Immune-Mediated Inhibition of Metastases after Treatment with Local Radiation and CTLA-4 Blockade in a Mouse Model of Breast Cancer

Molecular subtype characteristics and development of prognostic model based on inflammation-related gene in lung adenocarcinoma

As one of the leading causes of death worldwide, lung adenocarcinoma (LUAD) currently lacks satisfactory treatment outcomes. The inflammatory process, closely associated with the formation of the tumor microenvironment and immune evasion, plays a crucial role in LUAD development. This study utilized data from public databases to analyze inflammation-related genes (INF) associated with prognosis in LUAD. Based on differentially expressed INF, molecular subtypes of LUAD were identified. Subsequently, a novel INF scoring system was developed to establish a prognostic model for LUAD patients, assessing its independence and reliability. Comprehensive evaluations, including immune microenvironment infiltration features, somatic mutation characteristics, and differences in immune therapy responsiveness, were conducted to characterize the prognostic model associated with INF. We further selected MMP14 from the screened INF targets for further in vitro experiments. Experiments such as western blot, qRT-PCR, colony-forming assay and Transwell assay confirmed that downregulation of MMP14 could inhibit the cloning, proliferation and invasion of lung cancer cells, thus confirming the results of bioinformatics. Our findings provide evidence from a new perspective on the role of inflammation in LUAD and offer new insights for clinical precision and personalized therapy.

Mitigating radioresistance mechanisms by polymer-lipid manganese dioxide nanoparticles enhances immunogenic cell death and antitumor immune response to facilitate abscopal effect in breast tumor models

Breast cancer is the most diagnosed cancer and the second leading cause of cancer death in women. Although treatments with major anti-cancer modalities are largely successful, resistance to treatments including widely applied radiation therapy (RT) can occur due largely to the multifaceted mechanisms in the tumor microenvironment (TME). The present work investigated the ability of Polymer-Lipid-Manganese Dioxide Nanoparticles (PLMD) to overcome hypoxia-associated radioresistant mechanisms and enhance RT-induced immunogenic cell death (ICD) and anti-tumor immunity for inhibiting growth of primary and distant tumors (the abscopal effect). The results showed that PLMD plus RT significantly inhibited the clonogenic survival of murine EMT6 and 4T1 breast cancer cells under hypoxic condition compared to RT alone. Analysis of ICD biomarkers revealed that PLMD profoundly enhanced RT-induced ICD compared to RT alone in EMT6 and 4T1 cells under hypoxic conditions but not under normoxic conditions. In a syngeneic murine breast tumor model with 4T1 orthotopic tumor, the PLMD treatment reduced tumor hypoxia significantly; PLMD + RT combination therapy increased infiltration of cytotoxic CD8+ T cells and CD86+ macrophages and decreased infiltration of immunosuppressive Tregs and CD163+ macrophages, as compared to RT alone. Importantly, the PLMD + RT treatment generated an abscopal effect in a tumor growth experiment using a double-tumor model, where the growth of an untreated tumor was inhibited by treatment of a tumor grown on the opposite side. Overall, the PLMD + RT induced an anti-tumor immune response that inhibited both primary and distant tumor growths and extended median survival in the tumor model.

Neoadjuvant with low-dose radiotherapy, tislelizumab, albumin-bound paclitaxel, and cisplatin for resectable locally advanced head and neck squamous cell carcinoma: phase II single-arm trial

Although pathological complete response (pCR) and major pathological response (MPR) rates of neoadjuvant immunotherapy combined with chemotherapy in head and neck squamous cell carcinoma (HNSCC) trials remain suboptimal, emerging evidence highlights the synergistic potential of combining low-dose radiotherapy with immunotherapy to promote the efficacy of immunotherapy. This phase II, open-label, single-arm, multicenter trial (NCT05343325) enrolled 28 patients with untreated stage III-IVB HNSCC (NeoRTPC02). Patients received neoadjuvant low-dose radiotherapy, the programmed death-1 (PD-1) inhibitor tislelizumab, albumin-bound paclitaxel, and cisplatin for two cycles, followed by radical resection ~4 weeks after treatment completion. The primary endpoint, pCR rate, was achieved in 14 of 23 patients (60.9%; 23/28, 82.1% of the total cohort underwent surgery). Secondary endpoints included MPR rate (21.7%, 5/23), R0 resection rate (100%), and objective response rate (64.3%; 18/28). Treatment-related adverse events were manageable, with grade 3 or 4 treatment-related adverse events occurring in 10 (35.7%) patients. No surgical delays were observed. Single-cell RNA sequencing revealed remodeling of the HNSCC tumor microenvironment, which may correlate with improved clinical outcomes. This trial met the pre-specified primary endpoint, demonstrating a high pCR rate with promising efficacy and manageable toxicity in locally advanced HNSCC.

In Situ Cancer Vaccines: Redefining Immune Activation in the Tumor Microenvironment

Cancer is one of the leading causes of mortality worldwide. Nanomedicines have significantly improved life expectancy and survival rates for cancer patients in current standard care. However, recurrence of cancer due to metastasis remains a significant challenge. Vaccines can provide long-term protection and are ideal for preventing bacterial and viral infections. Cancer vaccines, however, have shown limited therapeutic efficacy and raised safety concerns despite extensive research. Cancer vaccines target and stimulate responses against tumor-specific antigens and have demonstrated great potential for cancer treatment in preclinical studies. However, tumor-associated immunosuppression and immune tolerance driven by immunoediting pose significant challenges for vaccine design. In situ vaccination represents an alternative approach to traditional cancer vaccines. This strategy involves the intratumoral administration of immunostimulants to modulate the growth and differentiation of innate immune cells, such as dendritic cells, macrophages, and neutrophils, and restore T-cell activity. Currently approved in situ vaccines, such as T-VEC, have demonstrated clinical promise, while ongoing clinical trials continue to explore novel strategies for broader efficacy. Despite these advancements, failures in vaccine research highlight the need to address tumor-associated immune suppression and immune escape mechanisms. In situ vaccination strategies combine innate and adaptive immune stimulation, leveraging tumor-associated antigens to activate dendritic cells and cross-prime CD8+ T cells. Various vaccine modalities, such as nucleotide-based vaccines (e.g., RNA and DNA vaccines), peptide-based vaccines, and cell-based vaccines (including dendritic, T-cell, and B-cell approaches), show significant potential. Plant-based viral approaches, including cowpea mosaic virus and Newcastle disease virus, further expand the toolkit for in situ vaccination. Therapeutic modalities such as chemotherapy, radiation, photodynamic therapy, photothermal therapy, and Checkpoint blockade inhibitors contribute to enhanced antigen presentation and immune activation. Adjuvants like CpG-ODN and PRR agonists further enhance immune modulation and vaccine efficacy. The advantages of in situ vaccination include patient specificity, personalization, minimized antigen immune escape, and reduced logistical costs. However, significant barriers such as tumor heterogeneity, immune evasion, and logistical challenges remain. This review explores strategies for developing potent cancer vaccines, examines ongoing clinical trials, evaluates immune stimulation methods, and discusses prospects for advancing in situ cancer vaccination.

Stereotactic radiosurgery for patients with brain metastases: current principles, expanding indications and opportunities for multidisciplinary care

The management of brain metastases is challenging and should ideally be coordinated through a multidisciplinary approach. Stereotactic radiosurgery (SRS) has been the cornerstone of management for most patients with oligometastatic central nervous system involvement (one to four brain metastases), and several technological and therapeutic advances over the past decade have broadened the indications for SRS to include polymetastatic central nervous system involvement (>4 brain metastases), preoperative application and fractionated SRS, as well as combinatorial approaches with targeted therapy and immune-checkpoint inhibitors. For example, improved imaging and frameless head-immobilization technologies have facilitated fractionated SRS for large brain metastases or postsurgical cavities, or lesions in proximity to organs at risk. However, these opportunities come with new challenges and questions, including the implications of tumour histology as well as the role and sequencing of concurrent systemic treatments. In this Review, we discuss these advances and associated challenges in the context of ongoing clinical trials, with insights from a global group of experts, including recommendations for current clinical practice and future investigations. The updates provided herein are meaningful for all practitioners in clinical oncology.

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.

