ASS1 Enhances Anoikis Resistance via AMPK/CPT1A-mediated Fatty Acid Metabolism in Ovarian Cancer

Metastasis is the leading cause of death in ovarian cancer (OC), with anoikis resistance being a crucial step for detached OC cells survival. Despite extensive research, targeting anoikis resistance remians a challenge. Here, we identify argininosuccinate synthase 1 (ASS1), a key enzyme in urea cycle, is markedly upregulated in OC cells in detached culture and is associated with increased anoikis resistance and metastasis. Disruption of the AMP/ATP balance by elevated ASS1 activates AMPK and its downstream factor, CPT1A. Then, ASS1 enhances FAO, leading to higher ATP generation and lipid utilization. Inhibition of CPT1A reverses ASS1-induced FAO. Our study gives some new functional insights into OC metabolism and represents a shift from traditional views, expanding ASS1's relevance beyond nitrogen metabolism to fatty acid metabolism. It uncovers how ASS1-induced FAO disrupts the AMP/ATP balance, leading to AMPK activation. By identifying the ASS1/AMPK/CPT1A axis as crucial for OC anoikis resistance and metastasis, our study opens up new avenues for therapeutic interventions.