Fig. 2.

circ-MAPK4 behaved as an oncogene in glioma cells. (a) Circ-MAPK4 is also highly expressed in glioma cell lines, especially in U138 and U373, when compared to gial cell line (HA1800). (b) Schematic representation of target sequences of siRNAs which specially silence circ-MAPK4. (c) The silence efficiency of siRNA targeting to circMAPK4 was analyzed by qPCR after transfected for 48 h in either U138 or U373 cells. (d) CCK-8 assays were performed to test survival of U138 and U373 cells after silencing of circ-MAPK4. (e) Colony formation assays were performed to test survival of U138 and U373 cells after silencing of circ-MAPK4. (f) Apoptosis assays were used to detect apoptosis levels of circ-MAPK4 silenced U138 and U373 cells. (g) Western blot assays were performed to analyze the protein expression levels of cleaved form of caspase-9, caspase-7, caspase-3, and PARP1 in circ-MAPK4 silenced U138 and U373 cells. (h) Transwell assays were carried out to test the invasive activity of circ-MAPK4 silenced U138 and U373 cells. The results above were summarized as bar graph. All data are the means ± SEM of three experiments. *P < 0.05; **P < 0.01; ***P < 0.001