January 2025
·
27 Reads
Neuron
This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.
January 2025
·
27 Reads
Neuron
January 2025
·
30 Reads
The Journal of clinical investigation
Colorectal cancer (CRC) remains a leading cause of cancer death due to metastatic spread. LIN28B is overexpressed in 30% of CRCs and promotes metastasis, yet its mechanisms remain unclear. In this study, we genetically modified CRC cell lines to overexpress LIN28B, resulting in enhanced PI3K/AKT pathway activation and liver metastasis in mice. We developed genetically modified mouse models with constitutively active Pik3ca that form intestinal tumors progressing to liver metastases with an intact immune system, addressing the limitations of previous Pik3ca-mutant models, including long tumor latency, mixed histology, and lack of distant metastases. The PI3Kα-specific inhibitor alpelisib reduced migration and invasion in vitro and metastasis in vivo. We present the first comprehensive analysis of vertical inhibition of the PI3K/AKT pathway in CRC using FDA-approved drugs alpelisib and capivasertib (an AKT inhibitor) in combination with LY2584702 (an S6K inhibitor) in CRC cell lines and mouse- and patient-derived organoids (PDOs). Tissue microarrays from CRC patients confirmed that LIN28B and PI3K/AKT pathway activation correlate with CRC progression. These findings highlight the critical role of the LIN28B-mediated PI3K/AKT pathway in CRC metastasis, the therapeutic potential of targeted inhibition, and the promise of PDOs in precision medicine in metastatic CRC.
January 2025
·
14 Reads
·
1 Citation
Cell Reports Methods
December 2024
·
10 Reads
Cellular and Molecular Gastroenterology and Hepatology
November 2024
·
22 Reads
Development of therapeutic approaches that target specific microglia responses in amyotrophic lateral sclerosis (ALS) is crucial due to the involvement of microglia in ALS progression. Our study identifies the predominant microglia subset in human ALS primary motor cortex and spinal cord as an undifferentiated phenotype with dysregulated respiratory electron transport. Moreover, we find that the interferon response microglia subset is enriched in donors with aggressive disease progression, while a previously described potentially protective microglia phenotype is depleted in ALS. Additionally, we observe an enrichment of non-microglial immune cell, mainly NK/T cells, in ALS central nervous system, primarily in the spinal cord. These findings pave the way for the development of microglia subset-specific therapeutic interventions to slow or even stop ALS progression.
November 2024
·
37 Reads
Neuro-Oncology
INTRODUCTION Many glioblastoma (GBM) treatments fail because they treat tumor cells in isolation and ignore the surrounding microenvironment. In our phase 1b clinical trial of delivery of Topotecan (TPT) via Convection Enhanced Delivery (CED) in glioma, we demonstrated effective tumor cell elimination accompanied by a robust inflammatory response. We hypothesized that TPT induces an immunogenic response resulting in an unfavorable inflammatory landscape. METHODS To characterize chemotherapy’s effect on myeloid cells, we analyzed pre- and post-treatment biopsies from our trial using bulk RNA sequencing to measure canonical myeloid markers. We validated survival benefit of CED in vivo in our tumor model and characterized post-treatment tissue using single cell RNA sequencing (scRNA seq) after 7 days of treatment. We treated slice cultures generated from surgical samples of GBM with TPT and performed scRNA seq and histologic analysis to assess microenvironment changes after 24 hours of treatment. We used several in vitro assays to characterize the direct and indirect mechanisms of myeloid activation. RESULTS Bulk RNA sequencing of post treatment biopsies demonstrates upregulation of markers associated with activated and exhausted immune cell populations such as IBA1, CD68, MSR1, MARCO and loss of markers associated with homeostatic microglia such as P2RY12 and TMEM119. Similar results are found within 7 days of treatment in vivo, however, are not found in human derived samples treated acutely. Treatment of in vitro mono and co-culture systems demonstrate a tumor cell death dependent activation of myeloid cell populations via immunogenic molecules. CONCLUSIONS Chemotherapies eliminate proliferating glioma cells but also induce inflammation. While many investigators have tried to leverage this activation, our results suggest that chronic inflammation contributes to poor prognosis and recurrence. The identification of molecules responsible for this activation point to new therapeutic targets aimed at controlling treatment-induced inflammation, as part of a combinatorial approach to treat GBM.
