Enhancing the Small-Scale Screenable Biological Space beyond Known Chemogenomics Libraries with Gray Chemical Matter─Compounds with Novel Mechanisms from High-Throughput Screening Profiles

Phenotypic assays have become an established approach to drug discovery. Greater disease relevance is often achieved through cellular models with increased complexity and more detailed readouts, such as gene expression or advanced imaging. However, the intricate nature and cost of these assays impose limitations on their screening capacity, often restricting screens to well-characterized small compound sets such as chemogenomics libraries. Here, we outline a cheminformatics approach to identify a small set of compounds with likely novel mechanisms of action (MoAs), expanding the MoA search space for throughput limited phenotypic assays. Our approach is based on mining existing large-scale, phenotypic high-throughput screening (HTS) data. It enables the identification of chemotypes that exhibit selectivity across multiple cell-based assays, which are characterized by persistent and broad structure activity relationships (SAR). We validate the effectiveness of our approach in broad cellular profiling assays (Cell Painting, DRUG-seq, and Promotor Signature Profiling) and chemical proteomics experiments. These experiments revealed that the compounds behave similarly to known chemogenetic libraries, but with a notable bias toward novel protein targets. To foster collaboration and advance research in this area, we have curated a public set of such compounds based on the PubChem BioAssay dataset and made it available for use by the scientific community.

TROPHY-U-01, a phase II open-label study of sacituzumab govitecan in patients with metastatic urothelial carcinoma progressing after platinum-based chemotherapy and checkpoint inhibitors: updated safety and efficacy outcomes

BACKGROUND

Sacituzumab govitecan (SG) is a Trop-2-directed antibody-drug conjugate containing cytotoxic SN-38, the active metabolite of irinotecan. SG received accelerated US Food and Drug Administration approval for locally advanced (LA) or metastatic urothelial carcinoma (mUC) previously treated with platinum-based chemotherapy and a checkpoint inhibitor, based on cohort 1 of the TROPHY-U-01 study. Mutations in the uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) gene are associated with increased adverse events (AEs) with irinotecan-based therapies. Whether UGT1A1 status could impact SG toxicity and efficacy remains unclear.

PATIENTS AND METHODS

TROPHY-U-01 (NCT03547973) is a multicohort, open-label, phase II registrational study. Cohort 1 includes patients with LA or mUC who progressed after platinum- and checkpoint inhibitor-based therapies. SG was administered at 10 mg/kg intravenously on days 1 and 8 of 21-day cycles. The primary endpoint was objective response rate (ORR) per central review; secondary endpoints included progression-free survival, overall survival, and safety. Post hoc safety analyses were exploratory with descriptive statistics. Updated analyses include longer follow-up.

RESULTS

Cohort 1 included 113 patients. At a median follow-up of 10.5 months, ORR was 28% (95% CI 20.2% to 37.6%). Median progression-free survival and overall survival were 5.4 months (95% CI 3.5-6.9 months) and 10.9 months (95% CI 8.9-13.8 months), respectively. Occurrence of grade ≥3 treatment-related AEs and treatment-related discontinuation were consistent with prior reports. UGT1A1 status was wildtype (∗1|∗1) in 40%, heterozygous (∗1|∗28) in 42%, homozygous (∗28|∗28) in 12%, and missing in 6% of patients. In patients with ∗1|∗1, ∗1|∗28, and ∗28|∗28 genotypes, any grade treatment-related AEs occurred in 93%, 94%, and 100% of patients, respectively, and were managed similarly regardless of UGT1A1 status.

CONCLUSIONS

With longer follow-up, the ORR remains high in patients with heavily pretreated LA or mUC. Safety data were consistent with the known SG toxicity profile. AE incidence varied across UGT1A1 subgroups; however, discontinuation rates remained relatively low for all groups.

Activation of human STING by a molecular glue-like compound

Stimulator of interferon genes (STING) is a dimeric transmembrane adapter protein that plays a key role in the human innate immune response to infection and has been therapeutically exploited for its antitumor activity. The activation of STING requires its high-order oligomerization, which could be induced by binding of the endogenous ligand, cGAMP, to the cytosolic ligand-binding domain. Here we report the discovery through functional screens of a class of compounds, named NVS-STGs, that activate human STING. Our cryo-EM structures show that NVS-STG2 induces the high-order oligomerization of human STING by binding to a pocket between the transmembrane domains of the neighboring STING dimers, effectively acting as a molecular glue. Our functional assays showed that NVS-STG2 could elicit potent STING-mediated immune responses in cells and antitumor activities in animal models.

Discovery and Structure-Based Design of Inhibitors of the WD Repeat-Containing Protein 5 (WDR5)-MYC Interaction

WDR5 is a critical chromatin cofactor of MYC. WDR5 interacts with MYC through the WBM pocket and is hypothesized to anchor MYC to chromatin through its WIN site. Blocking the interaction of WDR5 and MYC impairs the recruitment of MYC to its target genes and disrupts the oncogenic function of MYC in cancer development, thus providing a promising strategy for the treatment of MYC-dysregulated cancers. Here, we describe the discovery of novel WDR5 WBM pocket antagonists containing a 1-phenyl dihydropyridazinone 3-carboxamide core that was identified from high-throughput screening and subsequent structure-based design. The leading compounds showed sub-micromolar inhibition in the biochemical assay. Among them, compound 12 can disrupt WDR5-MYC interaction in cells and reduce MYC target gene expression. Our work provides useful probes to study WDR5-MYC interaction and its function in cancers, which can also be used as the starting point for further optimization toward drug-like small molecules.

Mechanism of Resistance to the WDR5 Inhibitor in MLL-Rearranged Leukemia

Drug resistance is a major problem often limiting the long-term effectiveness of targeted cancer therapeutics. Resistance can be acquired through mutations or amplification of the primary drug targets or activation of bypass signaling pathways. Considering the multifaceted function of WDR5 in human malignancies, WDR5 has emerged as an attractive drug target for the discovery of small-molecule inhibitors. In this study, we investigated if cancer cells might develop resistance to a highly potent WDR5 inhibitor. We established a drug-adapted cancer cell line and discovered that WDR5^P173L mutation occurs in the resistant cells, which confers resistance by preventing target engagement of the inhibitor. This work elucidated the WDR5 inhibitor's potential resistance mechanism in a preclinical study as a reference for future study in the clinical stage.

Discovery and characterization of a selective IKZF2 glue degrader for cancer immunotherapy

Malignant tumors can evade destruction by the immune system by attracting immune-suppressive regulatory T cells (Treg) cells. The IKZF2 (Helios) transcription factor plays a crucial role in maintaining function and stability of Treg cells, and IKZF2 deficiency reduces tumor growth in mice. Here we report the discovery of NVP-DKY709, a selective molecular glue degrader of IKZF2 that spares IKZF1/3. We describe the recruitment-guided medicinal chemistry campaign leading to NVP-DKY709 that redirected the degradation selectivity of cereblon (CRBN) binders from IKZF1 toward IKZF2. Selectivity of NVP-DKY709 for IKZF2 was rationalized by analyzing the DDB1:CRBN:NVP-DKY709:IKZF2(ZF2 or ZF2-3) ternary complex X-ray structures. Exposure to NVP-DKY709 reduced the suppressive activity of human Treg cells and rescued cytokine production in exhausted T-effector cells. In vivo, treatment with NVP-DKY709 delayed tumor growth in mice with a humanized immune system and enhanced immunization responses in cynomolgus monkeys. NVP-DKY709 is being investigated in the clinic as an immune-enhancing agent for cancer immunotherapy.

Discovery of Potent Small-Molecule Inhibitors of WDR5-MYC Interaction

WD repeat domain 5 (WDR5) is a member of the WD40-repeat protein family that plays a critical role in multiple processes. It is also a prominent target for pharmacological inhibition in diseases such as cancer, aging, and neurodegenerative disorders. Interactions between WDR5 and various partners are essential for sustaining its function. Most drug discovery efforts center on the WIN (WDR5 interaction motif) site of WDR5 that is responsible for the recruitment of WDR5 to chromatin. Here, we describe the discovery of novel WDR5 inhibitors for the other WBM (WDR5 binding motif) pocket on this scaffold protein, to disrupt WDR5 interaction with its binding partner MYC by high-throughput biochemical screening, subsequent molecule optimization, and biological assessment. These new WDR5 inhibitors provide useful probes for future investigations of WDR5 and an avenue for targeting WDR5 as a therapeutic strategy.

