Wilms' tumour gene 1 (WT1) as a target in curcumin treatment of pancreatic cancer cells

The transcription factor WT1 plays an important role in cellular proliferation and survival of various cancer cells, and is frequently expressed in pancreatic cancer. Curcumin has been shown to be a potentially effective agent in pancreatic cancer. In this context, the purpose of this study was to determine the role of WT1 in a curcumin-treated pancreatic cancer cell line. To study the effect of curcumin on the expression of WT1, we incubated the pancreatic cancer cell line PANC-1 with different amounts of curcumin. The expression of WT1 on mRNA and protein level was measured with real-time RT-PCR and Western blot analysis. The incubation of the pancreatic cancer cell line PANC-1 with curcumin resulted in an inhibition of cellular proliferation as measured with MTT assay. The expression of WT1 on mRNA and protein level was significantly down-regulated in a concentration-dependent manner after treatment with curcumin. The WT1 mRNA levels were decreased by 20%, 25%, 40%, 78% and 88% in response to 10, 20, 30, 40 and 50 mu M curcumin. The use of small inhibitory RNA (siRNA) targeting WT1 down-regulated the expression of WT1 about 90%. Combined treatment with curcumin and siRNA targeting WT1 resulted in a significant inhibition of cell proliferation compared to curcumin-treated cells alone. In conclusion, WT1 is involved in cellular proliferation of PANC-1 cells. Targeting WT1 gene expression with siRNA may enhance the efficacy of curcumin to inhibit cell proliferation. (C) 2008 Elsevier Ltd. All rights reserved.