title: MiRNA-Target Interaction Reveals Cell-Specific Post-Transcriptional Regulation in Mammalian Cell Lines.
abstract: MicroRNAs are 18-22 nucleotides long, non-coding RNAs that bind transcripts with complementary sequences leading to either mRNA degradation or translational suppression. However, the inherent differences in preferred mode of miRNA regulation among cells of different origin have not been examined. In our previous transcriptome profiling studies, we observed that post-transcriptional regulation can differ substantially depending on the cell in context. Here we examined mechanistic differences in the regulation of a let-7a targeted (wild type) or resistant (mutant) engineered renilla transcript across various mammalian cell lines of diverse origin. Dual luciferase assays show that compared to mutant (mut), the reporter gene containing wild type (wt) let-7a binding sites was efficiently suppressed upon transfection in various cell lines. Importantly, the strength of miRNA regulation varied across the cell lines. Total RNA analysis demonstrates that wt renilla mRNA was expressed to similar or higher levels compared to mut suggesting that translation repression is a predominant mode of miRNA regulation. Nonetheless, transcript degradation was observed in some cell lines. Ago-2 immunoprecipitation show that miRNA repressed renilla mRNA are associated with functional mi-RISC (miRNA-RNA induced silencing complex). Given the immense potential of miRNA as a therapeutic option, these findings highlight the necessity to thoroughly examine the mode of mRNA regulation in order to achieve the beneficial effects in targeting cells.
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago, 458 Dent MC 859, 801 S. Paulina, Chicago, IL 60612, USA. vrun_k@hotmail.com.
authors.forename: Varun
authors.initials: V
authors.lastname: Kulkarni
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago, 458 Dent MC 859, 801 S. Paulina, Chicago, IL 60612, USA. afsarraz@uic.edu.
authors.forename: Afsar Raza
authors.initials: AR
authors.lastname: Naqvi
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago, 458 Dent MC 859, 801 S. Paulina, Chicago, IL 60612, USA. juttam2@uic.edu.
authors.forename: Juhi Raju
authors.initials: JR
authors.lastname: Uttamani
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago, 458 Dent MC 859, 801 S. Paulina, Chicago, IL 60612, USA. snares@uic.edu.
authors.forename: Salvador
authors.initials: S
authors.lastname: Nares
mesh_terms: D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006367:HeLa Cells; D056945:Hep G2 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D051379:Mice; D035683:MicroRNAs / Q000235:genetics*; D009154:Mutation; D041681:NIH 3T3 Cells; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics*; D034743:RNA-Induced Silencing Complex / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; D034743:RNA-Induced Silencing Complex; C487931:mirnlet7 microRNA, human
keywords: Ago-2 (Argonaute-2); cell lines; gene regulation; microRNA