Beyond MABEL: An Integrative Approach to First in Human Dose Selection of Immunomodulators by the Health and Environmental Sciences Institute (HESI) Immuno-Safety Technical Committee (ITC).

Administration of a new drug candidate in a first-in-human (FIH) clinical trial is a particularly challenging phase in drug development and is especially true for immunomodulators, which are a diverse and complex class of drugs with a broad range of mechanisms of action and associated safety risks. Risk is generally greater for immunostimulators, in which safety concerns are associated with acute toxicity, compared to immunosuppressors, where the risks are related to chronic effects. Current methodologies for FIH dose selection for immunostimulators are focused primarily on identifying the minimum anticipated biological effect level (MABEL), which has often resulted in sub-therapeutic doses, leading to long and costly escalation phases. The Health and Environmental Sciences Institute (HESI) - Immuno-Safety Technical Committee (ITC) organized a project to address this issue through two complementary approaches: (i) an industry survey on FIH dose selection strategies and (ii) detailed case studies for immunomodulators in oncology and non-oncology indications. Key messages from the industry survey responses highlighted a preference toward more dynamic PK/PD approaches as in vitro assays are seemingly not representative of true physiological conditions for immunomodulators. These principles are highlighted in case studies. To address the above themes, we have proposed a revised decision tree, which expands on the guidance by the IQ MABEL Working Group (Leach et al. 2021). This approach facilitates a more refined recommendation of FIH dose selection for immunomodulators, allowing for a nuanced consideration of their mechanisms of action (MOAs) and the associated risk-to-benefit ratio, among other factors.

Enhancement of innate immunity in gingival epithelial cells by vitamin D and HDAC inhibitors.

Introduction: The human host defense peptide LL-37 is a component of the innate immune defense mechanisms of the oral cavity against colonization by microbes associated with periodontal disease. We have previously shown that the active form of vitamin D, 1,25(OH)2D3, can induce the expression of LL-37 in gingival epithelial cells (GEC), and prevent the invasion and growth of periopathogenic bacteria in these cells. Further, experimental vitamin D deficiency resulted in increased gingival inflammation and alveolar bone loss. Epidemiological studies have shown associations between vitamin D deficiency and periodontal disease in humans, suggesting application of vitamin D could be a useful therapeutic approach. Further, since we have shown the local activation of vitamin D by enzymes expressed in the GEC, we hypothesized that we could observe this enhancement with the stable, and inexpensive inactive form of vitamin D, which could be further increased with epigenetic regulators. Methods: We treated 3-dimensional primary cultures of GEC topically with the inactive form of vitamin D, in the presence and absence of selected histone deacetylase (HDAC) inhibitors. LL-37 mRNA levels were quantified by quantitative RT-PCR, and inhibition of invasion of bacteria was measured by fluorescence microscopy. Results: Vitamin D treatment led to an induction of LL-37 mRNA levels, as well as an inhibition of pro-inflammatory cytokine secretion. This effect was further enhanced by HDAC inhibitors, most strongly when the HDAC inhibitor, phenyl butyrate (PBA) was combined with Vitamin D3. This was observed both in solution and in a prototype gel formulation using sodium butyrate. Finally, this combination treatment led to an increase in the antimicrobial activity against infection by Porphyromonas gingivalis and Filifactor alocis, bacteria associated with periodontal lesions, as well as herpes simplex virus, which has also been shown to be associated with periodontal lesions. Conclusions: Our results demonstrate that a combination of inactive vitamin D and sodium butyrate could be developed as a safe treatment for periodontal disease.

Thiolutin has complex effects in vivo but is a direct inhibitor of RNA polymerase II in vitro.

Thiolutin is a natural product transcription inhibitor with an unresolved mode of action. Thiolutin and the related dithiolopyrrolone holomycin chelate Zn2+ and previous studies have concluded that RNA Polymerase II (Pol II) inhibition in vivo is indirect. Here, we present chemicogenetic and biochemical approaches to investigate thiolutin's mode of action in Saccharomyces cerevisiae. We identify mutants that alter sensitivity to thiolutin. We provide genetic evidence that thiolutin causes oxidation of thioredoxins in vivo and that thiolutin both induces oxidative stress and interacts functionally with multiple metals including Mn2+ and Cu2+, and not just Zn2+. Finally, we show direct inhibition of RNA polymerase II (Pol II) transcription initiation by thiolutin in vitro in support of classical studies that thiolutin can directly inhibit transcription in vitro. Inhibition requires both Mn2+ and appropriate reduction of thiolutin as excess DTT abrogates its effects. Pause prone, defective elongation can be observed in vitro if inhibition is bypassed. Thiolutin effects on Pol II occupancy in vivo are widespread but major effects are consistent with prior observations for Tor pathway inhibition and stress induction, suggesting that thiolutin use in vivo should be restricted to studies on its modes of action and not as an experimental tool.

