Scientists unlock key gene secrets

AUSTRALIAN researchers have uncovered how a key cancer-fighting gene — one that is involved in at least half of all cancers globally — works to stop cancer growth.

The gene, called p53, is present in every cell in the body and has the job as the “master regulator” of cell growth and death.

But when it becomes mutated or faulty, it can no longer suppress the growth of tumours.

Co-lead author Dr Ana Janic said her team uncovered, for the first time, a number of other genes involved in DNA repair that are crucial to the function of p53.

When these other genes were removed, p53 could not function properly and lymphoma developed.

“This gene was discovered about 25 years ago, but until now we haven’t known that DNA repair is the major process that is critical for p53 to work as a tumour suppressor,” Dr Janic said.

The findings of the international study, led by Melbourne scientists at the Walter and Eliza Hall Institute of Medical Research, could lead to more effective treatments, allow doctors to better know what cancers will become more ag- gressive following chemotherapy, and help diagnose patients earlier.

“This has real outcomes for patients,” Dr Janic said.

“The p53 mutated tumour doesn’t usually respond to chemotherapy, it actually becomes more aggressive. This means there are people we shouldn’t use the chemo drugs in, and we need to explore other options for those people.”

Researchers around the world are developing ways to activate the gene’s ability to put the brakes on cancer growth, but these strategies are still in the laboratory.

Dr Janic, who led the work with Associate Professor Marco Herold and Professor Andreas Strasser, said understanding how p53 worked was the “holy grail” in cancer research.

It is mutated in about 70 per cent of colon and pancreatic cancers, and in almost every ovarian cancer type.

“This gene is faulty in 50 per cent of human cancers,” she said.

“This is why finding out how this gene works is a major question in the field — and why this finding is very exciting.”

The findings have been published in the prestigious journal Nature Medicine.