Autocrine activin A signalling in ovarian cancer cells regulates secretion of interleukin 6, autophagy, and cachexia

IL-6 promotes tumor growth through immune evasion but is dispensable for cachexia

Various cytokines have been implicated in cancer cachexia. One such cytokine is IL-6, deemed as a key cachectic factor in mice inoculated with colon carcinoma 26 (C26) cells, a widely used cancer cachexia model. Here we tested the causal role of IL-6 in cancer cachexia by knocking out the IL-6 gene in C26 cells. We found that the growth of IL-6 KO tumors was dramatically delayed. More strikingly, while IL-6 KO tumors eventually reached the similar size as wild-type tumors, cachexia still took place, despite no elevation in circulating IL-6. In addition, the knockout of leukemia inhibitory factor (LIF), another IL-6 family cytokine proposed as a cachectic factor in the model, also affected tumor growth but not cachexia. We further showed an increase in the infiltration of immune cell population in the IL-6 KO tumors compared with wild-type controls and the defective IL-6 KO tumor growth was rescued in immunodeficient mice while cachexia was not. Thus, IL-6 promotes tumor growth by facilitating immune evasion but is dispensable for cachexia.

Immunoregulation in cancer-associated cachexia

BACKGROUND

Cancer-associated cachexia is a multi-organ disorder associated with progressive weight loss due to a variable combination of anorexia, systemic inflammation and excessive energy wasting. Considering the importance of immunoregulation in cachexia, it still lacks a complete understanding of the immunological mechanisms in cachectic progression.

AIM OF REVIEW

Our aim here is to describe the complex immunoregulatory system in cachexia. We summarize the effects and translational potential of the immune system on the development of cancer-associated cachexia and we attempt to conclude with thoughts on precise and integrated therapeutic strategies under the complex immunological context of cachexia.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three main key concepts. First, we highlight the inflammatory factors and additional mediators that have been identified to modulate this syndrome. Second, we decipher the potential role of immune checkpoints in tissue wasting. Third, we discuss the multilayered insights in cachexia through the immunometabolic axis, immune-gut axis and immune-nerve axis.

Advancing cancer cachexia diagnosis with -omics technology and exercise as molecular medicine

Muscle atrophy exacerbates disease outcomes and increases mortality, whereas the preservation of skeletal muscle mass and function play pivotal roles in ensuring long-term health and overall quality-of-life. Muscle atrophy represents a significant clinical challenge, involving the continued loss of muscle mass and strength, which frequently accompany the development of numerous types of cancer. Cancer cachexia is a highly prevalent multifactorial syndrome, and although cachexia is one of the main causes of cancer-related deaths, there are still no approved management strategies for the disease. The etiology of this condition is based on the upregulation of systemic inflammation factors and catabolic stimuli, resulting in the inhibition of protein synthesis and enhancement of protein degradation. Numerous necessary cellular processes are disrupted by cachectic pathology, which mediate intracellular signalling pathways resulting in the net loss of muscle and organelles. However, the exact underpinning molecular mechanisms of how these changes are orchestrated are incompletely understood. Much work is still required, but structured exercise has the capacity to counteract numerous detrimental effects linked to cancer cachexia. Primarily through the stimulation of muscle protein synthesis, enhancement of mitochondrial function, and the release of myokines. As a result, muscle mass and strength increase, leading to improved mobility, and quality-of-life. This review summarises existing knowledge of the complex molecular networks that regulate cancer cachexia and exercise, highlighting the molecular interplay between the two for potential therapeutic intervention. Finally, the utility of mass spectrometry-based proteomics is considered as a way of establishing early diagnostic biomarkers of cachectic patients.

Mechanisms of Ovarian Cancer-Associated Cachexia

Cancer-associated cachexia occurs in 50% to 80% of cancer patients and is responsible for 20% to 30% of cancer-related deaths. Cachexia limits survival and treatment outcomes, and is a major contributor to morbidity and mortality during cancer. Ovarian cancer is one of the leading causes of cancer-related deaths in women, and recent studies have begun to highlight the prevalence and clinical impact of cachexia in this population. Here, we review the existing understanding of cachexia pathophysiology and summarize relevant studies assessing ovarian cancer-associated cachexia in clinical and preclinical studies. In clinical studies, there is increased evidence that reduced skeletal muscle mass and quality associate with worse outcomes in subjects with ovarian cancer. Mouse models of ovarian cancer display cachexia, often characterized by muscle and fat wasting alongside inflammation, although they remain underexplored relative to other cachexia-associated cancer types. Certain soluble factors have been identified and successfully targeted in these models, providing novel therapeutic targets for mitigating cachexia during ovarian cancer. However, given the relatively low number of studies, the translational relevance of these findings is yet to be determined and requires more research. Overall, our current understanding of ovarian cancer-associated cachexia is insufficient and this review highlights the need for future research specifically aimed at exploring mechanisms of ovarian cancer-associated cachexia by using unbiased approaches and animal models representative of the clinical landscape of ovarian cancer.

