Barcoding brain tumours

Glioblastoma is considered one the deadliest cancers with an average five-year survival rate of only about 10 per cent with most succumbing to the disease in 15 months.

Researchers from the Hospital for Sick Children in Toronto and the University of Cambridge in the U.K. have worked together to better understand what drives the individual cells in this aggressive cancer. They also looked into what drugs could be used to target the cells within the tumour.

"What we did here was we took human tumours, broke them up into individual cells and then we infected those with a short DNA sequence," said co-principal investigator Dr Peter Dirks, a neurosurgeon and researcher at Sick Kids.

This resulted in thousands of different cells each with an individual barcode. When these cells divide their daughter cells inherit the parent cell's barcode. This inheritance of barcodes allows the researchers to trace the potential of each individual cell.

The barcoded cells were then injected into specialised lab mice and allowed to develop in tumours. These tumours were then removed and each of the cells were processed and their barcodes identified.

The sequencing identified which barcodes were present but also the frequency of the cells. They were also able to identify which cells form the tumours and ones that appear later on in development.

This tracking allowed researchers to discover that glioblastomas are made of many different clones and most follow two growth patterns. One, clone A, follows a predictable growth pattern and clone B cells are more rare but follow an extremely aggressive growth pattern.

This discovery suggests that there are now different ways to target this cancer. Researchers have already identified two drugs that target clones A and B individually.

This is another step towards new cancer treatments, targeting not just the tumour as one mutation but the process of the cells themselves.

"This paper brings a new approach and applies it to understanding the cellular composition of glioblastomas," Bernstein, president and CEO of the Canadian Institute for Advanced Research (CIFAR), said in a statement. "This is an important advance ... and it holds promise for finding new ways to diagnose and treat a very serious human cancer."

For more info see: bit.ly/BarcodeBrainTumours