Studying cancer genomes gene by gene could improve treatment

PRECISION MEDICINE holds that, because people are unique, so too are their diseases. It aims to prescribe treatments tailored to the genetic and biochemical characteristics of individual patients. Achieving this, in the context of oncology, is the purpose of the Cancer Dependency Map (DepMap), which is being developed jointly by the Wellcome Sanger Institute, near Cambridge, in Britain, and the Broad Institute in the city in Massachusetts of that name. Cancer is a good candidate for the application of precision medicine. because it arises when previously well-behaved cells start reproducing uncontrollably, usually as a result of a mutation in their genetic code. Numerous mutations can have this result, so many tailored treatments may be possible. DepMap seeks to find both mutations and treatments.

The first step, as Jesse Boehm, who runs the Broad’s side of the project, explained to this week’s AAAS meeting, is to grow cancerous tissue in laboratories, where it can be studied at researchers’ convenience. Before DepMap began, around 1,700 lines of lab-grown cancer cells were available. To try to increase this number, the project’s scientists turned to social media. Working with American cancer charities they encouraged patients across the country to send in biopsies of their tumours. That has given them more than 2,000 new samples, from which they have been able to create more than 400 extra cell lines. Encouragingly, 30% of these represent cancers that are either rare or occur mostly in children—both groups that researchers need more examples of.