STAT3-IN-3 is a potent and selective inhibitor of signal transducer and activator of transcription 3 (STAT3) , with anti-proliferative activity. STAT3-IN-3 induces apoptosis in breast cancer cells. STAT3-IN-3 acts as a promising mitochondria-targeting STAT3 inhibitor for cancer research In Vitro STAT3-IN-3 has no influence on the phosphorylation levels of STAT1, JAK2, Src and Erk1/2. STAT3-IN-3 inhibits the growth of MDA-MB-231, HCT-116, HepG2, and MCF-7 cells with IC 50 s of 1.43 μM, 1.89 μM, 2.88 μM, and 3.33 μM, respectively. STAT3-IN-3 down-regulates the expression of STAT3 target genes Bcl-2 and Cyclin D1. STAT3-IN-3 inhibits STAT3 tyrosine phosphorylation and serine phosphorylation. STAT3-IN-3 inhibits STAT3 DNA-binding activity. STAT3-IN-3 (1-4 μM; 24 hours) increases ROS production and remarkably reduces the mitochondrial membrane potential to induce mitochondrial apoptotic pathway. STAT3-IN-3 (1-4 μM; 24 hours) can induce the cleavage of caspase-9, caspase-3 and PARP. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Cell Viability AssayCell Line: MDA-MB-231 cells, HCT-116 cells, HepG2 cells, MCF-7cells Concentration: MTT assay Incubation Time: 48 hours Result: Exhibited anti-proliferative activity. Apoptosis AnalysisCell Line: MDA-MB-231 cells Concentration: 0 μM, 1 μM, 2 μM, 4 μM Incubation Time: 24 hours Result: Induced the apoptosis of MDA-MB-231 cells dose-dependently and the apoptosis rates. Western Blot AnalysisCell Line: MDA-MB-231 cells Concentration: 0 μM, 1 μM, 2 μM, 4 μM Incubation Time: 24 hours Result: Induced the cleavage of caspase-9, caspase-3 and PARP. In Vivo STAT3-IN-3 (10mg/kg-20 mg/kg; i.p.; daily; for 14 days) possesses potent antitumor activity against implanted 4T1 breast tumors growth . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Adult female BALB/c mice (6 weeks of age) Dosage: 10 mg/kg, 20 mg/kg Administration: Intraperitoneal injection, daily, for 14 days Result: Significantly inhibited tumor volume. Form:Solid IC50& Target:STAT3