Expression of IGLL1 Gene and Its Clinical Significance in Pediatric T-ALL / 中国实验血液学杂志

OBJECTIVE@#To detect the relative expression of IGLL1 (immunoglobulin lambda-like polypeptide 1) mRNA in bone marrow of children with T-cell acute lymphoblastic leukemia (T-ALL), and analyze its correlation with the clinical characteristics and prognosis of the patients, so as to clarify the clinical significance of IGLL1 in pediatric T-ALL patients.@*METHODS@#A total of 56 pediatric T-ALL patients hospitalized in Children's Hospital of Soochow University from June 2012 to December 2017 and treated with CCLG-ALL 2008 regimen were selected. Transcriptome sequencing technology was used to detect the transcription level of IGLL1 gene in children with T-ALL. According to 25% of the IGLL1 transcription level (cutoff value:448), the enrolled children were divided into IGLL1 low expression group (17 cases) and IGLL1 high expression group (39 cases). Combined with clinical data, the correlation between the expression level of IGLL1 and prognosis of the patients was analyzed.@*RESULTS@#The comparative analysis showed that the transcription level of IGLL1 was not correlated with the clinical characteristics of the patients, such as sex, age, bone marrow blast, white blood cell (WBC) count at initial diagnosis. The 5-year OS rate of patients with high IGLL1 expression was significantly higher than that of patients with low IGLL1 expression (76.9%±6.7% vs 47.1%±12.1%, P =0.018). Further comparison of relapse-free survival (RFS) rate between the two groups showed that the 5-year RFS rate of patients with high IGLL1 expression was higher than that of patients with low IGLL1 expression, but the difference between the two groups was not statistically significant (P =0.095). Multivariate COX analysis was conducted on common clinical prognostic factors (age, sex, WBC count at diagnosis, prednisone response on the 7th day, bone marrow response on the 15th day after treatment) and IGLL1 expression level, and the results showed that IGLL1 expression (P =0.012) and prednisone response (P =0.017) were independent risk factors for overall survival in pediatric T-ALL patients.@*CONCLUSION@#In pediatric T-ALL, the OS rate of children with high expression of IGLL1 gene was significantly higher than that of children with low expression of IGLL1 gene, and the expression level of IGLL1 gene was an independent factor affecting the survival of children with T-ALL, which suggests that IGLL1 is a marker of good clinical prognosis of children with T-ALL.

Analysis of Factors Influencing Overall Survival of MDS Patients Transplanted with HSCs / 中国实验血液学杂志

OBJECTIVE@#To analyze the effect of clinical features, routine laboratory examination and related gene mutation on the OS of patients with myelodysplastic syndrome (MDS) after hematopoietic stem cell transplantation (HSCT).@*METHODS@#121 patients diagnosed as MDS and underwent hematopoietic stem cell transplantation in the First Affiliated Hospital of Soochow University from October 2013 to August 2018 were selected. Basic information of the patients was collected, and blood cells, bone marrow blasts at initial diagnosis, chromosomal karyotypes and gene mutations of the patients were detected.The effect of different factors on overall survival (OS) was analyzed by statistical method.@*RESULTS@#Kaplan-Meier univariate analysis shows that OS was significanly different among different age groups. The 3-year OS rate of patients aged 0-29 years was (83.3±7.7) %, the 3-year OS rate in patients aged 30-49 years was (58.1±7.7 %), and the 3-year OS rate of patients aged 50-69 years was (31.0±22.6) %, which was statistically different (P＜0.05) between different groups. There were also significant differences in OS among patients with different transplantation types. 3-year OS rate: HLA-matched sibling HSCT＞unrelated HLA-matched HSCT＞haploidentical HSCT＞micro HSCT. The OS rate of patients with bone marrow blasts≥10% seems lower than blasts＜10%, but there was no statistical difference.The 3-year OS rate of patients with chromosomal karyotype complex abnormality was (47.7±11.5) %, and that of patients without complex abnormality was (80±4.2) % which was statistical difference (P＜0.05). Patients with DNMT3A, NRAS, TP53 and GATA2 mutations had shorter OS time compared with patients without mutation of these genes, which shows statistically significant (P＜0.05). COX multivariate analysis showed that age, chromosome karyotype, DNMT3A, TET2, GATA2 and NRAS were the independent factors influencing OS of patients after HSCT, with statistically significant difference.@*CONCLUSION@#age of patients, donor selection of HSCT, chromosome karyotype, DNMT3A, NRAS, TP53, GATA2 and TET2 gene mutations are all independent factors affecting the OS of patients after HSCT. Therefore, the assessment of the OS of MDS patients with transplantation requires comprehensive consideration.

