Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD40 is a receptor at the surface of B lymphocytes with important functions in the immune response. CD40 has also been found on a variety of carcinoma and melanoma cell lines where it has been suggested to serve as a possible receptor for mitogenic signals. We studied the expression and distribution of CD40 in paraffin sections of 71 uniformly treated malignant melanomas (MMs) with a long clinical follow-up using well known monoclonal antibodies. For comparison, 71 benign nevi were also studied. Common acquired nevi occasionally expressed CD40 in nests or single cells at the dermo-epidermal junction; no immunoreactivity was observed in the dermal part of acquired nevi, and all Spitz' nevi were entirely negative. One-third of large congenital nevi expressed CD40 in small clusters of heavily pigmented, epithelioid cells, corresponding to so-called proliferative nodules. In 41 of 71 MMs, CD40 was expressed in single or clustered neoplastic melanocytes; 9 cases showed CD40 expression only in the radial growth phase, and in 32 cases, the vertical growth phase showed CD40 expression. The same staining pattern was obtained with other anti-CD40 monoclonal antibodies, directed to different epitopes of the CD40 molecule. In 29 of 32 MMs showing CD40 in the vertical growth phase, expression of the CD40 ligand (CD40L) was studied; in 13 of these 29, CD40L was found in the same tumor areas that expressed CD40. Analysis of 28 metastases from 24 MM patients showed in the majority of cases a similar, scattered or nodular staining pattern as observed in the primary tumor. Patients expressing CD40 in the vertical growth phase of their MM did not differ significantly from CD40-negative patients with respect to any of the known prognostic parameters but showed a significantly shorter tumor-free survival. Patients with CD40+ CD40L+ MM tended to have a shorter tumor-free survival than those lacking CD40L. We conclude that CD40 represents a novel prognostic parameter in primary cutaneous MM. The co-localization of CD40 and CD40L suggests an autocrine growth loop in the vertical growth phase of MM.
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PMID:CD40 is a prognostic marker in primary cutaneous malignant melanoma. 895 30

Here, we report the functional expression of CD40 on human malignant melanomas (MMs). Comparison of tumor specimen from MM precursor lesions, primary tumors, and metastases revealed that CD40 surface expression is down-regulated during tumor progression. CD40 expression was confirmed in 7 human MM cell lines established from immunogenic primary tumors or metastases, whereas 11 cell lines established from advanced stages were CD40 negative. CD40 expression could be enhanced in CD40-positive MM by stimulation with IFN-gamma and tumor necrosis factor-alpha but not by interleukin (IL)-1beta or CD40 triggering. CD40 ligation on MM by CD40L-transfected murine L-cells or by a soluble CD40L fusion protein up-regulated their expression of intercellular adhesion molecule-1 and MHC class I and class II molecules and their secretion of IL-6, IL-8, tumor necrosis factor-a, and granulocyte macrophage colony-stimulating factor and also induced a rapid activation of the transcription factor nuclear factor kappaB. Furthermore, CD40 ligation of a HLA-A2+, MelanA/MART1+ MM cell line enhanced its susceptibility to specific lysis by a HLA-A2-restricted, MelanA/MART-1-specific CTL clone. Finally, CD40 ligation induced growth inhibition and apoptosis in MM. These results indicate that CD40-CD40L interactions may play an important role in augmenting antitumor immunity and inducing apoptosis in some CD40-positive immunogenic human MMs.
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PMID:Stimulation of CD40 on immunogenic human malignant melanomas augments their cytotoxic T lymphocyte-mediated lysis and induces apoptosis. 1009 61

