Prostate cancer kills 10,000 men a year in the UK

Blocking a gene called IGF1R can make prostate cancer cells more sensitive to radiotherapy and certain kinds of chemotherapy, Cancer Research UK found.

Prostate cancer, which kills 10,000 men in the UK each year and is the second highest cause of cancer deaths among men, is notoriously difficult to treat.

Using new technology, RNA interference, the team are able to switch off a single one of a cell's 35,000 genes.

RNAi uses small molecules to 'stand in the way' of specific genes to stop them working.

Cancer scientists use the technique to disable genes that have ceased working properly and are causing or sustaining cancer.

Dr Val Macaulay, Cancer Research UK's senior clinical research fellow at the Weatherall Institute of Molecular Medicine in Oxford, said: "One of the most effective ways of treating prostate cancer is to starve it of hormones that feed it in its early stages.

Resistant

"But at some point these cancers always become hormone independent and this form of treatment ceases to work.

"Prostate cancer is also resistant to most chemotherapy drugs so there is an urgent need for new ways to tackle the disease."

Switching off IGF1R in a selection of prostate cancer cells resistant to different treatments made the cells two times as sensitive to radiotherapy.

This is early stage research, but holds great promise in the fight against not only prostate cancer but other forms of the disease Professor Robert Souhami, of Cancer Research UK

The team, jointly funded by Cancer Research UK and the Health Foundation, also found blocking the gene enhanced the effect of chemotherapy on hormone-independent prostate cancer cells.

The technique made the cells significantly more sensitive to chemotherapy drugs that kill cells by damaging their DNA but it did not enhance the effect of chemotherapy drugs that kill without causing DNA damage.

Dr Macaulay said she was excited by the prospect of treating patients using the new technology.

"These results suggest that IGF1R plays a role in the cell's response to DNA damage, and will tell doctors which type of chemotherapy drugs are likely to be enhanced by treatments targeting the gene.

"This is the first study to show that silencing the IGF1R gene can improve the effectiveness of treatments for prostate cancer."

Professor Robert Souhami, director of policy and communication at Cancer Research UK, said: "IGF1R sustains many types of cancer cell, so blocking the gene could prove a powerful new way of treating tumours.

"This is early stage research, but holds great promise in the fight against not only prostate cancer but other forms of the disease."

And Chris Hiley, head of policy and research at The Prostate Cancer Charity, added: "We welcome this step forward in laboratory science.