title: Expression of the multi-drug resistance proteins and the pregnane X receptor in treated and untreated retinoblastoma.
abstract: OBJECTIVE
  To compare the expression of pregnane xenobiotic receptor and certain multi-drug resistance proteins in retinoblastoma.
  
  
  METHODS
  Using tissue microarray analyses, we studied 62 pathology specimens for expression of pregnane xenobiotic receptor, multi-drug resistance 1/P glycoprotein, multi-drug resistance proteins 1, 2, and 4, and breast cancer resistant protein.
  
  
  RESULTS
  Comparing tumors treated with primary enucleation with tumors treated with chemotherapy and/or radiation showed no significant differences in the expression of multi-drug resistance proteins or pregnane xenobiotic receptor. Pregnane xenobiotic receptor was correlated with multi-drug resistance protein 2 expression (p < 0.001).
  
  
  CONCLUSIONS
  Our results indicate selection, rather than induction, of chemoresistant cells as a cause for treatment failure in managing retinoblastoma with primary systemic chemotherapy.
authors.affiliation: Hamilton Eye Institute, Department of Ophthalmology, University of Tennessee Health Science Center, USA.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Wilson
authors.forename: Charles H
authors.initials: CH
authors.lastname: Fraga
authors.forename: Carlos
authors.initials: C
authors.lastname: Rodriguez-Galindo
authors.forename: Nikolas
authors.initials: N
authors.lastname: Hagedorn
authors.forename: Markos L
authors.initials: ML
authors.lastname: Leggas
authors.forename: Clinton
authors.initials: C
authors.lastname: Stewart
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D002648:Child; D015331:Cohort Studies; D004358:Drug Therapy; D015353:Eye Enucleation; D015870:Gene Expression; D006801:Humans; D046228:Microarray Analysis; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism; D000077297:Pregnane X Receptor; D011878:Radiotherapy; D011987:Receptors, Steroid / Q000378:metabolism*; D019572:Retinal Neoplasms / Q000378:metabolism* / Q000628:therapy; D012175:Retinoblastoma / Q000378:metabolism* / Q000628:therapy
chemical_list: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D000077297:Pregnane X Receptor; D011987:Receptors, Steroid; C116614:ABCG2 protein, human