Expression data from cancer stem cells derived from colorectal organoids

Colorectal cancer (CRC) is characterized by extensive intra-tumor heterogeneity. The cancer stem cell (CSC) theory may explain the mechanisms underlying the non-genetic heterogeneity and their characteristics of prominent plasticity are emerging to be elucidated. By tracking the spheroid formation and growth capacity of CRC CSCs with a single-cell resolution using an organoid culture, we revealed CSCs consisted of subpopulations with a dual (fast and slow)-growing pattern. When isolated, the slow-growing CSCs remained slow-growing and converted into dual-growing CSCs under certain conditions. The slow-growing cells showed low levels of MAP kinase activity and were resistant to a MEK1/2 inhibitor as well as chemo-drugs. The MSI1 gene was down-regulated in the slow-growing CSCs and played a key role in the transition between slow- and dual-growing CSCs. Isolation of slow-growing CSCs will provide a platform to elucidate the role of the plasticity of CSCs in drug resistance and tumor recurrence. To disclose the molecular characteristics of the CSC subclones with the distinct growth features, we analyzed the differentially expressed genes between the subgroups. The single cells from C45-1, C45-4SR and C45-4D subclones were cultured for 7 days and subjected to a microarray analysis.