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)

With the use of whole tumor cell vaccines in a rat colon cancer minimal residual disease model, we have recently demonstrated that although tissue type-specific tumor immunogens protect against recurrence in the absence of histocompatibility differences, these immunogens offer no predictable tumor-specific protection in the presence of such differences. We have therefore begun to test whether syngeneic and allogeneic rat colon cancer tumor-associated antigens (TAAs), when incorporated into the bilayers of liposomes, could function as effective immunogens in immunotherapy and immunoprotection models. Male Wistar/Furth (W/Fu) rats were inoculated with 5 X 10(6) DMH-W163 colon cancer cells. All nonimmunized animals died of widespread metastases within 2 weeks of complete local tumor resection. In experimental groups, four methods of immunotherapy were used after resection: (1) irradiated whole tumor cells, (2) butanol-solubilized membrane extracts containing TAA only, (3) liposomes only, and (4) liposomes containing TAA. Only animals receiving TAA incorporated into liposomes had a significant increase in survival (p = 0.026). Thirty percent remain disease-free 6 months later. In additional experiments, Buffalo rats were challenged with 1 X 10(6) Buffalo rat colon adenocarcinoma cells after immunization by irradiated whole tumor cells or liposomes and butanol-extracted colon cancer TAAs. Only animals in the group immunized with TAA incorporated into liposomes were significantly protected from subsequent tumor isograft challenge. These data provide evidence of a way to present solubilized colon cancer-associated immunogens that may be applicable in a more clinically relevant, allogeneic setting.
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PMID:Specific active immunotherapy with butanol-extracted, tumor-associated antigens incorporated into liposomes. 646 64

We investigated the pharmacokinetics of tetrahydrofolates following the administration of [6S,R]-folinic acid and 5-flurouracil delivered i.v., i.p., and by a combination of both routes in patients with colon cancer. The concentrations of the biologically active tetrahydrofolates ([6S]-folinic acid and 5-methyltetrahydrofolate) and the relatively inert diastereomer [6R]-folinic acid were monitored using a selective on-line coupled achiral-chiral high-performance liquid chromatographic method. In plasma, a target concentration of 5 microM active tetrahydrofolates, which is considered necessary for an optimal synergistic effect, could be achieved after i.v. or combined i.v. and i.p. administration but was not reached in a patient receiving i.p. [6S,R]-folinic acid alone. In three patients receiving i.p. [6S,R]-folinic acid a high level of [6S]-folinic acid was observed in ascites, suggesting that the peritoneal cavity may act as a storage site for tetrahydrofolates after i.p. administration. In these patients, only a trace level of the active metabolite 5-methyltetrahydrofolate was detected in ascites, which may indicate that tetrahydrofolate derivatives penetrate only minimally, if at all, into the peritoneal cavity from the central compartment. These data would indicate that a combination of i.p. and i.v. administration may, from the pharmacological point of view, indeed contribute to an improved treatment of minimal residual disease persisting in the peritoneal cavity.
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PMID:The pharmacokinetics of reduced folates after intraperitoneal and intravenous administration of racemic [6S,R]-folinic acid. 798 91

A recombinant humanized antibody-interleukin 2 fusion protein (huKS1/4-IL-2) was used to direct IL-2 to the tumor microenvironment and elicit a T cell-mediated eradication of established pulmonary and hepatic CT26-KSA colon carcinoma metastases in syngeneic BALB/c mice. This antitumor effect was specific because a fusion protein, which was nonreactive with these tumor cells, failed to exert any such effect. The efficacy of the huKS1/4-IL-2 fusion protein in eliminating metastases was documented because mixtures of monoclonal antibody huKS1/4 with recombinant human IL-2 were ineffective and, at best, only partially reduced tumor load. Two lines of evidence indicated the eradication of metastases and the absence of minimal residual disease in animals treated with the fusion protein: first, the lack of detection of CT26-KSA cells by reverse transcription-PCR, which can detect one tumor cell in 10(6) liver cells; and second, the tripling of life span. The effector mechanism involved in this tumor eradication is dependent on T cells because the IL-2-directed therapy is ineffective in T cell-deficient SCID mice. The essential effector cells were further characterized as CD8+ T cells by in vivo depletion studies. Such T cells, isolated from tumor-bearing mice after fusion protein therapy, elicited MHC class I-restricted cytotoxicity in vitro against colon carcinoma target cells. Taken together, these data indicate that fusion protein-directed IL-2 therapy induces a T cell-dependent host immune response capable of eradicating established colon cancer metastases in an animal tumor model.
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PMID:Elimination of established murine colon carcinoma metastases by antibody-interleukin 2 fusion protein therapy. 935 62

