In a first, Chinese scientists to use stem cell tech on cancer patients

Chinese scientists will become the first in the world to inject people with cells modified using gene-editing technology in a groundbreaking clinical trial next month.

A team led by Lu You, an oncologist at Sichuan University's West China Hospital in Chengdu, received ethical approval from the hospital's review board on 6 July to test gene-edited cells on lung cancer patients next month, according to scientific journal Nature.

The cells will be modified using CRISPR-Cas9  -- a new method of genetic engineering that allows scientists to edit DNA with precision and relative ease.

"This technique is of great promise in bringing benefits to patients, especially the cancer patients whom we treat every day," Lu told the journal.

CRISPR stands for 'clustered, regularly interspaced, short palindromic repeats' - regular patterns of DNA sequences which can be edited out of genes.

Cas9 is a type of modified protein injected into a body to work on the DNA, like a pair of scissors that can snip the genes.

The technique is based on a decade-old discovery that certain bacterial cells can identify invading viruses and chop up their DNA. CRISPR-Cas9 adapts that technique to allow us to edit genes, removing harmful diseases and even allowing the creation of hybrid human-animal organs to fill the transplant gap.

According to Nature, the Chinese trial will involve lung cancer patients for whom chemotherapy, radiation therapy and other treatments have failed.

The team will extract immune cells from the patients, and edit them using CRISPR-Cas9 to knock out a gene that normally acts as a check on the cell's ability to launch an immune response and prevents it from attacking healthy cells.

The modified cells will then be multiplied and re-introduced into the patients' bloodstream where, it is hoped, they will home in on the cancer and wipe it out.

Before that can happen however, the team needs to make sure the technique is safe. The first stage of the trial next month will examine three different dosage regimens on 10 people, monitoring closely for side effects.

A similar trial planned in the US for the end of the year is currently under review at the University of Pennsylvania. It will also require approval from the federal Food and Drug Administration before it goes ahead.

Lu's trial would be the first time CRISPR-Cas9 has been used in humans. The technique has previously been tested by Chinese scientists on human embryos and in monkeys and dogs.

"I hope we are the first," Lu told Nature. "And more importantly, I hope we can get positive data from the trial."