The evolving tumor microenvironment: From cancer initiation to metastatic outgrowth

An integral membrane constitutively active heparanase enhances the tumor infiltration capability of NK cells

Eradication of cancer cells by the immune system requires extravasation, infiltration and progression of immune cells through the tumor extracellular matrix (ECM). These are also critical determinants for successful adoptive cell immunotherapy of solid tumors. Together with structural proteins, such as collagens and fibronectin, heparan sulfate (HS) proteoglycans are major components of the ECM. Heparanase 1 (HPSE) is the only enzyme known to have endoglycosidase activity that degrades HS. HPSE is expressed at high levels in almost all hematopoietic cells, which suggests that it plays a relevant role in immune cell migration through solid tissues. Besides, tumor cells express also HPSE as a way to facilitate tumor cell resettlement and metastasis. Therefore, an increase in HPSE in the tumor ECM would be detrimental. Here, we analyzed the effects of constitutive expression of an active, membrane-bound HPSE on the ability of human natural killer (NK) cells to infiltrate tumors and eliminate tumor cells. We demonstrate that NK cells expressing a chimeric active form of HPSE on the cell surface as an integral membrane protein, display significantly enhanced infiltration capability into spheroids of various cancer cell lines, as well as into xenograft tumors in immunodeficient mice. As a result, tumor growth was significantly suppressed without causing noticeable side effects. Altogether, our results suggest that a constitutively expressed active HSPE on the surface of immune effector cells enhances their capability to access and eliminate tumor cells. This strategy opens new possibilities for improving adoptive immune treatments using NK cells.

Glutamate promotes CCL2 expression to recruit tumor-associated macrophages by restraining EZH2-mediated histone methylation in hepatocellular carcinoma

Glutamate is well-known as metabolite for maintaining the energy and redox homeostasis in cancer, moreover it is also the primary excitatory neurotransmitter in the central nervous system. However, whether glutamatergic signaling can regulate hepatocellular carcinoma (HCC) progression and the specific regulatory mechanisms are unknown. In the present study, we found that glutamate and its receptor NMDAR2B were significantly elevated in HCC patients, which predicts poor prognosis. Glutamate could upregulate CCL2 expression on hepatoma cells and further enhance the capability of tumor cells to recruit tumor-associated macrophages (TAMs). Mechanistically, glutamate could facilitate CCL2 expression through NMDAR pathway by decreasing the expression of EZH2, which regulates the H3K27me3 levels on the CCL2 promoter, rather than affecting DNA methylation. Moreover, inhibiting glutamate pathway with MK801 could significantly delay tumor growth, with reduced TAMs in implanted Hepa1-6 mouse HCC models. Our work suggested that glutamate could induce CCL2 expression to promote TAM infiltration by negatively regulating EZH2 levels in hepatoma cells, which might serve as a potential prognostic marker and a therapeutic target for HCC patients.

Patient-derived tumor explant models of tumor immune microenvironment reveal distinct and reproducible immunotherapy responses

Tumor-resident immune cells play a crucial role in eliciting anti-tumor immunity and immunomodulatory drug responses, yet these functions have been difficult to study without tractable models of the tumor immune microenvironment (TIME). Patient-derived ex vivo models contain authentic resident immune cells and therefore, could provide new mechanistic insights into how the TIME responds to tumor or immune cell-directed therapies. Here, we assessed the reproducibility and robustness of immunomodulatory drug responses across two different ex vivo models of breast cancer TIME and one of renal cell carcinoma. These independently developed TIME models were treated with a panel of clinically relevant immunomodulators, revealing remarkably similar changes in gene expression and cytokine profiles among the three models in response to T cell activation and STING-agonism, while still preserving individual patient-specific response patterns. Moreover, we found two common core signatures of adaptive or innate immune responses present across all three models and both types of cancer, potentially serving as benchmarks for drug-induced immune activation in ex vivo models of the TIME. The robust reproducibility of immunomodulatory drug responses observed across diverse ex vivo models of the TIME underscores the significance of human patient-derived models in elucidating the complexities of anti-tumor immunity and therapeutic interventions.

CAFs-released exosomal CREB1 promotes cell progression and immune evasion in thyroid cancer via the positive regulation of CCL20

BACKGROUND

Exosomes derived from cancer-associated fibroblasts (CAFs) can affect tumor microenvironment (TME) of thyroid cancer (TC). The cAMP response element binding protein 1 (CREB1) acts as a transcription factor to participate in cancer development. Currently, we aimed to explore the molecular mechanism of exosome-associated CREB1 and C-C motif chemokine ligand 20 (CCL20) in TC.

METHODS

The mRNA and protein levels were examined via RT-qPCR and western blot. Gene interaction was analyzed using ChIP and dual-luciferase reporter assays. Cell migration, invasion and proliferation were assessed by wound healing, transwell and EdU assays. Exosomes were characterized by morphology observation and western blot. The proliferation and apoptosis of CD8+ T cells were detected by immunofluorescence and flow cytometry. In vivo assays were performed by establishing xenograft models.

RESULTS

CREB1 was highly expressed in TC. CREB1 positively interacted with CCL20 in TC. CREB1 facilitated TC cell migration, invasion and proliferation via targeting CCL20. CCL20 expression was reduced by transferring CAFs-secreted exosomes sheltering CREB1 downregulation. Exosomal CREB1 knockdown receded cell progression and enhanced CD8+ T function by mediating CCL20. CAFs-associated exosomal CREB1 downregulation inhibited tumorigenesis through affecting CCL20.

CONCLUSION

CAFs-derived exosomes accelerated the malignant behaviors and immune evasion in TC by carrying CREB1 to up-regulate CCL20.

Discovery of hydrazide-based PI3K/HDAC dual inhibitors with enhanced pro-apoptotic activity in lymphoma cells

PI3K and HDAC are concurrently upregulated in a variety of cancers, and simultaneous inhibition of PI3K and HDAC may synergistically inhibit tumor proliferation and induce apoptosis, providing a rationale for the study of dual-target PI3K/HDAC inhibitors. In this study, we rationally designed and synthesized a series of novel PI3K/HDAC dual-target inhibitors by combining the morpholino-triazine pharmacophore of PI3K inhibitor ZSTK474 with the hydrazide moiety of HDAC1-3 selective inhibitor 11h. Representative compound 31f possessed both PI3K (IC50 = 2.5-80.5 nM for PI3Kα, β, γ, and δ) and HDAC1-3 inhibitory activities (IC50 = 1.9-75.5 nM for HDAC1-3). 31f showed potent antiproliferative activity against a variety of tumor cell lines. Meanwhile, we designed and synthesized tool molecule 39a, a HDAC inhibitor structurally similar to 31f. In the mantle cell lymphoma Jeko-1 cell line, 31f showed significantly greater efficacy than the single inhibitors in inducing apoptosis. In conclusion, this study provided insights into the development of novel hydrazide-based dual HDAC/PI3K inhibitors.

Glioblastoma cells secrete ICAM1 via FASN signaling to promote glioma-associated macrophage infiltration

Glioma-associated macrophages (GAMs) constitute the most abundant subset of immune cells in the glioblastoma (GBM) microenvironment, but the underlying mechanism of intense infiltration needs to be elucidated. In this study, we found that GBM cells secrete ICAM1 via FASN signaling to promote GAM infiltration. FASN expression is correlated with GAM density in GBM patients. In vitro experiments revealed that FASN regulates the type-I interferon pathway, particularly STAT1 expression. Moreover, disrupting FASN-STAT1 signaling through the overexpression or inhibition of FASN or STAT1 in GBM cells strongly influences microglial recruitment. Additionally, ICAM1 acts as a direct transcriptional candidate of FASN-STAT1 and a paracrine soluble factor, recruiting microglia to GBM tumors. This study revealed crosstalk between GBM cells and GAMs through FASN-STAT1-ICAM1 signaling to promote microglial infiltration, suggesting potential strategies for treating GBM patients.

