Tumor immunotherapy resistance: Revealing the mechanism of PD-1 / PD-L1-mediated tumor immune escape

Cost-effective strategies for CAR-T cell therapy manufacturing

CAR-T cell therapy has revolutionized cancer treatment, with approvals for conditions like acute B-leukemia, large B cell lymphoma (LBCL), follicular lymphoma (FL), mantle cell lymphoma (MCL), and multiple myeloma. However, its high costs limit accessibility. Key factors driving these costs include the need for personalized, autologous treatments, transportation to specialized facilities, reliance on viral vectors requiring advanced laboratories, and lengthy cell expansion processes. To address these challenges, alternative strategies aim to simplify and reduce production complexity. Non-viral vectors, such as Sleeping Beauty, piggyBac, and CRISPR, delivered via nanoparticles or electroporation, present promising solutions. These methods could streamline manufacturing, eliminate the need for viral vectors, and reduce associated costs. Furthermore, shortening cell expansion periods and optimizing protocols could significantly accelerate production. An emerging approach involves using genetically edited T cells from healthy donors to create universal CAR-T products capable of treating multiple patients. Finally, decentralized point-of-care (POC) manufacturing of CAR-T cells minimize logistical expenses, eliminating the need for complex infrastructure, and enabling localized production closer to patients. This innovative strategy holds potential for broadening access and reducing costs, representing a step toward democratizing CAR-T therapy. Combined, these advances could make this groundbreaking treatment more feasible for healthcare systems worldwide.

The dual role of chaperone-mediated autophagy in the response and resistance to cancer immunotherapy

Cancer immunotherapy has become a revolutionary strategy in oncology, utilizing the host immune system to fight malignancies. Notwithstanding major progress, obstacles such as immune evasion by tumors and the development of resistance still remain. This manuscript examines the function of chaperone-mediated autophagy (CMA) in cancer biology, focusing on its effects on tumor immunotherapy response and resistance. CMA is a selective degradation mechanism for cytosolic proteins, which is crucial for sustaining cellular homeostasis and regulating immune responses. By degrading specific proteins, CMA can either facilitate tumor progression in stressful conditions, or promote tumor suppression by removing oncogenic factors. This double-edged sword highlights the complexity of CMA in cancer progression and its possible effect on treatment results. Here we clarify the molecular mechanisms by which CMA can regulate the immune response and its possible role as a therapeutic target for improving the effectiveness of cancer immunotherapy.

Tumor immune evasion and the Let-7 family: insights into mechanisms and therapies

Tumor immune evasion is a complex and adaptive mechanism that allows cancer cells to escape immune detection and destruction, contributing to malignancy progression and poor therapeutic outcomes. This review article explores the integral role of the let-7 family of microRNAs (miRNAs) in mediating tumor immune evasion, particularly how these regulators influence the tumor microenvironment (TME) and immune cell functionality. The let-7 family, known for its tumor-suppressive roles, modulates key immune checkpoints, including PD-L1, and pathways linked to immune response regulation, such as the STAT3/SOCS axis, impacts macrophage polarization and modulates immune cell function. Dysregulation of let-7 miRNAs can enhance tumor immune evasion through mechanisms such as downregulating major histocompatibility complex (MHC) expressions, promoting immunosuppressive cell populations, and manipulating metabolic pathways, which together establish an immunosuppressive TME. Conversely, specific let-7 members show potential in restoring anti-tumor immunity by reversing immune suppression and improving T cell responses. By synthesizing current research, this article underscores the dual role of let-7 in both promoting and inhibiting tumor immune evasion, suggesting their potential as therapeutic targets and biomarkers in cancer immunotherapy. Future studies on the context-dependent roles and advanced delivery systems for let-7-targeting therapies are crucial for enhancing immunotherapeutic efficacy and improving patient outcomes across malignancies.

Engineered Salmonella Carrying siRNA-PD-1 Shrinks orthotopically implanted Bladder Cancer in Rats

Background Currently, the application of engineered bacteria in tumor treatment has received increasing attention. It has been proved that Bacillus Calmette-Guerin (BCG) can effectively treat bladder cancer (BC). In addition, immune checkpoint blockade is an effective method for tumor treatment. Programmed cell death protein 1 (PD-1), an important immunosuppressive molecule, binds to programmed death ligand receptor 1 (PD-L1) and inhibits the anti-tumor effects of T cells.Methods The plasmid encoding siRNA-PD-1 was constructed, and the rat BC in situ model was established. After the treatment, morphological changes in tumor tissue were detected by HE staining, and the apoptotic cells in tumor tissue were detected by TUNEL. The expression of related proteins was detected by Western blotting, and the proportion of CD4+ and CD8+ T cells in spleen was detected by flow cytometry.Results We found that the engineered Salmonella significantly inhibited the growth and incidence of tumors and increased the apoptosis of tumors. Importantly, engineered Salmonella carrying siRNA-PD-1 enhanced the anti-tumor immune response by inhibiting PD-1 expression and increased the CD8+ T cell infiltration in tumor tissue, while elevated the ratio of CD8+/CD4+ in spleens.Conclusion We demonstrated that engineered Salmonella siRNA-PD-1 exerted significant anti-tumor effects on BC.

Innate Immunity and Platelets: Unveiling Their Role in Chronic Pancreatitis and Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal forms of cancer, characterized by a highly desmoplastic tumor microenvironment. One main risk factor is chronic pancreatitis (CP). Progression of CP to PDAC is greatly influenced by persistent inflammation promoting genomic instability, acinar-ductal metaplasia, and pancreatic intraepithelial neoplasia (PanIN) formation. Components of the extracellular matrix, including immune cells, can modulate this progression phase. This includes cells of the innate immune system, such as natural killer (NK) cells, macrophages, dendritic cells, mast cells, neutrophils, and myeloid-derived suppressor cells (MDSCs), either promoting or inhibiting tumor growth. On one hand, innate immune cells can trigger inflammatory responses that support tumor progression by releasing cytokines and growth factors, fostering tumor cell proliferation, invasion, and metastasis. On the other hand, they can also activate immune surveillance mechanisms, which can limit tumor development. For example, NK cells are cytotoxic innate lymphoid cells that are able to kill tumor cells, and active dendritic cells are crucial for a functioning anti-tumor immune response. In contrast, mast cells and MDSCs rather support a pro-tumorigenic tumor microenvironment that is additionally sustained by platelets. Once thought to play a role in hemostasis only, platelets are now recognized as key players in inflammation and cancer progression. By releasing cytokines, growth factors, and pro-angiogenic mediators, platelets help shape an immunosuppressive microenvironment that promotes fibrotic remodeling, tumor initiation, progression, metastasis, and immune evasion. Neutrophils and macrophages exist in different functional subtypes that can both act pro- and anti-tumorigenic. Understanding the complex interactions between innate immune cells, platelets, and early precursor lesions, as well as PDAC cells, is crucial for developing new therapeutic approaches that can harness the immune and potentially also the coagulation system to target and eliminate tumors, offering hope for improved patient outcomes.

