title: KCa1.1, a calcium-activated potassium channel subunit alpha 1, is targeted by miR-17-5p and modulates cell migration in malignant pleural mesothelioma.
abstract: Malignant pleural mesothelioma (MPM) is an aggressive, locally invasive, cancer elicited by asbestos exposure and almost invariably a fatal diagnosis. To date, we are one of the leading laboratory that compared microRNA expression profiles in MPM and normal mesothelium samples in order to identify dysregulated microRNAs with functional roles in mesothelioma. We interrogated a significant collection of MPM tumors and normal pleural samples in our biobank in search for novel therapeutic targets.
  
  
  
  Utilizing mRNA-microRNA correlations based on differential gene expression using Gene Set Enrichment Analysis (GSEA), we systematically combined publicly available gene expression datasets with our own MPM data in order to identify candidate targets for MPM therapy.
  
  
  
  We identified enrichment of target binding sites for the miR-17 and miR-30 families in both MPM tumors and cell lines. RT-qPCR revealed that members of both families were significantly downregulated in MPM tumors and cell lines. Interestingly, lower expression of miR-17-5p (P = 0.022) and miR-20a-5p (P = 0.026) was clearly associated with epithelioid histology. We interrogated the predicted targets of these differentially expressed microRNA families in MPM cell lines, and identified KCa1.1, a calcium-activated potassium channel subunit alpha 1 encoded by the KCNMA1 gene, as a target of miR-17-5p. KCa1.1 was overexpressed in MPM cells compared to the (normal) mesothelial line MeT-5A, and was also upregulated in patient tumor samples compared to normal mesothelium. Transfection of MPM cells with a miR-17-5p mimic or KCNMA1-specific siRNAs reduced mRNA expression of KCa1.1 and inhibited MPM cell migration. Similarly, treatment with paxilline, a small molecule inhibitor of KCa1.1, resulted in suppression of MPM cell migration.
  
  
  
  These functional data implicating KCa1.1 in MPM cell migration support our integrative approach using MPM gene expression datasets to identify novel and potentially druggable targets.
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.
authors.forename: Yuen Yee
authors.initials: YY
authors.lastname: Cheng
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.
authors.forename: Casey M
authors.initials: CM
authors.lastname: Wright
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.|Division of Thoracic Surgery, University Hospital Zurich, 8091, Zurich, Switzerland.
authors.forename: Michaela B
authors.initials: MB
authors.lastname: Kirschner
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.|School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Marissa
authors.initials: M
authors.lastname: Williams
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.
authors.forename: Kadir H
authors.initials: KH
authors.lastname: Sarun
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Sytnyk
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
authors.forename: Iryna
authors.initials: I
authors.lastname: Leshchynska
authors.affiliation: Cardiothoracic Surgical Unit, Royal Prince Alfred Hospital; The Baird Institute and Faculty of Medicine, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: J James
authors.initials: JJ
authors.lastname: Edelman
authors.affiliation: Cardiothoracic Surgical Unit, Royal Prince Alfred Hospital; The Baird Institute and Faculty of Medicine, The University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Vallely
authors.affiliation: Sydney Cardiothoracic Surgeons, RPA Medical Centre, Sydney, NSW, 2050, Australia.
authors.forename: Brian C
authors.initials: BC
authors.lastname: McCaughan
authors.affiliation: Department of Anatomical Pathology, Flinders Medical Centre, Adelaide, SA, 5042, Australia.
authors.forename: Sonja
authors.initials: S
authors.lastname: Klebe
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia.|School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia.
authors.forename: Nico
authors.initials: N
authors.lastname: van Zandwijk
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia. ruby.lin@sydney.edu.au.|School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia. ruby.lin@sydney.edu.au.
authors.forename: Ruby C Y
authors.initials: RC
authors.lastname: Lin
authors.affiliation: Asbestos Diseases Research Institute, Gate 3, Hospital Road, Concord, Sydney, NSW, 2139, Australia. glen.reid@sydney.edu.au.|School of Medicine, University of Sydney, Sydney, NSW, 2006, Australia. glen.reid@sydney.edu.au.
authors.forename: Glen
authors.initials: G
authors.lastname: Reid
mesh_terms: D020413:3' Untranslated Regions; D001665:Binding Sites; D045744:Cell Line, Tumor; D002465:Cell Movement; D030541:Databases, Genetic; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000235:genetics* / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics*; D008654:Mesothelioma / Q000235:genetics*; D000086002:Mesothelioma, Malignant; D035683:MicroRNAs / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D010997:Pleural Neoplasms / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; C494841:KCNMA1 protein, human; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; C524941:MIRN17 microRNA, human; D035683:MicroRNAs
keywords: Integrative analysis; KCNMA1; KCa1.1; Mesothelioma; Therapeutic targets; miR-17-5p; microRNA