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BACKGROUND: Advance care planning in dementia includes supporting the person and their family to consider important goals of care. International research reports the importance of psycho-social-spiritual aspects towards end of life. AIM: To develop a multidimensional international palliative care goals model in dementia for use in practice. DESIGN: International Delphi study integrating consensus and evidence from a meta-qualitative study. The Delphi panel rated statements about the model on a 5-point agreement scale. The criteria for consensus were pre-specified. SETTING/PARTICIPANTS: Seventeen researchers from eight countries developed an initial model, and 169 candidate panellists were invited to the international online Delphi study. RESULTS: Panellists (107; response 63.3%) resided in 33 countries. The model comprised four main care goals: (1) Comfort ensured; (2) Control over function maintained; (3) Identity protected and personhood respected and (4) Coping with grief and loss-person and caregiver supported. The model reflects how needs and care goals change over time with the progression of dementia, concluding with bereavement support. The first version of the model achieved a consensus after which it was slightly refined based on feedback. We did not achieve a consensus on adding a goal of life prolongation, and on use of the model by people with dementia and family themselves. CONCLUSION: A new palliative care goals model for people with dementia and their families includes relationship aspects for use by professionals and achieved a consensus among a panel with diverse cultural background. The position of life prolongation in relation to palliative care goals needs further research.
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Planificación Anticipada de Atención , Demencia , Humanos , Cuidados Paliativos , Consenso , Objetivos , Técnica DelphiRESUMEN
The pathological conditions of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) are the major risk factors for hepatocellular carcinoma (HCC). Exposure to DNA-damaging agents such as ionizing radiation is another risk factor for HCC; calorie restriction (CR), however, effectively delays the onset of radiation-induced HCC. We investigated whether NASH is relevant to radiation-induced HCC and the cancer-preventing effect of CR. Eight-day-old male B6C3F1 mice were irradiated with 3.8 Gy of X-rays and then fed a standard diet or 30% CR diet from 49 days of age until necropsy, which was performed from 56 to 600 days with ~100-day intervals to assess both pathological changes and gene expression levels. We found that early-life exposure to radiation accelerated lipid accumulation and NASH-like histopathological changes in the liver, accompanied by accelerated development of HCC. CR ameliorated the changes in lipid metabolism in the liver and reversed the NASH-like pathology, which effectively delayed HCC development. Gene-expression profiling revealed the radiation-related activation and CR-related suppression of the peroxisome proliferator-activated receptor gamma/Cd36 pathway of transmembrane fatty-acid translocation before development of the NASH-like state. Thus, early-life exposure to radiation affects lipid metabolism and induces a steatoinflammatory microenvironment that favors HCC development. Therefore, targeting this pathway by CR (or measures that mimic CR) may be a promising strategy for preventing HCC caused by either radiation or other DNA-damaging agents.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Masculino , Animales , Ratones , Carcinoma Hepatocelular/patología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Neoplasias Hepáticas/genética , Restricción Calórica , Hígado/patología , Radiación Ionizante , Microambiente TumoralRESUMEN
Ceramide is a bioactive sphingolipid that mediates ionizing radiation- and chemotherapy-induced apoptosis. Neocarzinostatin (NCS) is a genotoxic anti-cancer drug that induces apoptosis in response to DNA double-strand breaks (DSBs) through ataxia telangiectasia mutated (ATM) activation. However, the involvement of ceramide in NCS-evoked nuclear events such as DSB-activated ATM has not been clarified. Here, we found that nuclear ceramide increased by NCS-mediated apoptosis through the enhanced assembly of ATM and the meiotic recombination 11/double-strand break repair/Nijmengen breakage syndrome 1 (MRN) complex proteins in human lymphoblastoid L-39 cells. NCS induced an increase of ceramide production through activation of neutral sphingomyelinase (nSMase) and suppression of sphingomyelin synthase (SMS) upstream of DSB-mediated ATM activation. In ATM-deficient lymphoblastoid AT-59 cells compared with L-39 cells, NCS treatment showed a decrease of apoptosis even though ceramide increase and DSBs were observed. Expression of wild-type ATM, but not the kinase-dead mutant ATM, in AT-59 cells increased NCS-induced apoptosis despite similar ceramide accumulation. Interestingly, NCS increased ceramide content in the nucleus through nSMase activation and SMS suppression and promoted colocalization of ceramide with phosphorylated ATM and foci of MRN complex. Inhibition of ceramide generation by the overexpression of SMS suppressed NCS-induced apoptosis through the inhibition of ATM activation and assembly of the MRN complex. In addition, inhibition of ceramide increased by the nSMase inhibitor GW4869 prevented NCS-mediated activation of the ATM. Therefore, our findings suggest the involvement of the nuclear ceramide with ATM activation in NCS-mediated apoptosis. SIGNIFICANCE STATEMENT: This study demonstrates that regulation of ceramide with neutral sphingomyelinase and sphingomyelin synthase in the nucleus in double-strand break-mimetic agent neocarzinostatin (NCS)-induced apoptosis. This study also showed that ceramide increase in the nucleus plays a role in NCS-induced apoptosis through activation of the ataxia telangiectasia mutated/meiotic recombination 11/double-strand break repair/Nijmengen breakage syndrome 1 complex in human lymphoblastoid cells.
