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    Hypochlorous acid selectively promotes toxicity and the expression of danger signals in human abdominal cancer cells
    (Athens : Spandidos Publ., 2021) Freund, Eric; Miebach, Lea; Stope, Matthias; Bekeschus, Sander
    Tumors of the abdominal cavity, such as colorectal, pancreatic and ovarian cancer, frequently metastasize into the peritoneum. Large numbers of metastatic nodules hinder cura- tive surgical resection, necessitating lavage with hyperthermic intraperitoneal chemotherapy (HIPEC). However, HIPEC not only causes severe side effects but also has limited therapeutic efficacy in various instances. At the same time, the age of immunotherapies such as biological agents, checkpoint- inhib- itors or immune-cell therapies, increasingly emphasizes the critical role of anticancer immunity in targeting malignancies. The present study investigated the ability of three types of long-lived reactive species (oxidants) to inactivate cancer cells and potentially complement current HIPEC regimens, as well as to increase tumor cell expression of danger signals that stimulate innate immunity. The human abdominal cancer cell lines HT-29, Panc-01 and SK-OV-3 were exposed to different concentrations of hydrogen peroxide (H2O2), hypochlorous acid (HOCl) and peroxynitrite (ONOO-). Metabolic activity was measured, as well as determination of cell death and danger signal expression levels via flow cytometry and detection of intracellular oxidation via high-content microscopy. Oxidation of tumor decreased intracellular levels of the antioxidant glutathione and induced oxidation in mitochondria, accompa- nied by a decrease in metabolic activity and an increase in regulated cell death. At similar concentrations, HOCl showed the most potent effects. Non-malignant HaCaT keratinocytes were less affected, suggesting the approach to be selective to some extent. Pro-immunogenic danger molecules were investi- gated by assessing the expression levels of calreticulin (CRT), and heat-shock protein (HSP)70 and HSP90. CRT expression was greatest following HOCl and ONOO- treatment, whereas HOCl and H2O2 resulted in the greatest increase in HSP70 and HSP90 expression levels. These results suggested that HOCl may be a promising agent to complement current HIPEC regi- mens targeting peritoneal carcinomatosis.
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    Biocompatible Gas Plasma Treatment Affects Secretion Profiles but Not Osteogenic Differentiation in Patient-Derived Mesenchymal Stromal Cells
    (Basel : Molecular Diversity Preservation International (MDPI), 2022) Fischer, Maximilian; Schoon, Janosch; Freund, Eric; Miebach, Lea; Weltmann, Klaus-Dieter; Bekeschus, Sander; Wassilew, Georgi I.
    Cold physical plasma (CPP), a partially ionized gas that simultaneously generates reactive oxygen and nitrogen species, is suggested to provide advantages in regenerative medicine. Intraoperative CPP therapy targeting pathologies related to diminished bone quality could be promising in orthopedic surgery. Assessment of a clinically approved plasma jet regarding cellular effects on primary bone marrow mesenchymal stromal cells (hBM-MSCs) from relevant arthroplasty patient cohorts is needed to establish CPP-based therapeutic approaches for bone regeneration. Thus, the aim of this study was to derive biocompatible doses of CPP and subsequent evaluation of human primary hBM-MSCs’ osteogenic and immunomodulatory potential. Metabolic activity and cell proliferation were affected in a treatment-time-dependent manner. Morphometric high content imaging analyses revealed a decline in mitochondria and nuclei content and increased cytoskeletal compactness following CPP exposure. Employing a nontoxic exposure regime, investigation on osteogenic differentiation did not enhance osteogenic capacity of hBM-MSCs. Multiplex analysis of major hBM-MSC cytokines, chemokines and growth factors revealed an anti-inflammatory, promatrix-assembling and osteoclast-regulating secretion profile following CPP treatment and osteogenic stimulus. This study can be noted as the first in vitro study addressing the influence of CPP on hBM-MSCs from individual donors of an arthroplasty clientele.
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    Patient-derived human basal and cutaneous squamous cell carcinoma tissues display apoptosis and immunomodulation following gas plasma exposure with a certified argon jet
    (Basel : Molecular Diversity Preservation International, 2021) Saadati, Fariba; Moritz, Juliane; Berner, Julia; Freund, Eric; Miebach, Lea; Helfrich, Iris; Stoffels, Ingo; Emmert, Steffen; Bekeschus, Sander
    Reactive oxygen species (ROS) have been subject of increasing interest in the pathophysiology and therapy of cancers in recent years. In skin cancer, ROS are involved in UV-induced tumorigenesis and its targeted treatment via, e.g., photodynamic therapy. Another recent technology for topical ROS generation is cold physical plasma, a partially ionized gas expelling dozens of reactive species onto its treatment target. Gas plasma technology is accredited for its wound-healing abilities in Europe, and current clinical evidence suggests that it may have beneficial effects against actinic keratosis. Since the concept of hormesis dictates that low ROS levels perform signaling functions, while high ROS levels cause damage, we investigated herein the antitumor activity of gas plasma in non-melanoma skin cancer. In vitro, gas plasma exposure diminished the metabolic activity, preferentially in squamous cell carcinoma cell (SCC) lines compared to non-malignant HaCaT cells. In patient-derived basal cell carcinoma (BCC) and SCC samples treated with gas plasma ex vivo, increased apoptosis was found in both cancer types. Moreover, the immunomodulatory actions of gas plasma treatment were found affecting, e.g., the expression of CD86 and the number of regulatory T-cells. The supernatants of these ex vivo cultured tumors were quantitatively screened for cytokines, chemokines, and growth factors, identifying CCL5 and GM-CSF, molecules associated with skin cancer metastasis, to be markedly decreased. These findings suggest gas plasma treatment to be an interesting future technology for non-melanoma skin cancer topical therapy.