Rap1GAP激酶通过AMPK信号通路影响宫颈癌细胞增殖、侵袭及迁移的研究

Rap1GAP affects proliferation,invasion and migration of cervical cancer cells through AMPK signaling pathway

背景肿瘤细胞快速增殖和难以控制的盆腔淋巴结转移是造成晚期宫颈癌患者死亡的主要原因。Rap1 GTP酶激活蛋白(Rap1 GTPase-activating protein,Rap1GAP)低表达与肿瘤细胞增殖、侵袭和患者不良预后相关。目的探讨Rap1GAP对宫颈癌细胞SiHa、C33a增殖、侵袭和迁移的影响及潜在的分子机制。方法从UCSC(https://xenabrowser.net)数据库中下载经统一标准化的泛癌数据集:TCGA TARGET GTEx(PANCAN,N=19131,G=60499),从中提取ENSG00000076864(Rap1GAP)基因在宫颈癌样本中的表达数据,对每一表达值进行log2(x+0.001)变换,得到Rap1GAP基因的表达;采用Western blot检测RAP1GAP在宫颈癌细胞SiHa、C33a和正常宫颈内皮细胞H8中的表达水平,通过慢病毒转染SiHa、C33a细胞分别上调/下调Rap1GAP的表达,根据不同处理分为正常对照组(SiHa、C33a细胞)、空载组(NC-Rap1GAP)、OERap1GAP组(过表达Rap1GAP)和sh-Rap1GAP组(低表达Rap1GAP),并验证细胞转染效率;采用平板克隆实验和Transwell实验分别检测细胞增殖、侵袭和迁移能力;采用Western blot及qRT-PCR检测上调/下调Rap1GAP表达后各组细胞中Rap1GAP、E-cadherin、N-cadherin蛋白及mRNA的表达;采用Western blot检测磷酸化AMPK(p-AMPK)、AMPK蛋白表达水平。结果从数据库观察到Rap1GAP在宫颈癌组织中的表达显著高于其在正常宫颈组织中的表达(P<0.05)。Western blot结果显示,与H8细胞比较,C33a细胞中Rap1GAP蛋白表达增高,SiHa细胞中Rap1GAP蛋白表达降低(P<0.05)。与SiHa组比较,OE-Rap1GAP组细胞集落形成能力、侵袭和迁移能力降低。与C33a组比较,sh-Rap1GAP组细胞集落形成能力、侵袭和迁移能力增强。Western blot及qRT-PCR实验结果表明,与SiHa组比较,OE-Rap1GAP组细胞内Rap1GAP、E-cadherin蛋白及mRNA表达升高,而N-cadherin、p-AMPK蛋白及mRNA表达降低(P<0.01);与C33a组比较,sh-Rap1GAP组细胞内Rap1GAP、E-cadherin蛋白及mRNA表达降低,而N-cadherin、p-AMPK蛋白及mRNA表达升高(P<0.01)。结论Rap1GAP抑制宫颈癌细胞增殖、侵袭和迁移能力,可能与AMPK信号通路有关。

Background Rapid proliferation of tumor cells and uncontrolled pelvic lymph node metastasis are the main causes of death in patients with advanced cervical cancer.Low expression of Rap1 GTPase-activating protein(Rap1GAP)is associated with tumor cell proliferation,invasion and poor prognosis.Objective To investigate the effect of Rap1GAP on the proliferation,invasion and migration of cervical cancer cells SiHa and C33a and its potential molecular mechanism.Methods The standardized pan-cancer dataset were downloaded from UCSC(https://xenabrowser.net/)database.The expression data of ENSG00000076864(Rap1GAP)gene in cervical cancer samples were extracted from TCGA TARGET GTEx(PANCAN,N=19131,G=60499),and log2(x+0.001)transformation was performed for each expression value.Rap1GAP gene expression was obtained.Western blotting was used to detect the expression of RAP1GAP in cervical cancer cells SiHa and C33a and normal cervical endothelial cells H8.The expression of Rap1GAP was up-regulated and down-regulated by lentivirus transfection in SiHa and C33a cells,respectively.According to different treatments,the cells were divided into normal control group(SiHa and C33a cells),no-load group(NC-Rap1GAP),OE-Rap1GAP group(overexpression of Rap1GAP)and sh-Rap1GAP group(low expression of Rap1GAP),and the transfection efficiency was verified.Cell proliferation,invasion and migration were detected by plate cloning assay and Transwell assay,respectively.Western blotting and qRT-PCR were used to detect the protein and mRNA expressions of Rap1GAP,E-cadherin and N-cadherin in each group after up-regulating and down-regulating Rap1GAP expression.Phosphorylated AMPK(p-AMPK)and AMPK protein expression were detected by Western blotting.Results The expression of Rap1GAP in cervical cancer tissues was significantly higher than that in normal cervical tissues(P<0.05).Western blotting showed that compared with H8 cells,the expression of Rap1GAP protein in C33a cells increased,while the expression of Rap1GAP protein in SiHa cells decreased(P<0.05).Compared with SiHa group,the ability of colony formation,invasion and migration of cells in OE-Rap1GAP group were decreased.Compared with C33a group,the colony formation ability,invasion and migration ability of sh-Rap1GAP group were enhanced.The results of Western blotting and qRT-PCR showed that the protein and mRNA expressions of Rap1GAP and E-cadherin in the OE-Rap1GAP group increased compared with those in the SiHa group.The protein and mRNA expressions of N-cadherin and p-AMPK were significantly decreased(P<0.01).Compared with C33a group,the protein and mRNA expressions of Rap1GAP and E-cadherin in sh-Rap1GAP group were decreased,while the protein and mRNA expressions of N-cadherin and p-AMPK were increased(P<0.01).Conclusion Rap1GAP inhibits the proliferation,invasion and migration of cervical cancer cells,which may be related to AMPK signaling pathway.