PTHrP treatment of colon cancer cells promotes tumor associated-angiogenesis by the effect of VEGF

We showed that Parathyroid Hormone-related Peptide (PTHrP) induces proliferation, migration, survival and chemoresistance via MAPKs and PI3K/AKT pathways in colorectal cancer (CRC) cells. The objective of this study was to investigate if PTHrP is also involved in tumor angiogenesis. PTHrP increased VEGF expression and the number of structures with characteristics of neoformed vessels in xenografts tumor. Also, PTHrP increased mRNA levels of VEGF, HIF-1α and MMP-9 via ERK1/2 and PI3K/Akt pathways in Caco-2 and HCT116 cells. Tumor conditioned media (TCMs) from both cell lines treated with PTHrP increases the number of cells, the migration and the tube formation in the endothelial HMEC-1 cells, whereas the neutralizing antibody against VEGF diminished this response. In contrast, PTHrP by direct treatment only increased ERK1/2 phosphorylation and the HMEC-1 cells number. These results provide the first evidence related to the mode of action of PTHrP that leads to its proangiogenic effects in the CRC.Fil: Calvo, Natalia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Carriere, Pedro Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Martín, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Gigola, Graciela. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Gentili, Claudia Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentin

Mecanismos de acción del análogo tumoral de la hormona paratiroidea (PTHrP) en células de cáncer de colon humano

La hormona paratiroidea (PTH) es un importante mediador de la remodelación ósea y actúa junto al calcitriol (1α,25(OH)2vitamina D3), como regulador esencial de la homeostasis del calcio y fósforo. El péptido relacionado con la hormona paratiroidea (PTHrP) es una poli hormona que tiene un papel importante en el desarrollo del feto y en la homeostasis de tejidos adultos actuando principalmente en forma parácrina. Puede ser expresada y secretada por varios tumores y es responsable de la hipercalcemia humoral maligna, siendo éste un signo de mal pronóstico en las neoplasias malignas. Al momento de comenzar este Trabajo de Tesis había poca información acerca del rol de PTHrP actuando como factor parácrino sobre células derivadas del cáncer colorrectal (CCR). En el presente Trabajo se evidencia que PTHrP es capaz de inducir un aumento en la proliferación celular de dos líneas celulares derivadas de CCR, las células Caco-2 y las células HCT116. Además, este efecto inducido por la hormona está modulado por las cascadas de señalización PKC, Src, Akt, ERK MAPK y β-catenina. Se observó que en las células tumorales intestinales la hormona mediante ERK MAPK desencadena el aumento de la expresión y/o activación por fosforilación de CREB/ATF-1, c-myc y ciclina D1, que son moléculas relevantes en la proliferación celular. Acorde con lo observado in vitro, los experimentos desarrollados en el modelo murino revelan que la administración continua de la hormona en forma intra-tumoral modula la expresión de los marcadores claves en la progresión del CCR ERK, ciclina D1 y CREB/ATF-1. Tanto las células tumorales intestinales normales como aquellas que sobre-expresan PTHrP responden a la acción de las hormonas calciotrópicas PTH y calcitriol, al menos a nivel transcripcional, disminuyendo la expresión de PTHrP. PTHrP no sólo favorece la activación de vías mitogénicas y la proliferación de las células Caco-2 y HCT116 sino que también es capaz de disminuir la sensibilidad de estas células al Irinotecán (que es una droga comúnmente utilizada para la quimioterapia del CCR) mediante las vías de ERK MAPK y β-catenina.Este trabajo aporta información original respecto al rol del análogo tumoral de PTH en células tumorales intestinales y los mecanismos moleculares involucrados en la respuesta hormonal de estas células tanto in vitro como in vivo. Además, profundiza el conocimiento respecto de los mecanismos moleculares modulados por las hormonas calciotrópicas PTH y calcitriol en células tumorales intestinales. Un aporte de este Trabajo de Tesis es que al elucidar las vías de señalización que regulan los procesos inducidos por PTHrP y que favorecen la proliferación y/o quimiorresistencia, se podrían generar estrategias terapéuticas alternativas en el tratamiento del CCR cuya finalidad es inhibir la expresión de PTHrP o su mecanismo de acción en estas células tumorales.Parathyroid hormone (PTH) is an important mediator of bone remodeling and acts together with calcitriol (1α, 25 (OH)2vitamin D3), as an essential regulator of calcium and phosphorus homeostasis. The parathyroid hormone related peptide (PTHrP) is a poly hormone that has an important role in the development of the fetus and in the homeostasis of adult tissues acting mainly through paracrine pathways. It can be expressed and secreted by several tumors and is responsible for malignant humoral hypercalcemia, which is a sign of poor prognosis in malignant neoplasms. When this Thesis Work started, there was little information about the role of PTHrP acting as a paracrine factor on cells derived from colorectal cancer (CRC). In the present work it is demonstrated that PTHrP is able to induce an increase in the cellular proliferation of two cell lines derived from CRC, Caco-2 cells and HCT116 cells. In addition, this effect is modulated by PKC, Src, Akt, ERK MAPK and β-catenin. It was observed that in the intestinal tumor cells, the hormone triggers the increase of the expression and/or activation by phosphorylation of CREB/ATF-1, c-myc and cyclin D1, which are relevant molecules in the cell proliferation, through ERK MAPK. In agreement with the observed in vitro, the experiments developed in the murine model revealed that the continuous administration of the hormone in an intra-tumoral manner modulates the expression of ERK, cyclin D1 and CREB / ATF-1, which are key markers in the progression of CRC. Both, normal intestinal tumor cells and those that over-express PTHrP respond to the action of the calcitropic hormones PTH and calcitriol, at least at the transcriptional level, by decreasing the expression of PTHrP. PTHrP not only activates mitogenic pathways and induces the proliferation of Caco-2 and HCT116 cells, but it is also capable of decreasing the sensitivity of these cells to Irinotecan (which is a drug commonly used for CRC chemotherapy) through ERK MAPK and β-catenin pathways. This work provides original information about the role of the tumor analog of PTH in intestinal tumor cells and the molecular mechanisms involved in the hormonal response of these cells, both in vitro and in vivo. In addition, this work expands the knowledge regarding the molecular mechanisms modulated by the calcitropic hormones PTH and calcitriol in intestinal tumor cells. The contribution of this Thesis work is that by elucidating the signaling pathways that regulate the processes induced by PTHrP and that contribute to the proliferation and/or chemoresistance, alternative therapeutic strategies could be generated in the treatment of CRC whose purpose is to inhibit the expression of PTHrP or its mechanism of action in these tumor cells.Fil: Martín, María Julia

