RESUMEN

BACKGROUND: Long-acting reversible contraceptives are recommended first-line contraception; however, intrauterine device (IUD) uptake remains low in Australia. OBJECTIVES: To describe the outcomes of an independent evaluation of the General Practitioner IUD Insertion Network (GPIIN), a project designed to address access barriers through formalized referral pathways between general practitioners (GPs) inserting IUDs and noninserters. METHODS: An independent qualitative pragmatic inductive evaluation, involving 14 in-depth interviews with GPIIN members, was conducted 18 months post-GPIIN implementation in 2 Australian jurisdictions to identify and explore critical success factors and limitations of the model. RESULTS: Local GP-to-GP IUD referral networks were considered a useful model to assist affordable and timely IUD access, improve noninserters' IUD knowledge and inserters' reflection on best practice. However, pathway simplification is needed to determine optimal integration of the concept into pragmatic GP-to-GP referral arrangements. CONCLUSIONS: GPIIN provides an opportunity to improve IUD access in Primary Health Care. Further consideration of organizations best positioned and resourced to facilitate sustainable delivery and coordination is necessary.

Asunto(s)

Medicina General , Dispositivos Intrauterinos , Femenino , Humanos , Australia , Anticoncepción , Derivación y Consulta

RESUMEN

Reliably predicting in vivo efficacy from in vitro data would facilitate drug development by reducing animal usage and guiding drug dosing in human clinical trials. However, such prediction remains challenging. Here, we built a quantitative pharmacokinetic/pharmacodynamic (PK/PD) mathematical model capable of predicting in vivo efficacy in animal xenograft models of tumor growth while trained almost exclusively on in vitro cell culture data sets. We studied a chemical inhibitor of LSD1 (ORY-1001), a lysine-specific histone demethylase enzyme with epigenetic function, and drug-induced regulation of target engagement, biomarker levels, and tumor cell growth across multiple doses administered in a pulsed and continuous fashion. A PK model of unbound plasma drug concentration was linked to the in vitro PD model, which enabled the prediction of in vivo tumor growth dynamics across a range of drug doses and regimens. Remarkably, only a change in a single parameter-the one controlling intrinsic cell/tumor growth in the absence of drug-was needed to scale the PD model from the in vitro to in vivo setting. These findings create a framework for using in vitro data to predict in vivo drug efficacy with clear benefits to reducing animal usage while enabling the collection of dense time course and dose response data in a highly controlled in vitro environment.

Asunto(s)

Antineoplásicos/farmacología , Epigénesis Genética/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Modelos Biológicos , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Metilación de ADN/efectos de los fármacos , Conjuntos de Datos como Asunto , Histona Demetilasas/antagonistas & inhibidores , Histona Demetilasas/metabolismo , Humanos , Ratones , Neoplasias/genética , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Small cell lung cancer (SCLC) is a recalcitrant, aggressive neuroendocrine-type cancer for which little change to first-line standard-of-care treatment has occurred within the last few decades. Unlike nonsmall cell lung cancer (NSCLC), SCLC harbors few actionable mutations for therapeutic intervention. Lysine-specific histone demethylase 1A (LSD1 also known as KDM1A) inhibitors were previously shown to have selective activity in SCLC models, but the underlying mechanism was elusive. Here, we found that exposure to the selective LSD1 inhibitor ORY-1001 activated the NOTCH pathway, resulting in the suppression of the transcription factor ASCL1 and the repression of SCLC tumorigenesis. Our analyses revealed that LSD1 bound to the NOTCH1 locus, thereby suppressing NOTCH1 expression and downstream signaling. Reactivation of NOTCH signaling with the LSD1 inhibitor reduced the expression of ASCL1 and neuroendocrine cell lineage genes. Knockdown studies confirmed the pharmacological inhibitor-based results. In vivo, sensitivity to LSD1 inhibition in SCLC patient-derived xenograft (PDX) models correlated with the extent of consequential NOTCH pathway activation and repression of a neuroendocrine phenotype. Complete and durable tumor regression occurred with ORY-1001-induced NOTCH activation in a chemoresistant PDX model. Our findings reveal how LSD1 inhibitors function in this tumor and support their potential as a new and targeted therapy for SCLC.