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Ataxia Telangiectasia , Cinostatina , Apoptosis/genética , Ataxia Telangiectasia/genética , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ceramidas/farmacología , Reparación del ADN , Proteínas de Unión al ADN/metabolismo , Humanos , Proteínas Serina-Treonina Quinasas , Esfingomielina Fosfodiesterasa/genética , Esfingomielina Fosfodiesterasa/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Cinostatina/farmacologíaRESUMEN
Women who are heterozygous for deleterious BRCA1 germline mutations harbor a high risk of hereditary breast cancer. Previous Brca1-heterozygous animal models do not recapitulate the breast cancer phenotype, and thus all currently used knockout models adopt conditional, mammary-specific homozygous Brca1 loss or addition of Trp53 deficiency. Herein, we report the creation and characterization of a novel Brca1 mutant rat model harboring the germline L63X mutation, which mimics a founder mutation in Japan, through CRISPR-Cas9-based genome editing. Homozygotes (Brca1L63X/L63X ) were embryonic lethal, whereas heterozygotes (Brca1L63X/+ ) showed apparently normal development. Without carcinogen exposure, heterozygotes developed mammary carcinoma at a comparable incidence rate with their wild-type (WT) littermates during their lifetime. Intraperitoneal injection of 1-methyl-1-nitrosourea (25 or 50 mg/kg) at 7 weeks of age induced mammary carcinogenesis at comparable levels among the heterozygotes and their littermates. After exposure to ionizing radiation (0.1-2 Gy) at 7 weeks of age, the heterozygotes, but not WT littermates, displayed dose-dependent mammary carcinogenesis with 0.8 Gy-1 excess in hazard ratio during their middle age; the relative susceptibility of the heterozygotes was more prominent when rats were irradiated at 3 weeks of age. The heterozygotes had tumors with a lower estrogen receptor α immunopositivity and no evidence of somatic mutations of the WT allele. The Brca1L63X/+ rats thus offer the first single-mutation, heterozygous model of BRCA1-associated breast cancer, especially with exposure to a DNA break-inducing carcinogen. This implies that such carcinogens are causative and a key to breast cancer prevention in individuals who carry high-risk BRCA1 mutations.
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Neoplasias de la Mama , Neoplasias Inducidas por Radiación , Animales , Proteína BRCA1/genética , Neoplasias de la Mama/genética , Carcinógenos , Transformación Celular Neoplásica , Receptor alfa de Estrógeno/genética , Femenino , Mutación de Línea Germinal , Humanos , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/genética , RatasRESUMEN
BACKGROUND: Research on the nature of a "good death" has mostly focused on dying with cancer and other life-limiting diseases, but less so on dementia. Conceptualizing common cross-cultural themes regarding a good end of life in dementia will enable developing international care models. METHODS: We combined published qualitative studies about end of life with dementia, focus group and individual interviews with the researchers, and video-conferencing and continuous email discussions. The interviews were audio-recorded and transcribed verbatim. The data were analyzed thematically, and the researchers developed common themes referring to their original studies. RESULTS: Fourteen qualitative researchers representing 14 cross-cultural studies covering qualitative data of 121 people with dementia and 292 family caregivers. The researchers and data were from eight countries UK, The Netherlands, Japan, Portugal, Germany, Canada, Brazil, and Ireland. Three focus groups, five individual interviews, and video-conferencing were conducted and feedback on multiple iterations was gained by 190 emails between May 2019 and April 2020 until consensus was achieved. Nine cross-culturally common themes emerged from the discussions and shared interpretation of the data of persons with dementia and family caregivers. Three represent basic needs: "Pain and Symptoms Controlled," "Being Provided Basic Care," and "A Place like Home." Other themes were "Having Preferences Met," "Receiving Respect as a Person," "Care for Caregivers," "Identity Being Preserved," "Being Connected," and "Satisfaction with Life and Spiritual Well-being." "Care for Caregivers" showed the greatest difference in emphasis across cultures. Good relationships were essential in all themes. CONCLUSIONS: The common cross-cultural themes comprise a framework underpinned by value placed on personhood and dignity, emphasizing that interdependency through relationships is essential to promote a good end of life with dementia. These themes and valuing the importance of relationships as central to connecting the themes could support care planning and further development of a dementia palliative care model. TRIAL REGISTRATION: The Graduate School and Faculty of Medicine Kyoto University (R1924-1).
