A siRNA with the sequence 5′-GGACCCAGUUGUACCUAAUdTdT-3′ was determined to be the most effective siRNA for inhibiting BMPR-IB expression. The BMPR-IB siRNA was further incorporated into the pSilencer plasmid (Ambion, USA). SF763 cells were transfected with the BMPR-IB siRNA expression vector (si-BMPR-IB) or the control vector (si-control). The cell lines, which stably expressed BMPR-IB siRNA, were isolated by neomycin (G418) selection. Quantitative real-time RT-PCR Total RNA, which derived from glioma cells, was prepared using TRIzol (Gibco), and further purified using the RNeasy Mini Kit (Qiagen).
Real-time PCR was performed according to the manufacturer’s instructions using an ABI Prism 7900 sequence detection system CB-839 in vitro (Applied Biosystems, USA). Primers and probes for p21, p27, p53, CDK2, CDK4, Skp2, BMPR-IB (human) and GAPDH were obtained from Applied Biosystems, USA. Additional file 1: Table S 1 shows the forward and reverse primer sequences of theses genes. All samples were tested in triplicate. The relative number of target transcripts was normalized to the number of human GAPDH transcripts in the same sample. The relative quantitation
Stattic order of target gene expression was performed using the standard curve or comparative cycle threshold (Ct) method. Western blot analysis Whole-cell lysates were isolated from glioma cells and the transplanted glioma tissues (5). Standard western blotting was performed with monoclonal antibodies against human BMPR-IB, p21, p27KIP1, Skp2, Cdk2, Cdk4, p53, GFAP, Nestin and β-actin proteins(Santa Cruz Biotechnology,USA) and the corresponding secondary antibodies
(anti-rabbit IgG, anti-mouse IgG, and anti-goat IgG; Abcam, USA). Human β-actin was used as a loading control. These proteins were detected using the Amersham enhanced chemiluminescence system according to the manufacturer’s instructions. Immunofluorescent staining At 48 h following AAV-BMPR-IB infection, the U251 and U87 cells were fixed in 4% paraformaldehyde-PBS. After incubation with 0.1% Triton-PBS for Erastin 30 min and blocking with 1% bovine serum albumin-PBS for 2 h in room temperature, the cells were then incubated with the primary antibodies overnight in 4°C at the concentration recommended by the supplier (a rabbit anti-phospho-Smad1/5/8 antibody (Cell signal), a goat anti-BMPR-IB antibody (Santa Cruz Biotechnology) and a mouse anti-GFAP antibody (Sigma)). After washing with 0.1% Triton-PBS three times, cells were incubated with RBITC-conjugated rabbit anti-goat IgG and FITC-conjugated goat anti-rabbit IgG (Santa Cruz Biotechnology) for 2 h in room temperature. The cell check details nuclei were stained with DAPI. The stained cells were visualized and mounted with a confocal laser scanning microscope (Olympus).