(A) Immunoblot of OPTN expression after METTL3 knockdown in 1919 and GSC20 treatment with or without PDGF. (B) Immunoblot of GSCs after transduction with shMETTL3.915, shMETTL3.1040, or shCONT with or without PDGFRΒ overexpression. (C) Immunoblot of METTL3 WT or D395A rescue in GSCs with or without PDGFRΒ knockdown. (D) Immunoblot of OPTN expression in METTL3 knockdown GSCs with or without OPTN knockdown. (E) Cell viability of 1919 (left) and GSC20 (right) cells with METTL3 and OPTN knockdown, up to 3 days of post-infection. Error bars show standard deviation. **, p < 0.01. (F) Immunoblot of OPTN expression in PDGFRΒ knockdown GSCs with or without OPTN knockdown. (G) Cell viability of 1919 (left) and GSC20 (right) cells with PDGFRΒ and OPTN knockdown, up to 3 days of post-infection. Error bars show standard deviation. **, p < 0.01. (H) Kaplan-Meier survival curves of immunocompromised mice bearing intracranial 1919 GSC transduced with METTL3 and OPTN knockdown (above). Log-rank test was used for statistical analysis. shMETTL3 vs. shMETTL3/shOPTN (p = 0.0018). shOPTN vs. shMETTL3/shOPTN (p = 0.0018). Representative images of hematoxylin and eosin-stained sections of tumor-bearing brains (below). Brains were harvested after the presentation of first neurological sign in any cohort. Scale bar, 1 mm. (I) Kaplan-Meier survival curves of immunocompromised mice bearing intracranial 1919 GSC transduced with PDGFRΒ and OPTN knockdown (above). Log-rank test was used for statistical analysis. shMETTL3 vs. shMETTL3/shOPTN (p = 0.0044). shOPTN vs. shMETTL3/shOPTN (p = 0.0198). Representative images of hematoxylin and eosin-stained sections of tumor-bearing brains (below). Tumors were derived from 1919 cells transduced with PDGFRΒ and OPTN knockdown. Brains were harvested after the presentation of first neurological sign in any cohort. Scale bar, 1 mm. (J) Kaplan-Meier curve showing patient survival based on PDGFRβ, METTL3 and OPTN mRNA expression in glioma patients from the TCGA dataset. Log-rank test was used for statistical analysis. (K and L) In vitro viability assay of 1919 (K) and MES20 (L) treated with indicated concentrations of UZH1, Crenolanib, and AICAR. (M and N) Synergy score analysis of 1919 (M) and MES20 (N) treated with UZH1 and crenolanib or AICAR. (O) Luciferase image of tumors from respective experimental groups. (P) Kaplan-Meier survival curves of tumor bearing mice from orthotopic intracranial xenograft implantation of 1919, treated with PBS, crenolanib, UZH1, AICAR, or their combined treatment. Log-rank test was used for statistical analysis. (**, p = 0.0018, UZH1 vs. vehicle, AICAR vs. vehicle, UZH1 vs. UZH1+AICRA, AICAR vs. UZH1+AICAR.)