1022 Early Cholecystectomy in the Ageing Population

Background

The age group of patients presenting acutely with biliary pathology is rising and gallstone disease can no longer be said to be a disease of the young. The World Health Organisation classifies those aged 65 and over as elderly. Early cholecystectomy is accepted as a safe and effective method of managing acute biliary pathology, reducing further admissions, and reducing in-hospital stays. Our unit does not use age as barrier but uses performance status and co-morbidity to identify potential candidates for cholecystectomy.

Method

Patients over the age of 65 who underwent acute cholecystectomy (AC) via the emergency cholecystectomy lists, were audited from 31st December 2019 to 31st June 2021. Patient demographics, co-morbidities and surgical factors were recorded. The primary outcome measures were in-hospital stay and re-admission, secondary outcomes were complications and perioperative mortality.

Results

41 elderly patients underwent AC during the audit period, (Female 56%, Male 44%). 30 patients had acute cholecystitis (73%). The median inpatient stay following surgery was 2 days (range 2–5 days) and the median admission to surgery time was 6 days (range 5–12 days). Three patients had a subtotal cholecystectomy. There were 3 complications from surgery which were all between a Clavien-Dindo score of 2 and 3. There were 3 immediate post-operative readmissions, with one 30-day mortality from ERCP pancreatitis and not from the operation.

Conclusion

Early cholecystectomy appears to be a safe and effective treatment for this group of patients and based on this evidence we should continue to offer this treatment to patients irrespective of age.

Phenotypic screen identifies calcineurin-sparing FK506 analogs as BMP potentiators for treatment of acute kidney injury

Acute kidney injury (AKI) is a life-threatening disease with no known curative or preventive therapies. Data from multiple animal models and human studies have linked dysregulation of bone morphogenetic protein (BMP) signaling to AKI. Small molecules that potentiate endogenous BMP signaling should have a beneficial effect in AKI. We performed a high-throughput phenotypic screen and identified a series of FK506 analogs that act as potent BMP potentiators by sequestering FKBP12 from BMP type I receptors. We further showed that calcineurin inhibition was not required for this activity. We identified a calcineurin-sparing FK506 analog oxtFK through late-stage functionalization and structure-guided design. OxtFK demonstrated an improved safety profile in vivo relative to FK506. OxtFK stimulated BMP signaling in vitro and in vivo and protected the kidneys in an AKI mouse model, making it a promising candidate for future development as a first-in-class therapeutic for diseases with dysregulated BMP signaling.

Using opportunistic screening with abdominal CT to identify osteoporosis and osteopenia in patients with diabetes

Opportunistic osteoporosis screening involves measuring the attenuation of L1 vertebrae on abdominal computed tomography (CT), which correlates with DXA T-score. We found that this approach is useful for detecting low bone mass in patients with diabetes and propose L1 attenuation ≤ 135 Hounsfield units (HU) as a threshold for which DXA should be strongly considered.

INTRODUCTION

Attenuation of the L1 vertebrae on computer tomography (CT) images done for other reasons ("Opportunistic Osteoporosis Screening") has been found to correlate well with DXA-derived T-score. However, the method and the thresholds have never been tested specifically in those with diabetes mellitus (DM), in whom the fracture risk is greater than explained by BMD.

METHODS

In a retrospective study of subjects with DM who had both abdominal CT and DXA within 6 months of each other, we compared L1 attenuation and DXA T-score to define the sensitivity and specificity of thresholds previously established in the general population.

RESULTS

There were 313 subjects among whom 18 (5.8%) had prior major osteoporotic fracture (MOF). Subjects with MOF had lower T-scores (- 2.3 ± 1.4 vs. - 0.9 ± 1.4, p < 0.001) and L1 attenuation (104 HU ± 46 vs. 149 HU ± 47, p < 0.001) than non-fracture subjects. L1 attenuation ≤ 160 HU was 91% sensitive for osteoporosis, while ≤ 110 HU was 80% specific. For a higher T-score of ≤ - 1.5, L1 attenuation ≤ 135 HU showed balanced sensitivity and specificity (65% and 69%, respectively).

CONCLUSION

Opportunistic osteoporosis screening with abdominal CT is useful in determining the need for DXA screening in subjects with diabetes. We propose L1 attenuation ≤ 135 HU as a reasonable threshold for detecting the T-score of ≤ - 1.5, which is likely associated with increased fragility in DM.

Fiber-based sources of coherent MIR radiation: key advances and future prospects (invited)

The mid-infrared (MIR) represents a large portion of the electromagnetic spectrum that is progressively being exploited for an enormous number of applications. Thermal imaging cameras, dental and skin resurfacing lasers, and narcotics detectors at airports are all mainstream examples involving the MIR, but potential applications of MIR technologies are much larger. Accessing the unique opportunities afforded by the MIR is critically dependent on the specific characteristics of MIR emitting sources that become available. In this review, we survey an important enabling technology to the opening up of MIR science and applications, namely that driven by fiber-based sources of coherent MIR radiation. In this review paper, we describe many of the key advances in the innovation and development of such sources over the past few decades and discuss many of the underlying science and technology issues that have resulted in specific recent source achievements, especially in light of new applications enabled by these new source capabilities. We also discuss a few specific anticipated future needs and some potentially disruptive approaches to future MIR fiber source development.

Spectral trimming technique: a new approach for suppressing motion artefacts in stress electrocardiography

Motion artefacts in electrocardiographic (ECG) signal are suppressed mainly by adaptive noise cancellation and wavelet denoising. While the former requires a motion sensor in addition to ECG electrodes, the latter removes some of the desired low-frequency components in the signal. In this paper spectral trimming technique is being introduced for suppressing the motion artefacts in stress electrocardiography. In this method, Fourier spectral coefficients up to 1.221 Hz of noisy signal are trimmed on the basis of template derived from resting ECG signal in the same subject. The proposed spectral trimming technique has yielded the lowest value of mean ± standard deviation for root mean square error (18.92 ± 8.71) and highest value of the signal to noise ratio (6.439 ± 4.266) as compared to other three methods, namely adaptive noise cancellation, wavelet decomposition and adaptive line enhancement with compatible value of correlation coefficient. Subsequently, spectral trimming technique has been implemented in real-time (deferred by 8.2 s) application for stress electrocardiography. Spectral trimming technique thus offers a method of choice for motion artefact suppression in offline as well as deferred online applications. This method takes care of the limitations of conventional methods such as adaptive noise cancellation or wavelet denoising for suppressing motion artefacts in stress electrocardiography.

Systematic Chemogenetic Library Assembly

Chemogenetic libraries, collections of well-defined chemical probes, provide tremendous value to biomedical research but require substantial effort to ensure diversity as well as quality of the contents. We have assembled a chemogenetic library by data mining and crowdsourcing institutional expertise. We are sharing our approach, lessons learned, and disclosing our current collection of 4,185 compounds with their primary annotated gene targets (https://github.com/Novartis/MoaBox). This physical collection is regularly updated and used broadly both within Novartis and in collaboration with external partners.

Luminescent ion-doped transparent glass ceramics for mid-infrared light sources [invited]

Glass ceramics (GCs), which consist essentially of a homogeneous solid state dispersion of nanocrystals (NCs) embedded in a chemically inert and mechanically robust glass matrix, appear to be an extremely promising class of solid state materials that can be easily tailored into arbitrary shapes, including a new generation of optical fibers, for efficient incoherent and coherent sources of mid-infrared (MIR) light emission. This unique capability not only stems from the fact that one can tailor the underlying glass matrix for optimal macroscopic physical properties and ultrahigh transparency at the wavelengths of interest (resulting in appropriate "transparent glass ceramics" or TGCs), but also stems from the fact that one can embed these matrices with size and structure-tailored NCs, which in turn can be doped with relatively high concentrations of MIR emitting rare-earth or transition metal ions. This potential is tantamount to the localization of these highly efficient MIR ionic emitters into carefully selected and highly favorable "process-engineered" custom crystalline host "nanocages," while insulating the ionic emitters from the emission-quenching glass host matrix, the latter being chosen largely because of its highly favorable macroscopic bulk properties, including its ductility and formability into near-arbitrary shapes (at appropriate temperatures). Such MIR TGCs appear to be very promising for numerous photonics applications, including compact and relatively efficient waveguide sensors, broadband incoherent MIR light sources, superluminescent light sources, advanced fiber-optic devices, and broadly wavelength-tunable and ultrashort pulse mode-locked fiber and bulk solid-state lasers. In this paper, we review past achievements in this field, starting with an overview of TGCs, followed by discussions of currently preferred methods of fabrication, characterization, and optimization of suitably doped oxyfluoride, tellurite, and chalcogenide TGCs and of our projections of anticipated future developments in this field at both the materials and device levels.

