Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A loss-of-function mutation in the APC gene initiates colorectal carcinogenesis. Although the molecular mechanism of tumor initiation is complex, several modifier genes have been identified using mouse models, including the ApcMin mouse. Among the familial adenomatous polyposis mouse lines carrying a truncation mutation at codon 580 in Apc (Apc580D), one line (line19-Apc(580D/+)) showed a remarkably reduced incidence of intestinal adenomas (<5% compared with other lines). Extensive genetic analysis identified a deletion in the alpha-catenin (Ctnna1) gene as the cause of this suppression. Notably, the suppression only occurred when the Ctnna1 deletion was in cis-configuration with the Apc580D mutation. In all adenomas generated in line19-Apc(580D/+), somatic recombination between the Apc and Ctnna1 loci retained the wild-type Ctnna1 allele. These data strongly indicate that simultaneous inactivation of alpha-catenin and Apc during tumor initiation suppresses adenoma formation in line19-Apc(580D/+), suggesting that alpha-catenin plays an essential role in the initiation of intestinal adenomas. Although accumulating evidence obtained from human colon tumors with invasive or metastatic potential has established a tumor-suppressive role for alpha-catenin in late-stage tumorigenesis, the role of alpha-catenin in the initiation of intestinal tumorigenesis is not well documented, especially compared with that of beta-catenin. A mouse model used in this study focused on the early stage of tumor initiation and clearly indicated an essential role for alpha-catenin. Thus, alpha-catenin has dual roles in intestinal tumorigenesis, a supporting role in tumor initiation, and a suppressive role in tumor progression.
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PMID:Alpha-catenin is essential in intestinal adenoma formation. 1798 30

APC-germline mutation creates predisposition for intestinal tumorigenesis. APCMin/+ mice, developing tumors preferentially in the small intestine and only minimally in the colon, were fed pectin-enriched diets (10% galacturonan; degree of methoxylation=37.0 and 70.4%) or standard diet. Pectins used in the present study do not inhibit intestinal tumorigenesis and rather accelerate it in APCMin/+ mice. Both pectins exhibited prebiotic effects associated with high fermentative formation of acetate but producing low butyrate. The differences of the short-chain fatty acid concentrations between cecum and colon and those between colon and feces were larger than expected and increased with cancer progression, indicating an inhibition of butyrate absorption. Pectins transported more bile acids toward the colon than the standard diet and caused a higher generation of secondary bile acids despite lower pH values. Overexpression of COX-2 resulted in lower antioxidative capacity, thus promoting cancer. Apoptosis increased in hyperplasia but decreased in late adenomas. When biological modular design principles are taken into consideration, it can be expected that pectin also reinforces colorectal tumorigenesis of patients suffering from APC gene defects.
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PMID:Pectin does not inhibit intestinal carcinogenesis in APC-deficient Min/+ mice. 1819 30

Mast cells have been observed in numerous types of tumors; however, their role in carcinogenesis remains poorly understood. The majority of epidemiological evidence suggests a negative association between the presence of mast cells and tumor progression in breast, lung and colonic neoplasms. Intestinal adenomas in the multiple intestinal neoplasia (Min, APC(Min/+)) mouse displayed increased numbers of mast cells and increased abundance of mast cell-associated proteinases as determined by transcriptional profiling with the Hu/Mu ProtIn microarray. To examine the role of mast cells in intestinal tumorigenesis, a mutant mouse line deficient in mast cells, Sash mice (c-kit(W-sh/W-sh)), was crossed with the Min mouse, a genetic model of intestinal neoplasia. The resulting mast cell-deficient Min-Sash mice developed 50% more adenomas than littermate controls and the tumors were 33% larger in Min-Sash mice. Mast cell deficiency did not affect tumor cell proliferation; however, apoptosis was significantly inhibited in mast cell-deficient mice. Mast cells have been shown to act as critical upstream regulators of numerous inflammatory cells. Neutrophil, macrophage and T cell populations were similar between Min and Min-Sash mice; however, eosinophils were significantly less abundant in tumors obtained from Min-Sash animals. These results indicate a protective, antitumor role of mast cells in a genetic model of early-stage intestinal tumorigenesis.
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PMID:A protective role of mast cells in intestinal tumorigenesis. 1825 1

