The role of inflammatory pathways in cancer-associated cachexia and radiation resistance

The relationship of nutritional status with anticancer immunity and its prognostic value for head and neck cancer

Malnutrition has been reported to be associated with reduced survival and deficient anticancer immunity, and undernourishment is a frequent comorbidity in head and neck cancer (HNC) patients. In this study, we evaluated the relationship between nutritional status and immunologic factors, and its prognostic value for HNC. We retrospectively reviewed 212 HNC patients who had undergone a nutrition evaluation based on the Patient-Generated Subjective Global Assessment (PG-SGA) and curative radiotherapy (RT). The role of nutritional status in the prognosis of HNC and its correlation with anticancer immune response was assessed in HNC patients, and in the 4-nitroquinoline 1-oxide (4NQO)-induced tongue tumor animal model. Our data revealed that malnutrition (high PG-SGA scores) was significantly associated with more advanced disease, lower body mass index, lower RT completion rates, and reduced survival. Patients in the group with high PG-SGA scores had a higher neutrophil-to-lymphocyte ratio, higher proportion of myeloid-derived suppressor cells (MDSCs), and elevated IL-6 levels in the peripheral circulation. Patients with increased PG-SGA scores following treatment were more likely to developing locoregional failure. In the 4NQO-induced tumor model, nutritional supplementation decreased the rate of invasive tumor formation and attenuated the immune-suppressive microenvironment. Following ectopic tumor implantation in an immunocompetent host, nutrition supplements decreased tumor growth in association with attenuated MDSC recruitment and lower IL-6 expression. In conclusion, malnutrition by PG-SGA was associated with poor prognosis in HNC patients. Based on the data of HNC patients and the 4NQO-tumor model, adequate nutritional supplementation might improve the prognosis associated with augmented anticancer immunity.

Lenvatinib Synergistically Promotes Radiation Therapy in Hepatocellular Carcinoma by Inhibiting Src/STAT3/NF-κB-Mediated Epithelial-Mesenchymal Transition and Metastasis

PURPOSE

This study suggested that lenvatinib may incapacitate hepatocellular carcinoma (HCC) to radiation treatment by abrogating radiation-induced Src/signal transducer and the activator of transcription 3 signaling (STAT3)/nuclear factor-κB (NF-κB) to escalate radiation-induced extrinsic and intrinsic apoptosis. These findings uncover the role of targeting Src and its arbitrating epithelial-mesenchymal transition (EMT), which could increase the anti-HCC efficacy of radiation therapy (RT). Lenvatinib and sorafenib are multikinase inhibitors used to treat HCC. Lenvatinib is noninferior to sorafenib in the therapeutic response in HCC. However, whether lenvatinib intensifies the anti-HCC efficacy of RT is ambiguous. Several oncogenic kinases and transcription factors, such as Src, STAT3, and NF-κB, enhance the radiosensitivity of cancers. Therefore, we aimed to investigate the roles of the Src/STAT3/NF-κB axis in HCC after RT treatment and assessed whether targeting Src by lenvatinib may enhance the effectiveness of RT.

METHODS AND MATERIALS

Hep3B, Huh7, HepG2, and SK-Hep1 HCC cells and 2 types of animal models were used to identify the efficacy of RT combined with lenvatinib. Cellular toxicity, apoptosis, DNA damage, EMT/metastasis regulation, and treatment efficacy were validated by colony formation, flow cytometry, Western blotting, and in vivo experiments, respectively. Knockdown of Src by siRNA was also used to validate the role of Src in RT treatment.

RESULTS

Silencing Src reduced STAT3/NF-κB signaling and sensitized HCC to radiation. Lenvatinib reversed radiation-elicited Src/STAT3/NF-κB signaling while enhancing the anti-HCC efficacy of radiation. Both lenvatinib and siSrc promoted the radiation effect of cell proliferation on suppression, inhibition of the invasion ability, and induction of apoptosis in HCC. Lenvatinib also alleviated radiation-triggered oncogenic and EMT-related protein expression.

CONCLUSIONS

Our findings uncovered the role of the Src/STAT3/NF-κB regulatory axis in response to radiation-induced toxicity and confirmed Src as the key regulatory molecule for radiosensitization of HCC evoked by lenvatinib.

The Role of Skeletal Muscle Mitochondria in Colorectal Cancer Related Cachexia: Friends or Foes?

Up to 60% of colorectal cancer (CRC) patients develop cachexia. The presence of CRC related cachexia is associated with more adverse events during systemic therapy, leading to a high mortality rate. The main manifestation in CRC related cachexia is the loss of skeletal muscle mass, resulting from an imbalance between skeletal muscle protein synthesis and protein degradation. In CRC related cachexia, systemic inflammation, oxidative stress, and proteolytic systems lead to mitochondrial dysfunction, resulting in an imbalanced skeletal muscle metabolism. Mitochondria fulfill an important function in muscle maintenance. Thus, preservation of the skeletal muscle mitochondrial homeostasis may contribute to prevent the loss of muscle mass. However, it remains elusive whether mitochondria play a benign or malignant role in the development of cancer cachexia. This review summarizes current (mostly preclinical) evidence about the role of skeletal muscle mitochondria in the development of CRC related cachexia. Future human research is necessary to determine the physiological role of skeletal muscle mitochondria in the development of human CRC related cachexia.

Molecular imprinting as a tool for determining molecular markers: a lung cancer case

Determining which cancer patients will be sensitive to a given therapy is essential for personalised medicine. Thus, it is important to develop new tools that will allow us to stratify patients according to their predicted response to treatment. The aim of work presented here was to use molecular imprinting for determining the sensitivity of lung cancer cell lines to ionising radiation based on cell surface proteomic differences. Molecularly imprinted polymer nanoparticles (nanoMIPs) were formed in the presence of whole cells. Following trypsinolysis, protein epitopes protected by complexing with MIPs were eluted from the nanoparticles and analysed by LC-MS/MS. The analysis identified two membrane proteins, neutral amino acid transporter B (0) and 4F2 cell-surface antigen heavy chain, the abundance of which in the lung cancer cells could indicate resistance of these cells to radiotherapy. This proof-of-principle experiments shows that this technology can be used in the discovery of new biomarkers and in development of novel diagnostic and therapeutic tools for a personalised medicine approach to treating cancer.

A first use of molecular imprinting for characterisation of surfaceome of the lung cancer cells and discovery of the molecular markers for radiosensitivity: towards development of an effective tool for cancer therapy and personalised medicine.

