Canadian researchers showed in cell cultures and in mice,
vitamin B3 (Niacin) helps the immune system to fight
glioblastoma — an incurable brain tumor. In large doses the drug vitamin
reduced the size of the tumor in the brain of model animals and extended their life,
especially in combination with standard chemotherapy. In the article in Science Translational Medicine
the authors also showed the mechanism of action of the substance: it has activated the surrounding
tumor immune cells, which were inhibited cells
Glioblastomas account for more than half of all primary
brain tumors and the most aggressive: the average life expectancy
patients even with treatment is 15 months. A distinctive feature of this
the type of tumor is the ability to make others immune cells immunosuppressive
properties. As a result, microglia instead of having to fight the tumor,
helps it grow, suppressing inflammation and the activity of other immune cells,
that go along with infiltration.
One of the therapeutic approaches is the inhibition of activity
of microglia, so it does not interfere with other cells to destroy the tumor. In search of
drug with such activity, the staff of the Department of clinical neurobiology, University of
Calgary checked the library of 1040 compounds. In particular, they found
what is Niacin (aka nicotinic acid, vitamin B3, vitamin PP), in large concentrations, on the contrary,
stimulates the activity of monocytes (from which the macrophages and cells
of microglia). Apparently, vitamin activated in their products
Pro-inflammatory molecule interferon-alpha-14.
This substance is used not only as a vitamin but as a drug
from atherosclerosis, in which it is administered in large (gram) doses. Now
the researchers decided to test its activity in glioblastoma.
Scientists had nine stem cell cultures
glioblastoma cells obtained during operations of patients. They found that in
unlike the “normal” precursors of macrophages, cultured with 100 µmol
Niacin (the concentration of a substance observed in the plasma of people taking
Niacin in atherosclerosis) monocytes actively inhibit proliferation of tumor
cells in vitro.