Plasmodium falciparum erythrocyte membrane protein 1 variants induce cell swelling and disrupt the blood-brain barrier in cerebral malaria.

Cerebral malaria (CM) is caused by the binding of Plasmodium falciparum-infected erythrocytes (IEs) to the brain microvasculature, leading to inflammation, vessel occlusion, and cerebral swelling. We have previously linked dual intercellular adhesion molecule-1 (ICAM-1)- and endothelial protein C receptor (EPCR)-binding P. falciparum parasites to these symptoms, but the mechanism driving the pathogenesis has not been identified. Here, we used a 3D spheroid model of the blood-brain barrier (BBB) to determine unexpected new features of IEs expressing the dual-receptor binding PfEMP1 parasite proteins. Analysis of multiple parasite lines shows that IEs are taken up by brain endothelial cells in an ICAM-1-dependent manner, resulting in breakdown of the BBB and swelling of the endothelial cells. Via ex vivo analysis of postmortem tissue samples from CM patients, we confirmed the presence of parasites within brain endothelial cells. Importantly, this discovery points to parasite ingress into the brain endothelium as a contributing factor to the pathology of human CM

Familial alzheimer’s disease lymphocytes respond differently than sporadic cells to oxidative stress: upregulated p53-p21 signaling linked with presenilin 1 mutants

16 p.-7 fig.-2 tab.Familial (FAD) and sporadic (SAD) Alzheimer's disease do not share all pathomechanisms, but knowledge on their molecular differences is limited. We previously reported that cell cycle control distinguishes lymphocytes from SAD and FAD patients. Significant differences were found in p21 levels of SAD compared to FAD lymphocytes. Since p21 can also regulate apoptosis, the aim of this study was to compare the response of FAD and SAD lymphocytes to oxidative stress like 2-deoxy-D-ribose (2dRib) treatment and to investigate the role of p21 levels in this response. We report that FAD cells bearing seven different PS1 mutations are more resistant to 2dRib-induced cell death than control or SAD cells: FAD cells showed a lower apoptosis rate and a lower depolarization of the mitochondrial membrane. Despite that basal p21 cellular content was lower in FAD than in SAD cells, in response to 2dRib, p21 mRNA and protein levels significantly increased in FAD cells. Moreover, we found a higher cytosolic accumulation of p21 in FAD cells. The transcriptional activation of p21 was shown to be dependent on p53, as it can be blocked by PFT-α, and correlated with the increased phosphorylation of p53 at Serine 15. Our results suggest that in FAD lymphocytes, the p53-mediated increase in p21 transcription, together with a shift in the nucleocytoplasmic localization of p21, confers a survival advantage against 2dRib-induced apoptosis. This compensatory mechanism is absent in SAD cells. Thus, therapeutic and diagnostic designs should take into account possible differential apoptotic responses in SAD versus FAD cells.This research was supported by the Joint Programming for Neurodegenerative Diseases (JPND) grant 2/BIOMARKAPD/JPND/2012 and the Polish National Science Centre grant NN401 596840 to UW, and by the Spanish Ministry of Economy and Competitiveness (CTQ-2015-66313-R) to AM-RPeer reviewe

A New Inhibitor of Tubulin Polymerization Kills Multiple Cancer Cell Types and Reveals p21-Mediated Mechanism Determining Cell Death after Mitotic Catastrophe

Induction of mitotic catastrophe through the disruption of microtubules is an established target in cancer therapy. However, the molecular mechanisms determining the mitotic catastrophe and the following apoptotic or non-apoptotic cell death remain poorly understood. Moreover, many existing drugs targeting tubulin, such as vincristine, have reduced efficacy, resulting from poor solubility in physiological conditions. Here, we introduce a novel small molecule 2-aminoimidazoline derivative—OAT-449, a synthetic water-soluble tubulin inhibitor. OAT-449 in a concentration range from 6 to 30 nM causes cell death of eight different cancer cell lines in vitro, and significantly inhibits tumor development in such xenograft models as HT-29 (colorectal adenocarcinoma) and SK-N-MC (neuroepithelioma) in vivo. Mechanistic studies showed that OAT-449, like vincristine, inhibited tubulin polymerization and induced profound multi-nucleation and mitotic catastrophe in cancer cells. HeLa and HT-29 cells within 24 h of treatment arrested in G2/M cell cycle phase, presenting mitotic catastrophe features, and 24 h later died by non-apoptotic cell death. In HT-29 cells, both agents altered phosphorylation status of Cdk1 and of spindle assembly checkpoint proteins NuMa and Aurora B, while G2/M arrest and apoptosis blocking was consistent with p53-independent accumulation in the nucleus and largely in the cytoplasm of p21/waf1/cip1, a key determinant of cell fate programs. This is the first common mechanism for the two microtubule-dissociating agents, vincristine and OAT-449, determining the cell death pathway following mitotic catastrophe demonstrated in HT-29 cells

Uncovering transcriptomic landscape alterations of CAN-2409 in in vitro and in vivo glioma models

