51P - Unlocking CAR-T cell potential: Lipid metabolites in overcoming exhaustion in ovarian cancer

Background

Challenges persist in CAR-T cell therapy for solid tumors, notably due to immune exhaustion within the tumor microenvironment. Mesothelin (MSLN) has emerged as a pivotal target for CAR-T therapy in ovarian cancer, yet overcoming functional exhaustion remains a critical hurdle. This study explores the role of lipid metabolites in modulating anti-MSLN CAR-T cell exhaustion, aiming to enhance therapeutic outcomes.

Methods

Anti-MSLN CAR-T cells were engineered to target ovarian cancer cells with high MSLN expression for in vitro and in vivo experiments. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified oxylipin 12-HETE as critical in CAR-T cell exhaustion. High-throughput virtual screening (HTVS) identified an inhibitor targeting B7-H3.

Results

Our findings demonstrate that increased infiltration of T cells within mouse tumor models correlates with reduced tumor burden, attributed to 12-HETE-induced lipid peroxidation mediated via the GPR31 pathway. This process significantly impairs cancer cell viability and cytotoxic functionality of CAR-T cells. Mechanistically, we elucidate that interaction between the B7-H3 protein and HRAS in ovarian cancer cells inhibits FOXO3 regulatory activity, subsequently influencing 12-LOX expression critical in lipid metabolism regulation. Importantly, HTVS identified HI-TOPK-032 as an effective inhibitor that restores CAR-T cell infiltration and functionality, synergizing notably with anti-PD-1 blockade. Notably, HI-TOPK-032 amplifies the anticancer effects of CAR-T cells in patient-derived xenograft models of ovarian cancer characterized by elevated B7-H3 and 12-LOX expression.

Conclusions

This study underscores the pivotal role of lipid metabolism in CAR-T cell therapy efficacy against MSLN-expressing solid tumors. Our findings highlight the innovative strategy of targeting lipid pathways to mitigate immune exhaustion, presenting HI-TOPK-032 as a promising adjunct to enhance CAR-T cell therapy outcomes. These insights advance the understanding of immune modulation in ovarian cancer and propose a novel therapeutic approach poised for clinical translation.

Legal entity responsible for the study

The authors.

Funding

Capital Medical University Laboratory for Clinical Medicine and Gynecological Tumor Precise Diagnosis and Treatment Innovation Studio.

Disclosure

All authors have declared no conflicts of interest.