Not all cancers are due to genetic damage, say researchers in the UK. Some forms of the disease may be caused by older cells circumventing the switch that directs them to stop growing, which suggests cancers later in life may be due to the way our cells age.
The researchers, from the Cancer Research UK Beatson Institute in Glasgow, Scotland, published their results in the journal Nature Cell Biology.
They came to their conclusion when they discovered that human cells growing in their lab that were approaching the end of their lifecycle started to lose control over methylation – the process of “chemically tagging” DNA.
Patterns of this same process were observed in cancer cells, the team says.
Explaining that aging cells go through a process of senescence – when the cells stop multiplying and enter a more dormant state – the researchers say that changes in chemical tagging could prompt cells to become cancerous if they bypass the senescence process and “wake up.”
Prof. Peter Adams, study author and Cancer Research UK scientist, says:
“While aging is the biggest single risk factor for most cancers, we have a very poor understanding as to why this is. In this study we have shown that aging cells differ greatly in their behavior from normal cells.”
He notes that “the mechanisms that cause a cell to stop growing when something goes wrong or it gets too old is a surefire way of stopping tumors developing.”
However, he points out that the similar way aging cells and cancerous cells behave suggests that if those older cells circumvent the “off” switch, they could potentially become cancerous.
He says their work offers an explanation for why our cancer risk rises as we age.
“We’re only just beginning to understand how the complex machinery involved in our cells can sometimes lead to cancers,” says Kat Arney, Cancer Research UK’s science communications manager.
She adds that the recent finding provides hope for the future of cancer research:
“Understanding the fundamental processes involved in cancer is vital for developing new insights into treating and preventing this disease, bringing forward the day when all cancers are cured.”
Medical News Today recently reported on a study published in PNAS, which suggested that cold environments make cancer cells grow faster.