RESUMEN Este artículo estudia el funcionamiento de internados de niños y niñas en el territorio de la Araucanía administrado por misioneros capuchinos, entre 1900 y 1935, periodo en el cual se ...consolidó la política reduccional del pueblo mapuche ejercida desde el Estado de Chile. El método fue cualitativo-descriptivo con un diseño historiográfico, el cual a partir de la triangulación metodológica permitió encontrar las siguientes categorías: choque cultural chilenización/evangelización/mundo mapuche en el internado, infancia mapuche encerrada según género, infancia mapuche reglamentada: formalización de rutinas, visitas controladas internados por parte de familias, justificación ideológica/presencia del internado; pérdida del mapuzungun y, agentes de la vigilancia y el control. Los resultados pueden contribuir a promover el interés por estudiar un campo inexplorado por la investigación educativa en América Latina: rol pedagógico de los internados en contextos de relaciones interétnicas.
ABSTRACT This article studies the operation of boarding schools for children in the territory of Araucanía, administered by Capuchin missionaries, between 1900 and 1935, during which the reduction policy of the Mapuche people was consolidated in Chile. The method was qualitative-descriptive with a historiographic design, from which, the following categories were found by a methodological triangulation: cultural shock Chileanization/evangelization/Mapuche world in the boarding school, Mapuche childhood separated according to gender, regulated Mapuche childhood: formalization of routines , controlled visits to the internees by their families, ideological justification/presence of the boarding school; Loss of the mapuzungun (Mapuche Language), agents of surveillance and control. The results can contribute to promote interest in studying an unexplored field of educational research in Latin America: the pedagogical role of internees in contexts of interethnic relations.
RESUMO Este artigo examina o funcionamento de internatos para crianças no território de Araucânia, Chile, administrados por missionários capuchinhos entre 1900 e 1935, período no qual se consolidou a política reducional do povo Mapuche exercida pelo Estado do Chile. A metodologia de pesquisa utilizada foi a qualitativa descritiva, com delineamento historiográfico, que a partir da triangulação metodológica permitiu encontrar as seguintes categorias: choque de culturas chinelização/evangelização/mundo Mapuche em internato; crianças Mapuche separadas por gênero; infância Mapuche regulamentada com a formalização de rotinas e visitas controladas aos internatos para as famílias; a justificação ideológica/presença do internato; perda do mapudungun, idioma Mapuche; e agentes de vigilância e controle. Os resultados podem ajudar a promover o interesse em estudar um campo inexplorado de pesquisa educacional na América Latina: o papel pedagógico das escolas em sistema de internato em contextos de relações interétnicas.
Abstract
Breast cancer is the second most common cancer worldwide after lung cancer. About 70% of breast cancers express estrogen receptor α (ER+) and/or progesterone receptor (PR+), and these ...biomarkers are indicative of hormone dependence. However up to 50% acquire resistance to hormone therapy 1, 2. Estrogen independent ER+ breast cancer depends on CDK4 for tumor growth and CDK4 inhibitors have emerged as a promising approach to treat this type of tumors 3. Abemaciclib is a cell cycle inhibitor with selective activity against CDK4 and CDK6 and it is being evaluated in advanced clinical trials for its potential to reduce metastatic ER+ breast cancer growth. We have evaluated combination of abemaciclib with an anti-estrogen therapy in an in vitro breast cancer panel. Phenotypic characterization of sensitive cell lines was carried out by monitoring cell proliferation, senescence, and apoptosis markers using flow cytometry and high content imaging approaches. Using an in vitro panel with a diversity of breast cancer cell lines, a synergistic effect of abemaciclib in combination with the ER down-regulating drug fulvestrant was observed based on Bliss score. This combination treatment demonstrated effective growth inhibition in ER+ cells and exhibited synergism in MCF-7, T47D and ZR-75-1. The mechanistic analyses revealed that the combination of abemaciclib with fulvestrant promoted a decrease in cancer cell proliferation due to G1 phase arrest at doses tested. This growth inhibition was accompanied by increased hallmarks for cell senescence as observed by markers such as SA-β-galactosidase staining or morphological changes. Subsequently, an increase in biomarkers for apoptosis was also observed. These changes occurred in a time dependent manner and were significantly greater with the combination than fulvestrant single agent treatment. We conclude the combination of abemaciclib with fulvestrant better prevented proliferation of breast cancer cell lines by blocking cell proliferation and lead to induction of senescence and apoptosis as compared to fulvestrant treatment alone in ER+ cells.
