Molecular Mechanisms and Current Treatment Options for Cancer Cachexia

Research progress on the mechanism and treatment of cachexia based on tumor microenvironment

Cachexia is a prevalent multifactorial syndrome characterized by a substantial decrease in food intake, which results from processes such as proteolysis, lipolysis, inflammatory activation, and autophagy, ultimately leading to weight loss. In cancer patients, this condition is referred to as cancer-related cachexia (CRC) and affects over 50% of this population. A comprehensive understanding of the intricate interactions between tumors and the host organism is essential for the development of effective treatments for tumor cachexia. This review aims to elucidate the role of the tumor microenvironment (TME) in the pathogenesis of tumor-associated cachexia and to summarize the current evidence supporting treatment modalities that target the TME.

Establishment and characterization of novel cancer cachexia-inducing cell line, Aku60GC, of scirrhous gastric cancer

Cancer cachexia is a pathological state characterized by severe weight loss, skeletal muscle depletion, and adipose tissue reduction. Cancer cachexia is observed in gastric cancer (GC) with a higher incidence over 80%. Approximately 80% patients with advanced GC including scirrhous gastric cancer (SGC), which has the worst prognosis among all GC, are affected with cachexia. The exact pathophysiology in SGC cancer cachexia remains elusive, and therapeutic approaches for the cancer cachexia have not been established. Patient-derived cancer cachexia models are promising for elucidating the underlying mechanisms of disease progression and developing novel treatments, none of which originate from SGC. Therefore, we established a novel cancer cachexia-inducing cell line, designated Aku60GC, through stepwise selection of a patient-derived SGC cell line, HSC-60. Subcutaneous implantation of the Aku60GC cells into nude mice resulted in weight loss, muscle atrophy, and adipose tissue depletion with high reproducibility, accompanied by elevation of the circulating cytokines IL-8 and IL-18. Compared to parental HSC-60 cells, Aku60GC cells exhibited additional genomic changes, such as AKT2 and CCNE1 gains, a somatic mutation of RUNX1, and accelerated growth. Thus, our results demonstrate that the Aku60GC cell line is a valuable resource for research on cancer cachexia in SGC.

Biocomputational screening of natural compounds targeting 15-hydroxyprostaglandin dehydrogenase to improve skeletal muscle during aging

Skeletal muscle (SM) contains a diverse population of muscle stem (or satellite) cells, which are essential for the maintenance of muscle tissue and positively regulated by prostaglandin E2 (PGE2). However, in aged SM, PGE2 levels are reduced due to increased prostaglandin catabolism by 15-hydroxyprostaglandin dehydrogenase (15-PGDH), a negative regulator of SM tissue repair and regeneration. Screening of a library of 80,617 natural compounds in the ZINC database against 15-PGDH was conducted from PyRx. Further, drug-likeness rules, including those of Lipinski, Ghose, Veber, Egan, and Muegge were performed. The selected complex was forwarded for MD simulations up to 100ns. Based on free energy of binding obtained from docking revealed that ZINC14557836 and ZINC14638400 more potently inhibiting to 15-PGDH than SW033291 (the control and high-affinity inhibitor of 15-PGDH). The free energies of binding obtained from PyRx for 15-PGDH-ZINC14557836, 15-PGDH-ZINC14638400, and 15-PGDH-SW033291 complexes were - 10.30, -9.80, and - 8.0 kcal/mol, respectively. Root mean square deviations (RMSDs), root mean square fluctuations (RMSFs), radii of gyration (Rg), solvent-accessible surface areas (SASAs), and H-bond parameters obtained by 100 ns MD simulations predicted ZINC14557836 and ZINC14638400 more stably complexed with 15-PGDH than SW033291. The several parameters, including physicochemical properties and drug-likenesses, were within acceptable limits, and ZINC14557836 and ZINC14638400 also satisfied other drug-likeness rules, including those of Lipinski, Ghose, Veber, Egan, and Muegge. These findings suggest that ZINC14557836 and ZINC14638400 provide starting points for the development of medications that increase SM regeneration and muscle stem (or satellite) cell numbers by inhibiting 15-PGDH.

