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Sample records for expression reveals oncogenic

  1. 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. PMID:25501747

  2. 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

  3. Comprehensive analysis of HPV16 integration in OSCC reveals no significant impact of physical status on viral oncogene and virally disrupted human gene expression.

    PubMed

    Olthof, Nadine C; Speel, Ernst-Jan M; Kolligs, Jutta; Haesevoets, Annick; Henfling, Mieke; Ramaekers, Frans C S; Preuss, Simon F; Drebber, Uta; Wieland, Ulrike; Silling, Steffi; Lam, Wan L; Vucic, Emily A; Kremer, Bernd; Klussmann, Jens-P; Huebbers, Christian U

    2014-01-01

    Infection with high-risk human papillomavirus (HPV) type 16 is an independent risk factor for the development of oropharyngeal squamous cell carcinomas (OSCC). However, it is unclear whether viral integration is an essential hallmark in the carcinogenic process of OSCC and whether HPV integration correlates with the level of viral gene transcription and influences the expression of disrupted host genes. We analyzed 75 patients with OSCC. HPV16-positivity was proven by p16(INK4A) immunohistochemistry, PCR and FISH. Viral integration was examined using DIPS- as well as APOT-PCR. Viral E2, E6 and E7 gene expression levels were quantified by quantitative reverse transcriptase (RT-q)PCR. Expression levels of 7 human genes disrupted by the virus were extracted from mRNA expression profiling data of 32 OSCCs. Viral copy numbers were assessed by qPCR in 73 tumors. We identified 37 HPV16-human fusion products indicating viral integration in 29 (39%) OSCC. In the remaining tumors (61%) only episome-derived PCR products were detected. When comparing OSCC with or without an integration-derived fusion product, we did not find significant differences in the mean RNA expression of viral genes E2, E6 and E7 or the viral copy numbers per cell, nor did the RNA expression of the HPV-disrupted genes differ from either group of OSCC. In conclusion, our data do not support the hypothesis that integration affects the levels of viral and/or HPV-disrupted human gene transcripts. Thus constitutive, rather than a high level, of expression of oncogene transcripts appears to be required in HPV-related OSCC. PMID:24586376

  4. 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.

  5. Protein kinase Cι expression and oncogenic signaling mechanisms in cancer.

    PubMed

    Murray, Nicole R; Kalari, Krishna R; Fields, Alan P

    2011-04-01

    Accumulating evidence demonstrates that PKCι is an oncogene and prognostic marker that is frequently targeted for genetic alteration in many major forms of human cancer. Functional data demonstrate that PKCι is required for the transformed phenotype of lung, pancreatic, ovarian, prostate, colon, and brain cancer cells. Future studies will be required to determine whether PKCι is also an oncogene in the many other cancer types that also overexpress PKCι. Studies of PKCι using genetically defined models of tumorigenesis have revealed a critical role for PKCι in multiple stages of tumorigenesis, including tumor initiation, progression, and metastasis. Recent studies in a genetic model of lung adenocarcinoma suggest a role for PKCι in transformation of lung cancer stem cells. These studies have important implications for the therapeutic use of aurothiomalate (ATM), a highly selective PKCι signaling inhibitor currently undergoing clinical evaluation. Significant progress has been made in determining the molecular mechanisms by which PKCι drives the transformed phenotype, particularly the central role played by the oncogenic PKCι-Par6 complex in transformed growth and invasion, and of several PKCι-dependent survival pathways in chemo-resistance. Future studies will be required to determine the composition and dynamics of the PKCι-Par6 complex, and the mechanisms by which oncogenic signaling through this complex is regulated. Likewise, a better understanding of the critical downstream effectors of PKCι in various human tumor types holds promise for identifying novel prognostic and surrogate markers of oncogenic PKCι activity that may be clinically useful in ongoing clinical trials of ATM. PMID:20945390

  6. Stromal control of oncogenic traits expressed in response to the overexpression of GLI2, a pleiotropic oncogene.

    PubMed

    Snijders, A M; Huey, B; Connelly, S T; Roy, R; Jordan, R C K; Schmidt, B L; Albertson, D G

    2009-02-01

    Hedgehog signaling is often activated in tumors, yet it remains unclear how GLI2, a transcription factor activated by this pathway, acts as an oncogene. We show that GLI2 is a pleiotropic oncogene. The overexpression induces genomic instability and blocks differentiation, likely mediated in part by enhanced expression of the stem cell gene SOX2. GLI2 also induces transforming growth factor (TGF)B1-dependent transdifferentiation of foreskin and tongue, but not gingival fibroblasts into myofibroblasts, creating an environment permissive for invasion by keratinocytes, which are in various stages of differentiation having downregulated GLI2. Thus, upregulated GLI2 expression is sufficient to induce a number of the acquired characteristics of tumor cells; however, the stroma, in a tissue-specific manner, determines whether certain GLI2 oncogenic traits are expressed. PMID:19015636

  7. 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. PMID:25944692

  8. HER-2/neu oncogene expression and proliferation in breast cancers.

    PubMed Central

    Bacus, S. S.; Ruby, S. G.; Weinberg, D. S.; Chin, D.; Ortiz, R.; Bacus, J. W.

    1990-01-01

    Amplification of the HER-2/neu proto-oncogene in breast cancer has been reported to correlate with poor patient prognosis. The proliferation, or growth fraction, of cells has also been shown to be of prognostic importance in breast cancer. A study was conducted to evaluate the correlation between HER-2/neu gene expression and proliferation in breast cancer. Quantitative immunohistochemical methods for the detection of the HER-2/neu protein expression and for assessing the proliferation fraction on frozen sections of tumor cells were used. The detection of epidermal growth factor receptor (EGFR) along with quantitative DNA ploidy analysis, also was performed on the same breast cancers. The results indicated two subgroups of invasive ductal carcinoma; 1) HER-2/neu overexpressing cases that were negative for EGFR expression and had low proliferation fraction, and a tetraploid DNA pattern (22 cases), and 2) other combinations of HER-2/neu expression and EGFR expression, with a high proliferation fraction and an aneuploid DNA pattern (38 cases). Eight cases of carcinoma in situ were positive for HER-2/neu overexpression and negative for EGFR expression, and had a high proliferation fraction and a tetraploid DNA pattern. Twenty-six cases of low-grade carcinoma exhibited low proliferation and a diploid DNA pattern. Images Figure 1 Figure 2 PMID:1973597

  9. Differential effects on ARF stability by normal vs. oncogenic levels of c-Myc expression

    PubMed Central

    Chen, Delin; Kon, Ning; Zhong, Jiayun; Zhang, Pingzhao; Yu, Long; Gu, Wei

    2013-01-01

    SUMMARY ARF suppresses aberrant cell growth upon c-Myc overexpression through activating p53 responses. Nevertheless, the precise mechanism by which ARF specifically, restrains the oncogenic potential of c-Myc without affecting its normal physiological function is not well understood. Here, we show that low levels of c-Myc expression stimulate cell proliferation whereas high levels inhibit through activating the ARF-p53 response. Although the mRNA levels of ARF are induced under both scenarios, the accumulation of ARF protein occurs only when ULF-mediated degradation of ARF is inhibited by c-Myc overexpression. Moreover, the levels of ARF are reduced through ULF-mediated ubiquitination upon DNA damage. Blocking ARF degradation by c-Myc overexpression dramatically stimulates the apoptotic responses. Our study reveals that ARF stability control is crucial for differentiating normal (low) vs. oncogenic (high) levels of c-Myc expression and suggests that differential effects on ULF- mediated ARF ubiquitination by c-Myc levels act as a barrier in oncogene-induced stress responses. PMID:23747016

  10. The oncogenic transcription factor c-Jun regulates glutaminase expression and sensitizes cells to glutaminase-targeted therapy

    PubMed Central

    Lukey, Michael J.; Greene, Kai Su; Erickson, Jon W.; Wilson, Kristin F.; Cerione, Richard A.

    2016-01-01

    Many transformed cells exhibit altered glucose metabolism and increased utilization of glutamine for anabolic and bioenergetic processes. These metabolic adaptations, which accompany tumorigenesis, are driven by oncogenic signals. Here we report that the transcription factor c-Jun, product of the proto-oncogene JUN, is a key regulator of mitochondrial glutaminase (GLS) levels. Activation of c-Jun downstream of oncogenic Rho GTPase signalling leads to elevated GLS gene expression and glutaminase activity. In human breast cancer cells, GLS protein levels and sensitivity to GLS inhibition correlate strongly with c-Jun levels. We show that c-Jun directly binds to the GLS promoter region, and is sufficient to increase gene expression. Furthermore, ectopic overexpression of c-Jun renders breast cancer cells dependent on GLS activity. These findings reveal a role for c-Jun as a driver of cancer cell metabolic reprogramming, and suggest that cancers overexpressing JUN may be especially sensitive to GLS-targeted therapies. PMID:27089238

  11. Systematic RNA interference reveals that oncogenic KRAS-driven cancers require TBK1.

    PubMed

    Barbie, David A; Tamayo, Pablo; Boehm, Jesse S; Kim, So Young; Moody, Susan E; Dunn, Ian F; Schinzel, Anna C; Sandy, Peter; Meylan, Etienne; Scholl, Claudia; Fröhling, Stefan; Chan, Edmond M; Sos, Martin L; Michel, Kathrin; Mermel, Craig; Silver, Serena J; Weir, Barbara A; Reiling, Jan H; Sheng, Qing; Gupta, Piyush B; Wadlow, Raymond C; Le, Hanh; Hoersch, Sebastian; Wittner, Ben S; Ramaswamy, Sridhar; Livingston, David M; Sabatini, David M; Meyerson, Matthew; Thomas, Roman K; Lander, Eric S; Mesirov, Jill P; Root, David E; Gilliland, D Gary; Jacks, Tyler; Hahn, William C

    2009-11-01

    The proto-oncogene KRAS is mutated in a wide array of human cancers, most of which are aggressive and respond poorly to standard therapies. Although the identification of specific oncogenes has led to the development of clinically effective, molecularly targeted therapies in some cases, KRAS has remained refractory to this approach. A complementary strategy for targeting KRAS is to identify gene products that, when inhibited, result in cell death only in the presence of an oncogenic allele. Here we have used systematic RNA interference to detect synthetic lethal partners of oncogenic KRAS and found that the non-canonical IkappaB kinase TBK1 was selectively essential in cells that contain mutant KRAS. Suppression of TBK1 induced apoptosis specifically in human cancer cell lines that depend on oncogenic KRAS expression. In these cells, TBK1 activated NF-kappaB anti-apoptotic signals involving c-Rel and BCL-XL (also known as BCL2L1) that were essential for survival, providing mechanistic insights into this synthetic lethal interaction. These observations indicate that TBK1 and NF-kappaB signalling are essential in KRAS mutant tumours, and establish a general approach for the rational identification of co-dependent pathways in cancer. PMID:19847166

  12. Pervasive transcription read-through promotes aberrant expression of oncogenes and RNA chimeras in renal carcinoma

    PubMed Central

    Grosso, Ana R; Leite, Ana P; Carvalho, Sílvia; Matos, Mafalda R; Martins, Filipa B; Vítor, Alexandra C; Desterro, Joana MP; Carmo-Fonseca, Maria; de Almeida, Sérgio F

    2015-01-01

    Aberrant expression of cancer genes and non-canonical RNA species is a hallmark of cancer. However, the mechanisms driving such atypical gene expression programs are incompletely understood. Here, our transcriptional profiling of a cohort of 50 primary clear cell renal cell carcinoma (ccRCC) samples from The Cancer Genome Atlas (TCGA) reveals that transcription read-through beyond the termination site is a source of transcriptome diversity in cancer cells. Amongst the genes most frequently mutated in ccRCC, we identified SETD2 inactivation as a potent enhancer of transcription read-through. We further show that invasion of neighbouring genes and generation of RNA chimeras are functional outcomes of transcription read-through. We identified the BCL2 oncogene as one of such invaded genes and detected a novel chimera, the CTSC-RAB38, in 20% of ccRCC samples. Collectively, our data highlight a novel link between transcription read-through and aberrant expression of oncogenes and chimeric transcripts that is prevalent in cancer. DOI: http://dx.doi.org/10.7554/eLife.09214.001 PMID:26575290

  13. Regulatory mechanisms, expression levels and proliferation effects of the FUS-DDIT3 fusion oncogene in liposarcoma.

    PubMed

    Åman, Pierre; Dolatabadi, Soheila; Svec, David; Jonasson, Emma; Safavi, Setareh; Andersson, Daniel; Grundevik, Pernilla; Thomsen, Christer; Ståhlberg, Anders

    2016-04-01

    Fusion oncogenes are among the most common types of oncogene in human cancers. The gene rearrangements result in new combinations of regulatory elements and functional protein domains. Here we studied a subgroup of sarcomas and leukaemias characterized by the FET (FUS, EWSR1, TAF15) family of fusion oncogenes, including FUS-DDIT3 in myxoid liposarcoma (MLS). We investigated the regulatory mechanisms, expression levels and effects of FUS-DDIT3 in detail. FUS-DDIT3 showed a lower expression than normal FUS at both the mRNA and protein levels, and single-cell analysis revealed a lack of correlation between FUS-DDIT3 and FUS expression. FUS-DDIT3 transcription was regulated by the FUS promotor, while its mRNA stability depended on the DDIT3 sequence. FUS-DDIT3 protein stability was regulated by protein interactions through the FUS part, rather than the leucine zipper containing DDIT3 part. In addition, in vitro as well as in vivo FUS-DDIT3 protein expression data displayed highly variable expression levels between individual MLS cells. Combined mRNA and protein analyses at the single-cell level showed that FUS-DDIT3 protein expression was inversely correlated to the expression of cell proliferation-associated genes. We concluded that FUS-DDIT3 is uniquely regulated at the transcriptional as well as the post-translational level and that its expression level is important for MLS tumour development. The FET fusion oncogenes are potentially powerful drug targets and detailed knowledge about their regulation and functions may help in the development of novel treatments. PMID:26865464

  14. The prognostic potential and oncogenic effects of PRR11 expression in hilar cholangiocarcinoma

    PubMed Central

    Qian, Baohua; Yu, Wenlong; Li, Wenfeng; Yu, Guanzhen; Gao, Yong

    2015-01-01

    PRR11 is a newly identified oncogene in lung cancer, yet its role in others tumors remains unclear. Gastrointestinal tissue microarrays were used to evaluate PRR11 expression and its association with clinical outcome was analyzed in patients with hilar cholangiocarcinoma. Overexpression of PRR11 was observed in esophageal, gastric, pancreatic, colorectal, and hilar cholangiocarcinoma. Expression of PRR11 correlated with lymph node metastasis and CA199 level in two HC patient cohorts. After an R0 resection, a high level of PRR11 expression was found to be an independent indicator of recurrence (P = 0.001). In cell culture, PRR11 silencing resulted in decreased cellular proliferation, cell migration, tumor growth of QBC939 cells. Microarray analysis revealed that several genes involved in cell proliferation, cell adhesion, and cell migration were altered in PRR11-knockout cells, including: vimentin (VIM), Ubiquitin carboxyl-terminal hydrolase 1 (UCHL1), early growth response protein (EGR1), and System A amino acid transporter1 (SNAT1). Silencing PRR11 inhibited the expression of UCHL1, EGR1, and SNAT1 proteins, with immunoassays revealing a significant correlation among the levels of these four proteins. These results indicate that PRR11 is an independent prognostic indicator for patients with HC. PMID:25971332

  15. H-ras oncogene expression and angiogenesis in experimental liver cirrhosis.

    PubMed

    Elpek, Gülsüm Özlem; Unal, Betül; Bozova, Sevgi

    2013-01-01

    Background. Proto-oncogenes, particularly ras, may not only affect cell proliferation but also contribute to angiogenesis by influencing both proangiogenic and antiangiogenic mediators. The aim of this study was to investigate whether any relationship exists between ras expression and angiogenesis during diethylnitrosamine- (DEN-) induced experimental liver fibrosis. Materials and Methods. Liver cirrhosis was induced in rats by intraperitoneal injections of DEN. The animals were sacrificed 2 weeks after the last administrations and a hepatectomy was performed. Masson's trichrome staining was used in the evaluation of the extent of liver fibrosis. The vascular density in portal and periportal areas was assessed by determining the count of CD34 labeled vessel sections. For quantitative evaluation of H-ras expression, in each section positive and negative cells were counted. Results. In fibrotic group H-ras expression was higher than that in nonfibrotic group and was more widespread in cirrhotic livers. Friedman's test showed that there was a significant correlation between H-ras expression and VD (P < 0.01). Conclusion. The results of this descriptive study reveal that H-ras expression gradually increases according to the severity of fibrosis and strongly correlates with angiogenesis. PMID:24235967

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Oncogenic KRAS Impairs EGFR Antibodies' Efficiency by C/EBPβ-Dependent Suppression of EGFR Expression12

    PubMed Central

    Derer, Stefanie; Berger, Sven; Schlaeth, Martin; Schneider-Merck, Tanja; Klausz, Katja; Lohse, Stefan; Overdijk, Marije B; Dechant, Michael; Kellner, Christian; Nagelmeier, Iris; Scheel, Andreas H; Lammerts van Bueren, Jeroen J; van de Winkel, Jan GJ; Parren, Paul WHI; Peipp, Matthias; Valerius, Thomas

    2012-01-01

    Oncogenic KRAS mutations in colorectal cancer (CRC) are associated with lack of benefit from epidermal growth factor receptor (EGFR)-directed antibody (Ab) therapy. However, the mechanisms by which constitutively activated KRAS (KRASG12V) impairs effector mechanisms of EGFR-Abs are incompletely understood. Here, we established isogenic cell line models to systematically investigate the impact of KRASG12V on tumor growth in mouse A431 xenograft models as well as on various modes of action triggered by EGFR-Abs in vitro. KRASG12V impaired EGFR-Ab-mediated growth inhibition by stimulating receptor-independent downstream signaling. KRASG12V also rendered tumor cells less responsive to Fc-mediated effector mechanisms of EGFR-Abs—such as complement-dependent cytotoxicity (CDC) and Ab-dependent cell-mediated cytotoxicity (ADCC). Impaired CDC and ADCC activities could be linked to reduced EGFR expression in KRAS-mutated versus wild-type (wt) cells, which was restored by small interfering RNA (siRNA)-mediated knockdown of KRAS4b. Immunohistochemistry experiments also revealed lower EGFR expression in KRAS-mutated versus KRAS-wt harboring CRC samples. Analyses of potential mechanisms by which KRASG12V downregulated EGFR expression demonstrated significantly decreased activity of six distinct transcription factors. Additional experiments suggested the CCAAT/enhancer-binding protein (C/EBP) family to be implicated in the regulation of EGFR promoter activity in KRAS-mutated tumor cells by suppressing EGFR transcription through up-regulation of the inhibitory family member C/EBPβ-LIP. Thus, siRNA-mediated knockdown of C/EBPβ led to enhanced EGFR expression and Ab-mediated cytotoxicity against KRAS-mutated cells. Together, these results demonstrate that KRASG12V signaling induced C/EBPβ-dependent suppression of EGFR expression, thereby impairing Fc-mediated effector mechanisms of EGFR-Abs and rendering KRAS-mutated tumor cells less sensitive to these therapeutic agents. PMID

  3. Rho GTPase Transcriptome Analysis Reveals Oncogenic Roles for Rho GTPase-Activating Proteins in Basal-like Breast Cancers.

    PubMed

    Lawson, Campbell D; Fan, Cheng; Mitin, Natalia; Baker, Nicole M; George, Samuel D; Graham, David M; Perou, Charles M; Burridge, Keith; Der, Channing J; Rossman, Kent L

    2016-07-01

    The basal-like breast cancer (BLBC) subtype accounts for a disproportionately high percentage of overall breast cancer mortality. The current therapeutic options for BLBC need improvement; hence, elucidating signaling pathways that drive BLBC growth may identify novel targets for the development of effective therapies. Rho GTPases have previously been implicated in promoting tumor cell proliferation and metastasis. These proteins are inactivated by Rho-selective GTPase-activating proteins (RhoGAP), which have generally been presumed to act as tumor suppressors. Surprisingly, RNA-Seq analysis of the Rho GTPase signaling transcriptome revealed high expression of several RhoGAP genes in BLBC tumors, raising the possibility that these genes may be oncogenic. To evaluate this, we examined the roles of two of these RhoGAPs, ArhGAP11A (also known as MP-GAP) and RacGAP1 (also known as MgcRacGAP), in promoting BLBC. Both proteins were highly expressed in human BLBC cell lines, and knockdown of either gene resulted in significant defects in the proliferation of these cells. Knockdown of ArhGAP11A caused CDKN1B/p27-mediated arrest in the G1 phase of the cell cycle, whereas depletion of RacGAP1 inhibited growth through the combined effects of cytokinesis failure, CDKN1A/p21-mediated RB1 inhibition, and the onset of senescence. Random migration was suppressed or enhanced by the knockdown of ArhGAP11A or RacGAP1, respectively. Cell spreading and levels of GTP-bound RhoA were increased upon depletion of either RhoGAP. We have established that, via the suppression of RhoA, ArhGAP11A and RacGAP1 are both critical drivers of BLBC growth, and propose that RhoGAPs can act as oncogenes in cancer. Cancer Res; 76(13); 3826-37. ©2016 AACR. PMID:27216196

  4. 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

  5. Cloning and characterization of the murine homolog of the sno proto-oncogene reveals a novel splice variant

    NASA Technical Reports Server (NTRS)

    Pelzer, T.; Lyons, G. E.; Kim, S.; Moreadith, R. W.; Blomqvist, C. G. (Principal Investigator)

    1996-01-01

    The cellular function(s) of the SNO protein remain undefined. To gain a better understanding of possible developmental roles of this cellular proto-oncogene, we have cloned two murine sno cDNAs and have investigated their expression patterns in embryonic and postnatal tissues. A single major transcript of 7.5 kb is detected in multiple tissues by Northern blot. However, reverse transcriptase polymerase chain reaction (RT-PCR) and RNAse protection assays revealed a novel splice variant in every tissue examined. Two isoforms, termed sno N and sno-dE3 (dE3, deletion within exon 3), were identified. The sno-dE3 isoform employs a novel 5' splice site located within the coding region of the third exon and deletes potential kinase recognition motifs. Transcripts of both sno isoforms accumulate ubiquitously but are most abundant in the developing central nervous system. The in situ hybridization patterns of sno expression during murine development suggest potential roles in tissues with a high degree of cellular proliferation. Expression in terminally differentiated tissues such as muscle and neurons indicates that SNO may have multiple functional activities.

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

    PubMed Central

    Li, Zhen; Zheng, Weiling; Li, Hankun; Li, Caixia; Gong, Zhiyuan

    2015-01-01

    Previously we have generated inducible liver tumor models by transgenic expression of Myc or xmrk (activated EGFR homolog) oncogenes in zebrafish. To investigate the interaction of the two oncogenes, we crossed the two transgenic lines and observed more severe and faster hepatocarcinogenesis in Myc/xmrk double transgenic zebrafish than either single transgenic fish. RNA-Seq analyses revealed distinct changes in many molecular pathways among the three types of liver tumors. In particular, we found dramatic alteration of cancer metabolism based on the uniquely enriched pathways in the Myc/xmrk tumors. Critical glycolytic genes including hk2, pkm and ldha were significantly up-regulated in Myc/xmrk tumors but not in either single oncogene-induced tumors, suggesting a potential Warburg effect. In RT-qPCR analyses, the specific pkm2 isoformin Warburg effect was found to be highly enriched in the Myc/xmrk tumors but not in Myc or xmrk tumors, consistent with the observations in many human cancers with Warburg effect. Moreover, the splicing factor genes (hnrnpa1, ptbp1a, ptbp1b and sfrs3b) responsible for generating the pkm isoform were also greatly up-regulated in the Myc/xmrk tumors. As Pkm2 isoform is generally inactive and causes incomplete glycolysis to favor anabolism and tumor growth, by treatment with a Pkm2-specific activator, TEPP-46, we further demonstrated that activation of Pkm2 suppressed the growth of oncogenic liver as well as proliferation of liver cells. Collectively, our Myc/xmrk zebrafish model suggests synergetic effect of EGFR and MYC in triggering Warburg effect in the HCC formation and may provide a promising in vivo model for Warburg effect. PMID:26147004

  7. Proto-oncogene expression in porcine myocardium subjected to ischemia and reperfusion.

    PubMed

    Brand, T; Sharma, H S; Fleischmann, K E; Duncker, D J; McFalls, E O; Verdouw, P D; Schaper, W

    1992-12-01

    The molecular basis of myocardial adaptation to ischemia and reperfusion is poorly understood. It is thought that nuclear proto-oncogenes act as third messengers, converting cytoplasmic signal transduction into long-term changes of gene expression. We studied the expression of six nuclear proto-oncogenes (Egr-1, c-fos, fosB, c-jun, junB, and c-myc) in myocardium subjected to ischemia and reperfusion in anesthetized pigs. Stunning was achieved by two 10-minute left anterior descending coronary artery occlusions separated by 30 minutes of reperfusion. Hearts were excised after the first occlusion, after the first reperfusion, and at 30, 120, 150, and 210 minutes of reperfusion after the second occlusion. Total RNA was prepared from stunned as well as normally perfused myocardial tissue and subjected to Northern blotting. The response of the six nuclear proto-oncogenes varied.fosB gene expression was never detected. The c-myc gene was expressed, but its level was unchanged by ischemia. c-jun expression was slightly increased by ischemia (3.1 +/- 0.6-fold). The c-fos, Egr-1, and junB genes were highly induced, being fivefold to sevenfold higher in experimental than in control tissue. In three animals pretreated with the beta 1-antagonist metoprolol and then subjected to the above experimental protocol, the induction of proto-oncogenes was similar to that in nonblocked controls. Our results show that the myocardial adaptive response to ischemic stress includes the induction of at least four transcription factors that may be further operative in repair processes and angiogenesis. PMID:1385005

  8. 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.

  9. 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.

  10. Loss of oncogenic ras expression does not correlate with loss of tumorigenicity in human cells.

    PubMed Central

    Plattner, R; Anderson, M J; Sato, K Y; Fasching, C L; Der, C J; Stanbridge, E J

    1996-01-01

    ras oncogenes are mutated in at variety of human tumors, which suggests that they play an important role in human carcinogenesis. To determine whether continued oncogenic ras expression is necessary to maintain the malignant phenotype, we studied the human fibrosarcoma cell line, HT1080, which contains one mutated and one wild-type N-ras allele. We isolated a variant of this cell line that no longer contained the mutated copy of the N-ras gene. Loss of mutant N-ras resulted in cells that displayed a less transformed phenotype characterized by a flat morphology, decreased growth rate, organized actin stress fibers, and loss of anchorage-independent growth. The transformed phenotype was restored following reintroduction of mutant N-ras. Although loss of the oncogenic N-ras drastically affected in vitro growth parameters, the variant remained tumorigenic in nude mice indicating that mutated N-ras expression is not necessary for maintenance of the tumorigenic phenotype. We confirmed this latter observation in colon carcinoma cell lines that have lost activated K-ras expression via targeted knockout of the mutant K-ras gene. Images Fig. 1 Fig. 2 Fig. 3 Fig. 5 PMID:8692875

  11. Long noncoding RNA XIST acts as an oncogene in non-small cell lung cancer by epigenetically repressing KLF2 expression.

    PubMed

    Fang, Jing; Sun, Cheng-Cao; Gong, Cheng

    2016-09-16

    Recently, long noncoding RNAs (lncRNAs) have been identified as critical regulators in numerous types of cancers, including non-small cell lung cancer (NSCLC). X inactivate-specific transcript (XIST) has been found to be up-regulated and acts as an oncogene in gastric cancer and hepatocellular carcinoma, but little is known about its expression pattern, biological function and underlying mechanism in NSCLC. Here, we identified XIST as an oncogenic lncRNA by driving tumorigenesis in NSCLC. We found that XIST is over-expressed in NSCLC, and its increased level is associated with shorter survival and poorer prognosis. Knockdown of XIST impaired NSCLC cells proliferation, migration and invasion in vitro, and repressed the tumorigenicity of NSCLC cells in vivo. Mechanistically, RNA immune-precipitation (RIP) and RNA pull-down experiment demonstrated that XIST could simultaneously interact with EZH2 to suppress transcription of its potential target KLF2. Additionally, rescue experiments revealed that XIST's oncogenic functions were partly depending on silencing KLF2 expression. Collectively, our findings expound how XIST over-expression endows an oncogenic function in NSCLC. PMID:27501756

  12. The proto-oncogene c-ets is preferentially expressed in lymphoid cells.

    PubMed Central

    Chen, J H

    1985-01-01

    The transforming sequences of the avian acute leukemia virus, E26, contain two distinct oncogenes, v-mybE and v-ets, fused together. By using a probe containing v-ets sequences, polyadenylated transcripts of the c-ets proto-oncogene were detected in avian tissues; they included a major 7.0-kilobase and a minor 2.0-kilobase species. These c-ets mRNAs were detected at high levels only in lymphoid organs and in avian T and B lymphoid cell lines. A similar pattern of c-ets transcription was observed in human hematopoietic cell lines, with transcripts detected in lymphoid B and T cells but not in erythroid or myeloid cells. The E26 oncogene was inserted into an inducible expression vector, and a 90-kilodalton protein (bp90) was produced in bacteria. Rabbit antisera raised to purified bp90 precipitated P135gag-mybE-ets, the v-mybE-ets polyprotein expressed in E26-transformed cells, and also reacted with p50v-mybA, the transforming protein of the avian myeloblastosis virus. Antiserum to bp90 was absorbed with a bacterially synthesized v-mybA protein to remove anti-myb activity. The absorbed anti-bp90 serum retained the ability to immunoprecipitate P135gag-mybE-ets from E26-transformed cells and specifically reacted with a 56-kilodalton polypeptide (p56) detected in chicken lymphoid organs and in T and B lymphocytes of both avian and human origin. The data suggest that p56 is a translational product of the c-ets proto-oncogene and imply that p56 may be involved in regulating the growth of lymphoid cells. Images PMID:3018492

  13. Increased H+ efflux is sufficient to induce dysplasia and necessary for viability with oncogene expression

    PubMed Central

    Grillo-Hill, Bree K; Choi, Changhoon; Jimenez-Vidal, Maite; Barber, Diane L

    2015-01-01

    Intracellular pH (pHi) dynamics is increasingly recognized as an important regulator of a range of normal and pathological cell behaviors. Notably, increased pHi is now acknowledged as a conserved characteristic of cancers and in cell models is confirmed to increase proliferation and migration as well as limit apoptosis. However, the significance of increased pHi for cancer in vivo remains unresolved. Using Drosophila melanogaster, we show that increased pHi is sufficient to induce dysplasia in the absence of other transforming cues and potentiates growth and invasion with oncogenic Ras. Using a genetically encoded biosensor we also confirm increased pHi in situ. Moreover, in Drosophila models and clonal human mammary cells we show that limiting H+ efflux with oncogenic Raf or Ras induces acidosis and synthetic lethality. Further, we show lethality in invasive primary tumor cell lines with inhibiting H+ efflux. Synthetic lethality with reduced H+ efflux and activated oncogene expression could be exploited therapeutically to restrain cancer progression while limiting off-target effects. DOI: http://dx.doi.org/10.7554/eLife.03270.001 PMID:25793441

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

    SciTech Connect

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

    2008-10-24

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

  15. Unexpected functional similarities between gatekeeper tumour suppressor genes and proto-oncogenes revealed by systems biology.

    PubMed

    Zhao, Yongzhong; Epstein, Richard J

    2011-05-01

    Familial tumor suppressor genes comprise two subgroups: caretaker genes (CTs) that repair DNA, and gatekeeper genes (GKs) that trigger cell death. Since GKs may also induce cell cycle delay and thus enhance cell survival by facilitating DNA repair, we hypothesized that the prosurvival phenotype of GKs could be selected during cancer progression, and we used a multivariable systems biology approach to test this. We performed multidimensional data analysis, non-negative matrix factorization and logistic regression to compare the features of GKs with those of their putative antagonists, the proto-oncogenes (POs), as well as with control groups of CTs and functionally unrelated congenital heart disease genes (HDs). GKs and POs closely resemble each other, but not CTs or HDs, in terms of gene structure (P<0.001), expression level and breadth (P<0.01), DNA methylation signature (P<0.001) and evolutionary rate (P<0.001). The similar selection pressures and epigenetic trajectories of GKs and POs so implied suggest a common functional attribute that is strongly negatively selected-that is, a shared phenotype that enhances cell survival. The counterintuitive finding of similar evolutionary pressures affecting GKs and POs raises an intriguing possibility: namely, that cancer microevolution is accelerated by an epistatic cascade in which upstream suppressor gene defects subvert the normal bifunctionality of wild-type GKs by constitutively shifting the phenotype away from apoptosis towards survival. If correct, this interpretation would explain the hitherto unexplained phenomenon of frequent wild-type GK (for example, p53) overexpression in tumors. PMID:21368766

  16. Oncogene mutation profiling reveals poor prognosis associated with FGFR1/3 mutation in liposarcoma.

    PubMed

    Li, Chengfang; Shen, Yaoyuan; Ren, Yan; Liu, Wei; Li, Man; Liang, Weihua; Liu, Chunxia; Li, Feng

    2016-09-01

    Liposarcoma (LPS) is one of the most prevalent soft tissue sarcomas. LPS shows a poor response to radiation and chemotherapy. The causes of death in patients with LPS include locally recurrent and metastatic disease. We sought to examine novel gene mutations and pathways in primary and matched recurrent LPSs to identify potential therapeutic targets. We conducted a high-throughput analysis of 238 known mutations in 19 oncogenes using Sequenom MassARRAY technology. Nucleic acids were extracted from 19 primary and recurrent LPS samples, encompassing 9 dedifferentiated LPSs (DDLPS), 9 myxoid/round cell LPSs, and 1 pleomorphic LPS. Mutation screening revealed missense mutations in 21.1% (4/19) of the LPS specimens, including 4 different genes (FGFR1, FGFR3, PIK3CA, and KIT). Based on histologic subtypes, 22.2% DDLPS (2/9) and 22.2% myxoid cell LPS (2/9) contained gene mutations. Specifically, 3 (23.1%) of 13 primary tumors harbored mutations. Furthermore, although gene mutations were identified in 1 (11.1%) of 9 recurrent LPS samples, the difference between the primary and the recurrence was not statistically significant. Analysis of patient survival data indicated that patients harboring FGFR1/3 mutations experienced reduced overall survival (P<.05). Despite the limited number of samples, our findings provide the first evidence of FGFR1/3 mutations in DDLPS, which were associated with poor clinical outcomes. The FGFR pathway may play an important role in the development and progression of DDLPS and warrants further investigation; moreover, PIK3CA mutation is a common event (11.1%) in myxoid cell LPS. PMID:27237367

  17. Expression of BCR-ABL1 oncogene relative to ABL1 gene changes overtime in chronic myeloid leukemia

    SciTech Connect

    Gupta, Manu; Milani, Lili; Hermansson, Monica; Simonsson, Bengt; Markevaern, Berit; Syvaenen, Ann Christine; Barbany, Gisela

    2008-02-15

    Using a quantitative single nucleotide polymorphism (SNP) assay we have investigated the changes in the expression of the BCR-ABL1 oncogene relative to the wild-type ABL1 and BCR alleles in cells from chronic myeloid leukemia (CML) patients not responding to therapy. The results show a progressive increase in the BCR-ABL1 oncogene expression at the expense of decreased expression of the ABL1 allele, not involved in the fusion. No relative changes in the expression of the two BCR alleles were found. These results demonstrate that allele-specific changes in gene expression, with selective, progressive silencing of the wild-type ABL1 allele in favor of the oncogenic BCR-ABL1 allele occur in CML patients with therapy-resistant disease.

  18. 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

  19. STAT5 Outcompetes STAT3 To Regulate the Expression of the Oncogenic Transcriptional Modulator BCL6

    PubMed Central

    Walker, Sarah R.; Nelson, Erik A.; Yeh, Jennifer E.; Pinello, Luca; Yuan, Guo-Cheng

    2013-01-01

    Inappropriate activation of the transcription factors STAT3 and STAT5 has been shown to drive cancer pathogenesis through dysregulation of genes involved in cell survival, growth, and differentiation. Although STAT3 and STAT5 are structurally related, they can have opposite effects on key genes, including BCL6. BCL6, a transcriptional repressor, has been shown to be oncogenic in diffuse large B cell lymphoma. BCL6 also plays an important role in breast cancer pathogenesis, a disease in which STAT3 and STAT5 can be activated individually or concomitantly. To determine the mechanism by which these oncogenic transcription factors regulate BCL6 transcription, we analyzed their effects at the levels of chromatin and gene expression. We found that STAT3 increases expression of BCL6 and enhances recruitment of RNA polymerase II phosphorylated at a site associated with transcriptional initiation. STAT5, in contrast, represses BCL6 expression below basal levels and decreases the association of RNA polymerase II at the gene. Furthermore, the repression mediated by STAT5 is dominant over STAT3-mediated induction. STAT5 exerts this effect by displacing STAT3 from one of the two regulatory regions to which it binds. These findings may underlie the divergent biology of breast cancers containing activated STAT3 alone or in conjunction with activated STAT5. PMID:23716595

  20. Tocopherol Succinate: Modulation of Antioxidant Enzymes and Oncogene Expression, and Hematopoietic Recovery

    SciTech Connect

    Singh, Vijay K.; Parekh, Vaishali I.; Brown, Darren S.; Kao, Tzu-Cheg; Mog, Steven R.

    2011-02-01

    Purpose: A class of naturally occurring isoforms of tocopherol (tocols) was shown to have varying degrees of protection when administered before radiation exposure. We recently demonstrated that {alpha}-tocopherol succinate (TS) is a potential radiation prophylactic agent. Our objective in this study was to further investigate the mechanism of action of TS in mice exposed to {sup 60}Co {gamma}-radiation. Methods and Materials: We evaluated the effects of TS on expression of antioxidant enzymes and oncogenes by quantitative RT-PCR in bone marrow cells of {sup 60}Co {gamma}-irradiated mice. Further, we tested the ability of TS to rescue and repopulate hematopoietic stem cells by analyzing bone marrow cellularity and spleen colony forming unit in spleen of TS-injected and irradiated mice. Results: Our results demonstrate that TS modulated the expression of antioxidant enzymes and inhibited expression of oncogenes in irradiated mice at different time points. TS also increased colony forming unit-spleen numbers and bone marrow cellularity in irradiated mice. Conclusions: Results provide additional support for the observed radioprotective efficacy of TS and insight into mechanisms.

  1. 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

  2. Chromosomal integration of an avian oncogenic herpesvirus reveals telomeric preferences and evidence for lymphoma clonality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease (MD) is a highly contagious neoplastic disease resulting from a cell-associated oncogenic herpesvirus, Marek’s disease virus (MDV) that induces lymphoid tumors in chickens, its natural host. Genomic interactions between virus and host, and their involvement in the process of tumorig...

