Identification of targets for rational pharmacological therapy in childhood craniopharyngioma

Recurrent adamantinomatous craniopharyngioma stabilized with tocilizumab and bevacizumab: illustrative case

BACKGROUND

Adamantinomatous craniopharyngiomas (ACPs) are slow-growing, cystic, highly morbid central nervous system tumors located adjacent to vital structures including the pituitary, hypothalamus, and optic chiasm. Tumor recurrence is common. Treatment relies on resection with or without adjuvant radiation and is highly individualized. Targeted chemotherapies have not been routinely used in the treatment of ACPs.

OBSERVATIONS

The authors present the case of an adult patient with recurrent ACP that was clinically and radiologically stabilized with a combination of bevacizumab and tocilizumab every 3 weeks.

LESSONS

The combination of tocilizumab and bevacizumab could be an effective therapy for shrinkage of the cystic and solid components of ACP, sparing patients from further neurological damage from the tumor, additional surgery, or radiation. The patient's positive response to tocilizumab and bevacizumab supports the growing literature that interleukin-6 and vascular endothelial growth factor are important for ACP pathogenesis. The patient's response supports prior research, suggesting that systemic chemotherapy can be effectively delivered to this rare brain tumor. https://thejns.org/doi/10.3171/CASE24410.

Pediatric Suprasellar Tumors: Unveiling the Mysteries of Craniopharyngioma and Germ Cell Tumors-Insights From Diagnosis to Advanced Therapeutics

BACKGROUND

Pediatric suprasellar tumors represent a unique and intricate challenge in the landscape of pediatric neuro-oncology.

METHODS

We conducted an in-depth literature review, focusing on large clinical trials and major publications in pediatric suprasellar tumors, particularly craniopharyngiomas and germ cell tumors, to provide a comprehensive perspective on the challenges in the diagnosis, treatment, and molecular aspects of these tumors.

RESULTS

Nestled within the critical confines of the suprasellar region, these tumors manifest against the backdrop of crucial growth and developmental processes. The suprasellar region, housing the pituitary gland and surrounding structures, plays a pivotal role in orchestrating hormonal regulation and growth. The emergence of tumors within this delicate terrain introduces a complex array of challenges, encompassing neurological, endocrinological, and developmental dimensions from damage to the hypothalamic-pituitary axis.

CONCLUSIONS

This article provides a thorough exploration of pediatric craniopharyngiomas and germ cell tumors, elucidating their clinical presentations, treatment modalities, and outcomes. The focused analysis aims to deepen our understanding of these tumors by offering insights for refined clinical management and improved patient outcomes.

IL13RA2-integrated genetically engineered mouse model allows for CAR T cells targeting pediatric high-grade gliomas

Pediatric high-grade gliomas (pHGG) and pediatric diffuse midline gliomas (pDMG) are devastating diseases without durable and curative options. Although targeted immunotherapy has shown promise, the field lacks immunocompetent animal models to study these processes in detail. To achieve this, we developed a fully immunocompetent, genetically engineered mouse model (GEMM) for pDMG and pHGG that incorporates the glioma-associated antigen, interleukin 13 receptor alpha 2 (IL13RA2). Utilizing the RCAS-Tva delivery system in Nestin-Tva mice, we induced gliomagenesis by overexpressing PDGFB and deleting p53 (p53fl/fl) or both p53 and PTEN (p53fl/fl PTENfl/fl), with or without IL13RA2 in neonatal mice. De novo tumors developed in models with and without IL13RA2, showing no statistical difference in onset (n = 33, 38 days, p = 0.62). The p53fl/fl PTENfl/fl tumors displayed more aggressive characteristics (n = 12, 31 days). Tumors exhibited features typical of high-grade glioma, including infiltration, pseudopalisading necrosis, and microvascular proliferation. They also showed a high Ki-67 index, variable IL13RA2 expression, a high frequency of CD11b + macrophages, and a low proportion of CD3 + T cells. The model proved effective for evaluating IL13RA2-targeted immunotherapies, with a significant response to CAR T-cell treatment that extended survival (46 days vs. 28 days control; p < 0.0001) and achieved 25% long-term survival in mice. This model facilitates the preclinical assessment of IL13RA2-directed therapies and holds potential for clinical application.

Sonic hedgehog signalling pathway in CNS tumours: its role and therapeutic implications

CNS tumours encompass a diverse group of neoplasms with significant morbidity and mortality. The SHH signalling pathway plays a critical role in the pathogenesis of several CNS tumours, including gliomas, medulloblastomas and others. By influencing cellular proliferation, differentiation and migration in CNS tumours, the SHH pathway has emerged as a promising target for therapeutic intervention. Current strategies such as vismodegib and sonidegib have shown efficacy in targeting SHH pathway activation. However, challenges such as resistance mechanisms and paradoxical effects observed in clinical settings underscore the complexity of effectively targeting this pathway. Advances in gene editing technologies, particularly CRISPR/Cas9, have provided valuable tools for studying SHH pathway biology, validating therapeutic targets and exploring novel treatment modalities. These innovations have paved the way for a better understanding of pathway dynamics and the development of more precise therapeutic interventions. In addition, the identification and validation of biomarkers of SHH pathway activation are critical to guide clinical decision making and improve patient outcomes. Molecular profiling and biomarker discovery efforts are critical steps towards personalised medicine approaches in the treatment of SHH pathway-associated CNS tumours. While significant progress has been made in understanding the role of the SHH pathway in CNS tumorigenesis, ongoing research is essential to overcome current therapeutic challenges and refine treatment strategies. The integration of molecular insights with advanced technologies and clinical expertise holds great promise for developing more effective and personalised therapies for patients with SHH pathway-driven CNS tumours.

Ferroptosis-related biomarkers for adamantinomatous craniopharyngioma treatment: conclusions from machine learning techniques

Introduction

Adamantinomatous craniopharyngioma (ACP) is difficult to cure completely and prone to recurrence after surgery. Ferroptosis as an iron-dependent programmed cell death, may be a critical process in ACP. The study aimed to screen diagnostic markers related to ferroptosis in ACP to improve diagnostic accuracy.

Methods

Gene expression profiles of ACP were obtained from the gene expression omnibus (GEO) database. Limma package was used to analyze the differently expressed genes (DEGs). The intersection of DEGs and ferroptosis-related factors was obtained as differently expressed ferroptosis-related genes (DEFRGs). Enrichment analysis was processed, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), disease ontology (DO), gene set enrichment analysis (GSEA), and Gene Set Variation Analysis (GSVA) analysis. Machine learning algorithms were undertaken for screening diagnostic markers associated with ferroptosis in ACP. The levels of DEFRGs were verified in ACP patients. A nomogram was drawn to predict the relationship between key DEFRG expression and risk of disease. The disease groups were then clustered by consensus clustering analysis.

Results

DEGs were screened between ACP and normal samples. Ferroptosis-related factors were obtained from the FerrDb V2 and GeneCard databases. The correlation between DEFRGs and ferroptosis markers was also confirmed. A total of 6 overlapped DEFRGs were obtained. Based on the results of the nomogram, CASP8, KRT16, KRT19, and TP63 were the protective factors of the risk of disease, while GOT1 and TFAP2C were the risk factors. According to screened DEFRGs, the consensus clustering matrix was differentiated, and the number of clusters was stable. CASP8, KRT16, KRT19, and TP63, were upregulated in ACP patients, while GOT1 was downregulated. CASP8, KRT16, KRT19, TP63, CASP8, and GOT1 affect multiple ferroptosis marker genes. The combination of these genes might be the biomarker for ACP diagnosis via participating ferroptosis process.

Discussion

Ferroptosis-related genes, including CASP8, KRT16, KRT19, TP63, and GOT1 were the potential markers for ACP, which lays the theoretical foundation for ACP diagnosis.

Identification of clinical prognosis features and significant DNA methylation regulation in pineoblastoma

BACKGROUND

Pineoblastoma (PB) represents a great challenge for clinical management due to lack of a specific therapeutic regimen. This study aims to identify relevant prognostic factors and potential treatment targets by mining public databases.

METHODS

The clinical characteristics and survival data of PB patients were obtained from the SEER database between 2000 and 2019 for Cox regression analysis and nomogram construction. The PB's DNA methylation data was acquired from two GEO datasets, GSE133801 and GSE215240, for bioinformatics analysis.

RESULTS

Of 383 PB patients, Cox univariate analysis unveiled that male gender (p = 0.017), age younger than 3 years at diagnosis (p < 0.001) and absence of radiotherapy (p < 0.001) correlated with poorer overall survival (OS), the subsequent multivariate analysis confirmed sex (p = 0.036), age (p < 0.001) and radiotherapy (p = 0.005) as independent prognostic factors for OS. A nomogram showed robust predictive accuracy as evidenced by AUC values (1-year OS: 0.774, 3-year OS: 0.692, 5-year OS: 0.643). DNA methylation analysis observed tumor hypomethylation, notably in promoter regions. Later, the GO enrichment analysis of aberrantly methylated genes indicated associations with embryonic organ development, cellular membrane composition and DNA-binding transcription, while KEGG analysis revealed enrichment in tumor-associated MAPK, calcium and RAS signaling pathways.