Co-blocking TIGIT and PVRIG Using a Novel Bispecific Antibody Enhances Antitumor Immunity

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) and poliovirus receptor-related immunoglobulin domain (PVRIG) are immune checkpoints co-expressed on activated T and NK cells, contributing to tumor immune evasion. Simultaneous blockade of these pathways may enhance therapeutic efficacy, positioning them as promising dual targets for cancer immunotherapy. This study aimed to develop a bispecific antibody (BsAb) to co-target TIGIT and PVRIG. Expression of TIGIT and PVRIG was assessed on tumor-infiltrating lymphocytes from patients with various cancers, including non-small cell lung cancer (n = 63) and colorectal cancer (n = 26). The BsAb was engineered by fusing anti-PVRIG nanobodies to the N terminus of anti-TIGIT antibodies. Functional characterization of the BsAb was performed in vitro and in vivo, including assessments of T- and NK-cell activation and cytotoxicity. Pharmacokinetics and safety profiles were evaluated in cynomolgus monkeys. Statistical analyses were conducted using the Student t test. The results showed that the BsAb effectively blocked TIGIT and PVRIG from binding their respective ligands, CD155 and CD112, leading to significant increases in T-cell activation (2.8-fold; P < 0.05) and NK-cell cytotoxicity (1.8-fold; P < 0.05). In vivo, the BsAb demonstrated potent antitumor activity, both as a monotherapy and in combination with anti-PD-1 or anti-PD-L1, in humanized peripheral blood mononuclear cell-reconstituted and transgenic mouse models. Pharmacokinetic studies in cynomolgus monkeys revealed a favorable profile, with no dose-limiting toxicities observed after four repeated doses of 200 mg/kg. These findings provide compelling preclinical evidence for the therapeutic potential of targeting the TIGIT-PVRIG axis with a BsAb. This approach shows promise for enhancing antitumor immunity and warrants further investigation in clinical trials.

Exploring immune checkpoint inhibitors: Focus on PD-1/PD-L1 axis and beyond

Immunotherapy emerges as a promising approach, marked by recent substantial progress in elucidating how the host immune response impacts tumor development and its sensitivity to various treatments. Immune checkpoint inhibitors have revolutionized cancer therapy by unleashing the power of the immune system to recognize and eradicate tumor cells. Among these, inhibitors targeting the programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have garnered significant attention due to their remarkable clinical efficacy across various malignancies. This review delves into the mechanisms of action, clinical applications, and emerging therapeutic strategies surrounding PD-1/PD-L1 blockade. We explore the intricate interactions between PD-1/PD-L1 and other immune checkpoints, shedding light on combinatorial approaches to enhance treatment outcomes and overcome resistance mechanisms. Furthermore, we discuss the expanding landscape of immune checkpoint inhibitors beyond PD-1/PD-L1, including novel targets such as CTLA-4, LAG-3, TIM-3, and TIGIT. Through a comprehensive analysis of preclinical and clinical studies, we highlight the promise and challenges of immune checkpoint blockade in cancer immunotherapy, paving the way for future advancements in the field.

Therapeutic targeting of the host-microbiota-immune axis: implications for precision health

The human body functions as a complex ecosystem, hosting trillions of microbes that collectively form the microbiome, pivotal in immune system regulation. The host-microbe immunological axis maintains homeostasis and influences key physiological processes, including metabolism, epithelial integrity, and neural function. Recent advancements in microbiome-based therapeutics, including probiotics, prebiotics and fecal microbiota transplantation, offer promising strategies for immune modulation. Microbial therapies leveraging microbial metabolites and engineered bacterial consortia are emerging as novel therapeutic strategies. However, significant challenges remain, including individual microbiome variability, the complexity of host-microbe interactions, and the need for precise mechanistic insights. This review comprehensively examines the host microbiota immunological interactions, elucidating its mechanisms, therapeutic potential, and the future directions of microbiome-based immunomodulation in human health. It will also critically evaluate challenges, limitations, and future directions for microbiome-based precision medicine.

Neoantigen-based immunotherapy: advancing precision medicine in cancer and glioblastoma treatment through discovery and innovation

Neoantigen-based immunotherapy has emerged as a transformative approach in cancer treatment, offering precision medicine strategies that target tumor-specific antigens derived from genetic, transcriptomic, and proteomic alterations unique to cancer cells. These neoantigens serve as highly specific targets for personalized therapies, promising more effective and tailored treatments. The aim of this article is to explore the advances in neoantigen-based therapies, highlighting successful treatments such as vaccines, tumor-infiltrating lymphocyte (TIL) therapy, T-cell receptor-engineered T cells therapy (TCR-T), and chimeric antigen receptor T cells therapy (CAR-T), particularly in cancer types like glioblastoma (GBM). Advances in technologies such as next-generation sequencing, RNA-based platforms, and CRISPR gene editing have accelerated the identification and validation of neoantigens, moving them closer to clinical application. Despite promising results, challenges such as tumor heterogeneity, immune evasion, and resistance mechanisms persist. The integration of AI-driven tools and multi-omic data has refined neoantigen discovery, while combination therapies are being developed to address issues like immune suppression and scalability. Additionally, the article discusses the ongoing development of personalized immunotherapies targeting tumor mutations, emphasizing the need for continued collaboration between computational and experimental approaches. Ultimately, the integration of cutting-edge technologies in neoantigen research holds the potential to revolutionize cancer care, offering hope for more effective and targeted treatments.

Innovative nanoparticle strategies for treating oral cancers

Conventional therapies for oral squamous cell carcinoma (OSCC), a serious worldwide health problem, are frequently constrained by inadequate targeting and serious side effects. Drug delivery systems (DDS) based on nanoparticles provide a possible substitute by improving drug stability, target accuracy, and lowering toxicity. By addressing issues like irregular vasculature and thick tumor matrices, these methods allow for more effective medication administration. For instance, the delivery of cisplatin via liposomes, as opposed to free drug formulations, results in a 40% improvement in tumor suppression. Likewise, compared to traditional techniques, poly (lactic-co-glycolic acid) (PLGA) nanoparticles can produce up to 2.3 times more intertumoral drug accumulation. These platforms have effectively administered natural substances like curcumin and chemotherapeutics like paclitaxel, enhancing therapeutic results while reducing adverse effects. Despite their promise, several types of nanoparticles have drawbacks. For example, PLGA nanoparticles have scaling issues because of their complicated production, whereas liposomes are quickly removed from circulation. In preclinical investigations, functionalized nanoparticles-like EGFR-targeted gold nanoparticles-improve selectivity and effectiveness by obtaining up to 90% receptor binding. By preferentially accumulating in tumors via the increased permeability and retention (EPR) effect, nanoparticles also improve immunotherapy and radiation. Mechanistically, they increase the death of cancer cells by causing DNA damage, interfering with cell division, and producing reactive oxygen species (ROS). There are still issues with toxicity (such as the buildup of metallic nanoparticles in the liver) and large-scale manufacturing. Nevertheless, developments in multifunctional platforms and stimuli-responsive nanoparticles show promise for getting over these obstacles. These developments open the door to more individualized and successful OSCC therapies.

