Extracellular vesicles in anti-tumor immunity

To what extent extracellular vesicles (EVs) can impact anti-tumor immune responses has only started to get unraveled. Their nanometer dimensions, their growing number of subtypes together with the difficulties in defining their origin hampers their investigation. The existence of tumor cell lines facilitated advance in cancer EV understanding, while capturing information about phenotypes and functions of immune cell EVs in this context is more complex. The advent of immunotherapy with immune checkpoint inhibitors has further deepened the need to dissect the impact of EVs during immune activation and response, not least to contribute unraveling and preventing the generation of resistance occurring in the majority of patients. Here we discuss the factors that influence/drive the immune response in cancer patients in the context of cancer therapeutics and the roles or possible functions EVs can have in this scenario. With immune cell-derived EVs as leitmotiv we will journey from EV discovery and subtypes through their physiological and pathological non-cancer functions to their similarities with cancer EVs and on how to revert their detrimental consequences on immune responses to cancer

Cortical Inhibitory Imbalance in functional paralysis

Background: Functional neurological disorders are characterized by neurological symptoms that have no identifiable pathology and little is known about their underlying pathophysiology. Objectives: To analyze motor cortex excitability and intracortical inhibitory and excitatory circuits' imbalance in patients with flaccid functional weakness. Methods: Twenty-one consecutive patients with acute onset of flaccid functional weakness were recruited. Single and paired-pulse transcranial magnetic stimulation (TMS) protocols were used to analyze resting motor thresholds (RMT) and intracortical inhibitory (short interval intracortical inhibition - SICI) and excitatory (intracortical facilitation - ICF) circuits' imbalance between the affected and non-affected motor cortices. Results: We observed a significant increase in RMT and SICI in the affected motor cortex (p < 0.001), but not for ICF, compared to the contralateral unaffected side. Conclusion: This study extends current knowledge of functional weakness, arguing for a specific central nervous system abnormality which may be involved in the symptoms' pathophysiology

3D tumor explant as a novel platform to investigate therapeutic pathways and predictive biomarkers in cancer patients

Immunotherapy with immune checkpoint inhibitors can induce durable clinical responses in different human malignancies but the number of responding patients remains globally modest. The limited therapeutic efficacy of ICI depends on multiple factors, among which the immune suppressive features of the tumor microenvironment play a key role. For this reason, experimental models that enable dissection of the immune-hostile tumor milieu components are required to unravel how to overcome resistance and obtain full-fledged anti-tumor immunity. Recent evidence supports the usefulness of 3D ex vivo systems in retaining features of tumor microenvironment to elucidate molecular and immunologic mechanisms of response and resistance to immune checkpoint blockade. In this perspective article we discuss the recent advances in patient-derived 3D tumor models and their potential in support of treatment decision making in clinical setting. We will also share our experience with dynamic bioreactor tumor explant culture of samples from melanoma and sarcoma patients as a reliable and promising platform to unravel immune responses to immune checkpoint inhibitors

miR-146a-5p impairs melanoma resistance to kinase inhibitors by targeting COX2 and regulating NFkB-mediated inflammatory mediators

BACKGROUND: Targeted therapy with BRAF and MEK inhibitors has improved the survival of patients with BRAF-mutated metastatic melanoma, but most patients relapse upon the onset of drug resistance induced by mechanisms including genetic and epigenetic events. Among the epigenetic alterations, microRNA perturbation is associated with the development of kinase inhibitor resistance. Here, we identified and studied the role of miR-146a-5p dysregulation in melanoma drug resistance.METHODS: The miR-146a-5p-regulated NFkB signaling network was identified in drug-resistant cell lines and melanoma tumor samples by expression profiling and knock-in and knock-out studies. A bioinformatic data analysis identified COX2 as a central gene regulated by miR-146a-5p and NFkB. The effects of miR-146a-5p/COX2 manipulation were studied in vitro in cell lines and with 3D cultures of treatment-resistant tumor explants from patients progressing during therapy.RESULTS: miR-146a-5p expression was inversely correlated with drug sensitivity and COX2 expression and was reduced in BRAF and MEK inhibitor-resistant melanoma cells and tissues. Forced miR-146a-5p expression reduced COX2 activity and significantly increased drug sensitivity by hampering prosurvival NFkB signaling, leading to reduced proliferation and enhanced apoptosis. Similar effects were obtained by inhibiting COX2 by celecoxib, a clinically approved COX2 inhibitor.CONCLUSIONS: Deregulation of the miR-146a-5p/COX2 axis occurs in the development of melanoma resistance to targeted drugs in melanoma patients. This finding reveals novel targets for more effective combination treatment. Video Abstract

Miaquant, a novel system for automatic segmentation, measurement, and localization comparison of different biomarkers from serialized histological slices

