Specialized Pro-Resolving Mediators Mitigate Cancer-Related Inflammation: Role of Tumor-Associated Macrophages and Therapeutic Opportunities

Research progress in the mechanisms and functions of specialized pro-resolving mediators in neurological diseases

The nervous system interacts with the immune system through a variety of cellular regulators, signaling pathways, and molecular mechanisms. Disruptions in these interactions lead to the development of multiple neurological diseases. Recent studies have identified that specialized pro-resolving mediators (SPMs) play a regulatory role in the neuroimmune system. This study reviews recent research on the function of SPMs in the inflammatory process and their association with the nervous system. The review aims to provide new perspectives for studying the pathogenesis of neurological diseases and identify novel targets for clinical therapy.

The intricate interplay between ferroptosis and efferocytosis in cancer: unraveling novel insights and therapeutic opportunities

The complex interplay between ferroptosis and efferocytosis in cancer has attracted significant interest recently. Efferocytosis, the process of eliminating apoptotic cells, is essential for preserving tissue homeostasis and reducing inflammation. However, dysregulation of efferocytosis can have profound effects on cancer. Apoptotic cells accumulate because of impaired efferocytosis, which triggers chronic inflammation and the release of pro-inflammatory chemicals. Surprisingly, accumulating evidence suggests that dysregulation of ferroptosis- a form of controlled cell death characterized by lipid peroxidation and the buildup iron-dependent reactive oxygen species (ROS)-can influence efferocytic activities within the tumor microenvironment. Dysfunctional iron metabolism and increased lipid peroxidation, are associated with ferroptosis, resulting in inadequate apoptotic cell clearance. Conversely, apoptotic cells can activate ferroptotic pathways, increasing oxidative stress and inducing cell death in cancer cells. This reciprocal interaction emphasizes the complex relationship between efferocytosis and ferroptosis in cancer biology. Understanding and managing the delicate balance between cell clearance and cell death pathways holds significant therapeutic potential in cancer treatment. Targeting the efferocytosis and ferroptosis pathways may offer new opportunities for improving tumor clearance, reducing inflammation, and sensitizing cancer cells to therapeutic interventions. Further research into the interaction between efferocytosis and ferroptosis in cancer will provide valuable insights for the development of novel therapies aimed at restoring tissue homeostasis and improving patient outcomes.

Resolution of chronic inflammation and cancer

Chronic inflammation poses challenges to effective cancer treatment. Although anti-inflammatory therapies have shown short-term benefits, their long-term implications may be unfavorable because they fail to initiate the necessary inflammatory responses. Recent research underscores the promise of specialized pro-resolving mediators, which play a role in modulating the cancer microenvironment by promoting the resolution of initiated inflammatory processes and restoring tissue hemostasis. This review addresses current insights into how inflammation contributes to cancer pathogenesis and explores recent strategies to resolve inflammation associated with cancer.

Targeting cyclooxygenase-2 for chemoprevention of inflammation-associated intestinal carcinogenesis: An update

Mounting evidence from preclinical and clinical studies suggests that persistent inflammation functions as a driving force in the journey to cancer. Cyclooxygenase-2 (COX-2) is a key enzyme involved in inflammatory signaling. While being transiently upregulated upon inflammatory stimuli, COX-2 has been found to be consistently overexpressed in human colorectal cancer and several other malignancies. The association between chronic inflammation and cancer has been revisited: cancer can arise when inflammation fails to resolve. Besides its proinflammatory functions, COX-2 also catalyzes the production of pro-resolving as well as anti-inflammatory metabolites from polyunsaturated fatty acids. This may account for the side effects caused by long term use of some COX-2 inhibitory drugs during the cancer chemopreventive trials. This review summarizes the latest findings highlighting the dual functions of COX-2 in the context of its implications in the development, maintenance, and progression of cancer.

EPA, DHA, and resolvin effects on cancer risk: The underexplored mechanisms

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplements have exhibited inconsistent effects on cancer risk, and their potential efficacy as cancer preventive agents has been increasingly questioned, especially in recent large randomized clinical trials. The role of host factors that govern EPA and DHA metabolism in relation to their impact on carcinogenesis remains understudied. Resolvins, the products of EPA and DHA oxidative metabolism, demonstrate intriguing antitumorigenic effects through mechanisms such as promoting macrophage phagocytosis of cell debris and inhibiting the production of proinflammatory chemokines and cytokines by tumor-associated macrophages (TAMs), which are crucial for cancer progression. However, clinical studies have not yet shown a significant increase in target tissue levels of resolvins with EPA and DHA supplementation. 15-Lipoxygenase-1 (ALOX15), a key enzyme in EPA and DHA oxidative metabolism, is often lost in various major human cancers, including precancerous and advanced colorectal cancers. Further research is needed to elucidate whether the loss of ALOX15 expression in colorectal precancerous and cancerous cells affects EPA and DHA oxidative metabolism, the formation of resolvins, and subsequently carcinogenesis. The findings from these studies could aid in the development of novel and effective chemoprevention interventions to reduce cancer risk.

Metabolic and Aging Influence on Anticancer Immunity in Oral Cancer

The average age and obesity prevalence are increasing globally. Both aging and metabolic disease burden increase the risk of oral squamous cell carcinoma (OSCC) through profound effects on the immunological and metabolic characteristics within the OSCC tumor microenvironment. While the mechanisms that link aging and obesity to OSCC remain unclear, there is evidence that the antitumor responses are diminished in both conditions. Remarkably, however, immune checkpoint blockade, a form of cancer immunotherapy, remains intact despite the enhanced immunosuppressive tumor microenvironment in the context of either aging or obesity. Herein, we review the current knowledge of how aging and systemic metabolic changes affect antitumor immunity with an emphasis on the role of tumor-associated macrophages that greatly contribute to tumor immunosuppression. Key aspects discussed include the mechanisms of angiogenesis, cytokine release, phagocytosis attenuation, and immune cell recruitment during obesity and aging that create an immune-suppressive tumor microenvironment by recruitment and repolarization of tumor-associated macrophages. Through a deeper appreciation of these mechanisms, the development of novel therapeutic approaches to control OSCC will provide more refined management of the tumor microenvironment in the context of aging and obesity.

