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

Tumor cells escape immunologic rejection through diverse mechanisms. Fas and its ligand represent one such mechanism. Recently we reported that pancreatic cancer cell lines express Fas-ligand and kill lymphoid cells by Fas-mediated apoptosis in vitro. This study was designed to determine whether human pancreatic tumors express Fas-ligand in vivo, as a potential mediator of counterattacking the host immune cells, and to determine if Fas-ligand expression correlates with clinicopathologic characteristics and patient survival. Fas-ligand expression in 45 primary pancreatic ductal cancers and two hepatic metastases was determined using immunohistochemistry. Apoptotic cells within the tumor were assessed by immunohistochemistry for the presence of single stranded DNA. Immunohistochemistry showed that 37 (82%) of the primary tumors and both of the hepatic metastases expressed Fas-ligand. Tumor infiltrating lymphoid cells were frequently apoptotic, but the cancer cells were rarely apoptotic. Patients with Fas-ligand-positive tumor had significantly shorter survival times than Fas-ligand-negative. A multivariate analysis indicated that Fas-ligand expression and the histologic margin status were significant prognostic factors. These results suggest that the expression of Fas-ligand in human pancreatic cancers and the induction of apoptosis in the infiltrating lymphoid cells may be required to counterattack the host cytotoxic T-lymphocytic and natural killer cellular responses.
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PMID:Fas ligand expression in human pancreatic cancer. 1537 95

The outcome of cancer metastasis depends on multiple interactions between the malignant cell and the host environment. Such interactions can influence primary cancer growth and metastasis by altering the balance between tumor cell proliferation and death. We have previously reported that the pro-apoptotic protein FasL could potently suppress spontaneous lung metastasis of the Fas-sensitive melanoma, K1735-P. In this report, we have constructed bone marrow chimeric mice using wt and FasL-deficient animals to delineate the source of FasL (hematopoietic or nonhematopoietic) required to control spontaneous metastatic spread from a subcutaneous tumor. Using FasL-deficient animals (gld) reconstituted with wt FasL bone marrow (wt --> gld), and wt animals reconstituted with FasL-derived bone marrow (gld --> wt), we show, for the first time, an essential role for hematopoietic-derived FasL in the suppression of K1735-P metastasis. When FasL was expressed only in the nonhematopoietic compartment (gld --> wt), K1735-P spread was ineffectively controlled with a metastatic phenotype similar to that observed in animals completely lacking FasL (gld --> gld or gld controls). These studies provide evidence for the indispensable role for FasL+ bone marrow-derived cells in the control of melanoma and offer a strategy to target FasL expression in the prevention or therapy of metastatic disease.
Clin Exp Metastasis 2004
PMID:Essential role for hematopoietic Fas ligand (FasL) in the suppression of melanoma lung metastasis revealed in bone marrow chimeric mice. 1538 75

Osteosacarcoma (OS) lung metastases are often resistant to chemotherapy. Most anticancer drugs are administered systemically. In many cases this is followed by dose-dependent toxicity, which may not allow the achievement of therapeutic levels in lungs to eradicate metastases. We determined the efficacy of gemcitabine (GCB) by administering it directly to the lungs via aerosol and studied the role of the Fas pathway in response to the therapy. We used 2 osteosarcoma lung metastases animal models: human LM7 cells that form lung metastases in mice following intravenous injection and murine LM8 cells, which grows subcutaneously in mice and spontaneously metastasize to the lung. Treatment was initiated when the presence of lung metastases had been established. Aerosol GCB inhibited the growth of lung metastases in mice. Intraperitoneal GCB administration at similar dosage had no effect on lung metastases. Besides its direct effect on lung metastases, aerosol GCB suppressed the growth of subcutaneous LM8 tumor. Histopathological examination of mice receiving aerosol GCB showed no evidence of toxicity. Lungs are distinguished from other tissues by the constitutive expression of FasL. Since exposure of tumor cells to GCB upregulated Fas expression, we hypothesized that the susceptibility of the tumor cells to ligand-induced cell death by resident lung cells may be increased. Therefore, the Fas pathway may contribute to the therapeutic effect of aerosol GCB.
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PMID:Aerosol gemcitabine inhibits the growth of primary osteosarcoma and osteosarcoma lung metastases. 1580 Sep 50

