Expression Of Pituitary Tumor Transforming Gene (PTTG) In Estrogen-induced Pituitary Tumorigenesis In Wistar Rats

Objective: The aim of this study was to explore expression of pituitary tumor transforming gene (PTTG) in estrogen-induced pituitary tumorigenesis in rats, to investigate its role in this process.Methods: 40 female Wistar rats of 8 weeks old were used in our study. All animals were surgically ovariectomized before experiment. According to random distribution method, they were divided equally into two groups: control groups and experimental groups. The female Wistar rats were induced with benzoic acid estradiol by peritoneal injection. Expression of PTTG mRNA levels in the pituitary glands were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The data for PTTG mRNA levels were analyzed by the soft ware of SPSS 11.5 for windows.Results: Significant increases in pituitary weight were noted three months after peritoneal injection of estradiol ( 52.35±4.97 ) mg. The serum prolactin concentration also increased sharply in the rats of estrogenized groups (198.23±93.07)ng/ml. They were approximately 4 fold compared to those of control groups. The histopathological examination for pituitary tissues in experimental groups was also consistent with the diagnosis of pituitary adenoma. The expression level of PTTG mRNA in pituitary tumors (1.41±0.13) of experimental groups was significantly higher than that of control groups (0.24±0.08) ((t =33.945,P <0.001)).Conclusion: It can be inferred from our study that chronic treatment with estradiol can result in pituitary adenoma in female Wistar rats. PTTG mRNA in the pituitary glands was regulated by estradiol, with possible involvement in estradiol induced tumorigenesis in rats.