  3. Kita Driven Expression of Oncogenic HRAS Leads to Early Onset and Highly Penetrant Melanoma in Zebrafish

    PubMed Central

    Santoriello, Cristina; Gennaro, Elisa; Anelli, Viviana; Distel, Martin; Kelly, Amanda; Köster, Reinhard W.; Hurlstone, Adam; Mione, Marina

    2010-01-01

    Background Melanoma is the most aggressive and lethal form of skin cancer. Because of the increasing incidence and high lethality of melanoma, animal models for continuously observing melanoma formation and progression as well as for testing pharmacological agents are needed. Methodology and Principal Findings Using the combinatorial Gal4 –UAS system, we have developed a zebrafish transgenic line that expresses oncogenic HRAS under the kita promoter. Already at 3 days transgenic kita-GFP-RAS larvae show a hyper-pigmentation phenotype as earliest evidence of abnormal melanocyte growth. By 2–4 weeks, masses of transformed melanocytes form in the tail stalk of the majority of kita-GFP-RAS transgenic fish. The adult tumors evident between 1–3 months of age faithfully reproduce the immunological, histological and molecular phenotypes of human melanoma, but on a condensed time-line. Furthermore, they show transplantability, dependence on mitfa expression and do not require additional mutations in tumor suppressors. In contrast to kita expressing melanocyte progenitors that efficiently develop melanoma, mitfa expressing progenitors in a second Gal4-driver line were 4 times less efficient in developing melanoma during the three months observation period. Conclusions and Significance This indicates that zebrafish kita promoter is a powerful tool for driving oncogene expression in the right cells and at the right level to induce early onset melanoma in the presence of tumor suppressors. Thus our zebrafish model provides a link between kita expressing melanocyte progenitors and melanoma and offers the advantage of a larval phenotype suitable for large scale drug and genetic modifier screens. PMID:21170325

  4. Oncogenic BRAFV600E inhibits BIM expression to promote melanoma cell survival

    PubMed Central

    Cartlidge, Robert A.; Thomas, G. R.; Cagnol, Sebastien; Jong, Kimberly A.; Molton, Sarah A.; Finch, Andrew J.; McMahon, Martin

    2016-01-01

    Summary Somatic activating mutations of BRAF are the earliest and most common genetic abnormality detected in the genesis of human melanoma. However, the mechanism(s) by which activated BRAF promotes melanoma cell cycle progression and/or survival remain unclear. Here we demonstrate that expression of BIM, a pro-apoptotic member of the BCL-2 family, is inhibited by BRAF → MEK → ERK signaling in mouse and human melanocytes and in human melanoma cells. Trophic factor deprivation of melanocytes leads to elevated BIM expression. However, re-addition of trophic factors or activation of a conditional form of BRAFV600E leads to rapid inhibition of BIM expression. In both cases, inhibition of BIM expression was dependent on the activity of MEK1/2 and the proteasome. Consistent with these observations, pharmacological inhibition of BRAFV600E or MEK1/2 in human melanoma cells (using PLX4720 and CI-1040 respectively) led to a striking elevation of BIM expression. Re-activation of BRAF → MEK → ERK signaling led to phosphorylation of BIM-EL on serine 69 and its subsequent degradation. Interestingly, endogenous expression of BIM in melanoma cells was insufficient to induce apoptosis unless combined with serum deprivation. Under these circumstances, inhibition of BIM expression by RNA interference provided partial protection from apoptosis. These data suggest that regulation of BIM expression by BRAF → MEK → ERK signaling is one mechanism by which oncogenic BRAFV600E can influence the aberrant physiology of melanoma cells. PMID:18715233

  5. SIRT6 promotes COX-2 expression and acts as an oncogene in skin cancer

    PubMed Central

    Ming, Mei; Han, Weinong; Zhao, Baozhong; Sundaresan, Nagalingam R.; Deng, Chu-Xia; Gupta, Mahesh; He, Yu-Ying

    2014-01-01

    SIRT6 is a SIR2 family member that regulates multiple molecular pathways involved in metabolism, genomic stability and aging. It has been proposed previously that SIRT6 is a tumor suppressor in cancer. Here we challenge this concept by presenting evidence that skin-specific deletion of SIRT6 in the mouse inhibits skin tumorigenesis. SIRT6 promoted expression of COX-2 by repressing AMPK signaling, thereby increasing cell proliferation and survival and in the skin epidermis. SIRT6 expression in skin keratinocytes was increased by exposure to UVB light through activation of the AKT pathway. Clinically, we found that SIRT6 was upregulated in human skin squamous cell carcinoma. Taken together, our results provide evidence that SIRT6 functions an oncogene in the epidermis and suggest greater complexity to its role in epithelial carcinogenesis. PMID:25320180

  6. Oncogenic relevant defensins: expression pattern and proliferation characteristics of human tumor cell lines.

    PubMed

    Winter, Jochen; Kraus, Dominik; Reckenbeil, Jan; Probstmeier, Rainer

    2016-06-01

    The objective of this study was to investigate gene expression levels of oncogenic relevant human defensins and their impact on proliferation rates of 29 cell lines derived from main types of different tumor origins. Differential gene expression analysis of human defensins was performed by real-time PCR experiments. The proliferation rate of tumor cells that had been cultivated in the absence or presence of biologically active peptides was analyzed with a lactate dehydrogenase assay kit. At least one member of the defensin family was expressed in each tumor cell line, whereby α-defensin (DEFA1), DEFA2, or DEFA3 transcripts could be ubiquitously detected. Cell lines of neural origin (glioma, neuroblastoma, and small-cell lung carcinoma) expressed far less human β-defensins (hBDs) in comparison to other tumor types. The expression level of a specific defensin in various cell lines could vary by more than five orders of magnitude. Compensatory mechanisms on the expression levels of the different defensins could not be strictly observed. Only in 3 out of 29 tumor cell lines the proliferation rate was affected after defensin stimulation. The variable appearance of defensins, as well as the cell line-restricted functional activity, argues for the integration of defensins in complex cellular and molecular networks that tolerate rather flexible expression patterns. PMID:26711780

  7. Determination of synthetic lethal interactions in KRAS oncogene-dependent cancer cells reveals novel therapeutic targeting strategies

    PubMed Central

    Steckel, Michael; Molina-Arcas, Miriam; Weigelt, Britta; Marani, Michaela; Warne, Patricia H; Kuznetsov, Hanna; Kelly, Gavin; Saunders, Becky; Howell, Michael; Downward, Julian; Hancock, David C

    2012-01-01

    Oncogenic mutations in RAS genes are very common in human cancer, resulting in cells with well-characterized selective advantages, but also less well-understood vulnerabilities. We have carried out a large-scale loss-of-function screen to identify genes that are required by KRAS-transformed colon cancer cells, but not by derivatives lacking this oncogene. Top-scoring genes were then tested in a larger panel of KRAS mutant and wild-type cancer cells. Cancer cells expressing oncogenic KRAS were found to be highly dependent on the transcription factor GATA2 and the DNA replication initiation regulator CDC6. Extending this analysis using a collection of drugs with known targets, we found that cancer cells with mutant KRAS showed selective addiction to proteasome function, as well as synthetic lethality with topoisomerase inhibition. Combination targeting of these functions caused improved killing of KRAS mutant cells relative to wild-type cells. These observations suggest novel targets and new ways of combining existing therapies for optimal effect in RAS mutant cancers, which are traditionally seen as being highly refractory to therapy. PMID:22613949

  8. 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

  9. Amplification and expression of the c-myc oncogene in human lung cancer cell lines.

    PubMed

    Little, C D; Nau, M M; Carney, D N; Gazdar, A F; Minna, J D

    Genetic changes involving the c-myc oncogene have been observed in human tumours. In particular, the c-myc gene is translocated in Burkitt's lymphoma and is amplified in the human promyelocytic leukaemia cell line, HL-60, which contains double minute chromosomes (DMs). More recently, an amplified c-myc gene has been positioned on a chromosomal homogeneous staining region (HSR) in a human colon cancer cell line, COLO 320, with neuroendocrine properties. Furthermore, c-myc is expressed in increased amounts in some human tumour lines, and in some cases, human small cell lung cancers (SCLC) contain DMs and HSRs. These findings prompted us to study the c-myc gene and its RNA expression in a series of human lung cancer cell lines. We now report amplification and expression of the c-myc oncogene in a system other than B-cell lymphomas, namely human lung cancer. Of 18 human lung cancer cell lines tested, 8 showed an amplified 12.5-kilobase (kb) EcoRI c-myc DNA band. Of particular interest are five SCLC lines with a high degree of c-myc DNA amplification (20-76-fold) and greatly increased levels of c-myc RNA. All five lines reside in the variant class of SCLC (SCLC-V) characterized by altered morphology, lack of expression of some SCLC-differentiated functions and more malignant behaviour than pure SCLC. Three of the five lines which have been karyotyped also contain DMs or HSRs. The finding of a greatly amplified c-myc gene in all cell lines of the SCLC-V class examined strongly suggests a role for the c-myc gene in the phenotypic conversion and malignant behaviour of human lung cancer. PMID:6646201

  10. Long Noncoding RNA MALAT1 Controls Cell Cycle Progression by Regulating the Expression of Oncogenic Transcription Factor B-MYB

    PubMed Central

    Tripathi, Vidisha; Shen, Zhen; Chakraborty, Arindam; Giri, Sumanprava; Freier, Susan M.; Wu, Xiaolin; Zhang, Yongqing; Gorospe, Myriam; Prasanth, Supriya G.; Lal, Ashish; Prasanth, Kannanganattu V.

    2013-01-01

    The long noncoding MALAT1 RNA is upregulated in cancer tissues and its elevated expression is associated with hyper-proliferation, but the underlying mechanism is poorly understood. We demonstrate that MALAT1 levels are regulated during normal cell cycle progression. Genome-wide transcriptome analyses in normal human diploid fibroblasts reveal that MALAT1 modulates the expression of cell cycle genes and is required for G1/S and mitotic progression. Depletion of MALAT1 leads to activation of p53 and its target genes. The cell cycle defects observed in MALAT1-depleted cells are sensitive to p53 levels, indicating that p53 is a major downstream mediator of MALAT1 activity. Furthermore, MALAT1-depleted cells display reduced expression of B-MYB (Mybl2), an oncogenic transcription factor involved in G2/M progression, due to altered binding of splicing factors on B-MYB pre-mRNA and aberrant alternative splicing. In human cells, MALAT1 promotes cellular proliferation by modulating the expression and/or pre-mRNA processing of cell cycle–regulated transcription factors. These findings provide mechanistic insights on the role of MALAT1 in regulating cellular proliferation. PMID:23555285

  11. 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.

  12. Expression of the Pokemon proto-oncogene in nasopharyngeal carcinoma cell lines and tissues.

    PubMed

    Jiao, Wei; Liu, Fei; Tang, Feng-Zhu; Lan, Jiao; Xiao, Rui-Ping; Chen, Xing-Zhou; Ye, Hui-Lan; Cai, Yong-Lin

    2013-01-01

    To study the differentiated expression of the proto-oncogene Pokemon in nasopharyngeal carcinoma (NPC) cell lines and tissues, mRNA and protein expression levels of CNE1, CNE2, CNE3 and C666-1 were detected separately by reverse transcription polymerase chain reaction (RT-PCR), real-time PCR and Western-blotting. The immortalized nasopharyngeal epithelial cell line NP69 was used as a control. The Pokemon protein expression level in biopsy specimens from chronic rhinitis patients and undifferentiated non keratinizing NPC patients was determined by Western-blotting and arranged from high to low: C666-1>CNE1>CNE2> CNE3>NP69. The Pokemon mRNA expression level was also arranged from high to low: CNE1>CNE2>NP69>C666-1>CNE3. Pokemon expression of NP69 and C666-1 obviously varied from mRNA to protein. The Pokemon protein level of NPC biopsy specimens was obviously higher than in chronic rhinitis. The data suggest that high Pokemon protein expression is closely associated with undifferentiated non-keratinizing NPC and may provide useful information for NPC molecular target therapy. PMID:24377524

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

    SciTech Connect

    Wang, Hongtao; Gao, Peng; Zheng, Jie

    2014-09-05

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

  14. Role of Cdc6 in re-replication in cells expressing human papillomavirus E7 oncogene.

    PubMed

    Fan, Xueli; Zhou, Yunying; Chen, Jason J

    2016-08-01

    The E7 oncoprotein of high-risk human papillomavirus (HPV) types induces DNA re-replication that contributes to carcinogenesis; however, the mechanism is not fully understood. To better understand the mechanism by which E7 induces re-replication, we investigated the expression and function of cell division cycle 6 (Cdc6) in E7-expressing cells. Cdc6 is a DNA replication initiation factor and exhibits oncogenic activities when overexpressed. We found that in E7-expressing cells, the steady-state level of Cdc6 protein was upregulated and its half-life was increased. Cdc6 was localized to the nucleus and associated with chromatin, especially upon DNA damage. Importantly, downregulation of Cdc6 reduced E7-induced re-replication. Interestingly, the level of Cdc6 phosphorylation at serine 54 (S54P) was increased in E7-expressing cells. S54P was associated with an increase in the total amount of Cdc6 and chromatin-bound Cdc6. DNA damage-enhanced upregulation and chromatin binding of Cdc6 appeared to be due to downregulation of cyclin-dependent kinase 1 (Cdk1) as Cdk1 knockdown increased Cdc6 levels. Furthermore, Cdk1 knockdown or inhibition led to re-replication. These findings shed light on the mechanism by which HPV induces genomic instability and may help identify potential targets for drug development. PMID:27207654

  15. Posttranscriptional regulation of cellular gene expression by the c-myc oncogene

    SciTech Connect

    Prendergast, G.C.; Cole, M.D. . Dept. of Biology)

    1989-01-01

    The c-myc oncogene has been implicated in the development of many different cancers, yet the mechanism by which the c-myc protein alters cellular growth control has proven elusive. The authors used a cDNA hybridization difference assay to isolate two genes, mr1 and mr2, that were constitutively expressed (i.e., deregulated) in rodent fibroblast cell lines immortalized by transfection of a viral promoter-linked c-myc gene. Both cDNAs were serum inducible in quiescent G/sub o/ fibroblasts, suggesting that they are functionally related to cellular proliferative processes. Although there were significant differences in cytoplasmic mRNA levels between myc-immortalized and control cells, the rates of transcription and mRNA turnover of both genes were similar, suggesting that c-myc regulates mr1 and mr2 expression by some nuclear posttranscriptional mechanism. Their results provide evidence that c-myc can rapidly modulate cellular gene expression and suggest that c-myc may function in gene regulation at the level of RNA export, splicing, or nuclear RNA turnover.

  16. Activation and repression by oncogenic MYC shape tumour-specific gene expression profiles.

    PubMed

    Walz, Susanne; Lorenzin, Francesca; Morton, Jennifer; Wiese, Katrin E; von Eyss, Björn; Herold, Steffi; Rycak, Lukas; Dumay-Odelot, Hélène; Karim, Saadia; Bartkuhn, Marek; Roels, Frederik; Wüstefeld, Torsten; Fischer, Matthias; Teichmann, Martin; Zender, Lars; Wei, Chia-Lin; Sansom, Owen; Wolf, Elmar; Eilers, Martin

    2014-07-24

    In mammalian cells, the MYC oncoprotein binds to thousands of promoters. During mitogenic stimulation of primary lymphocytes, MYC promotes an increase in the expression of virtually all genes. In contrast, MYC-driven tumour cells differ from normal cells in the expression of specific sets of up- and downregulated genes that have considerable prognostic value. To understand this discrepancy, we studied the consequences of inducible expression and depletion of MYC in human cells and murine tumour models. Changes in MYC levels activate and repress specific sets of direct target genes that are characteristic of MYC-transformed tumour cells. Three factors account for this specificity. First, the magnitude of response parallels the change in occupancy by MYC at each promoter. Functionally distinct classes of target genes differ in the E-box sequence bound by MYC, suggesting that different cellular responses to physiological and oncogenic MYC levels are controlled by promoter affinity. Second, MYC both positively and negatively affects transcription initiation independent of its effect on transcriptional elongation. Third, complex formation with MIZ1 (also known as ZBTB17) mediates repression of multiple target genes by MYC and the ratio of MYC and MIZ1 bound to each promoter correlates with the direction of response. PMID:25043018

  17. Tissue-specific expression and developmental regulation of the human fgr proto-oncogene

    SciTech Connect

    Levy, T.J. . Dept. of Medicine); Connolly, N.L.; Senior, R.M. ); Katamine, S.; Cheah, M.S.C.; Robbins

    1989-01-01

    In this study, the authors show that c-fgr proto-oncogene expression is limited to normal peripheral blood granulocytes, monocytes, and alveolar macrophages, all of which contain 50 to 100 copies of c-fgr mRNA per cell. The c-fgr RNA molecules in these cells consisted of partially spliced transcripts containing intron 7 and completely spliced molecules capable of encoding the predicted p55 c-fgr protein. The splicing of intron 7 appeared to occur after the splicing of most of the other introns; partially spliced molecules containing intron 7 did not appear to be transported into the cytoplasm. Very low levels of fgr transcripts were also present in U937 promonocytic cells and increased in abundance with 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiation. The level of fgr transcripts began to increase 2 to 4 after TPA addition peaked at 8 h, and subsequently declined. Since the authors found that the half-life of fgr mRNA was longer than 8 h, these changes are best explained by transient transcriptional activation of fgr during TPA-induced differentiation, although nuclear runoff experiments were not sensitive enough to detect this event. Their results demonstrate that the c-fgr gene is expressed in a tissue- and development-specific fashion and suggest that constitutive expression of c-fgr in U937 cells is regulated by a labile transcriptional repressor.

  18. Effects of telomerase and viral oncogene expression on the in vitro growth of human chondrocytes.

    PubMed

    Martin, James A; Mitchell, Calista J; Klingelhutz, Aloysius J; Buckwalter, Joseph A

    2002-02-01

    Senescent chondrocytes accumulate with aging in articular cartilage, a process that interferes with cartilage homeostasis and increases the risk of cartilage degeneration. We showed previously that chondrocyte telomere length declines with donor age, which suggests that the aging process is telomere dependent. From these results we hypothesized that telomerase should delay the onset of senescence in cultured chondrocytes. Population doubling limits (PDL) were determined for chondrocytes expressing telomerase. We found that telomerase alone did not extend PDL beyond controls that senesced after 25 population doublings. The human papillomavirus 16 oncogenes E6 and E7 were transduced into the same cell population to investigate this telomere-independent form of senescence further. Chondrocytes expressing E6 and E7 grew longer than the telomerase cDNA (hTERT) cells but still senesced at 55 population doublings. In contrast, chondrocytes expressing telomerase with E6 and E7 grew vigorously past 100 population doublings. We conclude that although telomerase is necessary for the indefinite extension of chondrocyte life span, telomere-independent senescence limits PDL in vitro and may play a role in the age-related accumulation of senescent chondrocytes in vivo. PMID:11818423

  19. Tissue-Specific Regulation of Oncogene Expression Using Cre-Inducible ROSA26 Knock-In Transgenic Mice.

    PubMed

    Carofino, Brandi L; Justice, Monica J

    2015-01-01

    Cre-inducible mouse models are often utilized for the spatial and temporal expression of oncogenes. With the wide number of Cre recombinase lines available, inducible transgenesis represents a tractable approach to achieve discrete oncogene expression. Here, we describe a protocol for targeting Cre-inducible genes to the ubiquitously expressed ROSA26 locus. Gene targeting provides several advantages over standard transgenic techniques, including a known site of integration and previously characterized pattern of expression. Historically, an inherent instability of ROSA26 targeting vectors has hampered the efficiency of developing ROSA26 knock-in lines. In this protocol, we provide individual steps for utilizing Gateway recombination for cloning as well as detailed instructions for screening targeted ES cell clones. By following this protocol, one can achieve germline transmission of a ROSA26 knock-in line within several months. PMID:26069083

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

    PubMed Central

    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

  1. ZYG11A serves as an oncogene in non-small cell lung cancer and influences CCNE1 expression

    PubMed Central

    Wang, Xin; Sun, Qi; Chen, Chen; Yin, Rong; Huang, Xing; Wang, Xuan; Shi, Run; Xu, Lin; Ren, Binhui

    2016-01-01

    By analyzing The Cancer Genome Atlas (TCGA) database, we identified ZYG11A as a potential oncogene. We determined the expression of ZYG11A in NSCLC tissues and explored its clinical significance. And also evaluated the effects of ZYG11A on NSCLC cell proliferation, migration, and invasion both in vitro and in vivo. Our results show that ZYG11A is hyper-expressed in NSCLC tissues compared to adjacent normal tissues, and increased expression of ZYG11A is associated with a poor prognosis (HR: 2.489, 95%CI: 1.248-4.963, p = 0.010). ZYG11A knockdown induces cell cycle arrest and inhibits proliferation, migration, and invasion of NSCLC cells. ZYG11A knockdown also results in decreased expression of CCNE1. Over-expression of CCNE1 in cells with ZYG11A knockdown restores their oncogenic activities. Our data suggest that ZYG11A may serve as a novel oncogene promoting tumorigenicity of NSCLC cells by inducing cell cycle alterations and increasing CCNE1 expression. PMID:26771237

  2. Tissue-specific expression and developmental regulation of the human fgr proto-oncogene.

    PubMed Central

    Ley, T J; Connolly, N L; Katamine, S; Cheah, M S; Senior, R M; Robbins, K C

    1989-01-01

    In this study, we show that c-fgr proto-oncogene expression is limited to normal peripheral blood granulocytes, monocytes, and alveolar macrophages, all of which contain 50 to 100 copies of c-fgr mRNA per cell. The c-fgr RNA molecules in these cells consisted of partially spliced transcripts containing intron 7 and completely spliced molecules capable of encoding the predicted p55 c-fgr protein. The splicing of intron 7 appeared to occur after the splicing of most of the other introns; partially spliced molecules containing intron 7 did not appear to be transported into the cytoplasm. Very low levels of fgr transcripts were also present in U937 promonocytic cells and increased in abundance with 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiation. The level of fgr transcripts began to increase 2 to 4 h after TPA addition, peaked at 8 h, and subsequently declined. Since we found that the half-life of fgr mRNA was longer than 8 h, these changes are best explained by transient transcriptional activation of fgr during TPA-induced differentiation, although nuclear runoff experiments were not sensitive enough to detect this event. Cycloheximide also caused accumulation of c-fgr transcripts in U937 cells; no superinduction was observed when TPA and cycloheximide were added at the same time. Induction by either agent was blocked with actinomycin D. These results demonstrate that the c-fgr gene is expressed in a tissue- and development-specific fashion and suggest that constitutive expression of c-fgr in U937 cells is regulated by a labile transcriptional repressor. Images PMID:2538725

  3. Merkel cell carcinoma subgroups by Merkel cell polyomavirus DNA relative abundance and oncogene expression

    PubMed Central

    Bhatia, Kishor; Goedert, James J.; Modali, Rama; Preiss, Liliana; Ayers, Leona W.

    2010-01-01

    Merkel cell polyomavirus (MCPyV) was recently discovered in Merkel cell carcinoma (MCC), a clinically and pathologically heterogeneous malignancy of dermal neuroendocrine cells. To investigate this heterogeneity, we developed a tissue microarray (TMA) to characterize immunohistochemical staining of candidate tumor cell proteins and a quantitative PCR assay to detect MCPyV and measure viral loads. MCPyV was detected in 19 of 23 (74%) primary MCC tumors, but 8 of these had less than 1 viral copy per 300 cells. Viral abundance of 0.06–1.2viral copies/cell was directly related to presence of retinoblastoma gene product (pRb) and terminal deoxyribonucleotidyl transferase (TdT) by immunohistochemical staining (P≤0.003). Higher viral abundance tumors tended to be associated with less p53 expression, younger age at diagnosis, and longer survival (P≤0.08). These data suggest that MCC may arise through different oncogenic pathways, including ones independent of pRb and MCPyV. PMID:19551862

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

    PubMed Central

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

    2014-01-01

    Tumourigenic transformation of normal cells into cancer typically involves several steps resulting in acquisition of unlimited growth potential, evasion of apoptosis and non-responsiveness to growth inhibitory signals. Both genetic and epigenetic changes can contribute to cancer development and progression. Given the vast genetic heterogeneity of human cancers and difficulty to monitor cancer-initiating events in vivo, the precise relationship between acquisition of genetic mutations and the temporal progression of epigenetic alterations in transformed cells is largely unclear. Here, we use an in vitro model system to investigate the contribution of cellular immortality and oncogenic transformation of primary human cells to epigenetic reprogramming of DNA methylation and gene expression. Our data demonstrate that extension of replicative life span of the cells is sufficient to induce accumulation of DNA methylation at gene promoters and large-scale changes in gene expression in a time-dependent manner. In contrast, continuous expression of cooperating oncogenes in immortalized cells, although essential for anchorage-independent growth and evasion of apoptosis, does not affect de novo DNA methylation at promoters and induces subtle expression changes. Taken together, these observations imply that cellular immortality promotes epigenetic adaptation to highly proliferative state, whereas transforming oncogenes confer additional properties to transformed human cells. PMID:24371281

  5. Expression of EBV-encoded oncogenes and EBV-like virions in multiple canine tumors.

    PubMed

    Chiu, Hung-Chuan; Chow, Kuan-Chih; Fan, Yi-Hsin; Chang, Shih-Chieh; Chiou, Shiow-Her; Chiang, Shu-Fen; Chiou, Che-Hao; Wu, Guo-Hua; Yang, Hsiu-Ching; Ho, Shu-Peng; Chen, Yuh-Kun; Lee, Wei-Cheng; Sun, H Sunny

    2013-04-12

    Epstein-Barr virus (EBV) is a ubiquitous human oncovirus. Previous studies by us and others have indicated that pet dogs frequently encounter EBV or EBV-related viral infection. In this study, we explored whether EBV is involved in canine malignancies in dogs. EBV-specific BamHI W sequence was detected by polymerase chain reaction (PCR) in 10 of 12 canine tumor specimens, including 8 of 10 oral tumors. Using reverse transcription-PCR, gene expressions of latent membrane protein 1 (LMP 1) and BamHI H rightward reading frame 1 (BHRF1) were identified in 8 and 7 of 12 specimens, respectively. A novel LMP1 variant, T0905, was predominant in 5 canine tumor specimens and found to exist in EBV positive human BC-2 cells. Another LMP1 variant, T0902, was similar to human tumor variant JB7. The BHRF1 sequence identified from these canine tumors was identical to that of the B95-8 viral strain. LMP1 protein and EBV-encoded RNA (EBER) were detected by immunohistochemistry and fluorescent in situ hybridization, respectively, in several tumors, particularly in tumor nests of oral amelanotic melanomas. Furthermore, EBV-like virions adopting a herpesvirus egress pathway were detected in a canthal fibroblastic osteosarcoma and an oral amelanotic melanoma. In conclusion, we report the expressions of BHRF1 transcript (a viral anti-apoptotic protein), LMP1 (a viral oncoprotein) transcript and protein, EBER (a viral oncogenic RNA), and EBV-like virions in multiple canine tumors. The identity of BHRF1 and the resemblance of LMP1 variants between canine and human tumors indicate either a close evolutionary relationship between canine and human EBV, or the possibility of zoonotic transmission. PMID:23380461

  6. 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

  7. Preventive efficacy of receptor class selective retinoids on HER-2/neu oncogene expressing preneoplastic human mammary epithelial cells.

    PubMed

    Jinno, Hiromitsu; Steiner, Melissa G; Nason-Burchenal, Kathryn; Osborne, Michael P; Telang, Nitin T

    2002-07-01

    Aberrant proliferation is an early-occurring event in vitro prior to tumorigenesis in vivo in the multistep process of carcinogenesis. Inhibition of aberrant proliferation therefore may represent a useful biomarker to evaluate the efficacy of chemopreventive agents. Retinoids have exhibited preventive efficacy in vitro and in vivo predominantly through the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). Clinically relevant biochemical and cellular mechanistic endpoints for chemopreventive effects of retinoids should provide novel biomarkers. The present study was designed to examine the preventive efficacy of natural retinoids, all-trans-retinoic acid (ATRA) and 9-cis-retinoic acid (9cisRA), and to identify the possible mechanisms for their effects using the HER-2/neu oncogene expressing preneoplastic human mammary epithelial 184-B5/HER cells. Seven-day treatment with ATRA and 9cisRA exhibited a dose-dependent growth inhibition. Long-term (21 days) treatment with IC20 doses of 50 nM ATRA and 100 nM 9cisRA inhibited anchorage-dependent colony forming efficiency by about 75.4% (p<0.01) and 84.9% (p<0.01), respectively. Cell cycle analysis revealed that a 24-h treatment with IC90 doses of 2 microM ATRA and 3 microM 9cisRA accumulates cells in the G0/G1 phase and inhibit S and/or G2/M phase of the cell cycle. ATRA and 9cisRA induced an 11-fold (p=0.03) and a 9-fold (p=0.04) increase in subG0/G1 (apoptotic) population relative to the solvent control, respectively. ATRA and 9cisRA induced 77% (p=0.01) and 51% (p=0.02) decrease in tyrosine kinase immunoreactivity, respectively. Similarly, the two retinoids caused almost a 50% (p=0.01) down-regulation of Bcl-2 immunoreactivity. Western blot analysis revealed that ATRA induced an increase in RARbeta expression and a decrease in RARgamma expression, while 9cisRA down-regulated RXRalpha expression. These data demonstrate that ATRA and 9cisRA may inhibit HER-2/neu induced aberrant proliferation in part by

  8. Expression of the c-myb proto-oncogene in bovine vascular smooth muscle cells.

    PubMed

    Brown, K E; Kindy, M S; Sonenshein, G E

    1992-03-01

    Previously we have shown that bovine vascular smooth muscle cells (SMCs) express c-myb mRNA (Reilly, C. F., Kindy, M. S., Brown, K. E., Rosenberg, R. D., and Sonenshein, G. E. (1989) J. Biol. Chem. 264, 6990-6995). Here we have characterized changes in the low level of c-myb mRNA expressed in quiescent serum-deprived subconfluent SMCs upon entry into the cell cycle. After serum stimulation, levels of c-myb mRNA increased 3-4-fold during late G1 and remained at this level during S phase. A 1.5-kilobase partial c-myb cDNA clone, isolated from a bovine SMC library, was partially sequenced and found to be 89 and 85% homologous to the human and murine c-myb genes, respectively. Using bovine and murine c-myb clones, no change in the rate of c-myb gene transcription or mRNA stability was detected during the cell cycle. Thus, the regulation of changes in c-myb mRNA levels in SMCs appears distinct from mechanisms seen in hematopoietic or fibroblastic cells. Vectors containing myb binding sites linked to the thymidine kinase promoter and the chloramphenicol acetyltransferase reporter gene were transiently transfected into SMC cultures. KHK-CAT-dAX, which contains nine concatenated myb binding sites, exhibited 7-fold more activity than the parental dAX-TK-CAT vector in exponentially growing SMCs. The levels of chloramphenicol acetyltransferase activity in exponentially growing cells were approximately 2-fold higher than in cells that had been serum deprived for 24 h and were entering quiescence. Thus SMCs produce a functional c-myb protein that can activate transcription from a heterologous promoter. Furthermore, introduction of antisense c-myb oligonucleotides to quiescent serum-deprived SMC cultures severely inhibited entry of cells into S phase upon serum addition. Thus, expression of the c-myb oncogene plays an important role in cell cycle progression of SMCs. PMID:1537845

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

    PubMed

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

    2015-06-11

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

  10. Potential microRNA-mediated oncogenic intercellular communication revealed by pan-cancer analysis

    NASA Astrophysics Data System (ADS)

    Li, Yue; Zhang, Zhaolei

    2014-11-01

    Carcinogenesis consists of oncogenesis and metastasis, and intriguingly microRNAs (miRNAs) are involved in both processes. Although aberrant miRNA activities are prevalent in diverse tumor types, the exact mechanisms for how they regulate cancerous processes are not always clear. To this end, we performed a large-scale pan-cancer analysis via a novel probabilistic approach to infer recurrent miRNA-target interactions implicated in 12 cancer types using data from The Cancer Genome Atlas. We discovered ~20,000 recurrent miRNA regulations, which are enriched for cancer-related miRNAs/genes. Notably, miRNA 200 family (miR-200/141/429) is among the most prominent miRNA regulators, which is known to be involved in metastasis. Importantly, the recurrent miRNA regulatory network is not only enriched for cancer pathways but also for extracellular matrix (ECM) organization and ECM-receptor interactions. The results suggest an intriguing cancer mechanism involving miRNA-mediated cell-to-cell communication, which possibly involves delivery of tumorigenic miRNA messengers to adjacent cells via exosomes. Finally, survival analysis revealed 414 recurrent-prognostic associations, where both gene and miRNA involved in each interaction conferred significant prognostic power in one or more cancer types. Together, our comprehensive pan-cancer analysis provided not only biological insights into metastasis but also brought to bear the clinical relevance of the proposed recurrent miRNA-gene associations.

  11. Neu proto-oncogene amplification and expression in ovarian adenocarcinoma cell lines.

    PubMed Central

    King, B. L.; Carter, D.; Foellmer, H. G.; Kacinski, B. M.

    1992-01-01

    In this communication, the authors summarize their characterization of eight ovarian adenocarcinoma-derived cell lines for level of neu gene amplification, expression of neu transcripts and protein, and intraperitoneal tumorigenicity in nude mice. Two of the eight cell lines in our study (SKOV3 and YAOVBIX1) exhibited five- to ninefold neu DNA sequence amplification, accompanied by up to 200-fold overexpression of transcripts and protein (p185). Both of these cell lines expressed a major approximately 7.5 kb neu-complementary transcript not previously reported in other neu-positive tumor cell lines. One pair of cell lines (YAOVBIX1 and YAOVBIX3), isolated from a single ovarian carcinoma patient's ascites sample differed dramatically in regard to level of neu gene amplification and expression. Immunohistochemical staining of the primary ovarian tumor from which these two lines were derived demonstrated populations of both neu-positive and neu-negative malignant epithelial cells. Seven of the eight ovarian carcinoma lines produced intra-abdominal tumors after intraperitoneal injection into nude mice, irrespective of level of neu gene expression. This study demonstrates tumor cell heterogeneity with regard to neu gene amplification and expression in an ovarian adenocarcinoma, reveals the overexpression of novel neu-complementary transcripts in two independently isolated ovarian adenocarcinoma cell lines, and suggests that neu gene expression is not required for intraperitoneal tumorigenicity of ovarian carcinoma xenografts in a nude mouse model system. Images Figure 4 Figure 1 Figure 2 Figure 3 PMID:1346236

  12. Suppression of c-myc oncogene expression by a polyamine-complexed triplex forming oligonucleotide in MCF-7 breast cancer cells.

    PubMed Central

    Thomas, T J; Faaland, C A; Gallo, M A; Thomas, T

    1995-01-01

    Polyamines are excellent stabilizers of triplex DNA. Recent studies in our laboratory revealed a remarkable structural specificity of polyamines in the induction and stabilization of triplex DNA. 1,3-Diaminopropane (DAP) showed optimum efficacy amongst a series of synthetic diamines in stabilizing triplex DNA. To utilize the potential of this finding in developing an anti-gene strategy for breast cancer, we treated MCF-7 cells with a 37mer oligonucleotide to form triplex DNA in the up-stream regulatory region of the c-myc oncogene in the presence of DAP. As individual agents, the oligonucleotide and DAP did not downregulate c-myc mRNA in the presence of estradiol. Complexation of the oligonucleotide with 2 mM DAP reduced c-myc mRNA signal by 65% at 10 microM oligonucleotide concentration. In contrast, a control oligonucleotide had no significant effect on c-myc mRNA. The expression of c-fos oncogene was not significantly altered by the triplex forming oligonucleotide (TFO). DAP was internalized within 1 h of treatment; however, it had no significant effect on the level of natural polyamines. These data indicate that selective utilization of synthetic polyamines and TFOs might be an important strategy to develop anti-gene-based therapeutic modalities for breast cancer. Images PMID:7567474

  13. The TPR-MET oncogenic rearrangement is present and expressed in human gastric carcinoma and precursor lesions.

    PubMed Central

    Soman, N R; Correa, P; Ruiz, B A; Wogan, G N

    1991-01-01

    The TPR-MET oncogenic rearrangement was originally observed in an in vitro transformed human osteosarcoma cell line. Recently, we detected the expression of this rearrangement at very low levels in several cell lines derived from human tumors of nonhematopoietic origin using a highly sensitive method based on polymerase chain reaction amplification of the transcript. We report here the results of analysis of TPR-MET expression in cell lines derived from human gastric tumors and 22 biopsy samples of human gastric mucosa showing cancer or precursor lesions. The rearranged RNA was expressed in all four cell lines as well as in biopsy samples from 12 of the 22 patients. Overexpression of TPR-MET RNA in superficial gastritis lesions with hyperplasia of glandular neck cells suggests the possible involvement of this oncogene at an early stage of gastric tumorigenesis. Analysis of gastric biopsy samples for RAS gene mutations showed base substitutions occurring in the codon 12 region of Ki- and Ha-RAS genes in four cases, including two precursor lesions. Images PMID:2052572

  14. Immunohistochemichal Assessment of the CrkII Proto-oncogene Expression in Common Malignant Salivary Gland Tumors and Pleomorphic Adenoma.

    PubMed

    Askari, Mitra; Darabi, Masoud; Jahanzad, Esa; Mostakhdemian Hosseini, Zahra; Musavi Chavoshi, Marjan; Darabi, Maryam

    2015-01-01

    Background and aims. Various morphologies are seen in different salivary gland tumorsor within an individual tumor, and the lesions show divers biological behaviors. Experimental results support the hypothesis that increased CrkII proto-oncogene is associated with cytokine-induced tumor initiation and progression by altering cell motility signaling pathway. The aim of this study was to assess the CrkII expression in common malignant salivary gland tumors and pleomorphic ade-noma. Materials and methods. Immunohistochemical analysis of CrkII expression was performed on paraffin blocks of 64 car-cinomas of salivary glands, 10 pleomorphic adenomas, and 10 normal salivary glands. Biopsies were subjected to immu-nostaining with EnVision detection system using monoclonal anti-CrkII. Evaluation of immunoreactivity of CrkII was based on the immunoreaction intensity and percentage of stained tumor cells which were scored semi-quantitatively on a scale with four grades 0 to 3. Kruskal-wallis test and additional Mann-Whitney statistical test were used for analysis of CrkII expression levels. Results. Increased expression of CrkII was seen (P=0.005) in malignant tumors including: mucoepidermoid carcinoma, adenoid cystic carcinoma, and carcinoma ex pleomorphic adenoma, but CrkII expression in acinic cell carcinoma was weak. CrkII expression in pleomorphic adenoma was weak or negative. A weak staining was sparsely seen in normal acinar serous cell. Conclusion. Increased expression of CrkII and its higher intensity of staining in tumors with more aggressive biologic behavior in carcinomas of salivary gland is consistent with a role for this proto-oncogene in salivary gland tumorigenesis and cancer progression. PMID:25973151

  15. [Cell oncogene expression in normal, metaplastic, dysplastic epithelium and squamous cell carcinoma of the uterine cervix].

