MYC regulates the antitumor immune response through CD47 and PD-L1

Targeting MYC: Multidimensional regulation and therapeutic strategies in oncology

MYC is dysregulated in approximately 70% of human cancers, strongly suggesting its essential function in cancer. MYC regulates many biological processes, such as cell cycle, metabolism, cellular senescence, apoptosis, angiogenesis, and immune escape. MYC plays a central role in carcinogenesis and is a key regulator of tumor development and drug resistance. Therefore, MYC is one of the most alluring therapeutic targets for developing cancer drugs. Although the search for direct inhibitors of MYC is challenging, MYC cannot simply be assumed to be undruggable. Targeting the MYC-MAX complex has been an effective method for directly targeting MYC. Alternatively, indirect targeting of MYC represents a more pragmatic therapeutic approach, mainly including inhibition of the transcriptional or translational processes of MYC, destabilization of the MYC protein, and blocking genes that are synthetically lethal with MYC overexpression. In this review, we delineate the multifaceted roles of MYC in cancer progression, highlighting a spectrum of therapeutic strategies and inhibitors for cancer therapy that target MYC, either directly or indirectly.

CDC34 suppresses macrophage phagocytic activity and predicts poor response to immune checkpoint inhibitor in cancers

The cell division cycle 34 (CDC34) is an E2 ubiquitin-conjugating enzyme that is required for proteasomal degradation of substrate proteins, and is able to stabilize proteins including the epidermal growth factor receptor to promote lung carcinogenesis. Here, we conducted a pan-cancer analysis of CDC34 in The Cancer Genome Atlas datasets, and found its high expression in breast cancer and negative association with patient outcomes. Analysis of single-cell RNA-sequencing data revealed a negative role of CDC34 in macrophage phagocytotic activity for cancer cells. CDC34 stabilized hypoxia-inducible factor 1α (HIF1α) and transcriptionally upregulated CD47 in cancer cells to evade phagocytosis by macrophages. Inhibition of CDC34 inhibited tumor growth and synergized with anti-PD-L1 antibody in murine models. CDC34 was positively associated with CD47 and negatively associated with CD8+ granzyme B+ T-cell infiltration in patient samples, and patients with co-overexpression of CDC34 and CD47 had markedly poorer prognosis compared to those with high expression of either marker alone. In pre-treatment tumor samples, non-responders to immunotherapy exhibited significantly higher CDC34 levels and reduced CD8+ T-cell infiltration compared to responders. These findings indicated that CDC34 is critical to immune evasion and could be a potential therapeutic target for those resistant to immune checkpoint inhibitors.

USP2 inhibition unleashes CD47-restrained phagocytosis and enhances anti-tumor immunity

The CD47/SIRPα axis conveys a 'don't eat me' signal, thereby thwarting the phagocytic clearance of tumor cells. Although blocking antibodies targeting CD47 have demonstrated promising anti-tumor effects in preclinical models, clinical trials involving human cancer patients have not yielded ideal results. Exploring the regulatory mechanisms of CD47 is imperative for devising more efficacious combinational therapies. Here, we report that inhibiting USP2 prompts CD47 degradation and reshapes the tumor microenvironment (TME), thereby enhancing anti-PD-1 immunotherapy. Mechanistically, USP2 interacts with CD47, stabilizing it through deubiquitination. USP2 inhibition destabilizes CD47, thereby boosting macrophage phagocytosis. Single-cell RNA sequencing shows USP2 inhibition reprograms TME, evidenced by increasing M1 macrophages and CD8+ T cells while reducing M2 macrophages. Combining ML364 with anti-PD-1 reduces tumor burden in mouse models. Clinically, low USP2 expression predicts a better response to anti-PD-1 treatment. Our findings uncover the regulatory mechanism of CD47 by USP2 and targeting this axis boosts anti-tumor immunity.

GW501516 facilitated tumor immune escape by inhibiting phagocytosis

The CD47/SIRPα innate immune checkpoint plays a critical role in regulating tumor immune escape. GW501516, a peroxisome proliferator-activated receptor delta (PPARδ) agonist, is known to promote cancer cell metabolism, proliferation, and inflammation; however, its regulatory mechanism in colon tumor immune escape remains unclear. In this study, qPCR analysis revealed that GW501516 treatment upregulated CD47 gene expression in colon cancer cells. Additionally, GW501516 increased membrane-associated CD47 protein levels in these cells. Mechanistically, luciferase reporter assays demonstrated that GW501516 enhanced CD47 gene transcription activity in colon cancer cells. Co-culture experiments with macrophages further showed that GW501516 treatment suppressed macrophage phagocytic capacity. Crucially, PPARδ knockout abolished GW501516-induced CD47 expression, indicating PPARδ dependency. In vivo implanted tumor models demonstrated that GW501516 facilitated tumor immune escape, whereas PPARδ loss reversed this effect. Collectively, these findings suggest that GW501516 activates PPARδ to promote colon tumor immune escape via CD47 upregulation.

Predictive biomarkers in the era of immunotherapy for gastric cancer: current achievements and future perspectives

Gastric cancer (GC) is one of the primary contributors to cancer-related mortality on a global scale. It holds a position within the top five most prevalent malignancies both in terms of occurrence and fatality rates. Immunotherapy, as a breakthrough cancer treatment, brings new hope for GC patients. Various biomarkers, such as the expression of programmed death ligand-1 (PD-L1), the microsatellite instability (MSI) status, tumor mutational burden (TMB), and Epstein-Barr virus (EBV) infection, demonstrate potential to predict the effectiveness of immunotherapy in treating GC. Nevertheless, each biomarker has its own limitations, which leads to a significant portion of patients continue to be unresponsive to immunotherapy. With the understanding of the tumor immune microenvironment (TIME), genome sequencing technology, and recent advances in molecular biology, new molecular markers, such as POLE/POLD1mutations, circulating tumor DNA, intestinal flora, lymphocyte activation gene 3 (LAG-3), and lipid metabolism have emerged. This review aims to consolidate clinical evidence to offer a thorough comprehension of the existing and emerging biomarkers. We discuss the mechanisms, prospects of application, and limitations of each biomarker. We anticipate that this review will open avenues for fresh perspectives in the investigation of GC immunotherapy biomarkers and promote the precise choice of treatment modalities for gastric cancer patients, thereby advancing precision immuno-oncology endeavors.

CDK4/6 inhibitors in breast cancer therapy: mechanisms of drug resistance and strategies for treatment

Dysregulated cell cycle progression is a well-established hallmark of cancer, driving the development of targeted antitumor therapies that intervene at specific phases of the cell cycle. Among these therapeutic targets, cyclin-dependent kinases 4 and 6 (CDK4/6) have emerged as critical regulators of cell cycle progression, with their aberrant activation being strongly implicated in tumorigenesis and cancer progression. Currently, multiple CDK4/6 inhibitors have received clinical approval for hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer, demonstrating dual therapeutic mechanisms through both cell cycle arrest and enhancement of antitumor immunity. However, clinical implementation faces two major challenges: the inevitable development of acquired resistance during prolonged treatment, and the need for optimized combination strategies with other anticancer agents to achieve synergistic efficacy. This review systematically examines the molecular mechanisms underlying CDK4/6 inhibitor function and characterizes currently approved therapeutic agents. Importantly, it synthesizes recent discoveries regarding resistance mechanisms, including dysregulated cell cycle checkpoints, compensatory signaling pathway activation, and tumor microenvironment adaptations. Furthermore, we critically evaluate emerging combination therapeutic approaches targeting these resistance mechanisms. By integrating mechanistic insights with clinical evidence, this analysis aims to provide actionable strategies for overcoming therapeutic resistance and maximizing the clinical potential of CDK4/6 inhibitors in breast cancer management.

