Biology subjects

Hocke, E.

Publications and source records attributed to Hocke, E..

4 recordsLinked to original sources

bioRxiv2025

HIV-associated non-Hodgkin lymphoma tumor-microenvironment axes differ by EBV status across cellular origins

Non-Hodgkin Lymphoma (NHL) is the main cancer-related mortality for people living with HIV (PLWH). NHL genetic and molecular classifications have been intensely studied and correlated with clinical outcomes, but critical unanswered questions relevant to malignancy persist. For example, tumors positive for Epstein-Barr virus (EBV) are aggressive and account for 30-50% of HIV-associated NHLs, yet insights on the nature of EBV in NHL pathogenesis or potential therapeutic vulnerabilities have been limited. Here, we examined HIV-associated NHLs stratified by histopathologic classification, cell of origin (COO), molecular subtype, and EBV status using genome-wide spatial transcriptomic analyses. Tumor tissues in EBV+ HIV-NHLs displayed enriched expression of mitochondrial respiration and purine metabolism signatures versus EBV- tumors. Immune infiltration of EBV+ tumors was limited, and immune and stromal regions of EBV+ HIV-NHLs displayed upregulation of the gene for the iron exporter ferroportin (SLC40A1), indicating immunosuppressive macrophage polarization. An immunosuppressive SPP1-CD44 axis and oncogenic GAS6-AXL interaction between tumor and stroma were specifically predicted for EBV+ HIV-NHLs with plasmablastic features. Tumor microenvironment (TME) similarities to secondary lymphoid tissues such as inverse CXCL12-CXCL13 gradients and evidence of matching between tumor B cell phenotypes and reticular cell signatures were also observed. Finally, we developed a simple yet flexible approach to quantify expression gradients and cell proximity to annotated regions. Thus, this study highlights potential avenues for NHL therapy tailored by EBV status and provides a unique resource to examine tumor-TME interactions in the HIV-immunocompromised context. Key PointsO_LISpatial transcriptomic landscapes resolve cell-of-origin- and EBV-associated HIV-NHL heterogeneity including immunosuppressive myeloid responses to EBV+ tumors C_LIO_LISpatial gradients including CXCL12 and CXCL13 indicate that tumor-stromal interactions mimic lymphoid tissue organization and depend on B cell development stage C_LIO_LIDevelopment of a direction-agnostic method to calculate spatial expression gradients relative to annotated tissue and cell types of interest C_LIO_LIPredicted pharmacologic vulnerabilities in clinical samples are replicated in vitro and confirmed by small molecule screening C_LI

cancer biology↗

bioRxiv2025

Multi-region spatial transcriptomics reveals region specific differences in response to amyloid beta (Aβ) plaque induced changes in Alzheimer's Disease (AD)

Alzheimers disease (AD) is the leading cause of dementia affecting 55 million people worldwide. The pathological hallmarks of AD, beta-amyloid (A{beta}) plaques and neurofibrillary tangles (NFT), follow distinct stereotypical patterns of progression across brain regions and trigger a multicellular response that ultimately leads to neuronal loss and cognitive decline. Despite the uniform spread of A{beta} plaque across the cortex during AD progression, different regions demonstrate varying levels of vulnerability and resilience to temporal A{beta} plaque induced changes, such as NFT accumulation. There is a critical gap in our understanding of the cell types and molecular mechanisms that underlie these region-specific differences in resilience to A{beta} plaque induced changes. In this study, we hypothesized that brain region and cell type specific transcriptional responses within the A{beta} microenvironment, and more broadly within the grey matter, may contribute to this variation. We carried out matched multi-region spatial transcriptomics and A{beta} immunofluorescence staining from the entorhinal, occipito-temporal, dorsolateral prefrontal and striate cortices from two individuals with Braak III and Thal 4 AD. Spatiotemporal comparisons of cell type proportions, gene expression, and cell-cell communication revealed differences in the vulnerability of somatostatin and somatostatin chondrolectin inhibitory neurons and the expression of endosomal and lysosomal trafficking and metallothionein genes within the A{beta} plaque microenvironment. We also observed variations in blood-brain-barrier dysfunction, fibroblast growth factor signaling, and vascular impairment and repair related cell-cell communication networks within the grey matter. Our results demonstrate the value of simultaneously profiling AD-omic and spatial modalities in multiple regions to elucidate how cortical region-specific differences contribute to selective vulnerability and resilience during neurodegeneration.

genomics↗

bioRxiv2023

Ataxia-telangiectasia mutated (Atm) disruption sensitizes spatially-directed H3.3K27M/TP53 diffuse midline gliomas to radiation therapy

Diffuse midline gliomas (DMGs) are lethal brain tumors characterized by p53-inactivating mutations and oncohistone H3.3K27M mutations that rewire the cellular response to genotoxic stress, which presents therapeutic opportunities. We used RCAS/tv-a retroviruses and Cre recombinase to inactivate p53 and induce K27M in the native H3f3a allele in a lineage- and spatially-directed manner, yielding primary mouse DMGs. Genetic or pharmacologic disruption of the DNA damage response kinase Ataxia-telangiectasia mutated (ATM) enhanced the efficacy of focal brain irradiation, extending mouse survival. This finding suggests that targeting ATM will enhance the efficacy of radiation therapy for p53-mutant DMG but not p53-wildtype DMG. We used spatial in situ transcriptomics and an allelic series of primary murine DMG models with different p53 mutations to identify transactivation-independent p53 activity as a key mediator of such radiosensitivity. These studies deeply profile a genetically faithful and versatile model of a lethal brain tumor to identify resistance mechanisms for a therapeutic strategy currently in clinical trials.

cancer biology↗

bioRxiv2020

Digoxin Targets Central Carbon Metabolism and Remodels the Tumor Microenvironment

Cancer therapies targeting metabolism have been limited due to a lack of understanding of the controlling properties of vulnerable pathways. The Na+/K+ ATPase is responsible for a large portion of cellular energy demands but how these demands influence metabolism and create metabolic liabilities are not known. Using metabolomic approaches, we first show that digoxin, a cardiac glycoside widely used in humans, acts through disruption to central carbon metabolism via on target inhibition of the Na+/K+ ATPase that was fully recovered by expression of an allele resistant to digoxin. We further show in vivo that administration of digoxin inhibits glycolysis in both malignant and healthy cells, particularly within clinically relevant cardiac tissue, while exhibiting tumor-specific cytotoxic activity in an allografted soft tissue sarcoma. Single-cell expression analysis of over 31,000 cells within the sarcoma shows that acute Na+/K+ ATPase inhibition shifts the immune composition of the tumor microenvironment, leading to selective alterations to metabolic programs in specific immune cells thus acting both through tumor cell and microenvironmental (e.g. macrophage) cells. These results provide evidence that altering energy demands can be used to regulate glycolysis with cell-type specific consequences in a multicellular environment of biomedical interest.

cancer biology↗