Reprogramming the breast tumor immune microenvironment: cold-to-hot transition for enhanced immunotherapy

This review discusses reprogramming the breast tumor immune microenvironment from an immunosuppressive cold state to an immunologically active hot state. A complex interplay is revealed, in which the accumulation of metabolic byproducts-such as lactate, reactive oxygen species (ROS), and ammonia-is shown to impair T-cell function and promote tumor immune escape. It is demonstrated that the tumor microenvironment (TME) is dominated by immunosuppressive cytokines, including interleukin-10 (IL-10), transforming growth factorβ (TGFβ), and IL-35. Notably, IL-35 is produced by regulatory T cells and breast cancer cells. The conversion of conventional T cells into IL-35-producing induced regulatory T cells, along with the inhibition of pro-inflammatory cytokine secretion, contributes to the suppression of anti-tumor immunity. It is further demonstrated that key immune checkpoint molecules-such as PD-1, PDL1, CTLA-4, TIM-3, LAG-3, and TIGIT-are upregulated within the TME, leading to Tcell exhaustion and diminished immune responses. The blockade of these checkpoints is shown to restore T-cell functionality and is proposed as a strategy to convert cold tumors into hot ones with robust effector cell infiltration. The therapeutic potential of chimeric antigen receptor (CAR)T cell therapy is also explored, and targeting specific tumor-associated antigens, such as glycoproteins and receptor tyrosine kinases, is highlighted. It is suggested that CART cell efficacy can be enhanced by combining these cells with immune checkpoint inhibitors and other immunomodulatory agents, thereby overcoming the barriers imposed by the immunosuppressive TME. Moreover, the role of the microbiome in regulating estrogen metabolism and systemic inflammation is reviewed. Alterations in the gut microbiota are shown to affect the TME, and microbiome-based interventions are proposed as an additional means to facilitate the cold-to-hot transition. It is concluded that by targeting the metabolic and immunological pathways that underpin immune suppression-through combination strategies involving checkpoint blockade, CART cell therapies, and microbiome modulation-the conversion of the breast TME from cold to hot can be achieved. This reprogramming is anticipated to enhance immune cell infiltration and function, thereby improving the overall efficacy of immunotherapies and leading to better clinical outcomes for breast cancer patients.

Discovery of Dual PD-L1/HDAC3 Inhibitors for Tumor Immunotherapy

Targeting programmed cell death protein-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) pathway has been considered as one of the most promising strategies for tumor immunotherapy. However, single-target PD-1/PD-L1 inhibitors frequently exhibit limited efficacy, highlighting the urgent need for new therapies. Herein, a series of dual PD-L1/HDAC3 inhibitors were developed through a pharmacophore fusion strategy for the first time. Among them, compound PH3 was identified as the most promising dual PD-L1/HDAC3 inhibitor, with potent PD-1/PD-L1 inhibitory activity (IC50 = 89.4 nM) and selective HDAC3 inhibitory activity (IC50 = 107 nM). Moreover, PH3 exhibited superior in vitro antitumor activities and in vitro immune activation effects. Additionally, PH3 showed potent and dose-dependent antitumor efficacy in the B16-F10 melanoma mouse model without obvious toxicity. Furthermore, PH3 increased the infiltration of CD3+CD8+ and CD3+CD4+ cells in the tumor microenvironment. Collectively, PH3 represented a novel dual PD-L1/HDAC3 inhibitor deserving further investigation as a tumor immunotherapy agent.

The Role of Monoclonal Antibodies as Therapeutics in HPV-Related Head and Neck Cancers: An Updated Review

BACKGROUND/OBJECTIVES

The increasing prevalence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has necessitated a revaluation of therapeutic strategies. HPV-driven OPSCC differs from HPV-negative OPSCC due to its distinct molecular signatures, increased radiosensitivity, and better prognoses. However, despite these differences, treatment strategies have remained largely uniform, resulting in minimal reductions in morbidity and exposing HPV-positive patients to unnecessary toxicity. Monoclonal antibodies (mAbs) have become a promising therapeutic option due to their ability to target treatment with fewer systemic side effects. Immune checkpoint inhibitors (ICIs) such as pembrolizumab have shown efficacy in enhancing the immune response against tumors, while EGFR inhibitors like cetuximab offer an alternative modality. Current clinical trials aim to refine dosing regimens and identify combination strategies that may enhance therapeutic outcomes.

RESULTS

Despite promising evidence, several challenges hinder the widespread adoption of mAbs as a standard treatment for HPV-positive OPSCC in clinical practice. This review examines the current role of mAbs in HPV-positive OPSCC treatment, highlighting their limitations and future research directions.

CONCLUSIONS

Further studies are needed to optimize patient selection, establish standardized treatment protocols, and investigate the long-term benefits of mAb-based therapies in this patient population.

The potential role of PD-1/PD-L1 small molecule inhibitors in colorectal cancer with different mechanisms of action

Colorectal cancer (CRC) remains one of the leading causes of cancer-related death worldwide, with increasing incidence in younger ages highlighting the need for new or alternative therapy, of which is immune checkpoint inhibitors. Antibody-based immune checkpoint inhibitors targeting the interaction between programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) have revolutionized cancer treatment, including CRC. However, the low response rate in CRC highlights the need for additional research and innovative therapies. Small molecule inhibitors have risen as another strategy worth exploring, considering their potential to target a wide array of PD-1/PD-L1-related pathways. This review focuses on the potential of small molecule inhibitors targeting the PD-1/PD-L1 axis in CRC. Exploring various classes of small molecule inhibitors, including those that directly block the PD-1/PD-L1 interaction and others that target upstream regulators or downstream signaling pathways involved in PD-1/PD-L1-mediated immune suppression. Additionally, modulation of post-transcriptional and post-translational processes, thereby influencing the expression, stability, or localization of PD-1/PD-L1 proteins to enhance antitumor immunity, provides a multifaceted treatment approach. By disrupting these pathways, these inhibitors can restore immune system activity against tumor cells, offering new hope for overcoming resistance and improving outcomes in CRC patients who do not respond to conventional immune checkpoint inhibitors (ICIs). Integrating these small molecules into CRC treatment strategies could represent a promising advancement in the battle against the challenging disease.

Mesenchymal stromal cells in bone marrow niche of patients with multiple myeloma: a double-edged sword

Multiple myeloma (MM) is a hematological malignancy defined by the abnormal proliferation and accumulation of plasma cells (PC) within the bone marrow (BM). While multiple myeloma impacts the bone, it is not classified as a primary bone cancer. The bone marrow microenvironment significantly influences the progression of myeloma and its treatment response. Mesenchymal stromal cells (MSCs) in this environment engage with myeloma cells and other bone marrow components via direct contact and the secretion of soluble factors. This review examines the established roles of MSCs in multiple facets of MM pathology, encompassing their pro-inflammatory functions, contributions to tumor epigenetics, effects on immune checkpoint inhibitors (ICIs), influence on reprogramming, chemotherapy resistance, and senescence. This review investigates the role of MSCs in the development and progression of MM.

