文章基本信息

标题：miR-346 and miR-138 competitively regulate hTERT in GRSF1- and AGO2-dependent manners, respectively
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作者：Ge Song ; Renjie Wang ; Junfei Guo 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2015
卷号：5
期号：1
DOI：10.1038/srep15793
语种：English
出版社：Springer Nature
摘要：miRNAs typically downregulate the expression of target genes by binding to their 3′UTR, and dysregulation of miRNAs may contribute to tumorigenesis. Here, we found that miR-346 and miR-138 competitively bind to a common region in the 3′UTR of hTERT mRNA and have opposite effects on the expression and function of hTERT in human cervical cancer cells. Furthermore, G-rich RNA sequence binding factor 1 (GRSF1) mediates the miR-346-dependent upregulation of hTERT by binding to the miR-346 middle sequence motif (CCGCAU) which forms a “bulge loop” when miR-346 is bound to the hTERT 3′UTR, facilitating the recruitment of hTERT mRNA to ribosomes to promote translation in an AGO2-independent manner. Conversely, miR-138 suppresses hTERT expression in an AGO2-dependent manner. Interestingly, replacement of the miR-138 middle sequence with that of miR-346 results in an upregulation of hTERT expression in a GRSF1-dependent manner. Moreover, miR-346 depends on GRSF1 to upregulate another target gene, activin A receptor, type IIB (ACVR2B), in which miR-346 “CCGCAU” motif is essential. These findings reveal novel mechanisms of miRNA-mediated upregulation of target gene expression and describe the coordinated action of multiple miRNAs to control the fate of a single target mRNA through binding to its 3′UTR.