scholarly journals Mitochondrial Targeting Involving Cholesterol-Rich Lipid Rafts in the Mechanism of Action of the Antitumor Ether Lipid and Alkylphospholipid Analog Edelfosine

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 763
Author(s):  
Faustino Mollinedo ◽  
Consuelo Gajate
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Lipid Rafts ◽  
Atp Synthase ◽  
Ether Lipid ◽  
Antitumor Action ◽  
Mitochondrial Targeting ◽  
F1fo Atp Synthase ◽  
Induced Apoptosis

The ether lipid edelfosine induces apoptosis selectively in tumor cells and is the prototypic molecule of a family of synthetic antitumor compounds collectively known as alkylphospholipid analogs. Cumulative evidence shows that edelfosine interacts with cholesterol-rich lipid rafts, endoplasmic reticulum (ER) and mitochondria. Edelfosine induces apoptosis in a number of hematological cancer cells by recruiting death receptors and downstream apoptotic signaling into lipid rafts, whereas it promotes apoptosis in solid tumor cells through an ER stress response. Edelfosine-induced apoptosis, mediated by lipid rafts and/or ER, requires the involvement of a mitochondrial-dependent step to eventually elicit cell death, leading to the loss of mitochondrial membrane potential, cytochrome c release and the triggering of cell death. The overexpression of Bcl-2 or Bcl-xL blocks edelfosine-induced apoptosis. Edelfosine induces the redistribution of lipid rafts from the plasma membrane to the mitochondria. The pro-apoptotic action of edelfosine on cancer cells is associated with the recruitment of F1FO–ATP synthase into cholesterol-rich lipid rafts. Specific inhibition of the FO sector of the F1FO–ATP synthase, which contains the membrane-embedded c-subunit ring that constitutes the mitochondrial permeability transcription pore, hinders edelfosine-induced cell death. Taking together, the evidence shown here suggests that the ether lipid edelfosine could modulate cell death in cancer cells by direct interaction with mitochondria, and the reorganization of raft-located mitochondrial proteins that critically modulate cell death or survival. Here, we summarize and discuss the involvement of mitochondria in the antitumor action of the ether lipid edelfosine, pointing out the mitochondrial targeting of this drug as a major therapeutic approach, which can be extrapolated to other alkylphospholipid analogs. We also discuss the involvement of cholesterol transport and cholesterol-rich lipid rafts in the interactions between the organelles as well as in the role of mitochondria in the regulation of apoptosis in cancer cells and cancer therapy.

scholarly journals Direct Endoplasmic Reticulum Targeting by the Selective Alkylphospholipid Analog and Antitumor Ether Lipid Edelfosine as a Therapeutic Approach in Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 4173
Author(s):  
Faustino Mollinedo ◽  
Consuelo Gajate
Keyword(s):  
Pancreatic Cancer ◽  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Apoptotic Cell ◽  
Ether Lipid ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, shows a dismal and grim overall prognosis and survival rate, which have remained virtually unchanged for over half a century. PDAC is the most lethal of all cancers, with the highest mortality-to-incidence ratio. PDAC responds poorly to current therapies and remains an incurable malignancy. Therefore, novel therapeutic targets and drugs are urgently needed for pancreatic cancer treatment. Selective induction of apoptosis in cancer cells is an appealing approach in cancer therapy. Apoptotic cell death is highly regulated by different signaling routes that involve a variety of subcellular organelles. Endoplasmic reticulum (ER) stress acts as a double-edged sword at the interface of cell survival and death. Pancreatic cells exhibit high hormone and enzyme secretory functions, and thereby show a highly developed ER. Thus, pancreatic cancer cells display a prominent ER. Solid tumors have to cope with adverse situations in which hypoxia, lack of certain nutrients, and the action of certain antitumor agents lead to a complex interplay and crosstalk between ER stress and autophagy—the latter acting as an adaptive survival response. ER stress also mediates cell death induced by a number of anticancer drugs and experimental conditions, highlighting the pivotal role of ER stress in modulating cell fate. The alkylphospholipid analog prototype edelfosine is selectively taken up by tumor cells, accumulates in the ER of a number of human solid tumor cells—including pancreatic cancer cells—and promotes apoptosis through a persistent ER-stress-mediated mechanism both in vitro and in vivo. Here, we discuss and propose that direct ER targeting may be a promising approach in the therapy of pancreatic cancer, opening up a new avenue for the treatment of this currently incurable and deadly cancer. Furthermore, because autophagy acts as a cytoprotective response to ER stress, potentiation of the triggering of a persistent ER response by combination therapy, together with the use of autophagy blockers, could improve the current gloomy expectations for finding a cure for this type of cancer.

