PAK2 mediates PhIP-induced proliferative and oxidative stress responses in colorectal cancer cells

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a dietary heterocyclic amine generated during high-temperature cooking, has been implicated in colorectal cancer (CRC); however, its underlying molecular mechanisms remain incompletely understood. In this study, we provide experimental evidence that PhIP induces proliferative and oxidative stress-related responses in colorectal cancer cells through a PAK2-dependent mechanism. In vitro assays demonstrated that PhIP exposure robustly enhanced colorectal cancer cell proliferation in both time- and concentration-dependent manners and induced marked redox imbalance, as evidenced by decreased HO-1 expression and concomitant upregulation of catalase (CAT) and SOD2. Critically, siRNA-mediated knockdown of PAK2 significantly abrogated PhIP-induced proliferative effects and effectively reversed oxidative stress-related alterations, establishing PAK2 as a functional mediator rather than a passive biomarker. Consistently, in vivo xenograft experiments further demonstrated that PAK2 silencing markedly suppressed colorectal tumor growth, supporting a general tumor-promoting role of PAK2 rather than directly demonstrating PhIP-induced carcinogenesis in vivo. Mechanistically, integrative analyses combining network toxicology, Mendelian randomization, multi-omics profiling, and molecular docking prioritized PAK2 as a candidate hub gene potentially connecting PhIP-related targets with CRC-associated molecular features and supported a stable binding pattern between PhIP and PAK2 in silico. Functional enrichment analyses further indicated that PAK2-associated signatures are involved in oxidative stress, mitochondrial metabolism, and cell cycle regulation. Collectively, these findings support PAK2 as a functional mediator of PhIP-induced cellular responses in colorectal cancer cells, while the in vivo data demonstrate the broader role of PAK2 in colorectal tumor growth.