Abstract: Objective：Using siRNA（Small interference RNA） technology to silence LRP(lung resistance protein),and to explore whether this may improve the sensitivity to taxol in Lung Adenocarcinoma. Method: For building the cell line which is taxol -resistance, the graduated concentrations of taxol was added to the cells. Then the siRNA technology to silence LRP gene in A549/TXL20 was performed.MTT detected the IC50 of taxol after A549/TXL20 transfection. Using qPCR to test the level of expression of LRP mRNA .Western blot detected the protein of LRP in the cells. To build the nude mice model of transplanted tumor by injecting A549/TXL cell into the armpit of nude mice, then detected the function of siRNA aimed at LRP to the resistance of drug in human lung adenocarcinoma cell line, A549/TXL20. Results :After siRNA silencing LRP gene in A549/TXL20 cell line , compared the blank group and the negative group, the control group showed the inhibiting effect of LRP mRNA and protein expression (P<0.01).MTT showed that the sensitivity for taxol in A549/TXL20 was raised.A549/TXL20 cell line after interference could not grow to form transplanted tumors（P<0.01）. Conculsion: siRNA could silence the LRP in A549/TXL20 which is the gene related to Lung Adenocarcinoma resistant drugs, and raise the sensitivity of the cell line to taxol.

Key words: human lung adenocarcinoma, taxol, LRP, siRNA