SCIENTISTS AT Trinity College Dublin (TCD) have revealed a second, hidden role played by a substance inside living cells, something that has the potential to improve cancer treatments.
Its discovery, published in the current issue of the journal Molecular Cell could open up new ways to attack cancer cells and throw them into a natural and spontaneous process known as cell suicide.
The work, led by Smurfit Professor of Medical Genetics Prof Séamus Martin, focuses on a family of genes and the proteins that they produce, collectively known as the Bcl-2 family.
Bcl-2 is important because it is known to help cancer cells develop resistance to chemotherapy treatments. Deeper study by Prof Martin and his team including Clare Sheridan, Petrina Delivant and Seán Cullen uncovered a second, previously unknown function for Bcl-2.
The protein also supports the division of mitochondria, tiny powerhouses inside the cell that provide all the energy the cell needs to function. This role occurs in normal cells and is an everyday part of supporting the mitochondria within cells. "This may be like a day job in normal, healthy cells," he said. While this is desirable in healthy cells, Bcl-2's involvement in blocking the breakdown of mitochondria inside cells that have gone cancerous interferes with apoptosis and allows the aberrant cell to avoid natural cell death.
The discovery opens up important potential for new research and possible new treatments, Prof Martin believes. Pharmaceutical companies are already attempting to develop drugs that block the action of Bcl-2 in apoptosis, but these may also interfere in Bcl-2's benign role with mitochondria. Avoiding this could help companies find drugs that cause fewer negative side-effects.
A better understanding of Bcl-2 may also throw up new ways to inhibit it, thus reducing resistance to chemotherapy. "This is really just the beginning," Prof Martin said. It represented an important step in understanding how apoptosis was regulated and how to manipulate the cell death machinery already within the cell to control cancers.
Funding for the work comes from Science Foundation Ireland.
