Pathogenesis Of Cancer Cachexia Research Articles

Polygonum cuspidatum Extract (Pc-Ex) Containing Emodin Suppresses Lung Cancer-Induced Cachexia by Suppressing TCF4/TWIST1 Complex-Induced PTHrP Expression.

Cachexia, which is characterised by the wasting of fat and skeletal muscles, is the most common risk factor for increased mortality rates among patients with advanced lung cancer. PTHLH (parathyroid hormone-like hormone) is reported to be involved in the pathogenesis of cancer cachexia. However, the molecular mechanisms underlying the regulation of PTHLH expression and the inhibitors of PTHLH have not yet been identified. The PTHLH mRNA levels were measured using quantitative real-time polymerase chain reaction, while the PTHrP (parathyroid hormone-related protein) expression levels were measured using Western blotting and enzyme-linked immunosorbent assay. The interaction between TCF4 (Transcription Factor 4) and TWIST1 and the binding of the TCF4–TWIST1 complex to the PTHLH promoter were analysed using co-immunoprecipitation and chromatin immunoprecipitation. The results of the mammalian two-hybrid luciferase assay revealed that emodin inhibited TCF4–TWIST1 interaction. The effects of Polygonum cuspidatum extract (Pc-Ex), which contains emodin, on cachexia were investigated in vivo using A549 tumour-bearing mice. Ectopic expression of TCF4 upregulated PTHLH expression. Conversely, TCF4 knockdown downregulated PTHLH expression in lung cancer cells. The expression of PTHLH was upregulated in cells ectopically co-expressing TCF4 and TWIST1 when compared with that in cells expressing TCF4 or TWIST1 alone. Emodin inhibited the interaction between TCF4 and TWIST1 and consequently suppressed the TCF4/TWIST1 complex-induced upregulated mRNA and protein levels of PTHLH and PTHrP. Meanwhile, emodin-containing Pc-Ex significantly alleviated skeletal muscle atrophy and downregulated fat browning-related genes in A549 tumour-bearing mice. Emodin-containing Pc-Ex exerted therapeutic effects on lung cancer-associated cachexia by inhibiting TCF4/TWIST1 complex-induced PTHrP expression.

Role for Plant-Derived Antioxidants in Attenuating Cancer Cachexia.

Cancer cachexia is the progressive muscle wasting and weakness experienced by many cancer patients. It can compromise the response to gold standard cancer therapies, impair functional capacity and reduce overall quality of life. Cancer cachexia accounts for nearly one-third of all cancer-related deaths and has no effective treatment. The pathogenesis of cancer cachexia and its progression is multifactorial and includes increased oxidative stress derived from both the tumor and the host immune response. Antioxidants have therapeutic potential to attenuate cancer-related muscle loss, with polyphenols, a group of plant-derived antioxidants, being the most widely investigated. This review describes the potential of these plant-derived antioxidants for treating cancer cachexia.

Dietary Naringenin Preserves Insulin Sensitivity and Grip Strength and Attenuates Inflammation but Accelerates Weight Loss in a Mouse Model of Cancer Cachexia.

Cancer cachexia is characterized by the loss of skeletal muscle resulting in functional impairment, reduced quality of life and mortality. Naringenin, a flavonoid found in citrus fruits, improves insulin sensitivity and reduces inflammation and tumor growth in preclinical models. Therefore, the study hypothesizes that dietary supplementation of naringenin will improve insulin sensitivity, decrease inflammation, slow body weight loss, and delay tumor growth in a mouse model of cancer cachexia. Mice are fed 2 wt% dietary naringenin before and during initiation of cancer cachexia using inoculated adenocarcinoma-26 cells (C-26). Food intake, body weight, body composition, muscle function, insulin tolerance, and inflammatory status are assessed. Although naringenin-fed tumor-bearing mice exhibit reductions in body weight and food intake earlier than control diet-fed tumor-bearing mice, dietary naringenin is protective against loss of muscle strength, and attenuates the onset of insulin resistance and markers of inflammation. Dietary supplementation of naringenin improves multiple aspects of metabolic disturbance and inflammation during cancer cachexia progression in [C-26 tumor-bearing] mice. However, the acceleration of anorexia and weight loss is also observed. These findings emphasize the link between inflammation and insulin resistance as a basis for understanding their roles in the pathogenesis of cancer cachexia.

