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 aD50 value (i.e., the dose producing half the maximal response) of 0.05 μM for MTX and 0.38 μM for 6-TG. For the MTX-resistant subline theD50 value was 8 μM of MTX. Comparisons of the continuous power-time curves showed the inhibitory effect of 6-TG to be faster than that of MTX.
Index EntriesMicrocalorimetry on T-lymphoma cells 6-thioguanine methotrexate methotrexate resistant cells dose-response curves
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