Glioblastomas are generally incurable partly because monocytes, macrophages, and microglia in afflicted patients do not function in an antitumor capacity. Medications that reactivate these macrophages/microglia, as well as circulating monocytes that become macrophages, could thus be useful to treat glioblastoma. We have discovered that niacin (vitamin B3) is a potential stimulator of these inefficient myeloid cells. Niacin-exposed monocytes attenuated the growth of brain tumor–initiating cells (BTICs) derived from glioblastoma patients by producing anti-proliferative interferon-α14. Niacin treatment of mice bearing intracranial BTICs increased macrophage/microglia representation within the tumor, reduced tumor size, and prolonged survival. These therapeutic outcomes were negated in mice depleted of circulating monocytes or harboring interferon-α receptor–deleted BTICs. Combination treatment with temozolomide enhanced niacin-promoted survival. Monocytes from glioblastoma patients had increased interferon-α14 upon niacin exposure and were reactivated to reduce BTIC growth in culture. We highlight niacin, a common vitamin that can be quickly translated into clinical application, as an immune stimulator against glioblastomas.

胶质母细胞瘤通常是不能治愈的，部分原因是患病患者中的单核细胞，巨噬细胞和小胶质细胞没有抗肿瘤功能。重新活化这些巨噬细胞/小胶质细胞以及成为巨噬细胞的循环单核细胞的药物因此可用于治疗胶质母细胞瘤。我们发现烟酸（维生素B3）是这些低效率骨髓细胞的潜在刺激剂。烟酸暴露的单核细胞通过产生抗增殖干扰素-α14来抑制源自胶质母细胞瘤患者的脑肿瘤引发细胞（BTIC）的生长。烟酸治疗带有颅内BTIC的小鼠增加了肿瘤内巨噬细胞/小胶质细胞的表达，减小了肿瘤的大小，并延长了生存期。在缺乏循环单核细胞或具有干扰素-α受体缺失的BTIC的小鼠中，这些治疗结果无效。与替莫唑胺联合治疗可提高烟酸促进的生存率。来自胶质母细胞瘤患者的单核细胞在烟酸暴露后具有增加的干扰素-α14，并被重新激活以减少培养物中BTIC的生长。我们着重介绍烟酸，一种可以快速转化为临床应用的常见维生素，作为针对胶质母细胞瘤的免疫刺激剂。