Nature of the Association between Rheumatoid Arthritis and Cervical Cancer and Its Potential Therapeutic Implications

It is now established that patients with rheumatoid arthritis (RA) have an increased risk of developing cervical cancer (CC) or its precursor, cervical intraepithelial neoplasia (CIN). However, the underlying mechanisms of this association have not been elucidated. RA is characterized by unresolved chronic inflammation. It is suggested that human papillomavirus (HPV) infection in RA patients exacerbates inflammation, increasing the risk of CC. The tumor microenvironment in RA patients with CC is also marked by chronic inflammation, which aggravates the manifestations of both conditions. Gut and vaginal dysbiosis are also considered potential mechanisms that contribute to the chronic inflammation and aggravation of RA and CC manifestations. Numerous clinical and pre-clinical studies have demonstrated the beneficial effects of various nutritional approaches to attenuate chronic inflammation, including polyunsaturated fatty acids and their derivatives, specialized pro-resolving mediators (SPMs), probiotics, prebiotics, and certain diets. We believe that successful resolution of chronic inflammation and correction of dysbiosis, in combination with current anti-RA and anti-CC therapies, is a promising therapeutic approach for RA and CC. This approach could also reduce the risk of CC development in HPV-infected RA patients.

The "Heater" of "Cold" Tumors-Blocking IL-6

The resolution of inflammation is not simply the end of the inflammatory response but rather a complex process that involves various cells, inflammatory factors, and specialized proresolving mediators following the occurrence of inflammation. Once inflammation cannot be cleared by the body, malignant tumors may be induced. Among them, IL-6, as an immunosuppressive factor, activates a variety of signal transduction pathways and induces tumorigenesis. Monitoring IL-6 can be used for the diagnosis, efficacy evaluation and prognosis of tumor patients. In terms of treatment, improving the efficacy of targeted and immunotherapy remains a major challenge. Blocking IL-6 and its mediated signaling pathways can regulate the tumor immune microenvironment and enhance immunotherapy responses by activating immune cells. Even transform "cold" tumors that are difficult to respond to immunotherapy into immunogenic "hot" tumors, acting as a "heater" for "cold" tumors, restarting the tumor immune cycle, and reducing immunotherapy-related toxic reactions and drug resistance. In clinical practice, the combined application of IL-6 inhibition with targeted therapy and immunotherapy may produce synergistic results. Nevertheless, additional clinical trials are imperative to further validate the safety and efficacy of this therapeutic approach.

Is Lipid Metabolism of Value in Cancer Research and Treatment? Part II: Role of Specialized Pro-Resolving Mediators in Inflammation, Infections, and Cancer

Acute inflammation is the body's first defense in response to pathogens or injury that is partially governed by a novel genus of endogenous lipid mediators that orchestrate the resolution of inflammation, coined specialized pro-resolving mediators (SPMs). SPMs, derived from omega-3-polyunstaturated fatty acids (PUFAs), include the eicosapentaenoic acid-derived and docosahexaenoic acid-derived Resolvins, Protectins, and Maresins. Herein, we review their biosynthesis, structural characteristics, and therapeutic effectiveness in various diseases such as ischemia, viral infections, periodontitis, neuroinflammatory diseases, cystic fibrosis, lung inflammation, herpes virus, and cancer, especially focusing on therapeutic effectiveness in respiratory inflammation and ischemia-related injuries. Resolvins are sub-nanomolar potent agonists that accelerate the resolution of inflammation by reducing excessive neutrophil infiltration, stimulating macrophage functions including phagocytosis, efferocytosis, and tissue repair. In addition to regulating neutrophils and macrophages, Resolvins control dendritic cell migration and T cell responses, and they also reduce the pro-inflammatory cytokines, proliferation, and metastasis of cancer cells. Importantly, several lines of evidence have demonstrated that Resolvins reduce tumor progression in melanoma, oral squamous cell carcinoma, lung cancer, and liver cancer. In addition, Resolvins enhance tumor cell debris clearance by macrophages in the tumor's microenvironment. Resolvins, with their unique stereochemical structure, receptors, and biosynthetic pathways, provide a novel therapeutical approach to activating resolution mechanisms during cancer progression.

Colorectal ALOX15 as a host factor determinant of EPA and DHA effects on colorectal carcinogenesis

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), omega-3 polyunsaturated fatty acids (ω-3 PUFAs) derived from fish oil, are widely used as dietary supplements and FDA-approved treatments for hypertriglyceridemia. However, studies investigating the effects of EPA and DHA on colorectal carcinogenesis (CRC) have yielded conflicting results. The factors that determine these discrepant results remain unknown. Resolvins, oxidative metabolites of EPA and DHA, inhibit key pro-tumorigenic cytokine and chemokine signaling of colorectal cancer (e.g., IL-6, IL-1β, and CCL2). 15-lipoxygenase-1 (ALOX15), a critical enzyme for resolvin generation is commonly lost during human CRC. Whether ALOX15 expression, as a host factor, modulates the effects of EPA and DHA on CRC remains unknown. Therefore, we evaluated the effects of ALOX15 transgenic expression in colonic epithelial cells on resolvin generation by EPA and DHA and CRC in mouse models representative of human CRC. Our results revealed that 1) EPA and DHA effects on CRC were diverse, ranging from suppressive to promotive, and these effects were occasionally altered by the formulations of EPA and DHA (free fatty acid, ethyl ester, triglyceride); 2) EPA and DHA uniformly suppressed CRC in the presence of intestinal ALOX15 transgenic expression, which induced the production of resolvins, decreased colonic CCL3-5 and CXCL-5 expression and tumor associated macrophages while increasing CD8 T cell abundance in tumor microenvironment; and 3) RvD5, the predominant resolvin produced by ALOX15, inhibited macrophage generation of pro-tumorigenic cytokines. These findings demonstrate the significance of intestinal ALOX15 expression as a host factor in determining the effects of EPA and DHA on CRC.

