Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The treatment of patients with metastatic colorectal cancer has changed dramatically over recent years. The more optimal use of 5-fluorouracil (5-FU) in association with folinic acid (FA), the development of new drugs such as irinotecan and oxaliplatin and of the oral fluoropyrimidines, capecitabine and UFT, have contributed to increased therapeutic options and to the improved outcome of patients with metastatic colorectal cancer. It is shown that combination therapy with 5-FU/FA and irinotecan or oxaliplatin is more active than 5-FU/FA in the first-line treatment of advanced colorectal cancer. Irinotecan and oxaliplatin are also active in the second-line treatment of colorectal cancer. The oral fluoropyrimidines seem to have an activity comparable to that of intravenous 5-FU/FA in the first-line treatment of metastatic colorectal cancer. New agents acting on novel targets are under development: epidermal growth factor inhibitors, vascular endothelial growth inhibitors, COX-2 inhibitors and farnesyl transferase inhibitors might play a role in the future in the treatment of colon cancer.
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PMID:The treatment of advanced colorectal cancer: where are we now and where do we go? 1196 41

Nonsteroidal anti-inflammatory drugs, which inhibit cyclooxygenase (COX) activity, are powerful antineoplastic agents that exert their antiproliferative and proapoptotic effects on cancer cells by COX-dependent and/or COX-independent pathways. Celecoxib, a COX-2-specific inhibitor, has been shown to reduce the number of adenomatous colorectal polyps in patients with familial adenomatous polyposis. Here, we show that celecoxib induces apoptosis in the colon cancer cell line HT-29 by inhibiting the 3-phosphoinositide-dependent kinase 1 (PDK1) activity. This effect was correlated with inhibition of the phosphorylation of the PDK1 downstream substrate Akt/protein kinase B (PKB) on two regulatory sites, Thr(308) and Ser(473). However, expression of a constitutive active form of Akt/PKB (myristoylated PKB) has a low protective effect toward celecoxib-induced cell death. In contrast, overexpression of constitutive active mutant of PDK1 (PDK1(A280V)) was as potent as the pancaspase inhibitor, benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, to impair celecoxib-induced apoptosis. By contrast, cells expressing a kinase-defective mutant of PDK1 (PDK1(K114G)) remained sensitive to celecoxib. Furthermore, in vitro measurement reveals that celecoxib was a potential inhibitor of PDK1 activity with an IC(50) = 3.5 microm. These data indicate that inhibition of PDK1 signaling is involved in the proapoptotic effect of celecoxib in HT-29 cells.
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PMID:Celecoxib induces apoptosis by inhibiting 3-phosphoinositide-dependent protein kinase-1 activity in the human colon cancer HT-29 cell line. 1200 Jul 50

Statins, anti-hypercholesterolemic agents, have previously been reported to induce apoptosis and exert antitumor activity when combined with other antitumor agents. The potential of lovastatin in combination with highly specific COX-2 inhibitor (MF-tricyclic) to induce anti-proliferative activity against tumour cells was evaluated using the combination index (CI) method. Murine colorectal cancer (colon-26, CMT-93), melanoma (B16F10) and human bladder carcinoma cells (T24) were tested. Exposure of colon-26 and CMT-93 cells resulted in synergistic interactions in both cell lines with CI<1 for 20-80% inhibition of cell growth in both cell lines. This synergy was not observed in the B16F10 melanoma and T24 bladder carcinoma cells. MF-tricyclic (40 microg/ml), augmented lovastatin-induced apoptosis up to 2.5-fold in colon-26 cancer cells. Combination of a specific COX-2 inhibitor, MF-tricyclic, may increase antiproliferative effects of lovastatin in colon cancer cells and this effect was due to an augmented apoptosis.
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PMID:Synergistic interaction between highly specific cyclooxygenase-2 inhibitor, MF-tricyclic and lovastatin in murine colorectal cancer cell lines. 1206 26

Accumulating evidence indicates that COX-2 inhibitors are involved in colon and breast cancer development. Our previous studies indicated that nimesulide and celecoxib, selective COX-2 inhibitors, show inhibitory effects of intestinal carcinogenesis in azoxymethane-treated rats and mice and in Min mice models. We recently found that nimesulide suppressed PhIP-induced breast cancer in female SD rats in which COX-2 protein was overexpressed. These results led us to investigate the effects of prostaglandin E2 (PGE2) in the target tissues. PGE2 showed its biological activity through binding to its membrane receptors, EP(1 to approximately 4). We also investigated the effects of EP receptors on colon carcinogenesis. We used receptor knockout mice and selective receptor antagonists. Our results indicated that the EP1 receptor plays a pivotal role in colon carcinogenesis. Selective EP1 receptor antagonists may be a new class of chemopreventive agents against colon cancer.
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PMID:COX-2 and prostanoid receptors: good targets for chemoprevention. 1208 1