RationaleCAN-2409 is a locally delivered oncolytic therapy, which results in vaccination against the injected tumor. CAN-2409 consists of a non-replicating adenovirus armed with the Herpes virus thymidine kinase, which metabolizes ganciclovir into a phosphorylated nucleotide that is incorporated into the tumor cell’s genome, thereby inflicting immunogenic cancer cell death. While CAN-2409’s immunological impact has been well characterized, its effects on the tumor cells transcriptome remains unknown. We compared the transcriptomic landscape after treatment of glioblastoma models with CAN-2409 in vitro and in vivo to assess how the interplay with the tumor microenvironment influences CAN-2409-mediated transcriptome alterations.MethodsWe performed RNA-Seq with CAN-2409 treated patient-derived glioma stem-like cells and tumors of C57/BL6 mice and compared KEGG pathway usage and differential gene expression focusing on immune cell and cytokine profiles. T-cell -killing assays were performed to assess candidate effectors.ResultsPCA analysis showed distinct clustering of control and CAN-2409 samples under both conditions. KEGG pathway analysis revealed significant enrichment for p53 signaling and cell cycle pathway, with similar dynamics for key regulators of both pathways in vitro and in vivo, including MYC, CCNB1, PLK1 and CDC20. Selected alterations (PLK1 and CCNB1) were validated at the protein level. Cytokine expression analysis revealed upregulation of pro-inflammatory IL12a under both conditions; immune cell gene profiling showed reduction of myeloid associated genes. T-cell-killing assays showed increased killing in the presence of IL-12.ConclusionCAN-2409 significantly alters the transcriptome both in vitro and in vivo. Comparison of pathway enrichment revealed mutual and differential utilization of pathways under both conditions, suggesting a modulating influence on the cell cycle in tumor cells, and of the tumor microenvironment on the transcriptome in vivo. IL-12 synthesis likely depends on interactions with the tumor microenvironment, and it facilitates CAN-2409 cell killing. This dataset provides potential to understand resistance mechanisms and identify potential biomarkers for future studies

Cytomegalovirus promotes murine glioblastoma growth via pericyte recruitment and angiogenesis.

Cytomegalovirus (CMV) has been implicated in glioblastoma (GBM); however, a mechanistic connection in vivo has not been established. The purpose of this study is to characterize the effects of murine CMV (MCMV) on GBM growth in murine models. Syngeneic GBM models were established in mice perinatally infected with MCMV. We found that tumor growth was markedly enhanced in MCMV+ mice, with a significant reduction in overall survival compared with that of controls (P \u3c 0.001). We observed increased angiogenesis and tumor blood flow in MCMV+ mice. MCMV reactivation was observed in intratumoral perivascular pericytes and tumor cells in mouse and human GBM specimens, and pericyte coverage of tumor vasculature was strikingly augmented in MCMV+ mice. We identified PDGF-D as a CMV-induced factor essential for pericyte recruitment, angiogenesis, and tumor growth. The antiviral drug cidofovir improved survival in MCMV+ mice, inhibiting MCMV reactivation, PDGF-D expression, pericyte recruitment, and tumor angiogenesis. These data show that MCMV potentiates GBM growth in vivo by increased pericyte recruitment and angiogenesis due to alterations in the secretome of CMV-infected cells. Our model provides evidence for a role of CMV in GBM growth and supports the application of antiviral approaches for GBM therapy

Tumor Interferon Signaling Is Regulated by a lncRNA INCR1 Transcribed from the PD-L1 Locus

Tumor interferon (IFN) signaling promotes PD-L1 expression to suppress T cell-mediated immunosurveillance. We identify the IFN-stimulated non-coding RNA 1 (INCR1) as a long noncoding RNA (lncRNA) transcribed from the PD-L1 locus and show that INCR1 controls IFN gamma signaling in multiple tumor types. Silencing INCR1 decreases the expression of PD-L1, JAK2, and several other IFN gamma-stimulated genes. INCR1 knockdown sensitizes tumor cells to cytotoxic T cell-mediated killing, improving CAR T cell therapy. We discover that PD-L1 and JAK2 transcripts are negatively regulated by binding to HNRNPH1, a nuclear ribonucleoprotein. The primary transcript of INCR1 binds HNRNPH1 to block its inhibitory effects on the neighboring genes PD-L1 and JAK2, enabling their expression. These findings introduce a mechanism of tumor IFN gamma signaling regulation mediated by the lncRNA INCR1 and suggest a therapeutic target for cancer immunotherapy

Targeting Glioblastoma Using a Novel Peptide Specific to a Deglycosylated Isoform of Brevican

Glioblastoma (GBM) is the most common and deadliest form of brain tumor and remains amongst the most difficult cancers to treat. Brevican (Bcan), a central nervous system (CNS)-specific extracellular matrix protein, is upregulated in high-grade glioma cells, including GBM. A Bcan isoform lacking most glycosylation, dg-Bcan, is found only in GBM tissues. Here, dg-Bcan is explored as a molecular target for GBM. In this study, a d-peptide library is screened to identify a small 8-amino acid dg-Bcan-Targeting Peptide (BTP) candidate, called BTP-7 that binds dg-Bcan with high affinity and specificity. BTP-7 is preferentially internalized by dg-Bcan-expressing patient-derived GBM cells. To demonstrate GBM targeting, BTP-7 is radiolabeled with 18F, a radioisotope of fluorine, and increased radiotracer accumulation is found in intracranial GBM established in mice using positron emission tomography (PET) imaging. dg-Bcan is an attractive molecular target for GBM, and BTP-7 represents a promising lead candidate for further development into novel imaging agents and targeted therapeutics