scholarly journals Adaptation to Chronic-Cycling Hypoxia Renders Cancer Cells Resistant to MTH1-Inhibitor Treatment Which Can Be Counteracted by Glutathione Depletion

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3040
Author(s):  
Christine Hansel ◽  
Julian Hlouschek ◽  
Kexu Xiang ◽  
Margarita Melnikova ◽  
Juergen Thomale ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Cancer Cells ◽  
Redox Homeostasis ◽  
Acquired Resistance ◽  
Tumor Hypoxia ◽  
Resistance Mechanism ◽  
Glutathione Depletion ◽  
Treatment Conditions ◽  
Increased Radioresistance ◽  
Hypoxia Reoxygenation

Tumor hypoxia and hypoxic adaptation of cancer cells represent major barriers to successful cancer treatment. We revealed that improved antioxidant capacity contributes to increased radioresistance of cancer cells with tolerance to chronic-cycling severe hypoxia/reoxygenation stress. We hypothesized, that the improved tolerance to oxidative stress will increase the ability of cancer cells to cope with ROS-induced damage to free deoxy-nucleotides (dNTPs) required for DNA replication and may thus contribute to acquired resistance of cancer cells in advanced tumors to antineoplastic agents inhibiting the nucleotide-sanitizing enzyme MutT Homologue-1 (MTH1), ionizing radiation (IR) or both. Therefore, we aimed to explore potential differences in the sensitivity of cancer cells exposed to acute and chronic-cycling hypoxia/reoxygenation stress to the clinically relevant MTH1-inhibitor TH1579 (Karonudib) and to test whether a multi-targeting approach combining the glutathione withdrawer piperlongumine (PLN) and TH1579 may be suited to increase cancer cell sensitivity to TH1579 alone and in combination with IR. Combination of TH1579 treatment with radiotherapy (RT) led to radiosensitization but was not able to counteract increased radioresistance induced by adaptation to chronic-cycling hypoxia/reoxygenation stress. Disruption of redox homeostasis using PLN sensitized anoxia-tolerant cancer cells to MTH1 inhibition by TH1579 under both normoxic and acute hypoxic treatment conditions. Thus, we uncover a glutathione-driven compensatory resistance mechanism towards MTH1-inhibition in form of increased antioxidant capacity as a consequence of microenvironmental or therapeutic stress.

scholarly journals Forcing dividing cancer cells to die; low‐dose drug combinations to prevent spindle pole clustering

APOPTOSIS ◽  
2021 ◽  
Author(s):  
Eloise Ducrey ◽  
Cédric Castrogiovanni ◽  
Patrick Meraldi ◽  
Patrycja Nowak-Sliwinska
Keyword(s):  
Cancer Cells ◽  
Single Molecule ◽  
Mitotic Spindle ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Spindle Pole ◽  
Cancer Treatments ◽  
Mitotic Kinases ◽  
Microtubule Targeting Agents

AbstractMitosis, under the control of the microtubule-based mitotic spindle, is an attractive target for anti-cancer treatments, as cancer cells undergo frequent and uncontrolled cell divisions. Microtubule targeting agents that disrupt mitosis or single molecule inhibitors of mitotic kinases or microtubule motors kill cancer cells with a high efficacy. These treatments have, nevertheless, severe disadvantages: they also target frequently dividing healthy tissues, such as the haematopoietic system, and they often lose their efficacy due to primary or acquired resistance mechanisms. An alternative target that has emerged in dividing cancer cells is their ability to “cluster” the poles of the mitotic spindle into a bipolar configuration. This mechanism is necessary for the specific survival of cancer cells that tend to form multipolar spindles due to the frequent presence of abnormal centrosome numbers or other spindle defects. Here we discuss the recent development of combinatorial treatments targeting spindle pole clustering that specifically target cancer cells bearing aberrant centrosome numbers and that have the potential to avoid resistance mechanism due their combinatorial nature.

scholarly journals Reaction of carbon monoxide with cystathionine β-synthase: implications on drug efficacies in cancer chemotherapy

2020 ◽  
Vol 12 (4) ◽  
pp. 325-337
Author(s):  
Brian Kawahara ◽  
Suvajit Sen ◽  
Pradip K Mascharak
Keyword(s):  
Reactive Oxygen Species ◽  
Carbon Monoxide ◽  
Drug Resistance ◽  
Cancer Therapy ◽  
Antioxidant Capacity ◽  
Cancer Cells ◽  
Redox Homeostasis ◽  
Drug Effects ◽  
Oxygen Species ◽  
Treatment Regimens

