Recent Advances in Genome-Editing Technology with CRISPR/Cas9 Variants and Stimuli-Responsive Targeting Approaches within Tumor Cells: A Future Perspective of Cancer Management

Abstract

The innovative advances in transforming clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) into different variants have taken the art of genome-editing specificity to new heights. Allosteric modulation of Cas9-targeting specificity by sgRNA sequence alterations and protospacer adjacent motif (PAM) modifications have been a good lesson to learn about specificity and activity scores in different Cas9 variants. Some of the high-fidelity Cas9 variants have been ranked as Sniper-Cas9, eSpCas9 (1.1), SpCas9-HF1, HypaCas9, xCas9, and evoCas9. However, the selection of an ideal Cas9 variant for a given target sequence remains a challenging task. A safe and efficient delivery system for the CRISPR/Cas9 complex at tumor target sites faces considerable challenges, and nanotechnology-based stimuli-responsive delivery approaches have significantly contributed to cancer management. Recent innovations in nanoformulation design, such as pH, glutathione (GSH), photo, thermal, and magnetic responsive systems, have modernized the art of CRISPR/Cas9 delivery approaches. These nanoformulations possess enhanced cellular internalization, endosomal membrane disruption/bypass, and controlled release. In this review, we aim to elaborate on different CRISPR/Cas9 variants and advances in stimuli-responsive nanoformulations for the specific delivery of this endonuclease system. Furthermore, the critical constraints of this endonuclease system on clinical translations towards the management of cancer and prospects are described.

Emerging Strategies in Mesenchymal Stem Cell-Based Cardiovascular Therapeutics

“…For example, understanding the specific signaling molecules and transcription factors, such as stromalderived factor-1 (SDF-1) and bone morphogenic protein-2, involved in MSC differentiation can lead to the development of biomaterials or scaffold-based approaches that mimic the natural niches of these cells, thereby enhancing their differentiation efficiency and therapeutic efficacy in situ [58]. Moreover, genetic engineering techniques, such as CRISPR/Cas9 and RNA interference, are being explored for the manipulation of these molecular pathways, enhancing the precision of and control over MSC differentiation [59]. The following studies present significant advancements in the field of MSC differentiation and therapeutic applications facilitated by CRISPR/Cas9 technology.…”

Recent Advances in Understanding the Molecular Mechanisms of Multidrug Resistance and Novel Approaches of CRISPR/Cas9-Based Genome-Editing to Combat This Health Emergency

“…Some novel targeting approaches also involve the nanoparticle encapsulated phage-CRISPR/Cas9 system delivery methods. 87 , 121 However, the search for more innovative targeting approaches is going on to minimize comprehensively the antibiotic resistance complication in the near future. A brief description of some delivery approaches of CRISPR/Cas9 system through phages, plasmids, nanoparticles and extracellular vesicles in different bacterial cells is given below.…”

Evolution of CRISPR/Cas Systems for Precise Genome Editing

“…Currently, numerous high-fidelity Cas9 variants have been engineered or developed, such as SpCas9-HF1 [ 16 ], HiFiCas9 [ 17 ], evoCas9 [ 18 ], eSpCas9 [ 19 ], HypaCas9 [ 20 ], Sniper-Cas9 [ 21 ], and xCas9 3.7 [ 22 ]. However, the increased fidelity of these variants is usually associated with decreased editing efficiency [ 23 ]. It is also of importance that the number of available genome-editing sites for the most widely used Streptococcus pyogenes Cas9 protein is limited by the protein’s dependence on the PAM sequence (5′-NGG-3′).…”