Bibliography
1 American Cancer Society, Cancer Facts & Figures 2014.
2 Dixon J.M. (2014) New Journal of Science. Volume 2014, Article ID 390618.
3 Miller TW et al. (2011) Cancer Discov. Volume 1 (4): 338-51.
Citation Format: Raquel Torres, Bruna Calsina, Ana Hermoso, Carmen Baquero, Cecilia Mur, Karsten Boehnke, Joaquín Amat, Alfonso De Dios, Xueqian Gong, Sean Buchanan, Richard Paul Beckmann, Maria Jose Lallena. Characterization of the mechanism of action for abemaciclib with antiestrogen combined therapy in human breast cancer cell lines. abstract. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2836.
Abstract
Targeting cyclin dependent kinases 4 and 6 (CDK4/6) with inhibitors such as abemaciclib has shown promise in early and late phase clinical trials in both breast cancer and NSCLC. While there ...is evidence that patients benefit from single-agent abemaciclib, combination strategies leveraging this compound together with immunotherapy are of interest for the treatment of these and other cancers. Consequently, it is important to understand if and how a cell cycle inhibitor can be combined with immunotherapy. However, because most preclinical studies have been performed using xenograft tumors in immune-compromised mice, the potential immunomodulatory effects of abemaciclib have not been adequately ascertained. To investigate the immune combinatorial potential of abemaciclib, we studied the effects of treatment alone and in combination with checkpoint immunotherapy in a murine syngeneic tumor model sensitive to abemaciclib using immuno-competent mice. Abemaciclib monotherapy of established murine CT26 tumors, which harbor KRAS G12C mutation and CDKN2A deletion, caused a dose-dependent delay in tumor growth. Surprisingly, gene expression analysis showed that treatment was associated with an increase in intra-tumor immune inflammation without major alteration in immune subset frequencies. Testing of various dosing regimens in this preclinical model found that monotherapy abemaciclib pretreatment followed by combination with anti-PD-L1 antibody therapy, induced an enhanced anti-tumor response compared to abemaciclib and anti-PD-L1 monotherapies. Optimal combination therapy exhibited superior anti-tumor efficacy, resulting in complete tumor regression (CR) in 50-60% of mice in a setting where anti-PD-L1 monotherapy showed little or no efficacy (0% CRs). Mice which maintained CRs after cessation of combination therapy were able to resist later CT26 rechallenge, demonstrating that abemaciclib in combination with anti-PD-L1 enabled the generation of an immunologic memory. Examination of intra-tumor gene expression during treatment found that combination therapy further amplified the immune/T cell activation signature compared to both monotherapies. Intra-tumoral suppression of cell cycle genes, which are indicative of inhibition of CDK4/6, was also greater during the combination therapy, suggesting that the effects anti-PD-L1 therapy may augment the cell cycle arrest induced by abemaciclib. Although it was uncertain if agents that inhibit cell proliferation could be combined with immunotherapy, these preclinical results demonstrate that it is possible to combine CDK4/6 inhibition by abemaciclib with checkpoint immunotherapy to improve tumor efficacy. The synergistic responses observed in terms of tumor efficacy, immune activation, and cell cycle control provides support for the clinical investigation of this combination.
