short interfering RNA

short interfering RNA (siRNA)

a form of double-stranded RNA (dsRNA) that mediates gene silencing, suppressing the activity of particular GENES at certain times.

See RNA-MEDIATED INTERFERENCE. SiRNAs may silence genes by degrading the mRNA, so preventing TRANSLATION. By sharing sequence homology with specific target mRNAs, siRNAs may interact to mediate cleavage in a catalytic fashion. SiRNA can inhibit HIV-1 replication by directing specific degradation of genomic HIV RNA. Synthetic siRNAs have been developed for use to decipher the functions and interactions of genes, particularly of the human genome. The ability of siRNAs to silence genes makes them potentially useful for therapeutic purposes, for example to silence ONCOGENES in CANCER treatment.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005