EXTH-06. ATR INHIBITORS AS MONOTHERAPY AND COMBINATORIAL THERAPY WITH TEMOZOLOMIDE IN PRECLINICAL GLIOBLASTOMA MODELS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi164-vi164
Author(s):  
Dimpy Koul ◽  
Xiaolong Li ◽  
Shaofang Wu ◽  
Sanjay Kumar singh ◽  
Kadir Caner Akdemir ◽  
...  
Keyword(s):  
Dna Damage ◽  
Combination Treatment ◽  
Cellular Response ◽  
Methylation Status ◽  
Standard Of Care ◽  
The Body ◽  
Treatment Modalities ◽  
Multiple Treatment ◽  
Sensitivity Pattern ◽  
Selective Sensitivity

Abstract Glioblastoma (GBM) is an aggressive brain tumor and has an extremely poor prognosis despite the use of multiple treatment modalities. DNA damage response (DDR) signaling plays an important role in inducing radiation and temozolomide (TMZ) resistance and hence has emerged as a molecular target for therapeutic development. The Ataxia Telangiectasia and Rad3-related protein (ATR) kinase is a key regulator of the DDR machinery, activated by DNA damage. Here, we show that three clinical-grade ATR inhibitors (Bay1895344, AZD6738 and Berzosertib) had similar selective sensitivity pattern across 16 glioma-like stem cell (GSC) lines tested. ATR inhibitors inhibited the growth of GSCs at low nanomolar range concentrations. Interestingly, all three ATR inhibitors showed a significant synergism with TMZ in a selective group of GSCs (Combination index and Bliss model). Importantly, we demonstrate that MGMT promoter methylation status was associated with cellular response to combination treatment with preferential inhibition of cell growth in MGMT promotor methylated (MGMT deficient) cell lines. Further, we compared the RNA-seq data from GSCs in the synergism and non-synergism group and used multiple complementary approaches to identify the response marker that confer sensitivity to combination therapy. Our preliminary data analysis identified several genes that confer sensitivity to combination treatment and studies are underway to validate the data. We also investigated the efficacy of BBB penetrant ATR inhibitor BAY 1895344 in orthotropic xenografts and administration of BAY 1895344 and TMZ combination significantly reduced tumor size and extended survival in an intracranial animal model. Combining ATR inhibitor with TMZ was well tolerated and did not confer additional toxicity as the body weights of TMZ and combination groups were comparable. The findings from this study provides a rationale to use ATR inhibitors in combination with TMZ in MGMT methylated tumors to improve therapeutic efficacy of standard of care for GBM patients.

scholarly journals Regular, Intense Exercise Training as a Healthy Aging Lifestyle Strategy: Preventing DNA Damage, Telomere Shortening and Adverse DNA Methylation Changes Over a Lifetime

2021 ◽  
Vol 12 ◽  
Author(s):  
Maha Sellami ◽  
Nicola Bragazzi ◽  
Mohammad Shoaib Prince ◽  
Joshua Denham ◽  
Mohamed Elrayess
Keyword(s):  
Dna Methylation ◽  
Dna Damage ◽  
Exercise Training ◽  
Epigenetic Modification ◽  
Methylation Status ◽  
The Body ◽  
Training Load ◽  
Activity Level ◽  
Biological Aging ◽  
Age Related

Exercise training is one of the few therapeutic interventions that improves health span by delaying the onset of age-related diseases and preventing early death. The length of telomeres, the 5′-TTAGGGn-3′ tandem repeats at the ends of mammalian chromosomes, is one of the main indicators of biological age. Telomeres undergo shortening with each cellular division. This subsequently leads to alterations in the expression of several genes that encode vital proteins with critical functions in many tissues throughout the body, and ultimately impacts cardiovascular, immune and muscle physiology. The sub-telomeric DNA is comprised of heavily methylated, heterochromatin. Methylation and histone acetylation are two of the most well-studied examples of the epigenetic modifications that occur on histone proteins. DNA methylation is the type of epigenetic modification that alters gene expression without modifying gene sequence. Although diet, genetic predisposition and a healthy lifestyle seem to alter DNA methylation and telomere length (TL), recent evidence suggests that training status or physical fitness are some of the major factors that control DNA structural modifications. In fact, TL is positively associated with cardiorespiratory fitness, physical activity level (sedentary, active, moderately trained, or elite) and training intensity, but is shorter in over-trained athletes. Similarly, somatic cells are vulnerable to exercise-induced epigenetic modification, including DNA methylation. Exercise-training load, however, depends on intensity and volume (duration and frequency). Training load-dependent responses in genomic profiles could underpin the discordant physiological and physical responses to exercise. In the current review, we will discuss the role of various forms of exercise training in the regulation of DNA damage, TL and DNA methylation status in humans, to provide an update on the influence exercise training has on biological aging.

