Synthesis Of Tanshinone ?A Derivate Targeting G-quadruplex And Its Mechanism Of Anti-hepatocellular Carcinoma

Hepatocellular carcinoma(HCC),one of the most common cancer,is the fourth cause of cancer-related death and rank sixth in terms of incident cases.In present,the treatment of HCC is short of specific therapy and most of antitumor agents showed great side effect and drug resistance.Therefore,it needs to find effective target drugs on treatment of HCC.Tanshinone ?A is an effective component extracted from Salvia miltiorrhiza and exhibits great antitumor activity.In order to improve bioavailability of Tanshinone ?A,a series of Tanshinone ?A derivates were synthesized by structural modification and screened for antitumor activity.Among these derivates,TA06 showed great inhibitory effect on HCC and low cytotoxicity to normal cells.In this study,we investigated antitumor effects and its mechanism of TA06.In this study,Tanshinone ?A derivate TA06 was synthesized and showed great antitumor activity and low cytotoxicity detected by MTT assay.Molecular docking confirmed that TA06 had a strong interaction with VEGF G-quadruplex.We further applied BG4 immunofluorescence,UV spectrum titration and ELISA assay to prove that TA06 could stabilize G-quadruplexes,thus leading to chromosome damage and inhibiting tumor VEGF secretion.Then,we used H&E staining,flow cytometry,comet assay and immunofluorescence of ?-H2 AX to prove that TA06 could cause DNA double-strand breaks(DSBs)and induce apoptosis to inhibit tumor growth.Immunofluorescence of VEGFR2,pVEGFR2 and paxillin on Hep G2 cells showed that TA06 could inhibit cells migration.Moreover,TA06 repressed tumor angiogenesis proved by zebrafish tumor model.Furthermore,VEGF-induced angiogenesis in zebrafish,and immunofluorescences of VEGFR2 and pVEGFR2 were examined on tumor zebrafish and the results showed that TA06 could attenuate the secretion of VEGF,thereby reducing the binding of VEGF to VEGFR2.The phosphorylation of VEGFR2 was reduced,which weakened the activation of the downstream signal pathway,and finally tumor angiogenesis was inhibited.In general,TA06,a Tanshinone ?A derivate,was synthesized and showed anti-hepatocellular carcinoma.TA06 might cause DNA doublestand breaks(DSBs),induce cell apoptosis and inhibit proliferation of Hep G2 cells through binding and stabilizing G-quadruplex.Besides,TA06 could reduce transcription of VEGF,attenuate the phosphorylation of VEGFR2 by binding and stabilizing G-quadruplex to inhibit tumor cell migration and angiogenesis.Therefore,TA06 can be a candidate drug for anti-hepatocellular carcinoma via targeting G-quadruplex.