Standard systemic treatment of prostate cancer today is comprised of antihormonal and cytostatic agents. Vaccine therapy of prostate cancer is principally attractive because of the presence of tumor-associated antigens such as prostate-specific antigen (PSA), prostatic acid phosphatase (PAP), prostate-specific membrane antigen (PSMA), and others. Most prostate cancer vaccine trials have demonstrated some activation of the immune system, limited clinical success, and few adverse effects.One strategy to overcome the problem of limited clinical success of vaccine therapies in prostate cancer could be strict patient selection. The clinical course of patients with prostate cancer (even in those with PSA relapse following surgery or radiotherapy with curative intention, or those with metastatic disease) can vary significantly. In patients with organ-confined prostate cancer, the most promising immunotherapeutic approach would be an adjuvant therapy following surgery or radiotherapy. Patients with PSA relapse following surgery or radiotherapy could also benefit from immunotherapy because tumor burden is usually low. However, most patients in prostate cancer vaccine trials had metastatic hormone-refractory prostate cancer (HRPC). High tumor burden correlates with immune escape phenomena. Nevertheless, 2 years ago, it was demonstrated, for the first time, that a tumor vaccine can prolong survival compared with placebo in patients with HRPC. This was demonstrated with the vaccine sipuleucel-T (APC-8015; Provenge), a mixture of cells obtained from the patient's peripheral blood by leukapheresis followed by density centrifugation and exposition. The Biologics License Application for this vaccine was denied by the US FDA in mid 2007, however, because the trial had failed to reach the primary endpoint (prolongation of time to tumor progression). Nevertheless, clinical trials with sipuleucel-T are ongoing, and the approach still looks promising. Another interesting approach is a vaccine made from whole tumor cells: GVAX. This vaccine is presently being studied in phase III trials against, and in combination with, docetaxel. The results from these trials will become available in the near future. Besides the precise definition of the disease status of patients with prostate cancer, combinations of vaccine therapy with radiotherapy, chemotherapy, and/or hormonal therapy are approaches that look promising and deserve further investigation.
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PMID:Prostate cancer vaccines: current status and future potential. 1834 5

A relatively new view of colorectal cancer is that its development/progression reflects the contribution of a large set of altered gene products in varying combinations, each providing a "fitness advantage." In searching for novel contributing gene products using Unigene cluster data mining, we found overrepresentation of expressed sequence tags corresponding to a previously uncharacterized gene (ZKSCAN3) in colorectal tumors. ZKSCAN3 was pursued for several reasons: (a) its sequence similarity with bowl required for Drosophila hindgut development; (b) it lies in a chromosomal region (6p22.1) amplified in colorectal cancer; and (c) its coding sequence predicts tandem C(2)H(2) zinc finger domains present in a class of proteins gaining attention for their role in oncogenesis/tumor progression. Reverse transcription-PCR confirmed overexpression in colorectal tumor tissue compared with adjacent nonmalignant mucosa due in part to gene amplification determined by Southern blotting. Further, immunohistochemistry with an antibody generated to the predicted protein sequence revealed higher ZKSCAN3 expression in invasive compared with noninvasive tumors. Intriguingly, the ZKSCAN3 protein was also expressed in tumors wild-type for genes (APC, p53, K-Ras) commonly targeted in colorectal cancer. ZKSCAN3 knockdown in two independent colon cancer cell lines impaired anchorage-independent growth and orthotopic tumor growth, whereas overexpression in a third cell line had the opposite effect and increased 5-fluorouracil resistance. Liposomal delivery of a ZKSCAN3-targeting small interfering RNA reduced tumorigenicity of orthotopic colon cancer. Thus, the hitherto uncharacterized ZKSCAN3 adds to an expanding set of encoded products contributing to the progression of colorectal cancer.
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PMID:The previously undescribed ZKSCAN3 (ZNF306) is a novel "driver" of colorectal cancer progression. 1851 92

