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  • Yuan, Peng  (11)
  • Medizin  (11)
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  • Medizin  (11)
RVK
  • 1
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5058-5058
    Kurzfassung: Objective: To establish the xenograft leukemia model with stable multiple drug resistance in nude mice; to investigate the reversal effect of 5-Bromotetrandrine and Magnetic nanoparticle of Fe3O4 combined with DNR in vivo and to search for the possible reversal mechanisms. Methods: K562 and K562/A02 cells were respectively inoculated subcutaneously into back of athymic nude mice (1×107 cells/each) to establish the xenograft models. The tumor formation was evaluated by animal ultrasonic inspection. Tumors-bearing nude mice were assigned randomly to five groups which were treated with NS (A group); DNR 1mg/kg (B group); nanoparticle of Fe3O4 combined with DNR 0.63mg/kg(C group): 5-BrTet 2.5mg/kg combined with DNR(D group); 5-Bromotetrandrine 2.5mg/kg and Magnetic nanoparticle of Fe3O4 combined with DNR 0.63mg/kg(E group) respectively. The incidence of tumor formation, growth characteristics, weight and volume of tumor were observed. The histopathologic examination of tumors and organs were detected. For resistant tumors, the protein levels of P-glycoprotein (P-gp) were detected by Western blot. Results: The tumor incidence was 100% in the nude mice inoculated with either K562 or K562/A02 cells. In 6 to 9 days,the tumors reached a volume of more than 1 00 mm3. In vivo, MTT assay showed K562/A02 tumor maintained the drug resistance. For K562 cells xenograft tumors, there were no apparent differences in tumor suppression effect between the B AC AD AE group. For K562/A02 cells xenograft tumors, 5-BrTet and Magnetic nanoparticle of Fe3O4 combined with DNR significantly suppressed growth of tumor: the inhibition rate was 62.76% while DNR alone be used, the inhibition rate was 3.68%. Pathologic examination of resistant tumors showed the tumors necrosis obviously in E group. Application of 5-BrTet and Magnetic nanoparticle of Fe3O4 inhibited the overexpression of P-gp. Conclusion: The xenograft leukemia nude mice model was maintain the multiple drug resistance. 5-Bromotetrandrine and Magnetic nanoparticle of Fe3O4 combined with DNR had a significant tumor-suppressing effect on MDR leukemia cells xenograft model.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5038-5038
    Kurzfassung: Object: To the effect of Fe3O4-magnetic nanoparticle loaded with DNR on multidrugresistant K562 cells in vivo. Methods: K562-n and its MDR counterpart K562-n/VCR cell were inoculated subcutaneously into both sides of the back of nude mice (5×106 cells/each) to establish a human leukemia xenograft model. The mice were randomly divided into group A receiving normal saline every other day for 20days, group B receiving DNR every other day for 20days, group C receiving Fe3O4-magnetic nanoparticle every other day for 20days, group D receiving Fe3O4-magnetic nanoparticle loaded with DNR every other day for 20days, and group E receiving Fe3O4-magnetic nanoparticle containing DNR every other day for 20days with a magnetic field built on the surface of the tumor tissue. The tumor volume was measured on the day 1, 5, 9, 13, 17 and 21d after the first treatment. Tumor tissues were isolated for examination of the expression of mdr-1, bcl-2, bax and caspase-3 by reverse transcription polymerase chain reaction and Western blotting. Results: For K562-n/VCR tumor, the tumor volume was markedly lower in groups D and E than in groups A, B and C (group D or E vs group A, B or C, P & lt; 0.05). The transcription of mdr-1 and Bcl-2 gene was significantly lower in groups D and E than in groups A, B and C (group D or E vs group A, B or C, P & lt; 0.05). So did the protein expression of Bcl-2. However, there were no differences among these groups about the protein expression of P-gp. The protein and mRNA expressions of Bax and Caspase-3 in groups D and E were increased significantly compared with groups A, B and C (group D or E vs group A, B or C, P & lt; 0.05). The tumor volume of K562-n was markedly lower in groups C, D and E than in groups A and B (group C, D or E vs group A or B, P & lt; 0.05). Conclusion: In conclusion, DNR loaded Fe3O4-magnetic nanoparticles can suppress the growth and induce apoptosis further on the MDR K562-n/VCR tumor in vivo compared to DNR alone but not on the K562-n tumor. The external magnetic field failed to improve the antitumor effect.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5065-5065
