CD155 and its receptors in cancer immune escape and immunotherapy

Time series analysis combined with transcriptome sequencing to explore characteristic genes and potential molecular mechanisms associated with ultrasound-guided microwave ablation of glioma

OBJECTIVE

This study aimed to explore marker genes and their potential molecular mechanisms involved in US-guided MWA for glioma in mice.

METHOD

The differentially expressed genes (DEGs1 and DEGs2) and lncRNAs (DELs1 and DELs2) were obtained between Non (glioma tissues without MWA) and T0 groups (0h after MWA), as well as between Non and T24 groups (24h after MWA). The down-regulation cluster genes (CONDOWNDEGs) and upregulation cluster genes (CONUPDEGs) were identified by time series analysis. Candidate genes were obtained by overlapping CONDOWNDEGs with downregulation DEGs (DOWNDEGs)1 and DOWNDEGs2, as well as CONUPDEGs with up-regulation DEGs (UPDEGs)1 and UPDEGs2. The expressions of immune checkpoints and inflammatory factors, gene set enrichment analysis (GSEA), and protein subcellular localization were performed. The eXpression2Kinases (X2K), GeneMANIA, transcription factor (TF), and competing endogenous (ce) RNA regulatory networks were conducted. The expression of marker genes was validated by quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

Five marker genes (IL32, VCAM1, IL34, NFKB1 and CXCL13) were identified, which were connected with immune-related functions. Two immune checkpoints (CD96 and TIGIT) and six inflammatory factors played key roles in US-guided MWA for glioma. ceRNA regulatory networks revealed that miR-625-5p, miR-625-3p, miR-31-5p and miR-671-5p were associated with target genes. qRT-PCR indicated both IL32, VCAM1, and NFKB1 were potential markers under US-guided MWA-related time series analysis.

CONCLUSION

The use of US-guided MWA might be a practical method for influencing the function of target genes, regulating time frames to decrease inflammation, and stimulating immune responses in glioma therapy.

Herb pair of Huangqi-Danggui exerts anti-tumor immunity to breast cancer by upregulating PIK3R1

BACKGROUND

According to traditional Chinese medicine (TCM), drugs supplementing the vital energy, Qi, can eliminate tumors by restoring host immunity. The objective of this study is to investigate the underlying immune mechanisms of anti-tumor activity associated with Qi-supplementing herbs, specifically the paired use of Huangqi and Danggui.

METHODS

Analysis of compatibility regularity was conducted to screen the combination of Qi-supplementing TCMs. Using the MTT assay and a transplanted tumor mice model, the anti-tumor effects of combination TCMs were investigated in vitro and in vivo. High content analysis and flow cytometry were then used to evaluate cellular immunity, followed by network pharmacology and molecular docking to dissect the significant active compounds and potential mechanisms. Finally, the anti-tumor activity and the mechanism of the active ingredients were verified by molecular experiments.

RESULTS

There is an optimal combination of Huangqi and Danggui that, administered as an aqueous extract, can activate immunity to suppress tumor and is more effective than each drug on its own in vitro and in vivo. Based on network pharmacology analysis, PIK3R1 is the core target for the anti-tumor immunity activity of combined Huangqi and Danggui. Molecular docking analysis shows 6 components of the combined Danggui and Huangqi extract (quercetin, jaranol, isorhamnetin, kaempferol, calycosin, and suchilactone) that bind to PIK3R1. Jaranol is the most important component against breast cancer. The suchilactone/jaranol combination and, especially, the suchilactone/kaempferol combination are key for immunity enhancement and the anti-tumor effects of the extract.

CONCLUSIONS

The combination of Huangqi and Danggui can activate immunity to suppress breast cancer and is more effective than the individual drugs alone.

Targeting tumor-intrinsic SLC16A3 to enhance anti-PD-1 efficacy via tumor immune microenvironment reprogramming

Immunotherapy, especially immune checkpoint inhibitors, has revolutionized clinical practice within the last decade. However, primary and secondary resistance to immunotherapy is common in patients with diverse types of cancer. It is well-acknowledged that tumor cells can facilitate the formation of immunosuppressive microenvironments via metabolism reprogramming, and lactic acid, the metabolite of glycolysis, is a significant contributor. SLC16A3 (also named as MCT4) is a transporter mediating lactic acid efflux. In this study, we investigated the role of glycolysis in immunotherapy resistance and aimed to improve the immunotherapy effects via Slc16a3 inhibition. Bioinformatical analysis revealed that the expression of glycolysis-related genes correlated with less CD8+ T cell infiltration and increased myeloid-derived suppressor cells (MDSC) enrichment. We found that high glycolytic activity in tumor cells adversely affected the antitumor immune responses and efficacy of immunotherapy and radiotherapy. As the transporter of lactic acid, SLC16A3 is highly expressed in glycolytic B16-F10 (RRID: CVCL_0159) cells, as well as human non-small cell lung carcinoma. We validated that Slc16a3 expression in tumor cells negatively correlated with anti-PD-1 efficiency. Overexpression of Slc16a3 in tumor cells promoted lactic acid production and efflux, and reduced tumor response to anti-PD-1 inhibitors by inhibiting CD8+ T cell function. Genetic and pharmacological inhibition of Slc16a3 dramatically reduced the glycolytic activity and lactic acid production in tumor cells, and ameliorated the immunosuppressive tumor microenvironments (TMEs), leading to boosted antitumor effects via anti-PD-1 blockade. Our study therefore demonstrates that tumor cell-intrinsic SLC16A3 may be a potential target to reverse tumor resistance to immunotherapy.

