Fig. 7

Targeting ADAR1 in growing tumor mass blocks glioblastoma progression. a Quantitative analysis of tumor size (tumor volume) of U87MG cells subcutaneously injected into the flank of NOD-SCID mice (n = 16 mice). Tumors generated by control (n = 8) or shADAR1 (n = 8) inducible U87MG cells were treated with DOXY (in drinking water). Tissues were collected and analyzed at the end of treatment (60 days p.i.). *p ≤ 0.05. Right, a representative picture of tumors. Representative sections and relative quantification of Ki67 (b), ADAR1 (c), and CDK2 (d) staining are shown. e qRT-PCR of CDK2 using mRNA obtained from the same samples. Data were normalized to the mean of controls values set to 1. *p ≤ 0.05, **p ≤ 0.01. f Schematic representation of METTL3/ADAR1 modulation in glioblastoma. METTL3/METTL14 methylates ADAR1 mRNA allowing the reader YTHDF1 to boost ADAR1 translation. The high level of ADAR1 protein (with unaltered ADAR1 mRNA) correlates with GBM patient OS and promotes cell proliferation by stabilizing CDK2. Moreover, the ablation of ADAR1 in an METTL3 unaltered background is sufficient to inhibit glioblastoma in vivo