scholarly journals Caspase-8 deficiency induces a switch from TLR3 induced apoptosis to lysosomal cell death in neuroblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marie-Anaïs Locquet ◽  
Gabriel Ichim ◽  
Joseph Bisaccia ◽  
Aurelie Dutour ◽  
Serge Lebecque ◽  
...  
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Neuroblastoma Cell ◽  
Death Receptor ◽  
Neuroblastoma Cell Line ◽  
Caspase 8 ◽  
Caspase Activation ◽  
Extrinsic Pathway ◽  
Lysosomal Membrane Permeabilization ◽  
Induced Apoptosis

AbstractIn cancer cells only, TLR3 acquires death receptor properties by efficiently triggering the extrinsic pathway of apoptosis with Caspase-8 as apical protease. Here, we demonstrate that in the absence of Caspase-8, activation of TLR3 can trigger a form of programmed cell death, which is distinct from classical apoptosis. When TLR3 was activated in the Caspase-8 negative neuroblastoma cell line SH-SY5Y, cell death was accompanied by lysosomal permeabilization. Despite caspases being activated, lysosomal permeabilization as well as cell death were not affected by blocking caspase-activity, positioning lysosomal membrane permeabilization (LMP) upstream of caspase activation. Taken together, our data suggest that LMP with its deadly consequences represents a “default” death mechanism in cancer cells, when Caspase-8 is absent and apoptosis cannot be induced.

scholarly journals Antidepressant Drug Enhanced Trail Receptor-2 Expression and Sensitized Lung Cancer Cells to Trail-Induced Apoptosis via Inhibition of Autophagic Flux

2020 ◽  
Author(s):  
K.M.A. Zinnah ◽  
Jae-Won Seol ◽  
Sang-Youel Park
Keyword(s):  
Lung Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Antidepressant Drug ◽  
Lung Cancer Cells ◽  
Autophagic Flux ◽  
Trail Receptor ◽  
Treatment Needs ◽  
Induced Apoptosis ◽  
Autophagy Inhibition

Autophagy, an alternative cell death mechanism, is also termed programmed cell death type II. Autophagy in cancer treatment needs to be regulated. In our study, autophagy inhibition by desipramine or the autophagy inhibitor chloroquine (CQ) enhanced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-2 [death receptor (DR5)] expression and subsequently TRAIL-induced apoptosis in TRAIL-resistant A549 lung cancer cells. Genetic inhibition of DR5 substantially reduced desipramine-enhanced TRAIL-mediated apoptosis, proving that DR5 was required to increase TRAIL sensitivity in TRAIL-resistant cancer cells. Desipramine treatment upregulated p62 expression and promoted conversion of light chain 3 (LC3)-I to its lipid-conjugated form, LC3-II, indicating that autophagy inhibition occurred at the final stages of autophagic flux. Transmission electron microscopy analysis showed the presence of condensed autophagosomes, which resulted from the late stages of autophagy inhibition by desipramine. TRAIL, in combination with desipramine or CQ, augmented the expression of apoptosis-related proteins cleaved caspase-8 and cleaved caspase-3. Our results contributed to the understanding of the mechanism underlying the synergistic anti-cancer effect of desipramine and TRAIL and presented a novel mechanism of DR5 upregulation. These findings demonstrated that autophagic flux inhibition by desipramine potentiated TRAIL-induced apoptosis, suggesting that appropriate regulation of autophagy is required for sensitizing TRAIL-resistant cancer cells to TRAIL-mediated apoptosis.

BH3-only proteins are essential initiators of programmed cell death and stress-induced apoptosis in normal and cancer cells

2008 ◽  
Vol 6 (9) ◽  
pp. 6
Author(s):  
A. Strasser ◽  
A. Villunger ◽  
P. Bouillet ◽  
E.M. Michalak ◽  
L.A. O'Reilly ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Cancer Cells ◽  
Induced Apoptosis

Attenuation of the hypoxia-induced protein kinase Cδ interaction with the ‘d’ subunit of F1Fo-ATP synthase in neonatal cardiac myocytes: implications for energy preservation and survival

2010 ◽  
Vol 429 (2) ◽  
pp. 335-345 ◽  
Author(s):  
Tiffany T. Nguyen ◽  
Mourad Ogbi ◽  
Qilin Yu ◽  
John A. Johnson
Keyword(s):  
Protein Kinase ◽  
Atpase Activity ◽  
Atp Synthase ◽  
Mitochondrial Targeting ◽  
F1fo Atp Synthase ◽  
Hiv Tat ◽  
F1fo Atpase ◽  
D Subunit ◽  
Mitochondrial Targeting Sequences ◽  
Protein Kinase Cδ

