PI3 Kinase Inhibition Induces Apoptotic Cell Death in Acute Lymphoblastic Leukemia Via the Mitochondrial Pathway.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1911-1911
Author(s):  
Karin von Schwarzenberg ◽  
Marco Henkel ◽  
Dennis Conzelmann ◽  
Björn Stork ◽  
Anita Bringmann ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Lymphoblastic Leukemia ◽  
Death Receptor ◽  
Pi3k Pathway ◽  
Apoptotic Cell Death ◽  
Jurkat Cells ◽  
Parp Cleavage ◽  
Caspase 9 ◽  
Pi3k Inhibition

Abstract The phosphatidylinositol 3-kinase (PI3K) pathway regulates many cellular processes that are involved in tumor progression. Aberrant activation of the PI3K pathway due to an alteration of its elements like PTEN or Akt occurs quite frequently in malignant cells. Thus, inhibition of this pathway represents a promising option for the treatment of cancer patients. The best characterized PI3K inhibitors are LY294002 and wortmannin that were shown to disrupt downstream signaling and induce apoptotic cell death in tumor cells. Acute lymphoblastic leukemia (ALL) is a malignancy mainly found in young children and elderly with constitutive activation of PI3K pathway. In our study we analyzed the effect of PI3K inhibition in cell lines deduced from ALL (Jurkat, BV173, SD1, T-2) and primary leukemic cells by incubating them with increasing concentrations of inhibitors of the PI3K signaling. We found that treatment of ALL cells with LY294002, the mTOR inhibitor rapamycin or Akt inhibitor SH5 induced apoptotic cell death that was accompanied by caspase-3 activation and PARP-cleavage and interfered with intracellular PI3K/Akt signaling as analyzed by phosphorylation and expression of mTOR or P70S6K. In line with these results apoptotic cell death could be inhibited by the pan-caspase inhibitor zVAD. In order to determine the pathway of apoptosis induction we took advantage of Jurkat cells (T-ALL) overexpressing or lacking molecules involved in apoptotic pathways such as FADD, an adaptor molecule recruited to the death receptor upon ligand binding, Caspase-8, Caspase-9 or Bcl-2, an anti-apoptotic protein that prevents the release of cytochrom c from mitochondria. PI3K inhibition by LY294002 induced apoptotic cell death in cells deficient of FADD or caspase-8 with no difference to wild type cells. In contrast, cells overexpressing Bcl2 or lacking caspase-9 were resistant to apoptotic death indicating that PI3-kinase inhibition is independent of the external death receptor signaling and is mediated via the mitochondrial pathway. These results were confirmed by analyzing PARP cleavage and caspase-3 activation in utilized leukemic cell lines. Furthermore, we found that the PI3K inhibitor LY294002 induced apoptosis in ALL cells that could be increased by the etoposide, a topoisomerase inhibitor, or TRAIL. In addition, in contrast to etoposide, treatment of ALL cells with TRAIL could overcome the resistance of ALL cells to PI3K inhibition even in caspase-9 deficient Jurkat cells. Our results provide an interesting approach in designing novel therapeutic strategies to target the PI3K pathway in ALL to overcome the resistance to cytotoxic agents.

Proinflammatory phenotype of coronary arteries promotes endothelial apoptosis in aging

2004 ◽  
Vol 17 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Anna Csiszar ◽  
Zoltan Ungvari ◽  
Akos Koller ◽  
John G. Edwards ◽  
Gabor Kaley
Keyword(s):  
Cell Death ◽  
Coronary Arteries ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
The Elderly ◽  
Apoptotic Cell Death ◽  
Caspase 9 ◽  
No Donor ◽  
Endothelial Apoptosis ◽  
Age Related

Previously we demonstrated that aging in coronary arteries is associated with proinflammatory phenotypic changes and decreased NO bioavailability, which, we hypothesized, promotes vascular disease by enhancing endothelial apoptosis. To test this hypothesis we characterized proapoptotic alterations in the phenotype of coronary arteries of aged (26 mo old) and young (3 mo old) F344 rats. DNA fragmentation analysis and TUNEL assay showed that in aged vessels there was an approximately fivefold increase in the number of apoptotic endothelial cells. In aged coronary arteries there was an increased expression of TNFα, TNFβ, and caspase 9 (microarray, real-time PCR), as well as increased caspase 9 and caspase 3 activity, whereas expression of TNFR1, TNFα-converting enzyme (TACE), Bcl-2, Bcl-X(L), Bid, Bax, caspase 8, and caspase 3 were unchanged. In vessel culture (18 h) incubation of aged coronary arteries with a TNF blocking antibody or the NO donor S-nitroso-penicillamine (SNAP) decreased apoptotic cell death. Incubation of young arteries with exogenous TNFα increased caspase 9 activity and elicited endothelial apoptosis, which was attenuated by SNAP. Inhibition of NO synthesis in cultured young coronary arteries also induced apoptotic cell death and potentiated the apoptotic effect of TNFα. Thus we propose that age-related upregulation of TNFα and caspase 9 and decreased bioavailability of NO promote endothelial apoptosis in coronary arteries that may lead to impaired endothelial function and ischemic heart disease in the elderly.

