Recombinant DNA Technology and Gene Therapy Using Viruses
Patricia G. Melloy in Viruses and Society, 2023
Viruses do not just cause disease. Naturally or through genetic engineering, viruses can be used to help humans. Genetic engineering, also known as recombinant DNA technology, was developed about 50 years ago as a method to bring together DNA from different organisms. This technology has revolutionized biomedical research, allowing scientists to express any gene of interest in a new organism, including producing recombinant proteins such as human insulin outside of the body. Recombinant DNA technology includes the use of viruses as one type of vector to deliver a gene for expression in a new organism, and these viral vectors have been used in both gene therapy treatments and vaccines, among other applications. Gene therapy treatments involving viral vectors are being used to treat all different kinds of diseases, including cancer. Viral vectors are also used in vaccines, including COVID-19 vaccines. Undoubtedly, viruses will be a part of many therapeutic applications to prevent or treat diseases in the future.
Genetics and exercise: an introduction
Adam P. Sharples, James P. Morton, Henning Wackerhage in Molecular Exercise Physiology, 2022
We have already mentioned that DNA sequence variants influence body height, strength, VO2max trainability or disease risk. We will now discuss how variations in the DNA sequence occur, the different types of DNA variants and their frequency in human populations. But first we need to explain the vocabulary used to define DNA variants. A mutation is an event that changes a DNA sequence. The consequence of a mutation is a DNA variant. For example, a mutation may change a “…CTGT…” to a “…CTAT…” sequence resulting in a G/A DNA variant. Alleles are DNA variants of a given sequence. For example, assume that 20% of a population have a “CTGT” and 80% a “CTAT” DNA sequence in the myostatin gene (important in muscle mass regulation, covered in Chapter 4 and 8); the CTGT variant would be the minor (frequency) allele, whereas the CTAT variant would be the major (frequency) allele. Alleles with a frequency of less than 1% are referred to as rare alleles, whilst those in the range of 1–5% are known as low frequency alleles. DNA variants with a minor allele carried by 5% and more of the population are labelled as common alleles. If a one-base substitution occurs in at least 1% of a population, then it is termed a single-nucleotide polymorphism and is abbreviated as SNP. SNPs are the most studied DNA variants.
Food Interactions, Sirtuins, Genes, Homeostasis, and General Discussion
Chuong Pham-Huy, Bruno Pham Huy in Food and Lifestyle in Health and Disease, 2022
The key difference between RNA and DNA structures is that the ribose sugar in RNA has a hydroxyl (-OH) group which is absent in DNA, and the thymine base of DNA is replaced by the uracil base in RNA (107, 111–113). The nucleotides that comprise DNA include adenine (A), guanine (G), cytosine (C), and thymine (T); whereas RNA nucleotides include A, G, C, and uracil (U). Moreover, RNA has only one long strand or chain in almost species, except in some viruses, while DNA has a double strand and looks like a twisted ladder in all species from bacteria and plants to invertebrates and humans (107, 111–113). DNA is defined as a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms. The main role of RNA is to transfer the genetic code needed for the creation of proteins from the nucleus to the ribosome (111). This process prevents the DNA from having to leave the nucleus. This keeps the DNA and genetic code protected from damage. Without RNA, proteins could never be made. RNA molecules are not only involved in protein synthesis, but also sometimes in the transmission of genetic information (111).
