Switched off 'brake' gene increases pancreatic cancer risk

A gene that usually prevents excessive cell growth may be switched off in aggressive pancreatic cancers, scientists report.

The team found that the gene, USP9X, was non-functional in 50 percent of pancreatic tumour cells in mice. They also found a decrease in the levels of both the gene and its protein in over 400 pancreatic cancer patients.

'We suspected that the fault wasn't in the genetic code at all, but in the chemical tags on the surface of the DNA that switch genes on and off', said co-lead author Professor David Tuveson, from the Cancer Research UK Cambridge Research Institute.

Using samples of human pancreatic tumours, the international team, funded by Cancer Research UK, confirmed that the genetic code of USP9X was normal, and so the problems were likely to be due to external to the gene.

Professor Tuveson said: 'Drugs which strip away these tags are already showing promise in lung cancer and this study suggests they could also be effective in treating up to 15 percent of pancreatic cancers'.

Dr Julie Sharp, Cancer Research UK's senior science information manager said the results 'raise the possibility that a class of promising new cancer drugs may be effective at treating some pancreatic cancers'.

However, this study did not specifically test any drugs, and so further work is needed before a new treatment becomes available.

One of the most aggressive cancers, pancreatic cancer kills around 8,000 people every year, and only one in five people are still alive a year after diagnosis.

Despite extensive studies of the genetics of pancreatic cancer, USP9X has not previously been identified as significant.

Dr David Adams, co-lead author from the Wellcome Trust Sanger Institute, said that this study suggested researchers should 'look into the biology of cells to identify all the genes that play a role in cancer'.