Xu Liyun, Hou Yixuan, Tu Gang, Chen Yanlin, Du Yan-E, Zhang Hailong, Wen Siyang, Tang Xi, Yin Jiali, Lang Lei, Sun Kexin, Yang Guanglun, Tang Xiaoli, Liu Manran
Key Laboratory of Laboratory Medical Diagnostics, Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China.
Experimental Teaching Center of Basic Medicine Science, Chongqing Medical University, Chongqing 400016, China.
Cell Death Dis. 2017 Mar 2;8(3):e2642. doi: 10.1038/cddis.2017.5.
Drosha is an RNA III-like enzyme that has an aberrant expression in some tumors. Our previous studies showed the aberrant Drosha in gastric tumors. However, the roles of nuclear Drosha, the main regulator of microRNA (miRNA) biogenesis, in gastric cancer (GC) progression remain poorly understood. In this study, we demonstrated that nuclear Drosha is significantly associated with cell invasion of GC and that Drosha silence impedes the tumor invasion. Knockdown of Drosha led to a set of dysregulated miRNAs in GC cells. Multiple targets of these miRNAs were the members in cell migration, invasion and metastasis-associated signaling (e.g. ECM-receptor interaction, focal adhesion, p53 signaling and MAPK signaling pathway) revealed by bioinformatics analysis. LAMC2 (a key element of ECM-receptor signaling) and CD82 (a suppressor of p53 signaling) are the targets of miR-622 and miR-197, respectively. High levels of LAMC2 and low levels of CD82 were significantly related to the worse outcome for GC patients. Furthermore, overexpression of LAMC2 and knockdown of CD82 markedly promoted GC cell invasion and activated EGFR/ERK1/2-MMP7 signaling via upregulation of the expression of phosphorylated (p)-EGFR, p-ERK1/2 and MMP7. Our findings suggest that nuclear Drosha potentially has a role in the development of GC.
Drosha是一种RNA III样酶,在某些肿瘤中存在异常表达。我们之前的研究显示胃癌中存在Drosha异常。然而,作为微小RNA(miRNA)生物合成主要调节因子的核内Drosha在胃癌(GC)进展中的作用仍知之甚少。在本研究中,我们证明核内Drosha与GC细胞侵袭显著相关,且Drosha沉默会阻碍肿瘤侵袭。敲低Drosha导致GC细胞中一组miRNA失调。生物信息学分析显示,这些miRNA的多个靶标是细胞迁移、侵袭和转移相关信号通路(如细胞外基质受体相互作用、粘着斑、p53信号通路和丝裂原活化蛋白激酶信号通路)的成员。LAMC2(细胞外基质受体信号的关键元件)和CD82(p53信号通路的抑制因子)分别是miR-622和miR-197的靶标。LAMC2高表达和CD82低表达与GC患者较差的预后显著相关。此外,LAMC2过表达和CD82敲低通过上调磷酸化(p)-表皮生长因子受体(EGFR)、p-细胞外调节蛋白激酶1/2(ERK1/2)和基质金属蛋白酶7(MMP7)的表达,显著促进GC细胞侵袭并激活EGFR/ERK1/2-MMP7信号通路。我们的研究结果表明,核内Drosha可能在GC的发生发展中发挥作用。