TFF1甲基化状态对食管鳞状细胞癌TE1和TE13细胞凋亡的影响

目的 观察食管鳞状细胞癌（esophageal squamous cell carcinoma, ESCC）及其周围组织中三叶因子家族1（trefoil factor family, TFF1）的表达，分析TFF1的甲基化状态对细胞凋亡的影响。方法 收集43例ESCC患者和36名健康对照个体的食管组织标本，利用免疫组化染色观察TFF1在正常食管组织、ESCC及其周围组织中的表达情况；采用MSP法检测TE1和TE13细胞中TFF1启动子甲基化状态，qRT - PCR法检测TE1和TE13细胞去甲基化前后TFF1 mRNA表达水平，western blot检测TE1和TE13细胞去甲基化前后TFF1和caspase - 3蛋白的表达。结果 （1）在肺腺癌阳性对照和正常食管腺上皮组织中，TFF1呈阳性表达，而在ESCC或肿瘤周围组织中未观察到着色。（2）处理前，TE1和TE13细胞TFF1呈高甲基化状态；处理后，两组细胞TFF1甲基化程度明显降低，且TE13低于TE1。（3）未处理前，TE1和TE13细胞TFF1 mRNA表达水平较低，处理后，两组细胞中TFF1 mRNA的表达水平明显升高，且TE13高于TE1（P＜0.001）。（4）经西他滨处理后，两组细胞TFF1蛋白和激活型caspase - 3蛋白表达明显升高（P＜0.01）。结论 （1）TFF1在ESCC及其周围组织中的表达缺失，与TFF1高甲基化状态有关；（2）TFF1甲基化下调后，TE1和TE13细胞中TFF1 mRNA和TFF1蛋白的表达均增加，通过激活caspase凋亡通路，促使细胞凋亡增加，在ESCC中起着肿瘤抑制剂的作用；（3）TFF1可作为ESCC早期诊断的生物标志物和临床治疗的潜在靶目标。

Effect of TFF1 methylation status on apoptosis of esophageal squamous cell carcinoma TE1 and TE13 cells

Abstract: Objective To observe the expression of trefoil factor family 1 (TFF1) in esophageal squamous cell carcinoma (ESCC) and its surrounding tissues and the effect of TFF1 methylation status on apoptosis. Methods Esophageal specimens from 43 ESCC patients and 36 healthy controls were collected. Immunohistochemical staining was used to observe the expression of TFF1 in normal esophageal tissue, ESCC and its surrounding tissues. MSP method was used to detect the TFF1promoter methylation status in TE1 and TE13 cells. The qRT-PCR method was used to detect TFF1 mRNA expression levels before and after demethylation of TE1 and TE13 cells. Western blot was used to detect the expression of TFF1 and Caspase3 protein before and after demethylation in TE1 and TE13 cells. Results (1) TFF1 was positively expressed in lung adenocarcinoma positive controls and normal esophageal glandular epithelial tissues, but no staining was observed in ESCC or tumor surrounding tissues. (2) TFF1 was hypermethylated in TE1 and TE13 cells before treatment. After treatment, it was significantly reduced in two groups, and the TE13 was lower than the TE1. (3) The expression of TFF1 mRNA was lower inTE1 and TE13 cells before treatment, but it was significantly increased after treatment, and the TE13 was higher than theTE1 (P <0.001). (4) The expression of TFF1 protein and activated caspase -3 protein were significantly increased aftertreatment with sitagamibine in two groups (P<0.01). Conclusion The lack of expression of TFF1 in ESCC and its surrounding tissues is related to the TFF1 hypermethylation state. After TFF1 methylation is down -regulated, the expression of TFF1mRNA and TFF1 protein are increased in TE1 and TE13 cells, and apoptosis is increased by activating the caspase apoptotic pathway. It plays a role as a tumor suppressor in ESCC. TFF1 can be used as a biomarker for early ESCC diagnosis and a potential target for clinical treatment.