Context: Insulin-like 3 and its receptor, leucine-rich repeat-containing G protein-coupled receptor 8 (LGR8), are essential for the first phase of testicular descent. Homozygous loss of either of the two genes in mice leads to cryptorchidism. Although mutations in both homologous human genes are not a common cause of cryptorchidism. To date, only one missense mutation at codon 222 (T222P) of the LGR8 gene has been proposed as a causative mutation for cryptorchidism. This conclusion was based on both functional in vitro studies and the lack of mutation in a large group of controls. The geographical origin of the mutation carriers suggested a founder effect in the Mediterranean area. Objectives: We sought to define the frequency of the T222P mutation in four different countries to assess whether the screening for this mutation could be of use as a diagnostic genetic test. Materials and Methods: A total of 822 subjects (359 with a history of cryptorchidism and 463 controls) from Italy, Spain, Hungary, and Egypt were genotyped for the T222P mutation by direct sequencing. Results: The phenotypical expression of the mutation also included normal testicular descent. The mutation frequency was not significantly different in cryptorchid patients vs. noncryptorchid controls (3.6 vs. 1.7%, respectively). No significant geographical differences were observed in mutation frequencies. The haplotype analysis allowed us to predict three distinct haplotypes, i.e. three possible mutation events. Conclusions: Our results suggest that the T222P mutation cannot be considered either causative or a susceptibility factor for cryptorchidism. A true causative mutation in the LGR8 gene still remains to be identified.
Glioblastoma is a highly malignant brain tumor with no curative treatment options, and immune checkpoint blockade has not yet shown major impact. We hypothesized that drugs targeting mitosis might affect the tumor microenvironment and sensitize cancer cells to immunotherapy. We used 2 glioblastoma mouse models with different immunogenicity profiles, GL261 and SB28, to test the efficacy of antineoplastic and immunotherapy combinations. The spindle assembly checkpoint activator BAL101553 (lisavanbulin), agonistic anti-CD40 antibody, and double immune checkpoint blockade (anti-programmed cell death 1 and anti-cytotoxic T lymphocyte-associated protein 4; anti-PD-1 and anti-CTLA-4) were evaluated individually or in combination for treating orthotopic GL261 and SB28 tumors. Genomic and immunological analyses were used to predict and interpret therapy responsiveness. BAL101553 monotherapy increased survival in immune checkpoint blockade-resistant SB28 glioblastoma tumors and synergized with anti-CD40 antibody, in a T cell-independent manner. In contrast, the more immunogenic and highly mutated GL261 model responded best to anti-PD-1 and anti-CTLA-4 therapy and more modestly to BAL101553 and anti-CD40 combination. Our results show that BAL101553 is a promising therapeutic agent for glioblastoma and could synergize with innate immune stimulation. Overall, these data strongly support immune profiling of glioblastoma patients and preclinical testing of combination therapies with appropriate models for particular patient groups.
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor, characterized by a high degree of intertumoral heterogeneity. However, a common feature of the GBM microenvironment is hypoxia, which can promote radio- and chemotherapy resistance, immunosuppression, angiogenesis, and stemness. We experimentally defined common GBM adaptations to physiologically relevant oxygen gradients, and we assessed their modulation by the metabolic drug metformin. We directly exposed human GBM cell lines to hypoxia (1% O2) and to physioxia (5% O2). We then performed transcriptional profiling and compared our in vitro findings to predicted hypoxic areas in vivo using in silico analyses. We observed a heterogenous hypoxia response, but also a common gene signature that was induced by a physiologically relevant change in oxygenation from 5% O2 to 1% O2. In silico analyses showed that this hypoxia signature was highly correlated with a perinecrotic localization in GBM tumors, expression of certain glycolytic and immune-related genes, and poor prognosis of GBM patients. Metformin treatment of GBM cell lines under hypoxia and physioxia reduced viable cell number, oxygen consumption rate, and partially reversed the hypoxia gene signature, supporting further exploration of targeting tumor metabolism as a treatment component for hypoxic GBM.
