Microcalorimetric evaluation of the effects of methotrexate and 6-thioguanine on sensitive T-lymphoma cells and on a methotrexate-resistant subline.
Isothermal microcalorimetry was used in order to continuously monitor and quantitatively assess the action of two antineoplastic drugs, methotrexate (MTX) and 6-thioguanine (6-TG), on a human T-lymphoma cell line, CCRF-CEM. The results with MTX were compared with data from experiments with a MTX-resistant subline, CEM/MTX. The slope of the power-time curve after drug injection relative to that obtained during unperturbed growth, was used to construct dose-response curves. The normal cell line was characterized by a D50 value (i.e., the dose producing half the maximal response) of 0.05 microM for MTX and 0.38 microM for 6-TG. For the MTX-resistant subline the D50 value was 8 microM of MTX. Comparisons of the continuous power-time curves showed the inhibitory effect of 6-TG to be faster than that of MTX.
Bermudez
J
J
Facultat d'Odontologia, Universitat de Barcelona, Feixa Llarga, Spain.
Bäckman
P
P
Schön
A
A
D002151:Calorimetry; D002452:Cell Count; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D006801:Humans; D016399:Lymphoma, T-Cell / Q000188:drug therapy / Q000473:pathology*; D008727:Methotrexate / Q000494:pharmacology* / Q000627:therapeutic use; D008832:Microchemistry; D013866:Thioguanine / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors; D014407:Tumor Cells, Cultured
D013866:Thioguanine; D008727:Methotrexate