Brown fat does not cause cachexia in cancer patients: A large retrospective longitudinal FDG-PET/CT cohort study.

BackgroundBrown adipose tissue (BAT) is a specialized form of adipose tissue, able to increase energy expenditure by heat generation in response to various stimuli. Recently, its pathological activation has been implicated in the pathogenesis of cancer cachexia. To establish a causal relationship, we retrospectively investigated the longitudinal changes in BAT and cancer in a large FDG-PET/CT cohort.MethodsWe retrospectively analyzed 13 461 FDG-PET/CT examinations of n = 8 409 patients at our institution from the winter months of 2007–2015. We graded the activation strength of BAT based on the anatomical location of the most caudally activated BAT depot into three tiers, and the stage of the cancer into five general grades. We validated the cancer grading by an interreader analysis and correlation with histopathological stage. Ambient temperature data (seven-day average before the examination) was obtained from a meteorological station close to the hospital. Changes of BAT, cancer, body mass index (BMI) and temperature between the different examinations were examined with Spearman’s test and a mixed linear model for correlation, and with a causal inference algorithm for causality.ResultsWe found n = 283 patients with at least two examinations and active BAT in at least one of them. There was no significant interaction between the changes in BAT activation, cancer burden or BMI. Temperature changes exhibited a strong negative correlation with BAT activity (ϱ = -0.57, p<0.00001). These results were confirmed with the mixed linear model. Causal inference revealed a link of Temperature ➜ BAT in all subjects and also of BMI ➜ BAT in subjects who had lost weight and increased cancer burden, but no role of cancer and no causal links of BAT ➜ BMI.ConclusionsOur data did not confirm the hypothesis that BAT plays a major role in cancer-mediated weight loss. Temperature changes are the main driver of incidental BAT activity on FDG-PET scans.

β-Pentagalloyl-Glucose Sabotages Pancreatic Cancer Cells and Ameliorates Cachexia in Tumor-Bearing Mice.

Pancreatic cancer cells overexpress the insulin receptor (IR) and the insulin-like growth factor-1 receptor (IGF1R). Activating these receptors, insulin and insulin-like growth factor-1 increase the growth and glycolysis of pancreatic cancer cells. The high glycolysis in pancreatic cancer cells increases whole-body energy expenditure and is therefore involved in the pathogenesis of cancer cachexia. The antagonism of IR and IGF1R may sabotage pancreatic cancer cells and attenuate cancer cachexia. Previous studies have shown that the intracellular regulating system of IR/IGF1R may be functionally interrelated to another intracellular system whose master regulator is hypoxia-inducible factor-1 (HIF-1). In this study, we investigated how the IR/IGF1R and HIF-1 systems are interrelated in pancreatic cancer cells. We also investigated whether a phytochemical, penta-O-galloyl- -D-glucose ( -PGG), antagonizes IR/IGF1R, sabotages pancreatic cancer cells and alleviates cancer cachexia. We found in MiaPaCa2 pancreatic cancer cells that IR/IGF1R activation increased both the -subunit of HIF-1 and caveolin-1. This result suggests that IR/IGF1R, HIF-1 , and caveolin-1 may constitute a feed-forward loop to mediate the effect of IR/IGF1R activation. -PGG inhibited IR/IGF1R activity and decreased glycolytic enzymes in MiaPaCa2 and Panc-1 pancreatic cancer cells. When MiaPaCa2 cells were transplanted in athymic mice, their growth was inhibited by -PGG or by a HIF-1 inhibitor, rhein. -PGG and rhein also decreased glycolytic enzymes in the tumor grafts and reduced liver gluconeogenesis, skeletal-muscle proteolysis and fat lipolysis in the tumor carriers. Cancer-induced body-weight loss, however, was prevented by -PGG but not rhein. In conclusion, -PGG combats pancreatic cancer cells and cures cancer cachexia.

