What is CRISPR-Cas9?
CRISPR-Cas9 is a naturally occurring defense mechanism found in bacterial cells against viral invaders. The discovery of the CRISPR-Cas9 sequences in bacterial cells goes back to the 1980s[1] but a flurry of activity took place in 2005-2008 and then again in 2011-2013 that presented a deeper understanding of the mechanisms for its occurrence and potential applications in human therapeutics.
NOVA put together the following video to better describe what CRISPR is.
Bottom-line, CRISPR-Cas9 is as an offensive gene editing tool. It works as a search and cut tool to identify the exact genetic location (CRISPR) to be cut using the Cas9 enzyme (a genomic scissor that cuts a specific nucleotide). Applications for CRISPR-Cas9 include gene knockouts, tagging or surgically cutting a single nucleotide.
CRISPR is exciting due to its potential to edit specific mutations – a field of significant interest within cancer research. While CRISPR has applications in drug discovery for target screening and identification, there are applications for CRISPR in engineering immune cells and oncolytic viruses (viruses used to target cancer cells) for immunotherapy applications.
How is CRISPR Used in Gene Therapy / Immunotherapy?
Challenges & Updates on Current Applications of CRISPR?
Recently, the specificity of CRISPR has come into question. Evidence supports that CRISPR edits have created off-target effects and have led to on-target genomic damage (made at or near where the edits were aimed. The implications of these impacts are significant – potentially leading to unintended consequences.
Discussion is ongoing regarding the need to develop a foundation for responsible, thoughtful and clear understanding for how it should be used. Two studies show that long reads generated by SMRT (single-molecule real-time) sequencing technology can more accurately detect and characterize the effects of CRISPR gene editing experiments. This can serve as a validation protocol that the CRISPR edits had the intended effect.
By: Kiran Chin
FEATURED INSIGHTS
What is genomics?
What is gene editing?