Seed transmission of a distinct soybean yellow mottle mosaic virus strain identified from India in natural and experimental hosts

Soybean yellow mottle mosaic virus (SYMMV) is a newly identified member of the genus Gammacarmovirus from grain legumes in India. As the modes of transmission of this virus have not been described, we assessed the possibility of SYMMV to be transmitted through seed collected from field infected mungbean plants and mechanically sap inoculated French bean plants using serological and molecular techniques followed by progeny assays. Direct antigen coated enzyme linked immunosorbent assay (DAC-ELISA) and reverse transcription polymerase chain reaction (RT-PCR) results are inconsistent with field infected mungbean seed tissues to ensure seed transmissibility irrespective of seed number used. Seed from mechanical sap inoculated French bean showed higher absorbance values in DAC-ELISA and amplification corresponding to replicase, movement and coat protein regions of SYMMV genome. The relative accumulation of SYMMV was higher in pod walls, immature seed and stamens and stigma of mechanical sap inoculated French bean. Progeny assays with infected seed revealed the seed transmissibility of SYMMV at the rate of 63.33% in mungbeanand 73.33% in French bean. Mechanical sap inoculation of mungbean progeny seedlings on French bean cv. Pusa Parvati produced characteristic symptoms of SYMMV. The results obtained from this study demonstrate that SYMMV is seed borne in nature and can be transmitted to next generation seedlings. This is the first report of seed transmission of SYMMV in mungbean and French bean.

Previously Uncharacterized Vacuolar-type ATPase Binding Site Discovered from Structurally Similar Compounds with Distinct Mechanisms of Action

Using a comprehensive chemical genetics approach, we identified a member of the lignan natural product family, HTP-013, which exhibited significant cytotoxicity across various cancer cell lines. Correlation of compound activity across a panel of reporter gene assays suggested the vacuolar-type ATPase (v-ATPase) as a potential target for this compound. Additional cellular studies and a yeast haploinsufficiency screen strongly supported this finding. Competitive photoaffinity labeling experiments demonstrated that the ATP6V0A2 subunit of the v-ATPase complex binds directly to HTP-013, and further mutagenesis library screening identified resistance-conferring mutations in ATP6V0A2. The positions of these mutations suggest the molecule binds a novel pocket within the domain of the v-ATPase complex responsible for proton translocation. While other mechanisms of v-ATPase regulation have been described, such as dissociation of the complex or inhibition by natural products including bafilomycin A1 and concanamycin, this work provides detailed insight into a distinct binding pocket within the v-ATPase complex.

Discovery of a ZIP7 inhibitor from a Notch pathway screen

The identification of activating mutations in NOTCH1 in 50% of T cell acute lymphoblastic leukemia has generated interest in elucidating how these mutations contribute to oncogenic transformation and in targeting the pathway. A phenotypic screen identified compounds that interfere with trafficking of Notch and induce apoptosis via an endoplasmic reticulum (ER) stress mechanism. Target identification approaches revealed a role for SLC39A7 (ZIP7), a zinc transport family member, in governing Notch trafficking and signaling. Generation and sequencing of a compound-resistant cell line identified a V430E mutation in ZIP7 that confers transferable resistance to the compound NVS-ZP7-4. NVS-ZP7-4 altered zinc in the ER, and an analog of the compound photoaffinity labeled ZIP7 in cells, suggesting a direct interaction between the compound and ZIP7. NVS-ZP7-4 is the first reported chemical tool to probe the impact of modulating ER zinc levels and investigate ZIP7 as a novel druggable node in the Notch pathway.

Association of trabecular bone score (TBS) and prior fracture differs among minorities in NHANES 2005-2008

The study investigates the association of trabecular bone score (TBS) and fractures among minority populations. In NHANES 2005-2008, TBS was associated with history of fractures in Caucasian subjects but demonstrated somewhat weaker associations in African American and Mexican American women.

INTRODUCTION

Trabecular bone score (TBS), a textural analysis of the lumbar spine DXA image, predicts fractures well in Caucasian (CA) and Asian populations but is less well studied in African American (AA) and Mexican American (MA) subjects. It is not clear whether TBS is associated with or is predictive of fragility in these racial/ethnic groups.

METHODS

We analyzed data from subjects from NHANES 2005-2008 over the age of 40 who had TBS: 1178 CA, 467 AA, and 397 MA women and 1200 CA, 502 AA, and 386 MA men. TBS was categorized into normal, ≥ 1.310, partially degraded < 1.310, and > 1.230, or degraded, ≤ 1.230. History of fracture was assessed by questionnaire.

RESULTS

Among women, there was an increasing prevalence of fracture with worsening TBS category. However, when controlling for age, BMI, and low T-score, the association between TBS category and previous fracture was only significant in CA women (OR 1.49 per worsening category, 95% CI 1.20-1.85). In men, there was also an increase in the prevalence of fracture with worsening TBS category in all races/ethnicities. When controlling for age, BMI, and low T-score, the association between TBS category and previous fracture was only significant in CA men (OR 1.47 per worsening category, 95% CI 1.10-1.95), though analysis was somewhat limited by small fracture numbers.

CONCLUSIONS

The association of fracture and TBS varies by race/ethnicity and gender with weaker association observed in AA and MA women. More research is needed to define the proper use of TBS for predicting fractures in minority groups.

Pharmacological Reperfusion Therapy with Tenecteplase in 7,668 Indian Patients with ST Elevation Myocardial Infarction - A Real World Indian Experience

OBJECTIVE

This real-world, observational, prescription event monitoring study was conducted to evaluate safety and efficacy of indigenous tenecteplase (TNK-tPA) in Indian patients presenting with ST elevation myocardial infarction (STEMI).

METHODS

This is a multi-centric, observational, prescription event monitoring study. Data was collected for 7,668 patients from 1,307 investigator sites across India from January 2011 to February 2016.

RESULTS

Overall, 76.71% patients were hypertensive, 47.97% patients were diabetic, 42.01% had dyslipidemia, 24.35% had ischemic heart disease and 40.82% patients were smokers. The overall rate for achieving clinically successful thrombolysis by TNK was 93.34%. Delayed administration of tenecteplase yielded lower success rate (84.66%) as against those patients who received tenecteplase within 3 hours of symptoms (94.34%). 93.2% patients had chest pain resolution after pharmacological fibrinolysis. Overall 91.1% patients had 50% resolution of ST elevation at 90 minutes and mean time for 50% ST resolution was 72.06 minutes. Overall 53 patients died (mortality of 0.69%) before discharge. The incidence of bleeding (excluding stroke) was 1.77%, any stroke without ICH was 0.18% and any ICH was 0.38%.

CONCLUSION

The findings of this study further reinforce the safety and efficacy of indigenous TNK-tPA in Indian patients presenting with STEMI, including high-risk sub-groups. The study also highlights the importance of early reperfusion therapy.

Induction of cell death by tospoviral protein NSs and the motif critical for cell death does not control RNA silencing suppression activity

Groundnut bud necrosis virus induces necrotic symptoms in different hosts. Previous studies showed reactive oxygen species-mediated programmed cell death (PCD) resulted in necrotic symptoms. Transgenic expression of viral protein NSs mimics viral symptoms. Here, we showed a role for NSs in influencing oxidative burst in the cell, by analyzing H2O2 accumulation, activities of antioxidant enzymes and expression levels of vacuolar processing enzymes, H2O2-responsive microRNA 319a.2 plus its possible target metacaspase-8. The role of NSs in PCD, was shown using two NSs mutants: one in the Trp/GH3 motif (a homologue of pro-apototic domain) (NSsS189R) and the other in a non-Trp/GH3 motif (NSsL172R). Tobacco rattle virus (TRV) expressing NSsS189R enhanced the PCD response, but not TRV-NSsL172R, while RNA silencing suppression activity was lost in TRV-NSsL172R, but not in TRV-NSsS189R. Therefore, we propose dual roles of NSs in RNA silencing suppression and induction of cell death, controlled by different motifs.

Examining the influence of specificity ligands and ATP-competitive ligands on the overall effectiveness of bivalent kinase inhibitors

Background

Identifying selective kinase inhibitors remains a major challenge. The design of bivalent inhibitors provides a rational strategy for accessing potent and selective inhibitors. While bivalent kinase inhibitors have been successfully designed, no comprehensive assessment of affinity and selectivity for a series of bivalent inhibitors has been performed. Here, we present an evaluation of the structure activity relationship for bivalent kinase inhibitors targeting ABL1.

