Histone demethylase Jumonji D3 (JMJD3) as a tumor suppressor by regulating p53 protein nuclear stabilization.

Histone methylation regulates normal stem cell fate decisions through a coordinated interplay between histone methyltransferases and demethylases at lineage specific genes. Malignant transformation is associated with aberrant accumulation of repressive histone modifications, such as polycomb mediated histone 3 lysine 27 (H3K27me3) resulting in a histone methylation mediated block to differentiation. The relevance, however, of histone demethylases in cancer remains less clear. We report that JMJD3, a H3K27me3 demethylase, is induced during differentiation of glioblastoma stem cells (GSCs), where it promotes a differentiation-like phenotype via chromatin dependent (INK4A/ARF locus activation) and chromatin independent (nuclear p53 protein stabilization) mechanisms. Our findings indicate that deregulation of JMJD3 may contribute to gliomagenesis via inhibition of the p53 pathway resulting in a block to terminal differentiation

Identification of molecular pathways facilitating glioma cell invasion in situ.

Gliomas are mostly incurable secondary to their diffuse infiltrative nature. Thus, specific therapeutic targeting of invasive glioma cells is an attractive concept. As cells exit the tumor mass and infiltrate brain parenchyma, they closely interact with a changing micro-environmental landscape that sustains tumor cell invasion. In this study, we used a unique microarray profiling approach on a human glioma stem cell (GSC) xenograft model to explore gene expression changes in situ in Invading Glioma Cells (IGCs) compared to tumor core, as well as changes in host cells residing within the infiltrated microenvironment relative to the unaffected cortex. IGCs were found to have reduced expression of genes within the extracellular matrix compartment, and genes involved in cell adhesion, cell polarity and epithelial to mesenchymal transition (EMT) processes. The infiltrated microenvironment showed activation of wound repair and tissue remodeling networks. We confirmed by protein analysis the downregulation of EMT and polarity related genes such as CD44 and PARD3 in IGCs, and EFNB3, a tissue-remodeling agent enriched at the infiltrated microenvironment. OLIG2, a proliferation regulator and glioma progenitor cell marker upregulated in IGCs was found to function in enhancing migration and stemness of GSCs. Overall, our results unveiled a more comprehensive picture of the complex and dynamic cell autonomous and tumor-host interactive pathways of glioma invasion than has been previously demonstrated. This suggests targeting of multiple pathways at the junction of invading tumor and microenvironment as a viable option for glioma therapy

Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Abstract Background Corticosteroids are routinely utilized to alleviate edema in patients with intracranial lesions and are first-line agents to combat immune-related adverse events (irAEs) that arise with immune checkpoint blockade treatment. However, it is not known if or when corticosteroids can be administered without abrogating the efforts of immunotherapy. The purpose of this study was to evaluate the impact of dexamethasone on lymphocyte activation and proliferation during checkpoint blockade to provide guidance for corticosteroid use while immunotherapy is being implemented as a cancer treatment. Methods Lymphocyte proliferation, differentiation, and cytokine production were evaluated during dexamethasone exposure. Human T cells were stimulated through CD3 ligation and co-stimulated either directly by CD28 ligation or by providing CD80, a shared ligand for CD28 and CTLA-4. CTLA-4 signaling was inhibited by antibody blockade using ipilimumab which has been approved for the treatment of several solid tumors. The in vivo effects of dexamethasone during checkpoint blockade were evaluated using the GL261 syngeneic mouse intracranial model, and immune populations were profiled by flow cytometry. Results Dexamethasone upregulated CTLA-4 mRNA and protein in CD4 and CD8 T cells and blocked CD28-mediated cell cycle entry and differentiation. Naïve T cells were most sensitive, leading to a decrease of the development of more differentiated subsets. Resistance to dexamethasone was conferred by blocking CTLA-4 or providing strong CD28 co-stimulation prior to dexamethasone exposure. CTLA-4 blockade increased IFNγ expression, but not IL-2, in stimulated human peripheral blood T cells exposed to dexamethasone. Finally, we found that CTLA-4 blockade partially rescued T cell numbers in mice bearing intracranial gliomas. CTLA-4 blockade was associated with increased IFNγ-producing tumor-infiltrating T cells and extended survival of dexamethasone-treated mice. Conclusions Dexamethasone-mediated T cell suppression diminishes naïve T cell proliferation and differentiation by attenuating the CD28 co-stimulatory pathway. However, CTLA-4, but not PD-1 blockade can partially prevent some of the inhibitory effects of dexamethasone on the immune response

Additional file 1: of Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Figure S1. T cell stimulated with αCD3/αCD28 microbeads proliferate in the presence of dexamethasone.Healthy donor T cells were cultured for four days with the indicated ratio of αCD3/αCD28 microbeads:total T cells in the presence of vehicle or dexamethasone. A, Representative flow cytometry plots of CellTrace violet dilution. Plots were derived from gated CD4 (top row) or CD8 (bottom row) T cells. B-D, Proliferation analyses of CD4 T cells (top) and CD8 T cells (bottom) performed on the samples shown in (A). Precursor Frequency (B), Expansion Index (C), and Proliferation Index (D) are shown. Samples were plated in duplicate and analyzed with an unpaired students T test. Data are representative of three independent experiments. (PDF 3563 kb

On Patterns of Neuropsychiatric Symptoms in Patients With COVID-19: A Systematic Review of Case Reports.