Citation Format: Jack Dempsey, Lysiane Huber, Amelie Forest, Jennifer R. Stephens, Thompson N. Doman, Jason Manro, Andrew Capen, Robert S. Flack, Gregory P. Donoho, Sean Buchanan, Alfonso De Dios, Kyla Driscoll, Michael Kalos, Ruslan Novosiadly, Richard P. Beckmann, David A. Schaer. The CDK4/6 inhibitor abemaciclib induces synergistic immune activation and antitumor efficacy in combination with PD-L1 blockade abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 583. doi:10.1158/1538-7445.AM2017-583
Abstract
The approval of abemaciclib and additional cyclin dependent kinases 4 & 6 (CDK4/6) inhibitors for the treatment of HR+ breast cancer has provided new therapeutic options to patients. As ...CDK4/6 inhibitors become part of the standard of care, combination strategies leveraging abemaciclib together with immunotherapy may represent an opportunity to extend benefit to more patients and additional cancers. Accordingly, it is important to understand if and how a cell cycle inhibitor can be combined with immunotherapy. To investigate the immune combinatorial potential of abemaciclib, we studied the effects of treatment alone and in combination with PD-L1 blockade in immunocompetent murine syngeneic tumor models, and directly evaluated the tumor cell and immune cell intrinsic immunologic effect of abemaciclib in vitro. In vivo abemaciclib treatment of murine tumors (CT26, EMT6 and MC38) caused a dose-dependent delay in tumor growth and demonstrated the potential to induce complete tumor regression (CR ~10%). Combination with an anti-PD-L1 antibody after abemaciclib pretreatment greatly enhanced the anti-tumor response compared to abemaciclib and anti-PD-L1 monotherapies. Optimal combination therapy resulted in 50-60% CRs of mice in a setting where anti-PD-L1 monotherapy showed little or no efficacy (0% CRs). Mice maintaining CRs after cessation of combination therapy or abemaciclib monotherapy resisted later CT26 rechallenge, demonstrating the ability to generate immunological memory during abemaciclib therapy. Analysis of intra-tumor gene expression showed that abemaciclib monotherapy induced T cell activation and inflammation signatures. Combination therapy substantially enhanced this effect and was additionally associated with DC maturation, antigen presentation, cytokine signaling and helper T cell phenotype. Suppression of cell cycle genes indicative of inhibition of CDK4/6 was also more prominent during the combination therapy. In Jurkat and primary human T cells, treatment with abemaciclib in vitro resulted in a dose-dependent increase in NFAT activity upon TCR stimulation. This correlated with upregulation of both cell surface markers and genes associated with an enhanced T cell activation phenotype, while only modestly affecting T cell expansion. Abemaciclib also amplified expression of antigen presentation and other immune-related genes in human breast cancer cells. Although it was uncertain if agents that inhibit cell proliferation could be combined with immunotherapy, these preclinical results provide a strong rationale for combining abemaciclib with checkpoint immunotherapy to improve the anti-tumor efficacy. The T cell and tumor cell intrinsic effects, synergistic anti-tumor responses and intra-tumor immune activation, justify clinical investigation of this combination.
Citation Format: David Schaer, Richard Beckmann, Jack Dempsey, Lysiane Huber, Amelie Forest, Nelusha Amaladas, Ying Cindy Wang, Erik Rasmussen, Darin Chin, Yanxia Li, Andrew Capen, Marianne Deroose, Carmine Carpenito, Xueqian Gong, Kirk Staschke, Linda Chung, Farhana Merzoug, Trent Stewart, Lacey Litchfield, Philip Iversen, Sean Buchanan, Alfonso de Dios, Ruslan Novosiadly, Michael Kalos. The CDK4/6 inhibitor abemaciclib synergizes with PD-L1 blockade to induce an immune inflamed tumor microenvironment through T cell and tumor cell intrinsic effects abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4569.
Abstract
Dysregulation of the cell-cycle is a hallmark of cancer and genetic alterations in its regulatory machinery (or checkpoints) occur in most human tumors. The majority these defects are found ...in genes encoding for proteins regulating G1 phase progression, such as Rb, E2F1, CyclinD1, CDK4 and CDK6. Aberrant regulation of the G1 kinases CDK4 and CDK6, as well as overexpression or gene amplification of CyclinD, lead to inhibition of tumor suppressors such as Rb resulting in an accelerated cell cycle progression. Alterations in the CyclinD-CDK4/6-Rb pathway are common in breast cancer. Amplification of CCND1 gene encoding CyclinD1, occurs in 15% to 20% of breast cancers, and CyclinD1 overexpression is even more common (up to 50% of breast cancers).
Abemaciclib is a reversible, ATP competitive, kinase inhibitor selective for CDK4 and CDK6 that has been shown to prevent growth of malignant cells in-vitro and in-vivo. This antitumor activity is mediated by inhibiting the phosphorylation of Rb and subsequent blockade of tumor cell cycle progression through G1/S.
CDK4/6 inhibitors in general have shown significant potential for the treatment of metastatic breast cancer and Abemaciclib, in particular, is currently being evaluated in advanced clinical trials (Phase II as single agent and Phase III in combination with anti-hormone therapy) in hormone receptor positive metastatic breast cancer patients.
