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1.
Clin Transplant ; 38(7): e15383, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39023092

ABSTRACT

BACKGROUND: Antibody-mediated rejection (ABMR) poses a barrier to long-term graft survival and is one of the most challenging events after kidney transplantation. Removing donor specific antibodies (DSA) through therapeutic plasma exchange (PLEX) is a cornerstone of antibody depletion but has inconsistent effects. Imlifidase is a treatment currently utilized for desensitization with near-complete inactivation of DSA both in the intra- and extravascular space. METHODS: This was a 6-month, randomized, open-label, multicenter, multinational trial conducted at 14 transplant centers. Thirty patients were randomized to either imlifidase or PLEX treatment. The primary endpoint was reduction in DSA level during the 5 days following the start of treatment. RESULTS: Despite considerable heterogeneity in the trial population, DSA reduction as defined by the primary endpoint was 97% for imlifidase compared to 42% for PLEX. Additionally, imlifidase reduced DSA to noncomplement fixing levels, whereas PLEX failed to do so. After antibody rebound in the imlifidase arm (circa days 6-12), both arms had similar reductions in DSA. Five allograft losses occurred during the 6 months following the start of ABMR treatment-four within the imlifidase arm (18 patients treated) and one in the PLEX arm (10 patients treated). In terms of clinical efficacy, the Kaplan-Meier estimated graft survival was 78% for imlifidase and 89% for PLEX, with a slightly higher eGFR in the PLEX arm at the end of the trial. The observed adverse events in the trial were as expected, and there were no apparent differences between the arms. CONCLUSION: Imlifidase was safe and well-tolerated in the ABMR population. Despite meeting the primary endpoint of maximum DSA reduction compared to PLEX, the trial was unsuccessful in demonstrating a clinical benefit of imlifidase in this heterogenous ABMR population. TRIAL REGISTRATION: EudraCT number: 2018-000022-66, 2020-004777-49; ClinicalTrials.gov identifier: NCT03897205, NCT04711850.


Subject(s)
Graft Rejection , Graft Survival , Isoantibodies , Kidney Failure, Chronic , Kidney Transplantation , Plasmapheresis , Humans , Graft Rejection/etiology , Graft Rejection/immunology , Graft Rejection/prevention & control , Female , Male , Middle Aged , Follow-Up Studies , Isoantibodies/blood , Isoantibodies/immunology , Adult , Prognosis , Kidney Failure, Chronic/surgery , Kidney Failure, Chronic/therapy , Kidney Function Tests , Postoperative Complications , Glomerular Filtration Rate , Risk Factors , Transplant Recipients
2.
Macromol Biosci ; : e2400213, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38899954

ABSTRACT

Cold atmospheric plasma (CAP) is a tool with the ability to generate reactive oxygen and nitrogen species (RONS), which can induce therapeutic effects like disinfection, wound healing, and cancer treatment. In the plasma oncology field, CAP-treated hydrogels (PTHs) are being explored for the local administration of CAP-derived RONS as a novel anticancer approach. PTHs have shown anticancer effects in vitro, however, they have not yet been studied in more relevant cancer models. In this context, the present study explores for the first time the therapeutic potential of PTHs using an advanced in ovo cancer model. PTHs composed of alginate (Alg), gelatin (Gel), Alg/Gel combination, or Alg/hyaluronic acid (HA) combination are investigated. All embryos survived the PTHs treatment, suggesting that the in ovo model could become a time- and cost-effective tool for developing hydrogel-based anticancer approaches. Results revealed a notable reduction in CD44+ cell population and their proliferative state for the CAP-treated Alg-HA condition. Moreover, the CAP-treated Alg-HA formulation alters the extracellular matrix composition, which may help combat drug-resistance. In conclusion, the present study validates the utility of in ovo cancer model for PTHs exploration and highlights the promising potential of Alg-based PTHs containing HA and CAP-derived RONS for cancer treatment.

