Suppression of cancer cachexia by 20S,21-epoxy-resibufogenin-3-acetate—a novel nonpeptide IL-6 receptor antagonist

Evaluation of the Tocilizumab therapy in human cancers: Latest evidence and clinical potential

Tocilizumab (Actemra®), as the first human interleukin-6 receptor (IL-6R) antagonist, has been used in treating moderate to severe active rheumatoid arthritis (RA) patients who were undertreatment with one or more disease-modifying anti-rheumatic drugs (DMARDs) and did not improve significantly. Tocilizumab also has been administrated and confirmed in several inflammatory-based diseases. Recently, tocilizumab has been prescribed to treat patients with advanced coronavirus disease (COVID-19) and is used as one of the effective drugs in reducing the increased inflammation in these patients. On the other hand, cancer treatment has been considered by researchers one of the most important challenges to human health. Regarding inflammatory-associated malignancies, it has been shown that inflammatory mediators such as interleukin-1 beta (IL-1β), IL-6, and tumour necrosis factor-alpha (TNF-α) may play a role in tumorigenesis, thus targeting these cytokines as evidence suggested can be useful in the treatment of these types of cancers. This review summarized the role of the IL-6/IL-6R axis in inflammation-based cancers and discussed the effectiveness and challenges of treating cancer with tocilizumab.

New-Generation Heterocyclic Bis-Pentamethinium Salts as Potential Cytostatic Drugs with Dual IL-6R and Mitochondria-Targeting Activity

IL-6 signaling is involved in the pathogenesis of a number of serious diseases, including chronic inflammation and cancer. Targeting of IL-6 receptor (IL-6R) by small molecules is therefore an intensively studied strategy in cancer treatment. We describe the design, synthesis, and characteristics of two new bis-pentamethinium salts 5 and 6 (meta and para) bearing indole moieties. Molecular docking studies showed that both compounds have the potential to bind IL-6R (free energy of binding −9.5 and −8.1 kcal/mol). The interaction with IL-6R was confirmed using microscale thermophoresis analyses, which revealed that both compounds had strong affinity for the IL-6R (experimentally determined dissociation constants 26.5 ± 2.5 nM and 304 ± 27.6 nM, respectively). In addition, both compounds were cytotoxic for a broad spectrum of cancer cell lines in micromolar concentrations, most likely due to their accumulation in mitochondria and inhibition of mitochondrial respiration. In summary, the structure motif of bis-pentamethinium salts represents a promising starting point for the design of novel multitargeting compounds with the potential to inhibit IL-6 signaling and simultaneously target mitochondrial metabolism in cancer cells.

Clinical Relevance of Myopenia and Myosteatosis in Colorectal Cancer

Sarcopenia was initially described as a decrease in muscle mass associated with aging and subsequently also as a consequence of underlying disease, including advanced malignancy. Accumulating evidence shows that sarcopenia has clinically significant effects in patients with malignancy, including an increased risk of adverse events associated with medical treatment, postoperative complications, and a poor survival outcome. Colorectal cancer (CRC) is one of the most common cancers worldwide, and several lines of evidence suggest that preoperative sarcopenia negatively impacts various outcomes in patients with CRC. In this review, we summarize the current evidence in this field and the clinical relevance of sarcopenia in patients with CRC from three standpoints, namely, the adverse effects of medical treatment, postoperative infectious complications, and oncological outcomes.

Small molecule approaches to treat autoimmune and inflammatory diseases (Part III): Targeting cytokines and cytokine receptor complexes

Chronic and dysregulated cytokine signaling plays an important role in the pathogenic development of many autoimmune and inflammatory diseases. Despite intrinsic challenges in the disruption of interactions between cytokines and cytokine receptors, many first-in-class small-molecule inhibitors have been discovered over the past few years. The third part of the digest series presents recent progress in identifying such inhibitors and highlights the application of novel research tools in the fields of structural biology, computational analysis, screening methods, biophysical/biochemical assays and medicinal chemistry strategy.

Establishment and Verification of a Prediction Model for Symptomatic Radiation Pneumonitis in Patients with Esophageal Cancer Receiving Radiotherapy

BACKGROUND This study aimed to determine the value of the significant index in predicting symptomatic radiation pneumonitis (RP) in esophageal cancer patients, establish a nomogram prediction model, and verify the model. MATERIAL AND METHODS The patients enrolled were divided into 2 groups: a model group and a validation group. According to the logistic regression analysis, the independent predictors for symptomatic RP were obtained, and the nomogram prediction model was established according to these independent predictors. The consistency index (C-index) and calibration curve were used to evaluate the accuracy of the model, and the prediction ability of the model was verified in the validation group. Recursive partitioning analysis (RPA) was used for the risk stratification analysis. RESULTS The ratio of change regarding the pre-albumin at the end of treatment (P=0.001), platelet-to-lymphocyte ratio during treatment (P=0.027), and neutrophil-to-lymphocyte ratio at the end of treatment (P=0.001) were the independent predictors for symptomatic RP. The C-index of the nomogram model was 0.811. According to the risk stratification of RPA, the whole group was divided into 3 groups: a low-risk group, a medium-risk group, and a high-risk group. The incidence of symptomatic RP was 0%, 16.9%, and 57.6%, respectively. The receiver operating characteristic curve also revealed that the nomogram model has good accuracy in the validation group. CONCLUSIONS The developed nomogram and corresponding risk classification system have superior prediction ability for symptomatic RP and can predict the occurrence of RP in the early stage.