Epigenetic Regulation and Epigenomic Landscape in Normal Physiological Hematopoiesis--Editorial / 中国实验血液学杂志

Abstract　　The physiological hematopoiesis depends on the programmed expression of a series of gene regulated by mechanisms at various levels. Currently, the epigenetic regulation has been considered as the most important mechanism during hematopoietic differentiation, resulting in a specific epigenomic landscape in the hematopoietic stem/progenitor cells. We try to concisely review the epigenetic mechanisms, including the genomic methylation, the histone modifications and the expression profiles of noncoding RNA, illustrating briefly the differentiation from the hematopoietic stem/progenitor cells to to the erythroid, myeloid and lymphoid cells.

Effect of AML1-ETO Fusion Protein on Transcriptional Regulation of p14 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of transcriptional regulation of aberrant transcription factor AML1-ETO on p14.</p><p><b>METHODS</b>P14expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. Methylation-specific polymerase chain reaction (MSP) was used to analyze the methylation status of p14promoter. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and p14promoter in AML1-ETO positive leukemia cell line. And the p14mRNA expression level was detected by qRT-PCR after treatment with 5-Aza.</p><p><b>RESULTS</b>AML1-ETO-expressing cell subclone displayed low level of p14mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, level of p14mRNA was markedly lower when compared with other acute myeloid leukemias lacking this translocation. P14gene promoter was non-methylated in control group and primary leukemia cells of AML patients without t(8;21) and was hyper-methylated in U937-A/E1-4 and primary leukemia cells of AML patients with t(8;21). The enriched regions in transfected cells were located within p14promoter. 5-Aza could increase the expression of p14.</p><p><b>CONCLUSION</b>P14is a possible target gene of AML1-ETO. The p14silencing induced by hyper-methlylation may be an important factor for occurrence and development of the Msubtype of acute myeloid leukemia.</p>

Autophagy Activity of CD34+ Cells in MDS Patients and Its Clinical Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the autophagy activity of CD34+ cells in bone marrow of MDS patients and its clinical significance.</p><p><b>METHODS</b>The activity of autophagy in bone marrow CD34+ cells from 20 MDS patients, 20 non-malignant anemia patients and 5 AML patients admitted in our hospital from October 2012 to March 2014 was detected by flow cytometry (FCM).</p><p><b>RESULTS</b>The autophagy activity in low risk MDS patients and non-malignant anemia patients were both significantly higher than that in both high risk MDS and AML patients (P<0.05), and more interestingly, the autophagy activity in MDS negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r=-0.877) .</p><p><b>CONCLUSION</b>The autophagy activity CD34+ cells in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores, indicating that the decrease of autophagy activity maybe accelerate the genesis and development of MDS and relate with the prognosis of MDS patients.</p>

Differentiation of K562 Cells Induced by Pulsatilla Saponin A into Erythroid Lineage / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the differentiation-inducing potentiality of Pulsatilla saponin A on K562 cells.</p><p><b>METHODS</b>Pulsatilla saponin A of different concentrations was used to treat K562 cells; the benzidine staining and the hemoglobinometry were applied to measure the change of hemoglobin content; the flow cytometry (FCM) was used to detect the expression of CD71 and GPA on K562 cells.</p><p><b>RESULTS</b>K562 cells treated with 4 µg/ml pulsatilla saponin A differentiated into the erythroid lineage. With the treatment of pulsatilla saponin A, the hemoglobin content in K562 cells increased significantly; CD71 and GPA expression on the K562 cell surface were up-regulated.</p><p><b>CONCLUSION</b>Pulsatilla saponin A can induce K562 cells to differentiate into erythroid lineage.</p>

Frequently ABL kinase domain G:C→A:T mutation and uracil DNA glycosylase abnormal expression in TKI-resistant acute lymphoblastic leukemia of Chinese population / 中国实验血液学杂志

