The Natural Flavonoid Naringenin Inhibits the Cell Growth of Wilms Tumor in Children by Suppressing TLR4/NF-κB Signaling

Abstract

Background: Nuclear Factor-kappa B (NF-κB) is usually activated in Wilms Tumor (WT) cells and plays a critical role in WT development.

Objective: The study's purpose was to screen for a NF-κB inhibitor from the natural product library and explore its effects on WT development.

Methods: Luciferase assay was employed to assess the effects of natural chemicals on NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively.

Results: Naringenin displayed a significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SKNEP- 1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α- induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in doseand time-dependent manner, whereas Toll-Like Receptor 4 (TLR4) overexpression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in a dose- and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors.

Conclusion: Naringenin inhibits WT development via suppressing TLR4/NF-κB signaling.

Keywords: NF-κB; Naringenin; TLR4; flavonoids; luciferase assay; wilms tumor.