LINC00467高表达通过抑制AMPK/mTOR通路抑制细胞自噬促进肺腺癌细胞的增殖和转移

High expression of LINC00467 promotes proliferation and metastasis of lung adenocarcinoma cells by suppressing autophagy via inhibiting the AMPK/mTOR pathway

目的探讨LINC00467对肺腺癌增殖和转移的影响及参与细胞自噬的机制。方法体外培养人支气管上皮细胞16HBE和人肺腺癌细胞A549和H1299,A549和H1299细胞经慢病毒shlinc00467和shNC感染、自噬抑制剂3-甲基腺嘌呤(3-MA)和AMPK抑制剂BML-275处理。分别设置shNC组、shlinc00467组、shNC+3-MA组、shlinc00467+3-MA组、shNC+BML-275组和shlinc00467+BML-275组。实时荧光定量PCR检测细胞中LINC00467的表达,TCGA数据分析组织中LINC00467的表达以及对肺腺癌患者生存率和临床分期的影响,克隆形成实验检测细胞增殖情况,Transwell实验测定细胞迁移和侵袭能力,免疫荧光染色检测LC3的表达,Western blotting检测蛋白表达,GSEA富集分析LINC00467与自噬通路的相关性。结果与16HBE细胞相比,LINC00467在A549和H1299细胞中表达增加(P<0.001)。与癌旁组织相比,肺腺癌组织中LINC00467高表达(P<0.001)且随着临床分期增加表达量增加(P<0.05),LINC00467高表达导致患者不良的总体生存率(OS,P=0.049)和第一阶段进展率(FP,P=0.026)。与shNC组相比,shlinc00467感染的A549和H1299细胞中LINC00467表达降低(P<0.001)。与shNC组相比,shlinc00467导致A549和H1299细胞克隆形成数(P<0.01)、迁移细胞数(P<0.001)、侵袭细胞数(P<0.001)减少、p-mTOR/mTOR(P<0.05)及p62(P<0.01)蛋白表达减少;p-AMPK/AMPK(P<0.05)和LC3II/I(P<0.05)增加;GSEA提示了LINC00467对自噬通路的抑制作用(|NES|>1,P<0.05,FDR<0.25)。结论LINC00467能促进肺腺癌细胞增殖和转移,可能是通过抑制AMPK/mTOR信号通路介导的自噬实现的。

Objective To investigate the regulatory effects of LINC00467 on proliferation and metastasis of lung adenocarcinoma cells and the involvement of autophagy in its regulatory mechanism.Methods LINC00467 expression levels in lung adenocarcinoma tissues and their correlation with the patients'survival outcomes were analyzed using data from TCGA database.LINC00467 expression was also examined using qRT-PCR in human bronchial epithelial cells 16HBE and lung adenocarcinoma cell lines A549 and H1299.In A549 and H1299 cells transfected with a short hairpin RNA targeting LINC00467(shLINC00467),the effects of 3-methyladenine(3-MA,an autophagy inhibitor)and BML-275(an AMPK inhibitor)treatment on cell proliferation,migration,and expressions of LC3 and the AMPK/mTOR pathway proteins were tested using colony formation assay,wound-healing and Transwell assays,immunofluorescence staining and Western blotting.GSEA enrichment analysis was conducted to analyze the correlation between LINC00467 and the autophagy pathway.Results The expression level of LINC00467 was significantly higher in lung adenocarcinoma tissues than in the adjacent tissues(P<0.001)and increased progressively with the clinical stage(P<0.05),and its high expression was associated with a poor overall survival(P=0.049)and a high first progression rate(P=0.026)of the patients.LINC00467 expression was also significantly higher in A549 and H1299 cells than in 16HBE cells.In A549 and H1299 cells,LINC00467 knockdown significantly decreased colony-forming,migration and invasion abilities of the cells,lowered p-mTOR/mTOR and p62 expressions,and increased p-AMPK/AMPK expressions and LC3II/I ratio,and these effects were strongly attenuated by application of either 3-MA or BML-275.GSEA analysis suggested an inhibitory effect on LINC00467 on the autophagy pathway(|NES|>1,P<0.05,FDR<0.25).Conclusion High expressions of LINC00467 promote proliferation and metastasis of lung adenocarcinoma cells possibly by inhibiting cell autophagy mediated by the AMPK/mTOR signaling pathway.