scholarly journals Identification of a novel Bax–Cdk1 signalling complex that links activation of the mitotic checkpoint to apoptosis

2021 ◽  
Vol 134 (8) ◽  
Author(s):  
Omeed Darweesh ◽  
Eman Al-Shehri ◽  
Hugo Falquez ◽  
Joachim Lauterwasser ◽  
Frank Edlich ◽  
...  
Keyword(s):  
Cell Death ◽  
Spindle Assembly Checkpoint ◽  
Apoptotic Cell ◽  
Cell Cycle Control ◽  
Mitotic Checkpoint ◽  
Mitotic Arrest ◽  
Cancer Drug ◽  
Transient Activation ◽  
Apoptotic Proteins ◽  
Induced Apoptosis

ABSTRACT In eukaryotes, entry into and exit from mitosis is regulated, respectively, by the transient activation and inactivation of Cdk1. Taxol, an anti-microtubule anti-cancer drug, prevents microtubule–kinetochore attachments to induce spindle assembly checkpoint (SAC; also known as the mitotic checkpoint)-activated mitotic arrest. SAC activation causes mitotic arrest by chronically activating Cdk1. One consequence of prolonged Cdk1 activation is cell death. However, the cytoplasmic signal(s) that link SAC activation to the initiation of cell death remain unknown. We show here that activated Cdk1 forms a complex with the pro-apoptotic proteins Bax and Bak (also known as BAK1) during SAC-induced apoptosis. Bax- and Bak-mediated delivery of activated Cdk1 to the mitochondrion is essential for the phosphorylation of the anti-apoptotic proteins Bcl-2 and Bcl-xL (encoded by BCL2L1) and the induction of cell death. The interactions between a key cell cycle control protein and key pro-apoptotic proteins identify the Cdk1–Bax and Cdk1–Bak complexes as the long-sought-after cytoplasmic signal that couples SAC activation to the induction of apoptotic cell death.

Taxol-Induced Apoptosis May Occur Via a Signaling Pathway Independent of Microtubule Bundling and Cell Cycle Arrest

1998 ◽  
Vol 4 (S2) ◽  
pp. 1042-1043
Author(s):  
Weimin Fan ◽  
Merrill C. Miller III ◽  
Lirong Cheng ◽  
Mark C. Willingham
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Cell Cycle Arrest ◽  
Tumor Cells ◽  
Apoptotic Cell ◽  
Metastatic Breast ◽  
Mitotic Arrest ◽  
Cycle Arrest ◽  
Human Solid Tumors ◽  
Induced Apoptosis

Taxol, a plant-derived antimicrotubule agent, was originally isolated from the bark of the Pacific yew, Taxus brevifolia. This naturally occurring antineoplastic drug has been demonstrated to possess broad activity against a variety of human solid tumors, particularly in drug-refractory ovarian cancer and metastatic breast cancer (1). However, the exact mechanism of taxol's cytotoxicity against tumor cells is not entirely clear. Recent studies have demonstrated that taxol, besides causing microtubule bundling and mitotic arrest, is able to induce internucleosomal DNA fragmentation and typical morphological features of apoptosis in a number of solid tumor cells. These results clearly indicate that taxol, in addition to its classical activity against microtubules and cell cycle arrest, also possesses significant cell-killing activity by induction of apoptosis.Although it is well recognized that taxol can cause both mitotic arrest and apoptotic cell death, it remains unclear whether taxol-induced cell death is a secondary event resulting from mitotic arrest or represents a novel mechanism of taxol against tumor cells.

scholarly journals Depletion of Survivin suppresses docetaxel-induced apoptosis in HeLa cells by facilitating mitotic slippage

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Teng-Long Han ◽  
Hang Sha ◽  
Jun Ji ◽  
Yun-Tian Li ◽  
Deng-Shan Wu ◽  
...  
Keyword(s):  
Hela Cells ◽  
Spindle Assembly Checkpoint ◽  
Spindle Assembly ◽  
Clonogenic Survival ◽  
Mitotic Arrest ◽  
Apoptosis Pathway ◽  
Mitotic Slippage ◽  
Intrinsic Apoptosis Pathway ◽  
Apoptosis Protein ◽  
Induced Apoptosis

AbstractThe anticancer effects of taxanes are attributed to the induction of mitotic arrest through activation of the spindle assembly checkpoint. Cell death following extended mitotic arrest is mediated by the intrinsic apoptosis pathway. Accordingly, factors that influence the robustness of mitotic arrest or disrupt the apoptotic machinery confer drug resistance. Survivin is an inhibitor of apoptosis protein. Its overexpression is associated with chemoresistance, and its targeting leads to drug sensitization. However, Survivin also acts specifically in the spindle assembly checkpoint response to taxanes. Hence, the failure of Survivin-depleted cells to arrest in mitosis may lead to taxane resistance. Here we show that Survivin depletion protects HeLa cells against docetaxel-induced apoptosis by facilitating mitotic slippage. However, Survivin depletion does not promote clonogenic survival of tumor cells but increases the level of cellular senescence induced by docetaxel. Moreover, lentiviral overexpression of Survivin does not provide protection against docetaxel or cisplatin treatment, in contrast to the anti-apoptotic Bcl-xL or Bcl-2. Our findings suggest that targeting Survivin may influence the cell response to docetaxel by driving the cells through aberrant mitotic progression, rather than directly sensitizing cells to apoptosis.

Abstract WP62: Enhanced Neuroprotection of Normobaric Oxygenation with Ethanol Conferred by Apoptosis Reduction in Acute Ischemic Stroke

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Sweena Parmar ◽  
Xiaokun Geng ◽  
Changya Peng ◽  
Murali Guthikonda ◽  
Yuchuan Ding
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Neuroprotective Effect ◽  
Apoptotic Cell Death ◽  
Ethanol Administration ◽  
Sprague Dawley ◽  
Apoptotic Proteins

Objectives: Normobaric oxygenation (NBO) has been shown to provide neuroprotection in vivo and in vitro . Yet, a recent Phase 2 clinical trial investigating NBO therapy in acute ischemic stroke was terminated due to questionable therapeutic benefit. NBO therapy alone may be insufficient to produce improved outcomes. In our recent study, we demonstrated a strong neuroprotective effect of ethanol at a dose of 1.5 g/kg (equivalent to the human legal driving limit). In this study, we sought to identify whether low-dose ethanol administration enhances the neuroprotection offered by NBO and whether combined administration of NBO with ethanol is associated with reduced apoptosis. Methods: Sprague-Dawley rats were subjected to right middle cerebral artery occlusion (MCAO) for 2 h, followed by reperfusion. Ischemic animals received either an intraperitoneal injection of 1.0 g/kg ethanol, 2 h of 100% NBO, or both ethanol and NBO. The Cell Death Detection ELISA Assay (Roche) was performed to determine apoptotic cell death at 24 h after reperfusion. Levels of pro-apoptotic (Caspase-3, Bcl-2-associated X-BAX, and Apoptosis-Inducing Factor-AIF) and anti-apoptotic proteins (Bcl-2 and Bcl-xL) were determined by Western blot analysis at 3 and 24 h after reperfusion. Results: As expected, untreated ischemic rats had the highest apoptotic cell death. Combined NBO/ethanol therapy decreased cell death by 48%, as compared to 29% with ethanol and 22% with NBO. Similarly, combined NBO/ethanol therapy promoted the greatest expression of anti-apoptotic factors and the lowest expression of pro-apoptotic proteins at 3 h after reperfusion. This effect was maintained at 24 h and even more pronounced for AIF and Caspase-3. Conclusions: Given singularly, NBO and ethanol improved the degree of cell death, decreased the expression of pro-apoptotic proteins, and increased the expression of anti-apoptotic proteins. Yet, when administered together, their effects largely compounded. These results suggest a synergistic neuroprotection offered by NBO with ethanol, which may be attributed at least in part to their shared role in modulating neuronal apoptosis.

4-Acetyl-12,13-Epoxyl-9-Trichothecene-3,15-Diol from Isaria japonica Mediates Apoptosis of Rat Bladder Carcinoma NBT-II Cells by Decreasing Anti-apoptotic Bcl-2 Expression and Increasing Pro-apoptotic Bax Expression

2004 ◽  
Vol 32 (03) ◽  
pp. 377-387 ◽  
Author(s):  
Hyung-Jin Kim ◽  
Seon Il Jang ◽  
Young-Jun Kim ◽  
Hyun-Ock Pae ◽  
Hae-Young Won ◽  
...  
Keyword(s):  
Cell Death ◽  
Bladder Carcinoma ◽  
Cytotoxic Effect ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Morphological Changes ◽  
Rat Bladder ◽  
Apoptotic Protein ◽  
Induction Of Apoptosis ◽  
Induced Apoptosis

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3,15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.

scholarly journals Mitochondrial Pathway of α-Tocopheryl Succinate-Induced Apoptosis in Human Epidermoid Carcinoma A431 Cells

Acta Naturae ◽  
2012 ◽  
Vol 4 (3) ◽  
pp. 88-94 ◽  
Author(s):  
M. A. Savitskaya ◽  
M. S. Vildanova ◽  
O. P. Kisurina-Evgenieva ◽  
E. A. Smirnova ◽  
G. E. Onischenko
Keyword(s):  
Cell Death ◽  
Vitamin E ◽  
Apoptotic Cell ◽  
Mitochondrial Pathway ◽  
Epidermoid Carcinoma ◽  
A431 Cells ◽  
Human Carcinoma ◽  
Tocopheryl Succinate ◽  
Induced Apoptosis ◽  
Human Epidermoid Carcinoma

Vitamin E derivatives are known to act as agents exhibiting cytotoxity against tumor cells. The effect of vitamin E succinate on human epidermoid carcinoma cell line A431 was investigated in this study using live imaging, immunocytochemistry, and transmission electron microscopy. -Tocopheryl succinate-induced apoptotic cell death in A431 cells was shown to be both dose- and time-dependent. The hyperproduction of reactive oxygen species, changes in size, shape and ultrastructural characteristics of mitochondria followed by the release of cytochrome c from mitochondria to cytosol were observed. These results suggest that -tocopheryl succinate induces apoptosis that occurs via the mitochondrial pathway. Mitochondria are shown to be crucial targets in -tocopheryl succinate-induced caspase-dependent cell death in human carcinoma A431 cells.

