title: Anticancer drugs: effect on the cloning of Raji lymphoma cells in soft agar.
abstract: The effect of 11 anticancer drugs on the ability of Raji lymphoma cells to form colonies in soft agar was determined with the use of both a 1-hour and a continuous drug exposure. Three distinct patterns of drug sensitivities were observed: a) Dactinomycin, adriamycin, bleomycin, mitomycin C, vincristine, and cis-platinum II all produced a dose-dependent reduction in colony formation following a 1-hour exposure, which was further augmented by a continuous exposure to the drugs; b) the antimetabolites (methotrexate, beta-cytosine arabinoside, and 5-fluorouracil) and pentamethylmelamine had no suppressive effects on colony formation with a 1-hour exposure, but they produced marked cytotoxicity with continuous drug exposure; and c) L-phenylalanine mustard had the same degree of colony suppression with both a 1-hour and a continuous drug exposure. Preincubation of Raji cells with an enzyme mixture (DNase + pronase + collagenase) did not alter the degree of colony suppression observed with the anticancer drugs. These results indicate that continuous drug exposure should be compared to a 1-hour drug incubation to determine in vitro drug sensitivities of fresh human tumors in the soft agar clonogenic assay, because the 1-hour drug exposure may not identify certain drugs that are potentially clinically active.
mesh_terms: D000362:Agar; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D006801:Humans; D008223:Lymphoma / Q000188:drug therapy / Q000473:pathology*; D013997:Time Factors
chemical_list: D000970:Antineoplastic Agents; D000362:Agar