TONSL在食管癌中的表达及其影响食管鳞癌细胞增殖的机制

The expression of tonsoku-like DNA repair protein in esophageal carcinoma and its effect on the proliferation of esophageal squamous cell carcinoma

目的:探讨tonsoku样DNA修复蛋白(TONSL)在食管癌组织中的表达及其对食管鳞癌细胞增殖的影响及机制。方法:利用cBioPortal、GEPIA和PRIDE等数据库分析在食管癌组织中,TONSL基因组拷贝数及其转录和翻译水平的变化。通过免疫组织化学实验检测TONSL蛋白在食管鳞癌和正常食管组织中的表达。利用siRNA干扰构建TONSL瞬时敲降食管鳞癌细胞模型,并采用集落形成实验和EdU实验检测TONSL敲降对食管鳞癌细胞增殖能力的影响。Western blot检测TONSL敲降后食管鳞癌细胞中DNA损伤修复相关标志蛋白ATM丝氨酸/苏氨酸激酶(ATM)和检查点激酶2(CHK2)及其磷酸化激活水平的变化。结果:与正常食管组织比较,食管癌基因组、转录组和蛋白质组的数据库分析结果显示,TONSL在食管癌组织中拷贝数增加表达,其mRNA和蛋白质表达水平在食管癌组织中均上调(P<0.05),且TONSL高表达与食管癌患者不良预后相关(P<0.05);免疫组织化学验证结果也表明TONSL蛋白在食管鳞癌组织中表达上调(P<0.001)。集落形成实验和EdU实验结果显示,与对照组相比,TONSL敲降后食管鳞癌细胞增殖能力减弱(P<0.05),并且在敲降TONSL后,食管鳞癌细胞DNA损伤修复相关蛋白ATM和CHK2的磷酸化水平均上调(均为P<0.05)。结论:TONSL在食管鳞癌中表达上调,并通过参与食管鳞癌细胞DNA损伤修复促进食管鳞癌细胞增殖。

OBJECTIVE:To investigate the expression of tonsoku-like DNA repair protein(TONSL)in esophageal carcinoma and its effect and mechanism on the proliferation of esophageal squamous cell carcinoma.METHODS:Databases such as cBioPortal,GEPIA and PRIDE were used to analyze changes in TONSL genome copy number and its transcription and translation levels in esophageal cancer.The expression of TONSL in esophageal squamous cell carcinoma and normal esophageal tissues was detected by immunohistochemistry.Small interfering RNA(siRNA)was used to construct a TONSL knockdown esophageal squamous cell model.The effect of TONSL knockdown on the proliferation of esophageal squamous cell carcinoma cells was studied by colony formation assay and EdU assay,while the changes of phosphorylated activation levels of ATM serine/threonine kinase(ATM)and checkpoint kinase 2(CHK2),two DNA damage repair related marker proteins in esophageal squamous cell carcinoma cells was detected by Western blot.RESULTS:Compared with normal esophageal tissue,copy number amplification of TONSL was common in esophageal cancer,and its mRNA and protein levels in esophageal cancer were up-regulated compared with those in normal esophageal tissues(P<0.05),and high TONSL expression was associated with poor prognosis of patients with esophageal carcinoma(P<0.05).The results of immunohistochemistry also showed that TONSL was up-regulated in esophageal squamous cell carcinoma.The results of colony formation assay and EdU assay showed that knockdown of TONSL inhibited the proliferation of esophageal squamous cell carcinoma cells(P<0.05).Moreover,TONSL knockdown induced up-regulation of the phosphorylation of ATM serine/threonine kinase(ATM)and checkpoint kinase 2(CHK2)in esophageal squamous cell carcinoma cells.CONCLUSION:TONSL was up-regulated in esophageal squamous cell carcinoma and promoted the proliferation of esophageal squamous cell carcinoma by participating in DNA damage repair.