13 Cβ-Valine and 13 Cγ-Leucine Methine Labeling To Probe Protein Ligand Interaction

Precise information regarding the interaction between proteins and ligands at molecular resolution is crucial for effectively guiding the optimization process from initial hits to lead compounds in early stages of drug development. In this study, we introduce a novel aliphatic side chain isotope-labeling scheme to directly probe interactions between ligands and aliphatic sidechains using NMR techniques. To demonstrate the applicability of this method, we selected a set of Brd4-BD1 binders and analyzed 1 H chemical shift perturbation resulting from CH-π interaction of Hβ -Val and Hγ -Leu as CH donors with corresponding ligand aromatic moieties as π acceptors.

Synthesis of a 13C-methylene-labeled isoleucine precursor as a useful tool for studying protein side-chain interactions and dynamics

In this study, we present the synthesis and incorporation of a metabolic isoleucine precursor compound for selective methylene labeling. The utility of this novel α-ketoacid isotopologue is shown by incorporation into the protein Brd4-BD1, which regulates gene expression by binding to acetylated histones. High quality single quantum 13C-1 H-HSQC were obtained, as well as triple quantum HTQC spectra, which are superior in terms of significantly increased 13C-T2 times. Additionally, large chemical shift perturbations upon ligand binding were observed. Our study thus proves the great sensitivity of this precursor as a reporter for side-chain dynamic studies and for investigations of CH-π interactions in protein-ligand complexes.

Ligandability assessment of the C-terminal Rel-homology domain of NFAT1

Transcription factors are generally considered challenging, if not "undruggable", targets but they promise new therapeutic options due to their fundamental involvement in many diseases. In this study, we aim to assess the ligandability of the C-terminal Rel-homology domain of nuclear factor of activated T cells 1 (NFAT1), a TF implicated in T-cell regulation. Using a combination of experimental and computational approaches, we demonstrate that small molecule fragments can indeed bind to this protein domain. The newly identified binder is the first small molecule binder to NFAT1 validated with biophysical methods and an elucidated binding mode by X-ray crystallography. The reported eutomer/distomer pair provides a strong basis for potential exploration of higher potency binders on the path toward degrader or glue modalities.

Ligand 1 H NMR Chemical Shifts as Accurate Reporters for Protein-Ligand Binding Interfaces in Solution

The availability of high-resolution 3D structural information is crucial for investigating guest-host systems across a wide range of fields. In the context of drug discovery, the information is routinely used to establish and validate structure-activity relationships, grow initial hits from screening campaigns, and to guide molecular docking. For the generation of protein-ligand complex structural information, X-ray crystallography is the experimental method of choice, however, with limited information on protein flexibility. An experimentally verified structural model of the binding interface in the native solution-state would support medicinal chemists in their molecular design decisions. Here we demonstrate that protein-bound ligand 1 H NMR chemical shifts are highly sensitive and accurate probes for the immediate chemical environment of protein-ligand interfaces. By comparing the experimental ligand 1 H chemical shift values with those computed from the X-ray structure using quantum mechanics methodology, we identify significant disagreements for parts of the ligand between the two experimental techniques. We show that quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) ensembles can be used to refine initial X-ray co-crystal structures resulting in a better agreement with experimental 1 H ligand chemical shift values. Overall, our findings highlight the usefulness of ligand 1 H NMR chemical shift information in combination with a QM/MM MD workflow for generating protein-ligand ensembles that accurately reproduce solution structural data.

Fragment Optimization of Reversible Binding to the Switch II Pocket on KRAS Leads to a Potent, In Vivo Active KRASG12C Inhibitor

Activating mutations in KRAS are the most frequent oncogenic alterations in cancer. The oncogenic hotspot position 12, located at the lip of the switch II pocket, offers a covalent attachment point for KRAS^G12C inhibitors. To date, KRAS^G12C inhibitors have been discovered by first covalently binding to the cysteine at position 12 and then optimizing pocket binding. We report on the discovery of the in vivo active KRAS^G12C inhibitor BI-0474 using a different approach, in which small molecules that bind reversibly to the switch II pocket were identified and then optimized for non-covalent binding using structure-based design. Finally, the Michael acceptor containing warhead was attached. Our approach offers not only an alternative approach to discovering KRAS^G12C inhibitors but also provides a starting point for the discovery of inhibitors against other oncogenic KRAS mutants.

A selective and orally bioavailable VHL-recruiting PROTAC achieves SMARCA2 degradation in vivo

Targeted protein degradation offers an alternative modality to classical inhibition and holds the promise of addressing previously undruggable targets to provide novel therapeutic options for patients. Heterobifunctional molecules co-recruit a target protein and an E3 ligase, resulting in ubiquitylation and proteosome-dependent degradation of the target. In the clinic, the oral route of administration is the option of choice but has only been achieved so far by CRBN- recruiting bifunctional degrader molecules. We aimed to achieve orally bioavailable molecules that selectively degrade the BAF Chromatin Remodelling complex ATPase SMARCA2 over its closely related paralogue SMARCA4, to allow in vivo evaluation of the synthetic lethality concept of SMARCA2 dependency in SMARCA4-deficient cancers. Here we outline structure- and property-guided approaches that led to orally bioavailable VHL-recruiting degraders. Our tool compound, ACBI2, shows selective degradation of SMARCA2 over SMARCA4 in ex vivo human whole blood assays and in vivo efficacy in SMARCA4-deficient cancer models. This study demonstrates the feasibility for broadening the E3 ligase and physicochemical space that can be utilised for achieving oral efficacy with bifunctional molecules.

Protein degraders are an emerging drug modality; however, their properties lie beyond typical drug-like space. Here the authors report optimisation via structure-based exit vector and linker design towards the VHL-recruiting PROTAC ACBI2, an orally bioavailable and selective degrader of SMARCA2.

Incidence and clinical outcome of primary carcinomas of the major salivary glands: 10-year data from a population-based state cancer registry in Germany

PURPOSE

The aim of this project was to provide an overview of the epidemiology of primary salivary gland carcinomas (SGC) in terms of incidence, distribution of clinicopathological features and survival in one of the largest cancer registries in Europe.

METHODS

Data were collected from patients with SGC of the major salivary glands registered in the population-based state cancer registry (Landeskrebsregister LKR) in North Rhine-Westphalia (NRW), Germany from 01/01/2009 to 12/31/2018. Age standardization of incidence was performed and relative survival estimates were computed by sex, histological group, age group and T-, N-, and M-stage.

RESULTS

A total of 1680 patients were included in this analysis. The most frequent tumor localization was the parotid gland (78%). Adenocarcinoma (not otherwise specified) was the most common tumor entity (18.5%). Most tumors were found in stages T1-T3 (29% T1; 29% T2; 28% T3). The age-standardized incidence rate (ASR) for SGC was 0.65/100,000 and remained stable during the observation period. There was an age-dependent incidence increasing especially from the age 70 years and onwards. The overall 5-year relative survival (RS) for all patients with SGC was 69.2%. RS was 80-95.6% for T1-2 stage tumors, 60.3% for T3, 47.3% for T4 stage, 87.4% for N0 and 51.2% for N1-2, 74.4% for M0 and 44.9% for M1.

CONCLUSION

Age-standardized incidence for SGC has been stable for the observed 10-year period. Smaller tumors and those without lymph node or distant metastases had a better RS than more advanced tumors.

Quantifying changes in ambient NOx, O3 and PM10 concentrations in Austria during the COVID-19 related lockdown in spring 2020

During spring 2020, unprecedented changes in local and regional emissions have occurred around the globe due to governmental restrictions associated with COVID-19. Many European countries including Austria issued partial curfews or stay-at-home order policies, which have impacted ambient air quality through reductions in non-essential transportation and energy consumption of industrial sites and work places. Here, we analyse the effect of these measures on ambient concentrations of nitrogen oxides (NO_x), ozone (O₃) and particulate matter (PM₁₀) during the first nationwide lockdown in Austria (16.03.2020 to 14.04.2020). To ensure a robust analysis, the Austrian domain is divided into four individual subsectors contingent on regional climate. For air quality analysis a novel method is applied for filtering days with comparable weather conditions during the 2020 lockdown and spring 2017 to 2019. In general, our analysis shows decreasing pollutant concentrations, although in magnitude dependent on pollutant and regional subdomain. Largest reductions are found for NO_x reaching up to −68% at traffic sites reflecting the substantial decrease in non-essential transport. Changes in the O₃ concentrations at background sites show a rather weak response to NO_x declines varying between roughly −18 to +8% for both the median and the upper tail of the distribution. Occasional site level increases in O₃ concentrations can be attributed to comparably weak titration during night-time. PM₁₀ concentrations show the smallest response among air pollutants, attributable to manifold precursor sources not affected by the lockdown measures. However, our analysis indicates also a shift of PM₁₀ distributions at traffic sites closer to distributions observed at background sites.

A-04 Acute Sports-Related Concussion Associations Between Cognitive Symptoms, Memory Performance, and Default Mode Network Hub Connectivity

Purpose: Disruptions in cognitive performance are commonly reported after a sports-related concussion (SRC) and may be related to brain network changes, particularly within the default mode network (DMN). Since well-connected brain regions across networks (hubs) play an important role in network organization, we hypothesize that DMN hubs will be disrupted after a SRC and associated with cognitive symptoms and cognitive performance. Methods: We collected resting-state fMRI, symptoms, and cognitive performance data from 44 student-athletes at baseline, after a SRC, and at recovery. Participation coefficient defined hubs for each athlete. We compared changes in functional connectivity between hubs and non-hubs within the DMN and between DMN hubs and non-hubs in the remaining networks. We used linear regression to examine the relationship between functional connectivity, cognitive symptoms, and cognitive performance while controlling for concussion history. Results: Functional connectivity between hubs and non-hubs within the DMN increased from baseline to post-injury and decreased from post-injury to recovery, but not to baseline connectivity levels. Post-injury functional connectivity was related to increased cognitive symptoms and decreased visual memory performance. Functional connectivity decreased between hubs in the DMN and non-hubs in the cingulo-opercular, salience, somatomotor, and visual networks from baseline to post-injury. Cognitive symptoms and visual memory performance were related to functional connectivity between DMN hubs and visual network non-hubs. Conclusions: Self-reported cognitive symptoms and cognitive performance were associated with changes in DMN hub connectivity. This relationship may suggest a decrease in efficiency between brain networks after a SRC and may provide insight into post-injury compensation during task performance.

Is Mini Beam Ready for Human Trials? Results of Randomized Study of Treating De-Novo Brain Tumors in Canines Using Linear Accelerator Generated Mini Beams

The main challenge in treating malignant brain neoplasms lies in eradicating the tumor while minimizing treatment-related damage. Conventional radiation treatments are associated with considerable side effects. Synchrotron generated micro-beam radiation (SMBRT) has shown to preserve brain architecture while killing tumor cells, however physical characteristics and limited facility access restrict its use. We have created a new clinical device which produces mini beams on a linear accelerator, to provide a new type of treatment called mini-beam radiation therapy (MBRT). The objective of this study is to compare the treatment outcomes of linear accelerator based MBRT versus standard radiation treatment (SRT), to evaluate the tumor response and the treatment-related changes in the normal brain with respect to each treatment type. Pet dogs with de-novo brain tumors were accrued for treatment. Dogs were randomized between standard fractionated stereotactic (9 Gy in 3 fractions) radiation treatment vs. a single fraction of MBRT (26 Gy mean dose). Dogs were monitored after treatment for clinical assessment and imaging. When the dogs were euthanized, a veterinary pathologist assessed the radiation changes and tumor response. We accrued 16 dogs, 8 dogs in each treatment arm. In the MBRT arm, 71% dogs achieved complete pathological remission. The radiation-related changes were all confined to the target region. Structural damage was not observed in the beam path outside of the target region. In contrast, none of the dogs in control group achieved remission and the treatment related damage was more extensive. Therapeutic superiority was observed with MBRT, including both tumor control and the normal structural preservation. The MBRT findings are suggestive of an immune related mechanism which is absent in standard treatment. These findings together with the widespread availability of clinical linear accelerators make MBRT a promising research topic to explore further treatment and clinical trial opportunities.

Expression of Mucins in Different Entities of Salivary Gland Cancer: Highest Expression of Mucin-1 in Salivary Duct Carcinoma : Mucin-1 - highest expression in Salivary Duct Carcinoma

Therapeutic options for advanced salivary gland cancer (SGC) are rare. Therefore, it was the aim of this study to investigate the extent and intensity of Mucin-1 (MUC1), Mucin-16 (MUC16), and Mucin-5AC (MUC5AC) as potential molecular targets using immunohistochemistry. The medical records of all patients who underwent primary surgery for salivary gland cancer with curative intent in a tertiary referral center between 1990 and 2018 were reviewed. Immunohistochemical staining for MUC1, MUC16, and MUC5AC was performed for all patients with sufficient formalin-fixed paraffin-embedded material, and a semi-quantitative combined score derived from the H-score for the cytoplasmatic, the membranous and the apical membrane was built for the most common entities of SGC. 107 patients with malignancies of the parotid (89.7%) and the submandibular gland (10.3%) were included. The most common entities were mucoepidermoid carcinoma (MuEp; n = 23), adenoid cystic carcinoma (AdCy; n = 22), and salivary duct carcinoma (SaDu; n = 21). The highest mean MUC1 combined score was found in SaDu with 223.6 (±91.7). The highest mean MUC16 combined score was found in MuEp with 177.0 (±110.0). The mean MUC5AC score was low across all entities. A higher MUC1 combined score was significantly associated with male gender (p = 0.03), lymph node metastasis (p < 0.01), lymphovascular invasion (p = 0.045), and extracapsular extension (p = 0.03). SaDu patients with MUC16 expression showed a significantly worse 5-year progression-free survival than those without MUC16 expression (p = 0.02). This is the first study to give a comprehensive overview of the expression of MUC1, MUC16, and MUC5AC in SGC. Since advanced SGCs lack therapeutic options in many cases, these results warrant in vitro research on therapeutic targets against MUC1 in SaDu cell lines and xenograft models.

Measurements of Argon-39 from locations near historic underground nuclear explosions

Measurement of radioactive gas seepage from an underground nuclear explosion is one of the primary methods to confirm whether an event was nuclear in nature. Radioactive noble gas indicators that are commonly targeted by such measurements (e.g. ¹³³Xe, ³⁷Ar) have half-lives of 35 days or less. Argon-39, an activation product similar to ³⁷Ar, is produced by the interaction between neutrons and potassium in the surrounding geology and has a half-life of 269 years. Measurements taken at three sites near three historic underground nuclear test locations at the Nevada National Security Site have all shown highly elevated levels of ³⁹Ar in soil gas decades after the test events. Elevated levels of ³⁹Ar were also detected in atmospheric air collected near two of these sites, and outside the entrance of the one tunnel site. These measurements demonstrate that ³⁹Ar has the potential to be a long-term signature of an underground nuclear event which can be reliably detected at the surface or in the shallow subsurface. This radionuclide detection of an underground nuclear event decades after the event takes place is in contrast to the commonly held assumption that detecting underground nuclear events via radionuclides at the surface needs to be done in a matter of months. Depending upon what further studies show about the robustness of this signature in a variety of geological settings, it may in fact be easy to detect underground nuclear events at the surface for a very long time post-detonation.

A Step toward NRF2-DNA Interaction Inhibitors by Fragment-Based NMR Methods

The NRF2 transcription factor is a key regulator in cellular oxidative stress response, and acts as a tumor suppressor. Aberrant activation of NRF2 has been implicated in promoting chemo-resistance, tumor growth, and metastasis by activating its downstream target genes. Hence, inhibition of NRF2 promises to be an attractive therapeutic strategy to suppress cell proliferation and enhance cell apoptosis in cancer. Direct targeting of NRF2 with small-molecules to discover protein-DNA interaction inhibitors is challenging as it is a largely intrinsically disordered protein. To discover molecules that bind to NRF2 at the DNA binding interface, we performed an NMR-based fragment screen against its DNA-binding domain. We discovered several weakly binding fragment hits that bind to a region overlapping with the DNA binding site. Using SAR by catalogue we developed an initial structure-activity relationship for the most interesting initial hit series. By combining NMR chemical shift perturbations and data-driven docking, binding poses which agreed with NMR information and the observed SAR were elucidated. The herein discovered NRF2 hits and proposed binding modes form the basis for future structure-based optimization campaigns on this important but to date 'undrugged' cancer driver.

Metastases of Cutaneous Squamous Cell Carcinoma Seem to be the Most Frequent Malignancies in the Parotid Gland: A Hospital-Based Study From a Salivary Gland Center

Malignant parotid tumors account for approximately 20% of all parotid lesions. In addition to the various primary parotid lesions there are secondary parotid malignancies, such as metastases or lymphomas. Data on histopathological distribution of all malignancies-including secondary parotid lesions-is limited. Recent evidence indicated a rising surgical incidence of secondary parotid malignancies. This study aims to review the distribution of malignancies in parotid resections from a salivary gland center. A retrospective review of prospectively collected data for all patients who had received parotidectomy between 2014 and 2019 was performed. Histopathological distribution was displayed separately for all parotid malignancies and for primary parotid malignancies. Further, patients` characteristics were compared between benign and malignant parotid lesions and between the two most common malignant parotid lesions. Out of 777 patients, 614 (78.9%) patients had a benign and 164 (21.1%) patients had a malignant parotid lesion. The most common parotid malignancy was metastatic cutaneous squamous cell carcinoma (cSCC) accounting for 35.4% of all parotid malignancies. 71.5% of all malignant lesions were secondary malignancies. Patients with metastatic cSCC were significantly older (p < 0.001) and significantly more likely to be male (p < 0.001) than patients with primary parotid malignancies. No significant difference was found when the lesion size of metastatic cSCC was compared to primary parotid malignancies (p = 0.216). The present study shows the high prevalence of secondary parotid malignancies in patients who had received parotidectomy. Furthermore, it confirms a rising surgical incidence of metastatic cSCC to the parotid gland in a series from a salivary gland center. At this time, parotid surgery for malignant lesions is more likely to be performed for metastases than for primary parotid malignancies.

Getting a Grip on the Undrugged: Targeting β-Catenin with Fragment-Based Methods

Aberrant WNT pathway activation, leading to nuclear accumulation of β‐catenin, is a key oncogenic driver event. Mutations in the tumor suppressor gene APC lead to impaired proteasomal degradation of β‐catenin and subsequent nuclear translocation. Restoring cellular degradation of β‐catenin represents a potential therapeutic strategy. Here, we report the fragment‐based discovery of a small molecule binder to β‐catenin, including the structural elucidation of the binding mode by X‐ray crystallography. The difficulty in drugging β‐catenin was confirmed as the primary screening campaigns identified only few and very weak hits. Iterative virtual and NMR screening techniques were required to discover a compound with sufficient potency to be able to obtain an X‐ray co‐crystal structure. The binding site is located between armadillo repeats two and three, adjacent to the BCL9 and TCF4 binding sites. Genetic studies show that it is unlikely to be useful for the development of protein–protein interaction inhibitors but structural information and established assays provide a solid basis for a prospective optimization towards β‐catenin proteolysis targeting chimeras (PROTACs) as alternative modality.

Intramuscular oxytocin versus Syntometrine® versus carbetocin for prevention of primary postpartum haemorrhage after vaginal birth: a randomised double-blinded clinical trial of effectiveness, side effects and quality of life

OBJECTIVE

To compare intramuscular oxytocin, Syntometrine^® and carbetocin for prevention of postpartum haemorrhage after vaginal birth.

DESIGN

Randomised double-blinded clinical trial.

SETTING

Six hospitals in England.

POPULATION

A total of 5929 normotensive women having a singleton vaginal birth.

METHODS

Randomisation when birth was imminent.

MAIN OUTCOME MEASURES

Primary: use of additional uterotonic agents. Secondary: weighed blood loss, transfusion, manual removal of placenta, adverse effects, quality of life.

RESULTS

Participants receiving additional uterotonics: 368 (19.5%) oxytocin, 298 (15.6%) Syntometrine and 364 (19.1%) carbetocin. When pairwise comparisons were made: women receiving carbetocin were significantly more likely to receive additional uterotonics than those receiving Syntometrine (odds ratio [OR] 1.28, 95% CI 1.08-1.51, P = 0.004); the difference between carbetocin and oxytocin was non-significant (P = 0.78); Participants receiving Syntometrine were significantly less likely to receive additional uterotonics than those receiving oxytocin (OR 0.75, 95% CI 0.65-0.91, P = 0.002). Non-inferiority between carbetocin and Syntometrine was not shown. Use of Syntometrine reduced non-drug PPH treatments compared with oxytocin (OR 0.64, 95% CI 0.42-0.97) but not carbetocin (P = 0.64). Rates of PPH and blood transfusion were not different. Syntometrine was associated with an increase in maternal adverse effects and reduced ability of the mother to bond with her baby.

CONCLUSIONS

Non-inferiority of carbetocin to Syntometrine was not shown. Carbetocin is not significantly different to oxytocin for use of additional uterotonics. Use of Syntometrine reduced use of additional uterotonics and need for non-drug PPH treatments compared with oxytocin. Increased maternal adverse effects are a disadvantage of Syntometrine.

TWEETABLE ABSTRACT

IM carbetocin does not reduce additional uterotonic use compared with IM Syntometrine or oxytocin.

Burden of Spinal Muscular Atrophy (SMA) on Patients and Caregivers in Canada

BACKGROUND

Spinal muscular atrophy (SMA) is a rare neurodegenerative disease characterized by progressive muscular weakness, which occurs in one in 6,000 to 10,000 live births. The burden of SMA on Canadian patients and caregivers is not known.

OBJECTIVE

To characterize the burden of SMA in Canada as reported by patients and caregivers, including disease and treatment impacts, indirect costs, and caregiver burden.

METHODS

Surveys were distributed by Cure SMA Canada and Muscular Dystrophy Canada to individuals with SMA and their caregivers. The online surveys were anonymous and completed between January 28 and February 21, 2020.

RESULTS

965 patient and 962 caregiver responses met the eligibility criteria. Patients reported SMA subtypes as: type I (25.0%), type II (41.3%), type III (29.3%). Using the EQ-5D, patients were shown to have impaired quality of life with an average health utility index of 0.49 (SD: 0.26). The median expenditure was $4,500 CAD (IQR: $1,587 - $11,000) for assistive devices; $6,800 CAD (IQR: $3,900-$13,000) on health professional services; and $1,200 CAD (IQR: $600 -$3,100) on SMA-related travel and accommodation in the past 12 months. Caregivers reported needing respite care (45.7%), physiotherapy for an injury from a lift/transfer (45.7%), or other health impacts (63.3%). Caregivers reported changes to personal plans, sleep disturbances, and work adjustments, with a mean Caregiver Strain Index score of 7.5 [SD: 3.3].

CONCLUSION

SMA in Canada is associated with a significant burden for patients and their caregivers.

PI by NMR: Probing CH-π Interactions in Protein-Ligand Complexes by NMR Spectroscopy

While CH–π interactions with target proteins are crucial determinants for the affinity of arguably every drug molecule, no method exists to directly measure the strength of individual CH–π interactions in drug–protein complexes. Herein, we present a fast and reliable methodology called PI (π interactions) by NMR, which can differentiate the strength of protein–ligand CH–π interactions in solution. By combining selective amino‐acid side‐chain labeling with ¹H‐¹³C NMR, we are able to identify specific protein protons of side‐chains engaged in CH–π interactions with aromatic ring systems of a ligand, based solely on ¹H chemical‐shift values of the interacting protein aromatic ring protons. The information encoded in the chemical shifts induced by such interactions serves as a proxy for the strength of each individual CH–π interaction. PI by NMR changes the paradigm by which chemists can optimize the potency of drug candidates: direct determination of individual π interactions rather than averaged measures of all interactions.

Fear the reaper: ungulate carcasses may generate an ephemeral landscape of fear for rodents

Animal carcasses provide an ephemeral pulse of nutrients for scavengers that use them. Carcass sites can increase species interactions and/or ephemeral, localized landscapes of fear for prey within the vicinity. Few studies have applied the landscape of fear to carcasses. Here, we use a mass die-off of reindeer caused by lightning in Norway to test whether rodents avoided larger scavengers (e.g. corvids and fox). We used the presence and abundance of faeces as a proxy for carcass use over the course of 2 years and found that rodents showed the strongest avoidance towards changes in raven abundance (β = -0.469, s.e. = 0.231, p-value = 0.0429), but not fox, presumably due to greater predation risk imposed by large droves of raven. Moreover, the emergence of rodent occurrence within the carcass area corresponded well with the disappearance of raven during the second year of the study. We suggest that carcasses have the potential to shape the landscape of fear for prey, but that the overall effects of carcasses on individual fitness and populations of species ultimately depend on the carcass regime, e.g. carcass size, count, and areal extent, frequency and the scavenger guild. We discuss conservation implications and how carcass provisioning and landscapes of fear could be potentially used to manage populations and ecosystems, but that there is a gap in understanding that must first be bridged.

Start Selective and Rigidify: The Discovery Path toward a Next Generation of EGFR Tyrosine Kinase Inhibitors

The epidermal growth factor receptor (EGFR), when carrying an activating mutation like del19 or L858R, acts as an oncogenic driver in a subset of lung tumors. While tumor responses to tyrosine kinase inhibitors (TKIs) are accompanied by marked tumor shrinkage, the response is usually not durable. Most patients relapse within two years of therapy often due to acquisition of an additional mutation in EGFR kinase domain that confers resistance to TKIs. Crucially, oncogenic EGFR harboring both resistance mutations, T790M and C797S, can no longer be inhibited by currently approved EGFR TKIs. Here, we describe the discovery of BI-4020, which is a noncovalent, wild-type EGFR sparing, macrocyclic TKI. BI-4020 potently inhibits the above-described EGFR variants and induces tumor regressions in a cross-resistant EGFR^{del19 T790M C797S} xenograft model. Key was the identification of a highly selective but moderately potent benzimidazole followed by complete rigidification of the molecule through macrocyclization.

Drugging an undruggable pocket on KRAS

The 3 human RAS genes, KRAS, NRAS, and HRAS, encode 4 different RAS proteins which belong to the protein family of small GTPases that function as binary molecular switches involved in cell signaling. Activating mutations in RAS are among the most common oncogenic drivers in human cancers, with KRAS being the most frequently mutated oncogene. Although KRAS is an excellent drug discovery target for many cancers, and despite decades of research, no therapeutic agent directly targeting RAS has been clinically approved. Using structure-based drug design, we have discovered BI-2852 (1), a KRAS inhibitor that binds with nanomolar affinity to a pocket, thus far perceived to be "undruggable," between switch I and II on RAS; 1 is mechanistically distinct from covalent KRASG12C inhibitors because it binds to a different pocket present in both the active and inactive forms of KRAS. In doing so, it blocks all GEF, GAP, and effector interactions with KRAS, leading to inhibition of downstream signaling and an antiproliferative effect in the low micromolar range in KRAS mutant cells. These findings clearly demonstrate that this so-called switch I/II pocket is indeed druggable and provide the scientific community with a chemical probe that simultaneously targets the active and inactive forms of KRAS.

KRAS Binders Hidden in Nature

Natural products have proven to be a rich source of molecular architectures for drugs. Here, an integrated approach to natural product screening is proposed, which uncovered eight new natural product scaffolds for KRAS-the most frequently mutated oncogenic driver in human cancers, which has remained thus far undrugged. The approach combines aspects of virtual screening, fragment-based screening, structure-activity relationships (SAR) by NMR, and structure-based drug discovery to overcome the limitations in traditional natural product approaches. By using our approach, a new "snugness of fit" scoring function and the first crystal-soaking system of the active form of KRAS^G12D , the protein-ligand X-ray structures of a tricyclic indolopyrrole fungal alkaloid and an indoloisoquinolinone have been successfully elucidated. The natural product KRAS hits discovered provide fruitful ground for the optimization of highly potent natural-product-based inhibitors of the active form of oncogenic RAS. This integrated approach for screening natural products also holds promise for other "undruggable" targets.

Exploring the Structure of the Bound Proton with Deeply Virtual Compton Scattering

In the past two decades, deeply virtual Compton scattering of electrons has been successfully used to advance our knowledge of the partonic structure of the free proton and investigate correlations between the transverse position and the longitudinal momentum of quarks inside the nucleon. Meanwhile, the structure of bound nucleons in nuclei has been studied in inclusive deep-inelastic lepton scattering experiments off nuclear targets, showing a significant difference in longitudinal momentum distribution of quarks inside the bound nucleon, known as the EMC effect. In this Letter, we report the first beam spin asymmetry (BSA) measurement of exclusive deeply virtual Compton scattering off a proton bound in ^{4}He. The data used here were accumulated using a 6 GeV longitudinally polarized electron beam incident on a pressurized ^{4}He gaseous target placed within the CLAS spectrometer in Hall-B at the Thomas Jefferson National Accelerator Facility. The azimuthal angle (ϕ) dependence of the BSA was studied in a wide range of virtual photon and scattered proton kinematics. The Q^{2}, x_{B}, and t dependencies of the BSA on the bound proton are compared with those on the free proton. In the whole kinematical region of our measurements, the BSA on the bound proton is smaller by 20% to 40%, indicating possible medium modification of its partonic structure.

Patient satisfaction with correction of congenital penile curvature

BACKGROUND

Congenital penile curvature is a relatively rare disease, resulting from a deviation of the penis from the body's straight axis when erect. The prevalence is difficult to determine. Although it has been suggested that the condition could affect up to 10% of the male population, most of these deviations are minor, with no clinical or psychological importance, which leads to its underdiagnosis. Effective correction of the deviation can markedly improve the quality of life of adolescents with this condition.

OBJECTIVE

To assess the quality of the sex life of patients diagnosed with congenital penile curvature who underwent surgical correction.

MATERIALS AND METHODS

Design Retrospective, observational cohort study. Data was collected from the medical records of patients who underwent surgical correction of congenital penile curvature from June 2004 to August 2016. The patients completed the following self-administered questionnaires: Sexual Quality of Life Questionnaire-Male (SQOL-M), International Index of Erectile Function 5 (IIEF 5) and "How satisfied are you with the results of the surgery? From 0 to 10".

RESULTS

Twenty-two corporoplasties were performed to correct the patients' congenital penile curvature. The patients' average age was 23.4 years (range, 17-35). The mean deviation prior to surgery was 47.9° (range, 20°-90°). The average score on the SQOL-M was 52 points (range, 6-66). The average score on the IIEF 5 was 22.4 points.

CONCLUSION

Congenital penile curvature profoundly decreases quality of life, and early surgery is fundamental for repairing the anatomical deformation and thereby significantly restores the patients' psychosocial and sexual wellbeing.