4 Discussion

In this study, the hypothesis that host cell miRNAs may have influenced the evolution of SARS-CoV-2 was tested. Two sets of miRNAs expressed in the main sites of virus reproduction, the lungs and the intestine, were considered. It was found that those sets significantly differed in the representation of individual miRNAs. On one hand, hsa-miR-143-3p, hsa-miR-21-5p, hsa-miR-22-3p and hsa-miR-30a-5p were specific for the lungs, with large predominance of miR-1433p expression (41.5%). On the other hand, the intestine was characterized by a more uniform profile with the presence of tissue-specific let-7b-5p, miR-92a-3p and miR-200c-3p. During pandemics, SARS-CoV-2 genomes lost many miRNA binding sites specific for the lung and intestinal tissue expressed miRNAs. Importantly, MonteCarlo simulations showed that observed changes were significant only for the set