Fig. 5

CCL9 promotes the expansion of Elf5 positive/ERα negative luminal progenitor cells. A. Effect of murine CCL9 recombinant protein (100 ng/mL) on organoid culture of LP cells sorted from the mammary glands of 6-week-old female virgin mice treated for up to 12 days. PBS-treated organoids are referred to as control. Red arrowheads indicate filopodia-like structures. n = 3 per group. Scale bar: 275 μm. B. Quantification of luminal outgrowths (branching) in PBS vs. CCL9 treated LP cell-derived organoid on day12 of treatment. FOV: Field of view. Number of FOV = 6. C. LP cells isolated from AI and GI glands harvested on day 56 PPM are grown as organoids and imaged after 14 days in culture. n = 3 per group. Scale bar: 150 μm. D. Quantitative RT-PCR analysis of Elf5 and E. Esr1 expressions in organoids either treated with PBS or CCL9 protein for 12 days as described in Fig. 5A. CK18 expression was used as normalizer. n = 3 per group. ns: non-significant, **p-value > 0.01