CRISPR ways of human gene-editing

In the Cage series, I found the creation of Luke Cage by scientists using a gene-editing tool called CRISPR simply fascinating. Scientists alter Carl Lucas into Luke Cage by cloning his DNA with abalone DNA, transforming Cage into a superhero with superhuman strength and bulletproof skin. 

CRISPR is a new revolutionary gene-editing technology that scientists today are using to change the genetic blueprint of plants and animals and even humans. It is one of the greatest science stories of this decade, having the capability to change the world. CRISPR is an acronym for ‘Clustered Regularly Interspaced Short Palindromic Repeat’ which refers to short, partially palindromic repeated DNA sequences found on the genomes of bacteria and other microorganisms. 

Since the beginning, forces of random mutation and natural selection have forged human evolution. CRISPR is unprecedented in the history of life on earth as it has conferred on humans the power of God to manipulate our DNA and the genome of the generations to come. Are humans adequately equipped to exercise this mind-blowing power beyond our grasp and comprehension? 

CRISPR/CAS9 is an immune mechanism developed by bacteria to fend off assaults by invading viruses. When a bacterium detects an invading virus, it produces enzymes that chop the virus into bits and pieces; some of which get installed in the host DNA as a rogue’s gallery. During future viral attacks, if the genetic information of the invading pathogen matches the info available on the rogue’s gallery, the CAS9 enzyme swings into action and annihilates the invading viral DNA. 

Jennifer Doudna of the University of California Berkeley and Emmanuelle Charpentier of Umeå University in Sweden in 2011, while studying the mechanism of CAS9 enzyme, discovered that they could easily hoodwink the Cas9 protein to slice the DNA by deploying an artificial RNA. They found CAS9 could scan and shred genetic elements with identical code, not just viruses but also the DNA of any organism. Using the CRISPR/Cas9 system, the researchers proved they could cut any genome anywhere to insert or delete genes. For this stunning discovery, Jennifer Doudna and Emmanuelle Charpentier won the Nobel Prize in Chemistry in 2020. 

The CRISPR/Cas9 gene scissors hold the promise of being a utopian application with its potential for catalysing new scientific discoveries, better crops and new weapons to fight cancer and genetic diseases. It is anticipated that CRISPR will soon fix genetic disorders such as cystic fibrosis, sickle cell anaemia, muscular dystrophy and cure cancer and Huntington’s disease. Doudna and others have recently created RNA-guided enzymes that can directly detect the COVID-19 virus and eventually destroy it. Scientists have also developed a test that detects the COVID-19 virus in just 5 minutes using the CRISPR tool. 

The human genome comprises 3.2 billion letters. CRISPR can execute the incredible feat of finding an erroneous letter in the clutter of 3.2 billion nucleotides and hack off the inexact or the mutated gene, leaving the rest intact. For instance, individuals afflicted with sickle-cell anaemia disorder of the haemoglobin have just a single mutation in the gene coding for haemoglobin. Using CRISPR, it would be possible to replace the missing nucleotide in the DNA, alleviating the millions who suffer from this devastating syndrome. Some medics have already begun treating a few cancers by cloning DNA sequences to the genes of the immune cells to hunt down and obliterate malignant tumour forming cells. It is also possible to produce designer babies and revamp our children’s external appearance, such as modifying their hair and eye colour or even their body shape, height, weight, and intelligence. 

Recently, the Yunnan laboratory in Kunming, China, tinkered the genome of Macaque monkeys with CRISPR to produce monkeys with purple eyes, orange eyes, and several other colours. Eye colour may be only a start. This technology can make infinite types of genetic alterations. Although researchers have not attempted such things on humans, it looks like it’s just a matter of time before CRISPR based remedies become available to all as CRISPR works well in human cell cultures, Besides the beneficial side, CRISPR also has a dystopian side because of its possible misuse by criminals to develop bio-weapons. A global threat assessment document published in 2016 by US director of national intelligence James Clapper positioned genome editing among six top threats listed in the section on weapons of mass destruction. 

The grimmest and catastrophic thing about CRISPR is that any attack won’t be just a one-time event that restricts itself to a particular area or time. For instance, when suicide bombers explode themselves or when bombs are detonated, the fatalities and devastation would stay limited to the area around the explosion. Bio attacks can spread globally and have worldwide ramifications. When CRISPR tech changes any gene, it does not restrict the harm to a lifetime, but it makes it inheritable by future generations. 

Further, a bioterrorist could take a benign virus and program it to disrupt or repress functions inside human cells by using CRISPR. The 10th season finale of The X-Files, ‘My Struggle II’ has a CRISPR storyline — in which aliens design a virus that contains a CRISPR system that destroys a gene coding `for an enzyme critical for the immune system of humans. Only select individuals who possess some alien DNA can survive the virus. On similar lines, fundamentalists who are antagonistic and opposed to a particular belief or sect could use CRISPR to create a virus that could render the males of a specific sect impotent or make females incapable of conceiving a baby. 

A bioterrorist would achieve this task without killing or injuring a single human being just by exploiting the genetic peculiarities of a race or people belonging to a sect. Such an attack would be anonymous and leave no clues for apprehending the perpetrator even decades after the attack. Another fear that police have is that criminals could use this technology to evade DNA tests by altering their DNA using the CRISPR kits available online for just $100. However, experts doubt it could happen in reality as it would require high sophistication to achieve.