Are Circulating microRNAs Involved in Tumor Surveillance?
By studying literature data and having performed an in silico analysis, the circulating microRNA expression profiles of healthy individuals appear to show an abundance of microRNAs with predominant tumor suppressor activity. We hypothesize that circulating tumor suppressor microRNAs might constitute a sort of continuous tumor surveillance, whereby circulating microRNAs delivering gene expression modulating epigenetic information might halt cell transformation and tumorigenesis. This mechanism might complement the well-known cancer immune surveillance. A further hypothesis is also discussed, supposing that the tissue specific action of microRNAs might represent a putative defense mechanism against the potential tumor-promoting actions of secreted miRNA.
KeywordsTumor Circulating microRNA Healthy Surveillance
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