The Proimmunomodulatory and Anti-immunomodulatory Effects of Radiotherapy in Oncologic Care

The abscopal effect in radiotherapy (RT) refers to the phenomenon where localized radiation treatment causes regression of distant, nonirradiated tumors. Although rare, recent research shows that combining radiation with immunotherapies, such as immune checkpoint inhibitors, can enhance this effect. The interaction between radiation-induced cell death, immune responses, and the tumor microenvironment manifests in competing biologic mechanisms resulting in complex immunologic outcomes. In order to maximize the therapeutic advantages of the immunogenic effect of RT in the future, further studies are needed to fully understand its biologic underpinnings.

Advances in radiation therapy for HCC: Integration with liver-directed treatments

HCC is the fourth leading cause of cancer-related mortality with increasing incidence worldwide. Historically, treatment for early disease includes liver transplantation, surgical resection, and/or other local therapies, such as thermal ablation. As a result of technical advances and high-quality prospective data, the use of definitive external beam radiotherapy with ablative doses has emerged. Intermediate-stage disease has been generally addressed with arterially directed therapies (eg, chemoembolization or radioembolization) and external beam radiotherapy, while advanced stages have been addressed by systemic therapy or best supportive care. The role of each local/locoregional therapy has rapidly evolved in the context of novel pharmacotherapies, including immunotherapies and antiangiogenic agents. The combinations, indications, and timing of treatments vary widely among specialties and geographies. Here, we aim to synthesize the best quality evidence available regarding the efficacy and safety of different liver-directed modalities, with a focus on recent prospective clinical data of external beam radiotherapy within the context of other available liver-directed therapies across Barcelona Liver Classification (BCLC) stages.

Tumor Microenvironment Dynamics of Triple-Negative Breast Cancer Under Radiation Therapy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of estrogen receptors (ER), progesterone receptors (PR), and HER2 expression. While TNBC is relatively less common, accounting for only 10-15% of initial breast cancer diagnosis, due to its aggressive nature, it carries a worse prognosis in comparison to its hormone receptor-positive counterparts. Despite significant advancements in the screening, diagnosis, and treatment of breast cancer, TNBC remains an important public health burden. Following treatment with chemotherapy, surgery, and radiation, over 40% of TNBC patients experience relapse within 3 years and achieve the least benefit from post-mastectomy radiation. The tumor microenvironment environment (TME) is pivotal in TNBC initiation, progression, immune evasion, treatment resistance, and tumor prognosis. TME is a complex network that consists of immune cells, non-immune cells, and soluble factors located in the region adjacent to the tumor that modulates the therapeutic response differentially between hormone receptor-positive breast cancer and TNBC. While the mechanisms underlying the radiation resistance of TNBC remain unclear, the immunosuppressive TME of TNBC has been implicated in chemotherapeutic resistance. Radiation therapy (RT) is known to alter the TME; however, immune changes elicited by radiation are poorly characterized to date, and whether these immune changes contribute to radiation resistance remains unknown. This review delves into the distinct characteristics of the TNBC TME, explores how RT influences TME dynamics, and examines mechanisms underlying tumor radiosensitization, radioresistance, and immune responses.

Low-dose irradiation of the gut improves the efficacy of PD-L1 blockade in metastatic cancer patients

The mechanisms governing the abscopal effects of local radiotherapy in cancer patients remain an open conundrum. Here, we show that off-target intestinal low-dose irradiation (ILDR) increases the clinical benefits of immune checkpoint inhibitors or chemotherapy in eight retrospective cohorts of cancer patients and in tumor-bearing mice. The abscopal effects of ILDR depend on dosimetry (≥1 and ≤3 Gy) and on the metabolic and immune host-microbiota interaction at baseline allowing CD8+ T cell activation without exhaustion. Various strains of Christensenella minuta selectively boost the anti-cancer efficacy of ILDR and PD-L1 blockade, allowing emigration of intestinal PD-L1-expressing dendritic cells to tumor-draining lymph nodes. An interventional phase 2 study provides the proof-of-concept that ILDR can circumvent resistance to first- or second-line immunotherapy in cancer patients. Prospective clinical trials are warranted to define optimal dosimetry and indications for ILDR to maximize its therapeutic potential.

Combining Radioembolization and Immune Checkpoint Inhibitors for the Treatment of Hepatocellular Carcinoma: The Quest for Synergy

Hepatocellular carcinoma is a leading and increasing contributor to cancer-related death worldwide. Recent advancements in both liver-directed therapies in the form of yttrium-90 (90Y) radioembolization (RE) and systemic therapy in the form of immune checkpoint inhibitors (ICI) have expanded treatment options for patients with an otherwise poor prognosis. Despite these gains, ICIs and 90Y-RE each have key limitations with low objective response rates and persistent hazard of out-of-field recurrence, respectively, and overall survival remains low. However, each therapy's strength may mitigate the other's weakness, making them potentially ideal partners for combination treatment strategies. This review discusses the scientific and clinical rationale for combining 90Y-RE with ICIs, highlights early clinical trial data on its safety and effectiveness, and proposes key issues to be addressed in this emerging field. With optimal strategies, combination therapies can potentially result in increasing likelihood of durable and curative outcomes in later stage patients.

Advances in diagnostic and therapeutic applications of mismatch repair loss in cancer

Mismatch repair (MMR) is a highly conserved, fundamental DNA damage repair pathway that maintains genomic fidelity during cell replication. MMR dysregulation contributes to tumor formation by promoting genomic instability thereby increasing the frequency of potentially oncogenic mutational events. Therefore, MMR dysregulation, in its tumor suppressor role, is largely studied in the context of genomic instability and associated response to immune checkpoint blockade therapies. However, a growing body of literature suggests that the impact of MMR dysregulation on tumor phenotypes is more nuanced than a concerted impact on genomic stability. Rather, loss of individual MMR genes promotes distinct cancer-relevant biological phenotypes, and these phenotypes are further modulated by the tissue of tumor origin. Here, we explore relevant literature and review the prognostic and predictive significance of these non-canonical discoveries.

Radiotherapy-resistant prostate cancer cells escape immune checkpoint blockade through the senescence-related ataxia telangiectasia and Rad3-related protein

BACKGROUND

The majority of patients with prostate cancer (PCa) exhibit intrinsic resistance to immune checkpoint blockade (ICB) following radiotherapy (RT). This resistance is generally attributed to the limited antigen presentation of heterogeneous cells within tumors. Here, we aimed to isolate and characterize these diverse subgroups of tumor post-RT to understand the molecular mechanisms of their resistance to ICB.

METHODS

Single-cell RNA-sequencing (scRNA-seq) was used to profile senescent cancer cell clusters induced by RT in LNCaP cells. The expression and phosphorylation levels of ataxia telangiectasia and Rad3-related protein (ATR) were assessed by immunohistochemistry in clinical samples from patients with or without RT. Co-immunoprecipitation, mutagenesis, and Western blotting were used to measure the interactions between proteins. Xenograft experiments were performed to assess the tumor immune response in the mice.

RESULTS

We identified a subset of PCa cells that exhibited resistance to RT, characterized by a reduced antigen presentation capability, which enhanced their ability to evade immune detection and resist cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade. scRNA-seq revealed that the senescent state was a transient phase of PCa cells post-RT, particularly in CTLA-4 blockade treatment-resistant cells. This state was marked by increased cytosolic ATR level. Cytosolic ATR phosphorylated CD86 in its cytosolic domain and enhanced the interaction between CD86 and its E3 ligase MARCH1 through electrostatic attraction. Depletion or inhibition of Atr increased the sensitivity to immune attack and improved responses to anti-Ctla-4 antibody treatment in a mouse model.

CONCLUSIONS

Our findings indicate that the activation of cytosolic ATR, which is associated with cellular senescence, impedes the effectiveness of combined RT and ICB treatments. This discovery may provide valuable insights for improving the efficacy of combined RT and ICB therapies in PCa.

