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

Our previous study shows that cigarette smoking can promote inflammation-associated adenoma formation in the mouse colon, but the underlying mechanism remains unknown. Several studies suggest that there is a link between 5-lipoxygenase (5-LOX) and carcinogenesis in humans and animals. In the present study, we aims to investigate whether the promoting action of cigarette smoke on inflammation-associated colon cancer formation is associated with 5-LOX activation in mice. Results showed that exposure to the mainstream smoke of unfiltered cigarettes enhanced the 5-LOX protein expression in the inflammation-associated colonic adenomas. It was accompanied with an up-regulation of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF). Both are the key angiogenic factors for tumorigenesis. 5-LOX inhibitors decreased the incidence of colonic adenoma formation and reduced angiogenesis, MMP-2 activity and VEGF protein expression in the colons of these animals. Taken together, these results strongly suggest that cigarette smoke can induce 5-LOX expression which plays an important role in activation of MMP-2 and VEGF to induce angiogenic process and promotion of inflammation-associated adenoma formation in mice.
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PMID:Contributory role of 5-lipoxygenase and its association with angiogenesis in the promotion of inflammation-associated colonic tumorigenesis by cigarette smoking. 1536 93

4-[3,5-bis(trimethylsilyl)benzamido] Benzoic acid (TAC-101) has potent antiproliferative, antiangiogenic, and antitumor effects in vitro and in vivo. These effects might be due to TAC-101 binding to retinoic acid receptor alpha (RAR-alpha) and interfering with the binding of activator protein-1 (AP-1) to DNA. However, little is known about the detailed mechanism of TAC-101 function. We investigated the mechanism of the antiangiogenic effect of TAC-101 using a rat hepatic metastatic model in vivo and DLD-1 human colon cancer cells in vitro. Liver metastases were induced by portal injection of RCN-9 rat colonic cancer cells into F344 rats. TAC-101 (8 mg/kg) was orally administered 5 days per week for 4 weeks and then hepatic tumors were immunohistochemically evaluated for microvessel density (MVD) and vascular endothelial growth factor (VEGF). TAC-101 significantly reduced both MVD and VEGF expression. Northern blot analysis and ELISA indicated that TAC-101 efficiently inhibited production of VEGF mRNA and protein in DLD-1 cells in a time- and dose-dependent manner. These findings suggest that TAC-101 may inhibit progression and metastasis in colon cancer by interfering with tumor production of VEGF.
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PMID:4-[3,5-Bis(trimethylsilyl)benzamido] benzoic acid inhibits angiogenesis in colon cancer through reduced expression of vascular endothelial growth factor. 1549 Sep 72

This article reviews the available data regarding the acticity of postoperative adjuvant systemic therapy for colorectal cancer as first and second-line treatment in metastatic disease. The efficacy of adjuvant treatment of patients with stage III colorectal cancer is well established. 5-fluorouracil (5-FU) and folic acid over 6 months (still) represent todays standard and should serve as comparison in randomized studies. The risk of relapse is low in stage II colon carcinoma and consequently the efficacy is relatively small compared to stage III. New investigation indicate, Capecitabene has the potential to replace 5-FU/FS as standard treatment for patients with colon cancer. Efficacy results are expected to be available in 2004. In metastatic disease combination of 5-FU/folic acid plus CPT-11 or OXA are treatment of choice for the first-line therapy of metastatic colorectal carcinoma. FOLFOX is high-dose intensity oxaliplatin added to the simplified bimonthly leucovorin and 5-fluorouracil regimen as second- line therapy for metastatic colorectal cancer. It resulted in prolongation of the median progress free survival from 6,8 to 8,8 months and increased the survival for 4,5 months. New perspectives are novel chemotherapeutic and targeted agents in metastatic colorectal cancer: For the first time, there has been a targeted therapy shown convincingly to prolong survival for patients with unresectable metastatic colorectal cancer in a well-performed Phase III trial. This agent is bevacizumab, a humanised monoclonal antibody targeting the circulating proangiogenic growth factor vascular endothelial growth factor. Results with bevacizumab should lead to rapid expansion of the number of strategies targeting tumour neovasculature. Additionally, an antibody against the epidermal growth factor, cetuximab, has been shown to have both single-agent activity and the potential ability to partially reverse resistance to a chemotherapy drug. These advancements, as well as data on other novel treatment agents that have been studied specifically in patients with colorectal neoplasms, are discussed in detail.
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PMID:[Adjuvant and palliative anticancer treatment of colon carcinoma in 2004]. 1549 53

