Radiotherapy-exposed CD8+ and CD4+ neoantigens enhance tumor control

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.

Impact of radiation therapy on the immunological tumor microenvironment

External beam radiation therapy (RT) is a cornerstone of modern cancer management, being utilized in both curative and palliative settings due to its safety, efficacy, and widespread availability. A primary biological effect of RT is DNA damage, which leads to significant cytostatic and cytotoxic effects. Importantly, malignant cells possess a limited capacity for DNA repair compared to normal cells, and when combined with irradiation techniques that minimize damage to healthy tissues, this creates an advantageous therapeutic window. However, the clinical effectiveness of RT also appears to involve both direct and indirect interactions between RT and non-transformed components of the tumoral ecosystem, particularly immune cells. In this review, we describe the molecular and cellular mechanisms by which irradiated cancer cells modify the immunological tumor microenvironment and how such changes ultimately impact tumor growth.

Targeting B7-H3 enhances the efficacy of neoantigen-based cancer vaccine in combination with radiotherapy

The clinical response to immune checkpoint blockade (ICB) is limited in the majority of patients with colorectal cancer. These immune checkpoint proteins may not only inhibit T-cell-mediated antitumor immunity but also attenuate antigen presentation, including mutation-associated neoantigens. Here, we found that tumor B7-H3 levels may limit the therapeutic response to chemoradiotherapy in patients with locally-advanced rectal cancer. Knockdown of tumor B7-H3 significantly increased antigen presentation to increase T cell infiltration and killing ability, including neoantigen-specific T-cell response. Blockade of B7-H3 significantly augmented neoantigen-specific T cells response and remarkably enhanced the therapeutic efficacy of neoantigen-based cancer vaccines combined with radiotherapy, decreasing the risk of distant tumors in vivo. Taken together, these results demonstrated that targeting B7-H3 significantly enhanced the therapeutic efficacy of neoantigen cancer vaccines as well as radiotherapy by increasing the extent of neoantigen-specific T cells, even for PD-1/PD-L1 blockade-resistant colorectal cancers.

Efficacy of immunotherapy remained in patients with recurrent/metastatic non-small-cell lung cancer after surgery with or without postoperative thoracic radiotherapy: a bi-center retrospective study

PURPOSE

Since mediastinal lymph node dissection and radiotherapy (RT) have potential unclear impacts on pulmonary lymphatic system, this study aimed to assess the effectiveness of immune checkpoint inhibitors (ICIs) in recurrent/metastatic non-small-cell lung cancer (NSCLC) patients who previously received radical surgery with or without thoracic RT.

METHODS

Clinical data of patients who underwent pulmonary lobectomy with systematic lymphadenectomy (2000.1.1-2021.7.2) and received immunotherapy after progression were retrospectively analyzed. Efficacy was mainly evaluated based on progression-free survival (PFS) from the start of the ICIs. Toxicity was defined as treatment discontinuation due to immune-related adverse effects (irAEs).

RESULTS

Ninety-five patients were enrolled in the final cohort and 30 (31.6%) patients received thoracic RT before ICI treatment. ICIs were administered as a first-line systematic treatment in 52.6% of patients. The median follow-up time was 14.7 months (95% confidence interval [CI] 13.3-18.7 months). The median PFS was 12.3 months (95% CI 8.5-36.6 months). Six (6.3%) patients had treatment suspended due to irAEs. Patients who received RT had comparable median PFS with the non-RT group (17.0 months vs. 11.1 months, p = 0.16). Similar toxicity rates were observed. Similar mPFS were reported in the stage III subgroup (RT vs. non-RT, 8.10 vs. 8.45 months, p = 0.86) or the subgroup treated by ICIs as primary systematic therapy (RT vs. non-RT, 13.6 vs. 16.1 months, p = 0.45).

CONCLUSIONS

ICIs remained effective in recurrent/metastatic NSCLC patients with radical surgery and RT did not significantly compromise therapeutic effects.

Leveraging radiotherapy to improve immunotherapy outcomes: rationale, progress and research priorities

The most successful immunotherapies for solid malignancies to date, immune checkpoint inhibitors, target the essential role of T cells in antitumor immunity. However, T-cell dysfunction presents a major hindrance to treatment efficacy, warranting research into combined treatment strategies for improving outcomes. The use of radiotherapy for this purpose has garnered much interest. Preclinical study has established that radiotherapy activates various immune mechanisms to improve T-cell activation, localisation and function within tumors, which improves response to immune checkpoint inhibitors. However, so far, these strategies have not been successfully translated into the clinic. Here, we briefly reflect on the development of immune checkpoint inhibitors and the mechanistic insights revealed by an evolving understanding of T-cell dysfunction in cancer, before providing an overview of the immunomodulatory effects of radiotherapy in the context of the T-cell-mediated antitumor immune response. We discuss the mixed results of clinical trials, comment on various factors that may preclude immuno-radiotherapy responses in the clinic, and highlight priorities for preclinical and clinical study. Finally, we discuss the role of emerging combinations of radiotherapy and immunotherapy to potentially provide additional treatment options and improve outcomes for patients.

Topical TLR7 agonist and radiotherapy in patients with metastatic breast cancer

BACKGROUND

Toll-like receptor (TLR) agonists and radiation therapy hold promise for cancer immunotherapy. We conducted a phase I/II trial combining topical imiquimod (IMQ, a TLR-7 agonist) and local radiotherapy (RT) in patients with metastatic breast cancer accompanied by longitudinal transcriptional analysis of tumor biopsies.

METHODS

The primary objective of the trial (NCT01421017) was to assess systemic responses by immune-related response criteria (irRC) after an 8-week cycle of topical IMQ and concurrent local RT (cohort 1). An amendment to the trial added two cohorts, both received one dose of cyclophosphamide (CTX) administered 1 week before study treatment initiation, IMQ/RT/CTX (cohort 2) and RT/CTX control (cohort 3). Cutaneous metastases were prospectively assigned to treatment with IMQ and RT (area A) or IMQ alone (area B). Secondary objectives were safety (Common Terminology Criteria for Adverse Events criteria) and local response in skin metastases. In all IMQ cohorts, tumors were biopsied before treatment and at 2 and 3 weeks.

RESULTS

31 patients were enrolled (n=12, n=12, and n=7, in cohort 1, 2, and 3, respectively), with 4 out of 24 patients in the IMQ cohorts showing systemic tumor responses (two complete responses (CR) and two partial responses (PR)). No objective responses were observed in the seven patients enrolled in the control arm (RT alone). The treatment was well-tolerated, no grade 4-5 treatment-related adverse events occurred and grade 3 AEs were manageable (anemia, local pain, and local ulceration, n=1 each). Local objective responses were observed in 19/24 (9 CR and 10 PR) and 5/24 (5 PR) in areas treated with combined IMQ-RT and IMQ alone, respectively (p<0.001). All 24 patients treated with IMQ underwent serial biopsies, and 84 samples yielded sufficient material for transcriptional analyses. These revealed that the presence of a T-helper 1 functional orientation of the tumor microenvironment paralleled by the downregulation of DNA-repair genes was associated with CR after IMQ+RT, but not after IMQ alone. No post-treatment activation of immune-effector functions was observed in stable and progressing lesions.

CONCLUSIONS

Our findings support the safety and clinical efficacy of combining topical IMQ with local RT for recurrent breast cancer, with evidence of local and occasional systemic antitumor activity.

TRIAL REGISTRATION NUMBER

NCT01421017.

Synergistic enhancement of radio-immunotherapy efficacy by IL-15 via macrophage activation and memory T cell response

Successful immunotherapy requires systemic activation of the immune system. Radio-immunotherapy has a synergistic effect, enhancing this activation, but still faces many challenges, requiring methods to further improve its efficacy. Interleukin 15 (IL-15) is considered a potential therapeutic agent because of its broad immunoregulatory activity. This study found that in various tumor-bearing mouse models, systemic immune activation mediated by memory T cells in secondary lymphoid organs was crucial after radio-immunotherapy and IL-15 played a key role in this process. Radio-immunotherapy stimulated the expression of IL-15Rα on macrophages in the tumor microenvironment. When macrophages were depleted, the IL-15 levels in the tumor microenvironment and spleen tissues significantly decreased. Co-culture models confirmed that radio-immunotherapy enhanced the anti-tumor immune response by activating macrophages to secrete IL-15. Applying IL-15 significantly enhances the effects of radio-immunotherapy, stimulating systemic immune activation and providing long-term memory effects and tumor protection. Under co-culture conditions, IL-15 combined with radio-immunotherapy stimulated the proliferation of CD8+ T cells, secretion of IFN-γ and TNF-α, and secretion of chemokines by macrophages, especially CCL5, increasing the recruitment of effector T cells and enhancing the immune response. The synergistic effect of IL-15 and radio-immunotherapy was macrophage-dependent. Our study revealed the mechanism of IL-15 in systemic immune activation after radio-immunotherapy and explored the potential use of IL-15 to enhance the efficacy of radio-immunotherapy, providing new avenues for future treatment strategies.

