Piperine improves the quality of porcine oocytes by reducing oxidative stress

Oxidative stress caused by light and high temperature arises during in vitro maturation (IVM), resulting in low-quality embryos compared with those obtained in vivo. To overcome this problem, we investigated the influence of piperine (PIP) treatment during maturation of porcine oocytes on subsequent embryo development in vitro. Porcine oocytes were cultured in IVM medium supplemented with 0, 50, 100, 200, or 400 μM PIP. After parthenogenetic activation, the blastocyst (BL) formation was significantly higher and the apoptosis rate was significantly lower using 200 μM PIP-treated oocytes (200 PIP). In the 200 PIP group, the level of reactive oxygen species at the metaphase II stage was decreased, accompanied by an increased level of glutathione and increased expression of antioxidant processes (Nrf2, CAT, HO-1, SOD1, and SOD2). Consistently, chromosome misalignment and aberrant spindle organization were alleviated and phosphorylated p44/42 mitogen-activated protein kinase activity was increased in the 200 PIP group. Expression of development-related (CDX2, NANOG, POU5F1, and SOX2), anti-apoptotic (BCL2L1 and BIRC5), and pro-apoptotic (BAK, FAS, and CASP3) processes was altered in the 200 PIP group. Ultimately, embryo development was improved in the 200 PIP group following somatic cell nuclear transfer. These findings suggest that PIP improves the quality of porcine oocytes by reducing oxidative stress, which inevitably arises via IVM. In-depth mechanistic studies of porcine oocytes will improve the efficiencies of assisted reproductive technologies.

Ellagic acid treatment during in vitro maturation of porcine oocytes improves development competence after parthenogenetic activation and somatic cell nuclear transfer

Ellagic acid (EA) is a natural polyphenol and a free radical scavenger with antioxidant properties. This study investigated the protective effects of EA during in vitro maturation (IVM) of porcine oocytes. To determine the optimal concentration, IVM medium was supplemented with various concentrations of EA. Treatment with 10 μM EA (10 EA) resulted in the highest cleavage rate, blastocyst formation rate, and total cell number per blastocyst and the lowest percentage of apoptotic cell in parthenogenetic blastocysts. In the 10 EA group, abnormal spindle and chromosome misalignment were rescued and the ratio of phosphorylated p44/42 to total p44/42 was increased. Furthermore, the reactive oxygen species and glutathione levels were significantly decreased and increased, respectively, and antioxidant genes (Nrf2, HO-1, CAT, and SOD1) were significantly upregulated in the 10 EA group. mRNA expression of developmental-related (CDX2, POU5F1, and SOX2) and anti-apoptotic (BCL2L1) genes was significantly upregulated in the 10 EA group, while mRNA expression of pro-apoptotic genes (BAK, FAS, and CASP3) was significantly downregulated. Ultimately, following somatic cell nuclear transfer, the blastocyst formation rate was significantly increased and the percentage of apoptotic cell in blastocysts was significantly decreased in the 10 EA group. In conclusion, addition of 10 EA to IVM medium improved oocyte maturation and the subsequent embryo development capacity through antioxidant mechanisms. These findings suggest that EA can enhance the efficiencies of assisted reproductive technologies.

Efficacy of Allogeneic and Xenogeneic Exosomes for the Treatment of Canine Atopic Dermatitis: A Pilot Study

Canine atopic dermatitis (CAD) is a genetically predisposed inflammatory pruritic skin disease. The available treatments for CAD have several adverse effects and vary in efficacy, indicating the need for the development of improved treatments. In this study, we aimed to elucidate the therapeutic effects of allogeneic and xenogeneic exosomes on CAD. Six laboratory beagle dogs with CAD were randomly assigned to three treatment groups: control, canine exosome (cExos), or human exosome (hExos) groups. Dogs in the cExos and hExos groups were intravenously administered 1.5 mL of cExos (5 × 1010) and hExos (7.5 × 1011) solutions, respectively, while those in the control group were administered 1.5 mL of normal saline three times per week for 4 weeks. Skin lesion score and transepidermal water loss decreased in cExos and hExos groups compared with those in the control group. The exosome treatments decreased the serum levels of inflammatory cytokines (interferon-γ, interleukin-2, interleukin-4, interleukin-12, interleukin-13, and interleukin-31) but increased those of anti-inflammatory cytokines (interleukin-10 and transforming growth factor-β), indicating the immunomodulatory effect of exosomes. Skin microbiome analysis revealed that the exosome treatments alleviated skin bacterial dysbiosis. These results suggest that allogeneic and xenogeneic exosome therapy may alleviate CAD in dogs.

Flubendazole exposure disrupts neural development and function of zebrafish embryos (Danio rerio)

Flubendazole (FBZ) is a benzimidazole anthelmintic drug widely used for treating parasitic infections by disrupting microtubule formation and function through tubulin binding. Recently, its use has extended to include anticancer applications, leading to increased environmental exposure to benzimidazole drugs. However, the impact of FBZ on neural development in aquatic organisms, particularly in aquatic vertebrates, remains poorly understood. This study aimed to investigate the potential developmental toxicity of FBZ during neural development using zebrafish model. Various assessments, including analysis of overall developmental changes, morphological abnormalities, apoptosis, gene expression alterations, axon length measurements, and electrophysiological neural function, were performed. FBZ exposure resulted in concentration-dependent effects on survival rate, hatching rate, heartbeat, and the occurrence of developmental abnormalities. Notably, FBZ-induced changes included reductions in body length, head size, and eye size, as well as the detection of apoptotic cells in the central nervous system. Gene expression analysis revealed upregulation of apoptosis-related genes (p53, casp3, and casp8), downregulation of neural differentiation-related genes (shha, nrd, ngn1, and elavl3), and alterations in neural maturation and axon growth-related genes (gap43, mbp, and syn2a). Additionally, shortened motor neuron axon length and impaired electrophysiological neural function were observed. These findings provide novel insights into the potential risks of FBZ on the neural development of zebrafish embryos, emphasizing the need for risk prevention strategies and therapeutic approaches to address the environmental toxicity of benzimidazole anthelmintics.

