肿瘤相关糖类抗原Tn在子宫内膜癌中异常表达及其生物学意义

Aberrant expression of Tn antigen in patients with endometrial carcinoma and its biological significance

目的 探索肿瘤相关糖类抗原Tn在子宫内膜癌病人中的表达及其生物学意义。方法 首先采用免疫组化染色(IHC)技术检测人子宫内膜癌组织、子宫内膜非典型增生组织和正常子宫内膜组织的Tn抗原表达状况;然后采用CRISPR/Cas9技术特异性敲除人子宫内膜癌细胞(Ishikawa、HEC-1B)的Cosmc基因以诱导Tn抗原表达;应用流式细胞技术检测Tn抗原的表达,并采用Transwell实验检测Tn抗原异常表达对子宫内膜癌细胞迁移和侵袭能力的影响;最后采用western blot检测Tn抗原表达是否影响子宫内膜癌细胞上皮-间质转化(epithelial-mesenchymal transition, EMT)。结果 免疫组化染色结果显示,正常子宫内膜组织中不表达Tn抗原,但子宫内膜非典型增生组织中可检测到低表达的Tn抗原,在子宫内膜癌组织中Tn抗原呈高表达,主要定位在细胞膜和胞浆;western blot结果显示敲除人子宫内膜癌细胞的Cosmc可诱导Tn抗原阳性表达;体外细胞实验显示Tn抗原明显促进肿瘤细胞的迁移和侵袭能力。此外,Tn抗原表达显著激活了EMT信号通路,表现为上皮相关蛋白E-cadherin表达水平下调和间质相关蛋白N-cadherin和Vimentin表达水平上调。结论 肿瘤相关糖类抗原Tn在子宫内膜癌中异常高表达,与肿瘤侵袭转移有相关性;Tn抗原表达可促进子宫内膜癌细胞迁移和侵袭,其机制可能激活EMT信号通路有关。

Objective To detect the expression of Tn antigen in patients with endometrial carcinoma and to investigate its biological significance.Methods We first used immunohistochemical staining to detect the expression and localization of Tn antigen in human endometrial carcinoma tissues,atypical endometrial tissues,and normal endometrial tissues.We then used the CRISPR/Cas9editing system to deplete the Cosmc gene in two human endometrial carcinoma cell lines(Ishikawa,HEC-1B)to forcedly induce Tn antigen expression.The Tn antigen expression was determined by flow cytometric analysis.Transwell assays were performed to measure cell migration and invasion.Finally,we used western blot analysis to assess the effects of Tn expression on induction of the epithelial-mesenchymal transition(EMT)signaling pathway in cells.Results It showed that Tn antigen was not detected in normal endometrial tissues but lowly expressed in atypical endometrial hyperplasia and highly expressed in endometrial carcinoma tissues.Depletion of Cosmc forcedly induced the expression of Tn antigen in two cancer cell lines and subsequently promoted cell migration and invasion capabilities.In addition,the EMT program was significantly activated following Tn antigen expression,demonstrated by a down-regulation of E-cadherin and an up-regulation of Vimentin and N-cadherin.Conclusion Tn antigen is highly expressed in human endometrial carcinoma and may contribute to cancer cell migration and invasion through activation of the EMT signaling pathway.