A microfluidic co-culture platform for lung cancer cells electrotaxis study under the existence of stromal cells

Tumor metastasis is an important reason for the poor prognosis and high mortality in cancer patients. As major component of stromal cells in tumor microenvironment, cancer-associated fibroblasts (CAFs) secreted various factors to promote tumor metastasis. Studies have indicated that endogenous direct current electric field (dcEF) around tumor tissue induced directional migration of cancer cells. However, the regulatory effect of CAFs on cancer migration under dcEF stimulation is still unknown. In this study, a two-layers polydimethylsiloxane (PDMS)-based microfluidic chip was fabricated. The introduction of concave structures achieved the non-contacted co-culture of different cell types, and parallel channels in the chip provided stable and homogeneous dcEF. Cells electrotactic response was evaluated under co-culture circumstance. The results showed that CAFs exhibited directional migration towards anode under dcEF stimulation, while A549 cells had a trend of directional migration towards cathode. The co-existence of CAFs and dcEF significantly enhanced the motility and cathodal migration of A549 cells, suggesting synergistic influences of chemotaxis from CAFs and electrotaxis from dcEF stimulation. Moreover, we demonstrated that lung normal fibroblasts acquired CAFs properties after stimulated by dcEF, characterizing by increasing gene expression of α-SMA and IL-6. Overall, Our device and study provide new insight for tumor electrotaxis in complex microenvironment.

Nanotherapeutic strategies exploiting biological traits of cancer stem cells

Cancer stem cells (CSCs) represent a distinct subpopulation of cancer cells that orchestrate cancer initiation, progression, metastasis, and therapeutic resistance. Despite advances in conventional therapies, the persistence of CSCs remains a major obstacle to achieving cancer eradication. Nanomedicine-based approaches have emerged for precise CSC targeting and elimination, offering unique advantages in overcoming the limitations of traditional treatments. This review systematically analyzes recent developments in nanomedicine for CSC-targeted therapy, emphasizing innovative nanomaterial designs addressing CSC-specific challenges. We first provide a detailed examination of CSC biology, focusing on their surface markers, signaling networks, microenvironmental interactions, and metabolic signatures. On this basis, we critically evaluate cutting-edge nanomaterial engineering designed to exploit these CSC traits, including stimuli-responsive nanodrugs, nanocarriers for drug delivery, and multifunctional nanoplatforms capable of generating localized hyperthermia or reactive oxygen species. These sophisticated nanotherapeutic approaches enhance selectivity and efficacy in CSC elimination, potentially circumventing drug resistance and cancer recurrence. Finally, we present an in-depth analysis of current challenges in translating nanomedicine-based CSC-targeted therapies from bench to bedside, offering critical insights into future research directions and clinical implementation. This review aims to provide a comprehensive framework for understanding the intersection of nanomedicine and CSC biology, contributing to more effective cancer treatment modalities.

The role of the tumor microenvironment and inflammatory pathways in driving drug resistance in gastric cancer: A systematic review and meta-analysis

Tumor microenvironment (TME) plays a pivotal role in progression and low responsiveness to chemotherapy of gastric cancer (GC). The cascade of events that culminate with a sustained and chronic activation of inflammatory pathways underlies gastric tumorigenesis. Infiltrating immune cells enrolling in crosstalk with cancer cells that regulate inflammatory and immune status, generating an immunosuppressive TME that influences the response to therapy. Here we discuss the role of TME and the activation of inflammatory pathways to comprehend strategies to improve drug response. Furthermore, we provides systematic insight the role of TME cytotypes and related signatures reinforcing the critical roles of TAMs and Tregs, in promoting GC chemoresistance and tumor progression.

Unveiling rifampin's impact on OSCC lysate-pulsed DCs: From inflammatory to anti-inflammatory landscape

Dendritic cells (DCs) play a critical role in immune responses, being essential antigen-presenting cells (APCs) for T cell activation. In the context of cancer immunotherapy, DCs are pivotal for eliciting robust CD4+ and CD8+ T cell responses against tumor antigens. However, in oral squamous cell carcinoma (OSCC), DCs encounter challenges due to the immunosuppressive tumor microenvironment (TME). Factors like vascular endothelial growth factor (VEGF) and interleukin (IL)-6 in OSCC hinder DC function and maturation. To address this, current research has focused on enhancing DC immunogenicity to boost anti-tumor immunity. Rifampin, known for its antibacterial properties, presents immunomodulatory effects that could be beneficial in augmenting DC function in cancer therapy. This study investigates the impact of rifampin treatment on OSCC lysate-loaded-DCs. Results show that rifampin enhances the expression of key inflammatory factors while reducing anti-inflammatory mediators in DCs. Moreover, rifampin treatment enhances the immune-stimulatory capabilities of OSCC lysate-loaded-DCs, potentially improving their effectiveness in cancer immunotherapy.

Unveiling the role of extracellular matrix elements and regulators in shaping ovarian cancer growth and metastasis

Epithelial ovarian cancer (EOC) progression is determined by numerous intracellular interactions and the interplay between malignant cells, normal cells, and the tumor acellular microenvironment, formed largely by the extracellular matrix (ECM). The structure and biochemical functioning of various ECM components, along with the activity of agents that regulate ECM remodeling, impact the disease's expansion (adhesion, proliferation, invasion), spread, and response to therapy. It is important to note that the involvement of ECM components and their regulators in the progression of EOC is bidirectional and distinctly depends on a particular tissue context. In certain situations, certain components of the ECM enhance the activity of cancer cells, but in other scenarios, they suppress it. In this review, we summarize the newest knowledge regarding diverse aspects of ECM engagement in EOC pathophysiology and chemotherapy. Moreover, we delineate conditions that exacerbate the pro-cancerous properties of ECM, including diabetes-associated glycation, aging, and cellular senescence. We also explore methods to therapeutically alter the properties of the ECM, which could be beneficial in ovarian cancer prevention and treatment.

Chiral nanoassembly remodels tumor microenvironment through non-oxygen-dependent depletion lactate for effective photodynamic immunotherapy

Targeting lactate metabolism in tumor microenvironment (TME) has emerged as a promising strategy for enhancing immunotherapy. However, the commonly used strategy of lactate oxidation by lactate oxidase consumes oxygen, exacerbating tumor hypoxia and hindering immunotherapy. Here, we present a novel tumor-targeting, near infrared light-activated and TME-responsive chiral nanoassembly (Zn-UCMB) for enhancing photodynamic triggered immunogenic cell death (ICD) through a nonoxygen-dependent depletion of lactate. In the moderately acidic TME, the chiral Zn complex liberated from the Zn-UCMB selectively coordinates with l-lactate, leading to the depletion of lactate. Additionally, the Zn-UCMB facilitates the decomposition of H2O2 into O2, which significantly enhances the efficacy of photodynamic therapy (PDT) and triggers a robust ICD effect. Moreover, the nonoxygen-dependent depletion of lactate can reprogram the TME by reducing the expression of HIF-1α, decreasing VEGF expression, and mitigating immunosuppressive conditions. This prompts the phenotypic transformation of tumor-associated macrophages from M2 to M1. Consequently, Zn-UCMB not only enhances the efficacy of PDT but also elicits a potent ICD during 980 nm laser irradiation, thereby effectively suppressing tumor growth and metastasis. The findings offer a novel approach to overcome the limitations of existing lactate metabolism-targeting strategies and provide a promising therapeutic option for enhancing the efficacy of immunotherapy.

Imaging probes for the detection of brain microenvironment

The brain microenvironment (BME) is a highly dynamic system that plays a critical role in neural excitation, signal transmission, development, aging, and neurological disorders. BME consists of three key components: neural cells, extracellular spaces, and physical fields, which provide structures and physicochemical properties to synergistically and antagonistically regulate cell behaviors and functions such as nutrient transport, waste metabolism and intercellular communication. Consequently, monitoring the BME is vital to acquire a better understanding of the maintenance of neural homeostasis and the mechanisms underlying neurological diseases. In recent years, researchers have developed a range of imaging probes designed to detect changes in the microenvironment, enabling precise measurements of structural and biophysical parameters in the brain. This advancement aids in the development of improved diagnostic and therapeutic strategies for brain disorders and in the exploration of cutting-edge mechanisms in neuroscience. This review summarizes and highlights recent advances in the probes for sensing and imaging BME. Also, we discuss the design principles, types, applications, challenges, and future directions of probes.