A retrospective study of radiotherapy combined with immunotherapy for patients with baseline brain metastases from non-small cell lung cancer

This multi-center retrospective study aimed to evaluate the safety and efficacy of first-line immunotherapy in non-small-cell lung cancer (NSCLC) patients with brain metastases (BM). The study included 138 patients treated with immune checkpoint inhibitors (ICIs), either alone or in combination with brain radiotherapy (BRT), from 2020 to October 2023. Intracranial overall response rate (iORR), overall response rate (ORR), progression-free survival (PFS), intracranial progression-free survival (iPFS), overall survival (OS) and treatment-related toxicities were evaluated. Although patients receiving ICIs plus BRT showed a trend toward longer OS compared with ICI alone, the difference was not statistically significant (P = 0.201). Among 82 patients with available data, the iORR was 49.1% (35-63) in the ICIs alone group, and 75.9% (56-90) in the ICIs + BRT group. Notably, in patients requiring corticosteroids or mannitol, combination therapy was associated with a better prognosis (P = 0.05). We found that the iORR of patients treated with ICIs + BRT was improved and did not increase the incidence of serious adverse events (SAEs). Besides, the combination of ICIs and BRT improved the survival rate of subgroups of patients using corticosteroids.

The Roles of Myeloid Cells in Breast Cancer Progression

This chapter reviews tumor-associated myeloid cells, including macrophages, neutrophils, and other innate immune cells, and their multifaceted roles in supporting breast cancer progression and metastasis. In primary tumors, myeloid cells play key roles in promoting tumor epithelial-mesenchymal transition (EMT) and invasion. They can facilitate intravasation (entry into the bloodstream) and colonization, disrupting the endothelial cell layer and reshaping the extracellular matrix. They can also stimulate angiogenesis, suppress immune cell responses, and enhance cancer cell adaptability. In the bloodstream, circulating myeloid cells enable the survival of disseminated tumor cells via immunosuppressive effects and physical shielding. At the metastatic sites, they prime the premetastatic niche, facilitate tumor cell extravasation, and support successful colonization and outgrowth. Mechanistically, myeloid cells enhance cancer cell survival, dormancy escape, proliferation, and mesenchymal-epithelial transition (MET). Nonetheless, substantial gaps in our understanding persist regarding the functional and spatiotemporal diversity, as well as the evolutionary patterns, of myeloid cells during metastatic progression. Myeloid cell plasticity and differential responses to therapies present key barriers to successful treatments. Identifying specific pro-tumoral myeloid cell subpopulations and disrupting their interactions with cancer cells represent promising therapeutic opportunities. Emerging evidence suggests combining immunomodulators or stromal normalizers with conventional therapies could help overcome therapy-induced immunosuppression and improve patient outcomes. Overall, further elucidating myeloid cell heterogeneity and function throughout the process of breast cancer progression and metastasis will enable more effective therapeutic targeting of these critical stromal cells.

Summary from the NCI clinical trials planning meeting on next generation of clinical trials in non-muscle invasive bladder cancer. Bladder Cancer 2025;11:23523735251319185. [PMID: 40034245 PMCID: PMC11863732 DOI: 10.1177/23523735251319185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

The National Cancer Institute organized a virtual Clinical Trials Planning Meeting (CTPM) on 'Defining the next generation of clinical trials with combination therapies in non-muscle invasive bladder cancer (NMIBC)' led by the Bladder Cancer Task Force of the NCI Genitourinary Cancers Steering Committee. The purpose of this meeting was to accelerate advances in clinical trials for patients with high-risk NMIBC. The meeting delivered a multidisciplinary expert consensus on optimal strategies for next-generation clinical trial designs in NMIBC with prioritization of combination therapies. Two clinical trial concepts were developed for potential implementation within the National Clinical Trials Network.

Immunogenicity of cell death and cancer immunotherapy with immune checkpoint inhibitors

While immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized the clinical management of various malignancies, a large fraction of patients are refractory to ICIs employed as standalone therapeutics, necessitating the development of combinatorial treatment strategies. Immunogenic cell death (ICD) inducers have attracted considerable interest as combinatorial partners for ICIs, at least in part owing to their ability to initiate a tumor-targeting adaptive immune response. However, compared with either approach alone, combinatorial regimens involving ICD inducers and ICIs have not always shown superior clinical activity. Here, we discuss accumulating evidence on the therapeutic interactions between ICD inducers and immunotherapy with ICIs in oncological settings, identify key factors that may explain discrepancies between preclinical and clinical findings, and propose strategies that address existing challenges to increase the efficacy of these combinations in patients with cancer.

Synergistic Anti-Tumor Effects of Newcastle Disease Virus and Doxorubicin: Evidence from A Murine Breast Cancer Model

BACKGROUND

Despite the recent advances in the diagnosis and treatment of breast cancer, triple-negative breast cancer (TNBC) remains a clinical challenge due to its aggressive nature and resistance to conventional therapies. Virotherapy has emerged as a promising cancer treatment strategy, leveraging the ability of viruses to specifically target and replicate in cancerous cells. This study evaluated the oncolytic potential of a combined therapeutic strategy, utilizing Newcastle disease virus (NDV) and Doxorubicin hydrochloride (Dox) both in vitro and in vivo.

METHODS

The in vitro experiments involved exposing human and mouse TNBC cell lines (MDA-MB-231 and 4T1, respectively) to NDV and Dox, individually or in combination. Cell viability assays and flow cytometry analyses were conducted to assess the synergistic effects of NDV and Dox on regulating breast cancer cell behavior in vitro. Furthermore, the immune-stimulating potential of NDV was investigated by examining its effects on dendritic cell (DC) maturation using flow cytometry and T cell proliferation. The in vitro anti-tumor effects of NDV were examined in both parental and tamoxifen-resistant cancer cells to assess its efficacy against chemoresistance. Animal models of breast cancer were treated with NDV in combination with Dox. The body weight changes, tumor volume, and survival rates of the mice were monitored throughout the study. Histopathological analyses were conducted to evaluate the potential toxic effects of the treatments.

RESULTS

Based on the MTT results, NDV at optimal concentrations synergized the effect of Dox to reduce the viability of both MDA-MB231 and 4T1 cell lines (Isobologram combination index of less than 1). Additionally, individual treatment with NDV was able to significantly reduce the viability of patient-derived breast cancer cells, compared to the untreated control (P < 0.05) without affecting the cells of normal adjacent tissue. Furthermore, a combination of NDV and Dox significantly enhanced the percentage of early and late apoptotic cells in MDA-MB-231 (P < 0.0001) and late apoptotic cells in 4T1 (P < 0.0001), in comparison with individual treatment with these agents. Flow cytometry results showed that, compared to wild type MDA-MB-231 cells, NDV-infected MDA-MB-231 cells were better inducers of T cell proliferation and DC maturation as evidenced by increased proliferation index (P < 0.05) and elevated expression of CD1a, CD83, and CD86 (P < 0.0001), respectively. Moreover, co-treatment of both wild-type and (tamoxifen) TAM-resistant MCF-7/TAMR-1 cells with TAM and NDV significantly reduce the viability of the cancer cells (P < 0.0001). In tumor-bearing mice locally engrafted with 4T1 cells, combined treatment of NDV and Dox exhibited a marked reduction in median tumor volume compared to the control group, validating our in vitro findings on their synergistic anti-tumor effects. These findings suggest that combining NDV with Dox can effectively inhibit tumor progression and has the potential to reduce the dose, and consequently the toxic side-effects, of Dox in breast cancer therapy.

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.

Immuno-PET Imaging of CD93 Expression with 64Cu-Radiolabeled NOTA-mCD93 ([64Cu]Cu-NOTA-mCD93) and Insulin-Like Growth Factor Binding Protein 7 ([64Cu]Cu-NOTA-IGFBP7)

