MUTATION OF THE PTEN TUMOR-SUPPRESSOR GENE IS NOT A FEATURE OF OVARIAN CANCERS

Objective. The PTEN tumor suppressor gene on chromosome 10q23 undergoe s inactivating mutations in several types of malignancies including gl ioblastomas and prostate and endometrial carcinomas. The aim of this s tudy was to determine if mutation of the PTEN tumor suppressor gene is a feature of sporadic or BRCA1-associated ovarian carcinomas. Methods . Genomic deoxyribonucleic acid was extracted from 11 ovarian cancer c ell lines and 50 frozen ovarian cancers, including 4 cases that develo ped in women with germline mutations in the BRCA1 breast/ovarian cance r susceptibility gene. The polymerase chain reaction was used to ampli fy each of the nine exons and intronic splice sites of the PTEN gene. These products were then screened for mutations using single strand co nformation polymorphism analysis. Variant bands were further evaluated using automated DNA sequencing. Results. A previously unreported sile nt polymorphism at codon 240 (TAT to TAG) in exon 7 was noted in one o f the primary ovarian carcinomas. Mutations in the PTEN gene were not found in any of the 50 primary ovarian cancers or 11 immortalized ovar ian cancer cell lines. Conclusion. Alteration of the PTEN tumor suppre ssor gene does not appear to be a feature of sporadic or BRCA1-associa ted ovarian cancers. (C) 1998 Academic Press.