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

Microvascular proliferation, a hallmark of malignant brain tumors, represents an attractive target of anticancer research, especially because of the quiescent nonproliferative endothelium of the normal brain. Cerebral neoplasms sequester copper, a trace metal that modulates angiogenesis. Using a rabbit brain tumor model, normocupremic animals developed large vascularized VX2 carcinomas. By contrast, small, circumscribed, relatively avascular tumors were found in the brains of rabbits copper-depleted by diet and penicillamine treatment (CDPT). The CDPT rabbits showed a significant decrease in serum copper, copper staining of tumor cell nuclei, microvascular density, the tumor volume, endothelial cell turnover, and an increase in the vascular permeability (breakdown of the blood-brain barrier), as well as peritumoral brain edema. In non-tumor-bearing animals, CDPT did not alter the vascular permeability or the brain water content. CDPT also inhibited the intracerebral growth of the 9L gliosarcoma in F-344 rats, with a similar increase of the peritumoral vascular permeability and the brain water content. CDPT failed to inhibit tumor growth and the vascularization of the VX2 carcinoma in the thigh muscle or the metastases to the lung, findings that may reflect regional differences in the responsiveness of the endothelium, the distribution of copper, or the activity of cuproenzymes. Metabolic and pharmacologic withdrawal of copper suppresses intracerebral tumor angiogenesis; angiosuppression is a novel biologic response modifier for the in situ control of tumor growth in the brain.
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PMID:Inhibition of angiogenesis and tumor growth in the brain. Suppression of endothelial cell turnover by penicillamine and the depletion of copper, an angiogenic cofactor. 170 Jun 17

Tumor angiogenesis is a very important process for growth and proliferation of most solid tumors. It insures the delivery of feeding molecules as well as the elimination of degradation products and allows tumoral cells to escape from the primary tumor site and the further establishment of metastases. Tumor neovascularisation is the result of a cascade of events primarily related to the properties of endothelial cells of capillaries. The main steps are: a) degradation of capillary basal lamina and destruction of the surrounding tissues, b) endothelial cell proliferation and c) endothelial cell migration towards the tumor site. A number of substances either synthetic or of natural origin are known to stimulate one of the above mentioned steps and/or to induce the production of factors which, in turn, stimulate one or several steps of the cascade. Such molecules can also be synthesized by tumoral cells; indeed they have often been evidenced in the fluids surrounding the tumor site. Many factors remain to be identified and their mechanism of action wait to be elucidated. However, it is already clear that several molecules are involved in the various steps of tumor angiogenesis. They display a coordinated sequential action and their synthesis is induced and controlled by the tumor itself. Amongst others, the following molecules play a role in tumor angiogenesis: degradative enzymes, E-prostaglandins, specific oligopeptides, fibronectin and heparin. Furthermore, several metal cations are also involved in tumor angiogenesis.
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PMID:[Tumor angiogenesis]. 242 24

We analysed the growth pattern of metastases in C3H-mice produced by i.v. injection (tail vein) of tumor cell suspensions of mammary carcinoma HB. Although the ordinary Gompertz equation generally corresponds well to tumor growth in animals and men, we found it inadequate to describe the growth of lung metastases in our model. The morphometric analysis and growth kinetics (LI/GF) of the metastases show a biphasic pattern. The first phase is characterized by a strictly avascular growth and nutrition by diffusion, the second phase is initiated by tumor angiogenesis. To analyze these observations we developed a new mathematical equation which fits particularly well to the metastatic growth curve. We conclude that the present model is appropriate for the analysis of tumor angiogenesis, especially to study factors, which influence the development of a tumor specific vascular system.
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PMID:A mathematical model for metastatic growth illustrated by in vivo and in vitro growth of a transplantable mammary carcinoma in mice. 242 82