CONCLUSIONS

The prognosis of PB is closely associated with sex, age and receipt of radiotherapy, potentially linked to aberrations in the RAS and MAPK signaling pathways. The individual case suggests that dasatinib and trametinib are potential targeted therapies for improving PB prognosis.

Epigenetic Control of Adamantinomatous Craniopharyngiomas

INTRODUCTION

Studies addressing the methylation pattern in adamantinomatous craniopharyngioma (ACP) are lacking.

OBJECTIVE

To identify methylation signatures in ACPs regarding clinical presentation and outcome.

METHODS

Clinical and pathology data were collected from 35 patients with ACP (54% male; 18.1 years [2-68]). CTNNB1 mutations and methylation profile (MethylationEPIC/Array-Illumina) were analyzed in tumoral DNA. Unsupervised machine learning analysis of this comprehensive methylome sample was achieved using hierarchical clustering and multidimensional scaling. Statistical associations between clusters and clinical features were achieved using the Fisher test and global biological process interpretations were aided by Gene Ontology enrichment analyses.

RESULTS

Two clusters were revealed consistently by all unsupervised methods (ACP-1: n = 18; ACP-2: n = 17) with strong bootstrap statistical support. ACP-2 was enriched by CTNNB1 mutations (100% vs 56%, P = .0006), hypomethylated in CpG island, non-CpG Island sites, and globally (P < .001), and associated with greater tumor size (24.1 vs 9.5 cm3, P = .04). Enrichment analysis highlighted pathways on signaling transduction, transmembrane receptor, development of anatomical structures, cell adhesion, cytoskeleton organization, and cytokine binding, and cell type-specific biological processes as regulation of oligodendrocytes, keratinocyte, and epithelial cells differentiation.

CONCLUSION

Two clusters of patients with ACP were consistently revealed by unsupervised machine learning methods, with one of them significantly hypomethylated, enriched by CTNNB1 mutated ACPs, and associated with increased tumor size. Enrichment analysis reinforced pathways involved in tumor proliferation and in cell-specific tumoral microenvironment.

Pediatric glioma immune profiling identifies TIM3 as a therapeutic target in BRAF fusion pilocytic astrocytoma

Despite being the leading cause of cancer-related childhood mortality, pediatric gliomas have been relatively understudied, and the repurposing of immunotherapies has not been successful. Whole-transcriptome sequencing, single-cell sequencing, and sequential multiplex immunofluorescence were used to identify an immunotherapeutic strategy that could be applied to multiple preclinical glioma models. MAPK-driven pediatric gliomas have a higher IFN signature relative to other molecular subgroups. Single-cell sequencing identified an activated and cytotoxic microglia (MG) population designated MG-Act in BRAF-fused, MAPK-activated pilocytic astrocytoma (PA), but not in high-grade gliomas or normal brain. T cell immunoglobulin and mucin domain 3 (TIM3) was expressed on MG-Act and on the myeloid cells lining the tumor vasculature but not normal brain vasculature. TIM3 expression became upregulated on immune cells in the PA microenvironment, and anti-TIM3 reprogrammed ex vivo immune cells from human PAs to a proinflammatory cytotoxic phenotype. In a genetically engineered murine model of MAPK-driven, low-grade gliomas, anti-TIM3 treatment increased median survival over IgG- and anti-PD-1-treated mice. Single-cell RNA-Seq data during the therapeutic window of anti-TIM3 revealed enrichment of the MG-Act population. The therapeutic activity of anti-TIM3 was abrogated in mice on the CX3CR1 MG-KO background. These data support the use of anti-TIM3 in clinical trials of pediatric low-grade, MAPK-driven gliomas.

Genome-wide CRISPR-Cas9 knockout screens identify DNMT1 as a druggable dependency in sonic hedgehog medulloblastoma

Sonic hedgehog subgroup of medulloblastoma (SHH-MB) is characterized by aberrant activation of the SHH signaling pathway. An inhibition of the positive SHH regulator Smoothened (SMO) has demonstrated promising clinical efficacy. Yet, primary and acquired resistance to SMO inhibitors limit their efficacy. An understanding of underlying molecular mechanisms of resistance to therapy is warranted to bridge this unmet need. Here, we make use of genome-wide CRISPR-Cas9 knockout screens in murine SMB21 and human DAOY cells, in order to unravel genetic dependencies and drug-related genetic interactors that could serve as alternative therapeutic targets for SHH-MB. Our screens reinforce SMB21 cells as a faithful model system for SHH-MB, as opposed to DAOY cells, and identify members of the epigenetic machinery including DNA methyltransferase 1 (DNMT1) as druggable targets in SHH-dependent tumors. We show that Dnmt1 plays a crucial role in normal murine cerebellar development and is required for SHH-MB growth in vivo. Additionally, DNMT1 pharmacological inhibition alone and in combination with SMO inhibition effectively inhibits tumor growth in murine and human SHH-MB cell models and prolongs survival of SHH-MB mouse models by inhibiting SHH signaling output downstream of SMO. In conclusion, our data highlight the potential of inhibiting epigenetic regulators as a novel therapeutic avenue in SMO-inhibitor sensitive as well as resistant SHH-MBs.

The clinical significance of inflammatory mediators in predicting obesity and progression-free survival in patients with adult-onset Craniopharyngioma

BACKGROUND

Craniopharyngioma (CP) is a rare malformational tumor characterized by high rates of recurrence and morbid obesity. However, the role of inflammatory mediators in obesity and the prognosis of patients with CP remains unknown. Therefore, the present study aimed to analyze associations of inflammatory mediators with weight-related outcomes and the prognosis of patients with CP.

METHODS

A total of 130 consecutive patients with CP were included in this study. The expression levels of seven inflammatory mediators and the plasma leptin concentration were investigated. Clinical parameters, weight changes, new-onset obesity, and progression-free survival (PFS) were recorded. The relationships between inflammatory mediators, clinicopathologic parameters, weight-related outcomes, and PFS were explored.

RESULTS

Compared with those in normal pituitary tissue, the expressions of inflammatory mediators in tumor tissue were higher. Higher expression levels of CXCL1 and CXCL8 were identified as independent risk factors for significant weight gain, and CXCL1 and TNF were identified as independent risk factors for new-onset postoperative obesity. Poor PFS was associated with higher expression levels of CXCL1, CXCL8, IL1A, IL6, and TNF.

CONCLUSION

The present study revealed that inflammatory mediators are associated with morbid obesity in patients with CP. Inflammatory mediators may be the critical bridge between elevated leptin and weight-related outcomes. Additionally, PFS was associated with the expression of inflammatory mediators. Further research is needed to elucidate the underlying mechanisms of inflammatory mediators and their potential as targets for novel therapies for CP.

Analysis of KLRB1-Mediated Immunosuppressive Regulation in Adamantinomatous Craniopharyngioma

BACKGROUND

 Adamantinomatous craniopharyngioma (ACP) is the most common type of craniopharyngioma (CP). Under the current surgery and/or radiotherapy strategies, the survival rate is high, but the long-term quality of life is poor because of the relationship between the hypothalamic-pituitary axis and the tumor. Many studies had shown that endocrine deficiencies caused by craniopharyngiomas of the hypothalamic-pituitary axis persist throughout almost the entire life of the patients after surgery, requiring them to receive hormone replacement therapy. Thus, we need to explore new treatments to improve the prognosis of patients. In recent years, there are more and more studies on the immunotherapy of various tumors. However, due to the rarity of the disease, immunotherapy for ACP is rarely researched. The discovery of the tumor immune-suppressive checkpoint KLRB1 (killer cell lectinlike receptor B1), which encodes CD161, may provide a novel target for the treatment of ACP.

METHODS

 Data analysis of retrospective RNA sequencing was conducted in a cohort of 51 pediatric samples in the GSE94349 dataset, and the results were well validated in the GSE68015 dataset including 31 pediatric samples. We used R language as the main tool for statistical analysis and graphical work.

RESULTS

 Our research showed that KLRB1 was enriched in ACP. Additionally, the expression of KLRB1 was positively related to immune functions and most inflammatory responses of ACP. We found that most of the T lineage-related immune responses were positively correlated with KLRB1 expression, and KLRB1 played an important role in the activation of inflammatory processes.

CONCLUSIONS

 KLRB1 is a promising target for immunotherapeutic strategies.

Multiomics integration-based immunological characterizations of adamantinomatous craniopharyngioma in relation to keratinization

Although adamantinomatous craniopharyngioma (ACP) is a tumour with low histological malignancy, there are very few therapeutic options other than surgery. ACP has high histological complexity, and the unique features of the immunological microenvironment within ACP remain elusive. Further elucidation of the tumour microenvironment is particularly important to expand our knowledge of potential therapeutic targets. Here, we performed integrative analysis of 58,081 nuclei through single-nucleus RNA sequencing and spatial transcriptomics on ACP specimens to characterize the features and intercellular network within the microenvironment. The ACP environment is highly immunosuppressive with low levels of T-cell infiltration/cytotoxicity. Moreover, tumour-associated macrophages (TAMs), which originate from distinct sources, highly infiltrate the microenvironment. Using spatial transcriptomic data, we observed one kind of non-microglial derived TAM that highly expressed GPNMB close to the terminally differentiated epithelial cell characterized by RHCG, and this colocalization was verified by asmFISH. We also found the positive correlation of infiltration between these two cell types in datasets with larger cohort. According to intercellular communication analysis, we report a regulatory network that could facilitate the keratinization of RHCG+ epithelial cells, eventually causing tumour progression. Our findings provide a comprehensive analysis of the ACP immune microenvironment and reveal a potential therapeutic strategy base on interfering with these two types of cells.

