Promoter hypermethylation of Ras-related GTPase gene RRAD inactivates a tumor suppressor function in nasopharyngeal carcinoma

Cancer Lett. 2012 Oct 28;323(2):147-54. doi: 10.1016/j.canlet.2012.03.042. Epub 2012 Apr 6.

Abstract

Nasopharyngeal carcinoma (NPC) is endemic in southern China. In a genome-wide screen for genes inactivated by promoter hypermethylation, we identified Ras-related associated with diabetes (RRAD). Expression of RRAD was down-regulated in 83.3% (30/36) of the biopsies from NPC patients. RRAD was aberrantly methylated in 74.3% (26/35) of primary tumors, but not in normal nasopharyngeal epithelium. Ectopic RRAD expression in NPC cell lines inhibited the cell growth, colony formation, and cell migration. These results indicate that RRAD might act as a functional tumor suppressor and its epigenetic inactivation may play an important role in NPC development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Biopsy
  • Cell Line, Tumor
  • DNA Methylation*
  • DNA Primers
  • Genes, Tumor Suppressor*
  • Humans
  • Nasopharyngeal Neoplasms / genetics*
  • Nasopharyngeal Neoplasms / pathology
  • Promoter Regions, Genetic*
  • RNA, Small Interfering
  • Real-Time Polymerase Chain Reaction
  • ras Proteins / genetics*

Substances

  • DNA Primers
  • RNA, Small Interfering
  • RRAD protein, human
  • ras Proteins