The role of myokines in cancer: crosstalk between skeletal muscle and tumor

MEGF6 knockdown ameliorates lenvatinib-induced muscle differentiation suppression and enhances the antitumor effect of lenvatinib on hepatocellular carcinoma

Lenvatinib (LEN)-treated patients with hepatocellular carcinoma (HCC) are frequently accompanied by skeletal muscle loss, which is correlated with poor prognosis. Interactions between tumor and skeletal muscle may play a role in patient prognosis and tumor progression. We here demonstrated that LEN hindered proliferation and differentiation of the mouse myoblast cell line, C2C12 cells, by blocking the ERK1/2 and AKT signaling pathways. Transcriptome analysis revealed that multiple EGF-like domains 6 (Megf6) was upregulated in LEN-treated C2C12 cells. Furthermore, we observed that compared with normal adjacent tissues, MEGF6 was highly expressed in HCC tumor tissues according to the TCGA database, which suggested MEGF6-mediated interaction between tumor and skeletal muscle. The Megf6 knockdown restored the differentiation inhibition caused by LEN and ERK1/2 inhibitors; however, it had no significant impact on proliferation. Regarding mechanism, LEN increased Megf6 expression through the ERK1/2 signaling pathway, thereby resulting in myostatin expression elevation and myosin heavy chain protein expression repression. Furthermore, MEGF6 in LEN-treated C2C12 cell medium promoted tumor cell proliferation and impaired C2C12 cell differentiation when cultured with LEN-treated tumor cell medium. Clinically, patients who were accompanied by muscle mass loss and increased MEGF6 serum levels had shorter progression-free survival than those who were accompanied by muscle mass loss but no increased MEGF6 serum levels before and after LEN treatment. In conclusion, MEGF6 produced from muscle and tumor cells could impair muscle differentiation and enhance tumor proliferation. Therefore, MEGF6 is worth further investigating as a target for improving the prognosis of LEN-treated patients with HCC.

Prognostic potential of neutrophil-to-lymphocyte ratio for appendicular skeletal muscle mass reduction in males aged 70 and older

Inflammation plays a pivotal role in the age-related decline of skeletal muscle mass, leading to sarcopenia in the elderly. The prevalence of sarcopenia notably increases among males aged ≥ 70. However, it remains unclear whether inflammatory indexes are associated with the reduction in skeletal muscle mass in the elderly population. Thirty-one males aged ≥ 70, without severe diseases or dementia, were enrolled in the study. They underwent muscle mass measurements, physical measurements, and hematological tests at the onset of the study and after a one-year follow-up. Twenty-eight participants were successfully followed for one year. Appendicular skeletal muscle mass index (ASMI) decreased by 3.30 ± 2.41% in 14 participants and increased by 2.66 ± 1.61% in the other 14 participants compared to baseline levels. The baseline neutrophil-to-lymphocyte ratio (NLR) was 2.14 ± 0.56 in the ASMI-decreased group and 1.66 ± 0.62 in the ASMI-increased group. A statistically significant negative correlation was found between baseline NLR and the change in ASMI in linear regression analyses. The area under the curve (AUC) of the baseline NLR for predicting ASMI decline was 0.724, with an optimal sensitivity of 64.3% and specificity of 78.6% at a cut-off value of 1.94. NLR emerged as a potential prognostic marker for ASMI reduction in elderly males. However, further studies are necessary to assess its clinical utility.

Impact of Changes in Skeletal Muscle Mass Index on Prognosis During Alternating Chemoradiotherapy in Nasopharyngeal Carcinoma

Sarcopenia is common in patients with head and neck cancer and is suggested to be associated with decreased survival. This study aimed to investigate the relationship between changes in skeletal muscle mass during alternating chemoradiotherapy (CRT) and the prognosis of patients with nasopharyngeal carcinoma (NPC). This retrospective study included 64 patients with NPC who had undergone alternating CRT at our institution between 2005 and 2022. The skeletal muscle mass index (SMI) was measured using pre- and post-treatment computed tomography. SMI decreased in 58 patients (90.6%), with a mean change of -6.1%. Using a cutoff value of -6.0% for SMI change, 32 patients (50.0%) were categorized into the SMI loss group. The SMI loss group had a significantly lower mean overall survival (OS) than the SMI maintenance group (122.6 vs. 153.0 months; p = 0.021). Multivariate analysis identified SMI loss and prognostic nutritional index (PNI) as independent predictors of poor OS (p < 0.05). They were used to construct the nomogram of OS. In conclusion, SMI loss during alternating CRT was identified as a poor prognostic factor. These findings suggest that preserving skeletal muscle mass during alternating CRT may improve the prognosis and merits further investigation.