The tumour-associated antigen epithelial glycoprotein-2 (EGP-2) is a promising target for detection and treatment of a variety of human carcinomas. Antibodies to this antigen have been successfully used in patients for imaging of small-cell lung cancer and for adjuvant treatment of minimal residual disease of colon cancer. We describe here the isolation and complete characterization of high-affinity single-chain variable fragments (scFv) to the EGP-2 antigen. First, the binding kinetics of four murine whole antibodies directed to EGP-2 (17-1A, 323/A3, MOC-31 and MOC-161) were determined using surface plasmon resonance (SPR). The MOC-31 antibody has the lowest apparent off-rate, followed by MOC-161 and 323/A3. The V-genes of the two MOC hybridomas were cloned as scFv in a phage display vector and antigen-binding phage were selected by panning on recombinant antigen. The scFvs compete with the original hybridoma antibodies for binding to antigen and specifically bind to human carcinomas in immunohistochemistry. MOC-31 scFv has an off-rate which is better than those of the bivalent 17-1A and 323/A3 whole antibodies, providing it with an essential characteristic for tumour retention in vivo. The availability of these high-affinity anti-EGP-2 antibody fragments and of their encoding V-genes creates a variety of possibilities for their future use as tumour-targeting vehicles.
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PMID:High-affinity recombinant phage antibodies to the pan-carcinoma marker epithelial glycoprotein-2 for tumour targeting. 983 71

The human cell-surface antigen epithelial glycoprotein-2 recognized by the monoclonal antibody MOC-31 is an epithelial tumour-associated glycoprotein expressed in non-squamous carcinomas. MOC-31 immunoreactivity was investigated in human breast, colon, ovarian and lung cancer cell lines, grown either in vitro or in severe combined immunodeficient (SCID) mice as solid tumours and/or metastases. Three of four small-cell lung cancer cell lines (NCI-H69, OH3 and SW2) and three of four ovarian cancer cell lines (SoTu 1, 3 and 4) expressed epithelial glycoprotein-2. In contrast, all three breast (MCF-7, BT20, T47D) and all three colon (HT29, CACO2, SW480) cancer cell lines strongly reacted with monoclonal antibody MOC-31. A notable difference in MOC-31 immunoreactivity was observed in spontaneously formed lung metastases of HT29 colon cancer cells. Whereas larger metastases (> 30 cells) reacted with a similar staining pattern to the primary tumour, smaller metastases did not. These findings indicate that differentiation processes during the epithelial-mesenchymal transition occur in metastases, which lead to a transient loss of epithelial glycoprotein-2 expression during the migratory and early post-migratory period. This loss of antigen expression indicates that the process of metastases formation is a regulatory event, and this transient loss of antigen expression might represent a potential obstacle to antibody-based therapy in the setting of minimal residual disease.
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PMID:Epithelial glycoprotein-2 expression is subject to regulatory processes in epithelial-mesenchymal transitions during metastases: an investigation of human cancers transplanted into severe combined immunodeficient mice. 987 99

