Mechanisms mediating cancer cachexia

SiBaoChongCao exhibited anti-fatigue activities and ameliorated cancer cachexia in mice

SiBaoChongCao (SBCC) is a functional food product containing fermentation of Acremonium terricola belonging to the Cordyceps genus. SBCC at 1 and 2 g kg⁻¹ for 20 days exhibited anti-fatigue activities such as increasing exhaustive swimming and running time of mice and increasing the strength of muscle. The increased muscle endurance in SBCC-treated mice might be related to enhancement of muscle cell growth and differentiation and improvement of muscle response to exercise training, as shown by an increase in muscle cross-sectional area and elevation of MHC, MyoD, MyoG and PGC-1α levels. And, SBCC at 1.5 g kg⁻¹ could ameliorate cancer-related cachexia such as ameliorating decrease in body temperature and inhibiting fat tissue atrophy. The anti-cachexia effects of SBCC might be related to inhibition of inflammatory cytokine IL-6 secretion and suppression of over-lipolysis and lipid over-utilization through inhibiting the activation of AMPK and p38 MAPK and down-regulating the level of UCP1.

SBCC exhibits anti-fatigue activity by improving muscle endurance and ameliorates cancer cachexia by alleviating loss of fat and body temperature.

Malnutrition and cachexia in patients with head and neck cancer treated with (chemo)radiotherapy

AIM

To highlight the problems associated with nutrition that occur in patients with squamous cell carcinoma of the head and neck (SCCHN).

BACKGROUND

SCCHN is associated with weight loss before, during and after radiotherapy or concurrent chemoradiotherapy. Because of serious consequences of malnutrition and cachexia on treatment outcome, mortality, morbidity, and quality of life, it is important to identify SCCHN patients with increased risk for the development of malnutrition and cachexia.

MATERIALS AND METHODS

Critical review of the literature.

RESULTS

This review describes pathogenesis, diagnosis and treatment of malnutrition and cancer cachexia. Treatment of malnutrition and cancer cachexia includes nutritional interventions and pharmacological therapy. Advantages and disadvantages of different nutritional interventions and their effect on the nutritional status, quality of life and specific oncological treatment are presented.

CONCLUSIONS

Nutritional management is an essential part of care of these patients, including early screening, assessment of nutritional status and appropriate intervention.

Ghrelin in neuroendocrine tumors

Ghrelin is a 28 amino acid peptide, primarily produced by the oxyntic mucosa X/A like neuroendocrine cells in the stomach. It is also found in the small intestine, hypothalamus, pituitary gland, pancreas, heart, adipose tissue, and immune system. In gastrointestinal neuroendocrine tumors (NETs) ghrelin release has been well documented. Ghrelin is a brain-gut circuit peptide with an important role in the physiological regulation of appetite, response to hunger and starvation, metabolic and endocrine functions as energy expenditure, gastric motility and acid secretion, insulin secretion and glucose homeostasis, as well as in the potential connection to the central nervous system. Recently, there has been a significant interest in the biological effects of ghrelin in NETs. In this article, we present a comprehensive review of ghrelin's expression and a brief summary of ghrelin's physiological role in NETs patients with carcinoids, type A chronic atrophic gastritis (CAG), with or without MEN-1, and with and without liver metastases. We hope, with the research reviewed here, to offer compelling evidence of the potential significance of ghrelin in NETs, as well as to provide a useful guide to the future work in this area.

Cachexia, malnutrition, the refeeding syndrome, and lessons from Goldilocks

Cachexia has plagued clinicians for centuries. Although all cachexia is related to malnutrition, cachexia associated with malignant diseases differs from starvation cachexia in that it is more recalcitrant to nutritional therapy. All cachexia responds to judicious nutritional support; however, cancer cachexia worsens autonomously as the disease advances and cannot be arrested or reversed by any known form of nutrition, hormonal, or pharmacologic therapy. Cachexia must be treated cautiously to avoid overfeeding syndrome, which may result in serious or dangerous complications or death.

Role of carnitine in cancer chemotherapy-induced multiple organ toxicity

In the last few years, cancer chemotherapy has been successfully employed in the treatment of different types of human tumours. Unfortunately, the optimal clinical usefulness of this important treatment modality is usually limited secondary to the development of life-threatening multiple organ toxicity. Cancer chemotherapy may cause these toxic effects by mechanisms not involved in their anticancer activity that can severely affect the life of patients and represent a direct cause of death. Several experimental and clinical studies have demonstrated that some important anticancer drugs interfere with the absorption, synthesis, and excretion of carnitine in non-tumour tissues, resulting in a secondary carnitine deficiency which is reversed by carnitine treatment without affecting anticancer therapeutic efficacy. Prototypes of anticancer drugs that alter carnitine system are doxorubicin, cisplatin, carboplatin, oxaliplatin, cyclophosphamide and ifosfamide. Furthermore, cachectic cancer patients are especially at risk for carnitine deficiency due to decreased oral intake and/or increased renal losses. Altered serum and urine carnitine levels have been reported in cancer patients with various forms of malignant diseases. Recent studies in our laboratory have demonstrated that carnitine deficiency constitute a risk factor and should be viewed as a mechanism during development of oxazaphosphorines-induced cardiotoxicity in rats. Similarly, inhibition of gene expression of heart fatty acid-binding protein and organic cation/carnitine transporter in doxorubicin cardiomyopathic rat model has been reported. In view of these facts and in view of irreplaceability of these important anticancer drugs, this review aimed to highlight the role of carnitine depletion and supplementation during development of chemotherapy-induced multiple organ toxicity.

Parathyroid hormone-related protein has an anorexigenic activity via activation of hypothalamic urocortins 2 and 3

Cancer cachexia is reported to be a major cause of cancer-related death. Since the pathogenesis is not entirely understood, only few effective therapies have been established. Since myriad tumors produce parathyroid hormone-related protein (PTHrP), plasma concentrations of PTHrP are increased in cancer cachexia. We measured the food intake, gastric emptying, conditioned taste aversion (CTA), and gene expression of hypothalamic neuropeptides in mice after administering PTHrP intraperitoneally. We administered PTHrP intravenously in rats and examined the gastroduodenal motility and vagal nerve activities. We also examined whether chronic administration of PTHrP influenced the food intake and body weight. Peripherally administered PTHrP induced negative energy balance by decreasing the food intake and gastric emptying; however, it did not induce CTA. The mechanism involved the activation of hypothalamic urocortins 2 and 3 through vagal afferent pathways and the suppression of gastroduodenal motor activity. The continuous infusion of PTHrP reduced the food intake and body weight gain with a concomitant decrease in the fat and skeletal muscle. Our findings suggest that PTHrP influences the food intake and body weight; therefore, PTHrP can be considered as a therapeutic target for cancer cachexia.

