目的：探讨穿膜蛋白125（transmembrane protein125，TMEM125）在肺腺癌组织与A549细胞中的表达，以及影响细胞的增殖和侵袭能力的分子机制。方法：从癌症基因组图谱（the cancer genome atlas，TCGA）数据库收集肺腺癌数据包，下载临床信息及基因表达谱数据。分析 TMEM125在肺腺癌组织中的表达及其与患者总生存期的相关性。构建 TMEM125过表达 A549细胞株，以CCK-8法、细胞划痕实验检测TMEM125过表达对肿瘤细胞的增殖和迁移能力的影响；流式细胞术检测TMEM125过表达对A549细胞的细胞周期和凋亡的影响。WB检测TMEM125过表达对下游NF-κB信号通路、凋亡蛋白的影响；免疫共沉淀法（co-immunoprecipitation，Co-IP）检 测 TMEM125 与 NF- κB 抑 制 因 子 结 合 Ras 样 2（NF- κB inhibitor interacting Ras-like 2，NKIRAS2）的相互作用。利用TNFα（10 ng/ml）处理TMEM125过表达A549细胞，CKK-8、流式细胞术及WB检测其对细胞增殖、凋亡以及NF-κB信号通路相关蛋白表达的影响。去甲基化试剂地西他滨处理A549细胞，qPCR和WB检测TMEM125基因和蛋白的表达。结果：TMEM125 mRNA在肺腺癌组织中表达水平显著低于正常组织（P<0.001），启动子甲基化水平显著高于正常组织（P<0.001），并且低、中表达患者总生存期显著低于高表达患者（P<0.001）。过表达TMEM125抑制了A549细胞的增殖和迁移（P<0.01），增加细胞 G2/M 期，促进细胞凋亡（P<0.01）；过表达 TMEM125 与 NKIRAS2 相互作用，显著抑制 NF-κB 的活性（P<0.01）；地西他滨处理 A549 细胞可促进 TMEM125 表达并且抑制细胞增殖（P<0.01）。结论：启动子高甲基化水平降低了TMEM125基因表达，导致其抑制NF-κB活性功能和抑制细胞增殖的作用下降，并且降低了细胞对地西他滨的敏感性。

Objective: To explore the expression of transmembrane protein 125(TMEM125) in lung adenocarcinoma (LUAD) tissues and A549 cells, and the molecular mechanism that affects the proliferation and invasion of A549 cells. Methods: Collected and downloaded the lung adenocarcinoma clinical information and gene expression profile data from The Cancer Genome Atlas (TCGA) database, and analyzed the correlation between the expression of TMEM125 in lung adenocarcinoma and the overall survival of patients.Constructed TMEM125 overexpressing A549 cell line, detected the effect of TMEM125 overexpression on the proliferation and migration of A549 cells by CCK-8 assay and Wound healing assay, and detected the effect of TMEM125 overexpression on the cell cycle and apoptosis of A549 cells by using flow cytometry. WB was used to detect the effect of TMEM125 overexpression on downstream NF- κB signaling pathways and apoptotic proteins. Co-immunoprecipitation (Co-IP) was used to detect the interaction between TMEM125 and NF-κB inhibitor interacting Ras-like 2 (NKIRAS2). TMEM125 overexpressing cells was treated with TNFα（10 ng/ml）and then CCK-8 assay, flow cytometry and WB were used to detect its effects on cell proliferation, apoptosis and NF- κB signaling pathway proteins. A549 cells were treated with demethylation reagent decitabine, and the expression of TMEM125 gene and protein was detected by qPCR and WB. Results: The expression level of TMEM125 mRNA in LUAD tissue was significantly lower than that in normal tissues (P<0.001), the promoter methylation level was significantly higher than that in normal tissues (P<0.001), and the overall survival of patients with low and medium expression was significantly lower than that of patients with high expression (P<0.001).Overexpression of TMEM125 inhibited the proliferation and migration of A549 cells (P<0.01), increased cell G2/M phase and promoted cell apoptosis (P<0.01). Overexpression of TMEM125 could interact with NKIRAS2 and inhibit the activity of NF- ΚB (P<0.01).Treatment of A549 cells with decitabine could promote the expression of TMEM125 and inhibit cell proliferation (P<0.01).Conclusion:Promoter hypermethylation inhibits TMEM125 gene expression, leading to a decline in its function of inhibiting NF-κB activity and inhibiting cell proliferation and therefore reduce the sensitivity to decitabine, and resulting in the decreased sensitivity to decitabine.

海南省卫生健康行业科研资助项目（No.19A200014）