Meiotic nuclear divisions 1 (MND1) correlates with the immune microenvironment and predicts poor prognosis in breast cancer

Meiotic nuclear divisions 1 (MND1) has been described as an oncogene in several cancers; however, its role in breast cancer remains poorly characterized. MND1 expression and prognostic significance were analyzed across pan-cancer datasets from TCGA and further validated in breast cancer using multiple independent databases. The functions and signaling pathways were investigated using GO, KEGG analyses, and GSEA. Immune cell infiltration was estimated by ssGSEA and validated using methods such as CIBERSORT, EPIC, and quanTIseq, with tumor purity corrected using ESTIMATE. Associations with immune checkpoint expression and TIDE scores were evaluated. The functions of MND1 were also explored through in vitro experiments. MND1 was upregulated and associated with poor prognosis across multiple cancer types, including breast cancer, where it was identified as an independent prognostic indicator. Enrichment analysis revealed that MND1 was significantly associated with multiple tumor- and immune-related pathways. MND1 expression was associated with altered infiltration of Th1/2 cells, aDC, Tregs and B cells. Moreover, the high MND1 group exhibited elevated immune checkpoint gene expression, lower TIDE scores, and higher MSI scores. In vitro, MND1 promoted breast cancer cell proliferation and migration. MND1 is an independent prognostic factor in breast cancer and is associated with immune microenvironmental features, suggesting its potential as a prognostic biomarker.