Harnessing prazosin for tumors: Liposome hybrid nanovesicles activate tumor immunotherapy via autophagy inhibition

Prazosin (Prz), an antagonist of alpha-1 adrenergic receptors, is conventionally employed in the treatment of hypertension. Our study pioneers the exploration of Prz in oncology, examining its impact on cellular autophagy and its potential to trigger antitumor immune responses. We have developed a novel Prz-loaded liposome hybrid nanovesicle (Prz@LINV) system, integrating tumor-derived nanovesicles (TNV) with liposomes (LIP) to facilitate targeted Prz delivery to tumor sites. This formulation enhances Prz bioavailability and markedly inhibits tumor cell autophagy, leading to immunogenic cell death (ICD) and the activation of antitumor immune responses. Furthermore, Prz@LINV modulates dendritic cells (DCs), augmenting their antigen cross-presentation capacity and thereby potentiating antitumor immunity. These effects were validated in a colorectal cancer mouse model, demonstrating the good biocompatibility of Prz@LINV and its significant inhibition in tumor growth, along with the enhancement of antitumor immune responses. Our findings elucidate a novel mechanism by which Prz inhibits autophagy and enhances the antitumor immune response, providing a foundation for the development of innovative immunotherapeutic strategies. The efficacy of Prz@LINV suggests that Prz may emerge as a pivotal component in future immunotherapeutic regimens, offering patients more potent therapeutic options.

Loss of SPHK1 fuels inflammation to drive KRAS-mutated lung adenocarcinoma

Inflammation is a widely recognized key contributor to KRAS-driven lung adenocarcinoma (LUAD). Tumor-associated macrophages (TAM) are an integral part of the tumor microenvironment and create a supportive niche that sustains inflammation-driven tumorigenesis. In the present study, we unravel a dual role of sphingosine kinase 1 (SPHK1) in KRAS-driven LUAD. While SPHK1 promotes tumorigenesis in in vitro experimental models, it paradoxically suppresses tumorigenesis in in vivo models of KRAS-mutated LUAD. Mechanistically, tumor-intrinsic loss of SPHK1 leads to disrupted lipid homeostasis, increased inflammation and infiltration by TAM, ultimately driving tumor progression. Thus, our study suggests that clinically targeting the SPHK1/S1P axis could potentially result in increased tumor progression, possibly by rewiring the tumor microenvironment toward a more inflammatory and pro-tumorigenic state.

Tumors and their microenvironments: Learning from pediatric brain pathologies

Early clues to tumors and their microenvironments come from embryonic development. Here we review the literature and consider whether the embryonic brain and its pathologies can serve as a better model. Among embryonic organs, the brain is the most heterogenous and complex, with multiple lineages leading to wide spectrum of cell states and types. Its dysregulation promotes neurodevelopmental brain pathologies and pediatric tumors. Embryonic brain pathologies point to the crucial importance of spatial heterogeneity over time, akin to the tumor microenvironment. Tumors dedifferentiate through genetic mutations and epigenetic modulations; embryonic brains differentiate through epigenetic modulations. Our innovative review proposes learning developmental brain pathologies to target tumor evolution-and vice versa. We describe ways through which tumor pharmacology can learn from embryonic brains and their pathologies, and how learning tumor, and its microenvironment, can benefit targeting neurodevelopmental pathologies. Examples include pediatric low-grade versus high-grade brain tumors as in rhabdomyosarcomas and gliomas.

Smart materials in pharmacological drug development: Neutrophils and its constituents for drug delivery and consequent antitumor effects

Neutrophil-based drug delivery systems for targeted therapy of cancer have been studied widely in the recent past. Chemotactic cytokines including colony-stimulating factors (CSFs) recruit various immune cells including the neutrophils to the tumor microenvironment (TME) leading to enhanced metastasis. These cytokines can be targeted effectively by immunotherapeutic agents such as checkpoint inhibitors and mAbs that can lead to systemic toxicity. To minimize the systemic adverse effects, camouflaged nanoparticles can be used significantly as alternative therapeutic agents. The neutrophil-interacting NPs and neutrophil membrane coated NPs have been exploited recently for their antitumor properties in vitro and pose limited systemic adverse effects in vivo. Neutrophil-derived exosomes derived from immune cells can efficiently escape immune-surveillance and pass through the blood-brain barrier. They possess several intrinsic properties in drug delivery as they are nano-sized, extremely biocompatible, non-immunogenic, biodegradable, stable and can carry targeting agents with limited toxicity and display antitumor properties. Also, neutrophil-based nanotherapy is dependent on factors such as neutrophil kinetics and the physicochemical properties of NPs such as size, shape, and surface chemistry. Therefore, neutrophil-based drug delivery for cancer therapy via the use of polymer nanoparticles is widely studied as their clinical appliance in nanomedicine is still at its infancy.

High metastatic tumor-derived CXCL16 mediates liver colonization metastasis by inducing Kupffer cell polarization via the PI3K/AKT/FOXO3a pathway

Liver metastases represent a late-stage manifestation of numerous cancers, often associated with poor patient prognosis. Kupffer cells (KCs), resident liver macrophages, play a critical role in liver metastasis (LM). However, the mechanisms by which the polarization of KCs facilitate colorectal cancer (CRC) liver metastases remain elusive. Here, we established a CRC liver metastasis mouse model and employed a co-culture system, found that KCs were recruited and polarized to M2 phenotype. We isolated and purified highly metastatic cell lines to reveal potential changes in CRC cells during metastasis. Through bulk RNA sequencing, we identified and validated CXCL16 as a positive mediator in liver-metastatic CT26-LM cells that induced an M2-like KC phenotype. Knock down of CXCL16 reduced the M2 polarization of KCs and inhibited the formation of liver metastasis lesions. Next, this polarization process was shown to be achieved through the PI3K/AKT/FOXO3a pathway. Further investigation revealed FOXO3a transcriptionally activates CD206(MRC1) in this process. Pharmacological inhibition of the CXCL16-PI3K-FOXO3a axis to disrupt the polarization of KCs attenuated CRC liver metastasis in vivo. Our findings collectively indicate that targeting the CXCL16/PI3K/AKT/FOXO3a pathway in KCs may represent a promising therapeutic strategy for preventing CRC liver metastasis.

Extracellular vesicles as the common denominator among the 7 Rs of radiobiology: From the cellular level to clinical practice

Extracellular vesicles (EVs) are lipid-bound particles released by tumor cells and widely explored in cancer development, progression, and treatment response, being considered as valuable components to be explored as biomarkers or cellular targets to modulate the effect of therapies. The mechanisms underlying the production and profile of EVs during radiotherapy (RT) require addressing radiobiological aspects to determine cellular responses to specific radiation doses and fractionation. In this review, we explore the role of EVs in the 7 Rs of radiobiology, known as the molecular basis of a biological tissue response to radiation, supporting EVs as a shared player in all the seven processes. We also highlight the relevance of EVs in the context of liquid biopsy and resistance to immunotherapy, aiming to establish the connection and utility of EVs as tools in contemporary and precision radiotherapy.

Metabolic reprogramming of tumor microenviroment by engineered bacteria

The tumor microenvironment (TME) is a complex ecosystem that plays a crucial role in tumor progression and response to therapy. The metabolic characteristics of the TME are fundamental to its function, influencing not only cancer cell proliferation and survival but also the behavior of immune cells within the tumor. Metabolic reprogramming-where cancer cells adapt their metabolic pathways to support rapid growth and immune evasion-has emerged as a key factor in cancer immunotherapy. Recently, the potential of engineered bacteria in cancer immunotherapy has gained increasing recognition, offering a novel strategy to modulate TME metabolism and enhance antitumor immunity. This review summarizes the metabolic properties and adaptations of tumor and immune cells within the TME and summarizes the strategies by which engineered bacteria regulate tumor metabolism. We discuss how engineered bacteria can overcome the immunosuppressive TME by reprogramming its metabolism to improve antitumor therapy. Furthermore, we examine the advantages, potential challenges, and future clinical translation of engineered bacteria in reshaping TME metabolism.

Investigating the molecular mechanisms and clinical potential of APO+ endothelial cells associated with PANoptosis in the tumor microenvironment of hepatocellular carcinoma using single-cell sequencing data

INTRODUCTION

PANoptosis is a newly identified form of programmed cell death that integrates elements of pyroptosis, apoptosis, and necroptosis. It plays a pivotal role in shaping the tumor immune microenvironment. Despite its significance, the specific functions and mechanisms of PANoptosis within the tumor microenvironment (TME) of hepatocellular carcinoma (HCC) remain unclear. This study aims to investigate these mechanisms using single-cell RNA sequencing data.

