Expression and significance of EZH_2 and PTEN in pancreatic cancer and non-cancerous pancreatic tissues in rats / 中国普通外科杂志

ABSTRACT

Objective To study the expressive levels of EZH2 and PTEN in pancreatic cancer and non-cancerous tissue,and the effects on carcinogenesis of rat pancreas.Methods dimethylbenzathracene(DMBA) was directly implanted into the parenchyma of rat pancreas(group A,group B).The rats of group B were treated with 1 mL trichostatin A(TSA) solution(1?g/mL) intravenously per weer 1 week after the model were set up.The rats of group A,B were killed within 3-5 months and the rats in the control(C group) were executed at 5 months to observe the develope of pancreatic cancer by macrograph and microscopy,The EnVisionTM immunohistochemistry was used to assay the expression of EZH2 and PTEN in above pancreatic specimens.Results(1) The incidence of pancreatic cancer within 3-5 months in group A was 48.7%(18/37),including 17 cases of ductal adenocarcinoma and 1 case of fibrosarcoma.The incidence of pancreatic cancer in group B was 33.3%(12/36),including 11 cases of ductal adenocarcinoma and 1 cases of fibrosarcoma.The mean maximal diameter of mass was significantly higher in group A than that in group B(P 0.05).The non-cancerous pancreatic tissues with positive expression of EZH2 and/or negative expression of PTEN showed mild to severe atypical hyperplasia of ductal epithelium.An inconsistency was found between the expression of EZH2 and PTEN in ductal adenocarcinoma(P =0.045).Pancreas of group C showed negative expression of EZH2 and positive expression of PTEN.Two cases of fibrosarcoma showed negative expression of EZH2 and PTEN.Conclusions By use of higher dose of DMBA directly implanted into the parenchyma of pancreas,high incidence of pancreatic cancer can be obtained.TSA could have an inhibitive effect on carcinogenesis and growth of pancratic cancer.The activation of EZH2 gene and inactivation of PTEN gene might have Key effects on pancreas carcinogenesis induced by DMBA in rat.