Study of mifepristone on reversing multidrug resistance of leukemic cell line K562/A02 / 中华血液学杂志

<p><b>OBJECTIVE</b>To study whether progestogen antagonist mifepristone could reverse multidrug resistance of K562/A02 cells and its mechanisms.</p><p><b>METHODS</b>MTT was used to study the proliferation of K562/A02 cells and sensitivity of K562/A02 cells to ADM after 72 hours treatment with mifepristone. Flow cytometry was used to assay the expression of P-glycoprotein and the mean fluorescent intensity of intracellular daunorubicin. The expressions of apoptosis related proteins (bcl-2, Bax and caspase-3) were assayed by immunohistochemistry and the glucosylceramide synthase mRNA expression by RT-PCR before and after mifepristone treatment.</p><p><b>RESULTS</b>MTT assay revealed that 2.5, 5.0 and 10 micromol/L mifepristone did not affect the proliferation of K562/A02 cells, but enhanced the sensitivity of K562/A02 cells to ADM, by 1. 68-, 4.17- and 10.71- fold increase, respectively. Expression of P-gp in K562/A02 cells was (49.03 +/- 5.32)%, and was decreased to (28.60 +/- 2.13)% (P < 0.01) after 10 micromol/L mifepristone treatment for 72 hours. and intracellular DNR accumulation in K562/A02 was (61.07 +/- 8.61)%, and was increased to (92.72 +/- 3.48)% (P < 0.01). After 10 micromol/L mifepristone treatment, the expression of bcl-2 protein was decreased from (56 +/- 9)% to (37 +/- 6)% (P < 0.05), Bax and caspase-3 proteins was increased from (40 +/- 5)% to (87 +/- 10)% (P < 0.01), and from (36 +/- 7)% to (89 +/- 6)% (P < 0.01) respectively. RT-PCR analysis revealed that expression of glucosylceramide synthase mRNA was higher in K562/A02 than in K562 cells, whereas 10 micromol/L mifepristone significantly down-regulated its expression in K562/A02 cells.</p><p><b>CONCLUSION</b>Mifepristone at 10 micromol/L could dose-dependently reverse the multidrug resistance of K562/A02 cells. The possible mechanisms are related with decreasing the expression of P-gp, regulating the expression of apoptosis related proteins and decreasing the expression of glucosylceramide synthase.</p>

Improvement effect of bacterium derived oligonucleotides on maturation of K562/A02 cells derived dendritic cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the maturation effect of CpG2006 and phosphodiester oligonucleotides on leukemia-derived dendritic cells.</p><p><b>METHODS</b>Leukemia cells K562/A02 were induced into dendritic cells by rhGM-CSF and rhIL-4. After 7 days induction, the cell-morphology was observed, the immunophenotype of cells was detected by flow cytometry and the cell function was evaluated by allogeneic mixed lymphocyte reactions, CTL responses and secretion of IL-12 and IL-6. Then a CpG oligonucleotide CpG2006, two synthetic bacterial phosphodiester oligonucleotides A-ODN and T-ODN were added to these leukemia-derived DCs. Three days later, the DCs were re-detected by the above-mentioned methods.</p><p><b>RESULTS</b>After induced by CpG2006, A-ODN or T-ODN, the leukemia-derived DCs with typical dendritic morphology were increased. The expressions of CD83, HLA-DR and CD86 were (65.5 +/- 8.4)%, (32.0 +/- 4.3)% and (18.6 +/- 3.2)% respectively in day 7 leukemia-derived DCs, raised to (88.9 +/- 3.6)%, (53.9 +/- 3.2)% and (39.9 +/- 7.3)% respectively after exposing CpG2006 for 3 days; increased to (97.0 +/- 5.3)%, (63.9 +/- 7.3)% and (40.2 +/- 7.4)% respectively after treated by A-ODN; and further increased to (93.26 +/- 4.65)%, (58.3 +/- 5.6)% and (36.2 +/- 6.8)% respectively after treated by T-ODN. These results was markedly different than unaffected cells did. These DCs induced by the above-mentioned three oligonucleotides could upregulate significantly the capacity for stimulating allogeneic T cells. They could also induce CTL to generate specific cytotoxic activity against K562/A02 cells. The secretion of IL-6 and IL-12 was increased remarkably.</p><p><b>CONCLUSION</b>CpG2006, as well as two phosphodiester oligonucleotides can induce leukemia-derived DCs maturation.</p>

Study of antileukemic effect of CpG-oligodeoxynucleotides treated cord blood / 中华血液学杂志

<p><b>OBJECTIVE</b>To observe the antileukemic effect of lymphocytes from cord blood treated by CpG-oligodeoxynucleotides (CpG-ODN).</p><p><b>METHODS</b>Lymphocytes from cord blood were exposed to different oligodeoxynucleotides containing a panel of CpG-ODN and were cultured with K562 cells. The cytotoxic effects were detected by MTT method. Immunological markers of cord blood treated by CpG-ODN(3) which showed highest activity were measured with flow cytometry.</p><p><b>RESULTS</b>Different CpG-motifs have different immunostimulatory activity and CpG-ODN(3) has the highest one. After treated by CpG-ODN(3), NK killing activity to K562 cells increased in a dose-dependent manner, and CD(3), CD(4), CD(19) and CD(56) increased to (60.6 +/- 7.9)%, (40.2 +/- 3.5)%, (22.4 +/- 1.9)% and (15.5 +/- 3.1)%, respectively.</p><p><b>CONCLUSION</b>CpG-ODN could reinforces the immunological competence of cord blood lymphocytes and their effects on K562 cells. This provides a new approach to reinforce the antitumor effects of cord blood.</p>