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Demencia , Cuidado Terminal , Cuidadores , Formación de Concepto , Comparación Transcultural , Muerte , Demencia/terapia , Humanos , Investigación Cualitativa , Cuidado Terminal/métodosRESUMEN
OBJECTIVES: To conceptualize a "good end of life" for people with dementia from the perspectives of bereaved family caregivers in Japan. DESIGN AND PARTICIPANTS: A qualitative study using in-depth, semi-structured interviews focused on the family caregivers' perceptions of their loved one's experiences. Family caregivers who had lost their relatives with dementia more than six months previously were recruited using maximum variation sampling by cultural subpopulation. A thematic analysis was conducted. RESULTS: From 30 interviews held, four main themes emerged. A good end of life for people with dementia means experiencing a "Peaceful Death" while "Maintaining Personhood" at a "Preferred Place" allowing for feelings of "Life Satisfaction." A "Preferred Place" emerged as a basic requirement to achieving a good end of life according to the three other themes, in particular, "Maintaining Personhood." However, the interviewees experienced difficulties in ensuring that their loved ones stayed at a "Preferred Place." CONCLUSIONS: Despite different cultural backgrounds, perceptions of a good end of life with dementia were remarkably similar between Japan and Western countries. However, recent societal changes in family structures and long-term care access in Japan may explain the theme of a comfortable place taking a central position. We suggest that these themes be considered and translated into care goals. They could supplement established end-of-life care goals for quality of life in dementia, which aim to maximize functioning and increase comfort. TRIAL REGISTRATION NUMBER: Ethics Committee of the Graduate School and Faculty of Medicine, Kyoto University (R0808-2).
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Cuidadores/psicología , Formación de Concepto , Demencia , Calidad de Vida , Cuidado Terminal , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Entrevistas como Asunto , Japón , Masculino , Investigación CualitativaRESUMEN
As classical transplantation repopulation assays for studying the radiobiology of rat mammary stem/progenitor cells are extremely time-consuming, this study aimed to characterize the radiobiological properties of mammospheres, spherical clumps of mammary cells formed under non-adherent culture conditions, which are a simple and widely used technique for assessing progenitor cell activity. Rat mammary cells were dissociated and used in transplantation repopulation assays and for the formation of mammospheres. Immunofluorescence for cytokeratin 14 and 18 was used to identify basal and luminal mammary epithelial cells, respectively. Incorporation of 5-bromo-2'-deoxyuridine was used to evaluate cell proliferation. The repopulating activity of the transplanted primary rat mammary cells demonstrated their radiosensitivity, reproducing previous data, with a significant reduction in repopulating activity at ≥ 2 Gy. Cells constituting rat mammospheres were positive for either cytokeratin 14 or 18, with occasional double-positive cells. Both proliferation and aggregation contributed to sphere formation. Cells obtained from the spheres showed lower repopulating activity after transplantation than primary cells. When primary cells were irradiated and then used for sphere formation, the efficiency of sphere formation was significantly decreased at 8 Gy but not at ≤ 6 Gy, indicating radioresistance of the formation process. Irradiation at 8 Gy reduced the proliferation of cells during sphere formation, whereas the cellular composition of the resulting spheres was unaffectes. Thus, mammosphere formation assays may measure a property of putative mammary progenitors that is different from what is measured in the classic transplantation repopulation assay in radiobiology.
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Radioisótopos de Cesio , Células Epiteliales/efectos de la radiación , Rayos gamma , Glándulas Mamarias Animales/citología , Animales , Agregación Celular , Proliferación Celular , Células Epiteliales/trasplante , Femenino , Tolerancia a Radiación , Ratas Endogámicas Lew , Ratas TransgénicasRESUMEN
Biallelic germline mutations in the DNA mismatch repair gene MLH1 lead to constitutional mismatch repair-deficiency syndrome and an increased risk for childhood hematopoietic malignancies, including lymphoma and leukemia. To examine how Mlh1 dysfunction promotes lymphoma as well as the influence of ionizing radiation (IR) exposure, we used an Mlh1-/- mouse model and whole-exome sequencing to assess genomic alterations in 23 T-cell lymphomas, including 8 spontaneous and 15 IR-associated lymphomas. Exposure to IR accelerated T-cell lymphoma induction in the Mlh1-/- mice, and whole-exome sequencing revealed that IR exposure neither increased the number of mutations nor altered the mutation spectrum of the lymphomas. Frequent mutations were evident in genes encoding transcription factors (e.g. Ikzf1, Trp53, Bcl11b), epigenetic regulators (e.g. Suv420h1, Ep300, Kmt2d), transporters (e.g. Rangap1, Kcnj16), extracellular matrix (e.g. Megf6, Lrig1), cell motility (e.g. Argef19, Dnah17), protein kinase cascade (e.g. Ptpro, Marcks) and in genes involved in NOTCH (e.g. Notch1), and PI3K/AKT (e.g. Pten, Akt2) signaling pathways in both spontaneous and IR-associated lymphomas. Frameshift mutations in mononucleotide repeat sequences within the genes Trp53, Ep300, Kmt2d, Notch1, Pten and Marcks were newly identified in the lymphomas. The lymphomas also exhibited a few chromosomal abnormalities. The results establish a landscape of genomic alterations in spontaneous and IR-associated lymphomas that occur in the context of mismatch repair dysfunction and suggest potential targets for cancer treatment.
