Summary
The effect of methotrexate (amethopterin) upon the MMT cell line was studied by time-lapse microcinematography, the plasma levels obtained after systemic administration of maximum tolerated doses of the drug in man being simulated in vitro. Cells in the logarithmic growth phase (large growth fraction population) were widely affected, although enough drug-resistant cells remained to regenerate the cell colony. Cells in the preconfluent growth phase (small growth fraction population) were less effected, because many cells were arrested at the G0-phase, ouside the cell cycle. A drug-resistant colony always developed, making the drug therapy useless. The experiments showed that rescue treatment with leucovorin (citrovorum factor of folinic acid) was not effective either, because, at least on our experimental conditions, recovery of the mitotic activity was more rapid and the number of degenerating cells smaller with rescue treatment than with the conventional treatment. The results also suggested a new mechanism of methotrexate action in addition to the classic one of folic acid inhibition, which might consist in the inhibition of the production of formyl-methionyl-tRNA, part of the initiation complex in protein biosynthesis.
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References
Bleyer WA (1977) Methotrexate: clinical pharmacology, current status and therapeutic guidelines. Cancer Treat Rev 4:87–101
Delmonte L, Jukes TH (1962) Folic acid antagonists in cancer chemotherapy. Pharm Rev 14:91
Gey GO, Coffman WD, Kubiceck MT (1952) Tissue culture studies of the proliferative capacity of cervical carcinoma and normal epithelium. Cancer Res 12:264–265
Goldin A, Venditti JM, Kline I, Mantel N (1966) Eradication of leukemia cells (L 1210) by methotrexate plus citrovorum factor. Nature 212:1548
Howard, A, Pelc SR (1951) Nuclear incorporation of P-32 as demonstrated by autoradiographs. Exp Cell Res 2:178–187
Howard A, Pelc SR (1953) Synthesis of desoxyribonucleic acid in normal and irradiated cells and its relation to chromosome breakage. Heredity (Suppl) 6:261–273
Lala PK (1971) Studies on tumor cell population kinetics. In: Busch H. (ed) Methods in cancer research, vol 6. Academic Press, New York London, p 3–87
Mazia D (1974) The cell cycle. Scientific American 1:54–63
Nowell PC (1976) Clonal evolution of tumor cell populations. Science 194:23
Pratt CB, Roberts D, Shanks E, Warmath EL (1975) Response, toxicity, and pharmacokinetics of high-dose methotrexate (NSC-740) with citrovorum factor (NSC-3590) rescue for children with osteosarcoma and other malignant tumors. Cancer Chemother Rep [3] 6:13–18
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Coordinated center of the Consejo Superior de Investigaciones Cientificas, Madrid
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Alvarez-Rodríguez, Y., Ruano, A. & Valladares, Y. Microcinematographic study on the effect of methotrexate upon mouse mammary tumor cells (MMT cell line). Cancer Chemother. Pharmacol. 4, 53–60 (1980). https://doi.org/10.1007/BF00255460
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DOI: https://doi.org/10.1007/BF00255460