18 research outputs found
Distinct Cerebellar regions for Body Motion Discrimination.
Abstract
Visual processing of human movements is critical for adaptive social behavior. Cerebellar activations have been observed during biological motion discrimination in prior neuroimaging studies, and cerebellar lesions may be detrimental for this task. However, whether the cerebellum plays a causal role in biological motion discrimination has never been tested. Here, we addressed this issue in three different experiments by interfering with the posterior cerebellar lobe using transcranial magnetic stimulation (TMS) during a biological discrimination task. In Experiments 1 and 2, we found that TMS delivered at onset of the visual stimuli over the vermis (vermal lobule VI), but not over the left cerebellar hemisphere (left lobule VI/Crus I), interfered with participants' ability to distinguish biological from scrambled motion compared to stimulation of a control site (vertex). Interestingly, when stimulation was delivered at a later time point (300 ms after stimulus onset), participants performed worse when TMS was delivered over the left cerebellar hemisphere compared to the vermis and the vertex (Experiment 3). Our data show that the posterior cerebellum is causally involved in biological motion discrimination and suggest that different sectors of the posterior cerebellar lobe may contribute to the task at different time points
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Sublethal concentrations of 17-AAG suppress homologous recombination DNA repair and enhance sensitivity to carboplatin and olaparib in HR proficient ovarian cancer cells
The promise of PARP-inhibitors(PARPis) in the management of epithelial ovarian cancer(EOC) is tempered by the fact that approximately 50% of patients with homologous recombination (HR)-proficient tumors do not respond well to these agents. Combination of PARPis with agents that inhibit HR may represent an effective strategy to enhance their activity in HR-proficient tumors. Using a bioinformatics approach, we identified that heat shock protein 90 inhibitors(HSP90i) may suppress HR and thus revert HR-proficient to HR-deficient tumors. Analysis of publicly available gene expression data showed that exposure of HR-proficient breast cancer cell lines to HSP90i 17-AAG(17-allylamino-17-demethoxygeldanamycin) downregulated HR, ATM and Fanconi Anemia pathways. In HR-proficient EOC cells, 17-AAG suppressed HR as assessed using the RAD51 foci formation assay and this was further confirmed using the Direct Repeat-GFP reporter assay. Furthermore, 17-AAG downregulated BRCA1 and/or RAD51 protein levels, and induced significantly more γH2AX activation in combination with olaparib compared to olaparib alone. Finally, sublethal concentrations of 17-AAG sensitized HR-proficient EOC lines to olaparib and carboplatin but did not affect sensitivity of the HR-deficient OVCAR8 line arguing that the 17-AAG mediated sensitization is dependent on suppression of HR. These results provide a preclinical rationale for using a combination of olaparib/17-AAG in HR-proficient EOC
First line avelumab in PD-L1+ve metastatic or locally advanced urothelial cancer (aUC) patients unfit for cisplatin (cis): The ARIES trial
Background:
Avelumab (ave) was approved as maintenance therapy after platinum-based first line (1L) therapy for patients (pts) with aUC based on ph. 3 Javelin Bladder 100 study (NCT02603432), showing significant overall survival (OS) improvement. Here we tested the activity of ave as 1L of therapy in cis-unfit pts with aUC and PD-L1+ve expression.
Methods:
ARIES is a single-arm, multi-site, open-label phase II trial. Enrolled pts had aUC, were cis-unfit (at least one of: ECOG-PS = 2, CrCl < 60 mL/min, grade ≥2 peripheral neuropathy/hearing loss, progression within 6-mos before the end of neo/adj chemo), had not previously received chemo for aUC and PD-L1≥5% (SP263) centrally assessed. Pts received ave 10 mg/Kg IV Q2W until progression, unacceptable toxicity and withdrawal, whichever occurred first. The primary endpoint was the 1-year OS. Key secondary endpoints were median-OS, -PFS, ORR and safety.
Results:
A total of 198 eligible cis-unfit pts have been tested for PD-L1 and 71 (35.6%) have been found positive. Among enrolled patients (N = 71), median age was 75 y, 35 (49.3%) had visceral disease, and 22 (31.0%) had ECOG-PS = 2; 50 (70.4%) had CrCl < 60 mL/min and 9 (12.7%) progressed within 6-mos from the end of neo/adj chemo. At the cut-off data (Oct 7, 2021), median follow up was 9.0 mo and 13 patients are still on treatment. The median OS was 10.0 mos (95% CI, 5.7-14.3), and 40.8% of patients were alive at 1-year. The ORR for all patients was 22.5%; complete response, 1.4% (n = 1); partial response, 21.1% (n = 15). Clinical benefit was 43.6% (n = 31). Median PFS was 2.0 mos (95% CI, 1.4-2.6). Among the 56 pts who received at least 3 cycles (29 days) of therapy the median OS was 16.0 vs 1.0 mos. Five (7.0%) grade 3 ave-related adverse events, and no treatment-related death were reported.
