Effects of gossypol acetate on apoptosis in primary cultured cells from patients with lymphoid leukemia and its synergy with dexamethasone / 中国实验血液学杂志

To investigate the effects of gossypol acetate on apoptosis in primary cultured cells from patients with acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL) and its synergistic effect with dexamethasone. The apoptosis-inducing effect of gossypol acetate on primary cultured leukemia cells was analyzed by flow cytometry (FCM). The effect of gossypol acetate on survival rates of Raji cells and mononuclear cells (MNC) from normal bone marrow were evaluated by MTT assay. After co-treatment with gossypol acetate and dexamethasone, the apoptosis rate of Raji cells was detected by FCM. The results showed that gossypol acetate was able to induce apoptosis in primary cultured ALL cells at concentrations of ≥ 5 µmol/L. The effect was concentration and time dependent. Apoptosis-inducing concentration in CLL cells was higher than that in ALL cells. After exposing to 50 µmol/L gossypol acetate for 48 h, the apoptosis rate of ALL and CLL cells were (90.4 ± 6.2)% and (51.7 ± 10.3)% separately. No major growth inhibitory effect was observed in MNC from normal bone marrow when they were exposed to gossypol acetate at concentrations lower than 10 µmol/L. After exposing for 48 and 72 h, the IC(50) of gossypol acetate for MNC from normal bone marrow was 7.1 and 9.1 times as much as the IC(50) of Raji cells. Co-treatment with 10 µmol/L gossypol acetate and dexamethasone remarkably increased the apoptosis rate of Raji cells. It is concluded that the gossypol acetate has apoptosis-inducing activity in primary cultured leukemia cells from patients diagnosed as ALL and CLL in vitro. The inhibitory effect of gossypol acetate on MNC from normal bone marrow is less prominent than that on Raji cells. Co-treatment with gossypol acetate and dexamethasone notably amplified the pro-apoptosis activity of the latter in Raji cells.

Effect of apogossypolone on induction apoptosis in multiple myeloma cells and its mechanisms / 中国实验血液学杂志

This study was aimed to investigate the effects of apogossypolone (ApoG2) on proliferative inhibition and apoptotic induction of multiple myeloma cells and its mechanism. The effects of ApopG2 on cell growth, cell viability, cell cycle and cell apoptosis were determined by Hoechst 33258 staining, DNA ladder formation and subdiploid peak analysis respectively. Cleavage of caspase-3 and caspase-9 was analyzed by colorimetric assay. Expression of BCL-2 and BCL-XL was detected by flow cytometry. The results indicated that the ApoG2 inhibited multiple myeloma cell proliferation in dose-and time-dependent manners, with IC(50) value to both U266 and Wusl cells at 0.1 and 0.2 micromol/L at 48 hours after treatment. ApoG2 effectively inhibited the proliferation of multiple myeloma cells, the IC(50) value in U266 cells and Wusl cells (at 48 hours) were 0.1 micromol/L and 0.2 micromol/L respectively. ApoG2 could induce the apoptosis of cells of myeloma in a time-dependent manner.The typical apoptotic morphological changes were observed under transmission electron microscope, while DNA ladder formation and remarkable peak of subdiploid cells appeared. ApoG2 could arrest the myeloma cells in G(2) phase, increasing from 9.7%(0 micromol/L) to 19.6% (10 micromol/L) in U266 cells and 9.8%(0 micromol/L) to 31.7% (10 micromol/L) in Wusl cells. ApoG2 could induce increase of caspase 9 and caspase 3 activity and down-regulate the expression of BCL-XL in U266 and Wusl cells, as well as the expression of BCL-2 in Wusl cells. It is concluded that ApoG2 has significant effect of antiproliferation and induction of apoptosis on multiple myeloma cells in vitro, ant its mechanisms may involve in down-regulation of BCL-2/BCL-XL and in change of cell cycle.

Effect of gossypol acetate on proliferation and apoptosis in Raji lymphoblastoid cell line / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effects of gossypol acetate on proliferation and apoptosis in Raji lymphoblastoid cells and explore the possible mechanism.</p><p><b>METHODS</b>Trypan blue staining and ethyl thiazolyl diphenyl-tetrazolium bromide (MTT) assay were performed to measure the effect of gossypol acetate on the growth of Raji cells. The morphologic changes were observed with Wright's staining assay. Apoptosis was identified by agarose-gel electrophoresis and annexin V-FITC marked flow cytometry (FCM) analysis. The distribution of cell cycle, apoptosis rate, and Bcl-2 protein expression were analyzed by FCM. Caspase-3 activity was detected by colorimetric assay.</p><p><b>RESULTS</b>Gossypol acetate inhibited proliferation and induced apoptosis of Raji cells at concentration higher than 5 micromol/L. The effects were both dose- and time- dependent. Cycle analysis indicated the alteration of cell cycle and G0/G1 arrest. The activation of Caspase-3 was observed by colorimetric assay. The results of flow cytometry showed that the down-regulation of Bcl-2 protein expression and the activation of Caspase-3 seemed to occur simultaneously.</p><p><b>CONCLUSION</b>Gossypol acetate can inhibit the growth of Raji cells and induce their apoptosis. The mechanism may be related to the alteration of cell cycle and the down-regulation of Bcl-2 protein expression.</p>