Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Prostate cancer is one of the most common malignancies and the second leading cause of death from cancer in men. The molecular mechanisms driving prostate carcinogenesis are complex; with several lines of evidence suggesting that the re-expression of conserved developmental programs play a key role. Through conditional gene targeting and organ grafting, we describe conserved roles for the transcription factor Sox9 in the initiation of both prostate organogenesis and prostate carcinogenesis in murine models. Abrogation of Sox9 expression prior to the initiation of androgen signaling blocks the initiation of prostate development. Similarly, Sox9 deletion in two genetic models of prostate cancer (TRAMP and Hi-Myc) blocks cancer initiation. Expression profiling of Sox9-null prostate epithelial cells reveals that the role of Sox9 in the initiation of prostate development may relate to its regulation of multiple cytokeratins and/or calcium-related proteins. Due to its essential role in cancer initiation, manipulation of Sox9 targets in at-risk men may prove useful in the chemoprevention of prostate cancer. Sox9 differential gene expression in prostaspheres derived from the urogenital sinus epithelium was assessed by tow-colors direct comparisons of labeled moieties. Hybridizations were performed on the Agilent (Santa Clara, CA) Whole Mouse Genome DNA microarray (mgug4122a). Sox9 targets were assessed in murine prostate epithelial cells with targeted deletion.
Project description:Progastrin is a pro-hormone that, in physiological conditions, is maturated in gastrin in G cells of the stomach. The role of the gastrin is to stimulate the secretion of gastric acids during digestion. It is also important for the regulation of cell growth of the gastric mucosal.
In a healthy person, progastrin is not detectable in the peripheral blood. However, progastrin is abnormally released in the blood of patients with different cancers (colorectal, gastric, ovarian, breast, cervix uterus, melanoma...) The gene GAST coding for progastrin is a direct target gene of the WNT/ß-catenin oncogenic pathway. The activation of this oncogenic pathway is an early event in cancer development.
Chronic activation of the WNT/ß-catenin oncogenic pathway occurs in almost all human solid tumors and is a central mechanism in cancer biology that induces cellular proliferation, blocking of differentiation leading to primary tumor growth and metastasis formation.
Progastrin measured in the peripheral blood of patients on treatments, could be a new powerful marker for diagnosis and prognosis at different stages.
Project description:Mammalian intestinal epithelium stem cells (IESCs) and their daughter cells require the participation of DNA methylation and the transcription factor Sox9 for proliferation and differentiation. Combining methylated DNA immunoprecipitation with microarray hybridization, we demonstrate that hypomethylation in promoter participates in the aberrant formation of crypts in diabetic db/db mice through ectopic Wnt signaling. More importantly, increased expression of Sox9 is accompanied by the loss of methylation in its promoter in IESCs. Using ChIP-seq analysis for Sox9 in IESCs, we demonstrate that Sox9 primarily targets the enhancers of Wnt signaling pathway-related genes. Sox9 is not only predominately acting as a transcriptional activator at proximal enhancer but also as a potential transcriptional inhibitor at distant enhancer. Lack of Sox9 transcriptional activation in specific repressors of Wnt signaling pathway results in loss of intrinsic inhibitory action and ultimately produces over-activation of this pathway in diabetes mellitus.
Project description:Mammalian intestinal epithelium stem cells (IESCs) and their daughter cells require the participation of DNA methylation and the transcription factor Sox9 for proliferation and differentiation. Combining methylated DNA immunoprecipitation with microarray hybridization, we demonstrate that hypomethylation in promoter participates in the aberrant formation of crypts in diabetic db/db mice through ectopic Wnt signaling. More importantly, increased expression of Sox9 is accompanied by the loss of methylation in its promoter in IESCs. Using ChIP-seq analysis for Sox9 in IESCs, we demonstrate that Sox9 primarily targets the enhancers of Wnt signaling pathway-related genes. Sox9 is not only predominately acting as a transcriptional activator at proximal enhancer but also as a potential transcriptional inhibitor at distant enhancer. Lack of Sox9 transcriptional activation in specific repressors of Wnt signaling pathway results in loss of intrinsic inhibitory action and ultimately produces over-activation of this pathway in diabetes mellitus.