title: Myoferlin depletion elevates focal adhesion kinase and paxillin phosphorylation and enhances cell-matrix adhesion in breast cancer cells.
abstract: Breast cancer is the second leading cause of malignant death among women. A crucial feature of metastatic cancers is their propensity to lose adhesion to the underlying basement membrane as they transition to a motile phenotype and invade surrounding tissue. Attachment to the extracellular matrix is mediated by a complex of adhesion proteins, including integrins, signaling molecules, actin and actin-binding proteins, and scaffolding proteins. Focal adhesion kinase (FAK) is pivotal for the organization of focal contacts and maturation into focal adhesions, and disruption of this process is a hallmark of early cancer invasive potential. Our recent work has revealed that myoferlin (MYOF) mediates breast tumor cell motility and invasive phenotype. In this study we demonstrate that noninvasive breast cancer cell lines exhibit increased cell-substrate adhesion and that silencing of MYOF using RNAi in the highly invasive human breast cancer cell line MDA-MB-231 also enhances cell-substrate adhesion. In addition, we detected elevated tyrosine phosphorylation of FAK (FAK(Y397)) and paxillin (PAX(Y118)), markers of focal adhesion protein activation. Morphometric analysis of PAX expression revealed that RNAi-mediated depletion of MYOF resulted in larger, more elongated focal adhesions, in contrast to cells transduced with a control virus (MDA-231(LVC) cells), which exhibited smaller focal contacts. Finally, MYOF silencing in MDA-MB-231 cells exhibited a more elaborate ventral cytoskeletal structure near focal adhesions, typified by pronounced actin stress fibers. These data support the hypothesis that MYOF regulates cell adhesions and cell-substrate adhesion strength and may account for the high degree of motility in invasive breast cancer cells.
authors: Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio;
authors: B N
authors: BN
authors: Blackstone
authors: Laboratory of Perinatal Research and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Wexner Medical Center and College of Medicine, The Ohio State University, Columbus, Ohio;
authors: R
authors: R
authors: Li
authors: Laboratory of Perinatal Research and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Wexner Medical Center and College of Medicine, The Ohio State University, Columbus, Ohio;
authors: W E
authors: WE
authors: Ackerman
authors: Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio; Dorothy M. Davis Heart and Lung Research Institute and Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, Wexner Medical Center and College of Medicine, The Ohio State University, Columbus, Ohio; and.
authors: S N
authors: http://orcid.org/0000-0002-6845-774X
authors: SN
authors: Ghadiali
authors: Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio; Department of Materials Science and Engineering, College of Engineering, The Ohio State University, Columbus, Ohio.
authors: H M
authors: HM
authors: Powell
authors: Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio; Laboratory of Perinatal Research and Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Wexner Medical Center and College of Medicine, The Ohio State University, Columbus, Ohio; kniss.1@osu.edu.
authors: D A
authors: DA
authors: Kniss
mesh_terms: D001943:Breast Neoplasms / Q000473:pathology*; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002448:Cell Adhesion / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement; D021982:Cell-Matrix Junctions; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism*; D022001:Focal Adhesions / Q000235:genetics / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000235:genetics*; D009124:Muscle Proteins / Q000235:genetics*; D009361:Neoplasm Invasiveness; D051419:Paxillin / Q000378:metabolism*; D010766:Phosphorylation; D034622:RNA Interference; D034741:RNA, Small Interfering
chemical_list: D002135:Calcium-Binding Proteins; C415584:MYOF protein, human; D008565:Membrane Proteins; D009124:Muscle Proteins; D051419:Paxillin; D034741:RNA, Small Interfering; D051416:Focal Adhesion Protein-Tyrosine Kinases
keywords: breast cancer; cell adhesion; cell mechanics; cell motility; myoferlin