To investigate the expression level and analyze the clinical significance of NT5C2, which is an
nucleoside analogues metabolism related gene, in children with acute
leukemia (AL).
METHODS: Real-time PCR and immunohistochemistry were presented to detect the level of NT5C2
mRNA and its
protein product cN- Ⅱ in bone marrow samples of 63 patients initially diagnosed with AL, 15 patients who achieved complete remission, 7 patients who relapsed and 16 non- hematologic malignancie controls. The expression of NT5C2
mRNA in different groups of AL and its relevance with clinical indicators were analyzed.
RESULTS: ①The expression of NT5C2
mRNA in newly diagnosed B-ALL, TALL, AML and controls were 1.16 (0.89-2.25, 0.96 (0.74-1.25, 1.66 (0.84-3.15) and 0.88 (0.61-1.21), respectively. NT5C2
mRNA expression in AML (P<0.01) and B-ALL (P<0.05) cases were higher than that in controls; NT5C2
mRNA expression in
T- ALL and in controls showed no significant difference (P>0.05). Changes of NT5C2
mRNA level were observed between preliminary diagnosis and complete remission in 15 patients. NT5C2
mRNA levels were significantly decreased
in complete remission stage than that in newly diagnosis AL (P<0.01). NT5C2
mRNA levels of relapsed-refractory group were higher than that of complete remission group and controls (P<0.01). ② Immunohistochemical staining results revealed that NT5C2
protein levels were consistent with the trend of
mRNA levels. ③NT5C2
mRNA levels in AML (r=0.434) and
T-ALL (r=0.389) were positively correlated with risk classification (P<0.05). ④ During
chemotherapy of patients with AML, the NR rate of bone marrow in NT5C2 high expression group was higher than that of low expression group after 9 days
induction chemotherapy (35.2% vs 0) and before consolidation
therapy (25.0% vs 0); The positive rate of
minimal-residual disease (36.4% vs 14.3%) and relapse rate of AL (38.5% vs 28.6%) were increased in NT5C2 high expressed patients than that in low expressed patients, but all the differences were insignificant (P>0.05).
CONCLUSION: High expression of NT5C2 was found to be a related risk factor of AL children with unfavourable prognosis. NT5C2 promises a new target for guiding individualized
chemotherapy and evaluating the prognosis of childhood acute
leukemia and monitoring recurrence.