Cancer stem cells are critical for cancer initiation, development, and treatment resistance. Our understanding of these processes, and how they relate to glioblastoma heterogeneity, is limited. To ...overcome these limitations, we performed single-cell RNA sequencing on 53586 adult glioblastoma cells and 22637 normal human fetal brain cells, and compared the lineage hierarchy of the developing human brain to the transcriptome of cancer cells. We find a conserved neural tri-lineage cancer hierarchy centered around glial progenitor-like cells. We also find that this progenitor population contains the majority of the cancer's cycling cells, and, using RNA velocity, is often the originator of the other cell types. Finally, we show that this hierarchal map can be used to identify therapeutic targets specific to progenitor cancer stem cells. Our analyses show that normal brain development reconciles glioblastoma development, suggests a possible origin for glioblastoma hierarchy, and helps to identify cancer stem cell-specific targets.
Glioblastoma (GBM) is an aggressive brain tumor that exhibits resistance to current treatment, making the identification of novel therapeutic targets essential. In this context, cellular prion ...protein (PrP
) stands out as a potential candidate for new therapies. Encoded by the PRNP gene, PrP
can present increased expression levels in GBM, impacting cell proliferation, growth, migration, invasion and stemness. Nevertheless, the exact molecular mechanisms through which PRNP/PrP
modulates key aspects of GBM biology remain elusive.
To elucidate the implications of PRNP/PrP
in the biology of this cancer, we analyzed publicly available RNA sequencing (RNA-seq) data of patient-derived GBMs from four independent studies. First, we ranked samples profiled by bulk RNA-seq as PRNP
and PRNP
and compared their transcriptomic landscape. Then, we analyzed PRNP
and PRNP
GBM cells profiled by single-cell RNA-seq to further understand the molecular context within which PRNP/PrP
might function in this tumor. We explored an additional proteomics dataset, applying similar comparative approaches, to corroborate our findings.
Functional profiling revealed that vesicular dynamics signatures are strongly correlated with PRNP/PrP
levels in GBM. We found a panel of 73 genes, enriched in vesicle-related pathways, whose expression levels are increased in PRNP
/PRNP
cells across all RNA-seq datasets. Vesicle-associated genes, ANXA1, RAB31, DSTN and SYPL1, were found to be upregulated in vitro in an in-house collection of patient-derived GBM. Moreover, proteome analysis of patient-derived samples reinforces the findings of enhanced vesicle biogenesis, processing and trafficking in PRNP
/PRNP
GBM cells.
Together, our findings shed light on a novel role for PrP
as a potential modulator of vesicle biology in GBM, which is pivotal for intercellular communication and cancer maintenance. We also introduce GBMdiscovery, a novel user-friendly tool that allows the investigation of specific genes in GBM biology.
Most platforms used for the molecular reconstruction of the tumor-immune microenvironment (TIME) of a solid tumor fail to explore the spatial context of the three-dimensional (3D) space of the tumor ...at a single-cell resolution, and thus lack information about cell-cell or cell-extracellular matrix (ECM) interactions. To address this issue, a pipeline which integrated multiplex spatially resolved multi-omics platforms was developed to identify crosstalk signaling networks among various cell types and the ECM in the 3D TIME of two FFPE (formalin-fixed paraffin embedded) gynecologic tumor samples. These platforms include non-targeted mass spectrometry imaging (glycans, metabolites, and peptides) and Stereo-seq (spatial transcriptomics) and targeted seqIF (IHC proteomics). The spatially resolved imaging data in a two- and three-dimensional space demonstrated various cellular neighborhoods in both samples. The collection of spatially resolved analytes in a voxel (3D pixel) across serial sections of the tissue was also demonstrated. Data collected from this analytical pipeline were used to construct spatial 3D maps with single-cell resolution, which revealed cell identity, activation, and energized status. These maps will provide not only insights into the molecular basis of spatial cell heterogeneity in the TIME, but also novel predictive biomarkers and therapeutic targets, which can improve patient survival rates.
Abstract
Brain Cancer Canada (BCC) is a national, volunteer-driven charity supporting paediatric and adult primary malignant brain tumour research and patient advocacy. To achieve these goals BCC 1) ...awards grants to Canadian doctors and scientists advancing brain cancer research, and 2) advocates for equitable pharmacare for brain cancer patients. BCC is committed to funding innovative research projects, with the aim to improve treatment options for patients. Led by its Scientific Advisory Committee, submissions are reviewed, screened, and undergo a systematic evaluation by the panel. Recommendations on successful proposals are provided to the board for approval. This May, the charity awarded 5 research grants, totaling $380,000 CAD. These projects include supporting the acquisition of a next-generation DNA Sequencer, advancing FET-PET/MRI imaging, pioneering a novel approach to combat Diffuse Intrinsic Pontine Glioma (DIPG), developing a novel dual-hit therapeutic approach for glioblastoma, and other projects focusing on precision medicine. BCC has taken a deliberate and firm stand in highlighting the drug coverage disparities that exist for patients afflicted with brain cancer BCC’s Pharmacare Advocacy Committee has found that disparities exist owing to the lack of a national drug program, and a patchwork of alternative schemes varying by province/territory. These findings are well documented by others. For example, our research shows that temozolomide (TMZ), the global standard of care for treating gliomas, is not covered in 4 provinces. Our pharmacare research on TMZ and 5 other drugs further confirm the disparity in coverage that hinders patient welfare and imposes a confusing and detrimental strain on the healthcare system. With, the dependence on take-home medication increasing, it is critical we take immediate action in supporting this marginalized group. With the support of The Society for Neuro-Oncology, Brain Cancer Canada will be better positioned to reach its goals and support people affected by primary malignant brain tumours.
