Overcoming on-target, off-tumour toxicity of CAR T cell therapy for solid tumours

Engineering TCR-controlled fuzzy logic into CAR T cells enhances therapeutic specificity

Chimeric antigen receptor (CAR) T cell immunotherapy represents a breakthrough in the treatment of hematological malignancies, but poor specificity has limited its applicability to solid tumors. By contrast, natural T cells harboring T cell receptors (TCRs) can discriminate between neoantigen-expressing cancer cells and self-antigen-expressing healthy tissues but have limited potency against tumors. We used a high-throughput platform to systematically evaluate the impact of co-expressing a TCR and CAR on the same CAR T cell. While strong TCR-antigen interactions enhanced CAR activation, weak TCR-antigen interactions actively antagonized their activation. Mathematical modeling captured this TCR-CAR crosstalk in CAR T cells, allowing us to engineer dual TCR/CAR T cells targeting neoantigens (HHATL8F/p53R175H) and human epithelial growth factor receptor 2 (HER2) ligands, respectively. These T cells exhibited superior anti-cancer activity and minimal toxicity against healthy tissue compared with conventional CAR T cells in a humanized solid tumor mouse model. Harnessing pre-existing inhibitory crosstalk between receptors, therefore, paves the way for the design of more precise cancer immunotherapies.

Unravelling the modified T cell receptor through Gen-Next CAR T cell therapy in Glioblastoma: Current status and future challenges

PURPOSE

Despite current technological advancements in the treatment of glioma, immediate alleviation of symptoms can be catered by therapeutic modalities, including surgery, chemotherapy, and combinatorial radiotherapy that exploit aberrations of glioma. Additionally, a small number of target antigens, their heterogeneity, and immune evasion are the potential reasons for developing targeted therapies. This oncologic milestone has catalyzed interest in developing immunotherapies against Glioblastoma to improve overall survival and cure patients with high-grade glioma. The next-gen CAR-T Cell therapy is one of the effective immunotherapeutic strategies in which autologous T cells have been modified to express receptors against GBM and it modulates cytotoxicity.

METHODS

In this review article, we examine preclinical and clinical outcomes, and limitations as well as present cutting-edge techniques to improve the function of CAR-T cell therapy and explore the possibility of combination therapy.

FINDINGS

To date, several CAR T-cell therapies are being evaluated in clinical trials for GBM and other brain malignancies and multiple preclinical studies have demonstrated encouraging outcomes.

IMPLICATIONS

CAR-T cell therapy represents a promising therapeutic paradigm in the treatment of solid tumors but a few limitations include, the blood-brain barrier (BBB), antigen escape, tumor microenvironment (TME), tumor heterogeneity, and its plasticity that suppresses immune responses weakens the ability of this therapy. Additional investigation is required that can accurately identify the targets and reflect the similar architecture of glioblastoma, thus optimizing the efficiency of CAR-T cell therapy; allowing for the selection of patients most likely to benefit from immuno-based treatments.

CAR T cells in lung cancer: Targeting tumor-associated antigens to revolutionize immunotherapy

Tumor-targeted T cells engineered for targeting and killing tumor cells have revolutionized cancer treatment, specifically in hematologic malignancies, through chimeric antigen receptor (CAR) T cell therapy. However, the migration of this success to lung cancer is challenging due to the tumor microenvironment (TME), antigen heterogeneity, and limitations of T cell infiltration. This review aims to evaluate current strategies addressing these barriers, focusing on the optimization of tumor-associated antigen (TAA) targeting, such as epidermal growth factor receptor (EGFR), mucin-1 (MUC1), and mesothelin (MSLN), which are frequently overexpressed in lung cancer and offer promising targets for CAR T-cell therapy. In this review, we discuss recent progress in CAR T cell engineering, applying enhanced costimulatory molecules, cytokine-secreting CAR T cells, and engineered modifications to improve T cell resilience in immunosuppressive environments. Additionally, this review also evaluates combination therapies of immune checkpoint inhibitors and recently published clinical trials on lung cancer with CAR T cells. We offer insights into the way to optimize CAR T cell therapy for lung cancer by analyzing antigen selection, immune evasion, and the strategies to enhance T cell persistence and tumor infiltration.

Amplifying the Antitumor Effect of STING Agonist MSA-2 by Phospholipid Nanoparticles Delivering STING mRNA and Copper-Modified MSA-2 Combination

STING activation is a promising application therapeutic strategy for cancer immunotherapy. In particular, MSA-2 as an oral STING agonist is discovered to have antitumor activity. However, how to improve the antitumor effect of MSA-2 is a very valuable contribution to cancer immunotherapy. Here, we use two strategies to amplify the antitumor effect of MSA-2 by phospholipid nanoparticles delivering STING mRNA and copper-modified MSA-2. We synthesized a new series of ionizable phospholipid nanoparticles and optimized a phospholipid nanoparticle (1AP24) for delivering STING mRNA, increasing the expression of STING protein to bind more MSA-2. Second, we synthesized copper-modified MSA-2 (MSA-2-Cu), which induced cell death by Cu2+ toxicity. Combining 1AP24@STING mRNA and MSA-2-Cu can crucially decrease tumor growth and increase a mouse's survival. It is a new treatment strategy through amplifying the STING pathway.

Revolutionizing Immunotherapy: The Next Frontier in CAR T-Cell Engineering

Chimeric Antigen Receptor (CAR) T-cell therapy has emerged as a groundbreaking immunotherapy, offering new hope for cancer treatment, particularly in hematologic malignancies. This review explores the development of CAR T-cell therapy from its first-generation design, which laid the foundational structure, to advanced fifth-generation CARs that integrate sophisticated synthetic biology. Each generation of CARs has introduced critical improvements, such as the incorporation of costimulatory domains, dual signaling pathways, and cytokine release mechanisms to enhance T-cell activation, persistence, and efficacy. Current applications of CAR T-cell therapy have seen significant success in treating cancers like acute lymphoblastic leukemia and diffuse large B-cell lymphoma, with several therapies gaining regulatory approval. However, challenges persist in targeting solid tumors due to the immunosuppressive tumor microenvironment and antigen heterogeneity. Ongoing clinical trials and research are focused on overcoming these barriers through next-generation CAR designs, novel antigen targets, and combination therapies. The review highlights recent advancements, emerging targets, and the potential of CAR T-cell therapy to revolutionize cancer treatment, paving the way for more effective and personalized approaches.

Role of NK Cells in Progression and Treatment of Multiple Myeloma

Multiple myeloma (MM) is a haematological malignancy originating from terminally differentiated B cells, resulting in significant morbidity and mortality. Currently, MM is regarded as an incurable disease, often exhibiting a relapse-remitting pattern that necessitates multiple lines of therapy. It is now well-established that ineffective immunosurveillance plays a critical role in the progression of MM. Consequently, strategies that redirect immune effector cells against MM have emerged as effective treatment modalities, particularly in cases where standard care therapies fail. T cell-based immunotherapy has gained considerable attention in ongoing clinical trials; however, natural killer (NK) cells, known for their ability to execute cytotoxicity against infected and malignant cells with precision, may offer complementary therapeutic advantages over T cells and possess untapped therapeutic potential. This review seeks to introduce readers to the significance of NK cell-mediated immunosurveillance in the context of MM, explore the potential benefits of redirecting NK cells against MM, and illustrate how current treatment strategies are often reliant on the functionality of NK cells. Most importantly, new promising mechanisms of harnessing NK cell-based immunity against MM are reviewed and put into a clinical perspective to highlight their implications for patient treatment and outcomes.

CAR T cell therapies in gastrointestinal cancers: current clinical trials and strategies to overcome challenges

Despite multimodal treatment options, most gastrointestinal cancers are still associated with high mortality rates and poor responsiveness to immunotherapy. The unprecedented efficacy of chimeric antigen receptor (CAR)-engineered T cells in the treatment of haematological malignancies raised interest in translating CAR T cell therapies to the treatment of gastrointestinal cancers. Treatment of solid cancers with canonical CAR T cells faces substantial challenges, including the dense architecture of the tumour tissue, the tolerogenic environment with low tumour-intrinsic immunogenicity, the rareness of targetable tumour-selective antigens, the antigenic heterogeneity of cancer cells, and the profound metabolic and immune cell disbalances. This Review provides an overview of CAR T cell trials in the treatment of gastrointestinal cancers, discussing considerations relating to safety, efficacy, potential reasons for failure and options for improving CAR T cells for the future. In addition, lessons regarding how to improve efficacy are drawn from CAR T cells armed with adjuvants that sustain their activation within the hostile environment and activate resident immune cells. As the field is rapidly evolving, current treatment modalities and editing CAR T cell functionalities are being refined towards a potentially more successful CAR T cell therapy for gastrointestinal cancers.

