Vasculogenic mimicry

Vasculogenic mimicry (VM) is a phenomenon where tumor cells mimic endothelial cells to form blood vessel-like structures. This process allows tumors to create their own blood supply, contributing to tumor growth and metastasis. Vasculogenic mimicry challenges the traditional view that angiogenesis (the growth of new blood vessels from pre-existing vessels) is the sole mechanism of tumor vascularization. VM has been observed in various types of cancer, including melanoma, breast cancer, ovarian cancer, and glioblastoma.

Mechanism

Vasculogenic mimicry involves the differentiation of aggressive tumor cells into endothelial-like cells. These cells then organize into tubular structures that mimic blood vessels, facilitating the perfusion of the tumor mass. The process is regulated by various genes and signaling pathways, including the VEGF pathway, PI3K/AKT pathway, and the EphA2 receptor. The extracellular matrix also plays a crucial role in VM, with components like laminin and collagen being integral to the structure of the mimicry channels.

Clinical Significance

Vasculogenic mimicry is associated with poor prognosis in cancer patients, as it contributes to tumor growth, invasion, and metastasis. VM's presence in tumors is considered a marker of high tumor grade and aggressiveness. Furthermore, because VM can provide an alternative blood supply to tumors, it may contribute to resistance against anti-angiogenic therapies, which target traditional blood vessel growth.

Research and Therapeutic Implications

Understanding the mechanisms underlying vasculogenic mimicry could lead to the development of novel therapeutic strategies targeting this pathway. Inhibiting VM could potentially improve the efficacy of cancer treatments by cutting off an alternative blood supply to tumors. Research is ongoing to identify specific inhibitors of VM and to understand how VM integrates with other tumor vascularization mechanisms.

See Also

• Angiogenesis
• Cancer
• Metastasis
• Tumor microenvironment