The Impact of Weight Loss during Chemoradiotherapy for Unresectable Esophageal Cancer: Real-World Results

Weight loss is a common phenomenon presented in unresectable esophageal cancer (EC) patients during their definitive chemoradiotherapy (dCRT) treatment course. This study explored the prognostic value of weight changes during dCRT in unresectable EC patients. From 2009 to 2017, 69 cT4b thoracic EC patients undergoing complete curative dCRT without baseline malnutrition were included. Clinical factors were analyzed via the Cox proportional hazards model and survival was analyzed by the Kaplan−Meier method. During dCRT, the median weight loss percentage was 5.51% (IQR = 2.77−8.85%), and the lowest body weight was reached at 35 days (IQR = 23−43 days). Median OS of these patients was 13.5 months. Both univariate and multivariate analysis demonstrated that weight loss ≤ 4% during dCRT was significantly associated with superior OS with a hazard ratio of 2.61 (95% CI: 1.40−4.85, p = 0.002). The median OS for patients with weight loss ≤ 4% and >4% during dCRT was 59.6 months and 9.7 months, respectively (p = 0.001). Our study demonstrated that weight loss ≤ 4% during dCRT course is a favorable prognostic factor for cT4b EC patients. This index could serve as a nutrition support reference for unresectable EC patients receiving dCRT in the future.

Decreased miR-497-5p Suppresses IL-6 Induced Atrophy in Muscle Cells

Interleukin-6 (IL-6) is a pro-inflammatory cytokine associated with skeletal muscle wasting in cancer cachexia. The control of gene expression by microRNAs (miRNAs) in muscle wasting involves the regulation of thousands of target transcripts. However, the miRNA-target networks associated with IL6-induced muscle atrophy remain to be characterized. Here, we show that IL-6 promotes the atrophy of C2C12 myotubes and changes the expression of 20 miRNAs (5 up-regulated and 15 down-regulated). Gene Ontology analysis of predicted miRNAs targets revealed post-transcriptional regulation of genes involved in cell differentiation, apoptosis, migration, and catabolic processes. Next, we performed a meta-analysis of miRNA-published data that identified miR-497-5p, a down-regulated miRNAs induced by IL-6, also down-regulated in other muscle-wasting conditions. We used miR-497-5p mimics and inhibitors to explore the function of miR-497-5p in C2C12 myoblasts and myotubes. We found that miR-497-5p can regulate the expression of the cell cycle genes CcnD2 and CcnE1 without affecting the rate of myoblast cellular proliferation. Notably, miR-497-5p mimics induced myotube atrophy and reduced Insr expression. Treatment with miR-497-5p inhibitors did not change the diameter of the myotubes but increased the expression of its target genes Insr and Igf1r. These genes are known to regulate skeletal muscle regeneration and hypertrophy via insulin-like growth factor pathway and were up-regulated in cachectic muscle samples. Our miRNA-regulated network analysis revealed a potential role for miR-497-5p during IL6-induced muscle cell atrophy and suggests that miR-497-5p is likely involved in a compensatory mechanism of muscle atrophy in response to IL-6.

Cachexia and bladder cancer: clinical impact and management

PURPOSE OF REVIEW

The purpose of this review is to describe the causes, management, and clinical outcomes associated with cachexia and related components including sarcopenia, among patients with bladder cancer (BCa).

RECENT FINDINGS

Cachexia in patients with BCa is associated with poorer outcomes after radical cystectomy (RC), radiation, and chemotherapy. Nutritional supplements and novel pharmaceutical agents including magnolol, flucoidan and Anamorelin are currently undergoing investigation for their potential use in BCa patients with cachexia.

SUMMARY

Cachexia is a hypercatabolic state thought to be caused by an immune-regulated release of cytokines and disruptions of molecular pathways within the tumor microenvironment and systemically. Nutritional deficiencies in patients with BCa also contribute to cachexia and sarcopenia. Patients with BCa -related cachexia and sarcopenia experience worse survival and therapeutic outcomes after RC, chemotherapy, and radiation therapy. Patients with cachexia also experience more postoperative complications after RC. The management of cachexia in patients with BCa remains challenging and requires timely identification, and multidisciplinary management including nutritional supplementation, physical therapy, palliative care, and pharmacological agents. Clinical trials and human studies are still required to determine which pharmacological agents are optimal for BCa cachexia.

L-carnitine ameliorates the muscle wasting of cancer cachexia through the AKT/FOXO3a/MaFbx axis

Background

Recent studies suggest potential benefits of applying L-carnitine in the treatment of cancer cachexia, but the precise mechanisms underlying these benefits remain unknown. This study was conducted to determine the mechanism by which L-carnitine reduces cancer cachexia.

Methods

C2C12 cells were differentiated into myotubes by growing them in DMEM for 24 h (hrs) and then changing the media to DMEM supplemented with 2% horse serum. Differentiated myotubes were treated for 2 h with TNF-α to establish a muscle atrophy cell model. After treated with L-carnitine, protein expression of MuRF1, MaFbx, FOXO3, p-FOXO3a, Akt, p-Akt, p70S6K and p-p70S6K was determined by Western blotting. Then siRNA-Akt was used to determine that L-carnitine ameliorated cancer cachexia via the Akt/FOXO3/MaFbx. In vivo, the cancer cachexia model was established by subcutaneously transplanting CT26 cells into the left flanks of the BALB/c nude mice. After treated with L-carnitine, serum levels of IL-1, IL-6 and TNF-α, and the skeletal muscle content of MuRF1, MaFbx, FOXO3, p-FOXO3a, Akt, p-Akt, p70S6K and p-p70S6K were measured.

Results

L-carnitine increased the gastrocnemius muscle (GM) weight in the CT26-bearing cachexia mouse model and the cross-sectional fiber area of the GM and myotube diameters of C2C12 cells treated with TNF-α. Additionally, L-carnitine reduced the protein expression of MuRF1, MaFbx and FOXO3a, and increased the p-FOXO3a level in vivo and in vitro. Inhibition of Akt, upstream of FOXO3a, reversed the effects of L-carnitine on the FOXO3a/MaFbx pathway and myotube diameters, without affecting FOXO3a/MuRF-1. In addition to regulating the ubiquitination of muscle proteins, L-carnitine also increased the levels of p-p70S6K and p70S6K, which are involved in protein synthesis. Akt inhibition did not reverse the effects of L-carnitine on p70S6K and p-p70S6K. Hence, L-carnitine ameliorated cancer cachexia via the Akt/FOXO3/MaFbx and p70S6K pathways. Moreover, L-carnitine reduced the serum levels of IL-1 and IL-6, factors known to induce cancer cachexia. However, there were minimal effects on TNF-α, another inducer of cachexia, in the in vivo model.

Conclusion

These results revealed a novel mechanism by which L-carnitine protects muscle cells and reduces inflammation related to cancer cachexia.

