[CAS NO. 70476-82-3]  Mitoxantrone (NSC-301739) 2HCl

Mitoxantrone induces DNA fragmentation and the proteolytic cleavage of poly(ADP-ribose) polymerase (PARP), a marker of the activation of caspases, in all the patients studied, demonstrating that the cytotoxic effect of mitoxantrone is due to induction of apoptosis. Mitoxantrone activates NFkappaB and stimulates IkappaBalpha degradation in the promyelocytic leukemia cell line HL60 but not in the variant cells, HL60/MX2 cells, which lack the beta isoform of topoisomerase II and express a truncated alpha isoform that results in an altered subcellular distribution. Mitoxantrone inhibits proliferation of activated PBMCs, B lymphocytes, or antigen-specific T-cell lines (TCLs) stimulated on antigen-presenting cells (APCs) in a dose-dependent manner. Mitoxantrone induces apoptosis of PBMCs, monocytes and DCs at low concentrations, whereas higher doses causes cell lysis.