Postnatal exposure to trimethyltin chloride induces retinal developmental neurotoxicity in mice via glutamate and its transporter related changes

Exposure to toxic substances during postnatal period is one of the major factors causing retinal developmental defects. The developmental toxicity of trimethyltin chloride (TMT), a byproduct of an organotin compound widely used in agriculture and industrial fields, has been reported; however, the effect on the mammalian retina during postnatal development and the mechanism have not been elucidated to date. We exposed 0.75 and 1.5 mg/kg of TMT to neonatal ICR mice (1:1 ratio of male and female) up to postnatal day 14 and performed analysis of the retina: histopathology, apoptosis, electrophysiological function, glutamate concentration, gene expression, and fluorescence immunostaining. Exposure to TMT caused delayed eye opening, eye growth defect and thinning of retinal layer. In addition, apoptosis occurred in the retina along with b-wave and spiking activity changes in the micro-electroretinogram. These changes were accompanied by an increase in the concentration of glutamate, upregulation of astrocyte-related genes, and increased expression of glial excitatory amino acid transporter (EAAT) 1 and 2. Conversely, EAAT 3, 4, and 5, mainly located in the neurons, were decreased. Our results are the first to prove postnatal retinal developmental neurotoxicity of TMT at the mammalian model and analyze the molecular, functional as well as morphological aspects to elucidate possible mechanisms: glutamate toxicity with EAAT expression changes. These mechanisms may suggest not only a strategy to treat but also a clue to prevent postnatal retina developmental toxicity of toxic substances.

P12.04.A Exosomes from glioma associated sphere forming cells induce a transition of invasive phenotype via transfer of EMP2 and CA9

Background

Glioblastoma multiforme (GBM) mostly occurs local recurrence at normal parenchyme adjacent tumor despite of conventional treatment. Glioma stem like cells (GSC) forming intratumoral heterogeneity within the GBM acquired the microenvironmental adaptation by inter-exosomal contents exchange between heterogenic cells. In addition, GSC has an invasive potential as like human GBM. Therefore, we investigate whether exosomal proteins of GSC affect the normal tissue invasion in GBM.

Material and Methods

Exosomes were isolated by Size-Exclusion method from conditioned media and validated by Electron microscope and Immunoblot assay. Exosomal proteomics were examined with Liquid Chromatography-Mass Spectrometry (LC/MS). To produce the fluorescent exosome, bi-cistron vectors were cloned with shRNA and CD63-GFP. To identify the effect of tranfected exosome, the isolated exosomes were treated to recipient cells and examined the invasion by 3D invasion assay and mouse intracranial model.

Results

Firstly, we dichotomized two groups following tumor invasion at matrigel assay and GSC derived orthotopic mouse model. CSC2 and X01 GSCs revealed highly invasive phenotype whereas 83NS and 528NS GSCs did not. Exosome was isolated in each group and identified by CD63 expression or electron microscopy. In proteomics analysis, hypoxia, extracellular matrix organization, GTPase cycle related proteins were enriched in highly invasive cell’s exosome. Among them, we focused the carbonic anhydrase IX (CA9) and the epithelial membrane protein 2 (EMP2) on its permissive role to glioblastoma invasion respectively. CA9 and EMP2 mRNA and protein levels were verified in GSCs and their exosomes and the high expression levels were detected in CSC2 and X01 compared to the low one in 83NS and 528NS GSCs. To evaluate the effects of CA9 and EMP2 on exosome mediated invasion potential, viral bi-cistron vectors was composed with the target gene knockdown and the CD63 fluorescence was used to detect intracellular exosome transfer. Interestingly, the decreased expression of phosphorylated FAK, a key invasive marker, was observed after Lentiviral mediated CA9- and EMP2-knockdown in highly invasive CSC2. To identify whether CA9 and EMP2 proteins are the intracellular effector protein responsible for exosome mediated glioma invasion, the donor exosomes (Exo-CSC2-sh-CA9 and Exo-CSC2-EMP2, after Lentiviral transfection to CSC2s) were isolated and treated to the non invasive 528NS cells as recipient cells. In 3D invasion assay, Exo-CSC2-shCA9 or Exo-CSC2-shEMP2 mediated tumor invasion was significantly decreased at 528NS GSCs compared to Exo-CSC2-shEV. These features were found at mouse intracranial model as well.

Conclusion

Together with these, we conclude that exosome derived from GSCs induces a transition of invasive phenotype via transfer of EMP2 and CA9 proteins.

Establishment of Neurotoxicity Assessment Using Microelectrode Array (MEA) with hiPSC-Derived Neurons and Evaluation of New Psychoactive Substances (NPS)

Background and Objectives

Currently, safety pharmacological tests for the central nervous system depend on animal behavioral analysis. However, due to the subjectivity of behavioral analysis and differences between species, there is a limit to appropriate nervous system toxicity assessment, therefore a new neurotoxicity assessment that can simulate the human central nervous system is required.

Methods and Results

In our study, we developed an in vitro neurotoxicity assessment focusing on neuronal function. To minimize the differences between species and fast screening, hiPSC-derived neurons and a microelectrode array (MEA) that could simultaneously measure the action potentials of the neuronal networks were used. After analyzing the molecular and electrophysiological characters of our neuronal network, we conducted a neurotoxicity assessment on neurotransmitters, neurotoxicants, illicit drugs, and new psychoactive substances (NPS). We found that most substances used in our experiments responded more sensitively to our MEA-based neurotoxicity assessment than to the conventional neurotoxicity assessment. Also, this is the first paper that evaluates various illicit drugs and NPS using MEA-based neurotoxicity assessment using hiPSC-derived neurons.

Conclusions

Our study expanded the scope of application of neurotoxicity assessment using hiPSC-derived neurons to NPS, and accumulated evaluation data of various toxic substances for hiPSC-derived neurons.

Immunomodulation of Pluripotent Stem Cell-Derived Mesenchymal Stem Cells in Rotator Cuff Tears Model

Background: Rotator cuff tears (RCTs) induce chronic muscle weakness and shoulder pain. Treatment of RCT using surgery or drugs causes lipid infiltration and fibrosis, which hampers tissue regeneration and complete recovery. The pluripotent stem cell-derived multipotent mesenchymal stem cells (M-MSCs) represent potential candidate next-generation therapies for RCT. Methods: The difference between M-MSCs and adult-MSCs was compared and analyzed using next-generation sequencing (NGS). In addition, using a rat model of RCT, the muscle recovery ability of M-MSCs and adult-MSCs was evaluated by conducting a histological analysis and monitoring the cytokine expression level. Results: Using NGS, it was confirmed that M-MSC was suitable for transplantation because of its excellent ability to regulate inflammation that promotes tissue repair and reduced apoptosis and rejection during transplantation. In addition, while M-MSCs persisted for up to 8 weeks in vivo, they significantly reduced inflammation and adipogenesis-related cytokine levels in rat muscle. Significant differences were also confirmed in histopathological remission. Conclusions: M-MSCs remain in the body longer to modulate immune responses in RCTs and have a greater potential to improve muscle recovery by alleviating acute inflammatory responses. This indicates that M-MSCs could be used in potential next-generation RCT therapies.