Methods

Various SNAPtag constructs bearing different specificity ligands were expressed in vitro. Bivalent inhibitor formation was accomplished by synthesizing individual ATP-competitive kinase inhibitors containing a SNAPtag targeting moiety, enabling the spontaneous self-assembly of the bivalent inhibitor. Assembled bivalent inhibitors were incubated with K562 lysates, and then subjected to affinity enrichment using various ATP-competitive inhibitors immobilized to sepharose beads. Resulting eluents were analyzed using Tandem Mass Tag (TMT) labeling and two-dimensional liquid chromatography-tandem mass spectrometry (2D–LC-MS/MS). Relative binding affinity of the bivalent inhibitor was determined by calculating the concentration at which 50% of a given kinase remained bound to the affinity matrix.

Results

The profiling of three parental ATP-competitive inhibitors and nine SNAPtag conjugates led to the identification of 349 kinase proteins. In all cases, the bivalent inhibitors exhibited enhanced binding affinity and selectivity for ABL1 when compared to the parental compound conjugated to SNAPtag alone. While the rank order of binding affinity could be predicted by considering the binding affinities of the individual specificity ligands, the resulting affinity of the assembled bivalent inhibitor was not predictable. The results from this study suggest that as the potency of the ATP-competitive ligand increases, the contribution of the specificity ligand towards the overall binding affinity of the bivalent inhibitor decreases. However, the affinity of the specificity components in its interaction with the target is essential for achieving selectivity.

Conclusion

Through comprehensive chemical proteomic profiling, this work provides the first insight into the influence of ATP-competitive and specificity ligands binding to their intended target on a proteome-wide scale. The resulting data suggest a subtle interplay between the ATP-competitive and specificity ligands that cannot be accounted for by considering the specificity or affinity of the individual components alone.

Electronic supplementary material

The online version of this article (doi:10.1186/s12953-017-0125-1) contains supplementary material, which is available to authorized users.

First record of Pepper cryptic virus 2 in chilli (Capsicum annuum) in India

The occurrence of Pepper cryptic virus 2 was confirmed by RT-PCR and partial sequencing of coat protein gene in chilli cultivars Jwalamukhi and Jwalasakhi grown in the experimental farm at IARI, New Delhi. To the best of our knowledge this is the first report of occurrence of cryptovirus in chilli in India.

Functional Outcome of Bipolar Prosthesis versus Total Hip Replacement in the Treatment of Femoral Neck Fracture in Elderly Patients

Introduction

The present study was performed to compare cemented total hip replacement (THR) with cemented bipolar prosthesis in the treatment of displaced fracture neck of femur in elderly patients.

Materials and Methods

This prospective study included 47 patients of greater than 60 years of age and having fracture of neck of femur, out of which 25 patients were managed by cemented bipolar prosthesis and remaining 22 were managed by cemented THR between June 2011 and June 2013. These patients were followed up post-operatively for two years, at 6, 12 and 24 months, for functional analysis using Modified Harris Hip Score.

Results

Modified Harris Hip Score was significantly higher in the THR group as compared to the bipolar prosthesis group at 6, 12 and 24 months post-operatively. Pain was almost similar in both the groups at all follow-up periods. Gait and range of motion was significantly higher in THR group as compared to bipolar prosthesis group at all-time point intervals.

Conclusion

Cemented THR is a better option as compared to cemented bipolar prosthesis based on our short term functional outcome for the management of fracture of neck of femur in elderly patients.

African Americans have lower TBS than whites among densitometry patients at a Chicago academic center

Trabecular bone score, an indirect measure of bone structure, may differ between ethnicities. We found that African Americans had lower trabecular bone score than do whites referred for densitometry, even when controlling for age and abdominal soft tissue thickness.

PURPOSE

Trabecular bone score (TBS), an indirect measure of bone structure, has been shown to predict fractures in predominantly white populations. Analysis of NHANES data revealed lower TBS in African Americans than in whites. However, it is not clear if this is true in patients referred for densitometry (where fracture risk stratification is most pertinent) or if ethnic differences in TBS may be related to differences in abdominal soft tissue (tissue thickness), which was not controlled for in the NHANES study.

METHODS

We retrospectively analyzed all BMD scans obtained at a university hospital in Chicago between 2011 and 2016.

RESULTS

There were 3187 women (51 % African American) and 675 men (32 % African American). African American women were older (69.6 ± 10.4 vs. 64.8 ± 1.3) and heavier (BMI 28.3 ± 4.7 vs. 25.4 ± 4.5) than whites were, while men were of similar age and BMI. African American women had higher T-scores at all sites (the lowest of T-scores, termed LowT, -1.5 ± 1.2 vs. -1.9 ± 1.0, p < 0.001) but lower TBS than white women even when adjusting for age and tissue thickness (1.231 ± 0.130 versus 1.251 ± 0.130, p < 0.001). While LowT was higher in African American men (-1.1 ± 1.2 vs. -1.5 ± 1.4, p < 0.001), TBS was lower than in white men even after adjusting for age and tissue thickness (1.232 ± 0.144 vs. 1.275 ± 0.144, p < 0.001).

CONCLUSIONS

African Americans had lower TBS than whites did, even with adjustment for age and tissue thickness. Ethnic differences in TBS should be considered when assessing fracture risk in clinical practice.

A Photoaffinity Labeling-Based Chemoproteomics Strategy for Unbiased Target Deconvolution of Small Molecule Drug Candidates

The combination of photoaffinity labeling (PAL) and quantitative chemoproteomics enables the comprehensive, unbiased determination of protein interaction profiles to support target identification of bioactive small molecules. This approach is amenable to cells in culture and compatible with pharmacologically relevant transmembrane target classes like G-protein coupled receptors and ions channels which have been notoriously hard to access by conventional chemoproteomics approaches. Here, we describe a strategy that combines PAL probe titration and competition with excess parental compounds with the goal of enabling the identification of specific interactors as well as assessing the functional relevance of a binding event for the phenotype under investigation.

Recent advances in role of chromium and its antioxidant combinations in poultry nutrition: A review

Poultry is reared in open side houses in most of the tropical countries, which results in huge temperature variation in shed causing stress resulting in increased demand of antioxidant supplementation. Since cooling of poultry houses or environment control is very expensive, thus methods focused on nutritional modifications appears to be the much logical approach. Stress increases mineral and vitamin mobilization from tissues and their excretion. Effect of some minerals and vitamin supplements such as chromium (Cr) and ascorbic acid to elevate the negative effects of environmental stress is well documented. Cr functions as an antioxidant and its deficiency are said to disrupt carbohydrate and protein metabolism. Cr has been utilized for weight gain, to improve feed conversion ratio, increase relative organ weight, muscle development, decrease cholesterol, increase high-density lipoprotein cholesterol, and improve nutrient digestion. Therefore, the present review discusses the beneficial aspects of Cr with its effect in different doses and antioxidant combinations to explore and promote its optimum utilization in poultry nutrition and production.

Conversion of a Single Polypharmacological Agent into Selective Bivalent Inhibitors of Intracellular Kinase Activity

Loss-of-function studies are valuable for elucidating kinase function and the validation of new drug targets. While genetic techniques, such as RNAi and genetic knockouts, are highly specific and easy to implement, in many cases post-translational perturbation of kinase activity, specifically pharmacological inhibition, is preferable. However, due to the high degree of structural similarity between kinase active sites and the large size of the kinome, identification of pharmacological agents that are sufficiently selective to probe the function of a specific kinase of interest is challenging, and there is currently no systematic method for accomplishing this goal. Here, we present a modular chemical genetic strategy that uses antibody mimetics as highly selective targeting components of bivalent kinase inhibitors. We demonstrate that it is possible to confer high kinase selectivity to a promiscuous ATP-competitive inhibitor by tethering it to an antibody mimetic fused to the self-labeling protein SNAPtag. With this approach, a potent bivalent inhibitor of the tyrosine kinase Abl was generated. Profiling in complex cell lysates, with competition-based quantitative chemical proteomics, revealed that this bivalent inhibitor possesses greatly enhanced selectivity for its target, BCR-Abl, in K562 cells. Importantly, we show that both components of the bivalent inhibitor can be assembled in K562 cells to block the ability of BCR-Abl to phosphorylate a direct cellular substrate. Finally, we demonstrate the generality of using antibody mimetics as components of bivalent inhibitors by generating a reagent that is selective for the activated state of the serine/threonine kinase ERK2.

