Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0596263 (carcinogenesis)
 64,820 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of epidemiological, experimental and preliminary clinical trials strongly suggest that mesalazine or 5-aminosalicyclic acid (5-ASA) may have antineoplastic and potentially prophylactic chemopreventive properties. It is assumed that mesalazine may have similar genetic and molecular targets as nonsteroidal anti-inflammatory drugs (NSAIDs), which is further supported by its close similarity with aspirin, differing only in its structure by the presence of an amino group at position 5 of the benzene ring. The putative chemopreventive actions include the inhibition of inflammatory cascades and/or reactions involved in cell growth and proliferation, such as cyclo-oxygenase (COX-1 and COX-2), which regulate cell proliferation through the formation of prostaglandins; lipoxygenase; nuclear factor kappaB (NFkappaB), responsible for the subsequent expression of pro-inflammatory molecules; MAP kinases and Bcl-2, as well as the activation of apoptotic processes, such as the stimulation of intestinal sphingomyelinase. The peroxisome-proliferator-activated receptor delta (PPARdelta), which also regulates gene transcription, is thought to play a role in both inflammatory and non-inflammatory driven carcinogenesis. This may be another significant target. It is hypothesized that 5-ASAs may prevent the enhancing effect of prostaglandins on PPARdelta binding to DNA by its COX inhibitory properties, decreasing proliferation of colorectal mucosal cells in non-inflammatory bowel disease patients with sporadic polyps of the large bowel.
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PMID:Review article: mechanisms of action of mesalazine in preventing colorectal carcinoma in inflammatory bowel disease. 1295 Apr 15

Roles for host immune response in carcinogenesis are not well defined. Recent studies have shown that microbially driven inflammation can lead to colon cancer and that prior transfer of regulatory lymphocytes expressing CD4 and CD25 prevents the innate inflammatory events that lead to colon cancer in mice. To further examine the ability of regulatory lymphocytes to inhibit carcinogenesis, 129/SvEv Rag-2-deficient mice were inoculated by gastric gavage with Helicobacter hepaticus, an enteric bacterial pathogen of mice. Mice were then treated at 1, 3, or 12 months after infection with adoptive transfer of CD4(+)CD45RB(lo)CD25(+)-regulatory cells. Mice dosed with regulatory cells at 4 or 12 weeks after H. hepaticus infection had reduced severity of inflammatory bowel disease and significantly lower risk of colon cancer during the 8 month observation period, compared with infected mice that had not received cells. This suggested that regulatory cells were able to interrupt the ongoing innate immune events in the stepwise progression to cancer. Transfer of regulatory cells into chronically infected mice with established cancer reduced severity of colitis, epithelial dysplasia, and cancer, but did not eliminate all tumors. Regulatory cells lacking anti-inflammatory cytokine interleukin (IL)-10 were unable to inhibit inflammatory bowel disease, dysplasia, or cancer, showing that IL-10 was required for the protective effects of lymphocytes in this setting. Taken together, the data suggest that IL-10-mediated suppression of host innate inflammatory response was pivotal in interrupting carcinogenesis. Regulatory lymphocytes and cytokines may have implications for novel therapies for colon cancer in humans.
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PMID:CD4(+)CD25(+) regulatory lymphocytes require interleukin 10 to interrupt colon carcinogenesis in mice. 1452 33

Patients with ulcerative colitis have an increased risk of developing colorectal cancer. Telomerase appears to be associated with cellular immortality and might serve as a diagnostic and prognostic marker in carcinogenesis. To test this hypothesis we measured telomerase by a score from 0 (no activity) to 4 (very high activity) in specimens obtained surgically from seven patients with adenocarcinoma of the colon. Intraindividual comparison was made among normal tissue (mean score +/- SD: 0.7 +/- 1.0), tissues adjacent to the tumor (2.7 +/- 0.8), and the tumor center (3.0 +/- 1.0). In addition, from 18 patients with ulcerative colitis, 10 patients with Crohn's disease, and 14 patients without chronic inflammatory bowel disease, biopsies were collected from normal and inflamed areas of the colon. Independent of the duration (0-32 years), grade, and location of the diseases, the telomerase activities were comparable, ranging from 0.4 to 1.0 in ulcerative colitis and from 0.3 to 0.6 in Crohn's disease and averaging 0.4 in controls. Apparently low telomerase activities are present in the mucosa of all patients and the enzyme is not yet upregulated in the potentially premalignant state of active ulcerative colitis, dismissing its prognostic value as an early tumor marker for this disorder.
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PMID:Telomerase activity in chronic inflammatory bowel disease. 1471 21

