OBJECTIVES: To investigate the expressions of E-cadherin and alpha-catenin in pancreatic carcinoma and their relationship with biological behaviors, and clarify the mechanism of invasion and metastasis of pancreatic cancer.
METHODS: The expressions of E-cadherin and alpha-catenin was examined in 47 patients with infiltrative ductal adenocarcinoma of the pancreas and 12 specimens of normal pancreatic tissues by immunohistochemical technique (PicTureTM two-step method). Proliferation cell nuclear antigen (PCNA) was tested as an index of the proliferation degree of pancreatic cancer cells.
RESULTS: The immunoreactivity of E-cadherin and alpha-catenin was expressed by normal ductal and acinar cells with strong membranous staining at the intercellular border in 12 specimens of normalpancreatic tissues. The abnormal rate of E-cadherin expression in pancreatic cancerwas 53.2% (25/47), and it was significantly related to differentiation, high proliferation degree and lymph node and liver metastases (P<0.01, 0.05, 0.05 and 0.01, respectively). 61.7% patients with pancreatic cancer (29/47) showed abnormal expression of alpha-catenin. There was a good correlation among alpha-catenin expression, histological grade, and lymph node and liver metastases (P<0.05,0.05 and 0.01, respectively). No significant association was found among abnormal expressions of E-cadherin and alpha-catenin, tumor size, invasion, and 1-year survival rate of patients (P>0.05, all). There was a positive relationship between the expressions of E-cadherin and alpha-catenin in the 47 patients with pancreatic cancer (P<0.01, r=0.88).
CONCLUSIONS: Pancreatic cancer likely occurs in case of the inactivation of E-cadherin and alpha-catenin genes and abnormal expression of proteins, which significantly correlate with tumorigenesis, proliferation, differentiation, and lymph node or liver metastasis of pancreatic cancer.