3.
Am J Primatol ; 86(3): e23501, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37170705

ABSTRACT

The majority of the 11 species of owl monkeys (Aotus spp.) have declining populations or are listed as data deficient. Deforestation due to agriculture, development, or logging poses threats to owl monkeys throughout their range. In some areas, Aotus are hunted for bushmeat or trapped for the wildlife trade. In Colombia, the country with the greatest number of Aotus species, owl monkeys are also threatened by civil unrest. To help combat these challenges, nonprofit organizations and field researchers in habitat countries have successfully implemented a variety of conservation projects such as censusing and monitoring owl monkey populations, establishing protected areas, reforesting degraded areas, filing lawsuits to protect wild populations, helping law enforcement with environmental regulation, and promoting environmental education. We highlight some of the conservation successes and suggest actions people around the world can take to contribute to these important efforts.


Subject(s)
Aotidae , Animals , Aotidae/physiology
4.
Minerva Surg ; 78(6): 671-683, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38059441

ABSTRACT

Being an underdiagnosed and under or insufficiently treated condition, surgical pancreatic exocrine insufficiency (PSP) is the condition in which pancreatic enzymes are insufficient for digestion because of gastrointestinal (GI) surgery involving the upper GI tract, biliary ducts, or the pancreas, and and leading to potential malnutrition and deterioration in quality of life. Age, obesity, history of tobacco use, family history of diabetes, surgery due to a malignant tumor, presence of steatorrhea, jaundice, weight loss, and intraoperative findings of hard pancreatic texture have been associated with a higher risk of PSP. Pancreatoduodectomy (PD) has demonstrated an increased risk of developing PSP, with a prevalence between 19-100%. Distal pancreatectomy (DP) and central pancreatectomy (CenP) are associated with less risk of PSP, with a prevalence of 0-82% and 3.66-8.7%, respectively. In patients with chronic pancreatitis (CP), PSP was associated with 80% in Partington-Rochelle procedure, 86% in Frey procedure, 80% in duodenum preserving pancreatic head procedure, >60% in PD and 27.5-63% in DP. Fecal elastase-1 (FE-1) is a generally accepted tool for diagnosis. Treatment is recommended to start as soon as a diagnosis is achieved, or clinical suspicion is high. Pancreatic enzyme replacement therapy improves symptoms of malabsorption, facilitates weight gain, and ultimately improves patients' quality of life. Starting dosage is between 10,000-50,000 units in snacks and 50,000-75,000 units in main meals, administered throughout food intake, though further data specifically on PSP are needed. Follow-up in PSP is recommended on an on-demand basis, where malnutrition should be assessed.


Subject(s)
Exocrine Pancreatic Insufficiency , Malnutrition , Humans , Quality of Life , Exocrine Pancreatic Insufficiency/epidemiology , Exocrine Pancreatic Insufficiency/etiology , Exocrine Pancreatic Insufficiency/diagnosis , Pancreas , Pancreatectomy/adverse effects , Pancreatectomy/methods , Malnutrition/diagnosis , Malnutrition/epidemiology , Malnutrition/complications
6.
Antioxidants (Basel) ; 12(6)2023 May 29.
Article in English | MEDLINE | ID: mdl-37371905

ABSTRACT

Olive pomace is a by-product of olive oil production that is toxic to the environment. The purpose of this study was to evaluate the methods of olive pomace valorization through the implementation of novel technology, the so-called microwave-assisted extraction process. To determine the total polyphenol content (TPC) and antioxidant activity (AA), polyphenol extraction using MAE was performed. Response surface methodology was used to determine the best extraction conditions, whereby the effects of three factors, solid ratio (g/50 mL), time (s), and power (W), were measured. The ferric reducing antioxidant power (FRAP) method was used to assess AA, whereas the spectrophotometric Folin-Ciocalteu (FC) method was used to determine TPC. The highest TPC of 15.30 mg of gallic acid equivalents per gram of dried weight (mg GAE/gdw) was generated after 105 s at 450 W, with a solid concentration of 1 g/50 mL, while the maximum AA was 10 mg of ascorbic acid equivalents per gram of dried weight (mg AAE/gdw). Numerical optimization revealed that 800 W, 180 s, and 1 g/50 mL were the best conditions for obtaining maximum TPC and AA.