Classical and molecular immunological means of active tumor-specific immunization against human cancers yielded whole cell or tumor cell lysate vaccines of preventive value (reduced relapse rates) and dendritic cell-peptide or genetically engineered vaccines that may induce remissions even in metastatic disease. Active tumor-specific immunization was often successful in the past 50 years against experimental tumors maintained in the laboratory. During the epochs of classical and molecular immunology several vaccines were generated and used for the reduction of relapse rates of human cancer after surgical removal of the primary or metastatic tumors. Whole cell vaccines consist of X-irradiated autologous or allogeneic tumor cells coadministered with immunostimulants (BCG, Detox). Tumor cells haptenized biologically (as in viral oncolysates) or chemically were also used. Dendritic cell vaccines are prepared by transfection or transduction with tumor antigen-encoding DNA or by pulsing the cells with antigenic peptides in vitro; or collecting dendritic cells that engulfed apoptotic tumor cell DNA and/or peptide antigens in vivo for reinjection into the patient. Genetically engineered tumor cells are prepared in vitro to express MHC and peptides, costimulatory molecules (B7.1) and cyto- or lymphokines (interferons, interleukins, hematopoietic growth factors) for vaccination of patients. Antibody- and immune T cell-mediated immune reactions to autologous tumor cells are newly generated and/or quantitatively increased in immunized patients but do not always correlate with clinical response. Most vaccines are claimed to have reduced relapse rates presumably by inducing effective host immunity against micrometastases. Dendritic cell-peptide vaccines could induce partial or occasionally complete remissions in metastatic disease. The wrong antigenic presentation may result in tolerance induction toward the tumor; occasionally tumor enhancement may occur. Human tumor antigens when presented appropriately (with costimulatory molecules and with IL-2, IL-12) break the host's natural tolerance toward its tumor and induce rejection strength immune reactions even in patients with metastatic disease. Immune T cells thus generated could be collected for adoptive immunotherapy. For successful active specific immunization against human cancers the understanding of the immunoevasive maneuvers of the tumor cell (through FasL --> Fas; TRAIL; CD40L --> CD40; TGFbeta etc. systems) is essential.
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PMID:Vaccination against human cancers (review). 1060 52

This study focuses on the specific CD4+ T cell requirement for optimal induction of cytotoxicity against MHC class II negative autologous tumors (AuTu) collected from patients with various types of cancer at advanced stages. CD4+ T cells were induced in cultures of cancer patients' malignant effusion-associated mononuclear cells with irradiated AuTu (mixed lymphocyte tumor cultures (MLTC)) in the presence of recombinant IL-2 and recombinant IL-7. Tumor-specific CD4+ T cells did not directly recognize the AuTu cells, but there was an MHC class II-restricted cross-priming by autologous dendritic cells (DCs), used as APC. CD8+ CTL, also induced during the MLTC, lysed specifically AuTu cells or DCs pulsed with AuTu peptide extracts (acid wash extracts (AWE)) in an MHC class I-restricted manner. Removal of CD4+ T cells or DCs from the MLTC drastically reduced the CD8+ CTL-mediated cytotoxic response against the AuTu. AWE-pulsed DCs preincubated with autologous CD4+ T cells were able, in the absence of CD4+ T cells, to stimulate CD8+ T cells to lyse autologous tumor targets. Such activated CD8+ T cells produced IL-2, IFN-gamma, TNF-alpha, and GM-CSF. The process of the activation of AWE-pulsed DCs by CD4+ T cells could be inhibited with anti-CD40 ligand mAb. Moreover, the role of CD4+ T cells in activating AWE-pulsed DCs was undertaken by anti-CD40 mAb. Our data demonstrate for the first time in patients with metastatic cancer the essential role of CD4+ Th cell-activated DCs for optimal CD8+ T cell-mediated killing of autologous tumors and provide the basis for the design of novel protocols in cellular adoptive immunotherapy of cancer, utilizing synthetic peptides capable of inducing T cell help in vivo.
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PMID:Tumor-specific CD4+ T lymphocytes from cancer patients are required for optimal induction of cytotoxic T cells against the autologous tumor. 1072 53

