Temporal expression profiling was utilized to define transcriptional regulatory pathways in vivo in a mouse muscle regeneration model. Potential downstream targets of MyoD were identified by temporal expression, promoter data base mining, and gel shift assays; Slug and calpain 6 were identified as novel MyoD targets. Slug, a member of the snail/slug family of zinc finger transcriptional repressors critical for mesoderm/ectoderm development, was further shown to be a downstream target by using promoter/reporter constructs and demonstration of defective muscle regeneration in Slug null mice.
Slug is a novel downstream target of MyoD. Temporal profiling in muscle regeneration.
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View SamplesSolid tumors are less oxygenated than normal tissues, and for this reason the cancer cells have developed several molecular mechanisms of adaptation to hypoxic environment. Moreover, his poor oxygenation is a major indicator of an adverse prognosis and leads resistance to standard anticancer treatment. Previous reports from this laboratory showed an involvement of Che-1/AATF (Che-1) in cancer cell survival under stress conditions, and on the basis of these observations, we hypothesized that Che-1 might have a role in the response of cancer cells to hypoxia. Methods: The human colon adenocarcinoma cell line HCT116 depleted or not for Che-1 by siRNA, was subjected to normoxic and hypoxic conditions to perform studies about the role of this protein in metabolic adaptation and cell proliferation. The expression of Che-1 under normoxia or hypoxia was detected using western blot assays; cell metabolism was assessed by NMR spectroscopy and functional assays. Further molecular studies were performed by RNA seq, qRT-PCR and ChIP analysis. Results: In this paper we report that Che-1 expression is required for the adaptation of the cells to hypoxia, playing and important role in metabolic modulation. Indeed, Che-1 depletion impacted on glycolysis by altering the expression of several genes involved in the response to hypoxia by modulating the levels of HIF-1alpha. Conclusions: These data demonstrate a novel player in the regulation of a HIF1alpha in response to hypoxia. We found that the transcriptional down-regulation of a members of E3 ubiquitin ligase family SIAH2 by Che-1, produces a failure in the degradation by the hydroxylase PHD3 with a decrease in HIF-1alpha levels during hypoxia. Overall design: The human colon adenocarcinoma cell line HCT116 depleted or not for Che-1 by siRNA was profiled for mRNA high-troughput sequencing (RNA-seq)
Che-1 sustains hypoxic response of colorectal cancer cells by affecting Hif-1α stabilization.
Cell line, Subject
View SamplesChe-1 is a RNA Polymerase II binding protein involved in the regulation of gene transcription. We have observed that Che-1 depletion induces apoptosis in several cancer cells expressing mutated forms of p53. We used microarrays to investigate classes of genes regulated by Che-1 in one of these cell lines.
Che-1 promotes tumor cell survival by sustaining mutant p53 transcription and inhibiting DNA damage response activation.
Specimen part, Cell line
View SamplesCancer tissue-like structures were developed by using established human tumor cell lines in perfusion-based bioreactor systems. In colorectal cancer (CRC) cell lines, perfusion allowed more homogeneous scaffold seeding than tri-dimensional (3D) static cultures and significantly (13.7 fold, p<0.0001) higher proliferation. Resulting tissues exhibited morphology and phenotypes similar to xenografts generated in immunodeficient mice. Whole transcriptome analysis of 2D, 3D static and 3D perfusion cultures revealed the highest correlation between xenografts and 3D perfusion cultures (r=0.985). Clinically relevant concentrations of 5-FU, used in neo- and adjuvant CRC treatment, had no effect on numbers of HT-29 CRC cells cultured in 3D perfusion or xenografts, as compared with a 55.8% reduction in 2D cultures. Treatment induced apoptosis in 2D cultures, but only “nucleolar stress” in perfused cells and xenografts, consistent with partial responsiveness. In 3D perfusion cultures BCL-2, TRAF1, and FLIP gene expression was marginally affected, as compared with significant down-regulation in 2D cell cultures. Accordingly, ABT-199 BCL-2 inhibitor, induced cytostatic effects in 3D perfusion but not in 2D cell cultures (p=0.003). Tumor cells from partially responsive (Dworak 2) patients undergoing neo-adjuvant treatment, typically (10/11) expressed BCL-2, as compared with 0/3 highly (Dworak 3-4) responsive and 4/15 fully resistant CRC (Dworak 0/1, p=0.03), closely matching 3D perfusion cultures data. These results indicate that 3D perfusion cultures efficiently mimic phenotypic and functional features observed in xenografts and clinical specimens. These models may be of critical translational relevance to address fundamental human tumor cell biology issues and to develop predictive pre-clinical tests of novel compounds. Overall design: Expression profiles of colorectal cancer cell lines cultured in 2D, 3D static, 3D perfusion or growing as xenografts were generated by deep sequencing, in triplicates, using Illumina HiSeq2000.
Bioreactor-engineered cancer tissue-like structures mimic phenotypes, gene expression profiles and drug resistance patterns observed "in vivo".
No sample metadata fields
View SamplesChe-1 is a RNA Polymerase II binding protein involved in the regulation of gene transcription. Che-1 emerges as an important adaptor that connects transcriptional regulation, cell-cycle progression, checkpoint control, and apoptosis.
Che-1-induced inhibition of mTOR pathway enables stress-induced autophagy.
Cell line, Treatment
View SamplesTo investigate the genes differentially induced by c-FLIP up-regulation by lentivirus infection in monocytes from healthy donors
Induction of immunosuppressive functions and NF-κB by FLIP in monocytes.
Disease
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