning insertions from additional gliomas generated by transposon mobilization in the Rosa26 compartment, several candidate glioma genes were identified. Comparisons to genetic, epigenetic and mRNA expression data from human gliomas implicates several of these genes as tumor suppressor genes and oncogenes in human glioblastoma.

  14. Mouse Cleaning Apparatus and Method

    NASA Technical Reports Server (NTRS)

    Williams, Glenn L. (Inventor)

    2005-01-01

    The method of using the mouse pad cleaning apparatus is disclosed and claimed. The method comprises the steps of uncovering the mouse cleaning surface, applying the mouse and ball of the mouse to the cleaning surface, moving the mouse in a rotational pattern on the mouse cleaning surface, removing the mouse form the mouse cleaning surface, washing the cleaning surface, and covering the mouse cleaning surface. A mouse pad cleaning apparatus comprising a plurality of substrates, each said substrate having adhesive thereon, said plurality of substrates residing in and affixed to a receptacle. A single substrate having adhesive, which may be washable or non-washable, thereon may be employed. The washable adhesive may be an organopolysiloxane or gelatinous elastomer.

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

    PubMed

    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

  16. Modeling Prolactin Actions in Breast Cancer in vivo: Insights from the NRL-PRL Mouse

    PubMed Central

    O'Leary, Kathleen A.; Shea, Michael P.; Schuler, Linda A.

    2016-01-01

    Elevated exposure to prolactin is epidemiologically associated with an increased risk of aggressive ER+ breast cancer. To understand the underlying mechanisms and crosstalk with other oncogenic factors, we developed the NRL-PRL mouse. In this model, mammary expression of a rat prolactin transgene raises local exposure to prolactin without altering estrous cycling. Nulliparous females develop metastatic, histotypically diverse mammary carcinomas independent from ovarian steroids, and most are ER+. These characteristics resemble the human clinical disease, facilitating study of tumorigenesis, and identification of novel preventive and therapeutic approaches. PMID:25472540

  17. Global Impact of Oncogenic Src on a Phosphotyrosine Proteome

    PubMed Central

    Luo, Weifeng; Slebos, Robbert J.; Hill, Salisha; Li, Ming; Brábek, Jan; Amanchy, Ramars; Chaerkady, Raghothama; Pandey, Akhilesh; Ham, Amy-Joan L.; Hanks, Steven K.

    2008-01-01

    Elevated activity of Src, the first characterized protein-tyrosine kinase, is associated with progression of many human cancers, and Src has attracted interest as a therapeutic target. Src is known to act in various receptor signaling systems to impact cell behavior, yet it remains likely that the spectrum of Src protein substrates relevant to cancer is incompletely understood. To better understand the cellular impact of deregulated Src kinase activity, we extensively applied a mass spectrometry shotgun phosphotyrosine (pTyr) proteomics strategy to obtain global pTyr profiles of Src-transformed mouse fibroblasts as well as their nontransformed counterparts. A total of 867 peptides representing 563 distinct pTyr sites on 374 different proteins were identified from the Src-transformed cells, while 514 peptides representing 275 pTyr sites on 167 proteins were identified from nontransformed cells. Distinct characteristics of the two profiles were revealed by spectral counting, indicative of pTyr site relative abundance, and by complementary quantitative analysis using stable isotope labeling with amino acids in cell culture (SILAC). While both pTyr profiles are replete with sites on signaling and adhesion/cytoskeletal regulatory proteins, the Src-transformed profile is more diverse with enrichment in sites on metabolic enzymes and RNA and protein synthesis and processing machinery. Forty-three pTyr sites (32 proteins) are predicted as major biologically relevant Src targets on the basis of frequent identification in both cell populations. This select group, of particular interest as diagnostic biomarkers, includes well-established Src sites on signaling/adhesion/cytoskeletal proteins, but also uncharacterized sites of potential relevance to the transformed cell phenotype. PMID:18563927

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

    PubMed Central

    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

  19. Repeat-element driven activation of proto-oncogenes in human malignancies.

    PubMed

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

    PubMed

    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.

  1. Power of PTEN/AKT: Molecular switch between tumor suppressors and oncogenes

    PubMed Central

    XIE, YINGQIU; NAIZABEKOV, SANZHAR; CHEN, ZHANLIN; TOKAY, TURSONJAN

    2016-01-01

    An increasing amount of evidence has shown that tumor suppressors can become oncogenes, or vice versa, but the mechanism behind this is unclear. Recent findings have suggested that phosphatase and tensin homolog (PTEN) is one of the powerful switches for the conversion between tumor suppressors and oncogenes. PTEN regulates a number of cellular processes, including cell death and proliferation, through the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. Furthermore, a number of studies have suggested that PTEN deletions may alter various functions of certain tumor suppressor and oncogenic proteins. The aim of the present review was to analyze specific cases driven by PTEN loss/AKT activation, including aberrant signaling pathways and novel drug targets for clinical application in personalized medicine. The findings illustrate how PTEN loss and/or AKT activation switches MDM2-dependent p53 downregulation, and induces conversion between oncogene and tumor suppressor in enhancer of zeste homolog 2, BTB domain-containing 7A, alternative reading frame 2, p27 and breast cancer 1, early onset, through multiple mechanisms. This review highlights the genetic basis of complex drug targets and provides insights into the rationale of precision cancer therapy. PMID:27347153

  2. Significance of hepatitis virus infection in the oncogenic initiation of hepatocellular carcinoma

    PubMed Central

    Sukowati, Caecilia HC; El-Khobar, Korri E; Ie, Susan I; Anfuso, Beatrice; Muljono, David H; Tiribelli, Claudio

    2016-01-01

    Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. Chronic infection of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) is a major risk factor in the development of the HCC, independently from excessive alcohol abuse and metabolic disease. Since the biology of HBV and HCV is different, their oncogenic effect may go through different mechanisms, direct and/or indirect. Viral hepatitis infection is associated with cellular inflammation, oxidative stress, and DNA damage, that may lead to subsequent hepatic injuries such as chronic hepatitis, fibrosis, cirrhosis, and finally HCC. Direct oncogenic properties of these viruses are related with their genotypic characteristics and the ability of viral proteins to interact with host proteins, thus altering the molecular pathways balance of the cells. In addition, the integration of HBV DNA, especially the gene S and X, in a particular site of the host genome can disrupt chromosomal stability and may activate various oncogenic mechanisms, including those in hematopoietic cells. Recently, several studies also had demonstrated that viral hepatitis could trigger the population of hepatic cancer stem cells. This review summarize available pre-clinical and clinical data in literature regarding oncogenic properties of HBV and HCV in the early initiation of HCC. PMID:26819517

  3. Somatic Copy Number Alterations at Oncogenic Loci Show Diverse Correlations with Gene Expression

    NASA Astrophysics Data System (ADS)

    Roszik, Jason; Wu, Chang-Jiun; Siroy, Alan E.; Lazar, Alexander J.; Davies, Michael A.; Woodman, Scott E.; Kwong, Lawrence N.

    2016-01-01

    Somatic copy number alterations (SCNAs) affecting oncogenic drivers have a firmly established role in promoting cancer. However, no agreed-upon standard exists for calling locus-specific amplifications and deletions in each patient sample. Here, we report the correlative analysis of copy number amplitude and length with gene expression across 6,109 samples from The Cancer Genome Atlas (TCGA) dataset across 16 cancer types. Using specificity, sensitivity, and precision-based scores, we assigned optimized amplitude and length cutoffs for nine recurrent SCNAs affecting known oncogenic drivers, using mRNA expression as a functional readout. These cutoffs captured the majority of SCNA-driven, highly-expression-altered samples. The majority of oncogenes required only amplitude cutoffs, as high amplitude samples were almost invariably focal; however, CDKN2A and PTEN uniquely required both amplitude and length cutoffs as primary predictors. For PTEN, these extended to downstream AKT activation. In contrast, SCNA genes located peri-telomerically or in fragile sites showed poor expression-copy number correlations. Overall, our analyses identify optimized amplitude and length cutoffs as efficient predictors of gene expression changes for specific oncogenic SCNAs, yet warn against one-size-fits-all interpretations across all loci. Our results have implications for cancer data analyses and the clinic, where copy number and mutation data are increasingly used to personalize cancer therapy.

  4. Derepression of hTERT gene expression promotes escape from oncogene-induced cellular senescence.

    PubMed

    Patel, Priyanka L; Suram, Anitha; Mirani, Neena; Bischof, Oliver; Herbig, Utz

    2016-08-23

    Oncogene-induced senescence (OIS) is a critical tumor-suppressing mechanism that restrains cancer progression at premalignant stages, in part by causing telomere dysfunction. Currently it is unknown whether this proliferative arrest presents a stable and therefore irreversible barrier to cancer progression. Here we demonstrate that cells frequently escape OIS induced by oncogenic H-Ras and B-Raf, after a prolonged period in the senescence arrested state. Cells that had escaped senescence displayed high oncogene expression levels, retained functional DNA damage responses, and acquired chromatin changes that promoted c-Myc-dependent expression of the human telomerase reverse transcriptase gene (hTERT). Telomerase was able to resolve existing telomeric DNA damage response foci and suppressed formation of new ones that were generated as a consequence of DNA replication stress and oncogenic signals. Inhibition of MAP kinase signaling, suppressing c-Myc expression, or inhibiting telomerase activity, caused telomere dysfunction and proliferative defects in cells that had escaped senescence, whereas ectopic expression of hTERT facilitated OIS escape. In human early neoplastic skin and breast tissue, hTERT expression was detected in cells that displayed features of senescence, suggesting that reactivation of telomerase expression in senescent cells is an early event during cancer progression in humans. Together, our data demonstrate that cells arrested in OIS retain the potential to escape senescence by mechanisms that involve derepression of hTERT expression. PMID:27503890

  5. Oncogene expression in vivo by ovarian adenocarcinomas and mixed-mullerian tumors.

    PubMed Central

    Kacinski, B. M.; Carter, D.; Kohorn, E. I.; Mittal, K.; Bloodgood, R. S.; Donahue, J.; Kramer, C. A.; Fischer, D.; Edwards, R.; Chambers, S. K.

    1989-01-01

    Six-micron paraffin sections of paraformaldehyde-fixed specimens of 24 ovarian benign and neoplastic specimens were assayed for tumor cell-specific oncogene expression by a sensitive, quantitative in situ hybridization technique with probes for 17 oncogenes, beta-actin, and E. coli beta-lactamase. In the benign, borderline, and invasive adenocarcinomas, multiple oncogenes, including neu, fes, fms, Ha-ras, trk, c-myc, fos, and PDGF-A chains, were expressed at significant levels relative to a housekeeping gene (beta-actin). In the mixed-Mullerian tumors, a rather different pattern of oncogene expression was observed, characterized primarily by expression of sis (PDGF-B chain). For the adenocarcinomas, statistical analysis demonstrated that expression of several genes (fms, neu, PDGF-A) was closely linked to others (c-fos, c-myc) known to have important roles in the control of cell proliferation, but only one gene, fms, correlated very strongly with clinicopathologic features (high FIGO histologic grade and high FIGO clinical stage) predictive of aggressive clinical behavior and poor outcome. The authors discuss the role that tumor epithelial cell expression of the fms gene product might play in the auto- and paracrine control of growth and dissemination of ovarian adenocarcinomas. Images FIG. 1 PMID:2556864

  6. Identification of kinase fusion oncogenes in post-Chernobyl radiation-induced thyroid cancers

    PubMed Central

    Ricarte-Filho, Julio C.; Li, Sheng; Garcia-Rendueles, Maria E.R.; Montero-Conde, Cristina; Voza, Francesca; Knauf, Jeffrey A.; Heguy, Adriana; Viale, Agnes; Bogdanova, Tetyana; Thomas, Geraldine A.; Mason, Christopher E.; Fagin, James A.

    2013-01-01

    Exposure to ionizing radiation during childhood markedly increases the risk of developing papillary thyroid cancer. We examined tissues from 26 Ukrainian patients with thyroid cancer who were younger than 10 years of age and living in contaminated areas during the time of the Chernobyl nuclear reactor accident. We identified nonoverlapping somatic driver mutations in all 26 cases through candidate gene assays and next-generation RNA sequencing. We found that 22 tumors harbored fusion oncogenes that arose primarily through intrachromosomal rearrangements. Altogether, 23 of the oncogenic drivers identified in this cohort aberrantly activate MAPK signaling, including the 2 somatic rearrangements resulting in fusion of transcription factor ETS variant 6 (ETV6) with neurotrophic tyrosine kinase receptor, type 3 (NTRK3) and fusion of acylglycerol kinase (AGK) with BRAF. Two other tumors harbored distinct fusions leading to overexpression of the nuclear receptor PPARγ. Fusion oncogenes were less prevalent in tumors from a cohort of children with pediatric thyroid cancers that had not been exposed to radiation but were from the same geographical regions. Radiation-induced thyroid cancers provide a paradigm of tumorigenesis driven by fusion oncogenes that activate MAPK signaling or, less frequently, a PPARγ-driven transcriptional program. PMID:24135138

  7. Somatic Copy Number Alterations at Oncogenic Loci Show Diverse Correlations with Gene Expression

    PubMed Central

    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. PMID:26787600

  8. Oncogene transcription in normal human IMR-90 fibroblasts: induction by serum and tetradecanoyl phorbol acetate

    SciTech Connect

    Bower, E.A.; Kaji, H.

    1988-01-01

    The authors report studies of oncogene transcription induced by the addition of serum to quiescent cultures of human IMR-90 fibroblasts. Oncogene messenger RNAs for c-myc, c-erbB and c-ras were increased in a specific temporal sequence after the addition of serum. Compounds that are proposed to exert their actions by the stimulation of cell growth were tested for their effect on oncogene transcription in IMR-90 fibroblasts. The tumor promoter tetradecanoyl phorbol acetate (TPA) was found to selectively induce the transcription of c-myc without observable effect on the transcription of the other oncogenes studied, and without inducing cell division. The inactive analog, phorbol didecanoate (PDD), and two complete carcinogens dimethylbenzanthracene (DMBA) and 4-nitro quinoline-1-oxide (4NQO) were without effect on the transcription of the genes studied. These results suggest that the complete ordered sequence of gene transcription is necessary to achieve the physiologic response of cell division, and that classical promoters and complete carcinogens achieve their effects through different pathways.

  9. Significance of hepatitis virus infection in the oncogenic initiation of hepatocellular carcinoma.

    PubMed

    Sukowati, Caecilia H C; El-Khobar, Korri E; Ie, Susan I; Anfuso, Beatrice; Muljono, David H; Tiribelli, Claudio

    2016-01-28

    Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related death worldwide. Chronic infection of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) is a major risk factor in the development of the HCC, independently from excessive alcohol abuse and metabolic disease. Since the biology of HBV and HCV is different, their oncogenic effect may go through different mechanisms, direct and/or indirect. Viral hepatitis infection is associated with cellular inflammation, oxidative stress, and DNA damage, that may lead to subsequent hepatic injuries such as chronic hepatitis, fibrosis, cirrhosis, and finally HCC. Direct oncogenic properties of these viruses are related with their genotypic characteristics and the ability of viral proteins to interact with host proteins, thus altering the molecular pathways balance of the cells. In addition, the integration of HBV DNA, especially the gene S and X, in a particular site of the host genome can disrupt chromosomal stability and may activate various oncogenic mechanisms, including those in hematopoietic cells. Recently, several studies also had demonstrated that viral hepatitis could trigger the population of hepatic cancer stem cells. This review summarize available pre-clinical and clinical data in literature regarding oncogenic properties of HBV and HCV in the early initiation of HCC. PMID:26819517

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

    PubMed

    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.

  11. Derepression of hTERT gene expression promotes escape from oncogene-induced cellular senescence

    PubMed Central

    Patel, Priyanka L.; Suram, Anitha; Mirani, Neena; Bischof, Oliver; Herbig, Utz

    2016-01-01

    Oncogene-induced senescence (OIS) is a critical tumor-suppressing mechanism that restrains cancer progression at premalignant stages, in part by causing telomere dysfunction. Currently it is unknown whether this proliferative arrest presents a stable and therefore irreversible barrier to cancer progression. Here we demonstrate that cells frequently escape OIS induced by oncogenic H-Ras and B-Raf, after a prolonged period in the senescence arrested state. Cells that had escaped senescence displayed high oncogene expression levels, retained functional DNA damage responses, and acquired chromatin changes that promoted c-Myc–dependent expression of the human telomerase reverse transcriptase gene (hTERT). Telomerase was able to resolve existing telomeric DNA damage response foci and suppressed formation of new ones that were generated as a consequence of DNA replication stress and oncogenic signals. Inhibition of MAP kinase signaling, suppressing c-Myc expression, or inhibiting telomerase activity, caused telomere dysfunction and proliferative defects in cells that had escaped senescence, whereas ectopic expression of hTERT facilitated OIS escape. In human early neoplastic skin and breast tissue, hTERT expression was detected in cells that displayed features of senescence, suggesting that reactivation of telomerase expression in senescent cells is an early event during cancer progression in humans. Together, our data demonstrate that cells arrested in OIS retain the potential to escape senescence by mechanisms that involve derepression of hTERT expression. PMID:27503890

  12. Oncogenic transformation by vrel requires an amino-terminal activation domain

    SciTech Connect

    Kamens, J.; Brent, R. . Dept. of Molecular Biology); Richardson, P.; Gilmore, T. . Dept. of Biology); Mosialos, G. . Dept. of Chemistry)

    1990-06-01

    The mechanism by which the products of the v-{ital rel} oncogene, the corresponding c-{ital rel} proto-oncogene, and the related {ital dorsal} gene of {ital Drosophila melanogaster} exert their effects is not clear. The authors show that the v-{ital rel}, chicken c-{ital rel}, and {ital dorsal} proteins activated gene expression when fused to LexA sequences and bound to DNA upstream of target genes in {ital Saccharomyces cerevisiae}. They have defined two distinct activation regions in the c-{ital rel} protein. Region I, located in the amino-terminal half of {ital rel} and {ital dorsal} proteins, contains no stretches of glutamines, prolines, or acidic amino acids and therefore may be a novel activation domain. Lesions in the v-{ital rel} protein that diminished or abolished oncogenic transformation of avian spleen cells correspondingly affected transcription activation by region I. Region II, located in the carboxy terminus of the c-{ital rel} protein, is highly acidic. Region II is not present in the v-{ital rel} protein or in a transforming mutant derivative of the c-{ital rel} protein. The authors' results show that the oncogenicity of Rel proteins requires activation region I and suggest that the biological function of {ital rel} and {ital dorsal} proteins depends on transcription activation by this region.