Fair and equitable AI in biomedical research and healthcare: Social science perspectives.

Artificial intelligence (AI) offers opportunities but also challenges for biomedical research and healthcare. This position paper shares the results of the international conference "Fair medicine and AI" (online 3-5 March 2021). Scholars from science and technology studies (STS), gender studies, and ethics of science and technology formulated opportunities, challenges, and research and development desiderata for AI in healthcare. AI systems and solutions, which are being rapidly developed and applied, may have undesirable and unintended consequences including the risk of perpetuating health inequalities for marginalized groups. Socially robust development and implications of AI in healthcare require urgent investigation. There is a particular dearth of studies in human-AI interaction and how this may best be configured to dependably deliver safe, effective and equitable healthcare. To address these challenges, we need to establish diverse and interdisciplinary teams equipped to develop and apply medical AI in a fair, accountable and transparent manner. We formulate the importance of including social science perspectives in the development of intersectionally beneficent and equitable AI for biomedical research and healthcare, in part by strengthening AI health evaluation.

Formulation and evaluation of solid lipid nanoparticles loaded with papaya seed chloroform extract for long-term antifertility effects on the male rat, Bandicota bengalensis.

The study is the first to formulate and investigate potential of papaya seed chloroform extract based solid lipid nanoparticles (PSCEN) as antifertility agents on male Bandicota bengalensis. The prepared nanoparticles were spherical of size 300-600 nm. The release kinetics showed a controlled release of the drug with major release over 48 h. To assess the antifertility effects of PSCEN, adult male rats were fed a diet containing two different concentrations of PSCEN (5% and 10%) for 15 days under bi-choice conditions. The mean total active ingredient ingestion of the rats in the two treated groups ranged from 2.13-3.31 and 3.92-5.87 g/100g body weight, respectively. No adverse effects of treatment on body weight were observed. Also, no mortality of rats was observed. The treatment had a significant effect on the weight of the testis and the epididymis, but not on the other organs. Sperm motility (%), sperm viability (%), sperm count (millions/ml), sperm mitochondrial activity (%), sperm nuclear chromatin de-condensation (%) and sperm hypo-osmotic swelling (%) were significantly decreased, and sperm abnormality (%) significantly increased compared to the vehicle control group. The reproductive success rates of male rats treated with 5% and 10% PSCEN and mated with untreated female rats were 20.00-66.67% and 16.67%, respectively, while in untreated female rats mated with male rats of vehicle control group, reproductive success rate was 33.33 to 80%. The study found a maximal antifertility effect of the 10% PSCEN containing bait, which was irreversible up to 105 days after stopping treatment, suggesting long-term efficacy.

Antireproductive changes instigated by efficient drug delivery via papaya seed chloroform extract-based nanoparticles in male rat Bandicota bengalensis.

Anti-reproductive potential of papaya seed chloroform extract-based solid lipid nanoparticles (PSCEN) was investigated for the first time in lesser bandicoot rat, Bandicota bengalensis. Mature male rats (n = 30 per group) were fed bait (loose mixture of cracked wheat, powdered sugar, and groundnut oil in the ratio 88:10:2) containing two different concentrations of PSCEN (5% and 10%) in a bi-choice condition for 15 days with one group as vehicle control. The ingestion of active ingredient in 15 days treatment was significantly (P ≤ 0.05) higher by rats treated with 10% PSCEN (39.17-58.70 g/kg body weight) as compared to rats treated with 5% PSCEN (21.30-33.23 g/kg body weight). A dose dependent significant (P ≤ 0.05) decrease was observed in the level of testosterone, FSH, LH and GnRH in plasma of treated rats. A significant (P ≤ 0.05) decrease was also observed in level of total soluble proteins, total lipids, phospholipids and cholesterol in both plasma and testicular tissue, and level of 17ß-HSD and 3ß-HSD in testicular tissue indicating anti-reproductive effects of PSCEN treatment. There was observed significant (P ≤ 0.05) effect of treatment on histomorphology of testis and cauda epididymis in the form of reduced tubular diameter, germinal epithelial thickness, number of germ cells and dissociation of epithelial cycle in seminiferous tubules, and reduced tubular diameter, increased epithelial thickness, vacuolization, loose contact of principle cells and reduced number of spermatozoa in the cauda epididymal tubules. Maximum antifertility effect was observed with 10% PSCEN treatment, which was not reversed upto 105 days of treatment withdrawal indicating long-term efficacy. The current investigation suggests the use of PSCEN in the management of reproduction of B. bengalensis by exerting influence on testicular and cauda epididymal functions and biochemical parameters.