Patients with ulcerative colitis and Crohn's disease are at increased risk for developing colorectal cancer. To date, no known genetic basis has been identified to explain colorectal cancer predisposition in these inflammatory bowel diseases. Instead, it is assumed that chronic inflammation is what causes cancer. This is supported by the fact that colon cancer risk increases with longer duration of colitis, greater anatomic extent of colitis, the concomitant presence of other inflammatory manifestations such as primary sclerosing cholangitis, and the fact that certain drugs used to treat inflammation, such as 5-aminosalicylates and steroids, may prevent the development of colorectal cancer. The major carcinogenic pathways that lead to sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also occur in colitis-associated colorectal cancers. Unlike normal colonic mucosa, however, inflamed colonic mucosa demonstrates abnormalities in these molecular pathways even before any histological evidence of dysplasia or cancer. Whereas the reasons for this are unknown, oxidative stress likely plays a role. Reactive oxygen and nitrogen species produced by inflammatory cells can interact with key genes involved in carcinogenic pathways such as p53, DNA mismatch repair genes, and even DNA base excision-repair genes. Other factors such as NF-kappaB and cyclooxygenases may also contribute. Administering agents that cause colitis in healthy rodents or genetically engineered cancer-prone mice accelerates the development of colorectal cancer. Mice genetically prone to inflammatory bowel disease also develop colorectal cancer especially in the presence of bacterial colonization. These observations offer compelling support for the role of inflammation in colon carcinogenesis.
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PMID:Inflammation and cancer IV. Colorectal cancer in inflammatory bowel disease: the role of inflammation. 1519 58

The specialty of colon and rectal surgery, a specialty of general surgery, has evolved from the field of proctology. Clinical care has demonstrated decreased number of patients requiring intestinal stomas, improved quality of life in patients with benign anorectal disorders, and more favorable results in patients afflicted with primary and recurrent colorectal cancer. Basic science investigations have spawned from clinical questions such as the molecular biology of colorectal cancer, use of cyclooxygenase inhibitors and polyp regression, and novel cytokine antagonists in inflammatory bowel disease. Medical students are exposed to surgeons with expertise in anorectal anatomy and physiology, mechanisms of carcinogenesis and the importance of screening for detection of colorectal cancer, and novel therapies for inflammatory bowel disease. Surgical residents benefit by having a colorectal surgeon on the faculty by repetitive exposure to anorectal surgery, low pelvic anastomoses, stoma creation and closure, and surgery involving the small intestine. Senior colorectal surgeons will develop critical pathways for the healthcare delivery of patients afflicted with colorectal disease. The specialty of colorectal surgery will continue to translate into improved patient care and positively impact in academic medicine by providing expertise into student and resident training and generate highly sophisticated clinical and basic science investigations.
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PMID:The specialty of colon and rectal surgery: its impact on patient care and role in academic medicine. 1536 33