  13. Suppressor of cytokine signaling 1 interacts with oncogenic lymphocyte-specific protein tyrosine kinase.

    PubMed

    Venkitachalam, Srividya; Chueh, Fu-Yu; Leong, King-Fu; Pabich, Samantha; Yu, Chao-Lan

    2011-03-01

    Lymphocyte-specific protein tyrosine kinase (Lck) plays a key role in T cell signal transduction and is tightly regulated by phosphorylation and dephosphorylation. Lck can function as an oncoprotein when overexpressed or constantly activated by mutations. Our previous studies showed that Lck-induced cellular transformation could be suppressed by enforced expression of suppressor of cytokine signaling 1 (SOCS1), a SOCS family member involved in the negative feedback control of cytokine signaling. We observed attenuated Lck kinase activity in SOCS1-expressing cells, suggesting an important role of SOCS in regulating Lck functions. It remains largely unknown whether and how SOCS proteins interact with the oncogenic Lck kinase. Here, we report that among four SOCS family proteins, SOCS1, SOCS2, SOCS3 and CIS (cytokine-inducible SH2 domain containing protein), SOCS1 has the highest affinity in binding to the oncogenic Lck kinase. We identified the positive regulatory phosphotyrosine 394 residue in the kinase domain as the key interacting determinant in Lck. Additionally, the Lck kinase domain alone is sufficient to bind SOCS1. While the SH2 domain in SOCS1 is important in its association with the oncogenic Lck kinase, other functional domains may also contribute to overall binding affinity. These findings provide important mechanistic insights into the role of SOCS proteins as tumor suppressors in cells transformed by oncogenic protein tyrosine kinases.

  14. An enzyme-linked immunosorbent assay to screen for inhibitors of the oncogenic anaplastic lymphoma kinase.

    PubMed

    Gunby, Rosalind Helen; Tartari, Carmen Julia; Porchia, Francesca; Donella-Deana, Arianna; Scapozza, Leonardo; Gambacorti-Passerini, Carlo

    2005-07-01

    The discovery of novel anti-cancer drugs targeting anaplastic lymphoma kinase (ALK), an oncogenic tyrosine kinase, raises the need for in vitro assays suitable for screening compounds for ALK inhibition. To this aim we have developed and optimized an ALK-specific enzyme-linked immunosorbent assay that employs a novel ALK peptide substrate and purified ALK kinase domain. PMID:15996942

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

    PubMed

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

    2015-06-01

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

    PubMed

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

    2014-03-01

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

  17. Proto-oncogene FBI-1 represses transcription of p21CIP1 by inhibition of transcription activation by p53 and Sp1.

    PubMed

    Choi, Won-Il; Jeon, Bu-Nam; Yun, Chae-Ok; Kim, Pyung-Hwan; Kim, Sung-Eun; Choi, Kang-Yell; Kim, Se Hoon; Hur, Man-Wook

    2009-05-01

    Aberrant transcriptional repression through chromatin remodeling and histone deacetylation has been postulated as the driving force for tumorigenesis. FBI-1 (formerly called Pokemon) is a member of the POK family of transcriptional repressors. Recently, FBI-1 was characterized as a critical oncogenic factor that specifically represses transcription of the tumor suppressor gene ARF, potentially leading indirectly to p53 inactivation. Our investigations on transcriptional repression of the p53 pathway revealed that FBI-1 represses transcription of ARF, Hdm2 (human analogue of mouse double minute oncogene), and p21CIP1 (hereafter indicated as p21) but not of p53. FBI-1 showed a more potent repressive effect on p21 than on p53. Our data suggested that FBI-1 is a master controller of the ARF-Hdm2-p53-p21 pathway, ultimately impinging on cell cycle arrest factor p21, by inhibiting upstream regulators at the transcriptional and protein levels. FBI-1 acted as a competitive transcriptional repressor of p53 and Sp1 and was shown to bind the proximal Sp1-3 GC-box and the distal p53-responsive elements of p21. Repression involved direct binding competition of FBI-1 with Sp1 and p53. FBI-1 also interacted with corepressors, such as mSin3A, NCoR, and SMRT, thereby deacetylating Ac-H3 and Ac-H4 histones at the promoter. FBI-1 caused cellular transformation, promoted cell cycle proliferation, and significantly increased the number of cells in S phase. FBI-1 is aberrantly overexpressed in many human solid tumors, particularly in adenocarcinomas and squamous carcinomas. The role of FBI-1 as a master controller of the p53 pathway therefore makes it an attractive therapeutic target. PMID:19244234

  18. Proto-oncogene FBI-1 represses transcription of p21CIP1 by inhibition of transcription activation by p53 and Sp1.

    PubMed

    Choi, Won-Il; Jeon, Bu-Nam; Yun, Chae-Ok; Kim, Pyung-Hwan; Kim, Sung-Eun; Choi, Kang-Yell; Kim, Se Hoon; Hur, Man-Wook

    2009-05-01

    Aberrant transcriptional repression through chromatin remodeling and histone deacetylation has been postulated as the driving force for tumorigenesis. FBI-1 (formerly called Pokemon) is a member of the POK family of transcriptional repressors. Recently, FBI-1 was characterized as a critical oncogenic factor that specifically represses transcription of the tumor suppressor gene ARF, potentially leading indirectly to p53 inactivation. Our investigations on transcriptional repression of the p53 pathway revealed that FBI-1 represses transcription of ARF, Hdm2 (human analogue of mouse double minute oncogene), and p21CIP1 (hereafter indicated as p21) but not of p53. FBI-1 showed a more potent repressive effect on p21 than on p53. Our data suggested that FBI-1 is a master controller of the ARF-Hdm2-p53-p21 pathway, ultimately impinging on cell cycle arrest factor p21, by inhibiting upstream regulators at the transcriptional and protein levels. FBI-1 acted as a competitive transcriptional repressor of p53 and Sp1 and was shown to bind the proximal Sp1-3 GC-box and the distal p53-responsive elements of p21. Repression involved direct binding competition of FBI-1 with Sp1 and p53. FBI-1 also interacted with corepressors, such as mSin3A, NCoR, and SMRT, thereby deacetylating Ac-H3 and Ac-H4 histones at the promoter. FBI-1 caused cellular transformation, promoted cell cycle proliferation, and significantly increased the number of cells in S phase. FBI-1 is aberrantly overexpressed in many human solid tumors, particularly in adenocarcinomas and squamous carcinomas. The role of FBI-1 as a master controller of the p53 pathway therefore makes it an attractive therapeutic target.

  19. Proto-oncogene FBI-1 Represses Transcription of p21CIP1 by Inhibition of Transcription Activation by p53 and Sp1*S⃞

    PubMed Central

    Choi, Won-Il; Jeon, Bu-Nam; Yun, Chae-Ok; Kim, Pyung-Hwan; Kim, Sung-Eun; Choi, Kang-Yell; Kim, Se Hoon; Hur, Man-Wook

    2009-01-01

    Aberrant transcriptional repression through chromatin remodeling and histone deacetylation has been postulated as the driving force for tumorigenesis. FBI-1 (formerly called Pokemon) is a member of the POK family of transcriptional repressors. Recently, FBI-1 was characterized as a critical oncogenic factor that specifically represses transcription of the tumor suppressor gene ARF, potentially leading indirectly to p53 inactivation. Our investigations on transcriptional repression of the p53 pathway revealed that FBI-1 represses transcription of ARF, Hdm2 (human analogue of mouse double minute oncogene), and p21CIP1 (hereafter indicated as p21) but not of p53. FBI-1 showed a more potent repressive effect on p21 than on p53. Our data suggested that FBI-1 is a master controller of the ARF-Hdm2-p53-p21 pathway, ultimately impinging on cell cycle arrest factor p21, by inhibiting upstream regulators at the transcriptional and protein levels. FBI-1 acted as a competitive transcriptional repressor of p53 and Sp1 and was shown to bind the proximal Sp1–3 GC-box and the distal p53-responsive elements of p21. Repression involved direct binding competition of FBI-1 with Sp1 and p53. FBI-1 also interacted with corepressors, such as mSin3A, NCoR, and SMRT, thereby deacetylating Ac-H3 and Ac-H4 histones at the promoter. FBI-1 caused cellular transformation, promoted cell cycle proliferation, and significantly increased the number of cells in S phase. FBI-1 is aberrantly overexpressed in many human solid tumors, particularly in adenocarcinomas and squamous carcinomas. The role of FBI-1 as a master controller of the p53 pathway therefore makes it an attractive therapeutic target. PMID:19244234

  20. Vitamin D/Vitamin D Receptor Axis Regulates DNA Repair During Oncogene-Induced Senescence

    PubMed Central

    Graziano, Simona; Johnston, Rachel; Deng, Ou; Zhang, Junran; Gonzalo, Susana

    2016-01-01

    Oncogenic Ras expression is associated with activation of the DNA damage response (DDR) pathway, as evidenced by elevated DNA damage, primarily DNA double-strand breaks (DSBs), and activation of DNA damage checkpoints, which in primary human cells leads to entry into senescence. DDR activation is viewed as a physiological barrier against uncontrolled proliferation in oncogenic Ras-expressing cells, and arises in response to genotoxic stress due to the production of reactive oxygen species (ROS) that damage DNA, and to hyper-replication stress. Although oncogene-induced senescence (OIS) is considered a tumor suppressor mechanism, the accumulation of DNA damage in senescent cells is thought to cause genomic instability, eventually allowing secondary hits in the genome that promote tumorigenesis. To date, the molecular mechanisms behind DNA repair defects during OIS remain poorly understood. Here, we show that oncogenic Ras expression in human primary cells results in down-regulation of BRCA1 and 53BP1, two key factors in DNA DSBs repair by homologous recombination (HR) and non-homologous end joining (NHEJ), respectively. As a consequence, Ras-induced senescent cells are hindered in their ability to recruit BRCA1 and 53BP1 to DNA damage sites. While BRCA1 is down-regulated at transcripts levels, 53BP1 loss is caused by activation of cathepsin L (CTSL)-mediated degradation of 53BP1 protein. Moreover, we discovered a marked down-regulation of vitamin D receptor (VDR) during OIS, and a role for the vitamin D/VDR axis regulating the levels of these DNA repair factors during OIS. This study reveals a new functional relationship between the oncogene Ras, the vitamin D/VDR axis, and the expression of DNA repair factors, in the context of OIS. The observed deficiencies in DNA repair factors in senescent cells could contribute to the genomic instability that allows senescence bypass and tumorigenesis. PMID:27041576

  1. In utero exposure to second-hand smoke activates pro-asthmatic and oncogenic miRNAs in adult asthmatic mice.

    PubMed

    Xiao, Rui; Noël, Alexandra; Perveen, Zakia; Penn, Arthur L

    2016-04-01

    Exposures to environmental pollutants contribute to dysregulated microRNA (miRNA) expression profiles, which have been implicated in various diseases. Previously, we reported aggravated asthmatic responses in ovalbumin (OVA)-challenged adult mice that had been exposed in utero to second-hand smoke (SHS). Whether in utero SHS exposure dysregulates miRNA expression patterns in the adult asthma model has not been investigated. Pregnant BALB/c mice were exposed (days 6-19 of pregnancy) to SHS (10 mg/m(3)) or HEPA-filtered air. All offspring were sensitized and challenged with OVA (19-23 weeks) before sacrifice. RNA samples extracted from lung homogenates, were subjected to RNA sequencing (RNA-seq). RNA-seq identified nine miRNAs that were most significantly up-regulated by in utero SHS exposure. Among these nine, miR-155-5p, miR-21-3p, and miR-18a-5p were also highly correlated with pro-asthmatic Th2 cytokine levels in bronchoalveolar lavage fluid. Further analysis indicated that these up-regulated miRNAs shared common chromosome locations, particularly Chr 11C, with pro-asthmatic genes. These three miRNAs have also been characterized as oncogenic miRNAs (oncomirs). We cross-referenced miRNA-mRNA expression profiles and identified 16 tumor suppressor genes that were down-regulated in the in utero-exposed offspring and that are predicted targets of the up-regulated oncomirs. In conclusion, in utero SHS exposure activates pro-asthmatic genes and miRNAs, which colocalize at specific chromosome locations, in OVA-challenged adult mice. The oncogenic characteristics of the miRNAs and putative miRNA-mRNA regulatory networks suggest that the synergistic effect of in utero SHS exposure and certain adult irritants may promote an oncogenic milieu in mouse lungs via inhibition of miRNA-regulated tumor suppressor genes. PMID:26859758

  2. The HOX-5 and surfeit gene clusters are linked in the proximal portion of mouse chromosome 2.

    PubMed

    Stubbs, L; Huxley, C; Hogan, B; Evans, T; Fried, M; Duboule, D; Lehrach, H

    1990-04-01

    Using an interspecies backcross, we have mapped the HOX-5 and surfeit (surf) gene clusters within the proximal portion of mouse chromosome 2. While the HOX-5 cluster of homeobox-containing genes has been localized to chromosome 2, bands C3-E1, by in situ hybridization, its more precise position relative to the genes and cloned markers of chromosome 2 was not known. Surfeit, a tight cluster of at least six highly conserved "housekeeping" genes, has not been previously mapped in mouse, but has been localized to human chromosome 9q, a region of the human genome with strong homology to proximal mouse chromosome 2. The data presented here place HOX-5 in the vicinity of the closely linked set of developmental mutations rachiterata, lethargic, and fidget and place surf close to the proto-oncogene Abl, near the centromere of chromosome 2.

  3. Blocking c-myc and stat3 by E. coli expressed and enzyme digested siRNA in mouse melanoma

    SciTech Connect

    Hong Jie; Zhao Yingchun; Huang Weida . E-mail: whuang@fudan.edu.cn

    2006-09-22

    Tumour cells often show alteration in the signal-transduction pathways, leading to proliferation in response to external signals. Oncogene overexpression and constitutive expression is a common phenomenon in the development and progression of many human cancers. Therefore oncogenes provide potential targets for cancer therapy. RNA interference (RNAi), mediated by small interfering RNA (siRNA), silences genes with a high degree of specificity and potentially represents a general approach for molecularly targeted anti-cancer therapy. The data presented in this report evaluated the method of systemically administering combined esiRNAs to multiple targets as compared with the method of using a single kind of esiRNA to a single target. Our experimental data revealed that the mixed treatment of esiC-MYC and esiSTAT3 had a better inhibition effect than the single treatment of esiC-MYC or esiSTAT3 on mouse B16 melanoma.

  4. Targeting the production of oncogenic microRNAs with multimodal synthetic small molecules.

    PubMed

    Vo, Duc Duy; Staedel, Cathy; Zehnacker, Laura; Benhida, Rachid; Darfeuille, Fabien; Duca, Maria

    2014-03-21

    MicroRNAs (miRNAs) are a recently discovered category of small RNA molecules that regulate gene expression at the post-transcriptional level. Accumulating evidence indicates that miRNAs are aberrantly expressed in a variety of human cancers and revealed to be oncogenic and to play a pivotal role in initiation and progression of these pathologies. It is now clear that the inhibition of oncogenic miRNAs, defined as blocking their biosynthesis or their function, could find an application in the therapy of different types of cancer in which these miRNAs are implicated. Here we report the design, synthesis, and biological evaluation of new small-molecule RNA ligands targeting the production of oncogenic microRNAs. In this work we focused our attention on miR-372 and miR-373 that are implicated in the tumorigenesis of different types of cancer such as gastric cancer. These two oncogenic miRNAs are overexpressed in gastric cancer cells starting from their precursors pre-miR-372 and pre-miR-373, two stem-loop structured RNAs that lead to mature miRNAs after cleavage by the enzyme Dicer. The small molecules described herein consist of the conjugation of two RNA binding motives, i.e., the aminoglycoside neomycin and different natural and artificial nucleobases, in order to obtain RNA ligands with increased affinity and selectivity compared to that of parent compounds. After the synthesis of this new series of RNA ligands, we demonstrated that they are able to inhibit the production of the oncogenic miRNA-372 and -373 by binding their pre-miRNAs and inhibiting the processing by Dicer. Moreover, we proved that some of these compounds bear anti-proliferative activity toward gastric cancer cells and that this activity is likely linked to a decrease in the production of targeted miRNAs. To date, only few examples of small molecules targeting oncogenic miRNAs have been reported, and such inhibitors could be extremely useful for the development of new anticancer therapeutic

  5. Mouse bladder wall injection.

    PubMed

    Fu, Chi-Ling; Apelo, Charity A; Torres, Baldemar; Thai, Kim H; Hsieh, Michael H

    2011-07-12

    Mouse bladder wall injection is a useful technique to orthotopically study bladder phenomena, including stem cell, smooth muscle, and cancer biology. Before starting injections, the surgical area must be cleaned with soap and water and antiseptic solution. Surgical equipment must be sterilized before use and between each animal. Each mouse is placed under inhaled isoflurane anesthesia (2-5% for induction, 1-3% for maintenance) and its bladder exposed by making a midline abdominal incision with scissors. If the bladder is full, it is partially decompressed by gentle squeezing between two fingers. The cell suspension of interest is intramurally injected into the wall of the bladder dome using a 29 or 30 gauge needle and 1 cc or smaller syringe. The wound is then closed using wound clips and the mouse allowed to recover on a warming pad. Bladder wall injection is a delicate microsurgical technique that can be mastered with practice.

  6. Cell type-specific targeted mutations of Kras and Pten document proliferation arrest in granulosa cells versus oncogenic insult to ovarian surface epithelial cells.

    PubMed

    Fan, Heng-Yu; Liu, Zhilin; Paquet, Marilene; Wang, Jinrong; Lydon, John P; DeMayo, Francesco J; Richards, JoAnne S

    2009-08-15

    The small G-protein KRAS is crucial for mediating gonadotropin-induced events associated with ovulation. However, constitutive expression of KrasG12D in granulosa cells disrupted normal follicle development leading to the persistence of abnormal follicle-like structures containing nonmitotic cells. To determine what factors mediate this potent effect of KrasG12D, gene profiling analyses were done. We also analyzed KrasG12D;Cyp19-Cre and KrasG12;Pgr-Cre mutant mouse models that express Cre prior to or after the initiation of granulosa cell differentiation, respectively. KrasG12D induced cell cycle arrest in granulosa cells of the KrasG12D;Cyp19-Cre mice but not in the KrasG12D;Pgr-Cre mice, documenting the cell context-specific effect of KrasG12D. Expression of KrasG12D silenced the Kras gene, reduced cell cycle activator genes, and impaired the expression of granulosa cell and oocyte-specific genes. Conversely, levels of PTEN and phosphorylated p38 mitogen-activated protein kinase (MAPK) increased markedly in the mutant granulosa cells. Because disrupting Pten in granulosa cells leads to increased proliferation and survival, Pten was disrupted in the KrasG12D mutant mice. The Pten/Kras mutant mice were infertile but lacked granulosa cell tumors. By contrast, the Ptenfl/fl;KrasG12D;Amhr2-Cre mice developed aggressive ovarian surface epithelial cell tumors that did not occur in the Ptenfl/fl;KrasG12D;Cyp19-Cre or Ptenfl/fl;KrasG12D;Pgr-Cre mouse strains. These data document unequivocally that Amhr2-Cre is expressed in and mediates allelic recombination of oncogenic genes in ovarian surface epithelial cells. That KrasG12D/Pten mutant granulosa cells do not transform but rather undergo cell cycle arrest indicates that they resist the oncogenic insults of Kras/Pten by robust self-protecting mechanisms that silence the Kras gene and elevate PTEN and phosphorylated p38 MAPK.

  7. Distinct Malignant Behaviors of Mouse Myogenic Tumors Induced by Different Oncogenetic Lesions

    PubMed Central

    Hettmer, Simone; Bronson, Roderick T.; Wagers, Amy J.

