Expression of Gli1 in Adult Acute Lymphoblastic Leukemia and Its Clinical Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the expression and clinical significance of Hedgehog signaling transcription factor Gli1 in acute lymphoblastic leukemia (ALL) patients.</p><p><b>METHODS</b>The clinical specimens were obtained from 32 newly diagnosed and 6 relapsed ALL patients. Normal bone marrow cells from 15 healthy donors were used as controls. Real-time qPCR and Western blot were applied to detect Gli1 mRNA and protein expression in bone marrow mononuclear cells (BMMNC) of these samples respectively. The relation of Gli1 mRNA levels with clinical parameter was also evaluated.</p><p><b>RESULTS</b>The expression level of Gli1 mRNA in de novo and relapsed ALL patients was significantly higher than that in the normal controls (P < 0.05). There was no stalistically significant difference of the Gli1 mRNA expression between de novo and relapsed ALL cases (P > 0.05). In 24 de novo ALL patients with complete remission (CR) after induction chemotherapy, the levels of Gli1 mRNA were significantly reduced as compared with levels before treatment (P < 0.05). However, in 4 ALL patients without remission, no obvious difference of Gli1 mRNA levels were observed as compared with levels of Gli1 before treatment (P > 0.05). A positive correlation between the Gli1 mRNA expression level and white blood cell count (WBC) was found in the BMMNC of ALL patients (R = 0.725, P < 0.05). Similarly, Gli1 protein expression was significantly higher in the de novo and relapsed ALL cases compared with normal controls. The Gli1 protein level was down-regulated when the ALL patients was in CR.</p><p><b>CONCLUSION</b>The expression of Gli1 mRNA and protein has been found to be high in de novo and relapsed ALL patients, and the change of Gli1 expression maybe relate to therapeutic efficacy and prognosis of ALL patients.</p>

Decitabine inhibits cell proliferation and induces apoptosis of all-trans retinoid acid-resistant acute promyelocytic leukemia NB4-R2 cell line / 中国实验血液学杂志

The aim of this study was to investigate the proliferation-inhibitory and inducing apoptotic effects of decitabine (DAC) on acute promyelocytic leukemia NB4-R2 cells. Cell inhibitory rate was determined by cell proliferation and cytotoxicity assay (WST-1 assay) after NB4-R2 cells were treated with 0.01 - 0.5 µmol/L DAC for 24, 48 and 72 h. Apoptosis of NB4-R2 cells treated with 0.05 - 5 µmol/L DAC for 48 h was detected by flow cytometry with PI staining and AnnexinV/PI staining. Reverse transcription-PCR (RT-PCR) was used to determine the mRNA expression level of MDR1 gene encoding P-glycoprotein (P-gp). The results indicated that DAC (0.01 - 0.5 µmol/L) inhibited the proliferation of NB4-R2 cells in both time- and concentration-dependent manners. The IC(50) of DAC on the viability of NB4-R2 cells after treatment for 48 and 72 h were 0.089 and 0.064 µmol/L respectively. DAC (0.05 - 5 µmol/L) induced NB4-R2 cell apoptosis in dose-dependent manner with down-regulation of MDR 1 gene expression. It is concluded that a low concentration of DAC (< 0.5 µmol/L) inhibits cell proliferation, while higher concentration of DAC (1 or 5 µmol/L) induces apoptosis on NB4-R2 cells, accompanied with reduction of MDR1 levels.

Sorafenib induces apoptosis of U937 cells via inhibiting WNT signal pathway / 中国实验血液学杂志

This study was aimed to investigate the effect of multikinase inhibitor sorafenib on the proliferation and apoptosis of U937 cells and its possible mechanism. U937 cells were treated with different concentrations of sorafenib for 48 hours. Cell viability was determined by Cell Counting Kit-8; cell apoptosis and cell ratio in cell cycle were detected by flow cytometry with Annexin V/PI staining and PI staining respectively; expressions of GSK-3β, β-catenin and cyclin-D1 were assayed by Western blot. The results showed that the proliferation of U937 cells was inhibited by sorafenib in a dose-dependent manner (p < 0.05). Sorafenib induced cell apoptosis and cell cycle G(1)/G(0) arrest. Compared with results of Western blot before treatment, expression of inactivated GSK-3β, β-catenin and Cyclin-D1 down-regulated in a dose-dependent manner after treatment with sorafenib, this same changes were observed after up-regulation of inactivated GSK-3β by LiCl (p < 0.05). It is concluded that sorafenib inhibits the proliferation of U937 cells and induces cell apoptosis through reducing negative regulation of WNT signal pathway on inactivated GSK-3β and down-regulating β-catenin and cyclin-D1 level, which result in U937 cell cycle G(1)/G(0) arrest.

