Cancer immunotherapy has attracted great attention as a potential therapeutic approach for advanced malignancies due to its promising survival benefits. Comprehension of intricate interactions between the tumor microenvironment (TME) and immune checkpoint inhibitors (ICIs) is crucial for optimizing and improving immunotherapies. Currently, several experimental strategies are available to monitor this complexity but most of them fail to facilitate real-time monitoring of the immune response such as cellular phagocytosis and cytolysis. Consequently, the application of intravital imaging has been extensively studied in the domain of cancer immunotherapy. Intravital imaging has been proven to be a powerful real-time imaging modality that provides insights into intratumoral immune responses, cellular metabolic signatures, tumor vasculature, and cellular functions. This review aims to provide a comprehensive overview of the latest research on intravital imaging in cancer immunotherapy, especially addressing how intravital imaging sheds light on essential features of tumor immunity, immune infiltrations, tumor angiogenesis, and aids in the clarification of underlying immunotherapeutic mechanisms. Moreover, a variety of labeling tools, imaging windows and models for real-time visualizations of TME are also summarized. We will also investigate the full potential of using intravital imaging to circumvent the limitations of currently available imaging modalities, which hold promise to advent efficient immunotherapy for cancer patients. Graphical abstract

Background: Ankyrin repeat domain 53 (ANKRD53) plays an important role in maintaining chromosome integrity and stability, and chromosome instability is associated with cancer. Through integrative analysis, this study investigates the potential value of ANKRD53 in stomach adenocarcinoma (STAD). Methods: RNA-seq and scRNA-seq data were used for integrative analysis based on online databases. Expression of ANKRD53 was confirmed by RT-PCR after bioinformatic analysis. Kaplan–Meier and Cox regression analyses were performed to evaluate the prognostic value of ANKRD53 in STAD. Gene set enrichment analysis (GSEA) was performed to evaluate ANKRD53-related signaling pathways. In addition, the interaction of ANKRD53 with immunity was also investigated. Results: RT-PCR in STAD cell lines confirmed that ANKRD53 was downregulated in STAD samples compared to normal samples in the online databases. As an independent predictive biomarker, ANKRD53 was combined with other clinicopathological parameters to create a prognostic nomogram. Using GSEA, ANKRD53 was found to be involved in five pathways, including the TGF-β signaling pathway. Further investigation revealed that ANKRD53 was associated with immune checkpoint molecules, immunological pathways, and immunotherapy, in addition to MSI, TMB and neoantigens. In addition, scRNA-seq data revealed that ANKRD53 is mainly expressed in CD8⁺ T and dendritic cells. Conclusions: ANKRD53 is an important biomarker for STAD that deserves further attention.

Background: Tumor-associated macrophages (TAMs) constitute the most abundant immune cell population in the glioblastoma (GBM) tumor microenvironment. These macrophages critically influence multiple pathological processes in GBM, including recurrence, drug resistance, and immune evasion. However, the role of TREM1 in mediating proneural-to-mesenchymal transition (PMT) in TAMs remains unclear. Methods: Single-cell RNA sequencing analysis of 24,366 cells from seven GBM patients identified nine distinct cellular populations, including TAMs and malignant cells. Deconvolution analysis of TCGA mRNA-seq data complemented these findings. Differential expression analysis, weighted gene co-expression network analysis, and LASSO-Cox regression consistently identified TREM1 in TAMs as a PMT-associated biomarker. A co-culture system demonstrated TREM1’s influence on GBM cell malignancy and PMT progression in vitro , while intraperitoneal LP17 administration assessed its impact on tumor growth. Results: High TAM infiltration correlated significantly with poor clinical outcomes in GBM patients. Integrated scRNA-seq and mRNA-seq analyses established TREM1 in TAMs as a key PMT biomarker. LP17-mediated TREM1 inhibition attenuated PMT through modulation of the TLR4/PI3K/AKT/mTOR pathway and reduced tumor growth in vivo . Conclusion: TREM1 functions as an oncogenic biomarker in TAMs that drives GBM PMT via the TLR4/PI3K/AKT/mTOR axis, with inhibition of TREM1 demonstrating therapeutic potential in both ex vivo and in vivo models.