The induction of tumor-protective immunity against malignancies remains a major challenge in cancer immunotherapy. A novel, humanized anti-ganglioside-GD(2)-IL-2 immunocytokine (hu14.18-IL-2) induced CD8(+) T cells to eradicate established pulmonary metastases of B78-D14 murine melanoma, in a process that required help by CD4(+) T cells and was mediated by the CD40/CD40 ligand (CD40L) interaction. The anti-tumor effect was diminished in mice deficient in CD4(+) T-cells. Three lines of evidence show that CD4(+) T-cell help was mediated by CD40/CD40L interaction but not by endogenous IL-2 production. First, the hu14.18-IL-2-induced anti-tumor response is partially abrogated in C57BL/6J CD40L knockout (KO) mice in contrast to C57BL/6J IL-2 KO animals, in which the immunocytokine was completely effective. Second, partial abrogation of the anti-tumor effect is induced with anti-CD40L antibodies to the same extent as with CD4(+) T-cell depletion. Third, a complete anti-tumor response induced by hu14.18-IL-2 can be reconstituted in C57BL/6J CD40L KO mice by simultaneous stimulation with an anti-CD40 mAb. These results suggest that help provided by CD4(+) T cells via CD40/CD40L interactions in our tumor model is crucial for effective immunotherapy with an IL-2 immunocytokine.
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PMID:Melanoma immunotherapy by targeted IL-2 depends on CD4(+) T-cell help mediated by CD40/CD40L interaction. 1084 21

Mice transgenic for the human MUC1 carcinoma-associated antigen (MUC1.Tg) are tolerant to immunization with MUC1 antigen. Recent studies, however, have demonstrated that immunization of MUC1.Tg mice with fusions of MUC1-positive tumour and dendritic cells (FC/MUC1) reverses MUC1 unresponsiveness and results in rejection of established MUC1-positive pulmonary metastases. Here we demonstrate that lymph node cells from MUC1.Tg mice immunized with the FC/MUC1 fusion cells proliferate in response to MUC1 antigen by a mechanism dependent on the function of CD4, major histocompatibility complex (MHC) class II, B7-1, B7-2, CD28, CD40 and CD40 ligand. The findings demonstrate that stimulation of lymph node cells with MUC1 results in selection of MUC1-specific CD8+ T cells. We show that the CD8+ T cells exhibit MUC1-specific cytotoxic T lymphocyte (CTL) activity by recognition of MUC1 peptides presented in the context of MHC class I molecules Kb and Db. The MUC1-specific CD8+ T cells also exhibit antitumour activity against MUC1-positive metastases, but with no apparent reactivity against normal tissues. These results indicate that immunization of MUC1.Tg mice with FC/MUC1 reverses immunological unresponsiveness to MUC1 by presentation of MUC1 peptides in the presence of costimulatory signals and generates MHC-restricted MUC1-specific CD8+ T cells.
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PMID:Selection and characterization of MUC1-specific CD8+ T cells from MUC1 transgenic mice immunized with dendritic-carcinoma fusion cells. 1110 34

We quantitatively evaluated dendritic cell (DC) infiltration in primary colorectal cancers from 44 patients and metastatic colorectal tumors from 13 patients using immunohistochemistry for the DC marker CD83, HLA-DR, and the DC activation molecules CD40 and CD86. Nearly all CD83+ cells were also HLA-DR+, CD40+, and CD86+, indicating that the DCs that infiltrate colon cancer in vivo express the activation and costimulatory molecules associated with a mature DC phenotype. The density of DCs in colorectal cancer primaries was three times lower than that seen in normal colonic mucosa (0.29 versus 0.84 CD83+ cells/ high-power field (hpf), p < 0.001). Dendritic cells were rarely observed in metastatic tumors: DC density in metastases was sixfold lower than in colorectal primary tumors (0.05 versus 0.29 CD83+ cells/hpf, p < 0.001). Because cytokines have been shown, in vitro, to exert potent effects on DCs, we also evaluated the relationship between intratumor DC density and the expression of cytokines by tumor-infiltrating lymphocytes (TILs) and tumor cells. Expression of interleukin-10 and transforming growth factor beta by either TIL or tumor cells was not associated with decreased DC density or decreased expression of CD40 or CD86 on DCs. Tumor expression of vascular endothelial growth factor was associated with a more than twofold increase in DC density (p = 0.01). Patients who had a high proportion of TILs expressing tumor necrosis factor (TNF) had a greater intratumor mature DC density than patients with a low proportion of TNF + TIL (0.54 versus 0.21 CD83+ cells/hpf, p < 0.01).
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PMID:Dendritic cell infiltration in colon cancer. 1126 70

