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Aberrant DNA methylation of various genes has been identified to be associated with disease progression in chronic myeloid leukemia (CML). Our study was intended to investigate DLX4 methylation pattern in different clinical stages of CML and further determine its role in regulating DLX4 expression. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were applied to detect DLX4 methylation. 5-aza-2′-deoxycytidine (5-aza-dC) was used for demethylation studies. DLX4 was significantly hypermethylated in CML patients ( P = 0.002) especially in blastic phase (BC) stage ( P < 0.001) as compared with controls. Moreover, DLX4 methylation level in BC stage was significantly higher than in chronic phase (CP) stage ( P < 0.001). DLX4 methylation density was significantly increased during the progression of CML among the tested two patients ( P < 0.001). DLX4 hypermethylation occurred with the highest incidence in BC stage (83%), lower incidence in acute phase (AP) stage (43%), and the lowest incidence in CP stage (26%) ( P = 0.001). Moreover, t(9; 22) with additional alteration cases had significantly higher frequency of DLX4 hypermethylation compared with the other cytogenetics ( P = 0.010). Significantly negative correlation was observed between DLX4 methylation and DLX4-TV2 (the shorter DLX4 isoform) expression (R = −0.382, P = 0.001, n = 78) but not between DLX4 methylation and BP1 (the longer DLX4 isoform) expression (R = 0.134, P = 0.244, n = 78) in CML patients. Both DLX4-TV2 and BP1 mRNA were significantly increased after 5-aza-dC treatment in K562 cell line ( P < 0.001). Our study indicated that hypermethylation of DLX4 correlated with disease progression of CML. Moreover, DLX4 expression was regulated by its methylation in CML. [ABSTRACT FROM AUTHOR]

Abstract: MicroRNAs (miRNAs) are endogenous small noncoding RNA molecules that suppress gene expression via degradation or translational inhibition of their target genes. Many miRNAs are associated with cardiac hypertrophy and heart failure. In this study, we pursued to identify miRNAs that negatively regulate cardiac hypertrophy by utilizing a surgical model for regression of cardiac hypertrophy. Microarray analysis revealed that 15 miRNAs out of the 696 miRNAs tested were specifically up-regulated during the regression period. Among these regression-specific miRNAs, nine microRNAs, which have not been previously reported, were further tested for their effects on phenylephrine (PE)-treated neonatal cardiomyocytes. Consequently, five miRNAs (miR-101b, 142-3p, 181d, 24-2∗, and 450a) completely abrogated PE-induced hypertrophy as determined by measurements of cell size and fetal gene expression. Conversely, antagomers of these miRNAs exacerbated the PE-induced hypertrophy. Collectively, these findings suggest that the five miRNAs newly identified by using our cardiac hypertrophy-regression surgical model negatively regulate cardiac hypertrophy and could be used as potential therapeutic targets for the treatment of heart diseases. [Copyright &y& Elsevier]