MMP-2 mediates ethanol-induced invasion of mammary epithelial cells over-expressing ErbB2.
Ethanol is a tumor promoter and may enhance the metastasis of breast cancer. We have previously demonstrated that over-expression of ErbB2 promoted ethanol-mediated invasion of mammary epithelial cells and breast cancer cells. However, the underlying cellular/molecular mechanisms remain unknown. By gelatin zymography, we showed that over-expression of ErbB2 increased the production of matrix metalloproteinase-2 (MMP-2) and MMP-9 in human mammary epithelial cells (HB2). Transient or stable transfection of ErbB2 cDNA to HB2 cells upregulated the transcripts and the activity of the MMP-2/-9 gene promoter; the upregulation of MMP-2/-9 expression was mediated by p38 mitogen-activated protein kinase (p38 MAPK) and phosphatidylinositol 3-kinase (PI3K). Although ethanol, at physiologically relevant concentrations (100-400 mg/dl), did not affect the production of MMP-2/-9, it activated MMP-2 in HB2 cells over-expressing ErbB2 (HB2(ErbB2)), but not HB2 cells; it enhanced the cleavage of proform MMP-2 (72 kDa) to an active form (62 kDa). The activation was dependent on c-jun N-terminal kinases (JNKs) and reactive oxygen species (ROS). On the other hand, ethanol affected neither the expression nor the activation of MMP-9. Selective inhibitors of MMP-2 (SB-3CT and OA-Hy) and antioxidants significantly inhibited ethanol-stimulated invasion of HB2(ErbB2) cells. Furthermore, knocking down MMP-2 by small interference RNA also induced a partial blockage on ethanol-promoted invasion of HB2(ErbB2) cells. Thus, ethanol-stimulated invasion of cells over-expressing ErbB2 was mediated, at least partially, by MMP-2 activation.
Ke
Zunji
Z
Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, People's Republic of China.
Lin
Hong
H
Fan
Zhiqin
Z
Cai
Tian-Quan
TQ
Kaplan
Rebecca A
RA
Ma
Cuiling
C
Bower
Kimberly A
KA
Shi
Xianglin
X
Luo
Jia
J
D015153:Blotting, Western; D018929:Cell Culture Techniques; D004847:Epithelial Cells / Q000201:enzymology; D000431:Ethanol / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation; D018734:Genes, erbB-2; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D042361:Mammary Glands, Human / Q000166:cytology / Q000201:enzymology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics; D014158:Transcription, Genetic; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D000431:Ethanol; D048031:JNK Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; D019869:Phosphatidylinositol 3-Kinases; D017382:Reactive Oxygen Species; D018719:Erb-b2 Receptor Tyrosine Kinases; D048051:p38 Mitogen-Activated Protein Kinases