SSBP1在肺腺癌中的表达及对A549细胞增殖的影响

The expression of SSBP1 in lung adenocarcinoma and effects of SSBP1 on proliferation in A549 cells

目的探讨线粒体单链DNA结合蛋白1(SSBP1)在肺腺癌中的表达及其对肺癌A549细胞的增殖影响的作用机制。方法通过TCGA数据库下载肺腺癌和肺鳞癌的临床信息和SSBP1 mRNA的表达水平。构建SSBP1基因敲低的慢病毒载体,通过慢病毒感染建立稳定SSBP1基因敲低的A549细胞系,细胞分成SSBP1敲低组和阴性对照组。采用CCK8和平板克隆实验检测其对细胞增殖和克隆形成的影响;免疫印迹法检测对Akt磷酸化的影响。结果TCGA数据库结果显示,与癌旁组织相比,SSBP1 mRNA在肺腺癌组织中表达增高,差异有统计学意义(t=6.25,P<0.01),SSBP1 mRNA的表达水平随着肺腺癌分期的增加而增加,差异有统计学意义(F=7.52,P<0.01)。高表达SSBP1 mRNA的肺腺癌患者总生存时间及无病生存率均较低表达者差(P值均<0.01)。SSBP1敲低组A549细胞增殖和克隆形成能力均低于阴性对照组,差异有统计学意义(t=13.91、15.19,P值均<0.01);SSBP1敲低组A549细胞的Akt磷酸化水平低于阴性对照组,差异有统计学意义(t=17.88,P=0.003)。SSBP1 mRNA与Ki67 mRNA在肺腺癌组织中具有明显的正相关性(r=0.39,P<0.01)。结论SSBP1可能作为肺腺癌患者预后的分子标志物,SSBP1可能通过调控Akt通路促进肺癌细胞增殖。

Objective To investigate the expression of mitochondrial single-strand binding protein 1(SSBP1)in lung cancer and effect of SSBP1 on the proliferation and its mechanism in A549 cells.Methods The data set of patients with lung adenocarcinoma and lung squamous cell carcinoma was downloaded from TCGA,and SSBP1 gene expression profile and clinical information were obtained.A549 cell line with SSBP1 stable knockdown for investigating the function of SSBP1 in lung cancer was established.Cells were divided into two groups:SSBP1 knockdown group and negative control group.The effects of SSBP1 knockdown on the proliferation of A549 cells were detected by CCK8 assay and colony formation assays.The expression of Akt was detected by Western blot.Results Compared with adjacent tissues,SSBP1 mRNA was highly expressed in lung adenocarcinoma tissues using data sets from TCGA,the difference was statistically significant(t=6.25,P<0.01).The expression level of SSBP1 mRNA increased with the increase of lung adenocarcinoma stage,and the difference was statistically significant(F=7.52,P<0.01).Patients with high expression of SSBP1 mRNA in lung adenocarcinoma had lower overall survival time and disease-free survival rate than those with low expression(both P<0.01).The proliferation and clonogenesis of A549 cells in SSBP1 knockdown group were lower than those in the negative control group,the difference was statistically significant(t=13.91,15.19,both P<0.01).The phosphorylation level of Akt in A549 cells in SSBP1 knockdown group was lower than that in the negative control group,and the difference was statistically significant(t=17.88,P=0.003).Our results showed that there was a significant positive correlation between the expression of SSBP1 mRNA and Ki67 mRNA in lung adenocarcinoma using data sets from TCGA(r=0.39,P<0.01).Conclusions SSBP1 could serve as a valuable predictive factor for lung adenocarcinoma patients.SSBP1 promotes the proliferation of cells through the Akt pathway in lung adenocarcinoma.