Transcriptional regulation of CYR61 and CTGF by LM98: a synthetic YAP-TEAD inhibitor that targets in-vitro vasculogenic mimicry in glioblastoma cells.

Glioblastoma (GBM) is a highly angiogenic malignancy of the central nervous system that resists standard antiangiogenic therapy, in part because of an alternative process to angiogenesis termed vasculogenic mimicry. Intricately linked to GBM, dysregulation of the Hippo signaling pathway leads to overexpression of YAP/TEAD and several downstream effectors involved in therapy resistance. Little is known about whether vasculogenic mimicry and the Hippo pathway intersect in the GBM chemoresistance phenotype. This study seeks to investigate the expression patterns of Hippo pathway regulators within clinically annotated GBM samples, examining their involvement in vitro regarding vasculogenic mimicry. In addition, it aims to assess the potential for pharmacological targeting of this pathway. In-silico analysis of the Hippo signaling members YAP1, TEAD1, AXL, NF2, CTGF, and CYR61 transcript levels in low-grade GBM and GBM tumor tissues was done by Gene Expression Profiling Interactive Analysis. Gene expression was analyzed by real-time quantitative PCR from human U87, U118, U138, and U251 brain cancer cell lines and in clinically annotated brain tumor cDNA arrays. Transient gene silencing was performed with specific small interfering RNA. Vasculogenic mimicry was assessed using a Cultrex matrix, and three-dimensional capillary-like structures were analyzed with Wimasis. CYR61 and CTGF transcript levels were elevated in GBM tissues and were further induced when in-vitro vasculogenic mimicry was assessed. Silencing of CYR61 and CTGF, or treatment with a small-molecule TEAD inhibitor LM98 derived from flufenamic acid, inhibited vasculogenic mimicry. Silencing of SNAI1 and FOXC2 also altered vasculogenic mimicry and reduced CYR61/CTGF levels. Pharmacological targeting of the Hippo pathway inhibits in-vitro vasculogenic mimicry. Unraveling the connections between the Hippo pathway and vasculogenic mimicry may pave the way for innovative therapeutic strategies.

Predicting drought stress under climate change in the Southern Central Highlands of Vietnam.

In the Southern Central Highlands of Vietnam, droughts occur more frequently, causing significant damage and impacting the region's socio-economic development. During the dry season, rivers, streams, and reservoirs often face limited water availability, exacerbated in recent years by increasing drought severity. Recognizing the escalating severity of droughts, the study offers a novel contribution by conducting a comprehensive analysis of surface water resource distribution in Lam Dong province, focusing on assessing water demand for agricultural production, a crucial factor in ensuring sustainable crop growth. Two scenarios, Current-2020 (SC1) and Climate Change-2025 (SC2), are simulated, with SC2 based on climate change and sea level rise scenarios provided by the Ministry of Natural Resources and Environment (MONRE). These scenarios are integrated into the MIKE-NAM and MIKE-HYDRO basin models, allowing for a thorough assessment of the water balance of Lam Dong province. Furthermore, the study utilizes the Keetch-Byram Drought Index (KBDI) to measure drought severity, revealing prevalent dry and moderately droughty conditions in highland districts with rainfall frequency ranging from 50 to 85%. Severe drought conditions occur with a rainfall frequency of 95%, indicating an increased frequency and geographic scope of severe droughts. Additionally, the study highlights that under abnormally dry conditions, water demand for the winter-spring crop is consistently met at 100%, decreasing to 85%, 80%, and less than 75% for moderate, severe, and extreme droughts, respectively. These findings offer insights into future drought conditions in the Lam Dong province and their potential impact on irrigation capacity, crucial for adaptation strategies.

Synthesis of 1-Methylcyclopropyl Aryl Ethers from Phenols Using an Alkenylation-Cyclopropanation Sequence.

