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Query: UMLS:C0699790 (
colon cancer
)
28,837
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Among patients with colorectal cancer (CRC) diagnosed in the United States, 37.2% are diagnosed with stage III and 27.9% with stage II disease. In locoregionally advanced CRC, surgery is the primary treatment modality and has a curative intent. The survival depends on the pathologic stage and varies from 30%-60% for stage III to 60%-80% for stage II. However, as much as 40%-50% of patients will relapse and require additional treatment of the disease. Clinical failure after resection of CRC is predominantly secondary to the clinical progression of previously undetected distant metastatic disease. Until very recently, the absolute benefit for survival obtained with adjuvant therapy compared with control was about 6%. Introduction of oxaliplatin in the adjuvant setting has shown a reduction of 23% in the risk of relapse when compared with 5-fluorouracil alone (MOSAIC). Recent phase III studies have shown that targeted agents improved survival in patients with advanced-stage CRC. Bevacizumab, a monoclonal antibody targeting
vascular endothelial growth factor
, is the first antiangiogenic drug to show improved efficacy when used in combination with irinotecan and oxaliplatin for first- and second-line treatment of CRC. Cetuximab, another monoclonal antibody targeting epidermal growth factor receptor, has shown efficacy in third-line therapy and promising results in first-line phase II studies. There is great interest in whether the biologic agents bevacizumab and cetuximab can improve survival in the adjuvant-therapy setting. This article reviews the adjuvant therapy for
colon cancer
and discusses the potential role and current trials involving the targeted agents.
...
PMID:Targeted agents for adjuvant therapy of colon cancer. 1679 91
EGCG [(-)epigallocatechin-3-gallate], a green tea-derived polyphenol, has been shown to suppress cancer cell proliferation, and interfere with the several signaling pathways and induce apoptosis. Practically, there is emerging evidence that EGCG has a potential to increase the efficacy of chemotherapy in patients. We hypothesized that EGCG may exert cell cytotoxicity through modulating AMPK (AMP-activated protein kinase) followed by the decrease in COX-2 expression. EGCG treatment to
colon cancer
cells resulted in a strong activation of AMPK and an inhibition of COX-2 expression. The decreased COX-2 expression as well as prostaglandin E(2) secretion by EGCG was completely abolished by inhibiting AMPK by an AMPK inhibitor, Compound C. Also, the activation of AMPK was accompanied with the reduction of VEGF (
vascular endothelial growth factor
) and glucose transporter, Glut-1 in EGCG-treated cancer cells. These findings support the regulatory role of AMPK in COX-2 expression in EGCG-treated cancer cells. Furthermore, we have found that reactive oxygen species (ROS) is an upstream signal of AMPK, and the combined treatment of EGCG and chemotherapeutic agents, 5-FU or Etoposide, exert a novel therapeutic effect on chemo-resistant
colon cancer
cells. AMPK, a molecule of newly defined cancer target, was shown to control COX-2 in EGCG-treated
colon cancer
cells.
...
PMID:Apoptotic effect of EGCG in HT-29 colon cancer cells via AMPK signal pathway. 1679 20
We recently showed by DNA microarray analysis that vascular endothelial growth factor (VEGF) receptor (VEGFR) is expressed in HCT8/S11 human
colon cancer
cells, suggesting that several angiogenic factors may target
colon cancer
cells themselves. In this study, transcripts encoding the
VEGF
-165 and semaphorin 3A (Sema3A) receptors and coreceptors Flt-1, KDR/Flk-1, plexin A1, and neuropilins NP-1 and NP-2 were identified by reverse transcription-PCR in the human
colon cancer
cell lines HCT8/S11, HT29, HCT116, and PCmsrc. Collagen invasion induced by
VEGF
-165 and Sema3A in HCT8/S11 cells (EC(50), 0.4-1 nmol/L) required p42/44 mitogen-activated protein kinase and signaling through RhoA/Rho-kinase-dependent and -independent pathways, respectively. As expected, the VEGFR signaling inhibitor ZD4190 selectively abrogated the proinvasive activity of
VEGF
in collagen gels (IC(50), 10 nmol/L) and chick heart fragments. We identify a novel function for
VEGF
-165 and Sema3A as proinvasive factors for human colorectal cancer cells. Interestingly, oral administration of the single drug ZD4190 to athymic mice (50 mg/kg/d, once daily) inhibited by 70% the growth of HCT8/S11 tumor cell xenografts. Combinations between the src tyrosine kinase inhibitor M475271 and ZD4190 or cisplatin resulted in additive therapeutic activity against LNM35 human lung tumor xenografts. Our data have significant implications for new therapeutic approaches and individualized treatment targeting VEGFR and src signaling pathways in combination with established clinical drugs at primary tumors and distant metastases in colon and lung cancer patients.
