Quantification of Disseminated PDX Cells

Following 8–14 weeks post orthotopic transplants, or ~8 weeks post i.c. or i.v. injections, primary tumors and peripheral tissues including lungs, lymph nodes, bone marrow, peripheral blood, and brains were harvested, dissociated to single cells and stained with fluorescently conjugated antibodies for CD298 (Biolegend, Cat. no. 341704) and MHC-I (eBioscience, Cat. no. 17-5957-82), and flow cytometry was used to analyze and quantify disseminated CD298⁺MHC-I⁻ PDX cells using the BD FACSAria Fusion cell sorter (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) as described previously^{26 (link)}. Primary tumor volumes were calculated using caliper measurements with the equation: volume of an ellipsoid = 1/2(length × width²). Whole-mount images of primary tumors and lungs were taken with a Leica MZ10 F modular stereomicroscope (Leica Microsystems, Buffalo Grove, IL, USA).