scholarly journals VANILLIN EXTRACTED FROM PROSO MILLET AND BARNYARD MILLET INDUCE APOPTOSIS IN HT-29 AND MCF-7 CELL LINE THROUGH MITOCHONDRIA MEDIATED PATHWAY

2017 ◽  
Vol 10 (12) ◽  
pp. 226 ◽  
Author(s):  
Deepa Priya Ramadoss ◽  
Nageswaran Sivalingam
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Barnyard Millet ◽  
Proso Millet ◽  
Ht 29 ◽  
Mcf 7

Objective: The main aim of the study was to investigate the bioactive compound vanillin extracted from proso millet (compound 1), and barnyard millet (compound 2) induces apoptotic cell death and whether it is mediated through mitochondrial pathway in HT-29 and MCF-7 cell line.Methods: The cells were treated with 250 μg/ml and 1000 μg/ml concentration of extracted vanillin for 48 hrs. Cytochrome c release and expression level of pro-apoptotic protein Bax and caspase-9 were detected by western blot analysis.Results: The results reveal that extracted compounds increased the release of cytochrome c and upregulating the expression of Bax and caspase-9 as concentration increases in a dose-dependent manner.Conclusion: The study suggests that the vanillin compound extracted from these millets induces apoptotic cell death through a mitochondria-dependent pathway.

scholarly journals Ginkgo biloba Prevents Oxidative Stress-Induced Apoptosis Blocking p53 Activation in Neuroblastoma Cells

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 279 ◽  
Author(s):  
Francesco Di Meo ◽  
Rossana Cuciniello ◽  
Sabrina Margarucci ◽  
Paolo Bergamo ◽  
Orsolina Petillo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Neurodegenerative Diseases ◽  
Ginkgo Biloba ◽  
Apoptotic Cell ◽  
Neuroblastoma Cells ◽  
Apoptotic Cell Death ◽  
Parp Cleavage ◽  
Egb 761 ◽  
Induced Apoptosis

Oxidative stress has been associated to neuronal cell loss in neurodegenerative diseases. Neurons are post-mitotic cells that are very sensitive to oxidative stress—especially considering their limited capacity to be replaced. Therefore, reduction of oxidative stress, and inhibiting apoptosis, will potentially prevent neurodegeneration. In this study, we investigated the neuroprotective effect of Ginkgo biloba extract (EGb 761) against H2O2 induced apoptosis in SK-N-BE neuroblastoma cells. We analysed the molecular signalling pathway involved in the apoptotic cell death. H2O2 induced an increased acetylation of p53 lysine 382, a reduction in mitochondrial membrane potential, an increased BAX/Bcl-2 ratio and consequently increased Poly (ADP-ribose) polymerase (PARP) cleavage. All these effects were blocked by EGb 761 treatment. Thus, EGb 761, acting as intracellular antioxidant, protects neuroblastoma cells against activation of p53 mediated pathway and intrinsic mitochondrial apoptosis. Our results suggest that EGb 761, protecting against oxidative-stress induced apoptotic cell death, could potentially be used as nutraceutical for the prevention and treatment of neurodegenerative diseases.

The AKT Inhibitor, A443654, Induces Cell Cycle Arrest, Apoptosis and Synergizes with Chemotherapeutic Drugs in Multi-Drug Resistant T-Cell Acute Lymphoblastic Leukemia - A Novel Agent for Therapy of Drug Resistant ALL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3344-3344
Author(s):  
James A. McCubrey ◽  
William L. Blalock ◽  
Pier Luigi Tazzari ◽  
Alessandra Cappellini ◽  
Ilaria Iacobucci ◽  
...  
Keyword(s):  
Cell Death ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Jurkat Cells ◽  
Drug Resistant ◽  
Akt Inhibitor ◽  
Cycle Arrest ◽  
Hematopoietic Precursor ◽  
Dose Dependent

