Glioblastoma multiforme (GBM) is one of the most invasive forms of malignant brain tumors. By the time the tumor is removed from a region in the brain, the cancer cells rapidly metastasize and spread throughout the brain. Common treatment procedures such as chemotherapy and radiotherapy are not completely effective due to the aggressive nature of the tumor invasion. Therefore, many treatments also target the migratory properties of the tumor cells. Several proteins (focal adhesion kinase, paxillin, vinculin) are over-expressed in the extracellular matrix of the tumor microenvironment and help the GBM cells proliferate through the brain tissues. A treatment approach is to target these proteins and hopefully prevent -or at least reduce- the tumor cell invasion.
Studying this type of a cancer model is tricky. Most of the work that has been done in the traditional 2-dimensional cell culture environment cannot be translated into the 3-dimensional environment of the brain. We need a system that mimics the brain to realistically model the tumor cell growth and migration. As a part of my third rotation, I have been investigating the migration characteristics of GBM cells in tissue-engineered, 3-dimensional cell culture matrices that mimic the brain environment. The cells are grown in a collagen matrix containing components of the brain extracellular matrix (hyaluronan, astrocytes, etcetera) and the tumor cell migration is studied by tracking the focal adhesion proteins. However, this is not easy. Cancer cells have shown to modify their migratory patterns based on the physical conditions of the tumor microenvironment (Herrera-Perrez et al. 2015 Tissue Engineering Part A). This makes it more difficult to target the adhesion receptors to ultimately inhibit tumor invasion. It is also challenging to prevent the disruption of the cross-talk between the targeted receptor protein and other important signaling molecules during evaluation of the treatment procedures. Overall, new innovative strategies are required that focus on the diversity and adaptability of tumor cell invasion and migration.