[Phenylhexyl isothiocyanate reducing U266 cell line methylation level of p16 gene].

This study was purposed to investigate whether phenylhexyl isothiocyanate (PHI) can reduce p16 gene methylation level or not. The myeloma U226 cell line was cultured with PHI of 0, 5, 10 micromol/L for 72 hours, then DNA was extracted. Hydrosulfite was used to treat the genome DNA of healthy adult, PCR amplification was carried out by using this DNA as template. The gene chip detecting methylation changes of 3 CpG in promoter region of p16 gene was constructed by designing a pair of probes which contain one methylated and one unmethylated probes. This pair of probes was used to detect 3 consecutive sites of CpG island in p16 gene. The standard curve was constructed by using gene chip after the methylated and unmethylated DNA were mixed at different ratio. Then treated samples of U266 cells were dotted on gene chip, obtained results were compared with standard curve to get the quantitative results. The results indicated that the probes on chip had excellent reproducible ability and precision, the methylation level of p16 gene in U266 cells treated with 0, 5 and 10 micromol/L of PHI was determined as 78.2%, 61.7% and 54.8%, respectively. It is concluded that the PHI can reduce the methylation level of p16 gene in U266 cells.

[Advance of study on demethylation in leukemia - review].

DNA methylation is a frequent change in epigenetics of leukemia. In the development of leukemia, methylation plays an important role in the genetic expression regulation and genetic structure stabilization. Hematopoietic stem cell transplantation (HSCT) and chemotherapy are the common methods to cure leukemia at present. Unfortunately, it is very hard to find suitable donor for transplantation, while the relapse and drug resistance are the unresolved problems in chemotherapy. Because of the reversibility of methylation, the drugs reducing the level of methylation become a new way to cure leukemia. Decitabine is the most common medicament used to reduce the level of methylation. In this article, the methylation and tumor, methylation and hematologic diseases, methylation detection methods, demethylation therapy in leukemia and so on are reviewed.