The revolutionary gene-editing system CRISPR/Cas9 was used for the first time in a human patient at West China Hospital on 28 October 2016.
The oncologist Lu You and his research group at Sichuan University in Chengdu, China, modified immune cells from the blood of a patient with aggressive non-small cell lung cancer. These cells, altered with the CRISPR/Cas9 gene scissors, were then multiplied and injected back into the patient. The aim of this treatment is to outwit the cancer cells. By removing the gene for the protein PD-1 (programmed cell death protein 1), the immune cells (T cells) in this specific case are genetically reprogrammed to fight the tumour. The PD-1 protein produced by T cells is used by tumour cells to evade the body’s immune response.
The genetically optimised cells should thus be able to act effectively against the tumour again. This principle is similar to modern cancer immunotherapies in which antibodies against PD-1 are used.
The treatment has so far proceeded without complications, and the patient is to receive a further injection. In the next step of the study, a total of ten patients will receive up to four injections and will be observed for six months. After this first observation phase of 6 months, it should already be clear whether the patients benefit from the therapy and whether serious side effects occur.
A worthwhile race for CRISPR/Cas9 between the world powers
The Chinese researchers are thus one step ahead of a US research team, which only carried out the first applications with CRISPR-modified cells at the beginning of 2017. In that case, three different genes are said to have been modified in order to treat different types of cancer. Researchers in Beijing have also submitted applications for studies of CRISPR/Cas9 in bladder, prostate and renal cell carcinomas, but these had not yet been approved shortly before the end of 2019.
In the journal Nature, the immunotherapy specialist Dr Carl June of the University of Pennsylvania speaks of the beginning of a biomedical race. Dr June sees this scientific competition between China and the USA positively, as it will lead to faster and better product development.
Before the revolutionary gene scissors were used in humans in 2016, CRISPR/Cas9 had developed in recent years into the leading method for “genome editing”. Here, an RNA molecule binds in combination with an enzyme that cleaves the DNA double strand at a specific section. The resulting defect can be repaired by the cell’s own enzymes, or a modified strand can be inserted at this point. It is also possible simply to switch off gene sequences.
Sources:
Nature 539, 479 () doi:10.1038/nature.2016.20988
