Desirable Pharmacokinetic Properties Research Articles

Discovery of N-Phenyl-4-(1H-pyrrol-3-yl)pyrimidin-2-amine Derivatives as Potent Mnk2 Inhibitors: Design, Synthesis, SAR Analysis, and Evaluation of in vitro Anti-leukaemic Activity.

Aberrant expression of eukaryotic translation initiation factor 4E (eIF4E) is common in many types of cancer including acute myeloid leukaemia (AML). Phosphorylation of eIF4E by MAPK-interacting kinases (Mnks) is essential for the eIF4E-mediated oncogenic activity. As such, the pharmacological inhibition of Mnks can be an effective strategy for the treatment of cancer. A series of N-phenyl-4-(1H-pyrrol-3-yl)pyrimidin-2-amine derivatives was designed and synthesised. The Mnk inhibitory activity of these derivatives as well as their anti-proliferative activity against MV4-11 AML cells was determined. These compounds were identified as potent Mnk2 inhibitors. Most of them demonstrated potent anti-proliferative activity against MV4-11 AML cells. The cellular mechanistic studies of the representative inhibitors revealed that they reduced the level of phosphorylated eIF4E and induced apoptosis by down-regulating the anti-apoptotic protein myeloid cell leukaemia 1 (Mcl-1) and by cleaving poly(ADP-ribose)polymerase (PARP). The lead compound 7k possessed desirable pharmacokinetic properties and oral bioavailability. This work proposes that exploration of the structural diversity in the context of Nphenyl- 4-(1H-pyrrol-3-yl)pyrimidin-2-amine would offer potent and selective Mnk inhibitors.

Homology modeling and in silico toxicity assessment of potential inhibitors of cytidylate kinase from Mycobacterium tuberculosis

Cytidylate kinase (CMK) plays a central role in the phosphorylation of ATP to nucleoside diphosphates in the purine and pyrimidine pathway in Mycobacterium tuberculosis (MTB). The enzyme is specific to bacteria, fungi, and plants and it shares the same pathway with a DNA-directed RNA polymerase subunit beta, the known target of rifampicin (RIF). Therefore, it serves as an attractive alternative target to inhibit the purine and pyrimidine pathway in MTB. In this study, the novel inhibitors of CMK were identified using in silico approach. Homology modeling was used to build the three-dimensional (3D) structure of CMK using program implemented in Modeller 9.16 and based on the template (3R20) obtained from Mycobacterium smegmatis. Structural analysis of CMK showed that it has P-loop or core in the ATP binding domain, nucleoside monophosphate binding (NMP) site, and a LID domain. Inhibition of any of the residues that formed the nucleoside binding site or ATP binding site blocks the catalytic activity of the CMK. Eleven thousand four hundred and fifty-four compounds that had an affinity to bind to the CMK with minimum binding energies were obtained through virtual screening from Zinc and PubChem databases using PyRx 8.0. These compounds were further filtered for Lipinski rule of five, molecular docking analysis, and ADMET properties (absorption distribution, metabolism, excretion, and toxicity). Four compounds (ZINC95485891 = − 8.80 kcal/mol, ZINC95485880 = − 8.44 kcal/mol, ZINC95485900 = − 8.24 kcal/mol, and ZINC95486231 = − 8.20 kcal/mol) with good binding energies and desirable pharmacokinetic properties were selected. These compounds were further subjected to molecular dynamic (MD) simulation and molecular mechanics generalized Born and surface area (MM-GBSA) analyses. The results of the analyses showed that all the four ligands formed a stable complex and had good free binding energy after 50 ns MD simulation. Therefore, these compounds were considered as possible inhibitors of MTB after experimental validation.