Unleashing the power of immune checkpoints: Post-translational modification of novel molecules and clinical applications

Immune checkpoint molecules play a pivotal role in the initiation, regulation, and termination of immune responses. Tumor cells exploit these checkpoints to dampen immune cell function, facilitating immune evasion. Clinical interventions target this mechanism by obstructing the binding of immune checkpoints to their ligands, thereby restoring the anti-tumor capabilities of immune cells. Notably, therapies centered on immune checkpoint inhibitors, particularly PD-1/PD-L1 and CTLA-4 blocking antibodies, have demonstrated significant clinical promise. However, a considerable portion of patients still encounter suboptimal efficacy and develop resistance. Recent years have witnessed an exponential surge in preclinical and clinical trials investigating novel immune checkpoint molecules such as TIM3, LAG3, TIGIT, NKG2D, and CD47, along with their respective ligands. The processes governing immune checkpoint molecules, from their synthesis to transmembrane deployment, interaction with ligands, and eventual degradation, are intricately tied to post-translational modifications. These modifications encompass glycosylation, phosphorylation, ubiquitination, neddylation, SUMOylation, palmitoylation, and ectodomain shedding. This discussion proceeds to provide a concise overview of the structural characteristics of several novel immune checkpoints and their ligands. Additionally, it outlines the regulatory mechanisms governed by post-translational modifications, offering insights into their potential clinical applications in immune checkpoint blockade.

CD155 as an emerging target in tumor immunotherapy

CD155 is an immunoglobulin-like protein overexpressed in almost all the tumor cells, which not only promotes proliferation, adhesion, invasion, and migration of tumor cells, but also regulates immune responses by interacting with TIGIT, CD226 or CD96 receptors expressed on several immune cells, thereby modulating the functionality of these cellular subsets. As a novel immune checkpoint, the inhibition of CD155/TIGIT, either as a standalone treatment or in conjunction with other immune checkpoint inhibitors, has demonstrated efficacy in managing advanced solid malignancies. In this review, we summarize the intricate relationship between on tumor surface CD155 and its receptors, with further discussion on how they regulate the occurrence of tumor immune escape. In addition, novel therapeutic strategies and clinical trials targeting CD155 and its receptors are summarized, providing a strong rationale and way forward for the development of next-generation immunotherapies.

TIGIT: A potential immunotherapy target for gynecological cancers

Gynecological cancer represents a significant global health challenge, and conventional treatment modalities have demonstrated limited efficacy. However, recent investigations into immune checkpoint pathways have unveiled promising opportunities for enhancing the prognosis of patients with cancer. Among these pathways, TIGIT has surfaced as a compelling candidate owing to its capacity to augment the immune function of NK and T cells through blockade, thereby yielding improved anti-tumor effects and prolonged patient survival. Global clinical trials exploring TIGIT blockade therapy have yielded promising preliminary findings. Nevertheless, further research is imperative to comprehensively grasp the potential of TIGIT-based immunotherapy in optimizing therapeutic outcomes for gynecological cancers. This review primarily delineates the regulatory network and immunosuppressive mechanism of TIGIT, expounds upon its expression and therapeutic potential in three major gynecological cancers, and synthesizes the clinical trials of TIGIT-based cancer immunotherapy. Such insights aim to furnish novel perspectives and serve as reference points for subsequent research and clinical application targeting TIGIT in gynecological cancers.

Exosome-mediated communication between gastric cancer cells and macrophages: implications for tumor microenvironment

Gastric cancer (GC) is a malignant neoplasm originating from the epithelial cells of the gastric mucosa. The pathogenesis of GC is intricately linked to the tumor microenvironment within which the cancer cells reside. Tumor-associated macrophages (TAMs) primarily differentiate from peripheral blood monocytes and can be broadly categorized into M1 and M2 subtypes. M2-type TAMs have been shown to promote tumor growth, tissue remodeling, and angiogenesis. Furthermore, they can actively suppress acquired immunity, leading to a poorer prognosis and reduced tolerance to chemotherapy. Exosomes, which contain a myriad of biologically active molecules including lipids, proteins, mRNA, and noncoding RNAs, have emerged as key mediators of communication between tumor cells and TAMs. The exchange of these molecules via exosomes can markedly influence the tumor microenvironment and consequently impact tumor progression. Recent studies have elucidated a correlation between TAMs and various clinicopathological parameters of GC, such as tumor size, differentiation, infiltration depth, lymph node metastasis, and TNM staging, highlighting the pivotal role of TAMs in GC development and metastasis. In this review, we aim to comprehensively examine the bidirectional communication between GC cells and TAMs, the implications of alterations in the tumor microenvironment on immune escape, invasion, and metastasis in GC, targeted therapeutic approaches for GC, and the efficacy of potential GC drug resistance strategies.