scholarly journals Okadaic acid–induced apoptosis in malignant glioma cells

2003 ◽  
Vol 14 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Bimal G. Rami ◽  
Lawrence S. Chin ◽  
Barbara E. Lazio ◽  
Satyendra K. Singh

Object Okadaic acid (OA), a potent protein phosphatase inhibitor, has been known to induce apoptosis in a variety of cell types. The authors attempted to characterize further this model by identifying proteins involved in this form of programmed cell death. Methods Cellular proliferation was assessed using a colorimetric nonradioactive proliferation assay and cell counts. Apoptosis was determined by fluorescent microscopy. Activation of the mitogen-activated protein kinase (MAPK) pathways was determined by immunoprecipitation of extracellular signal–regulated kinase (ERK), c-Jun-n-terminal kinase (JNK), and p38 followed by in vitro kinase assays. Western blot analyses were conducted to show inhibitory-κB (IκB) phosphorylation and degradation as well as Bax upregulation. The binding of nuclear factor–κB (NFκB) was shown by electrophoretic mobility shift assay. Okadaic acid induced cell death in T98G human malignant cell lines (50% inhibiting concentration = 20–25 nM). In T98G cells YO-PRO fluorescent staining was identified, thus indicating an apoptotic mechanism with a smaller percentage of cells undergoing necrotic cell death. Additionally OA induced JNK and MAPK activities in a time-dependent manner, increased the expression of Bax, and increased IκB phosphorylation and NFκB activation. There was a temporal correlation between these subcellular events and the detection of apoptosis morphology in glioma cells. Conclusions The authors believe that OA acts by blocking dephosphorylation events, thus activating apoptotic pathways through ERK and JNK activity. Additionally Bax, IκB and NFκB may also play a role in regulating these pathways.

2021 ◽  
Vol 12 ◽  
Author(s):  
Chase Gross ◽  
Dominique A. Ramirez ◽  
Stephanie McGrath ◽  
Daniel L. Gustafson

Cannabidiol (CBD), the major non-psychoactive compound found in cannabis, is frequently used both as a nutraceutical and therapeutic. Despite anecdotal evidence as an anticancer agent, little is known about the effect CBD has on cancer cells. Given the intractability and poor prognoses of brain cancers in human and veterinary medicine, we sought to characterize the in vitro cytotoxicity of CBD on human and canine gliomas. Glioma cells treated with CBD showed a range of cytotoxicity from 4.9 to 8.2 μg/ml; canine cells appeared to be more sensitive than human. Treatment with >5 μg/ml CBD invariably produced large cytosolic vesicles. The mode of cell death was then interrogated using pharmacologic inhibitors. Inhibition of apoptosis was sufficient to rescue CBD-mediated cytotoxicity. Inhibition of RIPK3, a classical necroptosis kinase, also rescued cells from death and prevented the formation of the large cytosolic vesicles. Next, cellular mitochondrial activity in the presence of CBD was assessed and within 2 hours of treatment CBD reduced oxygen consumption in a dose dependent manner with almost complete ablation of activity at 10 μg/ml CBD. Fluorescent imaging with a mitochondrial-specific dye revealed that the large cytosolic vesicles were, in fact, swollen mitochondria. Lastly, calcium channels were pharmacologically inhibited and the effect on cell death was determined. Inhibition of mitochondrial channel VDAC1, but not the TRPV1 channel, rescued cells from CBD-mediated cytotoxicity. These results demonstrate the cytotoxic nature of CBD in human and canine glioma cells and suggest a mechanism of action involving dysregulation of calcium homeostasis and mitochondrial activity.


2021 ◽  
Vol 22 (13) ◽  
pp. 6785
Author(s):  
Valeria Sogos ◽  
Paola Caria ◽  
Clara Porcedda ◽  
Rafaela Mostallino ◽  
Franca Piras ◽  
...  