scholarly journals Cytokine Storm as a Cellular Response to dsDNA Breaks: A New Proposal

2021 ◽  
Vol 12 ◽  
Author(s):  
Snehal Shabrish ◽  
Indraneel Mittra
Keyword(s):  
Dna Damage ◽  
Cellular Response ◽  
The Body ◽  
Host Cells ◽  
Preclinical Studies ◽  
Cytokine Storm ◽  
Vicious Cycle ◽  
Cascading Effect ◽  
Microbial Invasion ◽  
Cellular Dna

Pathogenesis of cytokine storm is poorly understood. In this article we propose a new mechanism and suggest innovative therapeutic avenues for its prevention. We have reported that particles of cell-free chromatin (cfCh) that are released from the billions of cells that die in the body everyday can illegitimately integrate into genomes of healthy cells to trigger dsDNA breaks. The latter leads to apoptosis and/or intense activation of inflammatory cytokines in the affected cells. We hypothesise that a similar phenomenon of dsDNA breaks and inflammation is involved in cytokine storm. The abundant cfCh particles that are released from dying host cells following viral/microbial invasion initiate a cascading effect of more cell death resulting in a vicious cycle of further DNA damage, apoptosis and hyper-inflammation which culminate in cytokine storm. We propose that this unrelenting vicious cycle of cellular DNA damage and cytokine storm may be the underlying cause of high mortality from severe COVID-19. We discuss results of our preclinical studies wherein we have shown that endotoxin induced cytokine storm in mice can be reversed by three different agents that have the ability to inactivate cfCh. These agents may be worthy of investigation in clinical trials to reduce mortality from COVID-19.

Biocompatible Nanovesicular Drug Delivery Systems with Targeting Potential for Autoimmune Diseases

2020 ◽  
Vol 26 (42) ◽  
pp. 5488-5502 ◽  
Author(s):  
Yub Raj Neupane ◽  
Asiya Mahtab ◽  
Lubna Siddiqui ◽  
Archu Singh ◽  
Namrata Gautam ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Autoimmune Diseases ◽  
Lupus Erythematosus ◽  
Drug Delivery Systems ◽  
Drug Carriers ◽  
Immunological Tolerance ◽  
Delivery Systems ◽  
The Body ◽  
Autoimmune Response ◽  
Treatment Modalities

Autoimmune diseases are collectively addressed as chronic conditions initiated by the loss of one’s immunological tolerance, where the body treats its own cells as foreigners or self-antigens. These hay-wired antibodies or immunologically capable cells lead to a variety of disorders like rheumatoid arthritis, psoriatic arthritis, systemic lupus erythematosus, multiple sclerosis and recently included neurodegenerative diseases like Alzheimer’s, Parkinsonism and testicular cancer triggered T-cells induced autoimmune response in testes and brain. Conventional treatments for autoimmune diseases possess several downsides due to unfavourable pharmacokinetic behaviour of drug, reflected by low bioavailability, rapid clearance, offsite toxicity, restricted targeting ability and poor therapeutic outcomes. Novel nanovesicular drug delivery systems including liposomes, niosomes, proniosomes, ethosomes, transferosomes, pharmacosomes, ufasomes and biologically originated exosomes have proved to possess alluring prospects in supporting the combat against autoimmune diseases. These nanovesicles have revitalized available treatment modalities as they are biocompatible, biodegradable, less immunogenic and capable of carrying high drug payloads to deliver both hydrophilic as well as lipophilic drugs to specific sites via passive or active targeting. Due to their unique surface chemistry, they can be decorated with physiological or synthetic ligands to target specific receptors overexpressed in different autoimmune diseases and can even cross the blood-brain barrier. This review presents exhaustive yet concise information on the potential of various nanovesicular systems as drug carriers in improving the overall therapeutic efficiency of the dosage regimen for various autoimmune diseases. The role of endogenous exosomes as biomarkers in the diagnosis and prognosis of autoimmune diseases along with monitoring progress of treatment will also be highlighted.