Effect of sorafenib combined with daunorubicin on K562 cell line / 中国实验血液学杂志

The aim of this study was to investigate the effect of sorafenib combined with daunorubicin on leukemic k562 cell line. The inhibitory effect of sorafenib alone and its combination with daunorubicin on K562 cell proliferation was detected by MTT method; the synergistic effect was measured by CDI (coefficient of drug interaction); the apoptosis of K562 cells was observed by flow cytometry with Hoechst 33258 staining. The results showed that the sorafenib alone or its combination with daunorubicin could significantly inhibit K562 cell proliferation and the combination of both drugs displayed synergistic effect on K562 cells, meanwhile the apoptotic cells increased. It is concluded that the combination of sorafenib and daunorubicin has a obviously synergistic inhibitory effect on leukemic cell line K562.

Significance of DNA methylation status of runx3 gene promoter region in acute leukemia / 中国实验血液学杂志

This study was aimed to investigate the effects of methylation of runx3 gene promoter on pathogenesis of acute leukemia (AL) and its clinical significance. The methylation of runx3 gene promoter in cells of bone marrow or peripheral blood from 40 cases of AL and 10 healthy persons as well as in CHRF, U937 and K562 cell lines were assuaged by methylation specific polymerase chain reaction (MS-PCR), the expression of runx3 gene were detected with reverse transcription polymerase chain reaction (RT-PCR). The results indicated that no methylation was detected in all of cell lines and healthy persons while expression of runx3 gene could be deteted, methylation of runx3 gene promoter was found in 35% (14/40) AL patients and its percentage was significant higher than that healthy persons (0%), the difference in methylation for runx3 between two kinds of samples was statistically significant (p<0.05), while methylation rate in AML was 30.43% (7/23), ALL was 41.18% (7/17), there was no significant difference between them (p>0.25). All of methylated samples had no expression of runx3 gene. Patients without methylation of runx3 gene had a lower percentage of blasts in bone marrow and a higher complete remission rate of first chemotherapy than those with methylation of runx3 gene. It is concluded that methylation of runx3 gene promoter probably plays a role in the pathogenesis of AL and may have clinical significance in predicting prognosis of AL.

Antigen-loaded dendritic cells trigger killing effects of specific cytotoxic T lymphocytes on Jurkat cells in vitro / 中国实验血液学杂志

This study was aimed to investigate the effects of tumor antigen-loaded dendritic cells (DC) stimulating the specific cytotoxic T lymphocytes (CTL) on Jurkat cells in vitro. Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation from normal human heparinized blood, the adherent monocytes were cultured with granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin-4 (IL-4), alpha tumor necrosis factor (TNF-alpha) and sCD40L, DCs were co-cultured with frozen-thawed antigen of Jurkat cells or WT1 peptides, and then T cells were triggered into specific CTL. The results showed that most suspended cells exhibited distinctive morphological features of DC which expressed CD40 (96%), CD86 (97%), CD80 (77%), CD1a (69%), and gained the powerful capacity to stimulate proliferation of allogeneic lymphocytes. Under the effector: target ratio of 20:1, CTLs derived from cultures with DC and frozen-thawed antigen of Jurkat cells showed 91.1% cytotoxicity against Jurkat cells, CTL derived from cultures with DC and WT1 peptides showed 87.5% cytotoxicity against Jurkat cells, cytotoxicity of CTL derived from cultures with unloaded DC against Jurkat cells was 42.1% and cytotoxicity of monocytes was 22.7%. Cytotoxicity of CTL derived from culture with frozen-thawed antigen or WT1 peptides loaded DC was stronger than that in control groups (P < 0.01). It is concluded that the tumor antigen-pulsed DC can induce efficient and specific anti-tumor immunity, may play a great role in clinical therapy for leukemia.