CAR-T therapy in solid tumors

While chimeric antigen receptor (CAR) T cell therapy has shown great success in hematologic malignancies, the effectiveness in solid tumors has been limited by several factors, including antigenic heterogeneity and the immunosuppressive nature of the tumor microenvironment (TME). In this review, we discuss the advancements made in clinical studies and challenges faced by CAR-T therapy for solid tumors. To enhance CAR-T cell efficacy in solid tumors, we explore strategies such as enhancing T cell persistence and cytotoxicity, targeting multiple antigens, and utilizing innovative allogeneic CAR-T cell manufacturing. Additionally, we highlight the potential benefits of combining CAR-T therapies with immune checkpoint inhibitors and other treatment modalities to overcome TME limitations. We remain optimistic about the future of CAR-T cell therapy in solid tumors, emphasizing the need for continued research to refine therapeutic approaches and address the clinical needs of patients with cancer.

A Comprehensive Review About the Use of Monoclonal Antibodies in Cancer Therapy

Monoclonal antibodies (mAbs) targeting various pathways in cancer therapy play crucial roles in enhancing the immune system's ability to recognise and eliminate tumour cells. These therapies are designed to either block inhibitory immune checkpoint pathways or to target specific tumour cell markers for direct destruction. Additionally, mAbs can modulate the tumour microenvironment, enhance antibody-dependent cellular cytotoxicity, and inhibit angiogenesis, further amplifying their therapeutic impact. Below is a summary of monoclonal antibodies targeting key pathways, along with their indications and mechanisms of action, which are reviewed based on therapeutic mechanisms.

Current Trends in Messenger RNA Technology for Cancer Therapeutics

Messenger RNA (mRNA)-based therapy has revolutionized cancer research by enabling versatile delivery systems for therapeutic applications. The future of mRNA-based cancer therapies shows promise amidst challenges such as delivery efficiency, immunogenicity, and tumor heterogeneity. Recent progress has adapted various strategies such as design flexibility, scalable production, and targeted delivery capabilities to enhance the potential in personalized cancer therapy. Further research to optimize delivery for enhanced outcomes and efficacy in solid tumors is warranted. Therefore, we aim to explore the current landscape and future prospects of mRNA technology across various therapeutic platforms.

Multi-omic landscape of human gliomas from diagnosis to treatment and recurrence

Gliomas are among the most lethal cancers, with limited treatment options. To uncover hallmarks of therapeutic escape and tumor microenvironment (TME) evolution, we applied spatial proteomics, transcriptomics, and glycomics to 670 lesions from 310 adult and pediatric patients. Single-cell analysis shows high B7H3+ tumor cell prevalence in glioblastoma (GBM) and pleomorphic xanthoastrocytoma (PXA), while most gliomas, including pediatric cases, express targetable tumor antigens in less than 50% of tumor cells, potentially explaining trial failures. Longitudinal samples of isocitrate dehydrogenase (IDH)-mutant gliomas reveal recurrence driven by tumor-immune spatial reorganization, shifting from T-cell and vasculature-associated myeloid cell-enriched niches to microglia and CD206+ macrophage-dominated tumors. Multi-omic integration identified N-glycosylation as the best classifier of grade, while the immune transcriptome best predicted GBM survival. Provided as a community resource, this study opens new avenues for glioma targeting, classification, outcome prediction, and a baseline of TME composition across all stages.

Novel strategies in breast cancer management: From treatment to long-term remission

Breast cancer (BC) is the most common malignancy among women and a leading cause of cancer-related mortality worldwide. Although improvements in early detection and therapy have been made, metastatic breast cancer (mBC) continues to be an incurable disease. Although existing treatments can prolong survival and enhance quality of life, they do not provide a definitive cure. Targeted therapies have significantly improved outcomes, particularly for subtypes such as human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor (HR)-positive (HR+) BC. Key innovations include antibodydrug conjugates (ADCs) and next-generation endocrine therapies. ADCs combine monoclonal antibodies with cytotoxic agents, allowing targeted delivery to tumor cells while minimizing systemic toxicity. Immunotherapy is emerging as a promising approach for aggressive subtypes, such as triple-negative breast cancer (TNBC). Strategies under investigation include chimeric antigen receptor T-cell (CAR-T) therapy, tumor-infiltrating lymphocyte (TIL) therapies, and natural killer (NK) cell treatments, all aimed at enhancing the ability of the immune system to target and eliminate resistant tumor cells. Tissue engineering, particularly hydrogel-based delivery systems, offers the potential for localized treatment. These systems enable the controlled release of therapeutic agents or immune cells directly to the tumor site, supporting tissue regeneration and enhancing immune surveillance to reduce recurrence. Despite these advancements, challenges remain, including treatment resistance, the immunosuppressive tumor microenvironment, and high costs. Overcoming these barriers requires further innovation in drug delivery systems and a deeper understanding of tumor biology.

RESET: A TCR-coupled antigen receptor with superior targeting sensitivity and reversible drug-regulated anti-tumor activity

Chimeric antigen receptor (CAR) T cells are effective cancer therapies, particularly in indications with high, stable, and tumor-specific antigen expression. Other settings may require improved targeting sensitivity, controllable targeting selectivity, and/or additional potency enhancements to achieve robust efficacy. Here, we describe a novel receptor architecture called RESET (rapamycin-enabled, switchable endogenous T cell receptor) that combines (1) cell surface antigen targeting, (2) small-molecule regulation, and (3) the signaling proficiency and inherent sensitivity of native T cell receptors. RESET-T cells outperformed both constitutive and drug-regulated CAR-T cells and show hallmarks of TCR activation that suggest improved fidelity to native T cell responses. Pharmacological control then increases safety through toggling T cell activation between active and resting states and may mitigate T cell exhaustion caused by continuous antigen exposure. This convergence of drug-regulated targeting and natural immune receptor signal transduction may better replicate the kinetics and physiology of a classical T cell response and potentiate more successful and safer immunotherapies.

The Bidirectional Interplay between T Cell-Based Immunotherapies and the Tumor Microenvironment

T cell-based therapies, including tumor-infiltrating lymphocyte therapy, T-cell receptor-engineered T cells, and chimeric antigen receptor T cells, are powerful therapeutic approaches for cancer treatment. Whereas these therapies are primarily known for their direct cytotoxic effects on cancer cells, accumulating evidence indicates that they also influence the tumor microenvironment (TME) by altering the cytokine milieu and recruiting additional effector populations to help orchestrate the antitumor immune response. Conversely, the TME itself can modulate the behavior of these therapies within the host by either supporting or inhibiting their activity. In this review, we provide an overview of clinical and preclinical data on the bidirectional influences between T-cell therapies and the TME. Unraveling the interactions between T cell-based therapies and the TME is critical for a better understanding of their mechanisms of action, resistance, and toxicity, with the goal of optimizing efficacy and safety.

Precision epitope editing: A path to advanced immunotherapies

The ability to recognize antigen epitope is crucial for generating an effective immune response. By engineering these epitopes, researchers can reduce on-target/off-tumor toxicity associated with targeted immunotherapy. Recent studies indicate that employing various gene editing tools to modify the epitopes of healthy hematopoietic stem and progenitor cells (HSPCs) can protect these cells from toxicity during tumor eradication, all while preserving their differentiation and function. This advancement greatly enhances the safety and efficacy of tumor immunotherapy.

