Transcriptional repression of the human collagenase-1 (MMP-1) gene in MDA231 breast cancer cells by all-trans-retinoic acid requires distal regions of the promoter.
In the present study, we investigated the mechanisms controlling constitutive transcription of collagenase-1 and its repression by all-trans-retinoic acid (RA) in the highly invasive metastatic and oestrogen-receptor-negative breast cancer cell line MDA231. A combination of in vivo and in vitro experiments that include DNAase I hypersensitivity assays, transient transfection of collagenase-1 promoter constructs, and electrophoretic mobility shift assays implicate several PEA3 sites, binding sites for Ets-related transcription factors, in the constitutive expression of the human collagenase-1 promoter. Transient transfection of promoter constructs linked to the luciferase reporter, along with gel retardation assays, revealed that repression of collagenase-1 transcription by RA is not dependent on the proximal AP-1 site, but, rather, requires sequences located in distal regions of the promoter. Transcriptional analyses and electrophoretic mobility shift assays suggest that the PEA3 site located at -3108 bp facilitates, at least in part, the transcriptional repression of the human collagenase-1 gene in MDA231 cells. We conclude that collagenase-1 repression in MDA231 cells occurs by a novel regulatory pathway that does not depend on the proximal AP-1 site at -73 bp, but does depend on distal regions in the collagenase-1 promoter.
Benbow
U
U
Department of Medicine, Dartmouth Medical School, Hanover NH 03755, USA.
Rutter
J L
JL
Lowrey
C H
CH
Brinckerhoff
C E
CE
D017364:Collagenases / Q000096:biosynthesis* / Q000235:genetics; D003850:Deoxyribonuclease I / Q000494:pharmacology; D004794:Enzyme Repression / Q000235:genetics; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D020781:Matrix Metalloproteinase 1; D061965:Matrix Metalloproteinase Inhibitors; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic; D018168:Receptors, Retinoic Acid / Q000187:drug effects* / Q000378:metabolism; D000072482:Retinoic Acid Receptor alpha; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured / Q000187:drug effects; D000097768:Retinoic Acid Receptor gamma
D017364:Collagenases; D003850:Deoxyribonuclease I; D020781:Matrix Metalloproteinase 1; D061965:Matrix Metalloproteinase Inhibitors; D009363:Neoplasm Proteins; D018168:Receptors, Retinoic Acid; D000072482:Retinoic Acid Receptor alpha; D014212:Tretinoin; D000097768:Retinoic Acid Receptor gamma; C000607071:RARA protein, human; C082925:retinoic acid receptor beta