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)

Prostaglandins and serotonin are vasoactive compounds with profound effects on the gastrointestinal tract. Both cause inhibition of gastric acid secretion (although serotonin stimulates gastric pepsin secretion), stimulation of intestinal motility, and conversion of small intestinal mucosa from absorption to secretion of water and electrolytes. Their effects on pancreatic and biliary function are still not clear. Although prostaglandins appear to elicit their effects primarily by a paracrine mode of action, and serotonin is primarily a neurotransmitter (neurocrine), it is clear that even under normal conditions both can function as humoral agents. For example, we have shown that serotonin plays a physiologic role as a humoral inhibitor of gastric acid secretion. However, the effects of these agents become more pronounced in patients with humorally mediated diarrheogenic syndromes. Serotonin (and related indoles, particularly 5-hydroxytryptophan) has been firmly implicated as a cause of diarrhea in patients with carcinoid syndrome; our recent studies suggest that the diagnosis can be more effectively made by measuring circulating immunoreactive serotonin concentrations than urinary excretion of 5-HIAA; that some circulating serotonin escapes hepatic inactivation and, thus, large intestinal tumors can cause carcinoid syndrome in the absence of hepatic metastases; and that large amounts of serotonin are produced by some noncarcinoid diarrheogenic tumors, including medullary carcinomas of the thyroid and tumors associated with the WDHA syndrome. A large number of tumors of probable neural crest origin, including medullary thyroid carcinoma, carcinoids, and tumors associated with the WDHA syndrome, secrete large amounts of prostaglandins, particularly PGE2. The clinical response of at least some of the patients harboring these tumors to inhibitors of prostaglandin synthesis (particularly indomethacin) suggests that prostaglandins play a role in the etiology of these diarrheogenic syndromes.
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PMID:Prostaglandins and serotonin: nonpeptide diarrheogenic hormones. 39 Aug 99

In a patient who had undergone surgery for a medullary carcinoma of the thyroid, and with multiple hepatic metastases and severe diarrhoea, prostaglandins PGE1, PGE2, and PGF2alpha measured in peripheral venous blood and hepatic venous blood were normal in level and closely comparable, i.e. without gradient. Arachidonic acid, a PGs precursor, labelled with Iodine 131 was not taken up in the plaques of hypofixation seen with bengal rose and technetium sulphate. Finally, aspirin and indomethacin failed to relieve the diarrhoea. It is suggested that PGs were not secreted by the hepatic metastases and could not therefore be considered responsible for the diarrhoea.
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PMID:[Proof of the absence of prostaglandin secretion by a medullary carcinoma of the thyroid with functional diarrhea]. 121 94

Prostaglandin E2 (PGE2) stimulated in vitro invasion, migration, and adherence to reconstituted basement membrane by metastatic Lewis lung carcinoma (LLC) clones, but this stimulation was blocked by protein kinase A (PKA) inhibitors and by expression of a transfected mutant RI alpha which blocks PKA activation. In vitro migration and adherence of metastatic LLC transfectants was heightened by expression of a transfected C alpha gene and further heightened by Zn2+ induction of the expression vector. Nonmetastatic LLC were not migratory nor invasive. However, nonmetastatic LLC that were stably transfected with a C alpha gene were both migratory and invasive, particularly when C alpha expression was further induced with Zn2+. The results of these in vitro studies show that PKA can enhance the metastatic characteristics of LLC.
Invasion Metastasis 1992
PMID:Activation of protein kinase A increases the in vitro invasion, migration, and adherence to reconstituted basement membrane by Lewis lung carcinoma tumor cells. 129 38

