S3I-201

S3I-201 (also known as NSC 74859 or SVI-201) is a cell-permeable, amidosalicylic acid-based small molecule inhibitor of Signal Transducer and Activator of Transcription 3 (STAT3). Originally identified from the National Cancer Institute (NCI) chemical libraries through structure-based virtual screening, S3I-201 binds to the STAT3 Src Homology 2 (SH2) domain. This binding prevents STAT3 phosphorylation, dimerization, nuclear translocation, DNA binding, and transcriptional activation. S3I-201 is widely utilized as a chemical probe in preclinical research to investigate STAT3-dependent pathways in various cancers (including breast cancer, osteosarcoma, and head and neck squamous cell carcinoma) and inflammatory or autoimmune conditions. However, subsequent studies have revealed that S3I-201 can act as a non-selective covalent alkylating agent, modifying multiple intracellular proteins, which limits its utility as a highly selective STAT3 probe.

Other names

2-Hydroxy-4-(2-(tosyloxy)acetamido)benzoic acid2-hydroxy-4-[[2-(4-methylphenyl)sulfonyloxyacetyl]amino]benzoic acidSTAT3 Inhibitor VISTAT-3 Inhibitor VISTAT 3 Inhibitor VISVI-201SVI201SVI 201