Plasmids and transfection Growth inhibition assays were performed by transiently transfecting CNE-2 cells with 3 μg of pcDNA3.1(+)/RASSF1A construct (a generous gift from Prof. Reinhard Dammann, Department of Biology, Beckman Research learn more Institute, City of Hope Medical Center, Duarte, California, USA.) or pcDNA3.1(+) empty vector using Lipofectamine 2000 (Invitrogen, USA). pCGN-HA-RasG12V (a generous gift from Prof. Geoffrey J. Clark,

Department of Cell and Cancer Biology, National Cancer Institute, Rockville, Maryland, USA.), which contains the cDNAs encoding activated K-Ras gene, was used to perform co-transfection with pcDNA3.1(+)/RASSF1A in CNE-2 cells. Transfection was performed using Lipofectamine 2000 (Invitrogen, USA) according to the manufacturer’s instruction. The expression of exogenous RASSF1A and K-RasG12V was confirmed by RT-PCR analysis and western-bloting. Western-blot analysis Cells were grown and harvested at 70-80% confluency, cellular protein were extracted with lysis buffer which contains PMSF, a protease inhibitors

(BOSTER), Lysates were incubated on ice for 30 min, and insoluble cell debris was removed by centrifugation for NSC23766 solubility dmso 10 min at 12,000 rpm at 4°C. Protein samples were separated by 10-15% SDS-PAGE and were electroblotted to PVDF membranes (Roche) and stained with enhanced chemiluminescence solution. For detection of bound primary antibody, the membranes were then incubated with the mouse monoclonal anti-RASSF1A (eBioscience). β-actin protein level were used as a control for equal protein loading. Cell death assay CNE-2 cell death assays were performed by transfection cells with 4 μg

each of empty vector or pcDNA3.1 (+) RASSF1A in the presence or absence of 40 ng of K-Ras12V. Briefly, 1.5 × 105 CNE-2 cells were seeded in 6-well the plates one day before transfection, 48 h post-transfection, trypan blue was added in situ at a final concentration of 0.04%. Dead cells were quantitated by counting the number of blue cells in three random 40 × field using phase/contrast microscopy. Cell cycle analysis Cell cycle analysis was performed in CNE-2 cells after the treatment of 5-aza-dC for 4 d and transfected with 3 μg of pcDNA3.1 (+)/RASSF1A or empty vector using Lipofectamine 2000. Four days after agent treatment and 48 h after transfection, cells were harvested and fixed in ice-cold 70% ethanol at 4°C overnight. Then cells were washed twice with ice-cold PBS and pelleted by centrifugation and the ethanol was decanted. Cells were resuspended at a concentration of 1 × 106 cells/ml in staining AP26113 nmr solution (65 μg/ml propidium iodide, 50 μg/ml RNase A). After incubation at 37°C in dark for 30 min, cells were subjected to flow cytometry (FACSort) analysis. Cellular DNA content was assessed and cell cycle model was acquired. Apoptosis assays CNE-2 cells were transfected with 4 μg of RASSF1A in the presence or absence of 40 ng of K-RasG12V or empty vector using Lipofectamine 2000.