Geraniin induces apoptotic cell death in human lung adenocarcinoma A549 cells in vitro and in vivo

2013 ◽  
Vol 91 (12) ◽  
pp. 1016-1024 ◽  
Author(s):  
Jia Li ◽  
Siran Wang ◽  
Jimei Yin ◽  
Linna Pan
Keyword(s):  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Apoptotic Cell ◽  
A549 Cells ◽  
Tumor Growth Inhibition ◽  
Dependent Manner ◽  
Cytochrome C Release ◽  
Lung Adenocarcinoma A549

Geraniin has previously been reported to possess extensive biological activity. In this study, we reported that geraniin is an inhibitor of tumor activity in vitro and in vivo. Geraniin suppressed the proliferation of A549 cells in a dose- and time-dependent manner. Geraniin arrested the cell cycle in the S phase and induced a significant accumulation of reactive oxygen species (ROS), as well as an increased percentage of cells with mitochondrial membrane potential (MMP) disruption. Western blot analysis showed that geraniin inhibited Bcl-2 expression and induced Bax expression to disintegrate the outer mitochondrial membrane and cause cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascades. Additionally, geraniin resulted in tumor growth inhibition in A549 xenografts. Our results indicate cytotoxic activity of geraniin towards cancer cells in vitro and in vivo.

Palladacycles catalyse the oxidation of critical thiols of the mitochondrial membrane proteins and lead to mitochondrial permeabilization and cytochrome c release associated with apoptosis

2008 ◽  
Vol 417 (1) ◽  
pp. 247-256 ◽  
Author(s):  
Débora P. Santana ◽  
Priscila A. Faria ◽  
Edgar J. Paredes-Gamero ◽  
Antonio C. F. Caires ◽  
Iseli L. Nantes ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Cytochrome C ◽  
Disulfide Bonds ◽  
Mitochondrial Membrane ◽  
Apoptotic Cell ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Cytochrome C Release ◽  
Mitochondrial Permeabilization

Permeabilization of the mitochondrial membrane has been extensively associated with necrotic and apoptotic cell death. Similarly to what had been previously observed for B16F10-Nex2 murine melanoma cells, PdC (palladacycle compounds) obtained from the reaction of dmpa (N,N-dimethyl-1-phenethylamine) with the dppe [1,2-ethanebis(diphenylphosphine)] were able to induce apoptosis in HTC (hepatoma, tissue culture) cells, presenting anticancer activity in vitro. To elucidate cell site-specific actions of dmpa:dppe that could respond to the induction of apoptosis in cancer cells in the present study, we investigated the effects of PdC on isolated RLM (rat liver mitochondria). Our results showed that these palladacycles are able to induce a Ca2+-independent mitochondrial swelling that was not inhibited by ADP, Mg2+ and antioxidants. However, the PdC-induced mitochondrial permeabilization was partially prevented by pre-incubation with CsA (cyclosporin A), NEM (N-ethylmaleimide) and bongkreic acid and totally prevented by DTT (dithiothreitol). A decrease in the content of reduced thiol groups of the mitochondrial membrane proteins was also observed, as well as the presence of membrane protein aggregates in SDS/PAGE without lipid and GSH oxidation. FTIR (Fourier-transform IR) analysis of PdC-treated RLM demonstrated the formation of disulfide bonds between critical thiols in mitochondrial membrane proteins. Associated with the mitochondrial permeabilization, PdC also induced the release of cytochrome c, which is sensitive to inhibition by DTT. Besides the contribution to clarify the pro-apoptotic mechanism of PdC, this study shows that the catalysis of specific protein thiol cross-linkage is enough to induce mitochondrial permeabilization and cytochrome c release.

scholarly journals Regulated Targeting of BAX to Mitochondria

1998 ◽  
Vol 143 (1) ◽  
pp. 207-215 ◽  
Author(s):  
Ing Swie Goping ◽  
Atan Gross ◽  
Josée N. Lavoie ◽  
Mai Nguyen ◽  
Ronald Jemmerson ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Transmembrane Domain ◽  
Apoptotic Cell ◽  
Membrane Insertion ◽  
Cell Extracts ◽  
Proapoptotic Protein ◽  
Signal Anchor ◽  
Discrete Domains