...
PMID:Inhibition of vascular endothelial growth factor (VEGF)-165 and semaphorin 3A-mediated cellular invasion and tumor growth by the VEGF signaling inhibitor ZD4190 in human colon cancer cells and xenografts. 1692 28
7-Ethyl-10-hydroxy-camptothecin (SN-38), a biological active metabolite of irinotecan hydrochloride (CPT-11), has potent antitumor activity but has not been used clinically because it is a water-insoluble drug. For delivery by i.v. injection, we have successfully developed NK012, a SN-38-releasing nanodevice. The purpose of this study is to investigate the pharmacologic character of NK012 as an anticancer agent, especially in a
vascular endothelial growth factor
(
VEGF
)-secreting tumor model. The particle size of NK012 was approximately 20 nm with a narrow size distribution. NK012 exhibited a much higher cytotoxic effect against lung and
colon cancer
cell lines as compared with CPT-11. NK012 showed significantly potent antitumor activity against a human colorectal cancer HT-29 xenograft as compared with CPT-11. Enhanced and prolonged distribution of free SN-38 in the tumor was observed after the injection of NK012. NK012 also had significant antitumor activity against bulky SBC-3/Neo (1,533.1 +/- 1,204.7 mm(3)) and SBC-3/
VEGF
tumors (1,620.7 +/- 834.0 mm(3)) compared with CPT-11. Furthermore, NK012 eradicated bulky SBC-3/
VEGF
tumors in all mice but did not eradicate SBC-3/Neo tumors. In the drug distribution analysis, an increased accumulation of SN-38 in SBC-3/
VEGF
tumors was observed as compared with that in SBC-3/Neo tumors. NK012 markedly enhanced the antitumor activity of SN-38, especially in highly
VEGF
-secreting tumors, and could be a promising SN-38-based formulation.
...
PMID:Novel SN-38-incorporating polymeric micelles, NK012, eradicate vascular endothelial growth factor-secreting bulky tumors. 1704 68
n-3 Polyunsaturated fatty acids have been shown to powerfully inhibit the growth of
colon cancer
cells, mainly acting as pro-apoptotic agents through inhibition of cycloxygenase-2 (COX-2) expression. Since dysregulation of beta-catenin expression is frequently found at early stage of colorectal carcinogenesis, we analyzed whether docosahexaenoic acid (DHA) may modify the expression of beta-catenin in
colon cancer
cells (SW480 and HCT116) over-expressing this protein, but lacking COX-2. Futhermore, we investigated if alterations in beta-catenin expression may be associated with apoptosis induction. Treatment of cells with increasing concentrations of DHA induced a dose- and time-dependent inhibition of beta-catenin protein expression which, however, was not accompanied by modifications in beta-catenin transcription. Conversely, the proteasomal inhibitors MG132 and lactacystin prevented DHA-induced beta-catenin decrease, suggesting that DHA may regulate the proteasomal degradation of beta-catenin. The reduced levels of beta-catenin were accompanied by decreased translocation of beta-catenin into the nucleus, where it acts as a transcription factor in concert with T-Cell Factor (TCF). DHA, at the same range of concentrations, was also able to induce apoptosis by a caspase-3-dependent mechanism and to cause a dose- and time-dependent decrease of survivin, an apoptosis inhibitor undetectable in normal tissues and expressed in colorectal cancer through TCF-beta-catenin stimulation. Several other proteins regulated by the TCF-beta-catenin pathway and involved in regulation of tumor growth were down-regulated by DHA, including peroxisome proliferator-activated receptor-delta, membrane type 1 (MT1)-matrix metalloproteinase (MMP), MMP-7 and
vascular endothelial growth factor
. The present study, thus, raises the possibility that DHA may exert pro-apoptotic and antitumoral effects through proteasomal regulation of beta-catenin levels and alterations in the expression of TCF-beta-catenin target genes.
...
