STAT3-IN-9, a potent inhibitor of STAT3 activation at Tyr705, exhibits no impact on the phosphorylation of STAT1 at Tyr 701. Additionally, this compound efficiently induces apoptosis and cell cycle arrest specifically at the G2/M phase [1].

STAT3-IN-9 (compound C6) (48 h) shows potent in vitro anti-tumor activity with IC 50 s of 0.16, 5.80, 1.63, 5.73, >25, >25 μM for MDA-MB-468, MDA-MB-231, HepG2, A549, U251, HCT116 cells, respectively [1]. STAT3-IN-9 (0, 0.2, 1.0, 5.0 μM; 24 h) inhibits the activation of STAT3 (Tyr705) without influencing the phosphorylation of STAT1 (Tyr701) [1]. STAT3-IN-9 (0, 0.2, 1 μM; 24 h) induces apoptosis through the mitochondrial Caspase dependent apoptotic pathway [1]. STAT3-IN-9 (0, 0.2, 1 μM; 24 h) induces cell cycle arrest at the G2/M phase in a dose-dependent manner [1]. Cell Proliferation Assay [1] Cell Line: MDA-MB-468, MDA-MB-231, HepG2, A549, U251, HCT116 cells Concentration: Incubation Time: 48 h Result: Showed potent in vitro anti-tumor activity with IC 50 s of 0.16, 5.80, 1.63, 5.73, >25, >25 μM for MDA-MB-468, MDA-MB-231, HepG2, A549, U251, HCT116 cells, respectively. Western Blot Analysis [1] Cell Line: MDA-MB-468 cells Concentration: 0, 0.2, 1.0, 5.0 μM Incubation Time: 24 h Result: Inhibited the activation of STAT3 (Tyr705) without influencing the phosphorylation of STAT1 (Tyr701). Apoptosis Analysis [1] Cell Line: MDA-MB-468 cells Concentration: 0, 0.2, 1 μM Incubation Time: 24 h Result: Induced apoptosis through the mitochondrial Caspase dependent apoptotic pathway. Cell Cycle Analysis [1] Cell Line: MDA-MB-468 cells Concentration: 0, 0.2, 1 μM Incubation Time: 24 h Result: Cells were arrest at the G2/M phase in a dose-dependent manner.