Benzaldehyde Levofloxacin Schiff Base Induces Growth Arrest And Apoptosis Of Human Hepatocarcinoma SMMC-7721Cells

Objective: The compounds, which have significant inhibition to the growth of human liver cancer cell(SMMC-7721) line, were chosen by screening12kinds of fluoroquinolone derivatives. The preliminarystudies on the mechanism of the inhibition of the compound on the growth of human liver cancer cell(SMMC-7721) line were taken to provide the theoretical basis for the further development and utilizationof this kind of compounds.Methods: The inhibition of the fluoroquinolone derivatives to the cell growth was measured by theMTT cell proliferation assay; The morphological changes of SMMC-7721cell apoptosis were detected byHoechst33342staining; The rate of cell apoptosis was detected with TUNEL (terminal dexynucleotidyltransferase(TdT)-mediated dUTP nick end labeling) methods; Mitochondrial membrane potential (MMP,△ψm) was measured by high content screening image system; The changes of the related proteinexpression in the apoptosis signal pathway were detected with Western blotting. Western blotting was alsoused to detect the distribution of cytochrome C in the internal and external mitochondria.Results: The results show that the12kinds of compounds had inhibition effects on the proliferation ofthe human liver cancer cells (SMMC-7721). Among these compounds, the M15, M18, M19and M20hadsignificant inhibition on the cell proliferation. The M18is the abbreviation of (S)-1,8-(2-methylphosphate ethoxy)-6-fluorine-7-(4-methyl-piperazine-1-base)-3-[S-benzyl s-based-4-(fornitrobenzene methylene group amino)-1,2,4-all triazole-3-base]-quinoline (1-H)-4–ketone. In theconcentration of4~32μmol/L, M18significantly inhibited the proliferation of liver cancer cells, and this inhibition was concentration and time dependent. The IC50value of M18effects on was8.65μmol/L after24hours,5.43μmol/L after48hours and5.09μmol/L after72hours. The IC50value of levofloxacinhydrochloride effects on human liver cancer cell SMMC-7721was735.10μmol/L after24hours. The TheIC50value of M18effects on bone marrow mesenchymal stem cells was38.96μmol/L after24hours.Hoechst33258fluorescent staining was used to observe the morphological changes of the nucleus in theapoptosis cell. The results show that the apoptosis cells were significantly increased in the treatment group.The characteristic changes of apoptosis were observed such as the side accumulation of the cell nucleus,chromatin condensing of the cells and the cell nucleus cracking. The statistical analysis of the TUNELresults showed that the rate of cell apoptosis in treatment group was increased with the increase of M18concentrations in a dose dependant manner. There was a significant difference in comparison with thecontrol group (P <0.05). High content screening image system was used to measure the mitochondrialmembrane potential (MMP,△ψm). The results show that the mitochondrial membrane potential wasdecreased. The decrease of the mitochondrial membrane potential in the treatment group was statisticallydifferent with the control group. Western blotting results show that the protein expression of p53andCaspase-3higher than that in the control group. The expression of Caspase-3active fragment wasdramatically increased. In the mitochondria, the expression of cytochrome C was obviously reduced, butthe expression of cytochrome C in cytoplasm was significantly increased.Conclusions:1The modified fluoroquinolone derivative M18can significant inhibit proliferation ofthe tumor cell and has better selectively inhibiting effect on tumor cells. 2M18can induce human cancer liver cell SMMC-7721apoptosis. it is related to the mitochondrialapoptotic pathways through our research.