Itaconate-treated macrophage exosomes boost breast cancer cell invasion in vitro

Exosomes released by macrophages exposed to dimethyl itaconate promoted epithelial–mesenchymal transition, migration, and invasion in MCF-7 breast cancer cells in laboratory experiments. The study found that the extracellular vesicles increased several mesenchymal-associated proteins, reduced the epithelial marker E-cadherin, and enhanced two cell-behavior assays. It did not significantly change apoptosis, indicating that the observed effects were not accompanied by a detectable increase in programmed cell death under the tested conditions.

Researchers treated U937 macrophage cells with 250 micromolar dimethyl itaconate, or DMI, for 48 hours. They then isolated exosomes from the treated cultures, characterized the vesicles and applied them to MCF-7 cells. Western blotting was used to measure proteins associated with epithelial–mesenchymal transition, including E-cadherin, N-cadherin, ZEB1/2, Slug, and Vimentin. Exposure to the DMI-derived exosomes, designated DMI-EXO, significantly increased N-cadherin, ZEB1/2, Slug, and Vimentin while reducing E-cadherin. Together, these protein changes were consistent with a shift in the cancer cells toward a more mesenchymal state.

The investigators also examined microRNAs associated with EMT regulation. Quantitative real-time PCR showed that DMI-EXO significantly reduced miR200C-5p and miR30C-5p, two of the EMT-suppressive microRNAs assessed in the study. No significant change was detected in miR-137 expression. The results connect altered microRNA abundance with the protein changes associated with EMT, although the experiments do not establish that either microRNA was the direct mechanism responsible for migration or invasion. The study also evaluated miR-638, but the supplied results do not report a specific change in that microRNA.

Functional assays showed that the DMI-EXO treatment affected the movement of MCF-7 cells. In the scratch wound-healing assay, treated cells closed the artificial gap faster than comparison cells. In a Transwell invasion assay, the DMI-EXO group developed a larger invaded area. These measurements support enhanced migration and invasion, respectively. By contrast, Annexin V/propidium iodide staining showed no significant alteration in apoptosis after DMI-EXO exposure. The findings therefore point to changes in motility and invasion rather than a detectable change in cancer-cell death as the principal response under the experimental conditions.

This work provides evidence that macrophage-derived extracellular vesicles can transmit a tumor-associated influence between immune cells and breast cancer cells. Itaconic acid is an immunometabolite involved in macrophage polarization within the tumor microenvironment, but its effects on cancer progression have remained debated. The present results suggest one possible route: DMI treatment alters what macrophages release in exosomes, and those vesicles then promote EMT-associated protein and microRNA patterns together with greater migration and invasion in recipient MCF-7 cells. The findings are nevertheless limited to an in vitro cell-culture model, one macrophage cell line, one breast cancer cell line, and specified treatment conditions. They do not show that dimethyl itaconate produces the same effects in intact animals or people, and they do not demonstrate improved outcomes for patients with breast cancer.

Subject of Research: Effects of dimethyl-itaconate-treated macrophage exosomes on EMT, migration, invasion, and apoptosis in MCF-7 breast cancer cells

Article Title: Exosomes derived from itaconate-treated macrophages promote epithelial–mesenchymal transition, migration, and invasion in MCF-7 breast cancer cells

Article References: Siahi, F. H., Yektaseresht, A., & Tabandeh, M. R. (2026). Exosomes derived from itaconate-treated macrophages promote epithelial–mesenchymal transition, migration, and invasion in MCF-7 breast cancer cells. Medical Oncology, 43(11), Article 348. https://doi.org/10.1007/s12032-026-03468-3

Image Credits: AI Generated

DOI: 10.1007/s12032-026-03468-3

Keywords: breast cancer cells, macrophage exosomes, dimethyl itaconate, epithelial–mesenchymal transition, cell migration, cell invasion, microRNAs, tumor microenvironment, in vitro research, Exosomes, derived, itaconate-treated