The F1Fo-ATP synthase provides most of the heart's energy, yet events that alter its function during injury are poorly understood. Recently, we described a potent inhibitory effect on F1Fo-ATP synthase function mediated by the interaction of PKCδ (protein kinase Cδ) with dF1Fo (‘d’ subunit of the F1Fo-ATPase/ATP synthase). We have now developed novel peptide modulators which facilitate or inhibit the PKCδ–dF1Fo interaction. These peptides include HIV-Tat (transactivator of transcription) protein transduction and mammalian mitochondrial-targeting sequences. Pre-incubation of NCMs (neonatal cardiac myocyte) with 10 nM extracellular concentrations of the mitochondrial-targeted PKCδ–dF1Fo interaction inhibitor decreased Hx (hypoxia)-induced co-IP (co-immunoprecipitation) of PKCδ with dF1Fo by 40±9%, abolished Hx-induced inhibition of F1Fo-ATPase activity, attenuated Hx-induced losses in F1Fo-derived ATP and protected against Hx- and reperfusion-induced cell death. A scrambled-sequence (inactive) peptide, which contained HIV-Tat and mitochondrial-targeting sequences, was without effect. In contrast, the cell-permeant mitochondrial-targeted PKCδ–dF1Fo facilitator peptide, which we have shown previously to induce the PKCδ–dF1Fo co-IP, was found to inhibit F1Fo-ATPase activity to an extent similar to that caused by Hx alone. The PKCδ–dF1Fo facilitator peptide also decreased ATP levels by 72±18% under hypoxic conditions in the presence of glycolytic inhibition. None of the PKCδ–dF1Fo modulatory peptides altered the inner mitochondrial membrane potential. Our studies provide the first evidence that disruption of the PKCδ–dF1Fo interaction using cell-permeant mitochondrial-targeted peptides attenuates cardiac injury resulting from prolonged oxygen deprivation.

scholarly journals Isoflavones Isolated from the Seeds of Millettia ferruginea Induced Apoptotic Cell Death in Human Ovarian Cancer Cells

Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 207 ◽  
Author(s):  
Yi-Yue Wang ◽  
Jun Hyeok Kwak ◽  
Kyung-Tae Lee ◽  
Tsegaye Deyou ◽  
Young Pyo Jang ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Ovarian Cancer Cells ◽  
Human Ovarian Cancer ◽  
Millettia Ferruginea ◽  
Induced Apoptosis

The seeds of Millettia ferruginea are used in fishing, pesticides, and folk medicine in Ethiopia. Here, the anti-cancer effects of isoflavones isolated from M. ferruginea were evaluated in human ovarian cancer cells. We found that isoflavone ferrugone and 6,7-dimethoxy-3’,4’-methylenedioxy-8-(3,3-dimethylallyl)isoflavone (DMI) had potent cytotoxic effects on human ovarian cancer cell A2780 and SKOV3. Ferrugone and DMI treatment increased the sub-G1 cell population in a dose-dependent manner in A2780 cells. The cytotoxic activity of ferrugone and DMI was associated with the induction of apoptosis, as shown by an increase in annexin V-positive cells. Z-VAD-fmk, a broad-spectrum caspase inhibitor, and z-DEVD-fmk, a caspase-3 inhibitor, significantly reversed both the ferrugone and DMI-induced apoptosis, suggesting that cell death stimulated by the isoflavones is mediated by caspase-3-dependent apoptosis. Additionally, ferrugone-induced apoptosis was found to be caspase-8-dependent, while DMI-induced apoptosis was caspase-9-dependent. Notably, DMI, but not ferrugone, increased the intracellular levels of reactive oxygen species (ROS), and antioxidant N-acetyl-L-cysteine (NAC) attenuated the pro-apoptotic activity of DMI. These data suggest that DMI induced apoptotic cell death through the intrinsic pathway via ROS production, while ferrugone stimulated the extrinsic pathway in human ovarian cancer cells.

scholarly journals A Novel Human Phosphatidylethanolamine-binding Protein Resists Tumor Necrosis Factor α-induced Apoptosis by Inhibiting Mitogen-activated Protein Kinase Pathway Activation and Phosphatidylethanolamine Externalization

2004 ◽  
Vol 279 (44) ◽  
pp. 45855-45864 ◽  
Author(s):  
Xiaojian Wang ◽  
Nan Li ◽  
Bin Liu ◽  
Hongying Sun ◽  
Taoyong Chen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Necrosis Factor ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Breast Cancer Cells ◽  
Tumor Necrosis ◽  
Induced Apoptosis ◽  
Phosphatidylethanolamine Binding Protein ◽  
Necrosis Factor ◽  
Mcf 7

