Activation of TLR9 affected chemotherapeutic sensitivity of doctaxel in human non-small cell lung cancer in vitro / 中国病理生理杂志

ABSTRACT

AIM:To probe whether CpG oligodeoxyribonucleotides 7909 (CpG ODN7909) combined with Toll like receptor (TLR)9 affected the chemotherapeutic sensitivity of doctaxel (DOC) in human lung cancer A549 and H520 cell lines.METHODS:Sequences of TLR9 siRNAs were designed.A549 and H520 cells were transfected with TLR9 siR-NA by lipofectamine.The expression of TLR9 was detected by Western blot .The cell activity was measured by CCK-8 as-say.The experiments were divided into blank control group , control siRNA group and TLR9 siRNA interference group.The cell cycle distribution and cell apoptosis were analyzed by flow cytometry .The expression of P38 and Bax was determined by Western blot .The cells in each group were exposed to CpG ODN 7909 and/or DOC.RESULTS: In A549 cells and H520 cells, CpG ODN7909 alone had no obvious effect on the cell activity , G2/M phase arrest and apoptosis , but in-creased the protein expression of P 38 and Bax ( P<0.01) .In addition, there was no significant changes of the above inde-xes in CpG ODN7909 treated-TLR9 siRNA group was observed .DOC alone significantly inhibited the cell activity , higher the G2/M phase fractions, apoptotic rates and Bax expression (P<0.01), but didn’t affect the expression of P38 in all 3 groups.Compared with the cells treated with DOC alone , the cells treated with CpG ODN7909 combined with DOC exhibi-ted lower cell activity, higher G2/M phase fractions, apoptosis rates and more Bax expression (P<0.01), showed no sig-nificant change of P38 expression.In addition, there was no significant change of the above indexes in CpG ODN 7909 com-bined with DOC treated-TLR9 siRNA group was observed .CONCLUSION:CpG ODN7909 may enhance the chemothera-peutic sensitivity of DOC in human lung cancer cells by combining with TLR 9.The mechanism might be related to enhan-cing the inhibitory effect and apoptosis of DOC on the cell activity in vitro, arresting the cells at G 2/M phase of the cells .