The N6-methyladenosine modification enhances ferroptosis resistance through inhibiting SLC7A11 mRNA deadenylation in hepatoblastoma.

Solute carrier family 7 member 11 (SLC7A11) is overexpressed in multiple human tumours and functions as a transporter importing cystine for glutathione biosynthesis. It promotes tumour development in part by suppressing ferroptosis, a newly identified form of cell death that plays a pivotal role in the suppression of tumorigenesis. However, the role and underlying mechanisms of SLC7A11-mediated ferroptosis in hepatoblastoma (HB) remain largely unknown. Reverse transcription quantitative real-time PCR (RT-qPCR) and western blotting were used to measure SLC7A11 levels. Cell proliferation, colony formation, lipid reactive oxygen species (ROS), MDA concentration, 4-HNE, GSH/GSSG ratio and cell death assays as well as subcutaneous xenograft experiments were used to elucidate the effects of SLC7A11 in HB cell proliferation and ferroptosis. Furthermore, MeRIP-qPCR, dual luciferase reporter, RNA pulldown, RNA immunoprecipitation (RIP) and RACE-PAT assays were performed to elucidate the underlying mechanism through which SLC7A11 was regulated by the m6A modification in HB. SLC7A11 expression was highly upregulated in HB. SLC7A11 upregulation promoted HB cell proliferation in vitro and in vivo, inhibiting HB cell ferroptosis. Mechanistically, SLC7A11 mRNA exhibited abnormal METTL3-mediated m6A modification, which enhanced its stability and expression. IGF2 mRNA-binding protein 1 (IGF2BP1) was identified as the m6A reader of SLC7A11, enhancing SLC7A11 mRNA stability and expression by inhibiting SLC7A11 mRNA deadenylation in an m6A-dependent manner. Moreover, IGF2BP1 was found to block BTG2/CCR4-NOT complex recruitment via competitively binding to PABPC1, thereby suppressing SLC7A11 mRNA deadenylation. Our findings demonstrated that the METTL3-mediated SLC7A11 m6A modification enhances HB ferroptosis resistance. The METTL3/IGF2BP1/m6A modification promotes SLC7A11 mRNA stability and upregulates its expression by inhibiting the deadenylation process. Our study highlights a critical role of the m6A modification in SLC7A11-mediated ferroptosis, providing a potential strategy for HB therapy through blockade of the m6A-SLC7A11 axis.

Liu L ，He J ，Sun G ，Huang N ，Bian Z ，Xu C ，Zhang Y ，Cui Z ，Xu W ，Sun F ，Zhuang C ，Man Q ，Gu S ... -  《Clinical and Translational Medicine》

N6-methyladenosine modification of LATS2 promotes hepatoblastoma progression by inhibiting ferroptosis through the YAP1/ATF4/PSAT1 axis.

Ferroptosis has attracted extensive interest from cancer researchers due to its substantial potential as a therapeutic target. The role of LATS2, a core component of the Hippo pathway cascade, in ferroptosis initiation in hepatoblastoma (HB) has not yet been investigated. Furthermore, the underlying mechanism of decreased LATS2 expression remains largely unknown. In the present study, we demonstrated decreased LATS2 expression in HB and that LATS2 overexpression inhibits HB cell proliferation by inducing ferroptosis. Increased LATS2 expression reduced glycine and cysteine concentrations via the ATF4/PSAT1 axis. Physical binding between YAP1/ATF4 and the PSAT1 promoter was confirmed through ChIP‒qPCR. Moreover, METTL3 was identified as the writer of the LATS2 mRNA m6A modification at a specific site in the 5' UTR. Subsequently, YTHDF2 recognizes the m6A modification site and recruits the CCR4-NOT complex, leading to its degradation by mRNA deadenylation. In summary, N6-methyladenosine modification of LATS2 facilitates its degradation. Reduced LATS2 expression promotes hepatoblastoma progression by inhibiting ferroptosis through the YAP1/ATF4/PSAT1 axis. Targeting LATS2 is a potential strategy for HB therapy.

Zhu G ，Xie Y ，Bian Z ，Ma J ，Zhen N ，Chen T ，Zhu J ，Mao S ，Tang X ，Liu L ，Gu S ，Ding M ，Pan Q ... -  《International Journal of Biological Sciences》

Silencing of METTL3 suppressed ferroptosis of myocardial cells by m6A modification of SLC7A11 in a YTHDF2 manner.