Asunto(s)

Inhibidores Enzimáticos/uso terapéutico , Histona Demetilasas/antagonistas & inhibidores , Neoplasias Pulmonares/tratamiento farmacológico , Receptores Notch/metabolismo , Transducción de Señal/efectos de los fármacos , Carcinoma Pulmonar de Células Pequeñas/tratamiento farmacológico , Ensayos Antitumor por Modelo de Xenoinjerto , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Histona Demetilasas/genética , Histona Demetilasas/metabolismo , Humanos , Estimación de Kaplan-Meier , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Receptores Notch/genética , Transducción de Señal/genética , Carcinoma Pulmonar de Células Pequeñas/genética , Carcinoma Pulmonar de Células Pequeñas/metabolismo , Carga Tumoral/efectos de los fármacos , Carga Tumoral/genética

RESUMEN

Antibody-drug conjugates (ADCs) represent a promising therapeutic modality for the clinical management of cancer. The recent approvals of brentuximab vedotin and ado-trastuzumab emtansine plus emerging data for many molecules in clinical trials highlight the potential for ADCs to offer new therapeutic options for patients. Currently, more than 30 ADCs are being evaluated in early- or late-stage clinical trials. Accordingly, much has been done to refine and transform the early-generation ADCs to the highly effective products that we now have in clinical development. These changes include a better understanding of optimal target selection, advances in antibody engineering, improvements in linker/payload conjugation strategies, and the generation of highly potent ADC payloads. In this review, we detail the current status of ADCs in both preclinical and clinical development, highlight technological advancements in ADC development, and speculate towards the future of this targeted therapeutic platform.

Asunto(s)

Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Antineoplásicos/inmunología , Antineoplásicos/uso terapéutico , Inmunoconjugados/uso terapéutico , Neoplasias/tratamiento farmacológico , Animales , Anticuerpos Monoclonales Humanizados/inmunología , Antineoplásicos/inmunología , Sistemas de Liberación de Medicamentos , Humanos , Inmunoconjugados/inmunología

RESUMEN

PKN3 is an AGC-family protein kinase implicated in growth of metastatic prostate cancer cells with phosphoinositide 3-kinase pathway deregulation. The molecular mechanism, however, by which PKN3 contributes to malignant growth and tumorigenesis is not well understood. Using orthotopic mouse tumor models, we now show that inducible knockdown of PKN3 protein not only blocks metastasis, but also impairs primary prostate and breast tumor growth. Correspondingly, overexpression of exogenous PKN3 in breast cancer cells further increases their malignant behavior and invasiveness in-vitro. Mechanistically, we demonstrate that PKN3 physically interacts with Rho-family GTPases, and preferentially with RhoC, a known mediator of tumor invasion and metastasis in epithelial cancers. Likewise, RhoC predominantly associates with PKN3 compared to its closely related PKN family members. Unlike the majority of Rho GTPases and PKN molecules, which are ubiquitously expressed, both PKN3 and RhoC show limited expression in normal tissues and become upregulated in late-stage malignancies. Since PKN3 catalytic activity is increased in the presence of Rho GTPases, the co-expression and preferential interaction of PKN3 and RhoC in tumor cells are functionally relevant. Our findings provide novel insight into the regulation and function of PKN3 and suggest that the PKN3-RhoC complex represents an attractive therapeutic target in late-stage malignancies.

