Tumor-associated endothelial cell

Tumor-associated endothelial cell

Tumor-associated endothelial cells (TECs) are a specialized type of endothelial cell that line the blood vessels within tumors. These cells play a crucial role in tumor angiogenesis, the process by which new blood vessels form to supply nutrients and oxygen to the tumor, facilitating its growth and metastasis.

Characteristics

TECs differ from normal endothelial cells in several ways. They often exhibit abnormal morphology, such as irregular shapes and sizes, and have distinct genetic and protein expression profiles. These differences are thought to be induced by the unique tumor microenvironment, which includes hypoxia, acidic pH, and the presence of various growth factors and cytokines.

Function

The primary function of TECs is to support the growth and survival of tumors by forming new blood vessels. This process, known as angiogenesis, is critical for tumor progression. TECs respond to pro-angiogenic signals, such as vascular endothelial growth factor (VEGF), by proliferating and migrating to form new vascular networks.

Role in Cancer Therapy

TECs are a target for anti-angiogenic therapies, which aim to inhibit the formation of new blood vessels and thus starve the tumor of nutrients and oxygen. Drugs such as bevacizumab, a monoclonal antibody against VEGF, have been developed to target these cells. However, TECs can develop resistance to such therapies, necessitating the development of new strategies to effectively target them.

Visualization

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Advanced imaging techniques, such as photoacoustic imaging, have been employed to visualize TECs and the vasculature of tumors. These techniques provide valuable insights into the structure and function of tumor blood vessels, aiding in the development of targeted therapies.

Enhanced Permeation and Retention Effect

{{#ev:svg|https://upload.wikimedia.org/wikipedia/commons/4/4e/Enhanced_Permeation_and_Retention_%28EPR%29_effect.svg%7Cthumb%7CEnhanced Permeation and Retention (EPR) effect}}

The Enhanced Permeation and Retention (EPR) effect is a phenomenon observed in tumors where macromolecules and nanoparticles tend to accumulate more in tumor tissue than in normal tissues. This is due to the leaky vasculature and poor lymphatic drainage associated with TECs, making them a target for drug delivery systems designed to exploit the EPR effect.

Related pages

• Angiogenesis
• Cancer
• Endothelial cell
• Vascular endothelial growth factor

References

• Folkman, J. (1971). "Tumor angiogenesis: therapeutic implications." *New England Journal of Medicine*, 285(21), 1182-1186.
• Carmeliet, P., & Jain, R. K. (2000). "Angiogenesis in cancer and other diseases." *Nature*, 407(6801), 249-257.
• Ferrara, N. (2004). "Vascular endothelial growth factor: basic science and clinical progress." *Endocrine Reviews*, 25(4), 581-611.

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  Visualization of tumor-related blood vessels in human breast by photoacoustic imaging system

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  Enhanced Permeation and Retention (EPR) effect