Pediatric Adamantinomatous Craniopharyngioma Research Articles

CP-03. EXTRACELLULAR MATRIX REMODELING REVEALS NON-CELL AUTONOMOUS TUMOR FORMATION MECHANISM IN ADAMANTINOMATOUS CRANIOPHARYNGIOMAS

Abstract Adamantinomatous Craniopharyngioma (ACP) is a rare pituitary tumor of the sellar region, with a bimodal presentation pattern in children and middle-aged adults. ACPs are primarily driven by a mutation in CTNNB1 that prevents beta-catenin from degrading properly, resulting in accumulation in the nuclei of epithelial whorl-like structures sometimes referred to as cluster cells. Clinical management is challenging due to the location of the tumor, such that complete surgical resection is often not possible so radiation therapy, which can lead to high morbidity, is also used. Greater insight into these tumors can help develop less damaging treatment strategies. In this analysis we have employed single-cell RNA sequencing technology to examine seven pediatric human ACPs (28594 cells). Using consensus non-negative matrix factorization, and traditional marker genes, we have partitioned our dataset into several cell types including cluster cells, palisading epithelial cells, microglia, T-cells, B-cells, plasma cells, and fibroblasts. Though cluster cells themselves do not actively proliferate, we believe the complex inter-cellular signaling is responsible for tumor formation. We propose a model in which malignant fibroblasts form from the existing epithelium and remodel the extracellular matrix (ECM) creating a stiffened tumor microenvironment. To support this claim we show activation markers suggesting myofibroblast differentiation, the expression of EMT signatures indicating a transformation from epithelial to fibroblast, and RNA velocity analysis that demonstrates lineage tracing. We believe that the remodeling of the ECM is a wound healing response influenced by TGF-beta, SPP1, and other signaling pathways. Our analysis of ACPs reveals the role of the tumor microenvironment in the formation of these tumors.

RARE-29. Transcriptome characterization of pediatric adamantinomatous craniopharyngioma at the cellular level

Abstract BACKGROUND: Adamantinomatous Craniopharyngioma (ACP) is a neurologically devastating brain tumor that affects children and adults. It is histologically heterogeneous with epithelial populations that are characterized by the nuclear accumulation of mutated β-catenin, and activated Wnt signaling. Current models suggest that ACP growth is driven through paracine mechanisms characterized by the senescence-associated secretory phenotype (SASP). However, detailed pathogenic mechanisms remain unknown. Improved definition of the various cellular phenotypes that compose ACP will inform and advance our understanding of this disease. METHODS: Single cell RNA-sequencing (scRNA-seq) and multiplex ELISA were performed on pediatric ACP tissue and cyst fluid, respectively. Reference scRNA-seq data was obtained from PanglaoDB. Preprocessing and standard analyses were conducted using Seurat software. Cellular phenotypes were annotated using the Human Primary Cell atlas. Differential expression and functional enrichment analyses were utilized to identify Wnt-signaling activation and epithelial subpopulations. Paracrine signaling was inferred via CellChatDB. SASP Atlas was utilized to query marker gene lists. Pseudotemporal ordering was performed using monocle3. RESULTS: ACP tissue is heterogenous and contains multiple distinct immune signatures. ACP tissue contains 2 unique epithelial subpopulations, which demonstrate canonical Wnt-signaling and SASP, respectively. Pseudotemporal ordering suggests the initial oncogenic event to be of epidermal character, with subsequent aggressive behavior from a separate epithelial cell population. CONCLUSIONS: Based on gene expression, cell populations that correspond to the histologically identifiable epithelial whorls and palisading epithelium can be identified. These subpopulations display unique functional signatures. Simultaneous and synergistic therapeutic targeting of these separate epithelial populations may lead to improved patient care.

MODL-24. AN ORGANOTYPIC CHUNK CULTURE TECHNIQUE TO STUDY DISEASE MECHANISM AND DEVELOP TARGETED THERAPEUTICS FOR PEDIATRIC ADAMANTINOMATOUS CRANIOPHARYNGIOMA