The Role of STEAP1 in Prostate Cancer: Implications for Diagnosis and Therapeutic Strategies

Prostate cancer (PCa) is one of the most common malignancies and the second leading cause of cancer-related death in men worldwide. The six-transmembrane epithelial antigen of the prostate 1 (STEAP1) is exceptionally overexpressed in PCa, maintaining high expression even in the castration-resistant prostate cancer (CRPC) stage, making it a promising target for diagnosis and treatment. STEAP1-positive extracellular vesicles and STEAP1-PET imaging are optimistic approaches for the non-invasive detection of different stages of PCa. STEAP1-targeted therapy includes an antibody-drug conjugate (ADC), chimeric antigen receptor T cell (CAR-T), T-cell engager (TCE), and vaccines, which demonstrate valuable therapeutic prospects. This review presents the structure and pathophysiological function of STEAP1, synthesizes cutting-edge advances in STEAP1-targeted molecular imaging and clinical applications, and critically analyzes their translational potential to overcome the limitations of current PCa diagnosis and treatment.

Potential target within the tumor microenvironment - MT1-MMP

Matrix metalloproteinases are integral to the modification of the tumor microenvironment and facilitate tumor progression by degrading the extracellular matrix, releasing cytokines, and influencing the recruitment of immune cells. Among the matrix metalloproteinases, membrane-type matrix metalloproteinase 1 (MT1-MMP/MMP14) is the first identified membrane-type MMP and acts as an essential proteolytic enzyme that enables tumor infiltration and metastatic progression. Given the pivotal role of MT1-MMP in tumor progression and the correlation between its overexpression in tumors and unfavorable prognoses across multiple cancer types, a comprehensive understanding of the potential functional mechanisms of MT1-MMP is essential. This knowledge will aid in the advancement of diverse anti-tumor therapies aimed at targeting MT1-MMP. Although contemporary research has highlighted the considerable potential of MT1-MMP in targeted cancer therapy, studies pertaining to its application in cell therapy remain relatively limited. In this review, we delineate the structural characteristics and regulatory mechanisms of MT1-MMP expression, as well as its biological significance in tumorigenesis. Finally, we discussed the current status and prospects of anti-tumor therapies targeting MT1-MMP.

Mitigation and Management of Common Toxicities Associated with the Administration of CAR-T Therapies in Oncology Patients

Chimeric antigen receptor T-cell (CAR-T) therapies are one of the main approaches among targeted cellular therapies. Despite the potential benefit and durable responses observed in some patients receiving CAR-T therapies, serious and potentially fatal toxicities remain a major challenge. The most common CAR-T-associated toxicities include cytokine release syndrome (CRS), neurotoxicity, cytopenias, and infections. While CRS and neurotoxicity are generally managed with tocilizumab and corticosteroids, respectively, high-grade toxicities can be life-threatening. Close postinfusion monitoring and assessment of clinical laboratory parameters, patient-related and clinical risk factors (e.g., age, tumor burden, comorbidities, baseline laboratory parameters, and underlying abnormalities), and therapy-related risk factors (e.g., CAR-T type, dose, and CAR-T-induced toxicity) are effective strategies to mitigate the toxicities. Clinical laboratory parameters, including various cytokines, have been identified for CRS (interleukin [IL]-1, IL-2, IL-5, IL-6, IL-8, IL-10, C-reactive protein [CRP], interferon [IFN]-γ, ferritin, granulocyte-macrophage colony-stimulating factor [GM-CSF], and monocyte chemoattractant protein-1), neurotoxicity (IL-1, IL-2, IL-6, IL-15, tumor necrosis factor [TNF]-α, GM-CSF, and IFN-γ), cytopenias (IL-2, IL-4, IL-6, IL-10, IFN-γ, ferritin, and CRP), and infections (IL-8, IL-1β, CRP, IFN-γ, and procalcitonin). CAR-T-associated toxicities can be monitored and treated to mitigate the risk to patients. Assessment of alterations in clinical laboratory parameter values that are correlated with CAR-T-associated toxicities may predict development and/or severity of a given toxicity, which can improve patient management strategies and ultimately enable the patients to better tolerate these therapies.

Sodium citrate pretreatment enhances CAR-T cell persistence and anti-tumor efficacy through inhibition of calcium signaling

Introduction

Chimeric antigen receptor T cell (CAR-T) therapy has shown success in treating hematological malignancies, but its effectiveness against solid tumors is hindered by T cell exhaustion. During in vitro expansion, tonic signaling induced by CAR expression contributes to CAR-T cell exhaustion, which can be mitigated by inhibiting calcium signaling. Given that sodium citrate can chelate calcium ions and inhibit calcium signaling, in this study, we investigated whether sodium citrate could reduce exhaustion and enhance CAR-T cell function.

Methods

We constructed anti-CD70 CAR-T cells and cultured them in the presence of sodium citrate. The characteristics and functionality of sodium citrate-pretreated CAR-T cells were assessed through in vitro and in vivo experiments. To further validate our observation, we also treated anti-mesothelin (MSLN) CAR-T cells with sodium citrate and detected the phenotypes and anti-tumor function of CAR-T cells.

Results

We found that sodium citrate-pretreated anti-CD70 CAR-T cells exhibited reduced exhaustion, increased memory T cell proportions, and enhanced anti-tumor efficacy both in vitro and in vivo. Notably, sodium citrate treatment improved the in vivo persistence of CAR-T cells and prevented tumor recurrence. These beneficial effects were also observed in anti-MSLN CAR-T cells. Transcriptomic and metabolite analyses revealed that sodium citrate inhibited calcium signaling, mTORC1 activity, and glycolysis pathways, thus modulating T cell exhaustion and differentiation.

Discussion

Our findings suggest that sodium citrate supplementation during CAR-T cell expansion could be a promising strategy to improve CAR-T therapy for solid tumors by preventing exhaustion and promoting memory T cell formation.

Metal ions and nanomaterials for targeted bone cancer immunotherapy

Bone cancer remains a significant challenge in oncology, with limited success in current therapeutic approaches, particularly immunotherapy. Emerging research highlights the potential of integrating metal ions and nanomaterials for targeted immunotherapy in bone cancer. Metal ions, including calcium, magnesium, and zinc, play a significant role in modulating immune responses within the tumor microenvironment, affecting essential pathways necessary for immune activation. Meanwhile, nanomaterials, particularly metallic nanoparticles, offer precise drug delivery and immune system modulation, improving the efficacy of immunotherapeutic agents. This review explores the synergistic effects of metal ion-nanomaterial conjugates, discussing their role in enhancing immune cell activation, particularly T-cells and macrophages, and their potential for controlled drug release. We highlight preclinical advancements in bone cancer treatment using metal ion-responsive nanoparticles, and address current challenges such as biocompatibility and toxicity. Finally, we discuss the future prospects of these technologies in personalized and precision medicine, aiming to revolutionize bone cancer immunotherapy.

Chimeric Antigen Receptor-T Cells in Colorectal Cancer: Pioneering New Avenues in Solid Tumor Immunotherapy

Colorectal cancer (CRC) remains a major global health burden, being one of the most prevalent cancers with high mortality rates. Despite advances in conventional treatment modalities, patients with metastatic CRC often face limited options and poor outcomes. Chimeric antigen receptor-T (CAR-T) cell therapy, initially successful in hematologic malignancies, presents a promising avenue for treating solid tumors, including CRC. This review explores the potential of CAR-T cell therapy in CRC by analyzing clinical trials and highlighting prominent CRC-specific targets. We discuss the challenges such as immunosuppressive microenvironment, tumor heterogeneity, and physical barriers that limit CAR-T efficacy. Emerging strategies, such as logic-gated and dual-targeting CAR-T cells, offer practical solutions to overcome these hurdles. Furthermore, we explore the combination of CAR-T cell therapy with immune checkpoint inhibitors to enhance T-cell persistence and tumor infiltration. As the field continues to evolve, CAR-T cell therapies hold significant potential for revolutionizing the treatment landscape of CRC.