Ternatin and improved synthetic variants kill cancer cells by targeting the elongation factor-1A ternary complex

Cyclic peptide natural products have evolved to exploit diverse protein targets, many of which control essential cellular processes. Inspired by a series of cyclic peptides with partially elucidated structures, we designed synthetic variants of ternatin, a cytotoxic and anti-adipogenic natural product whose molecular mode of action was unknown. The new ternatin variants are cytotoxic toward cancer cells, with up to 500-fold greater potency than ternatin itself. Using a ternatin photo-affinity probe, we identify the translation elongation factor-1A ternary complex (eEF1A·GTP·aminoacyl-tRNA) as a specific target and demonstrate competitive binding by the unrelated natural products, didemnin and cytotrienin. Mutations in domain III of eEF1A prevent ternatin binding and confer resistance to its cytotoxic effects, implicating the adjacent hydrophobic surface as a functional hot spot for eEF1A modulation. We conclude that the eukaryotic elongation factor-1A and its ternary complex with GTP and aminoacyl-tRNA are common targets for the evolution of cytotoxic natural products.

DOI:http://dx.doi.org/10.7554/eLife.10222.001

Many plants, fungi, and bacteria have evolved to produce small molecules that have powerful effects on the cells of other living organisms, and can even kill them. These naturally produced compounds are often used as starting points for developing new drugs. One such class of compounds are the cyclic peptides, which can be relatively easily produced in the laboratory and are able to penetrate cells. Some cyclic peptides have also proved to be useful for treating cancer and immune diseases, so researchers are keen to identify others that have similar effects. One promising prospect, called ternatin, is produced by several species of fungi. In high doses, ternatin can kill mammalian cells, but it was not clear how it does so.

To learn more, Carelli et al. searched a chemical database for cyclic peptides related to ternatin and identified several similar compounds that were reported to kill cancer cells. Inspired by the structures of these cyclic peptides, Carelli et al. synthesized modified versions of ternatin. One of these was 500 times more potent than ternatin, which means a much lower dose of the compound is still able to kill cancer cells.

Further experiments showed that ternatin blocks the production of new proteins in cells. Specifically, ternatin binds to a complex that includes a protein called elongation factor-1A (eEF1A). Mutations in a particular region of eEF1A prevent ternatin from killing cells, suggesting a potential binding site for ternatin.

The next challenge is to dissect the mechanism by which compounds binding to this site on eEF1A block protein synthesis and kill cells. A related challenge is to understand why certain cancer cells are hypersensitive to ternatin and other eEF1A inhibitors, while other cancer cells are relatively resistant. These questions are relevant to the development of eEF1A inhibitors as cancer treatments.

DOI:http://dx.doi.org/10.7554/eLife.10222.002

Ultrathin Silicon Sheet in the Management of Unilateral Post-traumatic Temporo-Mandibuar Joint Ankylosis in Children: A Good Alternative to Conventional Techniques

We have described a new technique of using ultra-thin silicon sheet (0.2 mm) between two transected bony ends for temporo-mandibular joint (TMJ) ankylosis in children with advantages of short operative time, minimal foreign material insertion and faster recovery time post-operatively which makes our technique a good alternative to conventional techniques. Our study is a non-randomized prospective study conducted on 10 children aged between 4 and 15 years who presented to our tertiary care institute with severe trismus after traumatic injury and were willing to undergo this new technique. The main outcome measure taken into consideration was difference between pre-operative, intra-operative (on table) and post-operative mouth opening (minimum 2 years follow-up). The pre-operative mouth opening in our cases varied from 1 to 5 mm. The intra-operative mouth opening achieved ranged from 2.8 to 3.2 cm. The mouth opening was about more than 2.7 cm in all our cases at 2 years of follow-up. Our technique is a good alternative to conventional techniques used for TMJ ankylosis in children but few more randomized controlled trials are required to assess its effectiveness in comparison to conventional techniques and for universal adoption of this technique.

Englerin A Agonizes the TRPC4/C5 Cation Channels to Inhibit Tumor Cell Line Proliferation

Englerin A is a structurally unique natural product reported to selectively inhibit growth of renal cell carcinoma cell lines. A large scale phenotypic cell profiling experiment (CLiP) of englerin A on ¬over 500 well characterized cancer cell lines showed that englerin A inhibits growth of a subset of tumor cell lines from many lineages, not just renal cell carcinomas. Expression of the TRPC4 cation channel was the cell line feature that best correlated with sensitivity to englerin A, suggesting the hypothesis that TRPC4 is the efficacy target for englerin A. Genetic experiments demonstrate that TRPC4 expression is both necessary and sufficient for englerin A induced growth inhibition. Englerin A induces calcium influx and membrane depolarization in cells expressing high levels of TRPC4 or its close ortholog TRPC5. Electrophysiology experiments confirmed that englerin A is a TRPC4 agonist. Both the englerin A induced current and the englerin A induced growth inhibition can be blocked by the TRPC4/C5 inhibitor ML204. These experiments confirm that activation of TRPC4/C5 channels inhibits tumor cell line proliferation and confirms the TRPC4 target hypothesis generated by the cell line profiling. In selectivity assays englerin A weakly inhibits TRPA1, TRPV3/V4, and TRPM8 which suggests that englerin A may bind a common feature of TRP ion channels. In vivo experiments show that englerin A is lethal in rodents near doses needed to activate the TRPC4 channel. This toxicity suggests that englerin A itself is probably unsuitable for further drug development. However, since englerin A can be synthesized in the laboratory, it may be a useful chemical starting point to identify novel modulators of other TRP family channels.

Engineered single-chain variable fragment antibody for immunodiagnosis of groundnut bud necrosis virus infection

Few studies have been done on engineered antibodies for diagnosis of tospovirus infections. The present study was undertaken to develop a single-chain variable fragment (scFv) for specific diagnosis of infection by groundnut bud necrosis virus (GBNV), the most prevalent serogroup IV tospovirus in India. Heavy chain (372 nucleotide [nt]) and light chain (363 nt) variable region clones obtained from a hybridoma were used to make an scFv construct that expressed a ~29-kDa protein in E. coli. The scFv specifically detected GBNV in field samples of cowpea, groundnut, mung bean, and tomato, and it did not recognize watermelon bud necrosis virus, a close relative of GBNV belonging to tospovirus serogroup IV. This study for the first time demonstrated the application of a functional scFv against a serogroup-IV tospovirus.

The asparagine residue in the FRNK box of potyviral helper-component protease is critical for its small RNA binding and subcellular localization

The multifunctional potyviral helper-component protease (HcPro) contains variable regions with some functionally conserved domains, such as the FRNK box. Natural variants occur at the FRNK box, a conserved central domain, known for its role in RNA binding and RNAi suppression activities, although no dominant natural variants for the N(182) residue are known to occur. Here, a mutant at HcPro(N182L) was developed to investigate its role in natural populations. Using in vitro studies, we found an increase in the small RNA (sRNA) binding potential of HcPro(N182L) without affecting its protein-protein interaction properties, suggesting that the presence of N(182) is critical to maintain threshold levels of sRNAs, but does not interfere in the self-interaction of HcPro. Furthermore, we found that expression of HcPro(N182L) in Nicotiana benthamiana affected plant growth. Transient expression of HcPro(N182L) induced reporter gene expression in 16c GFP transgenic plants more than HcPro did, suggesting that replacement of asparagine in the FRNK box favours RNA silencing suppression. HcPro was found to be distributed in the nucleus and cytoplasm, whereas HcPro(N182L) was observed only in cytoplasmic inclusion bodies in N. benthamiana leaves, when fused to a GFP tag and expressed by agro-infiltration, suggesting mutation favours oligomerization of HcPro. These findings suggest that amino acid N(182) of the conserved FRNK box may regulate RNA silencing mechanisms, and is required for maintenance of the subcellular localization of the protein for its multi-functionality. Hence, the N(182) residue of the FRNK box seems to be indispensable for potyvirus infection during evolution.

ST elevation after intracoronary administration of Papaverine for fractional flow reserve estimation

INTRODUCTION

Intracoronary (IC) papaverine which is one of the commonly used agents for Fractional Flow Reserve (FFR) estimation has been reported to cause transient ST elevation in some patients. This phenomenon has not been systematically studied.

MATERIAL AND METHODS

This is a prospective, observational study. Consecutive patients, who underwent FFR at our institute using IC papaverine from May 2012 to April 2013, were included. FFR was done when clinically indicated. The procedure involved administration of 20 mg papaverine (Paparin)--Troikaa, Ahmedabad) as a fast bolus by intracoronary route followed by a 10 cc contrast flush, following which pressure measurements were made. Continuous ECG recording by Philips Hemodynamic Laboratory was obtained for all patients throughout the procedure. Post procedure, they were observed for any delayed effects and eventual outcome was documented. Fischer's mid-p test was used for statistical analysis.