Exploration of the shared pathways and common biomarker in adamantinomatous craniopharyngioma and type 2 diabetes using integrated bioinformatics analysis

Craniopharyngiomas are rare tumors of the central nervous system that typically present with symptoms such as headache and visual impairment, and those reflecting endocrine abnormalities, which seriously affect the quality of life of patients. Patients with craniopharyngiomas are at higher cardiometabolic risk, defined as conditions favoring the development of type 2 diabetes and cardiovascular disease. However, the underlying common pathogenic mechanisms of craniopharyngiomas and type 2 diabetes are not clear. Especially due to the difficulty of conducting in vitro or in vivo experiments on craniopharyngioma, we thought the common pathway analysis between craniopharyngioma and type 2 diabetes based on bioinformatics is a powerful and feasible method. In the present study, using public datasets (GSE94349, GSE68015, GSE38642 and GSE41762) obtained from the GEO database, the gene expression associated with adamantinomatous craniopharyngioma, a subtype of craniopharyngioma, and type 2 diabetes were analyzed using a bioinformatic approach. We found 11 hub genes using a protein-protein interaction network analysis. Of these, seven (DKK1, MMP12, KRT14, PLAU, WNT5B, IKBKB, and FGF19) were also identified by least absolute shrinkage and selection operator analysis. Finally, single-gene validation and receptor operating characteristic analysis revealed that four of these genes (MMP12, PLAU, KRT14, and DKK1) may be involved in the common pathogenetic mechanism of adamantinomatous craniopharyngioma and type 2 diabetes. In addition, we have characterized the differences in immune cell infiltration that characterize these two diseases, providing a reference for further research.

The Clinical Relevance of the EPH/Ephrin Signaling Pathway in Pediatric Solid and Hematologic Malignancies

Pediatric neoplasms represent a complex group of malignancies that pose unique challenges in terms of diagnosis, treatment, and understanding of the underlying molecular pathogenetic mechanisms. Erythropoietin-producing hepatocellular receptors (EPHs), the largest family of receptor tyrosine kinases and their membrane-tethered ligands, ephrins, orchestrate short-distance cell-cell signaling and are intricately involved in cell-pattern morphogenesis and various developmental processes. Unraveling the role of the EPH/ephrin signaling pathway in the pathophysiology of pediatric neoplasms and its clinical implications can contribute to deciphering the intricate landscape of these malignancies. The bidirectional nature of the EPH/ephrin axis is underscored by emerging evidence revealing its capacity to drive tumorigenesis, fostering cell-cell communication within the tumor microenvironment. In the context of carcinogenesis, the EPH/ephrin signaling pathway prompts a reevaluation of treatment strategies, particularly in pediatric oncology, where the modest progress in survival rates and enduring treatment toxicity necessitate novel approaches. Molecularly targeted agents have emerged as promising alternatives, prompting a shift in focus. Through a nuanced understanding of the pathway's intricacies, we aim to lay the groundwork for personalized diagnostic and therapeutic strategies, ultimately contributing to improved outcomes for young patients grappling with neoplastic challenges.

Adamantinomatous craniopharyngioma: evolution in the management

BACKGROUND

In spite of the continuous progresses in pediatric neurosurgery, adamantinomatous craniopharyngioma (AC) remains a challenging tumor due to its proximity to optic pathways, pituitary gland, hypothalamus, and Willis' circle, which can result in significant endocrine, cognitive, and neurological morbidity after treatment with subsequent impact on the patient's quality of life (QoL). The relevance that QoL has today explains the changes in the management of AC observed over the time. The goal of the present article is to provide a historical background, to show the milestones in the changes of the AC treatment, and to analyze the current main options to manage such a challenging tumor.

MATERIAL AND METHODS

The pertinent literature has been reviewed. Moreover, a comparison between the past and recent personal series is reported.

RESULTS

Three main eras have been identified. The first (named Cushing era) was characterized by the need to realize a harmless surgery and to define the best way to approach AC; the second (microscope era) was characterized by a tremendous technical and technological development, with remarkable results in term of safe tumor resection and control but relatively poor QoL outcomes; and the third one (current period) is characterized by an increasing integration between surgery and adjuvant treatments, with relatively minor tumor control but significant improvement of QoL (comparable overall survival). The authors' experience reflects these changes. Two groups of children were compared: 52 cases (mean follow-up: 17.5 years) belong to the historical series (group 1, 1985-2003, aggressive surgical management) and 41 (mean follow-up: 8.5 years) to the current one (Group 2, 2004-2021, integrated management). No significant differences between the two groups were detected about recurrence rate, surgical mortality, and overall survival. However, Group 2 showed significant lower rates of postoperative panhypopituitarism, obesity, and visual deterioration.

CONCLUSIONS

Radical surgery allows for a good AC control with a low rate of recurrence but high risk of permanent morbidity. Despite the greater number of recurrences and surgeries, the more conservative policy, based on a combination of treatments, seems to provide the same tumor control with a better QoL. The advances in trans-nasal and trans-ventricular endoscopy, in proton therapy and in the management of the AC cyst are the main factors that allowed such an improvement.

Transcription Factor GLI1 Induces IL-6-Mediated Inflammatory Response and Facilitates the Progression of Adamantinomatous Craniopharyngioma

Adamantinomatous craniopharyngioma (ACP) is a neuroendocrine tumor whose pathogenesis remains unclear. This study investigated the role of glioma-associated oncogene family zinc finger 1 (GLI1), a transcription factor in the sonic hedgehog (SHH) signaling pathway, in ACP. We discovered that GLI1 regulates the expression of IL-6, thereby triggering inflammatory responses in ACP and influencing the tumor's progression. Analyzing the Gene Expression Omnibus (GEO) database chip GSE68015, we found that GLI1 is overexpressed in ACP, correlating positively with the spite of ACP and inflammation markers. Knockdown of GLI1 significantly inhibited the levels of tumor necrosis factor α, interleukin-6 (IL-6), and IL-1β in ACP cells, as well as cell proliferation and migration. We further identified a binding site between GLI1 and the promoter region of IL-6, demonstrating that GLI1 can enhance the expression of IL-6. These findings were verified in vivo, where activation of the SHH pathway significantly promoted GLI1 and IL-6 expressions in nude mice, inducing inflammation and tumor growth. Conversely, GLI1 knockdown markedly suppressed these processes. Our study uncovers a potential molecular mechanism for the occurrence of inflammatory responses and tumor progression in ACP.

The hidden hedgehog of the pituitary: hedgehog signaling in development, adulthood and disease of the hypothalamic-pituitary axis

Hedgehog signaling plays pivotal roles in embryonic development, adult homeostasis and tumorigenesis. However, its engagement in the pituitary gland has been long underestimated although Hedgehog signaling and pituitary embryogenic development are closely linked. Thus, deregulation of this signaling pathway during pituitary development results in malformation of the gland. Research of the last years further implicates a regulatory role of Hedgehog signaling in the function of the adult pituitary, because its activity is also interlinked with homeostasis, hormone production, and most likely also formation of neoplasms of the gland. The fact that this pathway can be efficiently targeted by validated therapeutic strategies makes it a promising candidate for treating pituitary diseases. We here summarize the current knowledge about the importance of Hedgehog signaling during pituitary development and review recent data that highlight the impact of Hedgehog signaling in the healthy and the diseased adult pituitary gland.

Contemporary Biological Insights and Clinical Management of Craniopharyngioma

Craniopharyngiomas (CPs) are clinically aggressive tumors because of their invasive behavior and recalcitrant tendency to recur after therapy. There are 2 types based on their distinct histology and molecular features: the papillary craniopharyngioma (PCP), which is associated with BRAF-V600E mutations and the adamantinomatous craniopharyngioma (ACP), characterized by mutations in CTNNB1 (encoding β-catenin). Patients with craniopharyngioma show symptoms linked to the location of the tumor close to the optic pathways, hypothalamus, and pituitary gland, such as increased intracranial pressure, endocrine deficiencies, and visual defects. Treatment is not specific and mostly noncurative, and frequently includes surgery, which may achieve gross total or partial resection, followed by radiotherapy. In cystic tumors, frequent drainage is often required and intracystic instillation of drugs has been used to help manage cyst refilling. More recently targeted therapies have been used, particularly in PCP, but also now in ACP and clinical trials are underway or in development. Although patient survival is high, the consequences of the tumor and its treatment can lead to severe comorbidities resulting in poor quality of life, in particular for those patients who bear tumors with hypothalamic involvement. Accordingly, in these patients at risk for the development of a hypothalamic syndrome, hypothalamus-sparing treatment strategies such as limited resection followed by irradiation are recommended. In this review, we provide an update on various aspects of CP, with emphasis on recent advances in the understanding of tumor pathogenesis, clinical consequences, management, and therapies.

