Sca1 + cells from Kras;p53-flox tumors are lung tumor-propagating cells.
(A) Representative FACS analysis of Kras;p53-flox tumor cells used for transplantation (top). Limiting dilution transplantation of the sorted cells indicated that the Sca1 + population was significantly enriched for TPCs (table). (B) Sca1- cell transplants yielded smaller, more diffuse lesions (left), whereas Sca1 + cell transplants yielded secondary tumors that recapitulated the histopathology of primary Kras;p53-flox tumors (right, compare to Figure 1C). (C) Immunofluorescence (IF) staining with antisera raised against SP-C (red), CCSP (green), and counterstain DAPI (blue) showed that primary Kras;p53-flox lung adenocarcinomas (left) are mainly composed of SP-C+ cells, a pattern recapitulated in secondary tumors from Sca1 + cell transplants (right). (D) Serial transplantation of secondary tumor cell populations revealed a lack of tumor formation from Sca1 - cells (left), in contrast to tertiary tumor development from Sca1 + cells (right). All images, 200× magnification. Scale bar = 100μM. See also Figure S1 and Table S1 for additional data.