Antitumor Activity In Vitro And The Mechanism Of Apoptosis Of H446Cells Induced By NS-7

NS-7was a compound isolated and purified from the fruit bodies of Suillus luteu, the relative molecular mass is440.29,name is3,6-dihydroxy-[(2E,6E,10E)-3,7,11,15-hexamethyl16carbon-2,6,10,14-tetraen] phenethyl ester, belonging to polyisoprene phenolic compounds, it is the isomers of suillin. Preliminary findings showed that the antioxidant and antitumor activity of NS-7were very effective. In this thesis, the NS-7in vitro antitumor activity and mechanism of inducing H446cells apoptosis were studied.Study on the proliferation inhibition of NS-7against human small cell lung cancer cell line H446, human chronic myelogenous leukemia cell line K562, human gastric cancer cell line BGC-823, human hepatoma cell line SMMC-7721, human breast cancer cell line MCF-7, human cervical carcinoma cell line Hela for48h by MTT-dye assay. The results showed that the six kinds of tumor cells proliferation inhibition were significantly enhanced with the NS-7concentration increasing. According to the IC50values from low to high in the following order: K562>H446>BGC-823> SMMC-7721> Hela> MCF-7, indicated K562and H446cells were most sensitive to NS-7. Compared with the commonly used chemical anti-cancer drug cisplatin, in addition to MCF-7cells, the effect of NS-7inhibited the proliferation of the remaining five kinds of tumor cells were similar, or even H446and K562cells superior to cisplatin, NS-7had the potential for development as new anti-cancer drugs.MTT assay results showed that the inhibition rate of H446cells with increasing concentration of NS-7and the processing time extension was increased significantly.H446cells treated with NS-7after Hoechst33258staining had the typical morphological features of apoptotic cells, karyopyknosis, gathered the nuclear internal edge showing the crescent-shaped, block, or ring, nuclear chromatin fragmented, formed apoptotic bodies then appeared secondary necrosis. And the features of apoptosis gradually increased with the increasing concentration of NS-7. The result of H446cells treated with NS-7staining Annexin V-FITC/PI by flow cytometry analysis showed the apoptotic rate was a significant dose-increase with the NS-7concentration increasing. H446cells treated with NS-7using flow cytometry and rhodanminel23staining to detect mitochondrial membrane potential changes, the result indicated the loss of mitochondrial membrane potential and drug concentrations were dose-effect relationship, the mitochondrial membrane potential was decreased with the NS-7concentration. Western blot analysis to detect the H446cells apoptosis related gene protein expression changes, the result of the increasing expression of cytochrome c and caspase-9indicated NS-7can induce H446cells apoptosis through the mitochondrial apoptosis pathway, the result of the increasing expression of FADD and caspase-8and the decreasing expression of NF-κB indicated NS-7can also induce H446cells apoptosis by death receptor pathway.In summary, NS-7has strong antitumor activity in vitro, and inhibited the proliferation of H446cells through the mitochondrial pathway and death receptor pathway interactions induce apoptosis.