Expression of eIF4E in patients with leukemia and its clinical significance / 中国实验血液学杂志

This study was aimed to compare the expression level of eIF4E in patients with leukemia and normal controls, and to explore its role in leukemogenesis. White blood cells were collected in 76 leukemia patients and 10 healthy volunteers. The mRNA and protein expressions of eIF4E were detected by QT-PCR and Western blot in 39 cases of acute myeloid leukemia (AML), 15 cases of chronic myeloid leukemia (CML), 22 cases of acute lymphocytic leukemia (ALL) and 10 healthy volunteers as normal controls. The results demonstrated that compared with normal controls, the absolute expression levels of eIF4E mRNA increased in patients with AML, ALL and CML in blastic phase (P < 0.05), but had no significant change between groups of CML in chronic and accelerated phase although some increasing in group of CML in accelerated phase. The relative expression level of eIF4E mRNA had no significant change in AML, ALL, CML groups except the two subtypes of leukemia M4 and M5. Furthermore, the protein expression level in group of CML in accelerated phase and blastic phase and all acute leukemia patients including AML and ALL were higher than that in normal controls (P < 0.05). It is concluded that although its mRNA relative expressions had no significant change in most leukemia patients, the absolute expression level of eIF4E mRNA and its protein expression is up-regulated in most leukemia patients, which may play an important role in leukemogenesis, so the eIF4E may be a promising target for leukemia therapy and eIF4E-targeted therapy may be an option especially for the relapse and refractory leukemia.

Reversing effects of emodin on multidrug resistance in resistant HL-60/ADR cells / 中国实验血液学杂志

This study was aimed to investigate the reversing effects of emodin on multidrug resistance (MDR) in resistant HL-60/ADR cells, and to explore the underlying mechanisms. The MTT assay was used to assess the chemoresistance of HL-60/ADR cells to emodin and 8 chemotherapeutic agents commonly used in clinic. The reversal effects of emodin on MDR of HL-60/ADR cells were also evaluated by MTT method. DNA ploidy analysis and DNA Ladder assay were used to detect apoptosis-induced effects on HL-60/ADR cells via the adriamycin (ADR) and emodin combination. The expression changes of the drug resistance-associated genes and proteins were detected by RT-PCR and Western Blot respectively. The intracellular accumulation and subcellular distribution of ADR and DNR were measured by flow cytometry and confocal laser scanning microscopy. The results showed that emodin inhibited HL-60/ADR cell proliferation with an average IC50 value of 24.09 ± 1.72 µmol/L, which was similar to that of the parental HL-60 cells (average IC50 = 23.18 ± 0.87 µmol/L). HL-60/ADR cells were resistant to a variety of chemotherapeutic agents, such as ADR, DNR, VP16, VCR,Ara-C, HHT, MTZ and THP. The reversal multiple were between 1.58 and 4.12 after the treatment with low concentration of emodin combined with the above mentioned different agents. The combination of ADR with emodin showed the best reversal effects, and the typical hypodiploid peak (apoptotic peak) and DNA ladder could be detected after the co-treatment.In addition, emodin down-regulated the mRNA and protein expression levels of MRP1, TOPOIIβ, GST π and BCL-2. Furthermore, the addition of emodin enhanced ADR and DNR intracellular accumulation and subcellular distribution in HL-60/ADR cells in dose-dependent manner. It is concluded that the emodin shows reversing effects on the multidrug resistant HL-60/ADR cells, possibly via decreasing the expression levels of drug resistance-associated genes, increasing the intracellular accumulation of chemotherapeutic agents and activating the apoptosis pathway.

Effects of emodin on the proliferation inhibition and apoptosis induction in HL-60 cells and the involvement of c-myc gene / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of emodin on apoptosis induction and proliferation inhibition in human apoptosis and on c-myc protein and mRNA expression in human myeloid leukemia cell line HL-60 cells.</p><p><b>METHODS</b>HL-60 cells were exposed to emodin at different dosages. Growth inhibition was detected by MTT assay and colony formation assay, and cell apoptosis by flow cytometry, TUNEL labeling method, DNA fragmentation and MitoCapture apoptosis detection. The expression of c-myc was detected by RT-PCR and Western-blot.</p><p><b>RESULTS</b>Emodin remarkably inhibited the cell proliferation, with an IC(50) value of 20 micromol/L. HL-60 cells apoptosis could be efficiently induced by emodin in a dose dependent manner. The c-myc protein and mRNA expressions on HL-60 cells were decreased after emodin treatment.</p><p><b>CONCLUSION</b>Emodin could efficiently induce growth inhibition and apoptosis in HL-60 cells. c-myc may be involved in this process.</p>