From Garry Marley, Stillwater, Oklahoma, US
As your dispatch rightly stated, chemically converting cancer cells to benign ones mimics the process of embryogenic differentiation in which myriad cell divisions, beginning with the fertilised egg, yield populations of newly specialised cells with curtailed growth rates. Those cells form our tissues and organs. This is, in fact, an “epigenetic” process in which external chemical signals in the environment control which genes are expressed or repressed.
Because cancer is actually a heterogeneous family of malignancies, identifying these in vivo epigenetic signals has proved to be a daunting task. Paediatric tumours, however, present the greatest chance of success, since they may well be the earliest consequence of embryos that failed to encounter their epigenetic signals.
