Chronic inflammation is a predisposing factor for colorectal cancer, which is the third leading cause of cancer-related deaths in the United States. Dr. Anna Means and colleagues reported in the journal Cell and Molecular Gastroenterology and Hepatology last month that they linked the inflammation-driven carcinogenesis of the colon to the loss of an important signaling protein called SMAD4. SMAD4 is part of the transforming growth factor β (TGF-β) signaling pathway, which regulates the immune and inflammatory response to infection in the colonic epithelium.
La délétion spécifique du gène SMAD4 dans les cellules épithéliales du côlon de souris normales cultivées in vivo a augmenté l'expression des médiateurs inflammatoires. Chez les souris adultes présentant une inflammation, l'absence de SMAD4 se traduit par une similitude surprenante entre les tumeurs et les cancers associés à la colite humaine.
Loss of SMAD4 was also observed in 48% of human colitis-related cancers, compared with 19% of scattered cancers colorectaux. “This loss may be an important factor from premalignant lesions to aggressive malignant tumors,” the researchers concluded. Therefore, friends with chronic inflammation must eliminate inflammation in time, and do not regret it until the inflammation develops into cancer.
