Coordinated regulation of myeloid cells by tumours. Nat Rev Immunol. 2012;12:253-268. [PMID: 22437938 DOI: 10.1038/nri3175]

Intranuclear TCA and mitochondrial overload: The nascent sprout of tumors metabolism

Abnormal glucose metabolism in tumors is a well-known form of metabolic reprogramming in tumor cells, the most representative of which, the Warburg effect, has been widely studied and discussed since its discovery. However, contradictions in a large number of studies and suboptimal efficacy of drugs targeting glycolysis have prompted us to further deepen our understanding of glucose metabolism in tumors. Here, we review recent studies on mitochondrial overload, nuclear localization of metabolizing enzymes, and intranuclear TCA (nTCA) in the context of the anomalies produced by inhibition of the Warburg effect. We provide plausible explanations for many of the contradictory points in the existing studies, including the causes of the Warburg effect. Furthermore, we provide a detailed prospective discussion of these studies in the context of these new findings, providing new ideas for the use of nTCA and mitochondrial overload in tumor therapy.

The multifaceted roles of macrophages in the transition from hepatitis to hepatocellular carcinoma: From mechanisms to therapeutic strategies

Macrophages are central to the progression from hepatitis to hepatocellular carcinoma (HCC), with their remarkable plasticity and ability to adapt to the changing liver microenvironment. Chronic inflammation, fibrosis, and ultimately tumorigenesis are driven by macrophage activation, making them key regulators of liver disease progression. This review explores the diverse roles of macrophages in the transition from hepatitis to HCC. In the early stages of hepatitis, macrophages are essential for pathogen clearance and tissue repair. However, chronic activation leads to prolonged inflammation, which exacerbates liver damage and promotes fibrosis. As the disease progresses to liver fibrosis, macrophages interact with hepatic stellate cells, fostering a pro-tumorigenic microenvironment that supports HCC development. In hepatocarcinogenesis, macrophages contribute to tumor initiation, growth, metastasis, immune evasion, cancer stem cell maintenance, and angiogenesis. Their functional plasticity enables them to adapt to the tumor microenvironment, thereby promoting tumor progression and resistance to therapy. Targeting macrophages represents a promising strategy for preventing and treating HCC. Therapeutic approaches, including reprogramming macrophage phenotypes to enhance anti-tumor immunity, blocking macrophage recruitment and activation, and utilizing nanoparticle-based drug delivery systems, may provide new avenues for combating HCC by modulating macrophage functions and tumor microenvironment dynamics.

A One Stone Three Birds Paradigm of Photon-Driven Pyroptosis Dye for Amplifying Tumor Immunotherapy

Activating the pyroptosis pathway of tumor cells by photodynamic therapy (PDT) for immunogenic cell death (ICD) is considered a valid strategy in pursuit of antitumor immunotherapy, but it remains a huge challenge due to the lack of reliable design guidelines. Moreover, it is often overlooked that conventional PDT can exacerbate the development of tumor immunosuppressive microenvironment, which is apparently unfavorable to clinical immunotherapy. The endoplasmic reticulum's (ER) pivotal role in cellular homeostasis and its emerging link to pyroptosis have galvanized interest in ER-centric imaging and therapeutics. Herein, using the targeted group-assisted strategy (TAGS), an intriguing cyclooxygenase-2-targeted photodynamic conjugate, Indo-Cy, strategically created, which exploits the enzyme's overabundance in the tumoral ER, especially under proinflammatory hypoxic conditions. This conjugate, with its highly precise ER imaging, embodies a trifunctional strategy: i) innovating an electron transfer mechanism, converting the hemicyanine moiety into an oxygen-independent type I photosensitizer, thereby navigating around the hypoxia constraints of traditional PDT; ii) executing precise ER-targeted PDT, amplifying caspase-1/GSDMD-mediated pyroptosis for ICD; 3) attenuating immunosuppressive pathways by inhibiting cyclooxygenase-2 downstream factors, including HIF-1α, PGE2, and VEGF. Indo-Cy's multimodal approach potently induces in vivo tumor pyroptosis and bolsters antitumor immunity, underscoring cyclooxygenase-2-targeted dyes' potential as a versatile oncotherapeutics.

Timp2 loss-of-function mutation and TIMP2 treatment in a murine model of NSCLC: Modulation of immunosuppression and oncogenic signaling

Mounting evidence suggests that the tissue inhibitor of metalloproteinases-2 (TIMP2) can reduce tumor burden and metastasis. However, the demonstration of such anti-tumor activity and associated mechanisms using in vivo tumor models is lacking. The effects of a Timp2 functional mutation and administration of recombinant TIMP2 were examined in both orthotopic and heterotopic murine models of lung cancer using C57Bl/6 syngeneic Lewis Lung 2-luciferase 2 cells (LL2-Luc2) cells. Mice harboring a functional mutation of TIMP2 (mT2) display markedly increased primary lung tumor growth, increased mortality, enriched vasculature, and enhanced infiltration of pro-tumorigenic, immunosuppressive myeloid cells. Treatment with recombinant TIMP2 reduced primary tumor growth in both mutant and wild-type (wt) mice. Comparison of transcriptional profiles of lung tissues from tumor-free, wt versus mT2 mice reveals only minor changes. However, lung tumor-bearing mice of both genotypes demonstrate significant genotype-dependent changes in gene expression following treatment with TIMP. In tumor-bearing wt mice, TIMP2 treatment reduced the expression of upstream oncogenic mediators, whereas treatment of mT2 mice resulted in an immunomodulatory phenotype. A heterotopic subcutaneous model generating metastatic pulmonary tumors demonstrated that daily administration of recombinant TIMP2 significantly reduces the expression of heat shock proteins, suggesting a reduction of cell-stress responses. In summary, we describe how TIMP2 exerts novel, anti-tumor effects in a murine model of lung cancer and that rTIMP2 treatment supports a normalizing effect on the tumor microenvironment. Our findings show that TIMP2 treatment demonstrates significant potential as an adjuvant in the treatment of NSCLC.

The lactate receptor HCAR1 drives the recruitment of immunosuppressive PMN-MDSCs in colorectal cancer

Most patients with colorectal cancer do not achieve durable clinical benefits from immunotherapy, underscoring the existence of alternative immunosuppressive mechanisms. Here we found that activation of the lactate receptor HCAR1 signaling pathway induced the expression of chemokines CCL2 and CCL7 in colorectal tumor cells, leading to the recruitment of immunosuppressive CCR2+ polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) to the tumor microenvironment. Ablation of Hcar1 in mice with colorectal tumors significantly decreased the abundance of tumor-infiltrating CCR2+ PMN-MDSCs, enhanced the activation of CD8+ T cells and, consequently, reduced tumor burden. We detected immunosuppressive CCR2+ PMN-MDSCs in tumor specimens from individuals with colorectal and other cancers. The US Food and Drug Administration-approved drug reserpine suppressed lactate-mediated HCAR1 activation, impaired the recruitment of CCR2+ PMN-MDSCs, boosted CD8+ T cell-dependent antitumor immunity and sensitized immunotherapy-resistant tumors to programmed cell death protein 1 antibody therapy in mice with colorectal tumors. Altogether, we described HCAR1-driven recruitment of CCR2+ PMN-MDSCs as a mechanism of immunosuppression.

Antitumor host immunity enhanced by near-infrared photoimmunotherapy

Near-infrared photoimmunotherapy (NIR-PIT) is a novel antitumor therapy that selectively kills cancer cells by NIR light-triggered photochemical reaction of IRDye700DX within Ab-photoabsorber conjugates (APCs). NIR-PIT induces immunogenic cell death, causing immune cell migration between the tumor and tumor-draining lymph nodes, and expanding multiclonal tumor-infiltrating CD8+ T cells. Crucially, the cytotoxic effects of NIR-PIT are limited to cancer cells, sparing immune cells such as antigen-presenting cells and T cells, which are key players in boosting antitumor host immunity. By modifying the Ab used in APC synthesis, NIR-PIT can be repurposed to target and deplete noncancerous immunosuppressive cells including regulatory T cells, myeloid-derived suppressor cells, and cancer-associated fibroblasts in the tumor microenvironment. Immunosuppressive cell targeted NIR-PIT strongly potentiates antitumor host immunity, including the induction of abscopal effects and the development of immune memory. Furthermore, antitumor immune responses and therapeutic efficacy are synergistically enhanced when NIR-PIT is combined with other immune-activating treatments, such as interleukin-15 and immune checkpoint inhibitors. These new findings make NIR-PIT a valuable tool in the evolving landscape of cancer immunotherapy. This review explains the role of NIR-PIT in activating antitumor host immunity.

