Enterococcal Infections and Drug Resistance Mechanisms

2020 ◽  
pp. 131-158
Author(s):  
Muthu Vijaya Sarathy ◽  
Sivaraman Balaji ◽  
Tingirikari Jagan Mohan Rao
Keyword(s):  
Drug Resistance ◽  
Resistance Mechanisms ◽  
Enterococcal Infections

Clinical applications of circulating tumor DNA in monitoring breast cancer drug resistance

2020 ◽  
Vol 16 (34) ◽  
pp. 2863-2878
Author(s):  
Yang Liu ◽  
Qian Du ◽  
Dan Sun ◽  
Ruiying Han ◽  
Mengmeng Teng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Drug Resistance ◽  
Digital Pcr ◽  
Circulating Tumor Dna ◽  
Resistance Mechanisms ◽  
Clinical Applications ◽  
Current Status ◽  
Cancer Drug ◽  
Genomic Alteration ◽  
Tumor Dna

Breast cancer is one of the leading causes of cancer-related deaths in women worldwide. Unfortunately, treatments often fail because of the development of drug resistance, the underlying mechanisms of which remain unclear. Circulating tumor DNA (ctDNA) is free DNA released into the blood by necrosis, apoptosis or direct secretion by tumor cells. In contrast to repeated, highly invasive tumor biopsies, ctDNA reflects all molecular alterations of tumors dynamically and captures both spatial and temporal tumor heterogeneity. Highly sensitive technologies, including personalized digital PCR and deep sequencing, make it possible to monitor response to therapies, predict drug resistance and tailor treatment regimens by identifying the genomic alteration profile of ctDNA, thereby achieving precision medicine. This review focuses on the current status of ctDNA biology, the technologies used to detect ctDNA and the potential clinical applications of identifying drug resistance mechanisms by detecting tumor-specific genomic alterations in breast cancer.

Dissecting the landscape of CAF-mediated drug resistance mechanisms in ALK-rearranged NSCLC

2020 ◽  
Vol 138 ◽  
pp. S48
Author(s):  
Q. Hu ◽  
L.L. Remsing Rix ◽  
X. Li ◽  
E.A. Welsh ◽  
B. Fang ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Resistance Mechanisms

scholarly journals Cyclodextrin-Based Hybrid Polymeric Complex to Overcome Dual Drug Resistance Mechanisms for Cancer Therapy

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1254
Author(s):  
Lingjie Ke ◽  
Zhiguo Li ◽  
Xiaoshan Fan ◽  
Xian Jun Loh ◽  
Hongwei Cheng ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Gene Delivery ◽  
Cell Membrane ◽  
Inclusion Complex ◽  
Polymeric Micelles ◽  
Drug Loading ◽  
Resistance Mechanisms ◽  
Polymeric Complex ◽  
Cavity Structure ◽  
Dual Drug

Drug resistance always reduces the efficacy of chemotherapy, and the classical mechanisms of drug resistance include drug pump efflux and anti-apoptosis mediators-mediated non-pump resistance. In addition, the amphiphilic polymeric micelles with good biocompatibility and high stability have been proven to deliver the drug molecules inside the cavity into the cell membrane regardless of the efflux of the cell membrane pump. We designed a cyclodextrin (CD)-based polymeric complex to deliver chemotherapeutic doxorubicin (DOX) and Nur77ΔDBD gene for combating pumps and non-pump resistance simultaneously. The natural cavity structure of the polymeric complex, which was comprised with β-cyclodextrin-graft-(poly(ε-caprolactone)-adamantly (β-CD-PCL-AD) and β-cyclodextrin-graft-(poly(ε-caprolactone)-poly(2-(dimethylamino) ethyl methacrylate) (β-CD-PCL-PDMAEMA), can achieve the efficient drug loading and delivery to overcome pump drug resistance. The excellent Nur77ΔDBD gene delivery can reverse Bcl-2 from the tumor protector to killer for inhibiting non-pump resistance. The presence of terminal adamantyl (AD) could insert into the cavity of β-CD-PCL-PDMAEMA via host-guest interaction, and the releasing rate of polymeric inclusion complex was higher than that of the individual β-CD-PCL-PDMAEMA. The polymeric inclusion complex can efficiently deliver the Nur77ΔDBD gene than polyethylenimine (PEI-25k), which is a golden standard for nonviral vector gene delivery. The higher transfection efficacy, rapid DOX cellular uptake, and significant synergetic tumor cell viability inhibition were achieved in a pump and non-pump drug resistance cell model. The combined strategy with dual drug resistance mechanisms holds great potential to combat drug-resistant cancer.

