A multidrug-resistant cell such as the human lymphoblastic leukemic cell CEM/VLB100 accumulates far less vinblastine (VLB) than its drug-sensitive parent, CEM. When CEM/VLB100 cells are exposed to liposomes consisting of the phospholipids cardiolipin, dioleoylphosphatidic acid, or phosphatidylinositol bearing unsaturated fatty acids and then tested for uptake of VLB, accumulation of drug rapidly rises to levels approaching those of CEM cells, which are relatively unaffected by the liposome treatment. The liposomes are not carriers of entrapped drug. Phosphatidylserine, phosphatidylcholine, and phosphatidylethanolamine are inactive, and the addition of cholesterol to liposomes inhibits uptake. Exposure of cells to liposomes does not appear to alter the efflux of drugs. We suggest that the liposomal lipids, introduced into the plasma membranes of CEM/VLB100 cells, change their properties so that accumulation of drugs by cells is largely restored. The cytotoxicity of VLB in CEM/VLB100 cells is increased approximately 10-fold by cardiolipin liposomes.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Selective cellular uptake and retention of SN 28049, a new DNA-binding topoisomerase II-directed antitumor agent.
Cancer Chemother Pharmacol
July 2014
Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
Purpose: SN 28049 is a new DNA-binding topoisomerase II poison identified by its curative activity against the murine colon 38 carcinoma. Previous studies showed activity to be associated with selective drug accumulation and retention in tumour tissue. Retention varied widely among different tumours and was related to antitumour activity.
View Article and Find Full Text PDFStructure-activity relationship and molecular mechanisms of ethyl 2-amino-6-(3,5-dimethoxyphenyl)-4-(2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (CXL017) and its analogues.
J Med Chem
August 2011
Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, 308 Harvard Street SE, Minneapolis, Minnesota 55455, USA.
Multidrug resistance (MDR) in cancer is a phenomenon in which administration of a single chemotherapeutic agent causes cross-resistance of cancer cells to a variety of therapies even with different mechanisms of action. Development of MDR against standard therapies is a major challenge in the treatment of cancer. Previously we have demonstrated a unique ability of CXL017 (5) to selectively target MDR cancer cells and synergize with mitoxantrone (MX) in HL60/MX2 MDR cells.
View Article and Find Full Text PDFTRAIL sensitize MDR cells to MDR-related drugs by down-regulation of P-glycoprotein through inhibition of DNA-PKcs/Akt/GSK-3beta pathway and activation of caspases.
Mol Cancer
July 2010
Department of Biochemistry, Pusan National University School of Medicine, Yangsan, South Korea.
Background: The development of new modulator possessing high efficacy, low toxicity and high selectivity is a pivotal approach to overcome P-glycoprotein (P-gp) mediated multidrug resistance (MDR) in cancer treatment. In this study, we suggest a new molecular mechanism that TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) down-regulates P-glycoprotein (P-gp) through inhibition of DNA-PKcs/Akt/GSK-3beta pathway and activation of caspases and thereby sensitize MDR cells to MDR-related drugs.
Results: MDR variants, CEM/VLB10-2, CEM/VLB55-8 and CEM/VLB100 cells, with gradually increased levels of P-gp derived from human lymphoblastic leukemia CEM cells, were gradually more susceptible to TRAIL-induced apoptosis and cytotoxicity than parental CEM cells.
Alterations in gamma-actin and tubulin-targeted drug resistance in childhood leukemia.
J Natl Cancer Inst
October 2006
Children's Cancer Institute Australia for Medical Research, PO Box 81, Randwick NSW 2031, Australia.
Background: Proteomic investigations have revealed alterations in cytoskeletal proteins expressed in human acute lymphoblastic leukemia cells that are resistant to microtubule-disrupting agents. We characterized gamma-actin expression in antimicrotubule drug-resistant leukemia and examined the effect of altered gamma-actin in resistance of acute lymphoblastic leukemia to antimicrotubule agents.
Methods: Two-dimensional polyacrylamide gel electrophoresis and mass spectrometry were used to identify actin proteins in human acute lymphoblastic leukemia cell lines resistant to vinblastine (CCRF-CEM/VLB100 cells) and desoxyepothilone B (CCRF-CEM/dEpoB140 cells).
Drug-resistant T-lymphoid tumors undergo apoptosis selectively in response to an antimicrotubule agent, EM011.
Blood
March 2006
Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA.
We have shown previously that EM011, a synthetic compound, binds tubulin with a higher affinity than the founding compound, noscapine, without changing total microtubule polymer mass. Now we show that EM011 is potently effective against vinblastine-resistant human lymphoblastoid line CEM/VLB100 and its parental vinblastine-sensitive line CEM. The cytotoxicity is mediated by cell cycle arrest at G2/M phase and subsequent apoptosis, as indicated by altered plasma membrane asymmetry, loss of mitochondrial transmembrane potential, activation of caspase-3, and increased DNA fragmentation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!