Photo-activatable carbon monoxide (CO)-releasing molecules (photoCORMs), have recently provided help to identify the salutary effects of CO in human pathophysiology. Among them notable is the ability of CO to sensitize chemotherapeutic-resistant cancer cells. Findings from our group have shown CO to mitigate drug resistance in certain cancer cells by the inhibition of cystathionine β-synthase (CBS), a key regulator of redox homeostasis in the cell. Diminution of the antioxidant capacity of cancer cells leads to sensitization to reactive oxygen species-producing drugs like doxorubicin and paclitaxel upon cotreatment with CO as well as in mitigating the drug effects of cisplatin. We hypothesize that the development of CO delivery techniques for coadministration with existing cancer treatment regimens may ultimately improve clinical outcomes in cancer therapy.

scholarly journals Oxidative Stress in the Tumor Microenvironment and Its Relevance to Cancer Immunotherapy

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 986
Author(s):  
Nada S. Aboelella ◽  
Caitlin Brandle ◽  
Timothy Kim ◽  
Zhi-Chun Ding ◽  
Gang Zhou
Keyword(s):  
Oxidative Stress ◽  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Redox Homeostasis ◽  
Tumor Rejection ◽  
Oxygen Species ◽  
Antitumor Effects ◽  
Key Drivers ◽  
Cancer Immunotherapies ◽  
The Impact

It has been well-established that cancer cells are under constant oxidative stress, as reflected by elevated basal level of reactive oxygen species (ROS), due to increased metabolism driven by aberrant cell growth. Cancer cells can adapt to maintain redox homeostasis through a variety of mechanisms. The prevalent perception about ROS is that they are one of the key drivers promoting tumor initiation, progression, metastasis, and drug resistance. Based on this notion, numerous antioxidants that aim to mitigate tumor oxidative stress have been tested for cancer prevention or treatment, although the effectiveness of this strategy has yet to be established. In recent years, it has been increasingly appreciated that ROS have a complex, multifaceted role in the tumor microenvironment (TME), and that tumor redox can be targeted to amplify oxidative stress inside the tumor to cause tumor destruction. Accumulating evidence indicates that cancer immunotherapies can alter tumor redox to intensify tumor oxidative stress, resulting in ROS-dependent tumor rejection. Herein we review the recent progresses regarding the impact of ROS on cancer cells and various immune cells in the TME, and discuss the emerging ROS-modulating strategies that can be used in combination with cancer immunotherapies to achieve enhanced antitumor effects.

Acrylamide-encapsulated glucose oxidase inhibits breast cancer cell viability

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Trëndelina Rrustemi ◽  
Öykü Gönül Geyik ◽  
Ali Burak Özkaya ◽  
Taylan Kurtuluş Öztürk ◽  
Zeynep Yüce ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Oxidase ◽  
Cancer Cells ◽  
Half Life ◽  
Neutralizing Antibodies ◽  
Redox Homeostasis ◽  
Proteinase K ◽  
Dependent Manner ◽  
Production Of Hydrogen ◽  
Mcf 7

AbstractObjectivesCancer cells modulate metabolic pathways to ensure continuity of energy, macromolecules and redox- homeostasis. Although these vulnerabilities are often targeted individually, targeting all with an enzyme may prove a novel approach. However, therapeutic enzymes are prone to proteolytic degradation and neutralizing antibodies leading to a reduced half-life and effectiveness. We hypothesized that glucose oxidase (GOX) enzyme that catalyzes oxidation of glucose and production of hydrogen peroxide, may hit all these targets by depleting glucose; crippling anabolic pathways and producing reactive oxygen species (ROS); unbalancing redox homeostasis.MethodsWe encapsulated GOX in an acrylamide layer and then performed activity assays in denaturizing settings to determine protection provided by encapsulation. Afterwards, we tested the effects of encapsulated (enGOX) and free (fGOX) enzyme on MCF-7 breast cancer cells.ResultsGOX preserved 70% of its activity following encapsulation. When fGOX and enGOX treated with guanidinium chloride, fGOX lost approximately 72% of its activity, while enGOX only lost 30%. Both forms demonstrated remarkable resilience against degradation by proteinase K and inhibited viability of MCF-7 cells in an activity-dependent manner.ConclusionsEncapsulation provided protection to GOX against denaturation without reducing its activity, which would prolong half-life of the enzyme when administered intravenously.

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