Functional Characterization of Ionotropic Receptor P2x7 in Gl261 Cells

AUTHORS: Thandiswa Mdluli and Suely Soeiro
FACULTY: Dr. Luke Daniels
DEPARTMENT: Biology

ABSTRACT

Glioblastoma multiforme (GBM) is an aggressive grade iv brain cancer. Despite progressive improvements in the standard multimodal treatment protocols, prognosis remains poor, with an average survival time of 12 - 18 months. There is therefore a need to investigate effective anti-cancer therapeutics. Ionotropic receptors are a class of proteins that are being actively explored as potential drug targets because their activation leads to a cytotoxic influx of ions into the cell. The ionotropic ATP receptor P2X7 has been shown to be expressed in GBM cells and therefore represents a receptor that can be exploited for therapeutic use. Though P2X7 protein and mRNA has been detected in GBM cells, it remains unclear whether it contributes to functional detection of ATP. Therefore, we have tested the hypothesis that pharmacological activation of P2X7 leads to increased intracellular calcium. To investigate this, we used the calcium-sensitive dye fura-2 to measure P2X7 activity in GL261 cells, a murine glioma cell line known to recapitulate glioma characteristics in culture. Cells were exposed to P2X7 agonists in both the presence and absence of a pharmacological inhibitor of P2X7, o-ATP. Our results indicate a 30% decrease in functional P2X7 responses in the presence of o-ATP, leading us to conclude that P2X7 is partially responsible for ATP detection and subsequent calcium influx. These results contribute to an active area of research exploring drug treatments that seek to extend and improve the quality of life for glioblastoma patients.