N-myc下游调控基因2蛋白在喉鳞状细胞癌中的表达及对人喉表皮样癌细胞生物学特性的影响

Expression of NDRG2 in laryngeal squamous cell carcinoma and its effects on cellbiological character of Hep-2 cells

目的检测N-myc下游调控基因2(N-myc downstream regulated gene 2,NDRG2)在喉鳞状细胞癌组织中的表达及其人类上皮细胞2型((Human Epithelial cells of type 2)对人喉表皮样癌细胞(Hep-2细胞)侵袭的影响。方法收集西安交通大学第一附属医院2014年1月1日至2017年12月31日接受喉部分切除术的病人,共计41例喉鳞状细胞癌组织及癌旁组织。采用免疫组织化学检测喉鳞状细胞癌组织中NDRG2的表达,χ^2检验分析不同临床病理特征分组中NDRG2阳性率的差异;实时定量聚合酶链式反应及蛋白质印迹法检测喉鳞状细胞癌Hep-2细胞中NDRG2的表达水平;Transwell检测NDRG2对Hep-2细胞侵袭及转移的影响。结果41例喉鳞状细胞癌组织中NDRG2的阳性率明显低于癌旁组织,(χ^2=30.781,P<0.05)TNM III期和IV期及淋巴结转移的喉鳞状细胞癌病人中NDRG2的阳性率低于TNM I期和II期及未发生转移的病人(TNM I和TNM II NDRG2阳性率:37.500%,TNM III和IV NDRG2阳性率:5.882%,χ^2=5.394,P<0.05;无淋巴结转移病人NDRG2阳性率:55.556%,有淋巴结转移病人NDRG2阳性率:15.625,χ^2=6.073,P<0.05)。此外,Hep-2细胞中NDRG2的表达也明显低于正常鼻咽上皮NP-69细胞[Hep-2(1.193±0.053),NP-69(0.238±0.072),t=3.536,P<0.05]。上调Hep-2细胞中NDRG2的表达后,转移[Lv-control(141.328±23.424)个,Lv-NDRG2(54.925±16.825)个,t=4.413,P<0.05]及侵袭[Lv-control(71.782±18.675)个,LvNDRG2(25.931±9.729)个,t=3.757,P<0.05]细胞数目显著降低。结论NDRG2在喉鳞状细胞癌组织及细胞中低表达,并可作为抑癌基因抑制Hep-2细胞增殖、侵袭及转移。

Objective To investigate the expression of N-myc downstream regulated gene 2(NDRG2)in tissues of laryngeal squamous cell carcinoma(LSCC)and its effect on human epithelial cells of type 2(Hep-2)invasion.MethodsA total of 41 cases of laryngeal squamous carcinoma tissues and adjacent tissues who underwent partial laryngectomy in the First Affiliated Hospital of Xi’an Jiaotong University from January 1,2014 to December 31,2017 were collected.Immunohistochemestry(IHC)was performed to detect the expression of NDRG2 in tissues of LSCC,chi-square analysis was performed to analyze the difference of NDRG2 positive rate in different clinicopathologicalfeature groups.Quantitative polymerase chain reaction(QPCR)and western blot(WB)were performed to detect the expression of NDRG2 in Hep-2 cells,and Transwell assays were performed to detect the effects of NDRG2 on cell migration and invasion of Hep-2 cells.ResultsThe positive rates of NDRG2 in tissues of 41 cases of LSCC were lower than that in adjacent tissues(χ^2=30.781,P<0.05).Compared to LSCC patients at TNM I and TNM II stage or without lymph node metastasis,the positive rates of NDRG2 in LSCC patients at TNM III and TNM IV stage or with lymph node metastasis were significantly down-regulated(NDRG2 positive ratesinTNM I andTNM II:37.500%,NDRG2 positive ratesinTNM III andTNM IV:5.882%,χ^2=5.394,P<0.05;NDRG2 positive ratesinpatientswithlymphnodemetastasis:55.556%,NDRG2 positive ratesinpatientswithoutlymphnodemetastasis:15.625%,χ^2=6.073,P<0.05).Furthermore,the expression of NDRG2 was also lower in Hep-2 cells than that in normal nasopharyngeal epithelial NP-69 cells[Hep-2(1.193±0.053),NP-69(0.238±0.072),t=3.536,P<0.05].After upregulating the expression of NDRG2 in Hep-2 cells,the numbers of migratory[Lv-control(141.328±23.424),Lv-NDRG2(54.925±16.825),t=4.413,P<0.05]and invasive[Lv-control(71.782±18.675),Lv-NDRG2(25.931±9.729),t=3.757,P<0.05]cells were significantly reduced.ConclusionNDRG2 is down-regulated in tissues and cells of LSCC.NDRG2 functions as tumor suppressor to inhibit cell migration and invasion of Hep-2 cells.