    2015-01-01

    Rhabdomyosarcomas (RMS) are heterogeneous cancers with myogenic differentiation features. The cytogenetic and mutational aberrations in RMS are diverse. This study examined differences in the malignant behavior of two genetically distinct and disease-relevant mouse myogenic tumor models. Kras; p1619null myogenic tumors, initiated by expression of oncogenic Kras in p16p19null mouse satellite cells, were metastatic to the lungs of the majority of tumor-bearing animals and repopulated tumors in seven of nine secondary recipients. In contrast, SmoM2 tumors, initiated by ubiquitous expression of a mutant Smoothened allele, did not metastasize and repopulated tumors in 2 of 18 recipients only. In summary, genetically distinct myogenic tumors in mice exhibit marked differences in malignant behavior. PMID:25759794

  8. Hydrodynamic Transfection for Generation of Novel Mouse Models for Liver Cancer Research

    PubMed Central

    Chen, Xin; Calvisi, Diego F.

    2015-01-01

    Primary liver cancers, including hepatocellular carcinoma and intrahepatic cholangiocarcinoma, are leading causes of cancer-related death worldwide. Recent large-scale genomic approaches have identified a wide number of genes whose deregulation is associated with hepatocellular carcinoma and intrahepatic cholangiocarcinoma development. Murine models are critical tools to determine the oncogenic potential of these genes. Conventionally, transgenic or knockout mouse models are used for this purpose. However, several limitations apply to the latter models. Herein, we review a novel approach for stable gene expression in mouse hepatocytes by hydrodynamic injection in combination with Sleeping Beauty–mediated somatic integration. This method represents a flexible, reliable, and cost-effective tool to generate preclinical murine models for liver cancer research. Furthermore, it can be used as an in vivo transfection method to study biochemical cross talks among multiple pathways along hepatocarcinogenesis and to test the therapeutic potential of drugs against liver cancer. PMID:24480331

  9. Mouse models of human non-small-cell lung cancer: raising the bar.

    PubMed

    Kim, C F B; Jackson, E L; Kirsch, D G; Grimm, J; Shaw, A T; Lane, K; Kissil, J; Olive, K P; Sweet-Cordero, A; Weissleder, R; Jacks, T

    2005-01-01

    Lung cancer is a devastating disease that presents a challenge to basic research to provide new steps toward therapeutic advances. The cell-type-specific responses to oncogenic mutations that initiate and regulate lung cancer remain poorly defined. A better understanding of the relevant signaling pathways and mechanisms that control therapeutic outcome could also provide new insight. Improved conditional mouse models are now available as tools to improve the understanding of the cellular and molecular origins of adenocarcinoma. These models have already proven their utility in proof-of-principle experiments with new technologies including genomics and imaging. Integrated thinking to apply technological advances while using the appropriate mouse model is likely to facilitate discoveries that will significantly improve lung cancer detection and intervention.

  10. miR-203 suppresses the proliferation and metastasis of hepatocellular carcinoma by targeting oncogene ADAM9 and oncogenic long non-coding RNA HULC.

    PubMed

    Wan, Daiwei; Shen, Shunli; Fu, Shunjun; Preston, Burnley; Brandon, Coder; He, Songbing; Shen, Chenglong; Wu, Jian; Wang, Sutong; Xie, Wenxuan; Chen, Bin; Liya, A; Guo, Yixing; Zheng, Dingcheng; Zhi, Qiaoming; Peng, Baogang

    2016-01-01

    MicroRNAs (miRNAs) have been integrated into tumorigenic programs by regulating genes at post-transcriptional level. Long non-coding RNAs (lncRNAs) are novel targets for miRNAs. Here, we reported that miR-203 down-regulation was closely linked to advanced clinical features and poor overall survival (OS) of patients with hepatocellular carcinoma. We also confirmed that miR-203 and oncogene ADAM9 (a disintegrin and metalloproteinase 9)/oncogenic long non-coding RNA HULC (highly up-regulated in liver cancer) were inversely expressed in hepatocellular carcinoma (HCC) tissues or cell lines. More intriguingly, up-regulation of miR-203 diminished the expression of ADAM9 and HULC in HCC cancer cells. Over-expression of miR-203 could markedly inhibit cell proliferation, invasion and induce cell apoptosis. Furthermore, we identified that miR-203 modulated ADAM9 and HULC in a novel post-transcriptional regulatory mechanism. Over-expression of HULC partly rescued the miR-203-mediated antitumor effects. These results suggested that miR-203 played tumor suppressive roles by downregulating ADAM9 and HULC and indicated its potential application in cancer treatment.

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

    PubMed

    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.

  12. RNA-DNA differences are rarer in proto-oncogenes than in tumor suppressor genes.

    PubMed

    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.

  13. WISP-1 is a Wnt-1- and beta-catenin-responsive oncogene.

    PubMed

    Xu, L; Corcoran, R B; Welsh, J W; Pennica, D; Levine, A J

    2000-03-01

    WISP-1 (Wnt-1 induced secreted protein 1) is a member of the CCN family of growth factors. This study identifies WISP-1 as a beta-catenin-regulated gene that can contribute to tumorigenesis. The promoter of WISP-1 was cloned and shown to be activated by both Wnt-1 and beta-catenin expression. TCF/LEF sites played a minor role, whereas the CREB site played an important role in this transcriptional activation. WISP-1 demonstrated oncogenic activities; overexpression of WISP-1 in normal rat kidney fibroblast cells (NRK-49F) induced morphological transformation, accelerated cell growth, and enhanced saturation density. Although these cells did not acquire anchorage-independent growth in soft agar, they readily formed tumors in nude mice, suggesting that appropriate cellular attachment is important for signaling oncogenic events downstream of WISP-1.

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

    PubMed

    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.

  15. Mitochondrial Ca2+ Remodeling is a Prime Factor in Oncogenic Behavior

    PubMed Central

    Rimessi, Alessandro; Patergnani, Simone; Bonora, Massimo; Wieckowski, Mariusz R.; Pinton, Paolo

    2015-01-01

    Cancer is sustained by defects in the mechanisms underlying cell proliferation, mitochondrial metabolism, and cell death. Mitochondrial Ca2+ ions are central to all these processes, serving as signaling molecules with specific spatial localization, magnitude, and temporal characteristics. Mutations in mtDNA, aberrant expression and/or regulation of Ca2+-handling/transport proteins and abnormal Ca2+-dependent relationships among the cytosol, endoplasmic reticulum, and mitochondria can cause the deregulation of mitochondrial Ca2+-dependent pathways that are related to these processes, thus determining oncogenic behavior. In this review, we propose that mitochondrial Ca2+ remodeling plays a pivotal role in shaping the oncogenic signaling cascade, which is a required step for cancer formation and maintenance. We will describe recent studies that highlight the importance of mitochondria in inducing pivotal “cancer hallmarks” and discuss possible tools to manipulate mitochondrial Ca2+ to modulate cancer survival. PMID:26161362

  16. Small-Molecule Protein-Protein Interaction Inhibitor of Oncogenic Rho Signaling.

    PubMed

    Diviani, Dario; Raimondi, Francesco; Del Vescovo, Cosmo D; Dreyer, Elisa; Reggi, Erica; Osman, Halima; Ruggieri, Lucia; Gonano, Cynthia; Cavin, Sabrina; Box, Clare L; Lenoir, Marc; Overduin, Michael; Bellucci, Luca; Seeber, Michele; Fanelli, Francesca

    2016-09-22

    Uncontrolled activation of Rho signaling by RhoGEFs, in particular AKAP13 (Lbc) and its close homologs, is implicated in a number of human tumors with poor prognosis and resistance to therapy. Structure predictions and alanine scanning mutagenesis of Lbc identified a circumscribed hot region for RhoA recognition and activation. Virtual screening targeting that region led to the discovery of an inhibitor of Lbc-RhoA interaction inside cells. By interacting with the DH domain, the compound inhibits the catalytic activity of Lbc, halts cellular responses to activation of oncogenic Lbc pathways, and reverses a number of prostate cancer cell phenotypes such as proliferation, migration, and invasiveness. This study provides insights into the structural determinants of Lbc-RhoA recognition. This is a successful example of structure-based discovery of a small protein-protein interaction inhibitor able to halt oncogenic Rho signaling in cancer cells with therapeutic implications.

  17. Repurposing a Prokaryotic Toxin-Antitoxin System for the Selective Killing of Oncogenically Stressed Human Cells.

    PubMed

    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.

  18. Oncogenic MITF dysregulation in clear cell sarcoma: defining the MiT family of human cancers.

    PubMed

    Davis, Ian J; Kim, Jessica J; Ozsolak, Fatih; Widlund, Hans R; Rozenblatt-Rosen, Orit; Granter, Scott R; Du, Jinyan; Fletcher, Jonathan A; Denny, Christopher T; Lessnick, Stephen L; Linehan, W Marston; Kung, Andrew L; Fisher, David E

    2006-06-01

    Clear cell sarcoma (CCS) harbors a pathognomonic chromosomal translocation fusing the Ewing's sarcoma gene (EWS) to the CREB family transcription factor ATF1 and exhibits melanocytic features. We show that EWS-ATF1 occupies the MITF promoter, mimicking melanocyte-stimulating hormone (MSH) signaling to induce expression of MITF, the melanocytic master transcription factor and an amplified oncogene in melanoma. Knockdown/rescue studies revealed that MITF mediates the requirement of EWS-ATF1 for CCS survival in vitro and in vivo as well as for melanocytic differentiation. Moreover, MITF and TFE3 reciprocally rescue one another in lines derived from CCS or pediatric renal carcinoma. Seemingly unrelated tumors thus employ distinct strategies to oncogenically dysregulate the MiT family, collectively broadening the definition of MiT-associated human cancers.

  19. Tumor suppression by miR-26 overrides potential oncogenic activity in intestinal tumorigenesis

    PubMed Central

    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

  20. The MET Oncogene as a Therapeutical Target in Cancer Invasive Growth

    PubMed Central

    Luraghi, Paolo; Schelter, Florian; Krüger, Achim; Boccaccio, Carla

    2012-01-01

    The MET proto-oncogene, encoding the tyrosine kinase receptor for Hepatocyte Growth Factor (HGF) regulates invasive growth, a genetic program that associates control of cell proliferation with invasion of the extracellular matrix and protection from apoptosis. Physiologically, invasive growth takes place during embryonic development, and, in post-natal life, in wound healing and regeneration of several tissues. The MET oncogene is overexpressed and/or genetically mutated in many tumors, thereby sustaining pathological invasive growth, a prerequisite for metastasis. MET is the subject of intense research as a target for small molecule kinase inhibitors and, together with its ligand HGF, for inhibitory antibodies. The tight interplay of MET with the protease network has unveiled mechanisms to be exploited to achieve effective inhibition of invasive growth. PMID:22973229

  1. An oncogenic MYB feedback loop drives alternate cell fates in adenoid cystic carcinoma

    PubMed Central

    Drier, Yotam; Cotton, Matthew J.; Williamson, Kaylyn E.; Gillespie, Shawn M.; Ryan, Russell J.H.; Kluk, Michael J.; Carey, Christopher D.; Rodig, Scott J.; Sholl, Lynette M; Afrogheh, Amir H.; Faquin, William C.; Queimado, Lurdes; Qi, Jun; Wick, Michael J.; El-Naggar, Adel K.; Bradner, James E.; Moskaluk, Christopher A.; Aster, Jon C.; Knoechel, Birgit; Bernstein, Bradley E.

    2016-01-01

    Translocation events are frequent in cancer and may create chimeric fusions or ‘regulatory rearrangements’ that drive oncogene overexpression. Here we identify super-enhancer translocations that drive overexpression of the oncogenic transcription factor MYB as a recurrent theme in adenoid cystic carcinoma (ACC). Whole-genome sequencing data and chromatin maps reveal distinct chromosomal rearrangements that juxtapose super-enhancers to the MYB locus. Chromosome conformation capture confirms that the translocated enhancers interact with the MYB promoter. Remarkably, MYB protein binds to the translocated enhancers, creating a positive feedback loop that sustains its expression. MYB also binds enhancers that drive different regulatory programs in alternate cell lineages in ACC, cooperating with TP63 in myoepithelial cells and a Notch program in luminal epithelial cells. Bromodomain inhibitors slow tumor growth in ACC primagraft models in vivo. Thus, our study identifies super-enhancer translocations that drive MYB expression and provides insight into downstream MYB functions in the alternate ACC lineages. PMID:26829750

  2. Centrosomal targeting of tyrosine kinase activity does not enhance oncogenicity in chronic myeloproliferative disorders.

    PubMed

    Bochtler, T; Kirsch, M; Maier, B; Bachmann, J; Klingmüller, U; Anderhub, S; Ho, A D; Krämer, A

    2012-04-01

    Constitutive tyrosine kinase activation by reciprocal chromosomal translocation is a common pathogenetic mechanism in chronic myeloproliferative disorders. Since centrosomal proteins have been recurrently identified as translocation partners of tyrosine kinases FGFR1, JAK2, PDGFRα and PDGFRβ in these diseases, a role for the centrosome in oncogenic transformation has been hypothesized. In this study, we addressed the functional role of centrosomally targeted tyrosine kinase activity. First, centrosomal localization was not routinely found for all chimeric fusion proteins tested. Second, targeting of tyrosine kinases to the centrosome by creating artificial chimeric fusion kinases with the centrosomal targeting domain of AKAP450 failed to enhance the oncogenic transforming potential in both Ba/F3 and U2OS cells, although phospho-tyrosine-mediated signal transduction pathways were initiated at the centrosome. We conclude that the centrosomal localization of constitutively activated tyrosine kinases does not contribute to disease pathogenesis in chronic myeloproliferative disorders. PMID:22015771

  3. KRAS2 oncogene overexpression in myelodysplastic syndrome with translocation 5;12.

    PubMed

    Srivastava, A; Boswell, H S; Heerema, N A; Nahreini, P; Lauer, R C; Antony, A C; Hoffman, R; Tricot, G J

    1988-10-01

    The factors that initiate and maintain the abnormal hematopoietic clone in the myelo-dysplastic syndromes (MDS) remain largely unknown. We describe a patient with MDS associated with an abnormal karyotype, 46,XY,t(5;12)(q31;p12). According to the FAB cooperative group classification, the patient was classified as chronic myelomonocytic leukemia. Because of the particular chromosomal translocation, the structure-function relationship of three genes relevant to the translocation breakpoints, CSF2, FMS, and KRAS2, was studied in bone marrow and peripheral blood lymphocytes in this patient. No major structural alterations were observed at these three genetic loci. Although the levels of expression of the CSF2 and FMS genes remained unaltered, the KRAS2 oncogene was overexpressed approximately six-fold in bone marrow cells from the MDS patient compared with normal donors. We postulate that the RAS oncogene activation may be instrumental in the genesis of MDS.

  4. Initiation of oncogenic transformation in human mammary epithelial cells by charged particles

    NASA Technical Reports Server (NTRS)

    Yang, T. C.; Georgy, K. A.; Craise, L. M.; Durante, M.

    1997-01-01

    Experimental studies have shown that high linear-energy transfer (LET) charged particles can be more effective than x-rays and gamma-rays in inducing oncogenic transformation in cultured cells and tumors in animals. Based on these results, experiments were designed and performed with an immortal human mammary epithelial cell line (H184B5), and several clones transformed by heavy ions were obtained. Cell fusion experiments were subsequently done, and results indicate that the transforming gene(s) is recessive. Chromosome analysis with fluorescence in situ hybridization (FISH) techniques also showed additional translocations in transformed human mammary epithelial cells. In addition, studies with these cell lines indicate that heavy ions can effectively induce deletion, break, and dicentrics. Deletion of tumor suppressor gene(s) and/or formation of translocation through DNA double strand breaks is a likely mechanism for the initiation of oncogenic transformation in human mammary epithelial cells.

  5. NSD3-NUT Fusion Oncoprotein in NUT Midline Carcinoma: Implications for a Novel Oncogenic Mechanism

    PubMed Central

    French, Christopher A.; Rahman, Shaila; Walsh, Erica M.; Kühnle, Simone; Grayson, Adlai R.; Lemieux, Madeleine E.; Grunfeld, Noam; Rubin, Brian P.; Antonescu, Cristina R.; Zhang, Songlin; Venkatramani, Rajkumar; Cin, Paola Dal; Howley, Peter M.

    2014-01-01

    NUT midline carcinoma (NMC) is an aggressive subtype of squamous cell carcinoma that typically harbors BRD4/3-NUT fusion oncoproteins that block differentiation and maintain tumor growth. In 20% of cases NUT is fused to uncharacterized non-BRD gene(s). We established a new patient-derived NMC cell line (1221) and demonstrated that it harbors a novel NSD3-NUT fusion oncogene. We find that NSD3-NUT is both necessary and sufficient for the blockade of differentiation and maintenance of proliferation in NMC cells. NSD3-NUT binds to BRD4, and BRD bromodomain inhibitors induce differentiation and arrest proliferation of 1221 cells. We find further that NSD3 is required for the blockade of differentiation in BRD4-NUT-expressing NMCs. These findings identify NSD3 as a novel critical oncogenic component and potential therapeutic target in NMC. PMID:24875858

  6. A human oncogene of the RAS superfamily unmasked by expression cDNA cloning.

    PubMed Central

    Chan, A M; Miki, T; Meyers, K A; Aaronson, S A

    1994-01-01

    As an approach to identify human oncogenes, we generated an expression cDNA library from an ovarian carcinoma line. A potent transforming gene was detected by transfection analysis and identified as TC21, a recently cloned member of the RAS gene superfamily. A single point mutation substituting glutamine for leucine at position 72 was shown to be responsible for activation of transforming properties. While the cDNA clone possessed high transforming activity, the ovarian tumor genomic DNA, which contained the mutated TC21 allele, failed to induce transformed foci. Thus, expression cDNA cloning made it possible to identify and isolate a human oncogene that has evaded detection by conventional approaches. Images PMID:8052619

  7. Wnt/β-catenin, an oncogenic pathway targeted by H. pylori in gastric carcinogenesis.

    PubMed

    Song, Xiaowen; Xin, Na; Wang, Wei; Zhao, Chenghai

    2015-11-01

    A section of gastric cancers presents nuclear β-catenin accumulation correlated with H. pylori infection. H. pylori stimulate Wnt/β-catenin pathway by activating oncogenic c-Met and epidermal growth factor receptor (EGFR), or by inhibiting tumor suppressor Runx3 and Trefoil factor 1 (TFF1). H. pylori also trigger Wnt/β-catenin pathway by recruiting macrophages. Moreover, Wnt/β-catenin pathway is found involved in H. pylori-induced gastric cancer stem cell generation. Recently, by using gastroids, researchers have further revealed that H. pylori induce gastric epithelial cell proliferation through β-catenin. These findings indicate that Wnt/β-catenin is an oncogenic pathway activated by H. pylori. Therefore, this pathway is a potential therapy target for H. pylori-related gastric cancer. PMID:26417932

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

    SciTech Connect

    Ebert, R.; Reiss, E.; Roellich, G.; Schiffmann, D. ); Barrett, J.C.; Wiseman, R.W. ); 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.

