In normal colon epithelium, cell proliferation is followed by cell differentiation. The purpose of this work was to investigate, in the HT29-D4 colon adenocarcinoma cell line, the occurrence of a temporal sequence of changes in cell proliferation and differentiation, the role of autocrine EGF family ligands and to determine which transduction pathway(s) are involved in these processes. In a medium lacking both growth factor and serum, HT29-D4 cells secreted amphiregulin (AR), which was shown to be strongly involved in cell adhesion, growth and differentiation.
View Article and Find Full Text PDFGastroenterology
December 1999
Background & Aims: Homeobox genes are involved in establishing and maintaining differentiated patterns in adult tissues. Cdx1 might carry out that function in the intestinal epithelium because its expression is specific to that tissue and increases during development.
Methods: Cdx1 expression was induced in IEC-6 intestinal epithelial cells by stable transfection, and subsequent changes in cell growth, resistance to apoptosis, migration, and differentiation were monitored.
When cultured in high glucose containing medium, the human colon carcinoma cell line HT29-D4 and a clone derived by transfection with the MDR1 cDNA (MDR31) form multilayers of unorganized cells which are not polarized and are linked by desmosomes. Within these multilayers appear spontaneously large multicellular follicle-like-structures (FLS) where polarized cells linked by tight junctional complexes surround a lumen. Electron microscopy showed that some FLS display well developed brush borders with densely packed microvilli.
View Article and Find Full Text PDFThe aim of this work was to show in serum-free medium a convergent effect of physiological factors and extracellular matrix proteins on the differentiation process of enterocytes by taking as a model the HT29-D4 clone that has the feature of differentiating when subcultured in fetal bovine serum glucose-free medium. We show that triiodothyronine (T3) as well as insulin promotes limited cell growth and differentiation, whereas fibronectin or bovine serum albumin (BSA) induces cell growth and a low level of differentiation. However, insulin, T3, fibronectin, and BSA together with epidermal growth factor and transferrin promoted satisfactory growth and enterocyte morphology with epithelial electrophysiological properties in HT29-D4 cells.
View Article and Find Full Text PDFTaxoids (paclitaxel, Taxol and docetaxel, Taxotere), drugs which stabilize microtubules, demonstrate marked activity against ovarian, brain and lung cancer. We investigated, on the human colon adenocarcinoma HT29-D4 cell line, firstly the effects of taxoids in function of the differentiation state and secondly the effects of a low dose of paclitaxel on the differentiation process. The cellular parameters studied were microtubular network, cell cycle and cell tubulin content.
View Article and Find Full Text PDFIn Vitro Cell Dev Biol Anim
August 1994
In Vitro Cell Dev Biol Anim
August 1994
HT29-D4 human colon-carcinoma cells have been shown to secrete insulin-like growth factor (IGF)-II and to simultaneously express type-I IGF receptors. However, the sequestration of IGF-II by several molecular forms of IGF-binding proteins (IGFBP) in the culture medium prevents the establishment of an operative IGF-II autocrine loop. IGFBPs secreted by HT29-D4 cells (HT29-D4 IGFBP) comprise isoforms of IGFBP-4 (25, 27 and 30 kDa) and 2 unidentified forms (34.
View Article and Find Full Text PDFSuramin, a drug that binds to several types of growth factors, has been previously shown to induce the enterocyte-like differentiation of HT29-D4 human colonic adenocarcinoma cells, suggesting that growth factors are involved in such a process. Undifferentiated HT29-D4 cells release insulin-like growth factor II (IGF-II) into the culture medium that is totally complexed to heterogeneous IGF binding proteins (IGFBP) expressing high affinities for this growth factor (Kda = 0.02 nM and Kdb = 1.
View Article and Find Full Text PDFConfluent monolayers of intestinal cell lines are useful models for studies of intestinal epithelial structure and function. Three cell lines have retained morphological and functional properties of intestinal epithelial cells compatible with such studies: Caco-2, T84 and HT29. However, the requirement of fetal bovine serum for the culture of these cells does not facilitate the design of experiments dealing with growth factors or hormonal regulation.
View Article and Find Full Text PDFSuramin, a drug currently used for advanced malignancy, induces the differentiation of the human colonic adenocarcinoma cell clone HT29-D4 and this process is correlated with a decreased glycolytic activity. We investigated the effects of suramin on HT29-D4 cells in the presence of various glucose concentrations. The main result of this study is that suramin has only an effect on HT29-D4 cell growth and differentiation when the concentration of glucose is above 10 mM.
View Article and Find Full Text PDFThe clonal cell line HT29-D4 is able to differentiate by two different ways: i) by replacing glucose by galactose in the culture medium; ii) by addition of suramin (a drug known to interfere with the growth promoting activity of growth factors) in the medium. In both cases the transition in the organization of the cell monolayer occurred without cell loss. The two ways (i.
View Article and Find Full Text PDFSuramin, a drug used in the treatment of trypanosomiasis and onchocerciasis inhibits growth factor-induced mitogenesis. In the present report, we show that suramin inhibits the growth of human colic adenocarcinoma cells HT29-D4 and rapidly induces their differentiation into enterocyte-like cells. As soon as 6 days after the addition of suramin (100 micrograms/ml) in the culture medium, the cells form a polarized monolayer of regular columnar cells with occluding junctions delimiting two distinct membrane domains (apical and basolateral) and an apical brush-border expressing alkaline phosphatase and sucrase-isomaltase.
View Article and Find Full Text PDFIn the present study, changes in thyroid follicular cell volume and its regulation have been investigated during the early involution of a hyperplastic goitre. Male Wistar rats were administered an iodine deficient diet for 6 months with propylthiouracil (PTU, 0.15%) during the last two months.
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