METHODS

Single-cell RNA sequencing data from HCC patients were obtained from the GEO database. The AUCell algorithm was used to quantify PANoptosis activity across various cell types in the TME. Cell populations with high PANoptosis scores were further analyzed using CytoTRACE and scMetabolism to assess their differentiation states and metabolic profiles. Associations between these high-score cell subsets and patient prognosis, tumor stage, and response to immunotherapy were examined. Cell-cell communication analysis was performed to explore how PANoptosis-related APO+ endothelial cells (ECs) may influence HCC progression. Immunofluorescence staining was used to assess the spatial distribution of APO+ ECs in tumor and adjacent tissues. Finally, a CCK8 assay was conducted to evaluate the effect of APOH+ HUVECs on HCC cell proliferation.

RESULTS

A total of 16 HCC patient samples with single-cell RNA sequencing data were included in the study. By calculating the PANoptosis scores of different cell types, we found that ECs, macrophages, hepatocytes, and fibroblasts exhibited higher PANoptosis scores. The PANoptosis scores, differentiation trajectories, intercellular communication, and metabolic characteristics of these four cell subpopulations with high PANoptosis scores were visualized. Among all subpopulations, APO+ ECs demonstrated the most significant clinical relevance, showing a positive correlation with better clinical staging, prognosis, and response to immunotherapy in HCC patients. Cellular communication analysis further revealed that APO+ ECs might regulate the expression of HLA molecules, thereby influencing T cell proliferation and differentiation, potentially contributing to improved prognosis in HCC patients. Immunofluorescence staining results indicated that APO+ ECs were primarily located in the adjacent tissues of HCC patients, with lower expression in tumor tissues. The results of cellular experiments showed that APOH+ HUVECs significantly inhibited the proliferation of HCC cells.

CONCLUSIONS

This study systematically mapped the cellular landscape of the TME in HCC patients and explored the differences in differentiation trajectories, metabolic pathways, and other aspects of subpopulations with high PANoptosis scores. Additionally, the study elucidated the potential molecular mechanisms through which APO+ ECs inhibit HCC cell proliferation and improve prognosis and immunotherapeutic efficacy in HCC patients. This research provides new insights for clinical prognosis evaluation and immunotherapy strategies in HCC.

Role of liposomes in chemoimmunotherapy of breast cancer

In the dynamic arena of cancer therapeutics, chemoimmunotherapy has shown tremendous promise, especially for aggressive forms of breast cancer like triple-negative breast cancer (TNBC). This review delves into the significant role of liposomes in enhancing the effectiveness of chemoimmunotherapy by leveraging breast cancer-specific mechanisms such as the induction of immunogenic cell death (ICD), reprogramming the tumour microenvironment (TME), and enabling sequential drug release. We examine innovative dual-targeting liposomes that capitalise on tumour heterogeneity, as well as pH-sensitive formulations that offer improved control over drug delivery. Unlike prior analyses, this review directly links advancements in preclinical research-such as PAMAM dendrimer-based nanoplatforms and RGD-decorated liposomes-to clinical trial results, highlighting their potential to revolutionise TNBC treatment strategies. Additionally, we address ongoing challenges related to scalability, toxicity, and regulatory compliance, and propose future directions for personalised, immune-focused nanomedicine. This work not only synthesises the latest research but also offers a framework for translating liposomal chemoimmunotherapy from laboratory research to clinical practice.

Repaglinide platinum(IV) conjugates: Enhancing p53 signaling for antitumor and antimetastatic efficacy

The tumor suppressor p53 plays multiple roles at the crossroads of suppressing tumor development and metastasis. Here, a series of Repaglinide platinum(IV) conjugates promoting the p53 pathway were designed and prepared, which displayed potent antiproliferative and antimetastatic activities both in vitro and in vivo. Mechanistically, the expression of p53 was upregulated by the synergistic functions of the platinum core through causing severe DNA damage, and the RPG ligand via stimulating the lumican/p53/p21 pathway. The mitochondria-mediated apoptosis was initiated, involving the Bcl-2/Bax/caspase pathway. Pro-death autophagy was initiated with the upregulation of LC3II and down regulation of p62. Additionally, angiogenesis was suppressed by reversing tumor inflammation through the inhibition of key enzymes COX-2, MMP9, and VEGFA. Furthermore, antitumor immunity was enhanced by blocking the immune checkpoint PD-L1, which led to an increased presence of CD3+ and CD8+ T-cells within the tumor microenvironment.

DEPP1: A prognostic biomarker linked to stroma‑rich and immunosuppressive microenvironment, promoting oxaliplatin resistance in gastric cancer

Decidual protein induced by progesterone (DEPP1) was identified to exert heterogeneous functions in several cancers, whereas its role in gastric cancer (GC) remains elusive. In the present study, differential expression analysis was conducted using three Gene Expression Omnibus datasets (GSE54129, GSE26942 and GSE3438). Validation of DEPP1 expression was performed using reverse transcription‑quantitative PCR, western blotting and immunofluorescence. Kaplan‑Meier survival and Cox regression analyses were employed to assess the association between DEPP1 expression and the prognosis of patients with GC. Immune infiltration analysis was conducted to explore the correlation between DEPP1 and the tumor microenvironment. The potential of DEPP1 to promote oxaliplatin resistance was assessed using flow cytometry, western blotting, and subcutaneous mouse models. DEPP1 was found to be significantly upregulated in the aforementioned cohorts, which was consistent with the clinical specimens of the present study, and it emerged as an independent risk factor for poor overall survival in patients with GC. A prognostic nomogram was developed to improve prognosis prediction. High DEPP1 expression correlated with increased infiltration of cancer‑associated fibroblasts, endothelial cells, and M2 macrophages, contributing to the development of a stroma‑rich and immunosuppressive microenvironment in GC. Furthermore, high DEPP1 expression was associated with reduced sensitivity to chemotherapy drugs in patients with GC. In vitro and in vivo experiments highlighted DEPP1's crucial role in promoting oxaliplatin resistance in GC. In conclusion, DEPP1 is identified as a promising prognostic biomarker linked to a stroma‑rich and immunosuppressive microenvironment, and it is critical in driving oxaliplatin resistance in GC. These findings may inform personalized therapeutic strategies for patients with GC.

Neuro-astrocytic network in breast cancer brain metastases: Adaptive mechanisms and novel therapeutic targets

Breast cancer brain metastases (BrM) are a common and fatal complication in advanced breast cancer patients, with the intricate brain microenvironment significantly limiting the efficacy of current therapeutic strategies. Recently, the neuro-astrocytic network, as a core component of the brain metastasis microenvironment, has garnered extensive attention for its pivotal role in supporting tumor adaptive growth. This review systematically outlines the adaptive mechanisms of the neuro-astrocytic network in BrM, including bidirectional interactions between tumor cells, neurons, and astrocytes, and their profound effects on synapse-like signaling, metabolic pathways, and regulatory networks. Furthermore, we integrate recent advancements in exploring therapeutic targets and discuss potential intervention strategies against tumor-microenvironment interactions and associated challenges. Future research focusing on the multi-target collaborative mechanisms within this network and its clinical translational potential may provide new avenues for precise treatment of BrM.

