GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Material
Person/Organisation
Language
Years
  • 1
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4856-4856
    Abstract: Abstract 4856 Objective: The multidrug resistance (MDR) in leukemia is a major chemotherapy obstacle, rendering many currently available chemotherapeutic drugs ineffective. The aim of this study was to explore the new strategy to early diagnose the MDR by electrochemical biosensor based on carbon nanotubes–drug supramolecular interaction. Methods: The carbon nanotubes modified glassy carbon electrodes (CNTs/GCE) as a sensor were directly immersed into the cells suspension of the sensitive leukemia cells K562 and/or its MDR cells K562/A02 to detect the response of the electrochemical probe of daunorubicin (DNR) residues after incubated with cells. Results: The fresh evidence from the electrochemical studies based on CNTs/GCE demonstrated that the homogeneous, label-free strategy could directly measure the function of cell membrane transporters in MDR cancer cells, identify the cancer cell phenotype (sensitive or MDR). The cathodic peak current showed good linear response to the changes of the fraction of MDR with a correlation coefficient of 0.995 when we further took the different ratios of the sensitive leukemia cells K562 and its MDR ones K562/A02 as the model of MDR levels to simulate the MDR occurrence in leukemia. Then, we can easily predict the MDR fraction based on the calibration curve of the cathodic peak current versus the fraction of MDR according to the obtained peak current. Conclusion: These results indicated that the biosensing assay could provide a powerful tool for assessment of MDR in leukemia. The new electrochemical biosensor based on carbon nanotubes–drug supramolecular interaction could represent promising approach in the rapid diagnosis of MDR in leukemia. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5058-5058
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5038-5038
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5059-5059
    Abstract: Objective This study was to compare the reversal effect of 5-bromotetrandrine (BrTet) with Tetrandrine (Tet) when combined with ADM on multidrug resistance cell line K562/A02 and to investigate the reversal mechanism of this new derivative. Methods The protein levels of P-glycoprotein (P-gp) were detected by fluorospectrophotometry and Western blot. The mRNA levels of P-gp were determined by RT-PCR. The in vivo effect of Tet was investigated using nude mice grafted with sensitive human leukemia cell line K562 and MDR cell line K562/A02. Results Flow cytometry assay showed that 1.0 μMol/L BrTet significantly increased the apoptosis percentage. BrTet also enhanced the intracellular accumulation of ADM in K562/A02 cells and its potency was greater than that of Tet at the same concentrations. BrTet inhibited the overexpression of P-gp and down regulated MDR1 mRNA expression in K562/A02 cells in a dose-dependent manner. In nude mice bearing K562 xenografts on the left flank and K562/A02 xenografts on the right flank, i.p. injection of 10 mg/kg BrTet significantly enhanced the antitumor activity of ADM against K562/A02 xenografts with inhibitory rates of 26.1%, while ADM alone inhibited the growth of KBv200 xenografts by only 5.8%. Conclusion BrTet showed significant MDR reversal activity in vitro and in vivo. Its activity may be related to the inhibition of P-gp overexpression and the increase in intracellular accumulation of anticancer drugs, which lead to more K562/A02 cells apoptosis.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5060-5060
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 4947-4947
    Abstract: Abstract 4947 Objective: The aim of this study was to investigate the expression of survivin and the apoptosis induced by DNR and BrTet in the leukemic cells K562/A02. Methods: In a typical experiment, the K562/AO2 cells were treated with daunorubicin (DNR), 5-bromotetrandrine (BrTet), or DNR and BrTet for 48 hours, and the cells treated without any drugs were used as control group. Cell proliferation was analyzed by MTT assay. Cells apoptosis and the concentration of DNR within the cells were measured by Flow cytometry (FCM). The expressions of mRNA and protein of survivin were determined by semi-quantitative reverse transcription PCR (RT-PCR) and Western blot, respectively. Results: The results of MTT assay indicated that DNR and BrTet were both able to inhibit the proliferation of K562/AO2 cells in dose-dependent manner. The