Related topics: cancer cells · genes · tumor cells · protein · rna

Nanoparticles can turn off genes in bone marrow cells

Using specialized nanoparticles, MIT engineers have developed a way to turn off specific genes in cells of the bone marrow, which play an important role in producing blood cells. These particles could be tailored to help ...

Dissecting the brain's primary developmental engine

( —Last month, researchers reported the creation of the first primitive brain-like structures made from human stem cells. To create the complex morphology of these cerebral organoids, cells within a proliferating ...

Researchers achieve RNA interference, in a lighter package

Using a technique known as “nucleic acid origami,” chemical engineers have built tiny particles made out of DNA and RNA that can deliver snippets of RNA directly to tumors, turning off genes expressed in cancer ...

Novel technique uses RNA interference to block inflammation

Massachusetts General Hospital (MGH) researchers – along with collaborators from Massachusetts Institute of Technology (MIT) and Alnylam Pharmaceuticals – have found a way to block, in an animal model, the damaging ...

Study identifies proteins that modulate life span in worms

Researchers at the Stanford University School of Medicine have identified a new group of proteins involved in determining the life span of laboratory roundworms. Blocking the expression of one member of the group can extend ...

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RNA interference

RNA interference (RNAi) is a system within living cells that helps to control which genes are active and how active they are. Two types of small RNA molecules – microRNA (miRNA) and small interfering RNA (siRNA) – are central to RNA interference. RNAs are the direct products of genes, and these small RNAs can bind to specific other RNAs and either increase or decrease their activity, for example by preventing a messenger RNA from producing a protein. RNA interference has an important role in defending cells against parasitic genes – viruses and transposons – but also in directing development as well as gene expression in general.

The RNAi pathway is found in many eukaryotes including animals and is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short fragments of ~20 nucleotides. One of the two strands of each fragment, known as the guide strand, is then incorporated into the RNA-induced silencing complex (RISC). The most well-studied outcome is post-transcriptional gene silencing, which occurs when the guide strand base pairs with a complementary sequence of a messenger RNA molecule and induces cleavage by Argonaute, the catalytic component of the RISC complex. This process is known to spread systemically throughout the organism despite initially limited molar concentrations of siRNA.

The selective and robust effect of RNAi on gene expression makes it a valuable research tool, both in cell culture and in living organisms because synthetic dsRNA introduced into cells can induce suppression of specific genes of interest. RNAi may also be used for large-scale screens that systematically shut down each gene in the cell, which can help identify the components necessary for a particular cellular process or an event such as cell division. Exploitation of the pathway is also a promising tool in biotechnology and medicine.

Historically, RNA interference was known by other names, including post transcriptional gene silencing, and quelling. Only after these apparently unrelated processes were fully understood did it become clear that they all described the RNAi phenomenon. In 2006, Andrew Fire and Craig C. Mello shared the Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm C. elegans, which they published in 1998.

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