STAT3-IN-11 (7a) is a selective STAT3 inhibitor that inhibits the phosphorylation of STAT3 at site pTyr705 . STAT3-IN-11 inhibits the phosphorylation of downstream genes ( Survivin and Mcl-1 ) without affecting its upstream tyrosine kinases (Src and JAK2) levels and p-STAT1 expression. STAT3-IN-11 can induce cancer cell apoptosis , which is potential for the discovery of effective STAT3 inhibitors and antitumor agents against cancers In Vitro STAT3-IN-11 (20 μM, 48 h) has 97.86% inhibitory effect on MDA-MB-231 cells. STAT3-IN-11 (0-30 μM, 48 h) inhibits several cancer cells with IC 50 values of 6.01 μM (MDA-MB-231), 7.02μM (HepG2, A549), and normal human cells with IC 50 values of 26.54 μM (MDA-MB-10A), 26.69 μM (PBMCs), 12.52 μM (HFL-1). STAT3-IN-11 (2.5-10 μM, 6 h) inhibits the phosphorylation of STAT3 (stimulated by IL-6 in MDA-MB-231) at site pTyr705 in a dose-dependent manner. STAT3-IN-11 (2.5-10 μM, 6 h) inhibits the expression of the downstream gene (Survivin and Mcl-1) of STAT3 in a concentration-dependent manner. STAT3-IN-11 (2.5-10 μM, 6 h) has no effects on the typical upstream kinases of STAT3 such as p-JAK2 and p-Src and the phosphorylation of STAT1 (a STAT isoform). STAT3-IN-11 (2.5-10 μM, 48 h) can induce cell apoptosis in a dose-manner. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Cell Cytotoxicity AssayCell Line: MDA-MB-231 cells Concentration: 20 μM Incubation Time: 48 hours Result: The antiproliferative activity reached 97.86%. Cell Cytotoxicity AssayCell Line: MDA-MB231, A549, MDA-MB-10A, PBMCs and HFL-1 cells Concentration: 20 μM Incubation Time: 48 hours Result: Inhibited with IC 50 values of 6.01, 7.20, 7.02, 26.54, 25.69 and 12.52 μM for MDA-MB231, A549, MDA-MB-10A, PBMCs and HFL-1 cells, respectively. Western Blot AnalysisCell Line: MDA-MB-231 cells Concentration: 2.5,5 and 10 μM Incubation Time: 6 hours Result: Decrease the level of p-STAT3 at site pTyr705 in a concentration dependent manner. Western Blot AnalysisCell Line: MDA-MB-231 cells Concentration: 2.5,5 and 10 μM Incubation Time: 6 hours Result: Down-regulated the level of STAT3 downstream genes. Apoptosis AnalysisCell Line: MDA-MB-231 cells Concentration: 5, 10 and 15 μM Incubation Time: 48 hours Result: The percentage of apoptotic cells was 24.4% at a concentration of 15 μM. Form:Solid IC50& Target:IC 50 : 1.93 μM (SIP), ≥ 30 μM (SphK1), ≈ 30 μM (SphK2)