The antitumor activity of the platinum complex D-17872 is associated with tumor cell differentiation

Abstract

The novel cisplatin analogue D-17872 was studied for its anticancer activity using in vivo and in vitro preclinical models. The compound at the sublethal dose of 215 mg/kg (ca. 50% of the approximate LD50) induced no nephrotoxic effect strong enough to increase the blood urea level in rats. It had good in vivo antitumor efficacy against murine P388 (max. ILS: D-17872 132%, cisplatin 55%) and L1210 leukemia (max. ILS: D-17872 43%, cisplatin 38%), L5222 leukemia of the rat (max. ILS: D-17872 163%, cisplatin 163%) and murine B16 melanoma. Activity against P388 leukemia substantially exceeded that of cisplatin. Moreover, the M5076 reticulum cell sarcoma implanted into the subrenal capsule and the DMBA-induced mammary tumor of the rat were inhibited by D-17872 to a greater extent than by cisplatin (min. T/C: D-17872 -3%, cisplatin 11%). Using clonogenic microassays, D-17872 was active in vitro against a variety of human and rodent tumor cell lines, albeit at higher concentrations than cisplatin (IC50 values: D-17872 2.6-12.7 mumol/l, cisplatin 0.13-0.42 mumol/l). Apart from its cytotoxic action it was able to induce in vitro differentiation of the human HL-60 and K562 and of the murine M1-T22 cell lines, while cisplatin induced differentiation only in the HL-60 cell line. Thus D-17872 exhibited a pharmacological and toxicological profile different from that of the parent compound. The results suggest that induction of differentiation contributes to the antineoplastic efficacy of this novel cisplatin derivative.

The effect of cisplatin pretreatment on the accumulation of MIBG by neuroblastoma cells in vitro

“…This notion is supported by the observation of a cisplatinprovoked (dose-dependent) stimulation of the transcription of the noradrenaline transporter gene. The latter outcome may be a reflection of the more highly differentiated cellular phenotype which is inducible by cisplatin (Doi et al, 1995;Kumar and Singh, 1995) or cisplatin analogues (Maurer et al, 1993).…”