title: Detection of frequent ABCB1 polymorphisms by high-resolution melting curve analysis and their effect on breast carcinoma prognosis.
abstract: BACKGROUND
  The ABCB1 gene encodes P-glycoprotein implicated in the development of cellular drug resistance. The aim of this study was to develop high-resolution melting (HRM) analysis for determination of ABCB1 polymorphisms and evaluate their associations with clinical data of breast carcinoma patients.
  
  
  METHODS
  HRM analysis was designed to assess five single nucleotide polymorphisms (SNPs) in ABCB1 (rs2214102, rs1128503, rs2032582, rs2032583 and rs1045642) in genomic DNA from 103 breast carcinoma patients. Results were confirmed by direct DNA sequencing.
  
  
  RESULTS
  HRM analysis revealed distinct patterns of melting curves for the respective genotypes of all followed SNPs. Sensitivity of HRM analysis compared with direct DNA sequencing was superior (97.1% vs. 93.9%). The overall accuracy of HRM was 97.6%. The coefficients of variation in replicate experiments encompassed the range 0.002%-0.038%. On the basis of the examined SNPs, one strong haplotype block containing rs2032582 and rs1128503 SNPs was identified. Significant associations of rs2032582 SNP with tumor size, negative HER-2/neu status, and family history of breast carcinoma were found. Patients carrying the ancestral homozygous genotype (GG) in rs2214102 had significantly worse progression-free survival in comparison with carriers of the non-ancestral allele (A) in the adjuvant set (p=0.005).
  
  
  CONCLUSIONS
  A rapid, accurate, low-cost and time-effective method for screening ABCB1 SNPs was developed. Significant associations of ABCB1 rs2032582 and rs2214102 SNPs with prognostic factors and survival of patients were found.
authors.affiliation: Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic. rvaclavikova@szu.cz
authors.forename: Radka
authors.initials: R
authors.lastname: Vaclavikova
authors.forename: Marie
authors.initials: M
authors.lastname: Ehrlichova
authors.forename: Ivona
authors.initials: I
authors.lastname: Hlavata
authors.forename: Vaclav
authors.initials: V
authors.lastname: Pecha
authors.forename: Renata
authors.initials: R
authors.lastname: Kozevnikovova
authors.forename: Marketa
authors.initials: M
authors.lastname: Trnkova
authors.forename: Jan
authors.initials: J
authors.lastname: Adamek
authors.forename: Hege
authors.initials: H
authors.lastname: Edvardsen
authors.forename: Vessela N
authors.initials: VN
authors.lastname: Kristensen
authors.forename: Ivan
authors.initials: I
authors.lastname: Gut
authors.forename: Pavel
authors.initials: P
authors.lastname: Soucek
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000628:therapy; D005260:Female; D006801:Humans; D008875:Middle Aged; D009691:Nucleic Acid Denaturation; D020641:Polymorphism, Single Nucleotide; D011379:Prognosis; D017422:Sequence Analysis, DNA / Q000379:methods*; D044366:Transition Temperature; D016896:Treatment Outcome
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1