A systems biology approach to invasive behavior: comparing cancer metastasis and suburban sprawl development

Background

Despite constant progress, cancer remains the second leading cause of death in the United States. The ability of tumors to metastasize is central to this dilemma, as many studies demonstrate successful treatment correlating to diagnosis prior to cancer spread. Hence a better understanding of cancer invasiveness and metastasis could provide critical insight.

Presentation of the hypothesis

We hypothesize that a systems biology-based comparison of cancer invasiveness and suburban sprawl will reveal similarities that are instructive.

Testing the hypothesis

We compare the structure and behavior of invasive cancer to suburban sprawl development. While these two systems differ vastly in dimension, they appear to adhere to scale-invariant laws consistent with invasive behavior in general. We demonstrate that cancer and sprawl have striking similarities in their natural history, initiating factors, patterns of invasion, vessel distribution and even methods of causing death.

Implications of the hypothesis

We propose that metastatic cancer and suburban sprawl provide striking analogs in invasive behavior, to the extent that conclusions from one system could be predictive of behavior in the other. We suggest ways in which this model could be used to advance our understanding of cancer biology and treatment.

Beneficial immune modulatory effects of a specific nutritional combination in a murine model for cancer cachexia

The majority of patients with advanced cancer are recognised by impaired immune competence influenced by several factors, including the type and stage of the tumour and the presence of cachexia. Recently, a specific nutritional combination containing fish oil, specific oligosaccharide mixture, high protein content and leucine has been developed aimed to support the immune system of cancer patients in order to reduce the frequency and severity of (infectious) complications. In a recently modified animal model cachexia is induced by inoculation of C26 tumour cells in mice. In a pre-cachectic state, no effect was observed on contact hypersensitivity, a validated in vivo method to measure Th1-mediated immune function, after adding the individual nutritional ingredients to the diet of tumour-bearing mice. However, the complete mixture resulted in significantly improved Th1 immunity. Moreover, in a cachectic state, the complete mixture reduced plasma levels of pro-inflammatory cytokines and beneficially affected ex vivo immune function. Accordingly, the combination of the nutritional ingredients is required to obtain a synergistic effect, leading to a reduced inflammatory state and improved immune competence. From this, it can be concluded that the specific nutritional combination has potential as immune-supporting nutritional intervention to reduce the risk of (infectious) complications in cancer patients.

An inflammation-based prognostic score and its role in the nutrition-based management of patients with cancer

Progressive involuntary weight loss, in particular the loss of lean tissue, is common in patients with advanced cancer and has long been recognised to result in a deterioration in performance status and quality of life, increased morbidity and mortality. The aetiology of such weight loss or cachexia is complex and involves both tumour and host responses. Thus, identification of patients who are or are likely to become cachectic has been problematic. In addition to a reduction in appetite and increased satiety leading to poor dietary intake, there is now increasing clinical evidence that the activation of a chronic ongoing systemic inflammatory response is one of the earliest and most important contributory factors to cachexia. Such findings help to explain the failure of simple nutritional programmes to reverse weight loss adequately in patients with cancer. In the present paper the development of an inflammation-based score is described, which is derived from the acute-phase proteins C-reactive protein and albumin and is termed the Glasgow prognostic score (GPS). Its value as a predictor of survival, independent of tumour stage, performance status and treatment (active or palliative), has been shown in a variety of advanced common solid tumours. The nature of the relationship between the GPS, appetite, body composition, performance status and quality of life of the patient with advanced cancer will be described. Recently, it has become evident that the systemic inflammatory response is also present in a smaller proportion of patients with primary operable cancer and is also predictive of disease progression and poor survival. The role of GPS in clinical decision making will be discussed.

Effect of oral nutritional supplementation on weight loss and percutaneous endoscopic gastrostomy tube rates in patients treated with radiotherapy for oropharyngeal carcinoma

GOALS

Malnutrition in the head and neck cancer population is a widely recognized factor contributing to negative outcomes. The goal of this study was to determine if providing complimentary oral nutritional supplementation for patients undergoing definitive radiation therapy for oropharyngeal carcinoma reduced weight loss and the need for percutaneous endoscopic gastrostomy (PEG) tube placement.

MATERIALS AND METHODS

The data from 79 patients undergoing radiotherapy for oropharyngeal cancer were extracted and analyzed retrospectively from an institutional Human Investigation Committee approved database for the study of advanced radiation therapy techniques for head and neck cancer. Forty patients were treated before the initiation of a nutritional supplementation program, and 39 patients received supplementation. Patients were stratified by type of treatment (radiation alone or chemoradiation) and whether or not they had a PEG tube.

RESULTS

All patient groups receiving supplementation manifested a significant decrease in weight loss compared to those who did not receive it. Nutritional supplementation was associated with a 40% relative reduction in weight loss in patients treated with radiotherapy alone (6.1 vs 10.1%, p = 0.008) and a 37% reduction in weight loss in patients treated with chemoradiotherapy (6.7 vs 10.7%, p = 0.007). When patients were stratified by the presence or absence of a PEG tube, both groups experienced a 39% relative reduction in weight loss (with PEG, 5.7 vs 9.3%, p = 0.028; without PEG, 6.9 vs 11.2%, p = 0.002). Supplementation was associated with a decreased need for PEG tube placement (31% decreased to 6%) in patients treated with radiotherapy alone.

CONCLUSIONS

Providing complimentary oral nutritional supplementation significantly decreases weight loss and the need for PEG tube placement in patients undergoing radiation therapy for oropharyngeal cancer.

Serum carnitine levels in patients with tumoral cachexia

BACKGROUND

Cachexia is a serious complication of many cancers that is common in cancer and AIDS patients. However, the key factors and mechanisms involved in the development of cachexia are not yet understood. There is little data currently available regarding carnitine metabolism in patients with neoplasm and cachexia.

