We characterized the cell type dynamics, composition, and transcriptome of early colorectal cancer liver metastases. This revealed that failure to establish cellular heterogeneity (i.e. presence of cancer stem cells and differentiated tumor cells) through YAP-controlled epithelial self-organization prohibits the outgrowth of micrometastases (Heinz et al., Cancer Res. 2022).
We have developed a new CRISPR pipeline that allows for fast, highly efficient, and error-free fluorescent genetic knock-ins in human organoids, both normal and cancer. The method is published and the palette of targeting vectors are publicly available from Addgene (Bollen, Hageman, et al., PLOS Biol, 2022).
We studied cell cycle kinetics in patient tumor organoids to map chromosomal instability in colorectal cancer via live-cell imaging of 3D organoids. We demonstrate a) that CIN is widespread in these cancers regardless of mutational landscape and b) that the combination of CIN levels and tolerance for mitotic errors shape karyotype diversification and heterogeneity landscapes. (Bolhaquiero, Ponsioen et al., Nat Genet 2019).
Regarding real-time analysis of signaling activity, we report the most optimal FRET biosensor to measure ERK activity in single-cells in real-time in patient organoids. Second, we developed strategies to measure quantitative signaling activity in 3D patient organoids. Third, we document how EGFR amplifies downstream ERK activity in human CRC, even in the presence of mutant KRAS or BRAF. The work explains EGFR as a successful drug target in widely applied combination therapies against CRC. (Ponsioen et al., Nat Cell Biol 2021).
Currently our work in ongoing to continue innovating our methodologies to assess single-cell signaling activities in real-time, and we work with sophisticated genetic knock-ins to address signaling function of diverse cell types in human tumors.
