3D in vitro co-culture disc for spatiotemporal image analysis of cancer–stromal cell interaction

Assessing phenotypic changes in both cancer cells and surrounding cells, which construct the tumour microenvironment, is essential for understanding the role of bi-directional communication among cells in the tumorigenic process. Here, a 3D in vitro cancer-stroma co-culture system, a co-culture disc, was reported for the spatiotemporal image analysis of cancer-stromal cell interactions. Due to their centre-open disc structure, the lung cancer A549 spheroids could be co-cultured with a high concentration of fibroblasts, without gel shrinkage in the long term (>1 month). In the co-culture disc, some populations of applied normal human lung fibroblasts showed morphological and phenotypic changes into activated myofibroblasts (AMFs) with high expression of myo-fibrotic α-smooth muscle actin fibre in the cell, which is a well-known feature of cancer-associated fibroblasts. The AMFs appeared heterogeneously at the boundary of cancer spheroids, which could not be detected by standard mass analysis using a quantitative RT-qPCR system, and they led to A549 cancer cell migration. In addition, the effects of oncogenic or medicinal additives were quantitatively assessed by combining co-culture discs with image analysis. This system provides a new potential technique to analyse the complicated crosstalk among cancer tissue-constructing cells during the tumorigenic process and provides insight into applications for the quantitative evaluation of substances inducing tumorigenesis as well as drugs to prevent and inhibit cancer progression.