scholarly journals Exendin-4 Protects MIN6 Cells from t-BHP-Induced Apoptosis via IRE1-JNK-Caspase-3 Signaling

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Wen-Jia Chen ◽  
Lin-Xi Wang ◽  
Yan-Ping Wang ◽  
Zhou Chen ◽  
Xiao-Ying Liu ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Caspase 3 ◽  
Transmembrane Protein ◽  
Annexin V ◽  
Flow Cytometric Assay ◽  
Flow Cytometric ◽  
Tert Butyl Hydroperoxide ◽  
Microscopy Analysis ◽  
Induced Apoptosis ◽  
Fluorescence Microscopy Analysis

Objectives.This study aimed to explore the effect of exendin-4 on t-BHP-induced apoptosis in pancreaticβcells and the mechanism of action.Methods.Murine MIN6 pancreaticβcells were treated with exendin-4 in the presence or absence of tert-butyl hydroperoxide (t-BHP). Cell survival was assessed by MTT staining. The percentage of apoptotic cells was determined by fluorescence microscopy analysis after Hoechst/PI staining and flow cytometric assay after Annexin V-FITC/PI staining. The activity of caspase-3 was determined using a caspase-3 activity kit. Expression of P-IRE1α, IRE1α, C-Jun N-terminal kinase (JNK), P-JNK, C-JUN, and P-C-JUN was detected by western blotting.Results.Exendin-4 was found to inhibit t-BHP-induced apoptosis in pancreaticβ-cells by downregulating caspase-3 activity. Exendin-4 also inhibited the endoplasmic reticulum transmembrane protein IRE1, the apoptosis-related signaling molecule JNK, and c-Jun activation.Conclusions.Our findings suggest that exendin-4 ultimately reduces t-BHP-inducedβ-cell apoptosis. IRE1-JNK-c-Jun signaling is involved in the exendin-4-mediated modulation ofβ-cell apoptosis.

scholarly journals Dihydrochalcone Derivative Induces Breast Cancer Cell Apoptosis via Intrinsic, Extrinsic, and ER Stress Pathways but Abolishes EGFR/MAPK Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Wasitta Rachakhom ◽  
Patompong Khaw-on ◽  
Wilart Pompimon ◽  
Ratana Banjerdpongchai
Keyword(s):  
Breast Cancer ◽  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Mapk Pathway ◽  
Annexin V ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Mcf 7

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.

Crambene induces pancreatic acinar cell apoptosis via the activation of mitochondrial pathway

2006 ◽  
Vol 291 (1) ◽  
pp. G95-G101 ◽  
Author(s):  
Yang Cao ◽  
Sharmila Adhikari ◽  
Abel Damien Ang ◽  
Marie Véronique Clément ◽  
Matthew Wallig ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Annexin V ◽  
Acinar Cells ◽  
Mitochondrial Pathway ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Pancreatic Acini

We investigated the apoptotic pathway activated by crambene (1-cyano-2-hydroxy-3-butene), a plant nitrile, on pancreatic acinar cells. As evidenced by annexin V-FITC staining, crambene treatment for 3 h induced the apoptosis but not necrosis of pancreatic acini. Caspase-3, -8, and -9 activities in acini treated with crambene were significantly higher than in untreated acini. Treatment with caspase-3, -8, and -9 inhibitors inhibited annexin V staining, as well as caspase-3 activity, pointing to an important role of these caspases in crambene-induced acinar cell apoptosis. The mitochondrial membrane potential was collapsed, and cytochrome c was released from the mitochondria in crambene-treated acini. Neither TNF-α nor Fas ligand levels were changed in pancreatic acinar cells after crambene treatment. These results provide evidence for the induction of pancreatic acinar cell apoptosis in vitro by crambene and suggest the involvement of mitochondrial pathway in pancreatic acinar cell apoptosis.

Multiple Signal Pathways Involved in Crocetin-Induced Apoptosis in KYSE-150 Cells

Pharmacology ◽  
2019 ◽  
Vol 103 (5-6) ◽  
pp. 263-272 ◽  
Author(s):  
Sheng Li ◽  
Yuhua Qu ◽  
Xiu-Yin Shen ◽  
Ting Ouyang ◽  
Wen-Bin Fu ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Squamous Carcinoma ◽  
Annexin V ◽  
Signal Pathways ◽  
Dependent Manner ◽  
Apoptosis Pathway ◽  
Anticancer Properties ◽  
Multiple Signal ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Background: Crocetin is a carotenoid extracted from the traditional Chinese medical herb saffron. Previous studies have demonstrated that crocetin possesses anticancer properties that are effective against various cancers. As an extension of our earlier study, the present study explored the underlying mechanisms in crocetin’s anticancer effect on KYSE-150 cells. The phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT), Mitogen-activated protein kinases (MAPK), and p53/p21 signal pathways play an important role in carcinogenesis, progression, and metastasis of carcinoma cells. Thus, we investigated crocetin’s effects on the PI3K/AKT, MAPK, and p53/p21 pathways in esophageal squamous carcinoma cell line KYSE-150 cells. Methods: KYSE-150 cells were treated with various concentrations of crocetin. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltertrazolium bromide assay, Annexin V/PI stain as well as Rh123 stain were used to evaluate the cell viability, apoptosis, and MMP. Western blot was used to detect the expression of PI3K, AKT, ERK1/2, p38, c-Jun NH-terminal kinase (JNK), P53, P21, Bcl-2, Bax, and cleaved caspase-3, which were associated with cell proliferation and apoptosis. Results: Our results showed that crocetin significantly inhibited the proliferation of KYSE-150 cells in a dose- and time-dependent manner. Crocetin also markedly induced cell apoptosis. Furthermore, we have found that crocetin not only inhibited the activation of PI3K/AKT, extracellular signal–regulated kinase-1/2 (ERK1/2), and p38 but also upregulated the p53/p21 level. These regulations ultimately triggered the mitochondrial-mediated apoptosis pathway with an eventual disruption of MMP, increased levels of Bax and cleaved caspase-3, and decreased levels of Bcl-2. Conclusions: These findings suggested that crocetin interfered with multiple signal pathways in KYSE-150 cells. Therefore, this study suggested that crocetin could potentially be used as a therapeutic candidate for the treatment of esophageal cancer.

scholarly journals Nodal induces apoptosis through activation of the ALK7 signaling pathway in pancreatic INS-1 β-cells

2012 ◽  
Vol 303 (1) ◽  
pp. E132-E143 ◽  
Author(s):  
Fang Zhao ◽  
Fengjie Huang ◽  
Mengxiong Tang ◽  
Xiaoming Li ◽  
Nina Zhang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Biological Effects ◽  
Cell Mass ◽  
Type I ◽  
Β Cells ◽  
Β Cell ◽  
Akt Phosphorylation ◽  
Induced Apoptosis

We demonstrated previously that the activation of ALK7 (activin receptor-like kinase-7), a member of the type I receptor serine/threonine kinases of the TGF-β superfamily, resulted in increased apoptosis and reduced proliferation through suppression of Akt signaling and the activation of Smad2-dependent signaling pathway in pancreatic β-cells. Here, we show that Nodal activates ALK7 signaling and regulates β-cell apoptosis. We detected Nodal expression in the clonal β-cell lines and rodent islet β-cells. Induction of β-cell apoptosis by treatment with high glucose, palmitate, or cytokines significantly increased Nodal expression in clonal INS-1 β-cells and isolated rat islets. The stimuli induced upregulation of Nodal expression levels were associated with elevation of ALK7 protein and enhanced phosphorylated Smad3 protein. Nodal treatment or overexpression of Nodal dose- or time-dependently increased active caspase-3 levels in INS-1 cells. Nodal-induced apoptosis was associated with decreased Akt phosphorylation and reduced expression level of X-linked inhibitor of apoptosis (XIAP). Remarkably, overexpression of XIAP or constitutively active Akt, or ablation of Smad2/3 activity partially blocked Nodal-induced apoptosis. Furthermore, siRNA-mediated ALK7 knockdown significantly attenuated Nodal-induced apoptosis of INS-1 cells. We suggest that Nodal-induced apoptosis in β-cells is mediated through ALK7 signaling involving the activation of Smad2/3-caspase-3 and the suppression of Akt and XIAP pathways and that Nodal may exert its biological effects on the modulation of β-cell survival and β-cell mass in an autocrine fashion.

