4, for 12 min. The sections were then blocked buy QNZ for 1 h with normal goat serum. After incubating with the primary rabbit anti-human antibody for 1 h at room temperature, the cryostat sections were washed in PBS and incubated with a secondary anti-rabbit biotinylated antibody for 30 min, and subsequently with the streptavidin-HRP complex for 10 min, rinsed in PBS. And then the sections were stained with ACE solution

for 10 min. Finally the sections were stained with haematoxylin. The results were analyzed with Point rating method. We used the percentage of GADD45α-positiv stained cells and the intensity of GADD45α expression by the tumor cells to grade all the samples. And the multiplication of these two grading scores calculates the immunoreactive score for GADD45α expression (GADD45α-IRS) in stained tissue (%GADD45α -positive tumor cells × staining intensity = GADD45α-IRS). Western blot analysis For tumor and adjacent normal tissues were frozen in liquid nitrogen and powdered with mortar and pestle and lysed by cell lysis buffer. Samples were transferred to microcentrifuge tubes, homogenized,

and protein pelleted by microcentrifugation at 14 000 rpm and 4°C for 15 min. The Compound C order samples were diluted with 2 × sodium dodecyl sulfate (SDS) sample buffer and boiled. SDS samples were resolved by polyacrylamide gel electrophoresis and transferred onto polyvinylidene difluoride membrane. The membranes were incubated with the primary antibodies and then with horseradish peroxidase-conjugated

secondary antibodies. The immunoblotted proteins were photographed using Lumiglo Reagent (#7003, CellSignaling Inc.). Transfections Control small interfering RNA (siRNA) and siRNA targeting GADD45α were designed and synthesized at Qiagen USA. The sequences of the siRNA for GADD45α were as follows: target Panobinostat sequence 5′-AACATCCTGCGCGTCAGCAAC-3′, sense strand5′-CAUCCUGCGCGUCAGCAACTT-3′, Antisense strand: 5′-GUUGCUGACGCGCAGGAUGTT-3′. Lipofectamine 2000 was used to transfect siRNA and negative control into the two cell lines ECA109 and kyse510. Total RNA was extracted from esophageal squamous cell cancer tissue, and GADD45α cDNA was amplified by RT-PCR. The PCR Coproporphyrinogen III oxidase product was doubly digested by Xbal and Sall, and then recombined into eukaryotic expression vector. Then, pIRES-GFP-GADD45α was obtained by G418 selection, and then pIRES-GFP- GADD45α and pIRES-GFP were transfected into human esophageal squamous epithelial cells with lipidosome-packaged method. Meanwhile, the transfected cells were selected by G418, and then stable transfected cell lines were obtained. Drug sensitivity assay Cells (1 × 105/ml) were cultured in 96 cell plates after 1 day of transfectioin. After 1 day of culturing, the cells were treated with various concentrations of cisplatin (DDP). After 24 h, 48 h and 72 h of treatment, 20 ul MTT (Roche, Mannheim Germany) solution (2 mg/ml) was added to each well, and the plate was then incubated at 37°C for 4 h.