Abstract Glioblastoma (GBM) is a deadly and the most common primary brain tumor in adults. Due to their regulation of a high number of mRNA transcripts, microRNAs (miRNAs) are key molecules in the control of biological processes and are thereby promising therapeutic targets for GBM patients. In this regard, we recently reported miRNAs as strong modulators of GBM aggressiveness. Here, using an integrative and comprehensive analysis of the TCGA database and the transcriptome of GBM biopsies, we identified three critical and clinically relevant miRNAs for GBM, miR-17-3p, miR-222, and miR-340. In addition, we showed that the combinatorial modulation of three of these miRNAs efficiently inhibited several biological processes in patient-derived GBM cells of all these three GBM subtypes (Mesenchymal, Proneural, Classical), induced cell death, and delayed tumor growth in a mouse tumor model. Finally, in a doxycycline-inducible model, we observed a significant inhibition of GBM stem cell viability and a significant delay of orthotopic tumor growth. Collectively, our results reveal, for the first time, the potential of miR-17-3p, miR-222 and miR-340 multi-targeting as a promising therapeutic strategy for GBM patients.
Abstract The great success of chimeric antigen receptor (CAR)-T cell therapy in B-cell malignancies has prompted its translation to solid tumors. In the case of glioblastoma (GBM), clinical trials have shown modest efficacy, but anti-GBM CAR-T cells are being intensely developed. In this study, we selected PTPRZ1 as an attractive new target for GBM treatment. We isolated six anti-human PTPRZ1 scFv from a human phage display library and produced 2 nd generation CAR-T cells in an RNA format. Patient-derived GBM PTPRZ1-knock-in cell lines were used to select the CAR construct (471_28z), which showed high cytotoxicity while consistently displaying high CAR expression. CAR-T cells incorporating 471_28z were able to release IFN-γ, IL-2, TNF-α, Granzyme B, IL-17A, IL-6, and soluble FasL, and displayed low tonic signaling. Additionally, they maintained an effector memory phenotype after in vitro killing. Importantly, 471_28z CAR-T cells displayed strong bystander killing against PTPRZ1-negative cell lines after pre-activation by PTPRZ1-positive tumor cells, but did not kill antigen-negative non-tumor cells. In an orthotopic xenograft tumor model using NSG mice, a single dose of anti-PTPRZ1 CAR-T cells significantly delayed tumor growth. Taken together, these results validate the use of PTPRZ1 as a new GBM target and prompt the use of anti-PTPRZ1 CAR-T cells for clinical translation.
<div>Abstract<p>The great success of chimeric antigen receptor (CAR) T-cell therapy in the treatment of patients with B-cell malignancies has prompted its translation to solid tumors. In the case of glioblastoma (GBM), clinical trials have shown modest efficacy, but efforts to develop more effective anti-GBM CAR T cells are ongoing. In this study, we selected protein tyrosine phosphatase receptor type Z (PTPRZ1) as a target for GBM treatment. We isolated six anti-human PTPRZ1 single-chain variable fragments from a human phage display library and produced second-generation CAR T cells in an RNA format. Patient-derived GBM PTPRZ1–knockin cell lines were used to select the CAR construct that showed high cytotoxicity while consistently displaying high CAR expression (471_28z). CAR T cells incorporating 471_28z were able to release IFNγ, IL2, TNFα, granzyme B, IL17A, IL6, and soluble FasL and displayed low tonic signaling. Additionally, they maintained an effector memory phenotype after <i>in vitro</i> killing. In addition, 471_28z CAR T cells displayed strong bystander killing against PTPRZ1-negative cell lines after preactivation by PTPRZ1-positive tumor cells but did not kill antigen-negative nontumor cells. In an orthotopic xenograft tumor model using NOD/SCIDγ mice, a single dose of anti-PTPRZ1 CAR T cells significantly delayed tumor growth. Taken together, these results validate PTPRZ1 as a GBM target and prompt the clinical translation of anti-PTPRZ1 CAR T cells.</p></div>
High-grade glioma (HGG) rarely spreads outside the CNS. To test the hypothesis that the lesions were metastases originating from an HGG, we sequenced the relapsing HGG and distant extraneural lesions.We performed whole-exome sequencing of an HGG lesion, its local relapse, and distant lesions in bone and lymph nodes.Phylogenetic reconstruction and histopathologic analysis confirmed the common glioma origin of the secondary lesions. The mutational profile revealed an IDH1/2 wild-type HGG with an activating mutation in EGFR and biallelic focal loss of CDKN2A (9p21). In the metastatic samples and the local relapse, we found an activating PIK3CA mutation, further copy number gains in chromosome 7 (EGFR), and a putative pathogenic driver mutation in a canonical splice site of FLNA.Our findings demonstrate tumor spread outside the CNS and identify potential genetic drivers of metastatic dissemination outside the CNS, which could be leveraged as therapeutic targets or potential biomarkers.
