This study was approved by the Ethics Committee of Korea University, and all experimental animals used herein were handled according to the guidelines approved by the Institutional Animal Care and Use Committee of Korea University. All animals were maintained under a 12-h light/dark cycle and housed at a density of 5 mice per static polycarbonate microisolator cage on disposable bedding. Wire-lid food hoppers within the cages were filled to capacity with rodent chow, and water was supplied by a bottle. For the spontaneous metastasis assays, cultured MDA-MB-231 cells were treated with LY255283 (10 μM), wogonin (20 μM) or DMSO, prior to being treated with LPS (1 μg/ml) for 24 h, as described previously (13 (link)). Then, six-week-old female nude (BALB/C) mice (Daehan Biolink, Chungbuk, Korea) were injected unilaterally in the fourth right mammary fat pad with cultured MDA-MB-231 (3.5×106) cells in 100 μl of PBS; the cells were injected subcutaneously at the base of the nipple. Wogonin (20 mg/kg), LY255283 (2.5 mg/kg) or DMSO was injected intraperitoneally three times at 5-day intervals beginning immediately following cell implantation. The animals were sacrificed 14 weeks post-cell implantation, and the number of metastatic nodules on the surface of the small bowel was determined.