MILLIONS of cancer sufferers were given new hope last night after scientists said they have uncovered a new way of killing tumours.
The breakthrough not only sheds light on why some people fail to respond to chemotherapy, it also reveals a new way of targeting cancer cells. Until recently, it was thought cells could only die through a process called apoptosis.
Because apoptosis is often blocked by cancer cells, drugs frequently do not work which allows the tumour to grow and spread.
Now, in an important step, the findings from the Breakthrough Breast Cancer Research Centre at The Institute of Cancer Research (ICR) in London reveal a new process in which cells can die called necroptosis.
They found that some chemotherapy drugs can be killed through this previously-unknown path, according to the study published online in the Molecular Cell journal.
And more importantly, they found in the laboratory it was possible to actually activate a set of proteins which then push cancer cells into this form of cell death.
This raises the hope of new targeted treatments that could also kill tumour cells which have proved resistant to apoptosis.
Study author Professor Pascal Meier, from the Breakthrough Breast Cancer Research Centre at the ICR, said: “These findings represent a new line of attack in the fight against cancer. Chemotherapy has been around for decades but we have never understood how it kills cancer cells. This work shows not only that it can happen by two different processes, but how drugs can be developed to activate this newly discovered second cell-killing process in a much smarter, more effective way.
“We are at an early stage with this work but it could represent a new way of thinking about how we treat cancer patients in the future.”
They wanted to know how a class of chemotherapy drugs called topoisomerase inhibitors kill cancer cells.
The team identified for the first time how a number of key proteins involved in this process work together to kill cancer cells.
They discovered that the proteins, could be switched on to effectively kill cancer cells. Because this cell-killing action is much more prominent in cancer than normal cells, it means these proteins could make an excellent target for new, more effective, targeted treatments, with fewer side-effects for patients.
It also means that patients whose tumours lack any of these proteins should not be treated with certain chemotherapeutic drugs.
A drug which targets one of the proteins, called SMAC-mimetics, is already showing promise in clinical trials. These results add further weight to the argument that these could be an effective cancer treatment for some patients.
Dr Julia Wilson, from Breakthrough Breast Cancer, said: “It is a major advance in our understanding of how cancer cells work and how we can combat the disease. It suggests we can use chemotherapy more intelligently and develop treatments which more precisely exploit this newfound weakness for the benefit of patients.”