2. Academic Validation
  3. Subunit composition of VRAC channels determines substrate specificity and cellular resistance to Pt-based anti-cancer drugs

Subunit composition of VRAC channels determines substrate specificity and cellular resistance to Pt-based anti-cancer drugs

  • EMBO J. 2015 Dec 14;34(24):2993-3008. doi: 10.15252/embj.201592409.
Rosa Planells-Cases 1,  Darius Lutter 1,  Charlotte Guyader 2,  Nora M Gerhards 3,  Florian Ullrich 1,  Deborah A Elger 1,  Asli Kucukosmanoglu 4,  Guotai Xu 4,  Felizia K Voss 1,  S Momsen Reincke 1,  Tobias Stauber 1,  Vincent A Blomen 5,  Daniel J Vis 6,  Lodewyk F Wessels 6,  Thijn R Brummelkamp 5,  Piet Borst 2,  Sven Rottenberg 7,  Thomas J Jentsch 8
Affiliations

Affiliations

  • 1 Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany.
  • 2 Division of Molecular Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
  • 3 Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
  • 4 Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
  • 5 Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
  • 6 Division of Molecular Carcinogenesis, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
  • 7 Institute of Animal Pathology, Vetsuisse Faculty, University of Bern, Bern, Switzerland Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands [email protected] [email protected].
  • 8 Leibniz-Institut für Molekulare Pharmakologie (FMP) Max-Delbrück-Centrum für Molekulare Medizin (MDC), Berlin, Germany NeuroCure Cluster of Excellence, Charité Universitätsmedizin, Berlin, Germany [email protected] [email protected].
PMID: 26530471 DOI: 10.15252/embj.201592409
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.

Keywords

VSOAC; VSOR; chloride channel; haploid cell screen; swelling‐activated.

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