Background and Purpose:Dysregulation of the IL‐6/glycoprotein 130(gp130)/STAT3 signalling axis is implicated in several human diseases, particularly cancer. Notably, gp130, a single transducer of this signalling axis, is a target for ovarian cancer treatment. However, data regarding small‐molecule inhibitors of gp130 are lacking. Therefore, we aimed to identify a 3‐(1,3‐diarylallylidene)oxindole derivative that binds gp130 and reveal the anticancer mechanism acting on the IL‐6/gp130/STAT3 pathway in ovarian cancer.
Experimental Approach:We synthesised 24 derivatives based on the scaffold of 3‐(1,3‐diarylallylidene)oxindole, and derivatives that inhibit IL‐6 signalling were selected using HEK‐Blue™ IL‐6 cells. The binding of derivatives to gp130 was assessed using surface plasmon resonance. IA‐0130, with a strong gp130‐binding ability, was selected to observe its effect on the migration, invasion, cell cycle arrest and apoptosis of ovarian cancer cells in comparison to bazedoxifene, a known gp130‐binding derivative. Additionally, we examined the mechanism underlying the tumour suppressive effect of IA‐0130 in vivo.
Key Results:We found that IA‐0130 inhibited gp130/STAT3 phosphorylation in a concentration‐dependent manner in ovarian cancer cell line and also in ovarian cancer‐resistant cell line. By suppressing the expression of downstream target genes, IA‐0130 inhibited cancer cell growth, metastasis, and invasion and induced apoptosis, exhibiting anticancer effects. In a mouse xenograft model of human ovarian cancer, oral administration of IA‐0130 significantly delayed tumour growth.Conclusions and ImplicationsIA‐0130 inhibits tumour growth, migration and metastasis by inhibiting IL‐6/gp130/STAT3 signalling in ovarian cancer by binding gp130. IA‐0130 holds therapeutic potential for treating ovarian cancer as well as anticancer drug‐resistant ovarian cancer.