Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To investigate the progress of tissue protein metabolic perturbations in animals developing cancer cachexia, we analyzed an experimental model system based on a highly-deviated, transplantable ascites hepatoma of the rat (Yoshida AH-130). After inoculation, at first this tumour grew rapidly at an exponential rate, then it entered a stationary state until animal death (in about 15 days). Cessation of protein accumulation (growth) was achieved by tumour cells thanks to a combined reduction of synthesis and enhancement of protein degradation (slow-turnover protein pool); the latter was apparently operated through activation of the acidic vacuolar (lysosomal) mechanism. The body weight, net of tumour, early and progressively declined in transplanted rats. Their liver initially showed a moderate enlargement, mostly accounted for by a reduction in the protein breakdown rate; then the liver eventually atrophied, in spite of an enhanced synthetic rate, because of an even greater increase of the degradative rate. By contrast, gastrocnemius muscles started loosing weight and protein since the early phases of tumour growth; their atrophy was associated with elevation of the apparent protein degradative rate, with no change in the apparent synthetic rate. Therefore, tumour growth somehow elicited perturbations in the host tissues examined, which apparently mostly affected the catabolic side of protein turnover.
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PMID:Protein turnover states of tumour cells and host tissues in an experimental model. 357 77

Total parenteral nutrition (TPN) is a clinical adjunct to cancer therapy. But it is difficult to do controlled clinical studies on cancer patients undergoing TPN. We therefore turned to a study of TPN on Buffalo strain rats with and without a Morris 7777 transplantable hepatoma. Our results showed that TPN at higher than normal levels (total parenteral hyperalimentation, abbreviated TPH) supported a gain in body weight of nontumorous rats. In tumorous rats, TPH supported body weight gain and stimulated tumor growth. Detailed analysis showed the TPH of the rats with a large rapidly growing hepatoma did gain body weight associated with fluid retention while the carcass weight decreased. Nor did TPH of tumorous rats significantly reverse the low cell proliferative activity to ear epidermis attributed to the tumor though it did stimulate tumor cell proliferation. Thus TPH by itself did not overcome wasting due to presence of the tumor. Using the hypothesis that uncontrolled gluconeogenesis is linked to cancer cachexia, we combined TPH with inhibition of gluconeogenesis (using hydrazine sulfate) and prevented the carcass weight loss (cachexia) in the tumorous rats. Tumor growth was stimulated by this treatment. Stimulation of cell proliferation in the tumor can, however, benefit chemotherapy using an S phase or cell cycle-specific cytotoxic drug.
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PMID:Effect of total parenteral nutrition on tumor-host responses in rats. 680 28

This study was designed to investigate the effects of a growing H6 hepatoma on the intracellular element content in three distinctly different tissue cell populations of the mouse host (hepatocytes, fibroblasts, and crystal enterocytes). X-ray microanalysis measurements of the intranuclear concentrations of several elements (sodium, magnesium, phosphorus, sulfur, chlorine, and potassium) were made. Briefly, the tumor presence significantly increased intranuclear sodium concentration but not the concentration of magnesium, phosphorus, sulfur, chlorine, or potassium in three tissue cell types of mice that were anorectic and cachectic. A second aim of the study was to see if injections of the diuretic amiloride, a drug reported to block passive influx of sodium into mammalian cells, would counteract the effect of the tumor presence and lower the intranuclear concentration of sodium towards that of a non-tumor-bearing host. Amiloride did significantly lower the intranuclear level of sodium in the host tissues to that of non-tumor-bearing mice. The amiloride-caused decrease on intracellular sodium was correlated to a decreased cell proliferation activity in the tumor cells and duodenal enterocytes. A possible relationship between the intracellular concentration of sodium in tissue cells and cancer cachexia is discussed.
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PMID:Effect of cancer cachexia and amiloride treatment on the intracellular sodium content in tissue cells. 682 79

The Walker 256 carcinosarcoma growing in Sprague-Dawley rats and the Morris 5123 hepatoma growing in Buffalo rats both produce cachexia but have widely differing patterns of host metabolism and tumor growth. Both organisms respond to exogenous insulin with increased food intake and rate of weight gain of host. The insulin treatment response of food intake was 1.5 to 2 times and of body weight gain was 2 to 3 times that of tumor-free controls. Insulin does not accelerate tumor growth. On withdrawal of insulin, the reactive hypophagia seen in tumor-free rats does not occur in tumor bearers, and the host weight does not return to the expected untreated value as it does in tumor-free rats. Most of the weight gained during insulin treatment of tumor bearers above that gained by tumor-free rats is retained after withdrawal of insulin. A computer model based on the inference from these results, that the tumor-bearing host is blind to body weight error, indicates that this abnormality of feeding control could account for only about one-third of the observed depression of host weight and food intake.
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PMID:Feeding response of tumor-bearing rats to insulin and insulin withdrawal and the contribution of autonomous tumor drain to cachectic depletion. 704 59

