Fig. 1

A pharmacological screen identifies Tegaserod (TM) as having anti-melanoma activity. a B16F10 murine melanoma cells were treated with 770 pharmacologically active compounds at a concentration range of 10 μM-78 nM. Several classes of compounds had anti-cancer activity with IC50 values in the low micromolar range as assessed by MTT assay following 72 h of exposure. b Tageserod (TM) a serotonin agonist was further validated and found to have anti-cancer effects in the B16F10 cell line and a panel of human malignant melanoma cell lines, A375, RPMI-7951 (RPMI), SH4, SK-MEL-24, MeWo and MEL-JUSO (n = 3–6). c Treatment with low micromolar doses of TM induced apoptosis in a time and dose-dependent manner as assessed by Annexin V/7AAD staining (n = 4–6). Percent apoptosis was ascertained by summing up the Annexin V⁺/7AAD⁻ and Annexin V⁺/7AAD⁺ populations. *P < 0.05 as determined by a 2-way ANOVA with a Dunnett’s post-hoc test. d, left panel Immunofluorescent TUNEL staining of RPMI cells 48 h post TM (5 μM) treatment is shown (A representative image of n = 3–5 is shown). *P < 0.05 as determined by a 1-way ANOVA with a Dunnett’s post-hoc test. Scale bar indicates 100 μm. d, right panel Quantification of the TUNEL apoptosis staining is shown (n = 3–5). Error bars in the all experiments indicate SEM