Single-cell RNA sequencing revealed changes in the tumor microenvironment induced by radiotherapy for cervical cancer and the molecular mechanism of mast cells in immunosuppression

Radiotherapy (RT) is an important treatment for cervical cancer (CC), effectively controlling tumor growth and improving survival rates. However, radiotherapy-induced cell heterogeneity and its underlying mechanisms remain unclear, which may potentially impact treatment efficacy. This study aims to investigate tumor microenvironment changes following radiotherapy for CC, hoping to provide evidence to improve the therapeutic effects of radiotherapy. For the first time, we applied single-cell RNA sequencing (scRNA-seq) to analyze tissue samples from three CC patients pre- and post-radiotherapy. We obtained gene expression data from 52,506 cells to identify the cellular changes and molecular mechanisms induced by radiotherapy. Radiotherapy significantly alters cellular composition and gene expression within the tumor microenvironment (TME), notably upregulating mast cell expression. Mast cells are involved in multiple cell axes in the CC ecosystem after radiotherapy, and play a pivotal role in tumor immunosuppression and matrix remodeling. scRNA-seq revealed gene expression variations among cell types after radiotherapy, underscoring the importance of specific cell types in modulating the TME post-treatment. This study revealed the molecular mechanism of radiotherapy for CC and the role of mast cells, providing a foundation for optimizing the personalized treatment of CC.

The immunopeptidome of colon cancer cells treated with topoisomerase inhibiting drug reveals differential as well as common endogenous protein sampling and display of MHC I-associated peptides

Immunotherapy options for microsatellite stable (MSS) colorectal cancer are currently very limited. The lack of detectably unique or altered immunogens in the tumor microenvironment may be a factor. Radiation and chemotherapy may enhance immunotherapy by increasing cancer cell visibility through Major Histocompatibility Complex I (MHC I) expression. To investigate this, we treated MSS and microsatellite-instable (MSI) colon cancer cells with a topoisomerase inhibitor and analyzed MHC I-associated peptides. Treatment increased peptide numbers by 5% in RKO (MSI) cells and 83% in SW620 (MSS) cells, with 40-50% of peptides being exclusive to treatment. Additionally, clustering analysis revealed a set of peptides with uniquely conserved residues displayed only in treated MSS SW620 cells. Gene Ontology analysis of MHC I-displayed proteins revealed a treatment-induced increase in extracellular vesicle- and nuclear-derived proteins, alongside reduced cytosolic protein sampling. Overall, we present evidence for treatment-inducible differential display of peptides, some of which may affect interactions and functions of immune cells. Given the multitude of factors that modulate the effects of increased MHC I expression and associated peptides, further studies are needed to elucidate the pathophysiological implications of these changes.

The Role of the Major Histocompatibility Complex Region on Chromosome 6 in Skin Atrophy: A Mendelian Randomization Study

BACKGROUND

Skin atrophy (SA) is a pathological condition marked by the thinning of the skin, decreased elasticity, and reduced functionality, often arising from aging, chronic glucocorticoid use, or autoimmune diseases.

OBJECTIVE

This study investigates the role of the major histocompatibility complex (MHC) region on chromosome 6 in the development of SA.

METHODS

We applied summary-data-based Mendelian randomization (SMR) using eQTL data of three skin-related tissues (whole blood, lower leg, and suprapubic) from the GTEx database, and SA genome-wide association study data from FinnGen. Further, we conducted functional enrichment, colocalization, and drug enrichment analyses on the core genes (intersection genes) to explore their functions and druggability.

RESULTS

Six core genes (PSORS1C3, HLA-C, HLA-DRB5, HLA-DRB6, HLA-DQA1, and HLA-DQB1) located on chromosome 6p21 were consistently identified across all tissues. Functional enrichment, pathway, and protein-protein interaction analyses revealed that these genes are involved in antigen processing and immune response regulation. Drug enrichment analysis highlighted potential therapeutic targets, including interactions with palladium, azathioprine, and insulin. However, limitations in available data for PSORS1C3 and HLA-DRB6, as well as inconclusive colocalization results, suggest a need for further research.

CONCLUSION

This study highlights the involvement of six core genes within the MHC region on chromosome 6 in the development of SA, emphasizing their roles in immune regulation and antigen presentation. These findings open new avenues for understanding SA and offer a foundation for future investigations into immune-related pathways in skin diseases.

Clonal driver neoantigen loss under EGFR TKI and immune selection pressures

Neoantigen vaccines are under investigation for various cancers, including epidermal growth factor receptor (EGFR)-driven lung cancers1,2. We tracked the phylogenetic history of an EGFR mutant lung cancer treated with erlotinib, osimertinib, radiotherapy and a personalized neopeptide vaccine (NPV) targeting ten somatic mutations, including EGFR exon 19 deletion (ex19del). The ex19del mutation was clonal, but is likely to have appeared after a whole-genome doubling (WGD) event. Following osimertinib and NPV treatment, loss of the ex19del mutation was identified in a progressing small-cell-transformed liver metastasis. Circulating tumour DNA analyses tracking 467 somatic variants revealed the presence of this EGFR wild-type clone before vaccination and its expansion during osimertinib/NPV therapy. Despite systemic T cell reactivity to the vaccine-targeted ex19del neoantigen, the NPV failed to halt disease progression. The liver metastasis lost vaccine-targeted neoantigens through chromosomal instability and exhibited a hostile microenvironment, characterized by limited immune infiltration, low CXCL9 and elevated M2 macrophage levels. Neoantigens arising post-WGD were more likely to be absent in the progressing liver metastasis than those occurring pre-WGD, suggesting that prioritizing pre-WGD neoantigens may improve vaccine design. Data from the TRACERx 421 cohort3 provide evidence that pre-WGD mutations better represent clonal variants, and owing to their presence at multiple copy numbers, are less likely to be lost in metastatic transition. These data highlight the power of phylogenetic disease tracking and functional T cell profiling to understand mechanisms of immune escape during combination therapies.

Autophagosomes coated in situ with nanodots act as personalized cancer vaccines

Autophagosome cancer vaccines can promote cross-presentation of multiple tumour antigens and induce cross-reactive T cell responses. However, so far, there is no effective method for obtaining a highly immunogenic autophagosomal cancer vaccine because autophagosomes, once formed, quickly fuse with lysosomes and cannot easily escape from cells. Here we report a functional Ti2NX nanodot that caps the autophagosome membrane lipid phosphatidylinositol-4-phosphate, blocking the fusion of autophagosomes with lysosomes and producing stable nanodot-coated autophagosomes in tumours. The formed nanodot-coated autophagosomes can escape from cancer cells to lymph nodes, where they activate tumour-specific T cells. We show that our approach reduces tumour burden and provide long-term immune surveillance protection for cured mice. This work provides a method for the direct formation of personalized autophagosome-based cancer vaccines in vivo, offering a promising strategy for tumour treatment.

Targeting the mevalonate pathway potentiates NUAK1 inhibition-induced immunogenic cell death and antitumor immunity

The induction of immunogenic cell death (ICD) impedes tumor progression via both tumor cell-intrinsic and -extrinsic mechanisms, representing a robust therapeutic strategy. However, ICD-targeted therapy remains to be explored and optimized. Through kinome-wide CRISPR-Cas9 screen, NUAK family SNF1-like kinase 1 (NUAK1) is identified as a potential target. The ICD-provoking effect of NUAK1 inhibition depends on the production of reactive oxygen species (ROS), consequent to the downregulation of nuclear factor erythroid 2-related factor 2 (NRF2)-mediated antioxidant gene expression. Moreover, the mevalonate pathway/cholesterol biosynthesis, activated by spliced form of X-box binding protein 1 (XBP1s) downstream of ICD-induced endoplasmic reticulum (ER) stress, functions as a negative feedback mechanism. Targeting the mevalonate pathway with CRISPR knockout or the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) inhibitor simvastatin amplifies NUAK1 inhibition-mediated ICD and antitumor activity, while cholesterol dampens ROS and ICD, and therefore also dampens tumor suppression. The combination of NUAK1 inhibitor and statin enhances the efficacy of anti-PD-1 therapy. Collectively, our study unveils the promise of blocking the mevalonate-cholesterol pathway in conjunction with ICD-targeted immunotherapy.