The role of host mast cells in tumor-associated angiogenesis was investigated by comparing the angiogenic response of genetically mast-cell-deficient W/Wv mice and mast-cell-sufficient +/+ littermate mice to s.c. growing B16-BL6 tumors. The angiogenic response was found to be slower and initially less intense in W/Wv mice than in +/+ mice. Fewer W/Wv mice than +/+ mice developed spontaneous lung metastases and W/Wv mice exhibited fewer lung metastases per mouse. Bone-marrow repair of the mast-cell deficiency restored the angiogenic response of W/Wv mice and also restored the incidence of hematogenous metastases to approach that of +/+ mice. Differences in lymphatic metastasis were not detected between W/Wv and +/+ mice. These results demonstrate a role for mast cells in vivo during tumor angiogenesis, and suggest a role also for host mast cells in hematogenous metastasis.
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PMID:Mast-cell-deficient W/Wv mice exhibit a decreased rate of tumor angiogenesis. 245 91

More than 30% of the colony formation of dispersed tumor cells was inhibited by medroxyprogesterone acetate (MPA) in 2 out of 6 cases of endometrial cancer, in 1 out of 6 cases of cervical cancer, and in 3 out of 12 cases of ovarian cancer. The colony formation inhibited by MPA was not related to clinical stage or histological type. There was no significant difference in the tumor angiogenesis factor (TAF) activity of any case of endometrial, cervical and ovarian cancer between the cortisol-treated group and the controls. TAF activity was inhibited by MPA in 4 out of 6 cases of endometrial cancer, in 5 out of 6 cases of cervical cancer, and in 9 out of 12 cases of ovarian cancer. There was no significant difference in the fibroblast growth factor (FGF) activity of any case of endometrial, cervical and ovarian cancer between the cortisol-treated group and the controls. FGF activity was inhibited by MPA in 3 out of 6 cases of endometrial cancer, in 5 out of 6 cases of cervical cancer, and in 10 out of 12 cases of ovarian cancer. The cases in which the colony formation was inhibited by MPA were not related to the cases in which TAF or FGF activity was inhibited by MPA. Therefore, MPA may reduce neovascularization induced by TAF and FGF, and can depress secondary spreading of some endometrial, cervical and ovarian cancer via the mechanism of terminal process of secondary spreading, regardless of the presence of glucocorticoid actions similar to that of cortisol, and the reduction of cell proliferation.
Invasion Metastasis 1989
PMID:Inhibition of tumor angiogenesis activity by medroxyprogesterone acetate in gynecologic malignant tumors. 247 53

We examined the effect of medroxyprogesterone acetate (MPA) on secondary spreading of endometrial cancer. There was no significant difference in the adhering capacity of dispersed Ishikawa cells (derived from well-differentiated endometrial cancer) to a cell basement membrane matrix, fibronectin or laminin between cells treated with MPA, with cortisol, and without treatment. The adhering capacity of cells treated with cortisol to collagen type IV was higher than that without treatment. However, the adhering capacity was little affected by treatment with MPA. These results indicate that although cortisol may induce the initial process of metastasis by inducing the attachment of tumor cells to the basement membrane of vascular endothelium, MPA has no influence on the attachment, although it has a glucocorticoid action similar to that of cortisol. There was no significant difference in tumor angiogenesis factor (TAF) or fibroblast growth factor (FGF) activity of the tumor extract from Ishikawa cell colonies between cortisol-treated and control group. TAF or FGF activity of the MPA-treated group was lower than that of the control group. MPA may reduce the neovascularization in the terminal process of metastasis via the reduction of TAF and FGF produced by tumor cells, in spite of its glucocorticoid action.
Invasion Metastasis 1989
PMID:Effect of medroxyprogesterone acetate on secondary spreading of endometrial cancer. 252 39