Herbal Medicine for Glioblastoma: Current and Future Prospects

2020 ◽  
Vol 16 (8) ◽  
pp. 1022-1043
Author(s):  
Imran Khan ◽  
Sadaf Mahfooz ◽  
Mustafa A. Hatiboglu
Keyword(s):  
Cell Proliferation ◽  
Survival Rates ◽  
Standard Of Care ◽  
Natural Compounds ◽  
Treatment Modalities ◽  
Normal Brain ◽  
The Central Nervous System ◽  
Cycle Regulation ◽  
Immense Potential

Background: Glioblastoma is one of the most aggressive and devastating tumours of the central nervous system with short survival time. Glioblastoma usually shows fast cell proliferation and invasion of normal brain tissue causing poor prognosis. The present standard of care in patients with glioblastoma includes surgery followed by radiotherapy and temozolomide (TMZ) based chemotherapy. Unfortunately, these approaches are not sufficient to lead a favorable prognosis and survival rates. As the current approaches do not provide a long-term benefit in those patients, new alternative treatments including natural compounds, have drawn attention. Due to their natural origin, they are associated with minimum cellular toxicity towards normal cells and it has become one of the most attractive approaches to treat tumours by natural compounds or phytochemicals. Objective: In the present review, the role of natural compounds or phytochemicals in the treatment of glioblastoma describing their efficacy on various aspects of glioblastoma pathophysiology such as cell proliferation, apoptosis, cell cycle regulation, cellular signaling pathways, chemoresistance and their role in combinatorial therapeutic approaches was described. Methods: Peer-reviewed literature was extracted using Pubmed, EMBASE Ovid and Google Scholar to be reviewed in the present article. Conclusion: Preclinical data available in the literature suggest that phytochemicals hold immense potential to be translated into treatment modalities. However, further clinical studies with conclusive results are required to implement phytochemicals in treatment modalities.

scholarly journals CX-5461 Enhances the Efficacy of APR-246 via Induction of DNA Damage and Replication Stress in Triple-Negative Breast Cancer

2021 ◽  
Vol 22 (11) ◽  
pp. 5782
Author(s):  
Ashwini Makhale ◽  
Devathri Nanayakkara ◽  
Prahlad Raninga ◽  
Kum Kum Khanna ◽  
Murugan Kalimutho
Keyword(s):  
Breast Cancer ◽  
Dna Damage ◽  
Triple Negative Breast Cancer ◽  
Combination Treatment ◽  
Triple Negative ◽  
Annexin V ◽  
Replication Stress ◽  
Breast Cancer Cell Lines ◽  
Combination Strategy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer lacking targeted therapy. Here, we evaluated the anti-cancer activity of APR-246, a P53 activator, and CX-5461, a RNA polymerase I inhibitor, in the treatment of TNBC cells. We tested the efficacy of individual and combination therapy of CX-5461 and APR-246 in vitro, using a panel of breast cancer cell lines. Using publicly available breast cancer datasets, we found that components of RNA Pol I are predominately upregulated in basal-like breast cancer, compared to other subtypes, and this upregulation is associated with poor overall and relapse-free survival. Notably, we found that the treatment of breast cancer cells lines with CX-5461 significantly hampered cell proliferation and synergistically enhanced the efficacy of APR-246. The combination treatment significantly induced apoptosis that is associated with cleaved PARP and Caspase 3 along with Annexin V positivity. Likewise, we also found that combination treatment significantly induced DNA damage and replication stress in these cells. Our data provide a novel combination strategy by utilizing APR-246 in combination CX-5461 in killing TNBC cells that can be further developed into more effective therapy in TNBC therapeutic armamentarium.

scholarly journals Update on the role of pembrolizumab in patients with unresectable or metastatic colorectal cancer

2021 ◽  
Vol 14 ◽  
pp. 175628482110244
Author(s):  
Vanessa Wookey ◽  
Axel Grothey
Keyword(s):  
Colorectal Cancer ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Treatment Options ◽  
Standard Of Care ◽  
Cancer Type ◽  
Cancer Therapies ◽  
Multiple Cancer ◽  
Multiple Treatment

