Recently, the cell biology field has come to appreciate the dissimilarity between two- (2D) and three-dimensional (3D) environments in which cells routinely operate in vivo. Efficacy of most anti-cancer drugs have been evaluated in 2D environment but it must be desirable to evaluate it in 3D environment. We developed a novel 3D cell culture system named Cell-ableTM Oncology utilizing photo-sensitive materials that change to hydro-gel after UV irradiation and the optimized molecular design not to allow the cells adhere to the hydro-gel. In multi-well plates, the Cell-ableTM Oncology has type I collagen-coated cell-attaching areas on the each well surface, which are circle in 100 μm diameter and arrayed in every direction at 100 μm interval. Most cancer cells are able to attach these circles and grow to form spheroids of uniform size on the Cell-ableTM Oncology. In this study, we investigated the stem-like cell phenotypes of cancer spheroids formed on the Cell-ableTM Oncology in comparison with that of the 2D monolayer cells. Various cancer cell lines and patient-derived primary cancer cells proliferated and formed spheroids on the Cell-ableTM Oncology in serum-containing or serum-free media. In contrast to the 2D monolayer cells, the inside of the spheroids formed on the Cell-ableTM Oncology was hypoxic condition like in vivo tumor tissues in patients. The spheroids grown on the Cell-ableTM Oncology showed chemo-resistance against conventional chemotherapy, gemcitabine and paclitaxel compared with cells grown on collagen-coated 2D plates. The chemo-resistance of the spheroid cells was associated with high population of stem-kike cells (CD44high/CD24low) and high expression of mRNA for a stem cell marker, NANOG and an ABC transporter ABCG2. The combination of the Cell-ableTM Oncology and serum-free media showed the highest population of stem-like cells. These results indicate that the spheroids characterized by 3D structure formed on the ECM-coated surface and the hypoxic condition confer enriched the cancer stem-like cells. Thus, the spheroids on the Cell-ableTM Oncology could be suitable for research and development of drugs targeting cancer stem cells. The pharmacodynamic and pharmacokinetic studies using the cancer stem cell-rich spheroids could provide meaningful information relevant to clinical conditions.

Citation Format: Koichi Yokota, Tomoko Jomura, Emiko Ozeki, Takeshi Ikeya. Stem-like cell characteristics of cancer spheroids grown in a microfabricated cell array three-dimensional culture system Cell-ableTM Oncology. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3838. doi:10.1158/1538-7445.AM2013-3838