scholarly journals Enzyme prodrug therapy: cytotoxic potential of paracetamol turnover with recombinant horseradish peroxidase

2021 ◽  
Author(s):  
Diana Humer ◽  
Oliver Spadiut
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Radical Reaction ◽  
Squamous Carcinoma ◽  
The Body ◽  
Human Immune System ◽  
Glycosylation Pattern ◽  
Enzyme Prodrug Therapy ◽  
Benzoquinone Imine ◽  
Squamous Carcinoma Cells

AbstractTargeted cancer treatment is a promising, less invasive alternative to chemotherapy as it is precisely directed against tumor cells whilst leaving healthy tissue unaffected. The plant-derived enzyme horseradish peroxidase (HRP) can be used for enzyme prodrug cancer therapy with indole-3-acetic acid or the analgesic paracetamol (acetaminophen). Oxidation of paracetamol by HRP in the presence of hydrogen peroxide leads to N-acetyl-p-benzoquinone imine and polymer formation via a radical reaction mechanism. N-acetyl-p-benzoquinone imine binds to DNA and proteins, resulting in severe cytotoxicity. However, plant HRP is not suitable for this application since the foreign glycosylation pattern is recognized by the human immune system, causing rapid clearance from the body. Furthermore, plant-derived HRP is a mixture of isoenzymes with a heterogeneous composition. Here, we investigated the reaction of paracetamol with defined recombinant HRP variants produced in E. coli, as well as plant HRP, and found that they are equally effective in paracetamol oxidation at a concentration ≥ 400 µM. At low paracetamol concentrations, however, recombinant HRP seems to be more efficient in paracetamol oxidation. Yet upon treatment of HCT-116 colon carcinoma and FaDu squamous carcinoma cells with HRP–paracetamol no cytotoxic effect was observed, neither in the presence nor absence of hydrogen peroxide. Graphic abstract

Utilizing ICG Spectroscopical Properties for Real-Time Nanoparticle Release Quantification In vitro and In vivo in Imaging Setups

2020 ◽  
Vol 26 (31) ◽  
pp. 3828-3833 ◽  
Author(s):  
Tuula Peñate-Medina ◽  
Eike Kraas ◽  
Kunliang Luo ◽  
Jana Humbert ◽  
Hanwen Zhu ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Pure Water ◽  
Squamous Carcinoma ◽  
Peak Shift ◽  
Intensity Increase ◽  
Nude Mouse Model ◽  
Absorption And Emission ◽  
Squamous Carcinoma Cells

Background: Nanoparticle imaging and tracking the release of the loaded material from the nanoparticle system have attracted significant attention in recent years. If the release of the loaded molecules could be monitored reliably in vivo, it would speed up the development of drug delivery systems remarkably. Methods: Here, we test a system that uses indocyanine green (ICG) as a fluorescent agent for studying release kinetics in vitro and in vivo from the lipid iron nanoparticle delivery system. The ICG spectral properties like its concentration dependence, sensitivity and the fluctuation of the absorption and emission wavelengths can be utilized for gathering information about the change of the ICG surrounding. Results: We have found that the absorption, fluorescence, and photoacoustic spectra of ICG in lipid iron nanoparticles differ from the spectra of ICG in pure water and plasma. We followed the ICG containing liposomal nanoparticle uptake into squamous carcinoma cells (SCC) by fluorescence microscopy and the in vivo uptake into SCC tumors in an orthotopic xenograft nude mouse model under a surgical microscope. Conclusion: Absorption and emission properties of ICG in the different solvent environment, like in plasma and human serum albumin, differ from those in aqueous solution. Photoacoustic spectral imaging confirmed a peak shift towards longer wavelengths and an intensity increase of ICG when bound to the lipids. The SCC cells showed that the ICG containing liposomes bind to the cell surface but are not internalized in the SCC-9 cells after 60 minutes of incubation. We also showed here that ICG containing liposomal nanoparticles can be traced under a surgical camera in vivo in orthotopic SCC xenografts in mice.

scholarly journals Rap1a Overlaps the AGE/RAGE Signaling Cascade to Alter Expression of α-SMA, p-NF-κB, and p-PKC-ζ in Cardiac Fibroblasts Isolated from Type 2 Diabetic Mice

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 557
Author(s):  
Stephanie D. Burr ◽  
James A. Stewart
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Hydrogen Peroxide ◽  
Cardiac Fibroblasts ◽  
The Body ◽  
Signaling Cascade ◽  
Diabetic Mice ◽  
Pkc Ζ ◽  
Type 2 Diabetic

