[Role of miRNA in malignoma of the head and neck].

Despite optimized therapeutic strategies, the long-term survival of head and neck squamous cell carcinomas (HNSCC) has improved in recent years only slightly. Most studies on the tumor cell genome focus on protein-coding genes (exons). Data on changes within the non-coding sequences (introns) are limited. miRNAs (microRNA, miR) are small non-coding single-stranded RNAs that control gene expression at the posttranscriptional level by interacting with the mRNA. miRNA functions include many biological processes and control up to 50 % of human genes. They can have oncogenic or tumor suppressive functions. Altered expression patterns of miRNAs are involved in carcinogenesis and tumor progression even in HNSCC, or those processes (increased resistance to radiation or chemotherapy) that could be responsible for the poor long-term prognosis by forming metastases and inoperable local recurrences. Therefore, we here present miRNA groups, which are involved in these processes and may serve as new potential therapeutic treatment targets. miRNAs may also serve as biomarkers for early diagnosis, evaluation and monitoring of treatment and tumor recurrence. Alterations in miRNA expression before and after chemotherapy are therefore of high interest. In the long run, this knowledge could lead to more effective therapies with improved therapeutic outcome of HNSCC. © Georg Thieme Verlag KG Stuttgart · New York.