The Chimeric Antigen Receptor T Cell Target Claudin 6 Is a Marker for Early Organ-Specific Epithelial Progenitors and Is Expressed in Some Pediatric Solid Tumor Entities

Background/Objectives: The oncofetal membrane protein Claudin 6 (CLDN6) is an attractive target for T cell-based therapies. There is a lack of detailed analyses on the age-dependent expression of CLDN6 in normal tissues is lacking, which limits the expansion of CLDN6 CAR-T cell clinical trials to pediatric populations. Methods: We analyzed CLDN6 expression in extracranial solid tumors and normal tissues of children using RNA-sequencing data from over 500 pediatric solid tumor samples, qRT-PCR and immunohistochemistry (IHC) in more than 100 fresh-frozen tumor samples and, approximately, 250 formalin-fixed paraffin-embedded (FFPE) samples. We examined normal tissue expression via qRT-PCR in 32 different infant tissues and via IHC in roughly 290 tissues from donors across four age groups, as well as in fetal autopsy samples. Results: In fetal tissues, we detected CLDN6 expression primarily in the epithelial cells of several organs, including the skin, lungs, kidneys, intestinal tract, and pancreas, but not in undifferentiated blastemal cells. Postnatally, we found CLDN6-positive epithelial progenitors only during the first few weeks of life. In older-age groups, isolated clusters of CLDN6-positive progenitors were present, but in scarce quantities. In tumor tissues, we found strong and homogeneous CLDN6 expression in desmoplastic small round cell tumors and germ cell tumors. Wilms tumors demonstrated heterogeneous CLDN6 expression, notably absent in the blastemal component. Conclusions: These findings highlight an organ-specific presence of CLDN6-positive epithelial precursors that largely disappear in terminally differentiated epithelia within weeks after birth. Therefore, our data support CLDN6 as a viable therapeutic target in pediatric patients and justify their inclusion in basket studies for anti-CLDN6-based therapies.

Solid tumour cellular therapy - principles of toxicity management

Following the Food and Drug Administration (FDA) approval of lifileucel and afami-cel for patients with advanced melanoma and synovial sarcoma, respectively, there is a need for improved understanding and guidance regarding the management of toxicity associated with adoptive cellular therapies (ACTs) for solid tumours. Further approvals are expected in coming years, with toxicity management representing a significant consideration for centres looking to implement such advanced therapy medicinal products. Importantly, first-generation tumour-infiltrating lymphocyte therapies are associated with unique toxicities compared with gene-modified T-cell therapies such as chimeric antigen receptor T-cell therapy (CAR T) and T-cell receptor-modified therapy (TCR T), presenting novel challenges for treating healthcare professionals. Extrapolating from experience with CAR T in the field of haemato-oncology, coupled with the historical use of high-dose interleukin-2 in solid tumour therapeutic regimens and more recently lifileucel and afami-cel, has led to the development of core principles for managing toxicity, which is discussed here. Looking to the future, a rapidly developing field with next-generation ACT products, a basic knowledge of such core principles will be an important foundation for healthcare professionals working in this space.

Recent advances in immunotherapy for cervical cancer

Cervical cancer is the third most common malignant tumor in women worldwide in terms of both incidence and mortality. The field of cervical cancer treatment is rapidly evolving, and various combination therapies are being explored to enhance the efficacy of immune checkpoint inhibitors (ICI) and provide new treatment options for patients at different disease stages. Clinical trials involving immune checkpoint inhibitors are now being conducted following a phase 3 trial with cemiplimab, an ICI, which demonstrated a significant improvement in prognosis in advanced or metastatic cervical cancer patients. These trials include monotherapy and combination therapy with other immune therapies, chemotherapy, or radiation therapy. Furthermore, other approaches for controlling tumors via the immune system, such as therapeutic vaccination for specific tumor antigens or immune cell therapy including chimeric antigen receptor (CAR)-T cell therapy and tumor-infiltrating lymphocytes are being investigated. Ongoing trials will continue to illuminate the optimal strategies for combining these therapies and addressing challenges associated with immune checkpoint failure in cervical cancer. Herein, we conducted a review of articles related to immunotherapy for cervical cancer and describe current treatment strategies for cervical cancer via immunotherapy.

Prospects and Challenges of Immunotherapy for Thyroid Cancer

BACKGROUND

Thyroid cancer generally boasts a favorable prognosis; however, advanced and refractory cases exhibit aggressive characteristics and resistance to conventional therapies, necessitating the investigation of innovative treatment modalities. Immunotherapy, which harnesses the body's immune system to target cancer cells, has shown considerable promise for specific thyroid cancer subtypes.

OBJECTIVE

This review article aims to encapsulate the latest advancements in immunotherapy for thyroid cancer, examining its mechanisms, therapeutic efficacy, ongoing challenges, and the potential benefits of combination therapy approaches.

METHODS

An extensive literature review and critical analysis of clinical trial data were conducted to inform this synthesis.

RESULTS

The review reveals that immunotherapy strategies, encompassing immune checkpoint inhibitors, CAR-T cell therapy, tumor vaccines, and immunomodulators, are demonstrating efficacy in the treatment of thyroid cancer. Notably, checkpoint inhibitors have been particularly effective in anaplastic and poorly differentiated thyroid cancers, albeit with challenges such as treatment resistance and adverse effects. The application of CAR-T cell therapy, successful in hematologic cancers, provides a novel perspective for thyroid cancer treatment, although its efficacy in solid tumors requires further study. Additionally, research into tumor vaccines and immunomodulators is advancing, with preliminary evidence suggesting their therapeutic potential for thyroid cancer patients.

CONCLUSION

The recognition of the immune microenvironment's role in treatment responsiveness is pivotal for enhancing the care of thyroid cancer patients. This review underscores the significance of combination therapy as a means to optimize treatment outcomes and charts a course for future research endeavors to broaden the spectrum of effective treatment options available to thyroid cancer patients.

Targeting refractory diffuse large B cell lymphoma by CAR-WEE1 T-cells: In vitro evaluation

Refractory Diffuse Large B-cell Lymphoma (DLBCL) presents a major therapeutic challenge due to its resistance to standard treatments. Engineered T-cells, especially Chimeric Antigen Receptor (CAR) T-cells, have shown promise in overcoming drug resistance. This study investigates the effectiveness of WEE1-engineered T-cells in targeting and eliminating refractory DLBCL in vitro. CAR T-cells were created by transducing a 5th-generation CAR construct designed to recognize WEE1, a surface antigen commonly found on refractory DLBCL cells. The cytotoxic effect of engineered T-cells was tested against Rituximab-resistant DLBCL cells (RR-NU-DUL-1). Apoptosis and cell cycle were evaluated using flow cytometry. Quantitative Real-time PCR (RT-PCR) was used to measure the expression of WEE1, BCL2, and CDK2. The results showed a significant increase in target cell lysis, apoptosis, and necrosis, a significant reduction in the percentage of cells in the G2M phase of the cell cycle, as well as a decrease in gene expression level, indicating strong anti-tumor activity. These findings suggest that CAR T-cell therapy holds great promise for treating refractory DLBCL, offering a potential path for clinical application. This in vitro evaluation highlights the potential of WEE1-engineered T-cells as a targeted treatment strategy for refractory DLBCL, emphasizing their clinical applicability and ability to overcome resistance mechanisms in this aggressive lymphoma subtype.

Narrative review of 3D bioprinting for the construction of in vitro tumor models: present and prospects

Background and Objective

The conventional in vitro research on tumor mechanisms is typically based on two-dimensional (2D) culture of tumor cells, which has many limitations in replicating in vivo tumorigenesis processes. In contrast, the three-dimensional (3D) bioprinting has paved the way for the construction of more biomimetic in vitro tumor models. This article comprehensively elucidates the features of 3D bioprinting and meticulously summarizes its applications in several selected tumors, aiming to offer valuable insights for future relevant studies.

Methods

A literature search was conducted in the databases of PubMed and Web of Science for articles on 3D bioprinting for in vitro tumor model construction.

Key Content and Findings

This article introduces various 3D bioprinting technologies for in vitro tumor model construction, focusing on their pros and cons, principles, and protocols. Several in vitro tumor models are presented, detailing their utility in tumorigenesis research and their constraints. To date, 3D bioprinting has been widely applied in oncology, addressing the limitation of traditional 2D tumor cell culture in replicating tumor microenvironment (TME).

Conclusions

Advanced 3D bioprinting technology accurately replicates the complex TME and the heterogeneity of intratumor structures, enabling further in vitro tumor studies. It significantly fuels our understanding of tumor pathophysiology and offers new hope for cancer patients.

