Metastasis Wortmannin side effects of cancer cells to the neck lymph nodes, which can occur in up to 75% of NPC patients, represents an adverse prognostic factor of the disease. Distant metastases, such as those to the lungs, liver, and bone, remain a major cause of treatment failure. Metastasis is a phenomenon composed of multiple se quential cascades and various cyto physiologic changes, including reduction of tumor cell adhesion, degradation of extracellular matrix, enhancement of cell motility, and promotion of neo vascularization. Thus, a degrad ation of the ECM and components of the basement mem brane caused by the concerted action of proteinases like matrix metalloproteinases, cathepsins, and plas minogen activators play an important role in tumor invasion and metastasis.

Among these enzymes, MMP 2 and MMP 9 can degrade most ECM components and are profoundly involved in the development of cancer invasion and metastasis. Therefore, the inhibition of MMP 2 or MMP 9 mediated migration or invasion may be a preventive method of limiting cancer metastasis. Selaginella tamariscina is a traditional Chinese herbal medicine for chronic trachitis. Its major constitu ents are flavonoids. Previous studies have demonstrated that Selaginella tamariscina possesses anti bacterial, anti hypertensive, and anti hyperglycemic effects. Moreover, Selaginella tamariscina has been shown to have anti tumor activities, probably via an expression of the p53 tumor suppressor gene and an induction of G1 arrest in the cell cycle against certain tumor cell lines. Recently, Yang et al.

found that Selaginella tamariscina extract can down regulate the expression of MMPs and u PA, and inhibit the invasion and metastatic activities of lung cancer cells. There is, however, no data about the anti metastatic potential of STE on NPC cancer cells. Thus, this study examined the effects of aqueous extracts of Selaginella tamariscina with potential anti metastatic properties in 12 O tetradecanoylphorbol 13 acetate treated hu man NPC HONE 1 cells in vitro to investigate the signal ing pathway of the process. Methods Preparation of Selaginella tamariscina extracts Selaginella tamariscina leaves were purchased from herb stores in Taichung, Taiwan and the Selaginella tamariscina extracts were prepared as described previously. The plant material was identified at the Department of Biochemistry of Chung Shan Medical University in Taichung and a voucher specimen is depos ited.

Briefly, 100 g of air dried leaves were boiled at 70 C for 24 hours with 500 mL of 50% ethanol. The extraction procedure was repeated twice. The solvent was removed from the combined extract using a vacuum rotary evapor ator. The filtrate was then lyophilized and stored at ?20 C until further studies were to be conducted. Anacetrapib A voucher spe cimen was deposited in the National Research Institute of Chinese Medicine, Taiwan. The extraction yield was 2.