Chemicals and Drugs

Small Interfering RNA

Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

Small double-stranded, non-protein coding RNAs (21-31 nucleotides) involved in GENE SILENCING functions, especially RNA INTERFERENCE (RNAi). Endogenously, siRNAs are generated from dsRNAs (RNA, DOUBLE-STRANDED) by the same ribonuclease, Dicer, that generates miRNAs (MICRORNAS). The perfect match of the siRNAs' antisense strand to their target RNAs mediates RNAi by siRNA-guided RNA cleavage. siRNAs fall into different classes including trans-acting siRNA (tasiRNA), repeat-associated RNA (rasiRNA), small-scan RNA (scnRNA), and Piwi protein-interacting RNA (piRNA) and have different specific gene silencing functions.

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MeSH Record

Synonyms

28 entry terms
  • RNA, Small Interfering
  • Short Interfering RNA
  • siRNA
  • Interfering RNA, Short
  • Interfering RNA, Small
  • RNA, Short Interfering
  • RNA, Scan
  • Repeat-Associated siRNA
  • Scan RNA
  • Short Hairpin RNA
  • Small Hairpin RNA
  • Small Scan RNA
  • Trans-Acting siRNA
  • scnRNA
  • shRNA
  • siRNA, Repeat-Associated
  • siRNA, Trans-Acting
  • tasiRNA
  • Hairpin RNA, Short
  • Hairpin RNA, Small
  • RNA, Short Hairpin
  • RNA, Small Hairpin
  • RNA, Small Scan
  • Repeat Associated siRNA
  • Scan RNA, Small
  • Trans Acting siRNA
  • siRNA, Repeat Associated
  • siRNA, Trans Acting

MeSH Record

Aspects Covered

29 allowable subheadings

Indexed with the subheadings administration & dosage, adverse effects, agonists, analysis, antagonists & inhibitors, biosynthesis, blood, cerebrospinal fluid, chemical synthesis, chemistry, classification, drug effects, economics, genetics, history, immunology, isolation & purification, metabolism, pharmacokinetics, pharmacology, physiology, poisoning, radiation effects, standards, supply & distribution, therapeutic use, toxicity, ultrastructure, urine.

MeSH Record

Indexing Annotation

Do not confuse with defective interfering RNA (diRNA), a viral RNA of DEFECTIVE VIRUSES.

MeSH Record

History Note

2003; use RNA, SMALL INTERFERING (NM) 2001-2002

MeSH Hierarchy

Tree Numbers

  1. D13.150.650w.700w
  2. D13.444w.735w.150w.700w
  3. D13.444w.735w.790.552.875w

AMA Style

References

  1. National Library of Medicine. Small Interfering RNA. Medical Subject Headings (MeSH). 2026. Unique ID D034741. http://id.nlm.nih.gov/mesh/2026/D034741
  2. Small Interfering RNA. In: Wikipedia. https://en.wikipedia.org/wiki/Small_interfering_RNA
  3. Small Interfering RNA. In: Wikidata. https://www.wikidata.org/wiki/Q203221