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| Dr. Clark Chen, neurosurgeon, UC San Diego |
Researchers are finding more potential uses for existing drugs by repurposing them to treat other medical conditions. One class of FDA-approved antipsychotic drugs may provide a new approach to treating the most aggressive form of primary brain cancer, glioblastoma.
A team of scientists at the UC San Diego School of Medicine made the discovery, using a technology platform called small hairpin RNA (shRNA). The shRNA sequences function like molecular erasers to test how each gene in the human genome contributed to glioblastoma growth.
"We can design these 'erasers' against every gene in the human genome. These shRNAs can then be packaged into viruses and introduced into cancer cells. If a gene is required for glioblastoma growth and the shRNA erases the function of that gene, then the cancer cell will either stop growing or die," explained Dr. Clark Chen, codirector of neurosurgical oncology at UCSD.
Surprisingly, Chen and his team found many genes that aid glioblastoma growth are also required for dopamine receptor function. Abnormal dopamine regulation is implicated in many neurological and psychiatric disorders such as Parkinson's disease, schizophrenia and attention deficit hyperactivity disorder. Patients with these disorders are often prescribed dopamine antagonists, a class of antipsychotic drugs that block dopamine receptors.
When tested in both cultured cells and mouse models, Chen and his team found that dopamine antagonists elicited antitumor effects against glioblastoma. Combined with other antiglioblastoma drugs, the dopamine antagonists were also effective at halting tumor growth. The finding was published in this week's online edition of Oncotarget.
Repurposing already-approved drugs can get useful therapeutics to the market more quickly because of the already-established safety data. Chen is now working with the UC San Diego Moores Cancer Center to test the drugs in glioblastoma patients in a clinical trial.
- see the study
- read the press release