RESUMEN

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.

Asunto(s)

Craneofaringioma , Metilación de ADN , Epigénesis Genética , Neoplasias Hipofisarias , beta Catenina , Humanos , Craneofaringioma/genética , Craneofaringioma/patología , Masculino , Femenino , Neoplasias Hipofisarias/genética , Neoplasias Hipofisarias/patología , Adolescente , Adulto , Niño , Persona de Mediana Edad , Adulto Joven , beta Catenina/genética , beta Catenina/metabolismo , Preescolar , Anciano , Mutación , Islas de CpG/genética , Regulación Neoplásica de la Expresión Génica

RESUMEN

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, ß-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.

Asunto(s)

Craneofaringioma , Neoplasias Hipofisarias , Adulto , Niño , Humanos , Craneofaringioma/genética , Craneofaringioma/metabolismo , Craneofaringioma/patología , Neoplasias Hipofisarias/genética , Mutación/genética , Microambiente Tumoral

RESUMEN

Objectives: To evaluate how telomere length behaves in adamantinomtous craniopharyngioma (aCP) and if it contributes to the pathogenesis of aCPs with and without CTNNB1 mutations. Design: Retrospective cross-sectional study enrolling 42 aCP patients from 2 tertiary institutions. Methods: Clinicopathological features were retrieved from the patient's charts. Fresh frozen tumors were used for RNA and DNA analyses. Telomere length was evaluated by qPCR (T/S ratio). Somatic mutations in TERT promoter (TERTp) and CTNNB1 were detected by Sanger and/or whole-exome sequencing. We performed RNA-Seq to identify differentially expressed genes in aCPs presenting with shorter or longer telomere lengths. Results: Mutations in CTNNB1 were detected in 29 (69%) tumors. There was higher frequency of CTNNB1 mutations in aCPs from patients diagnosed under the age of 15 years (85% vs 15%; P = 0.04) and a trend to recurrent disease (76% vs 24%; P = 0.1). No mutation was detected in the TERTp region. The telomeres were shorter in CTNNB1-mutated aCPs (0.441, IQR: 0.297-0.597vs 0.607, IQR: 0.445-0.778; P = 0.04), but it was neither associated with clinicopathological features nor with recurrence. RNAseq identified a total of 387 differentially expressed genes, generating two clusters, being one enriched for short telomeres and CTNNB1-mutated aCPs. Conclusions: CTNNB1: mutations are more frequent in children and adolescents and appear to associate with progressive disease. CTNNB1-mutated aCPs have shorter telomeres, demonstrating a relationship between the Wnt/ß-catenin pathway and telomere biology in the pathogenesis of aCPs.

Asunto(s)

Craneofaringioma , Telómero , beta Catenina , Adolescente , Niño , Craneofaringioma/genética , Estudios Transversales , Humanos , Mutación , Estudios Retrospectivos , Telómero/ultraestructura , Vía de Señalización Wnt , beta Catenina/genética

RESUMEN

INTRODUCTION: Activating mutations in exon 3 of the ß-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between ß-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the ß-catenin gene was screened for mutations, and the expression of the ß-catenin gene and PROP1 was evaluated. ß-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and ß-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and ß-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the ß-catenin gene were identified in 64% of the adamantinomatous craniopharyngiomas samples. Evidence of ß-catenin gene overexpression was found in 71% of the tumors with ß-catenin mutations and in 40% of the tumors without mutations, and ß-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of ß-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear ß-catenin staining pattern regardless of the presence of a ß-catenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort.

Asunto(s)

Craneofaringioma/genética , Proteínas de Homeodominio/genética , Neoplasias Hipofisarias/genética , beta Catenina/genética , Adolescente , Niño , Preescolar , Craneofaringioma/patología , Análisis Mutacional de ADN , Femenino , Expresión Génica , Humanos , Lactante , Masculino , Neoplasias Hipofisarias/patología , Transducción de Señal/genética , Activación Transcripcional/genética , Proteínas Wnt/genética , Adulto Joven

RESUMEN

INTRODUCTION: Activating mutations in exon 3 of the β-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between β-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the β-catenin gene was screened for mutations, and the expression of the β-catenin gene and PROP1 was evaluated. β-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and β-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and β-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the β-catenin gene were identified in 64 percent of the adamantinomatous craniopharyngiomas samples. Evidence of β-catenin gene overexpression was found in 71 percent of the tumors with β-catenin mutations and in 40 percent of the tumors without mutations, and β-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of β-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear β-catenin staining pattern regardless of the presence of a bcatenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort.

