Cancer-causing effect of common chemical pinpointed

A common chemical found in household products could increase the risk of cancer by blocking the ability of cells to fix genetic flaws which lead to the disease.

UK researchers have identified how aldehydes may raise cancer risk by studying their actions in human cells in the lab. They found that cells from patients with a faulty copy of the BRCA2 breast cancer gene were particularly susceptible.

'Our study shows how chemicals to which we are increasingly exposed in our day-to-day lives may increase the risk of diseases like cancer,' said Professor Ashok Venkitaraman at the University of Cambridge, who led the study published in Cell.

'It also helps to explain why "the faults in our stars" - namely the faulty genes we are born with - could make some people particularly sensitive to the cancer-causing effects of these chemicals.'

Aldehydes are a class of chemicals found widely in the environment, from tobacco smoke and car emissions to shampoo and cosmetics. They can also accumulate in body tissues by certain processes, such as the breakdown of alcohol.

Exposure to aldehydes had been linked to cancer, but their mechanism of action was unknown.

Professor Venkitaraman's team found that aldehydes broke down the cell's natural defences that repair DNA damage which can lead to cancer. The environmental toxin had this effect in normal healthy cells, but its action was more pronounced in cells from individuals with just one faulty BRCA2 gene. In these people, the aldehydes break down BRCA2 protein levels below the amount required for adequate DNA repair, which could cause mutations and promote cancer formation.

'An important implication of our work is that it may be aldehyde exposure that triggers cancer susceptibility in people who inherit one faulty copy of the BRCA2 gene. This may help us in future to prevent or treat cancer in such people.'

Some experts were cautious about the study's findings. Professor Paul Pharoah also at the University of Cambridge, but who was not involved in the work, noted that the study says little about the importance of the risks of aldehyde exposure and cancer, adding: 'It is rather misleading to suggest that shampoo for example is an important cause of cancer in humans.'

He said that while the research helps in understanding the biology of cancer 'it has no immediate implications for the general public'.