7.
ACS Sustain Chem Eng ; 11(13): 5206-5215, 2023 Apr 03.
Article in English | MEDLINE | ID: mdl-37034498

ABSTRACT

As recently highlighted by the SARS-CoV-2 pandemic, viruses have become an increasing burden for health, global economy, and environment. The control of transmission by contact with contaminated materials represents a major challenge, particularly in hospital environments. However, the current disinfection methods in hospital settings suffer from numerous drawbacks. As a result, several medical supplies that cannot be properly disinfected are not reused, leading to severe shortages and increasing amounts of waste, thus prompting the search for alternative solutions. In this work, we report that non-thermal plasma (NTP) can effectively inactivate SARS-CoV-2 from non-porous and porous materials commonly found in healthcare facilities. We demonstrated that 5 min treatment with a dielectric barrier discharge NTP can inactivate 100% of SARS-CoV-2 (Wuhan and Omicron strains) from plastic material. Using porcine respiratory coronavirus (surrogate for SARS-CoV-2) and coxsackievirus B3 (highly resistant non-enveloped virus), we tested the NTP virucidal activity on hospital materials and obtained complete inactivation after 5 and 10 min, respectively. We hypothesize that the produced reactive species and local acidification contribute to the overall virucidal effect of NTP. Our results demonstrate the potential of dielectric barrier discharge NTPs for the rapid, efficient, and low-cost disinfection of healthcare materials.

8.
Clin Transplant ; 37(5): e14946, 2023 05.
Article in English | MEDLINE | ID: mdl-36841966

ABSTRACT

BACKGROUND: At the start of 2020, the kidney waiting list consisted of 2526 candidates with a calculated panel reactive antibody (CPRA) of 99.9% or greater, a cohort demonstrated in published research to have meaningfully lower than average access to transplantation even under the revised kidney allocation system (KAS). METHODS: This was a retrospective analysis of US kidney registrations using data from the OPTN [Reference (https://optn.transplant.hrsa.gov/data/about-data/)]. The period-prevalent study cohort consisted of US kidney-alone registrations who waited at least 1 day between April 1, 2016, when HLA DQ-Alpha and DP-Beta unacceptable antigen data became available in OPTN data collection, to December 31, 2019. Poisson rate regression was used to model deceased donor kidney transplant rates per active year waiting and using an offset term to account for differential at-risk periods. Median time to transplant was estimated for each IRR group using the Kaplan-Meier method. Sensitivity analyses were included to address geographic variation in supply-to-demand ratios and differences in dialysis time or waiting time. RESULTS: In this study, we found 1597 additional sensitized (CPRA 50-<99.9%) candidates with meaningfully lower than average access to transplant when simultaneously taking into account CPRA and other factors. In combination with CPRA, candidate blood type, Estimated Post-Transplant Survival Score (EPTS), and presence of other antibody specificities beyond those in the current, 5-locus CPRA were found to influence the likelihood of transplant. CONCLUSION: In total, this suggests approximately 4100 sensitized candidates are on the waiting list who represent a community of disadvantaged patients who may benefit from progressive therapies and interventions to facilitate incompatible transplantation. Though associated with higher risks, such interventions may nevertheless be more attractive than remaining on dialysis with the associated accumulation of mortality risk over time.


Subject(s)
Kidney Failure, Chronic , Kidney Transplantation , Tissue Donors , Tissue and Organ Procurement , Waiting Lists , Humans , Kidney/pathology , Retrospective Studies , Health Services Accessibility , Tissue and Organ Procurement/supply & distribution
9.
Biomedicines ; 10(4)2022 Mar 31.
Article in English | MEDLINE | ID: mdl-35453573

ABSTRACT

Oxidative stress-inducing therapies are characterized as a specific treatment that involves the production of reactive oxygen and nitrogen species (RONS) by external or internal sources. To protect cells against oxidative stress, cells have evolved a strong antioxidant defense system to either prevent RONS formation or scavenge them. The maintenance of the redox balance ensures signal transduction, development, cell proliferation, regulation of the mechanisms of cell death, among others. Oxidative stress can beneficially be used to treat several diseases such as neurodegenerative disorders, heart disease, cancer, and other diseases by regulating the antioxidant system. Understanding the mechanisms of various endogenous antioxidant systems can increase the therapeutic efficacy of oxidative stress-based therapies, leading to clinical success in medical treatment. This review deals with the recent novel findings of various cellular endogenous antioxidant responses behind oxidative stress, highlighting their implication in various human diseases, such as ulcers, skin pathologies, oncology, and viral infections such as SARS-CoV-2.

