Experimental Study Of Elemene On Methylation Of Tumor Suppressor Genes In Hepatocellular Carcinoma Cell Lines

Objective: To study the effect of elemene on the proliferation, apoptosis and cell cycle ofHepG2and QGY7703cells, To certain anti-tumor effect of elemene; To investigate thepromoter methylation status of GSTP1, RIZ1, SLIT2, HAI-2in elemene group and controlgroup of hepatocellular carcinoma cells, explore whether elemene can reverse thehypermethylation of silenced TSG; To select the methylation profile for the early clinicaldiagnosis of HCC.Method: MTT assay was used to determine the growth inhibition of HepG2and QGY7703cells. Flow cytometry was performed to analyze the cell cycle distribution and apoptosis ofHepG2and QGY7703cells. Methylation status of GSTP1, RIZ1, SLIT2, and HAI-2genespromoter were detected by Methylation Specific PCR (MSP) in elemene group and controlgroup of hepatic carcinoma cell Iines.Result: After elemene was added to HepG2and QGY7703for48h, elemene could inhibitthe proliferation, difference between the groups was statistically significant (P<0.05), IC50for both HepG2and QGY7703were (69±6.3) μg/ml and (63±2.1) μg/ml; Naturalapoptosis of HepG2and QGY7703were (6.37±0.15) μg/ml and (7.40±0.66) μg/mlwithout treatment of elemene, the10，20,30μg/ml different concentration of elemenecould induce apoptosis, the apoptosis ratios were (20.83±0.25) μg/ml and(12.50±0.61)μg/ml,(27.7±0.75) μg/ml and (32.77±2.30) μg/ml,(37.1±0.46) μg/ml and (48.27±1.23)μg/ml，difference between the groups was statistically significant (P<0.05); The10，20,30μg/ml different concentrations of elemene make two HepG2and QGY7703arrest in Sphase, the percentage of cells in G1phase of two cells decreased from (68.71±0.69)%and(65.56±0.41)%to (60.81±0.38)%and (53.00±0.15)%, the percentage of S phase cells oftwo cells increased from (28.85±0.18)%and (27.04±0.45)%to (36.81±0.36)%and(38.43±0.60)%, difference between the groups was statistically significant (P<0.05); GSTP1, RIZ1and HAI-2methylation were detected in all cell lines, SLIT2wassemi-methylation status in the two cell lines, after which the40μg/ml and160μg/mlconcentration of elemene and5-Aza-dc treatment, GSTP1gene appeared unmethylatedstatus in QGY7703cells.Conclusion:1.Elemene can inhibit the proliferation, induce apoptosis of the HepG2and QGY7703cells, arrest cells entering G2/M phase from S phase, the effect was in a dose-dependentmanner.2.Elemene can reverse the status of gene promoter methylation, but with gene andcell-specific.3. The methylation status of GSTP1, RIZ1and HAI-2promoter were specific to HCC, theycan make good differentiation between HCC and non-cancerous tissues.