The Effects of Ionizing Radiation on the Human DNA: can it Cause Cancer ?

Even today cancer is the most dreaded disease that is affecting thousands of lives all over the world. Recently a team of researchers at the Wellcome Trust Sanger Institute have identified that a significant amount of DNA damage can be caused by an ionizing radiation and lead to cancer.

Ncbi.nlm.nih.gov reported that the effects of radiation found in this research can bring a huge change in the way certain types of cancer are treated by the specialists. It will help the doctors to treat the tumors that have been caused due to radiation differently. The results of this cancer research will not only make the treatments much more effective but will also help the oncologists to understand how radiation affect the cells and causes cancer.

The findings of the research suggest that any kind of ionizing radiation like X-rays, gamma rays as well as radioactive particles are capable of damaging the human DNA. But the process of damage and the number of tumors that can be caused due to radiation and ionization still unknown to the world.

"Ionizing radiation probably causes all types of mutational damage, but here we can see two specific types of damage and get a sense of what is happening to the DNA. Showers of radiation chop up the genome causing lots of damage simultaneously. This seems to overwhelm the DNA repair mechanism in the cell, leading to the DNA damage we see." - Dr. Sam Behjati, clinician researcher, The Sanger Institute and the Department of Paediatrics, University of Cambridge

In the previous works, it was seen that any kind of DNA damage leaves a unique mutational signature. The mutational signatures of almost 12 patients who have secondary radiation-associated tumors were used in the research. The mutational signatures of these 12 patients were compared with the signatures of the 319 patients who were not exposed to any such radiation. The purpose of comparing these two signatures was to establish the ionizing radiation effects.

One of the signatures found was a deletion in which few DNA bases were cut out. The other mutational signature that was found by the research team is a balanced inversion. Here the DNA gets cut in two places and the middle part spins around and gets joined again in an opposite orientation.

"This is the first time that scientists have been able to define the damage caused to DNA by ionizing radiation." - Professor Adrienne Flanagan, a collaborating cancer researcher from University College London and Royal National Orthopaedic hospital.

Such balanced inversions cannot happen naturally in the human body. Only a high-energy radiation is capable of creating enough DNA breaks simultaneously to make it possible. Even though scientists still do not have a proper understanding of this concept it is proved that ionizing radiation can cause cancer. These mutational signatures found in the research will not only help in diagnosing individual cases but may also be helpful for a group of cancers.