scholarly journals Impact of Autophagy Inhibition at Different Stages on Cytotoxic Effect of Autophagy Inducer in Glioblastoma Cells

2015 ◽  
Vol 35 (4) ◽  
pp. 1303-1316 ◽  
Author(s):  
Chenguang Li ◽  
Yaohua Liu ◽  
Huailei Liu ◽  
Weiguang Zhang ◽  
Chen Shen ◽  
...  
Keyword(s):  
Western Blot ◽  
Late Stage ◽  
Cytotoxic Effect ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Initial Step ◽  
Beclin 1 ◽  
Therapeutic Effects ◽  
Glioblastoma Cells ◽  
Autophagy Inhibition

Background/Aims: Glioblastoma multiforme (GBM) is the most malignant primary brain tumor with a poor prognosis. Combination treatment of autophagy inducer and autophagy inhibitor may be a feasible solution to improve the therapeutic effects. However, the correlation between them is unclear. The purpose of this study was to investigate the effect of autophagy inhibition at different stages on cytotoxicity of autophagy inducers in glioblastoma cells. Methods: Autophagy inhibition at early stage was achieved by 3-methyladenine (3-MA) or Beclin 1 shRNA. Autophagy inhibition at late stage was achieved by chloroquine (CQ) or Rab7 shRNA. Cell viability was assessed by MTT assay. Autophagy was measured using transmission electron microscopy and western blot. Apoptosis was measured using western blot and flow-cytometry. Results: Inhibition of early steps of autophagy by 3-MA or Beclin 1 knockdown decreased the toxic effect of arsenic trioxide (ATO) in GBM cell lines. In contrast, blockade of autophagy flux at late stage by CQ or Rab7 knockdown enhanced the cytotoxicity of ATO, and caused accumulation of degradative autophagic vacuoles and robust apoptosis. Moreover, depletion of Beclin 1 abolished the synergistic effect of ATO and CQ by reducing autophagy and apoptosis. Combination of CQ with other autophagy inducers also induced synergistic apoptotic cell death. Conclusion: These results suggest that inhibition of late process of autophagy, not initial step, increases the cytotoxic effect of autophagy inducers via autophagy and apoptosis, which may contribute to GBM chemotherapy.

scholarly journals Effect of early-stage autophagy inhibition in BRAFV600E autophagy-dependent brain tumor cells

2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Shadi Zahedi ◽  
Brent E. Fitzwalter ◽  
Andrew Morin ◽  
Sydney Grob ◽  
Michele Desmarais ◽  
...  
Keyword(s):  
Cell Survival ◽  
Tumor Cells ◽  
Late Stage ◽  
Early Stage ◽  
Specific Effect ◽  
Cns Tumors ◽  
Autophagic Flux ◽  
Dependent Manner ◽  
Tumor Cell Death ◽  
Autophagy Inhibition

Abstract Autophagy is a multistage process. Progress within the field has led to the development of agents targeting both early (initiation) and late (fusion) stages of this process. The specific stage of autophagy targeted may influence cancer treatment outcomes. We have previously shown that central nervous system (CNS) tumors with the BRAFV600E mutation are autophagy dependent, and late-stage autophagy inhibition improves the response to targeted BRAF inhibitors (BRAFi) in sensitive and resistant cells. Drugs directed toward initiation of autophagy have been shown to reduce tumor cell death in some cancers, but have not been assessed in CNS tumors. We investigated early-stage inhibition for autophagy-dependent CNS tumors. BRAFi-sensitive and resistant AM38 and MAF794 cell lines were evaluated for the response to pharmacologic and genetic inhibition of ULK1 and VPS34, two crucial subunits of the autophagy initiation complexes. Changes in autophagy were monitored by western blot and flow cytometry. Survival was evaluated in short- and long-term growth assays. Tumor cells exhibited a reduced autophagic flux with pharmacologic and genetic inhibition of ULK1 or VPS34. Pharmacologic inhibition reduced cell survival in a dose-dependent manner for both targets. Genetic inhibition reduced cell survival and confirmed that it was an autophagy-specific effect. Pharmacologic and genetic inhibition were also synergistic with BRAFi, irrespective of RAFi sensitivity. Inhibition of ULK1 and VPS34 are potentially viable clinical targets in autophagy-dependent CNS tumors. Further evaluation is needed to determine if early-stage autophagy inhibition is equal to late-stage inhibition to determine the optimal clinical target for patients.

