28 research outputs found
CMB Polarization can constrain cosmology better than CMB temperature
We demonstrate that for a cosmic variance limited experiment, CMB E
polarization alone places stronger constraints on cosmological parameters than
CMB temperature. For example, we show that EE can constrain parameters better
than TT by up to a factor 2.8 when a multipole range of l=30-2500 is
considered. We expose the physical effects at play behind this remarkable
result and study how it depends on the multipole range included in the
analysis. In most relevant cases, TE or EE surpass the TT based cosmological
constraints. This result is important as the small scale astrophysical
foregrounds are expected to have a much reduced impact on polarization, thus
opening the possibility of building cleaner and more stringent constraints of
the LCDM model. This is relevant specially for proposed future CMB satellite
missions, such as CORE or PRISM, that are designed to be cosmic variance
limited in polarization till very large multipoles. We perform the same
analysis for a Planck-like experiment, and conclude that even in this case TE
alone should determine the constraint on better than TT by 15%,
while determining , and with comparable accuracy.
Finally, we explore a few classical extensions of the LCDM model and show again
that CMB polarization alone provides more stringent constraints than CMB
temperature in case of a cosmic variance limited experiment.Comment: 14 pages, 16 figure
BIOÉTICA: O USO DE NÃO-HUMANOS NA VISÃO DE PETER SINGER
Resumo: Nossa pesquisa traz as questões de bioética na visão de Peter Singer, o uso de animais (não humanos) tanto para a questão de alimentação, como na questão de ciência. Nós seres humanos não temos a necessidade de nos alimentarmos de animais, existem outros meios, nosso corpo não necessita de carne, além de que para Peter o uso de animais para fabricação de xampus e cosméticos é pura vaidade, levando em consideração a quantidade absurda que temos no comercio. Para o ele, o uso de animais deveria ter um objetivo muito maior, como por exemplo, usar um rato de laboratório para salvar milhares de pessoas. Isso se dá pelo utilitarismo. Animal sofre e é desnecessário causar sofrimento em prol de algo banal, ou que possa ser suprido de outras formas.Palavras-chave: bioética; animais; Peter Singer; igualdade
Management of Metastatic Endometrial Cancer: Physicians' Choices Beyond the First Line. A MITO Survey
BACKGROUND: Endometrial cancer (EC) therapeutic and diagnostic approaches have been changed by the development of a new prognostic molecular classification, the introduction of dostarlimab in microsatellite instability (MSI) high pre-treated advanced EC patients with further expected innovation deriving from lenvatinib plus pembrolizumab regardless MSI status. How this is and will be translated and embedded in the clinical setting in Italy is not known; this is why we developed Multicentre Italian Trials in Ovarian cancer and gynaecologic malignancies (MITO) survey on the current practice and expected future changes in EC. METHODS: We designed a self-administered, multiple-choice online questionnaire available only for MITO members for one month, starting in April 2021. RESULTS: 75.6% of the respondents were oncologists with a specific focus on gynaecologic malignancies and 73.3% of the respondents declared the availability of clinical trials in second line treatment for advanced EC. The therapeutic algorithm in second line was heterogeneous, being the most frequent choice administering anthracyclines followed by endocrine therapy or enrolling in clinical trials. While more than half of the clinicians declared that they performed the molecular classification, only six/45 respondents (13.3%) ran all the tests needed for it. On the other hand, 80% of them declared regular assessment of MSI status with IHC as recommended. The therapeutic approach in MSI high advanced EC patients has changed since dostarlimab approval. Indeed the most frequent choice in second line has been chemotherapy (53.3%) before its availability, while dostarlimab has been preferred in more than three-fourths of the cases (75.6%) after its approval. As for MSS patients, 77.8% of clinicians would choose lenvatinib plus pembrolizumab for them in second line once approved. CONCLUSIONS: Despite the selected sample of respondents from Italian MITO centres showing good knowledge of diagnostic and therapeutic innovations in EC, these are not fully implemented in everyday clinics, except for MSI status assessment
β-arrestin 2 is required for dopamine receptor type 2 inhibitory effects on AKT phosphorylation and cell proliferation in pituitary tumors.
