title: Significantly decreased and more variable expression of major CYPs and UGTs in liver microsomes prepared from HBV-positive human hepatocellular carcinoma and matched pericarcinomatous tissues determined using an isotope label-free UPLC-MS/MS method.
abstract: OBJECTIVE
  To determine the liver expression of cytochrome P450 (CYPs) and uridine 5'-diphosphate-glucuronosyltransferases (UGTs), the major phase I and II metabolism enzymes responsible for clearance and detoxification of drugs, xenobiotic and endogenous substances.
  
  
  METHODS
  A validated isotope label-free method was established for absolute and simultaneous quantification of 9 CYPs (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D, 2E1 and 3A4) and 5 UGTs (1A1, 1A4, 1A6, 1A9 and 2B7) in human liver microsomes using LC-MS/MS.
  
  
  RESULTS
  The LC-MS/MS method displayed excellent dynamic range (at least 250-fold) and high sensitivity for each of the signature peptides with acceptable recovery, accuracy and precision. The protein expression profile of CYP and UGT isoforms were then determined in match microsomes samples prepared from patients with HBV-positive human hepatocellular carcinoma (HCC). In the tumor microsomes, the average absolute amounts of 8 major CYP isoforms (except CYP2C19) and 3 UGT isoforms (UGT1A1, UGT1A4 and UGT2B7) were decreased significantly (p < 0.05), whereas UGT1A6 and UGT1A9 levels were unchanged (p > 0.05). In addition, among isoforms with altered expression, 6 of 8 CYP isoforms and all three UGT isoforms were much more variable in tumor microsomes. Lastly, the importance of CYP3A4 was greatly diminished whereas the importance of UGT1A6 was enhanced in tumor microsomes.
  
  
  CONCLUSIONS
  The use of an isotope label-free absolute quantification method for the simultaneous determination of 9 CYPs and 5 UGTs in human liver microsomes reveals that expression levels of CYPs and UGTs in human liver are severely impact by HCC, which could impact drug metabolism, disposition and pharmacotherapy.
authors.affiliation: International Institute for Translational Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, 510006, China, yantm1988@gmail.com.
authors.forename: Tongmeng
authors.initials: T
authors.lastname: Yan
authors.forename: Song
authors.initials: S
authors.lastname: Gao
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Peng
authors.forename: Jian
authors.initials: J
authors.lastname: Shi
authors.forename: Cong
authors.initials: C
authors.lastname: Xie
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Linlin
authors.initials: L
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Fuyuan
authors.initials: F
authors.lastname: Zhou
authors.forename: Zhongqiu
authors.initials: Z
authors.lastname: Liu
authors.forename: Ming
authors.initials: M
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000201:enzymology* / Q000821:virology*; D002853:Chromatography, Liquid; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis*; D014453:Glucuronosyltransferase / Q000032:analysis*; D006509:Hepatitis B / Q000150:complications*; D006801:Humans; D007527:Isoenzymes; D008113:Liver Neoplasms / Q000201:enzymology* / Q000821:virology*; D008297:Male; D013058:Mass Spectrometry; D008862:Microsomes, Liver / Q000201:enzymology / Q000821:virology; D008875:Middle Aged; D015203:Reproducibility of Results
chemical_list: D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System; D014453:Glucuronosyltransferase