Asunto(s)

Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Adulto Joven , Craneofaringioma/genética , Proteínas de Homeodominio/genética , Neoplasias Hipofisarias/genética , beta Catenina/genética , Craneofaringioma/patología , Análisis Mutacional de ADN , Expresión Génica , Neoplasias Hipofisarias/patología , Transducción de Señal/genética , Activación Transcripcional/genética , Proteínas Wnt/genética

RESUMEN

Genes involved in formation/development of the adenohypophysis, CTNNB1 gene, and microRNAs might be implicated in the craniopharyngioma pathogenesis. The objective of this study is to perform the molecular analysis of HESX1, PROP1, POU1F1, and CTNNB1 genes and evaluate a panel of miRNA expression in craniopharyngioma. We also verified whether the presence of CTNNB1 mutation is associated with clinical findings and miRNA expression. The study included 16 patients with adamantinomatous craniopharyngioma (nine children and seven adults; eight females and eight males; 6-55 years, median 15.5 years). DNA, RNA, and cDNA were obtained from craniopharyngioma and normal pituitaries. DNA was also extracted from peripheral blood of healthy subjects. All genes were amplified by polymerase chain reaction and direct sequenced. Relative quantification of miRNA expression was calculated using the 2(-ΔΔCt) method. We found no mutations in HESX1, PROP1, and POU1F1 genes and four polymorphisms in PROP1 gene which were in Hardy-Weinberg equilibrium and had similar allelic frequencies in craniopharyngioma and controls. We found seven different mutations in CTNNB1 in eight of 16 patients. Younger patients presented more frequently CTNNB1 mutation than adults. We observed hyperexpression of miR-150 (1.7-fold); no different expression of miR-16-1, miR-21, and miR23a; and an underexpression of miR-141, let-7a, miR-16, miR-449, miR-145, miR-143, miR-23b, miR-15a, and miR-24-2 (ranging from -7.5 to -2.5-fold; p = 0.02) in craniopharyngioma. There was no association between tumor size or the recurrence and the presence of CTNNB1mutations. miR-16 and miR-141 were underexpressed in craniopharyngioma presenting CTNNB1 mutations. miR-23a and miR24-2 were hyperexpressed in patients who underwent only one surgery. Mutations or polymorphisms in pituitary transcription factors are unlikely to contribute to the adamantinomatous craniopharyngioma pathogenesis, differently of CTNNB1 mutations. Our data suggest the potential involvement of the deregulation of miRNA expression in the craniopharyngioma pathogenesis and outcome and also that the miRNA could modulate the Wnt signaling pathway in craniopharyngioma tumorigenesis.

Asunto(s)

Craneofaringioma/genética , MicroARNs/genética , Neoplasias Hipofisarias/genética , Factores de Transcripción/genética , beta Catenina/genética , Adolescente , Adulto , Anciano , Niño , Craneofaringioma/patología , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Proteínas de Homeodominio/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación , Hipófisis/metabolismo , Hipófisis/patología , Neoplasias Hipofisarias/patología , Polimorfismo de Nucleótido Simple , Factor de Transcripción Pit-1/genética , Adulto Joven

RESUMEN

OBJECT: The purpose of this study was to examine chromosomal gains and losses in 11 pediatric adamantinomatous craniopharyngiomas by using comparative genomic hybridization (CGH), as well as to review the cytogenetic literature that has contributed to the characterization of these tumors. One source of confusion in the cytogenetic and CGH literature concerning craniopharyngioma is that the authors of most studies fail to distinguish between pediatric and later-onset forms of the disease. Thus, this study was focused on pediatric craniopharyngioma. METHODS: To determine an overview of the genetic events leading to the development of these tumors, 10 adamantinomatous craniopharyngiomas were analyzed using CGH; none of the tumor specimens demonstrated gains or losses of DNA sequence. CONCLUSIONS: In view of these findings as well as those published in the majority of previous cytogenetic studies of craniopharyngiomas, the authors conclude that the recurrent acquisition of chromosomal imbalances does not play a major role in tumorigenesis and that chromosomal gains and losses are a relatively rare event in primary tumors of pediatric origin.

Asunto(s)

Aberraciones Cromosómicas , Craneofaringioma/genética , ADN de Neoplasias/análisis , Neoplasias Hipofisarias/genética , Adolescente , Edad de Inicio , Transformación Celular Neoplásica/genética , Niño , Preescolar , Inestabilidad Cromosómica , Citogenética , Femenino , Humanos , Masculino , Hibridación de Ácido Nucleico , Recurrencia

RESUMEN

Craniopharyngioma is the most common childhood tumor and thought to arise from embryonic remnants of Rathke's pouch. The paucity of published data on the molecular basis of these tumors prompted us to examine 22 adamantinomatous craniopharyngiomas looking for genetic abnormalities. Using the X-linked polymorphic androgen receptor gene as a tool for X-chromosome inactivating analysis, we found that a subset of craniopharyngiomas are monoclonal and therefore are probably due to acquired somatic genetic defects. Thus, we investigated these tumours for mutations within three candidate genes, Gsalpha, Gi2alpha and patched (PTCH). Using single stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis and direct sequencing, the presence of somatic mutations in these genes could not be demonstrated in any tumor. Our data indicate that a subset of craniopharyngiomas are monoclonal and the mutations in the PTCH, Gsalpha, and Gi2alpha contribute little if any to craniopharyngioma development.

Asunto(s)

Adenoma/genética , Neoplasias Encefálicas/genética , Craneofaringioma/genética , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/genética , Subunidades alfa de la Proteína de Unión al GTP Gs/genética , Proteínas Proto-Oncogénicas/genética , Adenoma/patología , Anticuerpos Monoclonales , Neoplasias Encefálicas/patología , Craneofaringioma/patología , Cartilla de ADN , Exones/genética , Subunidad alfa de la Proteína de Unión al GTP Gi2 , Humanos , Mutación/genética , Polimorfismo Conformacional Retorcido-Simple , Desnaturalización Proteica , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa