Emergence of heterogeneous nuclear ribonucleoprotein A2/B1 vs loss of E-cadherin: their reciprocal immunoexpression profiles in human pancreatic cancer.

Pancreatic cancer is one of the most lethal human cancers worldwide. It is important to develop new screening methods or biomarkers related to pancreatic carcinogenesis. In our previous work, we identified heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1 as one of the up-regulated proteins in rat pancreatic cancer by using proteomic analysis. In the current study, we extended our research to investigate the immunoexpression of hnRNP A2/B1 protein in paired tumor/nontumor tissues from 42 patients with primary pancreatic ductal adenocarcinoma and its correlation to E-cadherin expression and clinicopathologic features. The results showed that the frequency of hnRNP A2/B1 expression is 71.4% (30/42), and loss of E-cadherin is 61.9% (26/42) in pancreatic cancer tissue. Emergence of hnRNP A2/B1 (P = .027) and loss of E-cadherin (P = .012) expression were significantly associated with poor differentiation of pancreatic cancer. In addition, E-cadherin loss expression was associated with lymph node metastasis (P = .042). Most importantly, there was an inverse correlation between the emergence of hnRNP A2/B1 and loss of E-cadherin expression in pancreatic cancer (P = .01). Collectively, we demonstrate altered expression profile of hnRNP A2/B1 protein in human pancreatic cancer and its reciprocal correlation to E-cadherin expression. These data indicate that hnRNP A2/B1 overexpression is novel and requires further investigation for its potential application in pancreatic carcinogenesis.