ULK1 is required for autophagy and promotes metastatic progression in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is a leading cause of gynecological cancer mortality, driven largely by late diagnosis and chemo-resistant disease. While autophagy plays a critical role in the survival of EOC spheroids during metastasis, the role of ULK1, a key regulator of autophagy, in EOC progression remains unclear. To investigate this, we utilized CRISPR/Cas9 technology to delete ULK1 in EOC cell lines OVCAR8 and HEYA8, and the immortalized fallopian tube epithelial cell line FT190. Immunoblotting confirmed ULK1 deletion, which disrupted autophagy by blocking LC3 processing, causing p62 accumulation, and decreasing Beclin-1 phosphorylation. Culture-based assays revealed that ULK1 knockout decreased EOC spheroid cell viability due to increased apoptosis, and its loss impaired organoid growth. In vivo xenograft models demonstrated that ULK1 loss significantly reduced tumor burden and metastatic potential. These in vivo findings were supported by results from mesothelial clearance assays, which showed reduced spheroid invasion by ULK1 knockout cells. Proteomic analyses of OVCAR8 spheroids revealed dysregulation due to ULK1 loss in key signaling pathways, including MAPK, mTOR-PI3K-AKT, and apoptosis regulation. Overall, this study highlights ULK1 as a critical regulator of multiple steps of EOC growth and metastasis, underscoring its potential as a novel therapeutic target in advanced ovarian cancer.