PTPN23 silencing sensitizes BRAF ^V600E melanoma cells to BRAFi . (A) Relative cell number of dox-induced PTPN23-depleted A375 cells treated with or without 2 μM Vemu or 2 μM Dabr. Cell viability was measured by the CCK8 assay after 72 h (n = 3). One-way ANOVA, Bonferroni’s test. (B) Colony formation assay of the cells described in A treated with or without 2 μM Vemu or 2 μM Dabr. Colonies were stained with crystal violet after 14 days. (C) Flow cytometric analysis of living and apoptotic cells of dox-induced PTPN23-depleted A375 cells treated with or without Vemu or Dabr (n = 3). One-way ANOVA, Bonferroni’s test. (D and E) Tumor volume (D) and weight (E) of A375 xenografts in nude mice with indicated treatments. Mice were given a dox-supplemented diet (400 ppm) or daily gavage administration of Vemu (20 mg/kg) starting 10 days after implantation (n = 6 mice per group). Data represent the mean ± SEM. Two-way ANOVA, Bonferroni’s test (D) or one-way ANOVA, Bonferroni’s test (E). (F) Photograph of xenograft tumors from nude mice inoculated with A375 cells from the indicated groups (n = 6 mice per group). (G) Ki67 staining showing proliferation of A375 xenograft tumors with PTPN23 depletion or Vemu treatment. Scale bar, 50 μm. (H) Relative cell number of Vemu-Res A375 and SK-MEL-28 cells with or without PTPN23 depletion. Cell viability was measured by the CCK8 assay after 72 h (n = 3). Unpaired t test. (I) Colony formation assay of Vemu-Res A375 and SK-MEL-28 cells with or without PTPN23 depletion. Colonies were stained with crystal violet after 14 days. ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05; P > 0.05; not significant (ns).