Most Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) patients often show rapid recurrence and development of ABL kinase domain (KD) mutation after tyrosine kinase inhibitor (TKI) treatment. To further investigate the mechanism of Ph(+) ALL fast relapse after TKI treatment, ABL KD mutation in 35 Chinese Ph(+) ALL with TKI resistance was detected by direct sequencing. The results showed that 77.1% (27/35) Ph(+) ALL patients with TKI resistance had ABL KD mutation and 55.6% (15/27) Ph(+) ALL patients with ABL KD mutation had T315I. Interestingly, 77.8% (21/27) Ph(+)ALL showed ABL mutation G: C→A:T, including T315I, E255K and E459K. Furthermore, all the Ph(+) ALL patients with two or more ABL KD mutations collaborated with complex chromosome abnormality and all the TKI-resistant Ph(+) ALL patients, whose karyotype progressed from simple t (9;22) into complex, developed ABL KD mutation. Moreover, the expression level of uracil-DNA glycosylase UNG2, which inhibits G:C→A:T transition in genomic DNA, decreased in Ph(+) ALL with TKI-resistance compared to that in newly diagnosis Ph(+) ALL. It is concluded that there is a high frequent ABL KD G:C→A:T mutation and a high genomic instability in Chinese TKI-resistant Ph(+) ALL. In addition, the decreased UNG2 expression in TKI-resistant Ph(+) ALL probably contributes to their high rate of ABL KD G:C→A:T mutation.

Biocompatibility of polyethylene imine (PEI)-coated magnetic Fe₃O₄ nanoparticles in SHI-1 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of magnetic resonance cell imaging technology by using polyethylene imine (PEI)-coated magnetic nanoparticles of Fe₄O₄ (PEI-Fe₄O₄-MNPs) to track cell biology behavior.</p><p><b>METHODS</b>Endocytic PEI-Fe₄O₄-MNPs in SHI-1 cells were observed by transmission electron microscopy (TEM) . Iron contents of nano-labeled cells were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Prussian blue staining. The proliferation ability of labeled cells was detected by cell counting kit-8 (CCK-8) assay; the differentiation and colony-forming abilities were also observed. SHI-1 cells without endocytosing PEI-Fe₄O₄-MNPs were used as control.</p><p><b>RESULTS</b>Our data showed that PEI-Fe₄O₄-MNPs could label SHI-1 cells. The labeling efficiency depended on the nanoparticles' concentration and the duration of cells treating. Inhibition rates of SHI-1cells labeled by 60-100 μg Fe/ml PEI-Fe₄O₄-MNPs were much higher than of 5-50 μg Fe/ml ones following treating by 5-100 μg Fe/ml PEI-Fe₄O₄-MNPs for 48 hrs. The expressions of CD11b and CD14 were (78.4±18.5)% and (18.7±2.9)% in control vs (83.3±14.2)% and (20.4±2.1)% in cells fractions treated by 30 μg Fe/ml PEI-Fe₄O₄-MNPs. Clony-forming rates of SHI-1 cells labeled by 0, 20 , 50 μg Fe/ml PEI-Fe₄O₄-MNPs were (25.20±7.22)%, (25.93±13.15)%, (23.37±9.33)%, respectively. Differentiation and colony-forming potentials of labeled cells were similar with control in the certain range of PEI-Fe₄O₄-MNPs concentration.</p><p><b>CONCLUSION</b>SHI-1 cells were efficiently labeled by PEI-Fe₄O₄-MNPs with well biocompatibilities in proper range of concentration, the latter could be coupled with magnetic resonance imaging (MRI) to track cells in vivo.</p>

