(282c) Engineering Co-Culture of Cultured Glioblastoma Cells and Astrocytes to Study Cell-Cell Communication in GBM

Over 50% of all brain tumors are Glioblastoma Multiforme tumors (GBMs), with a median survival time of less than one year after diagnosis. These tumors are extremely aggressive, often having their own complex blood supply, contributing to the distress surrounding a brain tumor diagnosis. GBMs arise from astrocytes and are characterized by their invasion into surrounding tissues and recruitment of healthy tissues into tumor tissue. Astrocytes are the most abundant glial cell in the brain, primarily functioning to maintain ion homeostasis and modulate energy production through both direct and indirect communication. While recent studies indicate that glial cells in close proximity to the tumor microenvironment undergo alterations in their responses, the underlying mechanisms driving these changes remain largely unknown. Because of the complex nature of communication between these cell types, an accurate and representative in situ model is required to study this communication. We engineered a “patterned co-culture model” in order to control the interaction of astrocytes with GBM cells. We used poly(4-styrenesulfonic acid) (SPS) and poly(diallyldimethylammonium chloride (PDAC) polymers for selective adhesion of cells to create the patterned co-culture of GBMs and astrocytes. Unlike other synthetic and natural polymers, one of the greatest advantages of using SPS and PDAC is that they are biologically inactive material for GBMs and astrocytes, thus, do not alter the gene or protein expression profile of GBMs and astrocytes. Therefore, the results obtained using this method provides true interaction of GBMs with astrocytes in co-culture system without interference of interaction of cells with matrix. Our data shows that astrocytes regulate key pathways controlling tumor progression when co-cultured with GBMs. We observed significant upregulation in the energy utilization of GBM cells when grown in co-culture with astrocytes compared to GBM cells grown in monoculture. Altogether, our data show that physical contact between GBMs and astrocytes is critical to modulate the pathways responsible for metastasis and drug resistances in glioblastoma.