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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glucose starvation has been widely used to select differentiated subpopulations from the heterogenous human colon cancer cell line HT29. We observed that the important cell loss elicited by culturing these cells in glucose-free medium could be limited when type I collagen gel was used as substratum instead of conventional plastic support. We took advantage of this property to develop a new protocol, which combined glucose starvation and culture on collagen gels, for cloning HT29 cells. Using this procedure we have isolated four clones that were characterized on the basis of morphological (optical and transmission electron microscopy), electrophysiological (determination of transepithelial electrical parameters) and biochemical (detection of villin, sucrase-isomaltase and carcinoembryonic antigen) criteria. These four clones expressed different patterns of enterocytic differentiation regarding to these criteria. These results confirmed the heterogeneity of the HT29 cell line. One of these clones, HT29-A7, which displayed numerous intercellular cysts that disappeared at confluency, appears as a complementary model in the study of epithelial biogenesis.
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PMID:Combination of culture on collagen gels and glucose starvation for cloning human colon cancer cells. Obtention of clones exhibiting different patterns of enterocytic differentiation. 136 54

Cell lines were established from colon adenomas, including tubular and villous polyps, primary adenocarcinomas, and metastases arising in patients with colon adenocarcinomas. The protocol for cultivating these diverse tissues includes primary cultivation of tissue explants on a type I collagen gel followed by nonenzymatic subculture of the epithelial outgrowth. All early passages were accomplished using low subculture ratios. Cultured cells elaborate morphological structures which are similar to features present in the tissues from which they were cultivated. Specifically, all structural features of colon epithelial cells were identified, including junction formation, prominent microvilli, and mucin secretion, in several cell lines. Five cell lines cultured from colonic neoplasms at different stages of cancer progression were selected for detailed characterization. Cells grown from two tubular polyps had normal human karyotypes. Cells from a villous polyp and all adenocarcinomas were aneuploid with stable marker chromosomes. The established cell lines exhibit distinct phenotypes based on growth characteristics in vitro and in athymic mice; and it is suggested that these cell lines represent useful models for studying the evolution of colon cancer from a benign to an aggressive cell type.
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PMID:Cell culture of human colon adenomas and carcinomas. 356 99

Fermentation of dietary fiber within the colonic lumen yields short chain fatty acids (SCFA) such as butyrate, which may modulate colonic mucosal biology and inhibit the development of a malignant phenotype. However, different fibers yield varying proportions of various SCFA. We studied the effects of the three most common SCFA, acetate, butyrate, and propionate, on the proliferation, adhesion, and motility of the human intestinal Caco-2 cell line, as well as the effects of these SCFA on alkaline phosphatase and dipeptidyl dipeptidase specific activity (common laboratory markers of differentiation). In addition, we examined the modulation of c-myc protein and the tyrosine phosphorylation of cellular proteins by these SCFA in order to determine whether the variations in the potency of these three SCFA for phenotypic change extended to variations in effects on intracellular signaling and protooncogene expression. All three SCFA tended to slow proliferation, promote brush border enzyme activity, and inhibit both adhesion to and motility across a type I collagen matrix substrate. However, we observed substantial differences in the potency of these three SCFA with regard to these effects. In particular, butyrate was uniformly more potent than an equimolar concentration of acetate whereas equimolar propionate achieved comparable effects with regard to proliferation and brush border enzyme activity but was intermediate between butyrate and acetate with regard to modulation of cell-matrix interactions. Similarly, the SCFA downregulated c-myc protein levels and modulated the phosphorylation of several intracellular tyrosine phosphoproteins, but the effects of the three SCFA varied substantially for these parameters. These results suggest that the common short chain fatty acids are not equipotent in their effects on human Caco-2 colon cancer cell biology. Such differences in potency could contribute to the observed differences in effects of different dietary fibers in vivo.
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PMID:Differential modulation of human (Caco-2) colon cancer cell line phenotype by short chain fatty acids. 952 Oct 97