PMID:Docosahexaenoic acid induces proteasome-dependent degradation of beta-catenin, down-regulation of survivin and apoptosis in human colorectal cancer cells not expressing COX-2. 1718 61
The interplay between malignant and stromal cells is essential in tumorigenesis. We have previously shown that colony-stimulating factor (CSF)-1, matrix metalloprotease (MMP)-2, and
vascular endothelial growth factor
(
VEGF
)-A production by stromal cells is enhanced by CSF-1-negative SW620
colon cancer
cells. In the present study, the mechanisms by which
colon cancer
cells up-regulate host factors to promote tumorigenesis were investigated. Profiling of tumor cell cytokine expression in SW620 tumor xenografts in nude mice showed increased human tumor necrosis factor (TNF)-alpha mRNA expression with tumor growth. Incubation of macrophages with small interfering (si) RNAs directed against TNF-alpha or TNF-alpha-depleted SW620 cell conditioned medium versus SW620 cell conditioned medium failed to support mouse macrophage proliferation, migration, and expression of CSF-1,
VEGF-A
, and MMP-2 mRNAs. Consistent with these results, human TNF-alpha gene silencing decreased mouse macrophage TNF-alpha, CSF-1, MMP-2, and
VEGF-A
mRNA expression in macrophages cocultured with human cancer cells. In addition, inhibition of human TNF-alpha or mouse CSF-1 expression by siRNA reduced tumor growth in SW620 tumor xenografts in mice. These results suggest that
colon cancer
cell-derived TNF-alpha stimulates TNF-alpha and CSF-1 production by macrophages, and that CSF-1, in turn, induces macrophage
VEGF-A
and MMP-2 in an autocrine manner. Thus, interrupting tumor cell-macrophage communication by targeting TNF-alpha may provide an alternative therapeutic approach for the treatment of
colon cancer
.
...
PMID:Colon cancer cell-derived tumor necrosis factor-alpha mediates the tumor growth-promoting response in macrophages by up-regulating the colony-stimulating factor-1 pathway. 1728 36
Experimental data suggest therapeutic advantage from selective disruption of the hypoxia response. We recently found that the proteasome inhibitor bortezomib decreases tumor carbonic anhydrase IX (CAIX) expression in
colon cancer
patients and herein report a companion laboratory study to test if this effect was the result of hypoxia-inducible factor (HIF) inhibition. Human cervical (SiHa and Me180) and colon (RKO) carcinoma cell lines were treated with bortezomib or the structurally unrelated proteasome inhibitor MG132 in normoxic and hypoxic conditions in vitro. Two different in vivo experiments investigated bortezomib effects after single dose (2 mg/kg, 24 h) or longer exposure in severe combined immunodeficient mice bearing SiHa xenografts. Treatment with either drug produced accumulation of HIF-1alpha in vitro but strongly inhibited the production of CAIX and
vascular endothelial growth factor
(
VEGF
) under hypoxia. This correlated with more than 10-fold reduction in HIF-1 transcriptional activity under hypoxic conditions. A similar effect of bortezomib was seen in vivo, using the nitroimidazole probe EF5 to define regions of tumor hypoxia and a triple immunofluorescence technique to measure the spatial distributions of HIF-1alpha and CAIX. Plasma
VEGF
levels decreased by approximately 90% during treatment with bortezomib, indicating that this agent can potently inhibit the hypoxia response in tumors.
...
PMID:Suppression of the hypoxia-inducible factor-1 response in cervical carcinoma xenografts by proteasome inhibitors. 1730 15
Antibody-based therapeutic approaches have had a significant impact in the treatment of non-Hodgkin's lymphoma (NHL). Rituximab's development as an anti-CD20 antibody heralded a new era in treatment approaches for NHL. While rituximab was first shown to be effective in the treatment of relapsed follicular lymphoma, it is now standard monotherapy for front-line treatment of follicular lymphoma, and is also used in conjunction with chemotherapy for other indolent, intermediate and aggressive B-cell lymphomas. The development of rituximab has led to intense interest in this type of therapeutic approach and to development and approval of the radioimmunoconjugates of rituximab, (90)Y-ibritumomab tiuxetan and (131)I-tositumomab, which have added to the repertoire of treatments for relapsed follicular lymphoma and increased interest in developing other conjugated antibodies. Since rituximab is a chimeric antibody, there is a need to develop fully humanised antibodies, such as IMMU-106 (hA20), in order to minimise infusion reactions and eliminate the development of human antibodies against the drug. Further clinical evaluation of antibodies has been based largely on our knowledge of antigen expression on the surface of lymphoma cells and has led to the development of antibodies against CD22 (unconjugated epratuzumab and calicheamicin conjugated CMC-544 [inotuzumab ozogamicin]), CD80 (galiximab), CD52 (alemtuzumab), CD2 (MEDI-507 [siplizumab]), CD30 (SGN-30 and MDX-060 [iratumumab]), and CD40 (SGN-40). Furthermore, the VEGF (
vascular endothelial growth factor
) inhibitor bevacizumab, which was first approved for the treatment of