In the clinical practice, automatic image analysis methods quickly quantizing histological results by objective and replicable methods are getting more and more necessary and widespread. Despite several commercial software products are available for this task, they are very little flexible, and provided as black boxes without modifiable source code. To overcome the aforementioned problems, we employed the commonly used MATLAB platform to develop an automatic method, MIAQuant, for the analysis of histochemical and immunohistochemical images, stained with various methods and acquired by different tools. It automatically extracts and quantifies markers characterized by various colors and shapes; furthermore, it aligns contiguous tissue slices stained by different markers and overlaps them with differing colors for visual comparison of their localization. Application of MIAQuant for clinical research fields, such as oncology and cardiovascular disease studies, has proven its efficacy, robustness and flexibility with respect to various problems; we highlight that, the flexibility of MIAQuant makes it an important tool to be exploited for basic researches where needs are constantly changing. MIAQuant software and its user manual are freely available for clinical studies, pathological research, and diagnosis

Endovascular mechanical thrombectomy in basilar artery occlusion: variables affecting recanalization and outcome

Ischemic stroke due to basilar artery occlusion (BAO) is frequently associated with a poor prognosis. To date the most effective therapeutic approach has not been established and little is known about the predictors of clinical outcome. The aim of this study was to describe safety and efficacy of intra-arterial mechanical thrombectomy (IAMT) through latest generation devices in patients with BAO, focusing on those variables that may affect recanalization and clinical outcome. We analyzed retrospectively a series of 32 patients with BAO who underwent IAMT. We assessed the association of some clinical and neuroradiological features with recanalization rate and clinical outcome. Successful recanalization was achieved in 28 out of 32 patients (87.5 %). Symptomatic intracerebral hemorrhage (SICH) was observed in 2/32 patients (6.3 %) and mortality in the first 3 months was 25.0 %. At 3-month follow up evaluation, 13/32 patients (40.6 %) showed a good functional outcome (mRS score ≤2). There were no statistical differences in term of age, gender, risk factors, cause of stroke, recanalization rate, pre-treatment pc-ASPECTS score and SICH frequencies between patients with favorable and unfavorable outcome. Increased length of thrombi was associated with unfavorable clinical outcome at 3 months. Recanalization rate was not affected by any of the variables considered. In BAO, IAMT through newest generation devices has high recanalization rates and low complication frequencies. Length of BAO is an important predictor of clinical outcome

Presentation_1_3D tumor explant as a novel platform to investigate therapeutic pathways and predictive biomarkers in cancer patients.pdf

Immunotherapy with immune checkpoint inhibitors can induce durable clinical responses in different human malignancies but the number of responding patients remains globally modest. The limited therapeutic efficacy of ICI depends on multiple factors, among which the immune suppressive features of the tumor microenvironment play a key role. For this reason, experimental models that enable dissection of the immune-hostile tumor milieu components are required to unravel how to overcome resistance and obtain full-fledged anti-tumor immunity. Recent evidence supports the usefulness of 3D ex vivo systems in retaining features of tumor microenvironment to elucidate molecular and immunologic mechanisms of response and resistance to immune checkpoint blockade. In this perspective article we discuss the recent advances in patient-derived 3D tumor models and their potential in support of treatment decision making in clinical setting. We will also share our experience with dynamic bioreactor tumor explant culture of samples from melanoma and sarcoma patients as a reliable and promising platform to unravel immune responses to immune checkpoint inhibitors.</p

Leukoaraiosis is a predictor of futile recanalization in acute ischemic stroke

Futile recanalization occurs when successful recanalization fails to improve clinical outcome in acute ischemic stroke patients. Predictors of futile recanalization are still debated and may help in selecting patients for reperfusion strategies. We aim to determine whether leukoaraiosis may be useful in predicting futile recanalization in acute ischemic stroke patients treated by endovascular mechanical thrombectomy. We included in the analysis patients with acute ischemic stroke due to anterior circulation large vessel occlusion undergoing endovascular mechanical thrombectomy obtaining complete vessel recanalization. Demographics, vascular risk factors, baseline National Institutes of Health Stroke Scale score, time from symptoms onset to recanalization, Alberta Stroke Program Early CT Score, and leukoaraiosis graded on a 4-point van Swieten scale were collected. We dichotomized patients into those with moderate-severe leukoaraiosis (2-4) versus those with absent-slight leukoaraiosis (0, 1). Outcome measures were symptomatic intracranial hemorrhage, and modified Rankin scale score at 90 days. The relationships among radiological parameters and clinical data with outcome measures were studied with univariate and multivariable analyses. Sixty-eight patients were identified. Recanalization was futile in 32.4% of cases. On multivariable logistic regression analysis, the presence of moderate-severe LA was independent predictors of FR (P = 0.01). Furthermore, higher NIHSS score at baseline (P &lt; 0.01) end endovascular mechanical thrombectomy alone treatment (P &lt; 0.01) resulted associated with futile recanalization. Our results showed that the presence of moderate-severe leukoaraiosis is associated with poor outcome in recanalized patient