1-Methylcyclopropyl aryl ethers (McPAEs) can be viewed as cyclized derivatives of their O-tert-butyl counterparts. Although these compounds can find use in medicinal chemistry, they are much less represented in the literature than their aryl cyclopropyl ether analogues. McPAEs are generally prepared via an SNAr reaction using 1-methylcyclopropanol. However, this method works exclusively with highly deactivated arenes. We report herein a two-step sequence to access McPAEs consisting of the 1-methylvinylation of phenols followed by cyclopropanation of the corresponding 1-methylvinyl aryl ethers. Isomeric mono- and dimethyl analogues were also prepared using this sequence.

Development of LM-41 and AF-2112, two flufenamic acid-derived TEAD inhibitors obtained through the replacement of the trifluoromethyl group by aryl rings.

The Hippo pathway regulates organ size and tissue homeostasis by controlling cell proliferation and apoptosis. The YAP-TEAD transcription factor, the downstream effector of the Hippo pathway, regulates the expression of genes such as CTGF, Cyr61, Axl and NF2. Aberrant Hippo activity has been identified in multiple types of cancers. Flufenamic acid (FA) was reported to bind in a liphophilic TEAD palmitic acid (PA) pocket, leading to reduction of the expression of Axl and NF2. Here, we show that the replacement of the trifluoromethyl moiety in FA by aromatic groups, directly connected to the scaffold or separated by a linker, leads to compounds with better affinity to TEAD. Co-crystallization studies show that these compounds bind similarly to FA, but deeper within the PA pocket. Our studies identified LM-41 and AF-2112 as two TEAD binders that strongly reduce the expression of CTGF, Cyr61, Axl and NF2. LM-41 gave the strongest reduction of migration of human MDA-MB-231 breast cancer cells.

Region of freshwater influence (ROFI) and its impact on sediment transport in the lower Mekong Delta coastal zone of Vietnam.

The delta of the Mekong River is one of the largest in the world, with the Mekong River carrying a large amount of sediments in its Region of Freshwater Influence (ROFI). This study investigates the flow structure and movement of both suspended and bedload sediments in the ROFI of the Lower Mekong Delta (LMD) in order to identify areas prone to sediment accretion and erosion. This is accomplished by applying the three-dimensional Coastal and Regional Ocean COmmunity (CROCO) model and then calculating the sediment budget of different stretches of the coastline. The model outputs, depicting areas experiencing sediment accretion and erosion along the coastline of the LMD, are then compared against observations obtained during the period 1990-2015 and demonstrate the ability of the model to identify areas particularly prone to erosion and where preventive actions against coastal erosion should focus.

Zoning the suitability of the western Mekong Delta for paddy rice cultivation and aquaculture under current and future environmental conditions.

Ca Mau and Kien Giang, the two provinces of the Mekong Delta bordering the Gulf of Thailand, are facing major environmental challenges affecting the agriculture and aquaculture sectors upon which many livelihoods in this region depend on. This study maps the suitability of these two provinces for paddy rice cultivation and shrimp farming according to soil characteristics and current and future environmental conditions for variables found to significantly influence the yield of those two sectors, i.e., the level of saltwater intrusion, water availability for rainfed agriculture, and the length of the growing period. Future environmental conditions were simulated using the MIKE 11 hydrodynamic model forced by four hydrodynamic scenarios, each one representing different extents of saltwater intrusion during both the dry and rainy seasons, while also considering the availability of water resources for rainfed agriculture. The suitability zoning was performed using a GIS-based analytic hierarchy process (AHP) approach, resulting in the categorisation of the land according to four suitability levels for each sector. The analysis reveals that paddy rice cultivation will become more suitable to Kien Giang province while shrimp farming will be more suitable to Ca Mau province if the simulated future environmental conditions materialise. A suitability analysis is essential for optimal utilisation of the land. The approach presented in this study will inform the regional economic development master plan and provide guidance to other delta regions experiencing severe environmental changes and wishing to consider potential future climatic and sea level changes, and their associated impacts, in their land use planning.

Copper-Promoted N-Arylation of the Imidazole Side Chain of Protected Histidine by Using Triarylbismuth Reagents.

The N-arylation of the side chain of histidine by using triarylbismuthines is reported. The reaction is promoted by copper(II) acetate in dichloromethane at 40 °C under oxygen in the presence of diisopropylethylamine and 1,10-phenanthroline and allows the transfer of aryl groups with substituents at any position of the aromatic ring. The reaction shows excellent functional group tolerance and is applicable to dipeptides where the histidine is located at the N terminus. A histidine-guided backbone N-H arylation was observed in dipeptides where the histidine occupies the C terminus.

Synthesis of NVS-BPTF-1 and evaluation of its biological activity.

BPTF (bromodomain and PHD finger containing transcription factor) is a multidomain protein that plays essential roles in transcriptional regulation, T-cell homeostasis and stem cell pluripotency. As part of the chromatin remodeling complex hNURF (nucleosome remodeling factor), BPTF epigenetic reader subunits are particularly important for BPTF cellular function. Here we report the synthesis of NVS-BPTF-1, a previously reported highly potent and selective BPTF-bromodomain inhibitor. Evaluation of the impact of the inhibition of BPTF-bromodomain using NVS-BPTF-1 on selected proteins involved in the antigen processing pathway revealed that exclusively targeting BPTF-bromodomain is insufficient to observe an increase of PSMB8, PSMB9, TAP1 and TAP2 proteins.

Synthesis of NSC 106084 and NSC 14778 and evaluation of their DNMT inhibitory activity.

DNA methylation is an epigenetic modification that is performed by DNA methyltransferases (DNMTs) and that leads to the transfer of a methyl group from S-adenosylmethionine (SAM) to the C5 position of cytosine. This transformation results in hypermethylation and silencing of genes such as tumor suppressor genes. Aberrant DNA methylation has been associated with the development of many diseases, including cancer. Inhibition of DNMTs promotes the demethylation and reactivation of epigenetically silenced genes. NSC 106084 and 14778 have been reported to inhibit DNMTs in the micromolar range. We report herein the synthesis of NSC 106084 and 14778 and the evaluation of their DNMT inhibitory activity. Our results indicate that while commercial NSC 14778 is moderately active against DNMT1, 3A/3L and 3B/3L, resynthesized NSC 14778 is inactive under our assay conditions. Resynthesized 106084 was also found to be inactive.

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid.

The copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid is reported. The procedure operates under simple conditions to afford the corresponding aryl cyclopropyl sulfides in moderate to excellent yields. The reaction tolerates substitution in ortho-, meta- and para-substitution as well as electron-donating and electron-withdrawing groups. The S-cyclopropylation of a thiophenol was also accomplished using potassium cyclopropyl trifluoroborate.

Therapeutic response analysis in dogs with naturally occurring osteoarthritis.

OBJECTIVE: Reporting the rate of positive (+) and negative (-) responders based on an objective outcome measure of pain-related functional disability/lameness in dogs with naturally occurring osteoarthritis (OA), and the relationship between initial lameness severity and the odds of being a (+) responder. STUDY DESIGN: Retrospective analysis of published peer-reviewed clinical trials in dogs with naturally occurring OA. ANIMALS: Dogs (n = 213) with hip and/or stifle afflicted-joints. METHODS: A responder analysis was undertaken using a previously determined cut-off value of ±2.0% of body weight using the peak of vertical force (PVF). Among the selected trials, PVF was acquired under similar conditions. Therapeutic approaches were therapeutic diets, natural health products and nonsteroidal anti-inflammatory drugs. RESULTS: Among dogs receiving a therapeutic approach as described above (n = 121), 62.8% [95% confidence interval, 53.9-70.9] were defined as (+) responders, whereas 11.6% [7.0-18.5] were (-) responders, accounting for a net (+) response rate by 51.2% [42.0-60.4]. In dogs receiving a negative control (n = 92), the net (+) response rate was 1.1% [0.0-5.9]. The number needed to treat was 4, and the effect size 0.7 [0.4-1.0]. The odds ratio of being a (+) responder under the therapeutic approaches was 2.85 [1.57-5.17] (p < 0.001). For every less severe lameness manifested with an increment in PVF by 1% body weight, the chance of being a (+) responder following treatment decreased by 9% (odds ratio 0.91 [0.86-0.97], p = 0.006). CONCLUSION AND CLINICAL RELEVANCE: The rate of (+) responder optimizes decision making for the management of pain-related clinical signs of OA. Evidence-based medicine was further supported by clinical metrics based on an objective outcome measure of pain-related functional disability/lameness. This study also revealed that dogs with a mild lameness are less prone to be improved, emphasizing the need to carefully manage OA dogs in spite of a more subtle affliction.

