scholarly journals The Chemopreventive Agent Curcumin Is a Potent Radiosensitizer of Human Cervical Tumor Cells via Increased Reactive Oxygen Species Production and Overactivation of the Mitogen-Activated Protein Kinase Pathway

2008 ◽  
Vol 73 (5) ◽  
pp. 1491-1501 ◽  
Author(s):  
Prashanthi Javvadi ◽  
Andrew T. Segan ◽  
Stephen W. Tuttle ◽  
Constantinos Koumenis
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Kinase ◽  
Reactive Oxygen Species Production ◽  
Mitogen Activated Protein Kinase ◽  
Oxygen Species ◽  
Cervical Tumor ◽  
Chemopreventive Agent ◽  
Mitogen Activated Protein ◽  
Species Production ◽  
Kinase Pathway

scholarly journals Differential regulation of AMP-activated protein kinase in healthy and cancer cells explains why V-ATPase inhibition selectively kills cancer cells

2019 ◽  
Vol 294 (46) ◽  
pp. 17239-17248
Author(s):  
Karin Bartel ◽  
Rolf Müller ◽  
Karin von Schwarzenberg
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Reactive Oxygen Species Production ◽  
Differential Regulation ◽  
Oxygen Species ◽  
Atpase Inhibitors ◽  
Species Production ◽  
Amp Activated Protein Kinase ◽  
Atpase Inhibition

The cellular energy sensor AMP-activated protein kinase (AMPK) is a metabolic hub regulating various pathways involved in tumor metabolism. Here we report that vacuolar H+-ATPase (V-ATPase) inhibition differentially affects regulation of AMPK in tumor and nontumor cells and that this differential regulation contributes to the selectivity of V-ATPase inhibitors for tumor cells. In nonmalignant cells, the V-ATPase inhibitor archazolid increased phosphorylation and lysosomal localization of AMPK. We noted that AMPK localization has a prosurvival role, as AMPK silencing decreased cellular growth rates. In contrast, in cancer cells, we found that AMPK is constitutively active and that archazolid does not affect its phosphorylation and localization. Moreover, V-ATPase–independent AMPK induction in tumor cells protected them from archazolid-induced cytotoxicity, further underlining the role of AMPK as a prosurvival mediator. These observations indicate that AMPK regulation is uncoupled from V-ATPase activity in cancer cells and that this makes them more susceptible to cell death induction by V-ATPase inhibitors. In both tumor and healthy cells, V-ATPase inhibition induced a distinct metabolic regulatory cascade downstream of AMPK, affecting ATP and NADPH levels, glucose uptake, and reactive oxygen species production. We could attribute the prosurvival effects to AMPK's ability to maintain redox homeostasis by inhibiting reactive oxygen species production and maintaining NADPH levels. In summary, the results of our work indicate that V-ATPase inhibition has differential effects on AMPK-mediated metabolic regulation in cancer and healthy cells and explain the tumor-specific cytotoxicity of V-ATPase inhibition.

scholarly journals Role of Reactive Oxygen Species in Cancer Progression: Molecular Mechanisms and Recent Advancements

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 735 ◽  
Author(s):  
Vaishali Aggarwal ◽  
Hardeep Tuli ◽  
Ayşegül Varol ◽  
Falak Thakral ◽  
Mukerrem Yerer ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Kinase ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Reactive Oxygen ◽  
Mitogen Activated Protein Kinase ◽  
Oxygen Species ◽  
Mitogen Activated Protein ◽  
High Concentrations

Reactive oxygen species (ROS) play a pivotal role in biological processes and continuous ROS production in normal cells is controlled by the appropriate regulation between the silver lining of low and high ROS concentration mediated effects. Interestingly, ROS also dynamically influences the tumor microenvironment and is known to initiate cancer angiogenesis, metastasis, and survival at different concentrations. At moderate concentration, ROS activates the cancer cell survival signaling cascade involving mitogen-activated protein kinase/extracellular signal-regulated protein kinases 1/2 (MAPK/ERK1/2), p38, c-Jun N-terminal kinase (JNK), and phosphoinositide-3-kinase/ protein kinase B (PI3K/Akt), which in turn activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), matrix metalloproteinases (MMPs), and vascular endothelial growth factor (VEGF). At high concentrations, ROS can cause cancer cell apoptosis. Hence, it critically depends upon the ROS levels, to either augment tumorigenesis or lead to apoptosis. The major issue is targeting the dual actions of ROS effectively with respect to the concentration bias, which needs to be monitored carefully to impede tumor angiogenesis and metastasis for ROS to serve as potential therapeutic targets exogenously/endogenously. Overall, additional research is required to comprehend the potential of ROS as an effective anti-tumor modality and therapeutic target for treating malignancies.

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