Human melatonin receptors consist of melatonin receptor 1A (MT1) and melatonin receptor 1B (MT2), and possess various biological activations, which include the control of circadian rhythm and immune regulation. Recently, it have been found that melatonin receptors inhibit cell proliferation and have oncostatic properties, which is being researched in the treatment strategies of breast cancer, prostate cancer, and Non-Small Cell Lung Cancer. Also, interest in the effect of melatonin receptor’s correlation to head and neck carcinogenesis and application possibilities on head and neck cancer has been found. However, in head and neck cancer, how melatonin receptor relates and functions with epithelial-mesenchymal transition (EMT), which plays a major role in human carcinogenesis, is yet unknown. In this research, in HSC5 cell and YD15 cell, the head and neck cancer cell lines, a selective melatonin receptor antagonist, Luzindole, was utilized to examine the effect of melatonin receptors on EMT. After treating Luzindole on HSC5 cells and YD15 cells, the authors evaluated cell viability rate with CCK 8 assay, and performing colony forming assay, invasion assay and western blot analysis, to confirm melatonin receptor’s effect on EMT. When Luzindole was treated on HSC5 cells and YD15 cells in low concentration of 100nM, no significant difference in cell viability was found, whereas Luzindole-treated cells had a significantly increase in the invasion assay. As a result of colony forming assay, in YD15 cells, the number of colony formation decreased slightly, whereas in HSC3 cells, the number of colony formation increased. According to the western blotting, no difference in E-cadherin, Slug, and vimentin protein expression was shown. This result of research indicates the possibility of melatonin receptor being related to EMT and new chemotherapeutic target in the carcinogenesis of head and neck cancer.

Melatonin is a neurotransmitter that modulates various physiological phenomena including regulation and maintenance of the circadian rhythm. Nicotinic acetylcholine receptors (nAChRs) play an important role in oral functions including orofacial muscle contraction, salivary secretion, and tooth development. However, knowledge regarding physiological crosstalk between melatonin and nAChRs is limited. In the present study, the melatoninmediated modulation of nAChR functions using bovine adrenal chromaffin cells, a representative model for the study of nAChRs, was investigated. Melatonin inhibited the nicotinic agonist dimethylphenylpiperazinium (DMPP) iodide-induced cytosolic free Ca2+ concentration ([Ca2+]i) increase and norepinephrine secretion in a concentrationdependent manner. The inhibitory effect of melatonin on the DMPP-induced [Ca2+]i increase was observed when the melatonin treatment was performed simultaneously with DMPP. The results indicate that melatonin inhibits nAChR functions in both peripheral and central nervous systems.

골든 햄스터의 생식활동은 광주기에 의해 조절된다. 그들의 생식능력은 여름에 왕성하고 겨울에는 퇴화한다. 송과선에서 분비되는 멜라토닌은 계절적 번식동물에서 생식활동을 중재한다. 멜라토닌 수용체가 최근에 사람을 포함하는 몇몇 동물에서 확인되었지만 골든 햄스터의 생식능력과 관련하여 알려진 바가 많지 않다. 역전사 PCR 방법을 사용하여 멜라토닌 수용체의 일부 유전자를 동정하였다(309 염기). 멜라토닌 수용체의 핵산 서열과 추론된 아미노산 서열을 보고된 다른