RESUMO
Cytotoxicity in the µM range was observed in cancer cell lines treated with N,N,N',N'-tetrabenzyl-4,5-diamino-2-cyclopentenone. Cell cycle analysis on HeLa cells showed a clear G1 phase arrest. A preliminary SAR on structural analogs was performed in order to identify the pharmacophores.
Assuntos
Antineoplásicos/farmacologia , Diaminas/farmacologia , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Diaminas/síntese química , Diaminas/toxicidade , Relação Dose-Resposta a Droga , HumanosRESUMO
Whether neurodevelopmental defects underlie postnatal neuronal death in neurodegeneration is an intriguing hypothesis only recently explored. Here, we focus on spinal muscular atrophy (SMA), a neuromuscular disorder caused by reduced survival of motor neuron (SMN) protein levels leading to spinal motor neuron (MN) loss and muscle wasting. Using the first isogenic patient-derived induced pluripotent stem cell (iPSC) model and a spinal cord organoid (SCO) system, we show that SMA SCOs exhibit abnormal morphological development, reduced expression of early neural progenitor markers, and accelerated expression of MN progenitor and MN markers. Longitudinal single-cell RNA sequencing reveals marked defects in neural stem cell specification and fewer MNs, favoring mesodermal progenitors and muscle cells, a bias also seen in early SMA mouse embryos. Surprisingly, SMN2-to-SMN1 conversion does not fully reverse these developmental abnormalities. These suggest that early neurodevelopmental defects may underlie later MN degeneration, indicating that postnatal SMN-increasing interventions might not completely amend SMA pathology in all patients.
Assuntos
Células-Tronco Pluripotentes Induzidas , Neurônios Motores , Atrofia Muscular Espinal , Organoides , Proteína 1 de Sobrevivência do Neurônio Motor , Proteína 2 de Sobrevivência do Neurônio Motor , Organoides/patologia , Organoides/metabolismo , Humanos , Atrofia Muscular Espinal/patologia , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Neurônios Motores/patologia , Neurônios Motores/metabolismo , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Proteína 2 de Sobrevivência do Neurônio Motor/genética , Proteína 2 de Sobrevivência do Neurônio Motor/metabolismo , Animais , Camundongos , Medula Espinal/patologia , Medula Espinal/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/patologiaRESUMO
A click-type entry into shortened curcuminoids of the diarylpentanoid type has been developed. The reaction is ideally suited to generate non-symmetrical analogues of curcumin, a class of natural products difficult to access but of growing biomedical relevance and special mechanistic interest to investigate the unique binding mode of curcumin to tubulin. Investigation of a series of click diarylpentane curcuminoids and their pyrazole adducts in various cellular tubulin functional assays validated this class of compounds as a novel type of anti-mitotic agents, evidencing structure-activity relationships, and identifying the pyrazole adduct 4k as a promising lead.
Assuntos
Curcumina/análogos & derivados , Moduladores de Tubulina/síntese química , Tubulina (Proteína)/química , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Curcumina/síntese química , Curcumina/toxicidade , Humanos , Pirazóis/química , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/toxicidadeRESUMO
The research of estrogen receptor (ER) ligands has benefited in the last decade from the implementation of combinatorial chemistry. The general pharmacophore has been identified and subsequently a multitude of compounds have been synthesized. Surprisingly, up to now simple amides have not been taken into consideration. Here we show that amides resulting from the condensation of hydroxybenzoic acids with aminophenols result in compounds retaining the pharmacophore structure of an ER ligand with a clear estrogenic activity.
Assuntos
Benzamidas/química , Técnicas de Química Sintética/métodos , Receptores de Estrogênio/agonistas , Aminofenóis/química , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Hidroxibenzoatos/química , Bibliotecas de Moléculas Pequenas , Relação Estrutura-AtividadeRESUMO
Calcium is a universal signal, and its capacity to encode intracellular messages via spatial, temporal and amplitude characteristics allows it to participate in most cellular events. In a specific context, calcium plays a pivotal role in migration, although its role has not been elucidated fully. By using immortalized gonadotropin-releasing hormone-secreting neurons (GN11), we have now investigated the role of TRPV4, a member of the vanilloid family of Ca(2+) channels, in neuronal migration. Our results show that TRPV4 channels are present and functional in GN11 cells and their localization is polarized and enriched in lamellipodial structures. TRPV4 activation leads to a retraction of the lamellipodia and to a decrease in migratory behaviour; moreover cells migrate slower and in a more random manner. We therefore provide evidence for a new regulation of gonadotropin-releasing hormone neurons and a new role for calcium at the leading edge of migratory cells.
