LGMN as a Functionally Significant Prognostic and Immunoregulatory Biomarker in Glioma

Studies have shown that Legumain (LGMN) is a potential protease for immunosuppression in glioblastoma multiforme (GBM). Moreover, the elevated expression of LGMN in different types of cancers is linked to an unfavorable prognosis. However, it is still not clear about the expression of LGMN in gliomas, its links with clinical situations, the ways of immune infiltration, and its significance for the prognosis. The glioma data were obtained from online databases. We verified the expression, clinical correlation, immune microenvironment, and prognostic model of LGMN by combining RNA-seq, genomic data, spatial transcriptomics (ST-seq), proteomics data, scRNA-seq data, and RT-qPCR experiments. Moreover, we explored the biological processes of LGMN through enrichment analysis and conducted immunological analysis. In comparison with normal tissues, glioma tissues show enhanced expression of LGMN both at the gene and protein levels. The experimental findings indicated that the mRNA expression of LGMN was markedly increased in U87 and U251 cells compared with those in NHA cells. Glioma patients' overall survival (OS) may be reliably predicted by the expression of LGMN. Based on a functional enrichment study, LGMN is linked to biological functions such as cell signal transduction and immunology. LGMN has a positive relationship with immune checkpoints in glioma and is additionally related to immune infiltration. scRNA-seq analysis revealed LGMN expression in cell types like Mono/Macrophages, microglia, and malignant cells. LGMN expressed in glioma is intricately linked to molecular pathology, and has significant bearings on clinical prognosis. Meanwhile, there is a connection between LGMN expression and glioma immunity. Therefore, LGMN is a novel target for independent prognosis and immunotherapy strategies in glioma.