Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Patient J. B. with metastatic carcinoma of the colon excreted 0.5 to 1.0 g protein daily, about one-third of which was in Molecular Weight Class 30,000 to 60,000. The major component of this class was isolated by gel filtration and ion-exchange chromatography. The purified protein, labeled JBB5, contained about 11% sialic acid, 8% hexose, and 4% hexosamine. Its molecular weight was between 51,000 and 59,000. It did not react detectably with antisera to any of the recognized normal human plasma proteins. A specific antiserum to JBB5 was raised in the rabbit. Urine from 4% of subjects with nonneoplastic illnesses reacted in double immunodiffusion with anti-JBB5. Thirty-three % positive reactions were obtained with urines from patients with advanced neoplastic disease, the percentage varying from 64% in metastatic cancer of the pancreas to 15% in chronic lymphocytic leukemia.
 ...
PMID:Isolation and characterization of the glycoprotein (JBB5) in the urine of a patient with carcinoma of the colon. 40 9

Serum enzymes have not proved useful in evaluation of patients with early colon cancer, but certain enzymes such as transpeptidase, phosphohexone isosomerase, or 5'-nucleotidase have been of assistance in following the course of the disease, particularly in patients with metastatic spread to the liver. Attempts have been made to improve the utility of enzyme analysis in colon cancer by examination of enzyme patterns in colon biopsy specimens, feces, and colon washings. These studies, which will be summarized, are of importance in the possible development of diagnostic tools and as probes in the understanding of the etiology of colon cancer. The technical problems in carrying out these assays in humans, as well as the significance of the activity of aryl sulfatase, beta-glucuronidase, beta-glucosidase, lactic dehydrogenase, glucose-6-p-osphate dehydrogenase, and other enzymes will be considered.
 ...
PMID:Enzymes in colon cancer. General information. 76 57

Twenty-three strains of intestinal anaerobes obtained from two laboratories were examined for indole production from tryptophan. Among the 23 isolates tested, three of Bacteroides fragilis thetaiotaomicron and one Citrobacter sp. were indole positive. The tryptophanase of the indole-positive strains of intestinal anaerobes was inducible by tryptophan and was susceptible to glucose repression. The products of tryptophanase activity were formed in stoichiometric amounts by dialyzed, freshly prepared extracts. The tryptophan concentration and tryptophanase activity in feces from rats on an all-meat diet were significantly higher than those in feces from rats on a normal diet. The results indicated that the higher tryptophanase activity in the feces of rats fed an all-meat diet is due to the inducibility of this enzyme by tryptophan and is not due to any inhibitor in the feces of rats on a normal diet. The results also suggested that a population with a diet rich in meat has a greater chance for exposure to possible carcinogens such as indole and other tryptophan metabolites. This agrees with the hypothesis, based on epidemiologic data, that a high intake of meat may be related to the development of colon cancer in man.
 ...
PMID:Tryptophanase of fecal flora as a possible factor in the etiology of colon cancer. 112 36

The goal of this investigation was to identify the metabolic abnormalities in a group of colon cancer patients before and during 5-fluorouracil chemotherapy. Twenty-two colon cancer patients were prospectively enrolled into a Clinical Research Center for measurement of counter regulatory hormones, fasting hepatic glucose production (HGP), intravenous glucose tolerance test, plasma leucine appearance (LA), and leucine oxidation (LO). Both the cancer group and the normal volunteers were matched for nutrition status (109 +/- 5% of ideal body weight vs 104 +/- 4%, mean +/- SEM, respectively) and history of weight loss (6.3 +/- 2.6 kg vs 4.4 +/- 4.8). Plasma growth hormone was significantly elevated in the colon cancer patients (3.22 +/- 0.62 ng/mL vs 0.73 +/- 0.18, p < .05) despite the fact that insulin-like growth factor-1 levels were not different. Plasma glucose, insulin, cortisol, glucagon, epinephrine, and norepinephrine levels were not significantly different than those of the normal volunteers. Fasting HGP rates were slightly but not significantly elevated in the group of colon cancer patients compared with the normal volunteers (2.09 +/- 0.11 mg/kg per minute vs 1.79 +/- 0.10, p = .10). Plasma LA was not significantly elevated in the colon cancer group (63.3 +/- 3.0 mumol/kg per hour vs 57.7 +/- 4.2; p = .25). Five days of continuous 5-fluorouracil chemotherapy was associated with a significant elevation in both the fasting glucose level (97 +/- 3 mg/dL vs 106 +/- 5, p < .05), and HGP (2.09 +/- 0.11 mg/kg per minute vs 2.27 +/- 0.10; p < .05).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Metabolic response to chemotherapy in colon cancer patients. 128 27

