Exploring the Mechanism of Paclitaxel Inhibiting T-cell Lymphoma based on High-throughput Sequencing and Public Databases / 中国实验血液学杂志

OBJECTIVE@#To analyze gene expression profile of T cell lymphoma Jurkat cell line treated with paclitaxel by computational biology based on next generation sequencing and to explore the possible molecular mechanism of paclitaxel resistance to T cell lymphoma at gene level.@*METHODS@#IC50 of paclitaxel on Jurkat cell line was determined by CCK-8 assay. Gene expression profile of Jurkat cells treated with paclitaxel was acquired by next generation sequencing technology. Gene microarray data related to human T cell lymphoma were screened from Gene Expression Omnibus (GEO) database (including 720 cases of T cell lymphoma and 153 cases of normal tissues). Combined with the sequencing data, differential expression genes (DEGs) were intersected and screened. DAVID database was used for enrichment analysis of GO function and KEGG pathway to determine and visualize functional entries of DEGs, and protein-protein interactions network of DEGs was drawn. The levels of gene expression were detected and verified by RT-qPCR.@*RESULTS@#CCK-8 results showed that the proliferation of Jurkat cells was inhibited by paclitaxel depended on the concentration apparently. Treated by paclitaxel for 48 h, P<0.05 and |log2(FC)|≥1 were used as filter criteria on the results of RNA Sequencing (RNA-Seq) and GeoChip, 351 DEGs were found from Jurkat cells, including 323 up-regulated genes and 28 down-regulated genes. The GO functional annotation and KEGG pathway enrichment analysis showed that the role of paclitaxel was mainly concentrated in protein heterodimerization activity, nucleosome assembly and transcriptional dysregulation in cancer, etc. The results of RT-qPCR were consistent with those of the sequencing analysis, which verified the reliability of this sequencing.@*CONCLUSION@#Paclitaxel can affect the proliferation and apoptosis of T-cell lymphoma by up-regulating JUN gene, orphan nuclear receptor NR4A family genes and histone family genes.

Effect of Mangiferin on Proliferation of FLT3-ITD Mutation Positive Acute Myeloid Leukemia Cell MV4-11 and Its Mechanism / 中国实验血液学杂志

OBJECTIVE@#To investigate the effects of mangiferin on proliferation, apoptosis and cycle of FLT3-ITD mutation-positive acute myeloid leukemia cells and its mechanism.@*METHODS@#The effects of different concentration of mangiferin on proliferation of MV4-11 cells were detected by CCK8 method. Apoptosis, cell cycle and FLT3 transmembrane protein expression were detected by flow cytometry. FLT3 mRNA expression was detected by real-time fluorescent quantitative polymerase chain reaction (PCR) .@*RESULTS@#Mangiferin obviously inhibited MV4-11 proliferation in a concentration and time dependent manner (48 h，r=0.922；72 h，r=0.959；96 h，r=0.973). The ratio of G0/G1 phase in cell cycle increased with the enhancement of concentration of mangiferin in MV4-11 cells for 48 h, and the ratio of S phase decreased with enhasment of concentration. The increase of apoptosis was more obvious. The expression of FLT3 transmembrane protein significantly decreased after the actior of IC50 concentration of mangiferin in MV4-11 cells for 48 h. The results of qRT-PCR showed that the expression of FLT3 mRNA significantly decreased after treatment of MN4-11 cells with mangiferin (P＜0.05).@*CONCLUSION@#Mangiferin inhibits MV4-11 cell proliferation, arrests cell cycle progression and promotes apoptosis, which may be related with the inhibition of FLT3 activity by mangiferin and the subsequent signaling pathways involved in apoptosis and proliferation of cells.

Promoter methylation and expression of death-associated protein kinase gene in acute leukemia / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the clinical implications of death-associated protein kinase (DAPK) promoter methylation and DAPK gene expression in untreated patients with acute leukemia.</p><p><b>METHODS</b>Methylation-specific PCR and RT-PCR were employed to detect the DAPK gene methylation and mRNA expression in the bone marrow of 60 patients with acute myeloid leukemia (AML), 55 patients with acute lymphocytic leukemia (ALL), and 17 normal subjects.</p><p><b>RESULTS</b>The positivity rate of DAPK methylation was significantly higher in ALL patients (29.1%) than in AML patients group (5%) and normal subjects (0%) (P<0.01). No correlation was found between DAPK gene methylation and the clinical features in ALL patients (P>0.05). DAPK mRNA expression level differed significantly among the 3 groups (P=0.000), and was the highest in normal subjects and the lowest in ALL patients. In ALL patients, the expression level of DAPK mRNA showed a significant inverse correlation with DAPK promoter methylation (P<0.05).</p><p><b>CONCLUSION</b>The methylation rate of DAPK gene is higher in untreated ALL patients than in AML patients and normal subjects. DAPK gene methylation is not correlated with the clinical features of ALL patients but is probably related with the low gene expression level of DAPK in these patients.</p>