Retraction: Myostatin is a novel tumoral factor that induces cancer cachexia.

Humoral and tumoral factors collectively promote cancer-induced skeletal muscle wasting by increasing protein degradation. Although several humoral proteins, namely TNFα (tumour necrosis factor α) and IL (interleukin)-6, have been shown to induce skeletal muscle wasting, there is a lack of information regarding the tumoral factors that contribute to the atrophy of muscle during cancer cachexia. Therefore, in the present study, we have characterized the secretome of C26 colon cancer cells to identify the tumoral factors involved in cancer-induced skeletal muscle wasting. In the present study, we show that myostatin, a procachectic TGFβ (transforming growth factor β) superfamily member, is abundantly secreted by C26 cells. Consistent with myostatin signalling during cachexia, treating differentiated C2C12 myotubes with C26 CM (conditioned medium) resulted in myotubular atrophy due to the up-regulation of muscle-specific E3 ligases, atrogin-1 and MuRF1 (muscle RING-finger protein 1), and enhanced activity of the ubiquitin–proteasome pathway. Furthermore, the C26 CM also activated ActRIIB (activin receptor type II B)/Smad and NF-κB (nuclear factor κB) signalling, and reduced the activity of the IGF-I (insulin-like growth factor 1)/PI3K (phosphoinositide 3-kinase)/Akt pathway, three salient molecular features of myostatin action in skeletal muscles. Antagonists to myostatin prevented C26 CM-induced wasting in muscle cell cultures, further confirming that tumoral myostatin may be a key contributor in the pathogenesis of cancer cachexia. Finally, we show that treatment with C26 CM induced the autophagy–lysosome pathway and reduced the number of mitochondria in myotubes. These two previously unreported observations were recapitulated in skeletal muscles collected from C26 tumour-bearing mice.

Cancer Cachexia: One Step Ahead

Cachexia is one of the most common manifestations in advanced cancer patients, but too often it remains under- recognized and under-treated. Starvation is not the same of cachexia. Cachexia is defined by "weight loss >5% over past 6 months in absence of simple starvation or the combination of ongoing weight loss>2% with BMI <20 or sarcopenia". The pathogenesis of cancer cachexia is not fully understood, but inflammation and an increased catabolic response to a number of cancer-related factors seem to represent the basis of any assumption. Early diagnosis of a pre-cachectic or cachectic state is a key moment for the treatment of this complex syndrome, in order to guarantee an adequate food intake and suitable exercise and to interfere with the inflammatory processes that are typical of cachexia. Therefore, one of the main aims is to identify those patients most likely to develop the syndrome early. A multimodality baseline approach to cancer cachexia addresses reversible clinical contributory factors. There are currently no medicinal products that have a proven efficacy in the medical approach to cancer cachexia. Recently, anamorelin, a synthetic orally active ghrelin receptor agonist, showed promising results, but the best approach to cancer cachexia probably remains an early multimodal interventions consisting in nutritional intervention, exercise and rehabilitation program, and multi-target drug therapies. This review summarizes what we know and what still need to know about cancer cachexia syndrome.

Myostatin gene inactivation prevents skeletal muscle wasting in cancer.