Bone-muscle crosstalk under physiological and pathological conditions

Anatomically connected bones and muscles determine movement of the body. Forces exerted on muscles are then turned to bones to promote osteogenesis. The crosstalk between muscle and bone has been identified as mechanotransduction previously. In addition to the mechanical features, bones and muscles are also secretory organs which interact closely with one another through producing myokines and osteokines. Moreover, besides the mechanical features, other factors, such as nutrition metabolism, physiological rhythm, age, etc., also affect bone-muscle crosstalk. What's more, osteogenesis and myogenesis within motor system occur almost in parallel. Pathologically, defective muscles are always detected in bone associated diseases and induce the osteopenia, inflammation and abnormal bone metabolism, etc., through biomechanical or biochemical coupling. Hence, we summarize the study findings of bone-muscle crosstalk and propose potential strategies to improve the skeletal or muscular symptoms of certain diseases. Altogether, functional improvement of bones or muscles is beneficial to each other within motor system.

Photobiomodulation therapy moderates cancer cachexia-associated muscle wasting through activating PI3K/AKT/FoxO3a pathway

Cancer cachexia-associated muscle wasting as a multifactorial wasting syndrome, is an important factor affecting the long-term survival rate of tumor patients. Photobiomodulation therapy (PBMT) has emerged as a promising tool to cure and prevent many diseases. However, the effect of PBMT on skeletal muscle atrophy during cancer progression has not been fully demonstrated yet. Here, we found PBMT alleviated the atrophy of myotube diameter induced by cancer cells in vitro, and prevented cancer-associated muscle atrophy in mice bearing tumor. Mechanistically, the alleviation of muscle wasting by PBMT was found to be involved in inhibiting E3 ubiquitin ligases MAFbx and MuRF-1. In addition, transcriptomic analysis using RNA-seq and GSEA revealed that PI3K/AKT pathway might be involved in PBMT-prevented muscle cachexia. Next, we showed the protective effect of PBMT against muscle cachexia was totally blocked by AKT inhibitor in vitro and in vivo. Moreover, PBMT-activated AKT promoted FoxO3a phosphorylation and thus inhibiting the nucleus entry of FoxO3a. Lastly, in cisplatin-treated muscle cachexia model, PBMT had also been shown to ameliorate muscle atrophy through enhancing PI3K/AKT pathway to suppress MAFbx and MuRF-1 expression. These novel findings revealed that PBMT could be a promising therapeutic approach in treating muscle cachexia induced by cancer.

Breaking Down Cachexia: A Narrative Review on the Prevalence of Cachexia in Cancer Patients and Its Associated Risk Factors

Cachexia is an irreversible condition that involves a significant loss of body weight, muscle mass, and adipose tissue. It is a complex condition that involves a variety of metabolic, hormonal, and immune-related factors, with the precise mechanisms not yet fully understood. In this review, the prevalence of cachexia in different types of cancer as well as the potential risk factors was evaluated from literature retrieved from databases such as ScienceDirect, PubMed and Scopus. Potential risk factors evaluated here include tumor-related factors such as location, and stage of the cancer, as well as patient-related factors such as age, gender, and comorbidities. Several findings were observed where cachexia is more prevalent in male cancer patients than females, with higher incidences of weight loss and poorer outcomes. This may be due to the different muscle compositions between gender. Additionally, cachexia is more prevalent at the later stages, which may be brought about by the late-stage diagnosis of certain cancers. The anatomical location of certain cancers such as the pancreas and stomach may play a significant factor in their high prevalence of cachexia. These are sites of the synthesis of digestive enzymes and hormones regulating appetite. Cachexia is an issue faced by cancer patients which could affect their recovery. However, it is poorly understood, which limit therapeutic options. Hence, understanding this disease from different perspectives (clinical and pre-clinical), and bridging those findings could further improve our comprehension and consequently improve therapeutic options.

A Phase Ib First-In-Patient Study Assessing the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Ponsegromab in Participants with Cancer and Cachexia

PURPOSE

Cachexia is common in patients with advanced cancer and is associated with elevated serum growth differentiation factor 15 (GDF-15) concentrations. This first-in-patient (phase Ib), 24-week study assessed use of ponsegromab, a mAb against GDF-15, in adults with advanced cancer, cachexia, and elevated GDF-15 serum concentration.

PATIENTS AND METHODS

Participants (n = 10) received open-label ponsegromab subcutaneous 200 mg every 3 weeks for 12 weeks in addition to standard-of-care anticancer treatment. Ponsegromab safety, tolerability, and pharmacokinetics were assessed in addition to serum GDF-15 concentrations and exploratory measures of efficacy.