Evolutionary conservation of the fidelity of transcription.

Accurate transcription is required for the faithful expression of genetic information. However, relatively little is known about the molecular mechanisms that control the fidelity of transcription, or the conservation of these mechanisms across the tree of life. To address these issues, we measured the error rate of transcription in five organisms of increasing complexity and found that the error rate of RNA polymerase II ranges from 2.9 × 10-6 ± 1.9 × 10-7/bp in yeast to 4.0 × 10-6 ± 5.2 × 10-7/bp in worms, 5.69 × 10-6 ± 8.2 × 10-7/bp in flies, 4.9 × 10-6 ± 3.6 × 10-7/bp in mouse cells and 4.7 × 10-6 ± 9.9 × 10-8/bp in human cells. These error rates were modified by various factors including aging, mutagen treatment and gene modifications. For example, the deletion or modification of several related genes increased the error rate substantially in both yeast and human cells. This research highlights the evolutionary conservation of factors that control the fidelity of transcription. Additionally, these experiments provide a reasonable estimate of the error rate of transcription in human cells and identify disease alleles in a subunit of RNA polymerase II that display error-prone transcription. Finally, we provide evidence suggesting that the error rate and spectrum of transcription co-evolved with our genetic code.

Metabolic Reconfiguration Activates Stemness and Immunomodulation of PDLSCs.

Periodontal ligament derived stem cells (PDLSC) are adult multipotent mesenchymal-like stem cells (MSCs) that can induce a promising immunomodulation to interact with immune cells for disease treatment. Metabolic reconfiguration has been shown to be involved in the immunomodulatory activity of MSCs. However, the underlying mechanisms are largely unknown, and it remains a challenging to establish a therapeutic avenue to enhance immunomodulation of endogenous stem cells for disease management. In the present study, RNA-sequencing (RNA-seq) analysis explores that curcumin significantly promotes PDLSC function through activation of MSC-related markers and metabolic pathways. In vitro stem cell characterization further confirms that self-renewal and multipotent differentiation capabilities are largely elevated in curcumin treated PDLSCs. Mechanistically, RNA-seq reveals that curcumin activates ERK and mTOR cascades through upregulating growth factor pathways for metabolic reconfiguration toward glycolysis. Interestingly, PDLSCs immunomodulation is significantly increased after curcumin treatment through activation of prostaglandin E2-Indoleamine 2,3 dioxygenase (PGE2-IDO) signaling, whereas inhibition of glycolysis activity by 2-deoxyglucose (2-DG) largely blocked immunomodulatory capacity of PDLSCs. Taken together, this study provides a novel pharmacological approach to activate endogenous stem cells through metabolic reprogramming for immunomodulation and tissue regeneration.

Determination of Oxidized Lipids in Commonly Consumed Foods and a Preliminary Analysis of Their Binding Affinity to PPARγ.

Foods rich in poly unsaturated fatty acids (PUFA) are vulnerable to oxidation. While it is well established that endogenously derived oxidized lipids are ligands of the transcription factor PPARγ, the binding ability of diet-derived oxidized lipids is unknown. Our two-fold objective was to determine the oxidized lipid content and PPARγ binding ability of commonly consumed foods. Extracted food lipids were assayed for the peroxide value, conjugated dienes, and aldehydes, and PPARγ binding was assessed by an in vitro PPARγ ligand screening assay. Oxidized lipids were present in all foods tested at the time of purchase, and oxidation did not increase during storage. The peroxide values for walnuts, sunflower seeds, and flax meal were significantly lower at the end of three months as compared to the day of purchase (peroxide value: 1.26 ± 0.13 vs. 2.32 ± 0.4; 1.65 ± 0.23 vs. 2.08 ± 0.09; 3.07 ± 0.22 vs. 9.94 ± 0.75 mEq/kg fat, p ≤ 0.05, respectively). Lipids extracted from French fries had the highest binding affinity (50.87 ± 11.76%) to PPARγ compared to other foods. Our work demonstrates that oxidized lipids are present in commonly consumed foods when purchased, and for the first time demonstrates that some contain ligands of PPARγ.

