Analysis of an alternative human CD133 promoter reveals the implication of Ras/ERK pathway in tumor stem-like hallmarks

Molecular Cancer

Research

Norihisa Bizen¹  Tetsuya Taga²  Hiroshi Nishihara³  Taichi Kimura⁴  Lei Wang⁴  Kouichi Tabu⁵  Shinya Tanaka⁶  Ken Sasai⁷ 

[1] Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan;Division of Cell Fate Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto, Japan;Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan;Global COE Program "Cell Fate Regulation Research and Education Unit", Kumamoto University, 2-2-1 Honjo, Kumamoto, Japan;Division of Cell Fate Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto, Japan;Department of Translational Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Laboratory of Cancer Research, Department of Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Laboratory of Cancer Research, Department of Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Department of Stem Cell Regulation, Medical Research Institute, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, Japan;Global COE Program "Cell Fate Regulation Research and Education Unit", Kumamoto University, 2-2-1 Honjo, Kumamoto, Japan;Division of Cell Fate Modulation, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto, Japan;Laboratory of Cancer Research, Department of Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Department of Translational Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Laboratory of Cancer Research, Department of Pathology, Hokkaido University Graduate School of Medicine, Kita-15, Nishi-7, Kita-ku, Sapporo, Japan;Research Group for Human Cell Transformation, KAN Research Institute Inc., Kobe MI R&D Center, 6-7-3 Minatojima-Minamimachi, Chuo-ku, Kobe, Japan;

关键词: Side Population;    CD133 Gene;    Side Population Cell;    CD133 mRNA;    Magnetic Activate Cell Sorting;   

DOI  :  10.1186/1476-4598-9-39

 received in 2009-07-01, accepted in 2010-02-19,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundAn increasing number of studies support the presence of stem-like cells in human malignancies. These cells are primarily responsible for tumor initiation and thus considered as a potential target to eradicate tumors. CD133 has been identified as an important cell surface marker to enrich the stem-like population in various human tumors. To reveal the molecular machinery underlying the stem-like features in tumor cells, we analyzed a promoter of CD133 gene using human colon carcinoma Caco-2 and synovial sarcoma Fuji cells, which endogenously express CD133 gene.ResultsA reporter analysis revealed that P5 promoter, located far upstream in a human CD133 gene locus, exhibits the highest activity among the five putative promoters (P1 to P5). Deletion and mutation analysis identified two ETS binding sites in the P5 region as being essential for its promoter activity. Electrophoretic mobility shift assays demonstrated the specific binding between nuclear factors and the ETS binding sequence. Overexpression of dominant-negative forms of Ets2 and Elk1 resulted in the significant decrease of P5 activity. Furthermore, treatment of Fuji cells with a specific MEK/ERK inhibitor, U0126, also markedly decreased CD133 expression, but there was no significant effect in Caco-2 cells, suggesting cell type-specific regulation of CD133 expression. Instead, the side population, another hallmark of TSLCs, was dramatically diminished in Caco-2 cells by U0126. Finally, Ras-mediated oncogenic transformation in normal human astrocytes conferred the stem-like capability to form neurosphere-like colonies with the increase of CD133 mRNA expression.ConclusionsIn conclusion, the Ras/ERK pathway at least in part contributes to the maintenance and the acquisition of stem-like hallmarks, although the extent of its contribution is varied in a cell type-specific manner. These findings could help our comprehensive understanding of tumor stemness, and also improve the development of eradicative therapies against human malignancies.

【 授权许可】

Unknown   
© Tabu et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.