Elvezia Maria Paraboschi1, Giulia Cardamone1, Valeria Rimoldi2, Stefano Duga2, Giulia Soldà2, Rosanna Asselta3. 1. Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy. 2. Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy. 3. Department of Biomedical Sciences, Humanitas University, Via Manzoni 113, 20089, Rozzano, Milan, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Milan, Italy. Electronic address: rosanna.asselta@hunimed.eu.
Abstract
BACKGROUND: The protein kinase C alpha (PRKCA) gene, coding for a Th17-cell-selective kinase, shows a complex splicing pattern, with at least 2 stable alternative transcripts characterized by an alternative upstream polyadenylation site. Polymorphisms in this gene were associated with several conditions, including multiple sclerosis, asthma, schizophrenia, and cancer. The presence of a microRNA (miRNA), i.e. miR-634, within intron 15 of the PRKCA gene, suggests the intriguing possibility that this miRNA might play a role in the susceptibility to these pathologies. METHODS: Here, we characterized miR-634 expression profile and searched for its putative targets using a combination of RT-PCR and gene reporter assays. RESULTS: The quantitative analysis of PRKCA and miR-634 transcripts in a panel of human tissues and cell lines revealed discordant expression profiles, suggesting the presence of an independent miR-634 promoter and/or a possible direct role of miR-634 in modulating PRKCA expression. Functional studies demonstrated the existence of a miRNA-specific promoter, which was shown to be Pol-III-dependent. Furthermore, transfection experiments showed that miR-634 is able to target its host gene by specifically down-regulating the shorter alternative-polyadenylated isoforms. CONCLUSIONS: MiR-634 is a Pol III-dependent intronic miRNA, which could target its host gene through a "first-order" negative feedback. GENERAL SIGNIFICANCE: MiR-634 is one of the few characterized examples of Pol-III-dependent intronic miRNAs. Its independent transcription from the host gene suggests caution in using expression profiles of host genes as proxies for the expression of the corresponding intronic miRNAs.
BACKGROUND: The protein kinase C alpha (PRKCA) gene, coding for a Th17-cell-selective kinase, shows a complex splicing pattern, with at least 2 stable alternative transcripts characterized by an alternative upstream polyadenylation site. Polymorphisms in this gene were associated with several conditions, including multiple sclerosis, asthma, schizophrenia, and cancer. The presence of a microRNA (miRNA), i.e. miR-634, within intron 15 of the PRKCA gene, suggests the intriguing possibility that this miRNA might play a role in the susceptibility to these pathologies. METHODS: Here, we characterized miR-634 expression profile and searched for its putative targets using a combination of RT-PCR and gene reporter assays. RESULTS: The quantitative analysis of PRKCA and miR-634 transcripts in a panel of human tissues and cell lines revealed discordant expression profiles, suggesting the presence of an independent miR-634 promoter and/or a possible direct role of miR-634 in modulating PRKCA expression. Functional studies demonstrated the existence of a miRNA-specific promoter, which was shown to be Pol-III-dependent. Furthermore, transfection experiments showed that miR-634 is able to target its host gene by specifically down-regulating the shorter alternative-polyadenylated isoforms. CONCLUSIONS:MiR-634 is a Pol III-dependent intronic miRNA, which could target its host gene through a "first-order" negative feedback. GENERAL SIGNIFICANCE: MiR-634 is one of the few characterized examples of Pol-III-dependent intronic miRNAs. Its independent transcription from the host gene suggests caution in using expression profiles of host genes as proxies for the expression of the corresponding intronic miRNAs.
Authors: Mathewos Tessema; Christin M Yingling; Maria A Picchi; Guodong Wu; Tyrone Ryba; Yong Lin; Aaron O Bungum; Eric S Edell; Avrum Spira; Steven A Belinsky Journal: Cancer Lett Date: 2017-09-29 Impact factor: 8.679
Authors: Ludwig C Hinske; Felipe R C Dos Santos; Daniel T Ohara; Lucila Ohno-Machado; Simone Kreth; Pedro A F Galante Journal: Database (Oxford) Date: 2017-01-01 Impact factor: 3.451