Angiogenesis, the formation of new blood vessels, is a tightly controlled process with a key role in normal growth, development, wound healing, and transplantation rejection. When angiogenic pathways are disrupted, insufficient or excessive angiogenesis results in diseases such as coronary artery disease, ischemic chronic wound healing, autoimmune disease, macular degeneration, and cancer.
Angiogenic signaling in tumors is similar to normal angiogenesis, mediated by soluble growth factors, membrane-bound receptors, and cell-cell and cell-matrix interactions. Such signaling regulates cell migration, which is vital to angiogenesis. However, there are multiple differences between tumor angiogenesis and normal blood vessel formation.
Tumor endothelial cells proliferate faster than nontumor endothelial cells. Tumor vasculature differs from normal vasculature in morphology, enhanced leakiness, and structural abnormalities. Finally, tumor vessels are often less efficient at transporting oxygen to and removing waste products from all of the tumor tissues, resulting in frequent tumor cell necrosis.
The study of individual biomarkers, whether intracellular or circulating, is often inadequate to fully characterize the angiogenesis process in both normal and diseased states. Multiplexing of analytes offers significant advantages when studying complex pathways and biomarker interactions such as that found in angiogenesis.
This tutorial will describe the use of xMAP® bead-based, multiplexing technology (Luminex) with the MILLIPLEX® MAP Human Angiogenesis/Growth Factor Panel 1 (EMD Millipore). The panel includes 17 analytes that can be “plexed” together to study the role of circulating angiogenic biomarkers in a variety of diseases, as well as normal growth and development.