SC144 hydrochloride, a first-in-class, orally active, small-molecule gp130 (IL6-beta) inhibitor, demonstrates potent inhibition of gp130 ligand-triggered signaling. By binding to gp130, it initiates gp130 phosphorylation (S782) and deglycosylation, impedes Stat3 phosphorylation and nuclear translocation, and suppresses the expression of downstream target genes. Furthermore, SC144 hydrochloride effectively induces apoptosis in human ovarian cancer cells [1].

SC144 inhibits cell growth in a panel of human ovarian cancer cell lines with IC 50 s in a submicromolar range (IC 50 =OVCAR-8, OVCAR-5, OVCAR-3= 0.72, 0.49, 0.95 μM) [1]. The potency of SC144 against NCI/ADR-RES (Paclitaxel- and Doxorubicin-resistant, IC 50 =0.43 μM) and HEY (Cisplatin-resistant, IC 50 =0.88 μM) demonstrates an ability to overcome drug resistance in ovarian cancer [1]. SC144 (2 μM; 24 hours) causes significantly more apoptosis in OVCAR-8 and Caov-3 than normal kidney epithelial and normal endometrial cells [1]. SC144 (0.5-2 μM; 0-6 hours) substantially increases the phosphorylation of gp130 (S782) in both OVCAR-8 and Caov-3 cells in a time- and dose-dependent manner [1]. SC144 is cytotoxic to ovarian cancer cells via a mechanism involving the inhibition of gp130 activity, leading to the inactivation of Akt and Stat3 as well as the suppression of Stat3-regulated gene expression. As are result, SC144 treatment eventually causes cell-cycle arrest, anti-angiogenesis, and apoptosis [1]. Apoptosis Analysis [1] Cell Line: OVCAR-8 and Caov-3 cells Concentration: 2 μM Incubation Time: 24 hours Result: Significantly caused cell death in OVCAR-8 and Caov-3 cells. Western Blot Analysis [1] Cell Line: OVCAR-8, Caov-3 cells Concentration: 0.5-2 μM Incubation Time: 0-6 hours Result: Substantially increased the phosphorylation of gp130 (S782) in both OVCAR-8 and Caov-3 cellsin a time- and dose-dependent manner.

SC144 (10 mg/kg; i.p.; daily for 58 days) delays tumor growth in human ovariancancer xenografts [1]. SC144 (100 mg/kg; p.o.; daily for 35 days) treatment shows the average tumor volume in mice 82% smaller than that in the control group [1]. Animal Model: Athymic mice (human ovarian cancer xenograft) [1] Dosage: I.p; daily for 58 days Administration: 10 mg/kg Result: Significantly inhibited tumor growth by about 73%.