Expression and Clinical Significance of DNMT in Patients with Chronic Myeloid Leukemia

Abstract

To investigate the expression and clinical significance of DNA methyltransferases (DNMT) mRNA in patients with chronic myeloid leukemia (CML). The expression levels of DNMT mRNA in mononucllear cells (MNC) of bone marrow or in peripheral blood of 93 CML patients in 3 different phases and 10 normal controls (NC) were detected by SYBR Green flurescent quatitative PCR. The relative expression levels of DNMT1 mRNA in NC, chronic phase CML (CML-CP), accelerated phase (CML-AP) and blastic phase (CML-BP) were 1.45 ± 0.22, 1.83 ± 0.63, 2.95 ± 0.87 and 3.24 ± 1.39 resectively. The expression of DNMT1 mRNA showed no statistically significant difference between CML-CP and NC (P = 0.28). The expression of DNMT1 mRNA in advanced stages (including CML-AP and CML-BP) of CML obviously increased in comparison with CML-CP and NC (P < 0.05). The expression of DNMT1 mRNA in CML-AP was not significantly different from that in CML-BP (P = 0.336). The relative expression levels of DNMT3a mRNA in NC, CML-CP, CML-AP and CML-BP groups were 1.29 ± 0.34, 1.34 ± 0.46, 2.33 ± 1.05 and 3.18 ± 1.23 resectively. And the expression levels of DNMT3a mRNA were not statistically significantly different between CML-CP and NC (P = 0.844). The results showed that the expression of DNMT3a mRNA in the advanced phase of CML significantly increased in comparison with that in CML-CP and NC (P < 0.05). Meanwhile, the expression of DNMT3a mRNA in CML-AP was not different from that in CML-BP (P = 0.304). The relative expression levels of DNMT3b mRNA in NC, CML-CP, CML-AP and CML-BP groups were 1.37 ± 0.31, 16.41 ± 22.50, 9.36 ± 5.50 and 12.17 ± 13.44 resectively. It was also found that the level of DNMT3b mRNA in CML significantly increased in comparison with NC (P < 0.05), and that the between the 3 different phase of CML was not statistically significantly different (P >0.05). The expression of DNMT mRNA increases in advanced CML as compared with normal controls and CML-CP, and the increased levels of DNMT mRNA probably correlate with disease progression in CML.