Interleukin-6: Molecule in the Intersection of Cancer, Ageing and COVID-19

Interleukin-6 (IL-6) is a cytokine with multifaceted effects playing a remarkable role in the initiation of the immune response. The increased level of this cytokine in the elderly seems to be associated with the chronic inflammatory setting of the microenvironment in aged individuals. IL-6 also represents one of the main signals in communication between cancer cells and their non-malignant neighbours within the tumour niche. IL-6 also participates in the development of a premetastatic niche and in the adjustment of the metabolism in terminal-stage patients suffering from a malignant disease. IL-6 is a fundamental factor of the cytokine storm in patients with severe COVID-19, where it is responsible for the fatal outcome of the disease. A better understanding of the role of IL-6 under physiological as well as pathological conditions and the preparation of new strategies for the therapeutic control of the IL-6 axis may help to manage the problems associated with the elderly, cancer, and serious viral infections.

Exercise as an anti-inflammatory therapy for cancer cachexia: a focus on interleukin-6 regulation

Cancer cachexia is a complicated disorder of extreme, progressive skeletal muscle wasting. It is directed by metabolic alterations and systemic inflammation dysregulation. Numerous studies have demonstrated that increased systemic inflammation promotes this type of cachexia and have suggested that cytokines are implicated in the skeletal muscle loss. Exercise is firmly established as an anti-inflammatory therapy that can attenuate or even reverse the process of muscle wasting in cancer cachexia. The interleukin IL-6 is generally considered to be a key player in the development of the microenvironment of malignancy; it promotes tumor growth and metastasis by acting as a bridge between chronic inflammation and cancerous tissue and it also induces skeletal muscle atrophy and protein breakdown. Paradoxically, a beneficial role for IL-6 has also been identified recently, and that is its status as a “founding member” of the myokine class of proteins. Skeletal muscle is an important source of circulating IL-6 in people who participate in exercise training. IL-6 acts as an anti-inflammatory myokine by inhibiting TNFα and improving glucose uptake through the stimulation of AMPK signaling. This review discusses the action of IL-6 in skeletal muscle tissue dysfunction and the role of IL-6 as an “exercise factor” that modulates the immune system. This review also sheds light on the main considerations related to the treatment of muscle wasting in cancer cachexia.

Inhibitory Effects of Compounds and Extracts from Ampelopsis brevipedunculata on IL-6-Induced STAT3 Activation

Ampelopsis brevipedunculata (Maxim.) Trautv. (AB), a traditional East Asian medicine, exhibits protective effects against several inflammatory diseases. Our search for an inhibitor of IL-6-induced JAK2/STAT3 activation revealed that AB ethanolic extract (ABE) had a significant inhibitory effect on IL-6-induced STAT3 expression in Hep3B cells. The isolation and purification of an EtOAc-soluble fraction of ABE (ABEA) using reversed-phase high-performance liquid chromatography (RP-HPLC) afforded 17 compounds. The structures of these compounds (1-17) were elucidated based on ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy as well as electrospray-ionization mass spectrometry (ESI-MS) data. ABE and ABEA were screened by a luciferase assay using Hep3B cells transfected with the STAT3 reporter gene. ABEA exhibited potent inhibitory effects on IL-6-induced STAT3 expression; moreover, these effects arose from the inhibition of the phosphorylation of the STAT3, JAK2, and ERK proteins in U266 cells. In addition, the compounds isolated from ABEA were measured for their inhibitory effects on IL-6-stimulated STAT3 expression. Of the compounds isolated, betulin showed the greatest inhibitory effects on IL-6-induced STAT3 activation in the luciferase assay (IC₅₀ value: 3.12 μM). Because of its potential for inhibiting STAT3 activation, A. brevipedunculata could be considered a source of compounds of pharmaceutical interest.

Potential therapeutic implications of IL-6/IL-6R/gp130-targeting agents in breast cancer

Interleukin-6 (IL-6) is a pleiotropic cytokine with known multiple functions in immune regulation, inflammation, and oncogenesis. Binding of IL-6 to the IL-6 receptor (IL-6R) induces homodimerization and recruitment of glycoprotein 130 (gp130), which leads to activation of downstream signaling. Emerging evidence suggests that high levels of IL-6 are correlated with poor prognosis in breast cancer patients. IL-6 appears to play a critical role in the growth and metastasis of breast cancer cells, renewal of breast cancer stem cells (BCSCs), and drug resistance of BCSCs, making anti-IL-6/IL-6R/gp130 therapies promising options for the treatment and prevention of breast cancers. However, preclinical and clinical studies of the applications of anti-IL-6/IL-6R/gp130 therapy in breast cancers are limited. In this review, we summarize the structures, preclinical and clinical studies, mechanisms of action of chemical and biological blockers that directly bind to IL-6, IL-6R, or gp130, and the potential clinical applications of these pharmacological agents as breast cancer therapies.

Tumor-related interleukins: old validated targets for new anti-cancer drug development

In-depth knowledge of cancer molecular and cellular mechanisms have revealed a strong regulation of cancer development and progression by the inflammation which orchestrates the tumor microenvironment. Immune cells, residents or recruited, in the inflammation milieu can have rather contrasting effects during cancer development. Accumulated clinical and experimental data support the notion that acute inflammation could exert an immunoprotective effect leading to tumor eradication. However, chronic immune response promotes tumor growth and invasion. These reactions are mediated by soluble mediators or cytokines produced by either host immune cells or tumor cells themselves. Herein, we provide an overview of the current understanding of the role of the best-validated cytokines involved in tumor progression, IL-1, IL-4 and IL-6; in addition to IL-2 cytokines family, which is known to promote tumor eradication by immune cells. Furthermore, we summarize the clinical attempts to block or bolster the effect of these tumor-related interleukins in anti-cancer therapy development.