The phosphatidylethanolamine (PE)-binding proteins (PEBPs) are an evolutionarily conserved family of proteins with pivotal biological functions. Here we describe the cloning and functional characterization of a novel family member, human phosphatidylethanolamine-binding protein 4 (hPEBP4). hPEBP4 is expressed in most human tissues and highly expressed in tumor cells. Its expression in tumor cells is further enhanced upon tumor necrosis factor (TNF) α treatment, whereas hPEBP4 normally co-localizes with lysosomes, TNFα stimulation triggers its transfer to the cell membrane, where it binds to Raf-1 and MEK1. L929 cells overexpressing hPEBP4 are resistant to both TNFα-induced ERK1/2, MEK1, and JNK activation and TNFα-mediated apoptosis. Co-precipitation andin vitroprotein binding assay demonstrated that hPEBP4 interacts with Raf-1 and MEK1. A truncated form of hPEBP4, lacking the PE-binding domain, maintains lysosomal co-localization but has no effect on cellular responses to TNFα. Given that MCF-7 breast cancer cells expressed hPEBP4 at a high level, small interfering RNA was used to silence the expression of hPEBP4. We demonstrated that down-regulation of hPEBP4 expression sensitizes MCF-7 breast cancer cells to TNFα-induced apoptosis. hPEBP4 appears to promote cellular resistance to TNF-induced apoptosis by inhibiting activation of the Raf-1/MEK/ERK pathway, JNK, and PE externalization, and the conserved region of PE-binding domain appears to play a vital role in this biological activity of hPEBP4.

scholarly journals Cross-Resistance of CD95- and Drug-Induced Apoptosis as a Consequence of Deficient Activation of Caspases (ICE/Ced-3 Proteases)

Blood ◽  
1997 ◽  
Vol 90 (8) ◽  
pp. 3118-3129 ◽  
Author(s):  
Marek Los ◽  
Ingrid Herr ◽  
Claudia Friesen ◽  
Simone Fulda ◽  
Klaus Schulze-Osthoff ◽  
...  
Keyword(s):  
Cell Death ◽  
Drug Treatment ◽  
Tumor Cells ◽  
Anticancer Drugs ◽  
Ex Vivo ◽  
Resistant Cell ◽  
Cross Resistance ◽  
Strong Increase ◽  
Drug Induced ◽  
Induced Apoptosis

Abstract The cytotoxic effect of anticancer drugs has been shown to involve induction of apoptosis. We report here that tumor cells resistant to CD95 (APO-1/Fas) -mediated apoptosis were cross-resistant to apoptosis-induced by anticancer drugs. Apoptosis induced in tumor cells by cytarabine, doxorubicin, and methotrexate required the activation of ICE/Ced-3 proteases (caspases), similarly to the CD95 system. After drug treatment, a strong increase of caspase activity was found that preceded cell death. Drug-induced activation of caspases was also found in ex vivo-derived T-cell leukemia cells. Resistance to cell death was conferred by a peptide caspase inhibitor and CrmA, a poxvirus-derived serpin. The peptide inhibitor was effective even if added several hours after drug treatment, indicating a direct involvement of caspases in the execution and not in the trigger phase of drug action. Drug-induced apoptosis was also strongly inhibited by antisense approaches targeting caspase-1 and -3, indicating that several members of this protease family were involved. CD95-resistant cell lines that failed to activate caspases upon CD95 triggering were cross-resistant to drug-mediated apoptosis. Our data strongly support the concept that sensitivity for drug-induced cell death depends on intact apoptosis pathways leading to activation of caspases. The identification of defects in caspase activation may provide molecular targets to overcome drug resistance in tumor cells.

scholarly journals Green light-induced apoptosis in cancer cells by a tetrapyridyl ruthenium prodrug offering two trans coordination sites

2016 ◽  
Vol 7 (8) ◽  
pp. 4922-4929 ◽  
Author(s):  
V. H. S. van Rixel ◽  
B. Siewert ◽  
S. L. Hopkins ◽  
S. H. C. Askes ◽  
A. Busemann ◽  
...  
Keyword(s):  
Cell Death ◽  
Singlet Oxygen ◽  
Cancer Cells ◽  
Green Light ◽  
Oxygen Generation ◽  
Light Cell ◽  
Singlet Oxygen Generation ◽  
Coordination Sites ◽  
Induced Apoptosis ◽  
Apoptosis In Cancer Cells

In this work, two new photopharmacological ruthenium prodrugs are described that can be activated by green light. Cell death occurs via apoptosis; it is not a consequence of singlet oxygen generation, but of light-induced photosubstitution reactions.

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