  9. Cellular senescence checkpoint function determines differential Notch1-dependent oncogenic and tumor suppressor activities

    PubMed Central

    Kagawa, Shingo; Natsuizaka, Mitsuteru; Whelan, Kelly A.; Facompre, Nicole; Naganuma, Seiji; Ohashi, Shinya; Kinugasa, Hideaki; Egloff, Ann Marie; Basu, Devraj; Gimotty, Phyllis A.; Klein-Szanto, Andres J; Bass, Adam; Wong, Kwok-Kin; Diehl, J. Alan; Rustgi, Anil K.; Nakagawa, Hiroshi

    2014-01-01

    Notch activity regulates tumor biology in a context-dependent and complex manner. Notch may act as an oncogene or a tumor suppressor gene even within the same tumor type. Recently, Notch signaling has been implicated in cellular senescence. Yet, it remains unclear as to how cellular senescence checkpoint functions may interact with Notch-mediated oncogenic and tumor suppressor activities. Herein, we used genetically engineered human esophageal keratinocytes and esophageal squamous cell carcinoma cells to delineate the functional consequences of Notch activation and inhibition along with pharmacological intervention and RNA interference (RNAi) experiments. When expressed in a tetracycline-inducible manner, the ectopically expressed activated form of Notch1 (ICN1) displayed oncogene-like characteristics inducing cellular senescence corroborated by the induction of G0/G1 cell-cycle arrest, Rb dephosphorylation, flat and enlarged cell morphology and senescence-associated β-galactosidase activity. Notch-induced senescence involves canonical CSL/RBPJ-dependent transcriptional activity and the p16INK4A-Rb pathway. Loss of p16INK4A or the presence of human papilloma virus (HPV) E6/E7 oncogene products not only prevented ICN1 from inducing senescence, but permitted ICN1 to facilitate anchorage-independent colony formation and xenograft tumor growth with increased cell proliferation and reduced squamous-cell differentiation. Moreover, Notch1 appears to mediate replicative senescence as well as TGF-β-induced cellular senescence in non-transformed cells and that HPV E6/E7 targets Notch1 for inactivation to prevent senescence, revealing a tumor suppressor attribute of endogenous Notch1. In aggregate, cellular senescence checkpoint functions may influence dichotomous Notch activities in the neoplastic context. PMID:24931169

  10. The Oncogenic Transforming Potential of the Passage of Single α Particles through Mammalian Cell Nuclei

    NASA Astrophysics Data System (ADS)

    Miller, Richard C.; Randers-Pehrson, Gerhard; Geard, Charles R.; Hall, Eric J.; Brenner, David J.

    1999-01-01

    Domestic, low-level exposure to radon gas is considered a major environmental lung-cancer hazard involving DNA damage to bronchial cells by α particles from radon progeny. At domestic exposure levels, the relevant bronchial cells are very rarely traversed by more than one α particle, whereas at higher radon levels--at which epidemiological studies in uranium miners allow lung-cancer risks to be quantified with reasonable precision--these bronchial cells are frequently exposed to multiple α -particle traversals. Measuring the oncogenic transforming effects of exactly one α particle without the confounding effects of multiple traversals has hitherto been unfeasible, resulting in uncertainty in extrapolations of risk from high to domestic radon levels. A technique to assess the effects of single α particles uses a charged-particle microbeam, which irradiates individual cells or cell nuclei with predefined exact numbers of particles. Although previously too slow to assess the relevant small oncogenic risks, recent improvements in throughput now permit microbeam irradiation of large cell numbers, allowing the first oncogenic risk measurements for the traversal of exactly one α particle through a cell nucleus. Given positive controls to ensure that the dosimetry and biological controls were comparable, the measured oncogenicity from exactly one α particle was significantly lower than for a Poisson-distributed mean of one α particle, implying that cells traversed by multiple α particles contribute most of the risk. If this result applies generally, extrapolation from high-level radon risks (involving cellular traversal by multiple α particles) may overestimate low-level (involving only single α particles) radon risks.

  11. Expression of proto-oncogenes and gene mutation of sarcomeric proteins in patients with hypertrophic cardiomyopathy.

    PubMed

    Kai, H; Muraishi, A; Sugiu, Y; Nishi, H; Seki, Y; Kuwahara, F; Kimura, A; Kato, H; Imaizumi, T

    1998-09-21

    Several mutations of cardiac beta-myosin heavy chain (beta-MHC) gene were reported in patients with hypertrophic cardiomyopathy (HCM). Involvement of proto-oncogenes has been shown in the mechanism of experimental cardiac hypertrophy. This study sought to examine the effects of c-H-ras and c-myc expression in the steady-state myocardium on hypertrophic changes and to evaluate the possible interaction between beta-MHC mutation and proto-oncogene expression in HCM. Endomyocardial biopsy was performed in 17 HCM patients (5 beta-MHC mutations and 1 troponin T mutation) and 7 control subjects (no mutation). Reverse transcription-polymerase chain reaction analysis revealed c-H-ras expression in all members of both groups. Cardiomyocyte size was correlated with the expression level of c-H-ras (P<0.001), and c-H-ras expression was upregulated in HCM patients (P<0.01). HCM patients with a beta-MHC mutation had the higher c-H-ras expression than did control subjects or patients without a mutation (P<0.01). c-myc mRNA was expressed in 7 of 17 HCM patients but not in control subjects. Myocyte size was greater in c-myc-positive HCM patients than in control subjects and c-myc-negative HCM patients (P<0.001 and P<0.05, respectively). The proto-oncogene expression did not affect clinical findings, myocardial fibrosis, or disarray. In conclusion, c-H-ras and c-myc expression in the steady-state myocardium may play a role in the hypertrophic mechanism in HCM. It is possible that ss-MHC gene mutation has some effect on the regulation of proto-oncogene expression in HCM.

  12. The Activating Transcription Factor 3 Protein Suppresses the Oncogenic Function of Mutant p53 Proteins*

    PubMed Central

    Wei, Saisai; Wang, Hongbo; Lu, Chunwan; Malmut, Sarah; Zhang, Jianqiao; Ren, Shumei; Yu, Guohua; Wang, Wei; Tang, Dale D.; Yan, Chunhong

    2014-01-01

    Mutant p53 proteins (mutp53) often acquire oncogenic activities, conferring drug resistance and/or promoting cancer cell migration and invasion. Although it has been well established that such a gain of function is mainly achieved through interaction with transcriptional regulators, thereby modulating cancer-associated gene expression, how the mutp53 function is regulated remains elusive. Here we report that activating transcription factor 3 (ATF3) bound common mutp53 (e.g. R175H and R273H) and, subsequently, suppressed their oncogenic activities. ATF3 repressed mutp53-induced NFKB2 expression and sensitized R175H-expressing cancer cells to cisplatin and etoposide treatments. Moreover, ATF3 appeared to suppress R175H- and R273H-mediated cancer cell migration and invasion as a consequence of preventing the transcription factor p63 from inactivation by mutp53. Accordingly, ATF3 promoted the expression of the metastasis suppressor SHARP1 in mutp53-expressing cells. An ATF3 mutant devoid of the mutp53-binding domain failed to disrupt the mutp53-p63 binding and, thus, lost the activity to suppress mutp53-mediated migration, suggesting that ATF3 binds to mutp53 to suppress its oncogenic function. In line with these results, we found that down-regulation of ATF3 expression correlated with lymph node metastasis in TP53-mutated human lung cancer. We conclude that ATF3 can suppress mutp53 oncogenic function, thereby contributing to tumor suppression in TP53-mutated cancer. PMID:24554706

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

    SciTech Connect

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. Mate choice for more melanin as a mechanism to maintain a functional oncogene

    PubMed Central

    Fernandez, André A.; Morris, Molly R.

    2008-01-01

    The mechanisms by which cancer evolves and persists in natural systems have been difficult to ascertain. In the Xiphophorus melanoma model, a functional oncogene (Xiphophorus melanoma receptor kinase Xmrk) has been maintained for several million years despite being deleterious and in an extremely unstable genomic region. Melanomas in Xiphophorus spp. fishes (platyfishes and swordtails) have been investigated since the 1920s, and, yet, positive selection that could explain the maintenance of Xmrk has not been found. Here, we show that Xiphophorus cortezi females from two populations prefer males with the spotted caudal (Sc) melanin pattern, which is associated with the presence of the Xmrk oncogene and serves as the site of melanoma formation within this species. Moreover, X. cortezi females prefer males with an enhanced Sc to males with a reduced Sc pattern. RT-PCR analysis confirms tissue-specific Xmrk expression within the Sc pattern in X. cortezi. Because of the association of Xmrk with the Sc pigment pattern and the fact that melanoma formation augments this visual signal, sexual selection appears to be maintaining this oncogene because of a mating preference for Sc, as well as the exaggeration of this male trait. At the individual level, decreases in viability and fecundity because of Xmrk and subsequent melanoma formation may be mitigated via increases in mate acquisition. At the population level, maintenance of this oncogene appears to be under frequency dependent selection, as we detected female preference for males without Sc in a third population that had higher frequencies of Sc in females. PMID:18757731

  16. Biological basis of personalized anticoagulation in cancer: oncogene and oncomir networks as putative regulators of coagulopathy.

    PubMed

    D'Asti, Esterina; Rak, Janusz

    2016-04-01

    Activation of stromal response pathways in cancer is increasingly viewed as both a local and systemic extension of molecular alterations driving malignant transformation. Rather than reflecting passive and unspecific responses to anatomical abnormalities, the coagulation system is a target of oncogenic deregulation, impacting the role of clotting and fibrinolytic proteins, and integrating hemostasis, inflammation, angiogenesis and cellular growth effects in cancer. These processes signify, but do not depend on, the clinically manifest coagulopathy and thrombosis. In this regard, the role of driver mutations affecting oncoprotein coding genes such as RAS, EGFR or MET and tumour suppressors (PTEN, TP53) are well described as regulators of tissue factor (TF), protease activated receptors (PAR-1/2) and ectopic coagulation factors (FVII). Indeed, in both adult and pediatric brain tumours the expression patterns of coagulation and angiogenesis regulators (coagulome and angiome, respectively) reflect the molecular subtypes of the underlying diseases (glioblastoma or medulloblastoma) as defined by their oncogenic classifiers and clinical course. This emerging understanding is still poorly established in relation to the transforming effects of non-coding genes, including those responsible for the expression of microRNA (miR). Indeed, several miRs have been recently found to regulate TF and other effectors. We recently documented that in the context of the aggressive embryonal tumour with multilayered rosettes (ETMR) the oncogenic driver miR (miR-520g) suppresses the expression of TF and correlates with hypocoagulant tumour characteristics. Unlike in adult cancers, the growth of pediatric embryonal brain tumour cells as spheres (to maintain stem cell properties) results in upregulation of miR-520g and downregulation of TF expression and activity. We postulate that oncogenic protein and miR coding genes form alternative pathways of coagulation system regulation in different

  17. Expression of c-yes oncogene product in various animal tissues and spontaneous canine tumours.

    PubMed

    Rungsipipat, A; Tateyama, S; Yamaguchi, R; Uchida, K; Miyoshi, N

    1999-06-01

    An immunohistochemical study of various visceral organs of normal adult dogs, cats, pigs, horses, cows, and chickens (five of each species) and of 185 spontaneous canine tumours was carried out using paraffin wax sections and a commercially available antibody to the human c- yes oncogene product. Among the adult normal tissues of six animal species, epithelial cells of the proximal and distal renal tubules, the myocardium, hepatocytes, cerebellar Purkinje cells and adrenal cortical cells were positive for c- yes product. Among the foetal tissues of dogs and chickens, a positive reaction was observed on canine chorionic villi cells and chick yolk sac surface epithelium, and on epithelial cells of the renal tubules, hepatocytes and the myocardium. These findings suggest that the c- yes proto-oncogene may play a physiological role in the cell growth and metabolism of these adult and foetal tissues. Of the 185 tumours tested, 59 (31.9 per cent) expressed the c- yes oncogene product. The c- yes -positive tumours accounted for 44.4 per cent (12/27) of the skin tumours, 5.5 per cent (1/18) of the round cell tumours, 35. 7 per cent (10/28) of the soft tissue tumours, 21.4 per cent (3/14) of the testicular tumours, 29.1 per cent (23/79) of the mammary tumours, and 52.6 per cent (10/19) of the other tumours types. Expression of the c- yes oncogene appeared to be common in spontaneously arising canine tumours, and the degree of expression varied considerably by tumour type.

  18. Cellular senescence checkpoint function determines differential Notch1-dependent oncogenic and tumor-suppressor activities.

    PubMed

    Kagawa, S; Natsuizaka, M; Whelan, K A; Facompre, N; Naganuma, S; Ohashi, S; Kinugasa, H; Egloff, A M; Basu, D; Gimotty, P A; Klein-Szanto, A J; Bass, A J; Wong, K-K; Diehl, J A; Rustgi, A K; Nakagawa, H

    2015-04-30

    Notch activity regulates tumor biology in a context-dependent and complex manner. Notch may act as an oncogene or a tumor-suppressor gene even within the same tumor type. Recently, Notch signaling has been implicated in cellular senescence. Yet, it remains unclear as to how cellular senescence checkpoint functions may interact with Notch-mediated oncogenic and tumor-suppressor activities. Herein, we used genetically engineered human esophageal keratinocytes and esophageal squamous cell carcinoma cells to delineate the functional consequences of Notch activation and inhibition along with pharmacological intervention and RNA interference experiments. When expressed in a tetracycline-inducible manner, the ectopically expressed activated form of Notch1 (ICN1) displayed oncogene-like characteristics inducing cellular senescence corroborated by the induction of G0/G1 cell-cycle arrest, Rb dephosphorylation, flat and enlarged cell morphology and senescence-associated β-galactosidase activity. Notch-induced senescence involves canonical CSL/RBPJ-dependent transcriptional activity and the p16(INK4A)-Rb pathway. Loss of p16(INK4A) or the presence of human papilloma virus (HPV) E6/E7 oncogene products not only prevented ICN1 from inducing senescence but permitted ICN1 to facilitate anchorage-independent colony formation and xenograft tumor growth with increased cell proliferation and reduced squamous-cell differentiation. Moreover, Notch1 appears to mediate replicative senescence as well as transforming growth factor-β-induced cellular senescence in non-transformed cells and that HPV E6/E7 targets Notch1 for inactivation to prevent senescence, revealing a tumor-suppressor attribute of endogenous Notch1. In aggregate, cellular senescence checkpoint functions may influence dichotomous Notch activities in the neoplastic context.

  19. The Mouse SAGE Site: database of public mouse SAGE libraries.

    PubMed

    Divina, Petr; Forejt, Jirí

    2004-01-01

    The Mouse SAGE Site is a web-based database of all available public libraries generated by the Serial Analysis of Gene Expression (SAGE) from various mouse tissues and cell lines. The database contains mouse SAGE libraries organized in a uniform way and provides web-based tools for browsing, comparing and searching SAGE data with reliable tag-to-gene identification. A modified approach based on the SAGEmap database is used for reliable tag identification. The Mouse SAGE Site is maintained on an ongoing basis at the Institute of Molecular Genetics, Academy of Sciences of the Czech Republic and is accessible at the internet address http://mouse.biomed.cas.cz/sage/.

  20. A Sleeping Beauty screen reveals NF-kB activation in CLL mouse model

    PubMed Central

    Zanesi, Nicola; Balatti, Veronica; Riordan, Jesse; Burch, Aaron; Rizzotto, Lara; Palamarchuk, Alexey; Cascione, Luciano; Lagana, Alessandro; Dupuy, Adam J.; Croce, Carlo M.

    2013-01-01

    TCL1 oncogene is overexpressed in aggressive form of human chronic lymphocytic leukemia (CLL) and its dysregulation in mouse B cells causes a CD5-positive leukemia similar to the aggressive form of human CLLs. To identify oncogenes that cooperate with Tcl1, we performed genetic screen in Eμ−TCL1 mice using Sleeping Beauty transposon-mediated mutagenesis. Analysis of transposon common insertion sites identified 7 genes activated by transposon insertions. Overexpression of these genes in mouse CLL was confirmed by real time reverse transcription-polymerase chain reaction. Interestingly, the main known function of 4 of 7 genes (Nfkb1, Tab2, Map3K14, and Nfkbid) is participation in or activation of the nuclear factor-kB (NF-kB) pathway. In addition, activation of the NF-kB is 1 of main functions of Akt2, also identified in the screen. These findings demonstrate cooperation of Tcl1 and the NF-kB pathway in the pathogenesis of aggressive CLL. Identification cooperating cancer genes will result in the development of combinatorial therapies to treat CLL. PMID:23591791

  1. A Sleeping Beauty screen reveals NF-kB activation in CLL mouse model.

    PubMed

    Zanesi, Nicola; Balatti, Veronica; Riordan, Jesse; Burch, Aaron; Rizzotto, Lara; Palamarchuk, Alexey; Cascione, Luciano; Lagana, Alessandro; Dupuy, Adam J; Croce, Carlo M; Pekarsky, Yuri

    2013-05-23

    TCL1 oncogene is overexpressed in aggressive form of human chronic lymphocytic leukemia (CLL) and its dysregulation in mouse B cells causes a CD5-positive leukemia similar to the aggressive form of human CLLs. To identify oncogenes that cooperate with Tcl1, we performed genetic screen in Eμ-TCL1 mice using Sleeping Beauty transposon-mediated mutagenesis. Analysis of transposon common insertion sites identified 7 genes activated by transposon insertions. Overexpression of these genes in mouse CLL was confirmed by real time reverse transcription-polymerase chain reaction. Interestingly, the main known function of 4 of 7 genes (Nfkb1, Tab2, Map3K14, and Nfkbid) is participation in or activation of the nuclear factor-kB (NF-kB) pathway. In addition, activation of the NF-kB is 1 of main functions of Akt2, also identified in the screen. These findings demonstrate cooperation of Tcl1 and the NF-kB pathway in the pathogenesis of aggressive CLL. Identification cooperating cancer genes will result in the development of combinatorial therapies to treat CLL. PMID:23591791

  2. Detection of the c-myc oncogene product in colonic polyps and carcinomas.

    PubMed Central

    Stewart, J.; Evan, G.; Watson, J.; Sikora, K.