Current Advances in Papillary Craniopharyngioma: State-Of-The-Art Therapies and Overview of the Literature

Craniopharyngiomas are commonly classified as low-grade tumors, although they may harbor a malignant behavior due to their high rate of recurrence and long-term morbidity. Craniopharyngiomas are classically distinguished into two histological types (adamantinomatous and papillary), which have been recently considered by the WHO classification of CNS tumors as two independent entities, due to different epidemiological, radiological, histopathological, and genetic patterns. With regard to papillary craniopharyngioma, a BRAF V600 mutation is detected in 95% of cases. This genetic feature is opening new frontiers in the treatment of these tumors using an adjuvant or, in selected cases, a neo-adjuvant approach. In this article, we present an overview of the more recent literature, focusing on the specificities and the role of oncological treatment in the management of papillary craniopharyngiomas. Based on our research and experience, we strongly suggest a multimodal approach combining clinical, endocrinological, radiological, histological, and oncological findings in both preoperative workup and postoperative follow up to define a roadmap integrating every aspect of this challenging condition.

The molecular pathogenesis of craniopharyngiomas

Research from the last 20 years has provided important insights into the molecular pathogenesis of craniopharyngiomas (CPs). Besides the well-known clinical and histological differences between the subtypes of CPs, adamantinomatous (ACP) and papillary (PCP) craniopharyngiomas, other molecular differences have been identified, further elucidating pathways related to the origin and development of such tumors. The present minireview assesses current knowledge on embryogenesis and the genetic, epigenetic, transcriptomic, and signaling pathways involved in the ACP and PCP subtypes, revealing the similarities and differences in their profiles. ACP and PCP subtypes can be identified by the presence of mutations in CTNNB1 and BRAF genes, with prevalence around 60% and 90%, respectively. Therefore, β-catenin accumulates in the nucleus-cytoplasm of cell clusters in ACPs and, in PCPs, cell immunostaining with specific antibody against the V600E-mutated protein can be seen. Distinct patterns of DNA methylation further differentiate ACPs and PCPs. In addition, research on genetic and epigenetic changes and tumor microenvironment specificities have further clarified the development and progression of the disease. No relevant transcriptional differences in ACPs have emerged between children and adults. In conclusion, ACPs and PCPs present diverse genetic signatures and each subtype is associated with specific signaling pathways. A better understanding of the pathways related to the growth of such tumors is paramount for the development of novel targeted therapeutic agents.

Craniopharyngioma in Pediatrics and Adults

Craniopharyngiomas are rare malignancies of dysembryogenic origin, involving the sellar and parasellar areas. These low-grade, epithelial tumors account for two main histological patterns (adamantinomatous craniopharyngioma and papillary craniopharyngioma), which differ in epidemiology, pathogenesis, and histomorphological appearance. Adamantinomatous craniopharyngiomas typically show a bimodal age distribution (5-15 years and 45-60 years), while papillary craniopharyngiomas are limited to adult patients, especially in the fifth and sixth decades of life. Recently, craniopharyngioma histological subtypes have been demonstrated to harbor distinct biomolecular signatures. Somatic mutations in CTNNB1 gene encoding β-catenin have been exclusively detected in adamantinomatous craniopharyngiomas, which predominantly manifest as cystic lesions, while papillary craniopharyngiomas are driven by BRAF V600E mutations in up to 95% of cases and are typically solid masses. Despite the benign histological nature (grade I according to the World Health Organization classification), craniopharyngiomas may heavily affect long-term survival and quality of life, due to their growth pattern in a critical region for the presence of eloquent neurovascular structures and possible neurological sequelae following their treatment. Clinical manifestations are mostly related to the involvement of hypothalamic-pituitary axis, optic pathways, ventricular system, and major blood vessels of the circle of Willis. Symptoms and signs referable to intracranial hypertension, visual disturbance, and endocrine deficiencies should promptly raise the clinical suspicion for sellar and suprasellar pathologies, advocating further neuroimaging investigations, especially brain MRI. The optimal therapeutic management of craniopharyngiomas is still a matter of debate. Over the last decades, the surgical strategy for craniopharyngiomas, especially in younger patients, has shifted from the aggressive attempt of radical resection to a more conservative and individualized approach via a planned subtotal resection followed by adjuvant radiotherapy, aimed at preserving functional outcomes and minimizing surgery-related morbidity. Whenever gross total removal is not safely feasible, adjuvant radiotherapy (RT) and stereotactic radiosurgery (SRS) have gained an increasingly important role to manage tumor residual or recurrence. The role of intracavitary therapies, including antineoplastic drugs or sealed radioactive sources, is predominantly limited to monocystic craniopharyngiomas as secondary therapeutic option. Novel findings in genetic profiling of craniopharyngiomas have unfold new scenarios in the development of targeted therapies based on brand-new biomolecular markers, advancing the hypothesis of introducing neoadjuvant chemotherapy regimens in order to reduce tumor burden prior to resection. Indeed, the rarity of these neoplasms requires a multispecialty approach involving an expert team of endocrinologists, neurosurgeons, neuro-ophthalmologists, neuroradiologists, radiotherapists, and neuro-oncologists, in order to pursue a significant impact on postoperative outcomes and long-term prognosis.

Targeted therapies in the medical management of craniopharyngioma

Craniopharyngioma (CP) is an intracranial benign tumor that behaves aggressively due to its location, infiltration of the surrounding nervous tissue and high capacity for recurrence. Treatment of choice is surgery followed or not by radiotherapy. Recent advances in molecular biology techniques and the better understanding of the genetic alterations of the two histological types of CP have open new therapeutic perspectives with targeted drugs. Adamantinomatous CP (ACP) is associated with activating mutations of the CTNNB1 gene. Such mutations are accompanied by intracellular accumulation of β-catenin, an oncogenic protein that activates the intracellular Wnt/ β-catenin signaling pathway, which regulates the transcription of genes involved in cell proliferation. Therefore, the use of molecular therapies directed against the activation of the Wnt/ β-catenin pathway could be an attractive and promising therapeutic option in the management of ACPs. On the other hand, papillary CP (PCP) is associated with activating mutations in the BRAF gene. This gene encodes a BRAF protein that plays an important role in the intracellular mitogen-activated protein kinase (MAPK) signaling pathway, which also regulates cell proliferation. The use of BRAF inhibitors either in monotherapy or in combination with mitogen-activated protein kinase (MEK) inhibitors has demonstrated therapeutic efficacy in isolated clinical cases of relapsed PCPs. A preliminary report of a recent phase II clinical trial has shown a therapeutic response in 93.7% of patients with BRAF ^V600E -mutated PCP, with an 85% reduction in tumor size. In the present review we comment on the efficacy and safety of the different drugs being used in patients with PCP.

Adamantinomatous craniopharyngioma cyst fluid can trigger inflammatory activation of microglia to damage the hypothalamic neurons by inducing the production of β-amyloid

INTRODUCTION

The mechanism by which adamantinomatous craniopharyngioma (ACP) damages the hypothalamus is still unclear. Cyst fluid rich in lipids and inflammatory factors is a characteristic pathological manifestation of ACP and may play a very important role in hypothalamic injury caused by tumors.

OBJECTIVE

The objective of this study was to construct a reliable animal model of ACP cyst fluid-induced hypothalamic injury and explore the specific mechanism of hypothalamic injury caused by cyst fluid.

METHODS

An animal model was established by injecting human ACP cyst fluid into the bilateral hypothalamus of mice. ScRNA-seq was performed on the mice hypothalamus and on an ACP sample to obtain a complete gene expression profile for analysis. Data verification was performed through pathological means.

RESULTS

ACP cystic fluid caused growth retardation and an increased obesity index in mice, affected the expression of the Npy, Fgfr2, Rnpc3, Sst, and Pcsk1n genes that regulate growth and energy metabolism in hypothalamic neurons, and enhanced the cellular interaction of Agrp-Mc3r. ACP cystic fluid significantly caused inflammatory activation of hypothalamic microglia. The cellular interaction of CD74-APP is significantly strengthened between inflammatory activated microglia and hypothalamic neurons. Beta-amyloid, a marker of neurodegenerative diseases, was deposited in the ACP tumor tissues and in the hypothalamus of mice injected with ACP cyst fluid.

CONCLUSION

In this study, a novel animal model of ACP cystic fluid-hypothalamic injury was established. For the first time, it was found that ACP cystic fluid can trigger inflammatory activation of microglia to damage the hypothalamus, which may be related to the upregulation of the CD74-APP interaction and deposition of β-amyloid, implying that there may be a similar mechanism between ACP cystic fluid damage to the hypothalamus and neurodegenerative diseases.

