[Establishment of a Multidrug Resistance Cell Line A549/cDDP of Human Lung Adenocarcinoma and Expression Analysis of Multidrug Resistance-Associated Genes.].

Background: It has been proven that chemotherapy failure caused by multidrug resistance in lung tumor cells is the main cause for the patient's survival rate. The aim of this study is to establish a multidrug resistance cell line of human lung adenocarcinoma and study the mechanism of multidrug resistance.

Methods: Human lung adenocarcinoma cell line A549 was induced to multidrug resistance cell line A549/cDDP by intermittent administration of high dose of cisplatin (cDDP). The multidrug resistance was detected by using MTT assay. The levels of expression of MDR-1 gene-coded P-glycoportein (P-gp), multidrug resistance-associated protein (MRP), and GSH/GST were examined by flow cytometric assay. The levels of expression of MDR and MRP gene were also detected by RTPCR in both A549/cDDP and A549 cell lines.

Results: A549/cDDP was resistant to many anti-tumor agents. The IC50 of A549/cDDP was 16.87 times higher than that of A549. The expressions of P-gp and MRP in A549/cDDP were increased significantly to (70.5+/-4.9)% and (29.4+/-2.9)%, respectively, vs (42.4+/-5.6)% and (21.4+/-3.5)% in A549. There was no difference of the GSH/GST expression between A549/cDDPand A549 cells

Conclusions: A549/cDDP is a model with multidrug resistance and the levels of MDR and MRP mRNA expressions are remarkably higher in A549/cDDP than those in A549.