Interactions between cancer cells and tumor-associated macrophages in tumor microenvironment

Tumor microenvironment (TME) refers to the local environment in which various cancer cells grow, encompassing tumor cells, adjacent non-tumor cells, and associated non-cellular elements, all of which collectively promote cancer occurrence and progression. As a principal immune component in the TME, tumor-associated macrophages (TAMs) exert a considerable influence on cancer behaviors via their interactions with cancer cells. The interactive loops between cancer cells and TAMs, including secretory factors derived from both cancer cells and TAMs, are crucial for the proliferation, stemness, drug resistance, invasion, migration, metastasis, and immune escape of various cancers. Cancer cells release paracrine proteins (HMGB1, AREG etc.), cytokines (IL-6, CCL2 etc.), RNAs (miR-21-5p, circPLEKHM1, LINC01812 etc.), and metabolites (lactic acid, succinate etc.) to regulate the polarization phenotype, mediator secretion and function of TAMs. In turn, mediators (TGF-β, IL-10, IL-6 etc.) from TAMs promote cancer progression. This review summarizes recent advancements in the interactive loops between cancer cells and TAMs in TME. Inhibiting the recruitment and M2 polarization of TAMs, reprogramming TAMs from M2 to M1 phenotype, blocking TAMs-mediated immunosuppression and immune escape, and combining with existing immunotherapy can target TAMs to overcome immunotherapy resistance in various cancers. The new breakthroughs lie in identifying effective targets for drug development, improving the drug delivery system to enhance the drug delivery efficiency, and adopting combined therapy. Interventions targeting secretory factors, cell surface receptors, intracellular signaling pathways, and metabolic modulation in the interactive loops between cancer cells and TAMs are expected to suppress cancer progression and improve therapeutic effects.

Deciphering the "Rosetta Stone" of ovarian cancer stem cells: Opportunities and challenges

Ovarian cancer stem cells (OCSCs) play a pivotal role in the initiation, maintenance, and progression of ovarian cancer, functioning through complex molecular mechanisms that are closely linked to metastasis and drug resistance. The complexity of these underlying mechanisms contributes to cancer hallmarks such as the high plasticity of OCSCs, leading to chemotherapy resistance; activation of invasion and metastasis, epigenetic reprogramming, and cell death resistance; and deregulation of cellular metabolism. OCSCs are characterized by the expression of markers including ALDH, CD133, CD44, and CD24. They preserve their stemness through intricate molecular mechanisms that involve interactions with the tumor microenvironment and various signaling pathways. To investigate these molecular mechanisms, both in vitro and in vivo models of OCSC have been established. The results of these studies can be applied in clinical practice, facilitating the development of various new therapies. This review aims to provide a deeper understanding of the mechanisms through which OCSCs function, highlighting significant opportunities for future research aimed at improving ovarian cancer treatment.

Lactoferrin in cancer: Focus on mechanisms and translational medicine

Lactoferrin is an iron-binding glycoprotein that provides natural protective effects to the human body. Its biological properties, including antibacterial, antiviral, anti-inflammatory, immune-regulatory, and iron metabolism-regulating functions, have been extensively studied. With further research, lactoferrin's impact on tumorigenesis and tumor microenvironment has become increasingly evident, as it inhibits tumor proliferation, invasion, and metastasis through multiple pathways. This article summarizes the molecular mechanisms underlying lactoferrin's anticancer effects, explores its association with the malignant progression of various cancers, and highlights its clinical translational potential as a potential cancer biomarker and drug delivery carrier to enhance anticancer therapy efficiency. Due to the high safety profile of lactoferrin, its widespread application in the field of cancer treatment is highly anticipated.

Gastric cancer cells shuttle lactate to induce inflammatory CAF-like phenotype and function in bone marrow-derived mesenchymal stem cells

Metabolic reprogramming, exemplified by the "Warburg effect," is a hallmark of human cancers, leading to lactate buildup in tumors. Bone marrow-derived mesenchymal stem cells (BM-MSCs), key contributors to cancer-associated fibroblasts (CAFs), integrate into gastric cancer stroma through interactions with cancer cells. However, the role of lactate in activating BM-MSCs in this context remains unclear. Herein, exogenous lactate induced a pro-tumorigenic phenotype in BM-MSCs, which was blocked by AZD3965. Gastric cancer cells released more lactate under hypoxia than normoxia. While normoxic gastric cancer cells could educate BM-MSCs, hypoxic cells were more effective. However, the effects of the supernatant from gastric cancer cells in both conditions were significantly reduced by AZD3965. Similarly, prevention of lactate production by oxamic acid sodium significantly reduced the effects observed. Lactate-activated BM-MSCs showed NF-κB signaling activation, increased IL-8 secretion, and no change in TGF-β signaling. These activated BM-MSCs promoted gastric cancer cell migration and invasion through IL-8 secretion and enhanced resistance to CD8 + T cell cytotoxicity by upregulating PD-L1. Collectively, gastric cancer cells induce an iCAF-like phenotype and function in BM-MSCs through a lactate shuttle mechanism, emphasizing the role of metabolic reprogramming in cellular communication that fosters a supportive tumor microenvironment. Targeting lactate-related pathways may provide new therapeutic strategies to hinder BM-MSCs' supportive roles in gastric cancer.

Research progress on the regulatory role of lactate and lactylation in tumor microenvironment

The tumor microenvironment (TME) arises from the dynamic interactions between tumor cells and the surrounding medium, including a variety of cell types and extracellular components, which have an important impact on the genesis and development of tumors. A key player in TME is lactate, a metabolic byproduct of glycolysis, which serves as a significant energy source. Lactate has direct implications on the survival and differentiation of immune cells, the metabolic reprogramming and progression of tumor cells. Moreover, lactylation, a unique post-translational modification, exerts a regulatory effect on TME by affecting gene transcription via adding lactate groups to both histone and non-histone proteins. This review systematically and comprehensively synthesizes emerging evidence on how the lactate-lactylation axis drives immune evasion, therapy resistance, and TME remodeling, highlighting the therapeutic targets related to lactate and lactylation that dismantle this metabolic-epigenetic crosstalk.

Single-cell transcriptomic analysis identifies tissue-specific fibroblasts as the main modulators of myeloid cells in peritoneal metastasis of different origin

Colorectal cancer (CRC) peritoneal metastasis (CPM) is related to limited therapy options and poor prognosis. Although stromal cells heavily infiltrate most CPMs, interactions between different cell types in their microenvironment remain unclear. Here, we investigated tumor and distant normal tissue from CPM and CRC patients using single-cell RNA sequencing. Investigating the incoming and outgoing signals between cells revealed that fibroblasts dominate the CPM signaling landscape with myeloid cells as their strongest interaction partner. Using immunohistochemistry, we confirmed that fibroblasts co-localize with macrophages in the CPM microenvironment. A fibroblast sub-population detected only in CPM and normal peritoneum demonstrated immunoregulatory properties in co-culture experiments, and was further detected in additional peritoneal malignancies derived from ovarian and gastric origin. This novel fibroblast type and its communication with macrophages could be attractive targets for therapeutic interventions in CPM and potentially peritoneal surface malignancies in general.

Engineered oncolytic virus OH2-FLT3L enhances antitumor immunity via dendritic cell activation

The combination of oncolytic viruses (OVs) with other immunotherapies, such as immunostimulatory therapies, is a current research hotspot; however, optimizing their therapeutic potential remains to be fully explored. Here, we designed a novel oncolytic herpes simplex virus 2 expressing Fms-like tyrosine kinase 3 ligand (OH2-FLT3L), which induces an antitumor cytotoxic T cell immune response by activating dendritic cells (DCs). We found that OH2-FLT3L specifically infects tumor cells, induces immunogenic cell death (ICD), and releases a large number of tumor-specific antigens, which bound to danger signals and facilitated antigenic cross-presentation by DCs, significantly enhancing T cell activation and function. Experimental results showed that OH2-FLT3L significantly increased the proportion of activated DCs, enhanced the antitumor immune response, and effectively converted "cold" tumors into "hot" tumors. In addition, when combined with anti-PD-1 antibody, OH2-FLT3L further enhanced therapeutic efficacy. In conclusion, OH2-FLT3L, as a novel oncolytic virus, demonstrates the potential to enhance antitumor immune responses through DC activation.

Neuronal ALKAL2 and its ALK receptor contribute to the development of colitis-associated colorectal cancer

Tumor-infiltrating nerves play a critical role in cancer progression and treatment resistance. Our recent work identified ALKAL2, a ligand for the Anaplastic Lymphoma Kinase (ALK) receptor, as a key mediator of inflammatory pain, with its expression significantly elevated in TRPV1+ sensory neurons during inflammation. Here, we explored the regulation of neuronal ALKAL2 in a colitis-associated colorectal cancer (CAC) model. We found that neuronal ALKAL2 is upregulated at early stages of CAC, which in turn activates ALK signaling in the colonic mucosa. Notably, treating mouse colonic organoids with exogenous ALKAL2 triggered ALK activation. In vivo, mice treated with the ALK inhibitor lorlatinib at the onset of colitis exhibited a remarkable 90% reduction in tumor burden without significantly affecting overall inflammation. Moreover, activating TRPV1+ neurons using DREADD technology exacerbated tumor growth, whereas silencing these neurons significantly reduced it. These findings reveal that TRPV1+ nociceptors drive CAC progression via the ALKAL2/ALK pathway.

