Methylation of Protocadherin 10, a Novel Tumor Suppressor, Is Associated With Poor Prognosis in Patients With Gastric Cancer

Gastroenterology. 2009 Feb;136(2):640-51.e1. doi: 10.1053/j.gastro.2008.10.050. Epub 2008 Oct 29.

Abstract

Background & aims: By using methylation-sensitive representational difference analysis, we identified protocadherin 10 (PCDH10), a gene that encodes a protocadherin and is silenced in a tumor-specific manner. We analyzed its epigenetic inactivation, biological effects, and prognostic significance in gastric cancer.

Methods: Methylation status was evaluated by combined bisulfite restriction analysis and bisulfite sequencing. The effects of PCDH10 re-expression were determined in growth, apoptosis, proliferation, and invasion assays. PCDH10 target genes were identified by complementary DNA microarray analysis.

Results: PCDH10 was silenced or down-regulated in 94% (16 of 17) of gastric cancer cell lines; expression levels were restored by exposure to demethylating agents. Re-expression of PCDH10 in MKN45 gastric cancer cells reduced colony formation in vitro and tumor growth in mice; it also inhibited cell proliferation (P < .01), induced cell apoptosis (P < .001), and repressed cell invasion (P < .05), up-regulating the pro-apoptosis genes Fas, Caspase 8, Jun, and CDKN1A; the antiproliferation gene FGFR; and the anti-invasion gene HTATIP2. PCDH10 methylation was detected in 82% (85 of 104) of gastric tumors compared with 37% (38 of 104) of paired nontumor tissues (P < .0001). In the latter, PCDH10 methylation was higher in precancerous lesions (27 of 45; 60%) than in chronic gastritis samples (11 of 59; 19%) (P < .0001). After a median follow-up period of 16.8 months, multivariate analysis revealed that patients with PCDH10 methylation in adjacent nontumor areas had a significant decrease in overall survival. Kaplan-Meier survival curves showed that PCDH10 methylation was associated significantly with shortened survival in stage I-III gastric cancer patients.

Conclusions: PCDH10 is a gastric tumor suppressor; its methylation at early stages of gastric carcinogenesis is an independent prognostic factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnosis*
  • Adenocarcinoma / genetics*
  • Adenocarcinoma / metabolism
  • Adult
  • Aged
  • Aged, 80 and over
  • Animals
  • Apoptosis / physiology
  • Biomarkers, Tumor / metabolism
  • Cadherins / genetics*
  • Cadherins / metabolism*
  • Case-Control Studies
  • Cell Line, Tumor
  • Cell Movement / physiology
  • Cell Proliferation
  • DNA Methylation / physiology*
  • Female
  • Gastric Mucosa / metabolism
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Mice
  • Mice, Nude
  • Middle Aged
  • Multivariate Analysis
  • Neoplasm Staging
  • Precancerous Conditions / diagnosis
  • Precancerous Conditions / genetics
  • Precancerous Conditions / metabolism
  • Prognosis
  • Stomach / pathology
  • Stomach / physiopathology
  • Stomach Neoplasms / diagnosis*
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / metabolism
  • Transplantation, Heterologous

Substances

  • Biomarkers, Tumor
  • Cadherins
  • PCDH10 protein, human