Ruiz Esparza-Garrido Ruth, Torres-Márquez María Eugenia, Viedma-Rodríguez Rubí, Velázquez-Wong Ana Claudia, Salamanca-Gómez Fabio, Rosas-Vargas Haydeé, Velázquez-Flores Miguel Ángel
CONACyT Research Fellow, Functional Genomics Laboratory, Unit of Human Genetics Research, Children's Hospital, National Medical Center Century XXI, Mexican Institute of Social Security (IMSS), México, C.P. 06720, DF, México.
Functional Genomics Laboratory, Unit of Human Genetics Research, Children's Hospital, National Medical Center Century XXI, Mexican Institute of Social Security (IMSS), México, C.P. 06720, DF, México.
Tumour Biol. 2016 May;37(5):6749-59. doi: 10.1007/s13277-015-4494-8. Epub 2015 Dec 10.
B-cell lymphoma 2 (BCL2)-interacting killer (apoptosis inducing) (BIK) has been proposed as a tumor suppressor in diverse types of cancers. However, BIK's overexpression in breast cancer (BC) and in non-small lung cancer cells (NSCLCs), associated with a poor prognosis, suggests its participation in tumor progression. In this study, we evaluated the global expression pattern of microRNAs (miRNAs), messenger RNA (mRNA) expression changes in autophagy, and autophagic flux after BIK interference. BIK gene expression was silenced by small interfering RNA (siRNA) in BC cell MDA-MB-231, and BIK interference efficiency was tested by real-time PCR and by Western blotting. BIK expression levels decreased by 75 ± 18 % in the presence of 600 nM siRNA, resulting in the abolishment of BIK expression by 94 ± 30 %. BIK interference resulted in the overexpression of 17 miRNAs that, according to the DIANA-miRPath v3.0 database, are mainly implied in the control of cell signaling, gene expression, and autophagy. The autophagy array revealed downregulation of transcripts which participate in autophagy, and their interactome revealed a complex network, where hepatocyte growth factor-regulated tyrosine kinase substrate (HGS), α-synuclein (SNCA), unc-51-like autophagy activating kinase 1/2 (ULK1/2), and mitogen-activated protein kinase 3 (MAPK3) were shown to be signaling hubs. LC3-II expression-an autophagy marker-was increased by 169 ± 25 % after BIK interference, which indicates the involvement of BIK in autophagy. Altogether, our results indicate-for the first time-that BIK controls the expression of miRNAs, as well as the autophagic flux in MDA-MB-231 cells.
B细胞淋巴瘤2(BCL2)相互作用杀伤(凋亡诱导)蛋白(BIK)被认为是多种癌症中的一种肿瘤抑制因子。然而,BIK在乳腺癌(BC)和非小细胞肺癌细胞(NSCLC)中过表达,且与预后不良相关,这表明它参与了肿瘤进展。在本研究中,我们评估了微小RNA(miRNA)的整体表达模式、自噬过程中信使核糖核酸(mRNA)的表达变化以及BIK干扰后的自噬通量。通过小干扰RNA(siRNA)使BC细胞MDA-MB-231中的BIK基因表达沉默,并通过实时聚合酶链反应和蛋白质免疫印迹法检测BIK干扰效率。在存在600 nM siRNA的情况下,BIK表达水平降低了75±18%,导致BIK表达被消除了94±30%。BIK干扰导致17种miRNA过表达,根据DIANA-miRPath v3.0数据库,这些miRNA主要参与细胞信号传导、基因表达和自噬的调控。自噬阵列显示参与自噬的转录本下调,其相互作用组揭示了一个复杂的网络,其中肝细胞生长因子调节的酪氨酸激酶底物(HGS)、α-突触核蛋白(SNCA)、unc-51样自噬激活激酶1/2(ULK1/2)和丝裂原活化蛋白激酶3(MAPK3)被证明是信号枢纽。自噬标志物LC3-II的表达在BIK干扰后增加了169±25%,这表明BIK参与了自噬。总之,我们的结果首次表明,BIK控制miRNA的表达以及MDA-MB-231细胞中的自噬通量。