Topo II inhibition and DNA intercalation by new phthalazine-based derivatives as potent anticancer agents: design, synthesis, anti-proliferative, docking, and in vivo studies
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Mohamed M. Khalifa, Ahmed A. Al-Karmalawy, Eslam B. Elkaeed, Mohamed S. Nafie, Mohamed A. Tantawy, Ibrahim H. Eissa, Hazem A. Mahdy
The predicted binding pattern of the co-crystallised ligand, etoposide, revealed an affinity value of −30.13 kcal/mol with the formation of six H-bonds. The planar aromatic system occupied the hydrophobic pocket formed by Glu477, Gly478, Asp479, Leu502, Arg503, Gln778, Met782, and Pro819. It was also stacked between different DNA nucleotides, namely, Cytosine (DC-8 and DC-14), Guanine (DG-7, DG-10, and DG-13), Adenine (DA-12), and Thymine (DT-9). The sugar moiety of etoposide was directed towards the DNA minor groove and stabilised by the formation of two H-bond interactions with Gln778 and DG-13. Similarly, its phenolic OH group formed two H-bond interactions with Asp479. Two H-bonds were also formed between the etoposide oxygen atoms and the DNA nucleotides DG-13 and DA-12 Figure 7.
The Role of Inflammatory Cytokines in Neovascularization of Chemical Ocular Injury
Published in Ocular Immunology and Inflammation, 2022
Alireza Shahriary, Milad Sabzevari, Khosrow Jadidi, Farshad Yazdani, Hossein Aghamollaei
Sulfur mustard is a vesicant agent that severely affects living tissues such as eyes, skin, and lung. The eyes due to humid surface environment are susceptible tissue to mustard gas damages a few hours after exposure.23 More than 100,000 Iranians were wounded by the use of SM during the Iran-Iraq war (1980–1988). Sadly, there are currently around 35,000 victims suffering from chronic symptoms of SM. 75% to 90% of exposed people are suffering from acute ocular injury, and some cases will burden the chronic phase.24 The early ocular complications of mustard gas include photophobia, burning pain, swelling of the eyelids and excessive lacrimation; however, limbal ischemia, visual impairments, and corneal neovascularization are the most characteristics of patients in chronic phase.25 Mustard gas, which is in the form of a small oily aerosol, has a toxicity ability to disrupt cell functions. Mustard is able to alkylate nitrogenous bases in the DNA and protein molecules. In consistent with abruption in DNA and protein synthesis, the cell cycle in the G2-M phase is arrested leading to a reduction in repairing and healing systems.26 Furthermore, the mustard dramatically depletes the compound of intracellular glutathione (GSH) using ROS production and H2O2 in particular. The accumulation of ROS in cells causes a massive oxidative stress in the anterior segment of the eyes. It increases inflammation of the corneal surface as the pathophysiologic basis of dry eye as well as the presence of CNV.27,28
Cytogenetic and molecular genetic methods for chromosomal translocations detection with reference to the KMT2A/MLL gene
Published in Critical Reviews in Clinical Laboratory Sciences, 2021
Nikolai Lomov, Elena Zerkalenkova, Svetlana Lebedeva, Vladimir Viushkov, Mikhail A. Rubtsov
A DNA sample that has been prepared for sequencing is referred to as a sequencing library. During the library preparation, DNA molecules are fragmented into pieces of optimal lengths, and the necessary DNA adapters required for sequencing on each specific platform and containing a primer-annealing site are ligated to the ends of each fragment. Adapters can contain a unique library index (barcode) for the simultaneous sequencing of multiple libraries (multiplexing) and unique molecular identifiers (UMIs) to improve sequencing accuracy. If the amount of input DNA is low, the DNA can be amplified. Occasionally, when preparing a library, only the regions of interest are isolated or amplified, resulting in significant savings in terms of time, costs, and data analysis. This targeted enrichment is performed through the hybridization of DNA molecules with biotinylated oligonucleotide probes against the regions of interest [107]. Alternatively, a PCR enrichment approach could be used, including anchored multiplex PCR [108], Molecular Inversion Probe [109], or another PCR-based technology, such as Ion AmpliSeq technology (ThermoFisher Scientific, Waltham, MA, USA).
Related Knowledge Centers
- Nucleic Acid
- Polymer
- Polynucleotide
- Protein
- Rna
- Virus
- Lipid
- Nucleic Acid Double Helix
- Genetics
- Reproduction
- Rna