ML115

ML115 (CAS No.: 912798-42-6) is a synthetic small-molecule probe classified as a selective activator of signal transducer and activator of transcription 3 (STAT3), widely used in studies of intracellular signaling and transcriptional regulation. Acting as a cell-permeable STAT3 agonist with activity in the low nanomolar range, ML115 directly promotes STAT3-dependent transcriptional programs, including upregulation of the oncogene BCL3, and enhances STAT3 activation in response to cytokines such as IL-6. The compound exhibits high selectivity, showing negligible activity toward related signaling proteins including STAT1, STAT5, and NF-κB, thereby enabling precise interrogation of STAT3-driven pathways. In cellular systems, ML115 modulates processes associated with proliferation, differentiation, inflammatory responses, and oxidative stress, and has been shown to counteract certain anti-inflammatory or cytoprotective effects in stimulated cardiomyocyte and macrophage models. It demonstrates minimal cytotoxicity in representative fibroblast and tumor cell lines, supporting its utility as a research tool. ML115 is broadly applied in cancer biology, particularly in studies of breast and prostate cancer, as well as in stem cell research where sustained STAT3 activation is required to maintain pluripotency. Experimental concentrations typically fall within nanomolar to low micromolar ranges depending on assay design and biological context.