Dual Inhibition of MEK and PI3K/Akt Rescues Cancer Cachexia through both Tumor-Extrinsic and -Intrinsic Activities

Involuntary weight loss, a part of the cachexia syndrome, is a debilitating comorbidity of cancer and currently has no treatment options. Results from a recent clinical trial at our institution showed that biliary tract cancer patients treated with a MEK inhibitor exhibited poor tumor responses but surprisingly gained weight and increased their skeletal muscle mass. This implied that MEK inhibition might be anticachectic. To test this potential effect of MEK inhibition, we utilized the established Colon-26 model of cancer cachexia and the MEK1/2 inhibitor MEK162. Results showed that MEK inhibition effectively prevented muscle wasting. Importantly, MEK162 retained its ability to spare muscle loss even in mice bearing a Colon-26 clone resistant to the MEK inhibitor, demonstrating that the effects of blocking MEK are at least in part independent of the tumor. Because single-agent MEK inhibitors have been limited as a first-line targeted therapy due to compensatory activation of other oncogenic signaling pathways, we combined MEK162 with the PI3K/Akt inhibitor buparlisib. Results showed that this combinatorial treatment significantly reduced tumor growth due to a direct activity on Colon-26 tumor cells in vitro and in vivo, while also preserving skeletal muscle mass. Together, our results suggest that as a monotherapy, MEK inhibition preserves muscle mass, but when combined with a PI3K/Akt inhibitor exhibits potent antitumor activity. Thus, combinatorial therapy might serve as a new approach for the treatment of cancer cachexia. Mol Cancer Ther; 16(2); 344-56. ©2016 AACRSee related article by Kobayashi et al., p. 357.

4-Hydroxyhexenal and 4-hydroxynonenal are mediators of the anti-cachectic effect of n-3 and n-6 polyunsaturated fatty acids on human lung cancer cells

Cachexia, the most severe paraneoplastic syndrome, occurs in about 80% of patients with advanced cancer; it cannot be reverted by conventional, enteral, or parenteral nutrition. For this reason, nutritional interventions must be based on the use of substances possessing, alongside nutritional and energetic properties, the ability to modulate production of the pro-inflammatory factors responsible for the metabolic changes characterising cancer cachexia. In light of their nutritional and anti-inflammatory properties, polyunsaturated fatty acids (PUFAs), and in particular n-3, have been investigated for treating cachexia; however, the results have been contradictory. Since both n-3 and n-6 PUFAs can affect cell functions in several ways, this research investigated the possibility that the effects of both n-3 and n-6 PUFAs could be mediated by their major aldehydic products of lipid peroxidation, 4-hydroxyhexenal (HHE) and 4-hydroxynonenal (HNE), and by their anti-inflammatory properties. An "in vitro" cancer cachexia model, consisting of human lung cancer cells (A427) and murine myoblasts (C2C12), was used. The results showed that: 1) both n-3 and n-6 PUFAs reduced the growth of lung cancer cells without causing cell death, increased lipid peroxidation and Peroxisome Proliferator-Activated Receptor (PPAR)α, and decreased TNFα; 2) culture medium conditioned by A427 cells grown in the absence of PUFAs blocked myosin production and the differentiation of C2C12 muscle cells; conversely, muscle cells grown in culture medium conditioned by the same cells in the presence of PUFAs showed myosin expression and formed myotubes; 3) adding HHE or HNE directly to C2C12 cells maintained in culture medium conditioned by A427 cells in the absence of PUFAs stimulated myosin production and myotube formation; 4) putative consensus sequences for (PPARs) have been found in genes encoding fast isoforms of myosin heavy chain, by a bioinformatics approach. The overall results show, first, the ability of both n-3 and n-6 PUFAs and their lipid peroxidation products to prevent the blocking of myosin expression and myotube formation caused in C2C12 cells by medium conditioned by human lung tumour cells. The C2C12 cell differentiation can be due to direct effect of lipid peroxidation products, as evidenced by treating C2C12 cells with HHE and HNE, and to the decrease of pro-inflammatory TNFα in A427 cell culture medium. The presence of consensus sequences for PPARs in genes encoding the fast isoforms of myosin heavy chain suggests that the effects of PUFAs, HHE, and HNE are PPAR-mediated.

Sosiho‑tang ameliorates cachexia‑related symptoms in mice bearing colon 26 adenocarcinoma by reducing systemic inflammation and muscle loss

Cachexia accompanied by muscle wasting is a key determinant of poor prognosis in cancer patients and cancer‑related death. Previous studies have demonstrated that inflammatory cytokines such as interleukin‑6 (IL‑6), tumor necrosis factor‑α (TNF‑α), IL‑1 and interferon‑γ (IFN‑γ) secreted from host cells and tumor cells participate in skeletal muscle wasting followed by severe loss of body weight. Therefore, blockade of the inflammatory response is thought to be a logical target for pharmacological and nutritional interventions to preserve skeletal muscle mass under cachectic conditions. Sosiho‑tang (SO; Xiaocharihu‑tang in Chinese and Sho‑saiko‑to in Japanese) is an Oriental herbal medicine that has been used to treat chronic hepatic diseases and to control fever. In recent studies, SO inhibited the production of inflammatory cytokines in lipopolysaccharide (LPS)‑stimulated macrophages, prevented thrombus formation and suppressed cancer progression. However, the anti‑cachectic activity of SO in tumor‑bearing mice has not yet been examined. In the present study, we characterized the effect of SO administration on cancer‑induced cachexia in CT‑26‑bearing mice, and elucidated the anti‑cachectic mechanisms. Daily oral administration of SO at doses of 50 and 100 mg/kg to CT‑26‑bearing mice significantly retarded tumor growth and prevented the loss of final body weight, carcass weight, heart weight, gastrocnemius muscle, and epididymal fat, compared with saline‑treated control mice. In addition, serum IL‑6 levels elevated by cancer were decreased by SO administration. In the J774A.1 macrophage cell line, SO efficiently suppressed LPS‑mediated increases in inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO), and procachectic inflammatory cytokine production through inhibition of nuclear factor‑κB (NF‑κB) and p38 activation. In addition, SO attenuated muscle atrophy caused by cancer cells by affecting myoblast proliferation and differentiation, and C2C12 myotube wasting. Taken together, these results suggest that SO is a safe and useful anti‑cachectic therapy for cancer patients with severe weight loss.

