Host tissues and microenvironment

The host tissues and microenvironment represent the complex, multi-component milieu surrounding cells, consisting of the extracellular matrix (ECM), stromal cells (such as fibroblasts and immune cells), blood vessels, and a variety of signaling molecules like cytokines and growth factors (National Cancer Institute, 2023). Rather than being a single molecular target, it is a dynamic ecosystem that regulates cell behavior, survival, and migration through biochemical and mechanical cues (Nature Reviews Cancer, 2009). In diseases like cancer, the tumor microenvironment (TME) is often co-opted to support malignancy, promote angiogenesis, and suppress immune surveillance (Cancer Cell, 2012). Therapeutic strategies targeting this environment aim to reprogram the niche—for example, by inhibiting pro-angiogenic factors or blocking immune checkpoints—to restore normal function or enhance the efficacy of direct anti-tumor agents (Nature Medicine, 2013). However, the heterogeneity and complexity of the microenvironment pose significant challenges for drug development and precision medicine, often leading to off-target effects in healthy tissues (Nature, 2013).

Other names

Tissue microenvironmentCellular nicheExtracellular matrix and stromaTumor microenvironmentTME

Modulation of the extracellular matrix, inhibition of paracrine signaling (e.g., VEGF, TGF-beta), blockade of immune checkpoints, and alteration of the physical and chemical properties of the cellular niche (Nature Medicine, 2013).