RNAi could potentially be used to treat a variety of diseases by targeting and blocking the function of certain genes. Particularly of interest to researchers is the potential of RNAi in treating liver disease, since RNA-carrying molecules tend to collect there.
The Liability of Lab Liver
To study the effects RNAi could have on the liver, researchers had to find a way to create an accurate model of human liver tissue in the lab. Unlike other types of tissue, liver tissue can be incredibly difficult to grow outside a human body. That meant for a time, it was difficult to predict how experimental drugs might effect the liver without administering the drugs to living subjects and evaluating their response.
A few years ago, however, Dr. Sangeeta Bhatia (a professor at MIT and member of the university’s Institute for Medical Engineering and Science) and her colleagues at MIT proved that it was possible to grow human hepatocytes (the main cells comprising the liver) on specially patterned surfaces when they were surrounded by support cells that normally surround the liver in a human body. When organized in this fashion, the lab-grown hepatocytes and support tissue act much in the way that liver tissue does in the human body.
Finally, it seemed, scientists would be able to experiment with lifelike liver tissue in a lab environment.
RNA interference uses short strands of RNA to disrupt the expression of certain genes.
The science involved is pretty dense – those hoping for an in-depth explanation of the therapy can find one here. Put simply, however, RNAi uses specially engineered segments of RNA (a type of nucleic acid that is primarily responsible for carrying instructions for protein synthesis from DNA) to target and silence specific disease-facilitating genes in a patient by intercepting and destroying the sequences of RNA that carry the instructions for the genes’ expression.
Dr. Bhatia, also the senior author of the new RNAi study coming from MIT, decided to test the efficacy of RNAi in treating both genetic and infectious disease.
The group found that the expression of genetic disease could be reduced by about 95 percent in the lab-grown liver model.
Though the results for infectious disease were less immediately promising, the researchers believe it could one day be possible to “turn down” certain genes expressed in a patient that could be a vulnerable site for pathogen infection. This could be a significant advance towards treating infectious diseases that affect the liver.
Potential for Drug Development
Dr. Bhatia and her team believe their new liver model could also be useful for the formulation of new pharmaceuticals.
Some drugs can affect or accumulate in the liver. Understanding how these drugs are metabolized differently by different individuals (and different livers) is of the utmost importance in improving their function in the future.
The ability to grow liver cells in the lab, as well as modify them with RNA to simulate differences between unique individuals, could be a game-changer in the development of the drugs of tomorrow.
How might one scientific breakthrough lead to a number of new discoveries? Do you think the lessons from MIT’s liver model could be applied to other tissue models? Share your thoughts with Patient Worthy!