What they have been able to demonstrate is that even the smallest change in one gene can make all the difference and with this new understanding, it is hoped it may one day prove possible to identify and treat at-risk people before they go on to develop cancer.
A gene called hTERT has been known for some time to be linked to an increased risk, or predisposition, to certain cancers such as those of the breast and ovaries. However, until now, no one knew why.
Another important area of investigation is that of telomeres – structures at the end of chromosomes that protect them from damage during cell division.
In her latest discovery, Dr Hilda Pickett has found that small variations in the hTERT gene can affect a cell’s telomeres, making them shorter than they should be. This in turn makes the cell’s chromosomes – and the DNA they contain – susceptible to damage, which increases the risk of cancer.
‘These new data provide the first real insight into why different variants, or polymorphisms, of the hTERT gene can cause susceptibility to certain cancers,’ explains Dr Pickett.
‘The hTERT gene encodes the catalytic subunit of the enzyme telomerase, which is responsible for telomere length maintenance. What we have been able to show is that certain hTERT polymorphisms result in decreased telomerase activity. It makes sense then, that if an individual has such a polymorphism, their DNA is susceptible to damage… and damaged DNA can lead to cancer.
Dr Pickett’s work has been published in the international journal PLOS Genetics, and is available here.