RNA Editing and How does RNA editing compare to DNA editing

Source: This post on RNA Editing and How does RNA editing compare to DNA editing has been created based on the article “RNA editing is promising to go where DNA editing can’t” published in The Hindu on 7th November 2024.

Why in news?

Recently, Massachusetts-based Wave Life Sciences became the first company to treat a genetic condition by editing RNA in a clinical setting.

About RNA Editing

1. RNA editing modifies specific sequences within the RNA after it has been transcribed from DNA but before it is translated into proteins.

2. A common approach involves the use of adenosine deaminase enzymes acting on RNA (ADARs).

3. These enzymes alter specific adenosine molecules in the RNA to inosine, which is then read by the cell’s machinery as guanosine, correcting errors and restoring the RNA’s original function.

4. Scientists pair ADAR with a guide RNA (gRNA) to achieve specificity directing the enzyme to the exact location of the error within the mRNA.

How Does RNA Editing Compare to DNA Editing?

1. Permanence: DNA editing introduces permanent changes to the genome, which can pose long-term risks if errors occur. RNA editing, however, only affects the RNA and thus allows for temporary changes, reducing the risk of irreversible side effects.

2. Immune Response: DNA editing techniques, such as CRISPR-Cas9, rely on bacterial proteins to cut DNA, which can trigger immune reactions.

RNA editing uses ADAR enzymes that naturally occur in the human body, lowering the risk of an immune response.

3. Delivery and Application: Delivering the RNA-editing complexes into cells typically uses lipid nanoparticles, a method proven successful with mRNA vaccines during the COVID-19 pandemic.

However, these delivery methods have a limited capacity for large molecules, presenting a challenge in RNA editing. DNA editing often requires larger viral vectors, which can carry more genetic material but introduce additional risks.

Challenges: A key issue is the specificity of ADAR enzymes, as they may affect unintended sites on the mRNA, leading to side effects.

Improving the accuracy of guide RNAs (gRNAs) is an area of ongoing research. Additionally, since RNA edits are transient, treatments will require repeated applications to maintain their effects.

UPSC Syllabus: Science and technology