Roux-en-Y gastric bypass-associated fecal tyramine promotes colon cancer risk via increased DNA damage, cell proliferation, and inflammation

BACKGROUND

Fecal abundances of Enterobacteriaceae and Enterococcaceae are elevated in patients following Roux-en-Y gastric bypass (RYGB) surgery. Concurrently, fecal concentrations of tyramine, derived from gut bacterial metabolism of tyrosine and/or food, increased post-RYGB. Furthermore, emerging evidence suggests that RYGB is associated with increased colorectal cancer (CRC) risk. However, the causal link between RYGB-associated microbial metabolites and CRC risk remains unclear. Hence, this study investigated the tyrosine metabolism of Enterobacteriaceae and Enterococcaceae strains isolated from patients post-RYGB and explored the causal effects of tyramine on the CRC risk and tumorigenesis using both human colonic cancer cell line (HCT 116) and wild-type and ApcMin/+ mice.

RESULTS

We isolated 31 bacterial isolates belonging to Enterobacteriaceae and Enterococcaceae families from the feces of patients with RYGB surgery. By culturing the isolates in tyrosine-supplemented medium, we found that Citrobacter produced phenol as a main product of tyrosine, whereas Enterobacter and Klebsiella produced 4-hydroxyphenylacetate, Escherichia produced 4-hydroxyphenyllactate and 4-hydroxyphenylpyruvate, and Enterococcus and two Klebsiella isolates produced tyramine. These observations suggested the gut bacterial contribution to increased fecal concentrations of tyramine post-RYGB. We subsequently evaluated the impact of tyramine on CRC risk and development. Tyramine induced necrosis and promoted cell proliferation and DNA damage of HCT 116 cells. Daily oral administration of tyramine for 49 days to wild-type mice resulted in visible adenomas in 5 out of 12 mice, accompanied by significantly enhanced DNA damage (γH2AX +) and an increased trend of cell proliferation (Ki67 +) in the ileum, along with an upregulated expression of the cell division cycle gene (Cdc34b) in the colon. To evaluate the impact of tyramine on intestinal tumor growth, we treated ApcMin/+ mice with the same doses of tyramine and duration. These mice showed larger colonic tumor size and increased intestinal cell proliferation and inflammation (e.g., increased mRNA expression of IL-17A and higher number of Ly6G + neutrophils) compared to water-treated ApcMin/+ control mice.

CONCLUSIONS

Our results collectively suggested that RYGB-associated fecal bacteria could contribute to tyramine production and tyramine increased CRC risk by increasing DNA damage, cell proliferation, and pro-inflammatory responses of the gut. Monitoring and modulating tyramine concentrations in high-risk individuals could aid CRC prognosis and management. Video Abstract.

Peripheral blood proteome biomarkers distinguish immunosuppressive features of cancer progression

Immune status critically affects cancer progression and therapy responses. This study aimed to identify plasma proteome changes in immunosuppressive cancer and potential biomarkers predicting systemic immunosuppression. Mouse models of syngeneic breast tumors (benign 67NR and malignant 4T1) were used to collect plasma samples. Plasma samples from naive mice and both early- and late-stage tumor-bearing mice were subjected to liquid chromatography-mass spectrometry (LC-MS) analysis. 4T1-bearing mice showed systemic immunosuppression characterized by significant generation of myeloid-derived suppressor cells (MDSCs) as early as 7 days after tumor implantation, unlike 67NR tumors. LC-MS identified 1086 proteins across the five experimental groups, with 27 proteins showing group-specific expression in 4T1 blood compared with 67NR blood. Immune-related proteins osteopontin, lactotransferrin, calreticulin, and peroxiredoxin 2 were selected as potential biomarkers of MDSC-producing breast cancer. These markers were expressed in cancer cells or MDSC in the 4T1 model, and osteopontin and peroxiredoxin 2 were associated with low survival probability and high recurrence in patients with triple-negative breast cancer. Our findings suggest that MDSC-producing immunosuppressive cancers have unique plasma proteomes, offering additional insights into cancer immune status.

Coactivation of innate immune suppressive cells induces acquired resistance against combined TLR agonism and PD-1 blockade

Immune checkpoint blockade therapy has been successfully applied in clinical settings as a standard therapy for many cancer types, but its clinical efficacy is restricted to patients with immunologically hot tumors. Various strategies to modify the tumor microenvironment (TME), such as Toll-like receptor (TLR) agonists that can stimulate innate immunity, have been explored but have not been successful. Here, we show a mechanism of acquired resistance to combination treatment consisting of an agonist for multiple TLRs, OK-432 (Picibanil), and programmed cell death protein 1 (PD-1) blockade. Adding the TLR agonist failed to convert the TME from immunogenically cold to hot and did not augment antitumor immunity, particularly CD8+ T cell responses, in multiple animal models. The failure was attributed to the coactivation of innate suppressive cells, such as polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) expressing CXCR2, through high CXCL1 production by macrophages in the TME upon OK-432 treatment. A triple combination treatment with OK-432, PD-1 blockade, and a CXCR2 neutralizing antibody overcame the resistance induced by PMN-MDSCs, resulting in a stronger antitumor effect than that of any dual combinations or single treatments. The accumulation of PMN-MDSCs was similarly observed in the pleural effusions of patients with lung cancer after OK-432 administration. We propose that successful combination cancer immunotherapy intended to stimulate innate antitumor immunity requires modulation of unwanted activation of innate immune suppressive cells, including PMN-MDSCs.

CDKN2A Low cancer cells outcompete macrophages for microenvironmental zinc to drive immunotherapy resistance

Approximately 50% of cancers exhibit decreased CDKN2A expression ( CDKN2A Low ), which is linked to immune checkpoint blockade (ICB) resistance. While CDKN2A is traditionally recognized as a tumor suppressor and cell cycle regulator, we have previously put forth a new paradigm demonstrating its role in intracellular metabolic reprogramming. Whether the metabolic derangement due to CDKN2A loss alters metabolites within the tumor microenvironment (TME) and how that affects the immune compartment and ICB response has never been investigated. Here we found that CDKN2A Low cancer cells reorganize zinc compartmentalization by upregulating the zinc importer SLC39A9 in the plasma membrane, leading to intracellular zinc accumulation in cancer cells and concurrent zinc depletion in the TME. This competition for zinc results in zinc-starved macrophages, leading to reduced phagocytic activity. Remarkably, restoring zinc levels in the TME through a dietary intervention re-educates macrophages to a pro-phagocytic phenotype, sensitizing CDKN2A Low tumors to ICB. Unexpectedly, T cells are not required for this response. Clinically, macrophages from CDKN2A Low cancer patients have decreased zinc signatures, corresponding to reduced phagocytosis signatures. Moreover, patients with low circulating zinc levels have reduced time-to-event outcomes compared to those with higher zinc levels. Our work reveals a previously unrecognized mechanism through which CDKN2A Low cancer cells outcompete macrophages for zinc, directly disrupting their function and ICB efficacy.

Machine learning model using immune indicators to predict outcomes in early liver cancer

BACKGROUND

Patients with early-stage hepatocellular carcinoma (HCC) generally have good survival rates following surgical resection. However, a subset of these patients experience recurrence within five years post-surgery.

AIM

To develop predictive models utilizing machine learning (ML) methods to detect early-stage patients at a high risk of mortality.

METHODS

Eight hundred and eight patients with HCC at Beijing Ditan Hospital were randomly allocated to training and validation cohorts in a 2:1 ratio. Prognostic models were generated using random survival forests and artificial neural networks (ANNs). These ML models were compared with other classic HCC scoring systems. A decision-tree model was established to validate the contribution of immune-inflammatory indicators to the long-term outlook of patients with early-stage HCC.

RESULTS

Immune-inflammatory markers, albumin-bilirubin scores, alpha-fetoprotein, tumor size, and International Normalized Ratio were closely associated with the 5-year survival rates. Among various predictive models, the ANN model generated using these indicators through ML algorithms exhibited superior performance, with a 5-year area under the curve (AUC) of 0.85 (95%CI: 0.82-0.88). In the validation cohort, the 5-year AUC was 0.82 (95%CI: 0.74-0.85). According to the ANN model, patients were classified into high-risk and low-risk groups, with an overall survival hazard ratio of 7.98 (95%CI: 5.85-10.93, P < 0.0001) between the two cohorts.

