Fig. 4: ULK1 R170me2s promotes mitochondria turnover and tumor growth under hypoxia.

c–e Data was normalized to the WT untreated group. a, b Indicated cells were incubated under 1% oxygen for 12 h. Immunofluorescent staining was performed. The boxed areas (Scale bar, 10 µm) were enlarged (Scale bar, 4 µm) (a). Ultrastructure was analyzed. Vacuoles (Scale bar, 1.5 µm) labeled with asterisk were enlarged (Scale bar, 500 nm) (b). Data represent the mean ± SD from three independent experiments. P-value is from the two-sided t-test. c Indicated cells were incubated under 1% oxygen for 24 h. The level of mitochondrial DNA (mtDNA) was measured. Data represent the mean ± SD from three independent experiments. P-value is from the two-sided t-test. d Indicated cells were stimulated with 1% oxygen for 18 h, and the cellular OCR was measured immediately in normoxia condition. Data represent the mean ± SD from three independent experiments. P-value is from the two-sided t-test. e, f Indicated cells were incubated under 1% oxygen for 48 h. BrdU incorporation assay (e) and Trypan blue exclusion assay (f) were performed. Data represent the mean ± SD from three independent experiments. P-values are from the two-sided t-tests. g Mice (n = 8) were intracranially injected with indicated LN229 cells, and were maintained in ambient atmosphere or 11% oxygen tension before sacrificed for examination of tumor growth (left panel). Representative H&E-stained coronal brain sections are shown (right panel). Data represent the mean ± SD. P-values are from the two-sided t-tests. Bonferroni correction was used for multiple hypothesis correction. h Immunochemical staining of mice tumors. Scale bar, 75 µm. i Immunochemical staining of human GBM tissues. Scale bar, 100 µm. N, necrotic region. j Quantification of the immunochemical staining of human GBM samples (n = 40). k Kaplan–Meier plots of the overall survival time of patients (n = 60) with distinct ULK1 R170me2s levels. P-value is from the two-sided log-rank test. l Model of dynamic ULK1 methylation and autophagy induction under hypoxia. Source data are provided as a Source data file.