Prolactin-induced protein (PIP) regulates proliferation of luminal A type breast cancer cells in a hormone-independent manner

RNA was extracted from cells using Aurum Total RNA kit from Bio-Rad Laboratories, Inc., Hercules, CA following the manufacturer’s recommendations. Gene expression profiling was performed using the BeadChip HumanHT-12 v4 Expression kit from Illumina®, which contains 47,231 gene-probes (Illumina® Inc., San Diego, CA). The raw signal intensities were imported and analyzed using the GenomeStudio® data software. After background subtraction and normalization, the signal intensity values were exported to the Partek® genomics expression analysis suite using “Partek's Report Plug-in” option in the GenomeStudio® software. Differentially expressed genes in the dox- versus vehicle-treated samples were identified using the “gene expression” workflow in the Partek® software. T47D cells hoaboring a doxycycline inducible shPIP construct were treated for 24 or 48 hours with 250 ng/mL of doxycycline and their mRNAs analyzed in biological triplicates (a total of 12 samples) using Illumina‘s HumanHT-12 v4 BeadChips. The samples for each time point comprised of three samples each for doxycycline or equal volume of water as vehicle control.