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

A randomized study was performed in advanced cancer to test the effectiveness of total parenteral nutrition (TPN) in maintaining and improving nutrition, to examine the effects of TPN on tumor growth, and to determine if TPN altered chemotherapy response rates, treatment tolerance, and survival. Forty-five patients on identical chemotherapy were randomized to TPN versus ad libitum feeding. TPN was well tolerated. No clinical or tumor marker evidence suggesting neoplastic growth stimulation was obtained. Chemotherapy-related complications and chemotherapy responses did not differ between the two groups. TPN had little effect on performance status. TPN patients gained an average of 2.8 kg before chemotherapy, but triceps skinfold and mid-arm muscle area did not change significantly during TPN. Survival did not improve with TPN. We conclude that current techniques of TPN are of limited benefit in advanced colon cancer. A small subset of patients with short-gut malabsorption may be helped. Further study is needed to determine the mechanisms of cancer undernutrition and to refine nutritional supplementation techniques on the basis of these mechanisms.
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PMID:Total parenteral nutrition as an adjunct to chemotherapy of metastatic colorectal cancer. 680 21

The occurrence of CEA was extensively adsorbed to eliminate cross-reactions with CEA-related antigens. After the first trimester of pregnancy CEA was found throughout the gastrointestinal tract by both techniques, whereas the other fetal tissues and fetal serum did not contain detectable amounts of CEA. The CEA-level of all 69 sera of pregnant women was below 2.5 ng/ml. The excretory nature of CEA was suggested by the localization of CEA in the luminal border of the alimentary tract and by the finding that the CEA concentration in the content of fetal gastrointestinal canal was higher than in the surrounding tissue. Gel filtration on Sepharose 4B showed that molecular weight of CEA immunoreactive material of the fetal gut was similar to that of CEA purified from colon cancer, but a minor component with a higher molecular weight was eluted in the void volume. When tested in radioimmunoassay, the CEA immunoreactive material in both peaks gave an inhibition curve parallel to that of purified CEA.
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PMID:Carcinoembryonic antigen in fetal tissues and in material serum. 699 Jun 84

Populations consuming diets high in fat and cholesterol exhibit a greater incidence of colon cancer than those consuming less fat and cholesterol. Lowering elevated serum cholesterol levels experimentally or clinically is associated with increased large-bowel tumorigenesis. Thus, cholesterol lost to the gut, either dietary or endogenously synthesized, appears to have a role in large-bowel cancer. Whether the effect(s) is mediated by increases in fecal bile acid excretion or some other mechanism is not clear.
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PMID:Cholesterol excretion and colon cancer. 726 Sep 37

Ras regulates novel patterns of gene expression and the differentiation of various eukaryotic cell types. Stable transfection of Ha-ras into the human colon cancer line CaCo2 results in the morphologic differentiation to a small bowel phenotype. The purpose of our study was to determine whether the Ras regulatory pathway plays a role in the expression of the neurotensin gene (NT/N), a terminally differentiated endocrine product specifically localized in the gastrointestinal tract to the adult small bowel. We found that CaCo2-ras cells, but not parental CaCo2, express high levels of the human NT/N gene and, moreover, that this increase in gene expression is regulated at the level of transcription. Transfection experiments using NT/N-CAT mutation constructs identify the proximal 200 bp of NT/N flanking sequence as sufficient for maximal Ras-mediated NT/N reporter gene induction. Furthermore, a proximal AP-1/CRE motif is crucial for this Ras-mediated NT/N activation. Wild-type Ha-ras induces NT/N gene expression, albeit at lower levels than activated Ras; a dominant-negative Raf blocks this NT/N induction, suggesting that Raf lies down-stream of Ras in this pathway. In addition, postconfluent cultures of CaCo2 cells, which are differentiated to a small bowel phenotype, express the NT/N gene by 6 d after reaching confluency; this increase of NT/N expression is associated with concomitant increases of cellular p21ras protein. We conclude that Ras (both wild-type and activated) enhances expression of the NT/N gene in the gut-derived CaCo2 cell line, suggesting an important role for the Ras signaling pathway in NT/N gene transcription. Our results underscore the possibility that tissue-specific genes (such as NT/N) expressed in distinct subpopulations of the gut may be subject to Ras regulation. Finally, we speculate that the NT/N gene and the CaCo2 and CaCo2-ras cell systems will provide unique models to further define the cellular mechanisms leading to mammalian intestinal differentiation.
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PMID:The neurotensin gene is a downstream target for Ras activation. 776 22