Synthesis of Highly Functionalized Triarylbismuthines by Functional Group Manipulation and Use in Palladium- and Copper-Catalyzed Arylation Reactions.

Organobismuthines are an attractive class of organometallic reagents that can be accessed from inexpensive and nontoxic bismuth salts. Triarylbismuthines are particularly interesting due to their air and moisture stability and high functional group tolerance. We report herein a detailed study on the preparation of highly functionalized triarylbismuth reagents by triple functional group manipulation and their use in palladium- and copper-catalyzed C-, N-, and O-arylation reactions.

Aza follow-ups to BI 207524, a thumb pocket 1 HCV NS5B polymerase inhibitor. Part 1: Mitigating the genotoxic liability of an aniline metabolite.

A series of heterocyclic aza-analogs of BI 207524 (2), a potent HCV NS5B polymerase thumb pocket 1 inhibitor, was investigated with the goal to reduce the liability associated with the release of a genotoxic aniline metabolite in vivo. Analog 4, containing a 2-aminopyridine aniline isostere that is negative in the Ames test was identified, and was found to provide comparable GT1a/1b potency to 2. Although the cross-species PK profile, poor predicted human liver distribution of analog 4 and allometry principles projected high doses to achieve a strong antiviral response in patients, this work has provided a path forward toward the design of novel thumb pocket 1 NS5B polymerase inhibitors with improved safety profiles.

Multi-parameter optimization of aza-follow-ups to BI 207524, a thumb pocket 1 HCV NS5B polymerase inhibitor. Part 2: Impact of lipophilicity on promiscuity and in vivo toxicity.

We describe our efforts to identify analogs of thumb pocket 1 HCV NS5B inhibitor 1 (aza-analog of BI 207524) with improved plasma to liver partitioning and a predicted human half-life consistent with achieving a strong antiviral effect at a reasonable dose in HCV-infected patients. Compounds 3 and 7 were identified that met these criteria but exhibited off-target promiscuity in an in vitro pharmacology screen and in vivo toxicity in rats. High lipophilicity in this class was found to correlate with increased probability for promiscuous behavior and toxicity. The synthesis of an 8×11 matrix of analogs allowed the identification of C3, an inhibitor that displayed comparable potency to 1, improved partitioning to the liver and reduced lipophilicity. Although C3 displayed reduced propensity for in vitro off-target inhibition and the toxicity profile in rats was improved, the predicted human half-life of this compound was short, resulting in unacceptable dosing requirements to maintain a strong antiviral effect in patients.

Discovery, design, and synthesis of indole-based EZH2 inhibitors.

The discovery and optimization of a series of small molecule EZH2 inhibitors is described. Starting from dimethylpyridone HTS hit (2), a series of indole-based EZH2 inhibitors were identified. Biochemical potency and microsomal stability were optimized during these studies and afforded compound 22. This compound demonstrates nanomolar levels of biochemical potency (IC50=0.002 µM), cellular potency (EC50=0.080 µM), and afforded tumor regression when dosed (200 mpk SC BID) in an EZH2 dependent tumor xenograft model.

Copper-catalyzed O-arylation of N-protected 1,2-aminoalcohols using functionalized trivalent organobismuth reagents.