BACKGROUNDAdvances in the treatment of Adamantinomatous Craniopharyngioma (ACP) face challenges with translation to clinical study due to the absence of robust culture models of the disease. We developed a technique for culturing human ACP tissue in an organotypic chunk culture format that retains the tumor microenvironment for a duration sufficient to evaluate potential targeted therapeutics.METHODSIntraoperatively collected tumor tissue from pediatric ACP was cut into volumes of approximately 3 mm3 and rested over a semi-permeable insert placed in the wells of a 6-well plate. Specimens were cultured in (1) Control media, media containing (2) Tocilizumab, (3) Trametinib, and (4) combination of Tocilizumab and Trametinib, for 24 and 96 hours. Specimens were harvested for paraffin embedding, protein and gene expression assays. Supernatants were collected to assay secreted components. Paraffin embedded specimens were sectioned and stained for H&E, Pan-CK, Beta-Catenin, cleaved Caspase-3, Ki-67, and Phospho-ERK.RESULTSH&E staining revealed characteristic histologic features of ACP with epithelial cells with palisading nuclei, wet keratin and ghost cells. Tumor sections were markedly positive for epithelial cell markers, Pan-CK and Beta-Catenin. Ki-67 and cleaved Caspase-3 were restricted to a small fraction of cells, indicating low index of proliferation and apoptosis under the culture conditions. The response to drug treatments shall be determined using gene expression assays and evaluation of the secreted components.CONCLUSIONThe organotypic chunk culture technique appears to maintain the viability and integrity of ACP tumors for several days and may serve as an appropriate model for pre-clinical studies to develop targeted therapeutics for pediatric ACP.

Prediction of CTNNB1 Mutation Status in Pediatric Cystic Adamantinomatous Craniopharyngioma by Using Preoperative Magnetic Resonance Imaging Manifestation

ObjectiveCTNNB1-targeted inhibitor is demonstrated to be an effective neoadjuvant therapy in adamantinomatous craniopharyngioma (ACP) patients and cystic degeneration is a canonical sign of pediatric ACP. This study aimed to investigate the relationship between the cystic performances and CTNNB1 mutation (CTNNB1 MUT) status so as to analyze the possible diagnostic criteria of CTNNB1 MUT in pediatric cystic ACP (PCACP). MethodsPatient’s population, clinical characteristics, tissue samples and MRI data were collected and summarized in PCACP patients. The results were compared between CTNNB1 MUT and CTNNB1 wild-type (WT) groups according to the Sanger sequencing. MRI features of the cyst were also recorded. The receiving operating characteristic (ROC) curve analysis was applied to evaluate the differential diagnostic value. Results19 of the 61 patients manifested CTNNB1 MUT PCACP and 42 patients were CTNNB1 WT PCACP. Multiple cysts, irregular shape of cyst, hypo-intense interior signal of cyst on non-contrast T1W1, compression with optic chiasm and pituitary stalk and enhancement signal of cystic wall have been demonstrated in CTNNB1 MUT PCACP patients on MRI. Only the Area under the curve (AUC) values of quantity of cyst, shape of cyst and interior signal of cyst on non-contrast T1W1 were over 0.7. For criteria based on the combination of the 6 characteristic features, the AUC value was 0.928. ConclusionPreoperative MRI may provide an effective value in predicting PCACP patients with CTNNB1 MUT and offer potential evidence for preoperative management with molecular targeted agents.

Adamantinomatous craniopharyngioma: advances in proteomic research.

Many efforts have been performed in the last decade to accomplish the genomic and proteomic characterization of pediatric adamantinomatous craniopharyngioma with the purpose to elucidate the molecular mechanisms underlying the onset and development of this pediatric brain tumor, its high recurrence rate, and, although classified as a histologically benign neoplasm, its aggressive behavior. The focus of this review is to perform the new comparison of the proteomic profiles of the solid component and the intracystic fluid of adamantinomatous craniopharyngioma based on our previous results, obtained by both the top-down and the bottom-up proteomic approaches, to disclose differences and similarities, and to discuss the results in the context of the most recent literature. Proteins and peptides identified in the cyst fluid and in the solid component of adamantinomatous craniopharyngioma (AC) include beyond markers of inflammation (i.e., alpha-defensins), proteins involved in cell migration and protein degradation (i.e., beta-thymosin and ubiquitin peptides), whose main role might be in tumor growth and infiltration of the surrounding neural structures. These last appeared different in the solid components compared with the cyst fluid, missing their terminal part in the solid tissue, a feature generally associated to malignancies, which might represent a distinct molecular site for an aggressive behavior of AC.

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.

Interrater reliability of a method to assess hypothalamic involvement in pediatric adamantinomatous craniopharyngioma.

