The interaction of cells with the basement membrane is an important factor in the regulation of cell behavior. The extracellular matrix (ECM) is secreted by cells to form an interstitial basement membrane that forms the framework to which cells are attached. The basement membrane separates cells from mesenchymal connective tissue and provides spatial orientation and stability required for the growth and differentiation of cells. The ECM has also been implicated in the sequestration, storage and presentation of growth factors to tissues.
The reconstituted basement membrane BD Matrigel™ Matrix is derived from the Engelbroth-Holm-Swarm (EHS) mouse sarcoma, which has been found to be a rich source of ECM proteins. The BD Matrigel™ Matrix is composed of laminin, collagen IV, nidogen/enactin and proteoglycan - a composition comparable to basement membrane proteins. The BD Matrigel™ Matrix has been found to induce differentiation in a variety of cell types such as hepatocytes, mammary epithelial cells and endothelial cells. My research work involves the use of BD Matrigel™ for "in-vitro angiogenesis assays" using primary endothelial cells. When endothelial cells are plated on BD Matrigel™, the cells stop proliferating, display high motility and cell-cell communication. Furthermore the cells align and form a three dimensional network of capillary tubes (within 24 hours) that has been proposed as a model of endothelial cell differentiation as well as the final step of the angiogenic cascade.
I have found the BD Matrigel™ Matrix highly useful in all my studies involving angiogenesis, invasion and chemotaxis of tumor cells. The matrix is liquid at 2-8C and gels rapidly at 22C to 37C. I have found various batches of BD Matrigel™ to be highly reproducible in its ability to induce capillary tube formation in endothelial cells. The capillary tube formation is highly reproducible both in the thickness as well as the area of the tube-like structures, as measured by image analysis. The matrix is compatible with all culture media and additives. The quality control of each batch is stringent. It is free from endotoxin, bacteria, fungi and mycoplasma. Each batch of BD Matrigel™ is tested for its biological activity to promote differentiation in chick dorsal root ganglion. The product is supplied with a specification sheet containing detailed instructions for its use in various assays. Recent references are provided to help beginners familiarize themselves with the product and its potential applications. The company has an excellent "technical support team" to help troubleshoot and answer queries.
The inhibition of tumor angiogenesis has emerged as one of the promising approaches for the development of anticancer drugs. Over the past few years this spurt in angiogenesis research has increased the demand for BD Matrigel™ Matrix dramatically. The main problem with the product is that there are few suppliers for it, so it is often back-ordered. Furthermore, BD Matrigel™ is a heterogenous basement membrane reconstitution and some of its components are as yet unknown and undefined, which can sometimes make critical interpretation of results difficult. The proteases in tumor biopsy samples, for example, can often digest the matrix and thereby inhibit cell differentiation.
The alternate assays used to study tumor angiogenesis are the chick chorioallantoic membrane (CAM) assay, transparent chamber preparations like dorsal skin-fold chamber, rat corneal pocket assay etc., all of which are laborious to perform and require specialized skills. The biggest advantage of the BD Matrigel™ Matrix is the simplicity of the "in-vitro angiogenesis assay" and its reliability and reproducibility. It can be used with primary endothelial cells like HUVECs, HAECs etc, as well immortalized endothelial cell lines like ECV 304. I have used the BD Matrigel™ Matrix extensively for "in-vitro angiogenesis assays" to screen potential anti-angiogenic compounds. In spite of its few drawbacks, I have found it to be an excellent product for my studies attempting to gain insight into the angiogenic pathways underlying neoplasia.
Piyali Dasgupta
Postdoctoral Research Fellow
Department of Pathology
College of Physicians and Surgeons (14-460)
Columbia University, New York