Calreticulin-Multifunctional Chaperone in Immunogenic Cell Death: Potential Significance as a Prognostic Biomarker in Ovarian Cancer Patients

Pulsed electric field ablation as a candidate to enhance the anti-tumor immune response to immune checkpoint inhibitors

Cancer ablation with pulsed electric fields (PEFs) involves the delivery of high-voltage, short-duration electrical pulses that destabilize tumor cells, leading to cellular death. Unlike most conventional ablation technologies, PEF ablation is non-thermal, allowing for safe and targeted energy delivery to the tumor without damaging surrounding tissue and critical structures. PEFs allow for specific dosing, predictable treatment zones, and preservation of the extracellular matrix and adjacent vascular tissues. Preclinical and preliminary clinical data suggest that PEF ablation may induce inflammatory changes in the tumor microenvironment (TME) that engage host innate and adaptive immune cells, stimulating an anti-tumor response. Specifically, PEF promotes local and systemic anti-tumor immune activation through immunogenic cell death and the release of damage-associated molecular patterns (DAMPs) and tumor antigens. This tumor-specific immune activation could potentially enhance response to immune checkpoint inhibitor (ICI) therapies. Furthermore, PEF ablation induces the formation of tertiary lymphoid structures (TLSs) in the TME, which are predictive biomarkers for responsiveness to ICI across several solid tumors. This combination of effects activates antigen-presenting cells and stimulates the effector T cell response, which is often inhibited in ICI-resistant cancer patients. In this review, the onco-immunological characteristics of PEF ablation are discussed, with special emphasis placed on the clinical potential of PEF ablation to induce anti-cancer immune responses and enhance responsiveness to ICI therapy in ablated and non-ablated (abscopal) tumors.

O-GlcNAcylation in ovarian tumorigenesis and its therapeutic implications

Ovarian cancer is a prevalent malignancy among women, often associated with a poor prognosis. Post-translational modifications (PTMs), particularly O-GlcNAcylation, have been implicated in the progression of ovarian cancer. Emerging evidence indicates that dysregulation of O-GlcNAcylation contributes to the initiation and malignant progression of ovarian cancer. This review discusses the potential role of O-GlcNAcylation in ovarian tumorigenesis, with a focus on its regulation of various cellular signaling pathways, including p53, RhoA/ROCK/MLC, Ezrin/Radixin/Moesin (ERM), and β-catenin. This review also emphasizes the O-GlcNAcylation of critical proteins in ovarian cancer, such as SNAP-23, SNAP-29, E-cadherin, and calreticulin. Additionally, the potential of O-GlcNAcylation to enhance immunotherapy for ovarian cancer patients is explored. Several compounds targeting OGT and OGA in ovarian cancer are also highlighted. Targeting the dynamic and versatile nature of O-GlcNAcylation could undoubtedly contribute to more effective treatments and improved outcomes for ovarian cancer patients.

Proteomics for Biomarker Discovery in Gynecological Cancers: A Systematic Review

The present study aims to summarize the current biomarker landscape in gynecological cancers (GCs) and incorporate bioinformatics analysis to highlight specific biological processes. The literature was retrieved from PubMed, Web of Science, Embase, Scopus, Ovid Medline, and Cochrane Library. The final search was conducted on December 7, 2022. Prospective registration was completed with the PROSPERO with registration number CRD42023477145. This systematic review covered proteomic research on biomarkers for cervical, endometrial, and ovarian cancers. The PANTHER classification system was used to classify the shortlisted candidate biomarkers (CBs), and the STRING database was utilized to visualize protein-protein interaction networks. A total of 23 articles were included in this systematic review. Consistently regulated CBs in the GCs include collagen alpha-2(I) chain, collagen alpha-1(III) chain, collagen alpha-2(V) chain, calreticulin, protein disulfide-isomerase A3, heat shock protein family A (Hsp70) member 5, prolyl 4-hydroxylase, beta polypeptide, fibrinogen alpha chain, fibrinogen gamma chain, apolipoprotein B-100, apolipoprotein C-IV, and apolipoprotein M. In conclusion, collagens, fibrinogens, chaperones, and apolipoproteins were revealed to be replicated in GCs and to be regulated consistently. These CBs contribute to GC etiology and physiology by participating in collagen fibril organization, blood coagulation, protein folding in endoplasmic reticulum, and lipid transporter activity.

Unraveling the potential of Epicatechin gallate from crataegus oxyacantha in targeting aberrant cardiac Ca2+ signalling proteins: an in-depth in-silico investigation for heart failure therapy

The cardiovascular sarcoplasmic reticulum (SR) calcium (Ca2+) ATPase is an imperative determinant of cardiac functionality. In addition, anomalies in Ca2+ handling protein and atypical energy metabolism are inherent in heart failure (HF). Moreover, Ca2+ overload in SR leads to mitochondrial matrix Ca2+ overload, which can trigger the generation of Reactive Oxygen Species (ROS), culminating in the triggering of the Permeability Transition Pore (PTP) and Cytochrome C release, resulting in apoptosis that leads to arrhythmias and numerous disorders. Although proteins involved in the molecular mechanism of Ca2+ dysfunction regarding mitochondrial dysfunction remains elusive, this study aims to assess the major Ca2+ handling proteins which may be involved in the Ca2+ malfunction that causes mitochondrial dysfunction and predicting the most effective drug by targeting the analyzed Ca2+ handling proteins through various insilico analyses. Thirteen proteins absorbed from interaction analysis were docked with four optimal phytochemicals from Crataegus oxyacantha (COC). Furthermore, The ADME profile of tyramine, vitexin, Epicatechin, and Epicatechin gallate was acclimated to evaluate potential drugability utilizing QikProp. So, molecular docking evaluations were performed using Glide (Maestro), autodock, and vina. Based on the results of 156 dockings by Maestro, auto-dock, and auto-dock vina, PKAC-a with Epicatechin gallate exhibits good interaction. Therefore, a 2000 ns molecular dynamics (MD) simulation was utilized to assess the feasible phytochemical Epicatechin gallate - PKAC-a complex binding stability utilizing Desmond and this study confirmed that Epicatechin gallate from COC has high possibilities to inhibit the aberrant cardiac Ca2+ signaling proteins due to its conformational rigidity.

DAMPs in immunosenescence and cancer

Damage-associated molecular patterns (DAMPs) are endogenous molecules released by cells in response to injury or stress, recognized by host pattern recognition receptors that assess the immunological significance of cellular damage. The interaction between DAMPs and innate immune receptors triggers sterile inflammation, which serves a dual purpose: promoting tissue repair and contributing to pathological conditions, including age-related diseases. Chronic inflammation mediated by DAMPs accelerates immunosenescence and influences both tumor progression and anti-tumor immunity, underscoring the critical role of DAMPs in the nexus between aging and cancer. This review explores the characteristics of immunosenescence and its impact on age-related cancers, investigates the various types of DAMPs, their release mechanisms during cell death, and the immune activation pathways they initiate. Additionally, we examine the therapeutic potential of targeting DAMPs in age-related diseases. A detailed understanding of DAMP-induced signal transduction could provide critical insights into immune regulation and support the development of innovative therapeutic strategies.

Radiation drives tertiary lymphoid structures to reshape TME for synergized antitumour immunity

Radiotherapy (RT) plays a key role in the tumour microenvironment (TME), impacting the immune response via cellular and humoral immunity. RT can induce local immunity to modify the TME. It can stimulate dendritic cell maturation and T-cell infiltration. Moreover, B cells, macrophages and other immune cells may also be affected. Tertiary lymphoid structure (TLS) is a unique structure within the TME and a class of aggregates containing T cells, B cells and other immune cells. The maturation of TLS is determined by the presence of mature dendritic cells, the density of TLS is determined by the number of immune cells. TLS maturation and density both affect the antitumour immune response in the TME. This review summarized the recent research on the impact and the role of RT on TLS, including the changes of TLS components and formation conditions and the mechanism of how RT affects TLS and transforms the TME. RT may promote TLS maturation and density to modify the TME regarding enhanced antitumour immunity.

Immunogenic cell death-based oncolytic virus therapy: A sharp sword of tumor immunotherapy

Tumor immunotherapy, especially immune checkpoint inhibitors (ICIs), has been applied in clinical practice, but low response to immune therapies remains a thorny issue. Oncolytic viruses (OVs) are considered promising for cancer treatment because they can selectively target and destroy tumor cells followed by spreading to nearby tumor tissues for a new round of infection. Immunogenic cell death (ICD), which is the major mechanism of OVs' anticancer effects, is induced by endoplasmic reticulum stress and reactive oxygen species overload after virus infection. Subsequent release of specific damage-associated molecular patterns (DAMPs) from different types of tumor cells can transform the tumor microenvironment from "cold" to "hot". In this paper, we broadly define ICD as those types of cell death that is immunogenic, and describe their signaling pathways respectively. Focusing on ICD, we also elucidate the advantages and disadvantages of recent combination therapies and their future prospects.

Parasites revive hope for cancer therapy

Parasites have attained a life-long stigma of being detrimental organisms with deleterious outcomes. Yet, recently, a creditable twist was verified that can dramatically change our perception of those parasites from being a source of misery to millions of people to a useful anti-cancerous tool. Various parasites have shown promise to combat cancer in different experimental models, including colorectal, lung, and breast cancers, among others. Helminths and protozoan parasites, as well as their derivatives such as Echinococcus granulosus protein KI-1, Toxoplasma gondii GRA15II, and Trypanosoma cruzi calreticulin, have demonstrated the ability to inhibit tumor growth, angiogenesis, and metastasis. This article provides an overview of the literature on various cancer types that have shown promising responses to parasite therapy in both in vitro and in vivo animal studies. Parasites have shown anti-neoplastic activity through a variety of mechanisms that collectively contribute to their anti-cancer properties. These include immunomodulation, inhibition of angiogenesis, and molecular mimicry with cancer cells. This review article sheds light on this intriguing emerging field and emphasizes the value of collaborative multidisciplinary research projects with funding agencies and pharmaceutical companies. Thus, these strategies would secure continuous exploration of this new avenue and accelerate the advancement of cancer therapy research. Although experimental studies are heavily conducted by leaps and bounds, further steps are definitely lagging. Upgrading research from the experimental level to the clinical trial would be a wise progression toward efficient exploitation of the anti-neoplastic capabilities of parasites, ultimately saving countless lives.

Immunogenicity of radiotherapy on bone metastases from prostate adenocarcinoma: What is the future for the combination with radiotherapy/immunotherapy?

Bone metastatic prostate cancers (PCa) are resistant to usual immunotherapies such as checkpoint inhibitors. The main hypothesis related to this immunoresistance is the lack of antigens to stimulate anti-tumor immunity. External radiation is a potential inducer antigens presentation and thus to immunotherapy proprieties. The aim of this review is to describe the tumor microenvironment specificities, especially in bone metastasis and the immune modifications after radiation therapy on a metastatic castration-resistant PCa population. PCa microenvironment is immunosuppressive because of many tumor factors. The complex interplay between PCa cells and bone microenvironment leads to a 'vicious circle' promoting bone metastasis. Furthermore, the immune and bone systems, are connected through an osteoclastogenic cytokine: the Receptor Activator Nuclear Factor Kappa B ligand. Adapted doses of ionizing radiation play a dual role on the tumor. Indeed, radiotherapy leads to immunogenicity by inducing damage associated with molecular patterns. However, it also induces an immunosuppressive effect by increasing the number of immunosuppressive cells. Interestingly, the abscopal effect could be used to optimize immunotherapy potential, especially on bone metastasis. Radiotherapy and immunotherapy combination is a promising strategy, however further studies are necessary to determine the more efficient types of radiation and to control the abscopal effect.

Ultrasmall Metal TPZ Complexes with Deep Tumor Penetration for Enhancing Radiofrequency Ablation Therapy and Inducing Antitumor Immune Responses

Radiofrequency ablation (RFA) is one of the most common minimally invasive techniques for the treatment of solid tumors, but residual malignant tissues or small satellite lesions after insufficient RFA (iRFA) are difficult to remove, often leading to metastasis and recurrence. Here, Fe-TPZ nanoparticles are designed by metal ion and (TPZ) ligand complexation for synergistic enhancement of RFA residual tumor therapy. Fe-TPZ nanoparticles are cleaved in the acidic microenvironment of the tumor to generate Fe2+ and TPZ. TPZ, an anoxia-dependent drug, is activated in residual tumors and generates free radicals to cause tumor cell death. Elevated Fe2+ undergoes a redox reaction with glutathione (GSH), inducing a strong Fenton effect and promoting the production of the highly toxic hydroxyl radical (•OH). In addition, the ROS/GSH imbalance induced by this treatment promotes immunogenic cell death (ICD), which triggers the release of damage-associated molecular patterns, macrophage polarization, and lymphocyte infiltration, thus triggering a systemic antitumor immune response and noteworthy prevention of tumor metastasis. Overall, this integrated treatment program driven by multiple microenvironment-dependent pathways overcomes the limitations of the RFA monotherapy approach and thus improves tumor prognosis. Furthermore, these findings aim to provide new research ideas for regulating the tumor immune microenvironment.

Emerging role of immunogenic cell death in cancer immunotherapy: Advancing next-generation CAR-T cell immunotherapy by combination

Immunogenic cell death (ICD) is a stress-driven form of regulated cell death (RCD) in which dying tumor cells' specific signaling pathways are activated to release damage-associated molecular patterns (DAMPs), leading to the robust anti-tumor immune response as well as a reversal of the tumor immune microenvironment from "cold" to "hot". Chimeric antigen receptor (CAR)-T cell therapy, as a landmark in anti-tumor immunotherapy, plays a formidable role in hematologic malignancies but falls short in solid tumors. The Gordian knot of CAR-T cells for solid tumors includes but is not limited to, tumor antigen heterogeneity or absence, physical and immune barriers of tumors. The combination of ICD induction therapy and CAR-T cell immunotherapy is expected to promote the intensive use of CAR-T cell in solid tumors. In this review, we summarize the characteristics of ICD, stress-responsive mechanism, and the synergistic effect of various ICD-based therapies with CAR-T cells to effectively improve anti-tumor capacity.

S-Sulfenylation Driven Antigen Capture Boosted by Radiation for Enhanced Cancer Immunotherapy

Radiotherapy (RT)-induced in situ vaccination greatly promotes the development of personalized cancer vaccines owing to the massive release of antigens initiated by tumor-localized RT eliciting the tumor-specific immune response. However, its broad application in cancer treatment is seriously impeded by poor antigen cross-presentation, low response rate, and short duration of efficacy. Herein, the tumor-antigen-capturing nanosystem dAuNPs@CpG consisting of gold nanoparticles, 3,5-cyclohexanedione (CHD), and immunoadjuvant CpG were fabricated to enhance RT-induced vaccination. Taking advantage of the specific covalent binding between CHD and sulfenic acids of antigen proteins, we show that this nanoplatform has an unexpected potential to capture the sulfenylated tumor-derived protein antigens (TDPAs) induced by RT to in situ generate a vaccination effect, achieving significant growth suppression of both primary and distant tumors in combination with PD-1 blockade. We thus believe that our work presents a powerful and effective means to improve the synergistic tumor radioimmunotherapy.

"Find Me" and "Eat Me" signals: tools to drive phagocytic processes for modulating antitumor immunity

Phagocytosis, a vital defense mechanism, involves the recognition and elimination of foreign substances by cells. Phagocytes, such as neutrophils and macrophages, rapidly respond to invaders; macrophages are especially important in later stages of the immune response. They detect "find me" signals to locate apoptotic cells and migrate toward them. Apoptotic cells then send "eat me" signals that are recognized by phagocytes via specific receptors. "Find me" and "eat me" signals can be strategically harnessed to modulate antitumor immunity in support of cancer therapy. These signals, such as calreticulin and phosphatidylserine, mediate potent pro-phagocytic effects, thereby promoting the engulfment of dying cells or their remnants by macrophages, neutrophils, and dendritic cells and inducing tumor cell death. This review summarizes the phagocytic "find me" and "eat me" signals, including their concepts, signaling mechanisms, involved ligands, and functions. Furthermore, we delineate the relationships between "find me" and "eat me" signaling molecules and tumors, especially the roles of these molecules in tumor initiation, progression, diagnosis, and patient prognosis. The interplay of these signals with tumor biology is elucidated, and specific approaches to modulate "find me" and "eat me" signals and enhance antitumor immunity are explored. Additionally, novel therapeutic strategies that combine "find me" and "eat me" signals to better bridge innate and adaptive immunity in the treatment of cancer patients are discussed.

Cytokine release syndrome following durvalumab and tremelimumab in advanced hepatocellular carcinoma: A case report with cytokine and damage-associated molecular pattern analysis

Cytokine release syndrome (CRS) is a systemic inflammatory syndrome that causes fatal circulatory failure due to hypercytokinemia, and subsequent immune cell hyperactivation caused by therapeutic agents, pathogens, cancers, and autoimmune diseases. In recent years, CRS has emerged as a rare, but significant, immune-related adverse event linked to immune checkpoint inhibitor therapy. Furthermore, several previous studies suggested that damage-associated molecular patterns (DAMPs) could be involved in malignancy-related CRS. In this study, we present a case of severe CRS following combination therapy with durvalumab and tremelimumab for advanced hepatocellular carcinoma, which recurred during treatment, as well as an analysis of cytokine and DAMPs trends. A 35-year-old woman diagnosed with hepatocellular carcinoma underwent a partial hepatectomy. Due to cancer recurrence, she started a combination of durvalumab and tremelimumab. Then, 29 days post-administration, she developed fever and headache, initially suspected as sepsis. Despite antibiotics, her condition worsened, leading to disseminated intravascular coagulation and hemophagocytic syndrome. The clinical course and elevated serum interleukin-6 levels led to a CRS diagnosis. Steroid pulse therapy was administered, resulting in temporary improvement. However, she relapsed with increased interleukin-6, prompting tocilizumab treatment. Her condition improved, and she was discharged on day 22. Measurements of inflammatory cytokines interferon-γ, tumor necrosis factor-α, and DAMPs, along with interleukin-6, using preserved serum samples, confirmed marked elevation at CRS onset. CRS can occur after the administration of any immune checkpoint inhibitor, with the most likely trigger being the release of DAMPs associated with tumor collapse.

Challenges of Regulated Cell Death: Implications for Therapy Resistance in Cancer

Regulated cell death, a regulatory form of cell demise, has been extensively studied in multicellular organisms. It plays a pivotal role in maintaining organismal homeostasis under normal and pathological conditions. Although alterations in various regulated cell death modes are hallmark features of tumorigenesis, they can have divergent effects on cancer cells. Consequently, there is a growing interest in targeting these mechanisms using small-molecule compounds for therapeutic purposes, with substantial progress observed across various human cancers. This review focuses on summarizing key signaling pathways associated with apoptotic and autophagy-dependent cell death. Additionally, it explores crucial pathways related to other regulated cell death modes in the context of cancer. The discussion delves into the current understanding of these processes and their implications in cancer treatment, aiming to illuminate novel strategies to combat therapy resistance and enhance overall cancer therapy.

Nanoparticle-mediated immunogenic cell death for cancer immunotherapy

The field of cancer therapy is witnessing the emergence of immunotherapy, an innovative approach that activates the body own immune system to combat cancer. Immunogenic cell death (ICD) has emerged as a prominent research focus in the field of cancer immunotherapy, attracting significant attention in recent years. The activation of ICD can induce the release of damage-associated molecular patterns (DAMPs), such as calreticulin (CRT), adenosine triphosphate (ATP), high mobility group box protein 1 (HMGB1), and heat shock proteins (HSP). Subsequently, this process promotes the maturation of innate immune cells, including dendritic cells (DCs), thereby triggering a T cell-mediated anti-tumor immune response. The activation of the ICD ultimately leads to the development of long-lasting immune responses against tumors. Studies have demonstrated that partial therapeutic approaches, such as chemotherapy with doxorubicin, specific forms of radiotherapy, and phototherapy, can induce the generation of ICD. The main focus of this article is to discuss and review the therapeutic methods triggered by nanoparticles for ICD, while briefly outlining their anti-tumor mechanism. The objective is to provide a comprehensive reference for the widespread application of ICD.

DAMPs and DAMP-sensing receptors in inflammation and diseases

Damage-associated molecular patterns (DAMPs) are endogenous danger molecules produced in cellular damage or stress, and they can activate the innate immune system. DAMPs contain multiple types of molecules, including nucleic acids, proteins, ions, glycans, and metabolites. Although these endogenous molecules do not trigger immune response under steady-state condition, they may undergo changes in distribution, physical or chemical property, or concentration upon cellular damage or stress, and then they become DAMPs that can be sensed by innate immune receptors to induce inflammatory response. Thus, DAMPs play an important role in inflammation and inflammatory diseases. In this review, we summarize the conversion of homeostatic molecules into DAMPs; the diverse nature and classification, cellular origin, and sensing of DAMPs; and their role in inflammation and related diseases. Furthermore, we discuss the clinical strategies to treat DAMP-associated diseases via targeting DAMP-sensing receptors.

Advancements in Stimulus-Responsive Co-Delivery Nanocarriers for Enhanced Cancer Immunotherapy

Cancer immunotherapy has emerged as a novel therapeutic approach against tumors, with immune checkpoint inhibitors (ICIs) making significant clinical practice. The traditional ICIs, PD-1 and PD-L1, augment the cytotoxic function of T cells through the inhibition of tumor immune evasion pathways, ultimately leading to the initiation of an antitumor immune response. However, the clinical implementation of ICIs encounters obstacles stemming from the existence of an immunosuppressive tumor microenvironment and inadequate infiltration of CD8+T cells. Considerable attention has been directed towards advancing immunogenic cell death (ICD) as a potential solution to counteract tumor cell infiltration and the immunosuppressive tumor microenvironment. This approach holds promise in transforming "cold" tumors into "hot" tumors that exhibit responsiveness to antitumor. By combining ICD with ICIs, a synergistic immune response against tumors can be achieved. However, the combination of ICD inducers and PD-1/PD-L1 inhibitors is hindered by issues such as poor targeting and uncontrolled drug release. An advantageous solution presented by stimulus-responsive nanocarrier is integrating the physicochemical properties of ICD inducers and PD-1/PD-L1 inhibitors, facilitating precise delivery to specific tissues for optimal combination therapy. Moreover, these nanocarriers leverage the distinct features of the tumor microenvironment to accomplish controlled drug release and regulate the kinetics of drug delivery. This article aims to investigate the advancement of stimulus-responsive co-delivery nanocarriers utilizing ICD and PD-1/PD-L1 inhibitors. Special focus is dedicated to exploring the advantages and recent advancements of this system in enabling the combination of ICIs and ICD inducers. The molecular mechanisms of ICD and ICIs are concisely summarized. In conclusion, we examine the potential research prospects and challenges that could greatly enhance immunotherapeutic approaches for cancer treatment.

Immunostimulatory effects of thermal ablation: Challenges and future prospects

ABSTRACT

This literature explores the immunostimulatory effects of thermal ablation in the tumor microenvironment, elucidating the mechanisms such as immunogenic cell death, tumor-specific antigens, and damage-associated molecular patterns. Furthermore, it outlines critical issues associated with thermal ablation-induced immunostimulatory challenges and offers insights into future research avenues and potential therapeutic strategies.

Calreticulin: Endoplasmic reticulum Ca2+ gatekeeper

Endoplasmic reticulum (ER) luminal Ca2+ is vital for the function of the ER and regulates many cellular processes. Calreticulin is a highly conserved, ER-resident Ca2+ binding protein and lectin-like chaperone. Over four decades of studying calreticulin demonstrate that this protein plays a crucial role in maintaining Ca2+ supply under different physiological conditions, in managing access to Ca2+ and how Ca2+ is used depending on the environmental events and in making sure that Ca2+ is not misused. Calreticulin plays a role of ER luminal Ca2+ sensor to manage Ca2+-dependent ER luminal events including maintaining interaction with its partners, Ca2+ handling molecules, substrates and stress sensors. The protein is strategically positioned in the lumen of the ER from where the protein manages access to and distribution of Ca2+ for many cellular Ca2+-signalling events. The importance of calreticulin Ca2+ pool extends beyond the ER and includes influence of cellular processes involved in many aspects of cellular pathophysiology. Abnormal handling of the ER Ca2+ contributes to many pathologies from heart failure to neurodegeneration and metabolic diseases.

Evaluation of the cytotoxic and immunomodulatory effects of sonodynamic therapy in human pancreatic cancer spheroids

Sonodynamic therapy (SDT) exploits the energy generated by ultrasound (US) to activate sound-sensitive drugs (sonosensitizers), leading to the generation of reactive oxygen species (ROS) and cancer cell death. Two-dimensional (2D) and three-dimensional (3D) cultures of human pancreatic cancer BxPC-3 cells were chosen as the models with which to investigate the therapeutic effects of the US-activated sonosensitizer IR-780 as pancreatic cancer is still one of the most lethal types of cancer. The effects of SDT, including ROS production, cancer cell death and immunogenic cell death (ICD), were extensively investigated. When subjected to US, IR-780 triggered significant ROS production and caused cancer cell death after 24 h (p ≤ 0.01). Additionally, the activation of dendritic cells (DCs) led to an effective immune response against the cancer cells undergoing SDT-induced death. BxPC-3 spheroids were developed and studied extensively to validate the findings observed in 2D BxPC-3 cell cultures. An analysis of the pancreatic cancer spheroid section revealed significant SDT-induced cancer cell death after 48 h after the treatment (p ≤ 0.01), with this being accompanied by the presence of SDT-induced damage-associated molecular patterns (DAMPs), such as calreticulin (CRT) and high mobility group box 1 (HMGB1). In conclusion, the data obtained demonstrates the anticancer efficacy of SDT and its immunomodulatory potential via action as an ICD-inducer.

Effects of radiation therapy on tumor microenvironment: an updated review

ABSTRACT

Cancer is a major threat to human health and causes death worldwide. Research on the role of radiotherapy (RT) in the treatment of cancer is progressing; however, RT not only causes fatal DNA damage to tumor cells, but also affects the interactions between tumor cells and different components of the tumor microenvironment (TME), including immune cells, fibroblasts, macrophages, extracellular matrix, and some soluble products. Some cancer cells can survive radiation and have shown strong resistance to radiation through interaction with the TME. Currently, the complex relationships between the tumor cells and cellular components that play major roles in various TMEs are poorly understood. This review explores the relationship between RT and cell-cell communication in the TME from the perspective of immunity and hypoxia and aims to identify new RT biomarkers and treatment methods in lung cancer to improve the current status of unstable RT effect and provide a theoretical basis for further lung cancer RT sensitization research in the future.

Establishing protein expression profiles involved in tooth development using a proteomic approach

Various growth and transcription factors are involved in tooth development and developmental abnormalities; however, the protein dynamics do not always match the mRNA expression level. Using a proteomic approach, this study comprehensively analyzed protein expression in epithelial and mesenchymal tissues of the tooth germ during development. First molar tooth germs from embryonic day 14 and 16 Crlj:CD1 (ICR) mouse embryos were collected and separated into epithelial and mesenchymal tissues by laser microdissection. Mass spectrometry of the resulting proteins was carried out, and three types of highly expressed proteins [ATP synthase subunit beta (ATP5B), receptor of activated protein C kinase 1 (RACK1), and calreticulin (CALR)] were selected for immunohistochemical analysis. The expression profiles of these proteins were subsequently evaluated during all stages of amelogenesis using the continuously growing incisors of 3-week-old male ICR mice. Interestingly, these three proteins were specifically expressed depending on the stage of amelogenesis. RACK1 was highly expressed in dental epithelial and mesenchymal tissues during the proliferation and differentiation stages of odontogenesis, except for the pigmentation stage, whereas ATP5B and CALR immunoreactivity was weak in the enamel organ during the early stages, but became intense during the maturation and pigmentation stages, although the timing of the increased protein expression was different between the two. Overall, RACK1 plays an important role in maintaining the cell proliferation and differentiation in the apical end of incisors. In contrast, ATP5B and CALR are involved in the transport of minerals and the removal of organic materials as well as matrix deposition for CALR.

Stimulators of immunogenic cell death for cancer therapy: focusing on natural compounds

A growing body of evidence indicates that the anticancer effect of the immune system can be activated by the immunogenic modulation of dying cancer cells. Cancer cell death, as a result of the activation of an immunomodulatory response, is called immunogenic cell death (ICD). This regulated cell death occurs because of increased immunogenicity of cancer cells undergoing ICD. ICD plays a crucial role in stimulating immune system activity in cancer therapy. ICD can therefore be an innovative route to improve anticancer immune responses associated with releasing damage-associated molecular patterns (DAMPs). Several conventional and chemotherapeutics, as well as preclinically investigated compounds from natural sources, possess immunostimulatory properties by ICD induction. Natural compounds have gained much interest in cancer therapy owing to their low toxicity, low cost, and inhibiting cancer cells by interfering with different mechanisms, which are critical in cancer progression. Therefore, identifying natural compounds with ICD-inducing potency presents agents with promising potential in cancer immunotherapy. Naturally derived compounds are believed to act as immunoadjuvants because they elicit cancer stress responses and DAMPs. Acute exposure to DAMP molecules can activate antigen-presenting cells (APCs), such as dendritic cells (DCs), which leads to downstream events by cytotoxic T lymphocytes (CTLs) and natural killer cells (NKs). Natural compounds as inducers of ICD may be an interesting approach to ICD induction; however, parameters that determine whether a compound can be used as an ICD inducer should be elucidated. Here, we aimed to discuss the impact of multiple ICD inducers, mainly focusing on natural agents, including plant-derived, marine molecules, and bacterial-based compounds, on the release of DAMP molecules and the activation of the corresponding signaling cascades triggering immune responses. In addition, the potential of synthetic agents for triggering ICD is also discussed.

Harnessing Oncolytic Extracellular Vesicles for Tumor Cell-Preferential Cytoplasmic Delivery of Misfolded Proteins for Cancer Immunotherapy

In this study, extracellular vesicles (EVs) are reimagined as more than just a cellular waste disposal system and are repurposed for cancer immunotherapy. Potent oncolytic EVs (bRSVF-EVs) loaded with misfolded proteins (MPs) are engineered, which are typically considered cellular debris. By impairing lysosomal function using bafilomycin A1 and expressing the respiratory syncytial virus F protein, a viral fusogen, MPs are successfully loaded into the EVs expressing RSVF. bRSVF-EVs preferentially transplant a xenogeneic antigen onto cancer cell membranes in a nucleolin-dependent manner, triggering an innate immune response. Furthermore, bRSVF-EV-mediated direct delivery of MPs into the cancer cell cytoplasm initiates endoplasmic reticulum stress and immunogenic cell death (ICD). This mechanism of action leads to substantial antitumor immune responses in murine tumor models. Importantly, when combined with PD-1 blockade, bRSVF-EV treatment elicits robust antitumor immunity, resulting in prolonged survival and complete remission in some cases. Overall, the findings demonstrate that utilizing tumor-targeting oncolytic EVs for direct cytoplasmic delivery of MPs to induce ICD in cancer cells represents a promising approach for enhancing durable antitumor immunity.

Immunotherapeutic effect of photothermal-mediated exosomes secreted from breast cancer cells

Aim: Exosomal damage-associated molecular patterns can play a key role in immunostimulation and changing the cold tumor microenvironment to hot. Materials & methods: This study examined the immunostimulation effect of photothermal and hyperthermia-treated 4T1 cell-derived exosomes on 4T1 cell-induced breast tumors in BALB/c animal models. Exosomes were characterized for HSP70, HSP90 and HMGB-1 before injection into mice and tumor tissues were analyzed for IL-6, IL-12 and IL-1β, CD4 and CD8 T-cell permeability, and PD-L1 expression. Results: Thermal treatments increased high damage-associated molecular patterns containing exosome secretion and the permeability of T cells to tumors, leading to tumor growth inhibition. Conclusion: Photothermal-derived exosomes showed higher damage-associated molecular patterns than hyperthermia with a higher immunostimulation and inhibiting tumor growth effect.

Calreticulin: a multifunctional protein with potential therapeutic applications for chronic wounds

Calreticulin is recognized as a multifunctional protein that serves an essential role in diverse biological processes that include wound healing, modification and folding of proteins, regulation of the secretory pathway, cell motility, cellular metabolism, protein synthesis, regulation of gene expression, cell cycle regulation and apoptosis. Although the role of calreticulin as an endoplasmic reticulum-chaperone protein has been well described, several studies have demonstrated calreticulin to be a highly versatile protein with an essential role during wound healing. These features make it an ideal molecule for treating a complex, multifactorial diseases that require fine tuning, such as chronic wounds. Indeed, topical application of recombinant calreticulin to wounds in multiple models of wound healing has demonstrated remarkable pro-healing effects. Among them include enhanced keratinocyte and fibroblast migration and proliferation, induction of extracellular matrix proteins, recruitment of macrophages along with increased granulation tissue formation, all of which are important functions in promoting wound healing that are deregulated in chronic wounds. Given the high degree of diverse functions and pro-healing effects, application of exogenous calreticulin warrants further investigation as a potential novel therapeutic option for chronic wound patients. Here, we review and highlight the significant effects of topical application of calreticulin on enhancing wound healing and its potential as a novel therapeutic option to shift chronic wounds into healing, acute-like wounds.

Current perspectives on Vaxinia virus: an immuno-oncolytic vector in cancer therapy

Viruses are being researched as cutting-edge therapeutic agents in cancer due to their selective oncolytic action against malignancies. Immuno-oncolytic viruses are a potential category of anticancer treatments because they have natural features that allow viruses to efficiently infect, replicate, and destroy cancer cells. Oncolytic viruses may be genetically modified; engineers can use them as a platform to develop additional therapy modalities that overcome the limitations of current treatment approaches. In recent years, researchers have made great strides in the understanding relationship between cancer and the immune system. An increasing corpus of research is functioning on the immunomodulatory functions of oncolytic virus (OVs). Several clinical studies are currently underway to determine the efficacy of these immuno-oncolytic viruses. These studies are exploring the design of these platforms to elicit the desired immune response and to supplement the available immunotherapeutic modalities to render immune-resistant malignancies amenable to treatment. This review will discuss current research and clinical developments on Vaxinia immuno-oncolytic virus.

Effects of Electrochemotherapy on Immunologically Important Modifications in Tumor Cells

Electrochemotherapy (ECT) is a clinically acknowledged method that combines the use of anticancer drugs and electrical pulses. Electrochemotherapy with bleomycin (BLM) can induce immunogenic cell death (ICD) in certain settings. However, whether this is ubiquitous over different cancer types and for other clinically relevant chemotherapeutics used with electrochemotherapy is unknown. Here, we evaluated in vitro in the B16-F10, 4T1 and CT26 murine tumor cell lines, the electrochemotherapy triggered changes in the ICD-associated damage-associated molecular patterns (DAMPs): Calreticulin (CRT), ATP, High Mobility Group Box 1 (HMGB1), and four immunologically important cellular markers: MHCI, MHC II, PD-L1 and CD40. The changes in these markers were investigated in time up to 48 h after ECT. We showed that electrochemotherapy with all three tested chemotherapeutics induced ICD-associated DAMPs, but the induced DAMP signature was cell line and chemotherapeutic concentration specific. Similarly, electrochemotherapy with CDDP, OXA or BLM modified the expression of MHC I, MHC II, PD-L1 and CD40. The potential of electrochemotherapy to change their expression was also cell line and chemotherapeutic concentration specific. Our results thus put the electrochemotherapy with clinically relevant chemotherapeutics CDDP, OXA and BLM on the map of ICD inducing therapies.

The anticancer effect of PASylated calreticulin-targeting L-ASNase in solid tumor bearing mice with immunogenic cell death-inducing chemotherapy

L-Asparaginase (L-ASNase), a bacterial enzyme that degrades asparagine, has been commonly used in combination with several chemical drugs to treat malignant hematopoietic cancers such as acute lymphoblastic leukemia (ALL). In contrast, the enzyme was known to inhibit the growth of solid tumor cells in vitro, but not to be effective in vivo. We previously reported that two novel monobodies (CRT3 and CRT4) bound specifically with calreticulin (CRT) exposed on tumor cells and tissues during immunogenic cell death (ICD). Here, we engineered L-ASNases conjugated with monobodies at the N-termini and PAS200 tags at the C-termini (CRT3LP and CRT4LP). These proteins were expected to possess four monobody and PAS200 tag moieties, which did not disrupt the L-ASNase conformation. These proteins were expressed 3.8-fold more highly in E. coli than those without PASylation. The purified proteins were highly soluble, with much greater apparent molecular weights than expected ones. Their affinity (Kd) against CRT was about 2 nM, 4-fold higher than that of monobodies. Their enzyme activity (∼6.5 IU/nmol) was similar to that of L-ASNase (∼7.2 IU/nmol), and their thermal stability was significantly increased at 55 °C. Their half-life times were > 9 h in mouse sera, about 5-fold longer than that of L-ASNase (∼1.8 h). Moreover, CRT3LP and CRT4LP bound specifically with CRT exposed on tumor cells in vitro, and additively suppressed the tumor growth in CT-26 and MC-38 tumor-bearing mice treated with ICD-inducing drugs (doxorubicin and mitoxantrone) but not with a non-ICD-inducing drug (gemcitabine). All data indicated that PASylated CRT-targeted L-ASNases enhanced the anticancer efficacy of ICD-inducing chemotherapy. Taken together, L-ASNase would be a potential anticancer drug for treating solid tumors.

Heparin and calreticulin interact on the surface of early G0/G1 dividing rat mesangial cells to regulate hyperglycemic glucose-induced responses

Heparin can block pathological responses associated with diabetic nephropathy in animal models and human patients. Our previous studies showed that the interaction of heparin on the surface of rat mesangial cells (RMCs) entering G1 of cell division in hyperglycemic glucose: 1) blocked glucose uptake by glucose transporter 4; 2) inhibited cytosolic uridine diphosphate-glucose elevation that would occur within 6 h from G0/G1; and 3) prevented subsequent activation of hyaluronan synthesis in intracellular compartments and subsequent inflammatory responses. However, specific proteins that interact with heparin are unresolved. Here, we showed by live cell imaging that fluorescent heparin was rapidly internalized into the cytoplasm and then into the endoplasmic reticulum, Golgi, and nuclei compartments. Biotinylated-heparin was applied onto the surface of growth arrested G0/G1 RMCs in order to extract heparin-binding protein(s). SDS-PAGE gels showed two bands at ∼70 kDa in the extract that were absent when unlabeled heparin was used to compete. Trypsin digests of the bands were analyzed by MS and identified as calreticulin and prelamin A/C. Immunostaining with their antibodies identified the presence of calreticulin on the G0/G1 RMC cell surface. Previous studies have shown that calreticulin can be on the cell surface and can interact with the LDL receptor-related protein, which has been implicated in glucose transport by interaction with glucose transporter 4. Thus, cell surface calreticulin can act as a heparin receptor through a mechanism involving LRP1, which prevents the intracellular responses in high glucose and reprograms the cells to synthesize an extracellular hyaluronan matrix after division.

Nanotechnology-enabled immunogenic cell death for improved cancer immunotherapy

Tumor immunotherapy has revolutionized the field of oncology treatments in recent years. As one of the promising strategies of cancer immunotherapy, tumor immunogenic cell death (ICD) has shown significant potential for tumor therapy. Nanoparticles are widely used for drug delivery due to their versatile characteristics, such as stability, slow blood elimination, and tumor-targeting ability. To increase the specificity of ICD inducers and improve the efficiency of ICD induction, functionally specific nanoparticles, such as liposomes, nanostructured lipid carriers, micelles, nanodiscs, biomembrane-coated nanoparticles and inorganic nanoparticles have been widely reported as the vehicles to deliver ICD inducers in vivo. In this review, we summarized the strategies of different nanoparticles for ICD-induced cancer immunotherapy, and systematically discussed their advantages and disadvantages as well as provided feasible strategies for solving these problems. We believe that this review will offer some insights into the design of effective nanoparticulate systems for the therapeutic delivery of ICD inducers, thus, promoting the development of ICD-mediated cancer immunotherapy.

Elimination of Cancer Cells in Co-Culture: Role of Different Nanocarriers in Regulation of CD47 and Calreticulin-Induced Phagocytosis

Under healthy conditions, pro- and anti-phagocytic signals are balanced. Cluster of Differentiation 47 (CD47) is believed to act as an anti-phagocytic marker that is highly expressed on multiple types of human cancer cells including acute myeloid leukemia (AML) and lung and liver carcinomas, allowing them to escape phagocytosis by macrophages. Downregulating CD47 on cancer cells discloses calreticulin (CRT) to macrophages and recovers their phagocytic activity. Herein, we postulate that using a modified graphene oxide (GO) carrier to deliver small interfering RNA (siRNA) CD47 (CD47_siRNA) in AML, A549 lung, and HepG2 liver cancer cells in co-culture in vitro will silence CD47 and flag cancer cells for CRT-mediated phagocytosis. Results showed a high knockdown efficiency of CD47 and a significant increase in CRT levels simultaneously by using GO formulation as carriers in all used cancer cell lines. The presence of CRT on cancer cells was significantly higher than levels before knockdown of CD47 and was required to achieve phagocytosis in co-culture with human macrophages. Lipid nanoparticles (LNPs) and modified boron nitride nanotubes (BNPs) were used to carry CD47_siRNA, and the knockdown efficiency values of CD47 were compared in three cancer cells in co-culture, with an achieved knockdown efficiency of >95% using LNPs as carriers. Interestingly, the high efficiency of CD47 knockdown was obtained by using the LNPs and BNP carriers; however, an increase in CRT levels on cancer cells was not required for phagocytosis to happen in co-culture with human macrophages, indicating other pathways' involvement in the phagocytosis process. These findings highlight the roles of 2D (graphene oxide), 1D (boron nitride nanotube), and "0D" (lipid nanoparticle) carriers for the delivery of siRNA to eliminate cancer cells in co-culture, likely through different phagocytosis pathways in multiple types of human cancer cells. Moreover, these results provide an explanation of immune therapies that target CD47 and the potential use of these carriers in screening drugs for such therapies in vitro.

The therapeutic mavericks: Potent immunomodulating chaperones capable of treating human diseases

Two major chaperones, calreticulin (CRT) and binding immunoglobulin protein (GRP78/BiP) dependent on their location, have immunoregulatory or anti-inflammatory functions respectively. CRT induces pro-inflammatory cytokines, dendritic cell (DC) maturation and activates cytotoxic T cells against tumours. By contrast, GRP78/BiP induces anti-inflammatory cytokines, inhibits DC maturation and heightens T-regulatory cell responses. These latter functions rebalance immune homeostasis in inflammatory diseases, such as rheumatoid arthritis. Both chaperones are therapeutically relevant agents acting primarily on monocytes/DCs. Endogenous exposure of CRT on cancer cell surfaces acts as an 'eat-me' signal and facilitates improved elimination of stressed and dying tumour cells by DCs. Therefore, therapeutics that promote endogenous CRT translocation to the cell surface can improve the removal of cancer cells. However, infused recombinant CRT dampens this cancer cell eradication by binding directly to the DCs. Low levels of endogenous BiP appear as a surface biomarker of endoplasmic reticulum (ER) stress in some types of tumour cells, a reflection of cells undergoing proliferation, in which resulting hypoxia and nutrient deprivation perturb ER homeostasis triggering the unfolded protein response, leading to increased expression of GRP78/BiP and altered cellular location. Conversely, infusion of an analogue of GRP78/BiP (IRL201805) can lead to long-term immune resetting and restoration of immune homeostasis. The therapeutic potential of both chaperones relies on them being relocated from their intracellular ER environment. Ongoing clinical trials are employing therapeutic interventions to either enhance endogenous cell surface CRT or infuse IRL201805, thereby triggering several disease-relevant immune responses leading to a beneficial clinical outcome.

Modulating Chaperone-Mediated Autophagy and Its Clinical Applications in Cancer

Autophagy is a central mechanism for maintaining cellular homeostasis in health and disease as it provides the critical energy through the breakdown and recycling of cellular components and molecules within lysosomes. One of the three types of autophagy is chaperone-mediated autophagy (CMA), a degradation pathway selective for soluble cytosolic proteins that contain a targeting motif related to KFERQ in their amino acid sequence. This motif marks them as CMA substrate and is, in the initial step of CMA, recognised by the heat shock protein 70 (Hsc70). The protein complex is then targeted to the lysosomal membrane where the interaction with the splice variant A of the lysosomal-associated membrane protein-2 (LAMP-2A) results in its unfolding and translocation into the lysosome for degradation. Altered levels of CMA have been reported in a wide range of pathologies including many cancer types that upregulate CMA as part of the pro-tumorigenic phenotype, while in aging a decline is observed and associated with a decrease of LAMP-2 expression. The potential of altering CMA to modify a physiological or pathological process has been firmly established through genetic manipulation in animals and chemical interference with this pathway. However, its use for therapeutic purposes has remained limited. Compounds used to target and modify CMA have been applied successfully to gain a better understanding of its cellular mechanisms, but they are mostly not specific, also influence other autophagic pathways and are associated with high levels of toxicity. Here, we will focus on the molecular mechanisms involved in CMA regulation as well as on potential ways to intersect them, describe modulators successfully used, their mechanism of action and therapeutic potential. Furthermore, we will discuss the potential benefits and drawbacks of CMA modulation in diseases such as cancer.

Calreticulin as an Adjuvant In Vivo to Promote Dendritic Cell Maturation and Enhance Antigen-Specific T Lymphocyte Responses against Melanoma

An endoplasmic reticulum resident protein, calreticulin (CRT), participates in many cellular processes. CRT is a tumor-associated antigen with an important role in antitumor immunity. Previously, we reported that the recombinant CRT fragment 39-272 (CRT/39-272) exhibited superior immunobiological activity, activating macrophages to release cytokines and promoting dendritic cell (DC) maturation. However, the effect of CRT/39-272 in vivo, especially its adjuvant effect on in vivo antitumor immune responses, was not fully investigated. In this study, we constructed a fusion protein linking CRT/39-272 to an ovalbumin (OVA) peptide (residues 182–297, OVAp) and used the fusion protein (OVAp-CRT) to examine the adjuvant effect of CRT. We investigated whether CRT/39-272 could induce bone marrow-derived DC maturation and strongly promote the proliferation of OVA-specific T cells in vitro. Compared with OVAp, OVAp-CRT induced stronger antigen-specific T lymphocyte responses, including antigen-specific T cell proliferation, interferon-γ secretion, and cytotoxic T lymphocyte responses. OVAp-CRT-immunized mice generated significantly increased OVAp-specific antibody and CD4+/CD8+ memory T cells, which mediated long-term protective effects. OVAp-CRT upregulated CD40, CD80, and CD86 expressions in splenic conventional DCs. Furthermore, OVAp-CRT protected immunized mice against OVA-expressing B16 melanoma cells in vivo. Moreover, mice that were adoptively transferred with OVAp-CRT-pulsed DCs showed inhibited tumor growth and prolonged mouse survival. Our results demonstrate that CRT/39-272 can be used as a potential new adjuvant for tumor vaccines, and this finding may be useful in tumor vaccine development.

Trident Molecule with Nanobrush-Nanoparticle-Nanofiber Transition Property Spatially Suppresses Tumor Metastasis

Metastasis-induced high mortality of cancers urgently demands new approaches to simultaneously inhibit primary tumor metastasis and distant tumor growth. Herein, by rational design of a trident molecule Nap-Phe-Phe-Lys(SA-CPT)-Lys(SA-HCQ)-Tyr(H₂PO₃)-OH (Nap-CPT-HCQ-Yp) with three functional "spears" (i.e., a phosphotyrosine motif for enzymatic self-assembly, camptothecin (CPT) motif for chemotherapy, and hydroxychloroquine (HCQ) motif for autophagy inhibition) and nanobrush-nanoparticle-nanofiber transition property, we propose a novel strategy of intracellular enzymatic nanofiber formation and synergistic autophagy inhibition-enhanced chemotherapy and immunotherapy for spatial suppression of tumor metastasis. Under sequential alkaline phosphatase catalysis and carboxylesterase hydrolysis, Nap-CPT-HCQ-Yp undergoes nanobrush-nanoparticle-nanofiber transition, accompanied by the releases of CPT and HCQ. The formed intracellular nanofibers effectively inhibit the metastasis and invasion behaviors of cancer cells. Meanwhile, the released CPT and HCQ synergistically induce a prominent therapeutic effect through autophagy inhibition-enhanced chemotherapy. Furthermore, chemotherapy of Nap-CPT-HCQ-Yp enhances immunogenic cell death, resulting in the activation of toxic T-cells. Finally, a combination of checkpoint blockade therapy and Nap-CPT-HCQ-Yp-mediated chemotherapy elicits systemic antitumor immunity, thereby achieving efficient inhibitions of primary tumors as well as distant tumors in a breast tumor model. Our work offers a simple and feasible strategy for the design of "smart" multifunctional prodrugs to spatially suppress tumor metastasis.

Calreticulin Identified as One of the Androgen Response Genes That Trigger Full Regeneration of the Only Capable Mammalian Organ, the Deer Antler

Deer antlers are male secondary sexual characters that develop to become bone; they are unique appendages that, once lost, can fully regenerate from the permanent bony protuberances or pedicles. Pedicle periosteum (PP) is the tissue that gives rise to the regenerating antlers with three differentiation stages, namely, dormant (DoPP), potentiated (PoPP), and activated (AcPP). Thus far, the transition from the PoPP to the AcPP has not been studied. Our results showed that the AcPP cells maintained their original stem cell features by expressing mesenchymal stem cell (MSC) markers CD73, CD90, and CD105, although they had entered the proliferation mode. The differentially expressed genes (DEGs) in the AcPP compared with those of the PoPP were mainly involved in protein processing, cell cycle, and calcium signaling pathways. Calreticulin (CALR), an androgen response gene, was significantly differentially upregulated in the AcPP cells, and its expression level was negatively regulated by androgens, in contrast to the currently known model systems where all regulation is positive. The downregulation of CALR expression in the AcPP cells in vitro inhibited cell proliferation, induced apoptosis, and inhibited cell cycle progression at G1-S transition. Therefore, CALR is likely a downstream mediator of androgen hormones for triggering initiation of antler regeneration. We believe that the identification of CALR has not only discovered “one critical piece” of the “jigsaw puzzle” in the initiation of antler regeneration but also helps in revealing the mechanism underlying this unique mammalian epimorphic regeneration and has also opened a new avenue for the study of the nature of CALR regulation by androgen (putative binding partners), thus facilitating the identification of potential molecule(s) for investigation as targets for clinical evaluation.

In vivo hitchhiking of immune cells by intracellular self-assembly of bacteria-mimetic nanomedicine for targeted therapy of melanoma

Cell-based drug carriers are mostly prepared in vitro, which may negatively affect the physiological functions of cells, and induce possible immune rejections when applied to different individuals. In addition, the immunosuppressive tumor microenvironment limits immune cell-mediated delivery. Here, we report an in vivo strategy to construct cell-based nanomedicine carriers, where bacteria-mimetic gold nanoparticles (GNPs) are intravenously injected, selectively phagocytosed by phagocytic immune cells, and subsequently self-assemble into sizable intracellular aggregates via host-guest interactions. The intracellular aggregates minimize exocytosis of GNPs from immune cells and activate the photothermal property via plasmonic coupling effects. Phagocytic immune cells carry the intracellular GNP aggregates to melanoma tissue via inflammatory tropism. Moreover, an initial photothermal treatment (PTT) of the tumor induces tumor damage that subsequently provides positive feedback to recruit more immune cell-based carriers for enhanced targeting efficiency. The optimized secondary PTT notably improves antitumor immunotherapy, further strengthened by immune checkpoint blockade.

Yeast Secretes High Amounts of Human Calreticulin without Cellular Stress

The ER chaperone calreticulin (CALR) also has extracellular functions and can exit the mammalian cell in response to various factors, although the mechanism by which this takes place is unknown. The yeast Saccharomyces cerevisiae efficiently secretes human CALR, and the analysis of this process in yeast could help to clarify how it gets out of eukaryotic cells. We have achieved a secretion titer of about 140 mg/L CALR in our S. cerevisiae system. Here, we present a comparative quantitative whole proteome study in CALR-secreting yeast using non-equilibrium pH gradient electrophoresis (NEPHGE)-based two-dimensional gel electrophoresis (2DE) as well as liquid chromatography mass spectrometry in data-independent analysis mode (LC-MSE). A reconstructed carrier ampholyte (CA) composition of NEPHGE-based first-dimension separation for 2DE could be used instead of formerly commercially available gels. Using LC-MSE, we identified 1574 proteins, 20 of which exhibited differential expression. The largest group of differentially expressed proteins were structural ribosomal proteins involved in translation. Interestingly, we did not find any signs of cellular stress which is usually observed in recombinant protein-producing yeast, and we did not identify any secretory pathway proteins that exhibited changes in expression. Taken together, high-level secretion of human recombinant CALR protein in S. cerevisiae does not induce cellular stress and does not burden the cellular secretory machinery. There are only small changes in the cellular proteome of yeast secreting CALR at a high level.

The role of the inflammasome and its related pathways in ovarian cancer

Ovarian cancer (OC) is the most lethal tumor of the female reproductive tract and one of the most prevalent causes of death among female cancer patients. The absence of suitable procedures for early diagnosis, chemoresistance, and limited surgical debulking are all contributing to poor survival in patients. Despite aggressive treatments, the majority of patients have a recurrence within 16-22 months. Inflammasomes are multimeric protein complexes that play a major role in the innate immune system and inflammation. The overexpression of inflammasome-related pathways, including NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), Absent in melanoma 2 (AIM2), caspase-1, and Interleukin (IL)-1 have been reported in OC patients and in vitro cell lines. Therefore, inflammasome-related genes and protein might have a role in OC pathogenesis. Considering the potential relationship between inflammasome and OC, this study aimed to provide a literature-based review to explain the role of inflammasome and inflammation in cancer progression in OC.

Distinct roles in phagocytosis of the early and late increases of cell surface calreticulin induced by oxaliplatin

Calreticulin (CRT), a chaperone typically located in the endoplasmic reticulum (ER), is known to translocate to the cell surface in response to anticancer drugs. Cell surface CRT (ecto-CRT) on apoptotic or pre-apoptotic cells serves as an “eat me” signal that can promote phagocytosis. In this study, we observed the biphasic (early transient and late sustained) increase of ecto-CRT on HT-29 cells after treatment with oxaliplatin (L-OHP). To investigate the role of ecto-CRT that accumulates in the early and late phases as “eat me” signals, we examined the phagocytosis of HT-29 cells by macrophage-like cells and dendritic cell (DC) -like cells prepared from THP-1 cells. The results indicated that the early ecto-CRT-expressed cells were phagocytosed by immature DC-like cells, and the late ecto-CRT-expressed cells were phagocytosed primarily by macrophage-like cells, while mature DC-like cells did not respond to the either class of ecto-CRT-expressed cells. Both types of phagocytotic events were inhibited by CRT Blocking Peptide, suggesting that such events depended on the ecto-CRT. Our results suggested that the early increase of ecto-CRT is related to phagocytosis as part of immunogenic cell death (ICD), while the late increase of ecto-CRT is related to the removal of apoptotic cells by macrophages.

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Oxaliplatin induced the early transient and late sustained increases of ecto-CRT.

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The early ecto-CRT-expressed cells were phagocytosed by immature DC-like cells.

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The late ecto-CRT-expressed cells were phagocytosed by macrophage-like cells.

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The early and late increases in ecto-CRT may play distinct roles in phagocytosis.

Pt(II)-NHC Complex Induces ROS-ERS-Related DAMP Balance to Harness Immunogenic Cell Death in Hepatocellular Carcinoma

Immunogenic cell death (ICD) can engage a specific immune response and establish a long-term immunity in hepatocellular carcinoma (HCC). Herein, we design and synthesize a series of Pt(II)-N-heterocyclic carbene (Pt(II)-NHC) complexes derived from 4,5-diarylimidazole, which show strong anticancer activities in vitro. Among them, 2c displays much higher anticancer activities than cisplatin and other Pt(II)-NHC complexes, especially in HCC cancer cells. In addition, we find that 2c is a type II ICD inducer, which can successfully induce endoplasmic reticulum stress (ERS) accompanied by reactive oxygen species (ROS) generation and finally lead to the release of damage-associated molecular patterns (DAMPs) in HCC cells. Importantly, 2c shows a great anti-HCC potential in a vaccination mouse model and leads to the in vivo immune cell activation in the CCl4-induced liver injury model.

Redirecting Chemotherapeutics to the Endoplasmic Reticulum Increases Tumor Immunogenicity and Potentiates Anti-PD-L1 Therapy

The endoplasmic reticulum (ER) in cancer cells has been considered as a pharmacological target. Still, the effects of a ER-targeted system remain less investigated, due to the fact that most chemo-drugs take actions in the nucleus. Here, it is demonstrated that ER-targeted delivery of doxorubicin (DOX), a typically nucleus-tropic-and-acting agent, attenuates its original effect on cytotoxicity while generating new functions favorable for immune activation. First, a library of DOX derivatives with variable ER-targeting abilities is synthesized. The results reveal that higher ER-targeting efficiency correlates with greater ER stress. As compared with naïve drug, ER-targeted DOX considerably alters the mode of action from nuclear DNA damage-associated cytotoxicity to ER stress-mediated calreticulin exposure. Consequently, ER-targeted DOX decreases cytotoxicity but increases the capability to induce immunogenic cell death (ICD). Therefore, a platform combining naïve and ER-targeted DOX is constructed for in vivo application. Conventional polymer-DOX conjugate inhibits tumor growth by exerting a direct killing effect, and ER-targeted polymer-DOX conjugate suppresses residual tumors by eliciting ICD-associated immunity, together resulting in considerable tumor regression. In addition, simultaneous inhibition of adaptive PD-L1 enrichment (due to negative-feedback to ICD induction) further leads to greater therapeutic outcome. Collectively, ER-targeted therapy can enhance anticancer efficacy by promoting ICD-associated immunotherapy, and potentiating chemotherapy and checkpoint blockade therapy.

Semiconducting Polymer Nano-regulators with Cascading Activation for Photodynamic Cancer Immunotherapy

Combination photoimmunotherapy holds promise for tumor suppression; however, smart phototherapeutic agents that only activate their immunotherapeutic action in tumor have been rarely developed, which have the potential advantage of reduced side effect. Herein, we report a semiconducting polymer nano-regulator (SPN T ) with cascading activation for combinational photodynamic immunotherapy of cancer. SPN T  comprises an immunoregulator (M-Trp:  1-methyltryptophan ) conjugating to the side chain of semiconducting polymer backbone using an apoptotic biomarker-cleavable linker. Under near-infrared (NIR) laser irradiation, SPN T  produces singlet oxygen ( 1 O 2 ) to cause  immunogenic apoptosis . Concurrently, the upregulation of apoptotic biomarker triggers the specific cleavage of M-Trp from SPN T , leading to specific intratumoral immunotherapeutic activation. Released M-Trp inhibits  indoleamine 2,3-dioxygenase (IDO) activity, and thus decreases regulatory T cells (Tregs) formation and drives cytotoxic T lymphocytes (CTLs) infiltration. SPN T -mediated combination photodynamic immunotherapy thus reprograms the tumor immune microenvironment (TIME), resulting in efficient suppression of both primary and distant tumors, and inhibition of lung metastasis.

Characterization of the AGR2 interactome uncovers new players of Protein Disulfide Isomerase network in cancer cells

Anterior gradient 2 (AGR2) is an endoplasmic reticulum (ER)-resident protein disulfide isomerase (PDI) known to be overexpressed in many human epithelial cancers and is involved in cell migration, cellular transformation, angiogenesis, and metastasis. This protein inhibits the activity of the tumor suppressor p53, and its expression levels can be used to predict cancer patient outcome. However, the precise network of AGR2-interacting partners and clients remains to be fully characterized. Herein, we used label-free quantification and also stable isotope labeling with amino acids in cell culture–based LC–MS/MS analyses to identify proteins interacting with AGR2. Functional annotation confirmed that AGR2 and its interaction partners are associated with processes in the ER that maintain intracellular metabolic homeostasis and participate in the unfolded protein response, including those associated with changes in cellular metabolism, energy, and redox states in response to ER stress. As a proof of concept, the interaction between AGR2 and PDIA3, another ER-resident PDI, was studied in more detail. Pathway analysis revealed that AGR2 and PDIA3 play roles in protein folding in ER, including post-translational modification and in cellular response to stress. We confirmed the AGR2–PDIA3 complex formation in cancer cells, which was enhanced in response to ER stress. Accordingly, molecular docking characterized potential quaternary structure of this complex; however, it remains to be elucidated whether AGR2 rather contributes to PDIA3 maturation in ER, the complex directly acts in cellular signaling, or mediates AGR2 secretion. Our study provides a comprehensive insight into the protein–protein interaction network of AGR2 by identifying functionally relevant proteins and related cellular and biochemical pathways associated with the role of AGR2 in cancer cells.

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LC–MS/MS analysis of AGR2-interacting proteins in T47D and H1299 cells.

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About 15 overlapping AGR2 interactors, including PDIA3 and PDIA6, were identified in both cell lines.

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PDI family members represent the key part of the network.

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AGR2–PDIA3 interaction is even stronger under ER stress.

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AGR2–PDIA3 complex formation supports extracellular secretion of AGR2.

Increased CD47 and MHC Class I Inhibitory Signals Expression in Senescent CD1 Primary Mouse Lung Fibroblasts

Cellular senescence is more than a proliferative arrest in response to various stimuli. Senescent cells (SC) participate in several physiological processes, and their adequate removal is essential to maintain tissue and organism homeostasis. However, SC accumulation in aging and age-related diseases alters the tissue microenvironment leading to deterioration. The immune system clears the SC, but the specific scenarios and mechanisms related to recognizing and eliminating them are unknown. Hence, we aimed to evaluate the existence of three regulatory signals of phagocytic function, CD47, major histocompatibility complex class I (MHC-I), and calreticulin, present in the membrane of SC. Therefore, primary fibroblasts were isolated from CD1 female mice lungs, and stress-induced premature senescence (SIPS) was induced with hydrogen peroxide. Replicative senescence (RS) was used as a second senescent model. Our results revealed a considerable increment of CD47 and MHC-I in RS and SIPS fibroblasts. At the same time, no significant changes were found in calreticulin, suggesting that those signals might be associated with evading immune system recognition and thus averting senescent cells clearance.

Ultrasound (US)-activated redox dyshomeostasis therapy reinforced by immunogenic cell death (ICD) through a mitochondrial targeting liposomal nanosystem

Introduction: An imbalance in redox homeostasis consistently inhibits tumor cell proliferation and further causes tumor regression. Thus, synchronous glutaminolysis inhibition and intracellular reactive oxygen (ROS) accumulation cause severe redox dyshomeostasis, which may potentially become a new therapeutic strategy to effectively combat cancer. Methods: Mitochondrial-targeting liposomal nanoparticles (abbreviated MLipRIR NPs) are synthesized by the encapsulation of R162 (inhibitor of glutamate dehydrogenase 1 [GDH1]) and IR780 (a hydrophobic sonosensitizer) within the lipid bilayer, which are exploited for ultrasound (US)-activated tumor dyshomeostasis therapy reinforced by immunogenic cell death (ICD). Results: R162 released from MLipRIR NPs disrupts the glutaminolysis pathway in mitochondria, resulting in downregulated enzymatic activity of glutathione peroxidase (GPx). In addition, loaded IR780 can generate high levels of ROS under US irradiation, which not only interrupts mitochondrial respiration to induce apoptosis but also consumes local glutathione (GSH). GSH depletion accompanied by GPx deactivation causes severe ferroptosis of tumor cells through the accumulation of lipid peroxides. Such intracellular redox dyshomeostasis effectively triggers immunogenic cell death (ICD), which can activate antitumor immunity for the suppression of both primary and distant tumors with the aid of immune checkpoint blockade. Conclusions: Taking advantage of multimodal imaging for therapy guidance, this nanoplatform may potentiate systemic tumor eradication with high certainty. Taken together, this state-of-the-art paradigm may provide useful insights for cancer management by disrupting redox homeostasis.

Immunogenic Cell Death Induction by Ionizing Radiation

Immunogenic cell death (ICD) is a form of regulated cell death (RCD) induced by various stresses and produces antitumor immunity via damage-associated molecular patterns (DAMPs) release or exposure, mainly including high mobility group box 1 (HMGB1), calreticulin (CRT), adenosine triphosphate (ATP), and heat shock proteins (HSPs). Emerging evidence has suggested that ionizing radiation (IR) can induce ICD, and the dose, type, and fractionation of irradiation influence the induction of ICD. At present, IR-induced ICD is mainly verified in vitro in mice and there is few clinical evidence about it. To boost the induction of ICD by IR, some strategies have shown synergy with IR to enhance antitumor immune response, such as hyperthermia, nanoparticles, and chemotherapy. In this review, we focus on the molecular mechanisms of ICD, ICD-promoting factors associated with irradiation, the clinical evidence of ICD, and immunogenic forms of cell death. Finally, we summarize various methods of improving ICD induced by IR.