Mifepristone prevents repopulation of ovarian cancer cells escaping cisplatin-paclitaxel therapy

<p>Abstract</p> <p>Background</p> <p>Advanced ovarian cancer is treated with cytoreductive surgery and combination platinum- and taxane-based chemotherapy. Although most patients have acute clinical response to this strategy, the disease ultimately recurs. In this work we questioned whether the synthetic steroid mifepristone, which as monotherapy inhibits the growth of ovarian cancer cells, is capable of preventing repopulation of ovarian cancer cells if given after a round of lethal cisplatin-paclitaxel combination treatment.</p> <p>Methods</p> <p>We established an <it>in vitro</it> approach wherein ovarian cancer cells with various sensitivities to cisplatin or paclitaxel were exposed to a round of lethal doses of cisplatin for 1 h plus paclitaxel for 3 h. Thereafter, cells were maintained in media with or without mifepristone, and short- and long-term cytotoxicity was assessed.</p> <p>Results</p> <p>Four days after treatment the lethality of cisplatin-paclitaxel was evidenced by reduced number of cells, increased hypodiploid DNA content, morphological features of apoptosis, DNA fragmentation, and cleavage of caspase-3, and of its downstream substrate PARP. Short-term presence of mifepristone either enhanced or did not modify such acute lethality. Seven days after receiving cisplatin-paclitaxel, cultures showed signs of relapse with escaping colonies that repopulated the plate in a time-dependent manner. Conversely, cultures exposed to cisplatin-paclitaxel followed by mifepristone not only did not display signs of repopulation following initial chemotherapy, but they also had their clonogenic capacity drastically reduced when compared to cells repopulating after cisplatin-paclitaxel.</p> <p>Conclusions</p> <p>Cytostatic concentrations of mifepristone after exposure to lethal doses of cisplatin and paclitaxel in combination blocks repopulation of remnant cells surviving and escaping the cytotoxic drugs.</p

Systemic therapy of Cushing’s syndrome

Cushing’s disease (CD) in a stricter sense derives from pathologic adrenocorticotropic hormone (ACTH) secretion usually triggered by micro- or macroadenoma of the pituitary gland. It is, thus, a form of secondary hypercortisolism. In contrast, Cushing’s syndrome (CS) describes the complexity of clinical consequences triggered by excessive cortisol blood levels over extended periods of time irrespective of their origin. CS is a rare disease according to the European orphan regulation affecting not more than 5/10,000 persons in Europe. CD most commonly affects adults aged 20–50 years with a marked female preponderance (1:5 ratio of male vs. female). Patient presentation and clinical symptoms substantially vary depending on duration and plasma levels of cortisol. In 80% of cases CS is ACTH-dependent and in 20% of cases it is ACTH-independent, respectively. Endogenous CS usually is a result of a pituitary tumor. Clinical manifestation of CS, apart from corticotropin-releasing hormone (CRH-), ACTH-, and cortisol-producing (malign and benign) tumors may also be by exogenous glucocorticoid intake. Diagnosis of hypercortisolism (irrespective of its origin) comprises the following: Complete blood count including serum electrolytes, blood sugar etc., urinary free cortisol (UFC) from 24 h-urine sampling and circadian profile of plasma cortisol, plasma ACTH, dehydroepiandrosterone, testosterone itself, and urine steroid profile, Low-Dose-Dexamethasone-Test, High-Dose-Dexamethasone-Test, after endocrine diagnostic tests: magnetic resonance imaging (MRI), ultra-sound, computer tomography (CT) and other localization diagnostics. First-line therapy is trans-sphenoidal surgery (TSS) of the pituitary adenoma (in case of ACTH-producing tumors). In patients not amenable for surgery radiotherapy remains an option. Pharmacological therapy applies when these two options are not amenable or refused. In cases when pharmacological therapy becomes necessary, Pasireotide should be used in first-line in CD. CS patients are at an overall 4-fold higher mortality rate than age- and gender-matched subjects in the general population. The following article describes the most prominent substances used for clinical management of CS and gives a systematic overview of safety profiles, pharmacokinetic (PK)-parameters, and regulatory framework

Avaliação do Metabolismo Nutricional em Poedeiras pela Técnica dos Isótopos Estáveis do Ccarbono (13C/12C) Nutritional Metabolism Evaluation of Laying Hens Using Stable-Carbon Isotopes (13C/12C)

