Figure 6.

Effects of heme oxygenase-1 (HO-1) inhibition by HO-1 small hairpin RNA (shRNA).

Notes: HuCC-T1 cells were transfected with control shRNA or HO-1 shRNA. Twenty-four hours after transfection, cells were treated with 5-aminolevulinic acid ([ALA] 3 mM) and/or celecoxib (10 μM) for 4 hours and irradiated with 0.25 or 0.75 J/cm². (A) Cell extracts were subjected to immunoblot analysis. The intensity of western band was obtained by calculating HO-1/β-actin using the Image J program (n = 3). (B) Cell survival was determined by the MTT assay. (C) Cells were washed with phosphate buffered saline and stained with hematoxylin-eosin solution (n = 3). (D) The collected pellets were stained with propidium iodide and fluorescein isothiocyanate-annexin V and analyzed by flow cytometry. The right graph of panel D shows flow cytometry results for combined treatment with ALA and celecoxib (n = 3). Data are represented as mean ± SEM. * denotes P < 0.05; ** denotes P < 0.01; and *** denotes P < 0.001.

Abbreviations: ALA, 5-aminolevulinic acid; cele, celecoxib; HO-1, heme oxygenase-1; shCTR, control shRNA; shHO-1, HO-1 shRNA.