Curcumin Sensitizes Hepatocellular Carcinoma Cells to Radiation via Suppression of Radiation-Induced NF-κB Activity

Figure 3

The effects of curcumin on radiation-induced cytotoxicity, NF-κB activation, expressions of NF-κB downstream effector proteins, and loss of MMP in HCC cells (Huh7/NF-κB-luc2, Hep3B, and HepG2). Cells were treated with 30 μM curcumin for 24 hr, 10 Gy irradiation, and curcumin plus radiation, respectively. (a) The cell viability was evaluated with MTT assay. compared with that of the control; and compared with that of curcumin group. (b) The NF-κB activation was evaluated with IVIS50. a < 0.01 compared with that of the control; compared with that of radiation group. (c) NF-κB/DNA binding activity was determined by EMSA. (d) Expressions of NF-κB downstream effectors proteins (i.e., VEGF, MMP-9, XIAP, Bcl-2, and cyclin-D1) were determined with Western blot. (e) The detection of MMP by flow cytometry. compared with that of the control; compared with those of radiation and curcumin groups. (f) Huh7/NF-κB-luc2 cells were transfected with either IκBαM or empty vectors before irradiation. After irradiation, cells were incubated for 24 h and then assayed for MMP. . Ctrl: control, R: radiation, Cur: curcumin, and Comb: combination.

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