Open AccessMiR224-3p inhibits hypoxia-induced autophagy by targeting autophagy-related genes in human glioblastoma cells
Author(s) -
Xing Guo,
Hao Xue,
Xiaofan Guo,
Xiao Gao,
Shugang Xu,
Shaofeng Yan,
Xiao Han,
Tong Li,
Jie Shen,
Gang Li
Publication year - 2015
Publication title -
oncotarget
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.373
H-Index - 127
ISSN - 1949-2553
DOI - 10.18632/oncotarget.5871
Subject(s) - autophagy , atg5 , microrna , hypoxia (environmental) , carcinogenesis , cancer research , apoptosis , microbiology and biotechnology , biology , chemistry , gene , biochemistry , organic chemistry , oxygen
Human glioblastoma multiforme (GBM) is a malignant solid tumor characterized by severe hypoxia. Autophagy plays a protective role in cancer cells under hypoxia. However, the microRNA (miRNA)-related molecular mechanisms underlying hypoxia-reduced autophagy remain poorly understood in GBM. In this study, we performed a miRNA microarray analysis on GBM cells and found that numerous miRNAs were differentially expressed under hypoxic conditions. Further research showed that miR224-3p, one of the significantly down-regulated miRNAs, was involved in regulating hypoxia-induced autophagy in GBM cells. Overexpression of miR224-3p abolished hypoxia-induced autophagy, whereas knocking down endogenous miR224-3p increased autophagic activity under normoxia. In addition, we demonstrated that miR224-3p inhibited autophagy by directly suppressing the expression of two autophagy-related genes (ATGs), ATG5 and FAK family-interacting protein of 200 kDa (FIP200). Furthermore, in vitro, miR224-3p attenuated cell proliferation and promoted hypoxia-induced apoptosis, and in vivo, overexpression of miR224-3p inhibited tumorigenesis of GBM cells. Collectively, our study identified a novel hypoxia-down-regulated miRNA, miR224-3p, as a key modulator of autophagy by inhibiting ATGs in GBM cells.