Challenges and Opportunities for the Clinical Application of the Combination of Immune-Checkpoint Inhibitors and Radiation Therapy in the Treatment of Advanced Pancreatic Cancer

The treatment landscape of pancreatic ductal adenocarcinoma (PDAC) has seen slow progress, with immune-checkpoint inhibitors (ICIs) failing to replicate the success observed in other malignancies. The immune-suppressive tumor microenvironment (TME) in PDAC represents a significant barrier, limiting the activation of an effective antitumor immune response following ICI administration. Radiation therapy (RT), with its immunomodulatory effects, has emerged as a promising partner for ICIs. This review discusses the recent efforts evaluating the combination of ICIs and RT in advanced PDAC. While the combination therapy has demonstrated an acceptable safety profile, the reported clinical efficacy remains modest, particularly for patients with refractory metastatic PDAC. The ongoing phase III trial (JCOG1908E) will clarify whether the combination of ICI and RT improves overall survival in chemo-naïve patients with locally advanced PDAC.

Orchestrating cancer therapy: Recent advances in nanoplatforms harmonize immunotherapy with multifaceted treatments

Advancements in cancer therapy have increasingly focused on leveraging the synergistic effects of combining immunotherapy with other treatment modalities, facilitated by the use of innovative nanoplatforms. These strategies aim to augment the efficacy of standalone treatments while addressing their inherent limitations. Nanoplatforms enable precise delivery and controlled release of therapeutic agents, which enhances treatment specificity and reduces systemic toxicity. This review highlights the critical role of nanomaterials in enhancing immunotherapy when combined with chemotherapy, radiotherapy, photodynamic therapy, photothermal therapy, and sonodynamic therapy. Additionally, it addresses current challenges, including limited in vivo studies, difficulties in standardizing and scaling production, complexities of combination therapies, lack of comparative analyses, and the need for personalized treatments. Future directions involve refining nanoplatform engineering for improved targeting and minimizing adverse effects, alongside large animal studies to establish the long-term efficacy and safety of these combined therapeutic strategies. These efforts aim to translate laboratory successes into clinically viable treatments, significantly improving therapeutic outcomes and advancing the field of oncology.

Chimeric antigen receptor macrophages (CAR-M) sensitize HER2+ solid tumors to PD1 blockade in pre-clinical models

We previously developed human CAR macrophages (CAR-M) and demonstrated redirection of macrophage anti-tumor function leading to tumor control in immunodeficient xenograft models. Here, we develop clinically relevant fully immunocompetent syngeneic models to evaluate the potential for CAR-M to remodel the tumor microenvironment (TME), induce T cell anti-tumor immunity, and sensitize solid tumors to PD1/PDL1 checkpoint inhibition. In vivo, anti-HER2 CAR-M significantly reduce tumor burden, prolong survival, remodel the TME, increase intratumoral T cell and natural killer (NK) cell infiltration, and induce antigen spreading. CAR-M therapy protects against antigen-negative relapses in a T cell dependent fashion, confirming long-term anti-tumor immunity. In HER2+ solid tumors with limited sensitivity to anti-PD1 (aPD1) monotherapy, the combination of CAR-M and aPD1 significantly improves tumor growth control, survival, and remodeling of the TME in pre-clinical models. These results demonstrate synergy between CAR-M and T cell checkpoint blockade and provide a strategy to potentially enhance response to aPD1 therapy for patients with non-responsive tumors.

Cancer vaccines: platforms and current progress

Cancer vaccines, crucial in the immunotherapeutic landscape, are bifurcated into preventive and therapeutic types, both integral to combating oncogenesis. Preventive cancer vaccines, like those against HPV and HBV, reduce the incidence of virus-associated cancers, while therapeutic cancer vaccines aim to activate dendritic cells and cytotoxic T lymphocytes for durable anti-tumor immunity. Recent advancements in vaccine platforms, such as synthetic peptides, mRNA, DNA, cellular, and nano-vaccines, have enhanced antigen presentation and immune activation. Despite the US Food and Drug Administration approval for several vaccines, the full therapeutic potential remains unrealized due to challenges such as antigen selection, tumor-mediated immunosuppression, and optimization of delivery systems. This review provides a comprehensive analysis of the aims and implications of preventive and therapeutic cancer vaccine, the innovative discovery of neoantigens enhancing vaccine specificity, and the latest strides in vaccine delivery platforms. It also critically evaluates the role of adjuvants in enhancing immunogenicity and mitigating the immunosuppressive tumor microenvironment. The review further examines the synergistic potential of combining cancer vaccines with other therapies, such as chemotherapy, radiotherapy, and immune checkpoint inhibitors, to improve therapeutic outcomes. Overcoming barriers such as effective antigen identification, immunosuppressive microenvironments, and adverse effects is critical for advancing vaccine development. By addressing these challenges, cancer vaccines can offer significant improvements in patient outcomes and broaden the scope of personalized cancer immunotherapy.

Landscape of the Peripheral Immune Response Induced by Intraoperative Radiotherapy Combined with Surgery in Early Breast Cancer Patients

A comprehensive analysis of the immune response triggered by intraoperative radiation therapy (IORT) remains incomplete. In this study, single-cell RNA sequencing and single-cell T cell receptor sequencing are conducted on peripheral blood mononuclear cells (PBMCs) from patient with early-stage breast cancer before and after IORT. Following IORT combined with surgery (defined as IORT+Surgery), PBMC counts remained stable, with increased proportions of T cells, mononuclear phagocytes, and plasma cells, and a reduction in neutrophil proportions. The cytotoxic score of CD8Teff_GZMK cells increased significantly post-IORT. Communication between CD8Teff_GZMK cells and other immune cells via MIF_CD74 and MIF_TNFRSF14 is decreased after IORT. cDCs showed an upregulation of the MCH II signaling pathway, while memory B cells exhibited enhanced activation of the B cell pathway. T cell clones expanded significantly after treatment. IORT+Surgery demonstrated the ability to partially suppress the anti-tumor effects of neutrophils. Flow cytometry analysis and co-culture experiments are utilized to delve deeper into the functional alterations in T cells. IORT+Surgery significantly enhanced T cell cytotoxic activity. Blockade of PD-1 of post-IORT PBMCs shows higher T-cell activity than that of pre-IORT PBMCs. This research highlights IORT's impact on immune cells, offering insights for targeting immune responses in breast cancer.

Understanding the Immune System and Biospecimen-Based Response in Glioblastoma: A Practical Guide to Utilizing Signal Redundancy for Biomarker and Immune Signature Discovery

Glioblastoma (GBM) is a primary central nervous system malignancy with a median survival of 15-20 months. The presence of both intra- and intertumoral heterogeneity limits understanding of biological mechanisms leading to tumor resistance, including immune escape. An attractive field of research to examine treatment resistance are immune signatures composed of cluster of differentiation (CD) markers and cytokines. CD markers are surface markers expressed on various cells throughout the body, often associated with immune cells. Cytokines are the effector molecules of the immune system. Together, CD markers and cytokines can serve as useful biomarkers to reflect immune status in patients with GBM. However, there are gaps in the understanding of the intricate interactions between GBM and the peripheral immune system and how these interactions change with standard and immune-modulating treatments. The key to understanding the true nature of these interactions is through multi-omic analysis of tumor progression and treatment response. This review aims to identify potential non-invasive blood-based biomarkers that can contribute to an immune signature through multi-omic approaches, leading to a better understanding of immune involvement in GBM.