Next-Generation Intestinal Toxicity Model of Human Embryonic Stem Cell-Derived Enterocyte-Like Cells

The gastrointestinal tract is the most common exposure route of xenobiotics, and intestinal toxicity can result in systemic toxicity in most cases. It is important to develop intestinal toxicity assays mimicking the human system; thus, stem cells are rapidly being developed as new paradigms of toxicity assessment. In this study, we established human embryonic stem cell (hESC)-derived enterocyte-like cells (ELCs) and compared them to existing in vivo and in vitro models. We found that hESC-ELCs and the in vivo model showed transcriptomically similar expression patterns of a total of 10,020 genes than the commercialized cell lines. Besides, we treated the hESC-ELCs, in vivo rats, Caco-2 cells, and Hutu-80 cells with quarter log units of lethal dose 50 or lethal concentration 50 of eight drugs—chloramphenicol, cycloheximide, cytarabine, diclofenac, fluorouracil, indomethacin, methotrexate, and oxytetracycline—and then subsequently analyzed the biomolecular markers and morphological changes. While the four models showed similar tendencies in general toxicological reaction, hESC-ELCs showed a stronger correlation with the in vivo model than the immortalized cell lines. These results indicate that hESC-ELCs can serve as a next-generation intestinal toxicity model.

BAPTA, a calcium chelator, neuroprotects injured neurons in vitro and promotes motor recovery after spinal cord transection in vivo

Aim

Despite animal evidence of a role of calcium in the pathogenesis of spinal cord injury, several studies conducted in the past found calcium blockade ineffective. However, those studies involved oral or parenteral administration of Ca++ antagonists. We hypothesized that Ca++ blockade might be effective with local/immediate application (LIA) at the time of neural injury.

Methods

In this study, we assessed the effects of LIA of BAPTA (1,2‐bis (o‐aminophenoxy) ethane‐N, N, N′, N'‐tetraacetic acid), a cell‐permeable highly selective Ca++ chelator, after spinal cord transection (SCT) in mice over 4 weeks. Effects of BAPTA were assessed behaviorally and with immunohistochemistry. Concurrently, BAPTA was submitted for the first time to multimodality assessment in an in vitro model of neural damage as a possible spinal neuroprotectant.

Results

We demonstrate that BAPTA alleviates neuronal apoptosis caused by physical damage by inhibition of neuronal apoptosis and reactive oxygen species (ROS) generation. This translates to enhanced preservation of electrophysiological function and superior behavioral recovery.

Conclusion

This study shows for the first time that local/immediate application of Ca++ chelator BAPTA is strongly neuroprotective after severe spinal cord injury.

Toxicity Assessment of Transfluthrin, Benzyl Butyl Phthalate, and 17β-Estradiol on the Primary Fibroblast of the Striped Field Mouse, Apodemus agrarius

Environmental pollution (EP) is a well-known threat to wild animals, but its toxicological impact is poorly understood. In vitro toxicity evaluation using cells of lower predators could be a promising way to assess and monitor the effects of EPs on whole wildlife populations that are related in the food web. Here, we describe EPs' toxic effect and mechanism in the primary fibroblast derived from the embryo of the striped field mouse, Apodemus agrarius. Characterization of the primary fibroblast was via morphology, genetics, immunocytochemistry, and stable culture conditions for optimal toxicity screening. Cell viability assays-MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and lactate dehydrogenase (LDH)-were performed to observe cytotoxicity, and quantitative PCR was conducted to confirm gene alteration by EP exposure. MTT and LDH assays confirmed the cytotoxicity of transfluthrin (TF), benzyl butyl phthalate (BBP), and 17β-estradiol (E2) with IC50 values of 10.56 μM, 10.82 μM, and 24.08 μM, respectively, following 48-h exposures. mRNA expression of androgen-binding protein, growth hormone receptor, cytochrome C oxidase, and cytochrome P450-1A1 was induced after exposure to TF, BBP, and E2. We unveiled new EP mechanisms at the mammalian cellular level and discovered potential biomarker genes for monitoring of EPs. Based on our findings, we propose the primary fibroblast of A. agrarius as a valuable model to assess the toxicological effects of EP on wildlife.

Development and validation of dual-cardiotoxicity evaluation method based on analysis of field potential and contractile force of human iPSC-derived cardiomyocytes / multielectrode assay platform

A recent in vitro cardiovascular safety pharmacology test uses cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) to overcome the limitations of the classical test systems, such as species differences and local channel analysis. The Comprehensive in vitro Proarrhythmia Assay (CiPA) is a new proarrhythmia screening paradigm proposed by a CiPA steering expert group, which essentially requires iPSCs derived cardiomyocyte-based electrophysiological evaluation technology. Moreover, the measurement of the contractile force is also emerging as an important parameter to recapitulate non-proarrhythmic cardiotoxicity. Therefore, we constructed an multielectrode assay (MEA) evaluation method that can measure the electrophysiological changes with 6 reference drugs in hiPSC-derived cardiomyocytes. Subsequently, it was confirmed that the electrophysiological were changed in accordance with the mechanism of action of the drugs. Furthermore, based on the multi-probe impedance, we confirmed the decrease in contractile force due to treatment with drugs, and developed a platform to evaluate cardiotoxicity according to drugs along with field potential changes. Our excitation-contraction coupling cardiotoxicity assessment is considered to be more supportive in cardiac safety studies on pharmacologic sensitivity by complementing each assessment parameter.