Pediatric adamantinomatous craniopharyngiomas (ACPs) are histologically benign brain tumors that confer significant neuroendocrine morbidity. Previous studies have demonstrated that injury to the hypothalamus is associated with worsened quality of life and a shorter lifespan. This insight helps many surgeons define the goals of surgery for patients with ACP. Puget and colleagues proposed a 3-tiered preoperative and postoperative grading system based on the degree of hypothalamic involvement identified on MRI. In a prospective cohort from their institution, the authors found that use of the system to guide operative goals was associated with decreased morbidity. To date, however, the Puget system has not been externally validated. Here, the authors present an interrater reliability study that assesses the generalizability of this system for surgeons planning initial operative intervention for children with craniopharyngiomas. A panel of 6 experts, consisting of pediatric neurosurgeons and pediatric neuroradiologists, graded 30 preoperative and postoperative MRI scans according to the Puget system. Interrater reliability was calculated using Fleiss' κ and Krippendorff's α statistics. Interrater reliability in the preoperative context demonstrated moderate agreement (κ = 0.50, α = 0.51). Interrater reliability in the postoperative context was 0.27 for both methods of statistical evaluation. Interrater reliability for the system as defined is moderate. Slight refinements of the Puget MRI grading system, such as collapsing the 3 grades into 2, may improve its reliability, making the system more generalizable.

Molecular Analyses Reveal Inflammatory Mediators in the Solid Component and Cyst Fluid of Human Adamantinomatous Craniopharyngioma.

Pediatric adamantinomatous craniopharyngioma (ACP) is a highly solid and cystic tumor, often causing substantial damage to critical neuroendocrine structures such as the hypothalamus, pituitary gland, and optic apparatus. Paracrine signaling mechanisms driving tumor behavior have been hypothesized, with IL-6R overexpression identified as a potential therapeutic target. To identify potential novel therapies, we characterized inflammatory and immunomodulatory factors in ACP cyst fluid and solid tumor components. Cytometric bead analysis revealed a highly pro-inflammatory cytokine pattern in fluid from ACP compared to fluids from another cystic pediatric brain tumor, pilocytic astrocytoma. Cytokines and chemokines with particularly elevated concentrations in ACPs were IL-6, CXCL1 (GRO), CXCL8 (IL-8) and the immunosuppressive cytokine IL-10. These data were concordant with solid tumor compartment transcriptomic data from a larger cohort of ACPs, other pediatric brain tumors and normal brain. The majority of receptors for these cytokines and chemokines were also over-expressed in ACPs. In addition to IL-10, the established immunosuppressive factor IDO-1 was overexpressed by ACPs at the mRNA and protein levels. These data indicate that ACP cyst fluids and solid tumor components are characterized by an inflammatory cytokine and chemokine expression pattern. Further study regarding selective cytokine blockade may inform novel therapeutic interventions.

CR-11PEDIATRIC ADAMANTINOMATOUS CRANIOPHARYNGIOMA CYST FLUID DEMONSTRATES A PRO-INFLAMMATORY MILIEU

CR-11. PEDIATRIC ADAMANTINOMATOUS CRANIOPHARYNGIOMA CYST FLUID DEMONSTRATES A PRO-INFLAMMATORY MILIEU Andrew Donson2, Andrea Griesinger2, Vladimir Amani2, Richard C.E. Anderson4, Toba N. Niazi3, Michael H. Handler1,2, Nicholas K. Foreman1,2, and Todd C. Hankinson1,2; Children’s Hospital Colorado, Aurora, CO, USA; University of Colorado School of Medicine, Aurora, CO, USA; Nicklaus Children’s Hospital, Miami, FL, USA; Morgan Stanley Children’s Hospital of New York-Presbyterian, New York, NY, USA BACKGROUND: The cyst component of pediatric adamantinomatous craniopharyngioma (ACP) often exerts substantial mass effect, grows unpredictably, and is poorly responsive to radiation therapy. Current cyst-directed therapies mandate surgical intervention. An improved understanding of the drivers of ACP cyst growth may allow for the identification of systemic therapies that can control cyst expansion and improve tumor control and/or our ability to safely undertake radical tumor resection. METHODS: Milliplex cytokine expression analysis was used to compare the cytokine milieu of ACP cyst (n 1⁄4 5) to another common cyst generating pediatric brain tumor, Juvenile Pilocytic Astrocytoma (JPA, n 1⁄4 5). The ratio of cytokine levels in the 2 tumor types was compared. RESULTS: Compared to JPA cysts, all ACP specimens showed a highly pro-inflammatory cytokine pattern. Among the cytokines with elevated expression level ratios in ACP, relative to JPA, were IL-6 (353.9, p 1⁄4 1.23x10); IL-8 (57.6, p 1⁄4 0.04); IL-10 (35.5, p 1⁄4 0.003); TNF-a (8.21, p 1⁄4 0.01); and IL-1b (3.65, p 1⁄4 0.005). CONCLUSIONS: ACP cyst fluid appears to be characterized by a highly pro-inflammatory cytokine expression pattern. Understanding the cellular source of these cytokines and the efficacy of selective cytokine blockade may represent an opportunity for therapeutic intervention. Neuro-Oncology 18:iii18–iii23, 2016. doi:10.1093/neuonc/now068.11 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Identification of targets for rational pharmacological therapy in childhood craniopharyngioma.

