© 2003, Elsevier Science
Small interfering RNAs (siRNAs) may be synthesized and then transfected into cells (A), or generated by the RNAase activity of Dicer (B) on short hairpin RNAs (shRNAs) transcribed in vivo (C). Transfection (D) and integration (E) of plasmid DNA containing a selectable marker and a promoter to drive shRNA expression are used to generate a stable cell line. Alternatively, DNA encoding shRNA may be introduced by viral-mediated transduction (D). siRNAs (21–22 nucleotides dsRNAs) bind to one or more proteins (F) to form the RNA induced silencing complex, RISC, which targets complementary mRNA for degradation. (From
Drug resistance stops cancer treatments in their tracks between 20% and 50% of the time. In hopes of defeating resistance, researchers have begun employing RNA interference. As various mutations accumulate during cancer's uncontrolled growth, many cells become resistant through overexpression of one protein, Pglycoprotein, which ferries drugs ...
