Expression of bcl-xL and cyclin D1 in pancreatic carcinoma and their relationship with signal transducer and activator of transcription-3(STAT3)

Objective To investigate the expression of anti-apoptosis genes bcl-xL and cyclin D1 in human pan- creatic carcinoma tissues,and their relationship with clinico-pathological characteristics including the expression of phos- phorylated signal transducer and activator of transcription-3 (PSTAT3).Methods PSTAT3,bcl-xL and cyclin D1 protein expression in 41 pancreatic cancer tissues and 20 normal pancreatic tissues were detected by immunohistochemical stai- ning.Simultaneously,the proliferative index (PI) and apoptotic index (AI) of the tumor cells were scored by Ki67 and TUNEL staining,respectively.Results The expression rates of PSTAT3,bcl-xL and cyclin D1 in pancreatic carcinoma were 70.7%(29/41),87.8%(36/41) and 61.0%(25/41),respectively,significantly higher than those in the normal pancreatic tis- sues.Positive correlation was found between the expression of bcl-xL,cyclin D1 and PSTAT3 (P＜0.05).Furthermore, PSTAT3 expression was closely related with the clinical staging,status of lymph node metastasis,increased PI and decreased AI(P＜0.05).Conclusions Activated STAT3 is closely related to the over-expression of anti-apoptosis genes bcl-xL and cy- clin D1 in human pancreatic carcinoma,and might play an important role in the tumorigenesis of this lethal malignancy.