Project description:Intra-tumor heterogeneity of tumor-initiating cell (TIC) activity drives colorectal cancer (CRC) progression and therapy resistance. Here, we used single-cell mRNA-sequencing (scRNA-seq) of patient-derived CRC models to decipher distinct cell subpopulations based on their transcriptional profiles. Cell type-specific expression modules of stem-like, transit amplifying-like, and differentiated CRC cells resemble differentiation states of normal intestinal epithelial cells. Strikingly, identified subpopulations differ in proliferative activity and metabolic state. In summary, we here show at single-cell resolution that transcriptional heterogeneity identifies functional states during TIC differentiation. Targeting transcriptional states associated to cancer cell differentiation might unravel vulnerabilities in human CRC.
Project description:Brain metastasis (BrM) represents the most common and aggressive brain malignancy, predominantly arising from non-small cell lung cancer, breast cancer, and melanoma. Recent studies have revealed the importance of the brain tumor microenvironment (TME), notably diverse immune cells, which play important roles in regulating cancer progression in both primary and metastatic brain malignancies. The blood-brain barrier (BBB) is another critical TME component formed by endothelial cells, mural cells, astrocytic end-feet, and closely-associated microglial cells. Metastasizing cancer cells can utilize different strategies to traverse the BBB and once they have successfully seeded and colonized the brain, they can exploit the vasculature for their own benefit, forming the blood-tumor barrier. To explore the mechanisms underlying tumor vascularization in brain metastasis we performed a comprehensive multiomic analysis of the key components of the tumor vasculature. We integrated single-cell and/or bulk RNA sequencing of sorted endothelial and mural cells isolated from human and mouse BrM and non-tumor samples; immunofluorescence imaging analysis of the spatial architecture of the TME; and functional studies using BrM mouse models to target vascular regulators of tumor immunity. Our results provide a comprehensive understanding of the biology underlying vascularization in metastatic brain tumors, specifically highlighting the importance of vascular cells as immune regulators and proposing novel therapeutic strategies for these aggressive tumors.
Project description:The glioblastoma (GBM) microenvironment contains resident immune cells with intrinsic anti-tumor potential, particularly microglia. Understanding the single-cell spatial heterogeneity and interactions between immune cells and brain tumor–initiating cells (BTICs) is essential for identifying therapeutic targets to reprogram immune responses and suppress BTIC growth. Using single-cell and spatial transcriptomics, we mapped immune cell populations in the GBM microenvironment and identified signaling networks mediating immune–cancer cell interactions. We discovered a previously unrecognized subset of microglia expressing protein kinase Cδ (PKCδ) with anti-tumor activity against BTICs. The presence of PKCδ-expressing microglia was validated in human GBM specimens. Enhancing PKCδ in microglia via adeno-associated virus or niacin increased phagocytosis of patient-derived BTICs in vitro and improved survival in GBM-bearing mice. Data from The Cancer Genome Atlas (TCGA) revealed that high PKCδ expression correlates with increased apoptosis, phagocytosis, and immune signaling pathways. These findings offer highlight PKCδ+ microglia as a promising therapeutic target in GBM.
Project description:The glioblastoma (GBM) microenvironment contains resident immune cells with intrinsic anti-tumor potential, particularly microglia. Understanding the single-cell spatial heterogeneity and interactions between immune cells and brain tumor–initiating cells (BTICs) is essential for identifying therapeutic targets to reprogram immune responses and suppress BTIC growth. Using single-cell and spatial transcriptomics, we mapped immune cell populations in the GBM microenvironment and identified signaling networks mediating immune–cancer cell interactions. We discovered a previously unrecognized subset of microglia expressing protein kinase Cδ (PKCδ) with anti-tumor activity against BTICs. The presence of PKCδ-expressing microglia was validated in human GBM specimens. Enhancing PKCδ in microglia via adeno-associated virus or niacin increased phagocytosis of patient-derived BTICs in vitro and improved survival in GBM-bearing mice. Data from The Cancer Genome Atlas (TCGA) revealed that high PKCδ expression correlates with increased apoptosis, phagocytosis, and immune signaling pathways. These findings offer highlight PKCδ+ microglia as a promising therapeutic target in GBM.
Project description:Spatial proteomics is essential for resolving molecular heterogeneity and tissue microenvironment, yet it remains constrained by trade‑offs among spatial resolution, analytical throughput, and proteome depth. Here we present SMID‑MOSF, an ultra‑trace and rapid sample preparation strategy based on macroporous ordered siliceous foams-assisted single‑pot, miniaturized in‑solution digestion. Coupled with laser capture microdissection-based in situ sampling, SMID-MOSF enables high‑resolution, deep spatial proteomic profiling within a streamlined workflow. SMID‑MOSF identified over 3700 protein groups from single HEK 293T cells and more than 3000 protein groups from 50-μm mouse brain tissue voxels. The method reduces digestion time to 10 minutes, is compatible with high-resolution grid-based sampling formats, and completes within 1.5 hours, enabling scalable spatial analyses. Applied to human oligodendroglioma and brain metastasis tissues, SMID‑MOSF quantified over 4100 protein groups at 50-μm spatial resolution, delineating histopathological regions and mapping tumor heterogeneity. Integration with flow cytometry-derived immune cell proteomic references and spatial deconvolution further revealed distinct immune microenvironmental features between the two tumor types. Together, SMID‑MOSF provides a scalable framework for whole‑tissue spatial proteomics and broadens access to high‑depth in situ proteome analysis.