HL-60 human leukaemic cell line colonies in agar capillaries: comparison of their reactivity to hormones, cytostatics and selective inhibitors of proliferation.
Colonies of the HL-60 human leukaemic promyelocytic cell line developing in semisolid agar gel capillaries were established. The endogenous inhibitory fraction GI-3, specific for myeloid cells, hydrocortisone and adriamycin decreased colony number in a dose dependent manner. ED50 values amounted to 220, 10(-1) and 4.5 X 10(-3), micrograms/ml respectively. If administered in combination, the endogenous inhibitor, steroid hormone and cytostatic agent exhibited a marked synergism. They affected HL-60 cells additively, and in some cases, a slight potentiation occurred. The experiments demonstrate the possibility of augmenting the inhibitory activity of cytostatics and hormones on leukaemic cells by endogenous inhibitors without an increase in drug toxicity.
D000818:Animals; D001853:Bone Marrow / Q000032:analysis; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004317:Doxorubicin / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism*; D051379:Mice; D012685:Sepharose; D013154:Spleen / Q000032:analysis; D014020:Tissue Extracts / Q000494:pharmacology
D014020:Tissue Extracts; D004317:Doxorubicin; D012685:Sepharose; D006854:Hydrocortisone