China
Africa
Explore chapters and articles related to this topic
Nanoparticle-Mediated Small RNA Deliveries for Molecular Therapies
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
Ramasamy Paulmurugan, Uday Kumar Sukumar, Tarik F. Massoud
The shRNAs are another class of small RNAs with a stem of 19–29 base pairs and a loop of 4–10 nucleotides that are expressed from plasmid or viral vectors to induce RNAi-mediated gene silencing. Even though both siRNA and shRNA mediate target gene silencing by similar RNAi mechanisms, the siRNA is delivered as a synthetic double stranded RNA, while shRNA is expressed as a dsRNA with a loop structure using gene expression vectors [101]. The expression of shRNA in cells can be achieved by delivery of plasmids or via viral vectors. The shRNA vectors commonly utilize an U6 promoter, a type III RNA polymerase III promoter, to achieve a primary transcript for its further processing using an endogenous RNAi mechanism [102–104]. shRNAs have been extensively used for various applications including cancer therapy and in drug screening for target specific identification of small molecule drugs.
RNA Structural Modeling for Therapeutic Applications
Published in Peixuan Guo, Kirill A. Afonin, RNA Nanotechnology and Therapeutics, 2022
Yi Cheng, Dong Zhang, Travis Hurst, Xiaoqin Zou, Paloma H Giangrande, Shi-Jie Chen
The laborious and costly process of experimentally testing for efficiency and potency of each designed RNA—accounting for off-target effects—has increased demand for more efficient methods. Computational modeling and design are highly desirable approaches to improve the efficiency of RNA nanotechnology. For example, we can utilize computational models that consider RNA/RNA interactions to identify targets on mRNA and then find the most potent siRNA/shRNA for specific gene knockdown (Lai and Meyer 2016). Efficient computational methods such as GUUGle (Gerlach and Giegerich 2006), RNAhybrid (Rehmsmeier et al. 2004, Kruger and Rehmsmeier 2006), and RNAduplex (Hofacker et al. 1994) were developed to predict miRNA targets by considering the intermolecular interactions of complementary base pairing or free energy of stacking. Then, RNAup (Muckstein et al. 2006), IntaRNA (Busch, Richter, and Backofen 2008, Richter et al. 2010, Smith et al. 2010, Mann, Wright, and Backofen 2017), and RNAplex (Amman et al. 2011) models were developed to improve predictions by accounting for intramolecular interactions. By allowing for intramolecular interactions, these models include the accessibility of the corresponding mRNA site of miRNA binding in their predictions. In addition to computing miRNA targets, these algorithms can also consider siRNA, shRNA, and other small RNA (sRNA) targets. Based on these algorithms, RNApredator (Eggenhofer et al. 2011) and CopraRNA (Wright et al. 2013, Wright et al. 2014) models further improve prediction by accounting for small bacterial sRNA targets.
DNA/RNA Nanoparticles Structures for siRNA Delivery Applications
Published in Loutfy H. Madkour, Nanoparticle-Based Drug Delivery in Cancer Treatment, 2022
The major barrier facing siRNA therapeutics is the efficiency of delivery to the desired cell type, tissue, or organ. siRNAs do not readily pass through the cell membrane due to their size and negative charge. Cationic liposome-based strategies are usually used for the cellular delivery of chemically synthesized or in vitro transcribed siRNA [38]. However, there are many problems with lipid-based delivery systems in vivo, such as rapid clearance by the liver and lack of target tissue specificity. Delivery systems can be categorized into physical methods, conjugation methods, and natural carrier (viruses and bacteria) and nonviral carrier methods [39]. DNA-based expression cassettes that express shRNA are usually delivered to target cells ex vivo by viruses and bacteria, and these modified cells are then reinfused back into the patient [40]. The popular adenovirus-derived vectors and AAV-derived vectors provide efficient delivery for the shRNA expression [9]. However, there are problems with delivery using viral vectors, such as insertional mutagenesis and immunogenicity [41]. Nonviral gene delivery systems are highly attractive for gene therapy because they are safer and easier to produce than viral vectors.
Genetic variants affecting chemical mediated skin immunotoxicity
Published in Journal of Toxicology and Environmental Health, Part B, 2022
Isisdoris Rodrigues de Souza, Patrícia Savio de Araujo-Souza, Daniela Morais Leme
The importance of FLG in preventing skin immune reactions was confirmed by several other in vivo studies. Kawasaki et al. (2012) showed that the skin of FLG-deficient mice exhibited higher antigen penetration, leading to enhanced responses in hapten-induced CHS and higher anti-ovalbumin IgG1 and immunoglobulin E (IgE) serum levels. Moniaga et al. (2010) also reported that FLG-deficient mice developed clinical and histological eczematous skin lesions similar to human AD displaying a defective skin barrier and generating proallergic mice responsive to 1-fluoro-2.4- dinitrobenzene (DNFB) sensitizer and phorbol myristate acetate skin irritant. FLG-deficient mice demonstrate a reduced barrier function with enhanced sensitization to DNFB and skin irritation to croton oil irritant exhibiting increased immune responses (Kawasaki et al. 2012). Dang et al. (2015) using cultured normal human epidermal keratinocytes showed that FLG silencing by short hairpin RNA (shRNA) directly impaired skin barrier function and induced a Th2 immune response, which is recognized as an allergic type of immune response.
Cytochrome P450 1B1 promotes cancer cell survival via specificity protein 1 (Sp1)-mediated suppression of death receptor 4
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Yeo-Jung Kwon, Nam-Hyeon Cho, Dong-Jin Ye, Hyoung-Seok Baek, Yeon-Sang Ryu, Young-Jin Chun
The optimal sequence of si RNAs targeting human CYP1B1 (5ˊ-GCGACATGATGGACGCCTTTAT-3ˊ) was cloned into the plasmid pLKO.1 which encodes a human immunodeficiency virus (HIV)-derived lentiviral vector containing a multiple cloning site for the insertion of shRNA constructs to be driven by an upstream U6 promoter. This modified plasmid or empty vector were further co-transfected into HEK293T cells with lentiviral packaging plasmids to generate CYP1B1 or control shRNA lentivirus. After virus construction, MDA-MB-231 cells were infected with the constructed control and CYP1B1 shRNA lentivirus for 24 hr, and infected cells were selected using puromycin treatment. After 24 hr, media was replaced with puromycin-free growth media and cells were cultured for further CYP1B1 knockdown studies.
Preparation and characterization of novel albumin-sericin nanoparticles as siRNA delivery vehicle for laryngeal cancer treatment
Published in Preparative Biochemistry and Biotechnology, 2019
Eda Yalcin, Goknur Kara, Ekin Celik, Ferda Alpaslan Pinarli, Guleser Saylam, Ceren Sucularli, Serhat Ozturk, Esin Yilmaz, Omer Bayir, Mehmet Hakan Korkmaz, Emir Baki Denkbas
In 2014, short hairpin RNA (shRNA) mediated RNA interference (RNAi) technology was used to inhibit CK2α expression in Hep-2 laryngeal carcinoma cells. A significant reduction in both mRNA and protein levels of endogenous CK2α was shown in the study. The results also indicated that silencing CK2α resulted in an apoptosis rate of 60% by conducting flow cytometry assay.[42]