The cell of origin dictates the temporal course of neurofibromatosis-1 (Nf1) low-grade glioma formation.

Low-grade gliomas are one of the most common brain tumors in children, where they frequently form within the optic pathway (optic pathway gliomas; OPGs). Since many OPGs occur in the context of the Neurofibromatosis Type 1 (NF1) cancer predisposition syndrome, we have previously employed Nf1 genetically-engineered mouse (GEM) strains to study the pathogenesis of these low-grade glial neoplasms. In the light of the finding that human and mouse low-grade gliomas are composed of Olig2+ cells and that Olig2+ oligodendrocyte precursor cells (OPCs) give rise to murine high-grade gliomas, we sought to determine whether Olig2+ OPCs could be tumor-initiating cells for Nf1 optic glioma. Similar to the GFAP-Cre transgenic strain previously employed to generate Nf1 optic gliomas, Olig2+ cells also give rise to astrocytes in the murine optic nerve in vivo. However, in contrast to the GFAP-Cre strain where somatic Nf1 inactivation in embryonic neural progenitor/stem cells (Nf1flox/mut; GFAP-Cre mice) results in optic gliomas by 3 months of age in vivo, mice with Nf1 gene inactivation in Olig2+ OPCs (Nf1flox/mut; Olig2-Cre mice) do not form optic gliomas until 6 months of age. These distinct patterns of glioma latency do not reflect differences in the timing or brain location of somatic Nf1 loss. Instead, they most likely reflect the cell of origin, as somatic Nf1 loss in CD133+ neural progenitor/stem cells during late embryogenesis results in optic gliomas at 3 months of age. Collectively, these data demonstrate that the cell of origin dictates the time to tumorigenesis in murine optic glioma

Senior Recital: Nathaniel J. Parson, Horn; Daniel G. Castillon III, Horn; Grace Eom, Piano; Valen Pao, Piano; November 13, 2022

Kemp Recital HallNovember 13, 2022Sunday Evening5:30 p.m

LIBRETTO-531: a phase III study of selpercatinib in multikinase inhibitor-naïve RET-mutant medullary thyroid cancer

Medullary thyroid cancer; Selpercatinib; Targeted therapyCáncer medular de tiroides; Selpercatinib; Terapia dirigidaCàncer medul·lar de tiroide; Selpercatinib; Teràpia dirigidaSelpercatinib is a first-in-class, highly selective and potent, central nervous system-active RET kinase inhibitor. In the phase I/II trial, selpercatinib demonstrated clinically meaningful antitumor activity with manageable toxicity in heavily pre-treated and treatment-naive patients with RET-mutant medullary thyroid cancer (MTC). LIBRETTO-531 (NCT04211337) is a multicenter, open-label, randomized, controlled, phase III trial comparing selpercatinib to cabozantinib or vandetanib in patients with advanced/metastatic RET-mutant MTC. The primary objective is to compare progression-free survival (per RECIST 1.1) by blinded independent central review of patients with progressive, advanced, multikinase inhibitor-naive, RET-mutant MTC treated with selpercatinib versus cabozantinib or vandetanib. Key secondary objectives are to compare other efficacy outcomes (per RECIST 1.1) and tolerability of selpercatinib versus cabozantinib or vandetanib

Rationale of the association between Mediterranean diet and the risk of frailty in older adults and systematic review and meta-analysis

Frailty is a geriatric syndrome whose frequency is increasing in parallel with population aging and is of great interest due to its dire consequences: increased disability, hospitalizations, falls and fractures, institutionalization, and mortality. Frailty is multifactorial but nutritional factors, which are modifiable, play a crucial role in its pathogenesis. Epidemiologic evidence supports that high-quality dietary patterns can prevent, delay or even reverse the occurrence of frailty. In order to add new knowledge bridging the gap as the main purpose of the present article we performed a comprehensive review of the rationale behind the association of MedDiet with frailty and a systematic review and meta-analysis updating the latest ones published in 2018 specifically examining the relationship of Mediterranean diet (MedDiet) and incident frailty. Adding the updated information, our results confirmed a robust association of a higher adherence to MedDiet with reduced incident frailty. Key components of the MedDiet, i.e., abundant consumption of vegetables and fruit as well as the use of olive oil as the main source of fat, all of which have been associated with a lower incidence of frailty, may help explain the observed benefit. Future well-designed and sufficiently large intervention studies are needed to confirm the encouraging findings of the current observational evidence. Meanwhile, based on the existing evidence, the promotion of MedDiet, a high-quality dietary pattern, adapted to the conditions and traditions of each region, and considering lifelong and person-tailored strategies, is an open opportunity to reduced incident frailty. This could also help counteract the worrying trend towards the spread of unhealthy eating and lifestyle models such as those of Western diets that greatly contribute to the genesis of chronic non-communicable diseases and disability