IntroductionPediatric adamantinomatous craniopharyngioma (ACP) is a histologically benign but clinically aggressive brain tumor that arises from the sellar/suprasellar region. Despite a high survival rate with current surgical and radiation therapy (75–95 % at 10 years), ACP is associated with debilitating visual, endocrine, neurocognitive and psychological morbidity, resulting in excheptionally poor quality of life for survivors. Identification of an effective pharmacological therapy could drastically decrease morbidity and improve long term outcomes for children with ACP.ResultsUsing mRNA microarray gene expression analysis of 15 ACP patient samples, we have found several pharmaceutical targets that are significantly and consistently overexpressed in our panel of ACP relative to other pediatric brain tumors, pituitary tumors, normal pituitary and normal brain tissue. Among the most highly expressed are several targets of the kinase inhibitor dasatinib – LCK, EPHA2 and SRC; EGFR pathway targets – AREG, EGFR and ERBB3; and other potentially actionable cancer targets – SHH, MMP9 and MMP12. We confirm by western blot that a subset of these targets is highly expressed in ACP primary tumor samples.ConclusionsWe report here the first published transcriptome for ACP and the identification of targets for rational therapy. Experimental drugs targeting each of these gene products are currently being tested clinically and pre-clinically for the treatment of other tumor types. This study provides a rationale for further pre-clinical and clinical studies of novel pharmacological treatments for ACP. Development of mouse and cell culture models for ACP will further enable the translation of these targets from the lab to the clinic, potentially ushering in a new era in the treatment of ACP.

Craniopharyngioma: A pathologic, clinical, and surgical review

Craniopharyngioma is a rare and mostly benign epithelial tumor of the sellar and suprasellar region. Two principal patterns of craniopharyngioma are recognized: papillary and adamantinomatous. Papillary craniopharyngiomas are encountered in adults and may lack the cystic spaces filled with "motor oil" as well as the palisading peripheral rows of epithelial cells, keratinization, or calcification typical of pediatric adamantinomatous craniopharyngioma. Secondary to their anatomic location, craniopharyngiomas may present with endocrinologic dysfunction and visual disturbances. Differential diagnosis includes Rathke's cleft cyst, pituitary adenoma, dermoid/epidermoid cysts, and other rare sellar/suprasellar lesions as pituicytomas. Many controversies exist concerning the preferred surgical approach for these tumors. Endoscopic endonasal surgery is no longer reserved only for sellar or small cystic suprasellar lesions. Prechiasmatic/preinfundibular lesions are effectively removed using an endonasal transtuberculum/transplanum approach; subchiasmatic/transinfundibular tumors require the addition of a transellar approach with inferior pituitary transposition; and retrochiasmatic/retroinfundibular lesions are better accessed performing an endonasal superior pituitary transposition. Compared with well-established trancranial approaches (pterional, subfrontal, presigmoid), endoscopic endonasal surgery combines the virtues of the caudocranial and midline approaches, allowing for appropriate infrachiasmatic exposure without the need for manipulation of surrounding neurovascular structures to access the tumor. This anatomic advantage, combined with high-definition wide-angle visualization, exquisite endonasal microsurgical techniques, and devoted instrumentation facilitates a high rate of endocrine function preservation and visual improvement, while concurrently achieving comparable resections. Endoscopic skull base reconstruction with the vascularized nasoseptal flap has dramatically reduced the incidence of cerebrospinal fluid leak, consolidating endoscopic endonasal surgery as an effective and safe alternative for the treatment of these challenging tumors.