E-cadherin and DAP kinase in pancreatic adenocarcinoma and corresponding lymph node metastases

Oncol Rep. 2006 May;15(5):1125-31.

Abstract

E-cadherin and DAP kinase have been implicated as 'invasion suppressor' genes in human cancer. The aim of this study was to analyze the methylation status of E-cadherin and DAP kinase and the expression of the protein in the metastatic lesions and to compare it with the expression in the primary tumor. Methylation-specific PCR of the DAP kinase and E-cadherin promoter was performed in 28 primary adenocarcinomas of the pancreas and in 13 corresponding regional lymph node metastases. The presence of E-cadherin and DAP kinase protein was assessed by immunohistochemistry. Metastatic lymph nodes showed a significant different expression profile from the primary tumor. E-cadherin methylation was observed in 8/28 (29%) and loss of protein expression was observed in 16/28 (57%) of pancreatic carcinomas. E-cadherin methylation was observed in 7/13 (54%) and loss of protein expression was observed in 11/13 (85%) lymph node metastases (p=0.047). DAP kinase methylation occurred in 11/28 (39%) pancreatic carcinomas and loss of protein expression was observed in 13/28 (46%). DAP kinase was methylated in 6/13 (46%) lymph node meta-stases and loss of protein expression was observed in 10/13 (77%) (p=0.039). Comparing primary tumor and corresponding lymph node metastases in 13 cases, the status of E-cadherin methylation was discordant in 2 cases. The protein expression pattern of E-cadherin and DAP kinase was discordant in 4 and 3 cases respectively. Unmethylated tumor samples did not express E-cadherin in 12 and DAP kinase protein in 6 cases. Our results demonstrate that reduction of E-cadherin and DAP kinase expression is more frequent in lymph node metastases than in the primary tumor and methylation of the promoter region contributes to this reduction; however, an alternative mechanism of inactivation seems to exist.

MeSH terms

  • Adenocarcinoma / genetics*
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / pathology
  • Aged
  • Apoptosis Regulatory Proteins
  • Cadherins / genetics*
  • Cadherins / metabolism
  • Calcium-Calmodulin-Dependent Protein Kinases / genetics*
  • Calcium-Calmodulin-Dependent Protein Kinases / metabolism
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism
  • Carcinoma, Pancreatic Ductal / pathology
  • DNA Methylation
  • Death-Associated Protein Kinases
  • Female
  • Gene Expression Profiling
  • Humans
  • Lymphatic Metastasis / genetics
  • Lymphatic Metastasis / pathology
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Promoter Regions, Genetic / genetics*

Substances

  • Apoptosis Regulatory Proteins
  • Cadherins
  • Death-Associated Protein Kinases
  • Calcium-Calmodulin-Dependent Protein Kinases