Assuntos
Inibição de Migração Celular/fisiologia , Células Neuroendócrinas/citologia , Células Neuroendócrinas/metabolismo , Canais de Cátion TRPV/metabolismo , Animais , Linhagem Celular Transformada , Movimento Celular/fisiologia , Regulação para Baixo/fisiologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Gravidez , Ratos , Ratos Sprague-DawleyRESUMO
In the chalcone scaffold, it is thought that the double bond is an important structural linker but it is likely not essential for the interaction with tubulin. Yet, it may be a potential site of metabolic degradation and interaction with biological nucleophiles. In this letter, we have replaced this olefinic portion of chalcones with two metabolically stable and chemically inert heterocyclic rings, namely triazole or tetrazole. Yet, our biologic data suggest that, unlike in other antitubulinic structures, the olephinic ring might not be merely a structural linker.
Assuntos
Chalconas/química , Chalconas/farmacologia , Tetrazóis/química , Tetrazóis/farmacologia , Triazóis/química , Triazóis/farmacologia , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Chalconas/síntese química , Humanos , Modelos Moleculares , Neuroblastoma/tratamento farmacológico , Tetrazóis/síntese química , Triazóis/síntese química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/síntese químicaRESUMO
In a program aimed at discovering novel protein kinase inhibitors, a convenient synthesis of 3,8-diaminoimidazo[1,2-a]pyrazines has been developed exploiting the isocyanide-based multicomponent Blackburn reaction, followed by a nucleophilic aromatic substitution with ammonia or primary and secondary amines. The potential of the reported scaffold is strengthened by the inhibition of STAT5-dependent transcription displayed by four of the synthesized compounds.
Assuntos
Imidazóis/síntese química , Inibidores de Proteínas Quinases/síntese química , Pirazinas/síntese química , Imidazóis/química , Estrutura Molecular , Inibidores de Proteínas Quinases/química , Pirazinas/química , EstereoisomerismoRESUMO
Synapses and nuclei are connected by bidirectional communication mechanisms that enable information transfer encoded by macromolecules. Here, we identified RNF10 as a novel synaptonuclear protein messenger. RNF10 is activated by calcium signals at the postsynaptic compartment and elicits discrete changes at the transcriptional level. RNF10 is enriched at the excitatory synapse where it associates with the GluN2A subunit of NMDA receptors (NMDARs). Activation of synaptic GluN2A-containing NMDARs and induction of long term potentiation (LTP) lead to the translocation of RNF10 from dendritic segments and dendritic spines to the nucleus. In particular, we provide evidence for importin-dependent long-distance transport from synapto-dendritic compartments to the nucleus. Notably, RNF10 silencing prevents the maintenance of LTP as well as LTP-dependent structural modifications of dendritic spines.
Assuntos
Proteínas de Transporte/metabolismo , Hipocampo/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Sinapses/fisiologia , Animais , Núcleo Celular/metabolismo , Transporte Proteico , RatosRESUMO
The aim of this study was to characterize carbonic anhydrase II (CA2), as novel estrogen responsive gene, towards its usefulness to elucidate the molecular mechanisms of phytoestrogen action. Effects of estradiol-17beta (E2), and the phytoestrogens genistein (Gen), daidzein (Dai), as well as 8-prenylnaringenin (8PN) on CA2 mRNA expression were investigated in vivo in the uterus and liver of Wistar rats, and in vitro in Fe33 hepatoma cells. Relative amounts of mRNA levels of CA2 were measured by real-time RT-PCR. In vivo CA2 expression in uterus and liver is down-regulated by estrogen in time dependent manner with the most pronounced effect detectable 72 h after treatment. Treatment with Gen results in a slight down-regulation of CA2 expression in the uterus. In liver a response to Gen is detectable only after 7 h, where the expression of the gene is down-regulated to 60%. Treatment with Dai and 8PN for 72 h results in a slight down-regulation of CA2 in both tissues. In contrast in Fe 33 cells CA2 gene expression was up-regulated in response to the treatment with E2 for 7 h. In summary, we could demonstrate that the modulation of CA2 gene expression following treatment with E2 and Gen in rat uterus is comparable to the uterotrophic response of these substances, but with an inverted pattern. Remarkably, of all phytoestrogens 8PN exhibited the strongest uterotrophic response but only induced a very faint decrease of CA2 expression. In addition, we provide the first pieces of evidence that 8PN, like Gen and Dai, cannot be considered as a pure agonist. In conclusion, CA2 shows estrogen sensitivity not only in both tissues studied, but also in many others. Further, it exhibits a differential sensitivity thereby being capable to discriminate between different molecular qualities of phytoestrogens, like demonstrated for Gen and 8PN.
