沉默MARCH2通过ATF4-CHOP-TRIB3-AKT-MTOR轴调控结肠癌细胞自噬

目的探讨结肠癌细胞中MARCH2调控自噬的机制。方法采用RNA干扰技术和Western blot法检测沉默MARCH2的结肠癌细胞中内质网应激相关蛋白水平、TRIB3蛋白水平、AKT-MTOR信号通路及自噬水平的相关性。结果沉默MARCH2的结肠癌HCT116细胞中AKT-MTOR信号减弱,TRIB3、CHOP和ATG12-ATG5结合物蛋白水平升高。沉默CHOP会引起TRIB3的蛋白水平降低;敲减TRIB3引起AKT-MTOR信号有所回升;敲减ATF4导致CHOP和TRIB3蛋白水平降低,AKT-MTOR信号回升,ATG12-ATG5结合物水平降低。结论沉默MARCH2可能通过上调CHOP,从而升高TRIB3,导致AKT-MTOR抑制,最终促进自噬发生。ATF4-CHOP-TRIB3-AKT-MTOR轴在沉默MARCH2诱导自噬发生过程中起非常重要的作用。

MARCH2 silence mediated autophagy via the ATF4-CHOP-TRIB3-AKT-MTOR axis

Purpose To explore the mechanism of MARCH2-regulated autophagy in colon cancer cells.Methods The expression of endoplasmic reticulum stress-associated proteins,TRIB1,AKT,MTOR and ATG12-ATG5 conjugate were examined in colon cancer cells using RNA interference and Western blot.Results The signaling of AKT-MTOR was down-regulated in MARCH2-dificient colon cancer HCT116 cells,while the expression of TRIB3,CHOP or ATG12-ATG5 conjugate was elevated.Western blot showed that CHOP knockdown reversed the accumulation of TRIB3 induced by shMARCH2.TRIB3 knockdown reversed the decrease of AKT-MTOR signaling induced by shMARCH2.ATF4 knockdown reversed the increase of CHOP,TRIB3 or ATG12-ATG5 conjugate and the decrease of AKT-MTOR signaling induced by shMARCH2.Conclusion MARCH2 silence may increase the levels of TRIB3 via enhancing the expression of CHOP protein,leading to the inhibition of AKT-MTOR signaling,ultimately promoting autophagy.ATF4-CHOP-TRIB3-AKT-MTOR axis plays an important role in MARCH2 silence-induced autophagy.