Resistance to immunotherapy in non-small cell lung cancer: Unraveling causes, developing effective strategies, and exploring potential breakthroughs

Over the last two decades, advancements in deciphering the intricate interactions between oncology and immunity have fueled a meteoric rise in immunotherapy for non-small cell lung cancer, typified by an explosive growth of immune checkpoint inhibitors. However, resistance to immunotherapy remains inevitable. Herein we unravel the labyrinthine mechanisms of resistance to immunotherapy, characterized by their involvement of nearly all types of cells within the body, beyond the extrinsic cancer cells, and importantly, such cells are not only (inhibitory or excitatory, or both) signal recipients but also producers, acting in a context-dependent manner. At the molecular level, these mechanisms underlie genetic and epigenetic aberrations, which are regulated by or regulate various protein kinases, growth factors, and cytokines with inherently dynamic and spatially heterogeneous properties. Additionally, macroscopic factors such as nutrition, comorbidities, and the microbiome within and around organs or tumor cells are involved. Therefore, developing therapeutic strategies combined with distinct action informed by preclinical, clinical, and real-world evidence, such as radiotherapy, chemotherapy, targeted therapy, antibody-drug conjugates, oncolytic viruses, and cell-based therapies, may stand as a judicious reality, although the ideality is to overcome resistance point-by-point through a novel drug. Notably, we highlight a realignment of treatment aims, moving the primary focus from eliminating cancer cells -- such as through chemotherapy and radiotherapy -- to promoting immune modulation and underscore the value of regulating various components within the host macro- or micro-environment, as their effects, even if seemingly minimal, can cumulatively contribute to visible clinical benefit when applied in combination with ICIs. Lastly, this review also emphasizes the current hurdles scattered throughout preclinical and clinical studies, and explores evolving directions in the landscape of immunotherapy for NSCLC.

Targeting HLA-E-overexpressing cancers with a NKG2A/C switch receptor

BACKGROUND

Human leukocyte antigen (HLA)-E is overexpressed by a large proportion of solid tumors, including malignant glioblastoma, and acts as a major checkpoint for NKG2A+ CD8+ T cells and natural killer (NK) cells in the tumor microenvironment and circulation. This axis operates alongside PD-L1 to inhibit effector responses by T and NK cells.

METHODS

We engineered a chimeric A/C switch receptor, combining the high HLA-E binding affinity of the NKG2A receptor ectodomain with the activating signaling of the NKG2C receptor endodomain. The cytotoxic function of A/C switch-transduced NK and T cells was evaluated against tumor cells with varying levels of HLA-E expression. In vivo efficacy was assessed using a xenograft model of glioblastoma.

FINDINGS

A/C switch-transduced NK and T cells exhibited superior and specific cytotoxicity against tumor cells with medium to high HLA-E expression. A/C switch-expressing human T cells demonstrated enhanced anti-tumor function in a glioblastoma xenograft model. The activity of the modified T cells was governed by an equilibrium between A/C switch levels and HLA-E expression, creating a therapeutic window to minimize on-target, off-tumor toxicities. Normal cells remained insensitive to A/C switch T cells, even after interferon (IFN)-γ pretreatment to induce HLA-E expression.

CONCLUSIONS

The A/C switch receptor effectively targets tumor cells expressing high levels of HLA-E, either alone or in combination with other engineered specificities, to overcome the suppressive NKG2A/HLA-E checkpoint. This approach offers a promising therapeutic strategy with a favorable safety profile for targeting HLA-E-overexpressing tumors.

FUNDING

This work was funded by The Research Council of Norway, the Norwegian Cancer Society, and the National Cancer Institute.

CAR-T therapy for endocrine neoplasms: novel targets and combination of therapies

Endocrine malignancies constitute a heterogeneous tumour group with diverse biological characteristics. While typically indolent, they encompass aggressive types and presence of any metastatic sign indicates a high probability of recurrence and a diminished response to conventional therapies. Chimeric antigen receptor (CAR)-T cell immunotherapy has constituted a revolutionary advance in cancer treatment and exhibited significant potential for application in endocrine cancer. However, limited effectiveness was displayed in clinical application, which necessitates the exploration of novel modalities. Identification of specific and safe targets for endocrine cancer is the initial stage towards establishing a successful CAR-T treatment. Various therapies under investigation offer potential enhancements to CAR T cell efficacy through diverse mechanisms. Herein, we summarize recent advances in identifying targets of endocrine cancer for CAR therapy and provide an overview of combinatorial approaches.

Phase I Study of ROR1-Specific CAR-T Cells in Advanced Hematopoietic and Epithelial Malignancies

PURPOSE

The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is expressed in hematopoietic and epithelial cancers but has limited expression on normal adult tissues. This phase I study evaluated the safety of targeting ROR1 with autologous T lymphocytes engineered to express a ROR1 chimeric antigen receptor (CAR). Secondary objectives evaluated the persistence, trafficking, and antitumor activity of CAR-T cells.

PATIENTS AND METHODS

Twenty-one patients with ROR1+ tumors received CAR-T cells at one of four dose levels: 3.3 × 105, 1 × 106, 3.3 × 106, and 1 × 107 cells/kg body weight, administered after lymphodepletion with cyclophosphamide/fludarabine or oxaliplatin/cyclophosphamide. Cohort A included patients with chronic lymphocytic leukemia (CLL, n = 3); cohort B included patients with triple-negative breast cancer (TNBC, n = 10) or non-small cell lung cancer (NSCLC, n = 8). A second infusion was administered to one patient in cohort A with residual CLL in the marrow and three patients in cohort B with stable disease after first infusion.

RESULTS

Treatment was well tolerated, apart from one dose-limiting toxicity at dose level 4 in a patient with advanced NSCLC. Two of the three (67%) patients with CLL showed robust CAR-T-cell expansion and a rapid antitumor response. In patients with NSCLC and TNBC, CAR-T cells expanded to variable levels and infiltrated tumors poorly and 1 of 18 patients (5.5%) achieved partial response by RECIST 1.1.

CONCLUSIONS

ROR1 CAR-T cells were well tolerated in most patients. Antitumor activity was observed in CLL but was limited in TNBC and NSCLC. Immunogenicity of the CAR and lack of sustained tumor infiltration were identified as limitations. See related commentary by Kobold, p. 437.

CAR-T cell therapy for breast cancer: Current status and future perspective

Within the expanding therapeutic landscape for breast cancer (BC), metastatic breast cancer (MBC) remains virtually incurable and tend to develop resistance to conventional treatments ultimately leading to metastatic progression and death. Cellular immunotherapy (CI), particularly chimeric antigen receptor-engineered T (CAR-T) cells, has emerged as a promising approach for addressing this challenge. In the wake of their striking efficacy against hematological cancers, CAR-T cells have also been used where the clinical need is greatest - in patients with aggressive BCs. Unfortunately, current outcomes fall considerably short of replicating that success, primarily owing to the scarcity of tumor-specific antigens and the immunosuppressive microenvironment within BC. Herein, we provide an up-to-date overview of both preclinical and clinical data concerning the application of CAR-T cell therapy in BC. By surveying the existing literature, we discuss the prevailing constrains of this therapeutic approach and overview possible strategies to advance it in the context of breast malignancies. Possible approaches include employing synthetic biology to refine antigen targeting and mitigate off-target toxicity, utilizing logic-gated CAR constructs to enhance specificity, and leveraging armored CARs to remodel the tumor micro-environment. Temporal and spatial regulation of CAR-T cells using inducible gene switches and external triggers further improves safety and functionality. In addition, promoting T cell homing through chemokine receptor engineering and enhancing manufacturing processes with universal CAR platforms expand therapeutic applicability. These innovations not only address antigen escape and T cell exhaustion but also optimize the efficacy and safety profile of CAR-T cell therapy. We, therefore, outline a trajectory wherein CAR-T cells may evolve from a promising experimental approach to a standard modality in BC therapy.

Peptide-based CAR-NK cells: A novel strategy for the treatment of solid tumors

CAR-T cell therapy has been proven to be effective on hematological tumors, although graft-versus-host disease and cytokine release syndrome(CRS) limit its application to a certain extent. However, CAR-T therapy for solid tumors met challenges, among which the lack of tumor-specific antigens (TSA) and immunosuppressive tumor microenvironment (TME) are the most important factors. CAR-NK could be a good alternative to CAR-T in some ways since they can induce mild CRS and are independent of HLA-matching, but the efficacy of CAR-NKs remains limited in solid tumors. CAR cells armed with multiple tumor targeting molecules may obtain higher therapeutic efficacy against solid tumors. Due to large molecular weight, multivalent scFvs cannot be displayed efficiently on T cells and the high affinity of scFv to the target makes it easy to cause on-target, off-tumor(OTOT) toxicity. Peptides with low molecular weight and slightly lower affinity than scFvs allow immune cells to display multiple peptides to increase killing ability and reduce OTOT toxicity. In our study, peptide-based CAR-NK cells were designed to solve the dilemma of CAR-T in solid tumors. Firstly, the peptide-based CAR-NK92MI cells with A1 peptide were constructed and their inhibitory effects on the growth of A549 tumor cells were identified. Secondly, the tri-specific CAR-NK92MI cells with peptides that simultaneously targeted PD-L1, EGFR and VEGFR2 were developed for the combinatory therapy. Tri-specific CAR-NK92MI exhibited comparable killing activities to scFv-based CAR-NK92MI. Moreover, peptide-based CAR NK92MI mitigated OTOT toxicity. Our study implied that peptide-based CAR-NKs could behave as promising tools in solid tumor.

