University of Virginia Comprehensive Cancer Centre scientists have developed a promising new experimental approach to targeting glioblastoma, the most common and deadliest brain cancer.

 The approach could overcome many of the limitations of treatments using existing drugs.

UVA’s Roger Abounader, MD, PhD, and colleagues have identified “microRNAs” that can simultaneously suppress multiple malfunctioning genes responsible for glioblastoma’s formation and growth.

The scientists use a combination of brain penetrating nanoparticles, focused ultrasound waves and microbubbles to deliver the miRNAs through the brain’s natural protective barrier – a barrier that typically blocks treatments for tumours and neurodegenerative diseases.

“This new approach could help target numerous molecules that promote cancer growth, including those for which no drugs exist, at the same time to achieve better therapies,” said Abounader, a professor at UVA’s School of Medicine, Department of Microbiology Immunology and Cancer Biology, Comprehensive Cancer Centre and Centre for RNA Science and Medicine.

“We are hoping to translate our findings into future clinical trials for patients with glioblastoma and other brain tumours.”

Treating Glioblastoma

Glioblastoma is the most common and aggressive malignant brain tumour in adults, killing more than 13,000 people in America alone every year.

It is difficult to treat because the tumours thread their way through healthy brain tissue, making them extremely hard to remove.

Meanwhile, the natural “blood-brain barrier” that protects the brain from infections and toxins also keeps out anti-tumour drugs.

Doctors now typically remove as much of the cancer as they can with surgery, then use radiation and chemotherapy to help patients survive as long as possible.

By using miRNA – tiny molecules of genetic material – Abounader’s approach would let doctors suppress the effects of multiple faulty genes at one time.

This would slow or stop tumour growth by blocking the genes driving the cancer.

Attempting to target multiple genes with existing treatments is complicated by the toxicity caused by combining multiple cancer drugs and by the fact that many molecules do not have drugs that target them.

Abounader would direct the miRNA to the brain using focused ultrasound guided by magnetic resonance imaging (MRI).

The highly focused sound waves guide tiny “microbubbles” to open the blood-brain barrier just long enough for the miRNA nanoparticle carriers to make their way through.

Testing their approach in the lab, Abounader and his team found that the miRNA was effective at slowing tumour growth and extending survival in glioblastoma animal models.

More research will be needed before the approach could be tested in people, but Abounader says the results are a positive indicator for the approach’s potential not just for glioblastoma but for other cancers as well.

“This approach could have broad applications for several brain and other human diseases,” Abounader said.

“We and many others are intensively working to lighten the burden of cancer, and hopefully also completely cure it, but this requires a continued investment in cancer and medical research.”

Focused Ultrasound at UVA

UVA Health was one of the earliest pioneers in the field of focused ultrasound.

UVA’s expertise with the technology has led to a robust research programme examining the use of focused ultrasound to treat many different conditions.

The technology’s tremendous promise prompted UVA and the Charlottesville-based Focused Ultrasound Foundation to launch the Focused Ultrasound Immuno-Oncology (FUSION) Centre, the world’s first centre dedicated specifically to exploring the benefits of combining focused ultrasound with cancer immunotherapy.

Experts hope the treatment approach could revolutionise cancer care for the 21st century.

Finding new ways to improve patient care is a core mission of both UVA Comprehensive Cancer Centre and UVA’s Paul and Diane Manning Institute of Biotechnology.

UVA Comprehensive Cancer Centre is one of only 57 cancer centres in the country to earn the elite “comprehensive” designation from the National Cancer Institute in recognition of their exceptional patient care and cutting-edge cancer research.

The Manning Institute, meanwhile, has been launched to accelerate the development of new drugs and cures for the most complex and challenging diseases.

This is being complemented by a statewide clinical trials network that expands access to potential new treatments as they are developed and tested.

Findings Published

Abounader and his colleagues have described their approach and the results of their initial lab testing in JCI, the Journal of Clinical Investigation.

Source: University of Virginia Health System