RNA interference (RNAi) was discovered in the nematode Caenorhabditis elegans in 1998. It has been used to mediate post-transcriptional gene silencing (PGS) in numerous organisms, yet it's use in Mammalian cells has been questioned. In the May 2001 issue of Nature, a paper explained that 21 Nucleotide Duplexes of RNA were able to mediate RNAi within common laboratory cell cultures. This was an important finding, since RNAi will allow researchers to effectively control gene expression within mammalian cells, and one day within Humans. The purpose of my research was to confirm this study and to refine the research on siRNA. In order to do this, mammalian HELA cells were cultured and passaged every three days. They were transfected with the RNA oligonucleotides, and some were transfected with a protein that contained Green Fluorescent Protein (GFP) and the oligonucleotides. In order to check the concentration of endogenous protein within the cells, western blots were performed. The cells with GFP were observed under a fluorescent microscope to view gene expression. The siRNA fragments greatly reduced endogenous gene expression as can be seen through the western blot. The fluorescent microscopy has provided inconclusive data at this point. These results show that siRNA fragments can be used to control gene expression within mammalian cells. This provides scientists with a great new tool that can be utilized to manipulate almost every known cellular process.

This research was supported by Simons Grant 265210.