Person:
Cáceres Ramos, Sara Cristina

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First Name
Sara Cristina
Last Name
Cáceres Ramos
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Fisiología
Area
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UCM identifierScopus Author IDDialnet ID

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Now showing 1 - 5 of 5
  • Publication
    Blocking Estrogen Synthesis Leads to Different Hormonal Responses in Canine and Human Triple Negative Inflammatory Breast Cancer
    (MDPI, 2021-10-02) Cáceres Ramos, Sara Cristina; Beatriz Monsalve; Angela Alonso-Diez; Belén Crespo; Illera Del Portal, Josefina María; Andrés Gamazo, Paloma Jimena De; Silván Granado, Gema; Illera Del Portal, Juan Carlos
    Blocking estrogen synthesis by inhibitors of estrogen synthesis is a widely used therapy against estrogen receptor-positive tumors. However, these therapies are less effective in negative expression tumors. Therefore, this study determined the effectiveness of anti-aromatase and anti-sulfatase therapies in canine and human inflammatory breast cancer. Cell cultures and xenografts from IPC-366 and SUM149 were treated with different doses of letrozole (anti-aromatase) and STX-64 (anti-sulfatase), in order to observe their effectiveness in terms of cell proliferation, tumor progression, and the appearance of metastases and hormonal profiles. The results revealed that both treatments are effective in vitro since they reduce cell proliferation and decrease the secreted estrogen levels. In xenograft mice, while treatment with letrozole reduces tumor progression by 30-40%, STX-64 increases tumor progression by 20%. The hormonal results obtained determined that STX-64 produced an increase in circulating and intratumoral levels of estradiol, which led to an increase in tumor progression. However, letrozole was able to block estrogen synthesis by decreasing the levels of circulating and intratumoral estrogen and thus slowing down tumor progression. In conclusion, letrozole can be an effective treatment for canine and human inflammatory breast cancer. The knowledge of the hormonal profile of breast tumors reflects useful information on the effectiveness of different endocrine treatments.
  • Publication
    Tumor Growth Progression in Ectopic and Orthotopic Xenografts from Inflammatory Breast Cancer Cell Lines
    (MDPI, 2021-09-13) Cáceres Ramos, Sara Cristina; Alonso-Diez, Angela; Crespo, Belén; Peña Fernández, Laura Luisa; Illera Del Portal, Josefina María; Silván Granado, Gema; Andrés Gamazo, Paloma Jimena De; Illera Del Portal, Juan Carlos
    Xenografts can grow in immunosuppressed hosts, such as SCID mice, and tumor material can be injected into hosts either ectopically or orthotopically. Choosing the correct model to use is a crucial step in animal research. The aim of this study was to report the differences between ectopic and orthotopic xenografts in tumor progression, metastasis capacity, histological features, and steroid hormone profiles in xenografts from the cIMC (canine inflammatory mammary cancer) cell line IPC-366 and hIBC (human inflammatory breast cancer) cell line SUM149. To achieve this purpose, 40 female mice 6–8 weeks old were inoculated with IPC-366 and SUM149 cells subcutaneously (ectopic models) or into mammary fat pad (orthotopic models). Mice were monitored for tumor progression and appearance of metastases, and generated tumors were analyzed in terms of histological examination and steroid hormone production. The results revealed differences in tumor appearance and percentage of metastasis between ectopic and orthotopic models, which were higher in the ectopic xenografts from both cell lines. However, both models had similar characteristics of tumor progression, histological features, and steroid hormone secretion profiles. We show that the ectopic model can be validated as a good and useful model of tumor development in addition to, not contrary to, the orthotopic model in breast cancer research.
  • Publication
    Non-Invasive Determination of Annual Fecal Cortisol, Androstenedione, and Testosterone Variations in a Herd of  Male Asian Elephants (Elephas maximus) and Their Relation to Some Climatic Variables
    (MDPI, 2021-09-17) Andrés Gamazo, Paloma Jimena De; Cáceres Ramos, Sara Cristina; Belén Crespo; Silván Granado, Gema; Illera Del Portal, Juan Carlos
    The measurement of stress and reproductive hormones in wild animal species by non-invasive methods is of special interest. To assess whether the adrenal and gonadal hormones show annual variations in male Asian elephants (Elephas maximus) and to evaluate whether there is any influence of climatic variables on hormonal secretion, fecal samples were taken from a herd of 7 Asian elephants over a 14-month period to subsequently determine the concentrations of testosterone (T), androstenedione (A4), and cortisol (C) by a validated immunoassay technique. Data referring to three climatic variables in the place and period of study were collected, namely monthly mean values of temperature, humidity and rainfall. Levels of T and A4 showed two major increases in July (T: 1088.35 ± 131.04 ng/g; A4: 480.40 ± 50.86 ng/g) and October (T: 825.09 ± 31.60 ng/g; A4: 319.96 ± 32.69 ng/g) (p < 0.05). Our results show a secretion of fecal androgens dependent on temperature (T and A4), and humidity (T). Male musth was detected during the initial increases of T and A4 levels. The highest concentrations of C were observed in September (156.67 ± 60.89 ng/g) (p < 0.05), probably due to the stressful fights that occurred during the musth period. The observed results of the fecal levels of T, A4 and C were similar to those obtained by invasive methods. In conclusion, fecal secretion of the three hormones in these captive male Asian elephants showed variations related in some cases to different weather factors.
