Fig. 1

Isolation and immortalization of stably propagated CD105^low and CD105^high CAF states. a Micrographs of hTERT-transduced crude CAF cultures from three primary breast cancer biopsies cultured to passage seven and immunoperoxidase-stained for α-sm actin (brown) and counterstained by hematoxylin for nuclei (blue). Scale bar = 50 μm. b Diagram of growth characteristics depicted as the cumulative population doublings (PDs) versus time (days) in CAF1 transduced with hTERT or empty vector. Note the extended life span of the hTERT-transduced CAF1 cells reaching > 40 PDs, whereas the empty vector-transduced cells refrain from doubling after ~ 20 PDs. c FACS dot plot of single-cell suspended CAF1 in passage eight labeled with a CD105 antibody and plotted versus forward scatter. Circles indicate the approximate CD105^low (CAF^low) and CD105^high (CAF^high) populations isolated for further subculture. d Micrographs of CAF1-derived CAF^low and CAF^high stained by immunoperoxidase against CD105 (brown) and with hematoxylin for nuclei (blue). Note the relative intense CD105 staining in CAF^high relative to CAF^low. Scale bar = 50 μm