In August I wrote about a team of Chinese scientists having received ethical approval in July to perform a clinical trial of gene-editing. The goal was to test whether gene-editing may be a potential cure for cancer. The trial began in a hospital in Chengdu, China in October.
The gene-editing used CRISPR-Cas9, not exactly a household name. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. Cas9 stands for CRISPR associated protein 9, an RNA-guided DNA endonuclease enzyme. If you read what these terms stand for, it can make your head hurt. It is really complex.
After reading about CRISPR more than a few times, I think I finally get the concept. I may not have this 100% right, but following is my understanding. To imagine what gene-editing is, consider editing of a video. The software shows you each frame of the video. You select a frame you want to edit and open that frame in photoshop. You make the changes to look the way you want and then insert the frame back into the video.
Now, consider the similarity with gene-editing. The human body has T-cells which are an active participant in our immune system. A gene in the T-cells produces a protein called PD-1 which disables the T-cells’ ability to trigger an immune response to fight cancer.
A team of oncologists removed cells from an advanced stage lung cancer patient and edited the cells using CRISPR-Cas9. After editing out the gene which blocks the immune response, the cells were cultured and multiplied and then injected back into the patient.
Traditional treatments are aimed at killing the cancer cells. Sometimes it works and sometimes it does not. The gene editing approach is designed to modify our DNA and have our body fight the cancer instead of chemotherapy. Some top experts are very optimistic CRISPR-Cas9 may become the cure researchers have been seeking for decades.
Although gene-editing is a breakthrough technology which could change how oncologists treat cancer. Laboratory experiments have shown it is possible to literally eliminate tumors. There are at least several significant risks, and more trials will be needed to test the safety and efficacy of gene-editing.
Carl June, an immunotherapy specialist at the University of Pennsylvania in Philadelphia is a U.S. leader in the hunt for new cancer cures. He said, “I think this is going to trigger ‘Sputnik 2.0’, a biomedical duel on progress between China and the United States”. He further said this is important since competition usually improves the end product. As of now, it looks like the Chinese are ahead in the race.
Read the full story in Nature, CRISPR gene-editing tested in a person for the first time and read more about the role of genetics in the future of healthcare in Health Attitude.