Innovative dual-gene delivery platform using miR-124 and PD-1 via umbilical cord mesenchymal stem cells and exosome for glioblastoma therapy

Addressing the challenges of identifying suitable targets and effective delivery strategies is critical in pursuing therapeutic solutions for glioblastoma (GBM). This study focuses on the therapeutic potential of microRNA-124 (miR-124), known for its tumor-suppressing properties, by investigating its ability to target key oncogenic pathways in GBM. The results reveal that CDK4 and CDK6-cyclin-dependent kinases that promote cell cycle progression-are significantly overexpressed in GBM brain samples, underscoring their role in tumor proliferation and identifying them as critical targets for miR-124 intervention. However, delivering miRNA-based therapies remains a major obstacle due to the instability of RNA molecules and the difficulty in achieving targeted, efficient delivery. To address these issues, this research introduces an innovative, non-viral dual-gene delivery platform that utilizes umbilical cord mesenchymal stem cells (UMSCs) and their exosomes to transport miR-124 and programmed cell death protein-1 (PD-1). The efficacy of this dual-gene delivery system was validated using an orthotopic GBM model, which closely mimics the tumor microenvironment seen in patients. Experimental results demonstrate that the UMSC/miR-124-PD-1 complex and its exosomes successfully induce apoptosis in GBM cells, significantly inhibiting tumor growth. Notably, these treatments show minimal cytotoxic effects on normal glial cells, highlighting their safety and selectivity. Moreover, the study highlights the immunomodulatory properties of UMSC/miR-124-PD-1 and its exosomes, enhancing the activation of immune cells such as T cells and dendritic cells, while reducing immunosuppressive cells populations like regulatory T cells and myeloid-derived suppressor cells. The orchestrated dual-gene delivery system by UMSCs and exosomes showcased targeted tumor inhibition and positive immune modulation, emphasizing its potential as a promising therapeutic approach for GBM.

Insights into tumor-derived exosome inhibition in cancer therapy

Exosomes are critical mediators of cell-to-cell communication in physiological and pathological processes, due to their ability to deliver a variety of bioactive molecules. Tumor-derived exosomes (TDEs), in particular, carry carcinogenic molecules that contribute to tumor progression, metastasis, immune escape, and drug resistance. Thus, TDE inhibition has emerged as a promising strategy to combat cancer. In this review, we discuss the key mechanisms of TDE biogenesis and secretion, emphasizing their implications in tumorigenesis and cancer progression. Moreover, we provide an overview of small-molecule TDE inhibitors that target specific biogenesis and/or secretion pathways, highlighting their potential use in cancer treatment. Lastly, we present the existing obstacles and propose corresponding remedies for the future development of TDE inhibitors.

Exploring radiation resistance-related genes in pancreatic cancer and their impact on patient prognosis and treatment

Background

Pancreatic cancer is a highly lethal disease with increasing incidence worldwide. Despite surgical resection being the main curative option, only a small percentage of patients are eligible for surgery. Radiotherapy, often combined with chemotherapy, remains a critical treatment, especially for locally advanced cases. However, pancreatic cancer's aggressiveness and partial radio resistance lead to frequent local recurrence. Understanding the mechanisms of radiotherapy resistance is crucial to improving patient outcomes.

Methods

Pancreatic cancer related gene microarray data were downloaded from GEO database to analyze differentially expressed genes before and after radiotherapy using GEO2R online tool. The obtained differentially expressed genes were enriched by GO and KEGG to reveal their biological functions. Key genes were screened by univariate and multivariate Cox regression analysis, and a risk scoring model was constructed, and patients were divided into high-risk group and low-risk group. Subsequently, Kaplan-Meier survival analysis was used to compare the survival differences between the two groups of patients, further analyze the differential genes of the two groups of patients, and evaluate their sensitivity to different drugs.

Results

Our model identified 10 genes associated with overall survival (OS) in pancreatic cancer. Based on risk scores, patients were categorized into high- and low-risk groups, with significantly different survival outcomes and immune profile characteristics. High-risk patients showed increased expression of pro-inflammatory immune markers and increased sensitivity to specific chemotherapy agents, while low-risk patients had higher expression of immune checkpoints (CD274 and CTLA4), indicating potential sensitivity to targeted immunotherapies. Cross-dataset validation yielded consistent AUC values above 0.77, confirming model stability and predictive accuracy.

Conclusion

This study provides a scoring model to predict radiotherapy resistance and prognosis in pancreatic cancer, with potential clinical application for patient stratification. The identified immune profiles and drug sensitivity variations between risk groups highlight opportunities for personalized treatment strategies, contributing to improved management and survival outcomes in pancreatic cancer.

Evaluating the Tumor Burden, Histological Changes, and Immune Landscape of Breast Cancer Post-neoadjuvant Chemotherapy: Insights From 50 Cases

Breast cancer is a heterogeneous disease with variable responses to neoadjuvant chemotherapy (NACT). Evaluating the histopathological and immune changes in post-NACT breast cancer specimens is crucial for understanding treatment response and guiding further management. This study aims to assess tumor burden using the Residual Cancer Burden (RCB) index, examine histological alterations, evaluate immune activity through tumor-infiltrating lymphocytes (TILs), and analyze proliferative capacity via Ki-67 expression in post-NACT breast cancer specimens. A cross-sectional study of 50 modified radical mastectomy (MRM) specimens post-NACT was conducted. The histopathological analysis included tumor regression changes, stromal and cellular alterations, and nodal involvement. Immune response was assessed by quantifying TILs, and proliferation was measured using the Ki-67 index. Statistical correlations were made between clinicopathological parameters, TILs, and Ki-67 expression. Residual disease was detected in 39 cases (78%), and 11 cases (22%) had no residual disease. Among the 39 cases with residual disease, the majority were classified as RCB II (22 cases, 56%), 16 cases (41%) were classified as RCB III, and one case (3%) was classified as RCB I. Common histological changes post-NACT included fibrosis in 31 cases (62%), necrosis in 19 cases (38%), and infiltration by foamy histiocytes in 16 cases (32%). Malignant epithelial cells more frequently exhibited foamy cytoplasm (16 cases (41%) vs. two cases (5%); p=0.0003), hyperchromatic nucleus (26 cases (67%) vs. six cases (15%); p=0.0001), and prominent nucleoli (26 cases (67%) vs. four cases (10%); p=0.0001) compared to benign cells. Among the 39 cases with residual disease, low TIL and high Ki-67 expression were observed in 20 cases (51%), while 12 cases (32%) showed high TIL and low Ki-67. Residual tumors with high TIL and high Ki-67 (four cases, 10%) and low TIL and low Ki-67 (three cases, 8%) were less common. A significant inverse relationship was found between TIL levels and Ki-67 expression (p=0.0002), as tumors with low TIL were more likely to have high Ki-67 expression (20 cases, 51%), whereas those with high TIL more frequently exhibited low Ki-67 expression (12 cases, 32%). Post-NACT evaluation of tumor burden, immune landscape, and proliferation provides valuable prognostic insights. Integrating RCB, TILs, and Ki-67 into routine pathological assessment may aid patient stratification and guide personalized treatment strategies. Further large-scale studies are needed to validate these findings and improve therapeutic decision-making in breast cancer management.

