Biggest DNA cancer breakthrough in 20 years

Published on Monday 5 October 2009 19:59

SCIENTISTS have discovered that a faulty gene is linked to more than half of all breast cancers.

The gene is also thought to be implicated in half of bowel and prostate cancers, and a quarter of ovarian and bladder cancers.

The discovery was described as a "major step forward" by cancer charities and is possibly the most important development in cancer gene research in the past 20 years.

Dr Paul Edwards, of the department of pathology at the University of Cambridge, who discovered the gene with colleagues, said it provided "vital information" about how some cancers spread.

The gene, NRG1 (neuregulin-1), is located on chromosome 8, one of the packages of DNA that house genes within a cell. Experts have observed that cancerous cells are missing part of chromosome 8 – the section carrying the NRG1 gene. Normally, NRG1 works as a "guard", suppressing cancerous tumours. However, if it is missing or faulty, tumours are able to grow.

Dr Edwards and colleagues specifically looked at breast cancer tumours but believe the gene is also linked to other cancers.

Many cases of bowel, prostate, ovarian and bladder cancer are missing the same region of chromosome 8. Dr Edwards said: "I believe NRG1 could be the most important tumour-suppressor gene discovery in the last 20 years as it gives us vital information about a new mechanism that causes breast cancer.

"In every case that we looked at, where a big chunk of chromosome 8 had been lost, at least part of the gene was lost.

"The gene was effectively 'turned off' in a lot of breast cancers."

Everybody is born with an intact NRG1 but it gets damaged in some people during their lifetime. The exact reason why the gene is damaged and the part of chromosome 8 is lost has not yet been discovered.

However, by identifying the gene, experts hope they will be able to target therapies at specific cancers in the future.

The discovery of NRG1 is thought to be the most significant step forward in cancer gene research since another gene, p53, also a "tumour suppressor", was discovered in the 1970s and found to be implicated in cancers in the late 1980s.

The latest research was published in the journal Oncogene and funded by Breast Cancer Campaign and Cancer Research UK.

Arlene Wilkie, director of research and policy at Breast Cancer Campaign, said: "Knowing the identity of this gene will lead to far more detailed studies of how it works and how it is involved in breast cancer development."