Novel targetable FGFR2 and FGFR3 alterations in glioblastoma associate with aggressive phenotype and distinct gene expression programs

Calcifying pseudoneoplasm of the neuraxis progressing to G5/PDGFRA subgroup glioblastoma in a United States Army veteran with a history of head trauma and germline POT1 and EPHB2 mutations: illustrative case

BACKGROUND

Trauma-associated glioblastoma has been previously described, albeit without molecular characterization.

OBSERVATIONS

The authors show the integrated clinical/pathologic/molecular analysis of a glioblastoma developing 43 years after head trauma sustained by a United States veteran. An epileptogenic benign lesion developed at the trauma site, followed 34 years later by a calcified lesion diagnosed as calcifying pseudoneoplasm of the neuraxis (CAPNON) that recurred 9 years later as glioblastoma with heterotopic/metaplastic ossification. Genomic analysis showed novel germline mutations in the telomere maintenance factor POT1 p.W184* and receptor tyrosine kinase (RTK) EPHB2 p.W792*. The somatic alterations included second-hit POT1 p.D163Y mutation, CDKN2A/2B homozygous loss, DNMT3A mutation and PDGFRA amplification, classifying this glioblastoma in the G5/PDGFRA molecular subgroup. Proliferation markers, PDGFRA, MAPK feedback inhibitors, and EPHB1 showed high expression, whereas EPHB3 and EPHA7 showed the highest expression of all glioblastomas. Following gross-total resection, the patient received adjuvant radiotherapy and temozolomide and died 16.3 months later.

LESSONS

This is the first report of CAPNON progression to glioblastoma and of molecularly characterized glioma occurring decades after head trauma. A multifactorial etiology including genetic predisposition and posttraumatic repair is hypothesized. The discussion presents possible roles of EPH RTKs in posttraumatic repair and CAPNON, and of POT1 and PDGFRα in subsequent progression to glioblastoma. https://thejns.org/doi/10.3171/CASE25152.

Targeting Glioma Stem Cells: Therapeutic Opportunities and Challenges

Glioblastoma (GBM), or grade 4 glioma, is the most common and aggressive primary brain tumor in adults with a median survival of 15 months. Increasing evidence suggests that GBM's aggressiveness, invasiveness, and therapy resistance are driven by glioma stem cells (GSCs), a subpopulation of tumor cells that share molecular and functional characteristics with neural stem cells (NSCs). GSCs are heterogeneous and highly plastic. They evade conventional treatments by shifting their state and entering in quiescence, where they become metabolically inactive and resistant to radiotherapy and chemotherapy. GSCs can exit quiescence and be reactivated to divide into highly proliferative tumor cells which contributes to recurrence. Understanding the molecular mechanisms regulating the biology of GSCs, their plasticity, and the switch between quiescence and mitotic activity is essential to shape new therapeutic strategies. This review examines the latest evidence on GSC biology, their role in glioblastoma progression and recurrence, emerging therapeutic approaches aimed at disrupting their proliferation and survival, and the mechanisms underlying their resistance to therapy.

The landscape of FGFR-TACC fusion in adult glioblastoma: From bench to bedside

Glioblastoma (GBM) is a lethal central nervous system tumor, characterized by extensive genomic alterations and high intra-tumoral heterogeneity. Gene fusions, derived from chromosomal translocations, deletions, and inversions, were increasingly recognized as key carcinogenic events, with the highest frequency of FGFR-TACC fusion in glioblastoma. As reported, FGFR3-TACC3 fusion mostly coexists with wild-type IDH status, and associates with better prognosis. Mechanistically, FGFR3-TACC3 fusions can constitutively activate non-canonical FGFR downstream pathways, induce aneuploidy, and participate in mitochondrial metabolism, thereby promoting cell proliferation and tumorigenesis. These functions, whether based on FGFR3 phosphorylation or not, are predominantly attributed to the specific domain of TACC3 that involved in regulating the localization and activation of fusion products. Several preclinical studies and clinical trials are being performed to evaluate the efficacy and safety of the FGFR-TACC fusion as a personalised therapeutic target, including the treatments with tyrosine kinase inhibitors, metabolic inhibitors, HSP90 inhibitors, coiled-coil peptide-mimetics, and targeted protein degraders. A subset of populations with FGFR-TACC-positive glioblastoma, after refined molecular screening strategies, may benefit from targeted therapies. Despite major progress in biotechnology, our understanding on the role of fusion events in glioblastoma represented by the FGFR-TACC is still in its infancy. Here, we highlight recent progress on FGFR-TACC fusion in human glioblastoma, emphasizing their molecular mechanisms and potential clinical value.

Novel Fibroblast Growth Factor Receptor 3-Fatty Acid Synthase Gene Fusion in Recurrent Epithelioid Glioblastoma Linked to Aggressive Clinical Progression

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults, with a median overall survival (OS) of 15-18 months despite standard treatments. Approximately 8% of GBM cases exhibit genomic alterations in fibroblast growth factor receptors (FGFRs), particularly FGFR1 and FGFR3. Next-generation sequencing techniques have identified various FGFR3 fusions in GBM. This report presents a novel FGFR3 fusion with fatty acid synthase (FASN) in a 41-year-old male diagnosed with GBM. The patient presented with a persistent headache, and imaging revealed a right frontal lobe lesion. Surgical resection and subsequent histopathology confirmed GBM. Initial NGS analysis showed no mutations in the IDH1, IDH2 or H3F3 genes, but revealed a TERT promoter mutation and CDKN2A/2B and PTEN deletions. Postoperative treatment included radiotherapy and temozolomide. Despite initial management, recurrence occurred four months post-diagnosis, confirmed by MRI and histology. A second surgery identified a novel FGFR3-FASN fusion, alongside increased Ki67 expression. The recurrence was managed with regorafenib and bevacizumab, though complications like hand-foot syndrome and radiation necrosis arose. Despite initial improvement, the patient died 15 months after diagnosis. This case underscores the importance of understanding GBM's molecular landscape for effective treatment strategies. The novel FGFR3-FASN fusion suggests potential implications for GBM recurrence and lipid metabolism. Further studies are warranted to explore FGFR3-FASN's role in GBM and its therapeutic targeting.

