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CRISPR-Cas9 is a molecular machine first discovered in bacteria that can be programmed to go to an exact place in the genome, where it cuts the DNA. These precise ‘molecular scissors’ can be used to correct faulty pieces of DNA and are currently being used in clinical trials for cancer immunotherapy.
Therapeutic application of the genome-editing tool may increase the risk of cancer, scientists from Karolinska Institutet and the University of Helsinki report that the use of CRISPR-Cas9 in human cells in a laboratory setting can activate a protein-p53, which acts as a cell’s ‘first aid kit’ for DNA breaks. Once active, p53 reduces the efficiency of CRISPR-Cas9 gene editing. Thus, cells that do not have p53 or are unable to activate it show better gene editing.
Lack of p53 contributes to cells grow uncontrollably and become cancerous.
According to Dr Emma Haapaniemi, researcher at the Department of Medicine, Huddinge, Karolinska Institutet and co-first author of the study, picking cells that have successfully repaired the damaged gene might leads to inadvertently picking of cells without functional p53. If transplanted into a patient, as in gene therapy for inherited diseases, such cells could give rise to cancer.
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