The proapoptotic protein BAX contains a single predicted transmembrane domain at its COOH terminus. In unstimulated cells, BAX is located in the cytosol and in peripheral association with intracellular membranes including mitochondria, but inserts into mitochondrial membranes after a death signal. This failure to insert into mitochondrial membrane in the absence of a death signal correlates with repression of the transmembrane signal-anchor function of BAX by the NH2-terminal domain. Targeting can be instated by deleting the domain or by replacing the BAX transmembrane segment with that of BCL-2. In stimulated cells, the contribution of the NH2 terminus of BAX correlates with further exposure of this domain after membrane insertion of the protein. The peptidyl caspase inhibitor zVAD-fmk partly blocks the stimulated mitochondrial membrane insertion of BAX in vivo, which is consistent with the ability of apoptotic cell extracts to support mitochondrial targeting of BAX in vitro, dependent on activation of caspase(s). Taken together, our results suggest that regulated targeting of BAX to mitochondria in response to a death signal is mediated by discrete domains within the BAX polypeptide. The contribution of one or more caspases may reflect an initiation and/or amplification of this regulated targeting.

scholarly journals Evaluation of anticancer activity in vitro of a stable copper(I) complex with phosphine-peptide conjugate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Urszula K. Komarnicka ◽  
Barbara Pucelik ◽  
Daria Wojtala ◽  
Monika K. Lesiów ◽  
Grażyna Stochel ◽  
...  
Keyword(s):  
A549 Cells ◽  
Ros Generation ◽  
Dependent Manner ◽  
Hacat Cells ◽  
Icp Ms ◽  
Intracellular Ros ◽  
M Phase ◽  
Lung Adenocarcinoma A549 ◽  
Induced Apoptosis

Abstract[CuI(2,9-dimethyl-1,10-phenanthroline)P(p-OCH3-Ph)2CH2SarcosineGlycine] (1-MPSG), highly stable in physiological media phosphino copper(I) complex—is proposed herein as a viable alternative to anticancer platinum-based drugs. It is noteworthy that, 1-MPSG significantly and selectively reduced cell viability in a 3D spheroidal model of human lung adenocarcinoma (A549), in comparison with non-cancerous HaCaT cells. Confocal microscopy and an ICP-MS analysis showed that 1-MPSG effectively accumulates inside A549 cells with colocalization in mitochondria and nuclei. A precise cytometric analysis revealed a predominance of apoptosis over the other types of cell death. In the case of HaCaT cells, the overall cytotoxicity was significantly lower, indicating the selective activity of 1-MPSG towards cancer cells. Apoptosis also manifested itself in a decrease in mitochondrial membrane potential along with the activation of caspases-3/9. Moreover, the caspase inhibitor (Z-VAD-FMK) pretreatment led to decreased level of apoptosis (more pronouncedly in A549 cells than in non-cancerous HaCaT cells) and further validated the caspases dependence in 1-MPSG-induced apoptosis. Furthermore, the 1-MPSG complex presumably induces the changes in the cell cycle leading to G2/M phase arrest in a dose-dependent manner. It was also observed that the 1-MPSG mediated intracellular ROS alterations in A549 and HaCaT cells. These results, proved by fluorescence spectroscopy, and flow cytometry, suggest that investigated Cu(I) compound may trigger apoptosis also through ROS generation.

Spontaneous in Vitro Death of CLL Cells Can Be Prevented by Mitochondrial Stabilization Via CD160 Signaling.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4372-4372
Author(s):  
Feng-Ting Liu ◽  
Li Jia ◽  
Timothy Farren ◽  
Jerome Giustiniani ◽  
Armand Bensussan ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Conflicts Of Interest ◽  
Membrane Integrity ◽  
Lymphocytic Leukemia ◽  
Cellular Growth ◽  
Spontaneous Apoptosis ◽  
Cytochrome C Release ◽  
Phosphorylated Akt