Albendazole exerts antiproliferative effects on prostate cancer cells by inducing reactive oxygen species generation

Benzimidazole derivatives are used for their antihelmintic properties, but have also been reported to exert anticancer effects. In the present study, the anticancer effects of albendazole on prostate cancer cells were assessed using proliferation, clonogenic and migration assays. To investigate the anticancer mechanisms of albendazole, reactive oxygen species (ROS) levels were measured, and the expression of genes associated with oxidative stress and Wnt/β-catenin signaling was confirmed by reverse transcription-quantitative PCR and western blotting. Albendazole selectively inhibited the proliferation of the PC3, DU145, LNCaP and AT2 prostate cancer cell lines at concentrations that did not affect the proliferation of a normal prostate cell line (RWPE-1). Albendazole also inhibited the colony formation and migration of PC3 and DU145 cells, as well as inducing ROS production. Diphenyleneiodonium chloride, an inhibitor of NADPH oxidase (NOX), one of the sources of ROS, decreased basal ROS levels in the PC3 and DU145 cells, but did not reduce albendazole-associated ROS production, suggesting that ROS production following albendazole treatment was NOX-independent. The anticancer effect was decreased when albendazole-induced ROS was reduced by treatment with antioxidants (glutathione and N-acetylcysteine). Furthermore, albendazole decreased the mRNA expression of CDGSH iron sulfur domain 2, which regulates antioxidant activity against ROS, as well as the antioxidant enzymes catalase, and glutathione peroxidase 1 and 3. Albendazole also decreased the mRNA expression of catenin β1 and transcription factor 4, which regulate Wnt/β-catenin signaling and its associated targets, Twist family BHLH transcription factor 1 and BCL2. The albendazole-related decrease in the expression levels of oxidative stress-related genes and Wnt/β-catenin signaling proteins was thought to be associated with ROS production. These results suggest that the antihelmintic drug, albendazole, has inhibitory effects against prostate cancer cells in vitro. Therefore, albendazole may potentially be used as a novel anticancer agent for prostate cancer.

TALEN-mediated generation of Nkx3.1 knockout rat model

BACKGROUND

Recent developments in gene editing, using transcriptional activator-like effector nucleases (TALENs), have greatly helped the generation of genetically engineered animal models. The NK3 homeobox 1 (NKX3.1) protein plays important roles in prostate development and protein production, and functions as a tumor suppressor. Recently, NKX3.1 was shown to be associated with breast cancer in humans.

METHODS

Our aim was to create a new rat model to elucidate the functions of NKX3.1. To that end, we generated Nkx3.1 knockout rats using TALENs and analyzed their phenotype. TALEN-mediated Nkx3.1 knockout was confirmed by T7 endonuclease I (T7E1) assay and DNA sequencing. Prostate weight and fertility were evaluated in the knockout rats, besides determining the proportion of epithelial cells and messenger RNA (mRNA) expression of genes associated with carcinogenesis. Breast tumors were examined by histopathology.

RESULTS

Results suggested Nkx3.1 knockout rats have reduced fertility, decreased prostate weights, and increased epithelial cell layers. The mRNA expression of genes related to prostate carcinogenesis, namely Ar, Akt, and Pi3k, also increased. Moreover, the Nkx3.1 knockout rats often developed malignant breast tumors.

CONCLUSIONS

We, therefore, successfully created the first Nkx3.1 knockout rat model, using TALEN-mediated gene targeting, and used it to identify defects associated with Nkx3.1 deficiency, not previously observed in mice. Loss of Nkx3.1 in rats led to lower reproductive capacity, and decreased prostate weights, apart from the risk of developing breast cancer. We, thus, proposed Nkx3.1 knockout rats as reliable models for studying the role of NKX3.1 in decreased prostate weights, fertility, and breast cancer, as well as in prostate cancer.

Anti-Inflammatory Effects of M-MSCs in DNCB-Induced Atopic Dermatitis Mice

Atopic dermatitis (AD) is an inflammatory skin disease caused by an imbalance between Th1 and Th2 cells. AD patients suffer from pruritus, excessive dryness, red or inflamed skin, and complications such as sleep disturbances and depression. Although there are currently many AD treatments available there are insufficient data on their long-term stability and comparative effects. Moreover, they have limitations due to various side effects. Multipotent mesenchymal stem cells (M-MSCs) might have potential for next-generation AD therapies. MSCs are capable of immune function regulation and local inflammatory response inhibition. M-MSCs, derived from human embryonic stem cells (hESC), additionally have a stable supply. In L507 antibody array, M-MSCs generally showed similar tendencies to bone marrow-derived mesenchymal stem cells (BM-MSCs), although the immunoregulatory function of M-MSCs seemed to be superior to BM-MSCs. Based on the characteristics of M-MSCs on immunoregulatory functions, we tested a M-MSC conditioned media concentrate (MCMC) in mice with AD lesions on their dorsal skin. MCMC significantly decreased RNA expression levels of inflammatory cytokines in the mouse dorsal skin. It also suppressed serum IgE levels. In addition, significant histopathologic alleviation was identified. In conclusion, secretions of M-MSCs have the potential to effectively improve AD-related inflammatory lesions. M-MSCs showed potential for use in next-generation AD treatment.

Fabrication of a Polycaprolactone/Alginate Bipartite Hybrid Scaffold for Osteochondral Tissue Using a Three-Dimensional Bioprinting System

Osteochondral defects, including damage to both the articular cartilage and the subchondral bone, are challenging to repair. Although many technological advancements have been made in recent years, there are technical difficulties in the engineering of cartilage and bone layers, simultaneously. Moreover, there is a great need for a valuable in vitro platform enabling the assessment of osteochondral tissues to reduce pre-operative risk. Three-dimensional (3D) bioprinting systems may be a promising approach for fabricating human tissues and organs. Here, we aimed to develop a polycaprolactone (PCL)/alginate bipartite hybrid scaffold using a multihead 3D bioprinting system. The hybrid scaffold was composed of PCL, which could improve the mechanical properties of the construct, and alginate, encapsulating progenitor cells that could differentiate into cartilage and bone. To differentiate the bipartite hybrid scaffold into osteochondral tissue, a polydimethylsiloxane coculture system for osteochondral tissue (PCSOT) was designed and developed. Based on evaluation of the biological performance of the novel hybrid scaffold, the PCL/alginate bipartite scaffold was successfully fabricated; importantly, our findings suggest that this PCSOT system may be applicable as an in vitro platform for osteochondral tissue engineering.

Development and evaluation of next-generation cardiotoxicity assay based on embryonic stem cell-derived cardiomyocytes

In accordance with requirements of the ICH S7B safety pharma-cology guidelines, numerous next-generation cardiotoxicity studies using human stem cell-derived cardiomyocytes (CMs) are being conducted globally. Although several stem cell-derived CMs are being developed for commercialization, there is insufficient research to verify if these CMs can replace animal experiments. In this study, in vitro high-efficiency CMs derived from human embryonic stem cells (hESC-CMs) were compared with Sprague-Dawley rats as in vivo experimental animals, and primary cultured in vitro rat-CMs for cardiotoxicity tests. In vivo rats were administrated with two consecutive injections of 100 mg/kg isoproterenol, 15 mg/kg doxorubicin, or 100 mg/kg nifedipine, while in vitro rat-CMs and hESC-CMs were treated with 5 µM isoproterenol, 5 µM doxorubicin, and 50 µM nifedipine. We have verified the equivalence of hESC-CMs assessments over various molecular biological markers, morphological analysis. Also, we have identified the advantages of hESC-CMs, which can distinguish between species variability, over electrophysiological analysis of ion channels against cardiac damage. Our findings demonstrate the possibility and advantage of high-effi-ciency hESC-CMs as next-generation cardiotoxicity assessment.

