Insulin-like growth factor binding protein-4 expression is dependent on the carbohydrate in the media in HT-29 cells.
HT-29 are colonic carcinoma cells that follow a unique pattern of differentiation dependent on the medium's carbohydrate source. This study compared levels of insulin-like growth factor (IGF)-II and IGF binding protein (IGFBP)-4 when HT-29 cells were grown with standard glucose-containing medium versus galactose-containing (glucose-free) medium. Serum-free media conditioned for 24h were collected at low density, pre-confluence, confluence, and 48-h post-confluence. Ligand blotting of the conditioned galactose medium demonstrated low IGFBP-4 levels until the cells approached confluence, when the levels increased significantly. In standard medium, IGFBP-4 levels increased with increasing cell numbers except for a transient decrease at confluence. Radioimmunoassay showed little change in IGF-II concentrations, although HT-29 cells grown with galactose had lower IGF-II concentrations. HT-29 cells treated with retinoic acid had dose-dependent increases in IGFBP-4 and reduced IGF-II expression. These studies suggest that HT-29 cell differentiation correlates with an increase in IGFBP-4 levels.
Corkins
Mark R
MR
Division of Pediatric Gastroenterology, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA. mrcorkin@pol.net
McQuade
Jennifer
J
Schaffer
Beverly S
BS
MacDonald
Richard G
RG
D050260:Carbohydrate Metabolism; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D003470:Culture Media; D020895:Enterocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D011266:Pregnancy-Associated Plasma Protein-A; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014212:Tretinoin / Q000494:pharmacology
D003470:Culture Media; D018974:Insulin-Like Growth Factor Binding Protein 4; D012333:RNA, Messenger; D014212:Tretinoin; D007335:Insulin-Like Growth Factor II; D008666:Metalloendopeptidases; D011266:Pregnancy-Associated Plasma Protein-A