Abstract The PI3K/Akt pathway is a key mediator of proliferation and survival; its constitutive activation is implicated in pathogenesis and progression of a wide variety of hematological malignancies. Constitutively-activated Akt is a common feature of the T-ALL cell lines (MOLT-4, Jurkat, CEM). Hyperactivity of Akt leads not only to their growth and resistance to apoptosis but also to drug-resistance. In this study, we sought to examine the potential of a novel Akt inhibitor, A443654, in the therapy of T-ALL. A443654 led to rapid cell death of CEM, Jurkat, and MOLT-4. All three lines were sensitive to nanomolar (nM) doses of A443654 (IC50=60 nM, 120 nM and 900 nM for MOLT-4, CEM, and Jurkat, respectively). Effects were dose dependent and resulted in G2/M arrest. Indeed, approximately 39% of Jurkat cells treated with A443654 were in G2/M whereas only 11% of the untreated cells were in G2/M. Cell cycle arrest was followed by apoptotic cell death as determined by annexin V-PI and trypan blue staining. Treatment of CEM and Jurkat cells led to de-phosphorylation of the downstream Akt substrate GSK-3beta. Treatment of Jurkat cells with A443654 resulted in activation of caspase-2, -3, -8, and -9. Apoptotic cell death was greatly reduced by caspase-3 and -9 selective inhibitors. Additionally, A443654 was shown to be highly effective against the drug-resistant cell line CEM-VBL100 (CEM-R), which overexpresses Pgp. This Akt inhibitor initially (1 to 4 hour treatments) decreased Pgp activity, but not protein levels, further documenting a link between Akt and Pgp activity. While CEM-R cells displayed decreased sensitivity to A443654, treatment of CEM-R cells with sub-lethal doses of A443654 for 24 hours, reduced the surface expression of Pgp. Moreover, A443654 synergized with the DNA damaging agent etoposide, a substrate of Ppg, in both drug sensitive and resistant lines. At etoposide concentrations between 25 mM to 100 mM, A443654 enhanced the extent of cell killing from 25% to 45%. We then confirmed the effect of A443654 on human leukemia samples using blasts from 6 patients with T-ALL, all of whom displayed constitutive Akt activation. In a dose dependent fashion, A443654 was able to induce apoptotic cell death of T-ALL blast cells, as indicated by flow cytometric analysis of samples immunostained for active (cleaved) caspase-3. In contrast, this Akt inhibitor was determined to be minimally cytotoxic on normal CD34+ hematopoietic precursor cells isolated from cord blood. Taken together, our findings indicate that the Akt inhibitor, A443654, either alone or in combination with existing drugs, may in the future be a useful therapeutic option for primary and refractory T-ALL displaying activated Akt signaling. Furthermore, this novel Akt inhibitor was effective in suppressing the growth of multidrug resistant ALL cells while having minimal effects on normal hematopoietic precursor cells documenting its poteintial in the treatment of drug resistant leukemias.

Hypoxia induces apoptosis via two independent pathways in Jurkat cells: differential regulation by glucose

2001 ◽  
Vol 281 (5) ◽  
pp. C1596-C1603 ◽  
Author(s):  
Ricky Malhotra ◽  
Zhiwu Lin ◽  
Claudius Vincenz ◽  
Frank C. Brosius
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Glucose Uptake ◽  
Molecular Mechanisms ◽  
Death Receptor ◽  
Jurkat Cells ◽  
Caspase 9 ◽  
Cytochrome C Release ◽  
Extracellular Glucose ◽  
Uptake And Metabolism

Glucose uptake and metabolism inhibit hypoxia-induced apoptosis in a variety of cell types, but the underlying molecular mechanisms remain poorly understood. In the present study, we explore hypoxia-mediated cell death pathways in Jurkat cells in the presence and absence of extracellular glucose. In the absence of extracellular glucose, hypoxia caused cytochrome c release, caspase 3 and poly(ADP-ribose)polymerase cleavage, and DNA fragmentation; this apoptotic response was blocked by the caspase 9 inhibitor z-LEHD-FMK. The presence of extracellular glucose during hypoxia prevented cytochrome c release and activation of caspase 9 but did not prevent apoptosis in Jurkat cells. In these conditions, overexpression of the caspase 8 inhibitor v-FLIP prevented hypoxia-mediated cell death. Thus hypoxia can stimulate two apoptotic pathways in Jurkat cells, one dependent on cytochrome c release from mitochondria that is prevented by glucose uptake and metabolism, and the other independent of cytochrome c release and resulting from activation of the death receptor pathway, which is accelerated by glucose uptake and metabolism.

