Researchers Discover Male-Only Gene That Protects Against Leukaemia
Scientists have discovered the first example of a gene that is only found in one sex, and provides protection against cancers including an aggressive form of leukaemia.
The gene is only found on the Y chromosome, which, until today, were thought to only contain the genetic information required for male sexual characteristics, rather than female.
This Y-chromosome gene appears to have an additional role — it protects against the development of Acute Myeloid Leukaemia (AML) and other cancers.
The discovery of this new role changes the way the Y-chromosome is viewed and improves understanding of how AML and other cancers develop, which could lead to new treatments.
Acute myeloid leukaemia is an aggressive blood cancer that affects people of all ages. It develops in cells in the bone marrow and leads to life-threatening infections and bleeding. Mainstream AML treatments have remained unchanged for decades.
Women have two X chromosomes whereas men have one X and one Y chromosome. The X and Y chromosomes share many genes, but a small number of genes, including UTY, are only found on the Y chromosome.
In the study, published in Nature Genetics, researchers at the Wellcome Sanger Institute and the University of Cambridge investigated how loss of the X-chromosome gene UTX, which is known to be mutated in many tumours, hastens the development of AML. However, they found that UTY, a related gene on the Y chromosome, protected male mice lacking UTX from developing AML.
The authors then show that in AML and in several other human cancers types, loss of UTX is accompanied by loss of UTY, confirming that the cancer-suppressing role of UTY extends beyond AML.
Professor Brian Huntly, of the University of Cambridge and a consultant haematologist at Cambridge University Hospitals NHS Trust, said: “It is known that men often lose the Y-chromosome from their cells as they age, however, the significance of this was unclear.”
“Our study strengthens the argument that loss of the Y-chromosome can increase the risk of cancer and describes a mechanism for how this may happen.”
In their study, researchers studied the UTX gene in human cells and in mice to try to understand its role in AML. In addition to their discovery that UTY acts as a tumour suppressor gene, the scientists found a new mechanism for how loss of UTX leads to AML.
They discovered that UTX acts as a common scaffold, bringing together a large number of regulatory proteins that control access to DNA and gene expression, a function that can also be carried out by UTY. When UTX/UTY are missing, these proteins can’t regulate gene expression correctly and cancer growth becomes more likely.
“Survival rates for AML remain tragically low, with current treatment that involves intensive chemotherapy, often combined with a stem cell transplant, only curing a small proportion of patients. This important research helps build a fuller picture of what goes wrong genetically as this highly aggressive leukaemia develops,” said Dr. Alasdair Rankin, director of research at the charity Bloodwise. “
Understanding this process is key to developing targeted drugs for AML, allowing us to move away from gruelling and often ineffective chemotherapy-based treatments.”