10.
Int J Mol Sci ; 23(4)2022 Feb 10.
Article in English | MEDLINE | ID: mdl-35216069

ABSTRACT

Pancreatic ductal adenocarcinoma (PDAC) is a challenging neoplastic disease, mainly due to the development of resistance to radio- and chemotherapy. Cold atmospheric plasma (CAP) is an alternative technology that can eliminate cancer cells through oxidative damage, as shown in vitro, in ovo, and in vivo. However, how CAP affects the pancreatic stellate cells (PSCs), key players in the invasion and metastasis of PDAC, is poorly understood. This study aims to determine the effect of an anti-PDAC CAP treatment on PSCs tissue developed in ovo using mono- and co-cultures of RLT-PSC (PSCs) and Mia PaCa-2 cells (PDAC). We measured tissue reduction upon CAP treatment and mRNA expression of PSC activation markers and extracellular matrix (ECM) remodelling factors via qRT-PCR. Protein expression of selected markers was confirmed via immunohistochemistry. CAP inhibited growth in Mia PaCa-2 and co-cultured tissue, but its effectiveness was reduced in the latter, which correlates with reduced ki67 levels. CAP did not alter the mRNA expression of PSC activation and ECM remodelling markers. No changes in MMP2 and MMP9 expression were observed in RLT-PSCs, but small changes were observed in Mia PaCa-2 cells. Our findings support the ability of CAP to eliminate PDAC cells, without altering the PSCs.


Subject(s)
Pancreatic Neoplasms/therapy , Pancreatic Stellate Cells/drug effects , Plasma Gases/pharmacology , Adenocarcinoma/metabolism , Adenocarcinoma/therapy , Animals , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/therapy , Cell Line, Tumor , Cell Movement/drug effects , Cell Proliferation/drug effects , Chickens , Extracellular Matrix/metabolism , Gene Expression Regulation, Neoplastic/drug effects , Humans , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Pancreatic Neoplasms/metabolism , Pancreatic Stellate Cells/metabolism , Phenotype , Tumor Microenvironment/drug effects
11.
J Chem Inf Model ; 62(1): 129-141, 2022 01 10.
Article in English | MEDLINE | ID: mdl-34965734

ABSTRACT

Binding of the SARS-CoV-2 S-glycoprotein to cell receptors is vital for the entry of the virus into cells and subsequent infection. ACE2 is the main cell receptor for SARS-CoV-2, which can attach to the C-terminal receptor-binding domain (RBD) of the SARS-CoV-2 S-glycoprotein. The GRP78 receptor plays an anchoring role, which attaches to the RBD and increases the chance of other RBDs binding to ACE2. Although high levels of reactive oxygen and nitrogen species (RONS) are produced during viral infections, it is not clear how they affect the RBD structure and its binding to ACE2 and GRP78. In this research, we apply molecular dynamics simulations to study the effect of oxidation of the highly reactive cysteine (Cys) amino acids of the RBD on its binding to ACE2 and GRP78. The interaction energy of both ACE2 and GRP78 with the whole RBD, as well as with the RBD main regions, is compared in both the native and oxidized RBDs. Our results show that the interaction energy between the oxidized RBD and ACE2 is strengthened by 155 kJ/mol, increasing the binding of the RBD to ACE2 after oxidation. In addition, the interaction energy between the RBD and GRP78 is slightly increased by 8 kJ/mol after oxidation, but this difference is not significant. Overall, these findings highlight the role of RONS in the binding of the SARS-CoV-2 S-glycoprotein to host cell receptors and suggest an alternative mechanism by which RONS could modulate the entrance of viral particles into the cells.


Subject(s)
Cysteine/chemistry , Spike Glycoprotein, Coronavirus/chemistry , Angiotensin-Converting Enzyme 2/metabolism , COVID-19 , Endoplasmic Reticulum Chaperone BiP/metabolism , Humans , Reactive Nitrogen Species , Reactive Oxygen Species , Receptors, Virus/metabolism , SARS-CoV-2
12.
Am J Transplant ; 22(3): 691-697, 2022 03.
Article in English | MEDLINE | ID: mdl-34467625

