Fig. 6: CHIR99021 treatment blocks tumor growth in xenografts and improves overall survival of genetic melanoma mouse models.
a Experimental scheme of injection of the MAPK inhibitor resistant human melanoma cell culture M11 into both flanks of immunocompromised mice. Subsequent i.p. treatment with vehicle (Captisol) or CHIR99021 (n = 4/treatment group). b Tumor growth kinetics with (n = 4) and without (n = 4) CHIR99021 treatment in xenografts established from the MAPK inhibitor resistant human melanoma cell culture M11. c Representative histologic analysis (n = 8) of H&E, Ki67 and Cleaved Caspase 3 stainings of patient-derived xenografts treated with vehicle (Captisol) (top) or CHIR99021 (bottom). d Quantification of stainings of proliferative (top) and apoptotic cells (bottom) in M11-derived xenografts treated with either vehicle (Captisol) or CHIR99021. e Representative immunostaining of Sox10 (red) and β-catenin (green) of skin of 5-month-old mice from the Tyr::NrasQ61KINK4a−/− melanoma mouse model treated with vehicle (Captisol) (left panel) or CHIR99021 (right panel) daily for 3 days in a row. Inserts show higher magnification of Sox10 and β-catenin immunostaining. f Quantification of subcellular localization of β-catenin of mice skin treated with either Captisol (vehicle) or CHIR99021 for 24 or 72 h (once every 24 h, 30 mg/kg). g Experimental scheme of treatment of 4–5-month-old-mice from the Tyr::NrasQ61KINK4a−/− melanoma mouse model with either vehicle (Captisol) or CHIR99021 (30 mg/kg) (n = 8/treatment group). h Kaplan–Meier survival analysis of vehicle (Captisol) treated mice compared to CHIR99021 treated mice (n = 8/treatment group) from the Tyr::NrasQ61KINK4a−/− melanoma mouse model. i Representative picture of two BrafV600E Pten−/− Tyr::CreERT2 mice (6–10 weeks old) treated with vehicle (Captisol) (left) or with 30 mg/kg CHIR99021 (right) sacrificed at the same time. j Kaplan–Meier survival analysis of vehicle (Captisol) treated mice compared to CHIR99021 treated mice (n = 3/treatment group) from the BrafV600E Pten−/− Tyr::CreERT2 melanoma mouse model. Data in b represent mean tumor volume ± s.e.m. Statistical significance was determined by log-rank (Mantel–Cox) test (h, j) or two-tailed Student’s t test (b, d, f). *P < 0.05, **P < 0.01, ***P < 0.001.
