American scientists were central to the creation of latest technology in the world of gene editing, the Crispr-Cas9 tool. A 2012 publication led to hopes that the technology could, potentially, lead to a cure for cancer by editing the genes in white cells to allow them to fight the disease. However, little progress has since been made in the West in terms of Crispr-Cas9 actually being put to practical use.
It is in China that the technology is being put to use as the country’s looser regulation means it is racing ahead in international gene-editing trials. The Crispr-Cas9 technology has been around since 2012 but human trials have not yet been permitted in the USA and other major Western countries. However, the lack of regulatory red tape in China means it is already being used in China to treat cancer patients and those suffering from a range of other diseases.
At the Hangzhou Cancer Hospital, a team led by Dr Wu Shixiu draws blood from cancer patients and Crispr-Cas9 is then used to ‘delete’ a gene that prevents the human immune system from effectively fighting cancer. The edited blood cells are then infused back into the patients where it is hope the edited DNA will then set about destroying cancer cells.
Crispr-Cas9 is like a pair of molecular scissors and allows scientists to cut and repair DNA. The first editing of a human cell’s genome using it was carried out by US scientists in 2013 and it is easier to use and cheaper than other gene-editing technologies.
Despite the promise of trials being conducted in China, there is concern in the West. Scientists are worried about the potential for unintended consequences resulting from use of the tool in an uncontrolled way. Human DNA still isn’t fully understood and the Crispr-Cas9 technology makes fundamental changes to it. The fear is patients being harmed in the trials taking place in China could set the field back internationally.
Forging ahead with the latest technology in the world of gene-editing was even mentioned in Beijing’s most recent 5-year plan, published in 2016. These plans outline China’s ambitions over the coming half decade and are usually focused on the country’s plans to dominate the global stage in particular industries.
Crispr-Cas9 may, however, not be a universal cure for cancer. A recent Stanford University paper suggested that some people may have immunity to Cas9 proteins used by the technology which would mean therapy would either not work or could even lead to a potentially fatal immune reaction. Even Dr Wu admits the tool represents a “two-edged sword”. However, with his patients often running out of time, the gene-editing therapy is often their only chance and so, he believes, worth the risk. So far trials have been confined to esophageal-cancer patients but will soon start on others suffering from lung and pancreatic cancers.
It is hoped that trials will also soon start in the USA, with several planned for this year, subject to cutting through federal red tape. The University of Pennsylvania has been trying to get approval for trials for two years now and hopes the breakthrough will soon be made. Publically traded companies led by the US scientists who initially developed the tool also hope to start several trials over the next 18 months.
While the ethical concerns are valid, gene-editing technology also holds the promise of leading to therapies for cancers and a number of other diseases that have so far evaded scientists’ attempts to develop consistently effective cures for.
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