Project description:Cyclin D1 is an important cell cycle regulator but in cancer its overexpression also increases cellular migration mediated by p27KIP1 stabilization and RhoA inhibition. Recently, a common polymorphism at the exon 4-intron 4 boundary of the human cyclin D1 gene within a splice donor region was associated with an altered risk of developing cancer. Altered RNA splicing caused by this polymorphism gives rise to a variant cyclin D1 isoform termed cyclin D1b, which has the same N-terminus as the canonical cyclin D1a isoform but a distinct C-terminus. Analysis was performed of mouse cyclin D1 knockout 3T3 cells infected with splice variants of cyclin D1. 3T3 cells transduced with retroviral vectors expressing each cyclin D1 isoform were processed for expression analysis. Experiment Overall Design: Three Mouse Embryonic Fibroblasts cell lines obtained from littermate cyclin D1 knockout E14 embyos were serial passaged to obtain cyclin D1 knockout (D1KO) 3T3 cells. Each of the D1KO 3T3 cell lines were infected using the Murine Stem Cell Virus (MSCV) expressing splice variants of cyclin D1; cyclin D1a/ cyclin D1b or GFP control to give triplicate sample sets. 7 days post infection total RNA from each sample was extracted using Trizol and further purified using Qiagenâs RNeasy Kit. Preparation of biotinylated cRNA and hybridization to oligonucleotide arrays (Affymetrix mouse genome genechip 430 2.0) were performed in conjuction with Pestell lab and the Nucleic Acid Core Facility at Thomas Jefferson University. Mouse 430 2.0 genechip contains 39,000 transcripts. Gene chips were scanned and analyzed using Robust Multi-array Average (RMA) algorithm.
Project description:Cyclin D1 is an important cell cycle regulator but in cancer its overexpression also increases cellular migration mediated by p27KIP1 stabilization and RhoA inhibition. Recently, a common polymorphism at the exon 4-intron 4 boundary of the human cyclin D1 gene within a splice donor region was associated with an altered risk of developing cancer. Altered RNA splicing caused by this polymorphism gives rise to a variant cyclin D1 isoform termed cyclin D1b, which has the same N-terminus as the canonical cyclin D1a isoform but a distinct C-terminus. Analysis was performed of mouse cyclin D1 knockout 3T3 cells infected with splice variants of cyclin D1. 3T3 cells transduced with retroviral vectors expressing each cyclin D1 isoform were processed for expression analysis. Keywords: Cancer associated risk factor
Project description:Cyclin D1 belongs to the core cell cycle machinery1, and it is frequently overexpressed in human cancers2. The full repertoire of cyclin D1 functions in normal development and in cancer cells is currently unknown. To address this question, here we introduce a novel approach that allows one to determine the set of cyclin D1-interacting proteins (D1 “interactome”) and cyclin D1-bound genomic fragments (D1 “cistrome”) in essentially any mouse organ, at any point of development or at any stage of cancer progression. Using this approach, we detected several novel tissue-specific interactors of cyclin D1. A significant number of these partners represent proteins involved in transcription. We show, using genome-wide location analysis3, that cyclin D1 occupies promoters of a very large number of genes in the developing mouse, where it binds in close proximity to transcription start sites. Bioinformatics analyses of cyclin D1-bound genomic segments in the developing embryo revealed DNA recognition sequences for several transcription factors. By querying SAGE libraries4, promoter CpG content5 and gene expression profiles of cyclin D1-null organs, we demonstrate that cyclin D1 binds promoters of highly expressed genes, and that it functions to activate or to repress gene expression in vivo. Analyses of cyclin D1 transcriptional targets reveal that cyclin D1 contributes to cell proliferation by upregulating genes required for S-phase entry and progression. Hence, cyclin D1 plays a broad transcriptional regulatory function in vivo during normal mouse development.
Project description:Cyclin D1 belongs to the core cell cycle machinery1, and it is frequently overexpressed in human cancers2. The full repertoire of cyclin D1 functions in normal development and in cancer cells is currently unknown. To address this question, here we introduce a novel approach that allows one to determine the set of cyclin D1-interacting proteins (D1 “interactome”) and cyclin D1-bound genomic fragments (D1 “cistrome”) in essentially any mouse organ, at any point of development or at any stage of cancer progression. Using this approach, we detected several novel tissue-specific interactors of cyclin D1. A significant number of these partners represent proteins involved in transcription. We show, using genome-wide location analysis3, that cyclin D1 occupies promoters of a very large number of genes in the developing mouse, where it binds in close proximity to transcription start sites. Bioinformatics analyses of cyclin D1-bound genomic segments in the developing embryo revealed DNA recognition sequences for several transcription factors. By querying SAGE libraries4, promoter CpG content5 and gene expression profiles of cyclin D1-null organs, we demonstrate that cyclin D1 binds promoters of highly expressed genes, and that it functions to activate or to repress gene expression in vivo. Analyses of cyclin D1 transcriptional targets reveal that cyclin D1 contributes to cell proliferation by upregulating genes required for S-phase entry and progression. Hence, cyclin D1 plays a broad transcriptional regulatory function in vivo during normal mouse development.
Project description:We examined the transcriptional function of cyclin D1 in mouse development using two approaches. First, we queried association of cyclin D1 with the genome of E14.5 mouse embryos using ChIP-on-chip approach. We observed binding of cyclin D1 to several promoter regions. Second, we compared gene expression profiles between wild-type and cyclin D1-null retinas. We observed several transcripts with altered levels in cyclin D1-null organs. This SuperSeries is composed of the SubSeries listed below.