Novel psychoactive substances (NPS) are synthetic substances belonging to diverse groups, designed to mimic the effects of scheduled drugs, resulting in altered toxicity and potency. Up to now, information available on the pharmacology and toxicology of these new substances is very limited, posing a considerable challenge for prevention and treatment. The present in vitro study investigated the possible mechanisms of toxicity of two emerging NPS (i) 4′-methyl-alpha-pyrrolidinoexanophenone (3,4-MDPHP), a synthetic cathinone, and (ii) 2-chloro-4,5-methylenedioxymethamphetamine (2-Cl-4,5-MDMA), a phenethylamine. In addition, to apply our model to the class of synthetic opioids, we evaluated the toxicity of fentanyl, as a reference compound for this group of frequently abused substances. To this aim, the in vitro toxic effects of these three compounds were evaluated in dopaminergic-differentiated SH-SY5Y cells. Following 24 h of exposure, all compounds induced a loss of viability, and oxidative stress in a concentration-dependent manner. 2-Cl-4,5-MDMA activates apoptotic processes, while 3,4-MDPHP elicits cell death by necrosis. Fentanyl triggers cell death through both mechanisms. Increased expression levels of pro-apoptotic Bax and caspase 3 activity were observed following 2-Cl-4,5-MDMA and fentanyl, but not 3,4-MDPHP exposure, confirming the different modes of cell death.


2020 ◽  
Vol 22 (1) ◽  
pp. 202
Author(s):  
Josephin Glück ◽  
Julia Waizenegger ◽  
Albert Braeuning ◽  
Stefanie Hessel-Pras

Pyrrolizidine alkaloids (PAs) are a group of secondary metabolites produced in various plant species as a defense mechanism against herbivores. PAs consist of a necine base, which is esterified with one or two necine acids. Humans are exposed to PAs by consumption of contaminated food. PA intoxication in humans causes acute and chronic hepatotoxicity. It is considered that enzymatic PA toxification in hepatocytes is structure-dependent. In this study, we aimed to elucidate the induction of PA-induced cell death associated with apoptosis activation. Therefore, 22 structurally different PAs were analyzed concerning the disturbance of cell viability in the metabolically competent human hepatoma cell line HepaRG. The chosen PAs represent the main necine base structures and the different esterification types. Open-chained and cyclic heliotridine- and retronecine-type diesters induced strong cytotoxic effects, while treatment of HepaRG with monoesters did not affect cell viability. For more detailed investigation of apoptosis induction, comprising caspase activation and gene expression analysis, 14 PA representatives were selected. The proapoptotic effects were in line with the potency observed in cell viability studies. In vitro data point towards a strong structure–activity relationship whose effectiveness needs to be investigated in vivo and can then be the basis for a structure-associated risk assessment.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Pengfei Liu ◽  
Jing Yuan ◽  
Yetong Feng ◽  
Xin Chen ◽  
Guangsuo Wang ◽  
...  

AbstractFerroptosis is a novel type of programmed cell death, which is different from apoptosis and autophagic cell death. Recently, ferroptosis has been indicated to contribute to the in vitro neurotoxicity induced by isoflurane, which is one of the most common anesthetics in clinic. However, the in vivo position of ferroptosis in isoflurane-induced neurotoxicity as well as learning and memory impairment remains unclear. In this study, we mainly explored the relationship between ferroptosis and isoflurane-induced learning and memory, as well as the therapeutic methods in mouse model. Our results indicated that isoflurane induced the ferroptosis in a dose-dependent and time-dependent manner in hippocampus, the organ related with learning and memory ability. In addition, the activity of cytochrome c oxidase/Complex IV in mitochondrial electron transport chain (ETC) was increased by isoflurane, which might further contributed to cysteine deprivation-induced ferroptosis caused by isoflurane exposure. More importantly, isoflurane-induced ferroptosis could be rescued by both ferroptosis inhibitor (ferrostatin-1) and mitochondria activator (dimethyl fumarate), which also showed effective therapeutic action against isoflurane-induced learning and memory impairment. Taken together, our data indicate the close association among ferroptosis, mitochondria and isoflurane, and provide a novel insight into the therapy mode against isoflurane-induced learning and memory impairment.