Cancer Cachexia and breast cancer stem cell signalling - A crosstalk of signalling molecules

Cancer Cachexia is a condition characterized by the involuntary loss of lean body mass, a negative protein and energy balance, and systemic inflammation. This syndrome profoundly impacts the patient's quality of life and is linked to poor chemotherapy response and reduced survival. Despite multiple mechanisms being implicated in its development, and various cytokines believed to contribute to the persistent catabolic state, cachexia is still not fully recognized and is often left untreated. Cachexia is caused by altered metabolic adaptation and lack of anticactic therapy due to systemic cytokines promoting and fuelling cancer growth. The exact molecular mechanisms and clinical endpoints remain poorly defined. It has an occurrence rate of 30%-80%, accounting for 20% of total cancer mortality. Tumor cells remodel the microenvironment suitable for their proliferation, wherein they communicate with fibroblast cells to modulate their expression and induce tumor progressive cytokines. Several studies have reported its strong correlation with systemic cytokines that initiate and aggravate the condition. Plenty of studies show the prominent role of cancer-induced cachexia in pancreatic cancer, colon cancer, and lung cancer. However, limited data are available for breast cancer-induced cachexia, highlighting the need for studying it. Breast cancer stem cells (BCSCs) are a prominently explored area in breast cancer research. They are characterized by CD44+/CD24-/ALDH+ expression and are a focus of cancer research. They are a source of renewal and differentiation within the tumor environment and are responsible for progression, and chemotherapeutic resistance. The tumor microenvironment and its cytokines are responsible for maintaining and inducing their differentiation. Cytokines significantly impact BCSC development and self-renewal, stimulating or inhibiting proliferation depending on cytokine and environment. Pro-inflammatory mediators like IL-6, TNF-α, and IL-8 increase proliferation, promoting tumor growth. Experimental models and clinical studies have shown a direct relationship between cytokines and BCSC proliferation. Several of them seem to be interconnected as they initiate signalling down different pathways but converge at BCSC increase and tumor proliferation. This review highlights the common pathways between cachexia and BCSC signalling, to identify potential therapeutic targets that can aid both conditions.

Acute Pancreatitis: Current Clinical Approaches, Molecular Pathophysiology, and Potential Therapeutics

OBJECTIVE

Severe acute pancreatitis (SAP), pancreatic inflammation leading to multiorgan failure, is associated with high morbidity and mortality. There is a critical need to identify novel therapeutic strategies to improve clinical outcomes for SAP patients.

MATERIALS AND METHODS

A comprehensive literature review was performed to identify current clinical strategies, known molecular pathophysiology, and potential therapeutic targets for SAP.

RESULTS

Current clinical approaches focus on determining which patients will likely develop SAP. However, therapeutic options are limited to supportive care and fluid resuscitation. The application of a novel 5-cytokine panel accurately predicting disease outcomes in SAP suggests that molecular approaches will improve impact of future clinical trials in AP.

CONCLUSIONS

Inflammatory outcomes in acute pancreatitis are driven by several unique molecular signals, which compound to promote both local and systemic inflammation. The identification of master cytokine regulators is critical to developing therapeutics, which reduce inflammation through several mechanisms.

Comparison of Interleukin-6 with Other Markers in Diagnosis of Ovarian Cancer

The lack of specific symptoms in ovarian cancer delays onset of the diagnostic process. Hence, most cases are recognized in late stages of the disease. The aim of this study was to confirm the role of Il-6 compared to other markers in diagnosis and survival in ovarian cancer. The database was collected from 13 January 2021 to 15 February 2023. In total, 101 patients with pelvic tumors with a mean age of 57.86 ± 16.39 participated in the study. In every case, CA125, HE4, CEA, CA19-9, Il-6, C-reactive protein and procalcitonin measurements were taken. Patients with ovarian borderline tumor and metastatic ovarian tumors were excluded from further analysis. Statistically significant correlations were found between diagnosis of ovarian cancer and levels of CA125, HE4, CRP, PCT and Il-6. Comparison of Il-6 with other markers revealed that longer overall survival correlated with lower values of Il-6. In the case of a higher concentration of Il-6, OS and PFS were shorter. Sensitivity and specificity of Il-6 in diagnosis of ovarian cancer were 46.8% and 77.8%, respectively, while for CA125, CRP and PCT were 76.6% and 63%; 68% and 57.5%; 36% and 77%, respectively. More investigations are needed to identify the most specific and sensitive marker for ovarian cancer.

IL-6 is dispensable for causing cachexia in the colon carcinoma 26 model

Various cytokines have been implicated in cancer cachexia. One such cytokine is IL-6, which has been deemed a key cachectic factor in mice inoculated with the colon carcinoma 26 (C26) cells, one of the most widely used models of cancer cachexia. Here to test the causal role of IL-6 in cancer cachexia, we used CRISPR/Cas9 editing to knock out IL-6 in C26 cells. We found that growth of IL-6 KO C26 tumors was dramatically delayed. Most strikingly, while IL-6 KO tumors eventually reached the similar size as wild-type tumors, cachexia still took place, despite no elevation in circulating IL-6. We further showed an increase of immune cell populations in IL-6 KO tumors and the defective IL-6 KO tumor growth was rescued in immunodeficient mice. Thus, our results invalidated IL-6 as a necessary factor for causing cachexia in the C26 model and revealed instead its important role in regulating tumor growth via immune suppression.