1151-P: Dorzagliatin Differentiates from Early Generation of Glucokinase Activators: An Enzyme Kinetics Study

Over the last two decades, many glucokinase activators (GKAs) advanced into clinical studies but failed to achieve proof of concept as antidiabetics until the most recent success of Dorzagliatin (a.k.a. HMS5552). Desirable pharmacokinetic (PK) and pharmacodynamic (PD) properties of Dorzagliatin in human subjects offer clear advantage over many GKAs previously in clinical trial. Dorzagliatin benefits also from its desirable enzyme kinetic properties that improve GK’s glucose sensor function and restore glucose homeostasis. Herein we report our recent results on 5 GKAs which all advanced into Phase II clinical studies, some suffered hypoglycemia and others lacked durable efficacy in T2D patients. We evaluated key parameters in GK activation that include α, β and nH in nonessential-mixed type enzyme kinetics equation, as well as the changes under various glucose and drug concentrations. Here β represents the change in Vmax and associates with the ability of GKA to restore GK’s glucose sensor function. Partial GKAs such as AZD1656 and PF-04937319 showed β<1 and were less effective in blood glucose control. In contrast, Piragliatin and Dorzagliatin showed β value of 1.74 and 1.40 respectively, both demonstrated sustained and significant HbA1c reduction. Changes of nH result in alteration of GK’s glucose dependence and the degree of changes in nH is dependent on GKA concentration. Significant changes in nH by MK-0941 (nH = 1.21 at 10 μM GKA vs. 1.86 without GKA) correlate with its hypoglycemia risk in T2D subjects as shown in clinical trials. Our results strongly indicate that % change in nH at 10 uM GKA shall not go beyond 20% compared with drug free state. Lastly, α values for 5 GKAs all seem to fall in the range of 0.005 to 0.016, thus not appear to correlate with the behavior in clinical trials. The current study provides valuable insight to elucidate some key properties contributing to successful development of a GKA that repairs the glucose sensor function and remodels homeostasis. Disclosure L. Chen: Employee; Self; Hua Medicine. Y. Shan: None. X. Jin: None. X. Lv: None.

Design, synthesis, and evaluation of isoflavone analogs as multifunctional agents for the treatment of Alzheimer's disease

A series of novel isoflavone analogs were designed, synthesized, and evaluated as multitarget-directed ligands for the treatment of Alzheimer's disease. In vitro evaluations revealed that some ligands had multifunctional profiles, including potent blockage of histamine 3 receptor (H3R), excellent inhibition of acetylcholinesterase (AChE), neuroprotective effects and anti-neuroinflammatory properties. Among these derivatives, compound 9b exhibited the highest ability to block H3R (IC50 = 0.27 μM) and good inhibitory activity against AChE (IC50 = 0.08 μM). Additionally, compound 9b showed obvious neuroprotective effect on SH-SY5Y by preventing copper-induced neuronal damage and potent anti-neuroinflammatory activity by inhibiting the production of inflammatory factors on BV-2 cells. A molecular modeling study revealed that 9b acts as a mixed-type inhibitor that interacts simultaneously with H3R and AChE. Moreover, in vivo data revealed that compound 9b did not cause acute toxicity in mice at doses up to 1000 mg/kg, and had desirable pharmacokinetic properties, as well as a good blood-brain barrier (BBB) permeability (log BB = 1.24 ± 0.07). Further studies demonstrated that chronic oral treatment with 9b significantly improved cognitive dysfunction in scopolamine-induced AD mice in the step-down passive avoidance test. Taken together, the present study showed that compound 9b is a promising multifunctional drug candidate for the treatment of Alzheimer's disease.

Humanin Nanoparticles for Reducing Pathological Factors Characteristic of Age-Related Macular Degeneration.

