Multidrug resistance phenotype of human BRO melanoma cells transfected with a wild-type human mdr1 complementary DNA

• Published in: Cancer research (Chicago, Ill.) Vol. 50; no. 6; pp. 1779 - 1785
• Main Authors: LINCKE, C. R, VAN DER BLIEK, A. M, SCHUURHUIS, G. J, VAN DER VELDE-KOERTS, T, SMIT, J. J. M, BORST, P
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA American Association for Cancer Research 15.03.1990
• Subjects: Antineoplastic agents; Antineoplastic Agents - pharmacology; ATP-Binding Cassette, Sub-Family B, Member 1; Biological and medical sciences; Biological Transport; BRO cells; Cell Division - drug effects; Cell Line; Cell Membrane - metabolism; Daunorubicin - metabolism; DNA - genetics; drug resistance; Drug Resistance - genetics; General aspects; Humans; Kinetics; Medical sciences; Melanoma; Membrane Glycoproteins - genetics; Nucleic Acid Hybridization; Pharmacology. Drug treatments; Phenotype; Transfection; Tumor Cells, Cultured - cytology; Tumor Cells, Cultured - drug effects; Tumor Cells, Cultured - metabolism; Antineoplastic agent; Human; Cell line; Sensitivity resistance; Transfection; Melanoma; Tumor; Gene expression
• ISSN: 0008-5472; 1538-7445

We have transfected a eukaryotic expression vector containing a mdr1 complementary DNA isolated from normal human liver into human BRO melanoma cells to study the drug-resistant phenotype produced by the exclusive overexpression of normal human mdr1 P-glycoprotein. The drug resistance pattern of mdr1-transfected clones includes relatively high resistance to gramicidin D (about 300-fold), vincristine (about 100-fold), and actinomycin D (about 100-fold) and a lower degree of resistance to doxorubicin (about 10-fold), VP16-213 (about 10-fold), and colchicine (about 6-fold). The transfectants did not exhibit resistance to trimetrexate, cis-platinum, mitomycin C, 1-beta-D-arabinofuranosylcytosine, bleomycin, G418, or magainin-2-amide; they were slightly more sensitive to verapamil (2-fold) but not to Triton X-100. As in other multidrug-resistant cell lines, resistance to vincristine could be reversed by verapamil and, more effectively, by cyclosporin A. Chloroquine only marginally increased drug sensitivity in mdr1-transfected cells. Gramicidin D resistance was also reversed by verapamil, suggesting that the mechanism of resistance to this polypeptide antibiotic is similar to that of other drugs transported by P-glycoprotein. Thus, expression of the wild-type mdr1 complementary DNA induces a drug-resistant phenotype similar to that induced by mdr1 complementary DNAs isolated from drug-resistant cell lines with relatively low colchicine resistance. As other cell lines may display a different pattern of drug resistance, it is clear that other resistance mechanisms or cell type-specific factors may modulate the resistance. mdr1-transfected cell lines provide a convenient tool for the identification of P-glycoprotein-mediated phenomena.