Effect Of Casticin On The Expression Of RASSF1A In Hepatocarcinoma Cells

Objective: To observe the effect of casticin(CAS) on RESSF1 A gene expression and Sp1 activation in liver hepatocarcinoma HepG2 cells.Methods: Hepatocarcinoma cell line HepG2 was cultured in vitro and divided into control group and different concentrations of CAS groups. For the control group, cells were treated by the same volume of medium;For the CAS groups, cells were treated by 0.5,1.0,2.0μmol/L CAS for 0~48h.The methylation of the promoter in RASSF1 A was detected by Methylation-Specific PCR(MSP). The total mRNA and proteins were extracted, and expression of RASSF1 A and DNA methyltransferase 1(DNMT1) were detected by real time PCR and Western blot, respectively.Results:1.MSP results showed that the expression level of methylated RASSF1 A was expressed in untreated cells. When cells were treated with CAS for 0 ~ 48 h, the Methylated DNA was decreased as the concentration of CAS was increased. On the contrary, the un-methylated RASSF1 A was increased correspondingly.2.The mRNA of RASSF1 A level was very low in HepG2 cells. After treatment of different concentration of CAS for 0~48h, the RASSF1 A mRNA increased gradually, as demonstrated by real-time PCR. Similar results was observed for RASSF1 A protein, as shown by Western blot.3.The DNMT1 mRNA was very high in un-treated cells. As the concentration of CAS increased, the DNMT1 mRNA decreased gradually, similar results was obtained by Western blot.Conclusion: CAS could decrease the methylation of RASSF1 A and increase its expression in HepG2 cells;CAS treatment could decrease the DNMT1 level in HepG2 cells.