Germline mutation in POLR2A: a heterogeneous, multi-systemic developmental disorder characterized by transcriptional dysregulation.

De novo germline variation in POLR2A was recently reported to associate with a neurodevelopmental disorder. We report twelve individuals harboring putatively pathogenic de novo or inherited variants in POLR2A, detail their phenotypes, and map all known variants to the domain structure of POLR2A and crystal structure of RNA polymerase II. Affected individuals were ascertained from a local data lake, pediatric genetics clinic, and an online community of families of affected individuals. These include six affected by de novo missense variants (including one previously reported individual), four clinical laboratory samples affected by missense variation with unknown inheritance-with yeast functional assays further supporting altered function-one affected by a de novo in-frame deletion, and one affected by a C-terminal frameshift variant inherited from a largely asymptomatic mother. Recurrently observed phenotypes include ataxia, joint hypermobility, short stature, skin abnormalities, congenital cardiac abnormalities, immune system abnormalities, hip dysplasia, and short Achilles tendons. We report a significantly higher occurrence of epilepsy (8/12, 66.7%) than previously reported (3/15, 20%) (p value = 0.014196; chi-square test) and a lower occurrence of hypotonia (8/12, 66.7%) than previously reported (14/15, 93.3%) (p value = 0.076309). POLR2A-related developmental disorders likely represent a spectrum of related, multi-systemic developmental disorders, driven by distinct mechanisms, converging at a single locus.

Maintaining barrier function of infected gingival epithelial cells by inhibition of DNA methylation.

BACKGROUND: Infection and inflammation induce epigenetic changes that alter gene expression. In periodontal disease, inflammation, and microbial dysbiosis occur, which can lead to compromised barrier function of the gingival epithelia. Here, we tested the hypotheses that infection of cultured human gingival epithelial (HGEp) cells with Porphyromonas gingivalis disrupts barrier function by inducing epigenetic alterations and that these effects can be blocked by inhibitors of DNA methylation. METHODS: Primary HGEp cells were infected with P. gingivalis either in the presence or absence of the non-nucleoside DNA methyltransferase (DNMT) inhibitors RG108, (-) epigallocatechin-3-gallate (EGCG), or curcumin. Barrier function was assessed as transepithelial electrical resistance (TEER). DNA methylation and mRNA abundance were quantified for genes encoding components of three cell-cell junction complexes, CDH1, PKP2, and TJP1. Cell morphology and the abundance of cell-cell junction proteins were evaluated by confocal microscopy. RESULTS: Compared to non-infected cells, P. gingivalis infection decreased TEER (P < 0.0001) of HGEp cells; increased methylation of the CDH1, PKP2, and TJP1 (P < 0.0001); and reduced their expression (mRNA abundance) (P < 0.005). Pretreatment with DNMT inhibitors prevented these infection-induced changes in HGEp cells, as well as the altered morphology associated with infection. CONCLUSION: Pathogenic infection induced changes in DNA methylation and impaired the barrier function of cultured primary gingival epithelial cells, which suggests a mechanism for systemic consequences of periodontal disease. Inhibition of these events by non-nucleoside DNMT inhibitors represents a potential strategy to treat periodontal disease.

Inflammation in Periodontal Disease: Possible Link to Vascular Disease.

Inflammation is a well-organized protective response to pathogens and consists of immune cell recruitment into areas of infection. Inflammation either clears pathogens and gets resolved leading to tissue healing or remains predominantly unresolved triggering pathological processes in organs. Periodontal disease (PD) that is initiated by specific bacteria also triggers production of inflammatory mediators. These processes lead to loss of tissue structure and function. Reactive oxygen species and oxidative stress play a role in susceptibility to periodontal pathogenic bacterial infections. Periodontal inflammation is a risk factor for systemic inflammation and eventually cardiovascular disease (CVD). This review discusses the role of inflammation in PD and its two way association with other health conditions such as diabetes and CVD. Some of the mechanisms underpinning the links between inflammation, diabetes, CVD and PD are also discussed. Finally, we review available epidemiological data and other reports to assess possible links between oral health and CVD.

Nonstructural protein 5B promotes degradation of the NORE1A tumor suppressor to facilitate hepatitis C virus replication.

