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

The vascular endothelial growth factor (VEGF) plays a central role in promoting angiogenesis, and it is the target of innovative anti-cancer therapies. In colorectal carcinomas, differences in the VEGF expression have been found between the primary tumor and its metastases. We postulated that differences in the VEGF expression may also exist between liver and abdominal metastases from colon cancer. Consecutive colon cancer patients with liver or abdominal metastases were considered eligible for the study. Biopsies had to be performed before chemotherapy and the VEGF analysis were conducted through immunohistochemistry. The staining results were correlated to the metastatic pattern. The study population consisted of 41 patients with a metastatic site in the liver in 19 patients and the abdomen in 22 patients. A positive VEGF staining was found in 19 of the 41 metastatic samples (46%). Cases with positive VEGF expression were found more frequently in abdominal (15 out of 22 patients; 68%) than in liver metastases (4 out of 19 patients; 21%). Also, the degree of VEGF immunoreactivity was significantly higher in abdominal than in liver metastases. Evidence is supported that the VEGF expression may be different between colon cancer metastatic sites. The efficacy of anti-VEGF treatments may depend on the VEGF expression status, and this finding deserves further investigation.
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PMID:Differences of vascular endothelial growth factor (VEGF) expression between liver and abdominal metastases from colon cancer. Implications for the treatment with VEGF inhibitors. 1182 68

Sodium butyrate (NaB), a short-chain fatty acid naturally present in the human colon, is able to induce cell cycle arrest, differentiation and apoptosis in colon cancer cells. In addition to these effects, we investigated the effect of NaB on two angiogenesis-related proteins in a colon carcinoma cell line (HT29): vascular endothelial growth factor (VEGF), the most potent angiogenic factor, and hypoxia-inducible factor (HIF)-1alpha, the main transcription activator of the VEGF gene, which are both constitutively expressed at high levels in HT29 also in normoxic conditions. NaB treatment had a different effect on VEGF165 and HIF-1alpha expression. In fact, it induced a dose-dependent down regulation of the VEGF165 protein level that was not paralleled by a concomitant down regulation of the corresponding mRNA, suggesting a post-translational regulation of the factor. Conversely, after 24 h of treatment all the tested NaB concentrations reduced the HIF-1alpha protein level, whereas after a longer time of exposure HIF-1alpha level increased in the presence of a high NaB concentration (2 mM) with a concomitant increase in HIF-1alpha mRNA. These results indicate that NaB, besides regulating other fundamental cellular processes, is able to modulate the expression of two important angiogenesis-related molecules and suggested a further possible clinical application of this short-chain fatty acid as an anti-angiogenic compound in association with conventional chemotherapeutic agents.
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PMID:Modulation of angiogenesis-related proteins synthesis by sodium butyrate in colon cancer cell line HT29. 1201 45

Stimulation of human colon cancer cells with insulin-like growth factor 1 (IGF-1) induces expression of the VEGF gene, encoding vascular endothelial growth factor. In this article we demonstrate that exposure of HCT116 human colon carcinoma cells to IGF-1 induces the expression of HIF-1 alpha, the regulated subunit of hypoxia-inducible factor 1, a known transactivator of the VEGF gene. In contrast to hypoxia, which induces HIF-1 alpha expression by inhibiting its ubiquitination and degradation, IGF-1 did not inhibit these processes, indicating an effect on HIF-1 alpha protein synthesis. IGF-1 stimulation of HIF-1 alpha protein and VEGF mRNA expression was inhibited by treating cells with inhibitors of phosphatidylinositol 3-kinase and MAP kinase signaling pathways. These inhibitors also blocked the IGF-1-induced phosphorylation of the translational regulatory proteins 4E-BP1, p70 S6 kinase, and eIF-4E, thus providing a mechanism for the modulation of HIF-1 alpha protein synthesis. Forced expression of a constitutively active form of the MAP kinase kinase, MEK2, was sufficient to induce HIF-1 alpha protein and VEGF mRNA expression. Involvement of the MAP kinase pathway represents a novel mechanism for the induction of HIF-1 alpha protein expression in human cancer cells.
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PMID:Insulin-like growth factor 1 induces hypoxia-inducible factor 1-mediated vascular endothelial growth factor expression, which is dependent on MAP kinase and phosphatidylinositol 3-kinase signaling in colon cancer cells. 1214 54

