microRNA miR-142-3p Inhibits Breast Cancer Cell Invasiveness by Synchronous Targeting of WASL, Integrin Alpha V, and Additional Cytoskeletal Elements

• Published in: PloS one Vol. 10; no. 12; p. e0143993
• Main Authors: Schwickert, Alexander, Weghake, Esther, Brüggemann, Kathrin, Engbers, Annika, Brinkmann, Benjamin F, Kemper, Björn, Seggewiß, Jochen, Stock, Christian, Ebnet, Klaus, Kiesel, Ludwig, Riethmüller, Christoph, Götte, Martin
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 10.12.2015; Public Library of Science (PLoS)
• Subjects: 3' Untranslated Regions; Actin; Actins - metabolism; Atomic force microscopy; Base Sequence; Biochemistry; Breast cancer; Breast Neoplasms - genetics; Breast Neoplasms - pathology; Cancer; Cell adhesion & migration; Cell Line, Tumor; Cell morphology; Cell Movement; Cell Proliferation; Cell Size; Cortex; Cytology; Cytoskeletal proteins; Cytoskeleton; Cytoskeleton - metabolism; Down-Regulation; Female; Gene expression; Genetic aspects; Genetic regulation; Growth factors; Gynecology; Health aspects; Humans; Immunofluorescence; Integrin alphaV - chemistry; Integrin alphaV - genetics; Integrin alphaV - metabolism; Integrins; Interleukin 6; Invasiveness; Kinases; KLF4 protein; MCF-7 Cells; MicroRNA; MicroRNAs; MicroRNAs - chemistry; MicroRNAs - genetics; MicroRNAs - metabolism; Microscopy; miRNA; Motility; Obstetrics; Post-transcription; Rac1 protein; Regulators; Ribonucleic acid; RNA; RNA Interference; RNA, Small Interfering - metabolism; Sequence Alignment; siRNA; Target recognition; Tumorigenesis; Wiskott-Aldrich syndrome; Wiskott-Aldrich Syndrome Protein, Neuronal - antagonists & inhibitors; Wiskott-Aldrich Syndrome Protein, Neuronal - genetics; Wiskott-Aldrich Syndrome Protein, Neuronal - metabolism; United States > US; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0143993

MicroRNAs (miRNAs, micro ribonucleic acids) are pivotal post-transcriptional regulators of gene expression. These endogenous small non-coding RNAs play significant roles in tumorigenesis and tumor progression. miR-142-3p expression is dysregulated in several breast cancer subtypes. We aimed at investigating the role of miR-142-3p in breast cancer cell invasiveness. Supported by transcriptomic Affymetrix array analysis and confirmatory investigations at the mRNA and protein level, we demonstrate that overexpression of miR-142-3p in MDA-MB-231, MDA-MB-468 and MCF-7 breast cancer cells leads to downregulation of WASL (Wiskott-Aldrich syndrome-like, protein: N-WASP), Integrin-αV, RAC1, and CFL2, molecules implicated in cytoskeletal regulation and cell motility. ROCK2, IL6ST, KLF4, PGRMC2 and ADCY9 were identified as additional targets in a subset of cell lines. Decreased Matrigel invasiveness was associated with the miR-142-3p-induced expression changes. Confocal immunofluorescence microscopy, nanoscale atomic force microscopy and digital holographic microscopy revealed a change in cell morphology as well as a reduced cell volume and size. A more cortical actin distribution and a loss of membrane protrusions were observed in cells overexpressing miR-142-3p. Luciferase activation assays confirmed direct miR-142-3p-dependent regulation of the 3'-untranslated region of ITGAV and WASL. siRNA-mediated depletion of ITGAV and WASL resulted in a significant reduction of cellular invasiveness, highlighting the contribution of these factors to the miRNA-dependent invasion phenotype. While knockdown of WASL significantly reduced the number of membrane protrusions compared to controls, knockdown of ITGAV resulted in a decreased cell volume, indicating differential contributions of these factors to the miR-142-3p-induced phenotype. Our data identify WASL, ITGAV and several additional cytoskeleton-associated molecules as novel invasion-promoting targets of miR-142-3p in breast cancer.