24 research outputs found

    Effective Alu repeat based RT-qPCR normalization in cancer cell perturbation experiments

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    Background: Measuring messenger RNA (mRNA) levels using the reverse transcription quantitative polymerase chain reaction (RT-qPCR) is common practice in many laboratories. A specific set of mRNAs as internal control reference genes is considered as the preferred strategy to normalize RT-qPCR data. Proper selection of reference genes is a critical issue, especially in cancer cells that are subjected to different in vitro manipulations. These manipulations may result in dramatic alterations in gene expression levels, even of assumed reference genes. In this study, we evaluated the expression levels of 11 commonly used reference genes as internal controls for normalization of 19 experiments that include neuroblastoma, T-ALL, melanoma, breast cancer, non small cell lung cancer (NSCL), acute myeloid leukemia (AML), prostate cancer, colorectal cancer, and cervical cancer cell lines subjected to various perturbations. Results: The geNorm algorithm in the software package qbase+ was used to rank the candidate reference genes according to their expression stability. We observed that the stability of most of the candidate reference genes varies greatly in perturbation experiments. Expressed Alu repeats show relatively stable expression regardless of experimental condition. These Alu repeats are ranked among the best reference assays in all perturbation experiments and display acceptable average expression stability values (M<0.5). Conclusions: We propose the use of Alu repeats as a reference assay when performing cancer cell perturbation experiments

    In silico discovery of a FOXM1 driven embryonal signaling pathway in therapy resistant neuroblastoma tumors

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    Chemotherapy resistance is responsible for high mortality rates in neuroblastoma. MYCN, an oncogenic driver in neuroblastoma, controls pluripotency genes including LIN28B. We hypothesized that enhanced embryonic stem cell (ESC) gene regulatory programs could mark tumors with high pluripotency capacity and subsequently increased risk for therapy failure. An ESC miRNA signature was established based on publicly available data. In addition, an ESC mRNA signature was generated including the 500 protein coding genes with the highest positive expression correlation with the ESC miRNA signature score in 200 neuroblastomas. High ESC m(i)RNA expression signature scores were significantly correlated with poor neuroblastoma patient outcome specifically in the subgroup of MYCN amplified tumors and stage 4 nonamplified tumors. Further data-mining identified FOXM1, as the major predicted driver of this ESC signature, controlling a large set of genes implicated in cell cycle control and DNA damage response. Of further interest, re-analysis of published data showed that MYCN transcriptionally activates FOXM1 in neuroblastoma cells. In conclusion, a novel ESC m(i)RNA signature stratifies neuroblastomas with poor prognosis, enabling the identification of therapy-resistant tumors. The finding that this signature is strongly FOXM1 driven, warrants for drug design targeted at FOXM1 or key components controlling this pathway

    Aspectos reprodutivos de ratos machos submetidos ao bloqueio androgênico perinatal por flutamida

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    A aromatização da testosterona a estradiol é essencial para a diferenciação sexual do cérebro, o qual está organizado intrinsecamente no tipo feminino, organizando-o então no tipo masculino. Trabalhos em nosso laboratório, no entanto, apontam para existência de vias metabólicas adicionais para os androgênios neste processo, sugerindo a atuação do hormônio masculino per se. Dessa forma, no presente estudo investigou-se o papel da testosterona, durante a fase crítica de diferenciação sexual hipotalâmica, em ratos machos. Para isso, ratas Wistar prenhes receberam 15mg/kg/dia do anti-androgênico flutamida (grupo Flutamida) ou óleo de amendoim (grupo Controle), s.c., no 19º e no 22º dias de gestação, bem como durante os cinco primeiros dias após o parto. Foram avaliados efeitos imediatos e, principalmente, tardios do bloqueio androgênico sobre parâmetros reprodutivos, sexuais e de desenvolvimento físico da prole masculina. Assim, a exposição perinatal a flutamida levou à redução do peso corporal ao desmame, aumento do peso corporal ao atingir a puberdade, redução da distância anogenital (DAG) ao nascimento, retardo para a instalação da puberdade, diminuição dos pesos úmidos dos testículos e da próstata ventral, aumento do peso úmido do epidídimo e menor índice gônado-somático na vida adulta. Fêmeas não tratadas acasaladas com os machos do grupo Flutamida apresentaram reduzidas taxas de implantação, maiores taxas de perdas pré-implantação e baixa taxa de fertilidade, resultando em reduzido número de descendentes. Frente a uma fêmea receptiva normal, os animais do grupo Flutamida apresentaram maior latência para o início da cópula, realizaram maior número de montas sem intromissão peniana, maior número de intromissões até a 1ª ejaculação, com maior latência para a 1ª ejaculação, além de não ejacularem ou ejacularem uma...Studies in our laboratory indicate the existence of additional pathways for androgens in THE process of sexual differentiation, suggesting the importance of the male hormone per se. Thus, the present study investigated the role of testosterone during the critical phase of sexual differentiation of hypothalamus in male rats. Therefore, pregnant Wistar rats received 15mg/kg/day of flutamide (Flutamide group) or peanut oil (Control group), s.c. at day 19 of pregnancy and for the first five postnatal days. The perinatal exposure to flutamide led to a reduction in body weight at weaning, aN augmentation in body weight at puberty, reduction in anogenital distance at birth, delay in the puberty installation, decrease in wet weight of testes and ventral prostate, increase in wet weight of epididymis and decrease in gonadosomatic index. Normal females mated with treated males presented more pre-implantation losses, reduced implantation rates, and consequently reduced offspring size. Flutamide group showed increases in latency to copulatory behavior, number of mounts without penis intromission, number of intromissions until ejaculation, latency to ejaculation, and reduced number of ejaculations. after Castration followed by estrogenization, 45.5% of the animals took lying down the mounts of a non-experimental male. Flutamide treated rats presented reductions in percentage of normal spermatozoa, spermatozoa concentration, and daily testicular sperm production. The height of the epithelium of the ventral prostate was not altered by treatment, although there was a 10% reduction in cell nuclei prostatic epithelial marked positively for androgen receptor (AR) and a 60% reduction in plasma testosterone during the adulthood. Thus, the present results indicated that perinatal androgen blockage damaged differentiation process of the brain and peripheral reproductive structures. Thus, the binding ... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Efeitos da corticoterapia pré-natal e durante a puberdade sobre a morfofisiologia do lobo ventral da próstata de ratos senis