Significance

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are widely used as dietary supplements and FDA-approved treatments for hypertriglyceridemia. Studies of EPA and DHA effects on colorectal carcinogenesis (CRC) have revealed inconsistencies; factors determining the direction of their impact on CRC have remained unidentified. Our data show that EPA and DHA effects on CRC were divergent and occasionally influenced by their formulations. More importantly, intestinal 15-lipoxgenase-1 (ALOX15) expression modulated EPA and DHA effects on CRC, leading to their consistent suppression of CRC. ALOX15 promoted EPA and DHA oxidative metabolism to generate resolvins, which inhibited key pro-tumorigenic inflammatory cytokines and chemokines, including IL-6. IL-1β, and CCL2. ALOX15 is therefore an important host factor in determining EPA and DHA effects on CRC.

Identifying the tumor-associated macrophage of lung adenocarcinoma reveals immune landscape through omics data integration

The tumor-associated macrophages (TAM) play a crucial role in lung adenocarcinoma (LUAD), which can cause the proliferation, migration and invasion of tumor cells. In particular, TAMs mainly regulate changes in the tumor microenvironment thereby contributing to tumorigenesis and progression. Recently, an increasing number of studies are using single-cell RNA (Sc-RNA) sequencing to investigate changes in the composition and transcriptomics of the tumor microenvironment. We obtained Sc-RNA sequencing data of LUAD from GEO database and transcriptome data with clinical information of LUAD patients from TCGA database. A group of important genes in the state transition of TAMs was identified by analyzing TAMs at the single-cell level, while 5 TAM-related prognostic genes were obtained by omics data integration, and a prognostic model was constructed. GOBP analysis revealed that TAM-related genes were mainly enriched in tumor-promoting and immunosuppression-related pathways. After ROC analysis, it was found that the AUC of the prognosis model reached 0.751, with well predictive effectiveness. The 5 unique genes, HLA-DMB, HMGN3, ID3, PEBP1, and TUBA1B, was finally identified through synthesized analysis. The transcriptional characteristics of 5 genes were determined through GEPIA2 database and RT-qPCR. The increased expression of TUBA1B in advanced LUAD may serve as a prognostic indicator, while low expression of PEBP1 in LUAD may have the potential to become a therapeutic target.

Advanced insights on tumor-associated macrophages revealed by single-cell RNA sequencing: The intratumor heterogeneity, functional phenotypes, and cellular interactions

Single-cell RNA sequencing (scRNA-seq) is an emerging technology used for cellular transcriptome analysis. The application of scRNA-seq has led to profoundly advanced oncology research, continuously optimizing novel therapeutic strategies. Intratumor heterogeneity extensively consists of all tumor components, contributing to different tumor behaviors and treatment responses. Tumor-associated macrophages (TAMs), the core immune cells linking innate and adaptive immunity, play significant roles in tumor progression and resistance to therapies. Moreover, dynamic changes occur in TAM phenotypes and functions subject to the regulation of the tumor microenvironment. The heterogeneity of TAMs corresponding to the state of the tumor microenvironment has been comprehensively recognized using scRNA-seq. Herein, we reviewed recent research and summarized variations in TAM phenotypes and functions from a developmental perspective to better understand the significance of TAMs in the tumor microenvironment.

Interface between Resolvins and Efferocytosis in Health and Disease

Acute inflammation resolution acts as a vital process for active host response, tissue support, and homeostasis maintenance, during which resolvin D (RvD) and E (RvE) as mediators derived from omega-3 polyunsaturated fatty acids display specific and stereoselective anti-inflammations like restricting neutrophil infiltration and pro-resolving activities. On the other side of the coin, potent macrophage-mediated apoptotic cell clearance, namely efferocytosis, is essential for successful inflammation resolution. Further studies mentioned a linkage between efferocytosis and resolvins. For instance, resolvin D1 (RvD1), which is endogenously formed from docosahexaenoic acid within the inflammation resolution, thereby provoking efferocytosis. There is still limited information regarding the mechanism of action of RvD1-related efferocytosis enhancement at the molecular level. The current review article was conducted to explore recent data on how the efferocytosis process and resolvins relate to each other during the inflammation resolution in illness and health. Understanding different aspects of this connection sheds light on new curative approaches for medical conditions caused by defective efferocytosis and disrupted inflammation resolution.

Understanding the Role of Polyunsaturated Fatty Acids in the Development and Prevention of Cancer

Polyunsaturated fatty acids (PUFAs), notably omega-3 (n-3) and omega-6 (n-6), have received much attention owing to their multifaceted effects not only in the management of diverse pathological conditions but also in the maintenance of overall health of an individual. A disproportionately high n-6 to n-3 ratio contributes to the development of various disorders including cancer, which ranks as a leading cause of death worldwide with profound social and economic burden. Epidemiological studies and clinical trials combined with the animal and cell culture models have demonstrated the beneficial effects of n-3 PUFAs in reducing the risk of various cancer types including breast, prostate and colon cancer. The anti-cancer actions of n-3 PUFAs are mainly attributed to their role in the modulation of a wide array of cellular processes including membrane dynamics, apoptosis, inflammation, angiogenesis, oxidative stress, gene expression and signal transduction pathways. On the contrary, n-6 PUFAs have been shown to exert pro-tumor actions; however, the inconsistent findings and controversial data emphasize upon the need to further investigation. Nevertheless, one of the biggest challenges in future is to optimize the n-6 to n-3 ratio despite the genetic predisposition, age, gender and disease severity. Moreover, a better understanding of the potential risks and benefits as well as the cellular and molecular mechanisms of the basic actions of these PUFAs is required to explore their role as adjuvants in cancer therapy. All these aspects will be reviewed in this chapter.

Effects of omega-3 fatty acid supplementation on nutritional status and inflammatory response in patients with stage II-III NSCLC undergoing postoperative chemotherapy: a double-blind randomized controlled trial

Background

The primary objective of this study was to investigate the effects of oral omega-3 fatty acids in lowering the risk of malnutrition and improving the inflammatory response in patients with stage II-III lung cancer receiving postoperative chemotherapy.

