Single-cell RNA sequencing identifies ZBP1-dependent mechanisms in OSCC progression

Abstract

Oral squamous cell carcinoma (OSCC) is a highly aggressive head and neck malignancy with a poor prognosis associated with its complex tumor microenvironment. Cancer-associated fibroblasts (CAFs) contribute to tumor progression by secreting various signaling molecules. This study investigates the molecular mechanism through which Z-DNA-binding protein 1 (ZBP1) promotes OSCC development through CAF regulation. To this end, orthotopic MOC1 transplantation and 4NQO-induced carcinogenesis OSCC models were established with Zbp1^-/- mice. Single-cell RNA sequencing (scRNA-seq) analyzed cellular heterogeneity and signaling network alterations in the tumor microenvironment. An in vitro CAF induction model combined with a Transwell co-culture system clarified the molecular mechanism of ZBP1. Finally, the role of the ZBP1-CCL7/CCR1 signaling axis in promoting OSCC progression was evaluated via in vivo recombinant CCL7 protein rescue and CCR1 antagonist (BX471) intervention. ZBP1 is highly expressed in OSCC tissues, while its deficiency inhibits tumor growth and proliferation. Proliferation-related pathways (e.g., E2F targets, MYC targets, cell cycle) are downregulated while immune activation signatures (e.g., interferon response, p53 pathway, TNF-α/NF-κB signaling) are upregulated in Zbp1^-/- tumor cells. Cellular interaction analysis and ligand-receptor network profiling demonstrated significant attenuation of the CCL7-CCR1 signaling axis between CAFs and tumor cells. ZBP1 deficiency reduces CCL7 expression in CAFs, diminishing their ability to promote tumor cell proliferation, migration, and invasion via the CCL7/CCR1 axis. Exogenous CCL7 supplementation partially restores tumor growth in Zbp1^-/- mice, indicating that ZBP1 bridges CAF-tumor cell communication through the CCL7-CCR1 axis. This study highlights ZBP1 as crucial for OSCC progression by regulating CCL7 expression in CAFs to activate CCR1 signaling in tumor cells. This provides insights into the regulatory mechanisms within the OSCC microenvironment, offering a potential therapeutic strategy for targeted interventions.