Effects of artesunate combined with bortezomib on apoptosis and autophagy of acute myeloid leukemia cells in vitro and its mechanism / 中华血液学杂志

Objective@#To investigate the effects of artesunate combined with bortezomib on the proliferation, apoptosis and autophagy of human acute myeloid leukemia cell lines MV4-11, and its mechanisms.@*Methods@#MTT method was used to determine the anti-proliferation effect of different concentrations of artesunate, bortezomib and their combination on MV4-11 cells. The cell apoptosis were analyzed by flow cytometry. The expression of cleaved-Caspase-3, Bcl-2 family protein (Bcl-2, Mcl-1, Bim, Bax) and autophagy-related protein LC3B were assayed by Western blot.@*Results@#Artesunate displayed a proliferation inhibition effect on MV4-11 with dose- and time-dependent manner, the IC50 of artesunate on MV4-11 after 48 hours was 1.44 μg/ml. Bortezomib displayed a proliferation inhibition effect on MV4-11 with dose-dependent manner, the IC50 of bortezomib on MV4-11 after 48 hours was 8.97 nmol/L. The combination of artesunate (0.75, 1.0 μg/ml) and Bortezomib (6, 8 nmol/L) showed higher inhibition on MV4-11 than artesunate or bortezomib alone in the same concentration gradient after 48 hours (P<0.05) . The cooperation index of the two drugs were all less than 1. The 48 h apoptotic rate of artesunate (1.5 μg/ml) on MV4-11 was (15.27±2.18) %, (19.85±3.23) % of bortezomib (8 nmol/L) , (81.67±5.96) % of combination of the two drugs, significantly higher than the single group (P<0.05) . When combination of the two drugs on MV4-11 after 24 hours, the levels of pro-apoptotic protein Bim and the cleaved activation of Caspase-3 and autophagy-related protein LC3B were up-regulated and the anti-apoptotic protein Bcl-2 expressions was down-regulated.@*Conclusion@#Combination of artesunate with bortezomib shows a significant synergistic effects on proliferation, apoptosis and autophagy of MV4-11 cell lines, which may be associated with Bcl-2 family proteins expression.

Baicalein induces apoptosis in human ovarian cancer HO-8910 cells by activating Caspase and Bcl-2 family proteins / 中草药

Objective: To explore the apoptotic effect of baicalein, a coumarin flavonone, on human ovarian carcinoma HO-8910 cells, as well as the mechanisms. Methods: HO-8910 cells were treated with esculetin at a series of concentrations for different times. Expression of apoptosis related Bax/Bcl-2, and Caspases proteins in esculetin treated HO-8910 cells were detected by Western blotting. Cell growth and apoptosis were measured by MTT test and flow cytometry in vitro. Results: Cell viability assay showed that esculetin had obvious anti-proliferation effects on HO-8910 cells in a dose- and time-dependent manner. Compared with control group, the group treated with esculetin showed a significant increase in apoptosis rate (P < 0.05, P < 0.01). The results demonstrated that esculetin up-regulated the Bax/Bcl-2 ratio and cleaved Caspase-3, cleaved Caspase-9 expression in a dose-dependent manner. Conclusion: In summary, baicalein exerts anti-growth and induced-apoptosis activity against ovarian cancer HO-8910 cells through activating Caspase and Bcl-2 family proteins, therefore presenting as a promising therapeutic agent for the treatment of ovarian cancer.

Apoptotic effects of polyporusterone A on estrogen receptor negative breast cancer cells via regulating Bcl-2/Bax pathway / 中草药

Objective To explore the apoptotic effect of polyporusterone A on estrogen receptor (ER)-positive and ER-negative human breast cancer cells and the possible mechanism. Methods Three human breast cancer cell lines (MDA-MB-453, MCF-7, and BT474) were chosen in this study. MTT assay was performed to measure the relative cell viabilities. Flow cytometry was used to analyze the apoptosis and cell cycle. Western blot analysis was used to determine the expression levels of Bcl-2 family proteins. Results Cell proliferation of ER-negative human breast cancer cells was significantly inhibited by polyporusterone A in a dose-and time-dependent manner, while no significant effect was observed on the proliferation of strogen receptor (ER)-positive human breast cancer MCF-7 and BT474 cells. Moreover, polyporusterone A could reversibly arrest the MDA-MB-253 cells in G1 or G2/M phase. Flow cytometry results showed that 50 μmol/L polyporusterone A induced MDA-MB-253 cells apoptosis after treatment for 24 h, while no apoptosis occurred in MCF-7 and BT474 cell lines. Western blot results showed that 50 μmol/L polyporusterone A up-regulated the protein expression of Bad and Bax, but down-regulated the expression of Bcl-2 and Bcl-w protein. Conclusion Polyporusterone A can inhibit the proliferation of ER-negative breast cancer cells and promote apoptosis, which may be associated with the regulation of the expression of Bcl-2 family proteins.