CONCLUSION

A non-invasive, cost-effective ML-based model was developed to assist clinicians in identifying high-risk early-stage HCC patients with poor postoperative prognosis following surgical resection.

H3.3-G34R Mutation-Mediated Epigenetic Reprogramming Leads to Enhanced Efficacy of Immune Stimulatory Gene Therapy in Diffuse Hemispheric Gliomas

Diffuse hemispheric glioma (DHG), H3 G34-mutant, representing 9-15% of cases, are aggressive Central Nervous System (CNS) tumors with poor prognosis. This study examines the role of epigenetic reprogramming of the immune microenvironment and the response to immune-mediated therapies in G34-mutant DHG. To this end, we utilized human G34-mutant DHG biopsies, primary G34-mutant DHG cultures, and genetically engineered G34-mutant mouse models (GEMMs). Our findings show that the G34 mutation alters histone marks' deposition at promoter and enhancer regions, leading to the activation of the JAK/STAT pathway, which in turn results in an immune-permissive tumor microenvironment. The implementation of Ad-TK/Ad-Flt3L immunostimulatory gene therapy significantly improved median survival, and lead to over 50% long term survivors. Upon tumor rechallenge in the contralateral hemisphere without any additional treatment, the long-term survivors exhibited robust anti-tumor immunity and immunological memory. These results indicate that immune-mediated therapies hold significant potential for clinical translation in treating patients harboring H3.3-G34 mutant DHGs, offering a promising strategy for improving outcomes in this challenging cancer subtype affecting adolescents and young adults (AYA).

STATEMENT OF SIGNIFICANCE

This study uncovers the role of the H3.3-G34 mutation in reprogramming the tumor immune microenvironment in diffuse hemispheric gliomas. Our findings support the implementation of precision medicine informed immunotherapies, aiming at improving enhanced therapeutic outcomes in adolescents and young adults harboring H3.3-G34 mutant DHGs.

Therapeutic targeting of cGAS-STING pathway in lung cancer

The presence of DNA in the cytosol triggers a protective response from the innate immune system. Cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) is an essential cytosolic DNA sensor that triggers a potent innate immune response. As a result of this signaling cascade reaction, type I interferon and other immune mediators activate an immune response. The cGAS-STING pathway has great anticancer immunity-boosting potential since it produces type I interferons. The detection of double-stranded DNA (dsDNA) in response to various stimuli initiates a protective host's cGAS-STING signals. So, it is clear that a substantial relationship is expected between cancer biotherapy and the functioning of the cGAS-STING pathway. Several STING agonists with promising outcomes have been created for preclinical cancer therapy research. Notably, immunotherapy has dramatically extended patient survival and radically altered the course of lung cancer treatment, particularly in more advanced instances. However, this method is still ineffective for a large number of lung cancer patients. cGAS-STING can overcome resistance and boost anticancer immunity by stimulating the activity of many pro-inflammatory mediators, augmenting dendritic cell cross-presentation, and initiating a tumor-specific CD8+ T cell response. This review aims to present the most recent results on the functionality of the cGAS-STING pathway in cancer progression and its potential as an immunotherapy target, with a focus on lung cancer.

CXCL16/CXCR6/TGF-β Feedback Loop Between M-MDSCs and Treg Inhibits Anti-Bacterial Immunity During Biofilm Infection

Staphylococcus aureus (S. aureus) is a leading cause of Periprosthetic  joint  infection (PJI), a severe complication after joint arthroplasty. Immunosuppression is a major factor contributing to the infection chronicity of S. aureus PJI, posing significant treatment challenges. This study investigates the relationship between the immunosuppressive biofilm milieu and S. aureus PJI outcomes in both discovery and validation cohorts. This scRNA-seq analysis of synovium from PJI patients reveals an expansion and heightened activity of monocyte-related myeloid-derived suppressor cells (M-MDSCs) and regulatory T cells (Treg). Importantly, CXCL16 is significantly upregulated in M-MDSCs, with its corresponding CXCR6 receptor also elevated on Treg. M-MDSCs recruit Treg and enhance its activity via CXCL16-CXCR6 interactions, while Treg secretes TGF-β, inducing M-MDSCs proliferation and immunosuppressive activity. Interfering with this cross-talk in vivo using Treg-specific CXCR6 knockout PJI mouse model reduces M-MDSCs/Treg-mediated immunosuppression and alleviates bacterial burden. Immunohistochemistry and recurrence analysis show that PJI patients with CXCR6high synovium have poor prognosis. This findings highlight the critical role of CXCR6 in Treg in orchestrating an immunosuppressive microenvironment and biofilm persistence during PJI, offering potential targets for therapeutic intervention.

Rbfox3 Promotes Transformation of MDSC-Like Tumor Cells to Shape Immunosuppressive Microenvironment

Myeloid-derived suppressor cells (MDSCs) within the tumor microenvironment (TME) contribute to the malignant progression of tumors by exerting immunosuppressive effects. Bacterial lipopolysaccharides (LPS) have been widely demonstrated in various types of solid tumors. LPS can promote the malignant progression of tumors, which mechanism has not yet been fully elucidated. In this study, a type of MDSC-like tumor cells (MLTCs) is found in tumor tissues induced by low-dose and long-term LPS stimulation. MLTCs can simultaneously express tumor cell and MDSCs markers. Similar to MDSCs, MLTCs can produce arginine, nitric oxide, and reactive oxygen species and inhibit the activity of NK and T cells to promote the formation of an immunosuppressive microenvironment. MLTCs can also promote tumor cell proliferation and vasculogenic mimicry formation. CRISPR-Cas9 activity screening studies identified RNA-binding Fox-1 homolog 3 (Rbfox3) as a critical protein for MLTCs formation after LPS treatment. Rbfox3 can transcriptionally regulate the expression of Ass1 in the form of phase-separated particles. Crocin can inhibit the generation of MLTCs by disrupting phase-separated particles of Rbfox3 and enhance the anti-tumor effects of immune checkpoint inhibitors (ICIs).

Trained immunity in chronic inflammatory diseases and cancer

A decade after the term 'trained immunity' (TRIM) was coined to reflect the long-lasting hyper-responsiveness of innate immune cells with an epigenetically imprinted 'memory' of earlier stimuli, our understanding has broadened to include the potential implications of TRIM in health and disease. Here, after summarizing the well-documented beneficial effects of TRIM against infections, we discuss emerging evidence that TRIM is also a major underlying mechanism in chronic inflammation-related disorders such as periodontitis, rheumatoid arthritis and cardiovascular disease. Furthermore, mounting evidence indicates that the induction of TRIM by certain agonists confers protective antitumour responses. Although the mechanisms underlying TRIM require further study, the current knowledge enables the experimental development of innovative therapeutic approaches to stimulate or inhibit TRIM in a context-appropriate manner, such as the stimulation of TRIM in cancer or its inhibition in inflammatory disorders.

Adaptive Immunity Determines the Cancer Treatment Outcome of Oncolytic Virus and Anti-PD-1

The immune checkpoint inhibitor, anti-programmed death protein-1 (anti-PD-1), enhances adaptive immunity to kill tumor cells, and the oncolytic virus (OV) triggers innate immunity to clear the infected tumor cells. We create a mathematical model to investigate how the interaction between adaptive and innate immunities under OV and anti-PD-1 affects tumor reduction. For different immunity strength, we create the corresponding virtual baseline patients and cohort patients to decipher the major factors determining the treatment outcome. Global sensitivity analysis indicates that adaptive immunity has more control on the treatment outcome than innate immunity, and whether anti-PD-1 cancels out the OV treatment efficacy depends on the OV dosage and the balance between clearance of infected tumor cells and OV by T cells. The optimal OV infection rate and dosage suggest that OV treatment is more sensitive to adaptive immunity than innate immunity. Our model prediction also indicates that tumor reduction is more sensitive to anti-PD-1 efficacy as adaptive immunity becomes stronger, and anti-PD-1 trends to cancel out the OV treatment efficacy as innate immunity becomes stronger. Based on these results, the recommended treatment protocol for patients with different immunity strength can be determined.