Practical immunomodulatory landscape of glioblastoma multiforme (GBM) therapy

Glioblastoma multiforme (GBM) is the most common harmful high-grade brain tumor with high mortality and low survival rate. Importantly, besides routine diagnostic and therapeutic methods, modern and useful practical techniques are urgently needed for this serious malignancy. Correspondingly, the translational medicine focusing on genetic and epigenetic profiles of glioblastoma, as well as the immune framework and brain microenvironment, based on these challenging findings, indicates that key clinical interventions include immunotherapy, such as immunoassay, oncolytic viral therapy, and chimeric antigen receptor T (CAR T) cell therapy, which are of great importance in both diagnosis and therapy. Relatively, vaccine therapy reflects the untapped confidence to enhance GBM outcomes. Ongoing advances in immunotherapy, which utilizes different methods to regenerate or modify the resistant body for cancer therapy, have revealed serious results with many different problems and difficulties for patients. Safe checkpoint inhibitors, adoptive cellular treatment, cellular and peptide antibodies, and other innovations give researchers an endless cluster of instruments to plan profoundly in personalized medicine and the potential for combination techniques. In this way, antibodies that block immune checkpoints, particularly those that target the program death 1 (PD-1)/PD-1 (PD-L1) ligand pathway, have improved prognosis in a wide range of diseases. However, its use in combination with chemotherapy, radiation therapy, or monotherapy is ineffective in treating GBM. The purpose of this review is to provide an up-to-date overview of the translational elements concentrating on the immunotherapeutic field of GBM alongside describing the molecular mechanism involved in GBM and related signaling pathways, presenting both historical perspectives and future directions underlying basic and clinical practice.

Clinical features, MRI, molecular alternations, and prognosis of astrocytoma based on WHO 2021 classification of central nervous system tumors: A single-center retrospective study

BACKGROUND

The diagnosis of glioma has advanced since the release of the WHO 2021 classification with more molecular alterations involved in the integrated diagnostic pathways. Our study aimed to present our experience with the clinical features and management of astrocytoma, IDH mutant based on the latest WHO classification.

METHODS

Patients diagnosed with astrocytoma, IDH-mutant based on the WHO 5th edition classification of CNS tumors at our center from January 2009 to January 2022 were included. Patients were divided into WHO 2-3 grade group and WHO 4 grade group. Integrate diagnoses were retrospectively confirmed according to WHO 2016 and 2021 classification. Clinical and MRI characteristics were reviewed, and survival analysis was performed.

RESULTS

A total of 60 patients were enrolled. 21.67% (13/60) of all patients changed tumor grade from WHO 4th edition classification to WHO 5th edition. Of these, 21.43% (6/28) of grade II astrocytoma and 58.33% (7/12) of grade III astrocytoma according to WHO 4th edition classification changed to grade 4 according to WHO 5th edition classification. Sex (p = 0.042), recurrent glioma (p = 0.006), and Ki-67 index (p < 0.001) of pathological examination were statistically different in the WHO grade 2-3 group (n = 27) and WHO grade 4 group (n = 33). CDK6 (p = 0.004), FGFR2 (p = 0.003), and MYC (p = 0.004) alterations showed an enrichment in the WHO grade 4 group. Patients with higher grade showed shorter mOS (mOS = 75.9 m, 53.6 m, 26.4 m for grade 2, 3, and 4, respectively, p = 0.01).

CONCLUSIONS

Patients diagnosed as WHO grade 4 according to the 5th edition WHO classification based on molecular alterations are more likely to have poorer prognosis. Therefore, treatment should be tailored to their individual needs. Further research is needed for the management of IDH-mutant astrocytoma is needed in the future.

FGFR-targeted therapeutics: clinical activity, mechanisms of resistance and new directions

Fibroblast growth factor (FGF) signalling via FGF receptors (FGFR1-4) orchestrates fetal development and contributes to tissue and whole-body homeostasis, but can also promote tumorigenesis. Various agents, including pan-FGFR inhibitors (erdafitinib and futibatinib), FGFR1/2/3 inhibitors (infigratinib and pemigatinib), as well as a range of more-specific agents, have been developed and several have entered clinical use. Erdafitinib is approved for patients with urothelial carcinoma harbouring FGFR2/3 alterations, and futibatinib and pemigatinib are approved for patients with cholangiocarcinoma harbouring FGFR2 fusions and/or rearrangements. Clinical benefit from these agents is in part limited by hyperphosphataemia owing to off-target inhibition of FGFR1 as well as the emergence of resistance mutations in FGFR genes, activation of bypass signalling pathways, concurrent TP53 alterations and possibly epithelial-mesenchymal transition-related isoform switching. The next generation of small-molecule inhibitors, such as lirafugratinib and LOXO-435, and the FGFR2-specific antibody bemarituzumab are expected to have a reduced risk of hyperphosphataemia and the ability to overcome certain resistance mutations. In this Review, we describe the development and current clinical role of FGFR inhibitors and provide perspective on future research directions including expansion of the therapeutic indications for use of FGFR inhibitors, combination of these agents with immune-checkpoint inhibitors and the application of novel technologies, such as artificial intelligence.

