A study reported online in the journal Molecular Cancer Research concluded that patients experiencing physical or psychological stress including rigorous physical exercise a day or two before cancer treatment may activate a stress-sensitive protein that allows cancer cells to survive treatments including chemotherapy and radiation. This survival of cancer cells is related to the presence of heat shock factor-1 which has previously been linked to stress.
Carrying out a series of experiments using breast cancer cells the researchers found that a protein activated by the presence of heat shock factor-1 could block the process that kills cancer cells even after damage of cell DNA by radiation or chemotherapy. The heat shock factor-1 activated a specific protein (Hsp27) that helps the cancer cells survive. In all of their experiments the researchers saw that a heightened presence of Hsp27 protein was associated with a lowering of other proteins that facilitate cancer cell death. When they introduced siRNA, a molecule that assists in cancer cell destruction, the cell death mechanism was restored.
Although no drug currently exists the researchers believe that a drug with the same effect as the molecule siRNA, which is not suitable for patients, might stop the Hsp27 from preventing cancer cell deaths. More research in a clinical setting is needed to validate these findings.
