New technique hails genetic engineering breakthrough

George Aitch  II  NOV 22 2016

It may sound like something out of a science fiction movie, but scientists are beginning to rewrite DNA.

A Chinese research team has sparked interest worldwide by attempting in vivo human genetic engineering using the novel ‘CRISPR-Cas9’ technique to tackle cancer. The CRISPR (clustered regularly interspaced short palindromic repeats) technique creates gaps in portions of selected sections of DNA, the blueprint of our body. New strands of DNA can be inserted in these gaps. In this way, parts of the genetic code can be replaced and genetic material coding for defective or harmful proteins can be rewritten.
Past attempts in genetic engineering have experimented with germ line cells, meaning that the process must occur prior to the organism’s conception, when the male and female reproductive cells meet and share genetic information. The trial from Chengdu is exciting because somatic cells have been engineered for the first time in vivo using the CRISPR-Cas9 technique. This means the technique can be used any time in the already living.

The study is using the CRISPR technique to edit T-cells which will then be injected into patients with metastatic lung cancer. T-cells were removed from the participants’ blood and were engineered to remove a protein (PD-1) which normally curbs the body’s immune response to developing cancers. By inhibiting this PD-1 protein, it is hoped that the affected T-cells will attack the cancer.

The patient volunteers will be assessed for response rate after 90 days and the number of adverse events regarding the altered cells at between 6-10 months. This will allow a direct comparison between those undergoing the technique and those not. The study hopes to provide a new pathway not for just attacking lung cancer, but new potential for the treatment of genetic disease as a whole.

The CRISPR technique has been lauded as a breakthrough as it is cheaper and more efficient than other processes. Since its first being tested in human cultures, the agent has been widely available for use by biotechnology firms and researchers. The first in vivo human trials are expected to occur in the West next year.

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Hsu PD, Lander ES, Zhang F. Development and applications of CRISPR-Cas9 for genome engineering. 2014. Cell. 157 (6): 1262–78