长链非编码RNA ZNF667-AS1在食管鳞状细胞癌组织中的表达及其DNA甲基化状态的研究

Expression and DNA Methylation Status of Long Non-coding RNA ZNF667-AS1 in Esophageal Squamous Cell Carcinoma Tissues

目的检测长链非编码RNA ZNF667-AS1在食管鳞状细胞癌(esophageal squamous cell carcinoma,ESCC)中的表达及甲基化状态。方法应用qPCR和MSP法检测DNA甲基化转移酶抑制剂5-Aza-dC处理前后食管癌细胞系(Kyse170、Eca109、TE1和TE13)、ESCC及相应癌旁正常组织中ZNF667-AS1基因的表达,及其CpG岛三个区域的甲基化状态。结果在5-Aza-dC处理后的四株细胞系中,ZNF667-AS1基因的表达均增高,且其CpG岛三个区域甲基化程度均降低。ZNF667-AS1基因在ESCC组织中的表达显著低于相应癌旁正常组织,且该基因CpG岛远端启动子区及第一外显子区甲基化率在ESCC与相应癌旁正常组织中的差异均具有统计学意义(均P<0.05)。ESCC组织中CpG岛近端启动子区甲基化率显著高于相应癌旁正常组织,并与组织分化程度、TNM分期密切相关,ZNF667-AS1基因CpG岛近端启动子区发生甲基化的ESCC组织中,低表达例数高于高表达例数,差异具有统计学意义。结论 ZNF667-AS1基因在食管癌细胞系和ESCC组织中的低表达与ESCC的发生发展密切相关,且其近端启动子区的高甲基化状态可能是导致其表达沉默的机制之一。

Objective To detect the expression and methylation status of long non-coding RNA ZNF667-AS1 in esophageal squamous cell carcinoma(ESCC)tissues.Methods qPCR and MSP methods were respectively applied to detect the expression and methylation status of ZNF667-AS1 in esophageal cancer cell lines(Kyse170,Eca109,TE1,TE13),ESCC and corresponding noncancerous tissues before or after DNA methyltransferase inhibitor 5-Aza-dC treatment.Results After treated with 5-Aza-dC,ZNF667-AS1 performed higher expression in the four esophageal cancer cell lines,and the methylation status of ZNF667-AS1 were decreased.The expression of ZNF667-AS1 in ESCC tissues was significantly lower than that in the corresponding normal tissues,and the methylation frequency of ZNF667-AS1 distal and exon1 regions CpG islands were all significantly different(P<0.05).The methylation frequency of ZNF667-AS1 proximal promoter region CpG island in ESCC tissues was significantly higher than that in the corresponding normal tissues,and closely correlated with pathological differentiation and TNM stages;the methylation frequency in the low ZNF667-AS1 expression group was significantly higher than that in the high ZNF667-AS1 expression group.Conclusion The low expression of ZNF667-AS1 is closely related to the occurrence and development of ESCC,and its proximal promoter region methylation may be one of the mechanisms of ZNF667-AS1 silence.