Blood-brain barrier crossing biopolymer targeting c-Myc and anti-PD-1 activate primary brain lymphoma immunity: Artificial intelligence analysis

Primary Central Nervous System Lymphoma is an aggressive central nervous system neoplasm with poor response to pharmacological treatment, partially due to insufficient drug delivery across blood-brain barrier. In this study, we developed a novel therapy for this lymphoma by combining a targeted nanopolymer treatment with an immune checkpoint inhibitor antibody (anti-PD-1). A N-(2-hydroxypropyl)methacrylamide copolymer-based nanoconjugate was designed to block tumor cell c-Myc oncogene expression by antisense oligonucleotide. Angiopep-2 peptide was conjugated to the copolymer to facilitate nanodrug crossing of the blood-brain barrier. Systemically administered polymeric nanodrug, alone or in combination with immune checkpoint inhibitor antibody anti-PD-1, was tested in syngeneic mouse model of A20 intracranial brain lymphoma. There was no significant survival difference between saline- and free anti-PD-1-treated groups. However, significant survival advantage vs. saline was observed upon treatment with nanodrug bearing Angiopep-2, H6 (6 histidines for endosome escape), and c-Myc antisense alone and especially when it was combined with anti-PD-1 antibody. Animal survival after combined treatment was also significantly increased vs. free anti-PD-1. Artificial Intelligence-assisted analysis of gene expression database after RNA-seq of tumors was used to find novel immune pathways, molecular targets and the most effective multifunctional drugs together with future drug prediction for brain lymphoma in vivo model. Spectral flow cytometry and RNA-seq analysis revealed a robust activation of tumor infiltrating T lymphocytes with enhanced interferon γ signaling and polarization to M1-type macrophages in treated tumors, which was confirmed by immunofluorescence staining. In summary, a new effective blood-brain barrier crossing nano immuno therapeutic system was developed that effectively blocked tumor c-Myc acting in combination with immune checkpoint inhibitor anti-PD-1 to treat primary brain lymphoma. The treatment improved survival of tumor-bearing animals through activation of both the adaptive and innate immune responses.

Unlocking the Radiosensitizing Potential of MYC Inhibition in Neuroendocrine Malignancies

The MYC family of transcription factors-comprising c-MYC, N-MYC, and L-MYC-plays a pivotal role in oncogenesis, driving cancer progression and resistance to therapy. While MYC proteins have long been considered challenging drug targets due to their intricate structures, recent advances have led to the development of promising inhibitors. This review explores the role of MYC overexpression in promoting radiation therapy resistance in aggressive neuroendocrine malignancies through multiple mechanisms, including increased tumor cell invasion, enhanced DNA damage repair and oxidative stress management, prosurvival autophagy, survival of circulating tumor cells, angiogenesis, awakening from dormancy, and modulation of chronic inflammation and host immunity. Paradoxically, MYC overexpression can also enhance radiosensitivity in certain cancer cells by driving proapoptotic pathways, such as reactive oxygen species-induced DNA damage that overwhelms cellular repair mechanisms, ultimately leading to cell death. Additionally, we provide a comprehensive summary of direct MYC inhibitors, detailing their current stage of preclinical and clinical development as novel anticancer therapeutics. This review highlights the role of MYC in cancer metastasis and radiation therapy resistance while examining the potential of MYC inhibitors as radiosensitizers in adult and pediatric neuroendocrine malignancies, including small cell lung cancer, large cell neuroendocrine lung cancer, Merkel cell carcinoma, neuroendocrine-differentiated prostate cancer, neuroblastoma, central nervous system embryonal tumors, and medulloblastoma.

Multispecific Antibodies Targeting PD-1/PD-L1 in Cancer

The development of immune checkpoint inhibitors has revolutionized the treatment of patients with cancer. Targeting the programmed cell death protein 1 (PD-1)/programmed cell death 1 ligand 1(PD-L1) interaction using monoclonal antibodies has emerged as a prominent focus in tumor therapy with rapid advancements. However, the efficacy of anti-PD-1/PD-L1 treatment is hindered by primary or acquired resistance, limiting the effectiveness of single-drug approaches. Moreover, combining PD-1/PD-L1 with other immune drugs, targeted therapies, or chemotherapy significantly enhances response rates while exacerbating adverse reactions. Multispecific antibodies, capable of binding to different epitopes, offer improved antitumor efficacy while reducing drug-related side effects, serving as a promising therapeutic approach in cancer treatment. Several bispecific antibodies (bsAbs) targeting PD-1/PD-L1 have received regulatory approval, and many more are currently in clinical development. Additionally, tri-specific antibodies (TsAbs) and tetra-specific antibodies (TetraMabs) are under development. This review comprehensively explores the fundamental structure, preclinical principles, clinical trial progress, and challenges associated with bsAbs targeting PD-1/PD-L1.

Chemotherapy-Mediated Induction of PD-L1 via SEI1 Facilitates Myeloma Immune Evasion

Multiple myeloma (MM) is a plasma cell-derived malignancy. While immune checkpoint blockade immunotherapy has advanced myeloma treatment, chemotherapy remains the primary therapy. How chemotherapy interacts with immune checkpoint expression and impacts immunotherapy efficacy remains unclear. Here it is discovered that chemotherapeutic drugs induce DNA damage and activate the cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway. This activation promotes phosphorylation of the interferon regulatory factor 7 (IRF7), which binds to the promoter region of SERTA-containing domain 1 (SERTAD1, also called SEI1) gene to enhance its transcription. The SEI1 directly interacts with the enhancer factors CREB-binding protein (CBP)/p300 and RNA polymerase II (pol II)-associated factor 1 (PAF1) complex, promoting transcriptional activity and leading to upregulation of programmed death ligand-1 (PD-L1) and immune escape in myeloma. Both in vitro and in vivo experiments demonstrate that treating myeloma cells with PD-L1 antibodies post-chemotherapy significantly enhances the killing efficiency of activated T cells, compared to sequential treatment with chemotherapy and PD-L1 antibodies. This research not only uncovers a pivotal regulatory mechanism of PD-L1 upregulation but also provides a compelling rationale for the integration of chemotherapy and immunotherapy in myeloma treatment.

TBB inhibits CK2/PD-L1/EGFR pathway-mediated tumor progression

The expression of PD-L1 on cancer cells facilitates tumor immune escape by binding to PD-1 on T cells, thereby inhibiting T cell activity. However, the role of intracellular PD-L1 signaling in tumor progression remains unclear. In this study, we demonstrate that CK2 induces PD-L1 phosphorylation at Thr-285, which enhances PD-L1 protein stability. This phosphorylation disrupts the interaction between LC3B and PD-L1, inhibiting PD-L1 degradation via autophagy. Furthermore, PD-L1-T285 phosphorylation promotes EGFR binding to PD-L1, leading to activation of EGFR downstream signaling. This activation drives non-small cell lung cancer (NSCLC) cell proliferation, migration, invasion, and tumor growth. Conversely, CK2 depletion or treatment with a CK2 inhibitor reversed these effects. Our findings reveal a novel mechanism by which the CK2/PD-L1/EGFR pathway promotes tumor progression.

Recent Progress and Potential of G4 Ligands in Cancer Immunotherapy

G-quadruplex (G4) structures are non-canonical nucleic acid conformations that play crucial roles in gene regulation, DNA replication, and telomere maintenance. Recent studies have highlighted G4 ligands as promising anticancer agents due to their ability to modulate oncogene expression and induce DNA damage. By stabilizing G4 structures, these ligands affect tumor progression. Additionally, they have been implicated in tumor immunity modulation, particularly through the activation and immunogenic cell death induction of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. Moreover, their disruption of telomere maintenance and regulation of key oncogenes, such as c-MYC and KRAS, position them as candidates for immune-based therapeutic interventions. Despite their therapeutic potential, challenges remain in optimizing their clinical applications, particularly in patient stratification and elucidating their immunomodulatory effects. This review provides a comprehensive overview of the mechanisms through which G4 ligands influence tumor progression and immune regulation, highlighting their potential role in future cancer immunotherapy strategies.

Olaparib Combined with Anti-PD1 Enhances Immunotherapy of Gastric Cancer Via NF-κB/c-Myc/PD-L1 Signaling

BACKGROUND

PARP inhibitors, effective in BRCA-mutated cancers, show potential in gastric cancer (GC) where homologous recombination defects (e.g., BRCA1/2 mutations) are common. Olaparib, a PARP inhibitor, upregulates PD-L1, suggesting synergy with PD-1 inhibitors for enhanced GC therapy.

METHODS

Using CCK-8 screening of 867 drugs, olaparib demonstrated potent GC cell inhibition. Western blot and qRT-PCR assessed PD-L1, c-MYC, COX-2, and NF-κB pathway proteins (p65/p-p65). Functional assays (Transwell, wound healing, colony formation) evaluated olaparib's effects on GC cell proliferation, migration, and invasion. A GC mouse model tested olaparib combined with anti-PD1. TCGA and Kaplan-Meier analyzed PARP expression-prognosis correlations.

RESULTS

Olaparib suppressed GC cell proliferation, migration, and invasion in vitro. Western blot revealed upregulated c-MYC, COX-2, p65, p-p65, and PD-L1, confirmed by qRT-PCR for PD-L1. Low PARP expression correlated with better GC patient survival. In vivo, olaparib synergized with anti-PD1 to enhance tumor suppression.

CONCLUSION

Olaparib activates the NF-κB/c-MYC pathway to elevate PD-L1, supporting its combination with PD-1 inhibitors as a promising GC therapeutic strategy.