2005 ◽  
Vol 388 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Mário GRÃOS ◽  
Alexandra D. ALMEIDA ◽  
Sukalyan CHATTERJEE

The regulation of survival and cell death is a key determinant of cell fate. Recent evidence shows that survival and death machineries are regulated along the cell cycle. In the present paper, we show that BimEL [a BH3 (Bcl-2 homology 3)-only member of the Bcl-2 family of proteins; Bim is Bcl-2-interacting mediator of cell death; EL is the extra-long form] is phosphorylated in mitosis. This post-translational modification is dependent on MEK (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase) and growth factor signalling. Interestingly, FGF (fibroblast growth factor) signalling seems to play an essential role in this process, since, in the presence of serum, inhibition of FGF receptors abrogated phosphorylation of Bim in mitosis. Moreover, we have shown bFGF (basic FGF) to be sufficient to induce phosphorylation of Bim in serum-free conditions in any phase of the cell cycle, and also to significantly rescue cells from serum-deprivation-induced apoptosis. Our results show that, in mitosis, Bim is phosphorylated downstream of growth factor signalling in a MEK-dependent manner, with FGF signalling playing an important role. We suggest that phosphorylation of Bim is a decisive step for the survival of proliferating cells.


2021 ◽  
Vol 16 (10) ◽  
pp. 43-49
Author(s):  
Precilla S. Daisy ◽  
S. Kuduvalli Shreyas ◽  
R. Sathish ◽  
T.S. Anitha

Glioma is one of the most devastating and difficult-totreat brain tumors with a very poor prognosis. Despite the current treatment modalities, the overall survival rate is only 5% contributing to a high mortality rate. Nevertheless, of emerging treatment strategies, there is still a rising need for novel mitigation strategies to counteract glioma aggressiveness. One attempt towards this long-term goal was made in this study to reveal the combined efficacy of naringenin, a bioactive flavonoid on enhancing the anti-glioma potency of temozolomide in C6 glioma cells. The cytotoxic effect of temozolomide and naringenin, both individually and in combination was assessed by employing MTT assay. The synergistic effect of the drugs temozolomide and naringenin was determined by calculating the combination index. To confirm the presence of apoptotic changes in the cells at morphological level, acridine orange/ethidium bromide staining was performed. Further, the modulatory effects of the drugs on apoptotic genes, caspase-3 and BCL-2 were evaluated using quantitative real time-PCR. Interestingly, we found that the combinatorial drug treatment was in consensus and effectively inhibited the growth of C6 glioma cells in a dose-dependent manner. Furthermore, this combinatorial drug treatment significantly up-regulated the expression of the proapoptotic gene, caspase-3 and down-regulated the anti-apoptotic gene BCL-2 suggesting a shift of equilibrium towards apoptosis. Our findings suggest that naringenin can be employed as a potent drug to enhance the anti-glioma efficacy of temozolomide and could be therapeutically exploited for the management of glioma.


2017 ◽  
Vol 43 (5) ◽  
pp. 2074-2087 ◽  
Author(s):  
Liling Yang ◽  
Xiangjun Zhou ◽  
Weijuan Huang ◽  
Qin Fang ◽  
Jianlan Hu ◽  
...  

Background/Aims: Forsythia suspensa Vahl. (Oleaceae) fruits are widely used in traditional Chinese medicine to treat pneumonia, typhoid, dysentery, ulcers and oedema. Antibacterial and anti-inflammatory activities have been reported for phillyrin (PHN), the main ingredient in Forsythia suspensa Vahl fruits, in vitro. However, the underlying mechanisms in vivo remain poorly defined. In this study, we discovered that PHN exerted potent anti-inflammatory effects in lethal LPS-induced neutrophil inflammation by suppressing the MyD88-dependent signalling pathway in zebrafish. Methods: LPS-yolk microinjection was used to induce a lethal LPS-infected zebrafish model. The effect of PHN on the survival of zebrafish challenged with lethal LPS was evaluated using survival analysis. The effect of PHN on neutrophil inflammation grading in vivo was assessed by tracking neutrophils with a transgenic line. The effects of PHN on neutrophil production and migration were analysed by SB+ cell counts during consecutive hours after modelling. Additionally, key cytokines and members of the MyD88 signalling pathway that are involved in inflammatory response were detected using quantitative RT-PCR. To assess gene expression changes during consecutive hours after modelling, the IL-1β, IL-6, TNF-α, MyD88, TRIF, ERK1/2, JNK, IκBa and NF-κB expression levels were measured. Results: PHN could protect zebrafish against a lethal LPS challenge in a dose-dependent manner, as indicated by decreased neutrophil infltration, reduced tissue necrosis and increased survival rates. Up-regulated IL-1β, IL-6 and TNF-α expression also showed the same tendencies of depression by PHN. Critically, PHN significantly inhibited the LPS-induced activation of MyD88, IκBa, and NF-κB but did not affect the expression of ERK1/2 MAPKs or JNK MAPKs in LPS-stimulated zebrafish. Additionally, PHN regulated the MyD88/IκBα/NF-κB signalling pathway by controlling IκBα, IL-1β, IL-6, and TNF-α expression. Conclusion: This study provides a rationale for the clinical application of PHN as an anti-inflammatory agent.


