Pro-inflammatory M1 macrophages, a type of white blood cell involved in immune responses, have been found to accelerate the progression of melanoma through the extracellular vesicles they secrete, according to new research from the University of Eastern Finland. The study was published in Cell Communication and Signaling.
Researchers investigated how extracellular vesicles released by pro-inflammatory M1 macrophages influence melanoma cells. These vesicles are small particles surrounded by membranes that are secreted by all cells and play a role in communication between them. In tumors, this intercellular communication appears especially significant.
The study showed that extracellular vesicles from M1 macrophages carry inflammatory mediators such as the cytokines TNFα and IL-1β. These molecules are delivered into cancer cells via the vesicles. Additionally, these vesicles activate the NF-κB signaling pathway within target cells—a pathway central to inflammation. This activation creates an inflammatory environment that increases the aggressiveness and invasiveness of cancer cells, making them more capable of penetrating surrounding tissue.
Interactions between tumor cells and macrophages within their microenvironment occur constantly. According to the researchers, understanding these mechanisms is important for identifying new targets for cancer therapy.
"The findings reveal a key mechanism by which macrophages and cancer cells communicate with one another. This opens up new avenues for discovering methods that could break the inflammatory cycle that fuels tumor growth," stated members of the research team.
The work was carried out at the Institute of Biomedicine at the University of Eastern Finland in Associate Professor Sanna Pasonen-Seppänen's group. The study received support from several organizations including iCANDoc, Cancer Foundation Finland, North Savo Cancer Association, Finnish Cultural Foundation, Paavo Koistinen Foundation, Orion Research Foundation, and Kuopio University Foundation.
