Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 expression of HLA class I antigens was studied by immunohistochemistry in various tumors in correlation with clinicopathologic characteristics. Reduced expression was observed in germ cell testicular cancer, kidney, prostate, gastric and colon cancer, and was associated with tumor aggressiveness, grade and penetration of the tumor through the organ wall. In bladder cancer reduced expression was associated with poor survival. Irradiation of brain tumors resulted in an increase in class I expression. Soluble class I levels were studied in breast and colon cancer patients and were found to be high in those with metastatic disease. The clinical relevance of reduced class I levels are discussed.
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PMID:HLA class I antigen expression in human solid tumors. 900 63

5-Fluorouracil (5-FU) and human recombinant gamma-interferon (gamma-IFN) were found to increase the expression of carcinoembryonic antigen (CEA) in human cancer cells in vitro. In the present study, the antimetabolite was associated with gamma-IFN or folinic acid (FA), a biochemical modulator of cellular metabolism of 5-FU, able to increase its antineoplastic activity. Treatment of two human colon cancer cell lines (HT-29 and WiDr) with 5-FU + gamma-IFN resulted in an increase of CEA expression higher than that obtainable with both agents alone, although no synergistic effects were obtained. This was demonstrated in terms of: (a) mRNA transcripts (HT-29); (b) cytoplasm and membrane CEA protein levels detected by Western blot analysis (HT-29); and (c) plasma membrane reactivity determined by flow cytometry analysis (HT-29 and WiDr). Moreover, 5-FU + gamma-IFN increased HLA class I molecules in the HT-29 cell membrane over that obtainable with gamma-IFN alone. In contrast, both agents did not induce the expression of the costimulatory molecule B7-1. Treatment with FA enhanced the antitumor effect of 5-FU but not its ability to augment CEA expression. This suggests that the FA-sensitive biochemical mechanism of action of 5-FU is not involved in its effect on CEA expression. In vivo studies showed, for the first time, that 5-FU, alone or combined with gamma-IFN, increases the amount of CEA protein over controls, either in cancer cells or in peripheral blood of nude mice bearing HT-29 cells. These results could be of potential diagnostic and/or therapeutic value when CEA protein is the target of humoral or cell-mediated immunity.
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PMID:Effect of the combined treatment with 5-fluorouracil, gamma-interferon or folinic acid on carcinoembryonic antigen expression in colon cancer cells. 979 80

We have previously identified mutated ras peptides reflecting the glycine to valine substitution at position 12 as HLA-A2-restricted, CD8+ CTL neo-epitopes. CTL lines produced against these peptide epitopes lysed the HLA-A2+ Ag-bearing SW480 primary colon adenocarcinoma cell line, although IFN-gamma treatment of the targets was necessary to achieve efficient cytotoxicity. Here, we compared the lytic phenotype of the SW480 cell line to its metastatic derivative, SW620, as an in vitro paradigm to further characterize the nature of a HLA class I-restricted, Ag-specific CTL response against neoplastic cell lines of primary and metastatic origin. Although both colon carcinoma cell lines were lysed by these Ag-specific CTL following IFN-gamma pretreatment, the mechanisms of lysis were distinct, which reflected differential levels of sensitivity to the Fas pathway. Whereas IFN-gamma pretreatment rendered SW480 cells sensitive to both Fas-dependent and -independent (perforin) pathways, SW620 cells displayed lytic susceptibility to Fas-independent mechanisms only. Moreover, pretreatment of SW480 cells with the anti-colon cancer agent, 5-fluorouracil (5-FU), led to enhanced Fas and ICAM-1 expression and triggered Ag-specific CTL-mediated lysis via Fas- and perforin-based pathways. In contrast, these phenotypic and functional responses were not observed with SW620 cells. Overall, these data suggested that 1) IFN-gamma and 5-FU may enhance the lytic sensitivity of responsive colon carcinoma cells to immune effector mechanisms, including Fas-induced lysis; 2) the malignant phenotype may associate with resistance to Fas-mediated lysis in response to Ag-specific T cell attack; and 3) if Ag-specific CTL possess diverse lytic capabilities, this may overcome, to some extent, the potential "escape" of Fas-resistant carcinoma cells.
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PMID:Differential role of Fas/Fas ligand interactions in cytolysis of primary and metastatic colon carcinoma cell lines by human antigen-specific CD8+ CTL. 1077 5

