Cancer locator

A team of Purdue University researchers has synthesised a molecule that finds and penetrates prostate cancer cells and has created imaging agents and therapeutic drugs that can link to the molecule and be carried with it as cargo.

A radio-imaging application used for body scans is expected to enter clinical trials this year, and an optical imaging application used to measure prostate cancer cells in blood samples is already in clinical trials.

Purdue's Prof Philip Low said a targeted treatment could be much more effective in treating cancer and would greatly reduce the harmful side effects associated with current treatments.

'Currently none of the drugs available to treat prostate cancer are targeted, which means they go everywhere in the body as opposed to only the tumour, and so are quite toxic for the patient,' adds Low. 'By being able to target only the cancer cells, we could eliminate toxic side effects of treatments. In addition, the ability to target only the cancer cells can greatly improve imaging of the cancer to diagnose the disease, determine if it has spread or is responding to treatment.'

The molecule Low's team created attaches to prostate-specific membrane antigen, or PSMA, a protein that is found on the membrane of more than 90 per cent of all prostate cancers. It also is found on the blood vessels of most solid tumours and could provide a way to cut off the tumour's blood supply, Low said.

'A lot of new drugs are being designed to destroy the vasculature of solid tumours, and, if they could be linked to this new targeting molecule, we could have a two-pronged attack for prostate cancer,' he added. 'We could not only kill the prostate cancer cells directly, we could also destroy the vasculature that feeds the tumours.'

According to Low, there also is potential for the targeting molecule to be used to attack the vasculature of solid tumours of other types of cancers.