It is well known that about 70% of cancer cases are due to environmental, dietary, or lifestyle factors. Accordingly, these cases maybe avoided by appropriate modifications. In addition, active chemoprevention has become a major interventional approach following the epidemiological observation of a beneficial effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in colon cancer prevention. This is chiefly due to the inhibition of the cyclooxygenase (COX) enzymes. The COX enzymatic system includes two isoenzymes, COX-1 and COX-2, that convert arachidonic acid to prostaglandins. COX-1 is constitutively expressed and synthesizes cytoprotective prostaglandins in the gastrointestinal tract. COX-2 is inducible by the oncogenes ras and scr and other cytokines; it is overexpressed in human cancer cells in which it stimulates cellular division and angiogenesis and inhibits apoptosis. NSAIDs restore apoptosis and decrease tumor mitogenesis and angiogenesis. Most cancer cells have been found to exhibit overexpression of COX-2. Epidemiological studies showed a lower risk of developing cancer of the colon, breast, esophagus, and stomach following the ingestion of NSAIDs. The use of NSAIDs in low dose was associated with a statistically significant decrease in the risk of adenomatous polyps and of overt colon cancer. The regressive effects of sulindac on foci of aberrant crypts in the colon (considered to be precursors of adenoma), and on adenocarcinoma of the colon, are of particular interest because this NSAID does not have an inhibitory effect on COX. This may support the view that the antineoplastic effect of NSAIDs may also be due to a mechanism other than COX-2 inhibition. In breast cancer, large cohort studies reported a 40 to 50% reduced risk of developing cancer, a smaller size of the primary tumor, and a reduction in the number of involved axillary lymph nodes. Similar findings have been reported in the esophagus and stomach, but not in gastric cardia adenocarcinoma. The recent development of selective COX-2 inhibitors resulted in better clinical tolerance than that associated with NSAIDs in general, with the absence of gastrointestinal side effects known to occur after the inhibition of COX-1. Encouraging results have been obtained with these new agents in familial adenomatous polyposis, colon, breast, and prostate cancer.
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PMID:Epidemiological and clinical aspects of nonsteroidal anti-inflammatory drugs and cancer risks. 1208 6

COX-2 overexpression is recognized in various cancers, but the role of COX-2 in the progression of cancer, including the liver metastasis of colon cancer, is not clearly understood. We examined the role of COX-2 in the mechanism of liver metastasis of colon cancer, using a highly metastasizable colon carcinoma cell line, LM-H3. A COX-2 inhibitor, JTE-522, inhibited cell proliferation and invasion of LM-H3 in vitro and clearly reduced the number of metastatic nodules on the surface of nude mouse livers in vivo. We also examined the effects of JTE-522 on the production of growth factors and MMPs through the use of ELISA and gelatin zymography, respectively. JTE-522 downregulated PDGF production by LM-H3 but had no influence on VEGF production. JTE-522 also inhibited MMP-2 secretion by LM-H3. JTE-522 downregulated PGE(2) production, but the associated changes in PGE(2) did not affect PDGF and VEGF production by LM-H3. We conclude that JTE-522 downregulated the cell proliferation and invasive potential of LM-H3 by reducing the production of PDGF and MMP-2 and hypothesize that these inhibitory effects on the production of PDGF and MMP-2 can lead to inhibition of liver metastasis of colon cancer. These data indicate that the COX-2 inhibitor JTE-522 has a high potential for use as a clinical agent for the treatment of liver metastasis of colon cancer.
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PMID:Inhibitory effect of a selective cyclooxygenase-2 inhibitor on liver metastasis of colon cancer. 1212 99

To elucidate early molecular events related to colon carcinogenesis, we examined alterations in the expression of colon cancer-related genes such as cyclooxygenase (COX)-2, APC and c-Myc, cell proliferation and apoptosis in the background colon mucosa, and K-ras mutation at aberrant crypt foci (ACF) in the colons of azoxymethane (AOM)-treated rats 4 weeks after the first exposure to AOM. About 40 ACF/colon were induced in the colons of rats treated with AOM (Group 1); however, rats not treated with AOM (Group 2) showed no ACF formation in the colon. The level of AgNORs in the colonic mucosa was significantly higher in Group 1 than in Group 2 (P<0.01). The colonic mucosa in Group 1 looked macroscopically and histologically normal, but the proliferative activity of the mucosa of rats treated with AOM was clearly elevated. COX-2 mRNA expression was not detected in normal colonic mucosa in Group 2, but 3 out of 10 rats in Group 1 showed COX-2 mRNA expression in their colons by reverse transcription (RT)-polymerase chain reaction (PCR). There was a tendency toward an increased expression level of COX-2 in the AOM-treated group. The level of APC mRNA expression in Group 1 was significantly lower than that in Group 2 (P<0.01). Moreover, the level of c-Myc mRNA expression in Group 1 was significantly higher than that in Group 2 (P<0.01). An average of 0.034+/-0.006% apoptosis in colonic mucosa was detected in Group 1; the incidence of apoptosis in Group 2 was 0.021+/-0.005%. The difference between Groups 1 and 2 was significant (P<0.01). These results indicate that apoptosis was possibly induced to eliminate cells damaged by AOM administration. Six out of 22 (27%) ACF with 4 or more crypts showed K-ras mutations at codon 12; all mutations were G to A transitions (GGT to GAT). ACF with 1-3 crypts showed no mutations in the K-ras gene. In conclusion, AOM caused an increase in COX-2 and c-Myc mRNA expression, a decrease in APC mRNA expression, induction of apoptosis in normal-appearing colonic mucosa, and a K-ras mutation in ACF with 4 or more crypts. These findings may help to identify key targets in the early steps of colon carcinogenesis, against which drugs that would be broadly effective for chemoprevention of colon cancer could be developed.
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PMID:Molecular changes in the early stage of colon carcinogenesis in rats treated with azoxymethane. 1214 79

