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)

The influence of alternate forms of nutritional support on primary tumor growth rate, tumor DNA synthesis rate, and number of lung metastases was examined in Swiss mice bearing subcutaneously implanted Lewis lung carcinoma (LLC). From Day 14 through 22 postimplant, mice were fed by continuous intravenous infusion of dextrose/amino acid (TPN), were offered the same solution from a feeding bottle (PO), were offered a casein-based, solid diet (CASEIN), or were infused with an electrolyte (ELECT) solution while energy and nitrogen were provided from the casein diet. Tumor weight and doubling time were decreased in the PO group compared to CASEIN; however, host weight decreased by 22% in the PO group. Tumor weight and DNA synthesis were decreased in the TPN group compared to CASEIN, and host weight increased by 4.6%. The decreased rate of tumor growth in the PO group was not reflected in a decrease in DNA synthesis, perhaps a result of the circadian pattern of DNA synthesis as previously reported for LLC. The number of metastatic lung nodules was significantly decreased in both the TPN and ELECT groups compared to PO and CASEIN, suggesting that intravenous fluid load rather than nutrient intake was the causative factor. In this host-tumor system, parenteral feeding was associated with a decrease in primary tumor weight and DNA synthesis rate, maintenance of host weight, and a decrease in pulmonary metastatic disease compared to mice fed a conventional diet.
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PMID:Decreased lung metastasis and tumor growth in parenterally fed mice. 310 53

The aim of this study was to determine whether a ketogenic diet could decrease nitrogen losses in cachectic cancer patients and at the same time reduce the supply of glucose for tumor energy metabolism. Five patients with malignant disease and severe weight loss (mean 32%) were fed via a fine bore nasogastric tube. A normal diet was given for 6 d and this was followed by 7 d of an isonitrogenous, isocaloric, ketogenic diet. Both diets were well tolerated. At 7 d the mean ketone body concentration in the blood of patients fed the ketogenic diet was 1.21 +/- 0.33 mM. This ketosis was associated with a significant reduction of the concentration in blood of glucose, lactate, and pyruvate (p less than 0.05). There was, however, no significant alteration in host N balance or whole-body protein synthesis, degradation, or turnover rates. Whether the change from glucose- to fat-derived energy substrates might reduce tumor growth rates in the long term remains to be determined.
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PMID:Cancer cachexia: influence of systemic ketosis on substrate levels and nitrogen metabolism. 312 52

The influence of variations in nitrogen content of nutritional substrate available to the tumor-bearing (TB) host on tumor growth and host have not yet been completely defined. One hundred fifty-two growing Fischer 344 rats were either transplanted with a sarcoma (TB) or injected with saline (NTB, day 0), had aseptic placement of superior vena cava catheter (day 14), and were infused with total parenteral nutrition solutions (days 18-28). Isocaloric solutions (approximately 50 kcal/d) contained either 0%, 5%, 16%, 33%, 67%, 100%, 133%, or 167% of normal intake of an adequate amino acid mixture. Final tumor weight in the 5% group (23.4 +/- 3.0 g) was significantly less than tumor weights of all other groups (range: 33.3 +/- 3.3 to 42.6 +/- 11.3) (p less than 0.05). The carcasses of TB animals were slightly smaller than NTB animals but showed no major alterations in protein, fat, or water composition. This study suggests that the tumor can be starved selectively by strictly nutritional means with complex accompanying host carcass and organ changes.
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PMID:Host and tumor responses to varying rates of nitrogen infusion in the tumor-bearing rat. 312 76

We have studied the ability of branched chain amino-acid enriched total parenteral nutrition solutions to improve nutritional status without stimulating tumor growth. Protein kinetics, nitrogen balance, tumor kinetics, fractional synthetic rates of individual tissues, and albumin synthesis were compared in male Sprague-Dawley rats (125-145 g) that had either s.c. Yoshida sarcoma (n = 15) or sham implantations (n = 18). Ten days postinjection, rats were randomly assigned to 2 diet groups and given parenteral infusions of 4 days at 170 kcal/kg.body wt.day as dextrose and 2 g N/kg.body wt.day as either 19 or 50% branched chain amino acid-enriched diet. During the last 4 h of feeding, protein kinetic values were studied using a constant infusion of [14C]tyrosine. Plasma tyrosine appearance, synthesis, and breakdown were unchanged by branched chain amino acid infusion. Percentage of tyrosine flux oxidized and tyrosine oxidation decreased (P less than 0.05) and net tyrosine balance improved (P less than 0.05) in rats receiving the branched chain amino acid-enriched diet. Greater nitrogen balance and lower tumor growth rates were also found in branched chain amino acid-infused rats although not statistically significant. Tumor intracellular specific activity was significantly higher in tumor animals receiving crystalline infusions, suggesting greater tumor protein breakdown with branched chain amino acid-enriched infusion. Fractional synthetic rates of liver, muscle, and tumor were unchanged. Hence, branched chain amino acid-enriched total parenteral nutrition increases amino acid utilization for net protein synthesis principally by reducing oxidation without stimulating tumor growth.
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PMID:Effects of branched chain amino acid-enriched total parenteral nutrition on amino acid utilization in rats bearing Yoshida sarcoma. 312 86