scholarly journals Mechanisms of Drug Resistance in the Pathogenesis of Epilepsy: Role of Neuroinflammation. A Literature Review

2021 ◽  
Vol 11 (5) ◽  
pp. 663
Author(s):  
Elena D. Bazhanova ◽  
Alexander A. Kozlov ◽  
Anastasia V. Litovchenko
Keyword(s):  
Drug Resistance ◽  
Premature Death ◽  
Resistance Mechanisms ◽  
Biomedical Literature ◽  
Drug Resistant ◽  
Psychological Consequences ◽  
Text Documents ◽  
Neural Connections ◽  
Inflammatory Processes ◽  
Drug Resistant Epilepsy

Epilepsy is a chronic neurological disorder characterized by recurring spontaneous seizures. Drug resistance appears in 30% of patients and it can lead to premature death, brain damage or a reduced quality of life. The purpose of the study was to analyze the drug resistance mechanisms, especially neuroinflammation, in the epileptogenesis. The information bases of biomedical literature Scopus, PubMed, Google Scholar and SciVerse were used. To obtain full-text documents, electronic resources of PubMed Central and Research Gate were used. The article examines the recent research of the mechanisms of drug resistance in epilepsy and discusses the hypotheses of drug resistance development (genetic, epigenetic, target hypothesis, etc.). Drug-resistant epilepsy is associated with neuroinflammatory, autoimmune and neurodegenerative processes. Neuroinflammation causes immune, pathophysiological, biochemical and psychological consequences. Focal or systemic unregulated inflammatory processes lead to the formation of aberrant neural connections and hyperexcitable neural networks. Inflammatory mediators affect the endothelium of cerebral vessels, destroy contacts between endothelial cells and induce abnormal angiogenesis (the formation of “leaky” vessels), thereby affecting the blood–brain barrier permeability. Thus, the analysis of pro-inflammatory and other components of epileptogenesis can contribute to the further development of the therapeutic treatment of drug-resistant epilepsy.

scholarly journals Functional Genomics Approaches to Elucidate Vulnerabilities of Intrinsic and Acquired Chemotherapy Resistance

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 260
Author(s):  
Ronay Cetin ◽  
Eva Quandt ◽  
Manuel Kaulich
Keyword(s):  
Drug Resistance ◽  
Acquired Resistance ◽  
Chemotherapy Resistance ◽  
Resistance Mechanisms ◽  
Therapy Failure ◽  
Tightly Coupled ◽  
Unbiased Gene ◽  
Multiple Drugs ◽  
Genome Scale ◽  
Gene Perturbations

Drug resistance is a commonly unavoidable consequence of cancer treatment that results in therapy failure and disease relapse. Intrinsic (pre-existing) or acquired resistance mechanisms can be drug-specific or be applicable to multiple drugs, resulting in multidrug resistance. The presence of drug resistance is, however, tightly coupled to changes in cellular homeostasis, which can lead to resistance-coupled vulnerabilities. Unbiased gene perturbations through RNAi and CRISPR technologies are invaluable tools to establish genotype-to-phenotype relationships at the genome scale. Moreover, their application to cancer cell lines can uncover new vulnerabilities that are associated with resistance mechanisms. Here, we discuss targeted and unbiased RNAi and CRISPR efforts in the discovery of drug resistance mechanisms by focusing on first-in-line chemotherapy and their enforced vulnerabilities, and we present a view forward on which measures should be taken to accelerate their clinical translation.

Coumarin-1,2,3-triazole Hybrid Molecules: An Emerging Scaffold for Combating Drug Resistance

2021 ◽  
Vol 21 ◽  
Author(s):  
Harish C. Upadhyay
Keyword(s):  
Drug Resistance ◽  
Antimicrobial Agents ◽  
Plant Secondary Metabolites ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Biologically Active ◽  
Multidrug Therapy ◽  
Diverse Range ◽  
Development Of Resistance ◽  
Hybrid Molecules

