Standard curve for each gene.Materials and Methods Ethics StatementThe study protocol was approved by the Medical Ethics andHuman Clinical Trial Committee of the Jinan Central Hospital. Written informed consent was obtained from all patients.Cell Culture and Drug TreatmentThe human AFPGC cell line FU97 was obtained from the Japanese Collection of Research Bioresources (Japan) and was maintained in DMEM (Invitrogen) supplemented with 10 fetal bovine serum (FBS; Invitrogen), with 1 antibiotics at 37uC in 5 CO2 humidified air. As2O3 (Sigma) was dissolved in phosphate buffered saline (PBS) at 1 mol/L as a stock solution and stored at 4uC. For in vitro use, the stock solution was diluted to the appropriate concentration in growth medium without FBS. Exponentially growing cells were treated with As2O3 at final concentrations of 1, 5, or 10 mmol/L. Control cultures were treated with distilled PBS at a final concentration of 0.1 in culture medium. All experiments were performed in triplicate.Western Blot AnalysisCell pellets were homogenized in extraction buffer (50 mmol/L Tris-HCl, pH 6.8, 0.1 SDS, 150 mmol/L NaCl, 100 mg/L phenylmethylsulfonyl fluoride, 1 mg/L aprotinin, 1 NP-40 and 0.5 sodium orthovanadate), incubated at 4uC for 30 min, and centrifuged for 20 min at 12 000 g/min. Total protein in the cell lysate was measured with use of the Bio-Rad colorimetric kit (BioRad, Hercules, CA, USA). For western blot analysis, total protein was separated on 10 SDS-PAGE and transferred onto nitrocellulose membranes (0.45 mm, Millipore, Billerica, MA, USA), which were incubated for 24 h at 4uC with the antibodies for AFP (1:500, R D), STAT3 (1:1000),caspase 3 (1:500), Bcl-2 (1:500), BAX(1:500) and GAPDH (1:1000; all Cell signaling technology), then horseradish peroxidase-conjugated anti-mouse/ rabbit IgG antibody (Santa Cruz Biotechnology) after a final wash. Reactions were developed with use of 4-chloro-1-naphthol (Sigma) and H2O2. Signals were detected with use of an enhanced chemiluminescence kit (Amersham Pharmacia, Buckinghamshire, UK). GAPDH level was an 298690-60-5 web internal standard.MTT Cytotoxicity AssayThe effect of As2O3 on inhibiting in vitro growth of FU97 cells was determined by measuring MTT (3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide) dye absorbance of living cells. FU97 cells were seeded in 96-well plates at 1.66 103 cells per well in 100 mL DMEM containing 10 FBS overnight. After exposure to various concentrations of As2O3 for 24, 48 and 72 h, 20 mL (5 g/L) MTT (Sigma, St. Louis, MO) solution was added to each well and plates were incubated for an additional 4 h at 37uC. Formazine was dissolved in 150 mL/well dimethyl sulfoxide (DMSO) and the absorbance was detected at 490 nm. Inhibitory rate ( ) = (12A value in experimental group/A value in control group) 6 100 . The 0 mmol/L group was used as blank control.DNA Fragmentation 24786787 Analysis by ElectrophoresisA total of 106 cells was 24786787 Analysis by ElectrophoresisA total of 106 cells was 18334597 gently scraped from dishes, washed twice in cold PBS, and centrifuged at 15000 rpm for 10 min, then lysed in 200 mL lysis buffer (1 mL of 1 M Tris Cl buffer, pH 7.4, 0.2 mL of 0.5 M ethylenediaminetetraacetic acid [EDTA],Immunoassay of AFP Concentration in SupernatantThe supernatant of FU97 cells were collected after treatment with As2O3 or negative control for 24, 48 and 72 h.AFPNovel Therapy for AFP-Producing Gastric CancersFigure 1. Arsenic trioxide (As2O3)-induced growth inhibition and apoptosis of gastric cancer FU97 cells. (A) Cellular grow.