Cell experiment:

The human breast carcinoma cell lines MDA-MB-231 and MCF-7 are seeded in standard 96-well plates. One day after seeding, the culture medium is changed and replaced by medium containing different concentration of Mitoxantrone (10-5 to 5 μM) with or without DHA (30 μM) during 7 days. Viability of cells are measured as a whole by the tetrazolium salt assay[3].

Animal experiment:

Mice: Mitoxantrone is tested for antitumor activity against experimental tumors in mice and the results are compared with those of seven antitumor antibiotics. The drugs are given IP or IV, in general on days 1, 5, and 9 following tumor inoculation. Mitoxantrone is given IP at the optimal dose (1.6 mg/kg/day; as a free base)[4].

Mitoxantrone is a topoisomerase II inhibitor; also inhibits protein kinase C (PKC) activity with an IC50 of 8.5 μM.

Mitoxantrone inhibits PKC in a competitive manner with respect to histone H1, and its Ki value is 6.3 μM and in a non-competitive manner with respect to phosphatidylserine and ATP[1]. Treatment of B-CLL cells for 48 h with mitoxantrone (0.5 μg/mL) induces a decrease in cell viability. Mitoxantrone induces DNA fragmentation and the proteolytic cleavage of poly(ADP-ribose) polymerase (PARP), demonstrating that the cytotoxic effect of mitoxantrone is due to induction of apoptosis[2]. Mitoxantrone shows cytotoxicity to human breast carcinoma cell lines MDA-MB-231 and MCF-7 with IC50 values of 18 and 196 nM, respectively[3].

Mitoxantrone given IP at the optimal dose (1.6 mg/kg/day; as a free base) produces a statistically significant number of 60-day survivors (curative effect) in mice with IP implanted L1210 leukemia. In SC implanted Lewis lung carcinoma, mitoxantrone and ADM administered IV also shows effective antitumor activities and produces a 60% and a 45% ILS, respectively.[4].

[1]. Takeuchi N, et al. Inhibitory effect of mitoxantrone on activity of protein kinase C and growth of HL60 cells. J Biochem. 1992 Dec;112(6):762-7. [2]. Bellosillo B, et al. Mitoxantrone, a topoisomerase II inhibitor, induces apoptosis of B-chronic lymphocytic leukaemia cells. Br J Haematol. 1998 Jan;100(1):142-6. [3]. Vibet S, et al. Differential subcellular distribution of mitoxantrone in relation to chemosensitization in two human breast cancer cell lines. Drug Metab Dispos. 2007 May;35(5):822-8. [4]. Fujimoto S, et al. Antitumor activity of mitoxantrone against murine experimental tumors: comparative analysis against various antitumor antibiotics. Cancer Chemother Pharmacol. 1982;8(2):157-62.