Chapter 107 - Azoxymethane-induced Colon Carcinogenesis through Wnt/beta-catenin Signaling and the Effects of Olive Oil

Abstract

Colon cancer is one of the leading causes of cancer death in both men and women in Western countries, and in recent years, it has increasingly become a major cause of cancer mortality in Oriental countries, including Japan. These changes are associated with the westernization of Japanese dietary habits, which involves high consumption of meat and fat, together with low consumption of fruit, vegetables, vitamins and fibers, compared with classical Japanese diets. In fact, many epidemiological studies have shown a positive relationship between dietary fat consumption and colorectal cancer. Cancer results from the accumulation of multiple independent genetic alterations. In colon cancer, these genetic changes affect colon epithelial cell proliferation, differentiation and apoptosis. In familial adenomatous polyposis (FAP), which is one of the hereditary forms of colon cancer, a gene has been identified and its protein is a key molecule in the Wnt signaling pathway. Many experiments have shown that the Wnt signaling pathway plays a crucial role in the etiology of colon cancer, including hereditary and sporadic forms. This chapter focuses on dysregulation of colonic mucosal homeostasis in carcinogen-induced colon cancer models and the effects of dietary fatty acid.