title: Effect of 22 Novel Cytochrome P450 2D6 (CYP2D6) Variants Found in the Chinese Population on Hemangeol Metabolism In Vitro.
abstract: OBJECTIVE
  Hemangeol, approved for the treatment of proliferative infantile hemangiomas requiring systemic therapy, is metabolized by cytochrome P450 2D6 (CYP2D6), which is a highly polymorphic enzyme that metabolizes a large number of drugs. More than 100 CYP2D6 allelic variants have been reported so far, including 22 novel variants that discovered in our lab in the Chinese population. Our study aimed to probe the enzymatic activity of these variants toward hemangeol in vitro with recombinant microsomes that expressed in sf21 insect cells using a baculovirus-mediated expression system.
  
  
  METHODS
  The wild-type CYP2D6.1 and other variants (CYP2D6.2, CYP2D6.10 and 22 novel CYP2D6 variants) were incubated with 1-200 μM hemangeol for 50 min at 37 °C. Then the products were extracted, and signal detection was performed by high-performance liquid chromatography with fluorescence detector.
  
  
  RESULTS
  All of the variants exhibited changed apparent Michaelis-Menten constant (Km) or maximum velocity of the reaction (Vmax) values compared with that of wild-type protein. The intrinsic clearances (Vmax/Km) were significantly decreased by 0.37 to 42.74 %. However, CYP2D6.92 and CYP2D6.96 showed no or minimal enzymatic activity as no concentration of 4'-hydroxypropranolol was detected.
  
  
  CONCLUSIONS
  The comprehensive in vitro assessment of CYP2D6 variants provides significant insights into allele-specific activity towards hemangeol in vivo.
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, People's Republic of China.
authors.forename: Bingqing
authors.initials: B
authors.lastname: Liang
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, People's Republic of China.
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, People's Republic of China.
authors.forename: Xiangxin
authors.initials: X
authors.lastname: Huang
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, People's Republic of China.
authors.forename: Ermin
authors.initials: E
authors.lastname: Gu
authors.affiliation: The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, Beijing, 100730, People's Republic of China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Dai
authors.affiliation: The Key Laboratory of Geriatrics, Beijing Hospital and Beijing Institute of Geriatrics, Ministry of Health, Beijing, 100730, People's Republic of China. caijp61@vip.sina.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Cai
authors.affiliation: School of Pharmacy, Wenzhou Medical University, Wenzhou, 325035, Zhejiang, People's Republic of China. hgx@wmu.edu.cn.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Hu
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000378:metabolism*; D000483:Alleles; D020533:Angiogenesis Inhibitors / Q000378:metabolism*; D000818:Animals; D044466:Asian People; D055162:Biocatalysis; D001711:Biotransformation; D002681:China; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics* / Q000378:metabolism; D056726:Genetic Association Studies; D006801:Humans; D006900:Hydroxylation; D008861:Microsomes / Q000201:enzymology / Q000378:metabolism; D009154:Mutation; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D011433:Propranolol / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D061987:Sf9 Cells; D018411:Spodoptera; D013379:Substrate Specificity; D014665:Vasodilator Agents / Q000378:metabolism*
chemical_list: D000319:Adrenergic beta-Antagonists; D020533:Angiogenesis Inhibitors; D011994:Recombinant Proteins; D014665:Vasodilator Agents; D011433:Propranolol; D019389:Cytochrome P-450 CYP2D6