RESULTS

No treatment-related treatment-emergent adverse events, injection site reactions, or adverse trends in clinical laboratory tests, vital signs, or electrocardiogram parameters attributable to ponsegromab were identified. Median serum unbound GDF-15 concentration at baseline was 2.269 ng/mL. Following initiation of study treatment, median unbound GDF-15 concentrations were below the lower limit of quantification (0.0424 ng/mL) from day 1 (3 hours postdose) through week 15. Increases in body weight were observed at all time points during the treatment and follow-up periods. A least-squares mean (SE) increase of 4.63 (1.98) kg was observed at week 12, an increase of approximately 6.6% relative to baseline. Ponsegromab-mediated improvements in actigraphy-based assessments of physical activity and in quality of life, including appetite as assessed by Functional Assessment of Anorexia-Cachexia Therapy total and subscale scores, were also observed.

CONCLUSIONS

Ponsegromab was well tolerated, suppressed serum GDF-15 concentrations, and demonstrated preliminary evidence of efficacy. These findings support the continued development of ponsegromab for the treatment of cachexia.

Molecular Mechanisms of Cachexia: A Review

Cachexia is a condition characterized by substantial loss of body weight resulting from the depletion of skeletal muscle and adipose tissue. A considerable fraction of patients with advanced cancer, particularly those who have been diagnosed with pancreatic or gastric cancer, lung cancer, prostate cancer, colon cancer, breast cancer, or leukemias, are impacted by this condition. This syndrome manifests at all stages of cancer and is associated with an unfavorable prognosis. It heightens the susceptibility to surgical complications, chemotherapy toxicity, functional impairments, breathing difficulties, and fatigue. The early detection of patients with cancer cachexia has the potential to enhance both their quality of life and overall survival rates. Regarding this matter, blood biomarkers, although helpful, possess certain limitations and do not exhibit universal application. Additionally, the available treatment options for cachexia are currently limited, and there is a lack of comprehensive understanding of the underlying molecular pathways associated with this condition. Thus, this review aims to provide an overview of molecular mechanisms associated with cachexia and potential therapeutic targets for the development of effective treatments for this devastating condition.

Therapeutic applications of ginseng for skeletal muscle-related disorder management

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

Therapeutic Applications of Ginseng Natural Compounds for Health Management

Ginseng is usually consumed as a daily food supplement to improve health and has been shown to benefit skeletal muscle, improve glucose metabolism, and ameliorate muscle-wasting conditions, cardiovascular diseases, stroke, and the effects of aging and cancers. Ginseng has also been reported to help maintain bone strength and liver (digestion, metabolism, detoxification, and protein synthesis) and kidney functions. In addition, ginseng is often used to treat age-associated neurodegenerative disorders, and ginseng and ginseng-derived natural products are popular natural remedies for diseases such as diabetes, obesity, oxidative stress, and inflammation, as well as fungal, bacterial, and viral infections. Ginseng is a well-known herbal medication, known to alleviate the actions of several cytokines. The article concludes with future directions and significant application of ginseng compounds for researchers in understanding the promising role of ginseng in the treatment of several diseases. Overall, this study was undertaken to highlight the broad-spectrum therapeutic applications of ginseng compounds for health management.

Exploring Metabolic Pathways of Anamorelin, a Selective Agonist of the Growth Hormone Secretagogue Receptor, via Molecular Networking

In this study, we delineated the poorly characterized metabolism of anamorelin, a growth hormone secretagogue receptor agonist, in vitro using human liver microsomes (HLM), based on classical molecular networking (MN) and feature-based molecular networking (FBMN) from the Global Natural Products Social Molecular Networking platform. Following the in vitro HLM reaction, the MN analysis showed 11 neighboring nodes whose information propagated from the node corresponding to anamorelin. The FBMN analysis described the separation of six nodes that the MN analysis could not achieve. In addition, the similarity among neighboring nodes could be discerned via their respective metabolic pathways. Collectively, 18 metabolites (M1-M12) were successfully identified, suggesting that the metabolic pathways involved were demethylation, hydroxylation, dealkylation, desaturation, and N-oxidation, whereas 6 metabolites (M13a*-b*, M14a*-b*, and M15a*-b*) remained unidentified. Furthermore, the major metabolites detected in HLM, M1 and M7, were dissimilar from those observed in the CYP3A4 isozyme assay, which is recognized to be markedly inhibited by anamorelin. Specifically, M7, M8, and M9 were identified as the major metabolites in the CYP3A4 isozyme assay. Therefore, a thorough investigation of metabolism is imperative for future in vivo studies. These findings may offer prospective therapeutic opportunities for anamorelin.