Anti-proliferative Effects of Androctonus amoreuxi Scorpion and Cerastes cerastes Snake Venoms on Human Prostate Cancer Cells

The present study evaluated the effects of Androctonus amoreuxi scorpion venom, Cerastes cerastes snake venom and their mixture on prostate cancer cells (PC3). An MTT assay was used to determine the anti-proliferative effect of the venoms, while quantitative real time PCR was used to evaluate the expression of apoptosis-related genes (Bax and Bcl-2). Furthermore, colorimetric assays were used to measure the levels of malondialdehyde (MDA) and antioxidant enzymes. Our results show that the venoms significantly reduced PC3 cell viability in a dose-dependent manner. On the other hand, these venoms significantly decreased Bcl-2 gene expression. Additionally, C. cerastes venom significantly reduced Bax gene expression, while A. amoreuxi venom and a mixture of A. amoreuxi & C. cerastes venoms did not alter Bax expression. Consequently, these venoms significantly increased the Bax/Bcl-2 ratio and the oxidative stress biomarker MDA. Furthermore, these venoms also increased the activity levels of the antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. Overall, the venoms have cytotoxic and anti-proliferative effects on PC3 cells.

Apoptotic Effect of Macrophages against Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb) causing tuberculosis as an intracellular pathogen initially infects alveolar macrophages following aerosol inhalation. Thus, macrophages play a critical role in the establishment of Mtb infection and macrophage cell death, a common outcome during Mtb infection, may initiate host- or pathogen-favored immune responses, resulting in facilitating protection or pathogenesis, respectively. In addition, virulent Mtb strains are known to inhibit apoptosis and consequently down-regulates immune response using a variety of strategies. In many recent studies have shown that virulent Mtb can either augment or reduce apoptosis by regulating expression of pro-apoptotic and anti-apoptotic proteins belonging to Bcl-2 family proteins. In this review, we will discuss and dissect the apoptotic pathways of Bcl-2 family proteins in Mtb-infected macrophages.

On mitochondrial quality control regulated by Bcl-2 family / 中国药理学通报

Mitochondrial quality control is the important mecha-nism that regulates the morphology,quantity and quality of mito-chondrial in cell to maintain cellular homeostasis and thus,cell survival and health.It has been revealed that members of Bcl-2 family are linked to mitochondrial function and integrity.Bcl-2 family proteins are the key regulators of mitochondrial quality control,participating in the signaling pathways regulating the crosstalk between mitophagy and apoptosis,as well as mitochon-drial fission and fusion.This paper mainly reviews their impact on mitochondrial quality and the major signaling pathways regula-ted by Bcl-2 family proteins.

Mycophenolic Acid Induced Apoptotic Signal Transduction in Molt-4 T-cells

PURPOSE: Mycophenolic acid (MPA), a selective inhibitor of inosine monophosphate dehydrogenase (IMPDH), is the active metabolite of the immunosuppressive drug, mycophenolate mofetil (MMF). MMF is used to prevent an immune- mediate rejection response following organ transplantation via the inhibition of the IMPDH and GTP biosynthesis pathway. This study was designed to elucidate the mechanism by which MPA exerts its cytotoxic effect on human T lymphocytic and monocytic cell lines. METHODS: MOLT-4 and U937 cell lines were treated with MPA. Cell viability, expression of Bcl2 family proteins and Fas/Fas-L, effects of antioxidants and intracellular Ca2+ regulating agents and apoptosis were measured using a variety of microscopic and biochemical techniques. RESULTS: MPA induced the death of U937 and MOLT-4 cells in dose and time dependent manners, which was revealed an apoptosis with a characteristic ladder pattern of DNA fragmentation. In addition, BAPTA/AM, an intracellular Ca2+ chelator protected MOLT-4 cells from MPA treated apoptosis, although it did not have an additive with thapsigargin, and increases cytosolic Ca2+ stores. However, antioxidants including reduced glutathione (GSH) and N-acetyl-L-cysteine (NAC) did not inhibit the apoptosis of cells by MPA. Furthermore, guanosine suppressed MPA induced apoptosis of MOLT-4 lymphocytes, although adenosine did not. MPA also increased the catalytic activity of caspase family cysteine proteases including caspase-8, 9 and 3 proteases in MOLT-4 cells. Sequential activation indicated that the cleavage of caspase-8 and 9 precedes those of caspase-3. CONCLUSION: The results suggest that MPA induces the apoptotic death of MOLT-4 lymphocytes via the activations of caspase family proteases and the depletion of GTP.

Effects of flavonoids on myocardial apoptosis / 中国药理学通报

Aim To observe the effects of flavonoids,including galangin(G),kaempferol(K),apigenin(A),morin(M),quercetin(Q) and myricetin(MY),on myocardial apoptosis induced by H2O2,and explore the possible mechanism.Methods Primary cultured cardiocytes of neonatal rat were randomly divided into normal group,model group,and flavonoids group.Fluorescent staining,electrophoresis and Western-blot were employed to observe the cardiocyte apoptosis and proteins expression.Results Exposure to 100 ?mol?L-1 H2O2 for 16 h resulted in myocardial apoptosis significantly(P