Fenretinide (4HPR) Inhibits Growth of Myeloma Cells in Their Microenvironment and Is a Potent Inhibitor of Angiogenesis and Osteoclastogenesis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3480-3480
Author(s):  
Xin Li ◽  
Wen Ling ◽  
Rinku Saha ◽  
Paul Perkins ◽  
Angela Pennisi ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Mtt Assay ◽  
Cell Apoptosis ◽  
Mononuclear Cells ◽  
Annexin V ◽  
Dependent Manner ◽  
Angiogenic Potential ◽  
Inhibition Of Angiogenesis ◽  
Induced Apoptosis

Abstract Fenretinide (4HPR) is a relatively safe neoclassical retinoid analog that inhibits growth of various tumors through increased intracellular ceramide and ROS, induction of tumor cell apoptosis and inhibition of angiogenesis. 4HPR has been successfully tested as a chemopreventive and chemotherapeutic agent in clinical trials on various malignancies. In contrast to retinoic acid, 4HPR induces cell apoptosis rather than differentiation and shows synergistic responses with chemotherapeutic drugs in different tumor cell types. The biological effect and therapeutic value in multiple myeloma (MM) has not been investigated. The aim of this study was to investigate the anti-MM effect and mechanism of action of 4HPR using 3 stroma-dependent and 2 stroma-independent MM cell lines established in our laboratory, CD138-selected primary MM cells and co-culture systems of these cells with human osteoclasts and mesenchymal stem cells (MSCs) as previously described (Yaccoby et al., Cancer Res 2004). MM cell apoptosis detected by annexin V flow cytometry and TUNNEL, tumor growth by MTT assay, changes in caspase 3, 8 and 9 activity using Western blotting and ROS production by 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) dye assay. 4HPR inhibits growth of all tested MM cells in a dose- and time-dependent manner. The IC50 after 48 hrs in serum-containing media was 10 μM using MTT assay. 4HPR (3 μM) increased percent of apoptotic MM cells by 2.5±0.4 folds (p<0.01). Co-culture of these cell lines with osteoclasts only partially protected MM cells from the proapoptotic effect of this drug. Furthermore, 4HPR also induced apoptosis of primary CD138-selected MM cells co-cultured with osteoclasts or MSCs, and inhibited growth of bortezomib-resistant MM cell lines. In contrast, 4HPR had only minimal cytotoxic effect on blood mononuclear cells and MSCs. The proapoptotic effect of 4HPR involved increased level of ROS by 2.55±0.67 folds in MM cells (p<0.01). We also detected reduced levels of procaspase and increased cleaved caspase 8, 9 and 3 within 24 hrs of incubation with this drug. Sphingosine-1 phosphate (S1P) partially protected MM cells from 4HPR-induced apoptosis suggesting that, as reported for other tumors, anti-MM mechanism of this drug involved increased intracellular ceramide. 4HPR significantly inhibited tube formation by HUVEC in a matrigel assay (p<0.0001), confirming its anti-angiogenic potential. This drug also effectively prevented formation of multinucleated osteoclasts in culture of human osteoclast precursors with RANKL and M-CSF (p<0.0001). Furthermore, mature osteoclasts viability as assessed by MTT assays was reduced following incubation with 3 μM 4HPR (p<0.0001). We conclude that 4HPR is a potent anti-MM agent, affecting growth of MM cells in their microenvironment directly through induction of apoptosis in mechanisms involving ROS, caspase and possibly ceramide, and indirectly through inhibition of angiogenesis and osteoclastogenesis. Our data also suggests that S1P, which is highly produced by activated platelets, is an important survival factor for MM cells. Study is underway to test anti-MM efficacy of 4HPR in the SCID-hu model for primary myeloma.

