biostudies-literatureZubiete-Franco ISimons FoundationIrving A Hansen Memorial FoundationNIDDK NIH HHSNCI NIH HHSNIHDon Monti Memorial Research Foundation150763https://www.ebi.ac.uk/biostudies/studies/S-EPMC11490372biostudies-literatureUnknown734While vaccines were being developed, the SARS-CoV-2 pandemic triggered a race to find known drugs that could be quickly repurposed to treat patients. One such candidate was famotidine, which retrospective cohort studies had shown increased survival in hospitalized patients. Computational studies had suggested that famotidine may target early viral proteases; however, ultimately, famotidine was shown not to function as a viral inhibitor. In contrast, we have observed a change in the cellular levels of phospho-tyrosine in A549 lung epithelial cells following treatment with famotidine. This quick change in phosphorylation was due mainly to a dose-dependent increase in cellular production of H₂O₂. Notably, these changes in phospho-tyrosine levels were able to affect cell Biochemical and biophysical research communicationsFamotidine increases cellular phospho-tyrosine levels.PMC11490372R01 CA053840R37 CA053840P30 CA045508R01 DK124907Tonks NKZubiete-Franco IfalseFamotidine increases cellular phospho-tyrosine levels.While vaccines were being developed, the SARS-CoV-2 pandemic triggered a race to find known drugs that could be quickly repurposed to treat patients. One such candidate was famotidine, which retrospective cohort studies had shown increased survival in hospitalized patients. Computational studies had suggested that famotidine may target early viral proteases; however, ultimately, famotidine was shown not to function as a viral inhibitor. In contrast, we have observed a change in the cellular levels of phospho-tyrosine in A549 lung epithelial cells following treatment with famotidine. This quick change in phosphorylation was due mainly to a dose-dependent increase in cellular production of H₂O₂. Notably, these changes in phospho-tyrosine levels were able to affect cell 2024-01-01T00:00:00Z2024 Nov2026-06-05T16:35:17.107Z2026-05-18T03:13:09.923ZS-EPMC114903723936202810.1016/j.bbrc.2024.150763