What is extracellular RNA? – The Hindu

In a study published in the journal Clean Water on March 28, scientists reported that extracellular RNA (exRNA) from bacteria can persist in disinfected drinking water. They also found that by studying the exRNA, they could figure out what the bacteria were doing just before they were damaged or killed, releasing the exRNA. This way, the scientists could figure out which survival strategies worked for the bacteria — which can be used to make better disinfectants.

exRNA is RNA that exists outside cells, in body fluids such as blood, saliva, urine, and cerebrospinal fluid. For decades, scientists believed RNA only functioned inside the cell and assumed that if RNA ‘leaked’ out, enzymes in the blood would destroy it. However, researchers have found that cells in fact intentionally ‘export’ RNA.

To survive outside the cell, exRNA travels in its own molecular containers that prevent enzymes from breaking it down before it reaches its destination.

ExRNA has been found to be part of a sophisticated long-distance communication system. A cell releases RNA to deliver instructions to another cell elsewhere in the body, changing how it behaves or which genes it activates. This process helps coordinate responses in the immune system, tissue repair, and development. However, cancer cells can also release exRNA to promote tumour growth.

The discovery of exRNA changed modern medicine. For instance, just by testing a patient’s blood or other body fluids, doctors can identify specific RNA patterns linked to cancer or heart disease.