Start Date: May 01, 2009
End Date: Apr 30, 2014
We will use both high fat diet-induced nonalcoholic steatohepatitis (NASH) rats and genetically-induced obese mice with injections of liver-specific carcinogen,diethylnitrosamine, followed by treatment with tomato extract or lycopene for both short and long durations. We will focus on the role of the stress-activated protein c-Jun-NH2-kinase (JNK) signaling, a key component mediating the high fat-induced oxidative stress and inflammatory processes, in response to tomato extract and lycopene supplementation on both cell proliferation/apoptosis, inflammation and premalignant and malignant lesions in obesity related hepatic tumorigenesis. Wewill complement animal study with cell culture studies (e.g., use siRNA silencing of JNK) using human hepatocyte lines and liver cancer cells to facilitate mechanistic studies to determine the contribution of the JNK signaling pathway to lycopene action. Since adiposity contributes to the increased incidence and/or death from liver cancer, we will examine metabolic alteration, including insulin resistance,and pro-inflammatory signaling in intra-abdominal fat tissue and its potential contribution to hepatic carcinogenesis. Once we establish that there is an association between metabolic alteration and hepatic carcinogenesis, we will examine insulin and insulin growth factors (IGF-I/IGF-II) signaling cascades and address their differential activation in NASH and its related hepatic carcinogenesis, as well as potential actions of tomato extract and lycopene prevention against the onset of high fat diet/obesity-related liver disease.