A recent perspective on designing tumor vaccines for tumor immunology

With the rapid development of immunotherapy, therapeutic tumor vaccines, which aim to enhance the immunogenicity of tumor cells and activate the patient's immune system to kill tumor cells, as well as eliminate or inhibit tumor growth, have drawn increasing attention in the field of tumor therapy. However, due to the lack of immune cell infiltration, low immunogenicity, immune escape and other problems, the efficacy of tumor vaccine is often limited. Researchers have developed a variety of strategies to enhance tumor immune recognition, such as improving the immunogenicity of tumor antigens, selecting a suitable vaccine platform, or combining tumor vaccines with other anticancer treatments. In this review, we will deliberate on how to overcome the problem of therapeutic tumor vaccines, and discuss the up-to-date progress and achievements in the tumor vaccine development, as well as their future in cancer treatment.

Immune checkpoint inhibitors as first-line treatment for brain metastases in stage IV NSCLC patients without driver mutations

Immune checkpoint inhibitors (ICI) therapy with or without chemotherapy has been established as the first-line treatment for patients with non-oncogene addicted advanced Non-Small Cell Lung Cancer (NSCLC). Yet some clinical settings, such as the treatment sequence in patients with brain metastases, have barely been evidenced. Although ICIs cannot directly cross the blood-brain barrier (BBB), evidence suggests that BBB damage could allow ICIs into the central nervous system, or that they can have an indirect effect on the tumor immune microenvironment (TIME) and cause an anti-tumor response. Pivotal phase III trials have included a highly selected population but offer few data on these patients. Here we first review how ICIs can indirectly shape the brain metastases microenvironment through different mechanisms, and some possible causes of ICIs resistance. We also analyze the evidence reported in pivotal phase III trials and phase II trials focused on NSCLC brain metastases for first-line treatment, and the evidence for upfront or delayed local brain therapy. Finally, we discuss the best evidence-based approach to treat NSCLC patients with brain metastases and propose future research.

Exogenous or in situ vaccination to trigger clinical responses in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) is a lethal disease for which remarkable therapeutic resistance is the norm. Conventional immunotherapies, like immune checkpoint inhibitors, show limited efficacy in PDA due to a remarkably immunosuppressive tumor microenvironment (TME) and systemic inflammation. This review discusses the potential of both exogenous and in situ vaccination strategies to overcome these barriers and enhance anti-tumor immunity in PDA. Exogenous vaccines, including whole-cell, dendritic cell, peptide, and nucleic acid-based vaccines, have shown varying degrees of promise but face challenges related to antigen selection, production complexities, and patient-specific factors. In contrast, in situ vaccination strategies leverage conventional cytotoxic therapies, such as chemotherapy and radiation therapy, to induce immunogenic cell death and modulate the TME with the aim to stimulate anti-tumor immunity. While preclinical studies support the use of in situ vaccination, balancing the stimulatory and inhibitory effects is likely fundamental to eliciting productive anti-tumor responses in patients. Ongoing research seeks to identify new innovative strategies that can harness the endogenous immune response and trigger in situ vaccination. Overall, while both vaccination approaches offer significant potential, further research and clinical trials will be needed to optimize these strategies for improving patient outcomes in PDA.

Neoadjuvant lutetium PSMA, the TIME and immune response in high-risk localized prostate cancer

High-risk localized prostate cancer remains a lethal disease with high rates of recurrence, metastases and death, despite attempts at curative local treatment including surgery. Disease recurrence is thought to be a result of failure of local control and occult micrometastases. Neoadjuvant strategies before surgery have been effective in many cancers, but, to date, none has worked in this setting for prostate cancer. Prostate-specific membrane antigen (PSMA)-based theranostics is an exciting and rapidly evolving field in prostate cancer. The novel intravenous radionuclide therapy, [177Lu]Lu-PSMA-617 (lutetium PSMA) has been shown to be effective in treating men with metastatic castration-resistant prostate cancer, targeting cells expressing PSMA throughout the body. When given in a neoadjuvant setting, lutetium PSMA might also improve long-term oncological outcomes in men with high-risk localized disease. A component of radiotherapy is potentially an immunogenic form of cancer cell death. Lutetium PSMA could cause cancer cell death, resulting in release of tumour antigens and induction of a tumour-specific systemic immune response. This targeted radioligand treatment has the potential to treat local and systemic tumour sites by directly targeting cells that express PSMA, but might also act indirectly via this systemic immune response. In selected patients, lutetium PSMA could potentially be combined with systemic immunotherapies to augment the antitumour T cell response, and this might produce long-lasting immunity in prostate cancer.

Longitudinal Assessment of Tumor-Infiltrating Lymphocytes in Primary Breast Cancer Following Neoadjuvant Radiation Therapy

PURPOSE

Tumor-infiltrating lymphocytes (TILs) have prognostic significance in several cancers, including breast cancer. Despite interest in combining radiation therapy with immunotherapy, little is known about the effect of radiation therapy itself on the tumor-immune microenvironment, including TILs. Here, we interrogated longitudinal dynamics of TILs and systemic lymphocytes in patient samples taken before, during, and after neoadjuvant radiation therapy (NART) from PRADA and Neo-RT breast clinical trials.

METHODS AND MATERIALS

We manually scored stromal TILs (sTILs) from longitudinal tumor samples using standardized guidelines as well as deep learning-based scores at cell-level (cTIL) and cell- and tissue-level combination analyses (SuperTIL). In parallel, we interrogated absolute lymphocyte counts from routine blood tests at corresponding time points during treatment. Exploratory analyses studied the relationship between TILs and pathologic complete response (pCR) and long-term outcomes.

RESULTS

Patients receiving NART experienced a significant and uniform decrease in sTILs that did not recover at the time of surgery (P < .0001). This lymphodepletive effect was also mirrored in peripheral blood. Our SuperTIL deep learning score showed good concordance with manual sTILs and importantly performed comparably to manual scores in predicting pCR from diagnostic biopsies. The analysis suggested an association between baseline sTILs and pCR, as well as sTILs at surgery and relapse, in patients receiving NART.

CONCLUSIONS

This study provides novel insights into TIL dynamics in the context of NART in breast cancer and demonstrates the potential for artificial intelligence to assist routine pathology. We have identified trends that warrant further interrogation and have a bearing on future radioimmunotherapy trials.

DNA repair-dependent immunogenic liabilities in colorectal cancer: opportunities from errors

Colorectal cancer (CRC) remains one of the major causes of cancer death worldwide. Chemotherapy continues to serve as the primary treatment modality, while immunotherapy is largely ineffective for the majority of CRC patients. Seminal discoveries have emphasized that modifying DNA damage response (DDR) mechanisms confers both cell-autonomous and immune-related vulnerabilities across various cancers. In CRC, approximately 15% of tumours exhibit alterations in the mismatch repair (MMR) machinery, resulting in a high number of neoantigens and the activation of the type I interferon response. These factors, in conjunction with immune checkpoint blockades, collectively stimulate anticancer immunity. Furthermore, although less frequently, somatic alterations in the homologous recombination (HR) pathway are observed in CRC; these defects lead to genome instability and telomere alterations, supporting the use of poly (ADP-ribose) polymerase (PARP) inhibitors in HR-deficient CRC patients. Additionally, other DDR inhibitors, such as Ataxia Telangiectasia and Rad3-related protein (ATR) inhibitors, have shown some efficacy both in preclinical models and in the clinical setting, irrespective of MMR proficiency. The aim of this review is to elucidate how preexisting or induced vulnerabilities in DNA repair pathways represent an opportunity to increase tumour sensitivity to immune-based therapies in CRC.

In vitro-irradiated cancer vaccine enhances anti-tumor efficacy of radiotherapy and PD-L1 blockade in a syngeneic murine breast cancer model

BACKGROUND AND PURPOSE

Local radiotherapy (RT) exerts immunostimulatory effects by inducing immunogenic cell death. However, it remains unknown whether in vitro-irradiated tumor cells can elicit anti-tumor responses and enhance the efficacy of local RT and immune checkpoint inhibitors when injected in vivo.

METHODS AND MATERIALS

We tested the "in vitro-irradiated cancer vaccine (ICV)", wherein tumor cells killed by varying doses of irradiation and their supernatants are intravenously injected. We examined the efficacy of combining local RT (24 Gy in three fractions), PD-L1 blockade, and the ICV in a murine breast cancer model. The immune cell profiles were analyzed via flow cytometry and immunohistochemistry. The cytokine levels were measured by multiplex immunoassays.

