Immunohistochemistry was performed using standard procedures. In short, liver tissues were removed and fixed in 10% neutral buffered formalin and embedded in paraffin wax. Five-micrometer sections were prepared for hematoxylin and eosin staining and immunofluorescence

analyses. After deparaffinization, antigen unmasking was performed in a decloaking chamber (Biocare Medical, San Diego, CA) using BORG Decloaker Solution (Biocare Medical, San Diego, CA) for 5 minutes at 125°C. The sections were blocked for 30 minutes in Tris-buffered saline/Tween 20 buffer containing 3% goat serum. Primary antibodies used in this study included click here rabbit anti–phospho-STAT5 (Tyr694), anti-cleaved caspase-3 (Cell

Signaling Technology), MG132 rabbit anti-NOX4 (Novus Biologicals, Littleton, CO), rabbit anti-PUMA (Abcam, Cambridge, MA), anti-BIM (Cell Signaling Technology), anti–phospho-histone H3 (Upstate Biotechnology, Lake Placid, NY), and anti-Ki 67 (Santa Cruz Biotechnology) in addition to mouse anti-β-catenin (BD Transduction Laboratories, San Jose, CA). For double-labeling immunofluorescence analyses, sections exposed to a pair of primary antibodies were incubated in a 1:400 dilution of goat anti-rabbit immunoglobulin G (IgG) conjugated with a red fluorophore (Alexa Fluor 594; Molecular Probes, Eugene,

OR) and goat anti-mouse IgG conjugated with a green fluorophore (Alexa Fluor 488; Molecular Probes, Eugene, OR) for 30 min at room temperature. Images were obtained with a Retiga Exi camera on a Olympus BX51 microscope (Olympus America, Center Valley, PA) using Image-Pro 5.1 software. For GH stimulation, mice were injected with 2 μg/g body weight of GH intraperitoneally. They were sacrificed 45 minutes after injection, and liver tissue was harvested. Noninjected mice were used as controls. Liver tissue was cross-linked in 1.5% formaldehyde for 15 minutes MCE at 37°C and sonicated using the Misonix Sonicator 3000 (Misonix, Farmingdale, NY). Immunoprecipitation was carried out in TE buffer containing protease inhibitors (Sigma, St. Louis, MO). Chromatin was incubated with protein A Dynabeads (Invitrogen, Carlsbad, CA), which were preincubated with STAT5A or IgG antibody (R&D Systems, Minneapolis, MN). Immunoprecipitated DNA was eluted and amplified by real-time polymerase chain reaction (PCR) using a 7900 HT fast real-time PCR system (Applied Biosystems, Foster City, CA) and analyzed using SDS2.3 Software (Applied Biosystems, Foster City, CA).