Enhanced method triples the suppressive ability of CRISPR technology

In a groundbreaking study published in BioDesign Research, a team of scientists from Stanford University, including Dr. Lei S. Qi, have developed a new CRISPR-Cas9 system that induces highly effective, long-term silencing of target genes. This system, named dCas9-KAL, could have significant implications for the treatment of various genetic ailments, including cancer.

The versatility of CRISPR-Cas9-based gene editing is achieved by modifying the Cas9 protein itself, resulting in a deactivated Cas9 (dCas9) that can be fused with various gene expression-altering enzymes for targeted binding to specific DNA sites. When fused with an activating or repressing transcription factor, the dCas9 complex upregulates or downregulates the target gene, respectively. However, the effects are transient, making a longer-lasting solution a desirable goal for practical applications.

To address this, the researchers fused dCas9 with the transcription repressor domain KRAB and DNA methylating domains of DNMT3L and DNMT3A. This construct, named dCas9-KAL, repressed fluorescence for weeks when stably integrated into human cells expressing fluorescent protein EGFP.

Dr. Lei S. Qi, one of the major contributors to the development of CRISPR technology for genome engineering, received his Ph.D. degree in Bioengineering from UC Berkeley and UCSF (joint program), USA. He is currently affiliated with Mammoth Biosciences, South San Francisco, United States. His areas of research interest include CRISPR, Genome Editing, Synthetic Biology, and Cell Engineering.

The unique construct-synthetic reporter system developed in this study will help scientists in assessing the activity of various domains or their combinations fused to dCas9. The research was also conducted by Dr. Kiran R. Patil from the University of California, San Francisco, and was authored by Muneaki Nakamura, Alexis E. Ivec, Yuchen Gao, Lei S. Qi, and published in BioDesign Research with the DOI: 10.34133/2021/9815820.

The success in developing a robust and long-term epigenetic repressor has multifold implications. For practical purposes, such as suppressing the effect of a disease-causing mutation, a longer-lasting effect of silencing is desirable. The team's findings make a noteworthy addition to the CRISPR-Cas9 system, potentially facilitating further research in the field and the development of custom cell types with wide-ranging research and therapeutic applications.

The CRISPR-Cas9 system, originally discovered as a bacterial defense mechanism, is a popular gene editing tool among researchers due to its ability to modify specific DNA locations. This latest development by the Stanford team could pave the way for more efficient and long-lasting gene editing, opening up new possibilities in the field of genetic research and therapy.