类泛素蛋白FAT10在食管癌中的表达及生物学作用

目的:探讨类泛素蛋白FAT10的异常表达在食管癌（esophageal carcinoma，ECA）进展中的作用机制。方法:采用RT-PCR和Western blot法检测FAT10在30例ECA标本中的mRNA和蛋白表达水平。siRNA技术干扰食管癌细胞ECA-109中FAT10表达后，MTT检测细胞增殖，流式细胞术检测ECA-109细胞周期和细胞凋亡的变化，Western blot检测Akt/GSK3β信号通路的变化。结果:RT-PCR和Western blot结果显示，FAT10在食管癌组织中的表达水平较癌旁组织显著上调（P<0.05）。siRNA技术干扰ECA-109细胞中FAT10表达后，ECA-109细胞生长速度明显下降（P<0.05）。流式细胞术结果显示FAT10 siRNA干扰ECA-109细胞48h时，对细胞周期分布无明显影响（P>0.05）。但FAT10表达下调有促凋亡作用，与对照组相比，干扰组的细胞凋亡率显著升高，差异有统计学意义（P<0.05）。Western blot检测到ECA-109细胞中Akt和GSK3β的磷酸化水平都明显下降。结论:FAT10基因在食管癌组织中表达上调，下调FAT10的表达能够抑制食管癌进展，机制可能是通过诱导肿瘤细胞凋亡来实现的。

Expression of FAT10 gene in esophageal carcinoma and its biological functions

Objective:To explore the role and mechanism of FAT10 abnormal expression in esophageal carcinoma (ECA).Methods:The mRNA and protein level of FAT10 in human ECA tissues was detected by real-time RT-PCR and Western blot.After siRNA was successfully performed in esophageal carcinoma cell line ECA-109 cells to down-regulate FAT10 expression, cell proliferation assay was performed by MTT method.The cell cycle and apoptosis of HCCLM3 cells was assayed by FACS.The expression of Akt，phospho-Akt and phospho-GSK3β were detected by Western blot.Results:FAT10 gene was overexpressed in human ECA tissues compared with the matched adjacent normal tissues.After siRNA was successfully performed in ECA-109 cells to down-regulate FAT10 expression, the growth speed in FAT10 siRNA groups was significantly decreased compared with control groups (P<0.05).Compared with control group，the distribution of cell cycle was not changed but apopotic cells were significantly increased in FAT10 siRNA groups.After knocked down FAT10 in ECA-109 cell，the expression of phospho-Akt and phospho-GSK3β was significantly down-regulated.Conclusion:FAT10 was significantly increased in esophageal carcinoma.Down-regulating FAT10 expression induced apoptosis of ECA cells via deactivating Akt/GSK3β signaling pathway.