EXPRESSION OF GENES OF POTENTIAL IMPORTANCE IN THE RESPONSE TO CHEMOTHERAPY AND DNA-REPAIR IN PATIENTS WITH OVARIAN-CANCER

The expression of different genes potentially involved in DNA repair a nd in cell responses to chemotherapy was evaluated in 33 previously un treated ovarian cancer patients. In biopsies of the same patients the expression of repair genes O-6-methylguanine DNA methyltransferase (MG MT), 3-methyladenine DNA glycosylase (MAG), ERCC1, MDR-1, DNA topoisom erase I, DNA topoisomerase II alpha, and glutathione S-transferase-pi (GST-pi) was assessed by Northern blot analysis. No direct statistical correlation was found between the expression of these genes and the r esponse to chemotherapy (mainly platinum-based with or without doxorub icin and cyclophosphamide). Univariate analysis showed a weak negative correlation (P = 0.037) between the expression of ERCC1 and mortality , whereas no statistically significant correlation was found for other parameters. The MDR-1 gene encoding for the P-glycoprotein P-170 was mostly undetectable in these patients (as assessed by Northern blottin g), whereas relatively high levels of MAG and MGMT were found in the m ajority of patients. A statistically significant correlation was found between the expression of DNA topoisomerase I and the expression of e ither ERCC1 (P = 0.0026) or GST-pi (P = 0.0279). (C) 1997 Academic Pre ss.