Biomaterial Database

Regulation of Caco-2 cell proliferation by basolateral membrane epidermal growth factor receptors. 1994

W P Bishop, and J T Wen

Department of Pediatrics, University of Iowa, Iowa City 52242.

The epidermal growth factor (EGF) receptor is an important mediator of intestinal epithelial cell proliferation. We studied cell-surface localization of this molecule in Caco-2 cells and characterized cellular responses to apical or basolateral EGF stimulation. 125I-labeled EGF bound almost exclusively to a 180-kDa molecule, existing as a single high-affinity population by Scatchard analysis. On basolateral membranes 13- to 15-fold more ligand binding was seen. Apical/basolateral differences were not significantly altered by incubation with either blocking antibody to EGF receptor or transforming growth factor-alpha (TGF-alpha) neutralizing antibody. Even though apical EGF receptors were demonstrated, only basolateral membrane stimulation with EGF increased tyrosine kinase activity and enhanced uptake of [3H]thymidine. Continuous exposure to EGF during culture significantly increased monolayer DNA content. These data demonstrate that Caco-2 cell proliferation is driven solely by basolateral membrane EGF receptor, despite the presence of lesser amounts of this molecule on the apical surface. Differences between apical and basolateral membrane receptor expression are not the result of polarized secretion of TGF-alpha or other EGF receptor ligands.

UI	MeSH Term	Description	Entries
D007413	Intestinal Mucosa	Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.	Intestinal Epithelium,Intestinal Glands,Epithelium, Intestinal,Gland, Intestinal,Glands, Intestinal,Intestinal Gland,Mucosa, Intestinal
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004815	Epidermal Growth Factor	A 6-kDa polypeptide growth factor initially discovered in mouse submaxillary glands. Human epidermal growth factor was originally isolated from urine based on its ability to inhibit gastric secretion and called urogastrone. Epidermal growth factor exerts a wide variety of biological effects including the promotion of proliferation and differentiation of mesenchymal and EPITHELIAL CELLS. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form.	EGF,Epidermal Growth Factor-Urogastrone,Urogastrone,Human Urinary Gastric Inhibitor,beta-Urogastrone,Growth Factor, Epidermal,Growth Factor-Urogastrone, Epidermal,beta Urogastrone
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014018	Tissue Distribution	Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.	Distribution, Tissue,Distributions, Tissue,Tissue Distributions
D014407	Tumor Cells, Cultured	Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.	Cultured Tumor Cells,Neoplastic Cells, Cultured,Cultured Neoplastic Cells,Cell, Cultured Neoplastic,Cell, Cultured Tumor,Cells, Cultured Neoplastic,Cells, Cultured Tumor,Cultured Neoplastic Cell,Cultured Tumor Cell,Neoplastic Cell, Cultured,Tumor Cell, Cultured
D016211	Transforming Growth Factor alpha	An EPIDERMAL GROWTH FACTOR related protein that is found in a variety of tissues including EPITHELIUM, and maternal DECIDUA. It is synthesized as a transmembrane protein which can be cleaved to release a soluble active form which binds to the EGF RECEPTOR.	Epidermal Growth Factor-Related Transforming Growth Factor,TGF-alpha,TGFalpha,Epidermal Growth Factor Related Transforming Growth Factor
D016764	Cell Polarity	Orientation of intracellular structures especially with respect to the apical and basolateral domains of the plasma membrane. Polarized cells must direct proteins from the Golgi apparatus to the appropriate domain since tight junctions prevent proteins from diffusing between the two domains.	Cell Polarities,Polarities, Cell,Polarity, Cell