Translation into Clinical Practice of the G1-G7 Molecular Subgroup Classification of Glioblastoma: Comprehensive Demographic and Molecular Pathway Profiling

Glioblastoma is the most frequent and malignant primary neoplasm of the central nervous system. In a recent breakthrough study on a prospective Discovery cohort, I proposed the first all-inclusive molecular classification of glioblastoma into seven subgroups, G1-G7, based on MAPK pathway activation. New data from a WHO-grade-4 diffuse glioma prospective Validation cohort offers, in this study, an integrated demographic-molecular analysis of a 213-patient Combined cohort. Despite cohort differences in the median age and molecular subgroup distribution, all the prospectively-acquired cases from the Validation cohort mapped into one of the G1-G7 subgroups defined in the Discovery cohort. A younger age of onset, higher tumor mutation burden and expanded G1/EGFR-mutant and G3/NF1 glioblastoma subgroups characterized the glioblastomas from African American/Black relative to Caucasian/White patients. The three largest molecular subgroups were G1/EGFR, G3/NF1 and G7/Other. The fourth largest subgroup, G6/Multi-RTK, was detailed by describing a novel gene fusion ST7-MET, rare PTPRZ1-MET, LMNA-NTRK1 and GOPC-ROS1 fusions and their overexpression mechanisms in glioblastoma. The correlations between the MAPK pathway G1-G7 subgroups and the PI3-kinase/PTEN, TERT, cell cycle G1 phase and p53 pathways defined characteristic subgroup pathway profiles amenable to personalized targeted therapy. This analysis validated the first all-inclusive molecular classification of glioblastoma, showed significant demographic and molecular differences between subgroups, and provided the first ethnic molecular comparison of glioblastoma.

Adult glioblastoma with Lynch syndrome-associated mismatch repair deficiency forms a distinct high-risk molecular subgroup

Glioblastoma is the most frequent and malignant primary brain tumor. Although the survival is generally dismal for glioblastoma patients, risk stratification and the identification of high-risk subgroups is important for prompt and aggressive management. The G1-G7 molecular subgroup classification based on the MAPK pathway activation has offered for the first time a non-redundant, all-inclusive classification of adult glioblastoma. Five patients from the large, 218-patient, prospective cohort showed germline mutations in mismatch repair (MMR) genes (Lynch syndrome) and a significantly worse median survival of 3.25 months post-surgery than those from the G1/EGFR and G3/NF1 major subgroups, or from the rest of the cohort adjusted for age. These rare tumors were assigned to a new subgroup, G3/MMR, a G3/NF1 subgroup spin-off, as they generally show genomic alterations leading to RAS activation, such as NF1 and PTPN11 mutations. An integrated clinical, histologic and molecular analysis of the G3/MMR tumors showed distinct characteristics as compared to other glioblastomas, including those with iatrogenic high tumor mutation burden (TMB), warranting a separate subgroup. Prior history of cancer, midline location or multifocality, presence of multinucleated giant cells (MGCs), positive p53 and MMR immunohistochemistry, and specific molecular characteristics, including high TMB, MSH2/MSH6 alterations, biallelic TP53 Arg mutations and co-occurring PIK3CA p.R88Q and PTEN alterations, alert to this high-risk G3/MMR subgroup. The MGCs and p53 immunohistochemistry analysis in G1-G7 subgroups showed that one in 7 tumors with these characteristics is a G3/MMR glioblastoma. The FDA-approved first-line therapy for many advanced solid tumors consists of nivolumab-ipilimumab immune checkpoint inhibitors. One G3/MMR patient received this regimen and survived much longer than the rest, setting a proof-of-principle example for the treatment of these very aggressive G3/MMR glioblastomas.

From signalling pathways to targeted therapies: unravelling glioblastoma's secrets and harnessing two decades of progress

Glioblastoma, a rare, and highly lethal form of brain cancer, poses significant challenges in terms of therapeutic resistance, and poor survival rates for both adult and paediatric patients alike. Despite advancements in brain cancer research driven by a technological revolution, translating our understanding of glioblastoma pathogenesis into improved clinical outcomes remains a critical unmet need. This review emphasises the intricate role of receptor tyrosine kinase signalling pathways, epigenetic mechanisms, and metabolic functions in glioblastoma tumourigenesis and therapeutic resistance. We also discuss the extensive efforts over the past two decades that have explored targeted therapies against these pathways. Emerging therapeutic approaches, such as antibody-toxin conjugates or CAR T cell therapies, offer potential by specifically targeting proteins on the glioblastoma cell surface. Combination strategies incorporating protein-targeted therapy and immune-based therapies demonstrate great promise for future clinical research. Moreover, gaining insights into the role of cell-of-origin in glioblastoma treatment response holds the potential to advance precision medicine approaches. Addressing these challenges is crucial to improving outcomes for glioblastoma patients and moving towards more effective precision therapies.

SPRY4-dependent ERK negative feedback demarcates functional adult stem cells in the male mouse germline†

Niche-derived growth factors support self-renewal of mouse spermatogonial stem and progenitor cells through ERK MAPK signaling and other pathways. At the same time, dysregulated growth factor-dependent signaling has been associated with loss of stem cell activity and aberrant differentiation. We hypothesized that growth factor signaling through the ERK MAPK pathway in spermatogonial stem cells is tightly regulated within a narrow range through distinct intracellular negative feedback regulators. Evaluation of candidate extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK)-responsive genes known to dampen downstream signaling revealed robust induction of specific negative feedback regulators, including Spry4, in cultured mouse spermatogonial stem cells in response to glial cell line-derived neurotrophic factor or fibroblast growth factor 2. Undifferentiated spermatogonia in vivo exhibited high levels of Spry4 mRNA. Quantitative single-cell analysis of ERK MAPK signaling in spermatogonial stem cell cultures revealed both dynamic signaling patterns in response to growth factors and disruption of such effects when Spry4 was ablated, due to dysregulation of ERK MAPK downstream of RAS. Whereas negative feedback regulator expression decreased during differentiation, loss of Spry4 shifted cell fate toward early differentiation with concomitant loss of stem cell activity. Finally, a mouse Spry4 reporter line revealed that the adult spermatogonial stem cell population in vivo is demarcated by strong Spry4 promoter activity. Collectively, our data suggest that negative feedback-dependent regulation of ERK MAPK is critical for preservation of spermatogonial stem cell fate within the mammalian testis.

