[Study of the mutation and expression of PTEN gene in endometrial carcinoma and epithelial ovarian cancer].

OBJECTIVE: To study the relationship between the mutation and protein expression of PTEN and carcinogenesis of endometrial carcinoma and epithelial ovarian cancer. METHODS: The mutations of Exon5, 8 of PTEN in epithelial ovarian cancer tissues and endometrial carcinoma tissues were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequence analysis; and immunohistochemistry was used to evaluate the expression of PTEN protein in corresponding tissues. RESULTS: The mutation rate (25%) in endometrial carcinomas was higher than that of normal tissue (0, P < 0.05) and the mutation rate had significant relationship with pathological grade, histological type and depth of myometrial invasion (P < 0.05). PTEN protein expression deletion rate (60%) in endometrial carcinoma tissues was higher than that of normal tissue (0, P < 0.05). The protein expression deletion was significantly associated with pathological grade and histological type (P < 0.05), but was irrelevant to stage and depth of myometrial invasion (P > 0.05). The mutation frequency in epithelial ovarian carcinomas (5%) had no significant difference compared with those of normal ovarian tissues (0) and benign epithelial ovarian tumors (0). PTEN protein expression deletion in epithelial ovarian cancers (23%) was higher than those of normal ovarian tissues (0) and benign epithelial ovarian tumors (0, P < 0.05). The expression level of PTEN protein varied between different stages and differential grades. There was no difference between the expression levels of two different histological types and different ages. CONCLUSION: The mutation and expression deletion of PTEN played a role in the carcinogenesis of endometrial cancers, however, in epithelial ovarian cancers PTEN gene played its role by expression deletion other than mutation.