ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of HSP90 in proliferation and apoptosis of leukemia cells K562 through detecting the effect of HSP90 inhibitors 17-[2-(Dimethylamino) ethyl] amino-17-desmethoxygeldanamycin(17-DMAG) on leukemia K562 cell lines.</p><p><b>METHODS</b>The K562 cells were treated with HSP90 inhibitors 17-DMAG, the semi-quantitative PCR was used to detect HSP90 gene expression, the WST was used to detect the effect 17-DMAG on cell proliferation as well as Annexin V flow cytometry was used to detect the cell apoptosis.</p><p><b>RESULTS</b>After 17-DMAG treated the K562 cells in different stage, the K562 cell growth was obviously inhibited with time dependent (48 h)(r=0.9918) and dose dependent(3.2 µmol/L) manners (r=0.9999) (P<0.01); after the K562 cells in different stage were treated with different concentrations of 17-DMAG, the K562 cells showed significant apoptosis and with dosage-dependent mauner (r=0.9903)(P<0.01); HSP90 mRNA expression decreased significantly after K562 cells were treated with different concentrations of 17-DMAG for 48 hours. 17-DAMG down-regulated the HSP90 mRNA expression in dosage-dependent mauner as well(r=0.9227) (P<0.01).</p><p><b>CONCLUSION</b>HSP90 inhibitor 17-DMAG can inhibit the proliferation of K562 cells and induce their apoptosis. This study result provides laboratory basis for the treatment of leukemia patients with 17-DMAG.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To explore the effect of heat shock protein 90(HSP90) inhibitor 17-DMAG, an inhibitor specific for heat shock protein 90, on the proliferation and apoptosis of acute lymphocytic leukemia cell lines Jurkat.</p><p><b>METHODS</b>Jurkat cells were collected, then were treated with 17-DMAG. The expression of HSP90 was examined by semi-quantitative RT-PCR analysis, the effect of 17-DMAG on cell proliferation were detected by using WST, and cell apoptosis were detected by using flow cytometry with Annexin V/PI double stenining.</p><p><b>RESULTS</b>After Jurkat cells were treated with different concentrations of 17-DMAG for 48 hours, the HSP90 mRNA expression decreased significantly in dose dependent manner (r=0.9530, P<0.01). The ICwas 3.17 mmol/L when the Jurkat cells were treated with 17-DMAG for 48 h; after treating Jurkat cell with 17-DMAG, the cell proliferation was inhibited(r=0.9903, P< 0.01), the cell apoptosis was increased in dose dependent manner (r=0.9876, P<0.01).</p><p><b>CONCLUSION</b>17-DMAG can inhibit the Jurkat cell proliferation and induce the Jurkat cell apoptosis.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To explore the mRNA expression of Aurora-A,B,C(AUR-A,B,C) in acute leukemia(AL) and their correlations with the clinical indications.</p><p><b>METHODS</b>The mRNA expression levels of AUR-A,B,C in 73 cases of newly diagnosed AL (untreated group), 20 cases of AL with remission (remission group) and 14 healthy volunteers as control (healthy group) were detected by QRT-PCR, and the difference of expression levels in difference groups, their correlations with clinical indicators and the correlation between the AUR-A,B,C mRNA expression levels themselves were analyzed.</p><p><b>RESULTS</b>The mRNA expression levels of AUR-A,B,C in untreated group were all higher than those in healthy group and remission group(P<0.01), but there was not significant difference between healthy group and remission group(P>0.05); the mRNA expressions of AUR-A,B,C in acute lymphoblastic leukemia(ALL) group were all significantly higher than that in AML group(P<0.01). The mRNA expression of AUR-A,B,C in high risk group was higher than that in low risk group(P<0.05), but there was no difference in mRNA expression of AUR-A,B,C between high risk group and middle risk group as well as between middle risk group and low risk group(P>0.05). The mRNA expression of AUR-A, B, C in CD34, CD71 and CD56 negative group was not statistically different from that in CD34,CD71 and CD56 