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Reparación de la Incompatibilidad de ADN/genética , Mutación del Sistema de Lectura/genética , Mutación de Línea Germinal/genética , Linfoma de Células T/genética , Homólogo 1 de la Proteína MutL/genética , Animales , Epigénesis Genética/genética , Proteínas de Transporte de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Radiación Ionizante , Transducción de Señal/genética , Factores de Transcripción/genéticaRESUMEN
Whole body irradiation causes significant apoptosis in various tissues such as the thymus. If apoptotic cells outnumber the phagocytic capacity of macrophages, apoptosis becomes secondary necrosis, inducing inflammatory cytokine expression in macrophages. Radiation also induces thymic lymphomas in C57BL/6 mice after four consecutive irradiations with 1.6â¯Gy X-rays with nearly 100% incidence. Since cancer development is modulated by a microenvironment involving macrophages, we examined the kinetics of thymocyte number and plastic adherent cell number in the thymus as well as cytokine mRNA expression by plastic adherent cells in the thymus after split-dose irradiation. Upon split-dose irradiation, thymocyte number changed dramatically, whereas plastic adherent cell number did not. Among cytokine mRNAs tested, IL-1ß, IL-11 and IL-12p40 mRNAs were up regulated 2â¯days after the 1st and 2nd, 3rd and 4th, and 2nd and 3rd irradiations, respectively. On the other hand, TNF-α mRNA was up regulated 2â¯days after the 3rd irradiation and 2â¯weeks after the 4th irradiation. The level of IL-11 protein was also increased 2â¯days after 3rd and 4th irradiations. These results suggest that, upon split-dose irradiation, macrophages in the thymus produce various cytokines in a time-dependent manner, thereby contributing to induction of thymic lymphomas.
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Citocinas/genética , Plásticos/farmacología , Dosis de Radiación , Timo/citología , Timo/efectos de la radiación , Animales , Adhesión Celular/efectos de los fármacos , Adhesión Celular/genética , Recuento de Células , Citocinas/sangre , Citocinas/metabolismo , Femenino , Cinética , Ratones Endogámicos C57BL , Fagocitosis/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Timocitos/citología , Timocitos/metabolismo , Timocitos/efectos de la radiaciónRESUMEN
With the increase in the number of long-term cancer survivors worldwide, there is a growing concern about the risk of secondary cancers induced by radiotherapy. Epigenetic modifications of genes associated with carcinogenesis are attractive targets for the prevention of cancer owing to their reversible nature. To identify genes with possible changes in functionally relevant DNA methylation patterns in mammary carcinomas induced by radiation exposure, we performed microarray-based global DNA methylation and expression profiling in γ-ray-induced rat mammary carcinomas and normal mammary glands. The gene expression profiling identified dysregulation of developmentally related genes, including the downstream targets of polycomb repressive complex 2 (PRC2) and overexpression of enhancer of zeste homolog 2, a component of PRC2, in the carcinomas. By integrating expression and DNA methylation profiles, we identified ten hypermethylated and three hypomethylated genes that possibly act as tumor-suppressor genes and oncogenes dysregulated by aberrant DNA methylation; half of these genes encode developmental transcription factors. Bisulfite sequencing and quantitative PCR confirmed the dysregulation of the polycomb-regulated developmentally related transcription-factor genes Dmrt2, Hoxa7, Foxb1, Sox17, Lhx8, Gata3 and Runx1. Silencing of Hoxa7 was further verified by immunohistochemistry. These results suggest that, in radiation-induced mammary gland carcinomas, PRC2-mediated aberrant DNA methylation leads to dysregulation of developmentally related transcription-factor genes. Our findings provide clues to molecular mechanisms linking epigenetic regulation and radiation-induced breast carcinogenesis and underscore the potential of such epigenetic mechanisms as targets for cancer prevention.
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Metilación de ADN/efectos de la radiación , Perfilación de la Expresión Génica/métodos , Neoplasias Mamarias Experimentales/genética , Neoplasias Inducidas por Radiación/genética , Análisis de Secuencia de ADN/métodos , Animales , Proteína Potenciadora del Homólogo Zeste 2/genética , Epigénesis Genética/efectos de la radiación , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Complejo Represivo Polycomb 2/genética , Ratas , Factores de Transcripción/genéticaRESUMEN
Genetic, physiological and environmental factors are implicated in colorectal carcinogenesis. Mutations in the mutL homolog 1 (MLH1) gene, one of the DNA mismatch repair genes, are a main cause of hereditary colon cancer syndromes such as Lynch syndrome. Long-term chronic inflammation is also a key risk factor, responsible for colitis-associated colorectal cancer; radiation exposure is also known to increase colorectal cancer risk. Here, we studied the effects of radiation exposure on inflammation-induced colon carcinogenesis in DNA mismatch repair-proficient and repair-deficient mice. Male and female Mlh1(-/-) and Mlh1(+/+) mice were irradiated with 2 Gy X-rays when aged 2 weeks or 7 weeks and/or were treated with 1% dextran sodium sulfate (DSS) in drinking water for 7 days at 10 weeks old to induce mild inflammatory colitis. No colon tumors developed after X-rays and/or DSS treatment in Mlh1(+/+) mice. Colon tumors developed after DSS treatment alone in Mlh1(-/-) mice, and exposure to radiation prior to DSS treatment increased the number of tumors. Histologically, colon tumors in the mice resembled the subtype of well-to-moderately differentiated adenocarcinomas with tumor-infiltrating lymphocytes of human Lynch syndrome. Immunohistochemistry revealed that expression of both p53 and ß-catenin and loss of p21 and adenomatosis polyposis coli proteins were observed at the later stages of carcinogenesis, suggesting a course of molecular pathogenesis distinct from typical sporadic or colitis-associated colon cancer in humans. In conclusion, radiation exposure could further increase the risk of colorectal carcinogenesis induced by inflammation under the conditions of Mlh1 deficiency.