The goal of this study was to investigate the mechanism of action of Abemaciclib in ER+ luminal breast cancer. We have evaluated the response of the drug in a diversity of breast cancer cell lines. Phenotypic characterization of sensitive cell lines was carried out by monitoring proliferation, cell cycle progression and phosphorylation of Rb using High Content Imaging. Senescence markers were included in the study to monitor the final outcome of the cells upon sustained exposure to the drug.
Luminal ER+ breast cancer cells showed a marked sensitivity to treatment with Abemaciclib with IC50 values ranging from 5nM to 2uM.
Simultaneous decrease in Rb phosphorylation with sustained accumulation of the 2N subpopulation was observed. Associated to the G1S arrest phenotype, Abemaciclib treatment resulted in a decrease of cell proliferation markers (Ki67 and BrdU). Additionally, a marked hyper-methylation profile (Histone H3K9met3) and a decrease of FOXM1 expression were observed, as well as an accumulation of endogenous beta-galactosidase and p21. Taken together this profile suggests that Abemaciclib acts through promotion of senescence in breast cancer cells.
Abemaciclib prevents proliferation of breast cancer cell lines expressing D-types cyclins by promoting cell cycle arrest mediated by inhibition of Rb phosphorylation. Abemaciclib is a CDK4/6 inhibitor with potential to treat breast cancer by blocking cell proliferation leading to induction of senescence.
Citation Format: Maria Jose Lallena, Karsten Boehnke, Raquel Torres, Ana Hermoso, Joaquin Amat, Bruna Calsina, Alfonso De Dios, Sean Buchanan, Jian Du, Richard Paul Beckmann, Xueqian Gong, Ann Mcnulty. In-vitro characterization of Abemaciclib pharmacology in ER+ breast cancer cell lines. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3101. doi:10.1158/1538-7445.AM2015-3101
Abstract
It is well established that phosphorylation of Rb-family pocket proteins by CDK4 and CDK6 is important for the commitment of cancer cells to a new cell cycle and the initiation of the G1-S ...phase transition. Abemaciclib is a potent inhibitor of the kinase activity of both CDK4 and CDK6 and is currently undergoing clinical testing. To better understand the molecular determinants of response to abemaciclib, we tested its anti-proliferative activity across a panel of over 500 well characterized cancer cell lines. Statistical approaches were employed to uncover genomic features associated with the response. Candidate markers of sensitivity and resistance were further tested by genetic manipulations in vitro. In vivo models representing the candidate molecular marker of sensitivity were identified and drug efficacy examined.
Three broad classes of response were identified. The class of tumors cells most resistant to abemaciclib showed enrichment for RB1 mutations. Conversely, cell lines with amplification of CCND2 and CCND3 were among the very most sensitive tumor cells and tumor cells with these markers showed evidence of senescence and apoptosis after either depletion of the cognate D-cyclin or treatment with abemaciclib. In vivo models of tumors harboring CCND2 and CCND3 gene amplification were very sensitive to abemaciclib treatment and showed evidence of tumor regression.
Citation Format: Xueqian Gong, Li-Chun Chio, MaryJo Lallena, Farhana Merzoug, Shaoyou Chu, Yue Webster, Jack Dempsey, Xiwen Ma, Alfonso De Dios, Richard Beckman, Sean G. Buchanan. Molecular features that determine the sensitivity of cancer cells to abemaciclib, an inhibitor of CDK4 and CDK6. abstract. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3104. doi:10.1158/1538-7445.AM2015-3104
Abstract
Proper patient-tailoring strategy and the validation of novel therapeutic targets remain enormous challenges during drug discovery processes. Patient-derived three-dimensional organoid cell ...culture models possess great potential to associate compound sensitivity and disease complexity in order to provide a key missing link between compound screening and clinical trials. Abemaciclib is a reversible, ATP competitive, selective inhibitor of the kinase activity of both CDK4 and CDK6 and is currently undergoing advanced clinical testing.
In this study, we established and characterized three-dimensional organoid cultures from primary colorectal cancer patients and validated their use as drug sensitivity models. We aimed to explore the antitumor activity of abemaciclib in colon cancer organoid cultures by assessing markers for cell viability, proliferation, cell cycle, senescence and apoptosis. Single cell suspension of patient-derived samples were precultured for four days to allow for complete morphogenesis of three-dimensional organoid structures. Subsequently, the cultures were treated for at least two population doubling times and analyzed by luminescent cell viability, immunohistochemistry and flow cytometry assays.
