Alterations in Oral Cancer Gene Expression in Response to Melatonin

Abstract

Aims: Melatonin (MLT) exerts oncostatic effects on numerous tumour types presumably by inhibiting cell proliferation and promoting apoptosis. The primary aim of this study was to investigate melatonin-induced changes in gene expression patterns in two different oral squamous carcinoma cell lines (OSCC). Methodology: This was a prospective non-randomized experimental study design that was conducted at Department of Biomedical Sciences at the University of Nevada, Las Vegas -School of Dental Medicine between May 2016 and March 2017. The SCC25 and CAL27 cell lines were cultured with and without MLT (10 ug/mL) for 72 hours, and total cellular RNA was isolated and converted to cDNA. The expression of 92 genes associated with the molecular mechanisms of cancer and four endogenous control genes were examined by qRT-PCR. The fold change with respect to control levels were calculated using the comparative method or delta-delta ddCt algorithm.

Differential MicroRNA Expression of miR-21 and miR-155 within Oral Cancer Extracellular Vesicles in Response to Melatonin

“…Melatonin ( N -acetyl-5-methoxy-tryptamine) used in this study was purchased from Thermo Fisher Scientific (Fair Lawn, NJ, USA). Each experiment was performed with and without the addition of melatonin to the cell culture medium at 10 μg/mL for 72 h, as previously described [28]. This concentration was selected to approximate serum concentrations of melatonin found in serum and saliva following administration as an over-the-counter supplement [28,29,30].…”

“…Each experiment was performed with and without the addition of melatonin to the cell culture medium at 10 μg/mL for 72 h, as previously described [28]. This concentration was selected to approximate serum concentrations of melatonin found in serum and saliva following administration as an over-the-counter supplement [28,29,30]. Non-treated cells were used as the negative control and each experiment was repeated in triplicate (n = 3) for each cell line and both conditions (negative control, experimental).…”

“…Although previous studies from this group have evaluated changes to oral cancer gene expression under melatonin administration, as well as differential expression of oral cancer exosomes, extracellular vesicles, and microRNAs, no studies to date have analyzed the effects of melatonin on microRNA expression in oral cancers [27,28]. Based upon the paucity of evidence in this area, the primary goal of this project was to evaluate the effects of melatonin administration on the expression of specific microRNAs, such as miR-21, miR-133a and miR-155 among oral cancers.…”

Analysis and Evaluation of the Effects of Melatonin on Oral Keratinocytes: A Pilot Study

“…Melatonin (C13H16N2O2) was obtained from Tocris Biosciences (35-505-0) through Fisher Scientific (Fair Lawn, NJ) CAS 73.31-4 with a verified molecular weight (MW) of 232.283, as previously described [39]. Melatonin was suspended in DMEM cell culture media (described above) using supplement-equivalent physiologic concentration at the low-, mid-and high-range corresponding to 1.0, 5.0 and 10.0 ug/uL, which approximates the range of physiologic and bioavailable concentrations of melatonin found in saliva and serum following over-the-counter supplementation [40][41][42]. Negative controls were created using media (DMEM) without the addition of melatonin.…”