CHAPEL HILL – Researchers at the University Of North Carolina School Of Medicine have discovered a possible cause of autism.
A key group of enzymes, called topoisomerases, can have profound effect on the genetic factors behind brain development. Associate professor in the Department of Cell Biology and Physiology, Mark Zylka, says that these enzymes work to help keep DNA normal during developing times in a child’s life.
“These are enzymes that are called topoismerases, we like to think of them as the scissors and glue for DNA,” Zylka said “so DNA is a molecule that often gets tangled up inside of cells, and to relieve these tangles, these enzymes can cut the DNA, untangle it, and glue it back together.”
When topoisomerase inhibitors are present it may limit what genes are “untangled.” Zylka said that he found when these inhibitors are present long genes and genes related to autism are the most affected.
“So what we found was that these enzymes seem to play a very important role in neurons in the brain, these are brain cells, and in particular these enzymes seem to be important for allowing genes that are very long to be expressed, and in particular a large number of genes that have been linked to autism spectrum disorders” Zylka said.
These inhibitors that affect the enzyme topoisomerases are known to exist in chemo-therapeutic drugs and have been around for over 40 years. It was while studying these drugs that Zylka first began to study the effect the inhibitors would have on neurons. Zylka says they noticed that the drugs had effects on long genes, and that autism genes are also very long.
“So that’s when we sort of put two and two together and realized that inhibiting these enzymes could have a profound effect brain development” Zylka stated.
Discovering these enzyme inhibitors can lead to new discoveries for autism and diagnosing what exactly is happening. Zylka says that he thinks studying these inhibitors can help us identify what in nature may have inhibitors like these that could cause autism.
“We found that if you inhibit these enzymes, the expression of a lot of very long genes is impaired and so a lot of these genes are autism genes,” Zylka said “and so we think this could be used as a way to diagnose or to identify other factors or chemicals in the environment with similar effects.”
Currently the known inhibitors that Zylka is studying are in Chemo-therapeutic drugs and would only affect cancer patients that are going through Chemo-therapy.