METHODS

Forty-six neoplastic patients with different localizations of their primary disease gave signed, informed consent before enrolling in the present study. They underwent routine laboratory investigation, including examination of the levels of the various forms of carnitine present in serum (i.e., long-chain acylcarnitine, short-chain acylcarnitine, soluble acid acylcarnitine, free carnitine, and total carnitine). These values were compared with those found in 30 cancer patients in good nutritional status as well as with those of 30 healthy control subjects.

RESULTS

In the comparison of serum plasma carnitine of cachectic patients versus controls, the difference in free carnitine was - 8.20 micromol/L (p=0.000); the difference in short-chain acylcarnitine - 2.60 micromol/L (p=0.029); the difference in soluble acid carnitine - 10.80 micromol/L (p=0.000); the difference in long-chain acylcarnitine - 0.40 micromol/L (p=0.036); and the difference in total carnitine -11.20 micromol/L (p=0.000). In the comparison of serum plasma carnitine of cachectic versus neoplastic patients in good nutritional status, the difference in free carnitine was -5.80 micromol/L (p=0.006); the difference in soluble acid carnitine - 7.20 micromol/L (p=0.000); and the difference in total carnitine - 7.50 micromol/L (p=0.000).

CONCLUSION

Our study showed that, in the multifactorial pathogenesis of cachexia, the low serum levels of carnitine in terminal neoplastic patients, which are due to a decreased dietary intake as well as to an impaired endogenous synthesis of this substance, could play an important role. These low serum carnitine levels may also contribute to the development of cachexia in cancer patients.

Effects of the tumour necrosis factor-alpha inhibitors pentoxifylline and thalidomide in short-term experimental oral mucositis in hamsters

Oral mucositis is a frequent side-effect of cancer therapy. A definitive method of prophylaxis or treatment is not yet available. As pentoxifylline (PTX) and thalidomide (TLD) have been shown to inhibit cytokine synthesis, we studied the effects of these cytokine inhibitors in an experimental oral mucositis model. Oral mucositis was induced in Golden hamsters by the administration of 5-fluorouracil (5-FU) followed by mechanical trauma of the cheek pouch. On days 4, 5, 10, 12, 14 and 16, lesions induced by 5-FU were examined macroscopically and microscopically, and the presence and intensity of hyperemia, erythema, edema, inflammatory cell infiltration, hemorrhagic areas, ulcers and abscesses were recorded. Saline (control), PTX (5, 15, 45 mg kg(-1)) or TLD (10, 30, 90 mg kg(-1)) were administered daily and animals were killed on day 10 for macroscopic and histological analysis and assay of myeloperoxidase (MPO) activity. Animals were weighed daily, and total and differential leukocyte counts were performed on peripheral blood. PTX and TLD were found to reduce the macroscopic and histological parameters of oral mucositis and MPO activity. PTX and TLD also reversed peripheral neutrophilia, but only PTX prevented weight loss. The results indicate a protective effect of PTX and TLD, suggesting an important role for tumour necrosis factor-alpha (TNF-alpha) in the pathophysiology of 5-FU induced-oral mucositis in hamsters.

Pharmacokinetic variability of anticancer agents

The translation of advances in cancer biology to drug discovery can be complicated by pharmacokinetic variation between individuals and within individuals, and this can result in unpredictable toxicity and variable antineoplastic effects. Previously unrecognized variables (such as genetic polymorphisms) are now known to have a significant impact on drug disposition. How can the pharmacokinetic variability of anticancer agents be reduced? This will require the understanding of correlations between pharmacokinetics and treatment outcomes, the identification of relevant patient parameters, mathematical modelling of individual and population pharmacokinetics, and the development of algorithms that will tailor doses to the individual patient.

Effect of short-term cigarette smoke exposure on body weight, appetite and brain neuropeptide Y in mice

Although nicotinic receptors have been demonstrated in hypothalamic appetite-regulating areas and nicotine administration alters food intake and body weight in both animals and humans, the mechanisms underlying the effects of smoking on appetite circuits remain unclear. Conflicting effects of nicotine on the major orexigenic peptide, neuropeptide Y (NPY), have been observed in the brain, but the effects of smoking are unknown. Thus, we aimed to investigate how cigarette smoking affects body weight, food intake, plasma leptin concentration, hypothalamic NPY peptide, adipose mass and mRNA expression of uncoupling proteins (UCP), and tumor necrosis factor (TNF) alpha. Balb/C mice (8 weeks) were exposed to cigarette smoke (three cigarettes, three times a day for 4 consecutive days) or sham exposed. Body weight and food intake were recorded. Plasma leptin and brain NPY were measured by radioimmunoassay. UCPs and TNF alpha mRNA were measured by real-time PCR. Food intake dropped significantly from the first day of smoking, and weight loss became evident within 2 days. Brown fat and retroperitoneal white fat masses were significantly reduced, and plasma leptin concentration was decreased by 34%, in line with the decreased fat mass. NPY concentrations in hypothalamic subregions were similar between two groups. UCP1 mRNA was decreased in white fat and UCP3 mRNA increased in brown fat in smoking group. Short-term cigarette smoke exposure led to reduced body weight, food intake, and fat mass. The reduction in plasma leptin concentration may have been too modest to increase NPY production; alternatively, change in NPY or its function might have been offset by nicotine or other elements in cigarette smoke.

Relationship between plasma leptin, insulin and tumor necrosis factor alpha in obese children

OBJECTIVES

1. To evaluate the relationship between plasma leptin and TNFalpha concentrations in obese children and to assess the differences between hyperinsulinemic and normoinsulinemic groups. 2. To evaluate the relationship between plasma leptin and insulin levels in obese children. 3. To investigate the TNFalpha G308A mutation in obese children.

METHODS

Body mass index (BMI), fasting plasma glucose and insulin levels, oral glucose tolerance test results, homeostasis model assessment of insulin resistance (HOMA-IR) results, and plasma leptin and TNFalpha concentrations were evaluated in obese children (n = 45) and age- and gender-matched, lean healthy controls (n = 40).