    PubMed

    Petrov, S V; Mazurenko, N N; Sukhova, N M; Moroz, I P; Katsenel'son, V M; Raĭkhlin, N T; Kiselev, F L

    1994-01-01

    Immunohistochemical analysis of the protein expression c-myc, ets 1, ets 2, TPR-met, c-fos, c-jun, c-ras-pan, p53, yes, src in 79 samples of normal, metaplastic squamous epithelium, intraepithelial and invasive squamous cell carcinoma of uterine cervix was performed using polyclonal rabbit antibodies to the synthetic peptides homologous active areas of corresponding oncoproteins. Higher content of myc, fos, ets2, p53, ras is noted in metaplasia, dysplasia and in tumours as compared to the normal tissues. Protein myc is revealed in the cytoplasm at a grave dysplasia and in the nucleus in the intraepithelial carcinoma: this may serve as a criterion at a differential diagnosis of these conditions. Expression of the oncoproteins fos, ets2, p53, src in the metaplastic squamous cell carcinoma was higher than in the true squamous cell (ectocervical) carcinoma. When compared to the advanced carcinomas, increase of ets2, p53, and at some degree that of myc, the increase is noted in the latter. Invasive carcinoma with a high level of oncoproteins showed a tendency to the synchronization of myc and ras expression. Poor prognosis was associated with a low level (before treatment) of the expression of the majority of the oncoproteins studied. PMID:7848100

  16. Expression of the human ETS-2 oncogene in normal fetal tissues and in the brain of a fetus with trisomy 21.

    PubMed

    Baffico, M; Perroni, L; Rasore-Quartino, A; Scartezzini, P

    1989-10-01

    The expression of the ETS-2 proto-oncogene, located on chromosome 21, in normal fetal tissues and in neural tissue of a fetus affected by Down syndrome has been investigated. The results show that the ETS-2 proto-oncogene is expressed in almost all the tissues examined and that it is transcribed at constant levels in neural tissue between the 13th and 24th weeks. ETS-2 expression appeared to be slightly increased in Down syndrome brain compared with that of normal controls of the same gestational age. PMID:2529204

  17. Initiation of transcription from the minute virus of mice P4 promoter is stimulated in rat cells expressing a c-Ha-ras oncogene.

    PubMed Central

    Spegelaere, P; van Hille, B; Spruyt, N; Faisst, S; Cornelis, J J; Rommelaere, J

    1991-01-01

    Transformation of FR3T3 rat fibroblasts by a c-Ha-ras oncogene but not by bovine papillomavirus type 1 is associated with an increase in the abundance of mRNAs from prototype strain MVMp of infecting minute virus of mice, an oncosuppressive parvovirus. This differential parvovirus gene expression correlates with the reported sensitization of ras- but not bovine papillomavirus type 1-transformed cells to the killing effect of MVMp (N. Salomé, B. van Hille, N. Duponchel, G. Meneguzzi, F. Cuzin, J. Rommelaere, and J. Cornelis, Oncogene 5:123-130, 1990). Experiments were performed to determine at which level parvovirus expression is up-regulated in ras transformants. An MVMp "attenuation" sequence responsible for the premature arrest of RNA elongation was either placed or not placed in front of the chloramphenicol acetyltransferase gene and brought under the control of MVMp early promoter P4. Although the MVMp attenuator reduced P4-driven chloramphenicol acetyltransferase expression, the extent of attenuation was similar in normal and ras-transformed cells. Moreover, the analysis of P4-directed viral RNAs in MVMp-infected cultures by RNase protection and nuclear run-on assays also revealed a transcription elongation block of a similar amplitude in both types of cells. In addition, the stabilities of the three major parvoviral mRNAs did not vary significantly between normal and ras-transformed cells. Hence, it is concluded that the ras-induced increase in the accumulation of parvoviral mRNAs is mainly controlled at the level of transcription. Consistently, the TATA motif of the P4 promoter proved to have a differential photoreactivity when tested by in vivo UV footprinting assays in ras-transformed versus normal cells. Images PMID:1651412

  18. The expression of heat shock protein hsp27 and a complexed 22-kilodalton protein is inversely correlated with oncogenicity of adenovirus-transformed cells.

    PubMed Central

    Zantema, A; de Jong, E; Lardenoije, R; van der Eb, A J

    1989-01-01

    We isolated a monoclonal antibody that immunoprecipitated two proteins of 22 and 27 kilodaltons (kDa) from nononcogenic adenovirus type 5 early region 1 (E1)-transformed rat cells but not from oncogenic adenovirus type 12 E1-transformed rat cells. In a variety of adenovirus-transformed cells including cells transformed by E1A and the c-H-ras oncogene, we found a perfect, inverse correlation between the presence of these two proteins and the oncogenicity of these cells in syngeneic immunocompetent rats. Characterization of the two proteins revealed that they occur in a large (700-kDa) complex and that the 27-kDa protein is identical to the already known 27-kDa (28-kDa) heat shock protein hsp27. The suppression of the hsp27 protein in oncogenic cells is further demonstrated by the fact that its mRNA is absent even after heat-shock induction. Images PMID:2746733

  19. Flavopiridol induces BCL-2 expression and represses oncogenic transcription factors in leukemic blasts from adults with refractory acute myeloid leukemia

    PubMed Central

    Nelson, Dwella M.; Joseph, Biju; Hillion, Joelle; Segal, Jodi; Karp, Judith E.; Resar, Linda M. S.

    2011-01-01

    Flavopiridol is a cyclin-dependent kinase inhibitor that induces cell cycle arrest, apoptosis, and clinical responses in selected patients with acute myeloid leukemia (AML). A better understanding of the molecular pathways targeted by flavopiridol is needed to design optimal combinatorial therapy. Here, we report that in vivo administration of flavopiridol induced expression of the BCL-2 anti-apoptotic gene in leukemic blasts from adult patients with refractory AML. Moreover, flavopiridol repressed the expression of genes encoding oncogenic transcription factors (HMGA1, STAT3, E2F1) and the major subunit of RNA Polymerase II. Our results provide mechanistic insight into the cellular pathways targeted by flavopiridol and suggest that blocking anti-apoptotic pathways could enhance cytotoxicity and improve outcomes in patients treated with flavopiridol. PMID:21728742

  20. Cell-cycle dependent expression of a translocation-mediated fusion oncogene mediates checkpoint adaptation in rhabdomyosarcoma.

    PubMed

    Kikuchi, Ken; Hettmer, Simone; Aslam, M Imran; Michalek, Joel E; Laub, Wolfram; Wilky, Breelyn A; Loeb, David M; Rubin, Brian P; Wagers, Amy J; Keller, Charles

    2014-01-01

    Rhabdomyosarcoma is the most commonly occurring soft-tissue sarcoma in childhood. Most rhabdomyosarcoma falls into one of two biologically distinct subgroups represented by alveolar or embryonal histology. The alveolar subtype harbors a translocation-mediated PAX3:FOXO1A fusion gene and has an extremely poor prognosis. However, tumor cells have heterogeneous expression for the fusion gene. Using a conditional genetic mouse model as well as human tumor cell lines, we show that that Pax3:Foxo1a expression is enriched in G2 and triggers a transcriptional program conducive to checkpoint adaptation under stress conditions such as irradiation in vitro and in vivo. Pax3:Foxo1a also tolerizes tumor cells to clinically-established chemotherapy agents and emerging molecularly-targeted agents. Thus, the surprisingly dynamic regulation of the Pax3:Foxo1a locus is a paradigm that has important implications for the way in which oncogenes are modeled in cancer cells. PMID:24453992

  1. The Circular RNA Cdr1as Act as an Oncogene in Hepatocellular Carcinoma through Targeting miR-7 Expression.

    PubMed

    Yu, Lei; Gong, Xuejun; Sun, Lei; Zhou, Qiying; Lu, Baoling; Zhu, Liying

    2016-01-01

    CircRNAs are a class of endogenous RNA that regulates gene expression at the post-transcriptional or transcriptionallevel through interacting with other molecules or microRNAs. Increasing studies have demonstrated that circRNAs play a crucial role in biology processes. CircRNAs are proved as potentialbiomarkers in many diseases including cancers. However, the role of Cdr1as in Hepatocellular carcinoma (HCC) remains to be elucidated. We demonstrated that Cdr1as expression was upregulated in HCC tissues compared with the adjacent non-tumor tissues. In addtion, miR-7 expression was downregulated in HCC tissues compared with the adjacent non-tumor tissues. Moreover, the expression level of miR-7 was inversely correlated with that in HCC tissues. Knockdown of Cdr1as suppressed the HCC cell proliferation and invasion. Overexpression of miR-7 inhibited the HCC cell proliferation and invasion. Overexpression of miR-7 could suppress the direct target gene CCNE1 and PIK3CD expression. Knockdown of Cdr1as suppressed the expression of miR-7 and also inhibited the CCNE1 and PIK3CD expression. Furthermore, knockdown of Cdr1as suppressed the HCC cell proliferation and invasion through targeting miR-7. These data suggested that Cdr1as acted as an oncogene partly through targeting miR-7 in HCC. PMID:27391479

  2. The Circular RNA Cdr1as Act as an Oncogene in Hepatocellular Carcinoma through Targeting miR-7 Expression

    PubMed Central

    Yu, Lei; Gong, Xuejun; Sun, Lei; Zhou, Qiying; Lu, Baoling; Zhu, Liying

    2016-01-01

    CircRNAs are a class of endogenous RNA that regulates gene expression at the post-transcriptional or transcriptionallevel through interacting with other molecules or microRNAs. Increasing studies have demonstrated that circRNAs play a crucial role in biology processes. CircRNAs are proved as potentialbiomarkers in many diseases including cancers. However, the role of Cdr1as in Hepatocellular carcinoma (HCC) remains to be elucidated. We demonstrated that Cdr1as expression was upregulated in HCC tissues compared with the adjacent non-tumor tissues. In addtion, miR-7 expression was downregulated in HCC tissues compared with the adjacent non-tumor tissues. Moreover, the expression level of miR-7 was inversely correlated with that in HCC tissues. Knockdown of Cdr1as suppressed the HCC cell proliferation and invasion. Overexpression of miR-7 inhibited the HCC cell proliferation and invasion. Overexpression of miR-7 could suppress the direct target gene CCNE1 and PIK3CD expression. Knockdown of Cdr1as suppressed the expression of miR-7 and also inhibited the CCNE1 and PIK3CD expression. Furthermore, knockdown of Cdr1as suppressed the HCC cell proliferation and invasion through targeting miR-7. These data suggested that Cdr1as acted as an oncogene partly through targeting miR-7 in HCC. PMID:27391479

  3. 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

  4. Comparative transcriptomic analysis reveals the oncogenic fusion protein PAX3-FOXO1 globally alters mRNA and miRNA to enhance myoblast invasion

    PubMed Central

    Loupe, J M; Miller, P J; Bonner, B P; Maggi, E C; Vijayaraghavan, J; Crabtree, J S; Taylor, C M; Zabaleta, J; Hollenbach, A D

    2016-01-01

    Rhabdomyosarcoma, one of the most common childhood sarcomas, is comprised of two main subtypes, embryonal and alveolar (ARMS). ARMS, the more aggressive subtype, is primarily characterized by the t(2;13)(p35;p14) chromosomal translocation, which fuses two transcription factors, PAX3 and FOXO1 to generate the oncogenic fusion protein PAX3-FOXO1. Patients with PAX3-FOXO1-postitive tumors have a poor prognosis, in part due to the enhanced local invasive capacity of these cells, which leads to the increased metastatic potential for this tumor. Despite this knowledge, little is known about the role that the oncogenic fusion protein has in this increased invasive potential. In this report we use large-scale comparative transcriptomic analyses in physiologically relevant primary myoblasts to demonstrate that the presence of PAX3-FOXO1 is sufficient to alter the expression of 70 mRNA and 27 miRNA in a manner predicted to promote cellular invasion. In contrast the expression of PAX3 alters 60 mRNA and 23 miRNA in a manner predicted to inhibit invasion. We demonstrate that these alterations in mRNA and miRNA translate into changes in the invasive potential of primary myoblasts with PAX3-FOXO1 increasing invasion nearly 2-fold while PAX3 decreases invasion nearly 4-fold. Taken together, these results allow us to build off of previous reports and develop a more expansive molecular model by which the presence of PAX3-FOXO1 alters global gene regulatory networks to enhance the local invasiveness of cells. Further, the global nature of our observed changes highlights the fact that instead of focusing on a single-gene target, we must develop multi-faceted treatment regimens targeting multiple genes of a single oncogenic phenotype or multiple genes that target different oncogenic phenotypes for tumor progression. PMID:27454080

  5. Comparative transcriptomic analysis reveals the oncogenic fusion protein PAX3-FOXO1 globally alters mRNA and miRNA to enhance myoblast invasion.

    PubMed

    Loupe, J M; Miller, P J; Bonner, B P; Maggi, E C; Vijayaraghavan, J; Crabtree, J S; Taylor, C M; Zabaleta, J; Hollenbach, A D

    2016-01-01

    Rhabdomyosarcoma, one of the most common childhood sarcomas, is comprised of two main subtypes, embryonal and alveolar (ARMS). ARMS, the more aggressive subtype, is primarily characterized by the t(2;13)(p35;p14) chromosomal translocation, which fuses two transcription factors, PAX3 and FOXO1 to generate the oncogenic fusion protein PAX3-FOXO1. Patients with PAX3-FOXO1-postitive tumors have a poor prognosis, in part due to the enhanced local invasive capacity of these cells, which leads to the increased metastatic potential for this tumor. Despite this knowledge, little is known about the role that the oncogenic fusion protein has in this increased invasive potential. In this report we use large-scale comparative transcriptomic analyses in physiologically relevant primary myoblasts to demonstrate that the presence of PAX3-FOXO1 is sufficient to alter the expression of 70 mRNA and 27 miRNA in a manner predicted to promote cellular invasion. In contrast the expression of PAX3 alters 60 mRNA and 23 miRNA in a manner predicted to inhibit invasion. We demonstrate that these alterations in mRNA and miRNA translate into changes in the invasive potential of primary myoblasts with PAX3-FOXO1 increasing invasion nearly 2-fold while PAX3 decreases invasion nearly 4-fold. Taken together, these results allow us to build off of previous reports and develop a more expansive molecular model by which the presence of PAX3-FOXO1 alters global gene regulatory networks to enhance the local invasiveness of cells. Further, the global nature of our observed changes highlights the fact that instead of focusing on a single-gene target, we must develop multi-faceted treatment regimens targeting multiple genes of a single oncogenic phenotype or multiple genes that target different oncogenic phenotypes for tumor progression. PMID:27454080

  6. Sterol Regulatory Element Binding Protein Regulates the Expression and Metabolic Functions of Wild-Type and Oncogenic IDH1.

    PubMed

    Ricoult, Stéphane J H; Dibble, Christian C; Asara, John M; Manning, Brendan D

    2016-09-15

    Sterol regulatory element binding protein (SREBP) is a major transcriptional regulator of the enzymes underlying de novo lipid synthesis. However, little is known about the SREBP-mediated control of processes that indirectly support lipogenesis, for instance, by supplying reducing power in the form of NAPDH or directing carbon flux into lipid precursors. Here, we characterize isocitrate dehydrogenase 1 (IDH1) as a transcriptional target of SREBP across a spectrum of cancer cell lines and human cancers. IDH1 promotes the synthesis of lipids specifically from glutamine-derived carbons. Neomorphic mutations in IDH1 occur frequently in certain cancers, leading to the production of the oncometabolite 2-hydroxyglutarate (2-HG). We found that SREBP induces the expression of oncogenic IDH1 and influences 2-HG production from glucose. Treatment of cells with 25-hydroxycholesterol or statins, which respectively inhibit or activate SREBP, further supports SREBP-mediated regulation of IDH1 and, in cells with oncogenic IDH1, carbon flux into 2-HG. PMID:27354064

  7. mTORC1 upregulation via ERK-dependent gene expression change confers intrinsic resistance to MEK inhibitors in oncogenic KRas-mutant cancer cells.

    PubMed

    Komatsu, N; Fujita, Y; Matsuda, M; Aoki, K

    2015-11-01

    Cancer cells harboring oncogenic BRaf mutants, but not oncogenic KRas mutants, are sensitive to MEK inhibitors (MEKi). The mechanism underlying the intrinsic resistance to MEKi in KRas-mutant cells is under intensive investigation. Here, we pursued this mechanism by live imaging of extracellular signal-regulated kinases (ERK) and mammalian target of rapamycin complex 1 (mTORC1) activities in oncogenic KRas or BRaf-mutant cancer cells. We established eight cancer cell lines expressing Förster resonance energy transfer (FRET) biosensors for ERK activity and S6K activity, which was used as a surrogate marker for mTORC1 activity. Under increasing concentrations of MEKi, ERK activity correlated linearly with the cell growth rate in BRaf-mutant cancer cells, but not KRas-mutant cancer cells. The administration of PI3K inhibitors resulted in a linear correlation between ERK activity and cell growth rate in KRas-mutant cancer cells. Intriguingly, mTORC1 activity was correlated linearly with the cell growth rate in both BRaf-mutant cancer cells and KRas-mutant cancer cells. These observations suggested that mTORC1 activity had a pivotal role in cell growth and that the mTORC1 activity was maintained primarily by the ERK pathway in BRaf-mutant cancer cells and by both the ERK and PI3K pathways in KRas-mutant cancer cells. FRET imaging revealed that MEKi inhibited mTORC1 activity with slow kinetics, implying transcriptional control of mTORC1 activity by ERK. In agreement with this observation, MEKi induced the expression of negative regulators of mTORC1, including TSC1, TSC2 and Deptor, which occurred more significantly in BRaf-mutant cells than in KRas-mutant cells. These findings suggested that the suppression of mTORC1 activity and induction of negative regulators of mTORC1 in cancer cells treated for at least 1 day could be used as surrogate markers for the MEKi sensitivity of cancer cells. PMID:25703330

  8. Crystal structure of EML1 reveals the basis for Hsp90 dependence of oncogenic EML4-ALK by disruption of an atypical β-propeller domain

    PubMed Central

    Richards, Mark W.; Law, Edward W. P.; Rennalls, La’Verne P.; Busacca, Sara; O’Regan, Laura; Fry, Andrew M.; Fennell, Dean A.; Bayliss, Richard

    2014-01-01

    Proteins of the echinoderm microtubule-associated protein (EMAP)-like (EML) family contribute to formation of the mitotic spindle and interphase microtubule network. They contain a unique hydrophobic EML protein (HELP) motif and a variable number of WD40 repeats. Recurrent gene rearrangements in nonsmall cell lung cancer fuse EML4 to anaplastic lymphoma kinase (ALK), causing expression of several fusion oncoprotein variants. We have determined a 2.6-Å crystal structure of the representative ∼70-kDa core of EML1, revealing an intimately associated pair of β-propellers, which we term a TAPE (tandem atypical propeller in EMLs) domain. One propeller is highly atypical, having a discontinuous subdomain unrelated to a WD40 motif in place of one of its blades. This unexpected feature shows how a propeller structure can be assembled from subdomains with distinct folds. The HELP motif is not an independent domain but forms part of the hydrophobic core that joins the two β-propellers. The TAPE domain binds α/β-tubulin via its conserved, concave surface, including part of the atypical blade. Mapping the characteristic breakpoints of each EML4-ALK variant onto our structure indicates that the EML4 TAPE domain is truncated in many variants in a manner likely to make the fusion protein structurally unstable. We found that the heat shock protein 90 (Hsp90) inhibitor ganetespib induced degradation of these variants whereas others lacking a partial TAPE domain were resistant in both overexpression models and patient-derived cell lines. The Hsp90-sensitive EML4-ALK variants are exceptions to the rule that oncogenic fusion proteins involve breakpoints in disordered regions of both partners. PMID:24706829

  9. Epigenome Mapping Reveals Distinct Modes of Gene Regulation and Widespread Enhancer Reprogramming by the Oncogenic Fusion Protein EWS-FLI1

    PubMed Central

    Tomazou, Eleni M.; Sheffield, Nathan C.; Schmidl, Christian; Schuster, Michael; Schönegger, Andreas; Datlinger, Paul; Kubicek, Stefan; Bock, Christoph; Kovar, Heinrich

    2015-01-01

    Summary Transcription factor fusion proteins can transform cells by inducing global changes of the transcriptome, often creating a state of oncogene addiction. Here, we investigate the role of epigenetic mechanisms in this process, focusing on Ewing sarcoma cells that are dependent on the EWS-FLI1 fusion protein. We established reference epigenome maps comprising DNA methylation, seven histone marks, open chromatin states, and RNA levels, and we analyzed the epigenome dynamics upon downregulation of the driving oncogene. Reduced EWS-FLI1 expression led to widespread epigenetic changes in promoters, enhancers, and super-enhancers, and we identified histone H3K27 acetylation as the most strongly affected mark. Clustering of epigenetic promoter signatures defined classes of EWS-FLI1-regulated genes that responded differently to low-dose treatment with histone deacetylase inhibitors. Furthermore, we observed strong and opposing enrichment patterns for E2F and AP-1 among EWS-FLI1-correlated and anticorrelated genes. Our data describe extensive genome-wide rewiring of epigenetic cell states driven by an oncogenic fusion protein. PMID:25704812

  10. Conditional overexpression of Stat3alpha in differentiating myeloid cells results in neutrophil expansion and induces a distinct, antiapoptotic and pro-oncogenic gene expression pattern.

    PubMed

    Redell, Michele S; Tsimelzon, Anna; Hilsenbeck, Susan G; Tweardy, David J

    2007-10-01

    Normal neutrophil development requires G-CSF signaling, which includes activation of Stat3. Studies of G-CSF-mediated Stat3 signaling in cell culture and transgenic mice have yielded conflicting data regarding the role of Stat3 in myelopoiesis. The specific functions of Stat3 remain unclear, in part, because two isoforms, Stat3alpha and Stat3beta, are expressed in myeloid cells. To understand the contribution of each Stat3 isoform to myelopoiesis, we conditionally overexpressed Stat3alpha or Stat3beta in the murine myeloid cell line 32Dcl3 (32D) and examined the consequences of overexpression on cell survival and differentiation. 32D cells induced to overexpress Stat3alpha, but not Stat3beta, generated a markedly higher number of neutrophils in response to G-CSF. This effect was a result of decreased apoptosis but not of increased proliferation. Comparison of gene expression profiles of G-CSF-stimulated, Stat3alpha-overexpressing 32D cells with those of cells with normal Stat3alpha expression revealed novel Stat3 gene targets, which may contribute to neutrophil expansion and improved survival, most notably Slc28a2, a purine nucleoside transporter, which is critical for maintenance of intracellular nucleotide levels and prevention of apoptosis, and Gpr65, an acid-sensing, G protein-coupled receptor with pro-oncogenic and antiapoptotic functions. PMID:17634277

  11. Oncogenic Activity of miR-650 in Prostate Cancer Is Mediated by Suppression of CSR1 Expression

    PubMed Central

    Zuo, Ze-Hua; Yu, Yan P.; Ding, Ying; Liu, Silvia; Martin, Amantha; Tseng, George; Luo, Jian-Hua

    2016-01-01

    Cellular stress response 1 (CSR1) is a tumor suppressor gene whose expression was frequently down-regulated in prostate cancer. The mechanism of its down-regulation, however, is not clear. Here, we show that the 3′ untranslated region of CSR1 contains a target site of miR-650. High level of miR-650 was found in prostate cancer samples and cell lines. Degradation of miR-650 by specific inhibitor dramatically increased the expression levels of CSR1. Interaction between miR-650 and its target site in the 3′ untranslated region was validated through luciferase reporter system. Mutation at the target site completely abrogated the activity of miR-650 on the 3′ untranslated region of CSR1. Inhibition of miR-650 reversed the expression suppression of CSR1, suppressed colony formation, and blocked cell cycle entry to the S phase of both PC3 and DU145 cells. Animal model showed significant decrease of tumor volume, rate of metastasis, and mortality of severe combined immunodeficient mice xenografted with PC3 or DU145 cells transformed with inhibitor of miR-650. Our analyses demonstrate that suppression of CSR1 expression is a novel mechanism critical for the oncogenic activity of miR-650. PMID:25956032

  12. Oncogenic Activity of miR-650 in Prostate Cancer Is Mediated by Suppression of CSR1 Expression.

    PubMed

    Zuo, Ze-Hua; Yu, Yan P; Ding, Ying; Liu, Silvia; Martin, Amantha; Tseng, George; Luo, Jian-Hua

    2015-07-01

    Cellular stress response 1 (CSR1) is a tumor suppressor gene whose expression was frequently down-regulated in prostate cancer. The mechanism of its down-regulation, however, is not clear. Here, we show that the 3' untranslated region of CSR1 contains a target site of miR-650. High level of miR-650 was found in prostate cancer samples and cell lines. Degradation of miR-650 by specific inhibitor dramatically increased the expression levels of CSR1. Interaction between miR-650 and its target site in the 3' untranslated region was validated through luciferase reporter system. Mutation at the target site completely abrogated the activity of miR-650 on the 3' untranslated region of CSR1. Inhibition of miR-650 reversed the expression suppression of CSR1, suppressed colony formation, and blocked cell cycle entry to the S phase of both PC3 and DU145 cells. Animal model showed significant decrease of tumor volume, rate of metastasis, and mortality of severe combined immunodeficient mice xenografted with PC3 or DU145 cells transformed with inhibitor of miR-650. Our analyses demonstrate that suppression of CSR1 expression is a novel mechanism critical for the oncogenic activity of miR-650. PMID:25956032

  13. Oncogenic K-ras confers SAHA resistance by up-regulating HDAC6 and c-myc expression.

    PubMed

    Wang, Qun; Tan, Rong; Zhu, Xin; Zhang, Yi; Tan, Zhiping; Su, Bing; Li, Yu

    2016-03-01

    Histone deacetylase inhibitors (HDIs) represent a new class of anticancer drugs. Suberoylanilide hydroxamic acid (SAHA), the first HDI approved for the treatment of cutaneous T cell lymphoma (CTCL), is currently being tested in clinical trials for other cancers. However, SAHA has been ineffective against solid tumors in many clinical trials. A better understanding of molecular mechanisms of SAHA resistance may provide the basis for improved patient selection and the enhancement of clinical efficacy. Here we demonstrate that oncogenic K-ras contributes to SAHA resistance by upregulating HDAC6 and c-myc expression. We find that the high levels of HDAC6 expression are associated with activated K-ras mutant in colon cancer patients. And expressions of HDAC6 and c-myc are increased in fibroblasts transformed with activated K-ras. Surprisingly, we find that activated K-ras transformed cells are more resistant to SAHA inhibition on cell growth and anchorage-independent colony formation. We show that a K-ras inhibitor sensitizes K-ras mutated lung cancer cells to SAHA induced growth inhibition. We also find that mutant K-ras induces HDAC6 expression by a MAP kinase dependent pathway. Our study suggests that combined treatment with SAHA and K-ras inhibitors may represent an effective strategy to overcome SAHA resistance. PMID:26848526

  14. Expression of the c-myc oncogene under control of an immunoglobulin enhancer in E mu-myc transgenic mice.

    PubMed

    Alexander, W S; Schrader, J W; Adams, J M

    1987-04-01

    Transgenic mice bearing a cellular myc oncogene coupled to the immunoglobulin heavy-chain enhancer (E mu) exhibit perturbed B-lymphocyte development and succumb to B lymphoid tumors. To investigate how the enhancer has affected myc expression, we analyzed the structure and abundance of myc transcripts in tissues of prelymphomatous mice and in the lymphomas. Expression of the E mu-myc transgene appeared to be confined largely to B lymphoid cells, being dominant in bone marrow, spleen, and lymph nodes, with no detectable expression in T cells or other hematopoietic lineages examined. The myc transcripts initiated very predominantly at the normal myc promoters, although use of the more upstream myc promoter was accentuated and an enhancer-associated promoter may be used infrequently. The level of E mu-myc transcripts in the preneoplastic lymphoid tissues and in the E mu-myc tumors was not markedly higher than myc RNA levels in proliferating normal lymphocytes. Thus, enforced expression of structurally normal myc transcripts at only a modestly elevated level has profound biological consequences. The absence of detectable endogenous c-myc RNA in any tumor, or in preneoplastic bone marrow, supports a negative feedback model for normal c-myc regulation. PMID:3037318

  15. Oncogenic K-ras confers SAHA resistance by up-regulating HDAC6 and c-myc expression

    PubMed Central

    Zhang, Yi; Tan, Zhiping; Su, Bing; Li, Yu

    2016-01-01

    Histone deacetylase inhibitors (HDIs) represent a new class of anticancer drugs. Suberoylanilide hydroxamic acid (SAHA), the first HDI approved for the treatment of cutaneous T cell lymphoma (CTCL), is currently being tested in clinical trials for other cancers. However, SAHA has been ineffective against solid tumors in many clinical trials. A better understanding of molecular mechanisms of SAHA resistance may provide the basis for improved patient selection and the enhancement of clinical efficacy. Here we demonstrate that oncogenic K-ras contributes to SAHA resistance by upregulating HDAC6 and c-myc expression. We find that the high levels of HDAC6 expression are associated with activated K-ras mutant in colon cancer patients. And expressions of HDAC6 and c-myc are increased in fibroblasts transformed with activated K-ras. Surprisingly, we find that activated K-ras transformed cells are more resistant to SAHA inhibition on cell growth and anchorage-independent colony formation. We show that a K-ras inhibitor sensitizes K-ras mutated lung cancer cells to SAHA induced growth inhibition. We also find that mutant K-ras induces HDAC6 expression by a MAP kinase dependent pathway. Our study suggests that combined treatment with SAHA and K-ras inhibitors may represent an effective strategy to overcome SAHA resistance. PMID:26848526

  16. A novel model of SCID-X1 reconstitution reveals predisposition to retrovirus-induced lymphoma but no evidence of gammaC gene oncogenicity.

    PubMed

    Scobie, Linda; Hector, Ralph D; Grant, Louise; Bell, Margaret; Nielsen, Anne A; Meikle, Sharon; Philbey, Adrian; Philbey, Adrain; Thrasher, Adrian J; Thrasher, Adrain J; Cameron, Ewan R; Blyth, Karen; Neil, James C

    2009-06-01

    The emergence of leukemia following gene transfer to restore common cytokine receptor gamma chain (gammaC) function in X-linked severe combined immunodeficiency (SCID-X1) has raised important questions with respect to gene therapy safety. To explore the risk factors involved, we tested the oncogenic potential of human gammaC in new strains of transgenic mice expressing the gene under the control of the CD2 promoter and locus control region (LCR). These mice demonstrated mildly perturbed T-cell development, with an increased proportion of thymic CD8 cells, but showed no predisposition to tumor development even on highly tumor prone backgrounds or after gamma-retrovirus infection. The human CD2-gammaC transgene rescued T and B-cell development in gammaC(-/-) mice but with an age-related delay, mimicking postnatal reconstitution in SCID-X1 gene therapy subjects. However, we noted that gammaC(-/-) mice are acutely susceptible to murine leukemia virus (MLV) leukemogenesis, and that this trait was not corrected by the gammaC transgene. We conclude that the SCID-X1 phenotype can be corrected safely by stable ectopic expression of gammaC and that the transgene is not significantly oncogenic when expressed in this context. However, an underlying predisposition conferred by the SCID-X1 background appears to collaborate with insertional mutagenesis to increase the risk of tumor development. PMID:19337236

  17. Transient expression of Bcl6 is sufficient for oncogenic function and induction of mature B-cell lymphoma

    PubMed Central

    Green, Michael R; Vicente-Dueñas, Carolina; Romero-Camarero, Isabel; Liu, Chih Long; Dai, Bo; González-Herrero, Inés; García-Ramírez, Idoia; Alonso-Escudero, Esther; Iqbal, Javeed; Chan, Wing C; Campos-Sanchez, Elena; Orfao, Alberto; Pintado, Belén; Flores, Teresa; Blanco, Oscar; Jiménez, Rafael; Martínez-Climent, Jose Angel; Criado, Francisco Javier García; Cenador, María Begoña García; Zhao, Shuchun; Natkunam, Yasodha; Lossos, Izidore S; Majeti, Ravindra; Melnick, Ari; Cobaleda, César; Alizadeh, Ash A.; Sánchez-García, Isidro

    2015-01-01

    Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma and can be separated into two subtypes based upon molecular features with similarities to germinal center B-cells (GCB-like) or activated B-cells (ABC-like). Here we identify gain of 3q27.2 as being significantly associated with adverse outcome in DLBCL and linked with the ABC-like subtype. This lesion includes the BCL6 oncogene, but does not alter BCL6 transcript levels or target-gene repression. Separately, we identify expression of BCL6 in a subset of human hematopoietic stem/progenitor cells (HSPCs). We therefore hypothesize that BCL6 may act by hit-and-run oncogenesis. We model this by transiently expressing Bcl6 within murine HSPCs, and find it causes mature B-cell lymphomas that lack Bcl6 expression and target-gene repression, are transcriptionally similar to post-GCB cells, and show epigenetic changes that are conserved from HSPCs to mature B-cells. Together these results suggest that Bcl6 may function in a hit-and-run role in lymphomagenesis. PMID:24887457

  18. LncRNA Khps1 Regulates Expression of the Proto-oncogene SPHK1 via Triplex-Mediated Changes in Chromatin Structure.

    PubMed

    Postepska-Igielska, Anna; Giwojna, Alena; Gasri-Plotnitsky, Lital; Schmitt, Nina; Dold, Annabelle; Ginsberg, Doron; Grummt, Ingrid

    2015-11-19

    Although thousands of long noncoding RNAs (lncRNAs) have been discovered, very little is known about their mode of action. Here we functionally characterize an E2F1-regulated lncRNA named Khps1, which is transcribed in antisense orientation to the proto-oncogene SPHK1. Khps1 activates SPHK1 expression by recruiting the histone acetyltransferase p300/CBP to the SPHK1 promoter, which leads to local changes of the chromatin structure that ensures E2F1 binding and enhances transcription. Mechanistically, this is achieved by direct association of Khps1 with a homopurine stretch upstream of the transcription start site of SPHK1, which forms a DNA-RNA triplex that anchors the lncRNA and associated effector proteins to the gene promoter. The results reveal an lncRNA- and E2F1-driven regulatory loop in which E2F1-dependent induction of antisense RNA leads to changes in chromatin structure, facilitating E2F1-dependent expression of SPHK1 and restriction of E2F1-induced apoptosis. PMID:26590717

  19. Current Protocols in Mouse Biology Tissue-specific regulation of oncogene expression using Cre-inducible ROSA26 knock-in transgenic mice

    PubMed Central

    Carofino, Brandi L.; Justice, Monica J.

    2015-01-01

    Cre-inducible mouse models are often utilized for the spatial and temporal expression of oncogenes. With the wide number of Cre recombinase lines available, inducible transgenesis represents a tractable approach to achieve discrete oncogene expression. Here, we describe a protocol for targeting Cre-inducible genes using a loxP-STOP-loxP approach to the ubiquitously expressed ROSA26 locus. Gene targeting provides several advantages over standard transgenic techniques, including a known site of integration and previously characterized pattern of expression. Historically, an inherent instability of ROSA26 targeting vectors has hampered the efficiency of developing ROSA26 knock-in lines. In this protocol, we provide individual steps for utilizing Gateway recombination for cloning, and detailed instructions for screening targeted ES cell clones. By following this protocol, one can achieve germline transmission of a ROSA26 knock-in line within several months. PMID:26069083

  20. Regulation of proto-oncogene expression in adult and developing lungs.

    PubMed Central

    Molinar-Rode, R; Smeyne, R J; Curran, T; Morgan, J I

    1993-01-01

    Activation of immediate-early gene expression has been associated with mitogenesis, differentiation, nerve cell depolarization, and recently, terminal differentiation processes and programmed cell death. Previous evidence also suggested that immediate-early genes play a role in the physiology of the lungs (J. I. Morgan, D. R. Cohen, J. L. Hempstead, and T. Curran, Science 237:192-197, 1987). Therefore, we analyzed c-fos expression in adult and developing lung tissues. Seizures elicited by chemoconvulsants induced expression of mRNA for c-fos, c-jun, and junB and Fos-like immunoreactivity in lung tissue. The use of pharmacological antagonists and adrenalectomy indicated that this increased expression was neurogenic. Interestingly, by using a fos-lacZ transgenic mouse, it was shown that Fos-LacZ expression in response to seizure occurred preferentially in clusters of epithelial cells at the poles of the bronchioles. This was the same location of Fos-LacZ expression detected during early lung development. These data imply that pharmacological induction of immediate-early gene expression in adult mice recapitulates an embryological program of gene expression. Images PMID:8497249

  1. Expression of galaxin and oncogene homologs in growth anomaly in the coral Montipora capitata.

    PubMed

    Spies, Narrissa P; Takabayashi, Misaki

    2013-06-13

    Growth anomaly (GA) is a coral disease characterized by enlarged skeletal lesions. Although negative effects of GA on several of coral's biological functions have been determined, the etiology and molecular pathology of this disease is very poorly understood. We studied the expression of 5 genes suspected to play a role in pathological development of GA in the endemic Hawaiian coral Montipora capitata, which is particularly susceptible to this disease. Transcript abundances of the 5 target genes in healthy tissue, GA-affected tissue, and unaffected tissue (apparently healthy tissue adjacent to GA) relative to 3 internal control genes (actin, NADH, and rpS3) were compared using quantitative reverse transcriptase PCR. Galaxin, which codes for a protein suspected to be involved in calcification and thus hypothesized to be differentially expressed in GA, was up-regulated in unaffected tissue but remained at baseline levels in GA tissue. The gene expressions of murine double minute 2 (MDM2) and tumor necrosis factor (TNF) remained unchanged in GA tissue. The expression of tyrosine protein kinase (TPK) and βγ-crystallin (BGC) were both down-regulated. These expression patterns were all inconsistent with the expression patterns of homologous genes in neoplastic diseases featuring similar morphological symptoms in humans. These expression data therefore suggest that the calcification mechanism is likely not enhanced in coral GA and that coral GA is not a malignant neoplasia. PMID:23759562

  2. 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

  3. 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.

  4. Stat3 induces oncogenic Skp2 expression in human cervical carcinoma cells

    SciTech Connect

    Huang, Hanhui; Zhao, Wenrong; Yang, Dan

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Upregulation of Skp2 by IL-6 or Stat3 activation. Black-Right-Pointing-Pointer Stat3 activates Skp2 expression through bound to its promoter region. Black-Right-Pointing-Pointer Stat3 activates Skp2 expression through recruitment of P300. Black-Right-Pointing-Pointer Stat3 activation decreases the P27 stability. -- Abstract: Dysregulated Skp2 function promotes cell proliferation, which is consistent with observations of Skp2 over-expression in many types of human cancers, including cervical carcinoma (CC). However, the molecular mechanisms underlying elevated Skp2 expression have not been fully explored. Interleukin-6 (IL-6) induced Stat3 activation is viewed as crucial for multiple tumor growth and metastasis. Here, we demonstrate that Skp2 is a direct transcriptional target of Stat3 in the human cervical carcinoma cells. Our data show that IL-6 administration or transfection of a constitutively activated Stat3 in HeLa cells activates Skp2 mRNA transcription. Using luciferase reporter and ChIP assays, we show that Stat3 binds to the promoter region of Skp2 and promotes its activity through recruiting P300. As a result of the increase of Skp2 expression, endogenous p27 protein levels are markedly decreased. Thus, our results suggest a previously unknown Stat3-Skp2 molecular network controlling cervical carcinoma development.

