Figure 4. Glioma cells grown on poly-D-lysine/laminin-coated plates maintain the response to irradiation and forskolin treatment.

Heatmaps showing the results of quantitative RT-PCR for the neuronal markers in HK-374 glioma spheres treated with radiation (a single dose of 4 Gy) in the presence or absence of forskolin (10 μM) for 24 hours and 5 consecutive days under suspension culture in ultra-low adhesion plates (A). Neuron-like cell morphology changes in HK-374 glioma spheres grown on Poly-D-Lysine/Laminin coated plates upon combine treatment of radiation and forskolin for 5, 14 and 21 days (black arrows showed the elongation of cell bodies) (B). Cells could be maintained under these culture conditions for 21 days with persisting significantly increased β3-tubulin, and neurofilament light chain marker expression after irradiation and forskolin treatment (C/D). Additionally, we found a significant increase of the microglia marker TMEM119 after treatment with radiation and forskolin (E). The significant increase in neuronal marker expression was confirmed in Western blots (F-H). All experiments have been performed with at least 3 biological independent repeats. p-values were calculated using One-way ANOVA for C-F, G, H; The p-values listed in the heatmaps were from the comparison of RT + Forskolin to RT + DMSO. * p-value < 0.05, ** p-value < 0.01, *** p-value < 0.001, **** p-value < 0.0001.