CD93 is overexpressed in multiple solid tumor types, serving as a novel target for antiangiogenic therapy. The goal of this study was to develop a 64Cu-based positron emission tomography (PET) tracer for noninvasive imaging of CD93 expression. Antimouse-CD93 mAb (mCD93) and the CD93 ligand IGFBP7 were conjugated to a bifunctional chelator, p-isothiocyanatobenzyl-1,4,7-triazacyclononane-1,4,7-triacetic acid (p-SCN-NOTA) and labeled with 64Cu. To evaluate the pharmacokinetic properties and tumor-targeting efficacy of [64Cu]Cu-NOTA-mCD93 and [64Cu]Cu-NOTA-IGFBP7, PET imaging and biodistribution were performed on both 4T1 murine breast tumor-bearing mice and MDA-MB-231 human breast tumor-bearing mice. The tumor model HT1080-FAP, which does not overexpress CD93, was used as a negative control. Fluorescent immunostaining was conducted on different tissues to correlate radiotracer uptake with CD93 expression. 64Cu-labeling was achieved with high yield and specific activity. Serial PET imaging revealed that the in vivo performance of [64Cu]Cu-NOTA-IGFBP7 was superior to that of [64Cu]Cu-NOTA-mCD93, and that the tracer [64Cu]Cu-NOTA-IGFBP7 exhibited elevated tumor uptake values and excellent tumor retention in MDA-MB-231 mice, rather than in 4T1 murine mice. The MDA-MB-231 tumor uptake of [64Cu]Cu-NOTA-IGFBP7 was 2.85 ± 0.15, 3.69 ± 0.60, 6.91 ± 0.88, and 6.35 ± 0.55%ID/g at 1, 4, 24, and 48 h p.i., respectively, which were significantly higher than that in the CD93-negative HT1080-FAP tumor (0.73 ± 0.15, 0.97 ± 0.31, 1.00 ± 0.07, and 1.02 ± 0.11%ID/g, respectively). The significant difference between positive and negative tumors indicated [64Cu]Cu-NOTA-IGFBP7 was specifically binding to CD93. Biodistribution data as measured by gamma counting were consistent with the PET analysis. Ex vivo histology further confirmed the high CD93 expression on MDA-MB-231 tumor tissues. Herein, we prepared two novel radiotracers, [64Cu]Cu-NOTA-mCD93 and [64Cu]Cu-NOTA-IGFBP7, for the first immune-PET imaging of CD93 expression. Our results suggest that [64Cu]Cu-NOTA-IGFBP7 is a more potential radiotracer for visualizing angiogenesis due to its sensitive, persistent, and CD93-specific characteristics.

The integration of radiotherapy with systemic therapy in advanced triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with high aggressiveness and poor prognosis. For patients who have undergone multiple treatments, systemic drug therapy often presents challenges with limited efficacy and significant side effects. Radiotherapy, a pivotal local treatment, has shown substantial local control benefits in patients with inoperable locally advanced or metastatic disease. Clinical evidence suggests that integrating systemic therapy with locoregional radiotherapy can confer survival advantages in advanced malignancies. Within multidisciplinary treatment, the synergy between radiotherapy and systemic therapies shows promise for enhancing outcomes and extending survival. This review synthesizes recent advances in combining radiotherapy and systemic therapy in managing advanced TNBC, focusing on preclinical and clinical evidence regarding efficacy and safety. By reviewing these advancements, we aim to identify novel therapeutic strategies and integrate clinical evidence to inform best practices in TNBC management, ultimately improving patient outcomes.

A combination of lymphatic drug delivery of anti-CTLA-4 antibody and local radiotherapy for solid-tumor treatment

The combination of radiotherapy and immunotherapy is a promising approach that has been shown in clinical trials to improve significantly survival and response rates compared with monotherapy against solid tumor. Since anti-CTLA-4 antibodies block immunosuppressive signals mainly in the lymph nodes (LNs), efficient drug delivery to the lymphatic system is desirable. However, the immune checkpoint inhibitors, especially anti-CTLA-4 are currently administered intravenously (i.v.), resulting in limited efficacy in controlling solid tumor and inhibiting metastases, and the method of administration has not been optimized. Here, we show that a combination of local radiotherapy and administration of anti-CTLA-4 antibodies using a lymphatic drug delivery system (LDDS) suppresses solid tumor and metastases. We compared the efficacy of LDDS-based immunotherapy or radioimmunotherapy with i.v. administration in a solid-tumor model created by subcutaneous inoculation into LN-swollen mice with osteosarcoma cells. Tumor-bearing mice were divided into various groups (no treatment, immunotherapy [i.v. or LDDS], radiotherapy, and radioimmunotherapy [i.v. or LDDS]) and were observed for 28 days. Immunotherapy was administered with a cumulative dose of 10 mg/kg of anti-CTLA-4 monoclonal antibody, and radiotherapy was administered with a cumulative 8 Gy of fractionated X-ray irradiation. For immunotherapy alone, LDDS provided slight tumor growth inhibition but did not inhibit distant metastasis. For radioimmunotherapy, however, tumor growth was delayed and distant metastasis was suppressed compared with radiotherapy alone. In particular, the LDDS group achieved a high tumor-suppressive effect with T cell-mediated immune activity, indicating the efficacy of LDDS in radioimmunotherapy.

Advances and challenges in immunotherapy for locally advanced nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a prevalent malignant tumor of the head and neck, with approximately 70 % of patients being diagnosed at a locally advanced stage. Despite the responsiveness to radiotherapy and chemotherapy, the 5-year survival rate of locally advanced NPC (LANPC) remains at approximately 80 %. Hence, there is an urgent need for novel treatment strategies to improve the prognosis of patients with LANPC. Numerous studies have illustrated the efficacy of immune checkpoint inhibitors (ICIs) in recurrent/metastatic NPC. Hence, the potential of immunotherapy for LANPC is under investigation. Using the Web of Clinical Trials, we identified 84 relevant trials exploring immunotherapy for NPC, encompassing 17 trials focusing on ICIs for LANPC. Preliminary findings from several trials suggest that adding ICIs into the primary treatment for LANPC significantly enhances the objective response rate and progression-free survival, with manageable safety profiles. However, the type, dosage, and timing of integration (induction phase, concurrent phase, and adjuvant phase) of ICIs into standard primary treatment of LANPC varies among these trials and further researches are warranted. This review provides an overview of immunotherapy principles in NPC, discusses recent advances and challenges associated with ICIs in the primary treatment for LANPC derived from published and ongoing clinical trials, and outlines the current landscape of other immunotherapies in LANPC, such as adoptive cell therapy, immunomodulatory agents, and tumor vaccines in LANPC. These insights aim to inform clinical practice and guide future researches.

Advantages of single high-dose radiation therapy compared with conventional fractionated radiation therapy in overcoming radioresistance

BACKGROUND

Radioresistance is a major clinical challenge in cancer treatment, as it reduces the effectiveness of radiation therapy (RT). While advances in radiation delivery have enabled the clinical use of high-dose hypofractionated RT, its impact on radioresistant tumors remains unclear. This study aimed to compare the effects of single high-dose RT with conventional fractionated RT on radioresistant breast cancer cells and explore the underlying mechanisms.

METHODS

Radioresistant cell lines were previously established by exposing SK-BR-3 and MCF-7 cells to 48 Gy and 70 Gy of radiation, respectively, in multiple fractions. We compared the effects of 2 Gy × 5 and 7 Gy × 1 fractions on these cells using clonogenic survival assays and western blot analysis. In vivo antitumor effects were assessed in SR tumor-bearing BALB/c mice irradiated with either 2 Gy × 5 or 7 Gy × 1 fractions.

RESULTS

7 Gy x1 was more efficient at killing radioresistant breast cancer cells than 2 Gy x5. Furthermore, the 7 Gy x1 fraction produced higher levels of reactive oxygen species (ROS) and decreased the expression of radioresistance factors such as p-STAT3, ACSL4, FOXM1, RAD51, Bcl-xL, and survivin. Consistent with the in vitro studies, the 7 Gy × 1 fraction also showed superior antitumor effects in SR tumor-bearing BALB/c mice.

CONCLUSIONS

Single high-dose RT offers superior advantages over conventional fractionated RT in regard to overcoming radioresistance, supporting its potential as a promising treatment for recurrent tumors.

Cancer Vaccines: Recent Insights and Future Directions

The field of cancer immunotherapy has seen incredible advancements in the past decades. mRNA-based cancer vaccines generating de novo T cell responses, particularly against tumor-specific antigens (TSAs), have demonstrated promising clinical outcomes and overcome diverse challenges. Despite the high potential of neoantigens to provide personalized immunotherapies through their tumor specificity and immunogenicity, challenges related to the scarcity of immunogenic neoepitopes have prompted continuous research towards finding new tumor-associated antigens (TAAs) and broader therapeutic frameworks, which may now learn from the genuine successes obtained with neoantigens. As an example, human endogenous retroviruses (HERVs) have emerged as potential alternatives to tumor neoantigens due to their high tumoral expression and ability to elicit both T cell reactivity and B cell responses associated with the efficacy of existing immunotherapies. This review aims to assess the status and limitations of TSA-directed mRNA cancer vaccines and the lessons that can be derived from these and checkpoint inhibitor studies to guide TAA vaccine development. We expect that shared B cell, CD4 and CD8 T cell antigen presentation will be key to stimulate continuous T cell expansion and efficacy for tumors that do not contain pre-existing tertiary lymphoid structures. When these structures are present in highly mutated tumors, the current checkpoint-based immunotherapies show efficacy even in immune privileged sites, and vaccines may hold the key to broaden efficacy to more tumor types and stages.

