Flow cytometry data for male breast cancer sample

Male breast cancer (MBC) is a rare but aggressive malignancy with poor outcomes. The cellular states and immunological characteristics of MBC remain unclear. We performed a comparative analysis for transcriptomic data of 111,038 cells from six ER+ MBC and thirteen ER+ female breast cancer (FBC) samples. Single-cell T cell receptor sequencing (scTCR-seq) was also used to explore the difference of T cell clones between MBC and FBC. Results of single-cell RNA sequencing (scRNA-seq), bulk transcriptome, and immunohistochemistry consistently demonstrated that MBC had a significantly lower degree of T cell infiltration than FBC. Different characteristics of T cell subpopulations between MBC and FBC were identified. T cells in MBC showed activation of p38 MAPK and lipid oxidation pathways, indicating the dysfunctional state. In contrast, T cells in FBC exhibited a higher expression level of cytotoxic markers such as GZMK and KLRB1, and activated pathways mediated by immune-modulatory cytokines. Moreover, we identified the inhibitory interactions between cancer cells and T cells in the MBC microenvironment, such as cell-cell communications mediated by TGF-β, TIGIT, and VSIR. Our study will provide important information for understanding the tumor immunology and metabolism of MBC, and promote the development of effective treatments for MBC.