RT Journal Article SR Electronic T1 A Comprehensive Functional Assessment of Carboxylesterase 1 Nonsynonymous Polymorphisms JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1149 OP 1155 DO 10.1124/dmd.117.077669 VO 45 IS 11 A1 Xinwen Wang A1 Nada Rida A1 Jian Shi A1 Audrey H. Wu A1 Barry E. Bleske A1 Hao-Jie Zhu YR 2017 UL http://dmd.aspetjournals.org/content/45/11/1149.abstract AB Carboxylesterase 1 (CES1) is the predominant human hepatic hydrolase responsible for the metabolism of many clinically important medications. CES1 expression and activity vary markedly among individuals; and genetic variation is a major contributing factor to CES1 interindividual variability. In this study, we comprehensively examined the functions of CES1 nonsynonymous single nucleotide polymorphisms (nsSNPs) and haplotypes using transfected cell lines and individual human liver tissues. The 20 candidate variants include CES1 nsSNPs with a minor allele frequency >0.5% in a given population or located in close proximity to the CES1 active site. Five nsSNPs, including L40Ter (rs151291296), G142E (rs121912777), G147C (rs146456965), Y170D (rs148947808), and R171C (rs201065375), were loss-of-function variants for metabolizing the CES1 substrates clopidogrel, enalapril, and sacubitril. In addition, A158V (rs202121317), R199H (rs2307243), E220G (rs200707504), and T290M (rs202001817) decreased CES1 activity to a lesser extent in a substrate-dependent manner. Several nsSNPs, includingL40Ter (rs151291296), G147C (rs146456965), Y170D (rs148947808), and R171C (rs201065375), significantly reduced CES1 protein and/or mRNA expression levels in the transfected cells. Functions of the common nonsynonymous haplotypes D203E-A269S and S75N-D203E-A269S were evaluated using cells stably expressing the haplotypes and a large set of the human liver. Neither CES1 expression nor activity was affected by the two haplotypes. In summary, this study revealed several functional nsSNPs with impaired activity on the metabolism of CES1 substrate drugs. Clinical investigations are warranted to determine whether these nsSNPs can serve as biomarkers for the prediction of therapeutic outcomes of drugs metabolized by CES1.