Preliminary studies, performed in our laboratory, showed that staurosporine (ST), a protein-kinase (PK) inhibitor, increases the expression of the carcinoembryonic antigen (CEA) in a human colon cancer cell line. The present study explores the cellular and molecular effects of ST on the CEA expression in breast cancer MCF-7 line and in a number of colon cancer cell lines characterized by the different basal levels of the antigen, including two cloned sublines (i.e. C22.20 and C6.6, expressing low and high CEA levels, respectively). In all cases, increase of the CEA expression was observed at drug concentrations devoid of marked cytostatic effects (e.g. 5 nM) and was accompanied by the enhanced CEA shedding in the supernatant. Moreover, the increase of the CEA levels both occurred in the cell membranes and in the cytosolic compartments and appeared to be the result of the enhanced CEA gene transcription. Similar results have been previously obtained with interferon-gamma. However, ST treatment, different from interferon-gamma, did not up-regulate the level of the HLA class I molecules. A preliminary investigation also showed that other PKC inhibitors did not substantially modulate the CEA expression. Therefore, the biochemical mechanism underlying the effect of ST should not be correlated with that involved in the PKC inhibition. The present study suggests that ST and, presumably, its analogs used in the cancer treatment could enhance the CEA expression on neoplastic cells in patients affected by the CEA-positive malignancies. This appears to be of potential clinical interest for the development of new immunotherapeutic or diagnostic approaches based on the pharmacological modulation of this antigenic marker.
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PMID:Pharmacological modulation of carcinoembryonic antigen in human cancer cells: studies with staurosporine. 1201 4

Mutations of p53 gene occur in approximately 50% of human cancers, and accumulated p53 protein may be an appropriate target molecule to use for cancer immunotherapy. Indeed, mutated or nonmutated p53-derived peptides can induce HLA class I-restricted and tumor cell-reactive CTLs in vitro. However, to our knowledge, evidence that p53-derived peptides are truly recognized by CTLs at tumor sites has not yet been obtained. This study revealed that a mutated p53 gene encoded a nonmutated nonapeptide recognized by a HLA-B46-restricted and tumor cell-reactive CTL line that was established from T cells infiltrating a colon cancer lesion with the p53 mutation. This p53 peptide, at amino acid positions 99-107, had the ability to induce HLA-B46-restricted and peptide-specific CTLs reactive to tumor cells with the p53 mutation from the peripheral blood mononuclear cells of cancer patients, but not from those of healthy donors. These peptide-induced CTLs did not react to either HLA-B46(+) tumor cells without the p53 mutation or to HLA-B46(+) phytohemagglutinin-blastoid cells. These results provide a scientific basis for the development of p53-directed specific immunotherapy for HLA-B46(+) cancer patients.
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PMID:Mutated p53 gene encodes a nonmutated epitope recognized by HLA-B*4601-restricted and tumor cell-reactive CTLs at tumor site. 1259 37

Dendritic cells (DC) are the most potent antigen-presenting cells known, currently tested for vaccination studies in cancer patients. The use of tumor-derived RNA to load DC overcomes the requirement of defined HLA types and the identification of tumor antigens expressed by the tumors. Here, we show that human monocyte-derived DC generated under serum-free conditions by GM-CSF, IL-4 and TNF-alpha acquire a mature phenotype and expression of the chemokine receptor CCR-7, which plays a pivotal role in DC migration to the afferent lymph nodes. We demonstrate the feasibility of total RNA transfection into such DC using the renal cell carcinoma (RCC) cell line N43-EGFP, which was stably transfected with an EGFP-encoding vector. Moreover, we show that DC transfected with RNA from colorectal cancer cells present HLA class I-restricted antigenic epitopes to induce a primary antitumor CTL response in vitro. Interestingly, the CTL induced by SW480 RNA also recognized another colon cancer line, HCT116, and the RCC line A498. Our results confirm the feasibility of total RNA transfection of serum-free generated DC for the induction of CTL against colon cancer and RCC cells, and support the relevance of shared tumor rejection epitopes between colorectal cancer and RCC.
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PMID:Dendritic cells transfected with tumor RNA for the induction of antitumor CTL in colorectal cancer. 1263 42

Inhibitory natural killer cell receptor (NKR)-expressing cells may induce a graft-versus-leukemia/tumor (GVL/T) effect against leukemic cells and tumor cells that have mismatched or decreased expression of HLA class I molecules and may not cause graft-versus-host disease (GVHD) against host cells that have normal expression of HLA class I molecules. In our study, we were able to expand inhibitory NKR (CD94/NKG2A)-expressing CD8+ T cells from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells (G-PBMCs) by more than 500-fold using stimulation by an anti-CD3 monoclonal antibody with interleukin 15 (IL-15). These expanded and purified CD94-expressing cells attacked various malignant cell lines, including solid cancer cell lines, as well as the patients' leukemic cells but not autologous and allogeneic phytohemagglutinin (PHA) blasts in vitro. Also, these CD94-expressing cells prevented the growth of K562 leukemic cells and CW2 colon cancer cells in NOD/SCID mice in vivo. On the other hand, the CD94-expressing cells have low responsiveness to alloantigen in mixed lymphocyte culture (MLC) and have high transforming growth factor (TGF)-beta1- but low IL-2- producing capacity. Therefore, CD94-expressing cells with cytolytic activity against the recipient's leukemic and tumor cells without enhancement of alloresponse might be able to be expanded from donor G-PBMCs.
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PMID:Cytolytic activity and regulatory functions of inhibitory NK cell receptor-expressing T cells expanded from granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells. 1507 36

