Epigenetic Regulation in Cancer Metastasis

It is increasingly realized that there is a critical need for understanding the process of cancer, especially the most malignant form of the cancer, its distant metastasis, in order for the development of the ultimate cure for this deadly disease. To date, metastatic forms of cancers remain the deadliest of all. As the war against cancer marches on, along comes the understanding of the complexity of the problem. Metastasis of cancer, the distant establishment of growth, is the result of a series of longitudinal and progressive developments that stems from the primary tumor site, flows through body circulation, affects multiple organs and tissues, and eventually establishes itself at the distant target site(s). The process, termed metastatic cascade, involves cross talks of primary tumor cells with the primary tissue microenvironment, surviving circulating cells with immune systems, and invading tumor cells with endothelial cells in the target tissue microenvironment. It is also our current understanding that a multitude of interactions among numerous signaling pathways, signaling molecules, and structural entities are involved in the process of metastasis. Gradually research is linking various phenotypes of metastasis to the fundamental mechanisms involved in epigenome modulations. This chapter focuses on summarizing the advancement in the research that illustrates epigenetic regulations in critical steps during metastasis that lead to the final stage of cancer progression, in an attempt to lead the field to potential solutions in cancer treatment and therapeutics that may be better approached by dealing with epigenetic mechanisms.