title: Amplification and expression of mdr1 gene in a multidrug resistant variant of small cell lung cancer cell line NCI-H69.
abstract: Amplification and expression of the mdr1 gene encoding P-glycoprotein have been studied in H69/LX4 a multidrug resistant variant (MDR) of small cell lung cancer (SCLC) cell line NCI-H69. Recently a second independently derived MDR variant of this cell line designated H69/AR was found by others not to show amplification, rearrangement or over-expression of the mdr1 gene. The present study reports that in marked contrast to H69/AR, H69/LX4 shows amplification and expression of the P-glycoprotein gene and raises the possibility that P-glycoprotein hyperexpression may be a clinically relevant component of MDR in some SCLC tumours.
authors.affiliation: MRC Clinical Oncology and Radiotherapeutics Unit, Medical Research Council Centre, Cambridge, UK.
authors.forename: J G
authors.initials: JG
authors.lastname: Reeve
authors.forename: P H
authors.initials: PH
authors.lastname: Rabbitts
authors.forename: P R
authors.initials: PR
authors.lastname: Twentyman
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018288:Carcinoma, Small Cell / Q000235:genetics*; D002460:Cell Line; D004351:Drug Resistance; D005784:Gene Amplification; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D008562:Membrane Glycoproteins / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D008562:Membrane Glycoproteins