The present experiments examined the potential ability of parathyroid hormone-related protein (PTHrP) to influence growth of the human colon cancer cell HT-29 and the ability of the cell to adhere to several extracellular matrix (ECM) proteins found in normal tissues. Addition of PTHrP analogs, PTHrP (1-34), PTHrP (67-86), or PTHrP (107-139), to HT-29 cells in culture did not influence cell growth or the adhesion of the cells to wells coated with fibronectin, laminin, or collagen type I. Likewise, in HT-29 cells induced to overexpress PTHrP by stable transfection with PTHrP cDNA, compared to vector-transfected control HT-29 cells, no effect on cell growth occurred. However, in the transfected cells, the increased production of PTHrP significantly enhanced cell adhesion to type I collagen but not to fibronectin or laminin. The results raise the possibility that PTHrP might play a role in colon tumor invasion and metastasis by influencing cell adhesion to specific extracellular matrix proteins.
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PMID:Parathyroid hormone-related protein overexpression in the human colon cancer cell line HT-29 enhances adhesion of the cells to collagen type I. 1149 75

Epithelial-mesenchymal interactions play a pivotal role in colon cancer invasion and metastasis. We aimed at elucidating the impact of long-term cultivation on the phenotypic and functional characteristics of primary fibroblasts and their interaction with the human colon adenocarcinoma cell line LoVoC5. We used fibroblasts from human colon tumor tissue, normal human colon mucosa, rat normal colon and 2 rat colon-derived myofibroblast cell lines, MIC316 and MG. The following parameters were studied: cell shape and size, growth curve, intermediate filament expression and extracellular matrix synthesis. Coculture models with or without cell contacts were used to test the effects on LoVoC5 cell proliferation, spreading and adhesion. Irrespective of their origin, fibroblastic cells in primary cultures presented marked phenotypic and functional changes with time. Before passage 5, they presented as large, slow-growing cells expressing vimentin and alpha-smooth muscle actin; synthesizing laminin-1, fibronectin and collagens I and IV; and inducing LoVoC5 proliferation, spreading and adhesion. After passage 15, they presented as small, fast-growing cells inconstantly expressing alpha-smooth muscle actin and synthesizing mainly type I collagen. In coculture with or without cell contacts, they inhibited LoVoC5 proliferation and allowed only limited cell spreading and adhesion. Myofibroblastic cell lines presented as large, fast-growing cells expressing vimentin and alpha-smooth muscle actin and synthesizing mainly type I collagen. They had no significant effects on LoVoC5 proliferation, spreading and adhesion. Our results underline the importance of age-dependent variations in colon mesenchymal cells in culture and for the in vitro study of epithelial-mesenchymal interactions in colon cancer.
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PMID:Age-dependent variations of human and rat colon myofibroblasts in culture: Influence on their functional interactions with colon cancer cells. 1253 16