The pathway of fat oxidation in two experimental hepatomas was studied in order to demonstrate that a specific deficit in the energy metabolism of a tumor might contribute to the cachexia of the host. Forty-eight male Buffalo rats were divided into four groups of 12 each. One group was implanted s.c. with Morris hepatoma 7777 and one group was implanted with Morris hepatoma 7800, whereas the other two groups served as controls. All groups were fed standard rat chow diet ad libitum until the tumors reached 2 cm in diameter. The animals were then fasted for 24 hr prior to sacrifice and excision of tumor and liver for assays. During the period of tumor growth, the animals bearing the 7777 hepatoma lost weight, but the weight of the 7800 hepatoma-bearing rats did not differ significantly from that of the control animals. The livers of both groups of animals showed evidence of fatty acid oxidation in vivo and in vitro, and, as expected, during fasting, pyruvate dehydrogenase was inactivated and the rate of fatty acid synthesis was low. A qualitatively similar picture was seen with the better-differentiated 7800 hepatoma. In contrast, the 7777 hepatoma exhibited low levels of fatty acyl coenzyme CoA, no appreciable activity of carnitine palmitoyl transferase and fortified homogenates of the tumor were unable to oxidize palmitate. In keeping with these observations, pyruvate dehydrogenase remained in the active form, and fatty acid synthesis continued unabated in the fasted state in these tumors. Ketone bodies could not be oxidized by fortified homogenates of the liver or by either tumor, probably due to the lack of 3-ketoacid thiotransferase, which was undetectable in these tissues. We hypothesize that flow-through pyruvate dehydrogenase during fasting in Morris hepatoma 7777, occurring as a result of the defect in fat oxidation, contributes to the weight loss of these animals.
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PMID:Regulation of energy metabolism in Morris hepatoma 7777 and 7800. 724 42

Tumor necrosis factor-alpha (TNF) has been suggested to be the mediator of insulin resistance in infection, tumor cachexia, and obesity. We have previously shown that TNF diminishes insulin-induced tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1). The current work examines potential mechanisms that mediate this event. TNF effect on IRS-1 in Fao hepatoma cells was not associated with a significant reduction in insulin receptor tyrosine kinase activity as measured in vitro but impaired the association of IRS-1 with phosphatidylinositol 3-kinase, localizing TNF impact to IRS-1. TNF did not increase protein-tyrosine phosphatase activity and protein-tyrosine phosphatase inhibition by vanadate did not change TNF effect on IRS-1 tyrosine phosphorylation, suggesting that protein-tyrosine phosphatases are not involved in this TNF effect. In contrast, TNF increased IRS-1 phosphorylation on serine residues, leading to a decrease in its electrophoretic mobility. TNF effect on IRS-1 tyrosine phosphorylation was not abolished by inhibiting protein kinase C using staurosporine, while inactivation of Ser/Thr phosphatases by calyculin A and okadaic acid mimicked it. Our data suggest that TNF induces serine phosphorylation of IRS-1 through inhibition of serine phosphatases or activation of serine kinases other than protein kinase C. This increased serine phosphorylation interferes with insulin-induced tyrosine phosphorylation of IRS-1 and impairs insulin action.
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PMID:Tumor necrosis factor alpha-induced phosphorylation of insulin receptor substrate-1 (IRS-1). Possible mechanism for suppression of insulin-stimulated tyrosine phosphorylation of IRS-1. 755 52

