Dominant-negative CREB inhibits heparanase functionality and melanoma cell invasion.
Heparanase (HPSE-1) is an endo-beta-D-glucuronidase involved in the degradation of cell-surface/extracellular matrix heparan sulfate (HS) in normal and neoplastic tissues. HPSE-1 represents the first example of purification and cloning of a mammalian HS-degradative enzyme. Elevated HPSE-1 levels are known to be associated with metastatic cancers, directly implicating HPSE-1 in metastatic events. The purpose of this study was to determine the role of cAMP response element-binding protein (CREB) in modulating HPSE-1-mediated effects on human melanoma cell invasion. Highly invasive, brain-metastatic melanoma cells (70W) were transfected with the dominant-negative CREB (KCREB) and subsequently analyzed for changes in their HPSE-1 content, functionality, and cell invasive properties. KCREB-transfected cells showed a decrease in HPSE-1 mRNA expression and activity. This correlated with a significantly decreased invasion of these cells through Matrigel-coated filters. Furthermore, adenoviral vectors containing the full-length human HPSE-1 cDNA in sense orientation (Ad-S/hep) were constructed to investigate CREB effects on HPSE-1. Restoration of HPSE-1 expression and functionality following Ad-S/hep infection of KCREB-transfected 70W cells recovered melanoma cell invasiveness. These results demonstrate that KCREB inhibits HPSE-1 and suggest that one of the roles CREB plays in the acquisition of melanoma cells metastatic phenotype is affecting HPSE-1 activity.
Aucoin
Rebecca
R
Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University-Baton Rouge, Baton Rouge, Louisiana 70803, USA.
Reiland
Jane
J
Roy
Madhuchhanda
M
Marchetti
Dario
D
D000256:Adenoviridae / Q000235:genetics; D045744:Cell Line, Tumor; D003094:Collagen; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D004338:Drug Combinations; D015972:Gene Expression Regulation, Neoplastic; D005799:Genes, Dominant / Q000235:genetics; D005966:Glucuronidase / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007797:Laminin; D008545:Melanoma / Q000201:enzymology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D009154:Mutation / Q000235:genetics; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D011509:Proteoglycans; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000099175:Heparanase
D003094:Collagen; D000242:Cyclic AMP; D017362:Cyclic AMP Response Element-Binding Protein; D018076:DNA, Complementary; D004338:Drug Combinations; D005966:Glucuronidase; D007797:Laminin; D011509:Proteoglycans; D012333:RNA, Messenger; D000099175:Heparanase; C059485:matrigel