Proteomic profiling of oleamide-mediated polarization in a primary human monocyte-derived tumor-associated macrophages (TAMs) model: a functional analysis

Abstract

Background. Tumor-associated macrophages (TAMs) play a critical function in the development of tumors and are associated with protumor M2 phenotypes. Shifting TAMs towards antitumor M1 phenotypes holds promise for tumor immunotherapy. Oleamide, a primary fatty acid amide, has emerged as a potent anticancer and immunomodulatory compound. However, the regulatory effects of oleamide on TAM phenotypes remain unclear. Methods. We used real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) techniques to study the influence of oleamide on primary human monocyte-derived TAM phenotypes, and we investigated the protein expression profiles based on mass spectrometry to analyze the effect of oleamide on macrophage polarization. Moreover, the advantageous binding scores between oleamide and these target candidate proteins are examined using molecular docking. Results. Our study revealed that oleamide effectively suppressed the M2-like TAM phenotype by reducing interleukin (IL)-10 production and downregulating M2-like markers, including vascular endothelial growth factor A (VEGFA), MYC protooncogene, bHLH transcription factor (c-Myc), and mannose receptor C-type 1 (CD206). Moreover, the conditioned medium derived from oleamide-treated TAMs induces apoptosis of MDA-MB-231 breast cancer cells. Proteomic analysis identified 20 candidate up- and down-regulation proteins targeted by oleamide, showing modulation activity associated with the promotion of the M1-like phenotype. Furthermore, molecular docking demonstrated favorable binding scores between oleamide and these candidate proteins. Collectively, our findings suggest that oleamide exerts a potent antitumor effect by promoting the antitumor M1-like TAM phenotype. These novel insights provide valuable resources for further investigations into oleamide and macrophage polarization which inhibit the progression of breast cancer, which may provide insight into immunotherapeutic approaches for cancer.