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ABSTRACT: To investigate the synergistic effects of carnosic acid (CA) with arsenic trioxide (As(2)O(3)) on proliferation and apoptosis in HL-60 human myeloid leukemia cells, and the major cellular signaling pathway involved in these effects.
HL-60 cellular proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. Cell cycle distribution and apoptosis were monitored by flow cytometry. The activation of casepase-9, Bcl-2-associated agonist of cell death (BAD), p-BAD, p27, phosphatase and tensin homolog deleted on chromosome ten (PTEN), Akt, p-Akt was assessed by Western blot analysis. The expression of PTEN mRNA was tested by reverse transcription polymerase chain reaction (RT-PCR) analysis.
CA reduced HL-60 cell viability in a dose- and time-dependent manner, and induced G1 arrest and apoptosis. Moreover, CA upregulated PTEN expression, blocked the Akt signaling pathway, subsequently inhibited phosphorylation of BAD, reactivated caspase-9, and elevated levels of p27. CA also augmented these effects of As(2)O(3).
CA might be a novel candidate of the combination therapy for leukemia treatment; these effects were apparently associated with the modulation of PTEN/Akt signaling pathway.
Chinese Journal of Integrative Medicine 12/2012; 18(12):934-41. · 0.80 Impact Factor
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ABSTRACT: OBJECTIVE: To investigate the effects of carnosic acid (CA) on reversal of the multidrug resistance (MDR) of human leukemia cell line K562/A02 and its mechanism. METHODS: MTT assay was used to determine the sensitivity of K562/A02 cells to adriamycin (ADM) pre-and post-treated with CA. Flow cytometry (FCM) and laser scanning confocal microscopy (LSCM) were used to measure intracellular fluorescence intensity and concentration of ADM respectively. The expression level of mdr1 was detected by semi-quantitative RT-PCR. P-glycoprotein (P-gp) expression was detected by FCM and Western blot. RESULTS: CA decreased IC(50) of ADM in K562/A02 cells from 16.31 µg/mL to 1.35 µg/mL, being a 12.08-fold decrease. The intracellular ADM fluorescence intensity of K562/A02 was increased from 17.05 to 60.53 after treated with CA (P < 0.01). In living K562/A02 cells, after treated with CA, the diffuse distribution of intracellular ADM was recovered in both nuclear and cytoplasm, and the concentration of intracellular ADM increased from 4.93µg/mL to 15.43µg/mL. RT-PCR assay showed that CA inhibited the expressions of mdr1 mRNA in K562/A02 cells (P < 0.01). Mean fluorescence intensity of P-gp detected by FCM in CA-treated K562/A02 was decreased to 22.80 as compared with that in untreated K562/A02 cells (44.40, P < 0.05). CONCLUSION: CA can reverse the MDR of K562/A02 cells in vitro. The mechanism may be associated with down-regulation of mdr1 and inhibition of P-gp function.
Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 06/2010; 31(6):381-384.
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ABSTRACT: One of the common hindrances to successful chemotherapy is the development of multidrug resistance (MDR) by tumor cells to multiple chemotherapeutic agents. In this regard, P-glycoprotein (P-gp) acts as an energized drug pump that reduces the intracellular concentration of drugs, even of structurally unrelated ones. The modulators of P-gp function can restore the sensitivity of MDR cells to anticancer drugs. Therefore, to develop effective drug-resistance-reversing agents, we evaluated the P-gp modulating potential of carnosic acid (CA) in multidrug-resistant K562/AO2 cells in the present study. The reversing effect of CA was evaluated by determining the inhibition rates of cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assays. The intracellular adriamycin fluorescence intensity and the expression of P-gp were measured by flow cytometry (FCM). Meanwhile, the subcellular distribution of adriamycin was detected via Laser Scanning Confocal Microscopy (LSCM). The mRNA expression of mdrlwas then detected via semiquantitative reverse transcription polymerase chain reaction (RT-PCR). The findings showed that CA decreased apparently the Inhibition Concentration 50% (IC50) of adriamycin by increasing its intracellular concentration and thus enhancing the sensitivity of K562/AO2 cells. Adriamycin was distributed evenly in the cytoplasm when the cells were treated with CA. The expression of mdrl was decreased. Overall, the results indicated that CA can serve as a novel, non-toxic modulator of MDR, and it can reverse the MDR of K562/AO2 cells in vitro by increasing intracellular adriamycin concentration, down-regulating the expression of mdrl, and inhibiting the function of P-gp.
The Chinese journal of physiology 01/2009; 51(6):348-56. · 0.56 Impact Factor
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ABSTRACT: To explore the feasibility and efficiency of immunotherapy with dendritic cell (DC) in leukemic mice model after allogeneic bone marrow transplantation (allo-BMT).
Mature DC were expanded from mice bone marrow mononuclear cells (MNC) by adding mouse granulocyte-macrophage colony stimulating factor (mGM-CSF) and interleukin-4 (mIL-4). Three days later they were pulsed with frozen thawing L7212 leukemia-related antigen. Mice bearing leukemia received allo-BMT at d 0, and then were divided into control group (A), T cells group (B) and DC + T cells group (C) to receive respective immune therapy at d 14. The survival rate, survival time, occurrence of graft-versus-host disease (GVHD), cytotoxicity of spleen cells and serum cytokine level were observed. The survivors in each group were rechallenged with L7212 cells to observe the immune response to the leukemia.
Mature DC were successfully induced from bone marrow MNC. In groups B and C, the relapse rates were 30% and 0%, while the long term survival rates after BMT was 30% and 70% respectively. Both of the differences were statistically significant (P < 0.05). However, the incidence of GVHD in these two groups were similar. The mean survival times were (32.95 +/- 13.29) days and (41.15 +/- 13.88) days, respectively (P < 0.01). MTT assay indicated that spleen cells from group C had specific killing activity to L7212 cells. Enzyme-labeled immunosorbent assay (ELISA) showed that the serum IL-2 level in group C was (419.75 +/- 26.66) pg/ml, being significantly higher than that in the other two groups (P < 0.01). When the survivors were rechallenged with L7212 cells, there was difference between the survival rates of groups C and B (85.7% vs 33.3%, P < 0.05).
Immunotherapy with leukemia related antigen-pulsed DC in combination with donor lymphocyte infusions is an effective approach to reinforce GVL effect and decrease relapse after allo-BMT.
Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 02/2006; 27(2):73-7.
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ABSTRACT: To study the clinical efficacy and side effects of ferrous L-threonate for treatment of iron deficiency anemia (IDA).
It is a multicentral, randomized, double blind, double placebo and paralled comparative study with positive control. One hundred and forty IDA patients diagnosed according to the standard criteria in three hospitals were randomly divided into a test group (ferrous L-threonate plus placebo ferrous succinate) and a positive control group (ferrous succinate plus placebo ferrous L-threonate). Some iron parameters were examined 1, 4 and 8 weeks after medication. Hemoglobin, reticulocyte and other parameters for safety observation were collected every two weeks.
For the 2 groups, self comparison showed significant difference (P < 0.01). The total efficacy is 98.44% and 97.01% respectively with no difference. Hemoglobin rised rapidly and gradually and reached a peak in week 8, the change was statistically significant (P < 0.01). Changes of iron parameters also showed significant difference. Side-effects were similar in both groups (13.85% and 14.71%, P > 0.05).
The effect of ferrous L-threonate in IDA treatment is significant and rapid. Side-effects are few and minimal.
Zhonghua nei ke za zhi [Chinese journal of internal medicine] 11/2005; 44(11):844-7.
