Brussels, 02 Aug 2006
A team from the Uppsala Branch of the global Ludwig Institute for Cancer Research (LICR) has identified a novel approach for targeting cancerous cells analogous to the effects of antibiotics on bacteria - to attack the cell walls.
The team has found specific pathways that control the building of cell walls. Cells stripped of their walls are simply not viable, and so the discovery could be a powerful tool in the fight against tumour growth.
The team found a particular lipid - a building block of the cell wall - which could be regulated easily, and could be an important regulator of cell growth. 'New cells are created by the duplication of existing cells through a highly-organised process known as the cell cycle,' explains lead author Dr Maite Bengoechea Alonso. 'Last year we discovered that a protein called SREBP1 that regulates the synthesis of lipids needed for new cell walls was regulated during the cell cycle. Now we show that the SREBP1 protein actually controls the cell cycle.'
The effect was more powerful than the team had expected - the SREBP1 protein appears to be integral to cell wall formation, and, 'In fact, we literally stopped the cell cycle in its tracks by removing SREBP1 from cells. It seems that if you don't have SREBP1 activity, you can't make lipids, and if you don't have lipids, you can't make new cells,' said senior author Dr Johan Ericsson.
While a little more complicated, the pathways could give researchers the chance to develop 'cancer antibiotics'. 'I think that the effects that some antibiotics have on bacteria is a good metaphor for what we would like to do. Some antibiotics, including penicillin and penicillin derivatives, prevent the bacterial cell wall from forming properly, and without a cell wall the bacteria fall apart and die. It is possible to specifically target the synthesis of the bacterial cell wall because it is different than the walls around human cells,' Dr Ericsson told CORDIS News.
The application for this discovery is extremely important - cancers are cells that divide, grow and multiply abnormally. This protein target could be a way of checking that growth. 'Cancer cells divide uncontrollably, so their need for lipids is more urgent and continuous than normal cells. Treatment with an inhibitor of SREBP1 might reduce the rate of cancer cell proliferation to slow down tumour growth, or might enhance the effect of targeted therapies that aim to actually kill cancer cells,' said Dr Ericsson.