Chen Xin, Hao Bin, Han Guosheng, Liu Ying, Dai Dongwei, Li Yanan, Wu Xi, Zhou Xiaoping, Yue Zhijian, Wang Laixing, Cao Yiqun, Liu Jianmin
Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
J Cell Biochem. 2015 Feb;116(2):225-32. doi: 10.1002/jcb.24949.
MicroRNAs are known to be involved in carcinogenesis and tumor progression in glioma. Recently, microRNA-372 (miR-372) has been proved to play a substantial role in several human cancers, but its functions in glioma remain unclear. In this study, we confirmed that miR-372 was commonly upregulated in glioma cell lines and tissues. Downregulation of miR-372 markedly inhibited cell proliferation and invasion and induced G1/S arrest and apoptosis. Consistently, the xenograft mouse model also unveiled the suppressive effects of miR-372 knockdown on tumor growth. Further studies revealed that miR-372 modulated the expression of PHLPP2 by directly targeting its 3'-untranslated region (3'-UTR) and that miR-372 expression was inversely correlated with PHLPP2 expression in glioma samples. Silencing of PHLPP2 could rescue the inhibitory effect of miR-372 inhibitor. Moreover, miR-372 knockdown suppressed the phosphorylation levels of the major components of PI3K/Akt pathway including Akt, mTOR, and P70S6K. Taken together, our results suggest that miR-372 functions as an oncogenic miRNA through targeting PHLPP2 in glioma.
已知微小RNA参与神经胶质瘤的致癌作用和肿瘤进展。最近,已证明微小RNA - 372(miR - 372)在几种人类癌症中起重要作用,但其在神经胶质瘤中的功能仍不清楚。在本研究中,我们证实miR - 372在神经胶质瘤细胞系和组织中普遍上调。miR - 372的下调显著抑制细胞增殖和侵袭,并诱导G1/S期阻滞和细胞凋亡。同样,异种移植小鼠模型也揭示了miR - 372敲低对肿瘤生长的抑制作用。进一步研究表明,miR - 372通过直接靶向PHLPP2的3'-非翻译区(3'-UTR)来调节其表达,并且在神经胶质瘤样本中miR - 372表达与PHLPP2表达呈负相关。沉默PHLPP2可以挽救miR - 372抑制剂的抑制作用。此外,miR - 372敲低抑制了PI3K/Akt途径主要成分包括Akt、mTOR和P70S6K的磷酸化水平。综上所述,我们的结果表明miR - 372在神经胶质瘤中通过靶向PHLPP2发挥致癌性微小RNA的作用。