Figure 6.

C4, in combination with doxorubicin, was more effective at decreasing tumor growth in neuroblastoma xenografts than either agent alone. A nude mouse model was employed to study the in vivo effects of C4 in combination with doxorubicin. SK-N-AS and SK-N-BE(2) neuroblastoma cells were injected into the right flank of nude mice. Once the tumors measured approximately 100 mm³ (Day 0) the animals (8 mice/group) were randomized to the following groups of intraperitoneal injections: (1) daily vehicle (sterile normal saline); (2) daily reduced dose C4 (40 mg/kg); (3) every 3 days low dose doxorubicin (1 mg/kg); or (4) daily reduced dose C4 (40 mg/kg) plus every 3 days low dose doxorubicin (1 mg/kg). Tumor volumes were measured twice weekly with calipers. (A) In the SK-N-AS xenografts, treatment with C4 or doxorubicin alone did not significantly affect tumor growth. Combination treatment with reduced dosages of both C4 and doxorubicin did result in a significant decrease in tumor growth. (B) Treatment of SK-N-BE(2) xenografts with either reduced dose C4 or low dose doxorubicin alone did not significantly reduce tumor volumes compared to controls. However, when reduced dose C4 was combined with low dose doxorubicin, there was a significant decrease in xenograft growth in the C4 + Dox group compared to controls or either treatment alone. This decreased growth began at the second week and continued for the duration of the study.