Figure 4.

Functional heterogeneity of TcIC early and late in serial transplantation. (A) Tumor cells of early and late xenograft tumors, used for assessing genetic heterogeneity by WGS, were genetically barcoded and serially transplanted for three mouse generations. The contribution of individually marked cell clones was assessed by LAM-PCR and high-throughput sequencing. Relative contribution of individually marked cell clones to tumor formation in serial transplantation from P1 (B), P2 (C), and P3 (D). Each row displays one unique IS; each column displays one xenograft in serial transplantation. Dotted lines, 2° n/a. Arrows indicate serial transplantation steps. (E) Total number of ISs detected in serial transplants derived from X1 or X2 and corresponding mean GFP expression (green). (F) Relative contribution of functional tumor-initiating cell classes to early and late TcIC compartments in individual xenografts, and (G) on average, from three patients. Error bars represent the SEM. (A–G) All experiments were performed independently with tumor material from three CRC patients.