, Vantaa, Finland). Values were obtained by BIX 1294 price comparing these cells with their respective controls. Cell cycle analysis For each analysis, 106 cells were harvested 48 h after treatment and fixed overnight in 70% ethanol at 4°C. Cells were then washed and stained with 5 μg/ml PI in the presence of DNAse free
RNAse (Sigma). After 30 min at room temperature, the cells were analyzed via flow cytometry (Beckman Coulter, Inc., Miami, FL, USA). Assay for apoptosis The samples were washed with phosphate-buffered saline (PBS) twice and re-suspended in 500 μl of binding buffer containing 5 μl of Annexin V-FITC stock solution and 5 μl of PI for determination of phosphatidylserine exposure on the outer plasma membrane. After incubation for 10 min at room temperature in a light-protected area, the samples were quantified by flow cytometry (FASCAria,
FHPI purchase BD Bioscience, San Jose, CA). Western blot analysis Cells (106) were washed twice in cold PBS, and then lysed by Laemmli sample buffer (Bio-Rad, Hercules, CA, USA). Samples were boiled for 5 min at 100°C. Proteins were separated on 10% or 15% SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and transferred onto nitrocellulose membranes selleck kinase inhibitor (0.45 μm, Mllipore, São Paulo, SP, Brazil). Nonspecific-binding sites were blocked with 5% non-fat dry milk dissolved in TBS (10 mM Tris-HCl, pH 7.6, 137 mM NaCl) with 0.1% Tween 20 (TTBS) for 1 h at room temperature followed by incubation with primary antibody at 4°C overnight. The membranes were then washed 3 times in TTBS and incubated for 1 h at room temperature with secondary horseradish peroxidase (HRP)-conjugated donkey anti-rabbit antibody or HRP-conjugated sheep anti-mouse antibody diluted 1:5000 in TTBS with 5% non-fat milk. Proteins were visualized by ECL plus (Amersham Biosciences, Inc., Piscataway, NJ). All experiments were carried out independently at least 3 times. The level of the GAPDH protein was used as a control of the amount of protein loaded into each lane. Statistical analysis All assays were performed
in triplicate, and data are expressed as mean values ±SD. The Student’s Farnesyltransferase t-test was used to compare two groups. Results were considered significant with p -value < 0.05. Results Rapamycin and Dex inhibit growth of T-ALL cells synergistically It has been reported that rapamycin can sensitize multiple myeloma cells to apoptosis induced by Dex [9, 11]. In order to evaluate the potential of rapamycin for the treatment of GC-resistant ALL, we selected a panel of four T-ALL cell lines, GC-sensitive CEM-C7-14, and the GC-resistant CEM-C1-15, Molt-4, and Jurkat. Four cell lines were incubated for 48 h with rapamycin and/or Dex. Rapamycin inhibited the growth of all the four T-ALL cell lines. The percentage of viable cells were from the lowest of 46% in Molt-4 to the highest of 66% in CEM-C7-14 as compared to their control group, p < 0.05. The response of the T-ALL cell lines to Dex varied.