title: Dual regulation by microRNA-200b-3p and microRNA-200b-5p in the inhibition of epithelial-to-mesenchymal transition in triple-negative breast cancer.
abstract: Epithelial to mesenchymal transition (EMT) involves loss of an epithelial phenotype and activation of a mesenchymal one. Enhanced expression of genes associated with a mesenchymal transition includes ZEB1/2, TWIST, and FOXC1. miRNAs are known regulators of gene expression and altered miRNA expression is known to enhance EMT in breast cancer. Here we demonstrate that the tumor suppressive miRNA family, miR-200, is not expressed in triple negative breast cancer (TNBC) cell lines and that miR-200b-3p over-expression represses EMT, which is evident through decreased migration and increased CDH1 expression. Despite the loss of migratory capacity following re-expression of miR-200b-3p, no subsequent loss of the conventional miR-200 family targets and EMT markers ZEB1/2 was observed. Next generation RNA-sequencing analysis showed that enhanced expression of pri-miR-200b lead to ectopic expression of both miR-200b-3p and miR-200b-5p with multiple isomiRs expressed for each of these miRNAs. Furthermore, miR-200b-5p was expressed in the receptor positive, epithelial breast cancer cell lines but not in the TNBC (mesenchymal) cell lines. In addition, a compensatory mechanism for miR-200b-3p/200b-5p targeting, where both miRNAs target the RHOGDI pathway leading to non-canonical repression of EMT, was demonstrated. Collectively, these data are the first to demonstrate dual targeting by miR-200b-3p and miR-200b-5p and a previously undescribed role for microRNA processing and strand expression in EMT and TNBC, the most aggressive breast cancer subtype.
authors.affiliation: Department of Biological Sciences, Florida Gulf Coast University, Fort Myers, FL, USA.
authors.forename: Lyndsay V
authors.initials: LV
authors.lastname: Rhodes
authors.affiliation: Department of Medicine, Section of Hematology and Medical Oncology, Tulane University, New Orleans, LA, USA.
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Martin
authors.affiliation: Department of Medicine, Section of Hematology and Medical Oncology, Tulane University, New Orleans, LA, USA.
authors.forename: H Chris
authors.initials: HC
authors.lastname: Segar
authors.affiliation: Medical Sciences and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Bloomington, IN, USA.
authors.forename: David F B
authors.initials: DF
authors.lastname: Miller
authors.affiliation: Indiana University Center for Genomics and Bioinformatics, Bloomington, IN, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Buechlein
authors.affiliation: Indiana University Center for Genomics and Bioinformatics, Bloomington, IN, USA.
authors.forename: Douglas B
authors.initials: DB
authors.lastname: Rusch
authors.affiliation: Medical Sciences and Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Bloomington, IN, USA.
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Nephew
authors.affiliation: Department of Medicine, Section of Hematology and Medical Oncology, Tulane University, New Orleans, LA, USA.|Department of Pharmacology, Tulane University, New Orleans, LA, USA.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Burow
authors.affiliation: Department of Medicine, Section of Hematology and Medical Oncology, Tulane University, New Orleans, LA, USA.
authors.forename: Bridgette M
authors.initials: BM
authors.lastname: Collins-Burow
mesh_terms: D015703:Antigens, CD; D001483:Base Sequence; D015820:Cadherins / Q000096:biosynthesis; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D005260:Female; D051858:Forkhead Transcription Factors / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D061986:MCF-7 Cells; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000235:genetics; D064726:Triple Negative Breast Neoplasms / Q000235:genetics*; D051879:Twist-Related Protein 1 / Q000235:genetics; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha / Q000378:metabolism*
chemical_list: C569638:ARHGDIA protein, human; D015703:Antigens, CD; C513384:CDH1 protein, human; D015820:Cadherins; C112743:FOXC1 protein, human; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; C533896:MIRN200 microRNA, human; D035683:MicroRNAs; D009687:Nuclear Proteins; D012097:Repressor Proteins; C103173:TWIST1 protein, human; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C486307:ZEB1 protein, human; C492363:ZEB2 protein, human; D000074165:Zinc Finger E-box Binding Homeobox 2; D000071799:Zinc Finger E-box-Binding Homeobox 1; D062948:rho Guanine Nucleotide Dissociation Inhibitor alpha
keywords: RHOGDI; isomiRs; miRNA biogenesis; star strand; triple negative breast cancer