Microarray of primary human breast cells with or without Hippo kinases LATS1/2

Perturbation of the tightly regulated dynamic process of cell fate underlies many human diseases. The molecular mechanisms regulating breast cell fate in the hierarchically organized luminal and basal lineages of breast epithelium remain largely elusive. We performed a high-content confocal image-based shRNA screen for regulators of primary human breast cell fate. Inhibition of the Hippo kinases LATS was found to promote luminal fate and increase the number of progenitors, which is a paradox given that Hippo effectors YAP/TAZ have been associated with basal fate. Mechanistically, LATS loss increases the activities of YAP/TAZ and ERα, which in concert control breast cell fate via intrinsic and paracrine effects. Reduced LATS expression is found in breast cancers with a poor prognosis; this diminishes the sensitivity of ERα-positive- and increases the sensitivity of ERα-negative cancers to endocrine therapy. Thus, in this study we have unraveled crosstalk between Hippo and estrogen signaling and shown that LATS loss triggers expansion of luminal progenitors, the highly suspected cell-of-origin in most breast cancers. In this dataset, we provide microarray gene expression analysis of normal breast epithelial cells, freshly dissociated from reduction mammoplasties, in which LATS1/2 were knocked down comparing it to non-targeting control expressing breast cells. 11 samples were analyzed, 4 different donors (cells from reduction mammoplasties MP16, MP20, MP28 and MP33) in which LATS1/2 were knocked down by two different shRNAs (shLATS1_3 = LATS1 knockdown, shLATS2_3 = LATS1 and LATS2 double knockdown). Cells expressing a non-targeting shRNA were used as controls