Conclusions:
Ave is active and safe in pts with cis-unfit, PD-L1+ve aUC and poor baseline characteristics
Response to gefitinib and erlotinib in Non-small cell lung cancer: a retrospective study
<p>Abstract</p> <p>Background</p> <p>In Non-small cell lung cancer (NSCLC), an overactive epidermal growth factor receptor (EGFR) pathway is a component of the malignant phenotype. Two tyrosine kinase inhibitors (TKIs) of EGFR, gefinitib and erlotinib, have been used with variable benefit.</p> <p>Methods</p> <p>We have analyzed outcome data of a population of NSCLC patients that received these TKIs to determine the benefit derived and to define the clinical and molecular parameters that correlate with response. Tumor tissue from a subgroup of these patients was analyzed by immunohistochemistry to measure the expression level of EGFR and four activated (phosphorylated) members of the pathway, pEGFR, pERK, pAKT, and pSTAT3.</p> <p>Results</p> <p>Erlotinib was slightly superior to gefitinib in all measures of response, although the differences were not statistically significant. The most robust clinical predictors of time to progression (TTP) were best response and rash (p < 0.0001). A higher level of pEGFR was associated with longer TTP, while the total EGFR level was not associated with response. Higher levels of pAKT and pSTAT3 were also associated with longer TTP. In contrast, a higher level of pERK1/2 was associated with shorter TTP.</p> <p>Conclusion</p> <p>These observations suggest the hypothesis that tumor cells that have activated EGFR pathways, presumably being utilized for survival, are clinically relevant targets for pathway inhibition. An accurate molecular predictive model of TKI response should include activated members of the EGFR pathway. TKIs may be best reserved for tumors expressing pEGFR and pAKT or pSTAT, and little pERK. In the absence of molecular predictors of response, the appearance of a rash and a positive first scan are good clinical indicators of response.</p
Limiting the propagation of localization errors in multi-hop wireless networks
This paper concerns a study of the process of localizing the nodes of a multi-hop wireless networks, i.e., of having the node computing their coordinates with respect to a suitable reference system. We consider networks where the nodes perform measurements of distance and angle of arrival from nodes within their transmission radius. We describe a simple localization protocol, termed Range-Based Centroid (RBC), that starting from a single node (the beacon) with given coordinates localizes all the network nodes with reasonable accuracy. We then propose a new localization protocol that achieves greater accuracy by containing the propagation of the localization error as the process progresses away from the beacon. We quantify the improvements of the proposed protocol, termed MEC 2 (for Minimum Enclosing Circle Containment) by simulations. In the considered scenarios, MEC 2 keeps the localization error within 21% of the nodes' transmission radius, with 20-30% improvements over RBC. © 2006 IEEE
NRAGE Mediates p38 Activation and Neural Progenitor Apoptosis via the Bone Morphogenetic Protein Signaling Cascade
Understanding the molecular events that govern neural progenitor lineage commitment, mitotic arrest, and differentiation into functional progeny are germane to our understanding of neocortical development. Members of the family of bone morphogenetic proteins (BMPs) play pivotal roles in regulating neural differentiation and apoptosis during neurogenesis through combined actions involving Smad and TAK1 activation. We demonstrate that BMP signaling is required for the induction of apoptosis of neural progenitors and that NRAGE is a mandatory component of the signaling cascade. NRAGE possesses the ability to bind and function with the TAK1-TAB1-XIAP complex facilitating the activation of p38. Disruption of NRAGE or any other member of the noncanonical signaling cascaded is sufficient to block p38 activation and thus the proapoptotic signals generated through BMP exposure. The function of NRAGE is independent of Smad signaling, but the introduction of a dominant-negative Smad5 also rescues neural progenitor apoptosis, suggesting that both canonical and noncanonical pathways can converge and regulate BMP-mediated apoptosis. Collectively, these results establish NRAGE as an integral component in BMP signaling and clarify its role during neural progenitor development
Expression and function of ABCG2 and XIAP in glioblastomas.
Despite multimodal treatment that includes surgery, radiation and chemotherapy, virtually all glioblastomas (GBM) recur, indicating that these interventions are insufficient to eradicate all malignant cells. To identify potential new therapeutic targets in GBMs, we examined the expression and function of proteins that are associated with therapy resistance and cancer cell survival. We measured the expression of eight such proteins in 50 GBM samples by immunohistochemistry and analyzed patient survival. We report that GBM patients with high expression of ABCG2 (also called BCRP) or XIAP at the protein level had worse survival than those with low expression. The adjusted hazard ratio for ABCG2 was 2.35 and for XIAP was 2.65. Since glioma stem cells (GSCs) have been shown to be more resistant than bulk tumor cells to anti-cancer therapies and to express high levels of these proteins, we also sought to determine if ABCG2 and XIAP have functional roles in GSCs. We used small molecule inhibitors to treat patient-derived GBM tumorspheres in vitro and observed that inhibitors of ABCG2, Ko143 and fumitremorgin, significantly reduced self-renewal. These results suggest that ABCG2 and XIAP proteins may be useful indicators of patient survival and that inhibition of ABCG2 may be a promising therapeutic strategy in GBMs. J Neurooncol 2017 May; 133(1):47-57
Expression and function of ABCG2 and XIAP in glioblastomas.
Despite multimodal treatment that includes surgery, radiation and chemotherapy, virtually all glioblastomas (GBM) recur, indicating that these interventions are insufficient to eradicate all malignant cells. To identify potential new therapeutic targets in GBMs, we examined the expression and function of proteins that are associated with therapy resistance and cancer cell survival. We measured the expression of eight such proteins in 50 GBM samples by immunohistochemistry and analyzed patient survival. We report that GBM patients with high expression of ABCG2 (also called BCRP) or XIAP at the protein level had worse survival than those with low expression. The adjusted hazard ratio for ABCG2 was 2.35 and for XIAP was 2.65. Since glioma stem cells (GSCs) have been shown to be more resistant than bulk tumor cells to anti-cancer therapies and to express high levels of these proteins, we also sought to determine if ABCG2 and XIAP have functional roles in GSCs. We used small molecule inhibitors to treat patient-derived GBM tumorspheres in vitro and observed that inhibitors of ABCG2, Ko143 and fumitremorgin, significantly reduced self-renewal. These results suggest that ABCG2 and XIAP proteins may be useful indicators of patient survival and that inhibition of ABCG2 may be a promising therapeutic strategy in GBMs