How obesity might lead to cancer

Cancer is caused by genetic changes that break down normal constraints on cell growth. It is known that obesity and overweight increases the risk of developing cancer, but the question until now has been why? Now, researchers have demonstrated that lipids associated with obesity make cancer cells more aggressive and likely to form actual tumors.

The researchers have discovered that the changed environment surrounding the cancerous cell, from a normal weight body to an overweight or obese body, pushes the cancer cell to adapt.

The cellular adaptation to obesity is governed by palmitic acid (PA) and leads to enhanced tumor formation capacity of breast cancer cells. This process is governed epigenetically through increased chromatin occupancy of the transcription factor CCAAT/enhancer-binding protein beta (C/EBPB).

Obesity-induced epigenetic activation of C/EBPB regulates cancer stem-like properties by modulating the expression of key downstream regulators including CLDN1 and LCN2.

“This means that even in the absence of new gene mutations, obesity increases the risk that tumors will form”, says the senior author.

Obesity is the cause of approximately 500 000 new cancer cases each year – a number that is expected to grow as obesity rates continues to increase.

“To scientifically dissect how these two complicated diseases interact has been extremely interesting and rewarding. Especially as this new understanding will enable researchers to design improved treatments for obese cancer patients”, the author adds.