Vitrification for cryopreservation of 2D and 3D stem cells culture using high concentration of cryoprotective agents

BACKGROUND

Vitrification is the most promising technology for successful cryopreservation of living organisms without ice crystal formation. However, high concentrations (up to ~ 6-8 M) of cryoprotective agents (CPAs) used in stem cell induce osmotic and metabolic injuries. Moreover, the application of conventional slow-freezing methods to cultures of 3-D organoids of stem cells in various studies, is limited by their size.

RESULTS

In this study, we evaluated the effect of high concentrations of CPAs including cytotoxicity and characterized human mesenchymal stem cell (MSC) at single cell level. The cell viability, cellular damage, and apoptotic mechanisms as well as the proliferation capacity and multipotency of cells subjected to vitrification were similar to those in the slow-freezing group. Furthermore, we identified the possibility of vitrification of size-controlled 3-D spheroids for cryopreservation of organoid with high survivability.

CONCLUSIONS

Our results demonstrate successful vitrification of both single cell and spheroid using high concentration of CPAs in vitro without cytotoxicity.

Loss of glutathione peroxidase 3 induces ROS and contributes to prostatic hyperplasia in Nkx3.1 knockout mice

BACKGROUND

Glutathione peroxidase 3 (Gpx3) protects cells from oxidative stress, and its reduced expression in human prostate cancer has been reported.

OBJECTIVES

We hypothesized that Gpx3 might play an important role in the development of prostatic intraepithelial neoplasia (PIN), a pre-cancerous state of the prostate, and aimed to highlight the underlying molecular mechanism.

MATERIALS AND METHODS

The following double-knockout mice Nkx3.1-/-; Gpx3+/+, Nkx3.1-/-; Gpx3+/-, Nkx3.1-/-; Gpx3-/- were produced. Randomly divided animals were weighed, and their genitourinary tract (GUT) weights were determined after euthanasia at 4, 8, and 12 months. The mRNA expression of the genes involved in oxidative stress and Wnt signaling was analyzed in the prostate. Histopathology, ROS, and superoxide dismutase (SOD) activities were also measured.

RESULTS

Loss of Gpx3 did not affect body weight and GUT weight in Nkx3.1 knockout mice. The mRNA expression of SOD3, iNOS, Hmox, and CISD2, which are associated with oxidative stress, was increased in Nkx3.1-/-; Gpx3-/- mice at 4 months but decreased at 8 and 12 months. There was no change in β-catenin and its targets associated with Wnt signaling. Increased ROS and decreased SOD activity were observed in Nkx3.1-/-; Gpx3-/- mice at 12 months of age. The histopathologic score and epithelium thickness were increased, and lumen area was decreased in Gpx3 knockout mice.

DISCUSSION AND CONCLUSIONS

Gpx3 loss increased the hyperplasia of PIN in the pre-cancerous stage of the prostate. Loss of Gpx3 induced oxidative stress. Histopathologically, no invasive carcinoma was identified, and Gpx3 loss did not increase Wnt/β-catenin signaling. Further research on the role of GPX3 in the transition of PIN to invasive carcinoma is needed. We show, for the first time, that the antioxidant enzyme GPX3 plays a vital role in inhibiting hyperplasia in the PIN stage of the prostate gland in vivo.

Molecular Design of Highly Efficient Heavy-Atom-Free Triplet BODIPY Derivatives for Photodynamic Therapy and Bioimaging

Novel BODIPY photosensitizers were developed for imaging-guided photodynamic therapy. The introduction of a strong electron donor to the BODIPY core through a phenyl linker combined with the twisted arrangement between the donor and the BODIPY acceptor is essential for reducing the energy gap between the lowest singlet excited state and the lowest triplet state (ΔE_ST ), leading to a significant enhancement in the intersystem crossing (ISC) of the BODIPYs. Remarkably, the BDP-5 with the smallest ΔE_ST (ca. 0.44 eV) exhibited excellent singlet oxygen generation capabilities in both organic and aqueous solutions. BDP-5 also displayed bright emission in the far-red/near-infrared region in the condensed states. More importantly, both in vitro and in vivo studies demonstrated that BDP-5 NPs displayed a high potential for photodynamic cancer therapy and bioimaging.

Pimozide Inhibits the Human Prostate Cancer Cells Through the Generation of Reactive Oxygen Species

The United States Food and Drug Administration-approved antipsychotic drug, pimozide, has anticancer activities. However, the role of reactive oxygen species (ROS) in its effect on prostate cancer is not well-known. We examined cell proliferation, colony formation, migration, ROS production, and the expression of antioxidant-related genes after treatment of human prostate cancer PC3 and DU145 cells with pimozide. In addition, histopathology, ROS production, and superoxide dismutase (SOD) activity were analyzed after administering pimozide to TRAMP, a transgenic mouse with prostate cancer. Pimozide increased the generation of ROS in both cell lines and inhibited cell proliferation, migration, and colony formation. Oxidative stress induced by pimozide caused changes in the expression of antioxidant enzymes (SOD1, peroxiredoxin 6, and glutathione peroxidase 2) and CISD2. Co-treatment with glutathione, an antioxidant, reduced pimozide-induced ROS levels, and counteracted the inhibition of cell proliferation. Administration of pimozide to TRAMP mice reduced the progression of prostate cancer with increased ROS generation and decreased SOD activity. These results suggest that the antipsychotic drug, pimozide, has beneficial effects in prostate cancer in vivo and in vitro. The mechanism of pimozide may be related to augmenting ROS generation. We recommend pimozide as a promising anticancer agent.

Correction to: Phloretin Inhibits the Human Prostate Cancer Cells through the Generation of Reactive Oxygen Species

AbstractThe original version of this article unfortunately contained an error in Figs. 1, 5 and 6. The asterisks and bars indicating statistical significance were missing in the figures.