Leptomeningeal neuraxis relapse in glioblastoma is an uncommon but not rare event associated with poor outcome

BACKGROUND

Spinal neuraxis leptomeningeal metastasis (LM) relapse in glioblastoma is an uncommon event that is challenging to manage. This study aims to determine the incidence, associated factors, and outcome of LM relapse in patients with glioblastoma managed with radical intent.

METHODS

Patients managed for glioblastoma using the EORTC-NCIC (Stupp) Protocol from 2007 to 2019 were entered into a prospective ethics-approved database. Follow-up included routine cranial MRI surveillance with further imaging as clinically indicated. LM relapse was determined by MRI findings and/or cerebrospinal fluid analysis. The chi-square test of independence was used to evaluate clinico-pathologic factors associated with increased risk of subsequent LM relapse. Median survival post-LM relapse was calculated using Kaplan-Meier technique.

RESULTS

Four-hundred-and-seven patients were eligible, with median follow-up of 60 months for surviving patients. Eleven (2.7%) had LM at first relapse and in total 21 (5.1%) experienced LM in the entire follow-up period. Sites of LM relapse were 8 (38%) focal spinal, 2 (10%) focal brainstem medulla and 11 (52%) diffuse spinal. Median overall survival from initial diagnosis for the entire cohort was 17.6 months (95% CI 16.7-19.0). Median survival from LM relapse to death was 39 days (95% CI: 19-107). Factors associated with LM relapse were age less than 50 years (p < 0.01), initial disease located in the temporal lobe (p < 0.01) and tumours lacking MGMT promoter methylation (p < 0.01).

CONCLUSIONS

LM relapse is an uncommon but not rare event in patients managed radically for glioblastoma. It is associated with poor outcome with the majority of patients deceased within two months of recognition.

An unusual presentation of bilateral optic pathway glioma in Crouzon Syndrome

Crouzon Syndrome is a genetic craniosynostosis disorder associated with a high risk of ophthalmologic sequelae secondary to structural causes. However, ophthalmologic disorders due to intrinsic nerve aberrations in Crouzon Syndrome have not been described. Optic pathway gliomas (OPGs) are low grade gliomas that are intrinsic to the visual pathway, frequently associated with Neurofibromatosis type 1 (NF-1). OPGs involving both optic nerves without affecting the optic chiasm are rarely seen outside of NF-1. We report an unusual case of bilateral optic nerve glioma without chiasmatic involvement in a 17-month-old male patient with Crouzon Syndrome without any clinical or genetic findings of NF-1. This case suggests that close ophthalmologic follow up and orbital MRIs may benefit patients with Crouzon Syndrome.

FGFR2 upregulates PAI-1 via JAK2/STAT3 signaling to induce M2 polarization of macrophages in colorectal cancer

Fibroblast growth factor receptor 2 (FGFR2) is frequently activated by overexpression or mutation, and an abnormal fibroblast growth factor (FGF)/FGFR signaling pathway is associated with the occurrence, development, and poor prognosis of colorectal cancer (CRC). Our preliminary analysis found that plasminogen activator inhibitor-1 (PAI-1) expression may be related to FGF/FGFR signaling, however, their role in the tumor immune microenvironment remains unclear. In this study, we observed markedly higher PAI-1 expression in CRC patients with poor survival rates. PAI-1 is regulated by FGF/FGFR2 in colon cancer cells and is involved in M2 macrophage polarization. Mechanistically, inhibiting the JAK2/STAT3 signaling pathway could cause PAI-1 downregulation. Furthermore, the activation of phosphorylated STAT3 upregulated PAI-1. In vivo, FGFR2 overexpression in tumor-bearing mouse models suggested that a PAI-1 inhibitor could rescue FGFR2/PAI-1 axis-induced M2 macrophage polarization, which leads to effective immune activity and tumor suppression. Moreover, the combination of a PAI-1 inhibitor and anti-PD-1 therapy exhibited superior antitumor activity in mice. These findings offer novel insights into the molecular mechanisms underlying tumor deterioration and provide potential therapeutic targets for CRC treatment.

Deep proteome investigation of high-grade gliomas reveals heterogeneity driving differential metabolism of 5-aminolevulinic acid

Background

Fluorescence-guided surgery (FGS) using 5-aminolevulinic acid (5-ALA) as adjunct for high-grade gliomas (HGGs) has been on the rise in recent years. Despite being largely effective, we observed multiple histologically similar sub-regions of the same tumor from a few individuals with varying protoporphyrin IX (PpIX) levels. The current study aims at understanding the proteomic changes driving differential metabolism of 5-ALA in HGGs.

Methods

Biopsies were histologically and biochemically assayed. Following this, a deep proteomics investigation was carried out using high resolution liquid chromatography-mass spectrometry (HR LC-MS) to identify protein expression in differentially fluorescing regions of HGGs.

Results

Our analysis identified 5437 proteins with high confidence. Differential analysis in the subgroup with HGGs carrying IDH mutation (IDH mt.) revealed 93 differentially regulated proteins (raw p-value ≤ 0.05 and absolute FC ≥ 1.5). Similar analysis in the IDH wild type (IDH wt.) subgroup revealed 20 differentially regulated proteins. Gene set enrichment analysis (GSEA) identified key pathways like ion channel transport, trafficking of AMPA receptors, and regulation of heme-oxygenase-1 in the IDH wt. subgroup. Pathways such as scavenging of heme, signaling by NOTCH4, negative regulation of PI3-AKT pathway, and iron uptake and transport were observed to be differentially regulated in the IDH mt. subgroup.

