EXAMINING THE EFFICACY OF RNAI AS A POTENTIAL GENE THERAPY IN CAENORHABDITIS ELEGANS

The World Health Organization (WHO) has stated that cancer is one of the greatest threats to humanity, with 8.3 million people dying of cancer each year and an expected 70% increase in cases in the next two decades. Current cancer treatments are relatively ineffective, with traditional treatments such as chemotherapy and radiation producing more harmful than beneficial results in many patients. Gene therapies have the potential to revolutionize healthcare in countless fields of pathology, including cancer research. In this study, the efficacy of one of these modern gene therapies, RNA interference (RNAi), was tested on the nematode worms Caenorhabditis elegans to silence the bli-1 gene as an initial step to examine the possible uses of gene therapies in cancer models. RNAi is a natural cellular process that can be harnessed to silence targeted genes. An engineered double-stranded RNA (dsRNA) strand is introduced into an organism where it is divided into smaller units of RNA by the protein Dicer, forming 21-22 nucleotide long small-interfering RNA (siRNA) strands. The siRNA are then incorporated into the RNAi-induced silencing complex (RISC) which cleaves the siRNA. The remaining antisense RNA strand leads RISC and bonds to a complementary messenger RNA (mRNA) strand corresponding to the target gene to be silenced. The resulting dsRNA is perceived as a viral RNA strand and is destroyed by the cell, therefore terminating the production of the mRNA’s respective protein and silencing that gene. In this research, a mutant Escherichia coli strain containing an RNAi-inducing plasmid was introduced to and digested by the worms through an agar medium. Using random assignment, zones of C. elegans growth were observed for the formation of blisters on the worms’ cuticles, their flexible exoskeletons, indicating bli-1 gene silencing. The proportion of blistered worms in six zones in each of the three plates was then recorded. The mean proportion of blistered worms in the three plates was 45.7% with the highest mean proportion of any plate being 53.2% in the second. The greatest proportion of blistered worms occurred in zone 3 of plate 3 at 58.3%. These promising results suggest that gene silencing can be effectively accomplished through RNAi and that further investigation of a targeting mechanism in human trials could lead to a plethora of new cures and treatments for diseases, including cancer. A future study would be investigating specific genes associated with cancer in humans such as the brc-1 and abl-1 genes in the C. elegans model.