Effects of Triptolide Combined with Homoharringtonine on Proliferation and Apoptosis of KG-1α Cells / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect and possible mechanism of low concentration of triptolide (TPL) combined with homoharringtonine (HHT) on the proliferation and apoptosis of KG-1α cells.</p><p><b>METHODS</b>CCK-8 method was used to detect the antiproliferating effects of different concentrations of TPL and HHT single-use and combined use on KG-1α cells, and the combined index (CI) was calculated. The colony formation ability was also determined by methylcellulose colony formation assay, cell surface molecules, apoptosis rate and cell cycle changes were detected by flow cytometry. Westerrn blot was used to detect the expression of Akt signaling pathway related proteins before and after low dose TPL combined with HHT using.</p><p><b>RESULTS</b>High expression of CD34 and CD123 were on KG-1a cells, which being lack expression of CD38. TPL and HHT dose-dependently inhibited the proliferation of KG-1α cells. Compared with low dosage TPL and HHT single-use groups, the cell proliferation and colony formation efficiency were lower, and the cell apoptosis rate was higher in the combined group. CI values also indicated that low concentration TPL combined with HHT possessed highly synergistic effect. After the combination of the 2 drugs, the expressions of P-Akt, P-Akt, BCL-2, PARP and survivin protein were down-regulated and the cleavage of PARP protein was increased.</p><p><b>CONCLUSION</b>Low concentration of TPL combined with HHT can synergistically inhibit KG-1α cell proliferation and induce its apoptosis through the PI3K/Akt signaling pathway and downstream protein.</p>

Reversing effects of emodin on multidrug resistance in resistant HL-60/ADR cells / 中国实验血液学杂志

This study was aimed to investigate the reversing effects of emodin on multidrug resistance (MDR) in resistant HL-60/ADR cells, and to explore the underlying mechanisms. The MTT assay was used to assess the chemoresistance of HL-60/ADR cells to emodin and 8 chemotherapeutic agents commonly used in clinic. The reversal effects of emodin on MDR of HL-60/ADR cells were also evaluated by MTT method. DNA ploidy analysis and DNA Ladder assay were used to detect apoptosis-induced effects on HL-60/ADR cells via the adriamycin (ADR) and emodin combination. The expression changes of the drug resistance-associated genes and proteins were detected by RT-PCR and Western Blot respectively. The intracellular accumulation and subcellular distribution of ADR and DNR were measured by flow cytometry and confocal laser scanning microscopy. The results showed that emodin inhibited HL-60/ADR cell proliferation with an average IC50 value of 24.09 ± 1.72 µmol/L, which was similar to that of the parental HL-60 cells (average IC50 = 23.18 ± 0.87 µmol/L). HL-60/ADR cells were resistant to a variety of chemotherapeutic agents, such as ADR, DNR, VP16, VCR,Ara-C, HHT, MTZ and THP. The reversal multiple were between 1.58 and 4.12 after the treatment with low concentration of emodin combined with the above mentioned different agents. The combination of ADR with emodin showed the best reversal effects, and the typical hypodiploid peak (apoptotic peak) and DNA ladder could be detected after the co-treatment.In addition, emodin down-regulated the mRNA and protein expression levels of MRP1, TOPOIIβ, GST π and BCL-2. Furthermore, the addition of emodin enhanced ADR and DNR intracellular accumulation and subcellular distribution in HL-60/ADR cells in dose-dependent manner. It is concluded that the emodin shows reversing effects on the multidrug resistant HL-60/ADR cells, possibly via decreasing the expression levels of drug resistance-associated genes, increasing the intracellular accumulation of chemotherapeutic agents and activating the apoptosis pathway.

A multicenter comparison study on the quantitative detection of bcr-abl (P210) transcript levels in China / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the comparability of bcr-abl (P210) transcript levels detected in different hospitals.</p><p><b>METHODS</b>Ten hospitals in China took part in the four times of sample exchange and comparisons from April, 2010 to August, 2011. The exchange samples were prepared by Peking University People's Hospital. Firstly, the BCR-ABL (P210)(+) cells from a newly diagnosed chronic myeloid leukemia patient were 10-fold serially diluted by BCR-ABL (P210)(-) cells and they covered 4 magnitudes. Then, TRIzol reagents were thoroughly mixed with cells in each tube. Every 12 samples (three samples per magnitude) were sent to the other 9 hospitals. The cell number of each sample was 8×10(6). The detection of bcr-abl transcript levels by real-time quantitative PCR were performed in every hospital according to their own protocols. Conversion factors (CF) were calculated using regression equation.</p><p><b>RESULTS</b>Differences in bcr-abl transcript levels did exist among results of 10 hospitals in each comparison. In general, the results of the most of hospitals were in line with the dilutions of cells. CF of every hospital fluctuated. Three hospitals had relatively stable CF, and their ranges were 2.8 - 5.2, 1.2 - 2.8 and 2.2 - 6.8, respectively; two hospitals had unstable CF with ranges 0.76 - 7.0 and 2.1 - 18.7; three hospitals couldn't be calculated CF one or two times because of the significant deviation of the results from the actually bcr-abl transcript levels, and their ranges of CF which could be calculated were 1.9 - 19.2, 3.6 - 7.6 and 0.18 - 14.7; One hospital only had two CF (3.3 and 5.0) because of the replacement of an important reagent during the period of comparisons.</p><p><b>CONCLUSIONS</b>Comparability of bcr-abl (P210) transcript levels between different hospitals could be achieved through CF which acquired by sample exchange and comparison. The stable and reliable detection system is the premise to acquire correct CF.</p>