Modulating glucocorticoid receptor actions in physiology and pathology: Insights from coregulators

Glucocorticoids (GCs) are a class of steroid hormones that regulate key physiological processes such as metabolism, immune function, and stress responses. The effects of GCs are mediated by the glucocorticoid receptor (GR), a ligand-dependent transcription factor that activates or represses the expression of hundreds to thousands of genes in a tissue- and physiological state-specific manner. The activity of GR is modulated by numerous coregulator proteins that interact with GR in response to different stimuli assembling into a multitude of DNA-protein complexes and facilitate the integration of these signals, helping GR to communicate with basal transcriptional machinery and chromatin. Here, we provide a brief overview of the physiological and molecular functions of GR, and discuss the roles of GR coregulators in the immune system, key metabolic tissues and the central nervous system. We also present an analysis of the GR interactome in different cells and tissues, which suggests tissue-specific utilization of GR coregulators, despite widespread functions shared by some of them.

Cucurbitacin IIb attenuates cancer cachexia induced skeletal muscle atrophy by regulating the IL-6/STAT3/FoxO signaling pathway

The main features of cancer cachexia include skeletal muscle atrophy, which can significantly reduce the quality of life of patients. Clinical treatment of cancer cachexia is mainly based on nutritional therapy and physical exercise; medication only improves appetite but does not reverse the symptoms of skeletal muscle wasting. In this work, we systematically studied the underlying molecular mechanisms by which cucurbitacin IIb (CuIIb) ameliorates muscle wasting in cancer cachexia both in vitro and in vivo. CuIIb significantly ameliorated the chief features of cancer cachexia in vivo, alleviating weight loss, food intake, muscle wasting, adipose tissue depletion, and organ weight reductions. In vitro, CuIIb (10 and 20 μM) dose-dependently attenuated conditioned medium (CM)-induced C2C12 myotube atrophy. Collectively, our findings demonstrated that CuIIb prevented the upregulation of the E3 ubiquitin ligase muscle atrophy Fbox protein (MAFbx), myosin heavy chain (MyHC), and myogenin (MyoG) and impacted protein synthesis and degradation. In addition, CuIIb decreased the phosphorylation of Tyr705 in STAT3 by regulating the IL-6/STAT3/FoxO pathway to reduce skeletal muscle atrophy in cancer cachexia.

Early Detection of Therapeutic Benefit from PD-1/PD-L1 Blockade in Advanced Lung Cancer by Monitoring Cachexia-Related Circulating Cytokines

Cancer cachexia is associated with poor immunotherapeutic outcomes. This prospective observational study longitudinally evaluated the role of cachexia-related circulating cytokines in predicting the risk and benefit of PD-1/PD-L1 blockade in advanced lung cancer. Forty-one circulating cytokines at baseline and after one cycle of PD-1/PD-L1 blockade treatment were measured in patients with advanced lung cancer between 2019 and 2020. The cachexia-related cytokines were identified by comparing the levels of circulating cytokines between cachectic and non-cachectic patients. Among 55 patients, 49.1% were diagnosed with cachexia at the beginning of PD-1/PD-L1 blockade therapy. Baseline levels of the circulating cytokines IL-6, IL-8, IL-10, IL-15, and IP-10 were significantly higher in cachectic patients. In contrast, the level of eotaxin-1 was lower in cachectic patients than in those without cachexia. Higher IL-6 at baseline and during treatment was associated with a greater risk of immune-related adverse events, while higher IL-10 at baseline was linked to worse overall survival. More importantly, increased eotaxin-1 after one cycle of PD-1/PD-L1 blockade treatment was associated with higher objective response and better overall survival. A blood-based, cachexia-related cytokine assay may yield potential biomarkers for the early prediction of clinical response to PD-1/PD-L1 blockade and provide clues for improving the outcomes of cachectic patients.