  5. Changes in cortical cytoskeletal and extracellular matrix gene expression in prostate cancer are related to oncogenic ERG deregulation

    PubMed Central

    2010-01-01

    Background The cortical cytoskeleton network connects the actin cytoskeleton to various membrane proteins, influencing cell adhesion, polarity, migration and response to extracellular signals. Previous studies have suggested changes in the expression of specific components in prostate cancer, especially of 4.1 proteins (encoded by EPB41 genes) which form nodes in this network. Methods Expression of EPB41L1, EPB41L2, EPB41L3 (protein: 4.1B), EPB41L4B (EHM2), EPB41L5, EPB49 (dematin), VIL2 (ezrin), and DLG1 (summarized as „cortical cytoskeleton" genes) as well as ERG was measured by quantitative RT-PCR in a well-characterized set of 45 M0 prostate adenocarcinoma and 13 benign tissues. Hypermethylation of EPB41L3 and GSTP1 was compared in 93 cancer tissues by methylation-specific PCR. Expression of 4.1B was further studied by immunohistochemistry. Results EPB41L1 and EPB41L3 were significantly downregulated and EPB41L4B was upregulated in cancer tissues. Low EPB41L1 or high EPB41L4B expression were associated with earlier biochemical recurrence. None of the other cortical cytoskeleton genes displayed expression changes, in particular EPB49 and VIL2, despite hints from previous studies. EPB41L3 downregulation was significantly associated with hypermethylation of its promoter and strongly correlated with GSTP1 hypermethylation. Protein 4.1B was detected most strongly in the basal cells of normal prostate epithelia. Its expression in carcinoma cells was similar to the weaker one in normal luminal cells. EPB41L3 downregulation and EPB41L4B upregulation were essentially restricted to the 22 cases with ERG overexpression. Expression changes in EPB41L3 and EPB41L4B closely paralleled those previously observed for the extracellular matrix genes FBLN1 and SPOCK1, respectively. Conclusions Specific changes in the cortical cytoskeleton were observed during prostate cancer progression. They parallel changes in the expression of extracellular matrix components and all together

  6. Regulation of human RNase-L by the miR-29 family reveals a novel oncogenic role in chronic myelogenous leukemia.

    PubMed

    Lee, Teresa Y; Ezelle, Heather J; Venkataraman, Thiagarajan; Lapidus, Rena G; Scheibner, Kara A; Hassel, Bret A

    2013-01-01

    The endoribonuclease RNase-L is the terminal component of an interferon-regulated RNA decay pathway known as the 2'-5'-oligoadenylate (2-5A) system, whose established functions include antimicrobial and tumor suppressive activities. RNase-L activity requires binding of the small molecule 2-5A, leading to RNase-L dimerization and cleavage of single-stranded RNA. RNase-L expression is controlled post-transcriptionally by its 3'-untranslated region (3' UTR), which exerts a strong negative effect on RNase-L levels. MicroRNAs (miRNAs) are a class of small noncoding RNAs that repress expression of target genes by binding to regions of complementarity often in the 3' UTR. The miR-29 family acts as a tumor suppressor in several cancers, including acute and chronic myelogenous leukemia (CML), and has many oncogenic targets. We report that the miR-29 family represses RNase-L protein expression across several cell types. Using a luciferase reporter, we showed that miR-29 acts via 4 target sites within the RNASEL 3' UTR. Mutation of all sites is required for abrogation of miR-29 repression. In light of the reported tumor suppressive role of miR-29 in K562 CML cells and miR-29 repression of RNase-L in these cells, we generated K562 cells with stable RNase-L knockdown and demonstrated that loss of RNase-L inhibits proliferation in vitro as well as tumor growth in a xenograft model. Our findings identify a previously unknown miRNA regulator of RNase-L expression and support a novel oncogenic role for RNase-L in CML and potentially other hematopoietic malignancies. PMID:23113544

  7. Intragenic integration in DLC1 sustains factor VIII expression in primary human cells without insertional oncogenicity

    PubMed Central

    Sivalingam, J; Phan, T T; Kon, O L

    2014-01-01

    Techniques enabling precise genome modifications enhance the safety of gene-based therapy. DLC1 is a hot spot for phiC31 integrase-mediated transgene integration in vitro and in vivo. Here we show that integration of a coagulation factor VIII transgene into intron 7 of DLC1 supports durable expression of factor VIII in primary human umbilical cord-lining epithelial cells. Oligoclonal cells with factor VIII transgene integrated in DLC1 did not have altered expression of DLC1 or neighbouring genes within a 1-Mb interval. Only 1.9% of all expressed genes were transcriptionally altered; most were downregulated and mapped to cell cycle and DNA repair pathways. DLC1-integrated cells were not tumourigenic in vivo and were normal by high-resolution genomic DNA copy number analysis. Our data identify DLC1 as a locus for durable transgene expression that does not incur features of insertional oncogenesis, thus expanding options for developing ex vivo cell therapy mediated by site-specific integration methods. PMID:24553346

  8. Loss of Dependence on Continued Expression of the Human Papillomavirus 16 E7 Oncogene in Cervical Cancers and Precancerous Lesions Arising in Fanconi Anemia Pathway-Deficient Mice

    PubMed Central

    Park, Soyeong; Park, Jung Wook; Pitot, Henry C.

    2016-01-01

    ABSTRACT   Fanconi anemia (FA) is a rare genetic disorder caused by defects in DNA damage repair. FA patients often develop squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) are known to cause cancer, including the cervix. However, SCCs found in human FA patients are often HPV negative, even though the majority of female FA patients with anogenital cancers had preexisting HPV-positive dysplasia. We hypothesize that HPVs contribute to the development of SCCs in FA patients but that the continued expression of HPV oncogenes is not required for the maintenance of the cancer state because FA deficiency leads to an accumulation of mutations in cellular genes that render the cancer no longer dependent upon viral oncogenes. We tested this hypothesis, making use of Bi-L E7 transgenic mice in which we temporally controlled expression of HPV16 E7, the dominant viral oncogene in HPV-associated cancers. As seen before, the persistence of cervical neoplastic disease was highly dependent upon the continued expression of HPV16 E7 in FA-sufficient mice. However, in mice with FA deficiency, cervical cancers persisted in a large fraction of the mice after HPV16 E7 expression was turned off, indicating that these cancers had escaped from their dependency on E7. Furthermore, the severity of precancerous lesions also failed to be reduced significantly in the mice with FA deficiency upon turning off expression of E7. These findings confirm our hypothesis and may explain the fact that, while FA patients have a high frequency of infections by HPVs and HPV-induced precancerous lesions, the cancers are frequently HPV negative. Importance   Fanconi anemia (FA) patients are at high risk for developing squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) frequently cause cancer. Yet these SCCs are often HPV negative. FA patients have a genetic defect in their capacity to repair damaged DNA. HPV oncogenes cause an

  9. Loss of Dependence on Continued Expression of the Human Papillomavirus 16 E7 Oncogene in Cervical Cancers and Precancerous Lesions Arising in Fanconi Anemia Pathway-Deficient Mice.

    PubMed

    Park, Soyeong; Park, Jung Wook; Pitot, Henry C; Lambert, Paul F

    2016-01-01

    Fanconi anemia (FA) is a rare genetic disorder caused by defects in DNA damage repair. FA patients often develop squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) are known to cause cancer, including the cervix. However, SCCs found in human FA patients are often HPV negative, even though the majority of female FA patients with anogenital cancers had preexisting HPV-positive dysplasia. We hypothesize that HPVs contribute to the development of SCCs in FA patients but that the continued expression of HPV oncogenes is not required for the maintenance of the cancer state because FA deficiency leads to an accumulation of mutations in cellular genes that render the cancer no longer dependent upon viral oncogenes. We tested this hypothesis, making use of Bi-L E7 transgenic mice in which we temporally controlled expression of HPV16 E7, the dominant viral oncogene in HPV-associated cancers. As seen before, the persistence of cervical neoplastic disease was highly dependent upon the continued expression of HPV16 E7 in FA-sufficient mice. However, in mice with FA deficiency, cervical cancers persisted in a large fraction of the mice after HPV16 E7 expression was turned off, indicating that these cancers had escaped from their dependency on E7. Furthermore, the severity of precancerous lesions also failed to be reduced significantly in the mice with FA deficiency upon turning off expression of E7. These findings confirm our hypothesis and may explain the fact that, while FA patients have a high frequency of infections by HPVs and HPV-induced precancerous lesions, the cancers are frequently HPV negative. IMPORTANCE  : Fanconi anemia (FA) patients are at high risk for developing squamous cell carcinoma (SCC) at sites where high-risk human papillomaviruses (HPVs) frequently cause cancer. Yet these SCCs are often HPV negative. FA patients have a genetic defect in their capacity to repair damaged DNA. HPV oncogenes cause an accumulation of DNA

  10. Tipping the balance between good and evil: aberrant 14-3-3ζ expression drives oncogenic TGF-β signaling in metastatic breast cancers.

    PubMed

    Morrison, Chevaun D; Schiemann, William P

    2015-01-01

    Transforming growth factor beta (TGF-β) readily suppresses the development of early-stage breast cancers, an activity that gives way to tumor promotion in their late-stage counterparts. The molecular mechanisms underlying this mysterious switch in TGF-β function remain murky. In addressing this conundrum, Xu et al. observed aberrant 14-3-3ζ expression to prevent the formation of tumor-suppressive Smad2/3:p53 complexes, while simultaneously driving the generation of oncogenic Smad2/3:Gli2 complexes. Once formed, Smad2/3:Gli2 complexes stimulate the expression of parathyroid hormone-related protein necessary for breast cancer metastasis to bone. This viewpoint highlights 14-3-3ζ as an essential driver of oncogenic signaling by Smad2/3 and TGF-β in metastatic breast cancers. PMID:26160166

  11. Perylene and coronene derivatives binding to G-rich promoter oncogene sequences efficiently reduce their expression in cancer cells.

    PubMed

    Micheli, Emanuela; Altieri, Alessandro; Cianni, Lorenzo; Cingolani, Chiara; Iachettini, Sara; Bianco, Armandodoriano; Leonetti, Carlo; Cacchione, Stefano; Biroccio, Annamaria; Franceschin, Marco; Rizzo, Angela

    2016-06-01

    A novel approach to cancer therapeutics is emerging in the field of G-quadruplex (G4) ligands, small molecules designed to stabilize four-stranded structures that can form at telomeres as well as in other genomic sequences, including oncogene promoter sequences, 5'-UTR regions and introns. In this study, we investigated the binding activity of perylene and coronene derivatives PPL3C, CORON and EMICORON to G4 structures formed within the promoter regions of two important cancer-related genes, c-MYC and BCL-2, and their biochemical effects on gene and protein expression. In order to fully characterize the ability of the selected ligands to bind and stabilize the G4 structures originated by the c-MYC and BCL-2 promoter sequences, we performed electrospray ionization mass spectrometry (ESI-MS), Fluorescence Resonance Energy Transfer (FRET) measurements, Circular Dichroism (CD) spectra and polymerase stop assay. Altogether our results showed that the ligands had a high capacity in binding and stabilizing the G4 structures within the c-MYC and BCL-2 promoter sequences in vitro. Notably, when we evaluated by quantitative real-time PCR and western blotting analysis, the effects of treatment with the different G4 ligands on c-MYC and BCL2 expression in a human melanoma cell line, EMICORON appeared the most effective compound in reducing the mRNA and protein levels of both genes. These results encourage to consider EMICORON as a promising example of multimodal class of an antineoplastic drug, affecting different tumor crucial pathways simultaneously: telomere maintenance (as previously described), cell proliferation and apoptosis via down-regulation of both c-MYC and BCL-2 (this paper). PMID:27086081

  12. Low Expression of miR-196b Enhances the Expression of BCR-ABL1 and HOXA9 Oncogenes in Chronic Myeloid Leukemogenesis

    PubMed Central

    Liu, Yue; Zheng, Wenling; Song, Yanbin; Ma, Wenli; Yin, Hong

    2013-01-01

    MicroRNAs (miRNAs) can function as tumor suppressors or oncogene promoters during tumor development. In this study, low levels of expression of miR-196b were detected in patients with chronic myeloid leukemia. Bisulfite genomic sequencing PCR and methylation-specific PCR were used to examine the methylation status of the CpG islands in the miR-196b promoter in K562 cells, patients with leukemia and healthy individuals. The CpG islands showed more methylation in patients with chronic myeloid leukemia compared with healthy individuals (P<0.05), which indicated that low expression of miR-196b may be associated with an increase in the methylation of CpG islands. The dual-luciferase reporter assay system demonstrated that BCR-ABL1 and HOXA9 are the target genes of miR-196b, which was consistent with predictions from bioinformatics software analyses. Further examination of cell function indicated that miR-196b acts to reduce BCR-ABL1 and HOXA9 protein levels, decrease cell proliferation rate and retard the cell cycle. A low level of expression of miR-196b can cause up-regulation of BCR-ABL1 and HOXA9 expression, which leads to the development of chronic myeloid leukemia. MiR-196b may represent an effective target for chronic myeloid leukemia therapy. PMID:23894305

  13. 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.

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

    PubMed Central

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

    2016-01-01

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

  15. E2F-Rb Complexes Assemble and Inhibit cdc25A Transcription in Cervical Carcinoma Cells following Repression of Human Papillomavirus Oncogene Expression

    PubMed Central

    Wu, Lingling; Goodwin, Edward C.; Naeger, Lisa Kay; Vigo, Elena; Galaktionov, Konstantin; Helin, Kristian; DiMaio, Daniel

    2000-01-01

    Expression of the bovine papillomavirus E2 protein in cervical carcinoma cells represses expression of integrated human papillomavirus (HPV) E6/E7 oncogenes, followed by repression of the cdc25A gene and other cellular genes required for cell cycle progression, resulting in dramatic growth arrest. To explore the mechanism of repression of cell cycle genes in cervical carcinoma cells following E6/E7 repression, we analyzed regulation of the cdc25A promoter, which contains two consensus E2F binding sites and a consensus E2 binding site. The wild-type E2 protein inhibited expression of a luciferase gene linked to the cdc25A promoter in HT-3 cervical carcinoma cells. Mutation of the distal E2F binding site in the cdc25A promoter abolished E2-induced repression, whereas mutation of the proximal E2F site or the E2 site had no effect. None of these mutations affected the activity of the promoter in the absence of E2 expression. Expression of the E2 protein also led to posttranscriptional increase in the level of E2F4, p105Rb, and p130 and induced the formation of nuclear E2F4-p130 and E2F4-p105Rb complexes. This resulted in marked rearrangement of the protein complexes that formed at the distal E2F site in the cdc25A promoter, including the replacement of free E2F complexes with E2F4-p105Rb complexes. These experiments indicated that repression of E2F-responsive promoters following HPV E6/E7 repression was mediated by activation of the Rb tumor suppressor pathway and the assembly of repressing E2F4-Rb DNA binding complexes. Importantly, these experiments revealed that HPV-induced alterations in E2F transcription complexes that occur during cervical carcinogenesis are reversed by repression of HPV E6/E7 expression. PMID:10982822

  16. Repression of CD24 surface protein expression by oncogenic Ras is relieved by inhibition of Raf but not MEK or PI3K

    PubMed Central

    Pallegar, Nikitha K.; Ayre, D. Craig; Christian, Sherri L.

    2015-01-01

    CD24 is a dynamically regulated cell surface protein. High expression of CD24 leads to progression of lung, prostrate, colon, and pancreatic cancers, among others. In contrast, low expression of CD24 leads to cell proliferation and metastasis of breast cancer stem cells (BCSCs). Activating mutations in Ras are found in 30% of all human cancers. Oncogenic Ras constitutively stimulates the Raf, PI3K, and Ral GDS signaling pathways, leading to cellular transformation. Previous studies have shown that expression of oncogenic Ras in breast cancer cells generates CD24− cells from CD24+ cells. However, the molecular mechanisms involved in the generation of CD24− cells were not determined. Here, we demonstrate that oncogenic Ras (RasV12) expression suppresses CD24 mRNA, protein, and promoter levels when expressed in NIH/3T3 cells. Furthermore, activation of only the Raf pathway was sufficient to downregulate CD24 mRNA and protein expression to levels similar to those seen in with RasV12 expression. In contrast, activation of the PI3K pathway downregulated mRNA expression with a partial effect on protein expression whereas activation of the RalGDS pathway only partially affected protein expression. Surprisingly, inhibition of MEK with U0126 only partially restored CD24 mRNA expression but not surface protein expression. In contrast, inhibition of Raf with sorafenib did not restore CD24 mRNA expression but significantly increased the proportion of RasV12 cells expressing CD24. Therefore, the Raf pathway is the major repressor of CD24 mRNA and protein expression, with PI3K also able to substantially inhibit CD24 expression. Moreover, these data indicate that the levels of CD24 mRNA and surface protein are independently regulated. Although inhibition of Raf by sorafenib only partially restored CD24 expression, sorafenib should still be considered as a potential therapeutic strategy to alter CD24 expression in CD24− cells, such as BCSCs. PMID:26301220

  17. Suppression of protein kinase C and nuclear oncogene expression as possible action mechanisms of cancer chemoprevention by Curcumin.

    PubMed

    Lin, Jen-Kun

    2004-07-01

    Curcumin (diferuloylmethane) is a major naturally-occurring polyphenol of Curcuma species, which is commonly used as a yellow coloring and flavoring agent in foods. Curcumin has shown anti-carcinogenic activity in animal models. Curcumin possesses anti-inflammatory activity and is a potent inhibitor of reactive oxygen-generating enzymes such as lipoxygenase/cyclooxygenase, xanthine dehydrogenase/oxidase and inducible nitric oxide synthase; and an effective inducer of heme oxygenase-1. Curcumin is also a potent inhibitor of protein kinase C (PKC), EGF(Epidermal growth factor)-receptor tyrosine kinase and IkappaB kinase. Subsequently, curcumin inhibits the activation of NF(nucleor factor)kappaB and the expressions of oncogenes including c-jun, c-fos, c-myc, NIK, MAPKs, ERK, ELK, PI3K, Akt, CDKs and iNOS. It is proposed that curcumin may suppress tumor promotion through blocking signal transduction pathways in the target cells. The oxidant tumor promoter TPA activates PKC by reacting with zinc thiolates present within the regulatory domain, while the oxidized form of cancer chemopreventive agent such as curcumin can inactivate PKC by oxidizing the vicinal thiols present within the catalytic domain. Recent studies indicated that proteasome-mediated degradation of cell proteins play a pivotal role in the regulation of several basic cellular processes including differentiation, proliferation, cell cycling, and apoptosis. It has been demonstrated that curcumin-induced apoptosis is mediated through the impairment of ubiquitin-proteasome pathway. Curcumin was first biotransformed to dihydrocurcumin and tetrahydrocurcumin and that these compounds subsequently were converted to monoglucuronide conjugates. These results suggest that curcumin-glucuronide, dihydrocurcumin-glucuronide, tetrahydrocurcumin-glucuronide and tetrahydrocurcumin are the major metabolites of curcumin in mice, rats and humans. PMID:15356994

  18. Development of a conditional liver tumor model by mifepristone-inducible Cre recombination to control oncogenic krasV12 expression in transgenic zebrafish

    PubMed Central

    Nguyen, Anh Tuan; Koh, Vivien; Spitsbergen, Jan M.; Gong, Zhiyuan

    2016-01-01

    Here we report a new transgenic expression system by combination of liver-specific expression, mifepristone induction and Cre-loxP recombination to conditionally control the expression of oncogenic krasV12. This transgenic system allowed expression of krasV12 specifically in the liver by a brief exposure of mifepristone to induce permanent genomic recombination mediated by the Cre-loxP system. We found that liver tumors were generally induced from multiple foci due to incomplete Cre-loxP recombination, thus mimicking naturally occurring human tumors resulting from one or a few mutated cells and clonal proliferation to form nodules. Similar to our earlier studies by both constitutive and inducible expression of the krasV12 oncogene, hepatocellular carcinoma (HCC) is the main type of liver tumor induced by krasV12 expression. Moreover, mixed tumors with hepatocellular adenoma and hepatoblastoma (HB) were also frequently observed. Molecular analyses also indicated similar increase of phosphorylated ERK1/2 in all types of liver tumors, but nuclear localization of β–catenin, a sign of malignant transformation, was found only in HCC and HB. Taken together, our new transgenic system reported in this study allows transgenic krasV12 expression specifically in the zebrafish liver only by a brief exposure of mifepristone to induce permanent genomic recombination mediated by the Cre-loxP system. PMID:26790949

  19. Prevention of tumor growth driven by PIK3CA and HPV oncogenes by targeting mTOR signaling with metformin in oral squamous carcinomas expressing OCT3

    PubMed Central

    Madera, Dmitri; Vitale-Cross, Lynn; Martin, Daniel; Schneider, Abraham; Molinolo, Alfredo A.; Gangane, Nitin; Carey, Thomas E.; McHugh, Jonathan B.; Komarck, Christine M.; Walline, Heather M.; William, William N.; Seethala, Raja R.; Ferris, Robert; Gutkind, J. Silvio

    2015-01-01

    Most head and neck squamous cell carcinomas (HNSCC) exhibit a persistent activation of the PI3K-mTOR signaling pathway. We have recently shown that metformin, an oral antidiabetic drug that is also used to treat lipodystrophy in HIV-infected (HIV+) individuals, diminishes mTOR activity and prevents the progression of chemically-induced experimental HNSCC premalignant lesions. Here, we explored the preclinical activity of metformin in HNSCCs harboring PIK3CA mutations and HPV oncogenes, both representing frequent HNSCC alterations, aimed at developing effective targeted preventive strategies. The biochemical and biological effects of metformin were evaluated in representative HNSCC cells expressing mutated PIK3CA or HPV oncogenes (HPV+). The oral delivery of metformin was optimized to achieve clinical relevant blood levels. Molecular determinants of metformin sensitivity were also investigated, and their expression levels examined in a large collection of HNSCC cases. We found that metformin inhibits mTOR signaling and tumor growth in HNSCC cells expressing mutated PIK3CA and HPV oncogenes, and that these activities require the expression of organic cation transporter 3 (OCT3/SLC22A3), a metformin uptake transporter. Co-expression of OCT3 and the mTOR pathway activation marker pS6 were observed in most HNSCC cases, including those arising in HIV+ patients. Activation of the PI3K-mTOR pathway is a widespread event in HNSCC, including HPV− and HPV+ lesions arising in HIV+ patients, all of which co-express OCT3. These observations may provide a rationale for the clinical evaluation of metformin to halt HNSCC development from precancerous lesions, including in HIV+ individuals at risk of developing HPV-associated cancers. PMID:25681087

  20. The Jak2V617F oncogene associated with myeloproliferative diseases requires a functional FERM domain for transformation and for expression of the Myc and Pim proto-oncogenes

    PubMed Central

    Wernig, Gerlinde; Gonneville, Jeffrey R.; Crowley, Brian J.; Rodrigues, Margret S.; Reddy, Mamatha M.; Hudon, Heidi E.; Walz, Christoph; Reiter, Andreas; Podar, Klaus; Royer, Yohan; Constantinescu, Stefan N.; Tomasson, Michael H.; Griffin, James D.; Gilliland, D. Gary

    2008-01-01

    The V617F activating point mutation in Jak2 is associated with a proportion of myeloproliferative disorders. In normal hematopoietic cells, Jak2 signals only when associated with a growth factor receptor, such as the erythropoietin receptor (EpoR). We sought to identify the molecular requirements for activation of Jak2V617F by introducing a point mutation in the FERM domain (Y114A), required for receptor binding. Whereas BaF3.EpoR cells are readily transformed by Jak2V617F to Epo independence, we found that the addition of the FERM domain mutation blocked transformation and the induction of reactive oxygen species. Further, while cells expressing Jak2V617F had constitutive activation of STAT5, cells expressing Jak2V617F/Y114A did not, suggesting that signaling is defective at a very proximal level. In addition, expression of the Myc and Pim proto-oncogenes by Jak2V617F was found to be FERM domain dependent. An inducible constitutively active STAT5 mutant expressed in BaF3 cells was sufficient to induce Myc and Pim. Finally, the FERM domain in Jak2V617F was also required for abnormal hematopoiesis in transduced primary murine fetal liver cells. Overall, our results suggest that constitutive activation of Jak2 requires an intact FERM domain for a transforming phenotype, and is necessary for activation of the major target of Jak2, STAT5. PMID:18216297

  1. Prevention of tumor growth driven by PIK3CA and HPV oncogenes by targeting mTOR signaling with metformin in oral squamous carcinomas expressing OCT3.

    PubMed

    Madera, Dmitri; Vitale-Cross, Lynn; Martin, Daniel; Schneider, Abraham; Molinolo, Alfredo A; Gangane, Nitin; Carey, Thomas E; McHugh, Jonathan B; Komarck, Christine M; Walline, Heather M; William, William N; Seethala, Raja R; Ferris, Robert L; Gutkind, J Silvio

    2015-03-01

    Most squamous cell carcinomas of the head and neck (HNSCC) exhibit a persistent activation of the PI3K-mTOR signaling pathway. We have recently shown that metformin, an oral antidiabetic drug that is also used to treat lipodystrophy in HIV-infected (HIV(+)) individuals, diminishes mTOR activity and prevents the progression of chemically induced experimental HNSCC premalignant lesions. Here, we explored the preclinical activity of metformin in HNSCCs harboring PIK3CA mutations and HPV oncogenes, both representing frequent HNSCC alterations, aimed at developing effective targeted preventive strategies. The biochemical and biologic effects of metformin were evaluated in representative HNSCC cells expressing mutated PIK3CA or HPV oncogenes (HPV(+)). The oral delivery of metformin was optimized to achieve clinical relevant blood levels. Molecular determinants of metformin sensitivity were also investigated, and their expression levels were examined in a large collection of HNSCC cases. We found that metformin inhibits mTOR signaling and tumor growth in HNSCC cells expressing mutated PIK3CA and HPV oncogenes, and that these activities require the expression of organic cation transporter 3 (OCT3/SLC22A3), a metformin uptake transporter. Coexpression of OCT3 and the mTOR pathway activation marker pS6 were observed in most HNSCC cases, including those arising in HIV(+) patients. Activation of the PI3K-mTOR pathway is a widespread event in HNSCC, including HPV(-) and HPV(+) lesions arising in HIV(+) patients, all of which coexpress OCT3. These observations may provide a rationale for the clinical evaluation of metformin to halt HNSCC development from precancerous lesions, including in HIV(+) individuals at risk of developing HPV(-) associated cancers. PMID:25681087

  2. Oncogenic Activities of Human Papillomaviruses

    PubMed Central

    McLaughlin-Drubin, Margaret E.; Münger, Karl

    2009-01-01

    Infectious etiologies for certain human cancers have long been suggested by epidemiological studies and studies with animals. Important support for this concept came from the discovery by Harald zur Hausen’s group that human cervical carcinoma almost universally contains certain “high-risk” human papillomavirus (HPV) types. Over the years, much has been learned about the carcinogenic activities of high-risk HPVs. These studies have revealed that two viral proteins, E6 and E7, that are consistently expressed in HPV-associated carcinomas, are necessary for induction and maintenance of the transformed phenotype. Hence, HPV-associated tumors are unique amongst human solid tumors in that they are universally caused by exposure to the same, molecularly defined oncogenic agents, and the molecular signal transduction pathways subverted by these viral transforming agents are frequently disrupted in other, non-virus associated human cancers. PMID:19540281

  3. Soy isoflavone genistein modulates cell cycle progression and induces apoptosis in HER-2/neu oncogene expressing human breast epithelial cells.

    PubMed

    Katdare, Meena; Osborne, Michael; Telang, Nitin T

    2002-10-01

    In the multistep progressive pathogenesis of human breast cancer, comedo ductal carcinoma in situ (DCIS) represents a preinvasive precursor lesion for therapy resistant invasive cancer. Human tissue derived cell culture models exhibiting molecular similarities to clinical DCIS facilitate an important preclinical mechanistic approach for evaluation of preventive efficacy of natural and synthetic chemopreventive compounds. Natural phytochemicals present in fresh fruits, vegetables and grain products are likely to offer protection against cancer. The clinical efficacy of these natural phytochemicals, however, depends on extrapolation, and is therefore equivocal. The present study determined whether the natural soy isoflavone genistein (GEN) inhibited aberrant proliferation in 184-B5/HER cells (a model for human comedo DCIS) and identified possible mechanisms responsible for its efficacy. Human reduction mammoplasty derived HER-2/neu oncogene expressing preneoplastic 184-B5/HER cells represented the experimental system. Flow cytometry and cellular epifluorescence based assays were utilized to quantitate the alterations in cell cycle progression, cellular apoptosis, and in the status of cell cycle regulatory and apoptosis-associated gene product expression. The 184-B5/HER cells exhibited specific immunofluorescence to p185HER, p53, EGFR, but not to ERalpha, thus resembling comedo DCIS. Treatment of 184-B5/HER cells with GEN resulted in a dose-dependent decrease in the viable cell population, increase in the G0/G1:S + G2/M ratio and enhancement of sub G0/G1 (apoptotic population). Exposure to the maximum cytostatic 10 microM dose of GEN down-regulated HER-2/neu mediated signal transduction as evidenced by a 73.9% decrease (p=0.001) in p185HER specific, and a 89.8% decrease (p=0.001) in phosphotyrosine specific immunofluorescence. The increase in G0/G1:S + G2/M ratio in response to the treatment with 10 microM GEN was associated with a 85.5% decrease (p=0.001) in

  4. Hematopoietic expression of oncogenic BRAF promotes aberrant growth of monocyte-lineage cells resistant to PLX4720

    PubMed Central

    Kamata, Tamihiro; Dankort, David; Kang, Jing; Giblett, Susan; Pritchard, Catrin A.; McMahon, Martin; Leavitt, Andrew D.

    2013-01-01

    Mutational activation of BRAF leading to expression of the BRAFV600E oncoprotein was recently identified in a high percentage of specific hematopoietic neoplasms in monocyte/histiocyte and mature B-cell lineages. Although BRAFV600E is a driver oncoprotein and pharmacological target in solid tumors such as melanoma, lung and thyroid cancer, it remains unknown whether BRAFV600E is an appropriate therapeutic target in hematopoietic neoplasms. To address this critical question, we generated a mouse model expressing inducible BRAFV600E in the hematopoietic system, and evaluated the efficacy of pathway-targeted therapeutics against primary hematopoietic cells. In this model, BRAFV600E expression conferred cytokine-independent growth to monocyte/macrophage-lineage progenitors leading to aberrant in vivo and in vitro monocyte/macrophage expansion. Furthermore, transplantation of BRAFV600E-expressing bone marrow cells promoted an in vivo pathology most notable for monocytosis in hematopoietic tissues and visceral organs. In vitro analysis revealed that MEK inhibition, but not RAF inhibition, effectively suppressed cytokine-independent clonal growth of monocyte/macrophage-lineage progenitors. However, combined RAF and PI3K inhibition effectively inhibited cytokine-independent colony formation, suggesting autocrine PI3K pathway activation. Taken together, these results provide evidence that constitutively activated BRAFV600E drives aberrant proliferation of monocyte-lineage cells. This study supports the development of pathway-targeted therapeutics in the treatment of BRAFV600E-expressing hematopoietic neoplasms in the monocyte/histiocyte lineage. PMID:24152792

  5. Global gene expression changes of in vitro stimulated human transformed germinal centre B cells as surrogate for oncogenic pathway activation in individual aggressive B cell lymphomas

    PubMed Central

    2012-01-01

    Background Aggressive Non-Hodgkin lymphomas (NHL) are a group of lymphomas derived from germinal centre B cells which display a heterogeneous pattern of oncogenic pathway activation. We postulate that specific immune response associated signalling, affecting gene transcription networks, may be associated with the activation of different oncogenic pathways in aggressive Non-Hodgkin lymphomas (NHL). Methodology The B cell receptor (BCR), CD40, B-cell activating factor (BAFF)-receptors and Interleukin (IL) 21 receptor and Toll like receptor 4 (TLR4) were stimulated in human transformed germinal centre B cells by treatment with anti IgM F(ab)2-fragments, CD40L, BAFF, IL21 and LPS respectively. The changes in gene expression following the activation of Jak/STAT, NF-кB, MAPK, Ca2+ and PI3K signalling triggered by these stimuli was assessed using microarray analysis. The expression of top 100 genes which had a change in gene expression following stimulation was investigated in gene expression profiles of patients with Aggressive non-Hodgkin Lymphoma (NHL). Results αIgM stimulation led to the largest number of changes in gene expression, affecting overall 6596 genes. While CD40L stimulation changed the expression of 1194 genes and IL21 stimulation affected 902 genes, only 283 and 129 genes were modulated by lipopolysaccharide or BAFF receptor stimulation, respectively. Interestingly, genes associated with a Burkitt-like phenotype, such as MYC, BCL6 or LEF1, were affected by αIgM. Unique and shared gene expression was delineated. NHL-patients were sorted according to their similarity in the expression of TOP100 affected genes to stimulated transformed germinal centre B cells The αIgM gene module discriminated individual DLBCL in a similar manner to CD40L or IL21 gene modules. DLBCLs with low module activation often carry chromosomal MYC aberrations. DLBCLs with high module activation show strong expression of genes involved in cell-cell communication, immune responses

  6. Common and overlapping oncogenic pathways contribute to the evolution of acute myeloid leukemias

    PubMed Central

    Kvinlaug, Brynn T; Chan, Wai-In; Bullinger, Lars; Ramaswami, Mukundhan; Sears, Christopher; Foster, Donna; Lazic, Stanley E; Okabe, Rachel; Benner, Axel; Lee, Benjamin H; De Silva, Inusha; Valk, Peter JM; Delwel, Ruud; Armstrong, Scott A; Döhner, Hartmut; Gilliland, D Gary; Huntly, Brian JP

    2011-01-01

    Fusion oncogenes in acute myeloid leukemia (AML) promote self-renewal from committed progenitors, thereby linking transformation and self-renewal pathways. Like most cancers, AML is a genetically and biologically heterogeneous disease, but it is unclear whether transformation results from common or overlapping genetic programs acting downstream of multiple mutations, or by the engagement of unique genetic programs acting cooperatively downstream of individual mutations. This distinction is important, because the involvement of common programs would imply the existence of common molecular targets to treat AML, no matter which fusion oncogenes are involved. Here we demonstrate that the ability to promote self-renewal is a generalized property of leukemia-associated oncogenes. Disparate oncogenes initiated overlapping transformation and self-renewal gene expression programs, the common elements of which were defined in established leukemia stem cells from an animal model as well as from a large cohort of patients with differing AML subtypes, where they strongly predicted pathobiological character. Notably, individual genes commonly activated in these programs could partially phenocopy the self-renewal function of leukemia-associated oncogenes in committed murine progenitors. Further, they could generate AML following expression in murine bone marrow. In summary, our findings reveal the operation of common programs of self-renewal and transformation downstream of leukemia-associated oncogenes, suggesting mechanistically common therapeutic approaches to AML are likely to be possible, regardless of the identity of the driver oncogene involved. PMID:21505102

  7. Targeted Disruption of the Murine fps/fes Proto-Oncogene Reveals that Fps/Fes Kinase Activity Is Dispensable for Hematopoiesis

    PubMed Central

    Senis, Yotis; Zirngibl, Ralph; McVeigh, Jennifer; Haman, Andre; Hoang, Trang; Greer, Peter A.

    1999-01-01

    The fps/fes proto-oncogene encodes a cytoplasmic protein-tyrosine kinase that is functionally implicated in the survival and terminal differentiation of myeloid progenitors and in signaling from several members of the cytokine receptor superfamily. To gain further insight into the physiological function of fps/fes, we targeted the mouse locus with a kinase-inactivating missense mutation. Mutant Fps/Fes protein was expressed at normal levels in these mice, but it lacked detectable kinase activity. Homozygous mutant animals were viable and fertile, and they showed no obvious defects. Flow cytometry analysis of bone marrow showed no statistically significant differences in the levels of myeloid, erythroid, or B-cell precursors. Subtle abnormalities observed in mutant mice included slightly elevated total leukocyte counts and splenomegaly. In bone marrow hematopoietic progenitor cell colony-forming assays, mutant mice gave slightly elevated numbers and variable sizes of CFU-granulocyte macrophage in response to interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Tyrosine phosphorylation of Stat3 and Stat5A in bone marrow-derived macrophages was dramatically reduced in response to GM-CSF but not to IL-3 or IL-6. This suggests a distinct nonredundant role for Fps/Fes in signaling from the GM-CSF receptor that does not extend to the closely related IL-3 receptor. Lipopolysaccharide-induced Erk1/2 activation was also reduced in mutant macrophages. These subtle molecular phenotypes suggest a possible nonredundant role for Fps/Fes in myelopoiesis and immune responses. PMID:10523632

  8. Hierarchical Clustering of Breast Cancer Methylomes Revealed Differentially Methylated and Expressed Breast Cancer Genes

    PubMed Central

    Lin, I-Hsuan; Chen, Dow-Tien; Chang, Yi-Feng; Lee, Yu-Ling; Su, Chia-Hsin; Cheng, Ching; Tsai, Yi-Chien; Ng, Swee-Chuan; Chen, Hsiao-Tan; Lee, Mei-Chen; Chen, Hong-Wei; Suen, Shih-Hui; Chen, Yu-Cheng; Liu, Tze-Tze; Chang, Chuan-Hsiung; Hsu, Ming-Ta

    2015-01-01

    Oncogenic transformation of normal cells often involves epigenetic alterations, including histone modification and DNA methylation. We conducted whole-genome bisulfite sequencing to determine the DNA methylomes of normal breast, fibroadenoma, invasive ductal carcinomas and MCF7. The emergence, disappearance, expansion and contraction of kilobase-sized hypomethylated regions (HMRs) and the hypomethylation of the megabase-sized partially methylated domains (PMDs) are the major forms of methylation changes observed in breast tumor samples. Hierarchical clustering of HMR revealed tumor-specific hypermethylated clusters and differential methylated enhancers specific to normal or breast cancer cell lines. Joint analysis of gene expression and DNA methylation data of normal breast and breast cancer cells identified differentially methylated and expressed genes associated with breast and/or ovarian cancers in cancer-specific HMR clusters. Furthermore, aberrant patterns of X-chromosome inactivation (XCI) was found in breast cancer cell lines as well as breast tumor samples in the TCGA BRCA (breast invasive carcinoma) dataset. They were characterized with differentially hypermethylated XIST promoter, reduced expression of XIST, and over-expression of hypomethylated X-linked genes. High expressions of these genes were significantly associated with lower survival rates in breast cancer patients. Comprehensive analysis of the normal and breast tumor methylomes suggests selective targeting of DNA methylation changes during breast cancer progression. The weak causal relationship between DNA methylation and gene expression observed in this study is evident of more complex role of DNA methylation in the regulation of gene expression in human epigenetics that deserves further investigation. PMID:25706888

  9. E2F1 expression is deregulated and plays an oncogenic role in sporadic Burkitt’s lymphoma

    PubMed Central

    Molina-Privado, Irene; Rodríguez-Martínez, María; Rebollo, Patricia; Martín-Pérez, Daniel; Artiga, María-Jesús; Menárguez, Javier; Flemington, Erik K.; Piris, Miguel A.; Campanero, Miguel R.

