Effects of Dintrato(1,2-diaminocyclohexane)platinum (NSC 239851) On murine myeloma and hemopoietic precursor cells.

We studied the effects of dinitrato (1,2,-diaminocyclohexane)platinum (NSC 239851) on murine myeloma Adj. PC-5 and hemopoietic precursor cells. The median survival time of tumor-bearing mice was significantly affected by i.p. injections of this agent. While 14 mg/kg was a toxic dose, as little as 2 mg/kg prolonged the survival for over 100 days. When cells from normal marrow and actively regenerating marrows were exposed to the agent in culture tubes, washed, and assayed for the surviving hemopoietic precursors, similar sensitivity curves were observed. This result indicates the absence of cell cycle dependency of the agent. When marrow cells were exposed to NSC 239851 at 4 degrees in culture, almost total abrogation of the cytotoxicity was noted. This observation, unlike that from the experiment with the inorganic platinum congener, cis-diamminedichloroplatinum, suggests that the transport of this agents is an active process.