Clinical and prognostic significance of ABO promotor methylation level in adult leukemia and myelodydysplastic syndrome

Abstract

Objective: To investigate the clinical and prognostic significance of ABO promotor methylation level in adult patients with leukemia and myelodydysplastic syndrome(MDS). Methods: ABO promoter methylation level of 182 malignant hematological disease patients and 68 normal controls were detected by bisulfite sequencing PCR.Then clinical features and outcome were compared between hypermethylation group and hypomethylation group. Results: The median methylation rate of ABO promoter in newly diagnosed acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) were 46.98% and 11.01% respectively, which were both higher than that in controls (2.30%, P<0.05). The methylation rates in remission AML and ALL were 1.58% and 2.30% respectively, which were comparable with that in normal group (P>0.05). As to relapse AML and ALL, methylation rates were 41.26% and 17.50% respectively, also significantly higher than that in controls (P<0.05).In patients with chronic myeloid leukemia (CML) chronic phase, the median methylation rate was 1.00%, which was similar to normal group. But a CML patient who transformed to ALL hadextremely high methylation rate 92.56%. The median methylation rate in patients with MDS significantly elevated as 5.81% compared with that in controls (P<0.05). The median overall survival (OS) of ALL and AML (non-M3) patients with hypermethylation were 12.5 months and 15.3 months, which were significantly shorter than those with hypomethylation (24.0 months and 20.0 months)(P<0.05).The median disease-free survival (DFS) of ALL and AML (non-M3) patients with hypermethylation were 9.9 months and 12.0 months, which were significantly shorter than those with hypomethylation (22.3 months and 18.5 months), (P<0.05). Multivariable analysis suggested that ABO promoter methylation level was an independent predictive factor of OS and DFS in ALL and AML (non-M(3)) patients. Conclusion: ABO promoter hypermethylation is closely related to genesis, development and prognosis of leukemia and MDS. Hypermethylationis related to a clinical poor prognosis compare with hypomethylation.