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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemokines are a family of proteins associated with the trafficking of leukocytes in physiological immune surveillance and inflammatory cell recruitment in host defence. They are classified into four classes based on the positions of key cystiene residues: C, CC, CXC, and CX3C. Chemokines act through both specific and shared receptors that all belong to the superfamily of G-protein-coupled receptors. Besides their well-established role in the immune system, several recent reports have demonstrated that these proteins also play a role in the central nervous system (CNS). In the CNS, chemokines are constitutively expressed by microglial cells, astrocytes, and neurons, and their expression can be increased after induction with inflammatory mediators. Constitutive expression of chemokines and chemokine receptors has been observed in both developing and adult brains, and the role played by these proteins in the normal brain is the object of intense study by many research groups. Chemokines are involved in brain development and in the maintenance of normal brain homeostasis; these proteins play a role in the migration, differentiation, and proliferation of glial and neuronal cells. The chemokine stromal cell-derived factor 1 and its receptor, CXCR4, are essential for life during development, and this ligand-receptor pair has been shown to have a fundamental role in neuron migration during cerebellar formation. Chemokine and chemokine receptor expression can be increased by inflammatory mediators, and this has in turn been associated with several acute and chronic inflammatory conditions. In the CNS, chemokines play an essential role in neuroinflammation as mediators of leukocyte infiltration. Their overexpression has been implicated in different neurological disorders, such as multiple sclerosis, trauma, stroke, Alzheimer's disease, tumor progression, and acquired immunodeficiency syndrome-associated dementia. An emerging area of interest for chemokine action is represented by the communication between the neuroendocrine and the immune system. Chemokines have hormone-like actions, specifically regulating the key host physiopathological responses of fever and appetite. It is now evident that chemokines and their receptors represent a plurifunctional family of proteins whose actions on the CNS are not restricted to neuroinflammation. These molecules constitute crucial regulators of cellular communication in physiological and developmental processes.
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PMID:Chemokines and their receptors in the central nervous system. 1145 67

Chemokines are cytokines which induce chemotaxis on many cell types, thus regulating cell migration within inflammatory and allergic sites, and leucocyte homing. Also, they play a crucial role in inflammatory and tumor-associated angiogenesis, as well as in tumor progression. Chemokines are grouped into: 1) alpha or CXC; 2) beta or CC; 3) gamma or C; 4) delta or CX3C molecules. Each of them recognizes one or more cell surface receptors, named CXCR, CCR, XCR, CX3CR respectively, according to the corresponding subfamily. Many chemokines have been identified within tumor tissues, as a secretory product of tumor cells and/or inflammatory cells. The CXC chemokines (such as IL-8, IP10, Mig, SDF-1 alpha) or CC chemokines (such as MCP-1, MIP-1 alpha, eotaxin, RANTES) have been frequently harvested from tumor tissues or the biological fluids of patients. Some chemokines inhibit tumor growth and progression by activating immunocompetent cytolytic cells or inhibiting tumor-associated angiogenesis. In contrast, other chemokines induce tumor progression by interacting with the specific receptor expressed on the tumor cells and hence by activating chemotaxis and secretion of proteolytic enzymes, or by inducing angiogenesis and metastatic spreading. Sometimes neoplastic cells express chemokine receptors which are not expressed on their normal counterpart. Data from this lab show the CXCR3 expression by cells from lymphoproliferative diseases, such as multiple myeloma and lymphoma, and the stimulation of an invasive phenotype following interaction with specific chemokines.
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PMID:[Chemokines and tumors]. 1248 85

Recent evidence attributed important influence of chemokines and their receptors on motility, homing, and proliferation of cancer cells at specific metastatic sites. Here we report that the CXCL12 (SDF-1alpha) chemokine receptor CXCR4 is expressed in human ductal carcinoma in situ (DCIS) as well as in atypical ductal hyperplasia. CXCR4 was expressed in pure DCIS and DCIS with concurrent invasive disease. In 66% of the samples, atypical ductal hyperplasia was present, and > 92% exhibited positive CXCR4-staining. Expression of CXCR4 at this very early step of tumor development indicates a role of this receptor in providing a selective advantage to such cells on their way to metastasizing carcinomas. These results strengthen the ideas to target chemokine networks involved in tumor progression and metastatis as a therapeutic approach in malignant disease or as a chemoprevention strategy, blocking the transition from premalignancy to malignancy.
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PMID:CXCR4 is expressed in ductal carcinoma in situ of the breast and in atypical ductal hyperplasia. 1502 22