    2009-01-01

    Current treatments of sBL are associated with severe toxicities. A better understanding of sBL formation would facilitate development of less toxic therapies. The etiology of sporadic Burkitt’s lymphoma (sBL) remains however largely unknown, being C-MYC up-regulation the only lesion known to occur in all sBL cases. Several studies examining the role of C-MYC in the pathogenesis of BL have concluded that C-MYC translocation is not the only critical event and that additional unidentified factors are expected to be involved in the formation of this tumor. We herein report that a gene distinct from C-MYC, E2F1, is involved in the formation of all or most sBL tumors. We found that E2F1 is highly expressed in Burkitt’s lymphoma cell lines and sBL lymphoma specimens. Our data indicate that its elevated expression is not merely the consequence of the presence of more cycling cells in this tumor relative to other cell lines or to other neoplasias. In fact, we show that reduction of its expression in sBL cells inhibits tumor formation and decreases their proliferation rate. We also provide data suggesting that E2F1 collaborates with C-MYC in sBL formation. E2F1 expression down-regulation did not affect, however, proliferation of human primary diploid fibroblasts. Since E2F1 is not needed for cell proliferation of normal cells, our results reveal E2F1 as a promising therapeutic target for sBL. PMID:19406837

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

    PubMed

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

    2013-01-01

    Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs). Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression. PMID:24152439

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

    PubMed Central

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

    2013-01-01

    Acidosis is a biochemical hallmark of the tumor microenvironment. Here, we report that acute acidosis decreases c-Myc oncogene expression in U937 human lymphoma cells. The level of c-Myc transcripts, but not mRNA or protein stability, contributes to c-Myc protein reduction under acidosis. The pH-sensing receptor TDAG8 (GPR65) is involved in acidosis-induced c-Myc downregulation. TDAG8 is expressed in U937 lymphoma cells, and the overexpression or knockdown of TDAG8 further decreases or partially rescues c-Myc expression, respectively. Acidic pH alone is insufficient to reduce c-Myc expression, as it does not decrease c-Myc in H1299 lung cancer cells expressing very low levels of pH-sensing G protein-coupled receptors (GPCRs). Instead, c-Myc is slightly increased by acidosis in H1299 cells, but this increase is completely inhibited by ectopic overexpression of TDAG8. Interestingly, TDAG8 expression is decreased by more than 50% in human lymphoma samples in comparison to non-tumorous lymph nodes and spleens, suggesting a potential tumor suppressor function of TDAG8 in lymphoma. Collectively, our results identify a novel mechanism of c-Myc regulation by acidosis in the tumor microenvironment and indicate that modulation of TDAG8 and related pH-sensing receptor pathways may be exploited as a new approach to inhibit Myc expression. PMID:24152439

  12. Oncogene activation and tumor suppressor gene inactivation find their sites of expression in the changes in time and space of the age-adjusted cancer incidence rate.

    PubMed

    Kodama, M; Kodama, T; Murakami, M

    2000-01-01

    profile in which the correlation coefficient r, a measure of fitness to the 2 equilibrium models, is converted to either +(r > 0) or -(0 > r) for each of the original-, the Rect-, and the Para-coordinates was found to be informative in identifying a group of tumors with sex discrimination of cancer risk (log AAIR changes in space) or another group of environmental hormone-linked tumors (log AAIR changes in time and space)--a finding to indicate that the r-profile of a given tumor, when compared with other neoplasias, may provide a clue to investigating the biological behavior of the tumor. 4) The recent risk increase of skin cancer of both sexes, being classified as an example of environmental hormone-linked neoplasias, was found to commit its ascension of cancer risk along the direction of the centrifugal forces of the time- and space-linked tumor suppressor gene inactivation plotted in the 2-dimension diagram. In conclusion, the centripetal force of oncogene activation and centrifugal force of tumor suppressor gene inactivation found their sites of expression in the distribution pattern of a cancer risk parameter, log AAIR, of a given neoplasias of both sexes on the 2-dimension diagram. The application of the least square method of Gauss to the log AAIR changes in time and space, and also with and without topological modulations of the original sets, when presented in terms of the r-profile, was found to be informative in understanding behavioral characteristics of human neoplaisias. PMID:11204489

  13. Tobacco exposure results in increased E6 and E7 oncogene expression, DNA damage and mutation rates in cells maintaining episomal human papillomavirus 16 genomes

    PubMed Central

    Wei, Lanlan; Griego, Anastacia M.; Chu, Ming; Ozbun, Michelle A.

    2014-01-01

    High-risk human papillomavirus (HR-HPV) infections are necessary but insufficient agents of cervical and other epithelial cancers. Epidemiological studies support a causal, but ill-defined, relationship between tobacco smoking and cervical malignancies. In this study, we used mainstream tobacco smoke condensate (MSTS-C) treatments of cervical cell lines that maintain either episomal or integrated HPV16 or HPV31 genomes to model tobacco smoke exposure to the cervical epithelium of the smoker. MSTS-C exposure caused a dose-dependent increase in viral genome replication and correspondingly higher early gene transcription in cells with episomal HPV genomes. However, MSTS-C exposure in cells with integrated HR-HPV genomes had no effect on genome copy number or early gene transcription. In cells with episomal HPV genomes, the MSTS-C-induced increases in E6 oncogene transcription led to decreased p53 protein levels and activity. As expected from loss of p53 activity in tobacco-exposed cells, DNA strand breaks were significantly higher but apoptosis was minimal compared with cells containing integrated viral genomes. Furthermore, DNA mutation frequencies were higher in surviving cells with HPV episomes. These findings provide increased understanding of tobacco smoke exposure risk in HPV infection and indicate tobacco smoking acts more directly to alter HR-HPV oncogene expression in cells that maintain episomal viral genomes. This suggests a more prominent role for tobacco smoke in earlier stages of HPV-related cancer progression. PMID:25064354

  14. Four not six: Revealing culturally common facial expressions of emotion.

    PubMed

    Jack, Rachael E; Sun, Wei; Delis, Ioannis; Garrod, Oliver G B; Schyns, Philippe G

    2016-06-01

    As a highly social species, humans generate complex facial expressions to communicate a diverse range of emotions. Since Darwin's work, identifying among these complex patterns which are common across cultures and which are culture-specific has remained a central question in psychology, anthropology, philosophy, and more recently machine vision and social robotics. Classic approaches to addressing this question typically tested the cross-cultural recognition of theoretically motivated facial expressions representing 6 emotions, and reported universality. Yet, variable recognition accuracy across cultures suggests a narrower cross-cultural communication supported by sets of simpler expressive patterns embedded in more complex facial expressions. We explore this hypothesis by modeling the facial expressions of over 60 emotions across 2 cultures, and segregating out the latent expressive patterns. Using a multidisciplinary approach, we first map the conceptual organization of a broad spectrum of emotion words by building semantic networks in 2 cultures. For each emotion word in each culture, we then model and validate its corresponding dynamic facial expression, producing over 60 culturally valid facial expression models. We then apply to the pooled models a multivariate data reduction technique, revealing 4 latent and culturally common facial expression patterns that each communicates specific combinations of valence, arousal, and dominance. We then reveal the face movements that accentuate each latent expressive pattern to create complex facial expressions. Our data questions the widely held view that 6 facial expression patterns are universal, instead suggesting 4 latent expressive patterns with direct implications for emotion communication, social psychology, cognitive neuroscience, and social robotics. (PsycINFO Database Record PMID:27077757

  15. Modulation of EZH2 Expression by MEK-ERK or PI3K-AKT Signaling in Lung Cancer Is Dictated by Different KRAS Oncogene Mutations.

    PubMed

    Riquelme, Erick; Behrens, Carmen; Lin, Heather Y; Simon, George; Papadimitrakopoulou, Vassiliki; Izzo, Julie; Moran, Cesar; Kalhor, Neda; Lee, J Jack; Minna, John D; Wistuba, Ignacio I

    2016-02-01

    EZH2 overexpression promotes cancer by increasing histone methylation to silence tumor suppressor genes, but how EZH2 levels become elevated in cancer is not understood. In this study, we investigated the mechanisms by which EZH2 expression is regulated in non-small cell lung carcinoma cells by oncogenic KRAS. In cells harboring KRAS(G12C) and KRAS(G12D) mutations, EZH2 expression was modulated by MEK-ERK and PI3K/AKT signaling, respectively. Accordingly, MEK-ERK depletion decreased EZH2 expression in cells harboring the KRAS(G12C) mutation, whereas PI3K/AKT depletion decreased EZH2 expression, EZH2 phosphorylation, and STAT3 activity in KRAS(G12D)-mutant cell lines. Combined inhibition of EZH2 and MEK-ERK or PI3K/AKT increased the sensitivity of cells with specific KRAS mutations to MEK-ERK and PI3K/AKT-targeted therapies. Our work defines EZH2 as a downstream effector of KRAS signaling and offers a rationale for combining EZH2 inhibitory strategies with MEK-ERK- or PI3K/AKT-targeted therapies to treat lung cancer patients, as stratified into distinct treatment groups based on specific KRAS mutations. PMID:26676756

  16. Expression of an Oncogenic BARD1 Splice Variant Impairs Homologous Recombination and Predicts Response to PARP-1 Inhibitor Therapy in Colon Cancer.

    PubMed

    Ozden, Ozkan; Bishehsari, Faraz; Bauer, Jessica; Park, Seong-Hoon; Jana, Arundhati; Baik, Seung Hyun; Sporn, Judith C; Staudacher, Jonas J; Yazici, Cemal; Krett, Nancy; Jung, Barbara

    2016-01-01

    BRCA1-associated RING domain protein 1 (BARD1) stabilizes BRCA1 protein by forming a heterodimeric RING-RING complex, and impacts function of BRCA1, including homologous recombination (HR) repair. Although colon cancer cells usually express wild type BRCA1, presence of an oncogenic BARD1 splice variant (SV) in select cancers may render BRCA1 dysfunctional and allow cells to become sensitive to HR targeting therapies. We previously reported association of loss of full-length (FL) BARD1 with poor prognosis in colon cancer as well as expression of various BARD1 SVs with unknown function. Here we show that loss of BARD1 function through the expression of a BARD1 SV, BARD1β, results in a more malignant phenotype with decreased RAD51 foci formation, reduced BRCA1 E3 ubiquitin ligase activity, and decreased nuclear BRCA1 protein localization. BARD1β sensitizes colon cancer cells to poly ADP ribose polymerase 1 (PARP-1) inhibition even in a FL BRCA1 background. These results suggest that expression of BARD1β may serve as a future biomarker to assess suitability of colon cancers for HR targeting with PARP-1 inhibitors in treatment of advanced colon cancer. PMID:27197561

  17. Expression of an Oncogenic BARD1 Splice Variant Impairs Homologous Recombination and Predicts Response to PARP-1 Inhibitor Therapy in Colon Cancer

    PubMed Central

    Ozden, Ozkan; Bishehsari, Faraz; Bauer, Jessica; Park, Seong-Hoon; Jana, Arundhati; Baik, Seung Hyun; Sporn, Judith C.; Staudacher, Jonas J.; Yazici, Cemal; Krett, Nancy; Jung, Barbara

    2016-01-01

    BRCA1-associated RING domain protein 1 (BARD1) stabilizes BRCA1 protein by forming a heterodimeric RING-RING complex, and impacts function of BRCA1, including homologous recombination (HR) repair. Although colon cancer cells usually express wild type BRCA1, presence of an oncogenic BARD1 splice variant (SV) in select cancers may render BRCA1 dysfunctional and allow cells to become sensitive to HR targeting therapies. We previously reported association of loss of full-length (FL) BARD1 with poor prognosis in colon cancer as well as expression of various BARD1 SVs with unknown function. Here we show that loss of BARD1 function through the expression of a BARD1 SV, BARD1β, results in a more malignant phenotype with decreased RAD51 foci formation, reduced BRCA1 E3 ubiquitin ligase activity, and decreased nuclear BRCA1 protein localization. BARD1β sensitizes colon cancer cells to poly ADP ribose polymerase 1 (PARP-1) inhibition even in a FL BRCA1 background. These results suggest that expression of BARD1β may serve as a future biomarker to assess suitability of colon cancers for HR targeting with PARP-1 inhibitors in treatment of advanced colon cancer. PMID:27197561

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

    PubMed Central

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

    2015-01-01

    Specific types of human papillomaviruses (HPVs) cause cervical cancer. Cervical cancers exhibit aberrant cellular microRNA (miRNA) expression patterns. By genome-wide analyses, we investigate whether the intracellular and exosomal miRNA compositions of HPV-positive cancer cells are dependent on endogenous E6/E7 oncogene expression. Deep sequencing studies combined with qRT-PCR analyses show that E6/E7 silencing significantly affects ten of the 52 most abundant intracellular miRNAs in HPV18-positive HeLa cells, downregulating miR-17-5p, miR-186-5p, miR-378a-3p, miR-378f, miR-629-5p and miR-7-5p, and upregulating miR-143-3p, miR-23a-3p, miR-23b-3p and miR-27b-3p. The effects of E6/E7 silencing on miRNA levels are mainly not dependent on p53 and similarly observed in HPV16-positive SiHa cells. The E6/E7-regulated miRNAs are enriched for species involved in the control of cell proliferation, senescence and apoptosis, suggesting that they contribute to the growth of HPV-positive cancer cells. Consistently, we show that sustained E6/E7 expression is required to maintain the intracellular levels of members of the miR-17~92 cluster, which reduce expression of the anti-proliferative p21 gene in HPV-positive cancer cells. In exosomes secreted by HeLa cells, a distinct seven-miRNA-signature was identified among the most abundant miRNAs, with significant downregulation of let-7d-5p, miR-20a-5p, miR-378a-3p, miR-423-3p, miR-7-5p, miR-92a-3p and upregulation of miR-21-5p, upon E6/E7 silencing. Several of the E6/E7-dependent exosomal miRNAs have also been linked to the control of cell proliferation and apoptosis. This study represents the first global analysis of intracellular and exosomal miRNAs and shows that viral oncogene expression affects the abundance of multiple miRNAs likely contributing to the E6/E7-dependent growth of HPV-positive cancer cells. PMID:25760330

  19. Gene Expression Patterns of Hemizygous and Heterozygous KIT Mutations Suggest Distinct Oncogenic Pathways: A Study in NIH3T3 Cell Lines and GIST Samples

    PubMed Central

    Dessaux, Sophie; Besse, Anthony; Brahimi-Adouane, Sabrina; Emile, Jean-François; Blay, Jean-Yves; Alberti, Laurent

    2013-01-01

    Objective Most gain of function mutations of tyrosine kinase receptors in human tumours are hemizygous. Gastrointestinal stromal tumours (GIST) with homozygous mutations have a worse prognosis. We aimed to identify genes differentially regulated by hemizygous and heterozygous KIT mutations. Materials and Methods Expression of 94 genes and 384 miRNA was analysed with low density arrays in five NIH3T3 cell lines expressing the full-length human KIT cDNA wild-type (WT), hemizygous KIT mutation with del557-558 (D6) or del564-581 (D54) and heterozygous WT/D6 or WT/D54. Expression of 5 of these genes and 384 miRNA was then analysed in GISTs samples. Results Unsupervised and supervised hierarchical clustering of the mRNA and miRNA profiles showed that heterozygous mutants clustered with KIT WT expressing cells while hemizygous mutants were distinct. Among hemizygous cells, D6 and D54 expressing cells clustered separately. Most deregulated genes have been reported as potentially implicated in cancer and severals, as ANXA8 and FBN1, are highlighted by both, mRNA and miRNA analyses. MiRNA and mRNA analyses in GISTs samples confirmed that their expressions varied according to the mutation of the alleles. Interestingly, RGS16, a membrane protein of the regulator of G protein family, correlate with the subcellular localization of KIT mutants and might be responsible for regulation of the PI3K/AKT signalling pathway. Conclusion Patterns of mRNA and miRNA expression in cells and tumours depend on heterozygous/hemizygous status of KIT mutations, and deletion/presence of TYR568 & TYR570 residues. Thus each mutation of KIT may drive specific oncogenic pathways. PMID:23593401

  20. Functionalities of expressed messenger RNAs revealed from mutant phenotypes.

    PubMed

    Liao, Ben-Yang; Weng, Meng-Pin

    2016-07-01

    Total messenger RNAs mRNAs that are produced from a given gene under a certain set of conditions include both functional and nonfunctional transcripts. The high prevalence of nonfunctional mRNAs that have been detected in cells has raised questions regarding the functional implications of mRNA expression patterns and divergences. Phenotypes that result from the mutagenesis of protein-coding genes have provided the most straightforward descriptions of gene functions, and such data obtained from model organisms have facilitated investigations of the functionalities of expressed mRNAs. Mutant phenotype data from mouse tissues have revealed various attributes of functional mRNAs, including tissue-specificity, strength of expression, and evolutionary conservation. In addition, the role that mRNA expression evolution plays in driving morphological evolution has been revealed from studies designed to exploit morphological and physiological phenotypes of mouse mutants. Investigations into yeast essential genes (defined by an absence of colony growth after gene deletion) have further described gene regulatory strategies that reduce protein expression noise by mediating the rates of transcription and translation. In addition to the functional significance of expressed mRNAs as described in the abovementioned findings, the functionalities of other type of RNAs (i.e., noncoding RNAs) remain to be characterized with systematic mutations and phenotyping of the DNA regions that encode these RNA molecules. WIREs RNA 2016, 7:416-427. doi: 10.1002/wrna.1329 For further resources related to this article, please visit the WIREs website. PMID:26748449

  1. The DEK oncogene activates VEGF expression and promotes tumor angiogenesis and growth in HIF-1α-dependent and -independent manners.

    PubMed

    Zhang, Yanan; Liu, Jie; Wang, Shibin; Luo, Xiaoli; Li, Yang; Lv, Zhaohui; Zhu, Jie; Lin, Jing; Ding, Lihua; Ye, Qinong

    2016-04-26

    The DEK oncogene is overexpressed in various cancers and overexpression of DEK correlates with poor clinical outcome. Vascular endothelial growth factor (VEGF) is the most important regulator of tumor angiogenesis, a process essential for tumor growth and metastasis. However, whether DEK enhances tumor angiogenesis remains unclear. Here, we show that DEK is a key regulator of VEGF expression and tumor angiogenesis. Using chromatin immunoprecipitation assay, we found that DEK promoted VEGF transcription in breast cancer cells (MCF7, ZR75-1 and MDA-MB-231) by directly binding to putative DEK-responsive element (DRE) of the VEGF promoter and indirectly binding to hypoxia response element (HRE) upstream of the DRE through its interaction with the transcription factor hypoxia-inducible factor 1α (HIF-1α), a master regulator of tumor angiogenesis and growth. DEK is responsible for recruitment of HIF-1α and the histone acetyltransferase p300 to the VEGF promoter. DEK-enhanced VEGF increases vascular endothelial cell proliferation, migration and tube formation as well as angiogenesis in the chick chorioallantoic membrane. DEK promotes tumor angiogenesis and growth in nude mice in HIF-1α-dependent and -independent manners. Immunohistochemical staining showed that DEK expression positively correlates with the expression of VEGF and microvessel number in 58 breast cancer patients. Our data establish DEK as a sequence-specific binding transcription factor, a novel coactivator for HIF-1α in regulation of VEGF transcription and a novel promoter of angiogenesis. PMID:26988756

  2. A high level of liver-specific expression of oncogenic Kras(V12) drives robust liver tumorigenesis in transgenic zebrafish.

    PubMed

    Nguyen, Anh Tuan; Emelyanov, Alexander; Koh, Chor Hui Vivien; Spitsbergen, Jan M; Lam, Siew Hong; Mathavan, Sinnakaruppan; Parinov, Serguei; Gong, Zhiyuan

    2011-11-01

    Human liver cancer is one of the deadliest cancers worldwide, with hepatocellular carcinoma (HCC) being the most common type. Aberrant Ras signaling has been implicated in the development and progression of human HCC, but a complete understanding of the molecular mechanisms of this protein in hepatocarcinogenesis remains elusive. In this study, a stable in vivo liver cancer model using transgenic zebrafish was generated to elucidate Ras-driven tumorigenesis in HCC. Using the liver-specific fabp10 (fatty acid binding protein 10) promoter, we overexpressed oncogenic kras(V12) specifically in the transgenic zebrafish liver. Only a high level of kras(V12) expression initiated liver tumorigenesis, which progressed from hyperplasia to benign and malignant tumors with activation of the Ras-Raf-MEK-ERK and Wnt-β-catenin pathways. Histological diagnosis of zebrafish tumors identified HCC as the main lesion. The tumors were invasive and transplantable, indicating malignancy of these HCC cells. Oncogenic kras(V12) was also found to trigger p53-dependent senescence as a tumor suppressive barrier in the pre-neoplastic stage. Microarray analysis of zebrafish liver hyperplasia and HCC uncovered the deregulation of several stage-specific and common biological processes and signaling pathways responsible for kras(V12)-driven liver tumorigenesis that recapitulated the molecular hallmarks of human liver cancer. Cross-species comparisons of cancer transcriptomes further defined a HCC-specific gene signature as well as a liver cancer progression gene signature that are evolutionarily conserved between human and zebrafish. Collectively, our study presents a comprehensive portrait of molecular mechanisms during progressive Ras-induced HCC. These observations indicate the validity of our transgenic zebrafish to model human liver cancer, and this model might act as a useful platform for drug screening and identifying new therapeutic targets. PMID:21729876

  3. A high level of liver-specific expression of oncogenic KrasV12 drives robust liver tumorigenesis in transgenic zebrafish

    PubMed Central

    Nguyen, Anh Tuan; Emelyanov, Alexander; Koh, Chor Hui Vivien; Spitsbergen, Jan M.; Lam, Siew Hong; Mathavan, Sinnakaruppan; Parinov, Serguei; Gong, Zhiyuan

    2011-01-01

    SUMMARY Human liver cancer is one of the deadliest cancers worldwide, with hepatocellular carcinoma (HCC) being the most common type. Aberrant Ras signaling has been implicated in the development and progression of human HCC, but a complete understanding of the molecular mechanisms of this protein in hepatocarcinogenesis remains elusive. In this study, a stable in vivo liver cancer model using transgenic zebrafish was generated to elucidate Ras-driven tumorigenesis in HCC. Using the liver-specific fabp10 (fatty acid binding protein 10) promoter, we overexpressed oncogenic krasV12 specifically in the transgenic zebrafish liver. Only a high level of krasV12 expression initiated liver tumorigenesis, which progressed from hyperplasia to benign and malignant tumors with activation of the Ras-Raf-MEK-ERK and Wnt–β-catenin pathways. Histological diagnosis of zebrafish tumors identified HCC as the main lesion. The tumors were invasive and transplantable, indicating malignancy of these HCC cells. Oncogenic krasV12 was also found to trigger p53-dependent senescence as a tumor suppressive barrier in the pre-neoplastic stage. Microarray analysis of zebrafish liver hyperplasia and HCC uncovered the deregulation of several stage-specific and common biological processes and signaling pathways responsible for krasV12-driven liver tumorigenesis that recapitulated the molecular hallmarks of human liver cancer. Cross-species comparisons of cancer transcriptomes further defined a HCC-specific gene signature as well as a liver cancer progression gene signature that are evolutionarily conserved between human and zebrafish. Collectively, our study presents a comprehensive portrait of molecular mechanisms during progressive Ras-induced HCC. These observations indicate the validity of our transgenic zebrafish to model human liver cancer, and this model might act as a useful platform for drug screening and identifying new therapeutic targets. PMID:21729876

  4. TGIF function in oncogenic Wnt signaling.

    PubMed

    Razzaque, Mohammed S; Atfi, Azeddine

    2016-04-01

    Transforming growth-interacting factor (TGIF) has been implicated in the pathogenesis of many types of human cancer, but the underlying mechanisms remained mostly enigmatic. Our recent study has revealed that TGIF functions as a mediator of oncogenic Wnt/β-catenin signaling. We found that TGIF can interact with and sequesters Axin1 and Axin2 into the nucleus, thereby culminating in disassembly of the β-catenin-destruction complex and attendant accumulation of β-catenin in the nucleus, where it activates expression of Wnt target genes, including TGIF itself. We have provided proof-of-concept evidences that high levels of TGIF expression correlate with poor prognosis in patients with triple negative breast cancer (TNBC), and that TGIF empowers Wnt-driven mammary tumorigenesis in vivo. Here, we will briefly summarize how TGIF influences Wnt signaling to promote tumorigenesis. PMID:26522669

  5. Transcriptional expression of Epstein-Barr virus genes and proto-oncogenes in north African nasopharyngeal carcinoma.

    PubMed

    Sbih-Lammali, F; Djennaoui, D; Belaoui, H; Bouguermouh, A; Decaussin, G; Ooka, T

    1996-05-01

    Cases of nasopharyngeal carcinoma (NPC) from North Africa show an unusual bimodal age distribution. As elsewhere, the tumor is closely associated with the presence of Epstein-Barr virus (EBV). The expression of EBV genes and c-onc genes was studied in biopsy specimens from tumors at different clinical stages from 11 young (10 to 30-year-old) and 11 adult (30 to 65-year-old) patients. It was found that the two age groups do not differ in their pattern of gene expression, that there is a tendency for later stage biopsies to express more viral and c-onc transcripts, and that samples expressing larger numbers of EBV genes also tend to express many different c-onc specificities. PMID:8732865

  6. The proto-oncogene Myc drives expression of the NK cell-activating NKp30 ligand B7-H6 in tumor cells.

    PubMed

    Textor, Sonja; Bossler, Felicitas; Henrich, Kai-Oliver; Gartlgruber, Moritz; Pollmann, Julia; Fiegler, Nathalie; Arnold, Annette; Westermann, Frank; Waldburger, Nina; Breuhahn, Kai; Golfier, Sven; Witzens-Harig, Mathias; Cerwenka, Adelheid

    2016-07-01

    Natural Killer (NK) cells are innate effector cells that are able to recognize and eliminate tumor cells through engagement of their surface receptors. NKp30 is a potent activating NK cell receptor that elicits efficient NK cell-mediated target cell killing. Recently, B7-H6 was identified as tumor cell surface expressed ligand for NKp30. Enhanced B7-H6 mRNA levels are frequently detected in tumor compared to healthy tissues. To gain insight in the regulation of expression of B7-H6 in tumors, we investigated transcriptional mechanisms driving B7-H6 expression by promoter analyses. Using luciferase reporter assays and chromatin immunoprecipitation we mapped a functional binding site for Myc, a proto-oncogene overexpressed in certain tumors, in the B7-H6 promoter. Pharmacological inhibition or siRNA/shRNA-mediated knock-down of c-Myc or N-Myc significantly decreased B7-H6 expression on a variety of tumor cells including melanoma, pancreatic carcinoma and neuroblastoma cell lines. In tumor cell lines from different origin and primary tumor tissues of hepatocellular carcinoma (HCC), lymphoma and neuroblastoma, mRNA levels of c-Myc positively correlated with B7-H6 expression. Most importantly, upon inhibition or knock-down of c-Myc in tumor cells impaired NKp30-mediated degranulation of NK cells was observed. Thus, our data imply that Myc driven tumors could be targets for cancer immunotherapy exploiting the NKp30/B7-H6 axis. PMID:27622013

  7. Enforced expression of the c-myc oncogene inhibits cell differentiation by precluding entry into a distinct predifferentiation state in G/sub 0//G/sub 1/

    SciTech Connect

    Freytag, S.O.

    1988-04-01

    A broad base of data has implicated a role for the c-myc proto-oncogene in the control of the cell cycle and cell differentiation. To further define the role of myc in these processes, the authors examined the effect of enforced myc expression on several events that are thought to be important steps leading to the terminally differentiated state: (i) the ability to arrest growth in G/sub 0//G/sub 1/, (ii) the ability to replicate the genome upon initiation of the differentiation program, and (iii) the ability to loose responsiveness to mitogens and withdraw from the cell cycle. 3T3-L1 preadipocyte cell lines expressing various levels of myc mRNA were established by transfection with a recombinant myc gene under the transcriptional control of the Rous sarcoma virus (RSV) promoter. Cells that expressed high constitutive levels of pRSV myc mRNA arrested in G/sub 0//G/sub 1/ at densities similar to those of normal cells at confluence. Upon initiation of the differentiation program, such cells traversed the cell cycle with kinetics similar to those of normal cells and subsequently arrested in G/sub 0//G/sub 1/. Thus, enforced expression of myc had no effect on the ability of cells to arrest growth in G/sub 0//G/sub 1/ or to replicate the genome upon initiation of the differentiation program. Cells were then tested for their ability to reenter the cell cycle upon exposure to high concentrations of serum and for their capacity to differentiate. In contrast to normal cells, cells expressing high constitutive levels of myc RNA reentered the cell cycle when challenged with 30% serum and failed to terminally differentiate.

  8. Automatic decoding of facial movements reveals deceptive pain expressions

    PubMed Central

    Bartlett, Marian Stewart; Littlewort, Gwen C.; Frank, Mark G.; Lee, Kang

    2014-01-01

    Summary In highly social species such as humans, faces have evolved to convey rich information for social interaction, including expressions of emotions and pain [1–3]. Two motor pathways control facial movement [4–7]. A subcortical extrapyramidal motor system drives spontaneous facial expressions of felt emotions. A cortical pyramidal motor system controls voluntary facial expressions. The pyramidal system enables humans to simulate facial expressions of emotions not actually experienced. Their simulation is so successful that they can deceive most observers [8–11]. Machine vision may, however, be able to distinguish deceptive from genuine facial signals by identifying the subtle differences between pyramidally and extrapyramidally driven movements. Here we show that human observers could not discriminate real from faked expressions of pain better than chance, and after training, improved accuracy to a modest 55%. However a computer vision system that automatically measures facial movements and performs pattern recognition on those movements attained 85% accuracy. The machine system’s superiority is attributable to its ability to differentiate the dynamics of genuine from faked expressions. Thus by revealing the dynamics of facial action through machine vision systems, our approach has the potential to elucidate behavioral fingerprints of neural control systems involved in emotional signaling. PMID:24656830

  9. Hidden among the crowd: differential DNA methylation-expression correlations in cancer occur at important oncogenic pathways

    PubMed Central

    Mosquera Orgueira, Adrián

    2015-01-01

    DNA methylation is a frequent epigenetic mechanism that participates in transcriptional repression. Variations in DNA methylation with respect to gene expression are constant, and, for unknown reasons, some genes with highly methylated promoters are sometimes overexpressed. In this study we have analyzed the expression and methylation patterns of thousands of genes in five groups of cancer and normal tissue samples in order to determine local and genome-wide differences. We observed significant changes in global methylation-expression correlation in all the neoplasms, which suggests that differential correlation events are frequent in cancer. A focused analysis in the breast cancer cohort identified 1662 genes whose correlation varies significantly between normal and cancerous breast, but whose DNA methylation and gene expression patterns do not change substantially. These genes were enriched in cancer-related pathways and repressive chromatin features across various model cell lines, such as PRC2 binding and H3K27me3 marks. Substantial changes in methylation-expression correlation indicate that these genes are subject to epigenetic remodeling, where the differential activity of other factors break the expected relationship between both variables. Our findings suggest a complex regulatory landscape where a redistribution of local and large-scale chromatin repressive domains at differentially correlated genes (DCGs) creates epigenetic hotspots that modulate cancer-specific gene expression. PMID:26029238

  10. Tumor suppressor ASXL1 is essential for the activation of INK4B expression in response to oncogene activity and anti-proliferative signals.

    PubMed

    Wu, Xudong; Bekker-Jensen, Ida Holst; Christensen, Jesper; Rasmussen, Kasper Dindler; Sidoli, Simone; Qi, Yan; Kong, Yu; Wang, Xi; Cui, Yajuan; Xiao, Zhijian; Xu, Guogang; Williams, Kristine; Rappsilber, Juri; Sønderby, Casper Kaae; Winther, Ole; Jensen, Ole N; Helin, Kristian

    2015-11-01

    ASXL1 mutations are frequently found in hematological tumors, and loss of Asxl1 promotes myeloid transformation in mice. Here we present data supporting a role for an ASXL1-BAP1 complex in the deubiquitylation of mono-ubiquitylated lysine 119 on Histone H2A (H2AK119ub1) in vivo. The Polycomb group proteins control the expression of the INK4B-ARF-INK4A locus during normal development, in part through catalyzing mono-ubiquitylation of H2AK119. Since the activation of the locus INK4B-ARF-INK4A plays a fail-safe mechanism protecting against tumorigenesis, we investigated whether ASXL1-dependent H2A deubiquitylation plays a role in its activation. Interestingly, we found that ASXL1 is specifically required for the increased expression of p15(INK4B) in response to both oncogenic signaling and extrinsic anti-proliferative signals. Since we found that ASXL1 and BAP1 both are enriched at the INK4B locus, our results suggest that activation of the INK4B locus requires ASXL1/BAP1-mediated deubiquitylation of H2AK119ub1. Consistently, our results show that ASXL1 mutations are associated with lower expression levels of p15(INK4B) and a proliferative advantage of hematopoietic progenitors in primary bone marrow cells, and that depletion of ASXL1 in multiple cell lines results in resistance to growth inhibitory signals. Taken together, this study links ASXL1-mediated H2A deubiquitylation and transcriptional activation of INK4B expression to its tumor suppressor functions. PMID:26470845

  11. Redox-modulating agents target NOX2-dependent IKKε oncogenic kinase expression and proliferation in human breast cancer cell lines

    PubMed Central

    Mukawera, Espérance; Chartier, Stefany; Williams, Virginie; Pagano, Patrick J.; Lapointe, Réjean; Grandvaux, Nathalie

    2015-01-01

    Oxidative stress is considered a causative factor in carcinogenesis, but also in the development of resistance to current chemotherapies. The appropriate usage of redox-modulating compounds is limited by the lack of knowledge of their impact on specific molecular pathways. Increased levels of the IKKε kinase, as a result of gene amplification or aberrant expression, are observed in a substantial number of breast carcinomas. IKKε not only plays a key role in cell transformation and invasiveness, but also in the development of resistance to tamoxifen. Here, we studied the effect of in vitro treatment with the redox-modulating triphenylmethane dyes, Gentian Violet and Brilliant Green, and nitroxide Tempol on IKKε expression and cell proliferation in the human breast cancer epithelial cell lines exhibiting amplification of IKKε, MCF-7 and ZR75.1. We show that Gentian Violet, Brilliant Green and Tempol significantly decrease intracellular superoxide anion levels and inhibit IKKε expression and cell viability. Treatment with Gentian Violet and Brilliant Green was associated with a reduced cyclin D1 expression and activation of caspase 3 and/or 7. Tempol decreased cyclin D1 expression in both cell lines, while activation of caspase 7 was only observed in MCF-7 cells. Silencing of the superoxide-generating NOX2 NADPH oxidase expressed in breast cancer cells resulted in the significant reduction of IKKε expression. Taken together, our results suggest that redox-modulating compounds targeting NOX2 could present a particular therapeutic interest in combination therapy against breast carcinomas exhibiting IKKε amplification. PMID:26177467

  12. Redox-modulating agents target NOX2-dependent IKKε oncogenic kinase expression and proliferation in human breast cancer cell lines.

    PubMed

    Mukawera, Espérance; Chartier, Stefany; Williams, Virginie; Pagano, Patrick J; Lapointe, Réjean; Grandvaux, Nathalie

    2015-12-01

    Oxidative stress is considered a causative factor in carcinogenesis, but also in the development of resistance to current chemotherapies. The appropriate usage of redox-modulating compounds is limited by the lack of knowledge of their impact on specific molecular pathways. Increased levels of the IKKε kinase, as a result of gene amplification or aberrant expression, are observed in a substantial number of breast carcinomas. IKKε not only plays a key role in cell transformation and invasiveness, but also in the development of resistance to tamoxifen. Here, we studied the effect of in vitro treatment with the redox-modulating triphenylmethane dyes, Gentian Violet and Brilliant Green, and nitroxide Tempol on IKKε expression and cell proliferation in the human breast cancer epithelial cell lines exhibiting amplification of IKKε, MCF-7 and ZR75.1. We show that Gentian Violet, Brilliant Green and Tempol significantly decrease intracellular superoxide anion levels and inhibit IKKε expression and cell viability. Treatment with Gentian Violet and Brilliant Green was associated with a reduced cyclin D1 expression and activation of caspase 3 and/or 7. Tempol decreased cyclin D1 expression in both cell lines, while activation of caspase 7 was only observed in MCF-7 cells. Silencing of the superoxide-generating NOX2 NADPH oxidase expressed in breast cancer cells resulted in the significant reduction of IKKε expression. Taken together, our results suggest that redox-modulating compounds targeting NOX2 could present a particular therapeutic interest in combination therapy against breast carcinomas exhibiting IKKε amplification. PMID:26177467

  13. Mass spectrometry analysis of the oxidation states of the pro-oncogenic protein anterior gradient-2 reveals covalent dimerization via an intermolecular disulphide bond.