Unsaturated fatty acids of the n-6 and n-3 class have been shown to affect tumor growth and metastasis. The very long chain polyunsaturated fatty acids of the n-3 family, e.g. eicosapentaenoic acids (C20:5n-3) and docosahexaenoic acids (C22:5n-3), have an inhibiting effect on tumor growth. Metastasis is promoted by n-6 polyunsaturated fatty acids, e.g. linoleic acid (C18:2n-6) and gamma-linolenic acid (C18:3n-6). The mechanisms of promotion and inhibition are described in the present review. The mechanisms of lipid peroxidation, which appears to be an important factor in the inhibition of tumor growth, are discussed. Lipid peroxidation is induced by polyunsaturated fatty acids involving autoperoxidation a.o. and the enzymes cytochrome P450, cyclooxygenase and lipoxygenase. In tumor cells these enzymes are decreased in activity but at present the reason for this reduction is not known. Lipid peroxidation products such as hydroxyeicosatetraenoic acids (HETES), hydroperoxy eicosatetraenoic acids (HPETES) and malondialdehyde may have a regulating effect on DNA duplication enzymes (e.g. polymerases). Prostaglandin synthesis in tumor cells and macrophages is also affected by polyunsaturated fatty acids. The fish oil fatty acids are known to reduce prostaglandin synthesis by competing with arachidonic acid for the enzyme cyclooxygenase. However, fish oil fatty acids have an antagonistic effect on cyclooxygenase. Polyunsaturated fatty acids also have an effect on the immune system and particularly on macrophages. Macrophages, but also T-cells and B-cells, are inhibited by prostaglandins such as PGE2, while immunosuppressor cells are stimulated by PGE2.
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PMID:Effects of dietary fatty acid composition on tumor growth and metastasis. 144 14

The relationship of prostaglandin E2, of which a large amount is produced in various neoplasms, and hematogenous distant metastases was investigated in a total of 44 colorectal cancer patients because of its varied pathophysiologic potentials. The authors found significantly high levels of PGE2 in local venous blood draining the carcinoma and in peripheral blood in cases with liver or lung metastasis, as well as a significantly large amount of PGE2 production in the carcinoma tissue. The results suggest that increased local blood PGE2 could enhance the metastasis formation, and increased peripheral blood PGE2 may be useful in the detection of such metastasis in colorectal cancer.
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PMID:Relationship between blood plasma prostaglandin E2 and liver and lung metastases in colorectal cancer. 220 73

Prostaglandins may have both undesirable and desirable effects in malignant disease. Their possible roles in breast cancer were studied by examining the relationships between different variables and the amounts of prostaglandin-like material (PG-LM) extracted from 141 breast carcinomas. Univariate analysis indicates a direct correlation with patient age and menopausal status, with a greater yield from cancers of post- compared with pre-menopausal women. Tumours up to 2 cm diameter yielded more PG-LM than those measuring greater than 2-5 cm. Although there was also a direct correlation with bone metastasis near to the time of surgery, this was because no positive bone scans occurred in patients whose tumours yielded little total PG-LM (less than 16 ng PGE2 equivalents per g tissue). Since tumour PG-LM did not predict later spread to bone, and yields of greater than 16 ng g-1 were similar in the positive and negative bone scan groups, tumour PG-LM appears to be unimportant for skeletal metastasis. There was no obvious relationship of tumour PG-LM to the grade of malignancy, tumour type, amounts of fibrous tissue (and therefore malignant cells), invasion of blood vessels and lymphatics or presence of plasma cells. Multivariate analysis indicates that disease-free survival is longest with an intermediate production of tumour total PG-LM. Of the 82 patients now dead, the cause was attributed to metastatic disease in 69 cases. No relationship of PG-LM to the length of survival was seen with univariate or multivariate analysis. However, when just the post-menopausal patients who died within the first 3 postoperative years were analysed, there was a highly significant inverse correlation between the tumour total PG-LM and the time to death. The reason(s) for these different findings on overall survival compared with just the patients who died are not understood, but the results may indicate that one or more other variables must co-exist with a high tumour PG-LM to hasten death.
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PMID:Breast cancer, prostaglandins and patient survival. 293 Jun 91

The effect of prostaglandins (PG) E2 and F2 alpha, indomethacin and arachidonic acid on stressful metastatic stimulation observed in case of combined stress influence has been studied in C57Bl mice with Lewis carcinoma. Under conditions of excessive stress load indomethacin, arachidonic acid and PGF2 alpha stimulated the development of metastases, while PGE2 caused an inhibiting effect. On the contrary, in animals which were not affected by stress indomethacin and PGF2 alpha revealed an antimetastatic effect.
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PMID:[Effect of prostaglandins on metastatic spread after surgical removal of tumors and pain stress in mice]. 312 Dec 80