Leptomeningeal metastases from solid tumors: A Society for Neuro-Oncology and American Society of Clinical Oncology consensus review on clinical management and future directions

Leptomeningeal metastases (LM) are increasingly becoming recognized as a treatable, yet generally incurable, complication of advanced cancer. As modern cancer therapeutics have prolonged the lives of patients with metastatic cancer, specifically in patients with parenchymal brain metastases, treatment options, and clinical research protocols for patients with LM from solid tumors have similarly evolved to improve survival within specific populations. Recent expansions in clinical investigation, early diagnosis, and drug development have given rise to new unanswered questions. These include leptomeningeal metastasis biology and preferred animal modeling, epidemiology in the modern cancer population, ensuring validation and accessibility of newer leptomeningeal metastasis diagnostics, best clinical practices with multimodality treatment options, clinical trial design and standardization of response assessments, and avenues worthy of further research. An international group of multi-disciplinary experts in the research and management of LM, supported by the Society for Neuro-Oncology and American Society of Clinical Oncology, were assembled to reach a consensus opinion on these pressing topics and provide a roadmap for future directions. Our hope is that these recommendations will accelerate collaboration and progress in the field of LM and serve as a platform for further discussion and patient advocacy.

Combination of radiotherapy and immunotherapy in duality with the protumoral action of radiation

Radiotherapy is widely used to treat various cancers. Its combination with immune checkpoint inhibitors is intensively studied preclinically and clinically. Although the first results were very encouraging, the number of patients who respond positively remains low, and the therapeutic benefit is often temporary. This review summarizes how radiation can stimulate an antitumor immune response and its combination with immunotherapy based on inhibiting immune checkpoints. We will provide an overview of radiotherapy parameters that should be better controlled to avoid downregulating the antitumor immune response. The low response rate of combining radiotherapy and immunotherapy could, at least in part, be caused by the stimulation of cancer cell invasion and metastasis development that occur at similar doses and number of radiation fractions. To end on a positive note, we explore how a targeted inhibition of the inflammatory cytokines induced by radiation with a cyclooxygenase-2 inhibitor could both support an antitumor immune response and block radiation-induced metastasis formation.

Molecular Changes in Breast Cancer Induced by Radiation Therapy

PURPOSE

Breast cancer treatments are based on prognostic clinicopathologic features that form the basis for therapeutic guidelines. Although the utilization of these guidelines has decreased breast cancer-associated mortality rates over the past three decades, they are not adequate for individualized therapy. Radiation therapy (RT) is the backbone of breast cancer treatment. Although a highly successful therapeutic modality clinically, from a biological perspective, preclinical studies have shown RT to have the potential to alter tumor cell phenotype, immunogenicity, and the surrounding microenvironment, potentially changing the behavior of cancer cells and resulting in a significant variation in RT response. This review presents the recent advances in revealing the complex molecular changes induced by RT in the treatment of breast cancer and highlights the complexities of translating this information into clinically relevant tools for improved prognostic insights and the revelation of novel approaches for optimizing RT.

METHODS AND MATERIALS

Current literature was reviewed with a focus on recent advances made in the elucidation of tumor-associated radiation-induced molecular changes across molecular, genetic, and proteomic bases. This review was structured with the aim of providing an up-to-date overview over the very broad and complex subject matter of radiation-induced molecular changes and radioresistance, familiarizing the reader with the broader issue at hand.

RESULTS

The subject of radiation-induced molecular changes in breast cancer has been broached from various physiological focal points including that of the immune system, immunogenicity and the abscopal effect, tumor hypoxia, breast cancer classification and subtyping, molecular heterogeneity, and molecular plasticity. It is becoming increasingly apparent that breast cancer clinical subtyping alone does not adequately account for variation in RT response or radioresistance. Multiple components of the tumor microenvironment and immune system, delivered RT dose and fractionation schedules, radiation-induced bystander effects, and intrinsic tumor physiology and heterogeneity all contribute to the resultant RT outcome.

CONCLUSIONS

Despite recent advances and improvements in anticancer therapies, tumor resistance remains a significant challenge. As new analytical techniques and technologies continue to provide crucial insight into the complex molecular mechanisms of breast cancer and its treatment responses, it is becoming more evident that personalized anticancer treatment regimens may be vital in overcoming radioresistance.

Immune checkpoint inhibitors: Utilizing patient's own immunity to treat oral cancer

Head and Neck squamous cell carcinoma is an immunosuppressive state. HNSCC evades immune responses through multiple resistance mechanisms. Because of better understanding of interaction between tumour microenvironment and immune regulators, there is increasing interest in role of immunotherapy as a treatment modality of HNSCC. Many clinical trials have been performed using checkpoint inhibitors, as monotherapies and combination therapies. Immune checkpoint molecule, programmed cell death 1 (PD-1) has shown promising results as a treatment of Recurrent and Metastatic HNSCC. This review discusses immune checkpoint molecules, their functional mechanisms, role of immunotherapy as a monotherapies and combination therapy for better treatment and prognosis of HNSCC patients.

Results of an Integrated Phase I/II Prospective Clinical Trial (NEXIS) for Neoadjuvant Anti-PD-L1 (Durvalumab) and Anti-CTLA-4 (Tremelimumab) With Radiation for High-Risk Soft-Tissue Sarcoma of the Trunk and Extremities

Background The current management of large, high-grade soft tissue sarcoma (STS) of the trunk and extremities includes radiation and surgical resection. The initial use of chemotherapy and targeted therapy are controversial and although most patients present with localized disease, many eventually develop incurable metastases. The results and analysis of the safety and antitumor activity of combined checkpoint inhibitor immunotherapy with neoadjuvant radiation for high-risk primary STS are presented here. Methods This was an integrated phase I/II prospective single-arm trial (Nutrition and Exercise in Critical Illness Trial (NEXIS) trial). Eligible patients were age ≥18 years with histologically confirmed intermediate or high-grade STS of the trunk or extremity ≥5 cm diameter and were Eastern Cooperative Oncology Group performance status 0-1. The treatment algorithm included neoadjuvant anti-PD-L1 (Durvalumab) and anti-CTLA-4 (Tremelimumab) for three cycles of four weeks/cycle along with external beam radiation for five weeks, followed by wide surgical resection, and adjuvant Durvalumab monotherapy for four cycles. High-grade toxicity was continually assessed for the first 12 patients in phase I and the primary endpoint for phase II was an excellent histological response (grade 0 or 1 score on a semi-quantitative assessment for tumor regression). This study was registered with ClinicalTrials.gov, number NCT03116529. Findings Between October 2017 and November 2021, 23 patients were enrolled. Five patients had progression of distant disease during neoadjuvant treatment and withdrew from the study before surgery. A total of 18 patients who completed at least the neoadjuvant immunotherapy, radiation and surgery were included for analysis. The most common tumor was undifferentiated pleomorphic sarcoma (n=9, 50%). The occurrence of any adverse event (AE) was recorded in 16 (88.9%) patients, and 3 (16.7%) patients had a serious AE. Eight out of 18 patients (44.4%) had disease-free survival at a median of 39.7 months. Four out of 18 patients (22.2%) were alive-with-disease at a median of 37.1 months from diagnosis of distant metastasis, and six out of 18 (33.3%) died of disease at a median of 20.8 months from diagnosis of distant metastasis. Local recurrence occurred in two patients (11.1%) and was concomitant with distant disease in each case. Based on Response Evaluation Criteria in Solid Tumors v1.1, a partial response was noted in five (27.8%) cases, stable disease in 10 (55.6%) cases, and progressive disease in three (16.7%) cases. Histological semiquantitative analysis revealed a "good" response in eight (44.4%) patients, a "moderate" response in four (22.2%) patients, and a "poor" response in six (33.3%) patients. The mean patient-reported outcome measures regarding fatigue, physical function, or physical interference demonstrated no significant differences between various timepoints before, during, or after treatment. Conclusion Neoadjuvant combined immunotherapy and radiation for high-risk STS was relatively well-tolerated. The histological, radiologic, and clinical outcome data in this novel trial were relatively similar to historical literature for non-immunotherapy treatment regimens.

