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Deletion of the long arm of chromosome 20 (del(20q)) is observed in 5-10% of patients with myelodysplastic syndromes (MDS). We examined the expression of 28 genes within the common deleted region (CDR) of del(20q), which we previously determined by a CGH array using clinical samples, in 48 MDS patients with (n = 28) or without (n = 20) chromosome 20 abnormalities and control subjects (n = 10). The expression level of 8 of 28 genes was significantly reduced in MDS patients with chromosome 20 abnormalities compared to that of control subjects. In addition, the expression of BCAS4, ADA, and YWHAB genes was significantly reduced in MDS patients without chromosome 20 abnormalities, which suggests that these three genes were commonly involved in the molecular pathogenesis of MDS. To evaluate the clinical significance, we analyzed the impact of the expression level of each gene on overall survival (OS). According to the Cox proportional hazard model, multivariate analysis indicated that reduced BCAS4 expression was associated with inferior OS, but the difference was not significant (HR, 3.77; 95% CI, 0.995-17.17; P = 0.0509). Functional analyses are needed to understand the biological significance of reduced expression of these genes in the pathogenesis of MDS., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

We performed methylation specific PCR analysis on the RIZ1 promoter in MDS and AML. Methylation was detected in 17 of 34 MDS (50%) and 22 of 72 AML (31%) (p=0.053). Methylation was detected in eleven of 17 secondary AML from MDS (65%), and eleven of 55 de novo AML (20%) (p=0.0005). Bisulfite sequence revealed methylation at many CpG sites in the promoter. Decreased RIZ1 expression was accompanied by methylation in six of nine samples examined, while it was also observed in seven of 13 without methylation. Treatment of AML cells, that have RIZ1 methylation, with 5-Aza-dC, induced growth suppression with RIZ1 restoration. Our results suggest that the RIZ1 gene is inactivated in MDS and AML in part by methylation, whereas another mechanism should be involved in others., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The DNA topoisomerase IIalpha (Topo IIalpha) is known as a target enzyme for many chemotherapeutic agents. We investigated the Topo IIalpha mRNA expression by real-time RT-PCR in 37 paired samples at diagnosis and at relapse of acute leukemic patients in relation to drug sensitivity and clinical outcome. The Topo IIalpha levels in leukemic blasts at relapse were significantly higher than that at diagnosis, especially in ALL. The increase in the Topo IIalpha level at relapse was significant in cases which could not achieve a second remission, but not significant in cases which achieved a second remission. These results suggest that the change of Topo IIalpha expression in leukemic blasts at relapse may predict therapeutic responsiveness.