title: Subunit composition of VRAC channels determines substrate specificity and cellular resistance to Pt-based anti-cancer drugs.
abstract: Although platinum-based drugs are widely used chemotherapeutics for cancer treatment, the determinants of tumor cell responsiveness remain poorly understood. We show that the loss of subunits LRRC8A and LRRC8D of the heteromeric LRRC8 volume-regulated anion channels (VRACs) increased resistance to clinically relevant cisplatin/carboplatin concentrations. Under isotonic conditions, about 50% of cisplatin uptake depended on LRRC8A and LRRC8D, but neither on LRRC8C nor on LRRC8E. Cell swelling strongly enhanced LRRC8-dependent cisplatin uptake, bolstering the notion that cisplatin enters cells through VRAC. LRRC8A disruption also suppressed drug-induced apoptosis independently from drug uptake, possibly by impairing VRAC-dependent apoptotic cell volume decrease. Hence, by mediating cisplatin uptake and facilitating apoptosis, VRAC plays a dual role in the cellular drug response. Incorporation of the LRRC8D subunit into VRAC substantially increased its permeability for cisplatin and the cellular osmolyte taurine, indicating that LRRC8 proteins form the channel pore. Our work suggests that LRRC8D-containing VRACs are crucial for cell volume regulation by an important organic osmolyte and may influence cisplatin/carboplatin responsiveness of tumors.
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Rosa
authors.initials: R
authors.lastname: Planells-Cases
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Darius
authors.initials: D
authors.lastname: Lutter
authors.affiliation: Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Guyader
authors.affiliation: Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
authors.forename: Nora M
authors.initials: NM
authors.lastname: Gerhards
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Ullrich
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Elger
authors.affiliation: Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Asli
authors.initials: A
authors.lastname: Kucukosmanoglu
authors.affiliation: Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Guotai
authors.initials: G
authors.lastname: Xu
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Felizia K
authors.initials: FK
authors.lastname: Voss
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: S Momsen
authors.initials: SM
authors.lastname: Reincke
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Stauber
authors.affiliation: Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Blomen
authors.affiliation: Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Vis
authors.affiliation: Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Lodewyk F
authors.initials: LF
authors.lastname: Wessels
authors.affiliation: Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Thijn R
authors.initials: TR
authors.lastname: Brummelkamp
authors.affiliation: Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Piet
authors.initials: P
authors.lastname: Borst
authors.affiliation: Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands sven.rottenberg@vetsuisse.unibe.ch Jentsch@fmp-berlin.de.
authors.forename: Sven
authors.initials: S
authors.lastname: Rottenberg
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany sven.rottenberg@vetsuisse.unibe.ch Jentsch@fmp-berlin.de.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Jentsch
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D016190:Carboplatin / Q000494:pharmacology*; D048429:Cell Size; D002945:Cisplatin / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm; D045325:HCT116 Cells; D057809:HEK293 Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C485976:LRRC8A protein, human; D008565:Membrane Proteins; D021122:Protein Subunits; D016190:Carboplatin; D002945:Cisplatin
keywords: VSOAC; VSOR; chloride channel; haploid cell screen; swelling‐activated