Targeting immune checkpoints potentiates immunoediting and changes the dynamics of tumor evolution

P-Pev: micelle-like complexes transformed from tumor extracellular vesicles by PEG-PE for personalized therapeutic tumor vaccine

The clinical benefits of personalized therapeutic tumor vaccines are mainly challenged by the need to identify immunogenic neoantigens promptly, given the rapid pace of tumor mutations. An increasing body of literature addresses the potential of tumor-derived extracellular vesicles (TEVs) as an anti-tumor "cell-free" vaccine due to their substantial presence of neoantigens. However, their immunosuppression and limited presentation efficiency of dendritic cells (DCs) restrict their further application. Here, we have developed a novel tumor-personalized vaccine, termed P-Pev, based on remodeled TEVs by polymeric surfactant polyethylene glycol-phosphatidyleolamine (PEG-PE) and adjuvant monophosphoryl lipid A (MPLA). Our results show that PEG-PE transforms TEVs into micelle-like complexes by disrupting the original structure, facilitating antigens delivery to the cytoplasm, and cross-presentation by DCs. P-Pev particularly prevents the immunosuppressive impacts of TEVs on the ability of DCs to prime CD8+ T cells and eliminates the potency of TEVs to promote lung metastasis through their membrane-bound PD-L1. Finally, the P-Pev effectively induces neoantigen-specific cytotoxic T lymphocytes (CTLs) responses and exhibits excellent therapeutic effects in various murine tumor models. Also, the P-Pev induces neoantigen-specific antibodies, suggesting the involvement of humoral immunity in its anti-tumor effects. More importantly, it has been shown that P-Pev prepared by mutated tumor cells can retard these mutated tumor cell-established syngeneic tumors better than P-Pev prepared by original tumor cells, indicating the feasibility that leverages TEVs to prepare personalized tumor vaccines, and it is synergistically enhanced by PD-1 mAb combination. Collectively, we present a general strategy that offers a streamlined, cost-effective, and time-consuming approach to preparing personalized therapeutic tumor vaccines.

Anticancer signal transduction pathways of selenium nanoparticles in mouse colorectal cancer model

Despite significant advances in the treatment of colon cancer, this disease is extremely common, often requiring serious surgery followed by long-term drug treatment. Colon and rectal cancer remain dangerous forms of cancer due to the high degree of metastasis. The development and study of the effectiveness of anticancer drugs based on nanoparticles is an urgent task of modern biomedicine. Of particular interest are attempts to move research from the in vitro level to the in vivo level of preclinical studies. In the presented study, mice were subcutaneously implanted with MC-38 cell line, a tumor was grown, and selenium nanoparticles (SeNPs) with a diameter of 100 nm obtained using the laser ablation method were administered intraperitoneally. Using morphometric measurements, it was found that injections of 1 μg/g or 10 μg/g SeNPs inhibited weight loss of mice during cancer development, reduced tumor size by 2-2.5 times, and suppressed metastasis by 1.5-3 times. Analysis of selenium levels in mouse blood, liver and tumor samples by atomic absorption spectrometry after the end of SeNPs treatment showed that the nanoparticles increased selenium levels in the blood and liver of mice without a significant dose-dependence, whereas in tumors a dose-dependent increase in selenium concentration was detected from the concentration of nanoparticles, with 10 μg/g SeNPs causing a more pronounced increase in selenium concentration. Using PCR and Western blot analysis, it was possible to establish that SeNPs injections led to an increase in the expression of genes encoding anti-inflammatory and anti-hypoxic proteins, but reduced the expression of antioxidant selenium-containing proteins and proteins responsible for the proliferation of cancer cells. Both concentrations of SeNPs led to similar effects, but increasing the concentration of nanoselenium to 10 μg/g affected the expression of a larger number of genes and the effects on expression were more "bright". Thus, the complex of presented experiments showed that injections of selenium nanoparticles in concentrations of 1 μg/g or 10 μg/g are capable to transport by the bloodstream and accumulating in the highest concentration in colon adenocarcinoma, compared with liver, which indicates the targeting of SeNPs in relation to tumors even without functionalization by specific molecules. As a result, there was a change in the expression patterns of genes and a number of proteins, and as a result, there was a decrease in tumor volume, normalization of mouse weight and maintenance of positive dynamics throughout the entire observation period.

Neoantigen enriched biomimetic nanovaccine for personalized cancer immunotherapy

Personalized cancer vaccines elicit robust T cell immunity and anti-tumour potency, but identifying tumour-specific antigens remains challenging, severely constraining the therapeutic window. Biomimetic nanovaccines employing cancer cell membranes display inherent biocompatibility and stimulate T-cell responses against diverse tumour antigens, though tumours develop multiple mechanisms to reduce antigen presentation. Here we demonstrate a rapid and general strategy to fabricate personalized nanovaccines based on Antigen-Enriched tumor Cell Membranes (AECM) for early intervention. Interferon-γ potently stimulates antigen presentation across a broad range of cancer cell types. By coupling the generated AECM with PC7A adjuvant, a stimulator of interferon genes (STING)-activating polymer, the AECM@PC7A nanovaccine induces robust poly-neoepitopic T-cell responses even at low dosage, achieving significant tumour regression and metastasis inhibition in multiple murine cancer models. This anti-tumor response relies on MHC-I restricted antigen presentation and CD8+ T-cell activation, with dendritic cells presenting AECM antigens predominantly via cross-dressing to prime T-cells. AECM@PC7A exhibits remarkable anti-tumor efficacy when compared to vaccines with diverse formulations, and demonstrates therapeutic potential in post-surgical and humanized xenograft tumor models. This proof-of-concept study provides a promising universal avenue for the rapid development of personalized cancer vaccines applicable to early intervention for a broad range of patients.

Oral ENPP1 inhibitor designed using generative AI as next generation STING modulator for solid tumors

Despite the STING-type-I interferon pathway playing a key role in effective anti-tumor immunity, the therapeutic benefit of direct STING agonists appears limited. In this study, we use several artificial intelligence techniques and patient-based multi-omics data to show that Ectonucleotide Pyrophosphatase/Phosphodiesterase 1 (ENPP1), which hydrolyzes STING-activating cyclic GMP-AMP (cGAMP), is a safer and more effective STING-modulating target than direct STING agonism in multiple solid tumors. We then leverage our generative chemistry artificial intelligence-based drug design platform to facilitate the design of ISM5939, an orally bioavailable ENPP1-selective inhibitor capable of stabilizing extracellular cGAMP and activating bystander antigen-presenting cells without inducing either toxic inflammatory cytokine release or tumor-infiltrating T-cell death. In murine syngeneic models across cancer types, ISM5939 synergizes with targeting the PD-1/PD-L1 axis and chemotherapy in suppressing tumor growth with good tolerance. Our findings provide evidence supporting ENPP1 as an innate immune checkpoint across solid tumors and reports an AI design-aided ENPP1 inhibitor, ISM5939, as a cutting-edge STING modulator for cancer therapy, paving a path for immunotherapy advancements.

Structure-Guided Optimization of 2-Aminoquinazoline Hematopoietic Progenitor Kinase 1 Inhibitors for Improved Oral Bioavailability and Synergistic Antitumor Immunity

Hematopoietic progenitor kinase 1 (HPK1), a pivotal T-cell immunity suppressor, offers transformative potential to overcome immune checkpoint resistance, yet existing inhibitors fail to balance potency, selectivity, and pharmacokinetics. We developed a spatially resolved strategy within a unified chemical framework of our 2-aminoquinazoline core, integrating (1) high-affinity engagement of the HPK1 hinge-region subpocket (Leu23/Phe93/Gly95) through bidentate hydrogen bonding and hydrophobic packing with (2) strategic occupation of a solvent-exposed allosteric site to sterically block CYP3A4/2C9/2D6-mediated oxidative metabolism. Optimized compound 39 demonstrated subnanomolar binding affinity (IC50 = 0.70 nM) with moderate selectivity, combined with high metabolic stability in human liver microsomes (CLint < 1 mL/min/kg) and favorable oral bioavailability (>100%) in mice. In CT26 models, compound 39 synergized with anti-PD-1 (60% tumor growth inhibition) by expanding IFN-γ+CD8+ tumor-infiltrating lymphocytes (7-fold) and enhancing splenic IFN-γ production (3-fold). This work validates 2-aminoquinazolines as a novel HPK1 chemotype addressing metabolic instability─a key hurdle in kinase drug discovery.

Mapping the genetic landscape establishing a tumor immune microenvironment favorable for anti-PD-1 response

Identifying host genetic factors modulating immune checkpoint inhibitor (ICI) efficacy is experimentally challenging. Our approach, utilizing the Collaborative Cross mouse genetic resource, fixes the tumor genomic configuration while varying host genetics. We find that response to anti-PD-1 (aPD1) immunotherapy is significantly heritable in four distinct murine tumor models (H2: 0.18-0.40). For the MC38 colorectal carcinoma system, we map four significant ICI response quantitative trait loci (QTLs) with significant epistatic interactions. The differentially expressed genes within these QTLs that define responder genetics are highly enriched for processes involving antigen processing and presentation, allograft rejection, and graft vs. host disease (all p < 1 × 10-10). Functional blockade of two top candidate immune targets, GM-CSF and IL-2RB, completely abrogates the MC38 transcriptional response to aPD1 therapy. Thus, our in vivo experimental platform is a powerful approach for discovery of host genetic factors that establish the tumor immune microenvironment propitious for ICI response.

