辛伐他汀对非小细胞肺癌细胞增殖和免疫逃逸的影响

Effects of simvastatin on cell proliferation and immune escape of non-small cell lung cancer

目的观察辛伐他汀对非小细胞肺癌(NSCLC)细胞增殖和免疫逃逸的影响,并探讨其机制。方法用改进MTT法检测不同浓度辛伐他汀、RhoA siRNA处理后A549细胞的增殖情况;用Real-time RTPCR检测抗免疫逃逸相关因子即主要组织相容性复合体Ⅰ类(MHCⅠ,又称HLA-A)和肽转运蛋白(TAP1)的基因表达;用RhoA活性测定法观察RhoA活性变化;用Lipofectamine 2000转染siRNA。结果辛伐他汀能浓度依赖性(10～30μmol/L)地抑制A549细胞增殖,增强HLA-A和TAP1基因表达,抑制RhoA活性(P<0.05或<0.01)。用0.1μmol/L RhoA siRNA抑制RhoA活性后,也能显著抑制A549细胞增殖,增加HLA-A和TAP1基因表达(P<0.01)。但RhoA siRNA联合应用辛伐他汀不能产生协同效应,而与单用RhoA siRNA的作用相似(P>0.05)。结论辛伐他汀主要依赖于抑制A549细胞的RhoA活性,从而增加HLA-A和TAP1表达,减少免疫逃逸和细胞增殖。

Objective To evaluate the effects of simvastatin on cell proliferation and immune escape of human non-small cell lung cancer（NSCLC） as well as the underlying mechanisms.Methods Cell proliferation was determined using a modified MTT assay after the treatment with different concentrations of simvastatin,or RhoA siRNA in A549 cells.The gene expression of anti-immune escape factor,major histocompatibility complex class Ⅰ（MHC Ⅰ,also known as HLA-A） and peptide transporter protein（TAP1） were detected by real-time RT-PCR.The change of RhoA activity was measured by a microplate reader in A549 cells treated with simvastatin,or RhoA siRNA.SiRNA transfection was done using lipofectamine 2000.Results Simvastatin（10～30 μmol / L） significantly reduced the proliferation,enhanced gene expression of HLA-A and TAP1 and inhibited RhoA activity of A549 cells in concentration-dependent manner（P ＆lt; 0.05 or P ＆lt; 0.01）.Moreover,inhibition of RhoA activity with 0.1 μmol / L RhoA siRNA also resulted in a substantial inhibition of proliferation and increased gene expression of HLA-A and TAP1 of 549 cells（P ＆lt; 0.01）.However,combination treatment of RhoA siRNA and simvastatin exerted no synergistic effects in 549 cells compared with the specific siRNA treatment alone（P ＆gt; 0.05）.Conclusion Simvastatin can suppress A549 cells proliferation and immune escape primarily through inhibition of RhoA activity and thereby increasing the gene expression of HLA-A and TAP1.