Humanin is a novel neuronal peptide that has displayed potential in the treatment of Alzheimer's Disease through the suppression of inflammatory IL-6 cytokine receptors. Such receptors are found throughout the body, including the eye, suggesting its other potential applications. Age-related Macular Degeneration (AMD) is the leading cause of blindness in the developing world. There is no cure for this disease, and current treatments have several negative side effects associated with them, making finding other treatment options desirable. In this study, the potential applications in treating AMD for a more potent humanin derivative, AGA-HNG, were studied. AGA-HNG was synthesized and encapsulated in chitosan Nanoparticles (NPs), which were then characterized for their size, Encapsulation Efficiency (EE), and drug release. Their ability to suppress VEGF secretion and protect against oxidative apoptosis was studied in vitro using ARPE-19 cells. The chitosan NPs exhibited similar anti-VEGF properties and oxidative protection as the free protein while exhibiting superior pharmaceutical characteristics including biocompatibility and drug release. Drug-loaded NPs exhibited a radius of 346nm with desirable pharmacokinetic properties including a stable surface charge (19.5 ± 3.7 mV) and steady drug release capacity. AGA-HNG showed great promise in mediating apoptosis in hypoxic cells. They were also able to significantly reduce VEGF expression in vitro with reduced cellular toxicity compared to the free drug. The ability of this drug delivery system to reduce retinal apoptosis with desirable pharmacokinetic and biocompatible properties makes this a promising therapeutic option for AMD.

The Difluoromethyl Group as a Masked Nucleophile: A Lewis Acid/Base Approach.

The difluoromethyl group (R-CF2H) imparts desirable pharmacokinetic properties to drug molecules and is commonly targeted as a terminal functional group that is not amenable to further modification. Deprotonation of widely available Ar-CF2H starting materials to expose nucleophilic Ar-CF2- synthons represents an unexplored, yet promising route to construct benzylic Ar-CF2-R linkages. Here we show that the combination of a Brønsted superbase with a weak Lewis acid enables deprotonation of Ar-CF2H groups and capture of reactive Ar-CF2- fragments. This route provides access to isolable and reactive Ar-CF2- synthons that react with a broad array of electrophiles at room temperature. The methodology is highly general in both electrophile and difluoromethyl (hetero)arene and can be applied directly to the synthesis of benzylic difluoromethylene (Ar-CF2-R) linkages, which are useful lipophilic and metabolically resistant replacements for benzylic linkages in medicinal chemistry.

Identification of biological activities of Abutilon indicum fruit by in silico and in vitro approach

Abutilon indicum is a plant that belongs to the Malvaceae family, which is distributed throughout a number of tropical and subtropical areas and has been used for various disorders in traditional and folk medicine. The various medicinal applications of this plant include anti-inflammatory, antioxidant, demulcent, aphrodisiac, laxative, diuretic, pulmonary and sedative. Thus the present study was formed to identify the biological activities of A. indicum fruit by in silico and in vivo approach. The ethanolic extract was prepared and screened for in vitro antimicrobial activities against Staphylococcus aureus and Enterococcus faecalis and also against a fungi Aspergillus niger. The ethanolic extract was subjected to Gas chromatography–mass spectrometry (GC-MS) analysis for identification of compounds present in fruit sample. The identified compounds were then screened for anti-inflammatory activity by molecular docking against the Cyclooxygenase-2 inhibitors. Also, Density Functional Theory (DFT) & Absorption Distribution Metabolism Excretion and Toxicity (ADMET) studies were carried out to assess the quantum-chemical parameters and pharmacokinetics behaviour respectively. The ethanolic fruit extract of A. indicum showed moderate antimicrobial activity against S. aureus, E. faecalis and Aspergillus niger at the MIC of 25 μg/μl. AI 1003, AI 1004 and AI 1005 were identified as lead compounds against the target Cyclooxygenase −2 which exhibited strong hydrogen bond interaction & also desirable pharmacokinetic properties. DFT studies also showed the promising reactivity with lowest energy gap of compounds AI 1004 &AI 1005. Thus, owing to the significant interaction of the compounds with the target COX-2 and desirable pharmacokinetic properties of compounds of ethanolic extract of A. indicum could be further explored for anti-inflammatory properties by in vitro &in vivo analysis.

