Determination of caspase-3 activation fails to predict chemosensitivity in primary acute myeloid leukemia blasts

BACKGROUND: Ex-vivo chemosensitivity tests that measure cell death induction may predict treatment outcome and, therefore, represent a powerful instrument for clinical decision making in cancer therapy. Such tests are, however, work intensive and, in the case of the DiSC-assay, require at least four days. Induction of apoptosis is the mode of action of anticancer drugs and should, therefore, result in the induction of caspase activation in cells targeted by anticancer therapy. METHODS: To determine, whether caspase activation can predict the chemosensitivity, we investigated enzyme activation of caspase-3, a key executioner caspase and correlated these data with chemosensitivity profiles of acute myeloid leukemia (AML) blasts. RESULTS: There was, however, no correlation between the ex-vivo chemosensitivity assessed by measuring the overall rates of cell death by use of the DiSC-assay and caspase-3 activation. CONCLUSION: Thus, despite a significant reduction of duration of the assay from four to one day, induction of apoptosis evaluated by capase-3 activity does not seem to be a valid surrogate marker for chemosensitivity

Correlating Global Gene Regulation to Angiogenesis in the Developing Chick Extra-Embryonic Vascular System

International audienceBACKGROUND: Formation of blood vessels requires the concerted regulation of an unknown number of genes in a spatial-, time- and dosage-dependent manner. Determining genes, which drive vascular maturation is crucial for the identification of new therapeutic targets against pathological angiogenesis. METHOLOGY/PRINCIPAL FINDINGS: We accessed global gene regulation throughout maturation of the chick chorio-allantoic membrane (CAM), a highly vascularized tissue, using pan genomic microarrays. Seven percent of analyzed genes showed a significant change in expression (>2-fold, FDR<5%) with a peak occurring from E7 to E10, when key morphogenetic and angiogenic genes such as BMP4, SMO, HOXA3, EPAS1 and FGFR2 were upregulated, reflecting the state of an activated endothelium. At later stages, a general decrease in gene expression occurs, including genes encoding mitotic factors or angiogenic mediators such as CYR61, EPAS1, MDK and MYC. We identified putative human orthologs for 77% of significantly regulated genes and determined endothelial cell enrichment for 20% of the orthologs in silico. Vascular expression of several genes including ENC1, FSTL1, JAM2, LDB2, LIMS1, PARVB, PDE3A, PRCP, PTRF and ST6GAL1 was demonstrated by in situ hybridization. Up to 9% of the CAM genes were also overexpressed in human organs with related functions, such as placenta and lung or the thyroid. 21-66% of CAM genes enriched in endothelial cells were deregulated in several human cancer types (P<.0001). Interfering with PARVB (encoding parvin, beta) function profoundly changed human endothelial cell shape, motility and tubulogenesis, suggesting an important role of this gene in the angiogenic process. CONCLUSIONS/SIGNIFICANCE: Our study underlines the complexity of gene regulation in a highly vascularized organ during development. We identified a restricted number of novel genes enriched in the endothelium of different species and tissues, which may play crucial roles in normal and pathological angiogenesis

Magna Carta, the Rule of Law and the Limits on Government

This paper surveys the legal tradition that links Magna Carta with the modern concepts of the rule of law and the limits on government. It documents that the original understanding of the rule of law included substantive commitments to individual freedom and limited government. Then, it attempts at explaining how and why such commitments were lost to a formalist interpretation of the rule of law from 1848 to 1939. The paper concludes by arguing how a revival of the substantive commitments of the rule of law is central in a project of reshaping modern states