Novel Methionine Aminopeptidase 2 Inhibitor M8891 Synergizes with VEGF Receptor Inhibitors to Inhibit Tumor Growth of Renal Cell Carcinoma Models

N-terminal processing by methionine aminopeptidases (MetAP) is a crucial step in the maturation of proteins during protein biosynthesis. Small-molecule inhibitors of MetAP2 have antiangiogenic and antitumoral activity. Herein, we characterize the structurally novel MetAP2 inhibitor M8891. M8891 is a potent, selective, reversible small-molecule inhibitor blocking the growth of human endothelial cells and differentially inhibiting cancer cell growth. A CRISPR genome-wide screen identified the tumor suppressor p53 and MetAP1/MetAP2 as determinants of resistance and sensitivity to pharmacologic MetAP2 inhibition. A newly identified substrate of MetAP2, translation elongation factor 1-alpha-1 (EF1a-1), served as a pharmacodynamic biomarker to follow target inhibition in cell and mouse studies. Robust angiogenesis and tumor growth inhibition was observed with M8891 monotherapy. In combination with VEGF receptor inhibitors, tumor stasis and regression occurred in patient-derived xenograft renal cell carcinoma models, particularly those that were p53 wild-type, had Von Hippel-Landau gene (VHL) loss-of-function mutations, and a mid/high MetAP1/2 expression score.

Extract2Chip-Bypassing Protein Purification in Drug Discovery Using Surface Plasmon Resonance

Modern drug discovery relies on combinatorial screening campaigns to find drug molecules targeting specific disease-associated proteins. The success of such campaigns often relies on functional and structural information of the selected therapeutic target, only achievable once its purification is mastered. With the aim of bypassing the protein purification process to gain insights on the druggability, ligand binding, and/or characterization of protein-protein interactions, herein, we describe the Extract2Chip method. This approach builds on the immobilization of site-specific biotinylated proteins of interest, directly from cellular extracts, on avidin-coated sensor chips to allow for the characterization of molecular interactions via surface plasmon resonance (SPR). The developed method was initially validated using Cyclophilin D (CypD) and subsequently applied to other drug discovery projects in which the targets of interest were difficult to express, purify, and crystallize. Extract2Chip was successfully applied to the characterization of Yes-associated protein (YAP): Transcriptional enhancer factor TEF (TEAD1) protein-protein interaction inhibitors, in the validation of a ternary complex assembly composed of Dyskerin pseudouridine synthase 1 (DKC1) and RuvBL1/RuvBL2, and in the establishment of a fast-screening platform to select the most suitable NUAK family SNF1-like kinase 2 (NUAK2) surrogate for binding and structural studies. The described method paves the way for a potential revival of the many drug discovery campaigns that have failed to deliver due to the lack of suitable and sufficient protein supply.

MCT4 blockade increases the efficacy of immune checkpoint blockade

BACKGROUND & AIMS

Intratumoral lactate accumulation and acidosis impair T-cell function and antitumor immunity. Interestingly, expression of the lactate transporter monocarboxylate transporter (MCT) 4, but not MCT1, turned out to be prognostic for the survival of patients with rectal cancer, indicating that single MCT4 blockade might be a promising strategy to overcome glycolysis-related therapy resistance.

METHODS

To determine whether blockade of MCT4 alone is sufficient to improve the efficacy of immune checkpoint blockade (ICB) therapy, we examined the effects of the selective MCT1 inhibitor AZD3965 and a novel MCT4 inhibitor in a colorectal carcinoma (CRC) tumor spheroid model co-cultured with blood leukocytes in vitro and the MC38 murine CRC model in vivo in combination with an antibody against programmed cell death ligand-1(PD-L1).

RESULTS

Inhibition of MCT4 was sufficient to reduce lactate efflux in three-dimensional (3D) CRC spheroids but not in two-dimensional cell-cultures. Co-administration of the MCT4 inhibitor and ICB augmented immune cell infiltration, T-cell function and decreased CRC spheroid viability in a 3D co-culture model of human CRC spheroids with blood leukocytes. Accordingly, combination of MCT4 and ICB increased intratumoral pH, improved leukocyte infiltration and T-cell activation, delayed tumor growth, and prolonged survival in vivo. MCT1 inhibition exerted no further beneficial impact.

CONCLUSIONS

These findings demonstrate that single MCT4 inhibition represents a novel therapeutic approach to reverse lactic-acid driven immunosuppression and might be suitable to improve ICB efficacy.

Comparative analysis of YAP/TEAD inhibitors in 2D and 3D cultures of primary human hepatocytes reveals a novel non-canonical mechanism of CYP induction

Induction of cytochrome P450 (CYP) genes constitutes an important cause of drug-drug interactions and preclinical evaluation of induction liability is mandatory for novel drug candidates. YAP/TEAD signaling has emerged as an attractive target for various oncological indications and multiple chemically distinct YAP/TEAD inhibitors are rapidly progressing towards clinical stages. Here, we tested the liability for CYP induction of a diverse set of YAP/TEAD inhibitors with different modes of action and TEAD isoform selectivity profiles in monolayers and 3D spheroids of primary human hepatocytes (PHH). We found that YAP/TEAD inhibition resulted in broad induction of CYPs in 2D monolayers, whereas, if at all, only marginal induction was seen in spheroid culture. Comprehensive RNA-Seq indicated that YAP/TEAD signaling was increased in 2D culture compared to spheroids, which was paralleled by elevated activities of the interacting transcription factors LXR and ESRRA, likely at least in part due to altered mechanosensing. Inhibition of this YAP/TEAD hyperactivation resulted in an overall reduction of hepatocyte dedifferentiation marked by increased hepatic functionality, including CYPs. These results thus demonstrate that the observed induction is due to on-target effects of the compounds rather than direct activation of xenobiotic sensing nuclear receptors. Combined, the presented data link hepatocyte dedifferentiation to YAP/TEAD dysregulation, reveal a novel non-canonical pathway of CYP induction and highlight the advantage of organotypic 3D cultures to predict clinically relevant pharmacokinetic properties, particularly for atypical induction mechanisms.

MSC-1186, a Highly Selective Pan-SRPK Inhibitor Based on an Exceptionally Decorated Benzimidazole-Pyrimidine Core

The highly conserved catalytic sites in protein kinases make it difficult to identify ATP competitive inhibitors with kinome-wide selectivity. Serendipitously, during a dedicated fragment campaign for the focal adhesion kinase (FAK), a scaffold that had lost its initial FAK affinity showed remarkable potency and selectivity for serine-arginine-protein kinases 1-3 (SRPK1-3). Non-conserved interactions with the uniquely structured hinge region of the SRPK family were the key drivers of the exclusive selectivity of the discovered fragment hit. Structure-guided medicinal chemistry efforts led to the SRPK inhibitor MSC-1186, which fulfills all hallmarks of a reversible chemical probe, including nanomolar cellular potency and excellent kinome-wide selectivity. The combination of MSC-1186 with CDC2-like kinase (CLK) inhibitors showed additive attenuation of SR-protein phosphorylation compared to the single agents. MSC-1186 and negative control (MSC-5360) are chemical probes available via the Structural Genomics Consortium chemical probe program (https://www.sgc-ffm.uni-frankfurt.de/).

Synthesis and crystal structure of rac-2-(1,3-dioxo-isoindolin-2-yl)ethyl 4-methyl-N-phenyl-N'-(tri-iso-propyl-sil-yl)benzene-sulfondiimidoate: the first member of a new substance class

The title compound {systematic name: rac-2-[7-methyl-4-(4-methylphenyl)-4-(phenylimino)-6,6-bis(propan-2-yl)-3-oxa-4λ⁶-thia-5-aza-6-silaoct-4-en-1-yl]-2,3-dihydro-1H-isoindole-1,3-dione}, C₃₂H₄₁N₃O₃SSi, was synthesized by desoxychlorination of 4-methyl-N-phenyl-N'-(triisopropyl-sil-yl)benzene-sul-fon-imid-am-ide and subsequent reaction with 2-(2-hy-droxy-eth-yl)isoindoline-1,3-dione. The racemic compound was crystallized from isopropanol. The structural characterization by single-crystal X-ray diffraction revealed two double-bonded nitro-gen atoms to the central sulfur atom and an overall crystal packing driven by its aromatic inter-actions.

Optimization of TEAD P-Site Binding Fragment Hit into In Vivo Active Lead

The dysregulated Hippo pathway and, consequently, hyperactivity of the transcriptional YAP/TAZ-TEAD complexes is associated with diseases such as cancer. Prevention of YAP/TAZ-TEAD triggered gene transcription is an attractive strategy for therapeutic intervention. The deeply buried and conserved lipidation pocket (P-site) of the TEAD transcription factors is druggable. The discovery and optimization of a P-site binding fragment (1) are described. Utilizing structure-based design, enhancement in target potency was engineered into the hit, capitalizing on the established X-ray structure of TEAD1. The efforts culminated in the optimized in vivo tool MSC-4106, which exhibited desirable potency, mouse pharmacokinetic properties, and in vivo efficacy. In close correlation to compound exposure, the time- and dose-dependent downregulation of a proximal biomarker could be shown.

Requirements for quality assurance from the directive REI Mining and other regulations

Many requirements for the quality assurance of the licensee and the independent measuring centre can be derived from the Directive for the “Surveillance of emission and immission of mining work” (REI Mining). However, these should be viewed within the context of “Instructions of measurement related to the surveillance of radioactivity in the environment and to the registration of radioactive emissions from nuclear installations” (MA). Further, it would be advisable to compare the REI Mining requirements to both the Directive for the “Surveillance of emission and immission from nuclear installations” (REI) as well as to the “General administration order to the integrated measuring and information system of the precautionary Radiation Protection Act” (AVV-IMIS). In this article, the various requirements are compared, their common and different aspects are discussed, and possible conclusions for the licensee, the independent measuring centre and the authority of supervision and licencing are presented.

Coexistence of antithrombin deficiency and suspected inferior vena cava atresia in an adolescent and his mother - case report and clinical implications

Background

Antithrombin deficiency (ATD) is an autosomal dominant thrombophilia presenting with varying phenotypes. In pediatric patients with ATD, thrombosis typically develops during the neonatal period or adolescence. However, to date there are no consistent recommendations on the therapeutic management of children with ATD. Inferior vena cava atresia (IVCA) belongs to a range of congenital or acquired vena cava malformations and is described as an independent risk factor for thrombosis.

The present case report explores two cases of combined ATD and IVCA in an adolescent and his mother.

Case presentation

A 14-year-old male presented with extensive deep venous thromboses (DVTs) of both lower extremities as well as an IVCA. The patient had previously been diagnosed with an asymptomatic ATD without therapeutic consequences at that time. His mother was suffering from an ATD and had herself just been diagnosed with IVCA, too.

The DVTs in the adolescent were treated by systemic anticoagulation and catheter-directed local thrombolysis causing favourable results. Yet, despite adequate oral anticoagulation the DVTs in both lower extremities reoccurred within 1 week after the patient was discharged from hospital. This time, thrombolysis could not be fully achieved. Surprisingly, probing and stenting of the IVCA was achieved, indicating an acquired IVCA which could have occurred after undetected thrombosis in early childhood.

Genetic analyses showed the same mutation causing ATD in both son and mother: heterozygote missense mutation c.248 T > C, p.(Leu83Pro), within the heparin binding domain of antithrombin. This mutation was never reported in mutation databases before.

Conclusions

To our knowledge this is the first case report discussing combined ATD and IVCA in two family members. Since ATDs present with clinical heterogeneity, taking a thorough family history is crucial for the anticipation of possible complications in affected children and decisions on targeted diagnostics and therapeutic interventions. Affected families must be educated on risk factors and clinical signs of thrombosis and need an immediate diagnostic workup in case of clinical symptoms. IVCA in patients with ATD could occur due to thrombotic occlusion at a very early age. Therefore, in case of family members with IVCA and ATD ultrasound screening in newborns should be considered.

Discovery of 5-{2-[5-Chloro-2-(5-ethoxyquinoline-8-sulfonamido)phenyl]ethynyl}-4-methoxypyridine-2-carboxylic Acid, a Highly Selective in Vivo Useable Chemical Probe to Dissect MCT4 Biology

Due to increased lactate production during glucose metabolism, tumor cells heavily rely on efficient lactate transport to avoid intracellular lactate accumulation and acidification. Monocarboxylate transporter 4 (MCT4/SLC16A3) is a lactate transporter that plays a central role in tumor pH modulation. The discovery and optimization of a novel class of MCT4 inhibitors (hit 9a), identified by a cellular screening in MDA-MB-231, is described. Direct target interaction of the optimized compound 18n with the cytosolic domain of MCT4 was shown after solubilization of the GFP-tagged transporter by fluorescence cross-correlation spectroscopy and microscopic studies. In vitro treatment with 18n resulted in lactate efflux inhibition and reduction of cellular viability in MCT4 high expressing cells. Moreover, pharmacokinetic properties of 18n allowed assessment of lactate modulation and antitumor activity in a mouse tumor model. Thus, 18n represents a valuable tool for investigating selective MCT4 inhibition and its effect on tumor biology.

Structure-kinetic relationship reveals the mechanism of selectivity of FAK inhibitors over PYK2

There is increasing evidence of a significant correlation between prolonged drug-target residence time and increased drug efficacy. Here, we report a structural rationale for kinetic selectivity between two closely related kinases: focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2). We found that slowly dissociating FAK inhibitors induce helical structure at the DFG motif of FAK but not PYK2. Binding kinetic data, high-resolution structures and mutagenesis data support the role of hydrophobic interactions of inhibitors with the DFG-helical region, providing a structural rationale for slow dissociation rates from FAK and kinetic selectivity over PYK2. Our experimental data correlate well with computed relative residence times from molecular simulations, supporting a feasible strategy for rationally optimizing ligand residence times. We suggest that the interplay between the protein structural mobility and ligand-induced effects is a key regulator of the kinetic selectivity of inhibitors of FAK versus PYK2.

Abstract 3075: Antitumor activity of M8891, a potent and reversible inhibitor of methionine aminopeptidase 2

N-terminal cleavage of methionine by methionine aminopeptidases is a crucial step in the maturation of proteins during protein biosynthesis. MetAP2, one of the two methionine aminopeptidases expressed in mammalian cells, has been identified as the target of the highly potent and irreversible inhibitor fumagillin to which antiangiogenic and antitumoral properties have been ascribed. This and other findings support the rationale to develop MetAP2 inhibitors for cancer therapy. The fumagillin derivative TNP-470 has been evaluated in several clinical trials, but development was discontinued following demonstration of unfavorable pharmacokinetics and side effects likely attributed to the reactivity of the compound. We have developed M8891, an orally bioavailable, potent, and reversible inhibitor of MetAP2. M8891 inhibited growth of primary endothelial cells as well as patient-derived tumor cells and demonstrated antiangiogenic and antitumoral activity in mouse models. Accumulation of an unprocessed MetAP2 substrate, methionylated elongation factor 1 α, Met-EF1a, was observed upon treatment with M8891 in vitro as well as in vivo confirming that MetAP2 can be effectively inhibited with this compound. In combination with sunitinib, M8891 demonstrated strong and durable antitumor activity in a cohort of patient-derived renal cancer xenografts at well-tolerated exposure levels. Predictive biomarker hypotheses generated from CRISPR sensitivity/resistance screens as well as analyses of molecular profiling data from PDX tumors are currently being evaluated in further nonclinical studies. A dose-escalation phase 1 study in patients with advanced solid tumors is currently ongoing.

Citation Format: Manja Friese-Hamim, Olga Bogatyrova, Maria J. Ortiz, Dirk Wienke, Timo Heinrich, Felix Rohdich, Klaus Duecker, Christoph Schultes, Bayard Huck, Frank T. Zenke, Andree Blaukat. Antitumor activity of M8891, a potent and reversible inhibitor of methionine aminopeptidase 2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3075.

Higher-order risk preferences in social settings

We study prudence and temperance (next to risk aversion) in social settings. Previous experimental studies have shown that these higher-order risk preferences affect the choices of individuals deciding privately on lotteries that only affect their own payoff. Yet, many risky and financially relevant decisions are made in the social settings of households or organizations. We elicit higher-order risk preferences of individuals and systematically vary how an individual's decision is made (alone or while communicating with a partner) and who is affected by the decision (only the individual or the partner as well). In doing so, we can isolate the effects of other-regarding concerns and communication on choices. Our results reveal that the majority of choices are risk averse, prudent, and temperate across social settings. We also observe that individuals are influenced significantly by the preferences of a partner when they are able to communicate and choices are payoff-relevant for both of them.

Targeted ED-B fibronectin SPECT in vivo imaging in experimental atherosclerosis

AIM

The extracellular matrix protein ED-B fibronectin (ED-B) is upregulated in inflammatory atherosclerotic lesions. However, functional in vivo imaging of ED-B-containing plaques has not been explored. This study evaluated whether [(99m)Tc]-conjugated AP39 ([(99m)Tc]-AP39), a single-chain antibody specific to ED-B, can be used for in vivo detection of atherosclerotic plaques in Western diet (WD)-fed, apolipoprotein E-deficient (apoE-/-) mice as compared to wildtype (WT) control mice.

METHODS

Using SPECT, 12-month-old WD-fed apoE-/- and WT mice were studied 4 hours after injecting [(99m)Tc]-AP39 (148 MBq). Subsequently, mice were sacrificed, thoracic aortas measured in a g-counter, and plaques analyzed using histology, immuno-histochemistry, autoradiography, and morphometry.

RESULTS

In vivo [(99m)Tc]-AP39-SPECT imaging of apoE-/- mice demonstrated a significant signal activity in the plaque-ridden thoracic aorta (52.236 ± 40.646 cpm/cm³) that co-localized with the aortic arch and the supra-aortic arteries in MRI scans. Low signal activity (9.468 ± 4.976 cpm/cm³) was observed in WT mice. In apoE-/- mice, the strongest signals were detected in the aortic root, aortic arch and along the abdominal aorta. Autoradiography analysis of aortas from apoE-/- mice confirmed the in vivo observation by demonstrating signal localization in atherosclerotic plaques. The size of autoradiography-positive plaque areas correlated significantly with the size of ED-B-positive (r=0.645, P=0.044) or macrophage-infiltrated (r=0.84, P<0.002) plaques. A significant correlation was found between the sizes of ED-B-positive and macrophage-infiltrated plaque areas (r=0.93, P<0.01).

CONCLUSION

[(99m)Tc]-AP39-SPECT in vivo imaging detects inflammatory plaque lesions in WD-fed apoE-/- mice.

The revised program for measurements in intense operation mode according to AVV-IMIS

The monitoring program for measurements in intense operation mode has been revised recently by a working group at the Federal Ministry for Environment, Nature Conservation and Reactor Safety (BMU). The major issues of the revision are reported in this contribution. Measurements in intense operation must be appropriate for fast assessment of the radiological situation, for estimating the dose to the population and for decisions on countermeasures to minimize the dose. In order to meet these requirements the structure of the measurement program in intense operation mode was divided into three phases when different exposition paths are relevant: before and during dispersion of radioactive material, immediately after dispersion of radioactive material has ended and a late phase when contamination values have decreased in different environmental media. For each of these phases a special measurement program was defined that is tailored to achieve the above mentioned objectives. Minimum detectable activity concentrations were introduced similar to the measurement program in routine operation mode. They follow the intervention levels in the catalogue of countermeasures and maximum permitted values given by the European Union (EU) for food and animal feed. The minimum detectable activity concentrations were defined such that the detection of 1/10 of the intervention levels for countermeasures is ensured.

Optimization of the selection of analysis methods for the determination of naturally occurring radionuclides

The determination of naturally occurring radionuclides in the environment is a complex problem. Particularly the optimization of the analysis methods is very important, while the choice of the method influences the financial and personnel resources, as well as the quality of the results. This work is prepared from a working group within the working group(suggest instead use Research Group) “natural radioactivity” of the German-Swiss radiation protection association (FS). It is a recommendation for clients of existing laboratories, as well as new or renovated laboratories, which order measurements. This article shows some excerpts of the full work.

Fragment-based discovery of new highly substituted 1H-pyrrolo[2,3-b]- and 3H-imidazolo[4,5-b]-pyridines as focal adhesion kinase inhibitors

Focal adhesion kinase (FAK) is considered as an attractive target for oncology, and small-molecule inhibitors are reported to be in clinical testing. In a surface plasmon resonance (SPR)-mediated fragment screening campaign, we discovered bicyclic scaffolds like 1H-pyrazolo[3,4-d]pyrimidines binding to the hinge region of FAK. By an accelerated knowledge-based fragment growing approach, essential pharmacophores were added. The establishment of highly substituted unprecedented 1H-pyrrolo[2,3-b]pyridine derivatizations provided compounds with submicromolar cellular FAK inhibition potential. The combination of substituents on the bicyclic templates and the nature of the core structure itself have a significant impact on the compounds FAK selectivity. Structural analysis revealed that the appropriately substituted pyrrolo[2,3-b]pyridine induced a rare helical DFG-loop conformation. The discovered synthetic route to introduce three different substituents independently paves the way for versatile applications of the 7-azaindole core.

Live-born trisomy 22: patient report and review

Trisomy 22 is a common trisomy in spontaneous abortions. In contrast, live-born trisomy 22 is rarely seen due to severe organ malformations associated with this condition. Here, we report on a male infant with complete, non-mosaic trisomy 22 born at 35 + 5 weeks via caesarean section. Peripheral blood lymphocytes and fibroblasts showed an additional chromosome 22 in all metaphases analyzed (47,XY,+22). In addition, array CGH confirmed complete trisomy 22. The patient's clinical features included dolichocephalus, hypertelorism, flattened nasal bridge, dysplastic ears with preauricular sinuses and tags, medial cleft palate, anal atresia, and coronary hypospadias with scrotum bipartitum. Essential treatment was implemented in close coordination with the parents. The child died 29 days after birth due to respiratory insufficiency and deterioration of renal function. Our patient's history complements other reports illustrating that children with complete trisomy 22 may survive until birth and beyond.

Abstract P2-10-17: SET index predicts response to endocrine therapy rather than prognosis independently of other genomic signatures in a blinded validation study

Background: A genomic index for sensitivity to endocrine therapy (SET) was previously derived from genes strongly positively and negatively coexpressed with estrogen receptor (Symmans et al. 2010, JCO 28:4111). This SET index has been reported to predict survival benefit from adjuvant endocrine therapy independently of prognosis.

Materials and Methods: Affymetrix gene expression profiling was performed on 307 ER positive primary breast cancers from a retrospective cohort treated solely with endocrine therapy. In a blinded study the SET index' ability to predict survival was analyzed in this previously unpublished dataset. Affymetrix profiles (CEL files) were anonymized and provided to the developers of SET index (Nuvera Biosciences) without any clinical information. The 261 profiles that passed QC were categorized into SET classes based on the published prespecified cutoffs. Samples categorized as ER negative based on gene expression were excluded. Subsequently classifications were unblinded and clinical associations analyzed according to a predefined protocol. Exploratory analyses were performed on the relationship of SET index to other genomic signatures. We also assessed a potential pure prognostic value of SET index in an additional dataset of 164 node negative ER positive patients that did not receive any adjuvant treatment.

Results: A lower SET index significantly correlated with higher grade (p = 0.009) and negative PgR status (p = 0.016). We detected no significant differences for age, tumor size, lymph node status, and HER2 status between patients with high, intermediate, and low SET index. In the lymph node negative (LNN) cohort (n = 120) we observed a significant difference in DFS (5yr DFS 77.1±10.2% vs 94.4±2.2%; HR 4.20, 95% CI 1.72–10.2; p = 0.002) and DMFS (HR 3.18, 95% CI 1.20–8.47; p = 0.020) for patients with low SET index. In contrast, we found no prognostic value of SET index in lymph node positive patients (n = 95). In multivariate analyses of LNN patients including SET, age, tumor size, histological grade, and PgR status, only SET was significantly associated with DFS (HR 3.37, 95% CI 1.25–9.01; p = 0.016) and DMFS (HR 3.03, 95% CI 1.08–8.55; p = 0.036). In exploratory analyses SET index was not correlated to other genomic signatures related to proliferation (as Recurrence Score, GGI, and NKI70) or immune response (e.g. 7IGS, SDPP). When we included all these genomic signatures as continous scores in a multivariate stepwise Cox regression model in the LNN endocrine treated cohort, only SET remained as significant (p = 0.025) while Recurrence Score displayed a strong trend (p = 0.054). We also verified that SET had no pure prognostic value in an additional dataset of 164 ER positive patients that did not receive any adjuvant treatment.

Conclusions: In a blinded analysis the predictive ability of SET index was prospectively validated in an independent cohort of node-negative patients. Our exploratory analysis demonstrates that SET index is unrelated to other genomic signatures and delivers independent information on the response of patients to endocrine therapy rather than prognosis.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-17.

T-cell receptor diversity prevents T-cell lymphoma development

Mature T-cell lymphomas (MTCLs) have an extremely poor prognosis and are much less frequent than immature T-cell leukemias. This suggests that malignant outgrowth of mature T lymphocytes is well controlled. Indeed, in a previous study we found that mature T cells are resistant to transformation with known T-cell oncogenes. Here, however, we observed that T-cell receptor (TCR) mono-/oligoclonal mature T cells from TCR transgenic (tg) mice (OT-I, P14) expressing the oncogenes NPM/ALK or ΔTrkA readily developed MTCLs in T-cell-deficient recipients. Analysis of cell surface markers largely ruled out that TCR tg lymphomas were derived from T-cell precursors. Furthermore, cotransplanted non-modified TCR polyclonal T cells suppressed malignant outgrowth of oncogene expressing TCR tg T lymphocytes. A dominant role of an anti-leukemic immune response or Tregs in the control of MTCLs seems unlikely as naïve T cells derived from oncogene expressing stem cells, which should be tolerant to leukemic antigens, as well as purified CD4 and CD8 were resistant to transformation. However, our results are in line with a model in which homeostatic mechanisms that stabilize the diversity of the normal T-cell repertoire, for example, clonal competition, also control the outgrowth of potentially malignant T-cell clones. This study introduces a new innate mechanism of lymphoma control.

Allosteric IGF-1R Inhibitors

Targeting allosteric protein sites is a promising approach to interfere selectively with cellular signaling cascades. We have discovered a novel class of allosteric insulin-like growth factor-I receptor (IGF-1R) inhibitors. 3-Cyano-1H-indole-7-carboxylic acid {1-[4-(5-cyano-1H-indol-3-yl)butyl]piperidin-4-yl}amide (10) was found with nanomolar biochemical, micromolar, cellular IGF-1R activity and no relevant interference with cellular insulin receptor signaling up to 30 μM. The allosteric binding site was characterized by X-ray crystallographic studies, and the structural information was used to explain the unique mode of action of this new class of inhibitors.

Phthalates in house dust

The main objective of this study was to generate a fast analytical method to determine the five phthalates benzylbutylphthalate (BBP), dibutylphthalate (DBP), di-(2-ethylhexyl)-phthalate (DEHP), di-isodecylphthalate (DIDP), and di-isononylphthalate (DINP) in house dust. To achieve this liquid chromatography electrospray tandem mass spectrometry (LC-ESI-MS/MS) was used for measurement. The risk of lab- and cross-contamination was nearly eliminated completely as a very short and fast sample preparation including a sieving step and an ultrasonic extraction for the analytes from the dust samples was used. Quantification through internal standard calibration resulted in low limits of determination (DEHP 4 mg kg(-1) to DBP 14 mg kg(-1)). A potential interaction between the analytes DIDP and DINP during chromatographic measurement could be excluded while performing a two level factorial design. Furthermore it was examined to what extend carpet and plastic materials respectively have influence on the total amount of phthalates in dust. It could be shown that apartments in which a minimum of both of these sources appeared revealed the lowest total amount of sum of phthalates in dust (median 362 mg kg(-1)).

Asymmetric synthesis of highly substituted azapolycyclic compounds via 2-alkenyl sulfoximines: potential scaffolds for peptide mimetics

The application of metalated, enantiomerically pure acyclic and cyclic 2-alkenyl sulfoximines for the synthesis of highly substituted aza(poly)cyclic ring systems is described. The method relies on a one-pot combination of a reagent-controlled allyl transfer reaction to alpha- or beta-amino aldehydes, followed by a Michael-type cyclization of the intermediate vinyl sulfoximines generated in the first step. The sulfur-free target compounds are preferentially obtained by samarium iodide treatment of the sulfonimidoyl substituted heterocycles. In addition to this methodological work, initial results on the biological activity of selected examples are reported. Furthermore, a concept for the transformation of peptidic lead structures into non-peptide mimetics is described, and the relevance of the new approach to highly substituted azaheterocycles in this context is discussed.

1-(1-Phenethylpiperidin-4-yl)-1-phenylethanols as Potent and Highly Selective 5-HT2A Antagonists

The discovery of a novel class of highly potent and selective 5-HT2A antagonists is reported herein. Selectivity for the serotonin 5-HT2A receptor was optimized, decreasing the affinity of these antagonists toward the adrenergic alpha1 and dopaminergic D2 receptors, and especially to the 5-HT2C receptor. A series of corresponding 7-substituted indoles is described for the first time as serotonergic ligands. The enantiomer R-(+)-1-(4-fluorophenyl)-1-{1-[2-(4-fluorophenyl)ethyl]piperidin-4-yl} ethanol (R-(+)-74) was identified to have superior affinity for the serotonergic 5-HT2A receptor [IC50=0.37 nM] and selectivity toward the dopaminergic D2- [IC50=2300 nM], adrenergic alpha1- [IC50=1000 nM] and 5-HT2C receptors [IC50=490 nM].

Dual 5-HT1A agonists and 5-HT re-uptake inhibitors by combination of indole-butyl-amine and chromenonyl-piperazine structural elements in a single molecular entity

The dual serotonin (5-HT) re-uptake inhibitor and 5-HT(1A) receptor agonist vilazodone was found to increase central serotonin levels in rat brain. In the course of structural modifications of vilazodone 3-[4-[4-(2-oxo-2H-1-benzopyran-6-yl)-1-piperazinyl]-butyl]-1H-indole-5-carbonitrile 8i and its fluorine analogue 6-[4-[4-(5-fluor-3-indolyl)-butyl]-1-piperazinyl]-2H-1-benzopyran-2-one have been identified. These unsubstituted chromenones are equally potent at the 5-HT(1A) receptor and 5-HT transporter. The implementation of nitrogen functionalities in position 3 of the chromenones resulted in compounds acting as agonists at the 5-HT(1A) receptor and as 5-HT re-uptake inhibitors like vilazodone. Ex vivo 5-HT re-uptake inhibition and in vitro 5-HT agonism were determined in the PCA- and GTPgammaS-assay, respectively. The potential of these chromenones to increase central 5-HT levels was measured in microdialysis studies and especially the derivatives 3-[4-[4-(3-amino-2-oxo-2H-chromen-6-yl)-piperazin-1-yl]-butyl]-1H-indole-5-carbonitrile 8f, ethyl (6-[4-[4-(5-cyano-1H-indol-3-yl)-butyl]-piperazin-1-yl]-2-oxo-2H-chromen-3-yl)-carbamate 8h and N-(6-[4-[4-(5-cyano-1H-indol-3-yl)-butyl]-piperazin-1-yl]-2-oxo-2H-chromen-3-yl)-acetamide 8k give rise to rapid development of increased serotonin levels in rat brain cortex, lasting longer than 3h.

Indolebutylamines as Selective 5-HT1A Agonists

A series of new 1-[4-(indol-3-yl)butyl]-4-arylpiperazines was prepared to identify highly selective and potent 5-HT(1A) agonists as potential pharmacological tools in studies of mood disorders. The combination of structural elements (indole-alkyl-amine and aryl-piperazine) known to introduce 5-HT(1A) receptor affinity and the proper selection of substituents (R on the indole moiety and R' on the aryl moiety) led to compounds with high receptor specificity and affinity. In particular, the introduction of the methyl ether or the unsubstituted carboxamide as substituents in position 5 of the indole (R) guaranteed serotonergic 5-HT(1A) affinity compared to the unsubstituted analogue. Para-substituted arylpiperazines (R') decreased dopaminergic D(2) binding and increased selectivity for the 5-HT(1A) receptor. Agonistic 5-HT(1A) receptor activity was confirmed in vivo in the ultrasonic vocalization test, and the results suggest that the introduction of the carboxamide residue leads to better bioavailability than the corresponding methyl ether. 3-[4-[4-(4-Carbamoylphenyl)piperazin-1-yl]butyl]-1H-indole-5-carboxamide 54 was identified as a highly selective 5-HT(1A) receptor agonist [GTPgammaS, ED(50) = 4.7 nM] with nanomolar 5-HT(1A) affinity [IC(50) = 0.9 nM] and selectivity [D(2), IC(50) > 850 nM]. 3-[4-[4-(4-Methoxyphenyl)piperazin-1-yl]butyl]-1H-indole-5-carboxamide 45 is one of the most potent and selective 5-HT(1A) agonists known [5-HT(1A), IC(50) = 0.09 nM; D(2), IC(50) = 140 nM].

Synthesis and Structure−Activity Relationship in a Class of Indolebutylpiperazines as Dual 5-HT1A Receptor Agonists and Serotonin Reuptake Inhibitors

Systematic structural modifications of indolealkylphenylpiperazines led to improved selectivity and affinity within this class of 5-HT(1A) receptor agonists. Introduction of electron-withdrawing groups in position 5 on the indole raises serotonin transporter affinity, and the cyano group proved to be the best substituent here. 5-Fluoro and 5-cyano substituted indoles show comparable results in in vitro and in vivo tests, and bioisosterism between these substituents was supported by calculation of the molecular electrostatic potentials and dipole moments. Compounds showing promising in vitro data were further examined in ex vivo (p-chloroamphetamine assay) and in vivo (ultrasonic vocalization) tests. Optimization of the arylpiperazine moiety indicated that the 5-benzofuranyl-2-carboxamide was best suited to increase 5-HT transporter and 5-HT(1A) receptor affinity and to suppress D(2) receptor binding. 5-[4-[4-(5-Cyano-3-indolyl)butyl]-1-piperazinyl]benzofuran-2-carboxamide 29 (vilazodone, EMD 68843) was identified as a highly selective 5-HT(1A) receptor agonist [GTPgammaS, ED(50) = 1.1 nM] with subnanomolar 5-HT(1A) affinity [IC(50) = 0.2 nM] and as a subnanomolar 5-HT reuptake inhibitor [RUI = 0.5 nM] showing a great selectivity to other GPCRs (e.g., D(2), IC(50) = 666 nM).

A new synthesis of indole 5-carboxylic acids and 6-hydroxy-indole-5-carboxylic acids in the preparation of an o-hydroxylated metabolite of vilazodone

A major metabolite of the potential antidepressant vilazodone formed in rat, dog, monkey and human liver microsomes is the 5-cyano-6-hydroxy-1H-indole derivative. For the construction of the salicyl-like substituted indole we adapted a synthesis of carmoxirole using Japp-Klingemann type Fischer-indole synthesis protocols. Functional group interconversion of carboxylic acid via carboxamide into cyanide was performed with methanesulfonic acid chloride.

Biologically Active Compounds through Catalysis: Efficient Synthesis ofN-(Heteroarylcarbonyl)-N′-(arylalkyl)piperazines

A practical route for the synthesis of new biologically active 5-HT(2 A) receptor antagonists has been developed. In only three catalytic steps, this class of central nervous system (CNS) active compounds can be synthesized efficiently with high diversity. As the initial step, an anti-Markovnikov addition of amines to styrenes provides an easy route to N-(arylalkyl)piperazines, which constitute the core structure of the active molecules. Here, base-catalyzed hydroamination reactions of styrenes with benzylated piperazine proceeded in high yield even at room temperature. After catalytic debenzylation, the free amines were successfully carbonylated with different aromatic and heteroaromatic halides and carbon monoxide to yield the desired compounds in good to excellent yields. The two key reactions, base-catalyzed hydroamination of styrenes and palladium-catalyzed aminocarbonylation of haloarenes/heterocycles, showed tolerance towards various functional groups, thereby demonstrating the potential to synthesize a wide variety of new derivatives of this promising class of pharmaceuticals.