For a family hearing the word glioblastoma, the odds are hard. Patients typically live less than 15 months after diagnosis, even with surgery, radiation therapy and chemotherapy. A new study in Oncoscience describes an early lead: a form of vitamin B12 that appears to reach brain tumors.
The compound is nitrosylcobalamin, called NO-Cbl, a B12 variant built to release nitric oxide. Joseph A. Bauer of Nitric Oxide Services, LLC and the Cleveland Clinic Foundation Taussig Cancer Center led the work as first and corresponding author. He and his team wanted to know whether NO-Cbl could cross the blood-brain barrier and settle selectively in tumors.
That barrier is a big part of the problem. It shields the brain and keeps many drugs from reaching tumor tissue.
What happened in the lab
The team tested NO-Cbl against cells in the NCI-60 human tumor cell line panel, ran pharmacokinetic studies in rats with glioblastoma, and tried it alongside other treatments in human glioblastoma cell lines.
Across the panel, the compound showed antitumor activity against a wide range of cancer types. Cells that began in the central nervous system responded moderately.
In the animals, NO-Cbl got across the barrier after systemic dosing and gathered in glioblastoma tissue. Nitrate levels stayed up in tumors for at least 24 hours but dropped faster in normal tissue. According to the report, that pattern suggests the compound is retained in tumors and releases nitric oxide there.
In U87 and D54 glioblastoma cells, pairing NO-Cbl with temozolomide, a chemotherapy drug, or with the experimental agent TRAIL curbed tumor growth much more than any treatment alone. Gulf News and ScienceDaily both relayed the authors’ conclusion: “This pilot study demonstrates that NO-Cbl crosses the BBB, accumulates selectively in brain tumor tissue, and synergizes with established and experimental glioblastoma therapies.”
How far along is it?
Not far, and the authors say so. They describe a pilot translational study and note that more research must come before clinical use. Planned follow-up includes orthotopic validation, dose optimization, longer tracking of nitric oxide activity and tests in more central nervous system tumor models.
Earlier research cited in the paper links NO-Cbl to cell-death signaling, which could make tumors that resist temozolomide more responsive.
Anyone dealing with a brain tumor diagnosis should talk with their doctor about treatment options.
Sources
- New vitamin B12 therapy shows promise against deadly brain cancer
- This new vitamin B12 therapy shows promise against deadly brain cancer: Study