Role of Nutritional Status in the Treatment Outcome for Esophageal Squamous Cell Carcinoma

Undernourishment is reported to impair treatment response, further leading to poor prognosis for cancer patients. We aimed to investigate the role of nutritional status on the prognosis of squamous cell carcinoma (SCC) of the esophagus, and its correlation with anticancer immune responsiveness. We retrospectively reviewed 340 esophageal-SCC patients who completed curative treatment and received a nutrition evaluation by the Patient-Generated Subjective Global Assessment (PGSGA) score at the beginning and completion of neoadjuvant treatment at our hospital. The correlation between the nutritional status and various clinicopathological parameters and prognosis were examined. In addition, the role of nutritional status in the regulation of the anticancer immune response was also assessed in cancer patients and in a 4-nitroquinoline 1-oxide (4NQO)-induced esophageal tumor model. Our data revealed that malnutrition (patients with a high PGSGA score) was associated with advanced stage and reduced survival rate. Patients in the group with a high PGSGA score were correlated with the higher neutrophil-to-lymphocyte ratio, higher proportion of myeloid-derived-suppressor cells (MDSC) and increased IL-6 level. Furthermore, surgical resection brought the survival benefit to patients in the low PGSGA group, but not for the malnourished patients after neoadjuvant treatment. Using a 4NQO-induced tumor model, we found that nutrition supplementation decreased the rate of invasive tumor formation and attenuated the immune-suppressive microenvironment. In conclusion, malnutrition was associated with poor prognosis in esophageal-SCC patients. Nutritional status evaluated by PGSGA may be useful to guide treatment decisions in clinical practice. Nutritional supplementation is suggested to improve prognosis, and it might be related to augmented anticancer immune response.

Association of handgrip strength and endurance with body composition in head and neck cancer patients

Introduction:

Assessment of skeletal muscle function (SMF) is of clinical relevance in the prediction of treatment outcome and to decide on optimal management of head & neck cancer (HNC) patients. Handgrip strength (HGS) & handgrip endurance (HGE) are considered as surrogate marker for whole-body skeletal muscle function. Further, SMF depends substantially on the body composition (BC). Hence in this study, we compared BC, HGS and HGE between HNC patients and healthy controls and also analysed the association of HGS, HGE with body composition in HNC patients.

Methods:

A cross-sectional study, conducted in 44 subjects in the age between 18 to 60 years. Twenty-two were histologically proven HNC patients prior to cancer-specific treatment and twenty-two age and gender-matched healthy volunteers. The parameters recorded were Height, weight, waist circumference, hip circumference, HGS, HGE and BC. Hand-held dynamometer was used to measure HGS and HGE measured using a stopwatch. BC was estimated by whole-body bioelectrical Impedance analysis method using Bodystat Quad scan 4000 device.

Result:

Comparison of data between HNC patient & healthy control was done by Student's t test. HGS, HGE, lean body mass (LBM), fat-free mass index (FFMI), Phase angle (PA), body cell mass (BCM) and body cell mass index (BCMI) were found to be reduced significantly in HNC patients when compared to healthy subjects. Further, Pearson correlation analysis revealed a significant positive correlation of HGS & HGE with LBM, FFMI, PA, BCM & BCMI, whereas body fat mass index showed a negative correlation with HGS & HGE in HNC patients.

Conclusion:

Our findings revealed, a significant reduction in HGS, HGE in patient with HNC which denotes decreased skeletal muscle function and it is linearly associated with low muscle mass, body cell mass and phase angle.

Usefulness of Honey as an Adjunct in the Radiation Treatment for Head and Neck Cancer: Emphasis on Pharmacological and Mechanism/s of Actions

BACKGROUND

In the treatment of head and neck cancer (HNC), ionizing radiation is an important modality in achieving curative objectives. However, the effective use of radiation is compromised by the side effects resulting from the damage to the adjacent normal tissue. Preclinical studies carried out in the recent past have shown that the age old dietary agent honey, which also possess myriad medicinal use is beneficial in mitigating diverse radiation-induced side effects like mucositis, xerostomia, fatigue, weight loss and to promote healing of refractory wounds.

OBJECTIVE

The objective of this memoir is to review the beneficial effects of honey in mitigating radiation-induced side effects in HNC and to emphasize on the underlying mechanism of action for the beneficial effects Methods: Two authors searched Google Scholar, PubMed, Embase, and the Cochrane Library for publications up to December 2019 to assess the ability of honey in reducing the severity of radiation-induced ill effects in the treatment of HNC. Subsequently, the adjunct pharmacological effects and mechanism/s responsible were also searched for and appropriately used to substantiate the underlying mechanism/s of action for the beneficial effects.

RESULTS

The existing data is suggestive that honey is beneficial in mitigating the radiation-induced mucositis, xerostomia, healing of recalcitrant wounds in radiation exposed regions and multiple pathways mediate the beneficial effects especially, free radical scavenging, antioxidant, wound healing, anticancer, analgesic, anti-inflammatory, anabolic, anti-fatigue and anti-anaemic effects that add additional value to the use of honey as an adjunct in cancer therapy.

CONCLUSION

For the first time this review addresses the underlying pharmacological effects related to the beneficial effects of honey in radiation-induced damage, and attempts at emphasizes the lacunae that need further studies for optimizing the use of honey as an adjunct in radiotherapy of HNC. The authors suggest that future studies should be directed at understanding the detail molecular mechanisms responsible for the beneficial effects using validated cell culture and animal models of study. Large multi centric clinical trials with standardised honey is also needed to understand the clinical use of honey.

Development and progression of cancer cachexia: Perspectives from bench to bedside

Cancer cachexia (CC) is a devastating syndrome characterized by weight loss, reduced fat mass and muscle mass that affects approximately 80% of cancer patients and is responsible for 22%-30% of cancer-associated deaths. Understanding underlying mechanisms for the development of CC are crucial to advance therapies to treat CC and improve cancer outcomes. CC is a multi-organ syndrome that results in extensive skeletal muscle and adipose tissue wasting; however, CC can impair other organs such as the liver, heart, brain, and bone as well. A considerable amount of CC research focuses on changes that occur within the muscle, but cancer-related impairments in other organ systems are understudied. Furthermore, metabolic changes in organ systems other than muscle may contribute to CC. Therefore, the purpose of this review is to address degenerative mechanisms which occur during CC from a whole-body perspective. Outlining the information known about metabolic changes that occur in response to cancer is necessary to develop and enhance therapies to treat CC. As much of the current evidences in CC are from pre-clinical models we should note the majority of the data reviewed here are from preclinical models.

Polymorphism of TNFRSF1 A may act as a predictor of severe radiation-induced oral mucositis and a prognosis factor in patients with head and neck cancer

OBJECTIVE

The aim of this study was to evaluate the relationship between single nucleotide polymorphism (SNP) (-135 T>C) of TNFRSF1 A and the frequency of occurrence and severity of oral mucositis (OM) in patients with head and neck cancer (HNC) treated with radiotherapy (RT).

STUDY DESIGN

This retrospective, cohort study included 60 patients with HNC treated with intensity-modulated radiation therapy (IMRT). TNFRSF1 A SNP analysis (-135 T>C) was performed by using molecular probes (TaqMan, ThermoFisher Scientific, Waltham, MA) in DNA isolated from peripheral blood (QIAamp DNA MiniKit; Qiagen, Germantown, MD).