Asunto(s)

Neoplasias de la Próstata/metabolismo , Proteína Quinasa C/metabolismo , Proteínas ras/metabolismo , Animales , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Línea Celular Tumoral , Núcleo Celular/metabolismo , Doxiciclina/uso terapéutico , Técnica del Anticuerpo Fluorescente , Inmunoprecipitación , Masculino , Ratones , Metástasis de la Neoplasia/genética , Neoplasias de la Próstata/patología , Unión Proteica , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/genética , ARN Interferente Pequeño , Proteínas ras/genética , Proteína rhoC de Unión a GTP

RESUMEN

The tumor suppressor von Hippel-Lindau protein (pVHL) is critical for cellular molecular oxygen sensing, acting to target degradation of the hypoxia-inducible factor alpha transcription factor subunits under normoxic conditions. We have found that independent of its function in regulating hypoxic response, the VHL gene plays a critical role in embryonic endothelium development through regulation of vascular extracellular matrix assembly. We created mice lacking the VHL gene in endothelial cells; these conditional null mice died at the same stage as homozygous VHL-null mice, with similar vascular developmental defects. These included defective vasculogenesis in the placental labyrinth, a collapsed endocardium, and impaired vessel network patterning. The defects in embryonic vascularization were correlated with a diminished vascular fibronectin deposition in vivo and defective endothelial extracellular fibronectin assembly in vitro. We found that the impaired migration and adhesion of VHL-null endothelial cells can be partially rescued by the addition of back exogenous fibronectin, which indicates that pVHL regulation of fibronectin deposition plays an important functional role in vascular patterning and maintenance of vascular integrity.

Asunto(s)

Células Endoteliales/metabolismo , Matriz Extracelular/metabolismo , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Animales , Permeabilidad Capilar , Adhesión Celular , Movimiento Celular , Células Cultivadas , Dilatación , Embrión de Mamíferos/anomalías , Embrión de Mamíferos/anatomía & histología , Endocardio/patología , Células Endoteliales/citología , Células Endoteliales/patología , Muerte Fetal , Fibronectinas/metabolismo , Regulación de la Expresión Génica , Edad Gestacional , Subunidad alfa del Factor 1 Inducible por Hipoxia/deficiencia , Ratones , Ratones Noqueados , Miocardio , Neovascularización Patológica , Placenta/citología , Placenta/patología , Conducto Vitelino/citología , Conducto Vitelino/metabolismo , Conducto Vitelino/patología , Saco Vitelino/anomalías , Saco Vitelino/irrigación sanguínea

RESUMEN

Placental development initially occurs in a low-oxygen (O2) or hypoxic environment. In this report we show that two hypoxia-inducible factors (HIFs), HIF1alpha and HIF2alpha, are essential for determining murine placental cell fates. HIF is a heterodimer composed of HIFalpha and HIFbeta (ARNT) subunits. Placentas from Arnt-/- and Hif1alpha-/- Hif2alpha-/- embryos exhibit defective placental vascularization and aberrant cell fate adoption. HIF regulation of Mash2 promotes spongiotrophoblast differentiation, a prerequisite for trophoblast giant cell differentiation. In the absence of Arnt or Hifalpha, trophoblast stem cells fail to generate these cell types and become labyrinthine trophoblasts instead. Therefore, HIF mediates placental morphogenesis, angiogenesis, and cell fate decisions, demonstrating that O2 tension is a critical regulator of trophoblast lineage determination. This novel genetic approach provides new insights into the role of O2 tension in the development of life-threatening pregnancy-related diseases such as preeclampsia.

Asunto(s)

Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Diferenciación Celular , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Trofoblastos/citología , Trofoblastos/metabolismo , Animales , Translocador Nuclear del Receptor de Aril Hidrocarburo/deficiencia , Translocador Nuclear del Receptor de Aril Hidrocarburo/genética , Translocador Nuclear del Receptor de Aril Hidrocarburo/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/deficiencia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Femenino , Células Gigantes/citología , Células Gigantes/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/deficiencia , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Ratones , Ratones Noqueados , Fenotipo , Placenta/anomalías , Placenta/irrigación sanguínea , Placenta/citología , Placenta/metabolismo