The expression of CCL20 (MIP-3alpha), which chemoattracts leukocytes to sites of inflammation, has been shown in intestinal epithelial cells (IEC). Aim of this study was to analyze the role of the CCL20 receptor CCR6 in IEC and colorectal cancer (CRC) cells. Expression of CCR6 and CCL20 was analyzed by RT-PCR and immunohistochemistry. Signaling was investigated by Western blotting, proliferation by MTS assays and chemotactic cell migration by wounding assays. The effect of CCL20 on Fas-induced apoptosis was determined by flow cytometry. CCR6 and its ligand CCL20 are expressed in IEC. Moreover, CRC and CRC metastases express CCR6, which is upregulated during IEC differentiation. Stimulation of IEC with CCL20 and proinflammatory stimuli (TNF-alpha, IL-1beta, LPS) significantly upregulates CCL20 mRNA expression. CCL20 expression was significantly increased in inflamed colonic lesions in Crohn's disease and correlated significantly with the IL-8 mRNA expression in these lesions (r = 0.71) but was downregulated in CRC metastases. CCL20 activated Akt, ERK-1/2, and SAPK/JNK MAP kinases and increased IL-8 protein expression. The CCL20 mediated activation of these pathways resulted in a 2.6-fold increase of cell migration (P = 0.001) and in a significant increase of cell proliferation (P < 0.05) but did not influence Fas-induced apoptosis. In conclusion, IEC and CRC express CCL20 and its receptor CCR6. CCL20 expression is increased in intestinal inflammation, while CCR6 is upregulated during cell differentiation. CCR6 mediated signals result in increased IEC migration and proliferation suggesting an important role in intestinal homeostasis and intestinal inflammation by mediating chemotaxis of IEC but also in mediating migration of CRC cells.
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PMID:Cell differentiation dependent expressed CCR6 mediates ERK-1/2, SAPK/JNK, and Akt signaling resulting in proliferation and migration of colorectal cancer cells. 1621 92

The authors' animal studies have shown that the metastatic potential of osteosarcoma (OS) cells correlates inversely with Fas expression-that is, Fas-negative cells metastasize but Fas-positive cells do not. One reason for this in the context of OS lung metastases may be that Fas-positive cells are eliminated by engagement with the Fas ligand (FasL) constitutively expressed on the surface of pneumocytes, whereas Fas-negative tumor cells are not. The purpose of this study was to determine the status of Fas expression in OS lung metastases from patients. Specifically, archived paraffin-embedded specimens of lung metastases from 38 patients with OS were analyzed by immunohistochemistry. Lung nodules from 23 of the 38 patients (60%) were Fas negative, those from 12 patients (32%) were weakly positive, and that from only 1 patient (3%) was strongly positive. Findings in the samples from the remaining two patients (5%) could not be interpreted because of extensive necrosis. Most patients with the weakly positive tumors and the single patient with the strongly positive tumor received chemotherapy prior to lung resection. There was a significant correlation between Fas expression and the administration of preoperative salvage chemotherapy (P = 0.0013). These data indicate that loss of Fas may be one mechanism by which OS cells evade host resistance in the lung. Chemotherapy may induce regression by upregulating Fas.
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PMID:Fas expression in lung metastasis from osteosarcoma patients. 1628 94

