Koelreuteria formosana ethanolic extract (KFEE) is obtained from natural plants that are endemic to Taiwan. In a previous study, it was demonstrated that KFEE inhibited low-density lipoprotein (LDL) and prevented oxidized LDL‑induced apoptosis in endothelial cells. In the present study, KFEE was shown to inhibit the invasion and migration of 786‑O‑SI3 renal cell carcinoma (RCC) cells while not exhibiting any cytotoxic effects. 786‑O‑SI3 cells were treated with KFEE at numerous concentrations of ≤100 µg/ml for 24 h. In order to examine the effects of KFEE, cells were then subjected to a series of assays for cell viability (MTT), wound healing migration, cell invasion and migration, gelatin zymography, casein zymography and immunofluorescence, as well as western blot analysis. KFEE was shown to decrease levels of matrix metalloproteinase‑2, phosphorylated (p‑)focal adhesion kinase Try925, p‑paxillin Ser178, p‑mitogen‑activated protein kinase kinase 1/2, p‑myosin light chain and p‑extracellular signal-regulated kinase 1/2 in 786-0-SI3 cells. Reduction of lung metastases was observed in KFEE-treated mice compared with vehicle‑treated control mice. KFEE inhibited the invasion of RCC cells and may have the potential for use as a chemopreventive agent against RCC metastasis.