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    Studies have suggested that glucocorticoids (GCs) excess during critical developmental time windows can alter reproductive parameters. Despite of the key function of the prostate in the reproductive success, and its high susceptibility to develop lesions in an age-dependent manner, the impact of early GCs excess on the gland homeostasis is still unknown. In the present study, we have investigated the effects of prenatal (PRE), peripubertal (PU) corticotherapy, and its combination (PRE+PU=REE), on aging prostate´s morphophysiology. Pregnant Wistar rats received betamethasone (0.1mg/kg/day, i.m.), or saline, on the gestational days 12, 13, 18 and 19. Male descendents received betamethasone (7mg/kg/day, gavage), or saline, from 35th to 50th postnatal day (PND35-50). Late in life (PND300), all animals were euthanized, blood samples were taken for hormones levels estimation, and the ventral prostate (VP) was excised and processed for morphology evaluation, and for proteins (AR, GR, PAR-4 and PCNA) quantification and localization as well. Lower testosterone and insulin levels were detected in group PRE, while only insulin serum levels was reduced in group PU, and no additional decrease was seen in REE. An increasing trend in the apoptosis index and metaplastic epithelium acini incidence was observed along the treated groups. The protein quantifications showed a decreased AR expression in PRE, higher proliferation marker (PCNA) expression in REE, and no significant difference in the expression of the apoptosis marker PAR-4 was detected among the groups. The immunolocalization of GR indicated a higher receptor expression in epithelial cells of treated groups, when compared to NE. Based on these results, we suggest that the corticotherapy with betamethasone during late pregnancy can program fetal prostate, resulting in altered androgen and glucocorticoids signaling permanently. Peripubertal corticotherapy deflagrated cell ...Estudos têm sugerido que o excesso de glicocorticoides (GCs) durante períodos críticos do desenvolvimento pode alterar a função reprodutiva. Apesar da função essencial da próstata no sucesso reprodutivo e de sua alta susceptibilidade ao desenvolvimento de lesões com o avançar da idade, o impacto tardio de corticoterapias precoces sobre a homeostase da glândula ainda é desconhecido. No presente estudo, investigamos os efeitos da corticoterapia prenatal (PRE), durante a instalação da puberdade (PU), e sua associação (PRE+PU=REE), sobre a morfofisiologia da próstata senescente. Ratas Wistar prenhes receberam betametasona (0.1mg/kg/dia, i.m.), ou salina, nos dias gestacionais 12, 13, 18 e 19. Os descendentes machos receberam doses de betametasona (7mg/kg/dia, gavage), ou salina, do dia pós-natal 35 ao 50 (PND35-50). Na idade senil (PND300), todos os animais foram eutanasiados, amostras de sangue foram coletadas para dosagens hormonais, e a próstata ventral (VP) foi dissecada e processada para a análise morfológica, bem como para quantificação e localização de proteínas (AR, GR, PAR-4 e PCNA). Reduzidos níveis de testosterona e insulina foram observados no grupo PRE, enquanto apenas a insulina mostrou-se reduzida no grupo PU, e nenhuma redução adicional foi observada em REE. Uma tendência de aumento no índice apoptótico e incidência de ácinos com epitélio metaplásico foi detectada dentre os grupos. A quantificação de proteínas revelou menor expressão de AR no grupo PRE, maior expressão do marcador de proliferação celular (PCNA) no grupo REE, porém, diferença significativa alguma foi observada na expressão do marcador de morte celular por apoptose (PAR-4). A análise da reação imunoistoquímica para o GR indicou uma maior expressão do receptor em células epiteliais dos grupos que receberam betametasona. Com base nos resultados, sugerimos que a corticoterapia com betametasona durante o final da ...Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Estrogen imprinting compromises male sexual behavior and affects the number of androgen-receptor-expressing hypothalamic neurons

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    Neonatal exposure to high-dose 17 beta-estradiol (E2) affects the morphology and physiology of sex and accessory sex organs in the long term. In this study, we examined the effects of E2 imprinting on male sexual behavior, fertility, and the number of androgen receptor (AR)-expressing cells in the hypothalamus. E2-treated males showed copulatory behavior represented by mounts and/or intromissions, demonstrating the preservation of aspects of male behavior. They had slightly increased latency for first intromission and a reduced number of ejaculations, associated with a 50% reduction in the fertility index. AR expression in the hypothalamus was assessed by RT-PCR, western blotting, and immunohistochemistry. Treated rats had a significantly lower ventral prostate (VP) weight, demonstrating the efficacy of the treatment. The AR mRNA and protein content in the hypothalamus of E2-treated animals was reduced to the levels of females. AR-expressing cell counts in the ventromedial, anterior medial preoptic, paraventricular nuclei, and preoptic areas were different from control males, and similar to those of females. In conclusion, E2 imprinting resulted not only in ill-developed sexual organs, but also affected sexual behavior, resulting in a female-type hypothalamus, at least with respect to the abundance of AR mRNA and protein and the number of AR-expressing cells in important regions/tracts. Neonatal exposure to high-dose estradiol affects the number of AR+ hypothalamic neurons and male sexual behavior1003737744sem informaçã
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