In a remarkable medical breakthrough that could transform treatment for one of the deadliest forms of brain cancer, researchers have discovered that a common blood pressure medication might hold the key to fighting glioblastoma.
Scientists at the University of Pennsylvania have uncovered an unexpected link between the cardiovascular drug hydralazine and its potential to combat this aggressive cancer, which affects approximately 12,000 people annually in the United States.
The Deadly Reality of Glioblastoma
Glioblastoma represents one of the most devastating cancer diagnoses, with patients facing exceptionally poor survival rates. This fast-growing brain tumour claims half of its victims within just 14 months of diagnosis, while only five percent of adult patients survive beyond five years.
The disease gained public attention when former Republican presidential nominee John McCain succumbed to glioblastoma in August 2018, merely 13 months after his initial diagnosis in July 2017.
What makes this cancer particularly aggressive is its ability to thrive in low-oxygen environments within the brain. The tumour achieves this by disrupting blood vessels, effectively reducing oxygen delivery to the areas where cancer cells are present.
An Unexpected Discovery
The research, published in the prestigious journal Science Advances, reveals how hydralazine - sold under the brand name Apresoline - might combat this deadly mechanism.
Of the 120 million high blood pressure patients in the US, approximately six million are currently treated with this medication, which costs around $0.33 per pill and works by widening blood vessels.
Dr Megan Matthews, the University of Pennsylvania chemist who led the study, expressed her excitement about the findings. 'It is rare that an old cardiovascular drug ends up teaching us something new about the brain,' she said. 'But that's exactly what we're hoping to find more of, unusual links that could spell new solutions.'
Groundbreaking Mechanism Revealed
In laboratory experiments, the research team made two significant discoveries. First, they identified the precise mechanism by which hydralazine reduces blood pressure - something that had remained unknown despite the drug being available for 70 years.
The medication works by binding to an oxygen-sensing enzyme called 2-aminoethanethiol dioxygenase (ADO), which becomes activated when oxygen levels drop. This enzyme breaks down regulators of G-protein signaling (RGS) proteins, causing blood vessels to constrict and blood pressure to rise.
Hydralazine blocks ADO, leading to protein build-up that triggers blood vessels to widen, thereby lowering blood pressure.
Even more promising was the second discovery: in separate lab tests, scientists found that hydralazine also blocked ADO in cancer cells. This action disrupted proteins that allow cancer cells to thrive in low-oxygen conditions, effectively putting the glioblastoma cells into a dormant, non-dividing state called cellular senescence.
A Ray of Hope for Patients
While the research remains in early stages and requires further testing, it represents a potential breakthrough for glioblastoma treatment. Current approaches typically involve surgery to remove tumours, combined with chemotherapy or radiation, but these methods usually only reduce symptoms or slightly prolong patients' lives.
The study marks the first time scientists have observed this particular mechanism and demonstrates how repurposing existing medications could lead to new cancer treatments more quickly than developing entirely new drugs.
Warning signs of glioblastoma include headaches, memory problems, personality changes, seizures, and speech difficulties, often appearing suddenly. While the exact causes remain unclear, previous radiation therapy and inherited genetic mutations have been linked to the disease in some cases.
As research continues, this unexpected connection between a common blood pressure medication and brain cancer treatment offers renewed hope in the fight against one of medicine's most challenging conditions.
