Genome-wide transcriptional effects of Pregnancy-Induced Non-coding RNA (PINC)

Pregnancy-Induced Non-Coding RNA (PINC) is upregulated in alveolar cells of the mammary gland during pregnancy and persist in alveolar cells that remain in the regressed lobules following involution. Here, we show that in the post-pubertal mouse mammary gland, mPINC expression increases throughout pregnancy and then declines in early lactation, when alveolar cells undergo terminal differentiation. Accordingly, mPINC expression is significantly decreased when HC11 mammary epithelial cells are induced to differentiate and produce milk proteins. This natural reduction in mPINC levels may be necessary for lactation, as overexpression of mPINC in HC11 cells blocks lactogenic differentiation, while knockdown of mPINC enhances differentiation. HC11 mammary epithelial cells, with or without knockdown or over-expression of PINC, and with or without treatment by differentiation-inducing agents, were profiled for gene expression.