Amentoflavone inhibits tumor necrosis factor-α-induced migration and invasion through AKT/mTOR/S6k1/hedgehog signaling in human breast cancer

Inflammatory cytokine tumor necrosis factor-alpha (TNF alpha) has been demonstrated to accelerate the progression and metastasis of various carcinomas. In this study, we investigated the effect of amentoflavone on inhibiting the migration and invasion of TNF alpha-induced breast cancer cells. Results showed that amentoflavone significantly blocked the cellular migration and invasion of MCF10DCIS.com and MDA-MB-231 cells at a concentration of 10 mu M but did not affect the cell viability. The mRNA and protein levels of matrix metalloproteinase (MMP)-9, significantly activated by TNF alpha, were reversed by amentoflavone treatment in a dose-dependent manner in MCF10DCIS.com cells. Congruent with the protein level, the activity of MMP-9 was significantly suppressed by amentoflavone treatment. Additionally, we found that amentoflavone dampened Gli1-dependent noncanonical hedgehog signaling, which is a key factor in the regulation of migration and invasion in TNF alpha-induced human breast cancer cells. Further study elucidated that TNF alpha enhanced Gli1 through the activation of the AKT/mTOR/S6K1 cascade, whereas it receded after amentoflavone treatment in human breast cancer cells. In summary, amentoflavone abrogated Gli1 activation in TNF alpha-induced mammary tumor cells, resulting in a decrease of invasiveness in human breast cancer cells via mediating AKT/mTOR/S6K1 signaling. Amentoflavone should be considered as a potent food ingredient for the retardation of mammary tumorigenesis.