Elucidation of the evolution of inflammatory bowel disease (IBD) to cancer by clinical symptoms and histopathology of biopsies is important. Fourier transform infrared microspectroscopy (FTIR-MSP) has shown promise as a diagnostic tool for distinction of normal and cancer cells and tissues. In the present work, FTIR-MSP is used to evaluate IBD cases and to study the IR spectral characteristic with respect to cancer and normal tissues from formalin-fixed colonic biopsies from patients. Specific regions of the spectra were analyzed by statistical tools to study variations in metabolites that signified changes between the two pathological conditions: IBD and cancer. IBD tissues can be grouped with cancer or normal tissue using certain parameters such as phosphate content and RNA/DNA ratio as calculated from the spectra and show intermediate levels with regard to these metabolites. Further classification of the spectra by cluster analysis indicated which cases of Crohn's disease (3 of 10 cases) or ulcerative colitis (7 of 10 cases) were more likely to progress to cancer. The study exhibits that FTIR-MSP can detect gross biochemical changes in morphologically identical IBD and cancer tissues and suggest which cases of IBD may require further evaluation for carcinogenesis.
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PMID:Inflammatory bowel diseases as an intermediate stage between normal and cancer: a FTIR-microspectroscopy approach. 1545 32

Inflammatory bowel disease (IBD) has a multifactorial etiology and includes ulcerative colitis (UC) and Crohn's disease (CD). Powerful epidemiologic and genetic studies have provided ample evidence that a subset of both CD and UC are attributable to a likely primary genetic etiology. This is evidenced by the recent identification of the IBD1 gene ( NOD2 ) mutations which show an association with susceptibility to CD. The IBD complex shows a significant increased frequency in Jews when compared to non-Jews. While there is an increased incidence of colorectal cancer (CRC) in patients with IBD, it nevertheless is important to realize that IBD likely accounts for no more than 1-3% of all cases of CRC in Ashkenazi Jews. Importantly, however, awareness of the increased CRC risk in IBD may aid immeasurably in preventive interventions. The molecular pathway leading to CRC in IBD appears to differ from the well-known adenoma-to-CRC sequence, given the fact that these cancers appear to arise from either flat, dysplastic tissue or dysplasia-associated lesions or masses (DALMs). An important model, but by no means an absolute one, for colon carcinogenesis in IBD follows progression from an absence of dysplasia, to indefinite dysplasia, to low-grade dysplasia, on to high-grade dysplasia, and ultimately to invasive CRC. This carcinogenic process relates to the disease duration with respect to the extent of colonic involvement and may also involve primary sclerosing cholangitis. Given this knowledge of an increased risk for CRC in UC and CD, surveillance colonoscopy should initially be performed 8-10 years after onset of symptoms as opposed to diagnosis, and it should be performed 1-2 years after 8 years of disease in patients with pancolitis or after 15 years in those with left-sided colitis. A search for dysplasia of colonic mucosa with biopsies performed in all four quadrants every 10 cm throughout the colon is exceedingly important. Additional biopsies should be taken of any flat lesions, masses, or strictures. Prophylactic colectomy may then be indicated when severe dysplasia is confirmed by knowledgeable pathologists.
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PMID:Inflammatory bowel disease in Ashkenazi Jews: implications for familial colorectal cancer. 1551 46

Inflammatory bowel disease (IBD) is classically subdivided into ulcerative colitis (UC) and Crohn's disease (CD). Patients with IBD have increased risk for colorectal cancer. Because the pathogenesis of colorectal carcinoma has not been entirely defined yet and there is no ideal treatment for colon cancer, cancer prevention has become increasingly important in patients with IBD. The two adopted methods to prevent the development of colon cancer in clinical practice include the prophylactic colectomy and colonoscopic surveillance. But patients and physicians seldom accept colectomy as a routine preventive method and most patients do not undergo appropriate colonoscopic surveillance. Chemoprevention refers to the use of natural or synthetic chemical agents to reverse, suppress, or to delay the process of carcinogenesis. Chemoprevention is a particularly useful method in the management of patients at high risk for the development of specific cancers based on inborn genetic susceptibility, the presence of cancer-associated disease, or other known risk factors. Prevention of colorectal cancer by administration of chemopreventive agents is one of the most promising options for IBD patients who are at increased risks of the disease. The chemopreventive efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) against intestinal tumors has been well established. But with reports that NSAIDs aggravated the symptoms of colitis, their sustained use for the purpose of cancer chemoprevention has been relatively contraindicated in IBD patients. Another hopeful candidate chemoprevention drug for IBD patients is 5-aminosalicylic acid (5-ASA), which is well tolerated by most patients and has limited systemic adverse effects, and no gastrointestinal toxicity. 5-ASA lacks the well-known side effects of long-term NSAIDs use. Retrospective correlative studies have suggested that the long-term use of 5-ASA in IBD patients may significantly reduce the risk of development of colorectal cancer. According to the literature, this agent might well satisfy clinical expectations with respect to a safe and effective chemopreventive agent.
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PMID:5-aminosalicylic acid is an attractive candidate agent for chemoprevention of colon cancer in patients with inflammatory bowel disease. 1563 33