RESULTS

In obese children the fasting insulin, HOMA-IR results, plasma leptin and TNFalpha concentrations were significantly higher than in controls (p <0.05). Furthermore, obese females showed higher plasma leptin and insulin resistance compared to obese males. While plasma leptin, TNFalpha levels and HOMA-IR results were similar in the prepubertal and pubertal groups, insulin levels were significantly higher in the pubertal group. Plasma leptin and TNFalpha concentrations were similar in hyperinsulinemic and normoinsulinemic obese children. In control children, plasma leptin concentrations showed a positive correlation with BMI, age, fasting insulin and HOMA-IR results. In obese children, plasma leptin levels did not correlate with BMI, fasting insulin or TNFalpha.

CONCLUSION

Plasma leptin concentrations did not show any correlation with TNFalpha levels in obese children. Furthermore, plasma leptin and TNFalpha concentrations were similar in hyperinsulinemic and normoinsulinemic obese children.

The embedded tumour: host physiology is important for the evaluation of tumour growth

The growth potential of a tumour can significantly depend on host features such as age, cell proliferation rates and caloric intake. Although this is widely known, existing mathematical models for tumour growth do not account for it. We therefore developed a new model for tumour growth, starting from a mathematical framework that describes the host's physiology. The resulting tumour-in-host model allowed us to study the implications of various specific interactions between the energetics of tumour and host. The model accounts for the influence of both age and feeding regimen of the host organism on the behaviour of a tumour. Concerning the effects of a tumour on its host, it explains why tumour-mediated body-weight loss is often more dramatic than expected from the energy demands of the tumour. We also show how the model can be applied to study enhanced body-weight loss in presence of cachectic factors. Our tumour-in-host model thus appears a proper tool to unite a wide range of phenomena in tumour–host interactions.

Smoking, fat mass and activation of the tumor necrosis factor-alpha pathway

OBJECTIVE

Obesity may be associated with increased markers of inflammation that could be triggered by metabolic, physical, infectious or environmental processes. As smoking significantly increases cytokine production, we aimed to study how smoking influences the relationship between fat mass and soluble tumor necrosis factor-alpha (TNF-alpha) receptors 1 and 2 (sTNFR1 and sTNFR2).

DESIGN

Cross-sectional, clinical observational study.

SUBJECTS

A total of 133 healthy men (age: 27-53 y, body mass index (BMI): 24-30.2 kg/m(2)), 80 of whom were never-smokers and 53 smokers, matched for age, BMI and waist-to-hip ratio.

MEASUREMENTS

Circulating soluble fractions of the TNF-alpha receptors sTNFR1 and sTNFR2 were measured to study their relationship with fat mass (bioelectric impedance).

RESULTS

Smokers had significantly lower fat mass, lower fasting glucose, insulin and leptin concentrations than nonsmokers. Despite lower fat mass and insulin, smokers showed significantly increased circulating sTNFR2 levels (3.7+/-0.8 vs 3.4+/-0.7 ng/ml, P=0.03). The slopes of the relationships between sTNFR1 and fat mass, and between sTNFR2 and fat mass, were significantly steeper in smokers than in nonsmokers. In a stepwise multiple linear regression analysis, both fat mass (P<0.00001) and smoking (P=0.025) independently contributed to 13% of sTNFR1 variance and to 4% of sTNFR2 variance (P=0.03).

CONCLUSION

Both fat mass and smoking are related to increased activity of the TNF-alpha axis.

Degradation of transgene-coded and endogenous proteins in the muscles of Caenorhabditis elegans

To develop reporter systems to study the regulation of protein degradation in innervated muscle, we have used strains of the nematode Caenorhabditis elegans containing transgenes that fuse lacZ or green fluorescent protein (GFP) coding regions to muscle-specific promoter/enhancer regions, such that the fusion proteins are expressed exclusively in body-wall and vulval muscle cells. The starvation-induced degradation of the beta-galactosidase reporter protein is quantitatively similar to that of two endogenous muscle proteins, arginine kinase and adenylate kinase. A soluble GFP in the muscle cytosol is degraded during starvation, but when GFP is fused to a full-length myosin heavy chain and incorporated into myofibrils, it is resistant to starvation-induced degradation. This suggests that under some conditions soluble muscle proteins may be extensively catabolized in preference to the proteins of the contractile fibers.

Determination of D-amino acid oxidase activity in tumour cells

BACKGROUND

We evaluated the assay for determining D-amino acid oxidase (DAAO) activity in tumour cells, rat liver and rat kidney for studying the effects of D-amino acid-containing solution on cancer patients.

METHODS AND RESULTS

In this method the amount of ammonia produced by the DAAO activity after removal of endogenous ammonia using a Sephadex G25 column was determined. The highest activity was observed in rat kidney, which was almost eight times that found in rat liver. As compared with host tissues, the DAAO activity in tumour cells was considerably less.

CONCLUSIONS

This DAAO assay may be useful for analysis of various tissue samples as well as tumour cells.

Activation of Ras and the mitogen-activated protein kinase pathway promotes protein degradation in muscle cells of Caenorhabditis elegans

To discover and study intracellular signals that regulate proteolysis in muscle, we have employed transgenic strains of Caenorhabditis elegans that produce a soluble LacZ reporter protein limited to body-wall and vulval muscles. This reporter protein is stable in well-fed wild-type animals, but its degradation is triggered upon a shift to 25 degrees C in a strain carrying a temperature-sensitive activating mutation in the Ras oncogene homologue let-60. These mutants are not physiologically starved, inasmuch as growth rates are normal at 25 degrees C. Ras-induced degradation is not prevented by the presence of cycloheximide added at or before the temperature shift and thus uses preexisting proteolytic systems and signaling components. Furthermore, degradation is triggered when adult animals are shifted to conditions of 25 degrees C, confirming that Ras acutely promotes protein degradation in muscles whose developmental history is normal. Reduction-of-function mutations in the downstream protein kinase Raf (lin-45), MEK (mek-2), or mitogen-activated protein kinase (MAPK) (mpk-1) prevent Ras-induced protein degradation, whereas activated MPK-1 is sufficient to trigger degradation, indicating that this kinase cascade is the principal route by which Ras signaling triggers protein degradation in muscle. This pathway is activated in hypodermal cells by the LET-23 epidermal growth factor receptor homologue, but an activating mutation in let-23 does not promote proteolysis in muscle. Starvation-induced LacZ reporter degradation is unaffected by reduction-of-function mutations in Ras, Raf, MEK, or MAPK, implying that Ras activation and starvation trigger proteolysis by mechanisms that are at least partially independent. This is the first evidence that Ras-Raf-MEK-MAPK signaling activates protein degradation in differentiated muscle.

