China to carry out first human gene editing trial for lung cancer

A group of Chinese scientists will be performing the world’s first genetic editing trial on humans in August 2016. The trial will be done in an attempt to find a cure for lung cancer. A team led by Dr. Lu You at Sichuan University’s West China Hospital in Chengdu received approval to carry out the trial from the hospital’s review board on 6 July 2016. The world’s first genetic editing trial on humans will be based on

CRISPR–Cas9 technique.

What is CRISPR?

The full form of CRISPR is Clustered Regularly Interspaced Short Palindromic Repeats.

CRISPRs are segments of prokaryotic DNA containing short repetitions of base sequences.

Each repetition is followed by short segments of spacer DNA from previous exposures to a bacteriophage virus or plasmid.

The CRISPR/Cas system is a prokaryotic immune system that confers resistance to foreign genetic elements and provides a form of acquired immunity.

The Cas protein use the CRISPR spacers to recognize and cut these exogenous genetic elements in a manner analogous to RNA interference in eukaryotic organisms.

CRISPRs are found in approximately 40% of sequenced bacterial genomes and 90% of sequenced archaea.

By delivering the Cas9 nuclease and appropriate guide RNAs into a cell, the cell's genome can be cut at a desired location, allowing existing genes to be removed and/or new ones added.

CRISPRs have been used in concert with specific endonuclease enzymes for genome editing and gene regulation in species throughout the tree of life.

The process

• CRISPR technology lets scientists selectively edit genome parts and substitute them with novel DNA fragments.

• Cas9 is an enzyme that has the capacity to edit DNA.

• The genes undergo modification for the better via this procedure. A lot of cutting and pasting takes place at the genetic level through the technique.

• There will be 10 volunteers who will all be lung cancer patients.

• The CRISPR-Cas9 gene editing will last between two and three months. However, the trial still could go on for 365 days or more.

• T cells will be extracted from the blood of the patients. The gene that stored PD-1 protein will be deleted. The process normally limits the cells’ capacity to trigger an immune response.

• Now, the edited cells will be cultured in the lab after their reintroduction in the patients’ blood. This will start the immune response, which will kill the lung cancer tumours.

Read more Current Affairs on: CRISPR , Cas9 , Gene Editing , Lung Cancer , Gene Editing Trial on Humans , Who: First human gene editing trial , What: To be carried out by Chinese scientists , When: To be carried out in August 2016 , Why: To find a cure for lung cancer , China to carry out first human gene editing trial for lung cancer