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. 2019 Feb 15;11(2):231. doi: 10.3390/cancers11020231

Figure 2.

Figure 2

Upregulation of iNOS/NO in photodynamically-stressed glioblastoma cells confers resistance to photokilling. U87 or U251 cells at ~60% confluency were dark-incubated with 1 mM ALA for 30 min in serum-free medium, irradiated with broad-band visible light, then switched to serum-containing medium and dark-incubated for various periods. Where indicated, 25 µM 1400W (W) or cPTIO (cP) was introduced immediately after irradiation and kept at the same concentration throughout. (A) MTT-assessed U87 viability 20 h after ALA/hν exposure in absence vs. presence of W or cP; n = 3. (B) Annexin V-FITC-assessed U87 apoptosis 4 h after indicated treatments (CPT: camptothecin); n = 3, * p < 0.05 vs. ALA/hν. (C) Immunoblot of U87 iNOS (a) and nNOS (b) at indicated post-hν times. Numbers below NOS bands indicate intensity relative to actin and normalized to dark (ALA-alone) control (DC). (D) Immunoblot of iNOS in U251 cells at indicated post-hν times. Adapted from Reference [32].