A comprehensive review of animal models for cancer cachexia: Implications for translational research

Branched-Chain Amino Acids and Di-Alanine Supplementation Attenuates Muscle Atrophy in a Murine Model of Cancer Cachexia

AIM

Cancer cachexia is a severe metabolic disorder leading to skeletal muscle atrophy. Muscle wasting is a major clinical problem in cachectic patients, as it limits the efficacy of chemotherapeutic treatments and worsens quality of life. Nutritional support based on branched-chain amino acids (BCAA) has been shown to be a promising approach to counteract cachexia-induced muscle atrophy, but its efficacy is still debated. Furthermore, the putative role of di-alanine (Di-Ala) supplementation has yet to be evaluated. The present study therefore sought to assess whether BCAA supplementation, alone or in combination with a Di-Ala peptide, could attenuate muscle wasting in a preclinical model of cancer cachexia.

METHODS

To this end, C26 tumor-bearing mice were administered BCAA supplementation, with or without Di-Ala. Body and muscle weights, as well as molecular, biochemical, and morphological analysis, were carried out to characterize prospective changes of markers involved in cachexia and muscle atrophy.

RESULTS

The main findings revealed that BCAA supplementation effectively prevented body weight loss and muscle atrophy. Of note, Di-Ala significantly amplified the effects of BCAA. These phenomena were found to be mediated by the suppression of pathways involved in protein catabolism.

CONCLUSIONS

Collectively, these results highlight that innovative formulations containing Di-Ala, capable of increasing BCAA bioavailability, may be efficacious in counteracting muscle atrophy, especially during mild-to-moderate cancer cachexia.

Clenbuterol and metformin ameliorate cachexia parameters, but only clenbuterol reduces tumor growth via lipid peroxidation in Walker 256 tumor-bearing rats

Cancer is the second leading cause of death worldwide. Cancer cachexia is a multifactorial catabolic syndrome responsible for almost one third of cancer-related deaths. Drug repurposing has been used in oncological research and drugs like clenbuterol and metformin seem to be reasonable candidates in the context of cancer cachexia, because the former is a β2-agonist that stimulates muscle gain and the latter has anti-inflammatory properties. The aim of this study was to assess the effects of a short-term treatment with metformin and clenbuterol, isolated or combined, on tumor growth and cancer cachexia parameters in Walker 256 tumor-bearing rats, a model of cancer cachexia. To this end, Wistar rats were separated into 8 groups and 4 of them were injected with Walker 256 tumor cells (W groups). Control (C) and W groups received the following treatments: metformin (M), clenbuterol (Cb), or metformin combined with clenbuterol (MCb). Body and tumor weight, metabolic parameters, and oxidative damage in the tumor were assessed. Compared to the C group, the W group showed body weight loss, hypoglycemia, hyperlactatemia, and hypertriacylglycerolemia. None of the treatments could reverse body weight loss, although they reversed the alterations of the assessed plasma metabolic parameters. Surprisingly, only clenbuterol alone reduced tumor weight. Hydrogen peroxide production and lipid peroxidation in tumor tissue was increased in this group. In conclusion, metformin and clenbuterol ameliorated metabolic cachexia parameters in Walker tumor-bearing rats, but only clenbuterol reduced the tumor weight, probably, through a lipid peroxidation-dependent cell death.

Progressive Cachexia: Tuberculosis, Cancer, or Thyrotoxicosis? Disease-Directed Therapy and Atypical Courses of Autoimmune and Malignant Thyroid Diseases in a High Specialization Era: Case-Control Study with a Critical Literature Review

Background. Critical and progressive cachexia may be observed in numerous medical disciplines, but in patients with various diseases, several pathways overlap (endocrine, inflammatory and kidney diseases, heart failure, cancer). Methods. Unlike numerous cohort studies that examine thyroid cancer and risk factors, a different method was used to avoid bias and analyze the sequence of events, i.e., the pathway. A case-control analysis is presented on patients with initial immune-mediated thyroiditis complicated by cachexia, presenting pulmonary pathology coexisting with opportunistic infection, and ultimately diagnosed with cancer (TC-thyroid cancer, misdiagnosed as lung cancer). Results. Contrary to other patients with lung cancer, the presented patients were not active smokers and exclusively women who developed cachexia with existing autoimmune processes in the first phase. Furthermore, the coexistence of short overall survival without cancer progression in the most seriously ill patients, as well as correlation with sex (contrary to history of smoking) and predisposition to mycobacterial disease, are very suggestive. Although we describe three different autoimmune conditions (de Quervain's, Graves', and atrophic thyroiditis), disturbances in calcium and metabolic homeostasis, under the influence of hormonal and inflammatory changes, are crucial factors of cachexia and prognosis. Conclusions. The unique sequence sheds light on immune-mediated thyroid disease as a subclinical paraneoplastic process modified by various therapeutic regimens. However, it is also associated with cachexia, systemic consequences, and atypical sequelae, which require a holistic approach. The differential diagnosis of severe cachexia, adenocarcinoma with pulmonary localization, and tuberculosis reactivation requires an analysis of immunological and genetic backgrounds. Contrary to highly specialized teams (e.g., lung cancer units), immunotherapy and general medicine in aging populations require a multidisciplinary, holistic, and inquiring approach. The lack of differentiation, confusing biases, and discrepancies in the literature are the main obstacles to statistical research, limiting findings to correlations of common factors only. Time-lapse case studies such as this one may be among the first to build evidence of a pathway and an association between inflammatory and endocrine imbalances in cancer cachexia.

