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)

Splenic tissues derived from patients with gastric cancer were implanted into mice with severe combined immunodeficiency (SCID) and then the mice were challenged with COLO-205, a human colon cancer cell line. Production of human immunoglobulin G (IgG) reactive against the COLO-205 cells was detected by enzyme-linked immunosorbent assay in sera from the reconstituted and tumor-bearing SCID mice. The titers of the reactive IgG relative to total IgG in the sera of SCID mice began to increase from one week after implantation of the tumor cells, and became 10- to 100-fold higher than that in the donor's serum by 3-4 weeks. This model using implantation of human cancer cells in SCID mice reconstituted with human splenic tissues would facilitate further studies of human cancer immunology.
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PMID:Production of human immunoglobulin G reactive against human cancer in tumor-bearing mice with severe combined immunodeficiency reconstituted with human splenic tissues. 139 26

T lymphocytes generally fail to recognize human colon carcinomas, suggesting that the tumour is beyond reach of immunotherapy. Bacterial superantigens are the most potent known activators of human T lymphocytes and induce T cell cytotoxicity and cytokine production. In order to develop a T-cell-based therapy for colon cancer, the superantigen staphylococcal enterotoxin A (SEA) was given tumour reactivity by genetic fusion with a Fab fragment of the monoclonal antibody C242 reacting with human colon carcinomas. The C242Fab-SEA fusion protein targeted SEA-reactive T cells against MHC-class-II-negative human colon carcinoma cells in vitro at nanomolar concentrations. Treatment of disseminated human colon carcinomas growing in humanized SCID mice resulted in marked inhibition of tumour growth and the apparent cure of the animals. Therapeutic efficiency was dependent on the tumour specificity of the fusion protein and human T cells. Immunohistochemistry demonstrated massive infiltration of human T cells in C242Fab-SEA-treated tumours. The results merit further evaluation of C242Fab-SEA fusion proteins as immunotherapy in patients suffering from colon carcinoma.
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PMID:Immunotherapy of human colon cancer by antibody-targeted superantigens. 755 85

Mice with severe combined immunodeficiency reconstituted with human splenic tissue (SCID-sp) taken from 22 patients with advanced gastric cancer and 8 with idiopathic thrombocytopenic purpura (ITP) received subsequent implants of COLO 205 human colon cancer cells. A human immunoglobulin G (IgG) reactive against COLO 205 cells (COLO 205-reactive human IgG) was produced by SCID-sp mice reconstituted with splenic tissue from 8 of the 22 gastric cancer patients, but from none of the ITP patients. Tumor growth in SCID-sp mice which produced the COLO 205-reactive human IgG was greater (tumor weight range, 106-143%) than that in the control SCID mice, while that in SCID-sp mice reconstituted with splenic tissue from 8 ITP patients and that in SCID-sp mice reconstituted with splenic tissue from the other 14 gastric cancer patients which did not produce the COLO 205-reactive IgG were considerably lower and slightly lower, respectively, than those in the control SCID mice (tumor weight range, 56.7-108% and 79.4-119%, respectively). When the COLO 205-reactive human IgG titers in the sera of the SCID-sp mice, expressed as a ratio of the titers in the corresponding patient's serum, were plotted against the tumor weight in each SCID-sp mouse, significant correlations were observed in those that received splenic tissues from 6 of the 8 patients in which the COLO 205-reactive human IgG was produced. Furthermore, the tumor growth rates increased in proportion to the increased COLO 205-reactive human IgG titers in SCID-sp mice. Therefore, the SCID-sp model should be useful to study the paradoxical tumor growth possibly due to impaired immune reaction in patients with advanced gastric cancer.
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PMID:Paradoxical enhancement of tumor growth in mice with severe combined immunodeficiency which produce a human immunoglobulin G reactive against tumor cells. 810 91

