Fig. 6

Combining 6-thio-dG and Gamitrinib inhibits the growth of 3D melanoma spheroids and NRAS-mutant xenograft tumors. a Collagen-embedded melanoma spheroids were treated with DMSO, 6-thio-dG (5 µM), or Gam (5 µM) as in Fig. 4. On day 7, spheroids were stained with Calcein AM (live cells; green) and EtBr (dead cells; red), and imaged using an inverted microscope (×4; scale bar = 250 µm). Representative merged images from three independent experiments are shown. b–e NRAS-mutant M93-047 tumor-bearing mice were treated with vehicle control, 6-thio-dG (2.5 mg/kg; ip qd), Gam (12.5 mg/kg; ip qod), or the combination of the two drugs for the indicated days (n = 7 mice/group). b Average tumor volume over time ± SEM is represented. c Average tumor weight ± SEM after 14 days of treatment. p-values were calculated using unpaired Student’s t-test. *p < 0.05, **p < 0.01, ***p < 0.005, when comparing vehicle control vs. combination treatment groups. d Treatment was discontinued after 14 days, and mice were followed until tumor volume reached a preset volume (1500 mm³). Kaplan–Meier survival curves of mice treated for 14 days. p-values were calculated by Mantel–Cox log-rank test; *p < 0.05, **p < 0.01, ***p < 0.005. e Animal weight (grams) before treatment (start of TX) and at the end of the study (end of TX) was assessed and recorded for every mouse enrolled in the study. Mean and SEM are depicted (n = 7 mice per treatment group). Statistical significance was assessed by unpaired Student’s t-test