Chemokines and their receptors have emerged as attractive targets regulating the migration of tumor cells in vivo, a process known as cancer metastasis. The control of metastasis is critical to the control of cancer progression. Two chemokine receptors and their ligands stand out as likely targets for therapeutics: CCR7/CCL21 for lymph node metastases, and CXCR4/CXCL12 for lung, liver, bone marrow, and brain metastases. The most widely expressed chemokine receptor among cancers is likely to be CXCR4.
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PMID:Chemokines in neoplastic progression. 1524 53

Here we describe the comprehensive gene expression profiles of each cell type composing normal breast tissue and in situ and invasive breast carcinomas using serial analysis of gene expression. Based on these data, we determined that extensive gene expression changes occur in all cell types during cancer progression and that a significant fraction of altered genes encode secreted proteins and receptors. Despite the dramatic gene expression changes in all cell types, genetic alterations were detected only in cancer epithelial cells. The CXCL14 and CXCL12 chemokines overexpressed in tumor myoepithelial cells and myofibroblasts, respectively, bind to receptors on epithelial cells and enhance their proliferation, migration, and invasion. Thus, chemokines may play a role in breast tumorigenesis by acting as paracrine factors.
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PMID:Molecular characterization of the tumor microenvironment in breast cancer. 1526 Nov 34

Despite the biological and clinical importance of the interaction between the chemokine receptor CXCR4 and its ligand CXCL12 (SDF-1alpha) in human cancers, little is known about transcriptional regulation of the CXCR4 gene. Although aberrant hypermethylation in cancer has been described typically in genes with tumor-suppressor properties, this epigenetic alteration has also been observed to affect potential cancer-promoting genes. We now demonstrate that DNA methylation influences CXCR4 expression in human pancreatic cancer. Gene expression profiling and reverse transcription-PCR identified a significant proportion of pancreatic cancer cell lines that displayed little or no CXCR4 mRNA expression. Using methylation-specific PCR, combined bisulfite restriction analysis, and bisulfite sequencing, we found the 5' CpG islands of the CXCR4 gene to be unmethylated in normal pancreas, whereas promoter hypermethylation was detected in 45% (9 of 20) of pancreatic cancer cell lines and in 46% (46 of 100) of primary pancreatic adenocarcinomas. There was a significant inverse correlation between methylation and mRNA expression level of CXCR4 (P=0.008) in a large panel of pancreatic cancer cell lines. Constitutive as well as inducible expression of CXCR4 could be restored in methylated cell lines pharmacologically using epigenetic modifying drugs. These findings demonstrate the first evidence for epigenetic regulation of CXCR4 in human cancers, providing new insights into the role of CXCR4/CXCL12 interactions in tumor progression.
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PMID:The chemokine receptor CXCR4 is regulated by DNA methylation in pancreatic cancer. 1566 33

The clinical course of 50 patients with low-grade glioma (31 male, 19 female) undergoing surgery at a single Institution from 1992 to 1996 was analyzed in relationship with known prognostic factors as far as time to tumor progression (TTP) and survival time (ST) are concerned. Moreover, microvessel density (MVD) and expression of the angiogenesis-related chemokine CXCL12 were investigated in surgical specimens. Age at diagnosis ranged from 1 to 68 years (median 30). Histology revealed 11 fibrillary, 6 protoplasmatic, 5 gemistocytic astrocytoma, 18 oligoastrocytoma and 10 oligodendroglioma. Mean follow-up was 86 months. Four patients were lost to follow-up. Of the remaining 46, twenty-four have shown disease progression and 14 have died. Median overall survival was not achieved; an estimated 75% percentage of survivors was found at 78 months. Complete gross tumor removal was associated to a longer TTP (P = 0.04 logrank). Of the investigated immunohistochemical parameters, while MVD was not predictive of subsequent TTP, expression of CXCL12 was associated with a significantly shorter TTP (P = 0.01 logrank): this predictive value remained significant (P = 0.02) at multivariate analysis. The data suggest the possible prognostic value for CXCL-12 (an angiogenesis- and tumor-growth-related chemokine) on TTP in low-grade gliomas.
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PMID:CXCL12 expression is predictive of a shorter time to tumor progression in low-grade glioma: a single-institution study in 50 patients. 1613 25

