Impact of PCBs, Furan and Dioxin on Hepatocarcinogenesis

Stockholm Convention defined polychlorinated biphenyls (PCBs) as a group of persistent organic pollutants (POPs) such as dioxin/furan, dichlorodiphenyltrichloroethane, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, aldrin, polychlorinated dibenzofurans and organometallic compounds (such as organotin and organomercury) which share the same characteristics of being persistent, bioaccumulative and toxic and can travel long distance through various media. They have diverse health impacts with different underlined molecular mechanisms. Recently, PCBs were referred as potent carcinogens with persistent existence in the environment. As the liver is the organ of detoxification, it is the major target organ for toxic effects induced by environmental contaminants, including PCBs. PCBs, furan and dioxin exert their hepatocarcinogenic effect through different mechanisms such as induction of oxidative stress, an increase of reactive oxygen species (ROS), mutagenic induction to oncogenes and epigenetic alteration to hepatic cells. In this chapter, we will provide an updated overview about PCBs, furan and dioxins, their impact on liver cancer initiation and progression on various in vivo and in vitro systems and its underlined molecular mechanisms. Also, a special emphasis will be directed to highlight zebrafish as in vivo model system to analyse the hepatocarcinogenic effect of these pollutants.