How ionising radiation damages genetic material, causes cancer
*Why men should never put their phone in their pocket
*Study shows prolonged exposure steadily destroys
For the first time, researchers from the Wellcome Trust Sanger Institute and their collaborators have been able to identify in human cancers two characteristic patterns of Deoxyribonucleic Acid (DNA)/genetic material damage caused by ionizing radiation. These fingerprint patterns may now enable doctors to identify, which tumors have been caused by radiation, and investigate if they should be treated differently. The results will also help to explain how radiation can cause cancer.
Published in Nature Communications Monday, the results will also help to explain how radiation can cause cancer.
Ionising radiation, such as gamma rays, X-rays and radioactive particles can cause cancer by damaging DNA. However, how this happens, or how many tumours are caused by radiation damage has not been known.
Also, a new study warns there is conclusive evidence that men in particular should not put their mobile phones in their pockets.
A systemic review of 21 research papers on radiation shows phones placed close to a man’s genitals for a prolonged period of time steadily drive down sperm count.
And among the studies, many suggest surviving sperm could be DMA-damaged.
The biological phenomenon is currently under fierce debate since scientists have no way to explain how non-ionizing radiation influences the body.
Without that link, many public health investigators are hesitant to say definitively that cell phones harm sperm.
However, a new review by a team at Australia’s University of Newcastle has collated years of evidence in an attempt to both emphasize the trend, and to identify potential causes.
And since 14 per cent of the world struggle to conceive – with male infertility involved 40 per cent of the time – they warn a small detail such as where one stores their phone could be crucial.
Previous work on cancer had revealed that DNA damage often leaves a molecular fingerprint, known as a mutational signature, on the genome of a cancer cell. The researchers looked for mutational signatures in 12 patients with secondary radiation-associated tumours, comparing these with 319 that had not been exposed to radiation.
Dr. Peter Campbell from the Wellcome Trust Sanger Institute who led the study, said: “To find out how radiation could cause cancer, we studied the genomes of cancers caused by radiation in comparison to tumours that arose spontaneously. By comparing the DNA sequences we found two mutational signatures for radiation damage that were independent of cancer type. We then checked the findings with prostate cancers that had or had not been exposed to radiation, and found the same two signatures again. These mutational signatures help us explain how high-energy radiation damages DNA.”
One mutational signature is a deletion where small numbers of DNA bases are cut out. The second is called a balanced inversion, where the DNA is cut in two places, the middle piece spins round, and is joined back again in the opposite orientation. Balanced inversions don’t happen naturally in the body, but high-energy radiation could provide enough DNA breaks at the same time to make this possible.
Dr. Sam Behjati, clinician researcher at the Sanger Institute and the Department of Paediatrics, University of Cambridge, said: “Ionising 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.”
Prof. Adrienne Flanagan, a collaborating cancer researcher from University College London and Royal National Orthopaedic hospital, said: “This is the first time that scientists have been able to define the damage caused to DNA by ionising radiation. These mutational signatures could be a diagnosis tool for both individual cases, and for groups of cancers, and could help us find out which cancers are caused by radiation. Once we have better understanding of this, we can study whether they should be treated the same or differently to other cancers.”
The authors of the mobile phone study wrote: “While this subject remains a topic of active debate, this review has considered the growing body of evidence suggesting a possible role for RF-EMR [radiofrequency electromagnetic radiation] induced damage of the male germ line.”
“In a majority of studies, this damage has been characterized by loss of sperm motility and viability as well as the induction of ROS generation and DNA damage.”
The authors reviewed 27 studies. Twenty-one of them showed a causal link between cell phone radiation and sperm damage.
No Comments yet