GDF15 neutralization restores muscle function and physical performance in a mouse model of cancer cachexia

Cancer cachexia is a disorder characterized by involuntary weight loss and impaired physical performance. Decline in physical performance of patients with cachexia is associated with poor quality of life, and currently there are no effective pharmacological interventions that restore physical performance. Here we examine the effect of GDF15 neutralization in a mouse model of cancer-induced cachexia (TOV21G) that manifests weight loss and muscle function impairments. With comprehensive assessments, our results demonstrate that cachectic mice treated with the anti-GDF15 antibody mAB2 exhibit body weight gain with near-complete restoration of muscle mass and markedly improved muscle function and physical performance. Mechanistically, the improvements induced by GDF15 neutralization are primarily attributed to increased caloric intake, while altered gene expression in cachectic muscles is restored in caloric-intake-dependent and -independent manners. The findings indicate potential of GDF15 neutralization as an effective therapy to enhance physical performance of patients with cachexia.

Activin A Reduces Porcine Granulosa Cells Apoptosis via ERβ-Dependent ROS Modulation

Unfavorable conditions compromise animal reproduction by altering the ovarian granulosa cells' follicular dynamics and normal physiological function (GCs), eventually resulting in oxidative damage and cell apoptosis. Activin is produced in the GCs and plays a vital role in folliculogenesis. This study investigated the effects of activin A (ACT-A) treatment in vitro on the apoptosis of porcine GCs and the underlying molecular mechanism. We found that ACT-A could attenuate the apoptosis of the GCs and enhance the synthesis of estrogen (E2). ACT-A also enhanced FSH-induced estrogen receptor-β (ERβ) expression, inhibiting ERβ aggravated intracellular accumulation of the reactive oxygen species (ROS) and apoptosis. The E2 levels in the culture medium, the mRNA expression pattern of the apoptosis-related genes (CASPASE 3, BCL2, and BAX), steroidogenesis-related gene (CYP19A1), and cell viability were analyzed to confirm the results. In summary, this study indicated the protective role of ACT-A in apoptosis by attenuating the ROS accumulation through ERβ. These results aim to enhance the follicular functions and improve animal reproductive performance.

Muscle and Bone Defects in Metastatic Disease

PURPOSE OF REVIEW

The present review addresses most recently identified mechanisms implicated in metastasis-induced bone resorption and muscle-wasting syndrome, known as cachexia.

RECENT FINDINGS

Metastatic disease in bone and soft tissues is often associated with skeletal muscle defects. Recent studies have identified a number of secreted molecules and extracellular vesicles that contribute to cancer cell growth and metastasis leading to bone destruction and muscle atrophy. In addition, alterations in muscle microenvironment including dysfunctions in hepatic and mitochondrial metabolism have been implicated in cancer-induced regeneration defect and muscle loss. Moreover, we review novel in vitro and animal models including promising new drug candidates for bone metastases and cancer cachexia. Preservation of bone health could be highly beneficial for maintaining muscle mass and function. Therefore, a better understanding of molecular pathways implicated in bone and muscle crosstalk in metastatic disease may provide new insights and identify new strategies to improve current anticancer therapeutics.

Sex specificity of pancreatic cancer cachexia phenotypes, mechanisms, and treatment in mice and humans: role of Activin

BACKGROUND

Cachexia is frequent, deadly, and untreatable for patients with pancreatic ductal adenocarcinoma (PDAC). The reproductive hormone and cytokine Activin is a mediator of PDAC cachexia, and Activin receptor targeting was clinically tested for cancer cachexia therapy. However, sex-specific manifestations and mechanisms are poorly understood, constraining development of effective treatments.

METHODS

Cachexia phenotypes, muscle gene/protein expression, and effects of the Activin blocker ACVR2B/Fc were assessed in LSL-KrasG12D/+ , LSL-Trp53R172H/+ , and Pdx-1-Cre (KPC) mice with autochthonic PDAC. Effects of PDAC and sex hormones were modelled by treating C2C12 myotubes with KPC-cell conditioned medium (CM) and estradiol. Muscle gene expression by RNAseq and change in muscle from serial CT scans were measured in patients with PDAC.

RESULTS

Despite equivalent tumour latency (median 17 weeks) and mortality (24.5 weeks), male KPC mice showed earlier and more severe cachexia than females. In early PDAC, male gastrocnemius, quadriceps, and tibialis anterior muscles were reduced (-21.7%, -18.9%, and -20.8%, respectively, all P < 0.001), with only gastrocnemius reduced in females (-16%, P < 0.01). Sex differences disappeared in late PDAC. Plasma Activin A was similarly elevated between sexes throughout, while oestrogen and testosterone levels suggested a virilizing effect of PDAC in females. Estradiol partially protected myotubes from KPC-CM induced atrophy and promoted expression of the potential Activin inhibitor Fstl1. Early-stage female mice showed greater muscle expression of Activin inhibitors Fst, Fstl1, and Fstl3; this sex difference disappeared by late-stage PDAC. ACVR2B/Fc initiated in early PDAC preserved muscle and fat only in male KPC mice, with increases of 41.2%, 52.6%, 39.3%, and 348.8%, respectively, in gastrocnemius, quadriceps, tibialis, and fat pad weights vs. vehicle controls, without effect on tumour. No protection was observed in females. At protein and RNA levels, pro-atrophy pathways were induced more strongly in early-stage males, with sex differences less evident in late-stage disease. As with mass, ACVR2B/Fc blunted atrophy-associated pathways only in males. In patients with resectable PDAC, muscle expression of Activin inhibitors FSTL1, FSLT3, and WFIKKN2/GASP2 were higher in women than men. Overall, among 124 patients on first-line gemcitabine/nab-paclitaxel for PDAC, only men displayed muscle loss (P < 0.001); average muscle wasting in men was greater (-6.63 ± 10.70% vs. -1.62 ± 12.00% mean ± SD, P = 0.038) and more rapid (-0.0098 ± 0.0742%/day vs. -0.0466 ± 0.1066%/day, P = 0.017) than in women.

CONCLUSIONS

Pancreatic ductal adenocarcinoma cachexia displays sex-specific phenotypes in mice and humans, with Activin a preferential driver of muscle wasting in males. Sex is a major modulator of cachexia mechanisms. Consideration of sexual dimorphism is essential for discovery and development of effective treatments.

Direct moxibustion exerts an analgesic effect on cervical spondylotic radiculopathy by increasing autophagy via the Act A/Smads signaling pathway

BACKGROUND

Direct moxibustion (DM) is reported to be useful for cervical spondylotic radiculopathy (CSR), but the analgesic mechanism remains unknown. Autophagy plays a protective role in neuronal apoptosis, Act A/Smads signaling pathway has been confirmed to be associated with the activation of autophagy. The study aimed to explore the effect of DM on autophagy in rats with CSR and the involvement of Act A/Smads signaling pathway.

METHODS

Rats were randomly divided into Sham, CSR, CSR + DM, CSR + DM + 3-MA (PI3K inhibitor), and CSR + DM + SB (Act A inhibitor) group. Three days after establishment of CSR model with a fish line inserted under the axilla of the nerve roots, DM at Dazhui (GV14) was performed six times once for seven consecutive days. Western blot and immunofluorescence staining were used to observe the expression of the neuronal autophagy molecule LC3II/I, Atg7, and Act A/Smads signaling molecule Act A, p-Smad2, and p-Smad3. Bcl-2/Bax mRNA expression was measured by real time PCR.

RESULTS

DM improved the pain threshold and motor function of CSR rats and promoted the expression of Act A, p-Smad2, p-Smad3, LC3II/I, and Atg7 in the entrapped-nerve root spinal dorsal horn. DM reduced the expression of Bax mRNA and decreased the number of apoptotic neurons. 3-MA and Act A inhibitor SB suppressed the expression of above-mentioned proteins and reduced the protective effect of DM on apoptotic neurons.

CONCLUSION

DM exerts analgesic effects by regulating the autophagy to reduce cell apoptosis and repair nerve injury, and this feature may be related to the Act A/Smads signaling pathway.

Myostatin/Activin Receptor Ligands in Muscle and the Development Status of Attenuating Drugs

Muscle wasting disease indications are among the most debilitating and often deadly noncommunicable disease states. As a comorbidity, muscle wasting is associated with different neuromuscular diseases and myopathies, cancer, heart failure, chronic pulmonary and renal diseases, peripheral neuropathies, inflammatory disorders, and, of course, musculoskeletal injuries. Current treatment strategies are relatively ineffective and can at best only limit the rate of muscle degeneration. This includes nutritional supplementation and appetite stimulants as well as immunosuppressants capable of exacerbating muscle loss. Arguably, the most promising treatments in development attempt to disrupt myostatin and activin receptor signaling because these circulating factors are potent inhibitors of muscle growth and regulators of muscle progenitor cell differentiation. Indeed, several studies demonstrated the clinical potential of "inhibiting the inhibitors," increasing muscle cell protein synthesis, decreasing degradation, enhancing mitochondrial biogenesis, and preserving muscle function. Such changes can prevent muscle wasting in various disease animal models yet many drugs targeting this pathway failed during clinical trials, some from serious treatment-related adverse events and off-target interactions. More often, however, failures resulted from the inability to improve muscle function despite preserving muscle mass. Drugs still in development include antibodies and gene therapeutics, all with different targets and thus, safety, efficacy, and proposed use profiles. Each is unique in design and, if successful, could revolutionize the treatment of both acute and chronic muscle wasting. They could also be used in combination with other developing therapeutics for related muscle pathologies or even metabolic diseases.

Activin A attenuates apoptosis of granulosa cells in atretic follicles through ERβ-induced autophagy

It is well known that about 99% of ovarian follicles in mammals suffer from a degenerative process known as atresia, which is a huge waste of genetic resource in female animals. Studies have shown that activin A (ACT-A) is located in ovarian granulosa cells and has different effects in granulosa cell depending on species. Although granulosa cells play a critical role during follicular atresia, the mechanism of action of ACT-A in bovine ovarian granulosa cells (BGC) is poorly understood. In this study, we firstly determined the apoptosis of BGCs isolated from growth follicles and atretic follicles, respectively. Then, BGC isolated from atretic follicles were used as a model to elucidate the role of ACT-A in cattle ovary. The results showed that apoptosis occurred in both growing follicles and atretic follicles, and the percentage of apoptotic cells in atretic follicles was higher than that in growing follicles. The current results indicated that ACT-A can attenuate apoptosis of BGC through maintaining the function of BGC in atretic follicles. Increased ERβ induced by ACT-A promoted BGC autophagy but had no effect on apoptosis. In summary, this study suggests that ACT-A attenuates BGC apoptosis in atretic follicles by ERβ-mediated autophagy signaling.