    PubMed

    Clarke, David J; Murray, Euan; Faktor, Jakub; Mohtar, Aiman; Vojtesek, Borek; MacKay, C Logan; Smith, Pat Langridge; Hupp, Ted R

    2016-05-01

    Anterior Gradient-2 (AGR2) is a component of a pro-oncogenic signalling pathway that can promote p53 inhibition, metastatic cell migration, limb regeneration, and cancer drug-resistance. AGR2 is in the protein-disulphide isomerase superfamily containing a single cysteine (Cys-81) that forms covalent adducts with its client proteins. We have found that mutation of Cysteine-81 attenuates its biochemical activity in its sequence-specific peptide docking function, reduces binding to Reptin, and reduces its stability in cells. As such, we evaluated how chemical oxidation of its cysteine affects its biochemical properties. Recombinant AGR2 spontaneously forms covalent dimers in the absence of reductant whilst DTT promotes dimer to monomer conversion. Mutation of Cysteine-81 to alanine prevents peroxide catalysed dimerization of AGR2 in vitro, suggesting a reactive cysteine is central to covalent dimer formation. Both biochemical assays and ESI mass spectrometry were used to demonstrate that low levels of a chemical oxidant promote an intermolecular disulphide bond through formation of a labile sulfenic acid intermediate. However, higher levels of oxidant promote sulfinic or sulfonic acid formation thus preventing covalent dimerization of AGR2. These data together identify the single cysteine of AGR2 as an oxidant responsive moiety that regulates its propensity for oxidation and its monomeric-dimeric state. This has implications for redox regulation of the pro-oncogenic functions of AGR2 protein in cancer cells. PMID:26876500

  14. Proto-oncogenes II.

    PubMed

    Rosen, P

    1988-12-01

    In reviewing recent literature on activated proto-oncogenes including retroviral infection (without oncogene), translocation and inherited childhood cancer, I have come to the conclusion that activated proto-oncogenes are not involved in development of tumors. There is one exception in which a translocated proto-myc leads to transformation. That is the case of the trangenic mouse embryo where faulty development occurs. PMID:3226361

  15. Expression of the glioma-associated oncogene homolog (GLI) 1 in human breast cancer is associated with unfavourable overall survival

    PubMed Central

    2009-01-01

    Background The transcription factor GLI1, a member of the GLI subfamily of Krüppel-like zinc finger proteins is involved in signal transduction within the hedgehog pathway. Aberrant hedgehog signalling has been implicated in the development of different human tumour entities such as colon and lung cancer and increased GLI1 expression has been found in these tumour entities as well. In this study we questioned whether GLI1 expression might also be important in human breast cancer development. Furthermore we correlated GLI1 expression with histopathological and clinical data to evaluate whether GLI1 could represent a new prognostic marker in breast cancer treatment. Methods Applying semiquantitative realtime PCR analysis and immunohistochemistry (IHC) GLI1 expression was analysed in human invasive breast carcinomas (n = 229) in comparison to normal human breast tissues (n = 58). GLI1 mRNA expression was furthermore analysed in a set of normal (n = 3) and tumourous breast cell lines (n = 8). IHC data were statistically interpreted using SPSS version 14.0. Results Initial analysis of GLI1 mRNA expression in a small cohort of (n = 5) human matched normal and tumourous breast tissues showed first tendency towards GLI1 overexpression in human breast cancers. However only a small sample number was included into these analyses and values for GLI1 overexpression were statistically not significant (P = 0.251, two-tailed Mann-Whitney U-test). On protein level, nuclear GLI1 expression in breast cancer cells was clearly more abundant than in normal breast epithelial cells (P = 0.008, two-tailed Mann-Whitney U-test) and increased expression of GLI1 protein in breast tumours significantly correlated with unfavourable overall survival (P = 0.019), but also with higher tumour stage (P < 0.001) and an increased number of tumour-positive axillar lymph nodes (P = 0.027). Interestingly, a highly significant correlation was found between GLI1 expression and the expression of SHH, a

  16. What Facial Appearance Reveals Over Time: When Perceived Expressions in Neutral Faces Reveal Stable Emotion Dispositions.

    PubMed

    Adams, Reginald B; Garrido, Carlos O; Albohn, Daniel N; Hess, Ursula; Kleck, Robert E

    2016-01-01

    It might seem a reasonable assumption that when we are not actively using our faces to express ourselves (i.e., when we display nonexpressive, or neutral faces), those around us will not be able to read our emotions. Herein, using a variety of expression-related ratings, we examined whether age-related changes in the face can accurately reveal one's innermost affective dispositions. In each study, we found that expressive ratings of neutral facial displays predicted self-reported positive/negative dispositional affect, but only for elderly women, and only for positive affect. These findings meaningfully replicate and extend earlier work examining age-related emotion cues in the face of elderly women (Malatesta et al., 1987a). We discuss these findings in light of evidence that women are expected to, and do, smile more than men, and that the quality of their smiles predicts their life satisfaction. Although ratings of old male faces did not significantly predict self-reported affective dispositions, the trend was similar to that found for old female faces. A plausible explanation for this gender difference is that in the process of attenuating emotional expressions over their lifetimes, old men reveal less evidence of their total emotional experiences in their faces than do old women. PMID:27445944

  17. What Facial Appearance Reveals Over Time: When Perceived Expressions in Neutral Faces Reveal Stable Emotion Dispositions

    PubMed Central

    Adams, Reginald B.; Garrido, Carlos O.; Albohn, Daniel N.; Hess, Ursula; Kleck, Robert E.

    2016-01-01

    It might seem a reasonable assumption that when we are not actively using our faces to express ourselves (i.e., when we display nonexpressive, or neutral faces), those around us will not be able to read our emotions. Herein, using a variety of expression-related ratings, we examined whether age-related changes in the face can accurately reveal one’s innermost affective dispositions. In each study, we found that expressive ratings of neutral facial displays predicted self-reported positive/negative dispositional affect, but only for elderly women, and only for positive affect. These findings meaningfully replicate and extend earlier work examining age-related emotion cues in the face of elderly women (Malatesta et al., 1987a). We discuss these findings in light of evidence that women are expected to, and do, smile more than men, and that the quality of their smiles predicts their life satisfaction. Although ratings of old male faces did not significantly predict self-reported affective dispositions, the trend was similar to that found for old female faces. A plausible explanation for this gender difference is that in the process of attenuating emotional expressions over their lifetimes, old men reveal less evidence of their total emotional experiences in their faces than do old women. PMID:27445944

  18. Enforced expression of the c-myc oncogene inhibits cell differentiation by precluding entry into a distinct predifferentiation state in G0/G1.

    PubMed Central

    Freytag, S O

    1988-01-01

    A broad base of data has implicated a role for the c-myc proto-oncogene in the control of the cell cycle and cell differentiation. To further define the role of myc in these processes, I examined the effect of enforced myc expression on several events that are thought to be important steps leading to the terminally differentiated state: (i) the ability to arrest growth in G0/G1, (ii) the ability to replicate the genome upon initiation of the differentiation program, and (iii) the ability to lose responsiveness to mitogens and withdraw from the cell cycle. 3T3-L1 preadipocyte cell lines expressing various levels of myc mRNA were established by transfection with a recombinant myc gene under the transcriptional control of the Rous sarcoma virus (RSV) promoter. Cells that expressed high constitutive levels of pRSVmyc mRNA arrested in G0/G1 at densities similar to those of normal cells at confluence. Upon initiation of the differentiation program, such cells traversed the cell cycle with kinetics similar to those of normal cells and subsequently arrested in G0/G1. Thus, enforced expression of myc had no effect on the ability of cells to arrest growth in G0/G1 or to replicate the genome upon initiation of the differentiation program. Cells were then tested for their ability to reenter the cell cycle upon exposure to high concentrations of serum and for their capacity to differentiate. In contrast to normal cells, cells expressing high constitutive levels of myc RNA reentered the cell cycle when challenged with 30% serum and failed to terminally differentiate. The block to differentiation could be reversed by high expression of myc antisense RNA, showing that the induced block was specifically due to enforced expression of pRSVmyc. These findings indicate that 3T3-L1 preadipocytes enter a specific state in G0/G1 after treatment with differentiation inducers, into which cells expressing high constitutive levels of myc RNA are precluded from entering. I propose that myc

  19. High Expression of the Newly Found Long Noncoding RNA Z38 Promotes Cell Proliferation and Oncogenic Activity in Breast Cancer

    PubMed Central

    Deng, Rilin; Liu, Bin; Wang, Yan; Yan, Feng; Hu, Shifan; Wang, Hongcan; Wang, Tingting; Li, Bin; Deng, Xiyun; Xiang, Shuanglin; Yang, Yinke; Zhang, Jian

    2016-01-01

    The aberrant expression of long noncoding RNAs (lncRNAs) has great impacts on cancer origination and progression. In the current study, a newly found lncRNA Z38, which was identified through combining experiments of suppression subtractive hybridization (SSH) and reverse dot-blotting, was found to have high expression in breast cancer. More importantly, inhibiting Z38 expression by gene silencing greatly suppressed breast cancer cell proliferation and tumorigenesis, and treatment with Z38 siRNAs significantly induced cell apoptosis and inhibited tumor growth. In conclusion, the newly found lncRNA Z38, which plays important roles in breast cancer, may act as a candidate biomarker and therapeutic target in carcinomas. PMID:27053956

  20. High Expression of the Newly Found Long Noncoding RNA Z38 Promotes Cell Proliferation and Oncogenic Activity in Breast Cancer.

    PubMed

    Deng, Rilin; Liu, Bin; Wang, Yan; Yan, Feng; Hu, Shifan; Wang, Hongcan; Wang, Tingting; Li, Bin; Deng, Xiyun; Xiang, Shuanglin; Yang, Yinke; Zhang, Jian

    2016-01-01

    The aberrant expression of long noncoding RNAs (lncRNAs) has great impacts on cancer origination and progression. In the current study, a newly found lncRNA Z38, which was identified through combining experiments of suppression subtractive hybridization (SSH) and reverse dot-blotting, was found to have high expression in breast cancer. More importantly, inhibiting Z38 expression by gene silencing greatly suppressed breast cancer cell proliferation and tumorigenesis, and treatment with Z38 siRNAs significantly induced cell apoptosis and inhibited tumor growth. In conclusion, the newly found lncRNA Z38, which plays important roles in breast cancer, may act as a candidate biomarker and therapeutic target in carcinomas. PMID:27053956

  1. Exposure to airborne PM2.5 suppresses microRNA expression and deregulates target oncogenes that cause neoplastic transformation in NIH3T3 cells

    PubMed Central

    Cheng, Xinxin; Shao, Mingming; Wu, Chen; Wang, Suhan; Li, Hongmin; Wei, Lixuan; Gao, Yanning; Tan, Wen; Cheng, Shujun; Wu, Tangchun; Yu, Dianke; Lin, Dongxin

    2015-01-01

    Long-term exposure to airborne PM2.5 is associated with increased lung cancer risk but the underlying mechanism remains unclear. We characterized global microRNA and mRNA expression in human bronchial epithelial cells exposed to PM2.5 organic extract and integrally analyzed microRNA-mRNA interactions. Foci formation and xenograft tumorigenesis in mice with NIH3T3 cells expressing genes targeted by microRNAs were performed to explore the oncogenic potential of these genes. We also detected plasma levels of candidate microRNAs in subjects exposed to different levels of air PM2.5 and examined the aberrant expression of genes targeted by these microRNAs in human lung cancer. Under our experimental conditions, treatment of cells with PM2.5 extract resulted in downregulation of 138 microRNAs and aberrant expression of 13 mRNAs (11 upregulation and 2 downregulation). In silico and biochemical analyses suggested SLC30A1, SERPINB2 and AKR1C1, among the upregulated genes, as target for miR-182 and miR-185, respectively. Ectopic expression of each of these genes significantly enhanced foci formation in NIH3T3 cells. Following subcutaneous injection of these cells into nude mice, fibrosarcoma were formed from SLC30A1- or SERPINB2-expressing cells. Reduced plasma levels of miR-182 were detected in subjects exposed to high level of PM2.5 than in those exposed to low level of PM2.5 (P = 0.043). Similar results were seen for miR-185 although the difference was not statistically significant (P = 0.328). Increased expressions of SLC30A1, SERPINB2 and AKR1C1 were detected in human lung cancer. These results suggest that modulation of miR-182 and miR-185 and their target genes may contribute to lung carcinogenesis attributable to PM2.5 exposure. PMID:26338969

  2. SIRT1 inhibits proliferation of pancreatic cancer cells expressing pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, by suppression of {beta}-catenin

    SciTech Connect

    Cho, Il-Rae; Koh, Sang Seok; Malilas, Waraporn; Srisuttee, Ratakorn; Moon, Jeong; Choi, Young-Whan; Horio, Yoshiyuki; Oh, Sangtaek; Chung, Young-Hwa

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer SIRT1 inhibits protein levels of {beta}-catenin and its transcriptional activity. Black-Right-Pointing-Pointer Nuclear localization of SIRT1 is not required for the decrease of {beta}-catenin expression. Black-Right-Pointing-Pointer SIRT1-mediated degradation of {beta}-catenin is not required for GSK-3{beta} and Siah-1 but for proteosome. Black-Right-Pointing-Pointer SIRT1 activation inhibits proliferation of pancreatic cancer cells expressing PAUF. -- Abstract: Because we found in a recent study that pancreatic adenocarcinoma up-regulated factor (PAUF), a novel oncogene, induces a rapid proliferation of pancreatic cells by up-regulation of {beta}-catenin, we postulated that {beta}-catenin might be a target molecule for pancreatic cancer treatment. We thus speculated whether SIRT1, known to target {beta}-catenin in a colon cancer model, suppresses {beta}-catenin in those pancreatic cancer cells that express PAUF (Panc-PAUF). We further evaluated whether such suppression would lead to inhibition of the proliferation of these cells. The ectopic expression of either SIRT1 or resveratrol (an activator of SIRT1) suppressed levels of {beta}-catenin protein and its transcriptional activity in Panc-PAUF cells. Conversely, suppression of SIRT1 expression by siRNA enhanced {beta}-catenin expression and transcriptional activity. SIRT1 mutant analysis showed that nuclear localization of SIRT1 is not required for reduction of {beta}-catenin. Treatment with MG132, a proteasomal inhibitor, restored {beta}-catenin protein levels, suggesting that SIRT1-mediated degradation of {beta}-catenin requires proteasomal activity. It was reported that inhibition of GSK-3{beta} or Siah-1 stabilizes {beta}-catenin in colon cancer cells, but suppression of GSK-3{beta} or Siah-1 using siRNA in the presence of resveratrol instead diminished {beta}-catenin protein levels in Panc-PAUF cells. This suggests that GSK-3{beta} and Siah-1 are not involved in SIRT1

  3. neu protooncogene fused to an immunoglobulin heavy chain gene requires immunoglobulin light chain for cell surface expression and oncogenic transformation.

    PubMed Central

    Flanagan, J G; Leder, P

    1988-01-01

    The protein encoded by the neu protooncogene (human gene symbol NGL for neuro/glioblastoma-derived) is a member of the surface receptor/tyrosine kinase family. Though its structure suggests that it can transduce a transmembrane signal, neither its extracellular ligand nor its critical intracellular substrates are known. To explore the functional properties of the protein encoded by neu, we created a fusion gene that joins the cytoplasmic domain of neu to the extracellular portion of an immunoglobulin heavy chain. The localization of the fusion polypeptide can then be controlled by coexpression with immunoglobulin light chain. In the absence of light chain, the heavy chain-neu polypeptide is expressed intracellularly and has no transforming activity. By contrast, in the presence of light chain the fusion polypeptide is expressed at the cell surface and produces tumorigenic foci. Thus, transformation apparently requires expression at the cell surface, where the neu intracellular domain can interact with components that are localized to the plasma membrane. The fusion protein is active in cellular transformation when the transmembrane domain is derived either from neu or from immunoglobulin, indicating that the neu transmembrane domain is not specifically required for transformation, although neu activation in tumors is known to result from a point mutation in this region. The extracellular immunoglobulin heavy and light chain domains of the fusion protein form a functional binding site that allows antigen to modulate its activity, reversing the transforming effect. Images PMID:2903500

  4. TP53: an oncogene in disguise

    PubMed Central

    Soussi, T; Wiman, K G

    2015-01-01

    The standard classification used to define the various cancer genes confines tumor protein p53 (TP53) to the role of a tumor suppressor gene. However, it is now an indisputable fact that many p53 mutants act as oncogenic proteins. This statement is based on multiple arguments including the mutation signature of the TP53 gene in human cancer, the various gains-of-function (GOFs) of the different p53 mutants and the heterogeneous phenotypes developed by knock-in mouse strains modeling several human TP53 mutations. In this review, we will shatter the classical and traditional image of tumor protein p53 (TP53) as a tumor suppressor gene by emphasizing its multiple oncogenic properties that make it a potential therapeutic target that should not be underestimated. Analysis of the data generated by the various cancer genome projects highlights the high frequency of TP53 mutations and reveals that several p53 hotspot mutants are the most common oncoprotein variants expressed in several types of tumors. The use of Muller's classical definition of mutations based on quantitative and qualitative consequences on the protein product, such as ‘amorph', ‘hypomorph', ‘hypermorph' ‘neomorph' or ‘antimorph', allows a more meaningful assessment of the consequences of cancer gene modifications, their potential clinical significance, and clearly demonstrates that the TP53 gene is an atypical cancer gene. PMID:26024390

  5. Activating the Expression of Human K-rasG12D Stimulates Oncogenic Transformation in Transgenic Goat Fetal Fibroblast Cells

    PubMed Central

    Gong, Jianhua; Wang, Zhongde; Polejaeva, Irina; Salgia, Ravi; Kao, Chien-Min; Chen, Chin-Tu; Chen, Guangchun; Chen, Liaohai

    2014-01-01

    Humane use of preclinical large animal cancer models plays a critical role in understanding cancer biology and developing therapeutic treatments. Among the large animal candidates, goats have great potentials as sustainable sources for large animal cancer model development. Goats are easier to handle and cheaper to raise. The genome of the goats has been sequenced recently. It has been known that goats develop skin, adrenal cortex, breast and other types of cancers. Technically, goats are subject to somatic cell nuclear transfer more efficiently and exhibit better viability through the cloning process. Towards the development of a goat cancer model, we created a transgenic goat fetal fibroblast (GFF) cell as the donor cell for SCNT. Human mutated K-ras (hK-rasG12D) was chosen as the transgene, as it is present in 20% of cancers. Both hK-rasG12D and a herpes simplex viral thymidine kinase (HSV1-tk) reporter genes, flanked by a pair of LoxP sites, were knocked in the GFF endogenous K-ras locus through homologous recombination. Following Cre-mediated activation (with a 95% activation efficiency), hK-rasG12D and HSV1-tk were expressed in the transgenic GFF cells, evidently through the presence of corresponding mRNAs, and confirmed by HSV1-tk protein function assay. The hK-rasG12D expressing GFF cells exhibited enhanced proliferation rates and an anchorage-independent growth behavior. They were able to initiate tumor growth in athymic nude mice. In conclusion, after activating hK-rasG12D gene expression, hK-rasG12D transgenic GFF cells were transformed into tumorgenesis cells. Transgenic goats via SCNT using the above-motioned cells as the donor cells have been established. PMID:24594684

  6. The Dioxin Receptor Regulates the Constitutive Expression of the Vav3 Proto-Oncogene and Modulates Cell Shape and Adhesion

    PubMed Central

    Carvajal-Gonzalez, Jose M.; Mulero-Navarro, Sonia; Roman, Angel Carlos; Sauzeau, Vincent; Merino, Jaime M.; Bustelo, Xose R.

    2009-01-01

    The dioxin receptor (AhR) modulates cell plasticity and migration, although the signaling involved remains unknown. Here, we report a mechanism that integrates AhR into these cytoskeleton-related functions. Immortalized and mouse embryonic fibroblasts lacking AhR (AhR−/−) had increased cell area due to spread cytoplasms that reverted to wild-type morphology upon AhR re-expression. The AhR-null phenotype included increased F-actin stress fibers, depolarized focal adhesions, and enhanced spreading and adhesion. The cytoskeleton alterations of AhR−/− cells were due to down-regulation of constitutive Vav3 expression, a guanosine diphosphate/guanosine triphosphate exchange factor for Rho/Rac GTPases and a novel transcriptional target of AhR. AhR was recruited to the vav3 promoter and maintained constitutive mRNA expression in a ligand-independent manner. Consistently, AhR−/− fibroblasts had reduced Rac1 activity and increased activation of the RhoA/Rho kinase (Rock) pathway. Pharmacological inhibition of Rac1 shifted AhR+/+ fibroblasts to the null phenotype, whereas Rock inhibition changed AhR-null cells to the AhR+/+ morphology. Knockdown of vav3 transcripts by small interfering RNA induced cytoskeleton defects and changes in adhesion and spreading mimicking those of AhR-null cells. Moreover, vav3−/− MEFs, as AhR−/− mouse embryonic fibroblasts, had increased cell area and enhanced stress fibers. By modulating Vav3-dependent signaling, AhR could regulate cell shape, adhesion, and migration under physiological conditions and, perhaps, in certain pathological states. PMID:19158396

  7. Oncogenic NanogP8 expression regulates cell proliferation and migration through the Akt/mTOR signaling pathway in human gastric cancer – SGC-7901cell line

    PubMed Central

    Jiang, Zheng; Liu, Yao; Wang, Chuan

    2016-01-01

    Background Although elevated expression of NanogP8 has been detected in many human tumor tissues, its role in gastric tumorigenesis remains unclear. Therefore, this study aimed to investigate the function and regulatory mechanism of NanogP8 in gastric cancer. Methods In this study, NanogP8 cDNA was amplified by real time polymerase chain reaction from the human gastric cancer cell line SGC-7901. The shRNA for RNA interference was established. The NanogP8, pAkt, Akt, pERK, ERK, p-mTOR, and mTOR proteins were detected by using the Western blot assay. Cell viability was evaluated by using the CCK-8 assay. Cell migration and invasion were also examined by using the transwell assay. Results The results indicated that the NanogP8 overexpression promoted proliferation and migration of SGC-7901 cell line, whereas its ablation exerted opposite effects. Interestingly, NanogP8 activated Akt, a key mediator of survival signals, and without affecting total Akt protein level. The NanogP8-increased gastric cell proliferation was downregulated by Akt inhibition. Our results further showed that increasing NanogP8 expression in human gastric cancer cells promoted cell proliferation by activating the AKT/mTOR pathway and further maintained gastric cell survival. Conclusion Our findings extend the knowledge regarding the oncogenic functions and proved that the NanogP8 regulates cell proliferation and migration by Akt/mTOR signaling pathway in human gastric cancer SGC-7901cell line. PMID:27563247

  8. Induction of cell death by stimulation of protein kinase C in human epithelial cells expressing a mutant ras oncogene: a potential therapeutic target.

    PubMed Central

    Hall-Jackson, C. A.; Jones, T.; Eccles, N. G.; Dawson, T. P.; Bond, J. A.; Gescher, A.; Wynford-Thomas, D.

    1998-01-01

    Ras oncogene activation is a key genetic event in several types of human cancer, making its signal pathways an ideal target for novel therapies. We previously showed that expression of mutant ras sensitizes human thyroid epithelial cells to induction of cell death by treatment with phorbol 12-myristate 13-acetate (PMA) and other phorbol esters. We have now investigated further the nature and mechanism of this cell death using both primary and cell line models. The cytotoxic effect of PMA could be blocked by bisindolylmaleimide (GF 109203X), a well-characterized inhibitor of c and n protein kinase C (PKC) isoforms, and by prior down-regulation of PKC, indicating that it is mediated by acute stimulation, rather than down-regulation. Western analysis identified two candidate isoforms--alpha and epsilon--both of which showed PMA-induced subcellular translocation, either or both of which may be necessary for PMA-induced cell death. Immunofluorescence showed that PMA induced a rapid nuclear translocation of p42 MAP kinase of similar magnitude in the presence or absence of mutant ras expression. Cell death exhibited the microscopic features (chromatin condensation, TdT labelling) and DNA fragmentation typical of apoptosis but after a surprising lag (4 days). Taken together with recent models of ras-modulated apoptosis, our data suggest that activation of the MAPK pathway by PMA tips the balance of pro- and anti-apoptotic signals generated by ras in favour of apoptosis. The high frequency of ras mutations in some cancers, such as cancer of the pancreas, which are refractory to conventional chemotherapy, together with the potential for stimulating PKC by cell-permeant pharmacological agents, makes this an attractive therapeutic approach. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 7 Figure 6 Figure 8 PMID:9744505

  9. Phenotypic Expression in Wheat Revealed Using FT-IR Microspectroscopy

    SciTech Connect

    Brewer, L.; Wetzel, D

    2009-01-01

    Wheat selected for cultivation through the centuries has a glume that is 'soft' instead of 'tough' as naturally occurring. In production, this is desirable because it enables mechanical threshing with efficient separation of kernel from the head of each stalk without damaging the kernel. FT-IR microspectroscopy provides chemically based, objective assessment of genetic expression by measuring the extent of genetic expression. In the Microbeam Molecular Spectroscopy Laboratory, Manhattan, KS, an imaging FT-IR microspectrometer with a detector array focused on the image plane was used to obtain spectral data from dissected glume specimens of nine tough and eleven soft wheat cultivars in a rectangular mapping pattern. With cellulose as the substrate, the extent of lignification is measurable from the ratio of the lignin (1508 cm{sup -1}) baseline adjusted band area to the representative cellulosic (1370 cm{sup -1}) band area. A distinction between soft and tough glumes is obtained in numerical terms. Using a band ratio minimizes variation due to thickness differences. While analyzing mapped sections of glume, care is taken to avoid tabulation of spectral data from vascular bundles. Inclusion of these data would to avoid tabulation of spectral data from vascular bundles. Inclusion of these data would bias the analysis toward the composition of highly lignified vascular bundles. Spatially resolved focal plane array FT-IR microspectroscopy reveals the extent of glume lignification that is coincident with the toughness trait. This enables breeders to rank the degree of lignin expression and discriminate between soft and tough breeding results.

  10. 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

  11. Genome-Wide Gene Expression Analysis Identifies the Proto-oncogene Tyrosine-Protein Kinase Src as a Crucial Virulence Determinant of Infectious Laryngotracheitis Virus in Chicken Cells

    PubMed Central

    Li, Hai; Wang, Fengjie; Han, Zongxi; Gao, Qi; Li, Huixin; Shao, Yuhao; Sun, Nana

    2015-01-01

    ABSTRACT Given the side effects of vaccination against infectious laryngotracheitis (ILT), novel strategies for ILT control and therapy are urgently needed. The modulation of host-virus interactions is a promising strategy to combat the virus; however, the interactions between the host and avian ILT herpesvirus (ILTV) are unclear. Using genome-wide transcriptome studies in combination with a bioinformatic analysis, we identified proto-oncogene tyrosine-protein kinase Src (Src) to be an important modulator of ILTV infection. Src controls the virulence of ILTV and is phosphorylated upon ILTV infection. Functional studies revealed that Src prolongs the survival of host cells by increasing the threshold of virus-induced cell death. Therefore, Src is essential for viral replication in vitro and in ovo but is not required for ILTV-induced cell death. Furthermore, our results identify a positive-feedback loop between Src and the tyrosine kinase focal adhesion kinase (FAK), which is necessary for the phosphorylation of either Src or FAK and is required for Src to modulate ILTV infection. To the best of our knowledge, we are the first to identify a key host regulator controlling host-ILTV interactions. We believe that our findings have revealed a new potential therapeutic target for ILT control and therapy. IMPORTANCE Despite the extensive administration of live attenuated vaccines starting from the mid-20th century and the administration of recombinant vaccines in recent years, infectious laryngotracheitis (ILT) outbreaks due to avian ILT herpesvirus (ILTV) occur worldwide annually. Presently, there are no drugs or control strategies that effectively treat ILT. Targeting of host-virus interactions is considered to be a promising strategy for controlling ILTV infections. However, little is known about the mechanisms governing host-ILTV interactions. The results from our study advance our understanding of host-ILTV interactions on a molecular level and provide experimental

  12. The rs391957 variant cis-regulating oncogene GRP78 expression contributes to the risk of hepatocellular carcinoma.

    PubMed

    Zhu, Xiao; Zhang, Jinfang; Fan, Wenguo; Wang, Fang; Yao, Hong; Wang, Zifeng; Hou, Shengping; Tian, Yinghong; Fu, Weiming; Xie, Dan; Zhu, Wei; Long, Jun; Wu, Leijie; Zheng, Xuebao; Kung, Hsiangfu; Zhou, Keyuan; Lin, Marie C M; Luo, Hui; Li, Dongpei

    2013-06-01

    Glucose-regulated protein 78 (GRP78) is one of the most important responders to disease-related stress. We assessed the association of the promoter polymorphisms of GRP78 with risk of hepatocellular carcinoma (HCC) and GRP78 expression in a Chinese population. We examined 1007 patients undergoing diagnostic HCC and 810 unrelated healthy controls. Mechanisms by which the GRP78 promoter polymorphism modulates HCC risk and GRP78 levels were analyzed. The promoter haplotype and diplotype carrying rs391957 (-415bp) allele G and genotype GG was strongly associated with HCC risk. Luciferase reporter assays indicated that the promoter carrying rs391957 allele G (haplotype GCCd) showed increased activity in HepG2 cells and Hela cells. rs391957 was also shown to increase the affinity of the transcriptional activator Ets-2, the resistance to apoptosis, as well as cell instability in stressful microenvironment. Furthermore, compared with allele A, rs391957 allele G was associated with higher levels of GRP78 mRNA and protein in HCC tissues. These findings provided new insights into the pathogenesis of HCC and an unexpected effect of the interaction between rs391957 and Ets-2 on hepatocarcinogenesis, and especially supported the hypothesis that stress-related and evolutionarily conserved genetic variant(s) influencing transcriptional regulation could predict susceptibilities. PMID:23416888

  13. Suppressor of cytokine signaling 1-dependent regulation of the expression and oncogenic functions of p21(CIP1/WAF1) in the liver.

    PubMed

    Yeganeh, M; Gui, Y; Kandhi, R; Bobbala, D; Tobelaim, W-S; Saucier, C; Yoshimura, A; Ferbeyre, G; Ramanathan, S; Ilangumaran, S

    2016-08-11

    tumor-suppressor functions of SOCS1 in the liver could be mediated, at least partly, via regulation of the expression, stability and subcellular distribution of p21 and its paradoxical oncogenic functions, namely, resistance to apoptosis and increased proliferation. PMID:26725321

  14. Computational gene expression profiling under salt stress reveals patterns of co-expression.

    PubMed

    Sanchita; Sharma, Ashok

    2016-03-01

    Plants respond differently to environmental conditions. Among various abiotic stresses, salt stress is a condition where excess salt in soil causes inhibition of plant growth. To understand the response of plants to the stress conditions, identification of the responsible genes is required. Clustering is a data mining technique used to group the genes with similar expression. The genes of a cluster show similar expression and function. We applied clustering algorithms on gene expression data of Solanum tuberosum showing differential expression in Capsicum annuum under salt stress. The clusters, which were common in multiple algorithms were taken further for analysis. Principal component analysis (PCA) further validated the findings of other cluster algorithms by visualizing their clusters in three-dimensional space. Functional annotation results revealed that most of the genes were involved in stress related responses. Our findings suggest that these algorithms may be helpful in the prediction of the function of co-expressed genes. PMID:26981411

  15. Inhibition of MEK5 by BIX02188 induces apoptosis in cells expressing the oncogenic mutant FLT3-ITD

    SciTech Connect

    Razumovskaya, Elena; Sun, Jianmin; Roennstrand, Lars

    2011-08-26

    Highlights: {yields} In this study we have demonstrated that FLT3 activation leads to activation of ERK5. {yields} We have demonstrated that ERK5 is involved in activation of AKT downstream of FLT3. {yields} (BIX02188) blocks activation of ERK5 and induces apoptosis in FLT3 Ba/F3 cells. {yields} (BIX02188) induce apoptosis in the two leukemic cell lines MV4-11 and MOLM-13. -- Abstract: Fms-like tyrosine kinase-3 (FLT3) is a growth factor receptor normally expressed on hematopoietic progenitor cells. Approximately one third of all patients with AML carry an activating mutation in FLT3 that drives proliferation and survival of the leukemic cells. The most common activating mutation is the so-called internal tandem duplication (ITD), which involves an in-frame duplication of a segment of varying length in the region of the FLT3 gene that encodes the juxtamembrane domain. The pathways downstream of FLT3-ITD are partially known but further knowledge regarding the downstream signal transduction molecules is important in order to develop alternative strategies for pharmacological intervention. In this paper we have studied the role of MEK/ERK5 in FLT3-ITD mediated transformation. We have found that both wild-type FLT3 and FLT3-ITD activate MEK5 leading to the activation of ERK5. By use of the selective inhibitor of MEK5, (BIX02188), we have shown that activation of AKT downstream of FLT3 is partially dependent on ERK5. Furthermore, inhibition of MEK5/ERK5 induces apoptosis of both FLT3-ITD transfected Ba/F3 cells as well as the FLT3-ITD carrying leukemic cell lines MV4-11 and MOLM-13. These results suggest that MEK5/ERK5 is important for FLT3-ITD induced hematopoietic transformation and may thus represent an alternative therapeutic target in the treatment of FLT3-ITD positive leukemia.

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

    PubMed Central

    Perera, David; Venkitaraman, Ashok R.

    2016-01-01

    Oncogenic KRAS induces cell proliferation and transformation, but little is known about its effects on cell division. Functional genetic screens have recently revealed that cancer cell lines expressing oncogenic KRAS are sensitive to interference with mitosis, but neither the mechanism nor the uniformity of anti-mitotic drug sensitivity connected with mutant KRAS expression are yet clear. Here, we report that acute expression of oncogenic KRAS in HeLa cells induces mitotic delay and defects in chromosome segregation through mitogen-activated protein kinase (MAPK) pathway activation and de-regulated expression of several mitosis-related genes. These anomalies are accompanied by increased sensitivity to anti-mitotic agents, a phenotype dependent on the transcription factor MYC and its downstream target anti-apoptotic protein BCL-XL. Unexpectedly, we find no correlation between KRAS mutational status or MYC expression levels and anti-mitotic drug sensitivity when surveying a large database of anti-cancer drug responses. However, we report that the co-existence of KRAS mutations and high MYC expression predicts anti-mitotic drug sensitivity. Our findings reveal a novel function of oncogenic KRAS in regulating accurate mitotic progression and suggest new avenues to therapeutically target KRAS-mutant tumours and stratify patients in ongoing clinical trials of anti-mitotic drugs. PMID:27412232

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

    PubMed

    Perera, David; Venkitaraman, Ashok R

    2016-01-01

    Oncogenic KRAS induces cell proliferation and transformation, but little is known about its effects on cell division. Functional genetic screens have recently revealed that cancer cell lines expressing oncogenic KRAS are sensitive to interference with mitosis, but neither the mechanism nor the uniformity of anti-mitotic drug sensitivity connected with mutant KRAS expression are yet clear. Here, we report that acute expression of oncogenic KRAS in HeLa cells induces mitotic delay and defects in chromosome segregation through mitogen-activated protein kinase (MAPK) pathway activation and de-regulated expression of several mitosis-related genes. These anomalies are accompanied by increased sensitivity to anti-mitotic agents, a phenotype dependent on the transcription factor MYC and its downstream target anti-apoptotic protein BCL-XL. Unexpectedly, we find no correlation between KRAS mutational status or MYC expression levels and anti-mitotic drug sensitivity when surveying a large database of anti-cancer drug responses. However, we report that the co-existence of KRAS mutations and high MYC expression predicts anti-mitotic drug sensitivity. Our findings reveal a novel function of oncogenic KRAS in regulating accurate mitotic progression and suggest new avenues to therapeutically target KRAS-mutant tumours and stratify patients in ongoing clinical trials of anti-mitotic drugs. PMID:27412232

  18. The Effect of Lactobacillus crispatus and Lactobacillus rhamnosusCulture Supernatants on Expression of Autophagy Genes and HPV E6 and E7 Oncogenes in The HeLa Cell Line

    PubMed Central

    Motevaseli, Elahe; Azam, Rosa; Akrami, Seyed Mohammad; Mazlomy, Mohammadali; Saffari, Mojtaba; Modarressi, Mohammad Hossein; Daneshvar, Maryam; Ghafouri-Fard, Soudeh

    2016-01-01

    Objective The aim of this study was to clarify the mechanism by which lactobacilli exert their cytotoxic effects on cervical cancer cells. In addition, we aimed to evalu- ate the effect of lactobacilli on the expression of human papilloma virus (HPV) onco- genes. Materials and Methods In this experimental study, using quantitative real-time polymer- ase chain reaction (PCR), we analyzed the expression of CASP3 and three autophagy genes [ATG14, BECN1 and alpha 2 catalytic subunit of AMPK (PRKAA2)] along with HPV18 E6 and E7 genes in HeLa cells before and after treatment with Lactobacillus crispatus and Lactobacillus rhamnosus culture supernatants. Results The expression of CASP3 and autophagy genes in HeLa cells was de- creased after treatment with lactobacilli culture supernatants. However, this de- crease was not significant for PRKAA2 when compared with controls. In addition, expression of HPV E6 was significantly decreased after treatment with lactobacilli culture supernatants. Conclusion Lactobacilli culture supernatants can decrease expression of ATG14 and BECN1 as well as the HPV E6 oncogene. It has been demonstrated that the main changes occurring during cervical carcinogenesis in cell machinery can be reversed by suppression of HPV oncogenes. Therefore, downregulation of HPV E6 by lacto- bacilli may have therapeutic potential for cervical cancer. As the role of autophagy in cancer is complicated, further work is required to clarify the link between downregula- tion of autophagy genes and antiproliferative effects exerted by lactobacilli. PMID:26862519

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

    PubMed

    Tsai, Chi-Neu; Tsai, Chia-Lung; Tse, Ka-Po; Chang, Hwan-You; Chang, Yu-Sun

    2002-07-23

    The latent membrane protein (LMP1) of Epstein-Barr virus (EBV) is expressed in EBV-associated nasopharyngeal carcinoma, which is notoriously metastatic. Although it is established that LMP1 represses E-cadherin expression and enhances the invasive ability of carcinoma cells, the mechanism underlying this repression remains to be elucidated. In this study, we demonstrate that LMP1 induces the expression and activity of the DNA methyltransferases 1, 3a, and 3b, using real-time reverse transcription-PCR and enzyme activity assay. This results in hypermethylation of the E-cadherin promoter and down-regulation of E-cadherin gene expression, as revealed by methylation-specific PCR, real-time reverse transcription-PCR and Western blotting data. The DNA methyltransferase inhibitor, 5'-Aza-2'dC, restores E-cadherin promoter activity and protein expression in LMP1-expressing cells, which in turn blocks cell migration ability, as demonstrated by the Transwell cell migration assay. Our findings suggest that LMP1 down-regulates E-cadherin gene expression and induces cell migration activity by using cellular DNA methylation machinery. PMID:12110730

  20. Expression analysis of five zebrafish RXFP3 homologues reveals evolutionary conservation of gene expression pattern.

    PubMed

    Donizetti, Aldo; Fiengo, Marcella; Iazzetti, Giovanni; del Gaudio, Rosanna; Di Giaimo, Rossella; Pariante, Paolo; Minucci, Sergio; Aniello, Francesco

    2015-01-01

    Relaxin peptides exert different functions in reproduction and neuroendocrine processes via interaction with two evolutionarily unrelated groups of receptors: RXFP1 and RXFP2 on one hand, RXFP3 and RXFP4 on the other hand. Evolution of receptor genes after splitting of tetrapods and teleost lineage led to a different retention rate between mammals and fish, with the latter having more gene copies compared to the former. In order to improve our knowledge on the evolution of the relaxin ligands/receptors system and have insights on their function in early stages of life, in the present paper we analyzed the expression pattern of five zebrafish RXFP3 homologue genes during embryonic development. In our analysis, we show that only two of the five genes are expressed during embryogenesis and that their transcripts are present in all the developmental stages. Spatial localization analysis of these transcripts revealed that the gene expression is restricted in specific territories starting from early pharyngula stage. Both genes are expressed in the brain but in different cell clusters and in extra-neural territories, one gene in the interrenal gland and the other in the pancreas. These two genes share expression territories with the homologue mammalian counterpart, highlighting a general conservation of gene expression regulatory processes and their putative function during evolution that are established early in vertebrate embryogenesis. PMID:25384467

  1. 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

  2. Evidence that synthetic lethality underlies the mutual exclusivity of oncogenic KRAS and EGFR mutations in lung adenocarcinoma

    PubMed Central

    Unni, Arun M; Lockwood, William W; Zejnullahu, Kreshnik; Lee-Lin, Shih-Queen; Varmus, Harold

    2015-01-01

    Human lung adenocarcinomas (LUAD) contain mutations in EGFR in ∼15% of cases and in KRAS in ∼30%, yet no individual adenocarcinoma appears to carry activating mutations in both genes, a finding we have confirmed by re-analysis of data from over 600 LUAD. Here we provide evidence that co-occurrence of mutations in these two genes is deleterious. In transgenic mice programmed to express both mutant oncogenes in the lung epithelium, the resulting tumors express only one oncogene. We also show that forced expression of a second oncogene in human cancer cell lines with an endogenous mutated oncogene is deleterious. The most prominent features accompanying loss of cell viability were vacuolization, other changes in cell morphology, and increased macropinocytosis. Activation of ERK, p38 and JNK in the dying cells suggests that an overly active MAPK signaling pathway may mediate the phenotype. Together, our findings indicate that mutual exclusivity of oncogenic mutations may reveal unexpected vulnerabilities and therapeutic possibilities. DOI: http://dx.doi.org/10.7554/eLife.06907.001 PMID:26047463

  3. Inhibition of Prostaglandin Reductase 2, a Putative Oncogene Overexpressed in Human Pancreatic Adenocarcinoma, Induces Oxidative Stress-Mediated Cell Death Involving xCT and CTH Gene Expressions through 15-Keto-PGE2.

