Figure 2.

Inhibition of NFκB regulated genes by cisplatin and curcumin. A) Total protein lysate extracted from CAL27 and UM-SCC1 cell lines treated with cisplatin (10 μM or 20 μM) or liposomal curcumin (100 μM) or a combination of cisplatin (10 μM) and liposomal curcumin (100 μM) were analyzed by PAGE. Untreated cells and those treated with empty liposomes (100 μM) or empty liposomes and cisplatin (10 μM) served as controls. Since CAL27 cells expressed lower level of cyclin D1, cells were also pre-treated with TNFα. Empty liposomes do not show any inhibitory effect on the expression of cyclin D1 or phospho-IkBα. However, reduced protein expression is observed with cisplatin or curcumin. The inhibitory effect of cisplatin-curcumin combination reaches that of 20 μM cisplatin, indicating usefulness of the non-toxic curcumin as a chemotherapeutic drug for adjuvant therapy. B) Hybridization of CAL27 total protein lysates to IkBα and IKKβ antibodies shows decreased expression of these two proteins in cells treated with cisplatin (20 μM) or liposomal curcumin (100 μM). C) immunofluorescence analysis of CAL 27 cells with TNFα shows increased expression of phospho-IkBα, indicating enhanced phosphorylation through IKKβ. This expression is not affected by the addition of liposomes. However, a decrease in phospho-IkBα expression level is visualized with the addition of curcumin. D) β-galactosidase assay demonstrates increased blue staining, indicating senescence-mediated cell death in cisplatin treated CAL27 cells. All pictures represent 100X magnification.