Methods

One hundred and three lung cancer patients identified as being at risk for malnutrition according to the 2002 nutritional risk screening criteria were randomized into either the omega-3 fatty acid supplementation group or the placebo group during postoperative chemotherapy. Data on anthropometric parameters, laboratory nutritional indicators, and inflammatory markers were collected, and changes and differences between the two groups were compared and analyzed.

Results

Sixty three patients were included in the final analysis. The baseline information of the two groups of patients was comparable (p > 0.05). After 12 weeks, patients in the treatment group exhibited significantly higher levels of hemoglobin (11.26 ± 1.25 vs.10.60 ± 0.94, p = 0.021) and serum albumin (45.38 ± 5.06 vs.42.66 ± 5.06, p = 0.036) compared with those in the placebo group. Meanwhile, the levels of inflammatory factors C-reactive protein (2.16 ± 1.06 vs. 4.11 ± 1.72, p < 0.001), interleukin-1 (6.61 ± 2.19 vs.10.85 ± 3.61, p < 0.001), interleukin-6 (2.48 ± 1.20 vs. 4.53 ± 0.98, p < 0.001), interleukin-8 (9.26 ± 2.69 vs. 39.01 ± 6.53, p < 0.001), and tumor necrosis factor-α (1.88 ± 0.60 vs. 4.07 ± 0.97, p < 0.001) were significantly decreased in the treatment group. In contrast, differences in weight, BMI, upper arm circumference, triceps skinfold thickness, triglycerides, cholesterol, and IFN-γ between the two groups were not statistically significant (p > 0.05). Finally, in the treatment group, the levels of hemoglobin (10.89 ± 1.15 vs. 11.82 ± 1.21, p = 0.042), triglyceride (0.92 ± 0.29 vs. 1.03 ± 0.22, p = 0.043), and cholesterol (3.56 ± 0.82 vs. 4.23 ± 0.88, p = 0.045) were higher in stage II patients after the intervention compared with stage III patients.

Conclusion

Supplementation with omega-3 fatty acids improved nutritional status and reduced chronic inflammatory responses in patients with stage II-III non-small cell lung cancer undergoing postoperative chemotherapy.

Clinical Trial Registration

AEA RCT Registry, identifier AEARCTR-0007165.

Immunomodulation of periodontitis with SPMs

Inflammation is a critical component in the pathophysiology of numerous disease processes, with most therapeutic modalities focusing on its inhibition in order to achieve treatment outcomes. The resolution of inflammation is a separate, distinct pathway that entails the reversal of the inflammatory process to a state of homoeostasis rather than selective inhibition of specific components of the inflammatory cascade. The discovery of specialized pro-resolving mediators (SPMs) resulted in a paradigm shift in our understanding of disease etiopathology. Periodontal disease, traditionally considered as one of microbial etiology, is now understood to be an inflammation-driven process associated with dysbiosis of the oral microbiome that may be modulated with SPMs to achieve therapeutic benefit.

ChemR23 activation reprograms macrophages toward a less inflammatory phenotype and dampens carcinoma progression

Introduction

Tumor Associated Macrophages (TAM) are a major component of the tumor environment and their accumulation often correlates with poor prognosis by contributing to local inflammation, inhibition of anti-tumor immune response and resistance to anticancer treatments. In this study, we thus investigated the anti-cancer therapeutic interest to target ChemR23, a receptor of the resolution of inflammation expressed by macrophages, using an agonist monoclonal antibody, αChemR23.

Methods

Human GM-CSF, M-CSF and Tumor Associated Macrophage (TAM)-like macrophages were obtained by incubation of monocytes from healthy donors with GM-CSF, M-CSF or tumor cell supernatants (Breast cancer (BC) or malignant pleural mesothelioma (MPM) cells). The effects of αChemR23 on macrophages were studied at the transcriptomic, protein and functional level. Datasets from The Cancer Genome Atlas (TCGA) were used to study CMKLR1 expression, coding for ChemR23, in BC and MPM tumors. In vivo, αChemR23 was evaluated on overall survival, metastasis development and transcriptomic modification of the metastatic niche using a model of resected triple negative breast cancer.

Results

We show that ChemR23 is expressed at higher levels in M-CSF and tumor cell supernatant differentiated macrophages (TAM-like) than in GM-CSF-differentiated macrophages. ChemR23 activation triggered by αChemR23 deeply modulates M-CSF and TAM-like macrophages including profile of cell surface markers, cytokine secretion, gene mRNA expression and immune functions. The expression of ChemR23 coding gene (CMKLR1) strongly correlates to TAM markers in human BC tumors and MPM and its histological detection in these tumors mainly corresponds to TAM expression. In vivo, treatment with αChemR23 agonist increased mouse survival and decreased metastasis occurrence in a model of triple-negative BC in correlation with modulation of TAM phenotype in the metastatic niche.

Conclusion

These results open an attractive opportunity to target TAM and the resolution of inflammation pathways through ChemR23 to circumvent TAM pro-tumoral effects.

Damage-mediated macrophage polarization in sterile inflammation

Most of the leading causes of death, such as cardiovascular diseases, cancer, dementia, neurodegenerative diseases, and many more, are associated with sterile inflammation, either as a cause or a consequence of these conditions. The ability to control the progression of inflammation toward tissue resolution before it becomes chronic holds significant clinical potential. During sterile inflammation, the initiation of inflammation occurs through damage-associated molecular patterns (DAMPs) in the absence of pathogen-associated molecules. Macrophages, which are primarily localized in the tissue, play a pivotal role in sensing DAMPs. Furthermore, macrophages can also detect and respond to resolution-associated molecular patterns (RAMPs) and specific pro-resolving mediators (SPMs) during sterile inflammation. Macrophages, being highly adaptable cells, are particularly influenced by changes in the microenvironment. In response to the tissue environment, monocytes, pro-inflammatory macrophages, and pro-resolution macrophages can modulate their differentiation state. Ultimately, DAMP and RAMP-primed macrophages, depending on the predominant subpopulation, regulate the balance between inflammatory and resolving processes. While sterile injury and pathogen-induced reactions may have distinct effects on macrophages, most studies have focused on macrophage responses induced by pathogens. In this review, which emphasizes available human data, we illustrate how macrophages sense these mediators by examining the expression of receptors for DAMPs, RAMPs, and SPMs. We also delve into the signaling pathways induced by DAMPs, RAMPs, and SPMs, which primarily contribute to the regulation of macrophage differentiation from a pro-inflammatory to a pro-resolution phenotype. Understanding the regulatory mechanisms behind the transition between macrophage subtypes can offer insights into manipulating the transition from inflammation to resolution in sterile inflammatory diseases.