Tumor microenvironment involvement in colorectal cancer progression via Wnt/β-catenin pathway: Providing understanding of the complex mechanisms of chemoresistance

Colorectal cancer (CRC) continues to be one of the main causes of death from cancer because patients progress unfavorably due to resistance to current therapies. Dysregulation of the Wnt/β-catenin pathway plays a fundamental role in the genesis and progression of several types of cancer, including CRC. In many subtypes of CRC, hyperactivation of the β-catenin pathway is associated with mutations of the adenomatous polyposis coli gene. However, it can also be associated with other causes. In recent years, studies of the tumor microenvironment (TME) have demonstrated its importance in the development and progression of CRC. In this tumor nest, several cell types, structures, and biomolecules interact with neoplastic cells to pave the way for the spread of the disease. Cross-communications between tumor cells and the TME are then established primarily through paracrine factors, which trigger the activation of numerous signaling pathways. Crucial advances in the field of oncology have been made in the last decade. This Minireview aims to actualize what is known about the central role of the Wnt/β-catenin pathway in CRC chemoresistance and aggressiveness, focusing on cross-communication between CRC cells and the TME. Through this analysis, our main objective was to increase the understanding of this complex disease considering a more global context. Since many treatments for advanced CRC fail due to mechanisms involving chemoresistance, the data here exposed and analyzed are of great interest for the development of novel and effective therapies.Fil: Novoa Díaz, María Belén. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Martín, María Julia. Universidad Nacional del Sur. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Química del Sur. Universidad Nacional del Sur. Departamento de Química. Instituto de Química del Sur; ArgentinaFil: Gentili, Claudia Rosana. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentin

The pleiotropic transcriptional regulator NlpR contributes to the modulation of nitrogen metabolism, lipogenesis and triacylglycerol accumulation in oleaginous rhodococci

