[Expression and Clinical Significance of MiR-146a and MiR-221 in Childhood Acute T Lymphoblastic Leukemia]

To investigate the expression of miR-146a and miR-211 in peripheral blood mononuclear cells (PBMNC) of children with acute T-lymphoblastic leukemia (T-ALL) and their clinical significance.

One hundred and thirty newly diagnosed children with T-ALL from Hainan Third People's Hospital (T-ALL group) and 50 healthy persons (control group) were selected. The newly diagnosed T-ALL patients before treatment were taken as initial group, the patients reachived complete remission after induction therapy for 33 days were taken as remission group (n=98), the patients not reachived complete remission after induction therapy fore 33 days were taken as rafractory group (n=32). The expression levels of miR-146a and miR-221 in PBMNC were detected by real-time fluorescence quantitative PCR. ROC curve analysis was used to evaluate the diagnostic value of miR-146a and miR-221 for T-ALL, Pearson correlation analysis was used to estimate the correlation of miR-146a and miR-221 expression with white blood cell count in children with T-ALL.

The expression levels of miR-146a and miR-221 of PBMNC in T-ALL group were significantly higher than those in control group (5.83±1.54 vs 0.96±0.17) (7.13±2.60 vs 1.64±0.51) (P＜0.01). The expression levels of miR-146a and miR-221 in refractory group were significantly higher than those in remission group and initial group (8.74±2.35 vs 1.70±0.63 and 5.83±1.54) (11.316±4.83 vs 2.62±0.85 and 7.13±2.60) (P＜0.01). The expression levels of miR-146a and miR-221 correlated with white blood cell count, risk typing and MRD (P＜0.05). ROC curve analysis showed that the best cutoff values of miR-146a and miR-221 for diagnosing childhood T-ALL were 3.90 and 5.28, resoectively. While the AUC (95% CI) of the T-ALL jointy diagnosed by miR-146a and miR-221 was 0.835 (0.764-0.892), and it's sensitivity and specificity were 85.0% and 77.2%, respectively. The correlation analysis showed that the expression levels of miR-146a and miR-221 in PBMNC of children with T-ALL positively correlated with the white blood cell count (r=0.705, r=0.653, P＜0.01), and that of miR-146a positively correlated with miR-221 (r=0.784, P＜0.01).

The expression of miR-146a and miR-221 is up-regulated in children with T-ALL and closely relates with the prognosis of children with T-ALL. The combined detection of miR-146a and miR-221 is certain value for diagnosis of T-ALL.