OBJECTIVETo observe the effect of SSd on reversing the malignant phenotype of HepG2 cells and to investigate its mechanism in order to prove that SSd is a new choice to prevent and treat HCC.

METHODSHepG2 cells were cultured and treated by different concentration (0 mg/L, 2.5 mg/L, 5.0 mg/L, 10.0 mg/L and 20.0 mg/L) of SSd for 24 h, and treated by 10 mg/L of SSd for 0 h, 6 h, 12 h, 24 h, 48 h and 72h respectively. The cell inhibition rates were measured by MTT assay. Then cells were treated by 10 mg/L SSd for 48 hr in experimental group and treated by no SSd as a control, their morphological changes were observed by contrast phase microscope. The concentrations of ALB and AFP in clear supernatant liquid of cells were detected by radio-immunity and chemiluminescence. The cell migration rates were observed by transwell method, the relative expression levels of p27 mRNA were measured by RT-PCR.

RESULTSThe inhibitive effect of 10 mg/L SSd was the most significant among different concentrations ( F = 265.06, P less than 0.01). The shape of HepG2 from experimental group turned into small and round, and their volume ratios of nucleus to plasma decreased. ALB in supernatant liquid of HepG2 was higher ( t = 7.83, P less than 0.05, and its AFP was lower ( t = -10.72, P less than 0.01) as compared to control group. Cells migrated were fewer and p27 mRNA expression of HepG2 was higher in experimental group than that in control group (t = 22.00, P less than 0.05).

CONCLUSIONSSd could reverse the malignant phenotype of HepG2 cells. It was suggested that the up-regulation of p27 mRNA expression play an important role in the differentiation of HepG2 cells treated by SSd.