New prostate cancers drugs may be missing the tumor's root cause

New prostate cancers drugs may be missing the tumor's root cause

26/1/2014

Some of the latest prostate cancer drugs target a type of cells which may not be driving the tumor's growth, as previously thought.

Scientists at the University of York have discovered that a process previously thought to drive the development of cancer occurs in cells that are already cancerous. The findings mean therapies aimed at reversing this process might not be effective against cancer stem cells, allowing the cancer to return. This process is called 'methylation'.

The work, carried out by Dr Davide Pellacani, a member of Professor Norman Maitland's team at the YCR Cancer Research Unit at the University's Department of Biology, and funded by Yorkshire Cancer Research and the Grand Masonic Charity, reveals a major difference between the cells normally treated in cancer and the underlying 'stem' cells.

Dr Pellacani said: "To develop cancer, certain proteins found in healthy cells need to be switched off. Sometimes this is caused by methylation, a process where DNA is changed to block instructions for making a specific protein.

"There are obvious differences in the methylation of genes in prostate cancer cells and non-cancer cells. This previously suggested that the process could be driving the progression of cancer, and that this could be reversed by using specific drugs, but our research has suggested that this may not be the case."

Prostate cancer is made up of two types of cell; rare basal cells, including stem cells, from which the tumor is formed, and luminal cells, which form the tumor mass.

The team found that a change from basal to luminal cells (a process called differentiation) is strongly linked to the methylation difference, suggesting that the methylation in prostate cancer cells is not the primary driving force for the cancer.

Dr Pellacani continued: "There are clear implications for the effectiveness of new drugs currently being developed to change the methylation pattern in cancers. At the moment we only treat a proportion of the cells. By breaking the cancer down into its component cell types, we get insights into why cancers come back after treatment. Only by treating all the cells in a cancer will we approach long term treatment or even cure."

 

Source: Science Daily: http://www.sciencedaily.com/releases/2014/01/140124110720.htm