Co-culture of E and M cell-types synergistically increases mammosphere formation.

<p>(A) Representative light microscope images (10x objective) from mammospheres of 500 E5, 500 M5, and 500 E5 + 500 M5-derived mammospheres after two weeks suspension culture. (B) Total number of primary mammospheres derived from 500 (1x) or 1000 (2x) cells per cell-type seeded (from A) after two weeks suspension culture. (C) Total number of primary mammospheres grown from 500 (1x) freshly sorted CD24+/CD44-(E) cells, 500 CD24-/CD44+(M) cells, the co-culture, or 500 un-gated HP cells (‘all HP’) after two weeks of mammosphere formation. (D) Relative number of primary (seeded 2,000 cells per cell line per well) and secondary mammospheres from M4 grown with or without E5 cells or HP cells. After two weeks 10% of total number of dissociated cells from the indicated primary mammosphere samples were reseeded for secondary mammospheres and counted after one week. Mammospheres per well relative to that of M4-derived spheres are shown.