Using antibody directed phototherapy to target oesophageal adenocarcinoma with heterogeneous HER2 expression.

Early oesophageal adenocarcinoma (OA) and pre-neoplastic dysplasia may be treated with endoscopic resection and ablative techniques such as photodynamic therapy (PDT). Though effective, discrete areas of disease may be missed leading to recurrence. PDT further suffers from the side effects of off-target photosensitivity. A tumour specific and light targeted therapeutic agent with optimised pharmacokinetics could be used to destroy residual cancerous cells left behind after resection. A small molecule antibody-photosensitizer conjugate was developed targeting human epidermal growth factor receptor 2 (HER2). This was tested in an in vivo mouse model of human OA using a xenograft flank model with clinically relevant low level HER2 expression and heterogeneity. In vitro we demonstrate selective binding of the conjugate to tumour versus normal tissue. Light dependent cytotoxicity of the phototherapy agent in vitro was observed. In an in vivo OA mouse xenograft model the phototherapy agent had desirable pharmacokinetic properties for tumour uptake and blood clearance time. PDT treatment caused tumour growth arrest in all the tumours despite the tumours having a clinically defined low/negative HER2 expression level. This new phototherapy agent shows therapeutic potential for treatment of both HER2 positive and borderline/negative OA.

In silico ADME in drug design – enhancing the impact

<p>Each year the pharmaceutical industry makes thousands of compounds, many of which do not meet the desired efficacy or pharmacokinetic properties, describing the absorption, distribution, metabolism and excretion (ADME) behavior. Parameters such as lipophilicity, solubility and metabolic stability can be measured in high throughput in vitro assays. However, a compound needs to be synthesized in order to be tested. In silico models for these endpoints exist, although with varying quality. Such models can be used before synthesis and, together with a potency estimation, influence the decision to make a compound. In practice, it appears that often only one or two predicted properties are considered prior to synthesis, usually including a prediction of lipophilicity. While it is important to use all information when deciding which compound to make, it is somewhat challenging to combine multiple predictions unambiguously. This work investigates the possibility of combining in silico ADME predictions to define the minimum required potency for a specified human dose with sufficient confidence. Using a set of drug discovery compounds,in silico predictions were utilized to compare the relative ranking based on minimum potency calculation with the outcomes from the selection of lead compounds. The approach was also tested on a set of marketed drugs and the influence of the input parameters investigated.</p>

Fusion Inhibitory Lipopeptides Engineered for Prophylaxis of Nipah Virus in Primates.

The emerging zoonotic paramyxovirus Nipah virus (NiV) causes severe respiratory and neurological disease in humans, with high fatality rates. Nipah virus can be transmitted via person-to-person contact, posing a high risk for epidemic outbreaks. However, a broadly applicable approach for human NiV outbreaks in field settings is lacking. We engineered new antiviral lipopeptides and analyzed in vitro fusion inhibition to identify an optimal candidate for prophylaxis of NiV infection in the lower respiratory tract, and we assessed antiviral efficiency in 2 different animal models. We show that lethal NiV infection can be prevented with lipopeptides delivered via the respiratory route in both hamsters and nonhuman primates. By targeting retention of peptides for NiV prophylaxis in the respiratory tract, we avoid its systemic delivery in individuals who need only prevention, and thus we increase the safety of treatment and enhance utility of the intervention. The experiments provide a proof of concept for the use of antifusion lipopeptides for prophylaxis of lethal NiV. These results advance the goal of rational development of potent lipopeptide inhibitors with desirable pharmacokinetic and biodistribution properties and a safe effective delivery method to target NiV and other pathogenic viruses.

