FGF-1-induced matrix metalloproteinase-9 expression in breast cancer cells is mediated by increased activities of NF-kappaB and activating protein-1.
Matrix metalloproteinase-9 (MMP-9) plays a critical role in tumor invasion and metastasis. Here, we investigate the effect of fibroblast growth factor-1 (FGF-1) on the expression of MMP-9 in ENU1564, an ethyl-N-nitrosourea-induced rat mammary adenocarcinoma cell line. We observed that FGF-1 induces a dose-dependent increase in MMP-9 mRNA, protein, and activity in ENU1564 cells. To gain insight into the molecular mechanism of MMP-9 regulation by FGF-1, we investigated the role of components of PI3K-Akt and MEK1/2-ERK signaling pathways in our system since NF-kappaB and AP-1 transcription factor binding sites have been characterized in the upstream region of the MMP-9 gene. We demonstrated that FGF-1 increases Akt phosphorylation, triggers nuclear translocation of NF-kappaBp65, and enhances degradation of cytoplasmic IkappaBalpha. Pretreatment of cells with LY294002, a PI3K inhibitor, significantly inhibited MMP-9 protein expression in FGF-1-treated cells. Conversely, our data show that FGF-1 increases ERK phosphorylation in ENU1564 cells, increases c-jun and c-fos mRNA expression in a time-dependent manner, and triggers nuclear translocation of c-jun. Pretreatment of cells with PD98059, a MEK1/2 inhibitor significantly inhibited MMP-9 protein expression in FGF-1 treated cells. Finally, we observed increased DNA binding of NF-kappaB and AP-1 in FGF-1-treated cells and that mutation of either NF-kappaB or AP-1 response elements prevented MMP-9 promoter activation by FGF-1. Taken together, these results demonstrated that FGF-1-induced MMP-9 expression in ENU1564 cells is associated with increasing DNA binding activities of NF-kappaB and AP-1 and involve activation of a dual signaling pathway, PI3K-Akt and MEK1/2-ERK.
Lungu
Gina
G
Department of Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, Texas 77843, USA.
Covaleda
Lina
L
Mendes
Odete
O
Martini-Stoica
Heidi
H
Stoica
George
G
D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002273:Carcinogens / Q000633:toxicity; D045744:Cell Line, Tumor; D002867:Chromones / Q000494:pharmacology; D003001:Cloning, Molecular; D017931:DNA Primers; D005038:Ethylnitrosourea / Q000633:toxicity; D005260:Female; D016220:Fibroblast Growth Factor 1 / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D016762:Genes, fos; D016758:Genes, jun; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000235:genetics / Q000378:metabolism*; D009025:Morpholines / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018808:Transcription Factor AP-1 / Q000378:metabolism*
D002273:Carcinogens; D002867:Chromones; D017931:DNA Primers; D005419:Flavonoids; D009025:Morpholines; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D016220:Fibroblast Growth Factor 1; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D020780:Matrix Metalloproteinase 9; D005038:Ethylnitrosourea; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one