Selective Akt Inhibitors Synergize with Tyrosine Kinase Inhibitors and Effectively Override Stroma-Associated Cytoprotection of Mutant FLT3-Positive AML Cells

Objectives: Tyrosine kinase inhibitor (TKI)-treated acute myeloid leukemia (AML) patients commonly show rapid and significant peripheral blood blast cell reduction, however a marginal decrease in bone marrow blasts. This suggests a protective environment and highlights the demand for a better understanding of stromal:leukemia cell communication. As a strategy to improve clinical efficacy, we searched for novel agents capable of potentiating the stroma-diminished effects of TKI treatment of mutant FLT3-expressing cells. Methods: We designed a combinatorial high throughput drug screen using well-characterized kinase inhibitor-focused libraries to identify novel kinase inhibitors capable of overriding stromal-mediated resistance to TKIs, such as PKC412 and AC220. Standard liquid culture proliferation assays, cell cycle and apoptosis analysis, and immunoblotting were carried out with cell lines or primary AML to validate putative candidates from the screen and characterize the mechanism(s) underlying observed synergy. Results and Conclusions Our study led to the observation of synergy between selective Akt inhibitors and FLT3 inhibitors against mutant FLT3-positive AML in either the absence or presence of stroma. Our findings are consistent with evidence that Akt activation is characteristic of mutant FLT3-transformed cells, as well as observed residual Akt activity following FLT3 inhibitor treatment. In conclusion, our study highlights the potential importance of Akt as a signaling factor in leukemia survival, and supports the use of the co-culture chemical screen to identify agents able to potentiate TKI anti-leukemia activity in a cytoprotective microenvironment

The Democratic Biopolitics of PrEP

PrEP (Pre-Exposure Prophylaxis) is a relatively new drug-based HIV prevention technique and an important means to lower the HIV risk of gay men who are especially vulnerable to HIV. From the perspective of biopolitics, PrEP inscribes itself in a larger trend of medicalization and the rise of pharmapower. This article reconstructs and evaluates contemporary literature on biopolitical theory as it applies to PrEP, by bringing it in a dialogue with a mapping of the political debate on PrEP. As PrEP changes sexual norms and subjectification, for example condom use and its meaning for gay subjectivity, it is highly contested. The article shows that the debate on PrEP can be best described with the concepts ‘sexual-somatic ethics’ and ‘democratic biopolitics’, which I develop based on the biopolitical approach of Nikolas Rose and Paul Rabinow. In contrast, interpretations of PrEP which are following governmentality studies or Italian Theory amount to either farfetched or trivial positions on PrEP, when seen in light of the political debate. Furthermore, the article is a contribution to the scholarship on gay subjectivity, highlighting how homophobia and homonormativity haunts gay sex even in liberal environments, and how PrEP can serve as an entry point for the destigmatization of gay sexuality and transformation of gay subjectivity. ‘Biopolitical democratization’ entails making explicit how medical technology and health care relates to sexual subjectification and ethics, to strengthen the voice of (potential) PrEP users in health politics, and to renegotiate the profit and power of Big Pharma

The comprehensive microbial resource

The Comprehensive Microbial Resource or CMR (http://cmr.jcvi.org) provides a web-based central resource for the display, search and analysis of the sequence and annotation for complete and publicly available bacterial and archaeal genomes. In addition to displaying the original annotation from GenBank, the CMR makes available secondary automated structural and functional annotation across all genomes to provide consistent data types necessary for effective mining of genomic data. Precomputed homology searches are stored to allow meaningful genome comparisons. The CMR supplies users with over 50 different tools to utilize the sequence and annotation data across one or more of the 571 currently available genomes. At the gene level users can view the gene annotation and underlying evidence. Genome level information includes whole genome graphical displays, biochemical pathway maps and genome summary data. Comparative tools display analysis between genomes with homology and genome alignment tools, and searches across the accessions, annotation, and evidence assigned to all genes/genomes are available. The data and tools on the CMR aid genomic research and analysis, and the CMR is included in over 200 scientific publications. The code underlying the CMR website and the CMR database are freely available for download with no license restrictions

Pathema: a clade-specific bioinformatics resource center for pathogen research

Pathema (http://pathema.jcvi.org) is one of the eight Bioinformatics Resource Centers (BRCs) funded by the National Institute of Allergy and Infectious Disease (NIAID) designed to serve as a core resource for the bio-defense and infectious disease research community. Pathema strives to support basic research and accelerate scientific progress for understanding, detecting, diagnosing and treating an established set of six target NIAID Category A–C pathogens: Category A priority pathogens; Bacillus anthracis and Clostridium botulinum, and Category B priority pathogens; Burkholderia mallei, Burkholderia pseudomallei, Clostridium perfringens and Entamoeba histolytica. Each target pathogen is represented in one of four distinct clade-specific Pathema web resources and underlying databases developed to target the specific data and analysis needs of each scientific community. All publicly available complete genome projects of phylogenetically related organisms are also represented, providing a comprehensive collection of organisms for comparative analyses. Pathema facilitates the scientific exploration of genomic and related data through its integration with web-based analysis tools, customized to obtain, display, and compute results relevant to ongoing pathogen research. Pathema serves the bio-defense and infectious disease research community by disseminating data resulting from pathogen genome sequencing projects and providing access to the results of inter-genomic comparisons for these organisms

The Public Repository of Xenografts enables discovery and randomized phase II-like trials in mice

