Project description:Increased expression of GLI1 is associated with poor prognosis for some breast cancer subtypes. A conditional transgenic GLI1 expressing mouse model, with or without heterozygous deletion of Trp53, was used to generate and study GLI1 induced mammary gland tumours. Tumour tissue was serially orthotopically transplanted for at least 10 generations in NSG mice.
Project description:GLI1 is a transcription factor correlated to decreased survival in several cancers. We have identified SMARCA2 as a co-regulator that enhances GLI1-mediated transcriptional activity and functions through the C-terminal transcriptional activation domain of GLI1. Central domains including the ATPase motif of SMARCA2 physically interact with GLI1. Evaluation of DNA density indicates GLI1, like SMARCA2, can increase the DNA accessibility with a preference for sites distal to gene transcription start sites and outside the promoter regions (i.e. enhancers). The putative enhancers where accessibility is decreased by the knock down of GLI1 and SMARCA2 are located cis to genes, such as HHIP, that are regulated by GLI1 and implicated in cancer functions. At the putative enhancer for HHIP, the localization of SMARCA2 is at least partially dependent on GLI1’s presence. Understanding this transcriptional regulation by GLI1 and SMARCA2 through altering chromatin accessibility at enhances can provide additional therapeutic targets for cancers dependent on GLI1.
Project description:GLI1 is a transcription factor correlated to decreased survival in several cancers. We have identified SMARCA2 as a co-regulator that enhances GLI1-mediated transcriptional activity and functions through the C-terminal transcriptional activation domain of GLI1. Central domains including the ATPase motif of SMARCA2 physically interact with GLI1. Evaluation of DNA density indicates GLI1, like SMARCA2, can increase the DNA accessibility with a preference for sites distal to gene transcription start sites and outside the promoter regions (i.e. enhancers). The putative enhancers where accessibility is decreased by the knock down of GLI1 and SMARCA2 are located cis to genes, such as HHIP, that are regulated by GLI1 and implicated in cancer functions. At the putative enhancer for HHIP, the localization of SMARCA2 is at least partially dependent on GLI1’s presence. Understanding this transcriptional regulation by GLI1 and SMARCA2 through altering chromatin accessibility at enhances can provide additional therapeutic targets for cancers dependent on GLI1.
Project description:Changes in the GLI1 cistrome following ionizing radiation were investigated using ChIP-Seq in SUM1315 triple-negative breast cancer cells.
Project description:We sought to determine the effects of over-expression of Gli1 on gene expression in C2C12 myotube cultures. C2C12 myoblasts were induced to differentiate for 4 days. At that time, when >80% of nuclei were incorporated into multi-nucleated syncitial myotubes, we infected the cultures with recombinant adenovirus expressing GFP alone or GFP and a full length human Gli1. Media was changed 12 hours later. Cultures were lysed 60 hours after the initial infection. Gli1 over-expression induces de-differentiation of myotubes and proliferation of myoblasts. Results provide insight into the molecular basis of SHH signaling on skeletal muscle cells.
Project description:In the vertebrate neural tube, regional Sonic hedgehog (Shh) signaling invokes a time- and concentration-dependent induction of six different cell populations mediated through Gli transcriptional regulators. Elsewhere in the embryo, Shh/Gli responses invoke different tissue appropriate regulatory programs. To elucidate Shh/Gli regulation of neural fate sepcification, we performed Gli1 ChIP-Seq analysis. We further analyzed two transcription factors whose motifs were enriched in Gli1 ChIP data (Sox2 and Foxa2). Two active histone marks (H3K4me2 and H3K27ac) were additionally analyzed to study activity status of Shh-responsive cis-elements. Active enhancer histone marks and transcription factor binding patterns were obtained from neuralized emrbyoid bodies. Biological replicates were performed for Gli1 and mock FLAG chips. Histone profiling for enhancer marks were taken from time course experiment performed in parallel.
Project description:We sought to determine the effects of over-expression of Gli1 on gene expression in C2C12 myotube cultures. C2C12 myoblasts were induced to differentiate for 4 days. At that time, when >80% of nuclei were incorporated into multi-nucleated syncitial myotubes, we infected the cultures with recombinant adenovirus expressing GFP alone or GFP and a full length human Gli1. Media was changed 12 hours later. Cultures were lysed 60 hours after the initial infection. Gli1 over-expression induces de-differentiation of myotubes and proliferation of myoblasts.
Project description:The morphogen Indian Hedgehog is expressed by the intestinal epithelium and signals in paracrine manner to fibroblasts by activating trascription factor Gli1. ZsGreen is used to track Gli1+ cells. To describe different fibroblast subpopulations we used gp38 as a general marker and Sca1 as a marker expressed in some of gp38+ cells.
Project description:Previous studies demonstrated that hererozygous missense mutations in IHH could lead to a decreasing IHH signaling efficacy and cause brachydactyly type A1 (BDA1). For revealing difference of Gli1-mediated downstream regulatory effects between wild type IHH signaling and E95K mutant IHH signaling, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to be targets of Gli1 cis-regulation.