Increased Mir-155 Expression Is Associated with FLT3-ITD Mutation and Poor Therapy Response in Chinese AML and Allo-HSCT Could Improve Survival of These Patients

The aim of this study was to evaluate the diagnostic and prognostic value of miR-155 in Chinese acute myeloid leukemia (AML) patients. The miR-155 levels of 142 de novo AML patients and 28 healthy donors were detected by real-time quantitative PCR (RQ-PCR). The miR-155 expression was significantly up-regulated in AML compared with control (p<0.001). A receiver operating characteristic (ROC) curve revealed that miR-155 expression could differentiate patients with AML from control subjects (AUC=0.907, 95%CI: 0.853-0.960, P<0.001). We also monitored the miR-155 level in 22 de novo AML patients and found that the miR-155 level decreased significantly from the initial diagnosis to post-CR (P<0.001). FLT3 internal tandem duplication (FLT3-ITD) mutation was significantly more frequent in miR-155 high-expressed group versus low-expressed group (p=0.002). Considering all patients, miR-155 high-expressed cases had significantly lower complete remission (CR) and part remission (PR) rate than miR-155 low-expressed cases (p=0.04). Survival analysis was performed in non-M3-AML patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) as consolidation therapy. Kaplan-Meier demonstrated that there was no difference in leukemia free survival (LFS) and overall survival (OS) between miR-155 high-expressed and low-expressed patients (p>0.05). Collectively, Increased miR-155 expression is associated with FLT3-ITD mutation and poor therapy response in Chinese AML and allo-HSCT could improve survival of these patients.