title: Label-free recognition of drug resistance via impedimetric screening of breast cancer cells.
abstract: We present a novel study on label-free recognition and distinction of drug resistant breast cancer cells (MCF-7 DOX) from their parental cells (MCF-7 WT) via impedimetric measurements. Drug resistant cells exhibited significant differences in their dielectric properties compared to wild-type cells, exerting much higher extracellular resistance (Rextra ). Immunostaining revealed that MCF-7 DOX cells gained a much denser F-actin network upon acquiring drug resistance indicating that remodeling of actin cytoskeleton is probably the reason behind higher Rextra , providing stronger cell architecture. Moreover, having exposed both cell types to doxorubicin, we were able to distinguish these two phenotypes based on their substantially different drug response. Interestingly, impedimetric measurements identified a concentration-dependent and reversible increase in cell stiffness in the presence of low non-lethal drug doses. Combined with a profound frequency analysis, these findings enabled distinguishing distinct cellular responses during drug exposure within four concentration ranges without using any labeling. Overall, this study highlights the possibility to differentiate drug resistant phenotypes from their parental cells and to assess their drug response by using microelectrodes, offering direct, real-time and noninvasive measurements of cell dependent parameters under drug exposure, hence providing a promising step for personalized medicine applications such as evaluation of the disease progress and optimization of the drug treatment of a patient during chemotherapy.
authors.affiliation: Laboratory of Microsystems (LMIS4), École polytechnique fédérale de Lausanne, Station 17, CH-1015 Lausanne, Switzerland. bilge.eker@epfl.ch
authors.forename: Bilge
authors.initials: B
authors.lastname: Eker
authors.forename: Robert
authors.initials: R
authors.lastname: Meissner
authors.forename: Arnaud
authors.initials: A
authors.lastname: Bertsch
authors.forename: Kapil
authors.initials: K
authors.lastname: Mehta
authors.forename: Philippe
authors.initials: P
authors.lastname: Renaud
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology / Q000627:therapeutic use; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D017097:Electric Impedance; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D013194:Staining and Labeling; D019108:Tight Junctions / Q000187:drug effects / Q000378:metabolism
chemical_list: D004317:Doxorubicin