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A little is known about the specific marker on the surface of acute leukemia cells, leading to the lack of the specific diagnosis method for acute leukemia. Therefore, in this study, cell-systematic evolution of ligands by exponential enrichment (cSELEX) was performed to screen the aptamers binding to CD33(+)/CD34(+) cells from the patients with acute myeloblastic leukemia (AML) of M(2) subtype (AML-M₂) so as to provide the basis for finding the specific marker on the surface of AML-M(2) CD33(+)/CD34(+) cells. Firstly, AML-M₂ CD33(+)/CD34(+) cells were sorted and used as targeted cells, and normal CD33(+)/CD34(+)cells were used as counter-targeted cells; the aptamers binding to CD33(+)/CD34(+) cells from patients with AML-M₂ were screened from the single strand deoxyribonucleic acid (ssDNA) library by cSELEX. Subsequently, each aptamer structure was analyzed after cloning and sequencing. The results indicated that after 13 round of screenings, the enrichment of aptamers in the ssDNA library was ranged from 0.7% to 52.9%, and reached steady state at 13th round screening. Sequence analysis for 30 aptamers showed that most of the aptamers born one of the three conserved sequences of CCCCT, CTCTC, and CTCAC. Secondary structure analysis indicated that three different secondary structures existed in these aptamers. It is concluded that the aptamers binding to the AML-M(2) CD33(+)/CD34(+) cells are successfully screened, which lay the basis for further looking for the specific marker on the surface of AML-M₂ CD33(+)/CD34(+) cells, and the molecular diagnosis of the AML-M₂ leukemia.

Constitutive activation of nuclear transcription factor-κB (NF-κB) exists in a variety of leukemia, and induction of apoptosis through blocking NF-κB activation may be an alternative strategy for leukemia treatment. The aim of this study was to investigate the inducing effect of modified adenovirus 5-based adenovirus vector (i.e. chimeric Ad5F35 Vec)-mediated expression of mutant IκBα (IκBαDN) on apoptosis of HL-60 cells. The recombinant Ad5F35-IκBαDN Vec carrying IκBαDN cDNA which deleted the first 1-70 amino acids coding sequences at 5' terminal of human IκBα was transfected into HL-60 cells. The apoptosis, NF-κB DNA binding activity, the expressions of IκBα, cIAP-2 and xIAP in HL-60 cells were detected by DNA binding assay, flow cytometry, real-time quantitative polymerase chain reaction and Western blot respectively. The results showed that apoptosis rates were 22.53 ± 2.999%, 6.08 ± 2.464% and 4.86 ± 1.366% for Ad5F35-IκBαDN Vec-infected or blank vector of Ad5F35-EGFP Vec-transfected and untransfected HL-60 cells respectively, which showed a significant difference between Ad5F35-IκBαDN Vec-transfected and untransfected cells (p < 0.001) and between Ad5F35-IκBαDN Vec-transfected and Ad5F35-EGFP Vec-transfected cells (p < 0.001, p < 0.002), while NF-κB DNA binding activity was decreased, the truncated IκBα was expressed, and IκBα mRNA expression was up-regulated, but the expression of cIAP-2 and xIAP mRNA was down-regulated after transduction for 48 hours. It is concluded that the chimeric Ad5F35 Vec can effectively mediate the expression of IκBαDN cDNA in HL-60 cells, leading to the inhibition of NF-κB DNA binding activity and inducing apoptosis of HL-60 cells.

The study was aimed to investigate the expression of VEGF mRNA and VEGF protein in HL-60 cells treated with diallyl disulfide (DADS), and to explore the antileukemic mechanism of DADS in respect of VEGF production. Semi-quantitative RT-PCR and ELISA were used to detect the expression of VEGF mRNA and secretion of VEGF protein in HL-60 cell lines treated by DADS respectively. The results showed that the expression of VEGF mRNA and secretion of VEGF protein were found in HL-60 cells. The expression of VEGF mRNA and secretion of VEGF protein in HL-60 cells could be down regulated by treatment with 0.625, 1.25, and 2.5 microg/mL DADS for 48 and 72 hours and the effects had a dose dependent relationship (r > 0.9, P < 0.01). The differences between DADS treated HL-60 cell groups and the control group were statistically significant (P < 0.01), there were also statistically significant differences among three DADS-treated HL-60 cell groups (P < 0.05). It is concluded that DADS effectively inhibits the proliferation of human leukemia cell line HL-60 cells; DADS exerts its antileukemic effects by reduction of the expression of VEGF mRNA and VEGF protein secretion.