Paper published in Nature reports that microRNA-203 reduces stem cell proliferation through suppression of p63, which is overexpressed in cancer.
Researchers say that microRNA-203 helps create a tough protective barrier of cells on the surface of our skin and could potentially play a role in cancer prevention.
“As an embryo develops, the expression of microRNA-203 jumps very quickly over just two days,” says Rui Yi, Ph.D., a postdoc in Elaine Fuchs’, Ph.D., lab at Rockefeller University. “From being barely detectable at day 13, this microRNA becomes the most abundant expressed in skin.”
The researchers found that during the 13th day of development, mouse skin is primarily composed of undifferentiated stem cells. After two days, these stem cells exit the inner layer of the skin and begin to differentiate into cells that form the outermost, protective layer. microRNA-203’s expression skyrockets precisely during this period, suggesting that it plays some key role in the barrier’s development, the scientists hypothesize. The investigators also discovered that this miRNA was found only in stratified epithelial tissues and only in its outer layers.
To discover the role of microRNA-203, the researchers blocked the expression of the miRNA. The team found that the stem cells proliferated more than they did when the miRNA was expressed. As a result, the mice formed very thin skin. The researchers also found that microRNA-203 caused the stem cells to loose their ability to proliferate because it suppressed the activity of a molecule called p63, which keep cells, primarily stem cells, proliferating and is found in excess in cancer cells.
“As a next step, we are going to examine whether low expression of microRNA-203 is associated with squamous cell carcinomas,” says Dr. Fuchs, who is also an author of the study and head of the laboratory of mammalian cell biology and development. His team will investigate whether by putting back microRNA-203, they can inhibit the growth of these cancer cells.
The study was conducted by researchers at Rockefeller University and the Swiss Federal Institute of Technology ETH Zurich. The work was published in an online publication in Nature on March 2.