Integrative Analysis Reveals Genes Causal Relation with Ovarian Cancer and aging

BACKGROUND: Exploring the correlation between ovarian cancer and aging has great significance for understanding the pathogenesis of ovarian cancer and formulating targeted therapeutic regimens. OBJECTIVE: This computational study aims to identify and validate key genes in monocyte subtypes related to ovarian cancer and aging, exploring potential causal relationships. METHODS: We collected single-cell RNA sequencing data (GSE157007, GSE184880), GWAS data (14,049 samples and 40,941 controls from a European population), and eQTL data of ovarian cancer and aging. Using R software packages like Seurat and singleR, we conducted data integration, quality control, cell classification, and differential gene expression analysis to identify intersecting monocyte subtype genes in ovarian cancer and aging. We employed summary data-based Mendelian randomization (SMR) analysis and Heterogeneity in Dependent Instruments (HEIDI) tests to pinpoint causal genes. Further single-cell functional analyses (gene switching, cell communication, metabolic pathway analysis), Bulk RNA sequencing validation, functional enrichment, and protein- protein interaction (PPI) analyses elucidated these genes' biological roles. RESULTS: The dataset included 123,280 cells, revealing differential gene expression in classical monocytes (104 genes), intermediate monocytes (43 genes), and myeloid dendritic cells (39 genes). SMR and HEIDI identified causal relationships for 7 genes in classical monocytes, 3 in intermediate monocytes, and 3 in myeloid dendritic cells with ovarian cancer. Bulk RNA seq validation confirmed six monocyte genes as causal in ovarian cancer and aging. TREM1, SERPINB2, and CD44 were upregulated, while DST was downregulated; SLC11A1 and PNRC1 showed contradictory patterns. Interactions with NK and T cells involved LGALS9 - CD44/45 receptors. Riboflavin metabolism was a common enriched pathway. CONCLUSION: This study identified six specific monocyte genes as potential therapeutic targets for ovarian cancer and aging.