Project description:Pancreatic ductal adenocarcinoma (PDAC) remains resistant to most treatments and demonstrates a complex pathobiology. Here, we deconvolute regional heterogeneity in the human PDAC tumor microenvironment (TME), a long-standing obstacle, to define precise stromal contributions to PDAC progression. Large scale integration of histology-guided multiOMICs profiling with clinical data sets and functional in vitro models uncovered two microenvironmental programs in PDAC that were anchored in fibroblast differentiation states. These sub-tumor microenvironments (subTMEs) co-occurred intratumorally and were spatially confined, producing patient-specific cellular and molecular heterogeneity associated with shortened patient survival. Each subTME was uniquely structured to support discrete aspects of tumor biology: reactive regions rich in activated fibroblast communities were immune-hot and promoted aggressive tumor progression while deserted regions enriched in extracellular matrix supported tumor differentiation yet were markedly chemoprotective. In conclusion, PDAC regional heterogeneity derives from biologically distinct reactive and protective TME elements with a defined, active role in PDAC progression.
Project description:OCT-embedded PDAC tissues were assessed for stromal and tumour epithelial regions which were both laser-capture microdissected from 33 patients. Integration of these proteomic profiles with transcriptomic data lead to the identification of two spatially confined tumour microenvironment programs: deserted and reactive.
Project description:We aimed to investigate how different three-dimensional microenvironments regulate the early differentiation of the three germ layers in human embryonic stem cells derived embryoid bodies. In particular, a permeable, biocompatible, hydrogel microwell array was specifically designed for recreating a confined niche in which EB secreted molecules accumulate in accordance with hydrogel diffusional cut-off. Fluorescence recovery after photobleaching technique was performed to accurately evaluate hydrogel permeability, mesh size and diffusional cutoff for soluble molecules. EBs culture in microwells promotes the expression of genes involved in pattern specification processes, brain development, ectoderm and endoderm differentiation. On the contrary, suspension EBs express instead genes involved in mesoderm specification and heart development. These results suggest that local accumulation of EBs secreted molecules drives differentiation patterns, as confirmed by immunofluorescence of germ layer markers, in hydrogel confined EB culture. Three different culture conditions of EB culture were analyzed: suspension (standard condition), confinement in microwells of width/depth ratio 1:1 and 1:2. EBs cultured in microwells are viable and have comparable average size after 8 days culture. Whole genome microarrays show that significative differential gene expression was observed between suspension and confined EBs culture.
Project description:Our work offers a novel concept of spatially confined microbiota, advancing sustainable biomanufacturing and function-robust microbiota design.
Project description:The spatial organization of cells within tissues is tightly linked to their biological function. Yet, methods to probe the entire transcriptome of multiple native tissue microenvironments at single cell resolution are lacking. Here, we introduce fragment-sequencing, a method that enables the transcriptomic characterization of single cells within spatially distinct tissue niches. Fragment-sequencing of the mouse metastatic liver revealed previously uncharacterized zonated genes and ligand-receptor interactions enriched in the different hepatic microenvironments and the metastatic niche.
Project description:We aimed to investigate how different three-dimensional microenvironments regulate the early differentiation of the three germ layers in human embryonic stem cells derived embryoid bodies. In particular, a permeable, biocompatible, hydrogel microwell array was specifically designed for recreating a confined niche in which EB secreted molecules accumulate in accordance with hydrogel diffusional cut-off. Fluorescence recovery after photobleaching technique was performed to accurately evaluate hydrogel permeability, mesh size and diffusional cutoff for soluble molecules. EBs culture in microwells promotes the expression of genes involved in pattern specification processes, brain development, ectoderm and endoderm differentiation. On the contrary, suspension EBs express instead genes involved in mesoderm specification and heart development. These results suggest that local accumulation of EBs secreted molecules drives differentiation patterns, as confirmed by immunofluorescence of germ layer markers, in hydrogel confined EB culture.