POU5F1 and familial pancreatic carcinoma: In addition, the endogenous expression of PCNA, indicated by western blot analysis, was significantly decreased in the Lv-shOCT4 group compared with the NC and CON groups (P<0.01; Fig. 4B and C), indicating that knockdown of OCT4 may inhibit the invasive potential of pancreatic cancer cells through downregulation of PCNA expression.