Controversy exists about the relationship between hypergastrinemia and colon cancer. Conflicting lines of evidence may be interpreted to support a variety of views regarding the link between the two. Although some experimental and clinical data suggest a strong correlation, other studies refute this. It is likely that the actual situation lies between these two viewpoints; the complex nature of the relationship between carcinogenesis and putative gut hormones makes a definitive answer unlikely. Nevertheless, a critical reading of the recent literature suggests that hypergastrinemia does not play a direct role in colorectal carcinogenesis. Certain subgroups of patients with elevated serum gastrin levels and tumors that possess gastrin receptors may have accelerated tumor growth. Further study of this issue is warranted to elucidate the role of the gastrointestinal hormonal milieu in colorectal neoplasia.
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PMID:Gastrin and colon cancer. Clarifying the controversy. 803 12

The associations between alcohol and colon and rectal cancers were examined in the Iowa Women's Health Study. In January 1986, 41 837 postmenopausal women, aged 55-69, completed a questionnaire including usual alcohol intake and other information. Through December 1990, 237 incident colon and 75 rectal cancer cases occurred. Mantel-Haenszel age-adjusted relative risks (RR) and 95% confidence intervals (CI) for consumers of < 4.0 and > or = 4.0 g of alcohol per day compared to abstainers were 1.07 (0.61-1.89) and 1.27 (0.72-2.24) (P for trend = 0.46) for rectal cancer. Alcohol intake was inversely associated with distal colon cancer (RR for < 4.0 and > or = 4.0 g of alcohol per day were 0.64 and 0.69 respectively, P for trend = 0.04), which was specific to wine; however, no association was observed with proximal colon cancer (P for trend = 0.94). This is the only report of an inverse association between alcohol and colon cancer in women. Because gut physiology and alcohol metabolism differ between men and women, more research on the association between alcohol and colon cancer in women only, is warranted.
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PMID:Alcohol consumption and colon and rectal cancer in postmenopausal women. 819 24

Hepatocyte growth factor/scatter factor (HGF/SF) is a protein growth factor whose pleiotropic effects on epithelial cells include the stimulation of motility, mitosis and tubulogenesis. These responses are mediated by the cell surface tyrosine kinase receptor c-met. Because both the cytokine and receptor are found in the gastrointestinal tract, we have studied the effects of HGF/SF on transformed gut epithelial cells which express c-met. Here we describe the response of a new transformed human jejunal epithelioid cell line (HIE-7) to HGF/SF. Morphologically HIE-7 cells are immature. Their epithelial lineage was confirmed by reactivity with the epithelial specific antibodies AE1/AE3, Cam 5.2, Ber-EP4 and anti-EMA and is consistent with their expression of c-met mRNA and protein. In addition, electron microscopic analysis revealed the presence of primitive junctions and rudimentary microvilli, but features of polarization were absent. When grown on reconstituted basement membranes, HIE-7 cells formed closely associated multicellular cord-like structures adjacent to acellular spaces. However, the cells did not mature structurally, form lumen-like structures or express disaccharidase mRNA, even in the presence of recombinant HGF (rHGF). On the other hand, rHGF induced HIE-7 cells to scatter and stimulated their rapid migration in a modified wound assay. To determine whether the mitogenic effect caused by rHGF is associated with HIE-7 cell invasiveness across reconstituted basement membranes, a Boyden chamber chemoinvasion assay was performed. rHGF stimulated a 10-fold increase in the number of HIE-7 cells that crossed the basement membrane barrier, while only stimulating a small increase in chemotaxis across a collagen IV matrix, suggesting that the cytokine activates matrix penetration by these cells. rHGF also stimulated the invasion of basement membranes by an undifferentiated rat intestinal cell line (IEC-6) and by two human colon cancer cell lines which are poorly differentiated (DLD-1 and SW 948). In contrast, two moderately well differentiated colon cancer cell lines (Caco-2 and HT-29) did not manifest an invasive response when exposed to rHGF. These results suggest that HGF/SF may play a significant role in the invasive behavior of anaplastic and poorly differentiated gut epithelial tumors.
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PMID:Hepatocyte growth factor stimulates invasion across reconstituted basement membranes by a new human small intestinal cell line. 830 28

