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Objective: To detect the expression of microRNA-210(miR-210) in childhood acute lymphoblastic leukemia(ALL), and to evaluate the role of the joint detection of miR-210 and MRD in the prognosis and clinical treatment of pediatric ALL., Methods: Eighty-eight children diagnosed with ALL were included in the study. miR-210 was quantitatively detected by real-time quantitative polymerase chain reaction(RQ-PCR) in 88 ALL patients. The average Ct value of samples obtained from 5 pediatric ALL patients with long-term complete continuous remission (CCR>5 years) was used as a calibrator. The expression levels of miR-210 in newly diagnosed patients was calculated by the 2 -ΔΔCt method and presented as multiple changes compared with that of the 5 CCR patients., Results: The expression of miR-210 in the favorable prognosis group was significantly higher than that in the unfavorable prognosis group (10.64±1.5 vs 3.27±0.68)(P<0.05). Compared with the miR-210 high-expression group, poorer relapse-free survival(RFS), event-free survival(EFS) and overall survival(OS) (P all <0.001) were found in the low-expression group. Based on the expression of miR-210 and MRD, the 88 cases were divided into 3 groups. The relapse rate of miR-210-MRD high-risk group (70%) was significantly higher than that of the miR-210-MRD middle-risk group(6.25%) and miR-210-MRD low-risk group (2.1%). Kaplan-Meier survival analysis demonstrated that the miR-210-MRD high-risk group had poorer RFS, EFS and OS than those in other 2 groups (P all <0.01)., Conclusion: The expression level of miR-210 is an independent prognostic factor for pediatric ALL, and the miR-210 is a good useful indicator for predicting the relapse and induction failure of childhood ALL. Joint detection of miR-210 and MRD can help predict outcomes more precisely, thus may be used as an effective mean of determining prognosis, monitoring recurrence, and guiding treatment.

This study was aimed to compare the curative effect of BCH - 2003 protocol and CCLG - 2008 protocol for children with TEL-AML1 fusion gene positive childhood acute lymphoblastic leukemia (ALL) and to investigate the more suitable protocol for this subtype of childhood leukemia. The clinical data for children with TEL-AML1 fusion gene positive ALL admitted from January 2003 to October 2010 in Hematology Center of Beijing Children's Hospital were collected. The common clinical characteristics including prednisone response at day 8, minimal residual disease (MRD) at the end of induction of remission (day 33), event free survival (EFS), relapse free survival (RFS) were compared. The results showed that out of 204 children with TEL-AML1 fusion gene positive ALL, 134 and 70 patients were treated by BCH-2003 protocol and CCLG-2008 protocol respectively. There were no statistical difference in age, white blood cell count in peripheral blood at presentation, prednisone response and CNS involvement. However, there were more boys in CCLG-2008 group (P = 0.025). The negative rate of MRD at day 33 in BCH-2003 group was lower than that in CCLG-2008 group (P = 0.013). After re-stratifying the patients in CCLG-2008 group according to the stratification criteria of BCH-2003 protocol, the negative rate of MRD at day 33 of patients with intermediate risk remained higher in BCH-2003 group than that in CCLG-2008 group (P = 0.014) . However, no significant difference in the patients with standard risk was found. There were also no significant statistical differences in the incidence of severe infection, EFS and RFS, (P = 1.000, P = 0.327,P = 0.251 respectively) during chemotherapy. It is concluded that for children with TEL-AML1 fusion gene positive ALL, the induction of remission of BCH - 2003 protocol can decrease leukemic load more quickly than that of CCLG - 2008 protocol. However, the outcome of the patients treated by the two protocols is similar.

The aim of this study was to investigate the effect of suppression of nicotinamide phosphoribosyltransferase (NAMPT) expression on imatinib-sensitivity in chronic myelogenous leukemia (CML) cell line K562 and its mechanisms, NAMPT siRNA was synthesized and transfected into K562 cells. PI/Calcein staining technique was used to determine survival rate of transfected K562 cells at 48th hour after exposure to 1 µmol/L imatinib. MTS method was used to determine the proliferation changes of transfected K562 cell at 48th hour after exposure to different doses of imatinib, then half inhibitory concentration (IC(50)) was calculated. Expression of NAMPT at 3rd-48th hour after exposure to 1 µmol/L imatinib was determined by Western blot. To explore the effect of NAMPT-siRNA and imatinib on the expression of apoptosis-related genes, the microarray data from NCBI GEO Data-Sets was analyzed, then the results were confirmed by Western blot. The luciferase reporter assay was used to determine the effect of NAMPT and imatinib on transcriptional activity of NF-κB transcription factors. The results showed that after exposure to 1 µmol/L imatinib for 3 - 48 h, there was no significant change of NAMPT expression in K562 cells. The expression of NAMPT could be effectively inhibited by the NAMPT-siRNA. After exposure to 1 µmol/L of imatinib for 48 h, the survival rate of NAMPT-siRNA interference group was lower than that of negative control group (P < 0.05), indicating that suppression of NAMPT expression can increase the sensitivity of K562 cells to imatinib and enhance the killing effect of imatinib on K562 cells. The IC(50) of imatinib in NAMPT-siRNA interference group was the lowest compared with that of control group (P < 0.05) after exposure to different concentrations of imatinib for 48 h, the fitted survival curves showed that the slope of NAMPT-siRNA interference group was the largest ranging between 0.01 - 0.1 µmol/L of imatinib. Data mining of expression profiling indicated that the anti-apoptotic factor Bcl-2 decreased in K562 cells treated with either NAMPT-siRNA or imatinib, which was confirmed by Western blot. The inhibitory effect was much more significant when both NAMPT-siRNA and imatinib were used. The results of luciferase reporter assay showed that either NAMPT-siRNA or imatinib decreased transcriptional activity of NF-κB. The decreased effect was much more significant when both NAMPT-siRNA and imatinib were used. It is concluded that survival of K562 cells affected by imatinib may not be due to regulation of expression of NAMPT. When expression of NAMPT decreases, the K562 cells are more sensitive to imatinib, this may be related with the decreased transcriptional activity of NF-κB and its downstream effector Bcl-2.