RESULT

Twenty-five patients (18 males, 7 females, mean age 57.9 ± 20 years) underwent FFR using Papaverine. The mean LVEF was (51 ± 15%). Fourteen patients (56%) developed transient ST elevation ≥0.5 mm in one or more leads which resolved spontaneously in all cases without any sequelae. The presence of a significant lesion either in the coronary artery being evaluated or in a remote coronary artery did not predict the ST elevation. 70.5% of diabetics (p = 0.02), 75% of hypertensives (p = 0.008) and 75% of patients with LVH (p = 0.008) had ST elevation. None of the 5 patients without any one of these comorbidities showed ST elevation.

CONCLUSION

Transient ST elevation occurs in a significant proportion of cases receiving IC papaverine which is not associated with any adverse clinical outcomes. Micro vascular dysfunction is the most likely mechanism of this phenomenon.

Pharmacologic reperfusion therapy with indigenous tenecteplase in 15,222 patients with ST elevation myocardial infarction - the Indian Registry

OBJECTIVE

To study the efficacy and safety of single intravenous bolus administration of indigenously developed tenecteplase (TNK-tPA) in the management of patients with ST-elevation myocardial infarction (STEMI) in clinical practice.

METHODS

Observational, prescription-event monitoring study.

RESULTS

Data of 15,222 patients who had STEMI and received weight adjusted TNK injection was analyzed. Overall 95.43% patients had clinically successful thrombolysis (CST). In the different subgroups, hypertensives, diabetics, smokers and hyperlipidemic patients had CST rates comparable to the general patient data. CST rates were significantly lower in the elderly patients (>70 years; 92.11%; p < 0.0001), in patients with history of Ischemic Heart Disease (IHD, 93.86%; p = 0.0004) and in patients receiving delayed treatment (>6 h after onset of chest pain; 85.38%; p < 0.0001). CST was significantly higher in patients who received an early thrombolysis (<3 h after onset of chest pain; 96.54%; p = 0.006). Overall mortality was 1.69%, while it was significantly higher in the elderly (4.42%), patients with history of IHD (2.67%), females (2.93%) and in those who received delayed treatment (4.98%). The overall incidences of intracranial hemorrhage (ICH), bleeding excluding ICH, stroke and ventricular tachyarrhythmia were 0.39%, 2.01%, 0.16% and 2.35% respectively. Age >70 years, diabetes, hyperlipidemia and history of IHD were associated with a higher incidence of heart failure, myocardial re-infarction or ventricular tachyarrhythmias. However, incidence of ICH and bleeding other than ICH was comparable amongst all patient subgroups.

CONCLUSION

This study confirms the safety and efficacy of indigenous tenecteplase in Indian patients with STEMI, including high risk subgroups. It also highlights the fact that delayed treatment denotes denial of benefits of pharmacologic reperfusion therapy.

A highly efficient and compact long pulse Nd:YAG rod laser with 540 J of pulse energy for welding application

We have developed an efficient and high average power flash lamp pumped long pulse Nd:YAG laser capable of generating 1 kW of average output power with maximum 540 J of single pulse energy and 20 kW of peak power. The laser pulse duration can be varied from 1 to 40 ms and repetition rate from 1 to 100 Hz. A compact and robust laser pump chamber and resonator was designed to achieve this high average and peak power. It was found that this laser system provides highest single pulse energy as compared to other long pulsed Nd:YAG laser systems of similar rating. A slope efficiency of 5.4% has been achieved, which is on higher side for typical lamp pumped solid-state lasers. This system will be highly useful in laser welding of materials such as aluminium and titanium. We have achieved 4 mm deep penetration welding of these metals under optimized conditions of output power, pulse energy, and pulse duration. The laser resonator was optimized to provide stable operation from single shot to 100 Hz of repetition rate. The beam quality factor was measured to be M(2) ~ 91 and pulse-to-pulse stability of ±3% for the multimode operation. The laser beam was efficiently coupled through an optical fiber of 600 μm core diameter and 0.22 numerical aperture with power transmission of 90%.

First Report of Lettuce mosaic virus Infecting Lactuca sativa in India

In January 2012, lettuce (Lactuca sativa L.) plants (19 out of 38) of one of the accessions (EC687345, variety NVRS-10:001818) exhibiting mild mosaic and stunted growth symptoms were observed at the Indian Agricultural Research Institute (IARI) experimental farm, New Delhi. Similar disease symptoms in lettuce plants in India were previously described (3) and the associated virus was characterized for host range, dilution end point, thermal inactivation point, and longevity in vitro. In this study, definitive molecular evidence is presented for the presence of Lettuce mosaic virus (LMV) infecting lettuce in India. Analysis of preparations from leaves of symptomatic samples with an electron microscope revealed flexuous virus particles measuring 750 × 13 nm, suggesting the association of a potyvirus (4). To identify the potyvirus infecting these lettuce plants, the 3' terminal portion of the genome including the part of the nuclear inclusion b (NIb), complete coat protein (CP) region, and 3' untranslated region (UTR) was amplified by RT-PCR, cloned, and sequenced. Total RNA was extracted from infected leaves using an RNeasy Plant Mini Kit (Qiagen, Valencia, CA) and subjected to RT-PCR using potyvirus specific forward (5' ACCACAGGATCCGGBAAYAAYAGYGGDCARCC 3') and reverse (5' CACGGATCCCGGG(T17)V 3') primers (2). PCR products (~1.8 kb) were cloned into pGEM-T Easy vector (Promega, Madison, WI) and sequenced (GenBank Accession No. JQ794776). Sequence comparisons revealed the CP of the virus infecting lettuce (834 bp) shared 96 to 100% nucleotide and deduced amino acid sequence identity with the corresponding regions of LMV isolates AJ306288 and AJ297630 from the United Kingdom, CAA46603 and NC003605 from the United States, AJ278854 and AJ278854 from Brazil, and AJ488153 from China, thus complying with the cut off range of 90 to 99% for identifying isolates/strains of the same virus (1). Similarly, 99 to 100% nucleotide sequence identity was observed with the corresponding region of the 3'UTR (245 bp) while 93 to 96% nucleotide identity of NIb region (654 bp) with LMV isolates. These results confirm that the virus infecting the symptomatic lettuce plants was an isolate of LMV. The amino acid sequences (DAG and WCIEN) conserved among majority of potyviruses were also present. Since the virus is aphid transmissible, its natural infection on other hosts and spread can't be ruled out. References: (1) M. J. Adams et al. Arch Virol. 150:459, 2005. (2) A. Gibbs and A. Mackenzie. J. Virol. Methods 63:9, 1997. (3) T. K. Nariani and P. S. Pathanian. Indian Phytopathol. 13:172, 1960. (4) D. D. Shukla et al. The Potyviridae, page 338, 1994.

Study on incidence of bleeding in hospitalized patients after antithrombotic therapy at a tertiary care hospital

OBJECTIVES

To monitor the different antithrombotic drug combinations, determine the incidence, magnitude of bleeding and the association of HAS-BLED risk scoring schema with the magnitude of bleeding as defined using TIMI bleeding criteria.

METHODS

A prospective observational study in a cohort of patients for a period of 8 months, at one of the tertiary care center-Krishna Institute of Medical Sciences, Hyderabad, was conducted. Consecutive patients were enrolled and followed from the date of admission till the adverse events are perceived/date of discharge. Pearson Correlation Statistics (Fisher's z Transformation) is applied to assess the association between HAS-BLED risk factors and the total risk score with bleeding criteria.

RESULTS

A total of 400 cases were collected during the 8-month study period, of which 372 satisfied the inclusion criteria. Among them 34 (9.1%) bleeding cases were reported with mean (+/- SD) age of 57.8 (+/- 14.19) years. Bleeding occurred mostly in males 79.4% and a HAS-BLED Score of > or = 3 has been observed in 67.6% (n = 23) patients out of 34 bled patients. Two antiplatelets + One anticoagulant is the most common combination which caused bleeding in 41.2% (n = 14). Stroke history, bleeding predisposition, labile INR's are the HAS-BLED risk factors which are significant (< 0.05) with the TIMI Bleeding Criteria.

CONCLUSION

There was a linear correlation between the HAS-BLED risk score and the TIMI bleeding criteria-higher the risk score the more frequent is the incidence of major bleeding. A HAS-BLED risk score of > or = 3 is associated with TIMI major bleeding.

