nogalamycin and Melanoma

Topics: Adult; Aged; Antineoplastic Agents; Daunorubicin; Drug Evaluation; Female; Humans; Infusions, Intravenous; Male; Melanoma; Menogaril; Middle Aged; Nogalamycin; Skin Neoplasms

Menogarol is a new anthracycline undergoing phase I clinical trial. We report here the lethality after 2 hr exposure to 2 drug combinations of menogarol and several antitumor agents. A new statistical procedure was used to identify synergistic combinations. Most of these combinations were additive, except for menogarol plus melphalan, which was synergistic. Adriamycin plus melphalan was also synergistic. The menogarol-melphalan combination wa studied in detail with regard to the effect of dose and drug-schedule, lethality for exponential and plateau phase cells and effect on cell cycle progression. Although the combination was synergistic for exponential cells it was additive for plateau phase cells. The combination exerted a synergistic effect in inhibiting progression of cells through the cell cycle. After 2 hr menogarol exposure cells were blocked in G2 for about 12 hr following which the block was reversed. This reversal was inhibited when menogarol was combined with melphalan. The uptake of menogarol or melphalan was not changed in the presence of the other drug.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Cell Division; Cell Survival; Cells, Cultured; Daunorubicin; Doxorubicin; Drug Synergism; Melanoma; Melphalan; Menogaril; Mice; Nogalamycin

Nogalamycin is an anthracycline antibiotic which was markedly cytotoxic in vitro and was active against several tumor systems in vivo. We compare here the lethality of several nogalamycin analogs against Chinese hamster ovary (CHO), mouse leukemia (L1210), and mouse melanoma (B16) cells in culture. 7-con-O-Methylnogarol (7-con-OMEN) was the most lethal of all the analogs tested. Thus, for CHO cells exposed for two hr to the drug, the 50% lethal doses of 7-con-OMEN, nogalamycin, and dis-nogamycin were 0.25, 2.7, and 5.8 micrograms/ml, respectively. In general, CHO cells were less sensitive than B16 or L1210 cells to most compounds. All compounds gave dose-survival curves which consisted of a shoulder region followed by a region of exponential decline in survival. The nogalamycin analogs nogalamycin, dis-nogamycin, 7-con-O-methylnogalarol, and 7-con-OMEN were selected for further study because of their greater lethality in vitro and antitumor activity in vivo. The lethality of these compounds was compared to that of Adriamycin. 7-con-OMEN was more toxic to CHO cells than was Adriamycin but was less toxic to B16 and L1210 cells. All of these compounds (except 7-con-O-methylnogalarol which was not tested) were more lethal to exponentially growing cells than to plateau-phase cells. The survival response after different periods of exposure to these drugs was compared. In order to make valid comparisons of the time-survival response to different drugs, the drug concentrations chosen were such that they were equitoxic after a two-hr exposure. Under these conditions, the order of lethality after long-term exposure (8 hr to 24 hr) was nogalamycin > dis-nogamycin > 7-con-OMEN, Adriamycin > 7-con-O-methylnogalarol. With all the drugs, the rate of cell death increased with increasing drug concentrations.

Topics: Animals; Cell Survival; Cells, Cultured; Cricetinae; Daunorubicin; Dose-Response Relationship, Drug; Doxorubicin; Female; Kinetics; Leukemia L1210; Melanoma; Mice; Neoplasms, Experimental; Nogalamycin; Ovary