Molecular docking and density function theory studies of compounds from Euphorbia hirta and Bacopa monnieri to zika virus structural and nonstructural proteins

Background: Zika virus is an arbovirus belongs to the genus flavivirus and pose a serious global threat. The recent 2015 outbreak in Brazil was associated with a significant increase in microcephaly cases and other neurological complications in newborn babies and WHO declared Zika to be an international public health emergency. Currently, there is no specific treatment or Vaccine available for the Zika virus, and thus due to the unavailability of the antiviral drugs, the need for the identification of novel drugs is paramount. Materials and Methods: The compounds from two medicinal plants (Bacopa monnieri and Euphorbia hirta) were selected for the in silico molecular docking studies against the structural and nonstructural proteins of Zika virus. Quantum–chemical parameters density functional theory and absorption, distribution, metabolism, and excretion-toxicity (ADMET) was performed to identify the drug-likeliness properties. Results: Among the tested compounds, galloylquinic acid, Bacopaside III, and Bacopaside A were identified as leads against multiple targets of Zika virus. The identified compounds also exhibited desirable quantum chemical and ADMET properties. Conclusion: Hence, the compounds hampering the active site of the three different proteins playing a prime role in replication and fusion with desirable pharmacokinetic properties could be suggested for further in vitro and in vivo analysis of Zika virus. Abbreviations used: WHO: World Health Organization; DFT: Density function theory; ADMET: Absorption, distribution, metabolism, and excretion-toxicity; HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus; HSV: Herpes simplex virus; PDB: Protein data bank; OPLS: Optimized potential for liquid simulations; RMSD: Root-mean-square deviation; IFD XP: Induced fit docking extra precision; XP: Extra precision; PSA: Polar surface area; BBB: Blood brain barrier; A LogP 98: Atom-based Log P98; HOMO: Highest occupied molecular orbital; LUMO: Lowest unoccupied molecular orbital; DS V 4.0: Discovery Studio version 4.0; NS3: Nonstructural protein 3; NS1: Nonstructural protein 1

Session One: Basal Insulins: Still Innovating After All These Years

Therapeutic basal insulin has evolved considerably over the past 90 years. A series of landmark innovations has led to the availability of therapies that closely mimic the physiological effects of endogenous insulin and serve as an invaluable addition to the treatment armamentarium for diabetes. Advances in basal insulin have led to the development of the newer basal insulin analogues, namely insulin degludec and insulin glargine 300 U/mL (Gla-300). The desirable pharmacokinetic (PK) and pharmacodynamic (PD) properties of these basal insulins, such as a prolonged duration of action (≥24 hours), may translate into a number of clinical benefits for the patient e.g., a simple, once-daily injection schedule and flexible injection timings. The technologies supporting patients with diabetes have also evolved considerably in recent years. Continuous glucose monitoring (CGM) can provide insights into some of the challenges faced by patients with diabetes, e.g., glycaemic excursions and the impact of injection time, and may become an alternative to the current gold standard glycated haemoglobin (HbA1c). Real-world evidence is also providing fresh perspectives on the effectiveness of basal insulins in clinical practice. Today, innovative methods for real-world evidence collection, analysis, and interpretation are helping to generate robust datasets with external validity. Taken together, these innovative approaches are generating an integrated evidence base that is improving our understanding of how basal insulin therapy can be optimised for the benefit of our patients with diabetes.

Tissue transport affects how treatment scheduling increases the efficacy of chemotherapeutic drugs

