This research identifies a specialized group of monocyte-derived tumor-associated macrophages (Mo-TAMs), termed Hypoxia-TAMs, which congregate in the necrotic regions of glioblastoma. Using single-cell transcriptomics and spatial analysis, the authors discovered that these cells are reprogrammed by the tumor's oxygen-depleted environment to secrete adrenomedullin (ADM). This protein destabilizes vascular integrity by disrupting endothelial junctions, resulting in leaky blood vessels that prevent effective drug delivery. The study demonstrates that using an ADM antagonist can normalize tumor vasculature and significantly enhance the concentration and efficacy of anti-cancer treatments like dabrafenib. Consequently, the presence of these specific macrophages serves as a prognostic indicator for poor patient outcomes and vascular hyperpermeability. Targeting this paracrine signaling pathway offers a promising therapeutic strategy to improve the management of aggressive brain tumors.

References:

• Wang W, Li T, Cheng Y, et al. Identification of hypoxic macrophages in glioblastoma with therapeutic potential for vasculature normalization[J]. Cancer cell, 2024, 42(5): 815-832. e12.