Cytotoxic effect of crotoxin on cancer cells and its antitumoral effects correlated to tumor microenvironment: A review

Cancer is the second leading cause of death worldwide, and despite the effort of standard treatments, the search for new tools against this disease is necessary. Importantly, it is known that the tumor microenvironment plays a crucial role in tumor initiation, progression, and response to therapies. Therefore, studies of potential drugs that act on these components are as critical as studies regarding antiproliferative substances. Through the years, studies of several natural products, including animal toxins, have been conducted to guide the development of medical compounds. In this review, we present the remarkable antitumor activities of crotoxin, a toxin from the rattlesnake Crotalus durissus terrificus, highlighting its effects on cancer cells and in the modulation of relevant elements in the tumor microenvironment as well as the clinical trials conducted with this compound. In summary, crotoxin acts through several mechanisms of action, such as activation of apoptosis, induction of cell cycle arrest, inhibition of metastasis, and decrease of tumor growth, in different tumor types. Crotoxin also modulates tumor-associated fibroblasts, endothelial cells, and immune cells, which contribute to its antitumoral effects. In addition, preliminary clinical studies confirm the promising results of crotoxin and support its potential future use as an anticancer drug.

Effective holistic characterization of small molecule effects using heterogeneous biological networks

The two most common reasons for attrition in therapeutic clinical trials are efficacy and safety. We integrated heterogeneous data to create a human interactome network to comprehensively describe drug behavior in biological systems, with the goal of accurate therapeutic candidate generation. The Computational Analysis of Novel Drug Opportunities (CANDO) platform for shotgun multiscale therapeutic discovery, repurposing, and design was enhanced by integrating drug side effects, protein pathways, protein-protein interactions, protein-disease associations, and the Gene Ontology, and complemented with its existing drug/compound, protein, and indication libraries. These integrated networks were reduced to a "multiscale interactomic signature" for each compound that describe its functional behavior as vectors of real values. These signatures are then used for relating compounds to each other with the hypothesis that similar signatures yield similar behavior. Our results indicated that there is significant biological information captured within our networks (particularly via side effects) which enhance the performance of our platform, as evaluated by performing all-against-all leave-one-out drug-indication association benchmarking as well as generating novel drug candidates for colon cancer and migraine disorders corroborated via literature search. Further, drug impacts on pathways derived from computed compound-protein interaction scores served as the features for a random forest machine learning model trained to predict drug-indication associations, with applications to mental disorders and cancer metastasis highlighted. This interactomic pipeline highlights the ability of Computational Analysis of Novel Drug Opportunities to accurately relate drugs in a multitarget and multiscale context, particularly for generating putative drug candidates using the information gleaned from indirect data such as side effect profiles and protein pathway information.

Possibility of averting cytokine storm in SARS-COV 2 patients using specialized pro-resolving lipid mediators

Fatal "cytokine storms (CS)" observed in critically ill COVID-19 patients are consequences of dysregulated host immune system and over-exuberant inflammatory response. Acute respiratory distress syndrome (ARDS), multi-system organ failure, and eventual death are distinctive symptoms, attributed to higher morbidity and mortality rates among these patients. Consequent efforts to save critical COVID-19 patients via the usage of several novel therapeutic options are put in force. Strategically, drugs being used in such patients are dexamethasone, remdesivir, hydroxychloroquine, etc. along with the approved vaccines. Moreover, it is certain that activation of the resolution process is important for the prevention of chronic diseases. Until recently Inflammation resolution was considered a passive process, rather it's an active biochemical process that can be achieved by the use of specialized pro-resolving mediators (SPMs). These endogenous mediators are an array of atypical lipid metabolites that include Resolvins, lipoxins, maresins, protectins, considered as immunoresolvents, but their role in COVID-19 is ambiguous. Recent evidence from studies such as the randomized clinical trial, in which omega 3 fatty acid was used as supplement to resolve inflammation in COVID-19, suggests that direct supplementation of SPMs or the use of synthetic SPM mimetics (which are still being explored) could enhance the process of resolution by regulating the aberrant inflammatory process and can be useful in pain relief and tissue remodeling. Here we discussed the biosynthesis of SPMs, & their mechanistic pathways contributing to inflammation resolution along with sequence of events leading to CS in COVID-19, with a focus on therapeutic potential of SPMs.

Resolution therapy: Harnessing efferocytic macrophages to trigger the resolution of inflammation

Several chronic inflammatory diseases are associated with non-resolving inflammation. Conventional anti-inflammatory drugs fail to completely cure these diseases. Resolution pharmacology is a new therapeutic approach based on the use of pro-resolving mediators that accelerate the resolution phase of inflammation by targeting the productive phase of inflammation. Indeed, pro-resolving mediators prevent leukocyte recruitment and induce apoptosis of accumulated leukocytes. This approach is now called resolution therapy with the introduction of complex biological drugs and cell-based therapies. The main objective of resolution therapy is to specifically reduce the duration of the resolution phase to accelerate the return to homeostasis. Under physiological conditions, macrophages play a critical role in the resolution of inflammation. Indeed, after the removal of apoptotic cells (a process called efferocytosis), macrophages display anti-inflammatory reprogramming and subsequently secrete multiple pro-resolving factors. These factors can be used as resolution therapy. Here, we review the different mechanisms leading to anti-inflammatory reprogramming of macrophages after efferocytosis and the pro-resolving factors released by these efferocytic macrophages. We classify these mechanisms in three different categories: macrophage reprogramming induced by apoptotic cell-derived factors, by molecules expressed by apoptotic cells (i.e., "eat-me" signals), and induced by the digestion of apoptotic cell-derived materials. We also evoke that macrophage reprogramming may result from cooperative mechanisms, for instance, implicating the apoptotic cell-induced microenvironment (including cellular metabolites, specific cytokines or immune cells). Then, we describe a new drug candidate belonging to this resolution therapy. This candidate, called SuperMApo, corresponds to the secretome of efferocytic macrophages. We discuss its production, the pro-resolving factors present in this drug, as well as the results obtained in experimental models of chronic (e.g., arthritis, colitis) and acute (e.g., peritonitis or xenogeneic graft-versus-host disease) inflammatory diseases.

