Characterisation of a novel aspirin analogue in malignant glioma

Abstract

Gliomas are the most common intracranial brain tumours and are associated with poor prognosis and median survival time of less than 15 months from first diagnosis. Clinical and preclinical research has suggested a role for aspirin in the treatment or prevention of cancer, with a recent focus on the development of novel aspirin analogues. Established (U87 MG, 1321N1, GOS-3& SVG-p12) and primary cell lines (BTNW911 & BTNW914) were treated with the novel aspirin analogue PN517, aspirin and cisplatin for 24 and 48 hr at 0.1 and 1mM. Cells were subsequently harvested and cell cycle distribution determined by flow cytometry following PI (50 mg/ml) and RNAse (100 mg/ml) treatment, and apoptosis examined by flow cytometry following staining with annexin-V and PI (50 mg/ml), or the mitochondrial membrane potential marker JC-1 (5 mM). Migration was examined over 18 hr using scratch assay and Boyden chamber technique. A two-way ANOVA test was used to analyse the significance between treatments with significance set at p < 0.05. PN517 induced apoptosis in the primary and established cell lines with a similar efficacy to cisplatin following 24 hours treatment at 0.1 mM. The induction of apoptosis was also assessed over a period of 48 hours and it was found to be the predominant mode of cell death at both 0.1 and 1mM concentrations and at early time points, with necrosis being observed at higher drug concentrations and after 24 hours of drug treatment. Following 48 hours of treatment PN517 (1 mM) significantly increased the sub G1 phase apoptotic population as determined by cell cycle analysis and decreased both the G1 and G2/M phase populations when compared to control. Treatment with the aspirin analogue (0.1 mM) also reduced migration significantly when compared to control. The novel aspirin analogue PN517 induced apoptosis, caused cell cycle arrest and reduced migration in both primary and established glioma cell lines. These results show that PN517 has therapeutic potential in the treatment of glioma.