Background and purpose: MicroRNAs are 19 to 25-nucleotide noncoding RNA molecules. The aim of this article was to investigate the expression and clinical significance of microRNA-141 in childhood B-cell acute lymphoblastic leukemia (ALL). Methods: Bone marrow samples were collected from 35 children with B-cell ALL and 15 children with non hematologic disease. Total RNA was acquired from bone marrow. Real-time PCR was performed to detect the expression level of miR-141. Results: The relative expression level of miR-141 in B-cell ALL group was remarkably lower than those in the control (P0.05). The expression of miR-141 in newly diagnosed samples was lower than those in Day 30 and Week 12 samples respectively (P0.05). Besides

the expression of miR-141 in Day 30 samples was lower than those in week 12 samples (P0.05). The expression of miR-141 in children over 10 years old was significantly lower than those in children under 10 years old (P0.05). The expression of miR-141 in low-risk group was higher than those in mid-risk and high-risk group respectively (P0.05)

and there was significant difference between mid-risk and high-risk groups (P0.05). Conclusion: MiR-141 is likely to have tumor suppressor effect and to be a potential prognostic biomarker in childhood B cell ALL.