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Figure 4 | Breast Cancer Research

Figure 4

From: Inhibition of breast cancer cell invasion by melatonin is mediated through regulation of the p38 mitogen-activated protein kinase signaling pathway

Figure 4

Melatonin suppresses the expression and activity of MMP-2 and MMP-9 in human breast cancer cells. Conditioned medium was collected and concentrated as described in Materials and methods. (a) Melatonin's effect on the protein expression of MMP-2 and MMP-9. MCF-7/6 cells were treated with melatonin (Mlt, 10-9 M) or diluent (Control, 0.00001% ethanol) for 48 hours. Expression of MMP-2 and MMP-9 in the conditioned medium was analyzed by Western blot analysis using anti-MMP-2 and anti-MMP-9 antibody. (b) The effect of melatonin on the activity of MMP-2 and MMP-9. MCF-7/6 cells were treated with melatonin (Mlt, 10-9 M) or diluent (Control, 0.00001% ethanol) for 48 hours. The gelatinase activity of MMP-9 and MMP-2 in the conditioned medium was determined by gelatin zymography. The band intensities of MMP-9 and MMP-2, respectively, are presented in the graph as percentages of control (set as 100%). *P < 0.05 versus diluent-treated control (n = 4). (c) Effect of melatonin on stromal-derived factor-1 (SDF-1)-induced activity of MMP-9 in MCF-7/CXCR4 cells. MCF-7/CXCR4 cells were treated with diluent (control, 0.00001% ethanol), SDF-1 (100 ng/mL), or melatonin (10-9 M) and SDF-1 (100 ng/mL) simultaneously (Mlt + SDF-1) for 24 hours. The gelatinase activity of MMP-9 in the conditioned medium was determined by gelatin zymography. The band intensity of MMP-9 is presented in the graph as percentage of control (set as 100%). *P < 0.05 versus diluent-treated control; **P < 0.05 versus SDF-1-treated group (n = 3). Figures in (a-c) are representative Western blots or gelatin zymograms of at least three independent studies, respectively. MMP, matrix metalloproteinase.

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