scholarly journals Elaborating the Role of Natural Products-Induced Autophagy in Cancer Treatment: Achievements and Artifacts in the State of the Art

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Ning Wang ◽  
Yibin Feng
Keyword(s):  
Cell Death ◽  
Natural Products ◽  
Cancer Treatment ◽  
Tumor Cells ◽  
Cell Fate ◽  
Mammalian Cells ◽  
Apoptotic Cell ◽  
Rapid Expansion ◽  
Drug Study

Autophagy is a homeostatic process that is highly conserved across different types of mammalian cells. Autophagy is able to relieve tumor cell from nutrient and oxidative stress during the rapid expansion of cancer. Excessive and sustained autophagy may lead to cell death and tumor shrinkage. It was shown in literature that many anticancer natural compounds and extracts could initiate autophagy in tumor cells. As summarized in this review, the tumor suppressive action of natural products-induced autophagy may lead to cell senescence, provoke apoptosis-independent cell death, and complement apoptotic cell death by robust or target-specific mechanisms. In some cases, natural products-induced autophagy could protect tumor cells from apoptotic death. Technical variations in detecting autophagy affect data quality, and study focus should be made on elaborating the role of autophagy in deciding cell fate. In vivo study monitoring of autophagy in cancer treatment is expected to be the future direction. The clinical-relevant action of autophagy-inducing natural products should be highlighted in future study. As natural products are an important resource in discovery of lead compound of anticancer drug, study on the role of autophagy in tumor suppressive effect of natural products continues to be necessary and emerging.

scholarly journals OXPHOS Promotes Apoptotic Resistance and Persistence in TH17 cells

2021 ◽  
Author(s):  
Hanna S. Hong ◽  
Nneka E. Mbah ◽  
Mengrou Shan ◽  
Kristen Loesel ◽  
Lin Lin ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Cell Fate ◽  
Apoptotic Cell ◽  
Metabolic Phenotype ◽  
Tumor Studies ◽  
A Cell

AbstractApoptotic cell death is a cell-intrinsic, immune tolerance mechanism that regulates the magnitude and resolution of T cell-mediated responses. Evasion of apoptosis is critical for the generation of memory T cells, as well as autoimmune T cells, and knowledge of the mechanisms that enable resistance to apoptosis will provide insight into ways to modulate their activity during protective and pathogenic responses. IL-17-producing CD4 T cells (TH17s) are long-lived, memory cells. These features enable their role in host defense, chronic inflammatory disorders, and anti-tumor immunity. A growing number of reports now indicate that TH17s in vivo require mitochondrial oxidative phosphorylation (OXPHOS), a metabolic phenotype that is poorly induced in vitro. To elucidate the role of OXPHOS in TH17 processes, we developed a system to polarize TH17s that metabolically resembled their in vivo counterparts. We discovered that directing TH17s to use OXPHOS promotes mitochondrial fitness, glutamine anaplerosis, and an anti-apoptotic phenotype marked by high BCL-XL and low BIM. Through competitive co-transfer experiments and tumor studies, we further revealed how OXPHOS protects TH17s from cell death while enhancing their persistence in the periphery and tumor microenvironment. Together, our work demonstrates a non-classical role of metabolism in regulating TH17 cell fate and highlights the potential for therapies that target OXPHOS in TH17-driven diseases.

Role of p53 in the sensitization of tumor cells to apoptotic cell death

2002 ◽  
Vol 38 (12-13) ◽  
pp. 977-980 ◽  
Author(s):  
Jérôme Thiery ◽  
Hamid Echchakir ◽  
Guillaume Dorothée ◽  
Maya Ameyar-Zazoua ◽  
Heddi Haddada ◽  
...  
Keyword(s):  
Cell Death ◽  
Tumor Cells ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death

Anticancer Activity of Diosgenin and its Semi-synthetic Derivatives: Role in Autophagy Mediated Cell Death and Induction of Apoptosis

2021 ◽  
Vol 21 ◽  
Author(s):  
Nivedita Bhardwaj ◽  
Nancy Tripathi ◽  
Bharat Goel ◽  
Shreyans K. Jain
Keyword(s):  
Cell Death ◽  
Cancer Treatment ◽  
Anticancer Activity ◽  
Tumor Cells ◽  
Cancer Progression ◽  
Rational Approach ◽  
Potential Candidate ◽  
Potential Implication ◽  
Apoptosis Protein ◽  
Synthetic Derivatives

