Investigators have demonstrated normal MSCs and established MSC cell lines can protect leukemia cells from apoptosis [3–5]. However, the role of leukemic MSCs in the pathogenesis and prognosis of leukemia are still not well elucidated. What is known is that a substantial number of MSCs from leukemia patients are likely to differentiate into malignant cells and it is these cells that play multiple roles in directly regulating leukemia cells. However, the possibility that MSCs from patients with leukemia AZD5582 datasheet possess similar ability to modulate leukemia cells has not
been well explored. Leukemic MSCs in all probability will aid in cell survival under adverse conditions (e.g., hypoxia, chemotherapy, serum deprivation). For this reason, we have designed a system that mimics a serum deprivation condition high throughput screening (i.e., fetal
bovine serum (FBS) starvation) in order to observe the status of K562 cells and the influence of leukemic MSCs upon them. The PI3K-Akt signal pathway and its downstream target BCL-2 family members play important selleck inhibitor roles in the induction and regulation of cell apoptosis, survival, proliferation and formation of the cellular framework . Many studies have shown that activation of this signaling pathway in some leukemia cells continues for an extended duration [7–9]. An uncertain relationship still exists between the PI3K-Akt pathway and MSCs. Hence, the aim of the present study was to provide a preliminary outline of the variations of key proteins involved in the PI3K-AKt signaling pathway in leukemia cells. Materials and methods Cell line Human chronic myelogenous leukemia cell line Gemcitabine price K562 was maintained in RPMI 1640 media supplemented
with 10% fetal bovine serum (FBS), 100 U/ml penicillin, 100 U/ml streptomycin and 0.2 mmol/L glutamine at 37°C in a humidified incubator with a 5% CO2 atmosphere. Prior to the experiments, the K562 cells were suspended in complete DF-12 medium (Gibco, containing 10% FBS, 100 U/ml penicillin, 100 U/ml streptomycin and 0.2 mmol/L glutamine) or in DF-12 medium without serum. Isolation and characterization of human leukemic mesenchymal stem cells (MSCs) Heparinized bone marrow from each patient (4 patients: 2 with chronic myelogenous leukemia in blast crisis, 1 with acute myelogenous leukemia, and 1 with acute lymphoblastic leukemia) was obtained after informed consent. The marrow was diluted twice with phosphate buffered saline (PBS), then isolated by Ficoll-Hypaque (Institute of Hematology) density-gradient centrifugation. Monocytes were collected by adherence to a plastic flask and incubated for 48 hrs in MSC conditioned medium containing 10% FBS, 0.2 mmol/L glutamine, 10-9 M Dex, 10 ng/ml EGF, 100 U/ml penicillin and 100 U/ml streptomycin. Medium was replaced at least twice a week and nonadherent cells were discarded.