Targeting HGF/c-MET signaling to regulate the tumor microenvironment: Implications for counteracting tumor immune evasion

The hepatocyte growth factor (HGF) along with its receptor (c-MET) are crucial in preserving standard cellular physiological activities, and imbalances in the c-MET signaling pathway can lead to the development and advancement of tumors. It has been extensively demonstrated that immune checkpoint inhibitors (ICIs) can result in prolonged remission in certain patients. Nevertheless, numerous preclinical studies have shown that MET imbalance hinders the effectiveness of anti-PD-1/PD-L1 treatments through various mechanisms. Consequently, clarifying the link between the c-MET signaling pathway and the tumor microenvironment (TME), as well as uncovering the effects of anti-MET treatment on ICI therapy, is crucial for enhancing the outlook for tumor patients. In this review, we examine the impact of abnormal activation of the HGF/c-MET signaling pathway on the control of the TME and the processes governing PD-L1 expression in cancer cells. The review thoroughly examines both clinical and practical evidence regarding the use of c-MET inhibitors alongside PD-1/PD-L1 inhibitors, emphasizing that focusing on c-MET with immunotherapy enhances the effectiveness of treating MET tumors exhibiting elevated PD-L1 expression.

Improving systemic delivery of oncolytic virus by cellular carriers

Oncolytic virotherapy (OVT) is a promising option for cancer treatment. OVT involves selective oncolytic virus (OV) replication within cancer cells, which triggers anti-tumor responses and immunostimulation. Despite promising potential, OVT faces critical challenges, including insufficient tumor-specific targeting, which results in limited tumor penetration and variability in therapeutic efficacy. These challenges are particularly pronounced in solid tumors with complex microenvironments and heterogeneous vascularization. A comprehensive research program is currently underway to develop and refine innovative delivery methods to address these issues to enhance OVT precision and efficacy. A principal area of investigation is the utilization of cellular carriers to enhance the delivery and distribution of OVs within tumor microenvironments, thereby optimizing immune system activation and maximizing anti-tumor effects. This review offers a comprehensive overview of the current strategies that are being used to enhance the delivery of OVs via cellular carriers with the goal of improving the clinical impact of OVT in cancer therapy.

The mycobiome in human cancer: analytical challenges, molecular mechanisms, and therapeutic implications

The polymorphic microbiome is considered a new hallmark of cancer. Advances in High-Throughput Sequencing have fostered rapid developments in microbiome research. The interaction between cancer cells, immune cells, and microbiota is defined as the immuno-oncology microbiome (IOM) axis. Fungal microbes (the mycobiome), although representing only ∼ 0.1-1% of the microbiome, are a critical immunologically active component of the tumor microbiome. Accumulating evidence suggests a possible involvement of commensal and pathogenic fungi in cancer initiation, progression, and treatment responsiveness. The tumor-associated mycobiome mainly consists of the gut mycobiome, the oral mycobiome, and the intratumoral mycobiome. However, the role of fungi in cancer remains poorly understood, and the diversity and complexity of analytical methods make it challenging to access this field. This review aims to elucidate the causal and complicit roles of mycobiome in cancer development and progression while highlighting the issues that need to be addressed in executing such research. We systematically summarize the advantages and limitations of current fungal detection and analysis methods. We enumerate and integrate these recent findings into our current understanding of the tumor mycobiome, accompanied by the prospect of novel and exhilarating clinical implications.

Harnessing the tumor microenvironment: targeted cancer therapies through modulation of epithelial-mesenchymal transition

The tumor microenvironment (TME) is integral to cancer progression, impacting metastasis and treatment response. It consists of diverse cell types, extracellular matrix components, and signaling molecules that interact to promote tumor growth and therapeutic resistance. Elucidating the intricate interactions between cancer cells and the TME is crucial in understanding cancer progression and therapeutic challenges. A critical process induced by TME signaling is the epithelial-mesenchymal transition (EMT), wherein epithelial cells acquire mesenchymal traits, which enhance their motility and invasiveness and promote metastasis and cancer progression. By targeting various components of the TME, novel investigational strategies aim to disrupt the TME's contribution to the EMT, thereby improving treatment efficacy, addressing therapeutic resistance, and offering a nuanced approach to cancer therapy. This review scrutinizes the key players in the TME and the TME's contribution to the EMT, emphasizing avenues to therapeutically disrupt the interactions between the various TME components. Moreover, the article discusses the TME's implications for resistance mechanisms and highlights the current therapeutic strategies toward TME modulation along with potential caveats.

The Discovery of a Novel AXL/Triple Angiokinase Inhibitor Based on 6-Chloro-Substituted Indolinone and Side Chain Methyl Substitution Inhibiting Pancreatic Cancer Growth and Metastasis

In this study, we discovered and identified a novel AXL/triple angiokinase inhibitor 11b by rational structural modification based on the structure of triple angiokinase inhibitor Nintedanib. We found that 11b potently inhibited AXL expression with the IC50 value of 3.75 nM and possessed similar inhibitory activity on KDR as Nintedanib. In the assay of antiproliferative activity on NIH/3T3, HUVEC, Bxpc-3, and MDA-MB-231, 11b showed better inhibitory ability than Nintedanib. In pancreatic cancer xenograft mouse models from Bxpc-3 cells, even when the dosage was halved, 11b exhibited better or comparable effects to Nintedanib (tumor growth inhibition (TGI) based on tumor volume change during the trial or tumor weight). Notably, we also found that 11b prohibited Bxpc-3 resulted lung metastasis by inhibiting its epithelial-mesenchymal transition (EMT) process. Another mechanism assay also proved that 11b inhibited the function of blood vessels and fibroblasts, promoted apoptosis of cancer and fibroblast cells, and exhibited low toxicity and good metabolic stability.

Immune-cell signatures of persistent inflammation, immunosuppression, and catabolism syndrome after sepsis

BACKGROUND

Management of persistent inflammation, immunosuppression, and catabolism syndrome (PICS) after sepsis remains challenging for patients in the intensive care unit, experiencing poor quality of life and death. However, immune-cell signatures in patients with PICS after sepsis remain unclear.

METHODS

We determined immune-cell signatures of PICS after sepsis at single-cell resolution. Murine cecal ligation and puncture models of PICS were applied for validation.

FINDINGS

Immune functions of two enriched monocyte subpopulations, Mono1 and Mono4, were suppressed substantially in patients with sepsis and were partially restored in patients with PICS after sepsis and exhibited immunosuppressive and pro-apoptotic effects on B and CD8T cells. Patients with PICS and sepsis had reduced naive and memory B cells and proliferated plasma cells. Besides, naive and memory B cells in patients with PICS showed an active antigen processing and presentation gene signature compared to those with sepsis. PICS patients with better prognoses exhibited more active memory B cells and IGHA1-plasma cells. CD8TEMRA displayed signs of proliferation and immune dysfunction in the PICS-death group in contrast with the PICS-alive group. Megakaryocytes proliferation was more pronounced in patients with PICS and sepsis than in healthy controls, with notable changes in the anti-inflammatory and immunomodulatory effects observed in patients with PICS and verified in mice models.

CONCLUSIONS

Our study evaluated PICS after sepsis at the single-cell level, identifying the heterogeneity present within immune-cell subsets, facilitating the prediction of disease progression and the development of effective intervention.

FUNDING

This work was supported by the National Natural Science Foundation of China, Shanghai Municipal Health Commission "Yiyuan New Star" Youth Medical Talent Cultivating Program, and Shanghai Clinical Research Center for Anesthesiology.

Recent developments in myeloid immune modulation in cancer therapy

Myeloid cells play a crucial dual role in cancer progression and response to therapy, promoting tumor growth, enabling immune suppression, and contributing to metastatic spread. The ability of these cells to modulate the immune system has made them attractive targets for therapeutic strategies aimed at shifting their function from tumor promotion to fostering antitumor immunity. Therapeutic approaches targeting myeloid cells focus on modifying their numbers, genetics, metabolism, and interactions within the tumor microenvironment. These strategies aim to reverse their suppressive functions and redirect them to support antitumor immune responses by inhibiting immunosuppressive pathways, targeting specific receptors, and promoting their differentiation into less immunosuppressive phenotypes. Here, we discuss recent approaches to clinically target tumor myeloid cells, focusing on reprogramming myeloid cells to promote antitumor immunity.

Immune Microenvironment in Breast Cancer Metastasis

Metastatic disease is the final stage of breast cancer that accounts for vast majority of patient death. Mounting data over recent years strongly support the critical roles of the immune microenvironment in determining breast cancer metastasis. The latest single-cell studies provide further molecular evidence illustrating the heterogeneity of this immune microenvironment. This chapter summarizes major discoveries on the role of various immune cells in metastasis progression and discusses future research opportunities. Studies investigating immune heterogeneity within primary breast cancer and across different metastasis target organs can potentially lead to more precise treatment strategies with improved efficacy.