Mycobacterium tuberculosis infection may increase the degrees of malignancy in lung adenocarcinoma

Background

The early diagnosis and management of lung adenocarcinoma co-existing with tuberculosis (LAC-TB) presents significant challenges in clinical settings. This is compounded by a paucity of robust clinical evidence elucidating the interactions between these two conditions.

Methods

This study included 14 patients diagnosed with LAC-TB, with an equal distribution among those with pulmonary tuberculosis (TB) and those with peripheral lymph node TB. Controls included patients with simple TB and those with lung adenocarcinoma (LAC). Histopathologic examinations confirmed typical changes in each group. Immunohistochemistry analyzed immune markers, focusing on PD-L1, while genomic analysis identified differential mutant genes.

Results

Pathological evaluations showed that LAC-TB and LAC groups expressed TTF-1 and Napsin A in their adenocarcinoma specimens. Notably, a higher proportion of patients in the LAC-TB group had a Ki-67 proliferation index of ≥10%. Subsequent Molecular analyses revealed significant differences in RALGAPA1 gene expression, with the LAC-TB group also exhibiting a greater median count of missense mutations, single nucleotide polymorphisms, and overall mutations, suggesting a higher malignancy level than the LAC group. Additionally, the LAC-TB group showed an increased tumor mutational burden, indicating a potentially better response to immunotherapy. Immunohistochemical assessments indicated that Mycobacterium tuberculosis (MTB) infection correlated with reduced infiltration of T cells and CD4+ T cells, alongside an upregulation of PD-L1 expression in LAC. Notably, PD-L1 was strongly expressed in the TB granuloma and surrounding areas.

Conclusion

Our findings suggest that MTB infection may increase the malignancy of LAC, with the pronounced expression of PD-L1 in granuloma regions constituting a pivotal mechanism underlying this relationship.

Extracellular Vesicle-Based Strategies for Tumor Immunotherapy

Immunotherapy is one of the most promising approaches for cancer management, as it utilizes the intrinsic immune response to target cancer cells. Normally, the human body uses its immune system as a defense mechanism to detect and eliminate foreign objects, including cancer cells. However, cancers develop a 'switch off' mechanism, known as immune checkpoint proteins, to evade immune surveillance and suppress immune activation. Therefore, significant efforts have been made to develop the strategies for stimulating immune responses against cancers. Among these, the use of extracellular vesicles (EVs) to enhance the anti-tumor immune response has emerged as a particularly promising approach in cancer management. EVs possess several unique properties that elevate the potency in modulating immune responses. This review article provides a comprehensive overview of recent advances in this field, focusing on the strategic usage of EVs to overcome tumor-induced immune tolerance. We discuss the biogenesis and characteristics of EVs, as well as their potential applications in medical contexts. The immune mechanisms within the tumor microenvironment and the strategies employed by cancers to evade immune detection are explored. The roles of EVs in regulating the tumor microenvironment and enhancing immune responses for immunotherapy are also highlighted. Additionally, this article addresses the challenges and future directions for the development of EV-based nanomedicine approaches, aiming to improve cancer immunotherapy outcomes with greater precision and efficacy while minimizing off-target effects.

Targeting PI3K signaling in Lung Cancer: advances, challenges and therapeutic opportunities

Lung cancer remains the leading cause of cancer-related mortality globally, necessitating the continual exploration of novel therapeutic targets. The phosphoinositide 3-kinase (PI3K) signaling pathway plays a pivotal role in oncogenic processes, including cell growth, survival, metabolism and immune modulation. This comprehensive review delineates the distinct roles of PI3K subtypes-PI3Kα, PI3Kβ, PI3Kγ and PI3Kδ-in lung cancer pathogenesis and progression. We evaluate the current landscape of PI3K inhibitors, transitioning from non-selective early-generation compounds to isoform-specific agents, highlighting their clinical efficacy, resistance mechanisms and potential combination strategies. Furthermore, the intricate interplay between PI3K signaling and the tumor immune microenvironment is explored, elucidating how PI3K modulation can enhance immunotherapeutic responses. Metabolic reprogramming driven by PI3K signaling is also dissected, revealing vulnerabilities that can be therapeutically exploited. Despite promising advancements, challenges such as therapeutic resistance and adverse effects underscore the need for personalized medicine approaches and the development of next-generation inhibitors. This review underscores the multifaceted role of PI3K in lung cancer and advocates for integrated strategies to harness its full therapeutic potential, paving the way for improved patient outcomes.

Frontiers in pancreatic cancer on biomarkers, microenvironment, and immunotherapy

Pancreatic cancer remains one of the most challenging malignancies to treat due to its late-stage diagnosis, aggressive progression, and high resistance to existing therapies. This review examines the latest advancements in early detection, and therapeutic strategies, with a focus on emerging biomarkers, tumor microenvironment (TME) modulation, and the integration of artificial intelligence (AI) in data analysis. We highlight promising biomarkers, including microRNAs (miRNAs) and circulating tumor DNA (ctDNA), that offer enhanced sensitivity and specificity for early-stage diagnosis when combined with multi-omics panels. A detailed analysis of the TME reveals how components such as cancer-associated fibroblasts (CAFs), immune cells, and the extracellular matrix (ECM) contribute to therapy resistance by creating immunosuppressive barriers. We also discuss therapeutic interventions that target these TME components, aiming to improve drug delivery and overcome immune evasion. Furthermore, AI-driven analyses are explored for their potential to interpret complex multi-omics data, enabling personalized treatment strategies and real-time monitoring of treatment response. We conclude by identifying key areas for future research, including the clinical validation of biomarkers, regulatory frameworks for AI applications, and equitable access to innovative therapies. This comprehensive approach underscores the need for integrated, personalized strategies to improve outcomes in pancreatic cancer.

Immune Cell Interactions and Immune Checkpoints in the Tumor Microenvironment of Gastric Cancer

Gastric cancer (GC) ranks as the fifth most prevalent malignant neoplasm globally, with an increased death rate despite recent advancements in research and therapeutic options. Different molecular subtypes of GC have distinct interactions with the immune system, impacting the tumor microenvironment (TME), prognosis, and reaction to immunotherapy. Tumor-infiltrating lymphocytes (TILs) in the TME are crucial for preventing tumor growth and metastasis, as evidenced by research showing that patients with GC who have a significant density of TILs have better survival rates. But cancer cells have evolved a variety of mechanisms to evade immune surveillance, both sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) and Programmed Death-Ligand 1 (PD-L1) playing a pivotal role in the development of an immunosuppressive TME. They prevent T cell activation and proliferation resulting in a decrease in the immune system's capacity to recognize and eliminate malignant cells. These immune checkpoint molecules function via different but complementary mechanisms, the expression of Siglec-15 being mutually exclusive with PD-L1 and, therefore, providing a different therapeutic approach. The review explores how TILs affect tumor growth and patient outcomes in GC, with particular emphasis on their interactions within the TME and potential targeting of the PD-L1 and Siglec-15 pathways for immunotherapy.

