title: Nanomechanical property maps of breast cancer cells as determined by multiharmonic atomic force microscopy reveal Syk-dependent changes in microtubule stability mediated by MAP1B.
abstract: The Syk protein-tyrosine kinase, a well-characterized modulator of immune recognition receptor signaling, also plays important, but poorly characterized, roles in tumor progression, acting as an inhibitor of cellular motility and metastasis in highly invasive cancer cells. Multiharmonic atomic force microscopy (AFM) was used to map nanomechanical properties of live MDA-MB-231 breast cancer cells either lacking or expressing Syk. The expression of Syk dramatically altered the cellular topography, reduced cell height, increased elasticity, increased viscosity, and allowed visualization of a more substantial microtubule network. The microtubules of Syk-expressing cells were more stable to nocodazole-induced depolymerization and were more highly acetylated than those of Syk-deficient cells. Silencing of MAP1B, a major substrate for Syk in MDA-MB-231 cells, attenuated Syk-dependent microtubule stability and reversed much of the effect of Syk on cellular topography, stiffness, and viscosity. This study illustrates the use of multiharmonic AFM both to quantitatively map the local nanomechanical properties of living cells and to identify the underlying mechanisms by which these properties are modulated by signal transduction machinery.
authors.affiliation: Department of Medicinal Chemistry and Molecular Pharmacology, ‡School of Mechanical Engineering, §Purdue Center for Cancer Research, and ∥Birck Nanotechnology Center, Purdue University , West Lafayette, Indiana 47907, United States.
authors.forename: Mariya O
authors.initials: MO
authors.lastname: Krisenko
authors.forename: Alexander
authors.initials: A
authors.lastname: Cartagena
authors.forename: Arvind
authors.initials: A
authors.lastname: Raman
authors.forename: Robert L
authors.initials: RL
authors.lastname: Geahlen
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D018625:Microscopy, Atomic Force / Q000379:methods*; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D008870:Microtubules / Q000378:metabolism* / Q000473:pathology; D036103:Nanotechnology / Q000379:methods*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D000072377:Syk Kinase
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C475491:MAP1B protein, human; D008869:Microtubule-Associated Proteins; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase