Clinical Laboratory Testing Practices in Diffuse Gliomas Prior to Publication of 2021 World Health Organization Classification of Central Nervous System Tumors

CONTEXT.—: Integration of molecular data into glioma classification supports diagnostic, prognostic, and therapeutic decision-making; however, testing practices for these informative biomarkers in clinical laboratories remain unclear. OBJECTIVE.—: To examine the prevalence of molecular testing for clinically relevant biomarkers in adult and pediatric gliomas through review of a College of American Pathologists proficiency testing survey prior to the release of the 2021 World Health Organization Classification of Central Nervous System Tumors. DESIGN.—: College of American Pathologists proficiency testing 2020 survey results from 96 laboratories performing molecular testing for diffuse gliomas were used to determine the use of testing for molecular biomarkers in gliomas. RESULTS.—: The data provide perspective into the testing practices for diffuse gliomas from a broad group of clinical laboratories in 2020. More than 98% of participating laboratories perform testing for glioma biomarkers recognized as diagnostic for specific subtypes, including IDH. More than 60% of laboratories also use molecular markers to differentiate between astrocytic and oligodendroglial lineage tumors, with some laboratories providing more comprehensive analyses, including prognostic biomarkers, such as CDKN2A/B homozygous deletions. Almost all laboratories test for MGMT promoter methylation to identify patients with an increased likelihood of responding to temozolomide. CONCLUSIONS.—: These findings highlight the state of molecular testing in 2020 for the diagnosis and classification of diffuse gliomas at large academic medical centers. The findings show that comprehensive molecular testing is not universal across clinical laboratories and highlight the gaps between laboratory practices in 2020 and the recommendations in the 2021 World Health Organization Classification of Central Nervous System Tumors

What Have We Learned From Decades of CRT, And Where Do We Go From Here?

The Chemical Reactivity Test, or CRT, has been the workhorse for determining short-to-medium term compatibility and thermal stability for energetic materials since the mid 1960s. The concept behind the CRT is quite simple. 0.25 g of material is heated in a 17 cm{sup 3} vessel for 22 hours at 80, 100, or 120 C, and the yield of gaseous products are analyzed by gas chromatography to determine its thermal stability. The instrumentation is shown in Figure 1, and the vessel configuration is shown in Figure 2. For compatibility purposes, two materials, normally 0.25 g of each, are analyzed as a mixture. Recently, data from the past 4 decades have been compiled in an Excel spreadsheet and inspected for reliability and internal consistency. The resulting processed data will be added this year to the LLNL HE Reference Guide. Also recently, we have begun to assess the suitability of the CRT to answer new compatibility issues, especially in view of more modern instrumentation now available commercially. One issue that needs to be addressed is the definition of thermal stability and compatibility from the CRT. Prokosch and Garcia (and the associated MIL-STD-1751A) state that the criterion for thermal stability is a gas yield of less than 4 cm{sup 3}/g for a single material for 22 hours at 120 C. The gases from energetic materials of interest ordinarily have an average molecular weight of about 36 g/mol, so this represents decomposition of 0.5-1.0% of the sample. This is a reasonable value, and a relatively unstable energetic material such as PETN has no problem passing. PBX 9404, which yields 1.5 to 2.0 cm{sup 3}/g historically, is used as a periodic check standard. This is interesting in itself, since the nitrocellulose in the 9404 is unstable and probably has partially decomposed over the decades. However, it is not clear whether this aging of the standard would lead to more or less gas, since the initial gaseous degradation products are captured by the DPA stabilizer. Clearly this is an issue that needs reconsideration. The criterion for compatibility is less clearly correct. Although some LLNL reports say that generation of gas in excess of the materials by themselves is an indication of incompatibility, LLNL reports invariably say that materials are compatible if they generate less than 1 cm{sup 3}/g of gas. There are two problems with this criterion. First, it is not stated whether the gas yield is per gram of energetic material or mixture. Second, a material that generates >2 cm{sup 3}/g by itself could never pass the compatibility tests as stated, because even a mixture of equal masses of that material with a completely inert material would generate >1 cm{sup 3}/g of gas per mixture. Furthermore, Prokosch states that a yield equal to or less than from the materials individually means that no reaction has occurred. Clearly, less gas can not be generated unless some type of interaction has occurred. An obvious example would be mixing CaO with a CO{sub 2}-generating energetic material. In the absence of any direct action of the CaO on the energetic material, the CO{sub 2} product would be captured by the CaO, thereby decreasing the gas yield and liberating considerable heat. In a large, closed volume, this could tip the balance to thermal runaway

BIM mediates synergistic killing of B-cell acute lymphoblastic leukemia cells by BCL-2 and MEK inhibitors

B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive hematological disease that kills ~50% of adult patients. With the exception of some BCR-ABL1(+) patients who benefit from tyrosine kinase inhibitors, there are no effective targeted therapies for adult B-ALL patients and chemotherapy remains first-line therapy despite adverse side effects and poor efficacy. We show that, although the MEK/ERK pathway is activated in B-ALL cells driven by different oncogenes, MEK inhibition does not suppress B-ALL cell growth. However, MEK inhibition synergized with BCL-2/BCL-XL family inhibitors to suppress proliferation and induce apoptosis in B-ALL cells. We show that this synergism is mediated by the pro-apoptotic factor BIM, which is dephosphorylated as a result of MEK inhibition, allowing it to bind to and neutralize MCL-1, thereby enhancing BCL-2/BCL-XL inhibitor-induced cell death. This cooperative effect is observed in B-ALL cells driven by a range of genetic abnormalities and therefore has significant therapeutic potential

Propagation or failure of detonation across an air gap in an LX-17 column: continuous time-dependent detonation or shock speed using the Embedded Fiber Optic (EFO) technique

The detailed history of the shock/detonation wave propagation after crossing a room-temperature-room-pressure (RTP) air gap between a 25.4 mm diameter LX-17 donor column and a 25.4 mm diameter by 25.4 mm long LX-17 acceptor pellet is investigated for three different gap widths (3.07, 2.08, and 0.00 mm) using the Embedded Fiber Optic (EFO) technique. The 2.08 mm gap propagated and the 3.07 mm gap failed and this can be seen clearly and unambiguously in the EFO data even though the 25.4 mm-long acceptor pellet would be considered quite short for a determination by more traditional means such as pins

Laser-Shock Compression and Hugoniot Measurements of Liquid Hydrogen to 55 GPa

The principal Hugoniot for liquid hydrogen was obtained up to 55 GPa under laser-driven shock loading. Pressure and density of compressed hydrogen were determined by impedance-matching to a quartz standard. The shock temperature was independently measured from the brightness of the shock front. Hugoniot data of hydrogen provide a good benchmark to modern theories of condensed matter. The initial number density of liquid hydrogen is lower than that for liquid deuterium, and this results in shock compressed hydrogen having a higher compression and higher temperature than deuterium at the same shock pressure.Comment: 8 pages, 7 figures, 2 tables, accepted for publication in Physical Review

Long-term in vitro maintenance of clonal abundance and leukaemia-initiating potential in acute lymphoblastic leukaemia

Lack of suitable in vitro culture conditions for primary acute lymphoblastic leukaemia (ALL) cells severely impairs their experimental accessibility and the testing of new drugs on cell material reflecting clonal heterogeneity in patients. We show that Nestin-positive human mesenchymal stem cells (MSCs) support expansion of a range of biologically and clinically distinct patient-derived ALL samples. Adherent ALL cells showed an increased accumulation in the S phase of the cell cycle and diminished apoptosis when compared with cells in the suspension fraction. Moreover, surface expression of adhesion molecules CD34, CDH2 and CD10 increased several fold. Approximately 20% of the ALL cells were in G0 phase of the cell cycle, suggesting that MSCs may support quiescent ALL cells. Cellular barcoding demonstrated long-term preservation of clonal abundance. Expansion of ALL cells for >3 months compromised neither feeder dependence nor cancer initiating ability as judged by their engraftment potential in immunocompromised mice. Finally, we demonstrate the suitability of this co-culture approach for the investigation of drug combinations with luciferase-expressing primograft ALL cells. Taken together, we have developed a preclinical platform with patient-derived material that will facilitate the development of clinically effective combination therapies for ALL

Predicting effective pro-apoptotic antileukaemic drug combinations using cooperative dynamic BH3 profiling

The BH3-only apoptosis agonists BAD and NOXA target BCL-2 and MCL-1 respectively and co-operate to induce apoptosis. On this basis, therapeutic drugs targeting BCL-2 and MCL-1 might have enhanced activity if used in combination. We identified anti-leukaemic drugs sensitising to BCL-2 antagonism and drugs sensitising to MCL-1 antagonism using the technique of dynamic BH3 profiling, whereby cells were primed with drugs to discover whether this would elicit mitochondrial outer membrane permeabilisation in response to BCL-2-targeting BAD-BH3 peptide or MCL-1-targeting MS1-BH3 peptide. We found that a broad range of anti-leukaemic agents–notably MCL-1 inhibitors, DNA damaging agents and FLT3 inhibitors–sensitise leukaemia cells to BAD-BH3. We further analysed the BCL-2 inhibitors ABT-199 and JQ1, the MCL-1 inhibitors pladienolide B and torin1, the FLT3 inhibitor AC220 and the DNA double-strand break inducer etoposide to correlate priming responses with co-operative induction of apoptosis. ABT-199 in combination with pladienolide B, torin1, etoposide or AC220 strongly induced apoptosis within 4 hours, but the MCL-1 inhibitors did not co-operate with etoposide or AC220. In keeping with the long half-life of BCL-2, the BET domain inhibitor JQ1 was found to downregulate BCL-2 and to prime cells to respond to MS1-BH3 at 48, but not at 4 hours: prolonged priming with JQ1 was then shown to induce rapid cytochrome C release when pladienolide B, torin1, etoposide or AC220 were added. In conclusion, dynamic BH3 profiling is a useful mechanism-based tool for understanding and predicting co-operative lethality between drugs sensitising to BCL-2 antagonism and drugs sensitising to MCL-1 antagonism. A plethora of agents sensitised cells to BAD-BH3-mediated mitochondrial outer membrane permeabilisation in the dynamic BH3 profiling assay and this was associated with effective co-operation with the BCL-2 inhibitory compounds ABT-199 or JQ1

Small molecules, big targets: drug discovery faces the protein-protein interaction challenge.

Protein-protein interactions (PPIs) are of pivotal importance in the regulation of biological systems and are consequently implicated in the development of disease states. Recent work has begun to show that, with the right tools, certain classes of PPI can yield to the efforts of medicinal chemists to develop inhibitors, and the first PPI inhibitors have reached clinical development. In this Review, we describe the research leading to these breakthroughs and highlight the existence of groups of structurally related PPIs within the PPI target class. For each of these groups, we use examples of successful discovery efforts to illustrate the research strategies that have proved most useful.JS, DES and ARB thank the Wellcome Trust for funding.This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nrd.2016.2