Napabucasin

Napabucasin (BBI608) is a STAT3 inhibitor which blocks stem cell activity in cancer cells. IC50 & Target: STAT3^[1] In Vitro: Napabucasin inhibits the expressions of stemness markers and kill stemness-high cancer cells isolated from several kinds of tumors except PCa. Napabucasin not only inhibits cell proliferation, cell motility, cell survival, colony formation ability, and tumorigenic potential of PCa cells, and increases cell apoptosis and sensitivity to docetaxel, but also effectively blocks sphere formation of PrCSCs and kill them as well as inhibits stemness gene expression. Napabucasin inhibits cell proliferation in PC-3 cells and 22RV1 cells at 48, 72, 96, and 120 h (P<0.05). Cell motility and colony formation ability are closely correlated with the process of tumor metastasis. Napabucasin significantly decreases colony formation and cell motility ability of PCa cell lines in vitro (P<0.05). The proliferation of PC-3 and 22RV1 cells treated with 1 μM Napabucasin are significantly decreased from day 2 to 5 compared with the control group (P<0.05)^[1]. In Vivo: Napabucasin (40 mg/kg) or Docetaxel significantly reduces xenograft tumor growth and tumor volume (TV) compared with PBS (P<0.05). Notably, while no differences are observed between the Napabucasin and the docetaxel groups in PC-3 mouse xenograft models, the TV in Napabucasin group is even lower than docetaxel group in 22RV1 mouse xenograft models (P<0.05). Additionally, Napabucasin or docetaxel also significantly reduces tumor weight compared with PBS (P<0.05)^[1].