Platinum-sensitive and platinum-resistant ovarian cancer tissues show differences in the relationships between mRNA levels of p53, ERCC1 and XPA.

We investigated the association between p53 mRNA expression and clinically relevant surrogates of nucleotide excision repair (ERCC1 and XPA) in 28 ovarian cancer specimens. We observed that platinum-resistant tumors showed higher mRNA levels of p53, ERCC1, and XPA than platinum-sensitive tumors; mRNA expression patterns in responders differed substantially from nonresponders; and p53 expression showed a strong correlation with the expression of ERCC1, and of XPA in platinum-sensitive tumor tissues, but not with platinum-resistant tumors. 47% of the mutations from p53 sequence analysis were not related to clinical response to chemotherapy. We conclude that the p53 influence on DNA repair in human malignancy may vary substantially from tumor to tumor, and that such differences are not necessarily related to the mutational status of p53.