Evaluation of preoperative visceral fat area / psoas muscle area ratio and prognosis in patients with colorectal cancer

Background

Recent research has focused on the prognostic relevance of preoperative sarcopenia and sarcopenic obesity in various cancers. In this study we investigated the relationship between visceral fat area (VFA), psoas muscle area (PMA), and the prognosis of patients undergoing colorectal cancer surgery.

Methods

Patients with stage III colorectal cancer who underwent surgery between July 2013 and April 2020 were included. The analysis was performed on 151 patients who met the criteria. The VFA and PMA were measured at the level of the third lumbar vertebra on computed tomography (CT) scans, and the ratio of VFA to PMA (V/P ratio) was determined.

Results

Patients with high V/P ratios were significantly older (p = 0.0213), had a higher body mass index (BMI) (p < 0.0001), a higher percentage of sarcopenic obesity (p < 0.0001), and more diabetes complications (p < 0.0001). Prognostic analysis showed that the overall survival (OS) (p = 0.0154) and relapse-free survival (RFS) (p = 0.0378) were significantly worse in patients with a high V/P ratio. Multivariate analysis revealed that a high V/P ratio was an independent poor prognostic factor for OS. Subgroup analysis was then performed in patients with BMI < 25 kg/m2. OS (p = 0.0259) and RFS (p = 0.0275) were significantly worse in the high V/P ratio group. A high V/P ratio was an independent poor prognostic factor in the multivariate analysis.

Conclusion

In colorectal cancer, the preoperative V/P ratio is an independent factor for poor prognosis. Preoperative evaluation of the V/P ratio may identify a wide range of high-risk patients because it is an independent poor prognostic factor in patients without obesity.

Albumin-muscle density score predicts overall survival in patients with hepatocellular cancer undergoing treatment with transarterial chemoembolization

PURPOSE

The purpose of the present study was to analyze associations between different skeletal muscle quality parameters and survival in patients with hepatocellular carcinoma (HCC) undergoing treatment with transarterial chemoembolization (TACE).

METHODS

We retrospectively enrolled 784 treatment-naïve patients with HCC undergoing TACE at six tertiary care centers between 2010 and 2020. Intramuscular adipose tissue (IMAT) and skeletal muscle density (SMD) were estimated. Myosteatosis was defined as SMD < 28.0 HU for men and < 23.8 HU for women. Furthermore, albumin-SMD score (ADS) was calculated as follows: serum albumin (g/dL) × SMD (HU). To assess the impact of muscle quality on survival, Cox regression model was used. Kaplan-Meier curves were used for survival analysis. Parameters of skeletal muscle quality were compared in univariate and multivariate regression analyses, adjusted for established risk factors.

RESULTS

In the overall sample, survivors had higher SMD and ADS in comparison to non-survivors. Patients with low ADS had a lower OS than patients with high ADS (8.4 vs. 14.3 months, p < 0.001). In alcohol-induced HCC, none of the analyzed parameters of muscle quality influenced survival. In viral induced HCC, patients with low ADS had lower OS than patients with high ADS (8.8 vs. 15.7 months, p < 0.001). In patients with non-alcoholic steatohepatitis (NASH), none of the analyzed parameters of muscle quality influenced survival.

CONCLUSIONS

Low ADS is an independent predictor of worse OS in patients with viral-induced HCC undergoing treatment with TACE. In alcohol-induced and NASH-induced HCCs, parameters of muscle quality do not influence OS.

Exercise training mode effects on myokine expression in healthy adults: A systematic review with meta-analysis

BACKGROUND

The benefits of exercise are well known; however, many of the underlying molecular mechanisms are not fully understood. Skeletal muscle secretes myokines, which mediate muscle-organ crosstalk. Myokines regulate satellite-cell proliferation and migration, inflammatory cascade, insulin secretion, angiogenesis, fatty oxidation, and cancer suppression. To date, the effects of different exercise modes (namely, aerobic and resistance exercise) on myokine response remain to be elucidated. This is crucial considering the clinical implementation of exercise to enhance general health and wellbeing and as a medical treatment.

