RNA Interference

Question 1

miRNA

Answer 1

Endogenous source of RNA that targets mRNA by associating with argonaute to form RISC. Can silence or degrade target.

Can negatively regulate cell proliferation genes, but a decrease in miRNA / mutation increases target gene and can induce cancer.

Can up regulate genes that inhibit cell proliferation, increase in miRNA thus leads to cancer.

Question 2

siRNA

Answer 2

Exogenous source of RNA. Also forms RISC after viruses with ssRNA genomes splice a piece of dsRNA during replication that goes on to attack RNA in host. Can be manipulated into therapy to downregulate disease genes.