Oxidative stress has been shown to play a pivotal role in the onset of inflammatory bowel disease (IBD) and carcinogenesis. We evaluated the effects of two dietary anti-oxidants, rutin and its aglycone quercetin, on dextran sulfate sodium (DSS)-induced experimental colitis in mice. Female ICR mice were fed a diet containing 0.1% rutin or 0.1% quercetin for 2 weeks, and given 5% DSS in drinking water during the second week to induce colitis. We also examined the dose-dependency of rutin and quercetin (0.01% and 0.001% each) as well as their therapeutic efficacy, which was evaluated following DSS administration, on DSS-induced colitis. The protein level of interleukin (IL)-1 beta in both colonic mucosa and peritoneal macrophages was quantified by enzyme-linked immunosorbent assay. Further, mRNA expression levels of IL-1 beta, tumor necrosis factor-alpha, IL-6, granulocyte macrophage-colony stimulating factor, inducible nitric oxide synthase, and cyclooxygenase (COX)-1 and COX-2 in colonic mucosa were determined by reverse transcription-polymerase chain reaction. A diet containing 0.1% rutin, but not quercetin, attenuated DSS-induced body weight loss and shortening of the colorectum (P<0.01 and <0.05, respectively), and dramatically improved colitis histological scores. Further, DSS-induced increases in colonic mucosal IL-1 beta levels were blunted significantly in rutin-, but not quercetin-, fed mice (P<0.01), while dietary rutin attenuated the expressions of IL-1 beta and IL-6 mRNA in colonic mucosa (each, P<0.01). As for dose dependency, 0.01%, but not 0.001%, dietary rutin significantly reduced mucosal IL-1 beta levels (P<0.01). Notably, a 0.1% rutin diet given 3 days after DSS treatment significantly suppressed both colorectal shortening and IL-1 beta production (P<0.05 and <0.01, respectively). Dietary rutin ameliorates DSS-induced colitis, presumably by suppressing the induction of pro-inflammatory cytokines. Our results suggest that rutin may be useful for the prevention and treatment of IBD and colorectal carcinogenesis via attenuation of pro-inflammatory cytokine production.
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PMID:Dietary rutin, but not its aglycone quercetin, ameliorates dextran sulfate sodium-induced experimental colitis in mice: attenuation of pro-inflammatory gene expression. 1565 31

The organization of the colonic epithelium is directed towards maintaining a continuous layer of cells with functional maturity at the surface, with a constant supply of epithelial cells of sufficient maturity from the crypts. Cells die by shedding at the surface or by undergoing apoptosis in situ, followed by shedding or phagocytosis. The nature of the predominant form of cell death in the normal colon remains uncertain but probably involves more than one route. Death of abnormal cells in the crypt is an important process to prevent clonal expansion and tumour formation. Apoptosis of normal cells is largely secondary to the effects of exposure to luminal factors, such as short-chain fatty adds and surfactants; loss of cell-substratum adhesion (anoikis) in the surface compartment; or cytokine-, oxidant stress- or lymphocyte-mediated death in association with inflammation. In inflammatory bowel disease (IBD) cell death can directly or indirectly compromise barrier function, impair effective epithelial restitution, lead to loss of stem cells and regenerative capacity, and has relevance to carcinogenesis. Therapeutic targeting of cell death in IBD is a double-edged sword--promotion of cell survival may favour more effective healing for active inflammation, while promotion of apoptosis may be protective from carcinogenesis.
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PMID:Apoptosis or necrosis--colonic epithelial cell survival. 1566 39


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