Direct contact with bone marrow stromal cells promotes the invasions of SHI-1 leukemia cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Interactions of tumor cells with the microenvironment were deemed to promote the tumor invasion and metastasis. CXC chemokine receptor 4 (CXCR4) and extracellular matrix metalloproteinase inducer (EMMPRIN) had reported to participate in this process. However the roles of bone marrow microenvironment in leukemic infiltration were not well investigated.</p><p><b>METHODS</b>A co-culture system between SHI-1 cells and bone marrow stromal cells (BMSCs) is used to simulate the interactions of leukemic cells with their microenvironment. The trans-matrigel invasion was used to detect the capability of SHI-1 cells invasion. The BMSCs and SHI-1 cells were mixed in a ratio of 1:10 and added to the millicell chamber coated with matrigel. Either the co-culture supernatant or the functional blocking peptide of CXCR4 and EMMPRIN were added to the trans-matrigel invasion system. The expressions of EMMPRIN in SHI-1 cells and BMSCs were detected by RT-PCR. The changes of the expression of matrix metalloproteinase-2, 9 (MMP-2, MMP-9), tissue inhibitor of metalloproteinase 2 (TIMP-2), and CXCR4 mRNA in SHI-1 cells were determined by real-time PCR. The concentration of stromal cell derived factor 1 (SDF-1) in serum free supernatant was measured by ELISA.</p><p><b>RESULTS</b>Both SHI-1 cells and BMSCs express EMMPRIN. SHI-1 cells could hardly invade the matrigel membrane; the coculture supernatant did not induce the invasion of SHI-1 cells. When contacting directly with BMSCs, SHI-1 cells invaded to the lower chamber of millicell were significantly increased. The functional blocking peptide of CXCR4 and EMMPRIN could significantly inhibit the invasion triggered by BMSCs. When co-culturing with BMSCs, the expression of CXCR4, MMP-2, MMP-9 and TIMP-2 mRNA in SHI-1 cells were significantly elevated in company with a significantly higher level of SDF-1 in the co-cultured serum-free supernatant.</p><p><b>CONCLUSION</b>The interactions of leukemic cells and BMSCs play important roles in leukemic cell infiltration.</p>

The different characteristics of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant Philadelphia chromosome-positive acute lymphoblastic leukemia and chronic myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To identify the distribution and differentiation of ABL kinase domain mutation in the Chinese Han nationality imatinib resistant chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+)ALL).</p><p><b>METHODS</b>Bone marrow or peripheral blood samples of 112 imatinib resistant CML patients and 21 Ph(+)ALL patients were obtained from the first affiliated hospital of Soochow university according to local law. Total RNA was extracted from the mononuclear cells using a TRIzol reagent. ABL kinase domain (KD) mutation was detected by direct sequencing.</p><p><b>RESULTS</b>Of the 112 imatinib resistant CML patients, 54.46%(61 cases) had ABL KD mutation. Twenty-three mutants were identified in 20 amino acid sites and 23.21% (26 cases) ABL KD mutations were in P-loop region. ABL KD mutations were also detected in 71.43% (15 cases) imatinib resistant Ph(+)ALL patients, with 10 mutations in 8 amino acid sites. The most frequent mutation was T315I (28.57%), followed by E255K/V (19.05%) and Y253F/H (14.29%). The frequency of T315I was much higher in imatinib resistant Ph(+) ALL than that in imatinib resistant CML (P = 0.001). Ph(+)ALL with additional chromosomal aberrations also had a higher rate of ABL KD mutation than that of CML (P = 0.010). Ph(+)ALL gained ABL KD mutation faster than CML (P < 0.010).</p><p><b>CONCLUSION</b>Chinese imatinib resistant CML and Ph(+)ALL patients had different characteristics in ABL KD mutation. The rate of ABL KD mutation in Ph(+)ALL with additional chromosomal aberrations was much higher than that of CML with additional chromosomal aberrations.</p>

The influence of CD44 on the adhesive, migratory and infiltrative abilities of leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of CD44 in leukemia cell lines and its role in adhesion, migration and infiltration of leukemia cells.</p><p><b>METHODS</b>The expression levels of CD44 in four leukemia cell lines SHI-1, THP-1, NB4 and K562 were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot when they were in logarithmic phase. And these cell lines were divided into control group (treated with same species and isotype IgG) and experimental group (treated with anti-CD44 mono-clonal antibody). The assays of cell-cell adhesion to endothelial cells line ECV304, migration through the artificial matrix membrane and infiltration through the Matrigel were performed.</p><p><b>RESULTS</b>The relative expression ratios of CD44 to GAPDH in SHI-1, THP-1, NB4 cells were 0.0731 ± 0.0072, 0.0827 ± 0.0151 and 0.1473 ± 0.0365, respectively, which were significantly higher than that in K562 cells (0.0002 ± 0.0000, P < 0.01). Cell-cell adhesion assay showed that the adhesion rates of SHI-1, THP-1 and NB4 cells in the experimental group decreased to 72.78%, 64.09% and 57.42%, respectively, and were lower than those of the control groups, while that of K562 cells in the experimental group was 106.16%. Migration assay showed that the transmembrane rates of SHI-1,THP-1 and NB4 cells were 55%, 29% and 25% in the control group, respectively, and decreased to 32%, 18% and 12% in the experimental group, respectively, while those of K562 cells in both control group and experimental group remained 2%. The infiltration rates of SHI-1, THP-1 and NB4 cells decreased from 24%, 15% and 13% in the control group to 12%, 8% and 4% in the experimental group, respectively, while K562 cells in both groups could not pass through the Matrigel.</p><p><b>CONCLUSION</b>CD44 antigen might play an important role in the adhesion, migration and infiltration of leukemia cells and be involved in the extra-medullary infiltration of leukemia cells.</p>