Assuntos
Anidrase Carbônica II/genética , Expressão Gênica/efeitos dos fármacos , Fígado/enzimologia , Fitoestrógenos/farmacologia , Útero/enzimologia , Animais , Regulação para Baixo , Estradiol/farmacologia , Feminino , Flavanonas/farmacologia , Genisteína/farmacologia , Isoflavonas/farmacologia , Ratos , Células Tumorais Cultivadas , Regulação para CimaRESUMO
High plasma levels of nicotinamide phosphoribosyltransferase (NAMPT), traditionally considered an intracellular enzyme with a key role in NAD synthesis, have been reported in several oncological, inflammatory and metabolic diseases. We now show that eNAMPT can be actively released by melanoma cells in vitro. We analysed the mechanisms of its release, and we found both classical and non-classical pathway involvement. eNAMPT released by melanoma cells, in our hands, has paracrine and autocrine effects: it activates MAPK, AKT and NF-κB pathways and increases colony formation in anchorage-independent conditions. eNAMPT also induces M1 polarization in human monocytes. Last, we demonstrate, for the first time in any cancer type, that eNAMPT levels in plasma of tumour-bearing mice increase and that this increase can be reconducted to the tumour itself. This provides an important cue on previous observations that eNAMPT is increased in patients with cancer. Moreover, silencing NAMPT in melanoma cells leads to a reduction in the tumour growth rate. Our findings extend the basis to consider eNAMPT as a cytokine involved in tumour progression.
Assuntos
Citocinas/metabolismo , Melanoma/enzimologia , Nicotinamida Fosforribosiltransferase/metabolismo , Neoplasias Cutâneas/enzimologia , Animais , Comunicação Autócrina/efeitos dos fármacos , Hipóxia Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Citocinas/sangue , Espaço Extracelular/enzimologia , Humanos , Peróxido de Hidrogênio/farmacologia , Melanoma/patologia , Camundongos Endogâmicos C57BL , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Nicotinamida Fosforribosiltransferase/sangue , Comunicação Parácrina/efeitos dos fármacos , Vesículas Secretórias/metabolismo , Neoplasias Cutâneas/patologiaRESUMO
In this study the ability of the phytoestrogen genistein (GEN) to regulate proliferation in the rat uterine tissue and the associated molecular mechanisms were investigated in a dose and time dependent manner. A single administration of GEN induced a rapid increase of the uterine weight during the first 24 h. In contrast to E2, treatment with GEN for 3 days did not result in a further increase of the uterine weight. GEN only marginally effected the thickness of the uterine epithelium and the expression of epithelial proliferating cell nuclear antigen (PCNA). Whereas, estrogen sensitive genes were modulated significantly, the expression of key genes involved in the regulation of proliferation (PCNA, ERalpha /ERbeta ratio) remained unaffected by GEN. Our results indicate that GEN has only a limited ability to activate molecular mechanisms involved in the induction of proliferation whereas estrogen sensitive genes are induced in a estrogen like manner.
Assuntos
Estradiol/farmacologia , Expressão Gênica/efeitos dos fármacos , Genisteína/farmacologia , Fitoestrógenos/farmacologia , Útero/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Epitélio/imunologia , Feminino , Antígeno Nuclear de Célula em Proliferação/análise , Antígeno Nuclear de Célula em Proliferação/genética , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Receptores de Esteroides/análise , Receptores de Esteroides/genética , Útero/citologia , Útero/imunologiaRESUMO
It has been shown that some chalcones are able to inhibit tubulin polymerization, giving cytotoxicity and destruction of tumoral vasculature. A library of 180 novel chalcone analogs has been synthesized via click chemistry and screened for their cytotoxicity and tubulin assembly inhibition. 10 out 180 click chalcones displayed low micromolar cytotoxicity but only compound Nf depicted antitubulin activity. While Nf displayed only micromolar potency this result shows click-chalcones may be anti-tubulin agents and validate this strategy to search for novel active chemical entities.
Assuntos
Chalconas/síntese química , Moduladores de Tubulina/síntese química , Tubulina (Proteína)/metabolismo , Linhagem Celular Tumoral , Chalconas/química , Chalconas/farmacologia , Química Click , Humanos , Tubulina (Proteína)/química , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologiaRESUMO
Tubulin inhibition represents an established target in the field of anticancer research, and over the last 20 years, an intensive search for new antimicrotubule agents has occurred. Indeed, in silico models have been presented that might aid the discovery of novel agents. Among these, a 7-point pharmacophore model has been recently proposed. As a formal proof of this model, we carried out a ligand-based virtual screening on the colchicine-binding site. In vitro testing demonstrated that two compounds displayed a cytotoxic profile on neuroblastoma cancer cells (SH-SY5H) and one had an antitubulinic profile.
