Pluripotent cells can be directed to differentiate in vitro for disease modeling, tumorigenesis studies, and drug screening (Cohen and Melton, 2011). However, directed differentiation protocols can be lengthy and laborious, and are thus not amenable to high-throughput screening. Image-based chemical screening using cultured zebrafish blastomere pluripotent cells establishes a system that can be used in a high-throughput fashion and takes advantage of chemical genetics approaches with zebrafish. Here, we used this zebrafish embryo cell culture system to screen for modulators of c-myb: GFP–expressing cell populations maintained within heterogeneous cultures. Identifying chemical suppressors could provide new therapies for tumors driven by MYB, thereby demonstrating the benefits of this pluripotent zebrafish embryo cell culture to understand and exploit oncogenic regulatory networks and for assays of tumor formation in various experimental settings.

Adenoid cystic carcinoma (ACC) is a malignant neoplasm arising from secretory glands, commonly the salivary glands in the head and neck, and is characterized by slow and unpredictable growth that is often fatal (Coca-Pelaz et al., 2015). ACC has a propensity to spread along nerve fibers and metastasize to other locations in the body. Recurrent MYB translocations have been identified in the majority of ACCs, which are characterized by overexpression of MYB and MYB targets (Persson et al., 2009; Ho et al., 2013; Mitani et al., 2016). MYB is a master transcrip-