Screening and expression of CD34(+) cell-specific microRNA in acute myelogenous leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To screen and analyze CD34(+) cell specific microRNAs (miRNAs) from the patients with acute myelogenous leukemia (AML) and their expression.</p><p><b>METHODS</b>CD34(+) cells were sorted from AML patients or the mobilized peripheral blood of the donors of hematopoietic stem cell transplantation (normal control subjects) and followed by the extraction of the cell total RNAs. The differentially expressed microRNAs (miRNAs, miR) were selected after hybridizing with miRNA microarray, real time polymerase chain reaction (real-time PCR) was subsequently applied to confirm the expression of the selected miRs, and PCR products were further cloned and sequenced to check their specificity.</p><p><b>RESULTS</b>Of the differentially expressed miRNAs, 191 were found to be at least one-fold change in the CD34(+) cells between the AML patients and the normal control subjects. Of the 191 miRNAs, the expression difference of 94 was significant (P < 0.05). Among these 94 miRNAs, the expression of 44 miRNAs was increased and the other 50 miRNAs was decreased in the CD34(+) cells from the bone marrow of AML patients compared with the CD34(+) cells from the mobilized peripheral blood of the normal control subjects. Real time PCR verified that the expression level of miR-10a and miR-220c in the CD34(+) cells from the bone marrow of AML patients was 19.6% and 19.0% of that of CD34(+) cells from mobilized peripheral blood of the normal control subjects. DNA sequencing and BLAST DNA database searching results indicated that the PCR products were really miR-10a and miR-220c.</p><p><b>CONCLUSION</b>A variety of differentially expressed-miRNAs are existed between AML and normal control subjects CD34(+) cells, the expression of miR-10a and miR-220c was significantly down-regulated in the CD34(+) cells from the bone marrow of AML patients.</p>

Screening and structure analysis of nucleic acid aptamers binding to surface of CD33(+)/CD34(+) cells from patients with acute myeloid leukemia subtype M₂ / 中国实验血液学杂志

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.

Effect of diallyl disulfide on expression and secretion of VEGF in HL-60 leukemic cells / 中国实验血液学杂志

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.