Unveiling the immunological terrain of pancreatic ductal adenocarcinoma: strategies to prompt immunotherapy from Mendelian randomization

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is challenging to treat due to its immunosuppressive tumor microenvironment (TME) and resistance to immune checkpoint inhibitors. This study aims to discover new therapeutic targets and predictive biomarkers for PDAC.

METHODS

Using Mendelian randomization, we studied causal relationships between PDAC and an array of immune cell traits, bacterial traits, inflammatory factors, and blood metabolites. We employed large genome-wide association study datasets and the two-sample MR approach for the investigation.

RESULTS

Our results highlight suggestive evidence of associations between PDAC and distinct immune cell phenotypes, revealing nuanced alterations across monocytes, T-cells, B-cells, dendritic cells, and myeloid-derived suppressor cells. Our study provides a granular view of the PDAC-immune interface, identifying key immune cell traits and their associations with PDAC. For instance, our findings suggest a detrimental reduction in various monocyte traits, alongside a decrease in B-cell populations. Conversely, certain T-cell subsets showed increased associations, indicating potential targets for immunotherapeutic strategies. The bacterial trait associations, particularly with Collinsella and Ruminococcus torques, highlight the gut microbiome's influence on immune modulation and PDAC pathogenesis. Additionally, the traits concerning Interleukin-12 subunit beta levels and T-cell surface glycoprotein CD5 levels further indicate their function of this complex interaction.

CONCLUSIONS

This study enhances our understanding of PDAC's resistance to immunotherapies and highlights the potential of personalized immunotherapy and metabolic pathway modulation in PDAC treatment. Our findings provide supportive evidence for research and clinical translation.

Fluorinated Ribonucleocarbohydrate Nanoparticles Allow Ultraefficient mRNA Delivery and Protein Expression in Tumor-Associated Myeloid Cells

Ribonucleic acids (RNA) are commonly formulated into lipid nanoparticles (LNP) for in vivo use, but challenges exist with systemic delivery and low in vivo expression efficiency. Inspired by ribonucleoprotein complexes in cells, we created synthetic ribonucleocarbohydrate (RNC) complexes based on cyclodextrin nanoparticles with ferrocenyl fluorocarbons capable of carrying mRNA and additional small-molecule drug payloads, facilitating lysosomal escape and immune stimulation all in the same nanoparticle. We show that this strategy results in highly efficient myeloid cell targeting (dendritic cells and MHC expressing macrophages) and protein expression following systemic administration. The RNC platform should have broad applications in vaccine development, immunosuppression, and immunostimulation for various diseases.

Dying to survive: harnessing inflammatory cell death for better immunotherapy

Immunotherapy has transformed cancer treatment paradigms, but its effectiveness depends largely on the immunogenicity of the tumor. Unfortunately, the high resemblance of cancer to normal tissues makes most tumors immunologically 'cold', with a poor response to immunotherapy. Danger signals are critical for breaking immune tolerance and mobilizing robust, long-lasting antitumor immunity. Recent studies have identified inflammatory cell death modalities and their power in providing danger signals to trigger optimal tumor suppression. However, key mediators of inflammatory cell death are preferentially silenced during early tumor immunoediting. Strategies to rejuvenate inflammatory cell death hold great promise for broadening immunotherapy-responsive tumors. In this review, we examine how inflammatory cell death enhances tumor immunogenicity, how it is suppressed during immunoediting, and the potential of harnessing it for improved immunotherapy.

Functional Polarization of Liver Macrophages by Glyco Gold Nanoparticles

Macrophages are crucial drivers of innate immunity. Reprogramming macrophages to a restorative phenotype in cancer or autoimmune diseases can stop their cancer-promoting activity or trigger anti-inflammatory immunity. Glycans have emerged as key components for immunity as they are involved in many pathophysiological disorders. Previous studies have demonstrated that supraphysiological amounts of mannose (Man) or sialic acid (Sia) can inhibit tumor growth and stimulate differentiation of regulatory T cells. Man is known to affect glucose metabolism in glycolysis by competing for the same intracellular transporters and affecting macrophage polarization, whereas Sia alters macrophage differentiation via signaling through Siglec-1. Herein, this work describes a macrophage targeting platform using gold nanoparticles (GNPs) functionalized with Man and Sia monosaccharides which exhibit high liver tropism. A single dose of glyco-GNPs can convert macrophages to a restorative phenotype in two completely different immune environments. Man promotes tumor-associated macrophages toward an antitumorigenic activity in a MC38 liver colorectal cancer model by secretion of TNF-α, IL -1β, and IL -6 in the tumor microenvironment. However, in a proinflammatory environment, as observed in a mouse model of autoimmune disease, primary biliary cholangitis, Man impairs the production of TNF-α, IL-1β, Arg1, and IL-6 cytokines. The results probe the dual role of Man in macrophage repolarization in response to the immune system. This study is a proof-of-concept that demonstrates that nanomedicine using specific glycans designed to target other immune cells such as myeloid cells, are a promising strategy not only against cancer but also against other pathologies such as autoimmune diseases.

Comprehensive assessment of computational methods for cancer immunoediting

Cancer immunoediting reflects the role of the immune system in eliminating tumor cells and shaping tumor immunogenicity, which leaves marks in the genome. In this study, we systematically evaluate four methods for quantifying immunoediting. In colorectal cancer samples from The Cancer Genome Atlas, we found that these methods identified 78.41%, 46.17%, 36.61%, and 4.92% of immunoedited samples, respectively, covering 92.90% of all colorectal cancer samples. Comparison of 10 patient-derived xenografts (PDXs) with their original tumors showed that different methods identified reduced immune selection in PDXs ranging from 44.44% to 60.0%. The proportion of such PDX-tumor pairs increases to 77.78% when considering the union of results from multiple methods, indicating the complementarity of these methods. We find that observed-to-expected ratios highly rely on neoantigen selection criteria and reference datasets. In contrast, HLA-binding mutation ratio, immune dN/dS, and enrichment score of cancer cell fraction were less affected by these factors. Our findings suggest integration of multiple methods may benefit future immunoediting analyses.

A microRNA-regulated transcriptional state defines intratumoral CD8+ T cells that respond to immunotherapy

The rising incidence of advanced-stage colorectal cancer (CRC) and poor survival outcomes necessitate new and effective therapies. Immune checkpoint inhibitors (ICIs), specifically anti-PD-1 therapy, show promise, yet clinical determinants of a positive response are suboptimal. Here, we identify microRNA-155 (miR-155) as necessary for CD8+ T cell-infiltrated tumors through an unbiased in vivo CRISPR-Cas9 screen identifying functional tumor antigen-specific CD8+ T cell-expressed microRNAs. T cell miR-155 is required for anti-PD-1 responses and for a vital intratumor CD8+ T cell differentiation cascade by repressing Ship-1, inhibiting Tcf-1 and stemness, and subsequently enhancing Cxcr6 expression, anti-tumor immunity, and effector functions. Based on an underlying miR-155-dependent CD8+ T cell transcriptional profile, we identify a gene signature that predicts ICI responses across 12 diverse cancers. Together, our findings support a model whereby miR-155 serves as a central regulator of CD8+ T cell-dependent cancer immunity and ICI responses that may be leveraged for future therapeutics.

Opposing Functions of Distinct Regulatory T Cell Subsets in Colorectal Cancer

Regulatory T (Treg) cells contribute to solid organ cancer progression, except in colorectal cancer (CRC) despite being abundantly present. Here, we demonstrate that two distinct tumoral IL-10⁺ and IL-10⁻ Treg cell subsets exert opposing functions by counteracting and promoting CRC tumor growth, respectively. The tumor restraining activity of IL-10⁺ Treg cells was mediated by their suppression of effector CD4 T cell production of IL-17, which directly stimulates CRC tumor cell proliferation. Consistently, IL-10⁻ Treg cells were more abundant in both mouse and human CRC tumors than in tumor-adjacent normal tissues, whereas IL-10+ Treg cells exhibited the opposite distribution. Furthermore, relative abundance of IL-10⁺ and IL-10⁻ Treg cells correlated with better and worse disease prognoses in human CRC, respectively. This functional dichotomy between Treg cell subsets provides a rationale for therapeutic strategies to selectively target pro-tumoral Treg cells while preserving their anti-tumoral counterparts across barrier tissue cancers that harbor both subsets.