    Kurzfassung: Objective Previous researches confirmed that multidrugresistance(MDR) plays an important role in the failure of chemotherapy on malignant tumors. This study was to investigate the molecular biological mechanisms of cyclosporine A(CsA), tetrandrine(Tet) and their combination on multidrug resistance cell line K562/A02. Methods K562/A02 cells were treated with cyclosporine A and (or) tetrandrine. The intracellular DNR concentration and the expression of P-glyco-protein (P-gp) were observed by flow cytometry (FCM) assay. The mRNA expression of mdr-1 was measured by fluorescent semi-quantitative reverse transcriptase polymerase chain reaction(RT-PCR). Resulds CsA and Tet (alone or combination) elevated the intracellular DNR concentration in K562/A02 cells(the fluorescence intensity of intracellelar DNR in K562/A02 cells was 60%,65% and 98% respectively of that in K562 cells); The fluorescence intensity of P-gp in K562 and K562/A02 cells was 0.5% and 97.97%. The P-gp expression was down after treated with CsA,Tet and both(75.32%,76.86% and 48.61%); mdr1 mRNA was also down regulated, and the effect of their combination was greater. Conclusion Multidrug resistance (MDR) can be partially reversed by CsA or Tet, the combination of both drugs shows a great synergistic reversal effect.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5066-5066
    Kurzfassung: Object: To study the variation of p21, P-gp expression in reversion of multidrug resistance of K562/A02 leukemic line with different concentration of tetrandrine(TET), to provide new theoretic evidence for the clinical application of TET. Methods: The IC50 (the concentration causing 50% inhibition of cell growth) of DNR was analyzed by MTT method; The Expressions of p21 were assayed by westernblot; The Expressions of P-gp were assayed by FCM; The expressions of mdr1 were assayed by RT-PCR; The variation of p21 was accentuation with the accrescence concentration of TET(P & lt;0.05). Results: The variation of p21 protein in K562/A02 cells was accentuation with the accrescence concentration of TET(p & lt;0.05), Mdr1 mRNA was lowly displayed in K562 cells and highly displayed in K562/A02 cells(p & lt;0.01), the variation of mdr1 was attenuation with the accrescence concentration of TET(p & lt;0.05); P-gp was lowly displayed in K562 cells and highly displayed in K562/A02 cells(p & lt;0.01), the variation of P-gp was attenuation with the accrescence concentration of TET(p & lt;0.05). Conclusion: TET may reverse multidrug resistance of K562/A02 cells by the regulation of p21,P-gp and mdr1.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5060-5060
    Kurzfassung: Objective: To observe the apoptosis of K562/A02 cells induced by application of Fe3O4-Magnetic Nanoparticle (Fe3O4-MNPs) loaded with Daunorubicin(DNR) and 5-Bromotetrandrine (BrTet) and to explore its possible molecular mechanism. Methods: We detected the apoptosis of K562/A02 cells after treatment with Fe3O4-MNPs and BrTet with DNR alone or their combination by flow cytometry(FCM),Wright staining and DNA ladder. The expression of Bax and Bcl-2 protein was measured by Western blot. Results: The result showed apoptotic characteristics after treated with this composite for 48 hours. Flow cytometry assay showed the percentage of apoptotic cells which were treated with Fe3O4-MNPs and BrTet with DNR alone or their combination for 48 hours increased from (7.9%±0.35)% to (15.5%±0.87)%, (19.7%±1.04)% and(40.8%±1.74)%, (P & lt;0.05. After treated with this composite, the typical apoptotic morphological features appeared: condensation of cells and nuclear, disintegration of nuclear chromatin, and apoptotic body could be observed under microscope; DNA agarose gel electrophoresis showed ladder bands; the expression level of Bax protein increased (P & lt; 0.01) and Bcl-2 protein decreased markedly (P & lt; 0.01). Conclusion: Our results suggest that Fe3O4-MNPs or BrTet with DNR induces apoptosis in K562/ADM cells, and when used together,they have distinct synergism. The up-regulation of Bax protein and the down-regulation of Bcl-2 protein may play important roles.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5062-5062