    1986-01-01

    The c-myc oncogene has been implicated in the processes of normal cell proliferation and differentiation. Elevated levels of c-myc mRNA and its gene product (p62c-myc), have been detected in a variety of solid tumours and cultured cel lines. Its precise role in normal cell function and in neoplastic transformation and progression has yet to be elucidated. We have used a monoclonal antibody, raised by peptide immunisation, to determine the distribution by immunoperoxidase staining of the c-myc oncogene product in archival specimens of colonic polyps and carcinomas. Samples from 42 patients with colon carcinoma, 24 with benign polyps and 15 normal colon biopsies were examined. Normal colon revealed maximum staining in the mid-zone of the crypts, corresponding to the zone of differentiation and maturation. The staining was predominantly cytoplasmic. Adenomatous polyps revealed the most intense pattern of staining in areas of dysplastic change. Colonic tumours showed a wide range of staining. Well differentiated tumours contained more cytoplasmic p62c-myc than poorly differentiated tumours. These findings suggest that the c-myc oncogene product may play an important role in the evolution of colonic neoplasia. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:3511934

  3. Acquired immune response to oncogenic human papillomavirus associated with prophylactic cervical cancer vaccines.

    PubMed

    Einstein, Mark H

    2008-04-01

    Human papillomavirus (HPV) is a common infection among women and a necessary cause of cervical cancer. Oncogenic HPV types infecting the anogenital tract have the potential to induce natural immunity, but at present we do not clearly understand the natural history of infection in humans and the mechanisms by which the virus can evade the host immune response. Natural acquired immune responses against HPV may be involved in the clearance of infection, but persistent infection with oncogenic virus types leads to the development of precancerous lesions and cancer. B cell responses are important for viral neutralization, but antibody responses in patients with cervical cancer are poor. Prophylactic vaccines targeting oncogenic virus types associated with cervical cancer have the potential to prevent up to 80% of cervical cancers by targeting HPV types 16 and 18. Clinical data show that prophylactic vaccines are effective in inducing antibody responses and in preventing persistent infection with HPV, as well as the subsequent development of high-grade cervical intraepithelial neoplasia. This article reviews the known data regarding natural immune responses to HPV and those developed by prophylactic vaccination.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  7. The tumor suppressor microRNA let-7 represses the HMGA2 oncogene

    PubMed Central

    Lee, Yong Sun; Dutta, Anindya

    2007-01-01

    HMGA2, a high-mobility group protein, is oncogenic in a variety of tumors, including benign mesenchymal tumors and lung cancers. Knockdown of Dicer in HeLa cells revealed that the HMGA2 gene is transcriptionally active, but its mRNA is destabilized in the cytoplasm through the microRNA (miRNA) pathway. HMGA2 was derepressed upon inhibition of let-7 in cells with high levels of the miRNA. Ectopic expression of let-7 reduced HMGA2 and cell proliferation in a lung cancer cell. The effect of let-7 on HMGA2 was dependent on multiple target sites in the 3′ untranslated region (UTR), and the growth-suppressive effect of let-7 on lung cancer cells was rescued by overexpression of the HMGA2 ORF without a 3′UTR. Our results provide a novel example of suppression of an oncogene by a tumor-suppressive miRNA and suggest that some tumors activate the oncogene through chromosomal translocations that eliminate the oncogene’s 3′UTR with the let-7 target sites. PMID:17437991

  8. Tissue-specific p19Arf regulation dictates the response to oncogenic K-ras.

    PubMed

    Young, Nathan P; Jacks, Tyler

    2010-06-01

    The ability of oncogenes to engage tumor suppressor pathways represents a key regulatory mechanism that can limit the outgrowth of incipient tumor cells. For example, in a number of settings oncogenic Ras strongly activates the Ink4a/Arf locus, resulting in cell cycle arrest or senescence. The capacity of different cell types to execute tumor suppressor programs following expression of endogenous K-ras(G12D) in vivo has not been examined. Using compound mutant mice containing the Arf(GFP) reporter and the spontaneously activating K-ras(LA2) allele, we have uncovered dramatic tissue specificity of K-ras(G12D)-dependent p19(Arf) up-regulation. Lung tumors, which can arise in the presence of functional p19(Arf), rarely display p19(Arf) induction. In contrast, sarcomas always show robust activation, which correlates with genetic evidence, suggesting that loss of the p19(Arf)-p53 pathway is a requisite event for sarcomagenesis. Using constitutive and inducible RNAi systems in vivo, we highlight cell type-specific chromatin regulation of Ink4a/Arf as a critical determinant of cellular responses to oncogenic K-ras. Polycomb-group complexes repress the locus in lung tumors, whereas the SWI/SNF family member Snf5 acts as an important mediator of p19(Arf) induction in sarcomas. This variation in tumor suppressor induction might explain the inherent differences between tissues in their sensitivity to Ras-mediated transformation. PMID:20479239

  9. Aging-associated inflammation promotes selection for adaptive oncogenic events in B cell progenitors.

    PubMed

    Henry, Curtis J; Casás-Selves, Matias; Kim, Jihye; Zaberezhnyy, Vadym; Aghili, Leila; Daniel, Ashley E; Jimenez, Linda; Azam, Tania; McNamee, Eoin N; Clambey, Eric T; Klawitter, Jelena; Serkova, Natalie J; Tan, Aik Choon; Dinarello, Charles A; DeGregori, James

    2015-12-01

    The incidence of cancer is higher in the elderly; however, many of the underlying mechanisms for this association remain unexplored. Here, we have shown that B cell progenitors in old mice exhibit marked signaling, gene expression, and metabolic defects. Moreover, B cell progenitors that developed from hematopoietic stem cells (HSCs) transferred from young mice into aged animals exhibited similar fitness defects. We further demonstrated that ectopic expression of the oncogenes BCR-ABL, NRAS(V12), or Myc restored B cell progenitor fitness, leading to selection for oncogenically initiated cells and leukemogenesis specifically in the context of an aged hematopoietic system. Aging was associated with increased inflammation in the BM microenvironment, and induction of inflammation in young mice phenocopied aging-associated B lymphopoiesis. Conversely, a reduction of inflammation in aged mice via transgenic expression of α-1-antitrypsin or IL-37 preserved the function of B cell progenitors and prevented NRAS(V12)-mediated oncogenesis. We conclude that chronic inflammatory microenvironments in old age lead to reductions in the fitness of B cell progenitor populations. This reduced progenitor pool fitness engenders selection for cells harboring oncogenic mutations, in part due to their ability to correct aging-associated functional defects. Thus, modulation of inflammation--a common feature of aging--has the potential to limit aging-associated oncogenesis.

  10. Cellular oncogene expression following exposure of mice to {gamma}-rays

    SciTech Connect

    Anderson, A.; Woloschak, G.E.

    1991-06-12

    We examined the effects of total body exposure of BCF1 mice to {gamma}-rays (300 cGy) in modulating expression of cellular oncogenes in both gut and liver tissues. We selected specific cellular oncogenes (c-fos, c-myc, c-src, and c-H-ras), based on their normal expression in liver and gut tissues from untreated mice. As early as 5 min. following whole body exposure of BCF1 mice to {gamma}-rays we detected induction of mRNA specific for c-src and c-H-ras in both liver and gut tissues. c-fos RNA was slightly decreased in accumulation in gut but was unaffected in liver tissue from irradiated mice relative to untreated controls. c-myc mRNA accumulation was unaffected in all tissues examined. These experiments document that modulation of cellular oncogene expression can occur as an early event in tissues following irradiation and suggest that this modulation may play a role in radiation-induced carcinogenesis.

  11. Hepatoma-derived growth factor/nucleolin axis as a novel oncogenic pathway in liver carcinogenesis.

    PubMed

    Chen, San-Cher; Hu, Tsung-Hui; Huang, Chao-Cheng; Kung, Mei-Lang; Chu, Tian-Huei; Yi, Li-Na; Huang, Shih-Tsung; Chan, Hoi-Hung; Chuang, Jiin-Haur; Liu, Li-Feng; Wu, Han-Chung; Wu, Deng-Chyang; Chang, Min-Chi; Tai, Ming-Hong

    2015-06-30

    Hepatoma-derived growth factor (HDGF) overexpression is involved in liver fibrosis and carcinogenesis. However, the receptor(s) and signaling for HDGF remain unclear. By using affinity chromatography and proteomic techniques, nucleolin (NCL) was identified and validated as a HDGF-interacting membrane protein in hepatoma cells. Exogenous HDGF elicited the membrane NCL accumulation within 0.5 hour by protein stabilization and transcriptional NCL upregulation within 24 hours. Blockade of surface NCL by antibodies neutralization potently suppressed HDGF uptake and HDGF-stimulated phosphatidylinositol 3-kinase (PI3K)/Akt signaling in hepatoma cells. By using rescectd hepatocellular carcinoma (HCC) tissues, immunohistochemical analysis revealed NCL overexpression was correlated with tumour grades, vascular invasion, serum alpha-fetoprotein levels and the poor survival in HCC patients. Multivariate analysis showed NCL was an independent prognostic factor for survival outcome of HCC patients after surgery. To delineate the role of NCL in liver carcinogenesis, ectopic NCL overexpression promoted the oncogenic behaviours and induced PI3K/Akt activation in hepatoma cells. Conversely, NCL knockdown by RNA interference attenuated the oncogenic behaviours and PI3K/Akt signaling, which could be partially rescued by exogenous HDGF supply. In summary, this study provides the first evidence that surface NCL transmits the oncogenic signaling of HDGF and facilitates a novel diagnostic and therapeutic target for HCC. PMID:25938538

  12. DEK Proto-Oncogene Expression Interferes with the Normal Epithelial Differentiation Program

    PubMed Central

    Wise-Draper, Trisha M.; Morreale, Richard J.; Morris, Teresa A.; Mintz-Cole, Rachael A.; Hoskins, Elizabeth E.; Balsitis, Scott J.; Husseinzadeh, Nader; Witte, David P.; Wikenheiser-Brokamp, Kathryn A.; Lambert, Paul F.; Wells, Susanne I.

    2009-01-01

    Overexpression of the DEK gene is associated with multiple human cancers, but its specific roles as a putative oncogene are not well defined. DEK transcription was previously shown to be induced by the high-risk human papillomavirus (HPV) E7 oncogene via E2F and Rb pathways. Transient DEK overexpression was able to inhibit both senescence and apoptosis in cultured cells. In at least the latter case, this mechanism involved the destabilization of p53 and the decreased expression of p53 target genes. We show here that DEK overexpression disrupts the normal differentiation program in a manner that is independent of either p53 or cell death. DEK expression was distinctly repressed upon the differentiation of cultured primary human keratinocytes, and stable DEK overexpression caused epidermal thickening in an organotypic raft model system. The observed hyperplasia involved a delay in keratinocyte differentiation toward a more undifferentiated state, and expansion of the basal cell compartment was due to increased proliferation, but not apoptosis. These phenotypes were accompanied by elevated p63 expression in the absence of p53 destabilization. In further support of bona fide oncogenic DEK activities, we report here up-regulated DEK protein levels in both human papilloma virus-positive hyperplastic murine skin and a subset of human squamous cell carcinomas. We suggest that DEK up-regulation may contribute to carcinoma development at least in part through increased proliferation and retardation of differentiation. PMID:19036808

  13. Common Oncogene Mutations and Novel SND1-BRAF Transcript Fusion in Lung Adenocarcinoma from Never Smokers

    PubMed Central

    Jang, Jin Sung; Lee, Adam; Li, Jun; Liyanage, Hema; Yang, Yanan; Guo, Lixia; Asmann, Yan W.; Li, Peter W.; Erickson-Johnson, Michele; Sakai, Yuta; Sun, ZhiFu; Jeon, Hyo-Sung; Hwang, Hayoung; Bungum, Aaron O.; Edell, Eric S.; Simon, Vernadette A.; Kopp, Karla J.; Eckloff, Bruce; Oliveira, Andre M.; Wieben, Eric; Aubry, Marie Christine; Yi, Eunhee; Wigle, Dennis; Diasio, Robert B.; Yang, Ping; Jen, Jin

    2015-01-01

    Lung adenocarcinomas from never smokers account for approximately 15 to 20% of all lung cancers and these tumors often carry genetic alterations that are responsive to targeted therapy. Here we examined mutation status in 10 oncogenes among 89 lung adenocarcinomas from never smokers. We also screened for oncogene fusion transcripts in 20 of the 89 tumors by RNA-Seq. In total, 62 tumors had mutations in at least one of the 10 oncogenes, including EGFR (49 cases, 55%), K-ras (5 cases, 6%), BRAF (4 cases, 5%), PIK3CA (3 cases, 3%), and ERBB2 (4 cases, 5%). In addition to ALK fusions identified by IHC/FISH in four cases, two previously known fusions involving EZR- ROS1 and KIF5B-RET were identified by RNA-Seq as well as a third novel fusion transcript that was formed between exons 1–9 of SND1 and exons 2 to 3′ end of BRAF. This in-frame fusion was observed in 3/89 tested tumors and 2/64 additional never smoker lung adenocarcinoma samples. Ectopic expression of SND1-BRAF in H1299 cells increased phosphorylation levels of MEK/ERK, cell proliferation, and spheroid formation compared to parental mock-transfected control. Jointly, our results suggest a potential role of the novel BRAF fusion in lung cancer development and therapy. PMID:25985019

  14. Pin1 is required for sustained B cell proliferation upon oncogenic activation of Myc

    PubMed Central

    D'Artista, Luana; Bisso, Andrea; Piontini, Andrea; Doni, Mirko; Verrecchia, Alessandro; Kress, Theresia R.; Morelli, Marco J.; Del Sal, Giannino; Amati, Bruno; Campaner, Stefano

    2016-01-01

    The c-myc proto-oncogene is activated by translocation in Burkitt's lymphoma and substitutions in codon 58 stabilize the Myc protein or augment its oncogenic potential. In wild-type Myc, phosphorylation of Ser 62 and Thr 58 provides a landing pad for the peptidyl prolyl-isomerase Pin1, which in turn promotes Ser 62 dephosphorylation and Myc degradation. However, the role of Pin1 in Myc-induced lymphomagenesis remains unknown. We show here that genetic ablation of Pin1 reduces lymphomagenesis in Eμ-myc transgenic mice. In both Pin1-deficient B-cells and MEFs, the proliferative response to oncogenic Myc was selectively impaired, with no alterations in Myc-induced apoptosis or mitogen-induced cell cycle entry. This proliferative defect wasn't attributable to alterations in either Ser 62 phosphorylation or Myc-regulated transcription, but instead relied on the activity of the ARF-p53 pathway. Pin1 silencing in lymphomas retarded disease progression in mice, making Pin1 an attractive therapeutic target in Myc-driven tumors. PMID:26943576

  15. Transmembrane voltage potential of somatic cells controls oncogene-mediated tumorigenesis at long-range

    PubMed Central

    Chernet, Brook T.; Levin, Michael

    2014-01-01

    The microenvironment is increasingly recognized as a crucial aspect of cancer. In contrast and complement to the field's focus on biochemical factors and extracellular matrix, we characterize a novel aspect of host:tumor interaction – endogenous bioelectric signals among non-excitable somatic cells. Extending prior work focused on the bioelectric state of cancer cells themselves, we show for the first time that the resting potentials of distant cells are critical for oncogene-dependent tumorigenesis. In the Xenopus laevis tadpole model, we used human oncogenes such as mutant KRAS to drive formation of tumor-like structures that exhibited overproliferation, increased nuclear size, hypoxia, acidity, and leukocyte attraction. Remarkably, misexpression of hyperpolarizing ion channels at distant sites within the tadpole significantly reduced the incidence of these tumors. The suppression of tumorigenesis could also be achieved by hyperpolarization using native CLIC1 chloride channels, suggesting a treatment modality not requiring gene therapy. Using a dominant negative approach, we implicate HDAC1 as the mechanism by which resting potential changes affect downstream cell behaviors. Based on published data on the voltage-mediated changes of butyrate flux through the SLC5A8 transporter, we present a model linking resting potentials of host cells to the ability of oncogenes to initiate tumorigenesis. Antibiotic data suggest that the relevant butyrate is generated by a native bacterial species, identifying a novel link between the microbiome and cancer that is mediated by alterations in bioelectric signaling. PMID:24830454

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

    PubMed Central

    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.

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

    PubMed

    Rennoll, Sherri A; Eshelman, Melanie A; Raup-Konsavage, Wesley M; Kawasawa, Yuka Imamura; Yochum, Gregory S

    2016-01-01

    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. PMID:27223305

  18. Detection of Enhancer-Associated Rearrangements Reveals Mechanisms of Oncogene Dysregulation in B-cell Lymphoma

    PubMed Central

    Ryan, Russell J.H.; Drier, Yotam; Whitton, Holly; Cotton, M. Joel; Kaur, Jasleen; Issner, Robbyn; Gillespie, Shawn; Epstein, Charles B.; Nardi, Valentina; Sohani, Aliyah R.; Hochberg, Ephraim P.; Bernstein, Bradley E.

    2015-01-01

    B-cell lymphomas frequently contain genomic rearrangements that lead to oncogene activation by heterologous distal regulatory elements. We utilized a novel approach, termed ‘Pinpointing Enhancer-Associated Rearrangements by Chromatin Immunoprecipitation’ or PEAR-ChIP, to simultaneously map enhancer activity and proximal rearrangements in lymphoma cell lines and patient biopsies. This method detects rearrangements involving known cancer genes, including CCND1, BCL2, MYC, PDCD1LG2, NOTCH1, CIITA, and SGK1, as well as novel enhancer duplication events of likely oncogenic significance. We identify lymphoma subtype-specific enhancers in the MYC locus that are silenced in lymphomas with MYC-activating rearrangements and are associated with germline polymorphisms that alter lymphoma risk. We show that BCL6-locus enhancers are acetylated by the BCL6-activating transcription factor MEF2B, and can undergo genomic duplication, or target the MYC promoter for activation in the context of a “pseudo-double-hit” t(3;8)(q27;q24) rearrangement linking the BCL6 and MYC loci. Our work provides novel insights regarding enhancer-driven oncogene activation in lymphoma. PMID:26229090

  19. Recognition of Human Oncogenic Viruses by Host Pattern-Recognition Receptors

    PubMed Central

    Di Paolo, Nelson C.

    2014-01-01

    Human oncogenic viruses include Epstein–Barr virus, hepatitis B virus, hepatitis C virus, human papilloma virus, human T-cell lymphotropic virus, Kaposi’s associated sarcoma virus, and Merkel cell polyomavirus. It would be expected that during virus–host interaction, the immune system would recognize these pathogens and eliminate them. However, through evolution, these viruses have developed a number of strategies to avoid such an outcome and successfully establish chronic infections. The persistent nature of the infection caused by these viruses is associated with their oncogenic potential. In this article, we will review the latest information on the interaction between oncogenic viruses and the innate immune system of the host. In particular, we will summarize the available knowledge on the recognition by host pattern-recognition receptors of pathogen-associated molecular patterns present in the incoming viral particle or generated during the virus’ life cycle. We will also review the data on the recognition of cell-derived danger associated molecular patterns generated during the virus infection that may impact the outcome of the host–pathogen interaction and the development cancer. PMID:25101093

  20. Bim Regulation of Lumen Formation in Cultured Mammary Epithelial Acini Is Targeted by Oncogenes

    PubMed Central

    Reginato, Mauricio J.; Mills, Kenna R.; Becker, Esther B. E.; Lynch, Danielle K.; Bonni, Azad; Muthuswamy, Senthil K.; Brugge, Joan S.

    2005-01-01

    Epithelial cells organize into cyst-like structures that contain a spherical monolayer of cells that enclose a central lumen. Using a three-dimensional basement membrane culture model in which mammary epithelial cells form hollow, acinus-like structures, we previously demonstrated that lumen formation is achieved, in part, through apoptosis of centrally localized cells. We demonstrate that the proapoptotic protein Bim may selectively trigger apoptosis of the centrally localized acinar cells, leading to temporally controlled lumen formation. Bim is not detectable during early stages of three-dimensional mammary acinar morphogenesis and is then highly upregulated in all cells of acini, coincident with detection of apoptosis in the centrally localized acinar cells. Inhibition of Bim expression by RNA interference transiently blocks luminal apoptosis and delays lumen formation. Oncogenes that induce acinar luminal filling, such as ErbB2 and v-Src, suppress expression of Bim through a pathway dependent on Erk-mitogen-activated protein kinase; however, HPV 16 E7, an oncogene that stimulates cell proliferation but not luminal filling, is unable to reduce Bim expression. Thus, Bim is a critical regulator of luminal apoptosis during mammary acinar morphogenesis in vitro and may be an important target of oncogenes that disrupt glandular epithelial architecture. PMID:15899862

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

    PubMed Central

    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

  2. Oncogenic KRAS regulates BMP4 expression in colon cancer cell lines.

    PubMed

    Duerr, Eva-Maria; Mizukami, Yusuke; Moriichi, Kentaro; Gala, Manish; Jo, Won-Seok; Kikuchi, Hirotoshi; Xavier, Ramnik J; Chung, Daniel C

    2012-05-15

    Activating mutations in the KRAS oncogene are common in colorectal cancer. However, the complete spectrum of KRAS targets that mediate its tumorigenic effect has not yet been fully delineated. We identified bone morphogenetic protein 4 (Bmp4), a transforming growth factor-β family member that regulates development and tissue homeostasis, as a new target of KRAS. In SW480, Hela, and 293 cells, oncogenic KRAS(V12) downregulated BMP4 RNA levels, a BMP4 promoter luciferase construct, and Bmp4 protein levels. The MEK inhibitor PD98059 but not the phosphatidylinositol 3-kinase inhibitor LY294002 blocked this downregulation of BMP4. To identify the region of the BMP4 promoter that mediated this regulation by KRAS, serial 5'-deletions of the promoter were generated. An inhibitory region was identified between -3,285 and -3,258 bp in the Bmp4 promoter. In summary, oncogenic KRAS can downregulate Bmp4 through a transcriptional pathway that depends on ERK. These findings point to a unique link between two pathways that are frequently altered in colon cancer.

