Abstract
BACKGROUND Curcumin has well-known, explicit biological anti-tumor properties. The Wnt/β-catenin signaling pathway plays a central role in tumor cell proliferation and curcumin can regulate the Wnt/b-catenin signaling pathway of several carcinomas. The aim of this study was to investigate the impact of curcumin on the Wnt/β-catenin signaling pathway in human gastric cancer cells. MATERIAL AND METHODS We used 3 gastric cancer cell lines: SNU-1, SNU-5, and AGS. Research methods used were MTT assay, flow cytometry, clonogenic assay, annexin V/PI method, Western blotting analysis, tumor formation assay, and in vivo in the TUNEL assay. RESULTS Curcumin markedly impaired tumor cell viability and induced apoptosis in vitro. Curcumin significantly suppressed the levels of Wnt3a, LRP6, phospho-LRP6, β-catenin, phospho-β-catenin, C-myc, and survivin. Xenograft growth in vivo was inhibited and the target genes of Wnt/β-catenin signaling were also reduced by curcumin treatment. CONCLUSIONS Curcumin exerts anti-proliferative and pro-apoptotic effect in gastric cancer cells and in a xenograft model. Inhibition of the Wnt/β-catenin signaling pathway and the subsequently reduced expression of Wnt target genes show potential as a newly-identified molecular mechanism of curcumin treatment.