ID3 enhances PD-L1 expression by restructuring MYC to promote colorectal cancer immune evasion

The inhibitor of DNA binding protein ID3 has been associated with the progression of colorectal cancer (CRC). Despite its significance, its specific role in the immune evasion strategies utilized by CRC remains unclear. RNA-seq analysis revealed that ID3 was positively associated with the PD-L1 immune checkpoint. We further demonstrated that tumor cell-expressed ID3 enhanced PD-L1 expression, suppressed the infiltration and activation of CD8+ T cells, and facilitated the immune evasion of CRC cells. Additionally, we found that knockdown of ID3 significantly enhanced the effectiveness of PD-L1 antibody blockade treatment in combating CRC, reduced the upregulation of PD-L1 induced by the antibody, and altered the immune microenvironment within CRC. Mechanistically, ID3 interacted with the transcription factor MYC and reconstructed the four-dimensional structure of MYC, thereby enhancing its binding affinity to the PD-L1 promoter and augmenting PD-L1 transcriptional activity. By integrating analysis of ChIP-seq, RNA-seq, and ImmPort gene sets, we found that ID3's DNA-assisted binding function was widespread and could either enhance or suppress gene transcription, not only affecting tumor immune escape through immune checkpoints but also regulating various cytokines and immune cells involved in tumor immunity. In conclusion, our study uncovers a mechanism by which ID3 promotes immune evasion in CRC and implicates that targeting ID3 may improve the efficacy of anti-PD-1/PD-L1 immunotherapy.

Combination of Sodium Butyrate and Immunotherapy in Glioma: regulation of immunologically hot and cold tumors via gut microbiota and metabolites

Background

Recent studies have highlighted the importance of cross-talk along the gut-brain axis in regulating inflammatory nociception, inflammatory responses, and immune homeostasis. The gut microbiota, particularly its bacterial composition, plays a crucial role in the development and function of the immune system. Moreover, metabolites produced by the gut microbiota can significantly impact both systemic immune responses and central nervous system (CNS) immunity. Sodium butyrate is a key metabolite produced by the gut microbiota and, as a histone deacetylase inhibitor, can enhance the anti-tumor immunity of cytotoxic CD8+ T cells. However, it remains unclear whether sodium butyrate treatment can enhance the efficacy of PD-1 blockade in glioma therapy. In this research, the effect and underlying mechanism of combination of gut microbiota metabolites and anti-mouse PD-1 mAb on glioma has been investigated.

Methods

RNA-seq assay in glioma cell and biomedical databases, including ONCOMINE, GEPIA and TCGA were incorporated. Subsequently, the inhibitory effect of sodium butyrate on glioma cells and its related mechanisms were assessed through Counting Kit-8 (CCK-8), Flow Cytometry, Western blot (WB), reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and other in vitro experiments. In vitro, an orthotopic mouse glioma model was established. MRI imaging, Immunohistochemistry, and Immune cell flow cytometry were used to investigate the therapeutic effects of combined sodium butyrate and PD-1 inhibitor treatment on glioma-bearing mice.

Results

We discovered that deacetylation-associated gene expression is significantly increased in glioma patients and affects patient survival time. Moreover, we found sodium butyrate promoted glioma cell apoptosis, disrupted the cell cycle, and inhibited tumor growth. Additionally, sodium butyrate may upregulate PD-L1 expression in glioma cells by modulating the PI3K/AKT pathway. The experimental results demonstrated that this combination therapy significantly reduced tumor volume and prolonged survival in an orthotopic murine glioma model. Moreover, combination therapy led to an increase in the proportion of probiotic bacteria in the mouse gut microbiota, resulting in elevated levels of antitumor metabolites and a decrease in metabolites that affect immune cell function.

Exosomal CCT3 as a biomarker for diagnosis and immune therapy response in patients diagnosed with hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the dominant type of liver cancer and is associated with a high mortality rate. However, HCC lacks biomarkers for diagnosis and immune therapy response. Tumor-derived exosomes (TDEs) carcinogen-specific molecules have been used for screening multiple biomarkers. This study aimed to identify new biomarkers for the diagnosis of HCC and response to immune checkpoint blockade (ICB) therapy.

METHODS

Analysis of differentially expressed genes (DEGs) in HCC and normal tissues was integrated using The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and ExoCarta datasets. The expression of CCT3 was validated in samples from patients with HCC using quantitative polymerase chain reaction (qPCR), Western blotting, and immunohistochemistry (IHC) techniques.

RESULTS

Exosomal CCT3 was identified as a potential biomarker with significant impact. The expression of CCT3 in different tumor stages and normal tissues adjacent to the tumors (NATs) was validated using qPCR, western blotting, and IHC. CCT3 expression significantly increased the number of activated natural killer cells in HCC, as confirmed by qPCR and IHC. CCT3 expression significantly increases the expression of immune checkpoints in HCC. HCC-derived exosomes significantly increase the enrichment of CCT3.

CONCLUSION

Exosomal CCT3 is a biomarker for diagnosis and ICB therapy of HCC via MYC pathway activation and immune infiltration.

CD8+ T Cell Subsets as Biomarkers for Predicting Checkpoint Therapy Outcomes in Cancer Immunotherapy

The advent of immune checkpoint blockade (ICB) has transformed cancer immunotherapy, enabling remarkable long-term outcomes and improved survival, particularly with ICB combination treatments. However, clinical benefits remain confined to a subset of patients, and life-threatening immune-related adverse effects pose a significant challenge. This limited efficacy is attributed to cancer heterogeneity, which is mediated by ligand-receptor interactions, exosomes, secreted factors, and key transcription factors. Oncogenic regulators like E2F1 and MYC drive metastatic tumor environments and intertwine with immunoregulatory pathways, impairing T cell function and reducing immunotherapy effectiveness. To address these challenges, FDA-approved biomarkers, such as tumor mutational burden (TMB) and programmed cell death-ligand 1 (PD-L1) expression, help to identify patients most likely to benefit from ICB. Yet, current biomarkers have limitations, making treatment decisions difficult. Recently, T cells-the primary target of ICB-have emerged as promising biomarkers. This review explores the relationship between cancer drivers and immune response, and emphasizes the role of CD8+ T cells in predicting and monitoring ICB efficacy. Tumor-infiltrating CD8+ T cells correlate with positive clinical outcomes in many cancers, yet obtaining tumor tissue remains complex, limiting its practical use. Conversely, circulating T cell subsets are more accessible and have shown promise as predictive biomarkers. Specifically, memory and progenitor exhausted T cells are associated with favorable immunotherapy responses, while terminally exhausted T cells negatively correlate with ICB efficacy. Ultimately, combining biomarkers enhances predictive accuracy, as demonstrated by integrating TMB/PD-L1 expression with CD8+ T cell frequency. Computational models incorporating cancer and immune signatures could further refine patient stratification, advancing personalized immunotherapy.

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.

PD-L1 importance in malignancies comprehensive insights into the role of PD-L1 in malignancies: from molecular mechanisms to therapeutic opportunities

The phenomenon of upregulated programmed death-ligand 1 (PD-L1) expression is common in numerous human malignancies. The overexpression of PD-L1 significantly contributes to immune evasion because its interaction with the PD-1 receptor on activated T lymphocytes impairs anti-tumour immunity by neutralizing T cell stimulatory signals. Furthermore, beyond its immunological interface, PD-L1 possesses intrinsic capabilities that directly modulate oncogenic processes, fostering cancer cell proliferation and survival. This dual function of PD-L1 challenges the efficacy of immune checkpoint inhibitors and highlights its possible application as a direct target for therapy. Recent discoveries concerning the cancer cell-intrinsic signalling pathways of PD-L1 have significantly enhanced our understanding of the pathological implications linked to its tumour-specific expression. These entail the orchestration of tumour proliferation and viability, maintenance of cancer stem cell-like phenotypes, modulation of immune responses, as well as impacts on DNA repair mechanisms and transcriptional regulation. This review aims to deliver an exhaustive synthesis of PD-L1's molecular underpinnings alongside its clinical implications in a spectrum of cancers, spanning both solid neoplasms and haematological disorders. It underscores the necessity for an integrated understanding of PD-L1 in further refining therapeutic strategies and improving patient outcomes.