Nutrition challenges of cancer cachexia

Cancer cachexia, or progressive weight loss, often despite adequate nutrition contributes greatly to cancer morbidity and mortality. Cachexia is metabolically distinct from starvation or protein malnutrition, although many patients with cancer and cachexia exhibit lowered appetite and food consumption. Tumors affect neural mechanisms that regulate appetite and energy expenditure, while promoting wasting of peripheral tissues via catabolism of cardiac and skeletal muscle, adipose, and bone. These multimodal actions of tumors on the host suggest a need for multimodal interventions. However, multiple recent consensus guidelines for management of cancer cachexia differ in treatment recommendations, highlighting the lack of effective, available therapies. Challenges to defining appropriate nutrition or other interventions for cancer cachexia include lack of consensus on definitions, low strength of evidence from clinical trials, and a scarcity of robust, rigorous, and mechanistic studies. However, efforts to diagnose, stage, and monitor cachexia are increasing along with clinical trial activity. Furthermore, preclinical models for cancer cachexia are growing more sophisticated, encompassing a greater number of tumor types in organ-appropriate contexts and for metastatic disease to model the clinical condition more accurately. It is expected that continued growth, investment, and coordination of research in this topic will ultimately yield robust biomarkers, clinically useful classification and staging algorithms, targetable pathways, pivotal clinical trials, and ultimately, cures. Here, we provide an overview of the clinical and scientific knowledge and its limitations around cancer cachexia.

Therapeutic Influence on Important Targets Associated with Chronic Inflammation and Oxidative Stress in Cancer Treatment

Simple Summary

There is no doubt that the need for new effective methods of cancer treatment remains challenging, as cancer is the second cause of death based on the number of cases in the world. In this review, we investigated the role of one of the leading determinants in the development and progression of various types of cancer—oxidative stress and inflammation, as well as clinical and experimental data from the studies of promising drugs of natural origin, such as flavonoids, that target these stages of oncogenesis. This can all help in the expansion and systematization of the existing knowledge regarding the fight against cancer, the facilitation of the development of effective anti-cancer drugs, and the progression of research in this field, in order to improve the treatment of these disorders.

Abstract

Chronic inflammation and oxidative stress are the interconnected pathological processes, which lead to cancer initiation and progression. The growing level of oxidative and inflammatory damage was shown to increase cancer severity and contribute to tumor spread. The overproduction of reactive oxygen species (ROS), which is associated with the reduced capacity of the endogenous cell defense mechanisms and/or metabolic imbalance, is the main contributor to oxidative stress. An abnormal level of ROS was defined as a predisposing factor for the cell transformation that could trigger pro-oncogenic signaling pathways, induce changes in gene expression, and facilitate accumulation of mutations, DNA damage, and genomic instability. Additionally, the activation of transcription factors caused by a prolonged oxidative stress, including NF-κB, p53, HIF1α, etc., leads to the expression of several genes responsible for inflammation. The resulting hyperactivation of inflammatory mediators, including TNFα, TGF-β, interleukins, and prostaglandins can contribute to the development of neoplasia. Pro-inflammatory cytokines were shown to trigger adaptive reactions and the acquisition of resistance by tumor cells to apoptosis, while promoting proliferation, invasion, and angiogenesis. Moreover, the chronic inflammatory response leads to the excessive production of free radicals, which further aggravate the initiated reactions. This review summarizes the recent data and progress in the discovery of mechanisms that associate oxidative stress and chronic inflammation with cancer onset and metastasis. In addition, the review provides insights for the development of therapeutic approaches and the discovery of natural substances that will be able to simultaneously inhibit several key oncological and inflammation-related targets.

Role of autophagy in muscle disease

Beside inherited muscle diseases many catabolic conditions such as insulin resistance, malnutrition, cancer growth, aging, infections, chronic inflammatory status, inactivity, obesity are characterized by loss of muscle mass, strength and function. The decrease of muscle quality and quantity increases morbidity, mortality and has a major impact on the quality of life. One of the pathogenetic mechanisms of muscle wasting is the dysregulation of the main protein and organelles quality control system of the cell: the autophagy-lysosome. This review will focus on the role of the autophagy-lysosome system in the different conditions of muscle loss. We will also dissect the signalling pathways that are involved in excessive or defective autophagy regulation. Finally, the state of the art of autophagy modulators that have been used in preclinical or clinical studies to ameliorate muscle mass will be also described.

Skeletal Muscle Deconditioning in Breast Cancer Patients Undergoing Chemotherapy: Current Knowledge and Insights From Other Cancers

Breast cancer represents the most commonly diagnosed cancer while neoadjuvant and adjuvant chemotherapies are extensively used in order to reduce tumor development and improve disease-free survival. However, chemotherapy also leads to severe off-target side-effects resulting, together with the tumor itself, in major skeletal muscle deconditioning. This review first focuses on recent advances in both macroscopic changes and cellular mechanisms implicated in skeletal muscle deconditioning of breast cancer patients, particularly as a consequence of the chemotherapy treatment. To date, only six clinical studies used muscle biopsies in breast cancer patients and highlighted several important aspects of muscle deconditioning such as a decrease in muscle fibers cross-sectional area, a dysregulation of protein turnover balance and mitochondrial alterations. However, in comparison with the knowledge accumulated through decades of intensive research with many different animal and human models of muscle atrophy, more studies are necessary to obtain a comprehensive understanding of the cellular processes implicated in breast cancer-mediated muscle deconditioning. This understanding is indeed essential to ultimately lead to the implementation of efficient preventive strategies such as exercise, nutrition or pharmacological treatments. We therefore also discuss potential mechanisms implicated in muscle deconditioning by drawing a parallel with other cancer cachexia models of muscle wasting, both at the pre-clinical and clinical levels.

