Proteomic Analysis Of Human Gastric Cancer Cell Line HGC-27 In Response To Curcumin

Objective:To investigate the effects of curcumin on proliferation, apoptosis and protein expression of human gastric cancer cell line HGC-27 and its anti-tumor mechanism.Methods:Methyl thiazolyl tetrazolium reduction assay was used to detect the cell proliferation activity of HGC-27 cell line treated with 0,10,20,30,40μmol/L curcumin and treated for 24,48,72 hours,Transwell assay was applied to detect the inhibitory effect of curcumin on invasiveness of human gastric cancer cell line HGC-27,Flow cytometry was used to observe inhibitory effects of cell cycle and apoptosis rate on HGC-27 treated with 20μmol/L curcumin for 24,48,72h,Electron microscope was applied to view morphology of human gastric cancer cell HGC-27 cells after treated with 20μmol/L curcumin.Two-dimensional electrophoresis(2-DE)and Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)were used to identify differential protein of human gastric cancer cell HGC-27 cell treated by curcumin.Results:1.Methyl thiazolyl tetraz01ium reduction assay showed that curcumin can inhibit the proliferation of HGC-27 cell line significantly, the growth inhibition rate was 24.65%and 32.42%treated with 20μmol/L and 30μmol/L curcumin for 72 hours,while with 40μmol/L curcumin to treat it the inhibition rate reached to high as 76.43%,and depending on dosage obviously,and inhibition rate was different with the same dosage treated for different time,the longer time treated,the higher inhibition rate was,also with time dependence.To compare the groups with different dosage and different treating-time each other,The difference was significant(P＜0.05). 2.The result of Transwell assay showed that invasiveness of HGC-27 cell line was obviously inhibited by curcumin in dose-and timedependent manner,to compare them with control group,the difference was significantly(P＜0.05)3.The result of flow cytometry displayed that the apoptosis rate was 12.19±0.31%,15.73±0.33%,21.37±1.14%treated with 20μmol/ Lcurcumin for 24,48,72 hours respectively,but for control group apoptosis rate was 1.35±0.22%,3.76±0.37%,4.13±1.63%respectively. To compare two groups,the difference is very significant(P＜0.05).cell proportion of each stage in cell cycle was 54.6±2.16%,55.2±3.64%, 54.1±1.65%of G₀/G₁,33.7±2.34%,37.7±2.31%,42.2±3.71%of S stage and 12.6±2.61%,7.5±3.11%,3.8±2.55%of G₂/M stage respectively treated with 20μmol/L curcumin for 24,48,72 hours.For control group, cell proportion of each stage in cell cycle was 62.8±2.51%,65.3±3.69%, 64.6±3.51%of G₀/G₁ stage,21.3±4.31%,17.6±3.25%,18.3±3.15%of S stage,18.6±3.71%,16.3±2.19%,17.2±1.20%of G₂/M stage.To compare two groups of each stage,the difference was significant(P＜0.05),The cell proportion of HGC-27 cells in S stage was increased significantly treated by curcumin,while cell proportion of HGC-27 cells in G2/M decreased relatively.4.The protein spots of 2-DE maps in the curcumin treated and control group HCG-27 cells were 1245±37 and 1208±29 which separated by two-dimensional gel electrophoresis,26 differential proteins were identified with image analysis system,14 non-redundant differential proteins were verified by matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF-MS),among them,some proteins involved in cellular metabolism,oxidative stress,cell cycle progress and signal transduction. Conclusion:1.Curcumin can significantly inhibit the proliferation and invasiveness of gastric cancer cell line HGC-27.Induce HGC-27 cell apoptosis.2.2-DE patterns of curcumin-treated and control HGC-27 cells were established.14 differential proteins were identified.The protein spectra of HGC-27 cell can be changed by curcumin.It will provide new clue for elucidating the mechanism of curcumin anti-gastric cancer.