Wongfieng Wipaporn, Jumnainsong Amonrat, Chamgramol Yaovalux, Sripa Banchob, Leelayuwat Chanvit
Biomedical Sciences Program, Graduates School of Khon Kaen University, Khon Kaen 40002, Thailand.
Department of Clinical Immunology and Transfusion Sciences, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand.
Genes (Basel). 2017 Aug 29;8(9):213. doi: 10.3390/genes8090213.
The treatment of cancer through the induction of natural killer group 2, member D (NKG2D) ligands is of interest, but understanding of mechanisms controlling expression of individual ligand is limited. The major histocompatibility complex (MHC) class I chain related protein B (MICB) is a member of NKG2D ligands. We aimed to investigate the role of 3'-untranslated (3'-UTR) and 5'-untranslated regions (5'-UTR) in post-transcriptional regulation of MICB. Nine novel microRNAs (miRNAs) predicted to interact with 3'-UTR and 5'-UTR using TargetScan, RNAhybrid and miBridge were identified. Their regulation of 3'-UTR, 5'-UTR and both 3'- and 5'-UTR sequences of MICB were indicated by the reduction of luciferase activities of luciferase reporter constructs. Mutations of miRNA binding sites at 3'- and 5'-UTRs resulted in increased luciferase activities confirming the regulation of nine candidate miRNAs. In addition, overexpression of candidate miRNAs also down-regulated the expression of reporter constructs. Consequently, the overexpression and inhibition of candidate miRNAs lead to the decreased and increased. MICB protein expressions on the cells tested, respectively. This study has identified a new role of miRNAs in regulation of MICB expression via both 3'-UTR and 5'-UTR sequences applicable for cancer immunotherapy.
通过诱导自然杀伤细胞2族D成员（NKG2D）配体来治疗癌症备受关注，但对控制单个配体表达机制的了解有限。主要组织相容性复合体（MHC）I类链相关蛋白B（MICB）是NKG2D配体的成员之一。我们旨在研究3'非翻译区（3'-UTR）和5'非翻译区（5'-UTR）在MICB转录后调控中的作用。利用TargetScan、RNAhybrid和miBridge软件，我们鉴定出9个预测可与3'-UTR和5'-UTR相互作用的新型微小RNA（miRNA）。荧光素酶报告基因构建体的荧光素酶活性降低表明了它们对MICB的3'-UTR、5'-UTR以及3'-UTR和5'-UTR序列的调控作用。3'-UTR和5'-UTR处miRNA结合位点的突变导致荧光素酶活性增加，证实了这9个候选miRNA的调控作用。此外，候选miRNA的过表达也下调了报告基因构建体的表达。因此，候选miRNA的过表达和抑制分别导致所测试细胞上MICB蛋白表达的降低和增加。本研究确定了miRNA在通过3'-UTR和5'-UTR序列调控MICB表达中的新作用，这一发现适用于癌症免疫治疗。