    PubMed

    Chang, Emily Yun-Chia; Chang, Yi-Cheng; Shun, Chia-Tung; Tien, Yu-Wen; Tsai, Shu-Huei; Hee, Siow-Wey; Chen, Ing-Jung; Chuang, Lee-Ming

    2016-01-01

    Prostaglandin reductase 2 (PTGR2) is the enzyme that catalyzes 15-keto-PGE2, an endogenous PPARγ ligand, into 13,14-dihydro-15-keto-PGE2. Previously, we have reported a novel oncogenic role of PTGR2 in gastric cancer, where PTGR2 was discovered to modulate ROS-mediated cell death and tumor transformation. In the present study, we demonstrated the oncogenic potency of PTGR2 in pancreatic cancer. First, we observed that the majority of the human pancreatic ductal adenocarcinoma tissues was stained positive for PTGR2 expression but not in the adjacent normal parts. In vitro analyses showed that silencing of PTGR2 expression enhanced ROS production, suppressed pancreatic cell proliferation, and promoted cell death through increasing 15-keto-PGE2. Mechanistically, silencing of PTGR2 or addition of 15-keto-PGE2 suppressed the expressions of solute carrier family 7 member 11 (xCT) and cystathionine gamma-lyase (CTH), two important providers of intracellular cysteine for the generation of glutathione (GSH), which is widely accepted as the first-line antioxidative defense. The oxidative stress-mediated cell death after silencing of PTGR2 or addition of 15-keto-PGE2 was further abolished after restoring intracellular GSH concentrations and cysteine supply by N-acetyl-L-cysteine and 2-Mercaptomethanol. Our data highlight the therapeutic potential of targeting PTGR2/15-keto-PGE2 for pancreatic cancer. PMID:26820738

  4. Inhibition of Prostaglandin Reductase 2, a Putative Oncogene Overexpressed in Human Pancreatic Adenocarcinoma, Induces Oxidative Stress-Mediated Cell Death Involving xCT and CTH Gene Expressions through 15-Keto-PGE2

    PubMed Central

    Chang, Emily Yun-Chia; Chang, Yi-Cheng; Shun, Chia-Tung; Tien, Yu-Wen; Tsai, Shu-Huei; Hee, Siow-Wey; Chen, Ing-Jung; Chuang, Lee-Ming

    2016-01-01

    Prostaglandin reductase 2 (PTGR2) is the enzyme that catalyzes 15-keto-PGE2, an endogenous PPARγ ligand, into 13,14-dihydro-15-keto-PGE2. Previously, we have reported a novel oncogenic role of PTGR2 in gastric cancer, where PTGR2 was discovered to modulate ROS-mediated cell death and tumor transformation. In the present study, we demonstrated the oncogenic potency of PTGR2 in pancreatic cancer. First, we observed that the majority of the human pancreatic ductal adenocarcinoma tissues was stained positive for PTGR2 expression but not in the adjacent normal parts. In vitro analyses showed that silencing of PTGR2 expression enhanced ROS production, suppressed pancreatic cell proliferation, and promoted cell death through increasing 15-keto-PGE2. Mechanistically, silencing of PTGR2 or addition of 15-keto-PGE2 suppressed the expressions of solute carrier family 7 member 11 (xCT) and cystathionine gamma-lyase (CTH), two important providers of intracellular cysteine for the generation of glutathione (GSH), which is widely accepted as the first-line antioxidative defense. The oxidative stress-mediated cell death after silencing of PTGR2 or addition of 15-keto-PGE2 was further abolished after restoring intracellular GSH concentrations and cysteine supply by N-acetyl-L-cysteine and 2-Mercaptomethanol. Our data highlight the therapeutic potential of targeting PTGR2/15-keto-PGE2 for pancreatic cancer. PMID:26820738

  5. The RET oncogene in papillary thyroid carcinoma.

    PubMed

    Prescott, Jason D; Zeiger, Martha A

    2015-07-01

    Papillary thyroid carcinoma (PTC) is the most common form of thyroid cancer, accounting for greater than 80% of cases. Surgical resection, with or without postoperative radioiodine therapy, remains the standard of care for patients with PTC, and the prognosis is generally excellent with appropriate treatment. Despite this, significant numbers of patients will not respond to maximal surgical and medical therapy and ultimately will die from the disease. This mortality reflects an incomplete understanding of the oncogenic mechanisms that initiate, drive, and promote PTC. Nonetheless, significant insights into the pathologic subcellular events underlying PTC have been discovered over the last 2 decades, and this remains an area of significant research interest. Chromosomal rearrangements resulting in the expression of fusion proteins that involve the rearranged during transfection (RET) proto-oncogene were the first oncogenic events to be identified in PTC. Members of this fusion protein family (the RET/PTC family) appear to play an oncogenic role in approximately 20% of PTCs. Herein, the authors review the current understanding of the clinicopathologic role of RET/PTC fusion proteins in PTC development and progression and the molecular mechanisms by which RET/PTCs exert their oncogenic effects on the thyroid epithelium. PMID:25731779

  6. Targeted expression of the E6 and E7 oncogenes of human papillomavirus type 16 in the epidermis of transgenic mice elicits generalized epidermal hyperplasia involving autocrine factors.

    PubMed Central

    Auewarakul, P; Gissmann, L; Cid-Arregui, A

    1994-01-01

    The E6 and E7 early genes of human papillomavirus type 16 have been shown in vitro to play a central role in the transforming capability of this virus. To explore their effects on differentiating epithelial cells in vivo, we used a bovine cytokeratin 10 (K10) promoter to target the expression of E6 and E7 to the suprabasal layers of the epidermis of transgenic mice. In two different lines of mice efficiently expressing the transgene, animals displayed generalized epidermal hyperplasia, hyperkeratosis and parakeratosis in the skin and the forestomach, both known to be sites of K10 expression. Northern (RNA) blot analysis revealed high levels of E6 and E7 transcripts, and in situ hybridizations localized these transcripts to the suprabasal strata of epidermis. In vivo labeling of proliferating cells showed two distinct effects of E6 and E7 expression in the epidermis: (i) an increase in the number of growing cells in the undifferentiated basal layer and (ii) abnormal proliferation of differentiated cells in the suprabasal strata. The expression of c-myc in the skin of transgenics was higher than that in control animals. The induction of c-myc transcription by topical application of tetradecanoyl phorbol acetate was prevented by simultaneous treatment with transforming growth factor beta 1 in nontransgenic skin but not in transgenic skin. In addition, transforming growth factor alpha was found to be overexpressed in the suprabasal layers of the transgenic epidermis. These findings suggest that autocrine mechanisms are involved in the development and maintenance of epidermal hyperplasia. Animals of both lines developed papillomas in skin sites exposed to mechanical irritation and wounding, suggesting that secondary events are necessary for progression to neoplasia. Collectively, these results provide new insights into the tumor promoter activities of human papillomavirus type 16 in epithelial cells in vivo. Images PMID:7969162

  7. Metaproteomics reveals abundant transposase expression in mutualistic endosymbionts

    SciTech Connect

    Kleiner, Manuel; Young, Jacque C; Shah, Manesh B; Verberkmoes, Nathan C; Dubilier, Nicole

    2013-01-01

    Transposases, enzymes that catalyze the movement of mobile genetic elements, are the most abundant genes in nature. While many bacteria encode an abundance of transposases in their genomes, the current paradigm is that transposase gene expression is tightly regulated and generally low due to its severe mutagenic effects. In the current study, we detected the highest number of transposase proteins ever reported in bacteria, in symbionts of the gutless marine worm Olavius algarvensis using metaproteomics. At least 26 different transposases from 12 different families were detected and genomic and proteomic analyses suggest many of these are active. This high expression of transposases indicates that the mechanisms for their tight regulation have been disabled or destroyed. Based on recent studies on other symbionts and pathogens that showed high transposase transcription, we speculate that abundant transposase expression might be common in symbionts and pathogens.

  8. 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.

  9. [Hypophosphatemic oncogenic osteomalacia].

    PubMed

    Mátyus, J; Szebenyi, B; Rédl, P; Mikita, J; Gáspár, L; Haris, A; Radó, J; Kakuk, G

    2000-12-17

    The first case of oncogen osteomalacia in Hungary is reported, to draw the attention of the medical profession to it and to present the new data about its pathomechanism. Pathological hip fracture caused by hypophosphataemic osteomalacia due to isolated renal phosphate wasting was found in a previously healthy 19 years old sportsman. In spite of daily 1.5 micrograms calcitriol treatment and phosphate supplementation, hypophosphataemia persisted for 13 years and he needed regular indometacin medication for his bone pain. During that time an 1.5 cm gingival tumour was found and radically removed. The serum phosphate level returned to normal in a few hours after the operation (preoperative 0.51, after 2, 4 and 8 hours 0.61, 0.68 and 0.79 mmol/l respectively), and remained normal without calcitriol. The histological examination showed epulis with fibroblast and vascular cell proliferation, which has never been previously reported in connection with oncogenic osteomalacia. The pain resolved after 3 months and the bone density became normal in one year. Oncogenic osteomalacia must be considered in every case presenting with atypical hypophosphataemic osteomalacia. Careful dental examination is needed also in the course of search for the underlying tumour. Every tumour-like growth, even the common epulis, has to be operated radically and serum phosphate monitored in the postoperative period in all such cases. PMID:11196239

  10. Expression patterns reveal niche diversification in a marine microbial assemblage

    PubMed Central

    Gifford, Scott M; Sharma, Shalabh; Booth, Melissa; Moran, Mary Ann

    2013-01-01

    Resolving the ecological niches of coexisting marine microbial taxa is challenging due to the high species richness of microbial communities and the apparent functional redundancy in bacterial genomes and metagenomes. Here, we generated over 11 million Illumina reads of protein-encoding transcripts collected from well-mixed southeastern US coastal waters to characterize gene expression patterns distinguishing the ecological roles of hundreds of microbial taxa sharing the same environment. The taxa with highest in situ growth rates (based on relative abundance of ribosomal protein transcripts) were typically not the greatest contributors to community transcription, suggesting strong top-down ecological control, and their diverse transcriptomes indicated roles as metabolic generalists. The taxa with low in situ growth rates typically had low diversity transcriptomes dominated by specialized metabolisms. By identifying protein-encoding genes with atypically high expression for their level of conservation, unique functional roles of community members emerged related to substrate use (such as complex carbohydrates, fatty acids, methanesulfonate, taurine, tartrate, ectoine), alternative energy-conservation strategies (proteorhodopsin, AAnP, V-type pyrophosphatases, sulfur oxidation, hydrogen oxidation) and mechanisms for negotiating a heterogeneous environment (flagellar motility, gliding motility, adhesion strategies). On average, the heterotrophic bacterioplankton dedicated 7% of their transcriptomes to obtaining energy by non-heterotrophic means. This deep sequencing of a coastal bacterioplankton transcriptome provides the most highly resolved view of bacterioplankton niche dimensions yet available, uncovering a spectrum of unrecognized ecological strategies. PMID:22931830

  11. Genome Wide Expression Profiling of Cancer Cell Lines Cultured in Microgravity Reveals Significant Dysregulation of Cell Cycle and MicroRNA Gene Networks

    PubMed Central

    Vidyasekar, Prasanna; Shyamsunder, Pavithra; Arun, Rajpranap; Santhakumar, Rajalakshmi; Kapadia, Nand Kishore; Kumar, Ravi; Verma, Rama Shanker

    2015-01-01

    Zero gravity causes several changes in metabolic and functional aspects of the human body and experiments in space flight have demonstrated alterations in cancer growth and progression. This study reports the genome wide expression profiling of a colorectal cancer cell line-DLD-1, and a lymphoblast leukemic cell line-MOLT-4, under simulated microgravity in an effort to understand central processes and cellular functions that are dysregulated among both cell lines. Altered cell morphology, reduced cell viability and an aberrant cell cycle profile in comparison to their static controls were observed in both cell lines under microgravity. The process of cell cycle in DLD-1 cells was markedly affected with reduced viability, reduced colony forming ability, an apoptotic population and dysregulation of cell cycle genes, oncogenes, and cancer progression and prognostic markers. DNA microarray analysis revealed 1801 (upregulated) and 2542 (downregulated) genes (>2 fold) in DLD-1 cultures under microgravity while MOLT-4 cultures differentially expressed 349 (upregulated) and 444 (downregulated) genes (>2 fold) under microgravity. The loss in cell proliferative capacity was corroborated with the downregulation of the cell cycle process as demonstrated by functional clustering of DNA microarray data using gene ontology terms. The genome wide expression profile also showed significant dysregulation of post transcriptional gene silencing machinery and multiple microRNA host genes that are potential tumor suppressors and proto-oncogenes including MIR22HG, MIR17HG and MIR21HG. The MIR22HG, a tumor-suppressor gene was one of the highest upregulated genes in the microarray data showing a 4.4 log fold upregulation under microgravity. Real time PCR validated the dysregulation in the host gene by demonstrating a 4.18 log fold upregulation of the miR-22 microRNA. Microarray data also showed dysregulation of direct targets of miR-22, SP1, CDK6 and CCNA2. PMID:26295583

  12. Genome Wide Expression Profiling of Cancer Cell Lines Cultured in Microgravity Reveals Significant Dysregulation of Cell Cycle and MicroRNA Gene Networks.

    PubMed

    Vidyasekar, Prasanna; Shyamsunder, Pavithra; Arun, Rajpranap; Santhakumar, Rajalakshmi; Kapadia, Nand Kishore; Kumar, Ravi; Verma, Rama Shanker

    2015-01-01

    Zero gravity causes several changes in metabolic and functional aspects of the human body and experiments in space flight have demonstrated alterations in cancer growth and progression. This study reports the genome wide expression profiling of a colorectal cancer cell line-DLD-1, and a lymphoblast leukemic cell line-MOLT-4, under simulated microgravity in an effort to understand central processes and cellular functions that are dysregulated among both cell lines. Altered cell morphology, reduced cell viability and an aberrant cell cycle profile in comparison to their static controls were observed in both cell lines under microgravity. The process of cell cycle in DLD-1 cells was markedly affected with reduced viability, reduced colony forming ability, an apoptotic population and dysregulation of cell cycle genes, oncogenes, and cancer progression and prognostic markers. DNA microarray analysis revealed 1801 (upregulated) and 2542 (downregulated) genes (>2 fold) in DLD-1 cultures under microgravity while MOLT-4 cultures differentially expressed 349 (upregulated) and 444 (downregulated) genes (>2 fold) under microgravity. The loss in cell proliferative capacity was corroborated with the downregulation of the cell cycle process as demonstrated by functional clustering of DNA microarray data using gene ontology terms. The genome wide expression profile also showed significant dysregulation of post transcriptional gene silencing machinery and multiple microRNA host genes that are potential tumor suppressors and proto-oncogenes including MIR22HG, MIR17HG and MIR21HG. The MIR22HG, a tumor-suppressor gene was one of the highest upregulated genes in the microarray data showing a 4.4 log fold upregulation under microgravity. Real time PCR validated the dysregulation in the host gene by demonstrating a 4.18 log fold upregulation of the miR-22 microRNA. Microarray data also showed dysregulation of direct targets of miR-22, SP1, CDK6 and CCNA2. PMID:26295583

  13. 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

  14. 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

  15. Crystallin gene expression and lentoid body formation in quail embryo neuroretina cultures transformed by the oncogenic retrovirus Mill Hill 2 or Rous sarcoma virus.

    PubMed Central

    Simonneau, L; Crisanti, P; Lorinet, A M; Alliot, F; Courtois, Y; Calothy, G; Pessac, B

    1986-01-01

    The lens-specific proteins alpha and delta crystallins and lentoid bodies, structures that follow a differentiation pathway similar to that of the lens, regularly appear after 4 to 5 weeks in quail embryo neuroretina monolayer cultures. We have investigated the effects of the avian oncogenic retroviruses Mill Hill 2 and Rous sarcoma virus on this process. Quail embryo neuroretina cells transformed by Mill Hill 2 virus were established into permanent cultures that synthesized alpha and delta crystallins and contained stem cells for the production of lentoid bodies. In contrast, transformation with the Rous sarcoma virus mutant tsNY-68 blocked the appearance of mRNA crystallins, but cytoplasmic alpha and delta crystallin mRNA and alpha crystallin appeared 44 h after a shift to the nonpermissive temperature. However, delta crystallins and lentoid bodies were only present after 7 days. The crystallins of transformed quail neuroretina cultures were immunologically indistinguishable from those of quail lenses and of normal quail embryo neuroretina cultures. Images PMID:3025609

  16. Nucleotide sequence and expression in vitro of cDNA derived from mRNA of int-1, a provirally activated mouse mammary oncogene.

    PubMed Central

    Fung, Y K; Shackleford, G M; Brown, A M; Sanders, G S; Varmus, H E

    1985-01-01

    The mouse int-1 gene is a putative mammary oncogene discovered as a target for transcriptionally activating proviral insertion mutations in mammary carcinomas induced by the mouse mammary tumor virus in C3H mice. We have isolated molecular clones of full- or nearly full-length cDNA transcribed from int-1 RNA (2.6 kilobases) in a virus-induced mammary tumor. Comparison of the nucleotide sequence of the cDNA clones with that of the int-1 gene (A. van Ooyen and R. Nusse, Cell 39:233-240, 1984) shows the following. The coding region of the int-1 gene is composed of four exons. The splice donor and acceptor sites conform to consensus; however, at least two closely spaced polyadenylation sites are used, and the transcriptional initiation site remains ambiguous. The major open reading frame is preceded by an open frame 10 codons in length. The mRNA encodes a 41-kilodalton protein with several striking features--a strongly hydrophobic amino terminus, a cysteine-rich carboxy terminus, and four potential glycosylation sites. There are no differences in nucleotide sequence between the known exons of the normal and a provirally activated allele. The length of the deduced open reading frame was further confirmed by in vitro translation of RNA transcribed from the cDNA clones with SP6 RNA polymerase. Images PMID:3018519

  17. 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.

  18. 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

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

    PubMed

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

    2016-06-14

    Mutations in transcription factor (TF) 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 TF 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 supported these predictions. Application of CRAFTT to ERG, a pro-invasive, frequently overexpressed oncogenic TF, predicted that dexamethasone would inhibit ERG activity. 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 for identifying drugs that specifically modulate TF activity. PMID:27264179

  20. Reconstructing dynamic mental models of facial expressions in prosopagnosia reveals distinct representations for identity and expression.

    PubMed

    Richoz, Anne-Raphaëlle; Jack, Rachael E; Garrod, Oliver G B; Schyns, Philippe G; Caldara, Roberto

    2015-04-01

    The human face transmits a wealth of signals that readily provide crucial information for social interactions, such as facial identity and emotional expression. Yet, a fundamental question remains unresolved: does the face information for identity and emotional expression categorization tap into common or distinct representational systems? To address this question we tested PS, a pure case of acquired prosopagnosia with bilateral occipitotemporal lesions anatomically sparing the regions that are assumed to contribute to facial expression (de)coding (i.e., the amygdala, the insula and the posterior superior temporal sulcus--pSTS). We previously demonstrated that PS does not use information from the eye region to identify faces, but relies on the suboptimal mouth region. PS's abnormal information use for identity, coupled with her neural dissociation, provides a unique opportunity to probe the existence of a dichotomy in the face representational system. To reconstruct the mental models of the six basic facial expressions of emotion in PS and age-matched healthy observers, we used a novel reverse correlation technique tracking information use on dynamic faces. PS was comparable to controls, using all facial features to (de)code facial expressions with the exception of fear. PS's normal (de)coding of dynamic facial expressions suggests that the face system relies either on distinct representational systems for identity and expression, or dissociable cortical pathways to access them. Interestingly, PS showed a selective impairment for categorizing many static facial expressions, which could be accounted for by her lesion in the right inferior occipital gyrus. PS's advantage for dynamic facial expressions might instead relate to a functionally distinct and sufficient cortical pathway directly connecting the early visual cortex to the spared pSTS. Altogether, our data provide critical insights on the healthy and impaired face systems, question evidence of deficits

  1. Platelet-activating factor induces phospholipid turnover, calcium flux, arachidonic acid liberation, eicosanoid generation, and oncogene expression in a human B cell line

    SciTech Connect

    Schulam, P.G.; Kuruvilla, A.; Putcha, G.; Mangus, L.; Franklin-Johnson, J.; Shearer, W.T. )

    1991-03-01

    Platelet-activating factor is a potent mediator of the inflammatory response. Studies of the actions of platelet-activating factor have centered mainly around neutrophils, monocytes, and platelets. In this report we begin to uncover the influence of platelet-activating factor on B lymphocytes. Employing the EBV-transformed human B cell line SKW6.4, we demonstrate that platelet-activating factor significantly alters membrane phospholipid metabolism indicated by the incorporation of 32P into phosphatidylcholine, phosphatidylinositol, and phosphatidic acid but not significantly into phosphatidylethanolamine at concentrations ranging from 10(-9) to 10(-6) M. The inactive precursor, lyso-platelet-activating factor, at a concentration as high as 10(-7) M had no effect on any of the membrane phospholipids. We also show that platelet-activating factor from 10(-12) to 10(-6) M induced rapid and significant elevation in intracellular calcium levels, whereas lyso-platelet-activating factor was again ineffective. We further demonstrate the impact of platelet-activating factor binding to B cells by measuring platelet-activating factor induced arachidonic acid release and 5-hydroxyeicosatetraenoic acid production. Moreover, platelet-activating factor was capable of inducing transcription of the nuclear proto-oncogenes c-fos and c-jun. Finally we explored the possible role of 5-hydroxyeicosatetraenoic acid as a regulator of arachidonic acid liberation demonstrating that endogenous 5-lipoxygenase activity modulates platelet-activating factor induced arachidonic acid release perhaps acting at the level of phospholipase A2. In summary, platelet-activating factor is shown here to have a direct and profound effect on a pure B cell line.

  2. Principles of Cancer Therapy: Oncogene and Non-oncogene Addiction

    PubMed Central

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

    2010-01-01

    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

  3. 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

  4. Pancreatitis promotes oncogenic KrasG12D-induced pancreatic transformation through activation of Nupr1

    PubMed Central

    Grasso, Daniel; Garcia, Maria Noé; Hamidi, Tewfik; Cano, Carla; Calvo, Ezequiel; Lomberk, Gwen; Urrutia, Raul; Iovanna, Juan L

    2014-01-01

    During the initiation stage of pancreatic adenocarcinoma induced by oncogenic Kras, pancreatic cells are exposed to both a protumoral effect and an opposing tumor suppressive process known as oncogene-induced senescence. Pancreatitis disrupts this balance in favor of the transforming effect of oncogenes by lowering the tumor suppressive threshold of oncogene-induced senescence through expression of the stress protein Nupr1. PMID:27308320

  5. 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

  6. The DNA binding site of the Dof protein NtBBF1 is essential for tissue-specific and auxin-regulated expression of the rolB oncogene in plants.

    PubMed Central

    Baumann, K; De Paolis, A; Costantino, P; Gualberti, G

    1999-01-01

    The Dof proteins are a large family of plant transcription factors that share a single highly conserved zinc finger. The tobacco Dof protein NtBBF1 was identified by its ability to bind to regulatory domain B in the promoter of the rolB oncogene. In this study, we show that the ACT T TA target sequence of NtBBF1 in domain B is necessary for tissue-specific expression of rolB. beta-Glucuronidase (GUS) activity of tobacco plants containing a rolB promoter-GUS fusion with a mutated NtBBF1 target sequence within domain B is almost completely suppressed in apical meristems and is severely abated in the vascular system. The ACT T TA motif is shown here also to be one of the cis-regulatory elements involved in auxin induction of rolB. The pattern of NtBBF1 expression in plants is remarkably similar to that of rolB, except in mesophyll cells of mature leaves, in which only NtBBF1 expression could be detected. Ectopic expression of rolB in mesophyll cells was achieved by particle gun delivery if the NtBBF1 binding sequence was intact. These data provide evidence that in the plant, a Dof protein DNA binding sequence acts as a transcriptional regulatory motif, and they point to NtBBF1 as the protein involved in mediating tissue-specific and auxin-inducible expression of rolB. PMID:10072394

  7. Investigation of Astragalus honey and propolis extract's cytotoxic effect on two human cancer cell lines and their oncogen and proapoptotic gene expression profiles

    PubMed Central

    Sadeghi-Aliabadi, Hojjat; Hamzeh, Jamal; Mirian, Mina

    2015-01-01

    Background: Cancer is one of the major fatal human diseases. Natural products have been used in the treatment of cancer for long time. Bee products including honey and propolis have been introduced for malignancy treatment in recent decades. In this study cytotoxicity of bee products and their effects on the expression of proapoptotic genes have been investigated. Materials and Methods: Cytotoxic effects of Astragalus honey, ethanol extract of propolis and a sugar solution (as control) against HepG2, 5637 and L929 cell lines have been evaluated by the MTT assay. Total RNAs of treated cells were isolated and p53 and Bcl-2 gene expression were evaluated, using real-time PCR. Results: Propolis IC50 values were 58, 30 and 15 μg/ml against L929, HepG2 and 5637, respectively. These values for honey were 3.1%, 2.4% and 1.9%, respectively. Propolis extract has increased the expression of the Bcl-2 gene in all cell lines whereas the honey decreased that significantly (P < 0.05). Also, we found that honey and propolis decreased p53 gene expression in HepG2 and 5637 significantly but not in L929 cells. The sugar solution increased the expression of p53 in two cancer cell lines but no significant changes were observed in the expression of this gene in L929 as normal mouse cell. Conclusion: By downregulation of Bcl-2 expression it could be concluded that the cytotoxicity of honey was more than two fold against tested cancer cells compared with the sugar solution. No significant changes were observed in the expression of p53 in honey-treated cells. Propolis had no significant effect on Bcl-2 and p53 gene expressions (P > 0.05). PMID:25789268

  8. NF-kB and c-Jun induce the expression of the oncogenic miR-221 and miR-222 in prostate carcinoma and glioblastoma cells.

    PubMed

    Galardi, Silvia; Mercatelli, Neri; Farace, Maria G; Ciafrè, Silvia A

    2011-05-01

    MicroRNAs (miRNAs) are potent negative regulators of gene expression involved in all aspects of cell biology. They finely modulate virtually all physiological pathways in metazoans, and are deeply implicated in all main pathologies, among which cancer. Mir-221 and miR-222, two closely related miRNAs encoded in cluster from a genomic region on chromosome X, are strongly upregulated in several forms of human tumours. In this work, we report that the ectopic modulation of NF-kB modifies miR-221/222 expression in prostate carcinoma and glioblastoma cell lines, where we had previously shown their oncogenic activity. We identify two separate distal regions upstream of miR-221/222 promoter which are bound by the NF-kB subunit p65 and drive efficient transcription in luciferase reporter assays; consistently, the site-directed mutagenesis disrupting p65 binding sites or the ectopical inhibition of NF-kB activity significantly reduce luciferase activity. In the most distal enhancer region, we also define a binding site for c-Jun, and we show that the binding of this factor cooperates with that of p65, fully accounting for the observed upregulation of miR-221/222. Thus our work uncovers an additional mechanism through which NF-kB and c-Jun, two transcription factors deeply involved in cancer onset and progression, contribute to oncogenesis, by inducing miR-221/222 transcription. PMID:21245048

  9. NF-kB and c-Jun induce the expression of the oncogenic miR-221 and miR-222 in prostate carcinoma and glioblastoma cells

    PubMed Central

    Galardi, Silvia; Mercatelli, Neri; Farace, Maria G.; Ciafrè, Silvia A.

    2011-01-01

    MicroRNAs (miRNAs) are potent negative regulators of gene expression involved in all aspects of cell biology. They finely modulate virtually all physiological pathways in metazoans, and are deeply implicated in all main pathologies, among which cancer. Mir-221 and miR-222, two closely related miRNAs encoded in cluster from a genomic region on chromosome X, are strongly upregulated in several forms of human tumours. In this work, we report that the ectopic modulation of NF-kB modifies miR-221/222 expression in prostate carcinoma and glioblastoma cell lines, where we had previously shown their oncogenic activity. We identify two separate distal regions upstream of miR-221/222 promoter which are bound by the NF-kB subunit p65 and drive efficient transcription in luciferase reporter assays; consistently, the site-directed mutagenesis disrupting p65 binding sites or the ectopical inhibition of NF-kB activity significantly reduce luciferase activity. In the most distal enhancer region, we also define a binding site for c-Jun, and we show that the binding of this factor cooperates with that of p65, fully accounting for the observed upregulation of miR-221/222. Thus our work uncovers an additional mechanism through which NF-kB and c-Jun, two transcription factors deeply involved in cancer onset and progression, contribute to oncogenesis, by inducing miR-221/222 transcription. PMID:21245048

  10. 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

  11. Novel insights of the gastric gland organization revealed by chief cell specific expression of moesin.

    PubMed

    Zhu, Lixin; Hatakeyama, Jason; Zhang, Bing; Makdisi, Joy; Ender, Cody; Forte, John G

    2009-02-01

    ERM (ezrin, radixin, and moesin) proteins play critical roles in epithelial and endothelial cell polarity, among other functions. In gastric glands, ezrin is mainly expressed in acid-secreting parietal cells, but not in mucous neck cells or zymogenic chief cells. In looking for other ERM proteins, moesin was found lining the lumen of much of the gastric gland, but it was not expressed in parietal cells. No significant radixin expression was detected in the gastric glands. Moesin showed an increased gradient of expression from the neck to the base of the glands. In addition, the staining pattern of moesin revealed a branched morphology for the gastric lumen. This pattern of short branches extending from the glandular lumen was confirmed by using antibody against zonula occludens-1 (ZO-1) to stain tight junctions. With a mucous neck cell probe (lectin GSII, from Griffonia simplicifolia) and a chief cell marker (pepsinogen C), immunohistochemistry revealed that the mucous neck cells at the top of the glands do not express moesin, but, progressing toward the base, mucous cells showing decreased GSII staining had low or moderate level of moesin expression. The level of moesin expression continued to increase toward the base of the glands and reached a plateau in the base where chief cells and parietal cells abound. The level of pepsinogen expression also increased toward the base. Pepsinogen C was located on cytoplasmic granules and/or more generally distributed in chief cells, whereas moesin was exclusively expressed on the apical membrane. This is a clear demonstration of distinctive cellular expression of two ERM family members in the same tissue. The results provide the first evidence that moesin is involved in the cell biology of chief cells. Novel insights on gastric gland morphology revealed by the moesin and ZO-1 staining provide the basis for a model of cell maturation and migration within the gland. PMID:19074636

  12. Novel insights of the gastric gland organization revealed by chief cell specific expression of moesin

    PubMed Central

    Zhu, Lixin; Hatakeyama, Jason; Zhang, Bing; Makdisi, Joy; Ender, Cody; Forte, John G.

    2009-01-01

    ERM (ezrin, radixin, and moesin) proteins play critical roles in epithelial and endothelial cell polarity, among other functions. In gastric glands, ezrin is mainly expressed in acid-secreting parietal cells, but not in mucous neck cells or zymogenic chief cells. In looking for other ERM proteins, moesin was found lining the lumen of much of the gastric gland, but it was not expressed in parietal cells. No significant radixin expression was detected in the gastric glands. Moesin showed an increased gradient of expression from the neck to the base of the glands. In addition, the staining pattern of moesin revealed a branched morphology for the gastric lumen. This pattern of short branches extending from the glandular lumen was confirmed by using antibody against zonula occludens-1 (ZO-1) to stain tight junctions. With a mucous neck cell probe (lectin GSII, from Griffonia simplicifolia) and a chief cell marker (pepsinogen C), immunohistochemistry revealed that the mucous neck cells at the top of the glands do not express moesin, but, progressing toward the base, mucous cells showing decreased GSII staining had low or moderate level of moesin expression. The level of moesin expression continued to increase toward the base of the glands and reached a plateau in the base where chief cells and parietal cells abound. The level of pepsinogen expression also increased toward the base. Pepsinogen C was located on cytoplasmic granules and/or more generally distributed in chief cells, whereas moesin was exclusively expressed on the apical membrane. This is a clear demonstration of distinctive cellular expression of two ERM family members in the same tissue. The results provide the first evidence that moesin is involved in the cell biology of chief cells. Novel insights on gastric gland morphology revealed by the moesin and ZO-1 staining provide the basis for a model of cell maturation and migration within the gland. PMID:19074636

  13. Whole Genome Expression Analysis Reveals Differential Effects of TiO2 Nanotubes on Vascular Cells

    PubMed Central

    Peng, Lily; Barczak, Andrea J.; Barbeau, Rebecca A.; Xiao, Yuanyuan; LaTempa, Thomas J.; Grimes, Craig A.; Desai, Tejal A.

    2010-01-01

    The response of primary human endothelial (ECs) and vascular smooth muscle cells (VSMCs) to TiO2 nanotube arrays is studied through gene expression analysis. Microarrays revealed that nanotubes enhanced EC proliferation and motility, decreased VSMC proliferation, and decreased expression of molecules involved in inflammation and coagulation in both cell types. Networks generated from significantly affected genes suggest that cells may be sensing nanotopographical cues via pathways previously implicated in sensing shear stress. PMID:20030358

  14. Leucine leucine-37 uses formyl peptide receptor-like 1 to activate signal transduction pathways, stimulate oncogenic gene expression, and enhance the invasiveness of ovarian cancer cells.

    PubMed

    Coffelt, Seth B; Tomchuck, Suzanne L; Zwezdaryk, Kevin J; Danka, Elizabeth S; Scandurro, Aline B

    2009-06-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor-like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein-coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37-induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37-stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37-treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  15. Leucine Leucine-37 Uses Formyl Peptide Receptor–Like 1 to Activate Signal Transduction Pathways, Stimulate Oncogenic Gene Expression, and Enhance the Invasiveness of Ovarian Cancer Cells

    PubMed Central

    Coffelt, Seth B.; Tomchuck, Suzanne L.; Zwezdaryk, Kevin J.; Danka, Elizabeth S.; Scandurro, Aline B.

    2009-01-01

    Emerging evidence suggests that the antimicrobial peptide, leucine leucine-37 (LL-37), could play a role in the progression of solid tumors. LL-37 is expressed as the COOH terminus of human cationic antimicrobial protein-18 (hCAP-18) in ovarian, breast, and lung cancers. Previous studies have shown that the addition of LL-37 to various cancer cell lines in vitro stimulates proliferation, migration, and invasion. Similarly, overexpression of hCAP-18/LL-37 in vivo accelerates tumor growth. However, the receptor or receptors through which these processes are mediated have not been thoroughly examined. In the present study, expression of formyl peptide receptor–like 1 (FPRL1) was confirmed on ovarian cancer cells. Proliferation assays indicated that LL-37 does not signal through a G protein–coupled receptor, such as FPRL1, to promote cancer cell growth. By contrast, FPRL1 was required for LL-37–induced invasion through Matrigel. The peptide stimulated mitogen-activated protein kinase and Janus-activated kinase/signal transducers and activators of transcription signaling cascades and led to the significant activation of several transcription factors, through both FPRL1-dependent and FPRL1-independent pathways. Likewise, expression of some LL-37–stimulated genes was attenuated by the inhibition of FPRL1. Increased expression of CXCL10, EGF, and PDGF-BB as well as other soluble factors was confirmed from conditioned medium of LL-37–treated cells. Taken together, these data suggest that LL-37 potentiates a more aggressive behavior from ovarian cancer cells through its interaction with FPRL1. PMID:19491199

  16. Oncogenic role of nucleophosmin/B23.

    PubMed

    Yung, Benjamin Yat Ming

    2007-01-01

    Nucleophosmin/B23 was first identified as a nucleolar protein expressed at higher levels in cancer cells compared to normal cells. Nucleophosmin/B23 has long been thus thought to have a role in tumor formation. With our efforts and others in the last 15 years, nucleophosmin/B23 has proven to have an oncogenic role. In this review, we provide evidence suggesting that nucleophosmin/B23 may be a crucial gene in regulation of cancer growth and discuss how nucleophosmin/B23 can contribute to tumorigenesis. PMID:17939258

  17. In-gel imaging of RNA processing using Broccoli reveals optimal aptamer expression strategies

    PubMed Central

    Filonov, Grigory S.; Kam, Christina W.; Song, Wenjiao; Jaffrey, Samie R.