Assuntos
Colchicina/química , Bases de Dados Factuais , Modelos Moleculares , Moduladores de Tubulina/química , Tubulina (Proteína)/química , Sítios de Ligação , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Ligantes , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/farmacologiaRESUMO
Combretastatin A-4 (CA-4) is a potent tubulin depolymerizing agent able to inhibit tumor growth and with antivascular effects. Although it is in clinical trials, the search for novel analogues that may display better/different features is still ongoing. In this manuscript we describe the synthesis of novel constrained analogues of CA-4 obtained in only two synthetic steps exploiting a regioselective Suzuki coupling of dihalogenated heteroaromatic and alicyclic compounds. All the compounds synthesized have been evaluated for cytotoxicity and for their ability to inhibit tubulin assembly. One of them, 38, displayed low nanomolar cytotoxicity and proved to have a pharmacodynamic profile similar to that of CA-4 and a better pharmacokinetic profile, but most important of all, this synthetic strategy may pave the way for the easy and rapid generation of novel rigid analogues of combretastatins.
Assuntos
Antineoplásicos/síntese química , Furanos/síntese química , Estilbenos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Colchicina/química , Ensaios de Seleção de Medicamentos Antitumorais , Furanos/química , Furanos/farmacologia , Humanos , Técnicas In Vitro , Concentração Inibidora 50 , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Estereoisomerismo , Estilbenos/química , Estilbenos/farmacologia , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologiaRESUMO
Tropisetron, a selective 5-HT(3) receptor antagonist, is widely used to counteract chemotherapy-induced emesis. Some investigations describe disparate effects including immunomodulatory properties for tropisetron which may be mediated through immunophilin-calcineurin pathway. Calcineurin, a phosphatase involved in immune system signaling, modulates expression of several genes, such as Cannabinoid type one (CB(1)) receptors. On the quest for its underlying mechanisms of action, this study aimed to investigate the effect of tropisetron on calcineurin activity and CB(1) receptor expression and function in cerebellar granule neurons (CGNs). The rat pup CGNs were used as highly calcineurin-rich and devoid of 5-HT(3) receptor neuronal cells. Calcineurin activity was assessed in CGNs treated with tropisetron or the congener granisetron at 1nM-10µM concentrations. Moreover, cannabinoid CB(1) receptor expression at mRNA and protein levels were investigated by real time PCR and western blotting, respectively and its functionality studied by measuring the secondary messenger cAMP in CGNs receiving tropisetron or granisetron. Results indicate that tropisetron, but not granisetron, significantly inhibits the phosphatase activity of calcineurin, over-expresses the CB(1) receptors at both transcriptional and protein levels, and reduces cAMP content. Our investigation shows that tropisetron targets calcineurin in a receptor-independent fashion. Tropisetron-induced CB(1) receptor up-regulation might underlie many pharmacological aspects of tropisetron unrelated to anti-emesis.
Assuntos
Calcineurina/metabolismo , Indóis/farmacologia , Neurônios/metabolismo , Receptor CB1 de Canabinoide/biossíntese , Antagonistas da Serotonina/farmacologia , Animais , Antieméticos/farmacologia , Western Blotting , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cerebelo/metabolismo , Expressão Gênica/efeitos dos fármacos , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tropizetrona , Regulação para CimaRESUMO
The inhibition of NAD synthesis or salvage pathways has been proposed as a novel target for antitumoral drugs. Two molecules with this mechanism of action are at present undergoing clinical trials. In searching for similar novel molecules, we exploited copper-catalyzed [3 + 2] cycloaddition between azides and alkynes (click chemistry) to synthesize 185 novel analogues. The most promising compound displays an IC(50) for cytotoxicity in vitro of 3.8 +/- 0.3 nM and an IC(50) for NAD depletion of 3.0 +/- 0.4 nM. Herein, we strengthen previous data suggesting that this class of compounds induces autophagic cell death. In addition to characterizing this compound and providing a rationale via molecular docking, we reinforce the excellent potential of click chemistry for rapidly generating structure-activity relationships and for drug screening.
