Combining two unrelated treatment technologies might sound strange – but it provides a crucial step towards more effective targeted cancer therapies.
A new cancer treatment, emerging from a collaboration between the Department of Engineering Science and the Department of Oncology, demonstrates that two heads are often better than one – and the results may soon be saving lives.
A breakthrough in virotherapy, masterminded by Professor Len Seymour and Dr Miriam Bazan-Peregrino in the Department of Oncology, has produced a family of self-replicating viruses that kill cancer cells by sensing mutations. When they meet a cancerous cell, they infect it, and then move on to similar neighbouring cells a chain reaction that sees cancer cells die and normal cells survive. But reaching cancerous cells far from blood vessels is challenging, and requires high concentrations of locally delivered drugs.
In the Department of Engineering Science, researchers led by Professor Constantin Coussios use ultrasound to provide targeted drug delivery. Delivering bursts of high-intensity, focused ultrasound, they create microscopic bubbles in human tissue that expand and contract. When those oscillations are sufficiently large, they can push drug molecules towards a target without damaging cells. The technique can enhance the delivery of conventional drugs, but limited increases in local drug concentration mean that the improvements are small.
In 2008, however, Professors Seymour and Coussios found themselves in new laboratories at the Old Road Campus in Headington, a centre which encourages collaboration between engineering and clinical medicine. Virotherapy needed a technology to enhance distribution in tumours; drug delivery by ultrasound required a self-amplifying agent to realise its potential. The result is a synthesis of two ideas, producing a potent, non-invasive cancer treatment that is extremely well targeted.
When the virus is injected it causes no harm to healthy cells, but when ultrasound is applied, the virus can be driven into cancerous regions. In preclinical trials on human breast cancer tumours, the results are remarkable: the treatment is up to 50 times more effective than injecting the virus alone, and every experiment has shown at least a five-times increase in cancer cell death. What is more, there is no observable damage to surrounding tissue. The next step is to initiate the first clinical trials of ultrasound-enhanced drug delivery, which the researchers hope will commence in 2012. The project demonstrates the power of collaborative work at the University of Oxford: two heads, and two therapies, are often better than one.
Funded by: The Engineering and Physical Sciences Research Council, Wellcome Trust, Breast Cancer Campaign, and Bellhouse Foundation.