The identification of miRNA and mRNA expression profiles associated with pediatric atypical teratoid/rhabdoid tumor

BACKGROUND

Atypical teratoid/rhabdoid tumor (AT/RT) is a malignant pediatric tumor of the central nervous system (CNS) with high recurrence and low survival rates that is often misdiagnosed. MicroRNAs (miRNAs) are involved in the tumorigenesis of numerous pediatric cancers, but their roles in AT/RT remain unclear.

METHODS

In this study, we used miRNA sequencing and gene expression microarrays from patient tissue to study both the miRNAome and transcriptome traits of AT/RT.

RESULTS

Our findings demonstrate that 5 miRNAs were up-regulated, 16 miRNAs were down-regulated, 179 mRNAs were up-regulated and 402 mRNAs were down-regulated in AT/RT. qPCR revealed that hsa-miR-17-5p and MAP7 mRNA were the most significantly differentially expressed miRNA and mRNA in AT/RT tissues. Furthermore, the results from analyses using the miRTarBase database identified MAP7 mRNA as a target gene of hsa-miR-17-5p.

CONCLUSIONS

Our findings suggest that the dysregulation of hsa-miR-17-5p may be a pivotal event in AT/RT and miRNAs that may represent potential therapeutic targets and diagnostic biomarkers.

Integrative Analysis of Biomarkers and Mechanisms in Adamantinomatous Craniopharyngioma

Craniopharyngioma is a benign tumor, and the predominant treatment methods are surgical resection and radiotherapy. However, both treatments may lead to complex complications, seriously affecting patients’ survival rate and quality of life. Adamantinomatous craniopharyngioma (ACP), as one of the histological subtypes of craniopharyngioma, is associated with a high incidence and poor prognosis, and there is a gap in the targeted therapy of immune-related genes for ACP. In this study, two gene expression profiles of ACP, namely GSE68015 and GSE94349, were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) were identified by the Limma package, and 271 differentially expressed immune-related genes (DEIRGs) were obtained from the Immport database. The gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA) were performed for annotation, visualization, and integrated discovery. Five hub genes, including CXCL6, CXCL10, CXCL11, CXCL13, and SAA1, were screened out through protein-protein interaction (PPI) network interaction construction. Two diagnostic markers, namely S100A2 and SDC1 (both of which have the Area Under Curve value of 1), were screened by the machine learning algorithm. CIBERSORT analysis showed that M2 macrophages, activated NK cells, and gamma delta T cells had higher abundance in ACP infiltration, while CD8+ T cells, regulatory T cells, and Neutrophils had less abundance in ACP infiltration. The expression of gamma delta T cells was positively correlated with CXCL6, S100A2, SDC1, and SAA1, while CD8+ T cells expression was negatively correlated with CXCL6, S100A2, SDC1, and CXCL10. ACP with high CXCL6 showed remarkable drug sensitivity to Pentostatin and Wortmannin via CellMiner database analysis. Our results deepened the understanding of the molecular immune mechanism in ACP and provided potential biomarkers for the precisely targeted therapy for ACP.

Identification of Dysregulated Expression of G Protein Coupled Receptors in Endocrine Tumors by Bioinformatics Analysis: Potential Drug Targets?

Background: Many studies link G protein-coupled receptors (GPCRs) to cancer. Some endocrine tumors are unresponsive to standard treatment and/or require long-term and poorly tolerated treatment. This study explored, by bioinformatics analysis, the tumoral profiling of the GPCR transcriptome to identify potential targets in these tumors aiming at drug repurposing. Methods: We explored the GPCR differentially expressed genes (DEGs) from public datasets (Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA)). The GEO datasets were available for two medullary thyroid cancers (MTCs), eighty-seven pheochromocytomas (PHEOs), sixty-one paragangliomas (PGLs), forty-seven pituitary adenomas and one-hundred-fifty adrenocortical cancers (ACCs). The TCGA dataset covered 92 ACCs. We identified GPCRs targeted by approved drugs from pharmacological databases (ChEMBL and DrugBank). Results: The profiling of dysregulated GPCRs was tumor specific. In MTC, we found 14 GPCR DEGs, including an upregulation of the dopamine receptor (DRD2) and adenosine receptor (ADORA2B), which were the target of many drugs. In PGL, seven GPCR genes were downregulated, including vasopressin receptor (AVPR1A) and PTH receptor (PTH1R), which were targeted by approved drugs. In ACC, PTH1R was also downregulated in both the GEO and TCGA datasets and was the target of osteoporosis drugs. Conclusions: We highlight specific GPCR signatures across the major endocrine tumors. These data could help to identify new opportunities for drug repurposing.

Identification and Characterization of TF-lncRNA Regulatory Networks Involved in the Tumorigenesis and Development of Adamantinomatous Craniopharyngioma

Craniopharyngiomas (CPs) are rare tumors arising from the sellar region. Although the best outcome for patients with one subtype, adamantinomatous craniopharyngioma (ACP), is obtained by gross total resection, little is known about the roles of long noncoding RNAs (lncRNAs) and transcription factors (TFs) in ACP tumorigenesis. In total, 12 human ACP and 5 control samples were subjected to transcriptome-level sequencing. We built an integrated algorithm for identifying lncRNAs and TFs regulating the CP-related pathway. Furthermore, ChIP-Seq datasets with binding domain information were used to further verify and identify TF-lncRNA correlations. RT–PCR and immunohistochemistry staining were performed to validate the potential targets. Five pathways associated with ACP were identified and defined by an extensive literature search. Based on the specific pathways and the whole gene expression profile, 266 ACP-related lncRNAs and 39 TFs were identified by our integrating algorithm. Comprehensive analysis of the ChIP-Seq datasets revealed that 29 TFs were targeted by 12000 lncRNAs in a wide range of tissues, including 161 ACP-related lncRNAs that were identified by the computational method. These 29 TFs and 161 lncRNAs, constituting 1004 TF-lncRNA pairs, were shown to potentially regulate different ACP-related pathways. A total of 232 TF-lncRNA networks were consequently established based on differential gene expression. Validation by RT–PCR and immunohistochemistry staining revealed positive expression of the ACP-related TFs E2F2 and KLF5 in ACP. Moreover, the expression of the lncRNA RP11-360P21.2 was shown to be upregulated in ACP tissues. In this study, we introduced an integrated algorithm for identifying lncRNAs and TFs regulating the ACP-related pathway. This is the first comprehensive study to systematically investigate the potential TF and lncRNA regulatory network in ACP. The resulting data serve as a valuable resource for understanding the mechanisms underlying ACP-related lncRNAs and TFs.

Medical Therapy for Craniopharyngiomas

Craniopharyngiomas are rare benign neoplasms presenting in two different types, adamantinomatous (ACP) or papillary (PCP), which are molecularly and clinically distinct. Traditional treatment includes surgical resection and radiotherapy, which are accompanied by a number of debilitating complications because of the tumours' proximity to important brain structures. Recent advances in the understanding of molecular pathogenesis of craniopharyngiomas have opened horizons to medical therapeutic options. ACPs are mainly characterized by mutations of β-catenin, which activate Wingless/Int (Wnt), and alter the mitogen extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, as well as inflammatory, cellular senescence, programmed cell death and sonic hedgehog (SHH) pathways. PCPs are mainly characterized by Ras/Raf/MEK/ERK pathway activation secondary to BRAF-V600E mutations. MEK inhibitors, such as binimetinib, or anti-inflammatory mediators, such as tocilizumab or interferon, have been administered to patients with ACP and the efficacy is mostly favourable. On the other hand, BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCP resulting in favourable responses. A number of ongoing trials will shed light on schemes, doses, combined treatments and safety issues of the new molecular-targeted treatments, changing the management of patients with craniopharyngiomas by launching the era of personalized medicine in these rare neoplasms. We conducted a systematic review to identify case series or case reports with patients currently treated with systemic medical therapy.

Treatment of Cystic Craniopharyngiomas: An Update

In spite of the significant technical and technological progress in neurosurgery and the continuous discoveries by the basic research, adamantinomatous craniopharyngioma remains a significant clinical challenge. Actually, the huge size of the tumor, its multiple cystic components, the encasement of Willis' circle and optic pathways, and the invasion of the hypothalamus often prevent its safe surgical resection. Moreover, the local aggressiveness of the tumor accounts for a high risk of recurrence even after a gross total resection. For these reasons, more and more efforts are being dedicated to enhance the knowledge about AC and improve the tools for its treatment.This paper is dedicated to the most recent advances concerning the AC management. Promising, new insights come for the basic research, thanks to the updates on the role of the WNT-β-catenin pathway (important for the tumor genesis and progression, not yet developed enough for a safe target therapy in children but useful for determining the prognosis) and the inflammatory mediators (widely overexpressed, especially by the cyst of the tumor, and for which target therapies are being developed). Moreover, further factors and pathways are under investigation.Also the development of new treatment strategies accounts for the improvement of the prognosis and the quality of life of AC patients. The enhancement of the experience with the endoscopic techniques (both transsphenoidal and transventricular approaches) actually allows to perform a less invasive but effective surgery that can be coupled with new modalities of radiation therapy aiming at obtaining a reliable control of the disease and protecting the endocrinological, ophthalmological, and neurological functions. A special mention is finally deserved by the techniques specifically designed for the intracystic therapy (as cyst fenestration alone or in combination with administration of radionuclides or bleomycin or interferon-α) that are here analyzed together with the aforementioned advances.