A systematic review of the research progress of non-coding RNA in neuroinflammation and immune regulation in cerebral infarction/ischemia-reperfusion injury

Cerebral infarction/ischemia-reperfusion injury is currently the disease with the highest mortality and disability rate of cardiovascular disease. Current studies have shown that nerve cells die of ischemia several hours after ischemic stroke, which activates the innate immune response in the brain, promotes the production of neurotoxic substances such as inflammatory cytokines, chemokines, reactive oxygen species and − nitrogen oxide, and mediates the destruction of blood-brain barrier and the occurrence of a series of inflammatory cascade reactions. Meanwhile, the expression of adhesion molecules in cerebral vascular endothelial cells increased, and immune inflammatory cells such as polymorphonuclear neutrophils, lymphocytes and mononuclear macrophages passed through vascular endothelial cells and entered the brain tissue. These cells recognize antigens exposed by the central nervous system in the brain, activate adaptive immune responses, and further mediate secondary neuronal damage, aggravating neurological deficits. In order to reduce the above-mentioned damage, the body induces peripheral immunosuppressive responses through negative feedback, which increases the incidence of post-stroke infection. This process is accompanied by changes in the immune status of the ischemic brain tissue in local and systemic systems. A growing number of studies implicate noncoding RNAs (ncRNAs) as novel epigenetic regulatory elements in the dysfunction of various cell subsets in the neurovascular unit after cerebral infarction/ischemia-reperfusion injury. In particular, recent studies have revealed advances in ncRNA biology that greatly expand the understanding of epigenetic regulation of immune responses and inflammation after cerebral infarction/ischemia-reperfusion injury. Identification of aberrant expression patterns and associated biological effects of ncRNAs in patients revealed their potential as novel biomarkers and therapeutic targets for cerebral infarction/ischemia-reperfusion injury. Therefore, this review systematically presents recent studies on the involvement of ncRNAs in cerebral infarction/ischemia-reperfusion injury and neuroimmune inflammatory cascades, and elucidates the functions and mechanisms of cerebral infarction/ischemia-reperfusion-related ncRNAs, providing new opportunities for the discovery of disease biomarkers and targeted therapy. Furthermore, this review introduces clustered regularly interspaced short palindromic repeats (CRISPR)-Display as a possible transformative tool for studying lncRNAs. In the future, ncRNA is expected to be used as a target for diagnosing cerebral infarction/ischemia-reperfusion injury, judging its prognosis and treatment, thereby significantly improving the prognosis of patients.

The Impact of Resolution of Inflammation on Tumor Microenvironment: Exploring New Ways to Control Cancer Progression

Non-resolving inflammation is an enabling feature of cancer. A novel super-family of lipid mediators termed Specialized Pro-resolving Mediators (SPMs) have a role as bioactive molecules mediating the resolution of inflammation in cancer biology. SPMs are derived from ω-3 and ω-6 polyunsaturated fatty acids through the activity of lipoxygenases. SPMs have been described to directly modulate cancer progression by interfering with the epithelial to mesenchymal transition and invasion of cancer cells. SPMs have also been demonstrated to act on several components of the tumor microenvironment (TME). Consistently with their natural immunomodulatory and anti-inflammatory properties, SPMs are able to reprogram macrophages to favor phagocytosis of cell debris, which are an important source of pro-inflammatory and pro-angiogenic signals; sustain a direct cytotoxic immune response against cancer cells; stimulate neutrophils anti-tumor activities; and inhibit the development of regulatory T and B cells, thus indirectly leading to enhanced anti-tumor immunity. Furthermore, the resolution pathways exert crucial anti-angiogenic functions in lung, liver, and gastrointestinal cancers, and inhibit cancer-associated fibroblast differentiation and functions in hepatocellular carcinoma and pancreatic cancer. The present review will be focused on the potential protective effects of resolution pathways against cancer, exerted by modulating different components of the TME.

Effects of statins on specialized pro-resolving mediators: An additional pathway leading to resolution of inflammation

Statins are a class of cholesterol-lowering drugs that inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Anti-inflammatory and antioxidant properties, as well as improvement of endothelial function and plaque stabilization have also been proposed as parts of the pleiotropic effects of statins. Specialized pro-resolving mediators (SPMs) are endogenous lipid-derived molecules originating from ω-6 and ω-3 polyunsaturated fatty acids, such as arachidonic, docosahexaenoic and eicosapentaenoic acid that trigger and modulate the resolution of inflammation. Impaired SPM biosynthesis can lead to excessive or chronic inflammation and is implicated in the pathogenesis of several diseases. Exogenous administration of SPMs, including lipoxin, maresin, protectin, have been shown to improve both bacterial and viral infections, mainly in preclinical models, thus minimizing inflammation. Statin-triggered-SPM production in several in vitro and in vivo models may represent another anti-inflammatory pathway involving these drugs. This commentary discusses scientific publications on the effects of statins on SPMs and the resolution of inflammation process.

Elevation of fatty acid desaturase 2 in esophageal adenocarcinoma increases polyunsaturated lipids and may exacerbate bile acid-induced DNA damage

Background

The risk of esophageal adenocarcinoma (EAC) is associated with gastro‐esophageal reflux disease (GERD) and obesity. Lipid metabolism‐targeted therapies decrease the risk of progressing from Barrett's esophagus (BE) to EAC, but the precise lipid metabolic changes and their roles in genotoxicity during EAC development are yet to be established.