Hepatitis C virus (HCV) infection is a common risk factor for the development of liver cancer. The molecular mechanisms underlying this effect are only partially understood. Here, we show that the HCV protein, nonstructural protein (NS) 5B, directly binds to the tumor suppressor, NORE1A (RASSF5), and promotes its proteosomal degradation. In addition, we show that NORE1A colocalizes to sites of HCV viral replication and suppresses the replication process. Thus, NORE1A has antiviral activity, which is specifically antagonized by NS5B. Moreover, the suppression of NORE1A protein levels correlated almost perfectly with elevation of Ras activity in primary human samples. Therefore, NORE1A inactivation by NS5B may be essential for maximal HCV replication and may make a major contribution to HCV-induced liver cancer by shifting Ras signaling away from prosenescent/proapoptotic signaling pathways. CONCLUSION: HCV uses NS5B to specifically suppress NORE1A, facilitating viral replication and elevated Ras signaling. (Hepatology 2017;65:1462-1477).

Slumdog romance: Facebook love and digital privacy at the margins.

Facebook has consolidated its position as the one-stop-shop for social activity among the poor in the global South. Sex, romance, and love are key motivations for mobile and Internet technology usage among this demographic, much like the West. Digital romance is a critical context through which we gain fresh perspectives on Internet governance for an emerging digital and globalizing public. Revenge porn, slut-shaming, and Internet romance scams are a common and growing malady worldwide. Focusing on how it manifests in diverse digital cultures will aid in the shaping of new Internet laws for a more inclusive cross-cultural public. In specific, this article examines how low-income youth in two of the BRICS (Brazil, Russia, India, China and South Africa) nations - Brazil and India - exercise and express their notions on digital privacy, surveillance, and trust through the lens of romance. This allows for a more thorough investigation of the relationship between sexuality, morality, and governance within the larger Facebook ecology. As Facebook becomes the dominant virtual public sphere for the world's poor, we are compelled to ask whether inclusivity of the digital users comes at the price of diversity of digital platforms.

Hypothyroidism Impairs Human Stem Cell-Derived Pancreatic Progenitor Cell Maturation in Mice.

Pancreatic progenitors derived from human embryonic stem cells (hESCs) are a potential source of transplantable cells for treating diabetes and are currently being tested in clinical trials. Yet, how the milieu of pancreatic progenitor cells, including exposure to different factors after transplant, may influence their maturation remains unclear. Here, we examined the effect of thyroid dysregulation on the development of hESC-derived progenitor cells in vivo. Hypothyroidism was generated in SCID-beige mice using an iodine-deficient diet containing 0.15% propyl-2-thiouracil, and hyperthyroidism was generated by addition of L-thyroxine (T4) to drinking water. All mice received macroencapsulated hESC-derived progenitor cells, and thyroid dysfunction was maintained for the duration of the study ("chronic") or for 4 weeks posttransplant ("acute"). Acute hyperthyroidism did not affect graft function, but acute hypothyroidism transiently impaired human C-peptide secretion at 16 weeks posttransplant. Chronic hypothyroidism resulted in severely blunted basal human C-peptide secretion, impaired glucose-stimulated insulin secretion, and elevated plasma glucagon levels. Grafts from chronic hypothyroid mice contained fewer ß-cells, heterogenous MAFA expression, and increased glucagon(+) and ghrelin(+) cells compared to grafts from euthyroid mice. Taken together, these data suggest that long-term thyroid hormone deficiency may drive the differentiation of human pancreatic progenitor cells toward α- and ε-cell lineages at the expense of ß-cell formation.

Anti-cancer and anti-hepatitis C virus NS5B polymerase activity of etodolac 1,2,4-triazoles.

Arachidonic acid is an unsaturated fatty acid liberated from phospholipids of cell membranes. NSAIDs are known as targets of cyclooxygenase enzyme (COX-1, COX-2 and COX-3) in arachidonic acid metabolism. This mechanism of COX-2 in carcinogenesis causes cancer. In addition, COX-2 plays a role in the early stages of hepatocarcinogenesis. Hepatitis C virus (HCV) infection is cause of liver cirrhosis and hepatocellular carcinoma (HCC). The aim of our study was to improve effective agents against HCV. A novel series of new etodolac 1,2,4-triazoles derivatives (4a-h) have been synthesized and investigated for their activity against HCV NS5B polymerase. Compound 4a was found to be the most active with IC(50) value of 14.8 µM. In accordance with these results, compound 4a was screened for anti-cancer activity on liver cancer cell lines (Huh7, Mahlavu, HepG2, FOCUS). Compound 4a showed anti-cancer activity against Huh7 human hepatoma cell line with IC(50) value of 4.29 µM. Therefore, compound 4a could be considered as a new anti-cancer and anti-HCV lead compound.