  3. Recognition of human oncogenic viruses by host pattern-recognition receptors.

    PubMed

    Di Paolo, Nelson C

    2014-01-01

    Human oncogenic viruses include Epstein-Barr virus, hepatitis B virus, hepatitis C virus, human papilloma virus, human T-cell lymphotropic virus, Kaposi's associated sarcoma virus, and Merkel cell polyomavirus. It would be expected that during virus-host interaction, the immune system would recognize these pathogens and eliminate them. However, through evolution, these viruses have developed a number of strategies to avoid such an outcome and successfully establish chronic infections. The persistent nature of the infection caused by these viruses is associated with their oncogenic potential. In this article, we will review the latest information on the interaction between oncogenic viruses and the innate immune system of the host. In particular, we will summarize the available knowledge on the recognition by host pattern-recognition receptors of pathogen-associated molecular patterns present in the incoming viral particle or generated during the virus' life cycle. We will also review the data on the recognition of cell-derived danger associated molecular patterns generated during the virus infection that may impact the outcome of the host-pathogen interaction and the development cancer.

  4. PIK3CA is implicated as an oncogene in ovarian cancer

    SciTech Connect

    Shayesteh, Laleh; Lu, Yiling; Kuo, Wen-Lin; Baldocchi, Russell; Godfrey, Tony; Collins, Colin; Pinkel, Daniel; Powell, Bethan; Mills,Gordon B.; Gray, Joe W.

    1998-03-25

    Ovarian cancer is the leading cause of death from gynecological malignancy and the fourth leading cause of cancer death among American women, yet little is known about its molecular aetiology. Studies using comparative genomic hybridization (CGH) have revealed several regions of recurrent, abnormal, DNA sequence copy number that may encode genes involved in the genesis or progression of the disease. One region at 3q26 found to be increased in copy number in approximately 40 percent of ovarian and other cancers contains PIK3CA, which encodes the p110 a catalytic subunit of phosphatidylinositol 3-kinase(PI3-kinase). The association between PIK3CA copy number and PI3-kinase activity makes PIK3CA a candidate oncogene because a broad range of cancer-related functions have been associated with PI3-kinase mediated signaling. These include proliferation, glucose transport and catabolism, cell adhesion, apoptosis, RAS signaling and oncogenic transformation. In addition, downstream effectors of PI3-kinase,AKT1 and AKT2, have been found to be amplified or activated in human tumors, including ovarian cancer. We show here that PIK3CA is frequently increased in copy number in ovarian cancers, that the increased copy number is associated with increased PIK3CA transcription, p110 a protein expression and PI3-kinase activity and that treatment with the PI3-kinase inhibitor LY294002 decreases proliferation and increases apoptosis. Our observations suggest PIK3CA is an oncogene that has an important role in ovarian cancer.

  5. Common Oncogene Mutations and Novel SND1-BRAF Transcript Fusion in Lung Adenocarcinoma from Never Smokers.

    PubMed

    Jang, Jin Sung; Lee, Adam; Li, Jun; Liyanage, Hema; Yang, Yanan; Guo, Lixia; Asmann, Yan W; Li, Peter W; Erickson-Johnson, Michele; Sakai, Yuta; Sun, ZhiFu; Jeon, Hyo-Sung; Hwang, Hayoung; Bungum, Aaron O; Edell, Eric S; Simon, Vernadette A; Kopp, Karla J; Eckloff, Bruce; Oliveira, Andre M; Wieben, Eric; Aubry, Marie Christine; Yi, Eunhee; Wigle, Dennis; Diasio, Robert B; Yang, Ping; Jen, Jin

    2015-05-18

    Lung adenocarcinomas from never smokers account for approximately 15 to 20% of all lung cancers and these tumors often carry genetic alterations that are responsive to targeted therapy. Here we examined mutation status in 10 oncogenes among 89 lung adenocarcinomas from never smokers. We also screened for oncogene fusion transcripts in 20 of the 89 tumors by RNA-Seq. In total, 62 tumors had mutations in at least one of the 10 oncogenes, including EGFR (49 cases, 55%), K-ras (5 cases, 6%), BRAF (4 cases, 5%), PIK3CA (3 cases, 3%), and ERBB2 (4 cases, 5%). In addition to ALK fusions identified by IHC/FISH in four cases, two previously known fusions involving EZR- ROS1 and KIF5B-RET were identified by RNA-Seq as well as a third novel fusion transcript that was formed between exons 1-9 of SND1 and exons 2 to 3' end of BRAF. This in-frame fusion was observed in 3/89 tested tumors and 2/64 additional never smoker lung adenocarcinoma samples. Ectopic expression of SND1-BRAF in H1299 cells increased phosphorylation levels of MEK/ERK, cell proliferation, and spheroid formation compared to parental mock-transfected control. Jointly, our results suggest a potential role of the novel BRAF fusion in lung cancer development and therapy.

  6. Individual and Complementary Effects of Human Papillomavirus Oncogenes on Epithelial Cell Proliferation and Differentiation.

    PubMed

    Bergner, Sven; Halec, Gordana; Schmitt, Markus; Aubin, François; Alonso, Angel; Auvinen, Eeva

    2016-01-01

    Previous studies on human papillomavirus (HPV) type 16 protein functions have established the oncogenic nature of three viral proteins: E5, E6 and E7. Here we have studied the functions of these proteins by functional deletion of the individual E5, E6 or E7, or both E6 and E7 oncogenes in the context of the whole viral genome. These mutants, or the intact wild-type genome, were expressed from the natural viral promoters along with differentiation of epithelial HaCaT cells in three-dimensional collagen raft cultures. High episomal viral copy numbers were obtained using a transfection-based loxp-HPV16-eGFP-N1 vector system. All epithelial equivalents carrying the different HPV type 16 genomes showed pronounced hyperplastic and dysplastic morphology. Particularly the E7 oncogene, with contribution of E6, was shown to enhance cell proliferation. Specifically, the crucial role of E7 in HPV-associated hyperproliferation was clearly manifested. Based on morphological characteristics, immunohistochemical staining for differentiation and proliferation markers, and low expression of E1^E4, we propose that our raft culture models produce cervical intraepithelial neoplasia (CIN)1 and CIN2-like tissue. Our experimental setting provides an alternative tool to study concerted functions of HPV proteins in the development of epithelial dysplasia. PMID:26636751

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

    PubMed Central

    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

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

    PubMed

    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

    2015-01-01

    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. PMID:26515758

  9. Transmembrane voltage potential of somatic cells controls oncogene-mediated tumorigenesis at long-range.

    PubMed

    Chernet, Brook T; Levin, Michael

    2014-05-30

    The microenvironment is increasingly recognized as a crucial aspect of cancer. In contrast and complement to the field's focus on biochemical factors and extracellular matrix, we characterize a novel aspect of host:tumor interaction - endogenous bioelectric signals among non-excitable somatic cells. Extending prior work focused on the bioelectric state of cancer cells themselves, we show for the first time that the resting potentials of distant cells are critical for oncogene-dependent tumorigenesis. In the Xenopus laevis tadpole model, we used human oncogenes such as mutant KRAS to drive formation of tumor-like structures that exhibited overproliferation, increased nuclear size, hypoxia, acidity, and leukocyte attraction. Remarkably, misexpression of hyperpolarizing ion channels at distant sites within the tadpole significantly reduced the incidence of these tumors. The suppression of tumorigenesis could also be achieved by hyperpolarization using native CLIC1 chloride channels, suggesting a treatment modality not requiring gene therapy. Using a dominant negative approach, we implicate HDAC1 as the mechanism by which resting potential changes affect downstream cell behaviors. Based on published data on the voltage-mediated changes of butyrate flux through the SLC5A8 transporter, we present a model linking resting potentials of host cells to the ability of oncogenes to initiate tumorigenesis. Antibiotic data suggest that the relevant butyrate is generated by a native bacterial species, identifying a novel link between the microbiome and cancer that is mediated by alterations in bioelectric signaling. PMID:24830454

  10. Structure and transforming potential of the human cot oncogene encoding a putative protein kinase.

    PubMed Central

    Miyoshi, J; Higashi, T; Mukai, H; Ohuchi, T; Kakunaga, T

    1991-01-01

    A new transforming gene has been molecularly cloned from hamster SHOK cells transformed with DNA extracted from a human thyroid carcinoma cell line and named the cot (cancer Osaka thyroid) oncogene. cDNA sequencing disclosed that this oncogene codes for a protein with 415 amino acid residues, and computer matching showed 42 to 48% similarity matches with serine protein kinases. Its gene product was identified as a 52-kDa protein by transcription and translation in vitro. Expression of cot cDNA under transcriptional control by a retroviral long terminal repeat induced morphological transformation of NIH 3T3 cells as well as SHOK cells. Protein kinase activity associated with constructed p60gag-cot was detected by immune complex kinase assay with anti-gag antiserum. The cot oncogene was overexpressed in transformed SHOK cells and found to have a rearranged 3' end in the last coding exon, which probably resulted in a deletion and an altered C' terminus in the transforming protein. This DNA rearrangement appeared to have occurred during transfection of the tumor DNA into hamster SHOK cells and not in the original thyroid tumor. Images PMID:2072910

  11. Oncogenic features of the bone morphogenic protein 7 (BMP7) in pheochromocytoma

    PubMed Central

    Leinhäuser, Ines; Richter, Andrea; Lee, Misu; Höfig, Ines; Anastasov, Nataša; Fend, Falko; Ercolino, Tonino; Mannelli, Massimo; Gimenez-Roqueplo, Anne-Paule; Robledo, Mercedes; de Krijger, Ronald; Beuschlein, Felix; Atkinson, Michael J.; Pellegata, Natalia S.

    2015-01-01

    BMP7 is a growth factor playing pro- or anti-oncogenic roles in cancer in a cell type-dependent manner. We previously reported that the BMP7 gene is overexpressed in pheochromocytomas (PCCs) developing in MENX-affected rats and human patients. Here, analyzing a large cohort of PCC patients, we found that 72% of cases showed elevated levels of the BMP7 protein. To elucidate the role of BMP7 in PCC, we modulated its levels in PCC cell lines (overexpression in PC12, knockdown in MPC and MTT cells) and conducted functional assays. Active BMP signaling promoted cell proliferation, migration, and invasion, and sustained survival of MENX rat primary PCC cells. In PCC, BMP7 signals through the PI3K/AKT/mTOR pathway and causes integrin β1 up-regulation. Silencing integrin β1 in PC12 cells suppressed BMP7-mediated oncogenic features. Treatment of MTT cells with DMH1, a novel BMP antagonist, suppressed proliferation and migration. To verify the clinical applicability of our findings, we evaluated a dual PI3K/mTOR inhibitor (NVP-BEZ235) in MENX-affected rats in vivo. PCCs treated with NVP-BEZ235 had decreased proliferation and integrin β1 levels, and higher apoptosis. Altogether, BMP7 activates pro-oncogenic pathways in PCC. Downstream effectors of BMP7-mediated signaling may represent novel targets for treating progressive/inoperable PCC, still orphan of effective therapy. PMID:26337467

  12. Oncogenic features of the bone morphogenic protein 7 (BMP7) in pheochromocytoma.

    PubMed

    Leinhäuser, Ines; Richter, Andrea; Lee, Misu; Höfig, Ines; Anastasov, Nataša; Fend, Falko; Ercolino, Tonino; Mannelli, Massimo; Gimenez-Roqueplo, Anne-Paule; Robledo, Mercedes; de Krijger, Ronald; Beuschlein, Felix; Atkinson, Michael J; Pellegata, Natalia S

    2015-11-17

    BMP7 is a growth factor playing pro- or anti-oncogenic roles in cancer in a cell type-dependent manner. We previously reported that the BMP7 gene is overexpressed in pheochromocytomas (PCCs) developing in MENX-affected rats and human patients. Here, analyzing a large cohort of PCC patients, we found that 72% of cases showed elevated levels of the BMP7 protein. To elucidate the role of BMP7 in PCC, we modulated its levels in PCC cell lines (overexpression in PC12, knockdown in MPC and MTT cells) and conducted functional assays. Active BMP signaling promoted cell proliferation, migration, and invasion, and sustained survival of MENX rat primary PCC cells. In PCC, BMP7 signals through the PI3K/AKT/mTOR pathway and causes integrin β1 up-regulation. Silencing integrin β1 in PC12 cells suppressed BMP7-mediated oncogenic features. Treatment of MTT cells with DMH1, a novel BMP antagonist, suppressed proliferation and migration. To verify the clinical applicability of our findings, we evaluated a dual PI3K/mTOR inhibitor (NVP-BEZ235) in MENX-affected rats in vivo. PCCs treated with NVP-BEZ235 had decreased proliferation and integrin β1 levels, and higher apoptosis. Altogether, BMP7 activates pro-oncogenic pathways in PCC. Downstream effectors of BMP7-mediated signaling may represent novel targets for treating progressive/inoperable PCC, still orphan of effective therapy. PMID:26337467

  13. A dual role for Hdac1: oncosuppressor in tumorigenesis, oncogene in tumor maintenance.

    PubMed

    Santoro, Fabio; Botrugno, Oronza A; Dal Zuffo, Roberto; Pallavicini, Isabella; Matthews, Geoffrey M; Cluse, Leonie; Barozzi, Iros; Senese, Silvia; Fornasari, Lorenzo; Moretti, Simona; Altucci, Lucia; Pelicci, Pier Giuseppe; Chiocca, Susanna; Johnstone, Ricky W; Minucci, Saverio

    2013-04-25

    Aberrant recruitment of histone deacetylases (HDACs) by the oncogenic fusion protein PML-RAR is involved in the pathogenesis of acute promyelocytic leukemia (APL). PML-RAR, however, is not sufficient to induce disease in mice but requires additional oncogenic lesions during the preleukemic phase. Here, we show that knock-down of Hdac1 and Hdac2 dramatically accelerates leukemogenesis in transgenic preleukemic mice. These events are not restricted to APL because lymphomagenesis driven by deletion of p53 or, to a lesser extent, by c-myc overexpression, was also accelerated by Hdac1 knock-down. In the preleukemic phase of APL, Hdac1 counteracts the activity of PML-RAR in (1) blocking differentiation; (2) impairing genomic stability; and (3) increasing self-renewal in hematopoietic progenitors, as all of these events are affected by the reduction in Hdac1 levels. This led to an expansion of a subpopulation of PML-RAR-expressing cells that is the major source of leukemic stem cells in the full leukemic stage. Remarkably, short-term treatment of preleukemic mice with an HDAC inhibitor accelerated leukemogenesis. In contrast, knock-down of Hdac1 in APL mice led to enhanced survival duration of the leukemic animals. Thus, Hdac1 has a dual role in tumorigenesis: oncosuppressive in the early stages, and oncogenic in established tumor cells.

  14. Development of neutralizing monoclonal antibodies for oncogenic human papillomavirus types 31, 33, 45, 52, and 58.

    PubMed

    Brown, Martha J; Seitz, Hanna; Towne, Victoria; Müller, Martin; Finnefrock, Adam C

    2014-04-01

    Human papillomavirus (HPV) is the etiological agent for all cervical cancers, a significant number of other anogenital cancers, and a growing number of head and neck cancers. Two licensed vaccines offer protection against the most prevalent oncogenic types, 16 and 18, responsible for approximately 70% of cervical cancer cases worldwide and one of these also offers protection against types 6 and 11, responsible for 90% of genital warts. The vaccines are comprised of recombinantly expressed major capsid proteins that self-assemble into virus-like particles (VLPs) and prevent infection by eliciting neutralizing antibodies. Adding the other frequently identified oncogenic types 31, 33, 45, 52, and 58 to a vaccine would increase the coverage against HPV-induced cancers to approximately 90%. We describe the generation and characterization of panels of monoclonal antibodies to these five additional oncogenic HPV types, and the selection of antibody pairs that were high affinity and type specific and recognized conformation-dependent neutralizing epitopes. Such characteristics make these antibodies useful tools for monitoring the production and potency of a prototype vaccine as well as monitoring vaccine-induced immune responses in the clinic. PMID:24574536

  15. Autocrine inhibition of the c-fms proto-oncogene reduces breast cancer bone metastasis assessed with in vivo dual-modality imaging.

    PubMed

    Jeffery, Justin J; Lux, Katie; Vogel, John S; Herrera, Wynetta D; Greco, Stephen; Woo, Ho-Hyung; AbuShahin, Nisreen; Pagel, Mark D; Chambers, Setsuko K

    2014-04-01

    Breast cancer cells preferentially home to the bone microenvironment, which provides a unique niche with a network of multiple bidirectional communications between host and tumor, promoting survival and growth of bone metastases. In the bone microenvironment, the c-fms proto-oncogene that encodes for the CSF-1 receptor, along with CSF-1, serves as one critical cytokine/receptor pair, functioning in paracrine and autocrine fashion. Previous studies concentrated on the effect of inhibition of host (mouse) c-fms on bone metastasis, with resulting decrease in osteolysis and bone metastases as a paracrine effect. In this report, we assessed the role of c-fms inhibition within the tumor cells (autocrine effect) in the early establishment of breast cancer cells in bone and the effects of this early c-fms inhibition on subsequent bone metastases and destruction. This study exploited a multidisciplinary approach by employing two non-invasive, in vivo imaging methods to assess the progression of bone metastases and bone destruction, in addition to ex vivo analyses using RT-PCR and histopathology. Using a mouse model of bone homing human breast cancer cells, we showed that an early one-time application of anti-human c-fms antibody delayed growth of bone metastases and bone destruction for at least 31 days as quantitatively measured by bioluminescence imaging and computed tomography, compared to controls. Thus, neutralizing human c-fms in the breast cancer cell alone decreases extent of subsequent bone metastasis formation and osteolysis. Furthermore, we are the first to show that anti-c-fms antibodies can impact early establishment of breast cancer cells in bone.

  16. Contrasting behavior of the p18INK4c and p16INK4a tumor suppressors in both replicative and oncogene-induced senescence.

