[Methylation status of JunB and CDH13 gene promoter in CD34(+)CD38(-) chronic myelogenous leukemia cells]

Chronic myelogenous leukemia (CML) is a clonal myeloproliferative disease of transformed hematopoietic progenitor cells. The expressions of JunB and CDH13 (cadherin-13) gene as tumor suppressor gene were inactivated by promoter methylation in CML patients. This study was purposed to investigate the methylation difference of JunB and CDH13 gene promoter and the expression levels of JunB and CDH13 gene in CD34(+)CD38(-) cells in CML patients vs normal individuals. CD34(+)CD38(-) cells from 8 cases of CML and 5 normal individuals were selected by flow cytometry. The methylation status of JunB and CDH13 genes were detected by MS-PCR in selected CD34(+)CD38(-) cells. The expression levels of JunB and CDH13 gene was detected with real time polymerase chain reaction (RT-PCR). The results showed that no methylation of JunB and CDH13 gene was detected in CD34(+)CD38(-) cells of 5 normal individuals. Methylations of JunB and CDH13 promoter were found in 87.5% (7/8) and 50% (4/8) CML CD34(+)CD38(-) cells, percentages of which were significantly higher than those in normal individuals. The difference was statistically significant (p < 0.05). The relative expression levels of JunB and CDH13 mRNA in CD34(+)CD38(-) cells of CML patients were significantly lower than those in normal individuals (2(-DeltaDeltaCT) were 1/5.21 and 1/10.63 respectively). It is concluded that the high methylation of JunB and CDH13 gene promoter occurs in CD34(+)CD38(-) cells of CML patients, their mRNA expression level is significantly lower, thus the methylation of JunB and CDH13 gene promoter probably plays a role in the pathogenesis of CML and may have clinical significance in predicting prognosis of CML.