ABSTRACT
Objective To investigate the effect of fluacrypyrim on the induction of apoptosis in human acute myeloid leuke-mia(AML)cell lines,NB4,THP-1 and HL-60,and explore the related mechanisms.Methods Trypan blue dye exclusion assay was used to estimate the growth of NB4,THP-1,and HL-60 cells after treatment with various concentrations of fluacrypyrim(1.25, 2.5,5 and 7.5 μmol/L)for 72 h.Cell apoptosis was evaluated by AnnexinⅤ-FITC/PI double stainning for the NB4 and THP-1 cells treated with fluacrypyrim(1.25,2.5 and 5 μmol/L)for 48 h as well as the HL-60 cells treated with fluacrypyrim(2.5,5 and 7.5 μmol/L) for 72 h.Western blotting was used to examine the protein expression of apoptotic regulators Bax,Mcl-1 and Caspase 3 in the NB4 cells treated with fluacrypyrim(1.25,2.5 and 5 μmol/L)for 24 h.Then,NB4 Cells were pretreated with Caspases inhibitor benzyloxy-carbonyl-Val-Ala-Asp-fluoromethylketone(Z-VAD-FMK)and exposed to fluacrypyrim at 2.5 μmol/L for 24 h,which was then evaluat-ed for the apoptosis using AnnexinⅤ-FITC/PI double stainning.Western blotting was used to examine the expression of the phosphory-lated and total proteins of mitogen-activated protein kinase(MAPK)signaling molecules,ERK,JNK and P38,in the NB4 cells treat-ed with fluacrypyrim(1.25,2.5 and 5 μmol/L)for 24 h. NB4 Cells were pretreated with ERK inhibitor U0126,JNK inhibitor SP600125,or P38 inhibitor SB203580 for 1 h and then exposed to fluacrypyrim at 2.5 μmol/L for 24 h,which was then analyzed for the apoptosis by the AnnexinⅤ-FITC/PI double stainning.Results The proliferation of NB4,THP-1 and HL-60 cells was inhibited by the treatment with fluacrypyrim(2.5,5 and 7.5 μmol/L)for 72 h.The apoptosis induced in the NB4 and THP-1 cells by the fluacry-pyrim treatment at 5 μmol/L for 48 h and in the HL-60 cells by the fluacrypyrim treatment at 7.5 μmol/L for 72 h were significant as compared with the control group(P<0.01).Mechanically,fluacrypyrim at the concentrations of 2.5 and 5 μmol/L effectively up-regu-lated the expression of Bax(P<0.01 and P<0.05)for the 2.5 and 5 μmol/L,respectively,down-regulated the expression of Mcl-1 (P<0.01)and activated Caspase 3(P<0.01)in the NB4 cells when compared with the control group(P<0.01).The pretreatment of the NB4 cells with Z-VAD-FMK blocked the apoptosis induced by fluacrypyrim.Furthermore,the fluacrypyrim(2.5 and 5 μmol/L) treatment increased the ERK,JNK and P38 phosphorylation(P<0.01),while the pretreatment of the NB4 cells with U0126 signifi-cantly inhibited the the fluacrypyrim-induced apoptosis(P<0.01),as compared with the control group.Conclusion Fluacrypyrim effectively inhibits the cell proliferation and induces caspase-dependent cell apoptosis in AML cells.Activation of ERK/MAPK signal-ing pathway might play an important role in the action of fluacrypyrim.
ABSTRACT
<p><b>OBJECTIVE</b>To study the therapeutic effect of rhSCF early administration on rhesus monkeys with severe acute radiation sickness(ARS).</p><p><b>METHODS</b>Twelve adult monkeys totally exposed to 7.0 GyCo were divided into radiation control and SCF groups, and monkeys in SCF group were subcutaneously injected recombinant human SCF(rhSCF) 200 µg/kg at half an hour and 24 hour after irradiation, while the radiation control monkeys were injected physiological saline. Survival was monitored and hematopoiesis was evaluated at 40 days following early treatment.</p><p><b>RESULTS</b>6 animals treated with rhSCF all survived, while 2 in irradiated controls survived on 40 day after radiation. rhSCF treatment promoted hematopoiesis recovery significantly, increased the nadir of white blood cells, neutrophils and platelets, and simplified supportive care in ARS rhesus monkeys.</p><p><b>CONCLUSION</b>RhSCF injection soon after TBI taken shows an significant therapeutic efficiency on rhesus monkeys with severe acute radiation sickness.</p>