scholarly journals Changes in Plant Mitochondrial Electron Transport Alter Cellular Levels of Reactive Oxygen Species and Susceptibility to Cell Death Signaling Molecules

2006 ◽  
Vol 47 (11) ◽  
pp. 1509-1519 ◽  
Author(s):  
Sasan Amirsadeghi ◽  
Christine A. Robson ◽  
Allison E. McDonald ◽  
Greg C. Vanlerberghe
2006 ◽  
Vol 282 (7) ◽  
pp. 4868-4874 ◽  
Author(s):  
Gregory D. Fairn ◽  
Kendra MacDonald ◽  
Christopher R. McMaster

The isoprenoid farnesol has been shown to preferentially induce apoptosis in cancerous cells; however, the mode of action of farnesol-induced death is not established. We used chemogenomic profiling using Saccharomyces cerevisiae to probe the core cellular processes targeted by farnesol. This screen revealed 48 genes whose inactivation increased sensitivity to farnesol. The gene set indicated a role for the generation of oxygen radicals by the Rieske iron-sulfur component of complex III of the electron transport chain as a major mediator of farnesol-induced cell death. Consistent with this, loss of mitochondrial DNA, which abolishes electron transport, resulted in robust resistance to farnesol. A genomic interaction map predicted interconnectedness between the Pkc1 signaling pathway and farnesol sensitivity via regulation of the generation of reactive oxygen species. Consistent with this prediction (i) Pkc1, Bck1, and Mkk1 relocalized to the mitochondria upon farnesol addition, (ii) inactivation of the only non-essential and non-redundant member of the Pkc1 signaling pathway, BCK1, resulted in farnesol sensitivity, and (iii) expression of activated alleles of PKC1, BCK1, and MKK1 increased resistance to farnesol and hydrogen peroxide. Sensitivity to farnesol was not affected by the presence of the osmostabilizer sorbitol nor did farnesol affect phosphorylation of the ultimate Pkc1-responsive kinase responsible for controlling the cell wall integrity pathway, Slt2. The data indicate that the generation of reactive oxygen species by the electron transport chain is a primary mechanism by which farnesol kills cells. The Pkc1 signaling pathway regulates farnesol-mediated cell death through management of the generation of reactive oxygen species.


Biochimie ◽  
2002 ◽  
Vol 84 (2-3) ◽  
pp. 131-141 ◽  
Author(s):  
Christophe Fleury ◽  
Bernard Mignotte ◽  
Jean-Luc Vayssière

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Michal Čáp ◽  
Libuše Váchová ◽  
Zdena Palková

One of the universal traits of microorganisms is their ability to form multicellular structures, the cells of which differentiate and communicate via various signaling molecules. Reactive oxygen species (ROS), and hydrogen peroxide in particular, have recently become well-established signaling molecules in higher eukaryotes, but still little is known about the regulatory functions of ROS in microbial structures. Here we summarize current knowledge on the possible roles of ROS during the development of colonies and biofilms, representatives of microbial multicellularity. InSaccharomyces cerevisiaecolonies, ROS are predicted to participate in regulatory events involved in the induction of ammonia signaling and later on in programmed cell death in the colony center. While the latter process seems to be induced by the total ROS, the former event is likely to be regulated by ROS-homeostasis, possibly H2O2-homeostasis between the cytosol and mitochondria. InCandida albicansbiofilms, the predicted signaling role of ROS is linked with quorum sensing molecule farnesol that significantly affects biofilm formation. In bacterial biofilms, ROS induce genetic variability, promote cell death in specific biofilm regions, and possibly regulate biofilm development. Thus, the number of examples suggesting ROS as signaling molecules and effectors in the development of microbial multicellularity is rapidly increasing.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Amnah M. Alshangiti ◽  
Eszter Tuboly ◽  
Shane V. Hegarty ◽  
Cathal M. McCarthy ◽  
Aideen M. Sullivan ◽  
...  

Neuroblastoma is an embryonal malignancy that arises from cells of sympathoadrenal lineage during the development of the nervous system. It is the most common pediatric extracranial solid tumor and is responsible for 15% of childhood deaths from cancer. Fifty percent of cases are diagnosed as high-risk metastatic disease with a low overall 5-year survival rate. More than half of patients experience disease recurrence that can be refractory to treatment. Amplification of the MYCN gene is an important prognostic indicator that is associated with rapid disease progression and a poor prognosis, highlighting the need for new therapeutic approaches. In recent years, there has been an increasing focus on identifying anticancer properties of naturally occurring chalcones, which are secondary metabolites with variable phenolic structures. Here, we report that 4-hydroxychalcone is a potent cytotoxin for MYCN-amplified IMR-32 and SK-N-BE (2) neuroblastoma cells, when compared to non-MYCN-amplified SH-SY5Y neuroblastoma cells and to the non-neuroblastoma human embryonic kidney cell line, HEK293t. Moreover, 4-hydroxychalcone treatment significantly decreased cellular levels of the antioxidant glutathione and increased cellular reactive oxygen species. In addition, 4-hydroxychalcone treatment led to impairments in mitochondrial respiratory function, compared to controls. In support of this, the cytotoxic effect of 4-hydroxychalcone was prevented by co-treatment with either the antioxidant N-acetyl-L-cysteine, a pharmacological inhibitor of oxidative stress-induced cell death (IM-54) or the mitochondrial reactive oxygen species scavenger, Mito-TEMPO. When combined with the anticancer drugs cisplatin or doxorubicin, 4-hydroxychalcone led to greater reductions in cell viability than was induced by either anti-cancer agent alone. In summary, this study identifies a cytotoxic effect of 4-hydroxychalcone in MYCN-amplified human neuroblastoma cells, which rationalizes its further study in the development of new therapies for pediatric neuroblastoma.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Shashank Hambarde ◽  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar

Abstract Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.


Sign in / Sign up

Export Citation Format

Share Document