[Comparison of the effect between procaine and 5-aza-dc on wnt inhibitory factor 1 promoter methylation of HepG2].

Objective: To observe the CpG island methylation status, mRNA and protein expression of the Wnt inhibitory factor-1 (Wif-1) gene with procaine or 5'-Aza-2'-deoxycycytidine (5-aza-dc) on HepG2. And to explore the comparison of the demethylation with 5-aza-dc or procaine.

Methods: HepG2 cells were treated with 5-aza-dc or procaine. Wif-1 mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR). Wif-1 protein expression was detected by Western blot. The promoter methylation status of Wif-1 gene on treatment or not were detected by methylation-specific PCR (MSP).

Results: (1) RT-PCR and Western blot exhibited that both Wif-1 mRNA and Wif-1 protein expression were positive in groups treated with procaine and 5-aza-dc and highly positive in the L0 cells group, but weakly even negative in the HepG2 cells without any treatment, the difference were statistically significant (P < 0.05) (procaine experimental group was higher than that of 5-aza-dc experimental group, P < 0.05). (2) The positive rates of the promoter hypermethylated in procaine and 5-aza-de groups were (14.41 +/- 3.37)% and (29.29 +/- 1.84)%. Both of the two groups showed a part of the de-methylation status (P < 0.05).

Conclusion: Both of procaine and 5-aza-dc can reverse the abnormal methylation of Wif-1 gene. Procaine can be more effective than conventional used 5-aza-dc and could be a new demethylation drug.