The action of the somatostatin analog SMS-201.995 (SMS) was tested in monotherapy and in combined therapy with the cytotoxic agent 5-fluorouracil (5-FU) on cell cycle kinetics of the human colon cancer cell line WiDr, expressing a mutant p53 (mp53). The data, obtained by flow cytometric DNA analysis, showed that SMS at 0.2 microg/ml increased apoptosis, augmenting the proportion of cells with subdiploid DNA content by 65 and 48% after 3 and 6 h, respectively. In cultures lasting 24 and 36 h, it also decreased the percentages of cells in G0/G1 phase by 22.9 and 14.3%; whereas at a dose of 0.1 microg/ml, SMS decreased the percentage of cells in G2/M by 14.3%. In contrast to SMS, 5-FU (0.1 microg/ml) augmented the apoptosis at 12 h, and markedly increased the fraction of cells in S phase, increasing its value from 24 and 72 h by 108 and 234%, respectively, in comparison to the control. The most evident finding after the combination of SMS (0.2 microg/ml) and 5-FU (0.1 microg/ml) was a potentiation of 5-FU-induced S-phase block by a further 7.9, 12.9 and 42.1% at 24, 36 and 72 h, respectively. Treatment with 5-FU also upregulated HLA class I expression of the cancer cells. In this sense, SMS was less effective and when given in combination with 5-FU did not change the effects induced by 5-FU. The data emphasize that SMS exhibits pro-apoptotic and anti-proliferative effects, which in proper dose combinations might enhance the effects of 5-FU on human colorectal cancer cells expressing mp53.
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PMID:SMS 201-995 enhances S-phase block induced by 5-fluorouracil in a human colorectal cancer cell line. 1616 75

Prostate-specific antigen (PSA) is a representative of the prostate-related antigens, and has been considered to be a tumor marker of prostate cancer. However, some studies suggest that PSA could be produced by several types of tumors. In the present study, we attempted to determine whether or not PSA could be a target molecule in specific immunotherapy for patients with colon cancer. Five colon cancer cell lines were examined for their PSA expression at the mRNA and protein levels by RT-PCR and immunocytostaining, respectively. As a result, four cell lines were found to be positive for PSA at both the mRNA and protein levels. We also attempted to determine whether PSA-reactive cytotoxic T lymphocytes (CTLs) could be induced from the peripheral blood mononuclear cells (PBMCs) of HLA-A24+ colon cancer patients by in vitro stimulation with PSA-derived peptides. As a consequence, PSA peptide-specific CTLs could be generated from the PBMCs of male and female colon cancer patients. Their cytotoxicity against HLA-A24+ PSA-expressing colon cancer cells was dependent on HLA class I-restricted and CD8+ T cells. These findings indicate that PSA-reactive CTL precursors are present in the periphery of colon cancer patients, and that PSA could be a target molecule in specific immunotherapy to colon cancer.
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PMID:Prostate-specific antigen-reactive cytotoxic T lymphocyte precursors in colon cancer patients. 1639 48

Cancer stem-like cells (CSCs) and tumor-initiating cells (TICs) are a small population of cancer cells that share three properties: tumor initiating ability, self-renewal, and differentiation. These properties suggest that CSCs/TICs are essential for tumor maintenance, recurrence, and distant metastasis. Here, we show that cytotoxic T lymphocytes (CTLs) specific for the tumor-associated antigen CEP55 can efficiently recognize colon CSCs/TICs both in vitro and in vivo. Using Hoechst 33342 dye staining, we isolated CSCs/TICs as side population (SP) cells from colon cancer cell lines SW480, HT29, and HCT15. The SP cells expressed high levels of the stem cell markers SOX2, POU5F1, LGR5, and ALDH1A1 and showed resistance to chemotherapeutic agents such as irinotecan or etoposide.To evaluate the susceptibility of SP cells to CTLs, we used CTL clone 41, which is specific for the CEP55-derived antigenic peptide Cep55/c10orf3_193 (10) (VYVKGLLAKI). The SP cells expressed HLA class I and CEP55 at the same level as the main population cells. The SP cells were susceptible to CTL clone 41 at the same level as main population cells. Furthermore, adoptive transfer of CTL clone 41 inhibited tumor growth of SW480 SP cells in vivo. These observations suggest that Cep55/c10orf3_193(10) peptide-based cancer vaccine therapy or adoptive cell transfer of the CTL clone is a possible approach for targeting chemotherapy-resistant colon CSCs/TICs.
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PMID:Cytotoxic T lymphocytes efficiently recognize human colon cancer stem-like cells. 2143 60


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