November 2024
·
37 Reads
Neuro-Oncology
Dexamethasone is the most widely utilized drug for glioblastoma (GBM). However, systemic delivery of dexamethasone in GBM patients is associated with significant side effects and increasing doses with worse survival. Convection-enhanced delivery (CED) can deliver high doses of immunotherapy directly into the tumor microenvironment (TME) while avoiding systemic toxicity. Here, we report that high doses of dexamethasone can be delivered locally by CED without side effects and increase survival in a GBM model along with reduced inflammatory myeloid signatures. We investigated CED of dexamethasone treatment on survival(n=40), adverse side effects, and the immunological TME through peripheral analyses, liquid chromatography–mass spectrometry, and histology in a preclinical syngeneic mouse model. Additionally, we assessed the transcriptional responses of human GBM slices and stem-cell-derived human microglia after steroid treatment through bulk and single-cell RNA sequencing. We found that 7-day treatment with CED of dexamethasone produced a significant survival advantage in glioma-bearing mice compared to non-treated control(p=0.03). Systemic dexamethasone achieved low levels of drug in the TME and caused dysregulated blood glucose, blood counts, and peripheral organ weights, while high CED doses avoided these side effects(p< 0.05 each). Steroid treatment of acute GBM slices and lipopolysaccharide-activated microglia in-vitro both reversed inflammatory myeloid signatures associated with poor survival and recurrence on RNA sequencing analyses. We demonstrate the preclinical efficacy of delivering high local doses of dexamethasone in a GBM model through CED and observed prolonged survival along with reduced adverse inflammatory myeloid signatures. No side effects were demonstrated after chronic CED treatment of dexamethasone while systemic delivery achieved poor tumor penetration and caused known hematologic and metabolic side effects supporting the potential to optimize the clinical use of this therapy. CED of dexamethasone provides us a new treatment paradigm to locally control inflammatory signatures in the glioma TME in a controlled fashion.
November 2024
·
14 Reads
Neuro-Oncology
While immune checkpoint blockade (ICB) is not effective in unselected glioblastoma (GBM) patients, we previously established that MAPK/ERK signaling is associated with overall survival following anti-PD-1 and anti-CTLA-4 treatment in recurrent GBM. However, the causal relationship between MAPK/ERK signaling and susceptibility to ICB, as well as the mechanisms underlying this association, remain to be determined. We conducted in vivo kinome-wide CRISPR/Cas9 screenings in murine gliomas to identify key regulators of susceptibility to anti-PD-1 and CD8+ T-cell response and performed survival studies to validate the most relevant hits. Additionally, paired scRNA-seq with p-ERK staining, spatial transcriptomics, and ex-vivo slice culture of BRAFV600E mutant GBM tumors treated with BRAFi/MEKi were used to determine the causal relationship between MAPK signaling, tumor cell immunogenicity, and modulation of microglia phenotype. Our CRISPR/Cas9 screening results identified the MAPK pathway, particularly the RAF-MEK-ERK pathway, as the most critical modulator of glioma susceptibility to anti-tumoral immunity across all kinases. Survival studies showed that mice bearing high p-ERK gliomas exhibited prolonged survival with anti-PD-1 treatment, which was not seen when ERK phosphorylation diminished. MAPK activation in murine gliomas led to durable anti-tumoral immunity upon implant re-challenge, with memory T cell infiltration in long-term survivors. Elevated p-ERK in glioma cells was associated with interferon responses and antigen presentation. Moreover, in BRAFV600E human GBM cells with ERK1/2 knockout and in slice cultures of human BRAFV600E GBM tissue analyzed by spatial transcriptomics, we observed modulation of interferon responses by the MAPK/ERK pathway. Notably, in slice cultures from BRAFV600E mutant GBM, BRAFi/MEKi treatment disrupted the interaction between tumor cells and tumor-associated macrophages/microglia. In conclusion, the MAPK/ERK pathway is a critical driver of GBM susceptibility to anti-tumoral immunity, modulating the interferon responses and antigen-presenting machinery in glioma cells, as well as tumor cell interaction with the microenvironment.
November 2024
·
34 Reads
·
2 Citations
Immunity
November 2024
·
38 Reads
iScience
While mitotic spindle inhibitors specifically kill proliferating tumor cells without the toxicities of microtubule poisons, resistance has limited their clinical utility. Treating glioblastomas with the spindle inhibitors ispinesib, alisertib, or volasertib creates a subpopulation of therapy induced senescent cells that resist these drugs by relying upon the anti-apoptotic and metabolic effects of activated STAT3. Furthermore, these senescent cells expand the repertoire of cells resistant to these drugs by secreting an array of factors, including TGFβ, which induce proliferating cells to exit mitosis and become quiescent—a state that also resists spindle inhibitors. Targeting STAT3 restores sensitivity to each of these drugs by depleting the senescent subpopulation and inducing quiescent cells to enter the mitotic cycle. These results support a therapeutic strategy of targeting STAT3-dependent therapy-induced senescence to enhance the efficacy of spindle inhibitors for the treatment of glioblastoma.