Dopamine receptor type 2 (DRD2) agonists are the first-choice treatment for PRL-secreting pitui-tary tumors but are poorly effective in non-functioning pituitary neuroendocrine tumors (NF-PitNET). DRD2 reduces AKT phosphorylation in lactotrophs, but no data are available in NF-PitNETs. DRD2 effects on AKT are mediated by a β-arrestin2-dependent mechanism in mouse striatum. The aim of this study was to investigate DRD2 effects on AKT phosphorylation and cell proliferation in human primary cultured NF-PitNET cells and in rat tumoral lactotroph cells MMQ, and to test β-arrestin 2 involvement. We found that DRD2 agonist BIM53097 induced a reduction of p- AKT /total-AKT ratio in MMQ (-32.8±17.6%, p<0.001 vs basal) and in a subset (n=15/41,36.6%) of NF-PitNETs (subgroup 1). In the remaining NF-PitNETs (subgroup 2), BIM53097 induced an increase of p-AKT. The ability of BIM53097 to reduce p-AKT correlated to its antimitotic effect, since the majority of subgroup 1 NF-PitNETs was responsive to BIM53097 and nearly all subgroup 2 NF-PitNETs were resistant. β-arrestin 2 was expressed in MMQ and in 80% of subgroup 1 NF-PitNETs, whereas it was undetectable in 77% of subgroup 2 NF-PitNETs. In MMQ, β-arrestin 2 silencing prevented DRD2 inhibitory effects on p-AKT and cell proliferation. Accordingly, β-arrestin 2 transfection in subgroup 2 NF-PitNETs conferred to BIM53097 the ability to inhibit both p-AKT and cell growth. In conclusion, we demonstrated that β-arrestin 2 is required for DRD2 inhibitory effects on AKT phosphorylation and cell proliferation in MMQ and NF-PitNETs, paving the way for a potential role of β-arrestin 2 as a biomarker predicting NF-PitNETs responsiveness to treatment with dopamine agonists
Octreotide and pasireotide effects on medullary thyroid carcinoma (MTC) cells growth, migration and invasion
Medullary thyroid carcinoma (MTC) is a rare neuroendocrine neoplasm of the parafollicular thyroid C cells.
Although somatostatin receptors are expressed by MTCs, treatment with octreotide has shown poor efficacy,
whereas recently pasireotide has demonstrated antiproliferative effects in persistent postoperative MTCs.
Aim of this study was to test the effects of octreotide and pasireotide on MTC cells proliferation, cell cycle
proteins expression, MAPK activation, apoptosis, calcitonin secretion, migration and invasion in TT cell line as
well as in primary MTC cultured cells. Our results showed that both octreotide and pasireotide reduced TT cell
proliferation (− 35.2 ± 12.1%, p < 0.001, and − 25.3 ± 24.8%, p < 0.05, at 10− 8 M, respectively), with
concomitant inhibition of ERK phosphorylation and cyclin D1 expression. This cytostatic effect was accompanied
by a proapoptotic action, with an increase of caspase3/7 activity of 1.5-fold. Moreover, both octreotide and
pasireotide inhibited cell migration (− 50.9 ± 11.3%, p < 0.01, and − 40.5 ± 17%, p < 0.05, respectively) and
invasion (− 61.3 ± 35.1%, p < 0.05, and − 49.7 ± 18%, p < 0.01, respectively). No effect was observed on
calcitonin secretion. We then tried to extend these observations to primary cultures (n = 5). Octreotide and/or
pasireotide were effective in reducing cells proliferation in 3 out of 5 tumors, and to induce cell apoptosis in 1 out
of 3 MTCs. Both octreotide and pasireotide were able to reduce cell migration in all MTC tested. SST2, SST3 and
SST5 were expressed in all MTC, with a tendency to increased expression of SST2 in RET mutated vs wild type
MTCs. In agreement, inhibition of mutated RET in TT cells reduced SST2 expression.
