Scientists activate cancer cell suicide

In collaboration with the Press Association

Scientists have discovered a way to trick cancer cells into committing suicide, according to University of Illinois research.

Normally, cells at the end of their lives, die naturally by 'committing suicide', a process known as apoptosis. But cancer cells can bypass this process and carry on multiplying indefinitely.

To reverse this, researchers screened 20,000 synthetic compounds to find the trigger for the protein which causes cells to kill themselves.

Cell death occurs when a protein known as procaspase-3 is converted into another called caspace-3, which triggers apoptosis.

Using a synthetic compound known as PAC-1 they were able to activate procaspase-3 in cancer cells grown in the laboratory and in mouse models, causing apoptosis.

"By bypassing the broken pathway, we can use the cells' own machinery to destroy themselves," said researcher Professor Paul Hergenrother.

"This is the first in what could be a host of organic compounds with the ability to directly activate executioner enzymes," he added.

The treatment's effect was shown to be related to the amount of procaspase-3 found in cancer cells, allowing scientists to judge whether it was likely to work in particular cases.

"The potential effectiveness of compounds such as PAC-1 could be predicted in advance, and patients could be selected for treatment based on the amount of procaspase-3 found in their tumour cells," noted Professor Hergenrother.

Cancer Research UK's Dr Michael Olson, based at the Beatson Institute for Cancer Research in Glasgow, said: "These findings present an exciting new therapeutic strategy for the treatment of some cancers.

"It remains to be seen which, if any tumour types consistently express elevated procaspase 3. That will tell us how many patients could potentially benefit from the drug.

"Clinical trials will be needed to confirm whether procaspase 3 causes any adverse effects in humans."

The study is published in the journal Nature Chemical Biology.