Hypomethylation of the MN/CA9 promoter and upregulated MN/CA9 expression in human renal cell carcinoma

Br J Cancer. 2001 Aug 17;85(4):563-7. doi: 10.1054/bjoc.2001.1951.


MN/CA9 is a cancer-related gene, frequently activated in human renal cell carcinomas (RCCs). To reveal the activation mechanism, we investigated the relationship between methylation status of the MN/CA9 promoter region and gene expression using 13 human RCCs, and examined the effect of in vitro CpG methylation on the MN/CA9 promoter activity using a human RCC cell line (SK-RC-44), expressing MN/CA9. MN/CA9 expression was evaluated by RT-PCR and observed in 10 of 13 RCCs (77%). A total of 9 out of 10 MN/CA9 -positive RCCs (90%) contained clear cell components. Methylation status of 6 CpGs in the MN/CA9 promoter region was decided by using the bisulfite genomic sequencing protocol. Out of 13 RCCs 9 (69%) showed partial hypomethylation of the CpG at -74 bp, while the other 4 RCCs and 3 normal kidney tissue samples showed complete methylation. Hypomethylation of the CpG at -74 bp was strongly correlated with MN/CA9 expression. Luciferase assay revealed that the MN/CA9 promoter activity was strongly suppressed by methylation of the CpG at -74 bp. These findings suggest that hypomethylation of the CpG at -74 bp in the MN/CA9 promoter region might play an important role in this gene activation of human RCC.

MeSH terms

  • Carcinoma, Renal Cell / genetics*
  • Carcinoma, Renal Cell / pathology
  • DNA Methylation*
  • DNA Primers
  • DNA, Neoplasm
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Kidney Neoplasms / genetics*
  • Kidney Neoplasms / pathology
  • Promoter Regions, Genetic / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transcriptional Activation
  • Tumor Cells, Cultured
  • Up-Regulation


  • DNA Primers
  • DNA, Neoplasm