Cryoablation synergizes with anti-PD-1 immunotherapy induces an effective abscopal effect in murine model of cervical cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs), especially anti-PD-1/PD-L1 antibodies, have emerged as promising therapeutic options for cervical cancer. However, the efficacy of anti-PD-1 antibody monotherapy is limited. Cryoablation could elicit an anti-tumor immune response, thereby presenting itself as a potential approach to augment the response of ICIs. The aim of our study was to investigate the systemic immunological effects of cryoablation and the potential synergistic anti-tumor effects of cryoablation and anti-PD-1 antibody in cervical cancer.

METHODS

We established U14 murine bilateral subcutaneous cervical cancer model, wherein the primary tumors were treated with cryoablation. Flow cytometry, immunohistochemistry and RNA-seq were used to analyze the immune cell infiltration and immune-associated pathways in the secondary tumor.

RESULTS

Our study revealed that cryoablation reprogrammed the immune landscape, leading to an enhanced infiltration of CD8+ T cell in distant tumors. Cryoablation created a conducive environment for increasing the efficacy of anti-PD-1 immunotherapy. Cryoablation in combination with anti-PD-1 antibody inhibited distant tumors growth and improved mouse survival. Mechanistically, this combination therapy could augment the infiltration of CD8+ T cells, CD4+ T cells, dendritic cells and M1-like tumor-associated macrophages, enhance multiple aspects of antitumor immune response, and reduce immunosuppressive cells such as M2-like tumor-associated macrophages and myeloid-derived suppressor cells in distant tumors.

CONCLUSIONS

Combination therapy with cryoablation and anti-PD-1 antibody induces an effective abscopal effect in murine model of cervical cancer and may be a novel therapeutic approach for patients with advanced/recurrent cervical cancer.

Pre-radiation Nivolumab plus ipilimumab in patients with newly diagnosed high-grade gliomas

The limited success of immune checkpoint inhibitors (ICIs) in the adjuvant setting for glioblastoma highlights the need to explore administering ICIs prior to immunosuppressive radiation. To address the feasibility and safety of this approach, we conducted a phase I study in patients with newly diagnosed Grade 3 and Grade 4 gliomas. Patients received nivolumab 300 mg every 2 weeks and ipilimumab 1 mg/kg every 6 weeks until disease progression or unacceptable toxicity. Fifteen patients were treated, with four patients on dexamethasone at treatment initiation and five tumors having MGMT promoter methylated. Treatment began a median of 38 days post-surgery. The most common treatment-related adverse events (AEs) were rash, pruritus, fatigue, nausea, and anorexia. Grade 3 AEs were lipase increased (n = 2), anorexia (n = 1), pruritus (n = 1), and rash (n = 3), and one Grade 4 cerebral edema occurred. Median progression-free survival (mPFS) was 1.3 months and median overall survival (mOS) was 19.3 months (95% CI, 12.9-NA). Three patients deferred conventional radiochemotherapy for over seven months while ten eventually received it. Progressing tumors tended to exhibit higher LAG-3 levels at baseline compared to shrinking tumors. Analysis of paired pre-treatment and post-progression tissue (n = 5) showed trends of up-regulated TGF-β, ERBB2, ERBB3, and ERBB4 signaling pathways, downregulated PPAR signaling, decreased B cell proportions, and increased monocytes proportions in tumors post-treatment. We show nivolumab plus ipilimumab can be safely administered prior to standard radiotherapy for newly diagnosed gliomas and is operationally feasible. Clinicaltrials.gov NCT03425292 registered February 7, 2018.

Tumor microenvironment in primary central nervous system lymphoma (PCNSL)

Primary central nervous system lymphoma (PCNSL) is one of the rare lymphomas limited to the central nervous system. With the availability of immunotherapy, the tumor microenvironment (TME) attracts much attention nowadays. However, the systematic studies on the TME of PCNSL are lacking. By reviewing the existing research, we found that the TME of PCNSL is infiltrated with abundant TAMs and TILs, among which cytotoxic T cells (CTLs) and M2-polarized macrophages are principal. However, the counts of immune cells infiltrated in the TME of PCNSL are significantly lower than systemic diffuse large B-cell lymphoma (DLBCL). In addition, PCNSL can attract the infiltration of immunosuppressive cells and the loss of HLA I/II expression, overexpress inhibitory immune checkpoints, and release immunosuppressive cytokines to form an immunosuppressive TME. The immunosuppressive effect of TME in PCNSL is significantly stronger than that in systemic DLBCL. These characteristics of TME highlight the immunosuppression of PCNSL.

Patterns of immune evasion in triple-negative breast cancer and new potential therapeutic targets: a review

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of progesterone and estrogen receptors and low (or absent) HER2 expression. TNBC accounts for 15-20% of all breast cancers. It is associated with younger age, a higher mutational burden, and an increased risk of recurrence and mortality. Standard treatment for TNBC primarily relies on cytotoxic agents, such as taxanes, anthracyclines, and platinum compounds for both early and advanced stages of the disease. Several targeted therapies, including bevacizumab and sunitinib, have failed to demonstrate significant clinical benefit in TNBC. The emergence of immune checkpoint inhibitors (ICI) has revolutionized cancer treatment. By stimulating the immune system, ICIs induce a durable anti-tumor response across various solid tumors. TNBC is a particularly promising target for treatment with ICIs due to the higher levels of tumor-infiltrating lymphocytes (TIL), increased PD-L1 expression, and higher mutational burden, which generates tumor-specific neoantigens that activate immune cells. ICIs administered as monotherapy in advanced TNBC yields only a modest response; however, response rates significantly improve when ICIs are combined with cytotoxic agents, particularly in tumors expressing PD-L1. Pembrolizumab is approved for use in both early and advanced TNBC in combination with standard chemotherapy. However, more research is needed to identify more potent biomarkers, and to better elucidate the synergism of ICIs with other targeted agents. In this review, we explore the challenges of immunotherapy in TNBC, examining the mechanisms of tumor progression mediated by immune cells within the tumor microenvironment, and the signaling pathways involved in both primary and acquired resistance. Finally, we provide a comprehensive overview of ongoing clinical trials underway to investigate novel immune-targeted therapies for TNBC.

Neutrophil diversity and function in health and disease

Neutrophils, the most abundant type of granulocyte, are widely recognized as one of the pivotal contributors to the acute inflammatory response. Initially, neutrophils were considered the mobile infantry of the innate immune system, tasked with the immediate response to invading pathogens. However, recent studies have demonstrated that neutrophils are versatile cells, capable of regulating various biological processes and impacting both human health and disease. Cytokines and other active mediators regulate the functional activity of neutrophils by activating multiple receptors on these cells, thereby initiating downstream signal transduction pathways. Dysfunctions in neutrophils and disruptions in neutrophil homeostasis have been implicated in the pathogenesis of numerous diseases, including cancer and inflammatory disorders, often due to aberrant intracellular signaling. This review provides a comprehensive synthesis of neutrophil biological functions, integrating recent advancements in this field. Moreover, it examines the biological roles of receptors on neutrophils and downstream signaling pathways involved in the regulation of neutrophil activity. The pathophysiology of neutrophils in numerous human diseases and emerging therapeutic approaches targeting them are also elaborated. This review also addresses the current limitations within the field of neutrophil research, highlighting critical gaps in knowledge that warrant further investigation. In summary, this review seeks to establish a comprehensive and multidimensional model of neutrophil regulation, providing new perspectives for potential clinical applications and further research.

Interferon regulatory factor 8-driven reprogramming of the immune microenvironment enhances antitumor adaptive immunity and reduces immunosuppression in murine glioblastoma

BACKGROUND

Glioblastoma (GBM) has a highly immunosuppressive tumor immune microenvironment (TIME), largely mediated by myeloid-derived suppressor cells (MDSCs). Here, we utilized a retroviral replicating vector (RRV) to deliver Interferon Regulatory Factor 8 (IRF8), a master regulator of type 1 conventional dendritic cell (cDC1) development, in a syngeneic murine GBM model. We hypothesized that RRV-mediated delivery of IRF8 could "reprogram" intratumoral MDSCs into antigen-presenting cells and thereby restore T-cell responses.

METHODS

Effects of RRV-IRF8 on survival and tumor growth kinetics were examined in the SB28 murine GBM model. The immunophenotype was analyzed by flow cytometry and gene expression assays. We assayed functional immunosuppression and antigen presentation by ex vivo T-cell-myeloid co-culture.

