Objective:To study the effect of small interfering RNAs(siRNAs) combined with Brucea javanica oil emulsion targeted ERCC1 Gene on reverting platinum resistance of human lung adenocarcinoma cell line A549/DDP. Method: The siRNAs which targeted the same sequences of ERCC1 gene were designed and synthesized.Human lung adenocarcinoma cell line A549/DDP was cultured and tranfected with siRNAs by Lipofectin2000.Experimental cell grouping:A549/DDP(Control)

Brucea-treated group

siRNA-treated group

Brucea and siRNA treated group. ERCC1mRNA was assayed by RT-PCT

and the protein expression was detected by Western blotting.The efficiency of A549/DDP to cisplatin was determined by MTT method. Result: The expression of ERCC1mRNA and protein decreased significantly after transfection of siRNAs

B. javanica oil and B. javanica oil+siRNAs.The efficiency of A549/DDP to cisplatin reversed significantly. The drug-resistant multiple droped back to 9.72

8.89

7.59

6.83.The reversing effect increased significantly by siRNAs combined with B. javanica oil. Conclusion: Both siRNAs and B. javanica oil can reverse platinum resistance of human lung adenocarcinoma cell line A549/DDP.The inhibition effect increases significantly by siRNAs combined with B. javanica oil emulsion.