Abstract
Glioblastoma(GBM - IDH wildtype) is an adult glioma, showing abysmal prognosis. Sequencing technologies show us the existence of a neurodevelopmental frame-work, upon which heterogeneous ...molecular patterns are overlaid. The tumor's functional capacity is the net result of extrinsic+intrinsic molecular factors interacting with each other. These factors affect how cells communicate and organize themselves into complex functional architectures that support their evolution, survival and resistance. Understanding the phenotypic significance of a tumor's architecture, will allow us to understand these processes and compute complex patterns in GBM that are "biologically-relevant". First, we showed, as a proof-of-concept, that "biologically-relevant" signatures are imprinted within the spatial organization of cells using spatial pixel analysis. We used a phase-contrast image dataset of glioblastoma stem cells grown in culture, imaged 4-12hrly, over 12-16 days. We applied 29 hand-engineered pixel features per image, deriving spatial pixel signatures for each of our 17’601 phase-contrast images. Using different computational analytical methods and gene expression from matched bulk RNA datasets, we showed that spatial pixel patterning follows biologically relevant phenotypes. We found samples of images with high PC2 scores had higher mesenchymal/microglia scores, as compared to samples of images with low PC2 scores, which showed higher neurodevelopmental signatures. In addition, we found that mathematical algorithms describing entropy, homogeneity, contrast and complexity were clearly enriched in specific biological groups. Hence, our study showed that the organizational/architectural patterns of biological entities show preservation of fundamental organizational principles. Building upon the above data (which is currently a manuscript under preparation), we will apply these principles towards pattern discovery of GBM tissues at multiple architectural hierarchies (i.e subcellular, cellular, stroma) using different GBM models, imaging and spatial transcriptomics. If structure equates to function, understanding GBM architecture will have important applications in surgical tool developments and understanding relevant mechanistic patterns in GBM.
The Nerve Growth Factor (NGF) is the prototypic member of the neurotrophin (NT) family, which plays an essential role in the development and functioning of the vertebrate nervous system. Although ...originally defined by their actions on neuronal survival and differentiation in the peripheral (PNS) and central nervous systems (CNS), accumulating data indicate the presence of extensive interactions between the NTs and the immune system. NTs are released normally during lymphocyte and leukocyte development by the bone marrow and the thymus and later by secondary lymph organs to maintain responsiveness of these circulating naiive and memory immune cells. Functional NT receptors have been detected on the cells of the immune system and increased levels of NGF protein are found during the acute phase of various diseases with a significant inflammatory component. Furthermore, in certain conditions such as allergic asthma, the released NTs exacerbate the severity of the inflammation and prolong the diseased state. However, in the CNS, if one can control homeostasis of the internal environment, then the natural response of the infiltrating immune cells to release these NTs can be used to intervene at key points in the disease progression. These wider functions are likely to be of concern in any attempted therapeutic use of NGF or related NTs.
γ/δ T cells have a differential susceptibility to immunosenescence compared to α/β T cells, during human aging.
Aging is associated with an increased susceptibility to infections and diseases. It has ...also been associated with reduced functionality and altered distribution of immune cells, especially T cells. Whereas classical α/β T cells, especially CD8+ T cells, were shown to be highly susceptible to aging, the effects of viral persistent stimulations on the fate of γ/δ T cells are much less documented. Healthy, elderly individuals of Chinese ethnical background were recruited under the aegis of SLAS‐II. In this observational study, γ/δ T cell populations were characterized by flow cytometry and compared with the α/β CD4+ and CD8+ T cells in elderly and young controls. In our study, we identified a reduced frequency of γ/δ T cells but not α/β T cells with aging. The classical markers of α/β T cell aging, including CD28, CD27, and CD57, did not prove significant for γ/δ T cells. The extreme range of expression of these markers in γ/δ T cells was responsible for the lack of relationship between γ/δ T cell subsets, CD4/CD8 ratio, and anti‐CMV titers that was significant for α/β T cells and, especially, CD8+ T cells. Although markers of aging for γ/δ T cells are not clearly identified, our data collectively suggest that the presence of CD27 γ/δ T cells is associated with markers of α/β T cell aging.
Cell segmentation is a critical step for quantitative single-cell analysis in microscopy images. Existing cell segmentation methods are often tailored to specific modalities or require manual ...interventions to specify hyper-parameters in different experimental settings. Here, we present a multi-modality cell segmentation benchmark, comprising over 1500 labeled images derived from more than 50 diverse biological experiments. The top participants developed a Transformer-based deep-learning algorithm that not only exceeds existing methods but can also be applied to diverse microscopy images across imaging platforms and tissue types without manual parameter adjustments. This benchmark and the improved algorithm offer promising avenues for more accurate and versatile cell analysis in microscopy imaging.
PDF