RESULTS

Intratumoral injection of RRV-IRF8 in mice bearing intracerebral SB28 glioma significantly suppressed tumor growth and prolonged survival. RRV-IRF8 treated tumors exhibited significant enrichment of cDC1s and CD8+ T-cells. Additionally, myeloid cells derived from RRV-IRF8 tumors showed decreased expression of the immunosuppressive markers Arg1 and IDO1 and demonstrated reduced suppression of naïve T-cell proliferation in ex vivo co-culture, compared to controls. Furthermore, DCs from RRV-IRF8 tumors showed increased antigen presentation compared to those from control tumors. In vivo treatment with azidothymidine (AZT), a viral replication inhibitor, showed that IRF8 transduction in both tumor and non-tumor cells is necessary for survival benefit, associated with a reprogrammed, cDC1- and CD8 T-cell-enriched TIME.

CONCLUSIONS

Our results indicate that reprogramming of glioma-infiltrating myeloid cells by in vivo expression of IRF8 may reduce immunosuppression and enhance antigen presentation, achieving improved tumor control.

Myeloid-derived suppressor cells in cancer: Current knowledge and future perspectives

MDSCs (myeloid-derived suppressor cells) are crucial for immune system evasion in cancer. They accumulate in peripheral blood and tumor microenvironment, suppressing immune cells like T-cells, natural killer cells and dendritic cells. They promote tumor angiogenesis and metastasis by secreting cytokines and growth factors and contribute to a tumor-promoting environment. The accumulation of MDSCs in cancer patients has been linked to poor prognosis and resistance to various cancer therapies. Targeting MDSCs and their immunosuppressive mechanisms may improve treatment outcomes and enhance immune surveillance by developing drugs that inhibit MDSC function, by preventing their accumulation and by disrupting the tumor-promoting environment. This review presents a detailed overview of the MDSC research in cancer with regulation of their development and function. The relevance of MDSC as a prognostic and predictive biomarker in different types of cancers, along with recent advancements on the therapeutic approaches to target MDSCs are discussed in detail.

Natural lung-tropic TH9 cells: a sharp weapon for established lung metastases

BACKGROUND

Lung metastasis remains the primary cause of tumor-related mortality, with limited treatment options and unsatisfactory efficacy. In preclinical studies, T helper 9 (TH9) cells have shown promise in treating solid tumors. However, it is unclear whether TH9 cells can tackle more challenging situations, such as established lung metastases. Moreover, comprehensive exploration into the nuanced biological attributes of TH9 cells is imperative to further unravel their therapeutic potential.

METHODS

We adoptively transferred TH1, TH9, and TH17 cells into subcutaneous, in situ, and established lung metastases models of osteosarcoma and triple-negative breast cancer, respectively, comparing their therapeutic efficacy within each distinct model. We employed flow cytometry and an in vivo imaging system to evaluate the accumulation patterns of TH1, TH9, and TH17 cells in the lungs after transfusion. We conducted bulk RNA sequencing on in vitro differentiated TH9 cells to elucidate the chemokine receptor CXCR4, which governs their heightened pulmonary tropism relative to TH1 and TH17 cell counterparts. Using Cd4 cre Cxcr4 flox/flox mice, we investigate the effects of CXCR4 on the lung tropism of TH9 cells. We performed mass spectrometry to identify the E3 ligase responsible for CXCR4 ubiquitination and elucidated the mechanism governing CXCR4 expression within TH9 cellular milieu. Ultimately, we analyzed the tumor immune composition after TH9 cell transfusion and evaluated the therapeutic efficacy of adjunctive anti-programmed cell death protein-1 (PD-1) therapy in conjunction with TH9 cells.

RESULTS

In this study, we provide evidence that TH9 cells exhibit higher lung tropism than TH1 and TH17 cells, thereby exhibiting exceptional efficacy in combating established lung metastases. CXCR4-CXCL12 axis is responsible for lung tropism of TH9 cells as ablating CXCR4 in CD4+ T cells reverses their lung accumulation. Mechanistically, tumor necrosis factor receptor-associated factor 6 (TRAF6)-driven hyperactivation of NF-κB signaling in TH9 cells inhibited ITCH-mediated ubiquitination of CXCR4, resulting in increased CXCR4 accumulation and enhanced lung tropism of TH9 cells. Besides, TH9 cells' transfusion significantly improved the immunosuppressed microenvironment. TH9 cells and anti-PD-1 exhibit synergistic effects in tumor control.

CONCLUSIONS

Our findings emphasized the innate lung tropism of TH9 cells driven by the activation of TRAF6, which supports the potential of TH9 cells as a promising therapy for established lung metastases.

A theranostic photosensitizer-conjugated albumin co-loading with resiquimod for cancer-targeted imaging and robust photo-immunotherapy

Cancer immunotherapy remains a low immune response rate in clinic because of dominant immunosuppressive tumor microenvironment (TME) and lack of effective drug to specifically remodel the TME. In this work, we introduced a tumor-seeking human serum albumin (HSA) based delivery platform by covalently conjugating with a tumor-targeting near-infrared (NIR) photosensitizer (IR-DBI) and non-covalently loading of immune modulator Resiquimod (R848). HSA exhibited tumor-preferential accumulation after covalent conjugation with IR-DBI. Meanwhile, HSA restricted the rotation of IR-DBI, narrowed the HOMO-LUMO energy gap, significantly enhanced fluorescent intensity and dual-modal phototherapy (PTT/PDT). The enhanced phototherapeutic effect further induced robust ICD effect. More importantly, non-covalent loading of R848 could be released from HSA at tumor sites by laser irradiation-induced heat. The in-situ release of R848 in TME efficiently promoted the maturation of DC cells and repolarized M2 macrophages to M1 macrophages. Consequently, robust photo-induced antitumor immunity was triggered in the different mice models bearing primary and distant tumors or lung metastasis, which was further enhanced by combining with CTLA-4 blockade therapy. Taken together, this work may present a versatile albumin composite which exhibits tumor-preferential accumulation and imaging-guided PDT/PTT/immunotherapy.

Host ANGPTL2 establishes an immunosuppressive tumor microenvironment and resistance to immune checkpoint therapy

Use of immune checkpoint inhibitors (ICIs) as cancer immunotherapy has advanced rapidly in the clinic; however, mechanisms underlying resistance to ICI therapy, including impaired T cell infiltration, low immunogenicity, and tumor "immunophenotypes" governed by the host, remain unclear. We previously reported that in some cancer contexts, tumor cell-derived angiopoietin-like protein 2 (ANGPTL2) has tumor-promoting functions. Here, we asked whether ANGPTL2 deficiency could enhance antitumor ICI activity in two inflammatory contexts: a murine syngeneic model of colorectal cancer and a mouse model of high-fat diet (HFD)-induced obesity. Systemic ANGPTL2 deficiency potentiated ICI efficacy in the syngeneic model, supporting an immunosuppressive role for host ANGPTL2. Relevant to the mechanism, we found that ANGPTL2 induces pro-inflammatory cytokine production in adipose tissues, driving generation of myeloid-derived suppressor cells (MDSCs) in bone marrow and contributing to an immunosuppressive tumor microenvironment and resistance to ICI therapy. Moreover, HFD-induced obese mice showed impaired responsiveness to ICI treatment, suggesting that obesity-induced chronic inflammation facilitated by high ANGPTL2 expression blocks ICI antitumor effects. Our findings overall provide novel insight into protumor ANGPTL2 functions and illustrate the essential role of the host system in ICI responsiveness.

A key regulator of tumor-associated neutrophils: the CXCR2 chemokine receptor

In recent years, with the advance of research, the role of tumor-associated neutrophils (TANs) in tumors has become a research hotspot. As important effector cells in the innate immune system, neutrophils play a key role in the immune and inflammatory responses of the body. As the first line of defense against bacterial and fungal infections, neutrophils have the ability to kill invading pathogens. In the pathological state of malignant tumors, the phenotype of neutrophils is altered and has an important regulatory function in tumor development. The C-X-C motif chemokine receptor 2(CXCR2) is a key molecule that mediates the migration and aggregation signaling pathway of immune cells, especially neutrophils. This review focuses on the regulation of CXCR2 on TANs in the process of tumorigenesis and development, and emphasizes the application significance of CXCR2 inhibitors in blocking the migration of TANs to tumors.

