Short hairpin RNA targeting β-catenin suppresses cell proliferation and induces apoptosis in human gastric carcinoma cells

Abstract

Objective. Aberrant activation of Wnt/β-catenin signaling is involved in various cancers, including human gastric cancer. Here we investigate the role of Wnt/β-catenin signaling in regulating gastric cancer cell apoptosis. Material and methods. Expression of β-catenin was investigated after transfection with β-catenin short hairpin RNA (shRNA) in gastric cancer cells by Western blotting and immunofluorescence analysis. β-catenin/T-cell factor transcriptional activity was also investigated by using a luciferase reporter assay. Next, the effects of β-catenin shRNA on cell proliferation and apoptosis were evaluated by the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide assay and flow cytometric analysis. To investigate the precise mechanism of these effects, a comprehensive analysis was performed using a cDNA microarray. Results. shRNA targeting β-catenin resulted in a significant decrease in β-catenin expression, and its nuclear localization and cell proliferation. Meanwhile, increased cell apoptosis was confirmed. The comprehensive analysis showed that shRNA targeting β-catenin upregulated 26 apoptosis-related genes (including PERP, TRAF3, PDCD2, TNFRSF25, AKT2 and YWHAZ) and downregulated 48 apoptosis-related genes (including MALT1, IRAK1, TNFAIP3, PPP1R13L, TRIP and YWHAB) in gastric cancer cells. Pathway analysis suggested that the nuclear factor-kappaB pathway was involved in β-catenin knockdown-induced apoptosis. Conclusions. Attenuation of β-catenin by shRNA resulted in suppressed cell proliferation and apparent apoptosis, suggesting that β-catenin may be a target for therapy of gastric cancer.

Key Words::

• Apoptosis
• β-catenin
• gastric cancer
• microarray
• short hairpin RNA

Acknowledgements

We thank Professor Chun Lu for his help in preparing the manuscript. We are also thankful to Dr. Bart. Williams for providing the TOPflash and FOPflash reporter plasmids. The authors report no conflicts of interest.

Notes