Transcriptome screening and functional validation of FN1 in the regulation of granulosa cell proliferation in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects 11%-13% of reproductive-age women worldwide and is pathologically associated with granulosa cell dysfunction. This study employed transcriptome sequencing of granulosa cells from PCOS patients and non-PCOS controls, followed by Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis. Key differentially expressed genes were validated by quantitative real-time PCR. Transcriptome analysis identified 157 upregulated and 71 downregulated mRNAs in PCOS granulosa cells, with enrichment in PI3K-Akt, MAPK, and TGF-beta signaling pathways. Six genes-NPTX2, FN1, CCN1, IDH1, ZCCHC17, and CREG1-were confirmed by qRT-PCR. Protein-protein interaction network analysis identified FN1 as a central hub gene. FN1 knockdown in KGN cells suppressed proliferation, induced apoptosis, and caused G1 phase arrest, accompanied by reduced Akt phosphorylation and altered expression of cyclin D1, p21, and p27. These findings suggest a potential association between FN1 and granulosa cell proliferative dysregulation in PCOS, warranting validation in primary cells and in vivo models.