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Proteínas Adaptadoras Transductoras de Señales/deficiencia , Proteínas Adaptadoras Transductoras de Señales/genética , Adenocarcinoma/genética , Carcinogénesis/genética , Neoplasias del Colon/genética , Proteínas Nucleares/deficiencia , Proteínas Nucleares/genética , Adenocarcinoma/inducido químicamente , Proteína de la Poliposis Adenomatosa del Colon/biosíntesis , Proteína de la Poliposis Adenomatosa del Colon/genética , Animales , Carcinogénesis/inmunología , Carcinogénesis/efectos de la radiación , Colitis/inducido químicamente , Neoplasias del Colon/inducido químicamente , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/biosíntesis , Reparación de la Incompatibilidad de ADN/genética , Sulfato de Dextran/farmacología , Modelos Animales de Enfermedad , Femenino , Inflamación/inducido químicamente , Inflamación/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Homólogo 1 de la Proteína MutL , Radiación Ionizante , Proteína p53 Supresora de Tumor/biosíntesis , beta Catenina/biosíntesisRESUMEN
BACKGROUND: We previously reported that dietary glucosylceramides show cancer-prevention activity in a mouse xenograft model of human head and neck cancer cells (SCCKN). However, the mechanism was unclear. Ceramides, metabolites of glucosylceramides, induce apoptotic cell death in various malignancies. Here, we investigated the inhibitory effects of dietary glucosylceramides on tumor growth in vivo and in vitro. METHODS: SCCKN were subcutaneously inoculated into the right flanks of NOD/SCID mice. Mice were treated with or without dietary glucosylceramides (300 mg/kg) daily for 14 consecutive days after confirmation of tumor progression. Microvessel areas around the tumor were assessed by hematoxylin-eosin staining and immunohistochemistry of CD31, and, as markers for angiogenesis, protein levels of VEGF, VEGF receptor-2, and HIF-1α were assessed by Western blotting. Mass spectrometry was performed to measure the levels of sphingolipids in mouse serum after treatment with dietary glucosylceramides. RESULTS: Oral administration of glucosylceramides significantly decreased SCCKN growth in the xenograft model with inhibition of angioinvasion. In tumor-invasive areas, VEGF and HIF-1α in the tumor cells, and VEGF receptor-2 in endothelial cells decreased after treatment with dietary glucosylceramides. Dietary glucosylceramides increased serum levels of sphingosine-based ceramides as compared to the control. In SCCKN and UVâ2 cells, C6-ceramide suppressed the expressions of VEGF, VEGF receptor-2, and HIF-1α in vitro. CONCLUSION: These results suggest that dietary glucosylceramides trigger the de novo pathway of ceramide synthesis, indicating that sphingosine-based ceramide suppresses the growth of head and neck tumors through the inhibition of pro-angiogenic signals such as VEGF, VEGF receptor-2, and HIF-1α.
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Inhibidores de la Angiogénesis/administración & dosificación , Carcinoma de Células Escamosas/dietoterapia , Glucosilceramidas/administración & dosificación , Neoplasias de Cabeza y Cuello/dietoterapia , Neovascularización Patológica/dietoterapia , Administración Oral , Animales , Carcinoma de Células Escamosas/metabolismo , Ceramidas/biosíntesis , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/biosíntesis , Ratones , Ratones Endogámicos NOD , Ratones SCID , Neovascularización Patológica/metabolismo , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Receptor 2 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Although various mechanisms have been inferred for combinatorial actions of multiple carcinogens, these mechanisms have not been well demonstrated in experimental carcinogenesis models. We evaluated mammary carcinogenesis initiated by combined exposure to various doses of radiation and chemical carcinogens. Female rats at 7 weeks of age were γ-irradiated (0.2-2 Gy) and/or exposed to 1-methyl-1-nitrosourea (MNU) (20 or 40 mg/kg, single intraperitoneal injection) or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) (40 mg/kg/day by gavage for 10 days) and were observed until 50 weeks of age. The incidence of mammary carcinoma increased steadily as a function of radiation dose in the absence of chemicals; mathematical analysis supported an additive increase when radiation was combined with a chemical carcinogen, irrespective of the chemical species and its dose. Hras mutations were characteristic of carcinomas that developed after chemical carcinogen treatments and were overrepresented in carcinomas induced by the combination of radiation and MNU (but not PhIP), indicating an interaction of radiation and MNU at the level of initiation. The expression profiles of seven classifier genes, previously shown to distinguish two classes of rat mammary carcinomas, categorized almost all examined carcinomas that developed after individual or combined treatments with radiation (1 Gy) and chemicals as belonging to a single class; more comprehensive screening using microarrays and a separate test sample set failed to identify differences in gene expression profiles among these carcinomas. These results suggest that a complex, multilevel interaction underlies the combinatorial action of radiation and chemical carcinogens in the experimental model.
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Carcinogénesis/efectos de los fármacos , Carcinogénesis/efectos de la radiación , Carcinógenos/toxicidad , Neoplasias Mamarias Experimentales/etiología , Neoplasias Inducidas por Radiación/etiología , Radiación Ionizante , Animales , Carcinogénesis/genética , Femenino , Imidazoles/efectos adversos , Incidencia , Neoplasias Mamarias Experimentales/inducido químicamente , Neoplasias Mamarias Experimentales/genética , Modelos Biológicos , Neoplasias Inducidas por Radiación/inducido químicamente , Compuestos de Nitrosourea/toxicidad , Proteínas Oncogénicas/genética , Ratas , Ratas Sprague-Dawley , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Transcriptoma/efectos de la radiación , Proteínas ras/genéticaRESUMEN
OBJECTIVE: Checkpoint kinase (Chk) inhibitors are thought to increase the cytotoxic effects of DNA-damaging agents and are undergoing clinical trials. The present study was aimed to assess the potential to use the Chk1 and Chk2 inhibitor, AZD7762, with other anticancer agents in chemotherapy to treat ovarian clear cell carcinoma. METHODS: Four ovarian clear cell carcinoma cell lines were used in this study. We treated the cells with AZD7762 and anticancer agents, then assessed cell viability, cell cycle distribution, apoptosis, and the expression of protein in apoptotic pathways and molecules downstream of the Chk signaling pathways. We also investigated the effects of these drug combinations on tumor growth in a nude mouse xenograft model. RESULTS: Synergistic effects from the combination of AZD7762 and cisplatin were observed in all 4 cell lines. However, we observed additive effects when AZD7762 was combined with paclitaxel on all cell lines tested. AZD7762 effectively suppressed the Chk signaling pathways activated by cisplatin, dramatically enhanced expression of phosphorylated H2A.X, cleaved caspase 9 and PARP, decreased the proportion of cells in the gap 0/ gap 1 phase and the synthesis-phase fraction, and increased apoptotic cells. Combinations of small interfering RNA against Chk 1 and small interfering RNA against Chk2 enhanced the cytotoxic effect of cisplatin in both RMG-I and KK cells. Finally, treating mice-bearing RMG-I with AZD7762 and cisplatin significantly suppressed growth of tumors in a xenograft model. CONCLUSIONS: The present study indicates that chemotherapy with AZD7762 and cisplatin should be explored as a treatment modality for women with ovarian clear cell carcinoma.
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Adenocarcinoma de Células Claras/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Cisplatino/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Neoplasias Ováricas/tratamiento farmacológico , Tiofenos/uso terapéutico , Urea/análogos & derivados , Animales , Línea Celular Tumoral , Sinergismo Farmacológico , Femenino , Ratones , Ratones Desnudos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Tiofenos/farmacología , Urea/farmacología , Urea/uso terapéutico , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: During the COVID-19 pandemic, numerous issues regarding end-of-life care for COVID-19 patients have been discussed. Among these issues, challenges related to the use of body bags following the death of COVID-19 patients have been suggested. This study aimed to identify the challenges faced by healthcare professionals (HCPs) when using body bags after the death of patients infected with COVID-19 in medical settings. METHODS: We conducted a qualitative descriptive study with semistructured in-depth interviews using inductive thematic analysis. From August to December 2021, we interviewed nurses and doctors who provided end-of-life care to COVID-19 patients focusing on their experiences with the use of body bags for the deceased. RESULTS: Of the 25 interviewees who mentioned body bag use, 14 were nurses (56%) and 13 were women (52%). The mean interview length was 52.0 min (SD 9.6 min). Challenges associated with body bag use were classified into four themes with eight categories: preserving the dignity of the deceased, consideration for the bereaved saying a final goodbye to a loved one in a body bag, the physical and emotional impact on HCPs, and diverse opinions on body bag use. CONCLUSION: Our findings include ethical concerns about the dignity of the deceased, empathy for the grief of bereaved families, and the emotional and physical distress experienced by HCPs struggling with the recommendation to use body bags based on limited evidence. The diverse perspectives of HCPs in this study highlight potential issues that developers should consider when formulating more appropriate and acceptable guidelines/guidance and policies.
