TY - CHAP M1 - Book, Section TI - Cancer Epigenetics A1 - Brock, Malcolm A1 - Wrangle, John A2 - Morita, Shane Y. A2 - Balch, Charles M. A2 - Klimberg, V. Suzanne A2 - Pawlik, Timothy M. A2 - Posner, Mitchell C. A2 - Tanabe, Kenneth K. Y1 - 2018 N1 - T2 - Textbook of Complex General Surgical Oncology AB - Conrad Hal Waddington is usually credited with modifying the Greek word “epigenesis,” which described a theory of development, into a new term “epigenetics” to mean “the causal interactions between genes and their products which bring the phenotype into being.”1 Waddington described an “epigenetic landscape” usually as a system of bifurcating valleys through which a cell, depicted alternatively as water or a roulette ball, flows or rolls toward the sea constantly making binary choices on its way.2 Waddington explained how genes were responsible for creating this “epigenetic landscape” of valleys since these genes were positioned on the underside of the landscape and attached to it by a series of “guy ropes” much like how pegs with ropes determine the shape of a tent's canopy. Thus, genes were ultimately responsible for the motley array of crevices, valleys, and hills in the canopy through which a ball could follow downhill as it embarked on its developmental pathway of differentiation. In addition to Waddington, other leading biologists of the time, including Ernest Hadorn, Richard Goldschmidt, and Julian Huxley, also saw a relationship between genes and their action to development during a period when embryology and developmental biology were very disparate disciplines.4 Thus, the term “epigenetics” proved durable not only because it provided a convenient explanation of how expressed genes informed developmental decisions of a cell, but also because it brought together the two disciplines of Mendelian genetics and embryology. In time, epigenetics has become used not only to explain heritable changes in development, but also to understand diverse biological processes including normal aging, maternal X chromosome inactivation, as well as pathological states, such as cancer and neurodegenerative diseases. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/10/13 UR - hemonc.mhmedical.com/content.aspx?aid=1145755393 ER -