Cardiovascular disease, specifically heart failure, is a common complication for individuals with type 2 diabetes mellitus. Heart failure can arise with stiffening of the left ventricle, which can be caused by “active” cardiac fibroblasts (i.e., myofibroblasts) remodeling the extracellular matrix (ECM). Differentiation of fibroblasts to myofibroblasts has been demonstrated to be an outcome of AGE/RAGE signaling. Hyperglycemia causes advanced glycated end products (AGEs) to accumulate within the body, and this process is greatly accelerated under chronic diabetic conditions. AGEs can bind and activate their receptor (RAGE) to trigger multiple downstream outcomes, such as altering ECM remodeling, inflammation, and oxidative stress. Previously, our lab has identified a small GTPase, Rap1a, that possibly overlaps the AGE/RAGE signaling cascade to affect the downstream outcomes. Rap1a acts as a molecular switch connecting extracellular signals to intracellular responses. Therefore, we hypothesized that Rap1a crosses the AGE/RAGE cascade to alter the expression of AGE/RAGE associated signaling proteins in cardiac fibroblasts in type 2 diabetic mice. To delineate this cascade, we used genetically different cardiac fibroblasts from non-diabetic, diabetic, non-diabetic RAGE knockout, diabetic RAGE knockout, and Rap1a knockout mice and treated them with pharmacological modifiers (exogenous AGEs, EPAC, Rap1a siRNA, and pseudosubstrate PKC-ζ). We examined changes in expression of proteins implicated as markers for myofibroblasts (α-SMA) and inflammation/oxidative stress (NF-κB and SOD-1). In addition, oxidative stress was also assessed by measuring hydrogen peroxide concentration. Our results indicated that Rap1a connects to the AGE/RAGE cascade to promote and maintain α-SMA expression in cardiac fibroblasts. Moreover, Rap1a, in conjunction with activation of the AGE/RAGE cascade, increased NF-κB expression as well as hydrogen peroxide concentration, indicating a possible oxidative stress response. Additionally, knocking down Rap1a expression resulted in an increase in SOD-1 expression suggesting that Rap1a can affect oxidative stress markers independently of the AGE/RAGE signaling cascade. These results demonstrated that Rap1a contributes to the myofibroblast population within the heart via AGE/RAGE signaling as well as promotes possible oxidative stress. This study offers a new potential therapeutic target that could possibly reduce the risk for developing diabetic cardiovascular complications attributed to AGE/RAGE signaling.

scholarly journals Cytotoxic Influence of Khat (Catha edulis (Vahl) Forssk. ex Endl) on Oral Fibroblasts, Squamous Carcinoma Cells, and Expression of α Smooth Muscle Actin

2021 ◽  
Vol 11 (8) ◽  
pp. 3524
Author(s):  
Azeem Ul Yaqin Syed ◽  
Muhammad A. Ahmed ◽  
Eman I. AlSagob ◽  
Mansour Al-Askar ◽  
Abdulrahman M. AlMubarak ◽  
...  
Keyword(s):  
Cell Death ◽  
Smooth Muscle ◽  
Smooth Muscle Actin ◽  
Control Cell ◽  
Squamous Carcinoma ◽  
Carcinoma Cells ◽  
Muscle Actin ◽  
Catha Edulis ◽  
Squamous Carcinoma Cells ◽  
Dose Dependent

The aim was to determine the cytotoxicity of Khat (Catha edulis (Vahl) Forssk. ex Endl) on normal oral fibroblasts (NOFs) and SCC4 (squamous carcinoma cells) along with expression of α-smooth muscle actin (α-SMA) in fibroblasts. Khat filtrate was prepared to obtain a concentrated viscous solution. NOFs and SCC4 cells were cultured in biological cabinets and were grown in Dulbeccos’ modified Eagles medium. Frozen cells were thawed at 37 °C and cell seeding was performed. NOFs and SCC4 cells were seeded on 96 well plates and allowed to attach. The medium was removed and a fresh medium containing different concentrations of Khat was added. The group without Khat served as a negative control and 4% paraformaldehyde as the positive control. Cell viability was assessed using the MTT assay and effect of Khat on fibroblast and SCC4 phenotypes was evaluated by immunostaining. Analysis of variance was used to assess data (p < 0.05). NOF 316 showed cell death in response to 4% paraformaldehyde, 12.5, 6.25, and 3.12 mg/mL of Khat. The highest concentration of Khat (25 mg/mL) failed to cause cytotoxicity of NOF 316. NOF 319 and NOF 26 displayed cell death at all concentrations of Khat, however, cytotoxicity was not dose dependent. NOF 18 and SCC4 cells showed dose-dependent cell death. NOF 316 showed α-SMA expression after 1 mg/mL of Khat exposure. Not all fibroblasts were α-SMA-positive, suggesting specific activation of a subset of fibroblasts. Khat is cytotoxic to NOF and SCC4 cells. Furthermore, it can also cause activation and phenotypic changes in oral fibroblasts, indicating a potential role in progression of oral squamous cell carcinoma.

scholarly journals Monitoring the heme iron state in horseradish peroxidase to detect ultratrace amounts of hydrogen peroxide in alcohols

RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9901-9910
Author(s):  
Raheleh Ravanfar ◽  
Alireza Abbaspourrad
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Oxidative Damage ◽  
Heme Iron ◽  
Aqueous Systems ◽  
Iron State ◽  
Low Concentrations

Despite the importance of hydrogen peroxide (H2O2) in initiating oxidative damage and its connection to various diseases, the detection of low concentrations of H2O2 (<10 μM) is still limited using current methods, particularly in non-aqueous systems.

scholarly journals The Reaction of Ferrous Horseradish Peroxidase with Hydrogen Peroxide

1970 ◽  
Vol 245 (9) ◽  
pp. 2409-2413
Author(s):  
Robert W. Noble ◽  
Quentin H. Gibson
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase

Upregulation of HO-1 is accompanied by activation of p38MAPK and mTOR in human oesophageal squamous carcinoma cells

2013 ◽  
Vol 37 (6) ◽  
pp. 584-592 ◽  
Author(s):  
Jian-Li Hu ◽  
Lan Xiao ◽  
Zhen-Yun Li ◽  
Qiong Wang ◽  
Yu Chang ◽  
...  
Keyword(s):  
Squamous Carcinoma ◽  
Carcinoma Cells ◽  
Squamous Carcinoma Cells
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