Cachexia is a muscle-wasting syndrome that contributes significantly to morbidity and mortality of many patients with advanced cancers. However, little is understood about how the severe loss of skeletal muscle characterizing this condition occurs. In the current study, we tested the hypothesis that the muscle protein myostatin is involved in mediating the pathogenesis of cachexia-induced muscle wasting in tumor-bearing mice. Myostatin gene inactivation prevented the severe loss of skeletal muscle mass induced in mice engrafted with Lewis lung carcinoma (LLC) cells or in Apc(Min) (/+) mice, an established model of colorectal cancer and cachexia. Mechanistically, myostatin loss attenuated the activation of muscle fiber proteolytic pathways by inhibiting the expression of atrophy-related genes, MuRF1 and MAFbx/Atrogin-1, along with autophagy-related genes. Notably, myostatin loss also impeded the growth of LLC tumors, the number and the size of intestinal polyps in Apc(Min) (/+) mice, thus strongly increasing survival in both models. Gene expression analysis in the LLC model showed this phenotype to be associated with reduced expression of genes involved in tumor metabolism, activin signaling, and apoptosis. Taken together, our results reveal an essential role for myostatin in the pathogenesis of cancer cachexia and link this condition to tumor growth, with implications for furthering understanding of cancer as a systemic disease.

Abstract 2680: Inhibition of activin-like kinases 4 and 5 attenuates cancer cachexia associated muscle wasting

Abstract Background: Cancer cachexia has a detrimental effect on patient survival. Cachectic patients experience reduced quality of life and have a decreased survival time. The underlying mechanism behind cancer cachexia is not yet fully understood. Recent experimental data suggests myostatin signaling may be a key contributor in the pathogenesis of cancer cachexia. Activin receptor IIB / activin-like kinase 4/5 heterodimer activation by myostatin leads to catabolic muscle degradation. SB-431542 is a potent inhibitor of activin-like kinases 4 and 5. We aimed to assess its potential in the treatment of cancer cachexia in an experimental rodent model. Methods: All experiments were approved by the local Animal Ethics Committee. 24 CD2F1 were inoculated subcutaneously with 0.5 x 106 colon-26 murine adenocarcinoma cells to induce cachexia. The mice were allocated randomly into one of four experimental groups: healthy control, tumor-bearing control, tumor-bearing vehicle treated and tumor-bearing SB-431542 treated. All mice were weighed daily. Tumor size was assessed every other day, starting day 9 post inoculation. Four-paw grip strength was determined weekly using a grip-strength meter. SB-431542 was reconstituted in DMSO 1 mg/mL. From day 5 post inoculation, allocated mice received 10 mg/kg SB-431542, or vehicle intraperitoneally until sacrifice on day 20. Results: All tumor-bearing mice had a reduction in body weight compared to controls, 21.1 ± 2.1 g versus 30.0 ± 1.3 g respectively (p &amp;lt; 0.0001). No differences in body weight were found between the tumor-bearing groups. Despite weight loss, SB-431542 treated animals had no reduction in grip strength. Grip strength directly after tumor inoculation was 200.9 ± 11.3 g, and on day 14 211.3 ± 20.4 g. Vehicle treated animals showed a reduction from 204.0 ± 19.1 g to 174.8 ± 13.7 g (p = 0.0158). Mean wet muscle weight of the m. tibialis anterior was significantly preserved in SB-431542 treated animals versus tumor-bearing vehicle treated animals (53.8 mg vs. 40.5 mg, p = 0.0171) as well as tumor-bearing untreated animals (53.8 mg vs. 34.7 mg, p = 0.0002). Conclusion: These findings suggest that inhibition of activin-like kinases 4 and 5 by SB-431542 attenuates cancer cachexia associated muscle loss and loss of muscle force in experimental cancer cachexia, and further emphasizes the role of myostatin/activin signaling. Citation Format: Stef Levolger, Ron W.F. de Bruin, Jan N.M. IJzermans. Inhibition of activin-like kinases 4 and 5 attenuates cancer cachexia associated muscle wasting. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2680. doi:10.1158/1538-7445.AM2014-2680

