P53 GENE MUTATION ANALYSIS AND ANTISENSE-MEDIATED GROWTH-INHIBITION OF HUMAN OVARIAN-CARCINOMA CELL-LINES

Targeting dysfunctional gene expression in the cancer cell with gene-s pecific therapeutics requires knowledge of the structure and expressio n of the designated gene. Because of the prevalence of p53 dysfunction in epithelial ovarian carcinoma, modulation of the expression of this tumor suppressor gene is an attractive target for gene therapy. We se quenced the p53 gene and analyzed its expression in 10 ovarian cancer cell lines, Only five cell line mutations were encountered, three asso ciated with a loss of heterozygosity, Thus, neither p53 mutation nor a llelic toss is required for ovarian carcinogenesis or propagation of o varian cancer cell lines in vitro. SSCP screening, but not immunohisto chemical staining, correlated with results of direct genomic sequencin g. All p53 immunohistochemical-negative cell lines produced p53 mRNA. p53 expression in two of the cell lines differed from that reported by another laboratory, underscoring the importance of the knowledge of t arget gene expression in a given cell line in a given laboratory. We d esigned pilot studies: of antisense oligodeoxynucleotides directed aga inst the p53 gene based on our sequence data. Differential growth inhi bition of the A2780-CP-20 cell line (mutant p53 protein), but not of t he OVCAR-3 cell line (wild-type p53 protein) confirmed the potential u sefulness of this strategy. (C) 1996 Academic Press, Inc.