Signatures of H3K4me3 modification predict cancer immunotherapy response and identify a new immune checkpoint-SLAMF9

H3 lysine 4 trimethylation (H3K4me3) modification and related regulators extensively regulate various crucial transcriptional courses in health and disease. However, the regulatory relationship between H3K4me3 modification and anti-tumor immunity has not been fully elucidated. We identified 72 independent prognostic genes of lung adenocarcinoma (LUAD) whose transcriptional expression were closely correlated with known 27 H3K4me3 regulators. We constructed three H3K4me3 modification patterns utilizing the expression profiles of the 72 genes, and patients classified in each pattern exhibited unique tumor immune infiltration characteristics. Using the principal component analysis (PCA) of H3K4me3-related patterns, we constructed a H3K4me3 risk score (H3K4me3-RS) system. The deep learning analysis using 12,159 cancer samples from 26 cancer types and 725 cancer samples from 5 immunotherapy cohorts revealed that H3K4me3-RS was significantly correlated with cancer immune tolerance and sensitivity. Importantly, this risk-score system showed satisfactory predictive performance for the ICB therapy responses of patients suffering from several cancer types, and we identified that SLAMF9 was one of the immunosuppressive phenotype and immunotherapy resistance-determined genes of H3K4me3-RS. The mice melanoma model showed Slamf9 knockdown remarkably restrained cancer progression and enhanced the efficacy of anti-CTLA-4 and anti-PD-L1 therapies by elevating CD8 + T cell infiltration. This study provided a new H3K4me3-associated biomarker system to predict tumor immunotherapy response and suggested the preclinical rationale for investigating the roles of SLAMF9 in cancer immunity regulation and treatment.

Advancing brain immunotherapy through functional nanomaterials

Glioblastoma (GBM), a highly aggressive brain tumor, poses significant treatment challenges due to its highly immunosuppressive microenvironment and the brain immune privilege. Immunotherapy activating the immune system and T lymphocyte infiltration holds great promise against GBM. However, the brain's low immunogenicity and the difficulty of crossing the blood-brain barrier (BBB) hinder therapeutic efficacy. Recent advancements in immune-actuated particles for targeted drug delivery have shown the potential to overcome these obstacles. These particles interact with the BBB by rapidly and reversibly disrupting its structure, thereby significantly enhancing targeting and penetrating delivery. The BBB targeting also minimizes potential long-term damage. At GBM, the particles demonstrated effective chemotherapy, chemodynamic therapy, photothermal therapy (PTT), photodynamic therapy (PDT), radiotherapy, or magnetotherapy, facilitating tumor disruption and promoting antigen release. Additionally, components of the delivery system retained autologous tumor-associated antigens and presented them to dendritic cells (DCs), ensuring prolonged immune activation. This review explores the immunosuppressive mechanisms of GBM, existing therapeutic strategies, and the role of nanomaterials in enhancing immunotherapy. We also discuss innovative particle-based approaches designed to traverse the BBB by mimicking innate immune functions to improve treatment outcomes for brain tumors.

JR, Xu Z, Wang S. Ultrasound-Guided Histotripsy Triggers the Release of Tumor-Associated Antigens from Breast Cancers

Background/Objectives: There is increasing evidence to indicate that histotripsy treatment can enhance the host anti-tumor immune responses both locally at the targeting tumor site as well as systemically from abscopal effects. Histotripsy is a non-invasive ultrasound ablation technology that mechanically disrupts target tissue via cavitation. A key factor contributing to histotripsy-induced abscopal effects is believed to be the release of tumor-specific antigens (TSAs) or tumor-associated antigens (TAAs) that induce a systemic immune response. In this study, we studied the effect of histotripsy treatment on the release of HER2, a well-defined TAA target for cancer immunotherapy. Methods: A range of doses of histotripsy administered to HER2-postive mammary tumor cells in an in vitro cell culture system and an ex vivo tumor were applied. In addition, a single dose of histotripsy was used for an in vivo murine tumor model. The released proteins, and specifically HER2, in both tumor cell-free supernatants and tumor cell pellets were analyzed by a BCA protein assay, an ultra-performance liquid chromatography (UPLC) assay, and Western blot. Results: Our results showed that histotripsy could significantly trigger the release of HER2 proteins in the current study. The level of HER2 proteins was actually higher in tumor cell-free supernatants than in tumor cell pellets, suggesting that HER2 was released from the intracellular domain into the extracellular compartment. Furthermore, proportionally more HER2 protein was released at higher histotripsy doses, indicating free HER2 was histotripsy-dose-dependent. Conclusions: In conclusion, we have qualitatively and quantitatively demonstrated that histotripsy treatment triggers the release of HER2 from the tumor cells into the extracellular compartment. The histotripsy-mediated release of HER2 antigens provides important insights into the mechanism underlying its immunostimulation and suggests the potential of TSA/TAA-based immunotherapies in numerous cancer types.

Non-Genetic Biomarkers in Merkel Cell Carcinoma: Prognostic Implications and Predictive Utility for Response to Anti-PD-(L)1 Immune Checkpoint Inhibitors

Merkel cell carcinoma (MCC) is a skin cancer that arises due to either Merkel cell polyomavirus infection (MCPyV) or ultraviolet (UV) radiation exposure, presenting primarily in the head and neck region of fair-skinned males. The recent success of PD-(L)1 immune checkpoint inhibitors (ICIs) in locally advanced/metastatic MCC, with an objective response rate (ORR) around 50% and improved survival, as a first-line treatment has moved ICIs to the forefront of therapy for MCC and generated interest in identifying biomarkers to predict clinical response. The MCC tumour microenvironment (TME) contains various components of the adaptive and innate immune system. These components can contribute to tumour immune escape through immunosuppression by preventing entrance of other immune cells or by aiding in the cytotoxic clearance of tumour cells. We aim to combine information from studies of baseline and on-treatment monitoring of the TME to help predict the success of ICIs in MCC. This review enhances the understanding of how CD8 T cells, γδ T cells and macrophages may impact predictions of response rates to ICIs in MCC patients. These immune cells are non-genetic biomarkers that can also be used to determine prognosis in MCC treatment.

Peptides as Versatile Regulators in Cancer Immunotherapy: Recent Advances, Challenges, and Future Prospects

The emergence of effective immunotherapies has revolutionized therapies for many types of cancer. However, current immunotherapy has limited efficacy in certain patient populations and displays therapeutic resistance after a period of treatment. To address these challenges, a growing number of immunotherapy drugs have been investigated in clinical and preclinical applications. The diverse functionality of peptides has made them attractive as a therapeutic modality, and the global market for peptide-based therapeutics is witnessing significant growth. Peptides can act as immunotherapeutic agents for the treatment of many malignant cancers. However, a systematic understanding of the interactions between different peptides and the host's immune system remains unclear. This review describes in detail the roles of peptides in regulating the function of the immune system for cancer immunotherapy. Initially, we systematically elaborate on the relevant mechanisms of cancer immunotherapy. Subsequently, we categorize peptide-based nanomaterials into the following three categories: peptide-based vaccines, anti-cancer peptides, and peptide-based delivery systems. We carefully analyzed the roles of these peptides in overcoming the current barriers in immunotherapy, including multiple strategies to enhance the immunogenicity of peptide vaccines, the synergistic effect of anti-cancer peptides in combination with other immune agents, and peptide assemblies functioning as immune stimulators or vehicles to deliver immune agents. Furthermore, we introduce the current status of peptide-based immunotherapy in clinical applications and discuss the weaknesses and future prospects of peptide-based materials for cancer immunotherapy. Overall, this review aims to enhance comprehension of the potential applications of peptide-based materials in cancer immunotherapy and lay the groundwork for future research and clinical applications.