Comprehensive Characterization of Cachexia-Inducing Factors in Diffuse Large B-Cell Lymphoma Reveals a Molecular Subtype and a Prognosis-Related Signature

Background

Cachexia is defined as an involuntary decrease in body weight, which can increase the risk of death in cancer patients and reduce the quality of life. Cachexia-inducing factors (CIFs) have been reported in colorectal cancer and pancreatic adenocarcinoma, but their value in diffuse large B-cell lymphoma (DLBCL) requires further genetic research.

Methods

We used gene expression data from Gene Expression Omnibus to evaluate the expression landscape of 25 known CIFs in DLBCL patients and compared them with normal lymphoma tissues from two cohorts [GSE56315 (n = 88) and GSE12195 (n = 136)]. The mutational status of CIFs were also evaluated in The Cancer Genome Atlas database. Based on the expression profiles of 25 CIFs, a single exploratory dataset which was merged by the datasets of GSE10846 (n = 420) and GSE31312 (n = 498) were divided into two molecular subtypes by using the method of consensus clustering. Immune microenvironment between different subtypes were assessed via single-sample gene set enrichment analysis and the CIBERSORT algorithm. The treatment response of commonly used chemotherapeutic drugs was predicted and gene set variation analysis was utilized to reveal the divergence in activated pathways for distinct subtypes. A risk signature was derived by univariate Cox regression and LASSO regression in the merged dataset (n = 882), and two independent cohorts [GSE87371 (n = 221) and GSE32918 (n = 244)] were used for validation, respectively.

Results

Clustering analysis with CIFs further divided the cases into two molecular subtypes (cluster A and cluster B) associated with distinct prognosis, immunological landscape, chemosensitivity, and biological process. A risk-prognostic signature based on CCL2, CSF2, IL15, IL17A, IL4, TGFA, and TNFSF10 for DLBCL was developed, and significant differences in overall survival analysis were found between the low- and high-risk groups in the training dataset and another two independent validation datasets. Multivariate regression showed that the risk signature was an independently prognostic factor in contrast to other clinical characteristics.

Conclusion

This study demonstrated that CIFs further contribute to the observed heterogeneity of DLBCL, and molecular classification and a risk signature based on CIFs are both promising tools for prognostic stratification, which may provide important clues for precision medicine and tumor-targeted therapy.

Dehydrodiisoeugenol inhibits colorectal cancer growth by endoplasmic reticulum stress-induced autophagic pathways

Background

Dehydrodiisoeugenol (DEH), a novel lignan component extracted from nutmeg, which is the seed of Myristica fragrans Houtt, displays noticeable anti-inflammatory and anti-allergic effects in digestive system diseases. However, the mechanism of its anticancer activity in gastrointestinal cancer remains to be investigated.

Methods

In this study, the anticancer effect of DEH on human colorectal cancer and its underlying mechanism were evaluated. Assays including MTT, EdU, Plate clone formation, Soft agar, Flow cytometry, Electron microscopy, Immunofluorescence and Western blotting were used in vitro. The CDX and PDX tumor xenograft models were used in vivo.

Results

Our findings indicated that treatment with DEH arrested the cell cycle of colorectal cancer cells at the G1/S phase, leading to significant inhibition in cell growth. Moreover, DEH induced strong cellular autophagy, which could be inhibited through autophagic inhibitors, with a rction in the DEH-induced inhibition of cell growth in colorectal cancer cells. Further analysis indicated that DEH also induced endoplasmic reticulum (ER) stress and subsequently stimulated autophagy through the activation of PERK/eIF2α and IRE1α/XBP-1 s/CHOP pathways. Knockdown of PERK or IRE1α significantly decreased DEH-induced autophagy and retrieved cell viability in cells treated with DEH. Furthermore, DEH also exhibited significant anticancer activities in the CDX- and PDX-models.

Conclusions

Collectively, our studies strongly suggest that DEH might be a potential anticancer agent against colorectal cancer by activating ER stress-induced inhibition of autophagy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01915-9.

Relationship Between Early Postoperative Change in Total Psoas Muscle Area and Long-term Prognosis in Esophagectomy for Patients with Esophageal Cancer

PURPOSE

Postoperative sarcopenia following esophagectomy for esophageal cancer has become a severe problem due to the increasing number of elderly patients undergoing surgery. This study aimed to clarify the relationship between early postoperative skeletal muscle change and cancer prognosis, and propose effective interventions to prevent sarcopenia.

METHODS

This study retrospectively analyzed 152 patients who underwent esophagectomy for esophageal cancer. Total psoas muscle area (TPA) was measured before surgery as baseline and on postoperative day 7 (± 2). The effect of early postoperative skeletal muscle loss on 5-year survival was investigated. Moreover, 5-year survival in patients with postoperative complications and a high inflammatory status, which were previously reported as poor prognostic factors of esophageal cancer, was also investigated.

