Fig. 1

Napabucasin inhibits GBM cell proliferation and STAT3 expression. a Correlation of STAT3 mRNA expression and the glioma grade in CGGA and TCGA databases. b Kaplan-Meier (KM) survival curves comparing glioma patients stratified by expression of STAT3. c Western blot analysis of STAT3 expression in four normal brain tissues (NBTs) and six GBM tissues. d Expression and localization of total STAT3 and p-STAT3 detected by immunofluorescence (IF) in normal human astrocytes (NHAs), U87MG and LN229 cells (scale bar: 50 μm). e Proliferation of glioma cells treated with Napabucasin and detected by CCK-8 assays. Half maximal inhibitory concentrations (IC₅₀) of Napabucasin in U87MG and LN229 cells were 6.4 and 5.6 μM respectively. f After treatment with the indicated doses of Napabucasin (0, 1, 5, and 10 μM) for 48 h, protein levels of STAT3 in U87MG and LN229 cells were evaluated by western blotting. g IF was used to estimate the expression of STAT3 in U87MG and LN229 cells after treatment with Napabucasin (scale bar: 50 μm). h EdU incorporation assays showed that exposure to 5 μM Napabucasin for 48 h impaired DNA synthesis in U87MG and LN229 cells. i Clonogenic assays were performed to examine the survival and proliferation of glioma cells treated with the vehicle or Napabucasin. (*p < 0.05, **p < 0.01, #p < 0.001)