The positive impact on survival of traditional chemotherapeutic agents has renewed interest in developing newer cytotoxic agents and orally active compounds with improved therapeutic indices. In addition, new insights into the pathways of human tumorigenesis have led to novel approaches aimed at specific mechanism-based targets. The taxane class, of which paclitaxel was the first member, has the unique ability to promote and stabilize microtubule function directly, thereby inhibiting mitotic progression and inducing apoptotic cell death. Paclitaxel provides treatment benefit in a broad range of solid tumors including breast, ovarian, and lung cancer. The success with paclitaxel stimulated interest in the microtubule as a new therapeutic target. Taxane analogues with improved preclinical efficacy have been identified and are entering clinical trials. The enthusiasm for oral anticancer agents and the therapeutic importance of platinum compounds has led to the development of JM216 (satraplatin), a novel platinum IV coordination complex with oral activity in cisplatin-resistant cell lines, which is now in phase III trials in prostate cancer. Another compound in late development is DPPE, a chemopotentiator that enhances the in vivo antitumor effects of cytotoxic agents such as doxorubicin, cyclophosphamide, and cisplatin. Agents that inhibit topoisomerase I and II have also been of interest. TAS-103 is a dual topoisomerase I and II inhibitor with preclinical efficacy in a broad spectrum of tumors and in multidrug-resistant tumor cell lines. Vaccination strategies represent a rational therapeutic approach in the minimal residual disease or high-risk adjuvant therapy setting. The GMK and MGV vaccines utilizing ganglioside antigens overexpressed on human tumors such as melanoma and small cell lung cancer appear to induce antibody production reliably at tolerable doses and are under further clinical investigation. Inhibition of matrix metalloproteinases (MMPs) is another attractive target for intervention in several aspects of tumor progression. Local production of MMPs with subsequent degradation of the extracellular matrix is implicated in supporting tumor growth, invasion, and angiogenesis. The development of orally active, nontoxic MMP inhibitors is critical since these compounds will likely require chronic administration in conjunction with other therapies. Oncogenes and tumor suppressor genes are appealing targets for therapy since they are thought to be responsible for a significant number of cancers. Mutations in the Ras oncogene occur with great frequency in a number of human cancers including lung, pancreas, and colon cancer. Clinical development of potent and selective inhibitors of farnesyltransferase, the Ras-processing enzyme, is ongoing. These compounds uncouple Ras activity, affect tumor growth, and have demonstrated significant antitumor activity against experimental models of human cancer. The exciting compounds and novel therapeutic approaches currently under investigation by Bristol-Myers Squibb Pharmaceutical Research Institute offer great potential as effective cancer chemotherapy agents for the near future.
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PMID:Promising new developments in cancer chemotherapy. 1035 61

The main progress in surgical oncology regarding colonic cancer has been made by standardizing the mode of resection: En block resection of the tumor-bearing colon segment together with the draining lymph nodes, including the lymph nodes at the origin of the respective main vessel, is mandatory. Minimal invasive surgery is an option for resection, however, results of ongoing multicenter trials have to clarify the situation. Adjuvant therapy is used for patients in stage III, who are not included in studies. Since quality of surgery has a major influence on prognosis, this factor also needs to be taken into account when judging the impact of adjuvant therapy. New chemotherapeutic agents have been proven to be valid for palliative and probably also for adjuvant treatment. Prophylactic surgery is routine for patients with ulcerative colitis and FAP, the benefit for patients with HNPCC has to be further evaluated. New knowledge on the individual prognosis might optimize treatment; most probably this will be accomplished by detection of minimal residual disease. The impact of the sentinel node concept in colon cancer is unclear. New progress will be possible by an approach adapted to the individual problem together with accumulating and linking experience and knowledge.
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PMID:[Progress in oncological visceral surgery: colon carcinoma]. 1182 72

The use of monoclonal antibodies as adjuvants to cancer chemotherapy has drawn considerable interest in recent years, due to the success of several novel agents against a broad range of targets. One such target is EpCAM (aka GA733-2, KSA, 17-1A antigen), a human cell surface glycoprotein expressed on some normal and most neoplastic epithelial cells. It is now widely recognized as having an important role in tumor biology, especially in colorectal cancer, and since its original discovery in the early 1980s, the known mechanism by which it functions has steadily evolved. Initial studies of monoclonal antibodies directed against EpCAM demonstrated the presence of anti-idiotype networks involving both B and T cells, antibody-dependent cell cytotoxicity, and complement mediated cell death as mechanisms of tumor growth inhibition. Recently, a novel receptor for EpCAM has been described that is a member of the inhibitory group of immunoglobulin-like receptors and is present on lymphocytes, monocytes, dendritic cells, and NK cells. Neoplastic cells that interact with this receptor, named LAIR-1, may enact an immunologic escape, and thus confer a selective advantage for their growth and spread. This novel mechanism of action may add to our current understanding of how monoclonal antibodies targeted against EpCAM inhibit tumor growth. Passive vaccination with this antibody may induce a tertiary anti-idiotypic network which correlates with clinical outcome, but the mechanism behind this outcome in select patients with minimal residual disease may additionally involve a novel blockade of tumor specific immunosuppression. This review will focus on the initial discoveries of EpCAM's cellular adhesion properties, its role in normal and neoplastic cell function, its distribution and presumed mechanism of action, and clinical studies of EpCAM as a therapeutic target. Clinical trials of edrecolomab, one such monoclonal antibody, in patients with colon cancer will be reviewed and updated. While phase III trials of edrecolomab have not demonstrated improved efficacy as adjuvant therapy for stage III colon cancer, newer agents with improved affinity, less chimerism, and improved delivery may still demonstrate benefit.
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PMID:EpCAM: A new therapeutic target for an old cancer antigen. 1590 97