This study evaluated whether altered insulin metabolism is a key factor behind weight loss during sarcoma growth in nongrowing mice (C57BL/6J). Fasted sarcoma-bearing mice had decreased blood glucose concentrations but unchanged levels of insulin, compared with those in pair-weighed and freely fed controls. During refeeding, insulin levels were inappropriately low for the degree of glycemia in sarcoma-bearing mice compared with those of pair-weighed and freely fed controls. Injections ip of glucose to tumor-bearing animals resulted in insulin levels comparable to postabsorptive values in healthy control animals, indicating that hypoinsulinemia in freely eating tumor-bearing animals was due to a reduced glycemic sensitivity for pancreatic insulin release. Insulin supplementation at doses [4 IU/100 g (body wt)] that increase body fat in normal animals could not protect the tumor-bearing host from progressive loss of body fat or lean tissues. Exogenous insulin in excess of endogenous insulin production did not stimulate tumor growth. Nitrogen and RNA-DNA content were significantly decreased in the quadriceps muscle of tumor-bearing mice. This reduction was independent of altered insulin levels and could not be prevented by exogenous insulin. The depressed capacity of protein synthesis in extensor digitorum longus (EDL) muscle could be entirely attributed to the state of malnutrition in tumor-bearing animals. The sensitivity and responsiveness of protein synthesis in EDL muscles to insulin were normal in tumor-bearing mice, regardless of whether exogenous insulin exerted its effect in vivo or in vitro. This study confirms insulin resistance for glucose metabolism in an experimental sarcoma animal model. Such changes are concluded to be secondary to anorexia and necessary to counteract hypoglycemia. In non-growing sarcoma-bearing mice, malnutrition and anorexia account entirely for depressed muscle protein synthesis, which is not explained by insulin resistance at the translational level. Insulin metabolism is not a key factor behind progression of wasting in sarcoma-bearing mice, but anorexia is.
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PMID:Role of insulin in development of cancer cachexia in nongrowing sarcoma-bearing mice: special reference to muscle wasting. 355 91

The reaction of nucleophilic substitution of 14-bromine derivatives of carminomycin and rubomycin with respective nitrogen-containing heterocycles yielded six novel derivatives of carminomycin and rubomycin: 14-N-imidazolyl-carminomycin, 14-carminomycyl-N-pyridinium bromide, 14-carminomycyl-N-(3-aminocarbonyl)-pyridinium chloride, 14-rubomycyl-N-(3-amino-carbonyl)-pyridinium chloride, 14-N-succinimidocarminomycin and 14-N-succinimidorubomycin. In vitro and in vivo antitumor activity of the above derivatives and three other derivatives described earlier: 14-rubomycyl-N-pyridinium bromide, 14-N-imidazolylrubomycin and 14-N-phthalimidorubomycin was studied. It was shown that in vitro all the 9 semisynthetic derivatives had a lower (by 1.5-6 times) cytostatic action on murine lymphadenosis cells NK/LI as compared to the initial antibiotics. The in vivo experiments on mice revealed that by acute toxicity the rubomycin derivatives administered intravenously were close to rubomycin, whereas the toxicity of the analogous derivatives of carminomycin was 5-17 times lower. The in vivo experiments also showed that seven out of the nine 14-N-substituted derivatives of carminomycin and rubomycin were practically deprived of antitumor activity (strain LIO-1), while 14-carminomycyl-N-pyridinium bromide and 14-N-succinimidocarminomycin inhibited the tumor growth by 40-60 per cent.
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PMID:[Synthesis and antitumor action of 14-N-substituted derivatives of rubomycin and karminomycin]. 363 31