Regulation of all-trans retinoic acid and arsenic trioxide on CD44v6 expression in NB4 cells / 中国实验血液学杂志

The adhesion molecule CD44 variant isoform (CD44v6) closely associates with progress of acute myeloid leukemia (AML). This study was purposed to investigate the effects of all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) on the expression of CD44v6 and the associated signal pathway phosphatidylinositol 3-kinase (PI3K)/Akt in acute promyelocytic leukemia (APL) cell line NB4 cells. The differentiation of NB4 was detected by morphologic observation and flow cytometry; the NB4 cell apoptosis was assayed by flow cytometry with Annexin V-FITC/PI double staining; the CD44v6 mRNA expression in NB4 cells was determined by real-time RT-PCR, the CD44v6 protein expression and changes of PI3K/Akt signal pathway in NB4 cells were analysed by Western blot. The results demonstrated that in ATRA-induced differentiation, the transcriptional level of CD44v6 was dominantly down-regulated, the translational level of CD44v6 did not change and the PI3K/Akt signal axis was activated. In As2O3-induced apoptosis, both the transcriptional level and translational level of CD44v6 were remarkably reduced, and the PI3K/Akt pathway was inhibited. It is concluded that the regulation of ATRA on expression of CD44v6 in NB4 cells differs from that of As2O3. The results provide an experimental basis to reveal the different mechanism of ATRA and As2O3 in view of the intercommunication between leukemia cells and hematopoietic microenvironment.

Direct contact with bone stromal HS-5 cells reduces the sensitivity of HEL to drugs / 中国实验血液学杂志

This study was proposed to investigate the sensitivity and resistence of HEL cells co-cultured with bone marrow stromal HS-5 cells to chemotherapeutic drugs. HEL cells were cultured in direct contact with HS-5 cells for 6, 12, and 24 h. Cell Counting Kit-8 (CCK-8) was used to determine the sensitivity of HEL cell to cytarabine, methotrexate, VP16, and daunomycin. Cell cycle distribution was determined by using flow cytometry. Real-time RT-PCR was performed to detect the transcription levels of p19, p21, p27, MDR1, ABCG2 and bcl-2. Western blot was performed to determine the protein levels of p-Akt(Ser473), p-glycogen synthase kinase 3β (p-GSK3β(Ser9)), p-signal transducer and activator of transcription (p-STAT3(Tyr705)), Bcl-2, cleaved-Notch1(V1754), and Hes1. The results showed that chemo-sensitivity of HEL cells was remarkably reduced when co-cultured with HS-5 cells. HEL cells were arrested in the G(0)/G(1) phase after co-culture for 24 h. Transcription of p21 was significantly up-regulated at 6 h. Transcription of p19 decreased at 12 h and returned to baseline at 24 h. No significant changes in the mRNA expression of other genes were found. The expressions of p-Akt(Ser473), p-GSK3β(Ser9), cleaved-Notch1(V1754) and Bcl-2 proteins were significantly up-regulated in HEL cells, and Hes1 protein was significantly down-regulated. There was no change in p-STAT3(Tyr705) expression. It is concluded that the direct contact with HS-5 cells can reduce the chemo-sensitivity of HEL cells.