Recurrent Composite Markers of Cell Types and States

Biological function is mediated by the hierarchical organization of cell types and states within tissue ecosystems. Identifying interpretable composite marker sets that both define and distinguish hierarchical cell identities is essential for decoding biological complexity, yet remains a major challenge. Here, we present RECOMBINE, an algorithm that identifies recurrent composite marker sets to define hierarchical cell identities. Validation using both simulated and biological datasets demonstrates that RECOMBINE achieves higher accuracy in identifying discriminative markers compared to existing approaches, including differential gene expression analysis. When applied to single-cell data and validated with spatial transcriptomics data from the mouse visual cortex, RECOMBINE identified key cell type markers and generated a robust gene panel for targeted spatial profiling. It also uncovered markers of CD8+; T cell states, including GZMK+;HAVCR2-; effector memory cells associated with anti-PD-1 therapy response, and revealed a rare intestinal subpopulation with composite markers in mice. Finally, using data from the Tabula Sapiens project, RECOMBINE identified composite marker sets across a broad range of human tissues. Together, these results highlight RECOMBINE as a robust, data-driven framework for optimized marker selection, enabling the discovery and validation of hierarchical cell identities across diverse tissue contexts.

Hafnium Metal-Organic Framework-Based Glutamine Metabolism Disruptor For Potentiating Radio-Immunotherapy in MYC-Amplified Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) with MYC oncogene amplification remains a serious challenge in clinical practice. Recent advances in comprehensive treatment strategies, particularly the combination of radiotherapy and immunotherapy, offer new hope. To further improve efficacy while lowering radiation doses, nanopharmaceuticals based on high-Z elements have been extensively studied in radio-immunotherapy. In this work, a hafnium-based metal-organic framework (Hf-MOF), UiO-66-Hf(2OH)-CB-839/BSO@HA (UiO-66-Hf(2OH)-C/B@HA), was designed to codeliver telaglenastat (CB-839) and buthionine sulfoximine (BSO), which synergistically inhibited glutamine metabolism and alleviated tumor hypoxia. Further modification with hyaluronic acid (HA) enhanced tumor targeting, ultimately strengthening the efficacy of radiotherapy in MYC-amplified HCC. Beyond increasing reactive oxygen species (ROS) generation, promoting DNA damage, and inducing tumor apoptosis, more importantly, UiO66-Hf(2OH)-C/B@HA triggered immunogenic cell death (ICD), driving the antitumor immune response. Combination with immune checkpoint blockade (ICB) further enhanced the efficacy, accompanied by increased infiltration of T cells with high granzyme B expression (GZMB+ T cells) within the tumor microenvironment (TME). In the orthotopic HCC model, established with MYC-amplified tumor cells, intravenous administration of UiO66-Hf(2OH)-C/B@HA significantly potentiated the efficacy of radio-immunotherapy, resulting in superior tumor regression. In summary, our study provides insights into the design of Hf-MOF for radio-immunotherapy and proposes a promising therapeutic approach for MYC-amplified HCC.

CBL0137 and NKG2A blockade: a novel immuno-oncology combination therapy for Myc-overexpressing triple-negative breast cancers

The MYC proto-oncogene is upregulated in >60% of triple-negative breast cancers (TNBCs), it can directly promote tumor cell proliferation, and its overexpression negatively regulates anti-tumor immune responses. For all these reasons, MYC has long been considered as a compelling therapeutic target. However, pharmacological inhibition of MYC function has proven difficult due to a lack of a drug-binding pocket. Here, we demonstrate that the potent abrogation of MYC gene transcription by CBL0137 induces immunogenic cell death and reduces proliferation in MYC-high but not in MYC-low TNBC in vitro. CBL0137 also significantly inhibited the in vivo growth of primary tumors in a human MYC-high TNBC xenograft model (MDA-MB-231). Moreover, CBL0137 inhibited the tumor growth of highly aggressive mouse 4T1.2 syngeneic TNBC model in immunocompetent mice by inhibiting the MYC pathway and inducing Type I interferon responses. Immune profiling of CBL0137-treated mice revealed significantly enhanced tumor-specific immune responses and increased proportions of tumor infiltrating effector CD8+ T cells, CD4+ T cells, and NK cells. CBL0137-induced immune activation also resulted in increased exhaustion of immune effector cells. In particular, NKG2A up-regulation on activated effector cells and of its ligand Qa-1b on tumors in vivo was identified as a possible immune evasive mechanism. Indeed, NKG2A blockade synergized with CBL0137 significantly inhibiting the in vivo growth of 4T1.2 tumors. Collectively, our findings provide the rationale supporting the exploitation of CBL0137-induced anti-tumor immunity in combination with NKG2A blockade to improve the treatment of TNBC expressing high levels of MYC.

PD-L1 siRNA incorporation into a cationic liposomal tumor mRNA vaccine enhances cytotoxic T cell activation and prevents immune evasion

Engaging antigen-presenting cells and T lymphocytes is essential for invigorating the immune system's response to cancer. Nonetheless, challenges such as the low immunogenicity of tumor antigens, the genetic heterogeneity of tumor cells, and the elevated expression of immune checkpoint molecules frequently result in resistance to immunotherapy or enable immune evasion by tumors. To overcome this resistance, we developed a therapeutic tumor vaccine employing cationic liposomes to encapsulate MC38 total RNA alongside PD-L1 siRNA (siPD-L1). The encapsulated total RNA, enriched with tumor mRNA, effectively transduces dendritic cells (DCs), thereby enhancing antigen presentation. The incorporation of siPD-L1 specifically targets and diminishes PD-L1 expression on both DCs and tumor cells, synergistically amplifying the cytotoxic capabilities of CD8+ T cells. Furthermore, cationic liposomes play dual roles as carriers crucial for preserving the integrity of nucleic acids for antigen translation and as inhibitors of autophagy-a process essential for both promoting antigen cross-presentation and revitalizing MHC-I expression on tumor cells, thereby increasing their immunogenicity. This cationic liposomal vaccine represents a promising strategy in cancer immunotherapy, launching a multidimensional offensive against tumor cells that enhances cytotoxic T lymphocyte (CTL) activation and prevents tumor immune evasion.

Immunogenomic cancer evolution: A framework to understand cancer immunosuppression

The process of tumor development involves tumor cells eluding detection and suppression of immune responses, which can cause decreased tumor cell antigenicity, expression of immunosuppressive molecules, and immunosuppressive cell recruitment to the tumor microenvironment (TME). Immunologically and genomically integrated analysis (immunogenomic analysis) of patient specimens has revealed that oncogenic aberrant signaling is involved in both carcinogenesis and immune evasion. In noninflamed cancers such as epidermal growth factor receptor (EGFR)-mutated lung cancers, genetic abnormalities in cancer cells contribute to the formation of an immunosuppressive TME by recruiting immunosuppressive cells, which cannot be fully explained by the cancer immunoediting hypothesis. This review summarizes the latest findings regarding the links between cancer genetic abnormalities and immunosuppression causing clinical resistance to immunotherapy. We propose the concepts of immunogenomic cancer evolution, in which cancer cell genomic evolution shapes the immunosuppressive TME, and immunogenomic precision medicine, in which cancer immunotherapy can be combined with molecularly targeted reagents that modulate the immunosuppressive TME.

Pancreatic cancer: failures and hopes-a review of new promising treatment approaches

Pancreatic cancer is a challenging disease with limited treatment options and a high mortality rate. Just few therapy advances have been made in recent years. Tumor microenvironment, immunosuppressive features and mutational status represent important obstacles in the improvement of survival outcomes. Up to now, first-line therapy did achieve a median overall survival of less than 12 months and this discouraging data lead clinicians all over the world to focus their efforts on various fields of investigation: 1) sequential cycling of different systemic therapy in order to overcome mechanisms of resistance; 2) discovery of new predictive bio-markers, in order to target specific patient population; 3) combination treatment, in order to modulate the tumor microenvironment of pancreatic cancer; 4) new modalities of the delivery of drugs in order to pass the physical barrier of desmoplasia and tumor stroma. This review shows future directions of treatment strategies in advanced pancreatic cancer through a deep analysis of these recent macro areas of research.

Immune modulation in solid tumors: a phase 1b study of RO6870810 (BET inhibitor) and atezolizumab (PD-L1 inhibitor)

PURPOSE

Bromodomain and extra-terminal domain (BET) inhibitors (BETi) have demonstrated epigenetic modulation capabilities, specifically in transcriptional repression of oncogenic pathways. Preclinical assays suggest that BETi potentially attenuates the PD1/PD-L1 immune checkpoint axis, supporting its combination with immunomodulatory agents.

PATIENTS AND METHODS

A Phase 1b clinical trial was conducted to elucidate the pharmacokinetic and pharmacodynamic profiles of the BET inhibitor RO6870810 as monotherapy and in combination with the PD-L1 antagonist atezolizumab in patients with advanced ovarian carcinomas and triple-negative breast cancer (TNBC). Endpoints included maximum tolerated dosages, adverse event profiling, pharmacokinetic evaluations, and antitumor activity. Pharmacodynamic and immunomodulatory effects were assessed in tumor tissue (by immunohistochemistry and RNA-seq) and in peripheral blood (by flow cytometry and cytokine analysis).