RESULTS

CC genotype was related to 4.5-fold higher risk of grade 2 OM after the second week of RT. Similarly, CC carriers had a significantly higher risk of severe (grade 3) OM after the fourth (6-fold) and fifth (7.5-fold) weeks of RT. The CC genotype of the TNFRSF1 A gene was significantly correlated with a higher risk of shorter overall survival (OS) (> 37 months follow-up period; hazard ratio [HR] = 2.78).

CONCLUSIONS

SNP (-135 T>C) of the TNFRSF1 A gene may act as a predictor of OM occurrence in patients with HNC treated with IMRT. The studied SNP may also serve as a prognostic factor in such cases.

The evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates

The recombination activating gene (RAG or RAG1/RAG2 complex)-mediated adaptive immune system is a hallmark of jawed vertebrates. It has been reported that RAG originated in invertebrates. However, whether RAG further evolved once it arose in jawed vertebrates remains largely unknown. Here, we found that zebrafish RAG (zRAG) had a lower activity than mouse RAG (mRAG). Intriguingly, the attenuated stability of zebrafish RAG2 (zRAG2), but not zebrafish RAG1, caused the reduced V(D)J recombination efficiency compared to mRAG at 37 °C which are the body temperature of most endotherms except birds. Importantly, the lower temperature 28 °C, which is the best temperature for zebrafish growth, made the recombination efficiency of zRAG similar to that of mRAG by improving the stability of zRAG2. Consistent with the prementioned observation, the V(D)J recombination of Rag2^KI/KI mice, which zRAG2 was substituted for mRAG2, was also severely impaired. Unexpectedly, Rag2^KI/KI mice developed cachexia syndromes accompanied by premature death. Taken together, our findings illustrate that the evolution of zebrafish RAG2 protein is required for adapting to the elevated body temperature of the higher endothermic vertebrates.

Combination Therapy With Charged Particles and Molecular Targeting: A Promising Avenue to Overcome Radioresistance

Radiotherapy plays a central role in the treatment of cancer patients. Over the past decades, remarkable technological progress has been made in the field of conventional radiotherapy. In addition, the use of charged particles (e.g., protons and carbon ions) makes it possible to further improve dose deposition to the tumor, while sparing the surrounding healthy tissues. Despite these improvements, radioresistance and tumor recurrence are still observed. Although the mechanisms underlying resistance to conventional radiotherapy are well-studied, scientific evidence on the impact of charged particle therapy on cancer cell radioresistance is restricted. The purpose of this review is to discuss the potential role that charged particles could play to overcome radioresistance. This review will focus on hypoxia, cancer stem cells, and specific signaling pathways of EGFR, NFκB, and Hedgehog as well as DNA damage signaling involving PARP, as mechanisms of radioresistance for which pharmacological targets have been identified. Finally, new lines of future research will be proposed, with a focus on novel molecular inhibitors that could be used in combination with charged particle therapy as a novel treatment option for radioresistant tumors.

Systemic Inflammatory Reaction in Patients With Head and Neck Cancer-An Explorative Study

Aim: To assess the longitudinal pattern of pro-inflammatory cytokines and growth factors in serum up to 1 year following treatment for head and neck cancer. Materials and Methods: Patients with newly diagnosed, curable head and neck cancer were included (n = 30). The most common subsite was oropharynx (n = 13) followed by oral cavity (n = 9). Blood was drawn from all patients at regular intervals (before treatment, 7 weeks after the start of the treatment, and at 3 months and 1 year after termination of treatment) and analyzed for cytokines (Il-1β, Il-2, Il-4, Il-5, Il-6, Il-8, Il-10, GM-CSF, TNF-α, and IFN-γ) and growth factors (G-CSF, FGF-2, EGF, and VEGF). Results: The time point of the peak level of pro-inflammatory cytokines was 7 weeks after start of treatment which corresponded for the majority of patients with termination of radiotherapy or chemoradiotherapy. Patients undergoing chemoradiotherapy exhibited a significant increase of IL-1β, IL-6, and IL-10 at 7 weeks as compared to pre-treatment levels. At 1 year after termination of treatment four patients experienced recurrence of disease while 26 patients were considered disease-free. The patients with recurrence had significantly higher levels of IL-1β, IL-6, IL-8, and IL-10 at 7 weeks after the start of treatment than patients without recurrence. Correlated with T stadium patients with T3-T4 had higher levels of IL-1β and IL-8 than patients with T1-T2 7 weeks after the start of treatment. Conclusions: The observed immune response in this explorative study demonstrates that chemoradiotherapy may induce not only a local treatment effect on the immune system but also effects far outside the irradiated field. The result of the study indicates that analysis of a pro-inflammatory panel of cytokines in serum at 7 weeks after the start of treatment could be of prognostic value in patients with head and neck cancer. Further study of a larger cohort could help identify patients at larger risk for recurrent disease with measurements of pro-inflammatory cytokines under and after treatment.

Nutritional issues in patients with cancer

Cancer is a catabolic inflammatory disease that causes patients to often experience weight loss, or even cachexia in severe cases. Undernourishment in patients with cancer impairs the quality of life and therapeutic response, further leading to poor prognosis. Active and frequent nutritional screening and assessment using valid tools are important for fast and appropriate nutritional intervention. Additionally, a suitable individualized nutritional intervention strategy should be established based on the nutritional assessment result. In general, nutritional intervention begins with nutritional counseling of patients diagnosed with cancer, and a well-planned nutritional counseling improves the treatment adherence and nutritional status. When planning nutritional supplementation for cancer patients, specific nutrients, including amino acids and fatty acids, should be considered. However, there has been no consistent result showing that any particular nutrient significantly improves the prognosis of cancer patients. Hence, continuous attention from clinical physicians is needed to plan nutritional improvement in patients with cancer.

Macrophage Depletion in Elderly Mice Improves Response to Tumor Immunotherapy, Increases Anti-tumor T Cell Activity and Reduces Treatment-Induced Cachexia