Importance of weight loss definition in the prognostic evaluation of non-small-cell lung cancer

In both clinical practice and scientific reporting, various definitions of weight loss (WL) are currently in use. A comparison of their efficiency would be appropriate. In this report, we describe the first clinical evaluation of different WL definitions. New consecutive non-small-cell lung cancer (NSCLC) patients (388) were prospectively studied at the Pulmonary Unit of 'S. Croce and Carle' Hospitals from 1995 to 1999. Multiple anthropometric, clinical and pathological data, along with eight WL-related variables, were analysed. Patients' length of survival was estimated using the Kaplan-Meier function and the Cox's multivariate regression. In univariate analysis, all WL variables were prognostically significant. Among them, total WL (i.e. the percent difference between the weight at diagnosis and the last weight recorded while in good health, dichotomised by the threshold level of 11%) was the most significant factor (Log-rank: 29.65, P=0.0000). The best Cox's model for survival prediction, constructed using all the available clinical information, included, in order of importance, the following three factors: stage of disease classification, performance status and total WL. Contrary to what one might expect, WL speedy was less predictive than WL quantity. Evidence from this study suggests that, while the loss of body weight is confirmed a significant prognostic factor in NSCLC, the value of this factor is partially dependent on its definition.

Anemia-inducing substance is related to elimination of lipolytic hyperactivity by cyclic plasma perfusion in human cancer cachexia

We previously reported that cyclic plasma perfusion suppressed lipolytic activity in malignant tumor-bearing animals and reversed their body weight loss. In this study we investigated the relation between this phenomenon and interleukin (IL)-1 alpha, IL-1 beta, IL-6, interferon-gamma, leukemia inhibitory factor, tumor necrosis factor-alpha, and anemia-inducing substance (AIS) in vitro by examining changes in their levels in the plasma of advanced ovarian cancer patients. When the patients' plasma was incubated with noncoated charcoal for one hour, its lipolytic activity decreased by 39.0 +/- 2.4%, which was similar to the results obtained with the plasma of healthy subjects. IL-1 alpha, IL-1 beta, interferon-gamma, leukemia inhibitory factor, and tumor necrosis factor-alpha did not adsorb the charcoal. IL-6 was 3.7% adsorbed, but this did not cause a significant difference (p = 0.131). Nor was the recombinant form of these cytokines adsorbed to the charcoal. AIS, however, was 98.1% adsorbed. These results indicate that AIS is strongly associated with the reduction in lipolytic activity by cyclic plasma perfusion through noncoated charcoal resin.

Expression of apoptosis regulatory proteins in the skeletal muscle of tumor-bearing rabbits

We reported finding that apoptosis occurred in skeletal muscle in the early stage after implantation. In the present study, we investigated expression of the apoptosis-related proteins Bax and Bcl-2 to determine the mechanism of the apoptosis. In the early stage of tumor bearing, 20 days after implantation, lean body mass (LBM) was reduced by 5.06 +/- 1.10% in the tumor-bearing group, compared with an increase of 4.96 +/- 1.26% in the control group. The apoptotic index (AI) of the skeletal muscle in the tumor-bearing group increased to 40.5 +/- 3.20% but was 0% in the control group, and Bax expression was strongly positive in 5 of the 10 rabbits in the tumor-bearing group, and significantly stronger than in the control group (P = 0.0002). In the late stage of tumor bearing, 40 days after implantation, the AI had declined to 0.93 +/- 0.96% in the tumor-bearing group, but was still 0% in the control group. Bax expression was rarely detected in either the tumor-bearing group or the control group, and there was no significant difference between the two groups (P = 0.706). No significant changes in Bcl-2 were observed in either group. The above results showed that apoptosis via Bax played a role in muscle wasting associated with progression of the malignant tumor. However, the apoptosis and expression of Bax were seen only in the early stage, within 20 days after implantation, not in the late stage. This suggested that the muscle wasting in the early stage might be caused by a different mechanism from that in the late stage.

Nasogastric tube feeding in children with cancer: the effect of two different formulas on weight, body composition, and serum protein concentrations

BACKGROUND

Treatment of cancer cachexia partly involves the administration of adequate amounts of energy. The aim of this study was to assess the tolerance and efficacy of two equal volumes of tube feeding, one with a standard (1 kcal/mL) and one with a high energy density (1.5 kcal/mL), during the intensive phase of treatment.

METHODS

Nutritional status was assessed weekly, in 27 children with a solid tumor, by measuring weight, height, midupper arm circumference, biceps and triceps skinfold, and serum proteins. Tolerance was assessed by recording the occurrence of vomiting and by expressing the administered volume as a percentage of the required volume.

RESULTS

Both formulas were equally well tolerated, leading to a significantly higher energy intake in the energy-enriched formula group. In both formula groups, all anthropometric variables increased significantly (range of mean increase, 5.2% to 25.5%; p < .05) during the first 4 weeks of intervention. Between 4 and 10 weeks, variables continued to increase significantly in the energy-enriched group, resulting in adequate repletion, in contrast to the standard formula group. The concentration of serum proteins, low at initiation of tube feeding, returned to the normal range within 2 to 4 weeks with no significant differences between the two groups.

CONCLUSIONS

The energy-enriched formula was more effective in improving the nutritional status of children with cancer during the intensive phase of treatment than the standard formula. Intensive, protocolized administration of an energy-enriched formula should therefore be initiated as soon as one of the criteria for initiation of tube feeding is met.

The mouse Psma1 gene coding for the alpha-type C2 proteasome subunit: structural and functional analysis, mapping, and colocalization with Pde3b on mouse chromosome 7

We have isolated and functionally characterized the mouse gene for the C2 subunit of the 20S proteasome. The gene contains 10 exons distributed over a region of 12 kb on the distal end of mouse chromosome 7. Its exon-intron structure differs from those of the other few known proteasome genes. Transfection assays revealed that 1.5 kb of 5' flanking sequence is active as promoter in cultured myoblasts. Deletion reporter constructs narrowed this presumptive promoter region to within 450 bp upstream of the translation initiation site. Several consensus motifs for transcription factor binding sites were identified in this upstream region of the gene. Psma1 was mapped to mouse chromosome 7 using the interspecific backcross DNA panels from The Jackson Laboratory. Additional mapping studies showed that the mouse genes Psma1 and Pde3b are closely linked, residing between cM 53 and 53.3 in a region syntenic to human chromosome 11p15. Our results extend the structural and functional analysis of genes encoding the 20S proteasome subunits and provide the basis for the study of their regulation.