scholarly journals Inhibition of autophagy triggers melatonin-induced apoptosis in glioblastoma cells

2019 ◽  
Author(s):  
Nan Zhou ◽  
Zixuan Wei ◽  
Zengxin Qi
Keyword(s):  
Direct Evidence ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Melatonin Receptor ◽  
Glioblastoma Cells ◽  
Human Glioma Cells ◽  
Melatonin Treatment ◽  
Induced Apoptosis

Abstract Background: Autophagy is considered to be another restorative focus for the treatment of brain tumors. Although several research have demonstrated that melatonin induces autophagy in colon cancer and hepatoma cells, there has not been any direct evidence of whether melatonin is capable of inducing autophagy in human glioma cells. Results: In the present research, we report that melatonin or its agonist, agomelatine, induced autophagy in A172 and U87-MG glioblastoma cells for a concentration-and time-dependent way, which was significantly attenuated by treatment with luzindole, a melatonin receptor antagonist. Furthermore, by suppressing autophagy at the late-stage with bafilomycin A1 and early stage with 3-MA, we found that the melatonin-induced autophagy was activated early, and the autophagic flux was complete. Melatonin treatment alone did not induce any apoptotic changes in the glioblastoma cells, as measured by flow cytometry. Western blot studies confirmed that melatonin alone prominently upregulated the levels of Beclin 1 and LC3 II, which was accompanied by an increase in the expression of Bcl-2, whereas it had no effect on the expression of Bax in the glioblastoma cells. Remarkably, co-treatment with 3-MA and melatonin significantly enhanced the apoptotic cell population in the glioblastoma cells, along with a prominent decrease in the expression of bcl-2 and increase in the Bax expression levels, which collectively indicated that the disruption of autophagy triggers the melatonin-induced apoptosis in glioblastoma cells. Conclusions: These results provide information indicating that melatonin may act as a common upstream signal between autophagy and apoptosis, which may lead to the development of new therapeutic strategies for glioma.

scholarly journals Inhibition of autophagy triggers melatonin-induced apoptosis in glioblastoma cells

2019 ◽  
Author(s):  
Nan Zhou ◽  
Zixuan Wei ◽  
Zengxin Qi
Keyword(s):  
Direct Evidence ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Melatonin Receptor ◽  
Glioblastoma Cells ◽  
Human Glioma Cells ◽  
Melatonin Treatment ◽  
Induced Apoptosis

Abstract Background: Autophagy is considered to beanother restorative focus for the treatment of brain tumors. Although several research have demonstrated that melatonin induces autophagy in colon cancer and hepatoma cells, there has not been any direct evidence of whether melatonin is capable of inducing autophagy in human glioma cells. Results: In the present research, we report that melatonin or its agonist, agomelatine, induced autophagy inA172 and U87-MG glioblastoma cells for a concentration-and time-dependent way, whichwas significantly attenuated by treatment with luzindole, a melatonin receptor antagonist. Furthermore, by suppressing autophagy at the late-stage with bafilomycin A1 and early stage with 3-MA, we found that the melatonin-induced autophagy was activated early, and the autophagic flux was complete. Melatonin treatment alone did not induce any apoptotic changes in the glioblastoma cells, as measured by flow cytometry. Western blot studies confirmed that melatonin alone prominently upregulated the levels of Beclin 1 and LC3 II, which was accompanied by an increase in the expression of Bcl-2, whereas it had no effect on the expression of Bax in the glioblastoma cells. Remarkably, co-treatment with 3-MA and melatonin significantly enhanced the apoptotic cell population in the glioblastoma cells, along with a prominent decrease in the expression of bcl-2 and increase in the Bax expression levels, which collectively indicated that the disruption of autophagy triggers the melatonin-induced apoptosis in glioblastoma cells. Conclusions: These results provide information indicating that melatonin may act as a common upstream signal between autophagy and apoptosis, which may lead to the development of new therapeutic strategies for glioma.

