Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. Gene expression data from metastatic 786-M1A cells with and without reintroduced HA-VHL. The empty vector, pBabe-puro, was used as control.
Project description:Changes in mRNA abundance upon HIF activation and/or hypoxia in VHL-defective kidney cancer cell were analysed. Sequencing of the 5′ ends of mRNAs (5′ end-Seq) was applied to VHL-defective kidney cancer cell lines with or without reintroduction of VHL and/or with hypoxic incubation (1% O2 for 24h) to analyse the abundance of mRNAs resolved by their transcription start sites. In addition, the contribution of HIF pathway was confirmed using 786-O cells in which HIF1B was inactivated.
Project description:Changes in translational efficiency of mRNAs consequent on alteration of HIF and/or mTOR pathway activity in VHL-defective kidney cancer cell were analysed. High-resolution polysome profiling followed by sequencing of the 5′ ends of mRNAs (HP5) was used to measure translational efficiency of mRNAs resolved by their transcription start sites. HP5 was applied to VHL-defective kidney cancer cell lines with or without VHL reintroduction and/or mTOR inhibition with Torin 1 treatment. In addition, the contribution of HIF2A/EIF4E2 pathway was assessed using 786-O cells in which EIF4E2 was inactivated.
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. Gene expression profiles of 786-O renal cell carcinoma cells and metastatic subpopulations isoloated by in vivo selection in immunocomrpmized mice. The derivatives are significantly enriched in the metastatic propensity as measure by experimental metastasis assays.
Project description:The human renal cancer cell line 786-0 was transfected with 3 vectors allowing the doxycycline-inducible expression of 1) the full length wild type sequence of VHL: 786-0 VHL WT, VHL+/+, 2) the R167Q mutant : 786-0 R167Q, VHL mutated, 3) the empty vector : 786-0 EV, VHL-/-. The aim of the study was to examine whether the VHL-R167Q mutation, which is associated with a high risk of developping clear cell renal carcinomas, could impact the plasticity of renal carcinoma cells.
Project description:786-0 is a cell line derived from a clear cell renal carcinoma. Previous studies have shown that the 786-O cell line harbors an inactivating mutation in the von-Hippel Lindau (VHL) gene. Mutations in the VHL gene occur in the majority of sporadic clear cell renal cell. To determine how inactivation of the VHL affects cellular functions, we created a derivative of 786-0, which we call 786-VHL in which a functional allele of VHL has been introduced back into the 786-O cell line. The renal cell carcinoma cell line 786-0, which harbors a mutated allele of VHL, was compared to a cell line derived from 786-0, termed 786-VHL, that contains a functional allele of VHL. Genes whose expression characteristics were dependent on functional VHL were identified.
Project description:Inactivation of the von Hippel-Lindau tumor suppressor gene, VHL, is an archetypical tumor-initiating event in clear cell renal carcinoma (ccRCC) that leads to the activation of hypoxia-inducible transcription factors (HIFs). However, VHL mutation status in ccRCC is not correlated with clinical outcome. Here we show that during ccRCC progression, cancer cells exploit diverse epigenetic alterations to empower a branch of the VHL-HIF pathway for metastasis, and the strength of this activation is associated with poor clinical outcome. By analyzing metastatic subpopulations of VHL-deficient ccRCC cells, we discovered an epigenetically altered VHL-HIF response that is specific to metastatic ccRCC. Focusing on the two most prominent pro-metastatic VHL-HIF target genes, we show that loss of polycomb repressive complex 2 (PRC2)-dependent histone H3 Lys27 trimethylation (H3K27me3) activates HIF-driven chemokine (C-X-C motif) receptor 4 (CXCR4) expression in support of chemotactic cell invasion, whereas loss of DNA methylation enables HIF-driven cytohesin 1 interacting protein (CYTIP) expression to protect cancer cells from death cytokine signals. Thus, metastasis in ccRCC is based on an epigenetically expanded output of the tumor-initiating pathway. Gene expression data from 786-O cells after 3-day treatment with 100uM 5’-aza-deoxycytidine (5DC) or vehicle (DMSO).