The O-arylation of 1,2-aminoalcohols using functionalized triarylbismuth reagents is reported. The reaction can be performed using substoichiometric amounts of copper acetate and operates under mild conditions. Good functional group tolerance is observed, giving access to a range of ß-aryloxyamines. The effect provided by the amino group in the arylation reaction is investigated.

Mechanism-Driven Elaboration of an Enantioselective Bromocyclopropanation Reaction of Allylic Alcohols.

A stereoselective bromocyclopropanation of allylic alcohols using dibromomethylzinc bromide is described. Spectroscopic studies to monitor the formation of transient intermediates not only led to the development of a more-atom-economical halocyclopropanation reaction, but also highlighted the unique role of ether additives in the process. The desired bromo-substituted cyclopropanes were isolated in high yields and excellent diastereo- as well as enantioselectivities using readily available reagents.

Synthesis of highly functionalized diaryl ethers by copper-mediated O-arylation of phenols using trivalent arylbismuth reagents.

Highly functionalized diaryl ethers were prepared by copper(II) acetate mediated O-arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N-arylation of pyridones is also reported.

Assessing coastal vulnerability at the village level using a robust framework, the example of Canacona in South Goa, India.

Climate change poses a significant threat to coastal regions worldwide. This study presents and applies a modified Coastal Vulnerability Index (CVI) to assess coastal vulnerability at the village level, focusing on Canacona, a taluka in South Goa, India. It adapts the existing CVI methodology by incorporating additional variables to better represent the various dimensions of vulnerability, resulting in 21 variables split into a Physical Vulnerability Index (PVI) and a Social Vulnerability Index (SoVI). The results show spatial variability in coastal vulnerability across the studied villages, with Agonda and Nagercem-Chaudi found to be highly vulnerable and Loliem to be the least vulnerable. A hydrological modeling approach is also used to compare the CVI of every village with their susceptibility to inundation due to rising sea levels. The results demonstrate the influence of local factors on vulnerability, challenging previous taluka-level assessments given the scale upon which adaptation typically takes place.

Distinct effects of two HIV-1 capsid assembly inhibitor families that bind the same site within the N-terminal domain of the viral CA protein.

The emergence of resistance to existing classes of antiretroviral drugs necessitates finding new HIV-1 targets for drug discovery. The viral capsid (CA) protein represents one such potential new target. CA is sufficient to form mature HIV-1 capsids in vitro, and extensive structure-function and mutational analyses of CA have shown that the proper assembly, morphology, and stability of the mature capsid core are essential for the infectivity of HIV-1 virions. Here we describe the development of an in vitro capsid assembly assay based on the association of CA-NC subunits on immobilized oligonucleotides. This assay was used to screen a compound library, yielding several different families of compounds that inhibited capsid assembly. Optimization of two chemical series, termed the benzodiazepines (BD) and the benzimidazoles (BM), resulted in compounds with potent antiviral activity against wild-type and drug-resistant HIV-1. Nuclear magnetic resonance (NMR) spectroscopic and X-ray crystallographic analyses showed that both series of inhibitors bound to the N-terminal domain of CA. These inhibitors induce the formation of a pocket that overlaps with the binding site for the previously reported CAP inhibitors but is expanded significantly by these new, more potent CA inhibitors. Virus release and electron microscopic (EM) studies showed that the BD compounds prevented virion release, whereas the BM compounds inhibited the formation of the mature capsid. Passage of virus in the presence of the inhibitors selected for resistance mutations that mapped to highly conserved residues surrounding the inhibitor binding pocket, but also to the C-terminal domain of CA. The resistance mutations selected by the two series differed, consistent with differences in their interactions within the pocket, and most also impaired virus replicative capacity. Resistance mutations had two modes of action, either directly impacting inhibitor binding affinity or apparently increasing the overall stability of the viral capsid without affecting inhibitor binding. These studies demonstrate that CA is a viable antiviral target and demonstrate that inhibitors that bind within the same site on CA can have distinct binding modes and mechanisms of action.