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.