Function
siRNA is integral to RNA interference (RNAi), as it is the principal nucleic acid involved in the regulation of gene expression through the PTGS pathway. The function of siRNA can be discerned through experiments and screenings focusing upon the expression of given proteins and any off-target effects. Furthermore, such analytical techniques can be incredibly useful in the identification of novel gene regulation pathways and potential off-target effects for gene therapies based on RNAi.
Therapeutic Applications
Currently, a new wave of therapeutics using RNAi is being developed in preclinical and clinical trials. This new class of drug compounds and ways to shorten the development process from beginning to end depends on the near-term success of RNAi in vitro and in vivo functional and screening experiments. Treating conditions that have not responded to traditional drugs is an exciting avenue enabled by RNAi technologies. By utilizing the synergistic effects of small molecules and RNAi therapeutics, pharmaceutical companies are able to reduce toxicity effects while increasing the efficacy of their drugs in danger of failing clinical trials.
Function and screening services for RNAi help to identify druggable targets, screening of genome-wide activity, and assay development. Often, researchers require the help of RNAi experts in the design and execution of targeting genes of interest associated with their particular disease of study. This interest is coming from research institutions worldwide, including pharmaceutical and biotech companies along with academic institutions.
In terms of medical functionality, siRNA can be used as a potent gene suppression tool, a function that could potentially end up curing genetic diseases and abnormal expression conditions. Although current development is only recent in nature, with time the potential of siRNA will be explored and perhaps become the foundation for novel therapeutic programs that involve the specific regulation of expression. This may prove advantageous if modifying a genome can bring along undesired effects; a gene can encode for many proteins, and if only one protein is problematic, then siRNA technology may be of more use than genetic modification of nucleic DNA.
The ability for siRNA screens to assess up to whole genomes in organisms gives rise to many therapeutic possibilities. In one instance, Martin et al. used a genome-wide siRNA screen to find an essential host pathway for the Ebola (EBOV) virus life cycle that could then be targeted with a drug. The screening consisted of 64,755 individual siRNAs compared to 21,566 human genes to analyze their role in EBOV genome replication or transcription. They found that the de novo pyrimidine synthesis pathway was involved in the EBOV life cycle, and the FDA-approved drug (teriflunomide) that targeted this pathway yielded a high efficacy to EBOV infections in vitro. Other drugs that are known to target the same pathway can now be further investigated to be potential treatments of Ebola as well. On the other hand, other diseases that utilize the de novo pyrimidine synthesis pathway can also benefit from the same drugs. siRNA screenings show its usefulness by allowing for life cycle models to be created and analyzed for the treatment of many diseases.
siRNA Screening
RNAi technology is still fairly new and many laboratories are not setup to perform RNAi screening. This is where it is in the best interest of researchers to have experts design and conduct screening experiments. siRNA libraries may contain over 50,000 individual oligonucleotide molecules to screen. Experiments may include replicates, and one can easily see that an experiment in one cultured cell line can exceed over 100,000 data points. As a result, automation of RNAi screening has been integrated into the workflow to accomplish what most laboratories would take years to accomplish. The libraries can be used to screen genes associated with particular phenotypes due to loss-of-function, signaling research, identification of biomarkers, oncology research, and a vast array of other biomedical experiments.
In technical terms, siRNA screening involves high-throughput cellular assays that are focused on measuring the target effects of the siRNA transfection. Although single screenings are generally speaking simple to perform, the accuracy necessitated by research and the larger amount of samples to be tested in larger scale experiments require automation and experience. In such cases, hiring a company to perform screenings for research is advantageous and risk-free.