Specific labeling of stem cell activity in human colorectal organoids using an ASCL2-responsive minigene

Organoid technology provides the possibility to culture human colon tissue and patient-derived colorectal cancers (CRC) while maintaining all functional and phenotypic characteristics. Labeling of human colon stem cells (CoSCs), especially in normal and benign tumor organoids, is challenging and therefore limits usability of multi-patient organoid libraries for CoSC research. Here, we developed STAR (STem cell Ascl2 Reporter), a minimal enhancer/promoter element that reports transcriptional activity of ASCL2, a master regulator of LGR5+ CoSC fate. Among others via lentiviral infection, STAR minigene labels stem cells in normal as well as in multiple engineered and patient-derived CRC organoids of different stage and genetic make-up. STAR revealed that stem cell driven differentiation hierarchies and the capacity of cell fate plasticity (de-differentiation) are present at all stages of human CRC development. The flexible and user-friendly nature of STAR applications in combination with organoid technology will facilitate basic research on human adult stem cell biology. Overall design: Cells from different colon organoid types were FACS sorted for stem STemness Ascl2 Reporter activity for transcriptome profiling by RNA-seq.

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Oost KC, van Voorthuijsen L, Fumagalli A, Lindeboom RGH, Sprangers J, Omerzu M, Rodriguez-Colman MJ, Heinz MC, Verlaan-Klink I, Maurice MM, Burgering BMT, van Rheenen J, Vermeulen M, Snippert HJG