ABSTRACT

The IgG-degrading enzyme derived from Streptococcus pyogenes (Imlifidase, Hansa Biopharma) is a novel agent that cleaves all four human subclasses of IgG and has therapeutic potential for HLA desensitization in kidney transplantation and antibody-mediated rejection. Data from clinical trials in kidney transplantation demonstrated rapid degradation of anti-HLA donor-specific antibodies facilitating HLA-incompatible transplantation, which led to conditional approval of imlifidase by the European Medicines Agency for desensitization in kidney transplant recipients of a deceased donor with a positive cross match. Important considerations arising from the early experiences with imilfidase on kinetics of donor-specific antibodies after administration, timing of complementary therapeutic monoclonal or polyclonal IgG antibodies, and interference with cross match assays should be recognized as imlifidase emerges as a therapeutic agent for clinical transplantation.


Subject(s)
Kidney Transplantation , Antilymphocyte Serum , Graft Rejection/etiology , Graft Rejection/prevention & control , HLA Antigens , Humans , Immunoglobulin G , Immunosuppressive Agents , Tissue Donors
13.
J Med Primatol ; 50(6): 306-312, 2021 12.
Article in English | MEDLINE | ID: mdl-34622472

ABSTRACT

BACKGROUND: In captive colonies, owl monkeys' mothers sometimes reject their newborns. To prevent, mortality infants are manually raised by veterinarians. Both parental separation and rejection are stressful experiences, associated with elevated stress, physical, and behavioural disorders. The effect of parental deprivation in IVITA's owl monkeys stress profiles and health is unknown. METHODS: We compared stress biomarkers such as hair cortisol (using cortisol ELISA), stereotypic behaviours (with infrared cameras), and infection histories in juveniles separated from parents soon after birth (n = 14, ~17 months) and controls (n = 11, ~17 months). RESULTS: Parentally deprived owl monkeys show higher infection rates than controls (p = .001). However, they display no higher incidence of biomarkers of stress: Neither stereotypic behaviour nor cortisol in hair was different between cohorts. Irrespective of deprivation status, rates of infection, and concentration of cortisol in hair were positively associated (R2 = .29, p = .005). CONCLUSION: Early parental deprivation and natural high levels of cortisol secretion are associated with elevated infection levels in the IVITA owl monkey juveniles detectable up to 17 months post separation.


Subject(s)
Aotidae , Hydrocortisone , Animals , Biomarkers , Hair
14.
Am J Transplant ; 21(12): 3907-3918, 2021 12.
Article in English | MEDLINE | ID: mdl-34236770

ABSTRACT

Imlifidase is a cysteine proteinase which specifically cleaves IgG, inhibiting Fc-mediated effector function within hours of administration. Imlifidase converts a positive crossmatch to a potential donor (T cell, B cell, or both), to negative, enabling transplantation to occur between previously HLA incompatible donor-recipient pairs. To date, 39 crossmatch positive patients received imlifidase prior to a kidney transplant in four single-arm, open-label, phase 2 studies. At 3 years, for patients who were AMR+ compared to AMR-, death-censored allograft survival was 93% vs 77%, patient survival was 85% vs 94%, and mean eGFR was 49 ml/min/1.73 m2 vs 61 ml/min/1.73 m2 , respectively. The incidence of AMR was 38% with most episodes occurring within the first month post-transplantation. Sub-analysis of patients deemed highly sensitized with cPRA ≥ 99.9%, and unlikely to be transplanted who received crossmatch-positive, deceased donor transplants had similar rates of patient survival, graft survival, and eGFR but a higher rate of AMR. These data demonstrate that outcomes and safety up to 3 years in recipients of imlifidase-enabled allografts is comparable to outcomes in other highly sensitized patients undergoing HLA-incompatible transplantation. Thus, imlifidase is a potent option to facilitate transplantation among patients who have a significant immunologic barrier to successful kidney transplantation. Clinical Trial: ClinicalTrials.gov (NCT02790437), EudraCT Number: 2016-002064-13.