We wished to demonstrate vascular endothelial growth factor (VEGF) transcript polymorphism in human colon cancer. RNA was extracted from 25 primary human colorectal adenocarcinomas followed by VEGF transcript amplification, fragment elution, subcloning, positive selection via insert analysis and sequencing. Four distinct splice variants were consistently expressed in cancer, including VEGF121, VEGF165, VEGF189 and the newly identified truncated splice variant VEGF145. Six novel mutations were characterized, all of which occurred within the conserved expression site of the gene and which consequently were present in all splice forms. Five cancers exhibited single nucleotide changes and 1 cancer a 2-nucleotide deletion. A silent mutation was observed in exon 1 at position +70 relative to the amplification start site, a 1- and 2-base deletion with frameshift and protein truncation in exon 3 at positions +172 and +171/172, respectively, a transition mutation in exon 3 at position +248 and 2 transition mutations in exon 4 at positions +398 and +403. All of these sense mutations should alter protein conformation. To our knowledge, this is the first report of VEGF145 in solid malignancy. Its biologic activity remains to be determined. We have demonstrated a variety of sporadic mutations within human colorectal cancer VEGF mRNA. Mutant angiogenic VEGF may provide a genomic basis for the diversity of tumor-host response and may prove to be important in antisense oligonucleotide targeting, since all the different VEGF isoforms would have to be neutralized to prevent angiogenesis.
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PMID:VEGF isoforms and mutations in human colorectal cancer. 1220 85

Administration of adenovirus (Ad) vectors to animals induces innate immune responses, typified by elevated interleukin-6 (IL-6). To assess innate responses to Ad vectors in humans, we evaluated serum IL-6 following administration of E1(-) E3(-) Ad vectors to different human hosts and the relationship among peak IL-6 and peak anti-Ad neutralizing antibodies. We administered: 1) Ad(GV)CFTR.10, a vector carrying the normal human CFTR cDNA (3 x 10(7) to 2 x 10(10) particle units (pu)) to airways of individuals with cystic fibrosis (CF); 2) Ad(GV)VEGF121.10, a vector carrying the normal human vascular endothelial growth factor (VEGF)121 cDNA, to the myocardium (4 x 10(8) to 4 x 10(10) pu) of individuals with coronary artery disease (CAD) and to lower extremity muscles (4 x 10(8) to 4 x 10(9.5) pu) of individuals with peripheral vascular disease (PVD); and 3) Ad(GV)CD.10, a vector carrying the Escherichia coli cytosine deaminase gene to skin (7 x 10(7) to 7 x 10(9) pu) and airways (7 x 10(8) to 7 x 10(10) pu) of normal individuals and to liver metastasis (4 x 10(8) to 4 x 10(9) pu) of individuals with colon carcinoma. IL-6 increased mildly (up to 220 pg/ml) following vector administration to skin and lung airways of normal individuals and of individuals with CF, and to muscle and liver metastasis of individuals with PVD and colon cancer, respectively. IL-6 responses were higher (up to 1100 pg/ml) following myocardial administration. Control individuals who had chest surgery and bronchoscopy, but no vector administration, had comparable IL-6 increases. Thus, both administration of Ad vectors of humans up to 10(10) pu and the procedures used to administer the vectors elicit systemic IL-6 responses. There was no correlation among peak IL-6 and peak anti-Ad antibodies. These observations indicate that the innate host responses following administration of Ad vectors to humans may result from the procedures used to administer the vector, and from the vector per se.
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PMID:Systemic interleukin-6 responses following administration of adenovirus gene transfer vectors to humans by different routes. 1234 28