RESULTS

The study was terminated prematurely due to a pronounced incidence of immune-related adverse effects in patients receiving combination of RO6870810 and atezolizumab. Antitumor activity was limited to 2 patients (5.6%) showing partial response. Although target engagement was confirmed by established BETi pharmacodynamic markers in both blood and tumor samples, BETi failed to markedly decrease tumor PD-L1 expression and had a suppressive effect on antitumor immunity. Immune effector activation in tumor tissue was solely observed with the atezolizumab combination, aligning with this checkpoint inhibitor's recognized biological effects.

CONCLUSIONS

The combination of BET inhibitor RO6870810 with the checkpoint inhibitor atezolizumab presents an unfavorable risk-benefit profile for ovarian cancer and TNBC (triple-negative breast cancer) patients due to the increased risk of augmented or exaggerated immune reactions, without evidence for synergistic antitumor effects.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT03292172; Registration Date: 2017-09-25.

Recent advances in the mechanisms of PD-L1 expression in gastric cancer: a review

In the progression of gastric cancer (GC), various cell types in the tumor microenvironment (TME) exhibit upregulated expression of programmed death ligand 1 (PD-L1), leading to impaired T-cell function and evasion of immune surveillance. Infection with H. pylori and EBV leads to increased PD-L1 expression in various cell types within TME, resulting in immune suppression and facilitating immune escape of GC cells. In the TME, mesenchymal stem cells (MSCs), M1-like tumor-associated macrophages (MI-like TAM), and myeloid-derived suppressor cells (MDSCs) contribute to the upregulation of PD-L1 expression in GC cells. Conversely, mast cells, M2-like tumor-associated macrophages (M2-like TAM), and tumor-associated neutrophils (TANs) exhibit elevated levels of PD-L1 expression in response to the influence of GC cells. Together, these factors collectively contribute to the upregulation of PD-L1 expression in GC. This review aims to provide a comprehensive summary of the cellular expression patterns of PD-L1 in GC and the underlying molecular mechanisms. Understanding the complex regulatory pathways governing PD-L1 expression may offer novel insights for the development of effective immunotherapeutic interventions.

Inflammation and cancer: molecular mechanisms and clinical consequences

Inflammation, a hallmark of cancer, has been associated with tumor progression, transition into malignant phenotype and efficacy of anticancer treatments in cancer. It affects all stages of cancer, from the initiation of carcinogenesis to metastasis. Chronic inflammation induces immunosup-pression, providing an environment conducive to carcinogenesis, whereas acute inflammation induces an antitumor immune response, leading to tumor suppression. Solid tumors have an inflammatory tumor microenvironment (TME) containing cancer cells, immune cells, stromal cells, and soluble molecules, which plays a key role in tumor progression and therapy response. Both cancer cells and stromal cells in the TME are highly plastic and constantly change their phenotypic and functional properties. Cancer-associated inflammation, the majority of which consists of innate immune cells, plays an important role in cancer cell plasticity, cancer progression and the development of anticancer drug resistance. Today, with the combined used of advanced technologies, such as single-cell RNA sequencing and spatial molecular imaging analysis, the pathways linking chronic inflammation to cancer have been largely elucidated. In this review article, we highlighted the molecular and cellular mechanisms involved in cancer-associated inflammation and its effects on cancer progression and treatment response. We also comprehensively review the mechanisms linking chronic inflammation to cancer in the setting of GI cancers.

c-Myc-targeted therapy in breast cancer: A review of fundamentals and pharmacological Insights

The oncoprotein c-Myc is expressed in all breast cancer subtypes, but its expression is higher in triple-negative breast cancer (TNBC) compared to estrogen receptor (ER+), progesterone receptor (PR+), or human epidermal growth factor receptor 2 (HER2+) positive tumors. The c-Myc gene is crucial for tumor progression and therapy resistance, impacting cell proliferation, differentiation, senescence, angiogenesis, immune evasion, metabolism, invasion, autophagy, apoptosis, chromosomal instability, and protein biosynthesis. Targeting c-Myc has emerged as a potential therapeutic strategy for TNBC, a highly aggressive and deadly breast cancer form. This review highlights c-Myc as a pharmacological target, discussing antitumor compounds in preclinical and clinical trials. Notably, the c-Myc inhibitor OMO-103 has shown promise in a Phase II clinical trial for advanced cancer patients. Further research is needed to develop new drugs targeting this gene, protein, or its pathways, and additional studies on cancer patients are encouraged.

Nanoparticle-Mediated Toll-Like Receptor Activation and Dual Immune Checkpoint Downregulation for Potent Cancer Immunotherapy

Dual blockade of CD47 and PD-L1 immune checkpoints has shown potential in cancer treatment, but its clinical application is hindered by the on-target off-tumor immunotoxicities of monoclonal antibodies. Herein, we report a core-shell nanoparticle, PPA/HG, comprising polyinosinic: polycytidylic acid (PPA) in the core and a cholesterol-conjugated prodrug of 3-(hydroxyolinoyl)glycine (HG) on the shell, for potent cancer immunotherapy. PPA/HG shows a long half-life in the bloodstream to efficiently accumulate in tumors, where PPA/HG rapidly releases HG and PPA. HG inhibits the histone lysine demethylase 3A/c-Myc transduction for effective CD47 and PD-L1 downregulation in cancer cells while PPA activates toll-like receptor 3 in dendritic cells and tumor-associated macrophages to promote dendritic cell maturation and macrophage repolarization. PPA/HG promotes the infiltration and activation of effector T lymphocytes, meanwhile decreasing the population of immunosuppressive regulatory T cells. Systemic administration of PPA/HG significantly inhibits the progression of orthotopic triple-negative breast cancer and pancreatic ductal adenocarcinoma with minimal side effects.

ZEB1 transcription factor induces tumor cell PD-L1 expression in melanoma

Tumor cells can evade antitumor immune response by expressing the PD-L1 ligand, leading to the inhibition of PD-1-expressing T lymphocytes. The mechanisms that regulate PD-L1 expression in cancer cells are imperfectly characterized. The transcription factor ZEB1, a major regulator of phenotype switching in melanoma cells, was shown to promote immune escape in melanoma by repressing T cell infiltration. Using inducible models of phenotype switching and ZEB1 gain/loss-of-function melanoma, we show that ZEB1 binds to the CD274 (PD-L1) promoter, directly enhancing PD-L1 mRNA transcription and its expression at the cell membrane. Furthermore, using single-cell spatial analyses on human primary melanoma samples, we demonstrate the correlation of ZEB1 and PD-L1 expression in tumor cells. Overall, these data identify ZEB1-mediated regulation of PD-L1 tumor expression as a mechanism that could contribute to immune escape in melanoma.

Promotion of triple negative breast cancer immunotherapy by combining bioactive radicals with immune checkpoint blockade

Although immunotherapy has revolutionized clinical cancer treatment, the efficacy is limited due to the lack of tumor-associated antigens (TAAs) and the presence of compensatory immune checkpoints. To overcome the deficiency, a nano-system loaded with ozone and CD47 inhibitor RRx-001 is designed and synthesized. Upon irradiation, reactive oxygen species (ROS) generated from ozone reacts with nitric oxide (NO) metabolized from RRx-001 to form reactive nitrogen species (RNS), which presents a much stronger cell-killing ability than ROS. Molecular mechanism studies further reveal that RNS induce extensive immunogenic cell death (ICD). The released TAAs promote infiltration of cytotoxic T lymphocytes, which provides the basis for immune checkpoint blockade (ICB) therapy. Meanwhile, RRx-001 carried by the nanoparticles and the produced radicals repolarize M2-type tumor-associated macrophages (TAMs) into the anti-tumor M1-type, consequently reversing the immunosuppressive tumor microenvironment (TME). In a xenograft triple-negative breast cancer (TNBC) animal model, O3-001@lipo (liposome enwrapping O3 and RRx-001) plus irradiation shows a significant anti-tumor efficacy by improving cytotoxic lymphocyte infiltration and regulating immunosuppressive TME. In summary, the O3-001@lipo nano-system triggered by irradiation potently improves the efficacy of immunotherapy by introducing strong cytotoxic RNS, which not only enriches the toolbox of ICD inducer but also provides a strategy of treatment for immune deficient tumor. STATEMENT OF SIGNIFICANCE: This study introduces a nano-system that leverages ozone and RRx-001 in the presence of X-ray irradiation to generate reactive nitrogen species, enhancing immunogenic cell death and promoting T-lymphocyte infiltration in triple-negative breast cancer, addressing a significant unmet need in the field. The scientific contribution is the development of a clinically translatable nano-system that not only induces ICD but also reshapes the tumor microenvironment, which is expected to have a profound impact on the readership in pharmaceutics, material science, and nano-bio interaction, particularly for those interested in advanced immune therapy approaches.