Subject(s)
Kidney Transplantation , Desensitization, Immunologic , Graft Rejection/etiology , Graft Survival , HLA Antigens , Histocompatibility Testing , Humans , Kidney Transplantation/adverse effects
15.
Front Immunol ; 12: 694222, 2021.
Article in English | MEDLINE | ID: mdl-34177958

ABSTRACT

Advances in systems immunology, such as new biomarkers, offer the potential for highly personalized immunosuppression regimens that could improve patient outcomes. In the future, integrating all of this information with other patient history data will likely have to rely on artificial intelligence (AI). AI agents can help augment transplant decision making by discovering patterns and making predictions for specific patients that are not covered in the literature or in ways that are impossible for humans to anticipate by integrating vast amounts of data (e.g. trending across numerous biomarkers). Similar to other clinical decision support systems, AI may help overcome human biases or judgment errors. However, AI is not widely utilized in transplant to date. In this rapid review, we survey the methods employed in recent research in transplant-related AI applications and identify concerns related to implementing these tools. We identify three key challenges (bias/accuracy, clinical decision process/AI explainability, AI acceptability criteria) holding back AI in transplant. We also identify steps that can be taken in the near term to help advance meaningful use of AI in transplant (forming a Transplant AI Team at each center, establishing clinical and ethical acceptability criteria, and incorporating AI into the Shared Decision Making Model).


Subject(s)
Artificial Intelligence , Decision Support Techniques , Organ Transplantation , Patient Care Team , Therapy, Computer-Assisted , Clinical Decision-Making , Data Mining , Humans , Meaningful Use , Organ Transplantation/adverse effects , Pattern Recognition, Automated , Reproducibility of Results
16.
Int J Biol Macromol ; 182: 1724-1736, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-34051258

ABSTRACT

Bacterial and mammalian proteins, such as lysozyme, are gaining increasing interest as anticancer drugs. This study aims to modify the lysozyme structure using cold atmospheric plasma to boost its cancer cell killing effect. We investigated the structure at acidic and neutral pH using various experimental techniques (circular dichroism, fluorescence, and mass spectrometry) and molecular dynamics simulations. The controlled structural modification of lysozyme at neutral pH enhances its activity, while the activity was lost at acidic pH at the same treatment conditions. Indeed, a larger number of amino acids were oxidized at acidic pH after plasma treatment, which results in a greater distortion of the lysozyme structure, whereas only limited structural changes were observed in lysozyme after plasma treatment at neutral pH. We found that the plasma-treated lysozyme significantly induced apoptosis to the cancer cells. Our results reveal that plasma-treated lysozyme could have potential as a new cancer cell killing drug.


Subject(s)
Muramidase/chemistry , Plasma Gases/pharmacology , Apoptosis/drug effects , Cell Death/drug effects , Cell Line, Tumor , Cell Survival/drug effects , Humans , Hydrogen-Ion Concentration , Mass Spectrometry , Molecular Dynamics Simulation , Oxidation-Reduction , Peptides/chemistry , Protein Conformation , Spectrometry, Fluorescence , Transition Temperature , Tryptophan/metabolism
17.
Redox Biol ; 43: 101968, 2021 07.
Article in English | MEDLINE | ID: mdl-33895486

ABSTRACT

Multiple cancer therapies nowadays rely on oxidative stress to damage cancer cells. Here we investigated the biological and molecular effect of oxidative stress on the interaction between CD44 and hyaluronan (HA), as interrupting their binding can hinder cancer progression. Our experiments demonstrated that the oxidation of HA decreased its recognition by CD44, which was further enhanced when both CD44 and HA were oxidized. The reduction of CD44-HA binding negatively affected the proliferative state of cancer cells. Our multi-level atomistic simulations revealed that the binding free energy of HA to CD44 decreased upon oxidation. The effect of HA and CD44 oxidation on CD44-HA binding was similar, but when both HA and CD44 were oxidized, the effect was much larger, in agreement with our experiments. Hence, our experiments and computations support our hypothesis on the role of oxidation in the disturbance of CD44-HA interaction, which can lead to the inhibition of proliferative signaling pathways inside the tumor cell to induce cell death.