Most cancers emerge in the elderly, including lung cancer and mesothelioma, yet the elderly remain an underrepresented population in pre-clinical cancer studies and clinical trials. The immune system plays a critical role in the effectiveness of many anti-cancer therapies in young hosts via tumor-specific T cells. However, immunosuppressive macrophages can constitute up to 50% of the tumor burden and impair anti-tumor T cell activity. Altered macrophage phenotype and function during aging may further impact anti-tumor T cell responses. Yet, the impact of macrophages on anti-tumor T cell responses and immunotherapy in the elderly is unknown. Therefore, we examined macrophages and their interaction with T cells in young (3 months) and elderly (20-24 months) AE17 mesothelioma-bearing female C57BL/6J mice during tumor growth. Mesothelioma tumors grew faster in elderly compared with young mice, and this corresponded with an increase in tumor-associated macrophages. During healthy aging, macrophages increase in bone marrow and spleens suggesting that these sites have an increased potential to supply cancer-promoting macrophages. Interestingly, in tumor-bearing mice, bone marrow macrophages increased proliferation whilst splenic macrophages had reduced proliferation in elderly compared with young mice, and macrophage depletion using the F4/80 antibody slowed tumor growth in young and elderly mice. We also examined responses to treatment with intra-tumoral IL-2/anti-CD40 antibody immunotherapy and found it was less effective in elderly (38% tumor regression) compared to young mice (90% regression). Tumor-bearing elderly mice decreased in vivo anti-tumor cytotoxic T cell activity in tumor draining lymph nodes and spleens. Depletion of macrophages using F4/80 antibody in elderly, but not young mice, improved IL-2/anti-CD40 immunotherapy up to 78% tumor regression. Macrophage depletion also increased in vivo anti-tumor T cell activity in elderly, but not young mice. All the tumor-bearing elderly (but not young) mice had decreased body weight (i.e., exhibited cachexia), which was greatly exacerbated by immunotherapy; whereas macrophage depletion prevented this immunotherapy-induced cachexia. These studies strongly indicate that age-related changes in macrophages play a key role in driving cancer cachexia in the elderly, particularly during immunotherapy, and sabotage elderly anti-tumor immune responses.

Myokines as Possible Therapeutic Targets in Cancer Cachexia

Cachexia is an extremely serious syndrome which occurs in most patients with different cancers, and it is characterized by systemic inflammation, a negative protein and energy balance, and involuntary loss of body mass. This syndrome has a dramatic impact on the patient's quality of life, and it is also associated with a low response to chemotherapy leading to a decrease in survival. Despite this, cachexia is still underestimated and often untreated. New research is needed in this area to understand this complex phenomenon and ultimately find treatment methods and therapeutic targets. The skeletal muscle can act as an endocrine organ. Signaling between muscles and other systems is done through myokines, cytokines, and proteins produced and released by myocytes. In this review, we would like to draw attention to some of the most important myokines that could have potential as biomarkers and therapeutic targets: myostatin, irisin, myonectin, decorin, fibroblast growth factor 21, interleukin-6, interleukin-8, and interleukin-15.

Prognostic value of inflammation-based prognostic index in patients with nasopharyngeal carcinoma: a propensity score matching study

Purpose

The aim of this article is to investigate the significance of pretreatment prognostic nutritional index (PNI), systemic immune-inflammation index (SII), and their combination in nasopharyngeal carcinoma (NPC) patients receiving intensity-modulated radiotherapy (IMRT).

Materials and methods

A total of 585 patients were included. PNI and SII were calculated within 2 weeks prior to treatment. The optimal cutoff points were determined based on receiver operating characteristics curve analysis. The correlation between variables was analyzed. Kaplan–Meier method and Cox proportional hazards model were performed to evaluate the impact of both indices on overall survival (OS), progression-free survival (PFS) and distant metastasis-free survival (DMFS). Further propensity score matching (PSM) was carried out to minimize the effects of confounders.

Results

The optimal cutoff point of 53.0 for PNI and 527.20 for SII were selected. Pearson correlation coefficient showed an inverse correlation between PNI and SII (r = −0.232, P < 0.001). Multivariate analysis demonstrated that pretreatment PNI was an independent prognostic factor for OS (P = 0.047) and DMFS (P = 0.002) while pretreatment SII was an independent prognostic factor for OS (P = 0.003), PFS (P = 0.002), and DMFS (P = 0.002). After PSM, both parameters remained as independent prognosticators of survival. Additional prognostic value was observed in the combined use of PNI and SII.

Conclusion

Pretreatment PNI and SII are promising indicators of survival in NPC patients undergoing IMRT. They can be utilized to refine current TNM staging system in predicting prognosis and developing an individualized treatment in these patients.

Skeletal muscle-gut axis: emerging mechanisms of sarcopenia for intestinal and extra intestinal diseases

In recent years, there has been an increasing interest on muscle wasting, considering the reduction of quality of life and the increase of morbidity and mortality associated. Sarcopenia and cachexia represent two conditions of reduction of muscle mass, sharing several elements involved in their pathogenesis, such as systemic inflammation, impaired muscle protein synthesis, increased muscle apoptosis, mitochondrial dysfunction in skeletal muscle tissue and insulin resistance. These features often characterize cancer, inactivity or denervation, but also inflammatory diseases, such as chronic obstructive pulmonary disease, renal failure, cardiac failure, rheumatoid arthritis, inflammatory bowel disease and aging in general. The gastrointestinal tract and gut microbiota are thought to be deeply associated with muscle function and metabolism, although the exact mechanisms that link gut with skeletal muscle are still not well known. This review summarized the potential pathways linking gut with muscle, in particular in conditions as sarcopenia and cachexia. The main emerging pathways implicated in the skeletal muscle-gut axis are: the myostatin/activin signaling pathway, the IGF1/PI3K/AKT/mTOR signaling pathway, which results suppressed, the NF-kB signaling pathway and the FOXO signaling pathway. Further researches in this field are necessary to better explain the linkage between gut microbiota and muscle wasting and the possible emerging therapies associated.

Implications of weight loss for cancer patients receiving radiotherapy

PURPOSE OF REVIEW

Cancer-associated weight loss is a common comorbid condition best described among patients with advanced malignancy receiving systemic therapy, but its relationship to patients undergoing radiation treatment is less well described. We review the interaction between cancer-associated weight loss and radiation treatment as well as its prognostic significance.

RECENT FINDINGS

Multiple studies demonstrate a consistent detrimental effect of cancer-associated weight loss either existing prior to treatment or developing during radiotherapy. Emerging data suggest cancer-associated weight loss independently contributes to an aggressive malignant phenotype rather than simply reflecting a consequence of disease. Novel therapies are urgently needed to address the unmet burden of cancer-associated weight loss.

SUMMARY

Consideration of cancer-associated weight loss is important among patients receiving radiotherapy. Further study will further characterize the relationship and identify targetable biologic mechanisms of cancer cachexia.

Syngeneic B16F10 Melanoma Causes Cachexia and Impaired Skeletal Muscle Strength and Locomotor Activity in Mice

Muscle wasting has been emerging as one of the principal components of cancer cachexia, leading to progressive impairment of work capacity. Despite early stages melanomas rarely promotes weight loss, the appearance of metastatic and/or solid tumor melanoma can leads to cachexia development. Here, we investigated the B16F10 tumor-induced cachexia and its contribution to muscle strength and locomotor-like activity impairment. C57BL/6 mice were subcutaneously injected with 5 × 10⁴ B16F10 melanoma cells or PBS as a Sham negative control. Tumor growth was monitored during a period of 28 days. Compared to Sham mice, tumor group depicts a loss of skeletal muscle, as well as significantly reduced muscle grip strength and epididymal fat mass. This data are in agreement with mild to severe catabolic host response promoted by elevated serum tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and lactate dehydrogenase (LDH) activity. Tumor implantation has also compromised general locomotor activity and decreased exploratory behavior. Likewise, muscle loss, and elevated inflammatory interleukin were associated to muscle strength loss and locomotor activity impairment. In conclusion, our data demonstrated that subcutaneous B16F10 melanoma tumor-driven catabolic state in response to a pro-inflammatory environment that is associated with impaired skeletal muscle strength and decreased locomotor activity in tumor-bearing mice.

