Sestrin2在鼻咽癌中的表达及其生物学功能

Expression and Biological Functions of Sestrin2 in Nasopharyngeal Carcinoma

目的探讨Sestrin2在鼻咽癌组织和细胞中的表达及其生物学功能。方法收集46例鼻咽癌患者病理活检组织,免疫组织化学法检测Sestrin2在鼻咽癌及癌旁组织中的表达。利用pcDNA3.1/Sestrin2转染鼻咽癌CNE-1细胞,RT-PCR和Westernblot法验证转染效率。CCK-8和流式细胞术检测Sestrin2过表达对鼻咽癌细胞增殖和凋亡的影响。Western blot法检测Sestrin2过表达对腺苷酸激活蛋白激酶(AMPK)和哺乳动物雷帕霉素靶蛋白(mTOR)表达的影响。结果鼻咽癌组织中Sestrin2的表达水平明显低于癌旁正常组织,且Sestrin2的低表达与TNM分期和淋巴结转移显著相关(P<0.05)。与未处理组和阴性对照组相比,转染组Sestrin2 mRNA和蛋白水平显著升高(P<0.05),细胞增殖能力明显下降,细胞凋亡水平显著升高(P<0.05)。Sestrin2转染组细胞AMPK磷酸化水平升高,mTOR磷酸化水平降低(P<0.05)。结论 Sestrin2在鼻咽癌中低表达,且Sestrin2过表达能显著降低鼻咽癌细胞增殖能力,促进鼻咽癌细胞凋亡,其机制与AMPK和mTOR信号通路有关。

Objective To explore the expression and biological functions of Sestrin2 in nasopharyngeal carcinoma. Methods We collected 46 cases of nasopharyngeal carcinoma tissues. The Sestrin2 expression in carcinoma and para-carcinoma tissues were detected by immunohistochemical analysis. The nasopharyngeal carcinoma CNE-1 cells were transfected by pcDNA3.1/Sestrin2, and then the expression levels of Sestrin2 were detected by RT-PCR and Western blot. Meanwhile, the effects of Sestrin2 overexpression on cell proliferation and apoptosis were detected by CCK-8 and flow cytometry. Moreover, the effects of Sestrin2 overexpression on the expressions of AMPK and mTOR were detected by Western blot. Results The expression of Sestrin2 in nasopharyngeal carcinoma tissues were significantly lower than those in adjacent mucous membrane tissues(P<0.05). The low expression of Sestrin2 was significantly related with TNM staging and lymph node metastasis(P<0.05). Meanwhile, the expression levels of Sestrin2 in nasopharyngeal carcinoma cells transfected by pcDNA3.1/Sestrin2 were significantly up-regulated(P<0.05), the cell proliferation was inhibited and the apoptosis was increased(P<0.05). In addition, the phosphorylation of AMPK was increased and the phosphorylation of mTOR was decreased by Sestrin2 overexpression(P<0.05).Conclusion Sestrin2 expression is down-regulated in nasopharyngeal carcinoma tissues. Moreover, the overexpression of Sestrin2 inhibits the proliferation and promotes the apoptosis of nasopharyngeal carcinoma cells, and the mechanism may be related to AMPK and mTOR signaling pathway.