06 November 2017
ByAppeared in BioNews 925
'Using this powerful toolkit, we've uncovered rare tumour suppressor genes that when lost in mutated cells cause cancer,' said author Dr Jonas Demeulemeester of the Francis Crick Institute in London. 'This could pave the way for the development of personalised cancer treatments.'
Human cells normally contain two copies of tumour suppressor genes, which help prevent them from turning cancerous. When both of these copies are lost, cells grow and divide uncontrollably forming tumours.
These double-gene abnormalities are hard to identify in cancer cells because tumours often contain both healthy and cancerous cells in unknown proportions. This makes it difficult to determine whether just one or both copies of the gene are missing.
The scientists developed a model that identified single nucleotide polymorphisms across the genome. This allowed them to analyse 2218 tumours across 12 cancer types, including breast, lung and bowel cancer. In every sample, they compared cancerous cells with healthy ones to find out how many copies of each gene there were in the unhealthy cells.
Their findings revealed 96 gene deletions among the tumours, which included 43 suppressor genes. From these, 16 were previously known while 27 were completely new. In addition, the scientists found harmful deletions to have a different 'DNA footprint' than smaller, non-harmful ones.
Senior author Dr Peter Van Loo of the Francis Crick Institute said: 'Our study demonstrates that rare tumour suppressor genes can be identified through large-scale analysis of the number of copies of genes in cancer samples.
'Cancer genomics is a growing area of research, and the computational tools we use are a powerful way to find new genes involved in cancer.'
The study was published in Nature Communications.