The effects of nonsteroidal anti-inflammatory drugs in the incident and recurrent risk of hepatocellular carcinoma: a meta-analysis

Background

Recent studies have showed that nonsteroidal anti-inflammatory drugs (NSAIDs) could reduce the risk of several types of cancer. However, epidemiological evidence of the association between NSAIDs intake and the risk of hepatocellular carcinoma (HCC) remains controversial.

Methods

To assess the preventive benefit of NSAIDs in HCC, we simultaneously searched the databases of PubMed, EmBase, Web of Science, and Scopus and screened eligible publications.

Results

A total of twelve articles (published from 2000 to 2017) from five countries were identified by retrieval. We observed a significantly lower risk of HCC incidence among users of NSAIDs than among those who did not use NSAIDs (pooled hazard ratio [HR] value =0.81, 95% confidence interval [CI]: 0.69–0.94). No evidence of publication bias was observed (Begg’s test, P=0.755; Egger’s test, P=0.564). However, when stratified according to the categories of NSAIDs, users of non-aspirin NSAIDs (HR =0.81, 95% CI: 0.70–0.94), but not aspirin (HR =0.77, 95% CI: 0.58–1.02), showed a statistically significant reduced HCC incidence. We also found that NSAIDs use significantly reduced the recurrent risk of HCC, with a HR value of 0.79 (95% CI: 0.75–0.84), whereas there was no statistically significant association between NSAIDs use and HCC mortality, with a HR value 0.65 (95% CI: 0.40–1.06).

Conclusion

Taken together, our meta-analysis demonstrates that NSAIDs significantly reduce the incident and recurrent risk of HCC.

The immunosuppressive cytokine interleukin-4 increases the clonogenic potential of prostate stem-like cells by activation of STAT6 signalling

Interleukin-4 plays a critical role in the regulation of immune responses and has been detected at high levels in the tumour microenvironment of cancer patients, where concentrations correlate with the grade of malignancy. In prostate cancer, interleukin-4 has been associated with activation of the androgen receptor, increased proliferation and activation of survival pathways such as Akt and NF-κB. However, its role in therapy resistance has not yet been determined. Here we investigate the influence of interleukin-4 on primary epithelial cells from prostate cancer patients. Our data demonstrate an increase in the clonogenic potential of these cells when cultured in the presence of interleukin-4. In addition, a Phospho-Kinase Array revealed that in contrast to previously published work, signal transducer and activator of transcription6 (STAT6) is the only signalling molecule activated after interleukin-4 treatment. Using the STAT6-specific inhibitor AS1517499 we could confirm the role of STAT6 in increasing colony-forming frequency. However, clonogenic recovery assays revealed that interleukin-4 does not rescue the effects of either irradiation or docetaxel treatment. We therefore propose that although the interleukin-4/STAT6 axis does not appear to be involved in therapy resistance, it does play a crucial role in the colony-forming abilities of the basal cell population in prostate cancer. IL-4 may therefore contribute to disease relapse by providing a niche that is favourable for the clonogenic growth of prostate cancer stem cells.

Nephroprotective effect of β-sitosterol on N-diethylnitrosamine initiated and ferric nitrilotriacetate promoted acute nephrotoxicity in Wistar rats

BACKGROUND

The most abundant plant sterol β-sitosterol is widely used for treating heart diseases and chronic inflammatory conditions. The objective of the current study was to evaluate the nephroprotective effect of β-sitosterol against nephrotoxicants which were studied using renal function markers, antioxidant and lipid peroxidation status, and inflammatory markers.

METHODS

Male albino Wistar rats were randomly grouped into four: group 1 was vehicle control rats (0.1% carboxymethyl cellulose [CMC]); group 2 was rats treated with N-diethylnitrosamine (DEN) (200 mg/kg body weight [bw] i.p. on the 15th day) and ferric nitrilotriacetate (Fe-NTA) (9 mg/kg bw i.p. on 30th and 32nd days); group 3 was rats that received β-sitosterol (20 mg/kg bw in 0.1% CMC, p.o. for 32 days) 2 weeks prior to the exposure to the nephrotoxicant; and group 4 was rats that received β-sitosterol alone. The experiment was terminated after the 24 h of last dosage of Fe-NTA, and all the animals were sacrificed. The blood, liver and kidney from each group were analyzed for biochemical, molecular and histological changes.

RESULTS

All the parameters showed significant changes in DEN and Fe-NTA treated animals, whereas β-sitosterol pretreated animals' altered biochemical parameters were restored to near normal. Histopathological and immunoexpression studies on tissues also corroborate the biochemical endpoints.

CONCLUSIONS

Administration of β-sitosterol to nephrotoxicity induced rats showed significant positive changes in biochemical parameters, histopathological and immunohistochemical observations, and up-regulation of Nrf2 gene expression. From this, it was clear that β-sitosterol showed renal protective function.

MAP3K11/GDF15 axis is a critical driver of cancer cachexia

BACKGROUND

Cancer associated cachexia affects the majority of cancer patients during the course of the disease and thought to be directly responsible for about a quarter of all cancer deaths. Current evidence suggests that a pro-inflammatory state may be associated with this syndrome although the molecular mechanisms responsible for the development of cachexia are poorly understood. The purpose of this work was the identification of key drivers of cancer cachexia that could provide a potential point of intervention for the treatment and/or prevention of this syndrome.

METHODS

Genetically engineered and xenograft tumour models were used to dissect the molecular mechanisms driving cancer cachexia. Cytokine profiling from the plasma of cachectic and non-cachectic cancer patients and mouse models was utilized to correlate circulating cytokine levels with the cachexia phenotype.

RESULTS

Utilizing engineered tumour models we identified MAP3K11/GDF15 pathway activation as a potent inducer of cancer cachexia. Increased expression and high circulating levels of GDF15 acted as a key mediator of this process. In animal models, tumour-produced GDF15 was sufficient to trigger the cachexia phenotype. Elevated GDF15 circulating levels correlated with the onset and progression of cachexia in animal models and in patients with cancer. Inhibition of GDF15 biological activity with a specific antibody reversed body weight loss and restored muscle and fat tissue mass in several cachectic animal models regardless of their complex secreted cytokine profile.

CONCLUSIONS

The combination of correlative observations, gain of function, and loss of function experiments validated GDF15 as a key driver of cancer cachexia and as a potential therapeutic target for the treatment and/or prevention of this syndrome.

