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.

Expression of DNA-dependent protein kinase catalytic subunit in adult acute leukemia and its significance / 中国实验血液学杂志

This study was aimed to explore the expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) in adult acute leukemia and its correlation with clinical characteristics, karyotype and prognosis. Indirect immunofluorescent cytometry was used to detect the expression of DNA-PKcs in bone marrow mononuclear cells of 105 patients with acute leukemia before chemotherapy and 41 of them after 2 cycles of chemotherapy. Cytogenetic data were obtained from 26 of them by R band karyotypic analysis. The results showed that the expression of DNA-PKcs was correlated with higher WBC count level in peripheral blood (p < 0.05), but was not obviously associated with median age, gender, percentage of bone marrow blasts, clinical classification, median hemoglobin level and median platelet count (p > 0.05). The middle and strong positive expression of DNA-Pkcs in non-remission group was significantly higher than that in remission group (p < 0.05). The positive rate of DNA-PKcs in abnormal chromosome group was significantly higher than that in chromosome normal group (p < 0.05). It is concluded that the DNA-PKcs expression level is closely related with the increased WBC count, and the expression of DNA-PKcs is correlated also with karyotype and clinical prognosis in adult acute leukemia.

Expression of angiotensin-II type 1 receptor at1 mRNA in myeloid leukemia / 中国实验血液学杂志

This study was aimed to explore the expression level of angiotensin-II type 1 receptor (AT1) mRNA in bone marrow of myeloid leukemic patients, and its correlation with the proportion of leukemia cells in samples and Hb, WBC, Plt counting in peripheral blood. 51 samples, including 36 AML, 7 CML, and 8 samples of non-malignant hematological diseases as control group were collected. The expression of at1 mRNA was detected by real time-PCR; the expression levels of at1 gene in AML and CML groups were relatively quantitatively analyzed by using 2(-ΔΔCT) and were compared with control group. The results showed that the expression levels of at1 mRNA in AML, CML and control groups were 0.038 ± 0.076, 0.033 ± 0.039, 0.281 ± 0.366, respectively. at1 gene expression in the myeloid leukemic group was significantly lower than that in the control group. The expression level of at1 mRNA in AML was negatively correlated with the proportion of leukemia cells and positively with Hb level in peripheral blood. It is concluded that at1 gene may play a minor role in leukaemogenesis, however, may promote erythropoiesis.

Effect of acetyl-11-keto-β-boswellic acid on proliferation, apoptosis and cell cycle of human acute myeloid leukemia cell line HL-60 / 中国实验血液学杂志

The aim of this study was to investigate the effect of 3-O-acetyl-11-keto-β-boswellic acid (AKBA) on the proliferation, apoptosis and cell cycle of human acute myeloid leukemia (AML) cell line HL-60. HL-60 cells were treated by AKBA at various concentrations. The inhibitory effects of AKBA on the proliferation of HL-60 were analyzed by MTT assay. Morphologic changes of HL-60 cells were observed by fluorescence microscopy with Hochest33342 staining. Cell apoptosis rate was determined by flow cytometry with Annexin-V-FITC/PI double staining. The cell cycle was measured by flow cytometry with PI staining. The results showed that AKBA inhibited the proliferation of HL-60 and the apoptosis rate of HL-60 cells was gradually enhanced when AKBA dose increased. AKBA changed the cell cycle of HL-60, resulting in cell increase at G(1) phase and decrease at S phase. It is concluded that the AKBA has anti-proliferation and apoptosis-inducing effects on HL-60 cells, that seems a promising therapeutical approach for AML.

Apoptosis of Burkitt's lymphoma Raji cell line induced by bortezomib / 中国实验血液学杂志

The aim of this study was to clarify whether bortezomib might induce apoptosis in Burkitt's lymphoma Raji cell line and its mechanism. Different concentrations of bortezomib were used to treat Raji cells and its effects of time and dose were observed. Cell morphology was observed under light microscope; flow cytometry was used to analyze cell apoptosis; RT-PCR was used to detect the expressions of NF-kappaB and p53 gene mRNAs. The results showed that the bortezomib could inhibit Raji cell growth within a certain range of treating time and dose. Apoptosis were induced in relation to time and dose. The expression of NF-kappaB mRNA and p53 mRNA decreased after treatment with bortezomib. It is concluded that the bortezomib can induce Raji cell apoptosis, which provides a theoretical basis for clinical treatment. NF-kappaB and p53 gene are supposed to participate in the bortezomib induced apoptosis of Raji cells.

Renin angiotensin system in bone marrow of patients with aplastic anemia / 中国实验血液学杂志

Renin-angiotensin system (RAS) has been shown to be involved in the growth, production, proliferation and differentiation of the bone marrow (BM) hematopoietic cells, while aplastic anemia (AA) is a disease in which proliferation ability of the BM hematopoietic cells is damaged with defective hematopoietic microenvironment. To investigated the pathogenesis of AA, the rennin activity, angiotensin I (Ang I) and angiotensin II (Ang II) concentration in peripheral blood and BM of 22 AA patients were detected by radioimmunoassay, 16 nonhematological disease patients with normal blood counts and BM picture were used as control, and the difference between two groups was compared. The results showed that BM Ang II concentration in the AA patients was significantly lower than that in the control (P < 0.01). In nonhematological disease patients, Ang II concentration in BM was significantly higher than that in peripheral blood, the renin activities and Ang I concentrations were not significantly different in the two groups (P > 0.05). In conclusion, the decreased BM Ang II concentration in AA patients may be involved to the pathogenesis of AA.

Study on platelet-associated tissue factor and its significance / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore whether normal platelet contains tissue factor (TF), and the significance of platelet-associated TF (PATF).</p><p><b>METHODS</b>Platelets were isolated by Sepharose 2B gel column. ELISA was used to detect the TF content in the lysates of washed platelets. Procoagulant activity of PATF was measured by one stage clotting time assay. The mRNA of TF was detected by reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>A certain amount of TF antigen (16.37 +/- 6.39) ng/L was detected in the washed-platelet lysates. Upon activation by collagen, platelets released TF and caused a marked increase in TF level in plasma (P <0.05). Resting platelets had no TF procoagulant activity, while procoagulant activity of platelets activated by collagen increased significantly, which could be blocked by TF McAb and poor VII plasma. TF mRNA could not be detected in washed platelets. TF content in platelets from patients with coronary heart disease was significantly higher than that from normal controls (P < 0.05). Resting platelets from the patients showed a higher procoagulant activity, which could be inhibited by TF McAb.</p><p><b>CONCLUSION</b>Platelets contain TF and the latter released by activated platelet was functionally active. Platelet itself might not synthesize TF. Protein content and procoagulant activity of PATF in patients with coronary heart disease were higher than that in controls. All these indicate that platelet may be involved in coagulation and thrombosis by releasing TF.</p>