The in vivo rates of protein synthesis were assessed in tumor tissue, skeletal muscle, and whole body of rats bearing the Walker 256 carcinosarcoma. Estimates of protein synthesis in the nontumorous tissues were compared to tumor-free controls. Changes in size of the whole animal and tumor (i.e., growth) were measured, and fractional rates of growth, synthesis, and breakdown were estimated. Muscle protein synthesis and whole-body growth were significantly reduced in rats bearing larger tumors, and both were negatively correlated with tumor size (r = -0.723 and -0.825, respectively; P less than 0.01). Furthermore, whole-body and muscle protein synthesis were positively correlated with body growth (r = 0.380 and 0.563, respectively; P less than 0.05). Tumor growth followed first-order kinetics between days 7 and 13 following implantation, with a mean rate constant of 34.3%/day for the larger tumors and 27.7%/day for the small tumors. The difference in tumor growth became statistically significant over the final 3 days of tumor volume measurements. Fractional protein synthesis was significantly lower in the larger compared to the smaller tumors (48.6 versus 84.8%/day; P less than 0.05) as measured on day 14. This finding indicates a lower protein breakdown rate for the larger tumors (14.3 versus 59.0%/day; P less than 0.01) and suggests that the process of protein breakdown could play a significant role in determining tumor size, leading support to the theory of tumors acting as nitrogen traps.
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PMID:Influence of the Walker 256 carcinosarcoma on muscle, tumor, and whole-body protein synthesis and growth rate in the cancer-bearing rat. 375 11

To investigate the effect of arginine-enriched solution on tumor growth and metastasis, rats were infused with solutions containing 5.5 and 0.66% arginine for 8 days. Infusions were started at the same time of subcutaneous transplant of Yoshida sarcoma. Arginine-rich solution suppressed tumor growth at an early stage and prevented metastases to the liver and kidney. In addition, arginine supplements enhanced the phagocytic activity of alveolar macrophages. It also resulted in maintenance of a positive nitrogen balance and prevented the increases in the levels of several amino acids observed in the control group. The suppressive effect of arginine-enriched solution on tumor growth may be due to its activation of the immunologic system, in which the phagocytic activity of macrophages probably participates.
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PMID:Evaluation of the effect of arginine-enriched amino acid solution on tumor growth. 392 15

The purpose of this study was to determine whether a branched chain amino acids (BCAA) enriched intravenous feeding would have an effect on nitrogen retention in the host tissue, without stimulating tumor growth in the malignant tumor bearing animal. NEDH/c rats with an implanted fibrosarcoma were put on one of two total parenteral nutrition regimens, one of an amino acid formula containing 25 per cent BCAA, by weight and the other containing 50 per cent BCAA. Nitrogen retention in the two tumor-bearing groups was similar, although it was 47 per cent greater than observed in the non-tumor bearing animals (p less than 0.05). Skeletal protein synthesis was significantly reduced by the presence of the tumor in rats on the 25 per cent BCAA formula (from 10.1 per cent/day to 6.1 per cent/day) but was increased to 7.9 per cent/day by the 50 per cent BCAA formula. The BCAA enriched intravenous feeding does not enhance tumor growth and supports skeletal protein synthesis, at least in this experimental model.
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PMID:Use of an intravenous branched chain amino acid enriched diet in the tumor-bearing rat. 393 97

Food intakes, body composition, skeletal muscle mass, muscle protein synthesis, and myofibrillar protein degradation were studied in normal, food-restricted (FR), and Walker 256 tumor-bearing (TB) male Sprague-Dawley rats which were exercised (E) or maintained in a sedentary state. Exercise was enforced 3 times per wk for 100 min X session-1 at 20 m X min-1 on a 13% incline for 7 wk. Tumors were transplanted 3 wk after beginning the exercise program and were allowed to grow for 29 d. Food restriction was initiated during the last 2 wk of tumor growth. Food intakes and body lipid stores were reduced in all E groups, whereas body nitrogen was reduced only in the TBS animals. All E animals had significantly higher gastrocnemius muscle/body weight ratios than their sedentary counterparts, with the greatest ratio noted for the TBE animals. Muscle protein synthesis, measured by incorporation of [3H]tyrosine into gastrocnemius muscle, was significantly depressed in both FR and TB animals. Muscle protein breakdown, estimated by urinary 3-methylhistidine excretion, was significantly elevated in TB animals and slightly increased in FR animals. The results suggest that tumor presence significantly alters protein turnover to a greater extent than elicited by food restriction alone. Additionally, although exercise may have initially protected the animal by retarding tumor growth and muscle mass depletion, in the end, the energy costs of exercise accelerated the catabolic state.
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PMID:Endurance exercise modifies cachexia of tumor growth in rats. 402 82


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