METHODS

A systematic search was undertaken in PubMed, MEDLINE, CINAHL, Embase, SPORTDiscus, and Web of Science in April 2023. Eligible studies examining the effects of a single bout of exercise on interleukin15 (IL-15), irisin, secreted protein acidic and rich in cysteine (SPARC), oncostatin M (OSM), and decorin were included. A random-effects meta-analysis was also undertaken to quantify the magnitude of change.

RESULTS

Sixty-two studies were included (n = 1193). Overall, exercise appeared to induce small to large increases in myokine expression, with effects observed immediately after to 60 min post-exercise, although these were mostly not statistically significant. Both aerobic and resistance exercise resulted in changes in myokine levels, without any significant difference between training modes, and with the magnitude of change differing across myokines. Myokine levels returned to baseline levels within 180 min to 24 h post-exercise. However, owing to potential sources of heterogeneity, most changes were not statistically significant, indicating that precise conclusions cannot be drawn.

CONCLUSION

Knowledge is limited but expanding with respect to the impact of overall and specific effects of exercise on myokine expression at different time points in the systemic circulation. Further research is required to investigate the effects of different exercise modes at multiple time points on myokine response.

The Influence of Physical Training on Breast Cancer: The Role of Exercise-Induced Myokines in Regulating Breast Cancer Cell Growth and Survival

The beneficial impact of physical training in lowering cancer risk is well known. However, the precise mechanisms linking physical training and cancer are not fully understood. Skeletal muscle releases various myokines that seem to possess a direct anti-tumor effect. Although breast cancer (BC) is the prevalent form of cancer among women on a global scale, only limited data are available about the secretion of myokines following exercise in patients with BC. To study the effects of exercise on BC, the blood samples of patients with varied stages of BC were analyzed after 12 weeks of resistance training with whole-body electromyostimulation (WB-EMS). Following the training period, we observed that resistance training helps these patients to improve their physical characteristics and performance function by increasing skeletal muscle mass and strengthening their hand grip. Notably, the patient's serum was found to inhibit the growth and promote the apoptosis of BC cells in vitro. Moreover, the conditioned medium collected from in vitro stimulated human myotubes using electric pulse stimulation (EPS), an in vitro simulation of WB-EMS training, induced the cell death of BC cells. These results highlighted the direct cancer-protective effects of activated skeletal muscle. In line with our observed effects of serum from exercise-trained pancreatic and prostate cancer patients, the growth of BC cells was notably inhibited when supplemented directly with recombinant myokines C-X-C motif ligand 1 (CXCL1), Interleukin 10 (IL10), and C-C motif chemokine ligand 4 (CCL4). Notably, treatment with these myokines also increased the expression of caspase 3/7 (Casp3/7), resulting in enhanced BC cell death. Our data strongly suggest that physical exercise has a positive impact on skeletal muscle mass and hand grip strength in BC patients, along with a significant anti-tumor effect in BC cells. This shows promising potential for considering sports and physical training as supportive therapies for achieving more impactful cancer treatment.

Roles of natural products on myokine expression and secretion in skeletal muscle atrophy

Skeletal muscles serve both in movement and as endocrine organs. Myokines secreted by skeletal muscles activate biological functions within muscles and throughout the body via autocrine, paracrine, and/or endocrine pathways. Skeletal muscle atrophy can influence myokine expression and secretion, while myokines can impact the structure and function of skeletal muscles. Regulating the expression and secretion of myokines through the pharmacological approach is a strategy for alleviating skeletal muscle atrophy. Natural products possess complex structures and chemical properties. Previous studies have demonstrated that various natural products exert beneficial effects on skeletal muscle atrophy. This article reviewed the regulatory effects of natural products on myokines and summarized the research progress on skeletal muscle atrophy associated with myokine regulation. The focus is on how small-molecule natural products affect the regulation of interleukin 6 (IL-6), irisin, myostatin, IGF-1, and FGF-21 expression. We contend that the development of small-molecule natural products targeting the regulation of myokines holds promise in combating skeletal muscle atrophy.

Age-related and cancer-related sarcopenia: is there a difference?

PURPOSE OF REVIEW

The aim of this review is the attempt to differentiating the pathophysiologic and clinical features of the aging-related sarcopenia from cancer-related sarcopenia. In fact, there is some controversy among the experts mainly regarding two points: is always sarcopenia, even that aging-related one, the expression of a generalized disease or may exist independently and without major alteration of the muscle function? Are always aging-related and cancer-related sarcopenia completely separated entities?

