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Biology subjects

Miele, E.

Publications and source records attributed to Miele, E..

5 recordsLinked to original sources

De novo H3.3K27M-altered Diffuse Midline Glioma in human brainstem organoids to dissect GD2 CAR T cell function

Diffuse midline glioma (DMG) is a rare yet highly aggressive paediatric cancer primarily arising in the pontine region of the brainstem, necessitating the development of scalable patient-representative models for treatment advance1,2. Here, we developed an FGF4-driven human brainstem organoid model, with high representation of pontine glial lineages. By genetically engineering de novo H3.3K27M-altered DMG, we show that this brainstem glial specification is essential for driving DMG tumorigenesis, resulting in tumours that recapitulate the infiltrative nature and molecular heterogeneity of patient samples. By performing prolonged GD2 CAR T cell treatment in this model, we could mirror variable treatment outcomes as observed in the clinic3,4 and demonstrate a high level of CAR T cell transcriptional heterogeneity. From these CAR T cell functional states, we could identify the most potent effector population and validated NCAM1 as a selection marker for their enrichment. In contrast, NCAM1- cells were linked to a cellular stress response, previously associated to immunotherapy resistance5. Furthermore, incorporating the brain-resident myeloid compartment resulted in DMG-specific, largely immunosuppressive microglia subtypes6. These disease-representative microglia reduced GD2 CAR T cell treatment efficacy and we identified the functional profiles most susceptible to this microglia-dependent immune modulation. Thus, we present a scalable human DMG model with critical applications towards understanding CAR T cell functionality to aid therapy development for this detrimental disease.

cancer biology↗

Spatio-Temporal Multi-Omics Profiling of Mechanisms and Biomarkers in Inhaled Drug-Induced Lung Toxicity

Comprehensive understanding and early detection of drug-induced lung toxicity remain critical challenges in respiratory drug development. In this study, we propose a multi-omics framework that integrates spatial and temporal tissue-specific transcriptomic signatures with proteomics from minimally invasive biofluids to understand mechanisms and identify safety biomarkers associated with lung toxicity. Using this framework, we identified a panel of candidate biomarkers in bronchoalveolar lavage fluid and plasma, including LCN2/NGAL, RETNLA, SP-D, SPP1/osteopontin, and MMP7, that correlate with histopathological features (e.g., inflammation and epithelial remodeling). We confirmed that these molecular biomarkers were consistently dysregulated across a range of inhaled lung toxicants, human disease (IPF), and environmental exposures (smoke, Alternaria), demonstrating broad applicability across different toxic exposures and translatability. Collectively, this study establishes a robust workflow for mechanism-guided biomarker discovery and proposes a panel of candidates for monitoring drug-induced lung injury in humans.

systems biology↗

Mitochondrial sites of contact with the nucleus aid in chemotherapy evasion of glioblastoma cells

Glioblastoma (GBM) is the most common form of a malignant primary brain tumour in adults for which therapeutic options are minimal. The rapid onset of the resistance mechanisms against the chemotherapeutic agent Temozolomide (TMZ), the first line of pharmacological care for patients, prevents the long-term validity of this approach. The underpinning biology for this remains poorly understood thus compromising the efficacy of this approach. The Translocator Protein (TSPO) is an 18kDa ubiquitous cholesterol-binding molecule on the outer membrane of mitochondria (OMM). Upregulated in cancers TSPO is required to form contacts between mitochondria and the nucleus termed: Nucleus Associated Mitochondria (NAM). In GBM tissues as well as in 2D and 3D cell cultures we assayed patterns of TSPO expression (i), autophagy/mitophagy (ii), transcription factors (iii) and susceptibility to TMZ-induced demise (iv). Confocal and ultrastructural imaging detailed the organization and redistribution of the mitochondrial network (v). Our findings show that TMZ exploits mitochondria via TSPO to aid the formation of NAM which couples the expression of the nuclear transcription factor Sterol regulatory element-binding transcription factor 1 (SREBP1) and the stabilization of YAP/TAZ. Pharmacological modulation of TSPO counteracts all the above and re-instates susceptibility to TMZ-induced demise. NAM is therefore proposed as a variable in the engagement and execution of pro-survival mechanisms in GBM thus offering a means to both insight into the pathophysiology of this disease and offer novel therapeutic strategies. Key PointsO_LITMZ exploits TSPO to curb mitochondrial quality control in glioblastoma cells. C_LIO_LITMZ-mediated MRR is associated with the relocation of mitochondria to the nucleus and modulation of transcriptional factors involved in cholesterol metabolism and adaptation to aggressive growth. C_LIO_LITSPO represents a pharmacological target to revert chemoresistance in glioblastoma cells. C_LI Importance of the StudyThis study elucidates a mitochondrion-driven mechanism of chemoresistance in human glioblastoma cells, which depends on the mitochondrial translocator protein TSPO. The administration of TSPO ligands restores susceptibility to TMZ by influencing the dynamics of transcriptional factors associated with cholesterol metabolism and mechanical transduction.

cancer biology↗

Distribution of GOPC:ROS1 and other ROS1 fusions in glioma types

The ROS proto-oncogene 1 (ROS1) gene is rearranged in various cancers. The translated fusion protein presents an attractive therapeutic target, since specific inhibitors have been approved for several tumor types. In glioma, ROS1 fusions are frequent within infantile hemispheric glioma, and single case reports on occurrences in other glioma types exist. However, a comprehensive analysis spanning the full width of glioma types and subtypes is lacking. We here assessed the spectrum and distribution of ROS1 fusions by screening >20,000 glioma cases for typical chromosomal alterations, with subsequent RNA-sequencing for confirmation of candidate cases. ROS1 fusions were identified in 16 cases, from low grade pilocytic astrocytoma WHO grade 1 to glioblastoma, IDH wildtype WHO grade 4. Thus, despite being enriched in some tumor types, ROS1 fusions are not pathognomonic for specific glioma types and may consitute a relevant target in a variety of cases.

genomics↗

Drug screening linked to molecular profiling identifies novel dependencies in patient-derived primary cultures of paediatric high grade glioma and DIPG

Paediatric high grade glioma and diffuse midline glioma (including DIPG) are comprised of multiple biological and clinical subgroups, the majority of which urgently require novel therapies. Patient-derived in vitro primary cell cultures represent potentially useful tools for mechanistic and preclinical investigation based upon their retention of key features of tumour subgroups under experimental conditions amenable to high-throughput approaches. We present 17 novel primary cultures derived from patients in London, Dublin and Belfast, and together with cultures established or shared from Barcelona, Brisbane, Rome and Stanford, assembled a panel of 52 models under 2D (laminin matrix) and/or 3D (neurospheres) conditions, fully credentialed by phenotypic and molecular comparison to the original tumour sample (methylation BeadArray, panel/exome sequencing, RNAseq). In screening a subset of these against a panel of ~400 approved chemotherapeutics and small molecules, we identified specific dependencies associated with tumour subgroups and/or specific molecular markers. These included MYCN-amplified cells and ATM/DNA-PK inhibitors, and DIPGs with PPM1D activating truncating mutations and inhibitors of MDM2 or PARP1. Specific mutations in PDGFRA were found to confer sensitivity to a range of RTK inhibitors, though not all such mutations conferred sensitivity to targeted agents. Notably, dual PDGFRA/FGFR and downstream pathway MEK inhibitors showed profound effects against both PDGFRA-sensitising mutant and FGFR1-dependent non-brainstem pHGG and DIPG. In total, 85% cells were found to have at least one drug screening hit in short term assays linked to the underlying biology of the patients tumour, providing a rational approach for individualised clinical translation.

cancer biology↗