Phloretin Inhibits the Human Prostate Cancer Cells Through the Generation of Reactive Oxygen Species

Phloretin is a flavonoid with known anticancer activities. However, we do not fully understand how phloretin mitigates prostate cancer on the molecular level. In the present study, we examined changes in proliferation, colony formation, and migration after phloretin treatment in human prostate cancer cells PC3 and DU145. We measured reactive oxygen species (ROS) and gene expression. Phloretin increased ROS and suppressed cell proliferation, migration, and colony formation in both cell lines. Additionally, phloretin treatment increased oxidative stress, as demonstrated through lower antioxidant enzymes (catalase, SOD2, Gpx1, Gpx3). In addition, their regulator CISD2 decreased in expression. We also found that increased ROS significantly downregulated multiple components of the Wnt/β-catenin signaling pathway (β-catenin, TCF4, FoxA2, c-Myc) and Twist1. Thus, anticancer activity of phloretin against human prostate cancer cells occurs through generating ROS to influence Wnt/β-catenin signaling. The results of this study suggest that phloretin has a therapeutic effect on prostate cancer in vitro, inhibiting the proliferation and migration of cancer cell lines PC3 and DU145. The mechanism of phloretin appears to be increasing ROS production. We thus recommend phloretin as a promising anticancer therapeutic agent.

Trimethyltin chloride induces reactive oxygen species-mediated apoptosis in retinal cells during zebrafish eye development

Trimethyltin chloride (TMT), one of the most widely used organotin compounds in industrial and agricultural fields, is widespread in soil, aquatic systems, foodstuffs and household items. TMT reportedly has toxic effects on the nervous system; however, there is limited information about its effects on eye development and no clear associated mechanisms have been identified. Therefore, in the present study, we investigated eye morphology, vison-related behavior, reactive oxygen species (ROS) production, apoptosis, histopathology, and gene expression to evaluate the toxicity of TMT during ocular development in zebrafish embryos. Exposure to TMT decreased the axial length and surface area of the eye and impaired the ability of zebrafish to recognize light. 2',7'-dichlorofluorescein diacetate and acridine orange assays revealed dose-dependent increases in ROS formation and apoptosis in the eye. Furthermore, pyknosis of retinal cells was confirmed through histopathological analysis. Antioxidative enzyme-related genes were downregulated and apoptosis-inducing genes were upregulated in TMT-treated zebrafish compared to expression in controls. Retinal cell-specific gene expression was suppressed mainly in retinal ganglion cells, bipolar cells, and photoreceptor cells, whereas amacrine cell-, horizontal cell-, and Müller cell-specific gene expression was enhanced. Our results demonstrate for the first time the toxicity of TMT during eye development, which occurs through the induction of ROS-mediated apoptosis in retinal cells during ocular formation.

Establishment, characterization, and toxicological application of a spontaneous immortalized cell line from the striped field mouse, Apodemus agrarius

It is important to secure various biological resources in situations of diminishing wildlife genetic diversity. Cultured cells are useful bioresources because they can stably store genetic information for a long time and can be expanded efficiently. Here, we established fibroblast cell lines from Apodemus agrarius as a new living resource. A. agrarius is an important sub-predator species in ecosystem food chains and for the study of infection epidemiology. Established cell lines were characterized by chromosome and mitochondrial gene analysis, the observation of cell morphology, and their anchorage-dependent growth pattern. We also examined susceptibility to endocrine disruptors (EDCs), which threaten biodiversity, using these established cell lines. Nonylphenol (NP) is a well-known EDC that threatens wildlife; however, its impact is poorly understood. Sensitivity to NP was confirmed based on two cell viability assays, namely MTT and lactate dehydrogenase. Cells exposed to NP were analyzed for abnormalities in cell growth and mitochondrial function by evaluating the expression of genes (specifically, those encoding growth hormone receptor and cytochrome C oxidase). This newly established cell line represents a valuable tool for the evaluation of toxic substances such as EDCs and this cell was biobanked for study about relationship between various environmental pollution and decreasing biodiversity.

Respiratory Toxicity of Polyhexamethylene Guanidine Phosphate Exposure in Zebrafish

Humidifier disinfectants containing polyhexamethylene guanidine phosphate (PHMG-P) can induce pulmonary toxicity and has caused human casualties in South Korea since 2006. Thereby, the safety evaluation of household chemicals such as PHMG-P has garnered increased importance. However, many limitations, such as the lack of specialized facilities and animal welfare concerns associated with the use of murine models, persist. Zebrafish gills have high functional and structural similarity to mammalian lungs. Moreover, zebrafish are sensitive to toxic substances, resulting in changes in behavioral or ventilatory patterns. Based on these facts, in this study, we aimed to evaluate the pulmonary toxicity of PHMG-P in zebrafish. Zebrafish exposed to PHMG-P showed an increase in mRNA levels of inflammatory factors persisting for 28 days along with histopathologic changes in the gills. An exposure time-dependent alteration in infiltration of inflammatory cells and destruction of gill lamellae was observed. In addition, an increase in mRNA levels of fibrosis factors was observed in gills exposed to PHMG-P for 28 days, as assessed by collagen staining with Masson's trichrome. These results supported the cellular level results. Taken together, our results reveal pulmonary toxic effects of PHMG-P and suggest useful markers for evaluating pulmonary toxicity.

Troglitazone inhibits the migration and invasion of PC-3 human prostate cancer cells by upregulating E-cadherin and glutathione peroxidase 3

Troglitazone (TGZ) is a synthetic peroxisome proliferator-activated receptor γ (PPARγ) ligand that exhibits potential antitumor effects on a number of cancer subtypes, including prostate cancer. However, little is known about the effect of TGZ on metastasis in prostate cancer. The aim of the present study was to determine the inhibitory effect and mechanism underlying TGZ on cell growth, migration and invasion using the prostate cancer PC-3 cell line. Cellular migration and invasion were evaluated by performing a wound healing assay and Matrigel assay, respectively. The expression levels of mRNA and protein were determined by reverse transcription-quantitative polymerase chain reaction and western blotting. The results demonstrated that TGZ dose-dependently inhibited cell migration and invasion of PC-3 cells. The present study also revealed that TGZ increased the mRNA and protein levels of E-cadherin and glutathione peroxidase 3 (GPx3) in human prostate cancer PC-3 cells. In addition, GW9662, a PPARγ antagonist, attenuated the increased mRNA and protein levels of E-cadherin and GPx3, suggesting that the PPARγ-dependent signaling pathway was involved. Taken together, these results suggested that the anti-migration and anti-invasion effect of TGZ on PC-3 prostate cancer cells is, at least in part, mediated via upregulation of E-cadherin and GPx3. The present study also concluded that PPARγ may be used as a potential remedial target for the prevention and treatment of prostate cancer cell invasion and metastasis.