Myostatin is a novel tumoral factor that induces cancer cachexia

Humoral and tumoral factors collectively promote cancer-induced skeletal muscle wasting by increasing protein degradation. Although several humoral proteins, namely TNFα (tumour necrosis factor α) and IL (interleukin)-6, have been shown to induce skeletal muscle wasting, there is a lack of information regarding the tumoral factors that contribute to the atrophy of muscle during cancer cachexia. Therefore, in the present study, we have characterized the secretome of C26 colon cancer cells to identify the tumoral factors involved in cancer-induced skeletal muscle wasting. In the present study, we show that myostatin, a procachectic TGFβ (transforming growth factor β) superfamily member, is abundantly secreted by C26 cells. Consistent with myostatin signalling during cachexia, treating differentiated C2C12 myotubes with C26 CM (conditioned medium) resulted in myotubular atrophy due to the up-regulation of muscle-specific E3 ligases, atrogin-1 and MuRF1 (muscle RING-finger protein 1), and enhanced activity of the ubiquitin–proteasome pathway. Furthermore, the C26 CM also activated ActRIIB (activin receptor type II B)/Smad and NF-κB (nuclear factor κB) signalling, and reduced the activity of the IGF-I (insulin-like growth factor 1)/PI3K (phosphoinositide 3-kinase)/Akt pathway, three salient molecular features of myostatin action in skeletal muscles. Antagonists to myostatin prevented C26 CM-induced wasting in muscle cell cultures, further confirming that tumoral myostatin may be a key contributor in the pathogenesis of cancer cachexia. Finally, we show that treatment with C26 CM induced the autophagy–lysosome pathway and reduced the number of mitochondria in myotubes. These two previously unreported observations were recapitulated in skeletal muscles collected from C26 tumour-bearing mice.

Update on emerging drugs for cancer cachexia

Cancer cachexia is a complex syndrome that describes the progressive muscle wasting and weakness in many cancer patients. Muscle wasting reduces the ability of affected patients to perform the tasks of daily living and causes severe fatigue, leading to a reduction in quality of life. Cancer cachexia reduces patient response to anti-neoplastic treatments, increases the risk of postoperative complications and accounts for > 20% of cancer-related deaths. The pathogenesis of cancer cachexia is multifactorial and includes anorexia, inflammation, metabolic disturbances and enhanced muscle proteolysis, and each of these presents as a potential therapeutic target for ameliorating cancer cachexia. Objective: This review provides an update on some of the emerging drugs for cancer cachexia. Methods: This is a review of the current status of emerging therapies for cancer cachexia. Results: An increasing number of studies are focused on the development of novel therapies for cancer cachexia. Initial studies concentrated on the treatment of anorexia, but now aim to attenuate inflammation or muscle proteolysis, or to use different drugs in combination so as to treat several aspects of cachexia simultaneously. Conclusions: There are several existing and emerging drugs with the potential to ameliorate cancer cachexia, but the most efficacious treatment will probably come from combined drug therapies.

Cancer cachexia demonstrates the energetic impact of gluconeogenesis in human metabolism

A review-based hypothesis is presented on the energy flow in cancer patients. This hypothesis centres on the hypoxic condition of tumours, the essential metabolic consequences, especially the gluconeogenesis, the adaptation of the body, and the pathogenesis of cancer cachexia. In growing tumours the O(2) concentration is critically low. Mammalian cells need O(2) for the efficient oxidative dissimilation of sugars and fatty acids, which gives 38 and 128 moles of ATP per mole glucose and palmitic acid, respectively. In the absence of sufficient O(2) they have to switch to anaerobic dissimilation, with only 2 moles of ATP and 2 moles of lactic acid from 1 mole of glucose. Since mammalian cells cannot ferment fatty acids, in vivo tumour cells completely depend on glucose fermentation. Therefore, growth of these tumour cells will require about 40 times more glucose than it should require in the presence of sufficient O(2). Since lactic acid lowers the intracellular pH, it decreases the activity of pyruvate dehydrogenase, stimulates fermentation, and thus amplifies its own fermentative production. Compensatory glucose is provided by hepatic gluconeogenesis from lactic acid. However, the liver must invest 3 times more energy to synthesize glucose than can be extracted by tumour cells in an anaerobic way. The liver extracts the required energy from amino acids and especially from fatty acids in an oxidative way. This may account for weight loss, even when food intake seems adequate. In the liver 6 moles of ATP are invested in the gluconeogenesis of one mole of glucose. The energy content of 4 out of these 6 moles of ATP is dissipated as heat. This may account for the elevated body temperature and sweating experience by cancer patients.

