Fighting vessel dysmorphia to improve glioma chemotherapy

High-grade gliomas are aggressive and abundantly vascular tumors, and as in most cancer types, blood vessels in advanced lesions are highly abnormal. Poor perfusion and vascular leakage in tumor tissue resulting in hypoxia, necrosis, and high interstitial fluid pressure can hamper the efficient delivery of chemotherapy. Tumor angiogenesis is known to be supported by host leukocytes recruited to the tumor microenvironment, but the mechanisms leading to dysfunctional vascular network formation are incompletely understood. In this issue of EMBO Molecular Medicine, Mathivet et al (2017) present an elegant study, where longitudinal intravital imaging gives new insight on how recruitment and polarization of tumor-associated macrophages regulate aberrant angiogenesis in experimental gliomas. They show that macrophage targeting results in vessel normalization and improved chemotherapy response, suggesting that the combination of these therapeutic modalities could improve the outcome of glioma treatment in the clinic.