title: Effect of multidrug-resistant P-glycoprotein gene expression on chloroaluminum tetrasulfonate phthalocyanine concentration.
abstract: The effect of multidrug-resistant P-glycoprotein gene expression (MDR1) in 3T3 cells on cellular concentrations and cytotoxicity induced by the photodynamic agent chloroaluminum tetrasulfonate phthalocyanine (AlSPc) was evaluated. 3T3 cells transfected with a retroviral vector expressing human MDR1 cDNA were resistant to colchicine. Resistant cells incubated with daunomycin accumulated only 40-50% of the quantity of daunomycin accumulated in control cells. Resistant cells incubated with daunomycin in the presence of verapamil had intracellular daunomycin concentrations approximately equal to control cells without verapamil. When these MDR1 3T3 cells were incubated with AlSPc, cellular concentrations of AlSPc did not differ between cells resistant to colchicine and those that were not. Similarly, there was little difference in cytotoxicity demonstrated by 51Cromium release in the two cell lines exposed to AlSPc and light (675 nm; 6 J/cm2). This study suggests photodynamic therapy using AlSPc may be a useful treatment modality for tumors in which the MDR1 P-glycoprotein confers resistance to cancer chemotherapeutics.
authors.affiliation: University of Tennessee College of Veterinary Medicine, Knoxville 37901.
authors.forename: D L
authors.initials: DL
authors.lastname: Frazier
authors.forename: M A
authors.initials: MA
authors.lastname: Barnhill
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: E
authors.initials: E
authors.lastname: Jones
authors.forename: G
authors.initials: G
authors.lastname: Niemeyer
authors.forename: L
authors.initials: L
authors.lastname: Mishu
authors.forename: C D
authors.initials: CD
authors.lastname: Lothrop
mesh_terms: D016475:3T3 Cells; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D003078:Colchicine / Q000494:pharmacology; D003630:Daunorubicin / Q000493:pharmacokinetics; D004351:Drug Resistance / Q000235:genetics*; D015870:Gene Expression; D007211:Indoles / Q000493:pharmacokinetics* / Q000633:toxicity; D007834:Lasers; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D009942:Organometallic Compounds / Q000493:pharmacokinetics* / Q000633:toxicity; D011838:Radiation-Sensitizing Agents / Q000493:pharmacokinetics* / Q000633:toxicity; D014162:Transfection; D014700:Verapamil / Q000494:pharmacology
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002352:Carrier Proteins; D007211:Indoles; D008562:Membrane Glycoproteins; D009942:Organometallic Compounds; D011838:Radiation-Sensitizing Agents; C052736:chloroaluminum tetrasulfophthalocyanine; D014700:Verapamil; D003078:Colchicine; D003630:Daunorubicin