Cardiac and skeletal muscles show molecularly distinct responses to cancer cachexia

Cancer cachexia is a systemic, paraneoplastic syndrome seen in patients with advanced cancer. There is growing interest in the altered muscle pathophysiology experienced by cachectic patients. This study reports the microarray analysis of gene expression in cardiac and skeletal muscle in the colon 26 (C26) carcinoma mouse model of cancer cachexia. A total of 268 genes were found to be differentially expressed in cardiac muscle tissue, compared with nontumor-bearing controls. This was fewer than the 1,533 genes that changed in cachectic skeletal muscle. In addition to different numbers of genes changing, different cellular functions were seen to change in each tissue. The cachectic heart showed signs of inflammation, similar to cachectic skeletal muscle, but did not show the upregulation of ubiquitin-dependent protein catabolic processes or downregulation of genes involved in cellular energetics and muscle regeneration that characterizes skeletal muscle cachexia. Quantitative PCR was used to investigate a subset of inflammatory genes in the cardiac and skeletal muscle of independent cachectic samples; this revealed that B4galt1, C1s, Serpina3n, and Vsig4 were significantly upregulated in cardiac tissue, whereas C1s and Serpina3n were significantly upregulated in skeletal tissue. Our skeletal muscle microarray results were also compared with those from three published microarray studies and found to be consistent in terms of the genes differentially expressed and the functional processes affected. Our study highlights that skeletal and cardiac muscles are affected differently in the C26 mouse model of cachexia and that therapeutic strategies cannot assume that both muscle types will show a similar response.

Molecular and neuroendocrine mechanisms of cancer cachexia

Cancer and its morbidities, such as cancer cachexia, constitute a major public health problem. Although cancer cachexia has afflicted humanity for centuries, its underlying multifactorial and complex physiopathology has hindered the understanding of its mechanism. During the last few decades we have witnessed a dramatic increase in the understanding of cancer cachexia pathophysiology. Anorexia and muscle and adipose tissue wasting are the main features of cancer cachexia. These apparently independent symptoms have humoral factors secreted by the tumor as a common cause. Importantly, the hypothalamus has emerged as an organ that senses the peripheral signals emanating from the tumoral environment, and not only elicits anorexia but also contributes to the development of muscle and adipose tissue loss. Herein, we review the roles of factors secreted by the tumor and its effects on the hypothalamus, muscle and adipose tissue, as well as highlighting the key targets that are being exploited for cancer cachexia treatment.

Cancer cachexia update in head and neck cancer: Pathophysiology and treatment

The pathophysiology of cancer cachexia remains complex. A comprehensive literature search was performed up to April 2013 using PubMed, the Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, and the Google search engine. In this review, we focus on the different mediators of impaired anabolism and upregulated catabolism that alter the skeletal muscle homeostasis resulting in the wasting of cancer cachexia. We present recent evidence of targeted treatment modalities from clinical trials along with their potential mechanisms of action. We also report on the most current evidence from randomized clinical trials using multimodal treatments in patients with cancer cachexia, but also the evidence from head and neck cancer-specific trials. A more complete understanding of the pathophysiology of the syndrome may lead to more effective targeted therapies and improved outcomes for patients.

Targeting interleukin-6 in inflammatory autoimmune diseases and cancers

Interleukin-6 (IL-6) is a pleiotropic cytokine with significant functions in the regulation of the immune system. As a potent pro-inflammatory cytokine, IL-6 plays a pivotal role in host defense against pathogens and acute stress. However, increased or deregulated expression of IL-6 significantly contributes to the pathogenesis of various human diseases. Numerous preclinical and clinical studies have revealed the pathological roles of the IL-6 pathway in inflammation, autoimmunity, and cancer. Based on the rich body of studies on biological activities of IL-6 and its pathological roles, therapeutic strategies targeting the IL-6 pathway are in development for cancers, inflammatory and autoimmune diseases. Several anti-IL-6/IL-6 receptor monoclonal antibodies developed for targeted therapy have demonstrated promising results in both preclinical studies and clinical trials. Tocilizumab, an anti-IL-6 receptor antibody, is effective in the treatment of various autoimmune and inflammatory conditions notably rheumatoid arthritis. It is the only IL-6 pathway targeting agent approved by the regulatory agencies for clinical use. Siltuximab, an anti-IL-6 antibody, has been shown to have potential benefits treating various human cancers either as a single agent or in combination with other chemotherapy drugs. Several other anti-IL-6-based therapies are also under clinical development for various diseases. IL-6 antagonism has been shown to be a potential therapy for these disorders refractory to conventional drugs. New strategies, such as combination of IL-6 blockade with inhibition of other signaling pathways, may further improve IL-6-targeted immunotherapy of human diseases.

