Change of the differentiation status of the luminal-type breast cancer organoids

Estrogen receptor (ER) expression in the luminal-type breast cancer organoids diminish after establishment of the organoid lines. Time course analysis revealed that the pattern of the decrease depended on each line and ignited by passage procedure in the culture. Using two lines of the luminal-type breast cancer, we compared the gene expression profiles between primary and passaged organoids by RNA sequencing. Because of the limitation of the amount of the primary cultured organoids, single sample was analyzed in each line. We found the differentiation status changed from luminal- to basal-like, and also Notch signaling is activated by passages.