Multidisciplinary and Multiomic approach to dissect the cellular network in the glioma microenvironment: translational perspective to improve patient's management

Glioblastoma Multiforme (GBM) is the most common and deadly primary brain tumor with median survival less than one year. The poor clinical outcome of patients with GBM underscores the urgent need of effective therapies. Immunotherapy has revolutionized the treatment of multiple malignancies but this success has not been translated to GBM. Considering the low efficacy of standard treatments and immunotherapy on patients' prognosis, the aim of this project is to investigate the role and the complexity of the tumor cells and tumor microenvironment (TME) interaction in GBM as a predictive factor for immunotherapy response and risk of recurrence. Preliminary data show that myeloid infiltrates obtained from different TME areas retain different immunosuppressive activities and T cells express different combination of immune checkpoints markers. Therefore, a global vision of the immune response present in the TME is fundamental to understand mechanisms of tumor resistance to immunotherapy, to identify new therapeutic strategies that combine immunostimulatory treatments with effective reduction of the immune suppression mechanisms. To this aim our multidisciplinary project plans to combine the expertise of four operative units in order to dissect the TME of GBM patients. In particular, OU1 will perform Single cell RNA sequencing on immune cells obtained from different tumor layers and will share data with other units, to dissect the composition of the tumor infiltrate and to evaluate the different functional properties of distinct cell subsets. Additionally, phenotypical, functional and metabolic properties of lymphoid and myeloid cells will be assessed by OU1, OU3 and OU2 respectively, trough omic-platforms.
A deeper understanding of brain permeability through the BBB is essential to clarify how immune cells are recruited to the tumor mass and also how possible immunotherapies could be delivered to reach their target. In this context, OU4 expertise is essential in order to delineate the contribution of Blood Brain Barrier (BBB) cell and protein components (among which AQP4) in tumor progression and alteration of electrophysiological parameters. All obtained results will be also finalized recreating an in vitro model of TME through co-culture of organoids engrafted with GSCs generated by OU4 and different immune cells studied by the other three research units. This model will allow us to assess the efficacy of immune checkpoint inhibitors and other immunotherapy, both in terms of delivery and biological activity.