The regulatory mechanisms involved in lipogenesis and triacylglycerol (TAG) accumulation are largely unknown in oleaginous rhodococci. In this study a regulatory protein (here called NlpR: Nitrogen lipid Regulator), which contributes to the modulation of nitrogen metabolism, lipogenesis and triacylglycerol accumulation in oleaginous rhodococci was identified. Under nitrogen deprivation conditions, in which TAG accumulation is stimulated, the nlpR gene was significantly upregulated, whereas a significant decrease of its expression and TAG accumulation occurred when cerulenin was added. The nlpR disruption negatively affected the nitrate/nitrite reduction as well as lipid biosynthesis under nitrogen-limiting conditions. In contrast, its overexpression increased TAG production during cultivation of cells in nitrogen-rich media. A putative ‘NlpR-binding motif’ upstream of several genes related to nitrogen and lipid metabolisms was found. The nlpR disruption in RHA1 strain led to a reduced transcription of genes involved in nitrate/nitrite assimilation, as well as in fatty acid and TAG biosynthesis. Purified NlpR was able to bind to narK, nirD, fasI, plsC and atf3 promoter regions. It was suggested that NlpR acts as a pleiotropic transcriptional regulator by activating of nitrate/nitrite assimilation genes and others genes involved in fatty acid and TAG biosynthesis, in response to nitrogen deprivation.Fil: Hernández, Martín Alejandro. Universidad Nacional de la Patagonia "san Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; ArgentinaFil: Lara, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gago, Gabriela Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Gramajo, Hugo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia "san Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentin

Flora algal de la cuenca del río Guadalquivir: Su valor en la determinación de la ecorregionalización de la cuenca

In compliance with the Water Framework Directive of the European Union, we needed to diagnose the ecologic quality of the different sections of the rivers of the Guadalquivir basin. In order to establish a regional classification of the water bodies by a grouping into areas of similar characteristics, we took into consideration the benthic phycologic flora of the Guadalquivir-River basin. Benthic algae, being one of the groups of organisms that best define the water quality of rivers, are useful for characterizing the basin´s ecoregionalization. We collected multihabitat samples in 109 georeferenced reaches and identified 777 algal taxa: 397 Bacillariophyceae (diatoms), 181 Chlorophyta, 148 Cyanoprokariota, 41 Euglenophyta, 4 Chrysophyceae, 3 Dinophyta, 2 Rodophyta, and 1 Cryptophyta. Except for Achnanthidium minutissimum?it being present in nearly all the sites?the species composition enabled the identification of 4 groups: (1) the Sierra-Morena rivers with a predominantly siliceous substrate and concomitantly low mineralized water (< 250 mg/L); (2) the Doñana and lower-Guadiamar rivers of the lower-Guadalquivir with a high relative proportion of sodium; (3) rivers with any kind of disturbance, principally organic contamination, grouped regardless of their geographical location; (4) rivers of high calcium content that, though constituting a heterogeneous group, the majority of which belong to the Betic-Mountain region. According to our results, the subbasin was the one that determined the composition of the periphyton. The categorization of the rivers according to biota obtained in the present work differs from the hydrogeomorphological classification established by the Guadalquivir Hydrographic Confederation.En cumplimiento con la Directiva Marco para las Políticas del Agua (DMA) de la Unión Europea fue necesario diagnosticar la calidad ecológica de los distintos tramos de los ríos de la cuenca del Guadalquivir. Para establecer una regionalización de las masas de agua agrupándolas en zonas de similares características se tomó en consideración la flora ficológica bentónica de la cuenca del río Guadalquivir y su valor en la ecorregionalización de la cuenca debido a que las algas bentónicas están entre los grupos de organismos que mejor definen la calidad del agua de los ríos. Se extrajeron muestras multihábitat en 109 tramos georeferenciados. Se identificaron 777 taxa algales: 397 Bacillariophyceae (diatomeas), 181 Chlorophyta, 148 Cyanoprokariota, 41 Euglenophyta, 4 Chrysophyceae, 3 Dinophyta, 2 Rodophyta y 1 Cryptophyta. Con excepción de Achnanthidium minutissimun, que estuvo presente en casi todos los sitios, según la composición algal pueden identificarse 4 grandes grupos: 1) Sierra Morena, con sustrato predominantemente silíceo y concomitantemente aguas poco mineralizadas (< 250 mg/L); 2) ríos de la depresión del Bajo Guadalquivir, Doñana y bajo Guadiamar con una proporción relativamente elevada de sodio; 3) ríos con algún tipo de perturbación, principalmente contaminación orgánica, agrupados independientemente de su situación geográfica, 4) ríos con alto contenido de calcio en sus aguas que, si bien forman un grupo heterogéneo, la mayoría pertenecen a la región de las Montañas Béticas. De acuerdo con nuestros resultados, la subcuenca fue la que determinó la composición del perifiton. La categorización de los ríos según la biota obtenida en el presente trabajo difiere de la clasificación hidrogeomorfológica establecida por la Confederación Hidrográfica del Guadalquivir.Fil: Casco, Maria Adela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Ficología; ArgentinaFil: Reyes, Isabel. Universidad de Sevilla; EspañaFil: Martín, Gonzalo. Universidad de Sevilla; EspañaFil: Fernández, María R.. Universidad de Sevilla; EspañaFil: Sala, Silvia Estela. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Ficología; ArgentinaFil: Toja, Julia. Universidad de Sevilla; Españ

