The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1999
Filed:
Jan. 07, 1998
Utrecht University, The Netherlands, US;
Abstract
The APC tumor suppressor protein binds to .beta.-catenin, a protein recently shown to interact with Tcf/Lef transcription factors. Here, the gene encoding a Tcf family member that is expressed in colonic epithelium (hTcf-4) a was cloned and characterized. hTcf-4 transactivates transcription only when associated with .beta.-catenin. Nuclei of APC.sup.-/- colon carcinoma cells were found to contain a stable .beta.-catenin-hTCF-4 complex that was constitutively active, as measured by transcription of a Tcf reporter gene. Reintroduction of APC removed .beta.-catenin from hTcf4 and abrogated the transcriptional transactivation. Constitutive transcription of TCF target genes, caused by loss of APC function, may be a crucial event in the early transformation of colonic epithelium. It is also shown here that the products of mutant APC genes found in colorectal tumors are defective in regulating .beta.-catenin/Tcf-4 transcrpitional activation. Furthermore, colorectal tumors with intact APC genes were shown to contain subtle activating mutations of .beta.-catenin that altered functionally significant phosphorylation sites. These results indicate that regulation of .beta.-catenin is critical to APC's tumor suppressive effect and that this regulation can be circumvented by mutations in either APC or .beta.-catenin.