RESULTS

The ICV significantly increased the effector memory phenotype and interferon-γ production capacity in splenic CD8+ T cells. The in vitro-irradiated products contained immune response-related molecules. When combined with local RT and PD-L1 blockade, the ICV significantly delayed the growth of irradiated and non-irradiated tumors. The triple combination therapy increased the proportions of CD8+ T cells and effector memory CD8+ T cells while decreasing the proportion of CTLA-4+ exhausted CD8+ T cells within tumor microenvironment. Additionally, plasma level of interferon-γ and proliferation of effector T cells in the spleen and tumor-draining lymph nodes were significantly increased by the triple combination therapy.

CONCLUSIONS

The ICV enhanced the therapeutic efficacy of local RT and PD-L1 blockade by augmenting anti-tumor immune responses. Our findings suggest a therapeutic potential of in vitro-irradiation products of tumor cells.

EDNRA regulates the tumour immune environment and predicts the efficacy and prognosis of cancer immunotherapy

The potential role of endothelin receptor A (EDNRA) in cancer immunotherapy has been demonstrated; however, the mechanism of its therapeutic value remains to be investigated. This study aimed to reveal the potential link between cancer immunotherapy and EDNRA in human tumours. Clinical characteristics and gene expression information were acquired from the Cancer Genome Atlas database. The correlation between EDNRA expression and immune infiltration was analysed by tumour immune estimation resource (TIMER) and tumour-immune system interaction database (TISIDB). EDNRA expression in different cancer types were performed via qPCR. Immunohistochemistry was used to detect the relationships between EDNRA protein and immune checkpoints. The results have founded that EDNRA was differentially expressed in various tumours, and highly associated with patient's age and tumour stage. It is also of high potential prognostic value in predicting patient survival. It has been verified that the EDNRA, JAK-STAT, and TGF-β signalling pathways are involved in cancers. In general, EDNRA positively correlated with immunomodulatory agents, immune cell infiltration, and immunotherapy markers. Immunohistochemical analysis of breast cancer tissues showed that EDNRA was positively correlated with NRP1 expression. Furthermore, patients with low EDNRA levels showed a superior response to immunotherapy. The functional study found that EDNRA expression is upregulated in MDA-MB-231 and HepG2 cells, and knockdown of EDNRA inhibits proliferation and migration of cells. In conclusion, the immunotherapeutic function of EDNRA was elucidated in this study. EDNRA may be an important target in tumour immunotherapy and provide new insights for tumour immunotherapy.

Hypofractionated and intensity-modulated radiotherapy combined with systemic therapy in metastatic hepatocellular carcinoma: A case report

BACKGROUND

Liver cancer treatment is characterized by multidisciplinary participation and coexistence of multiple treatment methods. Hypofractionated and intensity-modulated radiotherapy is a new precise radiotherapy technique applied to the treatment of systemic malignant tumors. There is a lack of understanding of hypofractionated and intensity-modulated radiotherapy combined with systemic therapy in metastatic hepatocellular carcinoma (HCC).

CASE SUMMARY

We report a case of metastatic HCC treated with hypofractionated and intensity-modulated radiotherapy combined with systemic therapy. A 41-year-old man was diagnosed with metastatic HCC (T3N1M1 stage IVB). Because it was found to be in the late stage of cancer and had already metastasized, it was impossible to undergo surgical treatment. In addition to aggressive comprehensive treatment for the primary lesion, local treatment for metastatic cancer can improve the patient's survival potential. Hypofractionated and intensity-modulated radiotherapy can provide a larger single treatment dose within a shorter overall treatment time, and improve the local control rate of the tumor. Follow-up examination demonstrated that the tumor and metastatic lesions had shrunk after therapy. The treatment has showed good efficacy. The patient survived for 18 months without disease progression and stable disease persisted for > 38 months.

CONCLUSION

Targeted therapy and immunotherapy followed by hypofractionated and intensity-modulated radiotherapy are also effective for advanced metastatic HCC.

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.

Investigating tumor immunogenicity in breast cancer: deciphering the tumor immune response to enhance therapeutic approaches

The interplay between immune cells and malignant cells represents an essential chapter in the eradication of breast cancer. This widely distributed and diverse form of cancer represents a major threat to women worldwide. The incidence of breast cancer is related to several risk factors, notably genetic predisposition and family antecedents. Despite progress in treatment modalities varying from surgery and chemotherapy to radiotherapy and targeted therapies, persistently high rates of recurrence, metastasis, and treatment resistance underscore the urgent need for new therapeutic approaches. Immunotherapy has gained considerable ground in the treatment of breast cancer, as it takes advantage of the complex interactions within the tumor microenvironment. This dynamic interplay between immune and tumor cells has become a key point of focus in immunological research. This study investigates the role of various cancer markers, such as neoantigens and immune regulatory genes, in the diagnosis and treatment of breast tumors. Moreover, it explores the future potential of immune checkpoint inhibitors as therapeutically effective agents, as well as the challenges that prevent their efficacy, in particular tumor-induced immunosuppression and the difficulty of achieving tumor specificity.

A self-assembled, genetically engineered, irradiated tumor cell debris vaccine

Vaccine-based therapeutics for cancers face several challenges including lack of immunogenicity and tumor escape pathways for single antigen targets. It has been reported that radiotherapy has an in situ vaccine effect that provides tumor antigens following irradiation, helping to activate antigen-presenting cells (APCs). Herein, a new vaccine approach is developed by combining genetically engineered irradiated tumor cell debris (RTD) and hyaluronic acid (HA), termed HA@RTD. A cancer cell line is developed that overexpresses granulocyte-macrophage colony-stimulating factor (GM-CSF). A hydrogel was developed by covalent conjugation of HA with RTD proteins that acted as a potent vaccine system, the effects which were probed with T cell receptor sequencing. The engineered vaccine activated antitumor immunity responses and prevented tumor growth in mice even with a single immunization. HA@RTD vaccine efficacy was also assessed in therapeutic settings with established tumors and in combination with immune checkpoint blockade.

Hypoxia-Targeted Immunotherapy with PD-1 Blockade in Head and Neck Cancer

Intratumoral hypoxia is associated with tumor progression, aggressiveness, and therapeutic resistance in several cancers. Hypoxia causes cancer cells to experience replication stress, thereby activating DNA damage and repair pathways. MutT homologue-1 (MTH1, also known as NUDT1), a member of the Nudix family, maintains the genomic integrity and viability of tumor cells in the hypoxic tumor microenvironment. Although hypoxia is associated with poor prognosis and can cause therapeutic resistance by regulating the microenvironment, it has not been considered a treatable target in cancer. This study aimed to investigate whether hypoxia-induced MTH1 is a useful target for immunotherapy and whether hypoxic conditions influence the antitumor activity of immune cells. Our results showed that MTH1 expression was elevated under hypoxic conditions in head and neck cancer cell lines. Furthermore, we identified a novel MTH1-targeting epitope peptide that can activate peptide-specific CD4+ helper T cells with cytotoxic activity. The proliferation and cytotoxic activity of T cells were maintained under hypoxic conditions, and PD-1 blockade further augmented the cytotoxicity. These results indicate that MTH1-targeted immunotherapy combined with checkpoint blockade can be an effective strategy for the treatment of hypoxic tumors.

Tertiary lymphoid structures in diseases: immune mechanisms and therapeutic advances

Tertiary lymphoid structures (TLSs) are defined as lymphoid aggregates formed in non-hematopoietic organs under pathological conditions. Similar to secondary lymphoid organs (SLOs), the formation of TLSs relies on the interaction between lymphoid tissue inducer (LTi) cells and lymphoid tissue organizer (LTo) cells, involving multiple cytokines. Heterogeneity is a distinguishing feature of TLSs, which may lead to differences in their functions. Growing evidence suggests that TLSs are associated with various diseases, such as cancers, autoimmune diseases, transplant rejection, chronic inflammation, infection, and even ageing. However, the detailed mechanisms behind these clinical associations are not yet fully understood. The mechanisms by which TLS maturation and localization affect immune function are also unclear. Therefore, it is necessary to enhance the understanding of TLS development and function at the cellular and molecular level, which may allow us to utilize them to improve the immune microenvironment. In this review, we delve into the composition, formation mechanism, associations with diseases, and potential therapeutic applications of TLSs. Furthermore, we discuss the therapeutic implications of TLSs, such as their role as markers of therapeutic response and prognosis. Finally, we summarize various methods for detecting and targeting TLSs. Overall, we provide a comprehensive understanding of TLSs and aim to develop more effective therapeutic strategies.

