It has been shown that imprecise cleavage of a primary or precursor RNA by Drosha or Dicer, respectively, may yield a group of microRNA (miRNA) variants designated as "isomiR". Variations in the relative abundance of isoforms for a given miRNA among different species and different cell types beg the question whether these isomiRs might regulate target genes differentially. We compared the capacity of three miR-31 isoforms (miR-31-H, miR-31-P, and miR-31-M), which differ only slightly in their 5'- and/or 3'-end sequences, to regulate several known targets and a predicted target, Dicer. Notably, we found isomiR-31s displayed concordant and discordant regulation of 6 known target genes. Furthermore, we validated a predicted target gene, Dicer, to be a novel target of miR-31 but only miR-31-P could directly repress Dicer expression in both MCF-7 breast cancer cells and A549 lung cancer cells, resulting in their enhanced sensitivity to cisplatin, a known attribute of Dicer knockdown. This was further supported by reporter assay using full length 3'-untranslated region (UTR) of Dicer. Our findings not only revealed Dicer to be a direct target of miR-31, but also demonstrated that isomiRs displayed similar and disparate regulation of target genes in cell-based systems. Coupled with the variations in the distribution of isomiRs among different cells or conditions, our findings support the possibility of fine-tuning gene expression by miRNAs.
Pubmed ID: 23472152 RIS Download
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A research tool company focused on the creation of the largest commercial collection of full-length human cDNAs in a standard expression vector. The availability of the complete human genome sequence and the subsequent development of genome-based tools have enabled the identification of relevant drug targets through system biology approaches. OriGene''s vision is to prepare comprehensive, genome wide research tools and technology platforms to enable scientists to study complete biological pathways, thus enabling a better understanding of disease mechanisms including cancer and stem cell research. OriGene Technologies uses high-throughput, genome wide approach to develop products for pharmaceutical, biotechnology, and academic research. Their flagship product is the cDNA clone collection, a searchable gene bank of over 30,000 human full-length TrueClone cDNA collection and over 25,000 TrueORF cDNA clones. From their TrueORF cDNA clones, they have developed the largest offering of full length human proteins expressed in mammalian cells, ideal for functional studies. Their TrueMAB project develops mouse monoclonal antibodies against protein antigens with the goal to develop protein assays for every human protein. They also offer complete molecular biology services from codon optimization, gene synthesis, protein expression and assay development. In addition, they offer unique gene expression products such as TissueScan cancer tissue qPCR arrays and tissue biorepository for biomarker discovery and validation.
View all literature mentionsAn antibody supplier for the purposes of life science and biomedical research. This company has a wide variety of immunological reagents that focus on areas of research such as cancer, cell biology, epigenetics, immunology and infectious diseases.
View all literature mentionsCell line MDA-MB-231 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line MCF-7 is a Cancer cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line A-549 is a Cancer cell line with a species of origin Homo sapiens (Human)
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