Tilianin regulates the proliferation, invasion and tumor immune microenvironment of thyroid cancer cells through the TLR4/NF-κB axis

Thyroid cancer is the most prevalent form of endocrine malignancy. Tilianin has demonstrated anti-tumor properties in ovarian cancer and non-small cell lung cancer (NSCLC), while its effects on thyroid cancer progression remain elusive. Hence, this research explored the role of Tilianin in thyroid cancer development and clarified the underlying mechanisms. The findings indicated that Tilianin reduced cell viability of TPC-1 (IC50 = 38.97 μM) and IHH4 (IC50 = 27.69 μM) cells dose-dependently and inhibited the expression of Ki-67. Additionally, Tilianin impaired the invasion capacity of TPC-1 and IHH4 cells, decreased the PD-L1 level, strengthened the CD8+T cell viability, and elevated the secretions of IFN-γ, IL-2, and TNF-α in CD8+T cells. Furthermore, Tilianin could suppress the activation of the TLR4/NF-κB pathway. The inhibitory effects of Tilianin on TPC-1 cell proliferation, invasion, and immune escape were reversed by overexpression of TLR4. In vivo, oral administration of Tilianin restrained thyroid cancer tumor growth, reduced the levels of Ki-67, PD-L1, TLR4, and p-NF-κB, and increased CD8+ T cell levels. In summary, Tilianin effectively restrained thyroid cancer cell proliferation, invasion, and tumor immune microenvironment through inactivating the TLR4/NF-κB pathway.

PC4 Potentially Predicts Chemoradiation-Induced Antitumor Immunity in Esophageal Squamous Cell Carcinoma

Chemoradiotherapy (CRT) induces an antitumor immune response in esophageal squamous cell carcinoma (ESCC), and thereby has enormous potential by itself and in combination with immune checkpoint inhibitors (ICI). Our previous studies indicated that human positive cofactor 4 (PC4) was an independent predictor of poor survival in patients with ESCC or lung cancer who were treated with definitive chemoradiation, with a mechanism involving the enhancement of nonhomologous end joining (NHEJ)-mediated DNA repair. Due to the important role of double-strand DNA (dsDNA) in the antitumor immune response, the present study aims to investigate PC4 as a predictor of pathological response and antitumor immune response in ESCC patients who underwent neoadjuvant CRT. In ESCC, low PC4 expression levels have significant power to predict pCR. In particular, pCR is 61.2% in patients with low PC4 expression, but only 23.4% in patients with high PC4. Both disease-free survival (DFS) and overall survival (OS) are significantly longer for patients with low PC4 than for those with high PC4. In agreement with our previous finding that PC4 participates in NHEJ-mediated DNA repair, our further analysis indicates that the expression of PC4 is not only significantly negatively correlated with cyto-free dsDNA in postoperative specimens, but also with tumor-infiltrating CD8+T lymphocytes (CD8+TILs) and GZMB+CD8+TILs, suggesting a possible mechanism that high PC4 negatively regulates the antitumor response and therefore results in poor prognosis. Together, our findings demonstrate that low expression of PC4 is a potential biomarker for predicting the antitumor immune response to chemoradiation in patients with operable locally advanced ESCC.

FAP-targeted delivery of radioiodinated probes: A progressive albumin-driven strategy for tumor theranostics

Fibroblasts activated protein (FAP) appears to be a promising target for tumor theranostics. However, the development of radioiodinated probes for FAP has been slow. In this study, a progressive abumin-driven strategy was adopted to improve the FAP-targeted delivery of radioiodinated probes for tumor theranostics. A series of FAP-targeted probes (namely [131I]IPB-FAPI, [131I]IPB-FAPI-A1, [131I]IPB-FAPI-A3, [131I]FSDD3I) were synthesized by incorporating an albumin-binding moiety (4-(p-iodophenyl)butyric acid, 4-IPBA) labeled with radioiodine. The specificity and binding characteristics of the radiotracers to FAP and human serum albumin (HSA) were confirmed. SPECT imaging results showed that the [131I]FSDD3I had more prominent tumor retention property and superior target-to-nontarget ratio, which were consistent with the biodistribution results. As expected, the FAP-targeted therapy with 11.1 MBq [131I]FSDD3I significantly inhibited tumor growth. In conclusion, this proof-of-concept study employed a progressive design strategy to enhance pharmacokinetics of radioiodinated FAP-targeted probes. Among these radioiodinated FAPI probes, 131I-labeled FSDD3I ([131I]FSDD3I) emerged as a standout candidate with superior competitive advantages for application in radioiodine-guided internal irradiation therapy.

Targeting Hyperglycemic Bone Pre-Metastatic Niche for Breast Cancer Bone Metastasis Therapy

Bone is the most common site of breast cancer metastasis, yet understanding the intricate mechanisms and potential therapeutic targets remains nascent. Here it is reported that breast cancer establishes a hyperglycemic bone pre-metastatic niche before migrating to bone tissue and further enhances glucose metabolism following metastatic colonization. An intervention strategy is subsequently proposed targeting glucose metabolism utilizing a biomimetic-engineered enzyme-based nanoplatform. This platform's membrane shielding reduces the interaction between engineered glucose oxidase and circulating glucose, while the engineered enzyme specifically targets glucose metabolism, enabling self-amplifying starvation combined with selective chemotherapy. Such precision can precisely inhibit breast cancer bone metastases and block distal tumor dissemination. This study provides novel insights into the role of glucose metabolism in the pre-metastatic niche and presents a proof-of-concept for metabolic-targeted strategies in breast cancer bone metastasis treatment. This approach holds significant promise for improving therapeutic outcomes in metastatic breast cancer by targeting the metabolic vulnerabilities of the bone microenvironment and halting systemic tumor spread.

Tumor microenvironment modulation innovates combinative cancer therapy via a versatile graphene oxide nanosystem

The tumor microenvironment (TME) emerges as a unique challenge to oncotherapy due to its intricate ecosystem containing diverse cell types, extracellular matrix, secreted factors, and neovascularization, which furnish tumor growth, progression, invasion, and metastasis. Graphene oxide (GO)-based materials have garnered increasing attention in cancer therapy owing to their vast specific surface area, flexible lamellar structure, and electronic-photonic properties. Recently, interactions of GO with the TME have been broadly investigated, including trapping biomolecules, catalysis, cancer stem cell targeting, immunoreactions, etc., which inspires combinative therapeutic strategies to overcome TME obstacles. Herein, we summarize TME features, GO modulating various dimensions of the TME, and a TME-triggerable drug delivery system and highlight innovation and merits in combinative cancer therapy based on TME modulation. This review aims to offer researchers deeper insights into the interactions between versatile GO nanomaterials and the TME, facilitating the development of rational and reliable GO-based nanomedicines for advanced oncotherapy.

Nutrient-gene therapy as a strategy to enhance CAR T cell function and overcome barriers in the tumor microenvironment

Cancer immunotherapy is transforming the treatment landscape of both hematological and solid cancers. Although T-cell-based adoptive cell transfer (ACT) therapies have demonstrated initial success, several recurrent obstacles limit their long-term anti-tumor efficacy, including: (1) lack of antigen specificity; (2) poor long-term survival of transplanted T cells in vivo; and (3) a hostile tumor microenvironment (TME). While numerous approaches have been explored to enhance the antigen specificity of Chimeric Antigen Receptor (CAR) T-cell therapies, the field still lacks an effective strategy to optimize the long-term retention and in vivo expansion of engrafted T cells within the TME-a critical factor for the durable efficacy of T-cell-based immunotherapies for both blood and solid cancers. Here, we hypothesize that the success of CAR T-cell therapy can be enhanced by targeting donor T cells' ability to compete with cancer cells for key nutrients, thereby overcoming T-cell exhaustion and sustaining durable anti-tumor function in the TME. To explore this hypothesis, we first provide a comprehensively review of the current understanding of the metabolic interactions (e.g., glucose metabolism) between T cells and tumor cells. To address the challenges, we propose an innovative strategy: utilizing nutrient gene therapy (genetic overexpression of glucose transporter 1, GLUT1) to fortify the metabolic competency of adoptive CAR T-cells, deprive tumors of critical metabolites and ATP, and disrupt the TME. Altogether, our proposed approach combining precision medicine (adoptive CAR T-cell therapy) with tumor metabolism-targeting strategies offers a promising and cost-effective solution to enhance the efficacy and durability of ACT therapies, ultimately improving outcomes for cancer patients.

