Observation on the Interactions Between Cancer Cell and Fibroblasts in 3D Cellular Spheroids by Using Light-Sheet Fluorescence Microscopy
Huei-Jyuan Pan (潘慧娟)1*, Yi-Hao Chen (陳一豪)1, Hsin-Han Hou (侯欣翰)2, Choung-Jen Yu (余忠仁)2, Chau-Hwang Lee (李超煌)1,3,4
1Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan
2Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
3Institute of Biophotonics, National Yang-Ming University, Taipei, Taiwan
4Department of Physics, National Taiwan University, Taipei, Taiwan
* presenting author:Huei-Jyuan Pan, email:cathypanhj@hotmail.com
Conventional two-dimensional (2D) monolayer cell cultures cannot rebuild a three-dimensional (3D) conformation with the architecture as that of a tumor in vivo [1]. Comparing 2D cell cultures with 3D cellular spheroids, the latter have features closer to those of a real tumor, such as cell-cell interaction, drug/molecule responses, and drug resistance [2]. The light-sheet fluorescence microscopy (LSFM) is suitable for the studies with cellular spheroids because of its low phototoxicity and 3D imaging capability.
We employed a microfluidic cell culture device to form co-culture cellular spheroids of lung fibroblast MRC-5 and lung cancer cell CL1-0. We used the co-culture spheroids as a platform to study the responses of cancer cells to various treatments, such as anti-cancer drugs and cigarette smoke extract (CSE) in 3D environment. We labelled the cancer cell and fibroblast with different dyes and employed LSFM to observe the spatial variations of the cells. We found that the combination of erlotinib and chloroquine, an autophagy inhibitor, showed a higher efficacy in killing the cancer cells in comparison with individual treatment. We also found that the CSE enhances cancer cell invasion mediated by fibroblast autophagy on 2D cell cultures.
The co-culture cellular spheroids combined with LSFM provide a convenient operation and observation platform for understanding cell-cell interactions and cellular responses to external treatments in 3D environments. Currently we are studying the effects of CSE on the cells in co-culture cell spheroids for understanding tumor growth, cancer cell invasion, and efficacy of anti-cancer drugs when a tumor is exposed in the cigarette smoke.

1. F. Pampaloni, E. G. Reynaud, and E. H. K. Stelzer, "The third dimension bridges the gap between cell culture and live tissue," Nat Rev Mol Cell Bio 8, 839-845 (2007).
2. X. Xu, M. C. Farach-Carson, and X. Q. Jia, "Three-dimensional in vitro tumor models for cancer research and drug evaluation," Biotechnology Advances 32, 1256-1268 (2014).

Keywords: cell spheroid , light-sheet microscopy, drug test