[Detection of mutation and protein expression of PTEN gene in endometrial carcinoma]

PTEN (phosphatase and tensin homolog deleted on chromosome ten), a novel tumor suppressor gene identified recently, is called the house-keeping gene of endometrium. However, little is known about its precise role in genesis and development of endometrial carcinoma. In the present study, the mutation and protein expression of PTEN gene were investigated to seek the clinical significance.

Fifty-two endometrial carcinoma samples and 10 normal endometrial tissues were collected. The mutations of exon 5 and exon 8 of PTEN gene were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequencing analysis. The expression of PTEN protein was evaluated by immunohistochemistry method. The results associated with clinical pathological features were analyzed.

In endometrial carcinomas, the rates of mutation and protein expression deletion of PTEN were 25% and 60%, respectively, which were significantly higher than that of normal endometrium (0%) (P< 0.05). The samples at pathological G(1) and G(2) and depth of myometrial invasion less than 1/2 demonstrated higher mutation rate than that of G3 and depth of myometrial invasion more than or equal to 1/2 (P< 0.05). In contrast, the rate of protein expression deletion of G(1) and G(2) was significantly lower than that of G3 (P< 0.05). Both mutation and protein expression deletion showed statistical differences between endometrioid adenocarcinoma and other types of endometrial carcinomas (P< 0.05), but no significant difference was found at different surgical-pathological stage (P >0.05).

Mutation and positive protein expression of PTEN occurred more frequently in the endometrial carcinoma cases with low pathological stages.