Tumour immune escape via P2X7 receptor signalling

Expanding the P2X7R toolbox: discovery of a novel Iodine-125 radioligand

This Journal Club article reviews a 2025 study by Qiu et al. that reports the development of a novel iodine-125 radioligand targeting the purinergic P2X7 receptor (P2X7R). The researchers created a small library of structurally modified P2X7R antagonists and identified compound 1c as a lead due to its high affinity and selectivity. Radiolabeling with iodine-125 produced [125I]1c with high yield and purity. Binding studies confirmed its strong nanomolar affinity, supporting its use in radioligand screening and potential applications in imaging P2X7R in inflammatory and neurodegenerative diseases. The study demonstrates the value of radiolabeled probes in drug discovery and purinergic signaling research.

The Ectonucleotidases CD39 and CD73 and the Purinergic Receptor P2X4 Serve as Prognostic Markers in Non-Small Cell Lung Cancer

BACKGROUND/OBJECTIVES

Purinergic signaling, which involves extracellular ATP (eATP), its metabolites, purinergic receptors and ectonucleotidases, plays a pivotal role in the tumor microenvironment (TME), impacting tumor progression and the antineoplastic immune response. In this study, the CD39, CD73, P2X4, and P2X7 expression in NSCLC tumor cells and the surrounding stroma of 139 resected patients was examined.

METHODS

The study included tissue samples from 139 NSCLC patients. Tissue microarrays (TMAs) were constructed using 1.0 mm cores from annotated tumor regions. Immunohistochemical staining for CD39, CD73, P2X4, and P2X4 was performed on 2 µm sections. TMA slides were digitized and analyzed with QuPath, where staining intensity was evaluated using a semi-quantitative H-score. Statistical analysis, including survival analysis, was performed using R, to assess the impact of biomarker expression on patient outcomes.

RESULTS

High CD39 expression in both tumor and stromal cells was significantly associated with prolonged PFS (respectively: p = 0.0058 and p = 0.0067), particularly in adenocarcinoma (ADC) patients (respectively: p = 0.01 and p = 0.023). In the multivariable Cox model, low CD73 expression in tumor cells correlated with longer PFS (HR: 0.47; 95% CI: [0.28, 0.8], p = 0.005), while low CD73 expression in stromal cells was linked to increased progression risk (HR: 4.81; 95% CI: [1.61, 14.4], p = 0.001). Neither P2X7 nor P2X4 demonstrated a consistent effect on PFS in univariable analyses; however, multivariable analyses suggested that P2X4 might play a prognostic role in NSCLCs (HR: 0.37; 95% CI: [0.19, 0.73], p = 0.003).

CONCLUSIONS

These findings underscore the importance of purinergic signaling in NSCLC prognosis and highlight the role of the ectonucleotidases CD39 and CD73 as potential therapeutic targets to enhance antineoplastic immune responses.

Relationship between purinergic P2X7 receptor and colorectal cancer: Research progress and future prospect

Purinergic P2X7 receptor (P2X7R) is a cellular transmembrane protein. Its activation leads to the release of cytokines, causing the migration and invasion of cancer cells. The expression of P2X7R is associated with tumor inflammation, survival, proliferation, angiogenesis, and metastasis in colorectal cancer (CRC). Evidence suggests that P2X7R expression appears to be epigenetically regulated by DNA methylation and miRNA regulation. With the in-depth study of P2X7R, the application of P2X7R agonists and antagonists has been discussed in the treatment of CRC. This article reviews the relationship between P2X7R and CRC, focusing on the research progress and future prospects of P2X7R in CRC diagnosis and treat-ment.

Hypoxia signaling in cancer: HIF-1α stimulated by COVID-19 can lead to cancer progression and chemo-resistance in oral squamous cell carcinoma (OSCC)

The potential implications of Coronavirus disease-2019 (COVID-19) on oral squamous cell carcinoma (OSCC) development, chemo-resistance, tumor recurrence, and patient outcomes are explored, emphasizing the urgent need for tailored therapeutic strategies to mitigate these risks. The role of hypoxia-inducible factor 1-alpha (HIF-1α) in OSCC studies has highlighted HIF-1α as a crucial prognostic marker in OSCC, with implications for disease prognosis and patient survival. Its overexpression has been linked to aggressive subtypes in early OSCC stages, indicating its significance as an early biomarker for disease progression. Moreover, dysplastic lesions with heightened HIF-1α expression exhibit a greater propensity for malignant transformation, underscoring its role in early oral carcinogenesis. Cancer patients, including those with OSCC, face an elevated risk of severe COVID-19 complications, which may further impact cancer progression and treatment outcomes. Understanding the interplay between COVID-19 infection, HIF-1α activation, and OSCC pathogenesis is crucial for enhancing clinical management strategies. So, insights from this review shed light on the significance of HIF-1α in OSCC tumorigenesis, metastasis formation, and patient prognosis. The review underscores the need for further research to elucidate the precise mechanisms through which HIF-1α modulates cancer progression and chemo-resistance in the context of COVID-19 infection. Such knowledge is essential for developing targeted therapeutic interventions to improve outcomes for OSCC patients.