Transfection of HL-60 cells by Venus lentiviral vector / 中国实验血液学杂志

In order to study the potential of Venus, lentiviral vector, applied to acute myeloid leukemia, the recombinant vector Venus-C3aR was transfected into 293T packing cells by DNA-calcium phosphate coprecipitation. All virus stocks were collected and transfected into HL-60, the GFP expression in HL-60 cells was measured by flow cytometry. The expression level of C3aR1 in transfected HL-60 cells was identified by RT-PCR and flow cytometry. The lentiviral toxicity on HL-60 was measured by using CCK-8 method and the ability of cell differentiation was observed. The results indicated that the transfection efficacy of lentiviral vector on HL-60 cells was more than 95%, which meets the needs for further study. C3aR1 expression on HL-60 cells increased after being transfected with recombinant lentiviral vector. Before and after transfection, the proliferation and differentiation of cells were not changed much. It is concluded that the lentiviral vector showed a high efficacy to transfect AML cells and can be integrated in genome of HL-60 cells to realize the stable expression of interest gene. Meanwhile, lentiviral vector can not affect HL-60 cell ability to proliferate and differentiate.

Study of the clonal origin and development of MDS by FISH analysis of dysplasia cells in bone marrow of patients with MDS / 中国实验血液学杂志

This study was purpose to explore whether the dysplasia of myelodysplastic syndromes (MDS) is unspecific feature or results of the abnormal clone, and to provide the evaluation of abnormal clone changes in bone marrow cells of MDS patients. The dysplasia cells in bone marrow smears was analyzed by morphologic observation, the clonal origin and development in 16 cases of MDS with abnormality of chromosome karyotypes were investigated by FISH combined with morphologic observation. The results found that both the dysplastic and nondysplastic bone cells displayed abnormal clones in the erythroid and granulocytic cells. The dysplastic bone marrow cells displayed more abnormal clones than the nondysplastic bone marrow cells in most of the patients, and the abnormal clones displayed more dysplastic cells than the normal clones. Most of the dysplastic and nondysplastic megakaryocytes were derived from abnormal clones. The abnormal clone showed a decreasing trend from the primitive stage to the terminal stage of cell differentiation. It is concluded that there is a correlation between the dysplastic cells and the abnormal clones in MDS, but the dysplasia of bone marrow cells is not a specific feature. The abnormal clones can differentiate into mature granulocytes and erythrocytes, and can be in coexistence with cells originated from the normal clones.

Effect of AML1-ETO fusion protein on the expression of BCL-2 / 中国实验血液学杂志

This study was aimed to investigate the effect of AML1-ETO fusion protein on the anti-apoptotic gene BCL-2 in leukemic cells and to explore its role in leukemogenesis. The apoptotic levels of U937-WT, U937-Mock and U937-A/E1-4 cells were examined by flow cytometry. And cleaved caspase-3 protein expression was detected by Western blot. BCL-2 gene expression both in AML1-ETO-expressing cells or U937 nonexpressing cells and in leukemia cells of AML patients with or without t(8;21) was assessed by quantitative PCR. The chromatin immunoprecipitation (ChIP)-based PCR was used to investigate the direct interaction between the AML1-ETO and BCL-2 promoter in AML1-ETO positive leukemia cell line. The results indicated that in U937-A/E cells but not in U937-WT or U937-Mock cells, apoptotic cells statistically significantly increased, and AML1-ETO expression also significantly enhanced activation of caspase-3. AML1-ETO-expressing cell subclones displayed significantly low levels of BCL-2 mRNA in comparison with the non-transfected U937. In primary bone marrow cells of acute myeloid leukemia containing AML1-ETO, levels of BCL-2 mRNA were markedly lower as compared with other acute myeloid leukemias lacking this translocation. The enriched regions in transfected cells were located within BCL-2 promoter. It is concluded that BCL-2 is the direct target gene of AML1-ETO. AML1-ETO can down-regulate the expression of BCL-2.