colon cancer
is currently under investigation in NHL, and agonists rather than antibodies to TRAIL (tumour necrosis factor-related apoptosis-inducing ligand) [rApo2L/TRAIL, HGS-ETR1{mapatumumab}, HGS-ETR2] are currently being investigated as treatments for both advanced solid tumours and NHL. Knowledge of the ability of cancer cells to become resistant to a targeted therapy by activating an alternative pathway to evade apoptosis has driven studies that combine antibodies such as epratuzumab plus rituximab (ER) or ER plus chemotherapy with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) [ER-CHOP], inotuzumab ozogamicin plus rituximab, alemtuzumab plus CHOP (CHOP-C), bevacizumab plus rituximab, and now the combination of rApo2L/TRAIL plus rituximab. As a result of the expansion of research in this area, several treatment-specific adverse effects have been noted, including infusion-related reactions for rituximab, myelosuppression secondary to (90)Y-ibritumomab tiuxetan and (131)I-tositumomab, and immunosuppression leading to infectious complications for alemtuzumab. Also, soluble forms of the antigens (sCD30) are now being investigated as potential mechanisms of resistance to antibody treatments by binding the antibody before the drug can bind to the lymphoma cell. In addition, it has also become apparent that these antibodies often have a dose-dependent half-life (rituximab) or long half-lives of up to 2-3 weeks (epratuzumab and galiximab) with a consequent delay to a response, thus influencing how long we should wait for a response before declaring an antibody to be ineffective. Antibody-based therapeutic approaches have already had a profound impact on the treatment of NHL, and it is almost certain that, as their clinical development progresses, we will continue to refine the optimum methods of incorporating these drugs in NHL treatment in order to offer our patients the best clinical benefits.
...
PMID:Monoclonal antibodies in the treatment of non-Hodgkin's lymphoma. 1733 94
Cigarette smoking is a putative environmental risk factor for
colon cancer
. Nicotine, an active alkaloid in tobacco, has been implicated in carcinogenesis. In the present study, we demonstrated that oral nicotine administration (50 or 200 microg/ml) for 25 days stimulated growth of human
colon cancer
xenograft in nude mice. It also increased vascularization in the tumors and elevated cotinine and adrenaline plasma levels. beta-Adrenoceptors, cyclooxygenase-2 (COX-2), prostaglandin E(2) (PGE(2)), and
vascular endothelial growth factor
(
VEGF
) in tumor tissues were also increased by nicotine. I.p. injection of beta(1)-selective antagonist (atenolol, 5 or 10 mg/kg) or beta(2)-selective antagonist (ICI 118,551, 5, or 10 mg/kg) blocked the nicotine-stimulated tumor growth dose dependently, in which beta(2)-selective antagonist produced a more prominent effect. beta-Adrenoceptors blockade also abrogated the stimulatory action of nicotine on microvessel densities as well as cell expression of COX-2, PGE(2), and
VEGF
, in which beta(2)-selective antagonist produced a significant effect. These findings provide a direct evidence that nicotine can enhance colon tumor growth mediated partly by stimulation of beta-adrenoceptors, preferentially the beta(2)-adrenoceptors. Activation of beta-adrenoceptors and the subsequent stimulation of COX-2, PGE(2), and
VEGF
expression is perhaps an important mechanism in the tumorigenic action of nicotine on colon tumor growth. These data suggest that beta-adrenoceptors play a modulatory role in the development of
colon cancer
and partly elucidate the carcinogenic action of cigarette smoke.
...
PMID:Nicotine promotes colon tumor growth and angiogenesis through beta-adrenergic activation. 1736 3
PGE(2) has been shown to exert pro-oncogenic effects in colorectal neoplasia through producing autocrine or paracrine growth factors. In the present study, we demonstrate that PGE(2) induced the expression of IL-1alpha in
colon cancer
cells, which plays critical roles in tumor metastasis and neoangiogenesis in a variety of cancers. PGE(2) increased the levels of both IL-1alpha mRNA and protein, suggesting a positive feedback loop between the IL-1 pathway and PGE(2) signaling. Mechanistically, PGE(2) induced the expression of IL-1alpha at both transcriptional and posttranscriptional levels. PGE(2) stimulated the transcriptional activity of the IL-1alpha promoter and significantly stabilized IL-1alpha mRNA. Moreover, we show that IL-1alpha enhanced colorectal neoplasia, stimulating cell migration and neoangiogenesis. Knockdown of the expression of IL-1alpha by small-interfering RNA resulted in a reduction of
vascular endothelial growth factor
secretion in
colon cancer
cells and an inhibition of tube formation by HUVECs. Thus, our results suggest that PGE(2) induces the expression of proinflammatory cytokine IL-1alpha, which may potentially enhance the proneoplastic actions of the cyclooxygenase-2/PGE(2) signaling pathway.
...
PMID:Prostaglandin E2 induces the expression of IL-1alpha in colon cancer cells. 1737 64
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