An RNA molecule called Pnky can be manipulated to increase the production of neurons from neural stem cells according to a research team led by neurosurgeon Daniel A. Lim, M.D., Ph.D. at UC San Francisco. The finding could result in medical approaches for dealing more effectively with a range of neuro degenerative diseases including Alzheimer’s and Parkinson’s. It may be of relevance also in the treatment of traumatic brain injury could and cancer.
Co-authors Alex Ramos, Ph.D. and Rebecca Andersen studied Pnky in neural stem cells in mouse brains and later found its presence in the developing human brain as well. Further, they found that when Pnky was removed from stem cells neuron production increased three to four times suggesting that “Pnky, and perhaps lncRNAs in general, could eventually have important applications in regenerative medicine and cancer treatment.” Lim observed that Pnky has an intriguing possible connection with brain tumors.
Pnky pronounced as Pinky after a popular American cartoon series Pinky and the Brain, is among one of a number of recently discovered long noncoding RNAs (lncRNAs). These are stretches of 200 or more nucleotides in the human genome that seem to have a biological function although they do not code for proteins.
Using an analytical technique called mass spectrometry, Ramos found that Pnky binds the protein PTBP1, a driver of brain tumor growth. In neural stem cells, Pnky and PTBP1 appear to function together to suppress the production of neurons. “Take away one or the other and the stem cells differentiate, making more neurons,” said Lim. “It is also possible that Pnky can regulate brain tumor growth, which means we may have identified a target for the treatment of brain tumors.”
Lim said that the larger significance of the research is that it adds to a growing store of knowledge about lncRNAs, previously unknown sections of the genome that some biologists have referred to as the “dark matter” of the human genome.