LA JOLLA The activity of pseudogenes can cause human cancers to grow faster, according to a study led by a scientist from The Scripps Research Institute.
New therapies may result from targeting pseudogenes, the study concluded.
Researchers found that certain pseudogenes can affect a tumor-suppressor gene called PTEN. Epithelial cancers grow faster when PTEN activity is blocked. The pseudogenes work in two ways, the study found. One, by directly silencing the PTEN gene. Two, by acting as a "sponge" for microRNAs affecting the protein made by the PTEN gene. These pseudogenes are derived from PTEN itself.
A previously undiscovered antisense RNA made from the pseudogenes carried out these functions, the study stated.
The study adds to evidence that pseudogenes, once considered to have no function, in some cases actually play important roles in cancers.
Kevin V. Morris, an associate professor at Scripps, was senior author of the study, published Sunday in Nature Structural & Molecular Biology. Per Johnsson, of the Karolinska Institute in Sweden, was first author.
Pseudogenes do not code for proteins, and experience mutational decay that the original genes they are derived from don't experience. Since function is conserved by natural selection, the implication is that pseudogenes are nonfunctional.
However, evidence in recent years suggest that some function is preserved in some of these pseudogenes.
"An emerging paradigm suggests that some pseudogenes may be functional in directly regulating their protein-coding counterparts at either the transcriptional or post-transcriptional level," the study stated.