Abstract:

Objective To investigate the expression characteristics of Wilm's tumor 1 gene (WT1), preferentially expressed antigen of melanoma (PRAME) and ETS related genes (ERG) in acute leukemia of children, and explore the significance in monitoring of minimal residual disease (MRD) of leukemia. Methods Ninety-two samples of acute leukemia (84 children) were collected. Twenty-eight samples were newly diagnosed ones, including 18 samples of acute lymphoblastic leukemia (ALL) and 10 samples of acute myeloid leukemia (AML). Sixty-three samples were complete remission ones, including 45 samples of ALL and 18 samples of AML. The other 1 sample was a relapse one. The expression of WT1, PRAME and ERG mRNA in bone marrow was detected by Real-time PCR. Another 10 cases of non-malignant hematological diseases of the same period were served as controls. Results The relative expression of WT1, PRAME and ERG mRNA in newly diagnosed group was significantly higher than that in complete remission group and control group (P<0.05), while there was no significant difference between complete remission group and control group (P>0.05), and the relative expression of PRAME mRNA in newly diagnosed AML group was significantly higher than that in newly diagnosed ALL group (P<0.05). The positive expression rates of WT1, PRAME and ERG mRNA in newly diagnosed group were 82.4%, 92.9% and 64.3% respectively, and there were significant differences among them (P<0.05). The positive rate of joint detection of 3 genes was 100%. The relative expression of 3 genes after induction chemotherapy was significantly lower than that before induction chemotherapy in 15 newly diagnosed patients (P<0.05). The expression of 3 genes in the patient with relapse was positive at the disease onset, negative after remission, and positive again at relapse. Conclusion Compared with patients without leukemia, WT1, PRAME and ERG mRNA is highly expressed in bone marrow of patients with newly diagnosed acute leukemia, and the joint detection of 3 genes may increase the positive rate. The expression of WT1, PRAME and ERG mRNA is related to the disease status in patients with acute leukemia, and may be a useful tool for monitoring MRD.

Key words: acute leukemia, children, Wilm's tumor 1 gene, preferentially expressed antigen of melanoma, ETS related genes, minimal residual disease