RT Book, Section
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.
SR Print(0)
ID 1145755393
T1 Cancer Epigenetics
T2 Textbook of Complex General Surgical Oncology
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9780071793315
LK accesssurgery.mhmedical.com/content.aspx?aid=1145755393
RD 2024/04/24
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.