Common Chemical May Increase Cancer Risk

Aldehydes—found in cars, smoke, building material, cosmetics, and shampoos—may degrade anti-cancer mechanisms in cells.

Chemicals are found in everything from cleaning products to food. While it may be perceived that certain chemicals are not harmful, results from a study published by Cell suggests that exposure to aldehydes may be carcinogenic.

Aldehyes are a common type of chemical found in cars, smoke, building material, cosmetics, and shampoos. Exposure to these chemicals has been associated with an increased risk of cancer, but the underlying cause was unclear.

The authors of the study found these chemicals potentially increase the risk of cancer since they are able to break down the repair capabilities of cells.

The authors used human cells and cells from patients with a BRCA2 mutation to determine how aldehyde exposure may drive cancer.

While damage to DNA can occur naturally as cells divide, this can promote cancer; however, the body has a safeguard that helps repair the damage to prevent disease.

The authors discovered that aldehyde exposure can break down this mechanism in healthy cells, but patients with a mutated copy of BRCA2 are especially sensitive to the damage, according to the study.

Despite being born with 2 copies of the gene, patients with mutated BRCA2 have a greater likelihood of developing cancer. Since the cells should be able to repair DNA with the normal copy of the gene, it is unclear why these patients have an increased risk of cancer.

Results from the new study suggest that aldehydes may degrade BRCA2 protein in cells, which is used to repair DNA. For patients with 1 faulty copy of the gene, exposure to adlehydes may reduce BRCA2 protein levels below that required for adequate DNA repair, according to the study.

This process can lead to an increased risk of cancer formation, as the mechanisms to prevent mutations are no longer intact.

Approximately 1 in 100 individuals carry a faulty BRCA2 gene, which puts them at a higher risk of developing breast, ovarian, prostate, and pancreatic cancers, according to the study. Aldehyde exposure may further increase the risk of cancer among these populations.

“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 researcher Ashok Venkitaraman, PhD. “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 also commonly found in alcohol. When humans drink alcohol, the body converts it into acetaldehyde, which is broken down by the acetaldehyde dehydrogenase enzyme. Millions of individuals have a faulty ALDH2 gene, which inactivates the enzyme and may also increase cancer risk, according to the study.

The authors concluded that aldehyde accumulation in patients could trigger cancer promotion by degrading BRCA2.

“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,” Dr Venkitaraman said. “This may help us in future to prevent or treat cancer in such people.”