Apoptosis effects of drug sensitivity leukemia cells induced by nano-realgar / 中国中药杂志

<p><b>OBJECTIVE</b>To explore apoptosis-inducing effects of realgar nanoparticle (nano-realgar) on drug-sensitive leukemia cells.</p><p><b>METHOD</b>Preparation of nano-realgar was mechanical milled using a high-energy planetary ball mill. Using drug-sensitive leukemia cells (K562) as target cells, MTT assay was used to detect the proliferating activity of K562 cells, and the cellular apoptosis was investigated with double staining of FITC-Annexin V and propidium iodide (PI) by flow cytometry. Flow cytometry (FCM) was employed to detect expression of intracellular Bax, Bcl-2, P-53 protein and the activity of Caspase-3.</p><p><b>RESULT</b>The raw realgar was made to ultra-fine powder by ball milling, and the average diameter of the nanoparticle was (72.72 +/- 22.18) nm measured with electron microscopes. Nano-realgar significantly inhibited the proliferation of K562 cells, Treated for 24, 48 and 72 hours, the 50% inhibitory concentration (IC50) was 43.48, 20.52, 16.07 mg x L(-1). After exposure to 20 mg x L(-1) and 50 mg x L(-1) nano-realgar for 48 hours, the apoptosis of K562 cells detected by Annexin V/PI staining was increased, the apoptotic rate of K562 cells was 10. 52% and 73.25%. After the target cells were treated with 20 mg x L(-1) and 50 mg x L(-1) nano-realgar for 48 h, the expression of P-53, Bax, Bcl-2 markedly increased in a time and dose-dependent manner. After administration of 20 mg x L(-1) and 50 mg x L(-1) nano-realgar for 48 h, the percentage of BCRP+, P-gp+ and co-expressing P-gp and BCRP cell population in K562 cells incrased dramatically.</p><p><b>CONCLUSION</b>Nano-Realgar significantly induced apoptosis of drug-sensitive leukemia cells.</p>

Genetic characterization of human parainfluenza virus 3 circulating in Gansu and Shaanxi Provinces from 2009 to 2011 / 病毒学报

To investigate the genetic characterization of Human parainfluenza virus-3 (HPIV-3) circulating in Gansu and Shaanxi Provinces of China, 719 throat swabs were collected from pediatric patients with acute respiratory infections from 2009-2011. Multiplex RT-PCR was used to screen common respiratory viral pathogens. For HPIV-3-positive specimens, nested RT-PCR was used to amplify the HN gene of HPIV-3. The nucleotides of Hemagglutinin-neuraminidase(HN)gene of 13 HPIV-3 positive strains identified in Gansu and Shaanxi Provinces were successfully sequenced and compared with those downloaded from GenBank. The phylogenetic analysis based on the nucleotides sequence of HN gene showed that 13 HPIV-3 strains belonged to sub-cluster C3 with little sequence variation (overall nucleotide divergence of 0.2%-2.3% and amino acid divergence at 0-1.1%). Compared with the complete gene of HPIV-3 strains from U.S.A., Canada, and Australia, the biggest divergence of the nucleotide and amino acid lovels was 6.0% and 3.4%, respectively. The nucleotide divergence between shaanxi09-2 and shaanxi10-H0091 was 0.9%, while the nucleotide divergence between shaanxi10-H005 and gansull-62110372 was 0.5%, between shaanxi09-2 and BJ/291/09 was 0.6%. However, there was no amino acid divergence among them. It is likely that HPIV-3 virus had been transmitting in Gansu and Shaanxi Provinces for several years. Human parainfluenza virus-3 (HPIV-3) circulated in Gansu and Shaanxi Provinces from 2009 to 2011 belonged to sub-cluster C3.

Effects of 5-bromotetrandrine and daunorubicin on apoptosis and expression of survivin in K562/A02 cells / 中国实验血液学杂志

The aim of this study was to investigate the potential benefit of combination therapy with 5-bromotetrandrine (5-BrTet) and daunorubicin (DNR) on chronic leukemia. The apoptosis of K562/A02 cells treated by DNA, BrTet and BrTet combined with DNR for 48 hours was detected by flow cytometry; the expressions levels of survivin mRNA and protein K562/A02 cells treated by DNR, BrTet and BrTet combined with DNR and in untreated K562 cells for 48 hours were measured by RT-PCR and Western blot respectively. The results showed that the combination of BrTet with DNR increased apoptotic rate of K562/A02, down-regulated the expression levels of survivin mRNA and protein in K562/A02 cells as compared with blank control and cells treated by BrTet or DNR alone, the survivin expression in K562/A02 cells was higher than that in K562 cells. It is concluded that the combination of BrTet with DNR can effectively reverse the multidrug resistance of K562/A02 cells, promote the apoptosis of K562/A02 cells, the mechanism of which may be related with down-regulation of survivin expression. Survivin may be a target for the treatment of MDR in hematopoietic malignancies.

