PTEN/MMAC1 mutations correlate inversely with an altered p53 tumor suppressor gene in gynecologic tumors.

OBJECTIVE: This study was conducted to evaluate the different mutations of p53 and compare p53 expression in gynecologic tumors in African American and Chinese women.
METHOD: Tumor samples were collected from Atlanta, Ga, hospitals and National Taiwan University Hospital, Taiwan. Samples were examined for different mutations using electrophoretic variants after single-stranded conformational analysis (SSCA). Cell lines obtained from the American Type Culture Collection were also used.
RESULTS: Mutations were identified in the gene for the tumor protein p53 at codons 156, 157, 176, 183, 246, and 248 at sites predicted to disrupt DNA binding. Collectively, an altered p53 status was found in about 28% of all tumors with similar frequencies observed between the African American and Chinese women. African American or Chinese women did not have common polymorphism.
CONCLUSION: This study showed that in mutations in the PTEN/MMAC1 gene correlated inversely with an altered p53 status. Similar findings were found in 2 tumor cell lines examined. As p53 changes are associated with late stage cancers, we favor the possibility that in certain tumor subtypes, PTEN/MMAC1 genes alteration may be useful clinically in the evaluation of the tumor.