Methods

Esophageal biopsies from the normal epithelium (NE), BE, and EAC, were analyzed using concurrent lipidomics and proteomics (n = 30) followed by orthogonal validation on independent samples using RNAseq transcriptomics (n = 22) and immunohistochemistry (IHC, n = 80). The EAC cell line FLO‐1 was treated with FADS2 selective inhibitor SC26196, and/or bile acid cocktail, followed by immunofluorescence staining for γH2AX.

Results

Metabolism‐focused Reactome analysis of the proteomics data revealed enrichment of fatty acid metabolism, ketone body metabolism, and biosynthesis of specialized pro‐resolving mediators in EAC pathogenesis. Lipidomics revealed progressive alterations (NE‐BE‐EAC) in glycerophospholipid synthesis with decreasing triglycerides and increasing phosphatidylcholine and phosphatidylethanolamine, and sphingolipid synthesis with decreasing dihydroceramide and increasing ceramides. Furthermore, a progressive increase in lipids with C20 fatty acids and polyunsaturated lipids with ≥4 double bonds were also observed. Integration with transcriptome data identified candidate enzymes for IHC validation: Δ4‐Desaturase, Sphingolipid 1 (DEGS1) which desaturates dihydroceramide to ceramide, and Δ5 and Δ6‐Desaturases (fatty acid desaturases, FADS1 and FADS2), responsible for polyunsaturation. All three enzymes showed significant increases from BE through dysplasia to EAC, but transcript levels of DEGS1 were decreased suggesting post‐translational regulation. Finally, the FADS2 selective inhibitor SC26196 significantly reduced polyunsaturated lipids with three and four double bonds and reduced bile acid‐induced DNA double‐strand breaks in FLO‐1 cells in vitro.

Conclusions

Integrated multiomics revealed sphingolipid and phospholipid metabolism rewiring during EAC development. FADS2 inhibition and reduction of the high polyunsaturated lipids effectively protected EAC cells from bile acid‐induced DNA damage in vitro, potentially through reduced lipid peroxidation.

Maresin1 is a predictive marker of new digital ulcers in systemic sclerosis patients

BACKGROUND

Digital ulcers (DUs) are one of the main causes of disability among systemic sclerosis (SSc) patients. The inflammation plays a crucial role in mediating the pathophysiological process underlying SSc. Objective of this study was to evaluate Maresin1 (MaR1) serum levels in SSc patients and in healthy controls (HC). Secondary aims were to evaluate the relationship between MaR and diseases variables and to assess the predictive role of MaR1 in the development of new digital ulcers (DUs) during 18 weeks follow-up.

METHODS

MaR1 serum level was evaluated in 55 SSc patients and 24 HC. In SSc patients, clinical assessment was performed at baseline and after 18 week follow-up by the same-blinded observer on serum MaR1 levels.

RESULTS

MaR1 was significantly lower in SSc patients than in HC [367 pg/ml (IQR 304-468.3 pg/ml) vs 467.7 pg/ml (IQR 422-522 pg/ml), p < 0.001]. During follow-up, six patients (10.9%) developed DUs. MaR1 was higher in SSc patients with new DUs than in patients without new DUs [518.2 pg/ml (IQR 468.2-596.5 pg/ml) vs 355 pg/ml (IQR 299.8-444.7 pg/ml), p < 0.01]. Free survival from new DUs is significantly lower in SSc patients with increased MaR1 serum level than in SSc patient with normal MaR1 serum level. In multivariate analysis, serum level of MaR1 > 393.2 pg/ml is a predictive marker for new DUs.

CONCLUSION

In SSc patients, MaR1 is reduced compared to HC and it is a predictive marker of new DUs.

Effect of naturally derived surgical hemostatic materials on the proliferation of A549 human lung adenocarcinoma cells

Hemostatic materials are generally applied in surgical operations for cancer, but their effects on the growth and recurrence of tumors are unclear. Herein, three commonly used naturally derived hemostatic materials, gelatin sponge, Surgicel (oxidized regenerated cellulose), and biopaper (mixture of sodium hyaluronate and carboxymethyl chitosan), were cocultured with A549 human lung adenocarcinoma cells in vitro. Furthermore, the performance of hemostatic materials and the tumorigenicity of the materials with A549 ​cells were observed after subcutaneous implantation into BALB/c mice. The in vitro results showed that biopaper was dissolved quickly, with the highest cell numbers at 2 and 4 days of culture. Gelatin sponges retained their structure and elicited the least cell infiltration during the 2- to 10-day culture. Surgicel partially dissolved and supported cell growth over time. The in vivo results showed that biopaper degraded rapidly and elicited an acute Th1 lymphocyte reaction at 3 days after implantation, which was decreased at 7 days after implantation. The gelatin sponge resisted degradation and evoked a hybrid M1/M2 macrophage reaction at 7–21 days after implantation, and a protumor M2d subset was confirmed. Surgicel resisted early degradation and caused obvious antitumor M2a macrophage reactions. Mice subjected to subcutaneous implantation of A549 ​cells and hemostatic materials in the gelatin sponge group had the largest tumor volumes and the shortest overall survival (OS), while the Surgicel and the biopaper group had the smallest volumes and the longest OS. Therefore, although gelatin sponges exhibited cytotoxicity to A549 ​cells in vitro, they promoted the growth of A549 ​cells in vivo, which was related to chronic M2d macrophage reaction. Surgicel and biopaper inhibited A549 ​cell growth in vivo, which is associated with chronic M2a macrophage reaction or acute Th1 lymphocyte reaction.

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The gelatin sponge, Surgicel and biopaper had different effects on A549 ​cell growth and proliferation.

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Biopaper degraded rapidly in vivo and elicited an antitumor Th1 lymphocyte reaction at acute inflammatory phase.

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The gelatin sponge resisted degradation and evoked a protumor M2d macrophage reactions.

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Surgicel resisted early degradation and caused obvious antitumor M2a macrophage reactions.

