CRISPR-Cas9 is an efficient and versatile tool for genome engineering in many species. However, inducible CRISPR-Cas9 editing systems that regulate Cas9 activity or sgRNA expression often suffer from significant limitations, including reduced editing capacity, off-target effects, or leaky expression. Here, we develop a precisely controlled sgRNA expression cassette that can be combined with widely-used Cre systems, termed CRISPR-Switch (SgRNA With Induction/Termination by Cre Homologous recombination). Switch-ON facilitates controlled, rapid induction of sgRNA activity. In turn, Switch-OFF-mediated termination of editing improves generation of heterozygous genotypes and can limit off-target effects. Furthermore, we design sequential CRISPR-Switch-based editing of two loci in a strictly programmable manner and determined the order of mutagenic events that leads to development of glioblastoma in mice. Thus, CRISPR-Switch substantially increases the versatility of gene editing through precise and rapid switching ON or OFF sgRNA activity, as well as switching OVER to secondary sgRNAs.
Category: bioengineering – Page 128
We’ve long known that viruses can target cancers in our bodies. Now, thanks to gene editing, we’re using them as tumour search and destroy agents – and getting our immune systems to join the fight too.
Biochemical makeover allows Escherichia coli to use carbon dioxide as a building block for its cells.
Just seven years after scientists announced the first use of Crispr-Cas9 gene editing technology on human cells, researchers shared new evidence this week that Crispr can be used to cure two serious genetic disorders.
On Tuesday, NPR reported that a patient in Nashville had seen a dramatic decline in her symptoms of sickle cell disease after receiving a single gene therapy treatment in July. Sickle cell, which can lead to inflammation, debilitating pain, and life-threatening circulatory problems, affects millions of people around the world.
That same day, the biotech companies behind the sickle-cell treatment, Crispr Therapeutics and Vertex, also shared promising results from their first attempt to cure a case of beta thalassemia, another genetic disorder that affects blood proteins. Nine months after receiving the experimental treatment, a patient in Germany with beta thalassemia has almost no signs of the disorder.
Promising preliminary data from one of the first human trials testing the safety and efficacy of a CRISPR gene therapy has just been revealed. Although it is too early to evaluate long-term effects, the initial reports are impressively successful for two patients with severe genetic blood diseases.
Until February of this year, when pharmaceutical companies CRISPR Therapeutics and Vertex began a large global trial into a treatment called CTX001, no human outside of China had been officially treated with a CRISPR-based gene editing therapy.
CTX001 was developed to treat two types of inherited blood disease, beta-thalassemia and sickle cell disease. Both conditions are caused by a mutation in a single gene and the treatment involves engineering a patient’s stem cells with a single genetic change designed to raise levels of fetal hemoglobin in red blood cells.
When an undiagnosed rare genetic disease caused his young son’s kidneys to fail, Professor Chris Toumazou vowed to find a way of uncovering hidden health risks.
The professor of biomedical engineering realised that, although his son’s condition could not have been prevented, the family could have managed his lifestyle very differently had they known about his condition.
So, he embarked on a mission to help people change their lifestyles and avoid getting sick.
Doctors have reported on the first attempts in the United States to use gene editing to help patients fight cancer.
The doctors say one form of gene editing appeared to be safe when tested in three patients. But it is not yet known what long-term effects the method will have on cancer treatment or patient survival rates.
A gene editing tool called CRISPR/Cas9 was used in the tests, which were recently reported in a medical study. The method was discovered in recent years as a way to change the genetic material that make up a person’s DNA.