Colorectal cancer with BRAF V600E mutation: Trends in immune checkpoint inhibitor treatment

Colorectal cancer (CRC) with BRAF V600E mutation presents a formidable scientific and clinical challenge due to its aggressive nature and poor response to standard therapeutic approaches. BRAF V600E mutation-induced conspicuous activation of the MAPK pathway contributes to the relentless tumor progression. Nevertheless, the efficacy of multi-targeted MAPK pathway inhibition remains suboptimal in clinical practice. Patients with high microsatellite instability (MSI-H) have shown favorable results with immune checkpoint inhibitors (ICIs). The combination of the MAPK pathway inhibition with ICIs has recently emerged as a promising regimen to improve clinical outcomes in the microsatellite stable (MSS) subgroup of BRAF V600E-mutant metastatic CRC patients. In this review, we elucidate the unique tumor biology of BRAF V600E-mutant CRC, with a particular focus on the immune features underlying the rationale for ICI treatments in the MSI-H and MSS subpopulations, then highlight the trends in clinical trials of the ICI therapy for BRAF V600E-mutant metastatic CRC.

CAR-armored-cell therapy in solid tumor treatment

Over the past decade, chimeric antigen receptor (CAR)-T cell therapy has emerged as a revolutionary immunotherapeutic approach to combat cancer. This therapy constructs a CAR on the surface of T cells through genetic engineering techniques. The CAR is formed from a combination of antibody-derived or ligand-derived domains and T-cell receptor (TCR) domains. This enables T cells to specifically bind to and activate against tumor cells. However, the efficacy of CAR-T cells in solid tumors remains inconclusive due to several challenges such as poor tumor trafficking, infiltration, and the immunosuppressive tumor microenvironment (TME). In response, CAR natural killer (CAR-NK) and CAR macrophages (CAR-M) have been developed as complementary strategies for solid tumors. CAR-NK cells do not require HLA compatibility, demonstrate reduced toxicity, and are thus seen as potential substitutes for CAR-T cells. Furthermore, CAR-M immunotherapy is also being researched and has shown phagocytic capabilities and tumor-antigen presentation. This study discusses the features, advantages, and limitations of CAR-T, CAR-NK, and CAR-M cells in the treatment of solid tumors and suggests prospective solutions for enhancing the efficacy of CAR host-cell-based immunotherapy.

BAP1 inactivation promotes lactate production by leveraging the subcellular localization of LDHA in melanoma

BRCA1-associated protein 1 (BAP1) acts as a tumor suppressor and can affect the cell cycle, tumor immunity, and cellular metabolism through multiple pathways. In melanoma, BAP1 mutations promote tumor cell glycolysis, leading to increased lactate production. The tumor microenvironment with high lactate levels is often associated with immunosuppression and tumor progression. The inhibitory effect of BAP1 on glycolysis has been found in a variety of tumors, but the specific mechanism by which BAP1 inhibits lactate production still needs to be elucidated. In this study, we show that BAP1 can interact directly with lactate dehydrogenase (LDHA), causing LDHA to accumulate in the nucleus. Conversely, BAP1 deletion leads to the accumulation of LDHA in the cytoplasm, catalyzing the production of lactate from pyruvate that results in increased lactate levels inside and outside the cell. By elucidating the interaction between BAP1 and LDHA and the subsequent effects on lactate production in melanoma cells, this work provides insights into the mechanism of BAP1-mediated metabolic regulation. Furthermore, it may provide novel directions for the clinical treatment of BAP1-mutant melanoma.

Comparing neoantigen cancer vaccines and immune checkpoint therapy unveils an effective vaccine and anti-TREM2 macrophage-targeting dual therapy

The goal of therapeutic cancer vaccines and immune checkpoint therapy (ICT) is to promote T cells with anti-tumor capabilities. Here, we compared mutant neoantigen (neoAg) peptide-based vaccines with ICT in preclinical models. NeoAg vaccines induce the most robust expansion of proliferating and stem-like PD-1+TCF-1+ neoAg-specific CD8 T cells in tumors. Anti-CTLA-4 and/or anti-PD-1 ICT promotes intratumoral TCF-1- neoAg-specific CD8 T cells, although their phenotype depends in part on the specific ICT used. Anti-CTLA-4 also prompts substantial changes to CD4 T cells, including induction of ICOS+Bhlhe40+ T helper 1 (Th1)-like cells. Although neoAg vaccines or ICTs expand iNOS+ macrophages, neoAg vaccines maintain CX3CR1+CD206+ macrophages expressing the TREM2 receptor, unlike ICT, which suppresses them. TREM2 blockade enhances neoAg vaccine efficacy and is associated with fewer CX3CR1+CD206+ macrophages and induction of neoAg-specific CD8 T cells. Our findings highlight different mechanisms underlying neoAg vaccines and different forms of ICT and identify combinatorial therapies to enhance neoAg vaccine efficacy.

Cell-cell interactions mediating primary and metastatic breast cancer dormancy

Breast cancer remains one of the leading causes of death in women around the world. A majority of deaths from breast cancer occur due to cancer cells colonizing distant organ sites. When colonizing these distant organ sites, breast cancer cells have been known to enter into a state of dormancy for extended periods of time. However, the mechanisms that promote dormancy as well as dormant-to-proliferative switch are not fully understood. The tumor microenvironment plays a key role in mediating cancer cell phenotype including regulation of the dormant state. In this review, we highlight cell-cell interactions in the tumor microenvironment mediating breast cancer dormancy at the primary and metastatic sites. Specifically, we describe how immune cells from the lymphoid lineage, tumor-associated myeloid lineage cells, and stromal cells of non-hematopoietic origin as well as tissue resident stromal cells impact dormancy vs. proliferation in breast cancer cells as well as the associated mechanisms. In addition, we highlight the importance of developing model systems and the associated considerations that will be critical in unraveling the mechanisms that promote primary and metastatic breast cancer dormancy mediated via cell-cell interactions.

Multifaceted Aspects of Dysfunctional Myelopoiesis in Cancer and Therapeutic Perspectives with Focus on HCC

Myelopoiesis provides for the formation and continued renewal of cells belonging primarily to the innate immune system. It is a highly plastic process that secures the response to external and internal stimuli to face acute and changing needs. Infections and chronic diseases including cancer can modulate it by producing several factors, impacting proliferation and differentiation programs. While the lymphocytic compartment has attracted major attention due to the role of adaptive immunity in anticancer immune response, in recent years, research has found convincing evidence that confirms the importance of innate immunity and the key function played by emergency myelopoiesis. Due to cancer's ability to manipulate myelopoiesis to its own advantage, the purpose of this review is to outline myelopoiesis processes within the tumor microenvironment and suggest possible therapeutic lines of research to restore the physiological functioning of the host's immune system, with a special outlook on hepatocellular carcinoma (HCC).

FCGBP functions as a tumor suppressor gene in head and neck squamous cell carcinoma

PURPOSE

The pathogenesis of head and neck squamous cell carcinoma (HNSCC) was complex and the overall survival was not satisfying. It was urgent to uncover novel molecules that play vital role in HNSCC for disease monitoring and drug development.

METHODS

Distinguished expression of FCGBP mRNA in HNSCC was analyzed by TCGA-HNSC and three GEO datasets, the relationship between FCGBP and clinical stage and survival was analyzed by GEPIA 2, the immune infiltration pattern analysis was conducted by TIMER 2.0, pathways affected by FCGBP was conducted by GSEA and GO/KEGG. In vitro experiments (including qRT-PCR, siRNA transfection, CCK8, transwell assay and flow cytometry) were conducted to confirm bioinformatic analysis.

RESULTS

FCGBP was down-regulated in tumor samples compared with normal tissues at both mRNA and protein levels, and positively correlated with survival in HNSCC. Genes co-expressed with FCGBP were mainly enriched in immune-related biological processes and pathways. GSEA indicated that FCGBP was associated with activated immune reaction and inhibiting well-known pro-tumor pathways. GSE41613 validated FCGBP as an independent prognostic marker for HNSCC and FCGBP was down-regulated in HNSCC cell lines by qRT-PCR. Migration and invasion of SCC9 and CAL27 were enhanced by FCGBP-targeting siRNAs, the ratio of cytotoxic T lymphocytes were down-regulated while the ratio of myeloid-derived suppressor cells were increased by FCGBP-targeting siRNAs.

CONCLUSION

FCGBP was a tumor suppressor gene and was an independent prognostic marker for better survival. The underlying mechanism may be that FCGBP inhibited tumor migration and invasion and activated immune response against tumor cells.

