Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A comparative study has been performed on the relationship between vitamin E and immunofunction in normal and malignant condition in human and murine systems. Further, the effects of supplemental vitamin E on tumor take, host survival and tumor growth have been studied in a transplantable lymphoma in mice. Vitamin E was assayed in serum samples from normal subjects and from patients with leukemia and lymphoma by high performance liquid chromatography (HPLC). The murine group included Dalton's ascitic lymphoma (DL), Schwartz lymphoblastic leukemia (SVL) and Moloney lymphoblastic leukemia (MVL). Serum vitamin E was found to be lower than that of the normal controls in all cases of leukemia and lymphoma both in human and animal system. The levels of immunoglobulins (IgG and IgM) were found to be higher in mice with leukemia and lymphoma. Supplementary vitamin E administered at the initial phase of development of murine lymphomas reduced the rate of tumor growth, improved host survival and elevated serum vitamin E level. Vitamin E supplementation also activated specific mitogen induced blastogenesis of peripheral blood lymphocytes (PBL) and elevated serum IgG level. IgM remained unaltered and macrophage activity did not seem to be affected. The present findings indicated a low status of vitamin E in tumor bearing host and a beneficial effect of supplemental vitamin E on the host which was mediated by the host immune system.
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PMID:Vitamin E--its status and role in leukemia and lymphoma. 827 50

A significant change of vitamin E and malondialdehyde plasma concentrations was reported in breast cancer patients. This change was unexpected because vitamin E was higher and malondialdehyde lower in cases than in controls, and the difference was more significant in young rather than older women. The first aim of this study was to determine whether these changes were associated only with breast cancer, or with hormone-related cancers, and/or cancers associated with nutritional risk factors or with all types of cancers. Measurements were performed before therapy on 269 hospital-based controls and on 146 patients with various carcinomas. Vitamin E:total cholesterol increased and malondialdehyde plasma concentration decreased with tumor size and progression, without relation to the site. The second aim was to understand the difference in the change observed between young and old breast cancer patients. These analytes were measured in 365 breast cancer patients according to three prognosis factors: pathology, tumor size and estrogen receptors. Vitamin E:total cholesterol significantly decreased with estrogen receptor amount. Malondialdehyde plasma concentration decreased with severity of pathology and tumor size. Together, these data support the association of an altered oxidant-antioxidant profile in cancer patients with tumor growth and progression.
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PMID:Oxidant-antioxidant status alterations in cancer patients: relationship to tumor progression. 864 57

Sundry mevalonate-derived constituents (isoprenoids) of fruits, vegetables and cereal grains suppress the growth of tumors. This study estimated the concentrations of structurally diverse isoprenoids required to inhibit the increase in a population of murine B16(F10) melanoma cells during a 48-h incubation by 50% (IC50 value). The IC50 values for d-limonene and perillyl alcohol, the monoterpenes in Phase I trials, were 450 and 250 micromol/L, respectively; related cyclic monoterpenes (perillaldehyde, carvacrol and thymol), an acyclic monoterpene (geraniol) and the end ring analog of beta-carotene (beta-ionone) had IC50 values in the range of 120-150 micromol/L. The IC50 value estimated for farnesol, the side-chain analog of the tocotrienols (50 micromol/L) fell midway between that of alpha-tocotrienol (110 micromol/L) and those estimated for gamma- (20 micromol/L) and delta- (10 micromol/L) tocotrienol. A novel tocotrienol lacking methyl groups on the tocol ring proved to be extremely potent (IC50, 0.9 micromol/L). In the first of two diet studies, experimental diets were fed to weanling C57BL female mice for 10 d prior to and 28 d following the implantation of the aggressively growing and highly metastatic B16(F10) melanoma. The isomolar (116 micromol/kg diet) and the Vitamin E-equivalent (928 micromol/kg diet) substitution of d-gamma-tocotrienol for dl-alpha-tocopherol in the AIN-76A diet produced 36 and 50% retardations, respectively, in tumor growth (P < 0.05). In the second study, melanomas were established before mice were fed experimental diets formulated with 2 mmol/kg d-gamma-tocotrienol, beta-ionone individually and in combination. Each treatment increased (P < 0.03) the duration of host survival. Our finding that the effects of individual isoprenoids were additive suggests the possibility that one component of the anticarcinogenic action of plant-based diets is the tumor growth-suppressive action of the diverse isoprenoid constituents of fruits, vegetables and cereal grains.
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PMID:Isoprenoids suppress the growth of murine B16 melanomas in vitro and in vivo. 916 84

