Circular RNAs in eukaryotic cells: origin, characteristics, mechanisms of molecular functioning in human malignant diseases

Circular RNAs (circRNAs) are an evolutionarily conserved novel class of non-coding endogenous (ncRNAs) found in the eukaryotic transcriptome, originally believed to be aberrant RNA splicing by-products with limited functionality.
 However, recent advances highthroughput genomic technology have allowed circRNAs characterized detail and revealed their important functions controlling various biological molecular processes, most essential being gene regulation. Due structural stability, high expression, availability microRNA (miRNA) binding sites tissue-specific become hot topic research 2 biology. Unlike linear RNAs, produced differentially by backsplicing exons or lariat introns from a pre-messenger (mRNA) forming covalently closed loop-like molecules missing 3' poly-(A) tail 5' cap structures, thus rendering them resistant exonuclease-mediated degradation.
 Previous studies multiple roles as sponges for miRNA RNA-binding proteins (RBP), well regulators transcription, translation, events. Recent field suggest that involved many human disorders, including cancer neurodegenerative disorders such Alzheimers Parkinsons disease, due expression different pathological conditions. The stable cells, owing circular structure. Participation programmed cellular destruction autophagy is discussed details. catabolic process which promotes decomposition recycling harmful redundant macromolecules initiates ageing cells. Processes how influence course discussed, specifying it joins at beginning upon development illnesses, can drug resistance (for example, antitumor efficiency Cisplatin).
 functional versatility exhibited enables serve potential diagnostic predictive biomarkers diseases. This review discusses properties, characterization, profiling, diverse actions usage therapeutic targets malignancies.