Cancer-associated malnutrition

Malnutrition is a common problem among patients with cancer, affecting up to 85% of patients with certain cancers (e.g. pancreas). In severe cases, malnutrition can progress to cachexia, a specific form of malnutrition characterised by loss of lean body mass, muscle wasting, and impaired immune, physical and mental function. Cancer cachexia is also associated with poor response to therapy, increased susceptibility to treatment-related adverse events, as well as poor outcome and quality of life. Cancer cachexia is a complex, multifactorial syndrome, which is thought to result from the actions of both host- and tumour-derived factors, including cytokines involved in a systemic inflammatory response to the tumour. Early intervention with nutritional supplementation has been shown to halt malnutrition, and may improve outcome in some patients. However, increasing nutritional intake is insufficient to prevent the development of cachexia, reflecting the complex pathogenesis of this condition. Nutritional supplements containing anti-inflammatory agents, for example the polyunsaturated fatty acid (PUFA) eicosapentanoic acid (EPA), have been shown to be more beneficial to malnourished patients than nutritional supplementation alone. EPA has been shown to interfere with multiple mechanisms implicated in the pathogenesis of cancer cachexia, and in clinical studies, has been associated with reversal of cachexia and improved survival.

Cytokines in the pathogenesis of cancer cachexia.

The aim of the present review is to summarize and update the role of different cytokines in the pathogenesis of cancer cachexia and to provide therapeutic strategies based on cytokine action. Cancer cachexia is a syndrome characterized by a marked weight loss, anorexia, asthenia and anemia. The cachectic state is invariably associated with the presence and growth of the tumor and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumor and the host leads to an accelerated starvation state which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. Different cytokines are clearly implicated in this process, possibly being responsible for anorexia, hypermetabolism and many other metabolic abnormalities, such as muscle proteolysis and apoptosis. Although the search for the cachectic factor(s) started a long time ago, and although many scientific and economic efforts have been devoted to its discovery, we are still a long way from knowing the whole truth. A lot of progress has been made, however, in understanding the role of different cytokines - tumor necrosis factor and IL-6 in particular - in muscle wasting associated with cancer cachexia, perhaps the most paradigmatic feature of this complex syndrome.

Role of NF-kappaB and cytokine in experimental cancer cachexia.

To assess the putative involvement of NF-kappaB and pro-inflammatory cytokines in the pathogenesis of cancer cachexia and the therapeutic efficacy of indomethacin (IND) on cachexia. Thirty young male BABL/c mice were divided randomly into five groups: (a) control, (b) tumor-bearing plus saline, (c) tumor-bearing plus IND (0.25 mg x kg(-1)), (d) tumor-bearing plus IND (0.5 mg x kg(-1)), and (e) tumor-bearing plus IND (2 mg x kg(-1)). Colon 26 adenocarcinoma cells of murine were inoculated subcutaneously to induce cachexia. Saline and IND were given intraperitoneally daily for 7 days from the onset of cachexia to sacrifice. Food intake and body composition were documented, serum levels of TNF-alpha and IL-6 and activity of NF-kappaB in the spleen were investigated in all animals. Weight loss was observed in all tumor-bearing mice. By day 16, body weights of non-tumor mice were about 72 % of healthy controls (P<0.01), and the weight of gastrocnemius was decreased by 28.7 % (P<0.01). No difference was found between groups in food intake (P>0.05). Gastrocnemius weight was increased markedly (P<0.01) after treatment of IND (0.5 mg x kg(-1)), while the non-tumor body weights were not significantly elevated. Tumor-bearing caused a 2-3 fold increase in serum levels of both TNF-alpha and IL-6 (P<0.01). The concentration of TNF-alpha (P<0.05) and IL-6 (P<0.01) in tumor-bearing mice was reduced after administration of 0.5 mg x kg(-1) IND for 7 days. But the level of IL-6 was slightly elevated following treatment of IND 2.0 mg x kg(-1). NF-kappaB activation in the spleen was increased in tumor-bearing mice in comparison with controls in electrophoretic mobility shift assay (EMSA). NF-kappaB activity was reduced in mice treated with 0.5 mg x kg(-1) of IND, whereas a higher NF-kappaB activity was observed in mice treated with 2.0 mg x kg(-1) of IND. Colon 26 adenocarcinoma cells can induce severe cancer cachexia experimentally, and the mechanism may be partially due to the enhanced TNF-alpha and IL-6 in tumor-bearing animals, which is controlled by NF-kappaB. Low dose of indomethacin alleviates the cachexia, decreases the activation of NF-kappaB and the serum levels of TNF-alpha and IL-6, and prevents body weight loss and muscle atrophy, while no further effect is gained by a higher dosage.