We investigated a number of biological markers, evaluated under strict intralaboratory quality control conditions, in terms of their role in predicting clinical outcome of patients with colon cancer treated with 5-FU-containing regimens. Colon cancer tissue from 263 patients enrolled onto two randomised clinical trials were studied for their cytofluorimetrically determined DNA content and their immunohistochemically evaluated microvessel density, vascular endothelial growth factor expression, thymidylate synthase expression and tumour lymphocyte infiltration. Disease-free survival and overall survival of patients were analysed as a function of the different variables. At a median follow up of 57 months, age, gender and Dukes' stage showed an impact on disease-free survival, whereas no biological marker emerged as an indicator of better or worse disease-free survival. Only histological grade and Dukes' stage were found to influence overall survival. The different biological variables, studied with particular attention for determination reliability, proved to have no impact on the clinical outcome of patients with colon cancer. Therefore, other markers must be identified to complement clinico-pathological variables in the management of this disease.
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PMID:Role of biological markers in the clinical outcome of colon cancer. 1237 1

Insulin-like growth factors and their principal receptor, IGF-I receptor (IGF-IR), are frequently expressed in human colon cancers and play a role in preventing apoptosis, enhancing cell proliferation, and inducing expression of vascular endothelial growth factor (VEGF). The role of IGF-IR in regulating angiogenesis and metastases of human colon cancer has not been elucidated. To determine the in vitro and in vivo effects of IGF-IR in human colon cancer growth and angiogenesis, human KM12L4 colon cancer cells were transfected with a truncated dominant-negative form of IGF-IR (IGF-IR dom-neg). IGF-IR dom-neg-transfected cells demonstrated markedly decreased constitutive expression of VEGF mRNA and protein. Subcutaneous injections of IGF-IR dom-neg-transfected cells in nude mice led to significantly decreased tumor growth (p < 0.05) that was associated with decreased tumor cell proliferation, VEGF expression, and vessel count and with increased tumor cell apoptosis (p < 0.05 for all parameters compared with controls). In addition, pericyte coverage of endothelial cells was significantly decreased in tumors from IGF-IR dom-neg-transfected cells. Following this observation, we demonstrated in vitro that vascular smooth muscle cells migrated significantly less in conditioned medium derived from IGF-IR dom-neg-transfected cells compared with medium from control cells. After splenic injections, IGF-IR dom-neg transfectants failed to produce liver metastases, in contrast to parental cells and mock transfectants (p < 0.05). In addition, IGF-IR dom-neg-transfected cells failed to form liver tumors after direct injection into the liver. These studies demonstrate that the IGF-IR plays an important role in multiple mechanisms that mediate the growth, angiogenesis, and metastasis of human colon cancer. IGF-IR is a valid target for the therapy of human colon cancer.
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PMID:Impact of insulin-like growth factor receptor-I function on angiogenesis, growth, and metastasis of colon cancer. 1237 72

Angiopoietin-1 is an important regulator of endothelial cell survival. Angiopoietin-1 also reduces vascular permeability mediated by vascular endothelial growth factor. The effects of angiopoietin-1 on tumour growth and angiogenesis are controversial. We hypothesised that angiopoietin-1 would decrease tumour growth and ascites formation in peritoneal carcinomatosis. Human colon cancer cells (KM12L4) were transfected with vector (pcDNA) alone (control) or vector containing angiopoietin-1 and injected into the peritoneal cavities of mice. After 30 days, the following parameters were measured: number of peritoneal nodules, ascites volume, and diameter of the largest tumour. Effects of angiopoietin-1 on vascular permeability were investigated using an intradermal Miles assay with conditioned media from transfected cells. Seven of the nine mice in the pcDNA group developed ascites (1.3+/-0.5 ml (mean+/-s.e.m.)), whereas no ascites was detectable in the angiopoietin-1 group (0 out of 10) (P<0.01). Number of peritoneal metastases (P<0.05), tumour volume, (P<0.05), vessel counts (P<0.01), and tumour cell proliferation (P<0.01) were significantly reduced in angiopoietin-1-expressing tumours. Conditioned medium from angiopoietin-1-transfected cells decreased vascular permeability more than did conditioned medium from control cells (P<0.05). Our results suggest that angiopoietin-1 is an important mediator of angiogenesis and vascular permeability and thus could theoretically serve as an anti-neoplastic agent for patients with carcinomatosis from colorectal cancer.
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PMID:Angiopoietin-1 inhibits tumour growth and ascites formation in a murine model of peritoneal carcinomatosis. 1240 60

