Study On PHI Inhibition Of Gene P15 Hypermethylation In Molt-4 Cell

Objects To investigate the effect of Phenylhexyle Isothiocyanate (PHI) on demethylation and activation transcription of p15 in acute leukemia cell line Molt-4, which has been proved a novel HDACi recently,and to further study its potential mechanism of demethylation.Methods DNA sequencing and Modified Methylation Specific PCR (MSP) were used to screen p15-M and p15-U mRNA after Molt-4 cells had been treated with PHI, 5-Aza and TSA. DNA methyltransferase 1(DNMT1), 3A (DNMT3A), 3B (DNMT3B) and p15 mRNA were measured by RT-PCR. P15 protein was detected by Western Blotting.Results The gene p15 in Molt-4 was hypermethylated and gene silence. Hypermethylation of gene p15 was apparently attenuated and p15 gene was de novo activation after 5days exposure to PHI in a concentration dependent manner. DNMT1 and DNMT3B were inhibited by exposure to PHI for 5 days (P<0.05). Alteration of DNMT3A was not significant at those concentrations.Conclusions We have demonstrated that PHI could active demethylation and activation transcription. Hypermethylation of gene p15 was reversed and activation transcription could be de novo by PHI in Molt-4. It may result from down-regulating DNA methyltransferases, DNMT1 and DNMT3B, or up-regulating the histone acetylation that allow chromatin to unfold and the accessibility of regulators in the p15 promoter for transcription activation.