What are Genes and what is DNA?
DNA is the blueprint of all living things. It is a complex string like structure made up of thousands of molecules called nucleotides. Sections of DNA are called genes. The order of nucleotides creates biological code which regulates all the chemical processes in human body. Genes are passed down from parents to their offspring and so on. Any mutation or mistake in DNA structure and sequence can lead to major serious deformities and genetic illness. For decades scientists have been looking at ways to alter DNA by cutting out, fixing or replacing the mistakes in the sequence. This will help in curing lots of genetic diseases.
What is Gene Therapy?
It is the experimental technique that uses genes to treat or prevent the genetic diseases. Genes are inserted into patient’s cell instead of drugs or surgery.
Different types of Gene Therapies include:
- Replacing a mutated gene that causes disease with a healthy copy of the gene.
- Inactivating a mutated gene that is not functioning properly.
- Introducing a new gene into the body to help fight a disease.
By the end of the 1980s and early 90s, a research team in Spain, Japan and Holland identified the parts of DNA structure that were later named CRISPR (clustered regularly interspaced short palindromic repeats). Jennifer Doudna, a biochemist at the University of California, Berkeley developed a gene editing technique in 2012 which was named as CRISPR-Cas9. These are actually certain proteins which work as “molecular scissors” for cutting the DNA at precise locations. CRISPR-Cas9 has proven to be a versatile and precise method of editing genes.
How does Gene Editing (Therapy) CRISPR-Cas9 actually work?
This technique allows scientists to edit a genome by removing, replacing or adding to parts of DNA sequence. It consists of two key molecules that work like a pair of scissors for cutting DNA.
One is an Enzyme named Cas9 that opens the DNA strand at required points and the other piece is RNA (a similar structure like DNA). RNA works as a template for repairing DNA cell. The part of the genetic material is cut out without touching the rest of DNA and a pre-designed RNA is added to that part.
During 2016, Italian scientists at Milan’s San Raffaele Telethon Institute for Gene Therapy did experiment on 18 children and cured them of a terrible immune deficiency disease, ADA-SCID. What they did was to remove the bone marrow of children, added the deficient ADA Enzyme to it for replacement.
Now a day Gene Therapy is about adding genes to one’s body for replacing the actual gene that is not working. This advancement of revising DNA of people is now becoming some of the world’s most expensive and revolutionary medicines. In humans, CRISPR-Cas9 was first tested to treat cancer. Doctors use gene engineering to reprogram immune cells called T cells to wipe out certain types of cancer. A U.S. team has plans to use CRISPR to supercharge cancer T-cell treatments.
Human Gene Editing Therapy Are OK In Certain Cases, Panel Advises https://t.co/fxcUBLC43X
— eBlogline (@sureka39331605) August 19, 2017
With lots of promising results in humans, in 2017 there will be coming more gene therapies including the treatment for hereditary blindness developed by Spark, Glaxo’s Strimvelis and cancer treatments from Novartis and Kite Pharma. It is the moment of remarkable advancement for the biotech industry.