Alcohol ingested orally is transported to the colon by blood circulation, and after the distribution phase, intracolonic ethanol levels are equal to those in the blood. Recent studies in our laboratory suggest that in the large bowel ethanol is oxidized by a bacteriocolonic pathway. In this pathway intracolonic ethanol is at first oxidized by bacterial alcohol dehydrogenase to acetaldehyde. Then acetaldehyde is oxidized either by colonic mucosal or bacterial aldehyde dehydrogenase to acetate. Part of intracolonic acetaldehyde may also be absorbed to portal vein and be metabolized in the liver. The bacteriocolonic pathway offers a new explanation for the disappearance of a part of ethanol calories. Due to the low aldehyde dehydrogenase activity of colonic mucosa, acetaldehyde accumulates in the colon. Accordingly during ethanol oxidation highest acetaldehyde levels of the body are found in the colon and not in the liver. High intracolonic acetaldehyde may contribute to the pathogenesis of alcohol-induced diarrhoea. Because acetaldehyde is a carcinogen in experimental animals, it may also contribute to the increased risk of colon polyps and colon cancer, which have been found to be associated with heavy alcohol consumption. Intracolonic acetaldehyde may also be an important determinant of the blood acetaldehyde level and a possible hepatotoxin. In addition to acetaldehyde, gut-derived endotoxin is another potential candidate in the pathogenesis of alcohol-related liver injury. Experimental alcoholic liver injury has recently been prevented by antibiotics, and this effect was related to the prevention of endotoxin-induced activation of Kupffer's cells.
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PMID:Bacteriocolonic pathway for ethanol oxidation: characteristics and implications. 881 Nov 62

The present study was designed to test the hypothesis that increasing short-chain fatty acid (SCFA) production in the large bowel increases gut epithelial proliferation rate (EPR). Two experiments were carried out in which rats were fed on bread (wholemeal or white)-based diets containing graded amounts of cooked haricot (Phaseolus vulgaris) beans; the latter are a rich source of fermentable carbohydrates. Consumption of beans was associated with several-fold increases in SCFA production with the greatest relative increase being for butyrate. Despite the very large increase in SCFA production, there was no evidence that this had any effect on EPR in the duodenum. Where the basal diet contained wholemeal bread (Expt 1) there was no effect of enhanced SCFA supply on EPR in either the caecum or colon, but with the white bread-based diet (Expt 2) adding beans produced increments in both SCFA supply and EPR in the caecum. Evidence that SCFA are responsible for enhanced EPR above normal levels is not convincing. In those instances where enhanced SCFA supply is associated with increased EPR, the increase may be (1) from a hypoproliferative state towards normal, (2) a transient phenomenon accompanying tissue hypertrophy or (3) a homeostatic response to increased cell loss by cell sloughing or apoptosis. It is not likely that there is any direct link with risk of colon cancer.
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PMID:Tissue hypertrophy and epithelial proliferation rate in the gut of rats fed on bread and haricot beans (Phaseolus vulgaris). 881 1

Probiotic bacteria are used to treat disturbed intestinal microflora and increased gut permeability which are characteristic to many intestinal disorders. Examples include children with acute rotavirus diarrhoea, subjects with food allergy, subjects with colonic disorders and patients undergoing pelvic radiotherapy and sometimes changes associated with colon cancer development. In all such disease states altered intestinal microflora, impaired gut barrier and different types of intestinal inflammation are present. Successful probiotic bacteria are able to survive gastric conditions and colonize the intestine, at least temporarily, by adhering to the intestinal epithelium. Such probiotic microorganisms appear to be promising candidates for the treatment of clinical conditions with abnormal gut microflora and altered gut mucosal barrier functions. They are also promising ingredients to future functional foods and clinical foods for specific disease states provided that basic requirements for strains and clinical studies are carefully followed.
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PMID:Clinical uses of probiotics for stabilizing the gut mucosal barrier: successful strains and future challenges. 899 50


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