RNAi may help control congenital birth defects

Life starts from a single fertilised egg, then the cells differentiate and develop into various organs in animals and human beings. Scientists are now trying to understand how this developmental body plan works. Until recently, it was known that proteins play an important role in the regulation and expression of genes, or the functional units of DNA, at various stages of development.

Now, research has shown that there is another biological entity called RNA Interference (RNAi), which is also responsible for the regulation of gene expressions during development. Different genes need to be expressed at different stages of growth and maintenance of the body. Thus, specific genes act at specific time points and are then shut off when their job is done.

Recently, a team of researchers, led by the husband-wife team of Manika Pal  Bhadra and Utpal Bhadra (respectively of the Indian Institute of Chemical Technology, and Centre for Cellular and Molecular Biology, Hyderabad), has unravelled the mystery of complex processes in animal and human development using RNAi. In a research paper published in the March 9 issue of the prestigious international science journal Cell, they have shown how RNAi contributes to nuclear organisation with a consequence on gene expression.

Their findings suggest, for the first time, that RNAi not only influences the regulation of a specific gene, but also helps to bring genes from different chromosomes together, promoting nuclear organisation, which is essential for development and maintenance of the organism.

Knowledge of the RNAi mechanism could be used to destroy infectious organisms, and as an effective therapy against a broad spectrum of complex and contagious diseases. “RNAi-based medicines can revolutionise gene therapy in the near future. Now, RNAi-based drugs are racing towards the clinic,” said Utpal Bhadra. “RNAi has a capacity to destroy any genetic material at any time in any specific type of cell, and is considered the most powerful gene knockout system.”

Developmental abnormalities cause birth defects in heart formation, some cancers including brain tumours and fatal neuro-degenerative diseases.

Understanding RNAi will also help find ways to correct these defects at an early stage. “The aim is to cure a disease from its genetic roots, by repairing defective human DNA or by destroying parasite DNA that frequently enter via infectious microbes, particularly air-borne viruses,” said Manika Pal Bhadra.