    2015-01-01

    SUMMARY RNA aptamers can be expressed in cells to influence and image cellular processes. Aptamer folding is maintained by inserting the aptamers into highly structured RNA scaffolds. Here we show that commonly used RNA scaffolds exhibit unexpected instability and cleavage in bacterial and mammalian cells. Using an in-gel staining approach for rapid and simple detection of Spinach- or Broccoli-tagged RNAs in cells, we monitored the processing of RNAs tagged with scaffolded aptamers, revealing endonucleolytic cleavage, RNA instability and poor expression. We reengineered a natural three-way junction structure to generate an alternative scaffold that enables stable aptamer expression in cells. This scaffold was used to create cassettes containing up to four Broccoli units, markedly enhancing the brightness of mammalian cells expressing cassette-tagged RNAs. These experiments describe methods for screening RNA cleavage events in cells, and identify cell-compatible scaffolds that enable efficient tagging of RNAs with aptamers for cellular expression. PMID:26000751

  18. Analysis of spatial-temporal gene expression patterns reveals dynamics and regionalization in developing mouse brain

    PubMed Central

    Chou, Shen-Ju; Wang, Chindi; Sintupisut, Nardnisa; Niou, Zhen-Xian; Lin, Chih-Hsu; Li, Ker-Chau; Yeang, Chen-Hsiang

    2016-01-01

    Allen Brain Atlas (ABA) provides a valuable resource of spatial/temporal gene expressions in mammalian brains. Despite rich information extracted from this database, current analyses suffer from several limitations. First, most studies are either gene-centric or region-centric, thus are inadequate to capture the superposition of multiple spatial-temporal patterns. Second, standard tools of expression analysis such as matrix factorization can capture those patterns but do not explicitly incorporate spatial dependency. To overcome those limitations, we proposed a computational method to detect recurrent patterns in the spatial-temporal gene expression data of developing mouse brains. We demonstrated that regional distinction in brain development could be revealed by localized gene expression patterns. The patterns expressed in the forebrain, medullary and pontomedullary, and basal ganglia are enriched with genes involved in forebrain development, locomotory behavior, and dopamine metabolism respectively. In addition, the timing of global gene expression patterns reflects the general trends of molecular events in mouse brain development. Furthermore, we validated functional implications of the inferred patterns by showing genes sharing similar spatial-temporal expression patterns with Lhx2 exhibited differential expression in the embryonic forebrains of Lhx2 mutant mice. These analysis outcomes confirm the utility of recurrent expression patterns in studying brain development. PMID:26786896

  19. 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.

  20. GENES FOR TUMOR MARKERS ARE CLUSTERED WITH CELLULAR PROTO-ONCOGENES ON HUMAN CHROMOSOMES

    EPA Science Inventory

    The relative mapping positions of genes for polypeptides expressed abnormally in tumors (tumor markers) and cellular proto-oncogenes were analyzed and a remarkable degree of co-mapping of tumor marker genes with oncogenes in the human karyotype were found. It is proposed that abe...

  1. 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

  2. Gene expression profiling reveals molecularly and clinically distinct subtypes of glioblastoma multiforme

    PubMed Central

    Liang, Yu; Diehn, Maximilian; Watson, Nathan; Bollen, Andrew W.; Aldape, Ken D.; Nicholas, M. Kelly; Lamborn, Kathleen R.; Berger, Mitchel S.; Botstein, David; Brown, Patrick O.; Israel, Mark A.

    2005-01-01

    Glioblastoma multiforme (GBM) is the most common form of malignant glioma, characterized by genetic instability, intratumoral histopathological variability, and unpredictable clinical behavior. We investigated global gene expression in surgical samples of brain tumors. Gene expression profiling revealed large differences between normal brain samples and tumor tissues and between GBMs and lower-grade oligodendroglial tumors. Extensive differences in gene expression were found among GBMs, particularly in genes involved in angiogenesis, immune cell infiltration, and extracellular matrix remodeling. We found that the gene expression patterns in paired specimens from the same GBM invariably were more closely related to each other than to any other tumor, even when the paired specimens had strikingly divergent histologies. Survival analyses revealed a set of ≈70 genes more highly expressed in rapidly progressing tumors that stratified GBMs into two groups that differed by >4-fold in median duration of survival. We further investigated one gene from the group, FABP7, and confirmed its association with survival in two unrelated cohorts totaling 105 patients. Expression of FABP7 enhanced the motility of glioma-derived cells in vitro. Our analyses thus identify and validate a prognostic marker of both biologic and clinical significance and provide a series of putative markers for additional evaluation. PMID:15827123

  3. Genome-wide analysis reveals gene expression and metabolic network dynamics during embryo development in Arabidopsis.

    PubMed

    Xiang, Daoquan; Venglat, Prakash; Tibiche, Chabane; Yang, Hui; Risseeuw, Eddy; Cao, Yongguo; Babic, Vivijan; Cloutier, Mathieu; Keller, Wilf; Wang, Edwin; Selvaraj, Gopalan; Datla, Raju

    2011-05-01

    Embryogenesis is central to the life cycle of most plant species. Despite its importance, because of the difficulty associated with embryo isolation, global gene expression programs involved in plant embryogenesis, especially the early events following fertilization, are largely unknown. To address this gap, we have developed methods to isolate whole live Arabidopsis (Arabidopsis thaliana) embryos as young as zygote and performed genome-wide profiling of gene expression. These studies revealed insights into patterns of gene expression relating to: maternal and paternal contributions to zygote development, chromosomal level clustering of temporal expression in embryogenesis, and embryo-specific functions. Functional analysis of some of the modulated transcription factor encoding genes from our data sets confirmed that they are critical for embryogenesis. Furthermore, we constructed stage-specific metabolic networks mapped with differentially regulated genes by combining the microarray data with the available Kyoto Encyclopedia of Genes and Genomes metabolic data sets. Comparative analysis of these networks revealed the network-associated structural and topological features, pathway interactions, and gene expression with reference to the metabolic activities during embryogenesis. Together, these studies have generated comprehensive gene expression data sets for embryo development in Arabidopsis and may serve as an important foundational resource for other seed plants. PMID:21402797

  4. Single-cell gene expression profiling reveals functional heterogeneity of undifferentiated human epidermal cells

    PubMed Central

    Tan, David W. M.; Jensen, Kim B.; Trotter, Matthew W. B.; Connelly, John T.; Broad, Simon; Watt, Fiona M.

    2013-01-01

    Human epidermal stem cells express high levels of β1 integrins, delta-like 1 (DLL1) and the EGFR antagonist LRIG1. However, there is cell-to-cell variation in the relative abundance of DLL1 and LRIG1 mRNA transcripts. Single-cell global gene expression profiling showed that undifferentiated cells fell into two clusters delineated by expression of DLL1 and its binding partner syntenin. The DLL1+ cluster had elevated expression of genes associated with endocytosis, integrin-mediated adhesion and receptor tyrosine kinase signalling. Differentially expressed genes were not independently regulated, as overexpression of DLL1 alone or together with LRIG1 led to the upregulation of other genes in the DLL1+ cluster. Overexpression of DLL1 and LRIG1 resulted in enhanced extracellular matrix adhesion and increased caveolin-dependent EGFR endocytosis. Further characterisation of CD46, one of the genes upregulated in the DLL1+ cluster, revealed it to be a novel cell surface marker of human epidermal stem cells. Cells with high endogenous levels of CD46 expressed high levels of β1 integrin and DLL1 and were highly adhesive and clonogenic. Knockdown of CD46 decreased proliferative potential and β1 integrin-mediated adhesion. Thus, the previously unknown heterogeneity revealed by our studies results in differences in the interaction of undifferentiated basal keratinocytes with their environment. PMID:23482486

  5. Differential protein expression and oncogenic gene network link tyrosine kinase ephrin B4 receptor to aggressive gastric and gastroesophageal junction cancers.

    PubMed

    Liersch-Löhn, Britta; Slavova, Nadia; Buhr, Heinz J; Bennani-Baiti, Idriss M

    2016-03-01

    Transmembrane tyrosine-kinase Ephrin receptors promote tumor progression and/or metastasis of several malignancies including leukemia, follicular lymphoma, glioma, malignant pleural mesothelioma, papillary thyroid carcinoma, sarcomas and ovarian, breast, bladder and non-small cell lung cancers. They also drive intestinal stem cell proliferation and positioning, control intestinal tissue boundaries and are involved in liver, pancreatic and colorectal cancers, indicating involvement in additional digestive system malignancies. We investigated the role of Ephrin-B4 receptor (EPHB4), and its ligand EFNB2, in gastric and gastroesophageal junction cancers in patient cohorts through computational, mathematical, molecular and immunohistochemical analyses. We show that EPHB4 is upregulated in preneoplastic gastroesophageal lesions and its expression further increased in gastroesophageal cancers in several independent cohorts. The closely related EPHB6 receptor, which also binds EFNB2, was downregulated in all tested cohorts, consistent with its tumor-suppressive properties in other cancers. EFNB2 expression is induced in esophageal cells by acidity, suggesting that gastroesophageal reflux disease (GERD) may constitute an early triggering event in activating EFNB2-EPHB4 signaling. Association of EPHB4 to both Barrett's esophagus and to advanced tumor stages, and its overexpression at the tumor invasion front and vascular endothelial cells intimate the notion that EPHB4 may be associated with multiple steps of gastroesophageal tumorigenesis. Analysis of oncogenomic signatures uncovered the first EPHB4-associated gene network (false discovery rate: 7 × 10(-90) ) composed of a five-transcription factor interconnected gene network that drives proliferation, angiogenesis and invasiveness. The EPHB4 oncogenomic network provides a molecular basis for its role in tumor progression and points to EPHB4 as a potential tumor aggressiveness biomarker and drug target in gastroesophageal

  6. Identification of MYC-Dependent Transcriptional Programs in Oncogene-Addicted Liver Tumors.

    PubMed

    Kress, Theresia R; Pellanda, Paola; Pellegrinet, Luca; Bianchi, Valerio; Nicoli, Paola; Doni, Mirko; Recordati, Camilla; Bianchi, Salvatore; Rotta, Luca; Capra, Thelma; Ravà, Micol; Verrecchia, Alessandro; Radaelli, Enrico; Littlewood, Trevor D; Evan, Gerard I; Amati, Bruno

    2016-06-15

    Tumors driven by activation of the transcription factor MYC generally show oncogene addiction. However, the gene expression programs that depend upon sustained MYC activity remain unknown. In this study, we employed a mouse model of liver carcinoma driven by a reversible tet-MYC transgene, combined with chromatin immunoprecipitation and gene expression profiling to identify MYC-dependent regulatory events. As previously reported, MYC-expressing mice exhibited hepatoblastoma- and hepatocellular carcinoma-like tumors, which regressed when MYC expression was suppressed. We further show that cellular transformation, and thus initiation of liver tumorigenesis, were impaired in mice harboring a MYC mutant unable to associate with the corepressor protein MIZ1 (ZBTB17). Notably, switching off the oncogene in advanced carcinomas revealed that MYC was required for the continuous activation and repression of distinct sets of genes, constituting no more than half of all genes deregulated during tumor progression and an even smaller subset of all MYC-bound genes. Altogether, our data provide the first detailed analysis of a MYC-dependent transcriptional program in a fully developed carcinoma and offer a guide to identifying the critical effectors contributing to MYC-driven tumor maintenance. Cancer Res; 76(12); 3463-72. ©2016 AACR. PMID:27197165

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

    PubMed

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

    2015-08-01

    Many human cancers share similar metabolic alterations, including the Warburg effect. However, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Here we demonstrate a "synthetic lethal" interaction between oncogenic BRAF V600E and a ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL). HMGCL expression is upregulated in BRAF V600E-expressing human primary melanoma and hairy cell leukemia cells. Suppression of HMGCL specifically attenuates proliferation and tumor growth potential of human melanoma cells expressing BRAF V600E. Mechanistically, active BRAF upregulates HMGCL through an octamer transcription factor Oct-1, leading to increased intracellular levels of HMGCL product, acetoacetate, which selectively enhances binding of BRAF V600E but not BRAF wild-type to MEK1 in V600E-positive cancer cells to promote activation of MEK-ERK signaling. These findings reveal a mutation-specific mechanism by which oncogenic BRAF V600E "rewires" metabolic and cell signaling networks and signals through the Oct-1-HMGCL-acetoacetate axis to selectively promote BRAF V600E-dependent tumor development. PMID:26145173

  8. TPR-MET oncogenic rearrangement: Detection by polymerase chain reaction amplification of the transcript and expression in human tumor cells lines

    SciTech Connect

    Soman, N.R.; Wogan, G.N. ); Rhim, J.S. )

    1990-01-01

    Activation of the MET protooncogene by a rearrangement involving the fusion of TPR and MET specific gene sequences has been observed in a human osteosarcoma cell line (HOS) treated in vitro with N-methyl-N{prime}-nitro-N-nitrosoguanidine (MNNG). No information has been available about the possible occurrence of this rearrangement in human tumors. To facilitate rapid screening of human cell lines and tumor samples for this specific gene rearrangement; the authors developed a sensitive detection method based on polymerase chain reaction (PCR) amplification of TPR-MET mRNA. cDNA was generated from cellular transcripts by using one of the PCR primers, which was then used as a template for PCR amplification of a 205-base-pair region carrying the breakpoint. An end-labeled internal probe was hybridized in solution to an aliquot of the PCR product for detecting amplification. Cells could be directly screened by the assay without prior isolation of RNA. A 205-base-pair DNA fragment characteristic of the TRP-MET rearrangement was detected in cell lines previously known to contain this altered sequence. The rearrangement was also detected at very low levels in the parental (nontransformed) cell line, HOS TE-85. A preliminary survey of cell lines derived from a variety of human tumors indicates that TPR-MET rearrangement occurred and was expressed at very low frequencies by cells from 7 of 14 tumors of nonhematopoietic origin.

  9. A new engineering approach to reveal correlation of physiological change and spontaneous expression from video images

    NASA Astrophysics Data System (ADS)

    Yang, Fenglei; Hu, Sijung; Ma, Xiaoyun; Hassan, Harnani; Wei, Dongqing

    2015-03-01

    Spontaneous expression is associated with physiological states, i.e., heart rate, respiration, oxygen saturation (SpO2%), and heart rate variability (HRV). There have yet not sufficient efforts to explore correlation of physiological change and spontaneous expression. This study aims to study how spontaneous expression is associated with physiological changes with an approved protocol or through the videos provided from Denver Intensity of Spontaneous Facial Action Database. Not like a posed expression, motion artefact in spontaneous expression is one of evitable challenges to be overcome in the study. To obtain a physiological signs from a region of interest (ROI), a new engineering approach is being developed with an artefact-reduction method consolidated 3D active appearance model (AAM) based track, affine transformation based alignment with opto-physiological mode based imaging photoplethysmography. Also, a statistical association spaces is being used to interpret correlation of spontaneous expressions and physiological states including their probability densities by means of Gaussian Mixture Model. The present work is revealing a new avenue of study associations of spontaneous expressions and physiological states with its prospect of applications on physiological and psychological assessment.

  10. miR-17–92 explains MYC oncogene addiction

    PubMed Central

    Li, Yulin; Casey, Stephanie C; Choi, Peter S; Felsher, Dean W

    2014-01-01

    MYC regulates tumorigenesis by coordinating the expression of thousands of genes. We found that MYC appears to regulate the decisions between cell survival versus death and self-renewal versus senescence through the microRNA miR-17–92 cluster. Addiction to the MYC oncogene may therefore in fact be an addiction to miR-17–92. PMID:27308380

  11. Authentic and play-acted vocal emotion expressions reveal acoustic differences.

    PubMed

    Jürgens, Rebecca; Hammerschmidt, Kurt; Fischer, Julia

    2011-01-01

    Play-acted emotional expressions are a frequent aspect in our life, ranging from deception to theater, film, and radio drama, to emotion research. To date, however, it remained unclear whether play-acted emotions correspond to spontaneous emotion expressions. To test whether acting influences the vocal expression of emotion, we compared radio sequences of naturally occurring emotions to actors' portrayals. It was hypothesized that play-acted expressions were performed in a more stereotyped and aroused fashion. Our results demonstrate that speech segments extracted from play-acted and authentic expressions differ in their voice quality. Additionally, the play-acted speech tokens revealed a more variable F(0)-contour. Despite these differences, the results did not support the hypothesis that the variation was due to changes in arousal. This analysis revealed that differences in perception of play-acted and authentic emotional stimuli reported previously cannot simply be attributed to differences in arousal, but by slight and implicitly perceptible differences in encoding. PMID:21847385

  12. Authentic and Play-Acted Vocal Emotion Expressions Reveal Acoustic Differences

    PubMed Central

    Jürgens, Rebecca; Hammerschmidt, Kurt; Fischer, Julia

    2011-01-01

    Play-acted emotional expressions are a frequent aspect in our life, ranging from deception to theater, film, and radio drama, to emotion research. To date, however, it remained unclear whether play-acted emotions correspond to spontaneous emotion expressions. To test whether acting influences the vocal expression of emotion, we compared radio sequences of naturally occurring emotions to actors’ portrayals. It was hypothesized that play-acted expressions were performed in a more stereotyped and aroused fashion. Our results demonstrate that speech segments extracted from play-acted and authentic expressions differ in their voice quality. Additionally, the play-acted speech tokens revealed a more variable F0-contour. Despite these differences, the results did not support the hypothesis that the variation was due to changes in arousal. This analysis revealed that differences in perception of play-acted and authentic emotional stimuli reported previously cannot simply be attributed to differences in arousal, but by slight and implicitly perceptible differences in encoding. PMID:21847385

  13. Photodynamic treatment (ALA-PDT) suppresses the expression of the oncogenic Bcr-Abl kinase and affects the cytoskeleton organization in K562 cells.

    PubMed

    Pluskalová, Michaela; Peslová, Gabriela; Grebenová, Dana; Halada, Petr; Hrkal, Zbynek

    2006-06-01

    K562 is the chronic myelogenous leukemia (CML)-derived cell line that expresses high levels of chimeric oncoprotein Bcr-Abl. The deregulated (permanent) kinase activity of Bcr-Abl leads to continuous proliferation of K562 cells and their resistance to the apoptosis promotion by conventional drugs. The photodynamic treatment (PDT) based on the application of 5-aminolevulinic acid (ALA) and irradiation with blue light (ALA-PDT) resulted in the suppression of K562 cells proliferation. It was followed by a necrosis-like cell death [K. Kuzelová, D. Grebenová, M. Pluskalová, I. Marinov, Z. Hrkal, J. Photochem. Photobiol. B 73 (2004) 67-78]. ALA-PDT led to the perturbation of the Hsp90/p23 multichaperone complex of which the Bcr-Abl is the client protein. Bcr-Abl protein was suppressed whereas the bcr-abl mRNA level was not affected. Further on, we observed several changes in the cytoskeleton organization. We detected ALA-PDT-mediated disruption of filamental actin structure using FITC-Phalloidin staining. In connection with this we uncovered certain cytoskeleton organizing proteins involved in the cell response to the treatment. Among these proteins, Septin2, which plays a role in maintaining actin bundles, was suppressed. Another one, PDZ-LIM domain protein 1 (CLP36) was altered. This protein acts as an adaptor molecule for LIM-kinase which phosphorylates and thus inactivates cofilin. Cofilin was indeed dephosphorylated and could thus be activated and operate as an actin-depolymerizing factor. We propose the scheme of molecular response of K562 cells to ALA-PDT. PMID:16495075

  14. Comparative genomics reveals tissue-specific regulation of prolactin receptor gene expression.

    PubMed

    Schennink, Anke; Trott, Josephine F; Manjarin, Rodrigo; Lemay, Danielle G; Freking, Bradley A; Hovey, Russell C

    2015-02-01

    Prolactin (PRL), acting via the PRL receptor (PRLR), controls hundreds of biological processes across a range of species. Endocrine PRL elicits well-documented effects on target tissues such as the mammary glands and reproductive organs in addition to coordinating whole-body homeostasis during states such as lactation or adaptive responses to the environment. While changes in PRLR expression likely facilitates these tissue-specific responses to circulating PRL, the mechanisms regulating this regulation in non-rodent species has received limited attention. We performed a wide-scale analysis of PRLR 5' transcriptional regulation in pig tissues. Apart from the abundantly expressed and widely conserved exon 1, we identified alternative splicing of transcripts from an additional nine first exons of the porcine PRLR (pPRLR) gene. Notably, exon 1.5 transcripts were expressed most abundantly in the heart, while expression of exon 1.3-containing transcripts was greatest in the kidneys and small intestine. Expression of exon 1.3 mRNAs within the kidneys was most abundant in the renal cortex, and increased during gestation. A comparative analysis revealed a human homologue to exon 1.3, hE1N2, which was also principally transcribed in the kidneys and small intestines, and an exon hE1N3 was only expressed in the kidneys of humans. Promoter alignment revealed conserved motifs within the proximal promoter upstream of exon 1.3, including putative binding sites for hepatocyte nuclear factor-1 and Sp1. Together, these results highlight the diverse, conserved and tissue-specific regulation of PRLR expression in the targets for PRL, which may function to coordinate complex physiological states such as lactation and osmoregulation. PMID:25358647

  15. Oncogenic Ras/Src cooperativity in pancreatic neoplasia

    PubMed Central

    Shields, DJ; Murphy, EA; Desgrosellier, JS; Mielgo, A; Lau, SKM; Barnes, LA; Lesperance, J; Huang, M; Schmedt, C; Tarin, D; Lowy, AM; Cheresh, DA

    2011-01-01

    Pancreas cancer is one of the most lethal malignancies and is characterized by activating mutations of Kras, present in 95% of patients. More than 60% of pancreatic cancers also display increased c-Src activity, which is associated with poor prognosis. Although loss of tumor suppressor function (for example, p16, p53, Smad4) combined with oncogenic Kras signaling has been shown to accelerate pancreatic duct carcinogenesis, it is unclear whether elevated Src activity contributes to Kras-dependent tumorigenesis or is simply a biomarker of disease progression. Here, we demonstrate that in the context of oncogenic Kras, activation of c-Src through deletion of C-terminal Src kinase (CSK) results in the development of invasive pancreatic ductal adenocarcinoma (PDA) by 5–8 weeks. In contrast, deletion of CSK alone fails to induce neoplasia, while oncogenic Kras expression yields PDA at low frequency after a latency of 12 months. Analysis of cell lines derived from Ras/Src-induced PDA’s indicates that oncogenic Ras/Src cooperativity may lead to genomic instability, yet Ras/Src-driven tumor cells remain dependent on Src signaling and as such, Src inhibition suppresses growth of Ras/Src-driven tumors. These findings demonstrate that oncogenic Ras/Src cooperate to accelerate PDA onset and support further studies of Src-directed therapies in pancreatic cancer. PMID:21242978

  16. Single chromosome transcriptional profiling reveals chromosome-level regulation of gene expression

    PubMed Central

    Levesque, Marshall J.; Raj, Arjun

    2013-01-01

    Here we report iceFISH, a multiplex imaging method for measuring gene expression and chromosome structure simultaneously on single chromosomes. We demonstrate that chromosomal translocations can alter transcription chromosome-wide, finding substantial differences in transcriptional frequency between genes located on a translocated chromosome in comparison to the normal chromosome in the same cell. Examination of correlations between genes on a single chromosome revealed a cis chromosome-level transcriptional interaction spanning 14.3 megabases. PMID:23416756

  17. Oncogene regulation. An oncogenic super-enhancer formed through somatic mutation of a noncoding intergenic element.

    PubMed

    Mansour, Marc R; Abraham, Brian J; Anders, Lars; Berezovskaya, Alla; Gutierrez, Alejandro; Durbin, Adam D; Etchin, Julia; Lawton, Lee; Sallan, Stephen E; Silverman, Lewis B; Loh, Mignon L; Hunger, Stephen P; Sanda, Takaomi; Young, Richard A; Look, A Thomas

    2014-12-12

    In certain human cancers, the expression of critical oncogenes is driven from large regulatory elements, called super-enhancers, that recruit much of the cell's transcriptional apparatus and are defined by extensive acetylation of histone H3 lysine 27 (H3K27ac). In a subset of T-cell acute lymphoblastic leukemia (T-ALL) cases, we found that heterozygous somatic mutations are acquired that introduce binding motifs for the MYB transcription factor in a precise noncoding site, which creates a super-enhancer upstream of the TAL1 oncogene. MYB binds to this new site and recruits its H3K27 acetylase-binding partner CBP, as well as core components of a major leukemogenic transcriptional complex that contains RUNX1, GATA-3, and TAL1 itself. Additionally, most endogenous super-enhancers found in T-ALL cells are occupied by MYB and CBP, which suggests a general role for MYB in super-enhancer initiation. Thus, this study identifies a genetic mechanism responsible for the generation of oncogenic super-enhancers in malignant cells. PMID:25394790

  18. Cell-by-Cell Dissection of Gene Expression and Chromosomal Interactions Reveals Consequences of Nuclear Reorganization

    PubMed Central

    2005-01-01

    The functional consequences of long-range nuclear reorganization were studied in a cell-by-cell analysis of gene expression and long-range chromosomal interactions in the Drosophila eye and eye imaginal disk. Position-effect variegation was used to stochastically perturb gene expression and probe nuclear reorganization. Variegating genes on rearrangements of Chromosomes X, 2, and 3 were probed for long-range interactions with heterochromatin. Studies were conducted only in tissues known to express the variegating genes. Nuclear structure was revealed by fluorescence in situ hybridization with probes to the variegating gene and heterochromatin. Gene expression was determined alternately by immunofluorescence against specific proteins and by eye pigment autofluorescence. This allowed cell-by-cell comparisons of nuclear architecture between cells in which the variegating gene was either expressed or silenced. Very strong correlations between heterochromatic association and silencing were found. Expressing cells showed a broad distribution of distances between variegating genes and their own centromeric heterochromatin, while silenced cells showed a very tight distribution centered around very short distances, consistent with interaction between the silenced genes and heterochromatin. Spatial and temporal analysis of interactions with heterochromatin indicated that variegating genes primarily associate with heterochromatin in cells that have exited the cell cycle. Differentiation was not a requirement for association, and no differences in association were observed between cell types. Thus, long-range interactions between distal chromosome regions and their own heterochromatin have functional consequences for the organism. PMID:15737020

  19. Cell Ablation Reveals That Expression from the Phaseolin Promoter Is Confined to Embryogenesis and Microsporogenesis.

    PubMed Central

    Van Der Geest, AHM.; Frisch, D. A.; Kemp, J. D.; Hall, T. C.

    1995-01-01

    Most previous studies of the [beta]-phaseolin (phas) gene, which encodes the major storage protein in bean (Phaseolus vulgaris L.), have shown its expression to be rigorously confined to the developing seed, both in bean and transgenic tobacco (Nicotiana tabacum L. cv Xanthi) plants. To confirm unequivocally the lack of phas expression in vegetative tissues, we placed the diphtheria toxin A-chain (DT-A) coding region under the control of [beta]-phaseolin promoter sequences. Tobacco plants transgenic for phas/DT-A were phenotypically normal until flowering, when they produced anthers that were externally normal but contained no viable pollen. Microscopic examination of immature anthers revealed a normal tapetum, but the pollen mother cells did not undergo meiosis and subsequently degenerated, resulting in male-sterile plants. This demonstration of phas expression during microsporogenesis was corroborated by the expression of [beta]-glucuronidase in pollen of plants transformed with comparable phas/uidA constructs. Although these findings suggested that similarities in phas expression may exist between seed and pollen maturation, no phas activity could be detected in bean pollen. After fertilization of the DT-A-transformed plants with pollen from wild-type tobacco, 50% of the resulting embryos aborted at the heart stage, defining this as the earliest time for phas expression during embryogenesis. PMID:12228659

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

    PubMed

    Tamai, Y; Taketo, M; Nozaki, M; Seldin, M F

    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. PMID:7601474

  1. 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.

  2. IL-33 Facilitates Oncogene Induced Cholangiocarcinoma in Mice by an IL-6 Sensitive Mechanism

    PubMed Central

    Yamada, Daisaku; Rizvi, Sumera; Razumilava, Nataliya; Bronk, Steven F.; Davila, Jaime I.; Champion, Mia D.; Borad, Mitesh J.; Bezerra, Jorge A.; Chen, Xin; Gores, Gregory J.

    2015-01-01

    Cholangiocarcinoma (CCA) is a lethal hepatobiliary neoplasm originating from the biliary apparatus. In humans, CCA risk factors include hepatobiliary inflammation and fibrosis. The recently identified IL-1 family member, IL-33, has been shown to be a biliary mitogen which also promotes liver inflammation and fibrosis. Our aim was to generate a mouse model of CCA mimicking the human disease. Ectopic oncogene expression in the biliary tract was accomplished by the Sleeping Beauty transposon transfection system with transduction of constitutively active AKT (myr-AKT) and Yes-associated protein (YAP). Intrabiliary instillation of the transposon-transposase complex was coupled with lobar bile duct ligation in CL57BL/6 mice, followed by administration of IL-33 for three consecutive days. Tumors developed in 72% of the male mice receiving both oncogenes plus IL-33 by 10 weeks, but in only 20% of the male mice transduced with the oncogenes alone. Tumors expressed SOX9 and pancytokeratin (PanCK) [features of cholangiocarcinoma] but were negative for HepPar1 [a marker of hepatocellular carcinoma (HCC)]. RNA profiling revealed substantive overlap with human CCA specimens. Not only did IL-33 induce IL-6 expression by human cholangiocytes, but IL-33 likely facilitated tumor development in vivo by an IL-6 sensitive process, as tumor development was significantly attenuated in Il-6 -/- male animals. Furthermore, tumor formation occurred at a similar rate when IL-6 was substituted for IL-33 in this model. In conclusion, the transposase-mediated transduction of constitutively active AKT and YAP in the biliary epithelium coupled with lobar obstruction and IL-33 administration results in the development of CCA with morphological and biochemical features of the human disease. This model highlights the role of inflammatory cytokines in CCA oncogenesis. PMID:25580681

  3. Global analysis of gene expression in pulmonary fibrosis reveals distinct programs regulating lung inflammation and fibrosis

    NASA Astrophysics Data System (ADS)

    Kaminski, Naftali; Allard, John D.; Pittet, Jean F.; Zuo, Fengrong; Griffiths, Mark J. D.; Morris, David; Huang, Xiaozhu; Sheppard, Dean; Heller, Renu A.

    2000-02-01

    The molecular mechanisms of pulmonary fibrosis are poorly understood. We have used oligonucleotide arrays to analyze the gene expression programs that underlie pulmonary fibrosis in response to bleomycin, a drug that causes lung inflammation and fibrosis, in two strains of susceptible mice (129 and C57BL/6). We then compared the gene expression patterns in these mice with 129 mice carrying a null mutation in the epithelial-restricted integrin 6 subunit (6/-), which develop inflammation but are protected from pulmonary fibrosis. Cluster analysis identified two distinct groups of genes involved in the inflammatory and fibrotic responses. Analysis of gene expression at multiple time points after bleomycin administration revealed sequential induction of subsets of genes that characterize each response. The availability of this comprehensive data set should accelerate the development of more effective strategies for intervention at the various stages in the development of fibrotic diseases of the lungs and other organs.

  4. Analysis of Synaptic Gene Expression in the Neocortex of Primates Reveals Evolutionary Changes in Glutamatergic Neurotransmission

    PubMed Central

    Muntané, Gerard; Horvath, Julie E.; Hof, Patrick R.; Ely, John J.; Hopkins, William D.; Raghanti, Mary Ann; Lewandowski, Albert H.; Wray, Gregory A.; Sherwood, Chet C.

    2015-01-01

    Increased relative brain size characterizes the evolution of primates, suggesting that enhanced cognition plays an important part in the behavioral adaptations of this mammalian order. In addition to changes in brain anatomy, cognition can also be regulated by molecular changes that alter synaptic function, but little is known about modifications of synapses in primate brain evolution. The aim of the current study was to investigate the expression patterns and evolution of 20 synaptic genes from the prefrontal cortex of 12 primate species. The genes investigated included glutamate receptors, scaffolding proteins, synaptic vesicle components, as well as factors involved in synaptic vesicle release and structural components of the nervous system. Our analyses revealed that there have been significant changes during primate brain evolution in the components of the glutamatergic signaling pathway in terms of gene expression, protein expression, and promoter sequence changes. These results could entail functional modifications in the regulation of specific genes related to processes underlying learning and memory. PMID:24408959

  5. What does children's spatial language reveal about spatial concepts? Evidence from the use of containment expressions.

    PubMed

    Johanson, Megan; Papafragou, Anna

    2014-06-01

    Children's overextensions of spatial language are often taken to reveal spatial biases. However, it is unclear whether extension patterns should be attributed to children's overly general spatial concepts or to a narrower notion of conceptual similarity allowing metaphor-like extensions. We describe a previously unnoticed extension of spatial expressions and use a novel method to determine its origins. English- and Greek-speaking 4- and 5-year-olds used containment expressions (e.g., English into, Greek mesa) for events where an object moved into another object but extended such expressions to events where the object moved behind or under another object. The pattern emerged in adult speakers of both languages and also in speakers of 10 additional languages. We conclude that learners do not have an overly general concept of Containment. Nevertheless, children (and adults) perceive similarities across Containment and other types of spatial scenes, even when these similarities are obscured by the conventional forms of the language. PMID:24641514

  6. 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

  7. The FBI1/Akirin2 Target Gene, BCAM, Acts as a Suppressive Oncogene

    PubMed Central

    Akiyama, Hirotada; Iwahana, Yoshimasa; Suda, Mikiya; Yoshimura, Atsunori; Kogai, Hiroyuki; Nagashima, Ai; Ohtsuka, Hiroko; Komiya, Yuko; Tashiro, Fumio

    2013-01-01

    Basal cell adhesion molecule (BCAM), known to be a splicing variant of Lutheran glycoprotein (LU), is an immunoglobulin superfamily membrane protein that acts as a laminin α5 receptor. The high affinity of BCAM/LU for laminin α5 is thought to contribute to the pathogenesis of sickle red blood cells and to various developmental processes. However, the function of BCAM in carcinogenesis is poorly understood. Based on microarray expression analysis, we found that BCAM was one of the target genes of the oncogenic 14-3-3β-FBI1/Akirin2 complex, which acts as a transcriptional repressor and suppresses MAPK phosphatase-1 gene expression. To elucidate the detailed function of BCAM in malignant tumors, we established BCAM-expressing hepatoma K2 cells. These cells lost the malignant characteristics of parental cells, such as anchorage-independent growth, migration, invasion, and tumorigenicity. Moreover, luciferase reporter assays and chromatin immunoprecipitation analysis revealed that the 14-3-3β-FBI1/Akirin2 complex bound to the BCAM promoter and repressed transcription. Thus, these data indicate that BCAM is a suppressive oncoprotein, and that FBI1/Akirin2 is involved in tumorigenicity and metastasis of hepatoma through the downregulation of suppressive oncogenes. PMID:24223164

  8. The FBI1/Akirin2 target gene, BCAM, acts as a suppressive oncogene.

    PubMed

    Akiyama, Hirotada; Iwahana, Yoshimasa; Suda, Mikiya; Yoshimura, Atsunori; Kogai, Hiroyuki; Nagashima, Ai; Ohtsuka, Hiroko; Komiya, Yuko; Tashiro, Fumio

    2013-01-01

    Basal cell adhesion molecule (BCAM), known to be a splicing variant of Lutheran glycoprotein (LU), is an immunoglobulin superfamily membrane protein that acts as a laminin α5 receptor. The high affinity of BCAM/LU for laminin α5 is thought to contribute to the pathogenesis of sickle red blood cells and to various developmental processes. However, the function of BCAM in carcinogenesis is poorly understood. Based on microarray expression analysis, we found that BCAM was one of the target genes of the oncogenic 14-3-3β-FBI1/Akirin2 complex, which acts as a transcriptional repressor and suppresses MAPK phosphatase-1 gene expression. To elucidate the detailed function of BCAM in malignant tumors, we established BCAM-expressing hepatoma K2 cells. These cells lost the malignant characteristics of parental cells, such as anchorage-independent growth, migration, invasion, and tumorigenicity. Moreover, luciferase reporter assays and chromatin immunoprecipitation analysis revealed that the 14-3-3β-FBI1/Akirin2 complex bound to the BCAM promoter and repressed transcription. Thus, these data indicate that BCAM is a suppressive oncoprotein, and that FBI1/Akirin2 is involved in tumorigenicity and metastasis of hepatoma through the downregulation of suppressive oncogenes. PMID:24223164

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

    PubMed

    Urbinati, Giorgia; Ali, Hafiz Muhammad; Rousseau, Quentin; Chapuis, Hubert; Desmaële, Didier; Couvreur, Patrick; Massaad-Massade, Liliane

    2015-01-01

    TMPRSS2-ERG junction oncogene is present in more than 50% of patients with prostate cancer and its expression is frequently associated with poor prognosis. Our aim is to achieve gene knockdown by siRNA TMPRSS2-ERG and then to assess the biological consequences of this inhibition. First, we designed siRNAs against the two TMPRSS2-ERG fusion variants (III and IV), most frequently identified in patients' biopsies. Two of the five siRNAs tested were found to efficiently inhibit mRNA of both TMPRSS2-ERG variants and to decrease ERG protein expression. Microarray analysis further confirmed ERG inhibition by both siRNAs TMPRSS2-ERG and revealed one common down-regulated gene, ADRA2A, involved in cell proliferation and migration. The siRNA against TMPRSS2-ERG fusion variant IV showed the highest anti-proliferative effects: Significantly decreased cell viability, increased cleaved caspase-3 and inhibited a cluster of anti-apoptotic proteins. To propose a concrete therapeutic approach, siRNA TMPRSS2-ERG IV was conjugated to squalene, which can self-organize as nanoparticles in water. The nanoparticles of siRNA TMPRSS2-ERG-squalene injected intravenously in SCID mice reduced growth of VCaP xenografted tumours, inhibited oncoprotein expression and partially restored differentiation (decrease in Ki67). In conclusion, this study offers a new prospect of treatment for prostate cancer based on siRNA-squalene nanoparticles targeting TMPRSS2-ERG junction oncogene. PMID:25933120

  10. Signature gene expression reveals novel clues to the molecular mechanisms of dimorphic transition in Penicillium marneffei.

    PubMed

    Yang, Ence; Chow, Wang-Ngai; Wang, Gang; Woo, Patrick C Y; Lau, Susanna K P; Yuen, Kwok-Yung; Lin, Xiaorong; Cai, James J

    2014-10-01

    Systemic dimorphic fungi cause more than one million new infections each year, ranking them among the significant public health challenges currently encountered. Penicillium marneffei is a systemic dimorphic fungus endemic to Southeast Asia. The temperature-dependent dimorphic phase transition between mycelium and yeast is considered crucial for the pathogenicity and transmission of P. marneffei, but the underlying mechanisms are still poorly understood. Here, we re-sequenced P. marneffei strain PM1 using multiple sequencing platforms and assembled the genome using hybrid genome assembly. We determined gene expression levels using RNA sequencing at the mycelial and yeast phases of P. marneffei, as well as during phase transition. We classified 2,718 genes with variable expression across conditions into 14 distinct groups, each marked by a signature expression pattern implicated at a certain stage in the dimorphic life cycle. Genes with the same expression patterns tend to be clustered together on the genome, suggesting orchestrated regulations of the transcriptional activities of neighboring genes. Using qRT-PCR, we validated expression levels of all genes in one of clusters highly expressed during the yeast-to-mycelium transition. These included madsA, a gene encoding MADS-box transcription factor whose gene family is exclusively expanded in P. marneffei. Over-expression of madsA drove P. marneffei to undergo mycelial growth at 37°C, a condition that restricts the wild-type in the yeast phase. Furthermore, analyses of signature expression patterns suggested diverse roles of secreted proteins at different developmental stages and the potential importance of non-coding RNAs in mycelium-to-yeast transition. We also showed that RNA structural transition in response to temperature changes may be related to the control of thermal dimorphism. Together, our findings have revealed multiple molecular mechanisms that may underlie the dimorphic transition in P. marneffei