Figure 6

Light stimulation inhibited intracranial glioma growth in mice. (a) Schematic flowchart of the experiment of transplanting ChETA-transfected astrocytes or U87 glioma cells. (b) The intracranial transplantation region was illuminated by blue light after the mice were anesthetized. (c) Schematic drawing of illumination of intracranial glioma using blue light-emitting optical fiber. (d) The green-fluorescence distribution of transplanted astrocytes or U87 glioma cells in control group and ChETA+light group (arrow) at 1 week after the light stimulation. Bar=50 μm. (e) Schematic flowchart of the experiment of intracranial virus injection and light stimulation. (f) HE staining of the intracranial glioma 7 days post-U87 cell implantation. Bar=100 μm. (g) In situ expression of ChETA (green fluorescence) 7 days after injection of the virus into intracranial glioma. No fluorescence was observed in the control group. Bar=50 μm. (h) The percentage of the ChETA-positive glioma cells in ChETA and control groups, n=3. (i) GFAP immunofluorescence, ChETA expression, and HE staining of intracranial glioma sections 7 days post-virus injection. ChETA expression (green) was restricted to the tumor region; no green fluorescence was observed in the region outside the tumor. Bar=100 μm. (j) Mouse survival curves were plotted for the control, light, eYFP+light, ChETA, and ChETA+light groups. n=6 in each group. (k) HE staining of the intracranial glioma (arrow) in the control, light, eYFP+light, ChETA, and ChETA+light groups 2 weeks after the blue light illumination. High magnification (HE × 40) showed the disorganized histological appearance, decreased glioma cell density, and necrotic foci (arrow) in the ChETA+light group. Bars=1 mm (K, HE × 2); 50 μm (K, HE × 40). **P<0.01; ***P<0.001.The experiments were repeated for three times with similar results