Article

Recklessness as a hallmark of aggressive cancer.

Department of Molecular Oncology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto 606-8501, Japan.
Cancer Science (Impact Factor: 3.53). 12/2007; 98(11):1659-65. DOI: 10.1111/j.1349-7006.2007.00588.x
Source: PubMed

ABSTRACT Cancer recurrence after surgical treatment is a major concern for patients and doctors. Understanding what makes tumors prone to recurrence would be an important step toward its prevention. Accumulating evidence indicates that the level of membrane-associated protease regulator reversion-inducing cysteine-rich protein with Kazal motifs (RECK) expressed in tumor tissue is a good prognostic indicator in several common cancers. Certain members of the matrix metalloproteinase family are often upregulated in advanced cancers and are known to play important roles in tumor angiogenesis, invasion and metastasis. RECK negatively regulates several matrix metalloproteinases. Therefore, RECK itself may well be considered a promising tool or target molecule to be activated in cancer therapy. Here we review the recent advances in RECK research and discuss some of the important issues to be addressed in future studies.

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    ABSTRACT: Expression of a mesenchymal phenotype is often associated with invasive/metastatic behaviors of carcinoma cells. Acquisition of a mesenchymal phenotype by a carcinoma cell is known as epithelial-mesenchymal transition (EMT). The membrane-anchored matrix metalloproteinase-regulator RECK is abundant in normal mesenchymal cells. In aggressive carcinomas, however, RECK expression is often downregulated. This apparent paradox prompted us to clarify the relationship between EMT and RECK. We found that TGFβ-induced E-cadherin downregulation, a hallmark of EMT, is accompanied by RECK-upregulation in a non-tumorigenic epithelial cell line (MCF10A). In contrast, the loss of E-cadherin expression is uncoupled from RECK-upregulation in carcinoma-derived cell lines (MCF7, MDA-MB-231, and A549). When RECK was artificially expressed in A549 cells, it showed little effect on EMT but elevated the level of integrin α5 and attenuated cell proliferation and migration. These findings implicate RECK in the regulation of proliferation and migration of normal epithelial cells after EMT and suggest how the uncoupling between EMT and RECK-upregulation impacts on the fates and behaviors of carcinoma cells.
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