Exploring heterogeneity: a dive into preclinical models of cancer cachexia

Cancer cachexia (CC) is a multifactorial and complex syndrome experienced by up to 80% of patients with cancer and implicated in ∼40% of cancer-related deaths. Given its significant impact on patients' quality of life and prognosis, there has been a growing emphasis on elucidating the underlying mechanisms of CC using preclinical models. However, the mechanisms of cachexia appear to differ across several variables including tumor type and model and biologic variables such as sex. These differences may be exacerbated by variance in experimental approaches and data reporting. This review examines literature spanning from 2011 to March 2024, focusing on common preclinical models of CC, including Lewis Lung Carcinoma, pancreatic KPC, and colorectal colon-26 and Apcmin/+ models. Our analysis reveals considerable heterogeneity in phenotypic outcomes, and investigated mechanisms within each model, with particular attention to sex differences that may be exacerbated through methodological differences. Although searching for unified mechanisms is critical, we posit that effective treatment approaches are likely to leverage the heterogeneity presented by the tumor and pertinent biological variables to direct specific interventions. In exploring this heterogeneity, it becomes critical to consider methodological and data reporting approaches to best inform further research.

Defining and Addressing Research Priorities in Cancer Cachexia through Transdisciplinary Collaboration

For many patients, the cancer continuum includes a syndrome known as cancer-associated cachexia (CAC), which encompasses the unintended loss of body weight and muscle mass, and is often associated with fat loss, decreased appetite, lower tolerance and poorer response to treatment, poor quality of life, and reduced survival. Unfortunately, there are no effective therapeutic interventions to completely reverse cancer cachexia and no FDA-approved pharmacologic agents; hence, new approaches are urgently needed. In May of 2022, researchers and clinicians from Moffitt Cancer Center held an inaugural retreat on CAC that aimed to review the state of the science, identify knowledge gaps and research priorities, and foster transdisciplinary collaborative research projects. This review summarizes research priorities that emerged from the retreat, examples of ongoing collaborations, and opportunities to move science forward. The highest priorities identified include the need to (1) evaluate patient-reported outcome (PRO) measures obtained in clinical practice and assess their use in improving CAC-related outcomes; (2) identify biomarkers (imaging, molecular, and/or behavioral) and novel analytic approaches to accurately predict the early onset of CAC and its progression; and (3) develop and test interventions (pharmacologic, nutritional, exercise-based, and through mathematical modeling) to prevent CAC progression and improve associated symptoms and outcomes.

Metabolomics-driven discovery of therapeutic targets for cancer cachexia

Cancer cachexia (CC) is a devastating metabolic syndrome characterized by skeletal muscle wasting and body weight loss, posing a significant burden on the health and survival of cancer patients. Despite ongoing efforts, effective treatments for CC are still lacking. Metabolomics, an advanced omics technique, offers a comprehensive analysis of small-molecule metabolites involved in cellular metabolism. In CC research, metabolomics has emerged as a valuable tool for identifying diagnostic biomarkers, unravelling molecular mechanisms and discovering potential therapeutic targets. A comprehensive search strategy was implemented to retrieve relevant articles from primary databases, including Web of Science, Google Scholar, Scopus and PubMed, for CC and metabolomics. Recent advancements in metabolomics have deepened our understanding of CC by uncovering key metabolic signatures and elucidating underlying mechanisms. By targeting crucial metabolic pathways including glucose metabolism, amino acid metabolism, fatty acid metabolism, bile acid metabolism, ketone body metabolism, steroid metabolism and mitochondrial energy metabolism, it becomes possible to restore metabolic balance and alleviate CC symptoms. This review provides a comprehensive summary of metabolomics studies in CC, focusing on the discovery of potential therapeutic targets and the evaluation of modulating specific metabolic pathways for CC treatment. By harnessing the insights derived from metabolomics, novel interventions for CC can be developed, leading to improved patient outcomes and enhanced quality of life.