Functional Characterization of 21 Allelic Variants of Dihydropyrimidine Dehydrogenase Identified in 1070 Japanese Individuals.

摘要: Dihydropyrimidine dehydrogenase (DPD, EC 1.3.1.2), encoded by the DPYD gene, is rate-limiting enzyme in degradation pathway of endogenous pyrimidine and fluoropyrimidine drugs such as 5-fluorouracil (5-FU). DPD catalyzes reduction uracil, thymine, 5-FU. In Caucasians, mutations, including DPYD*2A, DPYD*13, c.2846A>T, c.1129-5923C>G/hapB3, are known to contribute interindividual variations toxicity 5-FU; however, none these polymorphisms has been identified Asian population. Recently, 21 allelic variants, some novel single-nucleotide variants (SNVs), were 1070 healthy Japanese individuals analyzing their whole-genome sequences (WGSs), but functional alterations caused remain unknown. this study, vitro analysis was performed on 22 transiently expressing wild-type 293FT cells characterizing enzymatic activities using 5-FU a substrate. expression levels dimeric forms determined immunoblotting blue-native PAGE, respectively. Additionally, values three kinetic parameters-the Michaelis constant (Km ), maximum velocity (Vmax intrinsic clearance (CLint = Vmax/Km )-were for Eleven exhibited significantly decreased compared with DPD. Moreover, band patterns observed immunoblots gels indicated that dimerization required activity Thus, detection rare might facilitate severe adverse effect prediction 5-FU-based chemotherapy