Tumor microenvironment governs the prognostic landscape of immunotherapy for head and neck squamous cell carcinoma: A computational model-guided analysis

Immune checkpoint inhibition (ICI) has emerged as a critical treatment strategy for squamous cell carcinoma of the head and neck (HNSCC) that halts the immune escape of the tumor cells. Increasing evidence suggests that the onset, progression, and lack of/no response of HNSCC to ICI are emergent properties arising from the interactions within the tumor microenvironment (TME). Deciphering how the diversity of cellular and molecular interactions leads to distinct HNSCC TME subtypes subsequently governing the ICI response remains largely unexplored. We developed a cellular-molecular model of the HNSCC TME that incorporates multiple cell types, cellular states, and transitions, and molecularly mediated paracrine interactions. Simulation across the selected parameter space of the HNSCC TME network shows that distinct mechanistic balances within the TME give rise to the five clinically observed TME subtypes such as immune/non-fibrotic, immune/fibrotic, fibrotic only and immune/fibrotic desert. We predict that the cancer-associated fibroblast, beyond a critical proliferation rate, drastically worsens the ICI response by hampering the accessibility of the CD8 + killer T cells to the tumor cells. Our analysis reveals that while an Interleukin-2 (IL-2) + ICI combination therapy may improve response in the immune desert scenario, Osteopontin (OPN) and Leukemia Inhibition Factor (LIF) knockout with ICI yields the best response in a fibro-dominated scenario. Further, we predict Interleukin-8 (IL-8), and lactate can serve as crucial biomarkers for ICI-resistant HNSCC phenotypes. Overall, we provide an integrated quantitative framework that explains a wide range of TME-mediated resistance mechanisms for HNSCC and predicts TME subtype-specific targets that can lead to an improved ICI outcome.

Age- and diet-instructed metabolic rewiring of the tumor-immune microenvironment

The tumor-immune microenvironment (TIME) plays a critical role in tumor development and metastasis, as it influences the evolution of tumor cells and fosters an immunosuppressive state by intervening the metabolic reprogramming of infiltrating immune cells. Aging and diet significantly impact the metabolic reprogramming of the TIME, contributing to cancer progression and immune evasion. With aging, immune cell function declines, leading to a proinflammatory state and metabolic alterations such as increased oxidative stress and mitochondrial dysfunction, which compromise antitumor immunity. Similarly, dietary factors, particularly high-fat and high-sugar diets, promote metabolic shifts, creating a permissive TIME by fostering tumor-supportive immune cell phenotypes while impairing the tumoricidal activity of immune cells. In contrast, dietary restrictions have been shown to restore immune function by modulating metabolism and enhancing antitumor immune responses. Here, we discuss the intricate interplay between aging, diet, and metabolic reprogramming in shaping the TIME, with a particular focus on T cells, and highlight therapeutic strategies targeting these pathways to empower antitumor immunity.

New insights into Gremlin-1: A tumour microenvironment landscape re-engineer and potential therapeutic target

Gremlin-1 (GREM1), a well-known bone morphogenetic protein (BMP) antagonist, is highly expressed in various malignant tumours. However, the specific role of GREM1 in tumours remains controversial and may be attributed to the heterogeneity and complexity of the tumour microenvironment (TME). It is currently believed that GREM1 regulates the complex landscape of the TME, primarily by antagonising BMP signalling or BMP-independent pathways. Both GREM1 and BMP play dual roles in tumour progression. Therefore, the mutual crosstalk between tumour cells and tumour-associated fibroblasts and the regulation of various secreted factors in the TME affect the secretion level of GREM1, which in turn regulates the amplitude balance between GREM1 and BMP, affecting tumour progression. The inhibition of GREM1 activity in the TME can disrupt this amplitude balance and prevent the formation of a tumour-supportive microenvironment, demonstrating that GREM1 is a potential therapeutic target. In this study, we reviewed the specific signalling pathways via which GREM1 in the TME regulates epithelial-mesenchymal transition, construction of the tumour immune microenvironment, and maintenance of tumour cell stemness via BMP-dependent and BMP-independent regulation, and also summarised the latest clinical progress of GREM1.

Designing live bacterial therapeutics for cancer

Humans are home to a diverse community of bacteria, many of which form symbiotic relationships with their host. Notably, tumors can also harbor their own unique bacterial populations that can influence tumor growth and progression. These bacteria, which selectively colonize hypoxic and acidic tumor microenvironments, present a novel therapeutic strategy to combat cancer. Advancements in synthetic biology enable us to safely and efficiently program therapeutic drug production in bacteria, further enhancing their potential. This review provides a comprehensive guide to utilizing bacteria for cancer treatment. We discuss key considerations for selecting bacterial strains, emphasizing their colonization efficiency, the delicate balance between safety and anti-tumor efficacy, and the availability of tools for genetic engineering. We also delve into strategies for precise spatiotemporal control of drug delivery to minimize adverse effects and maximize therapeutic impact, exploring recent examples of engineered bacteria designed to combat tumors. Finally, we address the underlying challenges and future prospects of bacterial cancer therapy. This review underscores the versatility of bacterial therapies and outlines strategies to fully harness their potential in the fight against cancer.

Upregulation of YY1 in M2 macrophages promotes secretion of exosomes containing hsa-circ-0000326 via super-enhancers to facilitate prostate cancer progression

The transcription factor YY1 is significantly upregulated in M2 macrophages, which can facilitate the malignant progression of multiple cancers. However, the precise mechanisms underlying the influence of YY1-high M2 macrophages on prostate cancer (PCa) progression remain elusive. Therefore, this study aims to elucidate the specific mechanisms by which YY1-high M2 macrophages influence PCa progression. Cell proliferation was assessed through colony formation and CCK8 assays. To evaluate cell invasion and migration, Transwell and wound healing assays were utilized. We investigated the effects of exosomes derived from M2 macrophages overexpressing YY1 on PCa cells. Subsequently, circRNA microarrays and qRT-PCR identified a high level of hsa-circ-0000326 in exosomes. Nucleoplasmic isolation, luciferase reporter, RNA-pulldown assays elucidated the functions and downstream targets (miR-338-3p and AR) of hsa-circ-0000326. Chromatin immunoprecipitation sequencing, chromatin conformation capture, qRT-PCR, western blotting, and agarose-electrophoresis assays examined YY1's role in transcribing the hsa-circ-0000326 maternal gene MALAT1 as well as its modulation of QKI expression. Our results demonstrated that the secretion of exosomes enriched with hsa-circ-0000326 by YY1-overexpressing M2 macrophages contributes to PCa metastasis. Hsa-circ-0000326 functions as a competitive endogenous RNA against miR-338-3p to promote androgen receptor levels in PCa cells. Mechanistic investigations revealed that YY1 binds to the super-enhancer region of MALAT1 enhancing transcriptional activity for this gene. Simultaneously, YY1 upregulates QKI expression, facilitating splicing events leading to the formation of hsa-circ-0000326. Inhibiting exosomal hsa-circ-0000326 presents a potential therapeutic approach for treating metastatic PCa.