Abstract TP266: Phenothiazines Enhance Mild Hypothermia-induced Neuroprotection via PI3K/Akt Regulation in Experimental Ischemia/Reperfusion Injury

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Hong An ◽  
Joshua Wright ◽  
Yunxia Duan ◽  
Di Wu ◽  
Xunming Ji ◽  
...  
Keyword(s):  
Cell Death ◽  
Ischemia Reperfusion Injury ◽  
Mild Hypothermia ◽  
Apoptotic Cell ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
Akt Signaling Pathway ◽  
Neuroprotective Effects ◽  
Apoptotic Proteins

Introduction: Hypothermia is an effective neuroprotectant against stroke, but its application is limited by delayed onset, prolonged duration, and significant complications. Mild hypothermia is more clinically practical but offers weaker neuroprotection. This study investigated whether the neuroprotective effects of mild hypothermia can be enhanced by phenothiazine neuroleptics (chlorpromazine and promethazine), which were reported to have depressive or hibernation-like roles on the CNS. We also worked to elucidate the role of the PI3K/Akt signaling pathway in this protective mechanism. Methods: A total of 131 adult male Sprague-Dawley rats were randomly divided into 6 groups: sham, stroke without treatment (2-hour right middle cerebral artery occlusion), and 4 treatment groups with 1) mild hypothermia (anal temperature 33-35 0 C), 2) phenothiazines (1mg/kg chlorpromazine & 1mg/kg promethazine, anal temperature 37.8-38.3 0 C), 3) combination of mild hypothermia and phenothiazines, and 4) both therapies with the addition of a p-Akt antagonist (LY294002 was injected into the lateral ventricle 30 minutes before ischemia). Infarct volume, neurological deficit, and apoptotic cell death were determined 24h post reperfusion. Expression of p-Akt, cleaved Caspase-3, pro-apoptotic (AIF & Bax) and anti-apoptotic proteins (Bcl-2 & Bcl-xL) was assessed by Western blot at 6h and 24h after reperfusion. Results: The combination of hypothermia and phenothiazines decreased (P<0.01) infarct volume and neurological deficit. This change was associated with a reduction (P<0.01) of apoptotic cell death. Each treatment alone did not induce significant neuroprotection. The combination therapy, but not each alone, promoted (P<0.01) the expression of p-Akt, accompanied with increased expression of anti-apoptotic proteins and decreased expression of pro-apoptotic proteins. The neuroprotective effects were blocked by p-Akt inhibition. Conclusion: Mild hypothermia-induced neuroprotection was enhanced by phenothiazines in an experimental ischemia/reperfusion injury model. This study supports the involvement of the PI3K/Akt signaling pathway. This novel therapeutic strategy could be developed as an effective treatment for acute ischemic stroke.

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 Neuroprotective Effects of Alpha-Mangostin on MPP+-Induced Apoptotic Cell Death in Neuroblastoma SH-SY5Y Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Prachya Janhom ◽  
Permphan Dharmasaroja
Keyword(s):  
Cell Death ◽  
Cell Viability ◽  
Caspase 3 ◽  
Nuclear Dna ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Concomitant Treatment ◽  
Ros Production ◽  
Cellular Models ◽  
Induced Apoptosis

In vitrostudies have shown that extracts from mangosteen (Garcinia mangostanaLinn.) act as antioxidants and cytoprotective agents against oxidative damage. The protective effect of alpha-mangostin, the major xanthone found in the pericarp of the mangosteen, in cellular models of Parkinson’s disease (PD), has not been investigated. This study aims to investigate whether alpha-mangostin could protect SH-SY5Y neuroblastoma cells from MPP+-induced apoptosis. The effects of alpha-mangostin on MPP+-induced cell death were evaluated with a cell viability assay, staining for nuclear DNA morphology, flow cytometry for apoptotic cells and reactive oxygen species (ROS) production, quantitative real-time PCR for the expression of p53, Bax, and Bcl-2, and western blot analysis for cleaved caspase-3. Concomitant treatment with alpha-mangostin attenuated the effect of MPP+on cell viability and apoptotic cell death. Alpha-mangostin reduced ROS formation induced by MPP+. Bax/Bcl-2 expression ratio and expression of p53 were significantly lower in cells cocultured with alpha-mangostin and MPP+. The cotreated cells showed a significant decrease in activated caspase-3 compared with MPP+treatment alone. Our data suggest that cytoprotection of alpha-mangostin against MPP+-induced apoptosis may be associated with the reduction of ROS production, modulating the balance of pro- and antiapoptotic genes, and suppression of caspase-3 activation.

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