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Query: UMLS:C0027627 (metastases)
 103,950 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Conditioned media from fetal rat calvarial cultures has previously been shown to stimulate the growth of the bone-metastasizing Walker 256 carcinosarcoma cell line. In the current investigation we looked at the possibility that transforming growth factor-beta (TGF-beta), present in conditioned media, and positively correlated with resorption in vitro, may be responsible for the enhanced proliferation of Walker cells cultured in these conditioned media. Purified platelet-derived TGF-beta produced a dose-dependent growth response in Walker cells with an ED50 equal to 0.05 ng/ml. Bone-derived TGF-beta activity in conditioned media, measured by NRK fibroblast colony formation, correlated well with percentage resorption in bone cultures, and growth activity in Walker cell culture. In addition to this, the growth response normally seen with conditioned media cultures of Walker cells was significantly inhibited by the addition of anti-TGF-beta 1 neutralizing antibody. We conclude that TGF-beta is an important growth stimulatory component from fetal rat calvaria.
Clin Exp Metastasis
PMID:In vitro effects of bone- and platelet-derived transforming growth factor-beta on the growth of Walker 256 carcinosarcoma cells. 222 66

Bone is a major source of transforming growth factor-beta (TGF-beta), and a preferred target organ for metastasis of the rat Walker carcinosarcoma 256 (W256). Since chemotactic mechanisms may contribute to metastatic site specificity, we have tested the hypothesis that TGF-beta is a chemoattractant for these cancer cells. Purified platelet-derived TGF-beta elicited dose-dependent migration of W256 cells in the Boyden chamber assay with half-maximal responses (ED50) elicited by 0.12 +/- 0.01 ng TGF-beta/ml. Checkerboard analysis confirmed dependence of the response upon a concentration gradient. Conditioned media from organ cultures of bone contained TGF-beta and chemotactic activity in proportion to the extent of bone resorption. The chemotactic activity in conditioned bone culture medium and that of the purified platelet-derived TGF-beta were both inhibited after incubation with anti-TGF-beta 1. We conclude that TGF-beta, released from resorbing bone, can influence the migratory behavior of the osteotropic W256 cell line.
Invasion Metastasis 1990
PMID:Chemotactic activity of bone and platelet-derived TGF-beta for bone-metastasizing rat Walker 256 carcinosarcoma cells. 235 28

We have investigated the expression of platelet-derived endothelial-cell growth factor/thymidine phosphorylase (PD-ECGF/dThdPase) in human breast-cancer tissues by the immunocytochemical method using anti-PD-ECGF/dThdPase monoclonal antibody. Out of 100 invasive-ductal-carcinoma tissue samples, 39 (39%) were evaluated as PD-ECGF/dThdPase-positive. The expression of PD-ECGF/dThdPase was identified mainly in the cytoplasma of tumor cells. The expression of PD-ECGF/dThdPase was significantly associated with the microvessel density assessed by immunostaining to factor-VIII-related-antigen (p < 0.05). However, there was no correlation between expression of PD-ECGF/dThdPase and menopausal status, tumor size, axillary lymph-node metastases, hormone-receptor status, epidermal-growth-factor receptor, or erb-B-2-protein and p53-protein expression. We suggest that expression of PD-ECGF/dThdPase plays an important role in the promotion of angiogenesis in human breast cancer.
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PMID:Expression of platelet-derived endothelial cell growth factor/thymidine phosphorylase in human breast cancer. 754 28