: During cancer progression, the unrestricted proliferation of cells is supported by the impaired cell death response provoked by certain oncogenes. Both autophagy and apoptosis are the signaling pathways of cell death, which are targeted for cancer treatment. Defects in apoptosis result in reduced cell death and ultimately tumor progression. The tumor cells lacking apoptosis phenomena are killed by ROS- mediated autophagy. The autophagic programmed cell death requires apoptosis protein for inhibiting tumor growth; thus, the interconnection between these two pathways determines the fate of a cell. The cross-regulation of autophagy and apoptosis is an important aspect to modulate autophagy, apoptosis and to sensibilise apoptosis-resistant tumor cells under metabolic stress and might be a rational approach for drug designing strategy for the treatment of cancer. Numerous proteins involved in autophagy have been investigated as the druggable target for anticancer therapy. Several compounds of natural origin have been reported, to control autophagy activity through the PI3K/Akt/mTOR key pathway. Diosgenin, a steroidal sapogenin has emerged as a potential candidate for cancer treatment. It induces ROS-mediated autophagy, inhibits PI3K/Akt/mTOR pathway, and produces cytotoxicity selectively in cancer cells. This review aims to focus on optimal strategies using diosgenin to induce apoptosis by modulating the pathways involved in autophagy regulation and its potential implication in the treatment of various cancer. The discussion has been extended to the medicinal chemistry of semi-synthetic derivatives of diosgenin exhibiting anticancer activity.

scholarly journals Role of hepcidin in oxidative stress and cell death of cultured mouse renal collecting duct cells: protection against iron and sensitization to cadmium

2021 ◽  
Author(s):  
Stephanie Probst ◽  
Johannes Fels ◽  
Bettina Scharner ◽  
Natascha A. Wolff ◽  
Eleni Roussa ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Cell Fate ◽  
Catalase Activity ◽  
Metal Ion ◽  
Iron Homeostasis ◽  
Collecting Duct ◽  
Duct Cell ◽  
Plasmid Transfection

AbstractThe liver hormone hepcidin regulates systemic iron homeostasis. Hepcidin is also expressed by the kidney, but exclusively in distal nephron segments. Several studies suggest hepcidin protects against kidney damage involving Fe2+ overload. The nephrotoxic non-essential metal ion Cd2+ can displace Fe2+ from cellular biomolecules, causing oxidative stress and cell death. The role of hepcidin in Fe2+ and Cd2+ toxicity was assessed in mouse renal cortical [mCCD(cl.1)] and inner medullary [mIMCD3] collecting duct cell lines. Cells were exposed to equipotent Cd2+ (0.5–5 μmol/l) and/or Fe2+ (50–100 μmol/l) for 4–24 h. Hepcidin (Hamp1) was transiently silenced by RNAi or overexpressed by plasmid transfection. Hepcidin or catalase expression were evaluated by RT-PCR, qPCR, immunoblotting or immunofluorescence microscopy, and cell fate by MTT, apoptosis and necrosis assays. Reactive oxygen species (ROS) were detected using CellROX™ Green and catalase activity by fluorometry. Hepcidin upregulation protected against Fe2+-induced mIMCD3 cell death by increasing catalase activity and reducing ROS, but exacerbated Cd2+-induced catalase dysfunction, increasing ROS and cell death. Opposite effects were observed with Hamp1 siRNA. Similar to Hamp1 silencing, increased intracellular Fe2+ prevented Cd2+ damage, ROS formation and catalase disruption whereas chelation of intracellular Fe2+ with desferrioxamine augmented Cd2+ damage, corresponding to hepcidin upregulation. Comparable effects were observed in mCCD(cl.1) cells, indicating equivalent functions of renal hepcidin in different collecting duct segments. In conclusion, hepcidin likely binds Fe2+, but not Cd2+. Because Fe2+ and Cd2+ compete for functional binding sites in proteins, hepcidin affects their free metal ion pools and differentially impacts downstream processes and cell fate.

Presenilin-1 regulates neuronal differentiation during neurogenesis

Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2593-2606 ◽  
Author(s):  
M. Handler ◽  
X. Yang ◽  
J. Shen
Keyword(s):  
Cell Death ◽  
Progenitor Cells ◽  
Neuronal Differentiation ◽  
Cell Fate ◽  
Neural Progenitor Cells ◽  
Apoptotic Cell ◽  
Ventricular Zone ◽  
Neural Progenitor ◽  
Apoptotic Cell Death ◽  
Presenilin 1

Mutations in Presenilin-1 (PS1) are a major cause of familial Alzheimer's disease. Our previous studies showed that PS1 is required for murine neural development. Here we report that lack of PS1 leads to premature differentiation of neural progenitor cells, indicating a role for PS1 in a cell fate decision between postmitotic neurons and neural progenitor cells. Neural proliferation and apoptotic cell death during neurogenesis are unaltered in PS1(−/−) mice, suggesting that the reduction in the neural progenitor cells observed in the PS1(−/−) brain is due to premature differentiation of progenitor cells, rather than to increased apoptotic cell death or decreased cell proliferation. In addition, the premature neuronal differentiation in the PS1(−/−) brain is associated with aberrant neuronal migration and disorganization of the laminar architecture of the developing cerebral hemisphere. In the ventricular zone of PS1(−/−) mice, expression of the Notch1 downstream effector gene Hes5 is reduced and expression of the Notch1 ligand Dll1 is elevated, whereas expression of Notch1 is unchanged. The level of Dll1 transcripts is also increased in the presomitic mesoderm of PS1(−/−) embryos, while the level of Notch1 transcripts is unchanged, in contrast to a previous report (Wong et al., 1997, Nature 387, 288–292). These results provide direct evidence that PS1 controls neuronal differentiation in association with the downregulation of Notch signalling during neurogenesis.

