Publications by authors named "Kroonen J"

Background: Cellular immunotherapy using modified T cells offers new avenues for cancer treatment. T-cell receptor (TCR) engineering of CD8 T cells enables these cells to recognize tumor-associated antigens and tumor-specific neoantigens. Improving TCR T-cell therapy through increased potency and in vivo persistence will be critical for clinical success.

View Article and Find Full Text PDF

Combination therapies targeting malignancies aim to increase treatment efficacy and reduce toxicity. Hypomethylating drug 5-Aza-2'-deoxycytidine (5-Aza-2') enhances transcription of tumor suppressor genes and induces replication errors via entrapment of DNMT1, yielding DNA-protein crosslinks. Post-translational modification by SUMO plays major roles in the DNA damage response and is required for degradation of entrapped DNMT1.

View Article and Find Full Text PDF

Objective: Pancreatic ductal adenocarcinoma (PDAC) has the characteristics of high-density desmoplastic stroma, a distinctive immunosuppressive microenvironment and is profoundly resistant to all forms of chemotherapy and immunotherapy, leading to a 5-year survival rate of 9%. Our study aims to add novel small molecule therapeutics for the treatment of PDAC.

Design: We have studied whether TAK-981, a novel highly selective and potent small molecule inhibitor of the small ubiquitin like modifier (SUMO) activating enzyme E1 could be used to treat a preclinical syngeneic PDAC mouse model and we have studied the mode of action of TAK-981.

View Article and Find Full Text PDF

Multiple components of the SUMOylation machinery are deregulated in various cancers and could represent potential therapeutic targets. Understanding the role of SUMOylation in tumor progression and aggressiveness would increase our insight in the role of SUMO in cancer and clarify its potential as a therapeutic target. Here we investigate SUMO in relation to conventional chondrosarcomas, which are malignant cartilage forming tumors of the bone.

View Article and Find Full Text PDF

The anaphase-promoting complex/cyclosome (APC/C) is an E3 ubiquitin ligase that controls cell cycle transitions. Its regulation by the spindle assembly checkpoint (SAC) is coordinated with the attachment of sister chromatids to the mitotic spindle. APC/C SUMOylation on APC4 ensures timely anaphase onset and chromosome segregation.

View Article and Find Full Text PDF

The small ubiquitin-like modifier (SUMO) signaling cascade is critical for gene expression, genome integrity, and cell cycle progression. In this review, we discuss the important role SUMO may play in cancer and how to target SUMO signaling. Recently developed small molecule inhibitors enable therapeutic targeting of the SUMOylation pathway.

View Article and Find Full Text PDF

Background: The antiepileptic drug valproic acid (VPA) inhibits histone deacetylase in glioblastoma cells in vitro, which influences several oncogenic pathways and decreases glioma cell proliferation. The clinical relevance of these observations remains unclear, as VPA does not seem to affect glioblastoma patient survival. In this study, we analyzed whether the in vitro effects of VPA treatment on histone acetylation are also observed in tumor tissues of glioblastoma patients.

View Article and Find Full Text PDF

Prostate cancer (PCa) is defined by dysregulated lipid signaling and is characterized by upregulation of lipid metabolism-related genes including fatty acid binding protein 5 (FABP5), fatty acid synthase (FASN), and monoacylglycerol lipase (MAGL). FASN and MAGL are enzymes that generate cellular fatty acid pools while FABP5 is an intracellular chaperone that delivers fatty acids to nuclear receptors to enhance PCa metastasis. Since FABP5, FASN, and MAGL have been independently implicated in PCa progression, we hypothesized that FABP5 represents a central mechanism linking cytosolic lipid metabolism to pro-metastatic nuclear receptor signaling.

View Article and Find Full Text PDF

Introduction: The subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma.

Methods: We analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors.

View Article and Find Full Text PDF

With the progression towards personalised and age-appropriate medicines, the production of drug loaded liposomes at the point of care would be highly desirable. In particular, liposomal solubilisation agents that can be produced rapidly and easily would provide a new option in personalised medicines. Such a process could also be used as a rapid tool for the formulation and pre-clinical screening of low soluble drugs.

View Article and Find Full Text PDF

An analytical procedure to measure the whole-body uptake of pharmaceuticals in zebrafish has been developed using state-of-the-art methodologies. A sample preparation procedure for 9 pharmaceuticals displaying a variety in physicochemical properties was developed using 10-day old zebrafish (TG898). For an efficient homogenization of the samples and subsequent recovery of the compounds of interest, different amounts of organic solvents in combination with acidic modifiers were added to zebrafish samples.

View Article and Find Full Text PDF

Background: Patients with glioblastoma (GBM) have an overall median survival of 15 months despite multimodal therapy. These catastrophic survival rates are to be correlated to systematic relapses that might arise from remaining glioblastoma stem cells (GSCs) left behind after surgery. In this line, it has recently been demonstrated that GSCs are able to escape the tumor mass and preferentially colonize the adult subventricular zone (SVZ).

View Article and Find Full Text PDF

Casein kinase II contributes to the growth and survival of malignant gliomas and attracts increasing attention as a therapeutic target in these tumors. Several reports have suggested that this strategy might be most relevant for specific subgroups of patients, namely Verhaak's classical and TP53 wild-type tumors. Using kinase assays and microarray genetic profiling in a series of 27 proprietary fresh frozen surgical glioma samples, we showed that constitutive CK2 kinase activation is not restricted to tumors that present increased copy numbers or mRNA expression of its catalytic or regulatory subunits, and can result from a functional activation by various cytokines from the glioma microenvironment.