Epidemiological data suggest that non-steroidal anti-inflammatory drugs prevent colon cancer. The evidence for other types of tumour is less conclusive, though animal and in vitro studies indicate that they may be effective against mammary cancer cells. We assessed the effect of dietary acetylsalicylic and salicylic acid against dimethylbenzanthracene-induced rat tumours. Tumour angiogenesis was also investigated to explore the mechanism responsible for salicylate effect. Mammary tumours were induced in female Sprague-Dawley rats fed with different amounts of acetylsalicylic and salicylic acid. Serum vascular endothelial growth factor concentrations were measured and vascularization of basement membrane proteins injected in vivo (Matrigel) was determined by evaluation of haemoglobin content to assess the extent to which angiogenesis was inhibited. Dimethylbenzanthracene-induced carcinogenesis was inhibited by both acids and there was a log-dose/response correlation between the tumour diameter and salicylate concentration. Salicylic acid seems more effective than acetylsalicylic acid. Vascular endothelial growth factor was less concentrated in treated animals than in the controls and so was Matrigel haemoglobin. The mechanism involved, however, is still uncertain, though concomitant inhibition of tumour angiogenesis may be an important component. The documented salicylate serum VEGF modulation is interesting also for presence of the flk-1 receptor in mammary tumour cells of our model. Although misoprostol is a prostaglandin analogous its concomitant administration did not compromise the salicylate anti-tumour effect.
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PMID:Salicylate inhibition of rat mammary carcinogenesis and angiogenesis in female rat compatible with misoprostol administration. 1570 26

Recently, major developments in the treatment of colon cancer have emerged. These developments include improvements in surgical technique and staging and the introduction of new molecularly targeted pharmacologic agents. Improvements in surgical management involve enhanced staging techniques, allowing more accurate determination of risk of recurrence. Newer agents, such as oxaliplatin, cetuximab, and bevacizumab, now are approved for the treatment of colon cancer. The data associated with use of oxaliplatin in adjuvant and metastatic settings continue to mature; survival benefits are expected to become more fully apparent in the next two years. Bevacizumab, a monoclonal antibody that neutralizes vascular endothelial growth factor, when combined with irinotecan, 5-fluorouracil, and leucovorin (IFL), was superior to IFL alone in achieving median and progression-free survival. Cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, when given in combination with irinotecan, achieved an increased objective response and increased time to progression, compared with cetuximab alone, in patients refractory to irinotecan-containing regimens. In addition to surgical and pharmacologic developments, the recognition that genetics and molecular markers play an important role in carcinogenesis has heightened research to integrate this knowledge into practice. Nurses play a pivotal role in the care of patients with colon cancer and must be conversant in the new advances in treatment.
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PMID:Therapeutic options in the management of colon cancer: 2005 update. 1575 97

We studied growth factors and their receptors in tumor cells and tumor-associated endothelial cells as the therapeutic targets in colon cancer. Immunohistochemical analysis of 13 surgical specimens of human colon adenocarcinoma revealed that both tumor cells and tumor-associated endothelial cells in 11 of the 13 specimens expressed the epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), EGF receptor (EGFR), phosphorylated EGFR (pEGFR), vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR), and phosphorylated VEGFR (pVEGFR). HT29 human colon cancer cells growing orthotopically in the cecum of nude mice expressed a high level of EGF, EGFR, pEGFR, VEGF, VEGFR, and pVEGFR. Double-immunofluorescence staining found that tumor-associated mouse endothelial cells also expressed pEGFR and pVEGFR. Tumors in mice treated for 5 weeks with oral AEE788 (an inhibitor of EGFR and VEGFR tyrosine kinase) as a single agent or with CPT-11 alone were smaller (>50%) than those in control mice. Mice treated with the combination of AEE788 and CPT-11 had significantly smaller tumors (P < 0.01) and complete inhibition of lymph node metastasis. AEE788 alone or in combination with CPT-11 inhibited pEGFR, pVEGFR, and phosphorylated Akt expression on tumor-associated endothelial cells as well as on tumor cells. The combination therapy also significantly decreased microvessel density and tumor cell proliferation and increased the level of apoptosis in both tumor cells and tumor-associated endothelial cells. Collectively, these data suggest that the dual inhibition of EGFR and VEGFR signaling pathways in tumor cells and tumor-associated endothelial cells in combination with chemotherapy can provide a new approach to the treatment of colon cancer.
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PMID:Dual inhibition of epidermal growth factor receptor and vascular endothelial growth factor receptor phosphorylation by AEE788 reduces growth and metastasis of human colon carcinoma in an orthotopic nude mouse model. 1586 67