Dys-regulated phosphatidylserine externalization as a cell intrinsic immune escape mechanism in cancer

The negatively charged aminophospholipid, phosphatidylserine (PS), is typically restricted to the inner leaflet of the plasma membrane under normal, healthy physiological conditions. PS is irreversibly externalized during apoptosis, where it serves as a signal for elimination by efferocytosis. PS is also reversibly and transiently externalized during cell activation such as platelet and immune cell activation. These events associated with physiological PS externalization are tightly controlled by the regulated activation of flippases and scramblases. Indeed, improper regulation of PS externalization results in thrombotic diseases such as Scott Syndrome, a defect in coagulation and thrombin production, and in the case of efferocytosis, can result in autoimmunity such as systemic lupus erythematosus (SLE) when PS-mediated apoptosis and efferocytosis fails. The physiological regulation of PS is also perturbed in cancer and during viral infection, whereby PS becomes persistently exposed on the surface of such stressed and diseased cells, which can lead to chronic thrombosis and chronic immune evasion. In this review, we summarize evidence for the dysregulation of PS with a main focus on cancer biology and the pathogenic mechanisms for immune evasion and signaling by PS, as well as the discussion of new therapeutic strategies aimed to target externalized PS. We posit that chronic PS externalization is a universal and agnostic marker for diseased tissues, and in cancer, likely reflects a cell intrinsic form of immune escape. The continued development of new therapeutic strategies for targeting PS also provides rationale for their co-utility as adjuvants and with immune checkpoint therapeutics.

Glioblastoma Tumor Microenvironment and Purinergic Signaling: Implications for Novel Therapies

Glial-origin brain tumors, particularly glioblastomas (GBMs), are known for their devastating prognosis and are characterized by rapid progression and fatal outcomes. Despite advances in surgical resection, complete removal of the tumor remains unattainable, with residual cells driving recurrence that is resistant to conventional therapies. The GBM tumor microenviroment (TME) significantly impacts tumor progression and treatment response. In this review, we explore the emerging role of purinergic signaling, especially the P2X7 receptor (P2X7R). Due to its unique characteristics, it plays a key role in tumor progression and offers a potential therapeutic strategy for GBM through TME modulation. We discuss also the emerging role of the P2X4 receptor (P2X4R) as a promising therapeutic target. Overall, targeting purinergic signaling offers a potential approach to overcoming current GBM treatment limitations.

The Purinergic Ligand-Gated Ion Channel 7 Receptor Promotes the Proliferation, Invasion, and Migration of Breast Cancer Cells

Purinergic ligand-gated ion channel 7 receptor (P2X7R) has essential functions in tumor proliferation, apoptosis, metastasis, and invasion, and the purpose of this study was to explore the effects of P2X7R on the biological behaviors of MCF-7 and MDA-MB-231 cells. A bioinformatics analysis of P2X7R expression in breast cancer was performed and its relationships with overall survival and immune cell infiltration were determined. P2X7R ion channel function was detected via a Fluo-4-AM assay. Proliferation, migration and invasion were investigated using CCK-8, scratch wound healing, and Transwell assays, respectively. The levels of P2X7R, JNK, p-JNK, Akt, p-Akt, E-cadherin, N-cadherin, vimentin and GAPDH were detected by western blotting. The role of P2X7R on the biological behaviors of MCF-7 cells was detected in vivo. Bioinformatics analysis revealed an obvious increase in the expression of P2X7R in breast cancer and differences were observed among the different subtypes. High expression of P2X7R was negatively correlated with overall survival and affected immune cell infiltration. The experimental results revealed that both types of cells express functional P2X7R. ATP and BzATP can promote proliferation, invasion, and metastasis after P2X7R activation; upregulate p-Akt, p-JNK, N-cadherin and vimentin; and downregulate E-cadherin compared with the control group, and the addition of the antagonist A438079 or oxATP or the knockdown of P2X7R could weaken these effects. The activation of P2X7R in breast cancer cells can promote their biological behaviors, indicating that P2X7R is a latent therapeutic target in breast cancer.

Persistent Activation of the P2X7 Receptor Underlies Chronic Inflammation and Carcinogenic Changes in the Intestine

Aberrant signaling through damage-associated molecular patterns (DAMPs) has been linked to several health disorders, attracting considerable research interest over the last decade. Adenosine triphosphate (ATP), a key extracellular DAMP, activates the purinergic receptor P2X7, which acts as a danger sensor in immune cells and is implicated in distinct biological functions, including cell death, production of pro-inflammatory cytokines, and defense against microorganisms. In addition to driving inflammation mediated by immune and non-immune cells, the persistent release of endogenous DAMPs, including ATP, has been shown to result in epigenetic modifications. In intestinal diseases such as inflammatory bowel disease (IBD) and colorectal cancer (CRC), consequent amplification of the inflammatory response and the resulting epigenetic reprogramming may impact the development of pathological changes associated with specific disease phenotypes. P2X7 is overexpressed in the gut mucosa of patients with IBD, whereas the P2X7 blockade prevents the development of chemically induced experimental colitis. Recent data suggest a role for P2X7 in determining gut microbiota composition. Regulatory mechanisms downstream of the P2X7 receptor, combined with signals from dysbiotic microbiota, trigger intracellular signaling pathways and inflammasomes, intensify inflammation, and foster colitis-associated CRC development. Preliminary studies targeting the ATP-P2X7 pathway have shown favorable therapeutic effects in human IBD and experimental colitis.