Biology subjects

Muraro, M. G.

Publications and source records attributed to Muraro, M. G..

3 recordsLinked to original sources

bioRxiv2025

Bioengineered human bone-mimetic niche compositions regulatebreast cancer cell quiescence and therapy response

Disseminated tumor cells (DTCs) in the bone are widely regarded as the cellular seeds of late metastatic relapse in estrogen receptor-positive (ER+) breast cancer (BC). However, how distinct bone compartments influence BC cell quiescence and endocrine therapy response remains unclear. Mechanistic insight has been hindered by limited access to human bone samples and by the lack of relevant human models that permit controlled manipulation of stromal compartments. Here, we developed a fully human, 3D bone-mimetic system for modular, controllable assembly of engineered osteoblastic (eON), vascularized (eVN), and vascularized osteoblastic (eVON) niche compositions. These niches were generated by perfusion culture of human bone marrow-derived mesenchymal stromal cells (hBM-MSCs) and/or human adipose tissue-derived stromal vascular fraction (hAT-SVF) cells within porous ceramic scaffolds. The resulting tissue microenvironments were then used as a substrate for the culture of an ER+ BC cell line, expressing a mutant reporter of p27 to monitor the quiescent status. We found that the eON enhanced BC cell proliferation, whereas the eVN was enriched in quiescent BC cells positive for NR2F1, a dormancy-associated transcription factor, and located near perivascular elements. Treatment with the selective ER degrader fulvestrant reduced BC cell numbers in vascularized niches (eVN and eVON) but not in eON, despite comparable receptor degradation. In summary, we developed a modular human platform for dissecting niche-specific regulation of BC quiescence, proliferation, and endocrine therapy response. The system can be further used to investigate perivascular niche-dependent mechanisms of BC cell dormancy and to guide the development of therapeutic strategies preventing recurrence in ER+ BC patients.

bioengineering↗

bioRxiv2025

Dual-lineage human 3D bone niche model reveals osteoclast-driven osteomimicry in prostate cancer

Bone is the predominant site of metastasis in advanced prostate cancer (PCa), yet the mechanisms governing tumor-bone interactions remain incompletely understood. A modular human three-dimensional (3D) in vitro bone niche model is developed that integrates osteoblasts and osteoclasts within a mineralized scaffold, recreating an endosteal-like microenvironment for co-culture with PCa cell lines and patient-derived organoids (PDOs). The engineered construct maintains osteoblastic differentiation and supports osteoclastogenesis, confirmed by lineage markers including osteocalcin, osteopontin (OPN), and tartrate-resistant acid phosphatase (TRAP). Co-culture with PCa cells downregulates osteoblast- and osteoclast-associated genes (IBSP, OPN, TRAP) in bone cells, suggesting tumor-mediated suppression of bone remodeling. Conversely, co-cultured PCa cells exhibit niche-dependent osteomimicry, characterized by upregulation of osteoblastic (SPARC, BGLAP) and osteoclastic (TRAP) markers and strongly regulated by the presence of osteoclasts. The platform also supports engraftment and proliferation of PDOs without PCa-specific exogenous growth factors, underscoring its translational relevance. This osteoblastic-osteoclastic niche model thus provides a human system capturing PCa-bone cell interactions, with potential utility to investigate therapeutic responses in a clinically relevant context. Table of ContentsA human 3D bone niche integrating osteoblasts and osteoclasts enables co-culture with prostate cancer cell lines and patient-derived organoids. The engineered niche (i) models reciprocal phenotypic regulation between bone and cancer cells, (ii) captures osteoclast-enhanced osteomimicry in tumor cells and (iii) establishes a biomimetic platform for mechanistic studies of metastatic prostate cancer cells in bone. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=161 SRC="FIGDIR/small/689049v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@b16ee9org.highwire.dtl.DTLVardef@e8a013org.highwire.dtl.DTLVardef@6543f6org.highwire.dtl.DTLVardef@50fceb_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2022

Immunotherapy of glioblastoma explants induces interferon-γ responses and immune cell rearrangements in tumor center, but not periphery

Recent therapeutic strategies for glioblastoma (GBM) aim at targeting immune tumor microenvironment (iTME) components to induce antitumoral immunity. A patient-tailored, ex vivo drug testing and response analysis platform for GBM would facilitate personalized therapy planning, provide insights into treatment-induced immune mechanisms in the iTME, and enable the discovery of biomarkers of therapy response and resistance. We cultured 47 GBM explants from tumor center and periphery from 7 patients in perfusion bioreactors to assess iTME responses to immunotherapy. Explants were exposed to antibodies blocking the immune checkpoints CD47, PD-1 or or their combination, and were analyzed by highly multiplexed microscopy (CODEX, co-detection by indexing) using an immune-focused 55-marker panel. Culture media were examined for changes of soluble factors including cytokines, chemokines and metabolites. CODEX enabled the spatially resolved identification and quantification of >850,000 single cells in explants, which were classified into 10 cell types by clustering. Explants from center and periphery differed significantly in their cell type composition, their levels of soluble factors, and their responses to immunotherapy. In a subset of explants, culture media displayed increased interferon-{gamma} levels, which correlated with shifts in immune cell composition within specific tissue compartments, including the enrichment of CD4+ and CD8+ T cells within an adaptive immune compartment. Furthermore, significant differences in the expression levels of functional molecules in innate and adaptive immune cell types were found between explants responding or not to immunotherapy. In non-responder explants, T cells showed higher expression of PD-1, LAG-3, TIM-3 and VISTA, whereas in responders, macrophages and microglia showed higher cathepsin D levels. Our study demonstrates that ex vivo immunotherapy of GBM explants enables an active antitumoral immune response within the tumor center in a subset of patients, and provides a framework for multidimensional personalized assessment of tumor response to immunotherapy.

cancer biology↗