Phytochemicals: A potential therapeutic intervention for the prevention and treatment of cachexia

Cachexia, a multifactorial and often irreversible wasting syndrome, is often associated with the final phase of several chronic disorders. Although cachexia is characterized by skeletal muscle wasting and adipose tissue loss, it is a syndrome affecting different organs, which ultimately results in systemic complications and impaired quality of life. The pathogenesis and underlying molecular mechanisms of cachexia are not fully understood, and currently there are no effective standard treatments or approved drug therapies to completely reverse cachexia. Moreover, adequate nutritional interventions alone cannot significantly improve cachexia. Other approaches to ameliorate cachexia are urgently needed, and thus, the role of medicinal plants has received considerable importance in this respect due to their beneficial health properties. Increasing evidence indicates great potential of medicinal plants and their phytochemicals as an alternative and promising treatment strategy to reduce the symptoms of many diseases including cachexia. This article reviews the current status of cachexia, the molecular mechanisms of primary events driving cachexia, and state-of-the-art knowledge that reports the preventive and therapeutic activities of multiple families of phytochemical compounds and their pharmacological mode of action, which may hold promise as an alternative treatment modality for the management of cachexia. Based on our review of various in vitro and in vivo models of cachexia, we would conclude that phytochemicals may have therapeutic potential to attenuate cachexia, although clinical trials are required to unequivocally confirm this premise.

Targeting cancer cachexia: Molecular mechanisms and clinical study

Cancer cachexia is a complex systemic catabolism syndrome characterized by muscle wasting. It affects multiple distant organs and their crosstalk with cancer constitute cancer cachexia environment. During the occurrence and progression of cancer cachexia, interactions of aberrant organs with cancer cells or other organs in a cancer cachexia environment initiate a cascade of stress reactions and destroy multiple organs including the liver, heart, pancreas, intestine, brain, bone, and spleen in metabolism, neural, and immune homeostasis. The role of involved organs turned from inhibiting tumor growth into promoting cancer cachexia in cancer progression. In this review, we depicted the complicated relationship of cancer cachexia with the metabolism, neural, and immune homeostasis imbalance in multiple organs in a cancer cachexia environment and summarized the treatment progress in recent years. And we discussed the molecular mechanism and clinical study of cancer cachexia from the perspective of multiple organs metabolic, neurological, and immunological abnormalities. Updated understanding of cancer cachexia might facilitate the exploration of biomarkers and novel therapeutic targets of cancer cachexia.

Identifying cancer cachexia in patients without weight loss information: machine learning approaches to address a real-world challenge

BACKGROUND

Diagnosing cancer cachexia relies extensively on patient-reported historic weight, and failure to accurately recall this information can lead to severe underestimation of cancer cachexia.

OBJECTIVES

The present study aimed to develop inexpensive tools to facilitate the identification of cancer cachexia in patients without weight loss information.

METHODS

This multicenter cohort study included 12,774 patients with cancer. Cachexia was retrospectively diagnosed using Fearon et al.'s framework. Baseline clinical features, excluding weight loss, were modeled to mimic a situation where the patient is unable to recall their weight history. Multiple machine learning (ML) models were trained using 75% of the study cohort to predict cancer cachexia, with the remaining 25% of the cohort used to assess model performance.

RESULTS

The study enrolled 6730 males and 6044 females (median age = 57.5 y). Cachexia was diagnosed in 5261 (41.2%) patients and most diagnoses were made based on the weight loss criterion. A 15-variable logistic regression (LR) model mainly comprising cancer types, gastrointestinal symptoms, tumor stage, and serum biochemistry indexes was selected among the various ML models. The LR model showed good performance for predicting cachexia in the validation data (AUC = 0.763; 95% CI: 0.747, 0.780). The calibration curve of the model demonstrated good agreement between predictions and actual observations (accuracy = 0.714, κ = 0.396, sensitivity = 0.580, specificity = 0.808, positive predictive value = 0.679, negative predictive value = 0.733). Subgroup analyses showed that the model was feasible in patients with different cancer types. The model was deployed as an online calculator and a nomogram, and was exported as predictive model markup language to permit flexible, individualized risk calculation.

CONCLUSIONS

We developed an ML model that can facilitate the identification of cancer cachexia in patients without weight loss information, which might improve decision-making and lead to the development of novel management strategies in cancer care. This trial was registered at https://www.chictr.org.cn as ChiCTR1800020329.