Tumor Microenvironment and Cancer Immunity
The tumor microenvironment (TME) represents the intricate milieu surrounding a tumor, comprising various cellular and non-cellular components that intricately interact with cancer cells. This dynamic and multifaceted environment exerts a profound influence on tumor progression, metastasis, and response to therapy. The TME is a complex network of immune cells, fibroblasts, blood vessels, extracellular matrix components, and signaling molecules, collectively orchestrating a supportive or inhibitory landscape for the tumor.
Within the TME, specific protein markers play crucial roles in modulating tumor behavior and are often indicative of the immune response, angiogenesis, and extracellular matrix composition.
Some notable protein markers specific to the TME include:
PD-L1 (Programmed Death-Ligand 1): PD-L1 is expressed on the surface of tumor cells and immune cells within the TME. Its interaction with PD-1 on immune cells can suppress the immune response, facilitating immune evasion by the tumor.
TGF-β (Transforming Growth Factor-beta): TGF-β is a multifunctional cytokine in the TME that regulates processes such as cell proliferation, differentiation, and immune response. Its dysregulation contributes to the immunosuppressive nature of the TME.
VEGF (Vascular Endothelial Growth Factor): VEGF is a key protein involved in angiogenesis within the TME. It promotes the formation of new blood vessels, supporting tumor growth and providing a route for metastatic spread.
Granzyme B: Granzyme B is an enzyme released by cytotoxic T cells and natural killer cells within the TME. Its presence reflects the cytotoxic activity of the immune response against tumor cells.