Single-cell data-driven design of armed oncolytic virus to boost cooperative innate-adaptive immunity against cancer

Oncolytic viruses have been considered promising cancer immunotherapies. However, oncovirotherapy agents impart durable responses in only a subset of cancer patients. Thus, exploring the cellular and molecular mechanisms underlying the heterogeneous responses in patients can provide guidance to develop more effective oncolytic virus therapies. Single-cell RNA sequencing (scRNA-seq) analysis of tumors responsive and non-responsive to oncovirotherapy revealed signatures of the tumor immune microenvironment associated with immune response. Thus, we designed and constructed an armed oncolytic virus, OV-5A, that expressed five genes with non-redundant functions. OV-5A treatment exhibits robust immune response against various tumors in multiple mouse models, peripheral blood mononuclear cell -patient-derived xenograft models, organoid-immune cell co-culture systems, and patient tissue sections by activating a cooperative innate-adaptive immune response against tumor cells. scRNA-seq analysis of complete responders and partial responders to OV-5A treatment guided the design of combination therapy of OV-5A. This data-driven approach paves an innovative way to rationalize the design of oncolytic virus and multi-agent combination therapies.

Phaseolus acutifolius Recombinant Lectin Exerts Differential Proapoptotic Activity on EGFR+ and EGFR- Colon Cancer Cells and Provokes T Cell-Assisted Antitumor Responses in Mice

Background:rTBL-1, a recombinant lectin from Phaseolus acutifolius, exhibit proapoptotic activity on colon cancer cells and inhibitory properties on colon tumorigenesis in vivo. Apoptosis has been associated with a phospho-EGFR/phospho-p38/phospho-p53 mechanistic axis. Immunogenicity data have been observed in treated animals, but its possible involvement in the antitumor response remained unexplored. Objective: We investigated whether the cytotoxic activity of rTBL-1 depends on EGFR and its capacity to produce antitumor responses on syngeneic colon cancer in mice, with and without T cells, in order to explore its possible involvement in the process. Results:rTBL-1 exhibited cytotoxic effects in a concentration-dependent manner in both EGFR+ (MC-38) and EGFR- (CT-26) colon cancer cells with LC50 values of 23.50 and 30.01 µg/mL, respectively (p = 0.063). Apoptotic effects were slower and longer-lasting in MC-38 than in CT-26 cells. Significant increases in caspase-3 proteolytic activation and PARP1 cleavage were detected in both cell types, despite PARP1 rheostasis in CT-26 cells. Intralesional treatment with rTBL-1 inhibited the growth of established tumors in immunocompetent BALB/c mice in 27.81% (p = 0.0008) with a benefit in survival (p = 0.022), but not in immunodeficient BALB/c nude mice. Conclusions:rTBL-1 induces apoptosis in colon cancer cells by EGFR independent mechanisms, although its presence could be related to deeper responses. Unresponsiveness in nude mice indicated that rTBL-1 antitumor effect is the synergistic result of apoptosis induction and T cell-mediated cytotoxicity in the tumor. Future studies will focus on the immunogenic effects triggered by the antitumor activity of rTBL-1 in colon cancer.

OASL promotes immune evasion in pancreatic ductal adenocarcinoma by enhancing autolysosome-mediated degradation of MHC-I

Rationale: Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignancy with a global prevalence and poor prognosis, largely due to immune escape mechanisms. However, the potential reasons for the decreased infiltration of cytotoxic T lymphocytes (CTLs) in PDAC remain inadequately understood. In this study, we aimed to elucidate the molecular mechanisms contributing to the low-CTLs infiltration in patients with PDAC. Methods: Bioinformatic analyses were used to identify key factors associated with low-CTLs infiltration in PDAC and the role of oligoadenylate synthetase-like (OASL) was mainly focused in our study. Immunohistochemistry (IHC) was used to assess the relationship between the expression of OASL and the prognosis of patients. Western blotting, Flow cytometry, Co-immunoprecipitation and Immunofluorescence were applied to elucidate the molecular mechanism by which OASL mediates immune escape in PDAC. The orthotopic PDAC models were constructed to evaluate the effects of OASL-knockdown on CD8+ T cells infiltration and tumor growth in vivo. Results: OASL was found to be significantly upregulated in PDAC and negatively correlated with the major histocompatibility complex class I (MHC-I) expression, which is associated with worse patient prognosis. Notably, OASL-knockdown leads to a significant increase in CD8+ T cell infiltration and slows tumor growth in vivo. Mechanistic studies revealed that OASL -knockdown restored the total and surface MHC-I level through impairing neighbor of BRCA1 gene 1 (NBR1)-mediated autophagy-lysosomal degradation of MHC-I. Conclusions: Targeting OASL enhances the immune response in PDAC, providing a novel therapeutic strategy to improve outcomes in PDAC patients.

Acquired resistance to PD-L1 inhibition enhances a type I IFN-regulated secretory program in tumors

Therapeutic inhibition of programmed cell death ligand (PD-L1) is linked to alterations in interferon (IFN) signaling. Since IFN-regulated intracellular signaling can control extracellular secretory programs in tumors to modulate immunity, we examined IFN-related secretory changes in tumor cells following resistance to PD-L1 inhibition. Here we report an anti-PD-L1 treatment-induced secretome (PTIS) in tumor models of acquired resistance that is regulated by type I IFNs. These secretory changes can suppress activation of T cells ex vivo while diminishing tumor cell cytotoxicity, revealing that tumor-intrinsic treatment adaptations can exert broad tumor-extrinsic effects. When reimplanted in vivo, resistant tumor growth can slow or stop when PTIS components are disrupted individually, or when type I IFN signaling machinery is blocked. Interestingly, genetic and therapeutic disruption of PD-L1 in vitro can only partially recapitulate the PTIS phenotype highlighting the importance of developing in vivo-based resistance models to more faithfully mimic clinically-relevant treatment failure. Together, this study shows acquired resistance to immune-checkpoint inhibitors 'rewires' tumor secretory programs controlled by type I IFNs that, in turn, can protect from immune cell attack.

Mitochondrial metabolic reprogramming of macrophages and T cells enhances CD47 antibody-engineered oncolytic virus antitumor immunity

BACKGROUND

Although immunotherapy can reinvigorate immune cells to clear tumors, the response rates are poor in some patients. Here, CD47 antibody-engineered oncolytic viruses (oAd-αCD47) were employed to lyse tumors and activate immunity. The oAd-αCD47 induced comprehensive remodeling of the tumor microenvironment (TME). However, whether the acidic TME affects the antitumor immunotherapeutic effects of oncolytic viruses-αCD47 has not been clarified.

METHODS

To assess the impact of oAd-αCD47 treatment on the TME, we employed multicolor flow cytometry. Glucose uptake was quantified using 2NBDG, while mitochondrial content was evaluated with MitoTracker FM dye. pH imaging of tumors was performed using the pH-sensitive fluorophore SNARF-4F. Moreover, changes in the calmodulin-dependent protein kinase II (CaMKII)/cyclic AMP activates-responsive element-binding proteins (CREB) and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC1α) signaling pathway were confirmed through western blotting and flow cytometry.

RESULTS

Here, we identified sodium bicarbonate (NaBi) as the potent metabolic reprogramming agent that enhanced antitumor responses in the acidic TME. The combination of NaBi and oAd-αCD47 therapy significantly inhibited tumor growth and produced complete immune control in various tumor-bearing mouse models. Mechanistically, combination therapy mainly reduced the number of regulatory T cells and enriched the ratio of M1-type macrophages TAMs (M1.TAMs) to M2-type macrophages TAMs (M2.TAMs), while decreasing the abundance of PD-1+TIM3+ expression and increasing the expression of CD107a in the CD8+ T cells. Furthermore, the combination therapy enhanced the metabolic function of T cells and macrophages by upregulating PGC1α, a key regulator of mitochondrial biogenesis. This metabolic improvement contributed to a robust antitumor response. Notably, the combination therapy also promoted the generation of memory T cells, suggesting its potential as an effective neoadjuvant treatment for preventing postoperative tumor recurrence and metastasis.

CONCLUSIONS

Tumor acidic microenvironment impairs mitochondrial energy metabolism in macrophages and T cells inducing oAd-αCD47 immunotherapeutic resistance. NaBi improves the acidity of the TME and activates the CaMKII/CREB/PGC1α mitochondrial biosynthesis signaling pathway, which reprograms the energy metabolism of macrophages and T cells in the TME, and oral NaBi enhances the antitumor effect of oAd-αCD47.

CAR-redirected natural killer T cells demonstrate superior antitumor activity to CAR-T cells through multimodal CD1d-dependent mechanisms

Human natural killer T (NKT) cells have been proposed as a promising cell platform for chimeric antigen receptor (CAR) therapy in solid tumors. Here we generated murine CAR-NKT cells and compared them with CAR-T cells in immune-competent mice. Both CAR-NKT cells and CAR-T cells showed similar antitumor effects in vitro, but CAR-NKT cells showed superior antitumor activity in vivo via CD1d-dependent immune responses in the tumor microenvironment. Specifically, we show that CAR-NKT cells eliminate CD1d-expressing M2-like macrophages. In addition, CAR-NKT cells promote epitope spreading and activation of endogenous T cell responses against tumor-associated neoantigens. Finally, we observed that CAR-NKT cells can co-express PD1 and TIM3 and show an exhaustion phenotype in a model of high tumor burden. PD1 blockade as well as vaccination augmented the antitumor activity of CAR-NKT cells. In summary, our results demonstrate the multimodal function of CAR-NKT cells in solid tumors, further supporting the rationale for developing CAR-NKT therapies in the clinic.

