London, Feb 5 (IANS): A new gene therapy could have the potential to treat prostate cancer that causes 300,000 deaths worldwide each year, a new study said after it halted the majority of tumours in laboratory models.

The 'seek-and-destroy' gene therapeutic system was used against two types of prostate tumour and more than half of them vanished over a period of one month.

However, the therapy is currently in limited use due to lack of delivery systems that can selectively deliver the genes to the tumours without adverse side effects to healthy tissues.

The 'seek-and-destroy' nanomedicine linked to an iron-carrying protein called lactoferrin was developed and the study focussed on two prostate cancer cell lines -- PC-3 and DU145.

The intravenous administration of the nanomedicine treatment resulted in the complete disappearance of 70 per cent of the PC-3 tumours and half of the DU145 prostate tumours over one month, revealed the findings published in the journal Drug Delivery.

"Although some treatments, including chemotherapy and radiotherapy, can be effective against localised tumours, there is still no effective treatment for patients whose cancer recurs or spreads.

"This means that new therapeutic approaches are urgently needed for these patients," said Christine Dufes, senior Lecturer at the University of Strathclyde in Scotland.

Prostate cancer is the fourth most widespread cancer in the world.