Crosstalk between CD180-overexpression macrophages and glioma cells worsens patient survival through malignant phenotype promotion and immunosuppressive regulation.

Background: Understanding the molecular mechanisms in immunosuppressive regulation is crucial for improving immunotherapeutic strategies. Macrophages, the major immune cells in tumor microenvironment (TME), play a dual role in tumor progression. CD180, primarily expressed in macrophages, remains unclear and requires further investigation.

Methods: RNA-seq data were obtained to analyze CD180 expression in gliomas and assess its prognostic value. The comprehensive immune infiltration analysis was performed. Single-cell RNA-seq (scRNA-seq) data were used to examine CD180 expression distribution at the cellular level. CD180-overexpression macrophages were co-cultured with three glioma cell lines. The effects on glioma cell behavior were evaluated through qRT-PCR, Western blot, CCK-8 assay, EdU assay, Transwell assay, TUNEL assay, and flow cytometry. Differentially expressed genes (DEGs) and their potential biological functions were analyzed between different CD180 expression groups. Consensus clustering was used to identify CD180-related glioma subtypes.

Results: CD180 was significantly upregulated in glioma samples and associated with poor prognosis. High CD180 expression was correlated with increased immune cell infiltration, particularly macrophages, and elevated levels of immune checkpoints. Analysis of scRNA-seq data revealed the predominant expression of CD180 in macrophages within the glioma TME. In vitro experiments demonstrated that CD180-overexpression macrophages promoted glioma cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), while decreasing apoptosis. Mutations in TP53 and PTEN were significantly more prevalent in the high CD180 expression group. We identified nine chemotherapeutic agents that were more effective in glioma patients with high CD180 expression. Additionally, two CD180-related glioma subtypes with distinct prognosis were identified.

Conclusions: This study confirmed the prognostic role of CD180 in glioma and its involvement in immunosuppressive regulation and malignant phenotype promotion. Therefore, CD180 was considered as a promising target for immunotherapeutic strategies in glioma treatment.