Polyunsaturated fatty acids (PUFA) have a selective cytotoxic/cytostatic effect on a number of tumor cell lines in culture. Although this process may be enhanced by the addition of iron there is a minimum level of PUFA necessary for potentiation of cell death. Vitamin E blocks PUFA cytotoxicity when added up to 5 days after fatty acid administration. Levels of thio-barbiturate reactive material (TBARM) in the medium rise in parallel with cell death. However, they are not affected by small alterations in temperature or oxygen tension. Incubating cells with PUFA causes marked alterations in the fatty acid patterns of both neutral and phospholipid fractions. Membrane fluidity is increased and the activity of membrane-bound receptors may be influenced directly or through the actions of eicosanoids derived from the exogenous fatty acid. PUFA may be an effective way of influencing tumor growth and a safe approach for the management of human cancer.
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PMID:Mechanisms of the selective cytotoxic actions of certain essential fatty acids. 954 2

Alpha-tocopheryl succinate (alpha-TOS), a redox-inactive analogue of vitamin E, is a strong inducer of apoptosis, whereas alpha-tocopherol (alpha-TOH) lacks apoptogenic activity (J. Neuzil et al., FASEB J., 15: 403-415, 2001). Here we investigated the possible antineoplastic activities of alpha-TOH and alpha-TOS and further explored the potential of alpha-TOS as an antitumor agent. Using nude mice with colon cancer xenografts, we found that alpha-TOH exerted modest antitumor activity and acted by inhibiting tumor cell proliferation. In contrast, alpha-TOS showed a more profound antitumor effect, at both the level of inhibition of proliferation and induction of tumor cell apoptosis. alpha-TOS was nontoxic to normal cells and tissues, triggered apoptosis in p53(-/-) and p21(Waf1/Cip1(-/-)) cancer cells, and exerted a cooperative proapoptotic activity with tumor necrosis factor-related apoptosis-inducing ligand (Apo2 ligand) due to differences in proapoptotic signaling. Finally, alpha-TOS cooperated with tumor necrosis factor-related apoptosis-inducing ligand in suppression of tumor growth in vivo. Vitamin E succinate is thus a potent and highly specific anticancer agent and/or adjuvant of considerable therapeutic potential.
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PMID:Vitamin E succinate is a potent novel antineoplastic agent with high selectivity and cooperativity with tumor necrosis factor-related apoptosis-inducing ligand (Apo2 ligand) in vivo. 1189 20

Epidemiological and animal studies have indicated that consumption of green tea and high vitamin E intake are associated with a reduced risk of developing certain forms of cancer. However, the inhibitory mechanism of green tea catechins and vitamin E in angiogenesis, an important process in tumor growth, has not been well established. In the present study, alpha-tocopherol and several major catechins of green tea (catechin, epicatechin, epicatechin gallate, epigallocatechin, and epigallocatechin gallate) were tested for their ability to inhibit tube formation in vitro using a model in which human microvascular endothelial cells were exposed to a constant rate of a physiologically low level of H2O2. In this model, the production of interleukin (IL)-8 by human microvascular endothelial cells at a low level of H2O2 was required for angiogenesis, as assessed by tube formation in three-dimensional gel in culture. Vitamin E (d-alpha-tocopherol, 40 microM) in the culture media significantly reduced IL-8 production and angiogenesis. Among the green tea catechins, epigallocatechin (0.5-1 microM) was the most effective in reducing IL-8 production and inhibiting angiogenesis. These results suggest that consumption of green tea catechins or supplemental intake of vitamin E may have preventive effects on tumor development, mediated, at least in part, through inhibition of angiogenesis via suppression of IL-8 production.
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PMID:Green tea catechins and vitamin E inhibit angiogenesis of human microvascular endothelial cells through suppression of IL-8 production. 1209 14

