[Combined effect of TNF-related apoptosis induced ligand and Ara-C in inducing apoptosis of HL-60 cells and its mechanism].
To investigate the combined effect of human recombinant soluble TNF-related apoptosis induced ligand (hrsTRAIL) with Ara-C or alone on HL-60 leukemia cell lines and its mechanism, human leukemia cell lines HL-60 were cultured in vitro. HL-60 cells were divided into 5 groups: control group, Ara-C group, rsTRAIL group, Ara-C + rsTRAIL simultaneously given group, Ara-C + rsTRAIL tandem given group (Ara-C followed by rsTRAIL group). The cytotoxic effect was measured by MTT assay; cell apoptosis rate was determined by flow cytometry after Annexin V/PI staining; the expression level of DR5 on surface of HL-60 cells treated with Ara-C at different concentrations for 24 hours was determined by flow cytometry. The expression level of DR5 on surface of HL-60 cells and caspase-8 activity in HL-60 cells of rsTRAIL group and Ara-C + rsTRAIL tandem group was determined by flow cytometry. The result showed that rsTRAIL could inhibit the proliferation of HL-60 cells and induce apoptosis of HL-60 cells in a concentration-dependent manner. The apoptosis rate of HL-60 cells in Ara-C + rsTRAIL tandem given group was higher than that in Ara-C + rsTRAIL simultaneously given group, the expression level of DR5 on surface of HL-60 cells and intracellular activity of caspase-8 in Ara-C + rsTRAIL tandem given group were higher than those in rsTRAIL group. When HL-60 cells treated with 5 and 10 mg/L of Ara-C for 24 hours, the expression level of DR5 on surface of HL-60 cells was higher than that in control group. It is concluded that rsTRAIL can inhibit the proliferation of HL-60 cells, and induce apoptosis of HL-60 cells. Ara-C can upregulate DR5 expression on the surface of HL-60 cells and enhance the effect of rsTRAIL-inducing apoptosis. Tandem treatment of HL-60 cells with Ara-C followed by rsTRAIL induce more apoptosis than that of co-treatment with rsTRAIL and Ara-C. Ara-C and rsTRAIL has a synergistic inhibitory effect on growth of HL-60 cells. The mechanism may correlate with up-regulation of the expression level of DR5 and/or caspase-8 in HL-60 cells by Ara-C.
Medical College of Nanchang University, Nangchang 330006, Jiangxi Province, China.
Jia
J
Rao
Rong-Yan
RY
Zhang
Yan
Y
Chen
Guo-An
GA
Chen
Cheng-Jing
CJ
Xiao
D017209:Apoptosis / Q000187:drug effects*; D053181:Caspase 8 / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D003561:Cytarabine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D018922:HL-60 Cells; D006801:Humans; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D053221:TNF-Related Apoptosis-Inducing Ligand / Q000494:pharmacology*; D015854:Up-Regulation
D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D011994:Recombinant Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; D003561:Cytarabine; D053181:Caspase 8