Figure 4

Curcumin treatment alters the expression of pro-survival and pro-apoptosis related proteins. (A) Curcumin decreases the expression of Bcl2 family of pro-survival proteins during 6 hr pre-treatment. A2780CP cells were treated with 20 μM curcumin for 6 hrs and protein lysates were collected and analyzed by immunoblotting for Bcl-xl, Mcl-1 and β-actin. Appropriate bands were quantified by densitometry, normalized to β-actin, scaled to the DMSO control and expressed as relative expression levels (number beneath the blots). (B) Curcumin pre-treatment followed by low dose cisplatin increases percent of Annexin V positive cells. A2780CP cells treated as indicated with vehicle (DMSO), curcumin (20 μM) or cisplatin (5 μM) only or pre-treated with curcumin (20 μM) followed by cisplatin (5 μM) treatment. After 48 hrs, adherent and attached cells were stained with Annexin V-PE and analyzed by Flow Cytometry. Representative histograms are shown for 1 of 3 similar experiments. (C and D) Curcumin pre-treatment promotes the induction of apoptosis by cisplatin. A2780CP cells were treated as indicated for a total of 48 hrs and protein lysates were collected and analyzed by immunoblotting for caspase 9 and PARP. (D) Bands for full length and cleaved PARP were quantified by densitometry, normalized to β-actin and calculated as a ratio of cleaved PARP to full length PARP. Data represent mean of 3 repeats for each treatment (Mean ± SE, * p < 0.017, compared to curcumin only).