BACKGROUND: Cancer cachexia-induced skeletal muscle fibrosis (SMF) impairs muscle regeneration, alters the muscle structure and function, reduces the efficacy of anticancer drugs, diminishes the patient\'s quality of life and shortens overall survival. RUNX family transcription factor 2 (Runx2), a transcription factor, and collagen type I alpha 1 chain (COL1A1), the principal constituent of SMF, have been linked previously, with Runx2 shown to directly modulate COL1A1 mRNA levels. l-Carnitine, a marker of cancer cachexia, can alleviate fibrosis in liver and kidney models; however, its role in cancer cachexia-associated fibrosis and the involvement of Runx2 in the process remain unexplored.
METHODS: Female C57 mice (48 weeks old) were inoculated subcutaneously with MC38 cells to establish a cancer cachexia model. A 5 mg/kg dose of l-carnitine or an equivalent volume of water was administered for 14 days via oral gavage, followed by assessments of muscle function (grip strength) and fibrosis. To elucidate the interplay between the deltex E3 ubiquitin ligase 3L(DTX3L)/Runx2/COL1A1 axis and fibrosis in transforming growth factor beta 1-stimulated NIH/3T3 cells, a suite of molecular techniques, including quantitative real-time PCR, western blot analysis, co-immunoprecipitation, molecular docking, immunofluorescence and Duolink assays, were used. The relevance of the DTX3L/Runx2/COL1A1 axis in the gastrocnemius was also explored in the in vivo model.
RESULTS: l-Carnitine supplementation reduced cancer cachexia-induced declines in grip strength (>88.2%, P < 0.05) and the collagen fibre area within the gastrocnemius (>57.9%, P < 0.05). At the 5 mg/kg dose, l-carnitine also suppressed COL1A1 and alpha-smooth muscle actin (α-SMA) protein expression, which are markers of SMF and myofibroblasts. Analyses of the TRRUST database indicated that Runx2 regulates both COL1A1 and COL1A2. In vitro, l-carnitine diminished Runx2 protein levels and promoted its ubiquitination. Overexpression of Runx2 abolished the effects of l-carnitine on COL1A1 and α-SMA. Co-immunoprecipitation, molecular docking, immunofluorescence and Duolink assays confirmed an interaction between DTX3L and Runx2, with l-carnitine enhancing this interaction to promote Runx2 ubiquitination. l-Carnitine supplementation restored DTX3L levels to those observed under non-cachectic conditions, both in vitro and in vivo. Knockdown of DTX3L abolished the effects of l-carnitine on Runx2, COL1A1 and α-SMA in vitro. The expression of DTX3L was negatively correlated with the levels of Runx2 and COL1A1 in untreated NIH/3T3 cells.
CONCLUSIONS: This study revealed a previously unrecognized link between Runx2 and DTX3L in SMF and demonstrated that l-carnitine exerted a significant therapeutic impact on cancer cachexia-associated SMF, potentially through the upregulation of DTX3L.

BACKGROUND: Cachexia is associated with poor survival rates. In the clinical setting, the diagnosis of cancer cachexia is challenging. The cachexia index (CXI), a new index for predicting survival time, is a promising tool for diagnosing cancer cachexia; however, its efficacy in predicting patient survival has not been validated.
OBJECTIVE: This meta-analysis and systematic review aimed to explore the CXI\'s prognostic value in patients with cancer.
METHODS: The PubMed, Embase, MEDLINE, and Cochrane Library databases were searched for relevant studies to determine the association between CXI findings and prognosis.
METHODS: The outcomes were overall survival (OS), progression-, disease-, and recurrence-free survival (PFS/DFS/RFS) rates, and the rate of complete response.
METHODS: The QUality In Prognostic Studies (QUIPS) tool was used to evaluate the quality of the included trials. This meta-analysis comprised 14 studies involving 2777 patients. A low CXI was associated with decreased OS (hazard ratio [HR] 2.34, 95% confidence interval [CI] 2.01-2.72; P < .001), PFS/DFS/RFS (HR 1.93, 95% CI 1.68-2.22; P < .001), and complete response (odds ratio [OR] 0.49, 95% CI 0.36-0.66; P < .001). Patients with a low CXI had a lower body mass index (mean difference [MD] -0.75, 95% CI -1.00 to 0.50; P < .001), skeletal muscle index (standardized MD -0.80, 95% CI -0.98 to -0.61; P < .001), and serum albumin level (MD -0.23, 95% CI -0.26 to -0.20; P < .001); and a higher neutrophil-lymphocyte ratio (MD 1.88, 95% CI 1.29-2.47; P < .001) and more advanced disease stages (OR 0.80, 95% CI 0.71-0.91; P = .001).
CONCLUSIONS: A low CXI was found to be associated with poor survival in patients with cancer. While the CXI is a promising marker for predicting cancer cachexia, further studies are required to verify its usefulness.