scholarly journals Epigenetic Targeting of Autophagy via HDAC Inhibition in Tumor Cells: Role of p53

2018 ◽  
Vol 19 (12) ◽  
pp. 3952 ◽  
Author(s):  
Maria Mrakovcic ◽  
Lauren Bohner ◽  
Marcel Hanisch ◽  
Leopold F. Fröhlich
Keyword(s):  
Cell Death ◽  
Tumor Cells ◽  
Histone Deacetylase ◽  
Stress Responses ◽  
Histone Deacetylase Inhibitors ◽  
Tumor Therapy ◽  
Regulatory System ◽  
Anticancer Activities ◽  
Mutational Status

Tumor development and progression is the consequence of genetic as well as epigenetic alterations of the cell. As part of the epigenetic regulatory system, histone acetyltransferases (HATs) and deacetylases (HDACs) drive the modification of histone as well as non-histone proteins. Derailed acetylation-mediated gene expression in cancer due to a delicate imbalance in HDAC expression can be reversed by histone deacetylase inhibitors (HDACi). Histone deacetylase inhibitors have far-reaching anticancer activities that include the induction of cell cycle arrest, the inhibition of angiogenesis, immunomodulatory responses, the inhibition of stress responses, increased generation of oxidative stress, activation of apoptosis, autophagy eliciting cell death, and even the regulation of non-coding RNA expression in malignant tumor cells. However, it remains an ongoing issue how tumor cells determine to respond to HDACi treatment by preferentially undergoing apoptosis or autophagy. In this review, we summarize HDACi-mediated mechanisms of action, particularly with respect to the induction of cell death. There is a keen interest in assessing suitable molecular factors allowing a prognosis of HDACi-mediated treatment. Addressing the results of our recent study, we highlight the role of p53 as a molecular switch driving HDACi-mediated cellular responses towards one of both types of cell death. These findings underline the importance to determine the mutational status of p53 for an effective outcome in HDACi-mediated tumor therapy.

scholarly journals ADP-Ribosylation of Actin by the Clostridium botulinum C2 Toxin in Mammalian Cells Results in Delayed Caspase-Dependent Apoptotic Cell Death

2008 ◽  
Vol 76 (10) ◽  
pp. 4600-4608 ◽  
Author(s):  
Karin Heine ◽  
Sascha Pust ◽  
Stefanie Enzenmüller ◽  
Holger Barth
Keyword(s):  
Cell Death ◽  
Cell Lines ◽  
Mammalian Cells ◽  
Clostridium Botulinum ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Adp Ribosylation ◽  
Mammalian Cell Lines ◽  
Adp Ribosyltransferase ◽  
C2 Toxin

ABSTRACT The binary C2 toxin from Clostridium botulinum mono-ADP-ribosylates G-actin in the cytosol of eukaryotic cells. This modification leads to depolymerization of actin filaments accompanied by cell rounding within 3 h of incubation but does not immediately induce cell death. Here we investigated the long-term responses of mammalian cell lines (HeLa and Vero) following C2 toxin treatment. Cells stayed round even though the toxin was removed from the medium after its internalization into the cells. No unmodified actin reappeared in the C2 toxin-treated cells within 48 h. Despite actin being completely ADP-ribosylated after about 7 h, no obvious decrease in the overall amount of actin was observed for at least 48 h. Therefore, ADP-ribosylation was not a signal for an accelerated degradation of actin in the tested cell lines. C2 toxin treatment resulted in delayed apoptotic cell death that became detectable about 15 to 24 h after toxin application in a portion of the cells. Poly(ADP)-ribosyltransferase 1 (PARP-1) was cleaved in C2 toxin-treated cells, an indication of caspase 3 activation and a hallmark of apoptosis. Furthermore, specific caspase inhibitors prevented C2 toxin-induced apoptosis, implying that caspases 8 and 9 were activated in C2 toxin-treated cells. C2I, the ADP-ribosyltransferase component of the C2 toxin, remained active in the cytosol for at least 48 h, and no extensive degradation of C2I was observed. From our data, we conclude that the long-lived nature of C2I in the host cell cytosol was essential for the nonreversible cytotoxic effect of C2 toxin, resulting in delayed apoptosis of the tested mammalian cells.

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