Effects of Melatonin on the Expression of Invasion‐Related Markers (MMP2 and MMP9) in Breast Cancer Cells

Breast cancer is one of the most common types of cancer in women, and metastasis is a leading cause of mortality in patients with this disease. This study investigated the effects of melatonin, a natural hormone, on the migration of cancer cells in two cell lines, MCF-7 and MDA-MB-231. MCF-7 and MDA-MB-231 cells were cultured in their respective media. The effective dose of melatonin in each cell line was determined using the MTT assay. The effects of IC50 melatonin on cell migration were assessed using the wound-healing assay. The expression of the invasion-related genes (MMP2 and MMP9), as well as the melatonin receptors MT1 and MT2, was analyzed using Real-Time RT-PCR. The wound-healing assay results indicated that 48 h of melatonin treatment at doses of 2.5 and 3.5 M significantly reduced migration in MCF-7 and MDA-MB-231 cells. In addition, melatonin treatment decreased the invasion-related markers of both cell lines. Melatonin also increased the expression of MT1 and MT2 receptors in both cell lines, and the expression of MMP2 and MMP9 was significantly reduced by melatonin (p < 0.05). Our results indicate that melatonin, a naturally occurring compound, possesses the potential to inhibit the movement and spread of breast cancer cells by elevating the levels of MT1 and MT2 receptors, resulting in a reduction of matrix metalloproteinases 2 and 9 expression.