Tumor-Localized Interleukin-2 and Interleukin-12 Combine with Radiation Therapy to Safely Potentiate Regression of Advanced Malignant Melanoma in Pet Dogs

PURPOSE

Cytokines IL2 and IL12 exhibit potent anticancer activity but suffer a narrow therapeutic window due to off-tumor immune cell activation. Engineering cytokines with the ability to bind and associate with tumor collagen after intratumoral injection potentiated response without toxicity in mice and was previously safe in pet dogs with sarcoma. Here, we sought to test the efficacy of this approach in dogs with advanced melanoma.

PATIENTS AND METHODS

This study examined 15 client-owned dogs with histologically or cytologically confirmed malignant melanoma that received a single 9-Gy fraction of radiotherapy, followed by six cycles of combined collagen-anchored IL2 and IL12 therapy every 2 weeks. Cytokine dosing followed a 3 + 3 dose escalation design, with the initial cytokine dose chosen from prior evaluation in canine sarcomas. No exclusion criteria for tumor stage or metastatic burden, age, weight, or neuter status were applied for this trial.

RESULTS

Median survival regardless of the tumor stage or dose level was 256 days, and 10/13 (76.9%) dogs that completed treatment had CT-measured tumor regression at the treated lesion. In dogs with metastatic disease, 8/13 (61.5%) had partial responses across their combined lesions, which is evidence of locoregional response. Profiling by NanoString of treatment-resistant dogs revealed that B2m loss was predictive of poor response to this therapy.

CONCLUSIONS

Collectively, these results confirm the ability of locally administered tumor-anchored cytokines to potentiate responses at regional disease sites when combined with radiation. This evidence supports the clinical translation of this approach and highlights the utility of comparative investigation in canine cancers.

Immunological signatures from irradiated cancer-associated fibroblasts

Introduction

Cancer-associated fibroblasts (CAFs) are abundant and influential elements of the tumor microenvironment (TME), giving support to tumor development in multiple ways. Among other mechanisms, CAFs are important regulators of immunological processes occurring in tumors. However, CAF-mediated tumor immunomodulation in the context of radiotherapy remains poorly understood. In this study, we explore effects of radiation on CAF-derived immunoregulatory signals to the TME.

Methods

Primary CAF cultures were established from freshly collected human NSCLC lung tumors. CAFs were exposed to single-high or fractionated radiation regimens (1x18Gy or 3x6Gy), and the expression of different immunoregulatory cell-associated and secreted signaling molecules was analyzed 48h and 6 days after initiation of treatment. Analyses included quantitative measurements of released damage-associated molecular patterns (DAMPs), interferon (IFN) type I responses, expression of immune regulatory receptors, and secretion of soluble cytokines, chemokines, and growth factors. CAFs are able to survive ablative radiation regimens, however they enter into a stage of premature cell senescence.

Results

Our data show that CAFs avoid apoptosis and do not contribute by release of DAMPs or IFN-I secretion to radiation-mediated tumor immunoregulation. Furthermore, the secretion of relevant immunoregulatory cytokines and growth factors including TGF-β, IL-6, IL-10, TNFα, IL-1β, VEGF, CXCL12, and CXCL10 remain comparable between non-irradiated and radiation-induced senescent CAFs. Importantly, radiation exposure modifies the cell surface expression of some key immunoregulatory receptors, including upregulation of CD73 and CD276.

Discussion

Our data suggest that CAFs do not participate in the release of danger signals or IFN-I secretion following radiotherapy. The immune phenotype of CAFs and radiation-induced senescent CAFs is similar, however, the observed elevation of some cell surface immunological receptors on irradiated CAFs could contribute to the establishment of an enhanced immunosuppressive TME after radiotherapy.

The Effects of Gynecological Tumor Irradiation on the Immune System

Radiobiology has evolved from a mechanistic model based on DNA damage and response factors into a more complex model that includes effects on the immune system and the tumor microenvironment (TME). Irradiation has an immunomodulatory effect that can manifest as increased anti-tumor immunity or immunosuppression. Irradiation promotes an inflammatory microenvironment through the release of pro-inflammatory cytokines and endothelial damage, which recruit immune system cells to the irradiated area. Radiation-induced immunogenic cell death (ICD), characterized by the release of damage-associated molecular patterns (DAMPs) and tumor antigens, triggers an anti-tumor immune response of both innate and adaptive immunity. Anti-tumor immunity can manifest at a distance from the irradiated area, a phenomenon known as the abscopal effect (AE), which involves dendritic cells and CD8+ T cells. Irradiation also produces an immunosuppressive effect mediated by tumor-associated macrophages (TAMs) and regulatory T lymphocytes (Tregs), which counterbalances the immunostimulatory effect. In this work, we review the mechanisms involved in the radiation-induced immune response, which support the combined treatment of RT and immunotherapy, focusing, where possible, on gynecologic cancer.

Effects of clinically relevant radionuclides on the activation of a type I interferon response by radiopharmaceuticals in syngeneic murine tumor models

Radiopharmaceutical therapies (RPT) activate a type I interferon (IFN1) response in tumor cells. We hypothesized that the timing and amplitude of this response varies by isotope. We compared equal doses delivered by 90 Y, 177 Lu, and 225 Ac in vitro as unbound radionuclides and in vivo when chelated to NM600, a tumor-selective alkylphosphocholine. Response in murine MOC2 head and neck carcinoma and B78 melanoma was evaluated by qPCR and flow cytometry. Therapeutic response to 225 Ac-NM600+anti-CTLA4+anti-PD-L1 immune checkpoint inhibition (ICI) was evaluated in wild-type and stimulator of interferon genes knockout (STING KO) B78. The timing and magnitude of IFN1 response correlated with radionuclide half-life and linear energy transfer. CD8 + /Treg ratios increased in tumors 7 days after 90 Y- and 177 Lu-NM600 and day 21 after 225 Ac-NM600. 225 Ac-NM600+ICI improved survival in mice with WT but not with STING KO tumors, relative to monotherapies. Immunomodulatory effects of RPT vary with radioisotope and promote STING-dependent enhanced response to ICIs in murine models.

Teaser

This study describes the time course and nature of tumor immunomodulation by radiopharmaceuticals with differing physical properties.

Antibody targeting of anaerobic bacteria warms cold tumors and improves the abscopal effect of radiotherapy

BACKGROUND

The combination of immune checkpoint inhibitors with radiotherapy can enhance the immunomodulation by RT and reduce the growth of distant unirradiated tumors (abscopal effect); however, the results are still not very satisfactory. Therefore, new treatment options are needed to enhance this effect. Our previous study showed that the combination of Bifidobacterium (Bi) and its specific monoclonal antibody (mAb) could target and alleviate hypoxia at the tumor site and act as a radiosensitizer. In this study, we explored the anti-tumor efficacy of quadruple therapy (Bi + mAb and RT + αPD-1). The current study also aimed to probe into the complex immune mechanisms underlying this phenomenon.

METHODS

Constructed 4T1 breast and CT26 colon cancer tumor models. A comprehensive picture of the impact of constructed quadruple therapy was provided by tumor volume measurements, survival analysis, PET/CT imaging, immune cell infiltration analysis and cytokine expression levels.

RESULTS

The abscopal effect was further amplified in the "cold" tumor model and prolonged survival in tumor-bearing mice. Bi can colonized in primary and secondary tumors and direct the mAb to reach the tumor site, activate complement, enhance the ADCC effect and initiate the innate immune response. Then combined with αPD-1 and radiotherapy to stimulate adaptive immune response and synergize with cytokines to expand the immune efficacy and generate effective anti-tumor immune response.

CONCLUSIONS

Bi was used as an artificially implanted anaerobic target to cause a transient "infection" at the tumor, causing the tumor to become locally inflamed and "hot", and at the same time, mAb was used to target Bi to enhance the local immune effect of the tumor, and then combined with radiotherapy and αPD-1 to amplify the abscopal effect in multiple dimensions. Therefore, the present study provided a new idea for the multipotent immune-activating function of antibody-targeted anaerobic bacteria for the RT treatment of extensively metastasized cancer patients.