Assuntos
Azidas/química , Inibidores Enzimáticos/síntese química , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Alcinos/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Autofagia , Azidas/farmacologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Humanos , Concentração Inibidora 50 , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
Pluripotent embryonic stem cells (ESCs) maintain self-renewal while ensuring a rapid response to differentiation cues. The identification of genes maintaining ESC identity is important to develop these cells for their potential therapeutic use. Here we report a genome-scale RNAi screen for a global survey of genes affecting ESC identity via alteration of Oct4 expression. Factors with the strongest effect on Oct4 expression included components of the Paf1 complex, a protein complex associated with RNA polymerase II. Using a combination of proteomics, expression profiling, and chromatin immunoprecipitation, we demonstrate that the Paf1C binds to promoters of key pluripotency genes, where it is required to maintain a transcriptionally active chromatin structure. The Paf1C is developmentally regulated and blocks ESC differentiation upon overexpression, and the knockdown in ESCs causes expression changes similar to Oct4 or Nanog depletions. We propose that the Paf1C plays an important role in maintaining ESC identity.
Assuntos
Células-Tronco Embrionárias/citologia , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Interferência de RNA , Fatores de Transcrição/metabolismo , Animais , Linhagem da Célula , Proliferação de Células , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Células-Tronco Embrionárias/metabolismo , Redes Reguladoras de Genes , Genoma , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Camundongos , Proteína Homeobox Nanog , Proteínas Nucleares/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , RNA Polimerase II/genética , RNA Polimerase II/metabolismoAssuntos
Melanoma/enzimologia , Melanoma/patologia , Nicotinamida Fosforribosiltransferase/metabolismo , Neoplasias Cutâneas/enzimologia , Neoplasias Cutâneas/patologia , Acrilamidas/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Melanoma/tratamento farmacológico , Melanoma/genética , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/genética , Piperidinas/farmacologia , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genéticaRESUMO
RNA interference (RNAi) has become an important technique for loss-of-gene-function studies in mammalian cells. To achieve reliable results in an RNAi experiment, efficient and specific silencing triggers are required. Here we present genome-wide data sets for the production of endoribonuclease-prepared short interfering RNAs (esiRNAs) for human, mouse and rat. We used an algorithm to predict the optimal region for esiRNA synthesis for every protein-coding gene of these three species. We created a database, RiDDLE, for retrieval of target sequences and primer information. To test this in silico resource experimentally, we generated 16,242 esiRNAs that can be used for RNAi screening in human cells. Comparative analyses with chemically synthesized siRNAs demonstrated a high silencing efficacy of esiRNAs and a 12-fold reduction of downregulated off-target transcripts as detected by microarray analysis. Hence, the presented esiRNA libraries offer an efficient, cost-effective and specific alternative to presently available mammalian RNAi resources.
Assuntos
Endorribonucleases/genética , Biblioteca Genômica , Genômica/métodos , Interferência de RNA , RNA Interferente Pequeno/genética , Animais , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Transcrição Gênica , Transfecção , Regiões não Traduzidas , Interface Usuário-ComputadorRESUMO
The potential estrogenic activity of 8-prenylnaringenin has been investigated using several in vitro test systems. 8-Prenylnaringenin is a natural secondary product of the female blossoms of hops. The aim of the present study was to characterize 8-prenylnaringenin for its estrogenic effects in vivo. A three day uterotrophic assay was carried out on ovariectomized young female rats. A single dose of 8-prenylnaringenin (10 mg/day/kg body mass) was administered subcutaneously. 17beta-Estradiol (0.03 mg/day/kg body mass; subcutaneous administration) was used as a positive control. Uterine wet weight, endometrial and vaginal epithelial height were determined by histological methods. Gene expression in uterus and in liver was assessed using realtime RT-PCR. Both estradiol and 8-prenylnaringenin significantly stimulated uterine wet weight accompanied by a proliferative response. The three day treatment resulted in a statistically significant increase of the uterine epithelial height as well as of the vaginal epithelial height, the latter being the more sensitive parameter. In the uterus of ovariectomized animals estrogen receptor-alpha and clusterin gene expression were down regulated following treatment with estradiol, whereas expression of complement C3 was up-regulated. In response to treatment with 8-prenylnaringenin the same gene expression pattern was detectable, but less pronounced. The levels of estrogen receptor-alpha mRNA in rat liver were very low and therefore could not be quantitatively assessed. Like in the uterine tissue, estradiol down regulated clusterin expression. The response to 8-prenylnaringenin was weaker but still significant. Conversely, 8-prenylnaringenin was found to be more potent than estradiol in inducing expression of IGFBP-1. In summary, the multiparametric assessment of the estrogenic activity of 8-prenylnaringenin provides overwhelming evidence that 8-prenylnaringenin has largely to be regarded as a pure estrogen agonist and is therefore a questionable candidate molecule for hormone replacement therapy.