BackgroundMany factors are involved with cellular differentiation and pluripotency, such as long non-coding and microRNAs (miRNA). miR-720 has been demonstrated to affect development, differentiation and pluripotency in dental pulp stem cells but has also been linked to many cancers (renal, prostate, skin, colorectal, breast, cervical and esophageal) through shared pathways including DNA methyltransferase family members (DNMT)3a and DNMT3b, which are highly upregulated in many oral cancers. However, little is known about the expression (or function, if expressed) of miR-720 in oral cancers. Based upon this lack of information, the primary objective of this project was to evaluate the expression of miR-720 among oral squamous cell carcinomas.MethodsRNA was extracted from commercially available oral cancer cell lines (SCC4, SCC9, SCC15, SCC25 and CAL27). This was subsequently screened for DNMT1, DNMT-3a, DNMT-3b, and miR-720 expression using high-specificity primers and polymerase chain reaction (RT-PCR). Proliferation assays were performed to determine the proliferation rate of each cell line.ResultsVariable expression of miR-720 was observed among the oral cancers. More specifically, expression was low or absent among SCC4 and SCC25 that correlated with relatively low expression of DNMT3a and DNMT3b mRNA expression. High expression was observed among CAL27, SCC15, and SCC9 cells that correlated with relatively higher levels of DNMT3a and DNMT3b. Pearson’s correlation found an association between proliferation rate of each cell line and expression of miR-720 assessed by RT-PCR; R = 0.8488.ConclusionsAlthough much is known about miR-720 – no studies to date have examined expression among oral cancers and tumor cell lines. This study may be the first to examine miR-720 expression in normal and cancerous oral tissues. These results demonstrate that miR-720 can be found in the most rapidly proliferating cell lines and may also correlate with expression of DNMT3a and DNMT3b expression in these same cell lines.