OBJECTIVE: The characterization and prognostic value of body composition parameter/phenotype based on computed tomography (CT) in patients with digestive tract cancers remain incomplete. This study aimed to investigate the relationship between parameter/phenotype and clinical outcomes in patients with digestive tract cancers.
METHODS: In this prospective cohort study, 8267 patients with digestive tract cancers were assessed using CT scans to determine body composition. Body composition data, including areas of skeletal muscle (SM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT), were collected at the third lumbar level on CT images obtained within 30 days before surgery. Body composition phenotypes (sarcopenia, cancer cachexia, sarcopenic obesity) were determined based on SM, SAT, and VAT areas. The primary endpoint was overall survival, obtained from electronic medical records and telephone follow-up surveys. Kaplan-Meier and log-rank analyses were employed to compare unadjusted survival, while multivariate survival analyses were conducted using a proportional hazards model adjusted for age, gender, and cancer-node-metastasis (TNM) stages.
RESULTS: Adjusted hazard ratios (HRs) for all-cause mortality were calculated for the second (Q2), third (Q3), and fourth (Q4) quantiles relative to the first quantile (Q1) for SM areas, revealing adjusted summary HRs of 0.575 (95% CI, 0.361-0.916), 0.419 (95% CI, 0.241-0.729), and 0.384 (95% CI, 0.203-0.726), respectively. Sarcopenia-adjusted summary HRs were 1.795 (95% CI: 1.012-3.181) for male patients and 1.925 (95% CI: 1.065-3.478) for female patients. Cancer cachexia-adjusted summary HRs were 1.542 (95% CI: 1.023-2.324) for male patients and 1.569 (95% CI: 0.820-3.001) for female patients. Sarcopenic obesity-adjusted summary HRs were 1.122 (95% CI: 0.759-1.657) for male patients and 1.303 (95% CI: 0.623-2.725) for female patients. Subgroup analyses indicated varying prognostic values of body composition parameter/phenotype among different cancer types.
CONCLUSIONS: Our findings suggest a large SM area is a favorable prognostic indicator, while cancer cachexia and sarcopenia signify poor prognosis in patients with digestive tract cancers. These findings have important implications for the personalized preoperative assessment of body composition in patients with digestive tract cancers.

Cancer cachexia (CC) is a debilitating syndrome that affects 50-80% of cancer patients, varying in incidence by cancer type and significantly diminishing their quality of life. This multifactorial syndrome is characterized by muscle and fat loss, systemic inflammation, and metabolic imbalance. Extracellular vesicles (EVs), including exosomes and microvesicles, play a crucial role in the progression of CC. These vesicles, produced by cancer cells and others within the tumor environment, facilitate intercellular communication by transferring proteins, lipids, and nucleic acids. A comprehensive review of the literature from databases such as PubMed, Scopus, and Web of Science reveals insights into the formation, release, and uptake of EVs in CC, underscoring their potential as diagnostic and prognostic biomarkers. The review also explores therapeutic strategies targeting EVs, which include modifying their release and content, utilizing them for drug delivery, genetically altering their contents, and inhibiting key cachexia pathways. Understanding the role of EVs in CC opens new avenues for diagnostic and therapeutic approaches, potentially mitigating the syndrome\'s impact on patient survival and quality of life.

MG53, a member of the tripartite motif protein family, possesses multiple functionalities due to its classic membrane repair function, anti-inflammatory ability, and E3 ubiquitin ligase properties. Initially recognized for its crucial role in membrane repair, the therapeutic potential of MG53 has been extensively explored in various diseases including muscle injury, myocardial damage, acute lung injury, and acute kidney injury. However, further research has revealed that the E3 ubiquitin ligase characteristics of MG53 also contribute to the pathogenesis of certain conditions such as diabetic cardiomyopathy, insulin resistance, and metabolic syndrome. Moreover, recent studies have highlighted the anti-tumor effects of MG53 in different types of cancer, such as small cell lung cancer, liver cancer, and colorectal cancer; these effects are closely associated with their E3 ubiquitin ligase activities. In summary, MG53 is a multifunctional protein that participates in important physiological and pathological processes of multiple organs and is a promising therapeutic target for various human diseases. MG53 plays a multi-organ protective role due to its membrane repair function and its exertion of anti-tumor effects due to its E3 ubiquitin ligase properties. In addition, the controversial aspect of MG53\'s E3 ubiquitin ligase properties potentially causing insulin resistance and metabolic syndrome necessitates further cross-validation for clarity.