positive group(P>0.05). In 73 cases of newly diagnosed AL, the mRNA expression levels of AUR-A, B significantly were positively correlated with lactate dehydrogenase(LDH) level and risk stratification (r=0.279, P=0.017; r=0.314, P=0.007 and r=0.277, P=0.018; r=0.349, P=0.002), while the mRNA expression levels of AUR-A, B were not significantly correlated with age, WBC count, blast ratio in bone marrow at initial diagnosis and remission or no-remission after 1 cours of chemotherapy; the mRNA expression level of AUR-C was significantly positively correlated with WBC count (r=0.263, P=0.025), and LDH level (r=0.348, P=0.003) at initial diagnosis and risk stratificantion(r=0.376, P=0.001), and negatively correlated with age (r=-0.241, P=0.040), and was not significantly correlated with blast ratio in bone marrow at initial diagnosis and remission or noremission after 1 course of chemotherapy. There were significant positive correlations in the mRNA expression between AUR-A and B (r=0.444, P=0.000), AUR-B and C (r=0.763, P=0.000) as well as AUR-A and C (r=0.616, P=0.000).</p><p><b>CONCLUSION</b>Aur-A, B, C mRNA were highly expressed in patients with newly diagnosed AL, moreover the mRNA expression levels of Aur-A,B,C were positively correlated with each other, the high expression of Aur-A, B, C are associated with leukemia types, risk stratification, WBC count and LDH level at initial diagnosis, so they all maybe used as the prognostic markers and potential therapeutic targets.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of two histone deacetylase (HDAC) inhibitors, valproic acid (VPA) and TSA, on the expression of vascular endothelial growth factor (VEGF) and its receptor KDR of the leukemia cell line Kasumi-1 cells, and to explore their potential mechanism in leukemia angiogenesis.</p><p><b>METHOD</b>Kasumi-1 cells were treated with VPA and TSA at different concentrations for 3 days. The mRNA and protein expression levels of VEGF and KDR were determined by semi-quantitative RT-PCR and Western blot, and the bFGF mRNA by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>As compared with that of control groups, VPA at 3 mmol/L downregulated the VEGF mRNA expression level for VEGF(121) from 0.632 ± 0.014 to 0.034 ± 0.004 and for VEGF(165) from 0.526 ± 0.021 to 0.015 ± 0.001, for KDR mRNA from 0.258 ± 0.034 to 0.038 ± 0.000, and for bFGF mRNA from 0.228 ± 0.017 to 0.086 ± 0.015. TSA downregulated the VEGF mRNA and KDR mRNA at concentration of 100 nmol/L, but its effect on bFGF mRNA only at higher concentration.</p><p><b>CONCLUSION</b>HDAC inhibitors might inhibit the leukemia angiogenesis by regulating the expression of VEGF and its recptor.</p>
Subject(s)
Humans , Angiogenesis Inducing Agents , Cell Line , Histone Deacetylase Inhibitors , Pharmacology , RNA, Messenger , Genetics , Valproic Acid , Pharmacology , Vascular Endothelial Growth Factor AABSTRACT
This study was aimed to investigate the mechanism of histone deacetylase (HDAC) inhibitor, valproic acid (VPA), reversing transcription inhibition of AML1-ETO fusion protein in Kasumi-1 cell line. The mRNA expressions of AML1-ETO, AML1 and cyclin D2 were detected by semi-quantitation RT-PCR after treating kasumi-1 cells with VPA at different doses/and different time points. The results indicated that the mRNA expression of AML1-ETO showed no obvious change, when kasumi-1 cells were treated with VPA. Compared with control group, the expression level of AML1 mRNA significantly increased in a dose-dependent manner. Compared with control group, the expression level of cyclin D2 mRNA significantly decreased when kasumi-1 cells had been treated with 3 mmol/L VPA as well as kasumi-1 cells were treated with different concentrations of VPA for 3 days. In conclusion, VPA could remove transcription inhibition of AML1-ETO fusion protein, increase transcription of AML1 and down-regulate mRNA expression of AML1 target gene cyclin D2 through HDAC inhibiting activity.