It is still controversial whether keratoacanthoma is to be considered as a well differentiated variant of squamous cell-carcinoma or a separate entity. As opposed to malignant potential of squamous cell-carcinoma, keratoacanthoma is characterized by a spontaneous regression. However, in some cases, otherwise typical keratoacanthoma can behave aggressively showing the signs of perineural and perivascular invasion and metastases in regional lymph nodes. The most important feature that separates these two closely related entities is a tendency of keratoacanthoma to regress. Causes and detailed mechanism of this regression are still not completely elucidated. Within the past few years, it has become evident that the molecular events regulating cell survival and apoptosis are important contributors to the overall kinetics of benign and malignant cell growth. Immunological mechanisms have been implicated in a phenomenon of spontaneous tumor regression. Recent studies suggested that the tumor regression is dependent mainly on the immune response mediated by cytotoxic T lymphocytes (CD8+), together with helper T cells (CD4+). Cytotoxic T lymphocytes can kill tumor cells and mediate tumor regression in vivo through two distinct molecular mechanisms: Fas/Fas ligand and granzyme B/perforin mediated pathways. Tumor cells are capable of developing different escape mechanisms in order to overcome their sensitivity to apoptotic signals. However, granzyme B, contained in cytolytic granules released upon target cell recognition, can also cause tumor cell death and consequently tumor regression by direct damage to non-nuclear structures through a caspase-independent pathway. Therefore, we propose a key role of plasticity in the granzyme B mediated cell death pathway in the killing of changed tumor cells, resulting in keratoacanthoma regression through apoptosis or direct damage of tumor cells. On the other hand, insufficient activation of cytotoxic T lymphocytes and decreased release or activity of granzyme B could be responsible for squamous cell-carcinoma progression and occasional aggressive behavior in keratoacanthomas. As a first step in confirming or refuting our hypothesis, we suggest a thorough immunohistochemical study of the presence of granzyme B and its activity in keratoacanthoma and squamous cell-carcinoma samples. To our knowledge, no such study has been performed so far.
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PMID:Possible key role of granzyme B in keratoacanthoma regression. 1649 44

The cytotoxic activity of T cells selects the outgrowth of tumor cells that escape from immune surveillance by different strategies. The different mechanisms that interfere with immune recognition and limit vaccination efficiency are still poorly understood. We analysed six cell lines established from different metastases of melanoma patient UKRV-Mel-20 for specific characteristics known to have an impact on the tumor-T cell interaction: (1) alterations in the HLA class I phenotype, (2) expression of Fas/CD95, and (3) expression of specific cytokines and chemokines. One of the cell lines, UKRV-Mel-20f, exhibited an HLA class I haplotype loss and just this cell line was also characterised by the expression of Fas/CD95 and of relatively high levels of proinflammatory chemokines suggesting that the cytotoxic activity of tumor-infiltrating T cells might have selected the outgrowth of this tumor cell variant. All other cell lines analysed showed no alterations in HLA class I expression, but, in contrast to UKRV-Mel-20f, expressed much lower levels of Fas/CD95 and of proinflammatory chemokines and some of them produced high levels of immunosuppressive TGF-beta1. These results suggest that in patient UKRV-Mel-20, tumor cells interfere with T cell recognition by different strategies which might partially explain why this patient did not have a clinical response to an autologous tumor cell vaccine.
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PMID:Identification of different tumor escape mechanisms in several metastases from a melanoma patient undergoing immunotherapy. 1662 80

In this study, we report the in vivo effects of a decoy oligonucleotide targeting the nuclear factor kappaB (NF-kappaB) on osteoclasts during forced orthodontic tooth movement in rats. Wistar rats were subjected to orthodontic forces, in the absence or presence of treatment with a decoy molecule mimicking a nonsymmetric NF-kappaB binding site (5'-CGC TGG GGA CTT TCC ACG G-3'). TUNEL staining of fragmented DNA revealed that treatment with NF-kappaB decoy but not with scramble double-stranded oligodeoxynucleotides (ODN) induced a high level of osteoclast apoptosis in vivo. Immunohystochemical analysis for death receptor Fas revealed strong positivity only in samples treated with NF-kappaB decoys, demonstrating that osteoclasts are sensitive to death induction via Fas signaling. Induction of apoptosis in osteoclasts could be a strategy for treatment of excessive osteoclast activity in pathologic conditions such as osteoporosis, peri-articular osteolysis, inflammatory arthritis, Paget's syndrome and tumour-associated osteolytic metastases.
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PMID:Local in vivo administration of a decoy oligonucleotide targeting NF-kappaB induces apoptosis of osteoclasts after application of orthodontic forces to rat teeth. 1701 9

