[Methylation Status and mRNA Expression of DKK-3 and WIF-1 in Acute Myeloid Leukemia Patients].

OBJECTIVE: To analyze the promoter methylation status, mRNA expression and clinical significance of DKK-3 and WIF-1 genes in patients with acute myeloid leukemia(AML).

METHODS: Methylation specific polymerase chain reaction (MS-PCR) mothod was carried out to detect DKK-3 and WIF-1 gene promoter methylation status in bone marrow specimen from 56 patients with AML and 20 patients with iron deficiency anaemia(IDA) as control; then the real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) was used to detect mRNA expression of DKK-3, WIF-1 gene and β -catenin in the above-mentioned specinens, and their relationship with the clinical features and survival time was analyzed.

RESULTS: The promoter methylation rate of DKK-3 and WIF-1 gene in AML patients were significantly higher than that in control group(χ2 =15.330,P<0.001; χ2 =17.371,P<0.001). There was no relationship between DKK-3 and WIF-1 gene promoter methylation rate and AML patient's sex, age, clinical typing. The relative expression of DKK-3 and WIF-1 gene mRNA in AML group were 0.840±0.320 and 0.792±0.313, which were lower than those in control group (1.134±0.392 and 1.047±0.334) respectively, the difference was statistically significant (t=3.415,P=0.000; t=3.070, P=0.003). The relative expression of β-catenin mRNA in AML bone marrow specimens in AML group was 0.756±0.304, which was higher than that in control group(0.342±0.105), the difference was statistically significant (t=5.943, P=0.001). The expression of DKK-3 and WIF-1 gene mRNA negatively correlated with β-catenin mRNA(r=-0.543; r=-0.562). Kaplan Meier survival curve analysis showed that overall survival time in AML patients with DKK-3 gene methylation was shorter than that in the AML patients with DKK-3 gene unmethylation(χ2 =3.957, P=0.042). Futhermore, the orerall survival time in AML patients with WIF-1 gene methylation was also shorter than that in AML patients with WIF-1 gene unmethylation (χ2 =4.520, P=0.029).

CONCLUSION: Wnt/β-catenin signaling pathway is abnormally activated in AML patients, the DKK-3 and WIF-1 gene promoter methylation may be involved in Wnt pathways activation and the pathogenesis of AML.