Improving treatment of glioblastoma: new insights in targeting cancer stem cells effectively

Glioblastoma is the most common primary malignant brain tumour in the adult population. Despite multimodality treatment with surgery, radiotherapy and chemotherapy, outcomes are very poor, with less than 15% of patients alive after two years. Increasing evidence suggests that glioblastoma stem cells (GSCs) are likely to play an important role in the biology of this disease and are involved in treatment resistance and tumour recurrence following standard therapy. My thesis aims to address two main aspects of this research area: 1) optimization of methods to evaluate treatment responses of GSCs and their differentiated counterparts (non-GSCs), with a particular focus on a tissue culture model that resembles more closely the tumoral niche; 2) characterization of cell division and centrosome cycle of GSCs, investigating possible differences between these cells and non-GSCs, that would allow the identification of targets for new therapeutic strategies against glioblastomas. In the first part of my project, I optimized a clonogenic survival assay, to compare sensitivity of GSCs and non-GSCs to various treatments, and I developed the use of a 3-dimentional tissue culture system, that allows analysis of features and radiation responses of these two subpopulations in the presence of specific microenvironmental factors from the tumoral niche. In the second part, I show that GSCs display mitotic spindle abnormalities more frequently than non-GSCs and that they have distinctive features with regards to the centrosome cycle. I also demonstrate that GSCs are more sensitive than non-GSCs to subtle changes in Aurora kinase A activity, which result in a rapid increase in polyploidy and subsequently in senescence, with a consistent reduction in clonogenic survival. Based on these findings, I propose that kinases involved in the centrosome cycle need to be explored as a novel strategy to target GSCs effectively and improve outcomes of glioblastoma patients

Differential sensitivity of Glioma stem cells to Aurora kinase A inhibitors: implications for stem cell mitosis and centrosome dynamics

Glioma stem-cell-like cells are considered to be responsible for treatment resistance and tumour recurrence following chemo-radiation in glioblastoma patients, but specific targets by which to kill the cancer stem cell population remain elusive. A characteristic feature of stem cells is their ability to undergo both symmetric and asymmetric cell divisions. In this study we have analysed specific features of glioma stem cell mitosis. We found that glioma stem cells appear to be highly prone to undergo aberrant cell division and polyploidization. Moreover, we discovered a pronounced change in the dynamic of mitotic centrosome maturation in these cells. Accordingly, glioma stem cell survival appeared to be strongly dependent on Aurora A activity. Unlike differentiated cells, glioma stem cells responded to moderate Aurora A inhibition with spindle defects, polyploidization and a dramatic increase in cellular senescence, and were selectively sensitive to Aurora A and Plk1 inhibitor treatment. Our study proposes inhibition of centrosomal kinases as a novel strategy to selectively target glioma stem cells

Reduced humoral response to two doses of COVID-19 vaccine in patients with inflammatory bowel disease: Data from ESCAPE-IBD, an IG-IBD study

Background Patients on immunosuppressive drugs have been excluded from COVID-19 vaccines trials, creating concerns regarding their efficacy. Aims To explore the humoral response to COVID-19 vaccines in patients with inflammatory bowel disease (IBD) Methods Effectiveness and Safety of COVID-19 Vaccine in Patients with Inflammatory Bowel Disease (IBD) Treated with Immunomodulatory or Biological Drugs (ESCAPE-IBD) is a prospective, multicentre study promoted by the Italian Group for the study of Inflammatory Bowel Disease. We present data on serological response eight weeks after the second dose of COVID-19 vaccination in IBD patients and healthy controls (HCs). Results 1076 patients with IBD and 1126 HCs were analyzed. Seropositivity for anti-SARS-CoV-2 IgG was reported for most IBD patients, even if with a lesser rate compared with HCs (92.1% vs. 97.9%; p<0.001). HCs had higher antibody concentrations (median OD 8.72 [IQR 5.2-14-2]) compared to the whole cohort of IBD patients (median OD 1.54 [IQR 0.8-3.6]; p<0.001) and the subgroup of IBD patients (n=280) without any treatment or on aminosalicylates only (median OD 1.72 [IQR 1.0–4.1]; p<0.001). Conclusions Although most IBD patients showed seropositivity after COVID-19 vaccines, the magnitude of the humoral response was significantly lower than in HCs. Differently from other studies, these findings seem to be mostly unrelated to the use of immune-modifying treatments (ClinicalTrials.govID:NCT04769258)

Helical Tomotherapy® is a safe and feasible technique for total scalp irradiation

Angiosarcoma of the scalp is a rare aggressive tumor that affects elderly patients. Chemoradiation is the treatment of choice for multicentric and extensive disease. The shape of the scalp represents a dosimetric challenge in terms of achieving a homogeneous concave dose distribution with coverage of the entire target volume and an acceptable organs-at-risk sparing. We report a case of an 81-year-old man with a multifocal angiosarcoma of the scalp treated with Helical TomoTherapy® (Accuray Inc., Sunnyvale, CA, USA) intensity modulated radiotherapy. This technique allows precise and daily verifiable coverage of the target keeping the dose to the organs at risk within the constraints

Safety, hesitancy of coronavirus disease 2019 vaccination and pandemic burden in patients with inflammatory bowel disease: data of a national study (ESCAPE-IBD)

Background and aims: The purpose of this study was to present data on the safety of anti- severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in a cohort of inflammatory bowel disease (IBD) patients of an ongoing multicenter study (ESCAPE-IBD) sponsored by the Italian Group for the study of Inflammatory Bowel Disease (ClinicalTrials.gov Identifier: NCT04769258). Methods: Anti-SARS-CoV-2 vaccination was administrated to 809 IBD patients. Interviews were conducted to report adverse events related to vaccination. Of these 809, 346 patients were surveyed on the pandemic burden and the main reason for hesitancy in coronavirus disease 2019 vaccination. The chi-square test was used to compare categorical variables. Logistic regression was used to assess the relationship between disease-related characteristics and the onset of adverse events. Results: About 45% of patients had at least one side effect, following the first dose (10%), the second (15%), and both doses (19%). All the adverse events were mild and lasted only a few days. Logistic regression analysis revealed that female sex ( P  < 0.001), younger age ( P  = 0.001), seroconversion ( P  = 0.002), and comorbidity ( P  < 0.001) were significantly associated with adverse events. The survey showed that the main concerns were the possibility of adverse event (33%). Almost all patients (99%) felt safer having been vaccinated at their IBD reference center. Conclusion: The vaccine reactions experienced in IBD patients were mostly self-limited. We found high acceptance and good safety of SARS-CoV-2 vaccination in our cohort