: No doubt antibiotics have saved billions of lives, but lack of novel antibiotics, development of resistance mechanisms in almost all clinical isolates of bacteria, and recurrent infections caused by persistent bacteria hamper the successful treatment of infections. Due to widespread emergence of resistance, even the new families of antimicrobial agents have a short life expectancy. Drugs acting on single target often lead to drug resistance and are associated with various side effects. To overcome this problem either multidrug therapy or single drug acting on multiple targets may be used. The later are called ‘hybrid molecules’ which are formed by clubbing two biologically active pharmacophores together with or without an appropriate linker. In this rapidly evolving era, the development of natural product-based hybrid molecules may be a super-alternative to multidrug therapy to combat drug resistance caused by various bacterial and fungal strains. Coumarins (benzopyran-2-one) are one of the earliest reported plant secondary metabolites having clinically proven diverse range of pharmacological properties. On the other hand, 1,2,3-triazole is a common pharmacophore in many drugs responsible for polar interactions improving the solubility and binding affinity to biomolecular targets. In this review we discuss recent advances in Coumarin-1,2,3-triazole hybrids as potential antibacterial agents aiming to provide a useful platform for the exploration of new leads with broader spectrum, more effectiveness, less toxicity with multiple modes of action for the development of cost-effective and safer drugs in the future.

scholarly journals Exploiting vulnerabilities in cancer signalling networks to combat targeted therapy resistance

2018 ◽  
Vol 62 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Peter T. Harrison ◽  
Paul H. Huang
Keyword(s):  
Drug Resistance ◽  
Targeted Therapy ◽  
Kinase Inhibitors ◽  
Effective Means ◽  
Deep Understanding ◽  
Therapy Resistance ◽  
Resistance Mechanisms ◽  
Precision Oncology ◽  
First Line ◽  
Clinical Responses

Drug resistance remains one of the greatest challenges facing precision oncology today. Despite the vast array of resistance mechanisms that cancer cells employ to subvert the effects of targeted therapy, a deep understanding of cancer signalling networks has led to the development of novel strategies to tackle resistance both in the first-line and salvage therapy settings. In this review, we provide a brief overview of the major classes of resistance mechanisms to targeted therapy, including signalling reprogramming and tumour evolution; our discussion also focuses on the use of different forms of polytherapies (such as inhibitor combinations, multi-target kinase inhibitors and HSP90 inhibitors) as a means of combating resistance. The promise and challenges facing each of these polytherapies are elaborated with a perspective on how to effectively deploy such therapies in patients. We highlight efforts to harness computational approaches to predict effective polytherapies and the emerging view that exceptional responders may hold the key to better understanding drug resistance. This review underscores the importance of polytherapies as an effective means of targeting resistance signalling networks and achieving durable clinical responses in the era of personalised cancer medicine.

scholarly journals Computational Analysis of Molecular Interaction Networks Underlying Change of HIV-1 Resistance to Selected Reverse Transcriptase Inhibitors

2010 ◽  
Vol 4 ◽  
pp. BBI.S6247 ◽  
Author(s):  
Marcin Kierczak ◽  
Michał Dramiński ◽  
Jacek Koronacki ◽  
Jan Komorowski
Keyword(s):  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Molecular Interaction ◽  
3D Structure ◽  
Resistance Mechanisms ◽  
Interaction Networks ◽  
Resistance Level ◽  
Molecular Interaction Networks ◽  
Monte Carlo Feature Selection ◽  
Hiv 1

Motivation Despite more than two decades of research, HIV resistance to drugs remains a serious obstacle in developing efficient AIDS treatments. Several computational methods have been developed to predict resistance level from the sequence of viral proteins such as reverse transcriptase (RT) or protease. These methods, while powerful and accurate, give very little insight into the molecular interactions that underly acquisition of drug resistance/hypersusceptibility. Here, we attempt at filling this gap by using our Monte Carlo feature selection and interdependency discovery method (MCFS-ID) to elucidate molecular interaction networks that characterize viral strains with altered drug resistance levels. Results We analyzed a number of HIV-1 RT sequences annotated with drug resistance level using the MCFS-ID method. This let us expound interdependency networks that characterize change of drug resistance to six selected RT inhibitors: Abacavir, Lamivudine, Stavudine, Zidovudine, Tenofovir and Nevirapine. The networks consider interdependencies at the level of physicochemical properties of mutating amino acids, eg,: polarity. We mapped each network on the 3D structure of RT in attempt to understand the molecular meaning of interacting pairs. The discovered interactions describe several known drug resistance mechanisms and, importantly, some previously unidentified ones. Our approach can be easily applied to a whole range of problems from the domain of protein engineering. Availability A portable Java implementation of our MCFS-ID method is freely available for academic users and can be obtained at: http://www.ipipan.eu/staff/m.draminski/software.htm .

scholarly journals Drug Resistance Mechanisms in Mycobacterium tuberculosis

Antibiotics ◽  
2014 ◽  
Vol 3 (3) ◽  
pp. 317-340 ◽  
Author(s):  
Juan Palomino ◽  
Anandi Martin
Keyword(s):  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Resistance Mechanisms
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