RESUMEN

Inactivating mutations within the von Hippel-Lindau (VHL) tumor suppressor gene predispose patients to develop a variety of highly vascularized tumors. pVHL targets alpha subunits of the heterodimeric transcription factor hypoxia-inducible factor (HIF), a critical regulator of energy metabolism, angiogenesis, hematopoiesis, and oxygen (O(2)) delivery, for ubiquitin-mediated degradation in an O(2)-dependent manner. To investigate the role of Vhl in cellular proliferation and tumorigenesis, we utilized mouse embryonic fibroblasts (MEFs), a common tool for analyzing cell cycle regulation, and generated Vhl(-)(/)(-) MEF-derived fibrosarcomas. Surprisingly, growth of both Vhl(-)(/)(-) MEFs and fibrosarcomas was impaired, although tumor vascularity was increased. Decreased proliferation of Vhl(-)(/)(-) MEFs was correlated with an overexpression of cyclin kinase inhibitors (CKIs) p21 and p27. The transcription of p21 and p27 is inhibited by c-Myc; therefore, the induction of CKIs was attributed to the ability of HIF to antagonize c-Myc activity. Indeed, p21 mRNA levels were elevated under normoxia in Vhl(-)(/)(-) MEFs, while c-Myc transcriptional activity was markedly reduced. Gene silencing of HIF-1alpha by small interfering RNA reduced p21 and p27 protein and mRNA levels in Vhl(-)(/)(-) MEFs. The induction of p21 and p27, mediated by constitutive activation of the HIF pathway, provides a mechanism for the decreased proliferation rates of Vhl(-)(/)(-) MEFs and fibrosarcomas. These results demonstrate that a loss of pVHL can induce growth arrest in certain cells types, which suggests that additional genetic mutations are necessary for VHL-associated tumorigenesis.

Asunto(s)

Proteínas de Ciclo Celular/metabolismo , Fibrosarcoma/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Proteínas Supresoras de Tumor/fisiología , Ubiquitina-Proteína Ligasas/fisiología , Animales , Apoptosis , Ciclo Celular/genética , Ciclo Celular/fisiología , Proteínas de Ciclo Celular/genética , Proliferación Celular , Inhibidor p21 de las Quinasas Dependientes de la Ciclina , Inhibidor p27 de las Quinasas Dependientes de la Ciclina , Embrión de Mamíferos/citología , Femenino , Fibroblastos/metabolismo , Fibrosarcoma/genética , Fibrosarcoma/patología , Silenciador del Gen , Subunidad alfa del Factor 1 Inducible por Hipoxia , Ratones , Ratones Mutantes , Mutación , Proteínas Proto-Oncogénicas c-myc/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/farmacología , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética , Activación Transcripcional , Proteínas Supresoras de Tumor/genética , Ubiquitina-Proteína Ligasas/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau

RESUMEN

Inactivation of the von Hippel-Lindau (VHL) gene is associated with the development of highly vascularized tumors. pVHL targets the alpha subunits of hypoxia inducible factor (HIF) for ubiquitin-mediated degradation in an oxygen-dependent manner. Although pVHL-deficient tumor cell lines demonstrate constitutive stabilization and activation of HIF, it has yet to be shown that loss of murine Vhl alone is sufficient to dysregulate HIF. We utilized a genetic approach to demonstrate that loss of Vhl is sufficient not only to stabilize HIF-alpha subunits under normoxia, but also fully activate HIF-mediated responses. These studies have implications for the hierarchy of signaling events leading to HIF stabilization, nuclear translocation, and target gene expression. We further demonstrate that loss of murine Vhl does not promote teratocarcinoma growth, indicating that other genetic changes must occur to facilitate Vhl-mediated tumorigenesis.

Asunto(s)

Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Ligasas/genética , Neoplasias Experimentales/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factores de Transcripción , Proteínas Supresoras de Tumor , Ubiquitina-Proteína Ligasas , Enfermedad de von Hippel-Lindau/genética , Animales , Apoptosis/genética , Regulación Neoplásica de la Expresión Génica , Factor 1 Inducible por Hipoxia , Subunidad alfa del Factor 1 Inducible por Hipoxia , Ligasas/deficiencia , Ratones , Neoplasias Experimentales/irrigación sanguínea , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Teratocarcinoma/irrigación sanguínea , Teratocarcinoma/metabolismo , Teratocarcinoma/patología , Células Tumorales Cultivadas , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau