Caging of a widely used Von Hippel Lindau E3 ligase ligand for targeted protein degradation with PROTACs allows light-activated proteolysis.

Background The etiological basis of glioma is poorly understood. We have used genetic markers in a Mendelian Randomisation (MR) framework to examine if lifestyle, cardiometabolic and inflammatory factors influence the risk of glioma. This methodology reduces bias from confounding and is not affected by reverse causation. Methods We identified genetic instruments for 37 potentially modifiable risk factors and evaluated their association with glioma risk using data from a genome-wide association study of 12,488 glioma patients and 18,169 controls. We used the estimated odds ratio of glioma associated with each of the genetically defined traits to infer evidence for a causal relationship with the following exposures: lifestyle and dietary factors (height, plasma IGF-1, blood carnitine, blood methionine, blood selenium, blood zinc, circulating adiponectin, circulating carotenoids, iron status, serum calcium, vitamin [A1, B12, B6, E and 25-hydroxyvitamin D], fatty acids levels [mono-unsaturated, omega-3 and omega-6] and circulating fetuin-A); cardiometabolic factors (birth weight, HDL cholesterol, LDL cholesterol, total cholesterol, total triglycerides, basal metabolic rate, body fat percentage, body mass index, fasting glucose, fasting proinsulin, HbA1C levels, diastolic and systolic blood pressure, waist circumference, waist-to-hip ratio) were included; inflammatory factors (C-reactive protein (CRP), plasma IL-6 sRa and serum IgE). Results After correction for the testing of multiple potential risk factors and excluding associations driven by one single nucleotide polymorphism (SNP) no significant association with glioma risk was observed (i.e. PCorrected > 0.05). Conclusions This study did not provide evidence supporting any of the 37 factors examined as having a significant influence on glioma risk.

Background Telomere maintenance is increasingly recognised as being fundamental to glioma oncogenesis with longer leucocyte telomere length (LTL) reported to increase risk of glioma. To gain further insight into the relationship between telomere genetics and risk of glioma we conducted several complementary analyses, using GWAS data on LTL (78,592 individuals) and glioma (12,488 cases and 18,169 controls). Methods We performed both classical and Summary Mendelian Randomization (SMR), coupled with heterogeneity in dependent instruments tests, at genome-wide significant LTL loci to examine if an association was mediated by the same causal variant in glioma. To prioritize genes underscoring glioma-LTL associations we analysed gene expression and DNA methylation data. Results Genetically increased LTL was significantly associated with increased glioma risk, IVW-RE ORSD 4.79 (95% CI: 2.11-10.85, P = 1.76 × 10 -4). SMR confirmed the previously reported LTL associations at 3q26.2 (TERC; PSMR = 1.33 × 10 -5), 5p15.33 (TERT; PSMR = 9.80 × 10 -27), 10q24.33 (STN1 alias OBFC1; PSMR = 4.31 × 10 -5) and 20q13.3 (STMN3/RTEL1; PSMR = 2.47 × 10 -4) glioma risk loci. Our analysis implicates variation at 1q42.12 (PSMR = 1.55 × 10 -2), 6p21.3 (PSMR = 9.76 × 10 -3), 6p22.2 (PSMR = 5.45 × 10 -3), 7q31.33 (PSMR = 6.52 × 10 -3) and 11q22.3 (PSMR = 8.89 × 10 -4) as risk factors for glioma risk. Whilst complicated by patterns of linkage disequilibrium, genetic variation involving PARP1, PRRC2A, CARMIL1, POT1 and ATM-NPAT1 was implicated in the aetiology of glioma. Conclusions These observations extend the role of telomere-related genes in the development of glioma.

Inhibition of the poly­(ADP-ribose) polymerase (PARP) family of enzymes has become an attractive therapeutic strategy in oncology and beyond; however, chemical tools to profile PARP engagement in live cells are lacking. Herein, we report the design and application of PARPYnD, the first photoaffinity probe (AfBP) for PARP enzymes based on triple PARP1/2/6 inhibitor AZ9482, which induces multipolar spindle (MPS) formation in breast cancer cells. PARPYnD is a robust tool for profiling PARP1/2 and is used to profile clinical PARP inhibitor olaparib, identifying several novel off-target proteins. Surprisingly, while PARPYnD can enrich recombinant PARP6 spiked into cellular lysates and inhibits PARP6 in cell-free assays, it does not label PARP6 in intact cells. These data highlight an intriguing biomolecular disparity between recombinant and endogenous PARP6. PARPYnD provides a new approach to expand our knowledge of the targets of this class of compounds and the mechanisms of action of PARP inhibitors in cancer.

