Huan-li XU,Qun-ying CHEN,Hong WANG,Ping-xiang XU,Ru YUAN,Xiao-rong LI,Lu BAI,Ming XUE(Department of Pharmacology,School of Basic Medical Sciences,Capital Medical University,Beijing 100069,China)

T2-29

Inhibitory effects of lapachol on rat C6 glioma in vitro and in vivo by targeting DNA topoisomeraseⅠ and topoisomeraseⅡ

Huan-li XU,Qun-ying CHEN,Hong WANG,Ping-xiang XU,Ru YUAN,Xiao-rong LI,Lu BAI,Ming XUE(Department of Pharmacology,School of Basic Medical Sciences,Capital Medical University,Beijing 100069,China)

OBJECTIVELapachol is a natural naphthoquinone compound that possesses extensive biological activities.The aim of this study is to investigate the inhibitory effects of lapachol on rat C6 glioma both in vitro and in vivo,as well as the potential mechanisms.METHODSThe antitumor effect of lapachol was firstly evaluated in the C6 glioma model in Wistar rats.The effects of lapachol on C6 cell proliferation,apoptosis and DNA damage were detected by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium(MTS)/phenazinemethosulfate(PMS)assay,hoechst 33358 staining,annexinⅤ-FITC/PI staining,and comet assay.Effects of lapachol on topoisomerase I(TOP I)and topoi?someraseⅡ(TOPⅡ)activities were detected by TOPⅠ and TOPⅡ mediated supercoiled pBR322 DNA relaxation assays and molecular docking.TOPⅠ and TOPⅡ expression levels in C6 cells were also determined.RESULTSHigh dose lapachol showed significant inhibitory effect on the C6 glioma in Wistar rats(P＜0.05).It was showed that lapachol could inhibit proliferation,induce apoptosis and DNA damage of C6 cells in dose dependent manners.Lapachol could inhibit the activities of both TOPⅠandⅡ.Lapachol-TOPⅠ showed relatively stronger interaction than that of lapachol-TOPⅡ in molecular docking study.Also,lapachol could inhibit TOPⅡ expression levels,but not TOPⅠ expression levels.CONCLUSIONThese results showed that lapachol could significantly inhibit C6 glioma both in vivo and in vitro,which might be related with inhibiting TOPⅠand TOPⅡactivities,as well as TOPⅡexpression.

lapachol；C6 glioma；topoisomeraseⅠ；topoisomeraseⅡ