The forkhead box M1 (FoxM1) transcription factor is overexpressed in many cancers, and in mouse models it is required for tumor progression. FoxM1 activates expression of the cell cycle genes required for both S and M phase progression. Here we demonstrate that FoxM1 is degraded in late mitosis and early G(1) phase by the anaphase-promoting complex/cyclosome (APC/C) E3 ubiquitin ligase. FoxM1 interacts with the APC/C complex and its adaptor, Cdh1. Expression of Cdh1 stimulated degradation of the FoxM1 protein, and depletion of Cdh1 resulted in stabilization of the FoxM1 protein in late mitosis and in early G(1) phase of the cell cycle. Cdh1 has been implicated in regulating S phase entry. We show that codepletion of FoxM1 inhibits early S phase entry observed in Cdh1-depleted cells. The N-terminal region of FoxM1 contains both destruction box (D box) and KEN box sequences that are required for targeting by Cdh1. Mutation of either the D box sequence or the KEN box sequence stabilized FoxM1 and blocked Cdh1-induced proteolysis. Cells expressing a nondegradable form of FoxM1 entered S phase rapidly following release from M phase arrest. Together, our observations show that FoxM1 is one of the targets of Cdh1 in late M or early G(1) phase and that its proteolysis is important for regulated entry into S phase.
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PMID:Anaphase-promoting complex/cyclosome-CDH1-mediated proteolysis of the forkhead box M1 transcription factor is critical for regulated entry into S phase. 1857 89

Desmoid tumors (desmoid-type fibromatoses) are locally aggressive soft tissue tumors associated with the Wnt/beta-catenin signaling pathway (APC-beta-catenin-Tcf pathway). Matrix metalloproteinase-7, which is one of the target genes of the Wnt/beta-catenin signaling pathway, has been reported to play an important role in tumor progression. We examined the immunohistochemical expression of beta-catenin and matrix metalloproteinase-7 in 72 samples (63 primary and 9 recurrent samples, 63 patients) of sporadic desmoid tumors without familial adenomatous polyposis, and the genetic alteration of the beta-catenin gene in 33 frozen materials (22 primary and 11 recurrent samples, 22 patients). We further examined messenger RNA expression of matrix metalloproteinase 7 by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and compared the results with those of normal skeletal muscles. Immunohistochemically, there was a statistically significant correlation between widespread nuclear expression of beta-catenin and overexpression of matrix metalloproteinase-7 (P < .01 in extra-abdominal desmoid, Fisher test). There were 7 missense point mutations in the 22 primary frozen samples (32%). In the beta-catenin mutated group, matrix metalloproteinase-7 messenger RNA expression was significantly higher than that of the beta-catenin wild-type group (P = .0018, Mann-Whitney U test). Our results suggest that the matrix metalloproteinase-7 gene may be up-regulated by mutated or continuously elevated beta-catenin protein and that the matrix metalloproteinase-7 gene may also be targeted in the Wnt/beta-catenin signaling pathway in sporadic desmoid tumors.
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PMID:Correlation between beta-catenin widespread nuclear expression and matrix metalloproteinase-7 overexpression in sporadic desmoid tumors. 1871 18

