Search

Objectives Head and neck/oral cancer, predominantly head and neck squamous cell carcinoma (HNSCC), is the sixth most common cancer in the world. While substantial advances have been made to define the genomic alterations associated with head and neck/oral cancer, most studies are focused on protein coding genes. The aim of this article is to review the current literature on identified genomic aberrations of non-coding genes (e.g., microRNA) in head and neck/oral cancer (HNOC), and their contribution to the initiation and progression of HNOC. Material and Methods A comprehensive review of the available literature relevant to microRNA deregulation in HNSCC/HNOC, was undertaken using PubMed, Medline, Scholar Google and Scopus. Keywords for the search were: microRNA and oral cancer, microRNA and squamous cell carcinoma, microRNA deregulation and oral cancer, microRNA and carcinogenesis in the head and neck/oral cavity. Only full length articles in the English language were included. Results We recently identified a panel of microRNA deregulations that were consistently observed in HNSCC [Chen et al., Oral Oncol. 2012;48(8):686-91], including 7 consistently up-regulated microRNAs (miR-21, miR-7, miR-155, miR-130b, miR-223, miR-34b), and 4 consistently down-regulated microRNAs (miR-100, miR-99a, miR-125b, miR-375). In this review, we will first provide an overview on microRNA and HNSCC. We will then provide a comprehensive review on the roles of microRNA deregulations in HNSCC. The functional significance of the identified HNSCC-associated microRNAs and a number of other relevant microRNAs (e.g., miR-138, miR-98, miR-137, miR-193a and miR-218) will be discussed in detail. Conclusions Based on current literature, microRNA deregulation plays a major role in head and neck/oral cancer.

Objectives Cancer is the product of alterations in oncogenes, tumour suppressor genes and most recently microRNA genes not as a single event or single change but rather as a multistep process. The role of microRNA genes in carcinogenesis is recently explored and appears to be an early event in the pathogenesis of this as well as other disease processes and occurs via gene regulation by their own products, the microRNAs. The purpose of this article was to review the literature concerning MicroRNA proposed target genes in oral cancer. Material and Methods A review of the available literature from 2000 to 2011 regarding the potential roles assumed by microRNAs in oral cancer was undertaken using PubMed, Medline, Scholar Google and Scopus. Keywords for the search were: microRNA and oral cancer and target genes, microRNA deregulation and oral cancer, microRNA and carcinogenesis in the head and neck/oral cavity. English language full length articles were reviewed. Results Several microRNAs deregulated in oral cancer have been functionally validated and their exact target genes have been identified. Furthermore the carcinogenesis pathways impacted by these alterations has been proposed for some of these microRNAs. Conclusions The expanding knowledge of specific roles of certain microRNAs is further contributing to our understanding of the complexity of tumour progression and behaviour. Consideration of this information and incorporation into treatment modalities through targeted therapy could potentially enhance our abilities to improve outcome especially when other established therapies have failed.