Objective: To investigate whether inhibition of Akt phosphorylation by the phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin, reduces metastasis and angiogenesis in a human breast cancer cell line via nuclear factor (NF)-κB-dependent matrix metalloproteinase (MMP)-9 and interleukin (IL)-8 pathways.
Methods: MDA-MB-231 cells were treated with wortmannin 0-200 nM for 4 h. Restoration of Akt activity was evaluated by transfection of cells with constitutively active myristoylated Akt (myr-Akt). NF-κB, MMP-9 and IL-8 proteins were detected by electrophoretic mobility shift assay, Western blot or enzyme-linked immunosorbent assay. The chicken embryo chorio-allantoic membrane assay, cell motility and migration assays were used to evaluate angiogenesis and invasion in vitro. A mouse pseudo metastatic breast cancer model was used to assess the effects of wortmannin on metastasis and angiogenesis in vivo.
Results: Wortmannin inhibited the phosphorylation of Akt, upregulation of NF-κB, MMP-9, IL-8, and in vitro cell invasion and angiogenesis, in a dose-dependent manner. Transfection of myr-Akt reversed the cellular and biochemical effects of wortmannin in vitro. Wortmannin also significantly inhibited tumour metastasis and angiogenesis in vivo.
Conclusion: The findings of the present study suggest that wortmannin inhibits metastasis and angiogenesis in breast cancer cells via PI3K/Akt/NF-κB-mediated MMP-9 and IL-8 signalling pathways.