Combinational CAR T-cell therapy for solid tumors: Requisites, rationales, and trials

Chimeric antigen receptor (CAR) T-cell therapy has achieved potent antitumor efficacy in hematological malignancies; however, because of limitations in CAR T-cell recruitment, infiltration, activation, and functional persistence in the tumor, its efficacy in solid tumors has been suboptimal. To overcome these challenges, combinational strategies that include chemotherapy, radiation therapy, or immune checkpoint inhibitor agent therapy with CAR T-cell therapy are being investigated. The established functional characteristics of the abovementioned therapies provide a rationale for the use of a combinational approach with CAR T cells. Chemotherapy reshapes the peritumoral stroma, decreases the immunosuppressive cell population, and promotes a proinflammatory milieu, all of which allow for increased recruitment, infiltration, and accumulation of CAR T cells. Radiation therapy promotes a chemokine gradient, which augments tumor infiltration by CAR T cells and further increases expression of tumor-associated antigens, allowing for increased activation of CAR T cells. Immune checkpoint inhibitor agent therapy inactivates T-cell exhaustion pathways-most notably, the PD1/PDL1 pathway-thereby improving the functional persistence of CAR T cells and promoting endogenous immunity. In this review, we discuss the requisites and rationales for combinational therapy, and we review 25 ongoing phase I and II clinical trials, of which 4 use chemotherapy, 3 use radiation therapy, 11 use immunotherapy, and 7 use another agent. While safety, efficacy, and improved outcomes are the primary goals of these ongoing studies, the knowledge gained from them will help pave the way for subsequent studies focused on optimizing combinational regimens and identifying predictive biomarkers.

Patient-derived xenograft model in cancer: establishment and applications

The patient-derived xenograft (PDX) model is a crucial in vivo model extensively employed in cancer research that has been shown to maintain the genomic characteristics and pathological structure of patients across various subtypes, metastatic, and diverse treatment histories. Various treatment strategies utilized in PDX models can offer valuable insights into the mechanisms of tumor progression, drug resistance, and the development of novel therapies. This review provides a comprehensive overview of the establishment and applications of PDX models. We present an overview of the history and current status of PDX models, elucidate the diverse construction methodologies employed for different tumors, and conduct a comparative analysis to highlight the distinct advantages and limitations of this model in relation to other in vivo models. The applications are elucidated in the domain of comprehending the mechanisms underlying tumor development and cancer therapy, which highlights broad applications in the fields of chemotherapy, targeted therapy, delivery systems, combination therapy, antibody-drug conjugates and radiotherapy. Furthermore, the combination of the PDX model with multiomics and single-cell analyses for cancer research has also been emphasized. The application of the PDX model in clinical treatment and personalized medicine is additionally emphasized.

Harmonizing the symphony of chimeric antigen receptor T cell immunotherapy with the elegance of biomaterials

Chimeric antigen receptor T cell (CAR-T) immunotherapy has become a heated field of cancer research, demonstrating revolutionary efficacy in refractory and relapsed hematologic malignancies. However, CAR-T therapy has still encountered tough challenges, including complicated and lengthy manufacturing procedures, mediocre targeted delivery, limited therapeutic effect against solid tumors and difficulties in real-time in vivo monitoring. To overcome these limitations, various versatile biomaterials have been used in the above aspects and have improved CAR-T therapy impressively. This review mainly summarizes the latest research progress of biomaterials promoting CAR-T therapy in manufacturing, enhancing targeted delivery and tumor infiltration, and dramatic in vivo tracking to provide new insights and inspiration for clinical treatment.

The molecular receptor NKBB enhances the persistence and anti-hepatocellular carcinoma activity of GPC3 CAR-T cells

Chimeric antigen receptor (CAR) T cells have encouraging results in the treatment of hematological malignancies. However, CAR-T therapy still faces numerous challenges against solid tumors, such as hepatocellular carcinoma (HCC), owing to heterogeneous antigen expression in tumor cells, limited persistence of CAR-T cells, etc. Therefore, to treat HCC more effectively, we connected the molecular receptor NKBB to a second-generation glypican-3 (GPC3) CAR to construct GC3328z-NKBB CAR-T cells, which have double specific targets of GPC3 and NKG2DLs (natural killer group 2, member D ligands), dual co-stimulation of CD28 and 41BB, and a single CD3ζ chain. Our study showed that the molecular receptor NKBB conferred GPC3 CAR-T cells with enhanced migration and infiltration abilities towards HCC, higher central memory T (TCM) cell proportion and proliferation capacity, and reduced exhaustion level. GC3328z-NKBB CAR-T cells exhibited improved cytotoxicity against HCC cells and prolonged persistence. The cathepsin L/interleukin-17 (CTSL/IL-17) axis contributed to the superior anti-HCC activity of GC3328z-NKBB CAR-T cells. Overall, the molecular receptor NKBB significantly increased the persistence of GPC3 CAR-T cells, and GC3328z-NKBB CAR-T cells possessed potent anti-HCC activity in mice, providing a new strategy for the potential improvement of adoptive T cell therapy in the treatment of HCC.

Microenvironment actuated CAR T cells improve solid tumor efficacy without toxicity

A major limiting factor in the success of chimeric antigen receptor (CAR) T cell therapy for the treatment of solid tumors is targeting tumor antigens also found on normal tissues. CAR T cells against GD2 induced rapid, fatal neurotoxicity because of CAR recognition of GD2+ normal mouse brain tissue. To improve the selectivity of the CAR T cell, we engineered a synthetic Notch receptor that selectively expresses the CAR upon binding to P-selectin, a cell adhesion protein overexpressed in tumor neovasculature. These tumor microenvironment actuated T (MEAT) cells ameliorated T cell infiltration in the brain, preventing fatal neurotoxicity while maintaining antitumor efficacy. We found that conditional CAR expression improved the persistence of tumor-infiltrating lymphocytes because of enhanced metabolic fitness of MEAT cells and the infusion of a less differentiated product. This approach increases the repertoire of targetable solid tumor antigens by restricting CAR expression and subsequent killing to cancer cells only and provides a proof-of-concept model for other targets.

Triple knockdown of CD11a, CD49d, and PSGL1 in T cells reduces CAR-T cell toxicity but preserves activity against solid tumors in mice

Chimeric antigen receptor (CAR)-T cell therapies have revolutionized the landscape of cancer treatment, in particular in the context of hematologic malignancies. However, for solid tumors that lack tumor-specific antigens, CAR-T cells can infiltrate and attack nonmalignant tissues expressing the CAR target antigen, leading to on-target, off-tumor toxicity. Severe on-target, off-tumor toxicities have been observed in clinical trials of CAR-T therapy for solid tumors, highlighting the need to address this issue. Here, we demonstrated that targeting the cell adhesion and migration molecules lymphocyte function-associated antigen 1 (LFA-1; CD11a/CD18) and very late activation antigen 4 (VLA-4; CD49d/CD29) with blocking antibodies reduced the on-target, off-tumor toxicity of CAR-T cells in mice. To translate this observation into improved CAR-T cell therapy, we either knocked out both CD11a and CD49d or knocked down CD11a and CD49d along with PSGL1, another cell adhesion molecule, in CAR-T cells. We found that these modified CAR-T cells exhibited reduced on-target, off-tumor toxicity in vivo without affecting CAR-T cell efficacy. Furthermore, we showed that this approach promoted T cell memory formation and decreased tonic signaling. On the basis of these data, we engineered a human version of these low-toxicity CAR-T cells and further validated the feasibility of this approach in vitro and in vivo. Together, these results provide a potential solution to address the clinical challenge of on-target, off-tumor toxicity in CAR-T therapy.