A case of active incomplete biliary cirrhosis in an aged female Japanese macaque (Macaca fuscata)

We describe the first case of biliary cirrhosis in Japanese macaque. Clinical signs had not been detected. The liver was nodular. Histopathologically, portal-to-portal pattern of fibrosis might have indicated chronic cholestasis. Fibrotic septa were infiltrated with inflammatory cells. Therefore, this case could be diagnosed as active incomplete biliary cirrhosis.

Triclosan affects axon formation in the neural development stages of zebrafish embryos (Danio rerio)

Triclosan (TCS) is an organic compound with a wide range of antibiotic activity and has been widely used in items ranging from hygiene products to cosmetics; however, recent studies suggest that it has several adverse effects. In particular, TCS can be passed to both fetus and infants, and while some evidence suggests in vitro neurotoxicity, there are currently few studies concerning the mechanisms of TCS-induced developmental neurotoxicity. Therefore, this study aimed to clarify the effect of TCS on neural development using zebrafish models, by analyzing the morphological changes, the alterations observed in fluorescence using HuC-GFP and Olig2-dsRED transgenic zebrafish models, and neurodevelopmental gene expression. TCS exposure decreased the body length, head size, and eye size in a concentration-dependent manner in zebrafish embryos. It increased apoptosis in the central nervous system (CNS) and particularly affected the structure of the CNS, resulting in decreased synaptic density and shortened axon length. In addition, it significantly up-regulated the expression of genes related to axon extension and synapse formation such as α1-Tubulin and Gap43, while decreasing Gfap and Mbp related to axon guidance, myelination and maintenance. Collectively, these changes indicate that exposure to TCS during neurodevelopment, especially during axonogenesis, is toxic. This is the first study to demonstrate the toxicity of TCS during neurogenesis, and suggests a possible mechanism underlying the neurotoxic effects of TCS in developing vertebrates.

An outbreak of toxoplasmosis in squirrel monkeys (Saimiri sciureus) in South Korea

BACKGROUND

Toxoplasma gondii (T. gondii) is an intracellular protozoan parasite that can infect warm-blooded animals including humans. New World monkeys, such as squirrel monkeys, are more susceptible to T. gondii than Old World monkeys, often developing fatal disease.

METHODS

In this study, seven of thirteen dead squirrel monkeys at Seoul Grand Park were tested to find the cause of sudden death.

RESULTS

The main histopathological findings included interstitial pneumonia, necrotizing hepatitis, and splenitis. Periodic acid-Schiff staining of liver, spleen, and lung revealed cyst structures consistent with bradyzoites. Amplification of the B1 gene was detected in the liver or spleen of all monkeys. Additionally, a restriction fragment length polymorphism assay and phylogenetic analysis of the GRA6 amplicon revealed a consistent clustering with the type II strain of T. gondii.

CONCLUSIONS

This study is the first report of T. gondii infection of squirrel monkeys in Korea, and the first report of type II T. gondii based on GRA6 analysis in Korea.

Neuropilin-2 gene expression correlates with malignant progression in cutaneous melanoma

BACKGROUND

It is currently not possible to predict the metastatic potential of early-stage melanoma lesions by histological examination alone; however, a significant number of thin melanomas will progress over time to advanced disease. Molecular biomarkers that could identify patients with melanoma at high risk at the time of original diagnosis would contribute significantly to improved patient outcomes and increased survival. Neuropilin-2 (NRP2), a cell surface receptor involved in tumour-associated angiogenesis and lymphangiogenesis, has recently been shown to be expressed in melanoma.

OBJECTIVES

To evaluate the potential value of NRP2 gene transcript levels as biomarkers for malignant melanoma progression.

METHODS

We measured NRP2 gene expression in a panel of formalin-fixed paraffin-embedded tissue specimens consisting of naevi, primary melanomas and metastatic melanomas using quantitative reverse transcriptase-polymerase chain reaction technique.

RESULTS

NRP2 levels are clearly segregated among the groups of naevi, primary and metastatic melanoma samples with a statistical trend towards increasing NRP2 gene expression correlating with disease progression. Logistic regression analysis reveals that the probability of malignant progression increases with elevated levels of NRP2 (odds ratio of 2·60 with confidence interval 1·29-5·21). Within the group of primary melanomas, there is a positive correlation (r = 0·823) between NRP2 expression and Breslow depth. This correlation was validated in an independent sample set of patients with melanoma.

CONCLUSIONS

This preliminary study strongly supports the significance of NRP2 as a useful biomarker for malignant progression of melanoma, which may be useful for early identification of patients with melanoma at high risk.

Mesothelin is overexpressed in the vast majority of ductal adenocarcinomas of the pancreas: identification of a new pancreatic cancer marker by serial analysis of gene expression (SAGE)

PURPOSE

Effective new markers of pancreatic carcinoma are urgently needed. In a previous analysis of gene expression in pancreatic adenocarcinoma using serial analysis of gene expression (SAGE), we found that the tag for the mesothelin mRNA transcript was present in seven of eight SAGE libraries derived from pancreatic carcinomas but not in the two SAGE libraries derived from normal pancreatic duct epithelial cells. In this study, we evaluate the potential utility of mesothelin as a tumor marker for pancreatic adenocarcinoma.

EXPERIMENTAL DESIGN

Mesothelin mRNA expression was evaluated in pancreatic adenocarcinomas using reverse-transcription PCR (RT-PCR) and in situ hybridization, whereas mesothelin protein expression was evaluated by immunohistochemistry.

RESULTS

Using an online SAGE database (http://www.ncbi.nlm.gov/SAGE), we found the tag for mesothelin to be consistently present in the mesothelioma, ovarian cancer, and pancreatic cancer libraries but not in normal pancreas libraries. Mesothelin mRNA expression was confirmed by in situ hybridization in 4 of 4 resected primary pancreatic adenocarcinomas and by RT-PCR in 18 of 20 pancreatic cancer cell lines, whereas mesothelin protein expression was confirmed by immunohistochemistry in all 60 resected primary pancreatic adenocarcinomas studied. The adjacent normal pancreas in these 60 cases did not label, or at most only rare benign pancreatic ducts showed weak labeling for mesothelin.

CONCLUSIONS

Mesothelin is a new marker for pancreatic adenocarcinoma identified by gene expression analysis. Mesothelin overexpression in pancreatic adenocarcinoma has potential diagnostic, imaging, and therapeutic implications.

