Differential response to keratinocyte growth factor receptor and epidermal growth factor receptor ligands of proliferating and differentiating intestinal epithelial cells.
The expression of the keratinocyte growth factor receptor (KGFR) has been analyzed on intestinal epithelial Caco-2 cells upon confluence-induced spontaneous differentiation. Western blot and immunofluorescence analysis showed that the expression of functional KGFRs, differently from that of epidermal growth factor receptor (EGFR), was up-modulated in post-confluent differentiated cultures compared with the pre-confluent cells. Confocal microscopy and immunoelectron microscopy revealed that the up-regulated KGFRs displayed a basolateral polarized distribution on the cell surfaces in the monolayer. In vivo immunohistochemical analysis on normal human colon tissue sections showed that KGFRs, differently from EGFRs, were mostly distributed on the more differentiated cells located on the upper portion of the intestinal crypt. Bromodeoxyuridine incorporation assay and Ki67 labeling indicated that the differentiated cells were able to proliferate in response to the two ligands of KGFR, KGF and FGF-10, whereas they were not stimulated by the EGFR ligands TGFalpha and EGF. Western blot and quantitative immunofluorescence analysis of the expression of carcinoembryonic antigen (CEA) in post-confluent cells revealed that incubation with KGF induced an increase of cell differentiation. Taken together these results indicate that up-modulation of KGFR may be required to promote proliferation and differentiation in differentiating cells and that, among the cells componing the intestinal epithelial monolayer, the target cells for KGFR ligands appear to be different during differentiation from those responsive to EGFR ligands.
Visco
Vincenzo
V
Dipartimento di Medicina Sperimentale e Patologia, Università di Roma La Sapienza, Roma, Italy.
Belleudi
Francesca
F
Marchese
Cinzia
C
Leone
Laura
L
Aimati
Laura
L
Cardinali
Giorgia
G
Kovacs
Daniela
D
Frati
Luigi
L
Torrisi
Maria Rosaria
MR
D000911:Antibodies, Monoclonal / Q000378:metabolism; D015153:Blotting, Western; D018938:Caco-2 Cells; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D045744:Cell Line, Tumor; D016764:Cell Polarity; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D066246:ErbB Receptors / Q000378:metabolism* / Q000648:ultrastructure; D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D019084:Fluorescent Antibody Technique, Indirect; D006133:Growth Substances / Q000494:pharmacology; D019073:HT29 Cells; D006801:Humans; D007422:Intestines / Q000166:cytology; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D019394:Ki-67 Antigen / Q000378:metabolism; D008024:Ligands; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D008954:Models, Biological; D051497:Receptor, Fibroblast Growth Factor, Type 2; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism* / Q000648:ultrastructure; D015854:Up-Regulation / Q000187:drug effects
D000911:Antibodies, Monoclonal; D002272:Carcinoembryonic Antigen; C496463:FGF10 protein, human; D051526:Fibroblast Growth Factor 10; D006133:Growth Substances; D019394:Ki-67 Antigen; D008024:Ligands; D017468:Receptors, Fibroblast Growth Factor; D005346:Fibroblast Growth Factors; D066246:ErbB Receptors; D051497:Receptor, Fibroblast Growth Factor, Type 2; C065104:keratinocyte growth factor receptor