ABSTRACT
Objective:To investigate the effect of rapamycin (Rapa) on apoptosis of acute myeloid leukemia THP-1 cells induced by idarubicin (IDA) and its molecular mechanism.Methods:The THP-1 cells were treated with 10, 20, 40 and 80 nmol/L Rapa for 1 h, and the cells without Rapa treatment were set up. Western blot was used to detect the conversion of autophagy marker LC3 protein in THP-1 cells (the ratio of LC3Ⅱ/LC3Ⅰ), flow cytometry was used to detect the apoptotic rate, and the pretreatment concentration of Rapa was determined. THP-1 cells were treated with different concentrations of IDA for 24 h, the cell proliferation inhibition rate of IDA for THP-1 cells was detected by CCK-8 method, and the half maximal inhibitory concentration ( IC50) was calculated. THP-1 cells with or without Rapa treatment were treated by IDA with the concentration of lower than IC50 for 24 h, CCK-8 method was used to detect cell proliferation inhibition rate, flow cytometry was used to detect cell apoptosis, real-time fluorescent quantitative polymerase chain reaction was used to detect the expression changes of autophagy-related genes Beclin-1, LC3 and p62, and Western blot was used to detect the conversion of autophagy marker LC3 protein. Results:The ratio of LC3Ⅱ/LC3Ⅰ in THP-1 cells treated by 20 nmol/L Rapa was higher than that in the untreated cells ( P=0.002 4). The apoptotic rate in THP-1 cells treated by 80 nmol/L Rapa was higher than that in the untreated cells ( P=0.007 3). According to the results of Western blot and flow cytometry, 20 nmol/L Rapa was selected as the pretreatment concentration. The IC50 of IDA for THP-1 cells treated with IDA for 24 h was 59.874 nmol/L. After treated with 50 nmol/L IDA for 24 h, the proliferation inhibitory [(69.67±5.03)% vs. (41.67±3.51)%] and apoptotic rates [(74.35±4.83)% vs. (41.25±5.24)%] in THP-1 cells pretreated by Rapa were higher than those in the unpretreated cells (both P<0.05); the Beclin-1 and LC3 mRNA expression levels and the ratio of LC3Ⅱ/LC3Ⅰ in THP-1 cells pretreated by Rapa were higher than those in the unpretreated cells, and the expression of p62 mRNA was lower than that in the unpretreated cells (all P<0.05). Conclusion:Rapa can enhance the apoptosis of THP-1 cells induced by a relative low dose of IDA, which may be achieved through inducing excessive autophagy in THP-1 cells.
ABSTRACT
Objective@#To explore the clinical and laboratory features of chronic myeloid leukemia(CML) patients with blast phase as initial presentation.@*Methods@#The clinical manifestation, laboratory bindings and treatment of 3 CML patients with blast phase as the initial presentation from January 2015 to November 2016 in Luoyang Central Hospital Affiliated to Zhengzhou University were analyzed. The first symptoms of 3 patients were similar to acute leukemia.@*Results@#The patients were presented with splenomegaly, obvious rise of white blood cell count in peripheral blood, increasing number of initial cells in the bone marrow, Philadelphia chromosome-positive (Ph+), fluorescence in situ hybridization of bcr-abl1 with fusion signals in segmented granulocytes, fusion gene with p210 positive and without the typical chronic phase of CML.@*Conclusions@#Due to the increased number of marrow blasts and the similarity of clinical manifestations to acute leukemia in CML patients with blast phase as the initial presentation, it is easy to misdiagnose as Ph+ acute leukemia in the initial phase. While some differences in genetics, clinical manifestations and genomics between them may help in differential diagnosis.