The team based at the Cancer Research UK/MRC Gray Institute for Radiation Oncology and Biology at the University of Oxford carried out studies in samples of tumour cells and healthy cells. They screened 200 genes involved in DNA damage repair to identify potential new targets for drugs to improve radiotherapy effectiveness.
The scientists discovered that blocking the activity of a gene called POLQ – which is switched on in cancer cells – increased the ability of radiotherapy to destroy tumours.
This means the development of drugs to block POLQ would potentially increase the effectiveness of radiotherapy without increasing the side effects of the treatment.
One of the lead authors Dr Geoff Higgins, a Cancer Research UK scientist at the Gray Institute, said: “We’ve sieved through a vast pool of promising genetic information and identified a gene that could potentially be targeted by drugs to improve the effectiveness of radiotherapy.
“There are many different types of cancer and tumours can differ widely in the way they respond to radiotherapy – but the reasons for these differences are largely unknown. Our research identified a gene that enables tumour cells to survive radiotherapy. Blocking the activity of this gene resulted in a greater number of tumour cells dying after radiotherapy and provides new avenues for research.”
Radiotherapy is a key aspect of cancer care. Many thousands of cancer patients will have some form of radiotherapy as part of their treatment and it is estimated to contribute to 40 per cent of cases where cancer is eliminated.
The Cancer Research UK Gray Institute for Radiation Oncology Cancer Research in Oxford is the world’s largest and most comprehensive centre for research in radiation oncology. The centre is researching aspects of radiobiology that could yield new advances in radiation treatment of patients with cancer.
Professor Gillies McKenna, director of the institute, said: “The next stage is to translate this discovery into a treatment that will benefit patients. It is incredibly exciting to think that scientists may be able to develop something as simple as a pill to improve radiotherapy treatment and increase survival from a wide range of cancers.”
Dr Lesley Walker, director of cancer information at Cancer Research UK, said: “Radiotherapy is a really important tool in the box of treatments to beat cancer. Around four in ten people with cancer will have radiotherapy as part of their treatment which is why we are investing heavily in research into the most effective ways to deliver it.”
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Higgins, G. et al (2010). A Small Interfering RNA Screen of Genes Involved in DNA Repair Identifies Tumor-Specific Radiosensitization by POLQ Knockdown Cancer Research, 70 (7), 2984-2993 DOI: 10.1158/0008-5472.CAN-09-4040