Matrix metalloproteinases (MMPs) are extracellular proteolytic enzymes involved in tumor progression. We present the in vivo detection and quantitation of MMP7 activity using a specific near-infrared polymer-based proteolytic beacon, PB-M7NIR. PB-M7NIR is a pegylated polyamidoamine PAMAM-Generation 4 dendrimer core covalently coupled to a Cy5.5-labeled peptide representing a selective substrate that monitors MMP7 activity (sensor) and AF750 as an internal reference to monitor relative substrate concentration (reference). In vivo imaging of tumors expressing MMP7 had a median sensor to reference ratio 2.2-fold higher than a that of a bilateral control tumor. Ex vivo imaging of intestines of multiple intestinal neoplasia (APC Min) mice injected systemically with PB-M7NIR revealed a sixfold increase in the sensor to reference ratio in the adenomas of APC Min mice compared with control intestinal tissue or adenomas from MMP7-null Min mice. PB-M7NIR detected tumor sizes as small as 0.01 cm2, and the sensor to reference ratio was independent of tumor size. Histologic sectioning of xenograft tumors localized the proteolytic signal to the extracellular matrix; MMP7-overexpressing tumors displayed an approximately 300-fold enhancement in the sensor to reference ratio compared with nonexpressing tumor cells. In APC Min adenomas, the proteolytic signal colocalized with the endogenously expressed MMP7 protein, with sensor to reference ratios approximately sixfold greater than that of normal intestinal epithelium. PB-M7NIR provides a useful reagent for the in vivo and ex vivo quantitation and localization of MMP-selective proteolytic activity.
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PMID:Optical imaging of matrix metalloproteinase-7 activity in vivo using a proteolytic nanobeacon. 1912 82

Prostaglandin E(2) (PGE(2)) promotes cancer progression by affecting cell proliferation, apoptosis, angiogenesis, and the immune response. It has been reported that PGE(2) is transported or passes through the cell membrane via prostaglandin-specific transporters including the prostaglandin transporter (PGT, an influx transporter) and the multidrug resistance-associated protein 4 (an efflux transporter). PGT can facilitate the removal of PGE(2) from the extracellular milieu by transporting it into the cell, where 15-hydroxyprostaglandin dehydrogenase (15-PGDH) then oxidizes PGE(2) into 15-keto PGE(2). We previously reported that 15-PGDH expression is reduced in most colorectal cancers, indicating the tumor suppressor role of this gene. In the present study, we show that PGT expression is also decreased (whereas multidrug resistance-associated protein 4 expression is elevated) in human colorectal cancer specimens (compared with expression in normal mucosa) and in colorectal cancer cell lines. Furthermore, we found that PGT expression decreased in premalignant adenomas in APC(min) mice and was partially restored (in human colorectal cancer cell lines) by treatment with a DNA demethylating agent or histone deacetylase inhibitor. Forced PGT overexpression in vitro dose dependently reduced extracellular PGE(2) levels and increased intracellular levels of its catabolic product 15-keto PGE(2). Our collective data suggest that the existing model to explain increased PGE(2) in colorectal neoplasia should be modified to include the novel mechanism of coordinated up- and down-regulation of genes involved in PGE(2) transport.
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PMID:Regulation of prostaglandin transporters in colorectal neoplasia. 1913 38

Blood coagulation appears to play an important role in the occurrence of cancer and its effects may be twofold. First, in patients with cancer, blood coagulation is activated in the direction of a prothrombotic state. Second, a procoagulant environment may promote cancer in different ways. In this chapter we discuss some of the mechanisms that may be involved in this interplay between coagulation and cancer. Blood coagulation proteins interact with cells in the vasculature to maintain hemostasis. However, many proteins that are involved in coagulation and anticoagulation, as well as fibrinolysis, are also found in extravascular tissues. In different organs, these proteins may be involved in cell-signaling mechanisms, through interaction with cell receptors like protease-activated receptors (PARs). Such interactions may drive inflammation, angiogenesis and cell proliferation. The potential procarcinogenic actions of proteases like thrombin may be counteracted by the anticoagulant and anti-inflammatory actions of the protein C-thrombomodulin mechanism. In the blood of cancer patients, the balance is usually shifted towards a procoagulant direction. The resulting excess thrombin- and fibrin-forming activity promotes venous thrombosis and may in the extravascular compartment stimulate cancer progression. The activation of platelets and their interaction with leukocytes may propagate this process. In addition to the therapeutic modulation of the prothrombotic environment, the induction of specific anticoagulant proteins including thrombomodulin may have effects on tumor growth or dissemination, but the nature of these effects still remains hard to predict. The interplay between cancer and blood coagulation merits further experimental and clinical research.
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PMID:Overview of the postulated mechanisms linking cancer and thrombosis. 1917 85


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