fresh evidence from flow cytometry showed that a higher apoptosis rate could be induced and a higer concentration of DNR could be detected in K562/AO2 cells by DNR and BrTet as compared with those by DNR or BrTet in the same concentrations(P 〈 0.01). RT-PCR revealed that the expression of survivin mRNA, a higer expression in K562/AO2 cells with acquired resistance to adriamycin than that in parent K-562 cells, decreased in the DNR and BrTet group (P 〈 0.05), but there was no obvious change in other groups(P 〉 0.05). Western bolt demonstrated that the expression of survivin protein was much lower in the DNR and BrTet group(P 〈 0.05). Conclusion: BrTet could increase the concentration of DNR and reverse the multidrug resistance(MDR) in the K562/AO2 cells. Survivin may play an important role in apoptosis induced by DNR. Survivin could be a target for the treatment of MDR in haematopoietic malignancies. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5065-5065
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5066-5066
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    In: Blood, American Society of Hematology, Vol. 116, No. 21 ( 2010-11-19), p. 3969-3969
    Abstract: Abstract 3969 Objective: Although many strategies have been explored to overcome the multidrug resistance (MDR) in leukemia which has rendered many currently available chemotherapeutic drugs ineffective, the results have been disappointing to the obstacle. The aim of this study was to investigate whether the new strategy of combining drug-loaded nanoparticles (Nps) and ultrasound (US) would show useful effects on the reversal of MDR in human leukemia cell line K562/A02. Methods: In this study, daunorubicin (DNR), a frequently chemotherapeutic agent known to cause DNA damage and induce apoptosis and cell death, was loaded on the TiO2 Nps which is chemically stable, environmental friendly, and shows weak or non cytotoxic to apply as the nano-drug carrier. The MDR leukemia K562/A02 cells were treated with the DNR-loaded TiO2 Nps drug carrier and US exposure. Then, we examined the effectiveness of delivering DNR into the MDR leukemia K562/A02 cells with the electrochemical studies, observed the bio-effects on the cell viability by MTT assays, investigated the induced apoptosis, and assessed the reversal ability and the mechanism of MDR by combining the drug-loaded Nps and US. Results: We observed good biocompatibility of the therapeutic approach. When the K562/A02 cells were incubated with DNR only, the cathodic current decreased by only 10% normalized to the DNR (10 μg/mL) standard, indicating less DNR was absorbed by the MDR cells. The cathodic current decreased by 39% and 63% in the presence of US or DNR-loaded TiO2 Nps, respectively. In comparison, when the cells were treated by the novel strategy of US mediated drug-loaded Nps crossing cell membranes, the cathodic current of DNR in the supernatant decreased greatly by 82% and became the minimal, which suggesting the least amount of DNR remained outside the MDR cells in this case and the largest uptake into the cells by this new strategy. These observations demonstrated that the remarkable synergistic effect of the novel strategy facilitated the accumulation of DNR in the MDR K562/A02 cells. In addition, our MTT assay illustrated comparative sensitization of the MDR K562/A02 cells under the treatment of US or drug-loaded Nps, but especially enhanced effect by combining drug-loaded Nps and US. The resisting fold of the MDR leukemia K562/A02 became obviously lower, decreasing from 58.71 to 16.69. The fresh evidence from caspase-3 immunocytochemistry demonstrated that the strategy could induce the apoptosis in the cells as well. Conclusion: It was therefore concluded that the strategy could have good reversal ability of MDR in tumor. These findings reveal that the reversal of MDR in tumor by US mediated drug-loaded Nps crossing cell membranes could represent promising approach in cancer therapy. Disclosures: No relevant conflicts of interest to declare.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2010
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    In: Blood, American Society of Hematology, Vol. 112, No. 11 ( 2008-11-16), p. 5062-5062
    Abstract: 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.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
    RVK:
    RVK:
    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2008
    detail.hit.zdb_id: 1468538-3
    detail.hit.zdb_id: 80069-7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...