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.
 ...
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

The HT-29 human adenocarcinoma cell line has been used extensively in the study of colonic cell differentiation and colon cancer. We report here that substitution of glucose with trehalose (alpha-D-glucopyranosyl-alpha-D-glucopyranoside) depresses growth and promotes mucin-producing, goblet-like maturation of HT-29. An initial characterization of this process was made by analyzing several cDNA clones whose RNA templates were differentially expressed at elevated levels in cells grown in trehalose-containing medium. Seven of the 9 clones examined corresponded to 6 mitochondrial genes whose expression levels, relative to those from glucose-grown cells, ranged from approximately 3-fold for 16S rRNA to 8-23-fold for NADH dehydrogenase subunit 4. On the other hand, levels of mitochondrial DNA copy, measured by using NADH dehydrogenase subunit 4 cDNA as probe, were shown to be unaffected by trehalose treatment. Elevation of cellular NADH dehydrogenase subunit 4 RNA in HT-29 cultures grown in medium containing different components (sodium butyrate, galactose, no-sugar, glucose, cellobiose) generally correlated with depressed growth levels and specifically with increased numbers of mucin-producing cells present. Like butyrate, the sugar, trehalose, is an effective inducer of HT-29 differentiation, and may prove useful as a dietary therapeutic, and as a probe for elucidating mitochondrial involvement in colonic cell differentiation and transformation.
 ...
PMID:Differentiation of HT-29 human colonic adenocarcinoma cells correlates with increased expression of mitochondrial RNA: effects of trehalose on cell growth and maturation. 137 97

In this paper we compared several lipid characteristics of the homogenate and the corresponding plasma membrane in undifferentiated and differentiated HT29 human colon cancer cells, using normal human colonic cells as a reference. Electron microscopy showed that HT29 cells were morphologically undifferentiated when cultured in the presence of either glucose or inosine without glucose at early confluency. On the contrary, HT29 cells cultured at late confluency in a glucose-free medium containing inosine or grown in nude mice exhibited an enterocytic differentiation with the presence of tight junctions and an apical brush border. The cell homogenate and the plasma membrane were prepared from each cell type. The study of specific marker enzymes showed the same degree of purity in all plasma membranes, with a highly marked increase of brush border-associated hydrolases (N-aminopeptidase and alkaline phosphatase) only in the organelles isolated from differentiated HT29 and colonic cells. Respective similar increases in the amount of free cholesterol and phospholipid and in the free cholesterol:phospholipid molar ratio were found in the plasma membrane as compared with the homogenate in all HT29 cell types. This ratio, due to an increased phospholipid content in both homogenate and plasma membrane, was lowered in colonic cells. No differences in the phospholipid profile were found between the homogenates of all cell types and the plasma membrane of undifferentiated HT29 cells, with the exception of a decrease of cardiolipin in this organelle. On the contrary, the plasma membrane phospholipid composition was different from that of the corresponding homogenate in differentiated HT29 and colonic cells. The most striking changes were a highly increased sphingomyelin amount and concomitant decreases in phosphatidylethanolamine, phosphatidylserine, and cardiolipin. Moreover, differences in the percentage of phosphatidylcholine plus sphingomyelin as well as in phosphatidylcholine:sphingomyelin, phosphatidylethanolamine, and/or phosphatidylcholine molar ratios were also found. The monounsaturated:polyunsaturated fatty acid ratio in phosphatidylethanolamine was similar in differentiated HT29 and colonic cells and lower than in undifferentiated HT29 cells. A decrease in this latter ratio in phosphatidylcholine was also observed in colonic cells and HT29 cells grown in nude mice. These changes were essentially due to opposite variations in the percentage of palmitoleic acid and those of linoleic and/or arachidonic acids in both phospholipids. Thus, these data indicate that undifferentiated HT29 cells were characterized by the absence of a specific phospholipid composition in their plasma membrane, which is suggested to be related to altered phospholipid sorting. The plasma membrane phospholipid profile reversed essentially to the normal pattern when HT29 cells recovered the ability to differentiate.
 ...
PMID:Differences in lipid characteristics of undifferentiated and enterocytic-differentiated HT29 human colonic cells. 167 56