Effect of DAPK overexpression on biological behaviors and caspase-3 expression in HL-60 cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of DAPK overexpression on the biological behaviors and caspase-3 expression in HL-60 cells.</p><p><b>METHODS</b>The expression of DAPK mRNA was detected by RT-PCR leukemia cell lines K562, Molt4, U937, and HL-60 cells. HL-60 cells were transfected by a eukaryotic expression vector pReceiver-M29-DAPK via LipofectamineTM 2000, and the impact of DAPK overexpression on cell apoptosis, cell cycle, cell differentiation and caspase-3 expression were analyzed.</p><p><b>RESULTS</b>DAPK mRNA expression was positive in K562, Molt4 and U937 cells but negative in HL-60 cells. Significantly increased cell apoptosis was observed in pReceiver-M29-DAPK-transfected HL-60 cells by flow cytometry and Hoechst33342 staining. The cell cycle distribution and differentiation showed no significant changes after the transfection. The expression of caspase-3 was significantly increased in the cells after transfection.</p><p><b>CONCLUSION</b>DAPK gene overexpression promotes apoptosis of HL-60 cells without affecting the cell cycle and differentiation. Caspase-3 may be involved in the regulation of cell apoptosis.</p>

Expression of miR-550a-5p in Myelodysplastic Syndrome and Its Prediction of Target Genes / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of miR-550a-5p in bone marrow of patients with myelodysplastic syndrome (MDS), and to predict its target genes and function by bioinformatics analyses, so as to provide the evidence to furthre explore the role of miR-550a-5p and its target genes in pathogenesis of MDS.</p><p><b>METHODS</b>Real-time PCR was used to detect the expression of miR-550a-5p in 54 MDS patients, 16 acute myeloid leukemia transformed from MDS (sfAML) and 19 healthy controls, and the correlation between the expression of miR-550a-5p and clinical pathologic characteristics of MDS, including chromosome, percentage of marrow blasts, absolute neutrophil count, platelet count and hemoglobin levels were analyzed. The sequence of miR-550 was searched in miRBase database. Target genes of miR-550a-5p were predicted by Microcosm,Miranda and Targetscan, and the predective results were collected, then the enrichment analyses of target gene function(GO) and signalling pathway(pathway of miR-550a-5p) were carried out by using gene ontology darabase and KEGG database.</p><p><b>RESULTS</b>The expression of miR-550a-5p in bone marrow of all MDS patients was higher than that in controls: the expression level of miR-550a-5p in low risk MDS and middl risk 1 MDS was 1.7 times of controls (P=1.23×10); the expression of miR-550a-5p in midde risk 2 MDS and high risk MDS was 1.9 times of controls (P=1.20×10); the expression of miR-550a-5p in tAML was 2.0 times of controls (P=5.61×10). The miR-550a-5p expression level was up-regulated gradually with the enhancement of disease risk of MDS, but there was no correlation between the expression level of miR-550a-5p and clinical pathologic characteristics of MDS(chromosome: Normal: 1.11±0.19, Abnormal:1.26±0.15, P>0.05; Percentage of Marrow Blasts: r=0.29,P=0.07; absolute neutrophil count: r=-0.02,P=0.89; hemoglobin level: r=0.09,P=0.57; platelet count: r=0.25,P=0.08). The sequence of miR-550 was conservative among different species, and the prediced results indicated that there were 19 target genes in intersection. The functions of target genes were enriched in regulation of stress-activated cascade, MAPK pathway, regulation of muscle organ development, regulation of protein homodimerization activity and other biological processes; they participated in some molecular functions including enzyme activity, combination processes of some molecules as protein, cAMP and domain existed in cell junction, synapse, coated vesicle, dendrite and other cellular components. Two of them-PDLIM2 and PSME1 were selected which might play a role in pathologic mechanism of MDS regulated by miR-550a-5p.</p><p><b>CONCLUSION</b>The expression of miR-550a-5p in bone marrow of MDS patients increases specifically, and miR-550a-5p may play a role in the pathogenesis of MDS through regulation of target genes, PDLIM2 and PSME1.</p>

Developing a system to promote good prenatal and postnatal care, and good preschool education based on the cellphone platform / 中国医疗器械杂志

Good prenatal and postnatal care and good preschool education are important approaches to raise the diatheses of population for the chinese nation. This article suggests that the cell phone platform can be used to communicate with each other among the hospitals, the government and the common people, through which the useful informations could be transmitted to the relative persons in time. It's also a new way for propaganda of family planning. This article introduces the structure of the system, the creation of the expert database, and the connection to the telecommunication system.