We quantitatively evaluated dendritic cell (DC) infiltration in primary colorectal cancers from 44 patients and metastatic colorectal tumors from 13 patients using immunohistochemistry for the DC marker CD83, HLA-DR, and the DC activation molecules CD40 and CD86. Nearly all CD83+ cells were also HLA-DR+, CD40+, and CD86+, indicating that the DCs that infiltrate colon cancer in vivo express the activation and costimulatory molecules associated with a mature DC phenotype. The density of DCs in colorectal cancer primaries was three times lower than that seen in normal colonic mucosa (0.29 versus 0.84 CD83+ cells/ high-power field (hpf), p < 0.001). Dendritic cells were rarely observed in metastatic tumors: DC density in metastases was sixfold lower than in colorectal primary tumors (0.05 versus 0.29 CD83+ cells/hpf, p < 0.001). Because cytokines have been shown, in vitro, to exert potent effects on DCs, we also evaluated the relationship between intratumor DC density and the expression of cytokines by tumor-infiltrating lymphocytes (TILs) and tumor cells. Expression of interleukin-10 and transforming growth factor beta by either TIL or tumor cells was not associated with decreased DC density or decreased expression of CD40 or CD86 on DCs. Tumor expression of vascular endothelial growth factor was associated with a more than twofold increase in DC density (p = 0.01). Patients who had a high proportion of TILs expressing tumor necrosis factor (TNF) had a greater intratumor mature DC density than patients with a low proportion of TNF + TIL (0.54 versus 0.21 CD83+ cells/hpf, p < 0.01).
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PMID:Dendritic Cell Infiltration in Colon Cancer. 1144 69

The clinical behaviour of melanoma is often unpredictable using clinical and histological criteria. Tumour cell markers related to cell cycle regulation, apoptosis, cell-cell interactions and cell proliferation might improve the possibility of predicting the clinical course of melanoma. The aim of the present study was to refine prognostic criteria by an immunocytochemical investigation of CD44, CD40, bcl-2 antigens and cell proliferation in tumour cells aspirated from metastases of malignant melanoma. CD40 is a cell surface receptor shown to be expressed by lymphomas as well as carcinomas, and is thought to play a central role in the process of tumour progression. CD44 is a transmembrane glycoprotein, which is involved in growth signal transmission of importance in the binding of tumour cells to endothelium, cell migration and enhancement of cell motility, which makes it of interest to study in relation to the metastasizing capacity of tumours. The bcl-2 protein is active in the process of programmed cell death (apoptosis) as an antiapoptotic agent and its expression may reflect tumour progression. Mean/median percentages of tumour cell positivity were 8.5/3.0 for CD40, 76.1/86.3 for CD44 and 7.4/3.3 for bcl-2. A significant correlation was observed between expression of apoptosis-associated bcl-2 antigen and overall survival (r = 0.33). The CD44 positive cell fraction was higher in patients with short overall survival than those with long survival but this difference was not statistically significant. The expression of CD40 did not correlate with overall survival. The mean/median proliferation fraction assessed by MIB-1 monoclonal antibody was 25.8/23.9 and showed a significant correlation with survival after diagnosis of melanoma metastasis (r = 0.32). Lack of bcl-2 expression and a high proportion of tumour cells expressing Ki-67 antigen are predictors of poor prognosis that are independent of the traditionally accepted Breslow's thickness of the primary melanomas.
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PMID:Expression of CD40, CD44, bcl-2 antigens and rate of cell proliferation on fine needle aspirates from metastatic melanoma. 1198 64

