WTAP-mediated m6A modification of ARG2 mRNA Inhibits Its expression and drives prostate cancer malignant progression.

[BACKGROUND] Prostate cancer (PCa) incidence increases as age advances and seriously endangers men's health worldwide. Arginase 2 (ARG2) has been identified as a potential diagnostic and prognostic marker for PCa. However, the molecular mechanisms underlying its function in PCa remain undefined.

[METHODS] ARG2 mRNA and protein expression were quantified in PCa tissues and cells using qRT-PCR and Western blot. Cellular proliferation, glucose consumption, lactate production, apoptosis, and ferroptosis were evaluated via EdU incorporation, colony formation assays, commercial kits, and flow cytometry. Subsequently, the xenograft model was established to assess ARG2's role in tumor growth in vivo. Bioinformatics analysis and RNA immunoprecipitation (RIP) were employed to investigate the interaction between Wilms' tumor 1-associating protein (WTAP), a key component of the N6-methyladenosine (m6A) methyltransferase complex, and ARG2 mRNA. Besides, mRNA stability was determined using actinomycin D chase assays.

[RESULTS] ARG2 exhibited low expression in PCa tissues and cells. Upregulation of ARG2 inhibited proliferation and glycolysis, and promoted apoptosis, oxidative stress and ferroptosis of PCa cells. However, silencing ARG2 had the opposite effects. In vivo, ARG2 overexpression suppressed tumor growth. Mechanistically, WTAP bound directly to ARG2 mRNA, and their expression levels were inversely correlated. WTAP knockdown phenocopied ARG2 overexpression by repressing proliferation and glycolysis and enhancing apoptosis/ferroptosis, effects reversed by ARG2 silencing. ARG2 overexpression counteracted the oncogenic effects of WTAP overexpression.

[CONCLUSION] WTAP bound to ARG2 and suppressed its expression, thereby promoting the malignant progression of PCa.