A method to predict the effect of tissue transport on the scheduling of chemotherapeutic treatment could increase efficacy. Many drugs with desirable pharmacokinetic properties fail in vivo due to poor transport through tissue. To predict the effect of treatment schedule on drug efficacy we developed an in silico method that integrates diffusion through tissue and cell binding into a pharmacokinetic model. The model was evaluated with an array of theoretical drugs that had different rates of diffusivity, binding, and clearance. The efficacy of each drug, quantified as the fraction of cells killed, was calculated for twenty dosage schedules. Simulations showed that efficacy strongly depended on tissue transport, with a range of 0.00 to 99.99%, despite each drug having equal plasma areas under the curve (AUC). For most drugs, schedules that increased exposure also increased efficacy. Drugs with fast clearance benefited the most from increasing the number of doses and this was most effective for those with intermediary binding. All drugs with slow diffusivity were ineffective. For a subset of drugs, increasing the number of doses decreased efficacy. This phenomenon was unexpected because, when considering uptake into tissue, sustained plasma levels from multiple doses are generally assumed to be more effective. This counterintuitive decrease in efficacy was caused by drug retention within tumor tissue. These results established a set of rules that suggests how transport parameters affect the efficacy of drugs at different schedules. The two most predominant rules are (1) multiple doses improve efficacy for drugs with fast clearance, fast diffusivity and low to intermediate cell binding; and (2) one dose is most effective for drugs with slow clearance, slow diffusivity or strong cell binding. Understanding the role of tissue transport when determining drug treatment schedules would improve the outcome of preclinical animal experiments and early clinical trials.

In vitro, In silico and In vivo Antitumor Activity of Crude Methanolic Extract of Tetilla dactyloidea (Carter, 1869) on DEN Induced HCC in a Rat Model

Tetilla dactyloidea (Carter, 1869) is a marine sponge classified under Demospongia and recent studies have demonstrated that active constituents of Demospongia class have exhibited several potential medical applications. However, no preliminary pharmacological studies have been reported so far. The present investigation was carried out to evaluate the zoo-chemical status, antioxidant potential and anticancer activity of Crude Methanolic Extract of Tetilla dactyloidea (CMETD). Hepatocellular Carcinoma (HCC) was induced in the liver of male Sprague Dawley (SD) rats by treating with diethylnitrosamine (DEN). Nodule incidence, body weight, liver marker enzymes, enzymatic and non-enzymatic antioxidant, phase I metabolizing and liver macromolecular damaging enzymes and immuno-histopathological changes were assessed in DEN and DEN+CMETD treated rats. Oral administration of CMETD at a dose of 400mg/kg body weight to DEN treated rats restored the above parameters to near normal levels compared to control. The biochemical results were consistent with histopathological observations suggesting marked hepatoprotective effect of CMETD in a dose dependent manner. The GCMS of CMETD analysis showed the presence of six compounds. In in silico analysis 9-Octadecenoic acid (Z)-, 2-hydroxy-1-(hydroxymethyl) ethyl ester ligand showed an effective binding energy of −7.1kcal/mol against Cox-2 receptor. The compounds showed desirable pharmacokinetic properties and significant molecular interactions with the HCC receptors. To conclude, our results clearly suggested that CMETD treatment prevented liver damage, protected the antioxidant defense system and possessed anti-carcinogenic potential in DEN induced hepatic carcinoma.

Synthesis and evaluation of haloperidol metabolite II prodrugs as anticancer agents.

The use of haloperidol metabolite II (HP-metabolite II) prodrugs is an emerging strategy in the treatment of cancer. HP-metabolite II exhibits antiproliferative properties at micromolar concentrations inducing apoptosis in different types of cancer. Thus, the application of the prodrug approach appears as a useful method leading to much more desirable pharmacokinetic and pharmacodynamic properties. Some studies have shown that the esterification of the hydroxyl group of HP-metabolite II with 4-phenylbutiric acid (4-PBA) or valproic acid enhances the anticancer therapeutic potency. The current progresses in the design, synthesis and evaluation of anticancer activity of HP metabolite II prodrugs will be discussed in this review.

