PTEN and p53 Mutations in Endometrial Carcinomas

ABSTRACT

BACKGROUND: Endometrial carcinomas are pathogenetically classified into two major types; endometrioid carcinoma (EC) and serous carcinoma (SC). The most frequently altered gene in EC is the PTEN tumor suppressor gene (TSG). SC is usually associated with mutations in the p53 TSG. METHODS: To further determine the role of PTEN and p53 mutation in endometrial carcinogenesis, the analysis of 33 endometrial carcinomas, including 28 ECs and 5 SCs, for loss of heterozygosity (LOH) on 10q23 and for mutation in all 9 coding exons of PTEN and the 5-8 exons of p53, using SSCP-PCR methods was carried out. RESULTS: LOH was detected in at least one marker in 12 (54.5%) of 22 ECs, but in only one (20.0%) of 5 SCs. Somatic PTEN mutations were detected in 10 (35.7%) of 28 ECs. PTEN was altered in 67.9% of ECs and in 20.0% of SCs, including those with 10q23 LOH. No PTEN mutations were found among the SCs. Somatic p53 mutations were detected in 2 (7.1%) of 28 ECs and 3 (60.0%) of 5 SCs. CONCLUSIONS: PTEN gene alterations contribute to the pathogenesis of an endometrioid subtype of endometrial carcinoma, but not to the serous type. In contrast, p53 plays an important role in the pathogenesis of SCs.