Subject(s)
Hyaluronic Acid , Neoplasms , Hyaluronan Receptors , Oxidative Stress , Signal Transduction
18.
Cancers (Basel) ; 13(8)2021 Apr 08.
Article in English | MEDLINE | ID: mdl-33917880

ABSTRACT

Glioblastoma multiforme (GBM) is the most frequent and aggressive primary malignant brain tumor in adults. Current standard radiotherapy and adjuvant chemotherapy with the alkylating agent temozolomide (TMZ) yield poor clinical outcome. This is due to the stem-like properties of tumor cells and genetic abnormalities in GBM, which contribute to resistance to TMZ and progression. In this study, we used cold atmospheric plasma (CAP) to enhance the sensitivity to TMZ through inhibition of antioxidant signaling (linked to TMZ resistance). We demonstrate that CAP indeed enhances the cytotoxicity of TMZ by targeting the antioxidant specific glutathione (GSH)/glutathione peroxidase 4 (GPX4) signaling. We optimized the threshold concentration of TMZ on five different GBM cell lines (U251, LN18, LN229, U87-MG and T98G). We combined TMZ with CAP and tested it on both TMZ-sensitive (U251, LN18 and LN229) and TMZ-resistant (U87-MG and T98G) cell lines using two-dimensional cell cultures. Subsequently, we used a three-dimensional spheroid model for the U251 (TMZ-sensitive) and U87-MG and T98G (TMZ-resistant) cells. The sensitivity of TMZ was enhanced, i.e., higher cytotoxicity and spheroid shrinkage was obtained when TMZ and CAP were administered together. We attribute the anticancer properties to the release of intracellular reactive oxygen species, through inhibiting the GSH/GPX4 antioxidant machinery, which can lead to DNA damage. Overall, our findings suggest that the combination of CAP with TMZ is a promising combination therapy to enhance the efficacy of TMZ towards the treatment of GBM spheroids.

19.
Cancers (Basel) ; 13(3)2021 Feb 02.
Article in English | MEDLINE | ID: mdl-33540720

ABSTRACT

Non-thermal plasma (NTP) therapy has been emerging as a promising cancer treatment strategy, and recently, its ability to locally induce immunogenic cancer cell death is being unraveled. We hypothesized that the chemical species produced by NTP reduce immunosuppressive surface proteins and checkpoints that are overexpressed on cancerous cells. Here, 3D in vitro tumor models, an in vivo mouse model, and molecular dynamics simulations are used to investigate the effect of NTP on CD47, a key innate immune checkpoint. CD47 is immediately modulated after NTP treatment and simulations reveal the potential oxidized salt-bridges responsible for conformational changes. Umbrella sampling simulations of CD47 with its receptor, signal-regulatory protein alpha (SIRPα), demonstrate that the induced-conformational changes reduce its binding affinity. Taken together, this work provides new insight into fundamental, chemical NTP-cancer cell interaction mechanisms and a previously overlooked advantage of present NTP cancer therapy: reducing immunosuppressive signals on the surface of cancer cells.

20.
Free Radic Biol Med ; 166: 187-200, 2021 04.
Article in English | MEDLINE | ID: mdl-33636332

ABSTRACT

Despite modern therapeutic advances, the survival prospects of pancreatic cancer patients remain poor, due to chemoresistance and dysregulated oncogenic kinase signaling networks. We applied a novel kinome activity-mapping approach using biological peptide targets as phospho-sensors to identify vulnerable kinase dependencies for therapy sensitization by physical plasma. Ser/Thr-kinome specific activity changes were mapped upon induction of ferroptotic cell death in pancreatic tumor cells exposed to reactive oxygen and nitrogen species of plasma-treated water (PTW). This revealed a broad kinome activity response involving the CAMK, the AGC and CMGC family of kinases. This systems-level kinome network response supports stress adaptive switches between chemoresistant anti-oxidant responses of Kelch-like ECH-associated protein 1 (KEAP1)/Heme Oxygenase 1 (HMOX1) and ferroptotic cell death sensitization upon suppression of Nuclear factor (erythroid derived 2)-like 2 (NRF2) and Glutathione peroxidase 4 (GPX4). This is further supported by ex vivo experiments in the chicken chorioallantoic membrane assay, showing decreased GPX4 and Glutathione (GSH) expression as well as increased lipid peroxidation, along with suppressed BxPC-3 tumor growth in response to PTW. Taken all together, we demonstrate that plasma treated water-derived oxidants sensitize pancreatic cancer cells to ferroptotic cell death by targeting a NRF2-HMOX1-GPX4 specific kinase signaling network.


Subject(s)
NF-E2-Related Factor 2 , Pancreatic Neoplasms , Cell Death , Humans , Kelch-Like ECH-Associated Protein 1/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Oxidants , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics , Reactive Oxygen Species/metabolism
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