Novel potential agents for ulcerative colitis by molecular topology: suppression of IL-6 production in Caco-2 and RAW 264.7 cell lines

Ulcerative colitis (UC) is an immune-mediated chronic and relapsing intestinal inflammatory disease. Interleukin (IL)-6, a pro-inflammatory cytokine, plays a key role in the uncontrolled intestinal inflammatory process, which is a main characteristic of UC. In this work, a quantitative structure-activity relationship model based on molecular topology (MT) has been built up to predict the IL-6 mediated anti-UC activity. After an external validation of the model, a virtual screening of the MicroSource Pure Natural Products Collection and Sigma-Aldrich databases was carried out looking for potential new active compounds. From the entire set of compounds labeled as active by the model, four of them, namely alizarin-3-methylimino-N,N-diacetic acid (AMA), Calcein, (+)-dibenzyl-L-tartrate (DLT), and Ro 41-0960, were tested in vitro by determination of IL-6 production in two cell lines (RAW 264.7 and Caco-2). The results demonstrate that three of them were able to significantly reduce IL-6 levels in both cell lines and particularly one, namely Ro 41-0960. These results confirm MT's efficacy as a tool for the selection of compounds potentially active in UC.

Configurational reassignment and improved preparation of the competitive IL-6 receptor antagonist 20R,21R-epoxyresibufogenin-3-formate

20R,21R-Epoxyresibufogenin-3-formate (1) and 20S,21S-epoxyresibufogenin-3-formate (2) were synthesized from commercial resibufogenin (3) using known procedures. The major product (1) was dextrorotatory, as was the major product from the reported synthesis of epoxyresibufogenin-3-formate; however, the literature (+)-compound was assigned the 20S,21S-configuration on the basis of NMR data. We have now unequivocally determined, using single-crystal X-ray structure analyses of the major and minor products of the synthesis and of their derivatives, that the major product from the synthesis was (+)-20R,21R-epoxyresibufogenin-3-formate (1). Our minor synthetic product was determined to have the (-)-20S,21S-configuration (2). The (+)-20R,21R-compound 1 has been found to have high affinity for the IL-6 receptor and to act as an IL-6 antagonist. A greatly improved synthesis of 1 was achieved through oxidation of preformed resibufogenin-3-formate. This has enabled us to prepare, from the very expensive commercial resibufogenin, considerably larger quantities of 1, the only known nonpeptide small-molecule IL-6 antagonist.

Disruption of MEF2C signaling and loss of sarcomeric and mitochondrial integrity in cancer-induced skeletal muscle wasting

Cancer cachexia is a highly debilitating paraneoplastic disease observed in more than 50% of patients with advanced cancers and directly contributes to 20% of cancer deaths. Loss of skeletal muscle is a defining characteristic of patients with cancer cachexia and is associated with poor survival. The present study reveals the involvement of a myogenic transcription factor Myocyte Enhancer Factor (MEF) 2C in cancer-induced skeletal muscle wasting. Increased skeletal muscle mRNA expression of Suppressor of Cytokine Signaling (Socs) 3 and the IL-6 receptor indicative of active IL-6 signaling was seen in skeletal muscle of mice bearing the Colon 26 (C26) carcinoma. Loss of skeletal muscle structural integrity and distorted mitochondria were also observed using electron microscopy. Gene and protein expression of MEF2C was significantly downregulated in skeletal muscle from C26-bearing mice. MEF2C gene targets myozenin and myoglobin as well as myokinase were also altered during cachexia, suggesting dysregulated oxygen transport capacity and ATP regeneration in addition to distorted structural integrity. In addition, reduced expression of calcineurin was observed which suggested a potential pathway of MEF2C dysregulation. Together, these effects may limit sarcomeric contractile ability and also predispose skeletal muscle to structural instability; associated with muscle wasting and fatigue in cachexia.

Reversal of pancreatitis-induced pain by an orally available, small molecule interleukin-6 receptor antagonist

Pancreatic pain resulting from chronic inflammation of the pancreas is often intractable and clinically difficult to manage with available analgesics reflecting the need for more effective therapies. The mechanisms underlying pancreatitis pain are not well understood. Here, the possibility that interleukin-6 (IL-6) may promote pancreatitis pain was investigated with TB-2-081 (3-O-formyl-20R,21-epoxyresibufogenin, EBRF), a small molecule IL-6 receptor antagonist that was semi-synthetically derived from natural sources. The potential activity and mechanism of TB-2-081 were investigated following the induction of persistent pancreatitis using dibutyltin dichloride (DBTC) in rats. TB-2-081 displaces the binding of IL-6 to the human recombinant soluble IL-6 receptor with apparent high affinity and inhibits IL-6 mediated cell growth. Systemic or oral, but not intrathecal, administration of TB-2-081 reversed DBTC-induced abdominal hypersensitivity in a dose- and time-dependent manner. IL-6 levels were significantly up-regulated in the dorsal root ganglia (DRG) of rats with pancreatitis on day 6 after DBTC injection. IL-6-enhanced capsaicin-evoked release of calcitonin gene-related peptide from cultured DRG neurons was blocked by TB-2-081. Our data demonstrate that TB-2-081 acts as a systemically available and orally active small molecule IL-6 receptor antagonist. TB-2-081 effectively reduces pancreatitis-induced pain through peripheral mechanisms that are likely due to (a) increased expression of IL-6 in the DRG and (b) IL-6-mediated sensitization of nociceptive neurons. The activity of TB-2-081 implicates an important role for IL-6 in sustaining pancreatitis pain. Strategies targeting IL-6 actions through small molecule antagonists may offer novel approaches to improve the therapy of chronic pancreatitis and other chronic pain states.

