A research team at the National Cancer Center (NCC) has discovered a clue for developing a new treatment that suppresses the invasion of surrounding normal tissues in malignant brain tumors.

The team, led by Professors Park Jong-bae and Hong Jun-hee, discovered receptor molecules, which make malignant brain tumors infiltrate the entire brain and make surgery and radiation treatment impossible, and a drug that regulates such a process.

Professor Lee Sung-hoon at Eulji University School of Medicine also participated in the study.

The researchers discovered NgR1, a regulatory protein for tumor cells that move along the cranial nerve circuit in malignant brain tumors. They confirmed that pimozide regulates this protein expression and inhibits tumor invasion through experiments on patient-derived brain tumor cell lines and preclinical trials.

They also found that pimozide, used clinically as an existing antipsychotic drug, increases NgR1 expression by antagonizing ubiquitin-specific protease 1 (USP1) and inhibitor DNA binding 1 (ID1), an upregulation of NgR1.

The team expects pimozide will control highly invasive brain tumors in patients who cannot receive surgery.

“The study confirmed that NgR1 is an important receptor for inhibiting the widespread invasion of malignant brain tumors through the cranial nerve circuit,” Professor Hong said.

Professor Park also noted that if hospitals can apply an inhibitor with proven stability, such as pimozide discovered in this study, with the existing standard treatment, they will be able to contribute to improving the survival rate of malignant brain tumor patients by continuously inhibiting the invasion of the cranial nerve circuit of brain tumors.

The results of the study were published in the journal BRAIN.