Abstract
INTRODUCTION: MicroRNAs (miRs) are crucial micro-genetic markers that significantly manipulate gene expression in neoplastic/malignant and non-neoplastic diseases, as viral infections. Different expression patterns of miRs seem to partially influence the response rates to specific chemo-targeted therapeutic regimens and prognosis in cancer patients. Concerning their nature, miRs are short non-coding RNAs including 20-25 nucleotides hosted in intra- or intergenic regions. Their most important function is the positive regulation of post-transcriptional gene silencing levels. Based on this activity, they enhance normal cell functions, including proliferation, apoptosis and tissue differentiation. Their deregulation in cancerous cells due to epigenetic and transcriptional imbalances is correlated with an excessive production of target mRNA. OBJECTIVE: In the current paper, our aim was to generally describe the role of MiRs in cancer genome and we mainly focused on specific host target-cell miRs that are affected by SARS-CoV-2 in the COVID-19 pandemic. MATERIAL AND METHOD: A systematic review of the literature was carried out based on the international database PubMed focused on miR nature, origin, structure and function in cancer genome and more recently on the influence of SARS-CoV-2 on affected cells. The following keywords were used: microRNA, SARS-CoV-2, COVID-19, infection, cancer, virus. A pool of 52 important articles were selected for the present review at the basis of exploring the SARS-CoV-2 efficacy in miRs. RESULTS: A broad set of miRs, including miR-122, miR-16-2-3p, miR-3605-3p, miR-15b-5p, miR-486-3p, miR-486-5p, miR-447b, miR-3672, miR-325, miR-447b and miR-222, has been identified to be deregulated by SARS-CoV-2 infection. CONCLUSIONS: miRs represent significant micro-epigenetic markers frequently deregulated in SARS-CoV-2 mediated infection (COVID-19). Interactions between miRs and SARS-CoV-2 RNA genome are under investigation. miR overexpression/expression loss in SARS-CoV-2 affected epithelia is correlated with specific genetic and by epigenetic signatures in the corresponding patients.