Data from Oligodeoxyribozymes That Cleave β-Catenin Messenger RNA Inhibit Growth of Colon Cancer Cells via Reduction of β-Catenin Response Transcription

Abstract

<div>Abstract<p>Abnormal regulation of Wnt/β-catenin signaling followed by increased levels of the β-catenin protein have been identified in enhanced cellular proliferation and development of colon polyps and cancers. To inhibit β-catenin gene expression in colon cancer cells, RNA-cleaving oligodeoxyribozyme (DNAzyme) was employed to destroy the β-catenin mRNA. We designed a strategy to identify the cleavage sites in β-catenin RNA with a pool of random sequences from a DNAzyme library and identified four potential DNAzyme-working sites. DNAzymes were constructed for the selected target sites and were tested for the ability to cleave β-catenin RNA. When introduced into the cells, the selected DNAzymes decreased the expression of β-catenin significantly as well as its downstream gene, <i>cyclin D1</i>. Additionally, we designed short hairpin RNA that targets the same cleavage site for the selected DNAzyme. The designed short hairpin RNA also inhibited β-catenin gene expression in colon cancer cells. Our studies show that RNA-cleaving DNAzymes and RNA interference targeted to β-catenin significantly reduced β-catenin–dependent gene expression, resulting in inhibition of colon cancer cell growth. These results indicate that the functional antisense oligonucleotides directed against β-catenin might have potential as a therapeutic intervention to treat colon cancer. Mol Cancer Ther; 9(6); 1894–902. ©2010 AACR.</p></div>