Predicting radiotherapy efficacy and prognosis in tongue squamous cell carcinoma through an in-depth analysis of a radiosensitivity gene signature

Background

Tongue squamous cell carcinoma (TSCC) is a prevalent tumor that affects many people worldwide. Radiotherapy is a common treatment option, but its efficacy varies greatly. This study seeks to validate the identified gene signature associated with radiosensitivity in TSCC, and its potential in predicting radiotherapy response and prognosis.

Methods

We analyzed 122 TSCC patients from TCGA database using the radiosensitivity signature and classified them into radiosensitive (RS) and radioresistant (RR) groups. Immune infiltration analysis methods were applied to investigate the immune status between different subgroups. Immunophenotype Score (IPS) and pRRophetic algorithm were employed to estimate the efficiency of treatment. A radioresistant TSCC cell line was established by gradually increasing radiation doses. Cell radiosensitivity was evaluated using the CCK-8 and colony formation assays. The expression of radiosensitivity-related genes was validated by qRT-PCR.

Results

Our study validated the predictive capacity of a previously identified "31-gene signature" in the TCGA-TSCC cohort, which effectively stratified patients into RS and RR groups. We observed that the RS group exhibited superior overall survival and progression-free survival rates relative to the RR group when treated with radiotherapy. The RS group was significantly enriched in most immune-related hallmark pathways, and may therefore benefit from immune checkpoint inhibitors. However, the RS group displayed lower sensitivity to first-line chemotherapy. A radioresistant TSCC cell line (CAL-27R) exhibited increased clonogenic potential and cell viability following irradiation, accompanied by downregulation of three radiosensitivity-related genes compared to its parental non-resistant cell (CAL-27). In addition, we constructed and validated a radiosensitivity-related prognostic index (PI) using 4 radiosensitivity-related genes associated with TSCC prognosis.

Conclusion

We assessed the ability of the radiosensitivity gene signature to predict outcomes in TSCC patients. our research provided valuable insights into the molecular pathways associated with radiosensitivity in TSCC and offered clinicians a practical tool to predict patient radiotherapy effectiveness and prognosis.

Reprogramming the tumor immune microenvironment using engineered dual-drug loaded Salmonella

Synergistic combinations of immunotherapeutic agents can improve the performance of anti-cancer therapies but may lead to immune-mediated adverse effects. These side-effects can be overcome by using a tumor-specific delivery system. Here, we report a method of targeted immunotherapy using an attenuated Salmonella typhimurium (SAM-FC) engineered to release dual payloads: cytolysin A (ClyA), a cytolytic anti-cancer agent, and Vibrio vulnificus flagellin B (FlaB), a potent inducer of anti-tumor innate immunity. Localized secretion of ClyA from SAM-FC induces immunogenic cancer cell death and promotes release of tumor-specific antigens and damage-associated molecular patterns, which establish long-term antitumor memory. Localized secretion of FlaB promotes phenotypic and functional remodeling of intratumoral macrophages that markedly inhibits tumor metastasis in mice bearing tumors of mouse and human origin. Both primary and metastatic tumors from bacteria-treated female mice are characterized by massive infiltration of anti-tumorigenic innate immune cells and activated tumor-specific effector/memory T cells; however, the percentage of immunosuppressive cells is low. Here, we show that SAM-FC induces functional reprogramming of the tumor immune microenvironment by activating both the innate and adaptive arms of the immune system and can be used for targeted delivery of multiple immunotherapeutic payloads for the establishment of potent and long-lasting antitumor immunity.

Strategies for overcoming tumour resistance to immunotherapy: harnessing the power of radiation therapy

Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment; yet their efficacy remains variable across patients. This review delves into the intricate interplay of tumour characteristics contributing to resistance against ICI therapy and suggests that combining with radiotherapy holds promise. Radiation, known for its ability to trigger immunogenic cell death and foster an in situ vaccination effect, may counteract these resistance mechanisms, enhancing ICI response and patient outcomes. However, particularly when delivered at high-dose, it may trigger immunosuppressive mechanism and consequent side-effects. Notably, low-dose radiotherapy (LDRT), with its capacity for tumour reprogramming and reduced side effects, offers the potential for widespread application. Preclinical and clinical studies have shown encouraging results in this regard.

Inhibition of DNMTs increases neoantigen-reactive T-cell toxicity against microsatellite-stable colorectal cancer in combination with radiotherapy

The therapeutic efficacy of immunotherapy is limited in the majority of colorectal cancer patients due to the low mutational and neoantigen burdens in this immunogenically "cold" microsatellite stability-colorectal cancer (MSS-CRC) cohort. Here, we showed that DNA methyltransferase (DNMT) inhibition upregulated neoantigen-bearing gene expression in MSS-CRC, resulting in increased neoantigen presentation by MHC class I in tumor cells and leading to increased neoantigen-specific T-cell activation in combination with radiotherapy. The cytotoxicity of neoantigen-reactive T cells (NRTs) to DNMTi-treated cancer cells was highly cytotoxic, and these cells secreted high IFNγ levels targeting MSS-CRC cells after ex vivo expansion of NRTs with DNMTi-treated tumor antigens. Moreover, the therapeutic efficacy of NRTs further increased when NRTs were combined with radiotherapy in vivo. Administration of DNMTi-augmented NRTs and radiotherapy achieved an ∼50 % complete response and extended survival time in an immunocompetent MSS-CRC animal model. Moreover, remarkably, splenocytes from these mice exhibited neoantigen-specific T-cell responses, indicating that radiotherapy in combination with DNMTi-augmented NRTs prolonged and increased neoantigen-specific T-cell toxicity in MSS-CRC patients. In addition, these DNMTi-augmented NRTs markedly increase the therapeutic efficacy of cancer vaccines and immune checkpoint inhibitors (ICIs). These data suggest that a combination of radiotherapy and epi-immunotherapeutic agents improves the function of ex vivo-expanded neoantigen-reactive T cells and increases the tumor-specific cytotoxic effector population to enhance therapeutic efficacy in MSS-CRC.

Tumor cell-intrinsic MELK enhanced CCL2-dependent immunosuppression to exacerbate hepatocarcinogenesis and confer resistance of HCC to radiotherapy

BACKGROUND

The outcome of hepatocellular carcinoma (HCC) is limited by its complex molecular characteristics and changeable tumor microenvironment (TME). Here we focused on elucidating the functional consequences of Maternal embryonic leucine zipper kinase (MELK) in the tumorigenesis, progression and metastasis of HCC, and exploring the effect of MELK on immune cell regulation in the TME, meanwhile clarifying the corresponding signaling networks.

METHODS

Bioinformatic analysis was used to validate the prognostic value of MELK for HCC. Murine xenograft assays and HCC lung metastasis mouse model confirmed the role of MELK in tumorigenesis and metastasis in HCC. Luciferase assays, RNA sequencing, immunopurification-mass spectrometry (IP-MS) and coimmunoprecipitation (CoIP) were applied to explore the upstream regulators, downstream essential molecules and corresponding mechanisms of MELK in HCC.

RESULTS

We confirmed MELK to be a reliable prognostic factor of HCC and identified MELK as an effective candidate in facilitating the tumorigenesis, progression, and metastasis of HCC; the effects of MELK depended on the targeted regulation of the upstream factor miR-505-3p and interaction with STAT3, which induced STAT3 phosphorylation and increased the expression of its target gene CCL2 in HCC. In addition, we confirmed that tumor cell-intrinsic MELK inhibition is beneficial in stimulating M1 macrophage polarization, hindering M2 macrophage polarization and inducing CD8 + T-cell recruitment, which are dependent on the alteration of CCL2 expression. Importantly, MELK inhibition amplified RT-related immune effects, thereby synergizing with RT to exert substantial antitumor effects. OTS167, an inhibitor of MELK, was also proven to effectively impair the growth and progression of HCC and exert a superior antitumor effect in combination with radiotherapy (RT).

CONCLUSIONS

Altogether, our findings highlight the functional role of MELK as a promising target in molecular therapy and in the combination of RT therapy to improve antitumor effect for HCC.

