The potential therapeutic efect of melatonin on human ovarian cancer by inhibition of invasion and migration of cancer stem cells
Maryam Akbarzadeh1,2, Ali Akbar Movassaghpour3, Hossein Ghanbari4, Maryam Kheirandish5, Nazila Fathi Marouf6, Reza Rahbarghazi7, Mohammad Nouri1,2 &Nasser Samadi2,6
There is an urgent need to identify targeting molecules to control invasion and metastasis in cancer patients. We frst isolated cancer stem cells (CSCs) from SKOV3 ovarian cancer cells and then investigated the role of melatonin in invasiveness and migration of CSCs compared to SKOV3 cells. The proportion of CSCs in SKOV3 cells was as low as 1.28% with overexpression of both CD133 and CD44. The ability of spheroid formation along with SOX2 overexpression revealed a high self-renewal potential in isolated cells. Melatonin (3.4mM) inhibited proliferation of CSCs by 23% which was confrmed by a marked decrease in protein expression of Ki67, as a proliferation marker. Applying luzindole, a melatonin receptor 1, 2 inhibitor, partially abolished anti-proliferative efect of melatonin. Melatonin also decreased Epithelial mesenchymal transition (EMT) related gene expressions including ZEB1, ZEB2, snail and vimentin with increase in E-cadherin as a negative EMT regulator. Incubation of CSCs with melatonin showed a marked decrease in matrix metalloproteinase 9 (MMP9) expression and activity. Melatonin also inhibited CSCs migration in a partially receptor dependent and PI3k and MAPK independent manner. Melatonin can be considered as an important adjuvant to control invasion and metastasis especially in patients with high melatonin receptor expression.