Effects of tetrandrine and caffeine on cell viability and expression of mammalian target of rapamycin, phosphatase and tensin homolog, histone deacetylase 1, and histone acetyltransferase in glioma cells

ObjectiveKnowledge about the mechanisms underlying the cytotoxicity of tetrandrine and caffeine on glioma cells is limited. The primary objective of this study was to assess the expression of mammalian target of rapamycin (mTOR), phosphatase and tensin homolog (PTEN), histone deacetylase 1 (HDAC1), and histone acetyltransferase (p300) in RT-2 glioma cells treated with caffeine and/or tetrandrine.Materials and methodsThe cell viability and expression of mTOR, PTEN, HDAC1, and p300 in RT-2 glioma cells were assayed after treatment with caffeine and/or tetrandrine for 48 hours.ResultsThe cell viability of RT-2 cells decreased significantly 48 hours after treatment with tetrandrine (5 μM) alone and tetrandrine (5 μM) combined with caffeine (0.5 mM or 1 mM), but not caffeine (0.5 mM or 1 mM) alone. The protein levels of mTOR, PTEN, and HDAC1 did not appear to change significantly after treatment with caffeine (0.5 mM or 1 mM) alone, tetrandrine (5 μM) alone, or their combinations. However, p300 increased significantly after treatment with caffeine (0.5 mM or 1 mM) alone, tetrandrine (5 μM) alone, and their combinations.ConclusionTetrandrine and caffeine can increase glioma cell death additively possibly via increasing p300 expression.