The murine IgG3 monoclonal antibody NCC-ST-421, raised against a human gastric cancer, shows strong reactivity with dimeric Le(a) (Le(a)/Le(a); V4FucIII4FucLc6Cer) expressed on gastrointestinal cancer cells. ST-421 reacted minimally with non-dimeric or simple Le(a) expressed on normal tissues. ST-421 is capable of mediating both antibody-dependent cellular cytotoxicity (ADCC) with human peripheral blood lymphocytes, and complement-dependent cytotoxicity with human complement. Interleukin-2 (IL-2) modulates the function of immunocytes, in particular inducing lymphokine-activated killer (LAK) cell activity and enhancing ADCC. We therefore employed combination immunotherapy with IL-2, LAK, and ST-421-induced ADCC in vitro and in mice with severe combined immunodeficiency (SCID), using target tumor cells expressing Le(a)/Le(a) antigen. ADCC against human colon cancer cell lines in vitro was enhanced three to four times after preincubation with IL-2. Addition of IL-2 reduced the amount of ST-421 required for efficient ADCC 10- to 100-fold. ADCC was activated by IL-2 earlier (1 day) than the generation of LAK cells (3-4 days), and at lower concentration of IL-2. These effects were specific for ST-421, as demonstrated by experiments with irrelevant antibody or irrelevant target cells. An anti-(Fc receptor) antibody blocked the ADCC but not the LAK activity in vitro. The enhancement of ADCC by IL-2 may be caused by activation of effector cells expressing Fc receptors. In vivo experiments using SCID mice inoculated with human colon cancer showed a significant tumor-growth-suppressive effect after combined therapy using human peripheral blood lymphocytes, LAK, IL-2, and ST-421. In summary, adoptive immunization with human lymphocytes activated by IL-2 and ST-421 effectively suppressed growth of gastrointestinal cancer cells expressing Le(a)/Le(a).
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PMID:Synergetic effect of interleukin-2 and cellular cytotoxicity against a novel tumor-associated carbohydrate antigen Le(a)/Le(a) (dimeric Le(a)) mediated by monoclonal antibody NCC-ST-421 in adoptive immunization using SCID mice. 834 64

Studies on liver metastasis of human colon cancer are limited because of a lack of suitable animal models. In this study, the usefulness of mice with severe combined immunodeficiency (SCID), which congenitally lack functional T and B lymphocytes, was evaluated in comparison with currently available nude mice. Three human colon cancer xenografts transplantable into nude mice were disaggregated enzymatically to obtain tumor cell suspensions, and implanted intrasplenically into SCID and nude mice. The incidence of splenic tumorigenesis and of liver metastases were significantly greater in SCID mice for all xenografts, in comparison with nude mice. In total, 33 of 36 SCID mice and 17 of 43 nude mice developed liver metastases. On the basis of this result, we conclude that SCID mice would be a more suitable model than nude mice for studying liver metastasis of human colon cancer.
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PMID:A suitable model for experimental liver metastasis of human colon cancer xenografts using mice with severe combined immunodeficiency. 844 Dec 64

MUC1 mucin is expressed in a wide variety of tumors and is considered to function as an anti-adhesion molecule which inhibits cell-to-cell interactions. To reveal the biological significance of this activity in tumor cells, MUC1 cDNA was transfected into EJNIH3T3 cells and human colon cancer cell lines, CHCY1 and DLD1. The in vivo growth rate of MUC1+ (MUC1-transfected) EJNIH3T3, CHCY1 and DLD1 cells in SCID mice was clearly lower than that of MUC1- (mock transfectant) cells. Several in vitro experiments using MUC1+ EJNIH3T3 cells were performed to analyze the mechanisms for the decreased in vivo tumor growth. It was found that (i) the in vitro growth rate of MUC1+ EJNIH3T3 cells was also decreased compared to that of MUC1- cells, (ii)the DNA synthesis of MUC1+ EJNIH3T3 cells after stimulation with either growth factor (fetal calf serum or bombesin) or extracellular matrix (collagen or fibronectin) was lower than that of MUC1- cells, and (iii) MUC1+ EJNIH3T3 cells grew more slowly than MUC1- cells on both collagen- and fibronectin-coated dishes. These data suggest that MUC1 mucin may regulate tumor cell growth through inhibition of cell-to-cell, growth factor-to-receptor and cell-to-matrix interactions.
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PMID:Effect of MUC1 mucin, an anti-adhesion molecule, on tumor cell growth. 864 88

