Figure 4

Anti-tumor effect and up-regulation of tumor associated human TSP1 mRNA levels in tasquinimod treated LNCaP tumors. Anti-tumor effect in nude mice carrying subcutaneous LNCaP tumors treated with tasquinimod (10 mg/kg/day) for three weeks. The treatment started 7 days after inoculation, and expressed data represent the mean tumor weight ± SD (n = 5; p = 0.0076, ANOVA). (B) VEGF levels were measured in processed tumor tissue by ELISA. (C) Up-regulation, monitored with real-time qRT-PCR, of tumor associated human TSP1 mRNA levels ((i); p = 0.0216, ANOVA) in LNCaP tumors. To distinguish between mRNA from human tumor cells and infiltrating mouse cells, TSP1 mRNA was analyzed using primers specific for human (i) or mouse (ii) sequences with the same probe set (Table 2). (D) Elevated protein levels of tumor-produced human TSP1 (rabbit polyclonal Ab8). Each lane represents a tumor sample from an individual animal. Calculated ratios between the major band of intact TSP1 (approximately at 150-160 kD) and actin in each lane show a significant (p = 0.0004, ANOVA) up-regulation of TSP1 tumor levels in exposed animals ((+); n = 4) compared to untreated controls (-). (*) p ≤ 0.05 and (**) p ≤ 0.01 (Bonferroni's multiple comparison test). (E) TSP1 expression (green) analyzed by IHC microscopy in LNCaP tumor tissue exposed in vivo to tasquinimod at 10 mg/kg/day (bar = 50 μm). TSP1 was mainly localized in the extra cellular matrix (inset). Blue shows DAPI staining.