CTLA-4 silencing could promote anti-tumor effects in hepatocellular

Preclinical and clinical research showed that immune checkpoint blockade provides beneficial effects for many patients with liver cancer. This study aimed to assess the effect of CTLA-4-specific siRNA on the proliferation, cell cycle, migration, and apoptosis of HePG2 cells. Transfection of siRNA was performed by electroporation. The viability of cells was determined through MTT assay. Flow cytometry was performed to investigate the cell cycle and apoptosis rate, and the wound-healing assay was used to determine HepG2 cells migration. The expression levels of CTLA-4, c-Myc, Ki-67, BCL-2, BAX, caspase-9 (CAS9), and MMP-2,9,13 were measured by qRT-PCR. Transfection of specific CTLA-4-siRNA significantly inhibited the expression of the CTLA-4 gene. Also, our results revealed that CTLA-4 silencing diminished the proliferation and migration as well as induced the apoptosis of HePG2 cells. CTLA-4-siRNA transfection induced the cell cycle arrest in G2 phase. Moreover, CTLA-4-siRNA transfection reduced the expression levels of c-Myc, Ki-67, BCL-2, MMP-2,9,13, and elevated the expression levels of BAX and caspase-9. Our results suggest that silencing CTLA-4 through specific siRNA may be a promising strategy for future therapeutic interventions for treating liver cancer.

Beyond success: unveiling the hidden potential of radiotherapy and immunotherapy in solid tumors

Immunotherapy, particularly with immune checkpoint inhibitors, has significantly transformed cancer treatment. Despite its success, many patients struggle to respond adequately or sustain long-lasting clinical improvement. A growing consensus has emerged that radiotherapy (RT) enhances the response rate and overall efficacy of immunotherapy. Although combining RT and immunotherapy has been extensively investigated in preclinical models and has shown promising results, establishing itself as a dynamic and thriving area of research, clinical evidence for this combination strategy over the past five years has shown both positive and disappointing results, suggesting the need for a more nuanced understanding. This review provides a balanced and updated analysis of the combination of immunotherapy and RT. We summarized the preclinical mechanisms through which RT boosts antitumor immune responses and mainly focused on the outcomes of recently updated clinical trials, including those that may not have met expectations. We investigated the optimization of the therapeutic potential of this combined strategy, including key challenges, such as fractionation and scheduling, lymph node irradiation, and toxicity. Finally, we offered insights into the prospects and challenges associated with the clinical translation of this combination therapy, providing a realistic perspective on the current state of research and potential future directions.

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Treatment strategies and molecular mechanism of radiotherapy combined with immunotherapy in colorectal cancer

Radiotherapy (RT) remodels the tumor immune microenvironment (TIME) and modulates the immune response to indirectly destroy tumor cells, in addition to directly killing tumor cells. RT combined with immunotherapy may significantly enhance the efficacy of RT in colorectal cancer by modulating the microenvironment. However, the molecular mechanisms by which RT acts as an immunomodulator to modulate the immune microenvironment remain unclear. Further, the optimal modalities of RT combined with immunotherapy for the treatment of colorectal cancer, such as the time point of combining RT and immunization, the fractionation pattern and dosage of radiotherapy, and other methods to improve the efficacy, are also being explored parallelly. To address these aspects, in this review, we summarized the mechanisms by which RT modulates TIME and concluded the progress of RT combined with immunization in preclinical and clinical trials. Finally, we discussed heavy ion radiation therapy and the efficacy of prediction markers and other immune combination therapies. Overall, combining RT with immunotherapy to enhance antitumor effects will have a significant clinical implication and will help to facilitate individualized treatment modalities.

Mathematical modeling of the synergistic interplay of radiotherapy and immunotherapy in anti-cancer treatments

Introduction

While radiotherapy has long been recognized for its ability to directly ablate cancer cells through necrosis or apoptosis, radiotherapy-induced abscopal effect suggests that its impact extends beyond local tumor destruction thanks to immune response. Cellular proliferation and necrosis have been extensively studied using mathematical models that simulate tumor growth, such as Gompertz law, and the radiation effects, such as the linear-quadratic model. However, the effectiveness of radiotherapy-induced immune responses may vary among patients due to individual differences in radiation sensitivity and other factors.

Methods

We present a novel macroscopic approach designed to quantitatively analyze the intricate dynamics governing the interactions among the immune system, radiotherapy, and tumor progression. Building upon previous research demonstrating the synergistic effects of radiotherapy and immunotherapy in cancer treatment, we provide a comprehensive mathematical framework for understanding the underlying mechanisms driving these interactions.

Results

Our method leverages macroscopic observations and mathematical modeling to capture the overarching dynamics of this interplay, offering valuable insights for optimizing cancer treatment strategies. One shows that Gompertz law can describe therapy effects with two effective parameters. This result permits quantitative data analyses, which give useful indications for the disease progression and clinical decisions.

Discussion

Through validation against diverse data sets from the literature, we demonstrate the reliability and versatility of our approach in predicting the time evolution of the disease and assessing the potential efficacy of radiotherapy-immunotherapy combinations. This further supports the promising potential of the abscopal effect, suggesting that in select cases, depending on tumor size, it may confer full efficacy to radiotherapy.

Nanomedicine for T-Cell Mediated Immunotherapy

T-cell immunotherapy offers outstanding advantages in the treatment of various diseases, and with the selection of appropriate targets, efficient disease treatment can be achieved. T-cell immunotherapy has made great progress, but clinical results show that only a small proportion of patients can benefit from T-cell immunotherapy. The extensive mechanistic work outlines a blueprint for using T cells as a new option for immunotherapy, but also presents new challenges, including the balance between different fractions of T cells, the inherent T-cell suppression patterns in the disease microenvironment, the acquired loss of targets, and the decline of T-cell viability. The diversity, flexibility, and intelligence of nanomedicines give them great potential for enhancing T-cell immunotherapy. Here, how T-cell immunotherapy strategies can be adapted with different nanomaterials to enhance therapeutic efficacy is discussed. For two different pathological states, immunosuppression and immune activation, recent advances in nanomedicines for T-cell immunotherapy in diseases such as cancers, rheumatoid arthritis, systemic lupus erythematosus, ulcerative colitis, and diabetes are summarized. With a focus on T-cell immunotherapy, this review highlights the outstanding advantages of nanomedicines in disease treatment, and helps advance one's understanding of the use of nanotechnology to enhance T-cell immunotherapy.

Neoadjuvant radiotherapy in ER+, HER2+, and triple-negative -specific breast cancer based humanized tumor mice enhances anti-PD-L1 treatment efficacy

Pre-operative radiation therapy is not currently integrated into the treatment protocols for breast cancer. However, transforming immunological "cold" breast cancers by neoadjuvant irradiation into their "hot" variants is supposed to elicit an endogenous tumor immune defense and, thus, enhance immunotherapy efficiency. We investigated cellular and immunological effects of sub-lethal, neoadjuvant irradiation of ER pos., HER2 pos., and triple-negative breast cancer subtypes in-vitro and in-vivo in humanized tumor mice (HTM). This mouse model is characterized by a human-like immune system and therefore facilitates detailed analysis of the mechanisms and efficiency of neoadjuvant, irradiation-induced "in-situ vaccination", especially in the context of concurrently applied checkpoint therapy. Similar to clinical appearances, we observed a gradually increased immunogenicity from the luminal over the HER2-pos. to the triple negative subtype in HTM indicated by an increasing immune cell infiltration into the tumor tissue. Anti-PD-L1 therapy divided the HER2-pos. and triple negative HTM groups into responder and non-responder, while the luminal HTMs were basically irresponsive. Irradiation alone was effective in the HER2-pos. and luminal subtype-specific HTM and was supportive for overcoming irresponsiveness to single anti-PD-L1 treatment. The treatment success correlated with a significantly increased T cell proportion and PD-1 expression in the spleen. In all subtype-specific HTM combination therapy proved most effective in diminishing tumor growth, enhancing the immune response, and converted non-responder into responder during anti-PD-L1 therapy. In HTM, neoadjuvant irradiation reinforced anti-PD-L1 checkpoint treatment of breast cancer in a subtype -specific manner. According to the "bench to bedside" principle, this study offers a vital foundation for clinical translating the use of neoadjuvant irradiation in the context of checkpoint therapy.

