Blood cancer drug could make radiotherapy on brain tumors more effective

Drugs developed to fight blood and other cancers could also help improve the efficiency of radiotherapy in the most commonly diagnosed low-grade brain tumor in adults, a new study has found.

Meningioma accounts for approximately 36% of all primary brain tumors. The majority are successfully treated by surgery, but some which can’t easily be accessed need to be treated with radiotherapy. That can cause significant side effects and radiation damage to the brain, while resistance to radiotherapy can also result in tumor growth.

The study by researchers at the Brain Tumor Research Center of Excellence at the University of Plymouth looked in detail at the effects of that radiation damage but also ways of mitigating it.

Using meningioma cells, researchers discovered that radiation-induced damage can lead to cells producing an increased quantity of the enzyme histone deacetylase 6 (HDAC6), which has previously been shown to contribute to tumor growth.

However, by administering the HDAC6 inhibitor Cay10603 prior to radiotherapy, they were able to inhibit cellular growth—and increase cell death—in meningioma samples.

The study, published in the journal eBioMedicine, was led by Dr. Juri Na and Professor Oliver Hanemann, and they say their findings represent a potential promising approach to improving the treatment outcomes of malignant meningioma.

The research also builds on extensive and ongoing work by the Center of Excellence in Plymouth looking at the potential of already-approved medications to be repurposed as a way of helping brain tumor patients.

Dr. Na, Senior Research Fellow and the study’s lead author, said, “Cay10603 has been developed to HDAC, a common target for some approved blood cancer drugs. But our study shows that when used alongside radiotherapy, the drug reduces tumor cell growth and increases tumor cell death.

“It means that this combination treatment will kill cancer cells more efficiently while avoiding serious side effects that could be caused by heavy radiation treatment, as we can administer a low dose of radiation along with Cay10603.”

Professor Hanemann, Director of the Brain Tumor Research Center of Excellence at the University of Plymouth, added, “Pan-HDAC inhibitors have been approved by both US Food and Drug Administration and the European Medicines Agency, but Cay10603 is not currently licensed in the UK. And no HDAC inhibitors like it have been utilized in clinical settings.

“It means there are still steps to overcome before this treatment can begin to benefit patients directly, but this is certainly a positive development when you consider the lack of existing treatments available to meningioma patients.”