The thalidomide analogue, CC-4047, induces apoptosis signaling and growth arrest in childhood acute lymphoblastic leukemia cells in vitro and in vivo

Purpose: Thalidomide and its analogues have shown promise in the treatment of multiple myeloma but their therapeutic potential has not been evaluated in models of acute lymphoblastic leukemia (ALL). Experimental Design: We assessed the effects of the thalidomide analogue, CC-4047, on the growth and apoptosis signaling of human B cell precursor (BCP) ALL cell lines and freshly obtained childhood BCP-ALL cells grown with or without stromal cells. In addition, we studied the effects of CC-4047 on the progression and dissemination of xenotransplanted human BCP-ALL cells in nonobese diabetic/severe combined immunodeficiency mice. Results: CC-4047 reduced the proliferation of human BCP-ALL cell lines in vitro. In contrast with the antileukemic effect of cytarabin, this was more pronounced when cell lines or freshly obtained childhood BCP-ALL cells were cocultured with stromal cells. CC-4047 induced the cleavage of caspase-3, caspase-9, and poly(ADP-ribose) polymerase in stroma-cocultured BCP-ALL cells. The inhibition of tumor growth, caspase-3 cleavage, and reduced microvessel density was observed in nonobese diabetic/severe combined immunodeficiency mice inoculated s.c. with childhood BCP-ALL cells upon CC-4047 treatment. After i.v. BCP-ALL xenotransplantation, CC-4047 reduced splenic dissemination. Conclusions: The thalidomide analogue, CC-4047, displays profound cytostatic effects on stroma-supported human ALL cells both in vitro and in vivo.