Conclusions

Tumor regions from the same patient exhibiting differential fluorescence following 5-ALA administration were observed to have different proteome profiles. Future studies aimed at a better molecular understanding of 5-ALA metabolism in HGGs hold the potential to increase the efficacy of FGS and the use of 5-ALA as a theragnostic tool.

Integrative Multi-OMICs Identifies Therapeutic Response Biomarkers and Confirms Fidelity of Clinically Annotated, Serially Passaged Patient-Derived Xenografts Established from Primary and Metastatic Pediatric and AYA Solid Tumors

Establishment of clinically annotated, molecularly characterized, patient-derived xenografts (PDXs) from treatment-naïve and pretreated patients provides a platform to test precision genomics-guided therapies. An integrated multi-OMICS pipeline was developed to identify cancer-associated pathways and evaluate stability of molecular signatures in a panel of pediatric and AYA PDXs following serial passaging in mice. Original solid tumor samples and their corresponding PDXs were evaluated by whole-genome sequencing, RNA-seq, immunoblotting, pathway enrichment analyses, and the drug−gene interaction database to identify as well as cross-validate actionable targets in patients with sarcomas or Wilms tumors. While some divergence between original tumor and the respective PDX was evident, majority of alterations were not functionally impactful, and oncogenic pathway activation was maintained following serial passaging. CDK4/6 and BETs were prioritized as biomarkers of therapeutic response in osteosarcoma PDXs with pertinent molecular signatures. Inhibition of CDK4/6 or BETs decreased osteosarcoma PDX growth (two-way ANOVA, p < 0.05) confirming mechanistic involvement in growth. Linking patient treatment history with molecular and efficacy data in PDX will provide a strong rationale for targeted therapy and improve our understanding of which therapy is most beneficial in patients at diagnosis and in those already exposed to therapy.

Infiltrating gliomas with FGFR alterations: Histologic features, genetic alterations, and potential clinical implications

BACKGROUND

Fibroblast growth factor receptors (FGFRs) are frequently altered in cancers and present a potential therapeutic avenue. However, the type and prevalence of FGFR alterations in infiltrating gliomas (IGs) needs further investigation.

OBJECTIVE

To understand the prevalence/type of FGFR alterations in IGs.

METHODS

We reviewed clinicopathologic and genomic alterations of FGFR-mutant gliomas in a cohort of 387 patients. Tumors were examined by DNA next-generation sequencing for somatic mutations with a panel interrogating 205-genes. For comparison, cBioPortal databases were queried to identify FGFR-altered IGs.

RESULTS

Fourteen patients (3.6%) with FGFR-mutant tumors were identified including 11 glioblastomas, Isocitrate dehydrogenase (IDH) - wildtype (GBM-IDH-WT), 2 oligodendrogliomas, and 1 astrocytoma IDH-mutant. FGFR-altered IGs showed endocrinoid capillaries, microvascular proliferation, necrosis, oligodendroglioma-like cells, fibrin thrombi, microcalcifications, and nodular growth. FGFR3 was the most commonly altered FGFR gene (64.3%). The most common additional mutations in FGFR-altered IGs were TERTp, CDKN2A/B, PTEN, CDK4, MDM2, and TP53. FGFR3 alterations were only observed in GBM-IDH-WT. EGFR alterations were rarely identified in FGFR3-altered gliomas.

CONCLUSIONS

Histologic features correlate with FGFR alterations in IGs. FGFR3-TACC3 fusion and FGFR3 amplification are the most common FGFR alterations in IGs. FGFR alterations are a rare, but potentially viable, therapeutic target in asubset of IGs.

Identification of potential target genes of honokiol in overcoming breast cancer resistance to tamoxifen

Background

Honokiol (HON) inhibits epidermal growth factor receptor (EGFR) signaling and increases the activity of erlotinib, an EGFR inhibitor, in human head and neck cancers. In this study, using a bioinformatics approach and in vitro experiments, we assessed the target genes of HON against breast cancer resistance to tamoxifen (TAM).

Materials and methods

Microarray data were obtained from GSE67916 and GSE85871 datasets to identify differentially expressed genes (DEGs). DEGs common between HON-treated and TAM-resistant cells were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and protein-protein interaction (PPI) networks were constructed. Selected genes were analyzed for genetic alterations, expression, prognostic value, and receiver operating characteristics (ROC). TAM-resistant MCF-7 (MCF-7 TAM-R) cells were generated and characterized for their resistance toward TAM. A combination of HON and TAM was used for cytotoxicity and gene expression analyses. Molecular docking was performed using the Molecular Operating Environment software.

Results

PPI network analysis revealed that FN1, FGFR2, and RET were the top three genes with the highest scores. A genetic alteration study of potential target genes revealed MMP16 and ERBB4 as the genes with the highest alterations among the breast cancer samples. Pathway enrichment analysis of FGFR2, RET, ERBB4, SOX2, FN1, and MMP16 showed that the genetic alterations herein were likely to impact the RTK-Ras pathway. The expression levels of RET, MMP16, and SOX2 were strongly correlated with prognostic power, with areas under the ROC curves (AUC) ​​of 1, 0.8, and 0.8, respectively. The HON and TAM combination increased TAM cytotoxicity in MCF-7 TAM-R cells by regulating the expression of potential target genes ret, ERBB4, SOX2, and FN1, as well as the TAM resistance regulatory genes including HES1, VIM, PCNA, TP53, and CASP7. Molecular docking results indicated that HON tended to bind RET, ErbB4, and the receptor protein Notch1 ankyrin domain more robustly than its native ligand.

Conclusion

HON could overcome breast cancer resistance to TAM, potentially by targeting FGFR2, RET, ERBB4, MMP16, FN1, and SOX2. However, further studies are required to validate these results.