In vitro characterisation of solid drug nanoparticle compositions of efavirenz in a brain endothelium cell line

AbstractThe antiretroviral drug efavirenz displays many desirable pharmacokinetic properties such as a long half‐life enabling once daily dosing but suffers from central nervous system safety issues. Various nanotechnologies have been explored to mitigate some of the limitations with efavirenz. While there has been progress in increasing the bioavailability, there has been no attempt to assess the impact of increased exposure to efavirenz on central nervous system safety. The uptake of aqueous and solid drug nanoparticle (SDN) formulations of efavirenz was assessed in the human cerebral microvessel endothelial cells/D3 brain endothelial cell line. The mechanisms of uptake were probed using a panel of transport and endocytosis inhibitors. The cellular accumulation of an efavirenz aqueous solution was significantly reduced by amantadine, but this was not observed with SDNs. The uptake of efavirenz SDNs was reduced by dynasore, but concentrations of the efavirenz aqueous solution were not affected. These data indicate that efavirenz is a substrate for transporters in brain endothelial cells (amantadine is an inhibitor of organic cation transporters 1 and 2), and formation of SDNs may bypass this interaction in favour of a mechanism involving dynamin‐mediated endocytosis.

Abstract 5088: Tumor penetrating RNA delivery for therapeutic benefit of pancreatic cancer

Abstract Pancreatic cancer remains a deadly disease with a median survival of less than one year, in part because we lack effective therapeutic strategies. Mutations of the oncogene KRAS and the tumor suppressor genes TP53, INK4A, and DPC4 play important roles in the pathogenesis of pancreatic ductal adenocarcinoma (PDAC); however, these driver events have proven to be challenging targets for drug development. RNA interference through small interfering RNA (siRNA) delivery has the potential to have an impact on silencing ‘undruggable’ targets; however, siRNA delivery in tumors has been challenging in general and worsened in PDAC by the stromal barriers to drug delivery. Herein, we integrated biomedical engineering, materials science, and pre-clinical investigation to establish a novel class of tumor-penetrating nanoparticles (TPNs) to enhance delivery of siRNAs in PDAC for therapeutic benefit. Specifically, we adapted self-assembled nanoparticles comprised of siRNA complexed with tandem tumor-penetrating and membrane-translocating peptides, which enabled the specific delivery of siRNA deep into the tumor parenchyma. Specifically, to establish efficacious siRNA delivery vehicles, we characterized and selected tandem peptides that incorporate novel tumor-penetrating peptide domains known to target PDAC in mice. In parallel, we optimized the particle stability through incorporation of hydrophilic molecules, focusing on achieving desirable pharmacokinetic properties which will reduce off-target delivery and increase potency of a given siRNA dose. The resulting TPNs carry siRNA into the cytosol of monolayer cultures of tumor cells, and also exhibit penetration in pancreas organoids derived from primary mouse and human tumors. As a proof-of-concept, we used TPN in vivo to knockdown KRAS in a murine PDAC model, using subcutaneously-implanted, autochthonous KRASG12D/+p53-/- tumors. Treatment of tumor-bearing mice with systemically administrated KRAS-specific TPNs suppressed the growth of established tumors. With the delivery platform established, the ongoing goals of this project are to identify siRNA targets that synergize with the suppression of oncogenic KRAS, and to validate synthetic lethal targets by interfering with signature PDAC driver events uncovered by functional genomic efforts. Together, these studies will provide a foundation for translational studies involving new targets and delivery technology in pancreatic cancer. Citation Format: Liangliang Hao, Justin Lo, Sangeeta Bhatia. Tumor penetrating RNA delivery for therapeutic benefit of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5088. doi:10.1158/1538-7445.AM2017-5088

Resveratrol and Its Analogues – Is It a New Strategy of Anticancer Therapy?

Summary Resveratrol (RSV) is one of the polyphenols - metabolites common in plants,however it does not occur in animals. It occurs mainly in grape skin (Vitisvinifera), peanuts (Arachis hypogeal) and in the roots of (Polygonumcupidatum) a traditional Chinese curative plant. RSV has a preventive property against the most serious diseases of modern world such as cancer, neurodegenerative diseases and cardiovascular diseases. Due to pleiotropy, RSV is currently the main object of many research teams′ interest, which is shown by the significant number of publications devoted to this subject. Animal and human conducted studies have shown very low bioavailability of RSV (approx. 2%), which is the result of rapid biotransformation to sulphate and to a lesser extent, to the glucuronide conjugates as well. The studies on the improvement of RSV bioavailability, which have beencarried out for many years, have contributed to the synthesis of the analogues of more chemopreventive and more desirable pharmacokinetic properties. In order to enhance antiproliferative activity and RSV bioavailability, series of methyl analogues were synthesized and this will be described later in more detail. An example of such a derivative is DMU-212 (3,4,4’5-tetramethoxystilbene).