Keratin 17 mutation in pachyonychia congenita type 2 in a Chinese Han family / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the keratin 17 gene (KRT17) mutation in a pedigree with pachyonychia congenita type 2 (PC-II).</p><p><b>METHODS</b>DNA was extracted from the blood samples of the patients, unaffected members of the pedigree, and 100 unrelated healthy controls. PCR was performed to amplify the hot spots in KRT17 gene. PCR products were directly sequenced to detect mutation.</p><p><b>RESULTS</b>A heterozygous 296T-->C mutation was found in all the affected members of this family, which resulted in the substitution of leucine by proline in codon 99 (L99P) in the 1A domain of the KRT17, but not in the healthy individuals from the family and the 100 unrelated controls.</p><p><b>CONCLUSION</b>The mutation of KRT17 may play a major role in the pathogenesis of this pedigree with pachyonychia congenita type 2.</p>

Effect of bcl-2 siRNA on apoptosis of Burkitt's lymphoma cell line CA46 / 中国实验血液学杂志

The aim of this study was to investigate the effect of bcl-2 siRNA on bcl-2 gene expression and apoptosis of lymphoma cell line CA46. A siRNA was designed and synthesized. Then siRNA was transfected into CA46 cells by cationic liposome. At 48 hours after transfection, apoptosis and mitochondria transmembrane potential of CA46 cells were detected by flow cytometry, the expression of bcl-2 mRNA and BCL-2 protein in CA46 cells were detected by RT-PCR and flow cytometry respectively. The results showed that at 48 hours after transfection, apoptosis of CA46 cells occurred, mitochondria transmembrane potential changed. The expression of bcl-2 mRNA and BCL-2 protein in CA46 cells decreased significantly. In conclusion, bcl-2 siRNA depresses the expression of bcl-2 gene in CA46 cells specifically, then changes the mitochondria transmembrane potential, resulting in apoptosis of CA46 cells.

Study on cytotoxic activities on human leukemia cell line HL-60 by flavonoids extracts of Scurrula parasitica from four different host trees / 中国中药杂志

<p><b>OBJECTIVE</b>To compare the anticancer effects of flavonoids extracts of Scurrula parasitica from different host trees in vitro.</p><p><b>METHOD</b>80% ethanol extracts of S. parasitica parasitizing on Nernium indicum, Morus alba, Opsmanthus fragrans, and Sapindus mulorossi were purified by polyamides column chromatography, and the eluates of 30%, 50%, 70% and 90% ethanol were mixed as flavonoids extracts. Human acute myeloid leukemia cell line HL-60 was used to evaluate the cytotoxicity induced by flavonoids extracts of S. parasitica L with MTT assay. Apoptosis was detected by AO/EB fluorescence staining and DNA fragmentation analysis, apoptosis rates and cell cycle distribution were detected by flow cytometry analysis.</p><p><b>RESULT</b>Extract of S. parasitica parasitizing on N. indicum (NISPEX) was the most sensitive to HL-60 cells of the 4 different host trees, the IC50 value being 0.60 mg x L(-1); and extract of S. parasitica parasitizing on M. alba took the second place, the IC50 value, being 2.49 mg x L(-1); extract of S. parasitica parasitizing on O. fragrans had no effectiveness as high as 50 mg x L(-1) concentration. NISPEX induced HL-60 cell apoptosis and inhibited the cell proliferation in dose and time-dependent manner. Cell cycles were arrested at G0-G1 phase after treated with NISPEX.</p><p><b>CONCLUSION</b>Anticancer effects of S. parasitica correlated with the host trees. Flavonoids extracts of S. parasitica parasitizing on N. indicum exhibited comparatively better anticancer activity in vitro among the host trees studied. NISPEX is found to be a good candidate for anticancer.</p>

A novel bcl-2 antisense oligodeoxynucleotide F951 increases sensitivity of HL-60 cells to Ara-C / 中国实验血液学杂志

To investigate whether F951, a novel bcl-2 antisense oligodeoxynucleotide, increases the sensitivity of HL-60 cells to Ara-C, HL-60 cells were cultured with F951 in different doses alone or with F951 combined with low-dose Ara-C; the proliferation of HL-60 cells was assayed by MTT and trypan blue exclusion test; expression of Bcl-2 protein and its mRNA were measured by FACS and RT-PCR, respectively; the apoptotic cells were detected by DNA ladder and TUNEL assay. The results showed that F951 combined with low dose Ara-C revealed stronger effects in the aspects of inhibiting the HL-60 cells proliferation than in different doses of F951 alone or Ara-C alone. HL-60 cells treated with F951 + Ara-C had significantly lower trypan blue exclusion rate than that treated with Ara-C alone. The inhibition rates of HL-60 cells treated with FNS, Ara-C, F951 and F951 + Ara-C were -2.8%, 27.63%, 37.66%, 57.24%, respectively. F951 significantly down-regulated the expression of bcl-2 mRNA and protein in HL-60 cells. HL-60 cells treated with F951 + Ara-C showed more apparent DNA ladder and more apoptotic cells. It is concluded that F951 can inhibit bcl-2 gene expression and enhance the cytotoxicity of Ara-C through promoting apoptosis in HL-60 cells, hence increases the antitumor effect of Ara-C.