Iron-Overload Induces Apoptosis in Cardiomyocytes and Hepatocytes Via Mitochondrial/Caspase-3 Pathways.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1872-1872
Author(s):  
Mo Yang ◽  
Shing Chan ◽  
Yiu Fai Cheung ◽  
Shau Yin Ha ◽  
Godfrey ChiFung Chan
Keyword(s):  
Iron Overload ◽  
Protective Effect ◽  
Cell Viability ◽  
Caspase 3 ◽  
Annexin V ◽  
Apoptotic Cells ◽  
H9c2 Cells ◽  
Plot Analysis ◽  
Iron Treatment ◽  
Induced Apoptosis

Abstract Cardiomyopathy and liver damage due to iron-overload are the major complications in patients with beta-thalassaemia major. Iron-overload may induce apoptosis in cardiomyocytes and hepatic cells, and that TPO may exert protective effect on apoptosis of cardiomyocytes (Circulation, 2006). In this study, we demonstrated firstly that iron induced apoptosis in cardiomyocytes. Using H9C2 cells, we have shown that iron reduced cell viability in a dose-dependent manner (0.003–3 mM) (n=6). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.3 mM, 72 hrs) (n=6). The expression of active caspase-3 was significantly increased in iron-treated cells. Furthermore, iron treatment increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential (n=6). Secondly, we found that TPO exerted cardio-protective effect on iron-induced apoptosis. H9C2 cells were cultured in the presence of iron (0.3 mM) with or without TPO (5, 10, 20, 50, 100 ng/mL, 72 hrs). The cell viability was significantly increased with the treatment of TPO at 50 ng/mL and 100 ng/mL (n=4). Dot-plot analysis of annexin V/PI staining demonstrated that TPO (50 ng/mL) significantly reduced the population of apoptotic cells (n=6). Incubation with TPO also decreased the iron-induced caspase-3 expression (n=6). Flow cytometric dot-plot analysis of H9C2 cells also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO group (n=6). The population of phospho-Akt and Erk1/2 were also significantly increased after treatment by TPO (P&lt;0.05, n=4). Human liver cell line MIHA was also used as a cell model. We showed that iron-overload reduced cell viability in a dose-dependent manner (0.0375–0.6 mM) (n=7). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.15–0.6 mM) for 72 hrs (n=7). The expression of active caspase-3 was also significantly increased in iron-treated cells (n=5). We also found that TPO exerted proliferation effect on MIHA cell by activation of phospho-Akt. However, MIHA cells were cultured in the presence of iron (0.3 mM) with TPO (50 ng/mL, 72 hrs). The cell viability was not significantly increased with the treatment of TPO (n=5). Dot-plot analysis of annexin V/PI staining did not demonstrated that TPO reduced the population of apoptotic cells induced by iron-overload (n=5). Also, incubation with TPO did not decrease the iron-induced caspase-3 expression in these cells (n=5). Our findings suggest that iron-overload induces apoptosis in cardiomyocytes and hepatocytes via mitochondrial/caspase-3 pathways and that TPO might exert a protective effect on iron-overload induced apoptosis via the activation of Akt and Erk1/2 pathways in cardiomyocytes.

Targeting Aminopeptidases by Tosedostat (TST) (CHR2797), Alone and with LBH589, Induces Significant Cytotoxicity Against Human Multiple Myeloma (MM) Cells

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1847-1847
Author(s):  
Chirag Acharya ◽  
Mike Y Zhong ◽  
Daniel Tannenbaum ◽  
Michelle Chen ◽  
Matt Ma ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Caspase 3 ◽  
Combined Treatment ◽  
Single Agent ◽  
Annexin V ◽  
Novel Approach ◽  
Human Multiple Myeloma ◽  
Induced Apoptosis ◽  
G1 Cells

