BACKGROUNDThe excision repair cross-complementing gene 1 (ERCC1), which is important in the repair of cisplatin-DNA adducts, is reported to be related to cisplatin resistance in tumor cells. The aim of this study is to investigate the influence of low-dose cisplatin on expression of ERCC1 gene and to confirm the correlation between ERCC1 and cisplatin resistance in human lung adenocarcinoma cell lines.

METHODSA549 and A549/DDP cell lines were treated with 10 μmol/L cisplatin for 12, 24, 48 and 72 h, or treated with 5, 10, 20, 40 μmol/L cisplatin for 24 h respectively. Then the expression of ERCC1 mRNA and protein was measured by RT-PCR and immunocytohistology SABC assay respectively. The resistance of A549/DDP cells was measured by MTT assay.

RESULTSAfter treating with 10 μmol/L cisplatin for 12 h, up-regulation of ERCC1 mRNA and protein was observed in A549 cells, then reached the peak levels in 72 h group. After treating with 5 μmol/L cisplatin for 24 h, up-regulation of ERCC1 mRNA and protein was observed in A549 cells, and when treated with 20 μmol/L cisplatin for 24 h, the ERCC1 mRNA and protein reached the peak levels. Comparing with the parental cells, ERCC1 expression increased obviously in A549/DDP cells, which were established by continuous low-dose cisplatin treatment.

CONCLUSIONSUp-regulation of ERCC1 expression can be induced by low-dose cisplatin in human lung adenocarcinoma cell line A549, and ECRR1 may play roles in cisplatin resistance.