2013 ◽  
Vol 144 (5) ◽  
pp. S-166-S-167
Author(s):  
Karen Boland ◽  
Caoimhin Concannon ◽  
Niamh McCawley ◽  
Elaine W. Kay ◽  
Deborah McNamara ◽  
...  

2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi6-vi6
Author(s):  
Takashi Fujii ◽  
Shun Yamamuro ◽  
Masamichi Takahashi ◽  
Akihide Kondo ◽  
Yoshitaka Narita ◽  
...  

Abstract The therapeutic outcome of glioblastomas (GBMs) is still very poor. Therefore, invention of novel therapeutic methods against GBM cases is considered urgent. The antitumor effects of naturally-derived compounds are attracting attention recently, and therapeutic efficacy of curcumin, a plant-derived compound previously used for multiple purpose, has been indicated in many cancer systems; however, clinical application of curcumin is considered difficult because of its poor bioavailability (under 1 %). Curcumin monoglucuronide (CMG), a water-soluble prodrug of curcumin recently developed for overcoming this weakness, has been demonstrated excellent antitumor effects for several malignancies in vitro and in vivo; therefore, we investigated the effects of CMG against GBM cells. CMG induced cell death of human GBM cells lines (T98G, U251MG, and U87MG) by dose dependent manner by triggering multiple forms of cell death such as apoptosis and perthanatos. Immunoblotting of CMG-treated GBM cell lysates demonstrated activation of multiple cell death signaling. Furthermore, immunodeficiency mice harboring intracerebral U87MG cell xenografts systemically treated by CMG showed significantly prolonged survival compared with control mice. These results suggest CMG would be a novel therapeutic agent against GBM cases.


Blood ◽  
1998 ◽  
Vol 91 (7) ◽  
pp. 2452-2458 ◽  
Author(s):  
Hiromichi Matsushita ◽  
Masahiro Kizaki ◽  
Hiroyuki Kobayashi ◽  
Hironori Ueno ◽  
Akihiro Muto ◽  
...  

Complete remission is achieved in a high proportion of patients with acute promyelocytic leukemia (APL) after all-trans retinoic acid (RA) treatment, but most patients relapse and develop RA-resistant APL. We have previously reported that both RA-resistant HL-60 (HL-60R) and APL cells express P-glycoprotein and MDR1 transcripts; and these cells differentiate to mature granulocytes after culture with RA and P-glycoprotein antagonist. Ribozymes have been shown to be able to intercept a target RNA by catalytic activity. To address the role of MDR1 in overcoming RA-resistance in APL cells, we investigated the biologic effects of ribozymes against the MDR1 transcript in HL-60R cells. These ribozymes efficiently cleaved MDR1 mRNA at a specific site in vitro. The 196 MDR1 ribozyme was cloned into an expression vector, and stably transfected (HL-60R/196Rz) cells were obtained. Expression of MDR1 transcripts was decreased in HL-60R/196Rz cells compared with parental HL-60R and empty vector-transfected (HL-60R/neo) cells. Interestingly, RA inhibited cellular proliferation and induced differentiation of HL-60R/196Rz cells in a dose-dependent manner, suggesting reversal of drug resistance in HL-60R cells by the MDR1 ribozyme. These data are direct evidence that P-glycoprotein/MDR1 is responsible in part for acquired resistance to RA in myeloid leukemic cells. The MDR1 ribozyme may be a useful tool for investigating the biology of retinoid resistance and may have therapeutic potential for patients with RA-resistant APL.


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