Evaluating the Impact of Adjunctive Partial Cryoablation on Dual Checkpoint Inhibitor Immunotherapy Response in a Murine Model

Purpose To evaluate the impact of adjunctive partial cryoablation on checkpoint inhibitor (CPI) immunotherapy response. Materials and Methods One hundred fifty-six mice (equal number of male and female animals) with dual-implanted tumor models were treated with dual CPI or a vehicle and randomized to treatment of a single tumor with partial cryoablation. Tumors were followed for 60 days following cryoablation for response assessment. In additional groups, the tumor microenvironment was characterized via flow cytometry, cytokine analysis, and immunohistochemistry. Statistical comparison was made between the different treatment groups regarding T-cell infiltration and activation characteristics within the noncryoablated tumor and cytokine levels within the partially ablated tumor. Additionally, qualitative assessment of T-cell activation within the cryoablated and noncryoablated tumors at immunofluorescence was carried out. Results At 60 days following treatment, CPI and adjunctive cryoablation-treated MC-38 mice had a significantly increased survival rate (79%) compared with mice treated with CPI alone (61%; P < .001). CT-26 mice also had an increased survival rate (57% vs 35%, respectively; P = .04). Following cryoablation, increases in inflammatory cytokines and chemokines within the treated tumors were observed. Flow cytometry of noncryoablated tumor showed increased CD8 T-cell activation. Immunofluorescence and histologic evaluation following cryoablation further demonstrated a robust CD8 T-cell and myeloid infiltrate. Conclusion Adjunctive cryoablation significantly increased the response to dual CPI in multiple cancer models at both partially ablated and distant (nonablated) tumor sites. Immune analysis suggests cryoablation promotes a vigorous immune response within the partially cryoablated tumor that increases activation of the adaptive immune system within distant tumor sites. Keywords: Cancer, Cryoablation, Checkpoint Inhibitor Immunotherapy, Tumor Response Supplemental material is available for this article. © RSNA, 2024.

Percutaneous Delivery of Oncogel for Targeted Liver Tumor Ablation and Controlled Release of Therapeutics

Advanced-stage liver cancers are associated with poor prognosis and have limited treatment options, often leading the patient to hospice care. Percutaneous intratumoral injection of anticancer agents has emerged as a potential alternative to systemic therapy to overcome tumor barriers, increase bioavailability, potentiate immunotherapy, and avoid systemic toxicity, which advanced-stage cancer patients cannot tolerate. Here, an injectable OncoGel (OG) comprising of a nanocomposite hydrogel loaded with an ionic liquid (IL) is developed for achieving a predictable and uniform tumor ablation and long-term slow release of anticancer agents into the ablation zone. Rigorous mechanical, physiochemical, drug release, cytotoxicity experiments, and ex vivo human tissue testing identify an injectable version of the OG with bactericidal properties against highly resistant bacteria. Intratumoral injection of OG loaded with Nivolumab (Nivo) and doxorubicin (Dox) into highly malignant tumor models in mice, rats, and rabbits demonstrates enhanced survival and tumor regression associated with robust tissue ablation and drug distribution throughout the tumor. Mass cytometry and proteomic studies in a mouse model of colorectal cancer that often metastasizes to the liver indicate an enhanced anticancer immune response following the intratumoral injection of OG. OG may augment immunotherapy and potentially improve outcomes in liver cancer patients.

ACSL6-activated IL-18R1-NF-κB promotes IL-18-mediated tumor immune evasion and tumor progression

Aberrant activation of IL-18 signaling regulates tumor immune evasion and progression. However, the underlying mechanism remains unclear. Here, we report that long-chain acyl-CoA synthase 6 (ACSL6) is highly expressed in liver cancer and correlated with poor prognosis. ACSL6 promotes tumor growth, metastasis, and immune evasion mediated by IL-18, independent of its metabolic enzyme activity. Mechanistically, upon IL-18 stimulation, ACSL6 is phosphorylated by ERK2 at S674 and recruits IL-18RAP to interact with IL-18R1, thereby reinforcing the IL-18R1-IL-18RAP heterodimer and triggering NF-κB-dependent gene expression to facilitate tumor development. Furthermore, the up-regulation of CXCL1 and CXCL5 by ACSL6 promotes tumor-associated neutrophil and tumor-associated macrophage recruitment, thereby inhibiting cytotoxic CD8+ T cell infiltration. Ablation or S674A mutation of ACSL6 potentiated anti-PD-1 therapeutic efficacy by increasing the effector activity of intertumoral CD8+ T cells. We revealed that ACSL6 is a potential adaptor that activates IL-18-NF-κB axis-mediated tumor immune evasion and provides valuable insights for developing effective immunotherapy strategies for cancer.

Mitochondrial rewiring with small-molecule drug-free nanoassemblies unleashes anticancer immunity

The immunosuppressive tumor microenvironment (TME) remains a major obstacle to tumor control and causes suboptimal responses to immune checkpoint blockade (ICB) therapy. Thus, developing feasible therapeutic strategies that trigger inflammatory responses in the TME could improve the ICB efficacy. Mitochondria play an essential role in inflammation regulation and tumor immunogenicity induction. Herein, we report the discovery and characterization of a class of small molecules that can recapitulate aqueous self-assembly behavior, specifically target cellular organelles (e.g., mitochondria), and invigorate tumor cell immunogenicity. Mechanistically, this nanoassembly platform dynamically rewires mitochondria, induces endoplasmic reticulum stress, and causes apoptosis/paraptosis-associated immunogenic cell death. After treatment, stressed and dying tumor cells can act as prophylactic or therapeutic cancer vaccines. In preclinical mouse models of cancers with intrinsic or acquired resistance to PD-1 blockade, the local administration of nanoassemblies inflames the immunologically silent TME and synergizes with ICB therapy, generating potent antitumor immunity. This chemically programmed small-molecule immune enhancer acts distinctly from regular cytotoxic therapeutics and offers a promising strategy for synchronous and dynamic tailoring of innate immunity to achieve traceless cancer therapy and overcome immunosuppression in cancers.

Uniform Polymeric Nanovaccine Platform for Improving the Availability and Efficacy of Neoantigen Peptides

Personalized cancer vaccines targeting specific neoantigens have been envisioned as one of the most promising approaches in cancer immunotherapy. However, the physicochemical variability of the identified neoantigens limits their efficacy as well as vaccine manufacturing in a uniform format. Herein, we developed a uniform nanovaccine platform based on poly(2-oxazoline)s (POx) to chemically conjugate neoantigen peptides, regardless of their physicochemical properties. This vaccine system could self-assemble into nanoparticles with uniform size (around 50 nm) and improve antigen accumulation as well as infiltration in the lymph node to increase antigen presentation. In vivo vaccination using this system conjugated with three predicted peptide neoantigen peptides from the MC38 tumor cell line induced 100% robust CD8+ T cell responses and superior tumor clearance compared to free peptides. This POx-based vaccine carrier represents a generalizable approach to increase the availability and efficacy of screened neoantigen peptides for a personalized cancer vaccine.

E-cigarette exposure disrupts antitumor immunity and promotes metastasis

Electronic cigarettes (e-cigarettes) are thought to pose low risk of cancer because the components of e-cigarette liquid are not carcinogens. We analyzed the effects of the two major components, PG/VG and nicotine, on tumor development in preclinical models. We found that PG/VG promoted tumor cell migration in migration assays and contributed to more aggressive, metastatic, and immunosuppressive tumors in vivo, aggravated by the presence of nicotine. Whole body exposure of mice to PG/VG and nicotine rendered animals more susceptible to developing tumors with high frequencies of infiltrating proinflammatory macrophages expressing IL-6 and TNFα. Moreover, tumor-infiltrating and circulating T cells in e-cigarette exposed mice showed increased levels of immune checkpoints including CTLA4 and PD-1. Treatment with anti-CTLA4 antibody was able to abrogate metastasis with no detrimental effects on its ability to induce tumor regression in exposed mice. These findings suggest that the major components used in e-cigarette fluid can impact tumor development through induced immunosuppression.

Nilotinib boosts the efficacy of anti-PDL1 therapy in colorectal cancer by restoring the expression of MHC-I

BACKGROUND

Although immune checkpoint inhibitors (ICIs) have revolutionized the landscape of cancer treatment, only a minority of colorectal cancer (CRC) patients respond to them. Enhancing tumor immunogenicity by increasing major histocompatibility complex I (MHC-I) surface expression is a promising strategy to boost the antitumor efficacy of ICIs.

METHODS

Dual luciferase reporter assays were performed to find drug candidates that can increase MHC-I expression. The effect of nilotinib on MHC-I expression was verified by dual luciferase reporter assays, qRT-PCR, flow cytometry and western blotting. The biological functions of nilotinib were evaluated through a series of in vitro and in vivo experiments. Using RNA-seq analysis, immunofluorescence assays, western blotting, flow cytometry, rescue experiments and microarray chip assays, the underlying molecular mechanisms were investigated.