Genetic defects in acetylcholine signalling promote protein degradation in muscle cells of Caenorhabditis elegans

A myosin-lacZ fusion, expressed in 103 muscle cells of Caenorhabditis elegans, reports on how proteolysis in muscle is controlled by neural and intramuscular signals. Upon acute starvation, the fusion protein is degraded in the posterior 63 cells of the body-wall muscle, but remains stable in 32 anterior body-wall muscles and 8 vulval muscle cells. This distinction correlates with differences in the innervation of these cells. Reporter protein in the head and vulval muscles becomes labile upon genetic ‘denervation’ in mutants that have blocks in pre-synaptic synthesis or release of acetylcholine (ACh) or post-synaptic reception at nicotinic ACh receptors (nAChR), whereas protein in all 103 muscles is stabilized by the nicotinic agonist levamisole in the absence of ACh production. Levamisole does not stabilize muscle protein in nAChR mutants that are behaviorally resistant to levamisole. Neural inputs thus exert negative control over the proteolytic process in muscle by stimulating muscle nicotinic ACh receptors.

Nutritional support of the cancer patient: issues and dilemmas

Malnutrition in cancer patients results from multifactorial events and is associated with an alteration of quality of life and a reduced survival. A simple nutritional assessment program and early counselling by a dietitian are essential to guide nutritional support and to alert the physician to the need for enteral (EN) or parenteral nutrition (PN). A daily intake of 20-35 kcal/kg, with a balanced contribution of glucose and lipids, and of 0.2-0.35 g nitrogen/kg is recommended both for EN and PN, with an adequate provision of electrolytes, trace elements and vitamins. EN, always preferable for patients with an intact digestive tract, and PN are both safe and effective methods of administering nutrients. The general results in clinical practice suggest no tumor growth during nutritional support. The indiscriminate use of conventional EN and PN is not indicated in well-nourished cancer patients or in patients with mild malnutrition. EN or PN is not clinically efficacious for patients treated with chemotherapy or radiotherapy, unless there are prolonged periods of GI toxicity, as in the case of bone marrow transplant patients. Severely malnourished cancer patients undergoing major visceral surgery may benefit from perioperative nutritional support, preferably via enteral access. Nutritional support in palliative care should be based on the potential risks and benefits of EN and PN, and on the patient's and family's wishes. Research is currently directed toward the impact of nutritional pharmacology on the clinical outcome of cancer patients. Glutamine-supplemented PN is probably beneficial in bone marrow transplant patients. Immune diets are likely to reduce the rate of infectious complications and the length of hospital stay after GI surgery. Further studies are needed to determine the efficacy of such novel approaches in specific populations of cancer patients, and should also address the question of the overall cost-benefit ratio of nutritional pharmacology, and the effect of nutritional support on length and quality of life.

Tumor necrosis factor-alpha-induced apoptosis is associated with suppression of insulin-like growth factor binding protein-5 secretion in differentiating murine skeletal myoblasts

Wasting of muscle and fat during cachexia exceeds that explained by reduced food intake alone. This wasting may result from an imbalanced cytokine environment, which could lead to increased protein catabolism. Supporting this, tumor necrosis factor-alpha (TNF-alpha) is raised in several animal models of cachectic muscle wasting. Therefore, we assessed the effects of TNF-alpha and its second messenger, ceramide, on the proliferation, differentiation, and survival of murine C2 skeletal myoblasts. Because insulin-like growth factor binding protein-5 (IGFBP-5) and insulin-like growth factor-II (IGF-II) are potent regulators of myoblast proliferation and differentiation, we monitored the ability of exogenous TNF-alpha to manipulate this system. Fibroblast growth factor (FGF) ceramide, or TNF-alpha suppressed differentiation of C2 cells compared with controls. All treatments suppressed IGF-II production but only TNF-alpha blocked IGFBP-5 secretion. TNF-alpha increased apoptotic cell death, which otherwise remained basal (low serum differentiation medium (LSM), FGF) or low (ceramide). Suppression of both IGFBP-5 and IGF-II secretion may explain why of all triggers tested, only TNF-alpha not only blocked differentiation, but also promoted cell death. This suggests a fundamental role of IGFBP-5 for maintaining muscle survival. Supporting this hypothesis, no increase in apoptosis was seen in IGFBP-5 cDNA tranfected C2 cells after TNF-alpha treatment. In summary, the IGF system is essential for maintaining skeletal muscle cell survival and differentiation, and its suppression by TNF-alpha is fundamental regarding muscle wasting, and may be associated in vivo with cancer cachexia.

A discordance of the cytochrome P450 2C19 genotype and phenotype in patients with advanced cancer

AIMS

To examine the relationship between cytochrome P450 2C19 (CYP2C19) genotype and expressed metabolic activity in 16 patients with advanced metastatic cancer.

METHODS

Individual CYP2C19 genotypes were determined by PCR-based amplification, followed by restriction fragment length analysis, and compared with observed CYP2C19 metabolic activity, as determined using the log hydroxylation index of omeprazole.

RESULTS

All 16 patients had an extensive metabolizer genotype. However, based on the antimode in a distribution of log omeprazole hydroxylation indices from healthy volunteers, four of the patients had a poor metabolizer phenotype and there was a general shift of the remaining 12 patients towards a slower metabolic phenotype. This suggests a reduction in metabolic activity for all patients relative to healthy volunteers. A careful analysis of patient medical records failed to reveal any drug interactions or other source for the observed discordance between genotype and phenotype.

CONCLUSIONS

There are no previous reports of a 'discordance' between genotype and expressed enzyme activity in cancer patients. Such a decrease in enzyme activity could have an impact on the efficacy and toxicity of chemotherapeutic agents and other drugs, used in standard oncology practice.