More than 90% of drugs with preclinical activity fail in human trials, largely due to insufficient efficacy. We hypothesized that adequately powered trials of patient-derived xenografts (PDX) in mice could efficiently define therapeutic activity across heterogeneous tumors. To address this hypothesis, we established a large, publicly available repository of well-characterized leukemia and lymphoma PDXs that undergo orthotopic engraftment, called the Public Repository of Xenografts (PRoXe). PRoXe includes all de-identified information relevant to the primary specimens and the PDXs derived from them. Using this repository, we demonstrate that large studies of acute leukemia PDXs that mimic human randomized clinical trials can characterize drug efficacy and generate transcriptional, functional, and proteomic biomarkers in both treatment-naive and relapsed/refractory disease

The effect of intrauterine inflammation on the perinatal cardiovascular system: consequences for renal, cardiopulmonary and neural systems

Preterm birth poses one of the greatest challenges for perinatal medicine. Preterm birth is responsible for up to 70% of perinatal mortality in developed countries, excluding deaths associated with congenital defects. Infants that survive preterm birth are at the greatest risk of suffering from cardio-respiratory problems, mental retardation, cerebral palsy, vision and hearing impairment, when compared to infants born at term. One of the main causes of preterm birth is chorioamnionitis (intrauterine inflammation), which is defined as inflammation, caused by bacterial infection of the chorion, amnion and placenta, which often leads to an inflammatory response within the fetal circulation. Intrauterine inflammation is not only a cause of preterm birth per se, but is also a major cause of neonatal morbidity and mortality. Importantly, the effect of intrauterine inflammation on the perinatal cardiovascular system remains poorly understood. There is a substantial amount of evidence indicating that being born preterm impairs renal development, however the effect of preterm birth caused by intrauterine inflammation, on renal development is poorly understood. The aim of the first experimental study (chapter 2) in this thesis was to determine the effect of intrauterine inflammation during late gestation, on renal development in preterm fetal sheep. To address this aim, a study of the effect of intrauterine inflammation on renal development was undertaken in a well-established sheep model of intrauterine inflammation. This study demonstrated that experimental chorioamnionitis caused a 23 and 18% reduction in glomerular number in singleton and twin LPS-exposed fetuses respectively, which may contribute to impaired renal function in preterm neonates exposed to chorioamnionitis and increase the risk of hypertension and end-stage renal disease in adulthood. Studies in chapters 3 and 4 were designed to investigate the effect of intrauterine inflammation on fetal and neonatal cardiopulmonary and cerebral hemodynamics. The rational for these studies arises from a large amount of clinical and experimental evidence suggesting that preterm infants exposed to chorioamnionitis are more likely to suffer chronic lung disease (defined by long term respiratory support), and brain injury. The aims of these studies were to investigate the effect of intrauterine inflammation on cardiopulmonary and cerebral hemodynamics in fetal sheep during late gestation and after preterm birth. These studies demonstrated that intrauterine inflammation impaired pulmonary blood flow and increased cerebral blood flow in fetal sheep. These hemodynamic changes persisted in the preterm neonate with an added increase in cerebral oxygen delivery. These data have developed our knowledge the pathophysiology underlying the increased incidence of chronic lung disease and brain injury in preterm infants exposed to intrauterine inflammation. Furthermore, they suggest that inflammation induced changes to pulmonary vascular development and cerebral metabolism may be detected in the fetus

The effect of intrauterine inflammation on the perinatal cardiovascular system: consequences for renal, cardiopulmonary and neural systems

Preterm birth poses one of the greatest challenges for perinatal medicine. Preterm birth is responsible for up to 70% of perinatal mortality in developed countries, excluding deaths associated with congenital defects. Infants that survive preterm birth are at the greatest risk of suffering from cardio-respiratory problems, mental retardation, cerebral palsy, vision and hearing impairment, when compared to infants born at term. One of the main causes of preterm birth is chorioamnionitis (intrauterine inflammation), which is defined as inflammation, caused by bacterial infection of the chorion, amnion and placenta, which often leads to an inflammatory response within the fetal circulation. Intrauterine inflammation is not only a cause of preterm birth per se, but is also a major cause of neonatal morbidity and mortality. Importantly, the effect of intrauterine inflammation on the perinatal cardiovascular system remains poorly understood. There is a substantial amount of evidence indicating that being born preterm impairs renal development, however the effect of preterm birth caused by intrauterine inflammation, on renal development is poorly understood. The aim of the first experimental study (chapter 2) in this thesis was to determine the effect of intrauterine inflammation during late gestation, on renal development in preterm fetal sheep. To address this aim, a study of the effect of intrauterine inflammation on renal development was undertaken in a well-established sheep model of intrauterine inflammation. This study demonstrated that experimental chorioamnionitis caused a 23 and 18% reduction in glomerular number in singleton and twin LPS-exposed fetuses respectively, which may contribute to impaired renal function in preterm neonates exposed to chorioamnionitis and increase the risk of hypertension and end-stage renal disease in adulthood. Studies in chapters 3 and 4 were designed to investigate the effect of intrauterine inflammation on fetal and neonatal cardiopulmonary and cerebral hemodynamics. The rational for these studies arises from a large amount of clinical and experimental evidence suggesting that preterm infants exposed to chorioamnionitis are more likely to suffer chronic lung disease (defined by long term respiratory support), and brain injury. The aims of these studies were to investigate the effect of intrauterine inflammation on cardiopulmonary and cerebral hemodynamics in fetal sheep during late gestation and after preterm birth. These studies demonstrated that intrauterine inflammation impaired pulmonary blood flow and increased cerebral blood flow in fetal sheep. These hemodynamic changes persisted in the preterm neonate with an added increase in cerebral oxygen delivery. These data have developed our knowledge the pathophysiology underlying the increased incidence of chronic lung disease and brain injury in preterm infants exposed to intrauterine inflammation. Furthermore, they suggest that inflammation induced changes to pulmonary vascular development and cerebral metabolism may be detected in the fetus