Combining network toxicology with in vitro and in vivo experimental validation to investigate the toxicological mechanisms of phthalate exposure in promoting osteosarcoma.

Phthalates (PAEs), as ubiquitous persistent organic pollutants and typical endocrine disruptors (EDCs), have been shown in epidemiological studies to be associated with the development of osteosarcoma (OS). However, the molecular mechanisms by which PAEs regulate the occurrence and progression of OS remain unclear. Accordingly, this study integrates network toxicology, multi-omics analysis, molecular docking, and in vitro/vivo experiments to systematically elucidate the toxicological mechanism of phthalate in promoting osteosarcoma. Specifically, this study identified COMT and SFPQ as key targets regulated by PAEs in OS, and these targets demonstrated good diagnostic performance for OS. ssGSEA confirmed that COMT and SFPQ are significantly associated with the abundance of 11 dysregulated immune cell types in OS, and single-cell sequencing revealed that COMT and SFPQ are specifically enriched in key cell populations such as osteoblasts and proliferating cells within OS tissue. Subsequently, molecular docking experiments validated that PAEs exhibit a specific binding affinity for both COMT and SFPQ. Finally, in vivo, PAE exposure induced SFPQ upregulation and COMT downregulation in normal tissues, shifting their expression pattern toward the OS-associated pattern, accompanied by enhanced cell migration and invasion in vitro. In summary, this study elucidated the molecular mechanism by which PAEs regulate OS through COMT and SFPQ as core targets using multidimensional techniques. This not only fills a gap in the microscopic mechanisms of PAE-mediated OS but also lays the foundation for developing targeted therapeutic strategies for OS associated with environmental exposure.