Growth inhibition and differentiation of the human colon carcinoma cell line, Caco-2, by constitutive expression of insulin-like growth factor binding protein-3.
The human colon carcinoma cell line, Caco-2, produces insulin-like growth factor binding protein-3 (IGFBP-3), the secretion of which correlates with markers of enterocyte differentiation. To investigate whether IGFBP-3 inhibits proliferation or induces differentiation, Caco-2 cells were stably transfected with an IGFBP-3 cDNA expression construct or pcDNA3 vector as a control. Accumulation of IGFBP-3 mRNA and secretion of the protein into conditioned medium 9 days after plating were readily detected in the transfected cells, whereas these parameters were undetectable in pcDNA3-transfected cells. Insulin-like growth factor binding protein-3-expressing cells grew at a rate similar to the controls for 6 days after plating, but achieved a much lower final density between days 10 and 12. By day 9 of culture, accumulation of sucrase-isomaltase mRNA, a marker of enterocytic differentiation of Caco-2 cells, was evident in the IGFBP-3-expressing cells, but was undetectable in the controls. These results indicate that IGFBP-3 may inhibit proliferation and induce early differentiation of Caco-2 cells.
Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, USA.
R G
RG
MacDonald
B S
BS
Schaffer
I J
IJ
Kang
S M
SM
Hong
E J
EJ
Kim
J H
JH
Park
D015152:Blotting, Northern; D018938:Caco-2 Cells; D002454:Cell Differentiation; D002455:Cell Division; D002999:Clone Cells; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D017077:Culture Media, Conditioned / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D008970:Molecular Weight; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
D017077:Culture Media, Conditioned; D018076:DNA, Complementary; D018972:Insulin-Like Growth Factor Binding Protein 3; D012333:RNA, Messenger