    Kurzfassung: Object: To the effect of Fe3O4-magnetic nanoparticle loaded with DNR on In order to study the multidrug-resistant reversal effect of Fe3O4-magnetic nanoparticle loaded with DNR in vivo. Methods: K562-n,a leukemia cell line with high tumorigenicity in nude mice and its multidrug-resistant counterpart K562-n/VCR cells were inoculated subcutaneously into each groins of nude mice (5×106 cells/each) to establish a human leukemia xenograft model. The mice were randomly divided into group A receiving normal saline, group B receiving anti-tumor drugs daunorubicin (DNR), group C receiving Fe3O4-magnetic nanoparticle, group D receiving Fe3O4-magnetic nanoparticle loaded with DNR, and group E receiving Fe3O4-magnetic nanoparticle containing DNR with a magnetic field built on the surface of tumor tissues. After 20 days treatments, mice were killed and tumor tissues were isolated for pathological observation. The volume and weight of tumors were measured, then tumor suppression rate was calculated. The side effects of DNR loaded Fe3O4-magnetic nanoparticle were also evaluated. Results: The results showed that DNR loaded Fe3O4-magnetic nanoparticle can significantly suppress the growth of K562-n/VCR tumor in vivo, DNR alone can greatly suppress the growth of K562-n, Fe3O4-magnetic nanoparticle loaded with DNR can not further inhibit the K562-n tumor. Conclusion: In conclusion, Fe3O4-magnetic nanoparticle loaded with DNR can reverse the leukemia multidrug resistance in vivo.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5063-5063
    Kurzfassung: Objective: To study the reversal effect of Tetrandrine(Tet) and the estrogen-receptor inhibitor,toremifene(Tor),on multidrug resistance cell line K562/A02 and to investigate the reversal mechanism of this combination. Methods: ADM accumulation and the apoptosis percentage of K562 and K562/A02 cells were analyzed by fluorospectrophotometry, respectively. The protein levels of P-glycoprotein (P-gp) were detected by fluorospectrophotometry. The mRNA levels of mdr1 and Survivin were determined by RT-PCR. Results: The IC50 of ADM for K562/A02 and K562 cells were 57.43±4.55mg/L and 1.16±0.05mg/L respectively. Pretreating K562/A02 cells with toremifene(2.5μmol/L) or Tet(1μmol/L) for 72 hours partially restored the sensitivity of K562/A02 cells to ADM (IC50 were 20.74±1.62mg/L and 14.12±1.20mg/L respectively) but had no effect on K562 cells; IC50 of combined tetrandrine and toremifene was 9.14±1.03mg/L;K562/A02 showed apoptotic characteristics after treated with tetrandrine, toremifene (alone or combination);tetrandrine and toremifene (alone or combination) elevated the intracellular ADM accumulation in K562/A02; P-gp, mdr1 and Survivin mRNA were down regulated. Conclusion: Tetrandrine, toremifene (alone or combination) showed significant MDR reversal activity in vitro The reversal activity may be related to the inhibition of P-gp overexpression and down regulation the expression of mdr1 and Survivin mRNA to increase the intracellular accumulation of anticancer drugs, which lead to more K562/A02 cells apoptosis; Multidrug resistance (MDR) can be partially reversed by Tet or Tor of which the combination shows a great synergistic reversal effect.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5064-5064
    Kurzfassung: Objective To evaluate the MDR reversal activity of magnetic nanoparticle Fe3O4 (Nano-Fe3O4) and 5-bromotetrandrine (BrTet) on multidrug resistance cell line K562/A02 solitarily or symphysially, and to investigate the reversal mechanism of this coopration. Methods The proliferation of K562 and K562/A02 cells which were cultured with daunomycin (DNR) alone or in combination with Nano-Fe3O4, BrTet or both for 48h were evaluated by MTT assay. DNR accumulation and P-gp of K562 and K562/A02 were analyzed by fluorospectrophotometry. Results The IC50 of DNR for K562 and K562/A02 cells were 2.74±0.19μM and 32.33±8.40μM, respectively; but the sensitivity of K562/A02 cells to DNR was partially restored after culturing with Nano-Fe3O4, BrTet solitarily and symphysially (the IC50 were 7.04±0.85μM, 4.25±2.16μM, 1.80±0.30μM; the FR were 4.32, 7.61, 17.96, respectively), but had no effects on K562 cell lines. The differences had statistical significance. Flow cytometry assay showed that Nano-Fe3O4 and BrTet increased the DNR accumulation in K562/A02 cells, especially in the group of synergia of these two agents. The mean fluorescence intensity of endocellular DNR increased from 2614 pretreated with DNR only to 4783 incubated with these two reversal reagents, while the values were 3364, 4077 for incubating with Nano-Fe3O4 and BrTet respectively. P-gp were down regulated through pretreating with Nano-Fe3O4, BrTet alone and symphysially in K562/A02 cells by fluorospectrophotometry assay. Conclusion Nano-Fe3O4 and BrTet synergisticly showed significant MDR reversal activity in vitro. The reversal activity may be related to the inhibition of P-gp overexpression and the increasing of the anticancer drug accumulation intracelluarly.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 4497-4497
