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

The present work was designed to study the differentiating effect of butyrate on LS174T cells after modification of their lipids with long-chain fatty acid (LCFA) supplementation. The LCFAs 18:1(n-9), 18:2(n-6), 20:4(n-6), 20:5(n-3), and 22:6(n-3) bound to added to the media of confluent cells for eight days. The fatty acid-to-albumin ratio was 3:1. The concentration of fatty acids in the media was 100 microM. On the last day, half of the flasks were treated with 2 mM butyrate. The data indicate that supplementation with polyunsaturated LCFAs having 20-22 carbon atoms resulted in a significant reduction in cell density and viability, whereas all LCFA supplementation reduced differentiation as measured by alkaline phosphatase activity. Butyrate treatment increased the density, viability, and differentiation of the tumor cells. The effect of butyrate on differentiation was mainly with cells supplemented with 18:1, 20:5, and 22:6. In the absence of LCFA supplementation, butyrate reduced the concentration of 22:5(n-6) in the cellular lipids. Also, butyrate modified the LCFAs incorporated in cells supplemented with 18:2 and 20:5, with changes occurring in 20:5(n-3), 22:5(n-3), and 22:5(n-6). Thus the present study suggests an interaction between butyrate and LCFA on differentiation and LCFA metabolism of human colon cancer cells.
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PMID:Influence of butyrate on lipid metabolism, survival, and differentiation of colon cancer cells. 179 8

We have isolated a set of complementary DNA (cDNA) clones that together encode the alkaline phosphatase of human colon cancer LS174T cells. These clones include two cDNAs isolated from a conventionally prepared oligodeoxythymidylate-primed lambda ZAP cDNA library and three cDNA clones prepared by using the polymerase chain reaction. The deduced amino acid sequence of the alkaline phosphatase primary transcript contains 532 amino acids. This enzyme is similar to, but not identical with, placental alkaline phosphatase (PLAP); it exhibits 12-19 amino acid substitutions when compared to the various alleles of PLAP. Also, it is similar to PLAP in that it is apparently attached to the cell membrane by a phosphatidylinositol-containing anchor as judged by the ability of phosphatidylinositol-specific phospholipase C to release it from membranes. It is different from PLAP however, in terms of its signal sequence which only contains 19 amino acids as compared to 22 for PLAP. Moreover, the 3'-untranslated region of the LS174T cell alkaline phosphatase message diverges considerably from the PLAP message. The LS174T cell alkaline phosphatase cDNAs are actually much more similar to the "germ cell" alkaline phosphatase gene than they are to PLAP. Only 7 amino acid substitutions exist between the LS174T cell enzyme and the alkaline phosphatase encoded by the germ cell alkaline phosphatase genomic DNA clone isolated by Millan and Manes (Proc. Natl. Acad. Sci. USA, 85: 3024-3028, 1988). Furthermore, the 3'-untranslated region of the LS174T cell alkaline phosphatase message is very similar to the sequence immediately downstream of the coding region of the germ cell alkaline phosphatase genomic DNA clone. Thus, these results indicate that this colon cancer cell alkaline phosphatase is likely to represent an allelic variant encoded at the germ cell alkaline phosphatase locus.
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PMID:Molecular cloning of complementary DNAs encoding alkaline phosphatase in human colon cancer cells. 229 57

1,25-Dihydroxyvitamin D3 (1,25-(OH)2D3) greatly enhances sodium butyrate (NaB)-induced enterocyte differentiation of HT-29 human colonic carcinoma cells while 1,25-(OH)2D3 alone induces growth restriction without associated differentiation. In the present study, the efficacies of various analogs of 1,25-(OH)2D3 to enhance NaB-induced HT-29 differentiation and to prolong the reversal of the differentiated phenotype under NaB-free growth conditions were subsequently examined. Extent of HT-29 differentiation was assessed by measurement of alkaline phosphatase (AP) activity, appearance of mucin-producing cells, changes in morphological characteristics, and expression of differentiation-associated cytokeratin proteins. Among active analogs of 1,25-(OH)2D3, 26,26,26,27,27,27-hexafluoro-1,25-(OH)2D3 (F6-1,25-(OH)2D3), 24,24-difluoro-24-homo-1,25-(OH)2D3, and 26,27-dimethyl-1,25-(OH)2D3 were 100-, 10-, and 5-fold, respectively, more effective than 1,25-(OH)2D3 in enhancing NaB-induced mucin production. Combined use of NaB and F6-1,25-(OH)2D3 (10(-9) M) also induced HT-29 cells to form highly differentiated goblet-like enterocytes, and increased both cellular AP enzymatic activity and tissue-type cytokeratin content. This differentiated state was qualitatively more advanced than that achieved by a combination of NaB and 10(-7) M 1,25-(OH)2D3. NaB-mediated HT-29 differentiation (in short-term inductions) was found to be reversible following a return to NaB-free medium. HT-29 cells differentiated by combined use of NaB and 1,25-(OH)2D3 or its analogs exhibited a significant prolonged reversal time relative to cells differentiated with NaB alone. The most prominent effect was achieved using cells differentiated with NaB and 10(-9) M F6-1,25-(OH)2D3 which exhibited a 7-fold prolonged reversal time over colonocytes differentiated by NaB alone. Our data suggest that a combined use of NaB and 1,25-(OH)2D3 or its derivatives may provide a convenient in vitro model system to probe molecular events associated with steroid-target tissue interactions in a differentiating cell system as commonly occurs in vivo. Such an analysis might lend itself to design of a rational combination differentiation-based therapy for the clinical management of colon cancer.
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PMID:Effects of 1,25-dihydroxyvitamin D3 and its analogs on butyrate-induced differentiation of HT-29 human colonic carcinoma cells and on the reversal of the differentiated phenotype. 230 5

