全反式维甲酸联合阿司匹林对体外抑制肺腺癌细胞株A549增殖和促凋亡的作用及其机制

目的：观察全反式维甲酸（ATRA）联合阿司匹林（ASA）体外抑制肺癌A549细胞增殖，促凋亡作用和机制。方法：体外培养人肺腺癌A549细胞，5，10 μmol·L^-1的ATRA单独及分别联合5，10 μmol·L^-1的ASA进行干预48 h、72 h后，MTT法检测细胞增殖抑制率；TUNEL法观测药物作用48 h后细胞凋亡状态；RT-PCR法检测药物作用后肺腺癌A549细胞COX-2 mRNA的表达；Western blot法检测凋亡相关因子Bax、Bcl-2、COX-2和caspase-3蛋白的表达。结果： ATRA与ASA联用对A549增殖具有协同作用；TUNEL法结果显示ATRA可诱导A549细胞凋亡，与ASA联用凋亡率显著升高（P<0.05）；RT-PCR显示A579细胞中COX-2 mRNA呈现高表达状态，ASA可下调COX-2表达，ATRA无此作用；Western blot结果显示ATRA和ASA协同作用使A549细胞中Bcl-2、COX-2蛋白表达受到抑制，Bax蛋白表达增加，Bcl-2/Bax值降低，对凋亡通路的影响大于单药作用（P<0.05）。结论： ASA联合ATRA可协同抑制肺腺癌细胞A549的增殖及以及促进其发生凋亡，其作用机制可能是ASA通过抑制COX-2蛋白表达，与ATRA共同通过Bcl/caspase通路诱导肿瘤凋亡实现的。

Influence of all trans retinoic acid and aspirin on proliferation and apoptosis of lung adenocarcinoma cell line A549 in vitro

OBJECTIVE To observe the effects of all trans retinoic acid (ATRA) combined with aspirin (ASA) on the proliferation, apoptosis and of lung cancer A549 cells in vitro.METHODS The proliferation of human lung adenocarcinoma A549 cells was detected by MTT assay after 48 h and 72 h incubation with different concentrations of drugs. TUNEL method was used to observe the apoptotic state after 48 h. The expression of COX-2 mRNA in lung adenocarcinoma A549 cells was detected by RT-PCR. Western blot was used to detect the expressions of Bax, Bcl-2, COX-2 and caspase-3 proteins.RESULTS ATRA and ASA had synergistic effects on A549 proliferation. The TUNEL showed that apoptosis of A549 cells was significantly increased with ATRA combined with ASA (P<0.05). RT-PCR showed that COX-2 mRNA was highly expressed in A579 cells, and ASA could down regulate COX-2 expression. Western result showed that ATRA combined with ASA had more influence on apoptosis pathway than ATRA alone. The mechanism might be correlated with synergistically down regulated expression of COX-2, Bcl-2 and caspase-3 protein as well as up regulated expression of Bax protein.CONCLUSION ASA aspirin combined with all trans retinoic acid synergistically inhibits the proliferation of lung adenocarcinoma cell A549 and promotes cell apoptosis. The mechanism is correlated with ASA and ATRA synergistically induced cell apoptosis by Bcl/caspase pathway, which may be achieved by affecting COX-2 expression of ASA.