In conclusion, we demonstrated that octreotide and pasireotide inhibited cell proliferation and invasiveness in
a subset of MTC, supporting their potential use in the control of tumor growth
Cytoskeleton protein Filamin A is required for efficient Somatostatin receptor type 2 internalization and recycling through Rab5 and Rab4 sorting endosomes in tumor somatotroph cells
The high expression of somatostatin receptor 2 (SST2) in growth hormone (GH)-secreting tumors represents the rationale for the clinical use of somatostatin analogs (SSAs) in acromegaly. Recently, the cytoskeletal protein Filamin A (FLNA) has emerged as key modulator of the responsiveness of GH-secreting pituitary tumors to SSAs by regulating SST2 signaling and expression. The aim of this study was to explore FLNA involvement in SST2 intracellular trafficking in tumor somatotroph cells. By biotinylation assay we found that FLNA silencing abolished octreotide-mediated SST2 internalization in rat GH3 cell line (28.0±2.7% vs 4±4.3% SST2 internalization, control vs FLNA siRNA cells, respectively, P<0.001) and human GH-secreting primary cultured cells (70.3±21.1% vs 24±19.2% SST2 internalization, control vs FLNA siRNA cells, respectively, P<0.05). In addition, confocal imaging revealed impaired SST2 recycling to the plasma membrane in FLNA silenced GH3 cells. Co-immunoprecipitation and immunofluorescence experiments showed that FLNA, as well as β-arrestin2, is timely-dependent recruited to octreotide-stimulated SST2 receptors both in rat and human tumor somatotroph cells. Although FLNA expression knock down did not prevent the formation of β-arrestin2-SST2 complex in GH3 cells, it significantly impaired efficient SST2 loading into cytosolic vesicles positive for the early endocytic and recycling markers Rab5 and Rab4, respectively (33.7±8.9% down to 25.9±6.9%, p<0.05, and 28.4±7.4% down to 17.6±5.7%, p<0.01, for SST2-Rab5 and SST2-Rab4 colocalization, respectively, in control vs FLNA siRNA cells). Altogether these data support an important role for FLNA in the mediation of octreotide-induced SST2 trafficking in GH-secreting pituitary tumor cells through Rab5 and Rab4 sorting endosomes
Genetic Profiling of a Cohort of Italian Patients with ACTH-Secreting Pituitary Tumors and Characterization of a Novel USP8 Gene Variant
Cushing’s Disease (CD) is a rare condition characterized by an overproduction of ACTH by an ACTH-secreting pituitary tumor, resulting in an excess of cortisol release by the adrenal glands. Somatic mutations in the deubiquitinases USP8 and USP48, and in BRAF genes, have been reported in a subset of patients affected by CD. The aim of this study was to characterize the genetic profile of a cohort of 60 patients with ACTH-secreting tumors, searching for somatic mutations in USP8, USP48, and BRAF hotspot regions. Seven patients were found to carry USP8 somatic mutations in the well-characterized 14-3-3 protein binding motif (n = 5 P720R, n = 1 P720Q, n = 1 S718del); 2 patients were mutated in USP48 (M415I); no mutation was identified in BRAF. In addition, a novel USP8 variant, G664R, located in exon 14, upstream of the 14-3-3 protein binding motif, was identified in 1 patient. Functional characterization of USP8 G664R variant was performed in murine corticotroph tumor AtT-20 cells. Transient transfection with the USP8 G664R variant resulted in a significant increase of ACTH release and cell proliferation (+114.5 ± 53.6% and +28.3 ± 2.6% vs. empty vector transfected cells, p < 0.05, respectively). Notably, USP8 proteolytic cleavage was enhanced in AtT-20 cells transfected with G664R USP8 (1.86 ± 0.58–fold increase of N-terminal USP8 fragment, vs. WT USP8, p < 0.05). Surprisingly, in situ Proximity Ligation Assay (PLA) experiments showed a significant reduction of PLA positive spots, indicating USP8/14-3-3 proteins colocalization, in G664R USP8 transfected cells with respect to WT USP8 transfected cells (−47.9 ± 6.6%, vs. WT USP8, p < 0.001). No significant difference in terms of ACTH secretion, cell proliferation and USP8 proteolytic cleavage, and 14-3-3 proteins interaction was observed between G664R USP8 and S718del USP8 transfected cells. Immunofluorescence experiments showed that, contrary to S718del USP8 but similarly to WT USP8 and other USP8 mutants, G664R USP8 displays an exclusive cytoplasmic localization. In conclusion, somatic mutations were found in USP8 (13.3% vs. 36.5% incidence of all published mutations) and USP48 (3.3% vs. 13.3% incidence) hotspot regions. A novel USP8 variant was identified in a CD patient, and in vitro functional studies in AtT-20 cells suggested that this somatic variant might be clinically relevant in ACTH-secreting tumor pathogenesis, expanding the characterization of USP8 functional domains
Potential role of raltegravir-based therapy to induce rapid viral decay in highly viraemic HIV-infected neonates
We report safety and tolerability of raltegravir (RAL) as a forth HIV agent in two highly viraemic newborns. Raltegravir (6 mg/kg) was given orally twice daily. The other antiretrovirals were assumed according to standard dose for newborns. The first baby was born at week 36. An antiretroviral therapy consisting of zidovudine, lamivudine, and lopinavir/ritonavir was started 96 hour after delivery. Raltegravir was added at hour 120, being plasma HIV-1 RNA above 10\uc3\u97106 copies/ml. HIV RNA declined to 5\uc2\ub7000 copies/ml at day 30. The second baby was born at week 40. He was started on zidovudine, lamivudine, and nevirapine at day 0, while RAL was added at day 3. Plasma HIV-1 RNA declined from 6\uc2\ub76\uc3\u97106 at birth to 52 copies/ml at day 28. RAL tolerability was good in both patients, one with gamma-glutamyltransferase increase, which normalized after RAL discontinuation. Raltegravir-based four drug regimen may be effective and well tolerated in highly viraemic HIV neonates up to 4 weeks