The 189 amino acid isoform of vascular endothelial growth factor (VEGF189) has been shown to be more strongly associated with the cell membrane than other isoforms of human VEGF (VEGF121, VEGF165). To analyze the biological activities of these VEGF isoforms on tumor growth, we transfected human VEGF121, VEGF165 or VEGF189 cDNA into the human colon cancer cell line SW-480, and established several clones overexpressing these VEGF isoforms. The total amounts of VEGF protein in the culture supernatants of the VEGF189-transfectants were less than those of VEGF121 and VEGF165-transfectants. These transfectants showed no significant differences in growth in culture. Nevertheless, the rate of in vivo tumor growth of VEGF189-transfectants was faster than or equivalent to that of VEGF121-transfectants, while the VEGF165-transfectant showed the greatest enhancement of tumor growth. The protein levels of VEGF were markedly increased only in the VEGF189-transfectants cultured in the presence of heparin. The enhanced in vivo tumor growth of VEGF189-transfectants can be partly explained by the cell-associated features of VEGF189 molecules. The VEGF189 molecule, which is strongly bound to the cell surface, has unique properties and high potential in local angiogenesis and tumor growth in the cancer inductive microenvironment.
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PMID:Unique properties of 189 amino acid isoform of vascular endothelial growth factor in tumorigenesis. 1242 75

We previously reported that vessel count, vascular endothelial growth factor (VEGF) and platelet derived endothelial cell growth factor (PD-ECGF) expression are associated with metastasis formation in human colon cancer. This study was done to determine a stage of colon cancer progression where induction of these factors occurred (i.e. the angiogenic switch). We examined vessel count, VEGF, and matrix metalloproteinase (MMP)-7 expression in cancer cells and PD-ECGF expression in infiltrating cells in 25 adenomas, 35 mucosal cancers (Tis), 29 submucosal invasive cancers (T1) and 33 muscularis propria invasive cancers (T2) by immunostaining. The intensity of staining of VEGF and MMP-7 was evaluated blindly at the invasive edge and was confirmed by image analysis. Intensity of staining for these factors was graded on a scale of 0 to 3+, with 0 representing no detectable stain and 3+ representing the strongest stain. Intensites of PD-ECGF-positive infiltrating cells were similar on a scale 0 to 3+, as previous studies from our laboratory have demonstrated that PD-ECGF is expressed primarily in tumor infiltrating cells. The vessel density was 12.7+/-2.2 (SE) in adenoma, 11.8+/-1.7 in Tis, 35.0+/-6.5 in T1, and 35.2+/-5.3 in T2. There were significant differences in vessel densities between Tis and T1 (p<0.001). The intensities of VEGF expression were 0.6+/-0.1, 0.9+/-0.2, 1.7+/-0.3, and 1.8+/-0.3 for adenoma, Tis, T1 and T2, respectively, with significant differences between in Tis and T1 (p<0.001). There were also significant differences in the intensities of the expression of MMP-7 and PD-ECGF between Tis and T1. These results suggest that angiogenic switch may occur between Tis and T1, i.e. simultaneous to initiation of invasion, in the early development of colon cancer.
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PMID:The angiogenic switch of human colon cancer occurs simultaneous to initiation of invasion. 1246 36


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