New Directions in the Therapy of Glioblastoma

Glioblastoma is the most common histologic type of all gliomas and contributes to 57.3% of all cases. Despite the standard management based on surgical resection and radiotherapy, it is related to poor outcome, with a 5-year relative survival rate below 6.9%. In order to improve the overall outcome for patients, the new therapeutic strategies are needed. Herein, we describe the current state of knowledge on novel targeted therapies in glioblastoma. Based on recent studies, we compared treatment efficacy measured by overall survival and progression-free survival in patients treated with selected potential antitumor drugs. The results of the application of the analyzed inhibitors are highly variable despite the encouraging conclusions of previous preclinical studies. This paper focused on drugs that target major glioblastoma kinases. As far, the results of some BRAF inhibitors are favorable. Vemurafenib demonstrated a long-term efficacy in clinical trials while the combination of dabrafenib and trametinib improves PFS compared with both vemurafenib and dabrafenib alone. There is no evidence that any MEK inhibitor is effective in monotherapy. According to the current state of knowledge, BRAF and MEK inhibition are more advantageous than BRAF inhibitor monotherapy. Moreover, mTOR inhibitors (especially paxalisib) may be considered a particularly important group. Everolimus demonstrated a partial response in a significant proportion of patients when combined with bevacizumab, however its actual role in the treatment is unclear. Neither nintedanib nor pemigatinib were efficient in treatment of GBM. Among the anti-VEGF drugs, bevacizumab monotherapy was a well-tolerated option, significantly associated with anti-GBM activity in patients with recurrent GBM. The efficacy of aflibercept and pazopanib in monotherapy has not been demonstrated. Apatinib has been proven to be effective and tolerable by a single clinical trial, but more research is needed. Lenvatinib is under trial. Finally, promising results from a study with regorafenib may be confirmed by the ongoing randomized AGILE trial. The studies conducted so far have provided a relatively wide range of drugs, which are at least well tolerated and demonstrated some efficacy in the randomized clinical trials. The comprehensive understanding of the molecular biology of gliomas promises to further improve the treatment outcomes of patients.

Glioblastoma CD105+ cells define a SOX2- cancer stem cell-like subpopulation in the pre-invasive niche

Glioblastoma (GBM) is the most common and most aggressive primary brain tumor in adults. Glioma stem like cells (GSC) represent the highest cellular hierarchy in GBM and have a determining role in tumor growth, recurrence and patient prognosis. However, a better definition of GSC subpopulations, especially at the surgical resection margin, is warranted for improved oncological treatment options. The present study interrogated cells expressing CD105 (CD105+) specifically within the tumor front and the pre-invasive niche as a potential GSC subpopulation. GBM primary cell lines were generated from patients (n = 18) and CD105+ cells were isolated and assessed for stem-like characteristics. In vitro, CD105+ cells proliferated and enriched in serum-containing medium but not in serum-free conditions. CD105+ cells were characterized by Nestin+, Vimentin+ and SOX2-, clearly distinguishing them from SOX2+ GCS. GBM CD105+ cells differentiated into osteocytes and adipocytes but not chondrocytes. Exome sequencing revealed that GBM CD105+ cells matched 83% of somatic mutations in the Cancer cell line encyclopedia, indicating a malignant phenotype and in vivo xenotransplantation assays verified their tumorigenic potential. Cytokine assays showed that immunosuppressive and protumorigenic cytokines such as IL6, IL8, CCL2, CXCL-1 were produced by CD105+ cells. Finally, screening for 88 clinical drugs revealed that GBM CD105+ cells are resistant to most chemotherapeutics except Doxorubicin, Idarubicin, Fludarabine and ABT-751. Our study provides a rationale for targeting tumoral CD105+ cells in order to reshape the tumor microenvironment and block GBM progression.

Novel neoplasms associated with syndromic pediatric medulloblastoma: integrated pathway delineation for personalized therapy

Medulloblastoma is the most common pediatric embryonal brain tumor, and may occur in cancer predisposition syndromes. We describe novel associations of medulloblastoma with atypical prolactinoma and dural high-grade sarcoma in Li-Fraumeni syndrome (LFS), and epidural desmoid fibromatosis in familial adenomatous polyposis (FAP)/Turcot syndrome. Genomic analysis showing XRCC3 alterations suggested radiotherapy as contributing factor to the progression of LFS-associated medulloblastoma, and demonstrated different mechanisms of APC inactivation in the FAP-associated tumors. The integrated genomic-transcriptomic analysis uncovered the growth pathways driving tumorigenesis, including the prolactin-prolactin receptor (PRLR) autocrine loop and Shh pathway in the LFS-associated prolactinoma and medulloblastoma, respectively, the Wnt pathway in both FAP-associated neoplasms, and the TGFβ and Hippo pathways in the soft tissue tumors, regardless of germline predisposition. In addition, the comparative analysis of paired syndromic neoplasms revealed several growth pathways susceptible to therapeutic intervention by PARP, PRLR, and selective receptor tyrosine kinase (RTK) inhibitors. These could target the defective DNA damage repair in the LFS-associated medulloblastoma, the prolactin autocrine loop in the atypical prolactinoma, the EPHA3/7 and ALK overexpression in the FAP-associated medulloblastoma, and the multi-RTK upregulation in the soft tissue neoplasms. This study presents the spatiotemporal evolution of novel neoplastic associations in syndromic medulloblastoma, and discusses the post-radiotherapy risk for secondary malignancies in syndromic pediatric patients, with important implications for the biology, diagnosis, and therapy of these tumors. Video Abstract.

