Since 2012, researchers have used a powerful “genome editing” technique called CRISPR to prune, cut, replace, or add DNA to an organism’s DNA sequence. Recently, scientists at the Johns Hopkins University School of Medicine have shown that this system can also accurately and effectively change human stem cells. This finding simplifies the modification and customization of induced pluripotent stem cells (iPSCs), with the hope of achieving faster results in treatment and developing a model system for disease research and drug testing, the researchers note. Related papers published online in the recent “molecular therapy” on.
CRISPR comes from the microbial immune system, an engineering editing system that uses an enzyme that cuts a small RNA into the DNA as a guide, where it can be cut or otherwise altered. Previous studies have shown that CRISPR allows the genome to produce mutations or mutations more efficiently through these interventions, and is more efficient than other gene editing techniques such as TALEN (transcription activator-like receptor nuclease). But recent research has found that although CRISPR has many advantages, it can also produce a large number of “accidental targets” in the human cancer cell line, especially for genes that do not want to change.
To investigate whether this side effect is present in other human cells, the team used CRISPR and TALEN systems to perform experiments in human iPSCs and cut them down in iPSCs, according to a report published by the Physicists Network on Jan. 6. Known gene fragments, or cut off and then put on the other.
They used the JAK2, SERPINA1, and AAVS1 genes as models, and mutations in the JAK2 gene lead to bone marrow disorders and polycythemia vera; SERPINA1 mutations result in alpha1-antitrypsin deficiency, a genetic disorder that causes lung and liver disease ; And AAVS1 recently discovered that the human genome in the “safe harbor”, you can insert foreign genes.
The CRISPR system was significantly more effective than TALEN in the three-gene system, resulting in 100-fold cleavage compared to TALEN. In the case of gene replacement, such as substitution JAK2 and SERPINA1, CRISPR and TALEN were comparable in efficiency.
The researchers also pointed out that, unlike human cancer cell line studies, both CRISPR and TALEN also have target specificity in human iPSCs, targeting only those target genes that are set for them. They also found that the CRISPR system was more advantageous than TALEN: CRISPR could be designed to target only the mutated genes in the patient without affecting the healthy gene, which affects only one copy of a gene. These results, combined with previous stem cell research, have made CRISPR a useful tool for human iPSCs gene cloning, which is less risky to target.
Johns Hopkins University School of Medicine instructors said their study details how CRISPR technology can be used in human iPSCs to demonstrate the potential of the technology in such cells. “Stem cell technology is rapidly evolving, and we believe that the days of using iPSCs for human treatment are not far off.” (Source: ScienceDaily)