A malignant cell population needs the development of microvessels in order to grow and metastasize. Recently, a role for the p53 gene in the regulation of this angiogenic process has been suggested. Wild-type p53 is involved in the secretion of Trombospondin-1 (TSP-1), an angiogenesis inhibitor. Mutations of the p53 gene cause a downregulation of TSP-1 mRNA in cell lines. Mutant p53 also upregulates the expression of vascular endothelial cell growth factor, a potent angiogenic factor. Together with the reported association of p53 protein overexpression and microvessel density (MVD) in head-and-neck squamous-cell carcinoma, these in vitro findings led us to investigate whether this association would also apply in colorectal adenocarcinomas. Structural changes of the p53 gene are the most frequent observed mutations in colorectal carcinoma and are suspected to be involved in the carcinogenesis at a relatively early stage. Parallel tissue sections from primary colorectal adenocarcinomas were immunostained for CD31, an endothelial cell marker, and with DO7, recognizing both mutant and wild-type p53 protein overexpression. The presence of p53 protein overexpression was found to be significantly associated with high MVD in the vascular hot spots. Our results are in accordance with the in vitro studies on the involvement of p53 in angiogenesis. Mutant p53 might stimulate tumor angiogenesis both indirectly, by augmenting the tumor cell proliferation, and directly, by upregulating angiogenic factors and downregulating angiogenic inhibitors.
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PMID:Correlation of intratumoral microvessel density and p53 protein overexpression in human colorectal adenocarcinoma. 877 72

Physiologically, angiogenesis in adults is a controlled process which plays a role, for example, in wound healing. Pathological angiogenesis is observed in tumor formation and represents a multifactorial process, in which specific angiogenic factors, as well as growth factors, extracellular matrix proteins and cell adhesion molecules are involved. Tumor growth is characterized by an imbalance in favor of angiogenic over angiogenesis-inhibiting factors. Some of the most frequently examined angiogenic factors are vascular endothelial growth factor, acidic/basic fibroblast growth factors and the platelet-derived endothelial cell growth factor. The most important angiogenesis inhibitors are angiostatin and thrombospondin. To date, the clinical relevance of tumor angiogenesis has been shown for several human tumors. For most urological tumors, the grade of tumor vessel formation, measured as microvessel density, has been associated with metastases, tumor growth and clinical course. The prognostic value of this feature of malignant growth seems to be higher than that of most of the classical and newer prognostic factors. Systematic investigations of tumor angiogenesis are becoming increasingly relevant for diagnostic and therapeutic strategies and offer opportunities for the development of new specific therapeutic approaches in clinical oncology.
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PMID:[Angiogenesis--principles and significance in urologic tumors]. 899 26

Human head and neck squamous cell carcinoma (HNSCC) cell cultures were established to identify the angiogenic factors they produced and how these factors contribute to two steps of the angiogenic process: endothelial cell proliferation and migration. The HNSCC cells secreted vascular endothelial cell growth factor (VEGF), transforming growth factor-beta (TGF-beta) and prostaglandin E2 (PGE2), but only low levels of basic fibroblast growth factor. Both proliferation-stimulatory and -inhibitory cytokines were produced by the HNSCC cells, with VEGF promoting endothelial cell proliferation, prostaglandins having no effect and TGF-beta downregulating proliferation. Two methods were used to measure endothelial cell migration: migration into a wound in the endothelial cell monolayer and migration across a filter into lower compartments. HNSCC cell supernatants stimulated endothelial cell migration in both migration models. VEGF had no effect on the motility of endothelial cells. However, when TGF-beta activity in the HNSCC supernatants was neutralized with antibody or the production of prostaglandins by HNSCC cells was blocked with indomethacin, the migration-stimulatory activity in the HNSCC cell supernatants was diminished. Adding authentic PGE2 or TGF-beta 1 to endothelial cells mimicked the migration-stimulatory activity of the HNSCC supernatants. Thus, HNSCC-derived VEGF is important in stimulating endothelial cell proliferation, while the antiproliferative effect of TGF-beta and the migration-stimulatory activity of TGF-beta and PGE2 suggest their having a role in the morphogenic processes of angiogenesis.
Invasion Metastasis 1996
PMID:Regulation of the steps of angiogenesis by human head and neck squamous cell carcinomas. 937 Dec 28