The biological mechanisms of cancer-related skeletal muscle wasting: the role of progressive resistance exercise

Cancer results in perturbations in skeletal muscle protein metabolism leading to muscle wasting. Although severe wasting is seen primarily in persons with advanced malignancies, a number of cancer patients show some degree of wasting at presentation. Although cancer-related skeletal muscle wasting is attributable, in part, to decreased muscle protein synthesis, its primary cause appears to be increased muscle protein degradation. Although several proteolytic systems may be involved, compelling evidence suggests that the major system responsible for skeletal muscle protein degradation in cancer is the ATP-dependent ubiquitin- proteasome system. Other contributing factors include proinflammatory cytokines and the tumor-released proteolysis-inducing factor. Decreased physical activity and decreased nutritional intake may also play a role. Cancer-related skeletal muscle wasting is clinically significant because of its profound effects on functional outcomes and quality of life. Nevertheless, no specific interventions have proved to be effective in preventing or reversing the problem. Interventions such as nutritional supplementation and appetite stimulants are only partially helpful. A nonpharmacologic intervention that may attenuate cancer-related skeletal muscle wasting is progressive resistance exercise training (PRT). PRT is a potent stimulus of growth in muscle mass and strength. PRT may attenuate cancer-related skeletal muscle wasting by downregulating the activity of proinflammatory cytokines and by increasing the phosphorylation of intramuscular amino acid-signaling molecules. This article discusses several cancer-related skeletal muscle wasting mechanisms and proposes how PRT might attenuate muscle wasting by counteracting some of these mechanisms.

Interleukin-6 and its receptor in cancer: implications for translational therapeutics

Interleukin-6 (IL-6) plays a major role in the response to injury or infection and is involved in the immune response, inflammation, and hematopoiesis. Its deregulation impacts numerous disease states, including many types of cancer. Consequently, modulating IL-6 may be an innovative therapeutic strategy in several diseases. A review of relevant published literature regarding IL-6 and its receptor was performed. In addition, a review of the relevance of this cytokine system to human illness, particularly in cancer, was undertaken. IL-6 is a pleiotropic cytokine that is involved in the physiology of virtually every organ system. Aberrant expression of this cytokine has been implicated in diverse human illnesses, most notably inflammatory and autoimmune disorders, coronary artery and neurologic disease, gestational problems, and neoplasms. In cancer, high levels of circulating IL-6 are observed in almost every type of tumor studied and predict a poor outcome. Furthermore, elevated IL-6 levels are associated strongly with several of the striking phenotypic features of cancer. Several molecules have been developed recently that target the biologic function of IL-6. Early results in the clinic suggest that this strategy may have a significant salutary impact on diverse tumors. The field of cytokine research has yielded a deep understanding of the fundamental role of IL-6 and its receptor in health and disease. Therapeutic targeting of IL-6 and its receptor in cancer has strong biologic rationale, and there is preliminary evidence suggesting that targeting of the IL-6 system may be beneficial in the treatment of cancer.

Novel treatments for cancer cachexia

Cancer cachexia is a debilitating and life-threatening syndrome characterised by anorexia, body weight loss, loss of adipose tissue and skeletal muscle, and accounts for > or = 20% of deaths in neoplastic patients. Cancer cachexia significantly impairs quality of life and response to antineoplastic therapies, increasing the morbidity and mortality of cancer patients. Muscle wasting is the most important phenotypic feature of cancer cachexia and the principle cause of function impairment, fatigue and respiratory complications, and is mainly related to a hyperactivation of muscle proteolytic pathways. Existing therapeutic strategies have proven to be only partially effective. In the last decade, the correction of anorexia, the inhibition of catabolic processes and the stimulation of anabolic pathways in muscle has been attempted pharmacologically, giving encouraging results in animal models and through preliminary clinical trials.

3-O-Formyl-20R,21-epoxyresibufogenin suppresses IL-6–type cytokine actions by targeting the glycoprotein 130 subunit: Potential clinical implications

BACKGROUND

The multifunctional inflammatory cytokine IL-6 regulates the acute phase reaction and plays central roles in the pathogenesis of chronic inflammatory disorders.

OBJECTIVES

Two small chemical compounds, 3-O-formyl-20R,21-epoxyresibufogenin (TB-2-081) and 3-O-formyl-20S,21-epoxyresibufogenin (TB-2-082), known isolates from the Chinese toad skin extract drug Ch'an Su, were synthesized and tested on the IL-6-induced hepatic acute-phase reaction.

METHODS

HepG2 cells or rat primary hepatocytes were incubated with the compounds, and the effects on IL-6-induced expression of acute-phase molecules were tested.

RESULTS

TB-2-081, and to a lesser extent TB-2-082, suppressed IL-6-induced alpha1-antichymotrypsin (AACT) mRNA expression in HepG2 cells, whereas TB-2-081 failed to influence the mRNA expression of the TNF-alpha-induced mRNA expression of the methionine adenosyltransferase 2A gene in these cells. TB-2-081 suppressed IL-6-induced mRNA expression of alpha1-acid glycoprotein, alpha2-macroglobulin, and beta-fibrinogen in and secretion of the C-reactive protein by rat primary hepatocytes. TB-2-081 shifted the IL-6 dose-response curve of the AACT mRNA expression right and downward and inhibited IL-6-induced phosphorylation of signal transducer and activator of transcription 3. In addition to IL-6, TB-2-081 inhibited IL-11-stimulated and oncostatin M-stimulated AACT mRNA expression independently of the IL-6 receptor subunit. The soluble glycoprotein 130, but not the soluble IL-6 receptor, antagonized TB-2-081-induced suppression of IL-6-stimulated AACT mRNA expression.

