title: Characterization and analyses of multidrug resistance-associated protein 1 (MRP1/ABCC1) polymorphisms in Chinese population.
abstract: OBJECTIVE
  To explore the distribution frequencies of four common single nucleotide polymorphisms (SNPs) of MRP1/ABCC1 in a mainland Chinese population and investigate whether these SNPs affect the expression and function of the MRP1/ABCC1.
  
  
  METHODS
  The genotype of 208 healthy volunteers was determined using PCR-restriction fragment length polymorphism. The four candidated SNPs were recreated by site-directed mutagenesis and tested for their effect on MRP1/ABCC1 expression and multidrug resistance function in stable transfected HEK293 and CHO-K1 cell lines. Real-time PCR, western blot and confocal microscopy were used to determine the mRNA, protein expression, and protein trafficking. At last, the effect of mutations on MRP1/ABCC1-mediate drug resistance was determined using methyl thiazolyl tetrazolium assay.
  
  
  RESULTS
  The allelic frequencies of Cys43Ser (128G>C), Thr73Ile (218C>T), Arg723Gln (2168G>A), and Arg1058Gln (3173G>A) in mainland Chinese were 0.5, 1.4, 5.8, and 0.5%, respectively. None of these mutations had any effect on MRP1/ABCC1 expression and trafficking, but that Arg723Gln mutation significantly reduced MRP1/ABCC1-mediated resistance to daunorubicin, doxorubicin, etoposide, vinblastine, and vincristine. The Cys43Ser mutation did not affect all tested drug resistance. In contrast, the Thr73Ile mutation reduced resistance to methotrexate and etoposide, whereas the Arg1058Gln mutation increased the response of two anthracycline drugs and etoposide in HEK293 and CHO-K1 cells as well as vinblastine and methotrexate in CHO-K1 cells.
  
  
  CONCLUSIONS
  The allelic frequency of the Arg723Gln mutation is relatively higher than other SNPs in mainland Chinese population and therefore this mutation significantly reduces MRP1/ABCC1 activity in multidrug resistance.
authors.affiliation: Institute of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, Xiang-Ya Hospital, Central South University, Changsha, Hunan, China. Liuzhaoqian63@126.com
authors.forename: Ji-Ye
authors.initials: JY
authors.lastname: Yin
authors.forename: Qiong
authors.initials: Q
authors.lastname: Huang
authors.forename: Youyun
authors.initials: Y
authors.lastname: Yang
authors.forename: Jian-Ting
authors.initials: JT
authors.lastname: Zhang
authors.forename: Mei-Zuo
authors.initials: MZ
authors.lastname: Zhong
authors.forename: Hong-Hao
authors.initials: HH
authors.lastname: Zhou
authors.forename: Zhao-Qian
authors.initials: ZQ
authors.lastname: Liu
mesh_terms: D000328:Adult; D000818:Animals; D044466:Asian People / Q000235:genetics*; D016466:CHO Cells; D002478:Cells, Cultured; D002681:China; D006224:Cricetinae; D003412:Cricetulus; D018432:Drug Resistance, Multiple / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008957:Models, Genetic; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger; C421109:multidrug resistance-associated protein 1