title: Gene expression in TGFbeta-induced epithelial cell differentiation in a three-dimensional intestinal epithelial cell differentiation model.
abstract: BACKGROUND
  The TGFbeta1-induced signal transduction processes involved in growth and differentiation are only partly known. The three-dimensional epithelial differentiation model, in which T84 epithelial cells are induced to differentiate either with TGFbeta1 or IMR-90 mesenchymal cell-secreted soluble factors, is previously shown to model epithelial cell differentiation seen in intestine. That model has not been used for large scale gene expression studies, such as microarray method. Therefore the gene expression changes were studied in undifferentiated and differentiated three-dimensional T84 cultures with cDNA microarray method in order to study the molecular changes and find new players in epithelial cell differentiation.
  
  
  RESULTS
  The expression of 372 genes out of 5188 arrayed sequences was significantly altered, and 47 of them were altered by both mediators. The data were validated and the altered genes are presented in ontology classes. For the genes tested the expressions in protein level were in accordance with the mRNA results. We also found 194 genes with no known function to be potentially important in epithelial cell differentiation. The mRNA expression changes induced by TGFbeta1 were bigger than changes induced by soluble factors secreted by IMR-90 mesenchymal cells. The gene expression data was depicted in already known signaling pathway routes.
  
  
  CONCLUSIONS
  Our results reveal potential new signaling pathways and several new genes affected by TGFbeta in epithelial cell differentiation. The differentiation induced by TGFbeta1 appears to be more potent than the differentiation induced by mesenchymal cells. This study indicates that our cell culture model is a suitable tool in studying regulatory mechanisms during epithelial cell differentiation in intestine. Furthermore the present results indicate that our model is a good tool for finding new players acting in the differentiation of epithelial cells.
authors.affiliation: Paediatric Research Centre, Tampere University and Tampere University Hospital, Tampere, Finland. lokaju@uta.fi <lokaju@uta.fi>
authors.forename: Kati M
authors.initials: KM
authors.lastname: Juuti-Uusitalo
authors.forename: Katri
authors.initials: K
authors.lastname: Kaukinen
authors.forename: Markku
authors.initials: M
authors.lastname: Mäki
authors.forename: Jarno
authors.initials: J
authors.lastname: Tuimala
authors.forename: Heikki
authors.initials: H
authors.lastname: Kainulainen
mesh_terms: D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics*; D045744:Cell Line, Tumor; D003106:Colon / Q000166:cytology* / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005347:Fibroblasts / Q000737:chemistry; D005786:Gene Expression Regulation; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology* / Q000378:metabolism*; D008648:Mesoderm / Q000166:cytology; D020411:Oligonucleotide Array Sequence Analysis; D015398:Signal Transduction; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
chemical_list: D053773:Transforming Growth Factor beta1