Figure 3.

HDACi enhance ERβ agonist LY500307 ability to reduce cell viability, colony formation, and invasion of GBM cells. (A) U251 and U87 cells were treated with indicated concentrations of LY500307 for 6 days in the presence or absence of panobinostat and romidepsin, and the cell viability was measured by MTT assay. (B) Primary GBM cells (GSC-111010) were treated with indicated concentrations of LY500307 for 6 days in the presence or absence of panobinostat or romidepsin, and the cell viability was measured by cell titer glow assay. (C) Effect of HDACi and LY500307 combination therapy on the cell survival of U251 (Pano 3.1 nM, Romi 1 nM, LY500307 5 µM) and U87 (Pano 12.5 nM, Romi 1 nM, LY500307 5 µM) cells was measured using colony formation assays (n = 3). Representative images of colonies are shown. Quantitation of colonies is presented. (D) Effect of HDACi and LY500307 combination therapy on cell invasion of U251 (Pano 12.5 nM, Romi 6.25 nM, LY500307 5 µM) and U87 (Pano 25 nM, Romi 6.25 nM, LY500307 5 µM) cells was determined using Matrigel Invasion Chamber assays. Representative images of invaded cells are shown and the number of invaded cells in 5 random fields was quantitated. Data are representative of 3 independent experiments (n = 3). Data are represented as mean ± SEM. *P < .05; **P < .01; ***P < .001; ****P < .0001. Statistical differences were examined using 1- and 2-way ANOVA. ANOVA, analysis of variance; ERβ, estrogen receptor β; GBM, glioblastoma; HDACi, histone deacetylase inhibitors.