MicroRNAs in an oral cancer context - from basic biology to clinical utility

Oral cancer is one of the most commonly diagnosed malignancies worldwide. Its dismal five-year survival rate of ~50% has barely changed for decades. A better understanding of the molecular basis of tumorigenesis - with particular emphasis on disease initiation and progression - is needed to improve clinical outcomes, since this will facilitate the development of drugs and management strategies based on the specific genetic changes underpinning disease behaviors. MicroRNAs (miRNAs), a class of short non-coding RNAs that down-regulate gene expression, have been demonstrated to play essential roles in human cancers. miRNA deregulation has been observed in many tumor types and is implicated in oncogenic cell processes, including proliferation, survival, apoptosis, metastasis, and chemoresistance. In addition, miRNA alterations have been associated with specific clinical phenotypes such as disease progression or recurrence, development of metastases, and post-operative survival. Recent studies have explored the utility of miRNAs as diagnostic and prognostic tools and as potential therapeutic targets. Herein, we discuss miRNA biology and provide a summary of the key findings on the role of miRNAs in oral malignancies.