CONCLUSION

TB-2-081 inhibits IL-6-type cytokine action by attenuating the function of the common receptor subunit glycoprotein 130.

CLINICAL IMPLICATIONS

This class of compounds may be beneficial for the treatment of diseases in which excessive circulation/production/action of IL-6-type cytokines play pathologic roles.

Cancer cachexia syndrome in head and neck cancer patients: part I. Diagnosis, impact on quality of life and survival, and treatment

BACKGROUND

Cancer cachexia is a debilitating, wasting condition that affects many cancer patients, including those with head and neck cancer. The overall incidence of cancer cachexia is quite high for some types of cancer, and cachexia will be the main cause of death for more than 20% of all cancer patients. This syndrome uniquely challenges patients with head and neck cancer. This article outlines the diagnosis of cancer cachexia, reviews its impact on patient quality of life (QOL) and survival, and updates the reader on potential therapies that may suppress it.

METHODS

A comprehensive literature search was performed using PubMed of the National Library of Medicine, which includes more than 15 million citations back to the 1950s. The Cochrane Library and Google search engine were used as well.

RESULTS

This syndrome differs significantly from starvation, and thus accurate and timely diagnosis is essential. Nutritional therapy alone is insufficient. Current management strategies include corticosteroids and megesterol acetate, in conjunction with nutritional therapy. Future strategies may include nutraceuticals, omega-3 fatty acids, inflammatory antagonists, and other targeted treatments.

CONCLUSIONS

Because cancer cachexia differs significantly from starvation, nutritional supplementation must be used in conjunction with other anti-cachexia agents to reverse the chronic systemic inflammatory state and the effects of circulating tumor-derived factors seen in cachexia. Careful identification of patients at risk and those suffering from this syndrome will lead to better outcomes and treatments. Ultimately, more research is needed to better treat this devastating condition.

Prevention of cancer cachexia by pyrrolidine dithiocarbamate (PDTC) in colon 26 tumor-bearing mice

BACKGROUND

The precise mechanism of cancer cachexia is not fully elucidated. This study was aimed to assess the effect of pyrrolidine dithiocarbamate (PDTC, an inhibitor of NFkappaB) on interleukin (IL)-6 synthesis and cachexia in colon 26 tumor-bearing mice.

METHODS

Murine colon 26 adenocarcinoma cells were inoculated subcutaneously in male BALB/c mice to induce cachexia. Saline and various doses of PDTC (10, 50, or 100 mg/kg/d) were given intraperitoneally daily from 7 days after tumor inoculation to killing. Body weight, food intake, and tumor volume were monitored daily. Serum and tumor tissue levels of IL-6, serum biochemical indicator, and activity of NFkappaB in tumor tissue were investigated in all mice.

RESULTS

Significant tissue wasting was observed in all tumor-bearing mice. By day 16, carcass weights of untreated tumor-bearing mice were about 71.3% of healthy controls (p < .01), and the weights of gastrocnemius muscle and epididymal fat were lowered by 42.4% and 70.4% (p < .01), respectively. Furthermore, tumor-bearing caused a significant decrease of serum albumin, glucose, and triglyceride (p < .01) and increase of IL-6 (p < .01) in serum and tumor tissues. Administration of PDTC dose dependently inhibited the NFkappaB activation in tumor tissues, inhibited IL-6 synthesis of the tumor cells, and attenuated the wasting of carcass weight, gastrocnemius muscle, and epididymal fat. Tumor growth was inhibited by PDTC with 100 mg/kg (p < .05). No differences of food intake were found between groups (p > .05).

CONCLUSIONS

These results suggest that PDTC, an inhibitor of NFkappaB, can attenuate the development of cachexia in colon 26 tumor-bearing mice through inhibition of IL-6 synthesis regulated by NFkappaB.

Cancer Chemotherapy-Related Symptoms: Evidence to Suggest a Role for Proinflammatory Cytokines

PURPOSE/OBJECTIVES

To provide an overview of the evidence that supports a role for the proinflammatory cytokines interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) in the etiology of cancer chemotherapy-related symptoms.

DATA SOURCES

Electronic nursing, psychology, and medicine databases; online meeting abstracts; and personal experimental observations.

DATA SYNTHESIS

Substantial evidence implicates the proinflammatory cytokines IL-1beta, TNF-alpha, and IL-6 in the etiology of chemotherapy-related anorexia, cachexia, anemia, pain, sleep disturbance, fatigue, and depression.

CONCLUSIONS

Further investigation into the role of these cytokines in the genesis of chemotherapy-related symptoms is warranted. The development of appropriate animal models likely will be key to understanding the relationship among cancer chemotherapy, proinflammatory cytokines, and symptoms.

IMPLICATIONS FOR NURSING

Nurses traditionally have been leaders in symptom management. The symptoms experienced by patients undergoing chemotherapy have a profound negative impact on quality of life and patients' ability to receive prescribed treatments. An understanding of potential mechanisms underlying the physiologic and behavioral consequences of chemotherapy administration will aid nurses in the development of interventions to effectively manage chemotherapy-related symptoms.

Capecitabine improves cancer cachexia and normalizes IL-6 and PTHrP levels in mouse cancer cachexia models

PURPOSE

To clarify the potential of parathyroid hormone-related protein (PTHrP) and interleukin-6 (IL-6) as cachectic factors in a colon 26 model and the effects of capecitabine on cancer cachexia as determined by plasma levels of IL-6 and PTHrP and body weight loss.

