Study finds that hybrid structures composed of DNA and RNA and enzyme RNase H play important role in DNA repair

Scientists at The Australian National University (ANU) and Heidelberg University in Germany have found an essential component in the DNA repair process which could open the door to the development of new cancer drugs.

Lead researcher Associate Professor Tamás Fischer from ANU said the research found hybrid structures composed of DNA and RNA play an important role in restoring the genetic information after the DNA is damaged. RNAs are short-lived copies of the genetic information stored in DNA. The study also discovered that RNase H enzymes that target these hybrid structures are also essential for the efficient and precise repair of damaged DNA.

“This discovery opens the possibility for the development of new drugs that can target these enzymes, modulate their activity and block or enhance the efficiency of this important DNA repair pathway,” Dr Fischer said.  He said the accumulation of mutations in the human genome was the main driving force behind ageing-related diseases and cancer development.

“RNase H enzymes have been studied and used in molecular biology for many years but their biological function was not entirely clear until now.  

Dr Fischer said one of the most surprising findings was that RNA – DNA hybrids, which were previously thought to only negatively affect the integrity of the human genome – are actually also involved in protecting the DNA.

Citation: Ohle, Corina, Rafael Tesorero, Géza Schermann, Nikolay Dobrev, Irmgard Sinning, and Tamás Fischer. “Transient RNA-DNA Hybrids Are Required for Efficient Double-Strand Break Repair.” Cell (2016).
DOI: http://dx.doi.org/10.1016/j.cell.2016.10.001
Adapted from press release by The Australian National University and Heidelberg University