Most recent update: Monday, October 22, 2018 - 14:53

Bariatric News - Cookies & privacy policy

You are here

Colon cancer and obesity

Study: obesity not diet causes colon for cancer

Identifying the signalling pathways and understanding how the signal is transduced may lead to treatments for colorectal cancer in obese patients

Obesity causes changes in the colon that may lead to colorectal cancer, according to a study in mice by the National Institutes of Health. The finding bolsters the recommendation that calorie control and frequent exercise are not only key to a healthy lifestyle, but a strategy to lower the risk for colon cancer.

A large body of scientific literature says people who are obese are predisposed to a number of cancers, particularly colorectal cancer, the researchers from the National Institute of Environmental Health Sciences (NIEHS) write in the journal Cell Metabolism.

To better understand the processes behind this link, the researchers fed two groups of mice a diet in which 60 percent of the calories came from lard. The first group of mice contained a human version of a gene called NAG-1, which has been shown to protect against colon cancer in other rodent studies. The second group lacked the NAG-1 gene.

The NAG-1 mice did not gain weight after eating the high-fat diet, while mice that lacked the NAG-1 gene grew plump.

"The obese mice exhibited molecular signals in their gut that led to the progression of cancer, but the NAG-1 mice didn't have those same indicators," said Dr Thomas Eling from the National Institute of Environmental Health Sciences (NIEHS).

The researchers looked for molecular clues, by isolating cells from the colons of the mice and analysing a group of proteins called histones. Histones package and organize DNA in a cell's nucleus, and sometimes undergo a process known as acetylation, in which chemical tags bind to their surface. The pattern of acetylation varies depending on the chemical processes taking place in the cell.

Wade explained that the acetylation patterns for the obese mice and the thin NAG-1 mice were drastically different. Patterns from the obese mice resembled those from mice with colorectal cancer. The additional weight they carried also seemed to activate more genes that are associated with colorectal cancer progression, suggesting the obese mice are predisposed to colon cancer.

"Any pre-existing colon lesions in these animals are more likely to evolve rapidly into malignant tumours," said co-researcher, Dr Paul Wade. "The same thing may happen in humans. Once we identify the signalling pathways and understand how the signal is transduced, we may be able to design ways to treat colorectal cancer in obese patients.”

Want more stories like this? Subscribe to Bariatric News!

Bariatric News
Keep up to date! Get the latest news in your inbox. NOTE: Bariatric News WILL NOT pass on your details to 3rd parties. However, you may receive ‘marketing emails’ sent by us on behalf of 3rd parties.