Our data suggest that abemaciclib treatment decreased the cell viability of patient-derived colorectal cancer organoid cultures characterized by G1 cell cycle arrest and reduced Ki-67-positive cells. Furthermore, treated cultures showed elevated levels of reactive oxygen species and increased markers for early and late apoptosis. In summary, complex organoid models have the potential to further evaluate the antitumor activity of abemaciclib in various tumor types by enabling mechanistic studies in a patient-specific preclinical setting.
Citation Format: Karsten Boehnke, Bruna Calsina, Joaquín Amat, Ana Hermoso, Raquel Torres, Christoph Reinhard, Juan A. Velasco, Philip W. Iversen, Alfonso De Dios, Sean Buchanan, Richard P. Beckmann, Dirk Schumacher, Christian RA Regenbrecht, Marie-Laure Yaspo, Hans Lehrach, María José Lallena. Preclinical analysis and characterization of abemaciclib using three-dimensional patient-derived colorectal cancer organoid cultures. abstract. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2829.
Some imidazolidine-2,4-dione (hydantoin) and thiazolidine-2,4-dione (TZD) derivatives with a 1H-pyrrol-2-ylmethylene substituent at the 5-position (
1
8
) have been synthesized via an aldol ...condensation reaction. A mixture of Z- and E- stereoisomers was obtained, as confirmed by HPLC and NMR studies. Assignment of the stereochemistry was achieved through chemical shift knowledge, NOE, and
3
J
H,C
data. The conformation of the molecules depends on the configuration at the double bond. While the (NH,C cis) form is the most stable conformer for the E-isomer, the (NH,C trans) form is the preferred conformer for the Z-isomer. The temperature coefficients of the NH pyrrole protons reveal the existence of an intramolecular hydrogen bond for the E-isomers.Key words: hydantoin, TZD, NMR spectroscopy, conformational analysis, temperature coefficient.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The p38 MAP kinase activity of two series of trisubstituted imidazoles (X
=
C, N) is reported, leading to compounds with highly potent cellular and in vivo activity.
Herein we report investigations ...into the p38α MAP kinase activity of trisubstituted imidazoles that led to the identification of compounds possessing highly potent in vivo activity. The SAR of a novel series of imidazopyridines is demonstrated as well, resulting in compounds possessing cellular potency and enhanced in vivo activity in the rat collagen-induced arthritis model of chronic inflammation.
Abstract
We developed a combination screening protocol to look for synergistic interactions with abemaciclib, an inhibitor of cyclin dependent kinases 4 and 6 (CDK4 and CDK6). Abemaciclib ...(LY2835219), has shown cytostatic effects in some cell lines while inducing senescence and apoptosis in particularly sensitive cell lines. Abemaciclib, combined with various compounds, was screened across panels of genomically characterized tumor cells. These screens identified several synergistic interactions that improved the activity of abemaciclib in cancer cells lines that respond to abemaciclib monotherapy (e.g. mantle cell lymphoma, ER+ breast cancer) but additionally revealed certain combinations with synergy in Rb wild-type cancers that do not respond optimally to single agent abemaciclib treatment. Most interestingly, MEK inhibitors and LY3009120, a novel Raf dimer inhibitor that inhibits all three Raf isoforms (Cancer Cell 28:384-98) were found to potentiate the cytostatic effects of abemaciclib in these cell lines leading to apoptosis in vitro and tumor regression in vivo. Further analysis of the effects of combined inhibition of CDK4 and CDK6 and Raf isoforms on downstream signaling pathways provides mechanistic clues that may help explain the observed synergy.
Citation Format: Gong Xueqian, Li-Chun Chio, Yue Webster, Maria Jose Lallena, Karsten Boehnke, Raquel Torres, Phil Iversen, Alfonso De Dios, Ian Smith, Christoph Reinhard, Sheng-Bin Peng, Jack Dempsey, Teresa Burke, Shih-Hsun Chen, Trent Stewart, Richard Beckmann, Wenjuan Wu, Sean G. Buchanan. The identification of combinations for the CDK4 and CDK6 inhibitor, abemaciclib. abstract. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A07.
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