Worldwide, colorectal cancer is the third most common type of cancer affecting both sexes. It has been proposed that a small subset of cancer cells (cancer stem cells) within each tumor is able to initiate tumor growth. In 2007, two research groups simultaneously identified a colon cancer stem cell population in human tumors by the use of CD133 expression. In the present study, we used a human colon cancer cell line, SW620, to analyze the cancer stem cell-like characteristics of CD133+ cells in vitro and in vivo. In vitro, CD133+ SW620 cells had a higher proliferative capacity, were more irradiation- and chemotherapy-resistant, and had a higher expression of -catenin compared with CD133− cells. Injections of either CD133+ or CD133− cells into the skin or rectal mucosa of NOD/SCID mice led to tumors; however, injection of CD133+ cells resulted in the formation of larger tumors. Tumors derived from injections of CD133− cells did not contain any CD133+ cells, whereas tumors derived from injections of CD133+ cells did contain CD133+ cells, suggesting self-renewing capability. However, the proportion of CD133+ cells in the newly formed tumors in vivo was lower than the proportion of CD133+ cells in vitro. In conclusion, the human colon cancer cell line, SW620, contains both CD133+ and CD133− phenotypes, and the CD133+ phenotype has characteristics consistent with those of cancer stem cells.
Department of Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
Publication date: June 1, 2010
More about this publication?
Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.