Apoptosis Insight Reveals Cancer Clue

Researchers from the UK's Imperial Cancer Research Fund have revealed new aspects of programmed cell death, or apoptosis, which lend further weight to the importance of this process in the development of cancer and other diseases. The findings are published in the current issue of the European Molecular Biology Organization journal.

One line of thought on the nature of apoptosis which is currently popular suggests that every time a cell receives a signal instructing it to divide, it also receives a signal telling it to undergo programmed cell death (see diagram). This second signal is thought to be overcome by a second, independent signal to preserve the cell intact. Now, Gerard Evan and his colleagues at the ICRF have demonstrated this concept experimentally.

Their work centers on a gene known as c-myc, which is mutated in many types of tumor. It is thought that in the normal state, this gene is induced by growth factor stimulation and initiates cell division, and when growth factor levels decline the gene "switches off." Dr Evan's team has now proved that the gene will also set off the suicide program unless its function is dampened by extracellular factors.