scholarly journals Inhibition of autophagy triggers melatonin-induced apoptosis in glioblastoma cells

2019 ◽  
Author(s):  
Nan Zhou ◽  
Zixuan Wei ◽  
Zengxin Qi
Keyword(s):  
Direct Evidence ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Melatonin Receptor ◽  
Glioblastoma Cells ◽  
Human Glioma Cells ◽  
Melatonin Treatment ◽  
Induced Apoptosis

Abstract Background: Autophagy is considered to beanother restorative focus for the treatment of brain tumors. Although several research have demonstrated that melatonin induces autophagy in colon cancer and hepatoma cells, there has not been any direct evidence of whether melatonin is capable of inducing autophagy in human glioma cells. Results: In the present research, we report that melatonin or its agonist, agomelatine, induced autophagy inA172 and U87-MG glioblastoma cells for a concentration-and time-dependent way, whichwas significantly attenuated by treatment with luzindole, a melatonin receptor antagonist. Furthermore, by suppressing autophagy at the late-stage with bafilomycin A1 and early stage with 3-MA, we found that the melatonin-induced autophagy was activated early, and the autophagic flux was complete. Melatonin treatment alone did not induce any apoptotic changes in the glioblastoma cells, as measured by flow cytometry. Western blot studies confirmed that melatonin alone prominently upregulated the levels of Beclin 1 and LC3 II, which was accompanied by an increase in the expression of Bcl-2, whereas it had no effect on the expression of Bax in the glioblastoma cells. Remarkably, co-treatment with 3-MA and melatonin significantly enhanced the apoptotic cell population in the glioblastoma cells, along with a prominent decrease in the expression of bcl-2 and increase in the Bax expression levels, which collectively indicated that the disruption of autophagy triggers the melatonin-induced apoptosis in glioblastoma cells. Conclusions: These results provide information indicating that melatonin may act as a common upstream signal between autophagy and apoptosis, which may lead to the development of new therapeutic strategies for glioma.

scholarly journals Inhibition of autophagy triggers melatonin-induced apoptosis in glioblastoma cells

2019 ◽  
Author(s):  
Nan Zhou ◽  
Zixuan Wei ◽  
Zengxin Qi
Keyword(s):  
Direct Evidence ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Melatonin Receptor ◽  
Glioblastoma Cells ◽  
Human Glioma Cells ◽  
Melatonin Treatment ◽  
Induced Apoptosis

Abstract Background: Autophagy is considered to be another restorative focus for the treatment of brain tumors. Although several research have demonstrated that melatonin induces autophagy in colon cancer and hepatoma cells, there has not been any direct evidence of whether melatonin is capable of inducing autophagy in human glioma cells. Results: In the present research, we report that melatonin or its agonist, agomelatine, induced autophagy in A172 and U87-MG glioblastoma cells for a concentration-and time-dependent way, which was significantly attenuated by treatment with luzindole, a melatonin receptor antagonist. Furthermore, by suppressing autophagy at the late-stage with bafilomycin A1 and early stage with 3-MA, we found that the melatonin-induced autophagy was activated early, and the autophagic flux was complete. Melatonin treatment alone did not induce any apoptotic changes in the glioblastoma cells, as measured by flow cytometry. Western blot studies confirmed that melatonin alone prominently upregulated the levels of Beclin 1 and LC3 II, which was accompanied by an increase in the expression of Bcl-2, whereas it had no effect on the expression of Bax in the glioblastoma cells. Remarkably, co-treatment with 3-MA and melatonin significantly enhanced the apoptotic cell population in the glioblastoma cells, along with a prominent decrease in the expression of bcl-2 and increase in the Bax expression levels, which collectively indicated that the disruption of autophagy triggers the melatonin-induced apoptosis in glioblastoma cells. Conclusions: These results provide information indicating that melatonin may act as a common upstream signal between autophagy and apoptosis, which may lead to the development of new therapeutic strategies for glioma.

