Nifuroxazide is an effective inhibitor of STAT3, also exerts potent anti-tumor and anti-metastasis activity.
When U266 cells are incubated with Nifuroxazide, a significant dose-dependent decrease in STAT3 tyrosine phosphorylation is observed. This inhibition of STAT3 tyrosine phosphorylation is rapid, occurring as early as 1 h after treatment, and is sustained for at least 24 h. Treatment of U266 or INA6 cells with Nifuroxazide for 48 hours result in a dose-dependent loss of cell viability with an EC50 of approximately 4.5 μM in both cell types. Notably, the MM cells lacking constitutive STAT3 activation show little toxicity to Nifuroxazide[1].
Compared with the vehicle group, treatment with Nifuroxazide could inhibit tumor growth and tumor weight in a dose-dependent manner, with the inhibition rate of tumor volumes being 43.0% and 62.1% at 25 mg/kg and 50 mg/kg, respectively. It is also shown that Nifuroxazide significantly inhibits the proliferation of nuclear Ki-67-positive cells and induces apoptosis cells of cleaved caspase-3-positive cells. Besides, it is found that treatment with Nifuroxazide could inhibit the expression of MMP-2, MMP-9 and p-Stat3 in A375 tumor tissues. What’s more, Nifuroxazide inhibits the infiltration of MDSCs into the lung, which might be associated with suppression of distant colonization of tumor cells in B16-F10 melanoma metastasis model[2].
References:
[1]. Nelson EA, et al. Nifuroxazide inhibits survival of multiple myeloma cells by directly inhibiting STAT3. Blood. 2008 Dec 15;112(13):5095-102.
[2]. Zhu Y, et al. Nifuroxazide exerts potent anti-tumor and anti-metastasis activity in melanoma. Sci Rep. 2016 Feb 2;6:20253.