: microrna
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.

Example Sentences

Recent Examples on the Web Shown are a variety of nucleic acids — messenger RNA (mRNA), microRNA (miRNA), piwi-interacting RNA (piRNA), small nucleolar RNA (snoRNA) — as well as classes of proteins that serve different functions. Matías A. Loewy, Discover Magazine, 25 Mar. 2023 The findings suggest that the specific serum miRNA profiles may serve as fingerprints for disease diagnosis. Chao Yan, Scientific American, 17 June 2020 In 2017, Lönnerdal and his colleagues explored this question by exposing miRNA-containing exosomes from breast milk to acidic conditions that mimic those in the infant gut and observing how the packages fared2. Tien Nguyen, Scientific American, 17 June 2020 So a single miRNA might match 20–50 mRNAs, Hicks says. Tien Nguyen, Scientific American, 17 June 2020

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'miRNA.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

2001, in the meaning defined above

Time Traveler
The first known use of miRNA was in 2001

Dictionary Entries Near miRNA

Cite this Entry

“MiRNA.” Dictionary, Merriam-Webster, Accessed 30 May. 2023.

Medical Definition

: 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
Last Updated: - Updated example sentences
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