scholarly journals Inhibition of autophagy triggers melatonin-induced apoptosis in glioblastoma cells

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Nan Zhou ◽  
Zi Xuan Wei ◽  
Zeng Xin Qi
Keyword(s):  
Direct Evidence ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Autophagic Flux ◽  
Bafilomycin A1 ◽  
Melatonin Receptor ◽  
Glioblastoma Cells ◽  
Human Glioma Cells ◽  
Melatonin Treatment ◽  
Induced Apoptosis

Abstract Background Autophagy is considered to be another restorative focus for the treatment of brain tumors. Although several research have demonstrated that melatonin induces autophagy in colon cancer and hepatoma cells, there has not been any direct evidence of whether melatonin is capable of inducing autophagy in human glioma cells. Results In the present research, we report that melatonin or its agonist, agomelatine, induced autophagy in A172 and U87-MG glioblastoma cells for a concentration-and time-dependent way, which was significantly attenuated by treatment with luzindole, a melatonin receptor antagonist. Furthermore, by suppressing autophagy at the late-stage with bafilomycin A1 and early stage with 3-MA, we found that the melatonin-induced autophagy was activated early, and the autophagic flux was complete. Melatonin treatment alone did not induce any apoptotic changes in the glioblastoma cells, as measured by flow cytometry. Western blot studies confirmed that melatonin alone prominently upregulated the levels of Beclin 1 and LC3 II, which was accompanied by an increase in the expression of Bcl-2, whereas it had no effect on the expression of Bax in the glioblastoma cells. Remarkably, co-treatment with 3-MA and melatonin significantly enhanced the apoptotic cell population in the glioblastoma cells, along with a prominent decrease in the expression of bcl-2 and increase in the Bax expression levels, which collectively indicated that the disruption of autophagy triggers the melatonin-induced apoptosis in glioblastoma cells. Conclusions These results provide information indicating that melatonin may act as a common upstream signal between autophagy and apoptosis, which may lead to the development of new therapeutic strategies for glioma.

The BH3-Mimetic Obatoclax Restores the Response to Dexamethasone in Glucocorticoid-Resistant ALL through Induction of Autophagy.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 806-806
Author(s):  
Laura Bonapace ◽  
Beat C. Bornhauser ◽  
Gunnar Cario ◽  
Martin Schrappe ◽  
Felix Niggli ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytotoxic Effect ◽  
Low Dose ◽  
Beclin 1 ◽  
Therapeutic Effects ◽  
Alternative Mechanism ◽  
Intrinsic Pathway ◽  
Autophagy Induction ◽  
Sensitizing Effect ◽  
Bh3 Mimetic