Stereoselective LC-MS/MS methodologies for environmental analysis of chiral pesticides

Chiral pesticides can exert stereospecific toxicity in contaminated environmental compartments. Therefore, measuring pesticides at the enantiomeric level is essential to assess the risk posed to exposed organisms, including humans. In recent years, there has been rapid progress on the development and application of stereoselective liquid chromatography–tandem mass spectrometry (LC–MS/MS) methodologies for monitoring pesticides in the environment. Coupling chiral LC separations with MS/MS detection enables trace enantiomeric determination of pesticides in complex environmental matrices. The intent of this review is to provide an up-to-date synopsis on recent advances of stereoselective LC–MS/MS methodologies for pesticide analysis. Key aspects of these methodologies discussed include sample storage and extraction method, stationary phases for separation, multi-residue separations, and method of quantitation. Finally, future trends in this rapidly growing field of analytical chemistry research are outlined

Anthocyanin Pigments: Importance, Sample Preparation and Extraction

Anthocyanins are naturally occuring pigments belonging to the group of flavonoids, a subclass of the polyphenol family. They are common components of the human diet, as they are present in many foods, fruits and vegetables, especially in berries and red wine. There were more studies conducted on effect of processing and storage on changes and stability of colors of anthocyanins in foods such as fruits and also for their use as natural colorants. Besides, the interest on anthocyanins is still growing also owing to their strong antioxidant activity against many chronic diseases, numerous studies about their medicinal, therapeutical and nutritional value were also conducted. There are pieces of evidence regarding the positive association of their intake with healthy biological effects. They act as antioxidants both in the foodstuffs in which they are found and in the organism that take in foods rich in anthocyanins. Many efforts have been carried out to develop new analytical techniques for identification and quantification of anthocyanins in plant materials, as well as their effects in vivo and in vitro. With this in mind, an overview to general considerations concerning (i) polyphenol and flavonoid history; (ii) chemical structure, color and intake of anthocyanins and (iii) sample preparation and extraction methods are presented in this chapter

El problema del cuerpo en el autismo: la solución de Grandin

El presente trabajo tiene como propósito presentar el problema del cuerpo en el funcionamiento autista e ilustrar el escollo que representa en esta forma de malestar subjetivo a partir de la singular solución de Temple Grandin, conocida mediante sus escritos autobiográficos. Realizaremos un análisis bibliográfico de autores del psicoanálisis que actualmente discuten sobre la cuestión del cuerpo en el autismo y de los testimonios autobiográficos publicados de Temple Grandin, una autista de alto funcionamiento mundialmente conocida por su labor en el campo de la zoología.We propose an analysis of texts by authors in the perspective of psychoanalysis, and the autobiographic testimonies of Temple Grandin. In the first place, we systematize the current developments in psychoanalysis in two positions. Those who argue that the autistic subject does not have a body, and those who argue that the body-shell they witness to arm themselves is a peculiar form of experiencing body. Second, we could say that the autobiography of Temple Grandin allows us to know how an autistic person faces certain problems, in which body is one of them.Mesas autoconvocadas: Cuerpo, época y presentaciones sintomáticas actuales: interrogantes y desafíos en psicopatología infanto-juvenilFacultad de Psicologí