Gene involved in most lung cancers found

Researchers from medical charity Cancer Research UK have discovered a new gene that protects against lung cancer, according to a study published today in the journal Proceedings of the National Academy of Sciences..

The activity of the gene, dubbed LIMDI, was reduced in all of the lung cancer samples the researchers tested, suggesting the gene plays an important role in stopping lung tumours developing. Lung cancer is the leading cause of cancer death in the UK, and it is notoriously difficult to treat.

Very little is known about the molecular basis of lung cancer. The team - based at University College London - believes LIMD1 may be an important piece in the puzzle, and hope their work may ultimately lead to new drugs to prevent and treat the disease.

The researchers also plan to investigate whether constituents of tobacco smoke could be partly responsible for damaging the LIMD1 gene.

LIMD1 is located on part of chromosome 3 called 3p21. Scientists have long suspected that 3p21 is home to important tumour suppressor genes, as it is missing in many types of cancers.

The researchers at the Wolfson Institute for Biomedical Sciences at University College London, where the discovery was made, said that chromosome region 3p21 is known to be missing in more than 90 per cent of lung tumours.

The team not only found that mutations in LIMD1 were very common in lung cancer samples, strongly implicating the mutations in the development of cancer, but also that restoring LIMD1 function to lung cancer cells in mice significantly delayed tumour growth.

Tyson Sharp, who led the research team at the Wolfson Institute, says: "We have found a new tumour suppressor gene. Chromosome 3p is often deleted early in the development of lung cancer, which implies that inactivation of the LIMD1 gene could be a particularly important event in the early stages of lung cancer."

He noted that identifying mutations in key genes such as LIMD1 could enable earlier diagnosis of cancer, as they are early warning signs that something is going wrong.

Scientists will now look to see if cancer-causing toxins in tobacco leads to damage of chromosome 3p and subsequent LIMD1 inactivation. Such a finding would be an invaluable step towards explaining how lung cancer develops.