Figure 6
From: Altered serotonin physiology in human breast cancers favors paradoxical growth and cell survival
Growth inhibition by 5-HT in non-transformed human mammary epithelial cells is via 5-HT7 recepto, r and breast cancer cells are refractory to growth inhibition by 5-HT. (Ai-iv) Proliferation assay (MTT) for detecting growth of primary human mammary epithelial cells (pHMECs) (Ai) and MCF10A (Aii-iv) after a period of 36 h following indicated treatments. Graphs are plotted as percent change from control (Ctrl - untreated) group. Error bars represent ± SEM. ***P < 0.001 (one-way ANOVA). (Ai and Aii), depict indicated cells treated with 5-HT (7.5 × 10-4 M) in presence or absence of broad-spectrum 5-HT receptor antagonist methysergide (MS) (60 μM). (Aiii) depicts MCF10A cells treated with 5-HT (7.5 × 10-4 M) in presence or absence of specific 5-HT7 receptor antagonist SB 269970 (SB) (80 μM). (Aiv) depicts MCF10A cells treated with 5-HT (7.5 × 10-4 M) in presence or absence of specific inhibitors of signaling proteins p38 MAPK (SB203580 [p38I]) (20 μM) and PKA (H89 [PKAI]) (10 μM). (Bi-ii) depict a proliferation assay (MTT-viable count) for detecting cell growth after 36 h of treatment with indicated 5-HT concentrations. Graphs are plotted as percent change from respective controls (untreated group). Error bars represent ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001 (Two-way ANOVA). (Bi) depicts comparison of pHMECs (grey bars) and T47D (black bars) cells response to indicated 5-HT concentrations. (Bii) depicts comparison of MCF10A (grey bars) and MDA-MB-231 (black bars) cells response to indicated 5-HT concentrations. (Biii) depicts measurements of intracellular cAMP accumulation in MCF10A (grey squares and line) and MDA-MB-231 (black triangle and line) cells in response to 5-HT stimulation as indicated. Error bars in Biii represent ± SEM. ** P < 0.01, *** P < 0.001 (Two way ANOVA).