Immune Checkpoint Inhibitor-Associated Cutaneous Adverse Events: Mechanisms of Occurrence

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs' unique molecular action that is mainly mediated by the activation of cytotoxic CD4+/CD8+ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs.

Role of PD-1/PD-L1 signaling axis in oncogenesis and its targeting by bioactive natural compounds for cancer immunotherapy

Cancer is a global health problem and one of the leading causes of mortality. Immune checkpoint inhibitors have revolutionized the field of oncology, emerging as a powerful treatment strategy. A key pathway that has garnered considerable attention is programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1). The interaction between PD-L1 expressed on tumor cells and PD-1 reduces the innate immune response and thus compromises the capability of the body's immune system. Furthermore, it controls the phenotype and functionality of innate and adaptive immune components. A range of monoclonal antibodies, including avelumab, atezolizumab, camrelizumab, dostarlimab, durvalumab, sinitilimab, toripalimab, and zimberelimab, have been developed for targeting the interaction between PD-1 and PD-L1. These agents can induce a broad spectrum of autoimmune-like complications that may affect any organ system. Recent studies have focused on the effect of various natural compounds that inhibit immune checkpoints. This could contribute to the existing arsenal of anticancer drugs. Several bioactive natural agents have been shown to affect the PD-1/PD-L1 signaling axis, promoting tumor cell apoptosis, influencing cell proliferation, and eventually leading to tumor cell death and inhibiting cancer progression. However, there is a substantial knowledge gap regarding the role of different natural compounds targeting PD-1 in the context of cancer. Hence, this review aims to provide a common connection between PD-1/PD-L1 blockade and the anticancer effects of distinct natural molecules. Moreover, the primary focus will be on the underlying mechanism of action as well as the clinical efficacy of bioactive molecules. Current challenges along with the scope of future research directions targeting PD-1/PD-L1 interactions through natural substances are also discussed.

Impact of Neoadjuvant Therapy on PD-L1 Expression in Triple-Negative Breast Cancer and Correlation with Clinicopathological Factors

BACKGROUND

This study aims to deliver more insights on the impact of neoadjuvant treatment on Pd-L1 expression and to evaluate its correlation with clinicopathological factors.

METHODS

We reviewed 88 TNBC cases for the period 2021-2023. Data on age, tumor size, stage, and treatment were collected. Histological slides were assessed for subtype, grade, and TILs. A total of 48 received neoadjuvant treatment. HER2 and Ki67 were evaluated via immunohistochemistry. PD-L1 expression was tested on primary and residual tumors. Statistical analysis was performed using IBM SPSS (p < 0.05).

RESULTS

In this study, PD-L1 positive expression was found in 44.3% of primary tumors, with 52.9% of initially positive cases losing expression post-treatment. TILs were significantly higher in PD-L1-positive tumors (mean 41.79% vs. 27.55%, p = 0.001). A notable correlation was found between PD-L1 expression and Ki-67 proliferation index, with PD-L1-positive tumors having a median Ki-67 of 64.49 compared to 52.86 in negative cases (p = 0.015). Neoadjuvant immunotherapy led to a lower mean residual cancer burden (0.95 vs. 2.55, p = 0.002) compared to chemotherapy alone. Higher Ki-67 levels (≥50%) were associated with better treatment outcomes, showing a mean RCB score of 1.60 versus 3.16 for lower levels (p = 0.022). HER2-negative cases had a higher prevalence of favorable pathological response (54.5%) compared to HER2-low tumors (25%, p = 0.048), because of the strong correlation to high proliferative index.

CONCLUSIONS

In conclusion, PD-L1 expression in TNBC shows significant discordance post-treatment, highlighting the need for routine testing and further research on predictive biomarkers.

Holliday junction recognition protein (HJURP) could reflect the clinical outcomes of lung adenocarcinoma patients, and impact the choice of precision therapy

Background

Lung adenocarcinoma (LUAD) is the most prevalent subtype of non-small cell lung cancer (NSCLC), characterized by poor prognosis and a high mortality rate. Identifying reliable prognostic biomarkers and potential therapeutic targets is crucial for improving patient outcomes.

Methods

We conducted a comprehensive analysis of HJURP expression in LUAD using data from four cohorts: TCGA-LUAD (n = 453), GSE31210 (n = 226), GSE68465 (n = 442), and GSE72094 (n = 386). Univariate Cox regression analysis was employed to identify prognostic genes, with Kaplan-Meier survival analysis used to assess the predictive power of HJURP. Functional enrichment analyses were performed using MetaScape and FGSEA, and spatial transcriptomics and single-cell sequencing data were analyzed to explore HJURP's distribution and potential functions. Additionally, correlations between HJURP expression and genetic alterations, immune cell infiltration, and potential therapeutic responses were evaluated.

Results

HJURP was identified as a significant prognostic biomarker in all four cohorts, with high expression associated with increased risk of overall survival (OS) death (TCGA-LUAD: HR = 1.93, 95% CI: 1.321-2.815, P < 0.001; GSE31210: HR = 2.75, 95% CI: 1.319-5.735, P = 0.007; GSE68465: HR = 1.57, 95% CI: 1.215-2.038, P < 0.001; GSE72094: HR = 2.2, 95% CI: 1.485-3.27, P < 0.001). Functional analyses indicated that HJURP is involved in DNA metabolic processes, cell cycle regulation, and mitotic processes, with significant activation of pathways related to MYC targets, G2M checkpoint, and DNA repair. High HJURP expression was associated with higher mutation frequencies in TP53, CSMD3, TTN, and MUC16, and positively correlated with pro-inflammatory immune cell infiltration and several immune checkpoints, including PD-L1 and PD-L2. Chemotherapeutic agents such as gefitinib and sorafenib were predicted to be effective against high HJURP-expressing tumors.

Conclusion

HJURP is a pivotal biomarker for LUAD, consistently associated with poor prognosis and advanced disease stages. Its high expression correlates with specific genetic alterations and immune profiles, highlighting its potential as a therapeutic target. Future studies should validate these findings in larger cohorts.

Expression, regulation, and function of PD-L1 on non-tumor cells in the tumor microenvironment

Antiprogrammed death ligand 1 (PD-L1) therapy is a leading immunotherapy, but only some patients with solid cancers benefit. Overwhelming evidence has revealed that PD-L1 is expressed on various immune cells in the tumor microenvironment (TME), including macrophages, dendritic cells, and regulatory T cells, modulating tumor immunity and influencing tumor progression. PD-L1 can also be located on tumor cell membranes as well as in exosomes and cytoplasm. Accordingly, the dynamic expression and various forms of PD-L1 might explain the therapy's limited efficacy and resistance. Herein a systematic summary of the expression of PD-L1 on different immune cells and their regulatory mechanisms is provided to offer a solid foundation for future studies.

