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

The given data indicate the presence of a negative correlation between metabolic indices (a decrease of the tolerance to glucose, increase of the blood level of free fatty acids, insulin, cholesterol triglycerides, cortisol, stc) and the indices of cellular immunity, which is determined by the number of rosette-forming cells and blasttransformation reaction to PHA and skin tests. Accordingly, the administration of an antidiabetic drug-phenformin (phenetylbiguanide)--apart from the improvement of metabolic pattern, results in the restoration of the cell-mediated immunity indices. These findings provide a basis for stating the phenomenon of metabolic immunodepression. The metabolic immunodepression may be supposed to prevent immunological surveillance activation, which normally is realized through the signals, provided by cells subjected to somatic mutation. It is noteworthy that the given metabolic conditions (hypercholesterinemia, hyperinsulinemia, the enhanced utilization of free fatty acids) promote the division of somatic cells. Thus, the same metabolic shifts which increase the pull of proliferating cells and, accordingly, increase the possibility of mutation development, also cause the metabolic immunodepression at the same time. These opposite metabolic influences on somatic cells and T-dependent lymphocytes cause the development of the syndrome of cancrophilia. The syndrome of cancrophilia normally arises at pregnancy, in intensive growth of the organism in childhood, accelerated development, stress and during normal ageing. Many carcinogens cause the decrease of tolerance to glucose, the increase in blood-insulin level and elevation of the threshold of sensitivity of the hypothalamus to feedback suppression. This phenomenon is based on the decrease of catecholamine level in thehypothalamus in ageing, stress and the action of some carcinogens. Thus, the syndrome of cacrophilia provides the conditions for cancer development and tumor progression, besides, the tumor itself produces the metabolic shifts typical of cancrophilia. In the light of mutation-metabolic model of cancer development, it is possible to consider the fundamental factors which increase of hinder carcinogenesis.
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PMID:[Mutational-metabolic model of carcinogenesis and the progression of the neoplastic process]. 99 16

Based on the clinicopathological classification of distinct stages of tumor progression in the melanocytic system, we have investigated the in vitro growth patterns and requirements of normal melanocytes and melanocytes isolated from different lesions of melanoma progression. Normal melanocytes depend on a combination of insulin-like growth factor (IGF-I) or insulin, 12-O-tetradecanoyl phorbol-13-acetate (TPA), alpha-melanocyte stimulating hormone (alpha-MSH), and basic fibroblast growth factor (bFGF) for in vitro proliferation. Nevus cells display a reduced need for TPA and are largely independent of bFGF. Both melanocytes and nevus cells have a finite lifespan in vitro and show no spontaneous transformation, whereas melanoma cells can be grown indefinitely in vitro. Cells from primary melanomas require only IGF-I or insulin for continuous growth, and metastatic melanoma cells can proliferate in base medium without addition of any growth factors or proteins. This progressive growth autonomy is paralleled by an increased competence for endogenous growth factor production. Among these growth factors, bFGF and melanoma growth-stimulatory activity (MGSA) act in an autocrine fashion. Melanoma-derived growth factors without apparent autocrine function, such as platelet-derived growth factor A and B (PDGF-A and PDGF-B) and transforming growth factor-alpha (TGF-alpha), might still be important for melanoma growth by stimulating surrounding normal fibroblasts, endothelial cells, or keratinocytes to secrete growth-promoting factors. The significance of growth factors such as transforming growth factor-beta (TGF-beta) and melanoma-inhibiting activity II (MIA II), which have a potentially negative autocrine function, remains unknown. The successful propagation of melanocytic cells of all stages of melanoma progression has yielded valuable insight into the mechanisms of growth regulation and malignant transformation.
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PMID:In vitro growth patterns of normal human melanocytes and melanocytes from different stages of melanoma progression. 144 12

The role of peptide growth factors in neoplastic progression of transformed rat tracheal epithelial (RTE) cells was assessed by examining growth factor requirements and expression of growth factor and growth factor receptor genes in normal and transformed RTE cells. Neoplastically transformed cell lines showed decreased requirements for bovine pituitary extract, insulin, and epidermal growth factor compared to normal primary RTE cells. Neoplastic RTE cell lines expressed significantly increased levels of transforming growth factor alpha (TGF alpha) RNA and secreted TGF alpha into the media, suggesting an autocrine role for this growth factor. Increased levels of TGF alpha RNA were also observed in the preneoplastic stages of the same cell lines, indicating that increased TGF alpha expression is an early event in the multistage process of neoplastic transformation of RTE cells. TGF beta transcripts were also overexpressed in neoplastically transformed cell lines. Our studies suggest that aberrant expression of growth factors may play an important role in the development and/or maintenance of the transformed phenotype in RTE cells.
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PMID:Altered growth factor dependence and transforming growth factor gene expression in transformed rat tracheal epithelial cells. 261 81

