Here, oligonucleotide array analysis was used to determine gene transcription profiles resulting from these two Ca 2ϩ entry pathways in human cerebrovascular smooth muscle cell cultures. Results were confirmed and expanded using quantitative RT-PCR, Western blot, and immunofluorescence. A distinct, yet overlapping, set of CREregulated genes was induced by VDCC activation using K ϩ membrane depolarization vs. SOCC activation by thapsigargin (TG). Membrane depolarization selectively induced a sustained increase in early growth response-1 (Egr-1) mRNA and protein, which were inhibited by the VDCC blocker nimodipine and the SOCC inhibitor 2-aminoethoxydiphenylborate (2-APB). TG selectively induced a sustained increase in MAPK phosphatase-1 (MKP-1) mRNA and protein, and these effects were decreased by 2-APB, but not by nimodipine. The physiological agonist ANG II also stimulated expression of Egr-1 and MKP-1. Coadministration of 2-APB prevented expression of Egr-1 and MKP-1, whereas nimodipine blocked only Egr-1 expression. TG and ANG II induced phosphorylation of ERK, which was sensitive to 2-APB and was selectively required for CRE-binding protein phosphorylation. Our findings thus indicate that Ca 2ϩ entry through VDCCs and store-operated Ca 2ϩ entry can differentially regulate CRE-containing genes in vascular smooth muscle and also imply that agonist-induced signals involved in modulation of gene transcription can be controlled by multiple sources of Ca 2ϩ .

Medulloblastoma (MB) is the most common malignant brain tumor in children, accounting for nearly 20 percent of all childhood brain tumors. New treatment strategies are needed to improve patient survival outcomes and to reduce adverse effects of current therapy. The phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) intracellular signaling pathway plays a key role in cellular metabolism, proliferation, survival and angiogenesis, and is often constitutively activated in human cancers, providing unique opportunities for anticancer therapeutic intervention. The aim of this study was to evaluate the pre-clinical activity of BKM120, a selective pan-class I PI3K inhibitor, on MB cell lines and primary samples. IC50 values of BKM120 in the twelve MB cell lines tested ranged from 0.279 to 4.38 μM as determined by cell viability assay. IncuCyte ZOOM Live-Cell Imaging system was used for kinetic monitoring of cytotoxicity of BKM120 and apoptosis in MB cells. BKM120 exhibited cytotoxicity in MB cells in a dose and time-dependent manner by inhibiting activation of downstream signaling molecules AKT and mTOR, and activating caspase-mediated apoptotic pathways. Furthermore, BKM120 decreased cellular glycolytic metabolic activity in MB cell lines in a dose-dependent manner demonstrated by ATP level per cell. In MB xenograft mouse study, DAOY cells were implanted in the flank of nude mice and treated with vehicle, BKM120 at 30 mg/kg and 60 mg/kg via oral gavage daily. BKM120 significantly suppressed tumor growth and prolonged mouse survival. These findings help to establish a basis for clinical trials of BKM120, which could be a novel therapy for the treatment of medulloblastoma patients.

Wall EH, Bond JP, McFadden TB. Acute milk yield response to frequent milking during early lactation is mediated by genes transiently regulated by milk removal.

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