TY - JOUR
T1 - Identification of glycosylated 38-kDa connective tissue growth factor (IGFBP-related protein 2) and proteolytic fragments in human biological fluids, and up-regulation of IGFBP-rP2 expression by TFG-β in Hs578T human breast cancer cells
AU - Yang, Doo Hyun
AU - Kim, Ho Seong
AU - Wilson, Elizabeth M.
AU - Rosenfeld, Ron G.
AU - Oh, Youngman
PY - 1998
Y1 - 1998
N2 - Connective Tissue Growth Factor (CTGF) is a cysteine-rich peptide involved in human atherosclerosis and fibrotic disorders such as scleroderma. CTGF has considerable N-terminal sequence similarity with the insulin-like growth factor binding proteins (IGFBPs), including preservation of cysteines, and has been postulated to be a member of the IGFBP superfamily. Indeed, recent studies have shown that baculovirus generated CTGF, a secreted 38-kDa protein, binds IGFs in a specific manner, leading to the provisional renaming of CTGF as IGFBP-8 (or IGFBP-rP2). With immunoprecipitation and immunoblotting, using polyclonal anti-IGFBP-rP2 antibody generated against recombinant human IGFBP-rP2(bac), IGFBP-rP2 can be identified in the serum- free conditioned media of Hs578T human breast cancer cells, as well as in various human biological fluids, such as normal sera, pregnancy sera, and cerebrospinal, amniotic, follicular and peritoneal fluids. Glycosylation studies with endoglycosidase F reveal that endogenous human IGFBP-rP2 is a secreted, glycosylated, approximately 32-38-kDa protein with 2-8-kDa of N- linked sugars and a 30-kDa core. There are 18- and 24-kDa proteins that appear to be IGFBP-rP2 degradation products. In Hs578T human breast cancer cells, transforming growth factor (TGF)-β2, a potent growth inhibitor for these cells, upregulates tGFBP-rP2 mRNA and protein levels. Expression of Hs578T IGFBP-rP2 is significantly increased by TGF-β2 treatment in a dose- dependent manner, with 2.5- and 6-fold increases in mRNA and protein levels, respectively, at a TGF-β2 concentration of 10 ng/ml. Our studies indicate that IGFBP-rP2 appears to be an important endocrine factor, and one of the critical downstream effectors of TGF-β, similar to the role of IGFBP-3 in TGF-β-induced growth inhibition in human breast cancer cells.
AB - Connective Tissue Growth Factor (CTGF) is a cysteine-rich peptide involved in human atherosclerosis and fibrotic disorders such as scleroderma. CTGF has considerable N-terminal sequence similarity with the insulin-like growth factor binding proteins (IGFBPs), including preservation of cysteines, and has been postulated to be a member of the IGFBP superfamily. Indeed, recent studies have shown that baculovirus generated CTGF, a secreted 38-kDa protein, binds IGFs in a specific manner, leading to the provisional renaming of CTGF as IGFBP-8 (or IGFBP-rP2). With immunoprecipitation and immunoblotting, using polyclonal anti-IGFBP-rP2 antibody generated against recombinant human IGFBP-rP2(bac), IGFBP-rP2 can be identified in the serum- free conditioned media of Hs578T human breast cancer cells, as well as in various human biological fluids, such as normal sera, pregnancy sera, and cerebrospinal, amniotic, follicular and peritoneal fluids. Glycosylation studies with endoglycosidase F reveal that endogenous human IGFBP-rP2 is a secreted, glycosylated, approximately 32-38-kDa protein with 2-8-kDa of N- linked sugars and a 30-kDa core. There are 18- and 24-kDa proteins that appear to be IGFBP-rP2 degradation products. In Hs578T human breast cancer cells, transforming growth factor (TGF)-β2, a potent growth inhibitor for these cells, upregulates tGFBP-rP2 mRNA and protein levels. Expression of Hs578T IGFBP-rP2 is significantly increased by TGF-β2 treatment in a dose- dependent manner, with 2.5- and 6-fold increases in mRNA and protein levels, respectively, at a TGF-β2 concentration of 10 ng/ml. Our studies indicate that IGFBP-rP2 appears to be an important endocrine factor, and one of the critical downstream effectors of TGF-β, similar to the role of IGFBP-3 in TGF-β-induced growth inhibition in human breast cancer cells.
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U2 - 10.1210/jc.83.7.2593
DO - 10.1210/jc.83.7.2593
M3 - Article
C2 - 9661651
AN - SCOPUS:0031786081
SN - 0021-972X
VL - 83
SP - 2593
EP - 2596
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 7
ER -