Preoperative inflammation-based markers predict early and late recurrence of hepatocellular carcinoma after curative hepatectomy

BACKGROUND

Recurrence of hepatocellular carcinoma (HCC) after curative resection remains a major cause of treatment failure and tumor-related death. Patterns of HCC recurrence can be categorized into early recurrence and late recurrence which have different underlying mechanisms. In this study, we investigated if simple inflammation-based clinical markers can distinguish patterns of recurrence after curative resection of HCC.

METHODS

A retrospective analysis of 223 patients who underwent curative hepatectomy for HCC was performed. Preoperative inflammation-based factors including neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio, gamma-glutamyl transferase/alanine aminotransferase ratio, aspartate aminotransferase/platelet ratio index (APRI) and prognostic nutritional index together with other clinicopathologic parameters were evaluated by univariate analysis and multivariate analysis to identify independent prognostic factors. By combining risk factors, predictive models were established to distinguish populations at high risk of early or late recurrence.

RESULTS

Age ≤50 years, resection margin ≤1 cm, TNM stage III-IV, NLR>2.75, APRI>0.23 and positive alpha-fetoprotein were independent adverse prognostic factors for early recurrence. Patients with three or more risk factors were at significant higher risk of early recurrence. APRI>0.23 and positive hepatitis B e antigen (HBeAg) were independent risk factors of late recurrence, the coexistence of high APRI and positive HBeAg increased the risk of late recurrence.

CONCLUSIONS

Preoperative inflammation-based prognostic factors predict early and late recurrence of HCC after curative resection. Different prognostic factor combinations distinguish high-risk populations of early or late HCC recurrence.

Skeletal muscle wasting and renewal: a pivotal role of myokine IL-6

Adult skeletal tissue is composed of heterogeneous population of cells that constantly self-renew by means of a controlled process of activation and proliferation of tissue-resident stem cells named satellite cells. Many growth factors, cytokines and myokines produced by skeletal muscle cells play critical roles in local regulation of the inflammatory process and skeletal muscle regeneration during different pathological conditions. IL-6 is a pleiotropic cytokine released in large amount during infection, autoimmunity and cancer. Low levels of IL-6 can promote activation of satellite cells and myotube regeneration while chronically elevated production promote skeletal muscle wasting. These distinct effects may be explained by a crosstalk of the IL-6/IL-6 receptor and gp130 trans-signaling pathway that oppose to regenerative and anti-inflammatory of the classical IL-6 receptor signaling pathway. Here we discuss on potential therapeutic strategies using monoclonal antibodies to IL-6R for the treatment of skeletal muscle wasting and cachexia. We also highlight on the IL-6/JAK/STAT and FGF/p38αβ MAPK signaling pathways in satellite cell activation and the use of protein kinase inhibitors for tailoring and optimizing satellite cell proliferation during the skeletal muscle renewal. Future investigations on the roles of the IL-6 classical and trans-signaling pathways in both immune and non-immune cells in skeletal muscle tissue will provide new basis for therapeutic approaches to reverse atrophy and degeneration of skeletal muscles in cancer and inflammatory diseases.

Therapeutic Implications for Overcoming Radiation Resistance in Cancer Therapy

Ionizing radiation (IR), such as X-rays and gamma (γ)-rays, mediates various forms of cancer cell death such as apoptosis, necrosis, autophagy, mitotic catastrophe, and senescence. Among them, apoptosis and mitotic catastrophe are the main mechanisms of IR action. DNA damage and genomic instability contribute to IR-induced cancer cell death. Although IR therapy may be curative in a number of cancer types, the resistance of cancer cells to radiation remains a major therapeutic problem. In this review, we describe the morphological and molecular aspects of various IR-induced types of cell death. We also discuss cytogenetic variations representative of IR-induced DNA damage and genomic instability. Most importantly, we focus on several pathways and their associated marker proteins responsible for cancer resistance and its therapeutic implications in terms of cancer cell death of various types and characteristics. Finally, we propose radiation-sensitization strategies, such as the modification of fractionation, inflammation, and hypoxia and the combined treatment, that can counteract the resistance of tumors to IR.

L-Carnitine Ameliorates Cancer Cachexia in Mice Partly via the Carnitine Palmitoyltransferase-Associated PPAR-γ Signaling Pathway

BACKGROUND

L-Carnitine has been demonstrated to ameliorate cachectic symptoms. In the present study, we sought to investigate the role of the peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling pathway in the ameliorative effects of L-carnitine on cancer cachexia in a colon-26 tumor-bearing mouse model.

METHODS

The cachectic mice received L-carnitine (p.o.) or etomoxir (i.p.), or pioglitazone hydrochloride (p.o.) or GW9662 (i.p.). The physiological cachexia parameters, biochemical parameters, and serum cytokines were measured. The expression levels of representative molecules in the PPAR-γ signaling pathway were measured by using quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot analysis.

RESULTS

Oral administration of L-carnitine at 9 mg/kg/day improved the cachexia parameters and biochemical parameters in cancer cachectic mice. The elevated serum concentrations of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) were decreased by L-carnitine. These ameliorative effects of L-carnitine were lessened by the carnitine palmitoyltransferase I (CPT I) inhibitor, etomoxir. The mRNA and protein expression levels of PPAR-α and PPAR-γ were decreased in the livers of cancer cachectic mice and increased after L-carnitine administration, which attenuated the increased mRNA expression levels of sterol-regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS). Similar to pioglitazone, L-carnitine augmented the phosphorylation of PPAR-γ and attenuated the expression levels of phospho-p65 and cyclooxygenase (COX)-2. Additionally, the above-mentioned effects of L-carnitine were reversed by GW9662.

CONCLUSION

L-Carnitine exerts its ameliorative effects in cancer cachexia in association with the PPAR-γ signaling pathway.

Nasopharyngeal carcinoma progression is mediated by EBER-triggered inflammation via the RIG-I pathway

EBERs (EBER1 and EBER2) are suggested to be involved in cellular transformation and tumor growth. Cytoplasmic pattern recognition receptor-RIG-I, which is characterized by the recognition of viral dsRNAs, could efficiently trigger the downstream pathways of innate immunity. Although some previous reports have shown that EBERs and RIG-I associate with hematological malignancies, the role of EBERs-RIG-I signaling in solid tumors remains to be clarified. Here we demonstrate that EBER mediation of the inflammatory response via RIG-I contributes to NPC development in vitro and in vivo. We first verified that the expression level of RIG-I was associated with EBER transcription in a dose-dependent manner in NPC cells and specimens from NPC patients. Furthermore, pro-inflammatory cytokine transcription and release were sharply reduced after RIG-I knockdown compared with the control shRNA group in the presence of EBERs, accompanied by an attenuation of the NF-κB and MAPK signaling pathways. Consequently, the tumor burden was greatly alleviated in the RIG-I knockdown group in a xenograft model. In addition, macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein (MCP-1), which promote the maturation and attraction of tumor-associated macrophages, were stimulated upon the introduction of EBERs, and this upregulation conceivably led to the tumor-promoting subset transition of the macrophages. Taken together, our results reveal that EBERs could promote NPC progression through RIG-I-mediated cancer-related inflammation.