Abstract P3-12-03: Combined targeting of HER2 and VEGFR2 for effective treatment of HER2-amplified breast cancer brain metastases

Brain metastases remain a serious obstacle in the treatment of patients with human epidermal growth factor receptor-2 (HER2)-amplified breast cancer. Unlike HER2-amplified breast tumors growing in extra-cranial locations, brain metastases do not respond well to HER2 inhibitors and are often the reason for treatment failure. One of the major challenges in studying brain metastases is the lack of preclinical models. We developed a HER2-amplified mouse model of brain metastasis using an orthotopic xenograft of BT474 cells in mice. As seen in patients, the HER2 inhibitors trastuzumab and lapatinib failed to contain brain metastatic tumor growth.

Based on previous findings from our laboratory suggesting a role of vascular endothelial growth factor (VEGF) in the resistance of HER2-overexpressing breast cancer brain metastases to trastuzumab, we combined HER2 inhibitors with the anti-VEGFR2 antibody DC101. The combination of either trastuzumab and DC101 or lapatinib and DC101 significantly slowed metastatic tumor growth in the brain, and resulted in a striking improvement in overall survival. The benefit is due largely to an anti-angiogenic effect. The combination of anti-HER2 and anti-VEGFR2 therapy reduced both the total and functional microvascular density in the brain metastatic tumors. Moreover, tumor tissues under combination therapy showed a marked increase in necrosis.

Preclinical and clinical evidence suggest that the combination of trastuzumab and lapatinib is superior to either agent alone – though this has never been tested in the brain metastatic setting. We consistently observed increased phosphorylation of HER2 in breast tumor cells growing in the brain compared with the mammary fat pad. In addition, while short-term lapatinib treatment significantly reduced HER2 activation in the brain, it could do so only to the level of that observed in the untreated mammary fat pad - and this effect disappeared over time. We hypothesized that more pronounced HER2 inhibition would be beneficial to these brain metastases with increased HER2 activation. We show here a significant growth delay with the combination of the two HER2 inhibitors compared with monotherapy. Moreover, we found a dramatic brain metastatic tumor growth delay in mice treated with both HER2 inhibitors, trastuzumab and lapatinib, and DC101. The triple combination prolonged overall survival 5 times longer than control-treated mice.

Brain metastasis from breast cancer is considered the “final frontier” of breast cancer research and treatment. Our findings support the clinical development of a three-drug regimen of trastuzumab, lapatinib and a VEGF pathway inhibitor for the treatment of HER2-amplified breast cancer brain metastases. While the anti-VEGF antibody bevacizumab in combination with trastuzumab and chemotherapy has shown some promise in HER2-positive metastatic breast cancer patient, there are no data on its efficacy in the context of brain metastases. A clinical trial is now recruiting patients to evaluate the efficacy of bevacizumab in breast cancer patients with active brain metastases, including its combination with trastuzumab in patients with HER2-positive disease. This trial may provide clinical evidence for the approach presented here.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-12-03.

First Report of Grapevine leafroll-associated virus 1 Infecting Grapevines in India

Viticulture, one of the most remunerative farming enterprises of India, is seriously affected by leafroll disease, which accounts for 62% of the losses in grape production worldwide due to viral diseases (4). Grapevine leafroll-associated virus 3 and 1 (GLRaV-3 and GLRaV-1) of the family Closteroviridae are the two most common viruses associated with the leafroll disease of grapevine (1). GLRaV-3 was previously confirmed in India through RT-PCR, cloning, and sequencing (2). A survey was conducted during 2010 and 2011 in the Nashik and Pune regions of western India and reddening of interveinal areas and downward rolling, typical symptoms of leafroll disease in dark fruited cultivars, were observed, first in 2010 and subsequently in 2011. Fourteen leafroll symptomatic samples from seven cultivars of seven vineyards were collected during 2011. Samples were subjected to double antibody sandwich (DAS)-ELISA using commercially available antibodies against GLRaV-3 and GLRaV-1 (Bioreba, Reinach, Switzerland) (2). An asymptomatic sample from another cultivar of a different vineyard and samples from two plantlets of two different cultivars produced in tissue culture were used as negative controls. GLRaV-1 was detected in two cultivars, Shiraj (Nashik region) and Pinot Noir (Pune region) using DAS-ELISA. GLRaV-1 was detected either alone in cultivar Pinot Noir or as mixed infection with GLRaV-3 in cultivar Shiraj. To further confirm the presence of GLRaV-1 in these two cultivars, crude extract from petioles of these two cultivars were subjected to one step reverse transcription (RT)-PCR using GLRaV-1 specific primers pORF9F and pORF9R (GGCTCGAGATGGCGTCACTTATACCTA and CCTCTAGACACCAAATTGCTAGCGA, respectively) (3). The ˜650 bp amplicons were cloned in pGEM-T easy vector and three independent clones of each amplicon were sequenced in both directions. The cloned amplified product was 646 bp, including 630 bp of p24 protein (ORF9) of GLRaV-1. Comparative sequence analysis, using the BioEdit 7.0.3 program ( http://www.mbio.ncsu.edu/BioEdit/BioEdit.html ), of ORF9 of the virus under study from the cultivars Pinot Noir and Shiraj shared maximum sequence identity of 95.8 and 96.1%, respectively, at the nucleotide level with the Clatervine isolate from the United States (GenBank Accession No. HQ833477). The corresponding values of maximum identities at the amino acid level were 96.6 and 96.1%, respectively, with the same Clatervine isolate. The maximum identity between these two isolates of GLRaV-1 was 96.1% at nucleotide level and 95.7% at amino acid level. To the best of our knowledge, this study represents the first report of GLRaV-1 from India. Grape production in India could be impacted by this virus; thus, identification of the virus is important. References: (1) B. Akbas et al. Hort. Sc. (Prague). 36: 97, 2009. (2) S. Kumar et al. Virus Genes. 45:195, 2012. (3) A. Little and M. A. Rezaian. Arch. Virol. 151:753, 2006. (4) A. Little et al. Virus Res. 80:109, 2001.

First Report of Groundnut bud necrosis virus in Tomato in Bangladesh

An unusual disease of tomato characterized by leaf mottling and necrotic streaks on veins, shortened internodes, necrosis of terminal buds, and concentric rings on fruits was observed during 2010 to 2011 surveys in tomato growing regions of Godagari Upzila, Rajshahi district, Bangladesh. Disease incidence in popularly grown F1 hybrid cultivars, which include Sobal, Abhiruchi, Salamat, Bangobir, and BARI hybrid tomato-5 and -6 in about 40 commercial fields, ranged from 40 to 90%. Extracts from the field samples (n = 10) reacted with polyclonal antiserum to Groundnut bud necrosis virus (GBNV) in direct antigen coated ELISA, suggesting the association of a tospovirus antigenically related to serogroup IV topsovirus (1). To identify whether the tospovirus was a distinct virus species, ELISA-positive samples were subjected to total RNA extraction with an RNeasy Plant Mini Kit (Qiagen, Chatsworth, CA) followed by reverse transcription (RT)-PCR with tospovirus-specific primers (5'-ATGGTTGAAAAGAGCAAGAATGATGC-3') and degenerate primer (5'-CTTCTTATGAAGTGTACTCACCATAAGTCATCC-3') derived from the conserved sequences of GBNV, Watermelon bud necrosis virus (WBNV), and Capsicum chlorosis virus (CaCV) (2). The RT-PCR product was cloned into pGEM-T Easy vector (Promega, Madison, WI) and sequenced at Department of Biochemistry, University of Delhi, South Campus, Delhi, India (GenBank Accession No. JQ692083). The sequences of cloned fragments were assembled. Analysis of the 477-bp region of the nucleocapsid protein (N) gene revealed that the tomato tospovirus shared maximum identity both at the nucleotide (96%) and amino acid (97%) levels with the corresponding region of GBNV. In contrast, only 78 to 81% and 85 to 87% identity at nucleotide and amino acid levels, respectively, was observed with the corresponding region of the N genes of CaCV, WBNV, and Watermelon silver mottle virus. These results suggested the association of GBNV with the diseased tomato samples. To our knowledge, this is the first report of GBNV infecting tomato in Bangladesh and regular surveys are necessary to ascertain the prevalence and incidence of GBNV in other crops. References: (1) R. K. Jain et al. J. Virol. Methods 130:162, 2005. (2) M. Tsompana and J. W. Moyer. Tospovirus. Page 157 in: Encyclopedia of Virology. Academic Press, New York, 2009.

