title: The expression profile of ATP-binding cassette transporter genes in breast carcinoma.
abstract: OBJECTIVE
  ATP-binding cassette (ABC) transporters contribute to development of resistance to anticancer drugs via ATP-dependent drug efflux. A major goal of our study was to investigate associations between the expression of ABC transporters and outcome of breast carcinoma patients.
  
  
  METHODS
  Transcript levels of all 49 human ABC transporters were determined in post-treatment tumor and non-neoplastic tissue samples from 68 breast carcinoma patients treated by neoadjuvant chemotherapy. Six ABC transporters were then evaluated in independent series of 100 pretreatment patients.
  
  
  RESULTS
  ABCA5/6/8/9/10, ABCB1/5/11, ABCC6/9, ABCD2/4, ABCG5 and ABCG8 were significantly downregulated and ABCA2/3/7/12, ABCB2/3/8/9/10, ABCC1/4/5/10/11/12, ABCD1/3, ABCE1, ABCF1/2/3 and ABCG1 were upregulated in post-treatment tumors compared with non-neoplastic tissues. Significant associations of intratumoral levels of ABCC1 and ABCC8 with grade and expression of hormonal receptors were found in both sets of patients. ABCA12, ABCA13 and ABCD2 levels were significantly associated with the response to neoadjuvant chemotherapy in post-treatment patients. Protein expression of ABCA12, ABCC8 and ABCD2 in tumor tissues of patients with breast carcinoma was observed by immunoblotting for the first time.
  
  
  CONCLUSIONS
  ABCA12, ABCA13, ABCC1, ABCC8 and ABCD2 present potential modifiers of progression and response to the chemotherapy of breast carcinoma.
authors.affiliation: Toxicogenomics Unit, National Institute of Public Health, Prague, Czech Republic.
authors.forename: Viktor
authors.initials: V
authors.lastname: Hlaváč
authors.forename: Veronika
authors.initials: V
authors.lastname: Brynychová
authors.forename: Radka
authors.initials: R
authors.lastname: Václavíková
authors.forename: Marie
authors.initials: M
authors.lastname: Ehrlichová
authors.forename: David
authors.initials: D
authors.lastname: Vrána
authors.forename: Václav
authors.initials: V
authors.lastname: Pecha
authors.forename: Renata
authors.initials: R
authors.lastname: Koževnikovová
authors.forename: Markéta
authors.initials: M
authors.lastname: Trnková
authors.forename: Jiří
authors.initials: J
authors.lastname: Gatěk
authors.forename: Dana
authors.initials: D
authors.lastname: Kopperová
authors.forename: Ivan
authors.initials: I
authors.lastname: Gut
authors.forename: Pavel
authors.initials: P
authors.lastname: Souček
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000970:Antineoplastic Agents / Q000008:administration & dosage; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D002277:Carcinoma / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D056726:Genetic Association Studies; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy
chemical_list: D018528:ATP-Binding Cassette Transporters; D000970:Antineoplastic Agents