Verification of agomelatine in comparison with melatonin as a therapeutic agent to treat breast cancer

The breast cancer (BC) has a high rate of morbidity and mortality; thus, the discovery of new therapeutic targets is of great interest for researchers. Previous studies have documented that melatonin, the main hormone synthesized by the pineal gland, plays important roles in the control of breast tumorigenesis. Similar to melatonin, agomelatine, a melatonin analogue can also perform its functions by binding to G protein coupled melatonin membrane receptors MT1 and MT2. In a series of studies carried out in two breast cancer cell lines (MCF-7 and MDA-MB-231 strains), the dose-responsive curves have been identified regarding cell viability, clonogenic survival, and cell migration.  The results indicate that agomelatine has the potential to reduce the proliferative capacity in both cell lines, while melatonin significantly reduced the proliferative rate of triple-negative BC cells. Notably, agomelatine and melatonin showed the same inhibitory effect on BC cell migration. Collectively, agomelatine treatment caused a greater reduction in BC cell growth than that of melatonin which only suppressed the proliferative capacity of triple-negative BC. Also, melatonin and agomelatine have the same inhibitory response to migratory capacity of triple-negative BC cells. Based on the results from current study on BC cells, agomelatine could be considered as a promising adjuvant therapeutic agent compared to melatonin for BC treatment.