Cyclooxygenase 2 (COX-2) inhibitors, such as celecoxib (Cel), nimesulfide (NM), and NS-398 [NS; N-[2-(cyclohexyloxy)-4-nitrophenyl]methanesulfonamide] and other nonsteroidal anti-inflammatory drugs inhibit colon cancer growth and angiogenesis; however, the mechanism of this response is not well defined. Treatment of SW-480 colon cancer cells with Cel, NS, or NM decreased vascular endothelial growth factor (VEGF) mRNA and immunoreactive protein expression. This was also accompanied by decreased transactivation in cells transfected with constructs containing VEGF gene promoter inserts. Deletion analysis of the VEGF promoter indicated that decreased VEGF expression by COX-2 inhibitors was associated with the proximal -131 to -47 GC-rich region of the VEGF promoter that binds Sp proteins. Treatment of SW-480 cells with Cel, NM, and NS also decreased Sp1 and Sp4 protein expression but not that of Sp2 or Sp3. Similar results were observed in RKO, HT-29, and DLD colon cancer cells demonstrating comparable responses in COX-2-expressing and -nonexpressing colon cancer cell lines. COX-2 inhibitors do not affect Sp1 or Sp4 mRNA levels in SW-480 cells; however, decreased expression of both proteins was accompanied by increased protein ubiquitination and inhibited by the proteasome inhibitor gliotoxin. These results suggest that the antiangiogenic activity of COX-2 inhibitors in colon cancer cells is linked to activation of proteasome-dependent degradation of Sp1 and Sp4 proteins.
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PMID:Cyclooxygenase-2 inhibitors decrease vascular endothelial growth factor expression in colon cancer cells by enhanced degradation of Sp1 and Sp4 proteins. 1588 3

A cDNA fragment coding for domains I and II of mouse macrophage metalloelastase (MME) was transfected into murine CT-26 colon cancer cells that are MME deficient. An orthotopic implantation model was established by using MME-transfected cells. In MME-transfected primary tumors, it demonstrated that tumor growth and microvessel formation were significantly inhibited compared with the controls. The expression of vascular endothelial growth factor (VEGF) mRNA and protein was significantly lower in MME-transfected group compared with those in the controls. Our data show that both MME and VEGF gene expression is highly associated with the vascularity of tumors, which may depend on a balance between MME and VEGF expression.
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PMID:Transfection of mouse macrophage metalloelastase gene into murine CT-26 colon cancer cells suppresses orthotopic tumor growth, angiogenesis and vascular endothelial growth factor expression. 1588 86

Cyclooxygenase and its derived prostaglandin E2 (PGE2) have been shown to stimulate the growth of cancer cells and promote tumor angiogenesis. Here, we show that PGE2 activated the beta-catenin/T cell factor-dependent transcription in colon cancer cells through the cAMP/protein kinase A pathway. The expression of cyclin D1 and vascular endothelial growth factor was induced by PGE2 in LS-174T cells. Moreover, PGE2 and mutated beta-catenin stimulated the transcription of cyclin D1 and vascular endothelial growth factor in a synergistic fashion. Mechanistically, PGE2 increased the phosphorylation of glycogen synthase kinase-3 and consequently accumulated beta-catenin. In addition, PGE2 induced the expression of T cell factor-4 transcription factor, which formed transcriptionally active complex with beta-catenin. In animal experiments, administration of 16,16-dimethyl PGE2 strongly increased the expression of cyclin D1 and vascular endothelial growth factor in APC(min/+) mouse polyps. Thus, our results provide a novel mechanism, suggesting that cyclooxygenase-2/PGE2 may exert pro-oncogenic actions through stimulating the beta-catenin/T cell factor-mediated transcription, which plays critical roles in colorectal carcinogenesis.
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PMID:Prostaglandin E2 Stimulates the beta-catenin/T cell factor-dependent transcription in colon cancer. 1589 4

After a long period without change, colorectal oncology has in recent years entered the frontline of progress in cancer treatment and research. Improved diagnostic techniques have brought forward the diagnosis of metastatic disease, enabling potential curative surgery in the case of liver metastases. Due to both the earlier start of systemic treatment and the increase in number of active drugs, survival of patients with metastatic disease has increased to a median of approximately 18 months. Two important cytotoxic drugs, oxaliplatin and irinotecan, have contributed to this progress. Recently, it was demonstrated that addition ofa monoclonal antibody against vascular endothelial growth factor, bevacizumab, led to an increase in survival comparable to the effects of both cytotoxic agents. Increase in survival, as a hallmark for drug efficacy, is an endpoint that patients and the medical community seem to agree on. The financial consequences of these combinations for the hospital budget are considerable, but their share in the total drug economy is still small. Oxaliplatin has also emerged as a useful drug in the adjuvant setting, after surgery for primary colon cancer.
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PMID:[New oncolytic agents and immunomodulators and their application]. 1623 8


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