title: Characterization of multidrug resistance and monitoring of tumor response by combined 31P and 1H nuclear magnetic resonance spectroscopic analysis.
abstract: A combined 31P and 1H nuclear magnetic resonance (NMR) spectroscopic study was carried out in drug-sensitive and adriamycin- and mitoxantrone-resistant P388 murine leukemic cells. Typical spectral changes characteristic of multidrug resistance were observed in resistant cells compared to drug-sensitive cells. Quantitative comparison of phosphate metabolites ATP, phosphocreatine, phosphomonoesters and phosphodiesters revealed a significant alteration in the metabolism of resistant cells. The elevated levels of energy metabolites supported the energy-dependent process of drug efflux in resistant cells. An increased rate of glycolysis in resistant cells as indicated by the elevated lactate level further supported this. The near total loss of energy metabolites and marked decrease in phospholipid metabolites in sensitive cells upon treatment with drug compared to unaltered metabolite levels in resistant cells suggested that the spectral changes can reveal the subtle differences in tumor response between drug-sensitive and -resistant cells. The results substantiate the potential of this non-invasive method to characterize the multidrug resistance phenotype and monitor tumor response.
authors.affiliation: Department of Microbiology and Tumor Biochemistry, Cancer Institute, Madras, India.
authors.forename: P V
authors.initials: PV
authors.lastname: Venkatesan
authors.forename: K
authors.initials: K
authors.lastname: Saravanan
authors.forename: B
authors.initials: B
authors.lastname: Nagarajan
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D002457:Cell Extracts / Q000737:chemistry; D004317:Doxorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004734:Energy Metabolism / Q000187:drug effects; D005057:Eukaryotic Cells / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008942:Mitoxantrone / Q000494:pharmacology; D010472:Perchlorates; D010725:Phosphocreatine / Q000032:analysis / Q000187:drug effects; D010743:Phospholipids / Q000032:analysis; D010758:Phosphorus; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism
chemical_list: D000903:Antibiotics, Antineoplastic; D000970:Antineoplastic Agents; D002457:Cell Extracts; D010472:Perchlorates; D010743:Phospholipids; D010725:Phosphocreatine; D010758:Phosphorus; D006859:Hydrogen; D004317:Doxorubicin; D000255:Adenosine Triphosphate; D008942:Mitoxantrone