Chemotherapeutic Effects on Mammalian Tumor Cells. III. Modification of Leukemia L1210 Growth Kinetics With an Antimetabolite
Ralph E. Johnson, Walter G. Hardy, Marvin Zelen · JNCI Journal of the National Cancer Institute · 1966
A biologically stable ascites line of Leukemia L1210 was treated with amethopterin under conditions designed to reduce the surviving cells to a minimum number. A mathematical model suggested an alteration of the growth kinetics of these sublethally damaged surviving cells. Bioassay studies on sublines developed from recurrent tumors confirmed a transient decrease in virulence associated with a prolonged tumor doubling time. Cytogenetic studies demonstrated a high frequency of chromatid breaks in sublines derived from amethopterin-treated cells.