Abstract Incorporation of cell death-inducing agents into current therapeutic regimens is an attractive strategy to improve treatment for drug resistant leukemia. We tested the potential of the pan-Bcl-2 family antagonist BH3 mimetic obatoclax (GX15-070) to restore the glucocorticoid (GC) response in GC-resistant childhood acute lymphoblastic leukemia (ALL). One tenth of the IC50 dose of obatoclax was sufficient to restore GC-sensitivity in vitro of primary ALL cells from T-cell and precursor B-cell ALL patients with poor in vivo response to prednisone. In GC-resistant cell lines, this effect was associated with strong caspase activation, externalization of annexin V and resulted in caspase-dependent cell death. Overexpression of either Mcl-1 or Bcl-XL interfered with the cytotoxic effect of obatoclax as single agent, but not with the GC-sensitizing effect of low-dose obatoclax. We hypothesized that an alternative mechanism could be involved, which may be independent of the regulation of the intrinsic pathway of apoptosis by members of the Bcl-2 family. Consistent with this hypothesis, we observed that obatoclax was also cytotoxic for mouse embryonal fibroblasts with homozygous deletions of Bax and Bak (Bax/Bak DKO), in which the intrinsic pathway is blocked completely. The IC50 of obatoclax on DKO cells was 200 nM. Given that induction of autophagy can lead to an alternative mode of programmed cell death, and because autophagy induction is also controlled by anti-apoptotic Bcl2-family members via an interaction with the essential autophagy BH3-only protein Beclin-1, we asked whether autophagy involved in mediating the therapeutic effects of obatoclax in our model. Using the LC3-GFP reporter system, we detected strong induction of autophagic vacuoles after treatment of Bax/Bak DKO and ALL cells with IC50 concentrations of 200 and 800 nM obatoclax, respectively. Autophagy induction was confirmed by detection of the expected cleavage products of the endogenous autophagy protein LC-3 by Western blotting. Low dose obatoclax induced autophagy only in combination with dexamethasone. Inhibition of autophagy using 3-methyl-adenosine (3-MA) or downregulation of Beclin-1 by RNA interference abrogated the GC-sensitizing effect of obatoclax completely in ALL cells, and strongly interfered with the cytotoxic effect of obatoclax on DKO cells. The restoration of GC-resistance by Beclin-1 knock-down was associated with a marked decrease of caspase-3 activation. These data indicate that induction of autophagy by obatoclax is required to initiate a caspase-dependent death pathway. Furthermore, low-dose obatoclax did not impair the response to daunorubicine, vincristine and asparaginase in GC-resistant ALL cells, suggesting that induction of autophagy will not lead to drug resistance in this context. Ongoing experiments will validate the effect of obatoclax in a leukemia xenograft model of GC-resistant ALL. Collectively, our results support the notion that the incorporation of obatoclax into GC-based regimens is a promising strategy to improve the treatment of GC-resistant ALL and provide new angles for the investigation of mechanisms that are implicated in altered drug responses in resistant disease.

110 EXPRESSION AND CLONING OF OESTRADIOL RECEPTOR α AND PROGESTERONE RECEPTORS AND INTERFERONE STIMULATED GENE 15 IN ENDOMETRIUM AND CORPUS LUTEUM OF PREGNANT CAMEL

2011 ◽  
Vol 23 (1) ◽  
pp. 160
Author(s):  
A. S. Abdoon ◽  
O. M. Kandil ◽  
H. Kleim ◽  
D. Schams ◽  
B. Berisha ◽  
...  
Keyword(s):  
Western Blot ◽  
Corpus Luteum ◽  
Late Stage ◽  
Messenger Rna ◽  
Early Stage ◽  
Progesterone Receptors ◽  
Dromedary Camel ◽  
Dromedary Camels ◽  
Luteal Function ◽  
Breeding Animal

Despite their economic and cultural importance, dromedary camel is considered as a slow breeding animal, because of the higher incidence of early embryonic death. The present study was designed to investigate: 1) Expression and cloning of progesterone receptors (PR) and oestradiol receptor α (ERα) in CL and endometrium of pregnant camel; 2) Detection of interferon stimulated gene 15 (ISG15) in corpus luteum (CL) and endometrium of pregnant dromedary camels. For PR and ERα, RNA was extracted from CL and endometrium of dromedary camels during early (1 to 3 months), mid (4 to 9 months), and late stage (10 to 13 months) of pregnancy. Messenger RNA expression of PR and ERα was performed using RT-qPCR. Detection of ISG15 was performed using immunohistochemistry and Western blot analysis. In CL, both PR and ERα ± showed the same pattern with significantly high (P < 0.01) expression during early stage compared to mid or late stages of pregnancy. The lowest (P < 0.01) expression was detected during the late stage of pregnancy compared with the mid stage. There was no difference in mRNA expression for PR and ERα in endometrium of during the different stages of pregnancy in dromedary camels. ISG15 conjugated protein showed no expression in CL or endometrium of pregnant dromedary camels either by immunohistochemistry or Western blot. In conclusion, PR and ERα potentially play a role in regulating luteal function in CL during pregnancy in dromedary camels, further work is necessary to study the mechanism of pregnancy recognition in dromedary camels.

scholarly journals Mini-Review: The Administration of Apoptotic Cells for Treating Rheumatoid Arthritis: Current Knowledge and Clinical Perspectives

