title: MicroRNA-99 family members suppress Homeobox A1 expression in epithelial cells.
abstract: The miR-99 family is one of the evolutionarily most ancient microRNA families, and it plays a critical role in developmental timing and the maintenance of tissue identity. Recent studies, including reports from our group, suggested that the miR-99 family regulates various physiological processes in adult tissues, such as dermal wound healing, and a number of disease processes, including cancer. By combining 5 independent genome-wide expression profiling experiments, we identified a panel of 266 unique transcripts that were down-regulated in epithelial cells transfected with miR-99 family members. A comprehensive bioinformatics analysis using 12 different sequence-based microRNA target prediction algorithms revealed that 81 out of these 266 down-regulated transcripts are potential direct targets for the miR-99 family. Confirmation experiments and functional analyses were performed to further assess 6 selected miR-99 target genes, including mammalian Target of rapamycin (mTOR), Homeobox A1 (HOXA1), CTD small phosphatase-like (CTDSPL), N-myristoyltransferase 1 (NMT1), Transmembrane protein 30A (TMEM30A), and SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 5 (SMARCA5). HOXA1 is a known proto-oncogene, and it also plays an important role in embryonic development. The direct targeting of the miR-99 family to two candidate binding sequences located in the HOXA1 mRNA was confirmed using a luciferase reporter gene assay and a ribonucleoprotein-immunoprecipitation (RIP-IP) assay. Ectopic transfection of miR-99 family reduced the expression of HOXA1, which, in consequence, down-regulated the expression of its downstream gene (i.e., Bcl-2) and led to reduced proliferation and cell migration, as well as enhanced apoptosis. In summary, we identified a number of high-confidence miR-99 family target genes, including proto-oncogene HOXA1, which may play an important role in regulating epithelial cell proliferation and migration during physiological disease processes, such as dermal wound healing and tumorigenesis.
authors: Center for Molecular Biology of Oral Diseases, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois, United States of America ; Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
authors: Dan
authors: D
authors: Chen
authors: Zujian
authors: Z
authors: Chen
authors: Yi
authors: Y
authors: Jin
authors: Dragan
authors: D
authors: Dragas
authors: Leitao
authors: L
authors: Zhang
authors: Barima S
authors: BS
authors: Adjei
authors: Anxun
authors: A
authors: Wang
authors: Yang
authors: Y
authors: Dai
authors: Xiaofeng
authors: X
authors: Zhou
mesh_terms: D002460:Cell Line; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D055106:Genome-Wide Association Study; D018398:Homeodomain Proteins / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000096:biosynthesis* / Q000235:genetics; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D000099261:Homeobox A1 Protein
chemical_list: D018398:Homeodomain Proteins; D035683:MicroRNAs; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D000099261:Homeobox A1 Protein; C000715470:MAS1 protein, human; C561679:MIRN99 microRNA, human