The last decade was taken by storm when the existence of a class of small (˜22nt long) non - coding RNA species, known as microRNAs (miRNAs) came into light. MicroRNAs are one of the most abundant groups of regulatory genes in multicellular organisms and play fundamental roles in many cellular processes. Among these, miRNAs have been shown to prevent cell division and drive terminal differentiation, thus playing a causal role in the generation or maintenance of cancerous tumours. The unique expression profiles of different miRNAs in various types and stages of cancer suggest their performance as novel biomarkers. This discussion focuses on miRNAs implicated in cancer-associated events and strives to re-establish their sequential features which may classify them to be oncogenic.
Keywords: microRNA; oncogene; purines; sequence trademarks.