The human colon cancer cell line Caco-2 undergoes spontaneous enterocytic differentiation during growth and expresses a number of brush-border membrane-associated hydrolases typical of a differentiated phenotype. Among these is the enzyme alkaline phosphatase, which is frequently used as a marker of cell differentiation in colon cancer cells. Since the biochemical processes regulating the expression of alkaline phosphatase during cell differentiation are only poorly understood, we examined the biosynthesis and processing of alkaline phosphatases in undifferentiated (0-day confluent) and differentiated (14-day confluent) Caco-2 cells. It was found that both cell phenotypes expressed a single, heat-labile intestinal-like enzyme, which undergoes similar post-translational processing and glycosylation. Although the rate of enzyme synthesis and alkaline phosphatase messenger ribonucleic acid was 5-6-fold higher in differentiated cells, the degradation rates in both cell types were similar with a half-life of approximately 10 days. These results suggest that the increase in alkaline phosphatase activity during Caco-2 cell differentiation is caused by changes in the synthetic rate and that the low turnover rates facilitate accumulation of the enzyme. Furthermore, these studies demonstrate that Caco-2 cells are useful for examining the molecular and biochemical events involved in the differentiation of the small intestinal epithelium.
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PMID:Biosynthesis of alkaline phosphatase during differentiation of the human colon cancer cell line Caco-2. 232 13

By using a retrovirus-derived vector system, we generated derivatives of the human colon cancer cell line HT29 that stably overexpress a full-length cDNA encoding the beta 1 isoform of rat protein kinase C (PKC). Two of these cell lines, PKC6 and PKC7, displayed an 11- to 15-fold increase in PKC activity when compared with the C1 control cell line that carries the vector lacking the PKC cDNA insert. Both of the overexpresser cell lines exhibited striking alterations in morphology when exposed to the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Following exposure to TPA, PKC6 and PKC7 cells displayed increased doubling time, decreased saturation density, and loss of anchorage-independent growth in soft agar; but these effects were not seen with the C1 cells. Also, in contrast to the control cells, the PKC-overproducing cells failed to display evidence of differentiation, as measured by alkaline phosphatase activity, when exposed to sodium butyrate. In addition, the PKC-overexpresser cells displayed decreased tumorigenicity in nude mice, even in the absence of treatment with TPA. These results provide the first direct evidence that PKC can inhibit tumor cell growth. Thus, in some tumors, PKC might act as a growth-suppressor gene.
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PMID:Overexpression of protein kinase C in HT29 colon cancer cells causes growth inhibition and tumor suppression. 238 20

Previous studies have shown that fast homoarginine-sensitive alkaline phosphatase (FHAP) is roughly equivalent to CEA (Roche) as a marker in colon cancer. The present study compares FHAP with CEA-EIA (Abbott) as a marker in cancer of the colon, breast, lung, ovary, uterus, skin, and lymph nodes. Comparison is made with regard to sensitivity, specificity, predictive value of a positive test, and diagnostic efficiency. It was determined that FHAP and CEA-EIA were comparable as markers for cancers of the colon, breast, and lung. FHAP was more sensitive and specific and had a higher predictive value and diagnostic efficiency for cancers of the ovary, uterus, skin, and lymph nodes.
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PMID:A comparison of the predictive value and diagnostic efficiency of FHAP and CEA as cancer markers. 243 42

In 1978, a prospective program was initiated to evaluate postoperative monitoring of patients after resection of carcinoma of the colon and rectum. The program included clinical examination, interval endoscopy, measurement of carcinoembryonic antigen (CEA), selected liver function tests (alkaline phosphatase and gamma glutamyl transferase) and roentgenologic testing: roentgenograms of the chest, barium enema, intravenous pyelogram (IVP) and computerized axial tomographic (CAT) scan. Of the initial 226 patients enrolled, 179 had at least one abnormal elevation of the CEA level, and in 70 (39 per cent), recurrence developed. Of the 70 with recurrence, 62 (89 per cent) had elevated CEA levels (greater than 3.0 nanograms per milliliter) prior to detection of recurrence by other means. Eight patients had normal levels (two were false-negative and the other six were tested at inappropriate times). Although other test results often complemented CEA, they were generally less sensitive for early detection. Selective use of these tests frequently documented site and extent of recurrence. The detection sensitivity of these other tests was highest with CAT scan (83 per cent), followed by barium enema and endoscopy (56 and 46 per cent). Forty-five patients underwent re-exploration. Recurrence was found in 42, of whom 23 had resectable disease (five of 11, liver; 17 of 24, local or pelvis, and one of one, lung). In three patients, nothing abnormal was found at exploration; two of these patients ultimately had metastases develop. The median survival time was 43 months and the estimated five year survival rate was 38 per cent. CEA is the best over-all indicator of early recurrence and frequent testing at short intervals is most important. Periodic clinical examination and selected other studies are also essential for early documentation of recurrence. Second-look surgical procedures appear beneficial for survival time in selected patients.
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PMID:Prospective monitoring trial for carcinoma of colon and rectum after surgical resection. 268 53

