Fig. 6

A regulatory feedback loop exists between ZDHHC15 and IL-6/STAT3 signaling. a Putative binding motif of transcription factor STAT3 for ZDHHC15 isoforms 1, 2, and 3 was predicted from the JASPAR database. The top three STAT3 binding sites (labeled E1′, E2, and E3) for ZDHHC15 isoforms 1 and 3 and four binding sites (labeled E1′, E2′, E3′, and E4′) were chosen for further analysis. b qRT-PCR was performed to evaluate the activity of STAT3 ZDHHC15 transcription in U251 GSCs transfected with STAT3 siRNA or treated with STAT3 inhibitor STAT3-IN-7 (5 μM) or rhIL-6 (5 ng/mL), alone or in combination. c Luciferase reporter assay demonstrated luciferase activities of ZDHHC15 isoform reporters in U251 GSCs transfected with STAT3 siRNA or treated with STAT3 inhibitor STAT3-IN-7 (5 μM), or the local anesthetics prilocaine, lidocaine, procaine, and ropivacaine (20 μM each). d Luciferase reporter assay demonstrated luciferase activities of various truncated reporters in U251 GSCs, determining the region of ZDHHC15 isoform promoters on which STAT3 could bind to mediate transcriptional activation. e ChIP assay was performed using the p-STAT3 antibody to demonstrate the enrichment of the STAT3-binding region of the promoter of ZDHHC15 isoforms in U251 GSCs. f Tumor growth of U251 GSCs transfected with ZDHHC5 shRNA or pretreated with prilocaine, lidocaine, procaine, and ropivacaine (20 μM). g Tumor weights were measured after 6 weeks (n = 5 mice/group)