    PubMed

    Gagrica, Sladjana; Brookes, Sharon; Anderton, Emma; Rowe, Janice; Peters, Gordon

    2012-01-01

    The cyclin-dependent kinase (CDK) inhibitors, p18(INK4c) and p16(INK4a), both have the credentials of tumor suppressors in human cancers and mouse models. For p16(INK4a), the underlying rationale is its role in senescence, but the selective force for inactivation of p18(INK4c) in incipient cancer cells is less clear. Here, we show that in human fibroblasts undergoing replicative or oncogene-induced senescence, there is a marked decline in the levels of p18(INK4c) protein and RNA, which mirrors the accumulation of p16(INK4a). Downregulation of INK4c is not dependent on p16(INK4a), and RAS can promote the loss of INK4c without cell-cycle arrest. Downregulation of p18(INK4c) correlates with reduced expression of menin and E2F1 but is unaffected by acute cell-cycle arrest or inactivation of the retinoblastoma protein (pRb). Collectively, our data question the idea that p18(INK4c) acts as a backup for loss of p16(INK4a) and suggest that the apparent activation of p18(INK4c) in some settings represents delayed senescence rather than increased expression. We propose that the contrasting behavior of the two very similar INK4 proteins could reflect their respective roles in senescence versus differentiation.

  17. MicroRNA-34a promotes genomic instability by a broad suppression of genome maintenance mechanisms downstream of the oncogene KSHV-vGPCR

    PubMed Central

    Krause, Claudia J.; Popp, Oliver; Thirunarayanan, Nanthakumar; Dittmar, Gunnar; Lipp, Martin; Müller, Gerd

    2016-01-01

    The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded chemokine receptor vGPCR acts as an oncogene in Kaposi's sarcomagenesis. Until now, the molecular mechanisms by which the vGPCR contributes to tumor development remain incompletely understood. Here, we show that the KSHV-vGPCR contributes to tumor progression through microRNA (miR)-34a-mediated induction of genomic instability. Large-scale analyses on the DNA, gene and protein level of cell lines derived from a mouse model of vGPCR-driven tumorigenesis revealed that a vGPCR–induced upregulation of miR-34a resulted in a broad suppression of genome maintenance genes. A knockdown of either the vGPCR or miR-34a largely restored the expression of these genes and confirmed miR-34a as a downstream effector of the KSHV-vGPCR that compromises genome maintenance mechanisms. This novel, protumorigenic role of miR-34a questions the use of miR-34a mimetics in cancer therapy as they could impair genome stability. PMID:26871287

  18. THE ONCOGENIC FUSION PROTEIN PAX3-FKHR HAS A GREATER POST-TRANSLATIONAL STABILITY RELATIVE TO PAX3 DURING EARLY MYOGENESIS

    PubMed Central

    Miller, Patrick J.; Hollenbach, Andrew D.

    2007-01-01

    SUMMARY The childhood solid muscle tumor Alveolar Rhabdomyosarcoma (ARMS) is characterized by the t(2;13)(q35;q14) chromosomal translocation, which results in the fusion of two transcription factors important for myogenesis, Pax3 and FKHR (FOX01a). The effects of myogenic differentiation on the stability of FKHR have been well characterized. However, similar studies have yet to be performed on Pax3 or the oncogenic fusion protein Pax3-FKHR. Therefore, we demonstrate in the physiologically relevant mouse primary myoblast system that the expression of Pax3 decreases nearly 95% during the first twenty-four hours of myogenic differentiation. In contrast, there is an aberrant persistence of expression of Pax3-FKHR during this same time period. These differences in protein expression levels do not result from changes on the transcriptional nor the translational level since we observed no concomitant decrease in the levels of Pax3 or Pax3-FKHR mRNA or in the ability of both proteins to be translated. Instead, a pulse-chase analysis determined that Pax3-FKHR has a half-life significantly greater than the half-life of wild type Pax3 demonstrating for the first time that Pax3-FKHR has greater post-translational protein stability relative to wild type Pax3 during early myogenic differentiation. Finally, the persistence of expression of Pax3-FKHR prevents the terminal differentiation of primary myoblasts demonstrating a biological consequence of its aberrant expression. PMID:17698292

  19. The oncogenic microRNA miR-22 targets the TET2 tumor suppressor to promote hematopoietic stem cell self-renewal and transformation

    PubMed Central

    Song, Su Jung; Ito, Keisuke; Ala, Ugo; Kats, Lev; Webster, Kaitlyn; Sun, Suming; Manova-Todorova, Katia; Teruya-Feldstein, Julie; Avigan, David E.; Delwel, Ruud; Pandolfi, Pier Paolo

    2013-01-01

    SUMMARY MicroRNAs are frequently deregulated in cancer. Here we show that miR-22 is upregulated in myelodysplastic syndrome (MDS) and leukemia, and its aberrant expression correlates with poor survival. To explore its role in hematopoietic stem cell function and malignancy, we generated transgenic mice conditionally expressing miR-22 in the hematopoietic compartment. These mice displayed reduced levels of global 5-hydroxymethylcytosine (5-hmC) and increased hematopoietic stem cell self-renewal, accompanied by defective differentiation. Conversely, miR-22 inhibition blocked proliferation in both mouse and human leukemic cells. Over time, miR-22 transgenic mice developed MDS and hematological malignancies. We also identify TET2 as a key target of miR-22 in this context. Ectopic expression of TET2 suppressed the miR-22-incuced phenotypes. Downregulation of TET2 protein also correlated with poor clinical outcomes and miR-22 overexpression in MDS patients. Our results therefore identify miR-22 as a potent proto-oncogene, and suggest that aberrations in the miR-22-TET2 regulatory network are common in hematopoietic malignancies. PMID:23827711

  20. V-akt murine thymoma viral oncogene homolog 3 (AKT3) contributes to poor disease outcome in humans and mice with pneumococcal meningitis.

    PubMed

    Valls Serón, Mercedes; Ferwerda, Bart; Engelen-Lee, JooYeon; Geldhoff, Madelijn; Jaspers, Valery; Zwinderman, Aeilko H; Tanck, Michael W; Baas, Frank; van der Ende, Arie; Brouwer, Matthijs C; van de Beek, Diederik

    2016-05-18

    Pneumococcal meningitis is the most common and severe form of bacterial meningitis. Fatality rates are substantial, and long-term sequelae develop in about half of survivors. Here, we have performed a prospective nationwide genetic association study using the Human Exome BeadChip and identified gene variants in encoding dynactin 4 (DCTN4), retinoic acid early transcript 1E (RAET1E), and V-akt murine thymoma viral oncogene homolog 3 (AKT3) to be associated with unfavourable outcome in patients with pneumococcal meningitis. No clinical replication cohort is available, so we validated the role of one of these targets, AKT3, in a pneumococcal meningitis mouse model. Akt3 deficient mice had worse survival and increased histopathology scores for parenchymal damage (infiltration) and vascular infiltration (large meningeal artery inflammation) but similar bacterial loads, cytokine responses, compared to wild-type mice. We found no differences in cerebrospinal fluid cytokine levels between patients with risk or non-risk alleles. Patients with the risk genotype (rs10157763, AA) presented with low scores on the Glasgow Coma Scale and high rate of epileptic seizures. Thus, our results show that AKT3 influences outcome of pneumococcal meningitis.

  1. The oncogenic microRNA miR-22 targets the TET2 tumor suppressor to promote hematopoietic stem cell self-renewal and transformation.

    PubMed

    Song, Su Jung; Ito, Keisuke; Ala, Ugo; Kats, Lev; Webster, Kaitlyn; Sun, Su Ming; Jongen-Lavrencic, Mojca; Manova-Todorova, Katia; Teruya-Feldstein, Julie; Avigan, David E; Delwel, Ruud; Pandolfi, Pier Paolo

    2013-07-01

    MicroRNAs are frequently deregulated in cancer. Here we show that miR-22 is upregulated in myelodysplastic syndrome (MDS) and leukemia and its aberrant expression correlates with poor survival. To explore its role in hematopoietic stem cell function and malignancy, we generated transgenic mice conditionally expressing miR-22 in the hematopoietic compartment. These mice displayed reduced levels of global 5-hydroxymethylcytosine (5-hmC) and increased hematopoietic stem cell self-renewal accompanied by defective differentiation. Conversely, miR-22 inhibition blocked proliferation in both mouse and human leukemic cells. Over time, miR-22 transgenic mice developed MDS and hematological malignancies. We also identify TET2 as a key target of miR-22 in this context. Ectopic expression of TET2 suppressed the miR-22-induced phenotypes. Downregulation of TET2 protein also correlated with poor clinical outcomes and miR-22 overexpression in MDS patients. Our results therefore identify miR-22 as a potent proto-oncogene and suggest that aberrations in the miR-22/TET2 regulatory network are common in hematopoietic malignancies.

  2. Overexpression of Cyclin E and its Low Molecular Weight Isoforms Cooperate with Loss of p53 in Promoting Oncogenic Properties of MCF-7 Breast Cancer Cells.

    PubMed

    Montazeri, Hamed; Bouzari, Saeid; Azadmanesh, Kayhan; Ostad, Seyed Nasser; Ghahremani, Mohammad Hossein

    2015-01-01

    Cyclin E, a key coordinator of the G1 to S transition in the cell cycle, may be deregulated in several malignancies, including breast cancer. The most significant aberration in cyclin E is its elastase mediated proteolytic cleavage into tumor specific low molecular weight isoforms (LMW-Es). LMW-Es are biochemically hyperactive and biologically drive tumorigenesis in transgenic mouse models. Additionally, expression of LMW-Es has been correlated with poor survival in breast cancer cases. Here we determine whether expression of LMW-Es in a breast cancer cell line that is naturally devoid of these deregulated forms would alter their progression through each phase of the cell cycle. The results revealed that LMW-Es expression resulted in an increased doubling time, concomitant with a predominant increase in the population in the S phase of the cell cycle. Moreover, downregulation of p53 in LMW-Es cells resulted in additional shortening of the doubling time and enrichment of cells in the S and G2/M phases of the cell cycle. Furthermore, expression of LMW-Es sensitized cells to β-estradiol (E2) mediated growth and changed expression patterns of estrogen receptor and Bcl-2. Intriguingly, expression of LMW-Es could surpass anti-apoptotic effects raised by p53 upregulation. Taken together these studies suggest that overexpression of LMW-Es in collaboration with p53 loss results in altered growth properties of MCF-7 cells, enhancing the oncogenic activity of these ER positive breast cancer cells.

  3. Progesterone promotes propagation and viability of mouse embryonic stem cells.

    PubMed

    Shen, Shan-Wei; Song, Hou-Yan

    2009-10-25

    It has been known that estrogen-17beta stimulates proliferation of mouse embryonic stem (mES) cells. To explore the function of another steroid hormone progesterone, we used MTT method and BrdU incorporation assay to obtain growth curves, clone forming assay to detect the propagation and viability of individual mES cells, Western blot to test the expression of ES cell marker gene Oct-4, fluorescence activated cell sorter (FACS) to test cell cycle, and real-time PCR to detect the expressions of cyclins, cyclin-dependent kinases and proto-oncogenes. The results showed that progesterone promoted proliferation of mES cells. The number of clones was more in progesterone-treated group than that in the control group. The expression of pluripotency-associated transcriptional factor Oct-4 changed little after progesterone treatment as shown by Western blot, indicating that most of mES cells were in undifferentiated state. The results of FACS proved that progesterone promoted DNA synthesis in mES cells. The proportion of mES cells in S+G(2)/M phase was higher in progesterone-treated group than that in the control group. Cyclins and cyclin-dependent kinases, as well as proto-oncogenes (c-myc, c-fos) were up-regulated when cells were treated with progesterone. The results obtained indicate that progesterone promotes propagation and viability of mES cells. The up-regulation of cell cycle-related factors might contribute to the function of progesterone.

  4. ISOLATION OF MOUSE NEUTROPHILS

    PubMed Central

    Swamydas, Muthulekha; Luo, Yi; Dorf, Martin E.; Lionakis, Michail S.

    2015-01-01

    Neutrophils represent the first line of defense against bacterial and fungal pathogens. Indeed, patients with inherited and acquired qualitative and quantitative neutrophil defects are at high risk for developing bacterial and fungal infections and suffering adverse outcomes from these infections. Therefore, research aiming at defining the molecular factors that modulate neutrophil effector function under homeostatic conditions and during infection is essential for devising strategies to augment neutrophil function and improve the outcome of infected individuals. This unit describes a reproducible density gradient centrifugation-based protocol that can be applied in any laboratory to harvest large numbers of highly enriched and highly viable neutrophils from the bone marrow of mice both at the steady state and following infection with Candida albicans as described in UNIT 19.6. In another protocol, we also present a method that combines gentle enzymatic tissue digestion with a positive immunomagnetic selection technique or Fluorescence-activated cell sorting (FACS) to harvest highly pure and highly viable preparations of neutrophils directly from mouse tissues such as the kidney, the liver or the spleen. Finally, methods for isolating neutrophils from mouse peritoneal fluid and peripheral blood are included. Mouse neutrophils isolated by these protocols can be used for examining several aspects of cellular function ex vivo including pathogen binding, phagocytosis and killing, neutrophil chemotaxis, oxidative burst, degranulation and cytokine production, and for performing neutrophil adoptive transfer experiments. PMID:26237011

  5. RIKEN mouse genome encyclopedia.

    PubMed

    Hayashizaki, Yoshihide

    2003-01-01

    We have been working to establish the comprehensive mouse full-length cDNA collection and sequence database to cover as many genes as we can, named Riken mouse genome encyclopedia. Recently we are constructing higher-level annotation (Functional ANnoTation Of Mouse cDNA; FANTOM) not only with homology search based annotation but also with expression data profile, mapping information and protein-protein database. More than 1,000,000 clones prepared from 163 tissues were end-sequenced to classify into 159,789 clusters and 60,770 representative clones were fully sequenced. As a conclusion, the 60,770 sequences contained 33,409 unique. The next generation of life science is clearly based on all of the genome information and resources. Based on our cDNA clones we developed the additional system to explore gene function. We developed cDNA microarray system to print all of these cDNA clones, protein-protein interaction screening system, protein-DNA interaction screening system and so on. The integrated database of all the information is very useful not only for analysis of gene transcriptional network and for the connection of gene to phenotype to facilitate positional candidate approach. In this talk, the prospect of the application of these genome resourced should be discussed. More information is available at the web page: http://genome.gsc.riken.go.jp/.

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

    PubMed

    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

  7. p38α and p38γ Mediate Oncogenic ras-induced Senescence through Differential Mechanisms*S⃞

    PubMed Central

    Kwong, Jinny; Hong, Lixin; Liao, Rong; Deng, Qingdong; Han, Jiahuai; Sun, Peiqing

    2009-01-01

    Oncogene-induced senescence is a tumor-suppressive defense mechanism triggered upon activation of certain oncogenes in normal cells. Recently, the senescence response to oncogene activation has been shown to act as a bona fide barrier to cancer development in vivo. Multiple previous studies have implicated the importance of the p38 MAPK pathway in oncogene-induced senescence. However, the contribution of each of the four p38 isoforms (encoded by different genes) to senescence induction is unclear. In the current study, we demonstrated that p38α and p38γ, but not p38β, play an essential role in oncogenic ras-induced senescence. Both p38α and p38γ are expressed in primary human fibroblasts and are activated upon transduction of oncogenic ras. Small hairpin RNA-mediated silencing of p38α or p38γ expression abrogated ras-induced senescence, whereas constitutive activation of p38α and p38γ caused premature senescence. Furthermore, upon activation by oncogenic ras, p38γ stimulated the transcriptional activity of p53 by phosphorylating p53 at Ser33, suggesting that the ability of p38γ to mediate senescence is at least partly achieved through p53. However, p38α contributed to ras-inducted senescence via a p53-indepdendent mechanism in cells by mediating ras-induced expression of p16INK4A, another key senescence effector. These findings have identified p38α and p38γ as essential components of the signaling pathway that regulates the tumor-suppressing senescence response, providing insights into the molecular mechanisms underlying the differential involvement of the p38 isoforms in senescence induction. PMID:19251701

  8. The Human Papillomavirus E6 Oncogene Dysregulates the Cell Cycle and Contributes to Cervical Carcinogenesis through Two Independent Activities

    PubMed Central

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

    2010-01-01

    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 α-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 α-helix partners. PMID:17308103

  9. In vivo quantification and perturbation of Myc-Max interactions and the impact on oncogenic potential.

    PubMed

    Raffeiner, Philipp; Röck, Ruth; Schraffl, Andrea; Hartl, Markus; Hart, Jonathan R; Janda, Kim D; Vogt, Peter K; Stefan, Eduard; Bister, Klaus

    2014-10-15

    The oncogenic bHLH-LZ transcription factor Myc forms binary complexes with its binding partner Max. These and other bHLH-LZ-based protein-protein interactions (PPI) in the Myc-Max network are essential for the physiological and oncogenic activities of Myc. We have generated a genetically determined and highly specific protein-fragment complementation assay based on Renilla luciferase to analyze the dynamic interplay of bHLH-LZ transcription factors Myc, Max, and Mxd1 in vivo. We also applied this PPI reporter to quantify alterations of nuclear Myc-Max complexes in response to mutational events, competitive binding by the transcriptional repressor Mxd1, or perturbations by small-molecule Myc inhibitors, including recently identified potent PPI inhibitors from a Kröhnke pyridine library. We show that the specificity of Myc-Max PPI reduction by the pyridine inhibitors directly correlates with their efficient and highly specific potential to interfere with the proliferation of human and avian tumor cells displaying deregulated Myc expression. In a direct comparison with known Myc inhibitors using human and avian cell systems, the pyridine compounds reveal a unique inhibitory potential even at sub-micromolar concentrations combined with remarkable specificity for the inhibition of Myc-driven tumor cell proliferation. Furthermore, we show in direct comparisons using defined avian cell systems that different Max PPI profiles for the variant members of the Myc protein family (c-Myc, v-Myc, N-Myc, L-Myc) correlate with their diverse oncogenic potential and their variable sensitivity to the novel pyridine inhibitors.

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

    PubMed

    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.

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

    PubMed

    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.