Background: Cancer immunotherapy has revolutionized the clinical management of cancer due to its promising survival benefits. Although FDA-approved cancer immunotherapy primarily leverages adaptive immunity for therapeutic efficacy, the critical role of innate immunity in tumor surveillance and eradication has been increasingly recognized. Recently, with the deepening of research in this field, macrophages have emerged as key effectors of the innate anti-tumor response, with antibody-dependent cellular phagocytosis (ADCP) becoming one of the primary mechanisms involved in cancer immunotherapy. As such, exploring ADCP-inducing monoclonal antibodies (mAbs) as forefront therapeutic regimens for patients with cancer is therefore highly sought after. Main body: Here, we broadly summarize recent translational advances in harnessing macrophage phagocytosis as a pivotal therapeutic approach in cancer immunotherapy, especially addressing how intravital imaging sheds light on ADCP in a real-time manner. Moreover, various challenges for targeting phagocytosis, strategies to enhance ADCP, and factors limiting its efficiency have also been summarized. We also investigated the potential of chimeric antigen receptor (CAR) macrophages as a next-generation therapeutic modality that bridges the innate and adaptive immune systems to induce robust anti-tumor immune responses. Conclusions: The insights presented in this review will set the scene for future investigations of possible alternative approaches that consider the antibody-dependent cellular phagocytosis for improved cancer immunotherapy.

Objective: To analyze the clinicopathological features, immunological characteristics, and prognostic value of APOBEC3C in gliomas, and to verify the specific mechanism by which it mediates the malignant progression of gliomas.Methods: mRNA‐seq data from 693 glioma patients in the CGGA database and 697 glioma patients in the TCGA were analyzed, respectively. In addition, single‐cell sequencing data were obtained from the CGGA database. Bioinformatics methods were applied to reveal the possible mechanisms of APOBEC3C‐mediated malignant progression of gliomas. Moreover, western blot, transwell, and cell‐scratch assays were used to explore the potential mechanisms of APOBEC3C‐mediated glioma invasion and migration.Results: APOBEC3C was enriched in malignant glioma subtypes and was a potential biomarker for mesenchymal subtypes in glioma patients. It was closely associated with glioma inflammation and immunity. Additionally, APOBEC3C is a potential independent prognostic factor for glioma, and inhibition of APOBEC3C expression can suppress the EMT process in glioma cells through the NF‐κB signaling pathway.Conclusion: APOBEC3C is a potential biomarker for glioma patients. It is closely related to the clinicopathology of glioma and may be a potential immunotherapy target for glioma patients.

It is difficult to differentiate between glioma recurrence and radiation brain necrosis after radiotherapy in the clinic, but it is very important for patients. The purpose of this study is to observe the clinical significance of cell-free DNA (cfDNA) in the differential diagnosis between them based on liquid biopsy. The SD rats were used to establish a glioma recurrence model and a radiation brain necrosis model. The successful establishment of the two models was verified by MRI, IVFI, HE staining, immunofluorescence and immunohistochemistry. Then, the changes of cfDNA in the two models (B1-SINE in plasma and mtDNA in urine) were analyzed by qPCR. After ionizing particle irradiation, qPCR results showed that the level of mtDNA in urine increased significantly at the 6th week and reached the peak at the 8th week. The B1-SINE of plasma samples increased significantly at the 4th week of irradiation and reached the peak at the 8th week. From week 8 to week 16, when radiation necrosis occurred, the levels of mtDNA in urine and B1-SINE in plasma increased significantly (p < 0.01). In the glioma recurrence model, there was no significant difference in urinary mtDNA level and plasma B1-SINE level between the normal group and the sham surgery group (p > 0.05). These findings demonstrate that cfDNA liquid biopsy, represented by plasma B1-SINE and urinary mtDNA, holds significant clinical translational potential as an early differential diagnostic marker for radiation-induced brain necrosis and glioma recurrence, warranting further validation of its sensitivity and specificity through ROC analysis in clinical samples.