All of these studies taken together highlight key areas that must be addressed in the future in order for the field to continue to move forward. These issues are many, including but not limited to method of delivery of dendritic cells to patients, maturation status of the dendritic cells, and methods of monitoring responses to these vaccines. Each of these requires some comment. Different strategies of immunization were used in these studies. DCs were injected at various times and in various locations, including intradermally/subcutaneously, intranodally, and intravenously. Investigation of the pattern of spread of subcutaneously injected fluorescently labeled DCs in the chimpanzee was studied at the University of Pittsburgh. Although rodent DCs had previously been shown to remain at the site of injection, these immature primate DCs migrated to draining lymph nodes and interact appropriately with T cells for as long as 5 days after administration. Data not shown in the same study reveal that intravenously administered DCs were undetectable in draining lymph nodes. Two groups have undertaken evaluation of route of administration of DCs in humans. The first of these examined migration of immature, indium-111-labeled dendritic cells after RNA-loading in metastatic cancer patients [44]. The DCs were injected either intravenously, subcutaneously, and intradermally. Only DCs injected intradermally were cleared from the injection site with migration to regional lymph nodes. The immunologic significance of these findings is unclear, however. Another study examined this issue by studying prostatic acid phosphatase (PAP) protein-loaded mature DCs injected intravenously, intradermally, and intralymphatically in prostate cancer patients [45]. Regardless of route of administration, T cell responses were induced as measured by proliferation when PBMCs in vitro were stimulated with the PAP protein. Cytokine analysis of the patients revealed that the majority of patients undergoing either intralymphatic or intradermal injection had increases in measurable interferon-gamma but that none of the intravenously-injected patients did. The intralymphatic and intradermal routes thus seem to lead to stronger Th1 responses. But no data was presented regarding the numbers of PAP precursors induced by vaccination nor their specificity/cytotoxicity. Another issue in DC administration that should also affect route of administration is maturation status of the dendritic cells. Many of the studies used immature dendritic cells to immunize patients whereas others used mature cells. A number of studies have demonstrated that maturation signals such as inflammatory cytokines and CD40 ligation lead to down-regulation of antigen processing and up-regulation of the chemokine receptor CCR7, which leads to homing to lymph nodes [46] as well as the MHC molecules, costimulatory molecules, and maturation markers [8,47,48]. In addition, different maturation agents and sequences of addition of these maturation agents may lead to differences in functions of dendritic cells [48-51]. Others have found that injection of immature DCs pulsed with influenza matrix peptide and KLH, and lead to greater numbers of influenza-specific T cells, but these cells had reduced interferon-gamma production and lacked killer activity [52]. Perhaps the most impressive results in a clinical trial, however, were gained by injecting similar cells loaded with melanoma peptides [21]. In addition, sequence of loading and maturation may be important in creating vaccines. One study using CEA peptides and CEA RNA found that optimal T cell presentation occurs when peptides are loaded after maturation with CD40 ligand and when RNA is transfected before maturation with CD40 ligand [53]. As all of these studies reveal, more investigation into the role of DC maturation as well as its timing and sequence is needed. Finally, a multitude of methods to detect response to vaccination have been attempted in all of the above studies. Many use DTH responses, but these may measure CD4 T cells instead of CD8 T cells. The availability of tetramers allows easier quantification of CTL precursors, but they provide no assessment of the function of these T cells. Enzyme-linked immunospot assays allow identification and quantification of numbers of cells producing cytokines such as interferon-gamma when encountering target antigens, but cytokine production may not correlate with tumor cell killing. Chromium release assays or flow cytometric assays for molecules such as perforin may be used to validate killing, but inability of many tumors to grow in vitro precludes direct assessment of tumor cell killing via this method. Other responses in human subjects may also be measured. Some of the cited studies yielded clinical responses that could be measured via physical examination or radiologic study. This is the exception rather than the rule, however. Others have monitored the decrease in serum tumor markers such as PSA or CEA. But these may not correlate directly with tumor burden. Indirect calculation of tumor burden by using quantitative PCR to estimate the number of circulating tumor cells in peripheral blood may be promising in this regard. Despite the lack of consensus as to what constitutes an effective response, most would agree that monitoring of these patients should include measures of both immunologic response and clinical tumor effect. All of this leads to the conclusion that DC-based cancer vaccines have progressed a great deal but that much work still needs to be done. Only rigorous bench top experimentation followed by careful patient selection and vaccine administration, and then by meticulous patient monitoring, will lead to advances in the field.
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PMID:Dendritic cell gene therapy. 1248 60


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