Beta-adrenoceptor activity and resting energy metabolism in weight losing cancer patients

This study was aimed at comparing the blocking of beta-adrenoceptor activity to changes in the resting energy metabolism of 10 cancer patients with progressive weight loss due to solid malignant tumours. Resting energy expenditure (REE) as well as whole body carbohydrate and fat oxidation were investigated and related to plasma substrate levels (glucose, glycerol, free fatty acids (FFA)) before and after 5 days of oral administration of specific beta1 receptor blocker (atenolol, 50 mg/day) and non-specific beta1,beta2-adrenoceptor (propranolol, 80 mg/day) blockade. The administration order of the drugs was random, and a 3-day washout period was used in all individuals between the provision of the first and the second drug in order to minimise the risk of carry-over effects. Resting measurements in the morning after an overnight fast were performed by indirect calorimetry. Atenolol treatment reduced REE by 77+/-14 kcal/day and propranolol by 48+/-13 kcal/day, respectively (P<0.05 versus pretreatment values). Whole body oxygen uptake and carbon dioxide production were decreased similarly by both atenolol and propranolol treatment (P<0.05). Carbohydrate oxidation was increased by atenolol and decreased by propranolol, whilst fat oxidation was decreased by atenolol and unchanged by propranolol. The decrease in REE, accounting for the decline in heart rate, was significantly more pronounced following treatment with propranolol compared with atenolol (P<0.05). Atenolol and propranolol had no effect on blood glucose, plasma glycerol and FFA. We conclude that wastage in cancer patients is in part explained by increased beta(1) and beta(2)-adrenoceptor activity, in part secondary to elevated cardiovascular activity as a result of anaemia, loss of cardiac contractile capacity and altered host metabolism.

Differential effects of insulin-like growth factor I (IGF-I) and IGF-binding protein-1 on protein metabolism in human skeletal muscle cells

Insulin-like growth factor-binding protein-1 (BP-1) is a multifunctional protein that binds IGF-I in solution and integrins on the cell surface. BP-1 is overexpressed during catabolic illnesses, and the protein accumulates in skeletal muscle. To define a potential physiological role for BP-1 in regulating muscle protein balance, we have examined the effect of IGF-I and BP-1 on protein synthesis and degradation in human skeletal muscle cells. IGF-I-stimulated protein synthesis by 20%, and this was completely inhibited by either phosphorylated or nonphosphorylated BP-1. Half-maximal inhibition of protein synthesis occurred at a molar ratio of BP-1 to IGF-I of 1.5:1. BP-1 failed to form a complex with a truncated form of IGF-I (desIGF-I), and consequently, BP-1 failed to inhibit the ability of desIGF-I to stimulate protein synthesis. IGF-I and BP-1 dose-dependently inhibited protein degradation individually, and both BP-1 phosphovariants failed to block the ability of IGF-I to do the same. Blocking integrin receptor occupancy with the integrin antagonist echistatin blunted the ability of BP-1 to inhibit protein degradation, but had no significant effect on IGF-I-mediated changes in protein synthesis or degradation. The extracellular matrix protein vitronectin also inhibited protein degradation, but vitronectin receptor antibodies failed to block BP-1 action. In contrast, antibodies to the beta1 integrin subunit blocked BP-1-mediated inhibition of protein degradation. Rapamycin inhibited IGF-I-dependent protein synthesis, but not the ability of IGF-I to inhibit proteolysis. In contrast, rapamycin completely blocked the ability of BP-1 to inhibit proteolysis. Our results demonstrate that BP-1 inhibits IGF-I-mediated protein synthesis by binding to IGF-I. BP-1, acting independently of IGF-I, inhibits protein degradation. The IGF-independent response occurs via beta1 integrin binding and stimulation of a rapamycin-sensitive signal transduction pathway.

Lipolytic activity of anemia-inducing substance from tumor-bearing rabbits

Anemia-inducing substance (AIS) is a protein of approximately 50,000 molecular weight secreted by malignant tumor tissue that depresses erythrocyte and immuno-competent cell functions; in this study, its biological effects on adipocytes were examined. Changes in body weight, total body fat, and food intake were investigated in rabbits after VX2 carcinoma transplantation, and the results showed reductions of 11%, 24%, and 30%, respectively, at 40 days after transplantation compared with baseline values (before transplantation). The values were even more markedly reduced 70 days after transplantation. When cyclic plasma perfusion (2 times/wk) was started at 40 days after transplantation, the values at 70 days after transplantation (30 days after beginning plasma perfusion) recovered to 91%, 84%, and 87%, respectively, of the baseline values. AIS fractions were isolated from rabbit plasma by using a phenyl-Sepharose column before transplantation, 40 and 70 days after transplantation, and 30 days after start of plasma perfusion, and AIS activity and lipolytic activity were measured. The results showed enhancement of AIS activity and lipolytic activity as the tumors grew. Lipolytic activity also returned to baseline value as AIS was removed by adsorption by plasma perfusion, and there was a high correlation between lipolytic activity and AIS kinetics. These results strongly suggest that AIS might be one of the substances involved in the enhanced lipolytic activity in advanced tumor-bearing subjects.

Uncoupling of fatty acid and glucose metabolism in malignant lymphoma: a PET study