circCCNY enhances lenvatinib sensitivity and suppresses immune evasion in hepatocellular carcinoma by serving as a scaffold for SMURF1 mediated HSP60 degradation

Lenvatinib is the standard first-line therapy for advanced hepatocellular carcinoma (HCC), but drug resistance significantly hampers its efficacy. Increasing evidence has shown that circular RNAs (circRNAs) play critical roles in HCC pathogenesis. However, the underlying mechanisms of lenvatinib sensitivity regulated by circRNAs remain largely unclear. The present study aims to identify circRNAs involved in lenvatinib resistance, as well as to elucidate the underlying mechanisms. High-throughput sequencing revealed that hsa_circ_0000235 (circCCNY) was downregulated in matched HCC tumor tissues and lenvatinib-resistant cells. Both in vitro and in vivo experiments revealed that downregulation of circCCNY could induce lenvatinib resistance in HCC cells. Subsequently, RNA pull-down, mass spectrometry, and RNA immunoprecipitation techniques were employed to investigate the interactions between circCCNY, HSP60, and the E3 ubiquitin ligase SMURF1. Briefly, circCCNY bounds to HSP60, subsequently leading to HSP60 ubiquitination and degradation through its interaction with the E3 ubiquitin ligase SMURF1. As a result, HSP60 degradation released Raf kinase inhibitor protein (RKIP), leading to the inactivation of the MAPK signaling pathway, and subsequently enhanced the anti-tumor effect of lenvatinib against HCC. Moreover, we also demonstrated that circCCNY could enhance CD8+ T-cell infiltration and suppress immune evasion through inhibiting the MAPK/c-Myc/PD-L1 signaling pathway. Our findings revealed that circCCNY enhances HCC sensitivity to lenvatinib and suppresses immune evasion by inhibiting the MAPK signaling pathway in HCC. This suggests that circCCNY could serve as a promising therapeutic target in HCC treatment and a potential biomarker for predicting HCC sensitivity to lenvatinib.

The pathogenesis of B-cell non-hodgkin lymphoma associated with HBV (hepatitis B virus) infection is regulated by c-Myc/PD-L1 signaling pathway

Background

HBV is closely associated with the incidence of B-NHL (B-cell non-hodgkin lymphoma). This project intends to establish HBV infection-induced B-NHL cells and animal models to clarify the mutual mechanism of HBV infection and B-NHL pathogenesis.

Methods

The relationship between HBV and B-NHL was studied based on the HBV infection model, which included CTC cells and HBV transgenic mice. Moreover, differential expression analysis of transcriptome profiling was performed to confirm the mechanism.

Results

The HBsAg expression and HBV-DNA could be found in tumor tissues of HBV group, but negative in the control group. Moreover, there were clearly differences between the two groups in the transcriptome of tumor tissues and CTC. HBsAg significantly promoted lymphocytes associated with c-Myc and PD-L1.

Conclusion

The promoted effect induced by HBsAg in lymphocytes was associated with PD-L1 mediated by c-Myc.

Cholesterol suppresses AMFR-mediated PDL1 ubiquitination and degradation in HCC

The degradation of proteasomes or lysosomes is emerging as a principal determinant of programmed death ligand 1 (PDL1) expression, which affects the efficacy of immunotherapy in various malignancies. Intracellular cholesterol plays a central role in maintaining the expression of membrane receptors; however, the specific effect of cholesterol on PDL1 expression in cancer cells remains poorly understood. Cholesterol starvation and stimulation were used to modulate the cellular cholesterol levels. Immunohistochemistry and western blotting were used to analyze the protein levels in the samples and cells. Quantitative real-time PCR, co-immunoprecipitation, and confocal co-localization assays were used for mechanistic investigation. A xenograft tumor model was constructed to verify these results in vivo. Our results showed that cholesterol suppressed the ubiquitination and degradation of PDL1 in hepatocellular carcinoma (HCC) cells. Further mechanistic studies revealed that the autocrine motility factor receptor (AMFR) is an E3 ligase that mediated the ubiquitination and degradation of PDL1, which was regulated by the cholesterol/p38 mitogenic activated protein kinase axis. Moreover, lowering cholesterol levels using statins improved the efficacy of programmed death 1 (PD1) inhibition in vivo. Our findings indicate that cholesterol serves as a signal to inhibit AMFR-mediated ubiquitination and degradation of PDL1 and suggest that lowering cholesterol by statins may be a promising combination strategy to improve the efficiency of PD1 inhibition in HCC.

Precision models in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) represents a global health challenge, and ranks among one of the most prevalent and deadliest cancers worldwide. Therapeutic advances have expanded the treatment armamentarium for patients with advanced HCC, but obstacles remain. Precision oncology, which aims to match specific therapies to patients who have tumours with particular features, holds great promise. However, its implementation has been hindered by the existence of numerous 'HCC influencers' that contribute to the high inter-patient heterogeneity. HCC influencers include tumour-related characteristics, such as genetic alterations, immune infiltration, stromal composition and aetiology, and patient-specific factors, such as sex, age, germline variants and the microbiome. This Review delves into the intricate world of HCC, describing the most innovative model systems that can be harnessed to identify precision and/or personalized therapies. We provide examples of how different models have been used to nominate candidate biomarkers, their limitations and strategies to optimize such models. We also highlight the importance of reproducing distinct HCC influencers in a flexible and modular way, with the aim of dissecting their relative contribution to therapy response. Next-generation HCC models will pave the way for faster discovery of precision therapies for patients with advanced HCC.

CD47 as a potential predictive biomarker in colorectal cancer

In this week's Journal for ImmunoTherapy for Cancer, Arai and colleagues analyzed next-generation sequencing data for DNA and RNA from 14,287 patients with colorectal cancer (CRC) categorized by median CD47 expression level, and showed that CD47, a key component of innate immunity in deflecting phagocytosis, is associated with molecular subtypes of CRC, cell damage-associated molecular pattern-related genes, major oncogenic pathways, and adaptive immune checkpoint genes. Taken together, they concluded that CD47 expression is associated with activation of oncogenic pathways and an immune-engaged tumor microenvironment. Clinical outcomes data also demonstrated that high CD47 is associated with prolonged survival in patients treated with antiangiogenic and checkpoint inhibitor therapy. Biomarker studies such as this will enable broader application of immuno-oncology to patients with CRC and other malignancies.

Cancer stem cells and niches: challenges in immunotherapy resistance

Cancer stem cells (CSCs) are central to tumor progression, metastasis, immune evasion, and therapeutic resistance. Characterized by remarkable self-renewal and adaptability, CSCs can transition dynamically between stem-like and differentiated states in response to external stimuli, a process termed "CSC plasticity." This adaptability underpins their resilience to therapies, including immune checkpoint inhibitors and adoptive cell therapies (ACT). Beyond intrinsic properties, CSCs reside in a specialized microenvironment-the CSC niche-which provides immune-privileged protection, sustains their stemness, and fosters immune suppression. This review highlights the critical role of CSCs and their niche in driving immunotherapy resistance, emphasizing the need for integrative approaches to overcome these challenges.

Genome-wide CRISPR screening identifies PHF8 as an effective therapeutic target for KRAS- or BRAF-mutant colorectal cancers

BACKGROUND

Mutations in KRAS and BRAF genes are prevalent in colorectal cancer (CRC), which strikingly promote tumorigenesis and lead to poor response to a variety of treatments including immunotherapy by activating the MAPK/ERK pathway. Thus, there is an urgent need to discover effective therapeutic targets and strategies.

METHODS

CRISPR-Cas9 lentiviral knockout library was used to screen the suppressors of anti-PD1 immunotherapy. Bioinformatic analysis was used to analyze the correlation between PHF8 expression and immune indicators in CRC. In vitro and in vivo experiments were utilized to determine the effects of PHF8 on the immune indexes and malignant phenotypes of CRC cells. qRT-PCR, western blotting, immunohistochemical (IHC) staining, and chromatin immunoprecipitation (ChIP)-qPCR assays were used to determine the regulatory effects of PHF8 on PD-L1, KRAS, BRAF, and c-Myc and the regulatory effect c-Myc/miR-22-3p signaling axis on PHF8 expression in CRC cells.

