Computational studies of therapeutic virus behaviour in tumours could lead to more effective cancer treatments, say US scientists. 

Using viruses to treat cancer might seem unorthodox but recent research has shown it can be effective. Some viruses use some of the same replication processes as cancer cells and so can easily hijack the cells and stop the tumour growing. Also, as the virus is generated directly inside the cancer cells the amount of therapeutic agent increases specifically at the tumour site. 

However, understanding how these viruses spread is very difficult, says David Dingli at the Mayo Clinc, Rochester, US, as it involves complex interactions between the virus, the tumour and the host. Some tumours are eliminated consistently, while others persist despite evidence of ongoing virus reproduction, he explains. Now, he and his team have devised a computer model to explore exactly how anti-cancer viruses spread in tumours of different shapes and sizes. 

The models indicate that anti-cancer viruses are more effective at treating small compact tumours, says Dingli, which suggests that using chemotherapy to reduce the bulk of the cancer followed by viral therapy may offer a superior outcome. 

John Yin, an expert in virus-host interactions at the University of Wisconsin-Madison, USA says , 'this work is useful in highlighting tradeoffs that may arise in the design and implementation of virus-based anti-tumour strategies. While it is desirable that therapeutic viruses reproduce within the tumour, spread to and kill all cells of the tumour, this work shows how these features need to be balanced.' 

Surprisingly, Dingli's team also discovered that viruses that kill cancer cells slowly are likely to be more effective than those that kill cells quickly. 'In some instances, viruses that are too potent at killing cells may burn out,' comments Yin. 

Dingli says his team are now 'planning in vivo studies to test the model using viruses that can be tracked non-invasively.' 

David Sharpe 

Enjoy this story? Spread the word using the 'tools' menu on the left or add a comment to the Chemistry World blog.