Overexpression of TFPI‐2 Suppresses Colorectal Cancer Progression by Inducing Ferroptosis via NF‐κB Signaling

ABSTRACT Colorectal cancer (CRC) is a major global malignancy, with ferroptosis emerging as a key regulator of its progression. Although TFPI‐2, a kunitz‐type serine protease inhibitor, was reported to have important clinical implications for CRC diagnosis and prognosis, few studies have investigated its functional role in CRC cells, and its involvement in ferroptosis remains unknown. TFPI‐2 expression in CRC and adjacent normal tissues was detected by IHC, RT‐qPCR, and Western blot. Plasmid transfection was used to silence or overexpress TFPI‐2 in CRC cells, followed by functional assays including CCK‐8 assays, EdU staining, Transwell assays, and EMT marker detection. In vivo tumor growth was evaluated using a xenograft model. Ferroptosis was assessed by measuring ROS, Fe²⁺ levels, MDA, GSH, and expression of key regulators (GPX4, TFR1, FSP1). Mechanistic insights from analyses of p65 and IκBα were obtained through RT‐qPCR, Western blot and immunofluorescence. To investigate the involvement of the NF‐κB signaling pathway, HCT116 cells were treated with the NF‐κB inhibitor Bay 11‐7082. CRC tissues exhibited decreased TFPI‐2 expression. Overexpressing TFPI‐2 suppressed CRC cell proliferation, invasion, and EMT, whereas TFPI‐2 knockdown exacerbated these malignant phenotypes. These findings were further validated in xenograft models, where TFPI‐2 exerted tumor‐suppressive effects. Mechanistically, TFPI‐2 knockdown inhibited ferroptosis by promoting NF‐κB pathway activity. This study reveals that TFPI‐2 suppresses CRC progression by inducing ferroptosis through NF‐κB signaling, providing new insights for future CRC therapy.