p.m. for 10 min, removal of supernatant and drying at room temperature. Then 20 μl of RNase (100 μg/ml) was added to each tube and incubated at 65°C for 30 min. DNA thus obtained was electrophoresed on 1% agarose gel.
Recombinant plasmid was purified by QIA prep spin miniprep kit (QIAGEN). HPAC, Capan-2 and MIA PaCa-2 cells were routinely cultured in DMEM media supplemented with 10% heat-inactivated FBS, 100 μg/ml penicillin and 100 μg/ml streptomycin, RG7420 price and incubated at 37°C in a humidified atmosphere containing 5% CO2 in air. Gene transfer was performed according to the manufacturer’s protocols. Briefly, ∼3×105 cells/well containing 2 ml appropriate complete growth medium were seeded in a 6-well culture plate, and incubated at 37°C in a 5% CO2 incubator until the cells were 70–80% confluent. A cover slip was plated in each well before seeding. After the cells were ringed with serum-free and antibiotics-free medium, the cells were transfected separately with pcDNA3.1- buy EVP4593 mesothelin cDNA μg/lipofectamine 3 μl (experimental
group), pcDNA3.1 1 μg/lipofectamine 3 μl (vector control) and only lipofectamine 3 μl (mock control), followed by incubation at 37°C in a 5% CO2 incubator for 6 h. Then the medium was replaced by DMEM culture medium containing 20% FBS. After 48 h, two wells in each group were taken out to detect the transient expression of mesothelin by western blot methods, almost whereas others were continuously cultured for stable expression of mesothelin. G418
(600-800 mg/l) was added to select the resistant clones after 48 h. Six days later, when most of the cells died, the concentration of G418 was decreased to 300-400 mg/l and cells were cultured for another 6 days. The medium was changed every 3 or 4 days, and mixed population of G418 resistant cells were collected ∼2 weeks later for the examination of stable expression of mesothelin by western blot methods and RT–PCR assay. Transient p53 siRNA and PUMA-a siRNA transfection Small interfering RNA (siRNA) (20 μl) against p53 was purchased from Cell Signaling Technology. Small interfering RNA (siRNA) (10 μl) against PUMA was purchased from Santa Cruz Biotechnology. For transient transfection, 3.3 nM p53 siRNA,PUMA siRNA and their mock siRNA was transfected into stable transfected cells for 48 h in 6-well plates using Lipofectamine 2000 Reagent (Invitrogen)according to the manufacturer’s instructions. At 48 h after transfection, the effects of gene silencing were measured via western blot. Xenograft tumors and tissue staining All animal experiments were approved by the Institutional Animal Care and Use Committee at the Shandong University. Subconfluent stable pancreatic cancer cells with mesothelin overexpression or shRNA silencing were harvested by trypsinization, and resuspended in DMEM. 2×106 cells were inoculated into the right flank of 5- to 6-week-old male nude mice as described previously .