Various human tumor tissues contain different growth factors. In some cases progression of tumors is paralleled by elevated levels of these substances in blood or in tumor tissue. There is evidence that these growth promoting peptides might stimulate tumor growth. The growth of most tumors was associated with insulin-like substances (MW 45,000). We isolated and purified a substance immunologically cross-reactive with insulin (SICRI) from human melanoma. We found the molecular weight of affinity purified SICRI to be approximately 120,000. Our in vitro experiments with human renal carcinoma cells and growth factors suggest an important role of these molecules in tumor progression.
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PMID:Growth factors in human tumors. 265 14

Monoclonal antibodies (MAbs) to the human epidermal growth factor (EGF) receptor, the type I insulin-like growth factor (IGF) receptor, and the nerve growth factor (NGF) receptor were used to study the growth regulation of malignant cells. Anti-EGF receptor MAb 425 inhibited the growth of A 431 squamous carcinoma cells which express high numbers of EGF receptors on their surfaces. Growth inhibition induced by MAb 425 was accompanied by alterations of the cell-cycle distribution of these cells, indicating the ability of a monoclonal antibody to act as a biologically active ligand. Growth stimulation of melanoma cells by EGF was unrelated to EGF receptor expression on the cell surface. Insulin- and IGF-I-induced growth stimulation of melanoma cells was inhibited by MAb alpha IR-3 which reacts with the type I IGF receptor. This result indicates that the type I IGF receptor mediated growth stimulation not only by IGF-I but also by insulin. Normal melanocytes and cells of all stages of tumor progression expressed in tissue culture the receptor for NGF, but no effect on the growth of these cells has been observed.
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PMID:Interactions between growth factor receptors and corresponding monoclonal antibodies in human tumors. 283 Dec 41

We used an octapeptide analogue of somatostatin, SMS 201-995, in dosages ranging from 150 to 450 micrograms/d administered subcutaneously in three daily doses for 1 to 16 months, to treat 22 patients with advanced malignant islet cell carcinomas. Of the 22 patients, there were 9 with gastrinomas; 3 with glucagonomas; 4 with insulinomas; 1 with ectopic production of parathyroid hormone; and 3 with mixed syndromes. The only biochemical marker in 1 patient was pancreatic polypeptide, and 1 patient had no demonstrable peptide production from the tumor. In 14 patients, dramatic decreases in the levels of circulating peptides (insulin, vasoactive intestinal polypeptide, gastrin, and glucagon) have been accompanied by major alleviations of symptoms. Steatorrhea appears to be the most significant toxicity. This analogue of somatostatin may be appropriate for use as early therapy in patients who have symptoms from syndromes related to islet cell carcinomas but in whom there is no immediate threat from tumor progression.
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PMID:Treatment of metastatic islet cell carcinoma with a somatostatin analogue (SMS 201-995). 288 85

Progressive weight loss and anorexia are frequent phenomena in cancer patients. Although cachexia is an expected occurrence in the terminal stages of nearly all malignancies, it may be a presenting sign when the tumor burden is quite small. Lipid depletion occurs out of proportion to the protein loss and accounts for most of the weight loss in cancer. Lipids, more specifically fatty acids, are the major source of fuel in mammals and may also be used in the synthesis of new cell products. Lipolysis and lipogenesis are under the influence of several important enzymes and peptide hormones that may be modulated by a variety of exogenous factors. There is evidence that cancer patients have lost the normal homeostatic responses to decreased energy intake or starvation that allow a decrease in oxygen consumption and protein sparing. An increase in Cori cycle activity or futile recycling of metabolic products occurs with a net energy expenditure rather than energy production. Clinical studies have shown that the body lipid depletion accompanying tumor progression is not solely secondary to decreased food intake and may be reproduced by the transplantation of certain noninvasive tumors to normal hosts. Elevated basal lipolysis has occasionally been seen early in tumor growth. Such findings suggest the presence of a tumor-associated factor responsible for this increase in lipid mobilization. Some of the potential mechanisms for the altered lipid metabolism seen in cancer have been discussed. Metabolic substrates may be remodeled and directed away from fuel-efficient into energy-requiring pathways. An increased energy expenditure may occur as a result of the energy costs of tumor synthesis, an uncoupling of oxidative phosphorylation, or energy-requiring futile cycling. An overall depletion of lipid may be the final outcome of the inhibition of lipid deposition. TNF/cachectin has recently been found to suppress the activity and synthesis of several key lipogenic enzymes, including lipoprotein lipase. Abnormalities in insulin secretion or sensitivity may be involved in the decrease of fat storage in malignancy. Insulin also exerts a significant antilipolytic effect by its antagonism of hormone-sensitive lipase. Mediators of lipolysis and abnormal lipid metabolism may occur in a number of clinical conditions and include ectopic hormone production, growth factors, and tumor-associated lipolytic factors (lipid mobilizing factor, toxohormone).
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PMID:Fat metabolism and cancer. 353 75