RESULTS

Nilotinib induces MHC-I expression in CRC cells, enhances CD8+ T-cell cytotoxicity and subsequently enhances the antitumor effects of anti-PDL1 in both microsatellite instability and microsatellite stable models. Mechanistically, nilotinib promotes MHC-I mRNA expression via the cGAS-STING-NF-κB pathway and reduces MHC-I degradation by suppressing PCSK9 expression in CRC cells. PCSK9 may serve as a potential therapeutic target for CRC, with nilotinib potentially targeting PCSK9 to exert anti-CRC effects.

CONCLUSION

This study reveals a previously unknown role of nilotinib in antitumor immunity by inducing MHC-I expression in CRC cells. Our findings suggest that combining nilotinib with anti-PDL1 therapy may be an effective strategy for the treatment of CRC.

Monitoring mouse papillomavirus-associated cancer development using longitudinal Pap smear screening

A substantial percentage of the population remains at risk for cervical cancer due to pre-existing human papillomavirus (HPV) infections, despite prophylactic vaccines. Early diagnosis and treatment are crucial for better disease outcomes. The development of new treatments heavily relies on suitable preclinical model systems. Recently, we established a mouse papillomavirus (MmuPV1) model that is relevant to HPV genital pathogenesis. In the current study, we validated the use of Papanicolaou (Pap) smears, a valuable early diagnostic tool for detecting HPV cervical cancer, to monitor disease progression in the MmuPV1 mouse model. Biweekly cervicovaginal swabs were collected from the MmuPV1-infected mice for viral DNA quantitation and cytology assessment. The Pap smear slides were evaluated for signs of epithelial cell abnormalities using the 2014 Bethesda system criteria. Tissues from the infected mice were harvested at various times post-viral infection for additional histological and virological assays. Over time, increased viral replication was consistent with higher levels of viral DNA, and it coincided with an uptick in epithelial cell abnormalities with higher severity scores noted as early as 10 weeks after viral infection. The cytological results also correlated with the histological evaluation of tissues harvested simultaneously. Both immunocompromised and immunocompetent mice with squamous cell carcinoma (SCC) cytology also developed vaginal SCCs. Notably, samples from the MmuPV1-infected mice exhibited similar cellular abnormalities compared to the corresponding human samples at similar disease stages. Hence, Pap smear screening proves to be an effective tool for the longitudinal monitoring of disease progression in the MmuPV1 mouse model.

IMPORTANCE

Papanicolaou (Pap) smear has saved millions of women's lives as a valuable early screening tool for detecting human papillomavirus (HPV) cervical precancers and cancer. However, more than 200,000 women in the United States alone remain at risk for cervical cancer due to pre-existing HPV infection-induced precancers, as there are currently no effective treatments for HPV-associated precancers and cancers other than invasive procedures including a loop electrosurgical excision procedure (LEEP) to remove abnormal tissues. In the current study, we validated the use of Pap smears to monitor disease progression in our recently established mouse papillomavirus model. To the best of our knowledge, this is the first study that provides compelling evidence of applying Pap smears from cervicovaginal swabs to monitor disease progression in mice. This HPV-relevant cytology assay will enable us to develop and test novel antiviral and anti-tumor therapies using this model to eliminate HPV-associated diseases and cancers.

Estrogen Receptor Blockade Potentiates Immunotherapy for Liver Metastases by Altering the Liver Immunosuppressive Microenvironment

Liver metastases (LM) remain a major cause of cancer-related death and are a major clinical challenge. LM and the female sex are predictors of a poorer response to immunotherapy but the underlying mechanisms remain unclear. We previously reported on a sexual dimorphism in the control of the tumor microenvironment (TME) of colorectal carcinoma liver metastases (CRCLM) and identified estrogen as a regulator of an immunosuppressive TME in the liver. Here we aimed to assess the effect of estrogen deprivation on the cytokine/chemokine profile associated with CRCLM, using a multiplex cytokine array and the RNAscope technology, and its effects on the innate and adaptive immune responses in the liver. We also evaluated the benefit of combining the selective estrogen-receptor degrader Fulvestrant with immune checkpoint blockade for the treatment of CRCLM. We show that estrogen depletion altered the cytokine/chemokine repertoire of the liver, decreased macrophage polarization, as reflected in reduced accumulation of tumor infiltrating M2 macrophages and increased the accumulation of CCL5+/CCR5+ CD8+ T and NKT cells in the liver TME. Similar results were obtained in a murine pancreatic ductal adenocarcinoma model. Importantly, treatment with Fulvestrant also increased the accumulation of CD8+CCL5+, CD8+CCR5+ T and NK cells in the liver TME and enhanced the therapeutic benefit of anti-PD1 immunotherapy, resulting in a significant reduction in the outgrowth of LM. Taken together, our results show that estrogen regulates immune cell recruitment to the liver and suggest that inhibition of estrogen action could potentiate the tumor-inhibitory effect of immunotherapy in hormone-independent and immunotherapy-resistant metastatic cancer.

SIGNIFICANCE

The immune microenvironment of the liver plays a major role in controlling the expansion of hepatic metastases and is regulated by estrogen. We show that treatment of tumor-bearing mice with an estrogen receptor degrader potentiated an anti-metastatic effect of immunotherapy. Our results provide mechanistic insight into clinical findings and a rationale for evaluating the efficacy of combination anti-estrogen and immunotherapy for prevention and/or treatment of hepatic metastases in female patients.

Evaluation of Efficacy and Safety in First-Line Treatment Methods for Extensive-Stage Small Cell Lung Cancer: A Comprehensive Comparative Study of Chemotherapy, Targeted Therapy Combined With Chemotherapy, and Immunotherapy Combined With Chemotherapy

BACKGROUND

Small cell lung cancer (SCLC) is a highly aggressive tumor with limited effectiveness in its standard chemotherapy treatment. Targeted antiangiogenic therapy and immune checkpoint inhibitors (ICIs) have demonstrated potential as alternative treatments for extensive-stage SCLC (ES-SCLC). However, there is insufficient comparative evidence available to determine the optimal first-line treatment option between ICIs plus chemotherapy and targeted antiangiogenic therapy plus chemotherapy.

OBJECTIVE

This study is aimed at analyzing clinical data from ES-SCLC patients treated at the First Affiliated Hospital of Bengbu Medical College between June 2021 and June 2023. The study compared the efficacy and safety of three first-line treatment regimens: standard chemotherapy, antiangiogenic therapy combined with chemotherapy, and immune combination therapy.

METHODS

Patients who met the inclusion criteria were divided into three groups: chemotherapy, immune combination therapy, and antiangiogenic therapy combined with chemotherapy. The study collected data on clinical characteristics, treatment regimens, and adverse reactions. The analysis included objective response rate (ORR), duration of response (DoR), disease control rate (DCR), progression-free survival (PFS), and treatment safety.

RESULTS

A total of 101 patients were included in the study, with 49 receiving chemotherapy alone, 19 receiving antiangiogenic therapy, and 33 receiving immune combination therapy. The ORRs were 78.9% for antiangiogenic therapy, 72.7% for immune combination therapy, and 42.9% for chemotherapy alone. The median PFS was 8.0 months for antiangiogenic therapy, 7.8 months for immune combination therapy, and 5.2 months for chemotherapy alone. Both combination therapy groups demonstrated superior efficacy compared to chemotherapy alone.

CONCLUSION

Targeted combined chemotherapy and immune combination chemotherapy showed superior efficacy as first-line treatments for ES-SCLC compared to chemotherapy alone, with manageable adverse reactions.

ATM inhibition enhance immunotherapy by activating STING signaling and augmenting MHC Class I

Accumulating evidence supports the concept that DNA damage response targeted therapies can improve antitumor immune response by increasing the immunogenicity of tumor cells and improving the tumor immune microenvironment. Ataxia telangiectasia mutated (ATM) is a core component of the DNA repair system. Although the ATM gene has a significant mutation rate in many human cancers, including colorectal, prostate, lung, and breast, it remains understudied compared with other DDR-involved molecules such as PARP and ATR. Here, we found that either gene knockout or drug intervention, ATM inhibition activated the cGAS/STING pathway and augmented MHC class I in CRC cells, and these effects could be amplified by radiation. Furthermore, we found that MHC class I upregulation induced by ATM inhibition is dependent on the activation of the NFκB/IRF1/NLRC5 pathway and independent of STING. Animal experiments have shown increasing infiltration and cytotoxic function of T cells and better survival in ATM-deficient tumors. This work indicated that ATM nonsense mutation predicted the clinical benefits of radiotherapy combined with immune checkpoint blockade for patients with CRC. It also provides a molecular mechanism rationale for ATM-targeted agents for patients with CRC.

IL-1R signaling drives enteric glia-macrophage interactions in colorectal cancer

Enteric glia have been recently recognized as key components of the colonic tumor microenvironment indicating their potential role in colorectal cancer pathogenesis. Although enteric glia modulate immune responses in other intestinal diseases, their interaction with the colorectal cancer immune cell compartment remains unclear. Through a combination of single-cell and bulk RNA-sequencing, both in murine models and patients, here we find that enteric glia acquire an immunomodulatory phenotype by bi-directional communication with tumor-infiltrating monocytes. The latter direct a reactive enteric glial cell phenotypic and functional switch via glial IL-1R signaling. In turn, tumor glia promote monocyte differentiation towards pro-tumorigenic SPP1+ tumor-associated macrophages by IL-6 release. Enteric glia cell abundancy correlates with worse disease outcomes in preclinical models and colorectal cancer patients. Thereby, our study reveals a neuroimmune interaction between enteric glia and tumor-associated macrophages in the colorectal tumor microenvironment, providing insights into colorectal cancer pathogenesis.

Fasting Blood Glucose-Based Novel Predictors in Detecting Metastases and Predicting Prognosis for Patients with PNENs

OBJECTIVE

To explore three novel fasting blood glucose (FBG)-based novel indicators, including the FBG-to-albumin ratio (FAR), FBG-to-lymphocytes ratio (FLR), and FBG-to-hemoglobin ratio (FHR), in predicting prognosis and detecting metastasis for patients with pancreatic neuroendocrine neoplasms (pNENs) after resection.

MATERIALS AND METHODS

A total of 178 pNENs patients who underwent surgical resection were included in this study. Receiver operating characteristic (ROC) curves were used to evaluate the diagnosis values of FAR, FLR, and FHR, and the cutoff values were obtained for further analyses. Univariate and multivariate analyses were conducted to determine the independent predictors. The Kaplan-Meier method was used to evaluate the progression-free survival (PFS) and overall survival (OS) of the pNENs patients.

RESULTS

The optimal cutoff values of FAR, FLR, and FHR were 0.17, 2.85, and 0.028, respectively. As for PFS, the area under the curve (AUC) was 0.693 for FAR, 0.690 for FLR, and 0.661 for FHR, respectively. The AUC was 0.770, 0.692, and 0.715 accordingly for OS. The groups with lower FAR, FLR, and FHR were significantly associated with prolonged PFS and OS (p < 0.05). In patients with metastasis, the lower FAR group was correlated with significantly longer PFS and OS (p = 0.022 and 0.002, respectively). The FLR was an independent predictor of PFS in pNENs patients, and the FAR was a predictor of OS. FAR was an independent indicator of PFS in patients with metastasis.

CONCLUSIONS

Preoperative FAR, FLR, and FHR are effective in predicting the prognosis of pNEN patients and detecting the synchronous metastases.

Mapping the genetic landscape establishing a tumor immune microenvironment favorable for anti-PD-1 response in mice and humans

Identifying host genetic factors modulating immune checkpoint inhibitor (ICI) efficacy has been experimentally challenging because of variations in both host and tumor genomes, differences in the microbiome, and patient life exposures. Utilizing the Collaborative Cross (CC) multi-parent mouse genetic resource population, we developed an approach that fixes the tumor genomic configuration while varying host genetics. With this approach, we discovered that response to anti-PD-1 (aPD1) immunotherapy was significantly heritable in four distinct murine tumor models (H2 between 0.18-0.40). For the MC38 colorectal carcinoma system (H2 = 0.40), we mapped four significant ICI response quantitative trait loci (QTL) localized to mouse chromosomes (mChr) 5, 9, 15 and 17, and identified significant epistatic interactions between specific QTL pairs. Differentially expressed genes within these QTL were highly enriched for immune genes and pathways mediating allograft rejection and graft vs host disease. Using a cross species analytical approach, we found a core network of 48 genes within the four QTLs that showed significant prognostic value for overall survival in aPD1 treated human cohorts that outperformed all other existing validated immunotherapy biomarkers, especially in human tumors of the previously defined immune subtype 4. Functional blockade of two top candidate immune targets within the 48 gene network, GM-CSF and high affinity IL-2/IL-15 signaling, completely abrogated the MC38 tumor transcriptional response to aPD1 therapy in vivo. Thus, we have established a powerful cross species in vivo platform capable of uncovering host genetic factors that establish the tumor immune microenvironment configuration propitious for ICI response.

Further knowledge and developments in resistance mechanisms to immune checkpoint inhibitors

The past decade has witnessed a revolution in cancer treatment, shifting from conventional drugs (chemotherapies) towards targeted molecular therapies and immune-based therapies, in particular immune-checkpoint inhibitors (ICIs). These immunotherapies release the host's immune system against the tumor and have shown unprecedented durable remission for patients with cancers that were thought incurable, such as metastatic melanoma, metastatic renal cell carcinoma (RCC), microsatellite instability (MSI) high colorectal cancer and late stages of non-small cell lung cancer (NSCLC). However, about 80% of the patients fail to respond to these immunotherapies and are therefore left with other less effective and potentially toxic treatments. Identifying and understanding the mechanisms that enable cancerous cells to adapt to and eventually overcome therapy can help circumvent resistance and improve treatment. In this review, we describe the recent discoveries on the onco-immunological processes which govern the tumor microenvironment and their impact on the resistance to PD-1/PD-L1 checkpoint blockade.

Regulatory mechanisms of PD-1/PD-L1 in cancers

Immune evasion contributes to cancer growth and progression. Cancer cells have the ability to activate different immune checkpoint pathways that harbor immunosuppressive functions. The programmed death protein 1 (PD-1) and programmed cell death ligands (PD-Ls) are considered to be the major immune checkpoint molecules. The interaction of PD-1 and PD-L1 negatively regulates adaptive immune response mainly by inhibiting the activity of effector T cells while enhancing the function of immunosuppressive regulatory T cells (Tregs), largely contributing to the maintenance of immune homeostasis that prevents dysregulated immunity and harmful immune responses. However, cancer cells exploit the PD-1/PD-L1 axis to cause immune escape in cancer development and progression. Blockade of PD-1/PD-L1 by neutralizing antibodies restores T cells activity and enhances anti-tumor immunity, achieving remarkable success in cancer therapy. Therefore, the regulatory mechanisms of PD-1/PD-L1 in cancers have attracted an increasing attention. This article aims to provide a comprehensive review of the roles of the PD-1/PD-L1 signaling in human autoimmune diseases and cancers. We summarize all aspects of regulatory mechanisms underlying the expression and activity of PD-1 and PD-L1 in cancers, including genetic, epigenetic, post-transcriptional and post-translational regulatory mechanisms. In addition, we further summarize the progress in clinical research on the antitumor effects of targeting PD-1/PD-L1 antibodies alone and in combination with other therapeutic approaches, providing new strategies for finding new tumor markers and developing combined therapeutic approaches.

Clinical drug screening reveals clofazimine potentiates the efficacy while reducing the toxicity of anti-PD-1 and CTLA-4 immunotherapy

Emerging as the most potent and durable combinational immunotherapy, dual anti-PD-1 and CTLA-4 immune checkpoint blockade (ICB) therapy notoriously increases grade 3-5 immune-related adverse events (irAEs) in patients. Accordingly, attempts to improve the antitumor potency of anti-PD-1+CTLA-4 ICB by including additional therapeutics have been largely discouraged due to concerns of further increasing fatal toxicity. Here, we screened ∼3,000 Food and Drug Administration (FDA)-approved drugs and identified clofazimine as a potential third agent to optimize anti-PD-1+CTLA-4 ICB. Remarkably, clofazimine outperforms ICB dose reduction or steroid treatment in reversing lethality of irAEs, but unlike the detrimental effect of steroids on antitumor efficacy, clofazimine potentiates curative responses in anti-PD-1+CTLA-4 ICB. Mechanistically, clofazimine promotes E2F1 activation in CD8+ T cells to overcome resistance and counteracts pathogenic Th17 cells to abolish irAEs. Collectively, clofazimine potentiates the antitumor efficacy of anti-PD-1+CTLA-4 ICB, curbs intractable irAEs, and may fill a desperate clinical need to improve patient survival.

The C-type lectin DCIR contributes to the immune response and pathogenesis of colorectal cancer

Development and progression of malignancies are accompanied and influenced by alterations in the surrounding immune microenvironment. Understanding the cellular and molecular interactions between immune cells and cancer cells has not only provided important fundamental insights into the disease, but has also led to the development of new immunotherapies. The C-type lectin Dendritic Cell ImmunoReceptor (DCIR) is primarily expressed by myeloid cells and is an important regulator of immune homeostasis, as demonstrated in various autoimmune, infectious and inflammatory contexts. Yet, the impact of DCIR on cancer development remains largely unknown. Analysis of available transcriptomic data of colorectal cancer (CRC) patients revealed that high DCIR gene expression is associated with improved patients' survival, immunologically "hot" tumors and high immunologic constant of rejection, thus arguing for a protective and immunoregulatory role of DCIR in CRC. In line with these correlative data, we found that deficiency of DCIR1, the murine homologue of human DCIR, leads to the development of significantly larger tumors in an orthotopic murine model of CRC. This phenotype is accompanied by an altered phenotype of tumor-associated macrophages (TAMs) and a reduction in the percentage of activated effector CD4+ and CD8+ T cells in CRC tumors of DCIR1-deficient mice. Overall, our results show that DCIR promotes antitumor immunity in CRC, making it an attractive target for the future development of immunotherapies to fight the second deadliest cancer in the world.

