Research seeks new weapons against cancer

EMBARGOED – Wednesday 20 July 2011 Media Release

Research seeks new weapons against cancer with a super-sensitive urine test and new drugs lethal only to cancer cells

New Zealand researchers are developing a new test for prostate and bladder cancer that is so sensitive, it can detect just a single cancer cell that is washed out in the urine. The advent of new technology has made it possible to improve on the accuracy of an existing screening test, which the same team has already brought to the market.

The key to curing cancer is early detection, as most tumours have begun to spread by the time obvious symptoms are noticed. It is vital to have methods that can be used to screen high-risk groups before symptoms appear. The Health Research Council of New Zealand (HRC) has supported the development of both tests. The HRC Chief Executive, Dr Robin Olds, says: “Cancers of the bladder and prostate are very treatable if detected early. A highly accurate, non-invasive screening test like this will undoubtedly prevent some needless deaths.”

The research team is led by Professor Parry Guilford from the University of Otago, Dunedin. The HRC has also funded Professor Guilford to continue his work on drugs that are selectively lethal to cancer cells. Healthy cells produce E-cadherin, a protein that suppresses tumour growth, but the gene that produces E-cadherin is often ‘switched off’ in cancer cells. Professor Guilford and his team are searching for compounds that will destroy cells lacking E-cadherin, but not healthy cells with normal levels of the protein.

Improving drugs to better target and destroy cancer cells is also the focus of research by Associate Professor Robert Anderson and his team at the Auckland Cancer Society Research Centre at The University of Auckland. Cancer cells often grow into areas without blood supply, and are therefore starved of oxygen - an important difference between tumours and healthy tissues that scientists have worked hard to exploit. One strategy has been to develop drugs that produce toxic compounds only in cells with low levels of oxygen. An important problem, however, is getting the drug to penetrate the cells sufficiently to work. Professor Anderson and his team have taken an existing drug, improved its ability to penetrate cancer cells and modified it to produce only the most potent toxic free radicals that damage cancer DNA. They must now test the effectiveness of this new compound.

Dr Olds says: “We are at an exciting time in cancer research. Treatments that selectively seek out and attack only cancer cells have been with us for some years, but the results in the clinic are often disappointing. Now we’re beginning to understand why and find ways of improving their effectiveness. Although we are still some years away from this, we can envisage a future where chemotherapy will be toxic to tumours but not to patients, and for many that time cannot come soon enough.”

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