Figure 7. Thrombocytopenia favors the accumulation of microspheres and increases the efficacy of paclitaxel on LLC tumor growth.

A, Dorsal skinfold chambers were surgically implanted on the backs of C57BL/6 mice. Two days later, LLC tumor cells were injected within skinfold chamber and allowed to grow. At day 5, mice were treated with either a control antibody (Control) or a platelet depleting antibody (Depleted) and 100×10⁶ 1μm fluorescent microspheres. Photographs of a control and a thrombocytopenic tumor were taken at 24 hours after platelet depletion. Original magnification 40X, Bar = 200μm. Results are representative of 3 different hemorrhagic tumors and nonhemorrhagic tumors. B, LLC tumor-bearing mice were treated on day 8 (arrow) as indicated and tumor growth was monitored. Tumor growth is represented as the ratio of the tumor volume at a specific day (V1) to the tumor volume before treatment (V0). At day 11 and 14, a significant reduction in tumor growth was observed in thrombocytopenic tumor bearing-mice receiving chemotherapy compared to mice with normal platelet count treated with paclitaxel alone (n=8-9 mice per group; * p ≤ 0.05).