The construction of SCID-Hu IC mice model and application in rAd5HPV16L1-E7 vaccine / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct human-SCID chimeric mice through implantation of mononuclear cells from human cord blood and study the immunoreaction of SCID-Hu IC mice immunized with rAd5HPV16L1-E7 vaccine.</p><p><b>METHODS</b>(1) Experiment groups were injected with the suspension of mononuclear cells from human cord blood through a tail vein; the control ones were injected with non serum RPMI 1640 medium. Eight weeks after implantation, blood was collected and human serum IgG level in the mice were tested, and human CD45, CD3 and CD19 were determined. (2) SCID-Hu IC mice were divided into two groups: in group A the mice were immunized intraperitoneally with rAd5HPV16L1-E7 virus and in group B the mice were immunized through nasal drip with rAd5HPV16L1-E7 virus. At the end of fourth week, the serum specific IgG antibody to rAd5HPV16L1-E7 virus, IFN-gamma in culture medium of spleen lymphocyte and T-lymphocyte propagation were tested.</p><p><b>RESULTS</b>(1) In the experiment groups, the number of mice positive for human IgG was 10/15, the average values of CD45, CD3 and CD19 were (9.39+/-4.21), (3.25+/-3.99) and (1.69+/-0.75), respectively. In the control ones, the human IgG, CD45, CD3 and CD19 were negative. (2) The results in the experiment groups showed that the IFN-gamma and T-lymphocyte stimulated by HPV16 protein were higher than those in the non-stimulated group (P less than 0.05).</p><p><b>CONCLUSION</b>(1) The results indicated that the construction of human-SCID chimaera through the implantation of mononuclear cells from human cord blood into SCID mice was successful. They also indicated that the reconstructed SCID-Hu IC mice has the ability to produce immune response against rAd5HPV16L1-E7 recombinant virus.</p>

Relation between helicobacter pylori L-form infection and tumor angiogenesis in human esophageal carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation between helicobacter pylori L-form (Hp-L) infection in human esophageal carcinoma (EC) and tumor angiogenesis, and study the effect of Hp-L on the malignant biological behaviors of EC.</p><p><b>METHODS</b>Hp-L was examined in 98 patients with EC and 30 controls by Gram stain, electronmicroscopic technique and immunohistochemical stain (ABC method). VEGF, p53 protein and microvessel density (MVD) were examined by immunohistochemical stain (SP method) with their relationship with the clinicopathologic factors analyzed.</p><p><b>RESULTS</b>The positive rate of Hp-L was 60.2% in EC group. Two types of Hp-L were detected in the tissue of EC by electronmicroscopic technique, which lay in the outer or inner carcinoma cells. The positive rates of Hp-L, MVD, VEGF and p53 in the cancer group were significantly higher than those in control group (P < 0.005-0.001). The positive rates of MVD, VEGF and p53 in the Hp-L positive group of EC were significantly higher than those in Hp-L negative group (P < 0.005-0.001). The positive rate of Hp-L was correlated with MVD (r = 0.46, P < 0.01) and the expression of VEGF and p53 (r = 0.31, P < 0.01). The positive rate of Hp-L in the EC group was correlated with vessel invasion, depth of invasion, metastasis to the para-esophageal and distant lymph nodes except tumor size.</p><p><b>CONCLUSION</b>Hp-L infection in EC is closely related with tumor angiogenesis and may be an important promoting factor in esophageal carcinoma growth, invasion and metastasis.</p>

Comparative proteomics research of apoptosis initiation induced by homoharringtonine in HL-60 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To study the related proteins of apoptosis initiation induced by homoharringtonine (HHT) in HL-60 cells.</p><p><b>METHODS</b>After establishment of an apoptosis initiation model induced by HHT in HL-60 cells, proteins of untreated and HHT treated HL-60 cells were extracted, and the two-dimensional polyacrylamide gel electrophoresis (2-DE) maps of the extracted proteins were established by using the immobilized pH gradient (IPG) two-dimensional electrophoresis respectively. The alteration protein spots were identified with assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and database searching.</p><p><b>RESULTS</b>Proteomics analysis showed that proteins including MHC class I antigen, calbindin D-28K, chloride channel protein 6, oncoprotein 18, zinc finger protein Helios and apoptosis inhibitor like protein 2 were involved in apoptosis initiation induced by HHT.</p><p><b>CONCLUSION</b>The present study might conduce to the researches of HL-60 cells carcinogenesis and pave the way to exploit drug precursor related to HHT and initiation of apoptosis in HL-60 cells.</p>