By Wilson da Silva
SYDNEY – Scientists in Australia, claiming a breakthrough, said yesterday they had reversed the growth of cancer cells by “switching off” the gene that caused the disease.
Professor Hiroto Naora of the Australian National University in Canberra said in an interview that a genetic engineering process developed by his group had dramatically reversed the growth of fibrosarcoma cancer in a laboratory culture.
The process worked quickly and was so thorough that the cancer cells were quickly restored to a normal and benign state.
The five-person team introduced a gene close to a cancer-causing oncogene and used a biochemical trigger to stimulate it.
This provoked a battle between the two in which the quiescent gene deformed the rogue oncogene and rendered it inactive.
Prof. Naora “likens it to Ninja Turtles,” said university spokesman Maureen Barnett, referring to the popular Teenage Mutant Ninja Turtles children’s television series.
“You arm the genes, send them in and they win the battle.”
Prof. Naora said his team had also switched off oncogenes in laboratory mice that have a genetic arrangement similar to humans.
Further testing was under way to check whether the cancer cells in mice also reverted to normal.
There was no apparent reason why the process could not be used to control human cancers. The first effects on cancer genes in the culture were apparent within hours, Prof. Naora said.
“We’ve got to do a lot of basic research before it can be applied to human cancer genes,” he said. “But this result is very exciting for us.”
The development, the result of six years work, was the first time a cancer gene had been deactivated and reversed in a laboratory. Positive results were first detected six months ago, Prof. Naora said.
The researchers stressed that both the trigger gene and the oncogene were artificially placed near each other.
In theory the trigger could be inserted in a naturally occurring cancer and activated, but this would be a difficult clinical process.
There are 30 known human oncogenes, and the researchers said it would be easier for them to find naturally occurring trigger genes than to insert one near the oncogene.
The mechanism was comparable to the ecological principle that no two species can occupy the same niche in nature, Prof. Naora said.
The professor, who leads a team of Chinese and Australian researchers, said the discovery may not lead to clinical application for eight to 10 years.