Tumor progression in the human melanocyte system can be delineated into 6 sequential stages. The first three steps represent nonmalignant melanocyte lesions from focal proliferations of structurally normal melanocytes to lesions with architectural and cytologic atypia. Primary melanoma may be divided into radial growth phase without competence for metastasis and vertical growth phase with metastatic competence. Melanocytes isolated from normal skin, nonmalignant pigmented lesions, and melanomas and maintained in culture have properties that are characteristic for each stage of tumor progression. Cytogenetic studies revealed nonrandom chromosomal abnormalities of advanced melanomas involving chromosomes 1, 6, and 7. Recent progress in tissue culture techniques has allowed studies of growth regulation of normal and malignant cells. Six growth factor receptor-growth factor systems seem to be of biologic significance in the melanocyte system: EGF, NGF, FGF, PDGF, insulin, and beta-TGF. Monoclonal antibodies have characterized a large number of antigens on melanocytes of the various stages of tumor progression, making melanoma one of the most widely studied human tumor systems.
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PMID:Biology of tumor progression in human melanocytes. 355 33

Subcutaneous adipose tissue was examined in 77 patients with breast cancer, 61 patients with lung cancer and in a control group of 23 male and 27 female with non-tumor pathology; the weight and age of controls matched those of cancer patients. The obesity in breast cancer patients was of the hypertrophic type, and of combined type (hypertrophic-hyperplastic) in patients who were more than 50% overweight. The increased level of adipose tissue in lung cancer patients was mostly due to the larger size of adipocytes. The concentration of unsaturated fatty acids in adipose tissue in breast cancer patients was in direct correlation with the level of this tissue and adipocyte size, while, in lung cancer group, this correlation was reversed. There was no inverse correlation between the size and c-AMP level of adipocytes in both cancer groups. Resistance to the inhibitory effect of glucose on lipolysis occurring in adipose tissue was more frequent in cancer patients than in controls. Antilipolytic effect of insulin in subcutaneous adipose tissue of breast cancer patients was less pronounced than in lung cancer group. Liposynthetic activity in adipose tissue was identical in all study groups. Lipolytic activity in adipose tissue was enhanced in both cancer groups, but in the breast cancer group it was in direct correlation with overweight, while in lung cancer patients--with the degree of tumor progression.
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PMID:[Morphometric and biochemical peculiarities of fatty tissue in patients with cancer of the breast and lung]. 630 31

Proliferation and proto-oncogene expression in 19 meningiomas of typical and atypical histology were analyzed in an attempt to understand the mechanism of growth that characterizes the neoplastic process in these tumors. Proliferation was estimated as the proliferative index by the enumeration of S-phase cells in imprints of tumor tissue exposed to bromodeoxyuridine in vitro, and the gene expression of c-myc, c-fos, c-src, c-H-ras, N-myc, acidic and basic fibroblast growth factor, insulin-like growth factors I and II, platelet-derived growth factor-alpha, and epidermal growth factor was quantified by messenger ribonucleic acid dot-blot hybridization assay. Atypical and malignant tumors had significantly higher proliferative indexes than did their nonmalignant counterparts. Levels of c-myc and c-fos messenger ribonucleic acid were elevated more than fivefold in 72 and 78% of the tumors, respectively, relative to the lowest levels detected in the series. Levels of growth factor messenger ribonucleic acid were sporadically elevated; 37 to 44% of tumors had more than fivefold enhanced levels of acidic and basic fibroblast growth factor. Positive correlations between proliferation and proto-oncogene/growth factor expression were found for c-myc in atypical/malignant tumors and for epidermal growth factor in fibroblastic meningiomas. Deregulated expression of c-myc and c-fos common to both typical and atypical tumors suggests that these are early events in the meningioma tumor process that may disturb the control of cell differentiation and together with fibroblast growth factors are likely to endow the transformed cell with a selective growth advantage by reducing the requirement for exogenous mitogens and by providing a niche for the growth of the tumor clone. Positive correlation of c-myc levels with proliferation in atypical/malignant meningiomas implies that this is a feature of malignancy and indicates continued disruption of the negative regulation of proto-oncogene expression, perhaps by tumor suppressor gene losses, during the course of tumor progression.
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PMID:Correlation of proto-oncogene expression and proliferation and meningiomas. 813 92


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