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COVID-19 , Médicos , Cuidado Terminal , Humanos , Femenino , Masculino , Pandemias , Personal de SaludRESUMEN
Ionizing radiation promotes mammary carcinogenesis. Induction of DNA double-strand breaks (DSBs) is the initial event after radiation exposure, which can potentially lead to carcinogenesis, but the dynamics of DSB induction and repair are not well understood at the tissue level. In this study, we used female rats, which have been recognized as a useful experimental model for studying radiation effects on the mammary gland. We focused on differences in DSB kinetics among basal cells, luminal progenitor and mature cells in different parts of the mammary duct. 53BP1 foci were used as surrogate markers of DSBs, and 53BP1 foci in each mammary epithelial cell in immunostained tissue sections were counted 1-24 h after irradiation and fitted to an exponential function of time. Basal cells were identified as cytokeratin (CK) 14+ cells, luminal progenitor cells as CK8 + 18low cells and luminal mature cells as CK8 + 18high cells. The number of DSBs per nucleus tended to be higher in luminal cells than basal cells at 1 h post-irradiation. A model analysis indicated that basal cells in terminal end buds (TEBs), which constitute the leading edge of the mammary duct, had significantly fewer initial DSBs than the two types of luminal cells, and there was no significant difference in initial amount among the cell types in the subtending duct. The repair rate did not differ among mammary epithelial cell types or their locations. Thus, luminal progenitor and mature cells are more susceptible to radiation-induced DSBs than are basal cells in TEBs.
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The relative biological effectiveness (RBE) of densely ionizing radiation can depend on the biological context. From a radiological perspective, age is an important factor affecting health risks of radiation exposure, but little is known about the modifying impact of age on the effects of densely ionizing radiation. Herein, we addressed the influence of age on leukemogenesis induced by accelerator-generated fast neutrons (mean energy, â¼2 MeV). Male C3H/HeNrs mice were exposed to 137Cs γ rays (0.2-3.0 Gy) or neutrons (0.0485-0.97 Gy, γ ray contamination 0.0105-0.21 Gy) at 1, 3, 8, or 35 weeks of age and observed over their lifetimes under specific pathogen-free conditions. Leukemia and lymphoma were diagnosed pathologically. Hazard ratio (HR) and RBE for myeloid leukemia mortality as well as the age dependence of these two parameters were modeled and analyzed using Cox regression. Neutron exposure increased HR concordant with a linear dose response. The increase of HR per dose depended on age at exposure, with no significant dose dependence at age 1 or 3 weeks but a significant increase in HR of 5.5 per Gy (γ rays) and 16 per Gy (neutrons) at 8 weeks and 5.8 per Gy (γ rays) and 9 per Gy (neutrons) at 35 weeks. The RBE of neutrons was 2.1 (95% confidence interval, 1.1-3.7), with no dependence on age. The development of lymphoid neoplasms was not related to radiation exposure. The observed increasing trend of radiation-associated mortality of myeloid leukemia with age at exposure supports previous epidemiological and experimental findings. The results also suggest that exposure at the susceptible age of 8 or 35 weeks does not significantly influence the RBE value for neutrons for induction of leukemia, unlike what has been documented for breast and brain tumors.
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The role of "sphingolipid rheostat" by ceramide and sphingosine 1-phosphate (S1P) in the regulation of autophagy remains unclear. In human leukemia HL-60 cells, amino acid deprivation (AA(-)) caused autophagy with an increase in acid sphingomyleinase (SMase) activity and ceramide, which serves as an autophagy inducing lipid. Knockdown of acid SMase significantly suppressed the autophagy induction. S1P treatment counteracted autophagy induction by AA(-) or C(2)-ceramide. AA(-) treatment promoted mammalian target of rapamycin (mTOR) dephosphorylation/inactivation, inducing autophagy. S1P treatment suppressed mTOR inactivation and autophagy induction by AA(-). S1P exerts biological actions via cell surface receptors, and S1P(3) among five S1P receptors was predominantly expressed in HL-60 cells. We evaluated the involvement of S1P(3) in suppressing autophagy induction. S1P treatment of CHO cells had no effects on mTOR inactivation and autophagy induction by AA(-) or C(2)-ceramide. Whereas S1P treatment of S1P(3) overexpressing CHO cells resulted in activation of the mTOR pathway, preventing cells from undergoing autophagy induced by AA(-) or C(2)-ceramide. These results indicate that S1P-S1P(3) plays a role in counteracting ceramide signals that mediate mTOR-controlled autophagy. In addition, we evaluated the involvement of ceramide-activated protein phosphatases (CAPPs) in ceramide-dependent inactivation of the mTOR pathway. Inhibition of CAPP by okadaic acid in AA(-)- or C(2)-ceramide-treated cells suppressed dephosphorylation/inactivation of mTOR, autophagy induction, and autophagy-associated cell death, indicating a novel role of ceramide-CAPPs in autophagy induction. Moreover, S1P(3) engagement by S1P counteracted cell death. Taken together, these results indicated that sphingolipid rheostat in ceramide-CAPPs and S1P-S1P(3) signaling modulates autophagy and its associated cell death through regulation of the mTOR pathway.