A Novel Immune Classification for Predicting Immunotherapy Responsiveness in Patients With Adamantinomatous Craniopharyngioma

Adamantinomatous craniopharyngioma (ACP) is the most common tumor of the sellar region in children. The aggressive behavior of ACP challenges the treatment for it. However, immunotherapy is rarely studied in ACP. In this research, we performed unsupervised cluster analysis on the 725 immune-related genes and arrays of 39 patients with ACP patients in GSE60815 and GSE94349 databases. Two novel immune subtypes were identified, namely immune resistance (IR) subtype and immunogenic (IG) subtype. Interestingly, we found that the ACPs with IG subtype (34.78%, 8/23) were more likely to respond to immunotherapy than the ACPs with IR subtype (6.25%, 1/16) via tumor immune dysfunction and exclusion (TIDE) method. Simultaneously, the enrichment analysis indicated that the differentially expressed genes (DEGs) (p < 0.01, FDR < 0.01) of the IG subtype were chiefly involved in inflammatory and immune responses. However, the DEGs of the IR subtype were mainly involved in RNA processing. Next, immune infiltration analysis revealed a higher proportion of M2 macrophage in the IG subtype than that in the IR subtype. Compared with the IR subtype, the expression levels of immune checkpoint molecules (PD1, PDL1, PDL2, TIM3, CTLA4, Galectin9, LAG3, and CD86) were significantly upregulated in the IG subtype. The ssGSEA results demonstrated that the biofunction of carcinogenesis in the IG subtype was significantly enriched, such as lymphocyte infiltration, mesenchymal phenotype, stemness maintenance, and tumorigenic cytokines, compared with the IR subtype. Finally, a WDR89 (the DEG between IG and IR subtype)-based nomogram model was constructed to predict the immune classification of ACPs with excellent performance. This predictive model provided a reliable classification assessment tool for clinicians and aids treatment decision-making in the clinic.

Endocrine Disorder in Patients With Craniopharyngioma

Craniopharyngioma is an intracranial congenital epithelial tumor growing along the pathway of the embryonic craniopharyngeal tube. The main clinical symptoms of patients with craniopharyngioma include high intracranial pressure, visual field defect, endocrine dysfunction, and hypothalamic dysfunction. At present, the preferred treatment remains the surgical treatment, but the recovery of endocrine and hypothalamic function following surgery is limited. In addition, endocrine disorders often emerge following surgery, which seriously reduces the quality of life of patients after operation. So far, research on craniopharyngioma focuses on ways to ameliorate endocrine dysfunction. This article reviews the latest research progress on pathogenesis, manifestation, significance, and treatment of endocrine disorders in patients with craniopharyngioma.

In-depth proteomic profiling captures subtype-specific features of craniopharyngiomas

Craniopharyngiomas are rare epithelial tumors derived from pituitary gland embryonic tissue. This epithelial tumor can be categorized as an adamantinomatous craniopharyngioma (ACP) or papillary craniopharyngioma (PCP) subtype with histopathological and genetic differences. Genomic and transcriptomic profiles of craniopharyngiomas have been investigated; however, the proteomic profile has yet to be elucidated and added to these profiles. Recent improvements in high-throughput quantitative proteomic approaches have introduced new opportunities for a better understanding of these diseases and the efficient discovery of biomarkers. We aimed to confirm subtype-associated proteomic changes between ACP and PCP specimens. We performed a system-level proteomic study using an integrated approach that combines mass spectrometry-based quantitative proteomic, statistical, and bioinformatics analyses. The bioinformatics analysis showed that differentially expressed proteins between ACP and PCP were significantly involved in mitochondrial organization, fatty acid metabolic processes, exocytosis, the inflammatory response, the cell cycle, RNA splicing, cell migration, and neuron development. Furthermore, using network analysis, we identified hub proteins that were positively correlated with ACP and PCP phenotypes. Our findings improve our understanding of the pathogenesis of craniopharyngiomas and provide novel insights that may ultimately translate to the development of craniopharyngioma subtype-specific therapeutics.

Childhood-onset Craniopharyngioma

Craniopharyngiomas are rare embryonic malformational tumors of the sellar/parasellar region, classified by the World Health Organization (WHO) as tumors with low-grade malignancy (WHO I). The childhood adamantinomatous subtype of craniopharyngioma is usually cystic with calcified areas. At the time of diagnosis, hypothalamic/pituitary deficits, visual disturbances, and increased intracranial pressure are major symptoms. The treatment of choice in case of favorable tumor location (without hypothalamic involvement) is complete resection. It is important to ensure that optical and hypothalamic functionality are preserved. In case of unfavorable tumor location, that is with hypothalamic involvement, a hypothalamus-sparing surgical strategy with subsequent local irradiation of residual tumor is recommended. In the further course of the disease, recurrences and progression often occur. Nevertheless, overall survival rates are high at 92%. Severe impairment of quality of life and comorbidities such as metabolic syndrome, hypothalamic obesity, and neurological consequences can be observed in patients with disease- and/or treatment-related lesions of hypothalamic structures. Childhood-onset craniopharyngioma frequently manifests as a chronic disease so that patients require lifelong, continuous care by experienced multidisciplinary teams to manage clinical and quality of life consequences. For this review, a search for original articles and reviews published between 1986 and 2020 was performed in Pubmed, Science Citation Index Expanded, EMBASE, and Scopus. The search terms used were "craniopharyngioma, hypothalamus, pituitary obesity, irradiation, neurosurgery.

MMP12 is a potential therapeutic target for Adamantinomatous craniopharyngioma: Conclusions from bioinformatics analysis and in vitro experiments

Adamantinomatous craniopharyngioma (ACP) is considered a benign intracranial tumor, but it can also exhibit aggressive characteristics. Due to its unique location in the suprasellar, which brings it close to important nerves and vascular structures, ACP can often lead to significant neuroendocrine diseases. The current treatments primarily include surgical intervention, radiation therapy or a combination of the two, but these can lead to serious complications and adversely affect the quality of life of patients. Thus, it is important to identify effective and safe alternatives. Recently, studies have focused on the tumor genome, transcriptome and proteome in an attempt to identify potential therapeutic targets for clinical use. However, studies on this region of the CP are limited; thus, the present study focused on this region. The GSE94349 and GSE68015 datasets were downloaded from the Gene Expression Omnibus database and analyzed. In the in vitro studies, the effect of the matrix metalloproteinase (MMP)12 inhibitor, MMP408, on cell proliferation and protein expression was assessed. The results demonstrated that MMP408 effectively inhibited cell proliferation and migration of ACP cells, and decreased the expression levels of the related proteins. Thus, MMP12 may be used as a potential therapeutic target for the treatment of ACP.

Adamantinomatous craniopharyngioma associated with a compromised blood-brain barrier: patient series

BACKGROUND

Adamantinomatous craniopharyngioma (ACP) is a highly morbid adult and pediatric brain tumor derived from epithelial remnants of the craniopharyngeal canal (Rathke's pouch), which gives rise to the anterior pituitary gland. Standard therapy includes maximal safe resection with or without radiation therapy. Systemic antitumor therapy remains elusive. Immune-related paracrine signaling involving the interleukin-6 receptor (IL-6R) may contribute to ACP pathogenesis. Tocilizumab, a recombinant humanized monoclonal antibody against IL-6R, is approved by the US Food and Drug Administration but does not cross an intact blood-brain barrier.

OBSERVATIONS

In a phase 0 trial design, a single dose of tocilizumab was delivered intravenously before clinically indicated surgical intervention in 3 children with ACP. The presence of tocilizumab was assayed in plasma, tumor tissue, tumor cyst fluid, and cerebrospinal fluid (n = 1) using a novel enzyme-linked immunosorbent assay. Tocilizumab reached ACP tumor tissue and/or cyst fluid after one systemic dose in every patient.

LESSONS

This finding helps explain extant data that indicate tocilizumab may contribute to ACP therapy. It further indicates that ACP does not reside behind an intact blood-brain barrier, dramatically broadening the range of potential antitumor therapies against this tumor. This has substantial implications for the design of future clinical trials for novel therapies against ACP in both children and adults.