RECENT FINDINGS

Literature shows that sarcopenia, defined as simple skeletal muscle mass loss, may range from a mainly focal problem which is common in many healthy elderly people, to a component of a complex multiorgan syndrome as cancer cachexia. Disuse, malnutrition and (neuro)degenerative processes can account for most of the aging-related sarcopenias while systemic inflammation and secretion of cancer-and immune-related molecules play an additional major role in cachexia.

SUMMARY

A multimodal approach including physical exercise and optimized nutritional support are the key measures to offset sarcopenia with some contribution by the anti-inflammatory drugs in cancer patients. Results are more promising in elderly patients and are still pending for cancer patients where a more specific approach will only rely on the identification and contrast of the key mediators of the cachectic process.

Mechanisms Underlying the Rarity of Skeletal Muscle Cancers

Skeletal muscle (SKM), despite comprising ~40% of body mass, rarely manifests cancer. This review explores the mechanisms that help to explain this rarity, including unique SKM architecture and function, which prohibits the development of new cancer as well as negates potential metastasis to SKM. SKM also presents a unique immune environment that may magnify the anti-tumorigenic effect. Moreover, the SKM microenvironment manifests characteristics such as decreased extracellular matrix stiffness and altered lactic acid, pH, and oxygen levels that may interfere with tumor development. SKM also secretes anti-tumorigenic myokines and other molecules. Collectively, these mechanisms help account for the rarity of SKM cancer.

The contribution of the nervous system in the cancer progression

Cancer progression is driven by genetic mutations, environmental factors, and intricate interactions within the tumor microenvironment (TME). The TME comprises of diverse cell types, such as cancer cells, immune cells, stromal cells, and neuronal cells. These cells mutually influence each other through various factors, including cytokines, vascular perfusion, and matrix stiffness. In the initial or developmental stage of cancer, neurotrophic factors such as nerve growth factor, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor are associated with poor prognosis of various cancers by communicating with cancer cells, immune cells, and peripheral nerves within the TME. Over the past decade, research has been conducted to prevent cancer growth by controlling the activation of neurotrophic factors within tumors, exhibiting a novel attemt in cancer treatment with promising results. More recently, research focusing on controlling cancer growth through regulation of the autonomic nervous system, including the sympathetic and parasympathetic nervous systems, has gained significant attention. Sympathetic signaling predominantly promotes tumor progression, while the role of parasympathetic signaling varies among different cancer types. Neurotransmitters released from these signalings can directly or indirectly affect tumor cells or immune cells within the TME. Additionally, sensory nerve significantly promotes cancer progression. In the advanced stage of cancer, cancer-associated cachexia occurs, characterized by tissue wasting and reduced quality of life. This process involves the pathways via brainstem growth and differentiation factor 15-glial cell line-derived neurotrophic factor receptor alpha-like signaling and hypothalamic proopiomelanocortin neurons. Our review highlights the critical role of neurotrophic factors as well as central nervous system on the progression of cancer, offering promising avenues for targeted therapeutic strategies. [BMB Reports 2024; 57(4): 167-175].

Secretome from Magnetically Stimulated Muscle Exhibits Anticancer Potency: Novel Preconditioning Methodology Highlighting HTRA1 Action

Briefly (10 min) exposing C2C12 myotubes to low amplitude (1.5 mT) pulsed electromagnetic fields (PEMFs) generated a conditioned media (pCM) that was capable of mitigating breast cancer cell growth, migration, and invasiveness in vitro, whereas the conditioned media harvested from unexposed myotubes, representing constitutively released secretome (cCM), was less effective. Administering pCM to breast cancer microtumors engrafted onto the chorioallantoic membrane of chicken eggs reduced tumor volume and vascularity. Blood serum collected from PEMF-exposed or exercised mice allayed breast cancer cell growth, migration, and invasiveness. A secretome preconditioning methodology is presented that accentuates the graded anticancer potencies of both the cCM and pCM harvested from myotubes, demonstrating an adaptive response to pCM administered during early myogenesis that emulated secretome-based exercise adaptations observed in vivo. HTRA1 was shown to be upregulated in pCM and was demonstrated to be necessary and sufficient for the anticancer potency of the pCM; recombinant HTRA1 added to basal media recapitulated the anticancer effects of pCM and antibody-based absorption of HTRA1 from pCM precluded its anticancer effects. Brief and non-invasive PEMF stimulation may represent a method to commandeer the secretome response of muscle, both in vitro and in vivo, for clinical exploitation in breast and other cancers.

