Annexin A5 as an immune checkpoint inhibitor and tumor-homing molecule for cancer treatment

In situ vaccine "seeds" for enhancing cancer immunotherapy by exploiting apoptosis-associated morphological changes

Despite the development of many effective immunoadjuvants (IAs), the therapeutic efficacy of in situ vaccines for anti-tumor applications remains limited. Inspired by the morphological changes occurring during apoptosis, this study aims to leverage the release process of autologous tumor antigens (ATAs) to enhance the anti-tumor activity of in situ vaccines. We developed five distinct liposomes, each with unique characteristics and functions, incorporating FDA-approved monophosphoryl lipid A (MPLA) adjuvants into their lipid bilayers. Our findings revealed that the apoptotic bodies generated from tumor cells treated with membrane-fusion liposomes (MFLs) exhibited a greater capacity for immune activation. Mechanistic studies demonstrated that MFLs can utilize the morphological changes associated with apoptosis to accurately deliver adjuvants to apoptotic bodies. To further optimize the efficiency of antigen presentation by these apoptotic bodies as an adjuvant redistribution platform, we encapsulated a calcium chelator within the MFLs to inhibit the externalization of phosphatidylserine (PS) during apoptosis. Through a series of apoptosis-related cellular events, the vaccine can widely disseminate immunoadjuvants (IAs) within tumor tissues, similar to the dispersal of plant seeds. To the best of our knowledge, this is the first approach to utilize apoptosis-associated morphological changes to enhance the immunotherapeutic efficacy of cancer vaccines.

Copper Chelate Targeting Externalized Phosphatidylserine Inhibits PD-L1 Expression and Enhances Cancer Immunotherapy

Inhibitors of the PD-1/PD-L1 immune checkpoint have revolutionized cancer treatment. However, the clinical response remains limited, with only 20% of patients benefiting from treatment and approximately 60% of PD-L1-positive patients exhibiting resistance. One key factor contributing to resistance is the externalization of phosphatidylserine (PS) on the surface of cancer cells, which suppresses immune responses and promotes PD-L1 expression, further hindering the efficacy of PD-L1 blockade therapies. Here, we introduce a copper chelate composed of a terpyridine-Cu complex with a farnesol tail designed to selectively target and cap the externalized PS on cancer cells. This approach not only promotes dendritic cell maturation and effector T-cell proliferation and tumor infiltration but also significantly inhibits PD-L1 expression, thereby amplifying T-cell-mediated immune responses. Our results demonstrate that this strategy induces robust immunological memory and leads to the eradication of tumors in over 70% of mice with colorectal and melanoma cancers. These findings highlight a promising, antibody-independent strategy for cancer immunotherapy where targeting externalized PS could overcome current limitations of checkpoint blockade therapies.

ANXA5 predicts prognosis and immune response and mediates proliferation and migration in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a common malignancy that often develops unnoticed. Typically, these tumors are identified at advanced stages, resulting in a relatively low chance of successful treatment. Anoikis serves as a natural defense against the spread of tumor cells, meaning circumventing anoikis can effectively inhibit tumor metastasis. Nonetheless, studies focusing on anoikis in the context of HNSCC remain scarce.

METHODS

Anoikis-related genes (ARGs) were identified by using the GeneCards and Harmonizome databases. Expression data of these genes and relevant clinical features were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. A LASSO regression and a prognostic risk score model were developed to determine their prognostic significance. The analysis included the use of the CIBERSORT algorithm to quantify immune and stromal cell presence. Furthermore, in vitro and in vivo, we confirmed the expression and functional roles of proteins and mRNA of genes independently predictive of prognosis.

RESULTS

The study identified eight genes linked to prognosis (ANXA5, BAK1, CDKN2A, PPARG, CCR7, MAPK11, CRYAB, CRYBA1) and developed a prognostic model that effectively forecasts the survival outcomes for patients with HNSCC. A higher survival likelihood is associated with lower risk scores. In addition, a significant relationship was found between immune and risk score, and ANXA5 deletion promoted the killing of HNSCC cells by activated CD8+ T cells. During the screening process, 65 different chemotherapeutic drugs were found to have significant differences in IC50 values when comparing high- and low-risk categories. ANXA5 emerged as a gene with independent prognostic significance, exhibiting notably elevated protein and mRNA levels in HNSCC tissue compared to non-tumorous tissue. The suppression of ANXA5 gene activity resulted in a substantial decrease in both the growth and mobility of HNSCC cells. Animal model experiments demonstrated that inhibiting ANXA5 suppressed HNSCC growth and migration in vivo.

CONCLUSION

Through bioinformatics, a prognostic risk model of high precision was developed, offering valuable insights into the survival rates and immune responses in patients with HNSCC. ANXA5 is highlighted as a significant prognostic factor among the identified genes, indicating its promise as a potential therapeutic target for those with HNSCC.

Exploring Protein Functions of Gut Bacteriome and Mycobiome in Thai Infants Associated with Atopic Dermatitis Through Metaproteomic and Host Interaction Analysis

Atopic dermatitis (AD), a prevalent allergic skin condition in children, has been closely associated with imbalances in the gut microbiome. To investigate these microbial alterations and their functional implications, we investigated protein expression, functions and interactions of the gut bacteriome and mycobiome as well as the human proteome in Thai infants with AD using integrative metaproteomic and host interaction analysis. As we observed, probiotic species, such as Lactobacillus acidophilus and Bacteroides salyersiae, were reduced in abundance in the AD group while key pathogenic bacteria and fungi, such as Streptococcus constellatus and Penicillium chrysogenum, increased in abundance. Additionally, the functional analysis of expressed proteins was enriched in response to stress and DNA repair in the bacteriome and ribosome biogenesis-related processes in the mycobiome of the AD group, potentially associated to increased reactive oxygen species (ROS), intestinal inflammation, fungal growth and microbial dysbiosis. Further, a protein-protein interactions (PPIs) network analysis incorporating the human proteome revealed 10 signature proteins related to stress and immune system processes associated with AD. Our findings propose the interactions of the key species and signature protein functions between the gut microbes and the human host in response to AD in Thai infants. To our knowledge, this study serves as the first framework for monitoring bacteriome-mycobiome-human gut studies associated with AD and other allergic diseases in infants.

A Self-Cascading Catalytic Therapy and Antigen Capture Scaffold-Mediated T Cells Augments for Postoperative Brain Immunotherapy

The recruitment of T lymphocytes holds great potential for suppressing the most aggressive glioblastoma (GBM) recurrence with immunotherapy. However, the phenomenon of immune privilege and the generally low immunogenicity of vaccines often reduce the presence of lymphocytes within brain tumors, especially in brain tumor recurrence clusters. In this study, an implantable self-cascading catalytic therapy and antigen capture scaffold (CAS) that can boost catalytic therapy efficiency at post-surgery brain tumor and capture the antigens via urethane-polyethylene glycol-polypropylene glycol (PU-EO-PO) segments are developed for postoperative brain immunotherapy. The CAS consists of 3D-printed elastomers modified with iron (Fe2+) metal-organic frameworks (MOFs, MIL88) and acts as a programmed peroxide mimic in cancer cells to initiate the Fenton reaction and sustain ROS production. With the assistance of chloroquine (CQ), autophagy is inhibited through lysosome deacidification, which interrupts the self-defense mechanism, further enhances cytotoxicity, and releases antigens. Then, CAS containing PU-EO-PO groups acts as an antigen depot to detain autologous tumor-associated antigens to dendritic cells maturation and T cell augments for sustained immune stimulation. CAS enhanced the immune response to postoperative brain tumors and improved survival through brain immunotherapy.