FGFR3-TACCs3 Fusions and Their Clinical Relevance in Human Glioblastoma

Oncogenic fusion genes have emerged as successful targets in several malignancies, such as chronic myeloid leukemia and lung cancer. Fusion of the fibroblast growth receptor 3 and the transforming acidic coiled coil containing protein—FGFR3-TACC3 fusion—is prevalent in 3–4% of human glioblastoma. The fusion protein leads to the constitutively activated kinase signaling of FGFR3 and thereby promotes cell proliferation and tumor progression. The subgroup of FGFR3-TACC3 fusion-positive glioblastomas presents with recurrent clinical and histomolecular characteristics, defining a distinctive subtype of IDH-wildtype glioblastoma. This review aims to provide an overview of the available literature on FGFR3-TACC3 fusions in glioblastoma and possible implications for actual clinical practice.

PLOD2 Is a Prognostic Marker in Glioblastoma That Modulates the Immune Microenvironment and Tumor Progression

This study aimed to investigate the role of Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase 2 (PLOD2) in glioblastoma (GBM) pathophysiology. To this end, PLOD2 protein expression was assessed by immunohistochemistry in two independent cohorts of patients with primary GBM (n1 = 204 and n2 = 203, respectively). Association with the outcome was tested by Kaplan−Meier, log-rank and multivariate Cox regression analysis in patients with confirmed IDH wild-type status. The biological effects and downstream mechanisms of PLOD2 were assessed in stable PLOD2 knock-down GBM cell lines. High levels of PLOD2 significantly associated with (p1 = 0.020; p2< 0.001; log-rank) and predicted (cohort 1: HR = 1.401, CI [95%] = 1.009−1.946, p1 = 0.044; cohort 2: HR = 1.493; CI [95%] = 1.042−2.140, p2 = 0.029; Cox regression) the poor overall survival of GBM patients. PLOD2 knock-down inhibited tumor proliferation, invasion and anchorage-independent growth. MT1-MMP, CD44, CD99, Catenin D1 and MMP2 were downstream of PLOD2 in GBM cells. GBM cells produced soluble factors via PLOD2, which subsequently induced neutrophils to acquire a pro-tumor phenotype characterized by prolonged survival and the release of MMP9. Importantly, GBM patients with synchronous high levels of PLOD2 and neutrophil infiltration had significantly worse overall survival (p < 0.001; log-rank) compared to the other groups of GBM patients. These findings indicate that PLOD2 promotes GBM progression and might be a useful therapeutic target in this type of cancer.

Glioblastoma multiforme targeted delivery of docetaxel using bevacizumab-modified nanostructured lipid carriers impair in vitro cell growth and in vivo tumor progression

Glioblastoma multiforme (GBM) is the most common malignant brain cancer, characterized by high invasiveness and poor prognosis. Docetaxel (DTX) is a chemotherapeutic drug with promising anti-tumor properties. However, conventional intravenous formulations exhibit side effects of systemic biodistribution and low brain bioavailability, limiting their clinical use. The current work aimed to evaluate the effect of DTX-loaded nanostructured lipid carriers (NLC) functionalized with bevacizumab (BVZ-NLC-DTX) against GBM using in vitro and in vivo models. The NLC was obtained by the fusion-emulsification method followed by sonication, with narrow size distribution, negative zeta potential, and low polydispersity index. NLC showed DTX entrapment efficiency above 90%. BVZ coupling efficiency was 62% and BVZ integrity after functionalization was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Calorimetry studies confirmed thermal stability and molecular dispersion of DTX in the lipid matrix. NLC showed a sustained DTX release over 84 h. In vitro anti-tumor assays shown that BVZ-NLC-DTX selectively increased the cytotoxic of DTX in cells overexpressing VEGF (U87MG and A172), but not in peripheral blood mononuclear cells (PMBCs), promoting cell death by apoptosis. BVZ functionalization did not impair cellular uptake. An in vivo orthotopic rat model demonstrated that free-DTX was not capable of reducing tumor growth whereas BVZ-NLC-DTX reduced up to 70% tumor volume after 15-days of treatment. Therefore, this study contributes to understanding new nanotechnology-based vehicles capable of reaching the brain more efficiently and repurposing the use of anti-cancer drugs in GBM treatment.

Case Report: Identification of Multiple TERT and FGFR2 Gene Fusions in a Pineal Region Glioblastoma Case

As an oncogenic somatic variant, telomerase reverse transcriptase promoter (TERTp) mutations are frequently observed in adult glioblastoma (GBM). Alternatively, we report the first case of glioblastoma with TERT amplification accompanied by multiple TERT and FGFR2 gene fusions instead of TERTp mutation. A 55-year-old woman presented with dizziness, headache, and diplopia for three weeks. Magnetic resonance imaging (MRI) demonstrated a heterogeneously enhancing lobulated mass centered in the pineal region. Partial tumor resection and ventriculoperitoneal shunt were achieved, and the residual tumor was then treated with standard radiation. The tumor was diagnosed as GBM, IDH-wild type, WHO grade IV, and the Ki67 proliferation index was high (30–40%). Intriguingly, TERT amplification without TERTp mutation was identified via next generation sequencing (NGS). Further analysis revealed multiple TERT (TERT–NUBPL, MARCH6–TERT, and CJD4–TERT) and FGFR2 (CXCL17–FGFR2, SIPA1L3–FGFR2, FGFR2–SIPA1L3, and FGFR2–CEACAM1) gene fusions. After the surgery, the patient’s condition deteriorated rapidly due to the malignant nature of the tumor and she died with an overall survival of 3 months. Our report provides the molecular clue for a novel telomerase activation and maintenance mechanism in GBM.

Tyrosine Kinase Inhibitors in Adult Glioblastoma: An (Un)Closed Chapter?

