Regulation of sucrase and lactase in caco-2 cells: relationship to nuclear factors sif1 and nf-lph1. Olsen, Ward A., Mark Lloyd, Helen Korsmo, and Yu-Zhu He. Gastroenterology Research Laboratory, William S. Middleton Memorial Veterans Hospital and the Department of Medicine, University of Wisconsin, Madison, WI 53705
APStracts 3:0065G, 1996.
Recent studies suggest the importance of two transcription factors, Cdx-2 and NF-LPH1, in the regulation of sucrase-isomaltase (SI) and lactase-phlorizin hydrolase (LPH) gene expression respectively. Cdx-2 has been found to account for the tissue specificity of sucrase expression (16), and NF-LPH1 has been found to vary with postnatal changes in lactase activity suggesting a role in its developmental regulation (22). We used electrophoretic mobility shift assays to study the relationship of Cdx-2 and NF-LPH1 to SI and LPH gene expression in Caco-2 cells to provide evidence regarding the role of these factors in the development of sucrase and lactase with cellular differentiation. We found that Cdx-2 levels correlated with SI expression and that NF-LPH1 did not correlate with LPH expression. These studies suggest a role for Cdx-2 but not for NF-LPH1 in the development of carbohydrase expression in these cells.

Received 17 July 1995; accepted in final form 16 March 1996.
APS Manuscript Number G294-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 April 96