Periostin, a matrix specific protein, is associated with proliferation and invasion of pancreatic cancer.

Overexpression of periostin is present in various malignant tumors and correlates with disease progression. However, its clinicopathological significance in pancreatic cancer is currently not known. Expression of periostin was analyzed by RT-PCR and western blotting in pancreatic cancers and cell lines. Using immunohistochemistry, expression of periostin in pancreatic cancers was evaluated according to factors influencing overall survival with Kaplan-Meier analysis. Ectopic expression of periostin was used to examine the effects of periostin on proliferation and invasiveness of pancreatic cancer cells in vitro. There was no detectable periostin mRNA and protein expression in the 4 pancreatic cell lines. Expression of periostin was found to be up-regulated in pancreatic cancer compared to the adjacent tumor free (TF) tissues by western blotting. The positive ratio of periostin expression in the neoplastic stroma was significantly correlated with the depth of invasion (p=0.007) and lymph node metastasis (p=0.027). Survival analysis showed that stromal or epithelium expression of periostin was associated with poor survival (p=0.035, p=0.022, log-rank test, respectively). In vitro studies showed that periostin was able to promote proliferation and invasiveness of pancreatic cancer cells. These results suggest that periostin may be involved in the progression and invasion of pancreatic cancer.