Effectiveness of brentuximab vedotin monotherapy in relapsed or refractory Hodgkin lymphoma:a systematic review and meta-analysis

This systematic review and meta-analysis aimed to determine the effectiveness of brentuximab vedotin (BV) in relapsed/refractory classical Hodgkin lymphoma (R/R cHL) in the clinical practice setting using most recent results. A total of 32 observational studies reporting on treatment patterns, overall response rate (ORR), complete response (CR) rate, progression-free survival (PFS), overall survival (OS), and adverse events were found. After four cycles, a random-effect model yielded pooled ORR and CR rates of 62.6% (95% confidence interval (CI): 56.0-68.9; I-2 = 9.7%) and 32.9% (95% CI, 20.8-46.3, I-2 = 64.8%), respectively. Regarding survival, 1-year, 2-year, and 5-year PFS ranged from 52.1% to 63.2%, 45.2% to 56.2%, and 31.9% to 33.0%, respectively. OS rates were 68.2-82.7%, 58.0-81.9%, and 58.0-62.0%, respectively. Most common adverse events were hematological toxicities (neutropenia: 13.3-23%, anemia: 8.8-39.0%, and thrombocytopenia: 4-4.6%), and grade >= 3 peripheral neuropathy (3.3-7.3%). This study supports the effectiveness and safety of BV in R/R cHL patients in the real-world setting

Management of incidentally discovered appendiceal neuroendocrine tumors after an appendicectomy

Appendiceal neoplasms; Carcinoid tumor; Treatment outcomeNeoplasias apendiculares; Tumor carcinoide; Resultado del tratamientoNeoplàsies apendiculars; Tumor carcinoide; Resultat del tractamentAppendiceal neuroendocrine tumors (aNETs) are an uncommon neoplasm that is relatively indolent in most cases. They are typically diagnosed in younger patients than other neuroendocrine tumors and are often an incidental finding after an appendectomy. Although there are numerous clinical practice guidelines on management of aNETs, there is continues to be a dearth of evidence on optimal treatment. Management of these tumors is stratified according to risk of locoregional and distant metastasis. However, there is a lack of consensus regarding tumors that measure 1-2 cm. In these cases, some histopathological features such as size, tumor grade, presence of lymphovascular invasion, or mesoappendix infiltration must also be considered. Computed tomography or magnetic resonance imaging scans are recommended for evaluating the presence of additional disease, except in the case of tumors smaller than 1 cm without additional risk factors. Somatostatin receptor scintigraphy or positron emission tomography with computed tomography should be considered in cases with suspected residual or distant disease. The main point of controversy is the indication for performing a completion right hemicolectomy after an initial appendectomy, based on the risk of lymph node metastases. The main factor considered is tumor size and 2 cm is the most common threshold for indicating a colectomy. Other factors such as mesoappendix infiltration, lymphovascular invasion, or tumor grade may also be considered. On the other hand, potential complications, and decreased quality of life after a hemicolectomy as well as the lack of evidence on benefits in terms of survival must be taken into consideration. In this review, we present data regarding the current indications, outcomes, and benefits of a colectomy

The yeast P5 type ATPase, Spf1, regulates manganese transport into the endoplasmic reticulum