Reversal of diabetes with insulin-producing cells derived in vitro from human pluripotent stem cells.

Transplantation of pancreatic progenitors or insulin-secreting cells derived from human embryonic stem cells (hESCs) has been proposed as a therapy for diabetes. We describe a seven-stage protocol that efficiently converts hESCs into insulin-producing cells. Stage (S) 7 cells expressed key markers of mature pancreatic beta cells, including MAFA, and displayed glucose-stimulated insulin secretion similar to that of human islets during static incubations in vitro. Additional characterization using single-cell imaging and dynamic glucose stimulation assays revealed similarities but also notable differences between S7 insulin-secreting cells and primary human beta cells. Nevertheless, S7 cells rapidly reversed diabetes in mice within 40 days, roughly four times faster than pancreatic progenitors. Therefore, although S7 cells are not fully equivalent to mature beta cells, their capacity for glucose-responsive insulin secretion and rapid reversal of diabetes in vivo makes them a promising alternative to pancreatic progenitor cells or cadaveric islets for the treatment of diabetes.

Design and synthesis of L- and D-phenylalanine derived rhodanines with novel C5-arylidenes as inhibitors of HCV NS5B polymerase.

Hepatitis C virus (HCV) NS5B polymerase is a key target for anti-HCV therapeutics development. Herein, we report the synthesis and in vitro evaluation of anti-NS5B polymerase activity of a molecular hybrid of our previously reported lead compounds 1 (IC50=7.7 µM) and 2 (IC50=10.6 µM) as represented by hybrid compound 27 (IC50=6.7 µM). We have explored the optimal substituents on the terminal phenyl ring of the 3-phenoxybenzylidene moiety in 27, by generating a set of six analogs. This resulted in the identification of compound 34 with an IC50 of 2.6 µM. To probe the role of stereochemistry towards the observed biological activity, we synthesized and evaluated the D-isomers 41 (IC50=19.3 µM) and 45 (IC50=5.4 µM) as enantiomers of the l-isomers 27 and 34, respectively. The binding site of compounds 32 and 34 was mapped to palm pocket-I (PP-I) of NS5B. The docking models of 34 and 45 within the PP-I of NS5B were investigated to envisage the molecular mechanism of inhibition.

Selective elimination of human pluripotent stem cells by an oleate synthesis inhibitor discovered in a high-throughput screen.

The use of human pluripotent stem cells (hPSCs) in cell therapy is hindered by the tumorigenic risk from residual undifferentiated cells. Here we performed a high-throughput screen of over 52,000 small molecules and identified 15 pluripotent cell-specific inhibitors (PluriSIns), nine of which share a common structural moiety. The PluriSIns selectively eliminated hPSCs while sparing a large array of progenitor and differentiated cells. Cellular and molecular analyses demonstrated that the most selective compound, PluriSIn #1, induces ER stress, protein synthesis attenuation, and apoptosis in hPSCs. Close examination identified this molecule as an inhibitor of stearoyl-coA desaturase (SCD1), the key enzyme in oleic acid biosynthesis, revealing a unique role for lipid metabolism in hPSCs. PluriSIn #1 was also cytotoxic to mouse blastocysts, indicating that the dependence on oleate is inherent to the pluripotent state. Finally, application of PluriSIn #1 prevented teratoma formation from tumorigenic undifferentiated cells. These findings should increase the safety of hPSC-based treatments.

Etodolac Thiosemicarbazides: A novel class of hepatitis C virus NS5B polymerase inhibitors.

A novel series of new etodolac hydrazide derivatives, 1-[2-(1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-yl)acetyl]-4-alkyl/aryl thiosemicarbazides [3a-h] have been synthesized in this study. The structures of the new compounds were determined by spectral (FT-IR, 1H-NMR, 13C-NMR and LC-MS) methods. Inhibition of hepatitis C virus NS5B RNA dependent RNA polymerase activity by etodolac thiosemicarbazides was evaluated in vitro by primer dependent elongation assays. The most active compounds of this series were 3a (SGK 224), 3d (SGK 227) and 3e (SGK 229) with IC50 values of 18.7 µM, 29.2 µM and 16.8 µM, respectively. Binding mode investigations of the most active compound 1-[2-(1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-yl)acetyl]-4-allyl thiosemicarbazide (3e) suggested that TP-II of HCV NS5B polymerase may be the potential binding site for etodolac thiosemicarbazides and provided clues for modifications to improve the potency of etodolac derivatives.