Glioblastoma (GBM) is the most common and lethal form of malignant brain tumor. GBM patients normally undergo surgery plus adjuvant radiotherapy followed by chemotherapy. Numerous studies into the molecular events driving GBM highlight the central role played by the Epidermal Growth Factor Receptor (EGFR), as well as the Platelet-derived Growth Factor Receptors PDGFRA and PDGFRB in tumor initiation and progression. Despite strong preclinical evidence for the therapeutic potential of tyrosine kinase inhibitors (TKIs) that target EGFR, PDGFRs, and other tyrosine kinases, clinical trials performed during the last 20 years have not led to the desired therapeutic breakthrough for GBM patients. While clinical trials are still ongoing, in the medical community there is the perception of TKIs as a lost opportunity in the fight against GBM. In this article, we review the scientific rationale for the use of TKIs targeting glioma drivers. We critically analyze the potential causes for the failure of TKIs in the treatment of GBM, and we propose alternative approaches to the clinical evaluation of TKIs in GBM patients.

Down-regulation of MYH10 driven by chromosome 17p13.1 deletion promotes hepatocellular carcinoma metastasis through activation of the EGFR pathway

Somatic copy number alterations (CNAs) are a genomic hallmark of cancers. Among them, the chromosome 17p13.1 deletions are recurrent in hepatocellular carcinoma (HCC). Here, utilizing an integrative omics analysis, we screened out a novel tumour suppressor gene within 17p13.1, myosin heavy chain 10 (MYH10). We observed frequent deletions (~38%) and significant down‐regulation of MYH10 in primary HCC tissues. Deletion or decreased expression of MYH10 was a potential indicator of poor outcomes in HCC patients. Knockdown of MYH10 significantly promotes HCC cell migration and invasion in vitro, and overexpression of MYH10 exhibits opposite effects. Further, inhibition of MYH10 markedly potentiates HCC metastasis in vivo. We preliminarily elucidated the mechanism by which loss of MYH10 promotes HCC metastasis by facilitating EGFR pathway activation. In conclusion, our study suggests that MYH10, a candidate target gene for 17p13 deletion, acts as a tumour suppressor and may serve as a potential prognostic indicator for HCC patients.

Profiling Receptor Tyrosine Kinase Fusions in Chinese Breast Cancers

Background

Receptor tyrosine kinases (RTKs) are a class of tyrosine kinases that regulate cell-to-cell communication and control a variety of complex biological functions. Dysregulation of RTK signaling partly due to chromosomal rearrangements leads to novel tyrosine kinase fusion oncoproteins that are possibly driver alterations to cancers. Targeting some RTK fusions with specific tyrosine kinases inhibitors (TKIs) is an effective therapeutic strategy across a spectrum of RTK fusion-related cancers. However, there is still a paucity of extensive RTK fusion investigations in breast cancer. This study aims to characterize RTK fusions in Chinese breast cancer patients.

Methods

An in-house DNA sequencing database of 1440 Chinese breast cancer patients with a capture-based panel (520 gene or 108 gene-panel) was thoroughly reviewed. A total of 2,229 samples including 1,045 tissues and 1,184 plasmas were analyzed. RTK fusion was defined as an in-frame fusion with the tyrosine kinase domain of the RTK completely retained. Concomitant mutations were also analyzed and tumor mutational burden (TMB) was calculated. Patients' clinical characteristics were retrieved from case records.

Results

A total of 30 RTK fusion events were identified from 27 breast cancer patients with a prevalence of 1.875%%. FGFR2 fusions were seen the most commonly (n=7), followed by RET (n=5), ROS1 (n=3), NTRK3 (n=3), BRAF (n=2), and NTRK1 (n=2). Other RTK fusions including ALK, EGFR, FGFR1, FGFR3, MET, and NTRK2 were identified in one patient each. A total of 27 unique resultant fusion proteins (22 with a novel partner) were discovered including 19 intrachromosomal rearrangements and 8 interchromosomal ones. Twenty-one fusions had the tyrosine kinase domain in-frame fused with a partner gene and six were juxtaposed with an intergenic space. Among the 27 fusions, FGFR2-WDR11 (E17: intergenic) (n=3) and ETV6-NTRK3 (E5:E15) (n=2) occurred recurrently. Of note, the normalized abundance of RTK fusion (fusion AF/max AF) correlated negatively with TMB (r=-0.48, P=0.017). Patients with TMB < 8 (Mutations/Mb) displayed a higher fusion abundance than those with TMB ≥ 8 (Mutations/Mb) (P=0.025). Moreover, CREBBP mutation only co-occurred with FGFR2 fusion (P=0.012), while NTRK3 fusion and TP53 mutation were mutually exclusive (P=0.019).

Conclusion

This is the first study comprehensively delineating the prevalence and spectrum of RTK fusions in Chinese breast cancers. Further study is ongoing to identify the enriched subpopulation who may benefit from RTK fusion inhibitors.

Multi-Platform Classification of IDH-Wild-Type Glioblastoma Based on ERK/MAPK Pathway: Diagnostic, Prognostic and Therapeutic Implications

Glioblastoma is the most aggressive and frequent glioma in the adult population. Because current therapy regimens confer only minimal survival benefit, molecular subgrouping to stratify patient prognosis and therapy design is warranted. This study presents a multi-platform classification of glioblastoma by analyzing a large, ethnicity-inclusive 101-adult-patient cohort. It defines seven non-redundant IDH-wild-type glioblastoma molecular subgroups, G1-G7, corresponding to the upstream receptor tyrosine kinase (RTK) and RAS-RAF segment of the ERK/MAPK signal transduction pathway. These glioblastoma molecular subgroups are classified as G1/EGFR, G2/FGFR3, G3/NF1, G4/RAF, G5/PDGFRA, G6/Multi-RTK, and G7/Other. The comprehensive genomic analysis was refined by expression landscaping of all RTK genes, as well as of the major associated growth pathway mediators, and used to hierarchically cluster the subgroups. Parallel demographic, clinical, and histologic pattern analyses were merged with the molecular subgrouping to yield the first inclusive multi-platform classification for IDH-wild-type glioblastoma. This straightforward classification with diagnostic and prognostic significance may be readily used in neuro-oncological practice and lays the foundation for personalized targeted therapy approaches.