The BTLA-HVEM complex - The future of cancer immunotherapy

The BTLA-HVEM complex plays a pivotal role in cancer and cancer immunotherapy by regulating immune responses. Dysregulation of BTLA and HVEM expression contributes to immunosuppression and tumor progression across various cancer types. Targeting the interaction between BTLA and HVEM holds promise for enhancing anti-tumor immune responses. Disruption of this complex presents a valuable avenue for advancing cancer immunotherapy strategies. Aberrant expression of BTLA and HVEM adversely affects immune cell function, particularly T cells, exacerbating tumor evasion mechanisms. Understanding and modulating the BTLA-HVEM axis represents a crucial aspect of designing effective immunotherapeutic interventions against cancer. Here, we summarize the current knowledge regarding the structure and function of BTLA and HVEM, along with their interaction with each other and various immune partners. Moreover, the expression of soluble and transmembrane forms of BTLA and HVEM in different types of cancer and their impact on the prognosis of patients is also discussed. Additionally, inhibitors of the proteins binding that might be used to block BTLA-HVEM interaction are reviewed. All the presented data highlight the plausible clinical application of BTLA-HVEM targeted therapies in cancer and autoimmune disease management. However, further studies are required to confirm the practical use of this concept. Despite the increasing number of reports on the BTLA-HVEM complex, many aspects of its biology and function still need to be elucidated. This review can be regarded as an encouragement and a guide to follow the path of BTLA-HVEM research.

Recent progress in combination therapy of oncolytic vaccinia virus

In recent years, oncolytic viruses have emerged as promising agents for treating various cancers. An oncolytic virus is a non-pathogenic virus that, due to genetic manipulation, tends to replicate in and cause lysis of cancerous cells while leaving healthy cells unaffected. Among these viruses, vaccinia virus is an attractive platform for use as an oncolytic platform due to its 190 Kb genome with a high capacity for encoding therapeutic payloads. Combining oncolytic VV therapy with other conventional cancer treatments has been shown to be synergistic and more effective than monotherapies. Additionally, OVV can be used as a vector to deliver therapeutic payloads, alone or in combination with other treatments, to increase overall efficacy. Here, we present a comprehensive analysis of preclinical and clinical studies that have evaluated the efficacy of oncolytic vaccinia viruses in cancer immunotherapy. We discuss the outcomes of these studies, including tumor regression rates, overall survival benefits, and long-term responses. Moreover, we provide insights into the challenges and limitations associated with oncolytic vaccinia virus- based therapies, including immune evasion mechanisms, potential toxicities, and the development of resistance.

Renal-clearable nanoprobes for optical imaging and early diagnosis of diseases

Optical imaging has played an indispensable role in clinical diagnostics and fundamental biomedical research due to its high sensitivity, high spatiotemporal resolution, cost-effectiveness, and easy accessibility. However, the issues of light scattering and low tissue penetration make them effective only for superficial imaging. To overcome these issues, renal-clearable optical nanoprobes have recently emerged, which are activated by abnormal disease-associated biomarkers and initiate a pharmacokinetic switch by undergoing degradation and eventually releasing signal reporters into urine, for simple imaging and sensitive optical in vitro urinalysis. In this review, we focus on the advancements of renal-clearable organic nanoprobes for optical imaging and remote urinalysis. The versatile design strategies of these nanoprobes are discussed along with their sensing mechanisms toward biomolecules of interest as well as their unique biological applications. Finally, challenges and perspectives are discussed to further advance the next-generation renal-clearable nanoprobes for in vivo imaging and in vitro urinalysis.

Cediranib enhances the transcription of MHC-I by upregulating IRF-1

Diminished or lost Major Histocompatibility Complex class I (MHC-I) expression is frequently observed in tumors, which obstructs the immune recognition of tumor cells by cytotoxic T cells. Restoring MHC-I expression by promoting its transcription and improving protein stability have been promising strategies for reestablishing anti-tumor immune responses. Here, through cell-based screening models, we found that cediranib significantly upregulated MHC-I expression in tumor cells. This finding was confirmed in various non-small cell lung cancer (NSCLC) cell lines and primary patient-derived lung cancer cells. Furthermore, we discovered cediranib achieved MHC-I upregulation through transcriptional regulation. interferon regulatory factor 1 (IRF-1) was required for cediranib induced MHC-I transcription and the absence of IRF-1 eliminated this effect. Continuing our research, we found cediranib triggered STAT1 phosphorylation and promoted IRF-1 transcription subsequently, thus enhancing downstream MHC-I transcription. In vivo study, we further confirmed that cediranib increased MHC-I expression, enhanced CD8+ T cell infiltration, and improved the efficacy of anti-PD-L1 therapy. Collectively, our study demonstrated that cediranib could elevate MHC-I expression and enhance responsiveness to immune therapy, thereby providing a theoretical foundation for its potential clinical trials in combination with immunotherapy.

The dopamine transporter antagonist vanoxerine inhibits G9a and suppresses cancer stem cell functions in colon tumors

Cancer stem cells (CSCs), functionally characterized by self-renewal and tumor-initiating activity, contribute to decreased tumor immunogenicity, while fostering tumor growth and metastasis. Targeting G9a histone methyltransferase (HMTase) effectively blocks CSC functions in colorectal tumors by altering pluripotent-like molecular networks; however, existing molecules directly targeting G9a HMTase activity failed to reach clinical stages due to safety concerns. Using a stem cell-based phenotypic drug-screening pipeline, we identified the dopamine transporter (DAT) antagonist vanoxerine, a compound with previously demonstrated clinical safety, as a cancer-specific downregulator of G9a expression. Here we show that gene silencing and chemical antagonism of DAT impede colorectal CSC functions by repressing G9a expression. Antagonizing DAT also enhanced tumor lymphocytic infiltration by activating endogenous transposable elements and type-I interferon response. Our study unveils the direct implication of the DAT-G9a axis in the maintenance of CSC populations and an approach to improve antitumor immune response in colon tumors.

Clinical and molecular features of acquired resistance to immunotherapy in non-small cell lung cancer

Although immunotherapy with PD-(L)1 blockade is routine for lung cancer, little is known about acquired resistance. Among 1,201 patients with non-small cell lung cancer (NSCLC) treated with PD-(L)1 blockade, acquired resistance is common, occurring in >60% of initial responders. Acquired resistance shows differential expression of inflammation and interferon (IFN) signaling. Relapsed tumors can be separated by upregulated or stable expression of IFNγ response genes. Upregulation of IFNγ response genes is associated with putative routes of resistance characterized by signatures of persistent IFN signaling, immune dysfunction, and mutations in antigen presentation genes which can be recapitulated in multiple murine models of acquired resistance to PD-(L)1 blockade after in vitro IFNγ treatment. Acquired resistance to PD-(L)1 blockade in NSCLC is associated with an ongoing, but altered IFN response. The persistently inflamed, rather than excluded or deserted, tumor microenvironment of acquired resistance may inform therapeutic strategies to effectively reprogram and reverse acquired resistance.

Prognostic value and immune landscapes of anoikis-associated lncRNAs in lung adenocarcinoma

BACKGROUND

Methods for predicting the outcome of lung adenocarcinoma (LUAD) in the clinic are limited. Anoikis is an important route to programmed cell death in LUAD, and the prognostic value of a model constructed with anoikis-related lncRNAs (ARlncRNAs) in LUAD is unclear.

METHODS

Transcriptome and basic information for LUAD patients was obtained from the Cancer Genome Atlas. Coexpression and Cox regression analyses were utilized to identify prognostically significant ARlncRNAs and construct a prognostic signature. Furthermore, the signature was combined with clinical characteristics to create a nomogram. Finally, we performed principal component, enrichment, tumor mutation burden (TMB), tumor microenvironment (TME) and drug sensitivity analyses to evaluate the basic research and clinical merit of the signature.

RESULTS

The prognostic signature developed with eleven ARlncRNAs can accurately predict that high-risk group patients have a worse prognosis, as proven by the receiver operating characteristic (ROC) curve (AUC: 0.718). Independent prognostic analyses indicated that the risk score is a significant independent prognostic element for LUAD (P<0.001). In the high-risk group, enrichment analysis demonstrated that glucose metabolism and DNA replication were the main enrichment pathways. TMB analysis indicated that the high-risk group had a high TMB (P<0.05). Drug sensitivity analyses can recognize drugs that are sensitive to different risk groups. Finally, 11 ARlncRNAs of this signature were verified by RT-qPCR analysis.

CONCLUSIONS

A novel prognostic signature developed with 11 ARlncRNAs can accurately predict the OS of LUAD patients and offer clinical guidance value for immunotherapy and chemotherapy treatment.

Inhibitor of PD-1/PD-L1: a new approach may be beneficial for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a globally prevalent, progressive disease with limited treatment options and poor prognosis. Because of its irreversible disease progression, IPF affects the quality and length of life of patients and imposes a significant burden on their families and social healthcare services. The use of the antifibrotic drugs pirfenidone and nintedanib can slow the progression of the disease to some extent, but it does not have a reverse effect on the prognosis. The option of lung transplantion is also limited owing to contraindications to transplantation, possible complications after transplantation, and the risk of death. Therefore, the discovery of new, effective treatment methods is an urgent need. Over recent years, various studies have been undertaken to investigate the relationship between interstitial pneumonia and lung cancer, suggesting that some immune checkpoints in IPF are similar to those in tumors. Immune checkpoints are a class of immunosuppressive molecules that are essential for maintaining autoimmune tolerance and regulating the duration and magnitude of immune responses in peripheral tissues. They can prevent normal tissues from being damaged and destroyed by the immune response. While current studies have focused on PD-1/PD-L1 and CTLA-4, PD-1/PD-L1 may be the only effective immune checkpoint IPF treatment. This review discusses the application of PD-1/PD-L1 checkpoint in IPF, with the aim of finding a new direction for IPF treatment.