RESULTS

This study identified histone lysine demethylase PHF8 as a negative regulator for the efficacy of anti-PD1 therapy and found that it was highly expressed in CRCs and strongly associated with poor patient survival. Functional studies showed that PHF8 played an oncogenic role in KRAS- or BRAF-mutant CRC cells, but not in wild-type ones. Mechanistically, PHF8 up-regulated the expression of PD-L1, KRAS, BRAF, and c-Myc by increasing the levels of transcriptional activation marks H3K4me3 and H3K27ac and decreasing the levels of transcriptional repression mark H3K9me2 within their promoter regions, promoting immune escape and tumor progression. Besides, our data also demonstrated that PHF8 was up-regulated by the c-Myc/miR-22-3p signaling axis to form a positive feedback loop. Targeting PHF8 substantially improved the efficacy of anti-PD1 therapy and inhibited the malignant phenotypes of KRAS- or BRAF-mutant CRC cells.

CONCLUSION

Our data demonstrate that PHF8 may be an effective therapeutic target for KRAS- or BRAF-mutant CRCs.

Rationally Engineered Bispecific Nanoimmunoblocker Restores Anticancer Immunity via Dual Immune Checkpoint Blockade

Immune checkpoint blockade (ICB) therapy has revolutionized cancer treatment. However, the outcomes of mainstay antibody inhibitors against solid tumors remain poor, facing tremendous challenges including manufacturing complexities, serious toxicities, and crosstalk among multiple checkpoints. Herein, we present a bispecific molecularly imprinted nanoimmunoblocker (bsMINIB) designed to boost potent antitumor immunity via synchronously blocking innate and adaptive immune checkpoints. Two epitopes for PD-L1 and SIRPα are selected as templates through structural analysis, and thereafter, bsMINIB capable of bridging tumor cells and macrophages is rationally engineered via an advanced imprinting approach. The bsMINIB exhibits high affinity and specificity toward PD-L1 on solid tumor cells and SIRPα on macrophages, allowing effective disruption of both PD-L1/PD-1 and CD47/SIRPα signaling. These signal disruptions restore macrophage-mediated tumor phagocytosis, promote tumor-associated antigen presentation, and reinvigorate T cell-mediated tumor killing. Using refractory triple-negative breast cancer as a solid tumor model, the bsMINIB demonstrates extended retention at the tumor site, amplified infiltration of active T cells, and reactivated antitumor macrophages, thereby effectively inhibiting tumor growth. This biomimetic nanoimmunoblocker not only presents an effective multipronged ICB therapeutic against solid tumors but also showcases a compelling paradigm for the rational engineering of bispecific nanoplatforms for synergistic immunotherapy through molecular imprinting.

A Cure for Type 1 Diabetes: Are We There Yet?

Type 1 diabetes (T1D) affects over 2 million people in the United States and has no known cure. The discovery and first use of insulin in humans 102 years ago marked a revolutionary course of treatment for the disease, and although the formulations and delivery systems have advanced, insulin administration remains the standard of care today. While improved treatment options represent notable progress in T1D management, finding a functional cure for the disease remains the ultimate goal. Approaches to curing T1D have historically focused on blunting the autoimmune response, although sustained effects of immune modulation have proven elusive. Islet transplant therapies have also proven effective, although a lack of available donor tissue and the need for immunosuppression to prevent both host-graft rejection and the autoimmune response have reserved such treatments for those who already require immunosuppressive regimens for other reasons or undergo severe hypoglycemic events in conjunction with hypoglycemic unawareness. With the advent of human stem cell research, the focus has shifted toward generating an abundance of allogeneic, functional beta-like cells that can be transplanted into the patients. Immunoisolation devices have also shown some promise as a method of preventing immune rejection and the autoimmune destruction of transplanted cells. Finally, advances in new immune therapies, if used in the early stages of T1D progression, have proven to delay the onset of diabetes. Stem cell-based therapies are a promising approach to curing T1D. The ongoing clinical trials show some success, although they currently require immunosuppressant agents. Encapsulation devices provide a method of immunoisolation that does not require immunosuppression; however, the devices tested thus far eventually lead to cell death and fibrotic tissue growth. Substantial research efforts are underway to develop new approaches to protect the stem cell-derived beta cells upon transplantation.

Chimeric Peptide Functionalized Immunostimulant to Orchestrate Photodynamic Immunotherapeutic Effect by PD-L1 Deglycosylation and CD47 Inhibition

Breast cancer utilizes diverse immunosuppressive mechanisms to evade immune surveillance, thereby impairing immunotherapeutic effects. In this work, a chimeric peptide functionalized immunostimulant (designated as aGlyR) is fabricated to boost photodynamic immunotherapy through PD-L1 deglycosylation and CD47 inhibition. The photosensitizer protoporphyrin IX (PpIX) is conjugated to a PD-L1 deglycosylation peptide via a hydrophilic PEG8 linker, yielding the chimeric peptide Fmoc-K(PpIX)-PEG8-GFTATPPAPDSPQEP. This chimeric peptide could self-assemble into nanomicelles capable of encapsulating the CD47 inhibitor RRx-001, generating the multifunctional photodynamic immunostimulant aGlyR. In vitro and in vivo results indicate that the photodynamic therapy (PDT) of aGlyR could disrupt breast cancer cells and trigger immunogenic cell death (ICD), leading to the release of tumor-associated antigens (TAAs) and the activation of immunological cascades. Additionally, the chimeric peptide component of aGlyR results in the deglycosylation and degradation of PD-L1, which restores T cell-mediated immune activity. Concurrently, the release of RRx-001 blocks the CD47 pathway, disrupting the antiphagocytic signaling of breast cancer cells and activating innate immune responses. This synergistic immunomodulatory approach effectively reverses the complex immunosuppressive factors, significantly enhancing the immunotherapeutic effects of conventional treatments.

Resetting the Hsc70-mediated lysosomal degradation of PD-L1 via a supramolecular meso peptide for the restoration of acquired anti-tumor T cell immunity

The reduction of cellular PD-L1 abundance through lysosomal degradation is recognized as essential for effective and sustained targeting of PD-L1-dependent immune evasion in cancer. While Hsc70 can interact with PD-L1 to promote its lysosomal degradation, the overexpression of CMTM6 competitively inhibits this interaction, leading to the blockade of PD-L1 lysosomal degradation. To overcome this issue, a meso chimeric peptide PEPPDL1 was designed to specifically bind the PD-1 binding domain of PD-L1 instead of the Hsc70/CMTM6 binding domain, while also binding to Hsc70 to facilitate the dragging of PD-L1 into Hsc70-mediated chaperone-mediated autophagy (CMA), thereby achieving lysosomal degradation. In order to enable internalization into tumor cells, supramolecular engineering techniques were employed through terminal modification involving sulfydryl and monovalent gold ion (Au(I)), both facilitating self-assembly of modified PEPPDL1 into supramolecular nanospheres termed CTAC-PDL1 driven by aurophilic interaction. Furthermore, based on bioinformatics analysis of mRNA expression data from 30 types of tumors obtained from TCGA database, malignant melanoma was identified as the most suitable indication for CTAC-PDL1 due to its specific characteristics of tumor immune. As expected, CTAC-PDL1 effectively reactivated Hsc70-mediated lysosomal degradation of PD-L1 and consequently restored anti-tumor T cell immunity in a B16F10-derived mouse model of malignant melanoma while maintaining a favorable safety profile. Overall, this work not only presents an alternative approach for targeting PD-L1-dependent cancer immune evasion, but also provides a modularized strategy for discovering specific regulators for target proteins in various diseases.

Inflammation and Immunity in Liver Neoplasms: Implications for Future Therapeutic Strategies

Over the past two decades, the "hallmarks of cancer" have revolutionized cancer research and highlighted the crucial roles of inflammation and immunity. Protumorigenic inflammation promotes cancer development along with inhibition of antitumor immunity, shaping the tumor microenvironment (TME) toward a tumor-permissive state and further enhancing the malignant potential of cancer cells. This immunosuppressive TME allows tumors to evade immunosurveillance. Thus, understanding the complex interplay between tumors and the immune system within the TME has become pivotal, especially with the advent of immunotherapy. Although immunotherapy has achieved notable success in many malignancies, primary liver cancer, particularly hepatocellular carcinoma, presents unique challenges. The hepatic immunosuppressive environment poses obstacles to the effectiveness of immunotherapy, along with high mortality rates and limited treatment options for patients with liver cancer. In this review, we discuss current understanding of the complex immune-mediated mechanisms underlying liver neoplasms, focusing on hepatocellular carcinoma and liver metastases. We describe the molecular and cellular heterogeneity within the TME, highlighting how this presents unique challenges and opportunities for immunotherapy in liver cancers. By unraveling the immune landscape of liver neoplasms, this review aims to contribute to the development of more effective therapeutic interventions, ultimately improving clinical outcomes for patients with liver cancer.

