Research by Trinity Fellow, Professor Sir Shankar Balasubramanian, has shown for the first time that four-stranded DNA structures – known as G-quadruplexes – play a role in certain types of breast cancer.
The familiar two-stranded, double helix structure of DNA was discovered in 1953, but the team led by Sir Shankar have found that an unusual four-stranded configuration of DNA can occur across the human genome in living cells.
Crucially, their work also showed that G-quadruplexes are more likely to occur in genes of cells that are rapidly dividing, such as cancer cells. Now, in a collaboration with Carlos Caldas, Professor of Cancer Medicine and Director of the Cambridge Breast Cancer Research Unit, the team has discovered where the G-quadruplexes form in preserved tumour tissue/biopsies of breast cancer. Details of their study are published in the journal Nature Genetics.
Sir Shankar is the Herchel Smith Professor of Medicinal Chemistry at the University of Cambridge and Senior Group Leader at the Cancer Research UK Cambridge Institute. He said:
We’re all familiar with the idea of DNA’s two-stranded, double helix structure, but over the past decade it’s become increasingly clear that DNA can also exist in four-stranded structures and that these play an important role in human biology. They are found in particularly high levels in cells that are rapidly dividing, such as cancer cells. This study is the first time that we’ve found them in breast cancer cells.
The research highlights a potential weak spot that might be targeted against the cancerous tumour to develop better treatments.
There are thought to be at least 11 different subtypes of breast cancer, each of which may respond in different ways to different drugs. Identifying the tumour’s pattern of G-quadruplexes can pinpoint the subtype enabling more personalised treatment for individual patients.
The paper can be read here.