Role of interleukin-6 in cachexia: therapeutic implications

PURPOSE OF REVIEW

Interleukin-6 (IL-6) has emerged as a cytokine involved in cachexia progression with some cancers. This review will present the recent breakthroughs in animal models and humans related to targeting IL-6 as a cancer cachexia therapy.

RECENT FINDINGS

IL-6 can target adipose, skeletal muscle, gut, and liver tissue, which can all affect cachectic patient recovery. IL-6 trans-signaling through the soluble IL-6R has the potential to amplify IL-6 signaling in the cachectic patient. In the skeletal muscle, chronic IL-6 exposure induces proteasome and autophagy protein degradation pathways that lead to wasting. IL-6 is also indirectly associated with AMP-activated kinase (AMPK) and nuclear factor kappa B (NF-κB) activation. Several mouse cancer models have clearly demonstrated that blocking IL-6 and associated signaling can attenuate cachexia progression. Additionally, pharmaceuticals targeting IL-6 and associated signaling can relieve some cachectic symptoms in cancer patients. Research with cachectic mice has demonstrated that exercise and nutraceutical administration can interact with chronic IL-6 signaling during cachexia progression.

SUMMARY

IL-6 remains a promising therapeutic strategy for attenuating cachexia progression with many types of cancer. However, improvement of this treatment will require a better understanding of the indirect and direct effects of IL-6 as well as its tissue-specific actions in the cancer patient.

Novel investigational biologics for the treatment of cancer cachexia

INTRODUCTION

Cancer cachexia is a complex multifactorial syndrome characterized by ongoing, irreversible skeletal muscle loss, leading to progressive functional impairment. Several investigational biologics targeting key inflammatory pathways and/or the myostatin/activin type II receptor pathway are in development.

AREAS COVERED

Novel therapies include ALD518, MABp1, IP-1510, OHR/AVR118, bimagrumab and REGN1033 and are discussed. For each investigational therapy, the mechanism of action, preclinical data, cachexia definition, indication and clinical data are discussed.

EXPERT OPINION

A critical look of the study protocols and two key challenges limiting the successful evaluation of these agents include: i) lack of a clinically meaningful cachexia definition; and ii) identification and treatment of cachexia in late stage. We describe our observations and clinical experience in an effort to redirect and promote successful strategies to evaluate these novel investigational biologics.

Tumor microenvironment and metabolic synergy in breast cancers: critical importance of mitochondrial fuels and function

Metabolic synergy or metabolic coupling between glycolytic stromal cells (Warburg effect) and oxidative cancer cells occurs in human breast cancers and promotes tumor growth. The Warburg effect or aerobic glycolysis is the catabolism of glucose to lactate to obtain adenosine triphosphate (ATP). This review summarizes the main findings on this stromal metabolic phenotype, and the associated signaling pathways, as well as the critical role of oxidative stress and autophagy, all of which promote carcinoma cell mitochondrial metabolism and tumor growth. Loss of Caveolin 1 (Cav-1) and the upregulation of monocarboxylate transporter 4 (MCT4) in stromal cells are novel markers of the Warburg effect and metabolic synergy between stromal and carcinoma cells. MCT4 and Cav-1 are also breast cancer prognostic biomarkers. Reactive oxygen species (ROS) are key mediators of the stromal Warburg effect. High ROS also favors cancer cell mitochondrial metabolism and tumorigenesis, and anti-oxidants can reverse this altered stromal and carcinoma metabolism. A pseudo-hypoxic state with glycolysis and low mitochondrial metabolism in the absence of hypoxia is a common feature in breast cancer. High ROS induces loss of Cav-1 in stromal cells and is sufficient to generate a pseudo-hypoxic state. Loss of Cav-1 in the stroma drives glycolysis and lactate extrusion via HIF-1α stabilization and the upregulation of MCT4. Stromal cells with loss of Cav-1 and/or high expression of MCT4 also show a catabolic phenotype, with enhanced macroautophagy. This catabolic state in stromal cells is driven by hypoxia-inducible factor (HIF)-1α, nuclear factor κB (NFκB), and JNK activation and high ROS generation. A feed-forward loop in stromal cells regulates pseudo-hypoxia and metabolic synergy, with Cav-1, MCT4, HIF-1α, NFκB, and ROS as its key elements. Metabolic synergy also may occur between cancer cells and cells in distant organs from the tumor. Cancer cachexia, which is due to severe organismal metabolic dysregulation in myocytes and adipocytes, shares similarities with stromal-carcinoma metabolic synergy, as well. In summary, metabolic synergy occurs when breast carcinoma cells induce a nutrient-rich microenvironment to promote tumor growth. The process of tumor metabolic synergy is a multistep process, due to the generation of ROS, and the induction of catabolism with autophagy, mitophagy and glycolysis. Studying epithelial-stromal interactions and metabolic synergy is important to better understand the ecology of cancer and the metabolic role of different cell types in tumor progression.

Catabolic cancer-associated fibroblasts transfer energy and biomass to anabolic cancer cells, fueling tumor growth

Fibroblasts are the most abundant "non-cancerous" cells in tumors. However, it remains largely unknown how these cancer-associated fibroblasts (CAFs) promote tumor growth and metastasis, driving chemotherapy resistance and poor clinical outcome. This review summarizes new findings on CAF signaling pathways and their emerging metabolic phenotypes that promote tumor growth. Although it is well established that altered cancer metabolism enhances tumor growth, little is known about the role of fibroblast metabolism in tumor growth. New studies reveal that metabolic coupling occurs between catabolic fibroblasts and anabolic cancer cells, in many types of human tumors, including breast, prostate, and head & neck cancers, as well as lymphomas. These catabolic phenotypes observed in CAFs are secondary to a ROS-induced metabolic stress response. Mechanistically, this occurs via HIF1-alpha and NFκB signaling, driving oxidative stress, autophagy, glycolysis and senescence in stromal fibroblasts. These catabolic CAFs then create a nutrient-rich microenvironment, to metabolically support tumor growth, via the local stromal generation of mitochondrial fuels (lactate, ketone bodies, fatty acids, glutamine, and other amino acids). New biomarkers of this catabolic CAF phenotype (such as caveolin-1 (Cav-1) and MCT4), which are reversible upon treatment with anti-oxidants, are strong predictors of poor clinical outcome in various types of human cancers. How cancer cells metabolically reprogram fibroblasts can also help us to understand the effects of cancer cells at an organismal level, explaining para-neoplastic phenomena, such as cancer cachexia. In conclusion, cancer should be viewed more as a systemic disease, that engages the host-organism in various forms of energy-transfer and metabolic co-operation, across a whole-body "ecosystem".