The interaction between the urokinase receptor (uPAR) and its ligand urokinase (uPA) mediates phenomena such as tissue remodelling, chemotaxis, tumour invasion, dissemination, proliferation, and angiogenesis. The broad-spectrum of biological processes that the uPA/uPAR interaction plays a role in has led researchers to speculate that this interaction may be a useful molecular target for therapeutic intervention in several pathological conditions, particularly in the prevention and inhibition of the dissemination of cancer cells. In syngeneic and xenograft murine tumour models, in which metastasis is driven by the uPA/uPAR interaction, inhibition of primary tumour growth, metastasis and angiogenesis has been shown with several proteins acting as uPAR antagonists. Immunohistochemistry, in conjunction with prognostic studies, has implicated the uPA/uPAR interaction in the dissemination of tumours, such as malignant melanoma, colon cancer, non-small cell lung cancer (NSCLC) and stomach cancer, as well as breast and ovarian carcinomas. A potential inhibitor of the uPA/uPAR interaction should result in a significant increase in the disease-free interval and survival time following resection of the primary tumour in a clinical Minimal Residual Disease (MRD) setting. Low molecular weight uPAR antagonists should be orally active, and have few side-effects, excellent bioavailability, favourable pharmacokinetic properties and a long half-life. Furthermore, these compounds should be able to inhibit the dissemination of cancer cells without the need for targeted drug and vector delivery.
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PMID:Urokinase receptor antagonists: novel agents for the treatment of cancer. 1599 80

Colorectal carcinoma is a leading cause of cancer-related mortality. Despite the introduction of new cytotoxic drugs, improved surgical and radiotherapeutic techniques, a large proportion of colorectal carcinomas remain incurable. New targeted therapeutic strategies, including immunotherapy, are being explored as complementary treatments. Recent advances in immunology and molecular biology have opened new avenues for the clinical testing of rationally designed vaccination strategies against cancer. The present report reviews the results of therapeutic vaccine trials in colorectal carcinoma, published mainly in the past 6 years. Tumor-associated antigens (self-antigens) have been targeted by therapeutic vaccination in more than 2000 colorectal carcinoma patients. The results demonstrate that tumor antigen-specific immune responses are reproducibly induced; that is, tolerance can be reversed, without the induction of serious adverse events or autoimmune disorders. No long-term autoimmune side effects have been observed after a minimum follow-up of 4 years in over 700 patients. Over 1300 colorectal carcinoma patients with minimal residual disease have been enrolled in randomized controlled Phase II/III trials using autologous tumor cell vaccines. A significantly improved overall survival was noted for Stages I-IV colorectal carcinoma patients utilizing Newcastle-disease virus as an adjuvant. Autologous tumor cells mixed with bacillus Calmette-Guerin (BCG) were of significant clinical benefit for patients with Stage II colon cancer. Results of randomized controlled trials targeting Ep-CAM have shown clinical benefit in subgroups of patients. Several new generation vaccines have demonstrated excellent safety profile and immunogenicity. Some studies have also demonstrated a statistically significant correlation between the induced immune response and prolonged overall survival, which should be confirmed in enlarged trials. Although it is unlikely that active specific immunotherapy will provide a standard complementary therapeutic approach for colorectal carcinoma in the near future, the results so far are encouraging. Randomized controlled vaccine trials targeting molecularly defined tumor antigens are warranted, particularly in colon carcinoma with minimal residual disease.
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PMID:Towards therapeutic vaccines for colorectal carcinoma: a review of clinical trials. 1602 48


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