Although radiotherapy is an effective treatment for the disease, about a third of patients go on to experience a recurrence of their cancer.
Scientists funded by Yorkshire Cancer Research at the University of York have identified a population of radiation resistant prostate cancer cells, and by combining low doses of a common cancer drug with radiotherapy treatment they have increased the sensitivity of these cells to radiation. The findings could lead to a reduction in recurrences.
Professor Norman Maitland, Director of the YCR Cancer Research Unit in the Department of Biology at York, said: “There is a population of cells in every cancer that is highly resistant to radiotherapy. By identifying these cells, we have pin-pointed what we need to target.”
Dr Fiona Frame, a member of Professor Maitland’s team, began her study by taking tissue from prostate cancer patients undergoing surgery. She then divided the cancerous cells into three categories and tested them for their response to radiation. Results from the tests showed that rare stem cells, which act as a ‘silent root’ within the cancer, showed more resistance when compared to other cell types.
Dr Frame also found that the DNA inside these cells is more tightly wound than the rest of the tumour cells. This tightly wound DNA is known as heterochromatin and acts as a protective shield against radiation.
Following these tests, Dr Frame used a HDAC inhibitor – a drug which interferes with the development of heterochromatin and leads to a less tightly packed form of DNA – to treat these cells. This led to increased radiation-induced DNA damage and reduced stem cell survival.
Dr Frame said: “Looking to the future, novel cancer treatment strategies must become more targeted and will require specific combination therapies tailored to different cell types within individual tumour types.”
Professor Maitland and his team at the YCR Cancer Research Unit achieved international recognition in 2005 when they were the first to identify prostate cancer stem cells, which are believed to be the ‘root cause’ of prostate cancer. The team, now supported by a £2.15m award from Yorkshire Cancer Research, has since explored the exact molecular properties that allow these cells to spread, survive and resist aggressive treatments such as radiation and chemotherapy.
Notes to editors:
- The paper entitled ‘HDAC inhibitor confers radiosensitivity to prostate stem-like cells’ (BJC.2013.691 / 4322-13TH) is here www.nature.com/bjc/journal/vaop/ncurrent/index.html
- Harrogate-based Yorkshire Cancer Research is the UK’s largest regional medical research charity (registered charity no. 516898). It exists to help the people of Yorkshire avoid, survive and cope with cancer by funding world-class research into its causes, diagnosis and treatment. It works in partnership with 200 plus scientists and clinicians to develop expertise and talent within Yorkshire.For further information, please visit www.yorkshirecancerresearch.org.uk or follow us on Facebook or Twitter.
- For more information about the YCR Cancer Research Unit in the Department of Biology at the University of York, please visit www.york.ac.uk/biology/units/cru/welcome.html
- The British Journal of Cancer is owned by Cancer Research UK. Its mission is to encourage communication of the very best cancer research from laboratories and clinics in all countries. Broad coverage, its editorial independence and consistent high standards have made BJC one of the world’s premier general cancer journals. www.bjcancer.com