Rats transplanted with the ascites hepatoma Yoshida AH-130 developed a severely progressive cachexia, characterised by marked alterations in protein and lipid metabolism. In particular, high levels of serum triglycerides and free fatty acids were associated with altered levels and distribution of plasma cholesterol, with increased total and very low-density lipoprotein-low-density lipoprotein (VLDL-LDL) cholesterol and reduced high-density lipoprotein (HDL) cholesterol. The tumour cells showed high rates of cholesterol synthesis and elevated content of free and esterified cholesterol, whereas total cholesterol synthesis was reduced in the host liver. To determine whether these perturbations could be related to the elevation of tumour necrosis factor alpha (TNF-alpha) previously shown in the AH-130 bearers (Tessitore L, Costelli P, Baccino FM 1993, Br J Cancer, 67, 15-23), either anti-TNF polyclonal antibodies or non-immune IgGs were injected daily after tumour transplantation. The anti-TNF treatment neither affected tumour growth nor prevented the serum cholesterol changes, while attenuating the hypertriglyceridaemia and the elevated serum free fatty acid levels. These data indicate that TNF does not appear to be directly involved in the altered cholesterol metabolism in AH-130 hosts, thus supporting the view that cholesterol metabolism and lipid metabolism are regulated differently during tumour growth.
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PMID:Perturbations of triglycerides but not of cholesterol metabolism are prevented by anti-tumour necrosis factor treatment in rats bearing an ascites hepatoma (Yoshida AH-130). 757 59

It has been recently reported that a diet enriched in n-3 polyunsaturated fatty acids reduces the growth of different kinds of tumors as well as the host tissue hypercatabolic state frequently associated. The rat ascites hepatoma Yoshida AH-130 is a fast growing tumor that causes a rapid and progressive body weight loss in the host and tissue waste associated with a hypercatabolic condition. Plasma levels of classical hormones and humoral mediators (prostaglandin E2 and tumor necrosis factor-alpha) are early perturbed after tumor transplantation (Tessitore, L., Costelli, P. and Baccino, F.M. (1993) Humoral mediation for cachexia in tumour-bearing rats. Br. J. Cancer, 67, 16-23). Enhanced protein degradation rates and alteration of lipoprotein lipase activity mainly account for the wasting of protein and adipose mass, respectively. However, the daily intragastric administration of eicosapentaenoic acid (1.5 g/kg body wt) to AH-130 bearing rats was completely ineffective either in preventing tissue waste or in reducing tumor growth. The low degree of differentiation and the high growth rate of the AH0130 hepatoma probably account for this lack of effect.
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PMID:Lack of effect of eicosapentaenoic acid in preventing cancer cachexia and inhibiting tumor growth. 758 74

The mechanisms leading to the development of cancer cachexia are still poorly understood. Recently, cytokines such as interleukin 1 and tumour necrosis factor-alpha have been involved as mediators of the tissue wasting consequent to tumour growth. The rat ascites hepatoma Yoshida AH-130 is a highly anaplastic tumour that causes in the host an early and marked depletion of both the skeletal muscle and the adipose tissue, mainly accounted for by a hypercatabolic state. Profound hormonal alterations and the release of tumour necrosis factor-alpha and interleukin 1 by the tumour cells likely concur in forcing the metabolic balance towards the catabolic side [1]. In order to possibly achieve the correction of this wasting condition, the AH-130 bearing rats were administered a daily s.c. dose of interleukin 1 receptor antagonist (IL-1ra; 2 mg/kg). This factor, however, was completely ineffective in either inhibiting tumour proliferation or in preventing the consequent tissue depletion and protein hypercatabolism. These observations suggest that interleukin 1 is not important, at least in this model system, for either the development of cachexia or tumour growth.
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PMID:Interleukin-1 receptor antagonist (IL-1ra) is unable to reverse cachexia in rats bearing an ascites hepatoma (Yoshida AH-130). 765 41

Rats bearing the Yoshida AH-130 ascites hepatoma for 7 days showed an important decrease in muscle mass--over 30% in gastrocnemius and extensor digitorum longus (EDL)--in relation to non-tumour-bearing controls, which is associated with an increased proteolytic rate in in vitro incubation. In order to identify the precise biochemical process which was involved, we measured different proteolytic systems in incubated EDL muscles. The capacity for intralysosomal proteolysis, as measured by sensitivity to methylamine, was not increased in tumour-bearing rats, suggesting that the mechanism involved in the increased proteolytic rate was extralysosomal. Incubations using the Ca2+ ionophore A23187 revealed no change in the activity of calcium-dependent proteases as a consequence of tumour growth. Finally, muscle incubation in an ATP-depleted medium allowed us to conclude that energy-dependent proteases were involved in the activation of muscle proteolysis in tumour-bearing rats. In particular, the ubiquitin-dependent proteolytic system is involved, since there is an important increase in ubiquitin conjugates in the skeletal muscle of tumour-bearing rats. It may thus be suggested that extralysosomal ATP- and ubiquitin-dependent proteases underlie the biochemical mechanism of muscle wastage associated with cancer cachexia.
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PMID:Muscle wasting associated with cancer cachexia is linked to an important activation of the ATP-dependent ubiquitin-mediated proteolysis. 770 27


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