MicroRNA’s are short single stranded ribose nucleic acids which regulate gene expression. They have been found in heart and muscle tissue, and some exclusively in the brain. The term was first introduced in 2001 in Science. Researchers at Rockefeller University have discovered that microRNA’s also help create our skin to protect us from bacteria and possible prevent skin cancer.

The lead authors, Yi and Fuchs, used mouse models to find where the microRNA was expressed. During the first 13th days of development, mouse skin is primarily composed of undifferentiated stem cells. On the 15th day, these stem cells exit the inner layer of the skin and begin to differentiate into cells that form the outermost, protective layer. During this time the expression of microRNA-203 skyrockets, suggesting that during development microRNA-203 has some responsibility in creating the skin barrier. When they compared this expression to humans, chickens, and zebrafish they found the pattern was identical. Yi was quoted saying “If it has been expressed in this very specific tissue for a long time and across several species, it means that it probably plays an important role there.” This group further found that the microRNA-203 suppresses a protein, p63, which stimulates skin cell growth. Without the presence of the RNA the skin grows uncontrolled, a possible reason for some skin cancers.

This is a great find to further introduce new targets for cancer drugs. In this case the authors suggest recovering microRNA-203 expression if it fails to prevent these type of cancers. In mice models this would be great evidence that certain squamous cell carcinomas are due to the lack of microRNA-203, however this could be extremely difficult to do in humans. Another possible cheaper alternative would be to design an inhibitor to the protein, p63.