Biological activity of a novel nonpeptide antagonist to the interleukin-6 receptor 20S,21-epoxy-resibufogenin-3-formate.

Interleukin (IL)-6 is a key mediator in the regulation and coordination of the immune response and participates in pathogenesis of cancer cachexia, autoimmune disease, and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from natural products, we isolated 20S,21-epoxy-resibufogenin-3-formate (ERBF) from bufadienolide and examined the effect of ERBF on activities of various cytokines. ERBF dose dependently suppressed IL-6 activity and caused a parallel rightward shift of dose-response curves to IL-6 at concentrations of 0.03 to 10 ng/ml. Analysis of data yields a pA(2) of 5.12 and a slope of 0.99. Selectivity of ERBF on activity of cytokines was examined using cytokine-dependent cell lines. ERBF did not affect IL-2-dependent growth of CTLL-2 cells, IL-3-dependent growth of Baf3 cells, or tumor necrosis factor (TNF)alpha-induced growth suppression in TNFalpha-sensitive L929 cells. ERBF also did not affect IL-4-stimulated expression of FcepsilonR II receptor (CD23) in U-937 cells, the IL-8-induced chemotaxis of human neutrophils, or nerve growth factor-stimulated neuronal differentiation in PC-12 cells. In contrast, ERBF dose dependently suppressed IL-6-induced neuronal differentiation in PC-12 cells. Furthermore, ERBF suppressed only IL-6-induced osteoclast formation without affecting osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). In receptor binding assay, unbound (free) IL-6 was increased in a dose-dependent manner by pretreatment with ERBF on IL-6 receptor (IL-6R), suggesting that ERBF suppresses binding of IL-6 to IL-6R. These results clearly indicate that ERBF is a novel specific small molecule to show IL-6 receptor antagonist activity.

CYTOKINE LEVELS (IL-6 AND IFN-γ), ACUTE PHASE RESPONSE AND NUTRITIONAL STATUS AS PROGNOSTIC FACTORS IN LUNG CANCER

Raised serum levels of interleukin 6 (IL-6) have been described in cancer patients. This cytokine mediates the acute phase response and has been also involved in the pathogenesis of cancer cachexia. The objectives of the present study were: (1) to determine the relationships of IL-6 and other cytokines with neoplasia extension, acute phase response and nutritional status, in lung cancer patients; and (2) to establish the prognostic value of serum cytokine levels. A prospective study in which IL-1, IL-2, IL-6, tumour necrosis factor α (TNF-α) and interferon γ (IFN-γ) have been determined in 66 newly diagnosed lung cancer patients. Nutritional status was assessed objectively. Serum levels of growth hormone (GH), insulin growth factor 1 (IGF-1) and acute phase reactants as C Reactive Protein, α1 antitrypsin and ferritine, were determined. Increased IL-6 levels were related to extensive disease, impaired performance status, enhanced acute phase response and malnutrition. Raised serum IL-6 levels, extensive disease, low Karnofsky index, malnutrition, acute phase response and low IFN-γ were all related to a shorter survival. When assessed by a multivariate analysis, IL-6 kept its independent prognostic value together with age, disease extension, and decreased IFN-γ serum levels.IL-6 is increased in lung cancer patients, enhances the acute phase response in them, and is correlated with poor nutritional status, impaired performance status and shorter survival.

