METTL14 induces ferroptosis to inhibit colorectal cancer progression by inhibiting TRIB3 via an m6A-YTHDF2-dependent manner

Abstract

Ferroptosis, a form of regulated cell death caused by iron-dependent accumulation of lipid peroxides, is recently demonstrated as a vital player in cancer development. Tribbles homolog 3 (TRIB3) is a contributing factor to the malignant progression of several human cancers, including colorectal cancer (CRC). However, its regulatory effect and mechanism in CRC are obscure. qRT-PCR and western blot assays determined the mRNA and protein expression of TRIB3, methyltransferase-like 14 (METTL14), and YT521-B homology domain family 2 (YTHDF2). Cell ferroptosis was evaluated by measuring the levels of intracellular reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), and glutathione (GSH). Cell malignant progression were assessed by CCK-8, EdU, transwell, and xenograft assays. The m6A sites of TRIB3 were confirmed using m6A RNA immunoprecipitation (Me-RIP) assay. The binding between TRIB3 and METTL14 or YTHDF2 was validated using RIP or luciferase reporter experiments. We observed higher expression of TRIB3 and lower expression of METTL14 in CRC tissues and cells. Knockdown of TRIB3 increased ferroptosis by promoting the generation of intracellular ROS, lipid ROS, and MDA and inhibiting the production of GSH. Suppressing TRIB3 also decreased tumor growth by increasing ferroptosis in mice. Mechanistically, knockdown of METTL14 reduced the m6A modification of TRIB3 and elevated TRIB3 mRNA expression. Moreover, METTL14-methylated TRIB3 was was recognized by YTHDF2, which resulted in the degradation of TRIB3 mRNA. TRIB3 overexpression reversed METTL14-mediated ferroptosis in CRC cells. Silencing YTHDF2 also abrogated the promotive effect of METTL14 on ferroptosis in CRC cells. Additionally, knockdown of TRIB3 induced ferroptosis by inactivating the SLC7A11/GPX4 signaling. METTL14 suppressed the SLC7A11/GPX4 signaling by targeting TRIB3. METTL14 suppressed CRC cell proliferation, migration, and invasion by downregulating TRIB3. Our findings suggest that METTL14 suppressed TRIB3 expression via an m6A-YTHDF2-dependent manner, thus inducing ferroptosis to inhibit the malignant progression of CRC. TRIB3 is potentially exploited as a molecular target for CRC treatment based on ferroptosis.