文章基本信息

标题：Regulation of intracellular beta-catenin levels by the adenomatous polyposis coli (APC) tumor-suppressor protein.
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作者：S Munemitsu ; I Albert ; B Souza 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1995
卷号：92
期号：7
页码：3046-3050
DOI：10.1073/pnas.92.7.3046
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The APC tumor-suppressor protein associates with beta-catenin, a cell adhesion protein that is upregulated by the WNT1 oncogene. We examined the effects of exogenous APC expression on the distribution and amount of beta-catenin in a colorectal cancer cell containing only mutant APC. Expression of wild-type APC caused a pronounced reduction in total beta-catenin levels by eliminating an excessive supply of cytoplasmic beta-catenin indigenous to the SW480 colorectal cancer cell line. This reduction was due to an enhanced rate of beta-catenin protein degradation. Truncated mutant APC proteins, characteristic of those associated with cancer, lacked this activity. Mutational analysis revealed that the central region of the APC protein, which is typically deleted or severely truncated in tumors, was responsible for the down-regulation of beta-catenin. These results suggest that the tumor-suppressor activity of mutant APC may be compromised due to a defect in its ability to regulate beta-catenin.