Low tumor uptake and normal tissue toxicity limit the efficacy of RIT for the treatment of solid tumors. In this study, an intratumoral injectable gel drug delivery system for local administration of RIT was evaluated using the LS174T human colon cancer xenograft model in SCID mice. The injectable gel is a collagen-based drug delivery system designed for intratumoral (i.t.) administration, which has previously been shown to enhance drug retention at the injection site and reduce systemic drug exposure. We compared the local (tumor) retention and biodistribution of 111In-labeled NR-LU-10 monoclonal antibody given i.t. in the injectable gel versus simple aqueous solution. 111In gel given i.t. and 111In-NR-LU-10 given intraperitoneally (i.p.) were used as controls. The results showed that tumors treated with 111In-NR-LU-10 gel maintained the highest levels of radioactivity for up to 96 h. At 48 h after the administration of 111In-NR-LU-10 gel i.t., 111In-NR-LU-10 solution i.t., 111In gel i.t., or 111In-NR-LU-10 i.p., the level of radioactivity remaining in each gram of tumor was 98, 49, 45, and 16% of the injected dose, respectively. It was estimated that if 100 microCi of 90Y-NR-LU-10 were administered similarly, tumor treated with 90Y-NR-LU-10 gel i.t. would receive a dose of 90.0 Gy, whereas normal tissues in the same animal would receive a dose of approximately 2.43 Gy. In contrast, if 90Y-NR-LU-10 were delivered i.p., a comparable tumor would receive a dose of 16.8 Gy and corresponding normal tissues would receive 3.36 Gy. Consistent with these estimates, enhanced antitumor efficacy was observed when 90Y-NR-LU-10 gel was administered i.t. Tumor growth delay time was 6.9-fold (P < 0.01) longer in these animals (14.4 days) than in animals treated with 90Y-NR-LU-10 i.p. (2.1 days). Systemic toxicity was also significantly reduced in gel-treated animals as monitored by loss of body weight. This study demonstrated that intratumoral delivery of 90Y-NR-LU-10 gel markedly increased the retention of the radioisotope in tumors, enhanced the antitumor efficacy, and reduced systemic toxicity compared to systemic administration of the radiolabeled antibody. This injectable gel drug delivery system may allow for improvement in the therapeutic index for RIT.
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PMID:Intratumoral radioimmunotherapy of a human colon cancer xenograft using a sustained-release gel. 873 85

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 number of spontaneous lung metastases of the human colon cancer cell line HT29 transplanted into SCID mice was quantified. The lungs were sliced, randomly distributed in agar blocks and the number of lung metastases was counted for each of 39 animals. A nearly exponential increase of metastases with weight of the tumor at the implantation site was observed. This suggests that a critical tumor weight for the initiation of metastatic spread exists. Calculating the data, a simplified quantitative assessment of the metastatic load by counting ten histological sections only for the estimation of the total number of lung metastases is proposed.
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PMID:Quantitative assessment of spontaneous lung metastases of human HT29 colon cancer cells transplanted into SCID mice. 1077 6

Both the sulfide and sulfone metabolites of sulindac, a nonsteroidal anti-inflammatory drug, display anticarcinogenic effects in experimental models. Sulindac sulfide inhibits cyclooxygenase (COX) enzyme activities and has been reported to suppress ras-dependent signaling. However, the mechanisms by which sulindac sulfone suppresses cancer growth are not as defined. We studied the effects of these sulindac metabolites in human colon cancer-derived Caco-2 cells that have been transfected with an activated K-ras oncogene. Stable transfected clones expressed high levels of COX-2 mRNA and protein, compared with parental cells. K-ras-transfected cells formed tumors more quickly when injected into severe combined immunodeficiency disease mice than parental cells, and this tumorigenesis was suppressed by treatment with sulindac. Sulindac sulfone inhibited COX-2 protein expression, which resulted in a decrease in prostaglandin synthase E2 production. Sulindac sulfide had little effect on COX-2 in this model, but did suppress prostaglandin synthase E2 production, presumably by inhibiting COX enzyme activity. These data indicate that the sulfide and sulfone derivatives of sulindac exert COX-dependent effects by distinct mechanisms.
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PMID:Sulindac sulfone inhibits K-ras-dependent cyclooxygenase-2 expression in human colon cancer cells. 1111 42


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