RESULTS

Among the 152 patients, 52 (34.2%) showed a decrease in TPA, while 100 (65.8%) maintained their TPA. The TPA decreasing group exhibited poor 5-year overall survival (OS) (p = 0.003) and 5-year recurrence-free survival (RFS) (p < 0.001). The TPA decreasing group also showed a poor 5-year OS in patients who developed severe postoperative complications (p = 0.015). Multivariate analyses showed that decreased TPA was found to be independently associated with OS (p = 0.017) as well as RFS (p = 0.002).

CONCLUSIONS

Our findings suggested a relationship between decreased TPA within 1 week after esophagectomy and long-term prognosis among patients with esophageal cancer. If TPA can be maintained, the prognosis was better even in cases with serious complications.

Withaferin A and Ovarian Cancer Antagonistically Regulate Skeletal Muscle Mass

Cachexia is a complex wasting syndrome that overwhelmingly affects the majority of late-stage cancer patients. Additionally, there are currently no efficacious therapeutic agents to treat the muscle atrophy induced by the cancer. While several preclinical studies have investigated the molecular signals orchestrating cachexia, very little information exists pertaining to ovarian cancer and the associated cachexia. Work from our lab has recently demonstrated that the steroidal lactone Withaferin A (WFA) is capable of attenuating the atrophying effects of ovarian cancer in a preclinical mouse model. However, it remained to be determined whether WFA's effect was in response to its anti-tumorigenic properties, or if it was capable of targeting skeletal muscle directly. The purpose of this study was to uncover whether WFA was capable of regulating muscle mass under tumor-free and tumor-bearing conditions. Treatment with WFA led to an improvement in functional muscle strength and mass under tumor-bearing and naïve conditions. WFA and ovarian cancer were observed to act antagonistically upon critical skeletal muscle regulatory systems, notably myogenic progenitors and proteolytic degradation pathways. Our results demonstrated for the first time that, while WFA has anti-tumorigenic properties, it also exerts hypertrophying effects on skeletal muscle mass, suggesting that it could be an anti-cachectic agent in the settings of ovarian cancer.

Cancer-Associated Muscle Wasting-Candidate Mechanisms and Molecular Pathways

Excessive muscle loss is commonly observed in cancer patients and its association with poor prognosis has been well-established. Cancer-associated sarcopenia differs from age-related wasting in that it is not responsive to nutritional intervention and exercise. This is related to its unique pathogenesis, a result of diverse and interconnected mechanisms including inflammation, disordered metabolism, proteolysis and autophagy. There is a growing body of evidence that suggests that the tumor is the driver of muscle wasting by its elaboration of mediators that influence each of these pro-sarcopenic pathways. In this review, evidence for these tumor-derived factors and putative mechanisms for inducing muscle wasting will be reviewed. Potential targets for future research and therapeutic interventions will also be reviewed.

Molecular mechanisms of cancer cachexia‑induced muscle atrophy (Review)

Muscle atrophy is a severe clinical problem involving the loss of muscle mass and strength that frequently accompanies the development of numerous types of cancer, including pancreatic, lung and gastric cancers. Cancer cachexia is a multifactorial syndrome characterized by a continuous decline in skeletal muscle mass that cannot be reversed by conventional nutritional therapy. The pathophysiological characteristic of cancer cachexia is a negative protein and energy balance caused by a combination of factors, including reduced food intake and metabolic abnormalities. Numerous necessary cellular processes are disrupted by the presence of abnormal metabolites, which mediate several intracellular signaling pathways and result in the net loss of cytoplasm and organelles in atrophic skeletal muscle during various states of cancer cachexia. Currently, the clinical morbidity and mortality rates of patients with cancer cachexia are high. Once a patient enters the cachexia phase, the consequences are difficult to reverse and the treatment methods for cancer cachexia are very limited. The present review aimed to summarize the recent discoveries regarding the pathogenesis of cancer cachexia-induced muscle atrophy and provided novel ideas for the comprehensive treatment to improve the prognosis of affected patients.

Muscle loss during primary debulking surgery and chemotherapy predicts poor survival in advanced-stage ovarian cancer

BACKGROUND

Sarcopenia is commonly observed in patients with advanced-stage epithelial ovarian cancer (EOC). However, the effect of body composition changes-during primary debulking surgery (PDS) and adjuvant platinum-based chemotherapy-on outcomes of patients with advanced-stage EOC is unknown. This study aimed to evaluate the association between body composition changes and outcomes of patients with stage III EOC treated with PDS and adjuvant platinum-based chemotherapy.

METHODS

Pre-treatment and post-treatment computed tomography (CT) images of 139 patients with stage III EOC were analysed. All CT images were contrast-enhanced scans and were acquired according to a standardized protocol. The skeletal muscle index (SMI), skeletal muscle radiodensity (SMD), and total adipose tissue index were measured using CT images obtained at the L3 vertebral level. Predictors of overall survival were identified using Cox regression models.

