Fig. 4

CD49f enriches for TIC activity in vitro and in vivo. a Tumors harvested from MMTV-PyMT+ females were harvest, digested, and stained with CD49f-FITC and CD24-PE antibodies prior to FACS sorting. CD49f⁺/CD24^High and CD49f^Neg/CD24^Low sorted cell populations were plated in sphere culture conditions to assay for sphere formation efficiency (SFE), or were transplanted by limiting dilution transplantation into female FVB/Nj recipients. a Each sorted cell population was plated at a density of 30,000 cells/well in 6-well format and the grand mean SFE ± SEM determined (n ≥ 8 wells per genotype; n = 3 independent experiments). The p-value was calculated by an unpaired Student’s t-test. b Comparison of changes in mean tumor volume over time when 50, 100 or 200 CD49f⁺/CD24^High or CD49f^Neg/CD24^Low sorted cells are transplanted into the cleared inguinal mammary fat pad to assay for TIC potential. The number of tumors that formed for each cohort is indicated in Table 1. c CD49f/CD24 expression was analyzed by FACS analysis of end-stage tumors derived from the transplantation of CD49f⁺/CD24^High or CD49f^Neg/CD24^Low sorted cells; data are representative of n ≥ 4 tumors/transplanted population. d Lung metastasis was evaluated in mice bearing tumors originating from CD49f⁺/CD24^High or CD49f^Neg/CD24^Low cell populations. A subset of mice in the 100-cell and 200-cell inputs were housed until tumors grew to a volume of ~500 mm³ at which time the tumors and lungs were harvested. The mean total number of lung metastases ± SEM present in H&E-stained paraffin sections is shown in the box-and-whisker plot; *p <0.05 by Student’s t-test; N.S. equals not significant