Adamantinomatous craniopharyngioma: moving toward targeted therapies

The evolving characterization of the biological basis of adamantinomatous craniopharyngioma (ACP) has provided insights critical for novel systemically delivered therapies. While current treatment strategies for ACP are associated with low mortality rates, patients experience severely lowered quality of life due to high recurrence rates and chronic sequelae, presenting a need for novel effective treatment regimens. The identification of various dysregulated pathways that play roles in the pathogenesis of ACP has prompted the investigation of novel treatment options. Aberrations in the CTNNB1 gene lead to the dysregulation of the Wnt pathway and the accumulation of nuclear β-catenin, which may play a role in tumor invasiveness. While Wnt pathway/β-catenin inhibition may be a promising treatment for ACP, potential off-target effects have limited its use in current intervention strategies. Promising evidence of the therapeutic potential of cystic proinflammatory mediators and immunosuppressants has been translated into clinical therapies, including interleukin 6 and IDO-1 inhibition. The dysregulation of the pathways of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), epidermal growth factor receptor (EGFR), and programmed cell death protein 1 and its ligand (PD-1/PD-L1) has led to identification of various therapeutic targets that have shown promise as clinical strategies. The Sonic Hedgehog (SHH) pathway is upregulated in ACP and has been implicated in tumorigenesis and tumor growth; however, inhibition of SHH in murine models decreased survival, limiting its therapeutic application. While further preclinical and clinical data are needed, systemically delivered therapies could delay or replace the need for more aggressive definitive treatments. Ongoing preclinical investigations and clinical trials of these prospective pathways promise to advance treatment approaches aimed to increase patients' quality of life.

A Regulatory Loop of FBXW7-MYC-PLK1 Controls Tumorigenesis of MYC-Driven Medulloblastoma

Simple Summary

Group 3 medulloblastoma (MB) is often accompanied by MYC amplification and has a poor prognosis. FBXW7, a critical tumor suppressor in many types of cancer, regulates the proteasome-mediated degradation of oncoproteins including MYC. However, the role of FBXW7 in the tumorigenesis of group 3 MB has not been well studied. In this study, we show that FBXW7 is downregulated in group 3 MB patient samples, and FBXW7 stabilization is crucial for inhibiting c-MYC. We identified a FBXW7-MYC-PLK1 regulatory loop in MYC-driven MB, which provides a mechanism of using protein kinase inhibitors for translation in the future.

Abstract

Polo-like kinase 1 (PLK1) is highly expressed in group 3 medulloblastoma (MB), and it has been preclinically validated as a cancer therapeutic target in medulloblastoma. Here, we demonstrate that PLK1 inhibition with PCM-075 or BI6727 significantly reduces the growth of MB cells and causes a decrease of c-MYC mRNA and protein levels. We show that MYC activates PLK1 transcription, while the inhibition of PLK1 suppresses MB tumor development and causes a decrease in c-MYC protein level by suppressing FBXW7 auto poly-ubiquitination. FBXW7 physically interacts with PLK1 and c-MYC, facilitating their protein degradation by promoting ubiquitination. These results demonstrate a PLK1-FBXW7-MYC regulatory loop in MYC-driven medulloblastoma. Moreover, FBXW7 is significantly downregulated in group 3 patient samples. The overexpression of FBXW7 induced apoptosis and suppressed proliferation in vitro and in vivo, while constitutive phosphorylation mutation attenuated its tumor suppressor function. Altogether, these findings demonstrated that PLK1 inhibition stabilizes FBXW7 in MYC-driven MB, thus revealing an important function of FBXW7 in suppressing medulloblastoma progression.

Advances in Targeted Therapies for Pediatric Brain Tumors

Purpose of Review

Over the last years, our understanding of the molecular biology of pediatric brain tumors has vastly improved. This has led to more narrowly defined subgroups of these tumors and has created new potential targets for molecularly driven therapies. This review presents an overview of the latest advances and challenges of implementing targeted therapies into the clinical management of pediatric brain tumors, with a focus on gliomas, craniopharyngiomas, and medulloblastomas.

Recent Findings

Pediatric low-grade gliomas (pLGG) show generally a low mutational burden with the mitogen-activated protein kinase (MAPK) signaling presenting a key driver for these tumors. Direct inhibition of this pathway through BRAF and/or MEK inhibitors has proven to be a clinically relevant strategy. More recently, MEK and IL-6 receptor inhibitors have started to be evaluated in the treatment for craniopharyngiomas. Aside these low-grade tumors, pediatric high-grade gliomas (pHGG) and medulloblastomas exhibit substantially greater molecular heterogeneity with various and sometimes unknown tumor driver alterations. The clinical benefit of different targeted therapy approaches to interfere with altered signaling pathways and restore epigenetic dysregulation is undergoing active clinical testing. For these multiple pathway-driven tumors, combination strategies will most likely be required to achieve clinical benefit.

Summary

The field of pediatric neuro-oncology made tremendous progress with regard to improved diagnosis setting the stage for precision medicine approaches over the last decades. The potential of targeted therapies has been clearly demonstrated for a subset of pediatric brain tumors. However, despite clear response rates, questions of sufficient blood-brain barrier penetration, optimal dosing, treatment duration as well as mechanisms of resistance and how these can be overcome with potential combination strategies need to be addressed in future investigations. Along this line, it is critical for future trials to define appropriate endpoints to assess therapy responses as well as short and long-term toxicities in the growing and developing child.

Adamantinomatous craniopharyngioma in the molecular age and the potential of targeted therapies: a review

Pediatric adamantinomatous craniopharyngiomas (ACPs) are histologically benign brain tumors that often follow an aggressive clinical course. Arising in the sellar/suprasellar region, they grow in close proximity to critical neurological and vascular structures and can result in significant neuroendocrine morbidity. First-line treatment often involves surgical resection with or without radiotherapy and has been associated with significant morbidity and poor quality of life outcomes. As a result, the discovery of alternative effective and safe treatments is clearly desirable. In recent years, laboratory studies have harnessed sophisticated techniques to identify the upregulation of several markers that may represent potential therapeutic targets. These targets include IL-6, PD1/PD-L1, MEK, IDO-1, and others. Agents that target these pathways exist, and there is an opportunity to investigate their potential efficacy in the treatment of ACP. Trials investigating some of these agents as monotherapy and in combination for the treatment of pediatric ACP are underway or in development. If positive, these trials may result in a paradigm shift in treatment that will hopefully result in reduced morbidity and better outcomes for patients.

Identification of Core Genes and Pathways in Medulloblastoma by Integrated Bioinformatics Analysis

Medulloblastoma (MB) is one of the most common intracranial malignancies in children. The present study applied integrated bioinformatics to identify potential core genes associated with the pathogenesis of MB and reveal potential molecular mechanisms. Through the integrated analysis of multiple data sets from the Gene Expression Omnibus (GEO), 414 differentially expressed genes (DEGs) were identified. Combining the protein-protein interaction (PPI) network analysis with gene set enrichment analysis (GSEA), eight core genes, including CCNA2, CCNB1, CCNB2, AURKA, CDK1, MAD2L1, BUB1B, and RRM2, as well as four core pathways, including "cell cycle", "oocyte meiosis", "p53 pathway" and "DNA replication" were selected. In independent data sets, the core genes showed superior diagnostic values and significant prognostic correlations. Moreover, in the pan-caner data of the cancer genome atlas (TCGA), the core genes were also widely abnormally expressed. In conclusion, this study identified core genes and pathways of MB through integrated analysis to deepen the understanding of the molecular mechanisms underlying the MB and provide potential targets and pathways for diagnosis and treatment of MB.

New pyrimidines and triazolopyrimidines as antiproliferative and antioxidants with cyclooxygenase-1/2 inhibitory potential

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Transcriptional analyses of adult and pediatric adamantinomatous craniopharyngioma reveals similar expression signatures regarding potential therapeutic targets

Adamantinomatous craniopharyngioma (ACP) is a biologically benign but clinically aggressive lesion that has a significant impact on quality of life. The incidence of the disease has a bimodal distribution, with peaks occurring in children and older adults. Our group previously published the results of a transcriptome analysis of pediatric ACPs that identified several genes that were consistently overexpressed relative to other pediatric brain tumors and normal tissue. We now present the results of a transcriptome analysis comparing pediatric to adult ACP to identify biological differences between these groups that may provide novel therapeutic insights or support the assertion that potential therapies identified through the study of pediatric ACP may also have a role in adult ACP. Using our compiled transcriptome dataset of 27 pediatric and 9 adult ACPs, obtained through the Advancing Treatment for Pediatric Craniopharyngioma Consortium, we interrogated potential age-related transcriptional differences using several rigorous mathematical analyses. These included: canonical differential expression analysis; divisive, agglomerative, and probabilistic based hierarchical clustering; information theory based characterizations; and the deep learning approach, HD Spot. Our work indicates that there is no therapeutically relevant difference in ACP gene expression based on age. As such, potential therapeutic targets identified in pediatric ACP are also likely to have relvance for adult patients.

Biological Behaviour of Craniopharyngiomas

Jakob Erdheim (1874-1937) first described craniopharyn-giomas (CPs) as "hypophyseal duct tumours" and postulated the existence of two tumour types based on their histological features: (1) an aggressive type showing similarities to adamantinomas (tumours of the jaw) and (2) a more benign form characterised by the presence of papillary structures. More than a century later, these initial observations have been confirmed; based on their distinct genetic, epigenetic, and histological features, the WHO classifies CPs into two types: adamantinomatous CPs (ACPs) and papillary CPs (PCPs). Considerable knowledge has been generated on the biology of CPs in the last 20 years. Mutations in CTNNB1 (encoding β-catenin) are prevalent in ACP, whilst PCPs frequently harbour mutations in BRAF (p.BRAF-V600E). The consequence of these mutations is the activation of either the WNT/β-catenin (ACP) or the MAPK/ERK (PCP) pathway. Murine models support a critical role for these mutations in tumour formation and have provided important insights into tumour pathogenesis, mostly in ACP. A critical role for cellular senescence has been uncovered in murine models of ACP with relevance to human tumours. Several gene profiling studies of human and murine ACP tumours have identified potential targetable pathways, and novel therapeutic agents are being used in clinical and pre-clinical research, in some cases with excellent results. In this review, we will present the accumulated knowledge on the biological features of these tumours and summarise how these advances are being translated into potential novel treatments.

