Multifunctional Roles of miR-34a in Cancer: A Review with the Emphasis on Head and Neck Squamous Cell Carcinoma and Thyroid Cancer with Clinical Implications

MiR-34a belongs to the class of small non-coding regulatory RNAs and functions as a tumor suppressor. Under physiological conditions, miR-34a has an inhibitory effect on all processes related to cell proliferation by targeting many proto-oncogenes and silencing them on the post-transcriptional level. However, deregulation of miR-34a was shown to play important roles in tumorigenesis and processes associated with cancer progression, such as...