View Article and Find Full Text PDF

Background: Epileptogenic glioblastomas are thought to convey a favorable prognosis, either due to early diagnosis or potential antitumor effects of antiepileptic drugs. We investigated the relationship between survival and epilepsy at presentation, early diagnosis, and antiepileptic drug therapy in glioblastoma patients.

Methods: Multivariable Cox regression was applied to survival data of 647 consecutive patients diagnosed with de novo glioblastoma between 2005 and 2013 in order to investigate the association between epilepsy and survival in glioblastoma patients.

View Article and Find Full Text PDF

Glioblastoma multiforme (GBM) is the most common primary brain tumor and is without exception lethal. GBMs modify the immune system, which contributes to the aggressive nature of the disease. Particularly, cells of the monocytic lineage, including monocytes, macrophages and microglia, are affected.

View Article and Find Full Text PDF

Osteopontin (OPN) is a secreted protein involved in most aspects of tumor progression and metastasis development. Elevated OPN expression has been reported in multiple types of cancer including glioblastoma (GBM), the highest grade and most aggressive brain tumor. GBMs contain a subpopulation of glioma-initiating cells (GICs) implicated in progression, therapeutic resistance and recurrence.

View Article and Find Full Text PDF

Background: Glioblastomas remain ominous tumors that almost invariably escape treatment. Connexins are a family of transmembrane, gap junction-forming proteins, some members of which were reported to act as tumor suppressors and to modulate cellular metabolism in response to cytotoxic stress.

Methods: We analyzed the copy number and expression of the connexin (Cx)30 gene gap junction beta-6 (GJB6), as well as of its protein immunoreactivity in several public and proprietary repositories of glioblastomas, and their influence on patient survival.

View Article and Find Full Text PDF

Background: Patients with glioblastoma multiforme (GBM) have an overall median survival of 15 months. This catastrophic survival rate is the consequence of systematic relapses that could arise from remaining glioblastoma stem cells (GSCs) left behind after surgery. We previously demonstrated that GSCs are able to escape the tumor mass and specifically colonize the adult subventricular zones (SVZs) after transplantation.

View Article and Find Full Text PDF

Aims: Human cytomegalovirus (HCMV) is a ubiquitous beta human herpesvirus able to influence infected cell survival and proliferation and to modulate the host immune response. As there is accumulating evidence that HCMV is detected in primary intracranial astrocytic tumours, in this study we looked for the presence of HCMV in intracranial tumours and tried to correlate this eventual presence with the anti-HCMV systemic immunoreactivity and with the detection of HCMV in peripheral blood.

Methods: In this study, we analysed 43 glioblastomas (GBM), 14 oligodendrogliomas (OL) and 20 meningiomas (MG) by immunofluorescence (IF) targeting HCMV immediate early antigen (IE1) and by nested PCR (nPCR) amplifying HCMV glycoprotein B (gB).

View Article and Find Full Text PDF

Glioblastoma multiforme (GBM, WHO grade IV) is the most common and lethal subtype of primary brain tumor with a median overall survival of 15 months from the time of diagnosis. The presence in GBM of a cancer population displaying neural stem cell (NSC) properties as well as tumor-initiating abilities and resistance to current therapies suggests that these glioblastoma-initiating cells (GICs) play a central role in tumor development and are closely related to NSCs. However, it is nowadays still unclear whether GICs derive from NSCs, neural progenitor cells or differentiated cells such as astrocytes or oligodendrocytes.

View Article and Find Full Text PDF

Aims: Synaptic vesicle proteins 2 (SV2) are neuronal vesicles membrane glycoproteins that appear as important targets in the treatment of partial and generalized epilepsies. Therefore, we analysed the expression of SV2 isoforms in the hippocampus of patients with temporal lobe epilepsy (TLE).

Methods: SV2A, SV2B and SV2C immunostaining and QuantiGene branched DNA assay were performed on biopsies from 31 consecutive TLE patients with mesial temporal sclerosis (MTS) and compared with 10 autopsy controls.

View Article and Find Full Text PDF

Inhibitors of casein kinase 2 (CK2), a regulator of cell proliferation and mediator of the DNA damage response, are being evaluated in clinical trials for the treatment of cancers. Apigenin was capable of inhibiting the activation of CK2 following γ irradiation in LN18 and U87 malignant glioma cells. Apigenin and siRNA-mediated CK2 protein depletion further inhibited NF-κB activation and altered the Tyr68 phosphorylation of Chk2 kinase, a DNA damage response checkpoint kinase, following irradiation.

View Article and Find Full Text PDF

Background: Multiple choroid plexus papillomas (CPPs) are rare. Usually, they correspond to villous hypertrophy or metastasis occurring during cerebrospinal dissemination. Multiple CPPs have rarely been reported as synchronous tumors.

View Article and Find Full Text PDF

In patients with glioblastoma multiforme, recurrence is the rule despite continuous advances in surgery, radiotherapy and chemotherapy. Within these malignant gliomas, glioblastoma stem cells or initiating cells have been recently described, and they were shown to be specifically involved in experimental tumorigenesis. In this study, we show that some human glioblastoma cells injected into the striatum of immunodeficient nude mice exhibit a tropism for the subventricular zones.

View Article and Find Full Text PDF

Among patients which develop glioblastoma multiform (GBM), recurrence is the rule despite continuous progress in surgery, radiotherapy and chemotherapy. In the adult, GBM is the most frequent and most aggressive tumour of the Central Nervous System. A better understanding of the mechanisms by which these tumours relapse could promote the use of preventive therapy and could increase patients' survival.

View Article and Find Full Text PDF