Abstract Abstract 1847 Aminopeptidases (AP) are necessary for the growth and development of malignant cells and have a selectively important role in the maintenance of intracellular amino acid (AA) levels in neoplastic cells. CHR2797 is a novel, low nanomolar inhibitor of the M1 family of AP, a group of metalloenzymes containing a central Zn2+ ion. CHR2797 has antiproliferative and apoptotic effects against MM in vitro by inducing the AA deprivation response (AADR). TST, an oral, chronically administered agent with a good safety profile has demonstrated activity in patients with relapsed/refractory AML and is currently under study as part of combination therapy for untreated elderly patients with AML. At the epigenetic regulatory level, Zn-dependent histone deacetylase (HDAC) cause the deacetylation of histone and non-histone cellular proteins which are critical for gene expression, inducing apoptosis and cell cycle arrest in cancer cells. LBH589 (Panobinostat) is an established pan-HDAC inhibitor with potent in vitro anti-cancer activity in many hematological malignancies. The clinical efficacy of Panobinostat is currently being studied in several Phase II/III clinical trials with particular promise seen in the treatment of MM. Here we examined the potential therapeutic effect of CHR2797, alone and with LBH589, against MM cells. Using MTS and CTG assays, CHR2797, at clinically achievable concentrations, decreased survival and proliferation in MM1S and IL-6-dependent ANBL6 cells, in the presence or absence of bone marrow stromal cells following 72 hours incubation. CHR2797 induces apoptosis in MM cells via activation of Caspase 3/7 and 9 but not Caspase 8. Significantly, CHR2797 (10 μM) induced apoptosis in patient MM cells, as seen by % of annexin V and PI from 22 + 1.5% to 39 + 2.3% after 48h incubation. Combined treatment with CHR2797 and LBH589 in MM cells (MM1S, ANBL6, and INA6) further reduced cell viability following 72 hour incubation when compared with CHR2797 treatment alone, as determined by CTG viability luminescent assay. Both drugs together also augmented growth inhibitory effects when compared with single agent alone, after 72 hours incubation followed by MTS assay. Importantly, the combination of both drugs increased caspase 3/7- & 9-mediated apoptosis than CHR2797 alone in these MM cells following 24h-treatment. Cell cycle analysis (CHR2797 at 1μM; LBH589 at 1 nM) showed an increased growth arrest in G0/G1 cells in MM1R cells treated with both drugs versus CHR2797 alone after 24 hours: 68.5±3.3% versus 36±2.5%. Furthermore, CHR2797 inhibited anti-apoptotic protein Mcl-1 in MM1R and U266 MM cells by immunoblottings. Combined treatment with CHR2797 and LBH589 further blocked Mcl-1 when compared with either treatment alone after 24 hours incubation. Together, these results show that the combination of CHR2797 and LBH589 enhanced anti-myeloma effects when compared with either drug alone. This combination, which also has the potential of being without overlapping clinical toxicities, provides a promising novel approach to anti-myeloma therapy. Disclosures: Singer: Cell Therapeutics, Inc: Employment, Equity Ownership. Richardson:Novartis: Membership on an entity's Board of Directors or advisory committees.

Angelica Polysaccharide and TPO Have a Protective Effect On Hcmv-Induced Apoptosis In Megakaryocytes

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3553-3553
Author(s):  
Mo Yang ◽  
Jian Liang Chen ◽  
Jie yu Ye ◽  
Su yi Li ◽  
En yu Liang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Protective Effect ◽  
Caspase 3 ◽  
Hcmv Infection ◽  
Annexin V ◽  
Angelica Sinensis ◽  
Control Group ◽  
Mock Control ◽  
Apoptotic Effect ◽  
Induced Apoptosis