The effects of glycine-extended gastrin (G-Gly) on the invasion by colon cancer cells through stromal extracellular matrix and the role of metalloproteinases (MMPs) in this invasion were investigated. We found that 10(-9)-10(-6) M G-Gly significantly increased the invasiveness of 2 human colon cancer cell lines, LoVo and HT-29, both expressing the G-Gly-specific binding site but little gastrin/CCK-B receptor (gastrin receptor). LoVo cells expressed MMP-1, -2, -3 and -9. An amount of 10(-7) M G-Gly enhanced collagenase MMP-1 expression. Overexpression of enhanced green fluorescent protein (EGFP)-fused MMP-1 in LoVo cells, by cDNA transfection, enhanced invasiveness through type I collagen gel. Immunofluorescence study revealed that G-Gly increased the number of cytoplasmic vesicles containing MMP-1, some vesicles being released from the cells. The MMP-1 vesicles contained one of the ubiquitous coat proteins, Golgi-localized, gamma-adaptin ear-containing, ARF-binding proteins-2 (GGA-2). MMP-1 also colocalized with CD147 (EMMPRIN, an extracellular matrix metalloproteinase inducer in adjacent stromal cells). It was suggested that G-Gly increased the number of vesicles containing MMP-1 and that MMP-1 interacted with CD147 to increase invasion. G-Gly significantly enhanced the production of MMP-3, an activator of MMP-1 and -9, as well as gelatinase MMP-9 activity. The G-Gly-mediated MMP-9 increase was inhibited by treatment with anti-MMP-3 IgG and MMP-3 siRNA. Furthermore, G-Gly increased the proMMP-2 level, although no activated MMP-2 was found in conditioned medium in either the presence or the absence of G-Gly. By contrast, gastrin (10(-7) M) had no effect on the levels of these MMPs or the invasiveness of colon cancer cells in type I collagen gel and Matrigel. These effects of G-Gly on the activity and expression of MMPs and the invasiveness of colon cancer cells were inhibited by treating the cells with a broad-spectrum metalloproteinase inhibitor (CGS27023A) and nonselective gastrin/CCK receptor antagonists (proglumide and benzotript). But a gastrin/CCK-B receptor antagonist (YM022) did not inhibit the increased invasion by G-Gly. Together, these results demonstrate that G-Gly renders colon cancer cells more invasive by increasing MMP-1 and MMP-3 expressions via the putative G-Gly receptor and would thus be a good molecular target in a clinical setting.
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PMID:Glycine-extended gastrin induces matrix metalloproteinase-1- and -3-mediated invasion of human colon cancer cells through type I collagen gel and Matrigel. 1518 39

The ROCK-II isoform of Rho's downstream effector, Rho kinase, has been linked with greater invasion and metastasis in solid tumors. We have previously shown that ROCK-II is overexpressed at the advancing edge of colon cancers. The mechanism whereby ROCK-II contributes invasion, particularly in the setting of colon cancer, remains to be elucidated fully. To better understand its contribution, we evaluated ROCK-II expression in both non-malignant (NCM460 and IEC-6) and malignant (Caco-2 E, SW620, and HCT-116) intestinal epithelial cell lines grown in type I collagen scaffolds. Using multiphoton microscopy, we observed that ROCK-II localized to the actin cytoskeleton in non-malignant cells but localized to the cell periphery as focal collections with an absence of adjacent collagen in all colon cancer cell lines. By transmission electron microscopy, these collections corresponded with finger-like projections previously described as invadopodia. Immunogold staining with cortactin, matrix metalloprotease (MMP)-2, -9, and -13 confirmed that these were indeed invadopodia. To further link ROCK-II to colon cancer invasion, we treated non-malignant and malignant intestinal epithelial cell lines with ROCK-II siRNA and evaluated depth of invasion, proliferation, and MMP-2, -9, and -13 activities. The most striking effect was seen in the highly tumorigenic cell lines, SW620 and HCT-116, wherein ROCK-II knockdown resulted in a two-fold or more reduction in invasion. This reduction in invasion was not due to a decrease in cell proliferation, as a significant reduction in proliferation was only observed in the two non-malignant intestinal cell lines. Finally, both MMP-2 and -13 activities were significantly decreased in all colon cancer cell lines. Taken together, these data suggest for the first time that ROCK-II is a critical mediator of colon cancer cell invasion through its modulation of MMP-2 and -13 at the site of invadopodia but regulates proliferation in non-malignant intestinal cells.
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PMID:ROCK-II mediates colon cancer invasion via regulation of MMP-2 and MMP-13 at the site of invadopodia as revealed by multiphoton imaging. 1787 96