Tumor-Associated Macrophages: Key Players in Triple-Negative Breast Cancer

Triple negative breast cancer (TNBC) refers to the subtype of breast cancer which is negative for ER, PR, and HER-2 receptors. Tumor-associated macrophages (TAMs) refer to the leukocyte infiltrating tumor, derived from circulating blood mononuclear cells and differentiating into macrophages after exuding tissues. TAMs are divided into typical activated M1 subtype and alternately activated M2 subtype, which have different expressions of receptors, cytokines and chemokines. M1 is characterized by expressing a large amount of inducible nitric oxide synthase and TNF-α, and exert anti-tumor activity by promoting pro-inflammatory and immune responses. M2 usually expresses Arginase 1 and high levels of cytokines, growth factors and proteases to support their carcinogenic function. Recent studies demonstrate that TAMs participate in the process of TNBC from occurrence to metastasis, and might serve as potential biomarkers for prognosis prediction.

Pro-Resolving Factor Administration Limits Cancer Progression by Enhancing Immune Response Against Cancer Cells

Cancers are consequences of cellular dysfunction leading to an aberrant cellular multiplication and proliferation, subsequently yielding metastasis formation. Inflammatory reaction, with immune cell recruitment, is the main defense against precancerous lesions. However, an inflammatory environment also favors cancer cell progression, with cancer cell evasion from immune surveillance, leading to cancer development. Current therapeutic strategies enhance this natural immune response in order to restore immunosurveillance. The variety of these strategies is a predominant source of inflammatory mediators used by cancer cells to grow, differentiate, and migrate, therefore encouraging metastasis formation. For this reason, during cancer progression, limiting inflammation appears to be an innovative strategy to avoid the escape of cancer cells and potentially enhance the efficacy of antitumor therapies. Thus, this study aims to investigate the impact of administering pro-resolving factors (SuperMApo® drug candidate), which are inducers of inflammation resolution, in the framework of cancer treatment. We have observed that administering pro-resolving mediators issued from apoptotic cell efferocytosis by macrophages controlled peritoneal cancer progression by limiting cancer cell dissemination to the blood and mesenteric lymph nodes. This observation has been linked to an increase of macrophage mobilization in both peritoneal cavity and mesenteric lymph nodes. This control is associated to a restricted immunosuppressive myeloid cell circulation and to an IFN-γ-specific anti-tumor T-cell response. Altogether, these results suggest that administering proresolving factors could provide a new additional therapeutic alternative to control cancer progression.

Efficacy of ω-3 Polyunsaturated Fatty Acids in Patients with Lung Cancer Undergoing Radiotherapy and Chemotherapy: A Meta-Analysis

BACKGROUND

Radiotherapy and chemotherapy in patients with lung cancer can lead to a series of problems such as malnutrition and inflammatory reaction. Some studies have shown that ω-3 polyunsaturated fatty acids (PUFAs) could improve malnutrition and regulate inflammatory reaction in these patients, but no relevant meta-analysis exists.

METHODS

We systematically searched randomized controlled trials of ω-3 PUFAs in the adjuvant treatment of lung cancer in the PubMed, EMBASE, Cochrane Library, Web of Science, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), and Wanfang databases. Relevant outcomes were extracted, and we pooled standardized mean differences (SMDs) using a random or fixed-effects model. The risk of bias was evaluated according to the Cochrane Handbook (version 15.1). The quality of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

RESULTS

A total of 7 studies were included. The SMDs (95% CI) of body weight change, albumin change, energy intake, and protein intake at the end of intervention were 1.15 (0.50, 1.80), 0.60 (0.11, 1.09), 0.39 (-0.10, 0.89), and 0.27 (-0.04, 0.58), respectively. The SMDs (95% CI) of CRP change and TNF-α change were -3.44 (-6.15, -0.73) and -1.63 (-2.53, -0.73), respectively.

CONCLUSIONS

ω-3 PUFAs can improve nutritional status and regulate indicators of inflammation in patients with lung cancer undergoing radiotherapy and chemotherapy. This study was registered in the PROSPERO (registration number: CRD42022307699).

Long noncoding RNA SNHG4: a novel target in human diseases

Recently, long noncoding RNAs (lncRNAs) have attracted great attention from researchers. LncRNAs are non-protein-coding RNAs of more than 200 nucleotides in length. Multiple studies have been published on the relationship between lncRNA expression and the progression of human diseases. LncRNA small nucleolar RNA host gene 4 (SNHG4), a member of the lncRNA SNHG family, is abnormally expressed in a variety of human diseases, including gastric cancer, renal cell carcinoma, glioblastoma, neuroblastoma, prostate cancer, colorectal cancer, osteosarcoma, cervical cancer, liver cancer, lung cancer, non-small-cell lung cancer, neonatal pneumonia, diabetic retinopathy, neuropathic pain, acute cerebral infarction, acute myeloid leukaemia, and endometriosis. In this paper, the structure of SNHG4 is first introduced, and then studies in humans, animal models and cells are summarized to highlight the expression and function of SNHG4 in the above diseases. In addition, the specific mechanism of SNHG4 as a competing endogenous RNA (ceRNA) is discussed. The findings indicate that SNHG4 can be used as a biomarker for disease prognosis evaluation and as a potential target for disease diagnosis and treatment.

Debris-stimulated tumor growth: a Pandora's box?

Current cancer therapies aim at eradicating cancer cells from the body. However, killing cells generates cell “debris” which can promote tumor progression. Thus, therapy can be a double-edged sword. Specifically, injury and debris generated by cancer therapies, including chemotherapy, radiation, and surgery, may offset their benefit by promoting the secretion of pro-tumorigenic factors (e.g., eicosanoid-driven cytokines) that stimulate regrowth and metastasis of surviving cells. The debris produced by cytotoxic cancer therapy can also contribute to a tumor microenvironment that promotes tumor progression and recurrence. Although not well understood, several molecular mechanisms have been implicated in debris-stimulated tumor growth that we review here, such as the involvement of extracellular vesicles, exosomal miR-194-5p, Bax, Bak, Smac, HMGB1, cytokines, and caspase-3. We discuss the cases of pancreatic and other cancer types where debris promotes postoperative tumor recurrence and metastasis, thus offering a new opportunity to prevent cancer progression intrinsically linked to treatment by stimulating resolution of tumor-promoting debris.