Overexpression of ornithine decarboxylase 1 mediates the immune-deserted microenvironment and poor prognosis in diffuse large B-cell lymphoma

Background

Previous researches mainly focused on whether cancer stem cells exist in diffuse large B-cell lymphoma (DLBCL). However, subgroups with dismal prognosis and stem cell-like characteristics have been overlooked.

Methods

Using large scale data (n = 2133), we conducted machine learning algorithms to identify a high risk DLBCL subgroup with stem cell-like features, and then investigated the potential mechanisms in shaping this subgroup using transcriptome, genome and single-cell RNA-seq data, and in vitro experiments.

Results

We identified a high-risk subgroup (25.6 % of DLBCL) with stem cell-like characteristics and dismal prognosis. This high-risk group (HRG) was featured by upregulation of key enzyme (ODC1) in polyamine metabolism and cold tumor microenvironment (TME), and had a poor prognosis with lower 3-year overall survival (OS) (54.3 % vs. 83.6 %, P < 0.0001) and progression-free survival (PFS) (42.8 % vs. 74.7 %, P < 0.0001) rates compared to the low-risk group. HRG also exhibited malignant proliferative phenotypes similar to Burkitt lymphoma. Patients with MYC rearrangement, double-hit, double-expressors, or complete remission might have either favorable or poor prognosis, which could be further distinguished by our risk stratification model. Genomic analysis revealed widespread copy number losses in the chemokine and interferon coding regions 8p23.1 and 9p21.3 in HRG. We identified ODC1 as a therapeutic vulnerability for HRG-DLBCL. Single-cell analysis and in vitro experiments demonstrated that ODC1 overexpression enhanced DLBCL cell proliferation and drove macrophage polarization towards the M2 phenotype. Conversely, ODC1 inhibition reduced DLBCL cell proliferation, induced cell cycle arrest and apoptosis, and promoted macrophage polarization towards the M1 phenotype. Finally, we developed a comprehensive database of DLBCL for clinical application.

Conclusions

Our study effectively advances the precise risk stratification of DLBCL and reveals that ODC1 and immune-deserted microenvironment jointly shape a group of DLBCL patients with stem cell-like features. Targeting ODC1 regulates immunotherapies in DLBCL, offering new insights for DLBCL treatment.

Ubiquitination of CD47 Regulates Innate Anti-Tumor Immune Response

In addition to adaptive immune checkpoint of PD-1/PD-L1, the innate immune checkpoint SIRPα/CD47 plays an important role in regulation of tumor immune escape. However, the mechanism of CD47 ubiquitination on tumor immune escape remains unclear. Here it is found that TRAF2 bound to the C-terminal of CD47 cytoplasmic fragment and induced its ubiquitination, leading to inhibition of CD47 autophagic degradation by disrupting its binding to LC3, which in turn inhibited macrophage phagocytosis and promoted tumor immune escape. In contrast, loss of TRAF2 facilitated CD47 autophagic degradation and inhibited tumor immune escape. Moreover, autophagy induction promoted CD47 degradation and enhanced the efficacy of CD47 antibody anti-tumor immunotherapy. These findings revealed a novel mechanism of ubiquitination of CD47 on tumor immune escape.

Formin protein DAAM1 positively regulates PD-L1 expression via mediating the JAK1/STAT1 axis in pancreatic cancer

BACKGROUND

Dishevelled-associated activator of morphogenesis1 (DAAM1) is a member of the evolutionarily conserved Formin family and plays a significant role in the malignant progression of various human cancers. This study aims to explore the clinical and biological significance of DAAM1 in pancreatic cancer.

METHODS

Multiple public datasets and an in-house cohort were utilized to assess the clinical relevance of DAAM1 in pancreatic cancer. The LinkedOmics platform was employed to perform enrichment analysis of DAAM1-associated molecular pathways in pancreatic cancer. Subsequently, a series of in vitro and in vivo experiments were conducted to evaluate the biological roles of DAAM1 in pancreatic cancer cells and its effects on intratumoral T cells.

RESULTS

DAAM1 was found to be upregulated in pancreatic cancer tissues, with higher expression levels observed in tumor cells. Additionally, high expression of DAAM1 was associated with poor prognosis. DAAM1 acted as an oncogene in pancreatic cancer, and its inhibition suppressed tumor cell proliferation, migration, and invasion, while promoted apoptosis. Furthermore, DAAM1 was involved in the JAK1/STAT1 signaling pathway and regulated PD-L1 expression in pancreatic cancer cells. The inhibition of DAAM1 also significantly reduced the exhaustion levels of CD8+ T cells.

CONCLUSION

In conclusion, DAAM1 functions as an oncogene and is immunologically implicated in pancreatic cancer, these findings suggest that DAAM1 may serve as a promising therapeutic target for the clinical management of pancreatic cancer.

CD133+PD-L1+ cancer cells confer resistance to adoptively transferred engineered macrophage-based therapy in melanoma

Adoptive transfer of genetically or nanoparticle-engineered macrophages represents a promising cell therapy modality for treatment of solid tumor. However, the therapeutic efficacy is suboptimal without achieving a complete tumor regression, and the underlying mechanism remains elusive. Here, we discover a subpopulation of cancer cells with upregulated CD133 and programmed death-ligand 1 in mouse melanoma, resistant to the phagocytosis by the transferred macrophages. Compared to the CD133-PD-L1- cancer cells, the CD133+PD-L1+ cancer cells express higher transforming growth factor-β signaling molecules to foster a resistant tumor niche, that restricts the trafficking of the transferred macrophages by stiffened extracellular matrix, and inhibits their cell-killing capability by immunosuppressive factors. The CD133+PD-L1+ cancer cells exhibit tumorigenic potential. The CD133+PD-L1+ cells are further identified in the clinically metastatic melanoma. Hyperthermia reverses the resistance of CD133+PD-L1+ cancer cells through upregulating the 'eat me' signal calreticulin, significantly improving the efficacy of adoptive macrophage therapy. Our findings demonstrate the mechanism of resistance to adoptive macrophage therapy, and provide a de novo strategy to counteract the resistance.

DLGAP5 enhances bladder cancer chemoresistance by regulating glycolysis through MYC stabilization

Rationale: Bladder cancer (BLCA), one of the most lethal urological tumors, exhibits high rates of recurrence and chemoresistance, particularly to gemcitabine (GEM). Understanding the mechanisms of GEM resistance is crucial for improving therapeutic outcomes. Our study investigates the role of DLGAP5 in promoting GEM resistance through modulation of glycolysis and MYC protein stability in BLCA cells. Methods: We utilized various BLCA cell lines and clinical tissue samples to analyze the impact of DLGAP5 on GEM resistance. Through biochemical assays, protein interaction studies, and gene expression analyses, we examined how DLGAP5 interacts with USP11 and MYC, assessed the effects on MYC deubiquitination and stability. The influence of these interactions on glycolytic activity and GEM resistance was also evaluated via mouse subcutaneous xenograft model and spontaneous BLCA model. Results: Our findings indicate that DLGAP5 enhances GEM resistance by stabilizing MYC protein via deubiquitination, a process mediated by USP11. DLGAP5 was found to facilitate the interaction between USP11 and MYC, promoting MYC-driven transcription of DLGAP5 itself, thereby creating a positive feedback loop. This loop leads to sustained MYC accumulation and increased glycolytic activity, contributing to GEM resistance in BLCA cells. Conclusion: The study highlights the critical role of DLGAP5 in regulating MYC protein stability and suggests that disrupting the DLGAP5-USP11-MYC axis may provide a novel therapeutic approach to overcome GEM resistance in BLCA. DLGAP5 represents a potential target for therapeutic intervention aimed at mitigating chemoresistance in bladder cancer BLCA.

Progress in understanding the regulatory mechanisms of immune checkpoint proteins PD-1 and PD-L1 expression

Programmed Death Protein-1 (PD-1) is a cell surface receptor that serves as a checkpoint for T cells, playing a pivotal role in regulating T-cell apoptosis. The binding of PD-1 to its ligand, Programmed Death Ligand 1 (PD-L1), inhibits anti-tumor immunity by suppressing T-cell activation signals. Indeed, the PD-1/PD-L1 pathway governs the induction and maintenance of immune tolerance within the tumor microenvironment. Consequently, the regulation of PD-1/PD-L1 immune checkpoint expression is of paramount importance. This review summarizes the mechanisms governing PD1/PD-L1 expression at various stages, including transcription, post-transcription (mRNA processing), and post-translation (protein modifications), as well as immunotherapy targeting PD1/PD-L1, aiming to further explore novel strategies for tumor immunotherapy.