Background Outcome of low-grade glioma (LGG, WHO grade II) is highly variable reflecting molecular heterogeneity of the disease. We compared two different single modality treatment strategies: standard radiotherapy (RT) versus primary temozolomide (TMZ) chemotherapy with the aim of tailoring treatment and identifying predictive molecular factors. Methods 477 patients (2005 – 2012, median FU 48 months) with a low-grade glioma (astrocytoma, oligoastrocytoma, oligodendroglioma, WHO grade II) with at least one high-risk feature (age > 40 years, progressive disease, tumor > 5 cm or crossing the midline, neurological symptoms (e.g. focal or mental deficits, increased intracranial pressure or intractable seizures)) were, after stratification by chromosome 1p-status, randomized to either conformal RT (50.4 Gy/28 fractions) or dose-dense TMZ (75 mg/m2 daily × 21 days, q28 days, max. 12 cycles). Random treatment allocation was performed online using a minimization technique. A planned analysis was performed after 246 progression events. All analyses are intent to treat. Primary clinical endpoint was progression-free survival (PFS), correlative analyses included molecular markers (1p/19q co-deletion, MGMT methylation status, IDH1+2 mutations). The trial has been registered at the European Trials Registry (EudraCT 2004-002714-11) and at ClinicalTrials.gov (NCT00182819). Findings Four hundred seventy-seven patients were randomized. Severe hematological toxicity occurred in 14% of TMZ-treated patients, infections in 3% of TMZ-treated patients, and 1% of RT-treated patients. Moderate to severe fatigue was recorded in 3% of patients in the RT group and 7% in the TMZ group. At a median follow-up of 48 months (IQR:31–56), median PFS was 39 months (IQR:16–46) in the TMZ arm and 46 months (IQR:19–48) in the RT group (hazard ratio 1.16, 95% CI, 0.9–1.5; p=0.22). Median OS has not been reached. Exploratory analyses identified treatment-dependent variation in outcome of molecular LGG subgroups (n=318). Interpretation There was no significant difference in outcome of the overall patient population treated with either radiotherapy alone or TMZ chemotherapy alone. Further data maturation is needed for overall survival analyses and evaluation of the full predictive impact of the molecular subtypes for individualized treatment choices. Funding Merck & Co, Swiss-Bridge Award 2011, Swiss Cancer League.

To explore interest in and feasibility of the LORD study we conducted a survey among EORTC and BOOG centres. A vast majority of EORTC and BOOG responding centres expressed interest in participation in the LORD study. The proposed study design is endorsed by nearly all centres.

FOXO (Forkhead box O) transcription factors induce cell growth arrest and apoptosis, which can be prevented by FOXO phosphorylation by AKT in response to growth factors such as platelet-derived growth factors (PDGF) and insulin-like growth factor I (IGF-I). In addition to this well characterized post-translational modification, we showed that FOXO1, FOXO3, and FOXO4 were also regulated at the transcriptional level. PDGF, fibroblast growth factors (FGF), and IGF-I repressed the expression of FOXO genes in human fibroblasts. This process was sensitive to phosphatidylinositol 3-kinase inhibition by LY294002. FOXO1-specific shRNA decreased FOXO1 mRNA expression and enhanced fibroblast proliferation, mimicking the effects of growth factors. Conversely, ectopic FOXO3 activation blocked the proliferation of fibroblasts and induced the expression of FOXO1, FOXO4, and p27-KIP1. Using luciferase reporter assays and chromatin immunoprecipitations, we identified a conserved FOXO-binding site in the promoter of the FOXO1 gene, which was required for regulation by PDGF, and mediated the up-regulation of FOXO1 by itself and by FOXO3. Altogether, our results suggest that the expression of FOXO1 and FOXO4 genes is stimulated by FOXO3 and possibly by other FOXO factors in a positive feedback loop, which is disrupted by growth factors.Forkhead transcription factors, which were initially described in Drosophila melanogaster, constitute a family of transcription factors that share a conserved DNA-binding domain, the so-called forkhead box (1, 2). The FOXO (forkhead box O) group comprises four homologous mammalian proteins, namely FOXO1 (also called FKHR), FOXO3 (FKHR-L1), FOXO4 (AFX), and FOXO6. Activation of these factors induces cell cycle arrest, DNA damage repair, differentiation, and apoptosis. They also increase the resistance to oxidative stress, which was shown to be particularly important in hematopoietic stem cells, and regulate glucose metabolism in various organs. In Caenorhabditis elegans, the FOXO orthologue DAF-16 prolongs life span.The activity of FOXO proteins is tightly controlled by multiple post-translational modifications (3, 4). Growth factors, insulin, and other cell stimuli induce FOXO phosphorylation and inactivation by AKT (also called protein kinase B), a serine/ threonine kinase that is activated via the phosphatidylinositol (PI) 3 3-kinase pathway (1, 3). All FOXO proteins are substrates of AKT, which phosphorylates three conserved sites, resulting in the exclusion of FOXOs from the nucleus and in their subsequent ubiquitination and degradation. Phosphorylation by AKT may also regulate FOXO ability to bind to DNA (3). In addition, the mitogen-activated protein kinases ERK and p38, as well as serum-and glucocorticoid-inducible kinase, DIRK1, and IKK␤, also inactivate FOXO1 and/or FOXO3 by direct phosphorylation (1, 5, 6). By contrast, phosphorylation by c-Jun N-terminal kinase (JNK) kinases upon cell stress activates FOXO4 (7).In the absence of growth factors, FOXOs reside in the nucleus and up-regulate g...

In the present study, we aimed to decipher the mechanisms involved in the transcriptional effect of insulin on the SREBP-1c specific promoter of the human srebf-1 gene. Using luciferase reporter gene constructs in HEK-293 cells (human embryonic kidney cells), we demonstrated that the full effect of insulin requires the presence of SREs (sterol response elements) in the proximal region of the promoter. Furthermore, insulin increases the binding of SREBP-1 (sterol-regulatory-element-binding protein-1) to this promoter region in chromatin immunoprecipitation assay. We also found that the nuclear receptors LXRs (liver X receptors) strongly activate SREBP-1c gene expression and identified the LXRE (LXR-response element) involved in this effect. However, our results suggested that these LXREs do not play a major role in the response to insulin. Finally, using expression vectors and adenoviruses allowing ectopic overexpressions of the human mature forms of SREBP-1a or SREBP-1c, we demonstrated the direct role of SREBP-1 in the control of SREBP-1c gene expression in human skeletal-muscle cells. Altogether, these results strongly suggest that the SREBP-1 transcription factors are the main mediators of insulin action on SREBP-1c expression in human tissues.