A novel annexin dimer targets microglial phagocytosis of astrocytes to protect the brain-blood barrier after cerebral ischemia

Despite the vital role of astrocytes in preserving blood-brain barrier (BBB) integrity, their therapeutic potential as targets in ischemic stroke-induced barrier disruption remains underexplored. We previously reported externalization of phosphatidylserine (PS) on astrocytic membranes concurrent with the emergence of PS externalization in neurons. PS externalization of astrocytes induced microglial phagocytosis of astrocytes, resulting in reduced astrocyte-vascular coupling and subsequent BBB breakdown. Annexin A5 (ANXA5) belongs to the superfamily of calcium (Ca2+)- and phospholipid-binding proteins. Here, we report two X-ray structures of human ANXA5, including monomeric ANXA5 (1.42 Å) and dimeric ANXA5 (1.80 Å). Through the combination of molecular docking and functional analysis, we explored the mechanism of action of ANXA5 in stroke treatment. In addition, we observed a clear increase in therapeutic efficacy corresponding to the increased affinity of ANXA5 for PS. In summary, the phagocytosis of PS-externalized astrocytes by microglia has emerged as a critical mechanism driving BBB breakdown after ischemia. Our findings offer valuable structural insight into ANXA5 as an innovative pharmacological target for safeguarding blood-brain barrier integrity after cerebral ischemia. These insights may facilitate the development of novel PS-targeting medications aimed at achieving enhanced efficacy with minimal side effects.

Phosphatidylserine externalization as immune checkpoint in cancer

Cancer is the second leading cause of mortality worldwide. Despite recent advances in cancer treatment including immunotherapy with immune checkpoint inhibitors, new unconventional biomarkers and targets for the detection, prognosis, and treatment of cancer are still in high demand. Tumor cells are characterized by mutations that allow their unlimited growth, program their local microenvironment to support tumor growth, and spread towards distant sites. While a major focus has been on altered tumor genomes and proteomes, crucial signaling molecules such as lipids have been underappreciated. One of these molecules is the membrane phospholipid phosphatidylserine (PS) that is usually found at cytosolic surfaces of cellular membranes but can be rapidly and massively shuttled to the extracellular leaflet of the plasma membrane during apoptosis to serve as a limiting factor for immune responses. These immunosuppressive interactions are exploited by tumor cells to evade the immune system. In this review, we describe mechanisms of immune regulation in tumors, discuss if PS may constitute an inhibitory immune checkpoint, and describe current and future strategies for targeting PS to reactivate the tumor-associated immune system.

Identifying the key hub genes linked with lung squamous cell carcinoma by examining the differentially expressed and survival genes

Lung Squamous Cell Carcinoma is characterised by significant alterations in RNA expression patterns, and a lack of early symptoms and diagnosis results in poor survival rates. Our study aimed to identify the hub genes involved in LUSC by differential expression analysis and their influence on overall survival rates in patients. Thus, identifying genes with the potential to serve as biomarkers and therapeutic targets. RNA sequence data for LUSC was obtained from TCGA and analysed using R Studio. Survival analysis was performed on DE genes. PPI network and hub gene analysis was performed on survival-relevant genes. Enrichment analysis was conducted on the PPI network to elucidate the functional roles of hub genes. Our analysis identified 2774 DEGs in LUSC patient datasets. Survival analysis revealed 511 genes with a significant impact on patient survival. Among these, 20 hub genes-FN1, ACTB, HGF, PDGFRB, PTEN, SNAI1, TGFBR1, ESR1, SERPINE1, THBS1, PDGFRA, VWF, BMP2, LEP, VTN, PXN, ABL1, ITGA3 and ANXA5-were found to have lower expression levels associated with better patient survival, whereas high expression of SOX2 correlated with longer survival. Enrichment analysis indicated that these hub genes are involved in critical cellular and cancer-related pathways. Our study has identified six key hub genes that are differentially expressed and exhibit significant influence over LUSC patient survival outcomes. Further, in vitro and in vivo studies must be conducted on the key genes for their utilisation as therapeutic targets and biomarkers in LUSC.

Augmentation of hepatocellular carcinoma malignancy by annexin A5 through modulation of invasion and angiogenesis

BACKGROUND

Hepatocellular carcinoma (HCC) continues to play a substantial role in cancer-related morbidity and mortality, largely owing to its pronounced tumor heterogeneity and propensity for recurrence. This underscores the pressing need for in-depth examination of its highly malignant mechanisms. Annexin A5 (ANXA5), recognized as a hallmark tumor protein, has emerged as a focal point of interest because of its ambiguous function and mechanism in HCC prognosis. This study aimed to provide a comprehensive understanding of the role of ANXA5 in the malignant progression of human HCC cells by employing an integrative approach that combines conventional experimental methods with RNA sequencing.

METHODS

Differences in ANXA5 expression between HCC tissues and corresponding nontumor tissues were evaluated using immunofluorescence (n = 25). Correlation analysis was subsequently performed to assess the association between ANXA5 expression and clinicopathological features (n = 65). The role of ANXA5 in human HCC cell lines with ANXA5 gene knockout and overexpression was explored in vitro using migration and invasion assays and Ki-67 indices and in vivo based on node mice xenograft model. A tube formation assay using human umbilical vein endothelial cells (HUVECs) was conducted to demonstrate the angiogenic effects of ANXA5 in HCC. Single-cell and bulk RNA sequencing was used to further investigate the underlying mechanisms involved.

RESULTS

This study revealed that ANXA5 is highly expressed in patients with HCC and correlates with poor prognosis. Assays for migration, invasion, and proliferation based on ANXA5 gene knockout and overexpression systems in human HCC cell lines have demonstrated that ANXA5 enhances HCC malignancy in vitro and in vivo. Tube formation assays of HUVECs indicated that ANXA5 facilitates angiogenesis and recruits endothelial cells to HCC cells. Single-cell and bulk RNA sequencing data analysis further confirmed that ANXA5 expression in HCC is associated with hepatocyte metabolism, immune response activation, and various oncogenic signaling pathways.

CONCLUSIONS

This study revealed a meaningful association between elevated ANXA5 expression in tumor tissues and an unfavorable prognosis in patients with HCC. In addition, ANXA5 promotes HCC malignancy by promoting invasion and angiogenesis. Thus, ANXA5 has emerged as a promising therapeutic target for HCC and has the potential to improve patient outcomes.

New Therapeutic Strategies in Retinal Vascular Diseases: A Lipid Target, Phosphatidylserine, and Annexin A5-A Future Theranostic Pairing in Ophthalmology

Despite progress in the management of patients with retinal vascular and degenerative diseases, there is still an unmet clinical need for safe and effective therapeutic options with novel mechanisms of action. Recent mechanistic insights into the pathogenesis of retinal diseases with a prominent vascular component, such as retinal vein occlusion (RVO), diabetic retinopathy (DR) and wet age-related macular degeneration (AMD), may open up new treatment paradigms that reach beyond the inhibition of vascular endothelial growth factor (VEGF). Phosphatidylserine (PS) is a novel lipid target that is linked to the pathophysiology of several human diseases, including retinal diseases. PS acts upstream of VEGF and complement signaling pathways. Annexin A5 is a protein that targets PS and inhibits PS signaling. This review explores the current understanding of the potential roles of PS as a target and Annexin A5 as a therapeutic. The clinical development status of Annexin A5 as a therapeutic and the potential utility of PS-Annexin A5 as a theranostic pairing in retinal vascular conditions in particular is described.

Nanoplatform-Based In Vivo Gene Delivery Systems for Cancer Therapy

Gene therapy uses modern molecular biology methods to repair disease-causing genes. As a burgeoning therapeutic, it has been widely applied for cancer therapy. Since 1989, there have been numerous clinical gene therapy cases worldwide. However, a few are successful. The main challenge of clinical gene therapy is the lack of efficient and safe vectors. Although viral vectors show high transfection efficiency, their application is still limited by immune rejection and packaging capacity. Therefore, the development of non-viral vectors is overwhelming. Nanoplatform-based non-viral vectors become a hotspot in gene therapy. The reasons are mainly as follows. 1) Non-viral vectors can be engineered to be uptaken by specific types of cells or tissues, providing effective targeting capability. 2) Non-viral vectors can protect goods that need to be delivered from degradation. 3) Nanoparticles can transport large-sized cargo such as CRISPR/Cas9 plasmids and nucleoprotein complexes. 4) Nanoparticles are highly biosafe, and they are not mutagenic in themselves compared to viral vectors. 5) Nanoparticles are easy to scale preparation, which is conducive to clinical conversion and application. Here, an overview of the categories of nanoplatform-based non-viral gene vectors, the limitations on their development, and their applications in cancer therapy.

Enzyme-Instructed Photoactivatable Supramolecular Antigens on Cancer Cell Membranes for Precision-Controlled T-Cell-Based Cancer Immunotherapy

Cancer immunotherapies based on cytotoxic CD8+ T lymphocytes (CTLs) are highly promising for cancer treatment. The specific interaction between T-cell receptors and peptide-MHC-I complexes (pMHC-I) on cancer cell membranes critically determines their therapeutic outcomes. However, the lack of appropriate endogenous antigens for MHC-I presentation disables tumor recognition by CTLs. By devising three antigen-loaded self-assembling peptides of pY-K(Ag)-ERGD, pY-K(Ag)-E, and Y-K(Ag)-ERGD to noncovalently generate light-activatable supramolecular antigens at tumor sites in different manners, we report pY-K(Ag)-ERGD as a promising candidate to endow tumor cells with pMHC-I targets on demand. Specifically, pY-K(Ag)-ERGD first generates low-antigenic supramolecular antigens on cancer cell membranes, and a successive light pulse allows antigen payloads to efficiently release from the supramolecular scaffold, directly producing antigenic pMHC-I. Intravenous administration of pY-K(Ag)-ERGD enables light-controlled tumor inhibition when combined with adoptively transferred antigen-specific CTLs. Our strategy is feasible for broadening tumor antigen repertoires for T-cell immunotherapies and advancing precision-controlled T-cell immunotherapies.

ANXA5: A Key Regulator of Immune Cell Infiltration in Hepatocellular Carcinoma

BACKGROUND Hepatocellular carcinoma (HCC) poses a significant threat to human life and is the most prevalent form of liver cancer. The intricate interplay between apoptosis, a common form of programmed cell death, and its role in immune regulation stands as a crucial mechanism influencing tumor metastasis. MATERIAL AND METHODS Utilizing HCC samples from the TCGA database and 61 anoikis-related genes (ARGs) sourced from GeneCards, we analyzed the relationship between ARGs and immune cell infiltration in HCC. Subsequently, we identified long non-coding RNAs (lncRNAs) associated with ARGs, using the least absolute shrinkage and selection operator (LASSO) regression analysis to construct a robust prognostic model. The predictive capabilities of the model were then validated through examination in a single-cell dataset. RESULTS Our constructed prognostic model, derived from lncRNAs linked to ARGs, comprised 11 significant lncRNAs: NRAV, MCM3AP-AS1, OTUD6B-AS1, AC026356.1, AC009133.1, DDX11-AS1, AC108463.2, MIR4435-2HG, WARS2-AS1, LINC01094, and HCG18. The risk score assigned to HCC samples demonstrated associations with immune indicators and the infiltration of immune cells. Further, we identified Annexin A5 (ANXA5) as the pivotal gene among ARGs, with it exerting a prominent role in regulating the lncRNA gene signature. Our validation in a single-cell database elucidated the involvement of ANXA5 in immune cell infiltration, specifically in the regulation of mononuclear cells. CONCLUSIONS This study delves into the intricate correlation between ARGs and immune cell infiltration in HCC, culminating in the development of a novel prognostic model reliant on 11 ARGs-associated lncRNAs. Furthermore, our findings highlight ANXA5 as a promising target for immune regulation in HCC, offering new perspectives for immune therapy in the context of HCC.

Insights into membrane interactions and their therapeutic potential

Recent research into membrane interactions has uncovered a diverse range of therapeutic opportunities through the bioengineering of human and non-human macromolecules. Although the majority of this research is focussed on fundamental developments, emerging studies are showcasing promising new technologies to combat conditions such as cancer, Alzheimer's and inflammatory and immune-based disease, utilising the alteration of bacteriophage, adenovirus, bacterial toxins, type 6 secretion systems, annexins, mitochondrial antiviral signalling proteins and bacterial nano-syringes. To advance the field further, each of these opportunities need to be better understood, and the therapeutic models need to be further optimised. Here, we summarise the knowledge and insights into several membrane interactions and detail their current and potential uses therapeutically.

Cellular Components Contributing to the Development of Venous Thrombosis in Patients with Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive type of cancer and has a poor prognosis. Patients with PDAC are at high risk of developing thromboembolic events, which is a leading cause of morbidity and mortality following cancer progression. Plasma-derived coagulation is the most studied process in cancer-associated thrombosis. Other blood components, such as platelets, red blood cells, and white blood cells, have been gaining less attention. This narrative review addresses the literature on the role of cellular components in the development of venous thromboembolism (VTE) in patients with PDAC. Blood cells seem to play an important role in the development of VTE. Altered blood cell counts, i.e., leukocytosis, thrombocytosis, and anemia, have been found to associate with VTE risk. Tumor-related activation of leukocytes leads to the release of tissue factor-expressing microvesicles and the formation of neutrophil extracellular traps, initiating coagulation and forming a scaffold for thrombi. Tissue factor-expressing microvesicles are also thought to be released by PDAC cells. PDAC cells have been shown to stimulate platelet activation and aggregation, proposedly via the secretion of podoplanin and mucins. Hypofibrinolysis, partially explained by increased plasminogen activator inhibitor-1 activity, is observed in PDAC. In short, PDAC-associated hypercoagulability is a complex and multifactorial process. A better understanding of cellular contributions to hypercoagulability might lead to the improvement of diagnostic tests to identify PDAC patients at highest risk of VTE.

The Relevance, Predictability, and Utility of Annexin A5 for Human Physiopathology

As an important functional protein molecule in the human body, human annexin A5 (hAnxA5) is widely found in human cells and body fluids. hAnxA5, the smallest type of annexin, performs a variety of biological functions by reversibly and specifically binding phosphatidylserine (PS) in a calcium-dependent manner and plays an important role in many human physiological and pathological processes. The free state hAnxA5 exists in the form of monomers and usually forms a polymer in a specific self-assembly manner when exerting biological activity. This review systematically discusses the current knowledge and understanding of hAnxA5 from three perspectives: physiopathological relevance, diagnostic value, and therapeutic utility. hAnxA5 affects the occurrence and development of many physiopathological processes. Moreover, hAnxA5 can be used independently or in combination as a biomarker of physiopathological phenomena for the diagnosis of certain diseases. Importantly, based on the properties of hAnxA5, many novel drug candidates have been designed and prepared for application in actual medical practice. However, there are also some gaps and shortcomings in hAnxA5 research. This in-depth study will not only expand the understanding of structural and functional relationships but also promote the application of hAnxA5 in the field of biomedicine.

The macrophage-associated prognostic gene ANXA5 promotes immunotherapy resistance in gastric cancer through angiogenesis

Gastric cancer (GC) remains a predominant form of malignant tumor globally, necessitating innovative non-surgical therapeutic approaches. This investigation aimed to delineate the expression landscape of macrophage-associated genes in GC and to evaluate their prognostic significance and influence on immunotherapeutic responsiveness. Utilizing the CellMarker2.0 database, we identified 69 immune cell markers with prognostic relevance in GC, including 12 macrophage-specific genes. A Weighted Gene Co-Expression Network Analysis (WGCNA) isolated 3,181 genes correlated with these macrophage markers. The Cancer Genome Atlas (TCGA-STAD) dataset was employed as the training set, while data from the GSE62254 served as the validation cohort. 13 genes were shortlisted through LASSO-Cox regression to formulate a prognostic model. Multivariable Cox regression substantiated that the calculated risk score serves as an imperative independent predictor of overall survival (OS). Distinct macrophage infiltration profiles, pathway associations, treatment susceptibilities, and drug sensitivities were observed between high- and low-risk groups. The preliminary validation of ANXA5 in predicting the survival rates of GC patients at 1 year, 3 years, and 5 years, as well as its expression levels were higher and role in promoting tumor angiogenesis in GC through immunohistochemistry and angiogenesis experiments. In summary, macrophage-related genes were potentially a novel crosstalk mechanism between macrophages and endothelial cells in the tumor microenvironment, and the interplay between inflammation and angiogenesis might have also offered new therapeutic targets, providing a new avenue for personalized treatment interventions.

Annexin A5 derived from matrix vesicles protects against osteoporotic bone loss via mineralization

Matrix vesicles (MVs) have shown strong effects in diseases such as vascular ectopic calcification and pathological calcified osteoarthritis and in wound repair of the skeletal system due to their membranous vesicle characteristics and abundant calcium and phosphorus content. However, the role of MVs in the progression of osteoporosis is poorly understood. Here, we report that annexin A5, an important component of the matrix vesicle membrane, plays a vital role in bone matrix homeostasis in the deterioration of osteoporosis. We first identified annexin A5 from adherent MVs but not dissociative MVs of osteoblasts and found that it could be sharply decreased in the bone matrix during the occurrence of osteoporosis based on ovariectomized mice. We then confirmed its potential in mediating the mineralization of the precursor osteoblast lineage via its initial binding with collagen type I to achieve MV adhesion and the subsequent activation of cellular autophagy. Finally, we proved its protective role in resisting bone loss by applying it to osteoporotic mice. Taken together, these data revealed the importance of annexin A5, originating from adherent MVs of osteoblasts, in bone matrix remodeling of osteoporosis and provided a new strategy for the treatment and intervention of bone loss.

Lecithin Reverse Micelle System is Promising in Constructing Carrier Particles for Protein Drugs Encapsulated Pressurized Metered‐Dose Inhalers

Protein drugs contained within pressurized metered dose inhalers (pMDIs) show immense potential for fundamental research and industrial applications, owing to their high bioavailability, convenient administration, and cost‐effectiveness. To deliver protein drugs efficiently, researchers have reached a consensus on the use of carrier particles. However, the main obstacle impeding the commercial availability of pMDI carrier particles is their low stability. This instability is primarily attributed to particle aggregation caused by the Ostwald ripening phenomenon and chemical degradation by water sensitivity of protein drugs. This study proposes the utilization of lecithin, a carrier material possessing an amphiphilic structure, to overcome this bottleneck. By constructing lecithin‐based reverse micelle systems with protein drugs encapsulated within the high‐polarity microdomain, this work anticipates an improvement in the stability of carrier particles within pMDIs. Specifically, the formation of crystalline phases in the reverse micelle systems can control carrier particle size through crystalline self‐limiting effect, preventing particle aggregation. Additionally, the low‐polarity microdomain of the carrier serves as a hydrophobic barrier, shielding protein drugs from water and preventing chemical degradation. Consequently, this work believes that the lecithin‐based reverse micelle system holds significant potential in providing new theoretical insights and experimental support for the advancement of pMDIs containing protein drugs.

Efferocytosis Nanoinhibitors to Promote Secondary Necrosis and Potentiate the Immunogenicity of Conventional Cancer Therapies for Improved Therapeutic Benefits

Efferocytosis of apoptotic cancer cells by tumor-associated macrophages or other phagocytes is reported to promote tumor immunosuppression by preventing them from secondary necrosis, which would lead to the release of intracellular components and thus enhanced immunogenicity. Therefore, current apoptosis-inducing cancer treatments (e.g., chemotherapy and radiotherapy) are less satisfactory in eliciting antitumor immunity. Herein, a nanoparticulate inhibitor of efferocytosis is prepared by encapsulating BMS777607, a hydrophobic inhibitor of receptors in macrophages responsible for phosphatidylserine-dependent efferocytosis, with biocompatible poly(lactic-co-glycolic acid) and its amphiphilic derivatives. The yielded nano-BMS can inhibit the efferocytosis of apoptotic cancer cells, thus redirecting them to immunogenic secondary necrosis. As a result, intratumorally injected nano-BMS is capable of activating both innate and adaptive antitumor immunity to achieve greatly improved therapeutic responses, when synergized with nonimmunogenic chemotherapy by cisplatin, immunogenic chemotherapy by oxaliplatin, or radiotherapy by external beams. Moreover, we further demonstrate that the inhalation of nano-BMS could significantly promote the efficacy of cisplatin chemotherapy to suppress tumor lung metastases. Therefore, this study highlights a general strategy to potentiate the immunogenicity of different cancer treatments by suppressing efferocytosis-propelled tumor immunosuppression, showing tremendous clinical potential in rescuing existing cancer therapies for more effective treatment.

Development of a prognostic model for anoikis and identifies hub genes in hepatocellular carcinoma

Considering the high fatality of hepatocellular carcinoma (HCC), current prognostic systems are insufficient to accurately forecast HCC patients' outcomes. In our study, nine anoikis‑related genes (PTRH2, ITGAV, ANXA5, BIRC5, BDNF, BSG, DAP3, SKP2, and EGF) were determined to establish a risk scoring model using LASSO regression, which could be validated in ICGC dataset. Kaplan-Meier curves and time-dependent receiver operating characteristic (ROC) curve analysis confirmed the risk score possessed an accurate predictive value for the prognosis of HCC patients. The high-risk group showed a higher infiltration of aDCs, macrophages, T-follicular helper cells, and Th2 cells. Besides, PD-L1 was significantly higher in the high-risk group compared to the low-risk group. Several anoikis‑related genes, such as ANX5, ITGAV, BDNF and SKP2, were associated with drug sensitivity in HCC. Finally, we identified BIRC5 and SKP2 as hub genes among the nine model genes using WGCNA analysis. BIRC5 and SKP2 were over-expressed in HCC tissues, and their over-expression was associated with poor prognosis, no matter in our cohort by immunohistochemical staining or in the TCGA cohort by mRNA-Seq. In our cohort, BIRC5 expression was highly associated with the T stage, pathologic stage, histologic grade and AFP of HCC patients. In general, our anoikis-related risk model can enhance the ability to predict the survival outcomes of HCC patients and provide a feasible therapeutic strategy for immunotherapy and drug resistance in HCC. BIRC5 and SKP2 are hub genes of anoikis‑related genes in HCC.

AnnexinA6: a potential therapeutic target gene for extracellular matrix mineralization

The mineralization of the extracellular matrix (ECM) is an essential and crucial process for physiological bone formation and pathological calcification. The abnormal function of ECM mineralization contributes to the worldwide risk of developing mineralization-related diseases; for instance, vascular calcification is attributed to the hyperfunction of ECM mineralization, while osteoporosis is due to hypofunction. AnnexinA6 (AnxA6), a Ca2+-dependent phospholipid-binding protein, has been extensively reported as an essential target in mineralization-related diseases such as osteoporosis, osteoarthritis, atherosclerosis, osteosarcoma, and calcific aortic valve disease. To date, AnxA6, as the largest member of the Annexin family, has attracted much attention due to its significant contribution to matrix vesicles (MVs) production and release, MVs-ECM interaction, cytoplasmic Ca2+ influx, and maturation of hydroxyapatite, making it an essential target in ECM mineralization. In this review, we outlined the recent advancements in the role of AnxA6 in mineralization-related diseases and the potential mechanisms of AnxA6 under normal and mineralization-related pathological conditions. AnxA6 could promote ECM mineralization for bone regeneration in the manner described previously. Therefore, AnxA6 may be a potential osteogenic target for ECM mineralization.

Design, Synthesis and Anti-Melanoma Activity of Novel Annexin V Derivative with β3-Integrin Affinity

Tumor tissues often exhibit unique integrin receptor presentation during development, such as high exposures of α_vβ₃ and α_IIbβ₃ integrins. These features are not present in normal tissues. The induction of selective thrombosis and infarction in the tumor-feeding vessels, as well as specific antagonism of α_vβ₃ integrin on the surface of tumor endothelial cells, is a potential novel antitumor strategy. The Echistatin-Annexin V (EAV) fusion protein is a novel Annexin V (ANV) derivative that possesses a high degree of α_vβ₃ and α_IIbβ₃ integrin receptor recognition and binding characteristics while retaining the specific binding ability of the natural ANV molecule for phosphatidylserine (PS). We systematically investigated the biological effects of this novel molecule with superimposed functions on mouse melanoma. We found that EAV inhibited the viability and migration of B16F10 murine melanoma cells in a dose-dependent manner, exhibited good tumor suppressive effects in a xenograft mouse melanoma model, strongly induced tumor tissue necrosis in mice, and targeted the inhibition of angiogenesis in mouse melanoma tumor tissue. EAV exhibited stronger biological effects than natural ANV molecules in inhibiting melanoma in mice. The unique biological effects of EAV are based on its high β₃-type integrin receptor-specific recognition and binding ability, as well as its highly selective binding to PS molecules. Based on these findings, we propose that EAV-mediated tumor suppression is a novel and promising antitumor strategy that targets both PS- and integrin β₃-positive tumor neovascularization and the tumor cells themselves, thus providing a possible mechanism for the treatment of melanoma.

Novel pharmaceuticals for the management of retinal vein occlusion and linked disorders

INTRODUCTION

Retinal vein occlusion (RVO) is the second leading cause of blindness from retinal vascular disease behind diabetic retinopathy. Anti-vascular endothelial growth factor (VEGF) and glucocorticoid therapy are the cornerstones of pharmaceutical treatment for RVO. There is considerable interest in developing new pharmaceuticals in and out of these two classes to reduce costs, lower injection burden, and treat the occlusion itself, rather than the complications.

AREAS COVERED

In this review, we discuss novel pharmaceuticals for the treatment of RVO outside of current standard of care. We performed a comprehensive literature search encompassing pharmaceuticals that have recently been approved or have shown promising results in early clinical trials or animal models.

EXPERT OPINION

Anti-VEGF therapy remains the most efficacious treatment for RVO with a very favorable side effect profile. New biosimilars reduce costs while maintaining efficacy. Novel glucocorticoids may be a useful therapy in patients for whom anti-VEGF therapy has failed, or as an adjunct. Pharmaceuticals in other drug classes, particularly those with neuroprotective or regenerative properties, as well as those geared toward treating the occlusion itself, represent exciting options for early RVO therapy, but are likely years away from clinical relevance.

Phosphatidylserine-Exposing Annexin A1-Positive Extracellular Vesicles: Potential Cancer Biomarkers

Under physiological conditions, phosphatidylserine (PS) predominantly localizes to the cytosolic leaflet of the plasma membrane of cells. During apoptosis, PS is exposed on the cell surface and serves as an "eat-me" signal for macrophages to prevent releasing self-immunogenic cellular components from dying cells which could potentially lead to autoimmunity. However, increasing evidence indicates that viable cells can also expose PS on their surface. Interestingly, tumor cell-derived extracellular vesicles (EVs) externalize PS. Recent studies have proposed PS-exposing EVs as a potential biomarker for the early detection of cancer and other diseases. However, there are confounding results regarding subtypes of PS-positive EVs, and knowledge of PS exposure on the EV surface requires further elucidation. In this study, we enriched small EVs (sEVs) and medium/large EVs (m/lEVs) from conditioned media of breast cancer cells (MDA-MB-231, MDA-MB-468) and non-cancerous cells (keratinocytes, fibroblasts). Since several PS-binding molecules are available to date, we compared recombinant proteins of annexin A5 and the carboxylated glutamic acid domain of Protein S (GlaS), also specific for PS, to detect PS-exposing EVs. Firstly, PS externalization in each EV fraction was analyzed using a bead-based EV assay, which combines EV capture using microbeads and analysis of PS-exposing EVs by flow cytometry. The bulk EV assay showed higher PS externalization in m/lEVs derived from MDA-MB-468 cells but not from MDA-MB-231 cells, while higher binding of GlaS was also observed in m/lEVs from fibroblasts. Second, using single EV flow cytometry, PS externalization was also analyzed on individual sEVs and m/lEVs. Significantly higher PS externalization was detected in m/lEVs (annexin A1+) derived from cancer cells compared to m/lEVs (annexin A1+) from non-cancerous cells. These results emphasize the significance of PS-exposing m/lEVs (annexin A1+) as an undervalued EV subtype for early cancer detection and provide a better understanding of PS externalization in disease-associated EV subtypes.

Integrin Targeting Enhances the Antimelanoma Effect of Annexin V in Mice

Malignant melanoma, an increasingly common form of skin cancer, is a major threat to public health, especially when the disease progresses past skin lesions to the stage of advanced metastasis. Targeted drug development is an effective strategy for the treatment of malignant melanoma. In this work, a new antimelanoma tumor peptide, the lebestatin-annexin V (designated LbtA5) fusion protein, was developed and synthesized by recombinant DNA techniques. As a control, annexin V (designated ANV) was also synthesized by the same method. The fusion protein combines annexin V, which specifically recognizes and binds phosphatidylserine, with the disintegrin lebestatin (lbt), a polypeptide that specifically recognizes and binds integrin α1β1. LbtA5 was successfully prepared with good stability and high purity while retaining the dual biological activity of ANV and lbt. MTT assays demonstrated that both ANV and LbtA5 could reduce the viability of melanoma B16F10 cells, but the activity of the fusion protein LbtA5 was superior to that of ANV. The tumor volume growth was slowed in a mouse xenograft model treated with ANV and LbtA5, and the inhibitory effect of high concentrations of LbtA5 was significantly better than that of the same dose of ANV and was comparable to that of DTIC, a drug used clinically for melanoma treatment. The hematoxylin and eosin (H&E) staining test showed that ANV and LbtA5 had antitumor effects, but LbtA5 showed a stronger ability to induce melanoma necrosis in mice. Immunohistochemical experiments further showed that ANV and LbtA5 may inhibit tumor growth by inhibiting angiogenesis in tumor tissue. Fluorescence labeling experiments showed that the fusion of ANV with lbt enhanced the targeting of LbtA5 to mouse melanoma tumor tissue, and the amount of target protein in tumor tissue was significantly increased. In conclusion, effective coupling of the integrin α1β1-specific recognition molecule lbt confers stronger biological antimelanoma effects of ANV, which may be achieved by the dual effects of effective inhibition of B16F10 melanoma cell viability and inhibition of tumor tissue angiogenesis. The present study describes a new potential strategy for the application of the promising recombinant fusion protein LbtA5 in the treatment of various cancers, including malignant melanoma.

Phosphatidylserine in the Nervous System: Cytoplasmic Regulator of the AKT and PKC Signaling Pathways and Extracellular "Eat-Me" Signal in Microglial Phagocytosis

Phosphatidylserine (PtdSer) is an important anionic phospholipid found in eukaryotic cells and has been proven to serve as a beneficial factor in the treatment of neurodegenerative diseases. PtdSer resides in the inner leaflet of the plasma membrane, where it is involved in regulating the AKT and PKC signaling pathways; however, it becomes exposed to the extracellular leaflet during neurodevelopmental processes and neurodegenerative diseases, participating in microglia-mediated synaptic and neuronal phagocytosis. In this paper, we review several characteristics of PtdSer, including the synthesis and translocation of PtdSer, the functions of cytoplasmic and exposed PtdSer, and different PtdSer-detection materials used to further understand the role of PtdSer in the nervous system.

Targeting Xkr8 via nanoparticle-mediated in situ co-delivery of siRNA and chemotherapy drugs for cancer immunochemotherapy

Activation of scramblases is one of the mechanisms that regulates the exposure of phosphatidylserine to the cell surface, a process that plays an important role in tumour immunosuppression. Here we show that chemotherapeutic agents induce overexpression of Xkr8, a scramblase activated during apoptosis, at the transcriptional level in cancer cells, both in vitro and in vivo. Based on this finding, we developed a nanocarrier for co-delivery of Xkr8 short interfering RNA and the FuOXP prodrug to tumours. Intravenous injection of our nanocarrier led to significant inhibition of tumour growth in colon and pancreatic cancer models along with increased antitumour immune response. Targeting Xkr8 in combination with chemotherapy may represent a novel strategy for the treatment of various types of cancers.

Meta-Analysis of MS-Based Proteomics Studies Indicates Interferon Regulatory Factor 4 and Nucleobindin1 as Potential Prognostic and Drug Resistance Biomarkers in Diffuse Large B Cell Lymphoma

The prognosis of diffuse large B cell lymphoma (DLBCL) is inaccurately predicted using clinical features and immunohistochemistry (IHC) algorithms. Nomination of a panel of molecules as the target for therapy and predicting prognosis in DLBCL is challenging because of the divergences in the results of molecular studies. Mass spectrometry (MS)-based proteomics in the clinic represents an analytical tool with the potential to improve DLBCL diagnosis and prognosis. Previous proteomics studies using MS-based proteomics identified a wide range of proteins. To achieve a consensus, we reviewed MS-based proteomics studies and extracted the most consistently significantly dysregulated proteins. These proteins were then further explored by analyzing data from other omics fields. Among all significantly regulated proteins, interferon regulatory factor 4 (IRF4) was identified as a potential target by proteomics, genomics, and IHC. Moreover, annexinA5 (ANXA5) and nucleobindin1 (NUCB1) were two of the most up-regulated proteins identified in MS studies. Functional enrichment analysis identified the light zone reactions of the germinal center (LZ-GC) together with cytoskeleton locomotion functions as enriched based on consistent, significantly dysregulated proteins. In this study, we suggest IRF4 and NUCB1 proteins as potential biomarkers that deserve further investigation in the field of DLBCL sub-classification and prognosis.

Locoregional Lymphatic Delivery Systems Using Nanoparticles and Hydrogels for Anticancer Immunotherapy

The lymphatic system has gained significant interest as a target tissue to control cancer progress, which highlights its central role in adaptive immune response. Numerous mechanistic studies have revealed the benefits of nano-sized materials in the transport of various cargos to lymph nodes, overcoming barriers associated with lymphatic physiology. The potential of sustained drug delivery systems in improving the therapeutic index of various immune modulating agents is also being actively discussed. Herein, we aim to discuss design rationales and principles of locoregional lymphatic drug delivery systems for invigorating adaptive immune response for efficient antitumor immunotherapy and provide examples of various advanced nanoparticle- and hydrogel-based formulations.

Integrative proteomics and m6A microarray analyses of the signatures induced by METTL3 reveals prognostically significant in gastric cancer by affecting cellular metabolism

METTL3-mediated RNA N6-methyladenosine (m6A) is the most prevalent modification that participates in tumor initiation and progression via governing the expression of their target genes in cancers. However, its role in tumor cell metabolism remains poorly characterized. In this study, m6A microarray and quantitative proteomics were employed to explore the potential effect and mechanism of METTL3 on the metabolism in GC cells. Our results showed that METTL3 induced significant alterations in the protein and m6A modification profile in GC cells. Gene Ontology (GO) enrichment indicated that down-regulated proteins were significantly enriched in intracellular mitochondrial oxidative phosphorylation (OXPHOS). Moreover, the protein-protein Interaction (PPI) network analysis found that these differentially expressed proteins were significantly associated with OXPHOS. A prognostic model was subsequently constructed based on the Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases, and the high-risk group exhibited a worse prognosis in GC patients. Meanwhile, Gene Set Enrichment Analysis (GSEA) demonstrated significant enrichment in the energy metabolism signaling pathway. Then, combined with the results of the m6A microarray analysis, the intersection molecules of DEPs and differential methylation genes (DMGs) were significantly correlated with the molecules of OXPHOS. Besides, there were significant differences in prognosis and GSEA enrichment between the two clusters of GC patients classified according to the consensus clustering algorithm. Finally, highly expressed and highly methylated molecules regulated by METTL3 were analyzed and three (AVEN, DAZAP2, DNAJB1) genes were identified to be significantly associated with poor prognosis in GC patients. These results signified that METTL3-regulated DEPs in GC cells were significantly associated with OXPHOS. After combined with m6A microarray analysis, the results suggested that these proteins might be implicated in cell energy metabolism through m6A modifications thus influencing the prognosis of GC patients. Overall, our study revealed that METTL3 is involved in cell metabolism through an m6A-dependent mechanism in GC cells, and indicated a potential biomarker for prognostic prediction in GC.

Research progress on the circRNA/lncRNA-miRNA-mRNA axis in gastric cancer

Gastric cancer is one of the most common malignant tumours worldwide. Genetic and epigenetic alterations are key factors in gastric carcinogenesis and drug resistance to chemotherapy. Competing endogenous RNA (ceRNA) regulation models have defined circRNA/lncRNA as miRNA sponges that indirectly regulate miRNA downstream target genes. The ceRNA regulatory network is related to the malignant biological behaviour of gastric cancer. The circRNA/lncRNA-miRNA-mRNA axis may be a marker for the early diagnosis and prognosis of gastric cancer and a potential therapeutic target for gastric cancer. Exosomal ncRNAs play an important role in gastric cancer and are expected to be ideal biomarkers for the diagnosis, prognosis, and treatment of gastric cancer. This review summarizes the specific ceRNA regulatory network (circRNA/lncRNA-miRNA-mRNA) discovered in gastric cancer in recent years, which may provide new ideas or strategies for early clinical diagnosis, further development, and application.

Pathobiological functions and clinical implications of annexin dysregulation in human cancers

Annexins are an extensive superfamily of structurally related calcium- and phospholipid-binding proteins, largely conserved and widely distributed among species. Twelve human annexins have been identified, referred to as Annexin A1-13 (A12 remains as of yet unassigned), whose genes are spread throughout the genome on eight different chromosomes. According to their distinct tissue distribution and subcellular localization, annexins have been functionally implicated in a variety of biological processes relevant to both physiological and pathological conditions. Dysregulation of annexin expression patterns and functions has been revealed as a common feature in multiple cancers, thereby emerging as potential biomarkers and molecular targets for clinical application. Nevertheless, translation of this knowledge to the clinic requires in-depth functional and mechanistic characterization of dysregulated annexins for each individual cancer type, since each protein exhibits varying expression levels and phenotypic specificity depending on the tumor types. This review specifically and thoroughly examines the current knowledge on annexin dysfunctions in carcinogenesis. Hence, available data on expression levels, mechanism of action and pathophysiological effects of Annexin A1-13 among different cancers will be dissected, also further discussing future perspectives for potential applications as biomarkers for early diagnosis, prognosis and molecular-targeted therapies. Special attention is devoted to head and neck cancers (HNC), a complex and heterogeneous group of aggressive malignancies, often lately diagnosed, with high mortality, and scarce therapeutic options.

Cytotoxicity of polymers intended for the extrusion-based additive manufacturing of surgical guides

Extrusion-based printing enables simplified and economic manufacturing of surgical guides for oral implant placement. Therefore, the cytotoxicity of a biocopolyester (BE) and a polypropylene (PP), intended for the fused filament fabrication of surgical guides was evaluated. For comparison, a medically certified resin based on methacrylic esters (ME) was printed by stereolithography (n = 18 each group). Human gingival keratinocytes (HGK) were exposed to eluates of the tested materials and an impedance measurement and a tetrazolium assay (MTT) were performed. Modulations in gene expression were analyzed by quantitative PCR. One-way ANOVA with post-hoc Tukey tests were applied. None of the materials exceeded the threshold for cytotoxicity (< 70% viability in MTT) according to ISO 10993-5:2009. The impedance-based cell indices for PP and BE, reflecting cell proliferation, showed little deviations from the control, while ME caused a reduction of up to 45% after 72 h. PCR analysis after 72 h revealed only marginal modulations caused by BE while PP induced a down-regulation of genes encoding for inflammation and apoptosis (p < 0.05). In contrast, the 72 h ME eluate caused an up-regulation of these genes (p < 0.01). All evaluated materials can be considered biocompatible in vitro for short-term application. However, long-term contact to ME might induce (pro-)apoptotic/(pro-)inflammatory responses in HGK.

The role of microvesicles as biomarkers in the screening of colorectal neoplasm

Background

Colorectal cancer (CRC) is the second cause of cancer death worldwide. The role of circulating microvesicles as a screening tool is a novel, yet effective approach that warrants prioritised research.

Methods

In a two‐gate diagnostic accuracy study, 35 patients with benign colorectal polyps (BCRP) (n = 16) and colorectal cancer (CRC) (n = 19) were compared to 17 age‐matched healthy controls. Total annexin‐V positive microvesicles and sub‐populations positive for selected biomarkers relevant to bowel neoplasm were evaluated in patients' plasma using flow cytometry. Statistical methods including factor analysis utilising two component factors were performed to obtain optimal diagnostic accuracy of microvesicles in identifying patients with colorectal neoplasms.

Results

Total plasma microvesicles, and sub‐populations positive for CD31, CD42a, CD31+/CD42a‐, EPHB2, ICAM and LGR5 (component factor‐1) were able to identify patients with BCRP and CRC with a receiver operator curve (AUC) accuracy of a 100% (95% CI: 100%–100%) and 95% (95% CI: 88%–100%), respectively. To identify patients with BCRP, a cut‐off point value of component factor‐1761 microvesicles/μl demonstrated a 100% sensitivity, specificity and negative predictive value (NPV) and a 93% positive predictive value (PPV). To identify patients with CRC, a cut‐off value of component factor‐1 ³439 microvesicles/μl demonstrated a 100% sensitivity, specificity and NPV and a 65% PPV. CEA+ microvesicles sub‐population were significantly (p < 0.02) higher in CRC in comparison to BCRP.

Conclusions

Microvesicles as biomarkers for the early and accurate detection of CRC is a simple and effective tool that yields a potential breakthrough in clinical management.

Control of Tumors by Antigen-Specific CD8+ T Cells through PDL1-Targeted Delivery of Antigenic Peptide

Tumor antigen-specific T cell function is limited by immune tolerance in the tumor microenvironment. In the tumor microenvironment, tumor cells upregulate PD-L1 expression to promote T cell exhaustion by PD-1/PD-L1 interactions and undergo mutations to avoid being targeted by tumor antigen-specific T cells. Thus, tumor cells escape the immune surveillance by causing immune tolerance. We reason that a chimeric molecule made of a PD-L1-specific antibody linked to a cleavable antigenic peptide can target the antigenic peptide to the tumor microenvironment, resulting in the blockade of the PD-1/PD-L1 pathway and killing tumor cells through the coating of antigenic peptide. Here, we have generated a therapeutic chimeric protein containing the PD-L1 single-chain variable fragment (scFv) linked to a cleavable model cytotoxic T lymphocyte (CTL) epitope: E7 CTL peptide. Our study demonstrated that our chimeric protein (named PDL1-scFv-Fc-RE7) can target PD-L1-expressing tumor cells and enable E7 presentation by releasing cleavable E7 CTL peptide to coat tumor cells, resulting in tumor clearance by E7-specific CD8⁺ T cells. The presentation of the E7 peptide by cancer cells can then render tumor cells susceptible to the killing of preexisting E7-specific CD8⁺ T cells and contribute to tumor clearance. Our finding suggests a synergistic approach to not only enhance antigen-specific tumor clearance but also bypass immune tolerance.

Delivery of IL-2 to the T Cell Surface Through Phosphatidylserine Permits Robust Expansion of CD8 T Cells

The phospholipid phosphatidylserine (PS) is naturally maintained on the cytoplasmic side of the plasma membrane. Independent of apoptosis, PS is redistributed to the surface of CD8 T cells in response to TCR-mediated activation. Annexin V (AnnV) is a protein known to bind PS with high affinity and has been effectively utilized to anchor antigen to the surface of CD8 T cells. To expand these studies, we aimed to exploit TCR activation driven PS exposure as a target to deliver cytokine, namely interleukin-2 (IL-2), to the surface of CD8 T cells. This was accomplished using a novel chimeric fusion protein of annexin V and interleukin 2 (AnnV-IL2). In vitro analysis revealed that AnnV-IL2 is able to specifically bind PS on the T cell surface following TCR stimulation. Consequently, AnnV-IL2 proved to be significantly more effective at enhancing T cell activation compared to recombinant IL-2. In vivo, AnnV-IL2 promotes robust expansion of antigen-specific cells capable of interferon gamma (IFNγ) production when administered following peptide vaccination. Importantly, upon antigen rechallenge, AnnV-IL2 treatment mice demonstrated a stronger secondary expansion, indicating durability of AnnV-IL2 mediated responses. Our data supports the use of AnnV-IL2 to modulate antigen-specific T cell immunity and demonstrates that the PS-AnnV axis is a feasible mechanism to target diverse cargo to CD8 T cells.

A survival tree based on stabilized score tests for high-dimensional covariates

A survival tree can classify subjects into different survival prognostic groups. However, when data contains high-dimensional covariates, the two popular classification trees exhibit fatal drawbacks. The logrank tree is unstable and tends to have false nodes; the conditional inference tree is difficult to interpret the adjusted P-value for high-dimensional tests. Motivated by these problems, we propose a new survival tree based on the stabilized score tests. We propose a novel matrix-based algorithm in order to tests a number of nodes simultaneously via stabilized score tests. We propose a recursive partitioning algorithm to construct a survival tree and develop our original R package uni.survival.tree (https://cran.r-project.org/package=uni.survival.tree) for implementation. Simulations are performed to demonstrate the superiority of the proposed method over the existing methods. The lung cancer data analysis demonstrates the usefulness of the proposed method.

Novel phosphatidylserine-binding molecule enhances antitumor T-cell responses by targeting immunosuppressive exosomes in human tumor microenvironments

Background

The human tumor microenvironment (TME) is a complex and dynamic milieu of diverse acellular and cellular components, creating an immunosuppressive environment, which contributes to tumor progression. We have previously shown that phosphatidylserine (PS) expressed on the surface of exosomes isolated from human TMEs is causally linked to T-cell immunosuppression, representing a potential immunotherapeutic target. In this study, we investigated the effect of ExoBlock, a novel PS-binding molecule, on T-cell responses in the TME.

Methods

We designed and synthesized a new compound, (ZnDPA)₆-DP-15K, a multivalent PS binder named ExoBlock. The PS-binding avidity of ExoBlock was tested using an in vitro competition assay. The ability of this molecule to reverse exosome-mediated immunosuppression in vitro was tested using human T-cell activation assays. The in vivo therapeutic efficacy of ExoBlock was then tested in two different human tumor xenograft models, the melanoma-based xenomimetic (X-)mouse model, and the ovarian tumor-based omental tumor xenograft (OTX) model.

Results

ExoBlock was able to bind PS with high avidity and was found to consistently and significantly block the immunosuppressive activity of human ovarian tumor and melanoma-associated exosomes in vitro. ExoBlock was also able to significantly enhance T cell-mediated tumor suppression in vivo in both the X-mouse and the OTX model. In the X-mouse model, ExoBlock suppressed tumor recurrence in a T cell-dependent manner. In the OTX model, ExoBlock treatment resulted in an increase in the number as well as function of CD4 and CD8 T cells in the TME, which was associated with a reduction in tumor burden and metastasis, as well as in the number of circulating PS+ exosomes in tumor-bearing mice.

Conclusion

Our results establish that targeting exosomal PS in TMEs with ExoBlock represents a promising strategy to enhance antitumor T-cell responses.

Long-circulating XTEN864-annexin A5 fusion protein for phosphatidylserine-related therapeutic applications

Annexin A5 (anxA5) is a marker for apoptosis, but has also therapeutic potential in cardiovascular diseases, cancer, and, due to apoptotic mimicry, against dangerous viruses, which is limited by the short blood circulation. An 864-amino-acid XTEN polypeptide was fused to anxA5. XTEN864-anxA5 was expressed in Escherichia coli and purified using XTEN as tag. XTEN864-anxA5 was coupled with DTPA and indium-111. After intravenous or subcutaneous injection of ¹¹¹In-XTEN864-anxA5, mouse blood samples were collected for blood half-life determination and organ samples for biodistribution using a gamma counter. XTEN864-anxA5 was labeled with 6S-IDCC to confirm binding to apoptotic cells using flow cytometry. To demonstrate targeting of atherosclerotic plaques, XTEN864-anxA5 was labeled with MeCAT(Ho) and administered intravenously to atherosclerotic ApoE^−/− mice. MeCAT(Ho)-XTEN864-anxA5 was detected together with MeCAT(Tm)-MAC-2 macrophage antibodies by imaging mass cytometry (CyTOF) of aortic root sections. The ability of anxA5 to bind apoptotic cells was not affected by XTEN864. The blood half-life of XTEN864-anxA5 was 13 h in mice after IV injection, markedly longer than the 7-min half-life of anxA5. 96 h after injection, highest amounts of XTEN864-anxA5 were found in liver, spleen, and kidney. XTEN864-anxA5 was found to target the adventitia adjacent to atherosclerotic plaques. XTEN864-anxA5 is a long-circulating fusion protein that can be efficiently produced in E. coli and potentially circulates in humans for several days, making it a promising therapeutic drug.

Annexin Animal Models-From Fundamental Principles to Translational Research

Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca²⁺)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.

Secretion of Recombinant Human Annexin V in Fusion with the Super Folder GFP for Labelling Phosphatidylserine-Exposing Membranes

Annexin V (ANXV), mostly characterized by its ability to interact with biological membranes in a calcium-dependent manner. ANXV interacts mainly with phosphatidylserine (PS), for that fluorescent ANXV widely produced and used as a sensitive and specific probe to mark apoptotic cells or any PS-containing bilayers membranes. Many reports described the prokaryotic expression of recombinant human ANXV. To overcome some of E. coli expression limitations, we aimed in this work to investigate unconventional alternative expression system in mammalian cells for producing secreted human ANXV in fusion with the super folder green fluorescent protein (sfGFP). HEK239T cells were transfected using polyethylenimine (PEI) and pcDNA-sfGFP-ANXV plasmid. Forty-eight hours post transfection, direct fluorescence measurement, immunoblotting and ELISA confirmed the presence of secreted sfGFP-ANXV in cells supernatant. The yield of secreted 6 × His-tagged sfGFP-ANXV after affinity purification was estimated to be around 2 µg per 1 ml of cells supernatant. The secretion system was proper to produce a fully functional sfGFP-ANXV fusion protein in quantities enough to recognize and bind PS-containing surfaces or liposomes. Besides, biological assays such as flow cytometry and fluorescent microscopy confirmed the capacity of the secreted sfGFP-ANXV to detect PS exposure on apoptotic cells. Taken together, we present mammalian expression as a quick, affordable and endotoxin-free system to produce sfGFP-ANXV fusion protein. The secreted sfGFP-ANXV in eukaryotic system is a promising biotechnological tool, it opens up new horizons for additional applications in the detection of PS bearing surfaces and apoptosis in vitro and in vivo assays.

Age-Related Gene Alteration in Naïve and Memory T cells Using Precise Age-Tracking Model

In aged individuals, age-related changes in immune cells, especially T cell deficiency, are associated with an increased incidence of infection, tumor, and autoimmune disease, as well as an impaired response to vaccination. However, the features of gene expression levels in aged T cells are still unknown. Our previous study successfully tracked aged T cells generated from one wave of developing thymocytes of young age by a lineage-specific and inducible Cre-controlled reporter (TCRδ^CreERR26^ZsGreen mouse strain). In this study, we utilized this model and genome-wide transcriptomic analysis to examine changes in gene expression in aged naïve and memory T cell populations during the aging process. We identified profound gene alterations in aged CD4 and CD8 T cells. Both aged CD4⁺ and CD8⁺ naïve T cells showed significantly decreased organelle function. Importantly, genes associated with lymphocyte activation and function demonstrated a significant increase in aged memory T cells, accompanied by upregulation of immunosuppressive markers and immune checkpoints, revealing an abnormal T cell function in aged cells. Furthermore, aging significantly affects T cell survival and death signaling. While aged CD4 memory T cells exhibited pro-apoptotic gene signatures, aged CD8 memory T cells expressed anti-apoptotic genes. Thus, the transcriptional analysis of gene expression and signaling pathways in aged T cell subsets shed light on our understanding of altered immune function with aging, which will have great potential for clinical interventions for older adults.

Transforming Growth Factor-β: A Multifunctional Regulator of Cancer Immunity

Transforming growth factor-β (TGF-β) was originally identified as an anti-tumour cytokine. However, there is increasing evidence that it has important roles in the tumour microenvironment (TME) in facilitating cancer progression. TGF-β actively shapes the TME via modulating the host immunity. These actions are highly cell-type specific and complicated, involving both canonical and non-canonical pathways. In this review, we systemically update how TGF-β signalling acts as a checkpoint regulator for cancer immunomodulation. A better appreciation of the underlying pathogenic mechanisms at the molecular level can lead to the discovery of novel and more effective therapeutic strategies for cancer.

Transforming Growth Factor-β: A Multifunctional Regulator of Cancer Immunity

Simple Summary

Transforming growth factor beta (TGF-β) is a multifunctional cytokine that can restrict cancer onset but also promote cancer progression at late stages of cancer. The ability of TGF-β in producing diverse and sometimes opposing effects relies on its potential to control different cellular signalling and gene expression in distinct cell types, and environmental settings. The tumour promoting role of TGF-β is primarily mediated through its effects on the local tumour microenvironment (TME) of the cancer cells. In this review, we discuss the most recent research on the role and regulation of TGF-β, with a specific focus on its functions on promoting cancer progression through targeting different immune cells in the TME as well as its therapeutic perspectives.

Abstract

Transforming growth factor-β (TGF-β) was originally identified as an anti-tumour cytokine. However, there is increasing evidence that it has important roles in the tumour microenvironment (TME) in facilitating cancer progression. TGF-β actively shapes the TME via modulating the host immunity. These actions are highly cell-type specific and complicated, involving both canonical and non-canonical pathways. In this review, we systemically update how TGF-β signalling acts as a checkpoint regulator for cancer immunomodulation. A better appreciation of the underlying pathogenic mechanisms at the molecular level can lead to the discovery of novel and more effective therapeutic strategies for cancer.