2021 ◽  
Vol 12 ◽  
Author(s):  
Eric Toussirot ◽  
Francis Bonnefoy ◽  
Charline Vauchy ◽  
Sylvain Perruche ◽  
Philippe Saas
Keyword(s):  
Rheumatoid Arthritis ◽  
Hematopoietic Cell Transplantation ◽  
Current Knowledge ◽  
Apoptotic Cell ◽  
Early Stage ◽  
Joint Inflammation ◽  
Experimental Models ◽  
Therapeutic Effects ◽  
Apoptotic Cells ◽  
Cell Based Therapy

Rheumatoid arthritis (RA) is a chronic immune-mediated disease managed by conventional synthetic drugs, such as methotrexate (MTX), and targeted drugs including biological agents. Cell-based therapeutic approaches are currently developed in RA, mainly mesenchymal stroma cell-based approaches. Early-stage apoptotic cells possess direct and indirect anti-inflammatory properties. During the elimination of dying cells (a process called efferocytosis), specific mechanisms operate to control immune responses. There are compelling evidences in experimental models of arthritis indicating that apoptotic cell administration may benefit joint inflammation, and may even have therapeutic effects on arthritis. Additionally, it has been demonstrated that apoptotic cells could be administered with standard treatments of RA, such as MTX or TNF inhibitors (TNFi), given even a synergistic response with TNFi. Interestingly, apoptotic cell infusion has been successfully experienced to prevent acute graft-vs.-host disease after hematopoietic cell transplantation in patients with hematologic malignancies, with a good safety profile. In this mini-review, the apoptotic cell-based therapy development in arthritis is discussed, as well as its transfer in the short-term to an innovative treatment for patients with RA. The use of apoptotic cell-derived factors, including secretome or phosphatidylserine-containing liposomes, in RA are also discussed.

Quercetin in attenuation of ischemic/reperfusion injury: A review

2020 ◽  
Vol 13 ◽  
Author(s):  
Milad Ashrafizadeh ◽  
Saeed Samarghandian ◽  
Kiavash Hushmandi ◽  
Amirhossein Zabolian ◽  
Md Shahinozzaman ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Membrane ◽  
Blood Supply ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Membrane Integrity ◽  
Therapeutic Effects ◽  
Molecular Pathways ◽  
Cell Membrane Integrity ◽  
Cell Membrane Disruption

Background: Ischemia/reperfusion (I/R) injury is a serious pathologic event that occurs due to restriction in blood supply to an organ, followed by hypoxia. This condition leads to enhanced levels of pro-inflammatory cytokines such as IL-6 and TNF-, and stimulation of oxidative stress via enhancing reactive oxygen species (ROS) levels. Upon reperfusion, blood supply increases, but it deteriorates condition, and leads to generation of ROS, cell membrane disruption and finally, cell death. Plant derived-natural compounds are well-known due to their excellent antioxidant and anti-inflammatory activities. Quercetin is a flavonoid exclusively found in different vegetables, herbs, and fruits. This naturally occurring compound possesses different pharmacological activities making it appropriate option in disease therapy. Quercetin can also demonstrate therapeutic effects via affecting molecular pathways such as NF-B, PI3K/Akt and so on. Methods: In the present review, we demonstrate that quercetin administration is beneficial in ameliorating I/R injury via reducing ROS levels, inhibition of inflammation, and affecting molecular pathways such as TLR4/NF-B, MAPK and so on. Results and conclusion: Quercetin can improve cell membrane integrity via decreasing lipid peroxidation. Apoptotic cell death is inhibited by quercetin via down-regulation of Bax, and caspases, and upregulation of Bcl-2. Quercetin is able to modulate autophagy (inhibition/induction) in decreasing I/R injury. Nanoparticles have been applied for delivery of quercetin, enhancing its bioavailability and efficacy in alleviation of I/R injury. Noteworthy, clinical trials have also confirmed the capability of quercetin in reducing I/R injury.

Sign in / Sign up

Export Citation Format

Share Document