The human colon cancer line Caco-2 exhibits after confluency a concomitant increase of glycogen accumulation and an enterocytic differentiation. The purpose of this work was to investigate whether forskolin (FK), an activator of adenylate cyclase, would induce a permanent glycogenolysis and, if so, whether it would result in modifications of the differentiation pattern of the cells. FK activates adenylate cyclase in Caco-2 cells with an ED50 of 7 X 10(-6)M. Three different treatment protocols with FK (10(-5)M) were applied: 1) the cells were treated during all the time in culture (20 days); 2) the treatment was started after confluency; 3) the treatment was interrupted after confluency. The presence of FK results in a permanent stimulation of cAMP accumulation (10 to 20 fold the basal values) and in a permanently reduced glycogen content (30 or 50% of the control values). The rates of glucose consumption are increased three and five fold in protocols 1 and 3 respectively. These metabolic changes are associated with morphological changes (tightening of the intercellular spaces and shortening of the brush border microvilli) and with a dual inhibition of the activities of brush border hydrolases: a) an inhibition of the post-confluent increase of activity of sucrase, aminopeptidase N and alkaline phosphatase in the brush border enriched fraction; b) an inhibition of the post-confluent increase of activity of sucrase in the cell homogenate. A comparison of the results obtained in each protocol shows that the morphological modifications and the decrease of the enzyme activities in the brush border fraction are regularly associated with an increased cAMP accumulation, whereas the inhibition of the differentiation of sucrase is a direct consequence of the increase in glucose consumption and decrease in glycogen stores.
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PMID:Enterocytic differentiation and glucose utilization in the human colon tumor cell line Caco-2: modulation by forskolin. 298 31

The incidence, distribution, size, and histopathology of small and large bowel tumors induced by parenteral administration of 1,2-dimethylhydrazine were examined in rats given 1% or 2% sodium butyrate dissolved in drinking water. Although previous in vitro reports on colon cancer cell lines have suggested that sodium butyrate might have a role to play as a chemotherapeutic "differentiating agent," the results of this in vivo study indicate that sodium butyrate treatment enhanced the development of colonic neoplasia and was associated with increased fecal butyric acid concentrations. In contrast, no changes were seen in the incidence of small bowel tumors, luminal butyric acid concentrations, mucosal morphology, or brush-border enzyme activities (i.e., sucrase, alkaline phosphatase). This study suggests that dietary butyrate has an important, possibly indirect, regulatory role in carcinogenesis associated with an experimental animal model of colonic neoplasia.
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PMID:Effects of differing concentrations of sodium butyrate on 1,2-dimethylhydrazine-induced rat intestinal neoplasia. 373 64

To alter the dismal prognosis of multiple unresectable metastases to the liver from carcinoma of the colon and rectum, 30 patients underwent hepatic dearterialization (ligation of the hepatic artery, transection of hepatic ligaments and cholecystectomy) and distal hepatic artery cannulation with prolonged infusion chemotherapy by a portable infusion pump followed by systemic intravenous chemotherapy. Involvement of the liver by carcinoma was less than 50 per cent in 16 and more than 50 per cent in 14 patients. The results of follow-up examinations, LFT, CEA and CT scan studies showed more than 50 per cent regression of the tumor and a decrease in alkaline phosphatase values and CEA in 29 patients (97 per cent); six had complete regression of tumor. The duration of response ranged from five to 39 months with the median of 17 or more months. The results of sequential LFT showed immediate increase in liver enzymes with return to normal in seven to 14 days. The mean CEA value decreased by 69 per cent within the first week and further decreased by 88 per cent in two months at the end of infusion chemotherapy. The over-all and adjusted survival rates from diagnosis were 79 and 91 per cent at 12 months; 56 and 81 per cent at 18 months, and 40 and 65 per cent at 24 months. The over-all and adjusted median survival rate after the treatment was 17 and 23 months, respectively. Of the 14 patients who failed this program, 11 had recurrences at sites other than the liver, with hepatic disease in remission in the majority. Of the 17 patients who died, six died of causes unrelated to the recurrence of disease. Thus, hepatic dearterialization and infusion regional chemotherapy can "effectively" control the hepatic disease and increase over-all survival time from three to six months to 23 months. However, recurrences of extrahepatic carcinoma and other causes are responsible for death and the over-all guarded prognosis.
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PMID:Unresectable hepatic metastases from carcinoma of the colon and rectum. 399 46


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