Abstract Abstract 4372 B-cell chronic lymphocytic leukemia (CLL) is an incurable disease, which is at least partly attributable to the majority of cells being in the G0/G1 phase of the cell cycle and expressing high levels of anti-apoptotic Bcl-2 family proteins. Despite their prolonged survival in vivo, CLL cells rapidly undergo spontaneous apoptosis in vitro, suggesting that survival signals in vivo have been lost in in vitro culture conditions. CD160, a glycosylphosphatidylinositol-linked surface antigen, was found to be expressed by CLL cells. In normal NK and T-cells, CD160 mediates cellular growth and activation, but its role in CLL is unclear. Using monoclonal antibodies to CD160 (CL1-R2 or BY55 - non cross blocking) led to increased expression of Bcl-2, Bcl-xL and Mcl-1 anti-apoptotic proteins and protected CLL from spontaneous apoptosis in vitro - mean cell viability increased from 66.8 to 79.4% (n = 17, p = 0.02). These CD160-mediated events were also accompanied by decreased cytochrome C release and prevention of mitochondrial membrane potential collapse, indicating stabilization of both inner and outer mitochondrial membrane integrity. PI3K/AKT signalling is a well known survival pathway in cancer cells and in normal lymphocytes CD160 has been shown to act via PI3K/AKT. Activation of CD160 in CLL led to phosphorylated AKT, while inhibition of PI3K by wortmannin completely blocked AKT phosphorylation and CD160-mediated protection from apoptosis. In summary, the activation of CD160 protected CLL cells from spontaneous cell death in vitro via a PI3-kinase/AKT pathway. This improved survival was also associated with increased Bcl-2, Bcl-xL and Mcl-1 expression and preservation of mitochondrial function. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Bax oligomerization is required for channel-forming activity in liposomes and to trigger cytochrome c release from mitochondria

2000 ◽  
Vol 345 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Bruno ANTONSSON ◽  
Sylvie MONTESSUIT ◽  
Sandra LAUPER ◽  
Robert ESKES ◽  
Jean-Claude MARTINOU
Keyword(s):  
Cytochrome C ◽  
Molecular Mass ◽  
Lipid Membranes ◽  
Gel Filtration ◽  
Apparent Molecular Mass ◽  
Cytochrome C Release ◽  
Octyl Glucoside ◽  
Apoptotic Activity

Bax is a Bcl-2-family protein with pro-apoptotic activity that can form channels in lipid membranes. The protein has been shown to trigger cytochrome c release from mitochondria both in vitro and in vivo. Recombinant human Bax isolated in the presence of detergent was found to be present as an oligomer with an apparent molecular mass of approx. 160000 Da on gel filtration. When Bax was isolated in the absence of detergent the purified protein was monomeric with an apparent molecular mass of 22000 Da. Bax oligomers formed channels in liposomes and triggered cytochrome c release from isolated mitochondria, whereas monomeric Bax was inactive in both respects. Incubation of the monomeric Bax with 2% octyl glucoside induced formation of oligomers that displayed channel-forming activity in liposomes and triggered cytochrome c release from mitochondria. Triton X-100, Nonidet P-40 and n-dedecyl maltoside also activated monomeric Bax, whereas CHAPS had no activating effect. In cytosolic extracts from mouse liver, Bax migrated at a molecular mass of 24000 Da on gel filtration, whereas after incubation of the cytosol with 2% octyl glucoside Bax migrated at approximately 140000 Da. These results show that oligomeric Bax possesses channel-forming activity whereas monomeric Bax has no such activity.

scholarly journals Pro-apoptotic caspase deficiency reveals a cell-extrinsic mechanism of NK cell regulation

2021 ◽  
Author(s):  
Tayla M. Olsen ◽  
Wei Hong Tan ◽  
Arne C. Knudsen ◽  
Anthony Rongvaux
Keyword(s):  
Cell Death ◽  
Nk Cells ◽  
Nk Cell ◽  
Apoptotic Cell ◽  
Type I ◽  
Dependent Manner ◽  
Apoptosis Pathway ◽  
A Cell