Advancement Opportunities and Endeavor of Innovative Targeted Therapies for Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an intractable disease with rapid progression and high mortality, presenting a persistent obstacle impeding clinical management. Although recent advancements in immunotherapy have enhanced the response rates of platinum-based chemotherapy regimens, the emergence of acquired resistance invariably leads to recurrence and metastasis. Consequently, there is an urgent necessity to explore novel therapeutic targets and optimize existing treatment strategies. This article comprehensively reviews the currently available therapeutic modalities for SCLC. It delves into the immunologic prognostic implications by analyzing selected immune-related signatures. Moreover, it conducts an in-depth exploration of the molecular subtyping of SCLC and the associated molecular pathways to identify potential therapeutic targets. Specifically, the focus is on clinical interventions targeting delta-like ligand 3 (DLL3), elucidating its resistance mechanisms and demonstrating its notable antitumor efficacy. Furthermore, the study examines the mechanisms of chimeric antigen receptor (CAR) T and antibody-drug conjugate (ADC), covering resistance issues and strategies for optimizing resistance management, with particular emphasis being placed on analyzing the prospects and clinical value of CAR T therapy in the context of SCLC. Moreover, the effectiveness of poly ADP-ribose polymerase and ataxia telangiectasia and rad3/checkpoint kinase 1 inhibitors is discussed and underscores the advantages of combining these inhibitors with standard chemotherapy to combat chemoresistance and enhance the antitumor effects of immunotherapies. Overall, this study investigates emerging strategies for targeted therapies and optimized combination regimens to overcome resistance in SCLC and highlights future strategies for new therapeutic technologies for SCLC.

[Preparation of Trop2-Targeted CAR-T Cells Based on Nanobodies and Their Antitumor Effects Against Non-Small Cell Lung Cancer]

Objective

To investigate whether chimeric antigen receptor (CAR) T cells constructed with nanobodies based on trophoblast cell-surface antigen 2 (Trop2) can be used to treat Trop2-positive non-small cell lung cancer.

Methods

A Trop2-specific phage display nanobody library was constructed to screen for Trop2-specific nanobodies. The antigen-binding capacities of three Trop2 nanobodies (8#, 14#, and 48#) were assessed using indirect enzyme-linked immunosorbent assay (ELISA), and their binding affinities were analyzed through surface plasmon resonance (SPR) analysis. CAR-T cells were constructed with Trop2-specific nanobodies and were then co-cultured with the Trop2-positive NCI-H292 cell line expressing luciferase and the Trop2-negative A549 cell line. Luciferase values at effector-to-target ratios of 4∶1, 2∶1, 1∶1, and 1∶2 were measured using a multifunctional microplate reader to assess the killing efficiency. The levels of interleukin (IL)-2, interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) cytokines in the supernatant at an effector-to-target ratio of 4∶1 were measured using the ELISA method. We also established in this study an NCI-H292 xenograft model in NCG immunodeficient mice, which were divided into three groups, a phosphate-buffered saline (PBS) control group, a Mock-T group, and a Trop2 CAR-T group (n = 5). A total of 1×107 Trop2 CAR-T cells were administered via tail vein injection. Throughout the experimental period, the growth and survival status of the mice were observed daily, and tumor sizes were measured once every three days to analyze the survival time.

Results

A Trop2-specific nanobody was successfully screened from the nanobody library, and indirect ELISA initially indicated that nanobody 48# had the strongest affinity. Subsequently, surface plasmon resonance analysis revealed that nanobody 48# exhibited an affinity in the range of 2.49×10－8 M, indicating that it was a high-affinity antibody. Based on this nanobody, Trop2 CAR-T cells were successfully constructed. Furthermore, in vitro experiments demonstrated that Trop2 CAR-T cells killed Trop2-positive NCI-H292 non-small cell lung cancer cells in a dose-dependent manner. ELISA showed a significant increase in the secretion of cytokines (IL-2, IFN-γ, and TNF-α) in the co-culture system, further validating their antitumor activity. In the NCI-H292 xenograft mouse model, the Trop2 CAR-T group exhibited reduced tumor size (P < 0.001) and prolonged survival time of tumor-bearing mice (P < 0.05) compared to the PBS and Mock-T groups.

Conclusion

These findings demonstrate that CAR T cells constructed with Trop2 nanobodies can effectively treat Trop2-positive non-small cell lung cancer.

Neuronal cell adhesion molecule (NRCAM) variant defined by microexon skipping is an essential, antigenically distinct, and targetable proteoform in high-grade glioma

To overcome the paucity of known tumor-specific surface antigens in pediatric high-grade glioma (pHGG), we contrasted splicing patterns in pHGGs and normal brain samples. Among alternative splicing events affecting extracellular protein domains, the most pervasive alteration was the skipping of ≤30 nucleotide-long microexons. Several of these skipped microexons mapped to L1-IgCAM family members, such as NRCAM . Bulk and single-nuclei short- and long-read RNA-seq revealed uniform skipping of NRCAM microexons 5 and 19 in virtually every pHGG sample. Importantly, the Δex5Δex19 (but not the full-length) NRCAM proteoform was essential for pHGG cell migration and invasion in vitro and tumor growth in vivo. We developed a monoclonal antibody selective for Δex5Δex19 NRCAM and demonstrated that "painting" of pHGG cells with this antibody enables killing by T cells armed with an FcRI-based universal immune receptor. Thus, pHGG-specific NRCAM and possibly other L1-IgCAM proteoforms are promising and highly selective targets for adoptive immunotherapies.

Statement of significance

Existing targets for chimeric antigen receptors (CAR)-armed T cells are often shared by CNS tumors and normal tissues, creating the potential for on-target/off-tumor toxicities. Here we demonstrate that in CNS tumors of glial origin, cell adhesion molecules have alternatively spliced proteoforms, which could be targeted by highly selective therapeutic antibodies.

Treponema denticola major surface protein (Msp): a key player in periodontal pathogenicity and immune evasion

Treponema denticola, a bacterium that forms a "red complex" with Porphyromonas gingivalis and Tannerella forsythia, is associated with periodontitis, pulpitis, and other oral infections. The major surface protein (Msp) is a surface glycoprotein with a relatively well-established overall domain structure (N-terminal, central and C-terminal regions) and a controversial tertiary structure. As one of the key virulence factors of T. denticola, Msp is associated with adherence, immune response, and pore formation by the microorganism. It also mediates several pathological changes in histocytes, such as cytoskeleton disruption, neutrophil phagocytosis, and phosphoinositide balance interruption. In addition, the Msp of T. denticola is also an ortholog of the Treponema pallidum repeat (Tpr) proteins and Msp or Msp-like proteins that have been detected in other oral treponeme species. This review will discuss the structure, pathogenicity and homologs of Msp produced by T. denticola, illuminate the controversy regarding the structure and membrane topology of native Msp, explore the potential roles of Msp in the mechanism of T. denticola immune escape and provide an overview of the cytotoxicity and adherence ability of Msp. Further understanding of the structure and functions of Msp will offer new insights that will help promote further investigations of the pathogenic mechanisms of T. denticola and other treponemes, leading to more effective prophylactic or therapeutic treatments for relevant diseases.

The high efficacy of claudin18.2-targeted CAR-T cell therapy in advanced pancreatic cancer with an antibody-dependent safety strategy

Pancreatic cancer (PC) is one of the most lethal digestive system tumors. Claudin18.2 is highly expressed in PC tissue and could serve as a suitable target for CAR-T therapy. In the present study, we reported the utilization of tEGFR-expressing claudin18.2-targeted CAR-T cells to treat 3 patients with advanced PC. Intriguingly, all 3 patients achieved disease remission after CAR-T cell infusion, with 1 complete remission (CR) and 2 partial remissions (PRs). However, gastric mucosal injury was observed, which was recognized as on-target off-tumor toxicity (OTOT) and may be due to the expression of claudin18.2 on normal gastric tissues. To control the severe OTOT in patient 3, cyclophosphamide and cetuximab were administered to deplete CAR-T cells, and they successfully controlled OTOT. Single-cell transcriptome and T cell receptor sequencing revealed the objective alterations of CAR-T cell clones after cetuximab treatment. Collectively, the present study showed the robust anti-tumor activity of claudin18.2-targeted CAR-T cells against PC and reported the feasibility of the antibody-dependent safety switch strategy to control the OTOT caused by CAR-T cells in patients. Our study may pave the way for the development of a novel strategy to treat patients with advanced PC in the future.