We have studied biologically active substances, tumor angiogenesis factors (TAF), which are supposed to be associated with the proliferation and metastases of choriocarcinoma cells. Eight human choriocarcinoma cell lines were used in the present study. TAF activity was assayed by bioassays using BALB/c mice subcutaneous tissue, chicken chorioallantoic membrane (CAM) and rabbit cornea in vivo and by proliferation of endothelial cells in vitro. 1. We found a positive correlation between the size of tumors developed in xenotransplantation and the number of blood vessels in the tumor tissues. A correlation between the number of blood vessels and TAF activity was also found. 2. With a gel-filtration method, TAF activity was observed in the common fractions in every cell line. The molecular weight of TAF was more than 10,000 daltons. 3. There was a heterogeneity of TAF activity among the cell lines. From these results, it appears that TAF initiates the choriocarcinoma cell-proliferation.
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PMID:[Fundamental studies on tumor angiogenesis factors with a choriocarcinoma model]. 342 90

Effective study of the malignant phenotype at the tissue level requires model systems that are intelligible both to cell biologists and to pathologists, and that also observe the spatial imperatives intrinsic to tissues in nature. Malignant cells commonly appear in multicellular units, and growth of tumor tissue is seen as an increase in the number of cells and multicellular units. The supporting stroma frequently has an abnormal appearance, and this component of the tissue also increases in mass as the tumor enlarges and spreads. The direction of invasion is influenced by the direction of available metabolites. Histophysiologic gradient culture complies with nature's spatial rationale, since at the substrate-parenchymal interface three functions coincide. These are anchorage, initiation of epithelial renewal, and complete exchange of metabolites. Our model system provides a setting for reconstructing and manipulating many features of the malignant phenotype seen in cancer tissues in nature, such as abnormalities in the sequence of maturation of stratified epithelium, hyperplasias, dysplasias, interaction between different types of epithelium, aggregate formation, tumor angiogenesis, and neoplastic blockade.
Cancer Metastasis Rev 1984
PMID:The propagation of cancer, a process of tissue remodeling. Studies in histophysiologic gradient culture. 656 82

Metastasis and tumor angiogenesis are invasive phenomena and share many common properties at the physiological level and some similarities at the molecular level. Each consists of repetitive cycles of interaction with adjacent extracellular matrix components by mediating cellular adhesion, matrix dissolution, and cellular motility to achieve metastasis of cancer cells or neovascularization of tumors. Molecular factors which implement this triad of events are reviewed, as are several signal transduction components which may regulate them. Some potentially promising prognostic, diagnostic, and therapeutic modalities for tumor angiogenesis and metastatic disease are also discussed.
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PMID:Molecular mediators of interactions with extracellular matrix components in metastasis and angiogenesis. 751 92

A more accurate method of detecting nodal disease in squamous cell carcinoma of the tongue is needed so that treatment of the neck with its associated morbidity can safely be reserved for patients who actually have metastatic disease. Tumor angiogenesis and the expression of the p53 antigen--which have each been shown to be predictive of metastasis in breast and colon cancer, respectively--are examined for their ability to predict neck metastasis in tongue cancer. Fifty-seven patients with T1 and T2 squamous cell carcinoma of the oral tongue, whose neck disease was examined by dissection or by 2-year follow-up, were studied. Twenty-eight patients (49%) were node positive and 29 patients (51%) were node negative. The primary tumors were immunohistochemically stained for the p53 antigen and for factor VIII, which allowed the blood vessels within the tumor to be quantitated. The mean vessel counts per x200 high-power field were 59.8 and 61.5 for node-positive and node-negative patients, respectively (p = 0.8). Node-positive patients showed overexpression of p53 43% of the time, vs. 61% for node-negative patients (p = 0.17). Multivariate analysis confirmed that no difference in tumor angiogenesis or the expression of the p53 antigen was found between tumors that had metastasized and those that had not. Therefore neither tumor angiogenesis nor the p53 tumor marker is clinically useful in determining lymph node metastasis in these patients.
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PMID:Tumor angiogenesis, the p53 antigen, and cervical metastasis in squamous carcinoma of the tongue. 752 5


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