BMS-345541 regulates repair of DNA double-strand breaks induced by VP-16 in acute myeloid leukemia cells / 中国药理学通报

Aim To investigate the effect of BMS- 345541 on the repair of DNA DSBs induced by VP-16 in AML cells and its possible mechanism. Methods The effects of BMS-345541 on the sensitivity of AML cells to VP-16 were determined by MTT. Flow cytome-try ( FCM) was applied to test the level of DNA dam-age, cell cycle progression and apoptosis in AML cells. High content analysis ( HCA) was used to verify the amount ofγ-H2AX,p-ATM,RAD51 in AML cells. Results BMS-345541 could significantly inhibit the proliferation of AML cells induced by VP-16 . BMS- ＜br> 345541 increased the amount of RAD51 foci and p-ATM foci in AML cells treated with VP-16 after 6 hours , which led to increased numbers of cells in the G2/M phases of the cell cycle,then induced apoptotic cell death. Conclusion BMS-345541 sensitizes AML cells to VP-16 via selective inhibition of homologous recombinational repair of DNA double-strand breaks.

XN4 inhibits proliferation of AML cells by inducing oxidative DNA damage / 中国药理学通报

Aim To investigate the cytotoxicity of XN4 against AML cells, and the underlying mechanisms by which XN4 might induce DNA damage and apoptotic cell death through reactive oxygen species ( ROS ) . Methods The proliferation inhibition ratio of AML cells was measured by MTT. The level of extracellular ROS, DNA damage, cell cycle process and apoptosis were tested by flow cytometry ( FCM ) . Western blot was applied to test the expression of proteins. Results XN4 significantly inhibited the proliferation of HL-60 and KG1α with IC50 ( 2. 79 ± 0. 15 ) μmol · L-1 and (2. 76 ± 0. 20) μmol·L-1 respectively. XN4 signifi-cantly increased the generation of intracellular ROS, followed by inducing DNA damage and activating the ATM-γ-H2AX signaling, which led to increases of cells in the S phases of the cell cycle. Subsequently, XN4 induced apoptotic cell death through activation of caspase-3 and Parp. Moreover, the above effects were all reversed by the ROS scavenger N-acetylcysteine ( NAC ) . Conclusion XN4-induced DNA damage and cell apoptosis in AML cells are mediated via ROS generation.

Expression, purification and identification for fibronectin C-terminal heparin-binding domain polypeptide in Pichia pastoris / 生物工程学报

To express and identify fibronectin C-terminal heparin-binding domain (FNCH BD) polypeptides in Pichia pastoris expression system and study its function, the fragment of FNCHBD was amplified by PCR and inserted into pGEM-T vector. After sequenced, the fragment was inserted into pAo815SM vector, and then cloned into the expression vector pPIC9k. The recombinant plasmid was linerarized with restrict enzyme Sal I and transferred into the yeast host cell KM71 and GS115. The positive yeast clone was screened by G418 resistant, and the target protein was induced to express in the medium containing 0.5% methanol. The culture supernatant was collected and then was purified with membrane ultrafiltration and ion exchange chromatography. The purified product was analyzed with mass spectrogram, SDS-PAGE, Western blotting and heparin affinity chromatography. The results showed that the target protein was around 32 kDa and the purity of the product was above 95%. FNCHBD could be specifically recognized by fibronectin polyclonal antibody. These results suggest that FNCHBD could be expressed and purified successfully in Pichia pastoris, which provides a good strategy to further studies.

Effects of Triptolide on HL-60 Cell in vitro and in vivo / 中国药理学通报

Aim To study the effects of Triptolide (TPL) on HL-60 cells in vitro and in vivo.Methods MTT was used to examine the effects of TPL on proliferation of HL-60 cells;TUNEL assay was used to detect apoptotic cells.The effect of TPL on xenograft growth of HL-60 cells was evaluated by tumor inhibition rate.Results In vitro TPL inhibited the proliferation and induced apoptosis of HL-60 cells in a dose-dependent manner.In vivo TPL inhibited xenograft growth of HL-60 cells with the highest inhibition rate of 53.5%.Conclusion TPL is able to inhibit the proliferation of HL-60 cells and induce apoptosis of HL-60 cells in vitro and in vivo.