Apoptosis - Programmed Cell Death
Our cells are programmed to self-distruct when things go wrong. The failure of this process contributes to cancer growth.C. Norman Coleman, MD
Director, Radiation Oncology Sciences Program
National Cancer Institute
Robert Weinberg, PhD
Daniel K. Ludwig Professor for Cancer Research
Massachusetts Institute of Technology
NORMAN COLEMAN, MD
Apoptosis is programmed cell death. So all cells have built within them the ability to commit suicide. When they're no longer needed, there is a mechanism that very orderly disposes of that cell. So cancer cells--one of the fundamental processes of cancer is probably the loss of this programmed cell death.
And this is a process that was only really discovered 10 years ago. It was, it was funny: People used to look at them in the microscope and they saw these cells that they used to call "pyknotic" - dying cells - no one had any idea what it was. Then someone realized these were all there on purpose; I mean, the body had a whole set of functions to delete cells. When you discover it, you say, "Well, of course, it makes total sense."
ROBERT WEINBERG, PhD
In the normal body tissues are continually eliminating cells which have in one way or another outworn their usefulness, become defective, become damaged, and this elimination occurs through a process referred to as apoptosis in which individual cells are induced to activate their own internal hard wire suicide program. It's often called programmed cell death. And we now realize that one of the ways through which the body protects itself against cancer is to induce would be cancer cells to kill themselves, to activate their own internal apoptotic programs. In fact, in order for a cancer cell to be truly successful it must find ways of evading its own suicide programs, and therefore one of the things that cancer cells learn how to do on the long road to becoming entirely malignant is to turn of their internal suicide programs so that even though they may receive signals from the outside which would induce them to initiate their suicide programs, they would remain resistant to such suicide programs because they have been inactivated inside the cancer cells.