title: Assessment of multidrug resistance on cell coculture patterns using scanning electrochemical microscopy.
abstract: The emergence of resistance to multiple unrelated chemotherapeutic drugs impedes the treatment of several cancers. Although the involvement of ATP-binding cassette transporters has long been known, there is no in situ method capable of tracking this transporter-related resistance at the single-cell level without interfering with the cell's environment or metabolism. Here, we demonstrate that scanning electrochemical microscopy (SECM) can quantitatively and noninvasively track multidrug resistance-related protein 1-dependent multidrug resistance in patterned adenocarcinoma cervical cancer cells. Nonresistant human cancer cells and their multidrug resistant variants are arranged in a side-by-side format using a stencil-based patterning scheme, allowing for precise positioning of target cells underneath the SECM sensor. SECM measurements of the patterned cells, performed with ferrocenemethanol and [Ru(NH3)6](3+) serving as electrochemical indicators, are used to establish a kinetic "map" of constant-height SECM scans, free of topography contributions. The concept underlying the work described herein may help evaluate the effectiveness of treatment administration strategies targeting reduced drug efflux.
authors.affiliation: Department of Chemistry, Université du Québec à Montréal, Montreal, QC, Canada H2X 2J6.
authors.forename: Sabine
authors.initials: S
authors.lastname: Kuss
authors.forename: David
authors.initials: D
authors.lastname: Polcari
authors.forename: Matthias
authors.initials: M
authors.lastname: Geissler
authors.forename: Daniel
authors.initials: D
authors.lastname: Brassard
authors.forename: Janine
authors.initials: J
authors.lastname: Mauzeroll
mesh_terms: D018929:Cell Culture Techniques / Q000379:methods*; D018432:Drug Resistance, Multiple / Q000502:physiology*; D005260:Female; D005296:Ferrous Compounds; D006367:HeLa Cells; D006801:Humans; D008839:Microelectrodes; D008856:Microscopy, Fluorescence; D020527:Microscopy, Scanning Probe / Q000295:instrumentation / Q000379:methods*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism*
chemical_list: D005296:Ferrous Compounds; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C071550:ferrocenemethanol; C421109:multidrug resistance-associated protein 1
keywords: HeLa cells; MRP1; microelectrode