Targeting mitochondria: restoring the antitumor efficacy of exhausted T cells

Immune checkpoint blockade therapy has revolutionized cancer treatment, but resistance remains prevalent, often due to dysfunctional tumor-infiltrating lymphocytes. A key contributor to this dysfunction is mitochondrial dysfunction, characterized by defective oxidative phosphorylation, impaired adaptation, and depolarization, which promotes T cell exhaustion and severely compromises antitumor efficacy. This review summarizes recent advances in restoring the function of exhausted T cells through mitochondria-targeted strategies, such as metabolic remodeling, enhanced biogenesis, and regulation of antioxidant and reactive oxygen species, with the aim of reversing the state of T cell exhaustion and improving the response to immunotherapy. A deeper understanding of the role of mitochondria in T cell exhaustion lays the foundation for the development of novel mitochondria-targeted therapies and opens a new chapter in cancer immunotherapy.

Targeting Myeloid Cells in Head and Neck Squamous Cell Carcinoma: A Kinase Inhibitor Library Screening Approach

Head and neck squamous cell carcinoma (HNSCC) is highly enriched with tumor-infiltrating myeloid cells, including tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs). However, effective therapeutic agents targeting tumor-associated myeloid cells in HNSCC are currently lacking. Here, we employed a unique co-culture system to investigate how HNSCC cells affect tumor-associated myeloid cells. We found that the presence of cancer cells significantly enhances myeloid cell proliferation and promotes TAM differentiation. To identify potential therapeutic agents, we screened a custom library of 70 kinase inhibitors to assess their effects on distinct subsets of tumor-associated myeloid cells. We discovered specific inhibitors that differentially suppressed the populations of TAMs, monocytic MDSCs (M-MDSCs), or polymorphonuclear MDSCs (PMN-MDSCs), suggesting that inhibiting different targets could reduce distinct subsets of tumor-associated myeloid cells. Conversely, some inhibitors were found to increase the population of CD11b+Ly6G-Ly6C- myeloid cells. Among the promising inhibitors tested, vatalanib, a VEGF-R inhibitor, demonstrated significant in vivo efficacy at inhibiting tumor growth and reducing tumor-associated myeloid cells, thereby underscoring its potential as a therapeutic agent. Our findings highlight specific kinase inhibitors with differential modulatory effects on HNSCC-associated myeloid subsets and caution the application of some as anti-cancer drugs. This experimental system may provide a robust platform for identifying new agents targeting tumor-associated myeloid cells in HNSCC and beyond, and for elucidating mechanistic insights into tumor-myeloid cell interaction.

Exploring the role of Fusobacterium nucleatum in colorectal cancer: implications for tumor proliferation and chemoresistance

Fusobacterium nucleatum (Fn) has been extensively studied for its connection to colorectal cancer (CRC) and its potential role in chemotherapy resistance. Studies indicate that Fn is commonly found in CRC tissues and is associated with unfavorable prognosis and treatment failure. It has been shown that Fn promotes chemoresistance by affecting autophagy, a cellular process that helps cells survive under stressful conditions. Additionally, Fn targets specific signaling pathways that activate particular microRNAs and modulate the response to chemotherapy. Understanding the current molecular mechanisms and investigating the importance of Fn-inducing chemoresistance could provide valuable insights for developing novel therapies. This review surveys the role of Fn in tumor proliferation, metastasis, and chemoresistance in CRC, focusing on its effects on the tumor microenvironment, gene expression, and resistance to conventional chemotherapy drugs. It also discusses the therapeutic implications of targeting Fn in CRC treatment and highlights the need for further research.

Natural products: promising therapeutics for targeting regulatory immune cells in the tumor microenvironment

Regulatory immune cells regulate immune responses through various mechanisms, affecting the occurrence, development, and therapeutic effects of tumors. In this article, we reviewed the important roles of regulatory immune cells, such as regulatory T cells (Tregs), regulatory B cells (Bregs), myeloid-derived suppressor cells (MDSCs), regulatory dendritic cells (DCregs), and tumor-associated macrophages (TAMs), in the tumor microenvironment (TME). The immunomodulatory effects of natural products, such as polysaccharides, polyphenols, glycosides, alkaloids, terpenoids, quinones, and other compounds, which affect the functions of regulatory immune cells through molecular signaling pathways, thereby enhancing the potential of the antitumor immune response, are discussed. These findings provide new ideas and possibilities for the application of natural products in tumor treatment, which can help enhance the effectiveness of tumor treatment and improve patient prognosis.

Comparison of multiple machine learning models for predicting prognosis of pancreatic ductal adenocarcinoma based on contrast-enhanced CT radiomics and clinical features

Objective

The aim of this study was to evaluate the prognostic potential of combining clinical features and radiomics with multiple machine learning (ML) algorithms in pancreatic ductal adenocarcinoma (PDAC).

Methods

A total of 116 patients with PDAC who met the eligibility criteria were randomly assigned to a training or validation cohort. Seven ML algorithms, including Supervised Principal Components, stepwise Cox, Random Survival Forest, CoxBoost, Least absolute shrinkage and selection operation (Lasso), Ridge, and Elastic network, were integrated into 43 algorithm combinations. Forty-three radiomics models were constructed separately using radiomics features extracted from arterial phase (AP), venous phase (VP), and combined arterial and venous phase (AP+VP) images. The concordance index (C-index) of each model was calculated. The model with the highest mean C-index was identified as the best model for calculating the radiomics score (Radscore). Univariate and multivariate Cox analyses were used to identify independent prognostic indicators and create a clinical model for prognosis prediction. The multivariable Cox regression was used to combine Radscore with clinical features to create a combined model. The efficacy of the model was evaluated using the C-index, calibration curves, and decision curve analysis (DCA).

Results

The model based on the Lasso+StepCox[both] algorithm constructed using AP+VP radiomics features showed the best predictive ability among the 114 radiomics models. The C-indices of the model in the training and validation cohorts were 0.742 and 0.722, respectively. Based on the results of the univariate and multivariate Cox regression analyses, sex, Tumor-Node-Metastasis (TNM) stage, and systemic inflammation response index were included to build the clinical model. The combined model, incorporating three clinical factors and AP+VP-Radscore, achieved the highest C-indices of 0.764 and 0.746 in the training and validation cohorts, respectively. In terms of preoperative prognosis prediction for PDAC, the calibration curve and DCA showed that the combined model had a good consistency and greatest net benefit.

Conclusion

A combined model of clinical features and AP+VP-Radscore screened using multiple ML algorithms has an excellent ability to predict the prognosis of PDAC and may provide a noninvasive and effective method for clinical decision-making.

Advances in CAR-T therapy for central nervous system tumors

The application of chimeric antigen receptor T-cell therapy in central nervous system tumors has significantly advanced; however, challenges pertaining to the blood-brain barrier, immunosuppressive microenvironment, and antigenic heterogeneity continue to be encountered, unlike its success in hematological malignancies such as acute lymphoblastic leukemia and diffuse large B-cell lymphomas. This review examined the research progress of chimeric antigen receptor T-cell therapy in gliomas, medulloblastomas, and lymphohematopoietic tumors of the central nervous system, focusing on chimeric antigen receptor T-cells targeting antigens such as EGFRvIII, HER2, B7H3, GD2, and CD19 in preclinical and clinical studies. It synthesized current research findings to offer valuable insights for future chimeric antigen receptor T-cell therapeutic strategies for central nervous system tumors and advance the development and application of this therapeutic modality in this domain.

Probiotic neoantigen delivery vectors for precision cancer immunotherapy

Microbial systems have been synthetically engineered to deploy therapeutic payloads in vivo1,2. With emerging evidence that bacteria naturally home in on tumours3,4 and modulate antitumour immunity5,6, one promising application is the development of bacterial vectors as precision cancer vaccines2,7. Here we engineered probiotic Escherichia coli Nissle 1917 as an antitumour vaccination platform optimized for enhanced production and cytosolic delivery of neoepitope-containing peptide arrays, with increased susceptibility to blood clearance and phagocytosis. These features enhance both safety and immunogenicity, achieving a system that drives potent and specific T cell-mediated anticancer immunity that effectively controls or eliminates tumour growth and extends survival in advanced murine primary and metastatic solid tumours. We demonstrate that the elicited antitumour immune response involves recruitment and activation of dendritic cells, extensive priming and activation of neoantigen-specific CD4+ and CD8+ T cells, broader activation of both T and natural killer cells, and a reduction of tumour-infiltrating immunosuppressive myeloid and regulatory T and B cell populations. Taken together, this work leverages the advantages of living medicines to deliver arrays of tumour-specific neoantigen-derived epitopes within the optimal context to induce specific, effective and durable systemic antitumour immunity.