scholarly journals CXCR4 Blockade By BL-8040 in T Cell Acute Lymphoblastic Leukemia Decreases Mitochondrial Mass and Induces Non-Apoptotic Cell Death

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2745-2745
Author(s):  
Jun Xia ◽  
Stephanie Sun ◽  
Matthew RM Jotte ◽  
Geoffrey L. Uy ◽  
Osnat Bohana-Kashtan ◽  
...  
Keyword(s):  
Cell Death ◽  
Apoptotic Cell ◽  
Lymphoblastic Leukemia ◽  
Apoptotic Cell Death ◽  
Employment Equity ◽  
Cxcr4 Signaling ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Equity Ownership

T cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy that accounts for 10-15% of pediatric and 25% of adult ALL cases. CXCL12 is a CXC chemokine that is constitutively expressed at high levels in the bone marrow. CXCR4 is the major receptor for CXCL12 and is by far the most highly expressed chemokine receptor on T-ALL cells. Two groups recently showed that genetic loss of CXCR4 signaling in murine or human T-ALL cells markedly suppressed their growth in vivo. We previously reported that BL-8040, a potent new CXCR4 antagonist with sustained receptor occupancy, is active as monotherapy against T-ALL in mice. Indeed, a 2-week course of daily BL-8040 resulted in a median reduction in tumor burden of 32.1-fold (range 6.8 to 176) across 5 different T-ALL xenografts. Preliminary data from a clinical trial of BL-8040 plus nelarabine for relapsed T-ALL also suggest therapeutic activity, with a complete remission rate observed in 4/8 patients (50%), which compares favorably to published response rates of approximately 30% with single agent nelarabine. Here, we explore molecular mechanisms by which CXCR4 blockade induces T-ALL death. NOD-scid IL2Rgammanull (NSG) mice were injected with P12-Ichikawa cells, a T-ALL cell line modified to express click beetle red luciferase and GFP. Following T-ALL engraftment, mice were treated with a single dose of BL-8040, and then leukemic cells in the bone marrow harvested 24-48 hours later. Treatment with BL-8040 resulted in a marked suppression of Akt and Erk1/2 phosphorylation, suggesting that signaling through CXCR4 is the major source of PI3 kinase pathway activation in T-ALL cells. Surprisingly, treatment with BL-8040 did not affect cellular proliferation, as measured by Ki67/FxCycle Violet staining or by EdU labeling. Moreover, no increase in apoptosis, as measured by annexin V or activated caspase 3 expression, was observed. These data suggest that CXCR4 blockade induces a non-apoptotic cell death. To explore this possibility further, we performed transcriptome sequencing on T-ALL cells recovered from mice 24 hours after 1 dose of BL-8040. A total of 151 differentially expressed genes (FDR of < 0.05% and ≥ 2-fold change) were identified. Gene set enrichment analysis was strongly positive for alterations in oxidative phosphorylation, ribosome biogenesis, and carbohydrate metabolism. Ribosome function was assessed using O-propargyl-puromycin (OPP), which monitors global protein translation. No difference in global protein synthesis in T-ALL cells was observed after CXCR4 blockade in vivo. T-ALL cells are dependent on glutamine as a source of carbon, and PI3 kinase signaling positively regulates glutaminolysis. Thus, we hypothesized that CXCR4 blockade may induce T-ALL cell death by reducing glutamine metabolism. However, treatment of T-ALL cells in vitro with BL-8040 did not alter the cellular levels of glutamine or glutamate, as measured using a commercial bioluminescent assay. Confirmatory metabolic tracing studies using 13C-labeled glutamine and glucose are in progress. Finally, to explore the reduction in oxidative phosphorylation, we examined mitochondria function using Mitotracker Green. Treatment of T-ALL cells in vitro with BL-8040 for 24-48 hours induced a significant decrease in mitochondria number, suggesting induction of mitophagy. Collectively, these data suggest that T-ALL cells are addicted to CXCR4 signaling in vivo. CXCR4 blockade with BL-8040 induces a non-apoptotic cell death that is characterized by a loss of mitochondria. Disclosures Uy: Astellas: Consultancy; Pfizer: Consultancy; Curis: Consultancy; GlycoMimetics: Consultancy. Bohana-Kashtan:BiolineRx: Employment, Equity Ownership. Sorani:BiolineRx: Employment, Equity Ownership. Vainstein:BiolineRx: Employment, Equity Ownership.

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