Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/9/2011
Publication Date: 7/11/2011
Citation: Tang, F., Pai, M., Wang, X. 2011. Consumption of lycopene inhibits the growth and progression of colon cancer in a mouse xenograft model. Journal of Agricultural and Food Chemistry. 59(16):9011-9021. Interpretive Summary: It has been shown that lycopene from tomato and tomato products prevents the growth of human colon cancer cells in cell culture studies. However, the anticancer effects of lycopene against colon cancer has not been demonstrated in the human body. We demonstrated that lycopene supplementation significantly suppressed the growth of the colon cancer and its related biomarkers in the animal models of the disease. These results suggested that lycopene could act as a chemopreventive agent against the growth and progression of colorectal cancer.
Technical Abstract: A previous study indicated that lycopene could significantly inhibit the proliferation of human colon cancer cells in vitro. However, the in vivo anticancer effects of lycopene against colon cancer have not been demonstrated yet. Therefore, this study investigated whether consumption of lycopene could prevent the growth and progression of colorectal tumor in a mouse xenograft model. Bioluminescence imaging, histopathological, immunofluorescence (IFC), and immunohistochemical (IHC) staining results indicated that lycopene could effectively suppress the growth and progression of colon cancer in tumor-bearing mice. The results demonstrated that lycopene significantly suppressed the nuclear expression of PCNA and ß-catenin proteins in tumor tissues. Consumption of lycopene could also augment the E-cadherin adherent molecule and nuclear levels of cell cycle inhibitor p21CIP1/WAF1 protein. The chemopreventive effects of lycopene were associated with suppression of COX-2, PGE2, and phosphorylated ERK1/2 proteins. Furthermore, the inhibitory effects of lycopene were inversely correlated with the plasma levels of matrix metalloproteinase 9 (MMP-9) in tumor-bearing mice. These results suggested that lycopene could act as a chemopreventive agent against the growth and progression of colorectal cancer in a mouse xenograft model.