title: TGF-β1 suppression of microRNA-450b-5p expression: a novel mechanism for blocking myogenic differentiation of rhabdomyosarcoma.
abstract: Transforming growth factor beta 1 (TGF-β1) is the most potent inhibitor of myogenic differentiation (MyoD) of rhabdomyosarcoma (RMS); however, the underlying mechanisms of this inhibition remain unclear. In this study, we identified novel TGF-β1-related microRNAs (miRNAs); among these, miR-450b-5p is significantly regulated by TGF-β1. We provide evidence that TGF-β1 exerts it function by suppressing miR-450b-5p. Both in cultured cells and tumor implants, miR-450b-5p significantly arrested the growth of RMS and promoted its MyoD. Utilizing a bioinformatics approach, we identified miR-450b-5p target mRNAs. Among these candidates, only the expression of ecto-NOX disulfide-thiol exchanger 2 (ENOX2) and paired box 9 (PAX9) was augmented by miR-450b-5p knockdown examined by western blot; the engineered inhibition antagonized TGF-β1-mediated differentiation inhibition. Furthermore, we found that the Smad3 and Smad4 pathways, but not Smad2, are the principal mediator of TGF-β1 suppression of miR-450b-5p. Taken together, these results suggest that disrupting the TGF-β1 suppression of miR-450b-5p, or knockdown of ENOX2 and PAX9, are effective approaches in inducing RMS MyoD.
authors.affiliation: Department of Anatomy, Soochow University School of Medicine, Suzhou, China.
authors.forename: M M
authors.initials: MM
authors.lastname: Sun
authors.affiliation: Department of Pathology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: J F
authors.initials: JF
authors.lastname: Li
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: L L
authors.initials: LL
authors.lastname: Guo
authors.affiliation: Department of Burn and Plastic Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: H T
authors.initials: HT
authors.lastname: Xiao
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: L
authors.initials: L
authors.lastname: Dong
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: F B
authors.initials: FB
authors.lastname: Huang
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: D
authors.initials: D
authors.lastname: Cao
authors.affiliation: Department of Anatomy, Soochow University School of Medicine, Suzhou, China.
authors.forename: T
authors.initials: T
authors.lastname: Qin
authors.affiliation: Department of Anatomy, Soochow University School of Medicine, Suzhou, China.
authors.forename: X H
authors.initials: XH
authors.lastname: Yin
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: J M
authors.initials: JM
authors.lastname: Li
authors.affiliation: Department of Pathology, Soochow University School of Medicine, Suzhou, China.
authors.forename: S L
authors.initials: SL
authors.lastname: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D017570:MyoD Protein / Q000235:genetics* / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D051764:PAX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012208:Rhabdomyosarcoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D059467:Transcriptome / Q000187:drug effects / Q000235:genetics; D053773:Transforming Growth Factor beta1 / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D023041:Xenograft Model Antitumor Assays / Q000379:methods
chemical_list: C000589024:MIRN450 microRNA, human; D035683:MicroRNAs; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D051764:PAX9 Transcription Factor; C497323:PAX9 protein, human; D053773:Transforming Growth Factor beta1; D009247:NADH, NADPH Oxidoreductases; C431909:tumor-associated NADH oxidase