Electroacupuncture normalized tumor vasculature by downregulating glyoxalase-1 to polarize tumor-associated macrophage to M1 phenotype in triple-negative breast cancer

Background: Triple-negative breast cancer is a particularly aggressive type of breast cancer that is closely associated with abnormal vascularization within the tumor. However, traditional anti-VEGF therapies and other treatments have limited efficacy. Tumor-associated macrophages (TAMs) induce and regulate tumor angiogenesis. In recent years, regulating TAMs polarization has become a hot topic for research with objectives to normalize tumor vasculature and improve drug delivery and the tumor microenvironment. Our previous studies have found that peritumoral electroacupuncture (EA) can regulate tumor angiogenesis, but the underlying mechanism remains unclear.

Methods: In this study, we examined the phenotype of TAMs and inflammatory factors to observe the effect of peritumoral electroacupuncture on the phenotypic polarization of TAMs. Based on this, we evaluated the structure and function of tumor vasculature. Finally, we conducted a preliminary exploration of the mechanism underlying the regulation of TAMs phenotypic polarization by peritumoral electroacupuncture.

Results: In this study, we found that peritumoral electroacupuncture could promote the phenotypic polarization of TAMs toward the M1 type, thereby reducing microvascular density in tumor tissue, increasing pericyte coverage, improving the stability of the basement membrane, promoting vascular maturation, and enhancing perfusion while reducing tissue hypoxia.

Conclusions: Peritumoral electroacupuncture can promote the phenotypic polarization of TAMs toward the M1 type, leading to normalization of tumor vascular structure and function. The mechanism may be related to the downregulation of glyoxalase-1 and subsequent activation of the MGO-AGEs/RAGE axis.