Periostin is a unique extracellular matrix protein, deposition of which is enhanced by mechanical stress and the tissue repair process. Its significance in normal and neoplastic colon has not been fully clarified yet. Using immunohistochemistry and immunoelectron microscopy with a highly specific monoclonal antibody, periostin deposition was observed in close proximity to pericryptal fibroblasts of colonic crypts. The pericryptal pattern of periostin deposition was decreased in adenoma and adenocarcinoma, preceding the decrease of the number of pericryptal fibroblasts. Periostin immunoreactivity appeared again at the invasive front of the carcinoma and increased along the appearance of cancer-associated fibroblasts. ISH showed periostin signals in cancer-associated fibroblasts but not in cancer cells. Ki-67-positive epithelial cells were significantly decreased in the colonic crypts of periostin-/- mice (approximately 0.6-fold) compared with periostin+/+ mice. In three-dimensional co-culture within type I collagen gel, both colony size and number of human colon cancer cell line HCT116 cells were significantly larger ( approximately 1.5-fold) when cultured with fibroblasts derived from periostin+/+ mice or periostin-transfected NIH3T3 cells than with those from periostin-/- mice or periostin-non-producing NIH3T3 cells, respectively. Periostin is secreted by pericryptal and cancer-associated fibroblasts in the colon, both of which support the growth of epithelial components.
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PMID:Periostin is expressed in pericryptal fibroblasts and cancer-associated fibroblasts in the colon. 1844 62

Macroporous hydrogels (MHs) hold great promise as scaffolds in tissue engineering and cell-based assays. In this study, the possibility of combination of three-dimensional (3D) cell culture with a miniaturized screening format was demonstrated on human colon cancer HCT116, human acute myeloid leukemia KG-1 cells, and embryonic fibroblasts cultured on MHs (12.5 mm x 7.1 mm I.D.) in a 96-minicolumn plate format. MHs were prepared by cryogelation technique and functionalized by coating with type I collagen and by copolymerization with agmatine-based mimetic of cell adhesive peptide RGD (abRGDm). Cancer cells formed multicellular aggregates while fibroblasts formed adhesions on abRGDm-containing and collagen-MHs but not on plain MHs, as was demonstrated by scanning electron microscopy. HCT116 and KG-1 cells grown as aggregates were more resistant to the treatment with cis-diaminedichloroplatinum (II) (cisplatin) and cytosine 1-beta-D-arabinofuranoside (Ara-C), respectively, during the first 18-24 h of incubation, than single cells grown on unmodified MH. HCT116 cells grown as 2D cultures in conventional 96-well tissue culture plates were 1.5- to 3.5-fold more sensitive to the treatment with 70 microM cisplatin than cells in 3D cultures in functionalized MHs. Further development of the described experimental system including matching of a specific cell type with appropriate extracellular matrix (ECM) components and 3D cocultures on ECM-modified MHs may provide a realistic in vitro experimental model for high-throughput toxicity tests.
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PMID:Biomimetic macroporous hydrogel scaffolds in a high-throughput screening format for cell-based assays. 1919 52

Crosstalk between integrins is involved in the regulation of various cell functions including cell migration. Here we identify the interplay between the integrins alphavbeta5/beta6 and alpha2beta1 during cell migration toward type I collagen. Human colon cancer cell lines HT29-D4 and SW480 were used as cell models. To improve our understanding of the consequences of alphavbeta5/beta6 function on alpha2beta1, we decreased the expression of alphav integrins by either siRNA or lysosomal targeting strategies or inhibited their function using, as antagonists, blocking antibodies or disintegrins. In all cases, we observed a greatly enhanced alpha2beta1 integrin-dependent cell migration associated with focal adhesion rearrangements and increased outside-in signaling as demonstrated by elevated phosphorylation of focal adhesion kinase and MAPKinase (ERK1 and ERK2). The alphavbeta5/beta6-dependent limitation of alpha2beta1 function could be overridden by TS2/16, an activating anti-beta1 antibody. Interestingly, compared to control cells, the pharmacological inhibition of PI3Kinase or the siRNA-mediated knockdown of AKT had little effect on the high alpha2beta1-mediated cell migration observed in the absence of alphav integrins or following activation of alpha2beta1 integrins by the TS2/16. These results suggest that integrins alphavbeta5/beta6 repress alpha2beta1 possibly by interfering with their activation process and thereby modify the cell signaling regulation of alpha2beta1-mediated migration.
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PMID:alphavbeta5/beta6 integrin suppression leads to a stimulation of alpha2beta1 dependent cell migration resistant to PI3K/Akt inhibition. 1932 97


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