Abstract
Basic fibroblast growth factor (bFGF) is dependent on heparan sulphate for its ability to activate the cell surface signal transducing receptor. We have investigated the FGF dual receptor mechanism in a novel model of the transformation from human colon adenoma to carcinoma in vitro. Reverse transcription-polymerase chain reaction showed that mRNA for FGF receptors 1 and 2 were expressed in both the adenoma and carcinoma cells whereas immunocytochemistry showed that the expression of the FGF R1 was reduced significantly in the carcinoma cells. We have reported previously that the composition and sequence of human colon adenoma and carcinoma heparan sulphate (HS) differ in a defined and specific manner. The functional significance of these changes was assessed by affinity co-electrophoresis, which showed that the affinity of adenoma HS for bFGF was 10-fold greater than that of the carcinoma HS (Kd 220 nM vs. 2493 nM, respectively). In addition, Northern studies of the expression of syndecan 1 and 4 mRNA showed that proteoglycan core protein expression was reduced significantly in the carcinoma cells. These findings were associated with a reduced biological response to bFGF in the carcinoma cells that could be partially reversed by the addition of exogenous heparin, suggesting that both the proteoglycan and signal transducing receptor control the cells' response to bFGF.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenoma / genetics*
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Adenoma / pathology
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Carcinoma / genetics*
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Carcinoma / pathology
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Colonic Neoplasms / genetics*
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Colonic Neoplasms / pathology
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Disease Progression
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Down-Regulation / drug effects
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Fibroblast Growth Factor 2 / pharmacology
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Fibroblast Growth Factors / pharmacology*
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Gene Expression Regulation, Neoplastic* / drug effects
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Heparin / pharmacology
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Heparitin Sulfate / physiology*
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Humans
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Neoplasm Proteins / biosynthesis*
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Neoplasm Proteins / genetics
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Proteoglycans / physiology
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RNA, Messenger / biosynthesis
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RNA, Messenger / genetics
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RNA, Neoplasm / biosynthesis
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RNA, Neoplasm / genetics
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Receptor Protein-Tyrosine Kinases / biosynthesis*
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Receptor Protein-Tyrosine Kinases / genetics
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Receptor, Fibroblast Growth Factor, Type 1
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Receptor, Fibroblast Growth Factor, Type 2
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Receptors, Fibroblast Growth Factor / biosynthesis*
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Receptors, Fibroblast Growth Factor / genetics
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Reverse Transcriptase Polymerase Chain Reaction
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Signal Transduction
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Tumor Cells, Cultured / drug effects
Substances
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Neoplasm Proteins
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Proteoglycans
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RNA, Messenger
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RNA, Neoplasm
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Receptors, Fibroblast Growth Factor
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Fibroblast Growth Factor 2
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Fibroblast Growth Factors
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Heparin
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Heparitin Sulfate
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FGFR1 protein, human
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FGFR2 protein, human
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Receptor Protein-Tyrosine Kinases
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Receptor, Fibroblast Growth Factor, Type 1
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Receptor, Fibroblast Growth Factor, Type 2