... HC involves categorizing data points into classes that follow a predefined hierarchy or taxonomy. This approach is particularly useful for categories with inherent relationships, such as applications in text classification [43][44][45], functional genomics [46][47][48][49][50][51][52], and image classification [53][54][55][56][57][58][59]. In the field of remote sensing, HC has proven effective for various tasks, such as land cover classification [60][61][62] and hyperspectral image analysis [63][64][65][66]. ...
January 2025
Cell Reports Methods
... Bulk-RNA sequencing analyses on these biopsies demonstrated a significant correlation with the histological analysis, and post-treatment biopsies revealed increases in several proinflammatory cytokines and immunoreactive markers [19]. In other emerging treatments for rGBM, histological analyses of CD68 alongside RNA sequencing also revealed an inflammatory response following treatment [59]. ...
August 2024
The EMBO Journal
... These phosphoantigens are sensed by the butyrophilin-3A1 and butyrophilin-2A1 complex. Vδ1 T cells are abundant in mucosal tissues but are also found in peripheral blood, albeit at a lower frequency, and the antigens recognized by their TCR are less well defined [23,24]. One unique feature of γδ T cells is their capacity to become antigen presenting cells [25]. ...
June 2024
Science Immunology
... The maintenance of small intestinal epithelium homeostasis is fundamentally dependent on the function of intestinal stem cells (ISCs) located at the crypt base. Recent studies have extended this understanding by demonstrating that ISCs situated in the upper crypt zone act as a vital reservoir, providing an additional pool of stem cells for regeneration and repair (Capdevila et al. 2024;Malagola et al. 2024). These multipotent ISCs are the origin of differentiated intestinal cells, giving rise to various specialized cell types through a process of expansion and differentiation (Beumer and Clevers 2016). ...
June 2024
Cell
... Transcriptional cell states are informative for modeling and predicting treatment response and resistance on the single-cell level. 13,16,16,30,50,[57][58][59][60][61][62][63] Devising effective therapies requires identification of those states and transcriptional modules specifically, over cell types, are either the most vulnerable to drug treatment or the most essential to tumor integrity. This comprehensive characterization of GBM vulnerabilities across both scRNA-and stRNA-seq data highlights the importance of multimodal approaches to drug discovery. ...
April 2024
Cell Reports
... Recent studies have focused on optimization of in vitro systems that recapitulate disease/lipidassociated microglia/macrophages. These models use iPSC-derived microglia, CNS-relevant substrates, or genetic manipulations of DLAM master transcription factors 19,20,67 . Although they can model human microglia under controlled conditions and offer insights into microglial biology, they also have several caveats. ...
February 2024
... Effector CD4+ and CD8+ T cell subtypes that appear to be more abundant in peripheral blood, cerebrospinal fluid and brains of PD patients are now widely being investigated due to their proinflammatory and cytotoxic profiles (Bhatia et al., 2021;Galiano-Landeira et al., 2020;Jakubiak et al., 2024;Kimura et al., 2024;Lindestam Arlehamn et al., 2020;Schröder et al., 2018;Sulzer et al., 2017;Wang et al., 2021;Williams et al., 2024). Previous findings by our group indeed points to the proliferation of autoreactive CD8+ T cells as a prerequisite for driving late CNS-related pathological process via major histocompatibility class I (MHCI)-mediated antigen presentation by dendritic cells in the spleen (Kazanova et al., 2024;Matheoud et al., 2019;Matheoud et al., 2016). ...
January 2024
... In order to assess whether the tissue imparted distinct gene signatures across lineages, we implemented consensus single cell hierarchical Poisson Factorization (scHPF) 11,35 , a Bayesian factorization algorithm that identifies the major co-expression patterns ("factors") in the data, rather than considering each gene in isolation (as we have done for DE). We applied scHPF to each major immune cell lineage in separate models with balanced cell input across tissues ( Supplementary Table 7 ), which allowed us to identify a variety of transcriptional programs. ...
December 2023
... Moreover, the accumulation of fluorescent protoporphyrins after 5-ALA administration is well documented in non-glial tumours, both inside 61 and outside of the brain 62,63 . Importantly, there is a growing body of work demonstrating that myeloid cells are labelled with PpIX and correlate with PpIX signal intensity 51,64 , which we have confirmed in this study using multiple modalities and internal and external datasets. Bone marrow-derived macrophages increased in concentration in 30 tissue samples with intense PpIX-induced fluorescence 51 . ...
September 2023
Journal of Neurosurgery
... These methods enable the simultaneous acquisition of a large repertoire of single B cell BCRs, specifically the paired CDR3 regions of the heavy (H) and light (L) chains. Utilizing this technology, several research teams have explored age-related B cell subpopulations and their clonality in various tissues, including peritoneal B cells [15], peripheral blood B cells [16], meningeal B cells [17], and B cells in the lungs and lungassociated lymph nodes [18]. ...
July 2023
Nature Immunology