The interplay between autophagy and cGAS-STING signaling and its implications for cancer

Autophagy is an intracellular process that targets various cargos for degradation, including members of the cGAS-STING signaling cascade. cGAS-STING senses cytosolic double-stranded DNA and triggers an innate immune response through type I interferons. Emerging evidence suggests that autophagy plays a crucial role in regulating and fine-tuning cGAS-STING signaling. Reciprocally, cGAS-STING pathway members can actively induce canonical as well as various non-canonical forms of autophagy, establishing a regulatory network of feedback mechanisms that alter both the cGAS-STING and the autophagic pathway. The crosstalk between autophagy and the cGAS-STING pathway impacts a wide variety of cellular processes such as protection against pathogenic infections as well as signaling in neurodegenerative disease, autoinflammatory disease and cancer. Here we provide a comprehensive overview of the mechanisms involved in autophagy and cGAS-STING signaling, with a specific focus on the interactions between the two pathways and their importance for cancer.

Killing two birds with one stone: Abscopal effect mechanism and its application prospect in radiotherapy

Abscopal effects are characterized by the emergence of neoplasms in regions unrelated to the primary radiation therapy site, displaying a gradual attenuation or regression throughout the progression of radiation therapy, which have been of interest to scientists since Mole's proposal in 1953. The incidence of abscopal effects in radiation therapy is intricately linked to the immune system, with both innate and adaptive immune responses playing crucial roles. Biological factors impacting abscopal effects ultimately exert their influence on the intricate workings of the immune system. Although abscopal effects are rarely observed in clinical cases, the underlying mechanism remains uncertain. This article examines the biological and physical factors influencing abscopal effects of radiotherapy. Through a review of preclinical and clinical studies, this article aims to offer a comprehensive understanding of abscopal effects and proposes new avenues for future research in this field. The findings presented in this article serve as a valuable reference for researchers seeking to explore this topic in greater depth.

Combinatorial approach of immuno-proton therapy in cancer: Rationale and potential impact

Cancer management is an expansive, growing, and evolving field. In the last decade or so, immunotherapy (IT) and particle beam therapy have made a tremendous impact in this domain. IT has already established itself as the fourth pillar of oncology. Recent emphasis has been centred around combination therapy, postulating additive or multiplicative effects of combining IT with one or more of the three conventional "pillars," that is, surgery, chemotherapy, and radiotherapy. Radio-IT is being increasingly explored and has shown promising outcomes in both preclinical and clinical settings. Particle beam therapy such as protons, when used as the radiotherapeutic modality in conjunction with IT, can potentially limit toxicities and improve this synergism further. Modern proton therapy has demonstrated a reduction in integral dose of radiation and radiation-induced lymphopenia in various sites. Protons, by virtue of their inherent clinically desirable physical and biological characteristics, namely, high linear energy transfer, relative biological effectiveness of range 1.1-1.6, and proven anti-metastatic and immunogenic potential in preclinical studies, might have a superior immunogenic profile than photons. Proton-IT combination is being studied currently by various groups in lung , head neck and brain tumors, and should be evaluated further in other subsites to replicate preclinical outcomes in a clinical setting. In this review, we summarize the currently available evidence for combinatorial approaches and feasibility of proton and IT combination, and thereafter highlight the emerging challenges for practical application of the same in clinics, while also proposing plausible solutions.

Immunotherapy and Radiotherapy Combinations for Sarcoma

Sarcomas are a heterogeneous group of bone and soft tissue tumors. Survival outcomes for advanced (unresectable or metastatic) disease remain poor, so therapeutic improvements are needed. Radiotherapy plays an integral role in the neoadjuvant and adjuvant treatment of localized disease as well as in the treatment of metastatic disease. Combining radiotherapy with immunotherapy to potentiate immunotherapy has been used in a variety of cancers other than sarcoma, and there is opportunity to further investigate combining immunotherapy with radiotherapy to try to improve outcomes in sarcoma. In this review, we describe the diversity of the tumor immune microenvironments for sarcomas and describe the immunomodulatory effects of radiotherapy. We discuss studies on the timing of radiotherapy relative to immunotherapy and studies on the radiotherapy dose and fractionation regimen to be used in combination with immunotherapy. We describe the impact of radiotherapy on the tumor immune microenvironment. We review completed and ongoing clinical trials combining radiotherapy with immunotherapy for sarcoma and propose future directions for studies combining immunotherapy with radiotherapy in the treatment of sarcoma.

Carbon Ion Irradiation Activates Anti-Cancer Immunity

Carbon ion beams have the unique property of higher linear energy transfer, which causes clustered damage of DNA, impacting the cell repair system. This sometimes triggers apoptosis and the release in the cytoplasm of damaged DNA, leading to type I interferon (IFN) secretion via the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes pathway. Dendritic cells phagocytize dead cancer cells and damaged DNA derived from injured cancer cells, which together activate dendritic cells to present cancer-derived antigens to antigen-specific T cells in the lymph nodes. Thus, carbon ion radiation therapy (CIRT) activates anti-cancer immunity. However, cancer is protected by the tumor microenvironment (TME), which consists of pro-cancerous immune cells, such as regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. The TME is too robust to be destroyed by the CIRT-mediated anti-cancer immunity. Various modalities targeting regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages have been developed. Preclinical studies have shown that CIRT-mediated anti-cancer immunity exerts its effects in the presence of these modalities. In this review article, we provide an overview of CIRT-mediated anti-cancer immunity, with a particular focus on recently identified means of targeting the TME.

Tumor-localized interleukin-2 and interleukin-12 combine with radiation therapy to safely potentiate regression of advanced malignant melanoma in pet dogs

The clinical use of interleukin-2 and -12 cytokines against cancer is limited by their narrow therapeutic windows due to on-target, off-tumor activation of immune cells when delivered systemically. Engineering IL-2 and IL-12 to bind to extracellular matrix collagen allows these cytokines to be retained within tumors after intralesional injection, overcoming these clinical safety challenges. While this approach has potentiated responses in syngeneic mouse tumors without toxicity, the complex tumor-immune interactions in human cancers are difficult to recapitulate in mouse models of cancer. This has driven an increased role for comparative oncology clinical trials in companion (pet) dogs with spontaneous cancers that feature analogous tumor and immune biology to human cancers. Here, we report the results from a dose-escalation clinical trial of intratumoral collagen-binding IL-2 and IL-12 cytokines in pet dogs with malignant melanoma, observing encouraging local and regional responses to therapy that may suggest human clinical benefit with this approach.

Tumor Microenvironment-Responsive Nanoparticles Amplifying STING Signaling Pathway for Cancer Immunotherapy

Insufficient activation of the stimulator of interferon genes (STING) signaling pathway and profoundly immunosuppressive microenvironment largely limits the effect of cancer immunotherapy. Herein, tumor microenvironment (TME)-responsive nanoparticles (PMM NPs) are exploited that simultaneously harness STING and Toll-like receptor 4 (TLR4) to augment STING activation via TLR4-mediated nuclear factor-kappa B signaling pathway stimulation, leading to the increased secretion of type I interferons (i.e., 4.0-fold enhancement of IFN-β) and pro-inflammatory cytokines to promote a specific T cell immune response. Moreover, PMM NPs relieve the immunosuppression of the TME by decreasing the percentage of regulatory T cells, and polarizing M2 macrophages to the M1 type, thus creating an immune-supportive TME to unleash a cascade adaptive immune response. Combined with an anti-PD-1 antibody, synergistic efficacy is achieved in both inflamed colorectal cancer and noninflamed metastatic breast tumor models. Moreover, rechallenging tumor-free animals with homotypic cells induced complete tumor rejection, indicating the generation of systemic antitumor memory. These TME-responsive nanoparticles may open a new avenue to achieve the spatiotemporal orchestration of STING activation, providing a promising clinical candidate for next-generation cancer immunotherapy.

A new target of radiotherapy combined with immunotherapy: regulatory T cells

Radiotherapy is one important treatment for malignant tumours. It is widely believed today that radiotherapy has not only been used as a local tumour treatment method, but also can induce systemic anti-tumour responses by influencing the tumour microenvironment, but its efficacy is limited by the tumour immunosuppression microenvironment. With the advancement of technology, immunotherapy has entered a golden age of rapid development, gradually occupying a place in clinical tumour treatment. Regulatory T cells (Tregs) widely distributing in the tumour microenvironment play an important role in mediating tumour development. This article analyzes immunotherapy, the interaction between Tregs, tumours and radiotherapy. It briefly introduces immunotherapies targeting Tregs, aiming to provide new strategies for radiotherapy combined with Immunotherapy.