fig4
![Negative effects of tumor cell nitric oxide on anti-glioblastoma photodynamic therapy](https://image.oaes.cc/c29c2a00-a27e-4841-8f0e-5610add59524/3831.fig.4.jpg)
Figure 4. Some upstream evens that signal for greater iNOS transcription in ALA/light-treated glioblastoma U87 cells. A: post-irradiation upregulation of p65-ack310; DC: ALA-only dark control; B: post-irradiation upregulation of phosphorylation-activated p300 (p-p300); C: stimulation of p300 and p65 association in photostressed cells, as assessed by immunoprecipitation assay, using monoclonal p300 and p65 antibodies; D: time-dependent down-regulation of Sirt1 in photostressed cells, as assessed by immunoblot analysis. ALA: 5-Aminolevulinic acid; NO: nitric oxide; iNOS: inducible NO synthase; post-hν: post-irradiation; Sirt1: sirtuin 1 (Reproduced from Ref. 59, with permission)