RESULTS

The median follow-up was 37.9 months. The median duration between pre-treatment and post-treatment CT was 182 days (interquartile range: 161-225 days). Patients experienced an average SMI loss of 1.8%/180 days (95% confidence interval: -3.1 to -0.4; P = 0.01) and SMD loss of 1.7%/180 days (95% confidence interval: -3.3 to -0.03; P = 0.046). SMI and SMD changes were weakly correlated with body mass index changes (Spearman ρ for SMI, 0.15, P = 0.07; ρ for SMD, 0.02, P = 0.82). The modified Glasgow prognostic score was associated with SMI loss (odds ratio: 2.42, 95% confidence interval: 1.03-5.69; P = 0.04). The median time to disease recurrence was significantly shorter in patients with SMI loss ≥5% after treatment than in those with SMI loss <5% or gain (5.4 vs. 11.2 months, P = 0.01). Pre-treatment SMI (1 cm² /m² decrease; hazard ratio: 1.08, 95% confidence interval: 1.03-1.11; P = 0.002) and SMI change (1%/180 days decrease; hazard ratio: 1.04, 95% confidence interval: 1.01-1.08; P = 0.002) were independently associated with poorer overall survival. SMD, body mass index, and total adipose tissue index at baseline and changes were not associated with overall survival.

CONCLUSIONS

Skeletal muscle index decreased significantly during treatment and was independently associated with poor overall survival in patients with stage III EOC treated with PDS and adjuvant platinum-based chemotherapy. The modified Glasgow prognostic score might be a predictor of SMI loss during treatment.

Targeting tumor microenvironment in ovarian cancer: Premise and promise

Ovarian cancer is the leading cause of gynecological cancer-related mortality globally. The majority of ovarian cancer patients suffer from relapse after standard of care therapies and the clinical benefits from cancer therapies are not satisfactory owing to drug resistance. Certain novel drugs targeting the components of tumor microenvironment (TME) have been approved by US Food and Drug Administration in solid cancers. As such, the passion is rekindled to exploit the role of TME in ovarian cancer progression and metastasis for discovery of novel therapeutics for this deadly disease. In the current review, we revisit the recent mechanistic insights into the contributions of TME to the development, progression, prognosis prediction and therapeutic efficacy of ovarian cancer via modulating cancer hallmarks. We also explored potentially promising predictive and prognostic biomarkers for ovarian cancer patients.

Advances in cancer cachexia: Intersection between affected organs, mediators, and pharmacological interventions

Advanced cancer patients exhibit cachexia, a condition characterized by a significant reduction in the body weight predominantly from loss of skeletal muscle and adipose tissue. Cachexia is one of the major causes of morbidity and mortality in cancer patients. Decreased food intake and multi-organ energy imbalance in cancer patients worsen the cachexia syndrome. Cachectic cancer patients have a low tolerance for chemo- and radiation therapies and also have a reduced quality of life. The presence of tumors and the current treatment options for cancer further exacerbate the cachexia condition, which remains an unmet medical need. The onset of cachexia involves crosstalk between different organs leading to muscle wasting. Recent advancements in understanding the molecular mechanisms of skeletal muscle atrophy/hypertrophy and adipose tissue wasting/browning provide a platform for the development of new targeted therapies. Therefore, a better understanding of this multifactorial disorder will help to improve the quality of life of cachectic patients. In this review, we summarize the metabolic mediators of cachexia, their molecular functions, affected organs especially with respect to muscle atrophy and adipose browning and then discuss advanced therapeutic approaches to cancer cachexia.

Autocrine activin A signalling in ovarian cancer cells regulates secretion of interleukin 6, autophagy, and cachexia

BACKGROUND

The majority of patients with advanced cancer develop cachexia, a weight loss syndrome that severely reduces quality of life and limits survival. Our understanding of the underlying mechanisms that cause the condition is limited, and there are currently no treatment options that can completely reverse cachexia. Several tumour-derived factors and inflammatory mediators have been suggested to contribute to weight loss in cachectic patients. However, inconsistencies between studies are recurrent. Activin A and interleukin 6 (IL-6) are among the best studied factors that seem to be important, and several studies support their individual role in cachexia development.

METHODS

We investigated the interplay between activin A and IL-6 in the cachexia-inducing TOV21G cell line, both in culture and in tumours in mice. We previously found that the human TOV21G cells secrete IL-6 that induces autophagy in reporter cells and cachexia in mice. Using this established cachexia cell model, we targeted autocrine activin A by genetic, chemical, and biological approaches. The secretion of IL-6 from the cancer cells was determined in both culture and tumour-bearing mice by a species-specific ELISA. Autophagy reporter cells were used to monitor the culture medium for autophagy-inducing activities, and muscle mass changes were evaluated in tumour-bearing mice.

RESULTS

We show that activin A acts in an autocrine manner to promote the synthesis and secretion of IL-6 from cancer cells. By inhibiting activin A signalling, the production of IL-6 from the cancer cells is reduced by 40-50% (up to 42% reduction on protein level, P = 0.0048, and 48% reduction on mRNA level, P = 0.0308). Significantly reduced IL-6 secretion (P < 0.05) from the cancer cells is consistently observed when using biological, chemical, and genetic approaches to interfere with the autocrine activin A loop. Inhibiting activin signalling also reduces the ability of the cancer cells to accelerate autophagy in non-cancerous cells (up to 43% reduced autophagy flux, P = 0.0006). Coherent to the in vitro data, the use of an anti-activin receptor 2 antibody in cachectic tumour-bearing mice reduces serum levels of cancer cell-derived IL-6 by 62% (from 417 to 159 pg/mL, P = 0.03), and, importantly, it reverses cachexia and counteracts loss of all measured muscle groups (P < 0.0005).

CONCLUSIONS

Our data support a functional link between activin A and IL-6 signalling pathways and indicate that interference with activin A-induced IL-6 secretion from the tumour has therapeutic potential for cancer-induced cachexia.