Fig. 4.

SPI1 binds to the promoter regions of PAICS and regulates PAICS expression. a Schematic of the PAICS promoter luciferase construct is depicted with the locations of the GGGAAG element and the sequences of mutation. Relative luciferase activities of the Wt or Mut GGGAAG regions in U87 and U251 cells were examined after transfecting with SPI1 48 hour later. The values of PGL3-WT and PGL3-Mut were relative to PGL3-basic. Data are mean ± SD for triplicate samples. ***, p < 0.001. b SPI1 binding at the promoter region of PAICS containing the GGGAAG element was assessed by CHIP assay. c PAICS RNA levels after transfecting the SPI1 interference fragment into the U87 and U251 cells. PAICS expression was normalized to GAPDH. Error bars indicate mean ±SD of 3 independent experiments. *, p < 0.05; ** p < 0.01; ***, p < 0.001