epitelimesenkymaalinen

Epitelimesenkymaalinen is a term used in cell biology to describe phenomena involving epithelial and mesenchymal characteristics and the transitions between these phenotypes. It can refer to cells that display a mix of epithelial and mesenchymal traits, or to processes that convert epithelial cells into mesenchymal-like cells, as in epithelial–mesenchymal transition (EMT), as well as the reverse process, mesenchymal–epithelial transition (MET).

In biology, EMT is a key mechanism during embryonic development, tissue remodeling, and wound healing, enabling cells to detach and migrate. In pathology, EMT and partial EMT states are linked to fibrosis and to cancer progression, particularly in tumor invasion and metastasis. Cancer cells often exhibit hybrid epithelial/mesenchymal states, which may enhance both mobility and the ability to interact with the surrounding microenvironment.

Molecularly, EMT involves downregulation of epithelial markers such as E-cadherin and upregulation of mesenchymal markers like N-cadherin and Vimentin. EMT transcription factors including Snail, Slug, Twist, and ZEB1/2, along with signaling pathways such as TGF-β, Wnt/β-catenin, Notch, and Hedgehog, regulate this process. MicroRNAs of the miR-200 family are important regulators that can restrict EMT.

The concept of epitelimesenkymaalinen thus encompasses the continuum of epithelial, mesenchymal, and intermediate states, reflecting cellular plasticity with significant implications for development, tissue homeostasis, and disease.