Inhibitory Effects of Decoy-ODN Targeting Activated STAT3 on Human Glioma Growth In Vivo

Background: It has been previously found that a constitutively activated signal transducer and activator of transcription 3 (STAT3) blocked by decoy-ODN led to glioma growth inhibition in vitro. The objectives of this study were to identify whether STAT3 decoy-ODN had the same effect or not in vivo. Materials and Methods: Western blot was used to detect p-STAT3 in glioma and normal brain tissue. U251 cells were subcutaneously injected into nude mice and decoy-ODN was intratumorally administrated. TUNEL was used to exam the apoptosis cells in xenografts. Genes regulated by STAT3 were evaluated by RT-PCR and immunohistochemistry. Results: Activated STAT3 was highly present in glioma but not normal brain tissues. STAT3 decoy-ODN could significantly suppress the growth of glioma by inhibiting proliferation and promoting apoptosis in xenografts. The target genes controlled by STAT3 were down-regulated at both transcription and translation levels. Conclusion: The present study suggested that decoy-ODN provide an effective therapeutic approach to treat glioma in vivo.