Project description:CIC binding was determined in KP murine lung cancer cells in untreated cells as well as after treatment with trametinib to enhance CIC binding to DNA. As a negative control, CIC binding was also determined in KPCic cells that express a non-functional CIC incapable of DNA binding.
Project description:The transcriptional repressor Capicua (CIC) is negatively regulated by KRAS/MAPK signaling. To characterize the impact of CIC loss on KrasG12V/Trp53-KO-driven lung adenocarcinomas in mice, the transcriptome of tumors from Kras (+/LSLG12V); Trp53 (lox/lox) [KP] and Kras (+/LSLG12V); Trp53 (lox/lox); Cic (lox/lox) [KPCic] mice are compared.
Project description:Purpose: Cic is a transcription factor regulating intestinal stem cell (ISC) proliferation as downstream effector of EGFR signaling pathway. ISC-specific mRNA expression profiling and DNA binding mapping using DamID were performed to identify potential target of Cic. Methods: Total RNA was isolated from GFP+ FACS sorted cells and sent for sequencing after amplification. Conclusions: We identified potential target genes of Cic, which is differetially expressed in Cic depleted ISCs and also associated Cic binding peaks.
Project description:YAP depletion in the KP tumor system results in smaller tumors and delayed tumor latency. We used microarrays to investigate changes in global gene expression due to YAP1 loss in KP tumors
Project description:We report the gene expression profile of three murine lung cancer cell lines, and also comparing the similarities of gene expression between KP mice-derived tumor cells and Regrogrammed somatic cells-derived tumor cells.
Project description:Type I low-grade gliomas (LGGs), characterized by 1p/19q co-deletions and IDH1/2 mutations, show superior overall survival compared to other gliomas. Approximately 70% of cases harbour mutations in the Capicua (CIC) gene, whose product is a transcriptional repressor whose transcriptional network has yet to be extensively studied in human cells. To address this, we developed CIC knockout cell lines and used transcriptome analyses to study the consequences of CIC loss. Results were further compared to data for Type I LGGs and stomach adenocarcinomas from The Cancer Genome Atlas (TCGA). We find that CIC appears to regulate the expression of genes involved in cell-cell adhesion and nervous system development. CIC deficiency is also found to be associated with a MEK activation transcriptional signature and to act as an effector of MEK signalling. Loss of CIC may thus present a novel mechanism for the dysregulation of this and other oncogenic pathways.
Project description:The receptor tyrosine kinase (RTK)/Extracellular Signal-Regulated Kinase (ERK) signaling pathway controls cell proliferation, differentiation, and survival. How ERK activation is relayed to its phosphorylation targets is not well understood. The transcriptional repressor Capicua (Cic) has emerged as a key target for ERK-mediated downregulation in Drosophila and mammals, and mutations in human CIC result in cancer and neurological diseases. Phosphorylation by ERK is critical for Cic downregulation, but the identities of phosphosites in Drosophila Cic are unknown. Here, we identify sites of phosphorylation in Cic that are directly targeted by ERK and validate their developmental functions in vivo using mutant Cic variants. Cic phosphosites are distributed throughout the length of the protein, and a group of centrally located sites appears to have a primary role in Cic downregulation. Cic mutated in 20 high-confidence sites behaves as a “super-repressor” in vivo that is largely insensitive to ERK-mediated downregulation, despite fully retaining the ability to bind to ERK. No single site is sufficient to turn off Cic activity; instead, we find that ERK must phosphorylate multiple sites in Cic simultaneously to achieve full downregulation. This multisite phosphorylation likely targets phosphodegrons that are recognized by ubiquitin ligases such as Ago/FBXW7 and contributes to Cic degradation. This study advances our understanding of the molecular mechanisms of signal interpretation downstream of the RTK/ERK signaling network.
Project description:CIC-DUX4-rearranged sarcoma (CDS) is a rare and aggressive soft tissue tumor that occurs most frequently in young adults. The key oncogenic driver of this disease is the expression of the CIC-DUX4 fusion protein as a result of chromosomal rearrangements. CIC-DUX4 displays chromatin binding properties, and is therefore believed to function as an aberrant transcription factor. However, the chromatin remodeling events induced by CIC-DUX4 are not well understood, limiting our ability to identify new mechanism-based therapeutic strategies for these patients. Here we generated a genome wide profile of CIC-DUX4 DNA occupancy and associated chromatin states in human CDS cell models and primary tumors. Combining chromatin profiling, proximity ligation assays, as well as genetic and pharmacological perturbations, we show that CIC-DUX4 operates as a potent transcriptional activator at its binding sites. This property is in contrast with the repressive function of the wild type CIC protein, and is mainly mediated through the direct interaction of CIC-DUX4 with the acetyltransferase p300. In keeping with this, we show p300 to be essential for CDS tumor cell proliferation, and its pharmacological inhibition to significantly impact tumor growth in vitro andin vivo. Taken together, our study elucidates the mechanisms underpinning CIC-DUX4-mediated transcriptional regulation and suggests a potential therapeutic approach for the clinical management of CDS patients.
Project description:CIC-DUX4-rearranged sarcoma (CDS) is a rare and aggressive soft tissue tumor that occurs most frequently in young adults. The key oncogenic driver of this disease is the expression of the CIC-DUX4 fusion protein as a result of chromosomal rearrangements. CIC-DUX4 displays chromatin binding properties, and is therefore believed to function as an aberrant transcription factor. However, the chromatin remodeling events induced by CIC-DUX4 are not well understood, limiting our ability to identify new mechanism-based therapeutic strategies for these patients. Here we generated a genome wide profile of CIC-DUX4 DNA occupancy and associated chromatin states in human CDS cell models and primary tumors. Combining chromatin profiling, proximity ligation assays, as well as genetic and pharmacological perturbations, we show that CIC-DUX4 operates as a potent transcriptional activator at its binding sites. This property is in contrast with the repressive function of the wild type CIC protein, and is mainly mediated through the direct interaction of CIC-DUX4 with the acetyltransferase p300. In keeping with this, we show p300 to be essential for CDS tumor cell proliferation, and its pharmacological inhibition to significantly impact tumor growth in vitro andin vivo. Taken together, our study elucidates the mechanisms underpinning CIC-DUX4-mediated transcriptional regulation and suggests a potential therapeutic approach for the clinical management of CDS patients.