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C-myc Gene (c-myc + gene)
Selected AbstractsChromosome-mediated alterations of the MYC gene in human cancerJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 2 2002N. C. Popescu Abstract The step-wise accumulation of genetic and epigenetic alterations in cancer development includes chromosome rearrangements and viral integration-mediated genetic alterations that frequently involve proto-oncogenes. Protooncogenes deregulation lead to unlimited, self-sufficient cell growth and ultimately generates invasive and destructive tumors. C-MYC gene, the cellular homologue of the avian myelocitic leukemia virus, is implicated in a large number of human solid tumors, leukemias and lymphomas as well as in a variety of animal neoplasias. Deregulated MYC expression is a common denominator in cancer. Chromosomal rearrangements and integration of oncogenic viruses frequently target MYC locus, causing structural or functional alterations of the gene. In this article, we illustrate how genomic rearrangements and viruses integration affect MYC locus in certain human lymphomas and solid tumors. [source] The PVT-1 oncogene is a Myc protein target that is overexpressed in transformed cells,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2007Letizia Carramusa The human PVT-1 gene is located on chromosome 8 telomeric to the c-Myc gene and it is frequently involved in the translocations occurring in variant Burkitt's lymphomas and murine plasmacytomas. It has been proposed that PVT-1 regulates c-Myc gene transcription over a long distance. To get new insights into the functional relationships between the two genes, we have investigated PVT-1 and c-Myc expression in normal human tissues and in transformed cells. Our findings indicate that PVT-1 expression is restricted to a relative low number of normal tissues compared to the wide distribution of c-Myc mRNA, whereas the gene is highly expressed in many transformed cell types including neuroblastoma cells that do not express c-Myc. Reporter gene assays were used to dissect the PVT-1 promoter and to identify the region responsible for the elevated expression observed in transformed cells. This region contains two putative binding sites for Myc proteins. The results of transfection experiments in RAT1-MycER cells and chromatin immunoprecipitation (ChIP) assays in proliferating and differentiated neuroblastoma cells indicate that PVT-1 is a downstream target of Myc proteins. J. Cell. Physiol. 213: 511,518, 2007. © 2007 Wiley-Liss, Inc. [source] Enhancement of gene expression by a peptide p(CHWPR) produced by Bifidobacterium lactis BB-12MICROBIOLOGY AND IMMUNOLOGY, Issue 3 2008Takashi Mitsuma ABSTRACT Recently, probiotics, including Bifidobacterium, Lactobacillus, and Enterococcus, among other organisms, have been clinically applied for their enhancing effects on defense mechanisms. It is reported that gene expression in somatic cells can be activated by autoinducers, which are hormone-like molecules produced in a microbial QS system. In the present study, based on a hypothesis that a low-molecular substance related to the QS system is involved in the probiotics effects of Bifidobacterium, we intended to extract the low-molecular substance. As a result, we successfully isolated the peptide p(CHWPR), which was composed of five amino acids including Cys, His, Trp, Pro, and Arg, and found that the peptide was produced in the stationary phase of bacterial growth and that it could enhance the gene expression of oxalyl-CoA decarboxylase (Oxc). p(CHWPR) enhanced the gene expression of c-myc and interleukin (IL)-6 in an established cell line, HL-60. We demonstrated that p(CHWPR) penetrates the cell membrane and binds specifically to ROR,, which is a cytosolic nuclear receptor. This suggests that ROR, bound to p(CHWPR) would bind to promoter regions of the c-myc gene. Furthermore, we found that p(CHWPR) also bound to a transcriptional avtivation subunit, CRSP70; this suggests that p(CHWPR), ROR,, and CRSP70 in combination enhance transcription activity. [source] Pediatric ALK+ anaplastic large cell lymphoma with t(3;8)(q26.2;q24) translocation and c-myc rearrangement terminating in a leukemic phaseAMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2007Sara Monaco Abstract Pediatric ALK-positive anaplastic large cell lymphoma (ALK+ ALCL) is usually associated with a favorable prognosis. ALK+ ALCL associated with a leukemic phase is uncommon, but has been associated with an aggressive clinical course and unfavorable prognosis. Overexpression of c-myc has been shown to be a consistent finding in ALK+, but not ALK-negative ALCL (ALK, ALCL), and the c-myc gene is considered a downstream target of deregulated ALK signaling. We describe a pediatric ALK+ ALCL with a leukemic phase at relapse. Similar to other rare cases described in the literature, it followed an aggressive clinical course despite multiple regimens of chemotherapy and bone marrow transplantation. Lymphoma cells showed aberrant ALK expression and c-myc overexpression. In addition to the characteristic t(2;5)(p23;q35) translocation, a t(3;8)(q26.2;q24) translocation was also present, and c-myc gene rearrangement was confirmed by FISH analysis. The findings in this case demonstrate the association of peripheral blood leukemic involvement and aggressive clinical course, and suggest that other factors, such as c-myc rearrangement, may be responsible for the aggressive clinical behavior in ALK+ ALCL. Am. J. Hematol., 2006. © 2006 Wiley-Liss, Inc. [source] Targeted Gene Expression Analysis in Hemimegalencephaly: Activation of ,-Catenin SignalingBRAIN PATHOLOGY, Issue 3 2005Jia Yu MD Hemimegalencephaly (HMEG) is a developmental brain malformation characterized by unilateral hemispheric enlargement, cytoarchitectural abnormalities, and an association with epilepsy. To define the developmental pathogenesis of HMEG, the expression of 200 cell signaling, growth, angiogenic, and transcription factor genes was assayed in HMEG samples (n = 8) with targeted cDNA arrays. Differential expression of 31 mRNAs across the 4 gene families was identified in HMEG compared with control cortex. Increases in growth and transcription factor genes included JNK-1, cyclic AMP response element binding protein (CREB), and tuberin mRNAs and decreases included insulin-like growth factor-1 (IGF-1), transforming growth factor ,-3 (TGF-,3), and NFkB mRNAs. Increased expression of cyclin D1, c-myc, and WISP-1 mRNAs in HMEG suggested activation of the Wnt-1/,-catenin cascade. Western analysis demonstrated increased levels of non-phosphorylated ,-catenin, which transcriptionally activates cyclin D1 and c-myc genes, but reduced levels of Ser33/Ser37/Thr41 phospho-,-catenin, which is essential for ,-catenin-inactivation, in HMEG. Altered expression of 31 mRNAs from 4 gene families in human HMEG may lead to aberrant cell growth and hemispheric enlargement during brain development. Enhanced cyclin D1 and c-myc transcription likely reflects increased transcriptionally active ,-catenin due to decreased Ser33/Ser37/Thr41 phospho-,-catenin and suggests activation of the Wnt-1/,-catenin cascade in HMEG. [source] | |||||||||||||