Lymph node and tumor-associated PD-L1+ macrophages antagonize dendritic cell vaccines by suppressing CD8+ T cells

Current immunotherapies provide limited benefits against T cell-depleted tumors, calling for therapeutic innovation. Using multi-omics integration of cancer patient data, we predict a type I interferon (IFN) responseHIGH state of dendritic cell (DC) vaccines, with efficacious clinical impact. However, preclinical DC vaccines recapitulating this state by combining immunogenic cancer cell death with induction of type I IFN responses fail to regress mouse tumors lacking T cell infiltrates. Here, in lymph nodes (LNs), instead of activating CD4+/CD8+ T cells, DCs stimulate immunosuppressive programmed death-ligand 1-positive (PD-L1+) LN-associated macrophages (LAMs). Moreover, DC vaccines also stimulate PD-L1+ tumor-associated macrophages (TAMs). This creates two anatomically distinct niches of PD-L1+ macrophages that suppress CD8+ T cells. Accordingly, a combination of PD-L1 blockade with DC vaccines achieves significant tumor regression by depleting PD-L1+ macrophages, suppressing myeloid inflammation, and de-inhibiting effector/stem-like memory T cells. Importantly, clinical DC vaccines also potentiate T cell-suppressive PD-L1+ TAMs in glioblastoma patients. We propose that a multimodal immunotherapy and vaccination regimen is mandatory to overcome T cell-depleted tumors.

Immunoediting Dynamics in Glioblastoma: Implications for Immunotherapy Approaches

Glioblastoma is an aggressive primary brain tumor that poses many therapeutic difficulties because of the high rate of proliferation, genetic variability, and its immunosuppressive microenvironment. The theory of cancer immunoediting, which includes the phases of elimination, equilibrium, and escape, offers a paradigm for comprehending interactions between the immune system and glioblastoma. Immunoediting indicates the process by which immune cells initially suppress tumor development, but thereafter select for immune-resistant versions leading to tumor escape and progression. The tumor microenvironment (TME) in glioblastoma is particularly immunosuppressive, with regulatory T cells and myeloid-derived suppressor cells being involved in immune escape. To achieve an efficient immunotherapy for glioblastoma, it is crucial to understand these mechanisms within the TME. Existing immunotherapeutic modalities such as chimeric antigen receptor T cells and immune checkpoint inhibitors have been met with some level of resistance because of the heterogeneous nature of the immune response to glioblastoma. Solving these issues is critical to develop novel strategies capable of modulating the TME and re-establishing normal immune monitoring. Further studies should be conducted to identify the molecular and cellular events that underlie the immunosuppressive tumor microenvironment in glioblastoma. Comprehending and modifying the stages of immunoediting in glioblastoma could facilitate the development of more potent and long-lasting therapies.

Prognostic Significance of CONUT Score in Elderly NSCLC

PURPOSE

This study evaluated the Controlling Nutritional Status (CONUT) score as a prognostic predictor in elderly non-small cell lung cancer (NSCLC) patients with surgical resection.

METHODS

Overall, 114 patients over 80 years old undergoing curative resection for NSCLC were retrospectively analyzed. Receiver operating characteristic (ROC) analysis was conducted to evaluate the capacity of immune-inflammatory markers to predict overall survival (OS). Cox-proportional hazards regression analysis was implemented to investigate prognostic markers for OS.

RESULTS

Based on ROC curves, the CONUT score was found to be the most valuable prognostic marker (area under the curve = 0.716). The high CONUT (≥2) group included 54 patients, and the low CONUT (0 or 1) group included 60 patients. The high CONUT group had poorer prognosis rates compared to the low CONUT group with regard to OS (5-year OS: 46.3% vs. 86.0%, p = 0.0006). In the multivariate data analysis, histology, lymphatic invasion, and CONUT score (hazard ratio: 4.23, p = 0.0003) were found to be exclusive and independent prognostic markers for OS.

CONCLUSION

Preoperatively, the CONUT score can be used as a novel prognostic marker in elderly NSCLC patients. CONUT evaluations can also be used to design nutritional interventions to improve patient outcomes.

Integration of bioinformatics and machine learning strategies identifies APM-related gene signatures to predict clinical outcomes and therapeutic responses for breast cancer patients

BACKGROUND

Tumor antigenicity and efficiency of antigen presentation jointly influence tumor immunogenicity, which largely determines the effectiveness of immune checkpoint blockade (ICB). However, the role of altered antigen processing and presentation machinery (APM) in breast cancer (BRCA) has not been fully elucidated.

METHODS

A series of bioinformatic analyses and machine learning strategies were performed to construct APM-related gene signatures to guide personalized treatment for BRCA patients. A single-sample gene set enrichment analysis (ssGSEA) algorithm and weighted gene co-expression network analysis (WGCNA) were combined to screen for BRCA-specific APM-related genes. The non-negative matrix factorization (NMF) algorithm was used to divide the cohort into different clusters and the fgsea algorithm was applied to investigate the altered signaling pathways. Random survival forest (RSF) and the least absolute shrinkage and selection operator (Lasso) Cox regression analysis were combined to construct an APM-related risk score (APMrs) signature to predict overall survival. Furthermore, a nomogram and decision tree were generated to improve predictive accuracy and risk stratification for individual patients. Based on Tumor Immune Dysfunction and Exclusion (TIDE) method, random forest (RF) and Lasso logistic regression model were combined to establish an APM-related immunotherapeutic response score (APMis). Finally, immune infiltration, immunomodulators, mutational patterns, and potentially applicable drugs were comprehensively analyzed in different APM-related risk groups. IHC staining was used to assess the expression of APM-related genes in clinical samples.

RESULTS

In this study, APMrs and APMis showed favorable performances in risk stratification and therapeutic prediction for BRCA patients. APMrs exhibited more powerful prognostic capacity and accurate survival prediction compared to conventional clinicopathological features. APMrs was closely associated with distinct mutational patterns, immune cell infiltration and immunomodulators expression. Furthermore, the two APM-related gene signatures were independently validated in external cohorts with prognosis or immunotherapeutic responses. Potential applicable drugs and targets were mined in the APMrs-high group. APM-related genes were further validated in our in-house samples.

CONCLUSION

The APM-related gene signatures established in our study could improve the personalized assessment of survival risk and guide ICB decision-making for BRCA patients.

BRAF D594A mutation defines a unique biological and immuno-modulatory subgroup associated with functional CD8+ T cell infiltration in colorectal cancer

BACKGROUND

BRAF non-V600 mutation occupies a relatively small but critical subset in colorectal cancer (CRC). However, little is known about the biological functions and impacts of BRAF class III mutation in CRC. Here, we aim to explore how D594A mutation impacts on biological behaviors and immune related signatures in murine CRC cells.

METHODS

BRAF V600E (class I), G469V (class II) and D594A (class III) mutant cell lines were established based on MC38 cells. The biological behaviors of cells were evaluated in respect of cell growth, cell proliferation, cell apoptosis, cell migration and invasion by the methods of colony-forming assay, CCK-8 assay, Annexin V/PI staining and transwell assay. The concentrations of soluble cytokines were detected by ELISA. The membrane expression of immuno-modulatory molecules and the pattern of tumor infiltrating lymphocyte were evaluated by flow cytometry. The molecular mechanism was explored by RNA sequencing. Immunohistochemistry (IHC) staining was used for the detection of CD8α in tumor tissues. qRT-PCR and western blot were performed to assess the mRNA and protein expression. Anti-PD-L1 treatment and cytokines neutralization experiments were conducted in in vivo models.

RESULTS

D594A mutant cells displayed lower grade malignancy characteristics than V600E (class I) and G469V (class II) mutant cells. Meanwhile, D594A mutation led to evident immuno-modulatory features including upregulation of MHC Class I and PD-L1. In vivo experiments displayed that the frequency of infiltrated CD8+ T cells was significantly high within D594A mutant tumors, which may provide potential response to anti-PD-L1 therapy. RNA sequencing analysis showed that D594A mutation led to enhanced expression of ATF3 and THBS1, which thus facilitated CXCL9 and CXCL10 production upon IFN-γ treatment. In addition, CXCL9 or CXCL10 neutralization reduced the infiltration of CD8+ T cells into THBS1-overexpressing tumors.

CONCLUSIONS

D594A mutant CRC exhibited lower aggressiveness and immune-activated phenotype. ATF3-THBS1-CXCL9/CXCL10 axis mediated functional CD8+ T cells infiltration into the microenvironment of D594A mutant CRC. Our present study is helpful to define this mutation in CRC and provide important insights in designing effective immunotherapeutic strategies in clinic.