Circular RNAs in virus-induced cancers: From mechanism to clinical implications.

Viruses, during their lifecycle, are continuously dependent on host machinery for their survival. Sometimes this dependency leads to uncontrolled cell proliferation in the host, accounting for 12% of virus-associated cancers. Since early times, viruses have been known to produce proteins and dysregulate host proteins, but what is new to the field is the addition of a circular regulatory RNA called "circRNA". circular RNAs, due to their structure-associated stability and specificity for various cancers, are key RNA molecules for researchers seeking to understand the complex outcomes of virus-associated cancers. circRNAs can serve as both therapeutic targets and diagnostic markers due to their unique back-spliced junctions formed by back-splicing of pre-mRNA and their presence in bodily fluids. Additionally, they can be potential candidate for vaccine development. This review provides a detailed overview of how viral and host circRNAs in seven oncogenic virus-associated cancers collectively reconstruct distinct host proteins, microRNAs, and mRNAs. It discusses the discovery, biogenesis, and function of circRNAs; their roles as therapeutic targets and diagnostic markers; and the emergence of new computational and Artificial Intelligence (AI)-driven circRNA modeling.