Study Of The Mutation And Expression Of PTEN Gene In Epithelial Ovarian Cancer

Objective To study the relationship between the mutation and expression of PTEN ( phosphatase and tension homology deleted on chromosome ten) and carcinogenesis of epithelial ovarian cancer . Methods The mutations of Exon5 8 of PTEN in 60 cases of malignant epithelial ovarian cancer and 20 cases of benign epithelial ovarian tumors as well as 15 cases of normal ovarian tissues were examined by use of PCR-SSCP and DNA sequence analysis ; and immunohistochemistry was used to evaluate the expression of PTEN protein in epithelial ovarian cancers and benign epithelial ovarian tumors as well as normal ovarian tissues.Results Only 3 samples with PTEN mutation were found in all carcinomas , and the mutation frequency was 5%. No mutations were found in normal ovarian tissues and benign epithelial ovarian tumors. All samples of normal ovarian tissues and benign epithelial ovarian tumors were found to express PTEN protein ,and a low expression rate(77.03%) of PTEN protein was found in epithelial ovarian cancers .The expression level of PTEN protein was higher in well-differentiated group(G1 G2,90.62%) than that of less-differentiated group(G3, 66.67%). Moreover, the expression level of PTEN protein in stage I II (91.67%) was higher than that of stage III IV (70%) . There was no difference between the expression levels of two different histological types and different ages. Conclusion The results suggest that the low expression of PTEN is wellrelated with the carcinogenesis of epithelial ovarian cancer. Loss of PTEN protein expression might play a role in the pathogenesis of epithelial ovarian cancer by some changes other than mutation.