METHODS

From two colon 26 sublines-cancer cachectic clone20 and non-cachectic clone5 plasma levels of PTHrP protein and mRNA expression levels in tumor tissues were compared. An IL-6 neutralizing antibody, a PTHrP neutralizing antibody, and capecitabine were administered into mice bearing clone20 and their anticachectic effects evaluated.

RESULTS

The plasma level of PTHrP protein in mice bearing clone20 was higher than that in mice bearing clone5. The expression level of PTHrP mRNA was 49-fold higher in tumor tissues of clone20 than of clone5, according to GeneChip analysis. PTHrP antibody as well as IL-6 antibody suppressed wasting of the body and gastrocnemius and adipose tissue weights. PTHrP antibody suppressed the induction of hypercalcemia but not hypoglycemia or elevation of IL-6, whereas IL-6 antibody suppressed the induction of hypoglycemia but not hypercalcemia or elevation of PTHrP. Capecitabine, a fluorinated pyrimidine anticancer agent, improved body wasting of mice bearing clone20 at a low dose with no reduction of tumor volume. Furthermore, capecitabine lowered the levels of PTHrP and IL-6 in plasma and suppressed hypoglycemia and hypercalcemia in this model. Capecitabine also showed anticachectic effects on cachexia in a cancer model induced by human cervical cancer cell line Y (also known as Yumoto).

CONCLUSIONS

PTHrP and IL-6 were found to be factors in the development of cachexia in a colon 26 cancer model, and capecitabine improved cancer cachexia by suppressing the plasma levels of IL-6 and PTHrP in colon 26 and Y cachectic models.

Cancer-Associated Cachexia and Underlying Biological Mechanisms

Cancer metastases (spread to distant organs from the primary tumor site) signify systemic, progressive, and essentially incurable malignant disease. Anorexia and wasting develop continuously throughout the course of incurable cancer. Overall, in Westernized countries nearly exactly half of current cancer diagnoses end in cure and the other half end in death; thus, cancer-associated cachexia has a high prevalence. The pathophysiology of cancer-associated cachexia has two principal components: a failure of food intake and a systemic hypermetabolism/hypercatabolism syndrome. The superimposed metabolic changes result in a rate of depletion of physiological reserves of energy and protein that is greater than would be expected based on the prevailing level of food intake. These features indicate a need for nutritional support, metabolic management, and a clear appreciation of the context of life-limiting illness.

Dose-dependent cell-based assays in V-shaped microfluidic channels

The capability of lab-on-a-chip technologies in controlling cell transportation, generating concentration gradients, and monitoring cellular responses offers an opportunity to integrate dose-dependent cell-based bioassays on a chip. In this study, we have developed microfluidic modules featured with channel components and sandbag structures for positioning biological cells within the microchip. We have demonstrated that by geometric modulation of the microchannel architectures, it is possible to immobilize individual cells at desired locations with controllable numbers, to generate defined concentration gradients at various channel lengths, and to improve the efficiency and reproducibility in data acquisition. The microfluidic module was used to exercise a series of cell-based assays, including the measurement of kinetics and dynamics of intracellular enzymatic activities, the analysis of cellular response under the stimulation of two chemicals with defined concentration profiles, and the study of laser irradiation effect on cellular uptake of photosensitizers. The results demonstrated the capabilities of the microfluidic module for simultaneously conducting multiple sets of dose-dependent, cell-based bioassays, and for quantitatively comparing responses of individual cells under various stimulations.

Mediators involved in the cancer anorexia-cachexia syndrome: past, present, and future

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia, and anemia 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. 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. Present investigation is devoted to revealing the different signaling pathways, in particular transcriptional factors involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators (both humoral and tumoral) involved in cancer cachexia since they may represent targets for future promising clinical investigations.

The pivotal role of cytokines in muscle wasting during cancer

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia and anemia, is invariably associated with the presence and growth of the tumour and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host leads to an accelerated catabolic state, which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. 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. Present investigation is devoted to unrevealing the different signaling pathways (particulary transcriptional factors) involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators involved in cancer cachexia since they may represent targets for future promising clinical investigations.

A novel peptide specifically binding to interleukin-6 receptor (gp80) inhibits angiogenesis and tumor growth

Experimental and clinical findings support the essential role of interleukin (IL)-6 in the pathogenesis of various human cancers and provide a rationale for targeted therapeutic investigations. A novel peptide, S7, which selectively binds to IL-6 receptor (IL-6R) alpha chain (gp80) and broadly inhibits IL-6-mediated events, was identified using phage display library screening. The synthetic S7 peptide specifically bound to soluble IL-6R as well as cognate human IL-6R alpha, resulting in a dose-dependent blockade of the interaction between IL-6 and IL-6R alpha. S7 peptide prevents IL-6-mediated survival signaling and sensitizes cervical cancer cells to chemotherapeutic compounds in vitro. The in vitro analysis of antiangiogenic activity showed that S7 peptide substantially inhibits IL-6-induced vascular endothelial growth factor-A expression and angiogenesis in different cancer cell lines. Furthermore, S7 peptide was bioavailable in vivo, leading to a significant suppression of IL-6-induced vascular endothelial growth factor-mediated cervical tumor growth in severe combined immunodeficient mice. These observations show the feasibility of targeting IL-6/IL-6R interaction using the small peptide and highlight its potential in the clinical applications.

The pivotal role of cytokines in muscle wasting during cancer

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia and anemia, is invariably associated with the presence and growth of the tumour and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host leads to an accelerated catabolic state, which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. 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. Present investigation is devoted to unrevealing the different signaling pathways (particularly transcriptional factors) involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators involved in cancer cachexia since they may represent targets for future promising clinical investigations.