OBJECTIVE: Immune checkpoint inhibitors (ICIs) have enhanced survival in advanced esophageal squamous cell cancer (ESCC) patients, but their efficacy varies. Cachexia, characterized by muscle loss and significant weight loss, might influence ICI response. This study examines the relationship between cachexia\'s longitudinal changes and ICI outcomes in ESCC patients.
METHODS: ESCC patients undergoing at least two ICI cycles from 2017 to 2021 were studied. Cachexia\'s baseline and evolving patterns during ICI treatment were observed. Kaplan-Meier and Cox regression analyses were used to assess cachexia\'s effect on ICI efficacy. Chi-square tests were used to determine cachexia\'s link to immune-related adverse effects (irAEs).
RESULTS: Two hundred seventy-eight ICI-treated patients had a median progression-free survival (PFS) of 5.78 months and overall survival (OS) of 8.3 months. Pretreatment cachexia led to worse outcomes: PFS 7.87 versus 5.3 months, time to progression (TTP) 10.9 versus 6.1 months, and OS 14.3 versus 9.2 months. Irreversible cachexia showed the poorest results. Cachexia\'s changes weren\'t associated with irAEs.
CONCLUSIONS: Baseline and evolving cachexia significantly impact ICI efficacy in ESCC patients. Continuous cachexia monitoring during ICI therapy is crucial for optimal ESCC management.

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.

BACKGROUND: Although current guidelines(ESPEN guideline: Clinical nutrition in surgery and other guidelines) recommend preoperative immunonutrition for cachectic gastric cancer patients, the strength of the recommendation is weak, and the level of evidence is low. The benefits of preoperative immunonutrition still remain controversial.
METHODS: 112 patients with gastric cancer cachexia were enrolled in the study and randomly assigned in a 1:1 ratio to receive either preoperative enteral immunonutrition support (IN, n = 56) or standard enteral nutrition support (SEN, n = 56). The primary endpoint was the incidence of infectious complications, and the secondary endpoints included the nutritional indicators, inflammatory markers, immune parameters, postoperative recovery and complications and gastrointestinal intolerance reactions.
RESULTS: The incidence of postoperative infectious complications(P = 0.040) and overall complications (P = 0.049)was significantly lower in the IN group compared to the SEN group. In terms of laboratory inflammatory indexes, patients in the IN group demonstrated significantly lower levels of white blood cells (WBC), C-reactive protein (CRP), and interleukin-6 (IL-6), as well as higher levels of lymphocytes (LYMPH) and immunoglobulin A (IgA), compared to patients in the SEN group, with statistically significant differences. In terms of clinical outcomes, the IN group had a shorter duration of antibiotic use (P = 0.048), shorter hospital stay (P = 0.018), and lower total hospital costs (P = 0.034) compared to the SEN group. The IN group also experienced significantly less weight loss after surgery (P = 0.043).
CONCLUSIONS: Preoperative administration of immunonutrition formula has a positive impact on the incidence of infectious complications in patients with gastric cancer cachexia after surgery. It improves patients\' inflammatory and immune status, shortens hospital stays, and reduces healthcare costs. Preoperative use of immunonutrition may contribute to the improvement of prognosis in this high-risk population.

Skeletal muscle, comprising a significant proportion (40 to 50 percent) of total body weight in humans, plays a critical role in maintaining normal physiological conditions. Muscle atrophy occurs when the rate of protein degradation exceeds protein synthesis. Sarcopenia refers to age-related muscle atrophy, while cachexia represents a more complex form of muscle wasting associated with various diseases such as cancer, heart failure, and AIDS. Recent research has highlighted the involvement of signaling pathways, including IGF1-Akt-mTOR, MuRF1-MAFbx, and FOXO, in regulating the delicate balance between muscle protein synthesis and breakdown. Myostatin, a member of the TGF-β superfamily, negatively regulates muscle growth and promotes muscle atrophy by activating Smad2 and Smad3. It also interacts with other signaling pathways in cachexia and sarcopenia. Inhibition of myostatin has emerged as a promising therapeutic approach for sarcopenia and cachexia. Additionally, other TGF-β family members, such as TGF-β1, activin A, and GDF11, have been implicated in the regulation of skeletal muscle mass. Furthermore, myostatin cooperates with these family members to impair muscle differentiation and contribute to muscle loss. This review provides an overview of the significance of myostatin and other TGF-β signaling pathway members in muscular dystrophy, sarcopenia, and cachexia. It also discusses potential novel therapeutic strategies targeting myostatin and TGF-β signaling for the treatment of muscle atrophy.

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.