title: Polymorphisms of the UDP-glucuronosyl transferase 1A genes are associated with adverse events in cancer patients receiving irinotecan-based chemotherapy.
abstract: A prodrug, irinotecan (CPT-11), is a semisynthetic derivative of camptothecin.  It inhibits topoisomerase I and is used for treatment of lung, stomach, and colon cancers in Japan.  The active form of CPT-11, SN-38, causes the adverse events such as neutropenia and diarrhea.  Since SN-38 is metabolized to non-toxic SN-38-glucuronide by hepatic uridine diphosphate glucuronosyl transferase (UGT) 1A enzymes, UGT1A enzyme activities may influence adverse events of CPT-11.  UGT1A enzymes consist of three isozymes (1A1, 1A7, 1A9), and their genes are characterized by polymorphisms.  Here, to identify the genetic factors that affect the adverse events of CPT-11, we determined the polymorphism in three UGT 1A isozyme genes in 45 inpatients with lung, colon, or stomach cancer.  The univariate and multivariate analysis of patients' physiological and genetic factors revealed that one or more genotypes of UGT1A1*6/*28, UGT1A7*3/*3, and UGT1A9*1/*1 may enhance the adverse events.  Each of the first two genotypes is expected to generate the enzyme with low catalytic activity.  The UGT1A9*1 represents the wild-type allele, which however provides the lower catalytic activity, compared to the UGT1A9*22 variant that is common in this study population.  Indeed, four (67%) out of six patients who carry one or more of the above-mentioned genotypes suffered from adverse events, leading to the discontinuation of chemotherapy or the decreased dose of CPT-11.  By contrast, only six (15%) out of 39 patients with other genotypes suffered from adverse events.  In conclusion, UGT1A1*6/*28, UGT1A7*3/*3, and UGT1A9*1/*1 should be taken into consideration as markers for preventing severe adverse events of CPT-11 administration.
authors.affiliation: Department of Clinical Pharmacology and Genetics, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka City, Shizuoka, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Inoue
authors.forename: Momoyo
authors.initials: M
authors.lastname: Sonobe
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Kawamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Etoh
authors.forename: Masakazu
authors.initials: M
authors.lastname: Takagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsumura
authors.forename: Masataka
authors.initials: M
authors.lastname: Kikuyama
authors.forename: Midori
authors.initials: M
authors.lastname: Kimura
authors.forename: Sato
authors.initials: S
authors.lastname: Minami
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Utsuki
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Takayo
authors.initials: T
authors.lastname: Suzuki
authors.forename: Daiki
authors.initials: D
authors.lastname: Tsuji
authors.forename: Hideki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Itoh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects*; D002166:Camptothecin / Q000009:adverse effects / Q000031:analogs & derivatives*; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D003967:Diarrhea / Q000139:chemically induced; D064420:Drug-Related Side Effects and Adverse Reactions / Q000209:etiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D014453:Glucuronosyltransferase / Q000235:genetics*; D006801:Humans; D000077146:Irinotecan; D007527:Isoenzymes; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D009503:Neutropenia / Q000139:chemically induced; D010597:Pharmacogenetics; D011110:Polymorphism, Genetic; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D000099148:UGT1A1 Enzyme
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002166:Camptothecin; D014453:Glucuronosyltransferase; D000077146:Irinotecan; D007527:Isoenzymes; D000099148:UGT1A1 Enzyme