Plasma neopterin/C-reactive protein ratio as an adjunct to the assessment of infection and cancer cachexia.

Neopterin (NPT), a pteridine intermediate metabolite in the biopterine synthetic pathway, is synthesized and secreted by monocytes/macrophages upon stimulation, mainly by gamma-interferon produced by activated T cells. C-reactive protein (CRP) is one of the major acute-phase reactants and its release is thought to be mediated by interleukin-6. Plasma concentrations of NPT and CRP were synchronously analyzed in 25 determinations of 5 patients with severe infectious complications and 50 determinations of 10 cancer-burden patients representing cachexia. The mean value of NPT (pmol/ml) was 201.6 in the infection group and 16.5 in the cancer cachexia group. The mean value of CRP (mg/dl) was 12.5 in the infection group and 3.4 in the cancer cachexia group. The number of samples in which NPT alone exceeded the cut-off level were 0/25 (0%) in the infection group and 38/50 (76.0%) in the cancer cachexia group. The number of samples in which both NPT and CRP exceeded the cut-off level was 25/25 (100%) in the infection group and 12/50 (24.0%) in the cancer cachexia group. The mean ratio of NPT to CRP was 11.3 in the infection group and 30.7 in the cancer cachexia group, respectively. These results suggest that gamma-interferon could play the principal role in the pathogenesis of cancer cachexia and that interleukin-6 modified the disease status. Interleukin-6 would be the critical mediator of host responses in infectious complications.

ANOREXIA IN PATIENTS WITH CANCER WITH SPECIAL REFERENCES ON ITS ASSOCIATION WITH EARLY CHANGES IN FOOD-INTAKE BEHAVIOR CHEMOTHERAPEUTIC TREATMENT AND ADJUVANT ENTERAL NUTRITION (REVIEW)

Anorexia defined as decreased appetite resulting in fatigue, change of body image and weight loss is stated to be fundamental to the syndrome of cancer cachexia. Weight loss is the most apparent symptom of anorexia and cachexia, and occurs quite frequently in patients with cancer. Interest in the pathogenetic mechanisms, is due to the strong association between weight loss and lower duality and quantity of life. This review discusses anorexia in the pathogenesis of cancer cachexia, particularly the effect of taste alterations and chemotherapy; and the long-term acceptability and effect of oral nutritional support and drug therapy.

Down-regulation of tumor necrosis factor expression by pentoxifylline in cancer patients: a pilot study.

The wasting syndrome (cachexia) characterized by anorexia, malaise, and weight loss is observed in many patients with cancer or chronic infection. The excessive levels of tumor necrosis factor-alpha (TNF)/cachectin reported in 50% of cancer patients exhibiting clinically active disease may therefore mediate, at least in part, the cachexia associated with malignancy. Pentoxifylline, a substituted methylxanthine approved for treatment of intermittent claudication, has been shown in preclinical studies to down-regulate TNF RNA expression as well as TNF activity. We report that pentoxifylline suppressed TNF RNA levels on all three occasions in patients with initially elevated levels of TNF RNA. Pentoxifylline did not suppress TNF RNA to subnormal levels in all five patients with initially normal TNF RNA levels. Four patients reported an increased sense of well-being, improved appetite and ability to perform the activities of daily living. Two of these five patients with normal TNF levels each had a weight gain of more than 5% after 3 weeks of pentoxifylline therapy suggesting that, although TNF may be important in the pathogenesis of cancer cachexia, other anorexia-producing cytokines that are potentially affected by pentoxifylline may also be involved. No severe adverse effects were observed. Taken together these findings suggest that pentoxifylline can down-regulate TNF expression and improve the sense of well-being in cancer patients. A larger study with a randomized, double-blind, placebo-controlled design and more sophisticated estimates of quality of life will be needed to confirm these observations.