  • Publication
    Anti-Angiogenic Treatments Interact with Steroid Secretion in Inflammatory Breast Cancer Triple Negative Cell Lines
    (MDPI, 2021-07-21) Alonso Diez, Angela; Cáceres Ramos, Sara Cristina; Peña Fernández, Laura Luisa; Crespo, Belen; Illera Del Portal, Juan Carlos
    Human inflammatory breast cancer (IBC) is a highly angiogenic disease for which an-tiangiogenic therapy has demonstrated only a modest response, and the reason for this remains unknown. Thus, the purpose of this study was to determine the influence of different antiangiogenic therapies on in vitro and in vivo steroid hormone and angiogenic growth factor production using canine and human inflammatory breast carcinoma cell lines as well as the possible involvement of sex steroid hormones in angiogenesis. IPC-366 and SUM149 cell lines and xenotransplanted mice were treated with different concentrations of VEGF, SU5416, bevacizumab and celecoxib. Steroid hormone (progesterone, dehydroepiandrostenedione, androstenedione, testosterone, dihydrotestos-terone, estrone sulphate and 17β-oestradiol), angiogenic growth factors (VEGF-A, VEGF-C and VEGF-D) and IL-8 determinations in culture media, tumour homogenate and serum samples were assayed by EIA. In vitro, progesterone-and 17β-oestradiol-induced VEGF production promoting cell proliferation and androgens are involved in the formation of vascular-like structures. In vivo, intratumoural testosterone concentrations were augmented and possibly associated with decreased metastatic rates, whereas elevated E1SO4 concentrations could promote tumour progression after antiangiogenic therapies. In conclusion, sex steroid hormones could regulate the production of angiogenic factors. The intratumoural measurement of sex steroids and growth factors may be useful to develop preventive and individualized therapeutic strategies.
  • Publication
    Prácticas virtuales de fisiología
    (2022) García García, Rosa María; Lorenzo González, Pedro Luis; Revuelta Rueda, Luis; Costa Buitrago, Gonzalo Antonio; Triguero Robles, Domingo; García Pascual, Mª de los Ángeles; Picazo González, Rosa Ana; González Gil, Alfredo; Arias Álvarez, María; Silván Granado, Gema; Illera Del Portal, Josefina María; Illera Del Portal, Juan Carlos; Cáceres Ramos, Sara Cristina; Fernández-Pacheco Martorell, Carlota Almudena; Quiroga del Río, Carmen Alejandra; Cascón Hernández, Ignacio; Liceras de Bernardo, Oiane; Sánchez Arévalo, Patricia; Albertos Encinas, Carla; Camargo Plaza, Lucía Candela; Jerónimo Sánchez, Benedicto; García Velasco, Carmen; Moya Ortega, Jesús Modesto; Millán Pastor, María Pilar
    El presente proyecto de innovación educativa ha servido para generar material audiovisual compatible con dispositivos electrónicos para el aprendizaje de fisiología de una manera sencilla y accesible. Es la continuación de un proyecto del curso 2020-21, en el que se generó un material con las prácticas que se realizan con un programa de registros fisiológicos. En esta ocasión, se procedió a la grabación de los procedimientos experimentales de las asignaturas de Fisiología del Grado en Veterinaria y del Grado en CyTA y se han incluido en un formato presentación, en el que se exponen los conocimientos básicos de la práctica, los objetivos, el material y métodos, el procedimiento experimental en vídeo con explicaciones y finalmente la recogida de datos y la interpretación de los resultados. Así, se reduce el número de animales a utilizar en las prácticas porque no es necesario volver a hacer el procedimiento en el animal y el estudiante puede aprender a su ritmo y visualizar la presentación tantas veces como necesite para su aprendizaje, antes, durante y después de la práctica. Se ha contado con un amplio equipo en el que han participado PDI del departamento de Fisiología y de Producción Animal, PAS y estudiantes de grado y posgrado, de modo que la experiencia de todos ellos ha aportado un enfoque multidisciplinar, muy adecuado para la viabilidad del proyecto. El producto generado es un material duradero en el tiempo, que seguirá poniéndose a disposición de los estudiantes en cursos venideros.