PO02CHARACTERISATION OF GLIOBLASTOMA METABOLISM IN-VITRO: A COMPARISON BETWEEN A CELL LINE AND PRIMARY CULTURES

Abstract

INTRODUCTION: Characterisation of glioblastoma (GBM) metabolism is important clinically. The extent to which well-characterised cell lines represent tumour metabolism is poorly described. This study aimed to compare metabolic biomarker expression patterns between a commonly used cell line (U87-MG) and primary GBM cells, in two and three dimensional culture systems. METHOD: U87-MG and primary GBM cells were cultured in serum containing media. Multicellular tumour spheroids were produced by culturing cells in hanging droplet media. Immunofluorescence and fluorescence intensity quantification were used to assess the expression patterns of the following biomarkers: carbonic anhydrase 9 (CA9), glucose transporter 1 (GLUT1), monocarboxylate transporter 4 (MCT4) and glial fibrillary acidic protein (GFAP, control). Independent t-tests (t-t) were used to compare groups. RESULTS: In monolayer culture, CA9 expression was significantly greater in the U87-MG cell line (t-t, t = 3.417, p = 0.012), though GLUT1 (t-t, t = 1.046, p = 0.354) and MCT4 (t-t, t = 0.956, p = 0.393) were similarly expressed. The cell line was also found to be GFAP negative in contrast to primary cultures (t-t, t = 4.323, p = 0.012). In U87-MG spheroids, MCT4 expression was relatively greater in the outermost regions (t-t, t = 2.830, p = 0.047), though CA9 and GLUT1 expression was largely homogeneous. In contrast, primary GBM spheroids displayed gradients of increasing expression towards the outer regions, for all metabolic biomarkers. CONCLUSION: There were differences in metabolic biomarker expression between the cell line and primary GBM cells, in both culture systems. Cell lines should be used with caution to model GBM metabolism.