Modulation of choline kinase activity in human cancer cells observed by dynamic 31P NMR.
Choline metabolites are widely studied in cancer research as biomarkers of malignancy and as indicators of therapeutic response. However, endogenous phosphocholine levels are determined by a number of processes that confound the interpretation of these measurements, including membrane transport rates and a series of enzyme catalysed reactions in the Kennedy pathway. Employing a dynamic (31)P NMR assay that is specific to choline kinase (ChoK) we have measured the rates of this enzyme reaction in cell lysates of MDA-MB-231 breast, PC-3 prostate and HeLa cervical cancer cells and in solutions of purified human ChoK. The rates are sensitive to inhibition by hemicholinium-3 (HC-3), a competitive ChoK inhibitor, and to N-[2-bromocinnamyl(amino)ethyl]-5-isoquinolinesulphonamide (H-89), an agent commercialized as a specific cyclic-AMP-dependent protein kinase A (PKA) inhibitor.
Gabellieri
Cristina
C
Cancer Research UK Clinical Magnetic Resonance Research Group, The Institute of Cancer Research, Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey, SM2 5PT, UK.
Beloueche-Babari
Mounia
M
Jamin
Yann
Y
Payne
Geoffrey S
GS
Leach
Martin O
MO
Eykyn
Thomas R
TR
D045744:Cell Line, Tumor; D002797:Choline Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D009369:Neoplasms / Q000201:enzymology* / Q000473:pathology; D010759:Phosphorus Isotopes; D010766:Phosphorylation / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D013997:Time Factors
D007546:Isoquinolines; D010759:Phosphorus Isotopes; D013449:Sulfonamides; D002797:Choline Kinase; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide