Radiation-induced small extracellular vesicles as "carriages" promote tumor antigen release and trigger antitumor immunity

Computational studies for the development of extracellular vesicle-based biosensors

Cancer affects millions of people, and early detection and efficient treatment are two strong levers to hurdle this disease. Recent studies on exosomes, a subset of extracellular vesicles, have deliberately shown the potential to function as a biomarker or treatment tool, thereby attracting the attention of researchers who work on developing biosensors. Due to the ability of computational methods to predict of the behavior of biomolecules, the combination of experimental and computational methods would enhance the analytical performance of the biosensor, including sensitivity, accuracy, and specificity, even detecting such vesicles from bodily fluids. In this regard, the role of computational methods such as molecular docking, molecular dynamics simulation, and density functional theory is overviewed in the development of biosensors. This review highlights the investigations and studies that have been reported using these methods to design exosome-based biosensors. This review concludes with the role of the quantum mechanics/molecular mechanics method in the investigation of chemical processes of biomolecular systems and the deficiencies in using this approach to develop exosome-based biosensors. In addition, the artificial intelligence theory is explained briefly to show its importance in the study of these biosensors.

The role of cGAS-STING in remodeling the tumor immune microenvironment induced by radiotherapy

The activation of the cGAS-STING pathway occurs when tumor cell DNA is damaged by ionizing radiation. Once triggered, this pathway reshapes the tumor immune microenvironment by promoting the maturation, activation, polarization, and immune-killing capacity of immune cells, as well as by inducing the release of interferons and the expression of immune-related genes. In addition, the gut microbiota and various mechanisms of programmed cell death interact with the cGAS-STING pathway, further influencing its function in remodeling the immune microenvironment after radiotherapy. Therefore, investigating the mechanisms of the cGAS-STING pathway in reshaping the tumor immune microenvironment post-radiotherapy can not only optimize the efficacy of combined radiotherapy and immunotherapy but also provide new research directions and potential targets for cancer treatment.

Propensity score analysis of high-dose rate brachytherapy, immune checkpoint inhibitors, and docetaxel in second-line advanced NSCLC treatment

This study evaluated the efficacy and safety of combining high-dose-rate brachytherapy, immune checkpoint inhibitors, and docetaxel as second-line treatment for advanced NSCLC, given the poor prognosis after first-line therapy. We conducted a single-center, retrospective, propensity score-matched study comparing HDR brachytherapy plus ICIs and docetaxel (study group) versus ICIs plus docetaxel (control group) in patients with advanced NSCLC who progressed after prior treatment without known driver gene mutations or uninvestigated mutation status. After propensity score matching, 21 patients were included in each group. The study group had a higher ORR (42.9% vs. 28.6%). Median OS was 18.6 months for the study group and 12.8 months for the control group (HR 0.45, 95% CI 0.20-0.85, P = 0.042). Median PFS was 8.6 vs. 5.6 months (HR   0.29, 95% CI 0.15-0.55, P < 0.001). The DCR was higher in the study group (71.4% vs. 61.9%). Treatment-related AEs were manageable, with no significant increase in grade 3/4 toxicities in the study group. Results suggest that combining high-dose rate brachytherapy, immune checkpoint inhibitors, and docetaxel may improve survival and response rates in advanced NSCLC after first-line therapy. Prospective randomized trials are necessary to confirm these findings and validate the strategy's effectiveness.

Extracellular vesicles as the common denominator among the 7 Rs of radiobiology: From the cellular level to clinical practice

Extracellular vesicles (EVs) are lipid-bound particles released by tumor cells and widely explored in cancer development, progression, and treatment response, being considered as valuable components to be explored as biomarkers or cellular targets to modulate the effect of therapies. The mechanisms underlying the production and profile of EVs during radiotherapy (RT) require addressing radiobiological aspects to determine cellular responses to specific radiation doses and fractionation. In this review, we explore the role of EVs in the 7 Rs of radiobiology, known as the molecular basis of a biological tissue response to radiation, supporting EVs as a shared player in all the seven processes. We also highlight the relevance of EVs in the context of liquid biopsy and resistance to immunotherapy, aiming to establish the connection and utility of EVs as tools in contemporary and precision radiotherapy.

sEV-mediated intercellular transformation from MGAT4AHigh to MGAT4ALow tumor cells via the HOTAIRM1/miR-196b-5p axis promotes apoptosis resistance in CTCL

ncRNAs encapsulated in small extracellular vesicles (sEVs) facilitate intercellular communication and are associated with tumor progression. lncRNA-HOTAIRM1 is aberrantly expressed in various cancers. However, HOTAIRM1 expression and its downstream ceRNA network in CTCL remains unclear. In this study, we found that HOTAIRM1 was reduced in CTCL. Elevated HOTAIRM1 inhibited proliferation and induced apoptosis in vitro, resulting in reduced in vivo tumorigenic capacity. Whole-transcriptome sequencing and scRNA-Seq confirmed that differential expression of HOTAIRM1/miR-196b-5p/MGAT4A axis induces apoptosis resistance in CTCL. Mechanistically, reduced MGAT4A expression in CTCL leads to decreased N-glycosylation modification of membrane proteins and reduced Galectin-1 affinity, thereby inducing partial resistance to Galectin-1-induced apoptosis. Meanwhile, benign CD4 + T cells show sensitivity to Galectin-1-induced apoptosis due to their relatively higher MGAT4A expression. Furthermore, MGAT4ALow CTCL tumor cells transformed MGAT4AHigh CD4+ benign cells into MGAT4ALow cells by secreting sEVs containing miR-196b-5p, thereby reducing Galectin-1 binding and inducing apoptosis resistance. Engineered sEVs from HOTAIRM1-overexpressing cells contain elevated HOTAIRM1, which can specifically target malignant T cells, with reduced miR-196b-5p and increased MGAT4A, demonstrating apoptosis-inducing and tumor-suppressive effects in CTCL. This study identified changes in HOTAIRM1/miR-196b-5p/MGAT4A axis and N-glycosylation modifications in CTCL. Engineered HOTAIRM1-loaded sEVs demonstrated promising targeting and therapeutic effects in CTCL.

Navigating Glioma Complexity: The Role of Abnormal Signaling Pathways in Shaping Future Therapies

Gliomas are a type of highly heterogeneous and invasive central nervous system tumor. Traditional treatment methods have limited efficacy, and the prognosis for patients remains poor. Recent studies have revealed the crucial roles of several abnormal signaling pathways in the pathogenesis of gliomas, including the Receptor Tyrosine Kinase/Rat Sarcoma Virus Oncogene/Phosphatidylinositol-3-Kinase (RTK/RAS/PI3K) pathway, the Wingless-Related Integration Site/β-Catenin (Wnt/β-Catenin) pathway, the Hippo/YAP (Hippo/Yes-associated protein) pathway, and the Slit/Robo (Slit Guidance Ligands/Roundabout) signaling pathway. These pathways play extremely vital roles in tumor proliferation, invasion, and treatment resistance. This article comprehensively and systematically reviews the molecular mechanisms of these signaling pathways, deeply summarizing the research progress of various treatment strategies, including targeted inhibitors, gene therapy, and nanomedicine against them. Moreover, the combination of targeted therapy and personalized treatment regimens is expected to overcome the current treatment bottleneck and provide a more favorable survival prognosis for glioblastoma patients.

Tumor-derived extracellular vesicles: key drivers of immunomodulation in breast cancer

Breast cancer (BC) remains a significant global health challenge characterized by its heterogeneity and treatment complexities. Extracellular vesicles (EVs) are small membranous particles released by cells, facilitating intercellular communication by transporting bioactive molecules such as proteins, lipids, and nucleic acids. Tumor-derived EVs have emerged as pivotal regulators in the tumor microenvironment (TME) and drivers of BC progression. These EVs carry diverse cargoes of bioactive molecules, influencing critical processes such as immune modulation, angiogenesis, and metastasis. By altering the behaviors of immune cells including macrophages, dendritic cells, and T cells, tumor-derived EVs contribute to immune evasion and tumor growth. Furthermore, Tumor-derived EVs play a role in mediating drug resistance, impacting the effectiveness of therapeutic interventions. Understanding the multifaceted roles of BC tumor-derived EVs is essential for the development of innovative therapeutic strategies. Targeting pathways mediated by EVs holds promise for enhancing the efficacy of cancer treatments and improving patient outcomes. This comprehensive review provides insights into the intricate interactions of tumor-derived EVs in immune modulation and BC progression, highlighting potential therapeutic targets and avenues for novel cancer therapies.

Safety and Efficacy of Radiotherapy Combined With Sintilimab in Advanced NSCLC Patients Who Progressed on First or Second Line Therapy: A Prospective, Multiple Center, and Single-Arm Study

BACKGROUND

This study explored the safety and efficacy of combining radiotherapy with sintilimab in non-small cell lung cancer (NSCLC) patients who have progressed after first or second-line therapy.

METHODS

In this multicenter, single-arm trial, patients with NSCLC who had progressed after first or second-line therapy were enrolled. Participants received hypofractionated stereotactic body radiotherapy (SBRT) (requiring a single-site biological dose of more than 30 Gy or planned to reach 30 Gy) followed by sintilimab every 3 weeks until disease progression or unacceptable toxicity occurred.

RESULTS

From March 1, 2019, to July 27, 2023, 14 patients were enrolled across two centers. The cohort included 64.3% males and 35.7% females, with a median age of 67 years (range 57-73 years). All participants completed radiation therapy and received at least one cycle of sintilimab. The overall response rate (ORR) was 21.4% (3/14) and the disease control rate (DCR) was 71.4% (10/14). The absent radiation response (ARR) was 14.3% (2/14). The median PFS was 4.17 months (95% CI: 1.15-8.69 months), with a 6-month PFS rate of 42.9%. The median OS was 16.17 months (95% CI: 11.69-20.64 months). Overall, 10 patients (71.4%) experienced at least one treatment-emergent adverse event (TEAE). Grade 3 adverse events included one case each of immune-related myocarditis, thrombocytopenia, and checkpoint inhibitor pneumonitis (CIP). Four patients (28.6%) had immune-related adverse events (irAEs) including skin rash and pruritus (2/14, grade 1), immune-related myocarditis (1/14, grade 3), and CIP (1/14, grade 3).

CONCLUSIONS

Radiotherapy combined with sintilimab for NSCLC patients who progressed after first-or second-line therapy showed promising efficacy outcomes.

Extracellular vesicles in tumor immunity: mechanisms and novel insights

Extracellular vesicles (EVs), nanoscale vesicles secreted by cells, have attracted considerable attention in recent years due to their role in tumor immunomodulation. These vesicles facilitate intercellular communication by transporting proteins, nucleic acids, and other biologically active substances, and they exhibit a dual role in tumor development and immune evasion mechanisms. Specifically, EVs can assist tumor cells in evading immune surveillance and attack by impairing immune cell function or modulating immunosuppressive pathways, thereby promoting tumor progression and metastasis. Conversely, they can also transport and release immunomodulatory factors that stimulate the activation and regulation of the immune system, enhancing the body's capacity to combat malignant diseases. This dual functionality of EVs presents promising avenues and targets for tumor immunotherapy. By examining the biological characteristics of EVs and their influence on tumor immunity, novel therapeutic strategies can be developed to improve the efficacy and relevance of cancer treatment. This review delineates the complex role of EVs in tumor immunomodulation and explores their potential implications for cancer therapeutic approaches, aiming to establish a theoretical foundation and provide practical insights for the advancement of future EVs-based cancer immunotherapy strategies.

Emerging role of exosomes in cancer therapy: progress and challenges

This review highlights recent progress in exosome-based drug delivery for cancer therapy, covering exosome biogenesis, cargo selection mechanisms, and their application across multiple cancer types. As small extracellular vesicles, exosomes exhibit high biocompatibility and low immunogenicity, making them ideal drug delivery vehicles capable of efficiently targeting cancer cells, minimizing off-target damage and side effects. This review aims to explore the potential of exosomes in cancer therapy, with a focus on applications in chemotherapy, gene therapy, and immunomodulation. Additionally, challenges related to exosome production and standardization are analyzed, highlighting the importance of addressing these issues for their clinical application. In conclusion, exosome-based drug delivery systems offer promising potential for future cancer therapies. Further research should aim to enhance production efficiency and facilitate clinical translation, paving the way for innovative cancer treatment strategies.

Case report: Long term remission of metastatic sinonasal NUT carcinoma after palliative radiotherapy and immunotherapy in an elderly patient

NUT carcinoma (NC) is an extremely rare, aggressive malignancy characterized by chromosomal rearrangements in the NUTM1 (nuclear protein in testis) gene. It usually affects younger patients with a median age of diagnosis at 23 years old. The mainstay of treatment consists of combination chemotherapy, surgical resection, and high dose radiation. However, prognosis remains dismal with reported median overall survival of 6.7 months. Literature reporting on use of immunotherapy in head and neck NC is limited. Prolonged remission without aggressive multimodality therapy is rare. We report a case of a 87-year-old woman with metastatic sinonasal NC treated with palliative radiotherapy and pembrolizumab who achieved sustained response 2 years from diagnosis.

PEARL: A Phase Ib/II Biomarker Study of Adding Radiation Therapy to Pembrolizumab Before Neoadjuvant Chemotherapy in Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer

PURPOSE

To assess safety and immune biomarkers after preoperative radiation therapy (RT) and anti-PD1 therapy in breast cancer.

MATERIALS AND METHODS

A phase I/IIb trial of pembrolizumab with RT was conducted in patients with triple-negative breast cancer (TNBC) and hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer. All received pembrolizumab followed by a second cycle + RT (anti-PD1/RT) of 24 Gy/three daily fractions delivered to the breast tumor and then neoadjuvant chemotherapy (NAC). Blood and tumor biopsies were obtained at baseline, after anti-PD1, and after anti-PD-RT. Coprimary end points were safety and change in tumor-infiltrating lymphocytes (TILs). Secondary end points were pathologic complete response (pCR), residual cancer burden (RCB) rates, and event-free survival (EFS).

RESULTS

Sixty-six patients with stage I-III breast cancer (54 TNBC, 12 HR+/HER2-) were enrolled. The median follow-up was 32 months. Safety end point was met. Incidence of grade ≥3 toxicities was 41%. The pCR rate was 59.2%, 33.3%, and 54.5% for the TNBC, HR+/HER2-, and entire cohort, respectively. A total of 77.8% of TNBC and 41.6% of HR+/HER2- had a near pCR (RCB 0-1). The 3-year EFS was 80%. In the entire cohort, PD-L1 expression increased after anti-PD1 (median Combined Positive Score [CPS], 7.49-23.20; 95% CI, -41.88 to -6.30; P = .044) and anti-PD1/RT (median CPS, 7.49-23.41; 95% CI, -41.88 to -6.30; P = .009), compared with baseline. In TNBC, adding RT to anti-PD1 significantly decreased TILs (28.9%-17.1%; 95% CI, 2.46 to 21.09; P = .014). Baseline TILs correlated with PD-L1 expression and TNF-a.

CONCLUSION

Preoperative RT with pembrolizumab is safe and results in high pCR rates and 3-year EFS, despite the lack of pembrolizumab during NAC. PD-L1 and TILs may be predictive biomarkers for preoperative anti-PD1/RT response. Reduction in TILs after adding RT to anti-PD1 highlights the importance of treatment sequencing.

Extracellular vesicles role in radio(nuclide)therapy

Conventional radiation therapy can restore the ability of cells to undergo immunogenic cell death. Recent preclinical studies suggest that targeted radionuclide therapy, which delivers radiation to tumors at a continuous low dose rate, also stimulates the immune system and offers a promising approach for overcoming resistance to immune checkpoint inhibitors. In this context, we examined the growing body of preclinical and clinical findings showing that the immune system can be activated by the release of extracellular vesicles from irradiated cells, contributing to the antitumor immunity.

Role of exosomes in modulating non-small cell lung cancer radiosensitivity

Non-small cell lung cancer (NSCLC) constitutes a significant proportion of lung cancer cases, and despite advancements in treatment modalities, radiotherapy resistance remains a substantial hurdle in effective cancer management. Exosomes, which are small vesicles secreted by cells, have emerged as pivotal players in intercellular communication and influence various biological processes, including cancer progression and the response to therapy. This review discusses the intricate role of exosomes in the modulation of NSCLC radiosensitivity. The paper focuses on NSCLC and highlights how tumor-derived exosomes contribute to radioresistance by enhancing DNA repair, modulating immune responses, and altering the tumor microenvironment. We further explore the potential of mesenchymal stem cell-derived exosomes to overcome radiotherapy resistance and their potential as biomarkers for predicting therapeutic outcomes. Understanding the mechanisms by which exosomes affect radiotherapy can provide new avenues for enhancing treatment efficacy and improving the survival rates of patients with NSCLC.

Extracellular vesicle autoantibodies

Autoantibodies are immunoglobulin proteins produced by autoreactive B cells responding to self-antigens. Extracellular vesicles (EVs) are membranous structures released by almost all types of cells and extensively distributed in various biological fluids. Studies have indicated that EVs loaded with self-antigens not only play important roles in antigen presentation and autoantibody production but can also form functional immune complexes with autoantibodies (termed EV autoantibodies). While numerous papers have summarized the production and function of pathogenic autoantibodies in diseases, especially autoimmune diseases, reviews on EV autoantibodies are rare. In this review, we outline the existing knowledge about EVs, autoantibodies, and EV antigens, highlighting the formation of EV autoantibodies and their functions in autoimmune diseases and cancers. In conclusion, EV autoantibodies may be involved in the occurrence of disease(s) and also serve as potential non-invasive markers that could help in the diagnosis and/or prognosis of disease. Additional studies designed to define in more detail the molecular characteristics of EV autoantibodies and their contribution to disease are recommended.

The effects of immune checkpoint inhibitors vs. chemotherapy combined with brain radiotherapy in non-small cell lung cancer patients with brain metastases

BACKGROUND

Non-small cell lung cancer (NSCLC) is a prevalent form of cancer, often leading to brain metastases (BM) and a significant decline in patient prognosis. Whether immune checkpoint inhibitors (ICIs) combined with brain radiotherapy is superior to conventional chemotherapy combined with brain radiotherapy in those patients remains to be explored.

MATERIALS AND METHODS

Our study enrolled 161 NSCLC patients with BM who underwent either ICIs combined with brain radiotherapy or chemotherapy combined with brain radiotherapy. End points included overall survival (OS), progression-free survival (PFS), intracranial PFS (IPFS), and extracranial PFS (EPFS). Univariate and multivariate Cox regressions were employed to identify prognostic risk variables.

RESULTS

Patients receiving ICIs combined with brain radiotherapy exhibited significantly longer OS compared to those receiving chemotherapy combined with brain radiotherapy (34.80 months vs. 17.17 months, P = 0.005). In the Cox regression analysis, chemotherapy combined with brain radiotherapy (HR, 1.82; 95% CI, 1.09-3.05; P = 0.023), smoking (HR, 1.75; 95% CI, 1.02-2.99; P = 0.043) and squamous cell carcinoma (HR, 2.59; 95% CI, 1.31-5.13; P = 0.006) were associated with a worse prognosis. After propensity score matching (PSM), this finding remained consistent with before PSM (43.73 months vs. 17.17 months, P = 0.018). Squamous cell carcinoma (HR, 2.46; 95% CI, 1.15-5.26; P = 0.021) and CT + RT (HR, 2.11; 95% CI, 1.15-3.88; P = 0.016) were associated with a less favorable prognosis.

CONCLUSION

The study suggests that the combination of ICIs and brain radiotherapy provides superior OS for NSCLC patients with BM, compared to the chemotherapy combined with brain radiotherapy.

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.

Extracellular vesicles in cancer: golden goose or Trojan horse

Intercellular communication can be mediated by direct cell-to-cell contact and indirect interactions through secretion of soluble chemokines, cytokines, and growth factors. Extracellular vesicles (EVs) have emerged as important mediators of cell-to-cell and cell-to-environment communications. EVs from tumor cells, immune cells, and stromal cells can remodel the tumor microenvironment and promote cancer cell survival, proliferation, metastasis, immune evasion, and therapeutic resistance. Most importantly, EVs as natural nanoparticles can be manipulated to serve as a potent delivery system for targeted cancer therapy. EVs can be engineered or modified to improve their ability to target tumors and deliver therapeutic substances, such as chemotherapeutic drugs, nucleic acids, and proteins, for the treatment of cancer. This review provides an overview of the biogenesis and recycling of EVs, discusses their roles in cancer development, and highlights their potential as a delivery system for targeted cancer therapy.

Cdc42 deletion yielded enamel defects by disrupting mitochondria and producing reactive oxygen species in dental epithelium

Developmental defects of enamel are common due to genetic and environmental factors before and after birth. Cdc42, a Rho family small GTPase, regulates prenatal tooth development in mice. However, its role in postnatal tooth development, especially enamel formation, remains elusive. Here, we investigated Cdc42 functions in mouse enamel development and tooth repair after birth. Cdc42 showed highly dynamic temporospatial patterns in the developing incisors, with robust expression in ameloblast and odontoblast layers. Strikingly, epithelium-specific Cdc42 deletion resulted in enamel defects in incisors. Ameloblast differentiation was inhibited, and hypomineralization of enamel was observed upon epithelial Cdc42 deletion. Proteomic analysis showed that abnormal mitochondrial components, phosphotransferase activity, and ion channel regulator activity occurred in the Cdc42 mutant dental epithelium. Reactive oxygen species accumulation was detected in the mutant mice, suggesting that abnormal oxidative stress occurred after Cdc42 depletion. Moreover, Cdc42 mutant mice showed delayed tooth repair and generated less calcified enamel. Mitochondrial dysfunction and abnormal oxygen consumption were evidenced by reduced Apool and Timm8a1 expression, increased Atp5j2 levels, and reactive oxygen species overproduction in the mutant repair epithelium. Epithelium-specific Cdc42 deletion attenuated ERK1/2 signaling in the labial cervical loop. Aberrant Sox2 expression in the mutant labial cervical loop after clipping might lead to delayed tooth repair. These findings suggested that mitochondrial dysfunction, up-regulated oxidative stress, and abnormal ion channel activity may be among multiple factors responsible for the observed enamel defects in Cdc42 mutant incisors. Overall, Cdc42 exerts multidimensional and pivotal roles in enamel development and is particularly required for ameloblast differentiation and enamel matrix formation.

Boron Neutron Capture Therapy-Derived Extracellular Vesicles via DNA Accumulation Boost Antitumor Dendritic Cell Vaccine Efficacy

Radiated tumor cell-derived extracellular vesicles (RT-EVs) encapsulate abundant DNA fragments from irradiated tumor cells, in addition to acting as integrators of multiple tumor antigens. Accumulating evidence indicates these DNA fragments from damaged cells are involved in downstream immune responses, but most of them are degraded in cells before incorporation into derived RT-EVs, thus the low abundance of DNA fragments limits immune responses of RT-EVs. Here, this study found that different radiations affected fates of DNA fragments in RT-EVs. Boron neutron capture therapy (BNCT) induced DNA accumulation in RT-EVs (BEVs) by causing more DNA breaks and DNA oxidation resisting nuclease degradation. This is attributed to the high-linear energy transfer (LET) properties of alpha particles from the neutron capture reaction of 10B. When being internalized by dendritic cells (DCs), BEVs activated the DNA sensing pathway, resulting in functional enhancements including antigen presentation, migration capacity, and cytokine secretion. After vaccination of the BEVs-educated DCs (BEV@BMDCs), the effector T cells significantly expanded and infiltrated into tumors, suggesting robust anti-tumor immune activation. BEV@BMDCs not only effectively inhibited the primary tumor growth and metastasis formation but also elicited long-term immune memory. In conclusion, a successful DC vaccine is provided as a promising candidate for tumor vaccine.

Extracellular vesicles and the "six Rs" in radiotherapy

Over half of patients with cancer receive radiation therapy during the course of their disease. Decades of radiobiological research have identified 6 parameters affecting the biological response to radiation referred to as the 6 "Rs": Repair, Radiosensitivity, Repopulation, Redistribution, Reoxygenation, and Reactivation of the anti-tumour immune response. Extracellular Vesicles (EVs) are small membrane-bound particles whose multiple biological functions are increasingly documented. Here we discuss the evidence for a role of EVs in the orchestration of the response of cancer cells to radiotherapy. We highlight that EVs are involved in DNA repair mechanisms, modulation of cellular sensitivity to radiation, and facilitation of tumour repopulation. Moreover, EVs influence tumour reoxygenation dynamics, and play a pivotal role in fostering radioresistance. Last, we examine how EV-related strategies could be translated into novel strategies aimed at enhancing the efficacy of radiation therapy against cancer.

Impact of Radiation on Exosomes in Regulating Tumor Immune Microenvironment

Purpose

Exosomes have been shown to play a role in most, if not all, steps of cancer progression. We still lack a comprehensive understanding of the bidirectional communication of exosomes between tumor cells and immune cells. This article aims to explore how exosomes can influence cancer growth and how they are affected by radiation therapy.

Methods and Materials

We searched on PubMed and Web of Science on the impact of radiation on tumor derived exosomes and immune cell derived exosomes in tumor immune microenvironment. We screened all the related articles and summarized their main discoveries and important results.

Results

This article reviewed the effects of tumor derived exosomes and immune cell-derived exosomes on TME and tumor progression after radiotherapy, suggesting the dual effects of exosomes which may refer to clinical practice. Moreover, we retrospected the clinical applications based on tumor derived exosomes, including liquid biopsy, radio-resistance and drug delivery, and discussed the challenges and prospects.

Conclusions

Exosomes are important in cancer treatment, especially with radiation therapy. Learning more about them could lead to better treatments. However, there are still challenges to overcome. The review points out the need for more research in this area.

Radiation-induced exosomes promote oral squamous cell carcinoma progression via enhancing SLC1A5-glutamine metabolism

BACKGROUND

Radiotherapy (RT) can drive cancer cells to enter a state of cellular senescence in which cells can secrete senescence-associated secretory phenotype (SASP) and produce small extracellular vesicles (sEVs) to interact with cells in the tumor microenvironment (TME). Tumor-derived sEVs that are taken up by recipient cells contribute to cancer cell metabolic plasticity, resistance to anticancer therapy, and adaptation to the TME. However, how radiation-induced sEVs support oral squamous cell carcinoma (OSCC) progression remains unclear.

METHODS

Beta-galactosidase staining and SASP mRNA expression analysis were used to evaluate the senescence-associated activity of OSCC cells after irradiation. Nanoparticle tracking analysis was performed to identify radiation-induced sEVs. Liquid chromatography-tandem mass spectrometry (LC-MS) was used to explore changes in the levels of proteins in radiation-induced sEVs. Cell Counting Kit-8 and colony formation assays were performed to investigate the function of radiation-induced SASP and sEVs in vitro. A xenograft tumor model was established to investigate the functions of radiation-induced sEVs and V-9302 in vivo as well as the underlying mechanisms. Bioinformatics analysis was performed to determine the relationship between glutamine metabolism and OSCC recurrence.

RESULTS

We determined that the radiation-induced SASP triggered OSCC cell proliferation. Additionally, radiation-induced sEVs exacerbated OSCC cell malignancy. LC-MS/MS and bioinformatics analyses revealed that SLC1A5, which is a cellular receptor that participates in glutamine uptake, was significantly enriched in radiation-induced sEVs. In vitro and in vivo, inhibiting SLC1A5 could block the oncogenic effects of radiation-induced sEVs in OSCC.

CONCLUSION

Radiation-induced sEVs might promote the proliferation of unirradiated cancer cells by enhancing glutamine metabolism; this might be a novel molecular mechanism underlying radiation resistance in OSCC patients.

Lipid-based nanosystems: the next generation of cancer immune therapy

Immunotherapy has become an important part of the oncotherapy arsenal. Its applicability in various cancer types is impressive, as well as its use of endogenous mechanisms to achieve desired ends. However, off-target or on-target-off-tumor toxicity, limited activity, lack of control in combination treatments and, especially for solid tumors, low local accumulation, have collectively limited clinical use thereof. These limitations are partially alleviated by delivery systems. Lipid-based nanoparticles (NPs) have emerged as revolutionary carriers due to favorable physicochemical characteristics, with specific applications and strengths particularly useful in immunotherapeutic agent delivery. The aim of this review is to highlight the challenges faced by immunotherapy and how lipid-based NPs have been, and may be further utilized to address such challenges. We discuss recent fundamental and clinical applications of NPs in a range of areas and provide a detailed discussion of the main obstacles in immune checkpoint inhibition therapies, adoptive cellular therapies, and cytokine therapies. We highlight how lipid-based nanosystems could address these through either delivery, direct modulation of the immune system, or targeting of the immunosuppressive tumor microenvironment. We explore advanced and emerging liposomal and lipid nanoparticle (LNP) systems for nucleic acid delivery, intrinsic and extrinsic stimulus-responsive formulations, and biomimetic lipid-based nanosystems in immunotherapy. Finally, we discuss the key challenges relating to the clinical use of lipid-based NP immunotherapies, suggesting future research directions for the near term to realize the potential of these innovative lipid-based nanosystems, as they become the crucial steppingstone towards the necessary enhancement of the efficacy of immunotherapy.

Analysis of the clinical efficacy and safety of anti-PD-1 immune checkpoint inhibitors in locally advanced nasopharyngeal cancer

OBJECTIVE

To analyze the efficacy and adverse effects of anti-PD-1 immune checkpoint inhibitors aimed at nasopharyngeal carcinoma (NPC).

METHODS

During the first stage of the study, using 40 patients with stage III/IVa NPC treated with anti-PD-1 immune checkpoint inhibitors in combination with chemoradiotherapy as a first-line treatment (observation group) and 70 patients with NPC treated with chemoradiotherapy alone (control group). In the second stage of the study, 88 patients with NPC treated with immune checkpoint inhibitors were grouped according to the number of lines of immunotherapy, the number of times, and the types of application.

RESULTS

Observation of the short-term effects in the first stage indicated that the objective response rate (ORR) of the observation group and the control group against primary foci of NPC was 75.0% versus 40.0%; the mortality rate of the observation group was much lower than that of the control group. The overall first-line treatment evaluation of the observation vs. control groups were as follows: ORR (67.5% vs. 38.6%); median PFS (17.52 vs. 17.21 months); and median OS (18.68 vs. 18.14 months), respectively (p < 0.05). The second stage of the study had an ORR of 53.4%, and the efficacy of immunotherapy was related to staging, timing, and frequency.

CONCLUSION

Anti-PD-1 immune checkpoint inhibitors combined with chemoradiotherapy as the first-line treatment for nasopharyngeal carcinoma may improve patient outcomes significantly. Timing, frequency, and the type of immunotherapy exerted an effect on the efficacy of immunotherapy. Adverse effects that occurred during treatment were tolerable and controllable.

Environmental pollutants exposure-derived extracellular vesicles: crucial players in respiratory disorders

BACKGROUND

Individual exposure to environmental pollutants, as one of the most influential drivers of respiratory disorders, has received considerable attention due to its preventability and controllability. Considering that the extracellular vesicle (EV) was an emerging intercellular communication medium, recent studies have highlighted the crucial role of environmental pollutants derived EVs (EPE-EVs) in respiratory disorders.

METHODS

PubMed and Web of Science were searched from January 2018 to December 2023 for publications with key words of environmental pollutants, respiratory disorders and EVs.

RESULTS

Environmental pollutants could disrupt airway intercellular communication by indirectly stimulating airway barrier cells to secrete endogenous EVs, or directly transmitting exogenous EVs, mainly by biological pollutants. Mechanistically, EPE-EVs transferred specific contents to modulate biological functions of recipient cells, to induce respiratory inflammation and impair tissue and immune function, which consequently contributed to the development of respiratory diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, pulmonary hypertension, lung cancer and infectious lung diseases. Clinically, EVs could emerged as promising biomarkers and biological agents for respiratory diseases attributed by their specificity, convenience, sensibility and stability.

CONCLUSIONS

Further studies of EPE-EVs are helpful to understand the aetiology and pathology of respiratory diseases, and facilitate the precision respiratory medicine in risk screening, early diagnosis, clinical management and biotherapy.

Recent advances in therapeutic engineered extracellular vesicles

Extracellular vesicles (EVs) are natural particles secreted by living cells, which hold significant potential for various therapeutic applications. Native EVs have specific components and structures, allowing them to cross biological barriers, and circulate in vivo for a long time. Native EVs have also been bioengineered to enhance their therapeutic efficacy and targeting affinity. Recently, the therapeutic potential of surface-engineered EVs has been explored in the treatment of tumors, autoimmune diseases, infections and other diseases by ongoing research and clinical trials. In this review, we will introduce the modified methods of engineered EVs, summarize the application of engineered EVs in preclinical and clinical trials, and discuss the opportunities and challenges for the clinical translation of surface-engineered EVs.

Native and engineered extracellular vesicles: novel tools for treating liver disease

Liver diseases are classified as acute liver damage and chronic liver disease, with recurring liver damage causing liver fibrosis and progression to cirrhosis and hepatoma. Liver transplantation is the only effective treatment for end-stage liver diseases; therefore, novel therapies are required. Extracellular vesicles (EVs) are endogenous nanocarriers involved in cell-to-cell communication that play important roles in immune regulation, tissue repair and regeneration. Native EVs can potentially be used for various liver diseases owing to their high biocompatibility, low immunogenicity and tissue permeability and engineered EVs with surface modification or cargo loading could further optimize therapeutic effects. In this review, we firstly introduced the mechanisms and effects of native EVs derived from different cells and tissues to treat liver diseases of different etiologies. Additionally, we summarized the possible methods to facilitate liver targeting and improve cargo-loading efficiency. In the treatment of liver disease, the detailed engineered methods and the latest delivery strategies were also discussed. Finally, we pointed out the limitations and challenges of EVs for future development and applications. We hope that this review could provide a useful reference for the development of EVs and promote the clinical translation.

Analysing the Combined Effects of Radiotherapy and Chemokine Receptor 5 Antagonism: Complementary Approaches to Promote T Cell Function and Migration in Oesophageal Adenocarcinoma

The presence of an immunosuppressive tumour microenvironment in oesophageal adenocarcinoma (OAC) is a major contributor to poor responses. Novel treatment strategies are required to supplement current regimens and improve patient survival. This study examined the immunomodulatory effects that radiation therapy and chemokine receptor antagonism impose on T cell phenotypes in OAC with a primary goal of identifying potential therapeutic targets to combine with radiation to improve anti-tumour responses. Compared with healthy controls, anti-tumour T cell function was impaired in OAC patients, demonstrated by lower IFN-γ production by CD4+ T helper cells and lower CD8+ T cell cytotoxic potential. Such diminished T cell effector functions were enhanced following treatment with clinically relevant doses of irradiation. Interestingly, CCR5+ T cells were significantly more abundant in OAC patient blood compared with healthy controls, and CCR5 surface expression by T cells was further enhanced by clinically relevant doses of irradiation. Moreover, irradiation enhanced T cell migration towards OAC patient-derived tumour-conditioned media (TCM). In vitro treatment with the CCR5 antagonist Maraviroc enhanced IFN-γ production by CD4+ T cells and increased the migration of irradiated CD8+ T cells towards irradiated TCM, suggesting its synergistic therapeutic potential in combination with irradiation. Overall, this study highlights the immunostimulatory properties of radiation in promoting anti-tumour T cell responses in OAC and increasing T cell migration towards chemotactic cues in the tumour. Importantly, the CCR5 antagonist Maraviroc holds promise to be repurposed in combination with radiotherapy to promote anti-tumour T cell responses in OAC.

The influence of radiation-induced bystander effect in osteoblasts mediated by plasma-derived extracellular vesicles (EVs)

OBJECTIVES

Head and neck tumor patients may develop post-radiotherapy diseases after radiotherapy treatment. And radiotherapy can elicit radiation-induced bystander effect, wherein extracellular vesicles (EVs) play a crucial role. For normal parts of the body that have not been directly irradiated, the effect of EVs on them needs to be further explored. This study aims to investigate the functions of plasma-derived EVs in regulating normal osteoblasts during radiation-induced bystander effects.

METHODS AND MATERIALS

Rat plasma-derived EVs were isolated and identified firstly, followed by an evaluation of their intracellular biological effects on normal osteoblasts in vitro. Transcriptome sequencing analysis and confirmations were performed to identify potential mechanisms.

RESULTS

Irradiated plasma-derived EVs were found to enhance osteoblast proliferation, migration, and cell cycle progression, concurrently suppressing the expression of osteogenesis-related genes and proteins. Furthermore, these EVs attenuated the expression of osteogenesis and oxidative stress resistance related genes, while upregulating the PI3K-AKT pathway and intracellular reactive oxygen species in osteoblasts.

CONCLUSIONS

Irradiated plasma-derived EVs could alter the biological effects in osteoblasts, which is closely associated with the levels of GPX1 and the PI3K-AKT signaling pathway. This suggests that plasma-derived EVs serve as a crucial factor contributing to radiation-induced bystander effect in osteoblasts.

Engineered exosomes-based theranostic strategy for tumor metastasis and recurrence

Metastasis-associated processes are the predominant instigator of fatalities linked to cancer, wherein the pivotal role of circulating tumor cells lies in the resurgence of malignant growth. In recent epochs, exosomes, constituents of the extracellular vesicle cohort, have garnered attention within the field of tumor theranostics owing to their inherent attributes encompassing biocompatibility, modifiability, payload capacity, stability, and therapeutic suitability. Nonetheless, the rudimentary functionalities and limited efficacy of unmodified exosomes curtail their prospective utility. In an effort to surmount these shortcomings, intricate methodologies amalgamating nanotechnology with genetic manipulation, chemotherapy, immunotherapy, and optical intervention present themselves as enhanced avenues to surveil and intercede in tumor metastasis and relapse. This review delves into the manifold techniques currently employed to engineer exosomes, with a specific focus on elucidating the interplay between exosomes and the metastatic cascade, alongside the implementation of tailored exosomes in abating tumor metastasis and recurrence. This review not only advances comprehension of the evolving landscape within this domain but also steers the trajectory of forthcoming investigations.

Radiotherapy remodels the tumor microenvironment for enhancing immunotherapeutic sensitivity

Cancer immunotherapy has transformed traditional treatments, with immune checkpoint blockade being particularly prominent. However, immunotherapy has minimal benefit for patients in most types of cancer and is largely ineffective in some cancers (such as pancreatic cancer and glioma). A synergistic anti-tumor response may be produced through the combined application with traditional tumor treatment methods. Radiotherapy (RT) not only kills tumor cells but also triggers the pro-inflammatory molecules' release and immune cell infiltration, which remodel the tumor microenvironment (TME). Therefore, the combination of RT and immunotherapy is expected to achieve improved efficacy. In this review, we summarize the effects of RT on cellular components of the TME, including T cell receptor repertoires, different T cell subsets, metabolism, tumor-associated macrophages and other myeloid cells (dendritic cells, myeloid-derived suppressor cells, neutrophils and eosinophils). Meanwhile, non-cellular components such as lactate and extracellular vesicles are also elaborated. In addition, we discuss the impact of different RT modalities on tumor immunity and issues related to the clinical practice of combination therapy.

EISA in Tandem with ICD to Form In Situ Nanofiber Vaccine for Enhanced Tumor Radioimmunotherapy

Radiotherapy (RT) can produce a vaccine effect and remodel a tumor microenvironment (TME) by inducing immunogenic cell death (ICD) and inflammation in tumors. However, RT alone is insufficient to elicit a systemic antitumor immune response owing to limited antigen presentation, immunosuppressive microenvironment, and chronic inflammation within the tumor. Here, a novel strategy is reported for the generation of in situ peptide-based nanovaccines via enzyme-induced self-assembly (EISA) in tandem with ICD. As ICD progresses, the peptide Fbp-GD FD FD pY (Fbp-pY), dephosphorylated by alkaline phosphatase (ALP) forms a fibrous nanostructure around the tumor cells, resulting in the capture and encapsulation of the autologous antigens produced by radiation. Utilizing the adjuvant and controlled-release advantages of self-assembling peptides, this nanofiber vaccine effectively increases antigen accumulation in the lymph nodes and cross-presentation by antigen-presenting cells (APCs). In addition, the inhibition of cyclooxygenase 2 (COX-2) expression by the nanofibers promotes the repolarization of M2-macrophages into M1 and reduces the number of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) required for TME remodeling. As a result, the combination of nanovaccines and RT significantly enhances the therapeutic effect on 4T1 tumors compared with RT alone, suggesting a promising treatment strategy for tumor radioimmunotherapy.

Comparison of different adjuvant therapy regimen efficacies in patients with high risk of recurrence after radical resection of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) has a high recurrence rate even after radical surgery. Postoperative adjuvant transhepatic arterial chemoembolization (PA-TACE), postoperative adjuvant hepatic arterial infusion chemotherapy (PA-HAIC), postoperative adjuvant radiotherapy (PA-RT), and postoperative adjuvant molecular targeted therapy have been demonstrated to be effective in reducing the postoperative recurrence rate. The present network meta-analysis was conducted to compare the effects of PA-TACE, PA-HAIC, PA-RT and postoperative adjuvant molecular targeted therapy on the overall survival (OS) and disease-free survival (DFS) in HCC patients after radical resection and to determine the optimal treatment strategy.

METHODS

Network meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed, Embase, Cochrane Library, and Web of Science were used to collect eligible studies up to December 25, 2022. Studies related to PA-TACE, PA-HAIC, and postoperative adjuvant molecular targeted therapy after radical HCC resection was included. The endpoints were OS and DFS, and the effect size was determined using hazard ratio with a 95% confidence interval. R software and "gemtc" package were employed to analyze the results.

RESULTS

A total of 38 studies involving 7079 patients with HCC after radical resection were ultimately enrolled to be analyzed. Four postoperative adjuvant therapy measures and two oncology indicators were evaluated. In this study, OS-related investigations validated that PA-Sorafenib and PA-RT markedly enhanced the OS rates in patients after radical resection when compared to PA-TACE and PA-HAIC. However, statistical analysis revealed no significant difference between PA-Sorafenib and PA-RT, as well as PA-TACE and PA-HAIC. In the DFS-related investigations, PA-RT demonstrated superior efficacy over PA-Sorafenib, PA-TACE, and PA-HAIC. Additionally, PA-Sorafenib displayed better efficacy than PA-TACE. Nevertheless, there was no statistical significance between PA-Sorafenib and PA-HAIC, as well as PA-TACE and PA-HAIC. We also performed a subgroup analysis of studies focusing on HCC complicated by microvascular invasion after radical resection. In terms of OS, both PA-RT and PA-Sorafenib demonstrated a noteworthy improvement over PA-TACE, whereas no statistical significance was detected between PA-RT and PA-Sorafenib. Likewise, for DFS, both PA-Sorafenib and PA-RT exhibited superior efficacy compared to PA-TACE.

CONCLUSION

In patients with HCC after radical resection and a high risk of recurrence, both PA-Sorafenib and PA-RT significantly improved OS and DFS when compared to PA-TACE and PA-HAIC. Notably, PA-RT exhibited superior efficacy over PA-Sorafenib, PA-TACE, and PA-HAIC in terms of DFS. Similarly, PA-Sorafenib appeared to be more effective than PA-TACE for DFS.

Low-Dose Non-Targeted Effects and Mitochondrial Control

Non-targeted effects (NTE) have been generally regarded as a low-dose ionizing radiation (IR) phenomenon. Recently, regarding long distant abscopal effects have also been observed at high doses of IR) relevant to antitumor radiation therapy. IR is inducing NTE involving intracellular and extracellular signaling, which may lead to short-ranging bystander effects and distant long-ranging extracellular signaling abscopal effects. Internal and "spontaneous" cellular stress is mostly due to metabolic oxidative stress involving mitochondrial energy production (ATP) through oxidative phosphorylation and/or anaerobic pathways accompanied by the leakage of O₂^- and other radicals from mitochondria during normal or increased cellular energy requirements or to mitochondrial dysfunction. Among external stressors, ionizing radiation (IR) has been shown to very rapidly perturb mitochondrial functions, leading to increased energy supply demands and to ROS/NOS production. Depending on the dose, this affects all types of cell constituents, including DNA, RNA, amino acids, proteins, and membranes, perturbing normal inner cell organization and function, and forcing cells to reorganize the intracellular metabolism and the network of organelles. The reorganization implies intracellular cytoplasmic-nuclear shuttling of important proteins, activation of autophagy, and mitophagy, as well as induction of cell cycle arrest, DNA repair, apoptosis, and senescence. It also includes reprogramming of mitochondrial metabolism as well as genetic and epigenetic control of the expression of genes and proteins in order to ensure cell and tissue survival. At low doses of IR, directly irradiated cells may already exert non-targeted effects (NTE) involving the release of molecular mediators, such as radicals, cytokines, DNA fragments, small RNAs, and proteins (sometimes in the form of extracellular vehicles or exosomes), which can induce damage of unirradiated neighboring bystander or distant (abscopal) cells as well as immune responses. Such non-targeted effects (NTE) are contributing to low-dose phenomena, such as hormesis, adaptive responses, low-dose hypersensitivity, and genomic instability, and they are also promoting suppression and/or activation of immune cells. All of these are parts of the main defense systems of cells and tissues, including IR-induced innate and adaptive immune responses. The present review is focused on the prominent role of mitochondria in these processes, which are determinants of cell survival and anti-tumor RT.

Harnessing the abscopal effect for gastrointestinal malignancies in the era of immunotherapy

Gastrointestinal (GI) cancers are among the leading causes of cancer-related mortality and have traditionally been treated using a combination of surgical resection and chemoradiotherapy (CRT). While the introduction of immunotherapies over the last decade have dramatically changed the treatment landscape for some GI malignancies, including esophageal, gastric, and colorectal cancer, treatment resistance remains a major unaddressed obstacle for many patients. There has thus been emerging interest in determining the optimal treatment strategy for the delivery of immunotherapy in combination with traditional therapies. In this regard, a growing number of preclinical and clinical studies have suggested that combining radiation therapy (RT) with immunotherapy may work synergistically to improve treatment response through amplification of the abscopal effect. In this review, we discuss the rationale for RT in combination with immunotherapy. We further discuss how this knowledge may lead to a paradigm shift in the application of RT and highlight remaining issues pertaining to the delivery of combination therapy.

Cellular nanovesicles for therapeutic immunomodulation: A perspective on engineering strategies and new advances

Cellular nanovesicles which are referred to as cell-derived, nanosized lipid bilayer structures, have emerged as a promising platform for regulating immune responses. Owing to their outstanding advantages such as high biocompatibility, prominent structural stability, and high loading capacity, cellular nanovesicles are suitable for delivering various immunomodulatory molecules, such as small molecules, nucleic acids, peptides, and proteins. Immunomodulation induced by cellular nanovesicles has been exploited to modulate immune cell behaviors, which is considered as a novel cell-free immunotherapeutic strategy for the prevention and treatment of diverse diseases. Here we review emerging concepts and new advances in leveraging cellular nanovesicles to activate or suppress immune responses, with the aim to explicate their applications for immunomodulation. We overview the general considerations and principles for the design of engineered cellular nanovesicles with tailored immunomodulatory activities. We also discuss new advances in engineering cellular nanovesicles as immunotherapies for treating major diseases.

Abscopal Effect, Extracellular Vesicles and Their Immunotherapeutic Potential in Cancer Treatment

The communication between tumor cells and the microenvironment plays a fundamental role in the development, growth and further immune escape of the tumor. This communication is partially regulated by extracellular vesicles which can direct the behavior of surrounding cells. In recent years, it has been proposed that this feature could be applied as a potential treatment against cancer, since several studies have shown that tumors treated with radiotherapy can elicit a strong enough immune response to eliminate distant metastasis; this phenomenon is called the abscopal effect. The mechanism behind this effect may include the release of extracellular vesicles loaded with damage-associated molecular patterns and tumor-derived antigens which activates an antigen-specific immune response. This review will focus on the recent discoveries in cancer cell communications via extracellular vesicles and their implication in tumor development, as well as their potential use as an immunotherapeutic treatment against cancer.

Radiotherapy-induced tumor physical microenvironment remodeling to overcome immunotherapy resistance

The clinical benefits of immunotherapy are proven in many cancers, but a significant number of patients do not respond well to immunotherapy. The tumor physical microenvironment (TpME) has recently been shown to affect the growth, metastasis and treatment of solid tumors. The tumor microenvironment (TME) has unique physical hallmarks: 1) unique tissue microarchitecture, 2) increased stiffness, 3) elevated solid stress, and 4) elevated interstitial fluid pressure (IFP), which contribute to tumor progression and immunotherapy resistance in a variety of ways. Radiotherapy, a traditional and powerful treatment, can remodel the matrix and blood flow associated with the tumor to improve the response rate of immune checkpoint inhibitors (ICIs) to a certain extent. Herein, we first review the recent research advances on the physical properties of the TME and then explain how TpME is involved in immunotherapy resistance. Finally, we discuss how radiotherapy can remodel TpME to overcome immunotherapy resistance.

Advances of multi-omics applications in hepatic precancerous lesions and hepatocellular carcinoma: The role of extracellular vesicles

Due to the lack of distinct early symptoms and specific biomarkers, most patients with hepatocellular carcinoma (HCC) are usually diagnosed at advanced stages, rendering the treatment ineffective and useless. Therefore, recognition of the malady at precancerous lesions and early stages is particularly important for improving patient outcomes. The interest in extracellular vesicles (EVs) has been growing in recent years with the accumulating knowledge of their multiple cargoes and related multipotent roles in the modulation of immune response and tumor progression. By virtue of the rapid advancement of high-throughput techniques, multiple omics, including genomics/transcriptomics, proteomics, and metabolomics/lipidomics, have been widely integrated to analyze the role of EVs. Comprehensive analysis of multi-omics data will provide useful insights for discovery of new biomarkers and identification of therapeutic targets. Here, we review the attainment of multi-omics analysis to the finding of the potential role of EVs in early diagnosis and the immunotherapy in HCC.

Engineered Microparticles for Treatment of Murine Brain Metastasis by Reprograming Tumor Microenvironment and Inhibiting MAPK Pathway

Brain metastases (BRM) are common in advanced lung cancer. However, their treatment is challenging due to the blood-brain barrier (BBB) and the immunosuppressive tumor microenvironment (ITME). Microparticles (MPs), a type of extracellular vesicle, can serve as biocompatible drug delivery vehicles that can be further modulated with genetic engineering techniques. MPs prepared from cells induced with different insults are compared and it is found that radiation-treated cell-released microparticles (RMPs) achieve optimal targeting and macrophage activation. The enzyme ubiquitin-specific protease 7 (USP7), which simultaneously regulates tumor growth and reprograms M2 macrophages (M2Φ), is found to be expressed in BRM. Engineered RMPs are then constructed that comprise: 1) the RMP carrier that targets and reprograms M2Φ; 2) a genetically expressed SR-B1-targeting peptide for improved BBB permeability; and 3) a USP7 inhibitor to kill tumor cells and reprogram M2Φ. These RMPs successfully cross the BBB and target M2Φ in vitro and in vivo in mice, effectively reprogramming M2Φ and improving survival in a murine BRM model. Therapeutic effects are further augmented when combined with immune checkpoint blockade. This study provides proof-of-concept for the use of genetically engineered MPs for the treatment of BRM.

Carbon ion irradiation induces DNA damage in melanoma and optimizes the tumor microenvironment based on the cGAS-STING pathway

PURPOSES

Increased number of studies reveal the crucial role of the Cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway in anti-tumor immunity. In this study, we aim to explore the effect of cGAS/STING on tumor immune microenvironment of melanoma after carbon ion radiotherapy (CIRT) and the underlying mechanism.

METHODS

C57BL/6 mouse tumor models were used to evaluate the efficacy of different treatments (X-ray, carbon ion, PD-L1 inhibitor and combination therapies) on tumor growth and process. Mass cytometry was performed to assess tumor-infiltrating lymphocytes (TILs). DNA damage response (DDR) and cGAS/STING pathway were investigated by immunofluorescence-co-localization assays, γ-H2AX, P53-binding protein 1 (53BP1), Breast Cancer 1 (BRCA1), and cGAS measurements.

RESULTS

Carbon ion irradiation caused more DNA damages and cGAS-STING pathway activation compared with X-ray irradiation, and the former slowed the melanoma growth in syngeneic model. Although X-ray irradiation is not sensitive for melanoma treatment, carbon ion irradiation showed a significant anti-tumor effect for melanoma treatment. TILs analysis revealed that CIRT boosted the infiltration of natural killer (NK), CD4⁺, and CD8⁺ T cells, meanwhile increased the number of immune checkpoint (programmed death-1, PD-1, lymphocyte activation gene 3, LAG-3 and T-cell immunoglobulin and mucin domain-containing protein 3, TIM-3). Moreover, CIRT increased PD-L1 exposure on cell surface compared with X-ray group. Furthermore, CIRT combined with PD-L1 inhibitor therapy increased the number of T cells and NK cells in melanoma, and slowed the growth of melanoma compared with other therapies.

CONCLUSIONS

Our findings showed that CIRT displayed biological effects by increasing DNA damages of tumor cells and improving immunity in melanoma, which indicated that CIRT might be a potential synergetic treatment for radiotherapy and radioimmunotherapy in melanoma patients. Our works put forward a new insight to provide an effective strategy for melanoma therapy. These findings may help in the design of strategies on melanoma in clinical studies.

Tumor-derived extracellular vesicles in the colorectal cancer immune environment and immunotherapy

Despite significant advances in the screening, diagnosis, and treatment of colorectal cancer (CRC) immune checkpoint inhibitors (ICIs) continue to have limited utility outside of microsatellite-high disease. Given the durable response to immunotherapy seen across malignancies, increasing CRC response rates to ICI therapy is an active area of clinical research. An increasing body of work has demonstrated that tumor-derived extracellular vesicles (TEVs) are key modulators in tumor signaling and the determinants of the tumor microenvironment. Pre-clinical models have shown that TEVs are directly involved in antigen presentation and are involved in radiation-induced DNA damage signaling. Both direct and indirect modifications of these TEVs can alter CRC immunogenicity and ICI treatment response, making them attractive targets for potential therapeutic development. In addition, modified TEVs can be developed using several different mechanisms, with varied cargo including micro-RNAs and small peptide molecules. Recent work has shown strong pre-clinical evidence of injected modified TEV-induced ICI activity, with knockdown of the micro-RNA miR-424 in TEVs improving CRC immunogenicity and increasing anti-PD-1 activity in mouse models. Clinical trials are ongoing in the evaluation of modified TEVs in cancer therapy, but they appear to be a promising therapeutic target in CRC.

Tumor-Derived Extracellular Vesicles Predict Clinical Outcomes in Oligometastatic Prostate Cancer and Suppress Antitumor Immunity

PURPOSE

SABR has demonstrated clinical benefit in oligometastatic prostate cancer. However, the risk of developing new distant metastatic lesions remains high, and only a minority of patients experience durable progression-free response. Therefore, there is a critical need to identify which patients will benefit from SABR alone versus combination SABR and systemic agents. Herein we provide, to our knowledge, the first proof-of-concept of circulating prostate cancer-specific extracellular vesicles (PCEVs) as a noninvasive predictor of outcomes in oligometastatic castration-resistant prostate cancer (omCRPC) treated with SABR.

METHODS AND MATERIALS

We analyzed the levels and kinetics of PCEVs in the peripheral blood of 79 patients with omCRPC at baseline and days 1, 7, and 14 after SABR using nanoscale flow cytometry and compared with baseline values from cohorts with localized and widely metastatic prostate cancer. The association of omCRPC PCEV levels with oncological outcomes was determined with Cox regression models.

RESULTS

Levels of PCEVs were highest in mCRPC followed by omCRPC and were lowest in localized prostate cancer. High PCEV levels at baseline predicted a shorter median time to distant recurrence (3.5 vs 6.6 months; P = .0087). After SABR, PCEV levels peaked on day 7, and median overall survival was significantly longer in patients with elevated PCEV levels (32.7 vs 27.6 months; P = .003). This suggests that pretreatment PCEV levels reflect tumor burden, whereas early changes in PCEV levels after treatment predict response to SABR. In contrast, radiomic features of ¹¹C-choline positron emission tomography and computed tomography before and after SABR were not predictive of clinical outcomes. Interestingly, PCEV levels and peripheral tumor-reactive CD8 T cells (T_TR; CD8⁺ CD11a^high) were correlated.

CONCLUSIONS

This original study demonstrates that circulating PCEVs can serve as prognostic and predictive markers to SABR to identify patients with "true" omCRPC. In addition, it provides novel insights into the global crosstalk, mediated by PCEVs, between tumors and immune cells that leads to systemic suppression of immunity against CRPC. This work lays the foundation for future studies to investigate the underpinnings of metastatic progression and provide new therapeutic targets (eg, PCEVs) to improve SABR efficacy and clinical outcomes in treatment-resistant CRPC.

Phospholipid-Membrane-Based Nanovesicles Acting as Vaccines for Tumor Immunotherapy: Classification, Mechanisms and Applications

Membrane vesicles, a group of nano- or microsized vesicles, can be internalized or interact with the recipient cells, depending on their parental cells, size, structure and content. Membrane vesicles fuse with the target cell membrane, or they bind to the receptors on the cell surface, to transfer special effects. Based on versatile features, they can modulate the functions of immune cells and therefore influence immune responses. In the field of tumor therapeutic applications, phospholipid-membrane-based nanovesicles attract increased interest. Academic institutions and industrial companies are putting in effort to design, modify and apply membrane vesicles as potential tumor vaccines contributing to tumor immunotherapy. This review focuses on the currently most-used types of membrane vesicles (including liposomes, bacterial membrane vesicles, tumor- and dendritic-cell-derived extracellular vesicles) acting as tumor vaccines, and describes the classification, mechanism and application of these nanovesicles.

Downregulation of exosomal MHC-I promotes glioma cells escaping from systemic immunosurveillance

Tumor-derived exosomes are capable of inducing immune dysfunction and favoring the formation and progression of tumor. The major histocompatibility complex class I (MHC-I) plays a key role in antitumor immune responses by presenting tumor antigens to cytotoxic T lymphocytes. However, the role of tumor-derived circulating exosomal MHC-I on immune system activation remains unclear. We demonstrated that low level of glioma cells-derived exosomal MHC-I was associated with the dysfunction of CD8⁺ T cells in immune activation and cytotoxicity. MHC-I upregulation in exosomes restored antigen presentation of glioma cells and activated CD8⁺ T cells to exert robust antitumor immune response in combination with immune checkpoint blockade. Collectively, these data provided evidences for an important interplay between exosomal MHC-I and CD8⁺ T cells to activate systemic antitumor immune response, and interpreted how glioma cells evaded immunosurveillance, induced immunosuppression and were resistant to immunotherapy from the perspective of systemic immunity.

Engineered tumor cell-derived vaccines against cancer: The art of combating poison with poison

Tumor vaccination is a promising approach for tumor immunotherapy because it presents high specificity and few side effects. However, tumor vaccines that contain only a single tumor antigen can allow immune system evasion by tumor variants. Tumor antigens are complex and heterogeneous, and identifying a single antigen that is uniformly expressed by tumor cells is challenging. Whole tumor cells can produce comprehensive antigens that trigger extensive tumor-specific immune responses. Therefore, tumor cells are an ideal source of antigens for tumor vaccines. A better understanding of tumor cell-derived vaccines and their characteristics, along with the development of new technologies for antigen delivery, can help improve vaccine design. In this review, we summarize the recent advances in tumor cell-derived vaccines in cancer immunotherapy and highlight the different types of engineered approaches, mechanisms, administration methods, and future perspectives. We discuss tumor cell-derived vaccines, including whole tumor cell components, extracellular vesicles, and cell membrane-encapsulated nanoparticles. Tumor cell-derived vaccines contain multiple tumor antigens and can induce extensive and potent tumor immune responses. However, they should be engineered to overcome limitations such as insufficient immunogenicity and weak targeting. The genetic and chemical engineering of tumor cell-derived vaccines can greatly enhance their targeting, intelligence, and functionality, thereby realizing stronger tumor immunotherapy effects. Further advances in materials science, biomedicine, and oncology can facilitate the clinical translation of tumor cell-derived vaccines.

Systematic review of adjuvant external beam radiotherapy for hepatocellular carcinoma following radical hepatectomy

BACKGROUND AND AIM

Recurrence remains the main bottleneck hindering outcomes of hepatectomy for hepatocellular carcinoma (HCC). Owing to technological advances, external beam radiotherapy (EBRT) is being increasingly used in the management of HCC; however, there is no consensus on the role of adjuvant EBRT following hepatectomy.

METHODS

A systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. PubMed, MedLine, Embase, the Cochrane Library, Web of Knowledge were used to screen eligible studies (published as of May 1st, 2022) that evaluated the clinical safety and efficacy of EBRT for HCC receiving hepatectomy. The endpoints were disease-free survival (DFS), overall survival (OS), and adverse events (AEs).

RESULTS

A total of ten studies were eligible (three randomized controlled trials, one phase II trial, and six retrospective comparative studies). The pooled hazard ratio (HR) for median DFS and OS were both in favor of adjuvant EBRT compared with surgery alone (all P<0.05), and the advantage of adjuvant EBRT was also confirmed in subgroups stratified by different populations (narrow margin, P<0.05; microvascular invasion, P<0.05; portal vein tumor thrombus, P<0.05) and study designs (prospective studies, P<0.05; retrospective studies, P<0.05). Adjuvant EBRT was also found to be superior to adjuvant TACE (P<0.05). Pooled rates of overall AEs and severe AEs were 65.3% and 12.2%, but no fatal AEs were reported.

CONCLUSION

Adjuvant EBRT can be considered for HCC patients, especially those with a high risk of recurrence. Further studies are required for validation of these findings.

Multifaceted roles of extracellular RNAs in different diseases

Extracellular RNAs (exRNAs) are novel circulating factors that can be used as biomarkers in various diseases. Their unique and diverse kinds, as well as their role as biomarkers, make them significant biomarkers. There has been immense work carried out since the discovery of exRNAs in circulation and other biological fluids to catalog and determine whether exRNAs may be utilized as indicators for health and illness. In this review, we aim to understand the current state of exRNAs in relation to various diseases and their potential as biomarkers. We will also review current issues and challenges faced in using exRNAs, with clinical and lab trials, that can be used as viable markers for different diseases.

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.