    Kurzfassung: Objective Aberrant DNA methylation of CpG site is among the earliest and most frequent alterations in cancer. The aim of this study was to study whether phenylhexyl isothiocyanate can reduce the methylation level of P16 gene. This study used a microarray-based method for quantificationally detecting changes of P16 gene methylation in leukemia patient and U266 cell line. And to simply discuss the effect of phenylhexyl isothiocyanate on tumor methylation. Methods This method used bisulfite-modified DNA as a template for PCR amplification, resulting in conversion of unmethylated cytosine, but not methylated cytosine, into thymine within CpG islands of interest. One set of oligonucleotide probes were designed to fabricate a DNA microarray to detect the methylation changes of P16 gene CpG islands. Each set contained a pair of methylated and unmethylated oligonucleotides for interrogating 3 CpG sites in close proximity. By TA cloning, PCR, sequencing, positive and negative DNA targets were required. Next drawing a standard curve by fluorescence intensity. Leukemia samples DNA were abstracted and bisulfite-modified. Sample DNA targets were required by PCR amplification and were hybridized with the microarry. Finally the microarry was scanned with ScanArray Lite microarray analysis systems. Results The linear relationship (R2=0.9660) was established and it could be used to eliminate background noise. The methylation level of U266 is hypermethylation, after cultured with PHI, the level reduce. Eleven patients have P16 gene hypermethylation in thrity. After culture with PHI, seven patients showed level reduce, one patient showed raise, three patients showed remaining. Conclusion PHI can reduce the methylation level of P16 gene in U266 cell line, and also can reduce the methylation level of P16 gene of leukemia patient samples in vitro culture.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5061-5061
    Kurzfassung: Objective: To investigate the effect of 6-phenylhexyl isothiocyanate (PHI) on drug resistance and sensitivity on K562/A02 cell line to ADM and elucidate the probable mechanisms. Methods: We measured growth inhibition of ADM on K562/A02 cell line by MTT assay. Apoptosis rate of K562/A02 cell line, the change of intracellular ADM and MRP1 protein level were detected by Flow Cytometry. Intracellular deoxidized GSH by spectrometric enzyme assay and MRP1 mRNA by RT-PCR semiquantitative assay were observed anteroposterior using PHI. Results: PHI can enhance the sensitivity of K562/A02 cell line to ADM, survival rate of K562/A02 cell line decreased with the increasing concentration of PHI and ADM. Apoptosis rate increased with treating by combination of two above drugs, and multiple of drug resistance had statistical significance (P & lt;0.05) when the concentration of PHI was more than 20μmol/l. Intracellular GSH of K562/A02 cell line reduced 5% when 1μg/ml ADM was single used, and when more than 10μmol/l PHI was used it increased slightly at first then decreased. When more than 20μmol/l PHI and 1μg/ml ADM were used combination, intracellular GSH of K562/A02 cell line decreased progressively with increasing the concentration of PHI. Protein and gene level of MRP1 have no statistical significance (P & gt;0.05) no matter after or before PHI was used on different concentration. Conlusion: The depletion effect of PHI on the intracellular GSH can not only partly enhance the reverse effect of ADM, but also enhance the sensitivity of K562/A02 cell line to ADM. Such depletion may diminish side effect and treatment dosage of ADM. It provides a new view to the therapy of leukaemia.
    Materialart: Online-Ressource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Society of Hematology
    Publikationsdatum: 2008
    ZDB Id: 1468538-3
    ZDB Id: 80069-7
    Standort Signatur Einschränkungen Verfügbarkeit
    BibTip Andere fanden auch interessant ...
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