Abstract Human cytomegalovirus (hCMV) infection is often associated with thrombocytopenia. Megakaryocytes may be one of the major sites of hCMV infection, then inducing this cell apoptosis. Angelica Sinensis (Danggui) is an important ingredient of many commonly used herbal Medicine for promoting blood production. Our previous study has showed that the hematopoietic effect of Angelica Sinensis is related to its constituent, angelica polysaccharide (APS) (Yang M et al, J Ethnopharma, 2009). This present study investigated the anti-apoptotic effect of APS and TPO on hCMV-induced apoptosis in megakaryocytes. Human bone marrow mononuclear cells (MNC) or megakaryocytic cell line CHRF-288-11 and hCMV AD169 strain were co-cultured in this study. hCMV significantly inhibited the formation of CFU-MK as shown in three different concentrations of viral infection groups (103, 104 and 105 pfu/ml), compared with blank control and mock control (n=10, P<0.05). hCMV also significantly inhibited the growth of CHRF cells in these three different concentrations after incubation for 3 days, which compared with control group (n=10, P<0.01). hCMV DNA and mRNA were also positively detected in CHRF cells and the cells of CFU-MK with IS-PCR and RT-PCR respectively, while it was negative in blank and mock control groups. We further studied the effect of APS and TPO on CFU-MK formation. Results showed that APS (50 ug/ml) like TPO (50 ng/ml) enhanced hCMV-reduced CFU-MK (P=0.05, n=6). CHRF cells were also analyzed by Annexin V/PI with flow cytometry at day 3 after infection with hCMV AD169. The percentage of apoptotic cells in group of 103 pfu/ml was 19.0 ± 2.0%; The group of 104 pfu/ml was 23.0 ± 1.5%; The group of 105 pfu/ml was 28.0 ± 3.0%. The control group was 2.0 ± 0.5%. The apoptotic cells were confirmed by morphologic observation. In addition, apoptotic signals from megakaryocytic surface, cytoplasma and mitochondria were detected in hCMV infected cells by flow cytometry with Caspase-3 and JC-1 assay. Compared to mock infection control at day 5, Annexin-V positive cells population increased by 58%; active caspase-3 signal increased by 120% in viable cell population; and cell population with damaged mitochondial membrane showed a 5-times increase. Moreover, the anti-apoptotic effect of APS and TPO on CHRF cells was also demonstrated by using Annexin-V assay. Our studies showed that hCMV induces the apoptosis in megakaryocytes via mitochondrial and caspase-3 signaling, and angelica polysaccharide (APS) like TPO has a protective effect on hCMV-induced apoptosis in these cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Autophagy Inhibition Enhances Apoptosis Induced by Dioscin in Huh7 Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Ming-Ju Hsieh ◽  
Shun-Fa Yang ◽  
Yih-Shou Hsieh ◽  
Tzy-Yen Chen ◽  
Hui-Ling Chiou
Keyword(s):  
Cell Apoptosis ◽  
Caspase 3 ◽  
Natural Food ◽  
Dependent Manner ◽  
Caspase Activation ◽  
Huh7 Cells ◽  
Dependent Cell ◽  
Induced Apoptosis ◽  
Dose Dependent ◽  
Autophagy Inhibition

Extensive research results support the application of herbal medicine or natural food as an augment during therapy for various cancers. However, the effect of dioscin on tumor cells autophagy has not been clearly clarified. In this study, the unique effects of dioscin on autophagy of hepatoma cells were investigated. Results found that dioscin induced caspase-3- and -9-dependent cell apoptosis in a dose-dependent manner. Moreover, inhibition of ERK1/2 phosphorylation significantly abolished the dioscin-induced apoptosis. In addition, dioscin triggered cell autophagy in early stages. With autophagy inhibitors to hinder the autophagy process, dioscin-induced cell apoptosis was significantly enhanced. An inhibition of caspase activation did not affect the dioscin-induced LC3-II protein expression. Based on the results, we believed that while apoptosis was blocked, dioscin-induced autophagy process also diminished in Huh7 cells. In conclusion, this study indicates that dioscin causes autophagy in Huh7 cells and suggests that dioscin has a cytoprotective effect.

scholarly journals Voruciclib, an Oral, Selective CDK9 Inhibitor, Enhances Cell Death Induced By the Bcl-2 Selective Inhibitor Venetoclax in Acute Myeloid Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1361-1361 ◽  
Author(s):  
Daniel A Luedtke ◽  
Yongwei Su ◽  
Holly Edwards ◽  
Lisa Polin ◽  
Juiwanna Kushner ◽  
...  
Keyword(s):  
Cell Lines ◽  
Myeloid Leukemia ◽  
Caspase 3 ◽  
Combination Index ◽  
Survival Rates ◽  
Annexin V ◽  
Antileukemic Activity ◽  
Induction Of Apoptosis ◽  
Induced Apoptosis

