Figure 2.

Potential roles of epigenetic alteration in cancer cells and non-cancerous cells in the tumor microenvironment. First, epigenetic drugs can induce immunogenic cell death in cancer cells and increase the expression of tumor-associated antigens (TAAs) and major histocompatibility complex (MHC) and the production of antigen-presenting cells (APCs), thereby enhancing cancer cell recognition and T cell activation by the presentation of cancer-associated antigens. Second, epigenetic drugs target immune cells in the tumor microenvironment, leading to reduced myeloid-derived suppressor cell (MDSC) production and accumulation as well as decreased regulatory T (Treg) cell differentiation and function. Third, during these processes, epigenetic drugs typically result in increased production of Th cells, cytokines, and chemokines, decreased extracellular matrix (ECM) secretion, and inhibition of tumor suppressor gene (TSG) expression. In conclusion, there are complex interactions in the tumor microenvironment between cancer cells and non-cancerous cells that induce epigenetic alterations in each other, and epigenetic modifications play a role in these interactions.