Silibinin prevents TPA-induced MMP-9 expression and VEGF secretion by inactivation of the Raf/MEK/ERK pathway in MCF-7 human breast cancer cells.
Matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) expression are pivotal steps in cancer metastasis. Herein, we investigated the effect of silibinin, a major constituent (flavanolignan) of the fruits of Silybum marianum, on 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced MMP-9 and VEGF expression in MCF-7 human breast cancer cells. The expression of MMP-9 and VEGF in response to TPA was increased, whereas TPA-induced MMP-9 and VEGF expression was decreased by silibinin. To investigate the regulatory mechanism of silibinin on TPA-induced MMP-9 and VEGF expression, we pretreated cells with various inhibitors, such as UO126 (MEK1/2 inhibitor), SP600125 (JNK inhibitor), and SB203580 (p38 inhibitor). Interestingly, TPA-induced MMP-9 expression was significantly inhibited by UO126, but not by SP600125 and SB203580. In addition, we pretreated cells with 100 microM silibinin prior to TPA treatment. TPA-induced MEK and ERK phosphorylation was significantly decreased by silibinin in MCF7 cells. TPA-induced VEGF expression was also suppressed by UO126. On the other hand, we found that adenoviral constitutive active-MEK (Ad-CA-MEK) significantly increased MMP-9 and VEGF expression. Taken together, we suggest that the inhibition of TPA-induced MMP-9 and VEGF expression by silibinin is mediated by the suppression of the Raf/MEK/ERK pathway in MCF-7 breast cancer cells.
Kim
Sangmin
S
Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-gu, Seoul 135-710, South Korea.
Choi
Jae Hyuck
JH
Lim
Hye In
HI
Lee
Se-Kyung
SK
Kim
Wan Wook
WW
Kim
Jee Soo
JS
Kim
Jung-Han
JH
Choe
Jun-Ho
JH
Yang
Jung-Hyun
JH
Nam
Seok Jin
SJ
Lee
Jeong Eon
JE
D015153:Blotting, Western; D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D020935:MAP Kinase Signaling System; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D000077385:Silybin; D012838:Silymarin / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D047428:Protein Kinase Inhibitors; D012838:Silymarin; D042461:Vascular Endothelial Growth Factor A; D000077385:Silybin; D020780:Matrix Metalloproteinase 9; D013755:Tetradecanoylphorbol Acetate