IL6 mediated cFLIP downregulation increases the migratory and invasive potential of triple negative breast cancer cell

c-FLIP (cellular FLICE-Like Inhibitor of Apoptotic protein) alias CFLAR (Cellular FADD-like apoptosis regulator) is an inhibitor of Caspase 8 and thus plays a key role in the regulation of extrinsic apoptotic pathway. However, the mechanisms of cFLIP regulation during the course of progression of cancer and it's involvement in tumour cell migration and invasion is yet to be known. Our TCGA data analysis has shown that cFLIP is downregulated in many cancers, including breast cancer, especially at the later stages. Next, we have analysed the role of cFLIP in breast cancer progression in In-vitro study. In doing so, we have used luminal breast cancer cell line MCF7 as non-aggressive and non-invasive breast cancer model and triple negative breast cancer cell lines MDA-MB-231, MDA-MB-468 and MDA-MB-453 as highly aggressive and invasive breast cancer cell model. When, we analysed and compared MCF7 and triple negative cell lines, we found a negative correlation between cFLIP expression pattern and metastasis which supported our In-silico study. Moreover, we found that Il6, one of the most prominent cytokines inside tumour microenvironment, helped in cFLIP downregulation via activation of p38 in MDA-MB-231 cell line. Not only that we have shown that cFLIP negatively regulated autophagy and this autophagy down-regulation resulted in decrease in metastasis. Thus, we have shown in an In-vitro model, for the first time, a complete interconnecting pathway in which IL6 mediated p38 activation directly influences metastasis by regulating autophagy via cFLIP downregulation.

Immunocompetent tumor-on-a-chip: A translational tool for drug screening and cancer therapy

Tumor is one of the major diseases endangering human health while establishing an efficient in vitro tumor microenvironment (TME) model, which is an effective way to reveal the nature of the tumor and develop therapeutic methods. In recent years, due to the continuous development of lab-on-a-chip technology and tumor biology, various tumor-on-a-chip models applied to oncology research have emerged. Among them, the Immunotherapy-on-a-chip (ITOC) platform stands out with its ability to reflect immunological behavior in the TME. It is a class of in vitro tumor-on-a-chip with immune activity, which has good performance and the ability to reproduce TME. It can highly simulate the complex pathophysiological characteristics of tumors and be used to study various features related to tumor biological behavior. Currently, many advantageous functions and application values of ITOC platforms have been discovered and applied to tumor drug screening and development, tumor immunotherapy, and personalized therapy. In conclusion, the tumor-on-a-chip platform is a highly promising model for medical oncology research. In this review, the background of the ITOC platform, key factors for constructing an ideal ITOC platform, and the specific applications of ITOC platforms in tumor research and treatment are introduced.

Polysaccharides from traditional Chinese medicine and their nano-formulated delivery systems for cancer immunotherapy

Cancer immunotherapy has evolved into a new generation strategy in the field of anti-tumor treatment. Polysaccharides derived from Traditional Chinese Medicine (TCM) are gaining recognition as powerful immunomodulators in cancer therapy, noted for their multi-target and multi-pathway actions. Owing to their beneficial properties such as water solubility, biocompatibility, and chemical structure modifiability, TCM polysaccharides can also serve as carriers for hydrophobic drugs in the development of innovative drug delivery systems, enhancing synergistic antitumor effects. In this article, we summarize the diverse mechanisms of immunoregulation by TCM polysaccharides in tumor therapy. The applications of these polysaccharides as both active ingredients and drug carriers within nanodelivery systems for cancer immunotherapy are also introduced. Additionally, extensive research on TCM polysaccharides in clinical settings has been collected. Furthermore, discussions are presented on the development prospects and challenges faced by these polysaccharides in the field of tumor immunotherapy. Our goal is to improve researchers' comprehension of TCM polysaccharides in cancer immunotherapy, providing promising strategies to optimize cancer treatment and benefit diverse patient populations.

Strategies for neoantigen screening and immunogenicity validation in cancer immunotherapy (Review)

Cancer immunotherapy stimulates and enhances antitumor immune responses to eliminate cancer cells. Neoantigens, which originate from specific mutations within tumor cells, are key targets in cancer immunotherapy. Neoantigens manifest as abnormal peptide fragments or protein segments that are uniquely expressed in tumor cells, making them highly immunogenic. As a result, they activate the immune system, particularly T cell‑mediated immune responses, effectively identifying and eliminating tumor cells. Certain tumor‑associated antigens that are abnormally expressed in normal host proteins in cancer cells are promising targets for immunotherapy. Neoantigens derived from mutated proteins in cancer cells offer true cancer specificity and are often highly immunogenic. Furthermore, most neoantigens are unique to each patient, highlighting the need for personalized treatment strategies. The precise identification and screening of neoantigens are key for improving treatment efficacy and developing individualized therapeutic plans. The neoantigen prediction process involves somatic mutation identification, human leukocyte antigen (HLA) typing, peptide processing and peptide‑HLA binding prediction. The present review summarizes the major current methods used for neoantigen screening, available computational tools and the advantages and limitations of various techniques. Additionally, the present review aimed to summarize experimental strategies for validating the immunogenicity of the predicted neoantigens, which will determine whether these neoantigens can effectively trigger immune responses, as well as challenges encountered during neoantigen screening, providing relevant recommendations for the optimization of neoantigen‑based immunotherapy.

GC-MSCs transcriptionally upregulate SALL4 in gastric cancer through miR-4669/TIMP3/β-catenin signaling

BACKGROUNDS

Gastric cancer-associated mesenchymal stem cells (GC-MSCs) as integral components of the tumor microenvironment potentiate gastric cancer growth and metastasis. SALL4 is aberrantly upregulated in gastric cancer and pivotal for malignant progression. Whether GC-MSCs is responsible for SALL4 upregulation and the underlying mechanisms remains elusive.

METHODS

Cancer growth and metastasis capacities were assessed by cell colony formation assay, transwell assay, and epithelial-mesenchymal transition protein detection in vitro as well as subcutaneous xenograft and peritoneal metastasis models in vivo. SALL4 was measured by qPCR, western blot and immunohistochemistry staining. Gain- and loss-functional analysis were performed for miRNA and target gene. β-catenin signaling was assessed by immunofluorescence staining and Top/FopFlash luciferase assay. Transcriptional regulation was conducted using chemicals, luciferase reporter and ChIP assay. Clinical tissues and TCGA-STAD database were included for expression profile, correlation and clinical relevance analysis.

RESULTS

GC-MSCs promoted gastric cancer growth and metastasis along with elevation of SALL4 and miR-4669 in cancer cells and tissues. Overexpression of miR-4669 mimicked GC-MSC effects, while miR-4669 knockdown eliminated their oncogenic roles. TIMP3 was identified as a target of miR-4669 and mediated its functions. TIMP3 overexpression counteracted GC-MSC-induced cancer progression and SALL4 expression. GC-MSCs activated SALL4 transcription through the miR-4669/TIMP3/β-catenin pathway. The regulatory axis was aberrantly expressed in gastric cancer tissues, correlated with each other in certain cancer tissues and associated with lymph node metastasis.

CONCLUSIONS

GC-MSCs transcriptionally upregulate SALL4 to facilitate gastric cancer cell growth and metastasis via miR-4669/TIMP3/β-catenin pathway, highlighting the crucial role of GC-MSCs in the aberrant upregulation of SALL4.

Infiltrating Natural Killer cells influence the efficacy of BCG immunotherapy in non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) consists of tumors restricted to the bladder urothelium or lamina propria, without invasion of the muscular layer. Intravesical BCG (Bacillus Calmette-Guérin) is widely used as an adjuvant therapy for patients with intermediate or high-risk NMIBC. However, a significant proportion of these patients fail to respond to BCG or recur after treatment. Moreover, despite decades of BCG usage, there are still no clinically validated biomarkers capable of predicting which patients will benefit from this treatment. Emerging evidence suggests that the tumor immune microenvironment influences the efficacy of BCG immunotherapy. In this context, our study aimed to assess, by immunohistochemistry, whether the abundance of immune cell subpopulations - Natural Killer (NK) cells, tumor-associated macrophages (TAMs), CD4 + T, CD8 + T, and FOXP3 + regulatory T (Treg) cells, or T cell ratios (CD4 +/CD8 + and FOXP3 +/CD8 +) - in NMIBC urothelium, prior to BCG, were associated with BCG response rate (RR) and recurrence-free survival (RFS) after treatment. We demonstrated that higher pretreatment NK cell count in the NMIBC urothelium is significantly associated with improved BCG RR and prolonged RFS after BCG immunotherapy. We hypothesize these results are associated with BCG-induced trained immunity, which has been proposed to be essential for the efficacy of BCG immunotherapy in bladder cancer. Once validated and further investigated by future studies, our findings may help to improve the stratification and treatment of patients with NMIBC.