TGF-beta-induced transcriptional activation of MMP-2 is mediated by activating transcription factor (ATF)2 in human breast epithelial cells.
We have previously shown that transforming growth factor (TGF)-beta up-regulates matrix metalloproteinase (MMP)-2 leading to the induction of oncogenic signaling in preneoplastic MCF10A human breast epithelial cells. The present study investigated the mechanism of transcriptional regulation of MMP-2 by TGF-beta in MCF10A cells. By using 5' deletion constructs of MMP-2 promoter, we demonstrated that binding sites for p53, S1, AP-1 and Sp1, and to a lesser extent CREB, GCN-His and PEA3, were potential cis-acting elements for TGF-beta-induced transcriptional activation of MMP-2 in MCF10A cells. Since activating transcription factor (ATF)2 was shown to mediate the TGF-beta-induced cellular responses, we examined the involvement of ATF2 in TGF-beta-activated MMP-2 gene transcription. TGF-beta increased DNA binding activity of AP-1 in which ATF2 was involved as evidenced by electrophoretic mobility shift assay. TGF-beta induced phosphorylation of ATF2 through p38 MAPK signaling. A dominant-negative (DN) ATF2 significantly inhibited the TGF-beta-induced up-regulation of MMP-2, but not that of MMP-9, suggesting that ATF2 may be a transcription factor responsible for transcriptional activation of MMP-2 gene by TGF-beta. Invasive and migratory phenotypes induced by TGF-beta were significantly inhibited by DN ATF2, indicating a critical role of ATF2 in TGF-beta-induced oncogenic progression of MCF10A cells. Taken together, this study demonstrates that ATF2 mediates the TGF-beta-induced MMP-2 transcriptional activation, elucidating a molecular mechanism for the malignant progression of human breast epithelial cells exerted by TGF-beta.
Kim
Eun-Sook
ES
College of Pharmacy, Duksung Women's University, Seoul 132-714, Republic of Korea.
Sohn
Yeo-Won
YW
Moon
Aree
A
D051698:Activating Transcription Factor 2 / Q000378:metabolism*; D001665:Binding Sites; D001940:Breast / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000235:genetics*; D002460:Cell Line; D002465:Cell Movement; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D004252:DNA Mutational Analysis; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000235:genetics*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic / Q000235:genetics; D017384:Sequence Deletion; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D053781:Transforming Growth Factor beta2 / Q000494:pharmacology / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D004791:Enzyme Inhibitors; D053781:Transforming Growth Factor beta2; D048051:p38 Mitogen-Activated Protein Kinases; D020778:Matrix Metalloproteinase 2