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Journal of Oncology
Volume 2011, Article ID 609259, 16 pages
http://dx.doi.org/10.1155/2011/609259
Research Article

Bmi-1 Regulates Snail Expression and Promotes Metastasis Ability in Head and Neck Squamous Cancer-Derived ALDH1 Positive Cells

1Institute of Oral Biology and Biomaterial Science, Chung-Shan Medical University, Taichung 40201, Taiwan
2Department of Dentistry, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
3Division of Oral and Maxillofacial Surgery, Department of Stomatology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
4Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei 11217, Taiwan
5Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan
6Department of Surgery, Taipei Veterans General Hospital, Taipei 11217, Taiwan
7Department of Pharmacy Practice, Tri-Service General Hospital and 114 National Defense Medical Center, Taipei, Taiwan

Received 28 May 2010; Accepted 15 August 2010

Academic Editor: Eric Deutsch

Copyright © 2011 Cheng-Chia Yu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Recent studies suggest that ALDH1 is a putative marker for HNSCC-derived cancer stem cells. However, the regulation mechanisms that maintain the stemness and metastatic capability of HNSCC- cells remain unclear. Initially, HNSCC- cells from HNSCC patient showed cancer stemness properties, and high expression of Bmi1 and Snail. Functionally, tumorigenic properties of HNSCC- cells could be downregulated by knockdown of Bmi-1. Overexpression of Bmi-1 altered in expression property cells to that of cells. Furthermore, knockdown of Bmi-1 enhanced the radiosensitivity of radiation-treated HNSCC- cells. Moreover, overexpression of Bmi-1 in HNSCC- cells increased tumor volume and number of pulmonary metastatic lesions by xenotransplant assay. Importantly, knock-down of Bmi1 in HNSCC- cells significantly decreased distant metastases in the lungs. Clinically, coexpression of Bmi-1/Snail/ALDH1 predicted the worst prognosis in HNSCC patients. Collectively, our data suggested that Bmi-1 plays a key role in regulating Snail expression and cancer stemness properties of HNSCC- cells.