Malaria is still a leading cause of mortality among children in the developing world, and despite the immense progress made in reducing the global burden, further efforts are needed if eradication is to be achieved. In this context, targeting transmission is widely recognized as a necessary intervention towards that goal. After carrying out a screen to discover new transmission-blocking agents, herein we report our medicinal chemistry efforts to study the potential of the most robust hit, DDD01035881, as a male-gamete targeted compound. We reveal key structural features for the activity of this series and identify analogues with greater potency and improved metabolic 2 stability. We believe this study lays the groundwork for further development of this series as a transmission blocking agent. 3 130±30 6 128±10 34 > 1000 35 785±48 36 > 25000 37 > 10000 38 196±19 39 83±13 40 364±47 41 79±18 42 > 25000 43 > 25000 44 > 25000 45 > 25000 a Biological evaluation was carried out using the DGFA under the specific "add-in" format. Compounds were incubated at variable concentrations with fresh gametocytes, and their ability to impair exflagellation of male gametes determined. Values below 1 µM are expressed as the mean±SEM obtained from between three and eight biological replicates, each carried out in at least duplicate. All synthesised analogues resulted in a significant loss of activity, with the exception of fluorinated derivatives 38-41 (Table 2). Compounds 39 and 41 even show a slight improvement in potency over 6. Once again, these results suggest the binding site of this series within the target(s) to be reasonably confined. Indeed, in contrast to other substituents, fluorine is very similar in size to hydrogen, which could explain why analogues 38-41 retain activity. It should be highlighted that fluorine is widely used within drug discovery to improve permeability by increasing lipophilicity and to address pharmacokinetic issues such as oxidative metabolism, 21 the latter being interesting in the context of this work (vide infra).

Background Renal cell carcinoma (RCC) occurs in a number of cancer predisposition syndromes but the genetic architecture of susceptibility to RCC is not well defined. We investigated the frequency of pathogenic germline variants in cancer susceptibility genes (CSGs) within a large series of unselected RCC participants. Methods Whole genome sequencing data on 1336 RCC participants and 5834 controls recruited to the UK 100000 Genomes Project, a nationwide multicentre study, was analysed to identify rare pathogenic or likely pathogenic (P/LP) short variants (SNVs and INDELs) and structural variants in 121 CSGs. Results Among 1336 RCC participants (mean 61.3 years [±12SD], range 13–88 years; 64% male), 85 participants (6.4%; 95% CI [5.1, 7.8]) had one or more P/LP germline variant in a wider range of CSGs than previously recognised. A further 64 intragenic variants in CSGs previously associated with RCC were classified as a variant of uncertain significance (VUS) (24 ‘hot VUSs’) and were considered to be of potential clinical relevance as further evaluation might result in their reclassification. Most patients with pathogenic variants in well-established RCC-CSGs were aged < 50 years. Burden test analysis for filtered variants in CSGs demonstrated a significant excess of CHEK2 variants RCC European participants compared to the healthy European controls (P = 0.0019). Conclusions Approximately 6% of patients with RCC unselected for family history have a germline variant requiring additional follow-up analysis. To improve diagnostic yield we suggest expanding the panel of RCC-CSGs tested to include CHEK2 and all SDHx subunits and raising the eligibility criteria for age-based testing.

Background The aetiology of glioma is poorly understood. Summary data from genome-wide association studies (GWAS) can be used in a Mendelian randomisation (MR) phenome-wide association study (PheWAS) to search for glioma risk factors. Methods We performed an MR-PheWAS analysing 316 phenotypes, proxied by 8387 genetic variants, and summary genetic data from a GWAS of 12,488 glioma cases and 18,169 controls. Causal effects were estimated under a random-effects inverse-variance-weighted (IVW-RE) model, with robust adjusted profile score (MR-RAPS), weighted median and mode-based estimates computed to assess the robustness of findings. Odds ratios per one standard deviation increase in each phenotype were calculated for all glioma, glioblastoma (GBM) and non-GBM tumours. Results No significant associations (P < 1.58 × 10−4) were observed between phenotypes and glioma under the IVW-RE model. Suggestive associations (1.58 × 10−4 < P < 0.05) were observed between leukocyte telomere length (LTL) with all glioma (ORSD = 3.91, P = 9.24 × 10−3) and GBM (ORSD = 4.86, P = 3.23 × 10−2), but the association was primarily driven by the TERT variant rs2736100. Serum low-density lipoprotein cholesterol and plasma HbA1C showed suggestive associations with glioma (ORSD = 1.11, P = 1.39 × 10−2 and ORSD = 1.28, P = 1.73 × 10−2, respectively), both associations being reliant on single genetic variants. Conclusions Our study provides further insight into the aetiological basis of glioma for which published data have been mixed.

Phenotypic cell-based screens are critical tools for discovering candidate drugs for development, yet identification of the cellular target and mode of action of a candidate drug is often lacking. Using an imaging-based screen, we recently discovered an N-[(4-hydroxychroman-4-yl)methyl]-sulphonamide (N-4HCS) compound, DDD01035881, that blocks male gamete formation in the malaria parasite life cycle and subsequent transmission of the parasite to the mosquito with nanomolar activity. To identify the target(s) of DDD01035881, and of the N-4HCS class of compounds more broadly, we synthesised a photoactivatable derivative, probe 2. Photoaffinity labelling of probe 2 coupled with mass spectrometry identified the 16 kDa Plasmodium falciparum parasitophorous vacuole membrane protein Pfs16 as a potential parasite target. Complementary methods including cellular thermal shift assays confirmed that the parent molecule DDD01035881 stabilised Pfs16 in lysates from activated mature gametocytes. Combined with high-resolution, fluorescence and electron microscopy data, which demonstrated that parasites inhibited with N-4HCS compounds phenocopy the targeted deletion of Pfs16 in gametocytes, these data implicate Pfs16 as a likely target of DDD01035881. This finding establishes N-4HCS compounds as being flexible and effective starting candidates from which transmission-blocking antimalarials can be developed in the future.