AbstractRegulated cell death is essential for the maintenance of cellular and tissue homeostasis. In the hematopoietic system, genetic defects in apoptotic cell death generally produce the accumulation of immune cells, inflammation and autoimmunity. In contrast, we found that genetic deletion of caspases of the mitochondrial apoptosis pathway reduces natural killer (NK) cell numbers and makes NK cells functionally defective in vivo and in vitro. Caspase deficiency results in constitutive activation of a type I interferon (IFN) response, due to leakage of mitochondrial DNA and activation of the cGAS/STING pathway. The NK cell defect in caspase-deficient mice is independent of the type I IFN response, but the phenotype is partially rescued by cGAS or STING deficiency. Finally, caspase deficiency alters NK cells in a cell-extrinsic manner. Type I IFNs and NK cells are two essential effectors of antiviral immunity, and our results demonstrate that they are both regulated in a caspase-dependent manner. Beyond caspase-deficient animals, our observations may have implications in infections that trigger mitochondrial stress and caspase-dependent cell death.

scholarly journals Essential role of p21/waf1 in the mediation of the anti-proliferative effects of GHRH antagonist JMR-132

2008 ◽  
Vol 41 (5) ◽  
pp. 389-392 ◽  
Author(s):  
Aspasia-Athina Volakaki ◽  
Daniel Lafkas ◽  
Eva Kassi ◽  
Andrew V Schally ◽  
Athanasios G Papavassiliou ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Molecular Mechanism ◽  
A549 Cells ◽  
Significant Inhibition ◽  
Human Lung Cancer ◽  
Dependent Manner ◽  
Ghrh Antagonists ◽  
P21 Waf1

GHRH, besides its neuroendocrine action in controlling the release of GH from the pituitary, stimulates the growth of various cancers in vivo and in vitro by direct mechanism(s). However, the molecular mechanism that mediates these proliferative effects of GHRH in extrapituitary tissues remains poorly characterized. In the present study, we investigated whether the tumor suppressor p21/waf1 is involved in the mediation of the proliferative effects of GHRH in A549 human lung cancer epithelial cells. Exposure of A549 cells to the GHRH antagonist JMR-132 caused a significant inhibition in the rate of cell proliferation. In A549 cells, GHRH suppressed while JMR-132 increased the levels of p21 expression in a dose-dependent manner. This suggests that GHRH could regulate p21 levels. We then evaluated whether p21 is required in A549 cells for the regulation of cell proliferation by GHRH. To this end, we knocked-down p21 expression in A549 cells by siRNA and assessed the effects of antagonist JMR-132 on cell proliferation. We found that the loss of p21 expression abolished the anti-proliferative effects of JMR-132. Suppression of p21 expression by siRNA in human HT29 colon cancer cells and non-transformed mouse osteoblasts KS483 also blocked the anti-proliferative effects of JMR-132 suggesting that the regulation of cell proliferation by GHRH is p21 dependent. These results shed light on the molecular mechanism of action of GHRH antagonists in tumor tissues and suggest that the antineoplastic activity of GHRH antagonists could be considered for the treatment of cancers expressing p21.

scholarly journals Cleavage of Mcd1 by Caspase-like Protease Esp1 Promotes Apoptosis in Budding Yeast

2008 ◽  
Vol 19 (5) ◽  
pp. 2127-2134 ◽  
Author(s):  
Hui Yang ◽  
Qun Ren ◽  
Zhaojie Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Death ◽  
Membrane Potential ◽  
Cytochrome C ◽  
Mitochondrial Membrane ◽  
Apoptotic Cell ◽  
Model System ◽  
Dependent Manner ◽  
Induced Apoptosis ◽  
Dual Functions

Over the last decade, yeast has been used successfully as a model system for studying the molecular mechanism of apoptotic cell death. Here, we report that Mcd1, the yeast homology of human cohesin Rad21, plays an important role in hydrogen peroxide-induced apoptosis in yeast. On induction of cell death, Mcd1 is cleaved and the C-terminal fragment is translocated from nucleus into mitochondria, causing the decrease of mitochondrial membrane potential and the amplification of cell death in a cytochrome c-dependent manner. We further demonstrate that the caspase-like protease Esp1 has dual functions and that it is responsible for the cleavage of Mcd1 during the hydrogen peroxide-induced apoptosis. When apoptosis is induced, Esp1 is released from the anaphase inhibitor Pds1. The activated Esp1 acts as caspase-like protease for the cleavage of Mcd1, which enhances the cell death via its translocation from nucleus to mitochondria.

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