Colorectal cancer (CRC) is the third most common cancer type in both men and women in the USA. Most patients with CRC are diagnosed as local or regional disease. However, the survival rate for those diagnosed with metastatic disease remains disappointing, despite multiple treatment options. Cancer therapies for patients with unresectable or metastatic CRC are increasingly being driven by particular biomarkers. The development of various immune checkpoint inhibitors has revolutionized cancer therapy over the last decade by harnessing the immune system in the treatment of cancer, and the role of immunotherapy continues to expand and evolve. Pembrolizumab is an anti-programmed cell death protein 1 immune checkpoint inhibitor and has become an essential part of the standard of care in the treatment regimens for multiple cancer types. This paper reviews the increasing evidence supporting and defining the role of pembrolizumab in the treatment of patients with unresectable or metastatic CRC.

scholarly journals In Vivo and In Vitro Assays Evaluating the Biological Activity of Taurine, Glucose and Energetic Beverages

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2198
Author(s):  
Marcos Mateo-Fernández ◽  
Fernando Valenzuela-Gómez ◽  
Rafael Font ◽  
Mercedes Del Río-Celestino ◽  
Tania Merinas-Amo ◽  
...  
Keyword(s):  
Dna Damage ◽  
Drosophila Melanogaster ◽  
Biological Activity ◽  
Biological Effects ◽  
Methylation Status ◽  
Repetitive Sequences ◽  
Energy Drinks ◽  
Red Bull

Taurine is one of the main ingredients used in energy drinks which are highly consumed in adolescents for their sugary taste and stimulating effect. With energy drinks becoming a worldwide phenomenon, the biological effects of these beverages must be evaluated in order to fully comprehend the potential impact of these products on the health due to the fact nutrition is closely related to science since the population consumes food to prevent certain diseases. Therefore, the aim of this study was to evaluate the biological effects of taurine, glucose, classic Red Bull® and sugar-free Red Bull® in order to check the food safety and the nutraceutical potential of these compounds, characterising different endpoints: (i) Toxicology, antitoxicology, genotoxicology and life expectancy assays were performed in the Drosophila melanogaster model organism; (ii) The in vitro chemopreventive activity of testing compounds was determined by assessing their cytotoxicity, the proapoptotic DNA-damage capability to induce internucleosomal fragmentation, the strand breaks activity and the modulator role on the methylation status of genomic repetitive sequences of HL-60 promyelocytic cells. Whereas none tested compounds showed toxic or genotoxic effect, all tested compounds exerted antitoxic and antigenotoxic activity in Drosophila. Glucose, classic Red Bull® and sugar-free Red Bull® were cytotoxic in HL-60 cell line. Classic Red Bull® induced DNA internucleosomal fragmentation although none of them exhibited DNA damage on human leukaemia cells. In conclusion, the tested compounds are safe on Drosophila melanogaster and classic Red Bull® could overall possess nutraceutical potential in the in vivo and in vitro model used in this study. Besides, taurine could holistically be one of the bioactive compounds responsible for the biological activity of classic Red Bull®.

Regulation of Septum Formation in Aspergillus nidulans by a DNA Damage Checkpoint Pathway

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1055-1067
Author(s):  
Steven D Harris ◽  
Peter R Kraus
Keyword(s):  
Dna Damage ◽  
Aspergillus Nidulans ◽  
Cellular Response ◽  
Dna Damage Checkpoint ◽  
Temperature Sensitive ◽  
Dna Metabolism ◽  
Chromosomal Dna ◽  
Checkpoint Response ◽  
Septum Formation ◽  
Checkpoint Pathway

Abstract In Aspergillus nidulans, germinating conidia undergo multiple rounds of nuclear division before the formation of the first septum. Previous characterization of temperature-sensitive sepB and sepJ mutations showed that although they block septation, they also cause moderate defects in chromosomal DNA metabolism. Results presented here demonstrate that a variety of other perturbations of chromosomal DNA metabolism also delay septum formation, suggesting that this is a general cellular response to the presence of sublethal DNA damage. Genetic evidence is provided that suggests that high levels of cyclin-dependent kinase (cdk) activity are required for septation in A. nidulans. Consistent with this notion, the inhibition of septum formation triggered by defects in chromosomal DNA metabolism depends upon Tyr-15 phosphorylation of the mitotic cdk p34nimX. Moreover, this response also requires elements of the DNA damage checkpoint pathway. A model is proposed that suggests that the DNA damage checkpoint response represents one of multiple sensory inputs that modulates p34nimX activity to control the timing of septum formation.

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