The serum-free medium conditioned by the human colon cancer cell line HT-29 contains insulin-like growth factors (IGF) that are entirely complexed to binding proteins (IGF-BP). Gel filtration in acid conditions of the cell-conditioned medium permits separation of IGF-BP from two molecular forms of IGF of 15,000 and 7,500 Mr. As determined by ligand blotting, IGF-BP are heterogeneous and constituted of three molecular forms of 31,000, 28,000, and 26,000 Mr. Using IGF-I and IGF-II radioreceptor assays, IGF-I radioimmunoassay (RIA), and competitive protein-binding assay specific for IGF-II, it is shown that the IGF-type eluting in 15 K and 7.5 K position from gel filtration is restricted to IGF-II. Its concentration is approximately 6 ng/10(6) HT-29 cells with 60% present as a high-molecular-weight form of IGF-II. This large 15 K IGF molecule is devoided of any IGF-binding activity and might represent incomplete processing of pro-IGF-II peptide. By contrast, the level of IGF-I detected by RIA is barely measurable and considered negligible (0.57 pg/10(6) HT-29 cells). Although these IGF-II-like peptides exhibit a growth-promoting activity on FR3T3 fibroblasts, they cannot stimulate, as recombinant IGF-I or IGF-II, 3H-thymidine incorporation into DNA of HT-29 cells, whatever the experimental conditions used. Finally, we have shown that IGF binding is restricted predominantly to the basolateral domain of the cell membrane by using HT-29-D4 clonal cells, derived from the parental HT-29 cell line, maintained in a differentiated state by culture in a medium in which glucose is replaced by galactose.
 ...
PMID:Production of insulin-like growth factor II (IGF-II) and different forms of IGF-binding proteins by HT-29 human colon carcinoma cell line. 169 80

The gastrointestinal tract is considered to be a major route of infection for the human immunodeficiency virus (HIV). To understand the interaction of HIV with epithelial cells of the intestinal mucosa, we have studied the infection of a human colon cancer cell clone HT-29-D4. The enterocyte-like differentiation of this clone can be modulated in vitro according to the concentration of glucose. We show that: (i) undifferentiated HT-29-D4 cells can be infected by HIV types 1 and 2 (HIV-1 and HIV-2) strains with no subsequent effect on cell growth; (ii) undifferentiated HT-29-D4 cells express a CD4-related antigen bearing epitopes of the immunoglobulin-like variable (V) region domains V1 and V2 of CD4 but lacking the epitope known to be involved in HIV envelope recognition; (iii) differentiated HT-29-D4 cells can be infected by HIV after an interaction with either the apical brush border membrane (luminal side) or the basolateral side (serosal side); (iv) the CD4-like molecule is restricted to the basolateral domain of differentiated cells; and (v) the infection is not inhibited by anti-CD4 monoclonal antibodies (mAbs) OKT4, OKT4A, Leu-3a, Bl4, 13-B-8-2, S-T4 or S-T40. We conclude that epithelial intestinal cells may represent a major site of entry for HIV. Infection of these epithelial cells may occur via the basolateral membrane by HIV-bearing lymphocytes or macrophages of the lamina propria and via the apical membrane by HIV present in the bowel lumen. This infection may remain silent for up to 9 months, and the virus can be rescued by cocultivation with lymphoid cells. These data may give an explanation for the long latent seronegative state that may occur in a HIV-infected individual.
 ...
PMID:Human immunodeficiency virus can infect the apical and basolateral surfaces of human colonic epithelial cells. 171 4

Suramin is an anti-cancer drug which induces the differentiation of the human colon cancer clone HT29-D4. Yet chronic suramin treatment of these cells eventually leads to a marked disturbance of the lysosomal system, which consists in an accumulation of hypertrophied autophagic vacuoles and the occurrence of lamellated inclusion bodies. We report here the effect of a prime treatment of HT29-D4 cells with suramin during various periods of time, followed by the removal of the drug and a subsequent culture in suramin-free medium. A prime treatment of cells in the presence of the drug for 2 days or 4 days was found ineffective to induce the organization of cells into polarized monolayers. On the contrary, a prime treatment of cells for 5 days is sufficient to allow the cellular organization to proceed normally toward a fully polarized monolayer, without any lysosomal damage. The cells did not require the continuous presence of suramin to develop an electrical resistance and a transepithelial potential difference. Moreover the basolateral localization of HLA class I molecules was achieved 9 days after the removal of the drug from the culture medium. Finally prime treatment of cells in the presence of suramin for times longer than 5 days induced the morphological, biochemical, and electrophysiological differentiation of HT29-D4 cells. However, in this case, severe lysosomal disturbances were constantly observed. These data demonstrate that the impaired lysosomal system is a post-differentiation event due to prolonged exposure of the cells to suramin. A metabolic analysis of HT29-D4 cells primed for various times with the drug showed that differentiated cells have a reduced glycolytic activity and this suggests an action of suramin at the level of autocrine growth factors which are known to regulate glucose uptake and degradation.
 ...
PMID:Short-term suramin treatment followed by the removal of the drug induces terminal differentiation of HT29-D4 cells. 173 Jul 80


1 2 3 4 5 6 7 8 9 10 Next >>