From basic research to clinical application: targeting fibroblast activation protein for cancer diagnosis and treatment.

Abstract

This study aims to review the multifaceted roles of a membrane protein named Fibroblast Activation Protein (FAP)expressed in tumor tissue, including its molecular functionalities, regulatory mechanisms governing its expression,prognostic significance, and its crucial role in cancer diagnosis and treatment. Articles that have uncovered the regulatory role of FAP in tumor, as well as its potential utility within clinical realms,spanning diagnosis to therapeutic intervention has been screened for a comprehensive review. Our review reveals that FAP plays a pivotal role in solid tumor progression by undertaking a multitude of enzymaticand nonenzymatic roles within the tumor stroma. The exclusive presence of FAP within tumor tissues highlights itspotential as a diagnostic marker and therapeutic target. The review also emphasizes the prognostic significance ofFAP in predicting tumor progression and patient outcomes. Furthermore, the emerging strategies involving FAPIinhibitor (FAPI) in cancer research and clinical trials for PET/CT diagnosis are discussed. And targeted therapyutilizing FAP including FAPI, chimeric antigen receptor (CAR) T cell therapy, tumor vaccine, antibody-drugconjugates, bispecific T-cell engagers, FAP cleavable prodrugs, and drug delivery system are also introduced. FAP's intricate interactions with tumor cells and the tumor microenvironment make it a promising target fordiagnosis and treatment. Promising strategies such as FAPI offer potential avenues for accurate tumor diagnosis,while multiple therapeutic strategies highlight the prospects of FAP targeting treatments which needs further clinicalevaluation.