Thymidine phosphorylase (TdRPase) is an enzyme involved in the pyrimidine metabolism. It was reported that many cancers contained higher levels of TdRPase than normal tissues. And TdRPase has been reported to be identical with the platelet-derived endothelial cell growth factor. To clarify the distribution of TdRPase in primary and metastatic colorectal cancer, we carried out immunohistochemical staining of formalin-fixed specimens. We investigated 35 primary colorectal cancers resected surgically, 27 hepatic metastases and 8 lung metastases from colorectal carcinoma. TdRPase was highly expressed in primary colorectal cancer with lung metastases (100.0%) and surgically resected lung metastases cancer (87.5%). The staining correspondence between primary colorectal cancer and metastases was 19 cases (70.4%) in the liver metastases and 7 cases (87.5%) in the surgically resected lung metastases. The above results suggested that immunohistochemical staining for primary colorectal cancer may provide information about the sensitivity of metastases to the chemotherapy.
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PMID:[Immunohistochemical staining of thymidine phosphorylase in primary colorectal carcinoma and metastases]. 949 28

Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor and has angiogenic activity. In this study, we investigated the expression of dThdPase in ductal adenocarcinoma of the pancreas and examined the correlation between dThdPase expression and clinicopathological factors and clinical outcome. dThdPase expression was demonstrated by immunohistochemistry in the cytoplasm of tumor cells in 59% of the 54 patients studied. The expression of dThdPase correlated significantly with a poor prognosis (P=0.013). Significant correlations were also observed between dThdPase expression and extrapancreatic neural plexus invasion and the presence of postoperative hepatic metastases (P=0.05 and 0.03, respectively). The average microvessel count in dThdPase-positive tumors was significantly higher than that in dThdPase-negative tumors (P < 0.0001). These findings suggest that dThdPase expression in pancreatic adenocarcinoma enhances the abilities of tumor invasion and/or metastasis through its angiogenic properties.
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PMID:Expression of thymidine phosphorylase is associated with a poor prognosis in patients with ductal adenocarcinoma of the pancreas. 967 35

Thymidine phosphorylase (Th.P) is an angiogenic factor shown to induce endothelial cell migration and proliferation. On the other hand, loss of wild type p53 function leads to down-regulation of thrombospondin-1, an inhibitor of angiogenesis. In this immunohistochemical study we investigated the intratumoural angiogenesis and thymidine phosphorylase (Th.P) expression in paraffin-embedded bioptical material from 104 locally advanced squamous cell head and neck cancers. The nuclear accumulation of mutant p53 protein and the cytoplasmic expression of bcl-2 protein was also assessed. High vascular grade was observed in 56% and high Th.P tumour cell reactivity in 48% of cases. High microvessel score was associated with an increased percentage of cancer cells expressing thymidine phosphorylase (P = 0.001). Increased p53 nuclear accumulation also correlated with high vascular grade (P = 0.001). High histological grade and absence of bcl-2 overexpression were associated with lymph node involvement (P = 0.002 and P = 0.02 respectively). No correlation of clinically detected lymphadenopathy with angiogenesis and p53 was observed. We conclude that intense neo-angiogenesis in locally advanced squamous cell head neck cancer is a frequent event, which is associated with nuclear p53 accumulation and thymidine phosphorylase overexpression.
Clin Exp Metastasis 1998 Oct
PMID:Neo-angiogenesis in locally advanced squamous cell head and neck cancer correlates with thymidine phosphorylase expression and p53 nuclear oncoprotein accumulation. 993 13

Outgrowth of solid tumors and metastases is dependent on the process of angiogenesis. Tumors escape from the formation of an effective infiltrate by downregulation of endothelial adhesion molecules. This downregulation of adhesion receptors is governed by the exposure to angiogenic factors. In recent years proof for this has been provided by demonstrating that freshly isolated tumor endothelial cells exhibit a decreased expression of ICAM-1 and -2 as compared to endothelial cells in normal tissue. In addition, adhesion molecules are downregulated on normal tissue endothelial cells when cultured with angiogenesis stimulators such as basic fibroblast growth factor and vascular endothelial cell growth factor, while under these conditions endothelial cells become less responsive to cytokines such as tumor necrosis factor-alpha with respect to the upregulation of endothelial adhesion molecules. Very recently it has been demonstrated that this harmful endothelial cell anergy can be counteracted by inhibitors of angiogenesis.
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PMID:Angiogenesis modulates the tumour immune response. 1031 18


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