siRNA silences mdr1 gene expression and reverses apoptosis resistance of K562/ADM cells line / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of small interfering RNA(siRNA) on silence of mdr1 gene and reversal of apoptosis resistance in multidrug-resistant (MDR) human leukemia K562/ADM cell.</p><p><b>METHODS</b>Human MDR leukemia cell line K562/ADM was used as the target cells. Two siRNAs (mdr1 siRNA-1 and mdr1 siRNA-2) targeted mdr1 gene were chemically synthesized and transfected into K562/ADM cells with liposome. Expression of mdr1 mRNA was determined by real-time PCR, P-glycoprotein (P-gp) expression and caspase-3 activity were measured with flow cytometry (FCM), and the cell apoptosis was observed by optical and electronic microscopy for morphology and Annexin V/PI staining.</p><p><b>RESULTS</b>The mdr1 siRNA-1 and mdr1 siRNA-2 could markedly down-regulate the expression of mdr1 gene in K562/ADM cells, the expression of mdr1 mRNA decreased by 91.2% and 82.0% , and the P-gp by 74.1% and 84.4%, respectively. The caspase-3 activity was markedly enhanced, and the active caspase-3 in K562/ADM cells increased by about 40% compared to liposome alone and non-silencing controls. the sensitivity of K562/ADM cells to adriamycin-induced apoptosis was significantly augmented, the apoptotic rate of the cells treated with siRNA plus adriamycin increased by about 60% compared to adriamycin alone.</p><p><b>CONCLUSION</b>siRNAs silence the expression of mdr1/P-gp to overcome the P-gp-mediated apoptosis resistance in drug-resistant K562/ADM cells.</p>

The analysis of HLA-A, B and DRB1 allelic polymorphism in Han race population in Lanzhou region of China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the HLA-A, B and DRB1 allele polymorphism of the Han race population in Lanzhou area.</p><p><b>METHODS</b>Polymerase chain reaction-sequence specific primer was used to detect HLA-A, B and DRB1 alleles in 200 unrelated healthy Han individuals from Lanzhou region, Northwest China, and the results were compared with those of Han populations in North, South and Northwest China, and Hui, Uigur and Tibetan population in China.</p><p><b>RESULTS</b>Fourteen of alleles were detected and identified for HLA-A; 32 for HLA-B; and 13 for HLA-DRB1. HLA- A*01, A*02,A*11,A*24, A*30, A*31, A*33; HLA- B*13, B*15, B*40, B*44, B*46, B*51, B*58, B*60; HLA- DRB1*04,. DRB1*07, DRB1*08, DRB1*09, DRB1*11, DRB1*12, DRB1*14 and DRB1*15 were the most common alleles. The frequencies of HLA-A, B and DRB1 genes of Lanzhou Han race were close to that of North China Hans and Hui population in Northwest China, and a little different to that of South China Hans. The HLA-DRB1 alleles were significantly different to those of Uigur and Tibetan race population of China.</p><p><b>CONCLUSION</b>The allelic polymorphism of HLA-A,B and DRB1 loci of Han race population in Lanzhou area was between North and South Han race of China, close to Northwest China Hui, and markedly different to Northwest China Uigur and Tibetan race populations.</p>

Creation and Characteristics of HepG2/mdr1 Cell Line / 中国生物工程杂志

Eukaryotic expression plasmid pCI-neo-mdr1 which contains human multidrug resistance gene 1(mdr1),was constructed and transferred into human hepatocarcinoma HepG2 cells by use of liposome. G418 was used to screen the cells successfully with mdr1 and the selected cells was named HepG2/mdr1 Morphological and biological properties of HepG2/mdr1 cells were observed. The results show that the constructed HepG2/mdr1 cell line was high efficient and stationary in the expression of mdr1. The work was valuable and desirable for the establishment of multidrug resistant cell models,and for the study of MDR in human hepatoma. Furthermore,the work also provided a perfect model for the research of relationship between insulin resistance and MDR in hepatocarcinoma cells.

Arsenic trioxide inhibits P-glycoprotein expression in multidrug-resistant human leukemia K562/ADM cell line that overexpresses mdr-1 gene and enhances their chemotherapeutic sensitivity / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effects of arsenic trioxide (As(2)O(3)) on the apoptosis and P-glyco-protein (P-gp) expression of multidrug-resistant human leukemia K562/ADM cells, and the combined effects of As(2)O(3) with conventional chemotherapeutic agents.</p><p><b>METHODS</b>Multidrug-resistant human leukemia cell line K562/ADM that overexpresses mdr-1 gene was used as the target cells. The cell proliferating activity was assessed with a MTT assay. Cell morphology was examined by light microscopy, confocal microscopy and electron-microscopy. P-gp expression, cell-cycle status were determined by flow cytometry.</p><p><b>RESULTS</b>K562/ADM cells were highly resistant to adriamycin, and cross-resistant to daunorubicin and etoposide. As(2)O(3) at concentrations of 0.5 to 20 micromol/L inhibited the proliferation of K562/ADM cells, and K562/ADM cells were more sensitive to As(2)O(3) than their parent K562 cells did. As(2)O(3) induced marked apoptosis of K562/ADM cells showed by typical apoptotic morphological changes and the appearance of high sub-G(1) cell population. As(2)O(3) significantly inhibited the P-gp expression in K562/ADM cells, and exerted a synergistic effect on the enhancement of the cell sensitivity to adriamycin, daunorubicin and etoposide.</p><p><b>CONCLUSION</b>As(2)O(3) induces growth-inhibition and apoptosis of multidrug-resistant K562/ADM cells, and augments synergistically the sensitivity of the cells to conventional chemotherapeutic agents via down-regulation of P-gp expression.</p>