Targeting ENO1 reprograms macrophage polarization to trigger antitumor immunity and improves the therapeutic effect of radiotherapy.

Enolase 1 (ENO1) is a glycolytic enzyme involved in tumor progression that performs a variety of classical and nonclassical functions. However, the mechanism by which it promotes tumor progression is still not fully understood. Here, we revealed that TGFβ1/Smad3 signaling triggered the symmetric dimethylation of arginine (SDMA) on ENO1 by protein arginine methyltransferase 5 (PRMT5), leading to membranous ENO1 translocation. Surface ENO1 interacts with monocarboxylate transporter 4 (MCT4) for lactate secretion, which recruits M2 macrophages and promotes an immunosuppressive tumor microenvironment (TME). Targeting surface ENO1 with HuL001, a first-in-class humanized antibody, significantly reduced glycolysis, decreased extracellular lactate accumulation, reprogrammed macrophage polarization and inhibited tumor growth and distant metastasis. Moreover, targeting surface ENO1 significantly increased the therapeutic response to radiotherapy and delayed tumor regrowth by increasing antitumoral M1 macrophages and cytotoxic CD8(+) T cells infiltration within TME. These results indicated that targeting surface ENO1 remodeled the tumor microenvironment and provided better therapeutic effects to radiotherapy in poorly immunogenic colorectal cancer (CRC) and triple-negative breast cancer (TNBC).