Os isótopos estáveis do carbono que eram utilizados em estudos ecológicos e paleoecológicos apresentaram um incremento nos últimos trinta anos, na utilização em estudos dietéticos em animais. Entretanto, existem poucas informações sobre o padrão metabólico e sobre as taxas de turnover do 13C em aves. O presente experimento estabeleceu curvas de substituição e taxas de movimentação do 13C no ovo e no fígado de aves de postura adultas, pela substituição da ração comercial por dietas compostas de grãos dos ciclos fotossintéticos C3 e C4, durante 50 dias. A diferença no conteúdo isotópico do delta per mil do carbono-13 (delta‰ 13C) entre as duas dietas foi de 16,13‰. A taxa de substituição do 13C das dietas, nos tecidos, adequou-se num modelo exponencial, descrevendo o turnover do carbono nos tecidos analisados. As taxas de movimentação do 13C, nas aves alimentadas com dieta baseada em grãos C3, foi maior no fígado em relação ao ovo, com valores para a meia-vida de 2,9 e 3,7 dias, respectivamente. As aves que receberam ração com grãos C4 apresentaram uma taxa de turnover no ovo superior àquela obtida para o fígado, com meia-vida de 4,0 e 5,3 dias, respectivamente. Os valores do delta‰13C observados para ovo e fígado diferiram em aproximadamente 2‰ daqueles referentes às dietas.<br>The stable carbon isotopes used in ecology and paleoecology during the last 30 years has now been used in dietary studies of animals. However, there are not enough studies on the metabolism patterns and turnover rates of the 13C in avian. This experiment established the turnover rates of the 13C in egg and liver tissues of adult laying hens through the substitution of commercial diets by diets containing C3 and C4 photosynthetic cycle grains for 50 days. The delta‰13C difference in two diets contents was 16.13‰. The diets 13C turnover rates in tissues were adapted in an exponential model that describes the isotopic carbon turnover in those tissues. Avian turnover rates of 13C fed with diet based on grains C3 were larger in liver than egg with half-life of 2.9 and 3.7 days. Avian fed with diet based on grains C4 showed turnover rates larger in egg than liver, with half-life of 4.0 to 5.3 days respectively. The delta‰13C values reached in egg and liver differed of the diet in approximately 2‰

The traceability of animal meals in layer diets as detected by stable carbon and nitrogen isotope analyses of eggs

The aim of this study was to trace the inclusion of animal meals in layer diets by analyzing eggs and their fractions (yolk and albumen) using the technique of carbon and nitrogen isotopes. Two-hundred and eighty-eight (288) 73-week-old Shaver White layers, never fed animal ingredients, were randomly distributed in six treatments with six replicates each. The treatments were: control - corn and soybean meal based diet and five other experimental diets including bovine meat and bone meal (MBM); poultry offal meal (POM); feather meal (FM); feather meal and poultry offal meal (OFM), and poultry offal meal, feather meal, and meat and bone meal (MBOFM). The isotopic results were submitted to multivariate analysis of variance. Ellipses were determined through an error matrix (95% confidence) to identify differences between treatments and the control group. In the albumen and yolk of all experimental treatments were significantly different from the control diet (p < 0.05). In summary, the stable isotope technique is able to trace the animal meals included in layer feeds in the final product under these experimental conditions

Progesterone Inhibits the Growth of Human Neuroblastoma: In Vitro and In Vivo Evidence

We investigated the antitumorogenic effects of progesterone (P4) in a human neuroblastoma (SK-N-AS) cell line in vitro and in a mouse xenograft model of neuroblastoma. The safety of P4 was tested in rat primary cortical neurons and human foreskin fibroblasts (HFF-1). At high doses, P4 significantly (P < 0.05) decreased SK-N-AS cell viability in vitro, and this effect was not blocked either by 5α-reductase inhibitor, finasteride or the P4 receptor antagonist RU486. Even at very high doses, P4 did not induce any cell death in healthy primary cortical neurons or HFF-1. The bioavailability of P4 24 h after the last injection in the serum of treated animals was significantly (P < 0.05) higher (10–33 μg/mL) than in untreated animals. In nude mice, P4 (50 and 100 mg/kg) inhibited neuroblastoma growth by ~50% over 8 d of treatment. No drug toxicity was observed in the mice, as measured by body weight and activity. P4 suppressed the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-9, MMP-2), which are involved in tumor vascular development. High-dose P4 inhibited tumor growth by suppressing cell proliferation and inducing apoptosis, as evidenced by the expression of proliferating cell nuclear antigen and cleaved caspase-3. P4 significantly increased the expression of P4 receptor isoform-A and suppressed phospho-Akt (Ser437) expression. In conclusion, at high doses, P4 effectively inhibits the growth of solid neuroblastoma tumor and has high bioavailability, selective toxicity and a high margin of safety, making it a possible candidate for further study as a potential clinical treatment of neuroblastoma