Expression of the chemokine receptor CXCR4 by tumor cells promotes metastasis, possibly by activating prosurvival signals that render cancer cells resistant to immune attack. Inhibition of CXCR4 with a peptide antagonist, T22, blocks metastatic implantation of CXCR4-transduced B16 (CXCR4-luc-B16) melanoma cells in lung, but not the outgrowth of established metastases, raising the question of how T22 can best be used in a clinical setting. Herein, whereas the treatment of CXCR4-luc-B16 cells in vitro with the CXCR4 ligand CXCL12 did not reduce killing induced by cisplatin or cyclophosphamide, CXCL12 markedly reduced Fas-dependent killing by gp100-specific (pmel-1) CD8(+) T cells. T22 pretreatment restored sensitivity of CXCR4-luc-B16 cells to pmel-1 killing, even in the presence of CXCL12. Two immune-augmenting regimens were used in combination with T22 to treat experimental lung metastases. First, low-dose cyclophosphamide treatment (100 mg/kg) on day 5 in combination with T22 (days 4-7) yielded a approximately 70% reduction of B16 metastatic tumor burden in the lungs compared with cyclophosphamide treatment alone (P < 0.001). Furthermore, whereas anti-CTL antigen 4 (CTLA4) monoclonal antibody (mAb; or T22 treatment) alone had little effect on established B16 metastases, pretreatment with T22 (in combination with anti-CTLA4 mAb) resulted in a 50% reduction in lung tumor burden (P = 0.02). Thus, in vitro, CXCR4 antagonism with T22 renders B16 cells susceptible to killing by antigen-specific T cells. In vivo, T22 synergizes with cyclophosphamide or anti-CTLA4 mAb in the treatment of established lung metastases, suggesting a novel strategy for augmenting the efficacy of immunotherapy.
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PMID:Sensitization of B16 tumor cells with a CXCR4 antagonist increases the efficacy of immunotherapy for established lung metastases. 1704 Nov 4

Not all malignant cells progress to invasive cancer, some may even regress, but the early detection of abnormal cells can be crucial for patient survival. Immune surveillance mechanisms are complex and provide continuous efforts for the removal of transformed cells. Naturally occurring antibodies are frontier soldiers that act as the first line of defense in the battle against cancer. During the process of carcinogenesis naturally occurring antibody responses to tumor antigens were found to be associated with improved survival and protection against the spread of cancer. Using the human hybridoma technology, a series of tumor-binding antibodies can be isolated as they have several common features: they are germ-line coded IgM antibodies, they bind to various tumor-antigens, they induce apoptosis of malignant cells, and most importantly they detect not only malignant cells but also the precursor stages (i.e., autoantigens). Natural protective autoantibodies against tumor-antigens were isolated from patients and healthy donors reflecting the development of naturally occurring B-cell responses during the process of cancer evolvement. They fulfill the definition of autoantibodies since they are self-reactive and they also bind altered self-antigens such as tumor cells. In this regard various autoantibodies such as anti-dsDNA and anti-Fas autoantibodies were found to be significantly higher in patients with various carcinomas, thus playing a role for their improved survival. Targeting T-regulatory cells, namely the expression of CTLA-4 was also found to improve survival in cancer patients. Autoimmunity and malignancy frequently coexist and they may share etiological and pathological mechanisms. Therefore, the efficacy of intravenous immunoglobulins or CTLA-4 blockade was also employed as a treatment for prevention of malignancy and metastases spread.
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PMID:Protective autoimmunity in cancer (review). 1714 5


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