THE fledgling field of gene therapy is beginning to bear fruit here, with promising results in curing normally fatal brain and liver cancers in animals.
In breakthrough work, scientists here have shrunken human tumours implanted in mice, and hope to test the technique on people soon.
The treatment involves using virus 'torpedoes' to carry cancer-seeking genetic 'warheads' into the patient's body, while leaving healthy cells unharmed.
'This is potentially a big advantage over chemotherapy and radiotherapy, which kill both types of cells indiscriminately,' said the man at the helm of such research, the National Cancer Centre's Dr Hui Kam Man.
He chose to work on brain cancer glioma because it occurs mainly in young people and children, and almost always kills them within a year.
About 150 people here get the disease every year. There are about 175,000 sufferers worldwide.
Dr Hui's team has cloned genes unique to glioma, and has deciphered the portion of the gene that allows it to do its damage.
Then, in a virus package that can be injected into the patient, the team combined DNA that kills cancer cells with DNA that allows the treatment to home in on only glioma cells which are replicating.
This is all placed into a virus 'transporter', which is itself coated with specific molecules, an additional targeting feature that allows it to home in on the cancerous cells.
Viruses are often the transport of choice for DNA, because they have evolved to infect cells.
However, they have also been blamed for causing cancer in some of the patients they were meant to treat.
'But the research has progressed over the years, so that we can be very specific and tailor-make the treatment to hit just the diseased cells, not the healthy ones,' said Dr Hui, the director of cellular and molecular research at the National Cancer Centre.
The scientists are using the same techniques to combat liver cancer.
Doctors here also treated 19 patients with cervical and ovarian cancer in trials a few years ago, using different gene therapy techniques.
The treated tumours shrank and the cancer regressed.
Dr Hui's team is currently using these methods - where fat molecules transport the effective cancer-zapping DNA to produce proteins to kill tumours - in a current trial on about 30 patients with head and neck cancer.
However, such treatments are unlikely to become commonplace soon, warns Dr Hui.
'They will not be mainstream for a while. Because of the bad name gene therapy has, people are not going to start any trials or announce any results until they are very, very confident of their success,' he said.
Gene therapy - once hailed as the great new hope of medicine - was given a bad reputation in 1999 when American teenager Jesse Gelsinger became its first casualty.
The gene-carrying virus that doctors had injected into him to cure a liver disorder poisoned him, causing massive organ failure.
But Dr Hui said that although more than 3,000 patients have undergone gene therapy so far, Jesse was the only fatality.
And although not all treatments have worked, this is still a far better record than some drug tests, he added, giving the example of the lung cancer drug Iressa, which the Japanese Health Ministry had linked to 173 deaths last year.
'But gene therapy is a very new discipline,' said Dr Hui, 'so if anything goes wrong, it is put under the microscope.'
Leading researchers around the world, however, have recognised the promise of this treatment, and are meeting here this weekend to present their latest results at an international conference on cancer gene therapy.
About 150 delegates are expected to attend.