Abstract

Clear cell renal cell carcinoma (ccRCC) is characterized by loss of function of the von Hippel–Lindau tumour suppressor (VHL) and unrestrained activation of hypoxia-inducible transcription factors (HIFs). Genetic and epigenetic determinants have an impact on HIF pathways. A recent genome-wide association study on renal cancer susceptibility identified single-nucleotide polymorphisms (SNPs) in an intergenic region located between the oncogenes MYC and PVT1. Here using assays of chromatin conformation, allele-specific chromatin immunoprecipitation and genome editing, we show that HIF binding to this regulatory element is necessary to trans-activate MYC and PVT1 expression specifically in cells of renal tubular origins. Moreover, we demonstrate that the risk-associated polymorphisms increase chromatin accessibility and activity as well as HIF binding to the enhancer. These findings provide further evidence that genetic variation at HIF-binding sites modulates the oncogenic transcriptional output of the VHL–HIF axis and provide a functional explanation for the disease-associated effects of SNPs in ccRCC.

Highlights

  • Clear cell renal cell carcinoma is characterized by loss of function of the von Hippel–Lindau tumour suppressor (VHL) and unrestrained activation of hypoxia-inducible transcription factors (HIFs)

  • As a first step in analysing mechanisms associated with variant rs35252396, we sought to define the frequency of dysregulated MYC and PVT1 expression in renal cancer

  • When exposed to the hypoxia mimetic and HIF stabilizer dimethyl oxalylglycine (DMOG), we measured an increase of MYC and PVT1 RNA in pVHL re-expressing RCC4 transfectants, whereas no difference was determined in the respective pVHL-defective cells (Fig. 1b), suggesting that MYC is regulated by the HIF pathway in this context

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Summary

Introduction

Clear cell renal cell carcinoma (ccRCC) is characterized by loss of function of the von Hippel–Lindau tumour suppressor (VHL) and unrestrained activation of hypoxia-inducible transcription factors (HIFs). In addition to chromosomal rearrangements, the 8q24 locus is a hot spot for intergenic SNPs associated with a variety of tumours such as colorectal, ovarian, urinary bladder or prostate cancer, Hodgkin’s lymphoma and chronic lymphocytic leukaemia[20,21,22,23,24,25,26,27,28,29,30,31,32,33] Despite this high density of multiple cancerassociated variants in the 8q24.21 region, functional analyses have mainly been restricted to the SNP rs6983267, which is associated with colorectal and prostate cancer. The renal cancer-associated variant rs35252396 observed in the Icelandic population is not in linkage with any other disease-associated SNP in the 8q24.21 region (r2o0.02) (ref. 9), suggesting the involvement of renal cancer-specific mechanisms in generating the predisposition

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