Radiotherapy and immunology

The majority of cancer patients receive radiotherapy during the course of treatment, delivered with curative intent for local tumor control or as part of a multimodality regimen aimed at eliminating distant metastasis. A major focus of research has been DNA damage; however, in the past two decades, emphasis has shifted to the important role the immune system plays in radiotherapy-induced anti-tumor effects. Radiotherapy reprograms the tumor microenvironment, triggering DNA and RNA sensing cascades that activate innate immunity and ultimately enhance adaptive immunity. In opposition, radiotherapy also induces suppression of anti-tumor immunity, including recruitment of regulatory T cells, myeloid-derived suppressor cells, and suppressive macrophages. The balance of pro- and anti-tumor immunity is regulated in part by radiotherapy-induced chemokines and cytokines. Microbiota can also influence radiotherapy outcomes and is under clinical investigation. Blockade of the PD-1/PD-L1 axis and CTLA-4 has been extensively investigated in combination with radiotherapy; we include a review of clinical trials involving inhibition of these immune checkpoints and radiotherapy.

Predictive model based on multiple immunofluorescence quantitative analysis for pathological complete response to neoadjuvant immunochemotherapy in lung squamous cell carcinoma

Objective

This study aims to establish a prediction model for neoadjuvant immunochemotherapy (NICT) in lung squamous cell carcinoma to guide clinical treatment.

Methods

This retrospective study included 50 patients diagnosed with lung squamous cell carcinoma who received NICT. The patients were divided into the pathological complete response (PCR) group and the non-PCR group. HE staining and multiple immunofluorescence (mIF) techniques were utilized to analyze the differences in the immune microenvironment between these groups. LASSO regression and optimal subset regression were employed to identify the most significant variables and construct a prediction model.

Results

The PCR group showed higher densities of lymphocyte nuclei and karyorrhexis based on HE staining. Furthermore, based on mIF analysis, the PCR group showed higher cell densities of CD8+, PD-L1+, and CD8+PD-L1+ in the tumor region, while showing lower cell densities of CD3+Foxp3+, Foxp3+, and CD163+. Logistic univariate analysis revealed CD8+PD-L1+, PD-L1+, CD8+, CD4+LAG-3+, lymphocyte nuclei, and karyorrhexis as significant factors influencing PCR. By using diverse screening methods, the three most relevant variables (CD8+, PD-L1+, and CD8+PD-L1+ in the tumor region) were selected to establish the prediction model. The model exhibited excellent performance in both the training set (AUC=0.965) and the validation set (AUC=0.786). In the validation set, In comparison to the conventional TPS scoring criteria, the model attained superior accuracy (0.85), specificity(0.67), and sensitivity (0.92).

Conclusion

NICT treatment might induce anti-tumor effects by enriching immune cells and reactivating exhausted T cells. CD8+, PD-L1+, and CD8+PD-L1+ cell abundances within the tumor region have been closely associated with therapeutic efficacy. Incorporating these three variables into a predictive model allows accurate forecasting of treatment outcomes and provides a reliable basis for selecting NICT treatment strategies.

Self-Cascade Nanozyme Reactor as a Cuproptosis Inducer Synergistic Inhibition of Cellular Respiration Boosting Radioimmunotherapy

Intrinsic or acquired radioresistance remained an important challenge in the successful management of cancer. Herein, a novel "smart" multifunctional copper-based nanocomposite (RCL@Pd@CuZ) to improve radiotherapy (RT) sensitivity is designed and developed. In this nanoplatform, DSPE-PEG-RGD modified on the liposome surface enhanced tumor targeting and permeability; capsaicin inserted into the phospholipid bilayer improved the hypoxic conditions in the tumor microenvironment (TME) by inhibiting mitochondrial respiration; a Cu MOF porous cube encapsulated in liposome generated highly active hydroxyl radicals (OH·), consumed GSH and promoted cuproptosis by releasing Cu2+; the ultrasmall palladium (Pd) nanozyme within the cubes exhibited peroxidase activity, catalyzing toxic OH· generation and releasing oxygen from hydrogen peroxide; and lastly, Pd, as an element with a relatively high atomic number (Z) enhanced the photoelectric and Compton effects of X-rays. Therefore, RCL@Pd@CuZ enhance RT sensitivity by ameliorating hypoxia, promoting cuproptosis, depleting GSH, amplifying oxidative stress, and enhancing X-ray absorption  , consequently potently magnifying immunogenic cell death (ICD). In a mouse model , RCL@Pd@CuZ combined with RT yielded >90% inhibition compared with that obtained by RT alone in addition to a greater quantity of DC maturation and CD8+ T cell infiltration. This nanoplatform offered a promising remedial modality to facilitate cuproptosis-related cancer radioimmunotherapy.

Neoantigens and cancer-testis antigens as promising vaccine candidates for triple-negative breast cancer: Delivery strategies and clinical trials

Immunotherapy is gaining prominence as a promising strategy for treating triple-negative breast cancer (TNBC). Neoantigens (neoAgs) and cancer-testis antigens (CTAs) are tumor-specific targets originating from somatic mutations and epigenetic changes in cancer cells. These antigens hold great promise for personalized cancer vaccines, as supported by preclinical and early clinical evidence in TNBC. This review delves into the potential of neoAgs and CTAs as vaccine candidates, emphasizing diverse strategies and delivery approaches. It also highlights the current status of vaccination modalities undergoing clinical trials in TNBC therapy. A comprehensive understanding of neoAgs, CTAs, vaccination strategies, and innovative delivery methods is crucial for optimizing neoAg-based immunotherapies in clinical practice.

Neoantigen-augmented iPSC cancer vaccine combined with radiotherapy promotes antitumor immunity in poorly immunogenic cancers

Although irradiated induced-pluripotent stem cells (iPSCs) as a prophylactic cancer vaccine elicit an antitumor immune response, the therapeutic efficacy of iPSC-based cancer vaccines is not promising due to their insufficient antigenicity and the immunosuppressive tumor microenvironment. Here, we found that neoantigen-engineered iPSC cancer vaccines can trigger neoantigen-specific T cell responses to eradicate cancer cells and increase the therapeutic efficacy of RT in poorly immunogenic colorectal cancer (CRC) and triple-negative breast cancer (TNBC). We generated neoantigen-augmented iPSCs (NA-iPSCs) by engineering AAV2 vector carrying murine neoantigens and evaluated their therapeutic efficacy in combination with radiotherapy. After administration of NA-iPSC cancer vaccine and radiotherapy, we found that ~60% of tumor-bearing mice achieved a complete response in microsatellite-stable CRC model. Furthermore, splenocytes from mice treated with NA-iPSC plus RT produced high levels of IFNγ secretion in response to neoantigens and had a greater cytotoxicity to cancer cells, suggesting that the NA-iPSC vaccine combined with radiotherapy elicited a superior neoantigen-specific T-cell response to eradicate cancer cells. The superior therapeutic efficacy of NA-iPSCs engineered by mouse TNBC neoantigens was also observed in the syngeneic immunocompetent TNBC mouse model. We found that the risk of spontaneous lung and liver metastasis was dramatically decreased by NA-iPSCs plus RT in the TNBC animal model. Altogether, these results indicated that autologous iPSC cancer vaccines engineered by neoantigens can elicit a high neoantigen-specific T-cell response, promote tumor regression, and reduce the risk of distant metastasis in combination with local radiotherapy.

Immunosuppressive tumor microenvironment and immunotherapy of hepatocellular carcinoma: current status and prospectives

Hepatocellular carcinoma (HCC) is a major health concern worldwide, with limited therapeutic options and poor prognosis. In recent years, immunotherapies such as immune checkpoint inhibitors (ICIs) have made great progress in the systemic treatment of HCC. The combination treatments based on ICIs have been the major trend in this area. Recently, dual immune checkpoint blockade with durvalumab plus tremelimumab has also emerged as an effective treatment for advanced HCC. However, the majority of HCC patients obtain limited benefits. Understanding the immunological rationale and exploring novel ways to improve the efficacy of immunotherapy has drawn much attention. In this review, we summarize the latest progress in this area, the ongoing clinical trials of immune-based combination therapies, as well as novel immunotherapy strategies such as chimeric antigen receptor T cells, personalized neoantigen vaccines, oncolytic viruses, and bispecific antibodies.