Expression of autophagy related gene Beclin1 in myelodysplastic syndrome patients and its significance / 中国实验血液学杂志

This study was aimed to explore the contribution of autophagy associated gene Beclin1 in the prognosis of myelodysplastic syndrome (MDS) by detecting the expression level of Beclin1 in bone marrow mononuclear cells (BMNC) from 40 MDS patients, 14 non-malignant anemia patients and 25 AML patients. The expression of Beclin1 mRNA was detected by real-time quantitative polymerase chain reaction (qRT-PCR). At the same time, the Western blot was used to analyze the expression of Beclin1 proteins. The results showed that the expression of Beclin1 in low risk MDS patients and non-malignant anemia patients was both significantly higher than that in acute myeloid leukemia patients (P < 0.01). And more interestingly, the Beclin1 mRNA expression in MDS group was negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r = -0.495). It is concluded that the expression of Beclin1 in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores. Beclin1 is a potential biomarker for predicting prognosis of the patients with MDS.

Effect of IGFBP7 gene down-regulation on leukemia cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of down-regulation of insulin-like growth factor binding protein 7 (IGFBP7) on the proliferation and invasiveness of leukemia cell line U937 cells.</p><p><b>METHODS</b>Three pairs of double-strand siRNA targeting IGFBP7 gene were transfected into SMMC7721 cells to select the most efficient one for U937 cells. qRT-PCR and Western blot were used to detect the expression of IGFBP7 in U937 cells after transiently transfected with siRNA of IGFBP7. Cell proliferation, adhesion, trans-endothelial migration and invasion were performed in transfected cells and control groups.</p><p><b>RESULTS</b>After transfected with siRNA of IGFBP7 in U937 cells, the ability of cell proliferation was significantly decreased at 24 h (0.580 ± 0.159) compared to that of parental cells and scramble negative control (1.049 ± 0.274, 0.946 ± 0.195, respectively) (P < 0.01). Adhesion of U937 cells transfected with IGFBP7 gene specific siRNA to ECV304 cells was significantly lower than that of the control groups (0.247 ± 0.031 vs 0.406 ± 0.023 and 0.395 ± 0.011) (P < 0.01). Transendothelial membrane of U937 cells into the bottom of the 24-well plate for experimental group were less than those in the control groups \[(0.387 ± 0.021)×10(5) vs (1.017 ± 0.031)×10(5) and (0.908 ± 0.027)×10(5)\]. Cells adherent to the matrigel for experimental group were less than those in the control groups \[(0.197 ± 0.098)×10(5) vs (0.493 ± 0.067)×10(5) and (0.469 ± 0.083)×10(5)\]. The difference was significant (P < 0.01).</p><p><b>CONCLUSION</b>IGFBP7 gene plays a contributing role in leukemogenesis involving in leukemic cells' proliferation and interaction with endothelial cells through adhesion, invasion and migration.</p>

Significance of interplay between Rap1 and cadherin to the development of myelodysplastic syndrome / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the hematopoietic pathophysiology of myelodysplastic syndrome (MDS) at stem/progenitor cell level by analyzing the gene expression profiles associated with hematopoiesis.</p><p><b>METHODS</b>The differentially expressed genes which were involved in the hematopoiesis were screened by microarray using CD34(+) cells from MDS patients firstly. RQ-PCR was then applied to validate the screened genes using CD34(+) cells from MDS-RA patients who had normal karyotype. The linkages with hematopoiesis among these validated genes were analyzed.</p><p><b>RESULTS</b>Among the differentially expressed genes in CD34(+) cells of MDS-RA patients, Rap1GAP was up-regulated significantly (P < 0.01). Cadherins, which can interplay with Rap1, including N-cadherin and E-cadherin, were down-regulated significantly (P < 0.01). β-catenin, a downstream effector of cadherins, was highly expressed in MDS-RA patients (P < 0.01). c-myc binding protein was down-regulated (P < 0.01), and c-myc promoter binding protein was up-regulated (P < 0.01). Rac1, Rac2 and Cdc42, which belong to RhoGTPases family and are associated with the cell morphology and hematopoiesis, were all expressed highly in MDS-RA patients (P < 0.01).</p><p><b>CONCLUSION</b>The abnormal expression of cadherin, β-catenin and c-myc associated genes were closely related to the dysplastic hematopoiesis of MDS. The down regulation of cadherin was associated with the positive feedback mechanism between Rap1 and cadherin. The aberrant expression of Rac1, Rac2 and Cdc42 may contribute to the morphological dysplasia of MDS.</p>

