The Knockdown of ETV4 Inhibits the Papillary Thyroid Cancer Development by Promoting Ferroptosis Upon SLC7A11 Downregulation.

Papillary thyroid cancer (PTC) is one of the most prevalent endocrine malignancies. Herein, we aimed to provide a new viewpoint for the PTC progression and explore a new target for the effective therapy for PTC. We found that E26 transformation specific (ETS) variant 4 (ETV4, an ETS family transcription factor) was upregulated in PTC tissues and cells. In vitro experiments exhibited that silencing ETV4 suppressed PTC cell proliferation and cell cycle progression, while the overexpression of ETV4 gained the opposite results. Dual-luciferase reporter assay highlighted that ETV4 could upregulate the solute carrier family 7 member 11 (SLC7A11, a key role for cysteine uptake in ferroptosis) transcription by binding to its promoter region directly. Moreover, the viability inhibition of PTC cells induced by the knockdown of ETV4 was at least partly through the promotion of ferroptosis upon the downregulation of SLC7A11. In in vivo experiment, the results showed that the downregulation of ETV4 repressed the tumor development through the low expression of SLC7A11, and the ETV4 overexpression obtained the contrary effects. Overall, the data suggested that the knockdown of ETV4 suppressed the PTC progression by promoting ferroptosis upon SLC7A11 downregulation.