Effect On Sensitivity Of Human Cancer Cells To Drug By Small Interfering RNA-induced Suppression Of ERCC1

Background & Objection Platinum compounds is one of the most important anticancer drugs and believed to induce tumor cell death as a result of the formation of platinum-DNA adducts, which inhibit DNA replication and/or transcription. However, the presence of intrinsic or acquired resistance to platinum in cancer cells remains a major obstacle to successful cancer chemotherapy. NER pathway is the major mechanism despite the fact that laboratory studies on human cancer cell lines suggests that the resistance to platinum compounds is multifactorial. The rate-limiting step in the NER process is recognition and repair that ERCC1 involved in. The level of ERCC1 gene expression, which is important in the repair of the cisplatin-DNA adducts and is reported to be the level of the cisplatin resistance in tumor cells. This research is to study drug resistance and verify the effect of ERCC1 on drug resistance by blocking ERCC1 gene expression in ovarian cancer cell lines by SiRNA.Methods ERCC1 mRNA specific SiRNA expressing vector (pGenesil-1/ercc11 and pGenesil-1/ercc12) was constructed and then transfected into human ovarian cancer cell lines. RT-PCR and Western blotting were used to detect the mRNA and protein expression level in the cells. MTT assay was used to study the effect on drug resistance in the cell lines.Results After transfection with pGenesil-1/ercc11 and pGenesil-1/ercc12, the mRNA and protein expression level of ERCC1 was obviously decreased. MTT assay showed decreased drug resistance to cisplatin in the lines. Conclusions This study demonstrate the feasibility of utilizing ERCC1 SiRNAs to specially reduce the ERCC1 expression level in human cancer and provides direct evidence for the potential use of ERCC1 SiRNA as a chemotherapy-sensitizing agent.