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.