Fig. 4

Elevated PLK2 promotes chemosensitivity in GBM. a, Concentration survival curve of U87 and U251 TMZ-resistant cell lines and non-treated cell lines (P < 0.01, with one-way ANOVA followed by Dunnett’s post-test). b, qRT-PCR analysis for measuring the mRNA expression of PLK2 in glioma TMZ-resistant cell lines versus non-treated cell lines. c, Western blot assays to compare the PLK2 protein expression in TMZ resistant glioma cell lines with non-treated cell lines. β-actin was used as an internal control. d, qRT-PCR assays to measure the mRNA expression level of PLK2 in TMZ resistant cell lines when transduced with lentiviral PLK2 and negative control (**P < 0.01, with student’s t-test). e, Western blot analysis to detect the overexpression efficiency of lentiviral PLK2 in U87 resistant cell liens. β-actin was used as an internal control. f, In vitro cell proliferation assays were performed by using different interventions as indicated in U87 cell line. (**P < .01, with one-way ANOVA followed by Dunnett’s post-test). g, Upper panel: Flow cytometry analyses using Annexin V and Propidium Iodide for apoptotic ratio analysis in U87 resistant cells pretreated with indicated interventions. Lower panel: Representative images of H&E-stained mouse brain sections after the intracranial transplantation with indicated U87 cell lines. h, Kaplan-Meier analysis for in vivo intracranial xenograft mice using U87 cells pre-transduced with PLK2 lentivirus and negative control (P = 0.0026, with log-rank test). All data were presented as the mean ± SD of triplicate independent experiments