Increased use of glucose through glycolysis is characteristic for neoplastic growth while the significance of serum-free fatty acids for regulation of energy metabolism in cancer is poorly understood. We studied whether serum-free fatty acids (FFA) interfere with glycolytic metabolism of lymphoproliferative neoplasms as assessed with 2-F18-fluoro-2-deoxy-D-glucose ([F18]FDG) and positron emission tomography (PET). Twelve patients with newly diagnosed non-Hodgkin's lymphoma (n = 9) or Hodgkin's disease (n = 3) participated in this study before start of oncologic treatment. Each patient underwent two [F18]FDG PET studies within 1 week after overnight fast: once during high fasting serum FFA concentrations and once after reduction of serum FFA by administration of acipimox. Acipimox is a nicotinic acid derivative that inhibits lipolysis in peripheral tissues and induces a striking reduction in circulating FFA concentration. In all cases, dynamic PET imaging over the tumour area was performed for 60 min after injection of [F18]FDG. Both graphical analysis (rMR(FDG)) and single scan approach (SUV) were used to compare tumour uptake of [F18]FDG under high fasting FFA concentrations and after pharmacologically decreased FFA concentrations. Serum FFA concentrations were reduced significantly from 0.92+/-0.42 mmol I(-1)at baseline to 0.26+/-0.31 mmol I(-1) after acipimox administration (P = 0.0003). Plasma glucose, serum insulin and lactate concentrations were similar during both approaches. The retention of glucose analogue [F18]FDG in tumour was similar between baseline and acipimox studies. Median rMR(FDG) of a total of 12 involved lymph nodes in 12 patients was 21.9 micromol 100 g(-1) min(-1) (range 8.7-82.5) at baseline and 20.1 micromol 100 g(-1) min(-1)(range 10.7-81.7) after acipimox. The respective values for median SUV were 7.8 (range 3.6-18.6) and 6.0 (range 4.1-20.2). As expected, [F18]FDG uptake in myocardium was clearly enhanced by acipimox due to reduction of circulating FFAs. In conclusion, blood fatty acids appear to have minor significance for [F18]FDG uptake in lymphoma. This suggests that glucose utilization is uncoupled of FFA metabolism and indicates that glucose-free fatty acid cycle does not operate in lymphomatous tissue. Glucose appears to be the preferred substrate for energy metabolism in tumours, in spite of the high supply of FFAs in the fasting state. Although acipimox and other anti-lipolytic drugs have potential for treatment of catabolic state induced by cancer, they are not likely to interfere with tumour energy metabolism which is fuelled by glucose.

Effects of lifestyle and body composition on the ovary

Reduction of metabolic fuel availability below the critical level by food restriction or increased expenditure is appropriately accompanied by activations of multiple neuroendocrine-metabolic changes resulting in anovulation and amenorrhea, an important device for endogenous hypothalamic contraception. This reproductive strategy in women is required because of the enormous nutritional demand for reproductive success.

Control of neuronal size homeostasis by trophic factor-mediated coupling of protein degradation to protein synthesis

We demonstrate that NGF couples the rate of degradation of long-lived proteins in sympathetic neurons to the rate of protein synthesis. Inhibiting protein synthesis rate by a specific percentage caused an almost equivalent percentage reduction in the degradation rate of long-lived proteins, indicating nearly 1:1 coupling between the two processes. The rate of degradation of short-lived proteins was unaffected by suppressing protein synthesis. Included in the pool of proteins that had increased half-lives when protein synthesis was inhibited were actin and tubulin. Both of these proteins, which had half-lives of several days, exhibited no degradation over a 3-d period when protein synthesis was completely suppressed. The half-lives of seven other long-lived proteins were quantified and found to increase by 84-225% when protein synthesis was completely blocked. Degradation-synthesis coupling protected cells from protein loss during periods of decreased synthesis. The rate of protein synthesis greatly decreased and coupling between degradation and synthesis was lost after removal of NGF. Uncoupling resulted in net loss of cellular protein and somatic atrophy. We propose that coupling the rate of protein degradation to that of protein synthesis is a fundamental mechanism by which neurotrophic factors maintain homeostatic control of neuronal size and perhaps growth.

Nutritional support of the hospitalized patient

Comprehensive care of patients in hospitals includes assessment of nutritional status and provision of appropriate support. This approach is facilitated by knowledge of the essential differences in metabolism between starved and stressed states. Nutritional assessment and care of patients in a hospital are based on answers to the following questions: Who gets it? When do they get it? How much do they get? What route is used to administer it? What kind do they get? What are common complications of enteral and parenteral support? What nutritional aspects are pertinent to common diseases?

Serum levels of tumour necrosis factor alpha and other cytokines do not correlate with weight loss and anorexia in cancer patients

Cancer anorexia-cachexia syndrome (CACS), which is characterized by progressive weight loss (WL) and anorexia (A), is present in 50% of advanced cancer patients and in 80% of terminally ill cancer patients. One of the most controversial aspects of CACS is its oetiopathogenesis; experimental studies have identified certain cytokines [Tumour necrosis factor alpha (TNF-alpha), interleukin 1 (IL-1), interleukin 6 (IL-6), and gamma interferon (gamma-IFN)] as possible co-factors in the onset of the syndrome. The aim of our study was to investigate the correlation between serum levels of circulating cytokines and severity of CACS. The following series of parameters was identified in 61 patients with advanced and terminal cancer: stage of disease; Karnofsky performance status (KPS) and clinical symptoms; biohumoral, anthropometric and immunological situation; level of circulating cytokines. All these parameters were evaluated for a possible link with WL/A. Our data do not show any significant correlation between circulating cytokines and WL/A. A direct correlation was identified between WL/A and nausea (P = 0.03 and P < 0.001, respectively) whereas inverse correlations were observed for both factors as regards arm circumference (P < 0.001 for both), wrist circumference (P < 0.001 for both), KPS (P < 0.001 and P = 0.003, respectively) and creatinine (P = 0.005 and P = 0.03, respectively). Other biochemical factors, such as haemoglobin, haematocrit, glycaemia, prealbumin, sodium and chlorine were also correlated with at least one of two clinical parameters in question. Unexpected results were seen in the increases in CD20 and CD4 and in the CD4/CD8 ratio. Serum levels of these cytokines do not, therefore, appear to be critical in the onset of CACS. On the contrary, our findings confirmed the clinico-laboratory picture that is characteristic of CACS. If we consider the possibility that CACS is provoked by an aspecific response of the host's defence mechanisms against prolonged neoplastic attack, the increase in CD4 (helper lymphocytes) could be linked to the persistent response.

Tumor growth, weight loss and cytokines in SCID mice

It has been proposed that immunoregulatory cytokines play a role in the onset and development of cancer cachexia, although evidence supporting this theory remains inconclusive. In the present study, SCID mice were implanted with one of two tumor cell lines known to induce weight loss in rats. Growth of the Morris 7777 hepatoma was associated with weight loss as well as increased levels of tumor necrosis factor and interleukins 1 and 6 in spleen cells of tumor-bearing mice. Growth of the MCA sarcoma did not induce weight loss, nor did it increase cytokine expression in spleen cells of tumor-bearing mice. We conclude that increased cytokine expression is associated with weight loss in tumor-bearing SCID mice, and immune activation for cytokine expression does not require the presence of T or B cells.