PTBP3 Mediates IL-18 Exon Skipping to Promote Immune Escape in Gallbladder Cancer

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system, with poor response to current treatments. Abnormal alternative splicing has been associated with the development of a variety of tumors. Combining the GEO database and GBC mRNA-seq analysis, it is found high expression of the splicing factor polypyrimidine region- binding protein 3 (PTBP3) in GBC. Multi-omics analysis revealed that PTBP3 promoted exon skipping of interleukin-18 (IL-18), resulting in the expression of ΔIL-18, an isoform specifically expressed in tumors. That ΔIL-18 promotes GBC immune escape by down-regulating FBXO38 transcription levels in CD8+T cells to reduce PD-1 ubiquitin-mediated degradation is revealed. Using a HuPBMC mouse model, the role of PTBP3 and ΔIL-18 in promoting GBC growth is confirmed, and showed that an antisense oligonucleotide that blocked ΔIL-18 production displayed anti-tumor activity. Furthermore, that the H3K36me3 promotes exon skipping of IL-18 by recruiting PTBP3 via MRG15 is demonstrated, thereby coupling the processes of IL-18 transcription and alternative splicing. Interestingly, it is also found that the H3K36 methyltransferase SETD2 binds to hnRNPL, thereby interfering with PTBP3 binding to IL-18 pre-mRNA. Overall, this study provides new insights into how aberrant alternative splicing mechanisms affect immune escape, and provides potential new perspectives for improving GBC immunotherapy.

Predictive Biomarkers and Resistance Mechanisms of Checkpoint Inhibitors in Malignant Solid Tumors

Predictive biomarkers for immune checkpoint inhibitors (ICIs) in solid tumors such as melanoma, hepatocellular carcinoma (HCC), colorectal cancer (CRC), non-small cell lung cancer (NSCLC), endometrial carcinoma, renal cell carcinoma (RCC), or urothelial carcinoma (UC) include programmed cell death ligand 1 (PD-L1) expression, tumor mutational burden (TMB), defective deoxyribonucleic acid (DNA) mismatch repair (dMMR), microsatellite instability (MSI), and the tumor microenvironment (TME). Over the past decade, several types of ICIs, including cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitors, anti-programmed cell death 1 (PD-1) antibodies, anti-programmed cell death ligand 1 (PD-L1) antibodies, and anti-lymphocyte activation gene-3 (LAG-3) antibodies have been studied and approved by the Food and Drug Administration (FDA), with ongoing research on others. Recent studies highlight the critical role of the gut microbiome in influencing a positive therapeutic response to ICIs, emphasizing the importance of modeling factors that can maintain a healthy microbiome. However, resistance mechanisms can emerge, such as increased expression of alternative immune checkpoints, T-cell immunoglobulin (Ig), mucin domain-containing protein 3 (TIM-3), LAG-3, impaired antigen presentation, and alterations in the TME. This review aims to synthesize the data regarding the interactions between microbiota and immunotherapy (IT). Understanding these mechanisms is essential for optimizing ICI therapy and developing effective combination strategies.

Recent Treatment Strategies and Molecular Pathways in Resistance Mechanisms of Antiangiogenic Therapies in Glioblastoma

Malignant gliomas present great difficulties in treatment, with little change over the past 30 years in the median survival time of 15 months. Current treatment options include surgery, radiotherapy (RT), and chemotherapy. New therapies aimed at suppressing the formation of new vasculature (antiangiogenic treatments) or destroying formed tumor vasculature (vascular disrupting agents) show promise. This study summarizes the existing knowledge regarding the processes by which glioblastoma (GBM) tumors acquire resistance to antiangiogenic treatments. The discussion encompasses the activation of redundant proangiogenic pathways, heightened tumor cell invasion and metastasis, resistance induced by hypoxia, creation of vascular mimicry channels, and regulation of the tumor immune microenvironment. Subsequently, we explore potential strategies to overcome this resistance, such as combining antiangiogenic therapies with other treatment methods, personalizing treatments for each patient, focusing on new therapeutic targets, incorporating immunotherapy, and utilizing drug delivery systems based on nanoparticles. Additionally, we would like to discuss the limitations of existing methods and potential future directions to enhance the beneficial effects of antiangiogenic treatments for patients with GBM. Therefore, this review aims to enhance the research outcome for GBM and provide a more promising opportunity by thoroughly exploring the mechanisms of resistance and investigating novel therapeutic strategies.

Cancer Cell Secreted Legumain Promotes Gastric Cancer Resistance to Anti-PD-1 Immunotherapy by Enhancing Macrophage M2 Polarization

The interaction between cancer cells and immune cells plays critical roles in gastric cancer (GC) progression and immune evasion. Forced legumain (LGMN) is one of the characteristics correlated with poor prognosis in gastric cancer patients. However, the role of gastric-cancer-secreted LGMN (sLGMN) in modulating the tumor immune microenvironment and the biological effect on the immune evasion of gastric cancer remains unclear. In this study, we found that forced expression of sLGMN in gastric cancer serum correlates with increased M2 macrophage infiltration in GC tissues and predicted resistance to anti-PD-1 immunotherapy. Mechanistically, gastric cancer cells secrete LGMN via binding to cell surface Integrin αvβ3, then activate Integrin αvβ3/PI3K (Phosphatidylinositol-4,5-bisphosphate3-kinase)/AKT (serine/threonine kinase)/mTORC2 (mammalian target of rapamycin complex 2) signaling, promote metabolic reprogramming, and polarize macrophages from the M1 to the M2 phenotype. Either blocking LGMN, Integrin αv, or knocking out Integrin αv expression and abolishing the LGMN/Integrin αvβ3 interaction significantly inhibits metabolic reprogramming and polarizes macrophages from the M1 to the M2 phenotype. This study reveals a critical molecular crosstalk between gastric cancer cells and macrophages through the sLGMN/Integrinαvβ3/PI3K/AKT/mTORC2 axis in promoting gastric cancer immune evasion and resistance to anti-PD-1 immunotherapy, indicating that the sLGMN/Integrinαvβ3/PI3K/AKT/mTORC2 axis may act as a promising therapeutic target.

PTMs of PD-1/PD-L1 and PROTACs application for improving cancer immunotherapy

Immunotherapy has been developed, which harnesses and enhances the innate powers of the immune system to fight disease, particularly cancer. PD-1 (programmed death-1) and PD-L1 (programmed death ligand-1) are key components in the regulation of the immune system, particularly in the context of cancer immunotherapy. PD-1 and PD-L1 are regulated by PTMs, including phosphorylation, ubiquitination, deubiquitination, acetylation, palmitoylation and glycosylation. PROTACs (Proteolysis Targeting Chimeras) are a type of new drug design technology. They are specifically engineered molecules that target specific proteins within a cell for degradation. PROTACs have been designed and demonstrated their inhibitory activity against the PD-1/PD-L1 pathway, and showed their ability to degrade PD-1/PD-L1 proteins. In this review, we describe how PROTACs target PD-1 and PD-L1 proteins to improve the efficacy of immunotherapy. PROTACs could be a novel strategy to combine with radiotherapy, chemotherapy and immunotherapy for cancer patients.