{"doi":"10.1101/2025.08.08.669362","title":"ZYS-1 is not an ADAR1 inhibitor","abstract":"Abstract Adenosine deaminase acting on RNA 1 (ADAR1) edits double-stranded RNA (dsRNA) substrates by the deamination of adenosine to inosine in a process known as A-to-I editing. Modulation of ADAR1 expression and editing activity has previously been described to play a role in cancer development and progression, with upregulation of ADAR1 being observed in a range of cancers. Further, depletion of ADAR1 leads to increased sensing of endogenous dsRNAs by dsRNA sensors in cell lines that require ADAR1 for survival, which are termed ADAR1-dependent. The activation of these sensors induces downstream production of type I interferons as well as translational inhibition and apoptosis. Therefore, ADAR1 is a promising oncologic therapeutic target. Recently, the small molecule ZYS-1 has been developed and presented as a direct inhibitor of ADAR1. We performed a series of in vitro and cellular experiments to validate the efficacy and specificity of ZYS-1 as an ADAR1 inhibitor. Evaluating the effect of ZYS-1 on cell viability revealed it to be equally cytotoxic to both ADAR1-dependent and ADAR1-independent cell lines, as well as wildtype and ADAR1 knockout cells. Moreover, ZYS-1 treatment had little effect on activation of PKR or induction of IFN stimulated genes. Importantly, treatment with ZYS-1 did not reduce cellular A-to-I editing for several known ADAR1 editing sites, and did not inhibit in vitro A-to-I editing by recombinant ADAR1. Together, these data indicate that ZYS-1 is not a selective inhibitor of ADAR1.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2025,"id":572168,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9546,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1458500,"name":"Estelle N. Gardner","orcid":null,"position":1,"is_corresponding":false},{"id":1458499,"name":"Renee N. Chua","orcid":null,"position":2,"is_corresponding":false},{"id":278036,"name":"Kyle A. Cottrell","orcid":"0000-0003-1779-4292","position":3,"is_corresponding":false},{"id":1478819,"name":"Cassandra N. Smoak","orcid":null,"position":0,"is_corresponding":true}],"reference_count":43,"raw_metadata":null,"created_at":"2026-07-19T02:57:23.653298Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}