Figure 6. CB₂ agonist inhibits tumor growth in syngenic mouse models.

NT 2.5 cells (2×10⁶ in 100 ul PBS) were implanted orthotopically into mammary gland (#4) of mice. Experimental mice (n = 5) were treated peritumorally either with JWH-015 (5 mg/kg body wt) or vehicle on alternate days for 28 days starting 14 days after injection of the cells. (A) Tumors were measured every wk with external calipers and tumor volume was calculated according to the formula V = 0.52×a ²×b, where a is the smallest superficial diameter and b is the largest superficial diameter. (B) After 28 days, the tumors were excised and weighed. (C) A representative photograph of mice showing tumors dissected from vehicle or JWH-015 treated groups. (D) Representative photomicrographs of immunostaining with Ki67 (proliferation marker) of tumors extracted from JWH-015 treated mice compared to vehicle treated. Scale bars, 50 µm. (E) Tumor lysates from mice treated with JWH or vehicle were analyzed for Phospho-CXCR4 (pCXCR4), CXCR4, Phospho-ERK (pERK), ERK and GAPDH by Immunoblotting. (F) Tumor lysates derived from PyMT transgenic mice treated with JWH or vehicle and analyzed for pERK, ERK, pCXCR4 and CXCR4 by Immunoblotting. *P<0.05 vs. vehicle. Veh: Vehicle.