Project description:VHL loss is the most common genetic alteration event in ccRCC, but its effect on epigenetic landscape has not been elucidated previously. By performing histone modifications (H3K27ac, H3K4me1, H3K4me3) from ccRCC cell lines, we describe the genome-wide cis-regulatory landscapes of VHL-deficient ccRCC tumors. We show that ccRCCs exhibit a pervasive gain of enhancers around hypoxic and metabolic transcriptional targets.
Project description:VHL loss is the most common genetic alteration event in ccRCC, but its effect on epigenetic landscape has not been elucidated previously. By performing histone modifications (H3K27ac, H3K4me1, H3K4me3) from ccRCC cell lines, we describe the genome-wide cis-regulatory landscapes of VHL-deficient ccRCC tumors. We show that ccRCCs exhibit a pervasive gain of enhancers around hypoxic and metabolic transcriptional targets.
Project description:VHL loss is the most common genetic alteration event in ccRCC, but its effect on epigenetic landscape has not been elucidated previously. We describe the genome-wide cis-regulatory landscapes of VHL-deficient ccRCC tumors by comparing the epigenetic changes in terms of histone modifications (H3K27ac, H3K4me1, H3K4me3) with the transcriptomics profiles in 10 pairs of normal kidney and ccRCC tissues.
Project description:Clear cell renal cell carcinoma (ccRCC), the most common kidney cancer subtype, often features inactivation of the VHL tumor suppressor, creating therapeutic vulnerabilities. Although HIF2α inhibitors have shown promise, many VHL-deficient tumors remain resistant. TANK-binding kinase 1 (TBK1) has been identified as a synthetic lethal target in this context. Here, we describe the development of UNC8209, an optimized cereblon-based recruiting Proteolysis-targeting chimeras (PROTACs) that selectively and potently degrades TBK1. Compared to earlier compounds, UNC8209 exhibits enhanced degradation efficiency, improved selectivity over off-target kinases such as IKKε, and robust anti-proliferative activity in VHL-deficient RCC models. Sensitivity to UNC8209 correlates with TBK1 activity in general across cell lines. We also generated a negative control compound that confirms target-specific effects. In addition, UNC8209 effectively suppresses tumor growth in vivo with minimal toxicity, supporting its therapeutic potential as a next-generation TBK1-targeting strategy for VHL-deficient cancers.
Project description:VHL loss is the most common genetic alteration event in ccRCC. We profiled histone modifications from VHL-deficient ccRCC primary tumors and cell lines. We show that ccRCCs exhibit a pervasive gain of enhancers around hypoxic and metabolic transcriptional targets. Motif analysis using HOMER revealed significant enrichment of AP-1, ETS, NFĸB and HIFα in tumor enhancers. We generated ChIP-seq binding data for c-Jun, ETS1, NFĸB, and P300, a histone acetyltransferase, in 786-O cells. ChIP-seq profiles of HIF2α and HIF1β in 786-O were already generated previously (GSE34871)
Project description:Clear-cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cell carcinoma (up-to 70% of all RCC types). There is a very close causal correlation between ccRCC and inactivation of the tumor suppressor gene von Hippel-Lindau (VHL) located on chromosome 3p25‐26. Up to 80% of sporadic ccRCC carry genomic mutations or epigenetic inactivation of VHL and nearly 100% familial ccRCC (in VHL disease) contain VHL deficiency. Accumulating evidence has indicated that ccRCC arises at the site of chronic inflammation and this solid tumor contains a substantial number of infiltrated immune cells. This indicates that ccRCC may be induced by the interaction between kidney tubule cells carrying inactivated VHL gene and the inflammatory microenvironment. In this study we characterized the interaction between VHL-deficient kidney tubule cells and macrophages with relevance to ccRCC formation, and found that human macrophages induced by VHL-deficient kidney tubule cells exhibit distinct gene expression program containing the signatures of tumor-associated macrophages that can promote ccRCC progression.
Project description:RASSF1A is frequently biallelically inactivated in clear cell renal cell carcinoma (ccRCC) due to loss of chromosome 3p and promoter hypermethylation. Here we investigated the cellular and molecular consequences of single and combined deletion of the Rassf1a and Vhl tumor suppressor genes to model the common ccRCC genotype of combined loss of function of RASSF1A and VHL. In mouse embryonic fibroblasts and in primary kidney epithelial cells, double deletion of Rassf1a and Vhl caused accumulation of chromosomal segregation defects and increased formation of micronuclei, demonstrating that pVHL and RASSF1A function to maintain genomic integrity. Combined Rassf1a and Vhl deletion in renal epithelial cells in vivo increased proliferation and caused mild tubular disorganization, but did not lead to the development of kidney tumors. Single cell RNA-sequencing unexpectedly revealed that Rassf1a deletion or Vhl deletion both induce the expression of an overlapping set of genes in a sub-population of proximal tubule cells. Many of these genes are also upregulated in the Vhl/Trp53/Rb1 deficient mouse model of ccRCC. In other subsets of proximal tubule cells, combined Vhl/Rassf1a deletion induced the expression of additional genes that were not upregulated in each of the single knockouts. The expression of the human homologues of Rassf1a-regulated genes correlate negatively with RASSF1 expression levels in human ccRCC, suggesting that the loss of RASSF1A function establishes a ccRCC-characteristic gene expression pattern.
Project description:RASSF1A is frequently biallelically inactivated in clear cell renal cell carcinoma (ccRCC) due to loss of chromosome 3p and promoter hypermethylation. Here we investigated the cellular and molecular consequences of single and combined deletion of the Rassf1a and Vhl tumor suppressor genes to model the common ccRCC genotype of combined loss of function of RASSF1A and VHL. In mouse embryonic fibroblasts and in primary kidney epithelial cells, double deletion of Rassf1a and Vhl caused accumulation of chromosomal segregation defects and increased formation of micronuclei, demonstrating that pVHL and RASSF1A function to maintain genomic integrity. Combined Rassf1a and Vhl deletion in renal epithelial cells in vivo increased proliferation and caused mild tubular disorganization, but did not lead to the development of kidney tumors. Single cell RNA-sequencing unexpectedly revealed that Rassf1a deletion or Vhl deletion both induce the expression of an overlapping set of genes in a sub-population of proximal tubule cells. Many of these genes are also upregulated in the Vhl/Trp53/Rb1 deficient mouse model of ccRCC. In other subsets of proximal tubule cells, combined Vhl/Rassf1a deletion induced the expression of additional genes that were not upregulated in each of the single knockouts. The expression of the human homologues of Rassf1a-regulated genes correlate negatively with RASSF1 expression levels in human ccRCC, suggesting that the loss of RASSF1A function establishes a ccRCC-characteristic gene expression pattern.
Project description:VHL loss is the most common genetic alteration event in ccRCC. VHL loss stabilizes hypoxia-inducible factor-2 alpha (HIF2a). We compared the changes in transcriptomics profiles after VHL restoration or HIF2a siRNA knockdown in 786-O cells.