Liver cancer linked to obesity

Posted Jan 6, 2014 by Tim Sandle
Obesity increases the risk of contracting liver cancer. Obesity increases cellular stress in the liver and research indicates a direct biological link between cellular stress and the development of liver cancer.
Liver cancer or hepatic cancer, is a cancer that originates in the liver. Primary liver cancer is the fifth most frequently diagnosed cancer globally and the second leading cause of cancer death. Liver cancers are malignant tumors that grow on the surface or inside the liver. They are formed from either the liver itself or from structures within the liver, including blood vessels or the bile duct.
A research group has identified a molecular link between liver cancer, cellular stress, and these health problems that increase the risk of developing this cancer. The molecular link is a protein called CHOP, which had previously been thought to generally protect against cancer, actually promotes liver cancer in mice and may do the same in humans.
CHOP (CCAAT-enhancer-binding protein homologous protein) is a factor that is produced when cells experience certain kinds of stress. It is known to promote cell death, or apoptosis. The study shows that, despite its role in cell death, CHOP actually is elevated in liver tumor cells in mice. Furthermore, mice without CHOP are partially protected from liver cancer, developing fewer and smaller tumors than the normal mice in response to liver cancer-causing drugs.
What is thought to happen is that obesity, alcoholism, and viral hepatitis cause cellular stress and this induces expression of the CHOP protein. This suggests a biological pathway that links health problems to liver cancer.
The findings should direct an area of cancer research towards inhibiting the CHOP function.
The research was conducted at the University of Iowa and reported in PLOS Genetics. The paper is titled “The Stress-Regulated Transcription Factor CHOP Promotes Hepatic Inflammatory Gene Expression, Fibrosis, and Oncogenesis.”