VHL and HIF-1α: gene variations and prognosis in early-stage clear cell renal cell carcinoma

Med Oncol. 2014 Mar;31(3):840. doi: 10.1007/s12032-014-0840-8. Epub 2014 Jan 21.

Abstract

Von Hipple-Lindau gene (VHL) inactivation represents the most frequent abnormality in clear cell renal cell carcinoma (ccRCC). Hypoxia-inducible factor-1α (HIF-1α) expression is regulated by O2 level. In normal O2 conditions, VHL binds HIF-1α and allows HIF-1α proteasomal degradation. A single-nucleotide polymorphism (SNP) has been found located in the oxygen-dependent degradation domain at codon 582 (C1772T, rs11549465, Pro582Ser). In hypoxia, VHL/HIF-1α interaction is abolished and HIF-1α activates target genes in the nucleus. This study analyzes the impact of genetic alterations and protein expression of VHL and the C1772T SNP of HIF-1α gene (HIF-1α) on prognosis in early-stage ccRCC (pT1a, pT1b, and pT2). Mutational analysis of the entire VHL sequence and the genotyping of HIF-1α C1772T SNP were performed together with VHL promoter methylation analysis and loss of heterozygosis (LOH) analysis at (3p25) locus. Data obtained were correlated with VHL and HIF-1α protein expression and with tumor-specific survival (TSS). VHL mutations, methylation status, and LOH were detected in 51, 11, and 12% of cases, respectively. Our results support the association between biallelic alterations and/or VHL silencing with a worse TSS. Moreover, we found a significant association between the HIF-1α C1772C genotype and a worse TSS. The same association was found when testing the presence of HIF-1α protein in the nucleus. Our results highlight the role of VHL/HIF-1α pathway in RCC and support the molecular heterogeneity of early-stage ccRCC. More important, we show the involvement of HIF-1α C1772T SNP in ccRCC progression.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / genetics*
  • Biomarkers, Tumor / metabolism
  • Carcinoma, Renal Cell / genetics*
  • Carcinoma, Renal Cell / metabolism
  • Carcinoma, Renal Cell / pathology
  • DNA Mutational Analysis
  • Female
  • Follow-Up Studies
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Immunoenzyme Techniques
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / metabolism
  • Kidney Neoplasms / pathology
  • Loss of Heterozygosity
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Neoplasm Staging
  • Polymerase Chain Reaction
  • Polymorphism, Single Nucleotide / genetics
  • Prognosis
  • Promoter Regions, Genetic
  • Tissue Array Analysis
  • Von Hippel-Lindau Tumor Suppressor Protein / genetics*
  • Von Hippel-Lindau Tumor Suppressor Protein / metabolism

Substances

  • Biomarkers, Tumor
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Von Hippel-Lindau Tumor Suppressor Protein
  • VHL protein, human