Discovery of new markers of cancer through serial analysis of gene expression: prostate stem cell antigen is overexpressed in pancreatic adenocarcinoma

Serial analysis of gene expression (SAGE) can be used to quantify gene expression in human tissues. Comparison of gene expression levels in neoplastic tissues with those seen in nonneoplastic tissues can, in turn, identify novel tumor markers. Such markers are urgently needed for highly lethal cancers like pancreatic adenocarcinoma, which typically presents at an incurable, advanced stage. The results of SAGE analyses of a large number of neoplastic and nonneoplastic tissues are now available online, facilitating the rapid identification of novel tumor markers. We searched an online SAGE database to identify genes preferentially expressed in pancreatic cancers as compared with normal tissues. SAGE libraries derived from pancreatic adenocarcinomas were compared with SAGE libraries derived from nonneoplastic tissues. Three promising tags were identified. Two of these tags corresponded to genes (lipocalin and trefoil factor 2) previously shown to be overexpressed in pancreatic carcinoma, whereas the third tag corresponded to prostate stem cell antigen (PSCA), a recently discovered gene thought to be largely restricted to prostatic basal cells and prostatic adenocarcinomas. PSCA was expressed in four of the six pancreatic cancer SAGE libraries, but not in the libraries derived from normal pancreatic ductal cells. We confirmed the overexpression of the PSCA mRNA transcript in 14 of 19 pancreatic cancer cell lines by reverse transcription-PCR, and using immunohistochemistry, we demonstrated PSCA protein overexpression in 36 of 60 (60%) primary pancreatic adenocarcinomas. In 59 of 60 cases, the adjacent nonneoplastic pancreas did not label for PSCA. PSCA is a novel tumor marker for pancreatic carcinoma that has potential diagnostic and therapeutic implications. These results establish the validity of analyses of SAGE databases to identify novel tumor markers.

High-throughput drug screening of the DPC4 tumor-suppressor pathway in human pancreatic cancer cells

OBJECTIVE

To screen a library of small chemicals for compounds that activate the DPC4 signal transduction pathway in a human pancreatic cancer cell line.

SUMMARY BACKGROUND DATA

Various tumor-suppressor genes are mutated in all human cancers. Specifically, DPC4 (deleted in pancreatic carcinoma, locus 4 or MADH4/SMAD4) is a tumor-suppressor gene mutated in approximately 50% of human pancreatic adenocarcinomas. DPC4 plays an important role in the well-studied transforming growth factor-beta (TGFbeta) signaling pathway. It would be useful to identify therapies that augment or restore the downstream functions of this critical signal transduction pathway, in hopes that such therapy would have a rational role in anticancer therapy.

METHODS

Using a commercially available plasmid vector with a luciferase reporter gene already incorporated, a DPC4-specific reporter construct was genetically engineered. This was done by inserting six copies of the palindromic Smad binding element (6SBE), which is a DNA binding element specific for DPC4, in front of the minimal promoter in the plasmid. This construct was then stably integrated into the genome of a human pancreatic cancer cell line (PANC-1) that has wild-type DPC4. Several stably transfected clones were tested for basal luciferase expression and inducibility with TGFbeta, which is known to activate the DPC4 signal transduction pathway. A single transfected clone was chosen for the drug screen based on basal luciferase (reporter) expression and TGFbeta inducibility. A systematic screen of the chemical library was then performed, using luciferase activity to detect DPC4 activity and induction of the signaling pathway.

RESULTS

A high-throughput system based on this stably integrated reporter system was used to screen a library of 16,320 random compounds to identify agents that conferred robust augmentation of the DPC4 signal transduction pathway. Of the 16,320 compounds screened, 11 were associated with a 2- to 5-fold induction of luciferase activity, and one with a 12-fold activation. The latter compound was shown to be a novel histone deacetylase inhibitor and was further characterized.

CONCLUSIONS

These results confirm the feasibility of a specific high-throughput reporter system to screen a large compound library in human cells efficiently. The screening identified several compounds capable of augmenting DPC4-specific luciferase reporter activity, and a specific mechanism for one compound was identified. The discovery of such agents will aid our understanding of complex tumor-suppressive signaling pathways and may identify other potential therapeutic targets within this critical signaling pathway. In addition, random drug screening provides an unbiased method for identifying drugs or lead compounds for potential therapeutic use.

Invasion-specific genes in malignancy: serial analysis of gene expression comparisons of primary and passaged cancers

The invasive growth of malignant cells induces an admixture of host reactions including desmoplasia, angiogenesis, and immune reactions Pancreatic cancer has a prominent and characteristic host reaction at the site of primary invasion. To obtain new insights into the process of tumor invasion, we studied global patterns of gene expression using serial analysis of gene expression in pancreatic cancer, with extension to other tumor types. Here we report a cluster of invasion-specific genes in pancreatic and other cancers. This cluster contains genes that derive from distinct components of the host reaction, including some that may be useful as diagnostic markers and therapeutic targets.

Frequent germline deletion polymorphism of chromosomal region 8p12-p21 identified as a recurrent homozygous deletion in human tumors

A number of carcinomas show high frequency of loss of heterozygosity (LOH) at chromosome 8p, suggesting that putative tumor suppressor genes are present in this region. While searching for homozygous deletions in a panel of pancreatic and biliary tumors, we discovered a homozygous deletion at the microsatellite AFMa224wh5 in chromosome region 8p12-p21. We applied a six-step algorithm comprising germline analysis, breakpoint sequencing, population screening, online gene mapping, allelic discrimination of tumor-associated LOH, and family history analysis. The results indicated that the deletion was likely due to a normal 102-bp deletion polymorphism present in nearly 10% of the study population, not likely to involve a recessive cancer-associated gene. Researchers need to be aware that germline insertion/deletion polymorphisms can affect the results of positional cloning efforts in human neoplasms. This problem would be accentuated in studies of cell lines where a paired sample of constitutional DNA is often unavailable.

A novel histone deacetylase inhibitor identified by high-throughput transcriptional screening of a compound library

Libraries of compounds are increasingly becoming commercially available for the use of individual academic laboratories. A high-throughput system based on a stably integrated transcriptional reporter was used to screen a library of random compounds to identify agents that conferred robust augmentation of a signal transduction pathway. A novel histone deacetylase (HDAC) inhibitor, termed scriptaid, conferred the greatest effect, a 12- to 18-fold augmentation. This facilitation of transcriptional events was generally applicable to exogenous gene constructs, including viral and cellular promoters, different cell lines and reporter genes, and stably integrated and transiently introduced sequences. Scriptaid did not interfere with a further induction provided by stimulation of the cognate signal transduction pathway (transforming growth factor beta/Smad4), which implied the functional independence of ligand-stimulated transcriptional activation and histone acetylation states in this system. Additional insights into this and other signal transduction systems are likely to be afforded through the application of compound screening technologies.