Protein surface recognition by porphyrin-based receptors

Protein surface recognition is largely unexplored owing to the large solvent exposed surface and lack of proper molecular scaffolds to match the binding residues. This review describes the design, synthesis, and fluorescence binding studies of functionalized porphyrins aimed at targeting surface residues of proteins through complementary recognition. The pattern of lysine residues surrounding the heme-edge of horse heart cytochrome c has been targeted by tetraphenylporphyrin and tetrabiphenylporphyrin receptors that bind with nano- and sub-nanomolar affinity. Other designed porphyrin-based receptors also recognize potassium channel as a target. The strategies for protein surface recognition offer a new use for porphyrins as molecular scaffolds.

Aerobic rice genotypes displayed greater adaptation to water-limited cultivation and tolerance to polyethyleneglycol-6000 induced stress

Water scarcity and drought have seriously threatened traditional rice cultivation practices in several parts of the world including India. In the present investigation, experiments were conducted to see if the water-efficient aerobic rice genotypes developed at UAS, Bangalore (MAS25, MAS26 and MAS109) and IRRI, Philippines (MASARB25 and MASARB868), are endowed with drought tolerance or not. A set of these aerobic and five lowland high-yielding (HKR47 and PAU201, Taraori Basmati, Pusa1121 and Pusa1460) indica rice genotypes were evaluated for: (i) yield and yield components under submerged and aerobic conditions in field, (ii) root morphology and biomass under aerobic conditions in pots in the nethouse, (iii) PEG-6000 (0, -1, -2 and -3 bar) induced drought stress at vegetative stage using a hydroponic culture system and (iv) polymorphism for three SSR markers associated with drought resistance traits. Under submerged conditions, the yield of aerobic rice genotypes declined by 13.4-20.1 % whereas under aerobic conditions the yield of lowland indica/Basmati rice varieties declined by 23-27 %. Under water-limited conditions in pots, aerobic rice genotypes had 54-73.8 % greater root length and 18-60 % higher fresh root biomass compared to lowland indica rice varieties. Notably, root length of MASARB25 was 35 % shorter than MAS25 whereas fresh and dry root biomass of MASARB25 was 10 % and 64 % greater than MAS25. The lowland indica were more sensitive to PEG-stress with a score of 5.9-7.6 for Basmati and 6.1-6.7 for non-aromatic indica rice varieties, than the aerobic rice genotypes (score 2.7-3.3). A set of three microsatellite DNA markers (RM212, RM302 and RM3825) located on chromosome 1 which has been shown to be associated with drought resistance was investigated in the present study. Two of these markers (RM212 and RM302) amplified a specific allele in all the aerobic rice genotypes which were absent in lowland indica rice genotypes.

First Report of Garlic virus X Infecting Garlic in India

Garlic (Allium sativum) is an important crop in several states of India. Filamentous viruses such as Onion yellow dwarf virus (OYDV), Shallot latent virus (SLV), and Garlic common latent virus (GarCLV) have been reported previously in different garlic cultivars from India (4). These viruses are transmitted from generation to generation through cloves and cause severe reduction in yield and quality. During December 2010, garlic plants were observed with mosaic leaf symptoms and stunting in an experimental field at the Indian Agricultural Research Institute, Delhi. Cloves and leaves from 3-month-old symptomatic plants of five different cultivars (G-282, IC-375416, Ruag, Yamuna Safed, and ACC-40), originally from different regions of India, were collected from the field in Delhi and total RNA was extracted using an RNeasy Plant Mini Kit (Qiagen, Valencia, CA). The presence of OYDV and GarCLV was confirmed by reverse transcription (RT)-PCR in all cultivars, while the presence of SLV was only confirmed in cv. G-282 by RT-PCR. Since Allexiviruses are common in garlic, their detection in cloves was confirmed by RT-PCR using primers ALLEX 1 and ALLEX 2 (2). An ~200-bp amplification product was observed in all five cultivars. To further characterize the Allexivirus in these cultivars, an amplicon of ~900 bp was amplified with Allex-CP (1) and ALLEX 2 (2) primers and cloned and sequenced. BLAST analysis of the nucleotide sequences from five garlic cultivars showed identity with different allexiviruses, Garlic virus A (GarV-A) (74 to 83%), Garlic virus E (GarV-E) (74 to 80%), Garlic virus D (GarV-D) (76 to 79%), and Garlic virus X (GarV-X) (75 to 78%). Since species demarcation in the genus Allexivirus is based on the coat protein (CP) gene (3), another set of primers, 5'-MYT KGA GTG GCT VAC ACA YAT-3' and 5'-ATT RAA GTC GTG RGG ATG CAT-3' was designed. These primers were derived from conserved regions of ORF4 and ORF5 (CP) sequences of allexiviruses available in the NCBI database and used in RT-PCR to obtain the complete CP. An ~1.5-kb amplicon was obtained only in cv. G-282 that originated from the southern part of India. A similar amplicon was obtained from Chenopodium amaranticolor mechanically inoculated with leaf sap from cv. G-282. Sequences (1,422 bp) obtained from three clones each from garlic cv. G-282 and C. amaranticolor were identical and BLAST analysis of the consensus nucleotide sequence showed maximum identity of 75 to 81% with isolates of GarV-X. The 1,422 nucleotide sequence was comprised of 690 bp of ORF4 (partial) and 732 bp of the CP. The coat protein sequence (GenBank Accession No. HQ822272) shared a 79.6 to 81.1% identity in nucleotide and 89.3 to 90.9% in amino acid sequence with different isolates of GarV-X (GenBank Accession Nos. AJ292229, U89243, and GQ475426). To our knowledge, this is the first report of GarV-X in a garlic cultivar from India. The characterization and identification of allexiviruses is important for production of virus-free garlic plants through tissue culture in India. References: (1) J. Chen et al. Arch. Virol. 149:435, 2004. (2) C. I. Dovas et al. J. Phytopathol.149:731, 2001. (3) C. M. Fauquet et al. Virus Taxonomy-VIIIth Report of the ICTV, Academic Press, London, 2005. (4) S. Majumder and V. K. Baranwal. Plant Dis. 93:106, 2009.

Role of measurement of antioxidant enzymes in evaluation of antioxidant therapy in tobacco abusers with oral leukoplakia

Antioxidants are widely used in chemoprevention of malignancy. Numerous studies in medical literature have reported the evaluation of this treatment protocol by indirect methodology-epidemiology, invitro studies, pharmacology and animal models etc. However, there is a paucity of literature on the measurement of antioxidant enzymes as a parameter for assessing the outcome of antioxidant therapy. This study explores the efficacy and outcome of antioxidant enzyme assay in relation to antioxidant therapy in tobacco abusers, hitherto unreported in medical literature. A prospective cohort study with control in 50 patients carried out at a tertiary care teaching Institution (Institute of Medical Sciences, Banaras Hindu University, Varanasi, India). Out of these patients, 10 patients acted as control, rest 40 patients-all tobacco users in some form, were divided into three groups on the basis of histopathological grading of dysplasia-no dysplasia, mild or moderate dysplasia. The levels of Lipid peroxidase (LPO), Superoxide dismutase (SOD) and Catalase (CAT) in mucosa and serum were assayed in each group, and re-evaluated at the end of 3 months after intervention with antioxidant treatment. To detect any alteration in degree of dysplasia a repeat biopsy was also done at the end of 3 months. The results were statistically analysed using paired t test. A statistically significant decrease in level of LPO and SOD, and an increase in CAT levels were recorded both in mucosa and serum. However, no change in dysplasia and no new case of dysplasia were observed. Further, antioxidant treatment was continued for a year and the final out come of the lesion was assessed by "Carter's criteria". A final success rate of 74.19% was recorded in terms of partial or complete regression of the lesion. This study confirms the therapeutic efficacy of antioxidants in oral leukoplakia, and cites the importance of LPO, SOD and CAT in evaluating the efficacy of antioxidant treatment. However, the study failed to elucidate any relationship between enzyme measurement and the final outcome of the lesion.

Two IPMC Fingers Based Micro Gripper for Handling

This paper presents the behavior of two finger based micro gripper which is made of Ionic Polymer Metal Composite (IPMC), an Electro Active Polymer (EAP). An IPMC shows great potential as high-displacement and light weight actuator. Low mass force generation capability is utilized for micro gripping in micro assembly. IPMC responds to low voltage in the range of 0-3V. The material contains an electrolyte which transport ions in response to an external electric field. IPMC actuation for micro gripping is produced by deflecting material according to bending moment theory. An external electric field generated by suitable RC circuit causes this deflection. It is found that an IPMC actuates from 1–5 seconds. The maximum jaw opening and closing position of micro gripper are found to be 5 mm and 0.5 mm respectively. The effect of tempearture, as observed, shows that the acceptable limit varies from 23.1°C to 30.4°C while an IPMC is in operation. An experimental proto type is developed for evaluation of performance.