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Autofagia/fisiología , Ceramidas/metabolismo , Lisofosfolípidos/metabolismo , Transducción de Señal/fisiología , Esfingosina/análogos & derivados , Serina-Treonina Quinasas TOR/metabolismo , Animales , Células CHO , Ceramidas/genética , Cricetinae , Cricetulus , Técnicas de Silenciamiento del Gen , Células HL-60 , Humanos , Lisofosfolípidos/genética , Fosfoproteínas Fosfatasas/genética , Fosfoproteínas Fosfatasas/metabolismo , Fosforilación/fisiología , Receptores de Lisoesfingolípidos/genética , Receptores de Lisoesfingolípidos/metabolismo , Esfingomielina Fosfodiesterasa/genética , Esfingomielina Fosfodiesterasa/metabolismo , Esfingosina/genética , Esfingosina/metabolismo , Serina-Treonina Quinasas TOR/genéticaRESUMEN
Cancer risk associated with radiation exposure is considered the result of concurrent exposure to other natural and manmade carcinogens. Available data on the molecular characteristics of cancer after simultaneous exposure to radiation and chemicals are insufficient. In our study, we used a mouse thymic lymphoma (TL) model that was synergistically induced by simultaneous exposure to X-rays and N-ethyl-N-nitrosourea (ENU) at subcarcinogenic doses and analyzed the mutation frequency and spectrum of the TL-associated genes Ikaros, Notch1, p53 and Kras. We found that the point mutation frequency in Ikaros was significantly increased to 47% for simultaneous exposure compared to 13 and 0% for X-ray and ENU exposure alone, respectively. These mutations were mostly G:C > A:T at non-CpG sites and T:A > C:G, both of which are characteristic of ENU mutagenesis. About half of the point mutations were accompanied by loss of heterozygosity (LOH), typical of X-irradiation. The remaining half did not include LOH, which suggests that they were dominant-negative mutations. In Notch1, the frequency of abnormalities was high (>58%) regardless of the treatment, suggesting that Notch1 aberration may be important for T-cell lymphomagenesis. The p53 and Kras mutation frequencies were low for all treatments (<23%). Importantly, the frequency of TLs containing mutations in multiple genes, especially both Ikaros and Notch1, increased after simultaneous exposure. Thus, after simultaneous exposure, Ikaros is a critical target and is inactivated by ENU-induced point mutations and/or X-ray-induced LOH in T-cell lymphomagenesis. Furthermore, concomitant alterations of multiple tumor-associated genes may contribute to enhanced lymphomagenesis after simultaneous exposure.
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Transformación Celular Neoplásica/genética , Factor de Transcripción Ikaros/genética , Linfoma de Células T/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Sitios de Unión , Transformación Celular Neoplásica/efectos de la radiación , Análisis Mutacional de ADN , Etilnitrosourea , Femenino , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Pérdida de Heterocigocidad , Linfoma de Células T/inducido químicamente , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Mutación Puntual , Proteínas Proto-Oncogénicas p21(ras)/genética , Receptor Notch1/genética , Factor de Transcripción HES-1 , Transcripción Genética , Proteína p53 Supresora de Tumor/genética , Rayos XRESUMEN
Assessment of risks associated with childhood exposure to ionizing radiation when combined with chemical carcinogens is of great importance. We studied the age-dependence of the effect of combined exposure to ionizing radiation (IR) and a chemical carcinogen on lung carcinogenesis. Female 1-, 5-, and 22-week-old Wistar rats were locally irradiated on the thorax with X-rays (3.18 Gy) and/or were injected intraperitoneally with N-nitrosobis(2-hydroxypropyl)amine (BHP) (1g/kg body weight) 1 week after X-ray exposure or at 23 weeks of age. Rats were terminated at 90 weeks of age. We found that: (i) the incidence of lung tumors (adenoma and adenocarcinoma) increased slightly as a function of age at X-ray exposure, although this was not statistically significant, while the incidence induced by BHP decreased with increasing age at administration; (ii) combined exposure to X-rays at 5 or 22 weeks with BHP 1 week later enhanced the tumor incidence, and the effect at early-life stage (5 weeks irradiation) was more effective than that at late-life stage (22 weeks irradiation); (iii) combined exposure preferentially enhanced malignant transformation; (iv) although a longer interval between the X-ray and BHP treatments reduced the combined effect, risks of early-life irradiation at 1 or 5 weeks of age lasted into adulthood; (v) adenomas and adenocarcinomas induced by X-ray and/or BHP originated from surfactant apoprotein A-positive alveolar type II cells; and (vi), extracellular signal-regulated kinase pathway activation was observed in half the adenocarcinomas, regardless of the exposure schedule. In conclusion, combined exposure may enhance lung tumorigenesis more synergistically at early-life stage (5 weeks of age) than later-life stage.