MULTIPLEX PCR SCREENING DETECTS SMALL P53 DELETIONS AND INSERTIONS INHUMAN OVARIAN-CANCER CELL-LINES

Mutations at the p53 tumor suppressor gene locus are a frequent geneti c alteration associated with human ovarian carcinoma. Little informati on exists regarding whether mutational events occur other than point m utations and large deletions, causing loss of heterozygosity. Small in tragenic deletions and insertions in the p53 gene have been observed i n various human neoplasias. We developed a multiplex polymerase chain reaction (MPCR) screening assay to amplify the complete p53 coding reg ion from genomic DNA in a single step. Deletions and/or insertions wer e found in six out of 11 newly established ovarian carcinoma cell line s. MPCR detected deletions as small as 2bp, as confirmed by nucleotide sequence analysis. Most of the observed alterations (6/7) were homozy gous or hemizygous. Structural aberrations of the p53 gene possibly le ading to loss of p53 cell cycle control may be a consequence of a slip ped-mispairing mechanism in rapid DNA replication during repetitious o vulation and wound repair of ovarian epithelial cells. MPCR may be a v aluable tool for screening for possible p53 deletion and insertion mut ations not only in ovarian cancer but also in other malignancies.