ROCK2 interacts with p22phox to phosphorylate p47phox and to control NADPH oxidase activation in human monocytes

NCF-1 plays a pivotal role in the survival of adenocarcinoma cells of pancreatic and gastric origins

Reactive oxygen species (ROS) play a pivotal biological role in cells, with ROS function differing depending on cellular conditions and the extracellular environment. Notably, ROS act as cytotoxic factors to eliminate infectious pathogens or promote cell death under cellular stress, while also facilitating cell growth (via ROS-sensing pathways) by modifying gene expression. Among ROS-related genes, neutrophil cytosolic factor-1 (NCF-1; p47phox) was identified as a ROS generator in neutrophils. This product is a subunit of a cytosolic NADPH oxidase complex activated in response to pathogens such as bacteria and viruses. NCF-1 has been examined primarily in terms of ROS-production pathways in macrophages and neutrophils; however, the expression of this protein and its biological role in cancer cells remain unclear. Here, we report expression of NCF-1 in pancreatic and gastric cancers, and demonstrate its biological significance in these tumor cells. Abundant expression of NCF-1 was observed in pancreatic adenocarcinoma (PDAC) lines and in patient tissues, as well as in gastric adenocarcinomas. Accumulation of the protein was also detected in the invasive/metastatic foci of these tumors. Unexpectedly, BxPC-3 underwent apoptotic cell death when transfected with a small interfering RNA (siRNA) specific to NCF-1, whereas the cells treated with a control siRNA proliferated in a time-dependent manner. A similar phenomenon was observed in HSC-58, a poorly differentiated gastric adenocarcinoma line. Consequently, the tumor cells highly expressing NCF-1 obtained coincident accumulation of ROS and reduced glutathione (GSH) with expression of glutathione peroxidase 4 (GPX4), a quencher involved in ferroptosis. Unlike the conventional role of ROS as a representative cytotoxic factor, these findings suggest that NCF-1-mediated ROS generation may be required for expansive growth of PDAC and gastric cancers.

Insights into Alkaline Phosphatase Anti-Inflammatory Mechanisms

BACKGROUND

The endogenous ecto-enzyme and exogenously administered alkaline phosphatase (ALP) have been evidenced to significantly attenuate inflammatory conditions, including Toll-like receptor 4 (TLR4)-related signaling and cytokine overexpression, barrier tissue dysfunction and oxidative stress, and metabolic syndrome and insulin resistance, in experimental models of colitis, liver failure, and renal and cardiac ischemia-reperfusion injury. This suggests multiple mechanisms of ALP anti-inflammatory action that remain to be fully elucidated.

METHODS

Recent studies have contributed to a deeper comprehension of the role played by ALP in immune metabolism. This review outlines the established effects of ALP on lipopolysaccharide (LPS)-induced inflammation, including the neutralization of LPS and the modulation of purinergic signaling.

RESULTS

The additional mechanisms of anti-inflammatory activity of ALP observed in different pathologies are proposed.

CONCLUSIONS

The anti-inflammatory pathways of ALP may include a scavenger receptor (CD36)-mediated activation of β-oxidation and oxidative phosphorylation, caveolin-dependent endocytosis, and selective autophagy-dependent degradation.

Free Radical Inhibition Using a Water-Soluble Curcumin Complex, NDS27: Mechanism Study Using EPR, Chemiluminescence, and Docking

There is a growing interest in the use of natural compounds to tackle inflammatory diseases and cancers. However, most of them face the bioavailability and solubility challenges to reaching cellular compartments and exert their potential biological effects. Polyphenols belong to that class of molecules, and numerous efforts have been made to improve and overcome these problems. Curcumin is widely studied for its antioxidant and anti-inflammatory properties as well as its use as an anticancer agent. However, its poor solubility and bioavailability are often a source of concern with disappointing or unexpected results in cellular models or in vivo, which limits the clinical use of curcumin as such. Beside nanoparticles and liposomes, cyclodextrins are one of the best candidates to improve the solubility of these molecules. We have used lysine and cyclodextrin to form a water-soluble curcumin complex, named NDS27, in which potential anti-inflammatory effects were demonstrated in cellular and in vivo models. Herein, we investigated for the first time its direct free radicals scavenging activity on DPPH/ABTS assays as well as on hydroxyl, superoxide anion, and peroxyl radical species. The ability of NDS27 to quench singlet oxygen, produced by rose bengal photosensitization, was studied, as was the inhibiting effect on the enzyme-catalyzed oxidation of the co-substrate, luminol analog (L012), using horseradish peroxidase (HRP)/hydrogen peroxide (H2O2) system. Finally, docking was performed to study the behavior of NDS27 in the active site of the peroxidase enzyme.

Tumour-associated macrophages: versatile players in the tumour microenvironment

Tumour-Associated Macrophages (TAMs) are one of the pivotal components of the tumour microenvironment. Their roles in the cancer immunity are complicated, both pro-tumour and anti-cancer activities are reported, including not only angiogenesis, extracellular matrix remodeling, immunosuppression, drug resistance but also phagocytosis and tumour regression. Interestingly, TAMs are highly dynamic and versatile in solid tumours. They show anti-cancer or pro-tumour activities, and interplay between the tumour microenvironment and cancer stem cells and under specific conditions. In addition to the classic M1/M2 phenotypes, a number of novel dedifferentiation phenomena of TAMs are discovered due to the advanced single-cell technology, e.g., macrophage-myofibroblast transition (MMT) and macrophage-neuron transition (MNT). More importantly, emerging information demonstrated the potential of TAMs on cancer immunotherapy, suggesting by the therapeutic efficiency of the checkpoint inhibitors and chimeric antigen receptor engineered cells based on macrophages. Here, we summarized the latest discoveries of TAMs from basic and translational research and discussed their clinical relevance and therapeutic potential for solid cancers.