ABSTRACT
Background Obesity, a major public health concern, increases the risk of developing liver cancer which is the leading cause of cancer-related deaths worldwide. Obesity is associated with increased adiposity and macrophage infiltration both of which promote secretion of adipokines and cytokines in the tumor microenvironment. Specifically, visfatin and resistin have been detected at higher levels in the serum of obese individuals and liver tumors. However, the contribution of these adipocytokines in the progression of liver cancer remains unclear. Materials and methods The objective of this study was to characterize the effects of visfatin and resistin on HepG2, SNU-449 and HuH7 liver cancer cells. Cells exposed to visfatin and resistin were analyzed for fatty acid synthase protein, and phosphorylation of Akt and ERK tumorigenic signaling pathways, cell viability, lipogenesis, reactive oxygen species (ROS), matrix metallopeptidase 9 (MMP-9) enzyme activity and invasion. Results HepG2, SNU-449, and HuH7 liver cancer cells treated with visfatin and resistin increased cell viability, invasion, FASN protein, and Akt and ERK phosphorylation. Visfatin and resistin selectively increased ROS production in HepG2 and SNU-449 cells while there was no statistical difference in HuH7 cells. Visfatin and resistin stimulated lipogenesis in HepG2 cells while visfatin increased lipogenesis in SNU-449 cells, and visfatin nor resistin had an effect on lipogenesis in HuH7 cells. Lastly, visfatin and resistin increased MMP-9 enzyme activity in HepG2 and HuH-7 cells but only visfatin increased MMP-9 activity in SNU-449 cells. Conclusions Future studies are needed to determine if inhibition of ERK and Akt suppresses the visfatin and resistin-induced invasive liver cancer phenotype.
