title: Cisplatin activates volume sensitive LRRC8 channel mediated currents in Xenopus oocytes.
abstract: LRRC8 proteins have been shown to underlie the ubiquitous volume regulated anion channel (VRAC). VRAC channels are composed of the LRRC8A subunit and at least one among the LRRC8B-E subunits. In addition to their role in volume regulation, LRRC8 proteins have been implicated in the uptake of chemotherapeutic agents. We had found that LRRC8 channels can be conveniently expressed in Xenopus oocytes, a system without endogenous VRAC activity. The fusion with fluorescent proteins yielded constitutive activity for A/C, A/D and A/E heteromers. Here we tested the effect of the anticancer drug cisplatin on LRRC8A-VFP/8E-mCherry and LRRC8A-VFP/8D-mCherry co-expressing oocytes. Incubation with cisplatin dramatically activated currents for both subunit combinations, confirming that VRAC channels provide an uptake pathway for cisplatin and that intracellular cisplatin accumulation strongly activates the channels. Thus, specific activators of LRRC8 proteins might be useful tools to counteract chemotherapeutic drug resistance.
authors.affiliation: a Institute of Biophysics, National Research Council , Genova , Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Gradogna
authors.affiliation: b Departament de Ciències Fisiològiques II , Unitat de Fisiologia, IDIBELL-Universitat de Barcelona, L'Hospitalet de Llobregat , Barcelona , Spain.|c Centro de Investigación en red de enfermedades raras (CIBERER), ISCIII , Barcelona , Spain.
authors.forename: Héctor
authors.initials: H
authors.lastname: Gaitán-Peñas
authors.affiliation: a Institute of Biophysics, National Research Council , Genova , Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Boccaccio
authors.affiliation: b Departament de Ciències Fisiològiques II , Unitat de Fisiologia, IDIBELL-Universitat de Barcelona, L'Hospitalet de Llobregat , Barcelona , Spain.|c Centro de Investigación en red de enfermedades raras (CIBERER), ISCIII , Barcelona , Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Estévez
authors.affiliation: a Institute of Biophysics, National Research Council , Genova , Italy.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-8644-8847
authors.initials: M
authors.lastname: Pusch
mesh_terms: D000818:Animals; D002945:Cisplatin / Q000494:pharmacology*; D055724:Electrophysiological Phenomena / Q000187:drug effects*; D007473:Ion Channels / Q000378:metabolism*; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism*; D014981:Xenopus
chemical_list: D007473:Ion Channels; D002945:Cisplatin
keywords: VRAC; anion; chloride channel; cisplatin; drug resistance; oocyte; volume regulation