Tang Z ，Huang X ，Mei H ，Zheng Z ... -  《-》

Cross talk between RNA N6-methyladenosine methyltransferase-like 3 and miR-186 regulates hepatoblastoma progression through Wnt/β-catenin signalling pathway.

N6-methyladenosine (m6A) is a ubiquitous epigenetic RNA modification that plays a pivotal role in tumour development and metastasis. In this study, we aimed to investigate the expression profiling, clinical significance, biological function and the regulation of m6A-related genes in hepatoblastoma (HB). The mRNA and protein expression levels of m6A-related genes were analysed using Gene Expression Omnibus (GEO) and tissue microarray (TMA) cohort. Kaplan-Meier analysis was performed to evaluate the prognostic value of m6A-related genes in HB. Knockdown of m6A-related genes was conducted to analyse its function on cell proliferation, migration and invasion. Furthermore, bioinformatics analysis and experimental verification were used to explore the potential molecular mechanism and signalling pathway. We found that most m6A-related genes were significantly upregulated in HB tumour tissues. High levels of methyltransferase-like 3 (METTL3, P = .013), YTHDF2 (P = .037) and FTO (P = .032) indicated poor clinical outcomes, and the upregulation of METTL3 was an independent prognostic factor in HB patients. Functional assays showed that knockdown of METTL3 could dramatically suppress the proliferation, migration and invasion of HB cells. In addition, METTL3 was identified to be a direct target of microRNA-186 (miR-186). Consistently, miR-186 was low expressed in HB tumour tissues. Moreover, overexpression of miR-186 significantly inhibited cell aggressive phenotype both in vitro and in vivo, while the inhibitory effect could be reversed by METTL3 overexpression. Mechanism study indicated that miR-186/METTL3 axis contributed to the progression of HB via the Wnt/β-catenin signalling pathway. M6A-related genes were frequently dysregulated in HB. miR-186/METTL3/Wnt/β-catenin axis might serve as novel therapeutic targets and prognostic biomarkers in HB.

Cui X ，Wang Z ，Li J ，Zhu J ，Ren Z ，Zhang D ，Zhao W ，Fan Y ，Zhang D ，Sun R ... -  《-》

High expression of AlkB homolog 5 suppresses the progression of non-small cell lung cancer by facilitating ferroptosis through m6A demethylation of SLC7A11.

Non-small cell lung cancer (NSCLC) is a prevailing LC characterized by poor outcomes. AlkB homolog 5 (ALKBH5) functions as a tumor suppressor in several cancers. This study delved into the role of ALKBH5 in NSCLC development. TCGA database predicted ALKBH5 expression in NSCLC patients. ALKBH5 levels in NSCLC and human bronchial epithelial cells were determined. pcDNA3.1-ALKBH5/NC, pcDNA3.1-SLC7A11/NC, and ferrostatin-1 were used to explore the interactions among ALKBH5, SLC7A11, and ferroptosis. SLC7A11 mRNA and its protein levels were measured by RT-qPCR and Western blot. Cell viability, apoptosis, migration, and invasion were assessed by CCK-8, flow cytometry, and Transwell. Total N6-methyladenosine (m6A) quantification and its enrichment on SLC7A11 mRNA were determined, followed by the observation of Ki67, ALKBH5 and SLC7A11-positive cell numbers. Glutathione (GSH), lipid reactive oxygen species (lipid-ROS), malondialdehyde (MDA), and iron ion contents were determined. Animal experiments further analyzed the role of ALKBH5 in tumor development and glutathione peroxidase 4 (GPX4) expression. Bioinformatics analysis revealed the lowly-expressed ALKBH5 in LC patients. ALKBH5 was downregulated in NSCLC cells and its upregulation repressed proliferation activity, invasion, and migration, and facilitated apoptosis. ALKBH5 upregulation decreased GSH, increased lipid-ROS, MDA, and iron ion contents, and downregulated SLC7A11 by reducing m6A modification. SLC7A11 upregulation partly annulled the effect of ALKBH5 overexpression on cell ferroptosis and malignant behaviors. In vivo assays elucidated the suppression of ALKBH5 upregulation on tumor development and GPX4 levels. ALKBH5 upregulation downregulates SLC7A11 transcription by decreasing m6A modification, thus promoting NSCLC cell ferroptosis and ultimately repressing NSCLC progression.

Huang Z ，Lin G ，Hong Y ，Weng L ，Zhu K ，Zhuang W ... -  《-》