title: Obesity-induced metabolic stresses in breast and colon cancer.
abstract: Epidemiological studies have suggested that excess body weight gain may be a major risk factor for colon and breast cancer. A positive energy balance creates metabolic stresses, including the excess production of reactive oxygen species (ROS), hyperinsulinemia, the elevated adipokine secretion, and increased gut permeability. Obesity is a risk factor for breast cancer in postmenopausal women, and overweight women are more likely to have poor outcomes. The higher circulating concentration of insulin-like growth factor 1 (IGF-1) in overweight and obese women is thought to be an important mediator to promote cell proliferation and survival via the activation of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK)/p38 signaling pathways. In an animal model of colon carcinogenesis, overweight mice fed a high-fat diet exhibited a greater number of colon tumors than lean animals. The increased abdominal fat was associated with higher concentrations of leptin, insulin, and IGF-1, which possibly mediate tumor growth. These data suggest that the metabolic burden created by excess adiposity accelerates uncontrolled cell growth and survival, thereby increasing the risk of developing breast and colon cancer.
authors.affiliation: Department of Food and Nutrition, Sookmyung Women's University, Seoul, Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Sung
authors.forename: Jee-Young
authors.initials: JY
authors.lastname: Yeon
authors.forename: Shin-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Jung Han Yoon
authors.initials: JH
authors.lastname: Park
authors.forename: Myung-Sook
authors.initials: MS
authors.lastname: Choi
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000378:metabolism*; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism; D015398:Signal Transduction; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D007334:Insulin-Like Growth Factor I; D058539:Phosphatidylinositol 3-Kinase; D048051:p38 Mitogen-Activated Protein Kinases