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Cancer Stem Cells
Article first published online: 27 NOV 2012
Copyright © 2012 AlphaMed Press
Volume 30, Issue 12, pages 2631–2644, December 2012
How to Cite
Kobayashi, S., Yamada-Okabe, H., Suzuki, M., Natori, O., Kato, A., Matsubara, K., Jau Chen, Y., Yamazaki, M., Funahashi, S., Yoshida, K., Hashimoto, E., Watanabe, Y., Mutoh, H., Ashihara, M., Kato, C., Watanabe, T., Yoshikubo, T., Tamaoki, N., Ochiya, T., Kuroda, M., Levine, A. J. and Yamazaki, T. (2012), LGR5-Positive Colon Cancer Stem Cells Interconvert with Drug-Resistant LGR5-Negative cells and are Capable of Tumor Reconstitution. STEM CELLS, 30: 2631–2644. doi: 10.1002/stem.1257
Authors contributions: H.Y.O and T. Yamazaki: conception and design, data analysis and interpretation, and writing manuscript, and final approval of manuscript; S.K., M.S., O.N., A.K., K.M., and T.O.: collection and assembly of data and data analysis and interpretation; Y.J.C., M.Y., E.H., Y.W., H.M., M.A., C.K., and T.W.: collection and assembly of data; T. Yoshikubo, N.T., and M.K.: data analysis and interpretation; S.F. and K.Y.: provision of study material (new antibodies); A.J.L.: other (support of manuscript). S. K. and H.Y.O. contributed equally to this article.
Disclosure of potential conflicts of interest is found at the end of this article.
First published online in STEM CELLSEXPRESS November 7, 2012.
- Issue published online: 27 NOV 2012
- Article first published online: 27 NOV 2012
- Accepted manuscript online: 18 OCT 2012 07:34AM EST
- Manuscript Accepted: 1 SEP 2012
- Manuscript Received: 19 APR 2012
- Cancer stem cells;
- Drug target;
- Experimental models;
- Monoclonal antibodies;
- Colon cancer;
The cancer stem cell (CSC) concept has been proposed as an attractive theory to explain cancer development, and CSCs themselves have been considered as targets for the development of diagnostics and therapeutics. However, many unanswered questions concerning the existence of slow cycling/quiescent, drug-resistant CSCs remain. Here we report the establishment of colon cancer CSC lines, interconversion of the CSCs between a proliferating and a drug-resistant state, and reconstitution of tumor hierarchy from the CSCs. Stable cell lines having CSC properties were established from human colon cancer after serial passages in NOD/Shi-scid, IL-2Rγnull (NOG) mice and subsequent adherent cell culture of these tumors. By generating specific antibodies against LGR5, we demonstrated that these cells expressed LGR5 and underwent self-renewal using symmetrical divisions. Upon exposure to irinotecan, the LGR5+ cells transitioned into an LGR5− drug-resistant state. The LGR5− cells converted to an LGR5+ state in the absence of the drug. DNA microarray analysis and immunohistochemistry demonstrated that HLA-DMA was specifically expressed in drug-resistant LGR5− cells, and epiregulin was expressed in both LGR5+ and drug-resistant LGR5− cells. Both cells sustained tumor initiating activity in NOG mice, giving rise to a tumor tissue hierarchy. In addition, anti-epiregulin antibody was found to be efficacious in a metastatic model. Both LGR5+ and LGR5− cells were detected in the tumor tissues of colon cancer patients. The results provide new biological insights into drug resistance of CSCs and new therapeutic options for cancer treatment. STEM CELLS 2012;30:2631–2644