Biochemical Signaling in Metastasis
Biochemical Signaling in Metastasis
Metastasis is a complex process by which cancer cells spread from the primary tumor to other parts of the body, forming secondary tumors. This process involves a series of steps, including invasion of surrounding tissues, intravasation into blood or lymphatic vessels, survival in the circulation, extravasation at distant sites, and colonization and growth at new locations. Biochemical signaling plays a crucial role in regulating each of these steps, allowing cancer cells to adapt to new environments and successfully establish secondary tumors.
Cell Adhesion and Migration
One of the first steps in the metastatic cascade is the invasion of cancer cells into surrounding tissues. This process is facilitated by changes in cell adhesion molecules, which allow cancer cells to detach from the primary tumor and migrate through the extracellular matrix. Signaling pathways such as the integrin pathway and the Rho GTPase pathway regulate cell adhesion and migration, allowing cancer cells to move through the tissue and invade blood or lymphatic vessels.
Angiogenesis and Intravasation
Once cancer cells have invaded surrounding tissues, they require a blood supply to support their growth and survival. Angiogenesis, the process by which new blood vessels are formed, is regulated by a variety of signaling molecules, including vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). These molecules promote the growth of new blood vessels, allowing cancer cells to access the circulatory system and intravasate into blood vessels.
Extravasation and Colonization
After intravasation, cancer cells must survive in the circulation and extravasate at distant sites to form secondary tumors. Signaling pathways such as the PI3K/Akt pathway and the NF-κB pathway promote cancer cell survival in the circulation and facilitate extravasation into distant tissues. Once cancer cells have extravasated, they must adapt to the new microenvironment and establish secondary tumors through processes such as proliferation and evasion of the immune system.