The Inflammatory Milieu of Adamantinomatous Craniopharyngioma and Its Implications for Treatment

Pediatric Adamantinomatous Craniopharyngiomas (ACPs) are histologically benign brain tumors that often follow an aggressive clinical course. Their suprasellar location leaves them in close proximity to critical neurological and vascular structures and often results in significant neuroendocrine morbidity. Current treatment paradigms, involving surgical resection and radiotherapy, confer significant morbidity to patients and there is an obvious need to discover effective and safe alternative treatments. Recent years have witnessed significant efforts to fully detail the genomic, transcriptomic and proteomic make-up of these tumors, in an attempt to identify potential therapeutic targets. These studies have resulted in ever mounting evidence that inflammatory processes and the immune response play a critical role in the pathogenesis of both the solid and cystic portion of ACPs. Several inflammatory and immune markers have been identified in both the cyst fluid and solid tumor tissue of ACP. Due to the existence of effective agents that target them, IL-6 and immune checkpoint inhibitors seem to present the most likely immediate candidates for clinical trials of targeted immune-related therapy in ACP. If effective, such agents may result in a paradigm shift in treatment that ultimately reduces morbidity and results in better outcomes for our patients.

Feasibility of primary human cell cultures as a model for adamantinomatous craniopharyngioma research: Evidence from RNA-Seq analysis

Adamantinomatous craniopharyngioma (ACP) is a benign epithelial tumor of the sellar region. Whether primary human cell cultures can be used as a stable research model has yet to be determined. The characteristics of three cultured craniopharyngioma primary cell (CPC) lines were identified using immunofluorescence. The culture duration for each CPC line was 10, 20 and 30 days. Cell lines and paired parental tumor tissues were subsequently analyzed using transcriptome sequencing (RNA-Seq). Transcriptomic differences between ACP tissues and CPC lines were compared. CPCs maintained the original epithelial lineage markers, including pan-cytokeratin and epithelial cell adhesion molecule. However, the Pearson's correlation coefficient of transcriptomes between each pair of CPC lines and ACP tissues decreased from 0.657 (cultured for 10 days) to 0.61 (cultured for 20 days) and further to 0.547 (cultured for 30 days). The number of differentially expressed genes between ACP tissues and CPCs was increased from 1,247 (cultured for 10 days) to 1,643 (cultured for 20 days) and then to 1,949 (cultured for 30 days). The results of Gene Set Enrichment Analysis demonstrated that the diversity of gene sets increased with longer culture time. Significant differences in the majority of signature gene sets were not observed between ACP tissues and CPCs, with the exception of keratinization phenotype [normalized enrichment score (NES)=−2.02, false discovery rate (FDR)=0.0038] and epithelial cell phenotype (NES=−1.82, FDR=0.032). Cell proliferation (NES=1.78, FDR=0.028) and mitosis (NES=1.93, FDR=0.012) were enhanced in CPCs. Therefore, primary human cell cultures can be used as a suitable research platform for ACP, however further experiments are required.

The Medical Therapy of Craniopharyngiomas: The Way Ahead

CONTEXT

Craniopharyngiomas, which are categorized as adamantinomatous (ACPs) or papillary (PCPs), have traditionally been treated with surgery and/or radiotherapy, although when the tumors progress or recur, therapeutic possibilities are very limited. Following recent advances in their molecular pathogenesis, new medical therapeutic options have emerged.

EVIDENCE ACQUISITION

The search strategy that we selected to identify the appropriate evidence involved the following medical subject headings (MeSH) terms: ("Craniopharyngioma" [MeSH] AND "Craniopharyngioma/drug therapy" [MeSH]) NOT ("review" [Publication Type] OR "review literature as topic" [MeSH Terms] OR "review" [All Fields]) AND ("2009/05/01" [PDat]: "2019/04/28" [PDat]).

EVIDENCE SYNTHESIS

Mutations of β-catenin causing Wnt activation with alterations of the MEK/ERK pathway are encountered in the great majority of patients with ACPs; specific alterations also stratify patients to a more aggressive behavior. In most PCPs there is primary activation of the Ras/Raf/MEK/ERK pathway secondary to BRAF-V600E mutations. BRAF inhibitors, such as dabrafenib or vemurafenib, either alone or in combination with the MEK inhibitors trametinib and cobimetinib, have been administered to patients with PCPs producing clinically useful and, in some cases, sustained responses. In contrast to PCPs, drugs targeting β-catenin and its downstream MAPK pathway in ACPs have so far only been used in in vitro studies, but there appear to be promising new targets clinically.

CONCLUSIONS

The identification of specific genetic alterations in patients with craniopharyngiomas has expanded the therapeutic options, providing evidence for a customized approach using newer molecular agents. More studies including a larger number of carefully selected patients are required to evaluate the response to currently available and evolving agents alone and in combination.

Craniopharyngioma

Craniopharyngiomas are rare malformational tumours of low histological malignancy arising along the craniopharyngeal duct. The two histological subtypes, adamantinomatous craniopharyngioma (ACP) and papillary craniopharyngioma (PCP), differ in genesis and age distribution. ACPs are diagnosed with a bimodal peak of incidence (5-15 years and 45-60 years), whereas PCPs are restricted to adults mainly in the fifth and sixth decades of life. ACPs are driven by somatic mutations in CTNNB1 (encoding β-catenin) that affect β-catenin stability and are predominantly cystic in appearance. PCPs frequently harbour somatic BRAFV600E mutations and are typically solid tumours. Clinical manifestations due to increased intracranial pressure, visual impairment and endocrine deficiencies should prompt imaging investigations, preferentially MRI. Treatment comprises neurosurgery and radiotherapy; intracystic chemotherapy is used in monocystic ACP. Although long-term survival is high, quality of life and neuropsychological function are frequently impaired due to the close anatomical proximity to the optic chiasm, hypothalamus and pituitary gland. Indeed, hypothalamic involvement and treatment-related hypothalamic lesions frequently result in hypothalamic obesity, physical fatigue and psychosocial deficits. Given the rarity of these tumours, efforts to optimize infrastructure and international collaboration should be research priorities.

Craniopharyngioma: a roadmap for scientific translation

OBJECTIVE Craniopharyngiomas are among the most challenging of intracranial tumors to manage because of their pattern of growth, associated morbidities, and high recurrence rate. Complete resection on initial encounter can be curative, but it may be impeded by the risks posed by the involved neurovascular structures. Recurrent craniopharyngiomas, in turn, are frequently refractory to additional surgery and adjuvant radiation or chemotherapy. METHODS The authors conducted a review of primary literature. RESULTS Recent advances in the understanding of craniopharyngioma biology have illuminated potential oncogenic targets for pharmacotherapy. Specifically, distinct molecular profiles define two histological subtypes of craniopharyngioma: adamantinomatous and papillary. The discovery of overactive B-Raf signaling in the adult papillary subtype has led to reports of targeted inhibitors, with a growing acceptance for refractory cases. An expanding knowledge of the biological underpinnings of craniopharyngioma will continue to drive development of targeted therapies and immunotherapies that are personalized to the molecular signature of each individual tumor. CONCLUSIONS The rapid translation of genomic findings to medical therapies for recurrent craniopharyngiomas serves as a roadmap for other challenging neurooncological diseases.

Targeting IL-6 Is a Potential Treatment for Primary Cystic Craniopharyngioma

Adamantinomatous craniopharyngioma (ACP) makes up between 6 and 8% of pediatric brain tumors and is the most common pediatric tumor arising in the sellar/suprasellar region of the brain. The 10-year survival for patients diagnosed with craniopharyngioma ranges between 64 and 92%, but complicating factors such as location, common cyst formation, and potential hypothalamic infiltration cause significant morbidity in this population. There are a number of therapeutic options for children with ACP, including surgery, radiation, and cyst directed therapies such as interferon and bleomycin. Research has raised concerns regarding the efficacy and side effects associated with these conventional therapies, as well as with the difficulty in treating recurrent cystic ACP. Evidence from our group and others has shown that the cystic and solid tumor components of craniopharyngioma have high levels of IL-6R and IL-6, providing a potential target for therapy. Tocilizumab, a humanized monoclonal antibody, acts against soluble and membrane bound IL-6R, and has been widely utilized in pediatric patients. Two patients with recurrent cystic ACP were offered systemically administered tocilizumab or a combination of tocilizumab and bevacizumab on a compassionate use basis. Both patients' tumors had a significant response, with decreased cyst burden, supporting the assertion that tocilizumab with or without bevacizumab may be an option for patients suffering from cystic ACP.