Characterization of cannabinoid receptors expressed in Ewing sarcoma TC-71 and A-673 cells as potential targets for anti-cancer drug development.

Autor: Shoeib AM; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Yarbrough AL; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Ford BM; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Franks LN; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Urbaniak A; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Hensley LL; Department of Biology, Jacksonville State University, Jacksonville, AL, United States of America., Benson LN; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Mu S; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Radominska-Pandya A; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America., Prather PL; Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America. Electronic address: pratherpaull@uams.edu.
Jazyk: angličtina
Zdroj: Life sciences [Life Sci] 2021 Nov 15; Vol. 285, pp. 119993. Date of Electronic Publication: 2021 Sep 28.
DOI: 10.1016/j.lfs.2021.119993
Abstrakt: Aims: Characterizing cannabinoid receptors (CBRs) expressed in Ewing sarcoma (EWS) cell lines as potential targets for anti-cancer drug development.
Main Methods: CBR affinity and function were examined by competitive binding and G-protein activation, respectively. Cannabinoid-mediated cytotoxicity and cell viability were evaluated by LDH, and trypan blue assays, respectively.
Key Findings: qRT-PCR detected CB1 (CB1R) and CB2 receptor (CB2R) mRNA in TC-71 cells. However, binding screens revealed that CBRs expressed exhibit atypical properties relative to canonical receptors, because specific binding in TC-71 could only be demonstrated by the established non-selective CB1/CB2R radioligand [ 3 H]WIN-55,212-2, but not CB1/CB2R radioligand [ 3 H]CP-55,940. Homologous receptor binding demonstrated that [ 3 H]WIN-55,212-2 binds to a single site with nanomolar affinity, expressed at high density. Further support for non-canonical CBRs expression is provided by subsequent binding screens, revealing that only 9 out of 28 well-characterized cannabinoids with high affinity for canonical CB1 and/or CB2Rs were able to displace [ 3 H]WIN-55,212-2, whereas two ligands enhanced [ 3 H]WIN-55,212-2 binding. Five cannabinoids producing the greatest [ 3 H]WIN-55,212-2 displacement exhibited high nanomolar affinity (K i ) for expressed receptors. G-protein modulation and adenylyl cyclase assays further indicate that these CBRs exhibit distinct signaling/functional profiles compared to canonical CBRs. Importantly, cannabinoids with the highest affinity for non-canonical CBRs reduced TC-71 viability and induced cytotoxicity in a time-dependent manner. Studies in a second EWS cell line (A-673) showed similar atypical binding properties of expressed CBRs, and cannabinoid treatment produced cytotoxicity.
Significance: Cannabinoids induce cytotoxicity in EWS cell lines via non-canonical CBRs, which might be a potential therapeutic target to treat EWS.
(Copyright © 2021 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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