Regular use of non-steroidal anti-inflammatory drugs (NSAIDs) seems to reduce the progression of several diseases, including colon cancer, lung cancer, breast cancer and Alzheimer disease (AD). Several studies have shown that NSAIDs can modulate cell cycle progression, especially in the G0/G1 phase. The main target of most NSAIDs is the enzyme cyclo-oxygenase (COX), which occurs in 2 isoforms, COX-1 and COX-2. In AD and non-demented control brain, COX-2 is expressed in neuronal cells. In this study the expression of COX-2, cyclin D1, and cyclin E was investigated at the immunohistochemical level in AD and non-demented control temporal cortex. COX-2, cyclin D1, and cyclin E expression was detected in pyramidal neurons in both AD and control patients. The number of COX-2-immunoreactive neurons positively correlated with the number of cyclin E- and cyclin D1-immunoreactive neurons. Moreover, immunostaining of sequential tissue sections and double immunofluorescence labeling revealed co-expression of COX-2 and cyclin D1 and E in neuronal cells. In addition, an inverse correlation was observed between the neuronal expression of COX-2 and cyclin E and the Braak score for amyloid beta deposits. Our findings suggest a relationship between the neuronal expression of COX-2 and cell cycle markers, which may be involved early in AD pathology.
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PMID:Cyclin D1 and cyclin E are co-localized with cyclo-oxygenase 2 (COX-2) in pyramidal neurons in Alzheimer disease temporal cortex. 1215 83

Chronic uncontrolled pain may be the greatest health care crisis facing the United States. It is the major symptom for which patients seek medical care and is associated with substantial economic and psychosocial costs. For many patients, particularly the elderly and those suffering from cancer, chronic pain is often undertreated. Because pain has an emotional component and is frequently accompanied by depression and/or anxiety, patients benefit from a comprehensive assessment and multidisciplinary approach to treatment. It is likely that coxibs (cyclooxygenase or COX-2-selective inhibitors) will assume an increasingly prominent role in the treatment of chronic pain associated with arthritis, cancer, and other diseases either as monotherapy or in combination with other drugs. In addition, the role of COX-2 inhibition in the prevention and treatment of colon cancer, Alzheimer's disease (AD), and other chronic health problems is an area currently undergoing intense investigation.
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PMID:Pain management and beyond: evolving concepts and treatments involving cyclooxygenase inhibition. 1220 82

Cyclooxygenase (COX) enzyme expression is elevated in human and rodent lung tumors, and non-steroidal anti-inflammatory drugs (NSAIDs) such as indomethacin reduce lung tumor formation in mice. These observations, along with the well-characterized protection that NSAID treatment engenders for colon cancer, have prompted clinical trials testing whether celecoxib, a COX-2-specific inhibitor, can prevent lung cancer development in populations at high risk. Protection by celecoxib in murine models of pulmonary inflammation and lung tumorigenesis has not yet been evaluated, however, and we now report such studies. Chronic administration of butylated hydroxytoluene (BHT) to mice stimulates pulmonary inflammation characterized by vascular leakage and macrophage infiltration into the air spaces, increased PGE2 production, and translocation of 5-lipoxygenase (5-LO) from the cytosol to the particulate fraction. Dietary celecoxib limited macrophage infiltration, abrogated PGE2 production and reduced particulate 5-LO content. Celecoxib and aspirin were ineffective at preventing lung tumorigenesis in a two-stage carcinogenesis protocol in which 3-methylcholanthrene administration is followed by chronic BHT. Celecoxib also did not reduce the multiplicity of lung tumors after induction by urethane; lung tumors in celecoxib-treated mice were larger than those in mice that did not receive celecoxib. Tumors induced in celecoxib-fed mice contained 60% less PGE2 than tumors in mice fed control diets, so reducing lung PGE2 levels was insufficient to prevent lung tumor formation. As the production of eicosanoids in addition to PGE2 is also inhibited by celecoxib, and as celecoxib has COX-independent interactions, its effects on tumor formation may vary in different organ systems.
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PMID:Celecoxib reduces pulmonary inflammation but not lung tumorigenesis in mice. 1237 74


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