New and old genes associated with topotecan resistance development in ovarian cancer cell lines

Abstract

Background: Low effectiveness of chemotherapy in ovarian cancer results from development of drug resistance. Topotecan is a drug used as second-line chemotherapy for this cancer type. We analyzed development of topotecan resistance in ovarian cancer cell lines. Materials and Methods: A chemosensitivity assay, MTT test, was performed to assess drug resistance. Quantitative polymerase chain reaction (Q-PCR) assays were performed to determine ABCB1, ABCG2, ALDH1A1, IFIH1, SAMD4 and EPHA3 gene expression. Results: We observed dose-dependent responses to topotecan. In all topotecan-resistant cell lines an overexpression of ABCG2, IFIH1 and SAMD4 genes was observed. Expression of ABCB1 gene was observed in one cell line. Expression of ALDH1A1 was up-regulated in A2780 and down-regulated in SKOV-3-resistant cell lines. Short-time exposure led to similar patterns of gene expression for the investigated genes. Conclusion: Expression of ABCG2 and ABCB1 genes plays the most important role in topotecan resistance. The role of other investigated genes seems to be complementary.