To develop a prognostic model for neoadjuvant immunochemotherapy efficacy in esophageal squamous cell carcinoma by analyzing the immune microenvironment

Objective

The choice of neoadjuvant therapy for esophageal squamous cell carcinoma (ESCC) is controversial. This study aims to provide a basis for clinical treatment selection by establishing a predictive model for the efficacy of neoadjuvant immunochemotherapy (NICT).

Methods

A retrospective analysis of 30 patients was conducted, divided into Response and Non-response groups based on whether they achieved major pathological remission (MPR). Differences in genes and immune microenvironment between the two groups were analyzed through next-generation sequencing (NGS) and multiplex immunofluorescence (mIF). Variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves to establish a predictive model. An additional 48 patients were prospectively collected as a validation set to verify the model's effectiveness.

Results

NGS suggested seven differential genes (ATM, ATR, BIVM-ERCC5, MAP3K1, PRG, RBM10, and TSHR) between the two groups (P < 0.05). mIF indicated significant differences in the quantity and location of CD3+, PD-L1+, CD3+PD-L1+, CD4+PD-1+, CD4+LAG-3+, CD8+LAG-3+, LAG-3+ between the two groups before treatment (P < 0.05). Dynamic mIF analysis also indicated that CD3+, CD8+, and CD20+ all increased after treatment in both groups, with a more significant increase in CD8+ and CD20+ in the Response group (P < 0.05), and a more significant decrease in PD-L1+ (P < 0.05). The three variables most closely related to therapeutic efficacy were selected through LASSO regression and ROC curves: Tumor area PD-L1+ (AUC= 0.881), CD3+PD-L1+ (AUC= 0.833), and CD3+ (AUC= 0.826), and a predictive model was established. The model showed high performance in both the training set (AUC= 0.938) and the validation set (AUC= 0.832). Compared to the traditional CPS scoring criteria, the model showed significant improvements in accuracy (83.3% vs 70.8%), sensitivity (0.625 vs 0.312), and specificity (0.937 vs 0.906).

Conclusion

NICT treatment may exert anti-tumor effects by enriching immune cells and activating exhausted T cells. Tumor area CD3+, PD-L1+, and CD3+PD-L1+ are closely related to therapeutic efficacy. The model containing these three variables can accurately predict treatment outcomes, providing a reliable basis for the selection of neoadjuvant treatment plans.

Neoadjuvant tislelizumab plus stereotactic body radiotherapy and adjuvant tislelizumab in early-stage resectable hepatocellular carcinoma: the Notable-HCC phase 1b trial

Notable-HCC (NCT05185531) is a phase 1b trial, aiming to evaluate the safety and preliminary effectiveness of neoadjuvant PD-1 blockade plus stereotactic body radiotherapy (SBRT) in early-stage resectable hepatocellular carcinoma (HCC). Twenty patients with HCC of BCLC stage 0-A received 3 × Gy SBRT and two cycles of tislelizumab, an anti-PD-1 monoclonal antibody before the curative HCC resection. Primary endpoints were the surgery delay, radiographic and pathological tumor response after the neoadjuvant therapy, safety and tolerability. During the neoadjuvant therapy, treatment-related adverse events (TRAEs) of grade 1-2 occurred in all 20 patients (100%), eight patients (40%) had grade 3 TRAEs, no grade 4 to 5 TRAE occurred, and all resolved without corticosteroids treatment. Per mRECIST, the objective response rate was 63.2% (12/19), with 3 complete response; the disease control rate was 100%. Two (10.5%) patients achieved complete pathological response. No surgery delay occurred. The neoadjuvant therapy did not increase the surgical difficulty or the incidence of complications. Secondary endpoints of disease-free survival and overall survival were not mature at the time of the analysis. Our pilot trial shows that neoadjuvant therapy with anti-PD-1 + SBRT is safe and promotes tumor responses in early-stage resectable HCC.

Multicentric Assessment of Safety and Efficacy of Combinatorial Adjuvant Brain Metastasis Treatment by Intraoperative Radiation Therapy and Immunotherapy

PURPOSE

After surgical resection of brain metastases (BMs), intraoperative radiation therapy (IORT) provides a promising alternative to adjuvant external beam radiation therapy by enabling superior organ-at-risk preservation, reduction of in-hospital times, and timely admission to subsequent systemic treatments, which increasingly comprise novel targeted immunotherapeutic approaches. We sought to assess the safety and efficacy of IORT in combination with immune checkpoint inhibitors (ICIs) and other targeted therapies (TTs).

METHODS AND MATERIALS

In a multicentric approach incorporating individual patient data from 6 international IORT centers, all patients with BMs undergoing IORT were retrospectively assessed for combinatorial treatment with ICIs/TTs and evaluated for toxicity and cumulative rates, including wound dehiscence, radiation necrosis, leptomeningeal spread, local control, distant brain progression (DBP), and estimated overall survival.

RESULTS

In total, 103 lesions with a median diameter of 34 mm receiving IORT combined with immunomodulatory systemic treatment or other TTs were included. The median follow-up was 13.2 (range, 1.2-102.4) months, and the median IORT dose was 25 (range, 18-30) Gy prescribed to the applicator surface. There was 1 grade 3 adverse event related to IORT recorded (2.2%). A 4.9% cumulative radiation necrosis rate was observed. The 1-year local control rate was 98.0%, and the 1-year DBP-free survival rate was 60.0%. Median time to DBP was 5.5 (range, 1.0-18.5) months in the subgroup of patients experiencing DBP, and the cumulative leptomeningeal spread rate was 4.9%. The median estimated overall survival was 26 (range, 1.2 to not reached) months with a 1-year survival rate of 74.0%. Early initiation of immunotherapy/TTs was associated with a nonsignificant trend toward improved DBP rate and overall survival.

CONCLUSIONS

The combination of ICIs/TTs with IORT for resected BMs does not seem to increase toxicity and yields encouraging local control outcomes in the difficult-to-treat subgroup of larger BMs. Time gaps between surgery and systemic treatment could be shortened or avoided. The definitive role of IORT in local control after BM resection will be defined in a prospective trial.

The Next Chapter in Immunotherapy and Radiation Combination Therapy: Cancer-Specific Perspectives

Immunotherapeutic agents have revolutionized cancer treatment over the past decade. However, most patients fail to respond to immunotherapy alone. A growing body of preclinical studies highlights the potential for synergy between radiation therapy and immunotherapy, but the outcomes of clinical studies have been mixed. This review summarizes the current state of immunotherapy and radiation combination therapy across cancers, highlighting existing challenges and promising areas for future investigation.

Tumor neoantigens and tumor immunotherapies

As a high-risk group of patients with cancer, the elderly exhibit limited efficacy with traditional treatments. Immunotherapy emerges as a promising adjunctive therapeutic approach that holds potential in addressing the needs of geriatric patients with cancer. Neoantigens, a unique class of tumor-specific antigens generated by non-synonymous mutations, are garnering increasing attention as targets for immunotherapy in clinical applications. Newly developed technologies, such as second-generation gene sequencing and mass spectrometry, have provided powerful technical support for the identification and prediction of neoantigens. At present, neoantigen-based immunotherapy has been extensively applied in clinical trials and has demonstrated both safety and efficacy, marking the beginning of a new era for cancer immunotherapy. This article reviews the conception, classification, inducers, and screening process of tumor neoantigens, as well as the application prospects and combination therapy strategies of neoantigen-based cancer immunotherapy.

The scheme, and regulative mechanism of pyroptosis, ferroptosis, and necroptosis in radiation injury

Radiotherapy (RT) stands as the primary treatment for tumors, but it inevitably causes damage to normal cells. Consequently, radiation injury is a crucial consideration for radiation oncologists during therapy planning. Cell death including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis play significant roles in tumor treatment. While previous studies elucidated the induction of apoptosis and autophagy by ionizing radiation (IR), recent attention has shifted to pyroptosis, ferroptosis, and necroptosis, revealing their effects induced by IR. This review aims to summarize the strategies employed by IR, either alone or in combination therapy, to induce pyroptosis, ferroptosis, and necroptosis in radiation injury. Furthermore, we explore their effects and molecular pathways, shedding light on their roles in radiation injury. Finally, we summarize the regulative agents for these three types of cell death and their mechanisms. In summary, optimizing radiation dose, dose rate, and combined treatment plans to minimize radiation damage and enhance the killing effect of RT is a key focus.