Spectral characterisation, antiviral activities, in silico ADMET and molecular docking of the compounds isolated from Tectona grandis to chikungunya virus.

Chikungunya infection is treated symptomatically with antipyretics and anti-inflammatory drugs without any specific antiviral drug till date. The lack of an approved antiviral drug and the emergence of virulent strains after 2006 epidemics emphasize the need for the development of potential antiviral drugs to Chikungunya virus. Hence, we studied the antiviral activity of the extracts and compounds isolated from Tectona grandis leaves to both the Asian and East central South African strains of Chikungunya virus. Five compounds were isolated from the ethanolic extract of Tectona grandis by bioactivity guided fractionation followed by Spectral Characterisation through GC-MS and NMR spectroscopy and investigated for the antiviral activity. Also in silico ADMET and Molecular Docking of the characterised compounds against the structural and non structural proteins of Chikungunya virus were performed. The characterised compound Benzene-1-carboxylic acid hexadeconate was effective at IC 50 3.036μg/ml (7.5μM) and 76.46μg/ml (189.02μM) to Asian and ECSA strain of CHIKV respectively. The compound showed desirable pharmacokinetic properties and significant molecular interactions with the E1 protein of Chikungunya virus by in silico analysis. Thus Benzene-1-carboxylic acid-2-hexadeconate isolated from Tectona grandis was found to be a promising drug candidate to both the Asian and ECSA strains of Chikungunya virus with high selectivity indices in comparison to the reference RNA antiviral drug Ribavirin.

Novel p21-Activated Kinase 4 (PAK4) Allosteric Modulators Overcome Drug Resistance and Stemness in Pancreatic Ductal Adenocarcinoma.

The p21-activated kinase 4 (PAK4) is a key downstream effector of the Rho family GTPases and is found to be overexpressed in pancreatic ductal adenocarcinoma (PDAC) cells but not in normal human pancreatic ductal epithelia (HPDE). Gene copy number amplification studies in PDAC patient cohorts confirmed PAK4 amplification making it an attractive therapeutic target in PDAC. We investigated the antitumor activity of novel PAK4 allosteric modulators (PAM) on a panel of PDAC cell lines and chemotherapy-resistant flow-sorted PDAC cancer stem cells (CSC). The toxicity and efficacy of PAMs were evaluated in multiple subcutaneous mouse models of PDAC. PAMs (KPT-7523, KPT-7189, KPT-8752, KPT-9307, and KPT-9274) show antiproliferative activity in vitro against different PDAC cell lines while sparing normal HPDE. Cell growth inhibition was concurrent with apoptosis induction and suppression of colony formation in PDAC. PAMs inhibited proliferation and antiapoptotic signals downstream of PAK4. Co-immunoprecipitation experiments showed disruption of PAK4 complexes containing vimentin. PAMs disrupted CSC spheroid formation through suppression of PAK4. Moreover, PAMs synergize with gemcitabine and oxaliplatin in vitro KPT-9274, currently in a phase I clinical trial (clinicaltrials.gov; NCT02702492), possesses desirable pharmacokinetic properties and is well tolerated in mice with the absence of any signs of toxicity when 200 mg/kg daily is administered either intravenously or orally. KPT-9274 as a single agent showed remarkable antitumor activity in subcutaneous xenograft models of PDAC cell lines and CSCs. These proof-of-concept studies demonstrated the antiproliferative effects of novel PAMs in PDAC and warrant further clinical investigations. Mol Cancer Ther; 16(1); 76-87. ©2016 AACR.