BACKGROUND: Supplementing mice with high levels of dietary n-3 polyunsaturated fatty acids (PUFAs) increases the n-3 PUFAs in cell membranes, increases the susceptibility of the cells for lipid peroxidation (LPO) and decreases the growth rate of mammary and other tumors. However, the results of an earlier study indicated that a factor in addition to LPO was involved in the reduction in tumor growth in n-3 PUFAs fed mice. Athymic mice bearing MDA-MB-231 human breast carcinoma xenografts, were fed fish oil concentrate (FOC) or control diets, with and without supplemental Vitamin E (2000 IU /kg diet) and were sacrificed both before and after doxorubicin (DOX) treatment to evaluate factors involved in tumor growth suppression. RESULTS: Prior to DOX, basal LPO in the tumor of 3% FOC fed mice was slightly higher than in the control fed mice and was decreased in mice consuming FOC with vitamin E. Vitamin E suppressed the DOX induced increase in LPO in the tumors of control mice, however, vitamin E was not sufficient to suppress a DOX induced increase in LPO in the tumors of FOC fed mice. The mean growth rate of tumors of FOC fed mice was significantly less than the mean growth rate of the tumors of control mice. Multiple regression analyses indicated that suppression of glutathione peroxidase (GPX) activity by FOC prior to DOX therapy was more important than increased LPO as an explanation of tumor growth suppression. Tumor induced cachexia was decreased in mice consuming FOC. CONCLUSIONS: It appears that the increased sensitivity to DOX was related to an FOC induced reduction in GPX activity. FOC reduced tumor induced cachexia.
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PMID:Role of lipid peroxidation and antioxidant enzymes in omega 3 fatty acids induced suppression of breast cancer xenograft growth in mice. 1229 73

Prostate cancer is a major cause of cancer death and morbidity in western countries. However, because of its intrinsic nature of chemoresistance, there is only limited systemic therapy available for the patients. Vitamin E (VE) has been under intensive study as a chemopreventive agent for various types of cancers. Preclinical studies suggest that vitamin E succinate (VES) is the most effective antitumor analogue of VE, yet there are scarce studies of VES in prostate cancer. In this study, we investigated the effects of VES on a panel of prostate cancer cells, and a xenograft model of prostate cancer. Our results indicate that VES significantly inhibited proliferation and induced apoptosis of prostate cancer cell lines in a dose and time dependent manner. The results of microarray analysis followed by real-time RT-PCR and inhibitor analyses indicated that the VES-induced apoptosis is mediated by caspase-4 in prostate tumor cells. In our animal model of prostate cancer in SCID mouse, daily injection of VES significantly suppressed tumor growth as well as lung metastases. These results suggest a potential therapeutic utility of VES for patients with prostate cancer.
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PMID:Vitamin E succinate suppresses prostate tumor growth by inducing apoptosis. 1638 Sep 76

The goal of these studies was to investigate the potential anticancer properties of two naturally occurring plant sources and two manufactured synthetic forms of vitamin E, i. e., RRR-alpha-tocopherol (alphaT), RRR-gamma-tocopherol (gammaT), all-rac-alpha-tocopherol (all-rac-alphaT), and all-rac-alpha-tocopheryl acetate (all-rac-alphaTAc) in breast cancer models. Vitamin E compounds were evaluated in vitro for inhibition of colony formation and induction of apoptosis in human MDA-MB-435 and MCF-7 breast cancer cells and murine 66cl-4 mammary cancer cells and in vivo for ability to reduce tumor growth and lung and lymph node metastases using the transplantable syngeneic BALB/c mouse 66cl-4-GFP mammary cancer model. gammaT inhibited colony formation and induced apoptosis in all three cancer cell lines. alphaT and all-rac-alphaT were less effective and all-rac-alphaTAc was ineffective. gammaT-induced apoptosis was correlated with activation of caspases-8 and -9 and down-regulation of protein expression of c-FLIP and survivin. In vivo study 1 analyses showed that all-rac-alphaT and all-rac-alphaTAc significantly inhibited tumor growth and inhibited both visible and microscopic size lung metastases. In vivo study 2 analyses showed that alphaT and gammaT reduced tumor growth, but only gammaT reduced tumor growth significantly in comparison to control. In conclusion, synthetic, but not natural, vitamin E exhibits promising anti-cancer properties in vivo.
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PMID:In vitro and in vivo evaluation of anticancer actions of natural and synthetic vitamin E forms. 1838 78

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ~5 fold and glucose 6-phosphate dehydrogenase activities were decreased by ~25% compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased significantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to function in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.
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PMID:Dehydroepiandrosterone supplement increases malate dehydrogenase activity and decreases NADPH-dependent antioxidant enzyme activity in rat hepatocellular carcinogenesis. 2012 70


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