miRNA

noun

ˌem-ˌī-ˌär-(ˌ)en-ˈā 

genetics

: microrna

Many of the noncoding RNAs, epitomized by the miRNAs, have regulatory functions in normal cells.

—Frank J. Slack et al.

A major part of this regulation is performed by microRNAs (miRNAs), small RNA molecules encoded by the genome that are not translated into proteins; rather, they control the expression of genes.

—Sebastien S. Hebert et al.

Examples of miRNA in a Sentence

Recent Examples on the Web

Native to southwest China, pandas spend up to 16 hours a day devouring bamboo, absorbing a genetic material called microRNA (miRNA) into their bloodstream, according to research published Friday in the journal Frontiers. —Chris Lau, CNN, 28 Feb. 2025

According to the study, miRNA from plants can be absorbed through food. —Monica Cull, Discover Magazine, 27 Feb. 2025

The scientists found varying miRNA profiles in their animal samples, suggesting that these plant molecules also play an important function at different stages of life – such as in reproduction and development – but much more research is needed in this area. —New Atlas, 27 Feb. 2025

Why would miRNA gene regulation work in this complicated way? —Philip Ball, Scientific American, 14 May 2024

Word History

First Known Use

2001, in the meaning defined above

Rhymes for miRNA

• sterna
• externa
• interna

Medical Definition

miRNA

noun

ˌem-ˌī-ˌär-ˌen-ˈā 

: microrna

MicroRNAs (miRNAs) are 20- to 22-nucleotide RNAs that regulate the function of eukaryotic messenger RNAs (mRNAs) and play important roles in development, cancer, stress responses, and viral infections.

—J. Ross Buchan et al., Science

Many of the noncoding RNAs, epitomized by the miRNA, have regulatory functions in normal cells. The aberrant expression of miRNA promotes tumorigenesis, metastasis, and other features of cancer.

—Frank J. Slack et al., The New England Journal of Medicine