Chinese researchers have announced their intention to treat lung-cancer patients with cells that have been modified using CRISPR/Cas9 gene-editing method, which would mark the first time that the controversial technique had been used to alter the DNA of adult human subjects.
According to ScienceAlert, scientists at Sichuan University’s West China Hospital are planning to remove and replace faulty DNA in patients who have failed to respond to conventional forms of treatment, including chemotherapy and radiation, and are thus left with no other alternative.
The team, which is led by oncologist Lu You, will involve only metastatic non-small cell lung cancer patients and will involve the extraction of a specific type of immune cell known as a T cell from the patients’ blood. Those cells will be modified using CRISPR, then replaced in the hopes that they will trigger an immune response to combat the cancer, Nature added.
Specifically, the genes will be edited to remove a protein, PD-1, which normally prevents a cell from attacking healthy cells. A trial using a similar cancer-fighting technique has been approved in the US and could start before the end of the year, but while that trial will use antibodies, using modified DNA is far less unpredictable and more likely to provide the desired response.
“Treatment options are very limited. This technique is of great promise in bringing benefits to patients, especially the cancer patients whom we treat every day,” Lu told Nature last Thursday. “I hope we are the first, and more importantly, I hope we can get positive data from the trial.”
This will be the first time CRISPR will be used to modify human genetic code.
Cause for celebration or concern? The ethical debate continues
The deletion technique that the West China Hospital team plans to use it similar to those which have already been used to treat other patients, including purportedly saving the life of a girl with incurable leukemia. However, this will mark the first time that scientists will use CRISPR tools to genetically modify cells, according to ScienceAlert.
Carl June, a clinical immunotherapy researcher at the University of Pennsylvania in Philadelphia, called in “an exciting step forward,” while Timothy Chan, who conducts similar research at New York’s Memorial Sloan Kettering Cancer Center in New York City, told Nature that “everything will be active” in the modified T cells. “That will be a concern.”
Of course, the use of modification tools to edit human genes has been a tremendous source of controversy over the years. In fact, according to The Guardian, Peter Mills, assistant director of the UK Nuffield Council on Bioethics, has expressed concerns that using CRISPR and tools like it on humans raises the risk of creating “designer babies,” and last March, a group of researchers published an open letter in Nature raising concerns over the “ethical and safety implications” of using these techniques to modify human DNA.
“In our view, genome editing in human embryos using current technologies could have unpredictable effects on future generations. This makes it dangerous and ethically unacceptable. Such research could be exploited for non-therapeutic modifications,” they wrote. “We are concerned that a public outcry about such an ethical breach could hinder a promising area of therapeutic development, namely making genetic changes that cannot be inherited… At this early stage, scientists should agree not to modify the DNA of human reproductive cells.”
Lu assured Nature that the researchers are taking a methodical approach to their work, having spent six months in a review process before receiving permission to move forward. However, Hokkaido University bioethicist Tetsuya Ishii told the journal that China has a reputation as a country that moves (perhaps too) quickly on CRISPR related research – after all, they already have developed the first CRISPR-edited monkeys and human embryos. That, June said, is only because China “places a high priority on biomedical research.”
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Image credit: Nature
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