Gene of DNA-dependent protein kinase catalylic subunit in chronic myeloid leukemia / 中国实验血液学杂志

This study was aimed to investigate the expression and regulation mechanism of DNA-dependent protein kinase catalylic subunit (DNA-PKcs) in chronic myeloid leukemia (CML) and its role in blast crisis of CML. Expression of DNA-PKcs mRNA was detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and DNA-PKcs protein by Western blot in 62 CML patients and K562, as compared to those of 23 normal individual controls. In 26 CML patients received allogeneic peripheral blood stem cell transplantation (allo-PBSCT) and 4 CML patients treated with imatinib, the expression of bcr-abl mRNA and DNA-PKcs protein was detected by RT-PCR and Western blot, respectively. After treatment with imatinib in mononuclear cell (MNC) of CML patients and K562 in vitro, expression of DNA-PKcs mRNA was detected by RT-PCR and DNA-PKcs protein level, tyrosine phosphorylation of bcr-abl fusion protein were detected by Western blot. The results showed that the expression of DNA-PKcs protein was significantly lower in CML and K562 than those in normal control (P<0.05). In 26 CML patients received allo-PBSCT and 4 CML patients treated with imatinib, the expression of DNA-PKcs protein was enhanced while the expression of bcr-abl mRNA decreased. After treatment of MNC of CML and K562 with imatinib in vitro, the expression of DNA-PKcs protein was enhanced while tyrosine phosphorylation of bcr-abl fusion protein decreased. It is concluded that the expression of DNA-PKcs protein is down-regulate by bcr-abl fusion gene, and the bcr-abl fusion gene down-regulate the expression of DNA-PKcs protein by post-transcriptional mechanism; the decrease of DNA-PKcs protein expression may be one of mechanisms underlying the acute transformation of CML.

Study on mismatch repair genes of chronic myeloid leukemia / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression and regulation mechanism of mismatch repair (MMR) genes in chronic myeloid leukemia (CML).</p><p><b>METHODS</b>Expression of MMR genes hMSH2, hMSH3, hMSH6, hMLH1 and hPMS2 mRNAs in 62 CML patients and K562 cell line were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Expression of bcr-abl mRNA and MMR genes mRNA were detected by RT-PCR in 26 CML patients with allogeneic peripheral blood stem cell transplantation (allo-PBSCT) and 4 CML patients on imatinib treatment. Expression of bcr-abl mRNA was detected by RT-PCR and tyrosine phosphorylation of BCR-ABL fusion protein by Western blot.</p><p><b>RESULTS</b>Expression of hMSH2, hMSH3 and hMLH1 mRNA was significantly lower in CML and K562 cells than in normal control (P < 0.05). In 26 CML with allo-PBSCT and 4 CML patients on imatinib treatment, expressions of hMSH2, hMSH3 and hMLH1 mRNA was enhanced while expression of bcr-abl mRNA decreased. In CML MNC after imatinib treatment and in K562 cells, expression of hMSH2, hMSH3 and hMLH1 mRNA was enhanced while tyrosine phosphorylation of BCR-ABL fusion protein decreased.</p><p><b>CONCLUSION</b>Expressions of hMSH2, hMSH3 and hMLH1 mRNA were down-regulated by bcr-abl fusion gene.</p>

CML cell line K562 cell apoptosis induced by mangiferin / 中国实验血液学杂志

This study was aimed to investigate the effects and the mechanism of mangiferin on chronic myeloid leukemia cell lines K562 cells in vitro. The antiproliferation effects of mangiferin on K562 leukemia cells were tested by tetrazolium salt (MTT) method; the apoptosis induced by mangiferin on K562 cell line was explored by means of cell morphology, DNA gel electrophoresis and flow cytometry. The changes in bcr/abl gene expression was detected by using reverse transcriptase (RT)-PCR. The results showed that five different concentrations of mangiferin (25 - 200 micromol/L) dose-dependently and time-dependently inhibited the proliferation of K562 cells, and induced apoptosis in K562 cell line. RT-PCR revealed that bcr/abl gene expression was down-regulated when K562 cells had been treated with different concentrations of mangiferin. In conclusion, mangiferin remarkably inhibits the proliferation of K562 leukemia cells in vitro, and induces apoptosis in K562 cell line probably through down-regulation of bcr/abl gene expression.