Coronavirus disease 2019 (COVID-19) has various neuropsychiatric manifestations, including psychotic, mood, anxiety disorders, trauma-related disorders, and cognitive disorders, such as delirium. Although the psychosocial effects of the COVID-19 pandemic contribute to an increase in psychiatric comorbidities, the COVID-19 virus is also an independent risk factor. Previous studies have revealed that the virus can invade the neural tissue, which causes an imbalance of neurotransmitters that cause neuropsychiatric symptoms. The aim of this article is to conduct a systematic review to determine the patterns of neuropsychiatric manifestations of COVID-19, discussing the frequency and its impact on pre-existing psychiatric disorders. Thirty-nine case reports were collected and analyzed for a systematic review. They were full-text, peer-reviewed journal publications from November 2020 to February 2021. Fifty-three patients were included in our study. The most frequent symptom was abnormal/bizarre behavior (50.9%), followed by agitation/aggression (49.1%), and the third most common was altered mental status and delirium (47.2%). Only 48% of our patients had a pre-existing psychiatric disorder, including three not formally diagnosed but displayed psychiatric symptoms prior to the COVID-19 infection. Findings suggest a positive correlation of new-onset psychiatric symptoms with the SARS-CoV-2 virus. However, the exact pathophysiology of the virus itself causing neuropsychiatric manifestations needs to be investigated further

Additional file 3: of Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Figure S3. T cell differentiation subsets formed during in vitro stimulation with ιCD3/CD80 stimulation. Negatively-selected healthy donor T cells were cultured with 5 Οg/mL ιCD3 and the indicated concentration of CD80. T cell differentiation subsets were quantified following four days of culture. A, Flow plot of gating strategy to identify the indicated T cell differentiation subsets. B, Flow plots of CD4 (top) and CD8 (bottom) T cells cultured under the indicated conditions. (PDF 3995 kb

Additional file 4: of Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Figure S4. Increased co-stimulation ameliorates the inhibitory effects of dexamethasone. Negatively-selected healthy donor T cells were cultured with 5 μg/mL αCD3 and increasing concentrations of CD80 in the presence of vehicle or dexamethasone. A-B. CD8 T cells cultured with vehicle (A) or dexamethasone (B). Flow cytometry plots showing proliferation of cells cultured with the indicated concentration of CD80 (left) and total numbers of naïve (TN), central memory (TCM), effector memory (TEM), and terminal effector (TTE) T cells following four days of culture (right) are shown. Differentiation subsets were assessed by CD45RO and CCR7 staining. Each condition was plated in duplicate, and data are representative of three independent experiments. Data were analyzed with an unpaired, two-tailed T Test. (PDF 2573 kb

Additional file 5: of Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Figure S5 PD-1 blockade does not rescue dexamethasone-mediated proliferation defects. A, Flow cytometry analysis of PD-1 surface expression on CD4 (left) or CD8 (right) T cells stimulated with αCD3/αCD28 microbeads. Unstimulated (dashed line), stimulated in presence of vehicle (solid line), and stimulated in presence of dexamethasone (filled red line) are shown. B, Geometric median fluorescence intensity (gMFI) of PD-1 staining on CD4 or CD8 T cells. Cells cultured with vehicle (black bars) and dexamethasone (red bars) are shown. Data are an average of duplicate samples. C, Expression of PD-1 by qPCR of T cells stimulated in the presence of vehicle or dexamethasone. Data are representative of four independent experiments. D-E. Healthy donor T cells were stimulated for four days in the presence of vehicle or dexamethasone and nivolumab or ipilimumab F(ab’)2 antibody as indicated. Precursor frequency of CD4 and CD8 T cells was quantified by FlowJo. The ratio of dexamethasone to vehicle for CD4 (C) and CD8 (D) T cells is shown. All samples were plated in duplicate and the ratios were analyzed with a one-way ANOVA. Data are representative of n = 4 healthy donors. (PDF 2522 kb

Additional file 7: of Dexamethasone-induced immunosuppression: mechanisms and implications for immunotherapy

Figure S7. Quantification of Treg and checkpoint molecules in tumor-bearing mice. GL261 ffluc-mCherry tumor-bearing mice were randomized into the indicated cohorts based on bioluminescence values from tumor. Vehicle or dexamethasone treatment was initiated on day 7, and isotype or CTLA-4 blocking antibody were administered on days 13, 16, and 19 following tumor implantation. Mice were euthanized on day 23 and tissues were harvested for flow cytometry analysis. A, Treg cell number from tumor-bearing brain hemisphere (left; n = 8) or the cervical tumor-draining lymph nodes (right; n = 10). B, The percentage of CD4 (top two plots) or CD8 (bottom two plots) T cells expressing the indicated checkpoint molecules. Co-expression of molecules was quantified using a Boolean gating strategy. Data were analyzed using a unpaired students T test. (PDF 1891 kb