Study of the inhibitory effect and mechanism of silibinin on osteosarcoma invasion, adhesion, and cell morphology

• Main Authors: Yu-Chuan, 劉育銓
• Other Authors: 謝易修
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/08593063865101464865

碩士 === 中山醫學大學 === 生化暨生物科技研究所 === 93 === The metastasis of cancer is a vital trait in malignance with extreme difficulties in early diagnosis and therapeutic management. Therefore, the development of new remedies or the utilization of natural medicines targeted at metastasis has been interested and studied extensively. In this study, silibinin, a flavonoid antioxidant extracted from milk thistle, was studied for this purpose. Recently, silibinin has been reported to have various anti-carcinogenesis properties, including inducing cell apoptosis. However, the in vitro effect of silibinin on metastasis of cancer cells was still unclear. Hence, a highly metastatic human osteosarcoma cancer cell line, MG-63, was chosen to be treated with various concentrations of silibinin to investigate its potential for inhibiting cancer cells invasion based on that tumor metastasis are accompanied with proteolytic degradation of the extracellular matrix, changes in cell-matrix adhesion, and regulated cell motility. For a start, via modified Boyden chamber invasion assay, we found that silibinin inhibited MG-63 cells invasion without toxicity while both of MMP-2 and u-PA activity were also inhibited by silibinin via gelatin zymography and casein zymography assay. In addition, the adhesion ability of cells was also suppressed by a treatment with silibinin. To further explore the detailed molecular mechanisms, we found that the expression of phospho-ERK1/2 was dramatically suppressed by silibinin through a western blotting. We also demonstrated that silibinin could inhibit cell invasion and suppress the expression of related molecules via ERK1/2 pathway by using ERK1/2 inhibitor U0126. After cell being treated with silibinin, cell morphology was altered to become shrank and threadlike. Immunofluorescence assay also revealed that silibinin influenced the cell cytoskeletal arrangement. Then, the effect of silibinin on cellular morphology-related proteins was also examined by western blotting to reveal that silibinin could repress FAK expression. Finally, it was concluded that silibinin may influence cell morphology and inhibit FAK expression, and further suppress cell adhesion and cell invasion.