Signals from the microenvironment have a profound influence on the maintenance and/or progression of hematopoietic and epithelial cancers. Mesenchymal or marrow-derived stromal cells, which constitute a large proportion of the non-neoplastic cells within the tumor microenvironment, constitutively secrete the chemokine stromal cell-derived factor-1 (SDF-1/CXCL12). CXCL12 secretion by stromal cells attracts cancer cells, acting through its cognate receptor, CXCR4, which is expressed by both hematopoietic and nonhematopoietic tumor cells. CXCR4 promotes tumor progression by direct and indirect mechanisms. First, CXCR4 is essential for metastatic spread to organs where CXCL12 is expressed, and thereby allows tumor cells to access cellular niches, such as the marrow, that favor tumor-cell survival and growth. Second, stromal-derived CXCL12 itself can stimulate survival and growth of neoplastic cells in a paracrine fashion. Third, CXCL12 can promote tumor angiogenesis by attracting endothelial cells to the tumor microenvironment. CXCR4 expression is a prognostic marker in various types of cancer, such as acute myelogenous leukemia or breast carcinoma. Promising results in preclinical tumor models indicate that CXCR4 antagonists may have antitumor activity in patients with various malignancies. Collectively, these observations reveal that CXCR4 is an important molecule involved in the spread and progression of a variety of different tumors. As such, CXCR4 antagonists, although initially developed for treatment of AIDS, actually may become effective agents for the treatment of neoplastic disease.
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PMID:CXCR4: a key receptor in the crosstalk between tumor cells and their microenvironment. 1626 11

The chemokine receptor CXCR4 is involved in the growth and metastasis of tumor cells. However, the expression of its ligand, the chemokine CXCL12, in tumors and its role in regulating the accumulation of immune cells within the tumors is not clear. Using ELISA and immunohistochemistry we found that CXCL12 is expressed in the majority of nonsmall cell lung cancer tissue sections obtained from stage IA to IIB nonsmall cell lung cancer patients undergoing operation. Histopathologic examination of these sections indicated that high CXCL12 expression correlated with increased tumor inflammation. In addition, disease recurrence rates in a subgroup of adenocarcinoma patients showed a tendency to correlate with high CXCL12 expression in the tumor. Isolation of adenocarcinoma-infiltrating immune cells demonstrated an increase in the percentage of CD4+CD69+CXCR4+ T cells as compared with normal lung tissue. About 30% of these cells expressed the regulatory T cell markers CD25high and FoxP3. The percentage of CD8 T cells within the tumor did not change, however; the percentage of NK and NK T cells was significantly reduced. In correlation with CXCR4 expression, CD4 T cells showed increased migration in response to CXCL12 compared with CD8 T cells and NK cells. Overall, these observations suggest that CXCL12 expression may influence tumor progression by shaping the immune cell population infiltrating lung adenocarcinoma tumors.
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PMID:CD4+CXCR4highCD69+ T cells accumulate in lung adenocarcinoma. 1708 13

The p53 tumor suppressor acts as a major barrier against cancer. To a large extent, this is due to its ability to maintain genome stability and to eliminate cancer cells from the replicative pool through cell-autonomous mechanisms. However, in addition to its well-documented functions within the malignant cancer cell, p53 can also exert non-cell-autonomous effects that contribute to tumor suppression. We now report that p53 can suppress the production of the chemokine SDF-1 in cultured fibroblasts of both human and mouse origin. This is due to a p53-mediated down-regulation of SDF-1 mRNA, which can be exacerbated on activation of p53 by the drug Nutlin-3. SDF-1 promotes the migration and invasiveness of cells that express its cognate receptor CXCR4. Indeed, medium conditioned by p53-deficient fibroblasts induces cancer cells towards increased directional migration and invasiveness, which are largely reversed by CXCR4 antagonist peptides. Because SDF-1 produced by stromal fibroblasts plays an important role in cancer progression and metastasis, our findings suggest that the ability of p53 to suppress stromal SDF-1 production may be an important mechanism whereby it does its non-cell-autonomous tumor suppressor function.
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PMID:p53 Attenuates cancer cell migration and invasion through repression of SDF-1/CXCL12 expression in stromal fibroblasts. 1710 3


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