OBJECTIVETo screen childhood ALL related microRNAs (miRNAs), analyze association of miRNAs expression profiles with prognosis and relapse in childhood acute lymphoblastic leukemia (ALL) and explore new indicator for predicting relapse and prognosis.

METHODSmiRNAs expression profile was analyzed by gene chip in 49 newly diagnosed childhood ALL and 12 primary immune thrombocytopenia (ITP) cases (as control group). Abnormal expression of miRNAs was verified by qRT-PCR. The correlation of miRNAs expression pattern with indicators predicting early prednisone response and relapse within a year was analyzed.

RESULTSSpecific expression of miRNAs profiles associated with prednisone response and early relapse in childhood ALL was identified. Eight miRNAs (miR-18a, miR-532, miR-218, miR-625, miR-193a, miR-638, miR-550 and miR-633) could distinguish prednisone sensitive from insensitive. The early relapse of newly diagnosed patients with either high-risk or non-high-risk clinical types had some characteristics of abnormal expression of miRNAs, including miR-7, miR-216 and let-7i upregulated, while miR-486, miR-191, miR-150, miR-487 and miR-342 downregulated.

CONCLUSIONSThe initial screening reveals miRNAs differentially expressed from normal in ALL suggesting the potential roles of them in leukemogenesis. MiRNAs expression signatures may be useful for predicting prognosis and relapse in childhood ALL and directing personalized treatment.