Construction of venus vector carrying IGFBP7 gene and its expression in K562 cells / 中国实验血液学杂志

The aim of this study was to construct venus vector carrying the gene encoding insulin-like growth factor binding protein 7 (IGFBP7), which provides an effective platform for exploring the function of this gene in leukemia. After digestion by restriction endonuclease, the IGFBP7 gene was recombined with the transfer plasmid. The venus particles were packaged using 293T cells to transfect K562 cells, and identification was performed by means of flow cytometry, RT-PCR and Western blot. The results showed that the sequence of cloned IGFBP7 gene was the same as that in GenBank. The size of product restricted by BamHI was same as the predicted one. GFP expression was observed in 293T and K562 cells with the fluorescent microscopy and flow cytometry. The expression level of mRNA and protein of IGFBP7 was confirmed by RT-PCR and Western blotting in K562 cells. It is concluded that venus vector carrying IGFBP7 gene has been successfully constructed and provides basis for exploring function of IGFBP7 in K562 cells.

Effects of simvastatin on PI3K/AKT signaling pathway in human acute monocytic leukemia cell line SHI-1 / 中国实验血液学杂志

To investigate the effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor simvastatin (SV) on proliferation, apoptosis and the PI3K/AKT signaling pathway in human acute monocytic leukemia cell line SHI-1. SHI-1 cells were incubated with different concentrations of SV (5, 10, 15 µmol/L). Otherwise, SHI-1 cells without any treatment were used as control. Cells in different groups were collected at 24, 48 and 72 h after incubation for further detection. MTT method was used to assay the growth inhibition rate and flow cytometry was used to detect the early stage apoptosis ratio. The human PI3K-AKT Signaling Pathway RT(2) Profiler(TM) PCR Array was used to detect the expression of 84 genes involved in PI3K-AKT signaling. The results indicated that the SV inhibited the proliferation and inducted the apoptosis of SHI-1 cells in time- and dose-dependent manners significantly. The growth inhibition rates of SHI-1 cells treated with 15 µmol/L SV for 24, 48 and 72 h were 26.82, 47.09 and 63.92, respectively; and their early stage apoptosis ratios were 5.75, 13.25 and 15.59, respectively. Compared with the control group, expression levels of 39 genes were changed in the group of 15 µmol/L SV at 48 h, among them 26 genes were down-regulated and 13 genes were up-regulated. It is concluded that the SV can inhibit proliferation and induce apoptosis of SHI-1 cells, and the mechanism may be associated with the changes of gene expression level in PI3K-AKT signaling pathway regulated by SV.

Monitoring the expression ratio of AML1-ETO9a isoform in t(8;21) acute myeloid leukemia and its significance / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the expression ratio of AML1-ETO9a (AE9a) isoform in t(8;21) acute myeloid leukemia (AML) and its clinical significance.</p><p><b>METHODS</b>Bone marrow samples from 44 newly diagnosed t(8;21) AML patients co-expressed AE9a and AE were screened by RT-PCR. The alteration of the AE9a expression ratio was monitored during follow-up by using quantitative real-time RT-PCR (qPCR).</p><p><b>RESULTS</b>The expression level of AE9a was markedly lower than that of AE in these patients. There was a positive correlation between the expression level of AE9a and AE in most of bone marrow samples. The transcript level of both AE9a and AE was decreased in the 44 patients after one course of standard chemotherapy, but the percentage of AE9a expression level was increased in comparison with that before treatment (P < 0.05). After one course of standard chemotherapy treatment, the percentage of AE9a in incomplete remission (ICR) patients was significantly higher than that in CR patients (P < 0.05). Relapsed patients had a higher AE9a ratio than the unrelapsed patients (P < 0.05). During the remission, the percentage of AE9a in 11/17 relapsed patients obviously elevated even while the expression of AE fusion gene at low level.</p><p><b>CONCLUSIONS</b>AE9a and AE co-expressed in most of AML patients with t(8;21) translocation. The expression level of AE9a was lower than that of AE, and there is a positive correlation between the expression level of these two isoforms. The sensitivity of AE9a gene to the standard chemotherapy is less than that of the AE fusion gene. Monitoring the AE9a to AE ratio during the CR can predict the early relapse of the disease compared to monitoring the AE alone.</p>