1. Elevated expression of axin2 and hnkd mRNA provides evidence that Wnt/β-catenin signaling is activated in human colon tumors
- Author
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Ann B. Jefferson, Jaime Escobedo, Christoph Reinhard, Doreen Sakamoto, Dong Yan, Roger H. Caothien, Lewis T. Williams, Lida Guo, Filippo Randazzo, Vivien W. Chan, Marion Wiesmann, Michael Rohan, John Fuller, Wendy J. Fantl, and Pablo Garcia
- Subjects
DNA, Complementary ,Beta-catenin ,Adenomatous polyposis coli ,Molecular Sequence Data ,Biology ,Cell Line ,Axin Protein ,Proto-Oncogene Proteins ,medicine ,AXIN2 ,Humans ,RNA, Messenger ,Promoter Regions, Genetic ,beta Catenin ,DNA Primers ,Oligonucleotide Array Sequence Analysis ,Multidisciplinary ,Base Sequence ,Wnt signaling pathway ,Proteins ,Cancer ,Transfection ,Zebrafish Proteins ,Biological Sciences ,medicine.disease ,Molecular biology ,Repressor Proteins ,Wnt Proteins ,Naked cuticle ,Cytoskeletal Proteins ,Cell culture ,Colonic Neoplasms ,Trans-Activators ,biology.protein ,Signal Transduction - Abstract
Genetic studies have identified mutations in key regulators of the Wnt/β-catenin pathway in a variety of cancers, most frequently in colon cancers. However, whether the pathway is activated in clinical cancer samples is not easily determined, and therefore it is useful to find markers that could be surrogates to show activation of the Wnt/β-catenin pathway. Gene expression profiles were analyzed in SW620, a colon cancer cell line in which β-catenin levels are stabilized as a consequence of truncated adenomatous polyposis coli and were compared with profiles of the same cells transfected with antisense oligodeoxynucleotides. Treatment of cells with β-catenin antisense oligodeoxynucleotides resulted in a decrease in the levels of axin2 and human naked cuticle ( hnkd ) mRNAs. Interestingly, the proteins encoded by both of these mRNAs are known inhibitors of the β-catenin pathway. In 30 human cell lines derived from different origins, axin2 and hnkd were expressed only in human colon cancer cell lines that are known to have activating mutations in the Wnt/β-catenin pathway. Further, levels of both axin2 and hnkd mRNA were also found to be elevated in about 65% of laser microdissected cells from human colon tumors compared with laser microdissected cells of normal morphology from the same patient samples. The increased expression of axin2 and hnkd correlated with truncations in adenomatous polyposis coli in the same patient samples. These results reveal that it is possible to detect activation of a carcinogenic pathway in human cancer samples with specific markers.
- Published
- 2001