Enhanced production of prostaglandins (PGs) by experimentally-induced and naturally occurring tumors and their effect on tumor growth and immunosurveillance have been noted. Directed toward further evaluation of the relationship between prostatic tumor growth and its milieu, i.e., microenvironment, we investigated the possible correlation between levels of PGs, tumor size, and metastatic potential. For this purpose, the levels of PGE2 and PGF2 alpha in plasma and tumor effusions of three tumor sublines of the Dunning R-3327 rat prostate adenocarcinoma were measured: R-3327H, well-differentiated, slow-growing, and poorly metastatic; R-3327G, poorly differentiated, fast-growing, and poorly metastatic; and R-3327 Mat LyLu, anaplastic, fast-growing, and highly metastatic. The level of PGF2 alpha was highly variable with no significant differences being noted between the tumor sublines. The mean values of PGF2 alpha were, however, higher, although not significantly so, in the smaller tumors within each of the sublines. The levels of PGE2 were significantly higher in Mat LyLu effusions than those from the nonmetastasizing R-3327G and H sublines. Evaluation and comparison of the relationship between tumor burden, i.e., size versus levels of PGE2 and PGF2 alpha showed no significant differences. A vasodilator and regulator of immunological responsiveness, PGE2, may function as a modulator of tumor metastases. In consonance with studies by others elevated levels of PGE2 may possibly serve as a prognostic marker for the high metastatic potential of neoplastic cells.
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PMID:Immunobiology of the Dunning R-3327 rat prostate adenocarcinoma sublines: plasma and tumor effusion prostaglandins. 386 Nov 6

The immune regulation of phytohemagglutinin (PHA) and concanavalin A (Con A) mitogen responses by prostaglandin (PG)-producing suppressor monocytes was examined in 57 patients with colorectal cancer and 55 normal individuals. The blood lymphocyte responses to either PHA or Con A were significantly depressed in 74% of patients compared to normal controls. The mean PHA response for the patients was significantly lower than that for controls (17,649 versus 25,549 cpm, P = 0.02), while the mean Con A response for the patients was also depressed but not as significantly (13,551 versus 18,623 cpm, P = 0.09). The depression of immune competence was greatest in older patients and those with metastatic disease. The addition of indomethacin (1 microgram/ml) to cell cultures of both patients and normal individuals enhanced the mitogen response, suggesting that PGE-producing suppressor cells were operative in both groups. Among the patient group, however, a differential modulation of the immune response by indomethacin was observed. Thus, the addition of indomethacin restored the PHA response in patients almost to normal levels, while the Con A increase was less pronounced. Even after indomethacin treatment, the Con A proliferative response by lymphocytes was significantly depressed in patients as compared to controls (P = 0.002). To prove that indomethacin was blocking excessive PG production by suppressor monocytes in colon cancer patients, we directly measured PGE2 production by peripheral blood mononuclear cells (PBMCs) using a radioimmunoassay. PBMCs from the patients produced significantly greater amounts of PGE2 compared to controls (10.1 versus 5.1 ng/ml, P = 0.0001). This comparison was still significant after adjustment for age and sex. The increased PGE2 production appeared to be selective, since the levels of two other arachidonic acid metabolites, PGF1 alpha and thromboxane B2, were the same or less than control levels. PG-mediated immune suppression of mitogenesis thus appears to be abnormally increased in colon cancer patients, particularly for the PHA response. This abnormality was partially corrected in vitro by incubation of the PBMCs with indomethacin, a prostaglandin synthetase inhibitor.
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PMID:Prostaglandin E2-mediated suppression of cellular immunity in colon cancer patients. 622 53

A case of humoral non-parathyroid hypercalcemia in a breast cancer patient is discussed. Bone metastases developed 23 months after the first clinical evidence of increased serum calcium levels and did not appear to be etiologically involved in this case of hypercalcemia. Serum levels of I-PTH and PGE2 were normal, as were urinary c-AMP levels. Furthermore, no significant response to corticosteroid therapy was observed. However, the correlation between the activity of metastatic disease and calcemia suggests that this cancer produced humoral factor(s) with calcium-mobilizing activity.
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PMID:Humoral nonparathyroid hypercalcemia without evidence of bone involvement. 630 87


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