RT Journal Article SR Electronic T1 FUNCTIONAL CHARACTERIZATION OF THREE NATURALLY OCCURRING SINGLE NUCLEOTIDE POLYMORPHISMS IN THE CES2 GENE ENCODING CARBOXYLESTERASE 2 (HCE-2) JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1482 OP 1487 DO 10.1124/dmd.105.005587 VO 33 IS 10 A1 Takashi Kubo A1 Su-Ryang Kim A1 Kimie Sai A1 Yoshiro Saito A1 Toshiharu Nakajima A1 Kenji Matsumoto A1 Hirohisa Saito A1 Kuniaki Shirao A1 Noboru Yamamoto A1 Hironobu Minami A1 Atsushi Ohtsu A1 Teruhiko Yoshida A1 Nagahiro Saijo A1 Yasuo Ohno A1 Shogo Ozawa A1 Jun-ichi Sawada YR 2005 UL http://dmd.aspetjournals.org/content/33/10/1482.abstract AB Twelve single nucleotide polymorphisms (SNPs) in the human CES2 gene, which encodes a carboxylesterase, hCE-2 [human carboxylesterase 2 (EC 3.1.1.1)], have been reported in the Japanese [S. R. Kim, T. Nakamura, Y. Saito, K. Sai, T. Nakajima, H. Saito, K. Shirao, H. Minami, A. Ohtsu, T. Yoshida, et al. (2003) Drug Metab Pharmacokinet 18:327–332). In this report, we have examined functional alterations of three SNPs, a nonsynonymous SNP (100C>T, R34W), an SNP at the splice acceptor site in intron 8 (IVS8-2A>G), and one newly discovered nonsynonymous SNP (424G>A, V142M). For the two nonsynonymous SNPs, the corresponding variant cDNAs were expressed in COS-1 cells. Both the R34W and V142M variants showed little esterase activities toward the anticancer agent irinotecan and two typical carboxylesterase substrates, p-nitrophenol acetate and 4-methylumbelliferyl acetate, although increased levels of cDNA-mediated protein expression were observed by Western blotting as compared with the wild type. To investigate a possible splicing aberration in IVS8-2A>G, an in vitro splicing assay was utilized and transcripts derived from CES2 gene fragments of the wild type and IVS8-2A>G were compared. Sequence analysis of the cloned transcripts revealed that IVS8-2A>G yielded mostly aberrantly spliced transcripts, including a deleted exon or a 32-bp deletion proximal to the 5′ end of exon 9, which resulted in truncated hCE-2 proteins. These results suggested that 100C>T (R34W), 424G>A (V142M), and IVS8-2A>G are functionally deficient SNPs. The American Society for Pharmacology and Experimental Therapeutics