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. Author manuscript; available in PMC: 2021 Jul 8.
Published in final edited form as: Photochem Photobiol. 2020 Sep 14;97(1):180–191. doi: 10.1111/php.13321

Figure 5. Photodynamic induction of stress response gene expression in A375 malignant melanoma cells exposed to the combined action of UVA and FICZ.

Figure 5.

(a) Transmission electron microscopy (fold magnification: x 2,650) 6 h after FICZ-PDT (FICZ 100 nM; UVA 3.3 J/cm2). (b) Cells exposed to FICZ [10 nM] and blue light [LED 460 nm, 2.5 J/cm2]. Flow cytometric analysis of annexinV-FITC/propidium iodide (PI)-stained cells [24 h; n=3, mean ± SEM]. (c) Induction of cellular oxidative stress as examined 1 h after FICZ-PDT (conditions as in A) using flow cytometric analysis of DCF-DA stained cells. A representative experiment (out of at least three representative repeats) is displayed. (d) Loss of mitochondrial transmembrane potential (Δψm) as assessed by flow cytometric analysis of JC-1 stained cells, 1 h after FICZ (10 nM)/UVA (3.3 J/cm2) treatment. Numbers indicate percentage of cells inside the circle displaying intact Δψm [n=3, mean ± SD; (p<0.05)]. (e) Fpg-enhanced comet assay [FICZ: 100 nM; UVA: 3.3 J /cm2; 1 h] as performed in Fig. 4b. Bar graph displays relative comet tail moment [n=50 per group; mean ± SEM]. (f) FICZ-PDT-induced lysosomal impairment [FICZ 100 nM; UVA 3.3 J/cm2; 1 h] detected by LysoSensor green fluorescence microscopy [scale bar: 200 μm, 40 μm (overlay); n=85, mean ± SEM]. Bar graph displays quantitative analysis of LysoSensor fluorescence intensity [n=85, mean ± SEM]. (g) Cellular stress response induced by FICZ-UVA [FICZ 10 nM; UVA 3.3 J/cm2; top panel: 1h after irradiation; bottom panel: 6 h after irradiation] as determined at the protein level (immunoblot analysis; n≥3). For bar graph depiction, quantitative data analysis employed ANOVA with Tukey’s post hoc test; means without a common letter differ from each other (p<0.05).