A team of Chinese scientists will be the first in the world to apply the revolutionary gene-editing technique known as Crispr on human subjects. Led by Lu You, an oncologist at Sichuan University’s West China hospital in Chengdu, China, the team plan to start testing cells modified with Crispr on patients with lung cancer in August, according to the journal Nature.
CRISPR, which stands for clustered regularly interspaced short palindromic repeats, are repeats of base sequences in DNA. Scientists at Osaka University in Japan found CRISPR sequences in bacteria in 1987. Interestingly, CRISPR sequences are invariably followed by a group of genes encoding DNA-cutting enzymes, which are termed CRISPR-associated genes, or Cas for short. The potential for these sequences to be used in gene editing came as somewhat of a revelation. Researchers at Danish food manufacturer Danisco had discovered that exposure to bacteria-infecting viruses caused Streptococcus thermophilus—a bacterium used in the food industry to convert lactose into lactic acid—to insert some of the viral DNA into the spacers within CRISPR sequences. This effectively ‘vaccinated’ the bacteria against the virus, as the CRISPR sequences would guide the corresponding Cas enzymes to ‘snip out’ the viral DNA.
China has been at the forefront of Crispr research. In 2014, researchers at Nanjing University reported that they had successfully engineered mutations in macaques – the first reported successful use of the technique in non-human primates. Crispr was approved for human trials in the US by a research group backed by tech billionaire Sean Parker, but if it begins on schedule in August the Sichuan University study will beat them to the punch of being the first of its kind.
Source: theguardian.com, asianscientist.com