The endoplasmic reticulum (ER) is a large, multifunctional and essential organelle. Despite intense research, the function of more than a third of ER proteins remains unknown even in the well-studied model organism Saccharomyces cerevisiae. One such protein is Spf1, which is a highly conserved, ER localized, putative P-type ATPase. Deletion of SPF1 causes a wide variety of phenotypes including severe ER stress suggesting that this protein is essential for the normal function of the ER. The closest homologue of Spf1 is the vacuolar P-type ATPase Ypk9 that influences Mn2+ homeostasis. However in vitro reconstitution assays with Spf1 have not yielded insight into its transport specificity. Here we took an in vivo approach to detect the direct and indirect effects of deleting SPF1. We found a specific reduction in the luminal concentration of Mn2+ in ∆spf1 cells and an increase following it’s overexpression. In agreement with the observed loss of luminal Mn2+ we could observe concurrent reduction in many Mn2+-related process in the ER lumen. Conversely, cytosolic Mn2+-dependent processes were increased. Together, these data support a role for Spf1p in Mn2+ transport in the cell. We also demonstrate that the human sequence homologue, ATP13A1, is a functionally conserved orthologue. Since ATP13A1 is highly expressed in developing neuronal tissues and in the brain, this should help in the study of Mn2+-dependent neurological disorders

Bronchial epithelial spheroids: an alternative culture model to investigate epithelium inflammation-mediated COPD

<p>Abstract</p> <p>Background</p> <p>Chronic obstructive pulmonary disease (COPD) is characterized by abnormal lung inflammation that exceeds the protective response. Various culture models using epithelial cell lines or primary cells have been used to investigate the contribution of bronchial epithelium in the exaggerated inflammation of COPD. However, these models do not mimic <it>in vivo </it>situations for several reasons (e.g, transformed epithelial cells, protease-mediated dissociation of primary cells, etc.). To circumvent these concerns, we developed a new epithelial cell culture model.</p> <p>Methods</p> <p>Using non transformed non dissociated bronchial epithelium obtained by bronchial brushings from COPD and non-COPD smokers, we developed a 3-dimensional culture model, bronchial epithelial spheroids (BES). BES were analyzed by videomicroscopy, light microscopy, immunofluorescence, and transmission electron microscopy. We also compared the inflammatory responses of COPD and non-COPD BES. In our study, we chose to stimulate BES with lipopolycaccharide (LPS) and measured the release of the pro-inflammatory mediators interleukin-8 (IL-8) and leukotriene B4 (LTB4) and the anti-inflammatory mediator prostaglandin E2 (PGE2).</p> <p>Results</p> <p>BES obtained from both COPD and non-COPD patients were characterized by a polarized bronchial epithelium with tight junctions and ciliary beating, composed of basal cells, secretory cells and ciliated cells. The ciliary beat frequency of ciliated cells was not significantly different between the two groups. Of interest, BES retained their characteristic features in culture up to 8 days. BES released the inflammatory mediators IL-8, PGE2 and LTB4 constitutively and following exposure to LPS. Interestingly, LPS induced a higher release of IL-8, but not PGE2 and LTB4 in COPD BES (p < 0.001) which correlated with lung function changes.</p> <p>Conclusion</p> <p>This study provides for the first time a compelling evidence that the BES model provides an unaltered bronchial surface epithelium. More importantly, BES represent an attractive culture model to investigate the mechanisms of injuring agents that mediate epithelial cell inflammation and its contribution to COPD pathogenesis.</p

A Novel Role for the GTPase-Activating Protein Bud2 in the Spindle Position Checkpoint

The spindle position checkpoint (SPC) ensures correct mitotic spindle position before allowing mitotic exit in the budding yeast Saccharomyces cerevisiae. In a candidate screen for checkpoint genes, we identified bud2Δ as deficient for the SPC. Bud2 is a GTPase activating protein (GAP), and the only known substrate of Bud2 was Rsr1/Bud1, a Ras-like GTPase and a central component of the bud-site-selection pathway. Mutants lacking Rsr1/Bud1 had no checkpoint defect, as did strains lacking and overexpressing Bud5, a guanine-nucleotide exchange factor (GEF) for Rsr1/Bud1. Thus, the checkpoint function of Bud2 is distinct from its role in bud site selection. The catalytic activity of the Bud2 GAP domain was required for the checkpoint, based on the failure of the known catalytic point mutant Bud2R682A to function in the checkpoint. Based on assays of heterozygous diploids, bud2R682A, was dominant for loss of checkpoint but recessive for bud-site-selection failure, further indicating a separation of function. Tem1 is a Ras-like protein and is the critical regulator of mitotic exit, sitting atop the mitotic exit network (MEN). Tem1 is a likely target for Bud2, supported by genetic analyses that exclude other Ras-like proteins