Metastasis-related characteristics of tumor spheres derived from human colorectal cancer cell line HCT116

TLDR: HCT116 tumor spheres are enriched with CD133+ cells and the surface marker CD133 is located on the cell membrane, suggesting that the cell spheres may get higher metastatic ability through epithelial-mesenchymal transition.

Abstract: Objective: To generate tumor spheres from colorectal cancer cell line HCT116 in serum-free medium (SFM) and to observe the location of the cancer stem cell surface marker CD133 as well as the ratio of CD133+ cells so as to investigate the possible relationship between the epithelial-mesenchymal transition and metastatic ability of tumor spheres. Methods: Human HCT116 colorectal cancer cells were cultured in SFM supplemented with cell growth factors. The location of cancer stem cell marker CD133 in tumor spheres was observed by confocal laser scanning microscopy, and the content of CD133+ cells in tumor spheres was detected by flow cytometry (FCM). Transwell chamber assay, immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR) were applied to examine the metastatic ability of tumor spheres in vitro and the expressions of epithelial-mesenchymal-related key markers. Results: The surface marker CD133 was located on cell membrane, and the content of CD133+ cells was significantly increased in HCT116 tumor spheres. The expressions of mesenchymal markers N-cadherin and Vimentin were highly elevated, while the expression of epithelial marker E-cadherin was reduced. The metastatic ability of cell sphere was higher than that of monolayer cells. Conclusion: HCT116 tumor spheres are enriched with CD133+ cells. The surface marker CD133 is located on the cell membrane. The cell spheres may get higher metastatic ability through epithelial-mesenchymal transition. DOI:10.3781/j.issn.1000-7431.2011.11.004