  12. The prolactin receptor mediates HOXA1-stimulated oncogenicity in mammary carcinoma cells.

    PubMed

    Hou, Lin; Xu, Bing; Mohankumar, Kumarasamypet M; Goffin, Vincent; Perry, Jo K; Lobie, Peter E; Liu, Dong-Xu

    2012-12-01

    The HOX genes are a highly conserved subgroup of homeodomain-containing transcription factors that are crucial to normal development. Forced expression of HOXA1 results in oncogenic transformation of immortalized human mammary cells with aggressive tumour formation in vivo. Microarray analysis identified that the prolactin receptor (PRLR) was significantly upregulated by forced expression of HOXA1 in mammary carcinoma cells. To determine prolactin (PRL) involvement in HOXA1‑induced oncogenicity in mammary carcinoma cells (MCF-7), we examined the effect of human prolactin (hPRL)-initiated PRLR signal transduction on changes in cellular behaviour mediated by HOXA1. Forced expression of HOXA1 in MCF-7 cells increased PRLR mRNA and protein expression. Forced expression of HOXA1 also enhanced hPRL-stimulated phosphorylation of both STAT5A/B and p44/42 MAPK, and increased subsequent transcriptional activity of STAT5A and STAT5B, and Elk-1 and Sap1a, respectively. Moreover, forced expression of HOXA1 in MCF-7 cells enhanced the hPRL‑stimulated increase in total cell number as a consequence of enhanced cell proliferation and cell survival, and also enhanced hPRL-stimulated anchorage-independent growth in soft agar. Increased anchorage-independent growth was attenuated by the PRLR antagonist ∆1-9-G129R‑hPRL. In conclusion, we have demonstrated that HOXA1 increases expression of the cell surface receptor PRLR and enhances PRLR-mediated signal transduction. Thus, the PRLR is one mediator of HOXA1‑stimulated oncogenicity in mammary carcinoma cells. PMID:23064471

  13. Associations between clinical characteristics and oncogene expression in patients with non-small cell lung cancer.

    PubMed

    Han, Y; Yu, D P; Zhou, S J; Song, X Y; Li, Y S; Xiao, N; Liu, Z D; Sun, X J; Zhao, Q Y; Liu, S K

    2014-10-31

    More than 40 oncogenes associated with non-small cell lung cancer (NSCLC) have been identified with varied gene expression. The correlations between specific clinical characteristics and oncogene expression in NSCLC patients were examined. From October 2011 to September 2012, a total of 60 patients with NSCLC (male:female, 34:24; mean age, 59.5 ± 10.6 years; age range, 31-81 years) were diagnosed and evaluated for treatment with radical resection at a single facility. Eligible patients exhibiting tumor node metastasis (TNM) stage I-III NSCLC confirmed by post-surgical pathology were included. mRNA expression was detected by branched DNA-liquidchip technology (bDNA-LCT) and mutations were detected at EGFR exons 18, 19, 20, and 21, KRAS exons 2 and 3, BRAF and PIK3CA exons 9 and 20. Correlations between gene expression at mutations and clinical characteristics of gender, age, histological type, degree of differentiation, smoking status, immunohistochemical (IHC) evaluation of TTF-1, TNM staging, and discrete age ("nage") were examined. Significant associations were observed between IHC staining for TTF-1 and histological type (P = 0.00001) and with BRAC1, TYMS, RRM1, and TUBB3 expression (P = 0.0187, 0.0051, 0.024, and 0.0238, respectively). Significant cross-correlations were observed between TYMS, BRAC1, TOP2A, STMN1, TUBB3, and RRM1 expression (P < 0.05), but not between EGFR exon 21, KRAS exon 2, and PIK3CA exon 9 expression and any other mutation expression (P > 0.05). Relationships between clinical characteristics and oncogene expression in NSCLC, particularly those of TTF-1 level and smoking status, may be useful indicators of prognosis and development of anti-cancer drug resistance.

  14. Cinnamic Acid Derivatives as Inhibitors of Oncogenic Protein Kinases--Structure, Mechanisms and Biomedical Effects.

    PubMed

    Mielecki, Marcin; Lesyng, Bogdan

    2016-01-01

    Cinnamic acid belongs to phenolic-acid class of polyphenols, one of the most abundant plant secondary metabolites. These substances are widely studied because of plethora of their biological activities. In particular, their inhibition of protein kinases contributes to the pleiotropic effects in the cell. Protein kinases are essential in controlling cell signaling networks. Selective targeting of oncogenic protein kinases increases clinical anticancer efficacy. Cinnamic acid and related compounds have inspired researchers in the design of numerous synthetic and semisynthetic inhibitors of oncogenic protein kinases for the past three decades. Interest in cinnamoyl-scaffold-containing compounds revived in recent years, which was stimulated by modern drug design and discovery methodologies such as in vitro and in silico HTS. This review presents cinnamic acid derivatives and analogs for which direct inhibition of protein kinases was identified. We also summarize significance of the above protein kinase families - validated or promising targets for anticancer therapies. The inhibition mode may vary from ATP-competitive, through bisubstrate-competitive and mixedcompetitive, to non-competitive one. Kinase selectivity is often correlated with subtle chemical modifications, and may also be steered by an additional non-cinnamoyl fragment of the inhibitor. Specific cinnamic acid congeners may synergize their effects in the cell by a wider range of activities, like suppression of additional enzymes, e.g. deubiquitinases, influencing the same signaling pathways (e.g. JAK2/STAT). Cinnamic acid, due to its biological and physicochemical properties, provides nature-inspired ideas leading to novel inhibitors of oncogenic protein kinases and related enzymes, capable to target a variety of cancer cells.

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

    PubMed Central

    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

  16. Mas Oncogene Signaling and Transformation Require the Small GTP-Binding Protein Rac

    PubMed Central

    Zohn, Irene E.; Symons, Marc; Chrzanowska-Wodnicka, Magdalena; Westwick, John K.; Der, Channing J.

    1998-01-01

    The Mas oncogene encodes a novel G-protein-coupled receptor that was identified originally as a transforming protein when overexpressed in NIH 3T3 cells. The mechanism and signaling pathways that mediate Mas transformation have not been determined. We observed that the foci of transformed NIH 3T3 cells caused by Mas were similar to those caused by activated Rho and Rac proteins. Therefore, we determined if Mas signaling and transformation are mediated through activation of a specific Rho family protein. First, we observed that, like activated Rac1, Mas cooperated with activated Raf and caused synergistic transformation of NIH 3T3 cells. Second, both Mas- and Rac1-transformed NIH 3T3 cells retained actin stress fibers and showed enhanced membrane ruffling. Third, like Rac, Mas induced lamellipodium formation in porcine aortic endothelial cells. Fourth, Mas and Rac1 strongly activated the JNK and p38, but not ERK, mitogen-activated protein kinases. Fifth, Mas and Rac1 stimulated transcription from common DNA promoter elements: NF-κB, serum response factor (SRF), Jun/ATF-2, and the cyclin D1 promoter. Finally, Mas transformation and some of Mas signaling (SRF and cyclin D1 but not NF-κB activation) were blocked by dominant negative Rac1. Taken together, these observations suggest that Mas transformation is mediated in part by activation of Rac-dependent signaling pathways. Thus, Rho family proteins are common mediators of transformation by a diverse variety of oncogene proteins that include Ras, Dbl family, and G-protein-coupled oncogene proteins. PMID:9488437

  17. Complete surgical resection of lung tumor decreases exhalation of mutated KRAS oncogene.

    PubMed

    Kordiak, Jacek; Szemraj, Janusz; Hamara, Katarzyna; Bialasiewicz, Piotr; Nowak, Dariusz

    2012-09-01

    Exhaled breath condensate (EBC) contains extracellular DNA that may originate from pathological lesions of the respiratory tract and can be a genetic marker of pulmonary malignancy. We tested whether complete surgical excision of lung cancer will decrease exhalation of mutated KRAS oncogene. Fifty seven patients with clinical diagnosis of lung cancer and detectable KRAS mutations in pre-surgery EBC-DNA were qualified for surgical treatment. Point mutations at codon 12 of KRAS oncogene were detected using mutant-enriched PCR technique in DNA from pre-surgery blood, EBC collected before, 7 and 30 days after surgery and from specimens of resected tumor and normal pulmonary parenchyma. The ratio of mutated to wild type KRAS DNA (R mut/wild KRAS) was calculated for each specimen after electrophoresis and densitometry of the final amplification and digestion product. In 46 patients non-small cell lung cancer (NSCLC) and in 11 benign lesion (BL) were confirmed. All blood and tumor specimens were positive for KRAS mutations, while 41 specimens of normal pulmonary parenchyma were negative. In NSCLC patients pre-surgery EBC R mut/wild KRAS of 0.20 ± 0.03 decreased by 1.3- and 3.7-times (p < 0.001) at 7th and 30th day and 10 EBC specimens at day 30th became negative. The highest R mut/wild KRAS was found in NSCLC specimens - 1.36 ± 0.29 while the lowest in pulmonary parenchyma - 0.02 ± 0.03 (p < 0.001). R mut/wild KRAS in EBC did not correlate with the blood and cancer ratios. Determination of mutated KRAS oncogene in EBC can be potentially helpful in the follow-up of surgical treatment of pulmonary malignancy. PMID:22795503

  18. RNAi-mediated oncogene silencing confers resistance to crown gall tumorigenesis.

    PubMed

    Escobar, M A; Civerolo, E L; Summerfelt, K R; Dandekar, A M

    2001-11-01

    Crown gall disease, caused by the soil bacterium Agrobacterium tumefaciens, results in significant economic losses in perennial crops worldwide. A. tumefaciens is one of the few organisms with a well characterized horizontal gene transfer system, possessing a suite of oncogenes that, when integrated into the plant genome, orchestrate de novo auxin and cytokinin biosynthesis to generate tumors. Specifically, the iaaM and ipt oncogenes, which show approximately 90% DNA sequence identity across studied A. tumefaciens strains, are required for tumor formation. By expressing two self-complementary RNA constructions designed to initiate RNA interference (RNAi) of iaaM and ipt, we generated transgenic Arabidopsis thaliana and Lycopersicon esculentum plants that are highly resistant to crown gall disease development. In in vitro root inoculation bioassays with two biovar I strains of A. tumefaciens, transgenic Arabidopsis lines averaged 0.0-1.5% tumorigenesis, whereas wild-type controls averaged 97.5% tumorigenesis. Similarly, several transformed tomato lines that were challenged by stem inoculation with three biovar I strains, one biovar II strain, and one biovar III strain of A. tumefaciens displayed between 0.0% and 24.2% tumorigenesis, whereas controls averaged 100% tumorigenesis. This mechanism of resistance, which is based on mRNA sequence homology rather than the highly specific receptor-ligand binding interactions characteristic of traditional plant resistance genes, should be highly durable. If successful and durable under field conditions, RNAi-mediated oncogene silencing may find broad applicability in the improvement of tree crop and ornamental rootstocks. PMID:11687652

  19. Governance of science at the National Cancer Institute: perceptions and opportunities in oncogene research.

    PubMed

    Fischinger, P J; DeVita, V T

    1984-10-01

    Insights from various areas of carcinogenesis can now be blended into cohesive and molecular hypotheses testable at a clinical level. One can now define new areas such as biochemical epidemiology. Whereas previously one thought of identifying individuals at high risk for cancer due to life-style or occupation, one can now propose to identify the susceptible individual at the molecular level for some cancers. Theoretically, if past exposure to carcinogens were significant, we may now be able to measure the exact sites of attack and damage in cellular DNA. We now have oncogenes as the probable targets. Treatment potential with highly specific molecular tools should not be far behind. As often cited before, the first priority of the NCl has always been basic research. The present excitement in the area of oncogenes has certainly been a shining example of research success. As is always the case in a rapidly moving field, there are optimists and pessimists. There are fears of overpromise and dangers of lack of swift application. NCl's view can be summed up this way. Oncogene research is important if only for its implications in developmental biology. It needs no other reason for support or excitement. It also will be important to our understanding of cancer; how important, we do not yet know. We believe it will lead to practical applications in diagnosis, prevention, and treatment; how practical and how soon remain unknowns. By definition then, we are clearly optimists, for which no apologies are offered. The danger of overpromise, it seems to these authors, is exceeded by the risk of failure to pursue and apply one of the most exciting areas of research that brings molecular biology to the crowded bedside of the cancer patient. A good dose of optimism seems about right to make a little room. PMID:6467222

  20. A Mouse Strain Defective in Both T Cells and NK Cells Has Enhanced Sensitivity to Tumor Induction by Plasmid DNA Expressing Both Activated H-Ras and c-Myc

    PubMed Central

    Sheng-Fowler, Li; Tu, Wei; Fu, Haiqing; Murata, Haruhiko; Lanning, Lynda; Foseh, Gideon; Macauley, Juliete; Blair, Donald; Hughes, Stephen H.; Coffin, John M.; Lewis, Andrew M.; Peden, Keith

    2014-01-01

    As part of safety studies to evaluate the risk of residual cellular DNA in vaccines manufactured in tumorigenic cells, we have been developing in vivo assays to detect and quantify the oncogenic activity of DNA. We generated a plasmid expressing both an activated human H-ras gene and murine c-myc gene and showed that 1 µg of this plasmid, pMSV-T24-H-ras/MSV-c-myc, was capable of inducing tumors in newborn NIH Swiss mice. However, to be able to detect the oncogenicity of dominant activated oncogenes in cellular DNA, a more sensitive system was needed. In this paper, we demonstrate that the newborn CD3 epsilon transgenic mouse, which is defective in both T-cell and NK-cell functions, can detect the oncogenic activity of 25 ng of the circular form of pMSV-T24-H-ras/MSV-c-myc. When this plasmid was inoculated as linear DNA, amounts of DNA as low as 800 pg were capable of inducing tumors. Animals were found that had multiple tumors, and these tumors were independent and likely clonal. These results demonstrate that the newborn CD3 epsilon mouse is highly sensitive for the detection of oncogenic activity of DNA. To determine whether it can detect the oncogenic activity of cellular DNA derived from four human tumor-cell lines (HeLa, A549, HT-1080, and CEM), DNA (100 µg) was inoculated into newborn CD3 epsilon mice both in the presence of 1 µg of linear pMSV-T24-H-ras/MSV-c-myc as positive control and in its absence. While tumors were induced in 100% of mice with the positive-control plasmid, no tumors were induced in mice receiving any of the tumor DNAs alone. These results demonstrate that detection of oncogenes in cellular DNA derived from four human tumor-derived cell lines in this mouse system was not possible; the results also show the importance of including a positive-control plasmid to detect inhibitory effects of the cellular DNA. PMID:25302710

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

    PubMed

    Doggett, Karen; Turkel, Nezaket; Willoughby, Lee F; Ellul, Jason; Murray, Michael J; Richardson, Helena E; Brumby, Anthony M

    2015-01-01

    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 EMT

  2. Regulation of oncogene expression in T-DNA-transformed host plant cells.

    PubMed

    Zhang, Yi; Lee, Chil-Woo; Wehner, Nora; Imdahl, Fabian; Svetlana, Veselova; Weiste, Christoph; Dröge-Laser, Wolfgang; Deeken, Rosalia

    2015-01-01

    Virulent Agrobacterium tumefaciens strains integrate their T-DNA into the plant genome where the encoded agrobacterial oncogenes are expressed and cause crown gall disease. Essential for crown gall development are IaaH (indole-3-acetamide hydrolase), IaaM (tryptophan monooxygenase) and Ipt (isopentenyl transferase), which encode enzymes for the biosynthesis of auxin (IaaH, IaaM) and cytokinin (Ipt). Although these oncogenes are well studied as the tumor-inducing principle, nothing is known about the regulation of oncogene expression in plant cells. Our studies show that the intergenic regions (IGRs) between the coding sequences (CDS) of the three oncogenes function as promoters in plant cells. These promoters possess a eukaryotic sequence organization and cis-regulatory elements for the binding of plant transcription factors. WRKY18, WRKY40, WRKY60 and ARF5 were identified as activators of the Ipt promoter whereas IaaH and IaaM is constitutively expressed and no transcription factor further activates their promoters. Consistent with these results, the wrky triple mutant plants in particular, develops smaller crown galls than wild-type and exhibits a reduced Ipt transcription, despite the presence of an intact ARF5 gene. WRKY40 and WRKY60 gene expression is induced by A. tumefaciens within a few hours whereas the ARF5 gene is transcribed later during crown gall development. The WRKY proteins interact with ARF5 in the plant nucleus, but only WRKY40 together with ARF5 synergistically boosts the activation of the Ipt promoter in an auxin-dependent manner. From our data, we propose that A. tumefaciens initially induces WRKY40 gene expression as a pathogen defense response of the host cell. The WRKY protein is recruited to induce Ipt expression, which initiates cytokinin-dependent host cell division. With increasing auxin levels triggered by ubiquitous expression of IaaH and IaaM, ARF5 is activated and interacts with WRKY40 to potentiate Ipt expression and balance

  3. pSa causes oncogenic suppression of Agrobacterium by inhibiting VirE2 protein export.

    PubMed

    Lee, L Y; Gelvin, S B; Kado, C I

    1999-01-01

    When coresident with the Ti (tumor-inducing) plasmid, the 21-kDa product of the osa gene of the plasmid pSa can suppress crown gall tumorigenesis incited by Agrobacterium tumefaciens. Neither T-DNA processing nor vir (virulence) gene induction is affected by the presence of osa in the bacterium. We used Arabidopsis thaliana root segments and tobacco leaf discs to demonstrate that Osa inhibits A. tumefaciens from transforming these plants to the stable phenotypes of tumorigenesis, kanamycin resistance, and stable beta-glucuronidase (GUS) expression. When A. tumefaciens contained osa, the lack of expression of transient GUS activity in infected plant tissues, as well as the lack of systemic viral symptoms following agroinfection of Nicotiana benthamiana by tomato mottle virus, suggested that oncogenic suppression by Osa occurs before T-DNA enters the plant nucleus. The extracellular complementation of an A. tumefaciens virE2 mutant (the T-DNA donor strain) by an A. tumefaciens strain lacking T-DNA but containing a wild-type virE2 gene (the VirE2 donor strain) was blocked when osa was present in the VirE2 donor strain, but not when osa was present in the T-DNA donor strain. These data indicate that osa inhibits VirE2 protein, but not T-DNA export from A. tumefaciens. These data further suggest that VirE2 protein and T-DNA are separately exported from the bacterium. The successful infection of Datura stramonium plants and leaf discs of transgenic tobacco plants expressing VirE2 protein by an A. tumefaciens virE2 mutant carrying osa confirmed that oncogenic suppression by osa does not occur by blocking T-DNA transfer. Overexpression of virB9, virB10, and virB11 in A. tumefaciens did not overcome oncogenic suppression by osa. The finding that the expression of the osa gene by itself, rather than the formation of a conjugal intermediate with pSa, blocks transformation suggests that the mechanism of oncogenic suppression by osa may differ from that of the IncQ plasmid RSF

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

    PubMed Central

    Doggett, Karen; Turkel, Nezaket; Willoughby, Lee F.; Ellul, Jason; Murray, Michael J.; Richardson, Helena E.; Brumby, Anthony M.

    2015-01-01

    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 EMT

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

    NASA Astrophysics Data System (ADS)

    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.

  6. Rapid Detection of high-level oncogene amplifications in ultrasonic surgical aspirations of brain tumors

    PubMed Central

    2012-01-01

    Background Genomic tumor information, such as identification of amplified oncogenes, can be used to plan treatment. The two sources of a brain tumor that are commonly available include formalin-fixed, paraffin-embedded (FFPE) sections from the small diagnostic biopsy and the ultrasonic surgical aspiration that contains the bulk of the tumor. In research centers, frozen tissue of a brain tumor may also be available. This study compared ultrasonic surgical aspiration and FFPE specimens from the same brain tumors for retrieval of DNA and molecular assessment of amplified oncogenes. Methods Surgical aspirations were centrifuged to separate erythrocytes from the tumor cells that predominantly formed large, overlying buffy coats. These were sampled to harvest nuclear pellets for DNA purification. Four glioblastomas, 2 lung carcinoma metastases, and an ependymoma were tested. An inexpensive PCR technique, multiplex ligation-dependent probe amplification (MLPA), quantified 79 oncogenes using 3 kits. Copy number (CN) results were normalized to DNA from non-neoplastic brain (NB) in calculated ratios, [tumor DNA]/[NB DNA]. Bland-Altman and Spearman rank correlative comparisons were determined. Regression analysis identified outliers. Results Purification of DNA from ultrasonic surgical aspirations was rapid (<3 days) versus FFPE (weeks) and yielded greater amounts in 6 of 7 tumors. Gene amplifications up to 15-fold corresponded closely between ultrasonic aspiration and FFPE assays in Bland-Altman analysis. Correlation coefficients ranged from 0.71 to 0.99 using 3 kit assays per tumor. Although normalized CN ratios greater than 2.0 were more numerous in FFPE specimens, some were found only in the ultrasonic surgical aspirations, consistent with tumor heterogeneity. Additionally, CN ratios revealed 9 high-level (≥