The Mechanism Of 2-dodecylsulfinyl-1,4-naphthoquinone Induced Apoptosis In Gastric Cancer Cells

Gastric cancer is a malignant tumor with high Morbidity.Every year,more than 300,000 people die from stomach cancer,which seriously threatens human health and life.So it is extremely urgent to find an anti-tumor drug with an effective,inexpensive and less toxic side-effect.Naphthoquinones are a class of organic compounds which were widely found in nature.Because of their good anti-tumor activitys,they have attracted the attention of domestic and foreign researchers.However,due to their strong side-effects,their clinical application has been severely limited.In order to improve the antitumor activity of 1,4-naphthoquinone derivatives and reduce their toxic and side effects on normal cells,we designed and synthesized a novel 1,4-naphthoquinone derivative 2-dodecylsulfinyl-1,4-naphthoquinone(DSNQ).In this study,we used a variety of gastric cancer cells,and elucidated the cytotoxic effect,apoptotic effect and related siginaling pathway of DSNQ on gastric cancer cells and explored their potential molecular mechanisms.According to this study,we will provide a reliable basis for clinical research and cancer treatment.In this study,we used Michael addition reaction and MCPBA oxidation reaction to synthesize a novel 1,4-naphthoquinone derivatives,2-dodecylsulfinyl-1,4-naphthoquinone(DSNQ).The structure of synthetic compounds was identified by nuclear magnetic resonance(NMR)technique.The effects of DNSQ on 12 kinds of gastric cancer cells were detected by using MTT assay and WST-1 assay.The apoptotic effect of DSNQ on gastric cancer cells was detected by Annexin V-FITC/PI double staining,Hochest staining and flow cytometry.The expression levels of downstream apoptotic related protein were detected by western blotting in human gastric cancer cells.The regulation effects of DSNQ on intracellular upstream protein p38,JNK,ERK and STAT3 were detected by the western blotting.The interaction between the MAPKs signaling pathway and the STAT3 signaling pathway was detected by western blotting after treatment DSNQ in human gastric cancer cells.The regulation effect of DSNQ on intracellular reactive oxygen species levels were detected by flow cytometry and western blotting.The result of NMR technology showed that both hydrogen atoms at 3,5,6,7 and 8 positions,and alkane bonded to the fluorenyl group exhibited specific chemical shifts.The carbon spectrum shows the corresponding chemical shift of 22 carbon atoms.Mass spectra show the corresponding molecular weight;DSNQ had inhibitory effect on the viabilities of 12 gastric cancer cells with a dose dependence and had significant difference in comparison with the positive control drug 5-FU.At the same time,the cytotoxicity of DSNQ to three human normal cells were lower than that of positive control drug;DSNQ induced the apoptosis of AGS cells through increasing apoptotic protein Bad,cle-caspase-3 and cle-PARP,decreasing the expression level of anti-apoptotic protein Bcl-2 in gastric cancer AGS cells;DSNQ could promote the expression of p-p38 and p-JNK,and inhibit the expression of p-ERK and p-STAT3 protein in gastric cancer AGS cells;DSNQ could induce cell apoptosis through increasing the generation levels of reactive oxygen species in human gastric cancer AGS cells.2-dodecylsulfinyl-1,4-naphthoquinone(DSNQ)has a good killing effect on 12 kinds of gastric cancer cells,and the potential mechanism of killing effect may be that DSNQ regulates MAPK/STAT3 signaling pathways by increasing the generation levels of intracellular reactive oxygen species,activating the caspase cascade and eventually induces mitochondrial-dependent apoptosis in gastric cancer cells.It provides experimental data and theoretical basis for clinical treatment of gastric cancer and development of new drugs.