Differences in Functional Capacity between Oncologic and Non-Oncologic Populations: Reference Values

This study is focused on the fact that in the context of increasing global aging and cancer diagnoses, additional challenges arise in clinical care. Adequate functionality and body composition are key to coping with antineoplastic treatment, which can lead to better treatment tolerance, survival, and quality of life. This is a cross-sectional comparative study focused on the assessment and comparison of body composition and functionality between cancer patients and a reference population, with the aim of establishing meaningful baseline values. Techniques such as manual dynamometry, the Five-Times Sit-to-Stand test, and bioimpedance were used to collect data from 374 oncologic patients and 1244 reference individuals. The results reveal significant disparities in functionality and body composition among participants, and provide age group-specific adjusted baseline values for those diagnosed with cancer. These findings may have crucial clinical implications for applying particular cut-off points designed for this population group, which makes the assessment process faster and more accurate, enhances the capacity of medical personnel to act quickly, and improves the management of frailty in cancer patients.

Association between Immune Checkpoint Inhibitor Treatment Outcomes and Body Composition Factors in Metastatic Renal Cell Carcinoma Patients

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of metastatic renal cell carcinoma (mRCC); however, validating body composition-related biomarkers for their efficacy remains incomplete. We evaluated the association between body composition-related markers and the prognosis of patients with mRCC who received ICI-based first-line therapies.

PATIENTS AND METHODS

We retrospectively investigated 60 patients with mRCC who underwent ICI-based therapy as their first-line treatment between 2019 and 2023. Body composition variables, including skeletal muscle, subcutaneous fat, and visceral fat indices, were calculated using baseline computed tomography scans. Sarcopenia was defined according to sex-specific cut-off values of the skeletal mass index. The associations between body composition indices and objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were evaluated.

RESULTS

Patients with sarcopenia had lower ORR and DCR than those without sarcopenia (33.3% vs. 61.1%, p = 0.0436 and 52.4% vs. 94.4%, p = 0.0024, respectively). Patients with sarcopenia had a significantly shorter median PFS (14 months vs. not reached, p = 0.0020) and OS (21 months vs. not reached, p = 0.0023) than patients without sarcopenia did. Sarcopenia was a significant predictor of PFS (hazard ratio [HR], 4.31; 95% confidence interval [CI], 1.65-14.8; p = 0.0018) and OS (HR, 5.44; 95% CI, 1.83-23.4; p = 0.0013) along with poor IMDC risk. No association was found between the subcutaneous, visceral, and total fat indices and the therapeutic effect of ICI-based therapy.

CONCLUSIONS

Sarcopenia was associated with a lower response and shorter survival rates in patients with mRCC who received first-line ICI-based therapy.

Highlighting the idea of exerkines in the management of cancer patients with cachexia: novel insights and a critical review

BACKGROUND

Exerkines are all peptides, metabolites, and nucleic acids released into the bloodstream during and after physical exercise. Exerkines liberated from skeletal muscle (myokines), the heart (cardiokines), liver (hepatokines), white adipose tissue (adipokines), brown adipose tissue (batokines), and neurons (neurokines) may benefit health and wellbeing. Cancer-related cachexia is a highly prevalent disorder characterized by weight loss with specific skeletal muscle and adipose tissue loss. Many studies have sought to provide exercise strategies for managing cachexia, focusing on musculoskeletal tissue changes. Therefore, understanding the responses of musculoskeletal and other tissue exerkines to acute and chronic exercise may provide novel insight and recommendations for physical training to counteract cancer-related cachexia.

METHODS

For the purpose of conducting this study review, we made efforts to gather relevant studies and thoroughly discuss them to create a comprehensive overview. To achieve this, we conducted searches using appropriate keywords in various databases. Studies that were deemed irrelevant to the current research, not available in English, or lacking full-text access were excluded. Nevertheless, it is important to acknowledge the limited amount of research conducted in this specific field.

RESULTS

In order to obtain a comprehensive understanding of the findings, we prioritized human studies in order to obtain results that closely align with the scope of the present study. However, in instances where human studies were limited or additional analysis was required to draw more robust conclusions, we also incorporated animal studies. Finally, 295 studies, discussed in this review.

CONCLUSION

Our understanding of the underlying physiological mechanisms related to the significance of investigating exerkines in cancer cachexia is currently quite basic. Nonetheless, this demonstrated that resistance and aerobic exercise can contribute to the reduction and control of the disease in individuals with cancer cachexia, as well as in survivors, by inducing changes in exerkines.