Abstract Introduction: Patients with acute myeloid leukemia (AML) face overall 5-year survival rates of 65% and 27% for children and adults, respectively, leaving significant room for improvement. Relapse remains a major contributor to such low overall survival rates, and leukemic stem cells (LSCs) that survive treatment are believed to be responsible for AML relapse. The anti-apoptotic protein Bcl-2 is overexpressed in bulk AML cells and LSCs and is associated with poor clinical outcomes. Thus, Bcl-2 represents a promising therapeutic target for the treatment of AML. Venetoclax (ABT-199) is a selective Bcl-2 inhibitor that has shown great potential for treating a number of malignancies, including AML. Venetoclax inhibits Bcl-2, preventing it from sequestering pro-apoptotic Bcl-2 family protein Bim, leading to Bim activated Bax/Bak, resulting in apoptosis. However, Mcl-1 can also sequester Bim and prevent apoptosis. We previously showed that directly targeting Mcl-1 can enhance the antileukemic activity of venetoclax (Luedtke DA, et al. Signal Transduct Target Ther. Apr 2017). Alternatively, we proposed that indirect targeting of Mcl-1 may preserve or enhance the antileukemic activity of venetoclax, and prevent resistance resulting from Mcl-1. It has been reported that inhibition of CDK9 can downregulate cell survival genes regulated by superenhancers, including Mcl-1, MYC, and Cyclin D1. One CDK9 inhibitor in clinical development, flavopiridol (alvocidib), has progressed to phase II clinical trials in AML. However, off target effects and dose-limiting toxicities remain a concern. Voruciclib is an oral, selective CDK inhibitor differentiated by its potent inhibition of CDK9 as compared to other CDK inhibitors. This selectivity may potentially circumvent toxicities resulting from inhibition of non-CDK targets like MAK and ICK that are inhibited by flavopiridol. Voruciclib has been shown in vitro to promote apoptosis and decrease Mcl-1 expression levels in chronic lymphocytic leukemia (CLL) cells (Paiva C, et al. PLOS One. Nov 2015) and inhibit tumor growth in mouse xenograft models of diffuse large B-cell lymphoma (DLBCL) in combination with venetoclax (Dey J. et al Scientific Reports. Dec 2017). Based on these data, voruciclib may downregulate Mcl-1 in AML cells and therefore synergistically enhance the antileukemic activity of venetoclax. Methods/Results: Culturing AML cell lines (THP-1, U937, MOLM-13, MV4-11, and OCI-AML3) and primary patient samples with various concentrations of voruciclib resulted in a concentration-dependent increase in Annexin V+ cells (2 μM voruciclib induced 13.8-55.8% Annexin V+ cells) along with increased levels of cleaved caspase 3 and PARP, demonstrating that voruciclib induces apoptosis in AML cells. Next, we tested the combination of voruciclib and venetoclax in AML cell lines and primary AML patient samples at clinically achievable concentrations. Annexin V/PI staining, flow cytometry analysis, and combination index calculation (using CalcuSyn software) revealed synergistic induction of apoptosis by voruciclib and venetoclax combination (combination index values for MV4-11, U937, THP-1, and MOLM-13 cells were <0.73; treatment with 2 µM voruciclib and venetoclax for 24 h resulted in >80% apoptosis). Importantly, synergy was observed in both venetoclax sensitive and resistant cell lines. This was accompanied by increased cleavage of caspase 3 and PARP. Lentiviral shRNA knockdown of Bak and Bax partially rescued AML cells from voruciclib-induced apoptosis, showing that voruciclib induces apoptosis at least partially through the intrinsic apoptosis pathway. However, Bak and Bax knockdown had little to no effect on induction of apoptosis by the combination treatment, indicating that there might be other molecular mechanisms underlying the synergistic interaction between the two agents. Treatment with the pan-caspase inhibitor Z-VAD-FMK partially rescued cells from combination treatment induced-apoptosis. Discussion: Collectively, these results demonstrate that voruciclib and venetoclax synergistically induce apoptosis in AML cells in vitro and reverse venetoclax resistance. Further studies to determine the mechanism of action and in vivo efficacy of this promising combination in AML xenografts and PDX models are underway. Disclosures Ge: MEI Pharma: Research Funding.

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