Expression-Dependent Tumor Pretargeting via Engineered Avidity

Selective delivery of therapeutic modalities to tumor cells via binding of tumor-selective cell-surface biomarkers has empowered substantial advances in cancer treatment. Yet, tumor cells generally lack a truly specific biomarker that is present in high density on tumor tissue while being completely absent from healthy tissue. Rather, low but nonzero expression in healthy tissues results in on-target, off-tumor activity with detrimental side effects that constrain the therapeutic window or prevent use altogether. Advanced technologies to enhance the selectivity for tumor targeting are sorely needed. We have engineered a binding platform that is quantitatively dependent upon expression levels, via avidity-driven specificity, rather than binarily reliant on the presence or absence of a biomarker. We systematically varied monomeric binding affinity by engineering affibodies to target carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) and folate receptor 1 (FolR1). Two identical affibody ligands were tethered, with varying polypeptide linker lengths, to a nanobody that binds Alfa peptide to create a bispecific, trivalent protein for use in pretargeted radioligand therapy. Expression-dependent targeting was achieved in both systems: with 110 nM monomeric affinity to CEACAM5 with a two-amino-acid linker or with 250 nM monomeric affinity for FolR1 and a 10 amino acid linker. The latter bispecific, trivalent achieved over 25-fold differentiation between FolR1high and FolR1low cells in a mixed culture. Similar selectivity was achieved in a size-efficient bivalent molecule lacking a central nanobody. Moreover, the avid bivalent affibody molecule exhibited minimal inhibition by soluble antigen, whereas high-affinity bivalent antibody was inhibited by 97 ± 2%, which is indicative of serum inhibition of shed antigen. This work advances design principles for achieving expression-dependent tumor targeting via low-affinity, high-avidity ligands.

Exploring CAR-macrophages in non-tumor diseases: Therapeutic potential beyond cancer

BACKGROUND

After significant advancements in tumor treatment, personalized cell therapy based on chimeric antigen receptors (CAR) holds promise for transforming the management of various diseases. CAR-T therapy, the first approved CAR cell therapy product, has demonstrated therapeutic potential in treating infectious diseases, autoimmune disorders, and fibrosis. CAR-macrophages (CAR-Ms) are emerging as a promising approach in CAR immune cell therapy, particularly for solid tumor treatment, highlighting the feasibility of using macrophages to eliminate pathogens and abnormal cells.

AIM OF REVIEW

This review summarizes the progress of CAR-M therapy in non-tumor diseases and discusses various CAR intracellular activation domain designs and their potential to optimize therapeutic effects by modulating interactions between cellular components in the tissue microenvironment and CAR-M. Additionally, we discuss the characteristics and advantages of CAR-M therapy compared to traditional medicine and CAR-T/NK therapy, as well as the challenges and prospects for the clinical translation of CAR-M.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review provides a comprehensive understanding of CAR-M for the treatment of non-tumor diseases, analyzes the advantages and characteristics of CAR-M therapy, and highlights the important impact of CAR intracellular domain design on therapeutic efficacy. In addition, the challenges and clinical translation prospects of developing CAR-M as a new cell therapy are discussed.

Inhalable nanovesicles loaded with a STING agonist enhance CAR-T cell activity against solid tumors in the lung

Suppression of chimeric antigen receptor-modified T (CAR-T) cells by the immunosuppressive tumor microenvironment remains a major barrier to their efficacy against solid tumors. To address this, we develop an anti-PD-L1-expressing nanovesicle loaded with the STING agonist cGAMP (aPD-L1 NVs@cGAMP) to remodel the tumor microenvironment and thereby enhance CAR-T cell activity. Following pulmonary delivery, the nanovesicles rapidly accumulate in the lung and selectively deliver STING agonists to PD-L1-overexpressing cells via the PD-1/PD-L1 interaction. This targeted delivery effectively avoids the systemic inflammation and poor cellular uptake that plague free STING agonists. Internalized STING agonists trigger STING signaling and induce interferon responses, which diminish immunosuppressive cell populations such as myeloid-derived suppressor cells in the tumor microenvironment and promote CAR-T cell infiltration. Importantly, the anti-PD-L1 single chain variable fragment on the nanovesicle surface blocks PD-L1 upregulation induced by STING agonists and prevents CAR-T cell exhaustion. In both orthotopic lung cancer and lung metastasis model, combined therapy with CAR-T cells and aPD-L1 NVs@cGAMP potently inhibits tumor growth and prevents recurrence. Therefore, aPD-L1 NVs@cGAMP is expected to serve as an effective CAR-T cell enhancer to improve the efficacy of CAR-T cells against solid tumors.

A framework integrating multiscale in-silico modeling and experimental data predicts CD33CAR-NK cytotoxicity across target cell types

Uncovering mechanisms and predicting tumor cell responses to CAR-NK cytotoxicity is essential for improving therapeutic efficacy. Currently, the complexity of these effector-target interactions and the donor-to-donor variations in NK cell receptor (NKR) repertoire require functional assays to be performed experimentally for each manufactured CAR-NK cell product and target combination. Here, we developed a computational mechanistic multiscale model which considers heterogenous expression of CARs, NKRs, adhesion receptors and their cognate ligands, signal transduction, and NK cell-target cell population kinetics. The model trained with quantitative flow cytometry and in vitro cytotoxicity data accurately predicts the short- and long-term cytotoxicity of CD33CAR-NK cells against leukemia cell lines across multiple CAR designs. Furthermore, using Pareto optimization we explored the effect of CAR proportion and NK cell signaling on the differential cytotoxicity of CD33CAR-NK cells to cancer and healthy cells. This model can be extended to predict CAR-NK cytotoxicity across many antigens and tumor targets.

Cell therapies for viral diseases: a new frontier

Despite advances in medicine and antimicrobial research, viral infections continue to pose a major threat to human health. While major strides have been made in generating vaccines and small molecules to combat emerging pathogens, new modalities of treatment are warranted in diseases where there is a lack of treatment options, or where treatment cannot fully eradicate pathogens, as in HIV infection. Cellular therapies, some of which are FDA approved for treating cancer, take advantage of our developing understanding of the immune system, and harness this knowledge to enhance, or direct, immune responses toward infectious agents. As with cancer, viruses that evade immunity, do so by avoiding immune recognition or by redirecting the cellular responses that would eradicate them. As such, infusing virus specific immune cells has the potential to improve patient outcomes and should be investigated as a potential tool in the arsenal to fight infection. The present manuscript summarizes key findings made using cellular therapies for the treatment of viral infections, focusing on the potential that these strategies might have in controlling disease.

Cell-Based Therapies in GI Cancers: Current Landscape and Future Directions

Cell-based therapies have become integral to the routine clinical management of hematologic malignancies. Tumor-infiltrating lymphocyte (TIL) therapy has demonstrated efficacy in immunogenic solid tumors, such as melanoma. However, in the GI field, evidence supporting the clinical success of cell-based therapies is still awaited. CLDN18.2, a key tight junction molecule in stomach epithelium, has emerged as a promising target for gastric cancer (GC) treatment. Because of its lineage-specific expression, significant efforts have been made to develop chimeric antigen receptor T-cell (CAR-T) therapies targeting CLDN18.2. These therapies have shown encouraging tumor shrinkage in patients with heavily pretreated GC. However, durable responses remain uncommon. CAR-T exhaustion driven by immune-suppressive cells in the tumor microenvironment, along with the heterogeneous expression of target molecules, poses significant challenges. In addition, managing on-target, off-tumor toxicities remains a critical issue in therapies targeting tissue-associated antigens. Next-generation CARs are expected to address these resistance mechanisms. Furthermore, adoptive macrophage and natural killer cell therapies hold promise for not only their efficacy but also for the ease off-the-shelf production. Advanced neoantigen prediction and identification of optimal T-cell activation targets could facilitate the clinical application of TIL and T-cell receptor-T therapies in GI cancers. Cell-based therapies might have the potential to transform the treatment landscape for GI cancers.